drivers/block/rbd.c

   1
   2 /*
   3    rbd.c -- Export ceph rados objects as a Linux block device
   4
   5
   6    based on drivers/block/osdblk.c:
   7
   8    Copyright 2009 Red Hat, Inc.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; see the file COPYING.  If not, write to
  21    the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  22
  23
  24
  25    For usage instructions, please refer to:
  26
  27                  Documentation/ABI/testing/sysfs-bus-rbd
  28
  29  */
  30
  31 #include <linux/ceph/libceph.h>
  32 #include <linux/ceph/osd_client.h>
  33 #include <linux/ceph/mon_client.h>
  34 #include <linux/ceph/cls_lock_client.h>
  35 #include <linux/ceph/decode.h>
  36 #include <linux/parser.h>
  37 #include <linux/bsearch.h>
  38
  39 #include <linux/kernel.h>
  40 #include <linux/device.h>
  41 #include <linux/module.h>
  42 #include <linux/blk-mq.h>
  43 #include <linux/fs.h>
  44 #include <linux/blkdev.h>
  45 #include <linux/slab.h>
  46 #include <linux/idr.h>
  47 #include <linux/workqueue.h>
  48
  49 #include "rbd_types.h"
  50
  51 #define RBD_DEBUG       /* Activate rbd_assert() calls */
  52
  53 /*
  54  * The basic unit of block I/O is a sector.  It is interpreted in a
  55  * number of contexts in Linux (blk, bio, genhd), but the default is
  56  * universally 512 bytes.  These symbols are just slightly more
  57  * meaningful than the bare numbers they represent.
  58  */
  59 #define SECTOR_SHIFT    9
  60 #define SECTOR_SIZE     (1ULL << SECTOR_SHIFT)
  61
  62 /*
  63  * Increment the given counter and return its updated value.
  64  * If the counter is already 0 it will not be incremented.
  65  * If the counter is already at its maximum value returns
  66  * -EINVAL without updating it.
  67  */
  68 static int atomic_inc_return_safe(atomic_t *v)
  69 {
  70         unsigned int counter;
  71
  72         counter = (unsigned int)__atomic_add_unless(v, 1, 0);
  73         if (counter <= (unsigned int)INT_MAX)
  74                 return (int)counter;
  75
  76         atomic_dec(v);
  77
  78         return -EINVAL;
  79 }
  80
  81 /* Decrement the counter.  Return the resulting value, or -EINVAL */
  82 static int atomic_dec_return_safe(atomic_t *v)
  83 {
  84         int counter;
  85
  86         counter = atomic_dec_return(v);
  87         if (counter >= 0)
  88                 return counter;
  89
  90         atomic_inc(v);
  91
  92         return -EINVAL;
  93 }
  94
  95 #define RBD_DRV_NAME "rbd"
  96
  97 #define RBD_MINORS_PER_MAJOR            256
  98 #define RBD_SINGLE_MAJOR_PART_SHIFT     4
  99
 100 #define RBD_MAX_PARENT_CHAIN_LEN        16
 101
 102 #define RBD_SNAP_DEV_NAME_PREFIX        "snap_"
 103 #define RBD_MAX_SNAP_NAME_LEN   \
 104                         (NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))
 105
 106 #define RBD_MAX_SNAP_COUNT      510     /* allows max snapc to fit in 4KB */
 107
 108 #define RBD_SNAP_HEAD_NAME      "-"
 109
 110 #define BAD_SNAP_INDEX  U32_MAX         /* invalid index into snap array */
 111
 112 /* This allows a single page to hold an image name sent by OSD */
 113 #define RBD_IMAGE_NAME_LEN_MAX  (PAGE_SIZE - sizeof (__le32) - 1)
 114 #define RBD_IMAGE_ID_LEN_MAX    64
 115
 116 #define RBD_OBJ_PREFIX_LEN_MAX  64
 117
 118 #define RBD_NOTIFY_TIMEOUT      5       /* seconds */
 119 #define RBD_RETRY_DELAY         msecs_to_jiffies(1000)
 120
 121 /* Feature bits */
 122
 123 #define RBD_FEATURE_LAYERING    (1<<0)
 124 #define RBD_FEATURE_STRIPINGV2  (1<<1)
 125 #define RBD_FEATURE_EXCLUSIVE_LOCK (1<<2)
 126 #define RBD_FEATURES_ALL        (RBD_FEATURE_LAYERING |         \
 127                                  RBD_FEATURE_STRIPINGV2 |       \
 128                                  RBD_FEATURE_EXCLUSIVE_LOCK)
 129
 130 /* Features supported by this (client software) implementation. */
 131
 132 #define RBD_FEATURES_SUPPORTED  (RBD_FEATURES_ALL)
 133
 134 /*
 135  * An RBD device name will be "rbd#", where the "rbd" comes from
 136  * RBD_DRV_NAME above, and # is a unique integer identifier.
 137  */
 138 #define DEV_NAME_LEN            32
 139
 140 /*
 141  * block device image metadata (in-memory version)
 142  */
 143 struct rbd_image_header {
 144         /* These six fields never change for a given rbd image */
 145         char *object_prefix;
 146         __u8 obj_order;
 147         __u8 crypt_type;
 148         __u8 comp_type;
 149         u64 stripe_unit;
 150         u64 stripe_count;
 151         u64 features;           /* Might be changeable someday? */
 152
 153         /* The remaining fields need to be updated occasionally */
 154         u64 image_size;
 155         struct ceph_snap_context *snapc;
 156         char *snap_names;       /* format 1 only */
 157         u64 *snap_sizes;        /* format 1 only */
 158 };
 159
 160 /*
 161  * An rbd image specification.
 162  *
 163  * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
 164  * identify an image.  Each rbd_dev structure includes a pointer to
 165  * an rbd_spec structure that encapsulates this identity.
 166  *
 167  * Each of the id's in an rbd_spec has an associated name.  For a
 168  * user-mapped image, the names are supplied and the id's associated
 169  * with them are looked up.  For a layered image, a parent image is
 170  * defined by the tuple, and the names are looked up.
 171  *
 172  * An rbd_dev structure contains a parent_spec pointer which is
 173  * non-null if the image it represents is a child in a layered
 174  * image.  This pointer will refer to the rbd_spec structure used
 175  * by the parent rbd_dev for its own identity (i.e., the structure
 176  * is shared between the parent and child).
 177  *
 178  * Since these structures are populated once, during the discovery
 179  * phase of image construction, they are effectively immutable so
 180  * we make no effort to synchronize access to them.
 181  *
 182  * Note that code herein does not assume the image name is known (it
 183  * could be a null pointer).
 184  */
 185 struct rbd_spec {
 186         u64             pool_id;
 187         const char      *pool_name;
 188
 189         const char      *image_id;
 190         const char      *image_name;
 191
 192         u64             snap_id;
 193         const char      *snap_name;
 194
 195         struct kref     kref;
 196 };
 197
 198 /*
 199  * an instance of the client.  multiple devices may share an rbd client.
 200  */
 201 struct rbd_client {
 202         struct ceph_client      *client;
 203         struct kref             kref;
 204         struct list_head        node;
 205 };
 206
 207 struct rbd_img_request;
 208 typedef void (*rbd_img_callback_t)(struct rbd_img_request *);
 209
 210 #define BAD_WHICH       U32_MAX         /* Good which or bad which, which? */
 211
 212 struct rbd_obj_request;
 213 typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);
 214
 215 enum obj_request_type {
 216         OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
 217 };
 218
 219 enum obj_operation_type {
 220         OBJ_OP_WRITE,
 221         OBJ_OP_READ,
 222         OBJ_OP_DISCARD,
 223 };
 224
 225 enum obj_req_flags {
 226         OBJ_REQ_DONE,           /* completion flag: not done = 0, done = 1 */
 227         OBJ_REQ_IMG_DATA,       /* object usage: standalone = 0, image = 1 */
 228         OBJ_REQ_KNOWN,          /* EXISTS flag valid: no = 0, yes = 1 */
 229         OBJ_REQ_EXISTS,         /* target exists: no = 0, yes = 1 */
 230 };
 231
 232 struct rbd_obj_request {
 233         const char              *object_name;
 234         u64                     offset;         /* object start byte */
 235         u64                     length;         /* bytes from offset */
 236         unsigned long           flags;
 237
 238         /*
 239          * An object request associated with an image will have its
 240          * img_data flag set; a standalone object request will not.
 241          *
 242          * A standalone object request will have which == BAD_WHICH
 243          * and a null obj_request pointer.
 244          *
 245          * An object request initiated in support of a layered image
 246          * object (to check for its existence before a write) will
 247          * have which == BAD_WHICH and a non-null obj_request pointer.
 248          *
 249          * Finally, an object request for rbd image data will have
 250          * which != BAD_WHICH, and will have a non-null img_request
 251          * pointer.  The value of which will be in the range
 252          * 0..(img_request->obj_request_count-1).
 253          */
 254         union {
 255                 struct rbd_obj_request  *obj_request;   /* STAT op */
 256                 struct {
 257                         struct rbd_img_request  *img_request;
 258                         u64                     img_offset;
 259                         /* links for img_request->obj_requests list */
 260                         struct list_head        links;
 261                 };
 262         };
 263         u32                     which;          /* posn image request list */
 264
 265         enum obj_request_type   type;
 266         union {
 267                 struct bio      *bio_list;
 268                 struct {
 269                         struct page     **pages;
 270                         u32             page_count;
 271                 };
 272         };
 273         struct page             **copyup_pages;
 274         u32                     copyup_page_count;
 275
 276         struct ceph_osd_request *osd_req;
 277
 278         u64                     xferred;        /* bytes transferred */
 279         int                     result;
 280
 281         rbd_obj_callback_t      callback;
 282         struct completion       completion;
 283
 284         struct kref             kref;
 285 };
 286
 287 enum img_req_flags {
 288         IMG_REQ_WRITE,          /* I/O direction: read = 0, write = 1 */
 289         IMG_REQ_CHILD,          /* initiator: block = 0, child image = 1 */
 290         IMG_REQ_LAYERED,        /* ENOENT handling: normal = 0, layered = 1 */
 291         IMG_REQ_DISCARD,        /* discard: normal = 0, discard request = 1 */
 292 };
 293
 294 struct rbd_img_request {
 295         struct rbd_device       *rbd_dev;
 296         u64                     offset; /* starting image byte offset */
 297         u64                     length; /* byte count from offset */
 298         unsigned long           flags;
 299         union {
 300                 u64                     snap_id;        /* for reads */
 301                 struct ceph_snap_context *snapc;        /* for writes */
 302         };
 303         union {
 304                 struct request          *rq;            /* block request */
 305                 struct rbd_obj_request  *obj_request;   /* obj req initiator */
 306         };
 307         struct page             **copyup_pages;
 308         u32                     copyup_page_count;
 309         spinlock_t              completion_lock;/* protects next_completion */
 310         u32                     next_completion;
 311         rbd_img_callback_t      callback;
 312         u64                     xferred;/* aggregate bytes transferred */
 313         int                     result; /* first nonzero obj_request result */
 314
 315         u32                     obj_request_count;
 316         struct list_head        obj_requests;   /* rbd_obj_request structs */
 317
 318         struct kref             kref;
 319 };
 320
 321 #define for_each_obj_request(ireq, oreq) \
 322         list_for_each_entry(oreq, &(ireq)->obj_requests, links)
 323 #define for_each_obj_request_from(ireq, oreq) \
 324         list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
 325 #define for_each_obj_request_safe(ireq, oreq, n) \
 326         list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
 327
 328 enum rbd_watch_state {
 329         RBD_WATCH_STATE_UNREGISTERED,
 330         RBD_WATCH_STATE_REGISTERED,
 331         RBD_WATCH_STATE_ERROR,
 332 };
 333
 334 enum rbd_lock_state {
 335         RBD_LOCK_STATE_UNLOCKED,
 336         RBD_LOCK_STATE_LOCKED,
 337         RBD_LOCK_STATE_RELEASING,
 338 };
 339
 340 /* WatchNotify::ClientId */
 341 struct rbd_client_id {
 342         u64 gid;
 343         u64 handle;
 344 };
 345
 346 struct rbd_mapping {
 347         u64                     size;
 348         u64                     features;
 349         bool                    read_only;
 350 };
 351
 352 /*
 353  * a single device
 354  */
 355 struct rbd_device {
 356         int                     dev_id;         /* blkdev unique id */
 357
 358         int                     major;          /* blkdev assigned major */
 359         int                     minor;
 360         struct gendisk          *disk;          /* blkdev's gendisk and rq */
 361
 362         u32                     image_format;   /* Either 1 or 2 */
 363         struct rbd_client       *rbd_client;
 364
 365         char                    name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
 366
 367         spinlock_t              lock;           /* queue, flags, open_count */
 368
 369         struct rbd_image_header header;
 370         unsigned long           flags;          /* possibly lock protected */
 371         struct rbd_spec         *spec;
 372         struct rbd_options      *opts;
 373         char                    *config_info;   /* add{,_single_major} string */
 374
 375         struct ceph_object_id   header_oid;
 376         struct ceph_object_locator header_oloc;
 377
 378         struct ceph_file_layout layout;         /* used for all rbd requests */
 379
 380         struct mutex            watch_mutex;
 381         enum rbd_watch_state    watch_state;
 382         struct ceph_osd_linger_request *watch_handle;
 383         u64                     watch_cookie;
 384         struct delayed_work     watch_dwork;
 385
 386         struct rw_semaphore     lock_rwsem;
 387         enum rbd_lock_state     lock_state;
 388         struct rbd_client_id    owner_cid;
 389         struct work_struct      acquired_lock_work;
 390         struct work_struct      released_lock_work;
 391         struct delayed_work     lock_dwork;
 392         struct work_struct      unlock_work;
 393         wait_queue_head_t       lock_waitq;
 394
 395         struct workqueue_struct *task_wq;
 396
 397         struct rbd_spec         *parent_spec;
 398         u64                     parent_overlap;
 399         atomic_t                parent_ref;
 400         struct rbd_device       *parent;
 401
 402         /* Block layer tags. */
 403         struct blk_mq_tag_set   tag_set;
 404
 405         /* protects updating the header */
 406         struct rw_semaphore     header_rwsem;
 407
 408         struct rbd_mapping      mapping;
 409
 410         struct list_head        node;
 411
 412         /* sysfs related */
 413         struct device           dev;
 414         unsigned long           open_count;     /* protected by lock */
 415 };
 416
 417 /*
 418  * Flag bits for rbd_dev->flags:
 419  * - REMOVING (which is coupled with rbd_dev->open_count) is protected
 420  *   by rbd_dev->lock
 421  * - BLACKLISTED is protected by rbd_dev->lock_rwsem
 422  */
 423 enum rbd_dev_flags {
 424         RBD_DEV_FLAG_EXISTS,    /* mapped snapshot has not been deleted */
 425         RBD_DEV_FLAG_REMOVING,  /* this mapping is being removed */
 426         RBD_DEV_FLAG_BLACKLISTED, /* our ceph_client is blacklisted */
 427 };
 428
 429 static DEFINE_MUTEX(client_mutex);      /* Serialize client creation */
 430
 431 static LIST_HEAD(rbd_dev_list);    /* devices */
 432 static DEFINE_SPINLOCK(rbd_dev_list_lock);
 433
 434 static LIST_HEAD(rbd_client_list);              /* clients */
 435 static DEFINE_SPINLOCK(rbd_client_list_lock);
 436
 437 /* Slab caches for frequently-allocated structures */
 438
 439 static struct kmem_cache        *rbd_img_request_cache;
 440 static struct kmem_cache        *rbd_obj_request_cache;
 441 static struct kmem_cache        *rbd_segment_name_cache;
 442
 443 static int rbd_major;
 444 static DEFINE_IDA(rbd_dev_id_ida);
 445
 446 static struct workqueue_struct *rbd_wq;
 447
 448 /*
 449  * Default to false for now, as single-major requires >= 0.75 version of
 450  * userspace rbd utility.
 451  */
 452 static bool single_major = false;
 453 module_param(single_major, bool, S_IRUGO);
 454 MODULE_PARM_DESC(single_major, "Use a single major number for all rbd devices (default: false)");
 455
 456 static int rbd_img_request_submit(struct rbd_img_request *img_request);
 457
 458 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
 459                        size_t count);
 460 static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
 461                           size_t count);
 462 static ssize_t rbd_add_single_major(struct bus_type *bus, const char *buf,
 463                                     size_t count);
 464 static ssize_t rbd_remove_single_major(struct bus_type *bus, const char *buf,
 465                                        size_t count);
 466 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth);
 467 static void rbd_spec_put(struct rbd_spec *spec);
 468
 469 static int rbd_dev_id_to_minor(int dev_id)
 470 {
 471         return dev_id << RBD_SINGLE_MAJOR_PART_SHIFT;
 472 }
 473
 474 static int minor_to_rbd_dev_id(int minor)
 475 {
 476         return minor >> RBD_SINGLE_MAJOR_PART_SHIFT;
 477 }
 478
 479 static bool rbd_is_lock_supported(struct rbd_device *rbd_dev)
 480 {
 481         return (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) &&
 482                rbd_dev->spec->snap_id == CEPH_NOSNAP &&
 483                !rbd_dev->mapping.read_only;
 484 }
 485
 486 static bool __rbd_is_lock_owner(struct rbd_device *rbd_dev)
 487 {
 488         return rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED ||
 489                rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING;
 490 }
 491
 492 static bool rbd_is_lock_owner(struct rbd_device *rbd_dev)
 493 {
 494         bool is_lock_owner;
 495
 496         down_read(&rbd_dev->lock_rwsem);
 497         is_lock_owner = __rbd_is_lock_owner(rbd_dev);
 498         up_read(&rbd_dev->lock_rwsem);
 499         return is_lock_owner;
 500 }
 501
 502 static BUS_ATTR(add, S_IWUSR, NULL, rbd_add);
 503 static BUS_ATTR(remove, S_IWUSR, NULL, rbd_remove);
 504 static BUS_ATTR(add_single_major, S_IWUSR, NULL, rbd_add_single_major);
 505 static BUS_ATTR(remove_single_major, S_IWUSR, NULL, rbd_remove_single_major);
 506
 507 static struct attribute *rbd_bus_attrs[] = {
 508         &bus_attr_add.attr,
 509         &bus_attr_remove.attr,
 510         &bus_attr_add_single_major.attr,
 511         &bus_attr_remove_single_major.attr,
 512         NULL,
 513 };
 514
 515 static umode_t rbd_bus_is_visible(struct kobject *kobj,
 516                                   struct attribute *attr, int index)
 517 {
 518         if (!single_major &&
 519             (attr == &bus_attr_add_single_major.attr ||
 520              attr == &bus_attr_remove_single_major.attr))
 521                 return 0;
 522
 523         return attr->mode;
 524 }
 525
 526 static const struct attribute_group rbd_bus_group = {
 527         .attrs = rbd_bus_attrs,
 528         .is_visible = rbd_bus_is_visible,
 529 };
 530 __ATTRIBUTE_GROUPS(rbd_bus);
 531
 532 static struct bus_type rbd_bus_type = {
 533         .name           = "rbd",
 534         .bus_groups     = rbd_bus_groups,
 535 };
 536
 537 static void rbd_root_dev_release(struct device *dev)
 538 {
 539 }
 540
 541 static struct device rbd_root_dev = {
 542         .init_name =    "rbd",
 543         .release =      rbd_root_dev_release,
 544 };
 545
 546 static __printf(2, 3)
 547 void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
 548 {
 549         struct va_format vaf;
 550         va_list args;
 551
 552         va_start(args, fmt);
 553         vaf.fmt = fmt;
 554         vaf.va = &args;
 555
 556         if (!rbd_dev)
 557                 printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
 558         else if (rbd_dev->disk)
 559                 printk(KERN_WARNING "%s: %s: %pV\n",
 560                         RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
 561         else if (rbd_dev->spec && rbd_dev->spec->image_name)
 562                 printk(KERN_WARNING "%s: image %s: %pV\n",
 563                         RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
 564         else if (rbd_dev->spec && rbd_dev->spec->image_id)
 565                 printk(KERN_WARNING "%s: id %s: %pV\n",
 566                         RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
 567         else    /* punt */
 568                 printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
 569                         RBD_DRV_NAME, rbd_dev, &vaf);
 570         va_end(args);
 571 }
 572
 573 #ifdef RBD_DEBUG
 574 #define rbd_assert(expr)                                                \
 575                 if (unlikely(!(expr))) {                                \
 576                         printk(KERN_ERR "\nAssertion failure in %s() "  \
 577                                                 "at line %d:\n\n"       \
 578                                         "\trbd_assert(%s);\n\n",        \
 579                                         __func__, __LINE__, #expr);     \
 580                         BUG();                                          \
 581                 }
 582 #else /* !RBD_DEBUG */
 583 #  define rbd_assert(expr)      ((void) 0)
 584 #endif /* !RBD_DEBUG */
 585
 586 static void rbd_osd_copyup_callback(struct rbd_obj_request *obj_request);
 587 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
 588 static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
 589 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
 590
 591 static int rbd_dev_refresh(struct rbd_device *rbd_dev);
 592 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
 593 static int rbd_dev_header_info(struct rbd_device *rbd_dev);
 594 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev);
 595 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
 596                                         u64 snap_id);
 597 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
 598                                 u8 *order, u64 *snap_size);
 599 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
 600                 u64 *snap_features);
 601
 602 static int rbd_open(struct block_device *bdev, fmode_t mode)
 603 {
 604         struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
 605         bool removing = false;
 606
 607         if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
 608                 return -EROFS;
 609
 610         spin_lock_irq(&rbd_dev->lock);
 611         if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
 612                 removing = true;
 613         else
 614                 rbd_dev->open_count++;
 615         spin_unlock_irq(&rbd_dev->lock);
 616         if (removing)
 617                 return -ENOENT;
 618
 619         (void) get_device(&rbd_dev->dev);
 620
 621         return 0;
 622 }
 623
 624 static void rbd_release(struct gendisk *disk, fmode_t mode)
 625 {
 626         struct rbd_device *rbd_dev = disk->private_data;
 627         unsigned long open_count_before;
 628
 629         spin_lock_irq(&rbd_dev->lock);
 630         open_count_before = rbd_dev->open_count--;
 631         spin_unlock_irq(&rbd_dev->lock);
 632         rbd_assert(open_count_before > 0);
 633
 634         put_device(&rbd_dev->dev);
 635 }
 636
 637 static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
 638 {
 639         int ret = 0;
 640         int val;
 641         bool ro;
 642         bool ro_changed = false;
 643
 644         /* get_user() may sleep, so call it before taking rbd_dev->lock */
 645         if (get_user(val, (int __user *)(arg)))
 646                 return -EFAULT;
 647
 648         ro = val ? true : false;
 649         /* Snapshot doesn't allow to write*/
 650         if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro)
 651                 return -EROFS;
 652
 653         spin_lock_irq(&rbd_dev->lock);
 654         /* prevent others open this device */
 655         if (rbd_dev->open_count > 1) {
 656                 ret = -EBUSY;
 657                 goto out;
 658         }
 659
 660         if (rbd_dev->mapping.read_only != ro) {
 661                 rbd_dev->mapping.read_only = ro;
 662                 ro_changed = true;
 663         }
 664
 665 out:
 666         spin_unlock_irq(&rbd_dev->lock);
 667         /* set_disk_ro() may sleep, so call it after releasing rbd_dev->lock */
 668         if (ret == 0 && ro_changed)
 669                 set_disk_ro(rbd_dev->disk, ro ? 1 : 0);
 670
 671         return ret;
 672 }
 673
 674 static int rbd_ioctl(struct block_device *bdev, fmode_t mode,
 675                         unsigned int cmd, unsigned long arg)
 676 {
 677         struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
 678         int ret = 0;
 679
 680         switch (cmd) {
 681         case BLKROSET:
 682                 ret = rbd_ioctl_set_ro(rbd_dev, arg);
 683                 break;
 684         default:
 685                 ret = -ENOTTY;
 686         }
 687
 688         return ret;
 689 }
 690
 691 #ifdef CONFIG_COMPAT
 692 static int rbd_compat_ioctl(struct block_device *bdev, fmode_t mode,
 693                                 unsigned int cmd, unsigned long arg)
 694 {
 695         return rbd_ioctl(bdev, mode, cmd, arg);
 696 }
 697 #endif /* CONFIG_COMPAT */
 698
 699 static const struct block_device_operations rbd_bd_ops = {
 700         .owner                  = THIS_MODULE,
 701         .open                   = rbd_open,
 702         .release                = rbd_release,
 703         .ioctl                  = rbd_ioctl,
 704 #ifdef CONFIG_COMPAT
 705         .compat_ioctl           = rbd_compat_ioctl,
 706 #endif
 707 };
 708
 709 /*
 710  * Initialize an rbd client instance.  Success or not, this function
 711  * consumes ceph_opts.  Caller holds client_mutex.
 712  */
 713 static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
 714 {
 715         struct rbd_client *rbdc;
 716         int ret = -ENOMEM;
 717
 718         dout("%s:\n", __func__);
 719         rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
 720         if (!rbdc)
 721                 goto out_opt;
 722
 723         kref_init(&rbdc->kref);
 724         INIT_LIST_HEAD(&rbdc->node);
 725
 726         rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
 727         if (IS_ERR(rbdc->client))
 728                 goto out_rbdc;
 729         ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
 730
 731         ret = ceph_open_session(rbdc->client);
 732         if (ret < 0)
 733                 goto out_client;
 734
 735         spin_lock(&rbd_client_list_lock);
 736         list_add_tail(&rbdc->node, &rbd_client_list);
 737         spin_unlock(&rbd_client_list_lock);
 738
 739         dout("%s: rbdc %p\n", __func__, rbdc);
 740
 741         return rbdc;
 742 out_client:
 743         ceph_destroy_client(rbdc->client);
 744 out_rbdc:
 745         kfree(rbdc);
 746 out_opt:
 747         if (ceph_opts)
 748                 ceph_destroy_options(ceph_opts);
 749         dout("%s: error %d\n", __func__, ret);
 750
 751         return ERR_PTR(ret);
 752 }
 753
 754 static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
 755 {
 756         kref_get(&rbdc->kref);
 757
 758         return rbdc;
 759 }
 760
 761 /*
 762  * Find a ceph client with specific addr and configuration.  If
 763  * found, bump its reference count.
 764  */
 765 static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
 766 {
 767         struct rbd_client *client_node;
 768         bool found = false;
 769
 770         if (ceph_opts->flags & CEPH_OPT_NOSHARE)
 771                 return NULL;
 772
 773         spin_lock(&rbd_client_list_lock);
 774         list_for_each_entry(client_node, &rbd_client_list, node) {
 775                 if (!ceph_compare_options(ceph_opts, client_node->client)) {
 776                         __rbd_get_client(client_node);
 777
 778                         found = true;
 779                         break;
 780                 }
 781         }
 782         spin_unlock(&rbd_client_list_lock);
 783
 784         return found ? client_node : NULL;
 785 }
 786
 787 /*
 788  * (Per device) rbd map options
 789  */
 790 enum {
 791         Opt_queue_depth,
 792         Opt_last_int,
 793         /* int args above */
 794         Opt_last_string,
 795         /* string args above */
 796         Opt_read_only,
 797         Opt_read_write,
 798         Opt_lock_on_read,
 799         Opt_err
 800 };
 801
 802 static match_table_t rbd_opts_tokens = {
 803         {Opt_queue_depth, "queue_depth=%d"},
 804         /* int args above */
 805         /* string args above */
 806         {Opt_read_only, "read_only"},
 807         {Opt_read_only, "ro"},          /* Alternate spelling */
 808         {Opt_read_write, "read_write"},
 809         {Opt_read_write, "rw"},         /* Alternate spelling */
 810         {Opt_lock_on_read, "lock_on_read"},
 811         {Opt_err, NULL}
 812 };
 813
 814 struct rbd_options {
 815         int     queue_depth;
 816         bool    read_only;
 817         bool    lock_on_read;
 818 };
 819
 820 #define RBD_QUEUE_DEPTH_DEFAULT BLKDEV_MAX_RQ
 821 #define RBD_READ_ONLY_DEFAULT   false
 822 #define RBD_LOCK_ON_READ_DEFAULT false
 823
 824 static int parse_rbd_opts_token(char *c, void *private)
 825 {
 826         struct rbd_options *rbd_opts = private;
 827         substring_t argstr[MAX_OPT_ARGS];
 828         int token, intval, ret;
 829
 830         token = match_token(c, rbd_opts_tokens, argstr);
 831         if (token < Opt_last_int) {
 832                 ret = match_int(&argstr[0], &intval);
 833                 if (ret < 0) {
 834                         pr_err("bad mount option arg (not int) at '%s'\n", c);
 835                         return ret;
 836                 }
 837                 dout("got int token %d val %d\n", token, intval);
 838         } else if (token > Opt_last_int && token < Opt_last_string) {
 839                 dout("got string token %d val %s\n", token, argstr[0].from);
 840         } else {
 841                 dout("got token %d\n", token);
 842         }
 843
 844         switch (token) {
 845         case Opt_queue_depth:
 846                 if (intval < 1) {
 847                         pr_err("queue_depth out of range\n");
 848                         return -EINVAL;
 849                 }
 850                 rbd_opts->queue_depth = intval;
 851                 break;
 852         case Opt_read_only:
 853                 rbd_opts->read_only = true;
 854                 break;
 855         case Opt_read_write:
 856                 rbd_opts->read_only = false;
 857                 break;
 858         case Opt_lock_on_read:
 859                 rbd_opts->lock_on_read = true;
 860                 break;
 861         default:
 862                 /* libceph prints "bad option" msg */
 863                 return -EINVAL;
 864         }
 865
 866         return 0;
 867 }
 868
 869 static char* obj_op_name(enum obj_operation_type op_type)
 870 {
 871         switch (op_type) {
 872         case OBJ_OP_READ:
 873                 return "read";
 874         case OBJ_OP_WRITE:
 875                 return "write";
 876         case OBJ_OP_DISCARD:
 877                 return "discard";
 878         default:
 879                 return "???";
 880         }
 881 }
 882
 883 /*
 884  * Get a ceph client with specific addr and configuration, if one does
 885  * not exist create it.  Either way, ceph_opts is consumed by this
 886  * function.
 887  */
 888 static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
 889 {
 890         struct rbd_client *rbdc;
 891
 892         mutex_lock_nested(&client_mutex, SINGLE_DEPTH_NESTING);
 893         rbdc = rbd_client_find(ceph_opts);
 894         if (rbdc)       /* using an existing client */
 895                 ceph_destroy_options(ceph_opts);
 896         else
 897                 rbdc = rbd_client_create(ceph_opts);
 898         mutex_unlock(&client_mutex);
 899
 900         return rbdc;
 901 }
 902
 903 /*
 904  * Destroy ceph client
 905  *
 906  * Caller must hold rbd_client_list_lock.
 907  */
 908 static void rbd_client_release(struct kref *kref)
 909 {
 910         struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);
 911
 912         dout("%s: rbdc %p\n", __func__, rbdc);
 913         spin_lock(&rbd_client_list_lock);
 914         list_del(&rbdc->node);
 915         spin_unlock(&rbd_client_list_lock);
 916
 917         ceph_destroy_client(rbdc->client);
 918         kfree(rbdc);
 919 }
 920
 921 /*
 922  * Drop reference to ceph client node. If it's not referenced anymore, release
 923  * it.
 924  */
 925 static void rbd_put_client(struct rbd_client *rbdc)
 926 {
 927         if (rbdc)
 928                 kref_put(&rbdc->kref, rbd_client_release);
 929 }
 930
 931 static bool rbd_image_format_valid(u32 image_format)
 932 {
 933         return image_format == 1 || image_format == 2;
 934 }
 935
 936 static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
 937 {
 938         size_t size;
 939         u32 snap_count;
 940
 941         /* The header has to start with the magic rbd header text */
 942         if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
 943                 return false;
 944
 945         /* The bio layer requires at least sector-sized I/O */
 946
 947         if (ondisk->options.order < SECTOR_SHIFT)
 948                 return false;
 949
 950         /* If we use u64 in a few spots we may be able to loosen this */
 951
 952         if (ondisk->options.order > 8 * sizeof (int) - 1)
 953                 return false;
 954
 955         /*
 956          * The size of a snapshot header has to fit in a size_t, and
 957          * that limits the number of snapshots.
 958          */
 959         snap_count = le32_to_cpu(ondisk->snap_count);
 960         size = SIZE_MAX - sizeof (struct ceph_snap_context);
 961         if (snap_count > size / sizeof (__le64))
 962                 return false;
 963
 964         /*
 965          * Not only that, but the size of the entire the snapshot
 966          * header must also be representable in a size_t.
 967          */
 968         size -= snap_count * sizeof (__le64);
 969         if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
 970                 return false;
 971
 972         return true;
 973 }
 974
 975 /*
 976  * Fill an rbd image header with information from the given format 1
 977  * on-disk header.
 978  */
 979 static int rbd_header_from_disk(struct rbd_device *rbd_dev,
 980                                  struct rbd_image_header_ondisk *ondisk)
 981 {
 982         struct rbd_image_header *header = &rbd_dev->header;
 983         bool first_time = header->object_prefix == NULL;
 984         struct ceph_snap_context *snapc;
 985         char *object_prefix = NULL;
 986         char *snap_names = NULL;
 987         u64 *snap_sizes = NULL;
 988         u32 snap_count;
 989         int ret = -ENOMEM;
 990         u32 i;
 991
 992         /* Allocate this now to avoid having to handle failure below */
 993
 994         if (first_time) {
 995                 size_t len;
 996
 997                 len = strnlen(ondisk->object_prefix,
 998                                 sizeof (ondisk->object_prefix));
 999                 object_prefix = kmalloc(len + 1, GFP_KERNEL);
1000                 if (!object_prefix)
1001                         return -ENOMEM;
1002                 memcpy(object_prefix, ondisk->object_prefix, len);
1003                 object_prefix[len] = '\0';
1004         }
1005
1006         /* Allocate the snapshot context and fill it in */
1007
1008         snap_count = le32_to_cpu(ondisk->snap_count);
1009         snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
1010         if (!snapc)
1011                 goto out_err;
1012         snapc->seq = le64_to_cpu(ondisk->snap_seq);
1013         if (snap_count) {
1014                 struct rbd_image_snap_ondisk *snaps;
1015                 u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
1016
1017                 /* We'll keep a copy of the snapshot names... */
1018
1019                 if (snap_names_len > (u64)SIZE_MAX)
1020                         goto out_2big;
1021                 snap_names = kmalloc(snap_names_len, GFP_KERNEL);
1022                 if (!snap_names)
1023                         goto out_err;
1024
1025                 /* ...as well as the array of their sizes. */
1026                 snap_sizes = kmalloc_array(snap_count,
1027                                            sizeof(*header->snap_sizes),
1028                                            GFP_KERNEL);
1029                 if (!snap_sizes)
1030                         goto out_err;
1031
1032                 /*
1033                  * Copy the names, and fill in each snapshot's id
1034                  * and size.
1035                  *
1036                  * Note that rbd_dev_v1_header_info() guarantees the
1037                  * ondisk buffer we're working with has
1038                  * snap_names_len bytes beyond the end of the
1039                  * snapshot id array, this memcpy() is safe.
1040                  */
1041                 memcpy(snap_names, &ondisk->snaps[snap_count], snap_names_len);
1042                 snaps = ondisk->snaps;
1043                 for (i = 0; i < snap_count; i++) {
1044                         snapc->snaps[i] = le64_to_cpu(snaps[i].id);
1045                         snap_sizes[i] = le64_to_cpu(snaps[i].image_size);
1046                 }
1047         }
1048
1049         /* We won't fail any more, fill in the header */
1050
1051         if (first_time) {
1052                 header->object_prefix = object_prefix;
1053                 header->obj_order = ondisk->options.order;
1054                 header->crypt_type = ondisk->options.crypt_type;
1055                 header->comp_type = ondisk->options.comp_type;
1056                 /* The rest aren't used for format 1 images */
1057                 header->stripe_unit = 0;
1058                 header->stripe_count = 0;
1059                 header->features = 0;
1060         } else {
1061                 ceph_put_snap_context(header->snapc);
1062                 kfree(header->snap_names);
1063                 kfree(header->snap_sizes);
1064         }
1065
1066         /* The remaining fields always get updated (when we refresh) */
1067
1068         header->image_size = le64_to_cpu(ondisk->image_size);
1069         header->snapc = snapc;
1070         header->snap_names = snap_names;
1071         header->snap_sizes = snap_sizes;
1072
1073         return 0;
1074 out_2big:
1075         ret = -EIO;
1076 out_err:
1077         kfree(snap_sizes);
1078         kfree(snap_names);
1079         ceph_put_snap_context(snapc);
1080         kfree(object_prefix);
1081
1082         return ret;
1083 }
1084
1085 static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which)
1086 {
1087         const char *snap_name;
1088
1089         rbd_assert(which < rbd_dev->header.snapc->num_snaps);
1090
1091         /* Skip over names until we find the one we are looking for */
1092
1093         snap_name = rbd_dev->header.snap_names;
1094         while (which--)
1095                 snap_name += strlen(snap_name) + 1;
1096
1097         return kstrdup(snap_name, GFP_KERNEL);
1098 }
1099
1100 /*
1101  * Snapshot id comparison function for use with qsort()/bsearch().
1102  * Note that result is for snapshots in *descending* order.
1103  */
1104 static int snapid_compare_reverse(const void *s1, const void *s2)
1105 {
1106         u64 snap_id1 = *(u64 *)s1;
1107         u64 snap_id2 = *(u64 *)s2;
1108
1109         if (snap_id1 < snap_id2)
1110                 return 1;
1111         return snap_id1 == snap_id2 ? 0 : -1;
1112 }
1113
1114 /*
1115  * Search a snapshot context to see if the given snapshot id is
1116  * present.
1117  *
1118  * Returns the position of the snapshot id in the array if it's found,
1119  * or BAD_SNAP_INDEX otherwise.
1120  *
1121  * Note: The snapshot array is in kept sorted (by the osd) in
1122  * reverse order, highest snapshot id first.
1123  */
1124 static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
1125 {
1126         struct ceph_snap_context *snapc = rbd_dev->header.snapc;
1127         u64 *found;
1128
1129         found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
1130                                 sizeof (snap_id), snapid_compare_reverse);
1131
1132         return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
1133 }
1134
1135 static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
1136                                         u64 snap_id)
1137 {
1138         u32 which;
1139         const char *snap_name;
1140
1141         which = rbd_dev_snap_index(rbd_dev, snap_id);
1142         if (which == BAD_SNAP_INDEX)
1143                 return ERR_PTR(-ENOENT);
1144
1145         snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
1146         return snap_name ? snap_name : ERR_PTR(-ENOMEM);
1147 }
1148
1149 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
1150 {
1151         if (snap_id == CEPH_NOSNAP)
1152                 return RBD_SNAP_HEAD_NAME;
1153
1154         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
1155         if (rbd_dev->image_format == 1)
1156                 return rbd_dev_v1_snap_name(rbd_dev, snap_id);
1157
1158         return rbd_dev_v2_snap_name(rbd_dev, snap_id);
1159 }
1160
1161 static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
1162                                 u64 *snap_size)
1163 {
1164         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
1165         if (snap_id == CEPH_NOSNAP) {
1166                 *snap_size = rbd_dev->header.image_size;
1167         } else if (rbd_dev->image_format == 1) {
1168                 u32 which;
1169
1170                 which = rbd_dev_snap_index(rbd_dev, snap_id);
1171                 if (which == BAD_SNAP_INDEX)
1172                         return -ENOENT;
1173
1174                 *snap_size = rbd_dev->header.snap_sizes[which];
1175         } else {
1176                 u64 size = 0;
1177                 int ret;
1178
1179                 ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
1180                 if (ret)
1181                         return ret;
1182
1183                 *snap_size = size;
1184         }
1185         return 0;
1186 }
1187
1188 static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
1189                         u64 *snap_features)
1190 {
1191         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
1192         if (snap_id == CEPH_NOSNAP) {
1193                 *snap_features = rbd_dev->header.features;
1194         } else if (rbd_dev->image_format == 1) {
1195                 *snap_features = 0;     /* No features for format 1 */
1196         } else {
1197                 u64 features = 0;
1198                 int ret;
1199
1200                 ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, &features);
1201                 if (ret)
1202                         return ret;
1203
1204                 *snap_features = features;
1205         }
1206         return 0;
1207 }
1208
1209 static int rbd_dev_mapping_set(struct rbd_device *rbd_dev)
1210 {
1211         u64 snap_id = rbd_dev->spec->snap_id;
1212         u64 size = 0;
1213         u64 features = 0;
1214         int ret;
1215
1216         ret = rbd_snap_size(rbd_dev, snap_id, &size);
1217         if (ret)
1218                 return ret;
1219         ret = rbd_snap_features(rbd_dev, snap_id, &features);
1220         if (ret)
1221                 return ret;
1222
1223         rbd_dev->mapping.size = size;
1224         rbd_dev->mapping.features = features;
1225
1226         return 0;
1227 }
1228
1229 static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
1230 {
1231         rbd_dev->mapping.size = 0;
1232         rbd_dev->mapping.features = 0;
1233 }
1234
1235 static void rbd_segment_name_free(const char *name)
1236 {
1237         /* The explicit cast here is needed to drop the const qualifier */
1238
1239         kmem_cache_free(rbd_segment_name_cache, (void *)name);
1240 }
1241
1242 static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
1243 {
1244         char *name;
1245         u64 segment;
1246         int ret;
1247         char *name_format;
1248
1249         name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
1250         if (!name)
1251                 return NULL;
1252         segment = offset >> rbd_dev->header.obj_order;
1253         name_format = "%s.%012llx";
1254         if (rbd_dev->image_format == 2)
1255                 name_format = "%s.%016llx";
1256         ret = snprintf(name, CEPH_MAX_OID_NAME_LEN + 1, name_format,
1257                         rbd_dev->header.object_prefix, segment);
1258         if (ret < 0 || ret > CEPH_MAX_OID_NAME_LEN) {
1259                 pr_err("error formatting segment name for #%llu (%d)\n",
1260                         segment, ret);
1261                 rbd_segment_name_free(name);
1262                 name = NULL;
1263         }
1264
1265         return name;
1266 }
1267
1268 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
1269 {
1270         u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1271
1272         return offset & (segment_size - 1);
1273 }
1274
1275 static u64 rbd_segment_length(struct rbd_device *rbd_dev,
1276                                 u64 offset, u64 length)
1277 {
1278         u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1279
1280         offset &= segment_size - 1;
1281
1282         rbd_assert(length <= U64_MAX - offset);
1283         if (offset + length > segment_size)
1284                 length = segment_size - offset;
1285
1286         return length;
1287 }
1288
1289 /*
1290  * returns the size of an object in the image
1291  */
1292 static u64 rbd_obj_bytes(struct rbd_image_header *header)
1293 {
1294         return 1 << header->obj_order;
1295 }
1296
1297 /*
1298  * bio helpers
1299  */
1300
1301 static void bio_chain_put(struct bio *chain)
1302 {
1303         struct bio *tmp;
1304
1305         while (chain) {
1306                 tmp = chain;
1307                 chain = chain->bi_next;
1308                 bio_put(tmp);
1309         }
1310 }
1311
1312 /*
1313  * zeros a bio chain, starting at specific offset
1314  */
1315 static void zero_bio_chain(struct bio *chain, int start_ofs)
1316 {
1317         struct bio_vec bv;
1318         struct bvec_iter iter;
1319         unsigned long flags;
1320         void *buf;
1321         int pos = 0;
1322
1323         while (chain) {
1324                 bio_for_each_segment(bv, chain, iter) {
1325                         if (pos + bv.bv_len > start_ofs) {
1326                                 int remainder = max(start_ofs - pos, 0);
1327                                 buf = bvec_kmap_irq(&bv, &flags);
1328                                 memset(buf + remainder, 0,
1329                                        bv.bv_len - remainder);
1330                                 flush_dcache_page(bv.bv_page);
1331                                 bvec_kunmap_irq(buf, &flags);
1332                         }
1333                         pos += bv.bv_len;
1334                 }
1335
1336                 chain = chain->bi_next;
1337         }
1338 }
1339
1340 /*
1341  * similar to zero_bio_chain(), zeros data defined by a page array,
1342  * starting at the given byte offset from the start of the array and
1343  * continuing up to the given end offset.  The pages array is
1344  * assumed to be big enough to hold all bytes up to the end.
1345  */
1346 static void zero_pages(struct page **pages, u64 offset, u64 end)
1347 {
1348         struct page **page = &pages[offset >> PAGE_SHIFT];
1349
1350         rbd_assert(end > offset);
1351         rbd_assert(end - offset <= (u64)SIZE_MAX);
1352         while (offset < end) {
1353                 size_t page_offset;
1354                 size_t length;
1355                 unsigned long flags;
1356                 void *kaddr;
1357
1358                 page_offset = offset & ~PAGE_MASK;
1359                 length = min_t(size_t, PAGE_SIZE - page_offset, end - offset);
1360                 local_irq_save(flags);
1361                 kaddr = kmap_atomic(*page);
1362                 memset(kaddr + page_offset, 0, length);
1363                 flush_dcache_page(*page);
1364                 kunmap_atomic(kaddr);
1365                 local_irq_restore(flags);
1366
1367                 offset += length;
1368                 page++;
1369         }
1370 }
1371
1372 /*
1373  * Clone a portion of a bio, starting at the given byte offset
1374  * and continuing for the number of bytes indicated.
1375  */
1376 static struct bio *bio_clone_range(struct bio *bio_src,
1377                                         unsigned int offset,
1378                                         unsigned int len,
1379                                         gfp_t gfpmask)
1380 {
1381         struct bio *bio;
1382
1383         bio = bio_clone(bio_src, gfpmask);
1384         if (!bio)
1385                 return NULL;    /* ENOMEM */
1386
1387         bio_advance(bio, offset);
1388         bio->bi_iter.bi_size = len;
1389
1390         return bio;
1391 }
1392
1393 /*
1394  * Clone a portion of a bio chain, starting at the given byte offset
1395  * into the first bio in the source chain and continuing for the
1396  * number of bytes indicated.  The result is another bio chain of
1397  * exactly the given length, or a null pointer on error.
1398  *
1399  * The bio_src and offset parameters are both in-out.  On entry they
1400  * refer to the first source bio and the offset into that bio where
1401  * the start of data to be cloned is located.
1402  *
1403  * On return, bio_src is updated to refer to the bio in the source
1404  * chain that contains first un-cloned byte, and *offset will
1405  * contain the offset of that byte within that bio.
1406  */
1407 static struct bio *bio_chain_clone_range(struct bio **bio_src,
1408                                         unsigned int *offset,
1409                                         unsigned int len,
1410                                         gfp_t gfpmask)
1411 {
1412         struct bio *bi = *bio_src;
1413         unsigned int off = *offset;
1414         struct bio *chain = NULL;
1415         struct bio **end;
1416
1417         /* Build up a chain of clone bios up to the limit */
1418
1419         if (!bi || off >= bi->bi_iter.bi_size || !len)
1420                 return NULL;            /* Nothing to clone */
1421
1422         end = &chain;
1423         while (len) {
1424                 unsigned int bi_size;
1425                 struct bio *bio;
1426
1427                 if (!bi) {
1428                         rbd_warn(NULL, "bio_chain exhausted with %u left", len);
1429                         goto out_err;   /* EINVAL; ran out of bio's */
1430                 }
1431                 bi_size = min_t(unsigned int, bi->bi_iter.bi_size - off, len);
1432                 bio = bio_clone_range(bi, off, bi_size, gfpmask);
1433                 if (!bio)
1434                         goto out_err;   /* ENOMEM */
1435
1436                 *end = bio;
1437                 end = &bio->bi_next;
1438
1439                 off += bi_size;
1440                 if (off == bi->bi_iter.bi_size) {
1441                         bi = bi->bi_next;
1442                         off = 0;
1443                 }
1444                 len -= bi_size;
1445         }
1446         *bio_src = bi;
1447         *offset = off;
1448
1449         return chain;
1450 out_err:
1451         bio_chain_put(chain);
1452
1453         return NULL;
1454 }
1455
1456 /*
1457  * The default/initial value for all object request flags is 0.  For
1458  * each flag, once its value is set to 1 it is never reset to 0
1459  * again.
1460  */
1461 static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1462 {
1463         if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1464                 struct rbd_device *rbd_dev;
1465
1466                 rbd_dev = obj_request->img_request->rbd_dev;
1467                 rbd_warn(rbd_dev, "obj_request %p already marked img_data",
1468                         obj_request);
1469         }
1470 }
1471
1472 static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1473 {
1474         smp_mb();
1475         return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1476 }
1477
1478 static void obj_request_done_set(struct rbd_obj_request *obj_request)
1479 {
1480         if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
1481                 struct rbd_device *rbd_dev = NULL;
1482
1483                 if (obj_request_img_data_test(obj_request))
1484                         rbd_dev = obj_request->img_request->rbd_dev;
1485                 rbd_warn(rbd_dev, "obj_request %p already marked done",
1486                         obj_request);
1487         }
1488 }
1489
1490 static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1491 {
1492         smp_mb();
1493         return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1494 }
1495
1496 /*
1497  * This sets the KNOWN flag after (possibly) setting the EXISTS
1498  * flag.  The latter is set based on the "exists" value provided.
1499  *
1500  * Note that for our purposes once an object exists it never goes
1501  * away again.  It's possible that the response from two existence
1502  * checks are separated by the creation of the target object, and
1503  * the first ("doesn't exist") response arrives *after* the second
1504  * ("does exist").  In that case we ignore the second one.
1505  */
1506 static void obj_request_existence_set(struct rbd_obj_request *obj_request,
1507                                 bool exists)
1508 {
1509         if (exists)
1510                 set_bit(OBJ_REQ_EXISTS, &obj_request->flags);
1511         set_bit(OBJ_REQ_KNOWN, &obj_request->flags);
1512         smp_mb();
1513 }
1514
1515 static bool obj_request_known_test(struct rbd_obj_request *obj_request)
1516 {
1517         smp_mb();
1518         return test_bit(OBJ_REQ_KNOWN, &obj_request->flags) != 0;
1519 }
1520
1521 static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
1522 {
1523         smp_mb();
1524         return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
1525 }
1526
1527 static bool obj_request_overlaps_parent(struct rbd_obj_request *obj_request)
1528 {
1529         struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
1530
1531         return obj_request->img_offset <
1532             round_up(rbd_dev->parent_overlap, rbd_obj_bytes(&rbd_dev->header));
1533 }
1534
1535 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
1536 {
1537         dout("%s: obj %p (was %d)\n", __func__, obj_request,
1538                 kref_read(&obj_request->kref));
1539         kref_get(&obj_request->kref);
1540 }
1541
1542 static void rbd_obj_request_destroy(struct kref *kref);
1543 static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
1544 {
1545         rbd_assert(obj_request != NULL);
1546         dout("%s: obj %p (was %d)\n", __func__, obj_request,
1547                 kref_read(&obj_request->kref));
1548         kref_put(&obj_request->kref, rbd_obj_request_destroy);
1549 }
1550
1551 static void rbd_img_request_get(struct rbd_img_request *img_request)
1552 {
1553         dout("%s: img %p (was %d)\n", __func__, img_request,
1554              kref_read(&img_request->kref));
1555         kref_get(&img_request->kref);
1556 }
1557
1558 static bool img_request_child_test(struct rbd_img_request *img_request);
1559 static void rbd_parent_request_destroy(struct kref *kref);
1560 static void rbd_img_request_destroy(struct kref *kref);
1561 static void rbd_img_request_put(struct rbd_img_request *img_request)
1562 {
1563         rbd_assert(img_request != NULL);
1564         dout("%s: img %p (was %d)\n", __func__, img_request,
1565                 kref_read(&img_request->kref));
1566         if (img_request_child_test(img_request))
1567                 kref_put(&img_request->kref, rbd_parent_request_destroy);
1568         else
1569                 kref_put(&img_request->kref, rbd_img_request_destroy);
1570 }
1571
1572 static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
1573                                         struct rbd_obj_request *obj_request)
1574 {
1575         rbd_assert(obj_request->img_request == NULL);
1576
1577         /* Image request now owns object's original reference */
1578         obj_request->img_request = img_request;
1579         obj_request->which = img_request->obj_request_count;
1580         rbd_assert(!obj_request_img_data_test(obj_request));
1581         obj_request_img_data_set(obj_request);
1582         rbd_assert(obj_request->which != BAD_WHICH);
1583         img_request->obj_request_count++;
1584         list_add_tail(&obj_request->links, &img_request->obj_requests);
1585         dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1586                 obj_request->which);
1587 }
1588
1589 static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
1590                                         struct rbd_obj_request *obj_request)
1591 {
1592         rbd_assert(obj_request->which != BAD_WHICH);
1593
1594         dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1595                 obj_request->which);
1596         list_del(&obj_request->links);
1597         rbd_assert(img_request->obj_request_count > 0);
1598         img_request->obj_request_count--;
1599         rbd_assert(obj_request->which == img_request->obj_request_count);
1600         obj_request->which = BAD_WHICH;
1601         rbd_assert(obj_request_img_data_test(obj_request));
1602         rbd_assert(obj_request->img_request == img_request);
1603         obj_request->img_request = NULL;
1604         obj_request->callback = NULL;
1605         rbd_obj_request_put(obj_request);
1606 }
1607
1608 static bool obj_request_type_valid(enum obj_request_type type)
1609 {
1610         switch (type) {
1611         case OBJ_REQUEST_NODATA:
1612         case OBJ_REQUEST_BIO:
1613         case OBJ_REQUEST_PAGES:
1614                 return true;
1615         default:
1616                 return false;
1617         }
1618 }
1619
1620 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request);
1621
1622 static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
1623 {
1624         struct ceph_osd_request *osd_req = obj_request->osd_req;
1625
1626         dout("%s %p osd_req %p\n", __func__, obj_request, osd_req);
1627         if (obj_request_img_data_test(obj_request)) {
1628                 WARN_ON(obj_request->callback != rbd_img_obj_callback);
1629                 rbd_img_request_get(obj_request->img_request);
1630         }
1631         ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
1632 }
1633
1634 static void rbd_obj_request_end(struct rbd_obj_request *obj_request)
1635 {
1636         dout("%s %p\n", __func__, obj_request);
1637         ceph_osdc_cancel_request(obj_request->osd_req);
1638 }
1639
1640 /*
1641  * Wait for an object request to complete.  If interrupted, cancel the
1642  * underlying osd request.
1643  *
1644  * @timeout: in jiffies, 0 means "wait forever"
1645  */
1646 static int __rbd_obj_request_wait(struct rbd_obj_request *obj_request,
1647                                   unsigned long timeout)
1648 {
1649         long ret;
1650
1651         dout("%s %p\n", __func__, obj_request);
1652         ret = wait_for_completion_interruptible_timeout(
1653                                         &obj_request->completion,
1654                                         ceph_timeout_jiffies(timeout));
1655         if (ret <= 0) {
1656                 if (ret == 0)
1657                         ret = -ETIMEDOUT;
1658                 rbd_obj_request_end(obj_request);
1659         } else {
1660                 ret = 0;
1661         }
1662
1663         dout("%s %p ret %d\n", __func__, obj_request, (int)ret);
1664         return ret;
1665 }
1666
1667 static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
1668 {
1669         return __rbd_obj_request_wait(obj_request, 0);
1670 }
1671
1672 static void rbd_img_request_complete(struct rbd_img_request *img_request)
1673 {
1674
1675         dout("%s: img %p\n", __func__, img_request);
1676
1677         /*
1678          * If no error occurred, compute the aggregate transfer
1679          * count for the image request.  We could instead use
1680          * atomic64_cmpxchg() to update it as each object request
1681          * completes; not clear which way is better off hand.
1682          */
1683         if (!img_request->result) {
1684                 struct rbd_obj_request *obj_request;
1685                 u64 xferred = 0;
1686
1687                 for_each_obj_request(img_request, obj_request)
1688                         xferred += obj_request->xferred;
1689                 img_request->xferred = xferred;
1690         }
1691
1692         if (img_request->callback)
1693                 img_request->callback(img_request);
1694         else
1695                 rbd_img_request_put(img_request);
1696 }
1697
1698 /*
1699  * The default/initial value for all image request flags is 0.  Each
1700  * is conditionally set to 1 at image request initialization time
1701  * and currently never change thereafter.
1702  */
1703 static void img_request_write_set(struct rbd_img_request *img_request)
1704 {
1705         set_bit(IMG_REQ_WRITE, &img_request->flags);
1706         smp_mb();
1707 }
1708
1709 static bool img_request_write_test(struct rbd_img_request *img_request)
1710 {
1711         smp_mb();
1712         return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;
1713 }
1714
1715 /*
1716  * Set the discard flag when the img_request is an discard request
1717  */
1718 static void img_request_discard_set(struct rbd_img_request *img_request)
1719 {
1720         set_bit(IMG_REQ_DISCARD, &img_request->flags);
1721         smp_mb();
1722 }
1723
1724 static bool img_request_discard_test(struct rbd_img_request *img_request)
1725 {
1726         smp_mb();
1727         return test_bit(IMG_REQ_DISCARD, &img_request->flags) != 0;
1728 }
1729
1730 static void img_request_child_set(struct rbd_img_request *img_request)
1731 {
1732         set_bit(IMG_REQ_CHILD, &img_request->flags);
1733         smp_mb();
1734 }
1735
1736 static void img_request_child_clear(struct rbd_img_request *img_request)
1737 {
1738         clear_bit(IMG_REQ_CHILD, &img_request->flags);
1739         smp_mb();
1740 }
1741
1742 static bool img_request_child_test(struct rbd_img_request *img_request)
1743 {
1744         smp_mb();
1745         return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
1746 }
1747
1748 static void img_request_layered_set(struct rbd_img_request *img_request)
1749 {
1750         set_bit(IMG_REQ_LAYERED, &img_request->flags);
1751         smp_mb();
1752 }
1753
1754 static void img_request_layered_clear(struct rbd_img_request *img_request)
1755 {
1756         clear_bit(IMG_REQ_LAYERED, &img_request->flags);
1757         smp_mb();
1758 }
1759
1760 static bool img_request_layered_test(struct rbd_img_request *img_request)
1761 {
1762         smp_mb();
1763         return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
1764 }
1765
1766 static enum obj_operation_type
1767 rbd_img_request_op_type(struct rbd_img_request *img_request)
1768 {
1769         if (img_request_write_test(img_request))
1770                 return OBJ_OP_WRITE;
1771         else if (img_request_discard_test(img_request))
1772                 return OBJ_OP_DISCARD;
1773         else
1774                 return OBJ_OP_READ;
1775 }
1776
1777 static void
1778 rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
1779 {
1780         u64 xferred = obj_request->xferred;
1781         u64 length = obj_request->length;
1782
1783         dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1784                 obj_request, obj_request->img_request, obj_request->result,
1785                 xferred, length);
1786         /*
1787          * ENOENT means a hole in the image.  We zero-fill the entire
1788          * length of the request.  A short read also implies zero-fill
1789          * to the end of the request.  An error requires the whole
1790          * length of the request to be reported finished with an error
1791          * to the block layer.  In each case we update the xferred
1792          * count to indicate the whole request was satisfied.
1793          */
1794         rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1795         if (obj_request->result == -ENOENT) {
1796                 if (obj_request->type == OBJ_REQUEST_BIO)
1797                         zero_bio_chain(obj_request->bio_list, 0);
1798                 else
1799                         zero_pages(obj_request->pages, 0, length);
1800                 obj_request->result = 0;
1801         } else if (xferred < length && !obj_request->result) {
1802                 if (obj_request->type == OBJ_REQUEST_BIO)
1803                         zero_bio_chain(obj_request->bio_list, xferred);
1804                 else
1805                         zero_pages(obj_request->pages, xferred, length);
1806         }
1807         obj_request->xferred = length;
1808         obj_request_done_set(obj_request);
1809 }
1810
1811 static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
1812 {
1813         dout("%s: obj %p cb %p\n", __func__, obj_request,
1814                 obj_request->callback);
1815         if (obj_request->callback)
1816                 obj_request->callback(obj_request);
1817         else
1818                 complete_all(&obj_request->completion);
1819 }
1820
1821 static void rbd_obj_request_error(struct rbd_obj_request *obj_request, int err)
1822 {
1823         obj_request->result = err;
1824         obj_request->xferred = 0;
1825         /*
1826          * kludge - mirror rbd_obj_request_submit() to match a put in
1827          * rbd_img_obj_callback()
1828          */
1829         if (obj_request_img_data_test(obj_request)) {
1830                 WARN_ON(obj_request->callback != rbd_img_obj_callback);
1831                 rbd_img_request_get(obj_request->img_request);
1832         }
1833         obj_request_done_set(obj_request);
1834         rbd_obj_request_complete(obj_request);
1835 }
1836
1837 static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
1838 {
1839         struct rbd_img_request *img_request = NULL;
1840         struct rbd_device *rbd_dev = NULL;
1841         bool layered = false;
1842
1843         if (obj_request_img_data_test(obj_request)) {
1844                 img_request = obj_request->img_request;
1845                 layered = img_request && img_request_layered_test(img_request);
1846                 rbd_dev = img_request->rbd_dev;
1847         }
1848
1849         dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1850                 obj_request, img_request, obj_request->result,
1851                 obj_request->xferred, obj_request->length);
1852         if (layered && obj_request->result == -ENOENT &&
1853                         obj_request->img_offset < rbd_dev->parent_overlap)
1854                 rbd_img_parent_read(obj_request);
1855         else if (img_request)
1856                 rbd_img_obj_request_read_callback(obj_request);
1857         else
1858                 obj_request_done_set(obj_request);
1859 }
1860
1861 static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
1862 {
1863         dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1864                 obj_request->result, obj_request->length);
1865         /*
1866          * There is no such thing as a successful short write.  Set
1867          * it to our originally-requested length.
1868          */
1869         obj_request->xferred = obj_request->length;
1870         obj_request_done_set(obj_request);
1871 }
1872
1873 static void rbd_osd_discard_callback(struct rbd_obj_request *obj_request)
1874 {
1875         dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1876                 obj_request->result, obj_request->length);
1877         /*
1878          * There is no such thing as a successful short discard.  Set
1879          * it to our originally-requested length.
1880          */
1881         obj_request->xferred = obj_request->length;
1882         /* discarding a non-existent object is not a problem */
1883         if (obj_request->result == -ENOENT)
1884                 obj_request->result = 0;
1885         obj_request_done_set(obj_request);
1886 }
1887
1888 /*
1889  * For a simple stat call there's nothing to do.  We'll do more if
1890  * this is part of a write sequence for a layered image.
1891  */
1892 static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
1893 {
1894         dout("%s: obj %p\n", __func__, obj_request);
1895         obj_request_done_set(obj_request);
1896 }
1897
1898 static void rbd_osd_call_callback(struct rbd_obj_request *obj_request)
1899 {
1900         dout("%s: obj %p\n", __func__, obj_request);
1901
1902         if (obj_request_img_data_test(obj_request))
1903                 rbd_osd_copyup_callback(obj_request);
1904         else
1905                 obj_request_done_set(obj_request);
1906 }
1907
1908 static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
1909 {
1910         struct rbd_obj_request *obj_request = osd_req->r_priv;
1911         u16 opcode;
1912
1913         dout("%s: osd_req %p\n", __func__, osd_req);
1914         rbd_assert(osd_req == obj_request->osd_req);
1915         if (obj_request_img_data_test(obj_request)) {
1916                 rbd_assert(obj_request->img_request);
1917                 rbd_assert(obj_request->which != BAD_WHICH);
1918         } else {
1919                 rbd_assert(obj_request->which == BAD_WHICH);
1920         }
1921
1922         if (osd_req->r_result < 0)
1923                 obj_request->result = osd_req->r_result;
1924
1925         /*
1926          * We support a 64-bit length, but ultimately it has to be
1927          * passed to the block layer, which just supports a 32-bit
1928          * length field.
1929          */
1930         obj_request->xferred = osd_req->r_ops[0].outdata_len;
1931         rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1932
1933         opcode = osd_req->r_ops[0].op;
1934         switch (opcode) {
1935         case CEPH_OSD_OP_READ:
1936                 rbd_osd_read_callback(obj_request);
1937                 break;
1938         case CEPH_OSD_OP_SETALLOCHINT:
1939                 rbd_assert(osd_req->r_ops[1].op == CEPH_OSD_OP_WRITE ||
1940                            osd_req->r_ops[1].op == CEPH_OSD_OP_WRITEFULL);
1941                 /* fall through */
1942         case CEPH_OSD_OP_WRITE:
1943         case CEPH_OSD_OP_WRITEFULL:
1944                 rbd_osd_write_callback(obj_request);
1945                 break;
1946         case CEPH_OSD_OP_STAT:
1947                 rbd_osd_stat_callback(obj_request);
1948                 break;
1949         case CEPH_OSD_OP_DELETE:
1950         case CEPH_OSD_OP_TRUNCATE:
1951         case CEPH_OSD_OP_ZERO:
1952                 rbd_osd_discard_callback(obj_request);
1953                 break;
1954         case CEPH_OSD_OP_CALL:
1955                 rbd_osd_call_callback(obj_request);
1956                 break;
1957         default:
1958                 rbd_warn(NULL, "%s: unsupported op %hu",
1959                         obj_request->object_name, (unsigned short) opcode);
1960                 break;
1961         }
1962
1963         if (obj_request_done_test(obj_request))
1964                 rbd_obj_request_complete(obj_request);
1965 }
1966
1967 static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
1968 {
1969         struct ceph_osd_request *osd_req = obj_request->osd_req;
1970
1971         rbd_assert(obj_request_img_data_test(obj_request));
1972         osd_req->r_snapid = obj_request->img_request->snap_id;
1973 }
1974
1975 static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
1976 {
1977         struct ceph_osd_request *osd_req = obj_request->osd_req;
1978
1979         osd_req->r_mtime = CURRENT_TIME;
1980         osd_req->r_data_offset = obj_request->offset;
1981 }
1982
1983 /*
1984  * Create an osd request.  A read request has one osd op (read).
1985  * A write request has either one (watch) or two (hint+write) osd ops.
1986  * (All rbd data writes are prefixed with an allocation hint op, but
1987  * technically osd watch is a write request, hence this distinction.)
1988  */
1989 static struct ceph_osd_request *rbd_osd_req_create(
1990                                         struct rbd_device *rbd_dev,
1991                                         enum obj_operation_type op_type,
1992                                         unsigned int num_ops,
1993                                         struct rbd_obj_request *obj_request)
1994 {
1995         struct ceph_snap_context *snapc = NULL;
1996         struct ceph_osd_client *osdc;
1997         struct ceph_osd_request *osd_req;
1998
1999         if (obj_request_img_data_test(obj_request) &&
2000                 (op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_WRITE)) {
2001                 struct rbd_img_request *img_request = obj_request->img_request;
2002                 if (op_type == OBJ_OP_WRITE) {
2003                         rbd_assert(img_request_write_test(img_request));
2004                 } else {
2005                         rbd_assert(img_request_discard_test(img_request));
2006                 }
2007                 snapc = img_request->snapc;
2008         }
2009
2010         rbd_assert(num_ops == 1 || ((op_type == OBJ_OP_WRITE) && num_ops == 2));
2011
2012         /* Allocate and initialize the request, for the num_ops ops */
2013
2014         osdc = &rbd_dev->rbd_client->client->osdc;
2015         osd_req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false,
2016                                           GFP_NOIO);
2017         if (!osd_req)
2018                 goto fail;
2019
2020         if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
2021                 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
2022         else
2023                 osd_req->r_flags = CEPH_OSD_FLAG_READ;
2024
2025         osd_req->r_callback = rbd_osd_req_callback;
2026         osd_req->r_priv = obj_request;
2027
2028         osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2029         if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
2030                              obj_request->object_name))
2031                 goto fail;
2032
2033         if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
2034                 goto fail;
2035
2036         return osd_req;
2037
2038 fail:
2039         ceph_osdc_put_request(osd_req);
2040         return NULL;
2041 }
2042
2043 /*
2044  * Create a copyup osd request based on the information in the object
2045  * request supplied.  A copyup request has two or three osd ops, a
2046  * copyup method call, potentially a hint op, and a write or truncate
2047  * or zero op.
2048  */
2049 static struct ceph_osd_request *
2050 rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
2051 {
2052         struct rbd_img_request *img_request;
2053         struct ceph_snap_context *snapc;
2054         struct rbd_device *rbd_dev;
2055         struct ceph_osd_client *osdc;
2056         struct ceph_osd_request *osd_req;
2057         int num_osd_ops = 3;
2058
2059         rbd_assert(obj_request_img_data_test(obj_request));
2060         img_request = obj_request->img_request;
2061         rbd_assert(img_request);
2062         rbd_assert(img_request_write_test(img_request) ||
2063                         img_request_discard_test(img_request));
2064
2065         if (img_request_discard_test(img_request))
2066                 num_osd_ops = 2;
2067
2068         /* Allocate and initialize the request, for all the ops */
2069
2070         snapc = img_request->snapc;
2071         rbd_dev = img_request->rbd_dev;
2072         osdc = &rbd_dev->rbd_client->client->osdc;
2073         osd_req = ceph_osdc_alloc_request(osdc, snapc, num_osd_ops,
2074                                                 false, GFP_NOIO);
2075         if (!osd_req)
2076                 goto fail;
2077
2078         osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
2079         osd_req->r_callback = rbd_osd_req_callback;
2080         osd_req->r_priv = obj_request;
2081
2082         osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2083         if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
2084                              obj_request->object_name))
2085                 goto fail;
2086
2087         if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
2088                 goto fail;
2089
2090         return osd_req;
2091
2092 fail:
2093         ceph_osdc_put_request(osd_req);
2094         return NULL;
2095 }
2096
2097
2098 static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
2099 {
2100         ceph_osdc_put_request(osd_req);
2101 }
2102
2103 /* object_name is assumed to be a non-null pointer and NUL-terminated */
2104
2105 static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
2106                                                 u64 offset, u64 length,
2107                                                 enum obj_request_type type)
2108 {
2109         struct rbd_obj_request *obj_request;
2110         size_t size;
2111         char *name;
2112
2113         rbd_assert(obj_request_type_valid(type));
2114
2115         size = strlen(object_name) + 1;
2116         name = kmalloc(size, GFP_NOIO);
2117         if (!name)
2118                 return NULL;
2119
2120         obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
2121         if (!obj_request) {
2122                 kfree(name);
2123                 return NULL;
2124         }
2125
2126         obj_request->object_name = memcpy(name, object_name, size);
2127         obj_request->offset = offset;
2128         obj_request->length = length;
2129         obj_request->flags = 0;
2130         obj_request->which = BAD_WHICH;
2131         obj_request->type = type;
2132         INIT_LIST_HEAD(&obj_request->links);
2133         init_completion(&obj_request->completion);
2134         kref_init(&obj_request->kref);
2135
2136         dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
2137                 offset, length, (int)type, obj_request);
2138
2139         return obj_request;
2140 }
2141
2142 static void rbd_obj_request_destroy(struct kref *kref)
2143 {
2144         struct rbd_obj_request *obj_request;
2145
2146         obj_request = container_of(kref, struct rbd_obj_request, kref);
2147
2148         dout("%s: obj %p\n", __func__, obj_request);
2149
2150         rbd_assert(obj_request->img_request == NULL);
2151         rbd_assert(obj_request->which == BAD_WHICH);
2152
2153         if (obj_request->osd_req)
2154                 rbd_osd_req_destroy(obj_request->osd_req);
2155
2156         rbd_assert(obj_request_type_valid(obj_request->type));
2157         switch (obj_request->type) {
2158         case OBJ_REQUEST_NODATA:
2159                 break;          /* Nothing to do */
2160         case OBJ_REQUEST_BIO:
2161                 if (obj_request->bio_list)
2162                         bio_chain_put(obj_request->bio_list);
2163                 break;
2164         case OBJ_REQUEST_PAGES:
2165                 /* img_data requests don't own their page array */
2166                 if (obj_request->pages &&
2167                     !obj_request_img_data_test(obj_request))
2168                         ceph_release_page_vector(obj_request->pages,
2169                                                 obj_request->page_count);
2170                 break;
2171         }
2172
2173         kfree(obj_request->object_name);
2174         obj_request->object_name = NULL;
2175         kmem_cache_free(rbd_obj_request_cache, obj_request);
2176 }
2177
2178 /* It's OK to call this for a device with no parent */
2179
2180 static void rbd_spec_put(struct rbd_spec *spec);
2181 static void rbd_dev_unparent(struct rbd_device *rbd_dev)
2182 {
2183         rbd_dev_remove_parent(rbd_dev);
2184         rbd_spec_put(rbd_dev->parent_spec);
2185         rbd_dev->parent_spec = NULL;
2186         rbd_dev->parent_overlap = 0;
2187 }
2188
2189 /*
2190  * Parent image reference counting is used to determine when an
2191  * image's parent fields can be safely torn down--after there are no
2192  * more in-flight requests to the parent image.  When the last
2193  * reference is dropped, cleaning them up is safe.
2194  */
2195 static void rbd_dev_parent_put(struct rbd_device *rbd_dev)
2196 {
2197         int counter;
2198
2199         if (!rbd_dev->parent_spec)
2200                 return;
2201
2202         counter = atomic_dec_return_safe(&rbd_dev->parent_ref);
2203         if (counter > 0)
2204                 return;
2205
2206         /* Last reference; clean up parent data structures */
2207
2208         if (!counter)
2209                 rbd_dev_unparent(rbd_dev);
2210         else
2211                 rbd_warn(rbd_dev, "parent reference underflow");
2212 }
2213
2214 /*
2215  * If an image has a non-zero parent overlap, get a reference to its
2216  * parent.
2217  *
2218  * Returns true if the rbd device has a parent with a non-zero
2219  * overlap and a reference for it was successfully taken, or
2220  * false otherwise.
2221  */
2222 static bool rbd_dev_parent_get(struct rbd_device *rbd_dev)
2223 {
2224         int counter = 0;
2225
2226         if (!rbd_dev->parent_spec)
2227                 return false;
2228
2229         down_read(&rbd_dev->header_rwsem);
2230         if (rbd_dev->parent_overlap)
2231                 counter = atomic_inc_return_safe(&rbd_dev->parent_ref);
2232         up_read(&rbd_dev->header_rwsem);
2233
2234         if (counter < 0)
2235                 rbd_warn(rbd_dev, "parent reference overflow");
2236
2237         return counter > 0;
2238 }
2239
2240 /*
2241  * Caller is responsible for filling in the list of object requests
2242  * that comprises the image request, and the Linux request pointer
2243  * (if there is one).
2244  */
2245 static struct rbd_img_request *rbd_img_request_create(
2246                                         struct rbd_device *rbd_dev,
2247                                         u64 offset, u64 length,
2248                                         enum obj_operation_type op_type,
2249                                         struct ceph_snap_context *snapc)
2250 {
2251         struct rbd_img_request *img_request;
2252
2253         img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO);
2254         if (!img_request)
2255                 return NULL;
2256
2257         img_request->rq = NULL;
2258         img_request->rbd_dev = rbd_dev;
2259         img_request->offset = offset;
2260         img_request->length = length;
2261         img_request->flags = 0;
2262         if (op_type == OBJ_OP_DISCARD) {
2263                 img_request_discard_set(img_request);
2264                 img_request->snapc = snapc;
2265         } else if (op_type == OBJ_OP_WRITE) {
2266                 img_request_write_set(img_request);
2267                 img_request->snapc = snapc;
2268         } else {
2269                 img_request->snap_id = rbd_dev->spec->snap_id;
2270         }
2271         if (rbd_dev_parent_get(rbd_dev))
2272                 img_request_layered_set(img_request);
2273         spin_lock_init(&img_request->completion_lock);
2274         img_request->next_completion = 0;
2275         img_request->callback = NULL;
2276         img_request->result = 0;
2277         img_request->obj_request_count = 0;
2278         INIT_LIST_HEAD(&img_request->obj_requests);
2279         kref_init(&img_request->kref);
2280
2281         dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
2282                 obj_op_name(op_type), offset, length, img_request);
2283
2284         return img_request;
2285 }
2286
2287 static void rbd_img_request_destroy(struct kref *kref)
2288 {
2289         struct rbd_img_request *img_request;
2290         struct rbd_obj_request *obj_request;
2291         struct rbd_obj_request *next_obj_request;
2292
2293         img_request = container_of(kref, struct rbd_img_request, kref);
2294
2295         dout("%s: img %p\n", __func__, img_request);
2296
2297         for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2298                 rbd_img_obj_request_del(img_request, obj_request);
2299         rbd_assert(img_request->obj_request_count == 0);
2300
2301         if (img_request_layered_test(img_request)) {
2302                 img_request_layered_clear(img_request);
2303                 rbd_dev_parent_put(img_request->rbd_dev);
2304         }
2305
2306         if (img_request_write_test(img_request) ||
2307                 img_request_discard_test(img_request))
2308                 ceph_put_snap_context(img_request->snapc);
2309
2310         kmem_cache_free(rbd_img_request_cache, img_request);
2311 }
2312
2313 static struct rbd_img_request *rbd_parent_request_create(
2314                                         struct rbd_obj_request *obj_request,
2315                                         u64 img_offset, u64 length)
2316 {
2317         struct rbd_img_request *parent_request;
2318         struct rbd_device *rbd_dev;
2319
2320         rbd_assert(obj_request->img_request);
2321         rbd_dev = obj_request->img_request->rbd_dev;
2322
2323         parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
2324                                                 length, OBJ_OP_READ, NULL);
2325         if (!parent_request)
2326                 return NULL;
2327
2328         img_request_child_set(parent_request);
2329         rbd_obj_request_get(obj_request);
2330         parent_request->obj_request = obj_request;
2331
2332         return parent_request;
2333 }
2334
2335 static void rbd_parent_request_destroy(struct kref *kref)
2336 {
2337         struct rbd_img_request *parent_request;
2338         struct rbd_obj_request *orig_request;
2339
2340         parent_request = container_of(kref, struct rbd_img_request, kref);
2341         orig_request = parent_request->obj_request;
2342
2343         parent_request->obj_request = NULL;
2344         rbd_obj_request_put(orig_request);
2345         img_request_child_clear(parent_request);
2346
2347         rbd_img_request_destroy(kref);
2348 }
2349
2350 static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
2351 {
2352         struct rbd_img_request *img_request;
2353         unsigned int xferred;
2354         int result;
2355         bool more;
2356
2357         rbd_assert(obj_request_img_data_test(obj_request));
2358         img_request = obj_request->img_request;
2359
2360         rbd_assert(obj_request->xferred <= (u64)UINT_MAX);
2361         xferred = (unsigned int)obj_request->xferred;
2362         result = obj_request->result;
2363         if (result) {
2364                 struct rbd_device *rbd_dev = img_request->rbd_dev;
2365                 enum obj_operation_type op_type;
2366
2367                 if (img_request_discard_test(img_request))
2368                         op_type = OBJ_OP_DISCARD;
2369                 else if (img_request_write_test(img_request))
2370                         op_type = OBJ_OP_WRITE;
2371                 else
2372                         op_type = OBJ_OP_READ;
2373
2374                 rbd_warn(rbd_dev, "%s %llx at %llx (%llx)",
2375                         obj_op_name(op_type), obj_request->length,
2376                         obj_request->img_offset, obj_request->offset);
2377                 rbd_warn(rbd_dev, "  result %d xferred %x",
2378                         result, xferred);
2379                 if (!img_request->result)
2380                         img_request->result = result;
2381                 /*
2382                  * Need to end I/O on the entire obj_request worth of
2383                  * bytes in case of error.
2384                  */
2385                 xferred = obj_request->length;
2386         }
2387
2388         if (img_request_child_test(img_request)) {
2389                 rbd_assert(img_request->obj_request != NULL);
2390                 more = obj_request->which < img_request->obj_request_count - 1;
2391         } else {
2392                 rbd_assert(img_request->rq != NULL);
2393
2394                 more = blk_update_request(img_request->rq, result, xferred);
2395                 if (!more)
2396                         __blk_mq_end_request(img_request->rq, result);
2397         }
2398
2399         return more;
2400 }
2401
2402 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
2403 {
2404         struct rbd_img_request *img_request;
2405         u32 which = obj_request->which;
2406         bool more = true;
2407
2408         rbd_assert(obj_request_img_data_test(obj_request));
2409         img_request = obj_request->img_request;
2410
2411         dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
2412         rbd_assert(img_request != NULL);
2413         rbd_assert(img_request->obj_request_count > 0);
2414         rbd_assert(which != BAD_WHICH);
2415         rbd_assert(which < img_request->obj_request_count);
2416
2417         spin_lock_irq(&img_request->completion_lock);
2418         if (which != img_request->next_completion)
2419                 goto out;
2420
2421         for_each_obj_request_from(img_request, obj_request) {
2422                 rbd_assert(more);
2423                 rbd_assert(which < img_request->obj_request_count);
2424
2425                 if (!obj_request_done_test(obj_request))
2426                         break;
2427                 more = rbd_img_obj_end_request(obj_request);
2428                 which++;
2429         }
2430
2431         rbd_assert(more ^ (which == img_request->obj_request_count));
2432         img_request->next_completion = which;
2433 out:
2434         spin_unlock_irq(&img_request->completion_lock);
2435         rbd_img_request_put(img_request);
2436
2437         if (!more)
2438                 rbd_img_request_complete(img_request);
2439 }
2440
2441 /*
2442  * Add individual osd ops to the given ceph_osd_request and prepare
2443  * them for submission. num_ops is the current number of
2444  * osd operations already to the object request.
2445  */
2446 static void rbd_img_obj_request_fill(struct rbd_obj_request *obj_request,
2447                                 struct ceph_osd_request *osd_request,
2448                                 enum obj_operation_type op_type,
2449                                 unsigned int num_ops)
2450 {
2451         struct rbd_img_request *img_request = obj_request->img_request;
2452         struct rbd_device *rbd_dev = img_request->rbd_dev;
2453         u64 object_size = rbd_obj_bytes(&rbd_dev->header);
2454         u64 offset = obj_request->offset;
2455         u64 length = obj_request->length;
2456         u64 img_end;
2457         u16 opcode;
2458
2459         if (op_type == OBJ_OP_DISCARD) {
2460                 if (!offset && length == object_size &&
2461                     (!img_request_layered_test(img_request) ||
2462                      !obj_request_overlaps_parent(obj_request))) {
2463                         opcode = CEPH_OSD_OP_DELETE;
2464                 } else if ((offset + length == object_size)) {
2465                         opcode = CEPH_OSD_OP_TRUNCATE;
2466                 } else {
2467                         down_read(&rbd_dev->header_rwsem);
2468                         img_end = rbd_dev->header.image_size;
2469                         up_read(&rbd_dev->header_rwsem);
2470
2471                         if (obj_request->img_offset + length == img_end)
2472                                 opcode = CEPH_OSD_OP_TRUNCATE;
2473                         else
2474                                 opcode = CEPH_OSD_OP_ZERO;
2475                 }
2476         } else if (op_type == OBJ_OP_WRITE) {
2477                 if (!offset && length == object_size)
2478                         opcode = CEPH_OSD_OP_WRITEFULL;
2479                 else
2480                         opcode = CEPH_OSD_OP_WRITE;
2481                 osd_req_op_alloc_hint_init(osd_request, num_ops,
2482                                         object_size, object_size);
2483                 num_ops++;
2484         } else {
2485                 opcode = CEPH_OSD_OP_READ;
2486         }
2487
2488         if (opcode == CEPH_OSD_OP_DELETE)
2489                 osd_req_op_init(osd_request, num_ops, opcode, 0);
2490         else
2491                 osd_req_op_extent_init(osd_request, num_ops, opcode,
2492                                        offset, length, 0, 0);
2493
2494         if (obj_request->type == OBJ_REQUEST_BIO)
2495                 osd_req_op_extent_osd_data_bio(osd_request, num_ops,
2496                                         obj_request->bio_list, length);
2497         else if (obj_request->type == OBJ_REQUEST_PAGES)
2498                 osd_req_op_extent_osd_data_pages(osd_request, num_ops,
2499                                         obj_request->pages, length,
2500                                         offset & ~PAGE_MASK, false, false);
2501
2502         /* Discards are also writes */
2503         if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
2504                 rbd_osd_req_format_write(obj_request);
2505         else
2506                 rbd_osd_req_format_read(obj_request);
2507 }
2508
2509 /*
2510  * Split up an image request into one or more object requests, each
2511  * to a different object.  The "type" parameter indicates whether
2512  * "data_desc" is the pointer to the head of a list of bio
2513  * structures, or the base of a page array.  In either case this
2514  * function assumes data_desc describes memory sufficient to hold
2515  * all data described by the image request.
2516  */
2517 static int rbd_img_request_fill(struct rbd_img_request *img_request,
2518                                         enum obj_request_type type,
2519                                         void *data_desc)
2520 {
2521         struct rbd_device *rbd_dev = img_request->rbd_dev;
2522         struct rbd_obj_request *obj_request = NULL;
2523         struct rbd_obj_request *next_obj_request;
2524         struct bio *bio_list = NULL;
2525         unsigned int bio_offset = 0;
2526         struct page **pages = NULL;
2527         enum obj_operation_type op_type;
2528         u64 img_offset;
2529         u64 resid;
2530
2531         dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
2532                 (int)type, data_desc);
2533
2534         img_offset = img_request->offset;
2535         resid = img_request->length;
2536         rbd_assert(resid > 0);
2537         op_type = rbd_img_request_op_type(img_request);
2538
2539         if (type == OBJ_REQUEST_BIO) {
2540                 bio_list = data_desc;
2541                 rbd_assert(img_offset ==
2542                            bio_list->bi_iter.bi_sector << SECTOR_SHIFT);
2543         } else if (type == OBJ_REQUEST_PAGES) {
2544                 pages = data_desc;
2545         }
2546
2547         while (resid) {
2548                 struct ceph_osd_request *osd_req;
2549                 const char *object_name;
2550                 u64 offset;
2551                 u64 length;
2552
2553                 object_name = rbd_segment_name(rbd_dev, img_offset);
2554                 if (!object_name)
2555                         goto out_unwind;
2556                 offset = rbd_segment_offset(rbd_dev, img_offset);
2557                 length = rbd_segment_length(rbd_dev, img_offset, resid);
2558                 obj_request = rbd_obj_request_create(object_name,
2559                                                 offset, length, type);
2560                 /* object request has its own copy of the object name */
2561                 rbd_segment_name_free(object_name);
2562                 if (!obj_request)
2563                         goto out_unwind;
2564
2565                 /*
2566                  * set obj_request->img_request before creating the
2567                  * osd_request so that it gets the right snapc
2568                  */
2569                 rbd_img_obj_request_add(img_request, obj_request);
2570
2571                 if (type == OBJ_REQUEST_BIO) {
2572                         unsigned int clone_size;
2573
2574                         rbd_assert(length <= (u64)UINT_MAX);
2575                         clone_size = (unsigned int)length;
2576                         obj_request->bio_list =
2577                                         bio_chain_clone_range(&bio_list,
2578                                                                 &bio_offset,
2579                                                                 clone_size,
2580                                                                 GFP_NOIO);
2581                         if (!obj_request->bio_list)
2582                                 goto out_unwind;
2583                 } else if (type == OBJ_REQUEST_PAGES) {
2584                         unsigned int page_count;
2585
2586                         obj_request->pages = pages;
2587                         page_count = (u32)calc_pages_for(offset, length);
2588                         obj_request->page_count = page_count;
2589                         if ((offset + length) & ~PAGE_MASK)
2590                                 page_count--;   /* more on last page */
2591                         pages += page_count;
2592                 }
2593
2594                 osd_req = rbd_osd_req_create(rbd_dev, op_type,
2595                                         (op_type == OBJ_OP_WRITE) ? 2 : 1,
2596                                         obj_request);
2597                 if (!osd_req)
2598                         goto out_unwind;
2599
2600                 obj_request->osd_req = osd_req;
2601                 obj_request->callback = rbd_img_obj_callback;
2602                 obj_request->img_offset = img_offset;
2603
2604                 rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);
2605
2606                 img_offset += length;
2607                 resid -= length;
2608         }
2609
2610         return 0;
2611
2612 out_unwind:
2613         for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2614                 rbd_img_obj_request_del(img_request, obj_request);
2615
2616         return -ENOMEM;
2617 }
2618
2619 static void
2620 rbd_osd_copyup_callback(struct rbd_obj_request *obj_request)
2621 {
2622         struct rbd_img_request *img_request;
2623         struct rbd_device *rbd_dev;
2624         struct page **pages;
2625         u32 page_count;
2626
2627         dout("%s: obj %p\n", __func__, obj_request);
2628
2629         rbd_assert(obj_request->type == OBJ_REQUEST_BIO ||
2630                 obj_request->type == OBJ_REQUEST_NODATA);
2631         rbd_assert(obj_request_img_data_test(obj_request));
2632         img_request = obj_request->img_request;
2633         rbd_assert(img_request);
2634
2635         rbd_dev = img_request->rbd_dev;
2636         rbd_assert(rbd_dev);
2637
2638         pages = obj_request->copyup_pages;
2639         rbd_assert(pages != NULL);
2640         obj_request->copyup_pages = NULL;
2641         page_count = obj_request->copyup_page_count;
2642         rbd_assert(page_count);
2643         obj_request->copyup_page_count = 0;
2644         ceph_release_page_vector(pages, page_count);
2645
2646         /*
2647          * We want the transfer count to reflect the size of the
2648          * original write request.  There is no such thing as a
2649          * successful short write, so if the request was successful
2650          * we can just set it to the originally-requested length.
2651          */
2652         if (!obj_request->result)
2653                 obj_request->xferred = obj_request->length;
2654
2655         obj_request_done_set(obj_request);
2656 }
2657
2658 static void
2659 rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
2660 {
2661         struct rbd_obj_request *orig_request;
2662         struct ceph_osd_request *osd_req;
2663         struct rbd_device *rbd_dev;
2664         struct page **pages;
2665         enum obj_operation_type op_type;
2666         u32 page_count;
2667         int img_result;
2668         u64 parent_length;
2669
2670         rbd_assert(img_request_child_test(img_request));
2671
2672         /* First get what we need from the image request */
2673
2674         pages = img_request->copyup_pages;
2675         rbd_assert(pages != NULL);
2676         img_request->copyup_pages = NULL;
2677         page_count = img_request->copyup_page_count;
2678         rbd_assert(page_count);
2679         img_request->copyup_page_count = 0;
2680
2681         orig_request = img_request->obj_request;
2682         rbd_assert(orig_request != NULL);
2683         rbd_assert(obj_request_type_valid(orig_request->type));
2684         img_result = img_request->result;
2685         parent_length = img_request->length;
2686         rbd_assert(img_result || parent_length == img_request->xferred);
2687         rbd_img_request_put(img_request);
2688
2689         rbd_assert(orig_request->img_request);
2690         rbd_dev = orig_request->img_request->rbd_dev;
2691         rbd_assert(rbd_dev);
2692
2693         /*
2694          * If the overlap has become 0 (most likely because the
2695          * image has been flattened) we need to free the pages
2696          * and re-submit the original write request.
2697          */
2698         if (!rbd_dev->parent_overlap) {
2699                 ceph_release_page_vector(pages, page_count);
2700                 rbd_obj_request_submit(orig_request);
2701                 return;
2702         }
2703
2704         if (img_result)
2705                 goto out_err;
2706
2707         /*
2708          * The original osd request is of no use to use any more.
2709          * We need a new one that can hold the three ops in a copyup
2710          * request.  Allocate the new copyup osd request for the
2711          * original request, and release the old one.
2712          */
2713         img_result = -ENOMEM;
2714         osd_req = rbd_osd_req_create_copyup(orig_request);
2715         if (!osd_req)
2716                 goto out_err;
2717         rbd_osd_req_destroy(orig_request->osd_req);
2718         orig_request->osd_req = osd_req;
2719         orig_request->copyup_pages = pages;
2720         orig_request->copyup_page_count = page_count;
2721
2722         /* Initialize the copyup op */
2723
2724         osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2725         osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2726                                                 false, false);
2727
2728         /* Add the other op(s) */
2729
2730         op_type = rbd_img_request_op_type(orig_request->img_request);
2731         rbd_img_obj_request_fill(orig_request, osd_req, op_type, 1);
2732
2733         /* All set, send it off. */
2734
2735         rbd_obj_request_submit(orig_request);
2736         return;
2737
2738 out_err:
2739         ceph_release_page_vector(pages, page_count);
2740         rbd_obj_request_error(orig_request, img_result);
2741 }
2742
2743 /*
2744  * Read from the parent image the range of data that covers the
2745  * entire target of the given object request.  This is used for
2746  * satisfying a layered image write request when the target of an
2747  * object request from the image request does not exist.
2748  *
2749  * A page array big enough to hold the returned data is allocated
2750  * and supplied to rbd_img_request_fill() as the "data descriptor."
2751  * When the read completes, this page array will be transferred to
2752  * the original object request for the copyup operation.
2753  *
2754  * If an error occurs, it is recorded as the result of the original
2755  * object request in rbd_img_obj_exists_callback().
2756  */
2757 static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
2758 {
2759         struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2760         struct rbd_img_request *parent_request = NULL;
2761         u64 img_offset;
2762         u64 length;
2763         struct page **pages = NULL;
2764         u32 page_count;
2765         int result;
2766
2767         rbd_assert(rbd_dev->parent != NULL);
2768
2769         /*
2770          * Determine the byte range covered by the object in the
2771          * child image to which the original request was to be sent.
2772          */
2773         img_offset = obj_request->img_offset - obj_request->offset;
2774         length = (u64)1 << rbd_dev->header.obj_order;
2775
2776         /*
2777          * There is no defined parent data beyond the parent
2778          * overlap, so limit what we read at that boundary if
2779          * necessary.
2780          */
2781         if (img_offset + length > rbd_dev->parent_overlap) {
2782                 rbd_assert(img_offset < rbd_dev->parent_overlap);
2783                 length = rbd_dev->parent_overlap - img_offset;
2784         }
2785
2786         /*
2787          * Allocate a page array big enough to receive the data read
2788          * from the parent.
2789          */
2790         page_count = (u32)calc_pages_for(0, length);
2791         pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2792         if (IS_ERR(pages)) {
2793                 result = PTR_ERR(pages);
2794                 pages = NULL;
2795                 goto out_err;
2796         }
2797
2798         result = -ENOMEM;
2799         parent_request = rbd_parent_request_create(obj_request,
2800                                                 img_offset, length);
2801         if (!parent_request)
2802                 goto out_err;
2803
2804         result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
2805         if (result)
2806                 goto out_err;
2807
2808         parent_request->copyup_pages = pages;
2809         parent_request->copyup_page_count = page_count;
2810         parent_request->callback = rbd_img_obj_parent_read_full_callback;
2811
2812         result = rbd_img_request_submit(parent_request);
2813         if (!result)
2814                 return 0;
2815
2816         parent_request->copyup_pages = NULL;
2817         parent_request->copyup_page_count = 0;
2818         parent_request->obj_request = NULL;
2819         rbd_obj_request_put(obj_request);
2820 out_err:
2821         if (pages)
2822                 ceph_release_page_vector(pages, page_count);
2823         if (parent_request)
2824                 rbd_img_request_put(parent_request);
2825         return result;
2826 }
2827
2828 static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
2829 {
2830         struct rbd_obj_request *orig_request;
2831         struct rbd_device *rbd_dev;
2832         int result;
2833
2834         rbd_assert(!obj_request_img_data_test(obj_request));
2835
2836         /*
2837          * All we need from the object request is the original
2838          * request and the result of the STAT op.  Grab those, then
2839          * we're done with the request.
2840          */
2841         orig_request = obj_request->obj_request;
2842         obj_request->obj_request = NULL;
2843         rbd_obj_request_put(orig_request);
2844         rbd_assert(orig_request);
2845         rbd_assert(orig_request->img_request);
2846
2847         result = obj_request->result;
2848         obj_request->result = 0;
2849
2850         dout("%s: obj %p for obj %p result %d %llu/%llu\n", __func__,
2851                 obj_request, orig_request, result,
2852                 obj_request->xferred, obj_request->length);
2853         rbd_obj_request_put(obj_request);
2854
2855         /*
2856          * If the overlap has become 0 (most likely because the
2857          * image has been flattened) we need to re-submit the
2858          * original request.
2859          */
2860         rbd_dev = orig_request->img_request->rbd_dev;
2861         if (!rbd_dev->parent_overlap) {
2862                 rbd_obj_request_submit(orig_request);
2863                 return;
2864         }
2865
2866         /*
2867          * Our only purpose here is to determine whether the object
2868          * exists, and we don't want to treat the non-existence as
2869          * an error.  If something else comes back, transfer the
2870          * error to the original request and complete it now.
2871          */
2872         if (!result) {
2873                 obj_request_existence_set(orig_request, true);
2874         } else if (result == -ENOENT) {
2875                 obj_request_existence_set(orig_request, false);
2876         } else {
2877                 goto fail_orig_request;
2878         }
2879
2880         /*
2881          * Resubmit the original request now that we have recorded
2882          * whether the target object exists.
2883          */
2884         result = rbd_img_obj_request_submit(orig_request);
2885         if (result)
2886                 goto fail_orig_request;
2887
2888         return;
2889
2890 fail_orig_request:
2891         rbd_obj_request_error(orig_request, result);
2892 }
2893
2894 static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
2895 {
2896         struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2897         struct rbd_obj_request *stat_request;
2898         struct page **pages;
2899         u32 page_count;
2900         size_t size;
2901         int ret;
2902
2903         stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
2904                                               OBJ_REQUEST_PAGES);
2905         if (!stat_request)
2906                 return -ENOMEM;
2907
2908         stat_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
2909                                                    stat_request);
2910         if (!stat_request->osd_req) {
2911                 ret = -ENOMEM;
2912                 goto fail_stat_request;
2913         }
2914
2915         /*
2916          * The response data for a STAT call consists of:
2917          *     le64 length;
2918          *     struct {
2919          *         le32 tv_sec;
2920          *         le32 tv_nsec;
2921          *     } mtime;
2922          */
2923         size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
2924         page_count = (u32)calc_pages_for(0, size);
2925         pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2926         if (IS_ERR(pages)) {
2927                 ret = PTR_ERR(pages);
2928                 goto fail_stat_request;
2929         }
2930
2931         osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT, 0);
2932         osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
2933                                      false, false);
2934
2935         rbd_obj_request_get(obj_request);
2936         stat_request->obj_request = obj_request;
2937         stat_request->pages = pages;
2938         stat_request->page_count = page_count;
2939         stat_request->callback = rbd_img_obj_exists_callback;
2940
2941         rbd_obj_request_submit(stat_request);
2942         return 0;
2943
2944 fail_stat_request:
2945         rbd_obj_request_put(stat_request);
2946         return ret;
2947 }
2948
2949 static bool img_obj_request_simple(struct rbd_obj_request *obj_request)
2950 {
2951         struct rbd_img_request *img_request = obj_request->img_request;
2952         struct rbd_device *rbd_dev = img_request->rbd_dev;
2953
2954         /* Reads */
2955         if (!img_request_write_test(img_request) &&
2956             !img_request_discard_test(img_request))
2957                 return true;
2958
2959         /* Non-layered writes */
2960         if (!img_request_layered_test(img_request))
2961                 return true;
2962
2963         /*
2964          * Layered writes outside of the parent overlap range don't
2965          * share any data with the parent.
2966          */
2967         if (!obj_request_overlaps_parent(obj_request))
2968                 return true;
2969
2970         /*
2971          * Entire-object layered writes - we will overwrite whatever
2972          * parent data there is anyway.
2973          */
2974         if (!obj_request->offset &&
2975             obj_request->length == rbd_obj_bytes(&rbd_dev->header))
2976                 return true;
2977
2978         /*
2979          * If the object is known to already exist, its parent data has
2980          * already been copied.
2981          */
2982         if (obj_request_known_test(obj_request) &&
2983             obj_request_exists_test(obj_request))
2984                 return true;
2985
2986         return false;
2987 }
2988
2989 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
2990 {
2991         rbd_assert(obj_request_img_data_test(obj_request));
2992         rbd_assert(obj_request_type_valid(obj_request->type));
2993         rbd_assert(obj_request->img_request);
2994
2995         if (img_obj_request_simple(obj_request)) {
2996                 rbd_obj_request_submit(obj_request);
2997                 return 0;
2998         }
2999
3000         /*
3001          * It's a layered write.  The target object might exist but
3002          * we may not know that yet.  If we know it doesn't exist,
3003          * start by reading the data for the full target object from
3004          * the parent so we can use it for a copyup to the target.
3005          */
3006         if (obj_request_known_test(obj_request))
3007                 return rbd_img_obj_parent_read_full(obj_request);
3008
3009         /* We don't know whether the target exists.  Go find out. */
3010
3011         return rbd_img_obj_exists_submit(obj_request);
3012 }
3013
3014 static int rbd_img_request_submit(struct rbd_img_request *img_request)
3015 {
3016         struct rbd_obj_request *obj_request;
3017         struct rbd_obj_request *next_obj_request;
3018         int ret = 0;
3019
3020         dout("%s: img %p\n", __func__, img_request);
3021
3022         rbd_img_request_get(img_request);
3023         for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
3024                 ret = rbd_img_obj_request_submit(obj_request);
3025                 if (ret)
3026                         goto out_put_ireq;
3027         }
3028
3029 out_put_ireq:
3030         rbd_img_request_put(img_request);
3031         return ret;
3032 }
3033
3034 static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
3035 {
3036         struct rbd_obj_request *obj_request;
3037         struct rbd_device *rbd_dev;
3038         u64 obj_end;
3039         u64 img_xferred;
3040         int img_result;
3041
3042         rbd_assert(img_request_child_test(img_request));
3043
3044         /* First get what we need from the image request and release it */
3045
3046         obj_request = img_request->obj_request;
3047         img_xferred = img_request->xferred;
3048         img_result = img_request->result;
3049         rbd_img_request_put(img_request);
3050
3051         /*
3052          * If the overlap has become 0 (most likely because the
3053          * image has been flattened) we need to re-submit the
3054          * original request.
3055          */
3056         rbd_assert(obj_request);
3057         rbd_assert(obj_request->img_request);
3058         rbd_dev = obj_request->img_request->rbd_dev;
3059         if (!rbd_dev->parent_overlap) {
3060                 rbd_obj_request_submit(obj_request);
3061                 return;
3062         }
3063
3064         obj_request->result = img_result;
3065         if (obj_request->result)
3066                 goto out;
3067
3068         /*
3069          * We need to zero anything beyond the parent overlap
3070          * boundary.  Since rbd_img_obj_request_read_callback()
3071          * will zero anything beyond the end of a short read, an
3072          * easy way to do this is to pretend the data from the
3073          * parent came up short--ending at the overlap boundary.
3074          */
3075         rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length);
3076         obj_end = obj_request->img_offset + obj_request->length;
3077         if (obj_end > rbd_dev->parent_overlap) {
3078                 u64 xferred = 0;
3079
3080                 if (obj_request->img_offset < rbd_dev->parent_overlap)
3081                         xferred = rbd_dev->parent_overlap -
3082                                         obj_request->img_offset;
3083
3084                 obj_request->xferred = min(img_xferred, xferred);
3085         } else {
3086                 obj_request->xferred = img_xferred;
3087         }
3088 out:
3089         rbd_img_obj_request_read_callback(obj_request);
3090         rbd_obj_request_complete(obj_request);
3091 }
3092
3093 static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
3094 {
3095         struct rbd_img_request *img_request;
3096         int result;
3097
3098         rbd_assert(obj_request_img_data_test(obj_request));
3099         rbd_assert(obj_request->img_request != NULL);
3100         rbd_assert(obj_request->result == (s32) -ENOENT);
3101         rbd_assert(obj_request_type_valid(obj_request->type));
3102
3103         /* rbd_read_finish(obj_request, obj_request->length); */
3104         img_request = rbd_parent_request_create(obj_request,
3105                                                 obj_request->img_offset,
3106                                                 obj_request->length);
3107         result = -ENOMEM;
3108         if (!img_request)
3109                 goto out_err;
3110
3111         if (obj_request->type == OBJ_REQUEST_BIO)
3112                 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
3113                                                 obj_request->bio_list);
3114         else
3115                 result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES,
3116                                                 obj_request->pages);
3117         if (result)
3118                 goto out_err;
3119
3120         img_request->callback = rbd_img_parent_read_callback;
3121         result = rbd_img_request_submit(img_request);
3122         if (result)
3123                 goto out_err;
3124
3125         return;
3126 out_err:
3127         if (img_request)
3128                 rbd_img_request_put(img_request);
3129         obj_request->result = result;
3130         obj_request->xferred = 0;
3131         obj_request_done_set(obj_request);
3132 }
3133
3134 static const struct rbd_client_id rbd_empty_cid;
3135
3136 static bool rbd_cid_equal(const struct rbd_client_id *lhs,
3137                           const struct rbd_client_id *rhs)
3138 {
3139         return lhs->gid == rhs->gid && lhs->handle == rhs->handle;
3140 }
3141
3142 static struct rbd_client_id rbd_get_cid(struct rbd_device *rbd_dev)
3143 {
3144         struct rbd_client_id cid;
3145
3146         mutex_lock(&rbd_dev->watch_mutex);
3147         cid.gid = ceph_client_gid(rbd_dev->rbd_client->client);
3148         cid.handle = rbd_dev->watch_cookie;
3149         mutex_unlock(&rbd_dev->watch_mutex);
3150         return cid;
3151 }
3152
3153 /*
3154  * lock_rwsem must be held for write
3155  */
3156 static void rbd_set_owner_cid(struct rbd_device *rbd_dev,
3157                               const struct rbd_client_id *cid)
3158 {
3159         dout("%s rbd_dev %p %llu-%llu -> %llu-%llu\n", __func__, rbd_dev,
3160              rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle,
3161              cid->gid, cid->handle);
3162         rbd_dev->owner_cid = *cid; /* struct */
3163 }
3164
3165 static void format_lock_cookie(struct rbd_device *rbd_dev, char *buf)
3166 {
3167         mutex_lock(&rbd_dev->watch_mutex);
3168         sprintf(buf, "%s %llu", RBD_LOCK_COOKIE_PREFIX, rbd_dev->watch_cookie);
3169         mutex_unlock(&rbd_dev->watch_mutex);
3170 }
3171
3172 /*
3173  * lock_rwsem must be held for write
3174  */
3175 static int rbd_lock(struct rbd_device *rbd_dev)
3176 {
3177         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3178         struct rbd_client_id cid = rbd_get_cid(rbd_dev);
3179         char cookie[32];
3180         int ret;
3181
3182         WARN_ON(__rbd_is_lock_owner(rbd_dev));
3183
3184         format_lock_cookie(rbd_dev, cookie);
3185         ret = ceph_cls_lock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
3186                             RBD_LOCK_NAME, CEPH_CLS_LOCK_EXCLUSIVE, cookie,
3187                             RBD_LOCK_TAG, "", 0);
3188         if (ret)
3189                 return ret;
3190
3191         rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
3192         rbd_set_owner_cid(rbd_dev, &cid);
3193         queue_work(rbd_dev->task_wq, &rbd_dev->acquired_lock_work);
3194         return 0;
3195 }
3196
3197 /*
3198  * lock_rwsem must be held for write
3199  */
3200 static int rbd_unlock(struct rbd_device *rbd_dev)
3201 {
3202         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3203         char cookie[32];
3204         int ret;
3205
3206         WARN_ON(!__rbd_is_lock_owner(rbd_dev));
3207
3208         rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
3209
3210         format_lock_cookie(rbd_dev, cookie);
3211         ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
3212                               RBD_LOCK_NAME, cookie);
3213         if (ret && ret != -ENOENT) {
3214                 rbd_warn(rbd_dev, "cls_unlock failed: %d", ret);
3215                 return ret;
3216         }
3217
3218         rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
3219         queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
3220         return 0;
3221 }
3222
3223 static int __rbd_notify_op_lock(struct rbd_device *rbd_dev,
3224                                 enum rbd_notify_op notify_op,
3225                                 struct page ***preply_pages,
3226                                 size_t *preply_len)
3227 {
3228         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3229         struct rbd_client_id cid = rbd_get_cid(rbd_dev);
3230         int buf_size = 4 + 8 + 8 + CEPH_ENCODING_START_BLK_LEN;
3231         char buf[buf_size];
3232         void *p = buf;
3233
3234         dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
3235
3236         /* encode *LockPayload NotifyMessage (op + ClientId) */
3237         ceph_start_encoding(&p, 2, 1, buf_size - CEPH_ENCODING_START_BLK_LEN);
3238         ceph_encode_32(&p, notify_op);
3239         ceph_encode_64(&p, cid.gid);
3240         ceph_encode_64(&p, cid.handle);
3241
3242         return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
3243                                 &rbd_dev->header_oloc, buf, buf_size,
3244                                 RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
3245 }
3246
3247 static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
3248                                enum rbd_notify_op notify_op)
3249 {
3250         struct page **reply_pages;
3251         size_t reply_len;
3252
3253         __rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
3254         ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
3255 }
3256
3257 static void rbd_notify_acquired_lock(struct work_struct *work)
3258 {
3259         struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
3260                                                   acquired_lock_work);
3261
3262         rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
3263 }
3264
3265 static void rbd_notify_released_lock(struct work_struct *work)
3266 {
3267         struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
3268                                                   released_lock_work);
3269
3270         rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
3271 }
3272
3273 static int rbd_request_lock(struct rbd_device *rbd_dev)
3274 {
3275         struct page **reply_pages;
3276         size_t reply_len;
3277         bool lock_owner_responded = false;
3278         int ret;
3279
3280         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3281
3282         ret = __rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_REQUEST_LOCK,
3283                                    &reply_pages, &reply_len);
3284         if (ret && ret != -ETIMEDOUT) {
3285                 rbd_warn(rbd_dev, "failed to request lock: %d", ret);
3286                 goto out;
3287         }
3288
3289         if (reply_len > 0 && reply_len <= PAGE_SIZE) {
3290                 void *p = page_address(reply_pages[0]);
3291                 void *const end = p + reply_len;
3292                 u32 n;
3293
3294                 ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
3295                 while (n--) {
3296                         u8 struct_v;
3297                         u32 len;
3298
3299                         ceph_decode_need(&p, end, 8 + 8, e_inval);
3300                         p += 8 + 8; /* skip gid and cookie */
3301
3302                         ceph_decode_32_safe(&p, end, len, e_inval);
3303                         if (!len)
3304                                 continue;
3305
3306                         if (lock_owner_responded) {
3307                                 rbd_warn(rbd_dev,
3308                                          "duplicate lock owners detected");
3309                                 ret = -EIO;
3310                                 goto out;
3311                         }
3312
3313                         lock_owner_responded = true;
3314                         ret = ceph_start_decoding(&p, end, 1, "ResponseMessage",
3315                                                   &struct_v, &len);
3316                         if (ret) {
3317                                 rbd_warn(rbd_dev,
3318                                          "failed to decode ResponseMessage: %d",
3319                                          ret);
3320                                 goto e_inval;
3321                         }
3322
3323                         ret = ceph_decode_32(&p);
3324                 }
3325         }
3326
3327         if (!lock_owner_responded) {
3328                 rbd_warn(rbd_dev, "no lock owners detected");
3329                 ret = -ETIMEDOUT;
3330         }
3331
3332 out:
3333         ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
3334         return ret;
3335
3336 e_inval:
3337         ret = -EINVAL;
3338         goto out;
3339 }
3340
3341 static void wake_requests(struct rbd_device *rbd_dev, bool wake_all)
3342 {
3343         dout("%s rbd_dev %p wake_all %d\n", __func__, rbd_dev, wake_all);
3344
3345         cancel_delayed_work(&rbd_dev->lock_dwork);
3346         if (wake_all)
3347                 wake_up_all(&rbd_dev->lock_waitq);
3348         else
3349                 wake_up(&rbd_dev->lock_waitq);
3350 }
3351
3352 static int get_lock_owner_info(struct rbd_device *rbd_dev,
3353                                struct ceph_locker **lockers, u32 *num_lockers)
3354 {
3355         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3356         u8 lock_type;
3357         char *lock_tag;
3358         int ret;
3359
3360         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3361
3362         ret = ceph_cls_lock_info(osdc, &rbd_dev->header_oid,
3363                                  &rbd_dev->header_oloc, RBD_LOCK_NAME,
3364                                  &lock_type, &lock_tag, lockers, num_lockers);
3365         if (ret)
3366                 return ret;
3367
3368         if (*num_lockers == 0) {
3369                 dout("%s rbd_dev %p no lockers detected\n", __func__, rbd_dev);
3370                 goto out;
3371         }
3372
3373         if (strcmp(lock_tag, RBD_LOCK_TAG)) {
3374                 rbd_warn(rbd_dev, "locked by external mechanism, tag %s",
3375                          lock_tag);
3376                 ret = -EBUSY;
3377                 goto out;
3378         }
3379
3380         if (lock_type == CEPH_CLS_LOCK_SHARED) {
3381                 rbd_warn(rbd_dev, "shared lock type detected");
3382                 ret = -EBUSY;
3383                 goto out;
3384         }
3385
3386         if (strncmp((*lockers)[0].id.cookie, RBD_LOCK_COOKIE_PREFIX,
3387                     strlen(RBD_LOCK_COOKIE_PREFIX))) {
3388                 rbd_warn(rbd_dev, "locked by external mechanism, cookie %s",
3389                          (*lockers)[0].id.cookie);
3390                 ret = -EBUSY;
3391                 goto out;
3392         }
3393
3394 out:
3395         kfree(lock_tag);
3396         return ret;
3397 }
3398
3399 static int find_watcher(struct rbd_device *rbd_dev,
3400                         const struct ceph_locker *locker)
3401 {
3402         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3403         struct ceph_watch_item *watchers;
3404         u32 num_watchers;
3405         u64 cookie;
3406         int i;
3407         int ret;
3408
3409         ret = ceph_osdc_list_watchers(osdc, &rbd_dev->header_oid,
3410                                       &rbd_dev->header_oloc, &watchers,
3411                                       &num_watchers);
3412         if (ret)
3413                 return ret;
3414
3415         sscanf(locker->id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu", &cookie);
3416         for (i = 0; i < num_watchers; i++) {
3417                 if (!memcmp(&watchers[i].addr, &locker->info.addr,
3418                             sizeof(locker->info.addr)) &&
3419                     watchers[i].cookie == cookie) {
3420                         struct rbd_client_id cid = {
3421                                 .gid = le64_to_cpu(watchers[i].name.num),
3422                                 .handle = cookie,
3423                         };
3424
3425                         dout("%s rbd_dev %p found cid %llu-%llu\n", __func__,
3426                              rbd_dev, cid.gid, cid.handle);
3427                         rbd_set_owner_cid(rbd_dev, &cid);
3428                         ret = 1;
3429                         goto out;
3430                 }
3431         }
3432
3433         dout("%s rbd_dev %p no watchers\n", __func__, rbd_dev);
3434         ret = 0;
3435 out:
3436         kfree(watchers);
3437         return ret;
3438 }
3439
3440 /*
3441  * lock_rwsem must be held for write
3442  */
3443 static int rbd_try_lock(struct rbd_device *rbd_dev)
3444 {
3445         struct ceph_client *client = rbd_dev->rbd_client->client;
3446         struct ceph_locker *lockers;
3447         u32 num_lockers;
3448         int ret;
3449
3450         for (;;) {
3451                 ret = rbd_lock(rbd_dev);
3452                 if (ret != -EBUSY)
3453                         return ret;
3454
3455                 /* determine if the current lock holder is still alive */
3456                 ret = get_lock_owner_info(rbd_dev, &lockers, &num_lockers);
3457                 if (ret)
3458                         return ret;
3459
3460                 if (num_lockers == 0)
3461                         goto again;
3462
3463                 ret = find_watcher(rbd_dev, lockers);
3464                 if (ret) {
3465                         if (ret > 0)
3466                                 ret = 0; /* have to request lock */
3467                         goto out;
3468                 }
3469
3470                 rbd_warn(rbd_dev, "%s%llu seems dead, breaking lock",
3471                          ENTITY_NAME(lockers[0].id.name));
3472
3473                 ret = ceph_monc_blacklist_add(&client->monc,
3474                                               &lockers[0].info.addr);
3475                 if (ret) {
3476                         rbd_warn(rbd_dev, "blacklist of %s%llu failed: %d",
3477                                  ENTITY_NAME(lockers[0].id.name), ret);
3478                         goto out;
3479                 }
3480
3481                 ret = ceph_cls_break_lock(&client->osdc, &rbd_dev->header_oid,
3482                                           &rbd_dev->header_oloc, RBD_LOCK_NAME,
3483                                           lockers[0].id.cookie,
3484                                           &lockers[0].id.name);
3485                 if (ret && ret != -ENOENT)
3486                         goto out;
3487
3488 again:
3489                 ceph_free_lockers(lockers, num_lockers);
3490         }
3491
3492 out:
3493         ceph_free_lockers(lockers, num_lockers);
3494         return ret;
3495 }
3496
3497 /*
3498  * ret is set only if lock_state is RBD_LOCK_STATE_UNLOCKED
3499  */
3500 static enum rbd_lock_state rbd_try_acquire_lock(struct rbd_device *rbd_dev,
3501                                                 int *pret)
3502 {
3503         enum rbd_lock_state lock_state;
3504
3505         down_read(&rbd_dev->lock_rwsem);
3506         dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
3507              rbd_dev->lock_state);
3508         if (__rbd_is_lock_owner(rbd_dev)) {
3509                 lock_state = rbd_dev->lock_state;
3510                 up_read(&rbd_dev->lock_rwsem);
3511                 return lock_state;
3512         }
3513
3514         up_read(&rbd_dev->lock_rwsem);
3515         down_write(&rbd_dev->lock_rwsem);
3516         dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
3517              rbd_dev->lock_state);
3518         if (!__rbd_is_lock_owner(rbd_dev)) {
3519                 *pret = rbd_try_lock(rbd_dev);
3520                 if (*pret)
3521                         rbd_warn(rbd_dev, "failed to acquire lock: %d", *pret);
3522         }
3523
3524         lock_state = rbd_dev->lock_state;
3525         up_write(&rbd_dev->lock_rwsem);
3526         return lock_state;
3527 }
3528
3529 static void rbd_acquire_lock(struct work_struct *work)
3530 {
3531         struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
3532                                             struct rbd_device, lock_dwork);
3533         enum rbd_lock_state lock_state;
3534         int ret;
3535
3536         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3537 again:
3538         lock_state = rbd_try_acquire_lock(rbd_dev, &ret);
3539         if (lock_state != RBD_LOCK_STATE_UNLOCKED || ret == -EBLACKLISTED) {
3540                 if (lock_state == RBD_LOCK_STATE_LOCKED)
3541                         wake_requests(rbd_dev, true);
3542                 dout("%s rbd_dev %p lock_state %d ret %d - done\n", __func__,
3543                      rbd_dev, lock_state, ret);
3544                 return;
3545         }
3546
3547         ret = rbd_request_lock(rbd_dev);
3548         if (ret == -ETIMEDOUT) {
3549                 goto again; /* treat this as a dead client */
3550         } else if (ret < 0) {
3551                 rbd_warn(rbd_dev, "error requesting lock: %d", ret);
3552                 mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
3553                                  RBD_RETRY_DELAY);
3554         } else {
3555                 /*
3556                  * lock owner acked, but resend if we don't see them
3557                  * release the lock
3558                  */
3559                 dout("%s rbd_dev %p requeueing lock_dwork\n", __func__,
3560                      rbd_dev);
3561                 mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
3562                     msecs_to_jiffies(2 * RBD_NOTIFY_TIMEOUT * MSEC_PER_SEC));
3563         }
3564 }
3565
3566 /*
3567  * lock_rwsem must be held for write
3568  */
3569 static bool rbd_release_lock(struct rbd_device *rbd_dev)
3570 {
3571         dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
3572              rbd_dev->lock_state);
3573         if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
3574                 return false;
3575
3576         rbd_dev->lock_state = RBD_LOCK_STATE_RELEASING;
3577         downgrade_write(&rbd_dev->lock_rwsem);
3578         /*
3579          * Ensure that all in-flight IO is flushed.
3580          *
3581          * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
3582          * may be shared with other devices.
3583          */
3584         ceph_osdc_sync(&rbd_dev->rbd_client->client->osdc);
3585         up_read(&rbd_dev->lock_rwsem);
3586
3587         down_write(&rbd_dev->lock_rwsem);
3588         dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
3589              rbd_dev->lock_state);
3590         if (rbd_dev->lock_state != RBD_LOCK_STATE_RELEASING)
3591                 return false;
3592
3593         if (!rbd_unlock(rbd_dev))
3594                 /*
3595                  * Give others a chance to grab the lock - we would re-acquire
3596                  * almost immediately if we got new IO during ceph_osdc_sync()
3597                  * otherwise.  We need to ack our own notifications, so this
3598                  * lock_dwork will be requeued from rbd_wait_state_locked()
3599                  * after wake_requests() in rbd_handle_released_lock().
3600                  */
3601                 cancel_delayed_work(&rbd_dev->lock_dwork);
3602
3603         return true;
3604 }
3605
3606 static void rbd_release_lock_work(struct work_struct *work)
3607 {
3608         struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
3609                                                   unlock_work);
3610
3611         down_write(&rbd_dev->lock_rwsem);
3612         rbd_release_lock(rbd_dev);
3613         up_write(&rbd_dev->lock_rwsem);
3614 }
3615
3616 static void rbd_handle_acquired_lock(struct rbd_device *rbd_dev, u8 struct_v,
3617                                      void **p)
3618 {
3619         struct rbd_client_id cid = { 0 };
3620
3621         if (struct_v >= 2) {
3622                 cid.gid = ceph_decode_64(p);
3623                 cid.handle = ceph_decode_64(p);
3624         }
3625
3626         dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
3627              cid.handle);
3628         if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
3629                 down_write(&rbd_dev->lock_rwsem);
3630                 if (rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
3631                         /*
3632                          * we already know that the remote client is
3633                          * the owner
3634                          */
3635                         up_write(&rbd_dev->lock_rwsem);
3636                         return;
3637                 }
3638
3639                 rbd_set_owner_cid(rbd_dev, &cid);
3640                 downgrade_write(&rbd_dev->lock_rwsem);
3641         } else {
3642                 down_read(&rbd_dev->lock_rwsem);
3643         }
3644
3645         if (!__rbd_is_lock_owner(rbd_dev))
3646                 wake_requests(rbd_dev, false);
3647         up_read(&rbd_dev->lock_rwsem);
3648 }
3649
3650 static void rbd_handle_released_lock(struct rbd_device *rbd_dev, u8 struct_v,
3651                                      void **p)
3652 {
3653         struct rbd_client_id cid = { 0 };
3654
3655         if (struct_v >= 2) {
3656                 cid.gid = ceph_decode_64(p);
3657                 cid.handle = ceph_decode_64(p);
3658         }
3659
3660         dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
3661              cid.handle);
3662         if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
3663                 down_write(&rbd_dev->lock_rwsem);
3664                 if (!rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
3665                         dout("%s rbd_dev %p unexpected owner, cid %llu-%llu != owner_cid %llu-%llu\n",
3666                              __func__, rbd_dev, cid.gid, cid.handle,
3667                              rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle);
3668                         up_write(&rbd_dev->lock_rwsem);
3669                         return;
3670                 }
3671
3672                 rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
3673                 downgrade_write(&rbd_dev->lock_rwsem);
3674         } else {
3675                 down_read(&rbd_dev->lock_rwsem);
3676         }
3677
3678         if (!__rbd_is_lock_owner(rbd_dev))
3679                 wake_requests(rbd_dev, false);
3680         up_read(&rbd_dev->lock_rwsem);
3681 }
3682
3683 static bool rbd_handle_request_lock(struct rbd_device *rbd_dev, u8 struct_v,
3684                                     void **p)
3685 {
3686         struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
3687         struct rbd_client_id cid = { 0 };
3688         bool need_to_send;
3689
3690         if (struct_v >= 2) {
3691                 cid.gid = ceph_decode_64(p);
3692                 cid.handle = ceph_decode_64(p);
3693         }
3694
3695         dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
3696              cid.handle);
3697         if (rbd_cid_equal(&cid, &my_cid))
3698                 return false;
3699
3700         down_read(&rbd_dev->lock_rwsem);
3701         need_to_send = __rbd_is_lock_owner(rbd_dev);
3702         if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) {
3703                 if (!rbd_cid_equal(&rbd_dev->owner_cid, &rbd_empty_cid)) {
3704                         dout("%s rbd_dev %p queueing unlock_work\n", __func__,
3705                              rbd_dev);
3706                         queue_work(rbd_dev->task_wq, &rbd_dev->unlock_work);
3707                 }
3708         }
3709         up_read(&rbd_dev->lock_rwsem);
3710         return need_to_send;
3711 }
3712
3713 static void __rbd_acknowledge_notify(struct rbd_device *rbd_dev,
3714                                      u64 notify_id, u64 cookie, s32 *result)
3715 {
3716         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3717         int buf_size = 4 + CEPH_ENCODING_START_BLK_LEN;
3718         char buf[buf_size];
3719         int ret;
3720
3721         if (result) {
3722                 void *p = buf;
3723
3724                 /* encode ResponseMessage */
3725                 ceph_start_encoding(&p, 1, 1,
3726                                     buf_size - CEPH_ENCODING_START_BLK_LEN);
3727                 ceph_encode_32(&p, *result);
3728         } else {
3729                 buf_size = 0;
3730         }
3731
3732         ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
3733                                    &rbd_dev->header_oloc, notify_id, cookie,
3734                                    buf, buf_size);
3735         if (ret)
3736                 rbd_warn(rbd_dev, "acknowledge_notify failed: %d", ret);
3737 }
3738
3739 static void rbd_acknowledge_notify(struct rbd_device *rbd_dev, u64 notify_id,
3740                                    u64 cookie)
3741 {
3742         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3743         __rbd_acknowledge_notify(rbd_dev, notify_id, cookie, NULL);
3744 }
3745
3746 static void rbd_acknowledge_notify_result(struct rbd_device *rbd_dev,
3747                                           u64 notify_id, u64 cookie, s32 result)
3748 {
3749         dout("%s rbd_dev %p result %d\n", __func__, rbd_dev, result);
3750         __rbd_acknowledge_notify(rbd_dev, notify_id, cookie, &result);
3751 }
3752
3753 static void rbd_watch_cb(void *arg, u64 notify_id, u64 cookie,
3754                          u64 notifier_id, void *data, size_t data_len)
3755 {
3756         struct rbd_device *rbd_dev = arg;
3757         void *p = data;
3758         void *const end = p + data_len;
3759         u8 struct_v = 0;
3760         u32 len;
3761         u32 notify_op;
3762         int ret;
3763
3764         dout("%s rbd_dev %p cookie %llu notify_id %llu data_len %zu\n",
3765              __func__, rbd_dev, cookie, notify_id, data_len);
3766         if (data_len) {
3767                 ret = ceph_start_decoding(&p, end, 1, "NotifyMessage",
3768                                           &struct_v, &len);
3769                 if (ret) {
3770                         rbd_warn(rbd_dev, "failed to decode NotifyMessage: %d",
3771                                  ret);
3772                         return;
3773                 }
3774
3775                 notify_op = ceph_decode_32(&p);
3776         } else {
3777                 /* legacy notification for header updates */
3778                 notify_op = RBD_NOTIFY_OP_HEADER_UPDATE;
3779                 len = 0;
3780         }
3781
3782         dout("%s rbd_dev %p notify_op %u\n", __func__, rbd_dev, notify_op);
3783         switch (notify_op) {
3784         case RBD_NOTIFY_OP_ACQUIRED_LOCK:
3785                 rbd_handle_acquired_lock(rbd_dev, struct_v, &p);
3786                 rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
3787                 break;
3788         case RBD_NOTIFY_OP_RELEASED_LOCK:
3789                 rbd_handle_released_lock(rbd_dev, struct_v, &p);
3790                 rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
3791                 break;
3792         case RBD_NOTIFY_OP_REQUEST_LOCK:
3793                 if (rbd_handle_request_lock(rbd_dev, struct_v, &p))
3794                         /*
3795                          * send ResponseMessage(0) back so the client
3796                          * can detect a missing owner
3797                          */
3798                         rbd_acknowledge_notify_result(rbd_dev, notify_id,
3799                                                       cookie, 0);
3800                 else
3801                         rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
3802                 break;
3803         case RBD_NOTIFY_OP_HEADER_UPDATE:
3804                 ret = rbd_dev_refresh(rbd_dev);
3805                 if (ret)
3806                         rbd_warn(rbd_dev, "refresh failed: %d", ret);
3807
3808                 rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
3809                 break;
3810         default:
3811                 if (rbd_is_lock_owner(rbd_dev))
3812                         rbd_acknowledge_notify_result(rbd_dev, notify_id,
3813                                                       cookie, -EOPNOTSUPP);
3814                 else
3815                         rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
3816                 break;
3817         }
3818 }
3819
3820 static void __rbd_unregister_watch(struct rbd_device *rbd_dev);
3821
3822 static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3823 {
3824         struct rbd_device *rbd_dev = arg;
3825
3826         rbd_warn(rbd_dev, "encountered watch error: %d", err);
3827
3828         down_write(&rbd_dev->lock_rwsem);
3829         rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
3830         up_write(&rbd_dev->lock_rwsem);
3831
3832         mutex_lock(&rbd_dev->watch_mutex);
3833         if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED) {
3834                 __rbd_unregister_watch(rbd_dev);
3835                 rbd_dev->watch_state = RBD_WATCH_STATE_ERROR;
3836
3837                 queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3838         }
3839         mutex_unlock(&rbd_dev->watch_mutex);
3840 }
3841
3842 /*
3843  * watch_mutex must be locked
3844  */
3845 static int __rbd_register_watch(struct rbd_device *rbd_dev)
3846 {
3847         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3848         struct ceph_osd_linger_request *handle;
3849
3850         rbd_assert(!rbd_dev->watch_handle);
3851         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3852
3853         handle = ceph_osdc_watch(osdc, &rbd_dev->header_oid,
3854                                  &rbd_dev->header_oloc, rbd_watch_cb,
3855                                  rbd_watch_errcb, rbd_dev);
3856         if (IS_ERR(handle))
3857                 return PTR_ERR(handle);
3858
3859         rbd_dev->watch_handle = handle;
3860         return 0;
3861 }
3862
3863 /*
3864  * watch_mutex must be locked
3865  */
3866 static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3867 {
3868         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3869         int ret;
3870
3871         rbd_assert(rbd_dev->watch_handle);
3872         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3873
3874         ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
3875         if (ret)
3876                 rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3877
3878         rbd_dev->watch_handle = NULL;
3879 }
3880
3881 static int rbd_register_watch(struct rbd_device *rbd_dev)
3882 {
3883         int ret;
3884
3885         mutex_lock(&rbd_dev->watch_mutex);
3886         rbd_assert(rbd_dev->watch_state == RBD_WATCH_STATE_UNREGISTERED);
3887         ret = __rbd_register_watch(rbd_dev);
3888         if (ret)
3889                 goto out;
3890
3891         rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
3892         rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
3893
3894 out:
3895         mutex_unlock(&rbd_dev->watch_mutex);
3896         return ret;
3897 }
3898
3899 static void cancel_tasks_sync(struct rbd_device *rbd_dev)
3900 {
3901         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3902
3903         cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3904         cancel_work_sync(&rbd_dev->acquired_lock_work);
3905         cancel_work_sync(&rbd_dev->released_lock_work);
3906         cancel_delayed_work_sync(&rbd_dev->lock_dwork);
3907         cancel_work_sync(&rbd_dev->unlock_work);
3908 }
3909
3910 static void rbd_unregister_watch(struct rbd_device *rbd_dev)
3911 {
3912         WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3913         cancel_tasks_sync(rbd_dev);
3914
3915         mutex_lock(&rbd_dev->watch_mutex);
3916         if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED)
3917                 __rbd_unregister_watch(rbd_dev);
3918         rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
3919         mutex_unlock(&rbd_dev->watch_mutex);
3920
3921         ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
3922 }
3923
3924 static void rbd_reregister_watch(struct work_struct *work)
3925 {
3926         struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
3927                                             struct rbd_device, watch_dwork);
3928         bool was_lock_owner = false;
3929         bool need_to_wake = false;
3930         int ret;
3931
3932         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3933
3934         down_write(&rbd_dev->lock_rwsem);
3935         if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
3936                 was_lock_owner = rbd_release_lock(rbd_dev);
3937
3938         mutex_lock(&rbd_dev->watch_mutex);
3939         if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
3940                 mutex_unlock(&rbd_dev->watch_mutex);
3941                 goto out;
3942         }
3943
3944         ret = __rbd_register_watch(rbd_dev);
3945         if (ret) {
3946                 rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
3947                 if (ret == -EBLACKLISTED || ret == -ENOENT) {
3948                         set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
3949                         need_to_wake = true;
3950                 } else {
3951                         queue_delayed_work(rbd_dev->task_wq,
3952                                            &rbd_dev->watch_dwork,
3953                                            RBD_RETRY_DELAY);
3954                 }
3955                 mutex_unlock(&rbd_dev->watch_mutex);
3956                 goto out;
3957         }
3958
3959         need_to_wake = true;
3960         rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
3961         rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
3962         mutex_unlock(&rbd_dev->watch_mutex);
3963
3964         ret = rbd_dev_refresh(rbd_dev);
3965         if (ret)
3966                 rbd_warn(rbd_dev, "reregisteration refresh failed: %d", ret);
3967
3968         if (was_lock_owner) {
3969                 ret = rbd_try_lock(rbd_dev);
3970                 if (ret)
3971                         rbd_warn(rbd_dev, "reregisteration lock failed: %d",
3972                                  ret);
3973         }
3974
3975 out:
3976         up_write(&rbd_dev->lock_rwsem);
3977         if (need_to_wake)
3978                 wake_requests(rbd_dev, true);
3979 }
3980
3981 /*
3982  * Synchronous osd object method call.  Returns the number of bytes
3983  * returned in the outbound buffer, or a negative error code.
3984  */
3985 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
3986                              const char *object_name,
3987                              const char *class_name,
3988                              const char *method_name,
3989                              const void *outbound,
3990                              size_t outbound_size,
3991                              void *inbound,
3992                              size_t inbound_size)
3993 {
3994         struct rbd_obj_request *obj_request;
3995         struct page **pages;
3996         u32 page_count;
3997         int ret;
3998
3999         /*
4000          * Method calls are ultimately read operations.  The result
4001          * should placed into the inbound buffer provided.  They
4002          * also supply outbound data--parameters for the object
4003          * method.  Currently if this is present it will be a
4004          * snapshot id.
4005          */
4006         page_count = (u32)calc_pages_for(0, inbound_size);
4007         pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
4008         if (IS_ERR(pages))
4009                 return PTR_ERR(pages);
4010
4011         ret = -ENOMEM;
4012         obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
4013                                                         OBJ_REQUEST_PAGES);
4014         if (!obj_request)
4015                 goto out;
4016
4017         obj_request->pages = pages;
4018         obj_request->page_count = page_count;
4019
4020         obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
4021                                                   obj_request);
4022         if (!obj_request->osd_req)
4023                 goto out;
4024
4025         osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
4026                                         class_name, method_name);
4027         if (outbound_size) {
4028                 struct ceph_pagelist *pagelist;
4029
4030                 pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
4031                 if (!pagelist)
4032                         goto out;
4033
4034                 ceph_pagelist_init(pagelist);
4035                 ceph_pagelist_append(pagelist, outbound, outbound_size);
4036                 osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
4037                                                 pagelist);
4038         }
4039         osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
4040                                         obj_request->pages, inbound_size,
4041                                         0, false, false);
4042
4043         rbd_obj_request_submit(obj_request);
4044         ret = rbd_obj_request_wait(obj_request);
4045         if (ret)
4046                 goto out;
4047
4048         ret = obj_request->result;
4049         if (ret < 0)
4050                 goto out;
4051
4052         rbd_assert(obj_request->xferred < (u64)INT_MAX);
4053         ret = (int)obj_request->xferred;
4054         ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
4055 out:
4056         if (obj_request)
4057                 rbd_obj_request_put(obj_request);
4058         else
4059                 ceph_release_page_vector(pages, page_count);
4060
4061         return ret;
4062 }
4063
4064 /*
4065  * lock_rwsem must be held for read
4066  */
4067 static void rbd_wait_state_locked(struct rbd_device *rbd_dev)
4068 {
4069         DEFINE_WAIT(wait);
4070
4071         do {
4072                 /*
4073                  * Note the use of mod_delayed_work() in rbd_acquire_lock()
4074                  * and cancel_delayed_work() in wake_requests().
4075                  */
4076                 dout("%s rbd_dev %p queueing lock_dwork\n", __func__, rbd_dev);
4077                 queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
4078                 prepare_to_wait_exclusive(&rbd_dev->lock_waitq, &wait,
4079                                           TASK_UNINTERRUPTIBLE);
4080                 up_read(&rbd_dev->lock_rwsem);
4081                 schedule();
4082                 down_read(&rbd_dev->lock_rwsem);
4083         } while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
4084                  !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));
4085
4086         finish_wait(&rbd_dev->lock_waitq, &wait);
4087 }
4088
4089 static void rbd_queue_workfn(struct work_struct *work)
4090 {
4091         struct request *rq = blk_mq_rq_from_pdu(work);
4092         struct rbd_device *rbd_dev = rq->q->queuedata;
4093         struct rbd_img_request *img_request;
4094         struct ceph_snap_context *snapc = NULL;
4095         u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
4096         u64 length = blk_rq_bytes(rq);
4097         enum obj_operation_type op_type;
4098         u64 mapping_size;
4099         bool must_be_locked;
4100         int result;
4101
4102         switch (req_op(rq)) {
4103         case REQ_OP_DISCARD:
4104                 op_type = OBJ_OP_DISCARD;
4105                 break;
4106         case REQ_OP_WRITE:
4107                 op_type = OBJ_OP_WRITE;
4108                 break;
4109         case REQ_OP_READ:
4110                 op_type = OBJ_OP_READ;
4111                 break;
4112         default:
4113                 dout("%s: non-fs request type %d\n", __func__, req_op(rq));
4114                 result = -EIO;
4115                 goto err;
4116         }
4117
4118         /* Ignore/skip any zero-length requests */
4119
4120         if (!length) {
4121                 dout("%s: zero-length request\n", __func__);
4122                 result = 0;
4123                 goto err_rq;
4124         }
4125
4126         /* Only reads are allowed to a read-only device */
4127
4128         if (op_type != OBJ_OP_READ) {
4129                 if (rbd_dev->mapping.read_only) {
4130                         result = -EROFS;
4131                         goto err_rq;
4132                 }
4133                 rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
4134         }
4135
4136         /*
4137          * Quit early if the mapped snapshot no longer exists.  It's
4138          * still possible the snapshot will have disappeared by the
4139          * time our request arrives at the osd, but there's no sense in
4140          * sending it if we already know.
4141          */
4142         if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
4143                 dout("request for non-existent snapshot");
4144                 rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
4145                 result = -ENXIO;
4146                 goto err_rq;
4147         }
4148
4149         if (offset && length > U64_MAX - offset + 1) {
4150                 rbd_warn(rbd_dev, "bad request range (%llu~%llu)", offset,
4151                          length);
4152                 result = -EINVAL;
4153                 goto err_rq;    /* Shouldn't happen */
4154         }
4155
4156         blk_mq_start_request(rq);
4157
4158         down_read(&rbd_dev->header_rwsem);
4159         mapping_size = rbd_dev->mapping.size;
4160         if (op_type != OBJ_OP_READ) {
4161                 snapc = rbd_dev->header.snapc;
4162                 ceph_get_snap_context(snapc);
4163                 must_be_locked = rbd_is_lock_supported(rbd_dev);
4164         } else {
4165                 must_be_locked = rbd_dev->opts->lock_on_read &&
4166                                         rbd_is_lock_supported(rbd_dev);
4167         }
4168         up_read(&rbd_dev->header_rwsem);
4169
4170         if (offset + length > mapping_size) {
4171                 rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
4172                          length, mapping_size);
4173                 result = -EIO;
4174                 goto err_rq;
4175         }
4176
4177         if (must_be_locked) {
4178                 down_read(&rbd_dev->lock_rwsem);
4179                 if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
4180                     !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags))
4181                         rbd_wait_state_locked(rbd_dev);
4182
4183                 WARN_ON((rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) ^
4184                         !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));
4185                 if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
4186                         result = -EBLACKLISTED;
4187                         goto err_unlock;
4188                 }
4189         }
4190
4191         img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
4192                                              snapc);
4193         if (!img_request) {
4194                 result = -ENOMEM;
4195                 goto err_unlock;
4196         }
4197         img_request->rq = rq;
4198         snapc = NULL; /* img_request consumes a ref */
4199
4200         if (op_type == OBJ_OP_DISCARD)
4201                 result = rbd_img_request_fill(img_request, OBJ_REQUEST_NODATA,
4202                                               NULL);
4203         else
4204                 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
4205                                               rq->bio);
4206         if (result)
4207                 goto err_img_request;
4208
4209         result = rbd_img_request_submit(img_request);
4210         if (result)
4211                 goto err_img_request;
4212
4213         if (must_be_locked)
4214                 up_read(&rbd_dev->lock_rwsem);
4215         return;
4216
4217 err_img_request:
4218         rbd_img_request_put(img_request);
4219 err_unlock:
4220         if (must_be_locked)
4221                 up_read(&rbd_dev->lock_rwsem);
4222 err_rq:
4223         if (result)
4224                 rbd_warn(rbd_dev, "%s %llx at %llx result %d",
4225                          obj_op_name(op_type), length, offset, result);
4226         ceph_put_snap_context(snapc);
4227 err:
4228         blk_mq_end_request(rq, result);
4229 }
4230
4231 static int rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
4232                 const struct blk_mq_queue_data *bd)
4233 {
4234         struct request *rq = bd->rq;
4235         struct work_struct *work = blk_mq_rq_to_pdu(rq);
4236
4237         queue_work(rbd_wq, work);
4238         return BLK_MQ_RQ_QUEUE_OK;
4239 }
4240
4241 static void rbd_free_disk(struct rbd_device *rbd_dev)
4242 {
4243         struct gendisk *disk = rbd_dev->disk;
4244
4245         if (!disk)
4246                 return;
4247
4248         rbd_dev->disk = NULL;
4249         if (disk->flags & GENHD_FL_UP) {
4250                 del_gendisk(disk);
4251                 if (disk->queue)
4252                         blk_cleanup_queue(disk->queue);
4253                 blk_mq_free_tag_set(&rbd_dev->tag_set);
4254         }
4255         put_disk(disk);
4256 }
4257
4258 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
4259                                 const char *object_name,
4260                                 u64 offset, u64 length, void *buf)
4261
4262 {
4263         struct rbd_obj_request *obj_request;
4264         struct page **pages = NULL;
4265         u32 page_count;
4266         size_t size;
4267         int ret;
4268
4269         page_count = (u32) calc_pages_for(offset, length);
4270         pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
4271         if (IS_ERR(pages))
4272                 return PTR_ERR(pages);
4273
4274         ret = -ENOMEM;
4275         obj_request = rbd_obj_request_create(object_name, offset, length,
4276                                                         OBJ_REQUEST_PAGES);
4277         if (!obj_request)
4278                 goto out;
4279
4280         obj_request->pages = pages;
4281         obj_request->page_count = page_count;
4282
4283         obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
4284                                                   obj_request);
4285         if (!obj_request->osd_req)
4286                 goto out;
4287
4288         osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
4289                                         offset, length, 0, 0);
4290         osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
4291                                         obj_request->pages,
4292                                         obj_request->length,
4293                                         obj_request->offset & ~PAGE_MASK,
4294                                         false, false);
4295
4296         rbd_obj_request_submit(obj_request);
4297         ret = rbd_obj_request_wait(obj_request);
4298         if (ret)
4299                 goto out;
4300
4301         ret = obj_request->result;
4302         if (ret < 0)
4303                 goto out;
4304
4305         rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
4306         size = (size_t) obj_request->xferred;
4307         ceph_copy_from_page_vector(pages, buf, 0, size);
4308         rbd_assert(size <= (size_t)INT_MAX);
4309         ret = (int)size;
4310 out:
4311         if (obj_request)
4312                 rbd_obj_request_put(obj_request);
4313         else
4314                 ceph_release_page_vector(pages, page_count);
4315
4316         return ret;
4317 }
4318
4319 /*
4320  * Read the complete header for the given rbd device.  On successful
4321  * return, the rbd_dev->header field will contain up-to-date
4322  * information about the image.
4323  */
4324 static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
4325 {
4326         struct rbd_image_header_ondisk *ondisk = NULL;
4327         u32 snap_count = 0;
4328         u64 names_size = 0;
4329         u32 want_count;
4330         int ret;
4331
4332         /*
4333          * The complete header will include an array of its 64-bit
4334          * snapshot ids, followed by the names of those snapshots as
4335          * a contiguous block of NUL-terminated strings.  Note that
4336          * the number of snapshots could change by the time we read
4337          * it in, in which case we re-read it.
4338          */
4339         do {
4340                 size_t size;
4341
4342                 kfree(ondisk);
4343
4344                 size = sizeof (*ondisk);
4345                 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
4346                 size += names_size;
4347                 ondisk = kmalloc(size, GFP_KERNEL);
4348                 if (!ondisk)
4349                         return -ENOMEM;
4350
4351                 ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_oid.name,
4352                                        0, size, ondisk);
4353                 if (ret < 0)
4354                         goto out;
4355                 if ((size_t)ret < size) {
4356                         ret = -ENXIO;
4357                         rbd_warn(rbd_dev, "short header read (want %zd got %d)",
4358                                 size, ret);
4359                         goto out;
4360                 }
4361                 if (!rbd_dev_ondisk_valid(ondisk)) {
4362                         ret = -ENXIO;
4363                         rbd_warn(rbd_dev, "invalid header");
4364                         goto out;
4365                 }
4366
4367                 names_size = le64_to_cpu(ondisk->snap_names_len);
4368                 want_count = snap_count;
4369                 snap_count = le32_to_cpu(ondisk->snap_count);
4370         } while (snap_count != want_count);
4371
4372         ret = rbd_header_from_disk(rbd_dev, ondisk);
4373 out:
4374         kfree(ondisk);
4375
4376         return ret;
4377 }
4378
4379 /*
4380  * Clear the rbd device's EXISTS flag if the snapshot it's mapped to
4381  * has disappeared from the (just updated) snapshot context.
4382  */
4383 static void rbd_exists_validate(struct rbd_device *rbd_dev)
4384 {
4385         u64 snap_id;
4386
4387         if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags))
4388                 return;
4389
4390         snap_id = rbd_dev->spec->snap_id;
4391         if (snap_id == CEPH_NOSNAP)
4392                 return;
4393
4394         if (rbd_dev_snap_index(rbd_dev, snap_id) == BAD_SNAP_INDEX)
4395                 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4396 }
4397
4398 static void rbd_dev_update_size(struct rbd_device *rbd_dev)
4399 {
4400         sector_t size;
4401
4402         /*
4403          * If EXISTS is not set, rbd_dev->disk may be NULL, so don't
4404          * try to update its size.  If REMOVING is set, updating size
4405          * is just useless work since the device can't be opened.
4406          */
4407         if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
4408             !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
4409                 size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
4410                 dout("setting size to %llu sectors", (unsigned long long)size);
4411                 set_capacity(rbd_dev->disk, size);
4412                 revalidate_disk(rbd_dev->disk);
4413         }
4414 }
4415
4416 static int rbd_dev_refresh(struct rbd_device *rbd_dev)
4417 {
4418         u64 mapping_size;
4419         int ret;
4420
4421         down_write(&rbd_dev->header_rwsem);
4422         mapping_size = rbd_dev->mapping.size;
4423
4424         ret = rbd_dev_header_info(rbd_dev);
4425         if (ret)
4426                 goto out;
4427
4428         /*
4429          * If there is a parent, see if it has disappeared due to the
4430          * mapped image getting flattened.
4431          */
4432         if (rbd_dev->parent) {
4433                 ret = rbd_dev_v2_parent_info(rbd_dev);
4434                 if (ret)
4435                         goto out;
4436         }
4437
4438         if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
4439                 rbd_dev->mapping.size = rbd_dev->header.image_size;
4440         } else {
4441                 /* validate mapped snapshot's EXISTS flag */
4442                 rbd_exists_validate(rbd_dev);
4443         }
4444
4445 out:
4446         up_write(&rbd_dev->header_rwsem);
4447         if (!ret && mapping_size != rbd_dev->mapping.size)
4448                 rbd_dev_update_size(rbd_dev);
4449
4450         return ret;
4451 }
4452
4453 static int rbd_init_request(void *data, struct request *rq,
4454                 unsigned int hctx_idx, unsigned int request_idx,
4455                 unsigned int numa_node)
4456 {
4457         struct work_struct *work = blk_mq_rq_to_pdu(rq);
4458
4459         INIT_WORK(work, rbd_queue_workfn);
4460         return 0;
4461 }
4462
4463 static struct blk_mq_ops rbd_mq_ops = {
4464         .queue_rq       = rbd_queue_rq,
4465         .init_request   = rbd_init_request,
4466 };
4467
4468 static int rbd_init_disk(struct rbd_device *rbd_dev)
4469 {
4470         struct gendisk *disk;
4471         struct request_queue *q;
4472         u64 segment_size;
4473         int err;
4474
4475         /* create gendisk info */
4476         disk = alloc_disk(single_major ?
4477                           (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
4478                           RBD_MINORS_PER_MAJOR);
4479         if (!disk)
4480                 return -ENOMEM;
4481
4482         snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
4483                  rbd_dev->dev_id);
4484         disk->major = rbd_dev->major;
4485         disk->first_minor = rbd_dev->minor;
4486         if (single_major)
4487                 disk->flags |= GENHD_FL_EXT_DEVT;
4488         disk->fops = &rbd_bd_ops;
4489         disk->private_data = rbd_dev;
4490
4491         memset(&rbd_dev->tag_set, 0, sizeof(rbd_dev->tag_set));
4492         rbd_dev->tag_set.ops = &rbd_mq_ops;
4493         rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
4494         rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
4495         rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
4496         rbd_dev->tag_set.nr_hw_queues = 1;
4497         rbd_dev->tag_set.cmd_size = sizeof(struct work_struct);
4498
4499         err = blk_mq_alloc_tag_set(&rbd_dev->tag_set);
4500         if (err)
4501                 goto out_disk;
4502
4503         q = blk_mq_init_queue(&rbd_dev->tag_set);
4504         if (IS_ERR(q)) {
4505                 err = PTR_ERR(q);
4506                 goto out_tag_set;
4507         }
4508
4509         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
4510         /* QUEUE_FLAG_ADD_RANDOM is off by default for blk-mq */
4511
4512         /* set io sizes to object size */
4513         segment_size = rbd_obj_bytes(&rbd_dev->header);
4514         blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
4515         q->limits.max_sectors = queue_max_hw_sectors(q);
4516         blk_queue_max_segments(q, segment_size / SECTOR_SIZE);
4517         blk_queue_max_segment_size(q, segment_size);
4518         blk_queue_io_min(q, segment_size);
4519         blk_queue_io_opt(q, segment_size);
4520
4521         /* enable the discard support */
4522         queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
4523         q->limits.discard_granularity = segment_size;
4524         q->limits.discard_alignment = segment_size;
4525         blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
4526         q->limits.discard_zeroes_data = 1;
4527
4528         if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
4529                 q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
4530
4531         disk->queue = q;
4532
4533         q->queuedata = rbd_dev;
4534
4535         rbd_dev->disk = disk;
4536
4537         return 0;
4538 out_tag_set:
4539         blk_mq_free_tag_set(&rbd_dev->tag_set);
4540 out_disk:
4541         put_disk(disk);
4542         return err;
4543 }
4544
4545 /*
4546   sysfs
4547 */
4548
4549 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
4550 {
4551         return container_of(dev, struct rbd_device, dev);
4552 }
4553
4554 static ssize_t rbd_size_show(struct device *dev,
4555                              struct device_attribute *attr, char *buf)
4556 {
4557         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4558
4559         return sprintf(buf, "%llu\n",
4560                 (unsigned long long)rbd_dev->mapping.size);
4561 }
4562
4563 /*
4564  * Note this shows the features for whatever's mapped, which is not
4565  * necessarily the base image.
4566  */
4567 static ssize_t rbd_features_show(struct device *dev,
4568                              struct device_attribute *attr, char *buf)
4569 {
4570         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4571
4572         return sprintf(buf, "0x%016llx\n",
4573                         (unsigned long long)rbd_dev->mapping.features);
4574 }
4575
4576 static ssize_t rbd_major_show(struct device *dev,
4577                               struct device_attribute *attr, char *buf)
4578 {
4579         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4580
4581         if (rbd_dev->major)
4582                 return sprintf(buf, "%d\n", rbd_dev->major);
4583
4584         return sprintf(buf, "(none)\n");
4585 }
4586
4587 static ssize_t rbd_minor_show(struct device *dev,
4588                               struct device_attribute *attr, char *buf)
4589 {
4590         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4591
4592         return sprintf(buf, "%d\n", rbd_dev->minor);
4593 }
4594
4595 static ssize_t rbd_client_addr_show(struct device *dev,
4596                                     struct device_attribute *attr, char *buf)
4597 {
4598         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4599         struct ceph_entity_addr *client_addr =
4600             ceph_client_addr(rbd_dev->rbd_client->client);
4601
4602         return sprintf(buf, "%pISpc/%u\n", &client_addr->in_addr,
4603                        le32_to_cpu(client_addr->nonce));
4604 }
4605
4606 static ssize_t rbd_client_id_show(struct device *dev,
4607                                   struct device_attribute *attr, char *buf)
4608 {
4609         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4610
4611         return sprintf(buf, "client%lld\n",
4612                        ceph_client_gid(rbd_dev->rbd_client->client));
4613 }
4614
4615 static ssize_t rbd_cluster_fsid_show(struct device *dev,
4616                                      struct device_attribute *attr, char *buf)
4617 {
4618         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4619
4620         return sprintf(buf, "%pU\n", &rbd_dev->rbd_client->client->fsid);
4621 }
4622
4623 static ssize_t rbd_config_info_show(struct device *dev,
4624                                     struct device_attribute *attr, char *buf)
4625 {
4626         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4627
4628         return sprintf(buf, "%s\n", rbd_dev->config_info);
4629 }
4630
4631 static ssize_t rbd_pool_show(struct device *dev,
4632                              struct device_attribute *attr, char *buf)
4633 {
4634         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4635
4636         return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
4637 }
4638
4639 static ssize_t rbd_pool_id_show(struct device *dev,
4640                              struct device_attribute *attr, char *buf)
4641 {
4642         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4643
4644         return sprintf(buf, "%llu\n",
4645                         (unsigned long long) rbd_dev->spec->pool_id);
4646 }
4647
4648 static ssize_t rbd_name_show(struct device *dev,
4649                              struct device_attribute *attr, char *buf)
4650 {
4651         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4652
4653         if (rbd_dev->spec->image_name)
4654                 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
4655
4656         return sprintf(buf, "(unknown)\n");
4657 }
4658
4659 static ssize_t rbd_image_id_show(struct device *dev,
4660                              struct device_attribute *attr, char *buf)
4661 {
4662         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4663
4664         return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
4665 }
4666
4667 /*
4668  * Shows the name of the currently-mapped snapshot (or
4669  * RBD_SNAP_HEAD_NAME for the base image).
4670  */
4671 static ssize_t rbd_snap_show(struct device *dev,
4672                              struct device_attribute *attr,
4673                              char *buf)
4674 {
4675         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4676
4677         return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
4678 }
4679
4680 static ssize_t rbd_snap_id_show(struct device *dev,
4681                                 struct device_attribute *attr, char *buf)
4682 {
4683         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4684
4685         return sprintf(buf, "%llu\n", rbd_dev->spec->snap_id);
4686 }
4687
4688 /*
4689  * For a v2 image, shows the chain of parent images, separated by empty
4690  * lines.  For v1 images or if there is no parent, shows "(no parent
4691  * image)".
4692  */
4693 static ssize_t rbd_parent_show(struct device *dev,
4694                                struct device_attribute *attr,
4695                                char *buf)
4696 {
4697         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4698         ssize_t count = 0;
4699
4700         if (!rbd_dev->parent)
4701                 return sprintf(buf, "(no parent image)\n");
4702
4703         for ( ; rbd_dev->parent; rbd_dev = rbd_dev->parent) {
4704                 struct rbd_spec *spec = rbd_dev->parent_spec;
4705
4706                 count += sprintf(&buf[count], "%s"
4707                             "pool_id %llu\npool_name %s\n"
4708                             "image_id %s\nimage_name %s\n"
4709                             "snap_id %llu\nsnap_name %s\n"
4710                             "overlap %llu\n",
4711                             !count ? "" : "\n", /* first? */
4712                             spec->pool_id, spec->pool_name,
4713                             spec->image_id, spec->image_name ?: "(unknown)",
4714                             spec->snap_id, spec->snap_name,
4715                             rbd_dev->parent_overlap);
4716         }
4717
4718         return count;
4719 }
4720
4721 static ssize_t rbd_image_refresh(struct device *dev,
4722                                  struct device_attribute *attr,
4723                                  const char *buf,
4724                                  size_t size)
4725 {
4726         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4727         int ret;
4728
4729         ret = rbd_dev_refresh(rbd_dev);
4730         if (ret)
4731                 return ret;
4732
4733         return size;
4734 }
4735
4736 static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
4737 static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4738 static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4739 static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4740 static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4741 static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4742 static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4743 static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4744 static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4745 static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4746 static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
4747 static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4748 static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
4749 static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4750 static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4751 static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4752
4753 static struct attribute *rbd_attrs[] = {
4754         &dev_attr_size.attr,
4755         &dev_attr_features.attr,
4756         &dev_attr_major.attr,
4757         &dev_attr_minor.attr,
4758         &dev_attr_client_addr.attr,
4759         &dev_attr_client_id.attr,
4760         &dev_attr_cluster_fsid.attr,
4761         &dev_attr_config_info.attr,
4762         &dev_attr_pool.attr,
4763         &dev_attr_pool_id.attr,
4764         &dev_attr_name.attr,
4765         &dev_attr_image_id.attr,
4766         &dev_attr_current_snap.attr,
4767         &dev_attr_snap_id.attr,
4768         &dev_attr_parent.attr,
4769         &dev_attr_refresh.attr,
4770         NULL
4771 };
4772
4773 static struct attribute_group rbd_attr_group = {
4774         .attrs = rbd_attrs,
4775 };
4776
4777 static const struct attribute_group *rbd_attr_groups[] = {
4778         &rbd_attr_group,
4779         NULL
4780 };
4781
4782 static void rbd_dev_release(struct device *dev);
4783
4784 static struct device_type rbd_device_type = {
4785         .name           = "rbd",
4786         .groups         = rbd_attr_groups,
4787         .release        = rbd_dev_release,
4788 };
4789
4790 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
4791 {
4792         kref_get(&spec->kref);
4793
4794         return spec;
4795 }
4796
4797 static void rbd_spec_free(struct kref *kref);
4798 static void rbd_spec_put(struct rbd_spec *spec)
4799 {
4800         if (spec)
4801                 kref_put(&spec->kref, rbd_spec_free);
4802 }
4803
4804 static struct rbd_spec *rbd_spec_alloc(void)
4805 {
4806         struct rbd_spec *spec;
4807
4808         spec = kzalloc(sizeof (*spec), GFP_KERNEL);
4809         if (!spec)
4810                 return NULL;
4811
4812         spec->pool_id = CEPH_NOPOOL;
4813         spec->snap_id = CEPH_NOSNAP;
4814         kref_init(&spec->kref);
4815
4816         return spec;
4817 }
4818
4819 static void rbd_spec_free(struct kref *kref)
4820 {
4821         struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
4822
4823         kfree(spec->pool_name);
4824         kfree(spec->image_id);
4825         kfree(spec->image_name);
4826         kfree(spec->snap_name);
4827         kfree(spec);
4828 }
4829
4830 static void rbd_dev_free(struct rbd_device *rbd_dev)
4831 {
4832         WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4833         WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4834
4835         ceph_oid_destroy(&rbd_dev->header_oid);
4836         ceph_oloc_destroy(&rbd_dev->header_oloc);
4837         kfree(rbd_dev->config_info);
4838
4839         rbd_put_client(rbd_dev->rbd_client);
4840         rbd_spec_put(rbd_dev->spec);
4841         kfree(rbd_dev->opts);
4842         kfree(rbd_dev);
4843 }
4844
4845 static void rbd_dev_release(struct device *dev)
4846 {
4847         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4848         bool need_put = !!rbd_dev->opts;
4849
4850         if (need_put) {
4851                 destroy_workqueue(rbd_dev->task_wq);
4852                 ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
4853         }
4854
4855         rbd_dev_free(rbd_dev);
4856
4857         /*
4858          * This is racy, but way better than putting module outside of
4859          * the release callback.  The race window is pretty small, so
4860          * doing something similar to dm (dm-builtin.c) is overkill.
4861          */
4862         if (need_put)
4863                 module_put(THIS_MODULE);
4864 }
4865
4866 static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
4867                                            struct rbd_spec *spec)
4868 {
4869         struct rbd_device *rbd_dev;
4870
4871         rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4872         if (!rbd_dev)
4873                 return NULL;
4874
4875         spin_lock_init(&rbd_dev->lock);
4876         INIT_LIST_HEAD(&rbd_dev->node);
4877         init_rwsem(&rbd_dev->header_rwsem);
4878
4879         ceph_oid_init(&rbd_dev->header_oid);
4880         ceph_oloc_init(&rbd_dev->header_oloc);
4881
4882         mutex_init(&rbd_dev->watch_mutex);
4883         rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
4884         INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);
4885
4886         init_rwsem(&rbd_dev->lock_rwsem);
4887         rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
4888         INIT_WORK(&rbd_dev->acquired_lock_work, rbd_notify_acquired_lock);
4889         INIT_WORK(&rbd_dev->released_lock_work, rbd_notify_released_lock);
4890         INIT_DELAYED_WORK(&rbd_dev->lock_dwork, rbd_acquire_lock);
4891         INIT_WORK(&rbd_dev->unlock_work, rbd_release_lock_work);
4892         init_waitqueue_head(&rbd_dev->lock_waitq);
4893
4894         rbd_dev->dev.bus = &rbd_bus_type;
4895         rbd_dev->dev.type = &rbd_device_type;
4896         rbd_dev->dev.parent = &rbd_root_dev;
4897         device_initialize(&rbd_dev->dev);
4898
4899         rbd_dev->rbd_client = rbdc;
4900         rbd_dev->spec = spec;
4901
4902         rbd_dev->layout.stripe_unit = 1 << RBD_MAX_OBJ_ORDER;
4903         rbd_dev->layout.stripe_count = 1;
4904         rbd_dev->layout.object_size = 1 << RBD_MAX_OBJ_ORDER;
4905         rbd_dev->layout.pool_id = spec->pool_id;
4906         RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
4907
4908         return rbd_dev;
4909 }
4910
4911 /*
4912  * Create a mapping rbd_dev.
4913  */
4914 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
4915                                          struct rbd_spec *spec,
4916                                          struct rbd_options *opts)
4917 {
4918         struct rbd_device *rbd_dev;
4919
4920         rbd_dev = __rbd_dev_create(rbdc, spec);
4921         if (!rbd_dev)
4922                 return NULL;
4923
4924         rbd_dev->opts = opts;
4925
4926         /* get an id and fill in device name */
4927         rbd_dev->dev_id = ida_simple_get(&rbd_dev_id_ida, 0,
4928                                          minor_to_rbd_dev_id(1 << MINORBITS),
4929                                          GFP_KERNEL);
4930         if (rbd_dev->dev_id < 0)
4931                 goto fail_rbd_dev;
4932
4933         sprintf(rbd_dev->name, RBD_DRV_NAME "%d", rbd_dev->dev_id);
4934         rbd_dev->task_wq = alloc_ordered_workqueue("%s-tasks", WQ_MEM_RECLAIM,
4935                                                    rbd_dev->name);
4936         if (!rbd_dev->task_wq)
4937                 goto fail_dev_id;
4938
4939         /* we have a ref from do_rbd_add() */
4940         __module_get(THIS_MODULE);
4941
4942         dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
4943         return rbd_dev;
4944
4945 fail_dev_id:
4946         ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
4947 fail_rbd_dev:
4948         rbd_dev_free(rbd_dev);
4949         return NULL;
4950 }
4951
4952 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
4953 {
4954         if (rbd_dev)
4955                 put_device(&rbd_dev->dev);
4956 }
4957
4958 /*
4959  * Get the size and object order for an image snapshot, or if
4960  * snap_id is CEPH_NOSNAP, gets this information for the base
4961  * image.
4962  */
4963 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
4964                                 u8 *order, u64 *snap_size)
4965 {
4966         __le64 snapid = cpu_to_le64(snap_id);
4967         int ret;
4968         struct {
4969                 u8 order;
4970                 __le64 size;
4971         } __attribute__ ((packed)) size_buf = { 0 };
4972
4973         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
4974                                 "rbd", "get_size",
4975                                 &snapid, sizeof (snapid),
4976                                 &size_buf, sizeof (size_buf));
4977         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4978         if (ret < 0)
4979                 return ret;
4980         if (ret < sizeof (size_buf))
4981                 return -ERANGE;
4982
4983         if (order) {
4984                 *order = size_buf.order;
4985                 dout("  order %u", (unsigned int)*order);
4986         }
4987         *snap_size = le64_to_cpu(size_buf.size);
4988
4989         dout("  snap_id 0x%016llx snap_size = %llu\n",
4990                 (unsigned long long)snap_id,
4991                 (unsigned long long)*snap_size);
4992
4993         return 0;
4994 }
4995
4996 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
4997 {
4998         return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
4999                                         &rbd_dev->header.obj_order,
5000                                         &rbd_dev->header.image_size);
5001 }
5002
5003 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
5004 {
5005         void *reply_buf;
5006         int ret;
5007         void *p;
5008
5009         reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL);
5010         if (!reply_buf)
5011                 return -ENOMEM;
5012
5013         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5014                                 "rbd", "get_object_prefix", NULL, 0,
5015                                 reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
5016         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5017         if (ret < 0)
5018                 goto out;
5019
5020         p = reply_buf;
5021         rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
5022                                                 p + ret, NULL, GFP_NOIO);
5023         ret = 0;
5024
5025         if (IS_ERR(rbd_dev->header.object_prefix)) {
5026                 ret = PTR_ERR(rbd_dev->header.object_prefix);
5027                 rbd_dev->header.object_prefix = NULL;
5028         } else {
5029                 dout("  object_prefix = %s\n", rbd_dev->header.object_prefix);
5030         }
5031 out:
5032         kfree(reply_buf);
5033
5034         return ret;
5035 }
5036
5037 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
5038                 u64 *snap_features)
5039 {
5040         __le64 snapid = cpu_to_le64(snap_id);
5041         struct {
5042                 __le64 features;
5043                 __le64 incompat;
5044         } __attribute__ ((packed)) features_buf = { 0 };
5045         u64 unsup;
5046         int ret;
5047
5048         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5049                                 "rbd", "get_features",
5050                                 &snapid, sizeof (snapid),
5051                                 &features_buf, sizeof (features_buf));
5052         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5053         if (ret < 0)
5054                 return ret;
5055         if (ret < sizeof (features_buf))
5056                 return -ERANGE;
5057
5058         unsup = le64_to_cpu(features_buf.incompat) & ~RBD_FEATURES_SUPPORTED;
5059         if (unsup) {
5060                 rbd_warn(rbd_dev, "image uses unsupported features: 0x%llx",
5061                          unsup);
5062                 return -ENXIO;
5063         }
5064
5065         *snap_features = le64_to_cpu(features_buf.features);
5066
5067         dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
5068                 (unsigned long long)snap_id,
5069                 (unsigned long long)*snap_features,
5070                 (unsigned long long)le64_to_cpu(features_buf.incompat));
5071
5072         return 0;
5073 }
5074
5075 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
5076 {
5077         return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
5078                                                 &rbd_dev->header.features);
5079 }
5080
5081 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
5082 {
5083         struct rbd_spec *parent_spec;
5084         size_t size;
5085         void *reply_buf = NULL;
5086         __le64 snapid;
5087         void *p;
5088         void *end;
5089         u64 pool_id;
5090         char *image_id;
5091         u64 snap_id;
5092         u64 overlap;
5093         int ret;
5094
5095         parent_spec = rbd_spec_alloc();
5096         if (!parent_spec)
5097                 return -ENOMEM;
5098
5099         size = sizeof (__le64) +                                /* pool_id */
5100                 sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX +        /* image_id */
5101                 sizeof (__le64) +                               /* snap_id */
5102                 sizeof (__le64);                                /* overlap */
5103         reply_buf = kmalloc(size, GFP_KERNEL);
5104         if (!reply_buf) {
5105                 ret = -ENOMEM;
5106                 goto out_err;
5107         }
5108
5109         snapid = cpu_to_le64(rbd_dev->spec->snap_id);
5110         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5111                                 "rbd", "get_parent",
5112                                 &snapid, sizeof (snapid),
5113                                 reply_buf, size);
5114         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5115         if (ret < 0)
5116                 goto out_err;
5117
5118         p = reply_buf;
5119         end = reply_buf + ret;
5120         ret = -ERANGE;
5121         ceph_decode_64_safe(&p, end, pool_id, out_err);
5122         if (pool_id == CEPH_NOPOOL) {
5123                 /*
5124                  * Either the parent never existed, or we have
5125                  * record of it but the image got flattened so it no
5126                  * longer has a parent.  When the parent of a
5127                  * layered image disappears we immediately set the
5128                  * overlap to 0.  The effect of this is that all new
5129                  * requests will be treated as if the image had no
5130                  * parent.
5131                  */
5132                 if (rbd_dev->parent_overlap) {
5133                         rbd_dev->parent_overlap = 0;
5134                         rbd_dev_parent_put(rbd_dev);
5135                         pr_info("%s: clone image has been flattened\n",
5136                                 rbd_dev->disk->disk_name);
5137                 }
5138
5139                 goto out;       /* No parent?  No problem. */
5140         }
5141
5142         /* The ceph file layout needs to fit pool id in 32 bits */
5143
5144         ret = -EIO;
5145         if (pool_id > (u64)U32_MAX) {
5146                 rbd_warn(NULL, "parent pool id too large (%llu > %u)",
5147                         (unsigned long long)pool_id, U32_MAX);
5148                 goto out_err;
5149         }
5150
5151         image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5152         if (IS_ERR(image_id)) {
5153                 ret = PTR_ERR(image_id);
5154                 goto out_err;
5155         }
5156         ceph_decode_64_safe(&p, end, snap_id, out_err);
5157         ceph_decode_64_safe(&p, end, overlap, out_err);
5158
5159         /*
5160          * The parent won't change (except when the clone is
5161          * flattened, already handled that).  So we only need to
5162          * record the parent spec we have not already done so.
5163          */
5164         if (!rbd_dev->parent_spec) {
5165                 parent_spec->pool_id = pool_id;
5166                 parent_spec->image_id = image_id;
5167                 parent_spec->snap_id = snap_id;
5168                 rbd_dev->parent_spec = parent_spec;
5169                 parent_spec = NULL;     /* rbd_dev now owns this */
5170         } else {
5171                 kfree(image_id);
5172         }
5173
5174         /*
5175          * We always update the parent overlap.  If it's zero we issue
5176          * a warning, as we will proceed as if there was no parent.
5177          */
5178         if (!overlap) {
5179                 if (parent_spec) {
5180                         /* refresh, careful to warn just once */
5181                         if (rbd_dev->parent_overlap)
5182                                 rbd_warn(rbd_dev,
5183                                     "clone now standalone (overlap became 0)");
5184                 } else {
5185                         /* initial probe */
5186                         rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
5187                 }
5188         }
5189         rbd_dev->parent_overlap = overlap;
5190
5191 out:
5192         ret = 0;
5193 out_err:
5194         kfree(reply_buf);
5195         rbd_spec_put(parent_spec);
5196
5197         return ret;
5198 }
5199
5200 static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
5201 {
5202         struct {
5203                 __le64 stripe_unit;
5204                 __le64 stripe_count;
5205         } __attribute__ ((packed)) striping_info_buf = { 0 };
5206         size_t size = sizeof (striping_info_buf);
5207         void *p;
5208         u64 obj_size;
5209         u64 stripe_unit;
5210         u64 stripe_count;
5211         int ret;
5212
5213         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5214                                 "rbd", "get_stripe_unit_count", NULL, 0,
5215                                 (char *)&striping_info_buf, size);
5216         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5217         if (ret < 0)
5218                 return ret;
5219         if (ret < size)
5220                 return -ERANGE;
5221
5222         /*
5223          * We don't actually support the "fancy striping" feature
5224          * (STRIPINGV2) yet, but if the striping sizes are the
5225          * defaults the behavior is the same as before.  So find
5226          * out, and only fail if the image has non-default values.
5227          */
5228         ret = -EINVAL;
5229         obj_size = (u64)1 << rbd_dev->header.obj_order;
5230         p = &striping_info_buf;
5231         stripe_unit = ceph_decode_64(&p);
5232         if (stripe_unit != obj_size) {
5233                 rbd_warn(rbd_dev, "unsupported stripe unit "
5234                                 "(got %llu want %llu)",
5235                                 stripe_unit, obj_size);
5236                 return -EINVAL;
5237         }
5238         stripe_count = ceph_decode_64(&p);
5239         if (stripe_count != 1) {
5240                 rbd_warn(rbd_dev, "unsupported stripe count "
5241                                 "(got %llu want 1)", stripe_count);
5242                 return -EINVAL;
5243         }
5244         rbd_dev->header.stripe_unit = stripe_unit;
5245         rbd_dev->header.stripe_count = stripe_count;
5246
5247         return 0;
5248 }
5249
5250 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
5251 {
5252         size_t image_id_size;
5253         char *image_id;
5254         void *p;
5255         void *end;
5256         size_t size;
5257         void *reply_buf = NULL;
5258         size_t len = 0;
5259         char *image_name = NULL;
5260         int ret;
5261
5262         rbd_assert(!rbd_dev->spec->image_name);
5263
5264         len = strlen(rbd_dev->spec->image_id);
5265         image_id_size = sizeof (__le32) + len;
5266         image_id = kmalloc(image_id_size, GFP_KERNEL);
5267         if (!image_id)
5268                 return NULL;
5269
5270         p = image_id;
5271         end = image_id + image_id_size;
5272         ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
5273
5274         size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
5275         reply_buf = kmalloc(size, GFP_KERNEL);
5276         if (!reply_buf)
5277                 goto out;
5278
5279         ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
5280                                 "rbd", "dir_get_name",
5281                                 image_id, image_id_size,
5282                                 reply_buf, size);
5283         if (ret < 0)
5284                 goto out;
5285         p = reply_buf;
5286         end = reply_buf + ret;
5287
5288         image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
5289         if (IS_ERR(image_name))
5290                 image_name = NULL;
5291         else
5292                 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
5293 out:
5294         kfree(reply_buf);
5295         kfree(image_id);
5296
5297         return image_name;
5298 }
5299
5300 static u64 rbd_v1_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
5301 {
5302         struct ceph_snap_context *snapc = rbd_dev->header.snapc;
5303         const char *snap_name;
5304         u32 which = 0;
5305
5306         /* Skip over names until we find the one we are looking for */
5307
5308         snap_name = rbd_dev->header.snap_names;
5309         while (which < snapc->num_snaps) {
5310                 if (!strcmp(name, snap_name))
5311                         return snapc->snaps[which];
5312                 snap_name += strlen(snap_name) + 1;
5313                 which++;
5314         }
5315         return CEPH_NOSNAP;
5316 }
5317
5318 static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
5319 {
5320         struct ceph_snap_context *snapc = rbd_dev->header.snapc;
5321         u32 which;
5322         bool found = false;
5323         u64 snap_id;
5324
5325         for (which = 0; !found && which < snapc->num_snaps; which++) {
5326                 const char *snap_name;
5327
5328                 snap_id = snapc->snaps[which];
5329                 snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
5330                 if (IS_ERR(snap_name)) {
5331                         /* ignore no-longer existing snapshots */
5332                         if (PTR_ERR(snap_name) == -ENOENT)
5333                                 continue;
5334                         else
5335                                 break;
5336                 }
5337                 found = !strcmp(name, snap_name);
5338                 kfree(snap_name);
5339         }
5340         return found ? snap_id : CEPH_NOSNAP;
5341 }
5342
5343 /*
5344  * Assumes name is never RBD_SNAP_HEAD_NAME; returns CEPH_NOSNAP if
5345  * no snapshot by that name is found, or if an error occurs.
5346  */
5347 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
5348 {
5349         if (rbd_dev->image_format == 1)
5350                 return rbd_v1_snap_id_by_name(rbd_dev, name);
5351
5352         return rbd_v2_snap_id_by_name(rbd_dev, name);
5353 }
5354
5355 /*
5356  * An image being mapped will have everything but the snap id.
5357  */
5358 static int rbd_spec_fill_snap_id(struct rbd_device *rbd_dev)
5359 {
5360         struct rbd_spec *spec = rbd_dev->spec;
5361
5362         rbd_assert(spec->pool_id != CEPH_NOPOOL && spec->pool_name);
5363         rbd_assert(spec->image_id && spec->image_name);
5364         rbd_assert(spec->snap_name);
5365
5366         if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
5367                 u64 snap_id;
5368
5369                 snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name);
5370                 if (snap_id == CEPH_NOSNAP)
5371                         return -ENOENT;
5372
5373                 spec->snap_id = snap_id;
5374         } else {
5375                 spec->snap_id = CEPH_NOSNAP;
5376         }
5377
5378         return 0;
5379 }
5380
5381 /*
5382  * A parent image will have all ids but none of the names.
5383  *
5384  * All names in an rbd spec are dynamically allocated.  It's OK if we
5385  * can't figure out the name for an image id.
5386  */
5387 static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
5388 {
5389         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
5390         struct rbd_spec *spec = rbd_dev->spec;
5391         const char *pool_name;
5392         const char *image_name;
5393         const char *snap_name;
5394         int ret;
5395
5396         rbd_assert(spec->pool_id != CEPH_NOPOOL);
5397         rbd_assert(spec->image_id);
5398         rbd_assert(spec->snap_id != CEPH_NOSNAP);
5399
5400         /* Get the pool name; we have to make our own copy of this */
5401
5402         pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
5403         if (!pool_name) {
5404                 rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
5405                 return -EIO;
5406         }
5407         pool_name = kstrdup(pool_name, GFP_KERNEL);
5408         if (!pool_name)
5409                 return -ENOMEM;
5410
5411         /* Fetch the image name; tolerate failure here */
5412
5413         image_name = rbd_dev_image_name(rbd_dev);
5414         if (!image_name)
5415                 rbd_warn(rbd_dev, "unable to get image name");
5416
5417         /* Fetch the snapshot name */
5418
5419         snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
5420         if (IS_ERR(snap_name)) {
5421                 ret = PTR_ERR(snap_name);
5422                 goto out_err;
5423         }
5424
5425         spec->pool_name = pool_name;
5426         spec->image_name = image_name;
5427         spec->snap_name = snap_name;
5428
5429         return 0;
5430
5431 out_err:
5432         kfree(image_name);
5433         kfree(pool_name);
5434         return ret;
5435 }
5436
5437 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
5438 {
5439         size_t size;
5440         int ret;
5441         void *reply_buf;
5442         void *p;
5443         void *end;
5444         u64 seq;
5445         u32 snap_count;
5446         struct ceph_snap_context *snapc;
5447         u32 i;
5448
5449         /*
5450          * We'll need room for the seq value (maximum snapshot id),
5451          * snapshot count, and array of that many snapshot ids.
5452          * For now we have a fixed upper limit on the number we're
5453          * prepared to receive.
5454          */
5455         size = sizeof (__le64) + sizeof (__le32) +
5456                         RBD_MAX_SNAP_COUNT * sizeof (__le64);
5457         reply_buf = kzalloc(size, GFP_KERNEL);
5458         if (!reply_buf)
5459                 return -ENOMEM;
5460
5461         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5462                                 "rbd", "get_snapcontext", NULL, 0,
5463                                 reply_buf, size);
5464         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5465         if (ret < 0)
5466                 goto out;
5467
5468         p = reply_buf;
5469         end = reply_buf + ret;
5470         ret = -ERANGE;
5471         ceph_decode_64_safe(&p, end, seq, out);
5472         ceph_decode_32_safe(&p, end, snap_count, out);
5473
5474         /*
5475          * Make sure the reported number of snapshot ids wouldn't go
5476          * beyond the end of our buffer.  But before checking that,
5477          * make sure the computed size of the snapshot context we
5478          * allocate is representable in a size_t.
5479          */
5480         if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
5481                                  / sizeof (u64)) {
5482                 ret = -EINVAL;
5483                 goto out;
5484         }
5485         if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
5486                 goto out;
5487         ret = 0;
5488
5489         snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
5490         if (!snapc) {
5491                 ret = -ENOMEM;
5492                 goto out;
5493         }
5494         snapc->seq = seq;
5495         for (i = 0; i < snap_count; i++)
5496                 snapc->snaps[i] = ceph_decode_64(&p);
5497
5498         ceph_put_snap_context(rbd_dev->header.snapc);
5499         rbd_dev->header.snapc = snapc;
5500
5501         dout("  snap context seq = %llu, snap_count = %u\n",
5502                 (unsigned long long)seq, (unsigned int)snap_count);
5503 out:
5504         kfree(reply_buf);
5505
5506         return ret;
5507 }
5508
5509 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
5510                                         u64 snap_id)
5511 {
5512         size_t size;
5513         void *reply_buf;
5514         __le64 snapid;
5515         int ret;
5516         void *p;
5517         void *end;
5518         char *snap_name;
5519
5520         size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
5521         reply_buf = kmalloc(size, GFP_KERNEL);
5522         if (!reply_buf)
5523                 return ERR_PTR(-ENOMEM);
5524
5525         snapid = cpu_to_le64(snap_id);
5526         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5527                                 "rbd", "get_snapshot_name",
5528                                 &snapid, sizeof (snapid),
5529                                 reply_buf, size);
5530         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5531         if (ret < 0) {
5532                 snap_name = ERR_PTR(ret);
5533                 goto out;
5534         }
5535
5536         p = reply_buf;
5537         end = reply_buf + ret;
5538         snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5539         if (IS_ERR(snap_name))
5540                 goto out;
5541
5542         dout("  snap_id 0x%016llx snap_name = %s\n",
5543                 (unsigned long long)snap_id, snap_name);
5544 out:
5545         kfree(reply_buf);
5546
5547         return snap_name;
5548 }
5549
5550 static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
5551 {
5552         bool first_time = rbd_dev->header.object_prefix == NULL;
5553         int ret;
5554
5555         ret = rbd_dev_v2_image_size(rbd_dev);
5556         if (ret)
5557                 return ret;
5558
5559         if (first_time) {
5560                 ret = rbd_dev_v2_header_onetime(rbd_dev);
5561                 if (ret)
5562                         return ret;
5563         }
5564
5565         ret = rbd_dev_v2_snap_context(rbd_dev);
5566         if (ret && first_time) {
5567                 kfree(rbd_dev->header.object_prefix);
5568                 rbd_dev->header.object_prefix = NULL;
5569         }
5570
5571         return ret;
5572 }
5573
5574 static int rbd_dev_header_info(struct rbd_device *rbd_dev)
5575 {
5576         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
5577
5578         if (rbd_dev->image_format == 1)
5579                 return rbd_dev_v1_header_info(rbd_dev);
5580
5581         return rbd_dev_v2_header_info(rbd_dev);
5582 }
5583
5584 /*
5585  * Skips over white space at *buf, and updates *buf to point to the
5586  * first found non-space character (if any). Returns the length of
5587  * the token (string of non-white space characters) found.  Note
5588  * that *buf must be terminated with '\0'.
5589  */
5590 static inline size_t next_token(const char **buf)
5591 {
5592         /*
5593         * These are the characters that produce nonzero for
5594         * isspace() in the "C" and "POSIX" locales.
5595         */
5596         const char *spaces = " \f\n\r\t\v";
5597
5598         *buf += strspn(*buf, spaces);   /* Find start of token */
5599
5600         return strcspn(*buf, spaces);   /* Return token length */
5601 }
5602
5603 /*
5604  * Finds the next token in *buf, dynamically allocates a buffer big
5605  * enough to hold a copy of it, and copies the token into the new
5606  * buffer.  The copy is guaranteed to be terminated with '\0'.  Note
5607  * that a duplicate buffer is created even for a zero-length token.
5608  *
5609  * Returns a pointer to the newly-allocated duplicate, or a null
5610  * pointer if memory for the duplicate was not available.  If
5611  * the lenp argument is a non-null pointer, the length of the token
5612  * (not including the '\0') is returned in *lenp.
5613  *
5614  * If successful, the *buf pointer will be updated to point beyond
5615  * the end of the found token.
5616  *
5617  * Note: uses GFP_KERNEL for allocation.
5618  */
5619 static inline char *dup_token(const char **buf, size_t *lenp)
5620 {
5621         char *dup;
5622         size_t len;
5623
5624         len = next_token(buf);
5625         dup = kmemdup(*buf, len + 1, GFP_KERNEL);
5626         if (!dup)
5627                 return NULL;
5628         *(dup + len) = '\0';
5629         *buf += len;
5630
5631         if (lenp)
5632                 *lenp = len;
5633
5634         return dup;
5635 }
5636
5637 /*
5638  * Parse the options provided for an "rbd add" (i.e., rbd image
5639  * mapping) request.  These arrive via a write to /sys/bus/rbd/add,
5640  * and the data written is passed here via a NUL-terminated buffer.
5641  * Returns 0 if successful or an error code otherwise.
5642  *
5643  * The information extracted from these options is recorded in
5644  * the other parameters which return dynamically-allocated
5645  * structures:
5646  *  ceph_opts
5647  *      The address of a pointer that will refer to a ceph options
5648  *      structure.  Caller must release the returned pointer using
5649  *      ceph_destroy_options() when it is no longer needed.
5650  *  rbd_opts
5651  *      Address of an rbd options pointer.  Fully initialized by
5652  *      this function; caller must release with kfree().
5653  *  spec
5654  *      Address of an rbd image specification pointer.  Fully
5655  *      initialized by this function based on parsed options.
5656  *      Caller must release with rbd_spec_put().
5657  *
5658  * The options passed take this form:
5659  *  <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
5660  * where:
5661  *  <mon_addrs>
5662  *      A comma-separated list of one or more monitor addresses.
5663  *      A monitor address is an ip address, optionally followed
5664  *      by a port number (separated by a colon).
5665  *        I.e.:  ip1[:port1][,ip2[:port2]...]
5666  *  <options>
5667  *      A comma-separated list of ceph and/or rbd options.
5668  *  <pool_name>
5669  *      The name of the rados pool containing the rbd image.
5670  *  <image_name>
5671  *      The name of the image in that pool to map.
5672  *  <snap_id>
5673  *      An optional snapshot id.  If provided, the mapping will
5674  *      present data from the image at the time that snapshot was
5675  *      created.  The image head is used if no snapshot id is
5676  *      provided.  Snapshot mappings are always read-only.
5677  */
5678 static int rbd_add_parse_args(const char *buf,
5679                                 struct ceph_options **ceph_opts,
5680                                 struct rbd_options **opts,
5681                                 struct rbd_spec **rbd_spec)
5682 {
5683         size_t len;
5684         char *options;
5685         const char *mon_addrs;
5686         char *snap_name;
5687         size_t mon_addrs_size;
5688         struct rbd_spec *spec = NULL;
5689         struct rbd_options *rbd_opts = NULL;
5690         struct ceph_options *copts;
5691         int ret;
5692
5693         /* The first four tokens are required */
5694
5695         len = next_token(&buf);
5696         if (!len) {
5697                 rbd_warn(NULL, "no monitor address(es) provided");
5698                 return -EINVAL;
5699         }
5700         mon_addrs = buf;
5701         mon_addrs_size = len + 1;
5702         buf += len;
5703
5704         ret = -EINVAL;
5705         options = dup_token(&buf, NULL);
5706         if (!options)
5707                 return -ENOMEM;
5708         if (!*options) {
5709                 rbd_warn(NULL, "no options provided");
5710                 goto out_err;
5711         }
5712
5713         spec = rbd_spec_alloc();
5714         if (!spec)
5715                 goto out_mem;
5716
5717         spec->pool_name = dup_token(&buf, NULL);
5718         if (!spec->pool_name)
5719                 goto out_mem;
5720         if (!*spec->pool_name) {
5721                 rbd_warn(NULL, "no pool name provided");
5722                 goto out_err;
5723         }
5724
5725         spec->image_name = dup_token(&buf, NULL);
5726         if (!spec->image_name)
5727                 goto out_mem;
5728         if (!*spec->image_name) {
5729                 rbd_warn(NULL, "no image name provided");
5730                 goto out_err;
5731         }
5732
5733         /*
5734          * Snapshot name is optional; default is to use "-"
5735          * (indicating the head/no snapshot).
5736          */
5737         len = next_token(&buf);
5738         if (!len) {
5739                 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
5740                 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5741         } else if (len > RBD_MAX_SNAP_NAME_LEN) {
5742                 ret = -ENAMETOOLONG;
5743                 goto out_err;
5744         }
5745         snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
5746         if (!snap_name)
5747                 goto out_mem;
5748         *(snap_name + len) = '\0';
5749         spec->snap_name = snap_name;
5750
5751         /* Initialize all rbd options to the defaults */
5752
5753         rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
5754         if (!rbd_opts)
5755                 goto out_mem;
5756
5757         rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
5758         rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
5759         rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
5760
5761         copts = ceph_parse_options(options, mon_addrs,
5762                                         mon_addrs + mon_addrs_size - 1,
5763                                         parse_rbd_opts_token, rbd_opts);
5764         if (IS_ERR(copts)) {
5765                 ret = PTR_ERR(copts);
5766                 goto out_err;
5767         }
5768         kfree(options);
5769
5770         *ceph_opts = copts;
5771         *opts = rbd_opts;
5772         *rbd_spec = spec;
5773
5774         return 0;
5775 out_mem:
5776         ret = -ENOMEM;
5777 out_err:
5778         kfree(rbd_opts);
5779         rbd_spec_put(spec);
5780         kfree(options);
5781
5782         return ret;
5783 }
5784
5785 /*
5786  * Return pool id (>= 0) or a negative error code.
5787  */
5788 static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
5789 {
5790         struct ceph_options *opts = rbdc->client->options;
5791         u64 newest_epoch;
5792         int tries = 0;
5793         int ret;
5794
5795 again:
5796         ret = ceph_pg_poolid_by_name(rbdc->client->osdc.osdmap, pool_name);
5797         if (ret == -ENOENT && tries++ < 1) {
5798                 ret = ceph_monc_get_version(&rbdc->client->monc, "osdmap",
5799                                             &newest_epoch);
5800                 if (ret < 0)
5801                         return ret;
5802
5803                 if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
5804                         ceph_osdc_maybe_request_map(&rbdc->client->osdc);
5805                         (void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5806                                                      newest_epoch,
5807                                                      opts->mount_timeout);
5808                         goto again;
5809                 } else {
5810                         /* the osdmap we have is new enough */
5811                         return -ENOENT;
5812                 }
5813         }
5814
5815         return ret;
5816 }
5817
5818 /*
5819  * An rbd format 2 image has a unique identifier, distinct from the
5820  * name given to it by the user.  Internally, that identifier is
5821  * what's used to specify the names of objects related to the image.
5822  *
5823  * A special "rbd id" object is used to map an rbd image name to its
5824  * id.  If that object doesn't exist, then there is no v2 rbd image
5825  * with the supplied name.
5826  *
5827  * This function will record the given rbd_dev's image_id field if
5828  * it can be determined, and in that case will return 0.  If any
5829  * errors occur a negative errno will be returned and the rbd_dev's
5830  * image_id field will be unchanged (and should be NULL).
5831  */
5832 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
5833 {
5834         int ret;
5835         size_t size;
5836         char *object_name;
5837         void *response;
5838         char *image_id;
5839
5840         /*
5841          * When probing a parent image, the image id is already
5842          * known (and the image name likely is not).  There's no
5843          * need to fetch the image id again in this case.  We
5844          * do still need to set the image format though.
5845          */
5846         if (rbd_dev->spec->image_id) {
5847                 rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
5848
5849                 return 0;
5850         }
5851
5852         /*
5853          * First, see if the format 2 image id file exists, and if
5854          * so, get the image's persistent id from it.
5855          */
5856         size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
5857         object_name = kmalloc(size, GFP_NOIO);
5858         if (!object_name)
5859                 return -ENOMEM;
5860         sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
5861         dout("rbd id object name is %s\n", object_name);
5862
5863         /* Response will be an encoded string, which includes a length */
5864
5865         size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
5866         response = kzalloc(size, GFP_NOIO);
5867         if (!response) {
5868                 ret = -ENOMEM;
5869                 goto out;
5870         }
5871
5872         /* If it doesn't exist we'll assume it's a format 1 image */
5873
5874         ret = rbd_obj_method_sync(rbd_dev, object_name,
5875                                 "rbd", "get_id", NULL, 0,
5876                                 response, RBD_IMAGE_ID_LEN_MAX);
5877         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5878         if (ret == -ENOENT) {
5879                 image_id = kstrdup("", GFP_KERNEL);
5880                 ret = image_id ? 0 : -ENOMEM;
5881                 if (!ret)
5882                         rbd_dev->image_format = 1;
5883         } else if (ret >= 0) {
5884                 void *p = response;
5885
5886                 image_id = ceph_extract_encoded_string(&p, p + ret,
5887                                                 NULL, GFP_NOIO);
5888                 ret = PTR_ERR_OR_ZERO(image_id);
5889                 if (!ret)
5890                         rbd_dev->image_format = 2;
5891         }
5892
5893         if (!ret) {
5894                 rbd_dev->spec->image_id = image_id;
5895                 dout("image_id is %s\n", image_id);
5896         }
5897 out:
5898         kfree(response);
5899         kfree(object_name);
5900
5901         return ret;
5902 }
5903
5904 /*
5905  * Undo whatever state changes are made by v1 or v2 header info
5906  * call.
5907  */
5908 static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
5909 {
5910         struct rbd_image_header *header;
5911
5912         rbd_dev_parent_put(rbd_dev);
5913
5914         /* Free dynamic fields from the header, then zero it out */
5915
5916         header = &rbd_dev->header;
5917         ceph_put_snap_context(header->snapc);
5918         kfree(header->snap_sizes);
5919         kfree(header->snap_names);
5920         kfree(header->object_prefix);
5921         memset(header, 0, sizeof (*header));
5922 }
5923
5924 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5925 {
5926         int ret;
5927
5928         ret = rbd_dev_v2_object_prefix(rbd_dev);
5929         if (ret)
5930                 goto out_err;
5931
5932         /*
5933          * Get the and check features for the image.  Currently the
5934          * features are assumed to never change.
5935          */
5936         ret = rbd_dev_v2_features(rbd_dev);
5937         if (ret)
5938                 goto out_err;
5939
5940         /* If the image supports fancy striping, get its parameters */
5941
5942         if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
5943                 ret = rbd_dev_v2_striping_info(rbd_dev);
5944                 if (ret < 0)
5945                         goto out_err;
5946         }
5947         /* No support for crypto and compression type format 2 images */
5948
5949         return 0;
5950 out_err:
5951         rbd_dev->header.features = 0;
5952         kfree(rbd_dev->header.object_prefix);
5953         rbd_dev->header.object_prefix = NULL;
5954
5955         return ret;
5956 }
5957
5958 /*
5959  * @depth is rbd_dev_image_probe() -> rbd_dev_probe_parent() ->
5960  * rbd_dev_image_probe() recursion depth, which means it's also the
5961  * length of the already discovered part of the parent chain.
5962  */
5963 static int rbd_dev_probe_parent(struct rbd_device *rbd_dev, int depth)
5964 {
5965         struct rbd_device *parent = NULL;
5966         int ret;
5967
5968         if (!rbd_dev->parent_spec)
5969                 return 0;
5970
5971         if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
5972                 pr_info("parent chain is too long (%d)\n", depth);
5973                 ret = -EINVAL;
5974                 goto out_err;
5975         }
5976
5977         parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5978         if (!parent) {
5979                 ret = -ENOMEM;
5980                 goto out_err;
5981         }
5982
5983         /*
5984          * Images related by parent/child relationships always share
5985          * rbd_client and spec/parent_spec, so bump their refcounts.
5986          */
5987         __rbd_get_client(rbd_dev->rbd_client);
5988         rbd_spec_get(rbd_dev->parent_spec);
5989
5990         ret = rbd_dev_image_probe(parent, depth);
5991         if (ret < 0)
5992                 goto out_err;
5993
5994         rbd_dev->parent = parent;
5995         atomic_set(&rbd_dev->parent_ref, 1);
5996         return 0;
5997
5998 out_err:
5999         rbd_dev_unparent(rbd_dev);
6000         rbd_dev_destroy(parent);
6001         return ret;
6002 }
6003
6004 /*
6005  * rbd_dev->header_rwsem must be locked for write and will be unlocked
6006  * upon return.
6007  */
6008 static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
6009 {
6010         int ret;
6011
6012         /* Record our major and minor device numbers. */
6013
6014         if (!single_major) {
6015                 ret = register_blkdev(0, rbd_dev->name);
6016                 if (ret < 0)
6017                         goto err_out_unlock;
6018
6019                 rbd_dev->major = ret;
6020                 rbd_dev->minor = 0;
6021         } else {
6022                 rbd_dev->major = rbd_major;
6023                 rbd_dev->minor = rbd_dev_id_to_minor(rbd_dev->dev_id);
6024         }
6025
6026         /* Set up the blkdev mapping. */
6027
6028         ret = rbd_init_disk(rbd_dev);
6029         if (ret)
6030                 goto err_out_blkdev;
6031
6032         ret = rbd_dev_mapping_set(rbd_dev);
6033         if (ret)
6034                 goto err_out_disk;
6035
6036         set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
6037         set_disk_ro(rbd_dev->disk, rbd_dev->mapping.read_only);
6038
6039         dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
6040         ret = device_add(&rbd_dev->dev);
6041         if (ret)
6042                 goto err_out_mapping;
6043
6044         /* Everything's ready.  Announce the disk to the world. */
6045
6046         set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6047         up_write(&rbd_dev->header_rwsem);
6048
6049         spin_lock(&rbd_dev_list_lock);
6050         list_add_tail(&rbd_dev->node, &rbd_dev_list);
6051         spin_unlock(&rbd_dev_list_lock);
6052
6053         add_disk(rbd_dev->disk);
6054         pr_info("%s: capacity %llu features 0x%llx\n", rbd_dev->disk->disk_name,
6055                 (unsigned long long)get_capacity(rbd_dev->disk) << SECTOR_SHIFT,
6056                 rbd_dev->header.features);
6057
6058         return ret;
6059
6060 err_out_mapping:
6061         rbd_dev_mapping_clear(rbd_dev);
6062 err_out_disk:
6063         rbd_free_disk(rbd_dev);
6064 err_out_blkdev:
6065         if (!single_major)
6066                 unregister_blkdev(rbd_dev->major, rbd_dev->name);
6067 err_out_unlock:
6068         up_write(&rbd_dev->header_rwsem);
6069         return ret;
6070 }
6071
6072 static int rbd_dev_header_name(struct rbd_device *rbd_dev)
6073 {
6074         struct rbd_spec *spec = rbd_dev->spec;
6075         int ret;
6076
6077         /* Record the header object name for this rbd image. */
6078
6079         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
6080
6081         rbd_dev->header_oloc.pool = rbd_dev->layout.pool_id;
6082         if (rbd_dev->image_format == 1)
6083                 ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
6084                                        spec->image_name, RBD_SUFFIX);
6085         else
6086                 ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
6087                                        RBD_HEADER_PREFIX, spec->image_id);
6088
6089         return ret;
6090 }
6091
6092 static void rbd_dev_image_release(struct rbd_device *rbd_dev)
6093 {
6094         rbd_dev_unprobe(rbd_dev);
6095         rbd_dev->image_format = 0;
6096         kfree(rbd_dev->spec->image_id);
6097         rbd_dev->spec->image_id = NULL;
6098
6099         rbd_dev_destroy(rbd_dev);
6100 }
6101
6102 /*
6103  * Probe for the existence of the header object for the given rbd
6104  * device.  If this image is the one being mapped (i.e., not a
6105  * parent), initiate a watch on its header object before using that
6106  * object to get detailed information about the rbd image.
6107  */
6108 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
6109 {
6110         int ret;
6111
6112         /*
6113          * Get the id from the image id object.  Unless there's an
6114          * error, rbd_dev->spec->image_id will be filled in with
6115          * a dynamically-allocated string, and rbd_dev->image_format
6116          * will be set to either 1 or 2.
6117          */
6118         ret = rbd_dev_image_id(rbd_dev);
6119         if (ret)
6120                 return ret;
6121
6122         ret = rbd_dev_header_name(rbd_dev);
6123         if (ret)
6124                 goto err_out_format;
6125
6126         if (!depth) {
6127                 ret = rbd_register_watch(rbd_dev);
6128                 if (ret) {
6129                         if (ret == -ENOENT)
6130                                 pr_info("image %s/%s does not exist\n",
6131                                         rbd_dev->spec->pool_name,
6132                                         rbd_dev->spec->image_name);
6133                         goto err_out_format;
6134                 }
6135         }
6136
6137         ret = rbd_dev_header_info(rbd_dev);
6138         if (ret)
6139                 goto err_out_watch;
6140
6141         /*
6142          * If this image is the one being mapped, we have pool name and
6143          * id, image name and id, and snap name - need to fill snap id.
6144          * Otherwise this is a parent image, identified by pool, image
6145          * and snap ids - need to fill in names for those ids.
6146          */
6147         if (!depth)
6148                 ret = rbd_spec_fill_snap_id(rbd_dev);
6149         else
6150                 ret = rbd_spec_fill_names(rbd_dev);
6151         if (ret) {
6152                 if (ret == -ENOENT)
6153                         pr_info("snap %s/%s@%s does not exist\n",
6154                                 rbd_dev->spec->pool_name,
6155                                 rbd_dev->spec->image_name,
6156                                 rbd_dev->spec->snap_name);
6157                 goto err_out_probe;
6158         }
6159
6160         if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
6161                 ret = rbd_dev_v2_parent_info(rbd_dev);
6162                 if (ret)
6163                         goto err_out_probe;
6164
6165                 /*
6166                  * Need to warn users if this image is the one being
6167                  * mapped and has a parent.
6168                  */
6169                 if (!depth && rbd_dev->parent_spec)
6170                         rbd_warn(rbd_dev,
6171                                  "WARNING: kernel layering is EXPERIMENTAL!");
6172         }
6173
6174         ret = rbd_dev_probe_parent(rbd_dev, depth);
6175         if (ret)
6176                 goto err_out_probe;
6177
6178         dout("discovered format %u image, header name is %s\n",
6179                 rbd_dev->image_format, rbd_dev->header_oid.name);
6180         return 0;
6181
6182 err_out_probe:
6183         rbd_dev_unprobe(rbd_dev);
6184 err_out_watch:
6185         if (!depth)
6186                 rbd_unregister_watch(rbd_dev);
6187 err_out_format:
6188         rbd_dev->image_format = 0;
6189         kfree(rbd_dev->spec->image_id);
6190         rbd_dev->spec->image_id = NULL;
6191         return ret;
6192 }
6193
6194 static ssize_t do_rbd_add(struct bus_type *bus,
6195                           const char *buf,
6196                           size_t count)
6197 {
6198         struct rbd_device *rbd_dev = NULL;
6199         struct ceph_options *ceph_opts = NULL;
6200         struct rbd_options *rbd_opts = NULL;
6201         struct rbd_spec *spec = NULL;
6202         struct rbd_client *rbdc;
6203         bool read_only;
6204         int rc;
6205
6206         if (!try_module_get(THIS_MODULE))
6207                 return -ENODEV;
6208
6209         /* parse add command */
6210         rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
6211         if (rc < 0)
6212                 goto out;
6213
6214         rbdc = rbd_get_client(ceph_opts);
6215         if (IS_ERR(rbdc)) {
6216                 rc = PTR_ERR(rbdc);
6217                 goto err_out_args;
6218         }
6219
6220         /* pick the pool */
6221         rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
6222         if (rc < 0) {
6223                 if (rc == -ENOENT)
6224                         pr_info("pool %s does not exist\n", spec->pool_name);
6225                 goto err_out_client;
6226         }
6227         spec->pool_id = (u64)rc;
6228
6229         rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
6230         if (!rbd_dev) {
6231                 rc = -ENOMEM;
6232                 goto err_out_client;
6233         }
6234         rbdc = NULL;            /* rbd_dev now owns this */
6235         spec = NULL;            /* rbd_dev now owns this */
6236         rbd_opts = NULL;        /* rbd_dev now owns this */
6237
6238         rbd_dev->config_info = kstrdup(buf, GFP_KERNEL);
6239         if (!rbd_dev->config_info) {
6240                 rc = -ENOMEM;
6241                 goto err_out_rbd_dev;
6242         }
6243
6244         down_write(&rbd_dev->header_rwsem);
6245         rc = rbd_dev_image_probe(rbd_dev, 0);
6246         if (rc < 0) {
6247                 up_write(&rbd_dev->header_rwsem);
6248                 goto err_out_rbd_dev;
6249         }
6250
6251         /* If we are mapping a snapshot it must be marked read-only */
6252
6253         read_only = rbd_dev->opts->read_only;
6254         if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
6255                 read_only = true;
6256         rbd_dev->mapping.read_only = read_only;
6257
6258         rc = rbd_dev_device_setup(rbd_dev);
6259         if (rc) {
6260                 /*
6261                  * rbd_unregister_watch() can't be moved into
6262                  * rbd_dev_image_release() without refactoring, see
6263                  * commit 1f3ef78861ac.
6264                  */
6265                 rbd_unregister_watch(rbd_dev);
6266                 rbd_dev_image_release(rbd_dev);
6267                 goto out;
6268         }
6269
6270         rc = count;
6271 out:
6272         module_put(THIS_MODULE);
6273         return rc;
6274
6275 err_out_rbd_dev:
6276         rbd_dev_destroy(rbd_dev);
6277 err_out_client:
6278         rbd_put_client(rbdc);
6279 err_out_args:
6280         rbd_spec_put(spec);
6281         kfree(rbd_opts);
6282         goto out;
6283 }
6284
6285 static ssize_t rbd_add(struct bus_type *bus,
6286                        const char *buf,
6287                        size_t count)
6288 {
6289         if (single_major)
6290                 return -EINVAL;
6291
6292         return do_rbd_add(bus, buf, count);
6293 }
6294
6295 static ssize_t rbd_add_single_major(struct bus_type *bus,
6296                                     const char *buf,
6297                                     size_t count)
6298 {
6299         return do_rbd_add(bus, buf, count);
6300 }
6301
6302 static void rbd_dev_device_release(struct rbd_device *rbd_dev)
6303 {
6304         rbd_free_disk(rbd_dev);
6305
6306         spin_lock(&rbd_dev_list_lock);
6307         list_del_init(&rbd_dev->node);
6308         spin_unlock(&rbd_dev_list_lock);
6309
6310         clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6311         device_del(&rbd_dev->dev);
6312         rbd_dev_mapping_clear(rbd_dev);
6313         if (!single_major)
6314                 unregister_blkdev(rbd_dev->major, rbd_dev->name);
6315 }
6316
6317 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
6318 {
6319         while (rbd_dev->parent) {
6320                 struct rbd_device *first = rbd_dev;
6321                 struct rbd_device *second = first->parent;
6322                 struct rbd_device *third;
6323
6324                 /*
6325                  * Follow to the parent with no grandparent and
6326                  * remove it.
6327                  */
6328                 while (second && (third = second->parent)) {
6329                         first = second;
6330                         second = third;
6331                 }
6332                 rbd_assert(second);
6333                 rbd_dev_image_release(second);
6334                 first->parent = NULL;
6335                 first->parent_overlap = 0;
6336
6337                 rbd_assert(first->parent_spec);
6338                 rbd_spec_put(first->parent_spec);
6339                 first->parent_spec = NULL;
6340         }
6341 }
6342
6343 static ssize_t do_rbd_remove(struct bus_type *bus,
6344                              const char *buf,
6345                              size_t count)
6346 {
6347         struct rbd_device *rbd_dev = NULL;
6348         struct list_head *tmp;
6349         int dev_id;
6350         char opt_buf[6];
6351         bool already = false;
6352         bool force = false;
6353         int ret;
6354
6355         dev_id = -1;
6356         opt_buf[0] = '\0';
6357         sscanf(buf, "%d %5s", &dev_id, opt_buf);
6358         if (dev_id < 0) {
6359                 pr_err("dev_id out of range\n");
6360                 return -EINVAL;
6361         }
6362         if (opt_buf[0] != '\0') {
6363                 if (!strcmp(opt_buf, "force")) {
6364                         force = true;
6365                 } else {
6366                         pr_err("bad remove option at '%s'\n", opt_buf);
6367                         return -EINVAL;
6368                 }
6369         }
6370
6371         ret = -ENOENT;
6372         spin_lock(&rbd_dev_list_lock);
6373         list_for_each(tmp, &rbd_dev_list) {
6374                 rbd_dev = list_entry(tmp, struct rbd_device, node);
6375                 if (rbd_dev->dev_id == dev_id) {
6376                         ret = 0;
6377                         break;
6378                 }
6379         }
6380         if (!ret) {
6381                 spin_lock_irq(&rbd_dev->lock);
6382                 if (rbd_dev->open_count && !force)
6383                         ret = -EBUSY;
6384                 else
6385                         already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
6386                                                         &rbd_dev->flags);
6387                 spin_unlock_irq(&rbd_dev->lock);
6388         }
6389         spin_unlock(&rbd_dev_list_lock);
6390         if (ret < 0 || already)
6391                 return ret;
6392
6393         if (force) {
6394                 /*
6395                  * Prevent new IO from being queued and wait for existing
6396                  * IO to complete/fail.
6397                  */
6398                 blk_mq_freeze_queue(rbd_dev->disk->queue);
6399                 blk_set_queue_dying(rbd_dev->disk->queue);
6400         }
6401
6402         down_write(&rbd_dev->lock_rwsem);
6403         if (__rbd_is_lock_owner(rbd_dev))
6404                 rbd_unlock(rbd_dev);
6405         up_write(&rbd_dev->lock_rwsem);
6406         rbd_unregister_watch(rbd_dev);
6407
6408         /*
6409          * Don't free anything from rbd_dev->disk until after all
6410          * notifies are completely processed. Otherwise
6411          * rbd_bus_del_dev() will race with rbd_watch_cb(), resulting
6412          * in a potential use after free of rbd_dev->disk or rbd_dev.
6413          */
6414         rbd_dev_device_release(rbd_dev);
6415         rbd_dev_image_release(rbd_dev);
6416
6417         return count;
6418 }
6419
6420 static ssize_t rbd_remove(struct bus_type *bus,
6421                           const char *buf,
6422                           size_t count)
6423 {
6424         if (single_major)
6425                 return -EINVAL;
6426
6427         return do_rbd_remove(bus, buf, count);
6428 }
6429
6430 static ssize_t rbd_remove_single_major(struct bus_type *bus,
6431                                        const char *buf,
6432                                        size_t count)
6433 {
6434         return do_rbd_remove(bus, buf, count);
6435 }
6436
6437 /*
6438  * create control files in sysfs
6439  * /sys/bus/rbd/...
6440  */
6441 static int rbd_sysfs_init(void)
6442 {
6443         int ret;
6444
6445         ret = device_register(&rbd_root_dev);
6446         if (ret < 0)
6447                 return ret;
6448
6449         ret = bus_register(&rbd_bus_type);
6450         if (ret < 0)
6451                 device_unregister(&rbd_root_dev);
6452
6453         return ret;
6454 }
6455
6456 static void rbd_sysfs_cleanup(void)
6457 {
6458         bus_unregister(&rbd_bus_type);
6459         device_unregister(&rbd_root_dev);
6460 }
6461
6462 static int rbd_slab_init(void)
6463 {
6464         rbd_assert(!rbd_img_request_cache);
6465         rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
6466         if (!rbd_img_request_cache)
6467                 return -ENOMEM;
6468
6469         rbd_assert(!rbd_obj_request_cache);
6470         rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
6471         if (!rbd_obj_request_cache)
6472                 goto out_err;
6473
6474         rbd_assert(!rbd_segment_name_cache);
6475         rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
6476                                         CEPH_MAX_OID_NAME_LEN + 1, 1, 0, NULL);
6477         if (rbd_segment_name_cache)
6478                 return 0;
6479 out_err:
6480         kmem_cache_destroy(rbd_obj_request_cache);
6481         rbd_obj_request_cache = NULL;
6482
6483         kmem_cache_destroy(rbd_img_request_cache);
6484         rbd_img_request_cache = NULL;
6485
6486         return -ENOMEM;
6487 }
6488
6489 static void rbd_slab_exit(void)
6490 {
6491         rbd_assert(rbd_segment_name_cache);
6492         kmem_cache_destroy(rbd_segment_name_cache);
6493         rbd_segment_name_cache = NULL;
6494
6495         rbd_assert(rbd_obj_request_cache);
6496         kmem_cache_destroy(rbd_obj_request_cache);
6497         rbd_obj_request_cache = NULL;
6498
6499         rbd_assert(rbd_img_request_cache);
6500         kmem_cache_destroy(rbd_img_request_cache);
6501         rbd_img_request_cache = NULL;
6502 }
6503
6504 static int __init rbd_init(void)
6505 {
6506         int rc;
6507
6508         if (!libceph_compatible(NULL)) {
6509                 rbd_warn(NULL, "libceph incompatibility (quitting)");
6510                 return -EINVAL;
6511         }
6512
6513         rc = rbd_slab_init();
6514         if (rc)
6515                 return rc;
6516
6517         /*
6518          * The number of active work items is limited by the number of
6519          * rbd devices * queue depth, so leave @max_active at default.
6520          */
6521         rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
6522         if (!rbd_wq) {
6523                 rc = -ENOMEM;
6524                 goto err_out_slab;
6525         }
6526
6527         if (single_major) {
6528                 rbd_major = register_blkdev(0, RBD_DRV_NAME);
6529                 if (rbd_major < 0) {
6530                         rc = rbd_major;
6531                         goto err_out_wq;
6532                 }
6533         }
6534
6535         rc = rbd_sysfs_init();
6536         if (rc)
6537                 goto err_out_blkdev;
6538
6539         if (single_major)
6540                 pr_info("loaded (major %d)\n", rbd_major);
6541         else
6542                 pr_info("loaded\n");
6543
6544         return 0;
6545
6546 err_out_blkdev:
6547         if (single_major)
6548                 unregister_blkdev(rbd_major, RBD_DRV_NAME);
6549 err_out_wq:
6550         destroy_workqueue(rbd_wq);
6551 err_out_slab:
6552         rbd_slab_exit();
6553         return rc;
6554 }
6555
6556 static void __exit rbd_exit(void)
6557 {
6558         ida_destroy(&rbd_dev_id_ida);
6559         rbd_sysfs_cleanup();
6560         if (single_major)
6561                 unregister_blkdev(rbd_major, RBD_DRV_NAME);
6562         destroy_workqueue(rbd_wq);
6563         rbd_slab_exit();
6564 }
6565
6566 module_init(rbd_init);
6567 module_exit(rbd_exit);
6568
6569 MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
6570 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
6571 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
6572 /* following authorship retained from original osdblk.c */
6573 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
6574
6575 MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
6576 MODULE_LICENSE("GPL");