2 rbd.c -- Export ceph rados objects as a Linux block device
5 based on drivers/block/osdblk.c:
7 Copyright 2009 Red Hat, Inc.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; see the file COPYING. If not, write to
20 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
24 For usage instructions, please refer to:
26 Documentation/ABI/testing/sysfs-bus-rbd
30 #include <linux/ceph/libceph.h>
31 #include <linux/ceph/osd_client.h>
32 #include <linux/ceph/mon_client.h>
33 #include <linux/ceph/decode.h>
34 #include <linux/parser.h>
36 #include <linux/kernel.h>
37 #include <linux/device.h>
38 #include <linux/module.h>
40 #include <linux/blkdev.h>
42 #include "rbd_types.h"
44 #define RBD_DEBUG /* Activate rbd_assert() calls */
47 * The basic unit of block I/O is a sector. It is interpreted in a
48 * number of contexts in Linux (blk, bio, genhd), but the default is
49 * universally 512 bytes. These symbols are just slightly more
50 * meaningful than the bare numbers they represent.
52 #define SECTOR_SHIFT 9
53 #define SECTOR_SIZE (1ULL << SECTOR_SHIFT)
55 #define RBD_DRV_NAME "rbd"
56 #define RBD_DRV_NAME_LONG "rbd (rados block device)"
58 #define RBD_MINORS_PER_MAJOR 256 /* max minors per blkdev */
60 #define RBD_SNAP_DEV_NAME_PREFIX "snap_"
61 #define RBD_MAX_SNAP_NAME_LEN \
62 (NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))
64 #define RBD_MAX_SNAP_COUNT 510 /* allows max snapc to fit in 4KB */
66 #define RBD_SNAP_HEAD_NAME "-"
68 /* This allows a single page to hold an image name sent by OSD */
69 #define RBD_IMAGE_NAME_LEN_MAX (PAGE_SIZE - sizeof (__le32) - 1)
70 #define RBD_IMAGE_ID_LEN_MAX 64
72 #define RBD_OBJ_PREFIX_LEN_MAX 64
76 #define RBD_FEATURE_LAYERING (1<<0)
77 #define RBD_FEATURE_STRIPINGV2 (1<<1)
78 #define RBD_FEATURES_ALL \
79 (RBD_FEATURE_LAYERING | RBD_FEATURE_STRIPINGV2)
81 /* Features supported by this (client software) implementation. */
83 #define RBD_FEATURES_SUPPORTED (RBD_FEATURES_ALL)
86 * An RBD device name will be "rbd#", where the "rbd" comes from
87 * RBD_DRV_NAME above, and # is a unique integer identifier.
88 * MAX_INT_FORMAT_WIDTH is used in ensuring DEV_NAME_LEN is big
89 * enough to hold all possible device names.
91 #define DEV_NAME_LEN 32
92 #define MAX_INT_FORMAT_WIDTH ((5 * sizeof (int)) / 2 + 1)
95 * block device image metadata (in-memory version)
97 struct rbd_image_header {
98 /* These four fields never change for a given rbd image */
105 /* The remaining fields need to be updated occasionally */
107 struct ceph_snap_context *snapc;
118 * An rbd image specification.
120 * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
121 * identify an image. Each rbd_dev structure includes a pointer to
122 * an rbd_spec structure that encapsulates this identity.
124 * Each of the id's in an rbd_spec has an associated name. For a
125 * user-mapped image, the names are supplied and the id's associated
126 * with them are looked up. For a layered image, a parent image is
127 * defined by the tuple, and the names are looked up.
129 * An rbd_dev structure contains a parent_spec pointer which is
130 * non-null if the image it represents is a child in a layered
131 * image. This pointer will refer to the rbd_spec structure used
132 * by the parent rbd_dev for its own identity (i.e., the structure
133 * is shared between the parent and child).
135 * Since these structures are populated once, during the discovery
136 * phase of image construction, they are effectively immutable so
137 * we make no effort to synchronize access to them.
139 * Note that code herein does not assume the image name is known (it
140 * could be a null pointer).
144 const char *pool_name;
146 const char *image_id;
147 const char *image_name;
150 const char *snap_name;
156 * an instance of the client. multiple devices may share an rbd client.
159 struct ceph_client *client;
161 struct list_head node;
164 struct rbd_img_request;
165 typedef void (*rbd_img_callback_t)(struct rbd_img_request *);
167 #define BAD_WHICH U32_MAX /* Good which or bad which, which? */
169 struct rbd_obj_request;
170 typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);
172 enum obj_request_type {
173 OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
177 OBJ_REQ_DONE, /* completion flag: not done = 0, done = 1 */
178 OBJ_REQ_IMG_DATA, /* object usage: standalone = 0, image = 1 */
179 OBJ_REQ_KNOWN, /* EXISTS flag valid: no = 0, yes = 1 */
180 OBJ_REQ_EXISTS, /* target exists: no = 0, yes = 1 */
183 struct rbd_obj_request {
184 const char *object_name;
185 u64 offset; /* object start byte */
186 u64 length; /* bytes from offset */
190 * An object request associated with an image will have its
191 * img_data flag set; a standalone object request will not.
193 * A standalone object request will have which == BAD_WHICH
194 * and a null obj_request pointer.
196 * An object request initiated in support of a layered image
197 * object (to check for its existence before a write) will
198 * have which == BAD_WHICH and a non-null obj_request pointer.
200 * Finally, an object request for rbd image data will have
201 * which != BAD_WHICH, and will have a non-null img_request
202 * pointer. The value of which will be in the range
203 * 0..(img_request->obj_request_count-1).
206 struct rbd_obj_request *obj_request; /* STAT op */
208 struct rbd_img_request *img_request;
210 /* links for img_request->obj_requests list */
211 struct list_head links;
214 u32 which; /* posn image request list */
216 enum obj_request_type type;
218 struct bio *bio_list;
224 struct page **copyup_pages;
226 struct ceph_osd_request *osd_req;
228 u64 xferred; /* bytes transferred */
232 rbd_obj_callback_t callback;
233 struct completion completion;
239 IMG_REQ_WRITE, /* I/O direction: read = 0, write = 1 */
240 IMG_REQ_CHILD, /* initiator: block = 0, child image = 1 */
241 IMG_REQ_LAYERED, /* ENOENT handling: normal = 0, layered = 1 */
244 struct rbd_img_request {
245 struct rbd_device *rbd_dev;
246 u64 offset; /* starting image byte offset */
247 u64 length; /* byte count from offset */
250 u64 snap_id; /* for reads */
251 struct ceph_snap_context *snapc; /* for writes */
254 struct request *rq; /* block request */
255 struct rbd_obj_request *obj_request; /* obj req initiator */
257 struct page **copyup_pages;
258 spinlock_t completion_lock;/* protects next_completion */
260 rbd_img_callback_t callback;
261 u64 xferred;/* aggregate bytes transferred */
262 int result; /* first nonzero obj_request result */
264 u32 obj_request_count;
265 struct list_head obj_requests; /* rbd_obj_request structs */
270 #define for_each_obj_request(ireq, oreq) \
271 list_for_each_entry(oreq, &(ireq)->obj_requests, links)
272 #define for_each_obj_request_from(ireq, oreq) \
273 list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
274 #define for_each_obj_request_safe(ireq, oreq, n) \
275 list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
280 struct list_head node;
295 int dev_id; /* blkdev unique id */
297 int major; /* blkdev assigned major */
298 struct gendisk *disk; /* blkdev's gendisk and rq */
300 u32 image_format; /* Either 1 or 2 */
301 struct rbd_client *rbd_client;
303 char name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
305 spinlock_t lock; /* queue, flags, open_count */
307 struct rbd_image_header header;
308 unsigned long flags; /* possibly lock protected */
309 struct rbd_spec *spec;
313 struct ceph_file_layout layout;
315 struct ceph_osd_event *watch_event;
316 struct rbd_obj_request *watch_request;
318 struct rbd_spec *parent_spec;
320 struct rbd_device *parent;
322 /* protects updating the header */
323 struct rw_semaphore header_rwsem;
325 struct rbd_mapping mapping;
327 struct list_head node;
329 /* list of snapshots */
330 struct list_head snaps;
334 unsigned long open_count; /* protected by lock */
338 * Flag bits for rbd_dev->flags. If atomicity is required,
339 * rbd_dev->lock is used to protect access.
341 * Currently, only the "removing" flag (which is coupled with the
342 * "open_count" field) requires atomic access.
345 RBD_DEV_FLAG_EXISTS, /* mapped snapshot has not been deleted */
346 RBD_DEV_FLAG_REMOVING, /* this mapping is being removed */
349 static DEFINE_MUTEX(ctl_mutex); /* Serialize open/close/setup/teardown */
351 static LIST_HEAD(rbd_dev_list); /* devices */
352 static DEFINE_SPINLOCK(rbd_dev_list_lock);
354 static LIST_HEAD(rbd_client_list); /* clients */
355 static DEFINE_SPINLOCK(rbd_client_list_lock);
357 static int rbd_img_request_submit(struct rbd_img_request *img_request);
359 static int rbd_dev_snaps_update(struct rbd_device *rbd_dev);
361 static void rbd_dev_release(struct device *dev);
362 static void rbd_snap_destroy(struct rbd_snap *snap);
364 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
366 static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
368 static int rbd_dev_image_probe(struct rbd_device *rbd_dev);
370 static struct bus_attribute rbd_bus_attrs[] = {
371 __ATTR(add, S_IWUSR, NULL, rbd_add),
372 __ATTR(remove, S_IWUSR, NULL, rbd_remove),
376 static struct bus_type rbd_bus_type = {
378 .bus_attrs = rbd_bus_attrs,
381 static void rbd_root_dev_release(struct device *dev)
385 static struct device rbd_root_dev = {
387 .release = rbd_root_dev_release,
390 static __printf(2, 3)
391 void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
393 struct va_format vaf;
401 printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
402 else if (rbd_dev->disk)
403 printk(KERN_WARNING "%s: %s: %pV\n",
404 RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
405 else if (rbd_dev->spec && rbd_dev->spec->image_name)
406 printk(KERN_WARNING "%s: image %s: %pV\n",
407 RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
408 else if (rbd_dev->spec && rbd_dev->spec->image_id)
409 printk(KERN_WARNING "%s: id %s: %pV\n",
410 RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
412 printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
413 RBD_DRV_NAME, rbd_dev, &vaf);
418 #define rbd_assert(expr) \
419 if (unlikely(!(expr))) { \
420 printk(KERN_ERR "\nAssertion failure in %s() " \
422 "\trbd_assert(%s);\n\n", \
423 __func__, __LINE__, #expr); \
426 #else /* !RBD_DEBUG */
427 # define rbd_assert(expr) ((void) 0)
428 #endif /* !RBD_DEBUG */
430 static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
431 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
433 static int rbd_dev_refresh(struct rbd_device *rbd_dev, u64 *hver);
434 static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev, u64 *hver);
436 static int rbd_open(struct block_device *bdev, fmode_t mode)
438 struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
439 bool removing = false;
441 if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
444 spin_lock_irq(&rbd_dev->lock);
445 if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
448 rbd_dev->open_count++;
449 spin_unlock_irq(&rbd_dev->lock);
453 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
454 (void) get_device(&rbd_dev->dev);
455 set_device_ro(bdev, rbd_dev->mapping.read_only);
456 mutex_unlock(&ctl_mutex);
461 static int rbd_release(struct gendisk *disk, fmode_t mode)
463 struct rbd_device *rbd_dev = disk->private_data;
464 unsigned long open_count_before;
466 spin_lock_irq(&rbd_dev->lock);
467 open_count_before = rbd_dev->open_count--;
468 spin_unlock_irq(&rbd_dev->lock);
469 rbd_assert(open_count_before > 0);
471 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
472 put_device(&rbd_dev->dev);
473 mutex_unlock(&ctl_mutex);
478 static const struct block_device_operations rbd_bd_ops = {
479 .owner = THIS_MODULE,
481 .release = rbd_release,
485 * Initialize an rbd client instance.
488 static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
490 struct rbd_client *rbdc;
493 dout("%s:\n", __func__);
494 rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
498 kref_init(&rbdc->kref);
499 INIT_LIST_HEAD(&rbdc->node);
501 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
503 rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
504 if (IS_ERR(rbdc->client))
506 ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
508 ret = ceph_open_session(rbdc->client);
512 spin_lock(&rbd_client_list_lock);
513 list_add_tail(&rbdc->node, &rbd_client_list);
514 spin_unlock(&rbd_client_list_lock);
516 mutex_unlock(&ctl_mutex);
517 dout("%s: rbdc %p\n", __func__, rbdc);
522 ceph_destroy_client(rbdc->client);
524 mutex_unlock(&ctl_mutex);
528 ceph_destroy_options(ceph_opts);
529 dout("%s: error %d\n", __func__, ret);
534 static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
536 kref_get(&rbdc->kref);
542 * Find a ceph client with specific addr and configuration. If
543 * found, bump its reference count.
545 static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
547 struct rbd_client *client_node;
550 if (ceph_opts->flags & CEPH_OPT_NOSHARE)
553 spin_lock(&rbd_client_list_lock);
554 list_for_each_entry(client_node, &rbd_client_list, node) {
555 if (!ceph_compare_options(ceph_opts, client_node->client)) {
556 __rbd_get_client(client_node);
562 spin_unlock(&rbd_client_list_lock);
564 return found ? client_node : NULL;
574 /* string args above */
577 /* Boolean args above */
581 static match_table_t rbd_opts_tokens = {
583 /* string args above */
584 {Opt_read_only, "read_only"},
585 {Opt_read_only, "ro"}, /* Alternate spelling */
586 {Opt_read_write, "read_write"},
587 {Opt_read_write, "rw"}, /* Alternate spelling */
588 /* Boolean args above */
596 #define RBD_READ_ONLY_DEFAULT false
598 static int parse_rbd_opts_token(char *c, void *private)
600 struct rbd_options *rbd_opts = private;
601 substring_t argstr[MAX_OPT_ARGS];
602 int token, intval, ret;
604 token = match_token(c, rbd_opts_tokens, argstr);
608 if (token < Opt_last_int) {
609 ret = match_int(&argstr[0], &intval);
611 pr_err("bad mount option arg (not int) "
615 dout("got int token %d val %d\n", token, intval);
616 } else if (token > Opt_last_int && token < Opt_last_string) {
617 dout("got string token %d val %s\n", token,
619 } else if (token > Opt_last_string && token < Opt_last_bool) {
620 dout("got Boolean token %d\n", token);
622 dout("got token %d\n", token);
627 rbd_opts->read_only = true;
630 rbd_opts->read_only = false;
640 * Get a ceph client with specific addr and configuration, if one does
641 * not exist create it.
643 static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
645 struct rbd_client *rbdc;
647 rbdc = rbd_client_find(ceph_opts);
648 if (rbdc) /* using an existing client */
649 ceph_destroy_options(ceph_opts);
651 rbdc = rbd_client_create(ceph_opts);
657 * Destroy ceph client
659 * Caller must hold rbd_client_list_lock.
661 static void rbd_client_release(struct kref *kref)
663 struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);
665 dout("%s: rbdc %p\n", __func__, rbdc);
666 spin_lock(&rbd_client_list_lock);
667 list_del(&rbdc->node);
668 spin_unlock(&rbd_client_list_lock);
670 ceph_destroy_client(rbdc->client);
674 /* Caller has to fill in snapc->seq and snapc->snaps[0..snap_count-1] */
676 static struct ceph_snap_context *rbd_snap_context_create(u32 snap_count)
678 struct ceph_snap_context *snapc;
681 size = sizeof (struct ceph_snap_context);
682 size += snap_count * sizeof (snapc->snaps[0]);
683 snapc = kzalloc(size, GFP_KERNEL);
687 atomic_set(&snapc->nref, 1);
688 snapc->num_snaps = snap_count;
693 static inline void rbd_snap_context_get(struct ceph_snap_context *snapc)
695 (void)ceph_get_snap_context(snapc);
698 static inline void rbd_snap_context_put(struct ceph_snap_context *snapc)
700 ceph_put_snap_context(snapc);
704 * Drop reference to ceph client node. If it's not referenced anymore, release
707 static void rbd_put_client(struct rbd_client *rbdc)
710 kref_put(&rbdc->kref, rbd_client_release);
713 static bool rbd_image_format_valid(u32 image_format)
715 return image_format == 1 || image_format == 2;
718 static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
723 /* The header has to start with the magic rbd header text */
724 if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
727 /* The bio layer requires at least sector-sized I/O */
729 if (ondisk->options.order < SECTOR_SHIFT)
732 /* If we use u64 in a few spots we may be able to loosen this */
734 if (ondisk->options.order > 8 * sizeof (int) - 1)
738 * The size of a snapshot header has to fit in a size_t, and
739 * that limits the number of snapshots.
741 snap_count = le32_to_cpu(ondisk->snap_count);
742 size = SIZE_MAX - sizeof (struct ceph_snap_context);
743 if (snap_count > size / sizeof (__le64))
747 * Not only that, but the size of the entire the snapshot
748 * header must also be representable in a size_t.
750 size -= snap_count * sizeof (__le64);
751 if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
758 * Create a new header structure, translate header format from the on-disk
761 static int rbd_header_from_disk(struct rbd_image_header *header,
762 struct rbd_image_header_ondisk *ondisk)
769 memset(header, 0, sizeof (*header));
771 snap_count = le32_to_cpu(ondisk->snap_count);
773 len = strnlen(ondisk->object_prefix, sizeof (ondisk->object_prefix));
774 header->object_prefix = kmalloc(len + 1, GFP_KERNEL);
775 if (!header->object_prefix)
777 memcpy(header->object_prefix, ondisk->object_prefix, len);
778 header->object_prefix[len] = '\0';
781 u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
783 /* Save a copy of the snapshot names */
785 if (snap_names_len > (u64) SIZE_MAX)
787 header->snap_names = kmalloc(snap_names_len, GFP_KERNEL);
788 if (!header->snap_names)
791 * Note that rbd_dev_v1_header_read() guarantees
792 * the ondisk buffer we're working with has
793 * snap_names_len bytes beyond the end of the
794 * snapshot id array, this memcpy() is safe.
796 memcpy(header->snap_names, &ondisk->snaps[snap_count],
799 /* Record each snapshot's size */
801 size = snap_count * sizeof (*header->snap_sizes);
802 header->snap_sizes = kmalloc(size, GFP_KERNEL);
803 if (!header->snap_sizes)
805 for (i = 0; i < snap_count; i++)
806 header->snap_sizes[i] =
807 le64_to_cpu(ondisk->snaps[i].image_size);
809 header->snap_names = NULL;
810 header->snap_sizes = NULL;
813 header->features = 0; /* No features support in v1 images */
814 header->obj_order = ondisk->options.order;
815 header->crypt_type = ondisk->options.crypt_type;
816 header->comp_type = ondisk->options.comp_type;
818 /* Allocate and fill in the snapshot context */
820 header->image_size = le64_to_cpu(ondisk->image_size);
822 header->snapc = rbd_snap_context_create(snap_count);
825 header->snapc->seq = le64_to_cpu(ondisk->snap_seq);
826 for (i = 0; i < snap_count; i++)
827 header->snapc->snaps[i] = le64_to_cpu(ondisk->snaps[i].id);
832 kfree(header->snap_sizes);
833 header->snap_sizes = NULL;
834 kfree(header->snap_names);
835 header->snap_names = NULL;
836 kfree(header->object_prefix);
837 header->object_prefix = NULL;
842 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
844 struct rbd_snap *snap;
846 if (snap_id == CEPH_NOSNAP)
847 return RBD_SNAP_HEAD_NAME;
849 list_for_each_entry(snap, &rbd_dev->snaps, node)
850 if (snap_id == snap->id)
856 static struct rbd_snap *snap_by_name(struct rbd_device *rbd_dev,
857 const char *snap_name)
859 struct rbd_snap *snap;
861 list_for_each_entry(snap, &rbd_dev->snaps, node)
862 if (!strcmp(snap_name, snap->name))
868 static int rbd_dev_set_mapping(struct rbd_device *rbd_dev)
870 if (!memcmp(rbd_dev->spec->snap_name, RBD_SNAP_HEAD_NAME,
871 sizeof (RBD_SNAP_HEAD_NAME))) {
872 rbd_dev->mapping.size = rbd_dev->header.image_size;
873 rbd_dev->mapping.features = rbd_dev->header.features;
875 struct rbd_snap *snap;
877 snap = snap_by_name(rbd_dev, rbd_dev->spec->snap_name);
880 rbd_dev->mapping.size = snap->size;
881 rbd_dev->mapping.features = snap->features;
882 rbd_dev->mapping.read_only = true;
888 static void rbd_header_free(struct rbd_image_header *header)
890 kfree(header->object_prefix);
891 header->object_prefix = NULL;
892 kfree(header->snap_sizes);
893 header->snap_sizes = NULL;
894 kfree(header->snap_names);
895 header->snap_names = NULL;
896 rbd_snap_context_put(header->snapc);
897 header->snapc = NULL;
900 static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
906 name = kmalloc(MAX_OBJ_NAME_SIZE + 1, GFP_NOIO);
909 segment = offset >> rbd_dev->header.obj_order;
910 ret = snprintf(name, MAX_OBJ_NAME_SIZE + 1, "%s.%012llx",
911 rbd_dev->header.object_prefix, segment);
912 if (ret < 0 || ret > MAX_OBJ_NAME_SIZE) {
913 pr_err("error formatting segment name for #%llu (%d)\n",
922 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
924 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
926 return offset & (segment_size - 1);
929 static u64 rbd_segment_length(struct rbd_device *rbd_dev,
930 u64 offset, u64 length)
932 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
934 offset &= segment_size - 1;
936 rbd_assert(length <= U64_MAX - offset);
937 if (offset + length > segment_size)
938 length = segment_size - offset;
944 * returns the size of an object in the image
946 static u64 rbd_obj_bytes(struct rbd_image_header *header)
948 return 1 << header->obj_order;
955 static void bio_chain_put(struct bio *chain)
961 chain = chain->bi_next;
967 * zeros a bio chain, starting at specific offset
969 static void zero_bio_chain(struct bio *chain, int start_ofs)
978 bio_for_each_segment(bv, chain, i) {
979 if (pos + bv->bv_len > start_ofs) {
980 int remainder = max(start_ofs - pos, 0);
981 buf = bvec_kmap_irq(bv, &flags);
982 memset(buf + remainder, 0,
983 bv->bv_len - remainder);
984 bvec_kunmap_irq(buf, &flags);
989 chain = chain->bi_next;
994 * similar to zero_bio_chain(), zeros data defined by a page array,
995 * starting at the given byte offset from the start of the array and
996 * continuing up to the given end offset. The pages array is
997 * assumed to be big enough to hold all bytes up to the end.
999 static void zero_pages(struct page **pages, u64 offset, u64 end)
1001 struct page **page = &pages[offset >> PAGE_SHIFT];
1003 rbd_assert(end > offset);
1004 rbd_assert(end - offset <= (u64)SIZE_MAX);
1005 while (offset < end) {
1008 unsigned long flags;
1011 page_offset = (size_t)(offset & ~PAGE_MASK);
1012 length = min(PAGE_SIZE - page_offset, (size_t)(end - offset));
1013 local_irq_save(flags);
1014 kaddr = kmap_atomic(*page);
1015 memset(kaddr + page_offset, 0, length);
1016 kunmap_atomic(kaddr);
1017 local_irq_restore(flags);
1025 * Clone a portion of a bio, starting at the given byte offset
1026 * and continuing for the number of bytes indicated.
1028 static struct bio *bio_clone_range(struct bio *bio_src,
1029 unsigned int offset,
1037 unsigned short end_idx;
1038 unsigned short vcnt;
1041 /* Handle the easy case for the caller */
1043 if (!offset && len == bio_src->bi_size)
1044 return bio_clone(bio_src, gfpmask);
1046 if (WARN_ON_ONCE(!len))
1048 if (WARN_ON_ONCE(len > bio_src->bi_size))
1050 if (WARN_ON_ONCE(offset > bio_src->bi_size - len))
1053 /* Find first affected segment... */
1056 __bio_for_each_segment(bv, bio_src, idx, 0) {
1057 if (resid < bv->bv_len)
1059 resid -= bv->bv_len;
1063 /* ...and the last affected segment */
1066 __bio_for_each_segment(bv, bio_src, end_idx, idx) {
1067 if (resid <= bv->bv_len)
1069 resid -= bv->bv_len;
1071 vcnt = end_idx - idx + 1;
1073 /* Build the clone */
1075 bio = bio_alloc(gfpmask, (unsigned int) vcnt);
1077 return NULL; /* ENOMEM */
1079 bio->bi_bdev = bio_src->bi_bdev;
1080 bio->bi_sector = bio_src->bi_sector + (offset >> SECTOR_SHIFT);
1081 bio->bi_rw = bio_src->bi_rw;
1082 bio->bi_flags |= 1 << BIO_CLONED;
1085 * Copy over our part of the bio_vec, then update the first
1086 * and last (or only) entries.
1088 memcpy(&bio->bi_io_vec[0], &bio_src->bi_io_vec[idx],
1089 vcnt * sizeof (struct bio_vec));
1090 bio->bi_io_vec[0].bv_offset += voff;
1092 bio->bi_io_vec[0].bv_len -= voff;
1093 bio->bi_io_vec[vcnt - 1].bv_len = resid;
1095 bio->bi_io_vec[0].bv_len = len;
1098 bio->bi_vcnt = vcnt;
1106 * Clone a portion of a bio chain, starting at the given byte offset
1107 * into the first bio in the source chain and continuing for the
1108 * number of bytes indicated. The result is another bio chain of
1109 * exactly the given length, or a null pointer on error.
1111 * The bio_src and offset parameters are both in-out. On entry they
1112 * refer to the first source bio and the offset into that bio where
1113 * the start of data to be cloned is located.
1115 * On return, bio_src is updated to refer to the bio in the source
1116 * chain that contains first un-cloned byte, and *offset will
1117 * contain the offset of that byte within that bio.
1119 static struct bio *bio_chain_clone_range(struct bio **bio_src,
1120 unsigned int *offset,
1124 struct bio *bi = *bio_src;
1125 unsigned int off = *offset;
1126 struct bio *chain = NULL;
1129 /* Build up a chain of clone bios up to the limit */
1131 if (!bi || off >= bi->bi_size || !len)
1132 return NULL; /* Nothing to clone */
1136 unsigned int bi_size;
1140 rbd_warn(NULL, "bio_chain exhausted with %u left", len);
1141 goto out_err; /* EINVAL; ran out of bio's */
1143 bi_size = min_t(unsigned int, bi->bi_size - off, len);
1144 bio = bio_clone_range(bi, off, bi_size, gfpmask);
1146 goto out_err; /* ENOMEM */
1149 end = &bio->bi_next;
1152 if (off == bi->bi_size) {
1163 bio_chain_put(chain);
1169 * The default/initial value for all object request flags is 0. For
1170 * each flag, once its value is set to 1 it is never reset to 0
1173 static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1175 if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1176 struct rbd_device *rbd_dev;
1178 rbd_dev = obj_request->img_request->rbd_dev;
1179 rbd_warn(rbd_dev, "obj_request %p already marked img_data\n",
1184 static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1187 return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1190 static void obj_request_done_set(struct rbd_obj_request *obj_request)
1192 if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
1193 struct rbd_device *rbd_dev = NULL;
1195 if (obj_request_img_data_test(obj_request))
1196 rbd_dev = obj_request->img_request->rbd_dev;
1197 rbd_warn(rbd_dev, "obj_request %p already marked done\n",
1202 static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1205 return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1209 * This sets the KNOWN flag after (possibly) setting the EXISTS
1210 * flag. The latter is set based on the "exists" value provided.
1212 * Note that for our purposes once an object exists it never goes
1213 * away again. It's possible that the response from two existence
1214 * checks are separated by the creation of the target object, and
1215 * the first ("doesn't exist") response arrives *after* the second
1216 * ("does exist"). In that case we ignore the second one.
1218 static void obj_request_existence_set(struct rbd_obj_request *obj_request,
1222 set_bit(OBJ_REQ_EXISTS, &obj_request->flags);
1223 set_bit(OBJ_REQ_KNOWN, &obj_request->flags);
1227 static bool obj_request_known_test(struct rbd_obj_request *obj_request)
1230 return test_bit(OBJ_REQ_KNOWN, &obj_request->flags) != 0;
1233 static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
1236 return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
1239 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
1241 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1242 atomic_read(&obj_request->kref.refcount));
1243 kref_get(&obj_request->kref);
1246 static void rbd_obj_request_destroy(struct kref *kref);
1247 static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
1249 rbd_assert(obj_request != NULL);
1250 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1251 atomic_read(&obj_request->kref.refcount));
1252 kref_put(&obj_request->kref, rbd_obj_request_destroy);
1255 static void rbd_img_request_get(struct rbd_img_request *img_request)
1257 dout("%s: img %p (was %d)\n", __func__, img_request,
1258 atomic_read(&img_request->kref.refcount));
1259 kref_get(&img_request->kref);
1262 static void rbd_img_request_destroy(struct kref *kref);
1263 static void rbd_img_request_put(struct rbd_img_request *img_request)
1265 rbd_assert(img_request != NULL);
1266 dout("%s: img %p (was %d)\n", __func__, img_request,
1267 atomic_read(&img_request->kref.refcount));
1268 kref_put(&img_request->kref, rbd_img_request_destroy);
1271 static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
1272 struct rbd_obj_request *obj_request)
1274 rbd_assert(obj_request->img_request == NULL);
1276 /* Image request now owns object's original reference */
1277 obj_request->img_request = img_request;
1278 obj_request->which = img_request->obj_request_count;
1279 rbd_assert(!obj_request_img_data_test(obj_request));
1280 obj_request_img_data_set(obj_request);
1281 rbd_assert(obj_request->which != BAD_WHICH);
1282 img_request->obj_request_count++;
1283 list_add_tail(&obj_request->links, &img_request->obj_requests);
1284 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1285 obj_request->which);
1288 static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
1289 struct rbd_obj_request *obj_request)
1291 rbd_assert(obj_request->which != BAD_WHICH);
1293 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1294 obj_request->which);
1295 list_del(&obj_request->links);
1296 rbd_assert(img_request->obj_request_count > 0);
1297 img_request->obj_request_count--;
1298 rbd_assert(obj_request->which == img_request->obj_request_count);
1299 obj_request->which = BAD_WHICH;
1300 rbd_assert(obj_request_img_data_test(obj_request));
1301 rbd_assert(obj_request->img_request == img_request);
1302 obj_request->img_request = NULL;
1303 obj_request->callback = NULL;
1304 rbd_obj_request_put(obj_request);
1307 static bool obj_request_type_valid(enum obj_request_type type)
1310 case OBJ_REQUEST_NODATA:
1311 case OBJ_REQUEST_BIO:
1312 case OBJ_REQUEST_PAGES:
1319 static int rbd_obj_request_submit(struct ceph_osd_client *osdc,
1320 struct rbd_obj_request *obj_request)
1322 dout("%s: osdc %p obj %p\n", __func__, osdc, obj_request);
1324 return ceph_osdc_start_request(osdc, obj_request->osd_req, false);
1327 static void rbd_img_request_complete(struct rbd_img_request *img_request)
1330 dout("%s: img %p\n", __func__, img_request);
1333 * If no error occurred, compute the aggregate transfer
1334 * count for the image request. We could instead use
1335 * atomic64_cmpxchg() to update it as each object request
1336 * completes; not clear which way is better off hand.
1338 if (!img_request->result) {
1339 struct rbd_obj_request *obj_request;
1342 for_each_obj_request(img_request, obj_request)
1343 xferred += obj_request->xferred;
1344 img_request->xferred = xferred;
1347 if (img_request->callback)
1348 img_request->callback(img_request);
1350 rbd_img_request_put(img_request);
1353 /* Caller is responsible for rbd_obj_request_destroy(obj_request) */
1355 static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
1357 dout("%s: obj %p\n", __func__, obj_request);
1359 return wait_for_completion_interruptible(&obj_request->completion);
1363 * The default/initial value for all image request flags is 0. Each
1364 * is conditionally set to 1 at image request initialization time
1365 * and currently never change thereafter.
1367 static void img_request_write_set(struct rbd_img_request *img_request)
1369 set_bit(IMG_REQ_WRITE, &img_request->flags);
1373 static bool img_request_write_test(struct rbd_img_request *img_request)
1376 return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;
1379 static void img_request_child_set(struct rbd_img_request *img_request)
1381 set_bit(IMG_REQ_CHILD, &img_request->flags);
1385 static bool img_request_child_test(struct rbd_img_request *img_request)
1388 return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
1391 static void img_request_layered_set(struct rbd_img_request *img_request)
1393 set_bit(IMG_REQ_LAYERED, &img_request->flags);
1397 static bool img_request_layered_test(struct rbd_img_request *img_request)
1400 return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
1404 rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
1406 u64 xferred = obj_request->xferred;
1407 u64 length = obj_request->length;
1409 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1410 obj_request, obj_request->img_request, obj_request->result,
1413 * ENOENT means a hole in the image. We zero-fill the
1414 * entire length of the request. A short read also implies
1415 * zero-fill to the end of the request. Either way we
1416 * update the xferred count to indicate the whole request
1419 rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1420 if (obj_request->result == -ENOENT) {
1421 if (obj_request->type == OBJ_REQUEST_BIO)
1422 zero_bio_chain(obj_request->bio_list, 0);
1424 zero_pages(obj_request->pages, 0, length);
1425 obj_request->result = 0;
1426 obj_request->xferred = length;
1427 } else if (xferred < length && !obj_request->result) {
1428 if (obj_request->type == OBJ_REQUEST_BIO)
1429 zero_bio_chain(obj_request->bio_list, xferred);
1431 zero_pages(obj_request->pages, xferred, length);
1432 obj_request->xferred = length;
1434 obj_request_done_set(obj_request);
1437 static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
1439 dout("%s: obj %p cb %p\n", __func__, obj_request,
1440 obj_request->callback);
1441 if (obj_request->callback)
1442 obj_request->callback(obj_request);
1444 complete_all(&obj_request->completion);
1447 static void rbd_osd_trivial_callback(struct rbd_obj_request *obj_request)
1449 dout("%s: obj %p\n", __func__, obj_request);
1450 obj_request_done_set(obj_request);
1453 static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
1455 struct rbd_img_request *img_request = NULL;
1456 struct rbd_device *rbd_dev = NULL;
1457 bool layered = false;
1459 if (obj_request_img_data_test(obj_request)) {
1460 img_request = obj_request->img_request;
1461 layered = img_request && img_request_layered_test(img_request);
1462 rbd_dev = img_request->rbd_dev;
1465 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1466 obj_request, img_request, obj_request->result,
1467 obj_request->xferred, obj_request->length);
1468 if (layered && obj_request->result == -ENOENT &&
1469 obj_request->img_offset < rbd_dev->parent_overlap)
1470 rbd_img_parent_read(obj_request);
1471 else if (img_request)
1472 rbd_img_obj_request_read_callback(obj_request);
1474 obj_request_done_set(obj_request);
1477 static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
1479 dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1480 obj_request->result, obj_request->length);
1482 * There is no such thing as a successful short write. Set
1483 * it to our originally-requested length.
1485 obj_request->xferred = obj_request->length;
1486 obj_request_done_set(obj_request);
1490 * For a simple stat call there's nothing to do. We'll do more if
1491 * this is part of a write sequence for a layered image.
1493 static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
1495 dout("%s: obj %p\n", __func__, obj_request);
1496 obj_request_done_set(obj_request);
1499 static void rbd_osd_req_callback(struct ceph_osd_request *osd_req,
1500 struct ceph_msg *msg)
1502 struct rbd_obj_request *obj_request = osd_req->r_priv;
1505 dout("%s: osd_req %p msg %p\n", __func__, osd_req, msg);
1506 rbd_assert(osd_req == obj_request->osd_req);
1507 if (obj_request_img_data_test(obj_request)) {
1508 rbd_assert(obj_request->img_request);
1509 rbd_assert(obj_request->which != BAD_WHICH);
1511 rbd_assert(obj_request->which == BAD_WHICH);
1514 if (osd_req->r_result < 0)
1515 obj_request->result = osd_req->r_result;
1516 obj_request->version = le64_to_cpu(osd_req->r_reassert_version.version);
1518 BUG_ON(osd_req->r_num_ops > 2);
1521 * We support a 64-bit length, but ultimately it has to be
1522 * passed to blk_end_request(), which takes an unsigned int.
1524 obj_request->xferred = osd_req->r_reply_op_len[0];
1525 rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1526 opcode = osd_req->r_ops[0].op;
1528 case CEPH_OSD_OP_READ:
1529 rbd_osd_read_callback(obj_request);
1531 case CEPH_OSD_OP_WRITE:
1532 rbd_osd_write_callback(obj_request);
1534 case CEPH_OSD_OP_STAT:
1535 rbd_osd_stat_callback(obj_request);
1537 case CEPH_OSD_OP_CALL:
1538 case CEPH_OSD_OP_NOTIFY_ACK:
1539 case CEPH_OSD_OP_WATCH:
1540 rbd_osd_trivial_callback(obj_request);
1543 rbd_warn(NULL, "%s: unsupported op %hu\n",
1544 obj_request->object_name, (unsigned short) opcode);
1548 if (obj_request_done_test(obj_request))
1549 rbd_obj_request_complete(obj_request);
1552 static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
1554 struct rbd_img_request *img_request = obj_request->img_request;
1555 struct ceph_osd_request *osd_req = obj_request->osd_req;
1558 rbd_assert(osd_req != NULL);
1560 snap_id = img_request ? img_request->snap_id : CEPH_NOSNAP;
1561 ceph_osdc_build_request(osd_req, obj_request->offset,
1562 NULL, snap_id, NULL);
1565 static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
1567 struct rbd_img_request *img_request = obj_request->img_request;
1568 struct ceph_osd_request *osd_req = obj_request->osd_req;
1569 struct ceph_snap_context *snapc;
1570 struct timespec mtime = CURRENT_TIME;
1572 rbd_assert(osd_req != NULL);
1574 snapc = img_request ? img_request->snapc : NULL;
1575 ceph_osdc_build_request(osd_req, obj_request->offset,
1576 snapc, CEPH_NOSNAP, &mtime);
1579 static struct ceph_osd_request *rbd_osd_req_create(
1580 struct rbd_device *rbd_dev,
1582 struct rbd_obj_request *obj_request)
1584 struct ceph_snap_context *snapc = NULL;
1585 struct ceph_osd_client *osdc;
1586 struct ceph_osd_request *osd_req;
1588 if (obj_request_img_data_test(obj_request)) {
1589 struct rbd_img_request *img_request = obj_request->img_request;
1591 rbd_assert(write_request ==
1592 img_request_write_test(img_request));
1594 snapc = img_request->snapc;
1597 /* Allocate and initialize the request, for the single op */
1599 osdc = &rbd_dev->rbd_client->client->osdc;
1600 osd_req = ceph_osdc_alloc_request(osdc, snapc, 1, false, GFP_ATOMIC);
1602 return NULL; /* ENOMEM */
1605 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1607 osd_req->r_flags = CEPH_OSD_FLAG_READ;
1609 osd_req->r_callback = rbd_osd_req_callback;
1610 osd_req->r_priv = obj_request;
1612 osd_req->r_oid_len = strlen(obj_request->object_name);
1613 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1614 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1616 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1622 * Create a copyup osd request based on the information in the
1623 * object request supplied. A copyup request has two osd ops,
1624 * a copyup method call, and a "normal" write request.
1626 static struct ceph_osd_request *
1627 rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
1629 struct rbd_img_request *img_request;
1630 struct ceph_snap_context *snapc;
1631 struct rbd_device *rbd_dev;
1632 struct ceph_osd_client *osdc;
1633 struct ceph_osd_request *osd_req;
1635 rbd_assert(obj_request_img_data_test(obj_request));
1636 img_request = obj_request->img_request;
1637 rbd_assert(img_request);
1638 rbd_assert(img_request_write_test(img_request));
1640 /* Allocate and initialize the request, for the two ops */
1642 snapc = img_request->snapc;
1643 rbd_dev = img_request->rbd_dev;
1644 osdc = &rbd_dev->rbd_client->client->osdc;
1645 osd_req = ceph_osdc_alloc_request(osdc, snapc, 2, false, GFP_ATOMIC);
1647 return NULL; /* ENOMEM */
1649 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1650 osd_req->r_callback = rbd_osd_req_callback;
1651 osd_req->r_priv = obj_request;
1653 osd_req->r_oid_len = strlen(obj_request->object_name);
1654 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1655 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1657 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1663 static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
1665 ceph_osdc_put_request(osd_req);
1668 /* object_name is assumed to be a non-null pointer and NUL-terminated */
1670 static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
1671 u64 offset, u64 length,
1672 enum obj_request_type type)
1674 struct rbd_obj_request *obj_request;
1678 rbd_assert(obj_request_type_valid(type));
1680 size = strlen(object_name) + 1;
1681 obj_request = kzalloc(sizeof (*obj_request) + size, GFP_KERNEL);
1685 name = (char *)(obj_request + 1);
1686 obj_request->object_name = memcpy(name, object_name, size);
1687 obj_request->offset = offset;
1688 obj_request->length = length;
1689 obj_request->flags = 0;
1690 obj_request->which = BAD_WHICH;
1691 obj_request->type = type;
1692 INIT_LIST_HEAD(&obj_request->links);
1693 init_completion(&obj_request->completion);
1694 kref_init(&obj_request->kref);
1696 dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
1697 offset, length, (int)type, obj_request);
1702 static void rbd_obj_request_destroy(struct kref *kref)
1704 struct rbd_obj_request *obj_request;
1706 obj_request = container_of(kref, struct rbd_obj_request, kref);
1708 dout("%s: obj %p\n", __func__, obj_request);
1710 rbd_assert(obj_request->img_request == NULL);
1711 rbd_assert(obj_request->which == BAD_WHICH);
1713 if (obj_request->osd_req)
1714 rbd_osd_req_destroy(obj_request->osd_req);
1716 rbd_assert(obj_request_type_valid(obj_request->type));
1717 switch (obj_request->type) {
1718 case OBJ_REQUEST_NODATA:
1719 break; /* Nothing to do */
1720 case OBJ_REQUEST_BIO:
1721 if (obj_request->bio_list)
1722 bio_chain_put(obj_request->bio_list);
1724 case OBJ_REQUEST_PAGES:
1725 if (obj_request->pages)
1726 ceph_release_page_vector(obj_request->pages,
1727 obj_request->page_count);
1735 * Caller is responsible for filling in the list of object requests
1736 * that comprises the image request, and the Linux request pointer
1737 * (if there is one).
1739 static struct rbd_img_request *rbd_img_request_create(
1740 struct rbd_device *rbd_dev,
1741 u64 offset, u64 length,
1745 struct rbd_img_request *img_request;
1747 img_request = kmalloc(sizeof (*img_request), GFP_ATOMIC);
1751 if (write_request) {
1752 down_read(&rbd_dev->header_rwsem);
1753 rbd_snap_context_get(rbd_dev->header.snapc);
1754 up_read(&rbd_dev->header_rwsem);
1757 img_request->rq = NULL;
1758 img_request->rbd_dev = rbd_dev;
1759 img_request->offset = offset;
1760 img_request->length = length;
1761 img_request->flags = 0;
1762 if (write_request) {
1763 img_request_write_set(img_request);
1764 img_request->snapc = rbd_dev->header.snapc;
1766 img_request->snap_id = rbd_dev->spec->snap_id;
1769 img_request_child_set(img_request);
1770 if (rbd_dev->parent_spec)
1771 img_request_layered_set(img_request);
1772 spin_lock_init(&img_request->completion_lock);
1773 img_request->next_completion = 0;
1774 img_request->callback = NULL;
1775 img_request->result = 0;
1776 img_request->obj_request_count = 0;
1777 INIT_LIST_HEAD(&img_request->obj_requests);
1778 kref_init(&img_request->kref);
1780 rbd_img_request_get(img_request); /* Avoid a warning */
1781 rbd_img_request_put(img_request); /* TEMPORARY */
1783 dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
1784 write_request ? "write" : "read", offset, length,
1790 static void rbd_img_request_destroy(struct kref *kref)
1792 struct rbd_img_request *img_request;
1793 struct rbd_obj_request *obj_request;
1794 struct rbd_obj_request *next_obj_request;
1796 img_request = container_of(kref, struct rbd_img_request, kref);
1798 dout("%s: img %p\n", __func__, img_request);
1800 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
1801 rbd_img_obj_request_del(img_request, obj_request);
1802 rbd_assert(img_request->obj_request_count == 0);
1804 if (img_request_write_test(img_request))
1805 rbd_snap_context_put(img_request->snapc);
1807 if (img_request_child_test(img_request))
1808 rbd_obj_request_put(img_request->obj_request);
1813 static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
1815 struct rbd_img_request *img_request;
1816 unsigned int xferred;
1820 rbd_assert(obj_request_img_data_test(obj_request));
1821 img_request = obj_request->img_request;
1823 rbd_assert(obj_request->xferred <= (u64)UINT_MAX);
1824 xferred = (unsigned int)obj_request->xferred;
1825 result = obj_request->result;
1827 struct rbd_device *rbd_dev = img_request->rbd_dev;
1829 rbd_warn(rbd_dev, "%s %llx at %llx (%llx)\n",
1830 img_request_write_test(img_request) ? "write" : "read",
1831 obj_request->length, obj_request->img_offset,
1832 obj_request->offset);
1833 rbd_warn(rbd_dev, " result %d xferred %x\n",
1835 if (!img_request->result)
1836 img_request->result = result;
1839 /* Image object requests don't own their page array */
1841 if (obj_request->type == OBJ_REQUEST_PAGES) {
1842 obj_request->pages = NULL;
1843 obj_request->page_count = 0;
1846 if (img_request_child_test(img_request)) {
1847 rbd_assert(img_request->obj_request != NULL);
1848 more = obj_request->which < img_request->obj_request_count - 1;
1850 rbd_assert(img_request->rq != NULL);
1851 more = blk_end_request(img_request->rq, result, xferred);
1857 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
1859 struct rbd_img_request *img_request;
1860 u32 which = obj_request->which;
1863 rbd_assert(obj_request_img_data_test(obj_request));
1864 img_request = obj_request->img_request;
1866 dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
1867 rbd_assert(img_request != NULL);
1868 rbd_assert(img_request->obj_request_count > 0);
1869 rbd_assert(which != BAD_WHICH);
1870 rbd_assert(which < img_request->obj_request_count);
1871 rbd_assert(which >= img_request->next_completion);
1873 spin_lock_irq(&img_request->completion_lock);
1874 if (which != img_request->next_completion)
1877 for_each_obj_request_from(img_request, obj_request) {
1879 rbd_assert(which < img_request->obj_request_count);
1881 if (!obj_request_done_test(obj_request))
1883 more = rbd_img_obj_end_request(obj_request);
1887 rbd_assert(more ^ (which == img_request->obj_request_count));
1888 img_request->next_completion = which;
1890 spin_unlock_irq(&img_request->completion_lock);
1893 rbd_img_request_complete(img_request);
1897 * Split up an image request into one or more object requests, each
1898 * to a different object. The "type" parameter indicates whether
1899 * "data_desc" is the pointer to the head of a list of bio
1900 * structures, or the base of a page array. In either case this
1901 * function assumes data_desc describes memory sufficient to hold
1902 * all data described by the image request.
1904 static int rbd_img_request_fill(struct rbd_img_request *img_request,
1905 enum obj_request_type type,
1908 struct rbd_device *rbd_dev = img_request->rbd_dev;
1909 struct rbd_obj_request *obj_request = NULL;
1910 struct rbd_obj_request *next_obj_request;
1911 bool write_request = img_request_write_test(img_request);
1912 struct bio *bio_list;
1913 unsigned int bio_offset = 0;
1914 struct page **pages;
1919 dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
1920 (int)type, data_desc);
1922 opcode = write_request ? CEPH_OSD_OP_WRITE : CEPH_OSD_OP_READ;
1923 img_offset = img_request->offset;
1924 resid = img_request->length;
1925 rbd_assert(resid > 0);
1927 if (type == OBJ_REQUEST_BIO) {
1928 bio_list = data_desc;
1929 rbd_assert(img_offset == bio_list->bi_sector << SECTOR_SHIFT);
1931 rbd_assert(type == OBJ_REQUEST_PAGES);
1936 struct ceph_osd_request *osd_req;
1937 const char *object_name;
1941 object_name = rbd_segment_name(rbd_dev, img_offset);
1944 offset = rbd_segment_offset(rbd_dev, img_offset);
1945 length = rbd_segment_length(rbd_dev, img_offset, resid);
1946 obj_request = rbd_obj_request_create(object_name,
1947 offset, length, type);
1948 kfree(object_name); /* object request has its own copy */
1952 if (type == OBJ_REQUEST_BIO) {
1953 unsigned int clone_size;
1955 rbd_assert(length <= (u64)UINT_MAX);
1956 clone_size = (unsigned int)length;
1957 obj_request->bio_list =
1958 bio_chain_clone_range(&bio_list,
1962 if (!obj_request->bio_list)
1965 unsigned int page_count;
1967 obj_request->pages = pages;
1968 page_count = (u32)calc_pages_for(offset, length);
1969 obj_request->page_count = page_count;
1970 if ((offset + length) & ~PAGE_MASK)
1971 page_count--; /* more on last page */
1972 pages += page_count;
1975 osd_req = rbd_osd_req_create(rbd_dev, write_request,
1979 obj_request->osd_req = osd_req;
1980 obj_request->callback = rbd_img_obj_callback;
1982 osd_req_op_extent_init(osd_req, 0, opcode, offset, length,
1984 if (type == OBJ_REQUEST_BIO)
1985 osd_req_op_extent_osd_data_bio(osd_req, 0,
1986 obj_request->bio_list, length);
1988 osd_req_op_extent_osd_data_pages(osd_req, 0,
1989 obj_request->pages, length,
1990 offset & ~PAGE_MASK, false, false);
1993 rbd_osd_req_format_write(obj_request);
1995 rbd_osd_req_format_read(obj_request);
1997 obj_request->img_offset = img_offset;
1998 rbd_img_obj_request_add(img_request, obj_request);
2000 img_offset += length;
2007 rbd_obj_request_put(obj_request);
2009 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2010 rbd_obj_request_put(obj_request);
2016 rbd_img_obj_copyup_callback(struct rbd_obj_request *obj_request)
2018 struct rbd_img_request *img_request;
2019 struct rbd_device *rbd_dev;
2023 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2024 rbd_assert(obj_request_img_data_test(obj_request));
2025 img_request = obj_request->img_request;
2026 rbd_assert(img_request);
2028 rbd_dev = img_request->rbd_dev;
2029 rbd_assert(rbd_dev);
2030 length = (u64)1 << rbd_dev->header.obj_order;
2031 page_count = (u32)calc_pages_for(0, length);
2033 rbd_assert(obj_request->copyup_pages);
2034 ceph_release_page_vector(obj_request->copyup_pages, page_count);
2035 obj_request->copyup_pages = NULL;
2038 * We want the transfer count to reflect the size of the
2039 * original write request. There is no such thing as a
2040 * successful short write, so if the request was successful
2041 * we can just set it to the originally-requested length.
2043 if (!obj_request->result)
2044 obj_request->xferred = obj_request->length;
2046 /* Finish up with the normal image object callback */
2048 rbd_img_obj_callback(obj_request);
2052 rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
2054 struct rbd_obj_request *orig_request;
2055 struct ceph_osd_request *osd_req;
2056 struct ceph_osd_client *osdc;
2057 struct rbd_device *rbd_dev;
2058 struct page **pages;
2063 rbd_assert(img_request_child_test(img_request));
2065 /* First get what we need from the image request */
2067 pages = img_request->copyup_pages;
2068 rbd_assert(pages != NULL);
2069 img_request->copyup_pages = NULL;
2071 orig_request = img_request->obj_request;
2072 rbd_assert(orig_request != NULL);
2073 rbd_assert(orig_request->type == OBJ_REQUEST_BIO);
2074 result = img_request->result;
2075 obj_size = img_request->length;
2076 xferred = img_request->xferred;
2078 rbd_dev = img_request->rbd_dev;
2079 rbd_assert(rbd_dev);
2080 rbd_assert(obj_size == (u64)1 << rbd_dev->header.obj_order);
2082 rbd_img_request_put(img_request);
2087 /* Allocate the new copyup osd request for the original request */
2090 rbd_assert(!orig_request->osd_req);
2091 osd_req = rbd_osd_req_create_copyup(orig_request);
2094 orig_request->osd_req = osd_req;
2095 orig_request->copyup_pages = pages;
2097 /* Initialize the copyup op */
2099 osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2100 osd_req_op_cls_request_data_pages(osd_req, 0, pages, obj_size, 0,
2103 /* Then the original write request op */
2105 osd_req_op_extent_init(osd_req, 1, CEPH_OSD_OP_WRITE,
2106 orig_request->offset,
2107 orig_request->length, 0, 0);
2108 osd_req_op_extent_osd_data_bio(osd_req, 1, orig_request->bio_list,
2109 orig_request->length);
2111 rbd_osd_req_format_write(orig_request);
2113 /* All set, send it off. */
2115 orig_request->callback = rbd_img_obj_copyup_callback;
2116 osdc = &rbd_dev->rbd_client->client->osdc;
2117 result = rbd_obj_request_submit(osdc, orig_request);
2121 /* Record the error code and complete the request */
2123 orig_request->result = result;
2124 orig_request->xferred = 0;
2125 obj_request_done_set(orig_request);
2126 rbd_obj_request_complete(orig_request);
2130 * Read from the parent image the range of data that covers the
2131 * entire target of the given object request. This is used for
2132 * satisfying a layered image write request when the target of an
2133 * object request from the image request does not exist.
2135 * A page array big enough to hold the returned data is allocated
2136 * and supplied to rbd_img_request_fill() as the "data descriptor."
2137 * When the read completes, this page array will be transferred to
2138 * the original object request for the copyup operation.
2140 * If an error occurs, record it as the result of the original
2141 * object request and mark it done so it gets completed.
2143 static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
2145 struct rbd_img_request *img_request = NULL;
2146 struct rbd_img_request *parent_request = NULL;
2147 struct rbd_device *rbd_dev;
2150 struct page **pages = NULL;
2154 rbd_assert(obj_request_img_data_test(obj_request));
2155 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2157 img_request = obj_request->img_request;
2158 rbd_assert(img_request != NULL);
2159 rbd_dev = img_request->rbd_dev;
2160 rbd_assert(rbd_dev->parent != NULL);
2163 * First things first. The original osd request is of no
2164 * use to use any more, we'll need a new one that can hold
2165 * the two ops in a copyup request. We'll get that later,
2166 * but for now we can release the old one.
2168 rbd_osd_req_destroy(obj_request->osd_req);
2169 obj_request->osd_req = NULL;
2172 * Determine the byte range covered by the object in the
2173 * child image to which the original request was to be sent.
2175 img_offset = obj_request->img_offset - obj_request->offset;
2176 length = (u64)1 << rbd_dev->header.obj_order;
2179 * There is no defined parent data beyond the parent
2180 * overlap, so limit what we read at that boundary if
2183 if (img_offset + length > rbd_dev->parent_overlap) {
2184 rbd_assert(img_offset < rbd_dev->parent_overlap);
2185 length = rbd_dev->parent_overlap - img_offset;
2189 * Allocate a page array big enough to receive the data read
2192 page_count = (u32)calc_pages_for(0, length);
2193 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2194 if (IS_ERR(pages)) {
2195 result = PTR_ERR(pages);
2201 parent_request = rbd_img_request_create(rbd_dev->parent,
2204 if (!parent_request)
2206 rbd_obj_request_get(obj_request);
2207 parent_request->obj_request = obj_request;
2209 result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
2212 parent_request->copyup_pages = pages;
2214 parent_request->callback = rbd_img_obj_parent_read_full_callback;
2215 result = rbd_img_request_submit(parent_request);
2219 parent_request->copyup_pages = NULL;
2220 parent_request->obj_request = NULL;
2221 rbd_obj_request_put(obj_request);
2224 ceph_release_page_vector(pages, page_count);
2226 rbd_img_request_put(parent_request);
2227 obj_request->result = result;
2228 obj_request->xferred = 0;
2229 obj_request_done_set(obj_request);
2234 static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
2236 struct rbd_obj_request *orig_request;
2239 rbd_assert(!obj_request_img_data_test(obj_request));
2242 * All we need from the object request is the original
2243 * request and the result of the STAT op. Grab those, then
2244 * we're done with the request.
2246 orig_request = obj_request->obj_request;
2247 obj_request->obj_request = NULL;
2248 rbd_assert(orig_request);
2249 rbd_assert(orig_request->img_request);
2251 result = obj_request->result;
2252 obj_request->result = 0;
2254 dout("%s: obj %p for obj %p result %d %llu/%llu\n", __func__,
2255 obj_request, orig_request, result,
2256 obj_request->xferred, obj_request->length);
2257 rbd_obj_request_put(obj_request);
2259 rbd_assert(orig_request);
2260 rbd_assert(orig_request->img_request);
2263 * Our only purpose here is to determine whether the object
2264 * exists, and we don't want to treat the non-existence as
2265 * an error. If something else comes back, transfer the
2266 * error to the original request and complete it now.
2269 obj_request_existence_set(orig_request, true);
2270 } else if (result == -ENOENT) {
2271 obj_request_existence_set(orig_request, false);
2272 } else if (result) {
2273 orig_request->result = result;
2278 * Resubmit the original request now that we have recorded
2279 * whether the target object exists.
2281 orig_request->result = rbd_img_obj_request_submit(orig_request);
2283 if (orig_request->result)
2284 rbd_obj_request_complete(orig_request);
2285 rbd_obj_request_put(orig_request);
2288 static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
2290 struct rbd_obj_request *stat_request;
2291 struct rbd_device *rbd_dev;
2292 struct ceph_osd_client *osdc;
2293 struct page **pages = NULL;
2299 * The response data for a STAT call consists of:
2306 size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
2307 page_count = (u32)calc_pages_for(0, size);
2308 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2310 return PTR_ERR(pages);
2313 stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
2318 rbd_obj_request_get(obj_request);
2319 stat_request->obj_request = obj_request;
2320 stat_request->pages = pages;
2321 stat_request->page_count = page_count;
2323 rbd_assert(obj_request->img_request);
2324 rbd_dev = obj_request->img_request->rbd_dev;
2325 stat_request->osd_req = rbd_osd_req_create(rbd_dev, false,
2327 if (!stat_request->osd_req)
2329 stat_request->callback = rbd_img_obj_exists_callback;
2331 osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT);
2332 osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
2334 rbd_osd_req_format_read(stat_request);
2336 osdc = &rbd_dev->rbd_client->client->osdc;
2337 ret = rbd_obj_request_submit(osdc, stat_request);
2340 rbd_obj_request_put(obj_request);
2345 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
2347 struct rbd_img_request *img_request;
2348 struct rbd_device *rbd_dev;
2351 rbd_assert(obj_request_img_data_test(obj_request));
2353 img_request = obj_request->img_request;
2354 rbd_assert(img_request);
2355 rbd_dev = img_request->rbd_dev;
2358 * Only writes to layered images need special handling.
2359 * Reads and non-layered writes are simple object requests.
2360 * Layered writes that start beyond the end of the overlap
2361 * with the parent have no parent data, so they too are
2362 * simple object requests. Finally, if the target object is
2363 * known to already exist, its parent data has already been
2364 * copied, so a write to the object can also be handled as a
2365 * simple object request.
2367 if (!img_request_write_test(img_request) ||
2368 !img_request_layered_test(img_request) ||
2369 rbd_dev->parent_overlap <= obj_request->img_offset ||
2370 ((known = obj_request_known_test(obj_request)) &&
2371 obj_request_exists_test(obj_request))) {
2373 struct rbd_device *rbd_dev;
2374 struct ceph_osd_client *osdc;
2376 rbd_dev = obj_request->img_request->rbd_dev;
2377 osdc = &rbd_dev->rbd_client->client->osdc;
2379 return rbd_obj_request_submit(osdc, obj_request);
2383 * It's a layered write. The target object might exist but
2384 * we may not know that yet. If we know it doesn't exist,
2385 * start by reading the data for the full target object from
2386 * the parent so we can use it for a copyup to the target.
2389 return rbd_img_obj_parent_read_full(obj_request);
2391 /* We don't know whether the target exists. Go find out. */
2393 return rbd_img_obj_exists_submit(obj_request);
2396 static int rbd_img_request_submit(struct rbd_img_request *img_request)
2398 struct rbd_obj_request *obj_request;
2399 struct rbd_obj_request *next_obj_request;
2401 dout("%s: img %p\n", __func__, img_request);
2402 for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
2405 ret = rbd_img_obj_request_submit(obj_request);
2413 static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
2415 struct rbd_obj_request *obj_request;
2416 struct rbd_device *rbd_dev;
2419 rbd_assert(img_request_child_test(img_request));
2421 obj_request = img_request->obj_request;
2422 rbd_assert(obj_request);
2423 rbd_assert(obj_request->img_request);
2425 obj_request->result = img_request->result;
2426 if (obj_request->result)
2430 * We need to zero anything beyond the parent overlap
2431 * boundary. Since rbd_img_obj_request_read_callback()
2432 * will zero anything beyond the end of a short read, an
2433 * easy way to do this is to pretend the data from the
2434 * parent came up short--ending at the overlap boundary.
2436 rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length);
2437 obj_end = obj_request->img_offset + obj_request->length;
2438 rbd_dev = obj_request->img_request->rbd_dev;
2439 if (obj_end > rbd_dev->parent_overlap) {
2442 if (obj_request->img_offset < rbd_dev->parent_overlap)
2443 xferred = rbd_dev->parent_overlap -
2444 obj_request->img_offset;
2446 obj_request->xferred = min(img_request->xferred, xferred);
2448 obj_request->xferred = img_request->xferred;
2451 rbd_img_obj_request_read_callback(obj_request);
2452 rbd_obj_request_complete(obj_request);
2455 static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
2457 struct rbd_device *rbd_dev;
2458 struct rbd_img_request *img_request;
2461 rbd_assert(obj_request_img_data_test(obj_request));
2462 rbd_assert(obj_request->img_request != NULL);
2463 rbd_assert(obj_request->result == (s32) -ENOENT);
2464 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2466 rbd_dev = obj_request->img_request->rbd_dev;
2467 rbd_assert(rbd_dev->parent != NULL);
2468 /* rbd_read_finish(obj_request, obj_request->length); */
2469 img_request = rbd_img_request_create(rbd_dev->parent,
2470 obj_request->img_offset,
2471 obj_request->length,
2477 rbd_obj_request_get(obj_request);
2478 img_request->obj_request = obj_request;
2480 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2481 obj_request->bio_list);
2485 img_request->callback = rbd_img_parent_read_callback;
2486 result = rbd_img_request_submit(img_request);
2493 rbd_img_request_put(img_request);
2494 obj_request->result = result;
2495 obj_request->xferred = 0;
2496 obj_request_done_set(obj_request);
2499 static int rbd_obj_notify_ack(struct rbd_device *rbd_dev,
2500 u64 ver, u64 notify_id)
2502 struct rbd_obj_request *obj_request;
2503 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2506 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2507 OBJ_REQUEST_NODATA);
2512 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2513 if (!obj_request->osd_req)
2515 obj_request->callback = rbd_obj_request_put;
2517 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
2519 rbd_osd_req_format_read(obj_request);
2521 ret = rbd_obj_request_submit(osdc, obj_request);
2524 rbd_obj_request_put(obj_request);
2529 static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
2531 struct rbd_device *rbd_dev = (struct rbd_device *)data;
2537 dout("%s: \"%s\" notify_id %llu opcode %u\n", __func__,
2538 rbd_dev->header_name, (unsigned long long) notify_id,
2539 (unsigned int) opcode);
2540 (void)rbd_dev_refresh(rbd_dev, &hver);
2542 rbd_obj_notify_ack(rbd_dev, hver, notify_id);
2546 * Request sync osd watch/unwatch. The value of "start" determines
2547 * whether a watch request is being initiated or torn down.
2549 static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, int start)
2551 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2552 struct rbd_obj_request *obj_request;
2555 rbd_assert(start ^ !!rbd_dev->watch_event);
2556 rbd_assert(start ^ !!rbd_dev->watch_request);
2559 ret = ceph_osdc_create_event(osdc, rbd_watch_cb, rbd_dev,
2560 &rbd_dev->watch_event);
2563 rbd_assert(rbd_dev->watch_event != NULL);
2567 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2568 OBJ_REQUEST_NODATA);
2572 obj_request->osd_req = rbd_osd_req_create(rbd_dev, true, obj_request);
2573 if (!obj_request->osd_req)
2577 ceph_osdc_set_request_linger(osdc, obj_request->osd_req);
2579 ceph_osdc_unregister_linger_request(osdc,
2580 rbd_dev->watch_request->osd_req);
2582 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
2583 rbd_dev->watch_event->cookie,
2584 rbd_dev->header.obj_version, start);
2585 rbd_osd_req_format_write(obj_request);
2587 ret = rbd_obj_request_submit(osdc, obj_request);
2590 ret = rbd_obj_request_wait(obj_request);
2593 ret = obj_request->result;
2598 * A watch request is set to linger, so the underlying osd
2599 * request won't go away until we unregister it. We retain
2600 * a pointer to the object request during that time (in
2601 * rbd_dev->watch_request), so we'll keep a reference to
2602 * it. We'll drop that reference (below) after we've
2606 rbd_dev->watch_request = obj_request;
2611 /* We have successfully torn down the watch request */
2613 rbd_obj_request_put(rbd_dev->watch_request);
2614 rbd_dev->watch_request = NULL;
2616 /* Cancel the event if we're tearing down, or on error */
2617 ceph_osdc_cancel_event(rbd_dev->watch_event);
2618 rbd_dev->watch_event = NULL;
2620 rbd_obj_request_put(obj_request);
2626 * Synchronous osd object method call. Returns the number of bytes
2627 * returned in the outbound buffer, or a negative error code.
2629 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
2630 const char *object_name,
2631 const char *class_name,
2632 const char *method_name,
2633 const void *outbound,
2634 size_t outbound_size,
2636 size_t inbound_size,
2639 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2640 struct rbd_obj_request *obj_request;
2641 struct page **pages;
2646 * Method calls are ultimately read operations. The result
2647 * should placed into the inbound buffer provided. They
2648 * also supply outbound data--parameters for the object
2649 * method. Currently if this is present it will be a
2652 page_count = (u32)calc_pages_for(0, inbound_size);
2653 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2655 return PTR_ERR(pages);
2658 obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
2663 obj_request->pages = pages;
2664 obj_request->page_count = page_count;
2666 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2667 if (!obj_request->osd_req)
2670 osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
2671 class_name, method_name);
2672 if (outbound_size) {
2673 struct ceph_pagelist *pagelist;
2675 pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
2679 ceph_pagelist_init(pagelist);
2680 ceph_pagelist_append(pagelist, outbound, outbound_size);
2681 osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
2684 osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
2685 obj_request->pages, inbound_size,
2687 rbd_osd_req_format_read(obj_request);
2689 ret = rbd_obj_request_submit(osdc, obj_request);
2692 ret = rbd_obj_request_wait(obj_request);
2696 ret = obj_request->result;
2700 rbd_assert(obj_request->xferred < (u64)INT_MAX);
2701 ret = (int)obj_request->xferred;
2702 ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
2704 *version = obj_request->version;
2707 rbd_obj_request_put(obj_request);
2709 ceph_release_page_vector(pages, page_count);
2714 static void rbd_request_fn(struct request_queue *q)
2715 __releases(q->queue_lock) __acquires(q->queue_lock)
2717 struct rbd_device *rbd_dev = q->queuedata;
2718 bool read_only = rbd_dev->mapping.read_only;
2722 while ((rq = blk_fetch_request(q))) {
2723 bool write_request = rq_data_dir(rq) == WRITE;
2724 struct rbd_img_request *img_request;
2728 /* Ignore any non-FS requests that filter through. */
2730 if (rq->cmd_type != REQ_TYPE_FS) {
2731 dout("%s: non-fs request type %d\n", __func__,
2732 (int) rq->cmd_type);
2733 __blk_end_request_all(rq, 0);
2737 /* Ignore/skip any zero-length requests */
2739 offset = (u64) blk_rq_pos(rq) << SECTOR_SHIFT;
2740 length = (u64) blk_rq_bytes(rq);
2743 dout("%s: zero-length request\n", __func__);
2744 __blk_end_request_all(rq, 0);
2748 spin_unlock_irq(q->queue_lock);
2750 /* Disallow writes to a read-only device */
2752 if (write_request) {
2756 rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
2760 * Quit early if the mapped snapshot no longer
2761 * exists. It's still possible the snapshot will
2762 * have disappeared by the time our request arrives
2763 * at the osd, but there's no sense in sending it if
2766 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
2767 dout("request for non-existent snapshot");
2768 rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
2774 if (offset && length > U64_MAX - offset + 1) {
2775 rbd_warn(rbd_dev, "bad request range (%llu~%llu)\n",
2777 goto end_request; /* Shouldn't happen */
2781 img_request = rbd_img_request_create(rbd_dev, offset, length,
2782 write_request, false);
2786 img_request->rq = rq;
2788 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2791 result = rbd_img_request_submit(img_request);
2793 rbd_img_request_put(img_request);
2795 spin_lock_irq(q->queue_lock);
2797 rbd_warn(rbd_dev, "%s %llx at %llx result %d\n",
2798 write_request ? "write" : "read",
2799 length, offset, result);
2801 __blk_end_request_all(rq, result);
2807 * a queue callback. Makes sure that we don't create a bio that spans across
2808 * multiple osd objects. One exception would be with a single page bios,
2809 * which we handle later at bio_chain_clone_range()
2811 static int rbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
2812 struct bio_vec *bvec)
2814 struct rbd_device *rbd_dev = q->queuedata;
2815 sector_t sector_offset;
2816 sector_t sectors_per_obj;
2817 sector_t obj_sector_offset;
2821 * Find how far into its rbd object the partition-relative
2822 * bio start sector is to offset relative to the enclosing
2825 sector_offset = get_start_sect(bmd->bi_bdev) + bmd->bi_sector;
2826 sectors_per_obj = 1 << (rbd_dev->header.obj_order - SECTOR_SHIFT);
2827 obj_sector_offset = sector_offset & (sectors_per_obj - 1);
2830 * Compute the number of bytes from that offset to the end
2831 * of the object. Account for what's already used by the bio.
2833 ret = (int) (sectors_per_obj - obj_sector_offset) << SECTOR_SHIFT;
2834 if (ret > bmd->bi_size)
2835 ret -= bmd->bi_size;
2840 * Don't send back more than was asked for. And if the bio
2841 * was empty, let the whole thing through because: "Note
2842 * that a block device *must* allow a single page to be
2843 * added to an empty bio."
2845 rbd_assert(bvec->bv_len <= PAGE_SIZE);
2846 if (ret > (int) bvec->bv_len || !bmd->bi_size)
2847 ret = (int) bvec->bv_len;
2852 static void rbd_free_disk(struct rbd_device *rbd_dev)
2854 struct gendisk *disk = rbd_dev->disk;
2859 rbd_dev->disk = NULL;
2860 if (disk->flags & GENHD_FL_UP) {
2863 blk_cleanup_queue(disk->queue);
2868 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
2869 const char *object_name,
2870 u64 offset, u64 length,
2871 void *buf, u64 *version)
2874 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2875 struct rbd_obj_request *obj_request;
2876 struct page **pages = NULL;
2881 page_count = (u32) calc_pages_for(offset, length);
2882 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2884 ret = PTR_ERR(pages);
2887 obj_request = rbd_obj_request_create(object_name, offset, length,
2892 obj_request->pages = pages;
2893 obj_request->page_count = page_count;
2895 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2896 if (!obj_request->osd_req)
2899 osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
2900 offset, length, 0, 0);
2901 osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
2903 obj_request->length,
2904 obj_request->offset & ~PAGE_MASK,
2906 rbd_osd_req_format_read(obj_request);
2908 ret = rbd_obj_request_submit(osdc, obj_request);
2911 ret = rbd_obj_request_wait(obj_request);
2915 ret = obj_request->result;
2919 rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
2920 size = (size_t) obj_request->xferred;
2921 ceph_copy_from_page_vector(pages, buf, 0, size);
2922 rbd_assert(size <= (size_t) INT_MAX);
2925 *version = obj_request->version;
2928 rbd_obj_request_put(obj_request);
2930 ceph_release_page_vector(pages, page_count);
2936 * Read the complete header for the given rbd device.
2938 * Returns a pointer to a dynamically-allocated buffer containing
2939 * the complete and validated header. Caller can pass the address
2940 * of a variable that will be filled in with the version of the
2941 * header object at the time it was read.
2943 * Returns a pointer-coded errno if a failure occurs.
2945 static struct rbd_image_header_ondisk *
2946 rbd_dev_v1_header_read(struct rbd_device *rbd_dev, u64 *version)
2948 struct rbd_image_header_ondisk *ondisk = NULL;
2955 * The complete header will include an array of its 64-bit
2956 * snapshot ids, followed by the names of those snapshots as
2957 * a contiguous block of NUL-terminated strings. Note that
2958 * the number of snapshots could change by the time we read
2959 * it in, in which case we re-read it.
2966 size = sizeof (*ondisk);
2967 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
2969 ondisk = kmalloc(size, GFP_KERNEL);
2971 return ERR_PTR(-ENOMEM);
2973 ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name,
2974 0, size, ondisk, version);
2977 if ((size_t)ret < size) {
2979 rbd_warn(rbd_dev, "short header read (want %zd got %d)",
2983 if (!rbd_dev_ondisk_valid(ondisk)) {
2985 rbd_warn(rbd_dev, "invalid header");
2989 names_size = le64_to_cpu(ondisk->snap_names_len);
2990 want_count = snap_count;
2991 snap_count = le32_to_cpu(ondisk->snap_count);
2992 } while (snap_count != want_count);
2999 return ERR_PTR(ret);
3003 * reload the ondisk the header
3005 static int rbd_read_header(struct rbd_device *rbd_dev,
3006 struct rbd_image_header *header)
3008 struct rbd_image_header_ondisk *ondisk;
3012 ondisk = rbd_dev_v1_header_read(rbd_dev, &ver);
3014 return PTR_ERR(ondisk);
3015 ret = rbd_header_from_disk(header, ondisk);
3017 header->obj_version = ver;
3023 static void rbd_remove_all_snaps(struct rbd_device *rbd_dev)
3025 struct rbd_snap *snap;
3026 struct rbd_snap *next;
3028 list_for_each_entry_safe(snap, next, &rbd_dev->snaps, node) {
3029 list_del(&snap->node);
3030 rbd_snap_destroy(snap);
3034 static void rbd_update_mapping_size(struct rbd_device *rbd_dev)
3036 if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
3039 if (rbd_dev->mapping.size != rbd_dev->header.image_size) {
3042 rbd_dev->mapping.size = rbd_dev->header.image_size;
3043 size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
3044 dout("setting size to %llu sectors", (unsigned long long)size);
3045 set_capacity(rbd_dev->disk, size);
3050 * only read the first part of the ondisk header, without the snaps info
3052 static int rbd_dev_v1_refresh(struct rbd_device *rbd_dev, u64 *hver)
3055 struct rbd_image_header h;
3057 ret = rbd_read_header(rbd_dev, &h);
3061 down_write(&rbd_dev->header_rwsem);
3063 /* Update image size, and check for resize of mapped image */
3064 rbd_dev->header.image_size = h.image_size;
3065 rbd_update_mapping_size(rbd_dev);
3067 /* rbd_dev->header.object_prefix shouldn't change */
3068 kfree(rbd_dev->header.snap_sizes);
3069 kfree(rbd_dev->header.snap_names);
3070 /* osd requests may still refer to snapc */
3071 rbd_snap_context_put(rbd_dev->header.snapc);
3074 *hver = h.obj_version;
3075 rbd_dev->header.obj_version = h.obj_version;
3076 rbd_dev->header.image_size = h.image_size;
3077 rbd_dev->header.snapc = h.snapc;
3078 rbd_dev->header.snap_names = h.snap_names;
3079 rbd_dev->header.snap_sizes = h.snap_sizes;
3080 /* Free the extra copy of the object prefix */
3081 if (strcmp(rbd_dev->header.object_prefix, h.object_prefix))
3082 rbd_warn(rbd_dev, "object prefix changed (ignoring)");
3083 kfree(h.object_prefix);
3085 ret = rbd_dev_snaps_update(rbd_dev);
3087 up_write(&rbd_dev->header_rwsem);
3092 static int rbd_dev_refresh(struct rbd_device *rbd_dev, u64 *hver)
3096 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
3097 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3098 if (rbd_dev->image_format == 1)
3099 ret = rbd_dev_v1_refresh(rbd_dev, hver);
3101 ret = rbd_dev_v2_refresh(rbd_dev, hver);
3102 mutex_unlock(&ctl_mutex);
3103 revalidate_disk(rbd_dev->disk);
3105 rbd_warn(rbd_dev, "got notification but failed to "
3106 " update snaps: %d\n", ret);
3111 static int rbd_init_disk(struct rbd_device *rbd_dev)
3113 struct gendisk *disk;
3114 struct request_queue *q;
3117 /* create gendisk info */
3118 disk = alloc_disk(RBD_MINORS_PER_MAJOR);
3122 snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
3124 disk->major = rbd_dev->major;
3125 disk->first_minor = 0;
3126 disk->fops = &rbd_bd_ops;
3127 disk->private_data = rbd_dev;
3129 q = blk_init_queue(rbd_request_fn, &rbd_dev->lock);
3133 /* We use the default size, but let's be explicit about it. */
3134 blk_queue_physical_block_size(q, SECTOR_SIZE);
3136 /* set io sizes to object size */
3137 segment_size = rbd_obj_bytes(&rbd_dev->header);
3138 blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
3139 blk_queue_max_segment_size(q, segment_size);
3140 blk_queue_io_min(q, segment_size);
3141 blk_queue_io_opt(q, segment_size);
3143 blk_queue_merge_bvec(q, rbd_merge_bvec);
3146 q->queuedata = rbd_dev;
3148 rbd_dev->disk = disk;
3161 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
3163 return container_of(dev, struct rbd_device, dev);
3166 static ssize_t rbd_size_show(struct device *dev,
3167 struct device_attribute *attr, char *buf)
3169 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3171 return sprintf(buf, "%llu\n",
3172 (unsigned long long)rbd_dev->mapping.size);
3176 * Note this shows the features for whatever's mapped, which is not
3177 * necessarily the base image.
3179 static ssize_t rbd_features_show(struct device *dev,
3180 struct device_attribute *attr, char *buf)
3182 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3184 return sprintf(buf, "0x%016llx\n",
3185 (unsigned long long)rbd_dev->mapping.features);
3188 static ssize_t rbd_major_show(struct device *dev,
3189 struct device_attribute *attr, char *buf)
3191 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3194 return sprintf(buf, "%d\n", rbd_dev->major);
3196 return sprintf(buf, "(none)\n");
3200 static ssize_t rbd_client_id_show(struct device *dev,
3201 struct device_attribute *attr, char *buf)
3203 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3205 return sprintf(buf, "client%lld\n",
3206 ceph_client_id(rbd_dev->rbd_client->client));
3209 static ssize_t rbd_pool_show(struct device *dev,
3210 struct device_attribute *attr, char *buf)
3212 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3214 return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
3217 static ssize_t rbd_pool_id_show(struct device *dev,
3218 struct device_attribute *attr, char *buf)
3220 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3222 return sprintf(buf, "%llu\n",
3223 (unsigned long long) rbd_dev->spec->pool_id);
3226 static ssize_t rbd_name_show(struct device *dev,
3227 struct device_attribute *attr, char *buf)
3229 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3231 if (rbd_dev->spec->image_name)
3232 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
3234 return sprintf(buf, "(unknown)\n");
3237 static ssize_t rbd_image_id_show(struct device *dev,
3238 struct device_attribute *attr, char *buf)
3240 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3242 return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
3246 * Shows the name of the currently-mapped snapshot (or
3247 * RBD_SNAP_HEAD_NAME for the base image).
3249 static ssize_t rbd_snap_show(struct device *dev,
3250 struct device_attribute *attr,
3253 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3255 return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
3259 * For an rbd v2 image, shows the pool id, image id, and snapshot id
3260 * for the parent image. If there is no parent, simply shows
3261 * "(no parent image)".
3263 static ssize_t rbd_parent_show(struct device *dev,
3264 struct device_attribute *attr,
3267 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3268 struct rbd_spec *spec = rbd_dev->parent_spec;
3273 return sprintf(buf, "(no parent image)\n");
3275 count = sprintf(bufp, "pool_id %llu\npool_name %s\n",
3276 (unsigned long long) spec->pool_id, spec->pool_name);
3281 count = sprintf(bufp, "image_id %s\nimage_name %s\n", spec->image_id,
3282 spec->image_name ? spec->image_name : "(unknown)");
3287 count = sprintf(bufp, "snap_id %llu\nsnap_name %s\n",
3288 (unsigned long long) spec->snap_id, spec->snap_name);
3293 count = sprintf(bufp, "overlap %llu\n", rbd_dev->parent_overlap);
3298 return (ssize_t) (bufp - buf);
3301 static ssize_t rbd_image_refresh(struct device *dev,
3302 struct device_attribute *attr,
3306 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3309 ret = rbd_dev_refresh(rbd_dev, NULL);
3311 return ret < 0 ? ret : size;
3314 static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
3315 static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
3316 static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
3317 static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
3318 static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
3319 static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
3320 static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
3321 static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
3322 static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
3323 static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
3324 static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
3326 static struct attribute *rbd_attrs[] = {
3327 &dev_attr_size.attr,
3328 &dev_attr_features.attr,
3329 &dev_attr_major.attr,
3330 &dev_attr_client_id.attr,
3331 &dev_attr_pool.attr,
3332 &dev_attr_pool_id.attr,
3333 &dev_attr_name.attr,
3334 &dev_attr_image_id.attr,
3335 &dev_attr_current_snap.attr,
3336 &dev_attr_parent.attr,
3337 &dev_attr_refresh.attr,
3341 static struct attribute_group rbd_attr_group = {
3345 static const struct attribute_group *rbd_attr_groups[] = {
3350 static void rbd_sysfs_dev_release(struct device *dev)
3354 static struct device_type rbd_device_type = {
3356 .groups = rbd_attr_groups,
3357 .release = rbd_sysfs_dev_release,
3360 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
3362 kref_get(&spec->kref);
3367 static void rbd_spec_free(struct kref *kref);
3368 static void rbd_spec_put(struct rbd_spec *spec)
3371 kref_put(&spec->kref, rbd_spec_free);
3374 static struct rbd_spec *rbd_spec_alloc(void)
3376 struct rbd_spec *spec;
3378 spec = kzalloc(sizeof (*spec), GFP_KERNEL);
3381 kref_init(&spec->kref);
3386 static void rbd_spec_free(struct kref *kref)
3388 struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
3390 kfree(spec->pool_name);
3391 kfree(spec->image_id);
3392 kfree(spec->image_name);
3393 kfree(spec->snap_name);
3397 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
3398 struct rbd_spec *spec)
3400 struct rbd_device *rbd_dev;
3402 rbd_dev = kzalloc(sizeof (*rbd_dev), GFP_KERNEL);
3406 spin_lock_init(&rbd_dev->lock);
3408 INIT_LIST_HEAD(&rbd_dev->node);
3409 INIT_LIST_HEAD(&rbd_dev->snaps);
3410 init_rwsem(&rbd_dev->header_rwsem);
3412 rbd_dev->spec = spec;
3413 rbd_dev->rbd_client = rbdc;
3415 /* Initialize the layout used for all rbd requests */
3417 rbd_dev->layout.fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3418 rbd_dev->layout.fl_stripe_count = cpu_to_le32(1);
3419 rbd_dev->layout.fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3420 rbd_dev->layout.fl_pg_pool = cpu_to_le32((u32) spec->pool_id);
3425 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
3427 rbd_put_client(rbd_dev->rbd_client);
3428 rbd_spec_put(rbd_dev->spec);
3432 static void rbd_snap_destroy(struct rbd_snap *snap)
3438 static struct rbd_snap *rbd_snap_create(struct rbd_device *rbd_dev,
3439 const char *snap_name,
3440 u64 snap_id, u64 snap_size,
3443 struct rbd_snap *snap;
3445 snap = kzalloc(sizeof (*snap), GFP_KERNEL);
3447 return ERR_PTR(-ENOMEM);
3449 snap->name = snap_name;
3451 snap->size = snap_size;
3452 snap->features = snap_features;
3458 * Returns a dynamically-allocated snapshot name if successful, or a
3459 * pointer-coded error otherwise.
3461 static char *rbd_dev_v1_snap_info(struct rbd_device *rbd_dev, u32 which,
3462 u64 *snap_size, u64 *snap_features)
3467 rbd_assert(which < rbd_dev->header.snapc->num_snaps);
3469 /* Skip over names until we find the one we are looking for */
3471 snap_name = rbd_dev->header.snap_names;
3472 for (i = 0; i < which; i++)
3473 snap_name += strlen(snap_name) + 1;
3475 snap_name = kstrdup(snap_name, GFP_KERNEL);
3477 return ERR_PTR(-ENOMEM);
3479 *snap_size = rbd_dev->header.snap_sizes[which];
3480 *snap_features = 0; /* No features for v1 */
3486 * Get the size and object order for an image snapshot, or if
3487 * snap_id is CEPH_NOSNAP, gets this information for the base
3490 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
3491 u8 *order, u64 *snap_size)
3493 __le64 snapid = cpu_to_le64(snap_id);
3498 } __attribute__ ((packed)) size_buf = { 0 };
3500 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3502 &snapid, sizeof (snapid),
3503 &size_buf, sizeof (size_buf), NULL);
3504 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3507 if (ret < sizeof (size_buf))
3511 *order = size_buf.order;
3512 *snap_size = le64_to_cpu(size_buf.size);
3514 dout(" snap_id 0x%016llx order = %u, snap_size = %llu\n",
3515 (unsigned long long)snap_id, (unsigned int)*order,
3516 (unsigned long long)*snap_size);
3521 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
3523 return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
3524 &rbd_dev->header.obj_order,
3525 &rbd_dev->header.image_size);
3528 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
3534 reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL);
3538 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3539 "rbd", "get_object_prefix", NULL, 0,
3540 reply_buf, RBD_OBJ_PREFIX_LEN_MAX, NULL);
3541 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3546 rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
3547 p + ret, NULL, GFP_NOIO);
3550 if (IS_ERR(rbd_dev->header.object_prefix)) {
3551 ret = PTR_ERR(rbd_dev->header.object_prefix);
3552 rbd_dev->header.object_prefix = NULL;
3554 dout(" object_prefix = %s\n", rbd_dev->header.object_prefix);
3562 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
3565 __le64 snapid = cpu_to_le64(snap_id);
3569 } __attribute__ ((packed)) features_buf = { 0 };
3573 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3574 "rbd", "get_features",
3575 &snapid, sizeof (snapid),
3576 &features_buf, sizeof (features_buf), NULL);
3577 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3580 if (ret < sizeof (features_buf))
3583 incompat = le64_to_cpu(features_buf.incompat);
3584 if (incompat & ~RBD_FEATURES_SUPPORTED)
3587 *snap_features = le64_to_cpu(features_buf.features);
3589 dout(" snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
3590 (unsigned long long)snap_id,
3591 (unsigned long long)*snap_features,
3592 (unsigned long long)le64_to_cpu(features_buf.incompat));
3597 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
3599 return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
3600 &rbd_dev->header.features);
3603 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
3605 struct rbd_spec *parent_spec;
3607 void *reply_buf = NULL;
3615 parent_spec = rbd_spec_alloc();
3619 size = sizeof (__le64) + /* pool_id */
3620 sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX + /* image_id */
3621 sizeof (__le64) + /* snap_id */
3622 sizeof (__le64); /* overlap */
3623 reply_buf = kmalloc(size, GFP_KERNEL);
3629 snapid = cpu_to_le64(CEPH_NOSNAP);
3630 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3631 "rbd", "get_parent",
3632 &snapid, sizeof (snapid),
3633 reply_buf, size, NULL);
3634 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3639 end = reply_buf + ret;
3641 ceph_decode_64_safe(&p, end, parent_spec->pool_id, out_err);
3642 if (parent_spec->pool_id == CEPH_NOPOOL)
3643 goto out; /* No parent? No problem. */
3645 /* The ceph file layout needs to fit pool id in 32 bits */
3648 if (parent_spec->pool_id > (u64)U32_MAX) {
3649 rbd_warn(NULL, "parent pool id too large (%llu > %u)\n",
3650 (unsigned long long)parent_spec->pool_id, U32_MAX);
3654 image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
3655 if (IS_ERR(image_id)) {
3656 ret = PTR_ERR(image_id);
3659 parent_spec->image_id = image_id;
3660 ceph_decode_64_safe(&p, end, parent_spec->snap_id, out_err);
3661 ceph_decode_64_safe(&p, end, overlap, out_err);
3663 rbd_dev->parent_overlap = overlap;
3664 rbd_dev->parent_spec = parent_spec;
3665 parent_spec = NULL; /* rbd_dev now owns this */
3670 rbd_spec_put(parent_spec);
3675 static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
3679 __le64 stripe_count;
3680 } __attribute__ ((packed)) striping_info_buf = { 0 };
3681 size_t size = sizeof (striping_info_buf);
3688 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3689 "rbd", "get_stripe_unit_count", NULL, 0,
3690 (char *)&striping_info_buf, size, NULL);
3691 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3698 * We don't actually support the "fancy striping" feature
3699 * (STRIPINGV2) yet, but if the striping sizes are the
3700 * defaults the behavior is the same as before. So find
3701 * out, and only fail if the image has non-default values.
3704 obj_size = (u64)1 << rbd_dev->header.obj_order;
3705 p = &striping_info_buf;
3706 stripe_unit = ceph_decode_64(&p);
3707 if (stripe_unit != obj_size) {
3708 rbd_warn(rbd_dev, "unsupported stripe unit "
3709 "(got %llu want %llu)",
3710 stripe_unit, obj_size);
3713 stripe_count = ceph_decode_64(&p);
3714 if (stripe_count != 1) {
3715 rbd_warn(rbd_dev, "unsupported stripe count "
3716 "(got %llu want 1)", stripe_count);
3719 rbd_dev->header.stripe_unit = stripe_unit;
3720 rbd_dev->header.stripe_count = stripe_count;
3725 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
3727 size_t image_id_size;
3732 void *reply_buf = NULL;
3734 char *image_name = NULL;
3737 rbd_assert(!rbd_dev->spec->image_name);
3739 len = strlen(rbd_dev->spec->image_id);
3740 image_id_size = sizeof (__le32) + len;
3741 image_id = kmalloc(image_id_size, GFP_KERNEL);
3746 end = image_id + image_id_size;
3747 ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
3749 size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
3750 reply_buf = kmalloc(size, GFP_KERNEL);
3754 ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
3755 "rbd", "dir_get_name",
3756 image_id, image_id_size,
3757 reply_buf, size, NULL);
3761 end = reply_buf + ret;
3763 image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
3764 if (IS_ERR(image_name))
3767 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
3776 * When an rbd image has a parent image, it is identified by the
3777 * pool, image, and snapshot ids (not names). This function fills
3778 * in the names for those ids. (It's OK if we can't figure out the
3779 * name for an image id, but the pool and snapshot ids should always
3780 * exist and have names.) All names in an rbd spec are dynamically
3783 * When an image being mapped (not a parent) is probed, we have the
3784 * pool name and pool id, image name and image id, and the snapshot
3785 * name. The only thing we're missing is the snapshot id.
3787 * The set of snapshots for an image is not known until they have
3788 * been read by rbd_dev_snaps_update(), so we can't completely fill
3789 * in this information until after that has been called.
3791 static int rbd_dev_spec_update(struct rbd_device *rbd_dev)
3793 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3794 struct rbd_spec *spec = rbd_dev->spec;
3795 const char *pool_name;
3796 const char *image_name;
3797 const char *snap_name;
3801 * An image being mapped will have the pool name (etc.), but
3802 * we need to look up the snapshot id.
3804 if (spec->pool_name) {
3805 if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
3806 struct rbd_snap *snap;
3808 snap = snap_by_name(rbd_dev, spec->snap_name);
3811 spec->snap_id = snap->id;
3813 spec->snap_id = CEPH_NOSNAP;
3819 /* Get the pool name; we have to make our own copy of this */
3821 pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
3823 rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
3826 pool_name = kstrdup(pool_name, GFP_KERNEL);
3830 /* Fetch the image name; tolerate failure here */
3832 image_name = rbd_dev_image_name(rbd_dev);
3834 rbd_warn(rbd_dev, "unable to get image name");
3836 /* Look up the snapshot name, and make a copy */
3838 snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
3840 rbd_warn(rbd_dev, "no snapshot with id %llu", spec->snap_id);
3844 snap_name = kstrdup(snap_name, GFP_KERNEL);
3850 spec->pool_name = pool_name;
3851 spec->image_name = image_name;
3852 spec->snap_name = snap_name;
3862 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev, u64 *ver)
3871 struct ceph_snap_context *snapc;
3875 * We'll need room for the seq value (maximum snapshot id),
3876 * snapshot count, and array of that many snapshot ids.
3877 * For now we have a fixed upper limit on the number we're
3878 * prepared to receive.
3880 size = sizeof (__le64) + sizeof (__le32) +
3881 RBD_MAX_SNAP_COUNT * sizeof (__le64);
3882 reply_buf = kzalloc(size, GFP_KERNEL);
3886 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3887 "rbd", "get_snapcontext", NULL, 0,
3888 reply_buf, size, ver);
3889 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3894 end = reply_buf + ret;
3896 ceph_decode_64_safe(&p, end, seq, out);
3897 ceph_decode_32_safe(&p, end, snap_count, out);
3900 * Make sure the reported number of snapshot ids wouldn't go
3901 * beyond the end of our buffer. But before checking that,
3902 * make sure the computed size of the snapshot context we
3903 * allocate is representable in a size_t.
3905 if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
3910 if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
3914 snapc = rbd_snap_context_create(snap_count);
3920 for (i = 0; i < snap_count; i++)
3921 snapc->snaps[i] = ceph_decode_64(&p);
3923 rbd_dev->header.snapc = snapc;
3925 dout(" snap context seq = %llu, snap_count = %u\n",
3926 (unsigned long long)seq, (unsigned int)snap_count);
3933 static char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev, u32 which)
3943 size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
3944 reply_buf = kmalloc(size, GFP_KERNEL);
3946 return ERR_PTR(-ENOMEM);
3948 rbd_assert(which < rbd_dev->header.snapc->num_snaps);
3949 snap_id = cpu_to_le64(rbd_dev->header.snapc->snaps[which]);
3950 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3951 "rbd", "get_snapshot_name",
3952 &snap_id, sizeof (snap_id),
3953 reply_buf, size, NULL);
3954 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3956 snap_name = ERR_PTR(ret);
3961 end = reply_buf + ret;
3962 snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
3963 if (IS_ERR(snap_name))
3966 dout(" snap_id 0x%016llx snap_name = %s\n",
3967 (unsigned long long)le64_to_cpu(snap_id), snap_name);
3974 static char *rbd_dev_v2_snap_info(struct rbd_device *rbd_dev, u32 which,
3975 u64 *snap_size, u64 *snap_features)
3983 rbd_assert(which < rbd_dev->header.snapc->num_snaps);
3984 snap_id = rbd_dev->header.snapc->snaps[which];
3985 ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
3989 ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, &features);
3993 snap_name = rbd_dev_v2_snap_name(rbd_dev, which);
3994 if (!IS_ERR(snap_name)) {
3996 *snap_features = features;
4001 return ERR_PTR(ret);
4004 static char *rbd_dev_snap_info(struct rbd_device *rbd_dev, u32 which,
4005 u64 *snap_size, u64 *snap_features)
4007 if (rbd_dev->image_format == 1)
4008 return rbd_dev_v1_snap_info(rbd_dev, which,
4009 snap_size, snap_features);
4010 if (rbd_dev->image_format == 2)
4011 return rbd_dev_v2_snap_info(rbd_dev, which,
4012 snap_size, snap_features);
4013 return ERR_PTR(-EINVAL);
4016 static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev, u64 *hver)
4021 down_write(&rbd_dev->header_rwsem);
4023 /* Grab old order first, to see if it changes */
4025 obj_order = rbd_dev->header.obj_order,
4026 ret = rbd_dev_v2_image_size(rbd_dev);
4029 if (rbd_dev->header.obj_order != obj_order) {
4033 rbd_update_mapping_size(rbd_dev);
4035 ret = rbd_dev_v2_snap_context(rbd_dev, hver);
4036 dout("rbd_dev_v2_snap_context returned %d\n", ret);
4039 ret = rbd_dev_snaps_update(rbd_dev);
4040 dout("rbd_dev_snaps_update returned %d\n", ret);
4044 up_write(&rbd_dev->header_rwsem);
4050 * Scan the rbd device's current snapshot list and compare it to the
4051 * newly-received snapshot context. Remove any existing snapshots
4052 * not present in the new snapshot context. Add a new snapshot for
4053 * any snaphots in the snapshot context not in the current list.
4054 * And verify there are no changes to snapshots we already know
4057 * Assumes the snapshots in the snapshot context are sorted by
4058 * snapshot id, highest id first. (Snapshots in the rbd_dev's list
4059 * are also maintained in that order.)
4061 * Note that any error occurs while updating the snapshot list
4062 * aborts the update, and the entire list is cleared. The snapshot
4063 * list becomes inconsistent at that point anyway, so it might as
4066 static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
4068 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
4069 const u32 snap_count = snapc->num_snaps;
4070 struct list_head *head = &rbd_dev->snaps;
4071 struct list_head *links = head->next;
4075 dout("%s: snap count is %u\n", __func__, (unsigned int)snap_count);
4076 while (index < snap_count || links != head) {
4078 struct rbd_snap *snap;
4081 u64 snap_features = 0;
4083 snap_id = index < snap_count ? snapc->snaps[index]
4085 snap = links != head ? list_entry(links, struct rbd_snap, node)
4087 rbd_assert(!snap || snap->id != CEPH_NOSNAP);
4089 if (snap_id == CEPH_NOSNAP || (snap && snap->id > snap_id)) {
4090 struct list_head *next = links->next;
4093 * A previously-existing snapshot is not in
4094 * the new snap context.
4096 * If the now-missing snapshot is the one
4097 * the image represents, clear its existence
4098 * flag so we can avoid sending any more
4101 if (rbd_dev->spec->snap_id == snap->id)
4102 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4103 dout("removing %ssnap id %llu\n",
4104 rbd_dev->spec->snap_id == snap->id ?
4106 (unsigned long long)snap->id);
4108 list_del(&snap->node);
4109 rbd_snap_destroy(snap);
4111 /* Done with this list entry; advance */
4117 snap_name = rbd_dev_snap_info(rbd_dev, index,
4118 &snap_size, &snap_features);
4119 if (IS_ERR(snap_name)) {
4120 ret = PTR_ERR(snap_name);
4121 dout("failed to get snap info, error %d\n", ret);
4125 dout("entry %u: snap_id = %llu\n", (unsigned int)snap_count,
4126 (unsigned long long)snap_id);
4127 if (!snap || (snap_id != CEPH_NOSNAP && snap->id < snap_id)) {
4128 struct rbd_snap *new_snap;
4130 /* We haven't seen this snapshot before */
4132 new_snap = rbd_snap_create(rbd_dev, snap_name,
4133 snap_id, snap_size, snap_features);
4134 if (IS_ERR(new_snap)) {
4135 ret = PTR_ERR(new_snap);
4136 dout(" failed to add dev, error %d\n", ret);
4140 /* New goes before existing, or at end of list */
4142 dout(" added dev%s\n", snap ? "" : " at end\n");
4144 list_add_tail(&new_snap->node, &snap->node);
4146 list_add_tail(&new_snap->node, head);
4148 /* Already have this one */
4150 dout(" already present\n");
4152 rbd_assert(snap->size == snap_size);
4153 rbd_assert(!strcmp(snap->name, snap_name));
4154 rbd_assert(snap->features == snap_features);
4156 /* Done with this list entry; advance */
4158 links = links->next;
4161 /* Advance to the next entry in the snapshot context */
4165 dout("%s: done\n", __func__);
4169 rbd_remove_all_snaps(rbd_dev);
4174 static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
4179 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
4181 dev = &rbd_dev->dev;
4182 dev->bus = &rbd_bus_type;
4183 dev->type = &rbd_device_type;
4184 dev->parent = &rbd_root_dev;
4185 dev->release = rbd_dev_release;
4186 dev_set_name(dev, "%d", rbd_dev->dev_id);
4187 ret = device_register(dev);
4189 mutex_unlock(&ctl_mutex);
4194 static void rbd_bus_del_dev(struct rbd_device *rbd_dev)
4196 device_unregister(&rbd_dev->dev);
4199 static atomic64_t rbd_dev_id_max = ATOMIC64_INIT(0);
4202 * Get a unique rbd identifier for the given new rbd_dev, and add
4203 * the rbd_dev to the global list. The minimum rbd id is 1.
4205 static void rbd_dev_id_get(struct rbd_device *rbd_dev)
4207 rbd_dev->dev_id = atomic64_inc_return(&rbd_dev_id_max);
4209 spin_lock(&rbd_dev_list_lock);
4210 list_add_tail(&rbd_dev->node, &rbd_dev_list);
4211 spin_unlock(&rbd_dev_list_lock);
4212 dout("rbd_dev %p given dev id %llu\n", rbd_dev,
4213 (unsigned long long) rbd_dev->dev_id);
4217 * Remove an rbd_dev from the global list, and record that its
4218 * identifier is no longer in use.
4220 static void rbd_dev_id_put(struct rbd_device *rbd_dev)
4222 struct list_head *tmp;
4223 int rbd_id = rbd_dev->dev_id;
4226 rbd_assert(rbd_id > 0);
4228 dout("rbd_dev %p released dev id %llu\n", rbd_dev,
4229 (unsigned long long) rbd_dev->dev_id);
4230 spin_lock(&rbd_dev_list_lock);
4231 list_del_init(&rbd_dev->node);
4234 * If the id being "put" is not the current maximum, there
4235 * is nothing special we need to do.
4237 if (rbd_id != atomic64_read(&rbd_dev_id_max)) {
4238 spin_unlock(&rbd_dev_list_lock);
4243 * We need to update the current maximum id. Search the
4244 * list to find out what it is. We're more likely to find
4245 * the maximum at the end, so search the list backward.
4248 list_for_each_prev(tmp, &rbd_dev_list) {
4249 struct rbd_device *rbd_dev;
4251 rbd_dev = list_entry(tmp, struct rbd_device, node);
4252 if (rbd_dev->dev_id > max_id)
4253 max_id = rbd_dev->dev_id;
4255 spin_unlock(&rbd_dev_list_lock);
4258 * The max id could have been updated by rbd_dev_id_get(), in
4259 * which case it now accurately reflects the new maximum.
4260 * Be careful not to overwrite the maximum value in that
4263 atomic64_cmpxchg(&rbd_dev_id_max, rbd_id, max_id);
4264 dout(" max dev id has been reset\n");
4268 * Skips over white space at *buf, and updates *buf to point to the
4269 * first found non-space character (if any). Returns the length of
4270 * the token (string of non-white space characters) found. Note
4271 * that *buf must be terminated with '\0'.
4273 static inline size_t next_token(const char **buf)
4276 * These are the characters that produce nonzero for
4277 * isspace() in the "C" and "POSIX" locales.
4279 const char *spaces = " \f\n\r\t\v";
4281 *buf += strspn(*buf, spaces); /* Find start of token */
4283 return strcspn(*buf, spaces); /* Return token length */
4287 * Finds the next token in *buf, and if the provided token buffer is
4288 * big enough, copies the found token into it. The result, if
4289 * copied, is guaranteed to be terminated with '\0'. Note that *buf
4290 * must be terminated with '\0' on entry.
4292 * Returns the length of the token found (not including the '\0').
4293 * Return value will be 0 if no token is found, and it will be >=
4294 * token_size if the token would not fit.
4296 * The *buf pointer will be updated to point beyond the end of the
4297 * found token. Note that this occurs even if the token buffer is
4298 * too small to hold it.
4300 static inline size_t copy_token(const char **buf,
4306 len = next_token(buf);
4307 if (len < token_size) {
4308 memcpy(token, *buf, len);
4309 *(token + len) = '\0';
4317 * Finds the next token in *buf, dynamically allocates a buffer big
4318 * enough to hold a copy of it, and copies the token into the new
4319 * buffer. The copy is guaranteed to be terminated with '\0'. Note
4320 * that a duplicate buffer is created even for a zero-length token.
4322 * Returns a pointer to the newly-allocated duplicate, or a null
4323 * pointer if memory for the duplicate was not available. If
4324 * the lenp argument is a non-null pointer, the length of the token
4325 * (not including the '\0') is returned in *lenp.
4327 * If successful, the *buf pointer will be updated to point beyond
4328 * the end of the found token.
4330 * Note: uses GFP_KERNEL for allocation.
4332 static inline char *dup_token(const char **buf, size_t *lenp)
4337 len = next_token(buf);
4338 dup = kmemdup(*buf, len + 1, GFP_KERNEL);
4341 *(dup + len) = '\0';
4351 * Parse the options provided for an "rbd add" (i.e., rbd image
4352 * mapping) request. These arrive via a write to /sys/bus/rbd/add,
4353 * and the data written is passed here via a NUL-terminated buffer.
4354 * Returns 0 if successful or an error code otherwise.
4356 * The information extracted from these options is recorded in
4357 * the other parameters which return dynamically-allocated
4360 * The address of a pointer that will refer to a ceph options
4361 * structure. Caller must release the returned pointer using
4362 * ceph_destroy_options() when it is no longer needed.
4364 * Address of an rbd options pointer. Fully initialized by
4365 * this function; caller must release with kfree().
4367 * Address of an rbd image specification pointer. Fully
4368 * initialized by this function based on parsed options.
4369 * Caller must release with rbd_spec_put().
4371 * The options passed take this form:
4372 * <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
4375 * A comma-separated list of one or more monitor addresses.
4376 * A monitor address is an ip address, optionally followed
4377 * by a port number (separated by a colon).
4378 * I.e.: ip1[:port1][,ip2[:port2]...]
4380 * A comma-separated list of ceph and/or rbd options.
4382 * The name of the rados pool containing the rbd image.
4384 * The name of the image in that pool to map.
4386 * An optional snapshot id. If provided, the mapping will
4387 * present data from the image at the time that snapshot was
4388 * created. The image head is used if no snapshot id is
4389 * provided. Snapshot mappings are always read-only.
4391 static int rbd_add_parse_args(const char *buf,
4392 struct ceph_options **ceph_opts,
4393 struct rbd_options **opts,
4394 struct rbd_spec **rbd_spec)
4398 const char *mon_addrs;
4400 size_t mon_addrs_size;
4401 struct rbd_spec *spec = NULL;
4402 struct rbd_options *rbd_opts = NULL;
4403 struct ceph_options *copts;
4406 /* The first four tokens are required */
4408 len = next_token(&buf);
4410 rbd_warn(NULL, "no monitor address(es) provided");
4414 mon_addrs_size = len + 1;
4418 options = dup_token(&buf, NULL);
4422 rbd_warn(NULL, "no options provided");
4426 spec = rbd_spec_alloc();
4430 spec->pool_name = dup_token(&buf, NULL);
4431 if (!spec->pool_name)
4433 if (!*spec->pool_name) {
4434 rbd_warn(NULL, "no pool name provided");
4438 spec->image_name = dup_token(&buf, NULL);
4439 if (!spec->image_name)
4441 if (!*spec->image_name) {
4442 rbd_warn(NULL, "no image name provided");
4447 * Snapshot name is optional; default is to use "-"
4448 * (indicating the head/no snapshot).
4450 len = next_token(&buf);
4452 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
4453 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
4454 } else if (len > RBD_MAX_SNAP_NAME_LEN) {
4455 ret = -ENAMETOOLONG;
4458 snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
4461 *(snap_name + len) = '\0';
4462 spec->snap_name = snap_name;
4464 /* Initialize all rbd options to the defaults */
4466 rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
4470 rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
4472 copts = ceph_parse_options(options, mon_addrs,
4473 mon_addrs + mon_addrs_size - 1,
4474 parse_rbd_opts_token, rbd_opts);
4475 if (IS_ERR(copts)) {
4476 ret = PTR_ERR(copts);
4497 * An rbd format 2 image has a unique identifier, distinct from the
4498 * name given to it by the user. Internally, that identifier is
4499 * what's used to specify the names of objects related to the image.
4501 * A special "rbd id" object is used to map an rbd image name to its
4502 * id. If that object doesn't exist, then there is no v2 rbd image
4503 * with the supplied name.
4505 * This function will record the given rbd_dev's image_id field if
4506 * it can be determined, and in that case will return 0. If any
4507 * errors occur a negative errno will be returned and the rbd_dev's
4508 * image_id field will be unchanged (and should be NULL).
4510 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
4519 * When probing a parent image, the image id is already
4520 * known (and the image name likely is not). There's no
4521 * need to fetch the image id again in this case. We
4522 * do still need to set the image format though.
4524 if (rbd_dev->spec->image_id) {
4525 rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
4531 * First, see if the format 2 image id file exists, and if
4532 * so, get the image's persistent id from it.
4534 size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
4535 object_name = kmalloc(size, GFP_NOIO);
4538 sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
4539 dout("rbd id object name is %s\n", object_name);
4541 /* Response will be an encoded string, which includes a length */
4543 size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
4544 response = kzalloc(size, GFP_NOIO);
4550 /* If it doesn't exist we'll assume it's a format 1 image */
4552 ret = rbd_obj_method_sync(rbd_dev, object_name,
4553 "rbd", "get_id", NULL, 0,
4554 response, RBD_IMAGE_ID_LEN_MAX, NULL);
4555 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4556 if (ret == -ENOENT) {
4557 image_id = kstrdup("", GFP_KERNEL);
4558 ret = image_id ? 0 : -ENOMEM;
4560 rbd_dev->image_format = 1;
4561 } else if (ret > sizeof (__le32)) {
4564 image_id = ceph_extract_encoded_string(&p, p + ret,
4566 ret = IS_ERR(image_id) ? PTR_ERR(image_id) : 0;
4568 rbd_dev->image_format = 2;
4574 rbd_dev->spec->image_id = image_id;
4575 dout("image_id is %s\n", image_id);
4584 static int rbd_dev_v1_probe(struct rbd_device *rbd_dev)
4589 /* Record the header object name for this rbd image. */
4591 size = strlen(rbd_dev->spec->image_name) + sizeof (RBD_SUFFIX);
4592 rbd_dev->header_name = kmalloc(size, GFP_KERNEL);
4593 if (!rbd_dev->header_name) {
4597 sprintf(rbd_dev->header_name, "%s%s",
4598 rbd_dev->spec->image_name, RBD_SUFFIX);
4600 /* Populate rbd image metadata */
4602 ret = rbd_read_header(rbd_dev, &rbd_dev->header);
4606 /* Version 1 images have no parent (no layering) */
4608 rbd_dev->parent_spec = NULL;
4609 rbd_dev->parent_overlap = 0;
4611 dout("discovered version 1 image, header name is %s\n",
4612 rbd_dev->header_name);
4617 kfree(rbd_dev->header_name);
4618 rbd_dev->header_name = NULL;
4619 kfree(rbd_dev->spec->image_id);
4620 rbd_dev->spec->image_id = NULL;
4625 static int rbd_dev_v2_probe(struct rbd_device *rbd_dev)
4632 * Image id was filled in by the caller. Record the header
4633 * object name for this rbd image.
4635 size = sizeof (RBD_HEADER_PREFIX) + strlen(rbd_dev->spec->image_id);
4636 rbd_dev->header_name = kmalloc(size, GFP_KERNEL);
4637 if (!rbd_dev->header_name)
4639 sprintf(rbd_dev->header_name, "%s%s",
4640 RBD_HEADER_PREFIX, rbd_dev->spec->image_id);
4642 /* Get the size and object order for the image */
4643 ret = rbd_dev_v2_image_size(rbd_dev);
4647 /* Get the object prefix (a.k.a. block_name) for the image */
4649 ret = rbd_dev_v2_object_prefix(rbd_dev);
4653 /* Get the and check features for the image */
4655 ret = rbd_dev_v2_features(rbd_dev);
4659 /* If the image supports layering, get the parent info */
4661 if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
4662 ret = rbd_dev_v2_parent_info(rbd_dev);
4665 rbd_warn(rbd_dev, "WARNING: kernel support for "
4666 "layered rbd images is EXPERIMENTAL!");
4669 /* If the image supports fancy striping, get its parameters */
4671 if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
4672 ret = rbd_dev_v2_striping_info(rbd_dev);
4677 /* crypto and compression type aren't (yet) supported for v2 images */
4679 rbd_dev->header.crypt_type = 0;
4680 rbd_dev->header.comp_type = 0;
4682 /* Get the snapshot context, plus the header version */
4684 ret = rbd_dev_v2_snap_context(rbd_dev, &ver);
4687 rbd_dev->header.obj_version = ver;
4689 dout("discovered version 2 image, header name is %s\n",
4690 rbd_dev->header_name);
4694 rbd_dev->parent_overlap = 0;
4695 rbd_spec_put(rbd_dev->parent_spec);
4696 rbd_dev->parent_spec = NULL;
4697 kfree(rbd_dev->header_name);
4698 rbd_dev->header_name = NULL;
4699 kfree(rbd_dev->header.object_prefix);
4700 rbd_dev->header.object_prefix = NULL;
4705 static int rbd_dev_probe_parent(struct rbd_device *rbd_dev)
4707 struct rbd_device *parent = NULL;
4708 struct rbd_spec *parent_spec;
4709 struct rbd_client *rbdc;
4712 if (!rbd_dev->parent_spec)
4715 * We need to pass a reference to the client and the parent
4716 * spec when creating the parent rbd_dev. Images related by
4717 * parent/child relationships always share both.
4719 parent_spec = rbd_spec_get(rbd_dev->parent_spec);
4720 rbdc = __rbd_get_client(rbd_dev->rbd_client);
4723 parent = rbd_dev_create(rbdc, parent_spec);
4727 ret = rbd_dev_image_probe(parent);
4730 rbd_dev->parent = parent;
4735 rbd_spec_put(rbd_dev->parent_spec);
4736 kfree(rbd_dev->header_name);
4737 rbd_dev_destroy(parent);
4739 rbd_put_client(rbdc);
4740 rbd_spec_put(parent_spec);
4746 static int rbd_dev_probe_finish(struct rbd_device *rbd_dev)
4750 /* no need to lock here, as rbd_dev is not registered yet */
4751 ret = rbd_dev_snaps_update(rbd_dev);
4755 ret = rbd_dev_spec_update(rbd_dev);
4759 ret = rbd_dev_set_mapping(rbd_dev);
4763 /* generate unique id: find highest unique id, add one */
4764 rbd_dev_id_get(rbd_dev);
4766 /* Fill in the device name, now that we have its id. */
4767 BUILD_BUG_ON(DEV_NAME_LEN
4768 < sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH);
4769 sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id);
4771 /* Get our block major device number. */
4773 ret = register_blkdev(0, rbd_dev->name);
4776 rbd_dev->major = ret;
4778 /* Set up the blkdev mapping. */
4780 ret = rbd_init_disk(rbd_dev);
4782 goto err_out_blkdev;
4784 ret = rbd_bus_add_dev(rbd_dev);
4788 ret = rbd_dev_probe_parent(rbd_dev);
4792 ret = rbd_dev_header_watch_sync(rbd_dev, 1);
4796 /* Everything's ready. Announce the disk to the world. */
4798 set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
4799 set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4800 add_disk(rbd_dev->disk);
4802 pr_info("%s: added with size 0x%llx\n", rbd_dev->disk->disk_name,
4803 (unsigned long long) rbd_dev->mapping.size);
4808 /* this will also clean up rest of rbd_dev stuff */
4810 rbd_bus_del_dev(rbd_dev);
4814 rbd_free_disk(rbd_dev);
4816 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4818 rbd_dev_id_put(rbd_dev);
4820 rbd_remove_all_snaps(rbd_dev);
4826 * Probe for the existence of the header object for the given rbd
4827 * device. For format 2 images this includes determining the image
4830 static int rbd_dev_image_probe(struct rbd_device *rbd_dev)
4835 * Get the id from the image id object. If it's not a
4836 * format 2 image, we'll get ENOENT back, and we'll assume
4837 * it's a format 1 image.
4839 ret = rbd_dev_image_id(rbd_dev);
4842 rbd_assert(rbd_dev->spec->image_id);
4843 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4845 if (rbd_dev->image_format == 1)
4846 ret = rbd_dev_v1_probe(rbd_dev);
4848 ret = rbd_dev_v2_probe(rbd_dev);
4852 ret = rbd_dev_probe_finish(rbd_dev);
4854 rbd_header_free(&rbd_dev->header);
4858 kfree(rbd_dev->spec->image_id);
4859 rbd_dev->spec->image_id = NULL;
4861 dout("probe failed, returning %d\n", ret);
4866 static ssize_t rbd_add(struct bus_type *bus,
4870 struct rbd_device *rbd_dev = NULL;
4871 struct ceph_options *ceph_opts = NULL;
4872 struct rbd_options *rbd_opts = NULL;
4873 struct rbd_spec *spec = NULL;
4874 struct rbd_client *rbdc;
4875 struct ceph_osd_client *osdc;
4878 if (!try_module_get(THIS_MODULE))
4881 /* parse add command */
4882 rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
4884 goto err_out_module;
4886 rbdc = rbd_get_client(ceph_opts);
4891 ceph_opts = NULL; /* rbd_dev client now owns this */
4894 osdc = &rbdc->client->osdc;
4895 rc = ceph_pg_poolid_by_name(osdc->osdmap, spec->pool_name);
4897 goto err_out_client;
4898 spec->pool_id = (u64)rc;
4900 /* The ceph file layout needs to fit pool id in 32 bits */
4902 if (spec->pool_id > (u64)U32_MAX) {
4903 rbd_warn(NULL, "pool id too large (%llu > %u)\n",
4904 (unsigned long long)spec->pool_id, U32_MAX);
4906 goto err_out_client;
4909 rbd_dev = rbd_dev_create(rbdc, spec);
4911 goto err_out_client;
4912 rbdc = NULL; /* rbd_dev now owns this */
4913 spec = NULL; /* rbd_dev now owns this */
4915 rbd_dev->mapping.read_only = rbd_opts->read_only;
4917 rbd_opts = NULL; /* done with this */
4919 rc = rbd_dev_image_probe(rbd_dev);
4921 goto err_out_rbd_dev;
4925 rbd_spec_put(rbd_dev->parent_spec);
4926 kfree(rbd_dev->header_name);
4927 rbd_dev_destroy(rbd_dev);
4929 rbd_put_client(rbdc);
4932 ceph_destroy_options(ceph_opts);
4936 module_put(THIS_MODULE);
4938 dout("Error adding device %s\n", buf);
4943 static struct rbd_device *__rbd_get_dev(unsigned long dev_id)
4945 struct list_head *tmp;
4946 struct rbd_device *rbd_dev;
4948 spin_lock(&rbd_dev_list_lock);
4949 list_for_each(tmp, &rbd_dev_list) {
4950 rbd_dev = list_entry(tmp, struct rbd_device, node);
4951 if (rbd_dev->dev_id == dev_id) {
4952 spin_unlock(&rbd_dev_list_lock);
4956 spin_unlock(&rbd_dev_list_lock);
4960 static void rbd_dev_release(struct device *dev)
4962 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4964 if (rbd_dev->watch_event)
4965 rbd_dev_header_watch_sync(rbd_dev, 0);
4967 /* clean up and free blkdev */
4968 rbd_free_disk(rbd_dev);
4969 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4971 /* release allocated disk header fields */
4972 rbd_header_free(&rbd_dev->header);
4974 /* done with the id, and with the rbd_dev */
4975 rbd_dev_id_put(rbd_dev);
4976 rbd_assert(rbd_dev->rbd_client != NULL);
4977 rbd_spec_put(rbd_dev->parent_spec);
4978 kfree(rbd_dev->header_name);
4979 rbd_dev_destroy(rbd_dev);
4981 /* release module ref */
4982 module_put(THIS_MODULE);
4985 static void __rbd_remove(struct rbd_device *rbd_dev)
4987 rbd_remove_all_snaps(rbd_dev);
4988 rbd_bus_del_dev(rbd_dev);
4991 static ssize_t rbd_remove(struct bus_type *bus,
4995 struct rbd_device *rbd_dev = NULL;
5000 rc = strict_strtoul(buf, 10, &ul);
5004 /* convert to int; abort if we lost anything in the conversion */
5005 target_id = (int) ul;
5006 if (target_id != ul)
5009 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
5011 rbd_dev = __rbd_get_dev(target_id);
5017 spin_lock_irq(&rbd_dev->lock);
5018 if (rbd_dev->open_count)
5021 set_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);
5022 spin_unlock_irq(&rbd_dev->lock);
5026 while (rbd_dev->parent_spec) {
5027 struct rbd_device *first = rbd_dev;
5028 struct rbd_device *second = first->parent;
5029 struct rbd_device *third;
5032 * Follow to the parent with no grandparent and
5035 while (second && (third = second->parent)) {
5039 __rbd_remove(second);
5040 rbd_spec_put(first->parent_spec);
5041 first->parent_spec = NULL;
5042 first->parent_overlap = 0;
5043 first->parent = NULL;
5045 __rbd_remove(rbd_dev);
5048 mutex_unlock(&ctl_mutex);
5054 * create control files in sysfs
5057 static int rbd_sysfs_init(void)
5061 ret = device_register(&rbd_root_dev);
5065 ret = bus_register(&rbd_bus_type);
5067 device_unregister(&rbd_root_dev);
5072 static void rbd_sysfs_cleanup(void)
5074 bus_unregister(&rbd_bus_type);
5075 device_unregister(&rbd_root_dev);
5078 static int __init rbd_init(void)
5082 if (!libceph_compatible(NULL)) {
5083 rbd_warn(NULL, "libceph incompatibility (quitting)");
5087 rc = rbd_sysfs_init();
5090 pr_info("loaded " RBD_DRV_NAME_LONG "\n");
5094 static void __exit rbd_exit(void)
5096 rbd_sysfs_cleanup();
5099 module_init(rbd_init);
5100 module_exit(rbd_exit);
5102 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
5103 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
5104 MODULE_DESCRIPTION("rados block device");
5106 /* following authorship retained from original osdblk.c */
5107 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
5109 MODULE_LICENSE("GPL");