fs/nfs/pnfs.c

   1 /*
   2  *  pNFS functions to call and manage layout drivers.
   3  *
   4  *  Copyright (c) 2002 [year of first publication]
   5  *  The Regents of the University of Michigan
   6  *  All Rights Reserved
   7  *
   8  *  Dean Hildebrand <dhildebz@umich.edu>
   9  *
  10  *  Permission is granted to use, copy, create derivative works, and
  11  *  redistribute this software and such derivative works for any purpose,
  12  *  so long as the name of the University of Michigan is not used in
  13  *  any advertising or publicity pertaining to the use or distribution
  14  *  of this software without specific, written prior authorization. If
  15  *  the above copyright notice or any other identification of the
  16  *  University of Michigan is included in any copy of any portion of
  17  *  this software, then the disclaimer below must also be included.
  18  *
  19  *  This software is provided as is, without representation or warranty
  20  *  of any kind either express or implied, including without limitation
  21  *  the implied warranties of merchantability, fitness for a particular
  22  *  purpose, or noninfringement.  The Regents of the University of
  23  *  Michigan shall not be liable for any damages, including special,
  24  *  indirect, incidental, or consequential damages, with respect to any
  25  *  claim arising out of or in connection with the use of the software,
  26  *  even if it has been or is hereafter advised of the possibility of
  27  *  such damages.
  28  */
  29
  30 #include <linux/nfs_fs.h>
  31 #include <linux/nfs_page.h>
  32 #include <linux/module.h>
  33 #include <linux/sort.h>
  34 #include "internal.h"
  35 #include "pnfs.h"
  36 #include "iostat.h"
  37 #include "nfs4trace.h"
  38 #include "delegation.h"
  39 #include "nfs42.h"
  40
  41 #define NFSDBG_FACILITY         NFSDBG_PNFS
  42 #define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
  43
  44 /* Locking:
  45  *
  46  * pnfs_spinlock:
  47  *      protects pnfs_modules_tbl.
  48  */
  49 static DEFINE_SPINLOCK(pnfs_spinlock);
  50
  51 /*
  52  * pnfs_modules_tbl holds all pnfs modules
  53  */
  54 static LIST_HEAD(pnfs_modules_tbl);
  55
  56 static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo);
  57 static void pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
  58                 struct list_head *free_me,
  59                 const struct pnfs_layout_range *range,
  60                 u32 seq);
  61 static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
  62                                 struct list_head *tmp_list);
  63
  64 /* Return the registered pnfs layout driver module matching given id */
  65 static struct pnfs_layoutdriver_type *
  66 find_pnfs_driver_locked(u32 id)
  67 {
  68         struct pnfs_layoutdriver_type *local;
  69
  70         list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
  71                 if (local->id == id)
  72                         goto out;
  73         local = NULL;
  74 out:
  75         dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
  76         return local;
  77 }
  78
  79 static struct pnfs_layoutdriver_type *
  80 find_pnfs_driver(u32 id)
  81 {
  82         struct pnfs_layoutdriver_type *local;
  83
  84         spin_lock(&pnfs_spinlock);
  85         local = find_pnfs_driver_locked(id);
  86         if (local != NULL && !try_module_get(local->owner)) {
  87                 dprintk("%s: Could not grab reference on module\n", __func__);
  88                 local = NULL;
  89         }
  90         spin_unlock(&pnfs_spinlock);
  91         return local;
  92 }
  93
  94 void
  95 unset_pnfs_layoutdriver(struct nfs_server *nfss)
  96 {
  97         if (nfss->pnfs_curr_ld) {
  98                 if (nfss->pnfs_curr_ld->clear_layoutdriver)
  99                         nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
 100                 /* Decrement the MDS count. Purge the deviceid cache if zero */
 101                 if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
 102                         nfs4_deviceid_purge_client(nfss->nfs_client);
 103                 module_put(nfss->pnfs_curr_ld->owner);
 104         }
 105         nfss->pnfs_curr_ld = NULL;
 106 }
 107
 108 /*
 109  * When the server sends a list of layout types, we choose one in the order
 110  * given in the list below.
 111  *
 112  * FIXME: should this list be configurable in some fashion? module param?
 113  *        mount option? something else?
 114  */
 115 static const u32 ld_prefs[] = {
 116         LAYOUT_SCSI,
 117         LAYOUT_BLOCK_VOLUME,
 118         LAYOUT_OSD2_OBJECTS,
 119         LAYOUT_FLEX_FILES,
 120         LAYOUT_NFSV4_1_FILES,
 121         0
 122 };
 123
 124 static int
 125 ld_cmp(const void *e1, const void *e2)
 126 {
 127         u32 ld1 = *((u32 *)e1);
 128         u32 ld2 = *((u32 *)e2);
 129         int i;
 130
 131         for (i = 0; ld_prefs[i] != 0; i++) {
 132                 if (ld1 == ld_prefs[i])
 133                         return -1;
 134
 135                 if (ld2 == ld_prefs[i])
 136                         return 1;
 137         }
 138         return 0;
 139 }
 140
 141 /*
 142  * Try to set the server's pnfs module to the pnfs layout type specified by id.
 143  * Currently only one pNFS layout driver per filesystem is supported.
 144  *
 145  * @ids array of layout types supported by MDS.
 146  */
 147 void
 148 set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
 149                       struct nfs_fsinfo *fsinfo)
 150 {
 151         struct pnfs_layoutdriver_type *ld_type = NULL;
 152         u32 id;
 153         int i;
 154
 155         if (fsinfo->nlayouttypes == 0)
 156                 goto out_no_driver;
 157         if (!(server->nfs_client->cl_exchange_flags &
 158                  (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
 159                 printk(KERN_ERR "NFS: %s: cl_exchange_flags 0x%x\n",
 160                         __func__, server->nfs_client->cl_exchange_flags);
 161                 goto out_no_driver;
 162         }
 163
 164         sort(fsinfo->layouttype, fsinfo->nlayouttypes,
 165                 sizeof(*fsinfo->layouttype), ld_cmp, NULL);
 166
 167         for (i = 0; i < fsinfo->nlayouttypes; i++) {
 168                 id = fsinfo->layouttype[i];
 169                 ld_type = find_pnfs_driver(id);
 170                 if (!ld_type) {
 171                         request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX,
 172                                         id);
 173                         ld_type = find_pnfs_driver(id);
 174                 }
 175                 if (ld_type)
 176                         break;
 177         }
 178
 179         if (!ld_type) {
 180                 dprintk("%s: No pNFS module found!\n", __func__);
 181                 goto out_no_driver;
 182         }
 183
 184         server->pnfs_curr_ld = ld_type;
 185         if (ld_type->set_layoutdriver
 186             && ld_type->set_layoutdriver(server, mntfh)) {
 187                 printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
 188                         "driver %u.\n", __func__, id);
 189                 module_put(ld_type->owner);
 190                 goto out_no_driver;
 191         }
 192         /* Bump the MDS count */
 193         atomic_inc(&server->nfs_client->cl_mds_count);
 194
 195         dprintk("%s: pNFS module for %u set\n", __func__, id);
 196         return;
 197
 198 out_no_driver:
 199         dprintk("%s: Using NFSv4 I/O\n", __func__);
 200         server->pnfs_curr_ld = NULL;
 201 }
 202
 203 int
 204 pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 205 {
 206         int status = -EINVAL;
 207         struct pnfs_layoutdriver_type *tmp;
 208
 209         if (ld_type->id == 0) {
 210                 printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
 211                 return status;
 212         }
 213         if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
 214                 printk(KERN_ERR "NFS: %s Layout driver must provide "
 215                        "alloc_lseg and free_lseg.\n", __func__);
 216                 return status;
 217         }
 218
 219         spin_lock(&pnfs_spinlock);
 220         tmp = find_pnfs_driver_locked(ld_type->id);
 221         if (!tmp) {
 222                 list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
 223                 status = 0;
 224                 dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
 225                         ld_type->name);
 226         } else {
 227                 printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
 228                         __func__, ld_type->id);
 229         }
 230         spin_unlock(&pnfs_spinlock);
 231
 232         return status;
 233 }
 234 EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
 235
 236 void
 237 pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 238 {
 239         dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
 240         spin_lock(&pnfs_spinlock);
 241         list_del(&ld_type->pnfs_tblid);
 242         spin_unlock(&pnfs_spinlock);
 243 }
 244 EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
 245
 246 /*
 247  * pNFS client layout cache
 248  */
 249
 250 /* Need to hold i_lock if caller does not already hold reference */
 251 void
 252 pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
 253 {
 254         atomic_inc(&lo->plh_refcount);
 255 }
 256
 257 static struct pnfs_layout_hdr *
 258 pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
 259 {
 260         struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
 261         return ld->alloc_layout_hdr(ino, gfp_flags);
 262 }
 263
 264 static void
 265 pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
 266 {
 267         struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 268         struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
 269
 270         if (!list_empty(&lo->plh_layouts)) {
 271                 struct nfs_client *clp = server->nfs_client;
 272
 273                 spin_lock(&clp->cl_lock);
 274                 list_del_init(&lo->plh_layouts);
 275                 spin_unlock(&clp->cl_lock);
 276         }
 277         put_rpccred(lo->plh_lc_cred);
 278         return ld->free_layout_hdr(lo);
 279 }
 280
 281 static void
 282 pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 283 {
 284         struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
 285         dprintk("%s: freeing layout cache %p\n", __func__, lo);
 286         nfsi->layout = NULL;
 287         /* Reset MDS Threshold I/O counters */
 288         nfsi->write_io = 0;
 289         nfsi->read_io = 0;
 290 }
 291
 292 void
 293 pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
 294 {
 295         struct inode *inode = lo->plh_inode;
 296
 297         pnfs_layoutreturn_before_put_layout_hdr(lo);
 298
 299         if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
 300                 if (!list_empty(&lo->plh_segs))
 301                         WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n");
 302                 pnfs_detach_layout_hdr(lo);
 303                 spin_unlock(&inode->i_lock);
 304                 pnfs_free_layout_hdr(lo);
 305         }
 306 }
 307
 308 static void
 309 pnfs_set_plh_return_info(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode,
 310                          u32 seq)
 311 {
 312         if (lo->plh_return_iomode != 0 && lo->plh_return_iomode != iomode)
 313                 iomode = IOMODE_ANY;
 314         lo->plh_return_iomode = iomode;
 315         set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 316         if (seq != 0) {
 317                 WARN_ON_ONCE(lo->plh_return_seq != 0 && lo->plh_return_seq != seq);
 318                 lo->plh_return_seq = seq;
 319         }
 320 }
 321
 322 static void
 323 pnfs_clear_layoutreturn_info(struct pnfs_layout_hdr *lo)
 324 {
 325         struct pnfs_layout_segment *lseg;
 326         lo->plh_return_iomode = 0;
 327         lo->plh_return_seq = 0;
 328         clear_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 329         list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
 330                 if (!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 331                         continue;
 332                 pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 333         }
 334 }
 335
 336 static void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
 337 {
 338         clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
 339         clear_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags);
 340         smp_mb__after_atomic();
 341         wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
 342         rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
 343 }
 344
 345 static void
 346 pnfs_clear_lseg_state(struct pnfs_layout_segment *lseg,
 347                 struct list_head *free_me)
 348 {
 349         clear_bit(NFS_LSEG_ROC, &lseg->pls_flags);
 350         clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
 351         if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 352                 pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 353         if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 354                 pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 355 }
 356
 357 /*
 358  * Mark a pnfs_layout_hdr and all associated layout segments as invalid
 359  *
 360  * In order to continue using the pnfs_layout_hdr, a full recovery
 361  * is required.
 362  * Note that caller must hold inode->i_lock.
 363  */
 364 int
 365 pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
 366                 struct list_head *lseg_list)
 367 {
 368         struct pnfs_layout_range range = {
 369                 .iomode = IOMODE_ANY,
 370                 .offset = 0,
 371                 .length = NFS4_MAX_UINT64,
 372         };
 373         struct pnfs_layout_segment *lseg, *next;
 374
 375         set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 376         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 377                 pnfs_clear_lseg_state(lseg, lseg_list);
 378         pnfs_clear_layoutreturn_info(lo);
 379         pnfs_free_returned_lsegs(lo, lseg_list, &range, 0);
 380         if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) &&
 381             !test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
 382                 pnfs_clear_layoutreturn_waitbit(lo);
 383         return !list_empty(&lo->plh_segs);
 384 }
 385
 386 static int
 387 pnfs_iomode_to_fail_bit(u32 iomode)
 388 {
 389         return iomode == IOMODE_RW ?
 390                 NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 391 }
 392
 393 static void
 394 pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 395 {
 396         lo->plh_retry_timestamp = jiffies;
 397         if (!test_and_set_bit(fail_bit, &lo->plh_flags))
 398                 atomic_inc(&lo->plh_refcount);
 399 }
 400
 401 static void
 402 pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 403 {
 404         if (test_and_clear_bit(fail_bit, &lo->plh_flags))
 405                 atomic_dec(&lo->plh_refcount);
 406 }
 407
 408 static void
 409 pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 410 {
 411         struct inode *inode = lo->plh_inode;
 412         struct pnfs_layout_range range = {
 413                 .iomode = iomode,
 414                 .offset = 0,
 415                 .length = NFS4_MAX_UINT64,
 416         };
 417         LIST_HEAD(head);
 418
 419         spin_lock(&inode->i_lock);
 420         pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
 421         pnfs_mark_matching_lsegs_invalid(lo, &head, &range, 0);
 422         spin_unlock(&inode->i_lock);
 423         pnfs_free_lseg_list(&head);
 424         dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
 425                         iomode == IOMODE_RW ?  "RW" : "READ");
 426 }
 427
 428 static bool
 429 pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 430 {
 431         unsigned long start, end;
 432         int fail_bit = pnfs_iomode_to_fail_bit(iomode);
 433
 434         if (test_bit(fail_bit, &lo->plh_flags) == 0)
 435                 return false;
 436         end = jiffies;
 437         start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
 438         if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
 439                 /* It is time to retry the failed layoutgets */
 440                 pnfs_layout_clear_fail_bit(lo, fail_bit);
 441                 return false;
 442         }
 443         return true;
 444 }
 445
 446 static void
 447 pnfs_init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg,
 448                 const struct pnfs_layout_range *range,
 449                 const nfs4_stateid *stateid)
 450 {
 451         INIT_LIST_HEAD(&lseg->pls_list);
 452         INIT_LIST_HEAD(&lseg->pls_lc_list);
 453         atomic_set(&lseg->pls_refcount, 1);
 454         set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
 455         lseg->pls_layout = lo;
 456         lseg->pls_range = *range;
 457         lseg->pls_seq = be32_to_cpu(stateid->seqid);
 458 }
 459
 460 static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
 461 {
 462         if (lseg != NULL) {
 463                 struct inode *inode = lseg->pls_layout->plh_inode;
 464                 NFS_SERVER(inode)->pnfs_curr_ld->free_lseg(lseg);
 465         }
 466 }
 467
 468 static void
 469 pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 470                 struct pnfs_layout_segment *lseg)
 471 {
 472         WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 473         list_del_init(&lseg->pls_list);
 474         /* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 475         atomic_dec(&lo->plh_refcount);
 476         if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 477                 return;
 478         if (list_empty(&lo->plh_segs) &&
 479             !test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
 480             !test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
 481                 if (atomic_read(&lo->plh_outstanding) == 0)
 482                         set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 483                 clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 484         }
 485 }
 486
 487 static bool
 488 pnfs_cache_lseg_for_layoutreturn(struct pnfs_layout_hdr *lo,
 489                 struct pnfs_layout_segment *lseg)
 490 {
 491         if (test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
 492             pnfs_layout_is_valid(lo)) {
 493                 pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 494                 list_move_tail(&lseg->pls_list, &lo->plh_return_segs);
 495                 return true;
 496         }
 497         return false;
 498 }
 499
 500 void
 501 pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 502 {
 503         struct pnfs_layout_hdr *lo;
 504         struct inode *inode;
 505
 506         if (!lseg)
 507                 return;
 508
 509         dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 510                 atomic_read(&lseg->pls_refcount),
 511                 test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 512
 513         lo = lseg->pls_layout;
 514         inode = lo->plh_inode;
 515
 516         if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
 517                 if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 518                         spin_unlock(&inode->i_lock);
 519                         return;
 520                 }
 521                 pnfs_get_layout_hdr(lo);
 522                 pnfs_layout_remove_lseg(lo, lseg);
 523                 if (pnfs_cache_lseg_for_layoutreturn(lo, lseg))
 524                         lseg = NULL;
 525                 spin_unlock(&inode->i_lock);
 526                 pnfs_free_lseg(lseg);
 527                 pnfs_put_layout_hdr(lo);
 528         }
 529 }
 530 EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 531
 532 static void pnfs_free_lseg_async_work(struct work_struct *work)
 533 {
 534         struct pnfs_layout_segment *lseg;
 535         struct pnfs_layout_hdr *lo;
 536
 537         lseg = container_of(work, struct pnfs_layout_segment, pls_work);
 538         lo = lseg->pls_layout;
 539
 540         pnfs_free_lseg(lseg);
 541         pnfs_put_layout_hdr(lo);
 542 }
 543
 544 static void pnfs_free_lseg_async(struct pnfs_layout_segment *lseg)
 545 {
 546         INIT_WORK(&lseg->pls_work, pnfs_free_lseg_async_work);
 547         schedule_work(&lseg->pls_work);
 548 }
 549
 550 void
 551 pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg)
 552 {
 553         if (!lseg)
 554                 return;
 555
 556         assert_spin_locked(&lseg->pls_layout->plh_inode->i_lock);
 557
 558         dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 559                 atomic_read(&lseg->pls_refcount),
 560                 test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 561         if (atomic_dec_and_test(&lseg->pls_refcount)) {
 562                 struct pnfs_layout_hdr *lo = lseg->pls_layout;
 563                 if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 564                         return;
 565                 pnfs_layout_remove_lseg(lo, lseg);
 566                 if (!pnfs_cache_lseg_for_layoutreturn(lo, lseg)) {
 567                         pnfs_get_layout_hdr(lo);
 568                         pnfs_free_lseg_async(lseg);
 569                 }
 570         }
 571 }
 572
 573 /*
 574  * is l2 fully contained in l1?
 575  *   start1                             end1
 576  *   [----------------------------------)
 577  *           start2           end2
 578  *           [----------------)
 579  */
 580 static bool
 581 pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
 582                  const struct pnfs_layout_range *l2)
 583 {
 584         u64 start1 = l1->offset;
 585         u64 end1 = pnfs_end_offset(start1, l1->length);
 586         u64 start2 = l2->offset;
 587         u64 end2 = pnfs_end_offset(start2, l2->length);
 588
 589         return (start1 <= start2) && (end1 >= end2);
 590 }
 591
 592 static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
 593                 struct list_head *tmp_list)
 594 {
 595         if (!atomic_dec_and_test(&lseg->pls_refcount))
 596                 return false;
 597         pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
 598         list_add(&lseg->pls_list, tmp_list);
 599         return true;
 600 }
 601
 602 /* Returns 1 if lseg is removed from list, 0 otherwise */
 603 static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
 604                              struct list_head *tmp_list)
 605 {
 606         int rv = 0;
 607
 608         if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 609                 /* Remove the reference keeping the lseg in the
 610                  * list.  It will now be removed when all
 611                  * outstanding io is finished.
 612                  */
 613                 dprintk("%s: lseg %p ref %d\n", __func__, lseg,
 614                         atomic_read(&lseg->pls_refcount));
 615                 if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
 616                         rv = 1;
 617         }
 618         return rv;
 619 }
 620
 621 /*
 622  * Compare 2 layout stateid sequence ids, to see which is newer,
 623  * taking into account wraparound issues.
 624  */
 625 static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
 626 {
 627         return (s32)(s1 - s2) > 0;
 628 }
 629
 630 static bool
 631 pnfs_should_free_range(const struct pnfs_layout_range *lseg_range,
 632                  const struct pnfs_layout_range *recall_range)
 633 {
 634         return (recall_range->iomode == IOMODE_ANY ||
 635                 lseg_range->iomode == recall_range->iomode) &&
 636                pnfs_lseg_range_intersecting(lseg_range, recall_range);
 637 }
 638
 639 static bool
 640 pnfs_match_lseg_recall(const struct pnfs_layout_segment *lseg,
 641                 const struct pnfs_layout_range *recall_range,
 642                 u32 seq)
 643 {
 644         if (seq != 0 && pnfs_seqid_is_newer(lseg->pls_seq, seq))
 645                 return false;
 646         if (recall_range == NULL)
 647                 return true;
 648         return pnfs_should_free_range(&lseg->pls_range, recall_range);
 649 }
 650
 651 /**
 652  * pnfs_mark_matching_lsegs_invalid - tear down lsegs or mark them for later
 653  * @lo: layout header containing the lsegs
 654  * @tmp_list: list head where doomed lsegs should go
 655  * @recall_range: optional recall range argument to match (may be NULL)
 656  * @seq: only invalidate lsegs obtained prior to this sequence (may be 0)
 657  *
 658  * Walk the list of lsegs in the layout header, and tear down any that should
 659  * be destroyed. If "recall_range" is specified then the segment must match
 660  * that range. If "seq" is non-zero, then only match segments that were handed
 661  * out at or before that sequence.
 662  *
 663  * Returns number of matching invalid lsegs remaining in list after scanning
 664  * it and purging them.
 665  */
 666 int
 667 pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 668                             struct list_head *tmp_list,
 669                             const struct pnfs_layout_range *recall_range,
 670                             u32 seq)
 671 {
 672         struct pnfs_layout_segment *lseg, *next;
 673         int remaining = 0;
 674
 675         dprintk("%s:Begin lo %p\n", __func__, lo);
 676
 677         if (list_empty(&lo->plh_segs))
 678                 return 0;
 679         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 680                 if (pnfs_match_lseg_recall(lseg, recall_range, seq)) {
 681                         dprintk("%s: freeing lseg %p iomode %d seq %u"
 682                                 "offset %llu length %llu\n", __func__,
 683                                 lseg, lseg->pls_range.iomode, lseg->pls_seq,
 684                                 lseg->pls_range.offset, lseg->pls_range.length);
 685                         if (!mark_lseg_invalid(lseg, tmp_list))
 686                                 remaining++;
 687                 }
 688         dprintk("%s:Return %i\n", __func__, remaining);
 689         return remaining;
 690 }
 691
 692 static void
 693 pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
 694                 struct list_head *free_me,
 695                 const struct pnfs_layout_range *range,
 696                 u32 seq)
 697 {
 698         struct pnfs_layout_segment *lseg, *next;
 699
 700         list_for_each_entry_safe(lseg, next, &lo->plh_return_segs, pls_list) {
 701                 if (pnfs_match_lseg_recall(lseg, range, seq))
 702                         list_move_tail(&lseg->pls_list, free_me);
 703         }
 704 }
 705
 706 /* note free_me must contain lsegs from a single layout_hdr */
 707 void
 708 pnfs_free_lseg_list(struct list_head *free_me)
 709 {
 710         struct pnfs_layout_segment *lseg, *tmp;
 711
 712         if (list_empty(free_me))
 713                 return;
 714
 715         list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
 716                 list_del(&lseg->pls_list);
 717                 pnfs_free_lseg(lseg);
 718         }
 719 }
 720
 721 void
 722 pnfs_destroy_layout(struct nfs_inode *nfsi)
 723 {
 724         struct pnfs_layout_hdr *lo;
 725         LIST_HEAD(tmp_list);
 726
 727         spin_lock(&nfsi->vfs_inode.i_lock);
 728         lo = nfsi->layout;
 729         if (lo) {
 730                 pnfs_get_layout_hdr(lo);
 731                 pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
 732                 pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
 733                 pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
 734                 spin_unlock(&nfsi->vfs_inode.i_lock);
 735                 pnfs_free_lseg_list(&tmp_list);
 736                 nfs_commit_inode(&nfsi->vfs_inode, 0);
 737                 pnfs_put_layout_hdr(lo);
 738         } else
 739                 spin_unlock(&nfsi->vfs_inode.i_lock);
 740 }
 741 EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
 742
 743 static bool
 744 pnfs_layout_add_bulk_destroy_list(struct inode *inode,
 745                 struct list_head *layout_list)
 746 {
 747         struct pnfs_layout_hdr *lo;
 748         bool ret = false;
 749
 750         spin_lock(&inode->i_lock);
 751         lo = NFS_I(inode)->layout;
 752         if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
 753                 pnfs_get_layout_hdr(lo);
 754                 list_add(&lo->plh_bulk_destroy, layout_list);
 755                 ret = true;
 756         }
 757         spin_unlock(&inode->i_lock);
 758         return ret;
 759 }
 760
 761 /* Caller must hold rcu_read_lock and clp->cl_lock */
 762 static int
 763 pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
 764                 struct nfs_server *server,
 765                 struct list_head *layout_list)
 766 {
 767         struct pnfs_layout_hdr *lo, *next;
 768         struct inode *inode;
 769
 770         list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
 771                 if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
 772                         continue;
 773                 inode = igrab(lo->plh_inode);
 774                 if (inode == NULL)
 775                         continue;
 776                 list_del_init(&lo->plh_layouts);
 777                 if (pnfs_layout_add_bulk_destroy_list(inode, layout_list))
 778                         continue;
 779                 rcu_read_unlock();
 780                 spin_unlock(&clp->cl_lock);
 781                 iput(inode);
 782                 spin_lock(&clp->cl_lock);
 783                 rcu_read_lock();
 784                 return -EAGAIN;
 785         }
 786         return 0;
 787 }
 788
 789 static int
 790 pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
 791                 bool is_bulk_recall)
 792 {
 793         struct pnfs_layout_hdr *lo;
 794         struct inode *inode;
 795         LIST_HEAD(lseg_list);
 796         int ret = 0;
 797
 798         while (!list_empty(layout_list)) {
 799                 lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
 800                                 plh_bulk_destroy);
 801                 dprintk("%s freeing layout for inode %lu\n", __func__,
 802                         lo->plh_inode->i_ino);
 803                 inode = lo->plh_inode;
 804
 805                 pnfs_layoutcommit_inode(inode, false);
 806
 807                 spin_lock(&inode->i_lock);
 808                 list_del_init(&lo->plh_bulk_destroy);
 809                 if (pnfs_mark_layout_stateid_invalid(lo, &lseg_list)) {
 810                         if (is_bulk_recall)
 811                                 set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 812                         ret = -EAGAIN;
 813                 }
 814                 spin_unlock(&inode->i_lock);
 815                 pnfs_free_lseg_list(&lseg_list);
 816                 /* Free all lsegs that are attached to commit buckets */
 817                 nfs_commit_inode(inode, 0);
 818                 pnfs_put_layout_hdr(lo);
 819                 iput(inode);
 820         }
 821         return ret;
 822 }
 823
 824 int
 825 pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
 826                 struct nfs_fsid *fsid,
 827                 bool is_recall)
 828 {
 829         struct nfs_server *server;
 830         LIST_HEAD(layout_list);
 831
 832         spin_lock(&clp->cl_lock);
 833         rcu_read_lock();
 834 restart:
 835         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 836                 if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
 837                         continue;
 838                 if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 839                                 server,
 840                                 &layout_list) != 0)
 841                         goto restart;
 842         }
 843         rcu_read_unlock();
 844         spin_unlock(&clp->cl_lock);
 845
 846         if (list_empty(&layout_list))
 847                 return 0;
 848         return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 849 }
 850
 851 int
 852 pnfs_destroy_layouts_byclid(struct nfs_client *clp,
 853                 bool is_recall)
 854 {
 855         struct nfs_server *server;
 856         LIST_HEAD(layout_list);
 857
 858         spin_lock(&clp->cl_lock);
 859         rcu_read_lock();
 860 restart:
 861         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 862                 if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 863                                         server,
 864                                         &layout_list) != 0)
 865                         goto restart;
 866         }
 867         rcu_read_unlock();
 868         spin_unlock(&clp->cl_lock);
 869
 870         if (list_empty(&layout_list))
 871                 return 0;
 872         return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 873 }
 874
 875 /*
 876  * Called by the state manger to remove all layouts established under an
 877  * expired lease.
 878  */
 879 void
 880 pnfs_destroy_all_layouts(struct nfs_client *clp)
 881 {
 882         nfs4_deviceid_mark_client_invalid(clp);
 883         nfs4_deviceid_purge_client(clp);
 884
 885         pnfs_destroy_layouts_byclid(clp, false);
 886 }
 887
 888 /* update lo->plh_stateid with new if is more recent */
 889 void
 890 pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
 891                         bool update_barrier)
 892 {
 893         u32 oldseq, newseq, new_barrier = 0;
 894
 895         oldseq = be32_to_cpu(lo->plh_stateid.seqid);
 896         newseq = be32_to_cpu(new->seqid);
 897
 898         if (!pnfs_layout_is_valid(lo)) {
 899                 nfs4_stateid_copy(&lo->plh_stateid, new);
 900                 lo->plh_barrier = newseq;
 901                 pnfs_clear_layoutreturn_info(lo);
 902                 clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 903                 return;
 904         }
 905         if (pnfs_seqid_is_newer(newseq, oldseq)) {
 906                 nfs4_stateid_copy(&lo->plh_stateid, new);
 907                 /*
 908                  * Because of wraparound, we want to keep the barrier
 909                  * "close" to the current seqids.
 910                  */
 911                 new_barrier = newseq - atomic_read(&lo->plh_outstanding);
 912         }
 913         if (update_barrier)
 914                 new_barrier = be32_to_cpu(new->seqid);
 915         else if (new_barrier == 0)
 916                 return;
 917         if (pnfs_seqid_is_newer(new_barrier, lo->plh_barrier))
 918                 lo->plh_barrier = new_barrier;
 919 }
 920
 921 static bool
 922 pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
 923                 const nfs4_stateid *stateid)
 924 {
 925         u32 seqid = be32_to_cpu(stateid->seqid);
 926
 927         return !pnfs_seqid_is_newer(seqid, lo->plh_barrier);
 928 }
 929
 930 /* lget is set to 1 if called from inside send_layoutget call chain */
 931 static bool
 932 pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
 933 {
 934         return lo->plh_block_lgets ||
 935                 test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 936 }
 937
 938 /*
 939  * Get layout from server.
 940  *    for now, assume that whole file layouts are requested.
 941  *    arg->offset: 0
 942  *    arg->length: all ones
 943  */
 944 static struct pnfs_layout_segment *
 945 send_layoutget(struct pnfs_layout_hdr *lo,
 946            struct nfs_open_context *ctx,
 947            nfs4_stateid *stateid,
 948            const struct pnfs_layout_range *range,
 949            long *timeout, gfp_t gfp_flags)
 950 {
 951         struct inode *ino = lo->plh_inode;
 952         struct nfs_server *server = NFS_SERVER(ino);
 953         struct nfs4_layoutget *lgp;
 954         loff_t i_size;
 955
 956         dprintk("--> %s\n", __func__);
 957
 958         /*
 959          * Synchronously retrieve layout information from server and
 960          * store in lseg. If we race with a concurrent seqid morphing
 961          * op, then re-send the LAYOUTGET.
 962          */
 963         lgp = kzalloc(sizeof(*lgp), gfp_flags);
 964         if (lgp == NULL)
 965                 return ERR_PTR(-ENOMEM);
 966
 967         i_size = i_size_read(ino);
 968
 969         lgp->args.minlength = PAGE_SIZE;
 970         if (lgp->args.minlength > range->length)
 971                 lgp->args.minlength = range->length;
 972         if (range->iomode == IOMODE_READ) {
 973                 if (range->offset >= i_size)
 974                         lgp->args.minlength = 0;
 975                 else if (i_size - range->offset < lgp->args.minlength)
 976                         lgp->args.minlength = i_size - range->offset;
 977         }
 978         lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
 979         pnfs_copy_range(&lgp->args.range, range);
 980         lgp->args.type = server->pnfs_curr_ld->id;
 981         lgp->args.inode = ino;
 982         lgp->args.ctx = get_nfs_open_context(ctx);
 983         nfs4_stateid_copy(&lgp->args.stateid, stateid);
 984         lgp->gfp_flags = gfp_flags;
 985         lgp->cred = lo->plh_lc_cred;
 986
 987         return nfs4_proc_layoutget(lgp, timeout, gfp_flags);
 988 }
 989
 990 static void pnfs_clear_layoutcommit(struct inode *inode,
 991                 struct list_head *head)
 992 {
 993         struct nfs_inode *nfsi = NFS_I(inode);
 994         struct pnfs_layout_segment *lseg, *tmp;
 995
 996         if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
 997                 return;
 998         list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
 999                 if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
1000                         continue;
1001                 pnfs_lseg_dec_and_remove_zero(lseg, head);
1002         }
1003 }
1004
1005 void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
1006                 const nfs4_stateid *arg_stateid,
1007                 const struct pnfs_layout_range *range,
1008                 const nfs4_stateid *stateid)
1009 {
1010         struct inode *inode = lo->plh_inode;
1011         LIST_HEAD(freeme);
1012
1013         spin_lock(&inode->i_lock);
1014         if (!pnfs_layout_is_valid(lo) || !arg_stateid ||
1015             !nfs4_stateid_match_other(&lo->plh_stateid, arg_stateid))
1016                 goto out_unlock;
1017         if (stateid) {
1018                 u32 seq = be32_to_cpu(arg_stateid->seqid);
1019
1020                 pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
1021                 pnfs_free_returned_lsegs(lo, &freeme, range, seq);
1022                 pnfs_set_layout_stateid(lo, stateid, true);
1023         } else
1024                 pnfs_mark_layout_stateid_invalid(lo, &freeme);
1025 out_unlock:
1026         pnfs_clear_layoutreturn_waitbit(lo);
1027         spin_unlock(&inode->i_lock);
1028         pnfs_free_lseg_list(&freeme);
1029
1030 }
1031
1032 static bool
1033 pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo,
1034                 nfs4_stateid *stateid,
1035                 enum pnfs_iomode *iomode)
1036 {
1037         /* Serialise LAYOUTGET/LAYOUTRETURN */
1038         if (atomic_read(&lo->plh_outstanding) != 0)
1039                 return false;
1040         if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
1041                 return false;
1042         set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
1043         pnfs_get_layout_hdr(lo);
1044         if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
1045                 if (stateid != NULL) {
1046                         nfs4_stateid_copy(stateid, &lo->plh_stateid);
1047                         if (lo->plh_return_seq != 0)
1048                                 stateid->seqid = cpu_to_be32(lo->plh_return_seq);
1049                 }
1050                 if (iomode != NULL)
1051                         *iomode = lo->plh_return_iomode;
1052                 pnfs_clear_layoutreturn_info(lo);
1053                 return true;
1054         }
1055         if (stateid != NULL)
1056                 nfs4_stateid_copy(stateid, &lo->plh_stateid);
1057         if (iomode != NULL)
1058                 *iomode = IOMODE_ANY;
1059         return true;
1060 }
1061
1062 static void
1063 pnfs_init_layoutreturn_args(struct nfs4_layoutreturn_args *args,
1064                 struct pnfs_layout_hdr *lo,
1065                 const nfs4_stateid *stateid,
1066                 enum pnfs_iomode iomode)
1067 {
1068         struct inode *inode = lo->plh_inode;
1069
1070         args->layout_type = NFS_SERVER(inode)->pnfs_curr_ld->id;
1071         args->inode = inode;
1072         args->range.iomode = iomode;
1073         args->range.offset = 0;
1074         args->range.length = NFS4_MAX_UINT64;
1075         args->layout = lo;
1076         nfs4_stateid_copy(&args->stateid, stateid);
1077 }
1078
1079 static int
1080 pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo, const nfs4_stateid *stateid,
1081                        enum pnfs_iomode iomode, bool sync)
1082 {
1083         struct inode *ino = lo->plh_inode;
1084         struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1085         struct nfs4_layoutreturn *lrp;
1086         int status = 0;
1087
1088         lrp = kzalloc(sizeof(*lrp), GFP_NOFS);
1089         if (unlikely(lrp == NULL)) {
1090                 status = -ENOMEM;
1091                 spin_lock(&ino->i_lock);
1092                 pnfs_clear_layoutreturn_waitbit(lo);
1093                 spin_unlock(&ino->i_lock);
1094                 pnfs_put_layout_hdr(lo);
1095                 goto out;
1096         }
1097
1098         pnfs_init_layoutreturn_args(&lrp->args, lo, stateid, iomode);
1099         lrp->args.ld_private = &lrp->ld_private;
1100         lrp->clp = NFS_SERVER(ino)->nfs_client;
1101         lrp->cred = lo->plh_lc_cred;
1102         if (ld->prepare_layoutreturn)
1103                 ld->prepare_layoutreturn(&lrp->args);
1104
1105         status = nfs4_proc_layoutreturn(lrp, sync);
1106 out:
1107         dprintk("<-- %s status: %d\n", __func__, status);
1108         return status;
1109 }
1110
1111 /* Return true if layoutreturn is needed */
1112 static bool
1113 pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
1114 {
1115         struct pnfs_layout_segment *s;
1116
1117         if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1118                 return false;
1119
1120         /* Defer layoutreturn until all lsegs are done */
1121         list_for_each_entry(s, &lo->plh_segs, pls_list) {
1122                 if (test_bit(NFS_LSEG_LAYOUTRETURN, &s->pls_flags))
1123                         return false;
1124         }
1125
1126         return true;
1127 }
1128
1129 static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
1130 {
1131         struct inode *inode= lo->plh_inode;
1132
1133         if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1134                 return;
1135         spin_lock(&inode->i_lock);
1136         if (pnfs_layout_need_return(lo)) {
1137                 nfs4_stateid stateid;
1138                 enum pnfs_iomode iomode;
1139                 bool send;
1140
1141                 send = pnfs_prepare_layoutreturn(lo, &stateid, &iomode);
1142                 spin_unlock(&inode->i_lock);
1143                 if (send) {
1144                         /* Send an async layoutreturn so we dont deadlock */
1145                         pnfs_send_layoutreturn(lo, &stateid, iomode, false);
1146                 }
1147         } else
1148                 spin_unlock(&inode->i_lock);
1149 }
1150
1151 /*
1152  * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
1153  * when the layout segment list is empty.
1154  *
1155  * Note that a pnfs_layout_hdr can exist with an empty layout segment
1156  * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
1157  * deviceid is marked invalid.
1158  */
1159 int
1160 _pnfs_return_layout(struct inode *ino)
1161 {
1162         struct pnfs_layout_hdr *lo = NULL;
1163         struct nfs_inode *nfsi = NFS_I(ino);
1164         LIST_HEAD(tmp_list);
1165         nfs4_stateid stateid;
1166         int status = 0;
1167         bool send;
1168
1169         dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
1170
1171         spin_lock(&ino->i_lock);
1172         lo = nfsi->layout;
1173         if (!lo) {
1174                 spin_unlock(&ino->i_lock);
1175                 dprintk("NFS: %s no layout to return\n", __func__);
1176                 goto out;
1177         }
1178         /* Reference matched in nfs4_layoutreturn_release */
1179         pnfs_get_layout_hdr(lo);
1180         /* Is there an outstanding layoutreturn ? */
1181         if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1182                 spin_unlock(&ino->i_lock);
1183                 if (wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1184                                         TASK_UNINTERRUPTIBLE))
1185                         goto out_put_layout_hdr;
1186                 spin_lock(&ino->i_lock);
1187         }
1188         pnfs_clear_layoutcommit(ino, &tmp_list);
1189         pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL, 0);
1190
1191         if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) {
1192                 struct pnfs_layout_range range = {
1193                         .iomode         = IOMODE_ANY,
1194                         .offset         = 0,
1195                         .length         = NFS4_MAX_UINT64,
1196                 };
1197                 NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
1198         }
1199
1200         /* Don't send a LAYOUTRETURN if list was initially empty */
1201         if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
1202                 spin_unlock(&ino->i_lock);
1203                 dprintk("NFS: %s no layout segments to return\n", __func__);
1204                 goto out_put_layout_hdr;
1205         }
1206
1207         send = pnfs_prepare_layoutreturn(lo, &stateid, NULL);
1208         spin_unlock(&ino->i_lock);
1209         if (send)
1210                 status = pnfs_send_layoutreturn(lo, &stateid, IOMODE_ANY, true);
1211 out_put_layout_hdr:
1212         pnfs_free_lseg_list(&tmp_list);
1213         pnfs_put_layout_hdr(lo);
1214 out:
1215         dprintk("<-- %s status: %d\n", __func__, status);
1216         return status;
1217 }
1218
1219 int
1220 pnfs_commit_and_return_layout(struct inode *inode)
1221 {
1222         struct pnfs_layout_hdr *lo;
1223         int ret;
1224
1225         spin_lock(&inode->i_lock);
1226         lo = NFS_I(inode)->layout;
1227         if (lo == NULL) {
1228                 spin_unlock(&inode->i_lock);
1229                 return 0;
1230         }
1231         pnfs_get_layout_hdr(lo);
1232         /* Block new layoutgets and read/write to ds */
1233         lo->plh_block_lgets++;
1234         spin_unlock(&inode->i_lock);
1235         filemap_fdatawait(inode->i_mapping);
1236         ret = pnfs_layoutcommit_inode(inode, true);
1237         if (ret == 0)
1238                 ret = _pnfs_return_layout(inode);
1239         spin_lock(&inode->i_lock);
1240         lo->plh_block_lgets--;
1241         spin_unlock(&inode->i_lock);
1242         pnfs_put_layout_hdr(lo);
1243         return ret;
1244 }
1245
1246 bool pnfs_roc(struct inode *ino,
1247                 struct nfs4_layoutreturn_args *args,
1248                 struct nfs4_layoutreturn_res *res,
1249                 const struct rpc_cred *cred)
1250 {
1251         struct nfs_inode *nfsi = NFS_I(ino);
1252         struct nfs_open_context *ctx;
1253         struct nfs4_state *state;
1254         struct pnfs_layout_hdr *lo;
1255         struct pnfs_layout_segment *lseg, *next;
1256         nfs4_stateid stateid;
1257         enum pnfs_iomode iomode = 0;
1258         bool layoutreturn = false, roc = false;
1259         bool skip_read = false;
1260
1261         if (!nfs_have_layout(ino))
1262                 return false;
1263 retry:
1264         spin_lock(&ino->i_lock);
1265         lo = nfsi->layout;
1266         if (!lo || !pnfs_layout_is_valid(lo) ||
1267             test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
1268                 goto out_noroc;
1269         if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1270                 pnfs_get_layout_hdr(lo);
1271                 spin_unlock(&ino->i_lock);
1272                 wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1273                                 TASK_UNINTERRUPTIBLE);
1274                 pnfs_put_layout_hdr(lo);
1275                 goto retry;
1276         }
1277
1278         /* no roc if we hold a delegation */
1279         if (nfs4_check_delegation(ino, FMODE_READ)) {
1280                 if (nfs4_check_delegation(ino, FMODE_WRITE))
1281                         goto out_noroc;
1282                 skip_read = true;
1283         }
1284
1285         list_for_each_entry(ctx, &nfsi->open_files, list) {
1286                 state = ctx->state;
1287                 if (state == NULL)
1288                         continue;
1289                 /* Don't return layout if there is open file state */
1290                 if (state->state & FMODE_WRITE)
1291                         goto out_noroc;
1292                 if (state->state & FMODE_READ)
1293                         skip_read = true;
1294         }
1295
1296
1297         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) {
1298                 if (skip_read && lseg->pls_range.iomode == IOMODE_READ)
1299                         continue;
1300                 /* If we are sending layoutreturn, invalidate all valid lsegs */
1301                 if (!test_and_clear_bit(NFS_LSEG_ROC, &lseg->pls_flags))
1302                         continue;
1303                 /*
1304                  * Note: mark lseg for return so pnfs_layout_remove_lseg
1305                  * doesn't invalidate the layout for us.
1306                  */
1307                 set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1308                 if (!mark_lseg_invalid(lseg, &lo->plh_return_segs))
1309                         continue;
1310                 pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
1311         }
1312
1313         if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1314                 goto out_noroc;
1315
1316         /* ROC in two conditions:
1317          * 1. there are ROC lsegs
1318          * 2. we don't send layoutreturn
1319          */
1320         /* lo ref dropped in pnfs_roc_release() */
1321         layoutreturn = pnfs_prepare_layoutreturn(lo, &stateid, &iomode);
1322         /* If the creds don't match, we can't compound the layoutreturn */
1323         if (!layoutreturn || cred != lo->plh_lc_cred)
1324                 goto out_noroc;
1325
1326         roc = layoutreturn;
1327         pnfs_init_layoutreturn_args(args, lo, &stateid, iomode);
1328         res->lrs_present = 0;
1329         layoutreturn = false;
1330
1331 out_noroc:
1332         spin_unlock(&ino->i_lock);
1333         pnfs_layoutcommit_inode(ino, true);
1334         if (roc) {
1335                 struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1336                 if (ld->prepare_layoutreturn)
1337                         ld->prepare_layoutreturn(args);
1338                 return true;
1339         }
1340         if (layoutreturn)
1341                 pnfs_send_layoutreturn(lo, &stateid, iomode, true);
1342         return false;
1343 }
1344
1345 void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
1346                 struct nfs4_layoutreturn_res *res,
1347                 int ret)
1348 {
1349         struct pnfs_layout_hdr *lo = args->layout;
1350         const nfs4_stateid *arg_stateid = NULL;
1351         const nfs4_stateid *res_stateid = NULL;
1352         struct nfs4_xdr_opaque_data *ld_private = args->ld_private;
1353
1354         if (ret == 0) {
1355                 arg_stateid = &args->stateid;
1356                 if (res->lrs_present)
1357                         res_stateid = &res->stateid;
1358         }
1359         pnfs_layoutreturn_free_lsegs(lo, arg_stateid, &args->range,
1360                         res_stateid);
1361         if (ld_private && ld_private->ops && ld_private->ops->free)
1362                 ld_private->ops->free(ld_private);
1363         pnfs_put_layout_hdr(lo);
1364         trace_nfs4_layoutreturn_on_close(args->inode, 0);
1365 }
1366
1367 bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
1368 {
1369         struct nfs_inode *nfsi = NFS_I(ino);
1370         struct pnfs_layout_hdr *lo;
1371         bool sleep = false;
1372
1373         /* we might not have grabbed lo reference. so need to check under
1374          * i_lock */
1375         spin_lock(&ino->i_lock);
1376         lo = nfsi->layout;
1377         if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1378                 rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
1379                 sleep = true;
1380         }
1381         spin_unlock(&ino->i_lock);
1382         return sleep;
1383 }
1384
1385 /*
1386  * Compare two layout segments for sorting into layout cache.
1387  * We want to preferentially return RW over RO layouts, so ensure those
1388  * are seen first.
1389  */
1390 static s64
1391 pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1392            const struct pnfs_layout_range *l2)
1393 {
1394         s64 d;
1395
1396         /* high offset > low offset */
1397         d = l1->offset - l2->offset;
1398         if (d)
1399                 return d;
1400
1401         /* short length > long length */
1402         d = l2->length - l1->length;
1403         if (d)
1404                 return d;
1405
1406         /* read > read/write */
1407         return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1408 }
1409
1410 static bool
1411 pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1412                 const struct pnfs_layout_range *l2)
1413 {
1414         return pnfs_lseg_range_cmp(l1, l2) > 0;
1415 }
1416
1417 static bool
1418 pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1419                 struct pnfs_layout_segment *old)
1420 {
1421         return false;
1422 }
1423
1424 void
1425 pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1426                    struct pnfs_layout_segment *lseg,
1427                    bool (*is_after)(const struct pnfs_layout_range *,
1428                            const struct pnfs_layout_range *),
1429                    bool (*do_merge)(struct pnfs_layout_segment *,
1430                            struct pnfs_layout_segment *),
1431                    struct list_head *free_me)
1432 {
1433         struct pnfs_layout_segment *lp, *tmp;
1434
1435         dprintk("%s:Begin\n", __func__);
1436
1437         list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1438                 if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1439                         continue;
1440                 if (do_merge(lseg, lp)) {
1441                         mark_lseg_invalid(lp, free_me);
1442                         continue;
1443                 }
1444                 if (is_after(&lseg->pls_range, &lp->pls_range))
1445                         continue;
1446                 list_add_tail(&lseg->pls_list, &lp->pls_list);
1447                 dprintk("%s: inserted lseg %p "
1448                         "iomode %d offset %llu length %llu before "
1449                         "lp %p iomode %d offset %llu length %llu\n",
1450                         __func__, lseg, lseg->pls_range.iomode,
1451                         lseg->pls_range.offset, lseg->pls_range.length,
1452                         lp, lp->pls_range.iomode, lp->pls_range.offset,
1453                         lp->pls_range.length);
1454                 goto out;
1455         }
1456         list_add_tail(&lseg->pls_list, &lo->plh_segs);
1457         dprintk("%s: inserted lseg %p "
1458                 "iomode %d offset %llu length %llu at tail\n",
1459                 __func__, lseg, lseg->pls_range.iomode,
1460                 lseg->pls_range.offset, lseg->pls_range.length);
1461 out:
1462         pnfs_get_layout_hdr(lo);
1463
1464         dprintk("%s:Return\n", __func__);
1465 }
1466 EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1467
1468 static void
1469 pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1470                    struct pnfs_layout_segment *lseg,
1471                    struct list_head *free_me)
1472 {
1473         struct inode *inode = lo->plh_inode;
1474         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1475
1476         if (ld->add_lseg != NULL)
1477                 ld->add_lseg(lo, lseg, free_me);
1478         else
1479                 pnfs_generic_layout_insert_lseg(lo, lseg,
1480                                 pnfs_lseg_range_is_after,
1481                                 pnfs_lseg_no_merge,
1482                                 free_me);
1483 }
1484
1485 static struct pnfs_layout_hdr *
1486 alloc_init_layout_hdr(struct inode *ino,
1487                       struct nfs_open_context *ctx,
1488                       gfp_t gfp_flags)
1489 {
1490         struct pnfs_layout_hdr *lo;
1491
1492         lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1493         if (!lo)
1494                 return NULL;
1495         atomic_set(&lo->plh_refcount, 1);
1496         INIT_LIST_HEAD(&lo->plh_layouts);
1497         INIT_LIST_HEAD(&lo->plh_segs);
1498         INIT_LIST_HEAD(&lo->plh_return_segs);
1499         INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1500         lo->plh_inode = ino;
1501         lo->plh_lc_cred = get_rpccred(ctx->cred);
1502         lo->plh_flags |= 1 << NFS_LAYOUT_INVALID_STID;
1503         return lo;
1504 }
1505
1506 static struct pnfs_layout_hdr *
1507 pnfs_find_alloc_layout(struct inode *ino,
1508                        struct nfs_open_context *ctx,
1509                        gfp_t gfp_flags)
1510         __releases(&ino->i_lock)
1511         __acquires(&ino->i_lock)
1512 {
1513         struct nfs_inode *nfsi = NFS_I(ino);
1514         struct pnfs_layout_hdr *new = NULL;
1515
1516         dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1517
1518         if (nfsi->layout != NULL)
1519                 goto out_existing;
1520         spin_unlock(&ino->i_lock);
1521         new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1522         spin_lock(&ino->i_lock);
1523
1524         if (likely(nfsi->layout == NULL)) {     /* Won the race? */
1525                 nfsi->layout = new;
1526                 return new;
1527         } else if (new != NULL)
1528                 pnfs_free_layout_hdr(new);
1529 out_existing:
1530         pnfs_get_layout_hdr(nfsi->layout);
1531         return nfsi->layout;
1532 }
1533
1534 /*
1535  * iomode matching rules:
1536  * iomode       lseg    strict match
1537  *                      iomode
1538  * -----        -----   ------ -----
1539  * ANY          READ    N/A    true
1540  * ANY          RW      N/A    true
1541  * RW           READ    N/A    false
1542  * RW           RW      N/A    true
1543  * READ         READ    N/A    true
1544  * READ         RW      true   false
1545  * READ         RW      false  true
1546  */
1547 static bool
1548 pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1549                  const struct pnfs_layout_range *range,
1550                  bool strict_iomode)
1551 {
1552         struct pnfs_layout_range range1;
1553
1554         if ((range->iomode == IOMODE_RW &&
1555              ls_range->iomode != IOMODE_RW) ||
1556             (range->iomode != ls_range->iomode &&
1557              strict_iomode == true) ||
1558             !pnfs_lseg_range_intersecting(ls_range, range))
1559                 return 0;
1560
1561         /* range1 covers only the first byte in the range */
1562         range1 = *range;
1563         range1.length = 1;
1564         return pnfs_lseg_range_contained(ls_range, &range1);
1565 }
1566
1567 /*
1568  * lookup range in layout
1569  */
1570 static struct pnfs_layout_segment *
1571 pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1572                 struct pnfs_layout_range *range,
1573                 bool strict_iomode)
1574 {
1575         struct pnfs_layout_segment *lseg, *ret = NULL;
1576
1577         dprintk("%s:Begin\n", __func__);
1578
1579         list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1580                 if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1581                     !test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
1582                     pnfs_lseg_range_match(&lseg->pls_range, range,
1583                                           strict_iomode)) {
1584                         ret = pnfs_get_lseg(lseg);
1585                         break;
1586                 }
1587         }
1588
1589         dprintk("%s:Return lseg %p ref %d\n",
1590                 __func__, ret, ret ? atomic_read(&ret->pls_refcount) : 0);
1591         return ret;
1592 }
1593
1594 /*
1595  * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1596  * to the MDS or over pNFS
1597  *
1598  * The nfs_inode read_io and write_io fields are cumulative counters reset
1599  * when there are no layout segments. Note that in pnfs_update_layout iomode
1600  * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1601  * WRITE request.
1602  *
1603  * A return of true means use MDS I/O.
1604  *
1605  * From rfc 5661:
1606  * If a file's size is smaller than the file size threshold, data accesses
1607  * SHOULD be sent to the metadata server.  If an I/O request has a length that
1608  * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1609  * server.  If both file size and I/O size are provided, the client SHOULD
1610  * reach or exceed  both thresholds before sending its read or write
1611  * requests to the data server.
1612  */
1613 static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1614                                      struct inode *ino, int iomode)
1615 {
1616         struct nfs4_threshold *t = ctx->mdsthreshold;
1617         struct nfs_inode *nfsi = NFS_I(ino);
1618         loff_t fsize = i_size_read(ino);
1619         bool size = false, size_set = false, io = false, io_set = false, ret = false;
1620
1621         if (t == NULL)
1622                 return ret;
1623
1624         dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1625                 __func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1626
1627         switch (iomode) {
1628         case IOMODE_READ:
1629                 if (t->bm & THRESHOLD_RD) {
1630                         dprintk("%s fsize %llu\n", __func__, fsize);
1631                         size_set = true;
1632                         if (fsize < t->rd_sz)
1633                                 size = true;
1634                 }
1635                 if (t->bm & THRESHOLD_RD_IO) {
1636                         dprintk("%s nfsi->read_io %llu\n", __func__,
1637                                 nfsi->read_io);
1638                         io_set = true;
1639                         if (nfsi->read_io < t->rd_io_sz)
1640                                 io = true;
1641                 }
1642                 break;
1643         case IOMODE_RW:
1644                 if (t->bm & THRESHOLD_WR) {
1645                         dprintk("%s fsize %llu\n", __func__, fsize);
1646                         size_set = true;
1647                         if (fsize < t->wr_sz)
1648                                 size = true;
1649                 }
1650                 if (t->bm & THRESHOLD_WR_IO) {
1651                         dprintk("%s nfsi->write_io %llu\n", __func__,
1652                                 nfsi->write_io);
1653                         io_set = true;
1654                         if (nfsi->write_io < t->wr_io_sz)
1655                                 io = true;
1656                 }
1657                 break;
1658         }
1659         if (size_set && io_set) {
1660                 if (size && io)
1661                         ret = true;
1662         } else if (size || io)
1663                 ret = true;
1664
1665         dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1666         return ret;
1667 }
1668
1669 static bool pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
1670 {
1671         /*
1672          * send layoutcommit as it can hold up layoutreturn due to lseg
1673          * reference
1674          */
1675         pnfs_layoutcommit_inode(lo->plh_inode, false);
1676         return !wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
1677                                    nfs_wait_bit_killable,
1678                                    TASK_UNINTERRUPTIBLE);
1679 }
1680
1681 static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
1682 {
1683         unsigned long *bitlock = &lo->plh_flags;
1684
1685         clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
1686         smp_mb__after_atomic();
1687         wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
1688 }
1689
1690 /*
1691  * Layout segment is retreived from the server if not cached.
1692  * The appropriate layout segment is referenced and returned to the caller.
1693  */
1694 struct pnfs_layout_segment *
1695 pnfs_update_layout(struct inode *ino,
1696                    struct nfs_open_context *ctx,
1697                    loff_t pos,
1698                    u64 count,
1699                    enum pnfs_iomode iomode,
1700                    bool strict_iomode,
1701                    gfp_t gfp_flags)
1702 {
1703         struct pnfs_layout_range arg = {
1704                 .iomode = iomode,
1705                 .offset = pos,
1706                 .length = count,
1707         };
1708         unsigned pg_offset, seq;
1709         struct nfs_server *server = NFS_SERVER(ino);
1710         struct nfs_client *clp = server->nfs_client;
1711         struct pnfs_layout_hdr *lo = NULL;
1712         struct pnfs_layout_segment *lseg = NULL;
1713         nfs4_stateid stateid;
1714         long timeout = 0;
1715         unsigned long giveup = jiffies + (clp->cl_lease_time << 1);
1716         bool first;
1717
1718         if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
1719                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1720                                  PNFS_UPDATE_LAYOUT_NO_PNFS);
1721                 goto out;
1722         }
1723
1724         if (iomode == IOMODE_READ && i_size_read(ino) == 0) {
1725                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1726                                  PNFS_UPDATE_LAYOUT_RD_ZEROLEN);
1727                 goto out;
1728         }
1729
1730         if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
1731                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1732                                  PNFS_UPDATE_LAYOUT_MDSTHRESH);
1733                 goto out;
1734         }
1735
1736 lookup_again:
1737         nfs4_client_recover_expired_lease(clp);
1738         first = false;
1739         spin_lock(&ino->i_lock);
1740         lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
1741         if (lo == NULL) {
1742                 spin_unlock(&ino->i_lock);
1743                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1744                                  PNFS_UPDATE_LAYOUT_NOMEM);
1745                 goto out;
1746         }
1747
1748         /* Do we even need to bother with this? */
1749         if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1750                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1751                                  PNFS_UPDATE_LAYOUT_BULK_RECALL);
1752                 dprintk("%s matches recall, use MDS\n", __func__);
1753                 goto out_unlock;
1754         }
1755
1756         /* if LAYOUTGET already failed once we don't try again */
1757         if (pnfs_layout_io_test_failed(lo, iomode)) {
1758                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1759                                  PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
1760                 goto out_unlock;
1761         }
1762
1763         lseg = pnfs_find_lseg(lo, &arg, strict_iomode);
1764         if (lseg) {
1765                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1766                                 PNFS_UPDATE_LAYOUT_FOUND_CACHED);
1767                 goto out_unlock;
1768         }
1769
1770         if (!nfs4_valid_open_stateid(ctx->state)) {
1771                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1772                                 PNFS_UPDATE_LAYOUT_INVALID_OPEN);
1773                 goto out_unlock;
1774         }
1775
1776         /*
1777          * Choose a stateid for the LAYOUTGET. If we don't have a layout
1778          * stateid, or it has been invalidated, then we must use the open
1779          * stateid.
1780          */
1781         if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
1782
1783                 /*
1784                  * The first layoutget for the file. Need to serialize per
1785                  * RFC 5661 Errata 3208.
1786                  */
1787                 if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
1788                                      &lo->plh_flags)) {
1789                         spin_unlock(&ino->i_lock);
1790                         wait_on_bit(&lo->plh_flags, NFS_LAYOUT_FIRST_LAYOUTGET,
1791                                     TASK_UNINTERRUPTIBLE);
1792                         pnfs_put_layout_hdr(lo);
1793                         dprintk("%s retrying\n", __func__);
1794                         goto lookup_again;
1795                 }
1796
1797                 first = true;
1798                 do {
1799                         seq = read_seqbegin(&ctx->state->seqlock);
1800                         nfs4_stateid_copy(&stateid, &ctx->state->stateid);
1801                 } while (read_seqretry(&ctx->state->seqlock, seq));
1802         } else {
1803                 nfs4_stateid_copy(&stateid, &lo->plh_stateid);
1804         }
1805
1806         /*
1807          * Because we free lsegs before sending LAYOUTRETURN, we need to wait
1808          * for LAYOUTRETURN even if first is true.
1809          */
1810         if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1811                 spin_unlock(&ino->i_lock);
1812                 dprintk("%s wait for layoutreturn\n", __func__);
1813                 if (pnfs_prepare_to_retry_layoutget(lo)) {
1814                         if (first)
1815                                 pnfs_clear_first_layoutget(lo);
1816                         pnfs_put_layout_hdr(lo);
1817                         dprintk("%s retrying\n", __func__);
1818                         trace_pnfs_update_layout(ino, pos, count, iomode, lo,
1819                                         lseg, PNFS_UPDATE_LAYOUT_RETRY);
1820                         goto lookup_again;
1821                 }
1822                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1823                                 PNFS_UPDATE_LAYOUT_RETURN);
1824                 goto out_put_layout_hdr;
1825         }
1826
1827         if (pnfs_layoutgets_blocked(lo)) {
1828                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1829                                 PNFS_UPDATE_LAYOUT_BLOCKED);
1830                 goto out_unlock;
1831         }
1832         atomic_inc(&lo->plh_outstanding);
1833         spin_unlock(&ino->i_lock);
1834
1835         if (list_empty(&lo->plh_layouts)) {
1836                 /* The lo must be on the clp list if there is any
1837                  * chance of a CB_LAYOUTRECALL(FILE) coming in.
1838                  */
1839                 spin_lock(&clp->cl_lock);
1840                 if (list_empty(&lo->plh_layouts))
1841                         list_add_tail(&lo->plh_layouts, &server->layouts);
1842                 spin_unlock(&clp->cl_lock);
1843         }
1844
1845         pg_offset = arg.offset & ~PAGE_MASK;
1846         if (pg_offset) {
1847                 arg.offset -= pg_offset;
1848                 arg.length += pg_offset;
1849         }
1850         if (arg.length != NFS4_MAX_UINT64)
1851                 arg.length = PAGE_ALIGN(arg.length);
1852
1853         lseg = send_layoutget(lo, ctx, &stateid, &arg, &timeout, gfp_flags);
1854         trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1855                                  PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
1856         atomic_dec(&lo->plh_outstanding);
1857         if (IS_ERR(lseg)) {
1858                 switch(PTR_ERR(lseg)) {
1859                 case -EBUSY:
1860                         if (time_after(jiffies, giveup))
1861                                 lseg = NULL;
1862                         break;
1863                 case -ERECALLCONFLICT:
1864                         /* Huh? We hold no layouts, how is there a recall? */
1865                         if (first) {
1866                                 lseg = NULL;
1867                                 break;
1868                         }
1869                         /* Destroy the existing layout and start over */
1870                         if (time_after(jiffies, giveup))
1871                                 pnfs_destroy_layout(NFS_I(ino));
1872                         /* Fallthrough */
1873                 case -EAGAIN:
1874                         break;
1875                 default:
1876                         if (!nfs_error_is_fatal(PTR_ERR(lseg))) {
1877                                 pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
1878                                 lseg = NULL;
1879                         }
1880                         goto out_put_layout_hdr;
1881                 }
1882                 if (lseg) {
1883                         if (first)
1884                                 pnfs_clear_first_layoutget(lo);
1885                         trace_pnfs_update_layout(ino, pos, count,
1886                                 iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
1887                         pnfs_put_layout_hdr(lo);
1888                         goto lookup_again;
1889                 }
1890         } else {
1891                 pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
1892         }
1893
1894 out_put_layout_hdr:
1895         if (first)
1896                 pnfs_clear_first_layoutget(lo);
1897         pnfs_put_layout_hdr(lo);
1898 out:
1899         dprintk("%s: inode %s/%llu pNFS layout segment %s for "
1900                         "(%s, offset: %llu, length: %llu)\n",
1901                         __func__, ino->i_sb->s_id,
1902                         (unsigned long long)NFS_FILEID(ino),
1903                         IS_ERR_OR_NULL(lseg) ? "not found" : "found",
1904                         iomode==IOMODE_RW ?  "read/write" : "read-only",
1905                         (unsigned long long)pos,
1906                         (unsigned long long)count);
1907         return lseg;
1908 out_unlock:
1909         spin_unlock(&ino->i_lock);
1910         goto out_put_layout_hdr;
1911 }
1912 EXPORT_SYMBOL_GPL(pnfs_update_layout);
1913
1914 static bool
1915 pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
1916 {
1917         switch (range->iomode) {
1918         case IOMODE_READ:
1919         case IOMODE_RW:
1920                 break;
1921         default:
1922                 return false;
1923         }
1924         if (range->offset == NFS4_MAX_UINT64)
1925                 return false;
1926         if (range->length == 0)
1927                 return false;
1928         if (range->length != NFS4_MAX_UINT64 &&
1929             range->length > NFS4_MAX_UINT64 - range->offset)
1930                 return false;
1931         return true;
1932 }
1933
1934 struct pnfs_layout_segment *
1935 pnfs_layout_process(struct nfs4_layoutget *lgp)
1936 {
1937         struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
1938         struct nfs4_layoutget_res *res = &lgp->res;
1939         struct pnfs_layout_segment *lseg;
1940         struct inode *ino = lo->plh_inode;
1941         LIST_HEAD(free_me);
1942
1943         if (!pnfs_sanity_check_layout_range(&res->range))
1944                 return ERR_PTR(-EINVAL);
1945
1946         /* Inject layout blob into I/O device driver */
1947         lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
1948         if (IS_ERR_OR_NULL(lseg)) {
1949                 if (!lseg)
1950                         lseg = ERR_PTR(-ENOMEM);
1951
1952                 dprintk("%s: Could not allocate layout: error %ld\n",
1953                        __func__, PTR_ERR(lseg));
1954                 return lseg;
1955         }
1956
1957         pnfs_init_lseg(lo, lseg, &res->range, &res->stateid);
1958
1959         spin_lock(&ino->i_lock);
1960         if (pnfs_layoutgets_blocked(lo)) {
1961                 dprintk("%s forget reply due to state\n", __func__);
1962                 goto out_forget;
1963         }
1964
1965         if (!pnfs_layout_is_valid(lo)) {
1966                 /* We have a completely new layout */
1967                 pnfs_set_layout_stateid(lo, &res->stateid, true);
1968         } else if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
1969                 /* existing state ID, make sure the sequence number matches. */
1970                 if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
1971                         dprintk("%s forget reply due to sequence\n", __func__);
1972                         goto out_forget;
1973                 }
1974                 pnfs_set_layout_stateid(lo, &res->stateid, false);
1975         } else {
1976                 /*
1977                  * We got an entirely new state ID.  Mark all segments for the
1978                  * inode invalid, and retry the layoutget
1979                  */
1980                 pnfs_mark_layout_stateid_invalid(lo, &free_me);
1981                 goto out_forget;
1982         }
1983
1984         pnfs_get_lseg(lseg);
1985         pnfs_layout_insert_lseg(lo, lseg, &free_me);
1986
1987
1988         if (res->return_on_close)
1989                 set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
1990
1991         spin_unlock(&ino->i_lock);
1992         pnfs_free_lseg_list(&free_me);
1993         return lseg;
1994
1995 out_forget:
1996         spin_unlock(&ino->i_lock);
1997         lseg->pls_layout = lo;
1998         NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
1999         if (!pnfs_layout_is_valid(lo))
2000                 nfs_commit_inode(ino, 0);
2001         return ERR_PTR(-EAGAIN);
2002 }
2003
2004 /**
2005  * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
2006  * @lo: pointer to layout header
2007  * @tmp_list: list header to be used with pnfs_free_lseg_list()
2008  * @return_range: describe layout segment ranges to be returned
2009  *
2010  * This function is mainly intended for use by layoutrecall. It attempts
2011  * to free the layout segment immediately, or else to mark it for return
2012  * as soon as its reference count drops to zero.
2013  */
2014 int
2015 pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
2016                                 struct list_head *tmp_list,
2017                                 const struct pnfs_layout_range *return_range,
2018                                 u32 seq)
2019 {
2020         struct pnfs_layout_segment *lseg, *next;
2021         int remaining = 0;
2022
2023         dprintk("%s:Begin lo %p\n", __func__, lo);
2024
2025         if (list_empty(&lo->plh_segs))
2026                 return 0;
2027
2028         assert_spin_locked(&lo->plh_inode->i_lock);
2029
2030         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
2031                 if (pnfs_match_lseg_recall(lseg, return_range, seq)) {
2032                         dprintk("%s: marking lseg %p iomode %d "
2033                                 "offset %llu length %llu\n", __func__,
2034                                 lseg, lseg->pls_range.iomode,
2035                                 lseg->pls_range.offset,
2036                                 lseg->pls_range.length);
2037                         if (mark_lseg_invalid(lseg, tmp_list))
2038                                 continue;
2039                         remaining++;
2040                         set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
2041                 }
2042
2043         if (remaining)
2044                 pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2045
2046         return remaining;
2047 }
2048
2049 void pnfs_error_mark_layout_for_return(struct inode *inode,
2050                                        struct pnfs_layout_segment *lseg)
2051 {
2052         struct pnfs_layout_hdr *lo = NFS_I(inode)->layout;
2053         struct pnfs_layout_range range = {
2054                 .iomode = lseg->pls_range.iomode,
2055                 .offset = 0,
2056                 .length = NFS4_MAX_UINT64,
2057         };
2058         bool return_now = false;
2059
2060         spin_lock(&inode->i_lock);
2061         if (!pnfs_layout_is_valid(lo)) {
2062                 spin_unlock(&inode->i_lock);
2063                 return;
2064         }
2065         pnfs_set_plh_return_info(lo, range.iomode, 0);
2066         /*
2067          * mark all matching lsegs so that we are sure to have no live
2068          * segments at hand when sending layoutreturn. See pnfs_put_lseg()
2069          * for how it works.
2070          */
2071         if (!pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs, &range, 0)) {
2072                 nfs4_stateid stateid;
2073                 enum pnfs_iomode iomode;
2074
2075                 return_now = pnfs_prepare_layoutreturn(lo, &stateid, &iomode);
2076                 spin_unlock(&inode->i_lock);
2077                 if (return_now)
2078                         pnfs_send_layoutreturn(lo, &stateid, iomode, false);
2079         } else {
2080                 spin_unlock(&inode->i_lock);
2081                 nfs_commit_inode(inode, 0);
2082         }
2083 }
2084 EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
2085
2086 void
2087 pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor *pgio)
2088 {
2089         if (pgio->pg_lseg == NULL ||
2090             test_bit(NFS_LSEG_VALID, &pgio->pg_lseg->pls_flags))
2091                 return;
2092         pnfs_put_lseg(pgio->pg_lseg);
2093         pgio->pg_lseg = NULL;
2094 }
2095 EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_layout);
2096
2097 /*
2098  * Check for any intersection between the request and the pgio->pg_lseg,
2099  * and if none, put this pgio->pg_lseg away.
2100  */
2101 static void
2102 pnfs_generic_pg_check_range(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2103 {
2104         if (pgio->pg_lseg && !pnfs_lseg_request_intersecting(pgio->pg_lseg, req)) {
2105                 pnfs_put_lseg(pgio->pg_lseg);
2106                 pgio->pg_lseg = NULL;
2107         }
2108 }
2109
2110 void
2111 pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2112 {
2113         u64 rd_size = req->wb_bytes;
2114
2115         pnfs_generic_pg_check_layout(pgio);
2116         pnfs_generic_pg_check_range(pgio, req);
2117         if (pgio->pg_lseg == NULL) {
2118                 if (pgio->pg_dreq == NULL)
2119                         rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
2120                 else
2121                         rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
2122
2123                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
2124                                                    req->wb_context,
2125                                                    req_offset(req),
2126                                                    rd_size,
2127                                                    IOMODE_READ,
2128                                                    false,
2129                                                    GFP_KERNEL);
2130                 if (IS_ERR(pgio->pg_lseg)) {
2131                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2132                         pgio->pg_lseg = NULL;
2133                         return;
2134                 }
2135         }
2136         /* If no lseg, fall back to read through mds */
2137         if (pgio->pg_lseg == NULL)
2138                 nfs_pageio_reset_read_mds(pgio);
2139
2140 }
2141 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
2142
2143 void
2144 pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
2145                            struct nfs_page *req, u64 wb_size)
2146 {
2147         pnfs_generic_pg_check_layout(pgio);
2148         pnfs_generic_pg_check_range(pgio, req);
2149         if (pgio->pg_lseg == NULL) {
2150                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
2151                                                    req->wb_context,
2152                                                    req_offset(req),
2153                                                    wb_size,
2154                                                    IOMODE_RW,
2155                                                    false,
2156                                                    GFP_NOFS);
2157                 if (IS_ERR(pgio->pg_lseg)) {
2158                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2159                         pgio->pg_lseg = NULL;
2160                         return;
2161                 }
2162         }
2163         /* If no lseg, fall back to write through mds */
2164         if (pgio->pg_lseg == NULL)
2165                 nfs_pageio_reset_write_mds(pgio);
2166 }
2167 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
2168
2169 void
2170 pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
2171 {
2172         if (desc->pg_lseg) {
2173                 pnfs_put_lseg(desc->pg_lseg);
2174                 desc->pg_lseg = NULL;
2175         }
2176 }
2177 EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
2178
2179 /*
2180  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
2181  * of bytes (maximum @req->wb_bytes) that can be coalesced.
2182  */
2183 size_t
2184 pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
2185                      struct nfs_page *prev, struct nfs_page *req)
2186 {
2187         unsigned int size;
2188         u64 seg_end, req_start, seg_left;
2189
2190         size = nfs_generic_pg_test(pgio, prev, req);
2191         if (!size)
2192                 return 0;
2193
2194         /*
2195          * 'size' contains the number of bytes left in the current page (up
2196          * to the original size asked for in @req->wb_bytes).
2197          *
2198          * Calculate how many bytes are left in the layout segment
2199          * and if there are less bytes than 'size', return that instead.
2200          *
2201          * Please also note that 'end_offset' is actually the offset of the
2202          * first byte that lies outside the pnfs_layout_range. FIXME?
2203          *
2204          */
2205         if (pgio->pg_lseg) {
2206                 seg_end = pnfs_end_offset(pgio->pg_lseg->pls_range.offset,
2207                                      pgio->pg_lseg->pls_range.length);
2208                 req_start = req_offset(req);
2209
2210                 /* start of request is past the last byte of this segment */
2211                 if (req_start >= seg_end)
2212                         return 0;
2213
2214                 /* adjust 'size' iff there are fewer bytes left in the
2215                  * segment than what nfs_generic_pg_test returned */
2216                 seg_left = seg_end - req_start;
2217                 if (seg_left < size)
2218                         size = (unsigned int)seg_left;
2219         }
2220
2221         return size;
2222 }
2223 EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
2224
2225 int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
2226 {
2227         struct nfs_pageio_descriptor pgio;
2228
2229         /* Resend all requests through the MDS */
2230         nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
2231                               hdr->completion_ops);
2232         set_bit(NFS_CONTEXT_RESEND_WRITES, &hdr->args.context->flags);
2233         return nfs_pageio_resend(&pgio, hdr);
2234 }
2235 EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
2236
2237 static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
2238 {
2239
2240         dprintk("pnfs write error = %d\n", hdr->pnfs_error);
2241         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2242             PNFS_LAYOUTRET_ON_ERROR) {
2243                 pnfs_return_layout(hdr->inode);
2244         }
2245         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2246                 hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
2247 }
2248
2249 /*
2250  * Called by non rpc-based layout drivers
2251  */
2252 void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
2253 {
2254         if (likely(!hdr->pnfs_error)) {
2255                 pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
2256                                 hdr->mds_offset + hdr->res.count);
2257                 hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2258         }
2259         trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
2260         if (unlikely(hdr->pnfs_error))
2261                 pnfs_ld_handle_write_error(hdr);
2262         hdr->mds_ops->rpc_release(hdr);
2263 }
2264 EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
2265
2266 static void
2267 pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
2268                 struct nfs_pgio_header *hdr)
2269 {
2270         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2271
2272         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2273                 list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2274                 nfs_pageio_reset_write_mds(desc);
2275                 mirror->pg_recoalesce = 1;
2276         }
2277         nfs_pgio_data_destroy(hdr);
2278         hdr->release(hdr);
2279 }
2280
2281 static enum pnfs_try_status
2282 pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
2283                         const struct rpc_call_ops *call_ops,
2284                         struct pnfs_layout_segment *lseg,
2285                         int how)
2286 {
2287         struct inode *inode = hdr->inode;
2288         enum pnfs_try_status trypnfs;
2289         struct nfs_server *nfss = NFS_SERVER(inode);
2290
2291         hdr->mds_ops = call_ops;
2292
2293         dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
2294                 inode->i_ino, hdr->args.count, hdr->args.offset, how);
2295         trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
2296         if (trypnfs != PNFS_NOT_ATTEMPTED)
2297                 nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
2298         dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2299         return trypnfs;
2300 }
2301
2302 static void
2303 pnfs_do_write(struct nfs_pageio_descriptor *desc,
2304               struct nfs_pgio_header *hdr, int how)
2305 {
2306         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2307         struct pnfs_layout_segment *lseg = desc->pg_lseg;
2308         enum pnfs_try_status trypnfs;
2309
2310         trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
2311         switch (trypnfs) {
2312         case PNFS_NOT_ATTEMPTED:
2313                 pnfs_write_through_mds(desc, hdr);
2314         case PNFS_ATTEMPTED:
2315                 break;
2316         case PNFS_TRY_AGAIN:
2317                 /* cleanup hdr and prepare to redo pnfs */
2318                 if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2319                         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2320                         list_splice_init(&hdr->pages, &mirror->pg_list);
2321                         mirror->pg_recoalesce = 1;
2322                 }
2323                 hdr->mds_ops->rpc_release(hdr);
2324         }
2325 }
2326
2327 static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
2328 {
2329         pnfs_put_lseg(hdr->lseg);
2330         nfs_pgio_header_free(hdr);
2331 }
2332
2333 int
2334 pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
2335 {
2336         struct nfs_pgio_header *hdr;
2337         int ret;
2338
2339         hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2340         if (!hdr) {
2341                 desc->pg_error = -ENOMEM;
2342                 return desc->pg_error;
2343         }
2344         nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
2345
2346         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2347         ret = nfs_generic_pgio(desc, hdr);
2348         if (!ret)
2349                 pnfs_do_write(desc, hdr, desc->pg_ioflags);
2350
2351         return ret;
2352 }
2353 EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
2354
2355 int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
2356 {
2357         struct nfs_pageio_descriptor pgio;
2358
2359         /* Resend all requests through the MDS */
2360         nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
2361         return nfs_pageio_resend(&pgio, hdr);
2362 }
2363 EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
2364
2365 static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
2366 {
2367         dprintk("pnfs read error = %d\n", hdr->pnfs_error);
2368         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2369             PNFS_LAYOUTRET_ON_ERROR) {
2370                 pnfs_return_layout(hdr->inode);
2371         }
2372         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2373                 hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
2374 }
2375
2376 /*
2377  * Called by non rpc-based layout drivers
2378  */
2379 void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
2380 {
2381         if (likely(!hdr->pnfs_error))
2382                 hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2383         trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
2384         if (unlikely(hdr->pnfs_error))
2385                 pnfs_ld_handle_read_error(hdr);
2386         hdr->mds_ops->rpc_release(hdr);
2387 }
2388 EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
2389
2390 static void
2391 pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
2392                 struct nfs_pgio_header *hdr)
2393 {
2394         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2395
2396         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2397                 list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2398                 nfs_pageio_reset_read_mds(desc);
2399                 mirror->pg_recoalesce = 1;
2400         }
2401         nfs_pgio_data_destroy(hdr);
2402         hdr->release(hdr);
2403 }
2404
2405 /*
2406  * Call the appropriate parallel I/O subsystem read function.
2407  */
2408 static enum pnfs_try_status
2409 pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
2410                        const struct rpc_call_ops *call_ops,
2411                        struct pnfs_layout_segment *lseg)
2412 {
2413         struct inode *inode = hdr->inode;
2414         struct nfs_server *nfss = NFS_SERVER(inode);
2415         enum pnfs_try_status trypnfs;
2416
2417         hdr->mds_ops = call_ops;
2418
2419         dprintk("%s: Reading ino:%lu %u@%llu\n",
2420                 __func__, inode->i_ino, hdr->args.count, hdr->args.offset);
2421
2422         trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
2423         if (trypnfs != PNFS_NOT_ATTEMPTED)
2424                 nfs_inc_stats(inode, NFSIOS_PNFS_READ);
2425         dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2426         return trypnfs;
2427 }
2428
2429 /* Resend all requests through pnfs. */
2430 void pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr)
2431 {
2432         struct nfs_pageio_descriptor pgio;
2433
2434         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2435                 /* Prevent deadlocks with layoutreturn! */
2436                 pnfs_put_lseg(hdr->lseg);
2437                 hdr->lseg = NULL;
2438
2439                 nfs_pageio_init_read(&pgio, hdr->inode, false,
2440                                         hdr->completion_ops);
2441                 hdr->task.tk_status = nfs_pageio_resend(&pgio, hdr);
2442         }
2443 }
2444 EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
2445
2446 static void
2447 pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
2448 {
2449         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2450         struct pnfs_layout_segment *lseg = desc->pg_lseg;
2451         enum pnfs_try_status trypnfs;
2452
2453         trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
2454         switch (trypnfs) {
2455         case PNFS_NOT_ATTEMPTED:
2456                 pnfs_read_through_mds(desc, hdr);
2457         case PNFS_ATTEMPTED:
2458                 break;
2459         case PNFS_TRY_AGAIN:
2460                 /* cleanup hdr and prepare to redo pnfs */
2461                 if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2462                         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2463                         list_splice_init(&hdr->pages, &mirror->pg_list);
2464                         mirror->pg_recoalesce = 1;
2465                 }
2466                 hdr->mds_ops->rpc_release(hdr);
2467         }
2468 }
2469
2470 static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
2471 {
2472         pnfs_put_lseg(hdr->lseg);
2473         nfs_pgio_header_free(hdr);
2474 }
2475
2476 int
2477 pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
2478 {
2479         struct nfs_pgio_header *hdr;
2480         int ret;
2481
2482         hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2483         if (!hdr) {
2484                 desc->pg_error = -ENOMEM;
2485                 return desc->pg_error;
2486         }
2487         nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
2488         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2489         ret = nfs_generic_pgio(desc, hdr);
2490         if (!ret)
2491                 pnfs_do_read(desc, hdr);
2492         return ret;
2493 }
2494 EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
2495
2496 static void pnfs_clear_layoutcommitting(struct inode *inode)
2497 {
2498         unsigned long *bitlock = &NFS_I(inode)->flags;
2499
2500         clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
2501         smp_mb__after_atomic();
2502         wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
2503 }
2504
2505 /*
2506  * There can be multiple RW segments.
2507  */
2508 static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
2509 {
2510         struct pnfs_layout_segment *lseg;
2511
2512         list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
2513                 if (lseg->pls_range.iomode == IOMODE_RW &&
2514                     test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
2515                         list_add(&lseg->pls_lc_list, listp);
2516         }
2517 }
2518
2519 static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
2520 {
2521         struct pnfs_layout_segment *lseg, *tmp;
2522
2523         /* Matched by references in pnfs_set_layoutcommit */
2524         list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
2525                 list_del_init(&lseg->pls_lc_list);
2526                 pnfs_put_lseg(lseg);
2527         }
2528
2529         pnfs_clear_layoutcommitting(inode);
2530 }
2531
2532 void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
2533 {
2534         pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
2535 }
2536 EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
2537
2538 void
2539 pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
2540                 loff_t end_pos)
2541 {
2542         struct nfs_inode *nfsi = NFS_I(inode);
2543         bool mark_as_dirty = false;
2544
2545         spin_lock(&inode->i_lock);
2546         if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
2547                 nfsi->layout->plh_lwb = end_pos;
2548                 mark_as_dirty = true;
2549                 dprintk("%s: Set layoutcommit for inode %lu ",
2550                         __func__, inode->i_ino);
2551         } else if (end_pos > nfsi->layout->plh_lwb)
2552                 nfsi->layout->plh_lwb = end_pos;
2553         if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
2554                 /* references matched in nfs4_layoutcommit_release */
2555                 pnfs_get_lseg(lseg);
2556         }
2557         spin_unlock(&inode->i_lock);
2558         dprintk("%s: lseg %p end_pos %llu\n",
2559                 __func__, lseg, nfsi->layout->plh_lwb);
2560
2561         /* if pnfs_layoutcommit_inode() runs between inode locks, the next one
2562          * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
2563         if (mark_as_dirty)
2564                 mark_inode_dirty_sync(inode);
2565 }
2566 EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
2567
2568 void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
2569 {
2570         struct nfs_server *nfss = NFS_SERVER(data->args.inode);
2571
2572         if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
2573                 nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
2574         pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
2575 }
2576
2577 /*
2578  * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
2579  * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
2580  * data to disk to allow the server to recover the data if it crashes.
2581  * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
2582  * is off, and a COMMIT is sent to a data server, or
2583  * if WRITEs to a data server return NFS_DATA_SYNC.
2584  */
2585 int
2586 pnfs_layoutcommit_inode(struct inode *inode, bool sync)
2587 {
2588         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2589         struct nfs4_layoutcommit_data *data;
2590         struct nfs_inode *nfsi = NFS_I(inode);
2591         loff_t end_pos;
2592         int status;
2593
2594         if (!pnfs_layoutcommit_outstanding(inode))
2595                 return 0;
2596
2597         dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
2598
2599         status = -EAGAIN;
2600         if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
2601                 if (!sync)
2602                         goto out;
2603                 status = wait_on_bit_lock_action(&nfsi->flags,
2604                                 NFS_INO_LAYOUTCOMMITTING,
2605                                 nfs_wait_bit_killable,
2606                                 TASK_KILLABLE);
2607                 if (status)
2608                         goto out;
2609         }
2610
2611         status = -ENOMEM;
2612         /* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
2613         data = kzalloc(sizeof(*data), GFP_NOFS);
2614         if (!data)
2615                 goto clear_layoutcommitting;
2616
2617         status = 0;
2618         spin_lock(&inode->i_lock);
2619         if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
2620                 goto out_unlock;
2621
2622         INIT_LIST_HEAD(&data->lseg_list);
2623         pnfs_list_write_lseg(inode, &data->lseg_list);
2624
2625         end_pos = nfsi->layout->plh_lwb;
2626
2627         nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
2628         spin_unlock(&inode->i_lock);
2629
2630         data->args.inode = inode;
2631         data->cred = get_rpccred(nfsi->layout->plh_lc_cred);
2632         nfs_fattr_init(&data->fattr);
2633         data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
2634         data->res.fattr = &data->fattr;
2635         if (end_pos != 0)
2636                 data->args.lastbytewritten = end_pos - 1;
2637         else
2638                 data->args.lastbytewritten = U64_MAX;
2639         data->res.server = NFS_SERVER(inode);
2640
2641         if (ld->prepare_layoutcommit) {
2642                 status = ld->prepare_layoutcommit(&data->args);
2643                 if (status) {
2644                         put_rpccred(data->cred);
2645                         spin_lock(&inode->i_lock);
2646                         set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
2647                         if (end_pos > nfsi->layout->plh_lwb)
2648                                 nfsi->layout->plh_lwb = end_pos;
2649                         goto out_unlock;
2650                 }
2651         }
2652
2653
2654         status = nfs4_proc_layoutcommit(data, sync);
2655 out:
2656         if (status)
2657                 mark_inode_dirty_sync(inode);
2658         dprintk("<-- %s status %d\n", __func__, status);
2659         return status;
2660 out_unlock:
2661         spin_unlock(&inode->i_lock);
2662         kfree(data);
2663 clear_layoutcommitting:
2664         pnfs_clear_layoutcommitting(inode);
2665         goto out;
2666 }
2667 EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
2668
2669 int
2670 pnfs_generic_sync(struct inode *inode, bool datasync)
2671 {
2672         return pnfs_layoutcommit_inode(inode, true);
2673 }
2674 EXPORT_SYMBOL_GPL(pnfs_generic_sync);
2675
2676 struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
2677 {
2678         struct nfs4_threshold *thp;
2679
2680         thp = kzalloc(sizeof(*thp), GFP_NOFS);
2681         if (!thp) {
2682                 dprintk("%s mdsthreshold allocation failed\n", __func__);
2683                 return NULL;
2684         }
2685         return thp;
2686 }
2687
2688 #if IS_ENABLED(CONFIG_NFS_V4_2)
2689 int
2690 pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
2691 {
2692         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2693         struct nfs_server *server = NFS_SERVER(inode);
2694         struct nfs_inode *nfsi = NFS_I(inode);
2695         struct nfs42_layoutstat_data *data;
2696         struct pnfs_layout_hdr *hdr;
2697         int status = 0;
2698
2699         if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
2700                 goto out;
2701
2702         if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
2703                 goto out;
2704
2705         if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
2706                 goto out;
2707
2708         spin_lock(&inode->i_lock);
2709         if (!NFS_I(inode)->layout) {
2710                 spin_unlock(&inode->i_lock);
2711                 goto out_clear_layoutstats;
2712         }
2713         hdr = NFS_I(inode)->layout;
2714         pnfs_get_layout_hdr(hdr);
2715         spin_unlock(&inode->i_lock);
2716
2717         data = kzalloc(sizeof(*data), gfp_flags);
2718         if (!data) {
2719                 status = -ENOMEM;
2720                 goto out_put;
2721         }
2722
2723         data->args.fh = NFS_FH(inode);
2724         data->args.inode = inode;
2725         status = ld->prepare_layoutstats(&data->args);
2726         if (status)
2727                 goto out_free;
2728
2729         status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
2730
2731 out:
2732         dprintk("%s returns %d\n", __func__, status);
2733         return status;
2734
2735 out_free:
2736         kfree(data);
2737 out_put:
2738         pnfs_put_layout_hdr(hdr);
2739 out_clear_layoutstats:
2740         smp_mb__before_atomic();
2741         clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
2742         smp_mb__after_atomic();
2743         goto out;
2744 }
2745 EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
2746 #endif
2747
2748 unsigned int layoutstats_timer;
2749 module_param(layoutstats_timer, uint, 0644);
2750 EXPORT_SYMBOL_GPL(layoutstats_timer);