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 "internal.h"
  34 #include "pnfs.h"
  35 #include "iostat.h"
  36 #include "nfs4trace.h"
  37 #include "delegation.h"
  38 #include "nfs42.h"
  39
  40 #define NFSDBG_FACILITY         NFSDBG_PNFS
  41 #define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
  42
  43 /* Locking:
  44  *
  45  * pnfs_spinlock:
  46  *      protects pnfs_modules_tbl.
  47  */
  48 static DEFINE_SPINLOCK(pnfs_spinlock);
  49
  50 /*
  51  * pnfs_modules_tbl holds all pnfs modules
  52  */
  53 static LIST_HEAD(pnfs_modules_tbl);
  54
  55 static int
  56 pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo, nfs4_stateid stateid,
  57                        enum pnfs_iomode iomode, bool sync);
  58
  59 /* Return the registered pnfs layout driver module matching given id */
  60 static struct pnfs_layoutdriver_type *
  61 find_pnfs_driver_locked(u32 id)
  62 {
  63         struct pnfs_layoutdriver_type *local;
  64
  65         list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
  66                 if (local->id == id)
  67                         goto out;
  68         local = NULL;
  69 out:
  70         dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
  71         return local;
  72 }
  73
  74 static struct pnfs_layoutdriver_type *
  75 find_pnfs_driver(u32 id)
  76 {
  77         struct pnfs_layoutdriver_type *local;
  78
  79         spin_lock(&pnfs_spinlock);
  80         local = find_pnfs_driver_locked(id);
  81         if (local != NULL && !try_module_get(local->owner)) {
  82                 dprintk("%s: Could not grab reference on module\n", __func__);
  83                 local = NULL;
  84         }
  85         spin_unlock(&pnfs_spinlock);
  86         return local;
  87 }
  88
  89 void
  90 unset_pnfs_layoutdriver(struct nfs_server *nfss)
  91 {
  92         if (nfss->pnfs_curr_ld) {
  93                 if (nfss->pnfs_curr_ld->clear_layoutdriver)
  94                         nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
  95                 /* Decrement the MDS count. Purge the deviceid cache if zero */
  96                 if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
  97                         nfs4_deviceid_purge_client(nfss->nfs_client);
  98                 module_put(nfss->pnfs_curr_ld->owner);
  99         }
 100         nfss->pnfs_curr_ld = NULL;
 101 }
 102
 103 /*
 104  * Try to set the server's pnfs module to the pnfs layout type specified by id.
 105  * Currently only one pNFS layout driver per filesystem is supported.
 106  *
 107  * @id layout type. Zero (illegal layout type) indicates pNFS not in use.
 108  */
 109 void
 110 set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
 111                       u32 id)
 112 {
 113         struct pnfs_layoutdriver_type *ld_type = NULL;
 114
 115         if (id == 0)
 116                 goto out_no_driver;
 117         if (!(server->nfs_client->cl_exchange_flags &
 118                  (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
 119                 printk(KERN_ERR "NFS: %s: id %u cl_exchange_flags 0x%x\n",
 120                         __func__, id, server->nfs_client->cl_exchange_flags);
 121                 goto out_no_driver;
 122         }
 123         ld_type = find_pnfs_driver(id);
 124         if (!ld_type) {
 125                 request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id);
 126                 ld_type = find_pnfs_driver(id);
 127                 if (!ld_type) {
 128                         dprintk("%s: No pNFS module found for %u.\n",
 129                                 __func__, id);
 130                         goto out_no_driver;
 131                 }
 132         }
 133         server->pnfs_curr_ld = ld_type;
 134         if (ld_type->set_layoutdriver
 135             && ld_type->set_layoutdriver(server, mntfh)) {
 136                 printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
 137                         "driver %u.\n", __func__, id);
 138                 module_put(ld_type->owner);
 139                 goto out_no_driver;
 140         }
 141         /* Bump the MDS count */
 142         atomic_inc(&server->nfs_client->cl_mds_count);
 143
 144         dprintk("%s: pNFS module for %u set\n", __func__, id);
 145         return;
 146
 147 out_no_driver:
 148         dprintk("%s: Using NFSv4 I/O\n", __func__);
 149         server->pnfs_curr_ld = NULL;
 150 }
 151
 152 int
 153 pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 154 {
 155         int status = -EINVAL;
 156         struct pnfs_layoutdriver_type *tmp;
 157
 158         if (ld_type->id == 0) {
 159                 printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
 160                 return status;
 161         }
 162         if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
 163                 printk(KERN_ERR "NFS: %s Layout driver must provide "
 164                        "alloc_lseg and free_lseg.\n", __func__);
 165                 return status;
 166         }
 167
 168         spin_lock(&pnfs_spinlock);
 169         tmp = find_pnfs_driver_locked(ld_type->id);
 170         if (!tmp) {
 171                 list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
 172                 status = 0;
 173                 dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
 174                         ld_type->name);
 175         } else {
 176                 printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
 177                         __func__, ld_type->id);
 178         }
 179         spin_unlock(&pnfs_spinlock);
 180
 181         return status;
 182 }
 183 EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
 184
 185 void
 186 pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 187 {
 188         dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
 189         spin_lock(&pnfs_spinlock);
 190         list_del(&ld_type->pnfs_tblid);
 191         spin_unlock(&pnfs_spinlock);
 192 }
 193 EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
 194
 195 /*
 196  * pNFS client layout cache
 197  */
 198
 199 /* Need to hold i_lock if caller does not already hold reference */
 200 void
 201 pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
 202 {
 203         atomic_inc(&lo->plh_refcount);
 204 }
 205
 206 static struct pnfs_layout_hdr *
 207 pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
 208 {
 209         struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
 210         return ld->alloc_layout_hdr(ino, gfp_flags);
 211 }
 212
 213 static void
 214 pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
 215 {
 216         struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 217         struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
 218
 219         if (!list_empty(&lo->plh_layouts)) {
 220                 struct nfs_client *clp = server->nfs_client;
 221
 222                 spin_lock(&clp->cl_lock);
 223                 list_del_init(&lo->plh_layouts);
 224                 spin_unlock(&clp->cl_lock);
 225         }
 226         put_rpccred(lo->plh_lc_cred);
 227         return ld->free_layout_hdr(lo);
 228 }
 229
 230 static void
 231 pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 232 {
 233         struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
 234         dprintk("%s: freeing layout cache %p\n", __func__, lo);
 235         nfsi->layout = NULL;
 236         /* Reset MDS Threshold I/O counters */
 237         nfsi->write_io = 0;
 238         nfsi->read_io = 0;
 239 }
 240
 241 void
 242 pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
 243 {
 244         struct inode *inode = lo->plh_inode;
 245
 246         if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
 247                 if (!list_empty(&lo->plh_segs))
 248                         WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n");
 249                 pnfs_detach_layout_hdr(lo);
 250                 spin_unlock(&inode->i_lock);
 251                 pnfs_free_layout_hdr(lo);
 252         }
 253 }
 254
 255 static int
 256 pnfs_iomode_to_fail_bit(u32 iomode)
 257 {
 258         return iomode == IOMODE_RW ?
 259                 NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 260 }
 261
 262 static void
 263 pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 264 {
 265         lo->plh_retry_timestamp = jiffies;
 266         if (!test_and_set_bit(fail_bit, &lo->plh_flags))
 267                 atomic_inc(&lo->plh_refcount);
 268 }
 269
 270 static void
 271 pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 272 {
 273         if (test_and_clear_bit(fail_bit, &lo->plh_flags))
 274                 atomic_dec(&lo->plh_refcount);
 275 }
 276
 277 static void
 278 pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 279 {
 280         struct inode *inode = lo->plh_inode;
 281         struct pnfs_layout_range range = {
 282                 .iomode = iomode,
 283                 .offset = 0,
 284                 .length = NFS4_MAX_UINT64,
 285         };
 286         LIST_HEAD(head);
 287
 288         spin_lock(&inode->i_lock);
 289         pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
 290         pnfs_mark_matching_lsegs_invalid(lo, &head, &range);
 291         spin_unlock(&inode->i_lock);
 292         pnfs_free_lseg_list(&head);
 293         dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
 294                         iomode == IOMODE_RW ?  "RW" : "READ");
 295 }
 296
 297 static bool
 298 pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 299 {
 300         unsigned long start, end;
 301         int fail_bit = pnfs_iomode_to_fail_bit(iomode);
 302
 303         if (test_bit(fail_bit, &lo->plh_flags) == 0)
 304                 return false;
 305         end = jiffies;
 306         start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
 307         if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
 308                 /* It is time to retry the failed layoutgets */
 309                 pnfs_layout_clear_fail_bit(lo, fail_bit);
 310                 return false;
 311         }
 312         return true;
 313 }
 314
 315 static void
 316 init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg)
 317 {
 318         INIT_LIST_HEAD(&lseg->pls_list);
 319         INIT_LIST_HEAD(&lseg->pls_lc_list);
 320         atomic_set(&lseg->pls_refcount, 1);
 321         smp_mb();
 322         set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
 323         lseg->pls_layout = lo;
 324 }
 325
 326 static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
 327 {
 328         struct inode *ino = lseg->pls_layout->plh_inode;
 329
 330         NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
 331 }
 332
 333 static void
 334 pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 335                 struct pnfs_layout_segment *lseg)
 336 {
 337         struct inode *inode = lo->plh_inode;
 338
 339         WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 340         list_del_init(&lseg->pls_list);
 341         /* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 342         atomic_dec(&lo->plh_refcount);
 343         if (list_empty(&lo->plh_segs))
 344                 clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 345         rpc_wake_up(&NFS_SERVER(inode)->roc_rpcwaitq);
 346 }
 347
 348 /* Return true if layoutreturn is needed */
 349 static bool
 350 pnfs_layout_need_return(struct pnfs_layout_hdr *lo,
 351                         struct pnfs_layout_segment *lseg)
 352 {
 353         struct pnfs_layout_segment *s;
 354
 355         if (!test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 356                 return false;
 357
 358         list_for_each_entry(s, &lo->plh_segs, pls_list)
 359                 if (s != lseg && test_bit(NFS_LSEG_LAYOUTRETURN, &s->pls_flags))
 360                         return false;
 361
 362         return true;
 363 }
 364
 365 static bool
 366 pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo)
 367 {
 368         if (test_and_set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
 369                 return false;
 370         lo->plh_return_iomode = 0;
 371         pnfs_get_layout_hdr(lo);
 372         clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE, &lo->plh_flags);
 373         return true;
 374 }
 375
 376 static void pnfs_layoutreturn_before_put_lseg(struct pnfs_layout_segment *lseg,
 377                 struct pnfs_layout_hdr *lo, struct inode *inode)
 378 {
 379         lo = lseg->pls_layout;
 380         inode = lo->plh_inode;
 381
 382         spin_lock(&inode->i_lock);
 383         if (pnfs_layout_need_return(lo, lseg)) {
 384                 nfs4_stateid stateid;
 385                 enum pnfs_iomode iomode;
 386                 bool send;
 387
 388                 stateid = lo->plh_stateid;
 389                 iomode = lo->plh_return_iomode;
 390                 send = pnfs_prepare_layoutreturn(lo);
 391                 spin_unlock(&inode->i_lock);
 392                 if (send) {
 393                         /* Send an async layoutreturn so we dont deadlock */
 394                         pnfs_send_layoutreturn(lo, stateid, iomode, false);
 395                 }
 396         } else
 397                 spin_unlock(&inode->i_lock);
 398 }
 399
 400 void
 401 pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 402 {
 403         struct pnfs_layout_hdr *lo;
 404         struct inode *inode;
 405
 406         if (!lseg)
 407                 return;
 408
 409         dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 410                 atomic_read(&lseg->pls_refcount),
 411                 test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 412
 413         /* Handle the case where refcount != 1 */
 414         if (atomic_add_unless(&lseg->pls_refcount, -1, 1))
 415                 return;
 416
 417         lo = lseg->pls_layout;
 418         inode = lo->plh_inode;
 419         /* Do we need a layoutreturn? */
 420         if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 421                 pnfs_layoutreturn_before_put_lseg(lseg, lo, inode);
 422
 423         if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
 424                 if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 425                         spin_unlock(&inode->i_lock);
 426                         return;
 427                 }
 428                 pnfs_get_layout_hdr(lo);
 429                 pnfs_layout_remove_lseg(lo, lseg);
 430                 spin_unlock(&inode->i_lock);
 431                 pnfs_free_lseg(lseg);
 432                 pnfs_put_layout_hdr(lo);
 433         }
 434 }
 435 EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 436
 437 static void pnfs_free_lseg_async_work(struct work_struct *work)
 438 {
 439         struct pnfs_layout_segment *lseg;
 440         struct pnfs_layout_hdr *lo;
 441
 442         lseg = container_of(work, struct pnfs_layout_segment, pls_work);
 443         lo = lseg->pls_layout;
 444
 445         pnfs_free_lseg(lseg);
 446         pnfs_put_layout_hdr(lo);
 447 }
 448
 449 static void pnfs_free_lseg_async(struct pnfs_layout_segment *lseg)
 450 {
 451         INIT_WORK(&lseg->pls_work, pnfs_free_lseg_async_work);
 452         schedule_work(&lseg->pls_work);
 453 }
 454
 455 void
 456 pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg)
 457 {
 458         if (!lseg)
 459                 return;
 460
 461         assert_spin_locked(&lseg->pls_layout->plh_inode->i_lock);
 462
 463         dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 464                 atomic_read(&lseg->pls_refcount),
 465                 test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 466         if (atomic_dec_and_test(&lseg->pls_refcount)) {
 467                 struct pnfs_layout_hdr *lo = lseg->pls_layout;
 468                 if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 469                         return;
 470                 pnfs_get_layout_hdr(lo);
 471                 pnfs_layout_remove_lseg(lo, lseg);
 472                 pnfs_free_lseg_async(lseg);
 473         }
 474 }
 475 EXPORT_SYMBOL_GPL(pnfs_put_lseg_locked);
 476
 477 static u64
 478 end_offset(u64 start, u64 len)
 479 {
 480         u64 end;
 481
 482         end = start + len;
 483         return end >= start ? end : NFS4_MAX_UINT64;
 484 }
 485
 486 /*
 487  * is l2 fully contained in l1?
 488  *   start1                             end1
 489  *   [----------------------------------)
 490  *           start2           end2
 491  *           [----------------)
 492  */
 493 static bool
 494 pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
 495                  const struct pnfs_layout_range *l2)
 496 {
 497         u64 start1 = l1->offset;
 498         u64 end1 = end_offset(start1, l1->length);
 499         u64 start2 = l2->offset;
 500         u64 end2 = end_offset(start2, l2->length);
 501
 502         return (start1 <= start2) && (end1 >= end2);
 503 }
 504
 505 /*
 506  * is l1 and l2 intersecting?
 507  *   start1                             end1
 508  *   [----------------------------------)
 509  *                              start2           end2
 510  *                              [----------------)
 511  */
 512 static bool
 513 pnfs_lseg_range_intersecting(const struct pnfs_layout_range *l1,
 514                     const struct pnfs_layout_range *l2)
 515 {
 516         u64 start1 = l1->offset;
 517         u64 end1 = end_offset(start1, l1->length);
 518         u64 start2 = l2->offset;
 519         u64 end2 = end_offset(start2, l2->length);
 520
 521         return (end1 == NFS4_MAX_UINT64 || end1 > start2) &&
 522                (end2 == NFS4_MAX_UINT64 || end2 > start1);
 523 }
 524
 525 static bool
 526 should_free_lseg(const struct pnfs_layout_range *lseg_range,
 527                  const struct pnfs_layout_range *recall_range)
 528 {
 529         return (recall_range->iomode == IOMODE_ANY ||
 530                 lseg_range->iomode == recall_range->iomode) &&
 531                pnfs_lseg_range_intersecting(lseg_range, recall_range);
 532 }
 533
 534 static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
 535                 struct list_head *tmp_list)
 536 {
 537         if (!atomic_dec_and_test(&lseg->pls_refcount))
 538                 return false;
 539         pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
 540         list_add(&lseg->pls_list, tmp_list);
 541         return true;
 542 }
 543
 544 /* Returns 1 if lseg is removed from list, 0 otherwise */
 545 static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
 546                              struct list_head *tmp_list)
 547 {
 548         int rv = 0;
 549
 550         if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 551                 /* Remove the reference keeping the lseg in the
 552                  * list.  It will now be removed when all
 553                  * outstanding io is finished.
 554                  */
 555                 dprintk("%s: lseg %p ref %d\n", __func__, lseg,
 556                         atomic_read(&lseg->pls_refcount));
 557                 if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
 558                         rv = 1;
 559         }
 560         return rv;
 561 }
 562
 563 /* Returns count of number of matching invalid lsegs remaining in list
 564  * after call.
 565  */
 566 int
 567 pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 568                             struct list_head *tmp_list,
 569                             struct pnfs_layout_range *recall_range)
 570 {
 571         struct pnfs_layout_segment *lseg, *next;
 572         int invalid = 0, removed = 0;
 573
 574         dprintk("%s:Begin lo %p\n", __func__, lo);
 575
 576         if (list_empty(&lo->plh_segs))
 577                 return 0;
 578         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 579                 if (!recall_range ||
 580                     should_free_lseg(&lseg->pls_range, recall_range)) {
 581                         dprintk("%s: freeing lseg %p iomode %d "
 582                                 "offset %llu length %llu\n", __func__,
 583                                 lseg, lseg->pls_range.iomode, lseg->pls_range.offset,
 584                                 lseg->pls_range.length);
 585                         invalid++;
 586                         removed += mark_lseg_invalid(lseg, tmp_list);
 587                 }
 588         dprintk("%s:Return %i\n", __func__, invalid - removed);
 589         return invalid - removed;
 590 }
 591
 592 /* note free_me must contain lsegs from a single layout_hdr */
 593 void
 594 pnfs_free_lseg_list(struct list_head *free_me)
 595 {
 596         struct pnfs_layout_segment *lseg, *tmp;
 597
 598         if (list_empty(free_me))
 599                 return;
 600
 601         list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
 602                 list_del(&lseg->pls_list);
 603                 pnfs_free_lseg(lseg);
 604         }
 605 }
 606
 607 void
 608 pnfs_destroy_layout(struct nfs_inode *nfsi)
 609 {
 610         struct pnfs_layout_hdr *lo;
 611         LIST_HEAD(tmp_list);
 612
 613         spin_lock(&nfsi->vfs_inode.i_lock);
 614         lo = nfsi->layout;
 615         if (lo) {
 616                 lo->plh_block_lgets++; /* permanently block new LAYOUTGETs */
 617                 pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
 618                 pnfs_get_layout_hdr(lo);
 619                 pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
 620                 pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
 621                 pnfs_clear_retry_layoutget(lo);
 622                 spin_unlock(&nfsi->vfs_inode.i_lock);
 623                 pnfs_free_lseg_list(&tmp_list);
 624                 pnfs_put_layout_hdr(lo);
 625         } else
 626                 spin_unlock(&nfsi->vfs_inode.i_lock);
 627 }
 628 EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
 629
 630 static bool
 631 pnfs_layout_add_bulk_destroy_list(struct inode *inode,
 632                 struct list_head *layout_list)
 633 {
 634         struct pnfs_layout_hdr *lo;
 635         bool ret = false;
 636
 637         spin_lock(&inode->i_lock);
 638         lo = NFS_I(inode)->layout;
 639         if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
 640                 pnfs_get_layout_hdr(lo);
 641                 list_add(&lo->plh_bulk_destroy, layout_list);
 642                 ret = true;
 643         }
 644         spin_unlock(&inode->i_lock);
 645         return ret;
 646 }
 647
 648 /* Caller must hold rcu_read_lock and clp->cl_lock */
 649 static int
 650 pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
 651                 struct nfs_server *server,
 652                 struct list_head *layout_list)
 653 {
 654         struct pnfs_layout_hdr *lo, *next;
 655         struct inode *inode;
 656
 657         list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
 658                 inode = igrab(lo->plh_inode);
 659                 if (inode == NULL)
 660                         continue;
 661                 list_del_init(&lo->plh_layouts);
 662                 if (pnfs_layout_add_bulk_destroy_list(inode, layout_list))
 663                         continue;
 664                 rcu_read_unlock();
 665                 spin_unlock(&clp->cl_lock);
 666                 iput(inode);
 667                 spin_lock(&clp->cl_lock);
 668                 rcu_read_lock();
 669                 return -EAGAIN;
 670         }
 671         return 0;
 672 }
 673
 674 static int
 675 pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
 676                 bool is_bulk_recall)
 677 {
 678         struct pnfs_layout_hdr *lo;
 679         struct inode *inode;
 680         struct pnfs_layout_range range = {
 681                 .iomode = IOMODE_ANY,
 682                 .offset = 0,
 683                 .length = NFS4_MAX_UINT64,
 684         };
 685         LIST_HEAD(lseg_list);
 686         int ret = 0;
 687
 688         while (!list_empty(layout_list)) {
 689                 lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
 690                                 plh_bulk_destroy);
 691                 dprintk("%s freeing layout for inode %lu\n", __func__,
 692                         lo->plh_inode->i_ino);
 693                 inode = lo->plh_inode;
 694
 695                 pnfs_layoutcommit_inode(inode, false);
 696
 697                 spin_lock(&inode->i_lock);
 698                 list_del_init(&lo->plh_bulk_destroy);
 699                 lo->plh_block_lgets++; /* permanently block new LAYOUTGETs */
 700                 if (is_bulk_recall)
 701                         set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 702                 if (pnfs_mark_matching_lsegs_invalid(lo, &lseg_list, &range))
 703                         ret = -EAGAIN;
 704                 spin_unlock(&inode->i_lock);
 705                 pnfs_free_lseg_list(&lseg_list);
 706                 pnfs_put_layout_hdr(lo);
 707                 iput(inode);
 708         }
 709         return ret;
 710 }
 711
 712 int
 713 pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
 714                 struct nfs_fsid *fsid,
 715                 bool is_recall)
 716 {
 717         struct nfs_server *server;
 718         LIST_HEAD(layout_list);
 719
 720         spin_lock(&clp->cl_lock);
 721         rcu_read_lock();
 722 restart:
 723         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 724                 if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
 725                         continue;
 726                 if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 727                                 server,
 728                                 &layout_list) != 0)
 729                         goto restart;
 730         }
 731         rcu_read_unlock();
 732         spin_unlock(&clp->cl_lock);
 733
 734         if (list_empty(&layout_list))
 735                 return 0;
 736         return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 737 }
 738
 739 int
 740 pnfs_destroy_layouts_byclid(struct nfs_client *clp,
 741                 bool is_recall)
 742 {
 743         struct nfs_server *server;
 744         LIST_HEAD(layout_list);
 745
 746         spin_lock(&clp->cl_lock);
 747         rcu_read_lock();
 748 restart:
 749         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 750                 if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 751                                         server,
 752                                         &layout_list) != 0)
 753                         goto restart;
 754         }
 755         rcu_read_unlock();
 756         spin_unlock(&clp->cl_lock);
 757
 758         if (list_empty(&layout_list))
 759                 return 0;
 760         return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 761 }
 762
 763 /*
 764  * Called by the state manger to remove all layouts established under an
 765  * expired lease.
 766  */
 767 void
 768 pnfs_destroy_all_layouts(struct nfs_client *clp)
 769 {
 770         nfs4_deviceid_mark_client_invalid(clp);
 771         nfs4_deviceid_purge_client(clp);
 772
 773         pnfs_destroy_layouts_byclid(clp, false);
 774 }
 775
 776 /*
 777  * Compare 2 layout stateid sequence ids, to see which is newer,
 778  * taking into account wraparound issues.
 779  */
 780 static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
 781 {
 782         return (s32)(s1 - s2) > 0;
 783 }
 784
 785 /* update lo->plh_stateid with new if is more recent */
 786 void
 787 pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
 788                         bool update_barrier)
 789 {
 790         u32 oldseq, newseq, new_barrier;
 791         int empty = list_empty(&lo->plh_segs);
 792
 793         oldseq = be32_to_cpu(lo->plh_stateid.seqid);
 794         newseq = be32_to_cpu(new->seqid);
 795         if (empty || pnfs_seqid_is_newer(newseq, oldseq)) {
 796                 nfs4_stateid_copy(&lo->plh_stateid, new);
 797                 if (update_barrier) {
 798                         new_barrier = be32_to_cpu(new->seqid);
 799                 } else {
 800                         /* Because of wraparound, we want to keep the barrier
 801                          * "close" to the current seqids.
 802                          */
 803                         new_barrier = newseq - atomic_read(&lo->plh_outstanding);
 804                 }
 805                 if (empty || pnfs_seqid_is_newer(new_barrier, lo->plh_barrier))
 806                         lo->plh_barrier = new_barrier;
 807         }
 808 }
 809
 810 static bool
 811 pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
 812                 const nfs4_stateid *stateid)
 813 {
 814         u32 seqid = be32_to_cpu(stateid->seqid);
 815
 816         return !pnfs_seqid_is_newer(seqid, lo->plh_barrier);
 817 }
 818
 819 /* lget is set to 1 if called from inside send_layoutget call chain */
 820 static bool
 821 pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
 822 {
 823         return lo->plh_block_lgets ||
 824                 test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 825 }
 826
 827 int
 828 pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
 829                               struct pnfs_layout_range *range,
 830                               struct nfs4_state *open_state)
 831 {
 832         int status = 0;
 833
 834         dprintk("--> %s\n", __func__);
 835         spin_lock(&lo->plh_inode->i_lock);
 836         if (pnfs_layoutgets_blocked(lo)) {
 837                 status = -EAGAIN;
 838         } else if (!nfs4_valid_open_stateid(open_state)) {
 839                 status = -EBADF;
 840         } else if (list_empty(&lo->plh_segs) ||
 841                    test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
 842                 int seq;
 843
 844                 do {
 845                         seq = read_seqbegin(&open_state->seqlock);
 846                         nfs4_stateid_copy(dst, &open_state->stateid);
 847                 } while (read_seqretry(&open_state->seqlock, seq));
 848         } else
 849                 nfs4_stateid_copy(dst, &lo->plh_stateid);
 850         spin_unlock(&lo->plh_inode->i_lock);
 851         dprintk("<-- %s\n", __func__);
 852         return status;
 853 }
 854
 855 /*
 856 * Get layout from server.
 857 *    for now, assume that whole file layouts are requested.
 858 *    arg->offset: 0
 859 *    arg->length: all ones
 860 */
 861 static struct pnfs_layout_segment *
 862 send_layoutget(struct pnfs_layout_hdr *lo,
 863            struct nfs_open_context *ctx,
 864            struct pnfs_layout_range *range,
 865            gfp_t gfp_flags)
 866 {
 867         struct inode *ino = lo->plh_inode;
 868         struct nfs_server *server = NFS_SERVER(ino);
 869         struct nfs4_layoutget *lgp;
 870         struct pnfs_layout_segment *lseg;
 871         loff_t i_size;
 872
 873         dprintk("--> %s\n", __func__);
 874
 875         lgp = kzalloc(sizeof(*lgp), gfp_flags);
 876         if (lgp == NULL)
 877                 return NULL;
 878
 879         i_size = i_size_read(ino);
 880
 881         lgp->args.minlength = PAGE_CACHE_SIZE;
 882         if (lgp->args.minlength > range->length)
 883                 lgp->args.minlength = range->length;
 884         if (range->iomode == IOMODE_READ) {
 885                 if (range->offset >= i_size)
 886                         lgp->args.minlength = 0;
 887                 else if (i_size - range->offset < lgp->args.minlength)
 888                         lgp->args.minlength = i_size - range->offset;
 889         }
 890         lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
 891         lgp->args.range = *range;
 892         lgp->args.type = server->pnfs_curr_ld->id;
 893         lgp->args.inode = ino;
 894         lgp->args.ctx = get_nfs_open_context(ctx);
 895         lgp->gfp_flags = gfp_flags;
 896         lgp->cred = lo->plh_lc_cred;
 897
 898         /* Synchronously retrieve layout information from server and
 899          * store in lseg.
 900          */
 901         lseg = nfs4_proc_layoutget(lgp, gfp_flags);
 902         if (IS_ERR(lseg)) {
 903                 switch (PTR_ERR(lseg)) {
 904                 case -ENOMEM:
 905                 case -ERESTARTSYS:
 906                         break;
 907                 default:
 908                         /* remember that LAYOUTGET failed and suspend trying */
 909                         pnfs_layout_io_set_failed(lo, range->iomode);
 910                 }
 911                 return NULL;
 912         } else
 913                 pnfs_layout_clear_fail_bit(lo,
 914                                 pnfs_iomode_to_fail_bit(range->iomode));
 915
 916         return lseg;
 917 }
 918
 919 static void pnfs_clear_layoutcommit(struct inode *inode,
 920                 struct list_head *head)
 921 {
 922         struct nfs_inode *nfsi = NFS_I(inode);
 923         struct pnfs_layout_segment *lseg, *tmp;
 924
 925         if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
 926                 return;
 927         list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
 928                 if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 929                         continue;
 930                 pnfs_lseg_dec_and_remove_zero(lseg, head);
 931         }
 932 }
 933
 934 void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
 935 {
 936         clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
 937         smp_mb__after_atomic();
 938         wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
 939         rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
 940 }
 941
 942 static int
 943 pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo, nfs4_stateid stateid,
 944                        enum pnfs_iomode iomode, bool sync)
 945 {
 946         struct inode *ino = lo->plh_inode;
 947         struct nfs4_layoutreturn *lrp;
 948         int status = 0;
 949
 950         lrp = kzalloc(sizeof(*lrp), GFP_NOFS);
 951         if (unlikely(lrp == NULL)) {
 952                 status = -ENOMEM;
 953                 spin_lock(&ino->i_lock);
 954                 pnfs_clear_layoutreturn_waitbit(lo);
 955                 spin_unlock(&ino->i_lock);
 956                 pnfs_put_layout_hdr(lo);
 957                 goto out;
 958         }
 959
 960         lrp->args.stateid = stateid;
 961         lrp->args.layout_type = NFS_SERVER(ino)->pnfs_curr_ld->id;
 962         lrp->args.inode = ino;
 963         lrp->args.range.iomode = iomode;
 964         lrp->args.range.offset = 0;
 965         lrp->args.range.length = NFS4_MAX_UINT64;
 966         lrp->args.layout = lo;
 967         lrp->clp = NFS_SERVER(ino)->nfs_client;
 968         lrp->cred = lo->plh_lc_cred;
 969
 970         status = nfs4_proc_layoutreturn(lrp, sync);
 971 out:
 972         dprintk("<-- %s status: %d\n", __func__, status);
 973         return status;
 974 }
 975
 976 /*
 977  * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
 978  * when the layout segment list is empty.
 979  *
 980  * Note that a pnfs_layout_hdr can exist with an empty layout segment
 981  * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
 982  * deviceid is marked invalid.
 983  */
 984 int
 985 _pnfs_return_layout(struct inode *ino)
 986 {
 987         struct pnfs_layout_hdr *lo = NULL;
 988         struct nfs_inode *nfsi = NFS_I(ino);
 989         LIST_HEAD(tmp_list);
 990         nfs4_stateid stateid;
 991         int status = 0, empty;
 992         bool send;
 993
 994         dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
 995
 996         spin_lock(&ino->i_lock);
 997         lo = nfsi->layout;
 998         if (!lo) {
 999                 spin_unlock(&ino->i_lock);
1000                 dprintk("NFS: %s no layout to return\n", __func__);
1001                 goto out;
1002         }
1003         stateid = nfsi->layout->plh_stateid;
1004         /* Reference matched in nfs4_layoutreturn_release */
1005         pnfs_get_layout_hdr(lo);
1006         empty = list_empty(&lo->plh_segs);
1007         pnfs_clear_layoutcommit(ino, &tmp_list);
1008         pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
1009
1010         if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) {
1011                 struct pnfs_layout_range range = {
1012                         .iomode         = IOMODE_ANY,
1013                         .offset         = 0,
1014                         .length         = NFS4_MAX_UINT64,
1015                 };
1016                 NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
1017         }
1018
1019         /* Don't send a LAYOUTRETURN if list was initially empty */
1020         if (empty) {
1021                 spin_unlock(&ino->i_lock);
1022                 dprintk("NFS: %s no layout segments to return\n", __func__);
1023                 goto out_put_layout_hdr;
1024         }
1025
1026         set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
1027         send = pnfs_prepare_layoutreturn(lo);
1028         spin_unlock(&ino->i_lock);
1029         pnfs_free_lseg_list(&tmp_list);
1030         if (send)
1031                 status = pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, true);
1032 out_put_layout_hdr:
1033         pnfs_put_layout_hdr(lo);
1034 out:
1035         dprintk("<-- %s status: %d\n", __func__, status);
1036         return status;
1037 }
1038 EXPORT_SYMBOL_GPL(_pnfs_return_layout);
1039
1040 int
1041 pnfs_commit_and_return_layout(struct inode *inode)
1042 {
1043         struct pnfs_layout_hdr *lo;
1044         int ret;
1045
1046         spin_lock(&inode->i_lock);
1047         lo = NFS_I(inode)->layout;
1048         if (lo == NULL) {
1049                 spin_unlock(&inode->i_lock);
1050                 return 0;
1051         }
1052         pnfs_get_layout_hdr(lo);
1053         /* Block new layoutgets and read/write to ds */
1054         lo->plh_block_lgets++;
1055         spin_unlock(&inode->i_lock);
1056         filemap_fdatawait(inode->i_mapping);
1057         ret = pnfs_layoutcommit_inode(inode, true);
1058         if (ret == 0)
1059                 ret = _pnfs_return_layout(inode);
1060         spin_lock(&inode->i_lock);
1061         lo->plh_block_lgets--;
1062         spin_unlock(&inode->i_lock);
1063         pnfs_put_layout_hdr(lo);
1064         return ret;
1065 }
1066
1067 bool pnfs_roc(struct inode *ino)
1068 {
1069         struct nfs_inode *nfsi = NFS_I(ino);
1070         struct nfs_open_context *ctx;
1071         struct nfs4_state *state;
1072         struct pnfs_layout_hdr *lo;
1073         struct pnfs_layout_segment *lseg, *tmp;
1074         nfs4_stateid stateid;
1075         LIST_HEAD(tmp_list);
1076         bool found = false, layoutreturn = false, roc = false;
1077
1078         spin_lock(&ino->i_lock);
1079         lo = nfsi->layout;
1080         if (!lo || test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
1081                 goto out_noroc;
1082
1083         /* no roc if we hold a delegation */
1084         if (nfs4_check_delegation(ino, FMODE_READ))
1085                 goto out_noroc;
1086
1087         list_for_each_entry(ctx, &nfsi->open_files, list) {
1088                 state = ctx->state;
1089                 /* Don't return layout if there is open file state */
1090                 if (state != NULL && state->state != 0)
1091                         goto out_noroc;
1092         }
1093
1094         stateid = lo->plh_stateid;
1095         /* always send layoutreturn if being marked so */
1096         if (test_and_clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
1097                                    &lo->plh_flags))
1098                 layoutreturn = pnfs_prepare_layoutreturn(lo);
1099
1100         pnfs_clear_retry_layoutget(lo);
1101         list_for_each_entry_safe(lseg, tmp, &lo->plh_segs, pls_list)
1102                 /* If we are sending layoutreturn, invalidate all valid lsegs */
1103                 if (layoutreturn || test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) {
1104                         mark_lseg_invalid(lseg, &tmp_list);
1105                         found = true;
1106                 }
1107         /* pnfs_prepare_layoutreturn() grabs lo ref and it will be put
1108          * in pnfs_roc_release(). We don't really send a layoutreturn but
1109          * still want others to view us like we are sending one!
1110          *
1111          * If pnfs_prepare_layoutreturn() fails, it means someone else is doing
1112          * LAYOUTRETURN, so we proceed like there are no layouts to return.
1113          *
1114          * ROC in three conditions:
1115          * 1. there are ROC lsegs
1116          * 2. we don't send layoutreturn
1117          * 3. no others are sending layoutreturn
1118          */
1119         if (found && !layoutreturn && pnfs_prepare_layoutreturn(lo))
1120                 roc = true;
1121
1122 out_noroc:
1123         spin_unlock(&ino->i_lock);
1124         pnfs_free_lseg_list(&tmp_list);
1125         pnfs_layoutcommit_inode(ino, true);
1126         if (layoutreturn)
1127                 pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, true);
1128         return roc;
1129 }
1130
1131 void pnfs_roc_release(struct inode *ino)
1132 {
1133         struct pnfs_layout_hdr *lo;
1134
1135         spin_lock(&ino->i_lock);
1136         lo = NFS_I(ino)->layout;
1137         pnfs_clear_layoutreturn_waitbit(lo);
1138         if (atomic_dec_and_test(&lo->plh_refcount)) {
1139                 pnfs_detach_layout_hdr(lo);
1140                 spin_unlock(&ino->i_lock);
1141                 pnfs_free_layout_hdr(lo);
1142         } else
1143                 spin_unlock(&ino->i_lock);
1144 }
1145
1146 void pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
1147 {
1148         struct pnfs_layout_hdr *lo;
1149
1150         spin_lock(&ino->i_lock);
1151         lo = NFS_I(ino)->layout;
1152         if (pnfs_seqid_is_newer(barrier, lo->plh_barrier))
1153                 lo->plh_barrier = barrier;
1154         spin_unlock(&ino->i_lock);
1155         trace_nfs4_layoutreturn_on_close(ino, 0);
1156 }
1157
1158 void pnfs_roc_get_barrier(struct inode *ino, u32 *barrier)
1159 {
1160         struct nfs_inode *nfsi = NFS_I(ino);
1161         struct pnfs_layout_hdr *lo;
1162         u32 current_seqid;
1163
1164         spin_lock(&ino->i_lock);
1165         lo = nfsi->layout;
1166         current_seqid = be32_to_cpu(lo->plh_stateid.seqid);
1167
1168         /* Since close does not return a layout stateid for use as
1169          * a barrier, we choose the worst-case barrier.
1170          */
1171         *barrier = current_seqid + atomic_read(&lo->plh_outstanding);
1172         spin_unlock(&ino->i_lock);
1173 }
1174
1175 /*
1176  * Compare two layout segments for sorting into layout cache.
1177  * We want to preferentially return RW over RO layouts, so ensure those
1178  * are seen first.
1179  */
1180 static s64
1181 pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1182            const struct pnfs_layout_range *l2)
1183 {
1184         s64 d;
1185
1186         /* high offset > low offset */
1187         d = l1->offset - l2->offset;
1188         if (d)
1189                 return d;
1190
1191         /* short length > long length */
1192         d = l2->length - l1->length;
1193         if (d)
1194                 return d;
1195
1196         /* read > read/write */
1197         return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1198 }
1199
1200 static bool
1201 pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1202                 const struct pnfs_layout_range *l2)
1203 {
1204         return pnfs_lseg_range_cmp(l1, l2) > 0;
1205 }
1206
1207 static bool
1208 pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1209                 struct pnfs_layout_segment *old)
1210 {
1211         return false;
1212 }
1213
1214 void
1215 pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1216                    struct pnfs_layout_segment *lseg,
1217                    bool (*is_after)(const struct pnfs_layout_range *,
1218                            const struct pnfs_layout_range *),
1219                    bool (*do_merge)(struct pnfs_layout_segment *,
1220                            struct pnfs_layout_segment *),
1221                    struct list_head *free_me)
1222 {
1223         struct pnfs_layout_segment *lp, *tmp;
1224
1225         dprintk("%s:Begin\n", __func__);
1226
1227         list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1228                 if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1229                         continue;
1230                 if (do_merge(lseg, lp)) {
1231                         mark_lseg_invalid(lp, free_me);
1232                         continue;
1233                 }
1234                 if (is_after(&lseg->pls_range, &lp->pls_range))
1235                         continue;
1236                 list_add_tail(&lseg->pls_list, &lp->pls_list);
1237                 dprintk("%s: inserted lseg %p "
1238                         "iomode %d offset %llu length %llu before "
1239                         "lp %p iomode %d offset %llu length %llu\n",
1240                         __func__, lseg, lseg->pls_range.iomode,
1241                         lseg->pls_range.offset, lseg->pls_range.length,
1242                         lp, lp->pls_range.iomode, lp->pls_range.offset,
1243                         lp->pls_range.length);
1244                 goto out;
1245         }
1246         list_add_tail(&lseg->pls_list, &lo->plh_segs);
1247         dprintk("%s: inserted lseg %p "
1248                 "iomode %d offset %llu length %llu at tail\n",
1249                 __func__, lseg, lseg->pls_range.iomode,
1250                 lseg->pls_range.offset, lseg->pls_range.length);
1251 out:
1252         pnfs_get_layout_hdr(lo);
1253
1254         dprintk("%s:Return\n", __func__);
1255 }
1256 EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1257
1258 static void
1259 pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1260                    struct pnfs_layout_segment *lseg,
1261                    struct list_head *free_me)
1262 {
1263         struct inode *inode = lo->plh_inode;
1264         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1265
1266         if (ld->add_lseg != NULL)
1267                 ld->add_lseg(lo, lseg, free_me);
1268         else
1269                 pnfs_generic_layout_insert_lseg(lo, lseg,
1270                                 pnfs_lseg_range_is_after,
1271                                 pnfs_lseg_no_merge,
1272                                 free_me);
1273 }
1274
1275 static struct pnfs_layout_hdr *
1276 alloc_init_layout_hdr(struct inode *ino,
1277                       struct nfs_open_context *ctx,
1278                       gfp_t gfp_flags)
1279 {
1280         struct pnfs_layout_hdr *lo;
1281
1282         lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1283         if (!lo)
1284                 return NULL;
1285         atomic_set(&lo->plh_refcount, 1);
1286         INIT_LIST_HEAD(&lo->plh_layouts);
1287         INIT_LIST_HEAD(&lo->plh_segs);
1288         INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1289         lo->plh_inode = ino;
1290         lo->plh_lc_cred = get_rpccred(ctx->cred);
1291         return lo;
1292 }
1293
1294 static struct pnfs_layout_hdr *
1295 pnfs_find_alloc_layout(struct inode *ino,
1296                        struct nfs_open_context *ctx,
1297                        gfp_t gfp_flags)
1298 {
1299         struct nfs_inode *nfsi = NFS_I(ino);
1300         struct pnfs_layout_hdr *new = NULL;
1301
1302         dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1303
1304         if (nfsi->layout != NULL)
1305                 goto out_existing;
1306         spin_unlock(&ino->i_lock);
1307         new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1308         spin_lock(&ino->i_lock);
1309
1310         if (likely(nfsi->layout == NULL)) {     /* Won the race? */
1311                 nfsi->layout = new;
1312                 return new;
1313         } else if (new != NULL)
1314                 pnfs_free_layout_hdr(new);
1315 out_existing:
1316         pnfs_get_layout_hdr(nfsi->layout);
1317         return nfsi->layout;
1318 }
1319
1320 /*
1321  * iomode matching rules:
1322  * iomode       lseg    match
1323  * -----        -----   -----
1324  * ANY          READ    true
1325  * ANY          RW      true
1326  * RW           READ    false
1327  * RW           RW      true
1328  * READ         READ    true
1329  * READ         RW      true
1330  */
1331 static bool
1332 pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1333                  const struct pnfs_layout_range *range)
1334 {
1335         struct pnfs_layout_range range1;
1336
1337         if ((range->iomode == IOMODE_RW &&
1338              ls_range->iomode != IOMODE_RW) ||
1339             !pnfs_lseg_range_intersecting(ls_range, range))
1340                 return 0;
1341
1342         /* range1 covers only the first byte in the range */
1343         range1 = *range;
1344         range1.length = 1;
1345         return pnfs_lseg_range_contained(ls_range, &range1);
1346 }
1347
1348 /*
1349  * lookup range in layout
1350  */
1351 static struct pnfs_layout_segment *
1352 pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1353                 struct pnfs_layout_range *range)
1354 {
1355         struct pnfs_layout_segment *lseg, *ret = NULL;
1356
1357         dprintk("%s:Begin\n", __func__);
1358
1359         list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1360                 if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1361                     !test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
1362                     pnfs_lseg_range_match(&lseg->pls_range, range)) {
1363                         ret = pnfs_get_lseg(lseg);
1364                         break;
1365                 }
1366         }
1367
1368         dprintk("%s:Return lseg %p ref %d\n",
1369                 __func__, ret, ret ? atomic_read(&ret->pls_refcount) : 0);
1370         return ret;
1371 }
1372
1373 /*
1374  * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1375  * to the MDS or over pNFS
1376  *
1377  * The nfs_inode read_io and write_io fields are cumulative counters reset
1378  * when there are no layout segments. Note that in pnfs_update_layout iomode
1379  * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1380  * WRITE request.
1381  *
1382  * A return of true means use MDS I/O.
1383  *
1384  * From rfc 5661:
1385  * If a file's size is smaller than the file size threshold, data accesses
1386  * SHOULD be sent to the metadata server.  If an I/O request has a length that
1387  * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1388  * server.  If both file size and I/O size are provided, the client SHOULD
1389  * reach or exceed  both thresholds before sending its read or write
1390  * requests to the data server.
1391  */
1392 static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1393                                      struct inode *ino, int iomode)
1394 {
1395         struct nfs4_threshold *t = ctx->mdsthreshold;
1396         struct nfs_inode *nfsi = NFS_I(ino);
1397         loff_t fsize = i_size_read(ino);
1398         bool size = false, size_set = false, io = false, io_set = false, ret = false;
1399
1400         if (t == NULL)
1401                 return ret;
1402
1403         dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1404                 __func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1405
1406         switch (iomode) {
1407         case IOMODE_READ:
1408                 if (t->bm & THRESHOLD_RD) {
1409                         dprintk("%s fsize %llu\n", __func__, fsize);
1410                         size_set = true;
1411                         if (fsize < t->rd_sz)
1412                                 size = true;
1413                 }
1414                 if (t->bm & THRESHOLD_RD_IO) {
1415                         dprintk("%s nfsi->read_io %llu\n", __func__,
1416                                 nfsi->read_io);
1417                         io_set = true;
1418                         if (nfsi->read_io < t->rd_io_sz)
1419                                 io = true;
1420                 }
1421                 break;
1422         case IOMODE_RW:
1423                 if (t->bm & THRESHOLD_WR) {
1424                         dprintk("%s fsize %llu\n", __func__, fsize);
1425                         size_set = true;
1426                         if (fsize < t->wr_sz)
1427                                 size = true;
1428                 }
1429                 if (t->bm & THRESHOLD_WR_IO) {
1430                         dprintk("%s nfsi->write_io %llu\n", __func__,
1431                                 nfsi->write_io);
1432                         io_set = true;
1433                         if (nfsi->write_io < t->wr_io_sz)
1434                                 io = true;
1435                 }
1436                 break;
1437         }
1438         if (size_set && io_set) {
1439                 if (size && io)
1440                         ret = true;
1441         } else if (size || io)
1442                 ret = true;
1443
1444         dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1445         return ret;
1446 }
1447
1448 /* stop waiting if someone clears NFS_LAYOUT_RETRY_LAYOUTGET bit. */
1449 static int pnfs_layoutget_retry_bit_wait(struct wait_bit_key *key)
1450 {
1451         if (!test_bit(NFS_LAYOUT_RETRY_LAYOUTGET, key->flags))
1452                 return 1;
1453         return nfs_wait_bit_killable(key);
1454 }
1455
1456 static bool pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
1457 {
1458         if (!pnfs_should_retry_layoutget(lo))
1459                 return false;
1460         /*
1461          * send layoutcommit as it can hold up layoutreturn due to lseg
1462          * reference
1463          */
1464         pnfs_layoutcommit_inode(lo->plh_inode, false);
1465         return !wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
1466                                    pnfs_layoutget_retry_bit_wait,
1467                                    TASK_UNINTERRUPTIBLE);
1468 }
1469
1470 static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
1471 {
1472         unsigned long *bitlock = &lo->plh_flags;
1473
1474         clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
1475         smp_mb__after_atomic();
1476         wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
1477 }
1478
1479 /*
1480  * Layout segment is retreived from the server if not cached.
1481  * The appropriate layout segment is referenced and returned to the caller.
1482  */
1483 struct pnfs_layout_segment *
1484 pnfs_update_layout(struct inode *ino,
1485                    struct nfs_open_context *ctx,
1486                    loff_t pos,
1487                    u64 count,
1488                    enum pnfs_iomode iomode,
1489                    gfp_t gfp_flags)
1490 {
1491         struct pnfs_layout_range arg = {
1492                 .iomode = iomode,
1493                 .offset = pos,
1494                 .length = count,
1495         };
1496         unsigned pg_offset;
1497         struct nfs_server *server = NFS_SERVER(ino);
1498         struct nfs_client *clp = server->nfs_client;
1499         struct pnfs_layout_hdr *lo;
1500         struct pnfs_layout_segment *lseg = NULL;
1501         bool first;
1502
1503         if (!pnfs_enabled_sb(NFS_SERVER(ino)))
1504                 goto out;
1505
1506         if (iomode == IOMODE_READ && i_size_read(ino) == 0)
1507                 goto out;
1508
1509         if (pnfs_within_mdsthreshold(ctx, ino, iomode))
1510                 goto out;
1511
1512 lookup_again:
1513         first = false;
1514         spin_lock(&ino->i_lock);
1515         lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
1516         if (lo == NULL) {
1517                 spin_unlock(&ino->i_lock);
1518                 goto out;
1519         }
1520
1521         /* Do we even need to bother with this? */
1522         if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1523                 dprintk("%s matches recall, use MDS\n", __func__);
1524                 goto out_unlock;
1525         }
1526
1527         /* if LAYOUTGET already failed once we don't try again */
1528         if (pnfs_layout_io_test_failed(lo, iomode) &&
1529             !pnfs_should_retry_layoutget(lo))
1530                 goto out_unlock;
1531
1532         first = list_empty(&lo->plh_segs);
1533         if (first) {
1534                 /* The first layoutget for the file. Need to serialize per
1535                  * RFC 5661 Errata 3208.
1536                  */
1537                 if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
1538                                      &lo->plh_flags)) {
1539                         spin_unlock(&ino->i_lock);
1540                         wait_on_bit(&lo->plh_flags, NFS_LAYOUT_FIRST_LAYOUTGET,
1541                                     TASK_UNINTERRUPTIBLE);
1542                         pnfs_put_layout_hdr(lo);
1543                         goto lookup_again;
1544                 }
1545         } else {
1546                 /* Check to see if the layout for the given range
1547                  * already exists
1548                  */
1549                 lseg = pnfs_find_lseg(lo, &arg);
1550                 if (lseg)
1551                         goto out_unlock;
1552         }
1553
1554         /*
1555          * Because we free lsegs before sending LAYOUTRETURN, we need to wait
1556          * for LAYOUTRETURN even if first is true.
1557          */
1558         if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1559                 spin_unlock(&ino->i_lock);
1560                 dprintk("%s wait for layoutreturn\n", __func__);
1561                 if (pnfs_prepare_to_retry_layoutget(lo)) {
1562                         if (first)
1563                                 pnfs_clear_first_layoutget(lo);
1564                         pnfs_put_layout_hdr(lo);
1565                         dprintk("%s retrying\n", __func__);
1566                         goto lookup_again;
1567                 }
1568                 goto out_put_layout_hdr;
1569         }
1570
1571         if (pnfs_layoutgets_blocked(lo))
1572                 goto out_unlock;
1573         atomic_inc(&lo->plh_outstanding);
1574         spin_unlock(&ino->i_lock);
1575
1576         if (list_empty(&lo->plh_layouts)) {
1577                 /* The lo must be on the clp list if there is any
1578                  * chance of a CB_LAYOUTRECALL(FILE) coming in.
1579                  */
1580                 spin_lock(&clp->cl_lock);
1581                 if (list_empty(&lo->plh_layouts))
1582                         list_add_tail(&lo->plh_layouts, &server->layouts);
1583                 spin_unlock(&clp->cl_lock);
1584         }
1585
1586         pg_offset = arg.offset & ~PAGE_CACHE_MASK;
1587         if (pg_offset) {
1588                 arg.offset -= pg_offset;
1589                 arg.length += pg_offset;
1590         }
1591         if (arg.length != NFS4_MAX_UINT64)
1592                 arg.length = PAGE_CACHE_ALIGN(arg.length);
1593
1594         lseg = send_layoutget(lo, ctx, &arg, gfp_flags);
1595         pnfs_clear_retry_layoutget(lo);
1596         atomic_dec(&lo->plh_outstanding);
1597 out_put_layout_hdr:
1598         if (first)
1599                 pnfs_clear_first_layoutget(lo);
1600         pnfs_put_layout_hdr(lo);
1601 out:
1602         dprintk("%s: inode %s/%llu pNFS layout segment %s for "
1603                         "(%s, offset: %llu, length: %llu)\n",
1604                         __func__, ino->i_sb->s_id,
1605                         (unsigned long long)NFS_FILEID(ino),
1606                         lseg == NULL ? "not found" : "found",
1607                         iomode==IOMODE_RW ?  "read/write" : "read-only",
1608                         (unsigned long long)pos,
1609                         (unsigned long long)count);
1610         return lseg;
1611 out_unlock:
1612         spin_unlock(&ino->i_lock);
1613         goto out_put_layout_hdr;
1614 }
1615 EXPORT_SYMBOL_GPL(pnfs_update_layout);
1616
1617 static bool
1618 pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
1619 {
1620         switch (range->iomode) {
1621         case IOMODE_READ:
1622         case IOMODE_RW:
1623                 break;
1624         default:
1625                 return false;
1626         }
1627         if (range->offset == NFS4_MAX_UINT64)
1628                 return false;
1629         if (range->length == 0)
1630                 return false;
1631         if (range->length != NFS4_MAX_UINT64 &&
1632             range->length > NFS4_MAX_UINT64 - range->offset)
1633                 return false;
1634         return true;
1635 }
1636
1637 struct pnfs_layout_segment *
1638 pnfs_layout_process(struct nfs4_layoutget *lgp)
1639 {
1640         struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
1641         struct nfs4_layoutget_res *res = &lgp->res;
1642         struct pnfs_layout_segment *lseg;
1643         struct inode *ino = lo->plh_inode;
1644         LIST_HEAD(free_me);
1645         int status = -EINVAL;
1646
1647         if (!pnfs_sanity_check_layout_range(&res->range))
1648                 goto out;
1649
1650         /* Inject layout blob into I/O device driver */
1651         lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
1652         if (!lseg || IS_ERR(lseg)) {
1653                 if (!lseg)
1654                         status = -ENOMEM;
1655                 else
1656                         status = PTR_ERR(lseg);
1657                 dprintk("%s: Could not allocate layout: error %d\n",
1658                        __func__, status);
1659                 goto out;
1660         }
1661
1662         init_lseg(lo, lseg);
1663         lseg->pls_range = res->range;
1664
1665         spin_lock(&ino->i_lock);
1666         if (pnfs_layoutgets_blocked(lo)) {
1667                 dprintk("%s forget reply due to state\n", __func__);
1668                 goto out_forget_reply;
1669         }
1670
1671         if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
1672                 /* existing state ID, make sure the sequence number matches. */
1673                 if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
1674                         dprintk("%s forget reply due to sequence\n", __func__);
1675                         goto out_forget_reply;
1676                 }
1677                 pnfs_set_layout_stateid(lo, &res->stateid, false);
1678         } else {
1679                 /*
1680                  * We got an entirely new state ID.  Mark all segments for the
1681                  * inode invalid, and don't bother validating the stateid
1682                  * sequence number.
1683                  */
1684                 pnfs_mark_matching_lsegs_invalid(lo, &free_me, NULL);
1685
1686                 nfs4_stateid_copy(&lo->plh_stateid, &res->stateid);
1687                 lo->plh_barrier = be32_to_cpu(res->stateid.seqid);
1688         }
1689
1690         clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
1691
1692         pnfs_get_lseg(lseg);
1693         pnfs_layout_insert_lseg(lo, lseg, &free_me);
1694
1695         if (res->return_on_close)
1696                 set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
1697
1698         spin_unlock(&ino->i_lock);
1699         pnfs_free_lseg_list(&free_me);
1700         return lseg;
1701 out:
1702         return ERR_PTR(status);
1703
1704 out_forget_reply:
1705         spin_unlock(&ino->i_lock);
1706         lseg->pls_layout = lo;
1707         NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
1708         goto out;
1709 }
1710
1711 static void
1712 pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
1713                                 struct list_head *tmp_list,
1714                                 struct pnfs_layout_range *return_range)
1715 {
1716         struct pnfs_layout_segment *lseg, *next;
1717
1718         dprintk("%s:Begin lo %p\n", __func__, lo);
1719
1720         if (list_empty(&lo->plh_segs))
1721                 return;
1722
1723         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
1724                 if (should_free_lseg(&lseg->pls_range, return_range)) {
1725                         dprintk("%s: marking lseg %p iomode %d "
1726                                 "offset %llu length %llu\n", __func__,
1727                                 lseg, lseg->pls_range.iomode,
1728                                 lseg->pls_range.offset,
1729                                 lseg->pls_range.length);
1730                         set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1731                         mark_lseg_invalid(lseg, tmp_list);
1732                         set_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
1733                                         &lo->plh_flags);
1734                 }
1735 }
1736
1737 void pnfs_error_mark_layout_for_return(struct inode *inode,
1738                                        struct pnfs_layout_segment *lseg)
1739 {
1740         struct pnfs_layout_hdr *lo = NFS_I(inode)->layout;
1741         int iomode = pnfs_iomode_to_fail_bit(lseg->pls_range.iomode);
1742         struct pnfs_layout_range range = {
1743                 .iomode = lseg->pls_range.iomode,
1744                 .offset = 0,
1745                 .length = NFS4_MAX_UINT64,
1746         };
1747         LIST_HEAD(free_me);
1748
1749         spin_lock(&inode->i_lock);
1750         /* set failure bit so that pnfs path will be retried later */
1751         pnfs_layout_set_fail_bit(lo, iomode);
1752         if (lo->plh_return_iomode == 0)
1753                 lo->plh_return_iomode = range.iomode;
1754         else if (lo->plh_return_iomode != range.iomode)
1755                 lo->plh_return_iomode = IOMODE_ANY;
1756         /*
1757          * mark all matching lsegs so that we are sure to have no live
1758          * segments at hand when sending layoutreturn. See pnfs_put_lseg()
1759          * for how it works.
1760          */
1761         pnfs_mark_matching_lsegs_return(lo, &free_me, &range);
1762         spin_unlock(&inode->i_lock);
1763         pnfs_free_lseg_list(&free_me);
1764 }
1765 EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
1766
1767 void
1768 pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
1769 {
1770         u64 rd_size = req->wb_bytes;
1771
1772         if (pgio->pg_lseg == NULL) {
1773                 if (pgio->pg_dreq == NULL)
1774                         rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
1775                 else
1776                         rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
1777
1778                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
1779                                                    req->wb_context,
1780                                                    req_offset(req),
1781                                                    rd_size,
1782                                                    IOMODE_READ,
1783                                                    GFP_KERNEL);
1784         }
1785         /* If no lseg, fall back to read through mds */
1786         if (pgio->pg_lseg == NULL)
1787                 nfs_pageio_reset_read_mds(pgio);
1788
1789 }
1790 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
1791
1792 void
1793 pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
1794                            struct nfs_page *req, u64 wb_size)
1795 {
1796         if (pgio->pg_lseg == NULL)
1797                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
1798                                                    req->wb_context,
1799                                                    req_offset(req),
1800                                                    wb_size,
1801                                                    IOMODE_RW,
1802                                                    GFP_NOFS);
1803         /* If no lseg, fall back to write through mds */
1804         if (pgio->pg_lseg == NULL)
1805                 nfs_pageio_reset_write_mds(pgio);
1806 }
1807 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
1808
1809 void
1810 pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
1811 {
1812         if (desc->pg_lseg) {
1813                 pnfs_put_lseg(desc->pg_lseg);
1814                 desc->pg_lseg = NULL;
1815         }
1816 }
1817 EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
1818
1819 /*
1820  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
1821  * of bytes (maximum @req->wb_bytes) that can be coalesced.
1822  */
1823 size_t
1824 pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
1825                      struct nfs_page *prev, struct nfs_page *req)
1826 {
1827         unsigned int size;
1828         u64 seg_end, req_start, seg_left;
1829
1830         size = nfs_generic_pg_test(pgio, prev, req);
1831         if (!size)
1832                 return 0;
1833
1834         /*
1835          * 'size' contains the number of bytes left in the current page (up
1836          * to the original size asked for in @req->wb_bytes).
1837          *
1838          * Calculate how many bytes are left in the layout segment
1839          * and if there are less bytes than 'size', return that instead.
1840          *
1841          * Please also note that 'end_offset' is actually the offset of the
1842          * first byte that lies outside the pnfs_layout_range. FIXME?
1843          *
1844          */
1845         if (pgio->pg_lseg) {
1846                 seg_end = end_offset(pgio->pg_lseg->pls_range.offset,
1847                                      pgio->pg_lseg->pls_range.length);
1848                 req_start = req_offset(req);
1849                 WARN_ON_ONCE(req_start >= seg_end);
1850                 /* start of request is past the last byte of this segment */
1851                 if (req_start >= seg_end) {
1852                         /* reference the new lseg */
1853                         if (pgio->pg_ops->pg_cleanup)
1854                                 pgio->pg_ops->pg_cleanup(pgio);
1855                         if (pgio->pg_ops->pg_init)
1856                                 pgio->pg_ops->pg_init(pgio, req);
1857                         return 0;
1858                 }
1859
1860                 /* adjust 'size' iff there are fewer bytes left in the
1861                  * segment than what nfs_generic_pg_test returned */
1862                 seg_left = seg_end - req_start;
1863                 if (seg_left < size)
1864                         size = (unsigned int)seg_left;
1865         }
1866
1867         return size;
1868 }
1869 EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
1870
1871 int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
1872 {
1873         struct nfs_pageio_descriptor pgio;
1874
1875         /* Resend all requests through the MDS */
1876         nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
1877                               hdr->completion_ops);
1878         set_bit(NFS_CONTEXT_RESEND_WRITES, &hdr->args.context->flags);
1879         return nfs_pageio_resend(&pgio, hdr);
1880 }
1881 EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
1882
1883 static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
1884 {
1885
1886         dprintk("pnfs write error = %d\n", hdr->pnfs_error);
1887         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
1888             PNFS_LAYOUTRET_ON_ERROR) {
1889                 pnfs_return_layout(hdr->inode);
1890         }
1891         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
1892                 hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
1893 }
1894
1895 /*
1896  * Called by non rpc-based layout drivers
1897  */
1898 void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
1899 {
1900         trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
1901         if (!hdr->pnfs_error) {
1902                 pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
1903                                 hdr->mds_offset + hdr->res.count);
1904                 hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
1905         } else
1906                 pnfs_ld_handle_write_error(hdr);
1907         hdr->mds_ops->rpc_release(hdr);
1908 }
1909 EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
1910
1911 static void
1912 pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
1913                 struct nfs_pgio_header *hdr)
1914 {
1915         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1916
1917         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1918                 list_splice_tail_init(&hdr->pages, &mirror->pg_list);
1919                 nfs_pageio_reset_write_mds(desc);
1920                 mirror->pg_recoalesce = 1;
1921         }
1922         nfs_pgio_data_destroy(hdr);
1923         hdr->release(hdr);
1924 }
1925
1926 static enum pnfs_try_status
1927 pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
1928                         const struct rpc_call_ops *call_ops,
1929                         struct pnfs_layout_segment *lseg,
1930                         int how)
1931 {
1932         struct inode *inode = hdr->inode;
1933         enum pnfs_try_status trypnfs;
1934         struct nfs_server *nfss = NFS_SERVER(inode);
1935
1936         hdr->mds_ops = call_ops;
1937
1938         dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
1939                 inode->i_ino, hdr->args.count, hdr->args.offset, how);
1940         trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
1941         if (trypnfs != PNFS_NOT_ATTEMPTED)
1942                 nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
1943         dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
1944         return trypnfs;
1945 }
1946
1947 static void
1948 pnfs_do_write(struct nfs_pageio_descriptor *desc,
1949               struct nfs_pgio_header *hdr, int how)
1950 {
1951         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
1952         struct pnfs_layout_segment *lseg = desc->pg_lseg;
1953         enum pnfs_try_status trypnfs;
1954
1955         trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
1956         if (trypnfs == PNFS_NOT_ATTEMPTED)
1957                 pnfs_write_through_mds(desc, hdr);
1958 }
1959
1960 static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
1961 {
1962         pnfs_put_lseg(hdr->lseg);
1963         nfs_pgio_header_free(hdr);
1964 }
1965
1966 int
1967 pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
1968 {
1969         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1970
1971         struct nfs_pgio_header *hdr;
1972         int ret;
1973
1974         hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
1975         if (!hdr) {
1976                 desc->pg_completion_ops->error_cleanup(&mirror->pg_list);
1977                 return -ENOMEM;
1978         }
1979         nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
1980
1981         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
1982         ret = nfs_generic_pgio(desc, hdr);
1983         if (!ret)
1984                 pnfs_do_write(desc, hdr, desc->pg_ioflags);
1985
1986         return ret;
1987 }
1988 EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
1989
1990 int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
1991 {
1992         struct nfs_pageio_descriptor pgio;
1993
1994         /* Resend all requests through the MDS */
1995         nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
1996         return nfs_pageio_resend(&pgio, hdr);
1997 }
1998 EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
1999
2000 static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
2001 {
2002         dprintk("pnfs read error = %d\n", hdr->pnfs_error);
2003         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2004             PNFS_LAYOUTRET_ON_ERROR) {
2005                 pnfs_return_layout(hdr->inode);
2006         }
2007         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2008                 hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
2009 }
2010
2011 /*
2012  * Called by non rpc-based layout drivers
2013  */
2014 void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
2015 {
2016         trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
2017         if (likely(!hdr->pnfs_error)) {
2018                 __nfs4_read_done_cb(hdr);
2019                 hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2020         } else
2021                 pnfs_ld_handle_read_error(hdr);
2022         hdr->mds_ops->rpc_release(hdr);
2023 }
2024 EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
2025
2026 static void
2027 pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
2028                 struct nfs_pgio_header *hdr)
2029 {
2030         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2031
2032         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2033                 list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2034                 nfs_pageio_reset_read_mds(desc);
2035                 mirror->pg_recoalesce = 1;
2036         }
2037         nfs_pgio_data_destroy(hdr);
2038         hdr->release(hdr);
2039 }
2040
2041 /*
2042  * Call the appropriate parallel I/O subsystem read function.
2043  */
2044 static enum pnfs_try_status
2045 pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
2046                        const struct rpc_call_ops *call_ops,
2047                        struct pnfs_layout_segment *lseg)
2048 {
2049         struct inode *inode = hdr->inode;
2050         struct nfs_server *nfss = NFS_SERVER(inode);
2051         enum pnfs_try_status trypnfs;
2052
2053         hdr->mds_ops = call_ops;
2054
2055         dprintk("%s: Reading ino:%lu %u@%llu\n",
2056                 __func__, inode->i_ino, hdr->args.count, hdr->args.offset);
2057
2058         trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
2059         if (trypnfs != PNFS_NOT_ATTEMPTED)
2060                 nfs_inc_stats(inode, NFSIOS_PNFS_READ);
2061         dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2062         return trypnfs;
2063 }
2064
2065 /* Resend all requests through pnfs. */
2066 int pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr)
2067 {
2068         struct nfs_pageio_descriptor pgio;
2069
2070         nfs_pageio_init_read(&pgio, hdr->inode, false, hdr->completion_ops);
2071         return nfs_pageio_resend(&pgio, hdr);
2072 }
2073 EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
2074
2075 static void
2076 pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
2077 {
2078         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2079         struct pnfs_layout_segment *lseg = desc->pg_lseg;
2080         enum pnfs_try_status trypnfs;
2081         int err = 0;
2082
2083         trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
2084         if (trypnfs == PNFS_TRY_AGAIN)
2085                 err = pnfs_read_resend_pnfs(hdr);
2086         if (trypnfs == PNFS_NOT_ATTEMPTED || err)
2087                 pnfs_read_through_mds(desc, hdr);
2088 }
2089
2090 static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
2091 {
2092         pnfs_put_lseg(hdr->lseg);
2093         nfs_pgio_header_free(hdr);
2094 }
2095
2096 int
2097 pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
2098 {
2099         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2100
2101         struct nfs_pgio_header *hdr;
2102         int ret;
2103
2104         hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2105         if (!hdr) {
2106                 desc->pg_completion_ops->error_cleanup(&mirror->pg_list);
2107                 return -ENOMEM;
2108         }
2109         nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
2110         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2111         ret = nfs_generic_pgio(desc, hdr);
2112         if (!ret)
2113                 pnfs_do_read(desc, hdr);
2114         return ret;
2115 }
2116 EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
2117
2118 static void pnfs_clear_layoutcommitting(struct inode *inode)
2119 {
2120         unsigned long *bitlock = &NFS_I(inode)->flags;
2121
2122         clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
2123         smp_mb__after_atomic();
2124         wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
2125 }
2126
2127 /*
2128  * There can be multiple RW segments.
2129  */
2130 static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
2131 {
2132         struct pnfs_layout_segment *lseg;
2133
2134         list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
2135                 if (lseg->pls_range.iomode == IOMODE_RW &&
2136                     test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
2137                         list_add(&lseg->pls_lc_list, listp);
2138         }
2139 }
2140
2141 static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
2142 {
2143         struct pnfs_layout_segment *lseg, *tmp;
2144
2145         /* Matched by references in pnfs_set_layoutcommit */
2146         list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
2147                 list_del_init(&lseg->pls_lc_list);
2148                 pnfs_put_lseg(lseg);
2149         }
2150
2151         pnfs_clear_layoutcommitting(inode);
2152 }
2153
2154 void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
2155 {
2156         pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
2157 }
2158 EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
2159
2160 void
2161 pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
2162                 loff_t end_pos)
2163 {
2164         struct nfs_inode *nfsi = NFS_I(inode);
2165         bool mark_as_dirty = false;
2166
2167         spin_lock(&inode->i_lock);
2168         if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
2169                 nfsi->layout->plh_lwb = end_pos;
2170                 mark_as_dirty = true;
2171                 dprintk("%s: Set layoutcommit for inode %lu ",
2172                         __func__, inode->i_ino);
2173         } else if (end_pos > nfsi->layout->plh_lwb)
2174                 nfsi->layout->plh_lwb = end_pos;
2175         if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
2176                 /* references matched in nfs4_layoutcommit_release */
2177                 pnfs_get_lseg(lseg);
2178         }
2179         spin_unlock(&inode->i_lock);
2180         dprintk("%s: lseg %p end_pos %llu\n",
2181                 __func__, lseg, nfsi->layout->plh_lwb);
2182
2183         /* if pnfs_layoutcommit_inode() runs between inode locks, the next one
2184          * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
2185         if (mark_as_dirty)
2186                 mark_inode_dirty_sync(inode);
2187 }
2188 EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
2189
2190 void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
2191 {
2192         struct nfs_server *nfss = NFS_SERVER(data->args.inode);
2193
2194         if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
2195                 nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
2196         pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
2197 }
2198
2199 /*
2200  * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
2201  * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
2202  * data to disk to allow the server to recover the data if it crashes.
2203  * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
2204  * is off, and a COMMIT is sent to a data server, or
2205  * if WRITEs to a data server return NFS_DATA_SYNC.
2206  */
2207 int
2208 pnfs_layoutcommit_inode(struct inode *inode, bool sync)
2209 {
2210         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2211         struct nfs4_layoutcommit_data *data;
2212         struct nfs_inode *nfsi = NFS_I(inode);
2213         loff_t end_pos;
2214         int status;
2215
2216         if (!pnfs_layoutcommit_outstanding(inode))
2217                 return 0;
2218
2219         dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
2220
2221         status = -EAGAIN;
2222         if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
2223                 if (!sync)
2224                         goto out;
2225                 status = wait_on_bit_lock_action(&nfsi->flags,
2226                                 NFS_INO_LAYOUTCOMMITTING,
2227                                 nfs_wait_bit_killable,
2228                                 TASK_KILLABLE);
2229                 if (status)
2230                         goto out;
2231         }
2232
2233         status = -ENOMEM;
2234         /* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
2235         data = kzalloc(sizeof(*data), GFP_NOFS);
2236         if (!data)
2237                 goto clear_layoutcommitting;
2238
2239         status = 0;
2240         spin_lock(&inode->i_lock);
2241         if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
2242                 goto out_unlock;
2243
2244         INIT_LIST_HEAD(&data->lseg_list);
2245         pnfs_list_write_lseg(inode, &data->lseg_list);
2246
2247         end_pos = nfsi->layout->plh_lwb;
2248
2249         nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
2250         spin_unlock(&inode->i_lock);
2251
2252         data->args.inode = inode;
2253         data->cred = get_rpccred(nfsi->layout->plh_lc_cred);
2254         nfs_fattr_init(&data->fattr);
2255         data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
2256         data->res.fattr = &data->fattr;
2257         data->args.lastbytewritten = end_pos - 1;
2258         data->res.server = NFS_SERVER(inode);
2259
2260         if (ld->prepare_layoutcommit) {
2261                 status = ld->prepare_layoutcommit(&data->args);
2262                 if (status) {
2263                         put_rpccred(data->cred);
2264                         spin_lock(&inode->i_lock);
2265                         set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
2266                         if (end_pos > nfsi->layout->plh_lwb)
2267                                 nfsi->layout->plh_lwb = end_pos;
2268                         goto out_unlock;
2269                 }
2270         }
2271
2272
2273         status = nfs4_proc_layoutcommit(data, sync);
2274 out:
2275         if (status)
2276                 mark_inode_dirty_sync(inode);
2277         dprintk("<-- %s status %d\n", __func__, status);
2278         return status;
2279 out_unlock:
2280         spin_unlock(&inode->i_lock);
2281         kfree(data);
2282 clear_layoutcommitting:
2283         pnfs_clear_layoutcommitting(inode);
2284         goto out;
2285 }
2286 EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
2287
2288 int
2289 pnfs_generic_sync(struct inode *inode, bool datasync)
2290 {
2291         return pnfs_layoutcommit_inode(inode, true);
2292 }
2293 EXPORT_SYMBOL_GPL(pnfs_generic_sync);
2294
2295 struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
2296 {
2297         struct nfs4_threshold *thp;
2298
2299         thp = kzalloc(sizeof(*thp), GFP_NOFS);
2300         if (!thp) {
2301                 dprintk("%s mdsthreshold allocation failed\n", __func__);
2302                 return NULL;
2303         }
2304         return thp;
2305 }
2306
2307 #if IS_ENABLED(CONFIG_NFS_V4_2)
2308 int
2309 pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
2310 {
2311         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2312         struct nfs_server *server = NFS_SERVER(inode);
2313         struct nfs_inode *nfsi = NFS_I(inode);
2314         struct nfs42_layoutstat_data *data;
2315         struct pnfs_layout_hdr *hdr;
2316         int status = 0;
2317
2318         if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
2319                 goto out;
2320
2321         if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
2322                 goto out;
2323
2324         if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
2325                 goto out;
2326
2327         spin_lock(&inode->i_lock);
2328         if (!NFS_I(inode)->layout) {
2329                 spin_unlock(&inode->i_lock);
2330                 goto out;
2331         }
2332         hdr = NFS_I(inode)->layout;
2333         pnfs_get_layout_hdr(hdr);
2334         spin_unlock(&inode->i_lock);
2335
2336         data = kzalloc(sizeof(*data), gfp_flags);
2337         if (!data) {
2338                 status = -ENOMEM;
2339                 goto out_put;
2340         }
2341
2342         data->args.fh = NFS_FH(inode);
2343         data->args.inode = inode;
2344         nfs4_stateid_copy(&data->args.stateid, &hdr->plh_stateid);
2345         status = ld->prepare_layoutstats(&data->args);
2346         if (status)
2347                 goto out_free;
2348
2349         status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
2350
2351 out:
2352         dprintk("%s returns %d\n", __func__, status);
2353         return status;
2354
2355 out_free:
2356         kfree(data);
2357 out_put:
2358         pnfs_put_layout_hdr(hdr);
2359         smp_mb__before_atomic();
2360         clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
2361         smp_mb__after_atomic();
2362         goto out;
2363 }
2364 EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
2365 #endif
2366
2367 unsigned int layoutstats_timer;
2368 module_param(layoutstats_timer, uint, 0644);
2369 EXPORT_SYMBOL_GPL(layoutstats_timer);