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         /* ROC in two conditions:
1108          * 1. there are ROC lsegs
1109          * 2. we don't send layoutreturn
1110          */
1111         if (found && !layoutreturn) {
1112                 /* lo ref dropped in pnfs_roc_release() */
1113                 pnfs_get_layout_hdr(lo);
1114                 roc = true;
1115         }
1116
1117 out_noroc:
1118         spin_unlock(&ino->i_lock);
1119         pnfs_free_lseg_list(&tmp_list);
1120         pnfs_layoutcommit_inode(ino, true);
1121         if (layoutreturn)
1122                 pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, true);
1123         return roc;
1124 }
1125
1126 void pnfs_roc_release(struct inode *ino)
1127 {
1128         struct pnfs_layout_hdr *lo;
1129
1130         spin_lock(&ino->i_lock);
1131         lo = NFS_I(ino)->layout;
1132         pnfs_clear_layoutreturn_waitbit(lo);
1133         if (atomic_dec_and_test(&lo->plh_refcount)) {
1134                 pnfs_detach_layout_hdr(lo);
1135                 spin_unlock(&ino->i_lock);
1136                 pnfs_free_layout_hdr(lo);
1137         } else
1138                 spin_unlock(&ino->i_lock);
1139 }
1140
1141 void pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
1142 {
1143         struct pnfs_layout_hdr *lo;
1144
1145         spin_lock(&ino->i_lock);
1146         lo = NFS_I(ino)->layout;
1147         if (pnfs_seqid_is_newer(barrier, lo->plh_barrier))
1148                 lo->plh_barrier = barrier;
1149         spin_unlock(&ino->i_lock);
1150         trace_nfs4_layoutreturn_on_close(ino, 0);
1151 }
1152
1153 void pnfs_roc_get_barrier(struct inode *ino, u32 *barrier)
1154 {
1155         struct nfs_inode *nfsi = NFS_I(ino);
1156         struct pnfs_layout_hdr *lo;
1157         u32 current_seqid;
1158
1159         spin_lock(&ino->i_lock);
1160         lo = nfsi->layout;
1161         current_seqid = be32_to_cpu(lo->plh_stateid.seqid);
1162
1163         /* Since close does not return a layout stateid for use as
1164          * a barrier, we choose the worst-case barrier.
1165          */
1166         *barrier = current_seqid + atomic_read(&lo->plh_outstanding);
1167         spin_unlock(&ino->i_lock);
1168 }
1169
1170 bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
1171 {
1172         struct nfs_inode *nfsi = NFS_I(ino);
1173         struct pnfs_layout_hdr *lo;
1174         bool sleep = false;
1175
1176         /* we might not have grabbed lo reference. so need to check under
1177          * i_lock */
1178         spin_lock(&ino->i_lock);
1179         lo = nfsi->layout;
1180         if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
1181                 sleep = true;
1182         spin_unlock(&ino->i_lock);
1183
1184         if (sleep)
1185                 rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
1186
1187         return sleep;
1188 }
1189
1190 /*
1191  * Compare two layout segments for sorting into layout cache.
1192  * We want to preferentially return RW over RO layouts, so ensure those
1193  * are seen first.
1194  */
1195 static s64
1196 pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1197            const struct pnfs_layout_range *l2)
1198 {
1199         s64 d;
1200
1201         /* high offset > low offset */
1202         d = l1->offset - l2->offset;
1203         if (d)
1204                 return d;
1205
1206         /* short length > long length */
1207         d = l2->length - l1->length;
1208         if (d)
1209                 return d;
1210
1211         /* read > read/write */
1212         return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1213 }
1214
1215 static bool
1216 pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1217                 const struct pnfs_layout_range *l2)
1218 {
1219         return pnfs_lseg_range_cmp(l1, l2) > 0;
1220 }
1221
1222 static bool
1223 pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1224                 struct pnfs_layout_segment *old)
1225 {
1226         return false;
1227 }
1228
1229 void
1230 pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1231                    struct pnfs_layout_segment *lseg,
1232                    bool (*is_after)(const struct pnfs_layout_range *,
1233                            const struct pnfs_layout_range *),
1234                    bool (*do_merge)(struct pnfs_layout_segment *,
1235                            struct pnfs_layout_segment *),
1236                    struct list_head *free_me)
1237 {
1238         struct pnfs_layout_segment *lp, *tmp;
1239
1240         dprintk("%s:Begin\n", __func__);
1241
1242         list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1243                 if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1244                         continue;
1245                 if (do_merge(lseg, lp)) {
1246                         mark_lseg_invalid(lp, free_me);
1247                         continue;
1248                 }
1249                 if (is_after(&lseg->pls_range, &lp->pls_range))
1250                         continue;
1251                 list_add_tail(&lseg->pls_list, &lp->pls_list);
1252                 dprintk("%s: inserted lseg %p "
1253                         "iomode %d offset %llu length %llu before "
1254                         "lp %p iomode %d offset %llu length %llu\n",
1255                         __func__, lseg, lseg->pls_range.iomode,
1256                         lseg->pls_range.offset, lseg->pls_range.length,
1257                         lp, lp->pls_range.iomode, lp->pls_range.offset,
1258                         lp->pls_range.length);
1259                 goto out;
1260         }
1261         list_add_tail(&lseg->pls_list, &lo->plh_segs);
1262         dprintk("%s: inserted lseg %p "
1263                 "iomode %d offset %llu length %llu at tail\n",
1264                 __func__, lseg, lseg->pls_range.iomode,
1265                 lseg->pls_range.offset, lseg->pls_range.length);
1266 out:
1267         pnfs_get_layout_hdr(lo);
1268
1269         dprintk("%s:Return\n", __func__);
1270 }
1271 EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1272
1273 static void
1274 pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1275                    struct pnfs_layout_segment *lseg,
1276                    struct list_head *free_me)
1277 {
1278         struct inode *inode = lo->plh_inode;
1279         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1280
1281         if (ld->add_lseg != NULL)
1282                 ld->add_lseg(lo, lseg, free_me);
1283         else
1284                 pnfs_generic_layout_insert_lseg(lo, lseg,
1285                                 pnfs_lseg_range_is_after,
1286                                 pnfs_lseg_no_merge,
1287                                 free_me);
1288 }
1289
1290 static struct pnfs_layout_hdr *
1291 alloc_init_layout_hdr(struct inode *ino,
1292                       struct nfs_open_context *ctx,
1293                       gfp_t gfp_flags)
1294 {
1295         struct pnfs_layout_hdr *lo;
1296
1297         lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1298         if (!lo)
1299                 return NULL;
1300         atomic_set(&lo->plh_refcount, 1);
1301         INIT_LIST_HEAD(&lo->plh_layouts);
1302         INIT_LIST_HEAD(&lo->plh_segs);
1303         INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1304         lo->plh_inode = ino;
1305         lo->plh_lc_cred = get_rpccred(ctx->cred);
1306         return lo;
1307 }
1308
1309 static struct pnfs_layout_hdr *
1310 pnfs_find_alloc_layout(struct inode *ino,
1311                        struct nfs_open_context *ctx,
1312                        gfp_t gfp_flags)
1313 {
1314         struct nfs_inode *nfsi = NFS_I(ino);
1315         struct pnfs_layout_hdr *new = NULL;
1316
1317         dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1318
1319         if (nfsi->layout != NULL)
1320                 goto out_existing;
1321         spin_unlock(&ino->i_lock);
1322         new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1323         spin_lock(&ino->i_lock);
1324
1325         if (likely(nfsi->layout == NULL)) {     /* Won the race? */
1326                 nfsi->layout = new;
1327                 return new;
1328         } else if (new != NULL)
1329                 pnfs_free_layout_hdr(new);
1330 out_existing:
1331         pnfs_get_layout_hdr(nfsi->layout);
1332         return nfsi->layout;
1333 }
1334
1335 /*
1336  * iomode matching rules:
1337  * iomode       lseg    match
1338  * -----        -----   -----
1339  * ANY          READ    true
1340  * ANY          RW      true
1341  * RW           READ    false
1342  * RW           RW      true
1343  * READ         READ    true
1344  * READ         RW      true
1345  */
1346 static bool
1347 pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1348                  const struct pnfs_layout_range *range)
1349 {
1350         struct pnfs_layout_range range1;
1351
1352         if ((range->iomode == IOMODE_RW &&
1353              ls_range->iomode != IOMODE_RW) ||
1354             !pnfs_lseg_range_intersecting(ls_range, range))
1355                 return 0;
1356
1357         /* range1 covers only the first byte in the range */
1358         range1 = *range;
1359         range1.length = 1;
1360         return pnfs_lseg_range_contained(ls_range, &range1);
1361 }
1362
1363 /*
1364  * lookup range in layout
1365  */
1366 static struct pnfs_layout_segment *
1367 pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1368                 struct pnfs_layout_range *range)
1369 {
1370         struct pnfs_layout_segment *lseg, *ret = NULL;
1371
1372         dprintk("%s:Begin\n", __func__);
1373
1374         list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1375                 if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1376                     !test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
1377                     pnfs_lseg_range_match(&lseg->pls_range, range)) {
1378                         ret = pnfs_get_lseg(lseg);
1379                         break;
1380                 }
1381         }
1382
1383         dprintk("%s:Return lseg %p ref %d\n",
1384                 __func__, ret, ret ? atomic_read(&ret->pls_refcount) : 0);
1385         return ret;
1386 }
1387
1388 /*
1389  * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1390  * to the MDS or over pNFS
1391  *
1392  * The nfs_inode read_io and write_io fields are cumulative counters reset
1393  * when there are no layout segments. Note that in pnfs_update_layout iomode
1394  * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1395  * WRITE request.
1396  *
1397  * A return of true means use MDS I/O.
1398  *
1399  * From rfc 5661:
1400  * If a file's size is smaller than the file size threshold, data accesses
1401  * SHOULD be sent to the metadata server.  If an I/O request has a length that
1402  * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1403  * server.  If both file size and I/O size are provided, the client SHOULD
1404  * reach or exceed  both thresholds before sending its read or write
1405  * requests to the data server.
1406  */
1407 static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1408                                      struct inode *ino, int iomode)
1409 {
1410         struct nfs4_threshold *t = ctx->mdsthreshold;
1411         struct nfs_inode *nfsi = NFS_I(ino);
1412         loff_t fsize = i_size_read(ino);
1413         bool size = false, size_set = false, io = false, io_set = false, ret = false;
1414
1415         if (t == NULL)
1416                 return ret;
1417
1418         dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1419                 __func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1420
1421         switch (iomode) {
1422         case IOMODE_READ:
1423                 if (t->bm & THRESHOLD_RD) {
1424                         dprintk("%s fsize %llu\n", __func__, fsize);
1425                         size_set = true;
1426                         if (fsize < t->rd_sz)
1427                                 size = true;
1428                 }
1429                 if (t->bm & THRESHOLD_RD_IO) {
1430                         dprintk("%s nfsi->read_io %llu\n", __func__,
1431                                 nfsi->read_io);
1432                         io_set = true;
1433                         if (nfsi->read_io < t->rd_io_sz)
1434                                 io = true;
1435                 }
1436                 break;
1437         case IOMODE_RW:
1438                 if (t->bm & THRESHOLD_WR) {
1439                         dprintk("%s fsize %llu\n", __func__, fsize);
1440                         size_set = true;
1441                         if (fsize < t->wr_sz)
1442                                 size = true;
1443                 }
1444                 if (t->bm & THRESHOLD_WR_IO) {
1445                         dprintk("%s nfsi->write_io %llu\n", __func__,
1446                                 nfsi->write_io);
1447                         io_set = true;
1448                         if (nfsi->write_io < t->wr_io_sz)
1449                                 io = true;
1450                 }
1451                 break;
1452         }
1453         if (size_set && io_set) {
1454                 if (size && io)
1455                         ret = true;
1456         } else if (size || io)
1457                 ret = true;
1458
1459         dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1460         return ret;
1461 }
1462
1463 /* stop waiting if someone clears NFS_LAYOUT_RETRY_LAYOUTGET bit. */
1464 static int pnfs_layoutget_retry_bit_wait(struct wait_bit_key *key)
1465 {
1466         if (!test_bit(NFS_LAYOUT_RETRY_LAYOUTGET, key->flags))
1467                 return 1;
1468         return nfs_wait_bit_killable(key);
1469 }
1470
1471 static bool pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
1472 {
1473         if (!pnfs_should_retry_layoutget(lo))
1474                 return false;
1475         /*
1476          * send layoutcommit as it can hold up layoutreturn due to lseg
1477          * reference
1478          */
1479         pnfs_layoutcommit_inode(lo->plh_inode, false);
1480         return !wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
1481                                    pnfs_layoutget_retry_bit_wait,
1482                                    TASK_UNINTERRUPTIBLE);
1483 }
1484
1485 static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
1486 {
1487         unsigned long *bitlock = &lo->plh_flags;
1488
1489         clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
1490         smp_mb__after_atomic();
1491         wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
1492 }
1493
1494 /*
1495  * Layout segment is retreived from the server if not cached.
1496  * The appropriate layout segment is referenced and returned to the caller.
1497  */
1498 struct pnfs_layout_segment *
1499 pnfs_update_layout(struct inode *ino,
1500                    struct nfs_open_context *ctx,
1501                    loff_t pos,
1502                    u64 count,
1503                    enum pnfs_iomode iomode,
1504                    gfp_t gfp_flags)
1505 {
1506         struct pnfs_layout_range arg = {
1507                 .iomode = iomode,
1508                 .offset = pos,
1509                 .length = count,
1510         };
1511         unsigned pg_offset;
1512         struct nfs_server *server = NFS_SERVER(ino);
1513         struct nfs_client *clp = server->nfs_client;
1514         struct pnfs_layout_hdr *lo;
1515         struct pnfs_layout_segment *lseg = NULL;
1516         bool first;
1517
1518         if (!pnfs_enabled_sb(NFS_SERVER(ino)))
1519                 goto out;
1520
1521         if (iomode == IOMODE_READ && i_size_read(ino) == 0)
1522                 goto out;
1523
1524         if (pnfs_within_mdsthreshold(ctx, ino, iomode))
1525                 goto out;
1526
1527 lookup_again:
1528         first = false;
1529         spin_lock(&ino->i_lock);
1530         lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
1531         if (lo == NULL) {
1532                 spin_unlock(&ino->i_lock);
1533                 goto out;
1534         }
1535
1536         /* Do we even need to bother with this? */
1537         if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1538                 dprintk("%s matches recall, use MDS\n", __func__);
1539                 goto out_unlock;
1540         }
1541
1542         /* if LAYOUTGET already failed once we don't try again */
1543         if (pnfs_layout_io_test_failed(lo, iomode) &&
1544             !pnfs_should_retry_layoutget(lo))
1545                 goto out_unlock;
1546
1547         first = list_empty(&lo->plh_segs);
1548         if (first) {
1549                 /* The first layoutget for the file. Need to serialize per
1550                  * RFC 5661 Errata 3208.
1551                  */
1552                 if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
1553                                      &lo->plh_flags)) {
1554                         spin_unlock(&ino->i_lock);
1555                         wait_on_bit(&lo->plh_flags, NFS_LAYOUT_FIRST_LAYOUTGET,
1556                                     TASK_UNINTERRUPTIBLE);
1557                         pnfs_put_layout_hdr(lo);
1558                         goto lookup_again;
1559                 }
1560         } else {
1561                 /* Check to see if the layout for the given range
1562                  * already exists
1563                  */
1564                 lseg = pnfs_find_lseg(lo, &arg);
1565                 if (lseg)
1566                         goto out_unlock;
1567         }
1568
1569         /*
1570          * Because we free lsegs before sending LAYOUTRETURN, we need to wait
1571          * for LAYOUTRETURN even if first is true.
1572          */
1573         if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1574                 spin_unlock(&ino->i_lock);
1575                 dprintk("%s wait for layoutreturn\n", __func__);
1576                 if (pnfs_prepare_to_retry_layoutget(lo)) {
1577                         if (first)
1578                                 pnfs_clear_first_layoutget(lo);
1579                         pnfs_put_layout_hdr(lo);
1580                         dprintk("%s retrying\n", __func__);
1581                         goto lookup_again;
1582                 }
1583                 goto out_put_layout_hdr;
1584         }
1585
1586         if (pnfs_layoutgets_blocked(lo))
1587                 goto out_unlock;
1588         atomic_inc(&lo->plh_outstanding);
1589         spin_unlock(&ino->i_lock);
1590
1591         if (list_empty(&lo->plh_layouts)) {
1592                 /* The lo must be on the clp list if there is any
1593                  * chance of a CB_LAYOUTRECALL(FILE) coming in.
1594                  */
1595                 spin_lock(&clp->cl_lock);
1596                 if (list_empty(&lo->plh_layouts))
1597                         list_add_tail(&lo->plh_layouts, &server->layouts);
1598                 spin_unlock(&clp->cl_lock);
1599         }
1600
1601         pg_offset = arg.offset & ~PAGE_CACHE_MASK;
1602         if (pg_offset) {
1603                 arg.offset -= pg_offset;
1604                 arg.length += pg_offset;
1605         }
1606         if (arg.length != NFS4_MAX_UINT64)
1607                 arg.length = PAGE_CACHE_ALIGN(arg.length);
1608
1609         lseg = send_layoutget(lo, ctx, &arg, gfp_flags);
1610         pnfs_clear_retry_layoutget(lo);
1611         atomic_dec(&lo->plh_outstanding);
1612 out_put_layout_hdr:
1613         if (first)
1614                 pnfs_clear_first_layoutget(lo);
1615         pnfs_put_layout_hdr(lo);
1616 out:
1617         dprintk("%s: inode %s/%llu pNFS layout segment %s for "
1618                         "(%s, offset: %llu, length: %llu)\n",
1619                         __func__, ino->i_sb->s_id,
1620                         (unsigned long long)NFS_FILEID(ino),
1621                         lseg == NULL ? "not found" : "found",
1622                         iomode==IOMODE_RW ?  "read/write" : "read-only",
1623                         (unsigned long long)pos,
1624                         (unsigned long long)count);
1625         return lseg;
1626 out_unlock:
1627         spin_unlock(&ino->i_lock);
1628         goto out_put_layout_hdr;
1629 }
1630 EXPORT_SYMBOL_GPL(pnfs_update_layout);
1631
1632 static bool
1633 pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
1634 {
1635         switch (range->iomode) {
1636         case IOMODE_READ:
1637         case IOMODE_RW:
1638                 break;
1639         default:
1640                 return false;
1641         }
1642         if (range->offset == NFS4_MAX_UINT64)
1643                 return false;
1644         if (range->length == 0)
1645                 return false;
1646         if (range->length != NFS4_MAX_UINT64 &&
1647             range->length > NFS4_MAX_UINT64 - range->offset)
1648                 return false;
1649         return true;
1650 }
1651
1652 struct pnfs_layout_segment *
1653 pnfs_layout_process(struct nfs4_layoutget *lgp)
1654 {
1655         struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
1656         struct nfs4_layoutget_res *res = &lgp->res;
1657         struct pnfs_layout_segment *lseg;
1658         struct inode *ino = lo->plh_inode;
1659         LIST_HEAD(free_me);
1660         int status = -EINVAL;
1661
1662         if (!pnfs_sanity_check_layout_range(&res->range))
1663                 goto out;
1664
1665         /* Inject layout blob into I/O device driver */
1666         lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
1667         if (!lseg || IS_ERR(lseg)) {
1668                 if (!lseg)
1669                         status = -ENOMEM;
1670                 else
1671                         status = PTR_ERR(lseg);
1672                 dprintk("%s: Could not allocate layout: error %d\n",
1673                        __func__, status);
1674                 goto out;
1675         }
1676
1677         init_lseg(lo, lseg);
1678         lseg->pls_range = res->range;
1679
1680         spin_lock(&ino->i_lock);
1681         if (pnfs_layoutgets_blocked(lo)) {
1682                 dprintk("%s forget reply due to state\n", __func__);
1683                 goto out_forget_reply;
1684         }
1685
1686         if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
1687                 /* existing state ID, make sure the sequence number matches. */
1688                 if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
1689                         dprintk("%s forget reply due to sequence\n", __func__);
1690                         goto out_forget_reply;
1691                 }
1692                 pnfs_set_layout_stateid(lo, &res->stateid, false);
1693         } else {
1694                 /*
1695                  * We got an entirely new state ID.  Mark all segments for the
1696                  * inode invalid, and don't bother validating the stateid
1697                  * sequence number.
1698                  */
1699                 pnfs_mark_matching_lsegs_invalid(lo, &free_me, NULL);
1700
1701                 nfs4_stateid_copy(&lo->plh_stateid, &res->stateid);
1702                 lo->plh_barrier = be32_to_cpu(res->stateid.seqid);
1703         }
1704
1705         clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
1706
1707         pnfs_get_lseg(lseg);
1708         pnfs_layout_insert_lseg(lo, lseg, &free_me);
1709
1710         if (res->return_on_close)
1711                 set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
1712
1713         spin_unlock(&ino->i_lock);
1714         pnfs_free_lseg_list(&free_me);
1715         return lseg;
1716 out:
1717         return ERR_PTR(status);
1718
1719 out_forget_reply:
1720         spin_unlock(&ino->i_lock);
1721         lseg->pls_layout = lo;
1722         NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
1723         goto out;
1724 }
1725
1726 static void
1727 pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
1728                                 struct list_head *tmp_list,
1729                                 struct pnfs_layout_range *return_range)
1730 {
1731         struct pnfs_layout_segment *lseg, *next;
1732
1733         dprintk("%s:Begin lo %p\n", __func__, lo);
1734
1735         if (list_empty(&lo->plh_segs))
1736                 return;
1737
1738         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
1739                 if (should_free_lseg(&lseg->pls_range, return_range)) {
1740                         dprintk("%s: marking lseg %p iomode %d "
1741                                 "offset %llu length %llu\n", __func__,
1742                                 lseg, lseg->pls_range.iomode,
1743                                 lseg->pls_range.offset,
1744                                 lseg->pls_range.length);
1745                         set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1746                         mark_lseg_invalid(lseg, tmp_list);
1747                         set_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
1748                                         &lo->plh_flags);
1749                 }
1750 }
1751
1752 void pnfs_error_mark_layout_for_return(struct inode *inode,
1753                                        struct pnfs_layout_segment *lseg)
1754 {
1755         struct pnfs_layout_hdr *lo = NFS_I(inode)->layout;
1756         int iomode = pnfs_iomode_to_fail_bit(lseg->pls_range.iomode);
1757         struct pnfs_layout_range range = {
1758                 .iomode = lseg->pls_range.iomode,
1759                 .offset = 0,
1760                 .length = NFS4_MAX_UINT64,
1761         };
1762         LIST_HEAD(free_me);
1763
1764         spin_lock(&inode->i_lock);
1765         /* set failure bit so that pnfs path will be retried later */
1766         pnfs_layout_set_fail_bit(lo, iomode);
1767         if (lo->plh_return_iomode == 0)
1768                 lo->plh_return_iomode = range.iomode;
1769         else if (lo->plh_return_iomode != range.iomode)
1770                 lo->plh_return_iomode = IOMODE_ANY;
1771         /*
1772          * mark all matching lsegs so that we are sure to have no live
1773          * segments at hand when sending layoutreturn. See pnfs_put_lseg()
1774          * for how it works.
1775          */
1776         pnfs_mark_matching_lsegs_return(lo, &free_me, &range);
1777         spin_unlock(&inode->i_lock);
1778         pnfs_free_lseg_list(&free_me);
1779 }
1780 EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
1781
1782 void
1783 pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
1784 {
1785         u64 rd_size = req->wb_bytes;
1786
1787         if (pgio->pg_lseg == NULL) {
1788                 if (pgio->pg_dreq == NULL)
1789                         rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
1790                 else
1791                         rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
1792
1793                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
1794                                                    req->wb_context,
1795                                                    req_offset(req),
1796                                                    rd_size,
1797                                                    IOMODE_READ,
1798                                                    GFP_KERNEL);
1799         }
1800         /* If no lseg, fall back to read through mds */
1801         if (pgio->pg_lseg == NULL)
1802                 nfs_pageio_reset_read_mds(pgio);
1803
1804 }
1805 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
1806
1807 void
1808 pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
1809                            struct nfs_page *req, u64 wb_size)
1810 {
1811         if (pgio->pg_lseg == NULL)
1812                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
1813                                                    req->wb_context,
1814                                                    req_offset(req),
1815                                                    wb_size,
1816                                                    IOMODE_RW,
1817                                                    GFP_NOFS);
1818         /* If no lseg, fall back to write through mds */
1819         if (pgio->pg_lseg == NULL)
1820                 nfs_pageio_reset_write_mds(pgio);
1821 }
1822 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
1823
1824 void
1825 pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
1826 {
1827         if (desc->pg_lseg) {
1828                 pnfs_put_lseg(desc->pg_lseg);
1829                 desc->pg_lseg = NULL;
1830         }
1831 }
1832 EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
1833
1834 /*
1835  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
1836  * of bytes (maximum @req->wb_bytes) that can be coalesced.
1837  */
1838 size_t
1839 pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
1840                      struct nfs_page *prev, struct nfs_page *req)
1841 {
1842         unsigned int size;
1843         u64 seg_end, req_start, seg_left;
1844
1845         size = nfs_generic_pg_test(pgio, prev, req);
1846         if (!size)
1847                 return 0;
1848
1849         /*
1850          * 'size' contains the number of bytes left in the current page (up
1851          * to the original size asked for in @req->wb_bytes).
1852          *
1853          * Calculate how many bytes are left in the layout segment
1854          * and if there are less bytes than 'size', return that instead.
1855          *
1856          * Please also note that 'end_offset' is actually the offset of the
1857          * first byte that lies outside the pnfs_layout_range. FIXME?
1858          *
1859          */
1860         if (pgio->pg_lseg) {
1861                 seg_end = end_offset(pgio->pg_lseg->pls_range.offset,
1862                                      pgio->pg_lseg->pls_range.length);
1863                 req_start = req_offset(req);
1864                 WARN_ON_ONCE(req_start >= seg_end);
1865                 /* start of request is past the last byte of this segment */
1866                 if (req_start >= seg_end) {
1867                         /* reference the new lseg */
1868                         if (pgio->pg_ops->pg_cleanup)
1869                                 pgio->pg_ops->pg_cleanup(pgio);
1870                         if (pgio->pg_ops->pg_init)
1871                                 pgio->pg_ops->pg_init(pgio, req);
1872                         return 0;
1873                 }
1874
1875                 /* adjust 'size' iff there are fewer bytes left in the
1876                  * segment than what nfs_generic_pg_test returned */
1877                 seg_left = seg_end - req_start;
1878                 if (seg_left < size)
1879                         size = (unsigned int)seg_left;
1880         }
1881
1882         return size;
1883 }
1884 EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
1885
1886 int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
1887 {
1888         struct nfs_pageio_descriptor pgio;
1889
1890         /* Resend all requests through the MDS */
1891         nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
1892                               hdr->completion_ops);
1893         set_bit(NFS_CONTEXT_RESEND_WRITES, &hdr->args.context->flags);
1894         return nfs_pageio_resend(&pgio, hdr);
1895 }
1896 EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
1897
1898 static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
1899 {
1900
1901         dprintk("pnfs write error = %d\n", hdr->pnfs_error);
1902         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
1903             PNFS_LAYOUTRET_ON_ERROR) {
1904                 pnfs_return_layout(hdr->inode);
1905         }
1906         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
1907                 hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
1908 }
1909
1910 /*
1911  * Called by non rpc-based layout drivers
1912  */
1913 void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
1914 {
1915         if (likely(!hdr->pnfs_error)) {
1916                 pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
1917                                 hdr->mds_offset + hdr->res.count);
1918                 hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
1919         }
1920         trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
1921         if (unlikely(hdr->pnfs_error))
1922                 pnfs_ld_handle_write_error(hdr);
1923         hdr->mds_ops->rpc_release(hdr);
1924 }
1925 EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
1926
1927 static void
1928 pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
1929                 struct nfs_pgio_header *hdr)
1930 {
1931         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1932
1933         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1934                 list_splice_tail_init(&hdr->pages, &mirror->pg_list);
1935                 nfs_pageio_reset_write_mds(desc);
1936                 mirror->pg_recoalesce = 1;
1937         }
1938         nfs_pgio_data_destroy(hdr);
1939         hdr->release(hdr);
1940 }
1941
1942 static enum pnfs_try_status
1943 pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
1944                         const struct rpc_call_ops *call_ops,
1945                         struct pnfs_layout_segment *lseg,
1946                         int how)
1947 {
1948         struct inode *inode = hdr->inode;
1949         enum pnfs_try_status trypnfs;
1950         struct nfs_server *nfss = NFS_SERVER(inode);
1951
1952         hdr->mds_ops = call_ops;
1953
1954         dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
1955                 inode->i_ino, hdr->args.count, hdr->args.offset, how);
1956         trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
1957         if (trypnfs != PNFS_NOT_ATTEMPTED)
1958                 nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
1959         dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
1960         return trypnfs;
1961 }
1962
1963 static void
1964 pnfs_do_write(struct nfs_pageio_descriptor *desc,
1965               struct nfs_pgio_header *hdr, int how)
1966 {
1967         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
1968         struct pnfs_layout_segment *lseg = desc->pg_lseg;
1969         enum pnfs_try_status trypnfs;
1970
1971         trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
1972         if (trypnfs == PNFS_NOT_ATTEMPTED)
1973                 pnfs_write_through_mds(desc, hdr);
1974 }
1975
1976 static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
1977 {
1978         pnfs_put_lseg(hdr->lseg);
1979         nfs_pgio_header_free(hdr);
1980 }
1981
1982 int
1983 pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
1984 {
1985         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1986
1987         struct nfs_pgio_header *hdr;
1988         int ret;
1989
1990         hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
1991         if (!hdr) {
1992                 desc->pg_completion_ops->error_cleanup(&mirror->pg_list);
1993                 return -ENOMEM;
1994         }
1995         nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
1996
1997         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
1998         ret = nfs_generic_pgio(desc, hdr);
1999         if (!ret)
2000                 pnfs_do_write(desc, hdr, desc->pg_ioflags);
2001
2002         return ret;
2003 }
2004 EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
2005
2006 int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
2007 {
2008         struct nfs_pageio_descriptor pgio;
2009
2010         /* Resend all requests through the MDS */
2011         nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
2012         return nfs_pageio_resend(&pgio, hdr);
2013 }
2014 EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
2015
2016 static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
2017 {
2018         dprintk("pnfs read error = %d\n", hdr->pnfs_error);
2019         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2020             PNFS_LAYOUTRET_ON_ERROR) {
2021                 pnfs_return_layout(hdr->inode);
2022         }
2023         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2024                 hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
2025 }
2026
2027 /*
2028  * Called by non rpc-based layout drivers
2029  */
2030 void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
2031 {
2032         if (likely(!hdr->pnfs_error)) {
2033                 __nfs4_read_done_cb(hdr);
2034                 hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2035         }
2036         trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
2037         if (unlikely(hdr->pnfs_error))
2038                 pnfs_ld_handle_read_error(hdr);
2039         hdr->mds_ops->rpc_release(hdr);
2040 }
2041 EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
2042
2043 static void
2044 pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
2045                 struct nfs_pgio_header *hdr)
2046 {
2047         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2048
2049         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2050                 list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2051                 nfs_pageio_reset_read_mds(desc);
2052                 mirror->pg_recoalesce = 1;
2053         }
2054         nfs_pgio_data_destroy(hdr);
2055         hdr->release(hdr);
2056 }
2057
2058 /*
2059  * Call the appropriate parallel I/O subsystem read function.
2060  */
2061 static enum pnfs_try_status
2062 pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
2063                        const struct rpc_call_ops *call_ops,
2064                        struct pnfs_layout_segment *lseg)
2065 {
2066         struct inode *inode = hdr->inode;
2067         struct nfs_server *nfss = NFS_SERVER(inode);
2068         enum pnfs_try_status trypnfs;
2069
2070         hdr->mds_ops = call_ops;
2071
2072         dprintk("%s: Reading ino:%lu %u@%llu\n",
2073                 __func__, inode->i_ino, hdr->args.count, hdr->args.offset);
2074
2075         trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
2076         if (trypnfs != PNFS_NOT_ATTEMPTED)
2077                 nfs_inc_stats(inode, NFSIOS_PNFS_READ);
2078         dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2079         return trypnfs;
2080 }
2081
2082 /* Resend all requests through pnfs. */
2083 int pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr)
2084 {
2085         struct nfs_pageio_descriptor pgio;
2086
2087         nfs_pageio_init_read(&pgio, hdr->inode, false, hdr->completion_ops);
2088         return nfs_pageio_resend(&pgio, hdr);
2089 }
2090 EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
2091
2092 static void
2093 pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
2094 {
2095         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2096         struct pnfs_layout_segment *lseg = desc->pg_lseg;
2097         enum pnfs_try_status trypnfs;
2098         int err = 0;
2099
2100         trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
2101         if (trypnfs == PNFS_TRY_AGAIN)
2102                 err = pnfs_read_resend_pnfs(hdr);
2103         if (trypnfs == PNFS_NOT_ATTEMPTED || err)
2104                 pnfs_read_through_mds(desc, hdr);
2105 }
2106
2107 static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
2108 {
2109         pnfs_put_lseg(hdr->lseg);
2110         nfs_pgio_header_free(hdr);
2111 }
2112
2113 int
2114 pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
2115 {
2116         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2117
2118         struct nfs_pgio_header *hdr;
2119         int ret;
2120
2121         hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2122         if (!hdr) {
2123                 desc->pg_completion_ops->error_cleanup(&mirror->pg_list);
2124                 return -ENOMEM;
2125         }
2126         nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
2127         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2128         ret = nfs_generic_pgio(desc, hdr);
2129         if (!ret)
2130                 pnfs_do_read(desc, hdr);
2131         return ret;
2132 }
2133 EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
2134
2135 static void pnfs_clear_layoutcommitting(struct inode *inode)
2136 {
2137         unsigned long *bitlock = &NFS_I(inode)->flags;
2138
2139         clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
2140         smp_mb__after_atomic();
2141         wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
2142 }
2143
2144 /*
2145  * There can be multiple RW segments.
2146  */
2147 static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
2148 {
2149         struct pnfs_layout_segment *lseg;
2150
2151         list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
2152                 if (lseg->pls_range.iomode == IOMODE_RW &&
2153                     test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
2154                         list_add(&lseg->pls_lc_list, listp);
2155         }
2156 }
2157
2158 static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
2159 {
2160         struct pnfs_layout_segment *lseg, *tmp;
2161
2162         /* Matched by references in pnfs_set_layoutcommit */
2163         list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
2164                 list_del_init(&lseg->pls_lc_list);
2165                 pnfs_put_lseg(lseg);
2166         }
2167
2168         pnfs_clear_layoutcommitting(inode);
2169 }
2170
2171 void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
2172 {
2173         pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
2174 }
2175 EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
2176
2177 void
2178 pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
2179                 loff_t end_pos)
2180 {
2181         struct nfs_inode *nfsi = NFS_I(inode);
2182         bool mark_as_dirty = false;
2183
2184         spin_lock(&inode->i_lock);
2185         if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
2186                 nfsi->layout->plh_lwb = end_pos;
2187                 mark_as_dirty = true;
2188                 dprintk("%s: Set layoutcommit for inode %lu ",
2189                         __func__, inode->i_ino);
2190         } else if (end_pos > nfsi->layout->plh_lwb)
2191                 nfsi->layout->plh_lwb = end_pos;
2192         if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
2193                 /* references matched in nfs4_layoutcommit_release */
2194                 pnfs_get_lseg(lseg);
2195         }
2196         spin_unlock(&inode->i_lock);
2197         dprintk("%s: lseg %p end_pos %llu\n",
2198                 __func__, lseg, nfsi->layout->plh_lwb);
2199
2200         /* if pnfs_layoutcommit_inode() runs between inode locks, the next one
2201          * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
2202         if (mark_as_dirty)
2203                 mark_inode_dirty_sync(inode);
2204 }
2205 EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
2206
2207 void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
2208 {
2209         struct nfs_server *nfss = NFS_SERVER(data->args.inode);
2210
2211         if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
2212                 nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
2213         pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
2214 }
2215
2216 /*
2217  * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
2218  * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
2219  * data to disk to allow the server to recover the data if it crashes.
2220  * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
2221  * is off, and a COMMIT is sent to a data server, or
2222  * if WRITEs to a data server return NFS_DATA_SYNC.
2223  */
2224 int
2225 pnfs_layoutcommit_inode(struct inode *inode, bool sync)
2226 {
2227         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2228         struct nfs4_layoutcommit_data *data;
2229         struct nfs_inode *nfsi = NFS_I(inode);
2230         loff_t end_pos;
2231         int status;
2232
2233         if (!pnfs_layoutcommit_outstanding(inode))
2234                 return 0;
2235
2236         dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
2237
2238         status = -EAGAIN;
2239         if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
2240                 if (!sync)
2241                         goto out;
2242                 status = wait_on_bit_lock_action(&nfsi->flags,
2243                                 NFS_INO_LAYOUTCOMMITTING,
2244                                 nfs_wait_bit_killable,
2245                                 TASK_KILLABLE);
2246                 if (status)
2247                         goto out;
2248         }
2249
2250         status = -ENOMEM;
2251         /* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
2252         data = kzalloc(sizeof(*data), GFP_NOFS);
2253         if (!data)
2254                 goto clear_layoutcommitting;
2255
2256         status = 0;
2257         spin_lock(&inode->i_lock);
2258         if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
2259                 goto out_unlock;
2260
2261         INIT_LIST_HEAD(&data->lseg_list);
2262         pnfs_list_write_lseg(inode, &data->lseg_list);
2263
2264         end_pos = nfsi->layout->plh_lwb;
2265
2266         nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
2267         spin_unlock(&inode->i_lock);
2268
2269         data->args.inode = inode;
2270         data->cred = get_rpccred(nfsi->layout->plh_lc_cred);
2271         nfs_fattr_init(&data->fattr);
2272         data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
2273         data->res.fattr = &data->fattr;
2274         data->args.lastbytewritten = end_pos - 1;
2275         data->res.server = NFS_SERVER(inode);
2276
2277         if (ld->prepare_layoutcommit) {
2278                 status = ld->prepare_layoutcommit(&data->args);
2279                 if (status) {
2280                         put_rpccred(data->cred);
2281                         spin_lock(&inode->i_lock);
2282                         set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
2283                         if (end_pos > nfsi->layout->plh_lwb)
2284                                 nfsi->layout->plh_lwb = end_pos;
2285                         goto out_unlock;
2286                 }
2287         }
2288
2289
2290         status = nfs4_proc_layoutcommit(data, sync);
2291 out:
2292         if (status)
2293                 mark_inode_dirty_sync(inode);
2294         dprintk("<-- %s status %d\n", __func__, status);
2295         return status;
2296 out_unlock:
2297         spin_unlock(&inode->i_lock);
2298         kfree(data);
2299 clear_layoutcommitting:
2300         pnfs_clear_layoutcommitting(inode);
2301         goto out;
2302 }
2303 EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
2304
2305 int
2306 pnfs_generic_sync(struct inode *inode, bool datasync)
2307 {
2308         return pnfs_layoutcommit_inode(inode, true);
2309 }
2310 EXPORT_SYMBOL_GPL(pnfs_generic_sync);
2311
2312 struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
2313 {
2314         struct nfs4_threshold *thp;
2315
2316         thp = kzalloc(sizeof(*thp), GFP_NOFS);
2317         if (!thp) {
2318                 dprintk("%s mdsthreshold allocation failed\n", __func__);
2319                 return NULL;
2320         }
2321         return thp;
2322 }
2323
2324 #if IS_ENABLED(CONFIG_NFS_V4_2)
2325 int
2326 pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
2327 {
2328         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2329         struct nfs_server *server = NFS_SERVER(inode);
2330         struct nfs_inode *nfsi = NFS_I(inode);
2331         struct nfs42_layoutstat_data *data;
2332         struct pnfs_layout_hdr *hdr;
2333         int status = 0;
2334
2335         if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
2336                 goto out;
2337
2338         if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
2339                 goto out;
2340
2341         if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
2342                 goto out;
2343
2344         spin_lock(&inode->i_lock);
2345         if (!NFS_I(inode)->layout) {
2346                 spin_unlock(&inode->i_lock);
2347                 goto out;
2348         }
2349         hdr = NFS_I(inode)->layout;
2350         pnfs_get_layout_hdr(hdr);
2351         spin_unlock(&inode->i_lock);
2352
2353         data = kzalloc(sizeof(*data), gfp_flags);
2354         if (!data) {
2355                 status = -ENOMEM;
2356                 goto out_put;
2357         }
2358
2359         data->args.fh = NFS_FH(inode);
2360         data->args.inode = inode;
2361         nfs4_stateid_copy(&data->args.stateid, &hdr->plh_stateid);
2362         status = ld->prepare_layoutstats(&data->args);
2363         if (status)
2364                 goto out_free;
2365
2366         status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
2367
2368 out:
2369         dprintk("%s returns %d\n", __func__, status);
2370         return status;
2371
2372 out_free:
2373         kfree(data);
2374 out_put:
2375         pnfs_put_layout_hdr(hdr);
2376         smp_mb__before_atomic();
2377         clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
2378         smp_mb__after_atomic();
2379         goto out;
2380 }
2381 EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
2382 #endif
2383
2384 unsigned int layoutstats_timer;
2385 module_param(layoutstats_timer, uint, 0644);
2386 EXPORT_SYMBOL_GPL(layoutstats_timer);