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