fs/nfs/pnfs.c

   1 /*
   2  *  pNFS functions to call and manage layout drivers.
   3  *
   4  *  Copyright (c) 2002 [year of first publication]
   5  *  The Regents of the University of Michigan
   6  *  All Rights Reserved
   7  *
   8  *  Dean Hildebrand <dhildebz@umich.edu>
   9  *
  10  *  Permission is granted to use, copy, create derivative works, and
  11  *  redistribute this software and such derivative works for any purpose,
  12  *  so long as the name of the University of Michigan is not used in
  13  *  any advertising or publicity pertaining to the use or distribution
  14  *  of this software without specific, written prior authorization. If
  15  *  the above copyright notice or any other identification of the
  16  *  University of Michigan is included in any copy of any portion of
  17  *  this software, then the disclaimer below must also be included.
  18  *
  19  *  This software is provided as is, without representation or warranty
  20  *  of any kind either express or implied, including without limitation
  21  *  the implied warranties of merchantability, fitness for a particular
  22  *  purpose, or noninfringement.  The Regents of the University of
  23  *  Michigan shall not be liable for any damages, including special,
  24  *  indirect, incidental, or consequential damages, with respect to any
  25  *  claim arising out of or in connection with the use of the software,
  26  *  even if it has been or is hereafter advised of the possibility of
  27  *  such damages.
  28  */
  29
  30 #include <linux/nfs_fs.h>
  31 #include <linux/nfs_page.h>
  32 #include <linux/module.h>
  33 #include <linux/sort.h>
  34 #include "internal.h"
  35 #include "pnfs.h"
  36 #include "iostat.h"
  37 #include "nfs4trace.h"
  38 #include "delegation.h"
  39 #include "nfs42.h"
  40 #include "nfs4_fs.h"
  41
  42 #define NFSDBG_FACILITY         NFSDBG_PNFS
  43 #define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
  44
  45 /* Locking:
  46  *
  47  * pnfs_spinlock:
  48  *      protects pnfs_modules_tbl.
  49  */
  50 static DEFINE_SPINLOCK(pnfs_spinlock);
  51
  52 /*
  53  * pnfs_modules_tbl holds all pnfs modules
  54  */
  55 static LIST_HEAD(pnfs_modules_tbl);
  56
  57 static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo);
  58 static void pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
  59                 struct list_head *free_me,
  60                 const struct pnfs_layout_range *range,
  61                 u32 seq);
  62 static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
  63                                 struct list_head *tmp_list);
  64
  65 /* Return the registered pnfs layout driver module matching given id */
  66 static struct pnfs_layoutdriver_type *
  67 find_pnfs_driver_locked(u32 id)
  68 {
  69         struct pnfs_layoutdriver_type *local;
  70
  71         list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
  72                 if (local->id == id)
  73                         goto out;
  74         local = NULL;
  75 out:
  76         dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
  77         return local;
  78 }
  79
  80 static struct pnfs_layoutdriver_type *
  81 find_pnfs_driver(u32 id)
  82 {
  83         struct pnfs_layoutdriver_type *local;
  84
  85         spin_lock(&pnfs_spinlock);
  86         local = find_pnfs_driver_locked(id);
  87         if (local != NULL && !try_module_get(local->owner)) {
  88                 dprintk("%s: Could not grab reference on module\n", __func__);
  89                 local = NULL;
  90         }
  91         spin_unlock(&pnfs_spinlock);
  92         return local;
  93 }
  94
  95 const struct pnfs_layoutdriver_type *pnfs_find_layoutdriver(u32 id)
  96 {
  97         return find_pnfs_driver(id);
  98 }
  99
 100 void pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type *ld)
 101 {
 102         if (ld)
 103                 module_put(ld->owner);
 104 }
 105
 106 void
 107 unset_pnfs_layoutdriver(struct nfs_server *nfss)
 108 {
 109         if (nfss->pnfs_curr_ld) {
 110                 if (nfss->pnfs_curr_ld->clear_layoutdriver)
 111                         nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
 112                 /* Decrement the MDS count. Purge the deviceid cache if zero */
 113                 if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
 114                         nfs4_deviceid_purge_client(nfss->nfs_client);
 115                 module_put(nfss->pnfs_curr_ld->owner);
 116         }
 117         nfss->pnfs_curr_ld = NULL;
 118 }
 119
 120 /*
 121  * When the server sends a list of layout types, we choose one in the order
 122  * given in the list below.
 123  *
 124  * FIXME: should this list be configurable in some fashion? module param?
 125  *        mount option? something else?
 126  */
 127 static const u32 ld_prefs[] = {
 128         LAYOUT_SCSI,
 129         LAYOUT_BLOCK_VOLUME,
 130         LAYOUT_OSD2_OBJECTS,
 131         LAYOUT_FLEX_FILES,
 132         LAYOUT_NFSV4_1_FILES,
 133         0
 134 };
 135
 136 static int
 137 ld_cmp(const void *e1, const void *e2)
 138 {
 139         u32 ld1 = *((u32 *)e1);
 140         u32 ld2 = *((u32 *)e2);
 141         int i;
 142
 143         for (i = 0; ld_prefs[i] != 0; i++) {
 144                 if (ld1 == ld_prefs[i])
 145                         return -1;
 146
 147                 if (ld2 == ld_prefs[i])
 148                         return 1;
 149         }
 150         return 0;
 151 }
 152
 153 /*
 154  * Try to set the server's pnfs module to the pnfs layout type specified by id.
 155  * Currently only one pNFS layout driver per filesystem is supported.
 156  *
 157  * @ids array of layout types supported by MDS.
 158  */
 159 void
 160 set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
 161                       struct nfs_fsinfo *fsinfo)
 162 {
 163         struct pnfs_layoutdriver_type *ld_type = NULL;
 164         u32 id;
 165         int i;
 166
 167         if (fsinfo->nlayouttypes == 0)
 168                 goto out_no_driver;
 169         if (!(server->nfs_client->cl_exchange_flags &
 170                  (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
 171                 printk(KERN_ERR "NFS: %s: cl_exchange_flags 0x%x\n",
 172                         __func__, server->nfs_client->cl_exchange_flags);
 173                 goto out_no_driver;
 174         }
 175
 176         sort(fsinfo->layouttype, fsinfo->nlayouttypes,
 177                 sizeof(*fsinfo->layouttype), ld_cmp, NULL);
 178
 179         for (i = 0; i < fsinfo->nlayouttypes; i++) {
 180                 id = fsinfo->layouttype[i];
 181                 ld_type = find_pnfs_driver(id);
 182                 if (!ld_type) {
 183                         request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX,
 184                                         id);
 185                         ld_type = find_pnfs_driver(id);
 186                 }
 187                 if (ld_type)
 188                         break;
 189         }
 190
 191         if (!ld_type) {
 192                 dprintk("%s: No pNFS module found!\n", __func__);
 193                 goto out_no_driver;
 194         }
 195
 196         server->pnfs_curr_ld = ld_type;
 197         if (ld_type->set_layoutdriver
 198             && ld_type->set_layoutdriver(server, mntfh)) {
 199                 printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
 200                         "driver %u.\n", __func__, id);
 201                 module_put(ld_type->owner);
 202                 goto out_no_driver;
 203         }
 204         /* Bump the MDS count */
 205         atomic_inc(&server->nfs_client->cl_mds_count);
 206
 207         dprintk("%s: pNFS module for %u set\n", __func__, id);
 208         return;
 209
 210 out_no_driver:
 211         dprintk("%s: Using NFSv4 I/O\n", __func__);
 212         server->pnfs_curr_ld = NULL;
 213 }
 214
 215 int
 216 pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 217 {
 218         int status = -EINVAL;
 219         struct pnfs_layoutdriver_type *tmp;
 220
 221         if (ld_type->id == 0) {
 222                 printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
 223                 return status;
 224         }
 225         if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
 226                 printk(KERN_ERR "NFS: %s Layout driver must provide "
 227                        "alloc_lseg and free_lseg.\n", __func__);
 228                 return status;
 229         }
 230
 231         spin_lock(&pnfs_spinlock);
 232         tmp = find_pnfs_driver_locked(ld_type->id);
 233         if (!tmp) {
 234                 list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
 235                 status = 0;
 236                 dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
 237                         ld_type->name);
 238         } else {
 239                 printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
 240                         __func__, ld_type->id);
 241         }
 242         spin_unlock(&pnfs_spinlock);
 243
 244         return status;
 245 }
 246 EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
 247
 248 void
 249 pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 250 {
 251         dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
 252         spin_lock(&pnfs_spinlock);
 253         list_del(&ld_type->pnfs_tblid);
 254         spin_unlock(&pnfs_spinlock);
 255 }
 256 EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
 257
 258 /*
 259  * pNFS client layout cache
 260  */
 261
 262 /* Need to hold i_lock if caller does not already hold reference */
 263 void
 264 pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
 265 {
 266         refcount_inc(&lo->plh_refcount);
 267 }
 268
 269 static struct pnfs_layout_hdr *
 270 pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
 271 {
 272         struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
 273         return ld->alloc_layout_hdr(ino, gfp_flags);
 274 }
 275
 276 static void
 277 pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
 278 {
 279         struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 280         struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
 281
 282         if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
 283                 struct nfs_client *clp = server->nfs_client;
 284
 285                 spin_lock(&clp->cl_lock);
 286                 list_del_rcu(&lo->plh_layouts);
 287                 spin_unlock(&clp->cl_lock);
 288         }
 289         put_cred(lo->plh_lc_cred);
 290         return ld->free_layout_hdr(lo);
 291 }
 292
 293 static void
 294 pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 295 {
 296         struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
 297         dprintk("%s: freeing layout cache %p\n", __func__, lo);
 298         nfsi->layout = NULL;
 299         /* Reset MDS Threshold I/O counters */
 300         nfsi->write_io = 0;
 301         nfsi->read_io = 0;
 302 }
 303
 304 void
 305 pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
 306 {
 307         struct inode *inode;
 308         unsigned long i_state;
 309
 310         if (!lo)
 311                 return;
 312         inode = lo->plh_inode;
 313         pnfs_layoutreturn_before_put_layout_hdr(lo);
 314
 315         if (refcount_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
 316                 if (!list_empty(&lo->plh_segs))
 317                         WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n");
 318                 pnfs_detach_layout_hdr(lo);
 319                 i_state = inode->i_state;
 320                 spin_unlock(&inode->i_lock);
 321                 pnfs_free_layout_hdr(lo);
 322                 /* Notify pnfs_destroy_layout_final() that we're done */
 323                 if (i_state & (I_FREEING | I_CLEAR))
 324                         wake_up_var(lo);
 325         }
 326 }
 327
 328 static struct inode *
 329 pnfs_grab_inode_layout_hdr(struct pnfs_layout_hdr *lo)
 330 {
 331         struct inode *inode = igrab(lo->plh_inode);
 332         if (inode)
 333                 return inode;
 334         set_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags);
 335         return NULL;
 336 }
 337
 338 /*
 339  * Compare 2 layout stateid sequence ids, to see which is newer,
 340  * taking into account wraparound issues.
 341  */
 342 static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
 343 {
 344         return (s32)(s1 - s2) > 0;
 345 }
 346
 347 static void pnfs_barrier_update(struct pnfs_layout_hdr *lo, u32 newseq)
 348 {
 349         if (pnfs_seqid_is_newer(newseq, lo->plh_barrier) || !lo->plh_barrier)
 350                 lo->plh_barrier = newseq;
 351 }
 352
 353 static void
 354 pnfs_set_plh_return_info(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode,
 355                          u32 seq)
 356 {
 357         if (lo->plh_return_iomode != 0 && lo->plh_return_iomode != iomode)
 358                 iomode = IOMODE_ANY;
 359         lo->plh_return_iomode = iomode;
 360         set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 361         /*
 362          * We must set lo->plh_return_seq to avoid livelocks with
 363          * pnfs_layout_need_return()
 364          */
 365         if (seq == 0)
 366                 seq = be32_to_cpu(lo->plh_stateid.seqid);
 367         if (!lo->plh_return_seq || pnfs_seqid_is_newer(seq, lo->plh_return_seq))
 368                 lo->plh_return_seq = seq;
 369         pnfs_barrier_update(lo, seq);
 370 }
 371
 372 static void
 373 pnfs_clear_layoutreturn_info(struct pnfs_layout_hdr *lo)
 374 {
 375         struct pnfs_layout_segment *lseg;
 376         lo->plh_return_iomode = 0;
 377         lo->plh_return_seq = 0;
 378         clear_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 379         list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
 380                 if (!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 381                         continue;
 382                 pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 383         }
 384 }
 385
 386 static void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
 387 {
 388         clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
 389         clear_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags);
 390         smp_mb__after_atomic();
 391         wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
 392         rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
 393 }
 394
 395 static void
 396 pnfs_clear_lseg_state(struct pnfs_layout_segment *lseg,
 397                 struct list_head *free_me)
 398 {
 399         clear_bit(NFS_LSEG_ROC, &lseg->pls_flags);
 400         clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
 401         if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 402                 pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 403         if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 404                 pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 405 }
 406
 407 /*
 408  * Update the seqid of a layout stateid after receiving
 409  * NFS4ERR_OLD_STATEID
 410  */
 411 bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
 412                 struct pnfs_layout_range *dst_range,
 413                 struct inode *inode)
 414 {
 415         struct pnfs_layout_hdr *lo;
 416         struct pnfs_layout_range range = {
 417                 .iomode = IOMODE_ANY,
 418                 .offset = 0,
 419                 .length = NFS4_MAX_UINT64,
 420         };
 421         bool ret = false;
 422         LIST_HEAD(head);
 423         int err;
 424
 425         spin_lock(&inode->i_lock);
 426         lo = NFS_I(inode)->layout;
 427         if (lo &&  pnfs_layout_is_valid(lo) &&
 428             nfs4_stateid_match_other(dst, &lo->plh_stateid)) {
 429                 /* Is our call using the most recent seqid? If so, bump it */
 430                 if (!nfs4_stateid_is_newer(&lo->plh_stateid, dst)) {
 431                         nfs4_stateid_seqid_inc(dst);
 432                         ret = true;
 433                         goto out;
 434                 }
 435                 /* Try to update the seqid to the most recent */
 436                 err = pnfs_mark_matching_lsegs_return(lo, &head, &range, 0);
 437                 if (err != -EBUSY) {
 438                         dst->seqid = lo->plh_stateid.seqid;
 439                         *dst_range = range;
 440                         ret = true;
 441                 }
 442         }
 443 out:
 444         spin_unlock(&inode->i_lock);
 445         pnfs_free_lseg_list(&head);
 446         return ret;
 447 }
 448
 449 /*
 450  * Mark a pnfs_layout_hdr and all associated layout segments as invalid
 451  *
 452  * In order to continue using the pnfs_layout_hdr, a full recovery
 453  * is required.
 454  * Note that caller must hold inode->i_lock.
 455  */
 456 int
 457 pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
 458                 struct list_head *lseg_list)
 459 {
 460         struct pnfs_layout_range range = {
 461                 .iomode = IOMODE_ANY,
 462                 .offset = 0,
 463                 .length = NFS4_MAX_UINT64,
 464         };
 465         struct pnfs_layout_segment *lseg, *next;
 466
 467         set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 468         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 469                 pnfs_clear_lseg_state(lseg, lseg_list);
 470         pnfs_clear_layoutreturn_info(lo);
 471         pnfs_free_returned_lsegs(lo, lseg_list, &range, 0);
 472         set_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags);
 473         if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) &&
 474             !test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
 475                 pnfs_clear_layoutreturn_waitbit(lo);
 476         return !list_empty(&lo->plh_segs);
 477 }
 478
 479 static int
 480 pnfs_iomode_to_fail_bit(u32 iomode)
 481 {
 482         return iomode == IOMODE_RW ?
 483                 NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 484 }
 485
 486 static void
 487 pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 488 {
 489         lo->plh_retry_timestamp = jiffies;
 490         if (!test_and_set_bit(fail_bit, &lo->plh_flags))
 491                 refcount_inc(&lo->plh_refcount);
 492 }
 493
 494 static void
 495 pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 496 {
 497         if (test_and_clear_bit(fail_bit, &lo->plh_flags))
 498                 refcount_dec(&lo->plh_refcount);
 499 }
 500
 501 static void
 502 pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 503 {
 504         struct inode *inode = lo->plh_inode;
 505         struct pnfs_layout_range range = {
 506                 .iomode = iomode,
 507                 .offset = 0,
 508                 .length = NFS4_MAX_UINT64,
 509         };
 510         LIST_HEAD(head);
 511
 512         spin_lock(&inode->i_lock);
 513         pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
 514         pnfs_mark_matching_lsegs_return(lo, &head, &range, 0);
 515         spin_unlock(&inode->i_lock);
 516         pnfs_free_lseg_list(&head);
 517         dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
 518                         iomode == IOMODE_RW ?  "RW" : "READ");
 519 }
 520
 521 static bool
 522 pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 523 {
 524         unsigned long start, end;
 525         int fail_bit = pnfs_iomode_to_fail_bit(iomode);
 526
 527         if (test_bit(fail_bit, &lo->plh_flags) == 0)
 528                 return false;
 529         end = jiffies;
 530         start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
 531         if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
 532                 /* It is time to retry the failed layoutgets */
 533                 pnfs_layout_clear_fail_bit(lo, fail_bit);
 534                 return false;
 535         }
 536         return true;
 537 }
 538
 539 static void
 540 pnfs_init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg,
 541                 const struct pnfs_layout_range *range,
 542                 const nfs4_stateid *stateid)
 543 {
 544         INIT_LIST_HEAD(&lseg->pls_list);
 545         INIT_LIST_HEAD(&lseg->pls_lc_list);
 546         INIT_LIST_HEAD(&lseg->pls_commits);
 547         refcount_set(&lseg->pls_refcount, 1);
 548         set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
 549         lseg->pls_layout = lo;
 550         lseg->pls_range = *range;
 551         lseg->pls_seq = be32_to_cpu(stateid->seqid);
 552 }
 553
 554 static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
 555 {
 556         if (lseg != NULL) {
 557                 struct inode *inode = lseg->pls_layout->plh_inode;
 558                 NFS_SERVER(inode)->pnfs_curr_ld->free_lseg(lseg);
 559         }
 560 }
 561
 562 static void
 563 pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 564                 struct pnfs_layout_segment *lseg)
 565 {
 566         WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 567         list_del_init(&lseg->pls_list);
 568         /* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 569         refcount_dec(&lo->plh_refcount);
 570         if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 571                 return;
 572         if (list_empty(&lo->plh_segs) &&
 573             !test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
 574             !test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
 575                 if (atomic_read(&lo->plh_outstanding) == 0)
 576                         set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 577                 clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 578         }
 579 }
 580
 581 static bool
 582 pnfs_cache_lseg_for_layoutreturn(struct pnfs_layout_hdr *lo,
 583                 struct pnfs_layout_segment *lseg)
 584 {
 585         if (test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
 586             pnfs_layout_is_valid(lo)) {
 587                 pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 588                 list_move_tail(&lseg->pls_list, &lo->plh_return_segs);
 589                 return true;
 590         }
 591         return false;
 592 }
 593
 594 void
 595 pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 596 {
 597         struct pnfs_layout_hdr *lo;
 598         struct inode *inode;
 599
 600         if (!lseg)
 601                 return;
 602
 603         dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 604                 refcount_read(&lseg->pls_refcount),
 605                 test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 606
 607         lo = lseg->pls_layout;
 608         inode = lo->plh_inode;
 609
 610         if (refcount_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
 611                 pnfs_get_layout_hdr(lo);
 612                 pnfs_layout_remove_lseg(lo, lseg);
 613                 if (pnfs_cache_lseg_for_layoutreturn(lo, lseg))
 614                         lseg = NULL;
 615                 spin_unlock(&inode->i_lock);
 616                 pnfs_free_lseg(lseg);
 617                 pnfs_put_layout_hdr(lo);
 618         }
 619 }
 620 EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 621
 622 /*
 623  * is l2 fully contained in l1?
 624  *   start1                             end1
 625  *   [----------------------------------)
 626  *           start2           end2
 627  *           [----------------)
 628  */
 629 static bool
 630 pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
 631                  const struct pnfs_layout_range *l2)
 632 {
 633         u64 start1 = l1->offset;
 634         u64 end1 = pnfs_end_offset(start1, l1->length);
 635         u64 start2 = l2->offset;
 636         u64 end2 = pnfs_end_offset(start2, l2->length);
 637
 638         return (start1 <= start2) && (end1 >= end2);
 639 }
 640
 641 static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
 642                 struct list_head *tmp_list)
 643 {
 644         if (!refcount_dec_and_test(&lseg->pls_refcount))
 645                 return false;
 646         pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
 647         list_add(&lseg->pls_list, tmp_list);
 648         return true;
 649 }
 650
 651 /* Returns 1 if lseg is removed from list, 0 otherwise */
 652 static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
 653                              struct list_head *tmp_list)
 654 {
 655         int rv = 0;
 656
 657         if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 658                 /* Remove the reference keeping the lseg in the
 659                  * list.  It will now be removed when all
 660                  * outstanding io is finished.
 661                  */
 662                 dprintk("%s: lseg %p ref %d\n", __func__, lseg,
 663                         refcount_read(&lseg->pls_refcount));
 664                 if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
 665                         rv = 1;
 666         }
 667         return rv;
 668 }
 669
 670 static bool
 671 pnfs_should_free_range(const struct pnfs_layout_range *lseg_range,
 672                  const struct pnfs_layout_range *recall_range)
 673 {
 674         return (recall_range->iomode == IOMODE_ANY ||
 675                 lseg_range->iomode == recall_range->iomode) &&
 676                pnfs_lseg_range_intersecting(lseg_range, recall_range);
 677 }
 678
 679 static bool
 680 pnfs_match_lseg_recall(const struct pnfs_layout_segment *lseg,
 681                 const struct pnfs_layout_range *recall_range,
 682                 u32 seq)
 683 {
 684         if (seq != 0 && pnfs_seqid_is_newer(lseg->pls_seq, seq))
 685                 return false;
 686         if (recall_range == NULL)
 687                 return true;
 688         return pnfs_should_free_range(&lseg->pls_range, recall_range);
 689 }
 690
 691 /**
 692  * pnfs_mark_matching_lsegs_invalid - tear down lsegs or mark them for later
 693  * @lo: layout header containing the lsegs
 694  * @tmp_list: list head where doomed lsegs should go
 695  * @recall_range: optional recall range argument to match (may be NULL)
 696  * @seq: only invalidate lsegs obtained prior to this sequence (may be 0)
 697  *
 698  * Walk the list of lsegs in the layout header, and tear down any that should
 699  * be destroyed. If "recall_range" is specified then the segment must match
 700  * that range. If "seq" is non-zero, then only match segments that were handed
 701  * out at or before that sequence.
 702  *
 703  * Returns number of matching invalid lsegs remaining in list after scanning
 704  * it and purging them.
 705  */
 706 int
 707 pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 708                             struct list_head *tmp_list,
 709                             const struct pnfs_layout_range *recall_range,
 710                             u32 seq)
 711 {
 712         struct pnfs_layout_segment *lseg, *next;
 713         struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 714         int remaining = 0;
 715
 716         dprintk("%s:Begin lo %p\n", __func__, lo);
 717
 718         if (list_empty(&lo->plh_segs))
 719                 return 0;
 720         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 721                 if (pnfs_match_lseg_recall(lseg, recall_range, seq)) {
 722                         dprintk("%s: freeing lseg %p iomode %d seq %u "
 723                                 "offset %llu length %llu\n", __func__,
 724                                 lseg, lseg->pls_range.iomode, lseg->pls_seq,
 725                                 lseg->pls_range.offset, lseg->pls_range.length);
 726                         if (mark_lseg_invalid(lseg, tmp_list))
 727                                 continue;
 728                         remaining++;
 729                         pnfs_lseg_cancel_io(server, lseg);
 730                 }
 731         dprintk("%s:Return %i\n", __func__, remaining);
 732         return remaining;
 733 }
 734
 735 static void
 736 pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
 737                 struct list_head *free_me,
 738                 const struct pnfs_layout_range *range,
 739                 u32 seq)
 740 {
 741         struct pnfs_layout_segment *lseg, *next;
 742
 743         list_for_each_entry_safe(lseg, next, &lo->plh_return_segs, pls_list) {
 744                 if (pnfs_match_lseg_recall(lseg, range, seq))
 745                         list_move_tail(&lseg->pls_list, free_me);
 746         }
 747 }
 748
 749 /* note free_me must contain lsegs from a single layout_hdr */
 750 void
 751 pnfs_free_lseg_list(struct list_head *free_me)
 752 {
 753         struct pnfs_layout_segment *lseg, *tmp;
 754
 755         if (list_empty(free_me))
 756                 return;
 757
 758         list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
 759                 list_del(&lseg->pls_list);
 760                 pnfs_free_lseg(lseg);
 761         }
 762 }
 763
 764 static struct pnfs_layout_hdr *__pnfs_destroy_layout(struct nfs_inode *nfsi)
 765 {
 766         struct pnfs_layout_hdr *lo;
 767         LIST_HEAD(tmp_list);
 768
 769         spin_lock(&nfsi->vfs_inode.i_lock);
 770         lo = nfsi->layout;
 771         if (lo) {
 772                 pnfs_get_layout_hdr(lo);
 773                 pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
 774                 pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
 775                 pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
 776                 spin_unlock(&nfsi->vfs_inode.i_lock);
 777                 pnfs_free_lseg_list(&tmp_list);
 778                 nfs_commit_inode(&nfsi->vfs_inode, 0);
 779                 pnfs_put_layout_hdr(lo);
 780         } else
 781                 spin_unlock(&nfsi->vfs_inode.i_lock);
 782         return lo;
 783 }
 784
 785 void pnfs_destroy_layout(struct nfs_inode *nfsi)
 786 {
 787         __pnfs_destroy_layout(nfsi);
 788 }
 789 EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
 790
 791 static bool pnfs_layout_removed(struct nfs_inode *nfsi,
 792                                 struct pnfs_layout_hdr *lo)
 793 {
 794         bool ret;
 795
 796         spin_lock(&nfsi->vfs_inode.i_lock);
 797         ret = nfsi->layout != lo;
 798         spin_unlock(&nfsi->vfs_inode.i_lock);
 799         return ret;
 800 }
 801
 802 void pnfs_destroy_layout_final(struct nfs_inode *nfsi)
 803 {
 804         struct pnfs_layout_hdr *lo = __pnfs_destroy_layout(nfsi);
 805
 806         if (lo)
 807                 wait_var_event(lo, pnfs_layout_removed(nfsi, lo));
 808 }
 809
 810 static bool
 811 pnfs_layout_add_bulk_destroy_list(struct inode *inode,
 812                 struct list_head *layout_list)
 813 {
 814         struct pnfs_layout_hdr *lo;
 815         bool ret = false;
 816
 817         spin_lock(&inode->i_lock);
 818         lo = NFS_I(inode)->layout;
 819         if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
 820                 pnfs_get_layout_hdr(lo);
 821                 list_add(&lo->plh_bulk_destroy, layout_list);
 822                 ret = true;
 823         }
 824         spin_unlock(&inode->i_lock);
 825         return ret;
 826 }
 827
 828 /* Caller must hold rcu_read_lock and clp->cl_lock */
 829 static int
 830 pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
 831                 struct nfs_server *server,
 832                 struct list_head *layout_list)
 833         __must_hold(&clp->cl_lock)
 834         __must_hold(RCU)
 835 {
 836         struct pnfs_layout_hdr *lo, *next;
 837         struct inode *inode;
 838
 839         list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
 840                 if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) ||
 841                     test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) ||
 842                     !list_empty(&lo->plh_bulk_destroy))
 843                         continue;
 844                 /* If the sb is being destroyed, just bail */
 845                 if (!nfs_sb_active(server->super))
 846                         break;
 847                 inode = pnfs_grab_inode_layout_hdr(lo);
 848                 if (inode != NULL) {
 849                         if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags))
 850                                 list_del_rcu(&lo->plh_layouts);
 851                         if (pnfs_layout_add_bulk_destroy_list(inode,
 852                                                 layout_list))
 853                                 continue;
 854                         rcu_read_unlock();
 855                         spin_unlock(&clp->cl_lock);
 856                         iput(inode);
 857                 } else {
 858                         rcu_read_unlock();
 859                         spin_unlock(&clp->cl_lock);
 860                 }
 861                 nfs_sb_deactive(server->super);
 862                 spin_lock(&clp->cl_lock);
 863                 rcu_read_lock();
 864                 return -EAGAIN;
 865         }
 866         return 0;
 867 }
 868
 869 static int
 870 pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
 871                 bool is_bulk_recall)
 872 {
 873         struct pnfs_layout_hdr *lo;
 874         struct inode *inode;
 875         LIST_HEAD(lseg_list);
 876         int ret = 0;
 877
 878         while (!list_empty(layout_list)) {
 879                 lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
 880                                 plh_bulk_destroy);
 881                 dprintk("%s freeing layout for inode %lu\n", __func__,
 882                         lo->plh_inode->i_ino);
 883                 inode = lo->plh_inode;
 884
 885                 pnfs_layoutcommit_inode(inode, false);
 886
 887                 spin_lock(&inode->i_lock);
 888                 list_del_init(&lo->plh_bulk_destroy);
 889                 if (pnfs_mark_layout_stateid_invalid(lo, &lseg_list)) {
 890                         if (is_bulk_recall)
 891                                 set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 892                         ret = -EAGAIN;
 893                 }
 894                 spin_unlock(&inode->i_lock);
 895                 pnfs_free_lseg_list(&lseg_list);
 896                 /* Free all lsegs that are attached to commit buckets */
 897                 nfs_commit_inode(inode, 0);
 898                 pnfs_put_layout_hdr(lo);
 899                 nfs_iput_and_deactive(inode);
 900         }
 901         return ret;
 902 }
 903
 904 int
 905 pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
 906                 struct nfs_fsid *fsid,
 907                 bool is_recall)
 908 {
 909         struct nfs_server *server;
 910         LIST_HEAD(layout_list);
 911
 912         spin_lock(&clp->cl_lock);
 913         rcu_read_lock();
 914 restart:
 915         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 916                 if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
 917                         continue;
 918                 if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 919                                 server,
 920                                 &layout_list) != 0)
 921                         goto restart;
 922         }
 923         rcu_read_unlock();
 924         spin_unlock(&clp->cl_lock);
 925
 926         if (list_empty(&layout_list))
 927                 return 0;
 928         return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 929 }
 930
 931 int
 932 pnfs_destroy_layouts_byclid(struct nfs_client *clp,
 933                 bool is_recall)
 934 {
 935         struct nfs_server *server;
 936         LIST_HEAD(layout_list);
 937
 938         spin_lock(&clp->cl_lock);
 939         rcu_read_lock();
 940 restart:
 941         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 942                 if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 943                                         server,
 944                                         &layout_list) != 0)
 945                         goto restart;
 946         }
 947         rcu_read_unlock();
 948         spin_unlock(&clp->cl_lock);
 949
 950         if (list_empty(&layout_list))
 951                 return 0;
 952         return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 953 }
 954
 955 /*
 956  * Called by the state manager to remove all layouts established under an
 957  * expired lease.
 958  */
 959 void
 960 pnfs_destroy_all_layouts(struct nfs_client *clp)
 961 {
 962         nfs4_deviceid_mark_client_invalid(clp);
 963         nfs4_deviceid_purge_client(clp);
 964
 965         pnfs_destroy_layouts_byclid(clp, false);
 966 }
 967
 968 static void
 969 pnfs_set_layout_cred(struct pnfs_layout_hdr *lo, const struct cred *cred)
 970 {
 971         const struct cred *old;
 972
 973         if (cred && cred_fscmp(lo->plh_lc_cred, cred) != 0) {
 974                 old = xchg(&lo->plh_lc_cred, get_cred(cred));
 975                 put_cred(old);
 976         }
 977 }
 978
 979 /* update lo->plh_stateid with new if is more recent */
 980 void
 981 pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
 982                         const struct cred *cred, bool update_barrier)
 983 {
 984         u32 oldseq = be32_to_cpu(lo->plh_stateid.seqid);
 985         u32 newseq = be32_to_cpu(new->seqid);
 986
 987         if (!pnfs_layout_is_valid(lo)) {
 988                 pnfs_set_layout_cred(lo, cred);
 989                 nfs4_stateid_copy(&lo->plh_stateid, new);
 990                 lo->plh_barrier = newseq;
 991                 pnfs_clear_layoutreturn_info(lo);
 992                 clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 993                 return;
 994         }
 995
 996         if (pnfs_seqid_is_newer(newseq, oldseq))
 997                 nfs4_stateid_copy(&lo->plh_stateid, new);
 998
 999         if (update_barrier) {
1000                 pnfs_barrier_update(lo, newseq);
1001                 return;
1002         }
1003         /*
1004          * Because of wraparound, we want to keep the barrier
1005          * "close" to the current seqids. We really only want to
1006          * get here from a layoutget call.
1007          */
1008         if (atomic_read(&lo->plh_outstanding) == 1)
1009                  pnfs_barrier_update(lo, be32_to_cpu(lo->plh_stateid.seqid));
1010 }
1011
1012 static bool
1013 pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
1014                 const nfs4_stateid *stateid)
1015 {
1016         u32 seqid = be32_to_cpu(stateid->seqid);
1017
1018         return lo->plh_barrier && pnfs_seqid_is_newer(lo->plh_barrier, seqid);
1019 }
1020
1021 /* lget is set to 1 if called from inside send_layoutget call chain */
1022 static bool
1023 pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
1024 {
1025         return lo->plh_block_lgets ||
1026                 test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
1027 }
1028
1029 static struct nfs_server *
1030 pnfs_find_server(struct inode *inode, struct nfs_open_context *ctx)
1031 {
1032         struct nfs_server *server;
1033
1034         if (inode) {
1035                 server = NFS_SERVER(inode);
1036         } else {
1037                 struct dentry *parent_dir = dget_parent(ctx->dentry);
1038                 server = NFS_SERVER(parent_dir->d_inode);
1039                 dput(parent_dir);
1040         }
1041         return server;
1042 }
1043
1044 static void nfs4_free_pages(struct page **pages, size_t size)
1045 {
1046         int i;
1047
1048         if (!pages)
1049                 return;
1050
1051         for (i = 0; i < size; i++) {
1052                 if (!pages[i])
1053                         break;
1054                 __free_page(pages[i]);
1055         }
1056         kfree(pages);
1057 }
1058
1059 static struct page **nfs4_alloc_pages(size_t size, gfp_t gfp_flags)
1060 {
1061         struct page **pages;
1062         int i;
1063
1064         pages = kmalloc_array(size, sizeof(struct page *), gfp_flags);
1065         if (!pages) {
1066                 dprintk("%s: can't alloc array of %zu pages\n", __func__, size);
1067                 return NULL;
1068         }
1069
1070         for (i = 0; i < size; i++) {
1071                 pages[i] = alloc_page(gfp_flags);
1072                 if (!pages[i]) {
1073                         dprintk("%s: failed to allocate page\n", __func__);
1074                         nfs4_free_pages(pages, i);
1075                         return NULL;
1076                 }
1077         }
1078
1079         return pages;
1080 }
1081
1082 static struct nfs4_layoutget *
1083 pnfs_alloc_init_layoutget_args(struct inode *ino,
1084            struct nfs_open_context *ctx,
1085            const nfs4_stateid *stateid,
1086            const struct pnfs_layout_range *range,
1087            gfp_t gfp_flags)
1088 {
1089         struct nfs_server *server = pnfs_find_server(ino, ctx);
1090         size_t max_reply_sz = server->pnfs_curr_ld->max_layoutget_response;
1091         size_t max_pages = max_response_pages(server);
1092         struct nfs4_layoutget *lgp;
1093
1094         dprintk("--> %s\n", __func__);
1095
1096         lgp = kzalloc(sizeof(*lgp), gfp_flags);
1097         if (lgp == NULL)
1098                 return NULL;
1099
1100         if (max_reply_sz) {
1101                 size_t npages = (max_reply_sz + PAGE_SIZE - 1) >> PAGE_SHIFT;
1102                 if (npages < max_pages)
1103                         max_pages = npages;
1104         }
1105
1106         lgp->args.layout.pages = nfs4_alloc_pages(max_pages, gfp_flags);
1107         if (!lgp->args.layout.pages) {
1108                 kfree(lgp);
1109                 return NULL;
1110         }
1111         lgp->args.layout.pglen = max_pages * PAGE_SIZE;
1112         lgp->res.layoutp = &lgp->args.layout;
1113
1114         /* Don't confuse uninitialised result and success */
1115         lgp->res.status = -NFS4ERR_DELAY;
1116
1117         lgp->args.minlength = PAGE_SIZE;
1118         if (lgp->args.minlength > range->length)
1119                 lgp->args.minlength = range->length;
1120         if (ino) {
1121                 loff_t i_size = i_size_read(ino);
1122
1123                 if (range->iomode == IOMODE_READ) {
1124                         if (range->offset >= i_size)
1125                                 lgp->args.minlength = 0;
1126                         else if (i_size - range->offset < lgp->args.minlength)
1127                                 lgp->args.minlength = i_size - range->offset;
1128                 }
1129         }
1130         lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
1131         pnfs_copy_range(&lgp->args.range, range);
1132         lgp->args.type = server->pnfs_curr_ld->id;
1133         lgp->args.inode = ino;
1134         lgp->args.ctx = get_nfs_open_context(ctx);
1135         nfs4_stateid_copy(&lgp->args.stateid, stateid);
1136         lgp->gfp_flags = gfp_flags;
1137         lgp->cred = ctx->cred;
1138         return lgp;
1139 }
1140
1141 void pnfs_layoutget_free(struct nfs4_layoutget *lgp)
1142 {
1143         size_t max_pages = lgp->args.layout.pglen / PAGE_SIZE;
1144
1145         nfs4_free_pages(lgp->args.layout.pages, max_pages);
1146         pnfs_put_layout_hdr(lgp->lo);
1147         put_nfs_open_context(lgp->args.ctx);
1148         kfree(lgp);
1149 }
1150
1151 static void pnfs_clear_layoutcommit(struct inode *inode,
1152                 struct list_head *head)
1153 {
1154         struct nfs_inode *nfsi = NFS_I(inode);
1155         struct pnfs_layout_segment *lseg, *tmp;
1156
1157         if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
1158                 return;
1159         list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
1160                 if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
1161                         continue;
1162                 pnfs_lseg_dec_and_remove_zero(lseg, head);
1163         }
1164 }
1165
1166 void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
1167                 const nfs4_stateid *arg_stateid,
1168                 const struct pnfs_layout_range *range,
1169                 const nfs4_stateid *stateid)
1170 {
1171         struct inode *inode = lo->plh_inode;
1172         LIST_HEAD(freeme);
1173
1174         spin_lock(&inode->i_lock);
1175         if (!pnfs_layout_is_valid(lo) ||
1176             !nfs4_stateid_match_other(&lo->plh_stateid, arg_stateid))
1177                 goto out_unlock;
1178         if (stateid) {
1179                 u32 seq = be32_to_cpu(arg_stateid->seqid);
1180
1181                 pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
1182                 pnfs_free_returned_lsegs(lo, &freeme, range, seq);
1183                 pnfs_set_layout_stateid(lo, stateid, NULL, true);
1184         } else
1185                 pnfs_mark_layout_stateid_invalid(lo, &freeme);
1186 out_unlock:
1187         pnfs_clear_layoutreturn_waitbit(lo);
1188         spin_unlock(&inode->i_lock);
1189         pnfs_free_lseg_list(&freeme);
1190
1191 }
1192
1193 static bool
1194 pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo,
1195                 nfs4_stateid *stateid,
1196                 const struct cred **cred,
1197                 enum pnfs_iomode *iomode)
1198 {
1199         /* Serialise LAYOUTGET/LAYOUTRETURN */
1200         if (atomic_read(&lo->plh_outstanding) != 0)
1201                 return false;
1202         if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
1203                 return false;
1204         set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
1205         pnfs_get_layout_hdr(lo);
1206         nfs4_stateid_copy(stateid, &lo->plh_stateid);
1207         *cred = get_cred(lo->plh_lc_cred);
1208         if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
1209                 if (lo->plh_return_seq != 0)
1210                         stateid->seqid = cpu_to_be32(lo->plh_return_seq);
1211                 if (iomode != NULL)
1212                         *iomode = lo->plh_return_iomode;
1213                 pnfs_clear_layoutreturn_info(lo);
1214         } else if (iomode != NULL)
1215                 *iomode = IOMODE_ANY;
1216         pnfs_barrier_update(lo, be32_to_cpu(stateid->seqid));
1217         return true;
1218 }
1219
1220 static void
1221 pnfs_init_layoutreturn_args(struct nfs4_layoutreturn_args *args,
1222                 struct pnfs_layout_hdr *lo,
1223                 const nfs4_stateid *stateid,
1224                 enum pnfs_iomode iomode)
1225 {
1226         struct inode *inode = lo->plh_inode;
1227
1228         args->layout_type = NFS_SERVER(inode)->pnfs_curr_ld->id;
1229         args->inode = inode;
1230         args->range.iomode = iomode;
1231         args->range.offset = 0;
1232         args->range.length = NFS4_MAX_UINT64;
1233         args->layout = lo;
1234         nfs4_stateid_copy(&args->stateid, stateid);
1235 }
1236
1237 static int
1238 pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo,
1239                        const nfs4_stateid *stateid,
1240                        const struct cred **pcred,
1241                        enum pnfs_iomode iomode,
1242                        bool sync)
1243 {
1244         struct inode *ino = lo->plh_inode;
1245         struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1246         struct nfs4_layoutreturn *lrp;
1247         const struct cred *cred = *pcred;
1248         int status = 0;
1249
1250         *pcred = NULL;
1251         lrp = kzalloc(sizeof(*lrp), nfs_io_gfp_mask());
1252         if (unlikely(lrp == NULL)) {
1253                 status = -ENOMEM;
1254                 spin_lock(&ino->i_lock);
1255                 pnfs_clear_layoutreturn_waitbit(lo);
1256                 spin_unlock(&ino->i_lock);
1257                 put_cred(cred);
1258                 pnfs_put_layout_hdr(lo);
1259                 goto out;
1260         }
1261
1262         pnfs_init_layoutreturn_args(&lrp->args, lo, stateid, iomode);
1263         lrp->args.ld_private = &lrp->ld_private;
1264         lrp->clp = NFS_SERVER(ino)->nfs_client;
1265         lrp->cred = cred;
1266         if (ld->prepare_layoutreturn)
1267                 ld->prepare_layoutreturn(&lrp->args);
1268
1269         status = nfs4_proc_layoutreturn(lrp, sync);
1270 out:
1271         dprintk("<-- %s status: %d\n", __func__, status);
1272         return status;
1273 }
1274
1275 static bool
1276 pnfs_layout_segments_returnable(struct pnfs_layout_hdr *lo,
1277                                 enum pnfs_iomode iomode,
1278                                 u32 seq)
1279 {
1280         struct pnfs_layout_range recall_range = {
1281                 .length = NFS4_MAX_UINT64,
1282                 .iomode = iomode,
1283         };
1284         return pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs,
1285                                                &recall_range, seq) != -EBUSY;
1286 }
1287
1288 /* Return true if layoutreturn is needed */
1289 static bool
1290 pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
1291 {
1292         if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1293                 return false;
1294         return pnfs_layout_segments_returnable(lo, lo->plh_return_iomode,
1295                                                lo->plh_return_seq);
1296 }
1297
1298 static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
1299 {
1300         struct inode *inode= lo->plh_inode;
1301
1302         if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1303                 return;
1304         spin_lock(&inode->i_lock);
1305         if (pnfs_layout_need_return(lo)) {
1306                 const struct cred *cred;
1307                 nfs4_stateid stateid;
1308                 enum pnfs_iomode iomode;
1309                 bool send;
1310
1311                 send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
1312                 spin_unlock(&inode->i_lock);
1313                 if (send) {
1314                         /* Send an async layoutreturn so we dont deadlock */
1315                         pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
1316                 }
1317         } else
1318                 spin_unlock(&inode->i_lock);
1319 }
1320
1321 /*
1322  * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
1323  * when the layout segment list is empty.
1324  *
1325  * Note that a pnfs_layout_hdr can exist with an empty layout segment
1326  * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
1327  * deviceid is marked invalid.
1328  */
1329 int
1330 _pnfs_return_layout(struct inode *ino)
1331 {
1332         struct pnfs_layout_hdr *lo = NULL;
1333         struct nfs_inode *nfsi = NFS_I(ino);
1334         struct pnfs_layout_range range = {
1335                 .iomode         = IOMODE_ANY,
1336                 .offset         = 0,
1337                 .length         = NFS4_MAX_UINT64,
1338         };
1339         LIST_HEAD(tmp_list);
1340         const struct cred *cred;
1341         nfs4_stateid stateid;
1342         int status = 0;
1343         bool send, valid_layout;
1344
1345         dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
1346
1347         spin_lock(&ino->i_lock);
1348         lo = nfsi->layout;
1349         if (!lo) {
1350                 spin_unlock(&ino->i_lock);
1351                 dprintk("NFS: %s no layout to return\n", __func__);
1352                 goto out;
1353         }
1354         /* Reference matched in nfs4_layoutreturn_release */
1355         pnfs_get_layout_hdr(lo);
1356         /* Is there an outstanding layoutreturn ? */
1357         if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1358                 spin_unlock(&ino->i_lock);
1359                 if (wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1360                                         TASK_UNINTERRUPTIBLE))
1361                         goto out_put_layout_hdr;
1362                 spin_lock(&ino->i_lock);
1363         }
1364         valid_layout = pnfs_layout_is_valid(lo);
1365         pnfs_clear_layoutcommit(ino, &tmp_list);
1366         pnfs_mark_matching_lsegs_return(lo, &tmp_list, &range, 0);
1367
1368         if (NFS_SERVER(ino)->pnfs_curr_ld->return_range)
1369                 NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
1370
1371         /* Don't send a LAYOUTRETURN if list was initially empty */
1372         if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) ||
1373                         !valid_layout) {
1374                 spin_unlock(&ino->i_lock);
1375                 dprintk("NFS: %s no layout segments to return\n", __func__);
1376                 goto out_wait_layoutreturn;
1377         }
1378
1379         send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, NULL);
1380         spin_unlock(&ino->i_lock);
1381         if (send)
1382                 status = pnfs_send_layoutreturn(lo, &stateid, &cred, IOMODE_ANY, true);
1383 out_wait_layoutreturn:
1384         wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN, TASK_UNINTERRUPTIBLE);
1385 out_put_layout_hdr:
1386         pnfs_free_lseg_list(&tmp_list);
1387         pnfs_put_layout_hdr(lo);
1388 out:
1389         dprintk("<-- %s status: %d\n", __func__, status);
1390         return status;
1391 }
1392
1393 int
1394 pnfs_commit_and_return_layout(struct inode *inode)
1395 {
1396         struct pnfs_layout_hdr *lo;
1397         int ret;
1398
1399         spin_lock(&inode->i_lock);
1400         lo = NFS_I(inode)->layout;
1401         if (lo == NULL) {
1402                 spin_unlock(&inode->i_lock);
1403                 return 0;
1404         }
1405         pnfs_get_layout_hdr(lo);
1406         /* Block new layoutgets and read/write to ds */
1407         lo->plh_block_lgets++;
1408         spin_unlock(&inode->i_lock);
1409         filemap_fdatawait(inode->i_mapping);
1410         ret = pnfs_layoutcommit_inode(inode, true);
1411         if (ret == 0)
1412                 ret = _pnfs_return_layout(inode);
1413         spin_lock(&inode->i_lock);
1414         lo->plh_block_lgets--;
1415         spin_unlock(&inode->i_lock);
1416         pnfs_put_layout_hdr(lo);
1417         return ret;
1418 }
1419
1420 bool pnfs_roc(struct inode *ino,
1421                 struct nfs4_layoutreturn_args *args,
1422                 struct nfs4_layoutreturn_res *res,
1423                 const struct cred *cred)
1424 {
1425         struct nfs_inode *nfsi = NFS_I(ino);
1426         struct nfs_open_context *ctx;
1427         struct nfs4_state *state;
1428         struct pnfs_layout_hdr *lo;
1429         struct pnfs_layout_segment *lseg, *next;
1430         const struct cred *lc_cred;
1431         nfs4_stateid stateid;
1432         enum pnfs_iomode iomode = 0;
1433         bool layoutreturn = false, roc = false;
1434         bool skip_read = false;
1435
1436         if (!nfs_have_layout(ino))
1437                 return false;
1438 retry:
1439         rcu_read_lock();
1440         spin_lock(&ino->i_lock);
1441         lo = nfsi->layout;
1442         if (!lo || !pnfs_layout_is_valid(lo) ||
1443             test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1444                 lo = NULL;
1445                 goto out_noroc;
1446         }
1447         pnfs_get_layout_hdr(lo);
1448         if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1449                 spin_unlock(&ino->i_lock);
1450                 rcu_read_unlock();
1451                 wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1452                                 TASK_UNINTERRUPTIBLE);
1453                 pnfs_put_layout_hdr(lo);
1454                 goto retry;
1455         }
1456
1457         /* no roc if we hold a delegation */
1458         if (nfs4_check_delegation(ino, FMODE_READ)) {
1459                 if (nfs4_check_delegation(ino, FMODE_WRITE))
1460                         goto out_noroc;
1461                 skip_read = true;
1462         }
1463
1464         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1465                 state = ctx->state;
1466                 if (state == NULL)
1467                         continue;
1468                 /* Don't return layout if there is open file state */
1469                 if (state->state & FMODE_WRITE)
1470                         goto out_noroc;
1471                 if (state->state & FMODE_READ)
1472                         skip_read = true;
1473         }
1474
1475
1476         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) {
1477                 if (skip_read && lseg->pls_range.iomode == IOMODE_READ)
1478                         continue;
1479                 /* If we are sending layoutreturn, invalidate all valid lsegs */
1480                 if (!test_and_clear_bit(NFS_LSEG_ROC, &lseg->pls_flags))
1481                         continue;
1482                 /*
1483                  * Note: mark lseg for return so pnfs_layout_remove_lseg
1484                  * doesn't invalidate the layout for us.
1485                  */
1486                 set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1487                 if (!mark_lseg_invalid(lseg, &lo->plh_return_segs))
1488                         continue;
1489                 pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
1490         }
1491
1492         if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1493                 goto out_noroc;
1494
1495         /* ROC in two conditions:
1496          * 1. there are ROC lsegs
1497          * 2. we don't send layoutreturn
1498          */
1499         /* lo ref dropped in pnfs_roc_release() */
1500         layoutreturn = pnfs_prepare_layoutreturn(lo, &stateid, &lc_cred, &iomode);
1501         /* If the creds don't match, we can't compound the layoutreturn */
1502         if (!layoutreturn || cred_fscmp(cred, lc_cred) != 0)
1503                 goto out_noroc;
1504
1505         roc = layoutreturn;
1506         pnfs_init_layoutreturn_args(args, lo, &stateid, iomode);
1507         res->lrs_present = 0;
1508         layoutreturn = false;
1509         put_cred(lc_cred);
1510
1511 out_noroc:
1512         spin_unlock(&ino->i_lock);
1513         rcu_read_unlock();
1514         pnfs_layoutcommit_inode(ino, true);
1515         if (roc) {
1516                 struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1517                 if (ld->prepare_layoutreturn)
1518                         ld->prepare_layoutreturn(args);
1519                 pnfs_put_layout_hdr(lo);
1520                 return true;
1521         }
1522         if (layoutreturn)
1523                 pnfs_send_layoutreturn(lo, &stateid, &lc_cred, iomode, true);
1524         pnfs_put_layout_hdr(lo);
1525         return false;
1526 }
1527
1528 int pnfs_roc_done(struct rpc_task *task, struct nfs4_layoutreturn_args **argpp,
1529                   struct nfs4_layoutreturn_res **respp, int *ret)
1530 {
1531         struct nfs4_layoutreturn_args *arg = *argpp;
1532         int retval = -EAGAIN;
1533
1534         if (!arg)
1535                 return 0;
1536         /* Handle Layoutreturn errors */
1537         switch (*ret) {
1538         case 0:
1539                 retval = 0;
1540                 break;
1541         case -NFS4ERR_NOMATCHING_LAYOUT:
1542                 /* Was there an RPC level error? If not, retry */
1543                 if (task->tk_rpc_status == 0)
1544                         break;
1545                 /* If the call was not sent, let caller handle it */
1546                 if (!RPC_WAS_SENT(task))
1547                         return 0;
1548                 /*
1549                  * Otherwise, assume the call succeeded and
1550                  * that we need to release the layout
1551                  */
1552                 *ret = 0;
1553                 (*respp)->lrs_present = 0;
1554                 retval = 0;
1555                 break;
1556         case -NFS4ERR_DELAY:
1557                 /* Let the caller handle the retry */
1558                 *ret = -NFS4ERR_NOMATCHING_LAYOUT;
1559                 return 0;
1560         case -NFS4ERR_OLD_STATEID:
1561                 if (!nfs4_layout_refresh_old_stateid(&arg->stateid,
1562                                                      &arg->range, arg->inode))
1563                         break;
1564                 *ret = -NFS4ERR_NOMATCHING_LAYOUT;
1565                 return -EAGAIN;
1566         }
1567         *argpp = NULL;
1568         *respp = NULL;
1569         return retval;
1570 }
1571
1572 void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
1573                 struct nfs4_layoutreturn_res *res,
1574                 int ret)
1575 {
1576         struct pnfs_layout_hdr *lo = args->layout;
1577         struct inode *inode = args->inode;
1578         const nfs4_stateid *res_stateid = NULL;
1579         struct nfs4_xdr_opaque_data *ld_private = args->ld_private;
1580
1581         switch (ret) {
1582         case -NFS4ERR_NOMATCHING_LAYOUT:
1583                 spin_lock(&inode->i_lock);
1584                 if (pnfs_layout_is_valid(lo) &&
1585                     nfs4_stateid_match_other(&args->stateid, &lo->plh_stateid))
1586                         pnfs_set_plh_return_info(lo, args->range.iomode, 0);
1587                 pnfs_clear_layoutreturn_waitbit(lo);
1588                 spin_unlock(&inode->i_lock);
1589                 break;
1590         case 0:
1591                 if (res->lrs_present)
1592                         res_stateid = &res->stateid;
1593                 fallthrough;
1594         default:
1595                 pnfs_layoutreturn_free_lsegs(lo, &args->stateid, &args->range,
1596                                              res_stateid);
1597         }
1598         trace_nfs4_layoutreturn_on_close(args->inode, &args->stateid, ret);
1599         if (ld_private && ld_private->ops && ld_private->ops->free)
1600                 ld_private->ops->free(ld_private);
1601         pnfs_put_layout_hdr(lo);
1602 }
1603
1604 bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
1605 {
1606         struct nfs_inode *nfsi = NFS_I(ino);
1607         struct pnfs_layout_hdr *lo;
1608         bool sleep = false;
1609
1610         /* we might not have grabbed lo reference. so need to check under
1611          * i_lock */
1612         spin_lock(&ino->i_lock);
1613         lo = nfsi->layout;
1614         if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1615                 rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
1616                 sleep = true;
1617         }
1618         spin_unlock(&ino->i_lock);
1619         return sleep;
1620 }
1621
1622 /*
1623  * Compare two layout segments for sorting into layout cache.
1624  * We want to preferentially return RW over RO layouts, so ensure those
1625  * are seen first.
1626  */
1627 static s64
1628 pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1629            const struct pnfs_layout_range *l2)
1630 {
1631         s64 d;
1632
1633         /* high offset > low offset */
1634         d = l1->offset - l2->offset;
1635         if (d)
1636                 return d;
1637
1638         /* short length > long length */
1639         d = l2->length - l1->length;
1640         if (d)
1641                 return d;
1642
1643         /* read > read/write */
1644         return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1645 }
1646
1647 static bool
1648 pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1649                 const struct pnfs_layout_range *l2)
1650 {
1651         return pnfs_lseg_range_cmp(l1, l2) > 0;
1652 }
1653
1654 static bool
1655 pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1656                 struct pnfs_layout_segment *old)
1657 {
1658         return false;
1659 }
1660
1661 void
1662 pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1663                    struct pnfs_layout_segment *lseg,
1664                    bool (*is_after)(const struct pnfs_layout_range *,
1665                            const struct pnfs_layout_range *),
1666                    bool (*do_merge)(struct pnfs_layout_segment *,
1667                            struct pnfs_layout_segment *),
1668                    struct list_head *free_me)
1669 {
1670         struct pnfs_layout_segment *lp, *tmp;
1671
1672         dprintk("%s:Begin\n", __func__);
1673
1674         list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1675                 if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1676                         continue;
1677                 if (do_merge(lseg, lp)) {
1678                         mark_lseg_invalid(lp, free_me);
1679                         continue;
1680                 }
1681                 if (is_after(&lseg->pls_range, &lp->pls_range))
1682                         continue;
1683                 list_add_tail(&lseg->pls_list, &lp->pls_list);
1684                 dprintk("%s: inserted lseg %p "
1685                         "iomode %d offset %llu length %llu before "
1686                         "lp %p iomode %d offset %llu length %llu\n",
1687                         __func__, lseg, lseg->pls_range.iomode,
1688                         lseg->pls_range.offset, lseg->pls_range.length,
1689                         lp, lp->pls_range.iomode, lp->pls_range.offset,
1690                         lp->pls_range.length);
1691                 goto out;
1692         }
1693         list_add_tail(&lseg->pls_list, &lo->plh_segs);
1694         dprintk("%s: inserted lseg %p "
1695                 "iomode %d offset %llu length %llu at tail\n",
1696                 __func__, lseg, lseg->pls_range.iomode,
1697                 lseg->pls_range.offset, lseg->pls_range.length);
1698 out:
1699         pnfs_get_layout_hdr(lo);
1700
1701         dprintk("%s:Return\n", __func__);
1702 }
1703 EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1704
1705 static void
1706 pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1707                    struct pnfs_layout_segment *lseg,
1708                    struct list_head *free_me)
1709 {
1710         struct inode *inode = lo->plh_inode;
1711         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1712
1713         if (ld->add_lseg != NULL)
1714                 ld->add_lseg(lo, lseg, free_me);
1715         else
1716                 pnfs_generic_layout_insert_lseg(lo, lseg,
1717                                 pnfs_lseg_range_is_after,
1718                                 pnfs_lseg_no_merge,
1719                                 free_me);
1720 }
1721
1722 static struct pnfs_layout_hdr *
1723 alloc_init_layout_hdr(struct inode *ino,
1724                       struct nfs_open_context *ctx,
1725                       gfp_t gfp_flags)
1726 {
1727         struct pnfs_layout_hdr *lo;
1728
1729         lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1730         if (!lo)
1731                 return NULL;
1732         refcount_set(&lo->plh_refcount, 1);
1733         INIT_LIST_HEAD(&lo->plh_layouts);
1734         INIT_LIST_HEAD(&lo->plh_segs);
1735         INIT_LIST_HEAD(&lo->plh_return_segs);
1736         INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1737         lo->plh_inode = ino;
1738         lo->plh_lc_cred = get_cred(ctx->cred);
1739         lo->plh_flags |= 1 << NFS_LAYOUT_INVALID_STID;
1740         return lo;
1741 }
1742
1743 static struct pnfs_layout_hdr *
1744 pnfs_find_alloc_layout(struct inode *ino,
1745                        struct nfs_open_context *ctx,
1746                        gfp_t gfp_flags)
1747         __releases(&ino->i_lock)
1748         __acquires(&ino->i_lock)
1749 {
1750         struct nfs_inode *nfsi = NFS_I(ino);
1751         struct pnfs_layout_hdr *new = NULL;
1752
1753         dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1754
1755         if (nfsi->layout != NULL)
1756                 goto out_existing;
1757         spin_unlock(&ino->i_lock);
1758         new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1759         spin_lock(&ino->i_lock);
1760
1761         if (likely(nfsi->layout == NULL)) {     /* Won the race? */
1762                 nfsi->layout = new;
1763                 return new;
1764         } else if (new != NULL)
1765                 pnfs_free_layout_hdr(new);
1766 out_existing:
1767         pnfs_get_layout_hdr(nfsi->layout);
1768         return nfsi->layout;
1769 }
1770
1771 /*
1772  * iomode matching rules:
1773  * iomode       lseg    strict match
1774  *                      iomode
1775  * -----        -----   ------ -----
1776  * ANY          READ    N/A    true
1777  * ANY          RW      N/A    true
1778  * RW           READ    N/A    false
1779  * RW           RW      N/A    true
1780  * READ         READ    N/A    true
1781  * READ         RW      true   false
1782  * READ         RW      false  true
1783  */
1784 static bool
1785 pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1786                  const struct pnfs_layout_range *range,
1787                  bool strict_iomode)
1788 {
1789         struct pnfs_layout_range range1;
1790
1791         if ((range->iomode == IOMODE_RW &&
1792              ls_range->iomode != IOMODE_RW) ||
1793             (range->iomode != ls_range->iomode &&
1794              strict_iomode) ||
1795             !pnfs_lseg_range_intersecting(ls_range, range))
1796                 return false;
1797
1798         /* range1 covers only the first byte in the range */
1799         range1 = *range;
1800         range1.length = 1;
1801         return pnfs_lseg_range_contained(ls_range, &range1);
1802 }
1803
1804 /*
1805  * lookup range in layout
1806  */
1807 static struct pnfs_layout_segment *
1808 pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1809                 struct pnfs_layout_range *range,
1810                 bool strict_iomode)
1811 {
1812         struct pnfs_layout_segment *lseg, *ret = NULL;
1813
1814         dprintk("%s:Begin\n", __func__);
1815
1816         list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1817                 if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1818                     pnfs_lseg_range_match(&lseg->pls_range, range,
1819                                           strict_iomode)) {
1820                         ret = pnfs_get_lseg(lseg);
1821                         break;
1822                 }
1823         }
1824
1825         dprintk("%s:Return lseg %p ref %d\n",
1826                 __func__, ret, ret ? refcount_read(&ret->pls_refcount) : 0);
1827         return ret;
1828 }
1829
1830 /*
1831  * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1832  * to the MDS or over pNFS
1833  *
1834  * The nfs_inode read_io and write_io fields are cumulative counters reset
1835  * when there are no layout segments. Note that in pnfs_update_layout iomode
1836  * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1837  * WRITE request.
1838  *
1839  * A return of true means use MDS I/O.
1840  *
1841  * From rfc 5661:
1842  * If a file's size is smaller than the file size threshold, data accesses
1843  * SHOULD be sent to the metadata server.  If an I/O request has a length that
1844  * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1845  * server.  If both file size and I/O size are provided, the client SHOULD
1846  * reach or exceed  both thresholds before sending its read or write
1847  * requests to the data server.
1848  */
1849 static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1850                                      struct inode *ino, int iomode)
1851 {
1852         struct nfs4_threshold *t = ctx->mdsthreshold;
1853         struct nfs_inode *nfsi = NFS_I(ino);
1854         loff_t fsize = i_size_read(ino);
1855         bool size = false, size_set = false, io = false, io_set = false, ret = false;
1856
1857         if (t == NULL)
1858                 return ret;
1859
1860         dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1861                 __func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1862
1863         switch (iomode) {
1864         case IOMODE_READ:
1865                 if (t->bm & THRESHOLD_RD) {
1866                         dprintk("%s fsize %llu\n", __func__, fsize);
1867                         size_set = true;
1868                         if (fsize < t->rd_sz)
1869                                 size = true;
1870                 }
1871                 if (t->bm & THRESHOLD_RD_IO) {
1872                         dprintk("%s nfsi->read_io %llu\n", __func__,
1873                                 nfsi->read_io);
1874                         io_set = true;
1875                         if (nfsi->read_io < t->rd_io_sz)
1876                                 io = true;
1877                 }
1878                 break;
1879         case IOMODE_RW:
1880                 if (t->bm & THRESHOLD_WR) {
1881                         dprintk("%s fsize %llu\n", __func__, fsize);
1882                         size_set = true;
1883                         if (fsize < t->wr_sz)
1884                                 size = true;
1885                 }
1886                 if (t->bm & THRESHOLD_WR_IO) {
1887                         dprintk("%s nfsi->write_io %llu\n", __func__,
1888                                 nfsi->write_io);
1889                         io_set = true;
1890                         if (nfsi->write_io < t->wr_io_sz)
1891                                 io = true;
1892                 }
1893                 break;
1894         }
1895         if (size_set && io_set) {
1896                 if (size && io)
1897                         ret = true;
1898         } else if (size || io)
1899                 ret = true;
1900
1901         dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1902         return ret;
1903 }
1904
1905 static int pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
1906 {
1907         /*
1908          * send layoutcommit as it can hold up layoutreturn due to lseg
1909          * reference
1910          */
1911         pnfs_layoutcommit_inode(lo->plh_inode, false);
1912         return wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
1913                                    nfs_wait_bit_killable,
1914                                    TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
1915 }
1916
1917 static void nfs_layoutget_begin(struct pnfs_layout_hdr *lo)
1918 {
1919         atomic_inc(&lo->plh_outstanding);
1920 }
1921
1922 static void nfs_layoutget_end(struct pnfs_layout_hdr *lo)
1923 {
1924         if (atomic_dec_and_test(&lo->plh_outstanding) &&
1925             test_and_clear_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags))
1926                 wake_up_bit(&lo->plh_flags, NFS_LAYOUT_DRAIN);
1927 }
1928
1929 static bool pnfs_is_first_layoutget(struct pnfs_layout_hdr *lo)
1930 {
1931         return test_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags);
1932 }
1933
1934 static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
1935 {
1936         unsigned long *bitlock = &lo->plh_flags;
1937
1938         clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
1939         smp_mb__after_atomic();
1940         wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
1941 }
1942
1943 static void _add_to_server_list(struct pnfs_layout_hdr *lo,
1944                                 struct nfs_server *server)
1945 {
1946         if (!test_and_set_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
1947                 struct nfs_client *clp = server->nfs_client;
1948
1949                 /* The lo must be on the clp list if there is any
1950                  * chance of a CB_LAYOUTRECALL(FILE) coming in.
1951                  */
1952                 spin_lock(&clp->cl_lock);
1953                 list_add_tail_rcu(&lo->plh_layouts, &server->layouts);
1954                 spin_unlock(&clp->cl_lock);
1955         }
1956 }
1957
1958 /*
1959  * Layout segment is retreived from the server if not cached.
1960  * The appropriate layout segment is referenced and returned to the caller.
1961  */
1962 struct pnfs_layout_segment *
1963 pnfs_update_layout(struct inode *ino,
1964                    struct nfs_open_context *ctx,
1965                    loff_t pos,
1966                    u64 count,
1967                    enum pnfs_iomode iomode,
1968                    bool strict_iomode,
1969                    gfp_t gfp_flags)
1970 {
1971         struct pnfs_layout_range arg = {
1972                 .iomode = iomode,
1973                 .offset = pos,
1974                 .length = count,
1975         };
1976         unsigned pg_offset;
1977         struct nfs_server *server = NFS_SERVER(ino);
1978         struct nfs_client *clp = server->nfs_client;
1979         struct pnfs_layout_hdr *lo = NULL;
1980         struct pnfs_layout_segment *lseg = NULL;
1981         struct nfs4_layoutget *lgp;
1982         nfs4_stateid stateid;
1983         long timeout = 0;
1984         unsigned long giveup = jiffies + (clp->cl_lease_time << 1);
1985         bool first;
1986
1987         if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
1988                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1989                                  PNFS_UPDATE_LAYOUT_NO_PNFS);
1990                 goto out;
1991         }
1992
1993         if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
1994                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1995                                  PNFS_UPDATE_LAYOUT_MDSTHRESH);
1996                 goto out;
1997         }
1998
1999 lookup_again:
2000         lseg = ERR_PTR(nfs4_client_recover_expired_lease(clp));
2001         if (IS_ERR(lseg))
2002                 goto out;
2003         first = false;
2004         spin_lock(&ino->i_lock);
2005         lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
2006         if (lo == NULL) {
2007                 spin_unlock(&ino->i_lock);
2008                 lseg = ERR_PTR(-ENOMEM);
2009                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2010                                  PNFS_UPDATE_LAYOUT_NOMEM);
2011                 goto out;
2012         }
2013
2014         /* Do we even need to bother with this? */
2015         if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
2016                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2017                                  PNFS_UPDATE_LAYOUT_BULK_RECALL);
2018                 dprintk("%s matches recall, use MDS\n", __func__);
2019                 goto out_unlock;
2020         }
2021
2022         /* if LAYOUTGET already failed once we don't try again */
2023         if (pnfs_layout_io_test_failed(lo, iomode)) {
2024                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2025                                  PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
2026                 goto out_unlock;
2027         }
2028
2029         /*
2030          * If the layout segment list is empty, but there are outstanding
2031          * layoutget calls, then they might be subject to a layoutrecall.
2032          */
2033         if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags) &&
2034             atomic_read(&lo->plh_outstanding) != 0) {
2035                 spin_unlock(&ino->i_lock);
2036                 lseg = ERR_PTR(wait_on_bit(&lo->plh_flags, NFS_LAYOUT_DRAIN,
2037                                            TASK_KILLABLE));
2038                 if (IS_ERR(lseg))
2039                         goto out_put_layout_hdr;
2040                 pnfs_put_layout_hdr(lo);
2041                 goto lookup_again;
2042         }
2043
2044         /*
2045          * Because we free lsegs when sending LAYOUTRETURN, we need to wait
2046          * for LAYOUTRETURN.
2047          */
2048         if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
2049                 spin_unlock(&ino->i_lock);
2050                 dprintk("%s wait for layoutreturn\n", __func__);
2051                 lseg = ERR_PTR(pnfs_prepare_to_retry_layoutget(lo));
2052                 if (!IS_ERR(lseg)) {
2053                         pnfs_put_layout_hdr(lo);
2054                         dprintk("%s retrying\n", __func__);
2055                         trace_pnfs_update_layout(ino, pos, count, iomode, lo,
2056                                                  lseg,
2057                                                  PNFS_UPDATE_LAYOUT_RETRY);
2058                         goto lookup_again;
2059                 }
2060                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2061                                          PNFS_UPDATE_LAYOUT_RETURN);
2062                 goto out_put_layout_hdr;
2063         }
2064
2065         lseg = pnfs_find_lseg(lo, &arg, strict_iomode);
2066         if (lseg) {
2067                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2068                                 PNFS_UPDATE_LAYOUT_FOUND_CACHED);
2069                 goto out_unlock;
2070         }
2071
2072         /*
2073          * Choose a stateid for the LAYOUTGET. If we don't have a layout
2074          * stateid, or it has been invalidated, then we must use the open
2075          * stateid.
2076          */
2077         if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
2078                 int status;
2079
2080                 /*
2081                  * The first layoutget for the file. Need to serialize per
2082                  * RFC 5661 Errata 3208.
2083                  */
2084                 if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
2085                                      &lo->plh_flags)) {
2086                         spin_unlock(&ino->i_lock);
2087                         lseg = ERR_PTR(wait_on_bit(&lo->plh_flags,
2088                                                 NFS_LAYOUT_FIRST_LAYOUTGET,
2089                                                 TASK_KILLABLE));
2090                         if (IS_ERR(lseg))
2091                                 goto out_put_layout_hdr;
2092                         pnfs_put_layout_hdr(lo);
2093                         dprintk("%s retrying\n", __func__);
2094                         goto lookup_again;
2095                 }
2096
2097                 spin_unlock(&ino->i_lock);
2098                 first = true;
2099                 status = nfs4_select_rw_stateid(ctx->state,
2100                                         iomode == IOMODE_RW ? FMODE_WRITE : FMODE_READ,
2101                                         NULL, &stateid, NULL);
2102                 if (status != 0) {
2103                         lseg = ERR_PTR(status);
2104                         trace_pnfs_update_layout(ino, pos, count,
2105                                         iomode, lo, lseg,
2106                                         PNFS_UPDATE_LAYOUT_INVALID_OPEN);
2107                         nfs4_schedule_stateid_recovery(server, ctx->state);
2108                         pnfs_clear_first_layoutget(lo);
2109                         pnfs_put_layout_hdr(lo);
2110                         goto lookup_again;
2111                 }
2112                 spin_lock(&ino->i_lock);
2113         } else {
2114                 nfs4_stateid_copy(&stateid, &lo->plh_stateid);
2115         }
2116
2117         if (pnfs_layoutgets_blocked(lo)) {
2118                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2119                                 PNFS_UPDATE_LAYOUT_BLOCKED);
2120                 goto out_unlock;
2121         }
2122         nfs_layoutget_begin(lo);
2123         spin_unlock(&ino->i_lock);
2124
2125         _add_to_server_list(lo, server);
2126
2127         pg_offset = arg.offset & ~PAGE_MASK;
2128         if (pg_offset) {
2129                 arg.offset -= pg_offset;
2130                 arg.length += pg_offset;
2131         }
2132         if (arg.length != NFS4_MAX_UINT64)
2133                 arg.length = PAGE_ALIGN(arg.length);
2134
2135         lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &stateid, &arg, gfp_flags);
2136         if (!lgp) {
2137                 lseg = ERR_PTR(-ENOMEM);
2138                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, NULL,
2139                                          PNFS_UPDATE_LAYOUT_NOMEM);
2140                 nfs_layoutget_end(lo);
2141                 goto out_put_layout_hdr;
2142         }
2143
2144         lgp->lo = lo;
2145         pnfs_get_layout_hdr(lo);
2146
2147         lseg = nfs4_proc_layoutget(lgp, &timeout);
2148         trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2149                                  PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
2150         nfs_layoutget_end(lo);
2151         if (IS_ERR(lseg)) {
2152                 switch(PTR_ERR(lseg)) {
2153                 case -EBUSY:
2154                         if (time_after(jiffies, giveup))
2155                                 lseg = NULL;
2156                         break;
2157                 case -ERECALLCONFLICT:
2158                 case -EAGAIN:
2159                         break;
2160                 case -ENODATA:
2161                         /* The server returned NFS4ERR_LAYOUTUNAVAILABLE */
2162                         pnfs_layout_set_fail_bit(
2163                                 lo, pnfs_iomode_to_fail_bit(iomode));
2164                         lseg = NULL;
2165                         goto out_put_layout_hdr;
2166                 default:
2167                         if (!nfs_error_is_fatal(PTR_ERR(lseg))) {
2168                                 pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2169                                 lseg = NULL;
2170                         }
2171                         goto out_put_layout_hdr;
2172                 }
2173                 if (lseg) {
2174                         if (first)
2175                                 pnfs_clear_first_layoutget(lo);
2176                         trace_pnfs_update_layout(ino, pos, count,
2177                                 iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
2178                         pnfs_put_layout_hdr(lo);
2179                         goto lookup_again;
2180                 }
2181         } else {
2182                 pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2183         }
2184
2185 out_put_layout_hdr:
2186         if (first)
2187                 pnfs_clear_first_layoutget(lo);
2188         trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2189                                  PNFS_UPDATE_LAYOUT_EXIT);
2190         pnfs_put_layout_hdr(lo);
2191 out:
2192         dprintk("%s: inode %s/%llu pNFS layout segment %s for "
2193                         "(%s, offset: %llu, length: %llu)\n",
2194                         __func__, ino->i_sb->s_id,
2195                         (unsigned long long)NFS_FILEID(ino),
2196                         IS_ERR_OR_NULL(lseg) ? "not found" : "found",
2197                         iomode==IOMODE_RW ?  "read/write" : "read-only",
2198                         (unsigned long long)pos,
2199                         (unsigned long long)count);
2200         return lseg;
2201 out_unlock:
2202         spin_unlock(&ino->i_lock);
2203         goto out_put_layout_hdr;
2204 }
2205 EXPORT_SYMBOL_GPL(pnfs_update_layout);
2206
2207 static bool
2208 pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
2209 {
2210         switch (range->iomode) {
2211         case IOMODE_READ:
2212         case IOMODE_RW:
2213                 break;
2214         default:
2215                 return false;
2216         }
2217         if (range->offset == NFS4_MAX_UINT64)
2218                 return false;
2219         if (range->length == 0)
2220                 return false;
2221         if (range->length != NFS4_MAX_UINT64 &&
2222             range->length > NFS4_MAX_UINT64 - range->offset)
2223                 return false;
2224         return true;
2225 }
2226
2227 static struct pnfs_layout_hdr *
2228 _pnfs_grab_empty_layout(struct inode *ino, struct nfs_open_context *ctx)
2229 {
2230         struct pnfs_layout_hdr *lo;
2231
2232         spin_lock(&ino->i_lock);
2233         lo = pnfs_find_alloc_layout(ino, ctx, nfs_io_gfp_mask());
2234         if (!lo)
2235                 goto out_unlock;
2236         if (!test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
2237                 goto out_unlock;
2238         if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
2239                 goto out_unlock;
2240         if (pnfs_layoutgets_blocked(lo))
2241                 goto out_unlock;
2242         if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags))
2243                 goto out_unlock;
2244         nfs_layoutget_begin(lo);
2245         spin_unlock(&ino->i_lock);
2246         _add_to_server_list(lo, NFS_SERVER(ino));
2247         return lo;
2248
2249 out_unlock:
2250         spin_unlock(&ino->i_lock);
2251         pnfs_put_layout_hdr(lo);
2252         return NULL;
2253 }
2254
2255 static void _lgopen_prepare_attached(struct nfs4_opendata *data,
2256                                      struct nfs_open_context *ctx)
2257 {
2258         struct inode *ino = data->dentry->d_inode;
2259         struct pnfs_layout_range rng = {
2260                 .iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2261                           IOMODE_RW: IOMODE_READ,
2262                 .offset = 0,
2263                 .length = NFS4_MAX_UINT64,
2264         };
2265         struct nfs4_layoutget *lgp;
2266         struct pnfs_layout_hdr *lo;
2267
2268         /* Heuristic: don't send layoutget if we have cached data */
2269         if (rng.iomode == IOMODE_READ &&
2270            (i_size_read(ino) == 0 || ino->i_mapping->nrpages != 0))
2271                 return;
2272
2273         lo = _pnfs_grab_empty_layout(ino, ctx);
2274         if (!lo)
2275                 return;
2276         lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid, &rng,
2277                                              nfs_io_gfp_mask());
2278         if (!lgp) {
2279                 pnfs_clear_first_layoutget(lo);
2280                 nfs_layoutget_end(lo);
2281                 pnfs_put_layout_hdr(lo);
2282                 return;
2283         }
2284         lgp->lo = lo;
2285         data->lgp = lgp;
2286         data->o_arg.lg_args = &lgp->args;
2287         data->o_res.lg_res = &lgp->res;
2288 }
2289
2290 static void _lgopen_prepare_floating(struct nfs4_opendata *data,
2291                                      struct nfs_open_context *ctx)
2292 {
2293         struct inode *ino = data->dentry->d_inode;
2294         struct pnfs_layout_range rng = {
2295                 .iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2296                           IOMODE_RW: IOMODE_READ,
2297                 .offset = 0,
2298                 .length = NFS4_MAX_UINT64,
2299         };
2300         struct nfs4_layoutget *lgp;
2301
2302         lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid, &rng,
2303                                              nfs_io_gfp_mask());
2304         if (!lgp)
2305                 return;
2306         data->lgp = lgp;
2307         data->o_arg.lg_args = &lgp->args;
2308         data->o_res.lg_res = &lgp->res;
2309 }
2310
2311 void pnfs_lgopen_prepare(struct nfs4_opendata *data,
2312                          struct nfs_open_context *ctx)
2313 {
2314         struct nfs_server *server = NFS_SERVER(data->dir->d_inode);
2315
2316         if (!(pnfs_enabled_sb(server) &&
2317               server->pnfs_curr_ld->flags & PNFS_LAYOUTGET_ON_OPEN))
2318                 return;
2319         /* Could check on max_ops, but currently hardcoded high enough */
2320         if (!nfs_server_capable(data->dir->d_inode, NFS_CAP_LGOPEN))
2321                 return;
2322         if (data->lgp)
2323                 return;
2324         if (data->state)
2325                 _lgopen_prepare_attached(data, ctx);
2326         else
2327                 _lgopen_prepare_floating(data, ctx);
2328 }
2329
2330 void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
2331                        struct nfs_open_context *ctx)
2332 {
2333         struct pnfs_layout_hdr *lo;
2334         struct pnfs_layout_segment *lseg;
2335         struct nfs_server *srv = NFS_SERVER(ino);
2336         u32 iomode;
2337
2338         if (!lgp)
2339                 return;
2340         dprintk("%s: entered with status %i\n", __func__, lgp->res.status);
2341         if (lgp->res.status) {
2342                 switch (lgp->res.status) {
2343                 default:
2344                         break;
2345                 /*
2346                  * Halt lgopen attempts if the server doesn't recognise
2347                  * the "current stateid" value, the layout type, or the
2348                  * layoutget operation as being valid.
2349                  * Also if it complains about too many ops in the compound
2350                  * or of the request/reply being too big.
2351                  */
2352                 case -NFS4ERR_BAD_STATEID:
2353                 case -NFS4ERR_NOTSUPP:
2354                 case -NFS4ERR_REP_TOO_BIG:
2355                 case -NFS4ERR_REP_TOO_BIG_TO_CACHE:
2356                 case -NFS4ERR_REQ_TOO_BIG:
2357                 case -NFS4ERR_TOO_MANY_OPS:
2358                 case -NFS4ERR_UNKNOWN_LAYOUTTYPE:
2359                         srv->caps &= ~NFS_CAP_LGOPEN;
2360                 }
2361                 return;
2362         }
2363         if (!lgp->lo) {
2364                 lo = _pnfs_grab_empty_layout(ino, ctx);
2365                 if (!lo)
2366                         return;
2367                 lgp->lo = lo;
2368         } else
2369                 lo = lgp->lo;
2370
2371         lseg = pnfs_layout_process(lgp);
2372         if (!IS_ERR(lseg)) {
2373                 iomode = lgp->args.range.iomode;
2374                 pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2375                 pnfs_put_lseg(lseg);
2376         }
2377 }
2378
2379 void nfs4_lgopen_release(struct nfs4_layoutget *lgp)
2380 {
2381         if (lgp != NULL) {
2382                 if (lgp->lo) {
2383                         pnfs_clear_first_layoutget(lgp->lo);
2384                         nfs_layoutget_end(lgp->lo);
2385                 }
2386                 pnfs_layoutget_free(lgp);
2387         }
2388 }
2389
2390 struct pnfs_layout_segment *
2391 pnfs_layout_process(struct nfs4_layoutget *lgp)
2392 {
2393         struct pnfs_layout_hdr *lo = lgp->lo;
2394         struct nfs4_layoutget_res *res = &lgp->res;
2395         struct pnfs_layout_segment *lseg;
2396         struct inode *ino = lo->plh_inode;
2397         LIST_HEAD(free_me);
2398
2399         if (!pnfs_sanity_check_layout_range(&res->range))
2400                 return ERR_PTR(-EINVAL);
2401
2402         /* Inject layout blob into I/O device driver */
2403         lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
2404         if (IS_ERR_OR_NULL(lseg)) {
2405                 if (!lseg)
2406                         lseg = ERR_PTR(-ENOMEM);
2407
2408                 dprintk("%s: Could not allocate layout: error %ld\n",
2409                        __func__, PTR_ERR(lseg));
2410                 return lseg;
2411         }
2412
2413         pnfs_init_lseg(lo, lseg, &res->range, &res->stateid);
2414
2415         spin_lock(&ino->i_lock);
2416         if (pnfs_layoutgets_blocked(lo)) {
2417                 dprintk("%s forget reply due to state\n", __func__);
2418                 goto out_forget;
2419         }
2420
2421         if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags) &&
2422             !pnfs_is_first_layoutget(lo))
2423                 goto out_forget;
2424
2425         if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
2426                 /* existing state ID, make sure the sequence number matches. */
2427                 if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
2428                         if (!pnfs_layout_is_valid(lo))
2429                                 lo->plh_barrier = 0;
2430                         dprintk("%s forget reply due to sequence\n", __func__);
2431                         goto out_forget;
2432                 }
2433                 pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, false);
2434         } else if (pnfs_layout_is_valid(lo)) {
2435                 /*
2436                  * We got an entirely new state ID.  Mark all segments for the
2437                  * inode invalid, and retry the layoutget
2438                  */
2439                 struct pnfs_layout_range range = {
2440                         .iomode = IOMODE_ANY,
2441                         .length = NFS4_MAX_UINT64,
2442                 };
2443                 pnfs_mark_matching_lsegs_return(lo, &free_me, &range, 0);
2444                 goto out_forget;
2445         } else {
2446                 /* We have a completely new layout */
2447                 pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, true);
2448         }
2449
2450         pnfs_get_lseg(lseg);
2451         pnfs_layout_insert_lseg(lo, lseg, &free_me);
2452
2453
2454         if (res->return_on_close)
2455                 set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
2456
2457         spin_unlock(&ino->i_lock);
2458         pnfs_free_lseg_list(&free_me);
2459         return lseg;
2460
2461 out_forget:
2462         spin_unlock(&ino->i_lock);
2463         lseg->pls_layout = lo;
2464         NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
2465         return ERR_PTR(-EAGAIN);
2466 }
2467
2468 /**
2469  * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
2470  * @lo: pointer to layout header
2471  * @tmp_list: list header to be used with pnfs_free_lseg_list()
2472  * @return_range: describe layout segment ranges to be returned
2473  * @seq: stateid seqid to match
2474  *
2475  * This function is mainly intended for use by layoutrecall. It attempts
2476  * to free the layout segment immediately, or else to mark it for return
2477  * as soon as its reference count drops to zero.
2478  *
2479  * Returns
2480  * - 0: a layoutreturn needs to be scheduled.
2481  * - EBUSY: there are layout segment that are still in use.
2482  * - ENOENT: there are no layout segments that need to be returned.
2483  */
2484 int
2485 pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
2486                                 struct list_head *tmp_list,
2487                                 const struct pnfs_layout_range *return_range,
2488                                 u32 seq)
2489 {
2490         struct pnfs_layout_segment *lseg, *next;
2491         struct nfs_server *server = NFS_SERVER(lo->plh_inode);
2492         int remaining = 0;
2493
2494         dprintk("%s:Begin lo %p\n", __func__, lo);
2495
2496         assert_spin_locked(&lo->plh_inode->i_lock);
2497
2498         if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
2499                 tmp_list = &lo->plh_return_segs;
2500
2501         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
2502                 if (pnfs_match_lseg_recall(lseg, return_range, seq)) {
2503                         dprintk("%s: marking lseg %p iomode %d "
2504                                 "offset %llu length %llu\n", __func__,
2505                                 lseg, lseg->pls_range.iomode,
2506                                 lseg->pls_range.offset,
2507                                 lseg->pls_range.length);
2508                         if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
2509                                 tmp_list = &lo->plh_return_segs;
2510                         if (mark_lseg_invalid(lseg, tmp_list))
2511                                 continue;
2512                         remaining++;
2513                         set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
2514                         pnfs_lseg_cancel_io(server, lseg);
2515                 }
2516
2517         if (remaining) {
2518                 pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2519                 return -EBUSY;
2520         }
2521
2522         if (!list_empty(&lo->plh_return_segs)) {
2523                 pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2524                 return 0;
2525         }
2526
2527         return -ENOENT;
2528 }
2529
2530 static void
2531 pnfs_mark_layout_for_return(struct inode *inode,
2532                             const struct pnfs_layout_range *range)
2533 {
2534         struct pnfs_layout_hdr *lo;
2535         bool return_now = false;
2536
2537         spin_lock(&inode->i_lock);
2538         lo = NFS_I(inode)->layout;
2539         if (!pnfs_layout_is_valid(lo)) {
2540                 spin_unlock(&inode->i_lock);
2541                 return;
2542         }
2543         pnfs_set_plh_return_info(lo, range->iomode, 0);
2544         /*
2545          * mark all matching lsegs so that we are sure to have no live
2546          * segments at hand when sending layoutreturn. See pnfs_put_lseg()
2547          * for how it works.
2548          */
2549         if (pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs, range, 0) != -EBUSY) {
2550                 const struct cred *cred;
2551                 nfs4_stateid stateid;
2552                 enum pnfs_iomode iomode;
2553
2554                 return_now = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
2555                 spin_unlock(&inode->i_lock);
2556                 if (return_now)
2557                         pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
2558         } else {
2559                 spin_unlock(&inode->i_lock);
2560                 nfs_commit_inode(inode, 0);
2561         }
2562 }
2563
2564 void pnfs_error_mark_layout_for_return(struct inode *inode,
2565                                        struct pnfs_layout_segment *lseg)
2566 {
2567         struct pnfs_layout_range range = {
2568                 .iomode = lseg->pls_range.iomode,
2569                 .offset = 0,
2570                 .length = NFS4_MAX_UINT64,
2571         };
2572
2573         pnfs_mark_layout_for_return(inode, &range);
2574 }
2575 EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
2576
2577 static bool
2578 pnfs_layout_can_be_returned(struct pnfs_layout_hdr *lo)
2579 {
2580         return pnfs_layout_is_valid(lo) &&
2581                 !test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) &&
2582                 !test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
2583 }
2584
2585 static struct pnfs_layout_segment *
2586 pnfs_find_first_lseg(struct pnfs_layout_hdr *lo,
2587                      const struct pnfs_layout_range *range,
2588                      enum pnfs_iomode iomode)
2589 {
2590         struct pnfs_layout_segment *lseg;
2591
2592         list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
2593                 if (!test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
2594                         continue;
2595                 if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
2596                         continue;
2597                 if (lseg->pls_range.iomode != iomode && iomode != IOMODE_ANY)
2598                         continue;
2599                 if (pnfs_lseg_range_intersecting(&lseg->pls_range, range))
2600                         return lseg;
2601         }
2602         return NULL;
2603 }
2604
2605 /* Find open file states whose mode matches that of the range */
2606 static bool
2607 pnfs_should_return_unused_layout(struct pnfs_layout_hdr *lo,
2608                                  const struct pnfs_layout_range *range)
2609 {
2610         struct list_head *head;
2611         struct nfs_open_context *ctx;
2612         fmode_t mode = 0;
2613
2614         if (!pnfs_layout_can_be_returned(lo) ||
2615             !pnfs_find_first_lseg(lo, range, range->iomode))
2616                 return false;
2617
2618         head = &NFS_I(lo->plh_inode)->open_files;
2619         list_for_each_entry_rcu(ctx, head, list) {
2620                 if (ctx->state)
2621                         mode |= ctx->state->state & (FMODE_READ|FMODE_WRITE);
2622         }
2623
2624         switch (range->iomode) {
2625         default:
2626                 break;
2627         case IOMODE_READ:
2628                 mode &= ~FMODE_WRITE;
2629                 break;
2630         case IOMODE_RW:
2631                 if (pnfs_find_first_lseg(lo, range, IOMODE_READ))
2632                         mode &= ~FMODE_READ;
2633         }
2634         return mode == 0;
2635 }
2636
2637 static int pnfs_layout_return_unused_byserver(struct nfs_server *server,
2638                                               void *data)
2639 {
2640         const struct pnfs_layout_range *range = data;
2641         const struct cred *cred;
2642         struct pnfs_layout_hdr *lo;
2643         struct inode *inode;
2644         nfs4_stateid stateid;
2645         enum pnfs_iomode iomode;
2646
2647 restart:
2648         rcu_read_lock();
2649         list_for_each_entry_rcu(lo, &server->layouts, plh_layouts) {
2650                 inode = lo->plh_inode;
2651                 if (!inode || !pnfs_layout_can_be_returned(lo) ||
2652                     test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
2653                         continue;
2654                 spin_lock(&inode->i_lock);
2655                 if (!lo->plh_inode ||
2656                     !pnfs_should_return_unused_layout(lo, range)) {
2657                         spin_unlock(&inode->i_lock);
2658                         continue;
2659                 }
2660                 pnfs_get_layout_hdr(lo);
2661                 pnfs_set_plh_return_info(lo, range->iomode, 0);
2662                 if (pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs,
2663                                                     range, 0) != 0 ||
2664                     !pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode)) {
2665                         spin_unlock(&inode->i_lock);
2666                         rcu_read_unlock();
2667                         pnfs_put_layout_hdr(lo);
2668                         cond_resched();
2669                         goto restart;
2670                 }
2671                 spin_unlock(&inode->i_lock);
2672                 rcu_read_unlock();
2673                 pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
2674                 pnfs_put_layout_hdr(lo);
2675                 cond_resched();
2676                 goto restart;
2677         }
2678         rcu_read_unlock();
2679         return 0;
2680 }
2681
2682 void
2683 pnfs_layout_return_unused_byclid(struct nfs_client *clp,
2684                                  enum pnfs_iomode iomode)
2685 {
2686         struct pnfs_layout_range range = {
2687                 .iomode = iomode,
2688                 .offset = 0,
2689                 .length = NFS4_MAX_UINT64,
2690         };
2691
2692         nfs_client_for_each_server(clp, pnfs_layout_return_unused_byserver,
2693                         &range);
2694 }
2695
2696 void
2697 pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor *pgio)
2698 {
2699         if (pgio->pg_lseg == NULL ||
2700             test_bit(NFS_LSEG_VALID, &pgio->pg_lseg->pls_flags))
2701                 return;
2702         pnfs_put_lseg(pgio->pg_lseg);
2703         pgio->pg_lseg = NULL;
2704 }
2705 EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_layout);
2706
2707 /*
2708  * Check for any intersection between the request and the pgio->pg_lseg,
2709  * and if none, put this pgio->pg_lseg away.
2710  */
2711 void
2712 pnfs_generic_pg_check_range(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2713 {
2714         if (pgio->pg_lseg && !pnfs_lseg_request_intersecting(pgio->pg_lseg, req)) {
2715                 pnfs_put_lseg(pgio->pg_lseg);
2716                 pgio->pg_lseg = NULL;
2717         }
2718 }
2719 EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_range);
2720
2721 void
2722 pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2723 {
2724         u64 rd_size;
2725
2726         pnfs_generic_pg_check_layout(pgio);
2727         pnfs_generic_pg_check_range(pgio, req);
2728         if (pgio->pg_lseg == NULL) {
2729                 if (pgio->pg_dreq == NULL)
2730                         rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
2731                 else
2732                         rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
2733
2734                 pgio->pg_lseg =
2735                         pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
2736                                            req_offset(req), rd_size,
2737                                            IOMODE_READ, false,
2738                                            nfs_io_gfp_mask());
2739                 if (IS_ERR(pgio->pg_lseg)) {
2740                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2741                         pgio->pg_lseg = NULL;
2742                         return;
2743                 }
2744         }
2745         /* If no lseg, fall back to read through mds */
2746         if (pgio->pg_lseg == NULL)
2747                 nfs_pageio_reset_read_mds(pgio);
2748
2749 }
2750 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
2751
2752 void
2753 pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
2754                            struct nfs_page *req, u64 wb_size)
2755 {
2756         pnfs_generic_pg_check_layout(pgio);
2757         pnfs_generic_pg_check_range(pgio, req);
2758         if (pgio->pg_lseg == NULL) {
2759                 pgio->pg_lseg =
2760                         pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
2761                                            req_offset(req), wb_size, IOMODE_RW,
2762                                            false, nfs_io_gfp_mask());
2763                 if (IS_ERR(pgio->pg_lseg)) {
2764                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2765                         pgio->pg_lseg = NULL;
2766                         return;
2767                 }
2768         }
2769         /* If no lseg, fall back to write through mds */
2770         if (pgio->pg_lseg == NULL)
2771                 nfs_pageio_reset_write_mds(pgio);
2772 }
2773 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
2774
2775 void
2776 pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
2777 {
2778         if (desc->pg_lseg) {
2779                 pnfs_put_lseg(desc->pg_lseg);
2780                 desc->pg_lseg = NULL;
2781         }
2782 }
2783 EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
2784
2785 /*
2786  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
2787  * of bytes (maximum @req->wb_bytes) that can be coalesced.
2788  */
2789 size_t
2790 pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
2791                      struct nfs_page *prev, struct nfs_page *req)
2792 {
2793         unsigned int size;
2794         u64 seg_end, req_start, seg_left;
2795
2796         size = nfs_generic_pg_test(pgio, prev, req);
2797         if (!size)
2798                 return 0;
2799
2800         /*
2801          * 'size' contains the number of bytes left in the current page (up
2802          * to the original size asked for in @req->wb_bytes).
2803          *
2804          * Calculate how many bytes are left in the layout segment
2805          * and if there are less bytes than 'size', return that instead.
2806          *
2807          * Please also note that 'end_offset' is actually the offset of the
2808          * first byte that lies outside the pnfs_layout_range. FIXME?
2809          *
2810          */
2811         if (pgio->pg_lseg) {
2812                 seg_end = pnfs_end_offset(pgio->pg_lseg->pls_range.offset,
2813                                      pgio->pg_lseg->pls_range.length);
2814                 req_start = req_offset(req);
2815
2816                 /* start of request is past the last byte of this segment */
2817                 if (req_start >= seg_end)
2818                         return 0;
2819
2820                 /* adjust 'size' iff there are fewer bytes left in the
2821                  * segment than what nfs_generic_pg_test returned */
2822                 seg_left = seg_end - req_start;
2823                 if (seg_left < size)
2824                         size = (unsigned int)seg_left;
2825         }
2826
2827         return size;
2828 }
2829 EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
2830
2831 int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
2832 {
2833         struct nfs_pageio_descriptor pgio;
2834
2835         /* Resend all requests through the MDS */
2836         nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
2837                               hdr->completion_ops);
2838         return nfs_pageio_resend(&pgio, hdr);
2839 }
2840 EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
2841
2842 static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
2843 {
2844
2845         dprintk("pnfs write error = %d\n", hdr->pnfs_error);
2846         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2847             PNFS_LAYOUTRET_ON_ERROR) {
2848                 pnfs_return_layout(hdr->inode);
2849         }
2850         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2851                 hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
2852 }
2853
2854 /*
2855  * Called by non rpc-based layout drivers
2856  */
2857 void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
2858 {
2859         if (likely(!hdr->pnfs_error)) {
2860                 pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
2861                                 hdr->mds_offset + hdr->res.count);
2862                 hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2863         }
2864         trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
2865         if (unlikely(hdr->pnfs_error))
2866                 pnfs_ld_handle_write_error(hdr);
2867         hdr->mds_ops->rpc_release(hdr);
2868 }
2869 EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
2870
2871 static void
2872 pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
2873                 struct nfs_pgio_header *hdr)
2874 {
2875         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2876
2877         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2878                 list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2879                 nfs_pageio_reset_write_mds(desc);
2880                 mirror->pg_recoalesce = 1;
2881         }
2882         hdr->completion_ops->completion(hdr);
2883 }
2884
2885 static enum pnfs_try_status
2886 pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
2887                         const struct rpc_call_ops *call_ops,
2888                         struct pnfs_layout_segment *lseg,
2889                         int how)
2890 {
2891         struct inode *inode = hdr->inode;
2892         enum pnfs_try_status trypnfs;
2893         struct nfs_server *nfss = NFS_SERVER(inode);
2894
2895         hdr->mds_ops = call_ops;
2896
2897         dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
2898                 inode->i_ino, hdr->args.count, hdr->args.offset, how);
2899         trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
2900         if (trypnfs != PNFS_NOT_ATTEMPTED)
2901                 nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
2902         dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2903         return trypnfs;
2904 }
2905
2906 static void
2907 pnfs_do_write(struct nfs_pageio_descriptor *desc,
2908               struct nfs_pgio_header *hdr, int how)
2909 {
2910         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2911         struct pnfs_layout_segment *lseg = desc->pg_lseg;
2912         enum pnfs_try_status trypnfs;
2913
2914         trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
2915         switch (trypnfs) {
2916         case PNFS_NOT_ATTEMPTED:
2917                 pnfs_write_through_mds(desc, hdr);
2918                 break;
2919         case PNFS_ATTEMPTED:
2920                 break;
2921         case PNFS_TRY_AGAIN:
2922                 /* cleanup hdr and prepare to redo pnfs */
2923                 if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2924                         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2925                         list_splice_init(&hdr->pages, &mirror->pg_list);
2926                         mirror->pg_recoalesce = 1;
2927                 }
2928                 hdr->mds_ops->rpc_release(hdr);
2929         }
2930 }
2931
2932 static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
2933 {
2934         pnfs_put_lseg(hdr->lseg);
2935         nfs_pgio_header_free(hdr);
2936 }
2937
2938 int
2939 pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
2940 {
2941         struct nfs_pgio_header *hdr;
2942         int ret;
2943
2944         hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2945         if (!hdr) {
2946                 desc->pg_error = -ENOMEM;
2947                 return desc->pg_error;
2948         }
2949         nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
2950
2951         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2952         ret = nfs_generic_pgio(desc, hdr);
2953         if (!ret)
2954                 pnfs_do_write(desc, hdr, desc->pg_ioflags);
2955
2956         return ret;
2957 }
2958 EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
2959
2960 int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
2961 {
2962         struct nfs_pageio_descriptor pgio;
2963
2964         /* Resend all requests through the MDS */
2965         nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
2966         return nfs_pageio_resend(&pgio, hdr);
2967 }
2968 EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
2969
2970 static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
2971 {
2972         dprintk("pnfs read error = %d\n", hdr->pnfs_error);
2973         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2974             PNFS_LAYOUTRET_ON_ERROR) {
2975                 pnfs_return_layout(hdr->inode);
2976         }
2977         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2978                 hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
2979 }
2980
2981 /*
2982  * Called by non rpc-based layout drivers
2983  */
2984 void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
2985 {
2986         if (likely(!hdr->pnfs_error))
2987                 hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2988         trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
2989         if (unlikely(hdr->pnfs_error))
2990                 pnfs_ld_handle_read_error(hdr);
2991         hdr->mds_ops->rpc_release(hdr);
2992 }
2993 EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
2994
2995 static void
2996 pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
2997                 struct nfs_pgio_header *hdr)
2998 {
2999         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
3000
3001         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3002                 list_splice_tail_init(&hdr->pages, &mirror->pg_list);
3003                 nfs_pageio_reset_read_mds(desc);
3004                 mirror->pg_recoalesce = 1;
3005         }
3006         hdr->completion_ops->completion(hdr);
3007 }
3008
3009 /*
3010  * Call the appropriate parallel I/O subsystem read function.
3011  */
3012 static enum pnfs_try_status
3013 pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
3014                        const struct rpc_call_ops *call_ops,
3015                        struct pnfs_layout_segment *lseg)
3016 {
3017         struct inode *inode = hdr->inode;
3018         struct nfs_server *nfss = NFS_SERVER(inode);
3019         enum pnfs_try_status trypnfs;
3020
3021         hdr->mds_ops = call_ops;
3022
3023         dprintk("%s: Reading ino:%lu %u@%llu\n",
3024                 __func__, inode->i_ino, hdr->args.count, hdr->args.offset);
3025
3026         trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
3027         if (trypnfs != PNFS_NOT_ATTEMPTED)
3028                 nfs_inc_stats(inode, NFSIOS_PNFS_READ);
3029         dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
3030         return trypnfs;
3031 }
3032
3033 /* Resend all requests through pnfs. */
3034 void pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr,
3035                            unsigned int mirror_idx)
3036 {
3037         struct nfs_pageio_descriptor pgio;
3038
3039         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3040                 /* Prevent deadlocks with layoutreturn! */
3041                 pnfs_put_lseg(hdr->lseg);
3042                 hdr->lseg = NULL;
3043
3044                 nfs_pageio_init_read(&pgio, hdr->inode, false,
3045                                         hdr->completion_ops);
3046                 pgio.pg_mirror_idx = mirror_idx;
3047                 hdr->task.tk_status = nfs_pageio_resend(&pgio, hdr);
3048         }
3049 }
3050 EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
3051
3052 static void
3053 pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
3054 {
3055         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
3056         struct pnfs_layout_segment *lseg = desc->pg_lseg;
3057         enum pnfs_try_status trypnfs;
3058
3059         trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
3060         switch (trypnfs) {
3061         case PNFS_NOT_ATTEMPTED:
3062                 pnfs_read_through_mds(desc, hdr);
3063                 break;
3064         case PNFS_ATTEMPTED:
3065                 break;
3066         case PNFS_TRY_AGAIN:
3067                 /* cleanup hdr and prepare to redo pnfs */
3068                 if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3069                         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
3070                         list_splice_init(&hdr->pages, &mirror->pg_list);
3071                         mirror->pg_recoalesce = 1;
3072                 }
3073                 hdr->mds_ops->rpc_release(hdr);
3074         }
3075 }
3076
3077 static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
3078 {
3079         pnfs_put_lseg(hdr->lseg);
3080         nfs_pgio_header_free(hdr);
3081 }
3082
3083 int
3084 pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
3085 {
3086         struct nfs_pgio_header *hdr;
3087         int ret;
3088
3089         hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
3090         if (!hdr) {
3091                 desc->pg_error = -ENOMEM;
3092                 return desc->pg_error;
3093         }
3094         nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
3095         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
3096         ret = nfs_generic_pgio(desc, hdr);
3097         if (!ret)
3098                 pnfs_do_read(desc, hdr);
3099         return ret;
3100 }
3101 EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
3102
3103 static void pnfs_clear_layoutcommitting(struct inode *inode)
3104 {
3105         unsigned long *bitlock = &NFS_I(inode)->flags;
3106
3107         clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
3108         smp_mb__after_atomic();
3109         wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
3110 }
3111
3112 /*
3113  * There can be multiple RW segments.
3114  */
3115 static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
3116 {
3117         struct pnfs_layout_segment *lseg;
3118
3119         list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
3120                 if (lseg->pls_range.iomode == IOMODE_RW &&
3121                     test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
3122                         list_add(&lseg->pls_lc_list, listp);
3123         }
3124 }
3125
3126 static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
3127 {
3128         struct pnfs_layout_segment *lseg, *tmp;
3129
3130         /* Matched by references in pnfs_set_layoutcommit */
3131         list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
3132                 list_del_init(&lseg->pls_lc_list);
3133                 pnfs_put_lseg(lseg);
3134         }
3135
3136         pnfs_clear_layoutcommitting(inode);
3137 }
3138
3139 void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
3140 {
3141         pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
3142 }
3143 EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
3144
3145 void
3146 pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
3147                 loff_t end_pos)
3148 {
3149         struct nfs_inode *nfsi = NFS_I(inode);
3150         bool mark_as_dirty = false;
3151
3152         spin_lock(&inode->i_lock);
3153         if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
3154                 nfsi->layout->plh_lwb = end_pos;
3155                 mark_as_dirty = true;
3156                 dprintk("%s: Set layoutcommit for inode %lu ",
3157                         __func__, inode->i_ino);
3158         } else if (end_pos > nfsi->layout->plh_lwb)
3159                 nfsi->layout->plh_lwb = end_pos;
3160         if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
3161                 /* references matched in nfs4_layoutcommit_release */
3162                 pnfs_get_lseg(lseg);
3163         }
3164         spin_unlock(&inode->i_lock);
3165         dprintk("%s: lseg %p end_pos %llu\n",
3166                 __func__, lseg, nfsi->layout->plh_lwb);
3167
3168         /* if pnfs_layoutcommit_inode() runs between inode locks, the next one
3169          * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
3170         if (mark_as_dirty)
3171                 mark_inode_dirty_sync(inode);
3172 }
3173 EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
3174
3175 void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
3176 {
3177         struct nfs_server *nfss = NFS_SERVER(data->args.inode);
3178
3179         if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
3180                 nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
3181         pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
3182 }
3183
3184 /*
3185  * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
3186  * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
3187  * data to disk to allow the server to recover the data if it crashes.
3188  * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
3189  * is off, and a COMMIT is sent to a data server, or
3190  * if WRITEs to a data server return NFS_DATA_SYNC.
3191  */
3192 int
3193 pnfs_layoutcommit_inode(struct inode *inode, bool sync)
3194 {
3195         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3196         struct nfs4_layoutcommit_data *data;
3197         struct nfs_inode *nfsi = NFS_I(inode);
3198         loff_t end_pos;
3199         int status;
3200
3201         if (!pnfs_layoutcommit_outstanding(inode))
3202                 return 0;
3203
3204         dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
3205
3206         status = -EAGAIN;
3207         if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
3208                 if (!sync)
3209                         goto out;
3210                 status = wait_on_bit_lock_action(&nfsi->flags,
3211                                 NFS_INO_LAYOUTCOMMITTING,
3212                                 nfs_wait_bit_killable,
3213                                 TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
3214                 if (status)
3215                         goto out;
3216         }
3217
3218         status = -ENOMEM;
3219         /* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
3220         data = kzalloc(sizeof(*data), nfs_io_gfp_mask());
3221         if (!data)
3222                 goto clear_layoutcommitting;
3223
3224         status = 0;
3225         spin_lock(&inode->i_lock);
3226         if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
3227                 goto out_unlock;
3228
3229         INIT_LIST_HEAD(&data->lseg_list);
3230         pnfs_list_write_lseg(inode, &data->lseg_list);
3231
3232         end_pos = nfsi->layout->plh_lwb;
3233
3234         nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
3235         data->cred = get_cred(nfsi->layout->plh_lc_cred);
3236         spin_unlock(&inode->i_lock);
3237
3238         data->args.inode = inode;
3239         nfs_fattr_init(&data->fattr);
3240         data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
3241         data->res.fattr = &data->fattr;
3242         if (end_pos != 0)
3243                 data->args.lastbytewritten = end_pos - 1;
3244         else
3245                 data->args.lastbytewritten = U64_MAX;
3246         data->res.server = NFS_SERVER(inode);
3247
3248         if (ld->prepare_layoutcommit) {
3249                 status = ld->prepare_layoutcommit(&data->args);
3250                 if (status) {
3251                         put_cred(data->cred);
3252                         spin_lock(&inode->i_lock);
3253                         set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
3254                         if (end_pos > nfsi->layout->plh_lwb)
3255                                 nfsi->layout->plh_lwb = end_pos;
3256                         goto out_unlock;
3257                 }
3258         }
3259
3260
3261         status = nfs4_proc_layoutcommit(data, sync);
3262 out:
3263         if (status)
3264                 mark_inode_dirty_sync(inode);
3265         dprintk("<-- %s status %d\n", __func__, status);
3266         return status;
3267 out_unlock:
3268         spin_unlock(&inode->i_lock);
3269         kfree(data);
3270 clear_layoutcommitting:
3271         pnfs_clear_layoutcommitting(inode);
3272         goto out;
3273 }
3274 EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
3275
3276 int
3277 pnfs_generic_sync(struct inode *inode, bool datasync)
3278 {
3279         return pnfs_layoutcommit_inode(inode, true);
3280 }
3281 EXPORT_SYMBOL_GPL(pnfs_generic_sync);
3282
3283 struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
3284 {
3285         struct nfs4_threshold *thp;
3286
3287         thp = kzalloc(sizeof(*thp), nfs_io_gfp_mask());
3288         if (!thp) {
3289                 dprintk("%s mdsthreshold allocation failed\n", __func__);
3290                 return NULL;
3291         }
3292         return thp;
3293 }
3294
3295 #if IS_ENABLED(CONFIG_NFS_V4_2)
3296 int
3297 pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
3298 {
3299         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3300         struct nfs_server *server = NFS_SERVER(inode);
3301         struct nfs_inode *nfsi = NFS_I(inode);
3302         struct nfs42_layoutstat_data *data;
3303         struct pnfs_layout_hdr *hdr;
3304         int status = 0;
3305
3306         if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
3307                 goto out;
3308
3309         if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
3310                 goto out;
3311
3312         if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
3313                 goto out;
3314
3315         spin_lock(&inode->i_lock);
3316         if (!NFS_I(inode)->layout) {
3317                 spin_unlock(&inode->i_lock);
3318                 goto out_clear_layoutstats;
3319         }
3320         hdr = NFS_I(inode)->layout;
3321         pnfs_get_layout_hdr(hdr);
3322         spin_unlock(&inode->i_lock);
3323
3324         data = kzalloc(sizeof(*data), gfp_flags);
3325         if (!data) {
3326                 status = -ENOMEM;
3327                 goto out_put;
3328         }
3329
3330         data->args.fh = NFS_FH(inode);
3331         data->args.inode = inode;
3332         status = ld->prepare_layoutstats(&data->args);
3333         if (status)
3334                 goto out_free;
3335
3336         status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
3337
3338 out:
3339         dprintk("%s returns %d\n", __func__, status);
3340         return status;
3341
3342 out_free:
3343         kfree(data);
3344 out_put:
3345         pnfs_put_layout_hdr(hdr);
3346 out_clear_layoutstats:
3347         smp_mb__before_atomic();
3348         clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
3349         smp_mb__after_atomic();
3350         goto out;
3351 }
3352 EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
3353 #endif
3354
3355 unsigned int layoutstats_timer;
3356 module_param(layoutstats_timer, uint, 0644);
3357 EXPORT_SYMBOL_GPL(layoutstats_timer);