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