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