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 <[email protected]>
   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 (!list_empty(&lo->plh_layouts)) {
 272                 struct nfs_client *clp = server->nfs_client;
 273
 274                 spin_lock(&clp->cl_lock);
 275                 list_del_init(&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 void
 313 pnfs_set_plh_return_info(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode,
 314                          u32 seq)
 315 {
 316         if (lo->plh_return_iomode != 0 && lo->plh_return_iomode != iomode)
 317                 iomode = IOMODE_ANY;
 318         lo->plh_return_iomode = iomode;
 319         set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 320         if (seq != 0) {
 321                 WARN_ON_ONCE(lo->plh_return_seq != 0 && lo->plh_return_seq != seq);
 322                 lo->plh_return_seq = seq;
 323         }
 324 }
 325
 326 static void
 327 pnfs_clear_layoutreturn_info(struct pnfs_layout_hdr *lo)
 328 {
 329         struct pnfs_layout_segment *lseg;
 330         lo->plh_return_iomode = 0;
 331         lo->plh_return_seq = 0;
 332         clear_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 333         list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
 334                 if (!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 335                         continue;
 336                 pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 337         }
 338 }
 339
 340 static void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
 341 {
 342         clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
 343         clear_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags);
 344         smp_mb__after_atomic();
 345         wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
 346         rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
 347 }
 348
 349 static void
 350 pnfs_clear_lseg_state(struct pnfs_layout_segment *lseg,
 351                 struct list_head *free_me)
 352 {
 353         clear_bit(NFS_LSEG_ROC, &lseg->pls_flags);
 354         clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
 355         if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 356                 pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 357         if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 358                 pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 359 }
 360
 361 /*
 362  * Update the seqid of a layout stateid
 363  */
 364 bool nfs4_layoutreturn_refresh_stateid(nfs4_stateid *dst,
 365                 struct pnfs_layout_range *dst_range,
 366                 struct inode *inode)
 367 {
 368         struct pnfs_layout_hdr *lo;
 369         struct pnfs_layout_range range = {
 370                 .iomode = IOMODE_ANY,
 371                 .offset = 0,
 372                 .length = NFS4_MAX_UINT64,
 373         };
 374         bool ret = false;
 375         LIST_HEAD(head);
 376         int err;
 377
 378         spin_lock(&inode->i_lock);
 379         lo = NFS_I(inode)->layout;
 380         if (lo && nfs4_stateid_match_other(dst, &lo->plh_stateid)) {
 381                 err = pnfs_mark_matching_lsegs_return(lo, &head, &range, 0);
 382                 if (err != -EBUSY) {
 383                         dst->seqid = lo->plh_stateid.seqid;
 384                         *dst_range = range;
 385                         ret = true;
 386                 }
 387         }
 388         spin_unlock(&inode->i_lock);
 389         pnfs_free_lseg_list(&head);
 390         return ret;
 391 }
 392
 393 /*
 394  * Mark a pnfs_layout_hdr and all associated layout segments as invalid
 395  *
 396  * In order to continue using the pnfs_layout_hdr, a full recovery
 397  * is required.
 398  * Note that caller must hold inode->i_lock.
 399  */
 400 int
 401 pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
 402                 struct list_head *lseg_list)
 403 {
 404         struct pnfs_layout_range range = {
 405                 .iomode = IOMODE_ANY,
 406                 .offset = 0,
 407                 .length = NFS4_MAX_UINT64,
 408         };
 409         struct pnfs_layout_segment *lseg, *next;
 410
 411         set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 412         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 413                 pnfs_clear_lseg_state(lseg, lseg_list);
 414         pnfs_clear_layoutreturn_info(lo);
 415         pnfs_free_returned_lsegs(lo, lseg_list, &range, 0);
 416         if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) &&
 417             !test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
 418                 pnfs_clear_layoutreturn_waitbit(lo);
 419         return !list_empty(&lo->plh_segs);
 420 }
 421
 422 static int
 423 pnfs_iomode_to_fail_bit(u32 iomode)
 424 {
 425         return iomode == IOMODE_RW ?
 426                 NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 427 }
 428
 429 static void
 430 pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 431 {
 432         lo->plh_retry_timestamp = jiffies;
 433         if (!test_and_set_bit(fail_bit, &lo->plh_flags))
 434                 refcount_inc(&lo->plh_refcount);
 435 }
 436
 437 static void
 438 pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 439 {
 440         if (test_and_clear_bit(fail_bit, &lo->plh_flags))
 441                 refcount_dec(&lo->plh_refcount);
 442 }
 443
 444 static void
 445 pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 446 {
 447         struct inode *inode = lo->plh_inode;
 448         struct pnfs_layout_range range = {
 449                 .iomode = iomode,
 450                 .offset = 0,
 451                 .length = NFS4_MAX_UINT64,
 452         };
 453         LIST_HEAD(head);
 454
 455         spin_lock(&inode->i_lock);
 456         pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
 457         pnfs_mark_matching_lsegs_invalid(lo, &head, &range, 0);
 458         spin_unlock(&inode->i_lock);
 459         pnfs_free_lseg_list(&head);
 460         dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
 461                         iomode == IOMODE_RW ?  "RW" : "READ");
 462 }
 463
 464 static bool
 465 pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 466 {
 467         unsigned long start, end;
 468         int fail_bit = pnfs_iomode_to_fail_bit(iomode);
 469
 470         if (test_bit(fail_bit, &lo->plh_flags) == 0)
 471                 return false;
 472         end = jiffies;
 473         start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
 474         if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
 475                 /* It is time to retry the failed layoutgets */
 476                 pnfs_layout_clear_fail_bit(lo, fail_bit);
 477                 return false;
 478         }
 479         return true;
 480 }
 481
 482 static void
 483 pnfs_init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg,
 484                 const struct pnfs_layout_range *range,
 485                 const nfs4_stateid *stateid)
 486 {
 487         INIT_LIST_HEAD(&lseg->pls_list);
 488         INIT_LIST_HEAD(&lseg->pls_lc_list);
 489         refcount_set(&lseg->pls_refcount, 1);
 490         set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
 491         lseg->pls_layout = lo;
 492         lseg->pls_range = *range;
 493         lseg->pls_seq = be32_to_cpu(stateid->seqid);
 494 }
 495
 496 static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
 497 {
 498         if (lseg != NULL) {
 499                 struct inode *inode = lseg->pls_layout->plh_inode;
 500                 NFS_SERVER(inode)->pnfs_curr_ld->free_lseg(lseg);
 501         }
 502 }
 503
 504 static void
 505 pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 506                 struct pnfs_layout_segment *lseg)
 507 {
 508         WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 509         list_del_init(&lseg->pls_list);
 510         /* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 511         refcount_dec(&lo->plh_refcount);
 512         if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 513                 return;
 514         if (list_empty(&lo->plh_segs) &&
 515             !test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
 516             !test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
 517                 if (atomic_read(&lo->plh_outstanding) == 0)
 518                         set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 519                 clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 520         }
 521 }
 522
 523 static bool
 524 pnfs_cache_lseg_for_layoutreturn(struct pnfs_layout_hdr *lo,
 525                 struct pnfs_layout_segment *lseg)
 526 {
 527         if (test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
 528             pnfs_layout_is_valid(lo)) {
 529                 pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 530                 list_move_tail(&lseg->pls_list, &lo->plh_return_segs);
 531                 return true;
 532         }
 533         return false;
 534 }
 535
 536 void
 537 pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 538 {
 539         struct pnfs_layout_hdr *lo;
 540         struct inode *inode;
 541
 542         if (!lseg)
 543                 return;
 544
 545         dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 546                 refcount_read(&lseg->pls_refcount),
 547                 test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 548
 549         lo = lseg->pls_layout;
 550         inode = lo->plh_inode;
 551
 552         if (refcount_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
 553                 if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 554                         spin_unlock(&inode->i_lock);
 555                         return;
 556                 }
 557                 pnfs_get_layout_hdr(lo);
 558                 pnfs_layout_remove_lseg(lo, lseg);
 559                 if (pnfs_cache_lseg_for_layoutreturn(lo, lseg))
 560                         lseg = NULL;
 561                 spin_unlock(&inode->i_lock);
 562                 pnfs_free_lseg(lseg);
 563                 pnfs_put_layout_hdr(lo);
 564         }
 565 }
 566 EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 567
 568 /*
 569  * is l2 fully contained in l1?
 570  *   start1                             end1
 571  *   [----------------------------------)
 572  *           start2           end2
 573  *           [----------------)
 574  */
 575 static bool
 576 pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
 577                  const struct pnfs_layout_range *l2)
 578 {
 579         u64 start1 = l1->offset;
 580         u64 end1 = pnfs_end_offset(start1, l1->length);
 581         u64 start2 = l2->offset;
 582         u64 end2 = pnfs_end_offset(start2, l2->length);
 583
 584         return (start1 <= start2) && (end1 >= end2);
 585 }
 586
 587 static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
 588                 struct list_head *tmp_list)
 589 {
 590         if (!refcount_dec_and_test(&lseg->pls_refcount))
 591                 return false;
 592         pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
 593         list_add(&lseg->pls_list, tmp_list);
 594         return true;
 595 }
 596
 597 /* Returns 1 if lseg is removed from list, 0 otherwise */
 598 static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
 599                              struct list_head *tmp_list)
 600 {
 601         int rv = 0;
 602
 603         if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 604                 /* Remove the reference keeping the lseg in the
 605                  * list.  It will now be removed when all
 606                  * outstanding io is finished.
 607                  */
 608                 dprintk("%s: lseg %p ref %d\n", __func__, lseg,
 609                         refcount_read(&lseg->pls_refcount));
 610                 if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
 611                         rv = 1;
 612         }
 613         return rv;
 614 }
 615
 616 /*
 617  * Compare 2 layout stateid sequence ids, to see which is newer,
 618  * taking into account wraparound issues.
 619  */
 620 static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
 621 {
 622         return (s32)(s1 - s2) > 0;
 623 }
 624
 625 static bool
 626 pnfs_should_free_range(const struct pnfs_layout_range *lseg_range,
 627                  const struct pnfs_layout_range *recall_range)
 628 {
 629         return (recall_range->iomode == IOMODE_ANY ||
 630                 lseg_range->iomode == recall_range->iomode) &&
 631                pnfs_lseg_range_intersecting(lseg_range, recall_range);
 632 }
 633
 634 static bool
 635 pnfs_match_lseg_recall(const struct pnfs_layout_segment *lseg,
 636                 const struct pnfs_layout_range *recall_range,
 637                 u32 seq)
 638 {
 639         if (seq != 0 && pnfs_seqid_is_newer(lseg->pls_seq, seq))
 640                 return false;
 641         if (recall_range == NULL)
 642                 return true;
 643         return pnfs_should_free_range(&lseg->pls_range, recall_range);
 644 }
 645
 646 /**
 647  * pnfs_mark_matching_lsegs_invalid - tear down lsegs or mark them for later
 648  * @lo: layout header containing the lsegs
 649  * @tmp_list: list head where doomed lsegs should go
 650  * @recall_range: optional recall range argument to match (may be NULL)
 651  * @seq: only invalidate lsegs obtained prior to this sequence (may be 0)
 652  *
 653  * Walk the list of lsegs in the layout header, and tear down any that should
 654  * be destroyed. If "recall_range" is specified then the segment must match
 655  * that range. If "seq" is non-zero, then only match segments that were handed
 656  * out at or before that sequence.
 657  *
 658  * Returns number of matching invalid lsegs remaining in list after scanning
 659  * it and purging them.
 660  */
 661 int
 662 pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 663                             struct list_head *tmp_list,
 664                             const struct pnfs_layout_range *recall_range,
 665                             u32 seq)
 666 {
 667         struct pnfs_layout_segment *lseg, *next;
 668         int remaining = 0;
 669
 670         dprintk("%s:Begin lo %p\n", __func__, lo);
 671
 672         if (list_empty(&lo->plh_segs))
 673                 return 0;
 674         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 675                 if (pnfs_match_lseg_recall(lseg, recall_range, seq)) {
 676                         dprintk("%s: freeing lseg %p iomode %d seq %u "
 677                                 "offset %llu length %llu\n", __func__,
 678                                 lseg, lseg->pls_range.iomode, lseg->pls_seq,
 679                                 lseg->pls_range.offset, lseg->pls_range.length);
 680                         if (!mark_lseg_invalid(lseg, tmp_list))
 681                                 remaining++;
 682                 }
 683         dprintk("%s:Return %i\n", __func__, remaining);
 684         return remaining;
 685 }
 686
 687 static void
 688 pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
 689                 struct list_head *free_me,
 690                 const struct pnfs_layout_range *range,
 691                 u32 seq)
 692 {
 693         struct pnfs_layout_segment *lseg, *next;
 694
 695         list_for_each_entry_safe(lseg, next, &lo->plh_return_segs, pls_list) {
 696                 if (pnfs_match_lseg_recall(lseg, range, seq))
 697                         list_move_tail(&lseg->pls_list, free_me);
 698         }
 699 }
 700
 701 /* note free_me must contain lsegs from a single layout_hdr */
 702 void
 703 pnfs_free_lseg_list(struct list_head *free_me)
 704 {
 705         struct pnfs_layout_segment *lseg, *tmp;
 706
 707         if (list_empty(free_me))
 708                 return;
 709
 710         list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
 711                 list_del(&lseg->pls_list);
 712                 pnfs_free_lseg(lseg);
 713         }
 714 }
 715
 716 void
 717 pnfs_destroy_layout(struct nfs_inode *nfsi)
 718 {
 719         struct pnfs_layout_hdr *lo;
 720         LIST_HEAD(tmp_list);
 721
 722         spin_lock(&nfsi->vfs_inode.i_lock);
 723         lo = nfsi->layout;
 724         if (lo) {
 725                 pnfs_get_layout_hdr(lo);
 726                 pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
 727                 pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
 728                 pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
 729                 spin_unlock(&nfsi->vfs_inode.i_lock);
 730                 pnfs_free_lseg_list(&tmp_list);
 731                 nfs_commit_inode(&nfsi->vfs_inode, 0);
 732                 pnfs_put_layout_hdr(lo);
 733         } else
 734                 spin_unlock(&nfsi->vfs_inode.i_lock);
 735 }
 736 EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
 737
 738 static bool
 739 pnfs_layout_add_bulk_destroy_list(struct inode *inode,
 740                 struct list_head *layout_list)
 741 {
 742         struct pnfs_layout_hdr *lo;
 743         bool ret = false;
 744
 745         spin_lock(&inode->i_lock);
 746         lo = NFS_I(inode)->layout;
 747         if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
 748                 pnfs_get_layout_hdr(lo);
 749                 list_add(&lo->plh_bulk_destroy, layout_list);
 750                 ret = true;
 751         }
 752         spin_unlock(&inode->i_lock);
 753         return ret;
 754 }
 755
 756 /* Caller must hold rcu_read_lock and clp->cl_lock */
 757 static int
 758 pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
 759                 struct nfs_server *server,
 760                 struct list_head *layout_list)
 761         __must_hold(&clp->cl_lock)
 762         __must_hold(RCU)
 763 {
 764         struct pnfs_layout_hdr *lo, *next;
 765         struct inode *inode;
 766
 767         list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
 768                 if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) ||
 769                     test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) ||
 770                     !list_empty(&lo->plh_bulk_destroy))
 771                         continue;
 772                 /* If the sb is being destroyed, just bail */
 773                 if (!nfs_sb_active(server->super))
 774                         break;
 775                 inode = igrab(lo->plh_inode);
 776                 if (inode != NULL) {
 777                         list_del_init(&lo->plh_layouts);
 778                         if (pnfs_layout_add_bulk_destroy_list(inode,
 779                                                 layout_list))
 780                                 continue;
 781                         rcu_read_unlock();
 782                         spin_unlock(&clp->cl_lock);
 783                         iput(inode);
 784                 } else {
 785                         rcu_read_unlock();
 786                         spin_unlock(&clp->cl_lock);
 787                         set_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags);
 788                 }
 789                 nfs_sb_deactive(server->super);
 790                 spin_lock(&clp->cl_lock);
 791                 rcu_read_lock();
 792                 return -EAGAIN;
 793         }
 794         return 0;
 795 }
 796
 797 static int
 798 pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
 799                 bool is_bulk_recall)
 800 {
 801         struct pnfs_layout_hdr *lo;
 802         struct inode *inode;
 803         LIST_HEAD(lseg_list);
 804         int ret = 0;
 805
 806         while (!list_empty(layout_list)) {
 807                 lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
 808                                 plh_bulk_destroy);
 809                 dprintk("%s freeing layout for inode %lu\n", __func__,
 810                         lo->plh_inode->i_ino);
 811                 inode = lo->plh_inode;
 812
 813                 pnfs_layoutcommit_inode(inode, false);
 814
 815                 spin_lock(&inode->i_lock);
 816                 list_del_init(&lo->plh_bulk_destroy);
 817                 if (pnfs_mark_layout_stateid_invalid(lo, &lseg_list)) {
 818                         if (is_bulk_recall)
 819                                 set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 820                         ret = -EAGAIN;
 821                 }
 822                 spin_unlock(&inode->i_lock);
 823                 pnfs_free_lseg_list(&lseg_list);
 824                 /* Free all lsegs that are attached to commit buckets */
 825                 nfs_commit_inode(inode, 0);
 826                 pnfs_put_layout_hdr(lo);
 827                 nfs_iput_and_deactive(inode);
 828         }
 829         return ret;
 830 }
 831
 832 int
 833 pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
 834                 struct nfs_fsid *fsid,
 835                 bool is_recall)
 836 {
 837         struct nfs_server *server;
 838         LIST_HEAD(layout_list);
 839
 840         spin_lock(&clp->cl_lock);
 841         rcu_read_lock();
 842 restart:
 843         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 844                 if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
 845                         continue;
 846                 if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 847                                 server,
 848                                 &layout_list) != 0)
 849                         goto restart;
 850         }
 851         rcu_read_unlock();
 852         spin_unlock(&clp->cl_lock);
 853
 854         if (list_empty(&layout_list))
 855                 return 0;
 856         return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 857 }
 858
 859 int
 860 pnfs_destroy_layouts_byclid(struct nfs_client *clp,
 861                 bool is_recall)
 862 {
 863         struct nfs_server *server;
 864         LIST_HEAD(layout_list);
 865
 866         spin_lock(&clp->cl_lock);
 867         rcu_read_lock();
 868 restart:
 869         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 870                 if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 871                                         server,
 872                                         &layout_list) != 0)
 873                         goto restart;
 874         }
 875         rcu_read_unlock();
 876         spin_unlock(&clp->cl_lock);
 877
 878         if (list_empty(&layout_list))
 879                 return 0;
 880         return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 881 }
 882
 883 /*
 884  * Called by the state manger to remove all layouts established under an
 885  * expired lease.
 886  */
 887 void
 888 pnfs_destroy_all_layouts(struct nfs_client *clp)
 889 {
 890         nfs4_deviceid_mark_client_invalid(clp);
 891         nfs4_deviceid_purge_client(clp);
 892
 893         pnfs_destroy_layouts_byclid(clp, false);
 894 }
 895
 896 /* update lo->plh_stateid with new if is more recent */
 897 void
 898 pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
 899                         bool update_barrier)
 900 {
 901         u32 oldseq, newseq, new_barrier = 0;
 902
 903         oldseq = be32_to_cpu(lo->plh_stateid.seqid);
 904         newseq = be32_to_cpu(new->seqid);
 905
 906         if (!pnfs_layout_is_valid(lo)) {
 907                 nfs4_stateid_copy(&lo->plh_stateid, new);
 908                 lo->plh_barrier = newseq;
 909                 pnfs_clear_layoutreturn_info(lo);
 910                 clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 911                 return;
 912         }
 913         if (pnfs_seqid_is_newer(newseq, oldseq)) {
 914                 nfs4_stateid_copy(&lo->plh_stateid, new);
 915                 /*
 916                  * Because of wraparound, we want to keep the barrier
 917                  * "close" to the current seqids.
 918                  */
 919                 new_barrier = newseq - atomic_read(&lo->plh_outstanding);
 920         }
 921         if (update_barrier)
 922                 new_barrier = be32_to_cpu(new->seqid);
 923         else if (new_barrier == 0)
 924                 return;
 925         if (pnfs_seqid_is_newer(new_barrier, lo->plh_barrier))
 926                 lo->plh_barrier = new_barrier;
 927 }
 928
 929 static bool
 930 pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
 931                 const nfs4_stateid *stateid)
 932 {
 933         u32 seqid = be32_to_cpu(stateid->seqid);
 934
 935         return !pnfs_seqid_is_newer(seqid, lo->plh_barrier);
 936 }
 937
 938 /* lget is set to 1 if called from inside send_layoutget call chain */
 939 static bool
 940 pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
 941 {
 942         return lo->plh_block_lgets ||
 943                 test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 944 }
 945
 946 static struct nfs_server *
 947 pnfs_find_server(struct inode *inode, struct nfs_open_context *ctx)
 948 {
 949         struct nfs_server *server;
 950
 951         if (inode) {
 952                 server = NFS_SERVER(inode);
 953         } else {
 954                 struct dentry *parent_dir = dget_parent(ctx->dentry);
 955                 server = NFS_SERVER(parent_dir->d_inode);
 956                 dput(parent_dir);
 957         }
 958         return server;
 959 }
 960
 961 static void nfs4_free_pages(struct page **pages, size_t size)
 962 {
 963         int i;
 964
 965         if (!pages)
 966                 return;
 967
 968         for (i = 0; i < size; i++) {
 969                 if (!pages[i])
 970                         break;
 971                 __free_page(pages[i]);
 972         }
 973         kfree(pages);
 974 }
 975
 976 static struct page **nfs4_alloc_pages(size_t size, gfp_t gfp_flags)
 977 {
 978         struct page **pages;
 979         int i;
 980
 981         pages = kmalloc_array(size, sizeof(struct page *), gfp_flags);
 982         if (!pages) {
 983                 dprintk("%s: can't alloc array of %zu pages\n", __func__, size);
 984                 return NULL;
 985         }
 986
 987         for (i = 0; i < size; i++) {
 988                 pages[i] = alloc_page(gfp_flags);
 989                 if (!pages[i]) {
 990                         dprintk("%s: failed to allocate page\n", __func__);
 991                         nfs4_free_pages(pages, i);
 992                         return NULL;
 993                 }
 994         }
 995
 996         return pages;
 997 }
 998
 999 static struct nfs4_layoutget *
1000 pnfs_alloc_init_layoutget_args(struct inode *ino,
1001            struct nfs_open_context *ctx,
1002            const nfs4_stateid *stateid,
1003            const struct pnfs_layout_range *range,
1004            gfp_t gfp_flags)
1005 {
1006         struct nfs_server *server = pnfs_find_server(ino, ctx);
1007         size_t max_reply_sz = server->pnfs_curr_ld->max_layoutget_response;
1008         size_t max_pages = max_response_pages(server);
1009         struct nfs4_layoutget *lgp;
1010
1011         dprintk("--> %s\n", __func__);
1012
1013         lgp = kzalloc(sizeof(*lgp), gfp_flags);
1014         if (lgp == NULL)
1015                 return NULL;
1016
1017         if (max_reply_sz) {
1018                 size_t npages = (max_reply_sz + PAGE_SIZE - 1) >> PAGE_SHIFT;
1019                 if (npages < max_pages)
1020                         max_pages = npages;
1021         }
1022
1023         lgp->args.layout.pages = nfs4_alloc_pages(max_pages, gfp_flags);
1024         if (!lgp->args.layout.pages) {
1025                 kfree(lgp);
1026                 return NULL;
1027         }
1028         lgp->args.layout.pglen = max_pages * PAGE_SIZE;
1029         lgp->res.layoutp = &lgp->args.layout;
1030
1031         /* Don't confuse uninitialised result and success */
1032         lgp->res.status = -NFS4ERR_DELAY;
1033
1034         lgp->args.minlength = PAGE_SIZE;
1035         if (lgp->args.minlength > range->length)
1036                 lgp->args.minlength = range->length;
1037         if (ino) {
1038                 loff_t i_size = i_size_read(ino);
1039
1040                 if (range->iomode == IOMODE_READ) {
1041                         if (range->offset >= i_size)
1042                                 lgp->args.minlength = 0;
1043                         else if (i_size - range->offset < lgp->args.minlength)
1044                                 lgp->args.minlength = i_size - range->offset;
1045                 }
1046         }
1047         lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
1048         pnfs_copy_range(&lgp->args.range, range);
1049         lgp->args.type = server->pnfs_curr_ld->id;
1050         lgp->args.inode = ino;
1051         lgp->args.ctx = get_nfs_open_context(ctx);
1052         nfs4_stateid_copy(&lgp->args.stateid, stateid);
1053         lgp->gfp_flags = gfp_flags;
1054         lgp->cred = get_cred(ctx->cred);
1055         return lgp;
1056 }
1057
1058 void pnfs_layoutget_free(struct nfs4_layoutget *lgp)
1059 {
1060         size_t max_pages = lgp->args.layout.pglen / PAGE_SIZE;
1061
1062         nfs4_free_pages(lgp->args.layout.pages, max_pages);
1063         if (lgp->args.inode)
1064                 pnfs_put_layout_hdr(NFS_I(lgp->args.inode)->layout);
1065         put_cred(lgp->cred);
1066         put_nfs_open_context(lgp->args.ctx);
1067         kfree(lgp);
1068 }
1069
1070 static void pnfs_clear_layoutcommit(struct inode *inode,
1071                 struct list_head *head)
1072 {
1073         struct nfs_inode *nfsi = NFS_I(inode);
1074         struct pnfs_layout_segment *lseg, *tmp;
1075
1076         if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
1077                 return;
1078         list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
1079                 if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
1080                         continue;
1081                 pnfs_lseg_dec_and_remove_zero(lseg, head);
1082         }
1083 }
1084
1085 void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
1086                 const nfs4_stateid *arg_stateid,
1087                 const struct pnfs_layout_range *range,
1088                 const nfs4_stateid *stateid)
1089 {
1090         struct inode *inode = lo->plh_inode;
1091         LIST_HEAD(freeme);
1092
1093         spin_lock(&inode->i_lock);
1094         if (!pnfs_layout_is_valid(lo) || !arg_stateid ||
1095             !nfs4_stateid_match_other(&lo->plh_stateid, arg_stateid))
1096                 goto out_unlock;
1097         if (stateid) {
1098                 u32 seq = be32_to_cpu(arg_stateid->seqid);
1099
1100                 pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
1101                 pnfs_free_returned_lsegs(lo, &freeme, range, seq);
1102                 pnfs_set_layout_stateid(lo, stateid, true);
1103         } else
1104                 pnfs_mark_layout_stateid_invalid(lo, &freeme);
1105 out_unlock:
1106         pnfs_clear_layoutreturn_waitbit(lo);
1107         spin_unlock(&inode->i_lock);
1108         pnfs_free_lseg_list(&freeme);
1109
1110 }
1111
1112 static bool
1113 pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo,
1114                 nfs4_stateid *stateid,
1115                 enum pnfs_iomode *iomode)
1116 {
1117         /* Serialise LAYOUTGET/LAYOUTRETURN */
1118         if (atomic_read(&lo->plh_outstanding) != 0)
1119                 return false;
1120         if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
1121                 return false;
1122         set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
1123         pnfs_get_layout_hdr(lo);
1124         if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
1125                 if (stateid != NULL) {
1126                         nfs4_stateid_copy(stateid, &lo->plh_stateid);
1127                         if (lo->plh_return_seq != 0)
1128                                 stateid->seqid = cpu_to_be32(lo->plh_return_seq);
1129                 }
1130                 if (iomode != NULL)
1131                         *iomode = lo->plh_return_iomode;
1132                 pnfs_clear_layoutreturn_info(lo);
1133                 return true;
1134         }
1135         if (stateid != NULL)
1136                 nfs4_stateid_copy(stateid, &lo->plh_stateid);
1137         if (iomode != NULL)
1138                 *iomode = IOMODE_ANY;
1139         return true;
1140 }
1141
1142 static void
1143 pnfs_init_layoutreturn_args(struct nfs4_layoutreturn_args *args,
1144                 struct pnfs_layout_hdr *lo,
1145                 const nfs4_stateid *stateid,
1146                 enum pnfs_iomode iomode)
1147 {
1148         struct inode *inode = lo->plh_inode;
1149
1150         args->layout_type = NFS_SERVER(inode)->pnfs_curr_ld->id;
1151         args->inode = inode;
1152         args->range.iomode = iomode;
1153         args->range.offset = 0;
1154         args->range.length = NFS4_MAX_UINT64;
1155         args->layout = lo;
1156         nfs4_stateid_copy(&args->stateid, stateid);
1157 }
1158
1159 static int
1160 pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo, const nfs4_stateid *stateid,
1161                        enum pnfs_iomode iomode, bool sync)
1162 {
1163         struct inode *ino = lo->plh_inode;
1164         struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1165         struct nfs4_layoutreturn *lrp;
1166         int status = 0;
1167
1168         lrp = kzalloc(sizeof(*lrp), GFP_NOFS);
1169         if (unlikely(lrp == NULL)) {
1170                 status = -ENOMEM;
1171                 spin_lock(&ino->i_lock);
1172                 pnfs_clear_layoutreturn_waitbit(lo);
1173                 spin_unlock(&ino->i_lock);
1174                 pnfs_put_layout_hdr(lo);
1175                 goto out;
1176         }
1177
1178         pnfs_init_layoutreturn_args(&lrp->args, lo, stateid, iomode);
1179         lrp->args.ld_private = &lrp->ld_private;
1180         lrp->clp = NFS_SERVER(ino)->nfs_client;
1181         lrp->cred = lo->plh_lc_cred;
1182         if (ld->prepare_layoutreturn)
1183                 ld->prepare_layoutreturn(&lrp->args);
1184
1185         status = nfs4_proc_layoutreturn(lrp, sync);
1186 out:
1187         dprintk("<-- %s status: %d\n", __func__, status);
1188         return status;
1189 }
1190
1191 /* Return true if layoutreturn is needed */
1192 static bool
1193 pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
1194 {
1195         struct pnfs_layout_segment *s;
1196         enum pnfs_iomode iomode;
1197         u32 seq;
1198
1199         if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1200                 return false;
1201
1202         seq = lo->plh_return_seq;
1203         iomode = lo->plh_return_iomode;
1204
1205         /* Defer layoutreturn until all recalled lsegs are done */
1206         list_for_each_entry(s, &lo->plh_segs, pls_list) {
1207                 if (seq && pnfs_seqid_is_newer(s->pls_seq, seq))
1208                         continue;
1209                 if (iomode != IOMODE_ANY && s->pls_range.iomode != iomode)
1210                         continue;
1211                 if (test_bit(NFS_LSEG_LAYOUTRETURN, &s->pls_flags))
1212                         return false;
1213         }
1214
1215         return true;
1216 }
1217
1218 static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
1219 {
1220         struct inode *inode= lo->plh_inode;
1221
1222         if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1223                 return;
1224         spin_lock(&inode->i_lock);
1225         if (pnfs_layout_need_return(lo)) {
1226                 nfs4_stateid stateid;
1227                 enum pnfs_iomode iomode;
1228                 bool send;
1229
1230                 send = pnfs_prepare_layoutreturn(lo, &stateid, &iomode);
1231                 spin_unlock(&inode->i_lock);
1232                 if (send) {
1233                         /* Send an async layoutreturn so we dont deadlock */
1234                         pnfs_send_layoutreturn(lo, &stateid, iomode, false);
1235                 }
1236         } else
1237                 spin_unlock(&inode->i_lock);
1238 }
1239
1240 /*
1241  * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
1242  * when the layout segment list is empty.
1243  *
1244  * Note that a pnfs_layout_hdr can exist with an empty layout segment
1245  * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
1246  * deviceid is marked invalid.
1247  */
1248 int
1249 _pnfs_return_layout(struct inode *ino)
1250 {
1251         struct pnfs_layout_hdr *lo = NULL;
1252         struct nfs_inode *nfsi = NFS_I(ino);
1253         LIST_HEAD(tmp_list);
1254         nfs4_stateid stateid;
1255         int status = 0;
1256         bool send, valid_layout;
1257
1258         dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
1259
1260         spin_lock(&ino->i_lock);
1261         lo = nfsi->layout;
1262         if (!lo) {
1263                 spin_unlock(&ino->i_lock);
1264                 dprintk("NFS: %s no layout to return\n", __func__);
1265                 goto out;
1266         }
1267         /* Reference matched in nfs4_layoutreturn_release */
1268         pnfs_get_layout_hdr(lo);
1269         /* Is there an outstanding layoutreturn ? */
1270         if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1271                 spin_unlock(&ino->i_lock);
1272                 if (wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1273                                         TASK_UNINTERRUPTIBLE))
1274                         goto out_put_layout_hdr;
1275                 spin_lock(&ino->i_lock);
1276         }
1277         valid_layout = pnfs_layout_is_valid(lo);
1278         pnfs_clear_layoutcommit(ino, &tmp_list);
1279         pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL, 0);
1280
1281         if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) {
1282                 struct pnfs_layout_range range = {
1283                         .iomode         = IOMODE_ANY,
1284                         .offset         = 0,
1285                         .length         = NFS4_MAX_UINT64,
1286                 };
1287                 NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
1288         }
1289
1290         /* Don't send a LAYOUTRETURN if list was initially empty */
1291         if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) ||
1292                         !valid_layout) {
1293                 spin_unlock(&ino->i_lock);
1294                 dprintk("NFS: %s no layout segments to return\n", __func__);
1295                 goto out_put_layout_hdr;
1296         }
1297
1298         send = pnfs_prepare_layoutreturn(lo, &stateid, NULL);
1299         spin_unlock(&ino->i_lock);
1300         if (send)
1301                 status = pnfs_send_layoutreturn(lo, &stateid, IOMODE_ANY, true);
1302 out_put_layout_hdr:
1303         pnfs_free_lseg_list(&tmp_list);
1304         pnfs_put_layout_hdr(lo);
1305 out:
1306         dprintk("<-- %s status: %d\n", __func__, status);
1307         return status;
1308 }
1309
1310 int
1311 pnfs_commit_and_return_layout(struct inode *inode)
1312 {
1313         struct pnfs_layout_hdr *lo;
1314         int ret;
1315
1316         spin_lock(&inode->i_lock);
1317         lo = NFS_I(inode)->layout;
1318         if (lo == NULL) {
1319                 spin_unlock(&inode->i_lock);
1320                 return 0;
1321         }
1322         pnfs_get_layout_hdr(lo);
1323         /* Block new layoutgets and read/write to ds */
1324         lo->plh_block_lgets++;
1325         spin_unlock(&inode->i_lock);
1326         filemap_fdatawait(inode->i_mapping);
1327         ret = pnfs_layoutcommit_inode(inode, true);
1328         if (ret == 0)
1329                 ret = _pnfs_return_layout(inode);
1330         spin_lock(&inode->i_lock);
1331         lo->plh_block_lgets--;
1332         spin_unlock(&inode->i_lock);
1333         pnfs_put_layout_hdr(lo);
1334         return ret;
1335 }
1336
1337 bool pnfs_roc(struct inode *ino,
1338                 struct nfs4_layoutreturn_args *args,
1339                 struct nfs4_layoutreturn_res *res,
1340                 const struct cred *cred)
1341 {
1342         struct nfs_inode *nfsi = NFS_I(ino);
1343         struct nfs_open_context *ctx;
1344         struct nfs4_state *state;
1345         struct pnfs_layout_hdr *lo;
1346         struct pnfs_layout_segment *lseg, *next;
1347         nfs4_stateid stateid;
1348         enum pnfs_iomode iomode = 0;
1349         bool layoutreturn = false, roc = false;
1350         bool skip_read = false;
1351
1352         if (!nfs_have_layout(ino))
1353                 return false;
1354 retry:
1355         rcu_read_lock();
1356         spin_lock(&ino->i_lock);
1357         lo = nfsi->layout;
1358         if (!lo || !pnfs_layout_is_valid(lo) ||
1359             test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1360                 lo = NULL;
1361                 goto out_noroc;
1362         }
1363         pnfs_get_layout_hdr(lo);
1364         if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1365                 spin_unlock(&ino->i_lock);
1366                 rcu_read_unlock();
1367                 wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1368                                 TASK_UNINTERRUPTIBLE);
1369                 pnfs_put_layout_hdr(lo);
1370                 goto retry;
1371         }
1372
1373         /* no roc if we hold a delegation */
1374         if (nfs4_check_delegation(ino, FMODE_READ)) {
1375                 if (nfs4_check_delegation(ino, FMODE_WRITE))
1376                         goto out_noroc;
1377                 skip_read = true;
1378         }
1379
1380         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1381                 state = ctx->state;
1382                 if (state == NULL)
1383                         continue;
1384                 /* Don't return layout if there is open file state */
1385                 if (state->state & FMODE_WRITE)
1386                         goto out_noroc;
1387                 if (state->state & FMODE_READ)
1388                         skip_read = true;
1389         }
1390
1391
1392         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) {
1393                 if (skip_read && lseg->pls_range.iomode == IOMODE_READ)
1394                         continue;
1395                 /* If we are sending layoutreturn, invalidate all valid lsegs */
1396                 if (!test_and_clear_bit(NFS_LSEG_ROC, &lseg->pls_flags))
1397                         continue;
1398                 /*
1399                  * Note: mark lseg for return so pnfs_layout_remove_lseg
1400                  * doesn't invalidate the layout for us.
1401                  */
1402                 set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1403                 if (!mark_lseg_invalid(lseg, &lo->plh_return_segs))
1404                         continue;
1405                 pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
1406         }
1407
1408         if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1409                 goto out_noroc;
1410
1411         /* ROC in two conditions:
1412          * 1. there are ROC lsegs
1413          * 2. we don't send layoutreturn
1414          */
1415         /* lo ref dropped in pnfs_roc_release() */
1416         layoutreturn = pnfs_prepare_layoutreturn(lo, &stateid, &iomode);
1417         /* If the creds don't match, we can't compound the layoutreturn */
1418         if (!layoutreturn || cred != lo->plh_lc_cred)
1419                 goto out_noroc;
1420
1421         roc = layoutreturn;
1422         pnfs_init_layoutreturn_args(args, lo, &stateid, iomode);
1423         res->lrs_present = 0;
1424         layoutreturn = false;
1425
1426 out_noroc:
1427         spin_unlock(&ino->i_lock);
1428         rcu_read_unlock();
1429         pnfs_layoutcommit_inode(ino, true);
1430         if (roc) {
1431                 struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1432                 if (ld->prepare_layoutreturn)
1433                         ld->prepare_layoutreturn(args);
1434                 pnfs_put_layout_hdr(lo);
1435                 return true;
1436         }
1437         if (layoutreturn)
1438                 pnfs_send_layoutreturn(lo, &stateid, iomode, true);
1439         pnfs_put_layout_hdr(lo);
1440         return false;
1441 }
1442
1443 void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
1444                 struct nfs4_layoutreturn_res *res,
1445                 int ret)
1446 {
1447         struct pnfs_layout_hdr *lo = args->layout;
1448         const nfs4_stateid *arg_stateid = NULL;
1449         const nfs4_stateid *res_stateid = NULL;
1450         struct nfs4_xdr_opaque_data *ld_private = args->ld_private;
1451
1452         if (ret == 0) {
1453                 arg_stateid = &args->stateid;
1454                 if (res->lrs_present)
1455                         res_stateid = &res->stateid;
1456         }
1457         pnfs_layoutreturn_free_lsegs(lo, arg_stateid, &args->range,
1458                         res_stateid);
1459         if (ld_private && ld_private->ops && ld_private->ops->free)
1460                 ld_private->ops->free(ld_private);
1461         pnfs_put_layout_hdr(lo);
1462         trace_nfs4_layoutreturn_on_close(args->inode, 0);
1463 }
1464
1465 bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
1466 {
1467         struct nfs_inode *nfsi = NFS_I(ino);
1468         struct pnfs_layout_hdr *lo;
1469         bool sleep = false;
1470
1471         /* we might not have grabbed lo reference. so need to check under
1472          * i_lock */
1473         spin_lock(&ino->i_lock);
1474         lo = nfsi->layout;
1475         if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1476                 rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
1477                 sleep = true;
1478         }
1479         spin_unlock(&ino->i_lock);
1480         return sleep;
1481 }
1482
1483 /*
1484  * Compare two layout segments for sorting into layout cache.
1485  * We want to preferentially return RW over RO layouts, so ensure those
1486  * are seen first.
1487  */
1488 static s64
1489 pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1490            const struct pnfs_layout_range *l2)
1491 {
1492         s64 d;
1493
1494         /* high offset > low offset */
1495         d = l1->offset - l2->offset;
1496         if (d)
1497                 return d;
1498
1499         /* short length > long length */
1500         d = l2->length - l1->length;
1501         if (d)
1502                 return d;
1503
1504         /* read > read/write */
1505         return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1506 }
1507
1508 static bool
1509 pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1510                 const struct pnfs_layout_range *l2)
1511 {
1512         return pnfs_lseg_range_cmp(l1, l2) > 0;
1513 }
1514
1515 static bool
1516 pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1517                 struct pnfs_layout_segment *old)
1518 {
1519         return false;
1520 }
1521
1522 void
1523 pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1524                    struct pnfs_layout_segment *lseg,
1525                    bool (*is_after)(const struct pnfs_layout_range *,
1526                            const struct pnfs_layout_range *),
1527                    bool (*do_merge)(struct pnfs_layout_segment *,
1528                            struct pnfs_layout_segment *),
1529                    struct list_head *free_me)
1530 {
1531         struct pnfs_layout_segment *lp, *tmp;
1532
1533         dprintk("%s:Begin\n", __func__);
1534
1535         list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1536                 if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1537                         continue;
1538                 if (do_merge(lseg, lp)) {
1539                         mark_lseg_invalid(lp, free_me);
1540                         continue;
1541                 }
1542                 if (is_after(&lseg->pls_range, &lp->pls_range))
1543                         continue;
1544                 list_add_tail(&lseg->pls_list, &lp->pls_list);
1545                 dprintk("%s: inserted lseg %p "
1546                         "iomode %d offset %llu length %llu before "
1547                         "lp %p iomode %d offset %llu length %llu\n",
1548                         __func__, lseg, lseg->pls_range.iomode,
1549                         lseg->pls_range.offset, lseg->pls_range.length,
1550                         lp, lp->pls_range.iomode, lp->pls_range.offset,
1551                         lp->pls_range.length);
1552                 goto out;
1553         }
1554         list_add_tail(&lseg->pls_list, &lo->plh_segs);
1555         dprintk("%s: inserted lseg %p "
1556                 "iomode %d offset %llu length %llu at tail\n",
1557                 __func__, lseg, lseg->pls_range.iomode,
1558                 lseg->pls_range.offset, lseg->pls_range.length);
1559 out:
1560         pnfs_get_layout_hdr(lo);
1561
1562         dprintk("%s:Return\n", __func__);
1563 }
1564 EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1565
1566 static void
1567 pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1568                    struct pnfs_layout_segment *lseg,
1569                    struct list_head *free_me)
1570 {
1571         struct inode *inode = lo->plh_inode;
1572         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1573
1574         if (ld->add_lseg != NULL)
1575                 ld->add_lseg(lo, lseg, free_me);
1576         else
1577                 pnfs_generic_layout_insert_lseg(lo, lseg,
1578                                 pnfs_lseg_range_is_after,
1579                                 pnfs_lseg_no_merge,
1580                                 free_me);
1581 }
1582
1583 static struct pnfs_layout_hdr *
1584 alloc_init_layout_hdr(struct inode *ino,
1585                       struct nfs_open_context *ctx,
1586                       gfp_t gfp_flags)
1587 {
1588         struct pnfs_layout_hdr *lo;
1589
1590         lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1591         if (!lo)
1592                 return NULL;
1593         refcount_set(&lo->plh_refcount, 1);
1594         INIT_LIST_HEAD(&lo->plh_layouts);
1595         INIT_LIST_HEAD(&lo->plh_segs);
1596         INIT_LIST_HEAD(&lo->plh_return_segs);
1597         INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1598         lo->plh_inode = ino;
1599         lo->plh_lc_cred = get_cred(ctx->cred);
1600         lo->plh_flags |= 1 << NFS_LAYOUT_INVALID_STID;
1601         return lo;
1602 }
1603
1604 static struct pnfs_layout_hdr *
1605 pnfs_find_alloc_layout(struct inode *ino,
1606                        struct nfs_open_context *ctx,
1607                        gfp_t gfp_flags)
1608         __releases(&ino->i_lock)
1609         __acquires(&ino->i_lock)
1610 {
1611         struct nfs_inode *nfsi = NFS_I(ino);
1612         struct pnfs_layout_hdr *new = NULL;
1613
1614         dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1615
1616         if (nfsi->layout != NULL)
1617                 goto out_existing;
1618         spin_unlock(&ino->i_lock);
1619         new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1620         spin_lock(&ino->i_lock);
1621
1622         if (likely(nfsi->layout == NULL)) {     /* Won the race? */
1623                 nfsi->layout = new;
1624                 return new;
1625         } else if (new != NULL)
1626                 pnfs_free_layout_hdr(new);
1627 out_existing:
1628         pnfs_get_layout_hdr(nfsi->layout);
1629         return nfsi->layout;
1630 }
1631
1632 /*
1633  * iomode matching rules:
1634  * iomode       lseg    strict match
1635  *                      iomode
1636  * -----        -----   ------ -----
1637  * ANY          READ    N/A    true
1638  * ANY          RW      N/A    true
1639  * RW           READ    N/A    false
1640  * RW           RW      N/A    true
1641  * READ         READ    N/A    true
1642  * READ         RW      true   false
1643  * READ         RW      false  true
1644  */
1645 static bool
1646 pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1647                  const struct pnfs_layout_range *range,
1648                  bool strict_iomode)
1649 {
1650         struct pnfs_layout_range range1;
1651
1652         if ((range->iomode == IOMODE_RW &&
1653              ls_range->iomode != IOMODE_RW) ||
1654             (range->iomode != ls_range->iomode &&
1655              strict_iomode) ||
1656             !pnfs_lseg_range_intersecting(ls_range, range))
1657                 return false;
1658
1659         /* range1 covers only the first byte in the range */
1660         range1 = *range;
1661         range1.length = 1;
1662         return pnfs_lseg_range_contained(ls_range, &range1);
1663 }
1664
1665 /*
1666  * lookup range in layout
1667  */
1668 static struct pnfs_layout_segment *
1669 pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1670                 struct pnfs_layout_range *range,
1671                 bool strict_iomode)
1672 {
1673         struct pnfs_layout_segment *lseg, *ret = NULL;
1674
1675         dprintk("%s:Begin\n", __func__);
1676
1677         list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1678                 if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1679                     pnfs_lseg_range_match(&lseg->pls_range, range,
1680                                           strict_iomode)) {
1681                         ret = pnfs_get_lseg(lseg);
1682                         break;
1683                 }
1684         }
1685
1686         dprintk("%s:Return lseg %p ref %d\n",
1687                 __func__, ret, ret ? refcount_read(&ret->pls_refcount) : 0);
1688         return ret;
1689 }
1690
1691 /*
1692  * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1693  * to the MDS or over pNFS
1694  *
1695  * The nfs_inode read_io and write_io fields are cumulative counters reset
1696  * when there are no layout segments. Note that in pnfs_update_layout iomode
1697  * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1698  * WRITE request.
1699  *
1700  * A return of true means use MDS I/O.
1701  *
1702  * From rfc 5661:
1703  * If a file's size is smaller than the file size threshold, data accesses
1704  * SHOULD be sent to the metadata server.  If an I/O request has a length that
1705  * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1706  * server.  If both file size and I/O size are provided, the client SHOULD
1707  * reach or exceed  both thresholds before sending its read or write
1708  * requests to the data server.
1709  */
1710 static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1711                                      struct inode *ino, int iomode)
1712 {
1713         struct nfs4_threshold *t = ctx->mdsthreshold;
1714         struct nfs_inode *nfsi = NFS_I(ino);
1715         loff_t fsize = i_size_read(ino);
1716         bool size = false, size_set = false, io = false, io_set = false, ret = false;
1717
1718         if (t == NULL)
1719                 return ret;
1720
1721         dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1722                 __func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1723
1724         switch (iomode) {
1725         case IOMODE_READ:
1726                 if (t->bm & THRESHOLD_RD) {
1727                         dprintk("%s fsize %llu\n", __func__, fsize);
1728                         size_set = true;
1729                         if (fsize < t->rd_sz)
1730                                 size = true;
1731                 }
1732                 if (t->bm & THRESHOLD_RD_IO) {
1733                         dprintk("%s nfsi->read_io %llu\n", __func__,
1734                                 nfsi->read_io);
1735                         io_set = true;
1736                         if (nfsi->read_io < t->rd_io_sz)
1737                                 io = true;
1738                 }
1739                 break;
1740         case IOMODE_RW:
1741                 if (t->bm & THRESHOLD_WR) {
1742                         dprintk("%s fsize %llu\n", __func__, fsize);
1743                         size_set = true;
1744                         if (fsize < t->wr_sz)
1745                                 size = true;
1746                 }
1747                 if (t->bm & THRESHOLD_WR_IO) {
1748                         dprintk("%s nfsi->write_io %llu\n", __func__,
1749                                 nfsi->write_io);
1750                         io_set = true;
1751                         if (nfsi->write_io < t->wr_io_sz)
1752                                 io = true;
1753                 }
1754                 break;
1755         }
1756         if (size_set && io_set) {
1757                 if (size && io)
1758                         ret = true;
1759         } else if (size || io)
1760                 ret = true;
1761
1762         dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1763         return ret;
1764 }
1765
1766 static int pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
1767 {
1768         /*
1769          * send layoutcommit as it can hold up layoutreturn due to lseg
1770          * reference
1771          */
1772         pnfs_layoutcommit_inode(lo->plh_inode, false);
1773         return wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
1774                                    nfs_wait_bit_killable,
1775                                    TASK_KILLABLE);
1776 }
1777
1778 static void nfs_layoutget_begin(struct pnfs_layout_hdr *lo)
1779 {
1780         atomic_inc(&lo->plh_outstanding);
1781 }
1782
1783 static void nfs_layoutget_end(struct pnfs_layout_hdr *lo)
1784 {
1785         if (atomic_dec_and_test(&lo->plh_outstanding))
1786                 wake_up_var(&lo->plh_outstanding);
1787 }
1788
1789 static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
1790 {
1791         unsigned long *bitlock = &lo->plh_flags;
1792
1793         clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
1794         smp_mb__after_atomic();
1795         wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
1796 }
1797
1798 static void _add_to_server_list(struct pnfs_layout_hdr *lo,
1799                                 struct nfs_server *server)
1800 {
1801         if (list_empty(&lo->plh_layouts)) {
1802                 struct nfs_client *clp = server->nfs_client;
1803
1804                 /* The lo must be on the clp list if there is any
1805                  * chance of a CB_LAYOUTRECALL(FILE) coming in.
1806                  */
1807                 spin_lock(&clp->cl_lock);
1808                 if (list_empty(&lo->plh_layouts))
1809                         list_add_tail(&lo->plh_layouts, &server->layouts);
1810                 spin_unlock(&clp->cl_lock);
1811         }
1812 }
1813
1814 /*
1815  * Layout segment is retreived from the server if not cached.
1816  * The appropriate layout segment is referenced and returned to the caller.
1817  */
1818 struct pnfs_layout_segment *
1819 pnfs_update_layout(struct inode *ino,
1820                    struct nfs_open_context *ctx,
1821                    loff_t pos,
1822                    u64 count,
1823                    enum pnfs_iomode iomode,
1824                    bool strict_iomode,
1825                    gfp_t gfp_flags)
1826 {
1827         struct pnfs_layout_range arg = {
1828                 .iomode = iomode,
1829                 .offset = pos,
1830                 .length = count,
1831         };
1832         unsigned pg_offset;
1833         struct nfs_server *server = NFS_SERVER(ino);
1834         struct nfs_client *clp = server->nfs_client;
1835         struct pnfs_layout_hdr *lo = NULL;
1836         struct pnfs_layout_segment *lseg = NULL;
1837         struct nfs4_layoutget *lgp;
1838         nfs4_stateid stateid;
1839         long timeout = 0;
1840         unsigned long giveup = jiffies + (clp->cl_lease_time << 1);
1841         bool first;
1842
1843         if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
1844                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1845                                  PNFS_UPDATE_LAYOUT_NO_PNFS);
1846                 goto out;
1847         }
1848
1849         if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
1850                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1851                                  PNFS_UPDATE_LAYOUT_MDSTHRESH);
1852                 goto out;
1853         }
1854
1855 lookup_again:
1856         lseg = ERR_PTR(nfs4_client_recover_expired_lease(clp));
1857         if (IS_ERR(lseg))
1858                 goto out;
1859         first = false;
1860         spin_lock(&ino->i_lock);
1861         lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
1862         if (lo == NULL) {
1863                 spin_unlock(&ino->i_lock);
1864                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1865                                  PNFS_UPDATE_LAYOUT_NOMEM);
1866                 goto out;
1867         }
1868
1869         /* Do we even need to bother with this? */
1870         if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1871                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1872                                  PNFS_UPDATE_LAYOUT_BULK_RECALL);
1873                 dprintk("%s matches recall, use MDS\n", __func__);
1874                 goto out_unlock;
1875         }
1876
1877         /* if LAYOUTGET already failed once we don't try again */
1878         if (pnfs_layout_io_test_failed(lo, iomode)) {
1879                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1880                                  PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
1881                 goto out_unlock;
1882         }
1883
1884         /*
1885          * If the layout segment list is empty, but there are outstanding
1886          * layoutget calls, then they might be subject to a layoutrecall.
1887          */
1888         if (list_empty(&lo->plh_segs) &&
1889             atomic_read(&lo->plh_outstanding) != 0) {
1890                 spin_unlock(&ino->i_lock);
1891                 lseg = ERR_PTR(wait_var_event_killable(&lo->plh_outstanding,
1892                                         !atomic_read(&lo->plh_outstanding)));
1893                 if (IS_ERR(lseg))
1894                         goto out_put_layout_hdr;
1895                 pnfs_put_layout_hdr(lo);
1896                 goto lookup_again;
1897         }
1898
1899         lseg = pnfs_find_lseg(lo, &arg, strict_iomode);
1900         if (lseg) {
1901                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1902                                 PNFS_UPDATE_LAYOUT_FOUND_CACHED);
1903                 goto out_unlock;
1904         }
1905
1906         if (!nfs4_valid_open_stateid(ctx->state)) {
1907                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1908                                 PNFS_UPDATE_LAYOUT_INVALID_OPEN);
1909                 goto out_unlock;
1910         }
1911
1912         /*
1913          * Choose a stateid for the LAYOUTGET. If we don't have a layout
1914          * stateid, or it has been invalidated, then we must use the open
1915          * stateid.
1916          */
1917         if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
1918                 int status;
1919
1920                 /*
1921                  * The first layoutget for the file. Need to serialize per
1922                  * RFC 5661 Errata 3208.
1923                  */
1924                 if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
1925                                      &lo->plh_flags)) {
1926                         spin_unlock(&ino->i_lock);
1927                         lseg = ERR_PTR(wait_on_bit(&lo->plh_flags,
1928                                                 NFS_LAYOUT_FIRST_LAYOUTGET,
1929                                                 TASK_KILLABLE));
1930                         if (IS_ERR(lseg))
1931                                 goto out_put_layout_hdr;
1932                         pnfs_put_layout_hdr(lo);
1933                         dprintk("%s retrying\n", __func__);
1934                         goto lookup_again;
1935                 }
1936
1937                 first = true;
1938                 status = nfs4_select_rw_stateid(ctx->state,
1939                                         iomode == IOMODE_RW ? FMODE_WRITE : FMODE_READ,
1940                                         NULL, &stateid, NULL);
1941                 if (status != 0) {
1942                         trace_pnfs_update_layout(ino, pos, count,
1943                                         iomode, lo, lseg,
1944                                         PNFS_UPDATE_LAYOUT_INVALID_OPEN);
1945                         if (status != -EAGAIN)
1946                                 goto out_unlock;
1947                         spin_unlock(&ino->i_lock);
1948                         nfs4_schedule_stateid_recovery(server, ctx->state);
1949                         pnfs_clear_first_layoutget(lo);
1950                         pnfs_put_layout_hdr(lo);
1951                         goto lookup_again;
1952                 }
1953         } else {
1954                 nfs4_stateid_copy(&stateid, &lo->plh_stateid);
1955         }
1956
1957         /*
1958          * Because we free lsegs before sending LAYOUTRETURN, we need to wait
1959          * for LAYOUTRETURN even if first is true.
1960          */
1961         if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1962                 spin_unlock(&ino->i_lock);
1963                 dprintk("%s wait for layoutreturn\n", __func__);
1964                 lseg = ERR_PTR(pnfs_prepare_to_retry_layoutget(lo));
1965                 if (!IS_ERR(lseg)) {
1966                         if (first)
1967                                 pnfs_clear_first_layoutget(lo);
1968                         pnfs_put_layout_hdr(lo);
1969                         dprintk("%s retrying\n", __func__);
1970                         trace_pnfs_update_layout(ino, pos, count, iomode, lo,
1971                                         lseg, PNFS_UPDATE_LAYOUT_RETRY);
1972                         goto lookup_again;
1973                 }
1974                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1975                                 PNFS_UPDATE_LAYOUT_RETURN);
1976                 goto out_put_layout_hdr;
1977         }
1978
1979         if (pnfs_layoutgets_blocked(lo)) {
1980                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1981                                 PNFS_UPDATE_LAYOUT_BLOCKED);
1982                 goto out_unlock;
1983         }
1984         nfs_layoutget_begin(lo);
1985         spin_unlock(&ino->i_lock);
1986
1987         _add_to_server_list(lo, server);
1988
1989         pg_offset = arg.offset & ~PAGE_MASK;
1990         if (pg_offset) {
1991                 arg.offset -= pg_offset;
1992                 arg.length += pg_offset;
1993         }
1994         if (arg.length != NFS4_MAX_UINT64)
1995                 arg.length = PAGE_ALIGN(arg.length);
1996
1997         lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &stateid, &arg, gfp_flags);
1998         if (!lgp) {
1999                 trace_pnfs_update_layout(ino, pos, count, iomode, lo, NULL,
2000                                          PNFS_UPDATE_LAYOUT_NOMEM);
2001                 nfs_layoutget_end(lo);
2002                 goto out_put_layout_hdr;
2003         }
2004
2005         lseg = nfs4_proc_layoutget(lgp, &timeout);
2006         trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2007                                  PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
2008         nfs_layoutget_end(lo);
2009         if (IS_ERR(lseg)) {
2010                 switch(PTR_ERR(lseg)) {
2011                 case -EBUSY:
2012                         if (time_after(jiffies, giveup))
2013                                 lseg = NULL;
2014                         break;
2015                 case -ERECALLCONFLICT:
2016                 case -EAGAIN:
2017                         break;
2018                 default:
2019                         if (!nfs_error_is_fatal(PTR_ERR(lseg))) {
2020                                 pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2021                                 lseg = NULL;
2022                         }
2023                         goto out_put_layout_hdr;
2024                 }
2025                 if (lseg) {
2026                         if (first)
2027                                 pnfs_clear_first_layoutget(lo);
2028                         trace_pnfs_update_layout(ino, pos, count,
2029                                 iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
2030                         pnfs_put_layout_hdr(lo);
2031                         goto lookup_again;
2032                 }
2033         } else {
2034                 pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2035         }
2036
2037 out_put_layout_hdr:
2038         if (first)
2039                 pnfs_clear_first_layoutget(lo);
2040         trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2041                                  PNFS_UPDATE_LAYOUT_EXIT);
2042         pnfs_put_layout_hdr(lo);
2043 out:
2044         dprintk("%s: inode %s/%llu pNFS layout segment %s for "
2045                         "(%s, offset: %llu, length: %llu)\n",
2046                         __func__, ino->i_sb->s_id,
2047                         (unsigned long long)NFS_FILEID(ino),
2048                         IS_ERR_OR_NULL(lseg) ? "not found" : "found",
2049                         iomode==IOMODE_RW ?  "read/write" : "read-only",
2050                         (unsigned long long)pos,
2051                         (unsigned long long)count);
2052         return lseg;
2053 out_unlock:
2054         spin_unlock(&ino->i_lock);
2055         goto out_put_layout_hdr;
2056 }
2057 EXPORT_SYMBOL_GPL(pnfs_update_layout);
2058
2059 static bool
2060 pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
2061 {
2062         switch (range->iomode) {
2063         case IOMODE_READ:
2064         case IOMODE_RW:
2065                 break;
2066         default:
2067                 return false;
2068         }
2069         if (range->offset == NFS4_MAX_UINT64)
2070                 return false;
2071         if (range->length == 0)
2072                 return false;
2073         if (range->length != NFS4_MAX_UINT64 &&
2074             range->length > NFS4_MAX_UINT64 - range->offset)
2075                 return false;
2076         return true;
2077 }
2078
2079 static struct pnfs_layout_hdr *
2080 _pnfs_grab_empty_layout(struct inode *ino, struct nfs_open_context *ctx)
2081 {
2082         struct pnfs_layout_hdr *lo;
2083
2084         spin_lock(&ino->i_lock);
2085         lo = pnfs_find_alloc_layout(ino, ctx, GFP_KERNEL);
2086         if (!lo)
2087                 goto out_unlock;
2088         if (!test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
2089                 goto out_unlock;
2090         if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
2091                 goto out_unlock;
2092         if (pnfs_layoutgets_blocked(lo))
2093                 goto out_unlock;
2094         if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags))
2095                 goto out_unlock;
2096         nfs_layoutget_begin(lo);
2097         spin_unlock(&ino->i_lock);
2098         _add_to_server_list(lo, NFS_SERVER(ino));
2099         return lo;
2100
2101 out_unlock:
2102         spin_unlock(&ino->i_lock);
2103         pnfs_put_layout_hdr(lo);
2104         return NULL;
2105 }
2106
2107 extern const nfs4_stateid current_stateid;
2108
2109 static void _lgopen_prepare_attached(struct nfs4_opendata *data,
2110                                      struct nfs_open_context *ctx)
2111 {
2112         struct inode *ino = data->dentry->d_inode;
2113         struct pnfs_layout_range rng = {
2114                 .iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2115                           IOMODE_RW: IOMODE_READ,
2116                 .offset = 0,
2117                 .length = NFS4_MAX_UINT64,
2118         };
2119         struct nfs4_layoutget *lgp;
2120         struct pnfs_layout_hdr *lo;
2121
2122         /* Heuristic: don't send layoutget if we have cached data */
2123         if (rng.iomode == IOMODE_READ &&
2124            (i_size_read(ino) == 0 || ino->i_mapping->nrpages != 0))
2125                 return;
2126
2127         lo = _pnfs_grab_empty_layout(ino, ctx);
2128         if (!lo)
2129                 return;
2130         lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid,
2131                                              &rng, GFP_KERNEL);
2132         if (!lgp) {
2133                 pnfs_clear_first_layoutget(lo);
2134                 pnfs_put_layout_hdr(lo);
2135                 return;
2136         }
2137         data->lgp = lgp;
2138         data->o_arg.lg_args = &lgp->args;
2139         data->o_res.lg_res = &lgp->res;
2140 }
2141
2142 static void _lgopen_prepare_floating(struct nfs4_opendata *data,
2143                                      struct nfs_open_context *ctx)
2144 {
2145         struct pnfs_layout_range rng = {
2146                 .iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2147                           IOMODE_RW: IOMODE_READ,
2148                 .offset = 0,
2149                 .length = NFS4_MAX_UINT64,
2150         };
2151         struct nfs4_layoutget *lgp;
2152
2153         lgp = pnfs_alloc_init_layoutget_args(NULL, ctx, &current_stateid,
2154                                              &rng, GFP_KERNEL);
2155         if (!lgp)
2156                 return;
2157         data->lgp = lgp;
2158         data->o_arg.lg_args = &lgp->args;
2159         data->o_res.lg_res = &lgp->res;
2160 }
2161
2162 void pnfs_lgopen_prepare(struct nfs4_opendata *data,
2163                          struct nfs_open_context *ctx)
2164 {
2165         struct nfs_server *server = NFS_SERVER(data->dir->d_inode);
2166
2167         if (!(pnfs_enabled_sb(server) &&
2168               server->pnfs_curr_ld->flags & PNFS_LAYOUTGET_ON_OPEN))
2169                 return;
2170         /* Could check on max_ops, but currently hardcoded high enough */
2171         if (!nfs_server_capable(data->dir->d_inode, NFS_CAP_LGOPEN))
2172                 return;
2173         if (data->state)
2174                 _lgopen_prepare_attached(data, ctx);
2175         else
2176                 _lgopen_prepare_floating(data, ctx);
2177 }
2178
2179 void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
2180                        struct nfs_open_context *ctx)
2181 {
2182         struct pnfs_layout_hdr *lo;
2183         struct pnfs_layout_segment *lseg;
2184         struct nfs_server *srv = NFS_SERVER(ino);
2185         u32 iomode;
2186
2187         if (!lgp)
2188                 return;
2189         dprintk("%s: entered with status %i\n", __func__, lgp->res.status);
2190         if (lgp->res.status) {
2191                 switch (lgp->res.status) {
2192                 default:
2193                         break;
2194                 /*
2195                  * Halt lgopen attempts if the server doesn't recognise
2196                  * the "current stateid" value, the layout type, or the
2197                  * layoutget operation as being valid.
2198                  * Also if it complains about too many ops in the compound
2199                  * or of the request/reply being too big.
2200                  */
2201                 case -NFS4ERR_BAD_STATEID:
2202                 case -NFS4ERR_NOTSUPP:
2203                 case -NFS4ERR_REP_TOO_BIG:
2204                 case -NFS4ERR_REP_TOO_BIG_TO_CACHE:
2205                 case -NFS4ERR_REQ_TOO_BIG:
2206                 case -NFS4ERR_TOO_MANY_OPS:
2207                 case -NFS4ERR_UNKNOWN_LAYOUTTYPE:
2208                         srv->caps &= ~NFS_CAP_LGOPEN;
2209                 }
2210                 return;
2211         }
2212         if (!lgp->args.inode) {
2213                 lo = _pnfs_grab_empty_layout(ino, ctx);
2214                 if (!lo)
2215                         return;
2216                 lgp->args.inode = ino;
2217         } else
2218                 lo = NFS_I(lgp->args.inode)->layout;
2219
2220         lseg = pnfs_layout_process(lgp);
2221         if (!IS_ERR(lseg)) {
2222                 iomode = lgp->args.range.iomode;
2223                 pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2224                 pnfs_put_lseg(lseg);
2225         }
2226 }
2227
2228 void nfs4_lgopen_release(struct nfs4_layoutget *lgp)
2229 {
2230         if (lgp != NULL) {
2231                 struct inode *inode = lgp->args.inode;
2232                 if (inode) {
2233                         struct pnfs_layout_hdr *lo = NFS_I(inode)->layout;
2234                         pnfs_clear_first_layoutget(lo);
2235                         nfs_layoutget_end(lo);
2236                 }
2237                 pnfs_layoutget_free(lgp);
2238         }
2239 }
2240
2241 struct pnfs_layout_segment *
2242 pnfs_layout_process(struct nfs4_layoutget *lgp)
2243 {
2244         struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
2245         struct nfs4_layoutget_res *res = &lgp->res;
2246         struct pnfs_layout_segment *lseg;
2247         struct inode *ino = lo->plh_inode;
2248         LIST_HEAD(free_me);
2249
2250         if (!pnfs_sanity_check_layout_range(&res->range))
2251                 return ERR_PTR(-EINVAL);
2252
2253         /* Inject layout blob into I/O device driver */
2254         lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
2255         if (IS_ERR_OR_NULL(lseg)) {
2256                 if (!lseg)
2257                         lseg = ERR_PTR(-ENOMEM);
2258
2259                 dprintk("%s: Could not allocate layout: error %ld\n",
2260                        __func__, PTR_ERR(lseg));
2261                 return lseg;
2262         }
2263
2264         pnfs_init_lseg(lo, lseg, &res->range, &res->stateid);
2265
2266         spin_lock(&ino->i_lock);
2267         if (pnfs_layoutgets_blocked(lo)) {
2268                 dprintk("%s forget reply due to state\n", __func__);
2269                 goto out_forget;
2270         }
2271
2272         if (!pnfs_layout_is_valid(lo)) {
2273                 /* We have a completely new layout */
2274                 pnfs_set_layout_stateid(lo, &res->stateid, true);
2275         } else if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
2276                 /* existing state ID, make sure the sequence number matches. */
2277                 if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
2278                         dprintk("%s forget reply due to sequence\n", __func__);
2279                         goto out_forget;
2280                 }
2281                 pnfs_set_layout_stateid(lo, &res->stateid, false);
2282         } else {
2283                 /*
2284                  * We got an entirely new state ID.  Mark all segments for the
2285                  * inode invalid, and retry the layoutget
2286                  */
2287                 pnfs_mark_layout_stateid_invalid(lo, &free_me);
2288                 goto out_forget;
2289         }
2290
2291         pnfs_get_lseg(lseg);
2292         pnfs_layout_insert_lseg(lo, lseg, &free_me);
2293
2294
2295         if (res->return_on_close)
2296                 set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
2297
2298         spin_unlock(&ino->i_lock);
2299         pnfs_free_lseg_list(&free_me);
2300         return lseg;
2301
2302 out_forget:
2303         spin_unlock(&ino->i_lock);
2304         lseg->pls_layout = lo;
2305         NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
2306         return ERR_PTR(-EAGAIN);
2307 }
2308
2309 static int
2310 mark_lseg_invalid_or_return(struct pnfs_layout_segment *lseg,
2311                 struct list_head *tmp_list)
2312 {
2313         if (!mark_lseg_invalid(lseg, tmp_list))
2314                 return 0;
2315         pnfs_cache_lseg_for_layoutreturn(lseg->pls_layout, lseg);
2316         return 1;
2317 }
2318
2319 /**
2320  * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
2321  * @lo: pointer to layout header
2322  * @tmp_list: list header to be used with pnfs_free_lseg_list()
2323  * @return_range: describe layout segment ranges to be returned
2324  * @seq: stateid seqid to match
2325  *
2326  * This function is mainly intended for use by layoutrecall. It attempts
2327  * to free the layout segment immediately, or else to mark it for return
2328  * as soon as its reference count drops to zero.
2329  *
2330  * Returns
2331  * - 0: a layoutreturn needs to be scheduled.
2332  * - EBUSY: there are layout segment that are still in use.
2333  * - ENOENT: there are no layout segments that need to be returned.
2334  */
2335 int
2336 pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
2337                                 struct list_head *tmp_list,
2338                                 const struct pnfs_layout_range *return_range,
2339                                 u32 seq)
2340 {
2341         struct pnfs_layout_segment *lseg, *next;
2342         int remaining = 0;
2343
2344         dprintk("%s:Begin lo %p\n", __func__, lo);
2345
2346         assert_spin_locked(&lo->plh_inode->i_lock);
2347
2348         list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
2349                 if (pnfs_match_lseg_recall(lseg, return_range, seq)) {
2350                         dprintk("%s: marking lseg %p iomode %d "
2351                                 "offset %llu length %llu\n", __func__,
2352                                 lseg, lseg->pls_range.iomode,
2353                                 lseg->pls_range.offset,
2354                                 lseg->pls_range.length);
2355                         if (mark_lseg_invalid_or_return(lseg, tmp_list))
2356                                 continue;
2357                         remaining++;
2358                         set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
2359                 }
2360
2361         if (remaining) {
2362                 pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2363                 return -EBUSY;
2364         }
2365
2366         if (!list_empty(&lo->plh_return_segs)) {
2367                 pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2368                 return 0;
2369         }
2370
2371         return -ENOENT;
2372 }
2373
2374 void pnfs_error_mark_layout_for_return(struct inode *inode,
2375                                        struct pnfs_layout_segment *lseg)
2376 {
2377         struct pnfs_layout_hdr *lo = NFS_I(inode)->layout;
2378         struct pnfs_layout_range range = {
2379                 .iomode = lseg->pls_range.iomode,
2380                 .offset = 0,
2381                 .length = NFS4_MAX_UINT64,
2382         };
2383         bool return_now = false;
2384
2385         spin_lock(&inode->i_lock);
2386         if (!pnfs_layout_is_valid(lo)) {
2387                 spin_unlock(&inode->i_lock);
2388                 return;
2389         }
2390         pnfs_set_plh_return_info(lo, range.iomode, 0);
2391         /*
2392          * mark all matching lsegs so that we are sure to have no live
2393          * segments at hand when sending layoutreturn. See pnfs_put_lseg()
2394          * for how it works.
2395          */
2396         if (pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs, &range, 0) != -EBUSY) {
2397                 nfs4_stateid stateid;
2398                 enum pnfs_iomode iomode;
2399
2400                 return_now = pnfs_prepare_layoutreturn(lo, &stateid, &iomode);
2401                 spin_unlock(&inode->i_lock);
2402                 if (return_now)
2403                         pnfs_send_layoutreturn(lo, &stateid, iomode, false);
2404         } else {
2405                 spin_unlock(&inode->i_lock);
2406                 nfs_commit_inode(inode, 0);
2407         }
2408 }
2409 EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
2410
2411 void
2412 pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor *pgio)
2413 {
2414         if (pgio->pg_lseg == NULL ||
2415             test_bit(NFS_LSEG_VALID, &pgio->pg_lseg->pls_flags))
2416                 return;
2417         pnfs_put_lseg(pgio->pg_lseg);
2418         pgio->pg_lseg = NULL;
2419 }
2420 EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_layout);
2421
2422 /*
2423  * Check for any intersection between the request and the pgio->pg_lseg,
2424  * and if none, put this pgio->pg_lseg away.
2425  */
2426 static void
2427 pnfs_generic_pg_check_range(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2428 {
2429         if (pgio->pg_lseg && !pnfs_lseg_request_intersecting(pgio->pg_lseg, req)) {
2430                 pnfs_put_lseg(pgio->pg_lseg);
2431                 pgio->pg_lseg = NULL;
2432         }
2433 }
2434
2435 void
2436 pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2437 {
2438         u64 rd_size = req->wb_bytes;
2439
2440         pnfs_generic_pg_check_layout(pgio);
2441         pnfs_generic_pg_check_range(pgio, req);
2442         if (pgio->pg_lseg == NULL) {
2443                 if (pgio->pg_dreq == NULL)
2444                         rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
2445                 else
2446                         rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
2447
2448                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
2449                                                    nfs_req_openctx(req),
2450                                                    req_offset(req),
2451                                                    rd_size,
2452                                                    IOMODE_READ,
2453                                                    false,
2454                                                    GFP_KERNEL);
2455                 if (IS_ERR(pgio->pg_lseg)) {
2456                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2457                         pgio->pg_lseg = NULL;
2458                         return;
2459                 }
2460         }
2461         /* If no lseg, fall back to read through mds */
2462         if (pgio->pg_lseg == NULL)
2463                 nfs_pageio_reset_read_mds(pgio);
2464
2465 }
2466 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
2467
2468 void
2469 pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
2470                            struct nfs_page *req, u64 wb_size)
2471 {
2472         pnfs_generic_pg_check_layout(pgio);
2473         pnfs_generic_pg_check_range(pgio, req);
2474         if (pgio->pg_lseg == NULL) {
2475                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
2476                                                    nfs_req_openctx(req),
2477                                                    req_offset(req),
2478                                                    wb_size,
2479                                                    IOMODE_RW,
2480                                                    false,
2481                                                    GFP_KERNEL);
2482                 if (IS_ERR(pgio->pg_lseg)) {
2483                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2484                         pgio->pg_lseg = NULL;
2485                         return;
2486                 }
2487         }
2488         /* If no lseg, fall back to write through mds */
2489         if (pgio->pg_lseg == NULL)
2490                 nfs_pageio_reset_write_mds(pgio);
2491 }
2492 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
2493
2494 void
2495 pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
2496 {
2497         if (desc->pg_lseg) {
2498                 pnfs_put_lseg(desc->pg_lseg);
2499                 desc->pg_lseg = NULL;
2500         }
2501 }
2502 EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
2503
2504 /*
2505  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
2506  * of bytes (maximum @req->wb_bytes) that can be coalesced.
2507  */
2508 size_t
2509 pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
2510                      struct nfs_page *prev, struct nfs_page *req)
2511 {
2512         unsigned int size;
2513         u64 seg_end, req_start, seg_left;
2514
2515         size = nfs_generic_pg_test(pgio, prev, req);
2516         if (!size)
2517                 return 0;
2518
2519         /*
2520          * 'size' contains the number of bytes left in the current page (up
2521          * to the original size asked for in @req->wb_bytes).
2522          *
2523          * Calculate how many bytes are left in the layout segment
2524          * and if there are less bytes than 'size', return that instead.
2525          *
2526          * Please also note that 'end_offset' is actually the offset of the
2527          * first byte that lies outside the pnfs_layout_range. FIXME?
2528          *
2529          */
2530         if (pgio->pg_lseg) {
2531                 seg_end = pnfs_end_offset(pgio->pg_lseg->pls_range.offset,
2532                                      pgio->pg_lseg->pls_range.length);
2533                 req_start = req_offset(req);
2534
2535                 /* start of request is past the last byte of this segment */
2536                 if (req_start >= seg_end)
2537                         return 0;
2538
2539                 /* adjust 'size' iff there are fewer bytes left in the
2540                  * segment than what nfs_generic_pg_test returned */
2541                 seg_left = seg_end - req_start;
2542                 if (seg_left < size)
2543                         size = (unsigned int)seg_left;
2544         }
2545
2546         return size;
2547 }
2548 EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
2549
2550 int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
2551 {
2552         struct nfs_pageio_descriptor pgio;
2553
2554         /* Resend all requests through the MDS */
2555         nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
2556                               hdr->completion_ops);
2557         set_bit(NFS_CONTEXT_RESEND_WRITES, &hdr->args.context->flags);
2558         return nfs_pageio_resend(&pgio, hdr);
2559 }
2560 EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
2561
2562 static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
2563 {
2564
2565         dprintk("pnfs write error = %d\n", hdr->pnfs_error);
2566         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2567             PNFS_LAYOUTRET_ON_ERROR) {
2568                 pnfs_return_layout(hdr->inode);
2569         }
2570         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2571                 hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
2572 }
2573
2574 /*
2575  * Called by non rpc-based layout drivers
2576  */
2577 void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
2578 {
2579         if (likely(!hdr->pnfs_error)) {
2580                 pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
2581                                 hdr->mds_offset + hdr->res.count);
2582                 hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2583         }
2584         trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
2585         if (unlikely(hdr->pnfs_error))
2586                 pnfs_ld_handle_write_error(hdr);
2587         hdr->mds_ops->rpc_release(hdr);
2588 }
2589 EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
2590
2591 static void
2592 pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
2593                 struct nfs_pgio_header *hdr)
2594 {
2595         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2596
2597         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2598                 list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2599                 nfs_pageio_reset_write_mds(desc);
2600                 mirror->pg_recoalesce = 1;
2601         }
2602         hdr->completion_ops->completion(hdr);
2603 }
2604
2605 static enum pnfs_try_status
2606 pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
2607                         const struct rpc_call_ops *call_ops,
2608                         struct pnfs_layout_segment *lseg,
2609                         int how)
2610 {
2611         struct inode *inode = hdr->inode;
2612         enum pnfs_try_status trypnfs;
2613         struct nfs_server *nfss = NFS_SERVER(inode);
2614
2615         hdr->mds_ops = call_ops;
2616
2617         dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
2618                 inode->i_ino, hdr->args.count, hdr->args.offset, how);
2619         trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
2620         if (trypnfs != PNFS_NOT_ATTEMPTED)
2621                 nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
2622         dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2623         return trypnfs;
2624 }
2625
2626 static void
2627 pnfs_do_write(struct nfs_pageio_descriptor *desc,
2628               struct nfs_pgio_header *hdr, int how)
2629 {
2630         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2631         struct pnfs_layout_segment *lseg = desc->pg_lseg;
2632         enum pnfs_try_status trypnfs;
2633
2634         trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
2635         switch (trypnfs) {
2636         case PNFS_NOT_ATTEMPTED:
2637                 pnfs_write_through_mds(desc, hdr);
2638         case PNFS_ATTEMPTED:
2639                 break;
2640         case PNFS_TRY_AGAIN:
2641                 /* cleanup hdr and prepare to redo pnfs */
2642                 if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2643                         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2644                         list_splice_init(&hdr->pages, &mirror->pg_list);
2645                         mirror->pg_recoalesce = 1;
2646                 }
2647                 hdr->mds_ops->rpc_release(hdr);
2648         }
2649 }
2650
2651 static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
2652 {
2653         pnfs_put_lseg(hdr->lseg);
2654         nfs_pgio_header_free(hdr);
2655 }
2656
2657 int
2658 pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
2659 {
2660         struct nfs_pgio_header *hdr;
2661         int ret;
2662
2663         hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2664         if (!hdr) {
2665                 desc->pg_error = -ENOMEM;
2666                 return desc->pg_error;
2667         }
2668         nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
2669
2670         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2671         ret = nfs_generic_pgio(desc, hdr);
2672         if (!ret)
2673                 pnfs_do_write(desc, hdr, desc->pg_ioflags);
2674
2675         return ret;
2676 }
2677 EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
2678
2679 int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
2680 {
2681         struct nfs_pageio_descriptor pgio;
2682
2683         /* Resend all requests through the MDS */
2684         nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
2685         return nfs_pageio_resend(&pgio, hdr);
2686 }
2687 EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
2688
2689 static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
2690 {
2691         dprintk("pnfs read error = %d\n", hdr->pnfs_error);
2692         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2693             PNFS_LAYOUTRET_ON_ERROR) {
2694                 pnfs_return_layout(hdr->inode);
2695         }
2696         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2697                 hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
2698 }
2699
2700 /*
2701  * Called by non rpc-based layout drivers
2702  */
2703 void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
2704 {
2705         if (likely(!hdr->pnfs_error))
2706                 hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2707         trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
2708         if (unlikely(hdr->pnfs_error))
2709                 pnfs_ld_handle_read_error(hdr);
2710         hdr->mds_ops->rpc_release(hdr);
2711 }
2712 EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
2713
2714 static void
2715 pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
2716                 struct nfs_pgio_header *hdr)
2717 {
2718         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2719
2720         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2721                 list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2722                 nfs_pageio_reset_read_mds(desc);
2723                 mirror->pg_recoalesce = 1;
2724         }
2725         hdr->completion_ops->completion(hdr);
2726 }
2727
2728 /*
2729  * Call the appropriate parallel I/O subsystem read function.
2730  */
2731 static enum pnfs_try_status
2732 pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
2733                        const struct rpc_call_ops *call_ops,
2734                        struct pnfs_layout_segment *lseg)
2735 {
2736         struct inode *inode = hdr->inode;
2737         struct nfs_server *nfss = NFS_SERVER(inode);
2738         enum pnfs_try_status trypnfs;
2739
2740         hdr->mds_ops = call_ops;
2741
2742         dprintk("%s: Reading ino:%lu %u@%llu\n",
2743                 __func__, inode->i_ino, hdr->args.count, hdr->args.offset);
2744
2745         trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
2746         if (trypnfs != PNFS_NOT_ATTEMPTED)
2747                 nfs_inc_stats(inode, NFSIOS_PNFS_READ);
2748         dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2749         return trypnfs;
2750 }
2751
2752 /* Resend all requests through pnfs. */
2753 void pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr)
2754 {
2755         struct nfs_pageio_descriptor pgio;
2756
2757         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2758                 /* Prevent deadlocks with layoutreturn! */
2759                 pnfs_put_lseg(hdr->lseg);
2760                 hdr->lseg = NULL;
2761
2762                 nfs_pageio_init_read(&pgio, hdr->inode, false,
2763                                         hdr->completion_ops);
2764                 hdr->task.tk_status = nfs_pageio_resend(&pgio, hdr);
2765         }
2766 }
2767 EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
2768
2769 static void
2770 pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
2771 {
2772         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2773         struct pnfs_layout_segment *lseg = desc->pg_lseg;
2774         enum pnfs_try_status trypnfs;
2775
2776         trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
2777         switch (trypnfs) {
2778         case PNFS_NOT_ATTEMPTED:
2779                 pnfs_read_through_mds(desc, hdr);
2780         case PNFS_ATTEMPTED:
2781                 break;
2782         case PNFS_TRY_AGAIN:
2783                 /* cleanup hdr and prepare to redo pnfs */
2784                 if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2785                         struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2786                         list_splice_init(&hdr->pages, &mirror->pg_list);
2787                         mirror->pg_recoalesce = 1;
2788                 }
2789                 hdr->mds_ops->rpc_release(hdr);
2790         }
2791 }
2792
2793 static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
2794 {
2795         pnfs_put_lseg(hdr->lseg);
2796         nfs_pgio_header_free(hdr);
2797 }
2798
2799 int
2800 pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
2801 {
2802         struct nfs_pgio_header *hdr;
2803         int ret;
2804
2805         hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2806         if (!hdr) {
2807                 desc->pg_error = -ENOMEM;
2808                 return desc->pg_error;
2809         }
2810         nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
2811         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2812         ret = nfs_generic_pgio(desc, hdr);
2813         if (!ret)
2814                 pnfs_do_read(desc, hdr);
2815         return ret;
2816 }
2817 EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
2818
2819 static void pnfs_clear_layoutcommitting(struct inode *inode)
2820 {
2821         unsigned long *bitlock = &NFS_I(inode)->flags;
2822
2823         clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
2824         smp_mb__after_atomic();
2825         wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
2826 }
2827
2828 /*
2829  * There can be multiple RW segments.
2830  */
2831 static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
2832 {
2833         struct pnfs_layout_segment *lseg;
2834
2835         list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
2836                 if (lseg->pls_range.iomode == IOMODE_RW &&
2837                     test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
2838                         list_add(&lseg->pls_lc_list, listp);
2839         }
2840 }
2841
2842 static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
2843 {
2844         struct pnfs_layout_segment *lseg, *tmp;
2845
2846         /* Matched by references in pnfs_set_layoutcommit */
2847         list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
2848                 list_del_init(&lseg->pls_lc_list);
2849                 pnfs_put_lseg(lseg);
2850         }
2851
2852         pnfs_clear_layoutcommitting(inode);
2853 }
2854
2855 void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
2856 {
2857         pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
2858 }
2859 EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
2860
2861 void
2862 pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
2863                 loff_t end_pos)
2864 {
2865         struct nfs_inode *nfsi = NFS_I(inode);
2866         bool mark_as_dirty = false;
2867
2868         spin_lock(&inode->i_lock);
2869         if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
2870                 nfsi->layout->plh_lwb = end_pos;
2871                 mark_as_dirty = true;
2872                 dprintk("%s: Set layoutcommit for inode %lu ",
2873                         __func__, inode->i_ino);
2874         } else if (end_pos > nfsi->layout->plh_lwb)
2875                 nfsi->layout->plh_lwb = end_pos;
2876         if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
2877                 /* references matched in nfs4_layoutcommit_release */
2878                 pnfs_get_lseg(lseg);
2879         }
2880         spin_unlock(&inode->i_lock);
2881         dprintk("%s: lseg %p end_pos %llu\n",
2882                 __func__, lseg, nfsi->layout->plh_lwb);
2883
2884         /* if pnfs_layoutcommit_inode() runs between inode locks, the next one
2885          * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
2886         if (mark_as_dirty)
2887                 mark_inode_dirty_sync(inode);
2888 }
2889 EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
2890
2891 void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
2892 {
2893         struct nfs_server *nfss = NFS_SERVER(data->args.inode);
2894
2895         if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
2896                 nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
2897         pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
2898 }
2899
2900 /*
2901  * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
2902  * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
2903  * data to disk to allow the server to recover the data if it crashes.
2904  * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
2905  * is off, and a COMMIT is sent to a data server, or
2906  * if WRITEs to a data server return NFS_DATA_SYNC.
2907  */
2908 int
2909 pnfs_layoutcommit_inode(struct inode *inode, bool sync)
2910 {
2911         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2912         struct nfs4_layoutcommit_data *data;
2913         struct nfs_inode *nfsi = NFS_I(inode);
2914         loff_t end_pos;
2915         int status;
2916
2917         if (!pnfs_layoutcommit_outstanding(inode))
2918                 return 0;
2919
2920         dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
2921
2922         status = -EAGAIN;
2923         if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
2924                 if (!sync)
2925                         goto out;
2926                 status = wait_on_bit_lock_action(&nfsi->flags,
2927                                 NFS_INO_LAYOUTCOMMITTING,
2928                                 nfs_wait_bit_killable,
2929                                 TASK_KILLABLE);
2930                 if (status)
2931                         goto out;
2932         }
2933
2934         status = -ENOMEM;
2935         /* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
2936         data = kzalloc(sizeof(*data), GFP_NOFS);
2937         if (!data)
2938                 goto clear_layoutcommitting;
2939
2940         status = 0;
2941         spin_lock(&inode->i_lock);
2942         if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
2943                 goto out_unlock;
2944
2945         INIT_LIST_HEAD(&data->lseg_list);
2946         pnfs_list_write_lseg(inode, &data->lseg_list);
2947
2948         end_pos = nfsi->layout->plh_lwb;
2949
2950         nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
2951         spin_unlock(&inode->i_lock);
2952
2953         data->args.inode = inode;
2954         data->cred = get_cred(nfsi->layout->plh_lc_cred);
2955         nfs_fattr_init(&data->fattr);
2956         data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
2957         data->res.fattr = &data->fattr;
2958         if (end_pos != 0)
2959                 data->args.lastbytewritten = end_pos - 1;
2960         else
2961                 data->args.lastbytewritten = U64_MAX;
2962         data->res.server = NFS_SERVER(inode);
2963
2964         if (ld->prepare_layoutcommit) {
2965                 status = ld->prepare_layoutcommit(&data->args);
2966                 if (status) {
2967                         put_cred(data->cred);
2968                         spin_lock(&inode->i_lock);
2969                         set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
2970                         if (end_pos > nfsi->layout->plh_lwb)
2971                                 nfsi->layout->plh_lwb = end_pos;
2972                         goto out_unlock;
2973                 }
2974         }
2975
2976
2977         status = nfs4_proc_layoutcommit(data, sync);
2978 out:
2979         if (status)
2980                 mark_inode_dirty_sync(inode);
2981         dprintk("<-- %s status %d\n", __func__, status);
2982         return status;
2983 out_unlock:
2984         spin_unlock(&inode->i_lock);
2985         kfree(data);
2986 clear_layoutcommitting:
2987         pnfs_clear_layoutcommitting(inode);
2988         goto out;
2989 }
2990 EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
2991
2992 int
2993 pnfs_generic_sync(struct inode *inode, bool datasync)
2994 {
2995         return pnfs_layoutcommit_inode(inode, true);
2996 }
2997 EXPORT_SYMBOL_GPL(pnfs_generic_sync);
2998
2999 struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
3000 {
3001         struct nfs4_threshold *thp;
3002
3003         thp = kzalloc(sizeof(*thp), GFP_NOFS);
3004         if (!thp) {
3005                 dprintk("%s mdsthreshold allocation failed\n", __func__);
3006                 return NULL;
3007         }
3008         return thp;
3009 }
3010
3011 #if IS_ENABLED(CONFIG_NFS_V4_2)
3012 int
3013 pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
3014 {
3015         struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3016         struct nfs_server *server = NFS_SERVER(inode);
3017         struct nfs_inode *nfsi = NFS_I(inode);
3018         struct nfs42_layoutstat_data *data;
3019         struct pnfs_layout_hdr *hdr;
3020         int status = 0;
3021
3022         if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
3023                 goto out;
3024
3025         if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
3026                 goto out;
3027
3028         if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
3029                 goto out;
3030
3031         spin_lock(&inode->i_lock);
3032         if (!NFS_I(inode)->layout) {
3033                 spin_unlock(&inode->i_lock);
3034                 goto out_clear_layoutstats;
3035         }
3036         hdr = NFS_I(inode)->layout;
3037         pnfs_get_layout_hdr(hdr);
3038         spin_unlock(&inode->i_lock);
3039
3040         data = kzalloc(sizeof(*data), gfp_flags);
3041         if (!data) {
3042                 status = -ENOMEM;
3043                 goto out_put;
3044         }
3045
3046         data->args.fh = NFS_FH(inode);
3047         data->args.inode = inode;
3048         status = ld->prepare_layoutstats(&data->args);
3049         if (status)
3050                 goto out_free;
3051
3052         status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
3053
3054 out:
3055         dprintk("%s returns %d\n", __func__, status);
3056         return status;
3057
3058 out_free:
3059         kfree(data);
3060 out_put:
3061         pnfs_put_layout_hdr(hdr);
3062 out_clear_layoutstats:
3063         smp_mb__before_atomic();
3064         clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
3065         smp_mb__after_atomic();
3066         goto out;
3067 }
3068 EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
3069 #endif
3070
3071 unsigned int layoutstats_timer;
3072 module_param(layoutstats_timer, uint, 0644);
3073 EXPORT_SYMBOL_GPL(layoutstats_timer);