root/fs/nfs/pnfs.c

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DEFINITIONS

This source file includes following definitions.
  1. find_pnfs_driver_locked
  2. find_pnfs_driver
  3. unset_pnfs_layoutdriver
  4. ld_cmp
  5. set_pnfs_layoutdriver
  6. pnfs_register_layoutdriver
  7. pnfs_unregister_layoutdriver
  8. pnfs_get_layout_hdr
  9. pnfs_alloc_layout_hdr
  10. pnfs_free_layout_hdr
  11. pnfs_detach_layout_hdr
  12. pnfs_put_layout_hdr
  13. pnfs_set_plh_return_info
  14. pnfs_clear_layoutreturn_info
  15. pnfs_clear_layoutreturn_waitbit
  16. pnfs_clear_lseg_state
  17. nfs4_layout_refresh_old_stateid
  18. pnfs_mark_layout_stateid_invalid
  19. pnfs_iomode_to_fail_bit
  20. pnfs_layout_set_fail_bit
  21. pnfs_layout_clear_fail_bit
  22. pnfs_layout_io_set_failed
  23. pnfs_layout_io_test_failed
  24. pnfs_init_lseg
  25. pnfs_free_lseg
  26. pnfs_layout_remove_lseg
  27. pnfs_cache_lseg_for_layoutreturn
  28. pnfs_put_lseg
  29. pnfs_lseg_range_contained
  30. pnfs_lseg_dec_and_remove_zero
  31. mark_lseg_invalid
  32. pnfs_seqid_is_newer
  33. pnfs_should_free_range
  34. pnfs_match_lseg_recall
  35. pnfs_mark_matching_lsegs_invalid
  36. pnfs_free_returned_lsegs
  37. pnfs_free_lseg_list
  38. pnfs_destroy_layout
  39. pnfs_layout_add_bulk_destroy_list
  40. pnfs_layout_bulk_destroy_byserver_locked
  41. pnfs_layout_free_bulk_destroy_list
  42. pnfs_destroy_layouts_byfsid
  43. pnfs_destroy_layouts_byclid
  44. pnfs_destroy_all_layouts
  45. pnfs_set_layout_stateid
  46. pnfs_layout_stateid_blocked
  47. pnfs_layoutgets_blocked
  48. pnfs_find_server
  49. nfs4_free_pages
  50. nfs4_alloc_pages
  51. pnfs_alloc_init_layoutget_args
  52. pnfs_layoutget_free
  53. pnfs_clear_layoutcommit
  54. pnfs_layoutreturn_free_lsegs
  55. pnfs_prepare_layoutreturn
  56. pnfs_init_layoutreturn_args
  57. pnfs_send_layoutreturn
  58. pnfs_layout_need_return
  59. pnfs_layoutreturn_before_put_layout_hdr
  60. _pnfs_return_layout
  61. pnfs_commit_and_return_layout
  62. pnfs_roc
  63. pnfs_roc_done
  64. pnfs_roc_release
  65. pnfs_wait_on_layoutreturn
  66. pnfs_lseg_range_cmp
  67. pnfs_lseg_range_is_after
  68. pnfs_lseg_no_merge
  69. pnfs_generic_layout_insert_lseg
  70. pnfs_layout_insert_lseg
  71. alloc_init_layout_hdr
  72. pnfs_find_alloc_layout
  73. pnfs_lseg_range_match
  74. pnfs_find_lseg
  75. pnfs_within_mdsthreshold
  76. pnfs_prepare_to_retry_layoutget
  77. nfs_layoutget_begin
  78. nfs_layoutget_end
  79. pnfs_clear_first_layoutget
  80. _add_to_server_list
  81. pnfs_update_layout
  82. pnfs_sanity_check_layout_range
  83. _pnfs_grab_empty_layout
  84. _lgopen_prepare_attached
  85. _lgopen_prepare_floating
  86. pnfs_lgopen_prepare
  87. pnfs_parse_lgopen
  88. nfs4_lgopen_release
  89. pnfs_layout_process
  90. mark_lseg_invalid_or_return
  91. pnfs_mark_matching_lsegs_return
  92. pnfs_error_mark_layout_for_return
  93. pnfs_generic_pg_check_layout
  94. pnfs_generic_pg_check_range
  95. pnfs_generic_pg_init_read
  96. pnfs_generic_pg_init_write
  97. pnfs_generic_pg_cleanup
  98. pnfs_generic_pg_test
  99. pnfs_write_done_resend_to_mds
  100. pnfs_ld_handle_write_error
  101. pnfs_ld_write_done
  102. pnfs_write_through_mds
  103. pnfs_try_to_write_data
  104. pnfs_do_write
  105. pnfs_writehdr_free
  106. pnfs_generic_pg_writepages
  107. pnfs_read_done_resend_to_mds
  108. pnfs_ld_handle_read_error
  109. pnfs_ld_read_done
  110. pnfs_read_through_mds
  111. pnfs_try_to_read_data
  112. pnfs_read_resend_pnfs
  113. pnfs_do_read
  114. pnfs_readhdr_free
  115. pnfs_generic_pg_readpages
  116. pnfs_clear_layoutcommitting
  117. pnfs_list_write_lseg
  118. pnfs_list_write_lseg_done
  119. pnfs_set_lo_fail
  120. pnfs_set_layoutcommit
  121. pnfs_cleanup_layoutcommit
  122. pnfs_layoutcommit_inode
  123. pnfs_generic_sync
  124. pnfs_mdsthreshold_alloc
  125. pnfs_report_layoutstat

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

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