fs/xfs/xfs_vnodeops.c

   1 /*
   2  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
   3  * Copyright (c) 2012 Red Hat, Inc.
   4  * All Rights Reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it would be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write the Free Software Foundation,
  17  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19
  20 #include "xfs.h"
  21 #include "xfs_fs.h"
  22 #include "xfs_types.h"
  23 #include "xfs_bit.h"
  24 #include "xfs_log.h"
  25 #include "xfs_trans.h"
  26 #include "xfs_sb.h"
  27 #include "xfs_ag.h"
  28 #include "xfs_dir2.h"
  29 #include "xfs_mount.h"
  30 #include "xfs_da_btree.h"
  31 #include "xfs_bmap_btree.h"
  32 #include "xfs_ialloc_btree.h"
  33 #include "xfs_dinode.h"
  34 #include "xfs_inode.h"
  35 #include "xfs_inode_item.h"
  36 #include "xfs_itable.h"
  37 #include "xfs_ialloc.h"
  38 #include "xfs_alloc.h"
  39 #include "xfs_bmap.h"
  40 #include "xfs_acl.h"
  41 #include "xfs_attr.h"
  42 #include "xfs_error.h"
  43 #include "xfs_quota.h"
  44 #include "xfs_utils.h"
  45 #include "xfs_rtalloc.h"
  46 #include "xfs_trans_space.h"
  47 #include "xfs_log_priv.h"
  48 #include "xfs_filestream.h"
  49 #include "xfs_vnodeops.h"
  50 #include "xfs_trace.h"
  51 #include "xfs_icache.h"
  52 #include "xfs_symlink.h"
  53
  54
  55 /*
  56  * This is called by xfs_inactive to free any blocks beyond eof
  57  * when the link count isn't zero and by xfs_dm_punch_hole() when
  58  * punching a hole to EOF.
  59  */
  60 int
  61 xfs_free_eofblocks(
  62         xfs_mount_t     *mp,
  63         xfs_inode_t     *ip,
  64         bool            need_iolock)
  65 {
  66         xfs_trans_t     *tp;
  67         int             error;
  68         xfs_fileoff_t   end_fsb;
  69         xfs_fileoff_t   last_fsb;
  70         xfs_filblks_t   map_len;
  71         int             nimaps;
  72         xfs_bmbt_irec_t imap;
  73
  74         /*
  75          * Figure out if there are any blocks beyond the end
  76          * of the file.  If not, then there is nothing to do.
  77          */
  78         end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip));
  79         last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
  80         if (last_fsb <= end_fsb)
  81                 return 0;
  82         map_len = last_fsb - end_fsb;
  83
  84         nimaps = 1;
  85         xfs_ilock(ip, XFS_ILOCK_SHARED);
  86         error = xfs_bmapi_read(ip, end_fsb, map_len, &imap, &nimaps, 0);
  87         xfs_iunlock(ip, XFS_ILOCK_SHARED);
  88
  89         if (!error && (nimaps != 0) &&
  90             (imap.br_startblock != HOLESTARTBLOCK ||
  91              ip->i_delayed_blks)) {
  92                 /*
  93                  * Attach the dquots to the inode up front.
  94                  */
  95                 error = xfs_qm_dqattach(ip, 0);
  96                 if (error)
  97                         return error;
  98
  99                 /*
 100                  * There are blocks after the end of file.
 101                  * Free them up now by truncating the file to
 102                  * its current size.
 103                  */
 104                 tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
 105
 106                 if (need_iolock) {
 107                         if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
 108                                 xfs_trans_cancel(tp, 0);
 109                                 return EAGAIN;
 110                         }
 111                 }
 112
 113                 error = xfs_trans_reserve(tp, 0,
 114                                           XFS_ITRUNCATE_LOG_RES(mp),
 115                                           0, XFS_TRANS_PERM_LOG_RES,
 116                                           XFS_ITRUNCATE_LOG_COUNT);
 117                 if (error) {
 118                         ASSERT(XFS_FORCED_SHUTDOWN(mp));
 119                         xfs_trans_cancel(tp, 0);
 120                         if (need_iolock)
 121                                 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
 122                         return error;
 123                 }
 124
 125                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 126                 xfs_trans_ijoin(tp, ip, 0);
 127
 128                 /*
 129                  * Do not update the on-disk file size.  If we update the
 130                  * on-disk file size and then the system crashes before the
 131                  * contents of the file are flushed to disk then the files
 132                  * may be full of holes (ie NULL files bug).
 133                  */
 134                 error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK,
 135                                               XFS_ISIZE(ip));
 136                 if (error) {
 137                         /*
 138                          * If we get an error at this point we simply don't
 139                          * bother truncating the file.
 140                          */
 141                         xfs_trans_cancel(tp,
 142                                          (XFS_TRANS_RELEASE_LOG_RES |
 143                                           XFS_TRANS_ABORT));
 144                 } else {
 145                         error = xfs_trans_commit(tp,
 146                                                 XFS_TRANS_RELEASE_LOG_RES);
 147                         if (!error)
 148                                 xfs_inode_clear_eofblocks_tag(ip);
 149                 }
 150
 151                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 152                 if (need_iolock)
 153                         xfs_iunlock(ip, XFS_IOLOCK_EXCL);
 154         }
 155         return error;
 156 }
 157
 158 int
 159 xfs_release(
 160         xfs_inode_t     *ip)
 161 {
 162         xfs_mount_t     *mp = ip->i_mount;
 163         int             error;
 164
 165         if (!S_ISREG(ip->i_d.di_mode) || (ip->i_d.di_mode == 0))
 166                 return 0;
 167
 168         /* If this is a read-only mount, don't do this (would generate I/O) */
 169         if (mp->m_flags & XFS_MOUNT_RDONLY)
 170                 return 0;
 171
 172         if (!XFS_FORCED_SHUTDOWN(mp)) {
 173                 int truncated;
 174
 175                 /*
 176                  * If we are using filestreams, and we have an unlinked
 177                  * file that we are processing the last close on, then nothing
 178                  * will be able to reopen and write to this file. Purge this
 179                  * inode from the filestreams cache so that it doesn't delay
 180                  * teardown of the inode.
 181                  */
 182                 if ((ip->i_d.di_nlink == 0) && xfs_inode_is_filestream(ip))
 183                         xfs_filestream_deassociate(ip);
 184
 185                 /*
 186                  * If we previously truncated this file and removed old data
 187                  * in the process, we want to initiate "early" writeout on
 188                  * the last close.  This is an attempt to combat the notorious
 189                  * NULL files problem which is particularly noticeable from a
 190                  * truncate down, buffered (re-)write (delalloc), followed by
 191                  * a crash.  What we are effectively doing here is
 192                  * significantly reducing the time window where we'd otherwise
 193                  * be exposed to that problem.
 194                  */
 195                 truncated = xfs_iflags_test_and_clear(ip, XFS_ITRUNCATED);
 196                 if (truncated) {
 197                         xfs_iflags_clear(ip, XFS_IDIRTY_RELEASE);
 198                         if (VN_DIRTY(VFS_I(ip)) && ip->i_delayed_blks > 0) {
 199                                 error = -filemap_flush(VFS_I(ip)->i_mapping);
 200                                 if (error)
 201                                         return error;
 202                         }
 203                 }
 204         }
 205
 206         if (ip->i_d.di_nlink == 0)
 207                 return 0;
 208
 209         if (xfs_can_free_eofblocks(ip, false)) {
 210
 211                 /*
 212                  * If we can't get the iolock just skip truncating the blocks
 213                  * past EOF because we could deadlock with the mmap_sem
 214                  * otherwise.  We'll get another chance to drop them once the
 215                  * last reference to the inode is dropped, so we'll never leak
 216                  * blocks permanently.
 217                  *
 218                  * Further, check if the inode is being opened, written and
 219                  * closed frequently and we have delayed allocation blocks
 220                  * outstanding (e.g. streaming writes from the NFS server),
 221                  * truncating the blocks past EOF will cause fragmentation to
 222                  * occur.
 223                  *
 224                  * In this case don't do the truncation, either, but we have to
 225                  * be careful how we detect this case. Blocks beyond EOF show
 226                  * up as i_delayed_blks even when the inode is clean, so we
 227                  * need to truncate them away first before checking for a dirty
 228                  * release. Hence on the first dirty close we will still remove
 229                  * the speculative allocation, but after that we will leave it
 230                  * in place.
 231                  */
 232                 if (xfs_iflags_test(ip, XFS_IDIRTY_RELEASE))
 233                         return 0;
 234
 235                 error = xfs_free_eofblocks(mp, ip, true);
 236                 if (error && error != EAGAIN)
 237                         return error;
 238
 239                 /* delalloc blocks after truncation means it really is dirty */
 240                 if (ip->i_delayed_blks)
 241                         xfs_iflags_set(ip, XFS_IDIRTY_RELEASE);
 242         }
 243         return 0;
 244 }
 245
 246 /*
 247  * xfs_inactive
 248  *
 249  * This is called when the vnode reference count for the vnode
 250  * goes to zero.  If the file has been unlinked, then it must
 251  * now be truncated.  Also, we clear all of the read-ahead state
 252  * kept for the inode here since the file is now closed.
 253  */
 254 int
 255 xfs_inactive(
 256         xfs_inode_t     *ip)
 257 {
 258         xfs_bmap_free_t free_list;
 259         xfs_fsblock_t   first_block;
 260         int             committed;
 261         xfs_trans_t     *tp;
 262         xfs_mount_t     *mp;
 263         int             error;
 264         int             truncate = 0;
 265
 266         /*
 267          * If the inode is already free, then there can be nothing
 268          * to clean up here.
 269          */
 270         if (ip->i_d.di_mode == 0 || is_bad_inode(VFS_I(ip))) {
 271                 ASSERT(ip->i_df.if_real_bytes == 0);
 272                 ASSERT(ip->i_df.if_broot_bytes == 0);
 273                 return VN_INACTIVE_CACHE;
 274         }
 275
 276         mp = ip->i_mount;
 277
 278         error = 0;
 279
 280         /* If this is a read-only mount, don't do this (would generate I/O) */
 281         if (mp->m_flags & XFS_MOUNT_RDONLY)
 282                 goto out;
 283
 284         if (ip->i_d.di_nlink != 0) {
 285                 /*
 286                  * force is true because we are evicting an inode from the
 287                  * cache. Post-eof blocks must be freed, lest we end up with
 288                  * broken free space accounting.
 289                  */
 290                 if (xfs_can_free_eofblocks(ip, true)) {
 291                         error = xfs_free_eofblocks(mp, ip, false);
 292                         if (error)
 293                                 return VN_INACTIVE_CACHE;
 294                 }
 295                 goto out;
 296         }
 297
 298         if (S_ISREG(ip->i_d.di_mode) &&
 299             (ip->i_d.di_size != 0 || XFS_ISIZE(ip) != 0 ||
 300              ip->i_d.di_nextents > 0 || ip->i_delayed_blks > 0))
 301                 truncate = 1;
 302
 303         error = xfs_qm_dqattach(ip, 0);
 304         if (error)
 305                 return VN_INACTIVE_CACHE;
 306
 307         tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
 308         error = xfs_trans_reserve(tp, 0,
 309                         (truncate || S_ISLNK(ip->i_d.di_mode)) ?
 310                                 XFS_ITRUNCATE_LOG_RES(mp) :
 311                                 XFS_IFREE_LOG_RES(mp),
 312                         0,
 313                         XFS_TRANS_PERM_LOG_RES,
 314                         XFS_ITRUNCATE_LOG_COUNT);
 315         if (error) {
 316                 ASSERT(XFS_FORCED_SHUTDOWN(mp));
 317                 xfs_trans_cancel(tp, 0);
 318                 return VN_INACTIVE_CACHE;
 319         }
 320
 321         xfs_ilock(ip, XFS_ILOCK_EXCL);
 322         xfs_trans_ijoin(tp, ip, 0);
 323
 324         if (S_ISLNK(ip->i_d.di_mode)) {
 325                 /*
 326                  * Zero length symlinks _can_ exist.
 327                  */
 328                 if (ip->i_d.di_size > XFS_IFORK_DSIZE(ip)) {
 329                         error = xfs_inactive_symlink_rmt(ip, &tp);
 330                         if (error)
 331                                 goto out_cancel;
 332                 } else if (ip->i_df.if_bytes > 0) {
 333                         xfs_idata_realloc(ip, -(ip->i_df.if_bytes),
 334                                           XFS_DATA_FORK);
 335                         ASSERT(ip->i_df.if_bytes == 0);
 336                 }
 337         } else if (truncate) {
 338                 ip->i_d.di_size = 0;
 339                 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 340
 341                 error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, 0);
 342                 if (error)
 343                         goto out_cancel;
 344
 345                 ASSERT(ip->i_d.di_nextents == 0);
 346         }
 347
 348         /*
 349          * If there are attributes associated with the file then blow them away
 350          * now.  The code calls a routine that recursively deconstructs the
 351          * attribute fork.  We need to just commit the current transaction
 352          * because we can't use it for xfs_attr_inactive().
 353          */
 354         if (ip->i_d.di_anextents > 0) {
 355                 ASSERT(ip->i_d.di_forkoff != 0);
 356
 357                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 358                 if (error)
 359                         goto out_unlock;
 360
 361                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 362
 363                 error = xfs_attr_inactive(ip);
 364                 if (error)
 365                         goto out;
 366
 367                 tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
 368                 error = xfs_trans_reserve(tp, 0,
 369                                           XFS_IFREE_LOG_RES(mp),
 370                                           0, XFS_TRANS_PERM_LOG_RES,
 371                                           XFS_INACTIVE_LOG_COUNT);
 372                 if (error) {
 373                         xfs_trans_cancel(tp, 0);
 374                         goto out;
 375                 }
 376
 377                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 378                 xfs_trans_ijoin(tp, ip, 0);
 379         }
 380
 381         if (ip->i_afp)
 382                 xfs_idestroy_fork(ip, XFS_ATTR_FORK);
 383
 384         ASSERT(ip->i_d.di_anextents == 0);
 385
 386         /*
 387          * Free the inode.
 388          */
 389         xfs_bmap_init(&free_list, &first_block);
 390         error = xfs_ifree(tp, ip, &free_list);
 391         if (error) {
 392                 /*
 393                  * If we fail to free the inode, shut down.  The cancel
 394                  * might do that, we need to make sure.  Otherwise the
 395                  * inode might be lost for a long time or forever.
 396                  */
 397                 if (!XFS_FORCED_SHUTDOWN(mp)) {
 398                         xfs_notice(mp, "%s: xfs_ifree returned error %d",
 399                                 __func__, error);
 400                         xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
 401                 }
 402                 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES|XFS_TRANS_ABORT);
 403         } else {
 404                 /*
 405                  * Credit the quota account(s). The inode is gone.
 406                  */
 407                 xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_ICOUNT, -1);
 408
 409                 /*
 410                  * Just ignore errors at this point.  There is nothing we can
 411                  * do except to try to keep going. Make sure it's not a silent
 412                  * error.
 413                  */
 414                 error = xfs_bmap_finish(&tp,  &free_list, &committed);
 415                 if (error)
 416                         xfs_notice(mp, "%s: xfs_bmap_finish returned error %d",
 417                                 __func__, error);
 418                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 419                 if (error)
 420                         xfs_notice(mp, "%s: xfs_trans_commit returned error %d",
 421                                 __func__, error);
 422         }
 423
 424         /*
 425          * Release the dquots held by inode, if any.
 426          */
 427         xfs_qm_dqdetach(ip);
 428 out_unlock:
 429         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 430 out:
 431         return VN_INACTIVE_CACHE;
 432 out_cancel:
 433         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
 434         goto out_unlock;
 435 }
 436
 437 /*
 438  * Lookups up an inode from "name". If ci_name is not NULL, then a CI match
 439  * is allowed, otherwise it has to be an exact match. If a CI match is found,
 440  * ci_name->name will point to a the actual name (caller must free) or
 441  * will be set to NULL if an exact match is found.
 442  */
 443 int
 444 xfs_lookup(
 445         xfs_inode_t             *dp,
 446         struct xfs_name         *name,
 447         xfs_inode_t             **ipp,
 448         struct xfs_name         *ci_name)
 449 {
 450         xfs_ino_t               inum;
 451         int                     error;
 452         uint                    lock_mode;
 453
 454         trace_xfs_lookup(dp, name);
 455
 456         if (XFS_FORCED_SHUTDOWN(dp->i_mount))
 457                 return XFS_ERROR(EIO);
 458
 459         lock_mode = xfs_ilock_map_shared(dp);
 460         error = xfs_dir_lookup(NULL, dp, name, &inum, ci_name);
 461         xfs_iunlock_map_shared(dp, lock_mode);
 462
 463         if (error)
 464                 goto out;
 465
 466         error = xfs_iget(dp->i_mount, NULL, inum, 0, 0, ipp);
 467         if (error)
 468                 goto out_free_name;
 469
 470         return 0;
 471
 472 out_free_name:
 473         if (ci_name)
 474                 kmem_free(ci_name->name);
 475 out:
 476         *ipp = NULL;
 477         return error;
 478 }
 479
 480 int
 481 xfs_create(
 482         xfs_inode_t             *dp,
 483         struct xfs_name         *name,
 484         umode_t                 mode,
 485         xfs_dev_t               rdev,
 486         xfs_inode_t             **ipp)
 487 {
 488         int                     is_dir = S_ISDIR(mode);
 489         struct xfs_mount        *mp = dp->i_mount;
 490         struct xfs_inode        *ip = NULL;
 491         struct xfs_trans        *tp = NULL;
 492         int                     error;
 493         xfs_bmap_free_t         free_list;
 494         xfs_fsblock_t           first_block;
 495         bool                    unlock_dp_on_error = false;
 496         uint                    cancel_flags;
 497         int                     committed;
 498         prid_t                  prid;
 499         struct xfs_dquot        *udqp = NULL;
 500         struct xfs_dquot        *gdqp = NULL;
 501         uint                    resblks;
 502         uint                    log_res;
 503         uint                    log_count;
 504
 505         trace_xfs_create(dp, name);
 506
 507         if (XFS_FORCED_SHUTDOWN(mp))
 508                 return XFS_ERROR(EIO);
 509
 510         if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
 511                 prid = xfs_get_projid(dp);
 512         else
 513                 prid = XFS_PROJID_DEFAULT;
 514
 515         /*
 516          * Make sure that we have allocated dquot(s) on disk.
 517          */
 518         error = xfs_qm_vop_dqalloc(dp, current_fsuid(), current_fsgid(), prid,
 519                         XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT, &udqp, &gdqp);
 520         if (error)
 521                 return error;
 522
 523         if (is_dir) {
 524                 rdev = 0;
 525                 resblks = XFS_MKDIR_SPACE_RES(mp, name->len);
 526                 log_res = XFS_MKDIR_LOG_RES(mp);
 527                 log_count = XFS_MKDIR_LOG_COUNT;
 528                 tp = xfs_trans_alloc(mp, XFS_TRANS_MKDIR);
 529         } else {
 530                 resblks = XFS_CREATE_SPACE_RES(mp, name->len);
 531                 log_res = XFS_CREATE_LOG_RES(mp);
 532                 log_count = XFS_CREATE_LOG_COUNT;
 533                 tp = xfs_trans_alloc(mp, XFS_TRANS_CREATE);
 534         }
 535
 536         cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
 537
 538         /*
 539          * Initially assume that the file does not exist and
 540          * reserve the resources for that case.  If that is not
 541          * the case we'll drop the one we have and get a more
 542          * appropriate transaction later.
 543          */
 544         error = xfs_trans_reserve(tp, resblks, log_res, 0,
 545                         XFS_TRANS_PERM_LOG_RES, log_count);
 546         if (error == ENOSPC) {
 547                 /* flush outstanding delalloc blocks and retry */
 548                 xfs_flush_inodes(mp);
 549                 error = xfs_trans_reserve(tp, resblks, log_res, 0,
 550                                 XFS_TRANS_PERM_LOG_RES, log_count);
 551         }
 552         if (error == ENOSPC) {
 553                 /* No space at all so try a "no-allocation" reservation */
 554                 resblks = 0;
 555                 error = xfs_trans_reserve(tp, 0, log_res, 0,
 556                                 XFS_TRANS_PERM_LOG_RES, log_count);
 557         }
 558         if (error) {
 559                 cancel_flags = 0;
 560                 goto out_trans_cancel;
 561         }
 562
 563         xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
 564         unlock_dp_on_error = true;
 565
 566         xfs_bmap_init(&free_list, &first_block);
 567
 568         /*
 569          * Reserve disk quota and the inode.
 570          */
 571         error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp, resblks, 1, 0);
 572         if (error)
 573                 goto out_trans_cancel;
 574
 575         error = xfs_dir_canenter(tp, dp, name, resblks);
 576         if (error)
 577                 goto out_trans_cancel;
 578
 579         /*
 580          * A newly created regular or special file just has one directory
 581          * entry pointing to them, but a directory also the "." entry
 582          * pointing to itself.
 583          */
 584         error = xfs_dir_ialloc(&tp, dp, mode, is_dir ? 2 : 1, rdev,
 585                                prid, resblks > 0, &ip, &committed);
 586         if (error) {
 587                 if (error == ENOSPC)
 588                         goto out_trans_cancel;
 589                 goto out_trans_abort;
 590         }
 591
 592         /*
 593          * Now we join the directory inode to the transaction.  We do not do it
 594          * earlier because xfs_dir_ialloc might commit the previous transaction
 595          * (and release all the locks).  An error from here on will result in
 596          * the transaction cancel unlocking dp so don't do it explicitly in the
 597          * error path.
 598          */
 599         xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
 600         unlock_dp_on_error = false;
 601
 602         error = xfs_dir_createname(tp, dp, name, ip->i_ino,
 603                                         &first_block, &free_list, resblks ?
 604                                         resblks - XFS_IALLOC_SPACE_RES(mp) : 0);
 605         if (error) {
 606                 ASSERT(error != ENOSPC);
 607                 goto out_trans_abort;
 608         }
 609         xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
 610         xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
 611
 612         if (is_dir) {
 613                 error = xfs_dir_init(tp, ip, dp);
 614                 if (error)
 615                         goto out_bmap_cancel;
 616
 617                 error = xfs_bumplink(tp, dp);
 618                 if (error)
 619                         goto out_bmap_cancel;
 620         }
 621
 622         /*
 623          * If this is a synchronous mount, make sure that the
 624          * create transaction goes to disk before returning to
 625          * the user.
 626          */
 627         if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
 628                 xfs_trans_set_sync(tp);
 629
 630         /*
 631          * Attach the dquot(s) to the inodes and modify them incore.
 632          * These ids of the inode couldn't have changed since the new
 633          * inode has been locked ever since it was created.
 634          */
 635         xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp);
 636
 637         error = xfs_bmap_finish(&tp, &free_list, &committed);
 638         if (error)
 639                 goto out_bmap_cancel;
 640
 641         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 642         if (error)
 643                 goto out_release_inode;
 644
 645         xfs_qm_dqrele(udqp);
 646         xfs_qm_dqrele(gdqp);
 647
 648         *ipp = ip;
 649         return 0;
 650
 651  out_bmap_cancel:
 652         xfs_bmap_cancel(&free_list);
 653  out_trans_abort:
 654         cancel_flags |= XFS_TRANS_ABORT;
 655  out_trans_cancel:
 656         xfs_trans_cancel(tp, cancel_flags);
 657  out_release_inode:
 658         /*
 659          * Wait until after the current transaction is aborted to
 660          * release the inode.  This prevents recursive transactions
 661          * and deadlocks from xfs_inactive.
 662          */
 663         if (ip)
 664                 IRELE(ip);
 665
 666         xfs_qm_dqrele(udqp);
 667         xfs_qm_dqrele(gdqp);
 668
 669         if (unlock_dp_on_error)
 670                 xfs_iunlock(dp, XFS_ILOCK_EXCL);
 671         return error;
 672 }
 673
 674 #ifdef DEBUG
 675 int xfs_locked_n;
 676 int xfs_small_retries;
 677 int xfs_middle_retries;
 678 int xfs_lots_retries;
 679 int xfs_lock_delays;
 680 #endif
 681
 682 /*
 683  * Bump the subclass so xfs_lock_inodes() acquires each lock with
 684  * a different value
 685  */
 686 static inline int
 687 xfs_lock_inumorder(int lock_mode, int subclass)
 688 {
 689         if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL))
 690                 lock_mode |= (subclass + XFS_LOCK_INUMORDER) << XFS_IOLOCK_SHIFT;
 691         if (lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))
 692                 lock_mode |= (subclass + XFS_LOCK_INUMORDER) << XFS_ILOCK_SHIFT;
 693
 694         return lock_mode;
 695 }
 696
 697 /*
 698  * The following routine will lock n inodes in exclusive mode.
 699  * We assume the caller calls us with the inodes in i_ino order.
 700  *
 701  * We need to detect deadlock where an inode that we lock
 702  * is in the AIL and we start waiting for another inode that is locked
 703  * by a thread in a long running transaction (such as truncate). This can
 704  * result in deadlock since the long running trans might need to wait
 705  * for the inode we just locked in order to push the tail and free space
 706  * in the log.
 707  */
 708 void
 709 xfs_lock_inodes(
 710         xfs_inode_t     **ips,
 711         int             inodes,
 712         uint            lock_mode)
 713 {
 714         int             attempts = 0, i, j, try_lock;
 715         xfs_log_item_t  *lp;
 716
 717         ASSERT(ips && (inodes >= 2)); /* we need at least two */
 718
 719         try_lock = 0;
 720         i = 0;
 721
 722 again:
 723         for (; i < inodes; i++) {
 724                 ASSERT(ips[i]);
 725
 726                 if (i && (ips[i] == ips[i-1]))  /* Already locked */
 727                         continue;
 728
 729                 /*
 730                  * If try_lock is not set yet, make sure all locked inodes
 731                  * are not in the AIL.
 732                  * If any are, set try_lock to be used later.
 733                  */
 734
 735                 if (!try_lock) {
 736                         for (j = (i - 1); j >= 0 && !try_lock; j--) {
 737                                 lp = (xfs_log_item_t *)ips[j]->i_itemp;
 738                                 if (lp && (lp->li_flags & XFS_LI_IN_AIL)) {
 739                                         try_lock++;
 740                                 }
 741                         }
 742                 }
 743
 744                 /*
 745                  * If any of the previous locks we have locked is in the AIL,
 746                  * we must TRY to get the second and subsequent locks. If
 747                  * we can't get any, we must release all we have
 748                  * and try again.
 749                  */
 750
 751                 if (try_lock) {
 752                         /* try_lock must be 0 if i is 0. */
 753                         /*
 754                          * try_lock means we have an inode locked
 755                          * that is in the AIL.
 756                          */
 757                         ASSERT(i != 0);
 758                         if (!xfs_ilock_nowait(ips[i], xfs_lock_inumorder(lock_mode, i))) {
 759                                 attempts++;
 760
 761                                 /*
 762                                  * Unlock all previous guys and try again.
 763                                  * xfs_iunlock will try to push the tail
 764                                  * if the inode is in the AIL.
 765                                  */
 766
 767                                 for(j = i - 1; j >= 0; j--) {
 768
 769                                         /*
 770                                          * Check to see if we've already
 771                                          * unlocked this one.
 772                                          * Not the first one going back,
 773                                          * and the inode ptr is the same.
 774                                          */
 775                                         if ((j != (i - 1)) && ips[j] ==
 776                                                                 ips[j+1])
 777                                                 continue;
 778
 779                                         xfs_iunlock(ips[j], lock_mode);
 780                                 }
 781
 782                                 if ((attempts % 5) == 0) {
 783                                         delay(1); /* Don't just spin the CPU */
 784 #ifdef DEBUG
 785                                         xfs_lock_delays++;
 786 #endif
 787                                 }
 788                                 i = 0;
 789                                 try_lock = 0;
 790                                 goto again;
 791                         }
 792                 } else {
 793                         xfs_ilock(ips[i], xfs_lock_inumorder(lock_mode, i));
 794                 }
 795         }
 796
 797 #ifdef DEBUG
 798         if (attempts) {
 799                 if (attempts < 5) xfs_small_retries++;
 800                 else if (attempts < 100) xfs_middle_retries++;
 801                 else xfs_lots_retries++;
 802         } else {
 803                 xfs_locked_n++;
 804         }
 805 #endif
 806 }
 807
 808 /*
 809  * xfs_lock_two_inodes() can only be used to lock one type of lock
 810  * at a time - the iolock or the ilock, but not both at once. If
 811  * we lock both at once, lockdep will report false positives saying
 812  * we have violated locking orders.
 813  */
 814 void
 815 xfs_lock_two_inodes(
 816         xfs_inode_t             *ip0,
 817         xfs_inode_t             *ip1,
 818         uint                    lock_mode)
 819 {
 820         xfs_inode_t             *temp;
 821         int                     attempts = 0;
 822         xfs_log_item_t          *lp;
 823
 824         if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL))
 825                 ASSERT((lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)) == 0);
 826         ASSERT(ip0->i_ino != ip1->i_ino);
 827
 828         if (ip0->i_ino > ip1->i_ino) {
 829                 temp = ip0;
 830                 ip0 = ip1;
 831                 ip1 = temp;
 832         }
 833
 834  again:
 835         xfs_ilock(ip0, xfs_lock_inumorder(lock_mode, 0));
 836
 837         /*
 838          * If the first lock we have locked is in the AIL, we must TRY to get
 839          * the second lock. If we can't get it, we must release the first one
 840          * and try again.
 841          */
 842         lp = (xfs_log_item_t *)ip0->i_itemp;
 843         if (lp && (lp->li_flags & XFS_LI_IN_AIL)) {
 844                 if (!xfs_ilock_nowait(ip1, xfs_lock_inumorder(lock_mode, 1))) {
 845                         xfs_iunlock(ip0, lock_mode);
 846                         if ((++attempts % 5) == 0)
 847                                 delay(1); /* Don't just spin the CPU */
 848                         goto again;
 849                 }
 850         } else {
 851                 xfs_ilock(ip1, xfs_lock_inumorder(lock_mode, 1));
 852         }
 853 }
 854
 855 int
 856 xfs_remove(
 857         xfs_inode_t             *dp,
 858         struct xfs_name         *name,
 859         xfs_inode_t             *ip)
 860 {
 861         xfs_mount_t             *mp = dp->i_mount;
 862         xfs_trans_t             *tp = NULL;
 863         int                     is_dir = S_ISDIR(ip->i_d.di_mode);
 864         int                     error = 0;
 865         xfs_bmap_free_t         free_list;
 866         xfs_fsblock_t           first_block;
 867         int                     cancel_flags;
 868         int                     committed;
 869         int                     link_zero;
 870         uint                    resblks;
 871         uint                    log_count;
 872
 873         trace_xfs_remove(dp, name);
 874
 875         if (XFS_FORCED_SHUTDOWN(mp))
 876                 return XFS_ERROR(EIO);
 877
 878         error = xfs_qm_dqattach(dp, 0);
 879         if (error)
 880                 goto std_return;
 881
 882         error = xfs_qm_dqattach(ip, 0);
 883         if (error)
 884                 goto std_return;
 885
 886         if (is_dir) {
 887                 tp = xfs_trans_alloc(mp, XFS_TRANS_RMDIR);
 888                 log_count = XFS_DEFAULT_LOG_COUNT;
 889         } else {
 890                 tp = xfs_trans_alloc(mp, XFS_TRANS_REMOVE);
 891                 log_count = XFS_REMOVE_LOG_COUNT;
 892         }
 893         cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
 894
 895         /*
 896          * We try to get the real space reservation first,
 897          * allowing for directory btree deletion(s) implying
 898          * possible bmap insert(s).  If we can't get the space
 899          * reservation then we use 0 instead, and avoid the bmap
 900          * btree insert(s) in the directory code by, if the bmap
 901          * insert tries to happen, instead trimming the LAST
 902          * block from the directory.
 903          */
 904         resblks = XFS_REMOVE_SPACE_RES(mp);
 905         error = xfs_trans_reserve(tp, resblks, XFS_REMOVE_LOG_RES(mp), 0,
 906                                   XFS_TRANS_PERM_LOG_RES, log_count);
 907         if (error == ENOSPC) {
 908                 resblks = 0;
 909                 error = xfs_trans_reserve(tp, 0, XFS_REMOVE_LOG_RES(mp), 0,
 910                                           XFS_TRANS_PERM_LOG_RES, log_count);
 911         }
 912         if (error) {
 913                 ASSERT(error != ENOSPC);
 914                 cancel_flags = 0;
 915                 goto out_trans_cancel;
 916         }
 917
 918         xfs_lock_two_inodes(dp, ip, XFS_ILOCK_EXCL);
 919
 920         xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
 921         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 922
 923         /*
 924          * If we're removing a directory perform some additional validation.
 925          */
 926         if (is_dir) {
 927                 ASSERT(ip->i_d.di_nlink >= 2);
 928                 if (ip->i_d.di_nlink != 2) {
 929                         error = XFS_ERROR(ENOTEMPTY);
 930                         goto out_trans_cancel;
 931                 }
 932                 if (!xfs_dir_isempty(ip)) {
 933                         error = XFS_ERROR(ENOTEMPTY);
 934                         goto out_trans_cancel;
 935                 }
 936         }
 937
 938         xfs_bmap_init(&free_list, &first_block);
 939         error = xfs_dir_removename(tp, dp, name, ip->i_ino,
 940                                         &first_block, &free_list, resblks);
 941         if (error) {
 942                 ASSERT(error != ENOENT);
 943                 goto out_bmap_cancel;
 944         }
 945         xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
 946
 947         if (is_dir) {
 948                 /*
 949                  * Drop the link from ip's "..".
 950                  */
 951                 error = xfs_droplink(tp, dp);
 952                 if (error)
 953                         goto out_bmap_cancel;
 954
 955                 /*
 956                  * Drop the "." link from ip to self.
 957                  */
 958                 error = xfs_droplink(tp, ip);
 959                 if (error)
 960                         goto out_bmap_cancel;
 961         } else {
 962                 /*
 963                  * When removing a non-directory we need to log the parent
 964                  * inode here.  For a directory this is done implicitly
 965                  * by the xfs_droplink call for the ".." entry.
 966                  */
 967                 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
 968         }
 969
 970         /*
 971          * Drop the link from dp to ip.
 972          */
 973         error = xfs_droplink(tp, ip);
 974         if (error)
 975                 goto out_bmap_cancel;
 976
 977         /*
 978          * Determine if this is the last link while
 979          * we are in the transaction.
 980          */
 981         link_zero = (ip->i_d.di_nlink == 0);
 982
 983         /*
 984          * If this is a synchronous mount, make sure that the
 985          * remove transaction goes to disk before returning to
 986          * the user.
 987          */
 988         if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
 989                 xfs_trans_set_sync(tp);
 990
 991         error = xfs_bmap_finish(&tp, &free_list, &committed);
 992         if (error)
 993                 goto out_bmap_cancel;
 994
 995         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 996         if (error)
 997                 goto std_return;
 998
 999         /*
1000          * If we are using filestreams, kill the stream association.
1001          * If the file is still open it may get a new one but that
1002          * will get killed on last close in xfs_close() so we don't
1003          * have to worry about that.
1004          */
1005         if (!is_dir && link_zero && xfs_inode_is_filestream(ip))
1006                 xfs_filestream_deassociate(ip);
1007
1008         return 0;
1009
1010  out_bmap_cancel:
1011         xfs_bmap_cancel(&free_list);
1012         cancel_flags |= XFS_TRANS_ABORT;
1013  out_trans_cancel:
1014         xfs_trans_cancel(tp, cancel_flags);
1015  std_return:
1016         return error;
1017 }
1018
1019 int
1020 xfs_link(
1021         xfs_inode_t             *tdp,
1022         xfs_inode_t             *sip,
1023         struct xfs_name         *target_name)
1024 {
1025         xfs_mount_t             *mp = tdp->i_mount;
1026         xfs_trans_t             *tp;
1027         int                     error;
1028         xfs_bmap_free_t         free_list;
1029         xfs_fsblock_t           first_block;
1030         int                     cancel_flags;
1031         int                     committed;
1032         int                     resblks;
1033
1034         trace_xfs_link(tdp, target_name);
1035
1036         ASSERT(!S_ISDIR(sip->i_d.di_mode));
1037
1038         if (XFS_FORCED_SHUTDOWN(mp))
1039                 return XFS_ERROR(EIO);
1040
1041         error = xfs_qm_dqattach(sip, 0);
1042         if (error)
1043                 goto std_return;
1044
1045         error = xfs_qm_dqattach(tdp, 0);
1046         if (error)
1047                 goto std_return;
1048
1049         tp = xfs_trans_alloc(mp, XFS_TRANS_LINK);
1050         cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
1051         resblks = XFS_LINK_SPACE_RES(mp, target_name->len);
1052         error = xfs_trans_reserve(tp, resblks, XFS_LINK_LOG_RES(mp), 0,
1053                         XFS_TRANS_PERM_LOG_RES, XFS_LINK_LOG_COUNT);
1054         if (error == ENOSPC) {
1055                 resblks = 0;
1056                 error = xfs_trans_reserve(tp, 0, XFS_LINK_LOG_RES(mp), 0,
1057                                 XFS_TRANS_PERM_LOG_RES, XFS_LINK_LOG_COUNT);
1058         }
1059         if (error) {
1060                 cancel_flags = 0;
1061                 goto error_return;
1062         }
1063
1064         xfs_lock_two_inodes(sip, tdp, XFS_ILOCK_EXCL);
1065
1066         xfs_trans_ijoin(tp, sip, XFS_ILOCK_EXCL);
1067         xfs_trans_ijoin(tp, tdp, XFS_ILOCK_EXCL);
1068
1069         /*
1070          * If we are using project inheritance, we only allow hard link
1071          * creation in our tree when the project IDs are the same; else
1072          * the tree quota mechanism could be circumvented.
1073          */
1074         if (unlikely((tdp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
1075                      (xfs_get_projid(tdp) != xfs_get_projid(sip)))) {
1076                 error = XFS_ERROR(EXDEV);
1077                 goto error_return;
1078         }
1079
1080         error = xfs_dir_canenter(tp, tdp, target_name, resblks);
1081         if (error)
1082                 goto error_return;
1083
1084         xfs_bmap_init(&free_list, &first_block);
1085
1086         error = xfs_dir_createname(tp, tdp, target_name, sip->i_ino,
1087                                         &first_block, &free_list, resblks);
1088         if (error)
1089                 goto abort_return;
1090         xfs_trans_ichgtime(tp, tdp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1091         xfs_trans_log_inode(tp, tdp, XFS_ILOG_CORE);
1092
1093         error = xfs_bumplink(tp, sip);
1094         if (error)
1095                 goto abort_return;
1096
1097         /*
1098          * If this is a synchronous mount, make sure that the
1099          * link transaction goes to disk before returning to
1100          * the user.
1101          */
1102         if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
1103                 xfs_trans_set_sync(tp);
1104         }
1105
1106         error = xfs_bmap_finish (&tp, &free_list, &committed);
1107         if (error) {
1108                 xfs_bmap_cancel(&free_list);
1109                 goto abort_return;
1110         }
1111
1112         return xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
1113
1114  abort_return:
1115         cancel_flags |= XFS_TRANS_ABORT;
1116  error_return:
1117         xfs_trans_cancel(tp, cancel_flags);
1118  std_return:
1119         return error;
1120 }
1121
1122 int
1123 xfs_set_dmattrs(
1124         xfs_inode_t     *ip,
1125         u_int           evmask,
1126         u_int16_t       state)
1127 {
1128         xfs_mount_t     *mp = ip->i_mount;
1129         xfs_trans_t     *tp;
1130         int             error;
1131
1132         if (!capable(CAP_SYS_ADMIN))
1133                 return XFS_ERROR(EPERM);
1134
1135         if (XFS_FORCED_SHUTDOWN(mp))
1136                 return XFS_ERROR(EIO);
1137
1138         tp = xfs_trans_alloc(mp, XFS_TRANS_SET_DMATTRS);
1139         error = xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES (mp), 0, 0, 0);
1140         if (error) {
1141                 xfs_trans_cancel(tp, 0);
1142                 return error;
1143         }
1144         xfs_ilock(ip, XFS_ILOCK_EXCL);
1145         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
1146
1147         ip->i_d.di_dmevmask = evmask;
1148         ip->i_d.di_dmstate  = state;
1149
1150         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1151         error = xfs_trans_commit(tp, 0);
1152
1153         return error;
1154 }
1155
1156 /*
1157  * xfs_alloc_file_space()
1158  *      This routine allocates disk space for the given file.
1159  *
1160  *      If alloc_type == 0, this request is for an ALLOCSP type
1161  *      request which will change the file size.  In this case, no
1162  *      DMAPI event will be generated by the call.  A TRUNCATE event
1163  *      will be generated later by xfs_setattr.
1164  *
1165  *      If alloc_type != 0, this request is for a RESVSP type
1166  *      request, and a DMAPI DM_EVENT_WRITE will be generated if the
1167  *      lower block boundary byte address is less than the file's
1168  *      length.
1169  *
1170  * RETURNS:
1171  *       0 on success
1172  *      errno on error
1173  *
1174  */
1175 STATIC int
1176 xfs_alloc_file_space(
1177         xfs_inode_t             *ip,
1178         xfs_off_t               offset,
1179         xfs_off_t               len,
1180         int                     alloc_type,
1181         int                     attr_flags)
1182 {
1183         xfs_mount_t             *mp = ip->i_mount;
1184         xfs_off_t               count;
1185         xfs_filblks_t           allocated_fsb;
1186         xfs_filblks_t           allocatesize_fsb;
1187         xfs_extlen_t            extsz, temp;
1188         xfs_fileoff_t           startoffset_fsb;
1189         xfs_fsblock_t           firstfsb;
1190         int                     nimaps;
1191         int                     quota_flag;
1192         int                     rt;
1193         xfs_trans_t             *tp;
1194         xfs_bmbt_irec_t         imaps[1], *imapp;
1195         xfs_bmap_free_t         free_list;
1196         uint                    qblocks, resblks, resrtextents;
1197         int                     committed;
1198         int                     error;
1199
1200         trace_xfs_alloc_file_space(ip);
1201
1202         if (XFS_FORCED_SHUTDOWN(mp))
1203                 return XFS_ERROR(EIO);
1204
1205         error = xfs_qm_dqattach(ip, 0);
1206         if (error)
1207                 return error;
1208
1209         if (len <= 0)
1210                 return XFS_ERROR(EINVAL);
1211
1212         rt = XFS_IS_REALTIME_INODE(ip);
1213         extsz = xfs_get_extsz_hint(ip);
1214
1215         count = len;
1216         imapp = &imaps[0];
1217         nimaps = 1;
1218         startoffset_fsb = XFS_B_TO_FSBT(mp, offset);
1219         allocatesize_fsb = XFS_B_TO_FSB(mp, count);
1220
1221         /*
1222          * Allocate file space until done or until there is an error
1223          */
1224         while (allocatesize_fsb && !error) {
1225                 xfs_fileoff_t   s, e;
1226
1227                 /*
1228                  * Determine space reservations for data/realtime.
1229                  */
1230                 if (unlikely(extsz)) {
1231                         s = startoffset_fsb;
1232                         do_div(s, extsz);
1233                         s *= extsz;
1234                         e = startoffset_fsb + allocatesize_fsb;
1235                         if ((temp = do_mod(startoffset_fsb, extsz)))
1236                                 e += temp;
1237                         if ((temp = do_mod(e, extsz)))
1238                                 e += extsz - temp;
1239                 } else {
1240                         s = 0;
1241                         e = allocatesize_fsb;
1242                 }
1243
1244                 /*
1245                  * The transaction reservation is limited to a 32-bit block
1246                  * count, hence we need to limit the number of blocks we are
1247                  * trying to reserve to avoid an overflow. We can't allocate
1248                  * more than @nimaps extents, and an extent is limited on disk
1249                  * to MAXEXTLEN (21 bits), so use that to enforce the limit.
1250                  */
1251                 resblks = min_t(xfs_fileoff_t, (e - s), (MAXEXTLEN * nimaps));
1252                 if (unlikely(rt)) {
1253                         resrtextents = qblocks = resblks;
1254                         resrtextents /= mp->m_sb.sb_rextsize;
1255                         resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
1256                         quota_flag = XFS_QMOPT_RES_RTBLKS;
1257                 } else {
1258                         resrtextents = 0;
1259                         resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks);
1260                         quota_flag = XFS_QMOPT_RES_REGBLKS;
1261                 }
1262
1263                 /*
1264                  * Allocate and setup the transaction.
1265                  */
1266                 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
1267                 error = xfs_trans_reserve(tp, resblks,
1268                                           XFS_WRITE_LOG_RES(mp), resrtextents,
1269                                           XFS_TRANS_PERM_LOG_RES,
1270                                           XFS_WRITE_LOG_COUNT);
1271                 /*
1272                  * Check for running out of space
1273                  */
1274                 if (error) {
1275                         /*
1276                          * Free the transaction structure.
1277                          */
1278                         ASSERT(error == ENOSPC || XFS_FORCED_SHUTDOWN(mp));
1279                         xfs_trans_cancel(tp, 0);
1280                         break;
1281                 }
1282                 xfs_ilock(ip, XFS_ILOCK_EXCL);
1283                 error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks,
1284                                                       0, quota_flag);
1285                 if (error)
1286                         goto error1;
1287
1288                 xfs_trans_ijoin(tp, ip, 0);
1289
1290                 xfs_bmap_init(&free_list, &firstfsb);
1291                 error = xfs_bmapi_write(tp, ip, startoffset_fsb,
1292                                         allocatesize_fsb, alloc_type, &firstfsb,
1293                                         0, imapp, &nimaps, &free_list);
1294                 if (error) {
1295                         goto error0;
1296                 }
1297
1298                 /*
1299                  * Complete the transaction
1300                  */
1301                 error = xfs_bmap_finish(&tp, &free_list, &committed);
1302                 if (error) {
1303                         goto error0;
1304                 }
1305
1306                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
1307                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1308                 if (error) {
1309                         break;
1310                 }
1311
1312                 allocated_fsb = imapp->br_blockcount;
1313
1314                 if (nimaps == 0) {
1315                         error = XFS_ERROR(ENOSPC);
1316                         break;
1317                 }
1318
1319                 startoffset_fsb += allocated_fsb;
1320                 allocatesize_fsb -= allocated_fsb;
1321         }
1322
1323         return error;
1324
1325 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
1326         xfs_bmap_cancel(&free_list);
1327         xfs_trans_unreserve_quota_nblks(tp, ip, (long)qblocks, 0, quota_flag);
1328
1329 error1: /* Just cancel transaction */
1330         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
1331         xfs_iunlock(ip, XFS_ILOCK_EXCL);
1332         return error;
1333 }
1334
1335 /*
1336  * Zero file bytes between startoff and endoff inclusive.
1337  * The iolock is held exclusive and no blocks are buffered.
1338  *
1339  * This function is used by xfs_free_file_space() to zero
1340  * partial blocks when the range to free is not block aligned.
1341  * When unreserving space with boundaries that are not block
1342  * aligned we round up the start and round down the end
1343  * boundaries and then use this function to zero the parts of
1344  * the blocks that got dropped during the rounding.
1345  */
1346 STATIC int
1347 xfs_zero_remaining_bytes(
1348         xfs_inode_t             *ip,
1349         xfs_off_t               startoff,
1350         xfs_off_t               endoff)
1351 {
1352         xfs_bmbt_irec_t         imap;
1353         xfs_fileoff_t           offset_fsb;
1354         xfs_off_t               lastoffset;
1355         xfs_off_t               offset;
1356         xfs_buf_t               *bp;
1357         xfs_mount_t             *mp = ip->i_mount;
1358         int                     nimap;
1359         int                     error = 0;
1360
1361         /*
1362          * Avoid doing I/O beyond eof - it's not necessary
1363          * since nothing can read beyond eof.  The space will
1364          * be zeroed when the file is extended anyway.
1365          */
1366         if (startoff >= XFS_ISIZE(ip))
1367                 return 0;
1368
1369         if (endoff > XFS_ISIZE(ip))
1370                 endoff = XFS_ISIZE(ip);
1371
1372         bp = xfs_buf_get_uncached(XFS_IS_REALTIME_INODE(ip) ?
1373                                         mp->m_rtdev_targp : mp->m_ddev_targp,
1374                                   BTOBB(mp->m_sb.sb_blocksize), 0);
1375         if (!bp)
1376                 return XFS_ERROR(ENOMEM);
1377
1378         xfs_buf_unlock(bp);
1379
1380         for (offset = startoff; offset <= endoff; offset = lastoffset + 1) {
1381                 offset_fsb = XFS_B_TO_FSBT(mp, offset);
1382                 nimap = 1;
1383                 error = xfs_bmapi_read(ip, offset_fsb, 1, &imap, &nimap, 0);
1384                 if (error || nimap < 1)
1385                         break;
1386                 ASSERT(imap.br_blockcount >= 1);
1387                 ASSERT(imap.br_startoff == offset_fsb);
1388                 lastoffset = XFS_FSB_TO_B(mp, imap.br_startoff + 1) - 1;
1389                 if (lastoffset > endoff)
1390                         lastoffset = endoff;
1391                 if (imap.br_startblock == HOLESTARTBLOCK)
1392                         continue;
1393                 ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
1394                 if (imap.br_state == XFS_EXT_UNWRITTEN)
1395                         continue;
1396                 XFS_BUF_UNDONE(bp);
1397                 XFS_BUF_UNWRITE(bp);
1398                 XFS_BUF_READ(bp);
1399                 XFS_BUF_SET_ADDR(bp, xfs_fsb_to_db(ip, imap.br_startblock));
1400                 xfsbdstrat(mp, bp);
1401                 error = xfs_buf_iowait(bp);
1402                 if (error) {
1403                         xfs_buf_ioerror_alert(bp,
1404                                         "xfs_zero_remaining_bytes(read)");
1405                         break;
1406                 }
1407                 memset(bp->b_addr +
1408                         (offset - XFS_FSB_TO_B(mp, imap.br_startoff)),
1409                       0, lastoffset - offset + 1);
1410                 XFS_BUF_UNDONE(bp);
1411                 XFS_BUF_UNREAD(bp);
1412                 XFS_BUF_WRITE(bp);
1413                 xfsbdstrat(mp, bp);
1414                 error = xfs_buf_iowait(bp);
1415                 if (error) {
1416                         xfs_buf_ioerror_alert(bp,
1417                                         "xfs_zero_remaining_bytes(write)");
1418                         break;
1419                 }
1420         }
1421         xfs_buf_free(bp);
1422         return error;
1423 }
1424
1425 /*
1426  * xfs_free_file_space()
1427  *      This routine frees disk space for the given file.
1428  *
1429  *      This routine is only called by xfs_change_file_space
1430  *      for an UNRESVSP type call.
1431  *
1432  * RETURNS:
1433  *       0 on success
1434  *      errno on error
1435  *
1436  */
1437 STATIC int
1438 xfs_free_file_space(
1439         xfs_inode_t             *ip,
1440         xfs_off_t               offset,
1441         xfs_off_t               len,
1442         int                     attr_flags)
1443 {
1444         int                     committed;
1445         int                     done;
1446         xfs_fileoff_t           endoffset_fsb;
1447         int                     error;
1448         xfs_fsblock_t           firstfsb;
1449         xfs_bmap_free_t         free_list;
1450         xfs_bmbt_irec_t         imap;
1451         xfs_off_t               ioffset;
1452         xfs_extlen_t            mod=0;
1453         xfs_mount_t             *mp;
1454         int                     nimap;
1455         uint                    resblks;
1456         uint                    rounding;
1457         int                     rt;
1458         xfs_fileoff_t           startoffset_fsb;
1459         xfs_trans_t             *tp;
1460         int                     need_iolock = 1;
1461
1462         mp = ip->i_mount;
1463
1464         trace_xfs_free_file_space(ip);
1465
1466         error = xfs_qm_dqattach(ip, 0);
1467         if (error)
1468                 return error;
1469
1470         error = 0;
1471         if (len <= 0)   /* if nothing being freed */
1472                 return error;
1473         rt = XFS_IS_REALTIME_INODE(ip);
1474         startoffset_fsb = XFS_B_TO_FSB(mp, offset);
1475         endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
1476
1477         if (attr_flags & XFS_ATTR_NOLOCK)
1478                 need_iolock = 0;
1479         if (need_iolock) {
1480                 xfs_ilock(ip, XFS_IOLOCK_EXCL);
1481                 /* wait for the completion of any pending DIOs */
1482                 inode_dio_wait(VFS_I(ip));
1483         }
1484
1485         rounding = max_t(uint, 1 << mp->m_sb.sb_blocklog, PAGE_CACHE_SIZE);
1486         ioffset = offset & ~(rounding - 1);
1487         error = -filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
1488                                               ioffset, -1);
1489         if (error)
1490                 goto out_unlock_iolock;
1491         truncate_pagecache_range(VFS_I(ip), ioffset, -1);
1492
1493         /*
1494          * Need to zero the stuff we're not freeing, on disk.
1495          * If it's a realtime file & can't use unwritten extents then we
1496          * actually need to zero the extent edges.  Otherwise xfs_bunmapi
1497          * will take care of it for us.
1498          */
1499         if (rt && !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
1500                 nimap = 1;
1501                 error = xfs_bmapi_read(ip, startoffset_fsb, 1,
1502                                         &imap, &nimap, 0);
1503                 if (error)
1504                         goto out_unlock_iolock;
1505                 ASSERT(nimap == 0 || nimap == 1);
1506                 if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
1507                         xfs_daddr_t     block;
1508
1509                         ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
1510                         block = imap.br_startblock;
1511                         mod = do_div(block, mp->m_sb.sb_rextsize);
1512                         if (mod)
1513                                 startoffset_fsb += mp->m_sb.sb_rextsize - mod;
1514                 }
1515                 nimap = 1;
1516                 error = xfs_bmapi_read(ip, endoffset_fsb - 1, 1,
1517                                         &imap, &nimap, 0);
1518                 if (error)
1519                         goto out_unlock_iolock;
1520                 ASSERT(nimap == 0 || nimap == 1);
1521                 if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
1522                         ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
1523                         mod++;
1524                         if (mod && (mod != mp->m_sb.sb_rextsize))
1525                                 endoffset_fsb -= mod;
1526                 }
1527         }
1528         if ((done = (endoffset_fsb <= startoffset_fsb)))
1529                 /*
1530                  * One contiguous piece to clear
1531                  */
1532                 error = xfs_zero_remaining_bytes(ip, offset, offset + len - 1);
1533         else {
1534                 /*
1535                  * Some full blocks, possibly two pieces to clear
1536                  */
1537                 if (offset < XFS_FSB_TO_B(mp, startoffset_fsb))
1538                         error = xfs_zero_remaining_bytes(ip, offset,
1539                                 XFS_FSB_TO_B(mp, startoffset_fsb) - 1);
1540                 if (!error &&
1541                     XFS_FSB_TO_B(mp, endoffset_fsb) < offset + len)
1542                         error = xfs_zero_remaining_bytes(ip,
1543                                 XFS_FSB_TO_B(mp, endoffset_fsb),
1544                                 offset + len - 1);
1545         }
1546
1547         /*
1548          * free file space until done or until there is an error
1549          */
1550         resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
1551         while (!error && !done) {
1552
1553                 /*
1554                  * allocate and setup the transaction. Allow this
1555                  * transaction to dip into the reserve blocks to ensure
1556                  * the freeing of the space succeeds at ENOSPC.
1557                  */
1558                 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
1559                 tp->t_flags |= XFS_TRANS_RESERVE;
1560                 error = xfs_trans_reserve(tp,
1561                                           resblks,
1562                                           XFS_WRITE_LOG_RES(mp),
1563                                           0,
1564                                           XFS_TRANS_PERM_LOG_RES,
1565                                           XFS_WRITE_LOG_COUNT);
1566
1567                 /*
1568                  * check for running out of space
1569                  */
1570                 if (error) {
1571                         /*
1572                          * Free the transaction structure.
1573                          */
1574                         ASSERT(error == ENOSPC || XFS_FORCED_SHUTDOWN(mp));
1575                         xfs_trans_cancel(tp, 0);
1576                         break;
1577                 }
1578                 xfs_ilock(ip, XFS_ILOCK_EXCL);
1579                 error = xfs_trans_reserve_quota(tp, mp,
1580                                 ip->i_udquot, ip->i_gdquot,
1581                                 resblks, 0, XFS_QMOPT_RES_REGBLKS);
1582                 if (error)
1583                         goto error1;
1584
1585                 xfs_trans_ijoin(tp, ip, 0);
1586
1587                 /*
1588                  * issue the bunmapi() call to free the blocks
1589                  */
1590                 xfs_bmap_init(&free_list, &firstfsb);
1591                 error = xfs_bunmapi(tp, ip, startoffset_fsb,
1592                                   endoffset_fsb - startoffset_fsb,
1593                                   0, 2, &firstfsb, &free_list, &done);
1594                 if (error) {
1595                         goto error0;
1596                 }
1597
1598                 /*
1599                  * complete the transaction
1600                  */
1601                 error = xfs_bmap_finish(&tp, &free_list, &committed);
1602                 if (error) {
1603                         goto error0;
1604                 }
1605
1606                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
1607                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1608         }
1609
1610  out_unlock_iolock:
1611         if (need_iolock)
1612                 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1613         return error;
1614
1615  error0:
1616         xfs_bmap_cancel(&free_list);
1617  error1:
1618         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
1619         xfs_iunlock(ip, need_iolock ? (XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL) :
1620                     XFS_ILOCK_EXCL);
1621         return error;
1622 }
1623
1624
1625 STATIC int
1626 xfs_zero_file_space(
1627         struct xfs_inode        *ip,
1628         xfs_off_t               offset,
1629         xfs_off_t               len,
1630         int                     attr_flags)
1631 {
1632         struct xfs_mount        *mp = ip->i_mount;
1633         uint                    granularity;
1634         xfs_off_t               start_boundary;
1635         xfs_off_t               end_boundary;
1636         int                     error;
1637
1638         granularity = max_t(uint, 1 << mp->m_sb.sb_blocklog, PAGE_CACHE_SIZE);
1639
1640         /*
1641          * Round the range of extents we are going to convert inwards.  If the
1642          * offset is aligned, then it doesn't get changed so we zero from the
1643          * start of the block offset points to.
1644          */
1645         start_boundary = round_up(offset, granularity);
1646         end_boundary = round_down(offset + len, granularity);
1647
1648         ASSERT(start_boundary >= offset);
1649         ASSERT(end_boundary <= offset + len);
1650
1651         if (!(attr_flags & XFS_ATTR_NOLOCK))
1652                 xfs_ilock(ip, XFS_IOLOCK_EXCL);
1653
1654         if (start_boundary < end_boundary - 1) {
1655                 /* punch out the page cache over the conversion range */
1656                 truncate_pagecache_range(VFS_I(ip), start_boundary,
1657                                          end_boundary - 1);
1658                 /* convert the blocks */
1659                 error = xfs_alloc_file_space(ip, start_boundary,
1660                                         end_boundary - start_boundary - 1,
1661                                         XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT,
1662                                         attr_flags);
1663                 if (error)
1664                         goto out_unlock;
1665
1666                 /* We've handled the interior of the range, now for the edges */
1667                 if (start_boundary != offset)
1668                         error = xfs_iozero(ip, offset, start_boundary - offset);
1669                 if (error)
1670                         goto out_unlock;
1671
1672                 if (end_boundary != offset + len)
1673                         error = xfs_iozero(ip, end_boundary,
1674                                            offset + len - end_boundary);
1675
1676         } else {
1677                 /*
1678                  * It's either a sub-granularity range or the range spanned lies
1679                  * partially across two adjacent blocks.
1680                  */
1681                 error = xfs_iozero(ip, offset, len);
1682         }
1683
1684 out_unlock:
1685         if (!(attr_flags & XFS_ATTR_NOLOCK))
1686                 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1687         return error;
1688
1689 }
1690
1691 /*
1692  * xfs_change_file_space()
1693  *      This routine allocates or frees disk space for the given file.
1694  *      The user specified parameters are checked for alignment and size
1695  *      limitations.
1696  *
1697  * RETURNS:
1698  *       0 on success
1699  *      errno on error
1700  *
1701  */
1702 int
1703 xfs_change_file_space(
1704         xfs_inode_t     *ip,
1705         int             cmd,
1706         xfs_flock64_t   *bf,
1707         xfs_off_t       offset,
1708         int             attr_flags)
1709 {
1710         xfs_mount_t     *mp = ip->i_mount;
1711         int             clrprealloc;
1712         int             error;
1713         xfs_fsize_t     fsize;
1714         int             setprealloc;
1715         xfs_off_t       startoffset;
1716         xfs_trans_t     *tp;
1717         struct iattr    iattr;
1718
1719         if (!S_ISREG(ip->i_d.di_mode))
1720                 return XFS_ERROR(EINVAL);
1721
1722         switch (bf->l_whence) {
1723         case 0: /*SEEK_SET*/
1724                 break;
1725         case 1: /*SEEK_CUR*/
1726                 bf->l_start += offset;
1727                 break;
1728         case 2: /*SEEK_END*/
1729                 bf->l_start += XFS_ISIZE(ip);
1730                 break;
1731         default:
1732                 return XFS_ERROR(EINVAL);
1733         }
1734
1735         /*
1736          * length of <= 0 for resv/unresv/zero is invalid.  length for
1737          * alloc/free is ignored completely and we have no idea what userspace
1738          * might have set it to, so set it to zero to allow range
1739          * checks to pass.
1740          */
1741         switch (cmd) {
1742         case XFS_IOC_ZERO_RANGE:
1743         case XFS_IOC_RESVSP:
1744         case XFS_IOC_RESVSP64:
1745         case XFS_IOC_UNRESVSP:
1746         case XFS_IOC_UNRESVSP64:
1747                 if (bf->l_len <= 0)
1748                         return XFS_ERROR(EINVAL);
1749                 break;
1750         default:
1751                 bf->l_len = 0;
1752                 break;
1753         }
1754
1755         if (bf->l_start < 0 ||
1756             bf->l_start > mp->m_super->s_maxbytes ||
1757             bf->l_start + bf->l_len < 0 ||
1758             bf->l_start + bf->l_len >= mp->m_super->s_maxbytes)
1759                 return XFS_ERROR(EINVAL);
1760
1761         bf->l_whence = 0;
1762
1763         startoffset = bf->l_start;
1764         fsize = XFS_ISIZE(ip);
1765
1766         setprealloc = clrprealloc = 0;
1767         switch (cmd) {
1768         case XFS_IOC_ZERO_RANGE:
1769                 error = xfs_zero_file_space(ip, startoffset, bf->l_len,
1770                                                 attr_flags);
1771                 if (error)
1772                         return error;
1773                 setprealloc = 1;
1774                 break;
1775
1776         case XFS_IOC_RESVSP:
1777         case XFS_IOC_RESVSP64:
1778                 error = xfs_alloc_file_space(ip, startoffset, bf->l_len,
1779                                                 XFS_BMAPI_PREALLOC, attr_flags);
1780                 if (error)
1781                         return error;
1782                 setprealloc = 1;
1783                 break;
1784
1785         case XFS_IOC_UNRESVSP:
1786         case XFS_IOC_UNRESVSP64:
1787                 if ((error = xfs_free_file_space(ip, startoffset, bf->l_len,
1788                                                                 attr_flags)))
1789                         return error;
1790                 break;
1791
1792         case XFS_IOC_ALLOCSP:
1793         case XFS_IOC_ALLOCSP64:
1794         case XFS_IOC_FREESP:
1795         case XFS_IOC_FREESP64:
1796                 /*
1797                  * These operations actually do IO when extending the file, but
1798                  * the allocation is done seperately to the zeroing that is
1799                  * done. This set of operations need to be serialised against
1800                  * other IO operations, such as truncate and buffered IO. We
1801                  * need to take the IOLOCK here to serialise the allocation and
1802                  * zeroing IO to prevent other IOLOCK holders (e.g. getbmap,
1803                  * truncate, direct IO) from racing against the transient
1804                  * allocated but not written state we can have here.
1805                  */
1806                 xfs_ilock(ip, XFS_IOLOCK_EXCL);
1807                 if (startoffset > fsize) {
1808                         error = xfs_alloc_file_space(ip, fsize,
1809                                         startoffset - fsize, 0,
1810                                         attr_flags | XFS_ATTR_NOLOCK);
1811                         if (error) {
1812                                 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1813                                 break;
1814                         }
1815                 }
1816
1817                 iattr.ia_valid = ATTR_SIZE;
1818                 iattr.ia_size = startoffset;
1819
1820                 error = xfs_setattr_size(ip, &iattr,
1821                                          attr_flags | XFS_ATTR_NOLOCK);
1822                 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1823
1824                 if (error)
1825                         return error;
1826
1827                 clrprealloc = 1;
1828                 break;
1829
1830         default:
1831                 ASSERT(0);
1832                 return XFS_ERROR(EINVAL);
1833         }
1834
1835         /*
1836          * update the inode timestamp, mode, and prealloc flag bits
1837          */
1838         tp = xfs_trans_alloc(mp, XFS_TRANS_WRITEID);
1839
1840         if ((error = xfs_trans_reserve(tp, 0, XFS_WRITEID_LOG_RES(mp),
1841                                       0, 0, 0))) {
1842                 /* ASSERT(0); */
1843                 xfs_trans_cancel(tp, 0);
1844                 return error;
1845         }
1846
1847         xfs_ilock(ip, XFS_ILOCK_EXCL);
1848         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
1849
1850         if ((attr_flags & XFS_ATTR_DMI) == 0) {
1851                 ip->i_d.di_mode &= ~S_ISUID;
1852
1853                 /*
1854                  * Note that we don't have to worry about mandatory
1855                  * file locking being disabled here because we only
1856                  * clear the S_ISGID bit if the Group execute bit is
1857                  * on, but if it was on then mandatory locking wouldn't
1858                  * have been enabled.
1859                  */
1860                 if (ip->i_d.di_mode & S_IXGRP)
1861                         ip->i_d.di_mode &= ~S_ISGID;
1862
1863                 xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1864         }
1865         if (setprealloc)
1866                 ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;
1867         else if (clrprealloc)
1868                 ip->i_d.di_flags &= ~XFS_DIFLAG_PREALLOC;
1869
1870         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1871         if (attr_flags & XFS_ATTR_SYNC)
1872                 xfs_trans_set_sync(tp);
1873         return xfs_trans_commit(tp, 0);
1874 }