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