linux/fs/xfs/xfs_symlink.c
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   1/*
   2 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
   3 * Copyright (c) 2012-2013 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#include "xfs.h"
  20#include "xfs_fs.h"
  21#include "xfs_types.h"
  22#include "xfs_bit.h"
  23#include "xfs_log.h"
  24#include "xfs_trans.h"
  25#include "xfs_sb.h"
  26#include "xfs_ag.h"
  27#include "xfs_dir2.h"
  28#include "xfs_mount.h"
  29#include "xfs_da_btree.h"
  30#include "xfs_bmap_btree.h"
  31#include "xfs_ialloc_btree.h"
  32#include "xfs_dinode.h"
  33#include "xfs_inode.h"
  34#include "xfs_inode_item.h"
  35#include "xfs_itable.h"
  36#include "xfs_ialloc.h"
  37#include "xfs_alloc.h"
  38#include "xfs_bmap.h"
  39#include "xfs_error.h"
  40#include "xfs_quota.h"
  41#include "xfs_utils.h"
  42#include "xfs_trans_space.h"
  43#include "xfs_log_priv.h"
  44#include "xfs_trace.h"
  45#include "xfs_symlink.h"
  46#include "xfs_cksum.h"
  47#include "xfs_buf_item.h"
  48
  49
  50/*
  51 * Each contiguous block has a header, so it is not just a simple pathlen
  52 * to FSB conversion.
  53 */
  54int
  55xfs_symlink_blocks(
  56        struct xfs_mount *mp,
  57        int             pathlen)
  58{
  59        int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
  60
  61        return (pathlen + buflen - 1) / buflen;
  62}
  63
  64static int
  65xfs_symlink_hdr_set(
  66        struct xfs_mount        *mp,
  67        xfs_ino_t               ino,
  68        uint32_t                offset,
  69        uint32_t                size,
  70        struct xfs_buf          *bp)
  71{
  72        struct xfs_dsymlink_hdr *dsl = bp->b_addr;
  73
  74        if (!xfs_sb_version_hascrc(&mp->m_sb))
  75                return 0;
  76
  77        dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
  78        dsl->sl_offset = cpu_to_be32(offset);
  79        dsl->sl_bytes = cpu_to_be32(size);
  80        uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_uuid);
  81        dsl->sl_owner = cpu_to_be64(ino);
  82        dsl->sl_blkno = cpu_to_be64(bp->b_bn);
  83        bp->b_ops = &xfs_symlink_buf_ops;
  84
  85        return sizeof(struct xfs_dsymlink_hdr);
  86}
  87
  88/*
  89 * Checking of the symlink header is split into two parts. the verifier does
  90 * CRC, location and bounds checking, the unpacking function checks the path
  91 * parameters and owner.
  92 */
  93bool
  94xfs_symlink_hdr_ok(
  95        struct xfs_mount        *mp,
  96        xfs_ino_t               ino,
  97        uint32_t                offset,
  98        uint32_t                size,
  99        struct xfs_buf          *bp)
 100{
 101        struct xfs_dsymlink_hdr *dsl = bp->b_addr;
 102
 103        if (offset != be32_to_cpu(dsl->sl_offset))
 104                return false;
 105        if (size != be32_to_cpu(dsl->sl_bytes))
 106                return false;
 107        if (ino != be64_to_cpu(dsl->sl_owner))
 108                return false;
 109
 110        /* ok */
 111        return true;
 112}
 113
 114static bool
 115xfs_symlink_verify(
 116        struct xfs_buf          *bp)
 117{
 118        struct xfs_mount        *mp = bp->b_target->bt_mount;
 119        struct xfs_dsymlink_hdr *dsl = bp->b_addr;
 120
 121        if (!xfs_sb_version_hascrc(&mp->m_sb))
 122                return false;
 123        if (dsl->sl_magic != cpu_to_be32(XFS_SYMLINK_MAGIC))
 124                return false;
 125        if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_uuid))
 126                return false;
 127        if (bp->b_bn != be64_to_cpu(dsl->sl_blkno))
 128                return false;
 129        if (be32_to_cpu(dsl->sl_offset) +
 130                                be32_to_cpu(dsl->sl_bytes) >= MAXPATHLEN)
 131                return false;
 132        if (dsl->sl_owner == 0)
 133                return false;
 134
 135        return true;
 136}
 137
 138static void
 139xfs_symlink_read_verify(
 140        struct xfs_buf  *bp)
 141{
 142        struct xfs_mount *mp = bp->b_target->bt_mount;
 143
 144        /* no verification of non-crc buffers */
 145        if (!xfs_sb_version_hascrc(&mp->m_sb))
 146                return;
 147
 148        if (!xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
 149                                  offsetof(struct xfs_dsymlink_hdr, sl_crc)) ||
 150            !xfs_symlink_verify(bp)) {
 151                XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
 152                xfs_buf_ioerror(bp, EFSCORRUPTED);
 153        }
 154}
 155
 156static void
 157xfs_symlink_write_verify(
 158        struct xfs_buf  *bp)
 159{
 160        struct xfs_mount *mp = bp->b_target->bt_mount;
 161        struct xfs_buf_log_item *bip = bp->b_fspriv;
 162
 163        /* no verification of non-crc buffers */
 164        if (!xfs_sb_version_hascrc(&mp->m_sb))
 165                return;
 166
 167        if (!xfs_symlink_verify(bp)) {
 168                XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
 169                xfs_buf_ioerror(bp, EFSCORRUPTED);
 170                return;
 171        }
 172
 173        if (bip) {
 174                struct xfs_dsymlink_hdr *dsl = bp->b_addr;
 175                dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
 176        }
 177        xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
 178                         offsetof(struct xfs_dsymlink_hdr, sl_crc));
 179}
 180
 181const struct xfs_buf_ops xfs_symlink_buf_ops = {
 182        .verify_read = xfs_symlink_read_verify,
 183        .verify_write = xfs_symlink_write_verify,
 184};
 185
 186void
 187xfs_symlink_local_to_remote(
 188        struct xfs_trans        *tp,
 189        struct xfs_buf          *bp,
 190        struct xfs_inode        *ip,
 191        struct xfs_ifork        *ifp)
 192{
 193        struct xfs_mount        *mp = ip->i_mount;
 194        char                    *buf;
 195
 196        if (!xfs_sb_version_hascrc(&mp->m_sb)) {
 197                bp->b_ops = NULL;
 198                memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
 199                return;
 200        }
 201
 202        /*
 203         * As this symlink fits in an inode literal area, it must also fit in
 204         * the smallest buffer the filesystem supports.
 205         */
 206        ASSERT(BBTOB(bp->b_length) >=
 207                        ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));
 208
 209        bp->b_ops = &xfs_symlink_buf_ops;
 210
 211        buf = bp->b_addr;
 212        buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
 213        memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
 214}
 215
 216/* ----- Kernel only functions below ----- */
 217STATIC int
 218xfs_readlink_bmap(
 219        struct xfs_inode        *ip,
 220        char                    *link)
 221{
 222        struct xfs_mount        *mp = ip->i_mount;
 223        struct xfs_bmbt_irec    mval[XFS_SYMLINK_MAPS];
 224        struct xfs_buf          *bp;
 225        xfs_daddr_t             d;
 226        char                    *cur_chunk;
 227        int                     pathlen = ip->i_d.di_size;
 228        int                     nmaps = XFS_SYMLINK_MAPS;
 229        int                     byte_cnt;
 230        int                     n;
 231        int                     error = 0;
 232        int                     fsblocks = 0;
 233        int                     offset;
 234
 235        fsblocks = xfs_symlink_blocks(mp, pathlen);
 236        error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
 237        if (error)
 238                goto out;
 239
 240        offset = 0;
 241        for (n = 0; n < nmaps; n++) {
 242                d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
 243                byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
 244
 245                bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
 246                                  &xfs_symlink_buf_ops);
 247                if (!bp)
 248                        return XFS_ERROR(ENOMEM);
 249                error = bp->b_error;
 250                if (error) {
 251                        xfs_buf_ioerror_alert(bp, __func__);
 252                        xfs_buf_relse(bp);
 253                        goto out;
 254                }
 255                byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
 256                if (pathlen < byte_cnt)
 257                        byte_cnt = pathlen;
 258
 259                cur_chunk = bp->b_addr;
 260                if (xfs_sb_version_hascrc(&mp->m_sb)) {
 261                        if (!xfs_symlink_hdr_ok(mp, ip->i_ino, offset,
 262                                                        byte_cnt, bp)) {
 263                                error = EFSCORRUPTED;
 264                                xfs_alert(mp,
 265"symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
 266                                        offset, byte_cnt, ip->i_ino);
 267                                xfs_buf_relse(bp);
 268                                goto out;
 269
 270                        }
 271
 272                        cur_chunk += sizeof(struct xfs_dsymlink_hdr);
 273                }
 274
 275                memcpy(link + offset, bp->b_addr, byte_cnt);
 276
 277                pathlen -= byte_cnt;
 278                offset += byte_cnt;
 279
 280                xfs_buf_relse(bp);
 281        }
 282        ASSERT(pathlen == 0);
 283
 284        link[ip->i_d.di_size] = '\0';
 285        error = 0;
 286
 287 out:
 288        return error;
 289}
 290
 291int
 292xfs_readlink(
 293        struct xfs_inode *ip,
 294        char            *link)
 295{
 296        struct xfs_mount *mp = ip->i_mount;
 297        xfs_fsize_t     pathlen;
 298        int             error = 0;
 299
 300        trace_xfs_readlink(ip);
 301
 302        if (XFS_FORCED_SHUTDOWN(mp))
 303                return XFS_ERROR(EIO);
 304
 305        xfs_ilock(ip, XFS_ILOCK_SHARED);
 306
 307        pathlen = ip->i_d.di_size;
 308        if (!pathlen)
 309                goto out;
 310
 311        if (pathlen < 0 || pathlen > MAXPATHLEN) {
 312                xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
 313                         __func__, (unsigned long long) ip->i_ino,
 314                         (long long) pathlen);
 315                ASSERT(0);
 316                error = XFS_ERROR(EFSCORRUPTED);
 317                goto out;
 318        }
 319
 320
 321        if (ip->i_df.if_flags & XFS_IFINLINE) {
 322                memcpy(link, ip->i_df.if_u1.if_data, pathlen);
 323                link[pathlen] = '\0';
 324        } else {
 325                error = xfs_readlink_bmap(ip, link);
 326        }
 327
 328 out:
 329        xfs_iunlock(ip, XFS_ILOCK_SHARED);
 330        return error;
 331}
 332
 333int
 334xfs_symlink(
 335        struct xfs_inode        *dp,
 336        struct xfs_name         *link_name,
 337        const char              *target_path,
 338        umode_t                 mode,
 339        struct xfs_inode        **ipp)
 340{
 341        struct xfs_mount        *mp = dp->i_mount;
 342        struct xfs_trans        *tp = NULL;
 343        struct xfs_inode        *ip = NULL;
 344        int                     error = 0;
 345        int                     pathlen;
 346        struct xfs_bmap_free    free_list;
 347        xfs_fsblock_t           first_block;
 348        bool                    unlock_dp_on_error = false;
 349        uint                    cancel_flags;
 350        int                     committed;
 351        xfs_fileoff_t           first_fsb;
 352        xfs_filblks_t           fs_blocks;
 353        int                     nmaps;
 354        struct xfs_bmbt_irec    mval[XFS_SYMLINK_MAPS];
 355        xfs_daddr_t             d;
 356        const char              *cur_chunk;
 357        int                     byte_cnt;
 358        int                     n;
 359        xfs_buf_t               *bp;
 360        prid_t                  prid;
 361        struct xfs_dquot        *udqp = NULL;
 362        struct xfs_dquot        *gdqp = NULL;
 363        struct xfs_dquot        *pdqp = NULL;
 364        uint                    resblks;
 365
 366        *ipp = NULL;
 367
 368        trace_xfs_symlink(dp, link_name);
 369
 370        if (XFS_FORCED_SHUTDOWN(mp))
 371                return XFS_ERROR(EIO);
 372
 373        /*
 374         * Check component lengths of the target path name.
 375         */
 376        pathlen = strlen(target_path);
 377        if (pathlen >= MAXPATHLEN)      /* total string too long */
 378                return XFS_ERROR(ENAMETOOLONG);
 379
 380        udqp = gdqp = NULL;
 381        if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
 382                prid = xfs_get_projid(dp);
 383        else
 384                prid = XFS_PROJID_DEFAULT;
 385
 386        /*
 387         * Make sure that we have allocated dquot(s) on disk.
 388         */
 389        error = xfs_qm_vop_dqalloc(dp, current_fsuid(), current_fsgid(), prid,
 390                XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT, &udqp, &gdqp, &pdqp);
 391        if (error)
 392                goto std_return;
 393
 394        tp = xfs_trans_alloc(mp, XFS_TRANS_SYMLINK);
 395        cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
 396        /*
 397         * The symlink will fit into the inode data fork?
 398         * There can't be any attributes so we get the whole variable part.
 399         */
 400        if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version))
 401                fs_blocks = 0;
 402        else
 403                fs_blocks = xfs_symlink_blocks(mp, pathlen);
 404        resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
 405        error = xfs_trans_reserve(tp, resblks, XFS_SYMLINK_LOG_RES(mp), 0,
 406                        XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
 407        if (error == ENOSPC && fs_blocks == 0) {
 408                resblks = 0;
 409                error = xfs_trans_reserve(tp, 0, XFS_SYMLINK_LOG_RES(mp), 0,
 410                                XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
 411        }
 412        if (error) {
 413                cancel_flags = 0;
 414                goto error_return;
 415        }
 416
 417        xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
 418        unlock_dp_on_error = true;
 419
 420        /*
 421         * Check whether the directory allows new symlinks or not.
 422         */
 423        if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
 424                error = XFS_ERROR(EPERM);
 425                goto error_return;
 426        }
 427
 428        /*
 429         * Reserve disk quota : blocks and inode.
 430         */
 431        error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
 432                                                pdqp, resblks, 1, 0);
 433        if (error)
 434                goto error_return;
 435
 436        /*
 437         * Check for ability to enter directory entry, if no space reserved.
 438         */
 439        error = xfs_dir_canenter(tp, dp, link_name, resblks);
 440        if (error)
 441                goto error_return;
 442        /*
 443         * Initialize the bmap freelist prior to calling either
 444         * bmapi or the directory create code.
 445         */
 446        xfs_bmap_init(&free_list, &first_block);
 447
 448        /*
 449         * Allocate an inode for the symlink.
 450         */
 451        error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT), 1, 0,
 452                               prid, resblks > 0, &ip, NULL);
 453        if (error) {
 454                if (error == ENOSPC)
 455                        goto error_return;
 456                goto error1;
 457        }
 458
 459        /*
 460         * An error after we've joined dp to the transaction will result in the
 461         * transaction cancel unlocking dp so don't do it explicitly in the
 462         * error path.
 463         */
 464        xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
 465        unlock_dp_on_error = false;
 466
 467        /*
 468         * Also attach the dquot(s) to it, if applicable.
 469         */
 470        xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
 471
 472        if (resblks)
 473                resblks -= XFS_IALLOC_SPACE_RES(mp);
 474        /*
 475         * If the symlink will fit into the inode, write it inline.
 476         */
 477        if (pathlen <= XFS_IFORK_DSIZE(ip)) {
 478                xfs_idata_realloc(ip, pathlen, XFS_DATA_FORK);
 479                memcpy(ip->i_df.if_u1.if_data, target_path, pathlen);
 480                ip->i_d.di_size = pathlen;
 481
 482                /*
 483                 * The inode was initially created in extent format.
 484                 */
 485                ip->i_df.if_flags &= ~(XFS_IFEXTENTS | XFS_IFBROOT);
 486                ip->i_df.if_flags |= XFS_IFINLINE;
 487
 488                ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
 489                xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
 490
 491        } else {
 492                int     offset;
 493
 494                first_fsb = 0;
 495                nmaps = XFS_SYMLINK_MAPS;
 496
 497                error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
 498                                  XFS_BMAPI_METADATA, &first_block, resblks,
 499                                  mval, &nmaps, &free_list);
 500                if (error)
 501                        goto error2;
 502
 503                if (resblks)
 504                        resblks -= fs_blocks;
 505                ip->i_d.di_size = pathlen;
 506                xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 507
 508                cur_chunk = target_path;
 509                offset = 0;
 510                for (n = 0; n < nmaps; n++) {
 511                        char    *buf;
 512
 513                        d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
 514                        byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
 515                        bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
 516                                               BTOBB(byte_cnt), 0);
 517                        if (!bp) {
 518                                error = ENOMEM;
 519                                goto error2;
 520                        }
 521                        bp->b_ops = &xfs_symlink_buf_ops;
 522
 523                        byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
 524                        byte_cnt = min(byte_cnt, pathlen);
 525
 526                        buf = bp->b_addr;
 527                        buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
 528                                                   byte_cnt, bp);
 529
 530                        memcpy(buf, cur_chunk, byte_cnt);
 531
 532                        cur_chunk += byte_cnt;
 533                        pathlen -= byte_cnt;
 534                        offset += byte_cnt;
 535
 536                        xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
 537                                                        (char *)bp->b_addr);
 538                }
 539                ASSERT(pathlen == 0);
 540        }
 541
 542        /*
 543         * Create the directory entry for the symlink.
 544         */
 545        error = xfs_dir_createname(tp, dp, link_name, ip->i_ino,
 546                                        &first_block, &free_list, resblks);
 547        if (error)
 548                goto error2;
 549        xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
 550        xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
 551
 552        /*
 553         * If this is a synchronous mount, make sure that the
 554         * symlink transaction goes to disk before returning to
 555         * the user.
 556         */
 557        if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
 558                xfs_trans_set_sync(tp);
 559        }
 560
 561        error = xfs_bmap_finish(&tp, &free_list, &committed);
 562        if (error) {
 563                goto error2;
 564        }
 565        error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 566        xfs_qm_dqrele(udqp);
 567        xfs_qm_dqrele(gdqp);
 568        xfs_qm_dqrele(pdqp);
 569
 570        *ipp = ip;
 571        return 0;
 572
 573 error2:
 574        IRELE(ip);
 575 error1:
 576        xfs_bmap_cancel(&free_list);
 577        cancel_flags |= XFS_TRANS_ABORT;
 578 error_return:
 579        xfs_trans_cancel(tp, cancel_flags);
 580        xfs_qm_dqrele(udqp);
 581        xfs_qm_dqrele(gdqp);
 582        xfs_qm_dqrele(pdqp);
 583
 584        if (unlock_dp_on_error)
 585                xfs_iunlock(dp, XFS_ILOCK_EXCL);
 586 std_return:
 587        return error;
 588}
 589
 590/*
 591 * Free a symlink that has blocks associated with it.
 592 */
 593STATIC int
 594xfs_inactive_symlink_rmt(
 595        xfs_inode_t     *ip,
 596        xfs_trans_t     **tpp)
 597{
 598        xfs_buf_t       *bp;
 599        int             committed;
 600        int             done;
 601        int             error;
 602        xfs_fsblock_t   first_block;
 603        xfs_bmap_free_t free_list;
 604        int             i;
 605        xfs_mount_t     *mp;
 606        xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
 607        int             nmaps;
 608        xfs_trans_t     *ntp;
 609        int             size;
 610        xfs_trans_t     *tp;
 611
 612        tp = *tpp;
 613        mp = ip->i_mount;
 614        ASSERT(ip->i_df.if_flags & XFS_IFEXTENTS);
 615        /*
 616         * We're freeing a symlink that has some
 617         * blocks allocated to it.  Free the
 618         * blocks here.  We know that we've got
 619         * either 1 or 2 extents and that we can
 620         * free them all in one bunmapi call.
 621         */
 622        ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
 623
 624        /*
 625         * Lock the inode, fix the size, and join it to the transaction.
 626         * Hold it so in the normal path, we still have it locked for
 627         * the second transaction.  In the error paths we need it
 628         * held so the cancel won't rele it, see below.
 629         */
 630        size = (int)ip->i_d.di_size;
 631        ip->i_d.di_size = 0;
 632        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 633        /*
 634         * Find the block(s) so we can inval and unmap them.
 635         */
 636        done = 0;
 637        xfs_bmap_init(&free_list, &first_block);
 638        nmaps = ARRAY_SIZE(mval);
 639        error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
 640                                mval, &nmaps, 0);
 641        if (error)
 642                goto error0;
 643        /*
 644         * Invalidate the block(s). No validation is done.
 645         */
 646        for (i = 0; i < nmaps; i++) {
 647                bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
 648                        XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
 649                        XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
 650                if (!bp) {
 651                        error = ENOMEM;
 652                        goto error1;
 653                }
 654                xfs_trans_binval(tp, bp);
 655        }
 656        /*
 657         * Unmap the dead block(s) to the free_list.
 658         */
 659        if ((error = xfs_bunmapi(tp, ip, 0, size, XFS_BMAPI_METADATA, nmaps,
 660                        &first_block, &free_list, &done)))
 661                goto error1;
 662        ASSERT(done);
 663        /*
 664         * Commit the first transaction.  This logs the EFI and the inode.
 665         */
 666        if ((error = xfs_bmap_finish(&tp, &free_list, &committed)))
 667                goto error1;
 668        /*
 669         * The transaction must have been committed, since there were
 670         * actually extents freed by xfs_bunmapi.  See xfs_bmap_finish.
 671         * The new tp has the extent freeing and EFDs.
 672         */
 673        ASSERT(committed);
 674        /*
 675         * The first xact was committed, so add the inode to the new one.
 676         * Mark it dirty so it will be logged and moved forward in the log as
 677         * part of every commit.
 678         */
 679        xfs_trans_ijoin(tp, ip, 0);
 680        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 681        /*
 682         * Get a new, empty transaction to return to our caller.
 683         */
 684        ntp = xfs_trans_dup(tp);
 685        /*
 686         * Commit the transaction containing extent freeing and EFDs.
 687         * If we get an error on the commit here or on the reserve below,
 688         * we need to unlock the inode since the new transaction doesn't
 689         * have the inode attached.
 690         */
 691        error = xfs_trans_commit(tp, 0);
 692        tp = ntp;
 693        if (error) {
 694                ASSERT(XFS_FORCED_SHUTDOWN(mp));
 695                goto error0;
 696        }
 697        /*
 698         * transaction commit worked ok so we can drop the extra ticket
 699         * reference that we gained in xfs_trans_dup()
 700         */
 701        xfs_log_ticket_put(tp->t_ticket);
 702
 703        /*
 704         * Remove the memory for extent descriptions (just bookkeeping).
 705         */
 706        if (ip->i_df.if_bytes)
 707                xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
 708        ASSERT(ip->i_df.if_bytes == 0);
 709        /*
 710         * Put an itruncate log reservation in the new transaction
 711         * for our caller.
 712         */
 713        if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
 714                        XFS_TRANS_PERM_LOG_RES, XFS_ITRUNCATE_LOG_COUNT))) {
 715                ASSERT(XFS_FORCED_SHUTDOWN(mp));
 716                goto error0;
 717        }
 718
 719        xfs_trans_ijoin(tp, ip, 0);
 720        *tpp = tp;
 721        return 0;
 722
 723 error1:
 724        xfs_bmap_cancel(&free_list);
 725 error0:
 726        return error;
 727}
 728
 729/*
 730 * xfs_inactive_symlink - free a symlink
 731 */
 732int
 733xfs_inactive_symlink(
 734        struct xfs_inode        *ip,
 735        struct xfs_trans        **tp)
 736{
 737        struct xfs_mount        *mp = ip->i_mount;
 738        int                     pathlen;
 739
 740        trace_xfs_inactive_symlink(ip);
 741
 742        ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
 743
 744        if (XFS_FORCED_SHUTDOWN(mp))
 745                return XFS_ERROR(EIO);
 746
 747        /*
 748         * Zero length symlinks _can_ exist.
 749         */
 750        pathlen = (int)ip->i_d.di_size;
 751        if (!pathlen)
 752                return 0;
 753
 754        if (pathlen < 0 || pathlen > MAXPATHLEN) {
 755                xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
 756                         __func__, (unsigned long long)ip->i_ino, pathlen);
 757                ASSERT(0);
 758                return XFS_ERROR(EFSCORRUPTED);
 759        }
 760
 761        if (ip->i_df.if_flags & XFS_IFINLINE) {
 762                if (ip->i_df.if_bytes > 0)
 763                        xfs_idata_realloc(ip, -(ip->i_df.if_bytes),
 764                                          XFS_DATA_FORK);
 765                ASSERT(ip->i_df.if_bytes == 0);
 766                return 0;
 767        }
 768
 769        /* remove the remote symlink */
 770        return xfs_inactive_symlink_rmt(ip, tp);
 771}
 772
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