fs/xfs/scrub/symlink.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2017-2023 Oracle.  All Rights Reserved.
   4  * Author: Darrick J. Wong <[email protected]>
   5  */
   6 #include "xfs.h"
   7 #include "xfs_fs.h"
   8 #include "xfs_shared.h"
   9 #include "xfs_format.h"
  10 #include "xfs_trans_resv.h"
  11 #include "xfs_mount.h"
  12 #include "xfs_log_format.h"
  13 #include "xfs_inode.h"
  14 #include "xfs_symlink.h"
  15 #include "scrub/scrub.h"
  16 #include "scrub/common.h"
  17
  18 /* Set us up to scrub a symbolic link. */
  19 int
  20 xchk_setup_symlink(
  21         struct xfs_scrub        *sc)
  22 {
  23         /* Allocate the buffer without the inode lock held. */
  24         sc->buf = kvzalloc(XFS_SYMLINK_MAXLEN + 1, XCHK_GFP_FLAGS);
  25         if (!sc->buf)
  26                 return -ENOMEM;
  27
  28         return xchk_setup_inode_contents(sc, 0);
  29 }
  30
  31 /* Symbolic links. */
  32
  33 int
  34 xchk_symlink(
  35         struct xfs_scrub        *sc)
  36 {
  37         struct xfs_inode        *ip = sc->ip;
  38         struct xfs_ifork        *ifp;
  39         loff_t                  len;
  40         int                     error = 0;
  41
  42         if (!S_ISLNK(VFS_I(ip)->i_mode))
  43                 return -ENOENT;
  44         ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
  45         len = ip->i_disk_size;
  46
  47         /* Plausible size? */
  48         if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
  49                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  50                 goto out;
  51         }
  52
  53         /* Inline symlink? */
  54         if (ifp->if_format == XFS_DINODE_FMT_LOCAL) {
  55                 if (len > xfs_inode_data_fork_size(ip) ||
  56                     len > strnlen(ifp->if_u1.if_data, xfs_inode_data_fork_size(ip)))
  57                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  58                 goto out;
  59         }
  60
  61         /* Remote symlink; must read the contents. */
  62         error = xfs_readlink_bmap_ilocked(sc->ip, sc->buf);
  63         if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
  64                 goto out;
  65         if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
  66                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  67 out:
  68         return error;
  69 }