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 "xfs_health.h"
  16 #include "xfs_symlink_remote.h"
  17 #include "scrub/scrub.h"
  18 #include "scrub/common.h"
  19 #include "scrub/health.h"
  20
  21 /* Set us up to scrub a symbolic link. */
  22 int
  23 xchk_setup_symlink(
  24         struct xfs_scrub        *sc)
  25 {
  26         /* Allocate the buffer without the inode lock held. */
  27         sc->buf = kvzalloc(XFS_SYMLINK_MAXLEN + 1, XCHK_GFP_FLAGS);
  28         if (!sc->buf)
  29                 return -ENOMEM;
  30
  31         return xchk_setup_inode_contents(sc, 0);
  32 }
  33
  34 /* Symbolic links. */
  35
  36 int
  37 xchk_symlink(
  38         struct xfs_scrub        *sc)
  39 {
  40         struct xfs_inode        *ip = sc->ip;
  41         struct xfs_ifork        *ifp;
  42         loff_t                  len;
  43         int                     error = 0;
  44
  45         if (!S_ISLNK(VFS_I(ip)->i_mode))
  46                 return -ENOENT;
  47
  48         if (xchk_file_looks_zapped(sc, XFS_SICK_INO_SYMLINK_ZAPPED)) {
  49                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  50                 return 0;
  51         }
  52
  53         ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
  54         len = ip->i_disk_size;
  55
  56         /* Plausible size? */
  57         if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
  58                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  59                 return 0;
  60         }
  61
  62         /* Inline symlink? */
  63         if (ifp->if_format == XFS_DINODE_FMT_LOCAL) {
  64                 if (len > xfs_inode_data_fork_size(ip) ||
  65                     len > strnlen(ifp->if_data, xfs_inode_data_fork_size(ip)))
  66                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  67                 return 0;
  68         }
  69
  70         /* Remote symlink; must read the contents. */
  71         error = xfs_symlink_remote_read(sc->ip, sc->buf);
  72         if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
  73                 return error;
  74         if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
  75                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  76
  77         /* If a remote symlink is clean, it is clearly not zapped. */
  78         xchk_mark_healthy_if_clean(sc, XFS_SICK_INO_SYMLINK_ZAPPED);
  79         return 0;
  80 }