fs/xfs/scrub/symlink.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2017 Oracle.  All Rights Reserved.
   4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   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_defer.h"
  13 #include "xfs_btree.h"
  14 #include "xfs_bit.h"
  15 #include "xfs_log_format.h"
  16 #include "xfs_trans.h"
  17 #include "xfs_sb.h"
  18 #include "xfs_inode.h"
  19 #include "xfs_inode_fork.h"
  20 #include "xfs_symlink.h"
  21 #include "scrub/xfs_scrub.h"
  22 #include "scrub/scrub.h"
  23 #include "scrub/common.h"
  24 #include "scrub/trace.h"
  25
  26 /* Set us up to scrub a symbolic link. */
  27 int
  28 xchk_setup_symlink(
  29         struct xfs_scrub        *sc,
  30         struct xfs_inode        *ip)
  31 {
  32         /* Allocate the buffer without the inode lock held. */
  33         sc->buf = kmem_zalloc_large(XFS_SYMLINK_MAXLEN + 1, KM_SLEEP);
  34         if (!sc->buf)
  35                 return -ENOMEM;
  36
  37         return xchk_setup_inode_contents(sc, ip, 0);
  38 }
  39
  40 /* Symbolic links. */
  41
  42 int
  43 xchk_symlink(
  44         struct xfs_scrub        *sc)
  45 {
  46         struct xfs_inode        *ip = sc->ip;
  47         struct xfs_ifork        *ifp;
  48         loff_t                  len;
  49         int                     error = 0;
  50
  51         if (!S_ISLNK(VFS_I(ip)->i_mode))
  52                 return -ENOENT;
  53         ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
  54         len = ip->i_d.di_size;
  55
  56         /* Plausible size? */
  57         if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
  58                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  59                 goto out;
  60         }
  61
  62         /* Inline symlink? */
  63         if (ifp->if_flags & XFS_IFINLINE) {
  64                 if (len > XFS_IFORK_DSIZE(ip) ||
  65                     len > strnlen(ifp->if_u1.if_data, XFS_IFORK_DSIZE(ip)))
  66                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  67                 goto out;
  68         }
  69
  70         /* Remote symlink; must read the contents. */
  71         error = xfs_readlink_bmap_ilocked(sc->ip, sc->buf);
  72         if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
  73                 goto out;
  74         if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
  75                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  76 out:
  77         return error;
  78 }