fs/xfs/scrub/symlink.c

   1 /*
   2  * Copyright (C) 2017 Oracle.  All Rights Reserved.
   3  *
   4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   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
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it would be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write the Free Software Foundation,
  18  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
  19  */
  20 #include "xfs.h"
  21 #include "xfs_fs.h"
  22 #include "xfs_shared.h"
  23 #include "xfs_format.h"
  24 #include "xfs_trans_resv.h"
  25 #include "xfs_mount.h"
  26 #include "xfs_defer.h"
  27 #include "xfs_btree.h"
  28 #include "xfs_bit.h"
  29 #include "xfs_log_format.h"
  30 #include "xfs_trans.h"
  31 #include "xfs_sb.h"
  32 #include "xfs_inode.h"
  33 #include "xfs_inode_fork.h"
  34 #include "xfs_symlink.h"
  35 #include "scrub/xfs_scrub.h"
  36 #include "scrub/scrub.h"
  37 #include "scrub/common.h"
  38 #include "scrub/trace.h"
  39
  40 /* Set us up to scrub a symbolic link. */
  41 int
  42 xfs_scrub_setup_symlink(
  43         struct xfs_scrub_context        *sc,
  44         struct xfs_inode                *ip)
  45 {
  46         /* Allocate the buffer without the inode lock held. */
  47         sc->buf = kmem_zalloc_large(XFS_SYMLINK_MAXLEN + 1, KM_SLEEP);
  48         if (!sc->buf)
  49                 return -ENOMEM;
  50
  51         return xfs_scrub_setup_inode_contents(sc, ip, 0);
  52 }
  53
  54 /* Symbolic links. */
  55
  56 int
  57 xfs_scrub_symlink(
  58         struct xfs_scrub_context        *sc)
  59 {
  60         struct xfs_inode                *ip = sc->ip;
  61         struct xfs_ifork                *ifp;
  62         loff_t                          len;
  63         int                             error = 0;
  64
  65         if (!S_ISLNK(VFS_I(ip)->i_mode))
  66                 return -ENOENT;
  67         ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
  68         len = ip->i_d.di_size;
  69
  70         /* Plausible size? */
  71         if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
  72                 xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  73                 goto out;
  74         }
  75
  76         /* Inline symlink? */
  77         if (ifp->if_flags & XFS_IFINLINE) {
  78                 if (len > XFS_IFORK_DSIZE(ip) ||
  79                     len > strnlen(ifp->if_u1.if_data, XFS_IFORK_DSIZE(ip)))
  80                         xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  81                 goto out;
  82         }
  83
  84         /* Remote symlink; must read the contents. */
  85         error = xfs_readlink_bmap_ilocked(sc->ip, sc->buf);
  86         if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
  87                 goto out;
  88         if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
  89                 xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  90 out:
  91         return error;
  92 }