xfs/scrub/symlink.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * Copyright (C) 2017 Oracle.  All Rights Reserved.
0004  * Author: Darrick J. Wong <darrick.wong@oracle.com>
0005  */
0006 #include "xfs.h"
0007 #include "xfs_fs.h"
0008 #include "xfs_shared.h"
0009 #include "xfs_format.h"
0010 #include "xfs_trans_resv.h"
0011 #include "xfs_mount.h"
0012 #include "xfs_log_format.h"
0013 #include "xfs_inode.h"
0014 #include "xfs_symlink.h"
0015 #include "scrub/scrub.h"
0016 #include "scrub/common.h"
0017
0018 /* Set us up to scrub a symbolic link. */
0019 int
0020 xchk_setup_symlink(
0021     struct xfs_scrub    *sc)
0022 {
0023     /* Allocate the buffer without the inode lock held. */
0024     sc->buf = kvzalloc(XFS_SYMLINK_MAXLEN + 1, GFP_KERNEL);
0025     if (!sc->buf)
0026         return -ENOMEM;
0027
0028     return xchk_setup_inode_contents(sc, 0);
0029 }
0030
0031 /* Symbolic links. */
0032
0033 int
0034 xchk_symlink(
0035     struct xfs_scrub    *sc)
0036 {
0037     struct xfs_inode    *ip = sc->ip;
0038     struct xfs_ifork    *ifp;
0039     loff_t          len;
0040     int         error = 0;
0041
0042     if (!S_ISLNK(VFS_I(ip)->i_mode))
0043         return -ENOENT;
0044     ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
0045     len = ip->i_disk_size;
0046
0047     /* Plausible size? */
0048     if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
0049         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
0050         goto out;
0051     }
0052
0053     /* Inline symlink? */
0054     if (ifp->if_format == XFS_DINODE_FMT_LOCAL) {
0055         if (len > xfs_inode_data_fork_size(ip) ||
0056             len > strnlen(ifp->if_u1.if_data, xfs_inode_data_fork_size(ip)))
0057             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
0058         goto out;
0059     }
0060
0061     /* Remote symlink; must read the contents. */
0062     error = xfs_readlink_bmap_ilocked(sc->ip, sc->buf);
0063     if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
0064         goto out;
0065     if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
0066         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
0067 out:
0068     return error;
0069 }