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_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
xchk_setup_symlink(struct xfs_scrub * sc)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
xchk_symlink(struct xfs_scrub * sc)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 }
70