xref: /linux/fs/xfs/scrub/symlink.c (revision 8a79db5e83a5d52c74e6f3c40d6f312cf899213e)
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
20 xchk_setup_symlink(
21 	struct xfs_scrub	*sc,
22 	struct xfs_inode	*ip)
23 {
24 	/* Allocate the buffer without the inode lock held. */
25 	sc->buf = kmem_zalloc_large(XFS_SYMLINK_MAXLEN + 1, 0);
26 	if (!sc->buf)
27 		return -ENOMEM;
28 
29 	return xchk_setup_inode_contents(sc, ip, 0);
30 }
31 
32 /* Symbolic links. */
33 
34 int
35 xchk_symlink(
36 	struct xfs_scrub	*sc)
37 {
38 	struct xfs_inode	*ip = sc->ip;
39 	struct xfs_ifork	*ifp;
40 	loff_t			len;
41 	int			error = 0;
42 
43 	if (!S_ISLNK(VFS_I(ip)->i_mode))
44 		return -ENOENT;
45 	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
46 	len = ip->i_d.di_size;
47 
48 	/* Plausible size? */
49 	if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
50 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
51 		goto out;
52 	}
53 
54 	/* Inline symlink? */
55 	if (ifp->if_flags & XFS_IFINLINE) {
56 		if (len > XFS_IFORK_DSIZE(ip) ||
57 		    len > strnlen(ifp->if_u1.if_data, XFS_IFORK_DSIZE(ip)))
58 			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
59 		goto out;
60 	}
61 
62 	/* Remote symlink; must read the contents. */
63 	error = xfs_readlink_bmap_ilocked(sc->ip, sc->buf);
64 	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
65 		goto out;
66 	if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
67 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
68 out:
69 	return error;
70 }
71