xref: /linux/fs/xfs/scrub/symlink.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
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 }
93