xref: /linux/fs/xfs/scrub/symlink.c (revision 71dfa617ea9f18e4585fe78364217cd32b1fc382)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2017-2023 Oracle.  All Rights Reserved.
4  * Author: Darrick J. Wong <djwong@kernel.org>
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 "xfs_health.h"
16 #include "xfs_symlink_remote.h"
17 #include "scrub/scrub.h"
18 #include "scrub/common.h"
19 #include "scrub/health.h"
20 
21 /* Set us up to scrub a symbolic link. */
22 int
23 xchk_setup_symlink(
24 	struct xfs_scrub	*sc)
25 {
26 	/* Allocate the buffer without the inode lock held. */
27 	sc->buf = kvzalloc(XFS_SYMLINK_MAXLEN + 1, XCHK_GFP_FLAGS);
28 	if (!sc->buf)
29 		return -ENOMEM;
30 
31 	return xchk_setup_inode_contents(sc, 0);
32 }
33 
34 /* Symbolic links. */
35 
36 int
37 xchk_symlink(
38 	struct xfs_scrub	*sc)
39 {
40 	struct xfs_inode	*ip = sc->ip;
41 	struct xfs_ifork	*ifp;
42 	loff_t			len;
43 	int			error = 0;
44 
45 	if (!S_ISLNK(VFS_I(ip)->i_mode))
46 		return -ENOENT;
47 
48 	if (xchk_file_looks_zapped(sc, XFS_SICK_INO_SYMLINK_ZAPPED)) {
49 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
50 		return 0;
51 	}
52 
53 	ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
54 	len = ip->i_disk_size;
55 
56 	/* Plausible size? */
57 	if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
58 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
59 		return 0;
60 	}
61 
62 	/* Inline symlink? */
63 	if (ifp->if_format == XFS_DINODE_FMT_LOCAL) {
64 		if (len > xfs_inode_data_fork_size(ip) ||
65 		    len > strnlen(ifp->if_data, xfs_inode_data_fork_size(ip)))
66 			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
67 		return 0;
68 	}
69 
70 	/* Remote symlink; must read the contents. */
71 	error = xfs_symlink_remote_read(sc->ip, sc->buf);
72 	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
73 		return error;
74 	if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
75 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
76 
77 	/* If a remote symlink is clean, it is clearly not zapped. */
78 	xchk_mark_healthy_if_clean(sc, XFS_SICK_INO_SYMLINK_ZAPPED);
79 	return 0;
80 }
81