xref: /linux/fs/xfs/scrub/symlink.c (revision 249ebf3f65f8530beb2cbfb91bff1d83ba88d23c)
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_trans.h"
14 #include "xfs_inode.h"
15 #include "xfs_symlink.h"
16 #include "xfs_health.h"
17 #include "xfs_symlink_remote.h"
18 #include "scrub/scrub.h"
19 #include "scrub/common.h"
20 #include "scrub/health.h"
21 #include "scrub/repair.h"
22 
23 /* Set us up to scrub a symbolic link. */
24 int
25 xchk_setup_symlink(
26 	struct xfs_scrub	*sc)
27 {
28 	unsigned int		resblks = 0;
29 	int			error;
30 
31 	/* Allocate the buffer without the inode lock held. */
32 	sc->buf = kvzalloc(XFS_SYMLINK_MAXLEN + 1, XCHK_GFP_FLAGS);
33 	if (!sc->buf)
34 		return -ENOMEM;
35 
36 	if (xchk_could_repair(sc)) {
37 		error = xrep_setup_symlink(sc, &resblks);
38 		if (error)
39 			return error;
40 	}
41 
42 	return xchk_setup_inode_contents(sc, resblks);
43 }
44 
45 /* Symbolic links. */
46 
47 int
48 xchk_symlink(
49 	struct xfs_scrub	*sc)
50 {
51 	struct xfs_inode	*ip = sc->ip;
52 	struct xfs_ifork	*ifp;
53 	loff_t			len;
54 	int			error = 0;
55 
56 	if (!S_ISLNK(VFS_I(ip)->i_mode))
57 		return -ENOENT;
58 
59 	if (xchk_file_looks_zapped(sc, XFS_SICK_INO_SYMLINK_ZAPPED)) {
60 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
61 		return 0;
62 	}
63 
64 	ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
65 	len = ip->i_disk_size;
66 
67 	/* Plausible size? */
68 	if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
69 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
70 		return 0;
71 	}
72 
73 	/* Inline symlink? */
74 	if (ifp->if_format == XFS_DINODE_FMT_LOCAL) {
75 		if (len > xfs_inode_data_fork_size(ip) ||
76 		    len > strnlen(ifp->if_data, xfs_inode_data_fork_size(ip)))
77 			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
78 		return 0;
79 	}
80 
81 	/* Remote symlink; must read the contents. */
82 	error = xfs_symlink_remote_read(sc->ip, sc->buf);
83 	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
84 		return error;
85 	if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
86 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
87 
88 	/* If a remote symlink is clean, it is clearly not zapped. */
89 	xchk_mark_healthy_if_clean(sc, XFS_SICK_INO_SYMLINK_ZAPPED);
90 	return 0;
91 }
92