xref: /OK3568_Linux_fs/kernel/fs/xfs/scrub/symlink.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0+
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Copyright (C) 2017 Oracle.  All Rights Reserved.
4*4882a593Smuzhiyun  * Author: Darrick J. Wong <darrick.wong@oracle.com>
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun #include "xfs.h"
7*4882a593Smuzhiyun #include "xfs_fs.h"
8*4882a593Smuzhiyun #include "xfs_shared.h"
9*4882a593Smuzhiyun #include "xfs_format.h"
10*4882a593Smuzhiyun #include "xfs_trans_resv.h"
11*4882a593Smuzhiyun #include "xfs_mount.h"
12*4882a593Smuzhiyun #include "xfs_log_format.h"
13*4882a593Smuzhiyun #include "xfs_inode.h"
14*4882a593Smuzhiyun #include "xfs_symlink.h"
15*4882a593Smuzhiyun #include "scrub/scrub.h"
16*4882a593Smuzhiyun #include "scrub/common.h"
17*4882a593Smuzhiyun 
18*4882a593Smuzhiyun /* Set us up to scrub a symbolic link. */
19*4882a593Smuzhiyun int
xchk_setup_symlink(struct xfs_scrub * sc,struct xfs_inode * ip)20*4882a593Smuzhiyun xchk_setup_symlink(
21*4882a593Smuzhiyun 	struct xfs_scrub	*sc,
22*4882a593Smuzhiyun 	struct xfs_inode	*ip)
23*4882a593Smuzhiyun {
24*4882a593Smuzhiyun 	/* Allocate the buffer without the inode lock held. */
25*4882a593Smuzhiyun 	sc->buf = kvzalloc(XFS_SYMLINK_MAXLEN + 1, GFP_KERNEL);
26*4882a593Smuzhiyun 	if (!sc->buf)
27*4882a593Smuzhiyun 		return -ENOMEM;
28*4882a593Smuzhiyun 
29*4882a593Smuzhiyun 	return xchk_setup_inode_contents(sc, ip, 0);
30*4882a593Smuzhiyun }
31*4882a593Smuzhiyun 
32*4882a593Smuzhiyun /* Symbolic links. */
33*4882a593Smuzhiyun 
34*4882a593Smuzhiyun int
xchk_symlink(struct xfs_scrub * sc)35*4882a593Smuzhiyun xchk_symlink(
36*4882a593Smuzhiyun 	struct xfs_scrub	*sc)
37*4882a593Smuzhiyun {
38*4882a593Smuzhiyun 	struct xfs_inode	*ip = sc->ip;
39*4882a593Smuzhiyun 	struct xfs_ifork	*ifp;
40*4882a593Smuzhiyun 	loff_t			len;
41*4882a593Smuzhiyun 	int			error = 0;
42*4882a593Smuzhiyun 
43*4882a593Smuzhiyun 	if (!S_ISLNK(VFS_I(ip)->i_mode))
44*4882a593Smuzhiyun 		return -ENOENT;
45*4882a593Smuzhiyun 	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
46*4882a593Smuzhiyun 	len = ip->i_d.di_size;
47*4882a593Smuzhiyun 
48*4882a593Smuzhiyun 	/* Plausible size? */
49*4882a593Smuzhiyun 	if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
50*4882a593Smuzhiyun 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
51*4882a593Smuzhiyun 		goto out;
52*4882a593Smuzhiyun 	}
53*4882a593Smuzhiyun 
54*4882a593Smuzhiyun 	/* Inline symlink? */
55*4882a593Smuzhiyun 	if (ifp->if_flags & XFS_IFINLINE) {
56*4882a593Smuzhiyun 		if (len > XFS_IFORK_DSIZE(ip) ||
57*4882a593Smuzhiyun 		    len > strnlen(ifp->if_u1.if_data, XFS_IFORK_DSIZE(ip)))
58*4882a593Smuzhiyun 			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
59*4882a593Smuzhiyun 		goto out;
60*4882a593Smuzhiyun 	}
61*4882a593Smuzhiyun 
62*4882a593Smuzhiyun 	/* Remote symlink; must read the contents. */
63*4882a593Smuzhiyun 	error = xfs_readlink_bmap_ilocked(sc->ip, sc->buf);
64*4882a593Smuzhiyun 	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
65*4882a593Smuzhiyun 		goto out;
66*4882a593Smuzhiyun 	if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
67*4882a593Smuzhiyun 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
68*4882a593Smuzhiyun out:
69*4882a593Smuzhiyun 	return error;
70*4882a593Smuzhiyun }
71