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. */
19int
20xchk_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
34int
35xchk_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);
68out:
69	return error;
70}