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{
23	/* Allocate the buffer without the inode lock held. */
24	sc->buf = kvzalloc(XFS_SYMLINK_MAXLEN + 1, GFP_KERNEL);
25	if (!sc->buf)
26		return -ENOMEM;
27
28	return xchk_setup_inode_contents(sc, 0);
29}
30
31/* Symbolic links. */
32
33int
34xchk_symlink(
35	struct xfs_scrub	*sc)
36{
37	struct xfs_inode	*ip = sc->ip;
38	struct xfs_ifork	*ifp;
39	loff_t			len;
40	int			error = 0;
41
42	if (!S_ISLNK(VFS_I(ip)->i_mode))
43		return -ENOENT;
44	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
45	len = ip->i_disk_size;
46
47	/* Plausible size? */
48	if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
49		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
50		goto out;
51	}
52
53	/* Inline symlink? */
54	if (ifp->if_format == XFS_DINODE_FMT_LOCAL) {
55		if (len > XFS_IFORK_DSIZE(ip) ||
56		    len > strnlen(ifp->if_u1.if_data, XFS_IFORK_DSIZE(ip)))
57			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
58		goto out;
59	}
60
61	/* Remote symlink; must read the contents. */
62	error = xfs_readlink_bmap_ilocked(sc->ip, sc->buf);
63	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
64		goto out;
65	if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
66		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
67out:
68	return error;
69}
70