1/* SPDX-License-Identifier: GPL-2.0-or-later */
 2/*
 3 * Copyright (C) 2019 Oracle.  All Rights Reserved.
 4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
 5 */
 6#ifndef __XFS_SCRUB_ATTR_H__
 7#define __XFS_SCRUB_ATTR_H__
 8
 9/*
10 * Temporary storage for online scrub and repair of extended attributes.
11 */
12struct xchk_xattr_buf {
13	/* Size of @buf, in bytes. */
14	size_t			sz;
15
16	/*
17	 * Memory buffer -- either used for extracting attr values while
18	 * walking the attributes; or for computing attr block bitmaps when
19	 * checking the attribute tree.
20	 *
21	 * Each bitmap contains enough bits to track every byte in an attr
22	 * block (rounded up to the size of an unsigned long).  The attr block
23	 * used space bitmap starts at the beginning of the buffer; the free
24	 * space bitmap follows immediately after; and we have a third buffer
25	 * for storing intermediate bitmap results.
26	 */
27	uint8_t			buf[0];
28};
29
30/* A place to store attribute values. */
31static inline uint8_t *
32xchk_xattr_valuebuf(
33	struct xfs_scrub	*sc)
34{
35	struct xchk_xattr_buf	*ab = sc->buf;
36
37	return ab->buf;
38}
39
40/* A bitmap of space usage computed by walking an attr leaf block. */
41static inline unsigned long *
42xchk_xattr_usedmap(
43	struct xfs_scrub	*sc)
44{
45	struct xchk_xattr_buf	*ab = sc->buf;
46
47	return (unsigned long *)ab->buf;
48}
49
50/* A bitmap of free space computed by walking attr leaf block free info. */
51static inline unsigned long *
52xchk_xattr_freemap(
53	struct xfs_scrub	*sc)
54{
55	return xchk_xattr_usedmap(sc) +
56			BITS_TO_LONGS(sc->mp->m_attr_geo->blksize);
57}
58
59/* A bitmap used to hold temporary results. */
60static inline unsigned long *
61xchk_xattr_dstmap(
62	struct xfs_scrub	*sc)
63{
64	return xchk_xattr_freemap(sc) +
65			BITS_TO_LONGS(sc->mp->m_attr_geo->blksize);
66}
67
68int xchk_setup_xattr_buf(struct xfs_scrub *sc, size_t value_size,
69		xfs_km_flags_t flags);
70
71#endif	/* __XFS_SCRUB_ATTR_H__ */