tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * Copyright (c) 2013 Red Hat, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#ifndef __XFS_ATTR_REMOTE_H__
19#define __XFS_ATTR_REMOTE_H__
20
21#define XFS_ATTR3_RMT_MAGIC 0x5841524d /* XARM */
22
23/*
24 * There is one of these headers per filesystem block in a remote attribute.
25 * This is done to ensure there is a 1:1 mapping between the attribute value
26 * length and the number of blocks needed to store the attribute. This makes the
27 * verification of a buffer a little more complex, but greatly simplifies the
28 * allocation, reading and writing of these attributes as we don't have to guess
29 * the number of blocks needed to store the attribute data.
30 */
31struct xfs_attr3_rmt_hdr {
32 __be32 rm_magic;
33 __be32 rm_offset;
34 __be32 rm_bytes;
35 __be32 rm_crc;
36 uuid_t rm_uuid;
37 __be64 rm_owner;
38 __be64 rm_blkno;
39 __be64 rm_lsn;
40};
41
42#define XFS_ATTR3_RMT_CRC_OFF offsetof(struct xfs_attr3_rmt_hdr, rm_crc)
43
44#define XFS_ATTR3_RMT_BUF_SPACE(mp, bufsize) \
45 ((bufsize) - (xfs_sb_version_hascrc(&(mp)->m_sb) ? \
46 sizeof(struct xfs_attr3_rmt_hdr) : 0))
47
48extern const struct xfs_buf_ops xfs_attr3_rmt_buf_ops;
49
50int xfs_attr3_rmt_blocks(struct xfs_mount *mp, int attrlen);
51
52int xfs_attr_rmtval_get(struct xfs_da_args *args);
53int xfs_attr_rmtval_set(struct xfs_da_args *args);
54int xfs_attr_rmtval_remove(struct xfs_da_args *args);
55
56#endif /* __XFS_ATTR_REMOTE_H__ */