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Diffstat (limited to 'fs/xfs/xfs_attr_remote.h')
| -rw-r--r-- | fs/xfs/xfs_attr_remote.h | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/fs/xfs/xfs_attr_remote.h b/fs/xfs/xfs_attr_remote.h new file mode 100644 index 00000000000..92a8fd7977c --- /dev/null +++ b/fs/xfs/xfs_attr_remote.h @@ -0,0 +1,56 @@ +/* + * Copyright (c) 2013 Red Hat, Inc. + * All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ +#ifndef __XFS_ATTR_REMOTE_H__ +#define __XFS_ATTR_REMOTE_H__ + +#define XFS_ATTR3_RMT_MAGIC 0x5841524d /* XARM */ + +/* + * There is one of these headers per filesystem block in a remote attribute. + * This is done to ensure there is a 1:1 mapping between the attribute value + * length and the number of blocks needed to store the attribute. This makes the + * verification of a buffer a little more complex, but greatly simplifies the + * allocation, reading and writing of these attributes as we don't have to guess + * the number of blocks needed to store the attribute data. + */ +struct xfs_attr3_rmt_hdr { + __be32 rm_magic; + __be32 rm_offset; + __be32 rm_bytes; + __be32 rm_crc; + uuid_t rm_uuid; + __be64 rm_owner; + __be64 rm_blkno; + __be64 rm_lsn; +}; + +#define XFS_ATTR3_RMT_CRC_OFF offsetof(struct xfs_attr3_rmt_hdr, rm_crc) + +#define XFS_ATTR3_RMT_BUF_SPACE(mp, bufsize) \ + ((bufsize) - (xfs_sb_version_hascrc(&(mp)->m_sb) ? \ + sizeof(struct xfs_attr3_rmt_hdr) : 0)) + +extern const struct xfs_buf_ops xfs_attr3_rmt_buf_ops; + +int xfs_attr3_rmt_blocks(struct xfs_mount *mp, int attrlen); + +int xfs_attr_rmtval_get(struct xfs_da_args *args); +int xfs_attr_rmtval_set(struct xfs_da_args *args); +int xfs_attr_rmtval_remove(struct xfs_da_args *args); + +#endif /* __XFS_ATTR_REMOTE_H__ */ |