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 */ 31 struct 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 48 extern const struct xfs_buf_ops xfs_attr3_rmt_buf_ops; 49 50 int xfs_attr3_rmt_blocks(struct xfs_mount *mp, int attrlen); 51 52 int xfs_attr_rmtval_get(struct xfs_da_args *args); 53 int xfs_attr_rmtval_set(struct xfs_da_args *args); 54 int xfs_attr_rmtval_remove(struct xfs_da_args *args); 55 56 #endif /* __XFS_ATTR_REMOTE_H__ */ 57