fs/xfs/xfs_symlink.h

   1 /*
   2  * Copyright (c) 2012 Red Hat, Inc. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write the Free Software Foundation,
  15  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  16  */
  17 #ifndef __XFS_SYMLINK_H
  18 #define __XFS_SYMLINK_H 1
  19
  20 struct xfs_mount;
  21 struct xfs_trans;
  22 struct xfs_inode;
  23 struct xfs_buf;
  24 struct xfs_ifork;
  25 struct xfs_name;
  26
  27 #define XFS_SYMLINK_MAGIC       0x58534c4d      /* XSLM */
  28
  29 struct xfs_dsymlink_hdr {
  30         __be32  sl_magic;
  31         __be32  sl_offset;
  32         __be32  sl_bytes;
  33         __be32  sl_crc;
  34         uuid_t  sl_uuid;
  35         __be64  sl_owner;
  36         __be64  sl_blkno;
  37         __be64  sl_lsn;
  38 };
  39
  40 /*
  41  * The maximum pathlen is 1024 bytes. Since the minimum file system
  42  * blocksize is 512 bytes, we can get a max of 3 extents back from
  43  * bmapi when crc headers are taken into account.
  44  */
  45 #define XFS_SYMLINK_MAPS 3
  46
  47 #define XFS_SYMLINK_BUF_SPACE(mp, bufsize)      \
  48         ((bufsize) - (xfs_sb_version_hascrc(&(mp)->m_sb) ? \
  49                         sizeof(struct xfs_dsymlink_hdr) : 0))
  50
  51 int xfs_symlink_blocks(struct xfs_mount *mp, int pathlen);
  52
  53 void xfs_symlink_local_to_remote(struct xfs_trans *tp, struct xfs_buf *bp,
  54                                  struct xfs_inode *ip, struct xfs_ifork *ifp);
  55
  56 extern const struct xfs_buf_ops xfs_symlink_buf_ops;
  57
  58 #ifdef __KERNEL__
  59
  60 int xfs_symlink(struct xfs_inode *dp, struct xfs_name *link_name,
  61                 const char *target_path, umode_t mode, struct xfs_inode **ipp);
  62 int xfs_readlink(struct xfs_inode *ip, char *link);
  63 int xfs_inactive_symlink(struct xfs_inode *ip, struct xfs_trans **tpp);
  64
  65 #endif /* __KERNEL__ */
  66 #endif /* __XFS_SYMLINK_H */