fs/xfs/xfs_rw.h

   1 /*
   2  * Copyright (c) 2000-2003,2005 Silicon Graphics, 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_RW_H__
  19 #define __XFS_RW_H__
  20
  21 struct xfs_buf;
  22 struct xfs_inode;
  23 struct xfs_mount;
  24
  25 /*
  26  * Maximum count of bmaps used by read and write paths.
  27  */
  28 #define XFS_MAX_RW_NBMAPS       4
  29
  30 /*
  31  * Counts of readahead buffers to use based on physical memory size.
  32  * None of these should be more than XFS_MAX_RW_NBMAPS.
  33  */
  34 #define XFS_RW_NREADAHEAD_16MB  2
  35 #define XFS_RW_NREADAHEAD_32MB  3
  36 #define XFS_RW_NREADAHEAD_K32   4
  37 #define XFS_RW_NREADAHEAD_K64   4
  38
  39 /*
  40  * Maximum size of a buffer that we\'ll map.  Making this
  41  * too big will degrade performance due to the number of
  42  * pages which need to be gathered.  Making it too small
  43  * will prevent us from doing large I/O\'s to hardware that
  44  * needs it.
  45  *
  46  * This is currently set to 512 KB.
  47  */
  48 #define XFS_MAX_BMAP_LEN_BB     1024
  49 #define XFS_MAX_BMAP_LEN_BYTES  524288
  50
  51 /*
  52  * Convert the given file system block to a disk block.
  53  * We have to treat it differently based on whether the
  54  * file is a real time file or not, because the bmap code
  55  * does.
  56  */
  57 #define XFS_FSB_TO_DB(ip,fsb)   xfs_fsb_to_db(ip,fsb)
  58 static inline xfs_daddr_t
  59 xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb)
  60 {
  61         return (((ip)->i_d.di_flags & XFS_DIFLAG_REALTIME) ? \
  62                  (xfs_daddr_t)XFS_FSB_TO_BB((ip)->i_mount, (fsb)) : \
  63                  XFS_FSB_TO_DADDR((ip)->i_mount, (fsb)));
  64 }
  65 #define XFS_FSB_TO_DB_IO(io,fsb) xfs_fsb_to_db_io(io,fsb)
  66 static inline xfs_daddr_t
  67 xfs_fsb_to_db_io(struct xfs_iocore *io, xfs_fsblock_t fsb)
  68 {
  69         return (((io)->io_flags & XFS_IOCORE_RT) ? \
  70                  XFS_FSB_TO_BB((io)->io_mount, (fsb)) : \
  71                  XFS_FSB_TO_DADDR((io)->io_mount, (fsb)));
  72 }
  73
  74 /*
  75  * Prototypes for functions in xfs_rw.c.
  76  */
  77 extern int xfs_write_clear_setuid(struct xfs_inode *ip);
  78 extern int xfs_bwrite(struct xfs_mount *mp, struct xfs_buf *bp);
  79 extern int xfs_bioerror(struct xfs_buf *bp);
  80 extern int xfs_bioerror_relse(struct xfs_buf *bp);
  81 extern int xfs_read_buf(struct xfs_mount *mp, xfs_buftarg_t *btp,
  82                         xfs_daddr_t blkno, int len, uint flags,
  83                         struct xfs_buf **bpp);
  84 extern void xfs_ioerror_alert(char *func, struct xfs_mount *mp,
  85                                 xfs_buf_t *bp, xfs_daddr_t blkno);
  86
  87 /*
  88  * Prototypes for functions in xfs_vnodeops.c.
  89  */
  90 extern int xfs_rwlock(bhv_desc_t *bdp, vrwlock_t write_lock);
  91 extern void xfs_rwunlock(bhv_desc_t *bdp, vrwlock_t write_lock);
  92 extern int xfs_change_file_space(bhv_desc_t *bdp, int cmd, xfs_flock64_t *bf,
  93                                  xfs_off_t offset, cred_t *credp, int flags);
  94 extern int xfs_set_dmattrs(bhv_desc_t *bdp, u_int evmask, u_int16_t state,
  95                            cred_t *credp);
  96
  97 #endif /* __XFS_RW_H__ */