fs/xfs/xfs_iomap.h

   1 /*
   2  * Copyright (c) 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_IOMAP_H__
  19 #define __XFS_IOMAP_H__
  20
  21 #define IOMAP_DADDR_NULL ((xfs_daddr_t) (-1LL))
  22
  23
  24 typedef enum {                          /* iomap_flags values */
  25         IOMAP_READ =            0,      /* mapping for a read */
  26         IOMAP_EOF =             0x01,   /* mapping contains EOF   */
  27         IOMAP_HOLE =            0x02,   /* mapping covers a hole  */
  28         IOMAP_DELAY =           0x04,   /* mapping covers delalloc region  */
  29         IOMAP_REALTIME =        0x10,   /* mapping on the realtime device  */
  30         IOMAP_UNWRITTEN =       0x20,   /* mapping covers allocated */
  31                                         /* but uninitialized file data  */
  32         IOMAP_NEW =             0x40    /* just allocate */
  33 } iomap_flags_t;
  34
  35 typedef enum {
  36         /* base extent manipulation calls */
  37         BMAPI_READ = (1 << 0),          /* read extents */
  38         BMAPI_WRITE = (1 << 1),         /* create extents */
  39         BMAPI_ALLOCATE = (1 << 2),      /* delayed allocate to real extents */
  40         BMAPI_UNWRITTEN  = (1 << 3),    /* unwritten extents to real extents */
  41         /* modifiers */
  42         BMAPI_IGNSTATE = (1 << 4),      /* ignore unwritten state on read */
  43         BMAPI_DIRECT = (1 << 5),        /* direct instead of buffered write */
  44         BMAPI_MMAP = (1 << 6),          /* allocate for mmap write */
  45         BMAPI_SYNC = (1 << 7),          /* sync write to flush delalloc space */
  46         BMAPI_TRYLOCK = (1 << 8),       /* non-blocking request */
  47         BMAPI_DEVICE = (1 << 9),        /* we only want to know the device */
  48 } bmapi_flags_t;
  49
  50
  51 /*
  52  * xfs_iomap_t:  File system I/O map
  53  *
  54  * The iomap_bn field is expressed in 512-byte blocks, and is where the
  55  * mapping starts on disk.
  56  *
  57  * The iomap_offset, iomap_bsize and iomap_delta fields are in bytes.
  58  * iomap_offset is the offset of the mapping in the file itself.
  59  * iomap_bsize is the size of the mapping,  iomap_delta is the
  60  * desired data's offset into the mapping, given the offset supplied
  61  * to the file I/O map routine.
  62  *
  63  * When a request is made to read beyond the logical end of the object,
  64  * iomap_size may be set to 0, but iomap_offset and iomap_length should be set
  65  * to the actual amount of underlying storage that has been allocated, if any.
  66  */
  67
  68 typedef struct xfs_iomap {
  69         xfs_daddr_t             iomap_bn;       /* first 512b blk of mapping */
  70         xfs_buftarg_t           *iomap_target;
  71         xfs_off_t               iomap_offset;   /* offset of mapping, bytes */
  72         xfs_off_t               iomap_bsize;    /* size of mapping, bytes */
  73         xfs_off_t               iomap_delta;    /* offset into mapping, bytes */
  74         iomap_flags_t           iomap_flags;
  75 } xfs_iomap_t;
  76
  77 struct xfs_iocore;
  78 struct xfs_inode;
  79 struct xfs_bmbt_irec;
  80
  81 extern int xfs_iomap(struct xfs_iocore *, xfs_off_t, ssize_t, int,
  82                      struct xfs_iomap *, int *);
  83 extern int xfs_iomap_write_direct(struct xfs_inode *, xfs_off_t, size_t,
  84                                   int, struct xfs_bmbt_irec *, int *, int);
  85 extern int xfs_iomap_write_delay(struct xfs_inode *, xfs_off_t, size_t, int,
  86                                  struct xfs_bmbt_irec *, int *);
  87 extern int xfs_iomap_write_allocate(struct xfs_inode *, xfs_off_t, size_t,
  88                                 struct xfs_bmbt_irec *, int *);
  89 extern int xfs_iomap_write_unwritten(struct xfs_inode *, xfs_off_t, size_t);
  90
  91 #endif /* __XFS_IOMAP_H__*/