2 * Copyright (c) 2003-2005 Silicon Graphics, Inc.
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.
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.
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
18 #ifndef __XFS_IOMAP_H__
19 #define __XFS_IOMAP_H__
21 typedef enum { /* iomap_flags values */
22 IOMAP_READ = 0, /* mapping for a read */
23 IOMAP_DELAY = 0x04, /* mapping covers delalloc region */
24 IOMAP_UNWRITTEN = 0x20, /* mapping covers allocated */
25 /* but uninitialized file data */
26 IOMAP_NEW = 0x40 /* just allocate */
30 /* base extent manipulation calls */
31 BMAPI_READ = (1 << 0), /* read extents */
32 BMAPI_WRITE = (1 << 1), /* create extents */
33 BMAPI_ALLOCATE = (1 << 2), /* delayed allocate to real extents */
35 BMAPI_IGNSTATE = (1 << 4), /* ignore unwritten state on read */
36 BMAPI_DIRECT = (1 << 5), /* direct instead of buffered write */
37 BMAPI_MMAP = (1 << 6), /* allocate for mmap write */
38 BMAPI_TRYLOCK = (1 << 7), /* non-blocking request */
42 { BMAPI_READ, "READ" }, \
43 { BMAPI_WRITE, "WRITE" }, \
44 { BMAPI_ALLOCATE, "ALLOCATE" }, \
45 { BMAPI_IGNSTATE, "IGNSTATE" }, \
46 { BMAPI_DIRECT, "DIRECT" }, \
47 { BMAPI_MMAP, "MMAP" }, \
48 { BMAPI_TRYLOCK, "TRYLOCK" }
51 * xfs_iomap_t: File system I/O map
53 * The iomap_bn field is expressed in 512-byte blocks, and is where the
54 * mapping starts on disk.
56 * The iomap_offset, iomap_bsize and iomap_delta fields are in bytes.
57 * iomap_offset is the offset of the mapping in the file itself.
58 * iomap_bsize is the size of the mapping, iomap_delta is the
59 * desired data's offset into the mapping, given the offset supplied
60 * to the file I/O map routine.
62 * When a request is made to read beyond the logical end of the object,
63 * iomap_size may be set to 0, but iomap_offset and iomap_length should be set
64 * to the actual amount of underlying storage that has been allocated, if any.
67 typedef struct xfs_iomap {
68 xfs_daddr_t iomap_bn; /* first 512B blk of mapping */
69 xfs_off_t iomap_offset; /* offset of mapping, bytes */
70 xfs_off_t iomap_bsize; /* size of mapping, bytes */
71 iomap_flags_t iomap_flags;
77 extern int xfs_iomap(struct xfs_inode *, xfs_off_t, ssize_t, int,
78 struct xfs_iomap *, int *);
79 extern int xfs_iomap_write_direct(struct xfs_inode *, xfs_off_t, size_t,
80 int, struct xfs_bmbt_irec *, int *, int);
81 extern int xfs_iomap_write_delay(struct xfs_inode *, xfs_off_t, size_t, int,
82 struct xfs_bmbt_irec *, int *);
83 extern int xfs_iomap_write_allocate(struct xfs_inode *, xfs_off_t, size_t,
84 struct xfs_bmbt_irec *, int *);
85 extern int xfs_iomap_write_unwritten(struct xfs_inode *, xfs_off_t, size_t);
87 #endif /* __XFS_IOMAP_H__*/