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
24typedef 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
35typedef 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
68typedef 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
77struct xfs_iocore;
78struct xfs_inode;
79struct xfs_bmbt_irec;
80
81extern int xfs_iomap(struct xfs_iocore *, xfs_off_t, ssize_t, int,
82		     struct xfs_iomap *, int *);
83extern int xfs_iomap_write_direct(struct xfs_inode *, xfs_off_t, size_t,
84				  int, struct xfs_bmbt_irec *, int *, int);
85extern int xfs_iomap_write_delay(struct xfs_inode *, xfs_off_t, size_t, int,
86				 struct xfs_bmbt_irec *, int *);
87extern int xfs_iomap_write_allocate(struct xfs_inode *, xfs_off_t, size_t,
88				struct xfs_bmbt_irec *, int *);
89extern int xfs_iomap_write_unwritten(struct xfs_inode *, xfs_off_t, size_t);
90
91#endif /* __XFS_IOMAP_H__*/
92