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_INODE_FORK_H__
19#define	__XFS_INODE_FORK_H__
20
21struct xfs_inode_log_item;
22struct xfs_dinode;
23
24/*
25 * The following xfs_ext_irec_t struct introduces a second (top) level
26 * to the in-core extent allocation scheme. These structs are allocated
27 * in a contiguous block, creating an indirection array where each entry
28 * (irec) contains a pointer to a buffer of in-core extent records which
29 * it manages. Each extent buffer is 4k in size, since 4k is the system
30 * page size on Linux i386 and systems with larger page sizes don't seem
31 * to gain much, if anything, by using their native page size as the
32 * extent buffer size. Also, using 4k extent buffers everywhere provides
33 * a consistent interface for CXFS across different platforms.
34 *
35 * There is currently no limit on the number of irec's (extent lists)
36 * allowed, so heavily fragmented files may require an indirection array
37 * which spans multiple system pages of memory. The number of extents
38 * which would require this amount of contiguous memory is very large
39 * and should not cause problems in the foreseeable future. However,
40 * if the memory needed for the contiguous array ever becomes a problem,
41 * it is possible that a third level of indirection may be required.
42 */
43typedef struct xfs_ext_irec {
44	xfs_bmbt_rec_host_t *er_extbuf;	/* block of extent records */
45	xfs_extnum_t	er_extoff;	/* extent offset in file */
46	xfs_extnum_t	er_extcount;	/* number of extents in page/block */
47} xfs_ext_irec_t;
48
49/*
50 * File incore extent information, present for each of data & attr forks.
51 */
52#define	XFS_IEXT_BUFSZ		4096
53#define	XFS_LINEAR_EXTS		(XFS_IEXT_BUFSZ / (uint)sizeof(xfs_bmbt_rec_t))
54#define	XFS_INLINE_EXTS		2
55#define	XFS_INLINE_DATA		32
56typedef struct xfs_ifork {
57	int			if_bytes;	/* bytes in if_u1 */
58	int			if_real_bytes;	/* bytes allocated in if_u1 */
59	struct xfs_btree_block	*if_broot;	/* file's incore btree root */
60	short			if_broot_bytes;	/* bytes allocated for root */
61	unsigned char		if_flags;	/* per-fork flags */
62	union {
63		xfs_bmbt_rec_host_t *if_extents;/* linear map file exts */
64		xfs_ext_irec_t	*if_ext_irec;	/* irec map file exts */
65		char		*if_data;	/* inline file data */
66	} if_u1;
67	union {
68		xfs_bmbt_rec_host_t if_inline_ext[XFS_INLINE_EXTS];
69						/* very small file extents */
70		char		if_inline_data[XFS_INLINE_DATA];
71						/* very small file data */
72		xfs_dev_t	if_rdev;	/* dev number if special */
73		uuid_t		if_uuid;	/* mount point value */
74	} if_u2;
75} xfs_ifork_t;
76
77/*
78 * Per-fork incore inode flags.
79 */
80#define	XFS_IFINLINE	0x01	/* Inline data is read in */
81#define	XFS_IFEXTENTS	0x02	/* All extent pointers are read in */
82#define	XFS_IFBROOT	0x04	/* i_broot points to the bmap b-tree root */
83#define	XFS_IFEXTIREC	0x08	/* Indirection array of extent blocks */
84
85/*
86 * Fork handling.
87 */
88
89#define XFS_IFORK_Q(ip)			((ip)->i_d.di_forkoff != 0)
90#define XFS_IFORK_BOFF(ip)		((int)((ip)->i_d.di_forkoff << 3))
91
92#define XFS_IFORK_PTR(ip,w)		\
93	((w) == XFS_DATA_FORK ? \
94		&(ip)->i_df : \
95		(ip)->i_afp)
96#define XFS_IFORK_DSIZE(ip) \
97	(XFS_IFORK_Q(ip) ? \
98		XFS_IFORK_BOFF(ip) : \
99		XFS_LITINO((ip)->i_mount, (ip)->i_d.di_version))
100#define XFS_IFORK_ASIZE(ip) \
101	(XFS_IFORK_Q(ip) ? \
102		XFS_LITINO((ip)->i_mount, (ip)->i_d.di_version) - \
103			XFS_IFORK_BOFF(ip) : \
104		0)
105#define XFS_IFORK_SIZE(ip,w) \
106	((w) == XFS_DATA_FORK ? \
107		XFS_IFORK_DSIZE(ip) : \
108		XFS_IFORK_ASIZE(ip))
109#define XFS_IFORK_FORMAT(ip,w) \
110	((w) == XFS_DATA_FORK ? \
111		(ip)->i_d.di_format : \
112		(ip)->i_d.di_aformat)
113#define XFS_IFORK_FMT_SET(ip,w,n) \
114	((w) == XFS_DATA_FORK ? \
115		((ip)->i_d.di_format = (n)) : \
116		((ip)->i_d.di_aformat = (n)))
117#define XFS_IFORK_NEXTENTS(ip,w) \
118	((w) == XFS_DATA_FORK ? \
119		(ip)->i_d.di_nextents : \
120		(ip)->i_d.di_anextents)
121#define XFS_IFORK_NEXT_SET(ip,w,n) \
122	((w) == XFS_DATA_FORK ? \
123		((ip)->i_d.di_nextents = (n)) : \
124		((ip)->i_d.di_anextents = (n)))
125#define XFS_IFORK_MAXEXT(ip, w) \
126	(XFS_IFORK_SIZE(ip, w) / sizeof(xfs_bmbt_rec_t))
127
128int		xfs_iformat_fork(struct xfs_inode *, struct xfs_dinode *);
129void		xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
130				struct xfs_inode_log_item *, int);
131void		xfs_idestroy_fork(struct xfs_inode *, int);
132void		xfs_idata_realloc(struct xfs_inode *, int, int);
133void		xfs_iroot_realloc(struct xfs_inode *, int, int);
134int		xfs_iread_extents(struct xfs_trans *, struct xfs_inode *, int);
135int		xfs_iextents_copy(struct xfs_inode *, struct xfs_bmbt_rec *,
136				  int);
137
138struct xfs_bmbt_rec_host *
139		xfs_iext_get_ext(struct xfs_ifork *, xfs_extnum_t);
140void		xfs_iext_insert(struct xfs_inode *, xfs_extnum_t, xfs_extnum_t,
141				struct xfs_bmbt_irec *, int);
142void		xfs_iext_add(struct xfs_ifork *, xfs_extnum_t, int);
143void		xfs_iext_add_indirect_multi(struct xfs_ifork *, int,
144					    xfs_extnum_t, int);
145void		xfs_iext_remove(struct xfs_inode *, xfs_extnum_t, int, int);
146void		xfs_iext_remove_inline(struct xfs_ifork *, xfs_extnum_t, int);
147void		xfs_iext_remove_direct(struct xfs_ifork *, xfs_extnum_t, int);
148void		xfs_iext_remove_indirect(struct xfs_ifork *, xfs_extnum_t, int);
149void		xfs_iext_realloc_direct(struct xfs_ifork *, int);
150void		xfs_iext_direct_to_inline(struct xfs_ifork *, xfs_extnum_t);
151void		xfs_iext_inline_to_direct(struct xfs_ifork *, int);
152void		xfs_iext_destroy(struct xfs_ifork *);
153struct xfs_bmbt_rec_host *
154		xfs_iext_bno_to_ext(struct xfs_ifork *, xfs_fileoff_t, int *);
155struct xfs_ext_irec *
156		xfs_iext_bno_to_irec(struct xfs_ifork *, xfs_fileoff_t, int *);
157struct xfs_ext_irec *
158		xfs_iext_idx_to_irec(struct xfs_ifork *, xfs_extnum_t *, int *,
159				     int);
160void		xfs_iext_irec_init(struct xfs_ifork *);
161struct xfs_ext_irec *
162		xfs_iext_irec_new(struct xfs_ifork *, int);
163void		xfs_iext_irec_remove(struct xfs_ifork *, int);
164void		xfs_iext_irec_compact(struct xfs_ifork *);
165void		xfs_iext_irec_compact_pages(struct xfs_ifork *);
166void		xfs_iext_irec_compact_full(struct xfs_ifork *);
167void		xfs_iext_irec_update_extoffs(struct xfs_ifork *, int, int);
168
169extern struct kmem_zone	*xfs_ifork_zone;
170
171#endif	/* __XFS_INODE_FORK_H__ */
172