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,
131				struct xfs_buf *);
132void		xfs_idestroy_fork(struct xfs_inode *, int);
133void		xfs_idata_realloc(struct xfs_inode *, int, int);
134void		xfs_iroot_realloc(struct xfs_inode *, int, int);
135int		xfs_iread_extents(struct xfs_trans *, struct xfs_inode *, int);
136int		xfs_iextents_copy(struct xfs_inode *, struct xfs_bmbt_rec *,
137				  int);
138
139struct xfs_bmbt_rec_host *
140		xfs_iext_get_ext(struct xfs_ifork *, xfs_extnum_t);
141void		xfs_iext_insert(struct xfs_inode *, xfs_extnum_t, xfs_extnum_t,
142				struct xfs_bmbt_irec *, int);
143void		xfs_iext_add(struct xfs_ifork *, xfs_extnum_t, int);
144void		xfs_iext_add_indirect_multi(struct xfs_ifork *, int,
145					    xfs_extnum_t, int);
146void		xfs_iext_remove(struct xfs_inode *, xfs_extnum_t, int, int);
147void		xfs_iext_remove_inline(struct xfs_ifork *, xfs_extnum_t, int);
148void		xfs_iext_remove_direct(struct xfs_ifork *, xfs_extnum_t, int);
149void		xfs_iext_remove_indirect(struct xfs_ifork *, xfs_extnum_t, int);
150void		xfs_iext_realloc_direct(struct xfs_ifork *, int);
151void		xfs_iext_direct_to_inline(struct xfs_ifork *, xfs_extnum_t);
152void		xfs_iext_inline_to_direct(struct xfs_ifork *, int);
153void		xfs_iext_destroy(struct xfs_ifork *);
154struct xfs_bmbt_rec_host *
155		xfs_iext_bno_to_ext(struct xfs_ifork *, xfs_fileoff_t, int *);
156struct xfs_ext_irec *
157		xfs_iext_bno_to_irec(struct xfs_ifork *, xfs_fileoff_t, int *);
158struct xfs_ext_irec *
159		xfs_iext_idx_to_irec(struct xfs_ifork *, xfs_extnum_t *, int *,
160				     int);
161void		xfs_iext_irec_init(struct xfs_ifork *);
162struct xfs_ext_irec *
163		xfs_iext_irec_new(struct xfs_ifork *, int);
164void		xfs_iext_irec_remove(struct xfs_ifork *, int);
165void		xfs_iext_irec_compact(struct xfs_ifork *);
166void		xfs_iext_irec_compact_pages(struct xfs_ifork *);
167void		xfs_iext_irec_compact_full(struct xfs_ifork *);
168void		xfs_iext_irec_update_extoffs(struct xfs_ifork *, int, int);
169
170extern struct kmem_zone	*xfs_ifork_zone;
171
172#endif	/* __XFS_INODE_FORK_H__ */