1/*
2 * Copyright (c) 2000,2005 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_IALLOC_H__
19#define	__XFS_IALLOC_H__
20
21struct xfs_buf;
22struct xfs_dinode;
23struct xfs_mount;
24struct xfs_trans;
25
26/*
27 * Allocation parameters for inode allocation.
28 */
29#define	XFS_IALLOC_INODES(mp)	(mp)->m_ialloc_inos
30#define	XFS_IALLOC_BLOCKS(mp)	(mp)->m_ialloc_blks
31
32/*
33 * For small block file systems, move inodes in clusters of this size.
34 * When we don't have a lot of memory, however, we go a bit smaller
35 * to reduce the number of AGI and ialloc btree blocks we need to keep
36 * around for xfs_dilocate().  We choose which one to use in
37 * xfs_mount_int().
38 */
39#define	XFS_INODE_BIG_CLUSTER_SIZE	8192
40#define	XFS_INODE_SMALL_CLUSTER_SIZE	4096
41#define	XFS_INODE_CLUSTER_SIZE(mp)	(mp)->m_inode_cluster_size
42
43/*
44 * Make an inode pointer out of the buffer/offset.
45 */
46#define	XFS_MAKE_IPTR(mp,b,o)		xfs_make_iptr(mp,b,o)
47static inline struct xfs_dinode *
48xfs_make_iptr(struct xfs_mount *mp, struct xfs_buf *b, int o)
49{
50	return (xfs_dinode_t *)
51		(xfs_buf_offset(b, o << (mp)->m_sb.sb_inodelog));
52}
53
54/*
55 * Find a free (set) bit in the inode bitmask.
56 */
57#define	XFS_IALLOC_FIND_FREE(fp)	xfs_ialloc_find_free(fp)
58static inline int xfs_ialloc_find_free(xfs_inofree_t *fp)
59{
60	return xfs_lowbit64(*fp);
61}
62
63
64#ifdef __KERNEL__
65/*
66 * Allocate an inode on disk.
67 * Mode is used to tell whether the new inode will need space, and whether
68 * it is a directory.
69 *
70 * To work within the constraint of one allocation per transaction,
71 * xfs_dialloc() is designed to be called twice if it has to do an
72 * allocation to make more free inodes.  If an inode is
73 * available without an allocation, agbp would be set to the current
74 * agbp and alloc_done set to false.
75 * If an allocation needed to be done, agbp would be set to the
76 * inode header of the allocation group and alloc_done set to true.
77 * The caller should then commit the current transaction and allocate a new
78 * transaction.  xfs_dialloc() should then be called again with
79 * the agbp value returned from the previous call.
80 *
81 * Once we successfully pick an inode its number is returned and the
82 * on-disk data structures are updated.  The inode itself is not read
83 * in, since doing so would break ordering constraints with xfs_reclaim.
84 *
85 * *agbp should be set to NULL on the first call, *alloc_done set to FALSE.
86 */
87int					/* error */
88xfs_dialloc(
89	struct xfs_trans *tp,		/* transaction pointer */
90	xfs_ino_t	parent,		/* parent inode (directory) */
91	mode_t		mode,		/* mode bits for new inode */
92	int		okalloc,	/* ok to allocate more space */
93	struct xfs_buf	**agbp,		/* buf for a.g. inode header */
94	boolean_t	*alloc_done,	/* an allocation was done to replenish
95					   the free inodes */
96	xfs_ino_t	*inop);		/* inode number allocated */
97
98/*
99 * Free disk inode.  Carefully avoids touching the incore inode, all
100 * manipulations incore are the caller's responsibility.
101 * The on-disk inode is not changed by this operation, only the
102 * btree (free inode mask) is changed.
103 */
104int					/* error */
105xfs_difree(
106	struct xfs_trans *tp,		/* transaction pointer */
107	xfs_ino_t	inode,		/* inode to be freed */
108	struct xfs_bmap_free *flist,	/* extents to free */
109	int		*delete,	/* set if inode cluster was deleted */
110	xfs_ino_t	*first_ino);	/* first inode in deleted cluster */
111
112/*
113 * Return the location of the inode in bno/len/off,
114 * for mapping it into a buffer.
115 */
116int
117xfs_dilocate(
118	struct xfs_mount *mp,		/* file system mount structure */
119	struct xfs_trans *tp,		/* transaction pointer */
120	xfs_ino_t	ino,		/* inode to locate */
121	xfs_fsblock_t	*bno,		/* output: block containing inode */
122	int		*len,		/* output: num blocks in cluster*/
123	int		*off,		/* output: index in block of inode */
124	uint		flags);		/* flags for inode btree lookup */
125
126/*
127 * Compute and fill in value of m_in_maxlevels.
128 */
129void
130xfs_ialloc_compute_maxlevels(
131	struct xfs_mount *mp);		/* file system mount structure */
132
133/*
134 * Log specified fields for the ag hdr (inode section)
135 */
136void
137xfs_ialloc_log_agi(
138	struct xfs_trans *tp,		/* transaction pointer */
139	struct xfs_buf	*bp,		/* allocation group header buffer */
140	int		fields);	/* bitmask of fields to log */
141
142/*
143 * Read in the allocation group header (inode allocation section)
144 */
145int					/* error */
146xfs_ialloc_read_agi(
147	struct xfs_mount *mp,		/* file system mount structure */
148	struct xfs_trans *tp,		/* transaction pointer */
149	xfs_agnumber_t	agno,		/* allocation group number */
150	struct xfs_buf	**bpp);		/* allocation group hdr buf */
151
152#endif	/* __KERNEL__ */
153
154#endif	/* __XFS_IALLOC_H__ */
155