xref: /linux/fs/xfs/libxfs/xfs_ialloc.h (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
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 
21 struct xfs_buf;
22 struct xfs_dinode;
23 struct xfs_imap;
24 struct xfs_mount;
25 struct xfs_trans;
26 struct xfs_btree_cur;
27 
28 /* Move inodes in clusters of this size */
29 #define	XFS_INODE_BIG_CLUSTER_SIZE	8192
30 
31 struct xfs_icluster {
32 	bool		deleted;	/* record is deleted */
33 	xfs_ino_t	first_ino;	/* first inode number */
34 	uint64_t	alloc;		/* inode phys. allocation bitmap for
35 					 * sparse chunks */
36 };
37 
38 /* Calculate and return the number of filesystem blocks per inode cluster */
39 static inline int
40 xfs_icluster_size_fsb(
41 	struct xfs_mount	*mp)
42 {
43 	if (mp->m_sb.sb_blocksize >= mp->m_inode_cluster_size)
44 		return 1;
45 	return mp->m_inode_cluster_size >> mp->m_sb.sb_blocklog;
46 }
47 
48 /*
49  * Make an inode pointer out of the buffer/offset.
50  */
51 static inline struct xfs_dinode *
52 xfs_make_iptr(struct xfs_mount *mp, struct xfs_buf *b, int o)
53 {
54 	return xfs_buf_offset(b, o << (mp)->m_sb.sb_inodelog);
55 }
56 
57 /*
58  * Allocate an inode on disk.
59  * Mode is used to tell whether the new inode will need space, and whether
60  * it is a directory.
61  *
62  * To work within the constraint of one allocation per transaction,
63  * xfs_dialloc() is designed to be called twice if it has to do an
64  * allocation to make more free inodes.  If an inode is
65  * available without an allocation, agbp would be set to the current
66  * agbp and alloc_done set to false.
67  * If an allocation needed to be done, agbp would be set to the
68  * inode header of the allocation group and alloc_done set to true.
69  * The caller should then commit the current transaction and allocate a new
70  * transaction.  xfs_dialloc() should then be called again with
71  * the agbp value returned from the previous call.
72  *
73  * Once we successfully pick an inode its number is returned and the
74  * on-disk data structures are updated.  The inode itself is not read
75  * in, since doing so would break ordering constraints with xfs_reclaim.
76  *
77  * *agbp should be set to NULL on the first call, *alloc_done set to FALSE.
78  */
79 int					/* error */
80 xfs_dialloc(
81 	struct xfs_trans *tp,		/* transaction pointer */
82 	xfs_ino_t	parent,		/* parent inode (directory) */
83 	umode_t		mode,		/* mode bits for new inode */
84 	int		okalloc,	/* ok to allocate more space */
85 	struct xfs_buf	**agbp,		/* buf for a.g. inode header */
86 	xfs_ino_t	*inop);		/* inode number allocated */
87 
88 /*
89  * Free disk inode.  Carefully avoids touching the incore inode, all
90  * manipulations incore are the caller's responsibility.
91  * The on-disk inode is not changed by this operation, only the
92  * btree (free inode mask) is changed.
93  */
94 int					/* error */
95 xfs_difree(
96 	struct xfs_trans *tp,		/* transaction pointer */
97 	xfs_ino_t	inode,		/* inode to be freed */
98 	struct xfs_defer_ops *dfops,	/* extents to free */
99 	struct xfs_icluster *ifree);	/* cluster info if deleted */
100 
101 /*
102  * Return the location of the inode in imap, for mapping it into a buffer.
103  */
104 int
105 xfs_imap(
106 	struct xfs_mount *mp,		/* file system mount structure */
107 	struct xfs_trans *tp,		/* transaction pointer */
108 	xfs_ino_t	ino,		/* inode to locate */
109 	struct xfs_imap	*imap,		/* location map structure */
110 	uint		flags);		/* flags for inode btree lookup */
111 
112 /*
113  * Compute and fill in value of m_in_maxlevels.
114  */
115 void
116 xfs_ialloc_compute_maxlevels(
117 	struct xfs_mount *mp);		/* file system mount structure */
118 
119 /*
120  * Log specified fields for the ag hdr (inode section)
121  */
122 void
123 xfs_ialloc_log_agi(
124 	struct xfs_trans *tp,		/* transaction pointer */
125 	struct xfs_buf	*bp,		/* allocation group header buffer */
126 	int		fields);	/* bitmask of fields to log */
127 
128 /*
129  * Read in the allocation group header (inode allocation section)
130  */
131 int					/* error */
132 xfs_ialloc_read_agi(
133 	struct xfs_mount *mp,		/* file system mount structure */
134 	struct xfs_trans *tp,		/* transaction pointer */
135 	xfs_agnumber_t	agno,		/* allocation group number */
136 	struct xfs_buf	**bpp);		/* allocation group hdr buf */
137 
138 /*
139  * Read in the allocation group header to initialise the per-ag data
140  * in the mount structure
141  */
142 int
143 xfs_ialloc_pagi_init(
144 	struct xfs_mount *mp,		/* file system mount structure */
145 	struct xfs_trans *tp,		/* transaction pointer */
146         xfs_agnumber_t  agno);		/* allocation group number */
147 
148 /*
149  * Lookup a record by ino in the btree given by cur.
150  */
151 int xfs_inobt_lookup(struct xfs_btree_cur *cur, xfs_agino_t ino,
152 		xfs_lookup_t dir, int *stat);
153 
154 /*
155  * Get the data from the pointed-to record.
156  */
157 int xfs_inobt_get_rec(struct xfs_btree_cur *cur,
158 		xfs_inobt_rec_incore_t *rec, int *stat);
159 
160 /*
161  * Inode chunk initialisation routine
162  */
163 int xfs_ialloc_inode_init(struct xfs_mount *mp, struct xfs_trans *tp,
164 			  struct list_head *buffer_list, int icount,
165 			  xfs_agnumber_t agno, xfs_agblock_t agbno,
166 			  xfs_agblock_t length, unsigned int gen);
167 
168 int xfs_read_agi(struct xfs_mount *mp, struct xfs_trans *tp,
169 		xfs_agnumber_t agno, struct xfs_buf **bpp);
170 
171 
172 #endif	/* __XFS_IALLOC_H__ */
173