xref: /openbmc/linux/fs/xfs/libxfs/xfs_ialloc.h (revision 275876e2)
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 /* Calculate and return the number of filesystem blocks per inode cluster */
32 static inline int
33 xfs_icluster_size_fsb(
34 	struct xfs_mount	*mp)
35 {
36 	if (mp->m_sb.sb_blocksize >= mp->m_inode_cluster_size)
37 		return 1;
38 	return mp->m_inode_cluster_size >> mp->m_sb.sb_blocklog;
39 }
40 
41 /*
42  * Make an inode pointer out of the buffer/offset.
43  */
44 static inline struct xfs_dinode *
45 xfs_make_iptr(struct xfs_mount *mp, struct xfs_buf *b, int o)
46 {
47 	return (struct xfs_dinode *)
48 		(xfs_buf_offset(b, o << (mp)->m_sb.sb_inodelog));
49 }
50 
51 /*
52  * Allocate an inode on disk.
53  * Mode is used to tell whether the new inode will need space, and whether
54  * it is a directory.
55  *
56  * To work within the constraint of one allocation per transaction,
57  * xfs_dialloc() is designed to be called twice if it has to do an
58  * allocation to make more free inodes.  If an inode is
59  * available without an allocation, agbp would be set to the current
60  * agbp and alloc_done set to false.
61  * If an allocation needed to be done, agbp would be set to the
62  * inode header of the allocation group and alloc_done set to true.
63  * The caller should then commit the current transaction and allocate a new
64  * transaction.  xfs_dialloc() should then be called again with
65  * the agbp value returned from the previous call.
66  *
67  * Once we successfully pick an inode its number is returned and the
68  * on-disk data structures are updated.  The inode itself is not read
69  * in, since doing so would break ordering constraints with xfs_reclaim.
70  *
71  * *agbp should be set to NULL on the first call, *alloc_done set to FALSE.
72  */
73 int					/* error */
74 xfs_dialloc(
75 	struct xfs_trans *tp,		/* transaction pointer */
76 	xfs_ino_t	parent,		/* parent inode (directory) */
77 	umode_t		mode,		/* mode bits for new inode */
78 	int		okalloc,	/* ok to allocate more space */
79 	struct xfs_buf	**agbp,		/* buf for a.g. inode header */
80 	xfs_ino_t	*inop);		/* inode number allocated */
81 
82 /*
83  * Free disk inode.  Carefully avoids touching the incore inode, all
84  * manipulations incore are the caller's responsibility.
85  * The on-disk inode is not changed by this operation, only the
86  * btree (free inode mask) is changed.
87  */
88 int					/* error */
89 xfs_difree(
90 	struct xfs_trans *tp,		/* transaction pointer */
91 	xfs_ino_t	inode,		/* inode to be freed */
92 	struct xfs_bmap_free *flist,	/* extents to free */
93 	int		*deleted,	/* set if inode cluster was deleted */
94 	xfs_ino_t	*first_ino);	/* first inode in deleted cluster */
95 
96 /*
97  * Return the location of the inode in imap, for mapping it into a buffer.
98  */
99 int
100 xfs_imap(
101 	struct xfs_mount *mp,		/* file system mount structure */
102 	struct xfs_trans *tp,		/* transaction pointer */
103 	xfs_ino_t	ino,		/* inode to locate */
104 	struct xfs_imap	*imap,		/* location map structure */
105 	uint		flags);		/* flags for inode btree lookup */
106 
107 /*
108  * Compute and fill in value of m_in_maxlevels.
109  */
110 void
111 xfs_ialloc_compute_maxlevels(
112 	struct xfs_mount *mp);		/* file system mount structure */
113 
114 /*
115  * Log specified fields for the ag hdr (inode section)
116  */
117 void
118 xfs_ialloc_log_agi(
119 	struct xfs_trans *tp,		/* transaction pointer */
120 	struct xfs_buf	*bp,		/* allocation group header buffer */
121 	int		fields);	/* bitmask of fields to log */
122 
123 /*
124  * Read in the allocation group header (inode allocation section)
125  */
126 int					/* error */
127 xfs_ialloc_read_agi(
128 	struct xfs_mount *mp,		/* file system mount structure */
129 	struct xfs_trans *tp,		/* transaction pointer */
130 	xfs_agnumber_t	agno,		/* allocation group number */
131 	struct xfs_buf	**bpp);		/* allocation group hdr buf */
132 
133 /*
134  * Read in the allocation group header to initialise the per-ag data
135  * in the mount structure
136  */
137 int
138 xfs_ialloc_pagi_init(
139 	struct xfs_mount *mp,		/* file system mount structure */
140 	struct xfs_trans *tp,		/* transaction pointer */
141         xfs_agnumber_t  agno);		/* allocation group number */
142 
143 /*
144  * Lookup a record by ino in the btree given by cur.
145  */
146 int xfs_inobt_lookup(struct xfs_btree_cur *cur, xfs_agino_t ino,
147 		xfs_lookup_t dir, int *stat);
148 
149 /*
150  * Get the data from the pointed-to record.
151  */
152 int xfs_inobt_get_rec(struct xfs_btree_cur *cur,
153 		xfs_inobt_rec_incore_t *rec, int *stat);
154 
155 /*
156  * Inode chunk initialisation routine
157  */
158 int xfs_ialloc_inode_init(struct xfs_mount *mp, struct xfs_trans *tp,
159 			  struct list_head *buffer_list,
160 			  xfs_agnumber_t agno, xfs_agblock_t agbno,
161 			  xfs_agblock_t length, unsigned int gen);
162 
163 #endif	/* __XFS_IALLOC_H__ */
164