xref: /linux/fs/ocfs2/suballoc.h (revision 8b4a40809e5330c9da5d20107d693d92d73b31dc)
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * suballoc.h
5  *
6  * Defines sub allocator api
7  *
8  * Copyright (C) 2003, 2004 Oracle.  All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public
12  * License as published by the Free Software Foundation; either
13  * version 2 of the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public
21  * License along with this program; if not, write to the
22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23  * Boston, MA 021110-1307, USA.
24  */
25 
26 #ifndef _CHAINALLOC_H_
27 #define _CHAINALLOC_H_
28 
29 typedef int (group_search_t)(struct inode *,
30 			     struct buffer_head *,
31 			     u32,
32 			     u32,
33 			     u16 *,
34 			     u16 *);
35 
36 struct ocfs2_alloc_context {
37 	struct inode *ac_inode;    /* which bitmap are we allocating from? */
38 	struct buffer_head *ac_bh; /* file entry bh */
39 	u32    ac_bits_wanted;
40 	u32    ac_bits_given;
41 #define OCFS2_AC_USE_LOCAL 1
42 #define OCFS2_AC_USE_MAIN  2
43 #define OCFS2_AC_USE_INODE 3
44 #define OCFS2_AC_USE_META  4
45 	u32    ac_which;
46 
47 	/* these are used by the chain search */
48 	u16    ac_chain;
49 	int    ac_allow_chain_relink;
50 	group_search_t *ac_group_search;
51 
52 	u64    ac_last_group;
53 };
54 
55 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac);
56 static inline int ocfs2_alloc_context_bits_left(struct ocfs2_alloc_context *ac)
57 {
58 	return ac->ac_bits_wanted - ac->ac_bits_given;
59 }
60 
61 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
62 			       struct ocfs2_dinode *fe,
63 			       struct ocfs2_alloc_context **ac);
64 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
65 			    struct ocfs2_alloc_context **ac);
66 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
67 			   u32 bits_wanted,
68 			   struct ocfs2_alloc_context **ac);
69 
70 int ocfs2_claim_metadata(struct ocfs2_super *osb,
71 			 handle_t *handle,
72 			 struct ocfs2_alloc_context *ac,
73 			 u32 bits_wanted,
74 			 u16 *suballoc_bit_start,
75 			 u32 *num_bits,
76 			 u64 *blkno_start);
77 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
78 			  handle_t *handle,
79 			  struct ocfs2_alloc_context *ac,
80 			  u16 *suballoc_bit,
81 			  u64 *fe_blkno);
82 int ocfs2_claim_clusters(struct ocfs2_super *osb,
83 			 handle_t *handle,
84 			 struct ocfs2_alloc_context *ac,
85 			 u32 min_clusters,
86 			 u32 *cluster_start,
87 			 u32 *num_clusters);
88 
89 int ocfs2_free_suballoc_bits(handle_t *handle,
90 			     struct inode *alloc_inode,
91 			     struct buffer_head *alloc_bh,
92 			     unsigned int start_bit,
93 			     u64 bg_blkno,
94 			     unsigned int count);
95 int ocfs2_free_dinode(handle_t *handle,
96 		      struct inode *inode_alloc_inode,
97 		      struct buffer_head *inode_alloc_bh,
98 		      struct ocfs2_dinode *di);
99 int ocfs2_free_clusters(handle_t *handle,
100 			struct inode *bitmap_inode,
101 			struct buffer_head *bitmap_bh,
102 			u64 start_blk,
103 			unsigned int num_clusters);
104 
105 static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
106 {
107 	u64 group = block - (u64) bit;
108 
109 	return group;
110 }
111 
112 static inline u32 ocfs2_cluster_from_desc(struct ocfs2_super *osb,
113 					  u64 bg_blkno)
114 {
115 	/* This should work for all block group descriptors as only
116 	 * the 1st group descriptor of the cluster bitmap is
117 	 * different. */
118 
119 	if (bg_blkno == osb->first_cluster_group_blkno)
120 		return 0;
121 
122 	/* the rest of the block groups are located at the beginning
123 	 * of their 1st cluster, so a direct translation just
124 	 * works. */
125 	return ocfs2_blocks_to_clusters(osb->sb, bg_blkno);
126 }
127 
128 static inline int ocfs2_is_cluster_bitmap(struct inode *inode)
129 {
130 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
131 	return osb->bitmap_blkno == OCFS2_I(inode)->ip_blkno;
132 }
133 
134 /* This is for local alloc ONLY. Others should use the task-specific
135  * apis above. */
136 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
137 				      struct ocfs2_alloc_context *ac);
138 
139 #endif /* _CHAINALLOC_H_ */
140