xref: /openbmc/linux/fs/ocfs2/suballoc.h (revision 367b8112)
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,			/* bits_wanted */
32 			     u32,			/* min_bits */
33 			     u64,			/* max_block */
34 			     u16 *,			/* *bit_off */
35 			     u16 *);			/* *bits_found */
36 
37 struct ocfs2_alloc_context {
38 	struct inode *ac_inode;    /* which bitmap are we allocating from? */
39 	struct buffer_head *ac_bh; /* file entry bh */
40 	u32    ac_alloc_slot;   /* which slot are we allocating from? */
41 	u32    ac_bits_wanted;
42 	u32    ac_bits_given;
43 #define OCFS2_AC_USE_LOCAL 1
44 #define OCFS2_AC_USE_MAIN  2
45 #define OCFS2_AC_USE_INODE 3
46 #define OCFS2_AC_USE_META  4
47 	u32    ac_which;
48 
49 	/* these are used by the chain search */
50 	u16    ac_chain;
51 	int    ac_allow_chain_relink;
52 	group_search_t *ac_group_search;
53 
54 	u64    ac_last_group;
55 	u64    ac_max_block;  /* Highest block number to allocate. 0 is
56 				 is the same as ~0 - unlimited */
57 };
58 
59 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac);
60 static inline int ocfs2_alloc_context_bits_left(struct ocfs2_alloc_context *ac)
61 {
62 	return ac->ac_bits_wanted - ac->ac_bits_given;
63 }
64 
65 /*
66  * Please note that the caller must make sure that root_el is the root
67  * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
68  * the result may be wrong.
69  */
70 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
71 			       struct ocfs2_extent_list *root_el,
72 			       struct ocfs2_alloc_context **ac);
73 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
74 				      int blocks,
75 				      struct ocfs2_alloc_context **ac);
76 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
77 			    struct ocfs2_alloc_context **ac);
78 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
79 			   u32 bits_wanted,
80 			   struct ocfs2_alloc_context **ac);
81 
82 int ocfs2_claim_metadata(struct ocfs2_super *osb,
83 			 handle_t *handle,
84 			 struct ocfs2_alloc_context *ac,
85 			 u32 bits_wanted,
86 			 u16 *suballoc_bit_start,
87 			 u32 *num_bits,
88 			 u64 *blkno_start);
89 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
90 			  handle_t *handle,
91 			  struct ocfs2_alloc_context *ac,
92 			  u16 *suballoc_bit,
93 			  u64 *fe_blkno);
94 int ocfs2_claim_clusters(struct ocfs2_super *osb,
95 			 handle_t *handle,
96 			 struct ocfs2_alloc_context *ac,
97 			 u32 min_clusters,
98 			 u32 *cluster_start,
99 			 u32 *num_clusters);
100 /*
101  * Use this variant of ocfs2_claim_clusters to specify a maxiumum
102  * number of clusters smaller than the allocation reserved.
103  */
104 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
105 			   handle_t *handle,
106 			   struct ocfs2_alloc_context *ac,
107 			   u32 min_clusters,
108 			   u32 max_clusters,
109 			   u32 *cluster_start,
110 			   u32 *num_clusters);
111 
112 int ocfs2_free_suballoc_bits(handle_t *handle,
113 			     struct inode *alloc_inode,
114 			     struct buffer_head *alloc_bh,
115 			     unsigned int start_bit,
116 			     u64 bg_blkno,
117 			     unsigned int count);
118 int ocfs2_free_dinode(handle_t *handle,
119 		      struct inode *inode_alloc_inode,
120 		      struct buffer_head *inode_alloc_bh,
121 		      struct ocfs2_dinode *di);
122 int ocfs2_free_clusters(handle_t *handle,
123 			struct inode *bitmap_inode,
124 			struct buffer_head *bitmap_bh,
125 			u64 start_blk,
126 			unsigned int num_clusters);
127 
128 static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
129 {
130 	u64 group = block - (u64) bit;
131 
132 	return group;
133 }
134 
135 static inline u32 ocfs2_cluster_from_desc(struct ocfs2_super *osb,
136 					  u64 bg_blkno)
137 {
138 	/* This should work for all block group descriptors as only
139 	 * the 1st group descriptor of the cluster bitmap is
140 	 * different. */
141 
142 	if (bg_blkno == osb->first_cluster_group_blkno)
143 		return 0;
144 
145 	/* the rest of the block groups are located at the beginning
146 	 * of their 1st cluster, so a direct translation just
147 	 * works. */
148 	return ocfs2_blocks_to_clusters(osb->sb, bg_blkno);
149 }
150 
151 static inline int ocfs2_is_cluster_bitmap(struct inode *inode)
152 {
153 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
154 	return osb->bitmap_blkno == OCFS2_I(inode)->ip_blkno;
155 }
156 
157 /* This is for local alloc ONLY. Others should use the task-specific
158  * apis above. */
159 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
160 				      struct ocfs2_alloc_context *ac);
161 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac);
162 
163 /* given a cluster offset, calculate which block group it belongs to
164  * and return that block offset. */
165 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster);
166 
167 /* somewhat more expensive than our other checks, so use sparingly. */
168 int ocfs2_check_group_descriptor(struct super_block *sb,
169 				 struct ocfs2_dinode *di,
170 				 struct ocfs2_group_desc *gd);
171 int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_extent_tree *et,
172 			  u32 clusters_to_add, u32 extents_to_split,
173 			  struct ocfs2_alloc_context **data_ac,
174 			  struct ocfs2_alloc_context **meta_ac);
175 #endif /* _CHAINALLOC_H_ */
176