xref: /linux/fs/ocfs2/suballoc.h (revision a33f32244d8550da8b4a26e277ce07d5c6d158b5)
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_init_steal_slots(struct ocfs2_super *osb);
60 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac);
61 static inline int ocfs2_alloc_context_bits_left(struct ocfs2_alloc_context *ac)
62 {
63 	return ac->ac_bits_wanted - ac->ac_bits_given;
64 }
65 
66 /*
67  * Please note that the caller must make sure that root_el is the root
68  * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
69  * the result may be wrong.
70  */
71 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
72 			       struct ocfs2_extent_list *root_el,
73 			       struct ocfs2_alloc_context **ac);
74 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
75 				      int blocks,
76 				      struct ocfs2_alloc_context **ac);
77 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
78 			    struct ocfs2_alloc_context **ac);
79 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
80 			   u32 bits_wanted,
81 			   struct ocfs2_alloc_context **ac);
82 
83 int ocfs2_claim_metadata(struct ocfs2_super *osb,
84 			 handle_t *handle,
85 			 struct ocfs2_alloc_context *ac,
86 			 u32 bits_wanted,
87 			 u16 *suballoc_bit_start,
88 			 u32 *num_bits,
89 			 u64 *blkno_start);
90 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
91 			  handle_t *handle,
92 			  struct inode *dir,
93 			  struct buffer_head *parent_fe_bh,
94 			  struct ocfs2_alloc_context *ac,
95 			  u16 *suballoc_bit,
96 			  u64 *fe_blkno);
97 int ocfs2_claim_clusters(struct ocfs2_super *osb,
98 			 handle_t *handle,
99 			 struct ocfs2_alloc_context *ac,
100 			 u32 min_clusters,
101 			 u32 *cluster_start,
102 			 u32 *num_clusters);
103 /*
104  * Use this variant of ocfs2_claim_clusters to specify a maxiumum
105  * number of clusters smaller than the allocation reserved.
106  */
107 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
108 			   handle_t *handle,
109 			   struct ocfs2_alloc_context *ac,
110 			   u32 min_clusters,
111 			   u32 max_clusters,
112 			   u32 *cluster_start,
113 			   u32 *num_clusters);
114 
115 int ocfs2_free_suballoc_bits(handle_t *handle,
116 			     struct inode *alloc_inode,
117 			     struct buffer_head *alloc_bh,
118 			     unsigned int start_bit,
119 			     u64 bg_blkno,
120 			     unsigned int count);
121 int ocfs2_free_dinode(handle_t *handle,
122 		      struct inode *inode_alloc_inode,
123 		      struct buffer_head *inode_alloc_bh,
124 		      struct ocfs2_dinode *di);
125 int ocfs2_free_clusters(handle_t *handle,
126 			struct inode *bitmap_inode,
127 			struct buffer_head *bitmap_bh,
128 			u64 start_blk,
129 			unsigned int num_clusters);
130 int ocfs2_release_clusters(handle_t *handle,
131 			   struct inode *bitmap_inode,
132 			   struct buffer_head *bitmap_bh,
133 			   u64 start_blk,
134 			   unsigned int num_clusters);
135 
136 static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
137 {
138 	u64 group = block - (u64) bit;
139 
140 	return group;
141 }
142 
143 static inline u32 ocfs2_cluster_from_desc(struct ocfs2_super *osb,
144 					  u64 bg_blkno)
145 {
146 	/* This should work for all block group descriptors as only
147 	 * the 1st group descriptor of the cluster bitmap is
148 	 * different. */
149 
150 	if (bg_blkno == osb->first_cluster_group_blkno)
151 		return 0;
152 
153 	/* the rest of the block groups are located at the beginning
154 	 * of their 1st cluster, so a direct translation just
155 	 * works. */
156 	return ocfs2_blocks_to_clusters(osb->sb, bg_blkno);
157 }
158 
159 static inline int ocfs2_is_cluster_bitmap(struct inode *inode)
160 {
161 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
162 	return osb->bitmap_blkno == OCFS2_I(inode)->ip_blkno;
163 }
164 
165 /* This is for local alloc ONLY. Others should use the task-specific
166  * apis above. */
167 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
168 				      struct ocfs2_alloc_context *ac);
169 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac);
170 
171 /* given a cluster offset, calculate which block group it belongs to
172  * and return that block offset. */
173 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster);
174 
175 /*
176  * By default, ocfs2_read_group_descriptor() calls ocfs2_error() when it
177  * finds a problem.  A caller that wants to check a group descriptor
178  * without going readonly should read the block with ocfs2_read_block[s]()
179  * and then checking it with this function.  This is only resize, really.
180  * Everyone else should be using ocfs2_read_group_descriptor().
181  */
182 int ocfs2_check_group_descriptor(struct super_block *sb,
183 				 struct ocfs2_dinode *di,
184 				 struct buffer_head *bh);
185 /*
186  * Read a group descriptor block into *bh.  If *bh is NULL, a bh will be
187  * allocated.  This is a cached read.  The descriptor will be validated with
188  * ocfs2_validate_group_descriptor().
189  */
190 int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
191 				u64 gd_blkno, struct buffer_head **bh);
192 
193 int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_extent_tree *et,
194 			  u32 clusters_to_add, u32 extents_to_split,
195 			  struct ocfs2_alloc_context **data_ac,
196 			  struct ocfs2_alloc_context **meta_ac);
197 
198 int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res);
199 #endif /* _CHAINALLOC_H_ */
200