xref: /openbmc/linux/fs/ocfs2/suballoc.h (revision b627b4ed)
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 inode *dir,
92 			  struct buffer_head *parent_fe_bh,
93 			  struct ocfs2_alloc_context *ac,
94 			  u16 *suballoc_bit,
95 			  u64 *fe_blkno);
96 int ocfs2_claim_clusters(struct ocfs2_super *osb,
97 			 handle_t *handle,
98 			 struct ocfs2_alloc_context *ac,
99 			 u32 min_clusters,
100 			 u32 *cluster_start,
101 			 u32 *num_clusters);
102 /*
103  * Use this variant of ocfs2_claim_clusters to specify a maxiumum
104  * number of clusters smaller than the allocation reserved.
105  */
106 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
107 			   handle_t *handle,
108 			   struct ocfs2_alloc_context *ac,
109 			   u32 min_clusters,
110 			   u32 max_clusters,
111 			   u32 *cluster_start,
112 			   u32 *num_clusters);
113 
114 int ocfs2_free_suballoc_bits(handle_t *handle,
115 			     struct inode *alloc_inode,
116 			     struct buffer_head *alloc_bh,
117 			     unsigned int start_bit,
118 			     u64 bg_blkno,
119 			     unsigned int count);
120 int ocfs2_free_dinode(handle_t *handle,
121 		      struct inode *inode_alloc_inode,
122 		      struct buffer_head *inode_alloc_bh,
123 		      struct ocfs2_dinode *di);
124 int ocfs2_free_clusters(handle_t *handle,
125 			struct inode *bitmap_inode,
126 			struct buffer_head *bitmap_bh,
127 			u64 start_blk,
128 			unsigned int num_clusters);
129 
130 static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
131 {
132 	u64 group = block - (u64) bit;
133 
134 	return group;
135 }
136 
137 static inline u32 ocfs2_cluster_from_desc(struct ocfs2_super *osb,
138 					  u64 bg_blkno)
139 {
140 	/* This should work for all block group descriptors as only
141 	 * the 1st group descriptor of the cluster bitmap is
142 	 * different. */
143 
144 	if (bg_blkno == osb->first_cluster_group_blkno)
145 		return 0;
146 
147 	/* the rest of the block groups are located at the beginning
148 	 * of their 1st cluster, so a direct translation just
149 	 * works. */
150 	return ocfs2_blocks_to_clusters(osb->sb, bg_blkno);
151 }
152 
153 static inline int ocfs2_is_cluster_bitmap(struct inode *inode)
154 {
155 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
156 	return osb->bitmap_blkno == OCFS2_I(inode)->ip_blkno;
157 }
158 
159 /* This is for local alloc ONLY. Others should use the task-specific
160  * apis above. */
161 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
162 				      struct ocfs2_alloc_context *ac);
163 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac);
164 
165 /* given a cluster offset, calculate which block group it belongs to
166  * and return that block offset. */
167 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster);
168 
169 /*
170  * By default, ocfs2_read_group_descriptor() calls ocfs2_error() when it
171  * finds a problem.  A caller that wants to check a group descriptor
172  * without going readonly should read the block with ocfs2_read_block[s]()
173  * and then checking it with this function.  This is only resize, really.
174  * Everyone else should be using ocfs2_read_group_descriptor().
175  */
176 int ocfs2_check_group_descriptor(struct super_block *sb,
177 				 struct ocfs2_dinode *di,
178 				 struct buffer_head *bh);
179 /*
180  * Read a group descriptor block into *bh.  If *bh is NULL, a bh will be
181  * allocated.  This is a cached read.  The descriptor will be validated with
182  * ocfs2_validate_group_descriptor().
183  */
184 int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
185 				u64 gd_blkno, struct buffer_head **bh);
186 
187 int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_extent_tree *et,
188 			  u32 clusters_to_add, u32 extents_to_split,
189 			  struct ocfs2_alloc_context **data_ac,
190 			  struct ocfs2_alloc_context **meta_ac);
191 
192 int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res);
193 #endif /* _CHAINALLOC_H_ */
194