Root/fs/ocfs2/suballoc.h

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
29typedef 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
37struct 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
59void ocfs2_init_steal_slots(struct ocfs2_super *osb);
60void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac);
61static 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 */
71int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
72                   struct ocfs2_extent_list *root_el,
73                   struct ocfs2_alloc_context **ac);
74int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
75                      int blocks,
76                      struct ocfs2_alloc_context **ac);
77int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
78                struct ocfs2_alloc_context **ac);
79int ocfs2_reserve_clusters(struct ocfs2_super *osb,
80               u32 bits_wanted,
81               struct ocfs2_alloc_context **ac);
82
83int 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);
90int 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);
97int 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 */
107int __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
115int 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);
121int ocfs2_free_dinode(handle_t *handle,
122              struct inode *inode_alloc_inode,
123              struct buffer_head *inode_alloc_bh,
124              struct ocfs2_dinode *di);
125int 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);
130int 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
136static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
137{
138    u64 group = block - (u64) bit;
139
140    return group;
141}
142
143static 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
159static 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. */
167int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
168                      struct ocfs2_alloc_context *ac);
169void 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. */
173u64 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 */
182int 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 */
190int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
191                u64 gd_blkno, struct buffer_head **bh);
192
193int 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
198int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res);
199#endif /* _CHAINALLOC_H_ */
200

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