Root/fs/ocfs2/alloc.h

1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * alloc.h
5 *
6 * Function prototypes
7 *
8 * Copyright (C) 2002, 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 OCFS2_ALLOC_H
27#define OCFS2_ALLOC_H
28
29
30/*
31 * For xattr tree leaf, we limit the leaf byte size to be 64K.
32 */
33#define OCFS2_MAX_XATTR_TREE_LEAF_SIZE 65536
34
35/*
36 * ocfs2_extent_tree and ocfs2_extent_tree_operations are used to abstract
37 * the b-tree operations in ocfs2. Now all the b-tree operations are not
38 * limited to ocfs2_dinode only. Any data which need to allocate clusters
39 * to store can use b-tree. And it only needs to implement its ocfs2_extent_tree
40 * and operation.
41 *
42 * ocfs2_extent_tree becomes the first-class object for extent tree
43 * manipulation. Callers of the alloc.c code need to fill it via one of
44 * the ocfs2_init_*_extent_tree() operations below.
45 *
46 * ocfs2_extent_tree contains info for the root of the b-tree, it must have a
47 * root ocfs2_extent_list and a root_bh so that they can be used in the b-tree
48 * functions. It needs the ocfs2_caching_info structure associated with
49 * I/O on the tree. With metadata ecc, we now call different journal_access
50 * functions for each type of metadata, so it must have the
51 * root_journal_access function.
52 * ocfs2_extent_tree_operations abstract the normal operations we do for
53 * the root of extent b-tree.
54 */
55struct ocfs2_extent_tree_operations;
56struct ocfs2_extent_tree {
57    struct ocfs2_extent_tree_operations *et_ops;
58    struct buffer_head *et_root_bh;
59    struct ocfs2_extent_list *et_root_el;
60    struct ocfs2_caching_info *et_ci;
61    ocfs2_journal_access_func et_root_journal_access;
62    void *et_object;
63    unsigned int et_max_leaf_clusters;
64};
65
66/*
67 * ocfs2_init_*_extent_tree() will fill an ocfs2_extent_tree from the
68 * specified object buffer.
69 */
70void ocfs2_init_dinode_extent_tree(struct ocfs2_extent_tree *et,
71                   struct ocfs2_caching_info *ci,
72                   struct buffer_head *bh);
73void ocfs2_init_xattr_tree_extent_tree(struct ocfs2_extent_tree *et,
74                       struct ocfs2_caching_info *ci,
75                       struct buffer_head *bh);
76struct ocfs2_xattr_value_buf;
77void ocfs2_init_xattr_value_extent_tree(struct ocfs2_extent_tree *et,
78                    struct ocfs2_caching_info *ci,
79                    struct ocfs2_xattr_value_buf *vb);
80void ocfs2_init_dx_root_extent_tree(struct ocfs2_extent_tree *et,
81                    struct ocfs2_caching_info *ci,
82                    struct buffer_head *bh);
83void ocfs2_init_refcount_extent_tree(struct ocfs2_extent_tree *et,
84                     struct ocfs2_caching_info *ci,
85                     struct buffer_head *bh);
86
87/*
88 * Read an extent block into *bh. If *bh is NULL, a bh will be
89 * allocated. This is a cached read. The extent block will be validated
90 * with ocfs2_validate_extent_block().
91 */
92int ocfs2_read_extent_block(struct ocfs2_caching_info *ci, u64 eb_blkno,
93                struct buffer_head **bh);
94
95struct ocfs2_alloc_context;
96int ocfs2_insert_extent(handle_t *handle,
97            struct ocfs2_extent_tree *et,
98            u32 cpos,
99            u64 start_blk,
100            u32 new_clusters,
101            u8 flags,
102            struct ocfs2_alloc_context *meta_ac);
103
104enum ocfs2_alloc_restarted {
105    RESTART_NONE = 0,
106    RESTART_TRANS,
107    RESTART_META
108};
109int ocfs2_add_clusters_in_btree(handle_t *handle,
110                struct ocfs2_extent_tree *et,
111                u32 *logical_offset,
112                u32 clusters_to_add,
113                int mark_unwritten,
114                struct ocfs2_alloc_context *data_ac,
115                struct ocfs2_alloc_context *meta_ac,
116                enum ocfs2_alloc_restarted *reason_ret);
117struct ocfs2_cached_dealloc_ctxt;
118struct ocfs2_path;
119int ocfs2_split_extent(handle_t *handle,
120               struct ocfs2_extent_tree *et,
121               struct ocfs2_path *path,
122               int split_index,
123               struct ocfs2_extent_rec *split_rec,
124               struct ocfs2_alloc_context *meta_ac,
125               struct ocfs2_cached_dealloc_ctxt *dealloc);
126int ocfs2_mark_extent_written(struct inode *inode,
127                  struct ocfs2_extent_tree *et,
128                  handle_t *handle, u32 cpos, u32 len, u32 phys,
129                  struct ocfs2_alloc_context *meta_ac,
130                  struct ocfs2_cached_dealloc_ctxt *dealloc);
131int ocfs2_change_extent_flag(handle_t *handle,
132                 struct ocfs2_extent_tree *et,
133                 u32 cpos, u32 len, u32 phys,
134                 struct ocfs2_alloc_context *meta_ac,
135                 struct ocfs2_cached_dealloc_ctxt *dealloc,
136                 int new_flags, int clear_flags);
137int ocfs2_remove_extent(handle_t *handle, struct ocfs2_extent_tree *et,
138            u32 cpos, u32 len,
139            struct ocfs2_alloc_context *meta_ac,
140            struct ocfs2_cached_dealloc_ctxt *dealloc);
141int ocfs2_remove_btree_range(struct inode *inode,
142                 struct ocfs2_extent_tree *et,
143                 u32 cpos, u32 phys_cpos, u32 len,
144                 struct ocfs2_cached_dealloc_ctxt *dealloc);
145
146int ocfs2_num_free_extents(struct ocfs2_super *osb,
147               struct ocfs2_extent_tree *et);
148
149/*
150 * how many new metadata chunks would an allocation need at maximum?
151 *
152 * Please note that the caller must make sure that root_el is the root
153 * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
154 * the result may be wrong.
155 */
156static inline int ocfs2_extend_meta_needed(struct ocfs2_extent_list *root_el)
157{
158    /*
159     * Rather than do all the work of determining how much we need
160     * (involves a ton of reads and locks), just ask for the
161     * maximal limit. That's a tree depth shift. So, one block for
162     * level of the tree (current l_tree_depth), one block for the
163     * new tree_depth==0 extent_block, and one block at the new
164     * top-of-the tree.
165     */
166    return le16_to_cpu(root_el->l_tree_depth) + 2;
167}
168
169void ocfs2_dinode_new_extent_list(struct inode *inode, struct ocfs2_dinode *di);
170void ocfs2_set_inode_data_inline(struct inode *inode, struct ocfs2_dinode *di);
171int ocfs2_convert_inline_data_to_extents(struct inode *inode,
172                     struct buffer_head *di_bh);
173
174int ocfs2_truncate_log_init(struct ocfs2_super *osb);
175void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb);
176void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
177                       int cancel);
178int ocfs2_flush_truncate_log(struct ocfs2_super *osb);
179int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
180                      int slot_num,
181                      struct ocfs2_dinode **tl_copy);
182int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
183                     struct ocfs2_dinode *tl_copy);
184int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb);
185int ocfs2_truncate_log_append(struct ocfs2_super *osb,
186                  handle_t *handle,
187                  u64 start_blk,
188                  unsigned int num_clusters);
189int __ocfs2_flush_truncate_log(struct ocfs2_super *osb);
190
191/*
192 * Process local structure which describes the block unlinks done
193 * during an operation. This is populated via
194 * ocfs2_cache_block_dealloc().
195 *
196 * ocfs2_run_deallocs() should be called after the potentially
197 * de-allocating routines. No journal handles should be open, and most
198 * locks should have been dropped.
199 */
200struct ocfs2_cached_dealloc_ctxt {
201    struct ocfs2_per_slot_free_list *c_first_suballocator;
202    struct ocfs2_cached_block_free *c_global_allocator;
203};
204static inline void ocfs2_init_dealloc_ctxt(struct ocfs2_cached_dealloc_ctxt *c)
205{
206    c->c_first_suballocator = NULL;
207    c->c_global_allocator = NULL;
208}
209int ocfs2_cache_cluster_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
210                u64 blkno, unsigned int bit);
211int ocfs2_cache_block_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
212                  int type, int slot, u64 blkno,
213                  unsigned int bit);
214static inline int ocfs2_dealloc_has_cluster(struct ocfs2_cached_dealloc_ctxt *c)
215{
216    return c->c_global_allocator != NULL;
217}
218int ocfs2_run_deallocs(struct ocfs2_super *osb,
219               struct ocfs2_cached_dealloc_ctxt *ctxt);
220
221struct ocfs2_truncate_context {
222    struct ocfs2_cached_dealloc_ctxt tc_dealloc;
223    int tc_ext_alloc_locked; /* is it cluster locked? */
224    /* these get destroyed once it's passed to ocfs2_commit_truncate. */
225    struct buffer_head *tc_last_eb_bh;
226};
227
228int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
229                  u64 range_start, u64 range_end);
230int ocfs2_prepare_truncate(struct ocfs2_super *osb,
231               struct inode *inode,
232               struct buffer_head *fe_bh,
233               struct ocfs2_truncate_context **tc);
234int ocfs2_commit_truncate(struct ocfs2_super *osb,
235              struct inode *inode,
236              struct buffer_head *fe_bh,
237              struct ocfs2_truncate_context *tc);
238int ocfs2_truncate_inline(struct inode *inode, struct buffer_head *di_bh,
239              unsigned int start, unsigned int end, int trunc);
240
241int ocfs2_find_leaf(struct ocfs2_caching_info *ci,
242            struct ocfs2_extent_list *root_el, u32 cpos,
243            struct buffer_head **leaf_bh);
244int ocfs2_search_extent_list(struct ocfs2_extent_list *el, u32 v_cluster);
245
246/*
247 * Helper function to look at the # of clusters in an extent record.
248 */
249static inline unsigned int ocfs2_rec_clusters(struct ocfs2_extent_list *el,
250                          struct ocfs2_extent_rec *rec)
251{
252    /*
253     * Cluster count in extent records is slightly different
254     * between interior nodes and leaf nodes. This is to support
255     * unwritten extents which need a flags field in leaf node
256     * records, thus shrinking the available space for a clusters
257     * field.
258     */
259    if (el->l_tree_depth)
260        return le32_to_cpu(rec->e_int_clusters);
261    else
262        return le16_to_cpu(rec->e_leaf_clusters);
263}
264
265/*
266 * This is only valid for leaf nodes, which are the only ones that can
267 * have empty extents anyway.
268 */
269static inline int ocfs2_is_empty_extent(struct ocfs2_extent_rec *rec)
270{
271    return !rec->e_leaf_clusters;
272}
273
274int ocfs2_grab_pages(struct inode *inode, loff_t start, loff_t end,
275             struct page **pages, int *num);
276void ocfs2_map_and_dirty_page(struct inode *inode, handle_t *handle,
277                  unsigned int from, unsigned int to,
278                  struct page *page, int zero, u64 *phys);
279/*
280 * Structures which describe a path through a btree, and functions to
281 * manipulate them.
282 *
283 * The idea here is to be as generic as possible with the tree
284 * manipulation code.
285 */
286struct ocfs2_path_item {
287    struct buffer_head *bh;
288    struct ocfs2_extent_list *el;
289};
290
291#define OCFS2_MAX_PATH_DEPTH 5
292
293struct ocfs2_path {
294    int p_tree_depth;
295    ocfs2_journal_access_func p_root_access;
296    struct ocfs2_path_item p_node[OCFS2_MAX_PATH_DEPTH];
297};
298
299#define path_root_bh(_path) ((_path)->p_node[0].bh)
300#define path_root_el(_path) ((_path)->p_node[0].el)
301#define path_root_access(_path)((_path)->p_root_access)
302#define path_leaf_bh(_path) ((_path)->p_node[(_path)->p_tree_depth].bh)
303#define path_leaf_el(_path) ((_path)->p_node[(_path)->p_tree_depth].el)
304#define path_num_items(_path) ((_path)->p_tree_depth + 1)
305
306void ocfs2_reinit_path(struct ocfs2_path *path, int keep_root);
307void ocfs2_free_path(struct ocfs2_path *path);
308int ocfs2_find_path(struct ocfs2_caching_info *ci,
309            struct ocfs2_path *path,
310            u32 cpos);
311struct ocfs2_path *ocfs2_new_path_from_path(struct ocfs2_path *path);
312struct ocfs2_path *ocfs2_new_path_from_et(struct ocfs2_extent_tree *et);
313int ocfs2_path_bh_journal_access(handle_t *handle,
314                 struct ocfs2_caching_info *ci,
315                 struct ocfs2_path *path,
316                 int idx);
317int ocfs2_journal_access_path(struct ocfs2_caching_info *ci,
318                  handle_t *handle,
319                  struct ocfs2_path *path);
320int ocfs2_find_cpos_for_right_leaf(struct super_block *sb,
321                   struct ocfs2_path *path, u32 *cpos);
322int ocfs2_find_subtree_root(struct ocfs2_extent_tree *et,
323                struct ocfs2_path *left,
324                struct ocfs2_path *right);
325#endif /* OCFS2_ALLOC_H */
326

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