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alloc.h
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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  */
58  struct buffer_head *et_root_bh;
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  */
71  struct ocfs2_caching_info *ci,
72  struct buffer_head *bh);
74  struct ocfs2_caching_info *ci,
75  struct buffer_head *bh);
78  struct ocfs2_caching_info *ci,
79  struct ocfs2_xattr_value_buf *vb);
81  struct ocfs2_caching_info *ci,
82  struct buffer_head *bh);
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  */
92 int ocfs2_read_extent_block(struct ocfs2_caching_info *ci, u64 eb_blkno,
93  struct buffer_head **bh);
94 
95 struct ocfs2_alloc_context;
96 int 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 
108 };
109 int 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);
118 struct ocfs2_path;
119 int 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);
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);
131 int 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);
137 int 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);
142  struct ocfs2_extent_tree *et,
143  u32 cpos, u32 phys_cpos, u32 len, int flags,
144  struct ocfs2_cached_dealloc_ctxt *dealloc,
145  u64 refcount_loc);
146 
147 int ocfs2_num_free_extents(struct ocfs2_super *osb,
148  struct ocfs2_extent_tree *et);
149 
150 /*
151  * how many new metadata chunks would an allocation need at maximum?
152  *
153  * Please note that the caller must make sure that root_el is the root
154  * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
155  * the result may be wrong.
156  */
157 static inline int ocfs2_extend_meta_needed(struct ocfs2_extent_list *root_el)
158 {
159  /*
160  * Rather than do all the work of determining how much we need
161  * (involves a ton of reads and locks), just ask for the
162  * maximal limit. That's a tree depth shift. So, one block for
163  * level of the tree (current l_tree_depth), one block for the
164  * new tree_depth==0 extent_block, and one block at the new
165  * top-of-the tree.
166  */
167  return le16_to_cpu(root_el->l_tree_depth) + 2;
168 }
169 
170 void ocfs2_dinode_new_extent_list(struct inode *inode, struct ocfs2_dinode *di);
171 void ocfs2_set_inode_data_inline(struct inode *inode, struct ocfs2_dinode *di);
173  struct buffer_head *di_bh);
174 
175 int ocfs2_truncate_log_init(struct ocfs2_super *osb);
176 void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb);
178  int cancel);
179 int ocfs2_flush_truncate_log(struct ocfs2_super *osb);
181  int slot_num,
182  struct ocfs2_dinode **tl_copy);
184  struct ocfs2_dinode *tl_copy);
186 int ocfs2_truncate_log_append(struct ocfs2_super *osb,
187  handle_t *handle,
188  u64 start_blk,
189  unsigned int num_clusters);
190 int __ocfs2_flush_truncate_log(struct ocfs2_super *osb);
191 
192 /*
193  * Process local structure which describes the block unlinks done
194  * during an operation. This is populated via
195  * ocfs2_cache_block_dealloc().
196  *
197  * ocfs2_run_deallocs() should be called after the potentially
198  * de-allocating routines. No journal handles should be open, and most
199  * locks should have been dropped.
200  */
204 };
205 static inline void ocfs2_init_dealloc_ctxt(struct ocfs2_cached_dealloc_ctxt *c)
206 {
209 }
211  u64 blkno, unsigned int bit);
213  int type, int slot, u64 suballoc, u64 blkno,
214  unsigned int bit);
215 static inline int ocfs2_dealloc_has_cluster(struct ocfs2_cached_dealloc_ctxt *c)
216 {
217  return c->c_global_allocator != NULL;
218 }
219 int ocfs2_run_deallocs(struct ocfs2_super *osb,
220  struct ocfs2_cached_dealloc_ctxt *ctxt);
221 
224  int tc_ext_alloc_locked; /* is it cluster locked? */
225  /* these get destroyed once it's passed to ocfs2_commit_truncate. */
226  struct buffer_head *tc_last_eb_bh;
227 };
228 
229 int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
230  u64 range_start, u64 range_end);
231 int ocfs2_commit_truncate(struct ocfs2_super *osb,
232  struct inode *inode,
233  struct buffer_head *di_bh);
234 int ocfs2_truncate_inline(struct inode *inode, struct buffer_head *di_bh,
235  unsigned int start, unsigned int end, int trunc);
236 
237 int ocfs2_find_leaf(struct ocfs2_caching_info *ci,
238  struct ocfs2_extent_list *root_el, u32 cpos,
239  struct buffer_head **leaf_bh);
240 int ocfs2_search_extent_list(struct ocfs2_extent_list *el, u32 v_cluster);
241 
242 int ocfs2_trim_fs(struct super_block *sb, struct fstrim_range *range);
243 /*
244  * Helper function to look at the # of clusters in an extent record.
245  */
246 static inline unsigned int ocfs2_rec_clusters(struct ocfs2_extent_list *el,
247  struct ocfs2_extent_rec *rec)
248 {
249  /*
250  * Cluster count in extent records is slightly different
251  * between interior nodes and leaf nodes. This is to support
252  * unwritten extents which need a flags field in leaf node
253  * records, thus shrinking the available space for a clusters
254  * field.
255  */
256  if (el->l_tree_depth)
257  return le32_to_cpu(rec->e_int_clusters);
258  else
259  return le16_to_cpu(rec->e_leaf_clusters);
260 }
261 
262 /*
263  * This is only valid for leaf nodes, which are the only ones that can
264  * have empty extents anyway.
265  */
266 static inline int ocfs2_is_empty_extent(struct ocfs2_extent_rec *rec)
267 {
268  return !rec->e_leaf_clusters;
269 }
270 
271 int ocfs2_grab_pages(struct inode *inode, loff_t start, loff_t end,
272  struct page **pages, int *num);
273 void ocfs2_map_and_dirty_page(struct inode *inode, handle_t *handle,
274  unsigned int from, unsigned int to,
275  struct page *page, int zero, u64 *phys);
276 /*
277  * Structures which describe a path through a btree, and functions to
278  * manipulate them.
279  *
280  * The idea here is to be as generic as possible with the tree
281  * manipulation code.
282  */
284  struct buffer_head *bh;
286 };
287 
288 #define OCFS2_MAX_PATH_DEPTH 5
289 
290 struct ocfs2_path {
294 };
295 
296 #define path_root_bh(_path) ((_path)->p_node[0].bh)
297 #define path_root_el(_path) ((_path)->p_node[0].el)
298 #define path_root_access(_path)((_path)->p_root_access)
299 #define path_leaf_bh(_path) ((_path)->p_node[(_path)->p_tree_depth].bh)
300 #define path_leaf_el(_path) ((_path)->p_node[(_path)->p_tree_depth].el)
301 #define path_num_items(_path) ((_path)->p_tree_depth + 1)
302 
303 void ocfs2_reinit_path(struct ocfs2_path *path, int keep_root);
304 void ocfs2_free_path(struct ocfs2_path *path);
305 int ocfs2_find_path(struct ocfs2_caching_info *ci,
306  struct ocfs2_path *path,
307  u32 cpos);
311  struct ocfs2_caching_info *ci,
312  struct ocfs2_path *path,
313  int idx);
315  handle_t *handle,
316  struct ocfs2_path *path);
318  struct ocfs2_path *path, u32 *cpos);
320  struct ocfs2_path *path, u32 *cpos);
322  struct ocfs2_path *left,
323  struct ocfs2_path *right);
324 #endif /* OCFS2_ALLOC_H */