xref: /openbmc/linux/fs/ocfs2/alloc.h (revision a09d2831)
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  */
55 struct ocfs2_extent_tree_operations;
56 struct 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  */
70 void ocfs2_init_dinode_extent_tree(struct ocfs2_extent_tree *et,
71 				   struct ocfs2_caching_info *ci,
72 				   struct buffer_head *bh);
73 void ocfs2_init_xattr_tree_extent_tree(struct ocfs2_extent_tree *et,
74 				       struct ocfs2_caching_info *ci,
75 				       struct buffer_head *bh);
76 struct ocfs2_xattr_value_buf;
77 void ocfs2_init_xattr_value_extent_tree(struct ocfs2_extent_tree *et,
78 					struct ocfs2_caching_info *ci,
79 					struct ocfs2_xattr_value_buf *vb);
80 void ocfs2_init_dx_root_extent_tree(struct ocfs2_extent_tree *et,
81 				    struct ocfs2_caching_info *ci,
82 				    struct buffer_head *bh);
83 void 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  */
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 
104 enum ocfs2_alloc_restarted {
105 	RESTART_NONE = 0,
106 	RESTART_TRANS,
107 	RESTART_META
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);
117 struct ocfs2_cached_dealloc_ctxt;
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);
126 int 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);
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);
141 int 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 
146 int 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  */
156 static 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 
169 void ocfs2_dinode_new_extent_list(struct inode *inode, struct ocfs2_dinode *di);
170 void ocfs2_set_inode_data_inline(struct inode *inode, struct ocfs2_dinode *di);
171 int ocfs2_convert_inline_data_to_extents(struct inode *inode,
172 					 struct buffer_head *di_bh);
173 
174 int ocfs2_truncate_log_init(struct ocfs2_super *osb);
175 void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb);
176 void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
177 				       int cancel);
178 int ocfs2_flush_truncate_log(struct ocfs2_super *osb);
179 int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
180 				      int slot_num,
181 				      struct ocfs2_dinode **tl_copy);
182 int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
183 					 struct ocfs2_dinode *tl_copy);
184 int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb);
185 int ocfs2_truncate_log_append(struct ocfs2_super *osb,
186 			      handle_t *handle,
187 			      u64 start_blk,
188 			      unsigned int num_clusters);
189 int __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  */
200 struct ocfs2_cached_dealloc_ctxt {
201 	struct ocfs2_per_slot_free_list		*c_first_suballocator;
202 	struct ocfs2_cached_block_free 		*c_global_allocator;
203 };
204 static 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 }
209 int ocfs2_cache_cluster_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
210 				u64 blkno, unsigned int bit);
211 int ocfs2_cache_block_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
212 			      int type, int slot, u64 blkno,
213 			      unsigned int bit);
214 static inline int ocfs2_dealloc_has_cluster(struct ocfs2_cached_dealloc_ctxt *c)
215 {
216 	return c->c_global_allocator != NULL;
217 }
218 int ocfs2_run_deallocs(struct ocfs2_super *osb,
219 		       struct ocfs2_cached_dealloc_ctxt *ctxt);
220 
221 struct 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 
228 int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
229 				  u64 range_start, u64 range_end);
230 int ocfs2_prepare_truncate(struct ocfs2_super *osb,
231 			   struct inode *inode,
232 			   struct buffer_head *fe_bh,
233 			   struct ocfs2_truncate_context **tc);
234 int ocfs2_commit_truncate(struct ocfs2_super *osb,
235 			  struct inode *inode,
236 			  struct buffer_head *fe_bh,
237 			  struct ocfs2_truncate_context *tc);
238 int ocfs2_truncate_inline(struct inode *inode, struct buffer_head *di_bh,
239 			  unsigned int start, unsigned int end, int trunc);
240 
241 int ocfs2_find_leaf(struct ocfs2_caching_info *ci,
242 		    struct ocfs2_extent_list *root_el, u32 cpos,
243 		    struct buffer_head **leaf_bh);
244 int 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  */
249 static 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  */
269 static inline int ocfs2_is_empty_extent(struct ocfs2_extent_rec *rec)
270 {
271 	return !rec->e_leaf_clusters;
272 }
273 
274 int ocfs2_grab_pages(struct inode *inode, loff_t start, loff_t end,
275 		     struct page **pages, int *num);
276 void 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  */
286 struct ocfs2_path_item {
287 	struct buffer_head		*bh;
288 	struct ocfs2_extent_list	*el;
289 };
290 
291 #define OCFS2_MAX_PATH_DEPTH	5
292 
293 struct 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 
306 void ocfs2_reinit_path(struct ocfs2_path *path, int keep_root);
307 void ocfs2_free_path(struct ocfs2_path *path);
308 int ocfs2_find_path(struct ocfs2_caching_info *ci,
309 		    struct ocfs2_path *path,
310 		    u32 cpos);
311 struct ocfs2_path *ocfs2_new_path_from_path(struct ocfs2_path *path);
312 struct ocfs2_path *ocfs2_new_path_from_et(struct ocfs2_extent_tree *et);
313 int ocfs2_path_bh_journal_access(handle_t *handle,
314 				 struct ocfs2_caching_info *ci,
315 				 struct ocfs2_path *path,
316 				 int idx);
317 int ocfs2_journal_access_path(struct ocfs2_caching_info *ci,
318 			      handle_t *handle,
319 			      struct ocfs2_path *path);
320 int ocfs2_find_cpos_for_right_leaf(struct super_block *sb,
321 				   struct ocfs2_path *path, u32 *cpos);
322 int 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