release/src-rt-6.x.4708/linux/linux-2.6.36/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  */
  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, 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);
 172 int ocfs2_convert_inline_data_to_extents(struct inode *inode,
 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);
 177 void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
 178                                        int cancel);
 179 int ocfs2_flush_truncate_log(struct ocfs2_super *osb);
 180 int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
 181                                       int slot_num,
 182                                       struct ocfs2_dinode **tl_copy);
 183 int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
 184                                          struct ocfs2_dinode *tl_copy);
 185 int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb);
 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  */
 201 struct ocfs2_cached_dealloc_ctxt {
 202         struct ocfs2_per_slot_free_list         *c_first_suballocator;
 203         struct ocfs2_cached_block_free          *c_global_allocator;
 204 };
 205 static inline void ocfs2_init_dealloc_ctxt(struct ocfs2_cached_dealloc_ctxt *c)
 206 {
 207         c->c_first_suballocator = NULL;
 208         c->c_global_allocator = NULL;
 209 }
 210 int ocfs2_cache_cluster_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
 211                                 u64 blkno, unsigned int bit);
 212 int ocfs2_cache_block_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
 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
 222 struct ocfs2_truncate_context {
 223         struct ocfs2_cached_dealloc_ctxt tc_dealloc;
 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_prepare_truncate(struct ocfs2_super *osb,
 232                            struct inode *inode,
 233                            struct buffer_head *fe_bh,
 234                            struct ocfs2_truncate_context **tc);
 235 int ocfs2_commit_truncate(struct ocfs2_super *osb,
 236                           struct inode *inode,
 237                           struct buffer_head *di_bh);
 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_cpos_for_left_leaf(struct super_block *sb,
 323                                   struct ocfs2_path *path, u32 *cpos);
 324 int ocfs2_find_subtree_root(struct ocfs2_extent_tree *et,
 325                             struct ocfs2_path *left,
 326                             struct ocfs2_path *right);
 327 #endif /* OCFS2_ALLOC_H */