LXR linux/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);
 320#endif /* OCFS2_ALLOC_H */
 321