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.  With metadata ecc, we now call different journal_access
  49  * functions for each type of metadata, so it must have the
  50  * root_journal_access function.
  51  * ocfs2_extent_tree_operations abstract the normal operations we do for
  52  * the root of extent b-tree.
  53  */
  54 struct ocfs2_extent_tree_operations;
  55 struct ocfs2_extent_tree {
  56         struct ocfs2_extent_tree_operations     *et_ops;
  57         struct buffer_head                      *et_root_bh;
  58         struct ocfs2_extent_list                *et_root_el;
  59         ocfs2_journal_access_func               et_root_journal_access;
  60         void                                    *et_object;
  61         unsigned int                            et_max_leaf_clusters;
  62 };
  63
  64 /*
  65  * ocfs2_init_*_extent_tree() will fill an ocfs2_extent_tree from the
  66  * specified object buffer.
  67  */
  68 void ocfs2_init_dinode_extent_tree(struct ocfs2_extent_tree *et,
  69                                    struct inode *inode,
  70                                    struct buffer_head *bh);
  71 void ocfs2_init_xattr_tree_extent_tree(struct ocfs2_extent_tree *et,
  72                                        struct inode *inode,
  73                                        struct buffer_head *bh);
  74 struct ocfs2_xattr_value_buf;
  75 void ocfs2_init_xattr_value_extent_tree(struct ocfs2_extent_tree *et,
  76                                         struct inode *inode,
  77                                         struct ocfs2_xattr_value_buf *vb);
  78
  79 /*
  80  * Read an extent block into *bh.  If *bh is NULL, a bh will be
  81  * allocated.  This is a cached read.  The extent block will be validated
  82  * with ocfs2_validate_extent_block().
  83  */
  84 int ocfs2_read_extent_block(struct inode *inode, u64 eb_blkno,
  85                             struct buffer_head **bh);
  86
  87 struct ocfs2_alloc_context;
  88 int ocfs2_insert_extent(struct ocfs2_super *osb,
  89                         handle_t *handle,
  90                         struct inode *inode,
  91                         struct ocfs2_extent_tree *et,
  92                         u32 cpos,
  93                         u64 start_blk,
  94                         u32 new_clusters,
  95                         u8 flags,
  96                         struct ocfs2_alloc_context *meta_ac);
  97
  98 enum ocfs2_alloc_restarted {
  99         RESTART_NONE = 0,
 100         RESTART_TRANS,
 101         RESTART_META
 102 };
 103 int ocfs2_add_clusters_in_btree(struct ocfs2_super *osb,
 104                                 struct inode *inode,
 105                                 u32 *logical_offset,
 106                                 u32 clusters_to_add,
 107                                 int mark_unwritten,
 108                                 struct ocfs2_extent_tree *et,
 109                                 handle_t *handle,
 110                                 struct ocfs2_alloc_context *data_ac,
 111                                 struct ocfs2_alloc_context *meta_ac,
 112                                 enum ocfs2_alloc_restarted *reason_ret);
 113 struct ocfs2_cached_dealloc_ctxt;
 114 int ocfs2_mark_extent_written(struct inode *inode,
 115                               struct ocfs2_extent_tree *et,
 116                               handle_t *handle, u32 cpos, u32 len, u32 phys,
 117                               struct ocfs2_alloc_context *meta_ac,
 118                               struct ocfs2_cached_dealloc_ctxt *dealloc);
 119 int ocfs2_remove_extent(struct inode *inode,
 120                         struct ocfs2_extent_tree *et,
 121                         u32 cpos, u32 len, handle_t *handle,
 122                         struct ocfs2_alloc_context *meta_ac,
 123                         struct ocfs2_cached_dealloc_ctxt *dealloc);
 124 int ocfs2_remove_btree_range(struct inode *inode,
 125                              struct ocfs2_extent_tree *et,
 126                              u32 cpos, u32 phys_cpos, u32 len,
 127                              struct ocfs2_cached_dealloc_ctxt *dealloc);
 128
 129 int ocfs2_num_free_extents(struct ocfs2_super *osb,
 130                            struct inode *inode,
 131                            struct ocfs2_extent_tree *et);
 132
 133 /*
 134  * how many new metadata chunks would an allocation need at maximum?
 135  *
 136  * Please note that the caller must make sure that root_el is the root
 137  * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
 138  * the result may be wrong.
 139  */
 140 static inline int ocfs2_extend_meta_needed(struct ocfs2_extent_list *root_el)
 141 {
 142         /*
 143          * Rather than do all the work of determining how much we need
 144          * (involves a ton of reads and locks), just ask for the
 145          * maximal limit.  That's a tree depth shift.  So, one block for
 146          * level of the tree (current l_tree_depth), one block for the
 147          * new tree_depth==0 extent_block, and one block at the new
 148          * top-of-the tree.
 149          */
 150         return le16_to_cpu(root_el->l_tree_depth) + 2;
 151 }
 152
 153 void ocfs2_dinode_new_extent_list(struct inode *inode, struct ocfs2_dinode *di);
 154 void ocfs2_set_inode_data_inline(struct inode *inode, struct ocfs2_dinode *di);
 155 int ocfs2_convert_inline_data_to_extents(struct inode *inode,
 156                                          struct buffer_head *di_bh);
 157
 158 int ocfs2_truncate_log_init(struct ocfs2_super *osb);
 159 void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb);
 160 void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
 161                                        int cancel);
 162 int ocfs2_flush_truncate_log(struct ocfs2_super *osb);
 163 int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
 164                                       int slot_num,
 165                                       struct ocfs2_dinode **tl_copy);
 166 int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
 167                                          struct ocfs2_dinode *tl_copy);
 168 int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb);
 169 int ocfs2_truncate_log_append(struct ocfs2_super *osb,
 170                               handle_t *handle,
 171                               u64 start_blk,
 172                               unsigned int num_clusters);
 173 int __ocfs2_flush_truncate_log(struct ocfs2_super *osb);
 174
 175 /*
 176  * Process local structure which describes the block unlinks done
 177  * during an operation. This is populated via
 178  * ocfs2_cache_block_dealloc().
 179  *
 180  * ocfs2_run_deallocs() should be called after the potentially
 181  * de-allocating routines. No journal handles should be open, and most
 182  * locks should have been dropped.
 183  */
 184 struct ocfs2_cached_dealloc_ctxt {
 185         struct ocfs2_per_slot_free_list         *c_first_suballocator;
 186         struct ocfs2_cached_block_free          *c_global_allocator;
 187 };
 188 static inline void ocfs2_init_dealloc_ctxt(struct ocfs2_cached_dealloc_ctxt *c)
 189 {
 190         c->c_first_suballocator = NULL;
 191         c->c_global_allocator = NULL;
 192 }
 193 int ocfs2_cache_cluster_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
 194                                 u64 blkno, unsigned int bit);
 195 static inline int ocfs2_dealloc_has_cluster(struct ocfs2_cached_dealloc_ctxt *c)
 196 {
 197         return c->c_global_allocator != NULL;
 198 }
 199 int ocfs2_run_deallocs(struct ocfs2_super *osb,
 200                        struct ocfs2_cached_dealloc_ctxt *ctxt);
 201
 202 struct ocfs2_truncate_context {
 203         struct ocfs2_cached_dealloc_ctxt tc_dealloc;
 204         int tc_ext_alloc_locked; /* is it cluster locked? */
 205         /* these get destroyed once it's passed to ocfs2_commit_truncate. */
 206         struct buffer_head *tc_last_eb_bh;
 207 };
 208
 209 int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
 210                                   u64 range_start, u64 range_end);
 211 int ocfs2_prepare_truncate(struct ocfs2_super *osb,
 212                            struct inode *inode,
 213                            struct buffer_head *fe_bh,
 214                            struct ocfs2_truncate_context **tc);
 215 int ocfs2_commit_truncate(struct ocfs2_super *osb,
 216                           struct inode *inode,
 217                           struct buffer_head *fe_bh,
 218                           struct ocfs2_truncate_context *tc);
 219 int ocfs2_truncate_inline(struct inode *inode, struct buffer_head *di_bh,
 220                           unsigned int start, unsigned int end, int trunc);
 221
 222 int ocfs2_find_leaf(struct inode *inode, struct ocfs2_extent_list *root_el,
 223                     u32 cpos, struct buffer_head **leaf_bh);
 224 int ocfs2_search_extent_list(struct ocfs2_extent_list *el, u32 v_cluster);
 225
 226 /*
 227  * Helper function to look at the # of clusters in an extent record.
 228  */
 229 static inline unsigned int ocfs2_rec_clusters(struct ocfs2_extent_list *el,
 230                                               struct ocfs2_extent_rec *rec)
 231 {
 232         /*
 233          * Cluster count in extent records is slightly different
 234          * between interior nodes and leaf nodes. This is to support
 235          * unwritten extents which need a flags field in leaf node
 236          * records, thus shrinking the available space for a clusters
 237          * field.
 238          */
 239         if (el->l_tree_depth)
 240                 return le32_to_cpu(rec->e_int_clusters);
 241         else
 242                 return le16_to_cpu(rec->e_leaf_clusters);
 243 }
 244
 245 /*
 246  * This is only valid for leaf nodes, which are the only ones that can
 247  * have empty extents anyway.
 248  */
 249 static inline int ocfs2_is_empty_extent(struct ocfs2_extent_rec *rec)
 250 {
 251         return !rec->e_leaf_clusters;
 252 }
 253
 254 #endif /* OCFS2_ALLOC_H */