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.
  49  * ocfs2_extent_tree_operations abstract the normal operations we do for
  50  * the root of extent b-tree.
  51  */
  52 struct ocfs2_extent_tree_operations;
  53 struct ocfs2_extent_tree {
  54         struct ocfs2_extent_tree_operations     *et_ops;
  55         struct buffer_head                      *et_root_bh;
  56         struct ocfs2_extent_list                *et_root_el;
  57         void                                    *et_object;
  58         unsigned int                            et_max_leaf_clusters;
  59 };
  60
  61 /*
  62  * ocfs2_init_*_extent_tree() will fill an ocfs2_extent_tree from the
  63  * specified object buffer.
  64  */
  65 void ocfs2_init_dinode_extent_tree(struct ocfs2_extent_tree *et,
  66                                    struct inode *inode,
  67                                    struct buffer_head *bh);
  68 void ocfs2_init_xattr_tree_extent_tree(struct ocfs2_extent_tree *et,
  69                                        struct inode *inode,
  70                                        struct buffer_head *bh);
  71 void ocfs2_init_xattr_value_extent_tree(struct ocfs2_extent_tree *et,
  72                                         struct inode *inode,
  73                                         struct buffer_head *bh,
  74                                         struct ocfs2_xattr_value_root *xv);
  75
  76 struct ocfs2_alloc_context;
  77 int ocfs2_insert_extent(struct ocfs2_super *osb,
  78                         handle_t *handle,
  79                         struct inode *inode,
  80                         struct ocfs2_extent_tree *et,
  81                         u32 cpos,
  82                         u64 start_blk,
  83                         u32 new_clusters,
  84                         u8 flags,
  85                         struct ocfs2_alloc_context *meta_ac);
  86
  87 enum ocfs2_alloc_restarted {
  88         RESTART_NONE = 0,
  89         RESTART_TRANS,
  90         RESTART_META
  91 };
  92 int ocfs2_add_clusters_in_btree(struct ocfs2_super *osb,
  93                                 struct inode *inode,
  94                                 u32 *logical_offset,
  95                                 u32 clusters_to_add,
  96                                 int mark_unwritten,
  97                                 struct ocfs2_extent_tree *et,
  98                                 handle_t *handle,
  99                                 struct ocfs2_alloc_context *data_ac,
 100                                 struct ocfs2_alloc_context *meta_ac,
 101                                 enum ocfs2_alloc_restarted *reason_ret);
 102 struct ocfs2_cached_dealloc_ctxt;
 103 int ocfs2_mark_extent_written(struct inode *inode,
 104                               struct ocfs2_extent_tree *et,
 105                               handle_t *handle, u32 cpos, u32 len, u32 phys,
 106                               struct ocfs2_alloc_context *meta_ac,
 107                               struct ocfs2_cached_dealloc_ctxt *dealloc);
 108 int ocfs2_remove_extent(struct inode *inode,
 109                         struct ocfs2_extent_tree *et,
 110                         u32 cpos, u32 len, handle_t *handle,
 111                         struct ocfs2_alloc_context *meta_ac,
 112                         struct ocfs2_cached_dealloc_ctxt *dealloc);
 113 int ocfs2_remove_btree_range(struct inode *inode,
 114                              struct ocfs2_extent_tree *et,
 115                              u32 cpos, u32 phys_cpos, u32 len,
 116                              struct ocfs2_cached_dealloc_ctxt *dealloc);
 117
 118 int ocfs2_num_free_extents(struct ocfs2_super *osb,
 119                            struct inode *inode,
 120                            struct ocfs2_extent_tree *et);
 121
 122 /*
 123  * how many new metadata chunks would an allocation need at maximum?
 124  *
 125  * Please note that the caller must make sure that root_el is the root
 126  * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
 127  * the result may be wrong.
 128  */
 129 static inline int ocfs2_extend_meta_needed(struct ocfs2_extent_list *root_el)
 130 {
 131         /*
 132          * Rather than do all the work of determining how much we need
 133          * (involves a ton of reads and locks), just ask for the
 134          * maximal limit.  That's a tree depth shift.  So, one block for
 135          * level of the tree (current l_tree_depth), one block for the
 136          * new tree_depth==0 extent_block, and one block at the new
 137          * top-of-the tree.
 138          */
 139         return le16_to_cpu(root_el->l_tree_depth) + 2;
 140 }
 141
 142 void ocfs2_dinode_new_extent_list(struct inode *inode, struct ocfs2_dinode *di);
 143 void ocfs2_set_inode_data_inline(struct inode *inode, struct ocfs2_dinode *di);
 144 int ocfs2_convert_inline_data_to_extents(struct inode *inode,
 145                                          struct buffer_head *di_bh);
 146
 147 int ocfs2_truncate_log_init(struct ocfs2_super *osb);
 148 void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb);
 149 void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
 150                                        int cancel);
 151 int ocfs2_flush_truncate_log(struct ocfs2_super *osb);
 152 int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
 153                                       int slot_num,
 154                                       struct ocfs2_dinode **tl_copy);
 155 int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
 156                                          struct ocfs2_dinode *tl_copy);
 157 int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb);
 158 int ocfs2_truncate_log_append(struct ocfs2_super *osb,
 159                               handle_t *handle,
 160                               u64 start_blk,
 161                               unsigned int num_clusters);
 162 int __ocfs2_flush_truncate_log(struct ocfs2_super *osb);
 163
 164 /*
 165  * Process local structure which describes the block unlinks done
 166  * during an operation. This is populated via
 167  * ocfs2_cache_block_dealloc().
 168  *
 169  * ocfs2_run_deallocs() should be called after the potentially
 170  * de-allocating routines. No journal handles should be open, and most
 171  * locks should have been dropped.
 172  */
 173 struct ocfs2_cached_dealloc_ctxt {
 174         struct ocfs2_per_slot_free_list         *c_first_suballocator;
 175         struct ocfs2_cached_block_free          *c_global_allocator;
 176 };
 177 static inline void ocfs2_init_dealloc_ctxt(struct ocfs2_cached_dealloc_ctxt *c)
 178 {
 179         c->c_first_suballocator = NULL;
 180         c->c_global_allocator = NULL;
 181 }
 182 int ocfs2_cache_cluster_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
 183                                 u64 blkno, unsigned int bit);
 184 static inline int ocfs2_dealloc_has_cluster(struct ocfs2_cached_dealloc_ctxt *c)
 185 {
 186         return c->c_global_allocator != NULL;
 187 }
 188 int ocfs2_run_deallocs(struct ocfs2_super *osb,
 189                        struct ocfs2_cached_dealloc_ctxt *ctxt);
 190
 191 struct ocfs2_truncate_context {
 192         struct ocfs2_cached_dealloc_ctxt tc_dealloc;
 193         int tc_ext_alloc_locked; /* is it cluster locked? */
 194         /* these get destroyed once it's passed to ocfs2_commit_truncate. */
 195         struct buffer_head *tc_last_eb_bh;
 196 };
 197
 198 int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
 199                                   u64 range_start, u64 range_end);
 200 int ocfs2_prepare_truncate(struct ocfs2_super *osb,
 201                            struct inode *inode,
 202                            struct buffer_head *fe_bh,
 203                            struct ocfs2_truncate_context **tc);
 204 int ocfs2_commit_truncate(struct ocfs2_super *osb,
 205                           struct inode *inode,
 206                           struct buffer_head *fe_bh,
 207                           struct ocfs2_truncate_context *tc);
 208 int ocfs2_truncate_inline(struct inode *inode, struct buffer_head *di_bh,
 209                           unsigned int start, unsigned int end, int trunc);
 210
 211 int ocfs2_find_leaf(struct inode *inode, struct ocfs2_extent_list *root_el,
 212                     u32 cpos, struct buffer_head **leaf_bh);
 213 int ocfs2_search_extent_list(struct ocfs2_extent_list *el, u32 v_cluster);
 214
 215 /*
 216  * Helper function to look at the # of clusters in an extent record.
 217  */
 218 static inline unsigned int ocfs2_rec_clusters(struct ocfs2_extent_list *el,
 219                                               struct ocfs2_extent_rec *rec)
 220 {
 221         /*
 222          * Cluster count in extent records is slightly different
 223          * between interior nodes and leaf nodes. This is to support
 224          * unwritten extents which need a flags field in leaf node
 225          * records, thus shrinking the available space for a clusters
 226          * field.
 227          */
 228         if (el->l_tree_depth)
 229                 return le32_to_cpu(rec->e_int_clusters);
 230         else
 231                 return le16_to_cpu(rec->e_leaf_clusters);
 232 }
 233
 234 /*
 235  * This is only valid for leaf nodes, which are the only ones that can
 236  * have empty extents anyway.
 237  */
 238 static inline int ocfs2_is_empty_extent(struct ocfs2_extent_rec *rec)
 239 {
 240         return !rec->e_leaf_clusters;
 241 }
 242
 243 #endif /* OCFS2_ALLOC_H */