fs/ocfs2/suballoc.h

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * suballoc.h
   5  *
   6  * Defines sub allocator api
   7  *
   8  * Copyright (C) 2003, 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 _CHAINALLOC_H_
  27 #define _CHAINALLOC_H_
  28
  29 typedef int (group_search_t)(struct inode *,
  30                              struct buffer_head *,
  31                              u32,                       /* bits_wanted */
  32                              u32,                       /* min_bits */
  33                              u64,                       /* max_block */
  34                              u16 *,                     /* *bit_off */
  35                              u16 *);                    /* *bits_found */
  36
  37 struct ocfs2_alloc_context {
  38         struct inode *ac_inode;    /* which bitmap are we allocating from? */
  39         struct buffer_head *ac_bh; /* file entry bh */
  40         u32    ac_alloc_slot;   /* which slot are we allocating from? */
  41         u32    ac_bits_wanted;
  42         u32    ac_bits_given;
  43 #define OCFS2_AC_USE_LOCAL 1
  44 #define OCFS2_AC_USE_MAIN  2
  45 #define OCFS2_AC_USE_INODE 3
  46 #define OCFS2_AC_USE_META  4
  47         u32    ac_which;
  48
  49         /* these are used by the chain search */
  50         u16    ac_chain;
  51         int    ac_allow_chain_relink;
  52         group_search_t *ac_group_search;
  53
  54         u64    ac_last_group;
  55         u64    ac_max_block;  /* Highest block number to allocate. 0 is
  56                                  is the same as ~0 - unlimited */
  57 };
  58
  59 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac);
  60 static inline int ocfs2_alloc_context_bits_left(struct ocfs2_alloc_context *ac)
  61 {
  62         return ac->ac_bits_wanted - ac->ac_bits_given;
  63 }
  64
  65 /*
  66  * Please note that the caller must make sure that root_el is the root
  67  * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
  68  * the result may be wrong.
  69  */
  70 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
  71                                struct ocfs2_extent_list *root_el,
  72                                struct ocfs2_alloc_context **ac);
  73 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
  74                                       int blocks,
  75                                       struct ocfs2_alloc_context **ac);
  76 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
  77                             struct ocfs2_alloc_context **ac);
  78 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
  79                            u32 bits_wanted,
  80                            struct ocfs2_alloc_context **ac);
  81
  82 int ocfs2_claim_metadata(struct ocfs2_super *osb,
  83                          handle_t *handle,
  84                          struct ocfs2_alloc_context *ac,
  85                          u32 bits_wanted,
  86                          u16 *suballoc_bit_start,
  87                          u32 *num_bits,
  88                          u64 *blkno_start);
  89 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
  90                           handle_t *handle,
  91                           struct ocfs2_alloc_context *ac,
  92                           u16 *suballoc_bit,
  93                           u64 *fe_blkno);
  94 int ocfs2_claim_clusters(struct ocfs2_super *osb,
  95                          handle_t *handle,
  96                          struct ocfs2_alloc_context *ac,
  97                          u32 min_clusters,
  98                          u32 *cluster_start,
  99                          u32 *num_clusters);
 100 /*
 101  * Use this variant of ocfs2_claim_clusters to specify a maxiumum
 102  * number of clusters smaller than the allocation reserved.
 103  */
 104 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
 105                            handle_t *handle,
 106                            struct ocfs2_alloc_context *ac,
 107                            u32 min_clusters,
 108                            u32 max_clusters,
 109                            u32 *cluster_start,
 110                            u32 *num_clusters);
 111
 112 int ocfs2_free_suballoc_bits(handle_t *handle,
 113                              struct inode *alloc_inode,
 114                              struct buffer_head *alloc_bh,
 115                              unsigned int start_bit,
 116                              u64 bg_blkno,
 117                              unsigned int count);
 118 int ocfs2_free_dinode(handle_t *handle,
 119                       struct inode *inode_alloc_inode,
 120                       struct buffer_head *inode_alloc_bh,
 121                       struct ocfs2_dinode *di);
 122 int ocfs2_free_clusters(handle_t *handle,
 123                         struct inode *bitmap_inode,
 124                         struct buffer_head *bitmap_bh,
 125                         u64 start_blk,
 126                         unsigned int num_clusters);
 127
 128 static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
 129 {
 130         u64 group = block - (u64) bit;
 131
 132         return group;
 133 }
 134
 135 static inline u32 ocfs2_cluster_from_desc(struct ocfs2_super *osb,
 136                                           u64 bg_blkno)
 137 {
 138         /* This should work for all block group descriptors as only
 139          * the 1st group descriptor of the cluster bitmap is
 140          * different. */
 141
 142         if (bg_blkno == osb->first_cluster_group_blkno)
 143                 return 0;
 144
 145         /* the rest of the block groups are located at the beginning
 146          * of their 1st cluster, so a direct translation just
 147          * works. */
 148         return ocfs2_blocks_to_clusters(osb->sb, bg_blkno);
 149 }
 150
 151 static inline int ocfs2_is_cluster_bitmap(struct inode *inode)
 152 {
 153         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 154         return osb->bitmap_blkno == OCFS2_I(inode)->ip_blkno;
 155 }
 156
 157 /* This is for local alloc ONLY. Others should use the task-specific
 158  * apis above. */
 159 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 160                                       struct ocfs2_alloc_context *ac);
 161 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac);
 162
 163 /* given a cluster offset, calculate which block group it belongs to
 164  * and return that block offset. */
 165 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster);
 166
 167 /* somewhat more expensive than our other checks, so use sparingly. */
 168 int ocfs2_check_group_descriptor(struct super_block *sb,
 169                                  struct ocfs2_dinode *di,
 170                                  struct ocfs2_group_desc *gd);
 171 int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_extent_tree *et,
 172                           u32 clusters_to_add, u32 extents_to_split,
 173                           struct ocfs2_alloc_context **data_ac,
 174                           struct ocfs2_alloc_context **meta_ac);
 175 #endif /* _CHAINALLOC_H_ */