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