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