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_init_steal_slots(struct ocfs2_super *osb);
  60 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac);
  61 static inline int ocfs2_alloc_context_bits_left(struct ocfs2_alloc_context *ac)
  62 {
  63         return ac->ac_bits_wanted - ac->ac_bits_given;
  64 }
  65
  66 /*
  67  * Please note that the caller must make sure that root_el is the root
  68  * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
  69  * the result may be wrong.
  70  */
  71 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
  72                                struct ocfs2_extent_list *root_el,
  73                                struct ocfs2_alloc_context **ac);
  74 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
  75                                       int blocks,
  76                                       struct ocfs2_alloc_context **ac);
  77 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
  78                             struct ocfs2_alloc_context **ac);
  79 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
  80                            u32 bits_wanted,
  81                            struct ocfs2_alloc_context **ac);
  82
  83 int ocfs2_claim_metadata(struct ocfs2_super *osb,
  84                          handle_t *handle,
  85                          struct ocfs2_alloc_context *ac,
  86                          u32 bits_wanted,
  87                          u16 *suballoc_bit_start,
  88                          u32 *num_bits,
  89                          u64 *blkno_start);
  90 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
  91                           handle_t *handle,
  92                           struct inode *dir,
  93                           struct buffer_head *parent_fe_bh,
  94                           struct ocfs2_alloc_context *ac,
  95                           u16 *suballoc_bit,
  96                           u64 *fe_blkno);
  97 int ocfs2_claim_clusters(struct ocfs2_super *osb,
  98                          handle_t *handle,
  99                          struct ocfs2_alloc_context *ac,
 100                          u32 min_clusters,
 101                          u32 *cluster_start,
 102                          u32 *num_clusters);
 103 /*
 104  * Use this variant of ocfs2_claim_clusters to specify a maxiumum
 105  * number of clusters smaller than the allocation reserved.
 106  */
 107 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
 108                            handle_t *handle,
 109                            struct ocfs2_alloc_context *ac,
 110                            u32 min_clusters,
 111                            u32 max_clusters,
 112                            u32 *cluster_start,
 113                            u32 *num_clusters);
 114
 115 int ocfs2_free_suballoc_bits(handle_t *handle,
 116                              struct inode *alloc_inode,
 117                              struct buffer_head *alloc_bh,
 118                              unsigned int start_bit,
 119                              u64 bg_blkno,
 120                              unsigned int count);
 121 int ocfs2_free_dinode(handle_t *handle,
 122                       struct inode *inode_alloc_inode,
 123                       struct buffer_head *inode_alloc_bh,
 124                       struct ocfs2_dinode *di);
 125 int ocfs2_free_clusters(handle_t *handle,
 126                         struct inode *bitmap_inode,
 127                         struct buffer_head *bitmap_bh,
 128                         u64 start_blk,
 129                         unsigned int num_clusters);
 130 int ocfs2_release_clusters(handle_t *handle,
 131                            struct inode *bitmap_inode,
 132                            struct buffer_head *bitmap_bh,
 133                            u64 start_blk,
 134                            unsigned int num_clusters);
 135
 136 static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
 137 {
 138         u64 group = block - (u64) bit;
 139
 140         return group;
 141 }
 142
 143 static inline u32 ocfs2_cluster_from_desc(struct ocfs2_super *osb,
 144                                           u64 bg_blkno)
 145 {
 146         /* This should work for all block group descriptors as only
 147          * the 1st group descriptor of the cluster bitmap is
 148          * different. */
 149
 150         if (bg_blkno == osb->first_cluster_group_blkno)
 151                 return 0;
 152
 153         /* the rest of the block groups are located at the beginning
 154          * of their 1st cluster, so a direct translation just
 155          * works. */
 156         return ocfs2_blocks_to_clusters(osb->sb, bg_blkno);
 157 }
 158
 159 static inline int ocfs2_is_cluster_bitmap(struct inode *inode)
 160 {
 161         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 162         return osb->bitmap_blkno == OCFS2_I(inode)->ip_blkno;
 163 }
 164
 165 /* This is for local alloc ONLY. Others should use the task-specific
 166  * apis above. */
 167 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 168                                       struct ocfs2_alloc_context *ac);
 169 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac);
 170
 171 /* given a cluster offset, calculate which block group it belongs to
 172  * and return that block offset. */
 173 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster);
 174
 175 /*
 176  * By default, ocfs2_read_group_descriptor() calls ocfs2_error() when it
 177  * finds a problem.  A caller that wants to check a group descriptor
 178  * without going readonly should read the block with ocfs2_read_block[s]()
 179  * and then checking it with this function.  This is only resize, really.
 180  * Everyone else should be using ocfs2_read_group_descriptor().
 181  */
 182 int ocfs2_check_group_descriptor(struct super_block *sb,
 183                                  struct ocfs2_dinode *di,
 184                                  struct buffer_head *bh);
 185 /*
 186  * Read a group descriptor block into *bh.  If *bh is NULL, a bh will be
 187  * allocated.  This is a cached read.  The descriptor will be validated with
 188  * ocfs2_validate_group_descriptor().
 189  */
 190 int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 191                                 u64 gd_blkno, struct buffer_head **bh);
 192
 193 int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_extent_tree *et,
 194                           u32 clusters_to_add, u32 extents_to_split,
 195                           struct ocfs2_alloc_context **data_ac,
 196                           struct ocfs2_alloc_context **meta_ac);
 197
 198 int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res);
 199 #endif /* _CHAINALLOC_H_ */