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root/fs/ocfs2/suballoc.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. ocfs2_alloc_context_bits_left
  2. ocfs2_which_suballoc_group
  3. ocfs2_cluster_from_desc
  4. ocfs2_is_cluster_bitmap

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * suballoc.h
 *
 * Defines sub allocator api
 *
 * Copyright (C) 2003, 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#ifndef _CHAINALLOC_H_
#define _CHAINALLOC_H_

typedef int (group_search_t)(struct inode *,
                             struct buffer_head *,
                             u32,                       /* bits_wanted */
                             u32,                       /* min_bits */
                             u64,                       /* max_block */
                             u16 *,                     /* *bit_off */
                             u16 *);                    /* *bits_found */

struct ocfs2_alloc_context {
        struct inode *ac_inode;    /* which bitmap are we allocating from? */
        struct buffer_head *ac_bh; /* file entry bh */
        u32    ac_alloc_slot;   /* which slot are we allocating from? */
        u32    ac_bits_wanted;
        u32    ac_bits_given;
#define OCFS2_AC_USE_LOCAL 1
#define OCFS2_AC_USE_MAIN  2
#define OCFS2_AC_USE_INODE 3
#define OCFS2_AC_USE_META  4
        u32    ac_which;

        /* these are used by the chain search */
        u16    ac_chain;
        int    ac_allow_chain_relink;
        group_search_t *ac_group_search;

        u64    ac_last_group;
        u64    ac_max_block;  /* Highest block number to allocate. 0 is
                                 is the same as ~0 - unlimited */
};

void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac);
static inline int ocfs2_alloc_context_bits_left(struct ocfs2_alloc_context *ac)
{
        return ac->ac_bits_wanted - ac->ac_bits_given;
}

/*
 * Please note that the caller must make sure that root_el is the root
 * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
 * the result may be wrong.
 */
int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
                               struct ocfs2_extent_list *root_el,
                               struct ocfs2_alloc_context **ac);
int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
                                      int blocks,
                                      struct ocfs2_alloc_context **ac);
int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
                            struct ocfs2_alloc_context **ac);
int ocfs2_reserve_clusters(struct ocfs2_super *osb,
                           u32 bits_wanted,
                           struct ocfs2_alloc_context **ac);

int ocfs2_claim_metadata(struct ocfs2_super *osb,
                         handle_t *handle,
                         struct ocfs2_alloc_context *ac,
                         u32 bits_wanted,
                         u16 *suballoc_bit_start,
                         u32 *num_bits,
                         u64 *blkno_start);
int ocfs2_claim_new_inode(struct ocfs2_super *osb,
                          handle_t *handle,
                          struct ocfs2_alloc_context *ac,
                          u16 *suballoc_bit,
                          u64 *fe_blkno);
int ocfs2_claim_clusters(struct ocfs2_super *osb,
                         handle_t *handle,
                         struct ocfs2_alloc_context *ac,
                         u32 min_clusters,
                         u32 *cluster_start,
                         u32 *num_clusters);
/*
 * Use this variant of ocfs2_claim_clusters to specify a maxiumum
 * number of clusters smaller than the allocation reserved.
 */
int __ocfs2_claim_clusters(struct ocfs2_super *osb,
                           handle_t *handle,
                           struct ocfs2_alloc_context *ac,
                           u32 min_clusters,
                           u32 max_clusters,
                           u32 *cluster_start,
                           u32 *num_clusters);

int ocfs2_free_suballoc_bits(handle_t *handle,
                             struct inode *alloc_inode,
                             struct buffer_head *alloc_bh,
                             unsigned int start_bit,
                             u64 bg_blkno,
                             unsigned int count);
int ocfs2_free_dinode(handle_t *handle,
                      struct inode *inode_alloc_inode,
                      struct buffer_head *inode_alloc_bh,
                      struct ocfs2_dinode *di);
int ocfs2_free_clusters(handle_t *handle,
                        struct inode *bitmap_inode,
                        struct buffer_head *bitmap_bh,
                        u64 start_blk,
                        unsigned int num_clusters);

static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
{
        u64 group = block - (u64) bit;

        return group;
}

static inline u32 ocfs2_cluster_from_desc(struct ocfs2_super *osb,
                                          u64 bg_blkno)
{
        /* This should work for all block group descriptors as only
         * the 1st group descriptor of the cluster bitmap is
         * different. */

        if (bg_blkno == osb->first_cluster_group_blkno)
                return 0;

        /* the rest of the block groups are located at the beginning
         * of their 1st cluster, so a direct translation just
         * works. */
        return ocfs2_blocks_to_clusters(osb->sb, bg_blkno);
}

static inline int ocfs2_is_cluster_bitmap(struct inode *inode)
{
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
        return osb->bitmap_blkno == OCFS2_I(inode)->ip_blkno;
}

/* This is for local alloc ONLY. Others should use the task-specific
 * apis above. */
int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
                                      struct ocfs2_alloc_context *ac);
void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac);

/* given a cluster offset, calculate which block group it belongs to
 * and return that block offset. */
u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster);

/* somewhat more expensive than our other checks, so use sparingly. */
int ocfs2_check_group_descriptor(struct super_block *sb,
                                 struct ocfs2_dinode *di,
                                 struct ocfs2_group_desc *gd);
int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_extent_tree *et,
                          u32 clusters_to_add, u32 extents_to_split,
                          struct ocfs2_alloc_context **data_ac,
                          struct ocfs2_alloc_context **meta_ac);
#endif /* _CHAINALLOC_H_ */

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