linux/fs/ocfs2/alloc.h
Mark Fasheh e48edee2d8 ocfs2: make room for unwritten extents flag
Due to the size of our group bitmaps, we'll never have a leaf node extent
record with more than 16 bits worth of clusters. Split e_clusters up so that
leaf nodes can get a flags field where we can mark unwritten extents.
Interior nodes whose length references all the child nodes beneath it can't
split their e_clusters field, so we use a union to preserve sizing there.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-04-26 15:02:37 -07:00

107 lines
3.6 KiB
C

/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* alloc.h
*
* Function prototypes
*
* Copyright (C) 2002, 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 OCFS2_ALLOC_H
#define OCFS2_ALLOC_H
struct ocfs2_alloc_context;
int ocfs2_insert_extent(struct ocfs2_super *osb,
handle_t *handle,
struct inode *inode,
struct buffer_head *fe_bh,
u32 cpos,
u64 start_blk,
u32 new_clusters,
struct ocfs2_alloc_context *meta_ac);
int ocfs2_num_free_extents(struct ocfs2_super *osb,
struct inode *inode,
struct ocfs2_dinode *fe);
/* how many new metadata chunks would an allocation need at maximum? */
static inline int ocfs2_extend_meta_needed(struct ocfs2_dinode *fe)
{
/*
* Rather than do all the work of determining how much we need
* (involves a ton of reads and locks), just ask for the
* maximal limit. That's a tree depth shift. So, one block for
* level of the tree (current l_tree_depth), one block for the
* new tree_depth==0 extent_block, and one block at the new
* top-of-the tree.
*/
return le16_to_cpu(fe->id2.i_list.l_tree_depth) + 2;
}
int ocfs2_truncate_log_init(struct ocfs2_super *osb);
void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb);
void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
int cancel);
int ocfs2_flush_truncate_log(struct ocfs2_super *osb);
int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
int slot_num,
struct ocfs2_dinode **tl_copy);
int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
struct ocfs2_dinode *tl_copy);
struct ocfs2_truncate_context {
struct inode *tc_ext_alloc_inode;
struct buffer_head *tc_ext_alloc_bh;
int tc_ext_alloc_locked; /* is it cluster locked? */
/* these get destroyed once it's passed to ocfs2_commit_truncate. */
struct buffer_head *tc_last_eb_bh;
};
int ocfs2_zero_tail_for_truncate(struct inode *inode, handle_t *handle,
u64 new_i_size);
int ocfs2_prepare_truncate(struct ocfs2_super *osb,
struct inode *inode,
struct buffer_head *fe_bh,
struct ocfs2_truncate_context **tc);
int ocfs2_commit_truncate(struct ocfs2_super *osb,
struct inode *inode,
struct buffer_head *fe_bh,
struct ocfs2_truncate_context *tc);
int ocfs2_find_leaf(struct inode *inode, struct ocfs2_extent_list *root_el,
u32 cpos, struct buffer_head **leaf_bh);
/*
* Helper function to look at the # of clusters in an extent record.
*/
static inline unsigned int ocfs2_rec_clusters(struct ocfs2_extent_list *el,
struct ocfs2_extent_rec *rec)
{
/*
* Cluster count in extent records is slightly different
* between interior nodes and leaf nodes. This is to support
* unwritten extents which need a flags field in leaf node
* records, thus shrinking the available space for a clusters
* field.
*/
if (el->l_tree_depth)
return le32_to_cpu(rec->e_int_clusters);
else
return le16_to_cpu(rec->e_leaf_clusters);
}
#endif /* OCFS2_ALLOC_H */