/*
* Copyright (c) 2003,2004 Cluster File Systems, Inc, info@clusterfs.com
* Written by Alex Tomas <alex@clusterfs.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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 Licens
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
*/
#ifndef _LINUX_EXT3_EXTENTS
#define _LINUX_EXT3_EXTENTS
/*
* with AGRESSIVE_TEST defined capacity of index/leaf blocks
* become very little, so index split, in-depth growing and
* other hard changes happens much more often
* this is for debug purposes only
*/
#define AGRESSIVE_TEST_
/*
* if CHECK_BINSEARCH defined, then results of binary search
* will be checked by linear search
*/
#define CHECK_BINSEARCH_
/*
* if EXT_DEBUG is defined you can use 'extdebug' mount option
* to get lots of info what's going on
*/
//#define EXT_DEBUG
#ifdef EXT_DEBUG
#define ext_debug(tree,fmt,a...) \
do { \
if (test_opt((tree)->inode->i_sb, EXTDEBUG)) \
printk(fmt, ##a); \
} while (0);
#else
#define ext_debug(tree,fmt,a...)
#endif
/*
* if EXT_STATS is defined then stats numbers are collected
* these number will be displayed at umount time
*/
#define EXT_STATS_
#define EXT3_ALLOC_NEEDED 3 /* block bitmap + group desc. + sb */
/*
* ext3_inode has i_block array (total 60 bytes)
* first 4 bytes are used to store:
* - tree depth (0 mean there is no tree yet. all extents in the inode)
* - number of alive extents in the inode
*/
/*
* this is extent on-disk structure
* it's used at the bottom of the tree
*/
struct ext3_extent {
__u32 ee_block; /* first logical block extent covers */
__u16 ee_len; /* number of blocks covered by extent */
__u16 ee_start_hi; /* high 16 bits of physical block */
__u32 ee_start; /* low 32 bigs of physical block */
};
/*
* this is index on-disk structure
* it's used at all the levels, but the bottom
*/
struct ext3_extent_idx {
__u32 ei_block; /* index covers logical blocks from 'block' */
__u32 ei_leaf; /* pointer to the physical block of the next *
* level. leaf or next index could bet here */
__u16 ei_leaf_hi; /* high 16 bits of physical block */
__u16 ei_unused;
};
/*
* each block (leaves and indexes), even inode-stored has header
*/
struct ext3_extent_header {
__u16 eh_magic; /* probably will support different formats */
__u16 eh_entries; /* number of valid entries */
__u16 eh_max; /* capacity of store in entries */
__u16 eh_depth; /* has tree real underlaying blocks? */
__u32 eh_generation; /* generation of the tree */
};
#define EXT3_EXT_MAGIC 0xf30a
/*
* array of ext3_ext_path contains path to some extent
* creation/lookup routines use it for traversal/splitting/etc
* truncate uses it to simulate recursive walking
*/
struct ext3_ext_path {
__u32 p_block;
__u16 p_depth;
struct ext3_extent *p_ext;
struct ext3_extent_idx *p_idx;
struct ext3_extent_header *p_hdr;
struct buffer_head *p_bh;
};
/*
* structure for external API
*/
#define EXT_CONTINUE 0
#define EXT_BREAK 1
#define EXT_REPEAT 2
#define EXT_MAX_BLOCK 0xffffffff
#define EXT_CACHE_MARK 0xffff
#define EXT_FIRST_EXTENT(__hdr__) \
((struct ext3_extent *) (((char *) (__hdr__)) + \
sizeof(struct ext3_extent_header)))
#define EXT_FIRST_INDEX(__hdr__) \
((struct ext3_extent_idx *) (((char *) (__hdr__)) + \
sizeof(struct ext3_extent_header)))
#define EXT_HAS_FREE_INDEX(__path__) \
((__path__)->p_hdr->eh_entries < (__path__)->p_hdr->eh_max)
#define EXT_LAST_EXTENT(__hdr__) \
(EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->eh_entries - 1)
#define EXT_LAST_INDEX(__hdr__) \
(EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->eh_entries - 1)
#define EXT_MAX_EXTENT(__hdr__) \
(EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->eh_max - 1)
#define EXT_MAX_INDEX(__hdr__) \
(EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->eh_max - 1)
#define EXT_ROOT_HDR(tree) \
((struct ext3_extent_header *) (tree)->root)
#define EXT_BLOCK_HDR(bh) \
((struct ext3_extent_header *) (bh)->b_data)
#define EXT_DEPTH(_t_) \
(((struct ext3_extent_header *)((_t_)->root))->eh_depth)
#define EXT_GENERATION(_t_) \
(((struct ext3_extent_header *)((_t_)->root))->eh_generation)
#define EXT_ASSERT(__x__) if (!(__x__)) BUG();
/*
* this structure is used to gather extents from the tree via ioctl
*/
struct ext3_extent_buf {
unsigned long start;
int buflen;
void *buffer;
void *cur;
int err;
};
/*
* this structure is used to collect stats info about the tree
*/
struct ext3_extent_tree_stats {
int depth;
int extents_num;
int leaf_num;
};
#ifdef __KERNEL__
/*
* ext3_extents_tree is used to pass initial information
* to top-level extents API
*/
struct ext3_extents_helpers;
struct ext3_extents_tree {
struct inode *inode; /* inode which tree belongs to */
void *root; /* ptr to data top of tree resides at */
void *buffer; /* will be passed as arg to ^^ routines */
int buffer_len;
void *private;
struct ext3_extent *cex;/* last found extent */
struct ext3_extents_helpers *ops;
};
struct ext3_extents_helpers {
int (*get_write_access)(handle_t *h, void *buffer);
int (*mark_buffer_dirty)(handle_t *h, void *buffer);
int (*mergable)(struct ext3_extent *ex1, struct ext3_extent *ex2);
int (*remove_extent_credits)(struct ext3_extents_tree *,
struct ext3_extent *, unsigned long,
unsigned long);
int (*remove_extent)(struct ext3_extents_tree *,
struct ext3_extent *, unsigned long,
unsigned long);
int (*new_block)(handle_t *, struct ext3_extents_tree *,
struct ext3_ext_path *, struct ext3_extent *,
int *);
};
/*
* to be called by ext3_ext_walk_space()
* negative retcode - error
* positive retcode - signal for ext3_ext_walk_space(), see below
* callback must return valid extent (passed or newly created)
*/
typedef int (*ext_prepare_callback)(struct ext3_extents_tree *,
struct ext3_ext_path *,
struct ext3_extent *, int);
void ext3_init_tree_desc(struct ext3_extents_tree *, struct inode *);
extern int ext3_extent_tree_init(handle_t *, struct ext3_extents_tree *);
extern int ext3_ext_calc_credits_for_insert(struct ext3_extents_tree *, struct ext3_ext_path *);
extern int ext3_ext_insert_extent(handle_t *, struct ext3_extents_tree *, struct ext3_ext_path *, struct ext3_extent *);
extern int ext3_ext_walk_space(struct ext3_extents_tree *, unsigned long, unsigned long, ext_prepare_callback);
extern int ext3_ext_remove_space(struct ext3_extents_tree *, unsigned long, unsigned long);
extern struct ext3_ext_path * ext3_ext_find_extent(struct ext3_extents_tree *, int, struct ext3_ext_path *);
static inline void
ext3_ext_invalidate_cache(struct ext3_extents_tree *tree)
{
if (tree->cex)
tree->cex->ee_len = 0;
}
#endif /* __KERNEL__ */
#endif /* _LINUX_EXT3_EXTENTS */