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- /*
- * Copyright (c) 2003-2006, 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_EXT4_EXTENTS
- #define _LINUX_EXT4_EXTENTS
- #include <linux/ext4_fs.h>
- /*
- * 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_
- /*
- * with EXTENTS_STATS defined number of blocks and extents
- * are collected in truncate path. they'll be showed at
- * umount time
- */
- #define EXTENTS_STATS__
- /*
- * 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(a...) printk(a)
- #else
- #define ext_debug(a...)
- #endif
- /*
- * if EXT_STATS is defined then stats numbers are collected
- * these number will be displayed at umount time
- */
- #define EXT_STATS_
- /*
- * ext4_inode has i_block array (60 bytes total)
- * first 12 bytes store ext4_extent_header
- * the remain stores array of ext4_extent
- */
- /*
- * this is extent on-disk structure
- * it's used at the bottom of the tree
- */
- struct ext4_extent {
- __le32 ee_block; /* first logical block extent covers */
- __le16 ee_len; /* number of blocks covered by extent */
- __le16 ee_start_hi; /* high 16 bits of physical block */
- __le32 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 ext4_extent_idx {
- __le32 ei_block; /* index covers logical blocks from 'block' */
- __le32 ei_leaf; /* pointer to the physical block of the next *
- * level. leaf or next index could bet here */
- __le16 ei_leaf_hi; /* high 16 bits of physical block */
- __u16 ei_unused;
- };
- /*
- * each block (leaves and indexes), even inode-stored has header
- */
- struct ext4_extent_header {
- __le16 eh_magic; /* probably will support different formats */
- __le16 eh_entries; /* number of valid entries */
- __le16 eh_max; /* capacity of store in entries */
- __le16 eh_depth; /* has tree real underlaying blocks? */
- __le32 eh_generation; /* generation of the tree */
- };
- #define EXT4_EXT_MAGIC cpu_to_le16(0xf30a)
- /*
- * array of ext4_ext_path contains path to some extent
- * creation/lookup routines use it for traversal/splitting/etc
- * truncate uses it to simulate recursive walking
- */
- struct ext4_ext_path {
- ext4_fsblk_t p_block;
- __u16 p_depth;
- struct ext4_extent *p_ext;
- struct ext4_extent_idx *p_idx;
- struct ext4_extent_header *p_hdr;
- struct buffer_head *p_bh;
- };
- /*
- * structure for external API
- */
- #define EXT4_EXT_CACHE_NO 0
- #define EXT4_EXT_CACHE_GAP 1
- #define EXT4_EXT_CACHE_EXTENT 2
- /*
- * to be called by ext4_ext_walk_space()
- * negative retcode - error
- * positive retcode - signal for ext4_ext_walk_space(), see below
- * callback must return valid extent (passed or newly created)
- */
- typedef int (*ext_prepare_callback)(struct inode *, struct ext4_ext_path *,
- struct ext4_ext_cache *,
- void *);
- #define EXT_CONTINUE 0
- #define EXT_BREAK 1
- #define EXT_REPEAT 2
- #define EXT_MAX_BLOCK 0xffffffff
- #define EXT_FIRST_EXTENT(__hdr__) \
- ((struct ext4_extent *) (((char *) (__hdr__)) + \
- sizeof(struct ext4_extent_header)))
- #define EXT_FIRST_INDEX(__hdr__) \
- ((struct ext4_extent_idx *) (((char *) (__hdr__)) + \
- sizeof(struct ext4_extent_header)))
- #define EXT_HAS_FREE_INDEX(__path__) \
- (le16_to_cpu((__path__)->p_hdr->eh_entries) \
- < le16_to_cpu((__path__)->p_hdr->eh_max))
- #define EXT_LAST_EXTENT(__hdr__) \
- (EXT_FIRST_EXTENT((__hdr__)) + le16_to_cpu((__hdr__)->eh_entries) - 1)
- #define EXT_LAST_INDEX(__hdr__) \
- (EXT_FIRST_INDEX((__hdr__)) + le16_to_cpu((__hdr__)->eh_entries) - 1)
- #define EXT_MAX_EXTENT(__hdr__) \
- (EXT_FIRST_EXTENT((__hdr__)) + le16_to_cpu((__hdr__)->eh_max) - 1)
- #define EXT_MAX_INDEX(__hdr__) \
- (EXT_FIRST_INDEX((__hdr__)) + le16_to_cpu((__hdr__)->eh_max) - 1)
- static inline struct ext4_extent_header *ext_inode_hdr(struct inode *inode)
- {
- return (struct ext4_extent_header *) EXT4_I(inode)->i_data;
- }
- static inline struct ext4_extent_header *ext_block_hdr(struct buffer_head *bh)
- {
- return (struct ext4_extent_header *) bh->b_data;
- }
- static inline unsigned short ext_depth(struct inode *inode)
- {
- return le16_to_cpu(ext_inode_hdr(inode)->eh_depth);
- }
- static inline void ext4_ext_tree_changed(struct inode *inode)
- {
- EXT4_I(inode)->i_ext_generation++;
- }
- static inline void
- ext4_ext_invalidate_cache(struct inode *inode)
- {
- EXT4_I(inode)->i_cached_extent.ec_type = EXT4_EXT_CACHE_NO;
- }
- extern int ext4_extent_tree_init(handle_t *, struct inode *);
- extern int ext4_ext_calc_credits_for_insert(struct inode *, struct ext4_ext_path *);
- extern int ext4_ext_insert_extent(handle_t *, struct inode *, struct ext4_ext_path *, struct ext4_extent *);
- extern int ext4_ext_walk_space(struct inode *, unsigned long, unsigned long, ext_prepare_callback, void *);
- extern struct ext4_ext_path * ext4_ext_find_extent(struct inode *, int, struct ext4_ext_path *);
- #endif /* _LINUX_EXT4_EXTENTS */
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