a86c618126
On disk extents format:
/*
* this is extent on-disk structure
* it's used at the bottom of the tree
*/
struct ext3_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 */
};
Signed-off-by: Alex Tomas <alex@clusterfs.com>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
197 lines
5.8 KiB
C
197 lines
5.8 KiB
C
/*
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* Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
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* Written by Alex Tomas <alex@clusterfs.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public Licens
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
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*/
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#ifndef _LINUX_EXT4_EXTENTS
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#define _LINUX_EXT4_EXTENTS
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#include <linux/ext4_fs.h>
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/*
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* with AGRESSIVE_TEST defined capacity of index/leaf blocks
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* become very little, so index split, in-depth growing and
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* other hard changes happens much more often
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* this is for debug purposes only
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*/
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#define AGRESSIVE_TEST_
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/*
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* with EXTENTS_STATS defined number of blocks and extents
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* are collected in truncate path. they'll be showed at
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* umount time
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*/
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#define EXTENTS_STATS__
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/*
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* if CHECK_BINSEARCH defined, then results of binary search
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* will be checked by linear search
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*/
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#define CHECK_BINSEARCH__
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/*
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* if EXT_DEBUG is defined you can use 'extdebug' mount option
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* to get lots of info what's going on
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*/
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#define EXT_DEBUG__
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#ifdef EXT_DEBUG
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#define ext_debug(a...) printk(a)
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#else
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#define ext_debug(a...)
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#endif
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/*
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* if EXT_STATS is defined then stats numbers are collected
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* these number will be displayed at umount time
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*/
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#define EXT_STATS_
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/*
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* ext4_inode has i_block array (60 bytes total)
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* first 12 bytes store ext4_extent_header
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* the remain stores array of ext4_extent
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*/
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/*
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* this is extent on-disk structure
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* it's used at the bottom of the tree
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*/
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struct ext4_extent {
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__le32 ee_block; /* first logical block extent covers */
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__le16 ee_len; /* number of blocks covered by extent */
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__le16 ee_start_hi; /* high 16 bits of physical block */
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__le32 ee_start; /* low 32 bigs of physical block */
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};
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/*
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* this is index on-disk structure
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* it's used at all the levels, but the bottom
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*/
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struct ext4_extent_idx {
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__le32 ei_block; /* index covers logical blocks from 'block' */
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__le32 ei_leaf; /* pointer to the physical block of the next *
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* level. leaf or next index could bet here */
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__le16 ei_leaf_hi; /* high 16 bits of physical block */
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__u16 ei_unused;
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};
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/*
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* each block (leaves and indexes), even inode-stored has header
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*/
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struct ext4_extent_header {
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__le16 eh_magic; /* probably will support different formats */
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__le16 eh_entries; /* number of valid entries */
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__le16 eh_max; /* capacity of store in entries */
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__le16 eh_depth; /* has tree real underlaying blocks? */
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__le32 eh_generation; /* generation of the tree */
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};
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#define EXT4_EXT_MAGIC cpu_to_le16(0xf30a)
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/*
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* array of ext4_ext_path contains path to some extent
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* creation/lookup routines use it for traversal/splitting/etc
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* truncate uses it to simulate recursive walking
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*/
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struct ext4_ext_path {
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__u32 p_block;
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__u16 p_depth;
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struct ext4_extent *p_ext;
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struct ext4_extent_idx *p_idx;
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struct ext4_extent_header *p_hdr;
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struct buffer_head *p_bh;
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};
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/*
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* structure for external API
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*/
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#define EXT4_EXT_CACHE_NO 0
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#define EXT4_EXT_CACHE_GAP 1
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#define EXT4_EXT_CACHE_EXTENT 2
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/*
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* to be called by ext4_ext_walk_space()
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* negative retcode - error
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* positive retcode - signal for ext4_ext_walk_space(), see below
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* callback must return valid extent (passed or newly created)
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*/
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typedef int (*ext_prepare_callback)(struct inode *, struct ext4_ext_path *,
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struct ext4_ext_cache *,
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void *);
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#define EXT_CONTINUE 0
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#define EXT_BREAK 1
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#define EXT_REPEAT 2
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#define EXT_MAX_BLOCK 0xffffffff
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#define EXT_FIRST_EXTENT(__hdr__) \
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((struct ext4_extent *) (((char *) (__hdr__)) + \
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sizeof(struct ext4_extent_header)))
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#define EXT_FIRST_INDEX(__hdr__) \
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((struct ext4_extent_idx *) (((char *) (__hdr__)) + \
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sizeof(struct ext4_extent_header)))
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#define EXT_HAS_FREE_INDEX(__path__) \
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(le16_to_cpu((__path__)->p_hdr->eh_entries) \
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< le16_to_cpu((__path__)->p_hdr->eh_max))
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#define EXT_LAST_EXTENT(__hdr__) \
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(EXT_FIRST_EXTENT((__hdr__)) + le16_to_cpu((__hdr__)->eh_entries) - 1)
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#define EXT_LAST_INDEX(__hdr__) \
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(EXT_FIRST_INDEX((__hdr__)) + le16_to_cpu((__hdr__)->eh_entries) - 1)
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#define EXT_MAX_EXTENT(__hdr__) \
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(EXT_FIRST_EXTENT((__hdr__)) + le16_to_cpu((__hdr__)->eh_max) - 1)
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#define EXT_MAX_INDEX(__hdr__) \
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(EXT_FIRST_INDEX((__hdr__)) + le16_to_cpu((__hdr__)->eh_max) - 1)
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static inline struct ext4_extent_header *ext_inode_hdr(struct inode *inode)
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{
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return (struct ext4_extent_header *) EXT4_I(inode)->i_data;
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}
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static inline struct ext4_extent_header *ext_block_hdr(struct buffer_head *bh)
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{
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return (struct ext4_extent_header *) bh->b_data;
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}
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static inline unsigned short ext_depth(struct inode *inode)
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{
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return le16_to_cpu(ext_inode_hdr(inode)->eh_depth);
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}
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static inline void ext4_ext_tree_changed(struct inode *inode)
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{
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EXT4_I(inode)->i_ext_generation++;
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}
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static inline void
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ext4_ext_invalidate_cache(struct inode *inode)
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{
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EXT4_I(inode)->i_cached_extent.ec_type = EXT4_EXT_CACHE_NO;
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}
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extern int ext4_extent_tree_init(handle_t *, struct inode *);
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extern int ext4_ext_calc_credits_for_insert(struct inode *, struct ext4_ext_path *);
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extern int ext4_ext_insert_extent(handle_t *, struct inode *, struct ext4_ext_path *, struct ext4_extent *);
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extern int ext4_ext_walk_space(struct inode *, unsigned long, unsigned long, ext_prepare_callback, void *);
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extern struct ext4_ext_path * ext4_ext_find_extent(struct inode *, int, struct ext4_ext_path *);
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#endif /* _LINUX_EXT4_EXTENTS */
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