alistair23-linux/fs/ext4/extents_status.h
Zheng Liu adb2355104 ext4: update extent status tree after an extent is zeroed out
When we try to split an extent, this extent could be zeroed out and mark
as initialized.  But we don't know this in ext4_map_blocks because it
only returns a length of allocated extent.  Meanwhile we will mark this
extent as uninitialized because we only check m_flags.

This commit update extent status tree when we try to split an unwritten
extent.  We don't need to worry about the status of this extent because
we always mark it as initialized.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Dmitry Monakhov <dmonakhov@openvz.org>
2013-03-10 21:13:05 -04:00

127 lines
3.4 KiB
C

/*
* fs/ext4/extents_status.h
*
* Written by Yongqiang Yang <xiaoqiangnk@gmail.com>
* Modified by
* Allison Henderson <achender@linux.vnet.ibm.com>
* Zheng Liu <wenqing.lz@taobao.com>
*
*/
#ifndef _EXT4_EXTENTS_STATUS_H
#define _EXT4_EXTENTS_STATUS_H
/*
* Turn on ES_DEBUG__ to get lots of info about extent status operations.
*/
#ifdef ES_DEBUG__
#define es_debug(fmt, ...) printk(fmt, ##__VA_ARGS__)
#else
#define es_debug(fmt, ...) no_printk(fmt, ##__VA_ARGS__)
#endif
/*
* With ES_AGGRESSIVE_TEST defined, the result of es caching will be
* checked with old map_block's result.
*/
#define ES_AGGRESSIVE_TEST__
/*
* These flags live in the high bits of extent_status.es_pblk
*/
#define EXTENT_STATUS_WRITTEN (1ULL << 63)
#define EXTENT_STATUS_UNWRITTEN (1ULL << 62)
#define EXTENT_STATUS_DELAYED (1ULL << 61)
#define EXTENT_STATUS_HOLE (1ULL << 60)
#define EXTENT_STATUS_FLAGS (EXTENT_STATUS_WRITTEN | \
EXTENT_STATUS_UNWRITTEN | \
EXTENT_STATUS_DELAYED | \
EXTENT_STATUS_HOLE)
struct ext4_extent;
struct extent_status {
struct rb_node rb_node;
ext4_lblk_t es_lblk; /* first logical block extent covers */
ext4_lblk_t es_len; /* length of extent in block */
ext4_fsblk_t es_pblk; /* first physical block */
};
struct ext4_es_tree {
struct rb_root root;
struct extent_status *cache_es; /* recently accessed extent */
};
extern int __init ext4_init_es(void);
extern void ext4_exit_es(void);
extern void ext4_es_init_tree(struct ext4_es_tree *tree);
extern int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
ext4_lblk_t len, ext4_fsblk_t pblk,
unsigned long long status);
extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
ext4_lblk_t len);
extern void ext4_es_find_delayed_extent(struct inode *inode, ext4_lblk_t lblk,
struct extent_status *es);
extern int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
struct extent_status *es);
extern int ext4_es_zeroout(struct inode *inode, struct ext4_extent *ex);
static inline int ext4_es_is_written(struct extent_status *es)
{
return (es->es_pblk & EXTENT_STATUS_WRITTEN) != 0;
}
static inline int ext4_es_is_unwritten(struct extent_status *es)
{
return (es->es_pblk & EXTENT_STATUS_UNWRITTEN) != 0;
}
static inline int ext4_es_is_delayed(struct extent_status *es)
{
return (es->es_pblk & EXTENT_STATUS_DELAYED) != 0;
}
static inline int ext4_es_is_hole(struct extent_status *es)
{
return (es->es_pblk & EXTENT_STATUS_HOLE) != 0;
}
static inline ext4_fsblk_t ext4_es_status(struct extent_status *es)
{
return (es->es_pblk & EXTENT_STATUS_FLAGS);
}
static inline ext4_fsblk_t ext4_es_pblock(struct extent_status *es)
{
return (es->es_pblk & ~EXTENT_STATUS_FLAGS);
}
static inline void ext4_es_store_pblock(struct extent_status *es,
ext4_fsblk_t pb)
{
ext4_fsblk_t block;
block = (pb & ~EXTENT_STATUS_FLAGS) |
(es->es_pblk & EXTENT_STATUS_FLAGS);
es->es_pblk = block;
}
static inline void ext4_es_store_status(struct extent_status *es,
unsigned long long status)
{
ext4_fsblk_t block;
block = (status & EXTENT_STATUS_FLAGS) |
(es->es_pblk & ~EXTENT_STATUS_FLAGS);
es->es_pblk = block;
}
extern void ext4_es_register_shrinker(struct super_block *sb);
extern void ext4_es_unregister_shrinker(struct super_block *sb);
extern void ext4_es_lru_add(struct inode *inode);
extern void ext4_es_lru_del(struct inode *inode);
#endif /* _EXT4_EXTENTS_STATUS_H */