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ext4: remove single extent cache

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Single extent cache could be removed because we have extent status tree
as a extent cache, and it would be better.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan kara <jack@suse.cz>
This commit is contained in:
Zheng Liu 2013-02-18 00:31:07 -05:00 committed by Theodore Ts'o
parent d100eef244
commit 69eb33dc24
5 changed files with 38 additions and 163 deletions
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12
fs/ext4/ext4.h
View file

@ -809,17 +809,6 @@ do { \
#endif /* defined(__KERNEL__) || defined(__linux__) */
/*
* storage for cached extent
* If ec_len == 0, then the cache is invalid.
* If ec_start == 0, then the cache represents a gap (null mapping)
*/
struct ext4_ext_cache {
ext4_fsblk_t ec_start;
ext4_lblk_t ec_block;
__u32 ec_len; /* must be 32bit to return holes */
};
#include "extents_status.h"
/*
@ -886,7 +875,6 @@ struct ext4_inode_info {
struct inode vfs_inode;
struct jbd2_inode *jinode;
struct ext4_ext_cache i_cached_extent;
/*
* File creation time. Its function is same as that of
* struct timespec i_{a,c,m}time in the generic inode.

6
fs/ext4/ext4_extents.h
View file

@ -193,12 +193,6 @@ static inline unsigned short ext_depth(struct inode *inode)
return le16_to_cpu(ext_inode_hdr(inode)->eh_depth);
}
static inline void
ext4_ext_invalidate_cache(struct inode *inode)
{
EXT4_I(inode)->i_cached_extent.ec_len = 0;
}
static inline void ext4_ext_mark_uninitialized(struct ext4_extent *ext)
{
/* We can not have an uninitialized extent of zero length! */

179
fs/ext4/extents.c
View file

@ -112,7 +112,7 @@ static int ext4_split_extent_at(handle_t *handle,
int flags);
static int ext4_find_delayed_extent(struct inode *inode,
struct ext4_ext_cache *newex);
struct extent_status *newes);
static int ext4_ext_truncate_extend_restart(handle_t *handle,
struct inode *inode,
@ -714,7 +714,6 @@ int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
eh->eh_magic = EXT4_EXT_MAGIC;
eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
ext4_mark_inode_dirty(handle, inode);
ext4_ext_invalidate_cache(inode);
return 0;
}
@ -1963,7 +1962,6 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
ext4_ext_drop_refs(npath);
kfree(npath);
}
ext4_ext_invalidate_cache(inode);
return err;
}
@ -1972,8 +1970,8 @@ static int ext4_fill_fiemap_extents(struct inode *inode,
struct fiemap_extent_info *fieinfo)
{
struct ext4_ext_path *path = NULL;
struct ext4_ext_cache newex;
struct ext4_extent *ex;
struct extent_status es;
ext4_lblk_t next, next_del, start = 0, end = 0;
ext4_lblk_t last = block + num;
int exists, depth = 0, err = 0;
@ -2047,31 +2045,31 @@ static int ext4_fill_fiemap_extents(struct inode *inode,
BUG_ON(end <= start);
if (!exists) {
newex.ec_block = start;
newex.ec_len = end - start;
newex.ec_start = 0;
es.es_lblk = start;
es.es_len = end - start;
es.es_pblk = 0;
} else {
newex.ec_block = le32_to_cpu(ex->ee_block);
newex.ec_len = ext4_ext_get_actual_len(ex);
newex.ec_start = ext4_ext_pblock(ex);
es.es_lblk = le32_to_cpu(ex->ee_block);
es.es_len = ext4_ext_get_actual_len(ex);
es.es_pblk = ext4_ext_pblock(ex);
if (ext4_ext_is_uninitialized(ex))
flags |= FIEMAP_EXTENT_UNWRITTEN;
}
/*
* Find delayed extent and update newex accordingly. We call
* it even in !exists case to find out whether newex is the
* Find delayed extent and update es accordingly. We call
* it even in !exists case to find out whether es is the
* last existing extent or not.
*/
next_del = ext4_find_delayed_extent(inode, &newex);
next_del = ext4_find_delayed_extent(inode, &es);
if (!exists && next_del) {
exists = 1;
flags |= FIEMAP_EXTENT_DELALLOC;
}
up_read(&EXT4_I(inode)->i_data_sem);
if (unlikely(newex.ec_len == 0)) {
EXT4_ERROR_INODE(inode, "newex.ec_len == 0");
if (unlikely(es.es_len == 0)) {
EXT4_ERROR_INODE(inode, "es.es_len == 0");
err = -EIO;
break;
}
@ -2102,9 +2100,9 @@ static int ext4_fill_fiemap_extents(struct inode *inode,
if (exists) {
err = fiemap_fill_next_extent(fieinfo,
(__u64)newex.ec_block << blksize_bits,
(__u64)newex.ec_start << blksize_bits,
(__u64)newex.ec_len << blksize_bits,
(__u64)es.es_lblk << blksize_bits,
(__u64)es.es_pblk << blksize_bits,
(__u64)es.es_len << blksize_bits,
flags);
if (err < 0)
break;
@ -2114,7 +2112,7 @@ static int ext4_fill_fiemap_extents(struct inode *inode,
}
}
block = newex.ec_block + newex.ec_len;
block = es.es_lblk + es.es_len;
}
if (path) {
@ -2125,21 +2123,6 @@ static int ext4_fill_fiemap_extents(struct inode *inode,
return err;
}
static void
ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
__u32 len, ext4_fsblk_t start)
{
struct ext4_ext_cache *cex;
BUG_ON(len == 0);
spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
trace_ext4_ext_put_in_cache(inode, block, len, start);
cex = &EXT4_I(inode)->i_cached_extent;
cex->ec_block = block;
cex->ec_len = len;
cex->ec_start = start;
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
}
/*
* ext4_ext_put_gap_in_cache:
* calculate boundaries of the gap that the requested block fits into
@ -2156,9 +2139,10 @@ ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
ex = path[depth].p_ext;
if (ex == NULL) {
/* there is no extent yet, so gap is [0;-] */
lblock = 0;
len = EXT_MAX_BLOCKS;
/*
* there is no extent yet, so gap is [0;-] and we
* don't cache it
*/
ext_debug("cache gap(whole file):");
} else if (block < le32_to_cpu(ex->ee_block)) {
lblock = block;
@ -2192,52 +2176,6 @@ ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
}
ext_debug(" -> %u:%lu\n", lblock, len);
ext4_ext_put_in_cache(inode, lblock, len, 0);
}
/*
* ext4_ext_in_cache()
* Checks to see if the given block is in the cache.
* If it is, the cached extent is stored in the given
* cache extent pointer.
*
* @inode: The files inode
* @block: The block to look for in the cache
* @ex: Pointer where the cached extent will be stored
* if it contains block
*
* Return 0 if cache is invalid; 1 if the cache is valid
*/
static int
ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
struct ext4_extent *ex)
{
struct ext4_ext_cache *cex;
int ret = 0;
/*
* We borrow i_block_reservation_lock to protect i_cached_extent
*/
spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
cex = &EXT4_I(inode)->i_cached_extent;
/* has cache valid data? */
if (cex->ec_len == 0)
goto errout;
if (in_range(block, cex->ec_block, cex->ec_len)) {
ex->ee_block = cpu_to_le32(cex->ec_block);
ext4_ext_store_pblock(ex, cex->ec_start);
ex->ee_len = cpu_to_le16(cex->ec_len);
ext_debug("%u cached by %u:%u:%llu\n",
block,
cex->ec_block, cex->ec_len, cex->ec_start);
ret = 1;
}
errout:
trace_ext4_ext_in_cache(inode, block, ret);
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
return ret;
}
/*
@ -2677,8 +2615,6 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
return PTR_ERR(handle);
again:
ext4_ext_invalidate_cache(inode);
trace_ext4_ext_remove_space(inode, start, depth);
/*
@ -3920,35 +3856,6 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
map->m_lblk, map->m_len, inode->i_ino);
trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
/* check in cache */
if (ext4_ext_in_cache(inode, map->m_lblk, &newex)) {
if (!newex.ee_start_lo && !newex.ee_start_hi) {
if ((sbi->s_cluster_ratio > 1) &&
ext4_find_delalloc_cluster(inode, map->m_lblk))
map->m_flags |= EXT4_MAP_FROM_CLUSTER;
if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
/*
* block isn't allocated yet and
* user doesn't want to allocate it
*/
goto out2;
}
/* we should allocate requested block */
} else {
/* block is already allocated */
if (sbi->s_cluster_ratio > 1)
map->m_flags |= EXT4_MAP_FROM_CLUSTER;
newblock = map->m_lblk
- le32_to_cpu(newex.ee_block)
+ ext4_ext_pblock(&newex);
/* number of remaining blocks in the extent */
allocated = ext4_ext_get_actual_len(&newex) -
(map->m_lblk - le32_to_cpu(newex.ee_block));
goto out;
}
}
/* find extent for this block */
path = ext4_ext_find_extent(inode, map->m_lblk, NULL);
if (IS_ERR(path)) {
@ -3995,15 +3902,9 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
ee_block, ee_len, newblock);
/*
* Do not put uninitialized extent
* in the cache
*/
if (!ext4_ext_is_uninitialized(ex)) {
ext4_ext_put_in_cache(inode, ee_block,
ee_len, ee_start);
if (!ext4_ext_is_uninitialized(ex))
goto out;
}
allocated = ext4_ext_handle_uninitialized_extents(
handle, inode, map, path, flags,
allocated, newblock);
@ -4265,10 +4166,9 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
* Cache the extent and update transaction to commit on fdatasync only
* when it is _not_ an uninitialized extent.
*/
if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) {
ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock);
if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0)
ext4_update_inode_fsync_trans(handle, inode, 1);
} else
else
ext4_update_inode_fsync_trans(handle, inode, 0);
out:
if (allocated > map->m_len)
@ -4327,7 +4227,6 @@ void ext4_ext_truncate(struct inode *inode)
goto out_stop;
down_write(&EXT4_I(inode)->i_data_sem);
ext4_ext_invalidate_cache(inode);
ext4_discard_preallocations(inode);
@ -4576,42 +4475,42 @@ int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
}
/*
* If newex is not existing extent (newex->ec_start equals zero) find
* delayed extent at start of newex and update newex accordingly and
* If newes is not existing extent (newes->ec_pblk equals zero) find
* delayed extent at start of newes and update newes accordingly and
* return start of the next delayed extent.
*
* If newex is existing extent (newex->ec_start is not equal zero)
* If newes is existing extent (newes->ec_pblk is not equal zero)
* return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
* extent found. Leave newex unmodified.
* extent found. Leave newes unmodified.
*/
static int ext4_find_delayed_extent(struct inode *inode,
struct ext4_ext_cache *newex)
struct extent_status *newes)
{
struct extent_status es;
ext4_lblk_t block, next_del;
ext4_es_find_delayed_extent(inode, newex->ec_block, &es);
ext4_es_find_delayed_extent(inode, newes->es_lblk, &es);
if (newex->ec_start == 0) {
if (newes->es_pblk == 0) {
/*
* No extent in extent-tree contains block @newex->ec_start,
* No extent in extent-tree contains block @newes->es_pblk,
* then the block may stay in 1)a hole or 2)delayed-extent.
*/
if (es.es_len == 0)
/* A hole found. */
return 0;
if (es.es_lblk > newex->ec_block) {
if (es.es_lblk > newes->es_lblk) {
/* A hole found. */
newex->ec_len = min(es.es_lblk - newex->ec_block,
newex->ec_len);
newes->es_len = min(es.es_lblk - newes->es_lblk,
newes->es_len);
return 0;
}
newex->ec_len = es.es_lblk + es.es_len - newex->ec_block;
newes->es_len = es.es_lblk + es.es_len - newes->es_lblk;
}
block = newex->ec_block + newex->ec_len;
block = newes->es_lblk + newes->es_len;
ext4_es_find_delayed_extent(inode, block, &es);
if (es.es_len == 0)
next_del = EXT_MAX_BLOCKS;
@ -4815,14 +4714,12 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
goto out;
down_write(&EXT4_I(inode)->i_data_sem);
ext4_ext_invalidate_cache(inode);
ext4_discard_preallocations(inode);
err = ext4_es_remove_extent(inode, first_block,
stop_block - first_block);
err = ext4_ext_remove_space(inode, first_block, stop_block - 1);
ext4_ext_invalidate_cache(inode);
ext4_discard_preallocations(inode);
if (IS_SYNC(inode))

3
fs/ext4/move_extent.c
View file

@ -764,9 +764,6 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
kfree(donor_path);
}
ext4_ext_invalidate_cache(orig_inode);
ext4_ext_invalidate_cache(donor_inode);
return replaced_count;
}

1
fs/ext4/super.c
View file

@ -836,7 +836,6 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
return NULL;
ei->vfs_inode.i_version = 1;
memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
INIT_LIST_HEAD(&ei->i_prealloc_list);
spin_lock_init(&ei->i_prealloc_lock);
ext4_es_init_tree(&ei->i_es_tree);