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| author | Zheng Liu <wenqing.lz@taobao.com> | 2013-02-18 00:29:59 -0500 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2013-02-18 00:29:59 -0500 |
| commit | d100eef2440fea13e4f09e88b1c8bcbca64beb9f (patch) | |
| tree | 2451dc4582b43a30b414c89108b75148d48c9b57 /fs/ext4/extents.c | |
| parent | f7fec032aa782d3fd7e51fbdf08aa3a296c01500 (diff) | |
| download | linux-d100eef2440fea13e4f09e88b1c8bcbca64beb9f.tar.bz2 | |
ext4: lookup block mapping in extent status tree
After tracking all extent status, we already have a extent cache in
memory. Every time we want to lookup a block mapping, we can first
try to lookup it in extent status tree to avoid a potential disk I/O.
A new function called ext4_es_lookup_extent is defined to finish this
work. When we try to lookup a block mapping, we always call
ext4_map_blocks and/or ext4_da_map_blocks. So in these functions we
first try to lookup a block mapping in extent status tree.
A new flag EXT4_GET_BLOCKS_NO_PUT_HOLE is used in ext4_da_map_blocks
in order not to put a hole into extent status tree because this hole
will be converted to delayed extent in the tree immediately.
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan kara <jack@suse.cz>
Diffstat (limited to 'fs/ext4/extents.c')
| -rw-r--r-- | fs/ext4/extents.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index be0b1b3eed97..b9d7a2363736 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2167,6 +2167,9 @@ ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, block, le32_to_cpu(ex->ee_block), ext4_ext_get_actual_len(ex)); + if (!ext4_find_delalloc_range(inode, lblock, lblock + len - 1)) + ext4_es_insert_extent(inode, lblock, len, ~0, + EXTENT_STATUS_HOLE); } else if (block >= le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex)) { ext4_lblk_t next; @@ -2180,6 +2183,9 @@ ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, block); BUG_ON(next == lblock); len = next - lblock; + if (!ext4_find_delalloc_range(inode, lblock, lblock + len - 1)) + ext4_es_insert_extent(inode, lblock, len, ~0, + EXTENT_STATUS_HOLE); } else { lblock = len = 0; BUG(); @@ -4018,7 +4024,8 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, * put just found gap into cache to speed up * subsequent requests */ - ext4_ext_put_gap_in_cache(inode, path, map->m_lblk); + if ((flags & EXT4_GET_BLOCKS_NO_PUT_HOLE) == 0) + ext4_ext_put_gap_in_cache(inode, path, map->m_lblk); goto out2; } |