This patch avoids an extraneous lookup of the extent cache
in ext4_ext_map_blocks() when the flag
EXT4_GET_BLOCKS_PUNCH_OUT_EXT is absent.
The existing logic was performing the lookup but not making
use of the result. The patch simply reverses the order of evaluation
in the condition.
Since ext4_ext_in_cache() does not initialize newex on misses, bypassing
its invocation does not introduce any new issue in this regard.
Signed-off-by: Robin Dong <sanbai@xxxxxxxxxx>
Reviewed-by: Lukas Czerner <lczerner@xxxxxxxxxx>
Reviewed-by: Eric Gouriou <egouriou@xxxxxxxxxx>
---
fs/ext4/extents.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index eb63c7b..fed2633 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3358,8 +3358,8 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
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) &&
- ((flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) == 0)) {
+ if (!(flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) &&
+ ext4_ext_in_cache(inode, map->m_lblk, &newex)) {
if (!newex.ee_start_lo && !newex.ee_start_hi) {
if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
/*
--
1.7.1
--
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