ext4: optimize ext4_should_retry_alloc() to improve ENOSPC performance
If there are no pending blocks to be released after a commit, forcing
a journal commit has no hope of helping. It's possible that a commit
had just completed, so if there are now free blocks available for
allocation, it's worth retrying the commit.
Reported-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 3020fd7..0b8105b 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -610,7 +610,9 @@
jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id);
- jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal);
+ smp_mb();
+ if (EXT4_SB(sb)->s_mb_free_pending)
+ jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal);
return 1;
}