Normally, DIO uses in-pllace-update, but in LFS mode, f2fs doesn't
allow triggering any in-place-update writes, so we fallback direct
write to buffered write, result in bad performance of large size
write.
This patch adds to support triggering out-place-update for direct IO
to enhance its performance.
Note that it needs to exclude direct read IO during direct write,
since new data writing to new block address will no be valid until
write finished.
storage: zram
time xfs_io -f -d /mnt/f2fs/file -c "pwrite 0 1073741824" -c "fsync"
Before:
real 0m13.061s
user 0m0.327s
sys 0m12.486s
After:
real 0m6.448s
user 0m0.228s
sys 0m6.212s
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f847c699cf