fs/block-dev.c:fix performance regression in O_DIRECT writes to md block devices
For regular file, write operaion used blk_plug function.But for block
file,write operation did not use blk_plug.
This patch is also for write-cache mode for block-device.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 1e51919..38e721b 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1578,10 +1578,12 @@
unsigned long nr_segs, loff_t pos)
{
struct file *file = iocb->ki_filp;
+ struct blk_plug plug;
ssize_t ret;
BUG_ON(iocb->ki_pos != pos);
+ blk_start_plug(&plug);
ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
if (ret > 0 || ret == -EIOCBQUEUED) {
ssize_t err;
@@ -1590,6 +1592,7 @@
if (err < 0 && ret > 0)
ret = err;
}
+ blk_finish_plug(&plug);
return ret;
}
EXPORT_SYMBOL_GPL(blkdev_aio_write);