From 53362a05ae683e12a20d9ffdf58a88094a0bed9d Mon Sep 17 00:00:00 2001 From: Jianpeng Ma Date: Thu, 2 Aug 2012 09:50:39 +0200 Subject: [PATCH] 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 Reviewed-by: NeilBrown Signed-off-by: Jens Axboe --- fs/block_dev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/block_dev.c b/fs/block_dev.c index 1e519195d45b..38e721b35d45 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1578,10 +1578,12 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov, 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 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov, if (err < 0 && ret > 0) ret = err; } + blk_finish_plug(&plug); return ret; } EXPORT_SYMBOL_GPL(blkdev_aio_write);