Commit 8430f977 authored Aug 09, 2012 by Fengguang Wu Committed by Jens Axboe Aug 09, 2012

block: remove plugging at buffered write time



Buffered write(2) is not directly tied to IO, so it's not suitable to
handle plug in generic_file_aio_write().

Note that plugging for O_SYNC writes is also removed. The user may pass
arbitrary @size arguments, which may be much larger than the preferable
I/O size, or may cross extent/device boundaries. Let the lower layers
handle the plugging. The plugging code here actually turns them into
no-ops.

CC: Li Shaohua <shli@fusionio.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 276f0f5d

mm/filemap.c

+0 −3

Original line number	Diff line number	Diff line
		@@ -2527,14 +2527,12 @@ ssize_t generic_file_aio_write(struct kiocb iocb, const struct iovec iov,
		{
		struct file *file = iocb->ki_filp;
		struct inode *inode = file->f_mapping->host;
		struct blk_plug plug;
		ssize_t ret;

		BUG_ON(iocb->ki_pos != pos);

		sb_start_write(inode->i_sb);
		mutex_lock(&inode->i_mutex);
		blk_start_plug(&plug);
		ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
		mutex_unlock(&inode->i_mutex);

		@@ -2545,7 +2543,6 @@ ssize_t generic_file_aio_write(struct kiocb iocb, const struct iovec iov,
		if (err < 0 && ret > 0)
		ret = err;
		}
		blk_finish_plug(&plug);
		sb_end_write(inode->i_sb);
		return ret;
		}