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>

1 files changed, 0 insertions, 3 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index fa5ca304148e..2b0952974cb9 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -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;
 }