On Wed 07-11-18 08:45:41, Bart Van Assche wrote:
> Instead of repeating the check whether inode locking is required, perform
> that check once and store the result in a variable. Remove the obsolete
> comment that refers to direct_io_worker() since that function has been
> removed. This patch does not change the behavior of the direct I/O code.
>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Jan Kara <jack@xxxxxxx>
Looks good. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
BTW Jens often merges direct IO patches...
Honza
> ---
> fs/direct-io.c | 30 +++++++++++++-----------------
> 1 file changed, 13 insertions(+), 17 deletions(-)
>
> diff --git a/fs/direct-io.c b/fs/direct-io.c
> index d4a218b45383..b5a691ba2271 100644
> --- a/fs/direct-io.c
> +++ b/fs/direct-io.c
> @@ -1185,6 +1185,8 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
> struct buffer_head map_bh = { 0, };
> struct blk_plug plug;
> unsigned long align = offset | iov_iter_alignment(iter);
> + const bool lock_inode = flags & DIO_LOCKING &&
> + iov_iter_rw(iter) == READ;
>
> /*
> * Avoid references to bdev if not absolutely needed to give
> @@ -1215,28 +1217,22 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
> memset(dio, 0, offsetof(struct dio, pages));
>
> dio->flags = flags;
> - if (dio->flags & DIO_LOCKING) {
> - if (iov_iter_rw(iter) == READ) {
> - struct address_space *mapping =
> - iocb->ki_filp->f_mapping;
> -
> - /* will be released by direct_io_worker */
> - inode_lock(inode);
> -
> - retval = filemap_write_and_wait_range(mapping, offset,
> - end - 1);
> - if (retval) {
> - inode_unlock(inode);
> - kmem_cache_free(dio_cache, dio);
> - goto out;
> - }
> + if (lock_inode) {
> + struct address_space *mapping = iocb->ki_filp->f_mapping;
> +
> + inode_lock(inode);
> + retval = filemap_write_and_wait_range(mapping, offset, end - 1);
> + if (retval) {
> + inode_unlock(inode);
> + kmem_cache_free(dio_cache, dio);
> + goto out;
> }
> }
>
> /* Once we sampled i_size check for reads beyond EOF */
> dio->i_size = i_size_read(inode);
> if (iov_iter_rw(iter) == READ && offset >= dio->i_size) {
> - if (dio->flags & DIO_LOCKING)
> + if (lock_inode)
> inode_unlock(inode);
> kmem_cache_free(dio_cache, dio);
> retval = 0;
> @@ -1370,7 +1366,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
> * we can let i_mutex go now that its achieved its purpose
> * of protecting us from looking up uninitialized blocks.
> */
> - if (iov_iter_rw(iter) == READ && (dio->flags & DIO_LOCKING))
> + if (lock_inode)
> inode_unlock(dio->inode);
>
> /*
> --
> 2.19.1.930.g4563a0d9d0-goog
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
