Commit 02afc27f authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Al Viro
Browse files

direct-io: Handle O_(D)SYNC AIO 



Call generic_write_sync() from the deferred I/O completion handler if
O_DSYNC is set for a write request.  Also make sure various callers
don't call generic_write_sync if the direct I/O code returns
-EIOCBQUEUED.

Based on an earlier patch from Jan Kara <jack@suse.cz> with updates from
Jeff Moyer <jmoyer@redhat.com> and Darrick J. Wong <darrick.wong@oracle.com>.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 7b7a8665

fs/block_dev.c

+1 −1
Original line number Diff line number Diff line
@@ -1519,7 +1519,7 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov, 


	blk_start_plug(&plug);

	ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);

	if (ret > 0 || ret == -EIOCBQUEUED) {

	if (ret > 0) {

		ssize_t err;



		err = generic_write_sync(file, pos, ret);

fs/btrfs/file.c

+1 −1
Original line number Diff line number Diff line
@@ -1727,7 +1727,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb, 
	 */

	BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;

	BTRFS_I(inode)->last_sub_trans = root->log_transid;

	if (num_written > 0 || num_written == -EIOCBQUEUED) {

	if (num_written > 0) {

		err = generic_write_sync(file, pos, num_written);

		if (err < 0 && num_written > 0)

			num_written = err;

fs/cifs/file.c

+1 −1
Original line number Diff line number Diff line
@@ -2553,7 +2553,7 @@ cifs_writev(struct kiocb *iocb, const struct iovec *iov, 
		mutex_unlock(&inode->i_mutex);

	}



	if (rc > 0 || rc == -EIOCBQUEUED) {

	if (rc > 0) {

		ssize_t err;



		err = generic_write_sync(file, pos, rc);

fs/direct-io.c

+36 −9
Original line number Diff line number Diff line
@@ -266,8 +266,18 @@ static ssize_t dio_complete(struct dio *dio, loff_t offset, ssize_t ret, 
		dio->end_io(dio->iocb, offset, transferred, dio->private);



	inode_dio_done(dio->inode);

	if (is_async)

	if (is_async) {

		if (dio->rw & WRITE) {

			int err;



			err = generic_write_sync(dio->iocb->ki_filp, offset,

						 transferred);

			if (err < 0 && ret > 0)

				ret = err;

		}



		aio_complete(dio->iocb, ret, 0);

	}



	kmem_cache_free(dio_cache, dio);

	return ret;
@@ -1182,11 +1192,6 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, 
		}

	}



	/*

	 * Will be decremented at I/O completion time.

	 */

	atomic_inc(&inode->i_dio_count);



	/*

	 * For file extending writes updating i_size before data

	 * writeouts complete can expose uninitialized blocks. So
@@ -1195,11 +1200,33 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, 
	 */

	dio->is_async = !is_sync_kiocb(iocb) && !((rw & WRITE) &&

		(end > i_size_read(inode)));



	retval = 0;



	dio->inode = inode;

	dio->rw = rw;



	/*

	 * For AIO O_(D)SYNC writes we need to defer completions to a workqueue

	 * so that we can call ->fsync.

	 */

	if (dio->is_async && (rw & WRITE) &&

	    ((iocb->ki_filp->f_flags & O_DSYNC) ||

	     IS_SYNC(iocb->ki_filp->f_mapping->host))) {

		retval = dio_set_defer_completion(dio);

		if (retval) {

			/*

			 * We grab i_mutex only for reads so we don't have

			 * to release it here

			 */

			kmem_cache_free(dio_cache, dio);

			goto out;

		}

	}



	/*

	 * Will be decremented at I/O completion time.

	 */

	atomic_inc(&inode->i_dio_count);



	retval = 0;

	sdio.blkbits = blkbits;

	sdio.blkfactor = i_blkbits - blkbits;

	sdio.block_in_file = offset >> blkbits;

fs/ext4/file.c

+1 −1
Original line number Diff line number Diff line
@@ -149,7 +149,7 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov, 
	ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);

	mutex_unlock(&inode->i_mutex);



	if (ret > 0 || ret == -EIOCBQUEUED) {

	if (ret > 0) {

		ssize_t err;



		err = generic_write_sync(file, pos, ret);

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