Commit d969bd72 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

iomap: support ioends for direct reads 



Support using the ioend structure to defer I/O completion for direct
reads in addition to writes.  This requires a check for the operation
to not merge reads and writes in iomap_ioend_can_merge.  This support
will be used for bounce buffered direct I/O reads that need to copy
data back to the user address space on read completion.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Tested-by: default avatarAnuj Gupta <anuj20.g@samsung.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent c96b8b22

fs/iomap/ioend.c

+8 −0
Original line number Diff line number Diff line
@@ -299,6 +299,14 @@ EXPORT_SYMBOL_GPL(iomap_finish_ioends); 
static bool iomap_ioend_can_merge(struct iomap_ioend *ioend,

		struct iomap_ioend *next)

{

	/*

	 * There is no point in merging reads as there is no completion

	 * processing that can be easily batched up for them.

	 */

	if (bio_op(&ioend->io_bio) == REQ_OP_READ ||

	    bio_op(&next->io_bio) == REQ_OP_READ)

		return false;



	if (ioend->io_bio.bi_status != next->io_bio.bi_status)

		return false;

	if (next->io_flags & IOMAP_IOEND_BOUNDARY)