Commit dfa0618d authored by Jim Harris's avatar Jim Harris Committed by Daniel Verkamp
Browse files

bdev: simplify completion callback deferring 



We can do all of the completion work first, and then
make the decision at the very end on whether to
defer the callback or not.

This also removes the bdev_io defer_callback member -
we no longer need it since we now only defer the
callback itself, instead of deferring the full
execution of the spdk_bdev_io_complete() routine.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: I3285e34d2fbce34d4254dca2119561ff825ee9e8

Reviewed-on: https://review.gerrithub.io/365711


Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
parent 356e2ab2

include/spdk_internal/bdev.h

+0 −5
Original line number Diff line number Diff line
@@ -333,11 +333,6 @@ struct spdk_bdev_io { 
	 */

	bool in_submit_request;



	/**

	 * Set to true when the a bdev_io's callback routine should be deferred after completion.

	 */

	bool defer_callback;



	/** Member used for linking child I/Os together. */

	TAILQ_ENTRY(spdk_bdev_io) link;

lib/bdev/bdev.c

+13 −22
Original line number Diff line number Diff line
@@ -961,7 +961,6 @@ spdk_bdev_reset(struct spdk_bdev *bdev, struct spdk_io_channel *ch, 


	bdev_io->ch = channel;

	bdev_io->type = SPDK_BDEV_IO_TYPE_RESET;

	bdev_io->defer_callback = true;

	spdk_bdev_io_init(bdev_io, bdev, cb_arg, cb);



	/* First, abort all I/O queued up waiting for buffers. */
@@ -1073,13 +1072,12 @@ spdk_bdev_free_io(struct spdk_bdev_io *bdev_io) 
}



static void

bdev_io_deferred_completion(void *ctx)

_spdk_bdev_io_complete(void *ctx)

{

	struct spdk_bdev_io *bdev_io = ctx;



	assert(bdev_io->in_submit_request == false);



	spdk_bdev_io_complete(bdev_io, bdev_io->status);

	assert(bdev_io->cb != NULL);

	bdev_io->cb(bdev_io, bdev_io->status == SPDK_BDEV_IO_STATUS_SUCCESS, bdev_io->caller_ctx);

}



void
@@ -1087,21 +1085,6 @@ spdk_bdev_io_complete(struct spdk_bdev_io *bdev_io, enum spdk_bdev_io_status sta 
{

	bdev_io->status = status;



	if (bdev_io->in_submit_request) {

		bdev_io->defer_callback = true;

	}



	if (bdev_io->defer_callback) {

		/*

		 * Defer completion to avoid potential infinite recursion if the

		 * user's completion callback issues a new I/O.

		 */

		bdev_io->defer_callback = false;

		spdk_thread_send_msg(spdk_io_channel_get_thread(bdev_io->ch->channel),

				     bdev_io_deferred_completion, bdev_io);

		return;

	}



	assert(bdev_io->ch->io_outstanding > 0);

	bdev_io->ch->io_outstanding--;

	if (bdev_io->type == SPDK_BDEV_IO_TYPE_RESET) {
@@ -1156,8 +1139,16 @@ spdk_bdev_io_complete(struct spdk_bdev_io *bdev_io, enum spdk_bdev_io_status sta 
	}

#endif



	assert(bdev_io->cb != NULL);

	bdev_io->cb(bdev_io, status == SPDK_BDEV_IO_STATUS_SUCCESS, bdev_io->caller_ctx);

	if (bdev_io->in_submit_request || bdev_io->type == SPDK_BDEV_IO_TYPE_RESET) {

		/*

		 * Defer completion to avoid potential infinite recursion if the

		 * user's completion callback issues a new I/O.

		 */

		spdk_thread_send_msg(spdk_io_channel_get_thread(bdev_io->ch->channel),

				     _spdk_bdev_io_complete, bdev_io);

	} else {

		_spdk_bdev_io_complete(bdev_io);

	}

}



void