Commit ad9f0126 authored by Jim Harris's avatar Jim Harris Committed by Daniel Verkamp
Browse files

bdev: unwind before invoking remove_cb during unregister 



This avoids recursion in the case where the remove_cb
immediately closes its open descriptor, resulting in
a second call to spdk_bdev_unregister without unwinding
first.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: I093786f13bb2953b8f08888a668a045581a9f81c
Reviewed-on: https://review.gerrithub.io/400305


Reviewed-by: default avatarPaul Luse <paul.e.luse@intel.com>
Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent e7285749

lib/bdev/bdev.c

+15 −3
Original line number Diff line number Diff line
@@ -2161,6 +2161,14 @@ spdk_bdev_unregister_done(struct spdk_bdev *bdev, int bdeverrno) 
	}

}



static void

_remove_notify(void *arg)

{

	struct spdk_bdev_desc *desc = arg;



	desc->remove_cb(desc->remove_ctx);

}



void

spdk_bdev_unregister(struct spdk_bdev *bdev, spdk_bdev_unregister_cb cb_fn, void *cb_arg)

{
@@ -2185,10 +2193,14 @@ spdk_bdev_unregister(struct spdk_bdev *bdev, spdk_bdev_unregister_cb cb_fn, void 


	TAILQ_FOREACH_SAFE(desc, &bdev->open_descs, link, tmp) {

		if (desc->remove_cb) {

			pthread_mutex_unlock(&bdev->mutex);

			do_destruct = false;

			desc->remove_cb(desc->remove_ctx);

			pthread_mutex_lock(&bdev->mutex);

			/*

			 * Defer invocation of the remove_cb to a separate message that will

			 *  run later on this thread.  This ensures this context unwinds and

			 *  we don't recursively unregister this bdev again if the remove_cb

			 *  immediately closes its descriptor.

			 */

			spdk_thread_send_msg(spdk_get_thread(), _remove_notify, desc);

		}

	}