Commit 130d278a authored by Paul Luse's avatar Paul Luse Committed by Daniel Verkamp
Browse files

blob: defer calling unload callback until dev is destroyed 



Fixes condition where blobstore was prematurely calling the
application callback on spdk_bs_unload(), if the application
tries to do something too quickly bad things happen.

To avoid application changes with how the g_devlist_mutex is
held, it is no longer held while calling
_spdk_io_device_attempt_free() because the app unload CB is
called from that function and may want to call
spdk_io_device_unregister() from its unload CB.  So the lock
is now held and releases strictly around the list its
protecting which allows the CB from _spdk_io_device_attempt_free()
to be called without issue.

Change-Id: Ib451cfe6b33ea0c3f9e66c86785316f9d88837c7
Signed-off-by: default avatarPaul Luse <paul.e.luse@intel.com>
Reviewed-on: https://review.gerrithub.io/377872


Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
parent 4affd37f

lib/blob/blobstore.c

+14 −1
Original line number Diff line number Diff line
@@ -44,7 +44,6 @@ 
#include "spdk_internal/log.h"



#include "blobstore.h"

#include "request.h"



#define BLOB_CRC32C_INITIAL    0xffffffffUL
@@ -1342,6 +1341,12 @@ _spdk_bs_dev_destroy(void *io_device) 


	spdk_bit_array_free(&bs->used_md_pages);

	spdk_bit_array_free(&bs->used_clusters);

	/*

	 * If this function is called for any reason except a successful unload,

	 * the unload_cpl type will be NONE and this will be a nop.

	 */

	spdk_bs_call_cpl(&bs->unload_cpl, bs->unload_err);



	free(bs);

}
@@ -1833,6 +1838,14 @@ _spdk_bs_unload_write_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserr 


	spdk_dma_free(ctx->super);



	/*

	 * We need to defer calling spdk_bs_call_cpl() until after

	 * dev destuction, so tuck these away for later use.

	 */

	ctx->bs->unload_err = bserrno;

	memcpy(&ctx->bs->unload_cpl, &seq->cpl, sizeof(struct spdk_bs_cpl));

	seq->cpl.type = SPDK_BS_CPL_TYPE_NONE;



	spdk_bs_sequence_finish(seq, bserrno);



	_spdk_bs_free(ctx->bs);

lib/blob/blobstore.h

+5 −0
Original line number Diff line number Diff line
@@ -39,6 +39,8 @@ 
#include "spdk/queue.h"

#include "spdk/util.h"



#include "request.h"



/* In Memory Data Structures

 *

 * The following data structures exist only in memory.
@@ -156,6 +158,9 @@ struct spdk_blob_store { 


	spdk_blob_id			super_blob;



	struct spdk_bs_cpl		unload_cpl;

	int				unload_err;



	TAILQ_HEAD(, spdk_blob) 	blobs;

};

lib/blob/request.c

+3 −0
Original line number Diff line number Diff line
@@ -73,6 +73,9 @@ spdk_bs_call_cpl(struct spdk_bs_cpl *cpl, int bserrno) 
					cpl->u.nested_seq.parent,

					bserrno);

		break;

	case SPDK_BS_CPL_TYPE_NONE:

		/* this completion's callback is handled elsewhere */

		break;

	}

}

lib/blob/request.h

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ 
#include "spdk/blob.h"



enum spdk_bs_cpl_type {

	SPDK_BS_CPL_TYPE_NONE,

	SPDK_BS_CPL_TYPE_BS_BASIC,

	SPDK_BS_CPL_TYPE_BS_HANDLE,

	SPDK_BS_CPL_TYPE_BLOB_BASIC,

lib/util/io_channel.c

+5 −5
Original line number Diff line number Diff line
@@ -241,6 +241,7 @@ _spdk_io_device_attempt_free(struct io_device *dev) 
	struct spdk_thread *thread;

	struct spdk_io_channel *ch;



	pthread_mutex_lock(&g_devlist_mutex);

	TAILQ_FOREACH(thread, &g_threads, tailq) {

		TAILQ_FOREACH(ch, &thread->io_channels, tailq) {

			if (ch->dev == dev) {
@@ -248,10 +249,12 @@ _spdk_io_device_attempt_free(struct io_device *dev) 
				 * device still exists. Defer deletion

				 * until it is removed.

				 */

				pthread_mutex_unlock(&g_devlist_mutex);

				return;

			}

		}

	}

	pthread_mutex_unlock(&g_devlist_mutex);



	if (dev->unregister_cb) {

		dev->unregister_cb(dev->io_device);
@@ -287,9 +290,8 @@ spdk_io_device_unregister(void *io_device, spdk_io_device_unregister_cb unregist 
	dev->unregister_cb = unregister_cb;

	dev->unregistered = true;

	TAILQ_REMOVE(&g_io_devices, dev, tailq);

	_spdk_io_device_attempt_free(dev);



	pthread_mutex_unlock(&g_devlist_mutex);

	_spdk_io_device_attempt_free(dev);

}



struct spdk_io_channel *
@@ -377,15 +379,13 @@ _spdk_put_io_channel(void *arg) 
	ch->destroy_cb(ch->dev->io_device, spdk_io_channel_get_ctx(ch));



	pthread_mutex_lock(&g_devlist_mutex);



	TAILQ_REMOVE(&ch->thread->io_channels, ch, tailq);

	pthread_mutex_unlock(&g_devlist_mutex);



	if (ch->dev->unregistered) {

		_spdk_io_device_attempt_free(ch->dev);

	}

	free(ch);



	pthread_mutex_unlock(&g_devlist_mutex);

}



void