Commit 4fc7e666 authored by Jim Harris's avatar Jim Harris
Browse files

bdev: add vbdev claim/release semantics 



vbdev modules still open/close bdevs as normal, but
should open bdevs read only when tasting (i.e. reading
the GPT to see if there are SPDK partitions).  When
a vbdev module is ready to claim the bdev for purposes
of creating virtual bdevs on top of it, it calls
spdk_vbdev_module_claim_bdev().  It can pass its
open descriptor as well to have it promoted to
write access (required for future vbdev modules like
logical volumes).

Note: error vbdev was changed to copy the base bdev
parameters one-by-one instead of a blind memcpy - we
do not want to copy the base bdev's vbdev_claim_module
into the new bdev!

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: If2ee67dc78daf96050343c473671aa3402991bb1

Reviewed-on: https://review.gerrithub.io/368628


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent 86af2ae5

include/spdk_internal/bdev.h

+5 −1
Original line number Diff line number Diff line
@@ -224,7 +224,7 @@ struct spdk_bdev { 


	bool bdev_opened_for_write;



	uint32_t vbdevs_opened_for_write;

	struct spdk_bdev_module_if *vbdev_claim_module;



	/** List of open descriptors for this block device. */

	TAILQ_HEAD(, spdk_bdev_desc) open_descs;
@@ -385,6 +385,10 @@ void spdk_vbdev_unregister(struct spdk_bdev *vbdev); 


void spdk_vbdev_module_examine_done(struct spdk_bdev_module_if *module);



int spdk_vbdev_module_claim_bdev(struct spdk_bdev *bdev, struct spdk_bdev_desc *desc,

				 struct spdk_bdev_module_if *module);

void spdk_vbdev_module_release_bdev(struct spdk_bdev *bdev);



void spdk_bdev_poller_start(struct spdk_bdev_poller **ppoller,

			    spdk_bdev_poller_fn fn,

			    void *arg,

lib/bdev/bdev.c

+32 −34
Original line number Diff line number Diff line
@@ -1397,7 +1397,6 @@ _spdk_bdev_register(struct spdk_bdev *bdev) 
	bdev->gencnt = 0;

	TAILQ_INIT(&bdev->open_descs);

	bdev->bdev_opened_for_write = false;

	bdev->vbdevs_opened_for_write = 0;



	TAILQ_INIT(&bdev->vbdevs);

	TAILQ_INIT(&bdev->base_bdevs);
@@ -1516,35 +1515,6 @@ spdk_vbdev_module_examine_done(struct spdk_bdev_module_if *module) 
	}

}



static bool

__is_bdev_opened_for_write(struct spdk_bdev *bdev)

{

	struct spdk_bdev *base;



	if (bdev->bdev_opened_for_write) {

		return true;

	}



	TAILQ_FOREACH(base, &bdev->base_bdevs, base_bdev_link) {

		if (__is_bdev_opened_for_write(base)) {

			return true;

		}

	}



	return false;

}



static void

__modify_write_counts(struct spdk_bdev *bdev, int mod)

{

	struct spdk_bdev *base;



	TAILQ_FOREACH(base, &bdev->base_bdevs, base_bdev_link) {

		base->vbdevs_opened_for_write += mod;

		__modify_write_counts(base, mod);

	}

}



int

spdk_bdev_open(struct spdk_bdev *bdev, bool write, spdk_bdev_remove_cb_t remove_cb,

	       void *remove_ctx, struct spdk_bdev_desc **_desc)
@@ -1558,8 +1528,8 @@ spdk_bdev_open(struct spdk_bdev *bdev, bool write, spdk_bdev_remove_cb_t remove_ 


	pthread_mutex_lock(&bdev->mutex);



	if (write && (__is_bdev_opened_for_write(bdev) || bdev->vbdevs_opened_for_write > 0)) {

		SPDK_ERRLOG("failed, %s (or one of its virtual bdevs) already opened for write\n", bdev->name);

	if (write && (bdev->bdev_opened_for_write || bdev->vbdev_claim_module)) {

		SPDK_ERRLOG("failed, %s already opened for write or claimed\n", bdev->name);

		free(desc);

		pthread_mutex_unlock(&bdev->mutex);

		return -EPERM;
@@ -1569,7 +1539,6 @@ spdk_bdev_open(struct spdk_bdev *bdev, bool write, spdk_bdev_remove_cb_t remove_ 


	if (write) {

		bdev->bdev_opened_for_write = true;

		__modify_write_counts(bdev, 1);

	}



	desc->bdev = bdev;
@@ -1594,7 +1563,6 @@ spdk_bdev_close(struct spdk_bdev_desc *desc) 
	if (desc->write) {

		assert(bdev->bdev_opened_for_write);

		bdev->bdev_opened_for_write = false;

		__modify_write_counts(bdev, -1);

	}



	TAILQ_REMOVE(&bdev->open_descs, desc, link);
@@ -1610,6 +1578,36 @@ spdk_bdev_close(struct spdk_bdev_desc *desc) 
	}

}



int

spdk_vbdev_module_claim_bdev(struct spdk_bdev *bdev, struct spdk_bdev_desc *desc,

			     struct spdk_bdev_module_if *module)

{

	if (bdev->vbdev_claim_module != NULL) {

		SPDK_ERRLOG("bdev %s already claimed by module %s\n", bdev->name,

			    bdev->vbdev_claim_module->name);

		return -EPERM;

	}



	if ((!desc || !desc->write) && bdev->bdev_opened_for_write) {

		SPDK_ERRLOG("bdev %s already opened with write access\n", bdev->name);

		return -EPERM;

	}



	if (desc && !desc->write) {

		desc->write = true;

	}



	bdev->vbdev_claim_module = module;

	return 0;

}



void

spdk_vbdev_module_release_bdev(struct spdk_bdev *bdev)

{

	assert(bdev->vbdev_claim_module != NULL);

	bdev->vbdev_claim_module = NULL;

}



void

spdk_bdev_io_get_iovec(struct spdk_bdev_io *bdev_io, struct iovec **iovp, int *iovcntp)

{

lib/bdev/error/vbdev_error.c

+10 −1
Original line number Diff line number Diff line
@@ -259,13 +259,22 @@ spdk_vbdev_error_create(struct spdk_bdev *base_bdev) 
		goto cleanup;

	}



	rc = spdk_vbdev_module_claim_bdev(base_bdev, NULL, SPDK_GET_BDEV_MODULE(error));

	if (rc) {

		SPDK_ERRLOG("could not claim bdev %s\n", spdk_bdev_get_name(base_bdev));

		goto cleanup;

	}



	disk->base_bdev = base_bdev;

	memcpy(&disk->disk, base_bdev, sizeof(*base_bdev));

	disk->disk.name = spdk_sprintf_alloc("EE_%s", base_bdev->name);

	if (!disk->disk.name) {

		rc = -ENOMEM;

		goto cleanup;

	}

	disk->disk.blockcnt = base_bdev->blockcnt;

	disk->disk.blocklen = base_bdev->blocklen;

	disk->disk.write_cache = base_bdev->write_cache;

	disk->disk.max_unmap_bdesc_count = base_bdev->max_unmap_bdesc_count;

	disk->disk.product_name = "Error Injection Disk";

	disk->disk.ctxt = disk;

	disk->disk.fn_table = &vbdev_error_fn_table;

lib/bdev/gpt/vbdev_gpt.c

+15 −3
Original line number Diff line number Diff line
@@ -422,6 +422,8 @@ static void 
spdk_gpt_bdev_complete(struct spdk_bdev_io *bdev_io, bool status, void *arg)

{

	struct spdk_gpt_bdev *gpt_bdev = (struct spdk_gpt_bdev *)arg;

	struct spdk_bdev *bdev = gpt_bdev->bdev;

	bool claimed = false;

	int rc;



	/* free the ch and also close the bdev_desc */
@@ -429,10 +431,11 @@ spdk_gpt_bdev_complete(struct spdk_bdev_io *bdev_io, bool status, void *arg) 
	gpt_bdev->ch = NULL;

	spdk_bdev_close(gpt_bdev->bdev_desc);

	gpt_bdev->bdev_desc = NULL;

	spdk_bdev_free_io(bdev_io);



	if (status != SPDK_BDEV_IO_STATUS_SUCCESS) {

		SPDK_ERRLOG("Gpt: bdev=%s io error status=%d\n",

			    spdk_bdev_get_name(gpt_bdev->bdev), status);

			    spdk_bdev_get_name(bdev), status);

		goto end;

	}
@@ -442,10 +445,17 @@ spdk_gpt_bdev_complete(struct spdk_bdev_io *bdev_io, bool status, void *arg) 
		goto end;

	}



	rc = spdk_vbdev_module_claim_bdev(bdev, NULL, SPDK_GET_BDEV_MODULE(gpt));

	if (rc) {

		SPDK_ERRLOG("could not claim bdev %s\n", spdk_bdev_get_name(bdev));

		goto end;

	}



	claimed = true;

	rc = vbdev_gpt_create_bdevs(gpt_bdev);

	if (rc < 0) {

		SPDK_TRACELOG(SPDK_TRACE_VBDEV_GPT, "Failed to split dev=%s by gpt table\n",

			      spdk_bdev_get_name(gpt_bdev->bdev));

			      spdk_bdev_get_name(bdev));

	}



end:
@@ -455,10 +465,12 @@ end: 
	 */

	spdk_vbdev_module_examine_done(SPDK_GET_BDEV_MODULE(gpt));



	spdk_bdev_free_io(bdev_io);

	if (gpt_bdev->ref == 0) {

		/* If no gpt_partition_disk instances were created, free the base context */

		spdk_gpt_bdev_free(gpt_bdev);

		if (claimed) {

			spdk_vbdev_module_release_bdev(bdev);

		}

	}

}

lib/bdev/rpc/bdev_rpc.c

+0 −3
Original line number Diff line number Diff line
@@ -74,9 +74,6 @@ spdk_rpc_get_bdevs(struct spdk_jsonrpc_request *request, 
		spdk_json_write_name(w, "bdev_opened_for_write");

		spdk_json_write_bool(w, bdev->bdev_opened_for_write);



		spdk_json_write_name(w, "vbdevs_opened_for_write");

		spdk_json_write_uint32(w, bdev->vbdevs_opened_for_write);



		spdk_json_write_name(w, "driver_specific");

		spdk_json_write_object_begin(w);

		spdk_bdev_dump_config_json(bdev, w);