Commit 249a68e9 authored by Daniel Verkamp's avatar Daniel Verkamp
Browse files

bdev: add API to claim block devices 



Claim the block devices used by iSCSI LUNs and NVMe-oF subsystems so
they can't accidentally be reused.

This will also be used by virtual block devices to allow layering of
bdevs.

Change-Id: I5384923fbf24f13f4ce720a797c5a628053d49f4
Signed-off-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent 143692d1

include/spdk/bdev.h

+26 −0
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 
#include <stddef.h>  /* for offsetof */

#include <sys/uio.h> /* for struct iovec */

#include <stdbool.h>

#include <pthread.h>



#include "spdk/event.h"

#include "spdk/queue.h"
@@ -100,6 +101,9 @@ struct spdk_bdev { 
	/** generation value used by block device reset */

	uint32_t gencnt;



	/** Mutex protecting claimed */

	pthread_mutex_t mutex;



	/** True if another blockdev or a LUN is using this device */

	bool claimed;
@@ -285,6 +289,28 @@ void spdk_bdev_unregister(struct spdk_bdev *bdev); 
struct spdk_bdev *spdk_bdev_first(void);

struct spdk_bdev *spdk_bdev_next(struct spdk_bdev *prev);



/**

 * Claim ownership of a block device.

 *

 * User applications and virtual blockdevs may use this to mediate access to bdevs.

 *

 * When the ownership of the bdev is no longer needed, the user should call spdk_bdev_unclaim().

 *

 * \param bdev Block device to claim.

 * \return true if the caller claimed the bdev, or false if it was already claimed by another user.

 */

bool spdk_bdev_claim(struct spdk_bdev *bdev);



/**

 * Release claim of ownership of a block device.

 *

 * When a bdev reference acquired with spdk_bdev_claim() is no longer needed, the user should

 * release the claim using spdk_bdev_unclaim().

 *

 * \param bdev Block device to release.

 */

void spdk_bdev_unclaim(struct spdk_bdev *bdev);



bool spdk_bdev_io_type_supported(struct spdk_bdev *bdev, enum spdk_bdev_io_type io_type);



int spdk_bdev_dump_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w);

lib/bdev/bdev.c

+37 −0
Original line number Diff line number Diff line
@@ -854,6 +854,9 @@ spdk_bdev_register(struct spdk_bdev *bdev) 
	/* initialize the reset generation value to zero */

	bdev->gencnt = 0;



	pthread_mutex_init(&bdev->mutex, NULL);

	bdev->claimed = false;



	SPDK_TRACELOG(SPDK_TRACE_DEBUG, "Inserting bdev %s into list\n", bdev->name);

	TAILQ_INSERT_TAIL(&spdk_bdev_list, bdev, link);

}
@@ -866,12 +869,46 @@ spdk_bdev_unregister(struct spdk_bdev *bdev) 
	SPDK_TRACELOG(SPDK_TRACE_DEBUG, "Removing bdev %s from list\n", bdev->name);

	TAILQ_REMOVE(&spdk_bdev_list, bdev, link);



	pthread_mutex_destroy(&bdev->mutex);



	rc = bdev->fn_table->destruct(bdev->ctxt);

	if (rc < 0) {

		SPDK_ERRLOG("destruct failed\n");

	}

}



bool

spdk_bdev_claim(struct spdk_bdev *bdev)

{

	bool success;



	pthread_mutex_lock(&bdev->mutex);



	if (!bdev->claimed) {

		/* Take ownership of bdev. */

		bdev->claimed = true;

		success = true;

	} else {

		/* bdev is already claimed. */

		success = false;

	}



	pthread_mutex_unlock(&bdev->mutex);



	return success;

}



void

spdk_bdev_unclaim(struct spdk_bdev *bdev)

{

	pthread_mutex_lock(&bdev->mutex);



	assert(bdev->claimed);

	bdev->claimed = false;



	pthread_mutex_unlock(&bdev->mutex);

}



void

spdk_bdev_io_get_rbuf(struct spdk_bdev_io *bdev_io, spdk_bdev_io_get_rbuf_cb cb)

{

lib/nvmf/subsystem.c

+7 −0
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 
#include "spdk/trace.h"

#include "spdk/nvmf_spec.h"



#include "spdk_internal/bdev.h"

#include "spdk_internal/log.h"



static TAILQ_HEAD(, spdk_nvmf_subsystem) g_subsystems = TAILQ_HEAD_INITIALIZER(g_subsystems);
@@ -420,6 +421,12 @@ spdk_nvmf_subsystem_add_ns(struct spdk_nvmf_subsystem *subsystem, struct spdk_bd 
{

	int i = 0;



	if (!spdk_bdev_claim(bdev)) {

		SPDK_ERRLOG("Subsystem %s: bdev %s is already claimed\n",

			    subsystem->subnqn, bdev->name);

		return -1;

	}



	assert(subsystem->mode == NVMF_SUBSYSTEM_MODE_VIRTUAL);

	while (i < MAX_VIRTUAL_NAMESPACE && subsystem->dev.virt.ns_list[i]) {

		i++;

lib/nvmf/virtual.c

+5 −1
Original line number Diff line number Diff line
@@ -534,7 +534,11 @@ nvmf_virtual_ctrlr_process_io_cmd(struct spdk_nvmf_request *req) 
static void

nvmf_virtual_ctrlr_detach(struct spdk_nvmf_subsystem *subsystem)

{

	return;

	uint32_t i;



	for (i = 0; i < subsystem->dev.virt.ns_count; i++) {

		spdk_bdev_unclaim(subsystem->dev.virt.ns_list[i]);

	}

}



const struct spdk_nvmf_ctrlr_ops spdk_nvmf_virtual_ctrlr_ops = {

lib/scsi/lun.c

+7 −0
Original line number Diff line number Diff line
@@ -289,6 +289,12 @@ spdk_scsi_lun_construct(const char *name, struct spdk_bdev *bdev) 
		return NULL;

	}



	if (!spdk_bdev_claim(bdev)) {

		SPDK_ERRLOG("LUN %s: bdev %s is already claimed\n", name, bdev->name);

		free(lun);

		return NULL;

	}



	TAILQ_INIT(&lun->tasks);

	TAILQ_INIT(&lun->pending_tasks);
@@ -308,6 +314,7 @@ spdk_scsi_lun_construct(const char *name, struct spdk_bdev *bdev) 
static int

spdk_scsi_lun_destruct(struct spdk_scsi_lun *lun)

{

	spdk_bdev_unclaim(lun->bdev);

	spdk_scsi_lun_db_delete(lun);



	free(lun);