Commit f57b098e authored by Seth Howell's avatar Seth Howell Committed by Tomasz Zawadzki
Browse files

bdev_nvme: add synchronization to reset. 



The generic bdev layer currently has a lot of snychronization built into
spdk_bdev_reset. However, in a couple patches I am going to introduce a
few instances where I call bdev_nvme_reset directly from this module.
The reason I call bdev_nvme_reset directly from this module is so that I
don't have to open a descriptor to the bdev in the module itself.

In order to be able to call bdev_nvme_reset from both this module and in
response to a bdev_io, we need to synchronize and queue reset requests.

Change-Id: I7ece41119cba705a7481d365d20a1eb746a80f64
Signed-off-by: default avatarSeth Howell <seth.howell@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/473754


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
parent a4d9919b

module/bdev/nvme/bdev_nvme.c

+59 −7
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ static int bdev_nvme_config_json(struct spdk_json_write_ctx *w); 
struct nvme_io_channel {

	struct spdk_nvme_qpair		*qpair;

	struct spdk_poller		*poller;

	TAILQ_HEAD(, spdk_bdev_io)	pending_resets;



	bool				collect_spin_stat;

	uint64_t			spin_ticks;
@@ -147,6 +148,7 @@ static int bdev_nvme_io_passthru_md(struct nvme_bdev *nbdev, struct spdk_io_chan 
				    struct spdk_nvme_cmd *cmd, void *buf, size_t nbytes, void *md_buf, size_t md_len);

static int nvme_ctrlr_create_bdev(struct nvme_bdev_ctrlr *nvme_bdev_ctrlr,

				  struct nvme_bdev_ns *nvme_ns);

static int bdev_nvme_reset(struct nvme_bdev_ctrlr *nvme_bdev_ctrlr, struct nvme_bdev_io *bio);



struct spdk_nvme_qpair *

spdk_bdev_nvme_get_io_qpair(struct spdk_io_channel *ctrlr_io_ch)
@@ -280,14 +282,47 @@ bdev_nvme_flush(struct nvme_bdev *nbdev, struct nvme_bdev_io *bio, 
	return 0;

}



static void

_bdev_nvme_complete_pending_resets(struct spdk_io_channel_iter *i)

{

	struct spdk_io_channel *_ch = spdk_io_channel_iter_get_channel(i);

	struct nvme_io_channel *nvme_ch = spdk_io_channel_get_ctx(_ch);

	struct spdk_bdev_io *bdev_io;

	enum spdk_bdev_io_status status = SPDK_BDEV_IO_STATUS_SUCCESS;



	/* A NULL ctx means success. */

	if (spdk_io_channel_iter_get_ctx(i) != NULL) {

		status = SPDK_BDEV_IO_STATUS_FAILED;

	}



	while (!TAILQ_EMPTY(&nvme_ch->pending_resets)) {

		bdev_io = TAILQ_FIRST(&nvme_ch->pending_resets);

		TAILQ_REMOVE(&nvme_ch->pending_resets, bdev_io, module_link);

		spdk_bdev_io_complete(bdev_io, status);

	}



	spdk_for_each_channel_continue(i, 0);

}



static void

_bdev_nvme_reset_complete(struct nvme_bdev_ctrlr *nvme_bdev_ctrlr, int rc)

{

	/* we are using the for_each_channel cb_arg like a return code here. */

	/* If it's zero, we succeeded, otherwise, the reset failed. */

	void *cb_arg = NULL;



	if (rc) {

		cb_arg = (void *)0x1;

		SPDK_ERRLOG("Resetting controller failed.\n");

	} else {

		SPDK_NOTICELOG("Resetting controller successful.\n");

	}



	__atomic_clear(&nvme_bdev_ctrlr->resetting, __ATOMIC_RELAXED);

	/* Make sure we clear any pending resets before returning. */

	spdk_for_each_channel(nvme_bdev_ctrlr,

			      _bdev_nvme_complete_pending_resets,

			      cb_arg, NULL);

}



static void
@@ -377,6 +412,21 @@ _bdev_nvme_reset_destroy_qpair(struct spdk_io_channel_iter *i) 
static int

bdev_nvme_reset(struct nvme_bdev_ctrlr *nvme_bdev_ctrlr, struct nvme_bdev_io *bio)

{

	struct spdk_io_channel *ch;

	struct nvme_io_channel *nvme_ch;



	if (__atomic_test_and_set(&nvme_bdev_ctrlr->resetting, __ATOMIC_RELAXED)) {

		SPDK_NOTICELOG("Unable to perform reset, already in progress.\n");

		if (bio) {

			ch = spdk_get_io_channel(nvme_bdev_ctrlr);

			assert(ch != NULL);

			nvme_ch = spdk_io_channel_get_ctx(ch);

			TAILQ_INSERT_TAIL(&nvme_ch->pending_resets, spdk_bdev_io_from_ctx(bio), module_link);

			spdk_put_io_channel(ch);

		}

		return 0;

	}



	/* First, delete all NVMe I/O queue pairs. */

	spdk_for_each_channel(nvme_bdev_ctrlr,

			      _bdev_nvme_reset_destroy_qpair,
@@ -588,6 +638,8 @@ bdev_nvme_create_cb(void *io_device, void *ctx_buf) 
	}



	ch->poller = spdk_poller_register(bdev_nvme_poll, ch, g_opts.nvme_ioq_poll_period_us);



	TAILQ_INIT(&ch->pending_resets);

	return 0;

}

module/bdev/nvme/common.h

+1 −0
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ struct nvme_bdev_ctrlr { 
	struct spdk_nvme_transport_id	trid;

	char				*name;

	int				ref;

	bool				resetting;

	bool				destruct;

	/**

	 * PI check flags. This flags is set to NVMe controllers created only