1 files changed, 1115 insertions, 0 deletions

diff --git a/src/spdk/lib/nvme/nvme_cuse.c b/src/spdk/lib/nvme/nvme_cuse.c
new file mode 100644
index 000000000..9a5ee1f0d
--- /dev/null
+++ b/src/spdk/lib/nvme/nvme_cuse.c
@@ -0,0 +1,1115 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright (c) Intel Corporation.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define FUSE_USE_VERSION 31
+
+#include <fuse3/cuse_lowlevel.h>
+
+#include <linux/nvme_ioctl.h>
+#include <linux/fs.h>
+
+#include "nvme_internal.h"
+#include "nvme_io_msg.h"
+#include "nvme_cuse.h"
+
+struct cuse_device {
+	bool				is_started;
+
+	char				dev_name[128];
+	uint32_t			index;
+	int				claim_fd;
+	char				lock_name[64];
+
+	struct spdk_nvme_ctrlr		*ctrlr;		/**< NVMe controller */
+	uint32_t			nsid;		/**< NVMe name space id, or 0 */
+
+	pthread_t			tid;
+	struct fuse_session		*session;
+
+	struct cuse_device		*ctrlr_device;
+	struct cuse_device		*ns_devices;	/**< Array of cuse ns devices */
+
+	TAILQ_ENTRY(cuse_device)	tailq;
+};
+
+static pthread_mutex_t g_cuse_mtx = PTHREAD_MUTEX_INITIALIZER;
+static TAILQ_HEAD(, cuse_device) g_ctrlr_ctx_head = TAILQ_HEAD_INITIALIZER(g_ctrlr_ctx_head);
+static struct spdk_bit_array *g_ctrlr_started;
+
+struct cuse_io_ctx {
+	struct spdk_nvme_cmd		nvme_cmd;
+	enum spdk_nvme_data_transfer	data_transfer;
+
+	uint64_t			lba;
+	uint32_t			lba_count;
+
+	void				*data;
+	int				data_len;
+
+	fuse_req_t			req;
+};
+
+static void
+cuse_io_ctx_free(struct cuse_io_ctx *ctx)
+{
+	spdk_free(ctx->data);
+	free(ctx);
+}
+
+#define FUSE_REPLY_CHECK_BUFFER(req, arg, out_bufsz, val)		\
+	if (out_bufsz == 0) {						\
+		struct iovec out_iov;					\
+		out_iov.iov_base = (void *)arg;				\
+		out_iov.iov_len = sizeof(val);				\
+		fuse_reply_ioctl_retry(req, NULL, 0, &out_iov, 1);	\
+		return;							\
+	}
+
+static void
+cuse_nvme_admin_cmd_cb(void *arg, const struct spdk_nvme_cpl *cpl)
+{
+	struct cuse_io_ctx *ctx = arg;
+	struct iovec out_iov[2];
+	struct spdk_nvme_cpl _cpl;
+
+	if (ctx->data_transfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
+		fuse_reply_ioctl_iov(ctx->req, cpl->status.sc, NULL, 0);
+	} else {
+		memcpy(&_cpl, cpl, sizeof(struct spdk_nvme_cpl));
+
+		out_iov[0].iov_base = &_cpl.cdw0;
+		out_iov[0].iov_len = sizeof(_cpl.cdw0);
+
+		if (ctx->data_len > 0) {
+			out_iov[1].iov_base = ctx->data;
+			out_iov[1].iov_len = ctx->data_len;
+			fuse_reply_ioctl_iov(ctx->req, cpl->status.sc, out_iov, 2);
+		} else {
+			fuse_reply_ioctl_iov(ctx->req, cpl->status.sc, out_iov, 1);
+		}
+	}
+
+	cuse_io_ctx_free(ctx);
+}
+
+static void
+cuse_nvme_admin_cmd_execute(struct spdk_nvme_ctrlr *ctrlr, uint32_t nsid, void *arg)
+{
+	int rc;
+	struct cuse_io_ctx *ctx = arg;
+
+	rc = spdk_nvme_ctrlr_cmd_admin_raw(ctrlr, &ctx->nvme_cmd, ctx->data, ctx->data_len,
+					   cuse_nvme_admin_cmd_cb, (void *)ctx);
+	if (rc < 0) {
+		fuse_reply_err(ctx->req, EINVAL);
+		cuse_io_ctx_free(ctx);
+	}
+}
+
+static void
+cuse_nvme_admin_cmd_send(fuse_req_t req, struct nvme_admin_cmd *admin_cmd,
+			 const void *data)
+{
+	struct cuse_io_ctx *ctx;
+	struct cuse_device *cuse_device = fuse_req_userdata(req);
+	int rv;
+
+	ctx = (struct cuse_io_ctx *)calloc(1, sizeof(struct cuse_io_ctx));
+	if (!ctx) {
+		SPDK_ERRLOG("Cannot allocate memory for cuse_io_ctx\n");
+		fuse_reply_err(req, ENOMEM);
+		return;
+	}
+
+	ctx->req = req;
+	ctx->data_transfer = spdk_nvme_opc_get_data_transfer(admin_cmd->opcode);
+
+	memset(&ctx->nvme_cmd, 0, sizeof(ctx->nvme_cmd));
+	ctx->nvme_cmd.opc = admin_cmd->opcode;
+	ctx->nvme_cmd.nsid = admin_cmd->nsid;
+	ctx->nvme_cmd.cdw10 = admin_cmd->cdw10;
+	ctx->nvme_cmd.cdw11 = admin_cmd->cdw11;
+	ctx->nvme_cmd.cdw12 = admin_cmd->cdw12;
+	ctx->nvme_cmd.cdw13 = admin_cmd->cdw13;
+	ctx->nvme_cmd.cdw14 = admin_cmd->cdw14;
+	ctx->nvme_cmd.cdw15 = admin_cmd->cdw15;
+
+	ctx->data_len = admin_cmd->data_len;
+
+	if (ctx->data_len > 0) {
+		ctx->data = spdk_malloc(ctx->data_len, 0, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
+		if (!ctx->data) {
+			SPDK_ERRLOG("Cannot allocate memory for data\n");
+			fuse_reply_err(req, ENOMEM);
+			free(ctx);
+			return;
+		}
+		if (data != NULL) {
+			memcpy(ctx->data, data, ctx->data_len);
+		}
+	}
+
+	rv = nvme_io_msg_send(cuse_device->ctrlr, 0, cuse_nvme_admin_cmd_execute, ctx);
+	if (rv) {
+		SPDK_ERRLOG("Cannot send io msg to the controller\n");
+		fuse_reply_err(req, -rv);
+		cuse_io_ctx_free(ctx);
+		return;
+	}
+}
+
+static void
+cuse_nvme_admin_cmd(fuse_req_t req, int cmd, void *arg,
+		    struct fuse_file_info *fi, unsigned flags,
+		    const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	struct nvme_admin_cmd *admin_cmd;
+	struct iovec in_iov[2], out_iov[2];
+
+	in_iov[0].iov_base = (void *)arg;
+	in_iov[0].iov_len = sizeof(*admin_cmd);
+	if (in_bufsz == 0) {
+		fuse_reply_ioctl_retry(req, in_iov, 1, NULL, 0);
+		return;
+	}
+
+	admin_cmd = (struct nvme_admin_cmd *)in_buf;
+
+	switch (spdk_nvme_opc_get_data_transfer(admin_cmd->opcode)) {
+	case SPDK_NVME_DATA_NONE:
+		SPDK_ERRLOG("SPDK_NVME_DATA_NONE not implemented\n");
+		fuse_reply_err(req, EINVAL);
+		return;
+	case SPDK_NVME_DATA_HOST_TO_CONTROLLER:
+		if (admin_cmd->addr != 0) {
+			in_iov[1].iov_base = (void *)admin_cmd->addr;
+			in_iov[1].iov_len = admin_cmd->data_len;
+			if (in_bufsz == sizeof(*admin_cmd)) {
+				fuse_reply_ioctl_retry(req, in_iov, 2, NULL, 0);
+				return;
+			}
+			cuse_nvme_admin_cmd_send(req, admin_cmd, in_buf + sizeof(*admin_cmd));
+		} else {
+			cuse_nvme_admin_cmd_send(req, admin_cmd, NULL);
+		}
+		return;
+	case SPDK_NVME_DATA_CONTROLLER_TO_HOST:
+		if (out_bufsz == 0) {
+			out_iov[0].iov_base = &((struct nvme_admin_cmd *)arg)->result;
+			out_iov[0].iov_len = sizeof(uint32_t);
+			if (admin_cmd->data_len > 0) {
+				out_iov[1].iov_base = (void *)admin_cmd->addr;
+				out_iov[1].iov_len = admin_cmd->data_len;
+				fuse_reply_ioctl_retry(req, in_iov, 1, out_iov, 2);
+			} else {
+				fuse_reply_ioctl_retry(req, in_iov, 1, out_iov, 1);
+			}
+			return;
+		}
+
+		cuse_nvme_admin_cmd_send(req, admin_cmd, NULL);
+
+		return;
+	case SPDK_NVME_DATA_BIDIRECTIONAL:
+		fuse_reply_err(req, EINVAL);
+		return;
+	}
+}
+
+static void
+cuse_nvme_reset_execute(struct spdk_nvme_ctrlr *ctrlr, uint32_t nsid, void *arg)
+{
+	int rc;
+	fuse_req_t req = arg;
+
+	rc = spdk_nvme_ctrlr_reset(ctrlr);
+	if (rc) {
+		fuse_reply_err(req, rc);
+		return;
+	}
+
+	fuse_reply_ioctl_iov(req, 0, NULL, 0);
+}
+
+static void
+cuse_nvme_reset(fuse_req_t req, int cmd, void *arg,
+		struct fuse_file_info *fi, unsigned flags,
+		const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	int rv;
+	struct cuse_device *cuse_device = fuse_req_userdata(req);
+
+	if (cuse_device->nsid) {
+		SPDK_ERRLOG("Namespace reset not supported\n");
+		fuse_reply_err(req, EINVAL);
+		return;
+	}
+
+	rv = nvme_io_msg_send(cuse_device->ctrlr, cuse_device->nsid, cuse_nvme_reset_execute, (void *)req);
+	if (rv) {
+		SPDK_ERRLOG("Cannot send reset\n");
+		fuse_reply_err(req, EINVAL);
+	}
+}
+
+/*****************************************************************************
+ * Namespace IO requests
+ */
+
+static void
+cuse_nvme_submit_io_write_done(void *ref, const struct spdk_nvme_cpl *cpl)
+{
+	struct cuse_io_ctx *ctx = (struct cuse_io_ctx *)ref;
+
+	fuse_reply_ioctl_iov(ctx->req, cpl->status.sc, NULL, 0);
+
+	cuse_io_ctx_free(ctx);
+}
+
+static void
+cuse_nvme_submit_io_write_cb(struct spdk_nvme_ctrlr *ctrlr, uint32_t nsid, void *arg)
+{
+	int rc;
+	struct cuse_io_ctx *ctx = arg;
+	struct spdk_nvme_ns *ns = spdk_nvme_ctrlr_get_ns(ctrlr, nsid);
+
+	rc = spdk_nvme_ns_cmd_write(ns, ctrlr->external_io_msgs_qpair, ctx->data,
+				    ctx->lba, /* LBA start */
+				    ctx->lba_count, /* number of LBAs */
+				    cuse_nvme_submit_io_write_done, ctx, 0);
+
+	if (rc != 0) {
+		SPDK_ERRLOG("write failed: rc = %d\n", rc);
+		fuse_reply_err(ctx->req, rc);
+		cuse_io_ctx_free(ctx);
+		return;
+	}
+}
+
+static void
+cuse_nvme_submit_io_write(fuse_req_t req, int cmd, void *arg,
+			  struct fuse_file_info *fi, unsigned flags,
+			  const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	const struct nvme_user_io *user_io = in_buf;
+	struct cuse_io_ctx *ctx;
+	struct spdk_nvme_ns *ns;
+	uint32_t block_size;
+	int rc;
+	struct cuse_device *cuse_device = fuse_req_userdata(req);
+
+	ctx = (struct cuse_io_ctx *)calloc(1, sizeof(struct cuse_io_ctx));
+	if (!ctx) {
+		SPDK_ERRLOG("Cannot allocate memory for context\n");
+		fuse_reply_err(req, ENOMEM);
+		return;
+	}
+
+	ctx->req = req;
+
+	ns = spdk_nvme_ctrlr_get_ns(cuse_device->ctrlr, cuse_device->nsid);
+	block_size = spdk_nvme_ns_get_sector_size(ns);
+
+	ctx->lba = user_io->slba;
+	ctx->lba_count = user_io->nblocks + 1;
+	ctx->data_len = ctx->lba_count * block_size;
+
+	ctx->data = spdk_zmalloc(ctx->data_len, 0x1000, NULL, SPDK_ENV_SOCKET_ID_ANY,
+				 SPDK_MALLOC_DMA);
+	if (ctx->data == NULL) {
+		SPDK_ERRLOG("Write buffer allocation failed\n");
+		fuse_reply_err(ctx->req, ENOMEM);
+		free(ctx);
+		return;
+	}
+
+	memcpy(ctx->data, in_buf + sizeof(*user_io), ctx->data_len);
+
+	rc = nvme_io_msg_send(cuse_device->ctrlr, cuse_device->nsid, cuse_nvme_submit_io_write_cb,
+			      ctx);
+	if (rc < 0) {
+		SPDK_ERRLOG("Cannot send write io\n");
+		fuse_reply_err(ctx->req, rc);
+		cuse_io_ctx_free(ctx);
+	}
+}
+
+static void
+cuse_nvme_submit_io_read_done(void *ref, const struct spdk_nvme_cpl *cpl)
+{
+	struct cuse_io_ctx *ctx = (struct cuse_io_ctx *)ref;
+	struct iovec iov;
+
+	iov.iov_base = ctx->data;
+	iov.iov_len = ctx->data_len;
+
+	fuse_reply_ioctl_iov(ctx->req, cpl->status.sc, &iov, 1);
+
+	cuse_io_ctx_free(ctx);
+}
+
+static void
+cuse_nvme_submit_io_read_cb(struct spdk_nvme_ctrlr *ctrlr, uint32_t nsid, void *arg)
+{
+	int rc;
+	struct cuse_io_ctx *ctx = arg;
+	struct spdk_nvme_ns *ns = spdk_nvme_ctrlr_get_ns(ctrlr, nsid);
+
+	rc = spdk_nvme_ns_cmd_read(ns, ctrlr->external_io_msgs_qpair, ctx->data,
+				   ctx->lba, /* LBA start */
+				   ctx->lba_count, /* number of LBAs */
+				   cuse_nvme_submit_io_read_done, ctx, 0);
+
+	if (rc != 0) {
+		SPDK_ERRLOG("read failed: rc = %d\n", rc);
+		fuse_reply_err(ctx->req, rc);
+		cuse_io_ctx_free(ctx);
+		return;
+	}
+}
+
+static void
+cuse_nvme_submit_io_read(fuse_req_t req, int cmd, void *arg,
+			 struct fuse_file_info *fi, unsigned flags,
+			 const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	int rc;
+	struct cuse_io_ctx *ctx;
+	const struct nvme_user_io *user_io = in_buf;
+	struct cuse_device *cuse_device = fuse_req_userdata(req);
+	struct spdk_nvme_ns *ns;
+	uint32_t block_size;
+
+	ctx = (struct cuse_io_ctx *)calloc(1, sizeof(struct cuse_io_ctx));
+	if (!ctx) {
+		SPDK_ERRLOG("Cannot allocate memory for context\n");
+		fuse_reply_err(req, ENOMEM);
+		return;
+	}
+
+	ctx->req = req;
+	ctx->lba = user_io->slba;
+	ctx->lba_count = user_io->nblocks;
+
+	ns = spdk_nvme_ctrlr_get_ns(cuse_device->ctrlr, cuse_device->nsid);
+	block_size = spdk_nvme_ns_get_sector_size(ns);
+
+	ctx->data_len = ctx->lba_count * block_size;
+	ctx->data = spdk_zmalloc(ctx->data_len, 0x1000, NULL, SPDK_ENV_SOCKET_ID_ANY,
+				 SPDK_MALLOC_DMA);
+	if (ctx->data == NULL) {
+		SPDK_ERRLOG("Read buffer allocation failed\n");
+		fuse_reply_err(ctx->req, ENOMEM);
+		free(ctx);
+		return;
+	}
+
+	rc = nvme_io_msg_send(cuse_device->ctrlr, cuse_device->nsid, cuse_nvme_submit_io_read_cb, ctx);
+	if (rc < 0) {
+		SPDK_ERRLOG("Cannot send read io\n");
+		fuse_reply_err(ctx->req, rc);
+		cuse_io_ctx_free(ctx);
+	}
+}
+
+
+static void
+cuse_nvme_submit_io(fuse_req_t req, int cmd, void *arg,
+		    struct fuse_file_info *fi, unsigned flags,
+		    const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	const struct nvme_user_io *user_io;
+	struct iovec in_iov[2], out_iov;
+
+	in_iov[0].iov_base = (void *)arg;
+	in_iov[0].iov_len = sizeof(*user_io);
+	if (in_bufsz == 0) {
+		fuse_reply_ioctl_retry(req, in_iov, 1, NULL, 0);
+		return;
+	}
+
+	user_io = in_buf;
+
+	switch (user_io->opcode) {
+	case SPDK_NVME_OPC_READ:
+		out_iov.iov_base = (void *)user_io->addr;
+		out_iov.iov_len = (user_io->nblocks + 1) * 512;
+		if (out_bufsz == 0) {
+			fuse_reply_ioctl_retry(req, in_iov, 1, &out_iov, 1);
+			return;
+		}
+
+		cuse_nvme_submit_io_read(req, cmd, arg, fi, flags, in_buf,
+					 in_bufsz, out_bufsz);
+		break;
+	case SPDK_NVME_OPC_WRITE:
+		in_iov[1].iov_base = (void *)user_io->addr;
+		in_iov[1].iov_len = (user_io->nblocks + 1) * 512;
+		if (in_bufsz == sizeof(*user_io)) {
+			fuse_reply_ioctl_retry(req, in_iov, 2, NULL, 0);
+			return;
+		}
+
+		cuse_nvme_submit_io_write(req, cmd, arg, fi, flags, in_buf,
+					  in_bufsz, out_bufsz);
+
+		break;
+	default:
+		SPDK_ERRLOG("SUBMIT_IO: opc:%d not valid\n", user_io->opcode);
+		fuse_reply_err(req, EINVAL);
+		return;
+	}
+
+}
+
+/*****************************************************************************
+ * Other namespace IOCTLs
+ */
+static void
+cuse_blkgetsize64(fuse_req_t req, int cmd, void *arg,
+		  struct fuse_file_info *fi, unsigned flags,
+		  const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	uint64_t size;
+	struct spdk_nvme_ns *ns;
+	struct cuse_device *cuse_device = fuse_req_userdata(req);
+
+	FUSE_REPLY_CHECK_BUFFER(req, arg, out_bufsz, size);
+
+	ns = spdk_nvme_ctrlr_get_ns(cuse_device->ctrlr, cuse_device->nsid);
+	size = spdk_nvme_ns_get_num_sectors(ns);
+	fuse_reply_ioctl(req, 0, &size, sizeof(size));
+}
+
+static void
+cuse_blkpbszget(fuse_req_t req, int cmd, void *arg,
+		struct fuse_file_info *fi, unsigned flags,
+		const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	int pbsz;
+	struct spdk_nvme_ns *ns;
+	struct cuse_device *cuse_device = fuse_req_userdata(req);
+
+	FUSE_REPLY_CHECK_BUFFER(req, arg, out_bufsz, pbsz);
+
+	ns = spdk_nvme_ctrlr_get_ns(cuse_device->ctrlr, cuse_device->nsid);
+	pbsz = spdk_nvme_ns_get_sector_size(ns);
+	fuse_reply_ioctl(req, 0, &pbsz, sizeof(pbsz));
+}
+
+static void
+cuse_blkgetsize(fuse_req_t req, int cmd, void *arg,
+		struct fuse_file_info *fi, unsigned flags,
+		const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	long size;
+	struct spdk_nvme_ns *ns;
+	struct cuse_device *cuse_device = fuse_req_userdata(req);
+
+	FUSE_REPLY_CHECK_BUFFER(req, arg, out_bufsz, size);
+
+	ns = spdk_nvme_ctrlr_get_ns(cuse_device->ctrlr, cuse_device->nsid);
+
+	/* return size in 512 bytes blocks */
+	size = spdk_nvme_ns_get_num_sectors(ns) * 512 / spdk_nvme_ns_get_sector_size(ns);
+	fuse_reply_ioctl(req, 0, &size, sizeof(size));
+}
+
+static void
+cuse_getid(fuse_req_t req, int cmd, void *arg,
+	   struct fuse_file_info *fi, unsigned flags,
+	   const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	struct cuse_device *cuse_device = fuse_req_userdata(req);
+
+	fuse_reply_ioctl(req, cuse_device->nsid, NULL, 0);
+}
+
+static void
+cuse_ctrlr_ioctl(fuse_req_t req, int cmd, void *arg,
+		 struct fuse_file_info *fi, unsigned flags,
+		 const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	if (flags & FUSE_IOCTL_COMPAT) {
+		fuse_reply_err(req, ENOSYS);
+		return;
+	}
+
+	switch (cmd) {
+	case NVME_IOCTL_ADMIN_CMD:
+		cuse_nvme_admin_cmd(req, cmd, arg, fi, flags, in_buf, in_bufsz, out_bufsz);
+		break;
+
+	case NVME_IOCTL_RESET:
+		cuse_nvme_reset(req, cmd, arg, fi, flags, in_buf, in_bufsz, out_bufsz);
+		break;
+
+	default:
+		SPDK_ERRLOG("Unsupported IOCTL 0x%X.\n", cmd);
+		fuse_reply_err(req, EINVAL);
+	}
+}
+
+static void
+cuse_ns_ioctl(fuse_req_t req, int cmd, void *arg,
+	      struct fuse_file_info *fi, unsigned flags,
+	      const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	if (flags & FUSE_IOCTL_COMPAT) {
+		fuse_reply_err(req, ENOSYS);
+		return;
+	}
+
+	switch (cmd) {
+	case NVME_IOCTL_ADMIN_CMD:
+		cuse_nvme_admin_cmd(req, cmd, arg, fi, flags, in_buf, in_bufsz, out_bufsz);
+		break;
+
+	case NVME_IOCTL_SUBMIT_IO:
+		cuse_nvme_submit_io(req, cmd, arg, fi, flags, in_buf, in_bufsz, out_bufsz);
+		break;
+
+	case NVME_IOCTL_ID:
+		cuse_getid(req, cmd, arg, fi, flags, in_buf, in_bufsz, out_bufsz);
+		break;
+
+	case BLKPBSZGET:
+		cuse_blkpbszget(req, cmd, arg, fi, flags, in_buf, in_bufsz, out_bufsz);
+		break;
+
+	case BLKGETSIZE:
+		/* Returns the device size as a number of 512-byte blocks (returns pointer to long) */
+		cuse_blkgetsize(req, cmd, arg, fi, flags, in_buf, in_bufsz, out_bufsz);
+		break;
+
+	case BLKGETSIZE64:
+		/* Returns the device size in sectors (returns pointer to uint64_t) */
+		cuse_blkgetsize64(req, cmd, arg, fi, flags, in_buf, in_bufsz, out_bufsz);
+		break;
+
+	default:
+		SPDK_ERRLOG("Unsupported IOCTL 0x%X.\n", cmd);
+		fuse_reply_err(req, EINVAL);
+	}
+}
+
+/*****************************************************************************
+ * CUSE threads initialization.
+ */
+
+static void cuse_open(fuse_req_t req, struct fuse_file_info *fi)
+{
+	fuse_reply_open(req, fi);
+}
+
+static const struct cuse_lowlevel_ops cuse_ctrlr_clop = {
+	.open		= cuse_open,
+	.ioctl		= cuse_ctrlr_ioctl,
+};
+
+static const struct cuse_lowlevel_ops cuse_ns_clop = {
+	.open		= cuse_open,
+	.ioctl		= cuse_ns_ioctl,
+};
+
+static void *
+cuse_thread(void *arg)
+{
+	struct cuse_device *cuse_device = arg;
+	char *cuse_argv[] = { "cuse", "-f" };
+	int cuse_argc = SPDK_COUNTOF(cuse_argv);
+	char devname_arg[128 + 8];
+	const char *dev_info_argv[] = { devname_arg };
+	struct cuse_info ci;
+	int multithreaded;
+	int rc;
+	struct fuse_buf buf = { .mem = NULL };
+	struct pollfd fds;
+	int timeout_msecs = 500;
+
+	spdk_unaffinitize_thread();
+
+	snprintf(devname_arg, sizeof(devname_arg), "DEVNAME=%s", cuse_device->dev_name);
+
+	memset(&ci, 0, sizeof(ci));
+	ci.dev_info_argc = 1;
+	ci.dev_info_argv = dev_info_argv;
+	ci.flags = CUSE_UNRESTRICTED_IOCTL;
+
+	if (cuse_device->nsid) {
+		cuse_device->session = cuse_lowlevel_setup(cuse_argc, cuse_argv, &ci, &cuse_ns_clop,
+				       &multithreaded, cuse_device);
+	} else {
+		cuse_device->session = cuse_lowlevel_setup(cuse_argc, cuse_argv, &ci, &cuse_ctrlr_clop,
+				       &multithreaded, cuse_device);
+	}
+	if (!cuse_device->session) {
+		SPDK_ERRLOG("Cannot create cuse session\n");
+		goto err;
+	}
+
+	SPDK_NOTICELOG("fuse session for device %s created\n", cuse_device->dev_name);
+
+	/* Receive and process fuse requests */
+	fds.fd = fuse_session_fd(cuse_device->session);
+	fds.events = POLLIN;
+	while (!fuse_session_exited(cuse_device->session)) {
+		rc = poll(&fds, 1, timeout_msecs);
+		if (rc <= 0) {
+			continue;
+		}
+		rc = fuse_session_receive_buf(cuse_device->session, &buf);
+		if (rc > 0) {
+			fuse_session_process_buf(cuse_device->session, &buf);
+		}
+	}
+	free(buf.mem);
+	fuse_session_reset(cuse_device->session);
+	cuse_lowlevel_teardown(cuse_device->session);
+err:
+	pthread_exit(NULL);
+}
+
+/*****************************************************************************
+ * CUSE devices management
+ */
+
+static int
+cuse_nvme_ns_start(struct cuse_device *ctrlr_device, uint32_t nsid)
+{
+	struct cuse_device *ns_device;
+	int rv;
+
+	ns_device = &ctrlr_device->ns_devices[nsid - 1];
+	if (ns_device->is_started) {
+		return 0;
+	}
+
+	ns_device->ctrlr = ctrlr_device->ctrlr;
+	ns_device->ctrlr_device = ctrlr_device;
+	ns_device->nsid = nsid;
+	rv = snprintf(ns_device->dev_name, sizeof(ns_device->dev_name), "%sn%d",
+		      ctrlr_device->dev_name, ns_device->nsid);
+	if (rv < 0) {
+		SPDK_ERRLOG("Device name too long.\n");
+		free(ns_device);
+		return -ENAMETOOLONG;
+	}
+
+	rv = pthread_create(&ns_device->tid, NULL, cuse_thread, ns_device);
+	if (rv != 0) {
+		SPDK_ERRLOG("pthread_create failed\n");
+		return -rv;
+	}
+
+	ns_device->is_started = true;
+
+	return 0;
+}
+
+static void
+cuse_nvme_ns_stop(struct cuse_device *ctrlr_device, uint32_t nsid)
+{
+	struct cuse_device *ns_device;
+
+	ns_device = &ctrlr_device->ns_devices[nsid - 1];
+	if (!ns_device->is_started) {
+		return;
+	}
+
+	fuse_session_exit(ns_device->session);
+	pthread_join(ns_device->tid, NULL);
+	ns_device->is_started = false;
+}
+
+static int
+nvme_cuse_claim(struct cuse_device *ctrlr_device, uint32_t index)
+{
+	int dev_fd;
+	int pid;
+	void *dev_map;
+	struct flock cusedev_lock = {
+		.l_type = F_WRLCK,
+		.l_whence = SEEK_SET,
+		.l_start = 0,
+		.l_len = 0,
+	};
+
+	snprintf(ctrlr_device->lock_name, sizeof(ctrlr_device->lock_name),
+		 "/tmp/spdk_nvme_cuse_lock_%" PRIu32, index);
+
+	dev_fd = open(ctrlr_device->lock_name, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
+	if (dev_fd == -1) {
+		SPDK_ERRLOG("could not open %s\n", ctrlr_device->lock_name);
+		return -errno;
+	}
+
+	if (ftruncate(dev_fd, sizeof(int)) != 0) {
+		SPDK_ERRLOG("could not truncate %s\n", ctrlr_device->lock_name);
+		close(dev_fd);
+		return -errno;
+	}
+
+	dev_map = mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE,
+		       MAP_SHARED, dev_fd, 0);
+	if (dev_map == MAP_FAILED) {
+		SPDK_ERRLOG("could not mmap dev %s (%d)\n", ctrlr_device->lock_name, errno);
+		close(dev_fd);
+		return -errno;
+	}
+
+	if (fcntl(dev_fd, F_SETLK, &cusedev_lock) != 0) {
+		pid = *(int *)dev_map;
+		SPDK_ERRLOG("Cannot create lock on device %s, probably"
+			    " process %d has claimed it\n", ctrlr_device->lock_name, pid);
+		munmap(dev_map, sizeof(int));
+		close(dev_fd);
+		/* F_SETLK returns unspecified errnos, normalize them */
+		return -EACCES;
+	}
+
+	*(int *)dev_map = (int)getpid();
+	munmap(dev_map, sizeof(int));
+	ctrlr_device->claim_fd = dev_fd;
+	ctrlr_device->index = index;
+	/* Keep dev_fd open to maintain the lock. */
+	return 0;
+}
+
+static void
+nvme_cuse_unclaim(struct cuse_device *ctrlr_device)
+{
+	close(ctrlr_device->claim_fd);
+	ctrlr_device->claim_fd = -1;
+	unlink(ctrlr_device->lock_name);
+}
+
+static void
+cuse_nvme_ctrlr_stop(struct cuse_device *ctrlr_device)
+{
+	uint32_t i;
+	uint32_t num_ns = spdk_nvme_ctrlr_get_num_ns(ctrlr_device->ctrlr);
+
+	for (i = 1; i <= num_ns; i++) {
+		cuse_nvme_ns_stop(ctrlr_device, i);
+	}
+
+	fuse_session_exit(ctrlr_device->session);
+	pthread_join(ctrlr_device->tid, NULL);
+	TAILQ_REMOVE(&g_ctrlr_ctx_head, ctrlr_device, tailq);
+	spdk_bit_array_clear(g_ctrlr_started, ctrlr_device->index);
+	if (spdk_bit_array_count_set(g_ctrlr_started) == 0) {
+		spdk_bit_array_free(&g_ctrlr_started);
+	}
+	nvme_cuse_unclaim(ctrlr_device);
+	free(ctrlr_device->ns_devices);
+	free(ctrlr_device);
+}
+
+static int
+cuse_nvme_ctrlr_update_namespaces(struct cuse_device *ctrlr_device)
+{
+	uint32_t nsid;
+	uint32_t num_ns = spdk_nvme_ctrlr_get_num_ns(ctrlr_device->ctrlr);
+
+	for (nsid = 1; nsid <= num_ns; nsid++) {
+		if (!spdk_nvme_ctrlr_is_active_ns(ctrlr_device->ctrlr, nsid)) {
+			cuse_nvme_ns_stop(ctrlr_device, nsid);
+			continue;
+		}
+
+		if (cuse_nvme_ns_start(ctrlr_device, nsid) < 0) {
+			SPDK_ERRLOG("Cannot start CUSE namespace device.");
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static int
+nvme_cuse_start(struct spdk_nvme_ctrlr *ctrlr)
+{
+	int rv = 0;
+	struct cuse_device *ctrlr_device;
+	uint32_t num_ns = spdk_nvme_ctrlr_get_num_ns(ctrlr);
+
+	SPDK_NOTICELOG("Creating cuse device for controller\n");
+
+	if (g_ctrlr_started == NULL) {
+		g_ctrlr_started = spdk_bit_array_create(128);
+		if (g_ctrlr_started == NULL) {
+			SPDK_ERRLOG("Cannot create bit array\n");
+			return -ENOMEM;
+		}
+	}
+
+	ctrlr_device = (struct cuse_device *)calloc(1, sizeof(struct cuse_device));
+	if (!ctrlr_device) {
+		SPDK_ERRLOG("Cannot allocate memory for ctrlr_device.");
+		rv = -ENOMEM;
+		goto err2;
+	}
+
+	ctrlr_device->ctrlr = ctrlr;
+
+	/* Check if device already exists, if not increment index until success */
+	ctrlr_device->index = 0;
+	while (1) {
+		ctrlr_device->index = spdk_bit_array_find_first_clear(g_ctrlr_started, ctrlr_device->index);
+		if (ctrlr_device->index == UINT32_MAX) {
+			SPDK_ERRLOG("Too many registered controllers\n");
+			goto err2;
+		}
+
+		if (nvme_cuse_claim(ctrlr_device, ctrlr_device->index) == 0) {
+			break;
+		}
+		ctrlr_device->index++;
+	}
+	spdk_bit_array_set(g_ctrlr_started, ctrlr_device->index);
+	snprintf(ctrlr_device->dev_name, sizeof(ctrlr_device->dev_name), "spdk/nvme%d",
+		 ctrlr_device->index);
+
+	rv = pthread_create(&ctrlr_device->tid, NULL, cuse_thread, ctrlr_device);
+	if (rv != 0) {
+		SPDK_ERRLOG("pthread_create failed\n");
+		rv = -rv;
+		goto err3;
+	}
+	TAILQ_INSERT_TAIL(&g_ctrlr_ctx_head, ctrlr_device, tailq);
+
+	ctrlr_device->ns_devices = (struct cuse_device *)calloc(num_ns, sizeof(struct cuse_device));
+	/* Start all active namespaces */
+	if (cuse_nvme_ctrlr_update_namespaces(ctrlr_device) < 0) {
+		SPDK_ERRLOG("Cannot start CUSE namespace devices.");
+		cuse_nvme_ctrlr_stop(ctrlr_device);
+		rv = -1;
+		goto err3;
+	}
+
+	return 0;
+
+err3:
+	spdk_bit_array_clear(g_ctrlr_started, ctrlr_device->index);
+err2:
+	free(ctrlr_device);
+	if (spdk_bit_array_count_set(g_ctrlr_started) == 0) {
+		spdk_bit_array_free(&g_ctrlr_started);
+	}
+	return rv;
+}
+
+static struct cuse_device *
+nvme_cuse_get_cuse_ctrlr_device(struct spdk_nvme_ctrlr *ctrlr)
+{
+	struct cuse_device *ctrlr_device = NULL;
+
+	TAILQ_FOREACH(ctrlr_device, &g_ctrlr_ctx_head, tailq) {
+		if (ctrlr_device->ctrlr == ctrlr) {
+			break;
+		}
+	}
+
+	return ctrlr_device;
+}
+
+static struct cuse_device *
+nvme_cuse_get_cuse_ns_device(struct spdk_nvme_ctrlr *ctrlr, uint32_t nsid)
+{
+	struct cuse_device *ctrlr_device = NULL;
+	uint32_t num_ns = spdk_nvme_ctrlr_get_num_ns(ctrlr);
+
+	if (nsid < 1 || nsid > num_ns) {
+		return NULL;
+	}
+
+	ctrlr_device = nvme_cuse_get_cuse_ctrlr_device(ctrlr);
+	if (!ctrlr_device) {
+		return NULL;
+	}
+
+	if (!ctrlr_device->ns_devices[nsid - 1].is_started) {
+		return NULL;
+	}
+
+	return &ctrlr_device->ns_devices[nsid - 1];
+}
+
+static void
+nvme_cuse_stop(struct spdk_nvme_ctrlr *ctrlr)
+{
+	struct cuse_device *ctrlr_device;
+
+	pthread_mutex_lock(&g_cuse_mtx);
+
+	ctrlr_device = nvme_cuse_get_cuse_ctrlr_device(ctrlr);
+	if (!ctrlr_device) {
+		SPDK_ERRLOG("Cannot find associated CUSE device\n");
+		pthread_mutex_unlock(&g_cuse_mtx);
+		return;
+	}
+
+	cuse_nvme_ctrlr_stop(ctrlr_device);
+
+	pthread_mutex_unlock(&g_cuse_mtx);
+}
+
+static void
+nvme_cuse_update(struct spdk_nvme_ctrlr *ctrlr)
+{
+	struct cuse_device *ctrlr_device;
+
+	pthread_mutex_lock(&g_cuse_mtx);
+
+	ctrlr_device = nvme_cuse_get_cuse_ctrlr_device(ctrlr);
+	if (!ctrlr_device) {
+		pthread_mutex_unlock(&g_cuse_mtx);
+		return;
+	}
+
+	cuse_nvme_ctrlr_update_namespaces(ctrlr_device);
+
+	pthread_mutex_unlock(&g_cuse_mtx);
+}
+
+static struct nvme_io_msg_producer cuse_nvme_io_msg_producer = {
+	.name = "cuse",
+	.stop = nvme_cuse_stop,
+	.update = nvme_cuse_update,
+};
+
+int
+spdk_nvme_cuse_register(struct spdk_nvme_ctrlr *ctrlr)
+{
+	int rc;
+
+	rc = nvme_io_msg_ctrlr_register(ctrlr, &cuse_nvme_io_msg_producer);
+	if (rc) {
+		return rc;
+	}
+
+	pthread_mutex_lock(&g_cuse_mtx);
+
+	rc = nvme_cuse_start(ctrlr);
+	if (rc) {
+		nvme_io_msg_ctrlr_unregister(ctrlr, &cuse_nvme_io_msg_producer);
+	}
+
+	pthread_mutex_unlock(&g_cuse_mtx);
+
+	return rc;
+}
+
+int
+spdk_nvme_cuse_unregister(struct spdk_nvme_ctrlr *ctrlr)
+{
+	struct cuse_device *ctrlr_device;
+
+	pthread_mutex_lock(&g_cuse_mtx);
+
+	ctrlr_device = nvme_cuse_get_cuse_ctrlr_device(ctrlr);
+	if (!ctrlr_device) {
+		SPDK_ERRLOG("Cannot find associated CUSE device\n");
+		pthread_mutex_unlock(&g_cuse_mtx);
+		return -ENODEV;
+	}
+
+	cuse_nvme_ctrlr_stop(ctrlr_device);
+
+	pthread_mutex_unlock(&g_cuse_mtx);
+
+	nvme_io_msg_ctrlr_unregister(ctrlr, &cuse_nvme_io_msg_producer);
+
+	return 0;
+}
+
+void
+spdk_nvme_cuse_update_namespaces(struct spdk_nvme_ctrlr *ctrlr)
+{
+	nvme_cuse_update(ctrlr);
+}
+
+int
+spdk_nvme_cuse_get_ctrlr_name(struct spdk_nvme_ctrlr *ctrlr, char *name, size_t *size)
+{
+	struct cuse_device *ctrlr_device;
+	size_t req_len;
+
+	pthread_mutex_lock(&g_cuse_mtx);
+
+	ctrlr_device = nvme_cuse_get_cuse_ctrlr_device(ctrlr);
+	if (!ctrlr_device) {
+		pthread_mutex_unlock(&g_cuse_mtx);
+		return -ENODEV;
+	}
+
+	req_len = strnlen(ctrlr_device->dev_name, sizeof(ctrlr_device->dev_name));
+	if (*size < req_len) {
+		*size = req_len;
+		pthread_mutex_unlock(&g_cuse_mtx);
+		return -ENOSPC;
+	}
+	snprintf(name, req_len + 1, "%s", ctrlr_device->dev_name);
+
+	pthread_mutex_unlock(&g_cuse_mtx);
+
+	return 0;
+}
+
+int
+spdk_nvme_cuse_get_ns_name(struct spdk_nvme_ctrlr *ctrlr, uint32_t nsid, char *name, size_t *size)
+{
+	struct cuse_device *ns_device;
+	size_t req_len;
+
+	pthread_mutex_lock(&g_cuse_mtx);
+
+	ns_device = nvme_cuse_get_cuse_ns_device(ctrlr, nsid);
+	if (!ns_device) {
+		pthread_mutex_unlock(&g_cuse_mtx);
+		return -ENODEV;
+	}
+
+	req_len = strnlen(ns_device->dev_name, sizeof(ns_device->dev_name));
+	if (*size < req_len) {
+		*size = req_len;
+		pthread_mutex_unlock(&g_cuse_mtx);
+		return -ENOSPC;
+	}
+	snprintf(name, req_len + 1, "%s", ns_device->dev_name);
+
+	pthread_mutex_unlock(&g_cuse_mtx);
+
+	return 0;
+}