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Subject[PATCH v5 11/13] nvmet-tcp: add NVMe over TCP target driver
Date
From: Sagi Grimberg <sagi@lightbitslabs.com>

This patch implements the TCP transport driver for the NVMe over Fabrics
target stack. This allows exporting NVMe over Fabrics functionality over
good old TCP/IP.

The driver implements the TP 8000 of how nvme over fabrics capsules and
data are encapsulated in nvme-tcp pdus and exchaged on top of a TCP byte
stream. nvme-tcp header and data digest are supported as well.

Signed-off-by: Sagi Grimberg <sagi@lightbitslabs.com>
Signed-off-by: Roy Shterman <roys@lightbitslabs.com>
Signed-off-by: Solganik Alexander <sashas@lightbitslabs.com>
---
drivers/nvme/target/Kconfig | 10 +
drivers/nvme/target/Makefile | 2 +
drivers/nvme/target/tcp.c | 1737 ++++++++++++++++++++++++++++++++++
3 files changed, 1749 insertions(+)
create mode 100644 drivers/nvme/target/tcp.c

diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig
index 3c7b61ddb0d1..d94f25cde019 100644
--- a/drivers/nvme/target/Kconfig
+++ b/drivers/nvme/target/Kconfig
@@ -60,3 +60,13 @@ config NVME_TARGET_FCLOOP
to test NVMe-FC transport interfaces.

If unsure, say N.
+
+config NVME_TARGET_TCP
+ tristate "NVMe over Fabrics TCP target support"
+ depends on INET
+ depends on NVME_TARGET
+ help
+ This enables the NVMe TCP target support, which allows exporting NVMe
+ devices over TCP.
+
+ If unsure, say N.
diff --git a/drivers/nvme/target/Makefile b/drivers/nvme/target/Makefile
index 8118c93391c6..8c3ad0fb6860 100644
--- a/drivers/nvme/target/Makefile
+++ b/drivers/nvme/target/Makefile
@@ -5,6 +5,7 @@ obj-$(CONFIG_NVME_TARGET_LOOP) += nvme-loop.o
obj-$(CONFIG_NVME_TARGET_RDMA) += nvmet-rdma.o
obj-$(CONFIG_NVME_TARGET_FC) += nvmet-fc.o
obj-$(CONFIG_NVME_TARGET_FCLOOP) += nvme-fcloop.o
+obj-$(CONFIG_NVME_TARGET_TCP) += nvmet-tcp.o

nvmet-y += core.o configfs.o admin-cmd.o fabrics-cmd.o \
discovery.o io-cmd-file.o io-cmd-bdev.o
@@ -12,3 +13,4 @@ nvme-loop-y += loop.o
nvmet-rdma-y += rdma.o
nvmet-fc-y += fc.o
nvme-fcloop-y += fcloop.o
+nvmet-tcp-y += tcp.o
diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
new file mode 100644
index 000000000000..d31bec260160
--- /dev/null
+++ b/drivers/nvme/target/tcp.c
@@ -0,0 +1,1737 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NVMe over Fabrics TCP target.
+ * Copyright (c) 2018 Lightbits Labs. All rights reserved.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/nvme-tcp.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+#include <linux/inet.h>
+#include <linux/llist.h>
+#include <crypto/hash.h>
+
+#include "nvmet.h"
+
+#define NVMET_TCP_DEF_INLINE_DATA_SIZE (4 * PAGE_SIZE)
+
+#define NVMET_TCP_RECV_BUDGET 8
+#define NVMET_TCP_SEND_BUDGET 8
+#define NVMET_TCP_IO_WORK_BUDGET 64
+
+enum nvmet_tcp_send_state {
+ NVMET_TCP_SEND_DATA_PDU,
+ NVMET_TCP_SEND_DATA,
+ NVMET_TCP_SEND_R2T,
+ NVMET_TCP_SEND_DDGST,
+ NVMET_TCP_SEND_RESPONSE
+};
+
+enum nvmet_tcp_recv_state {
+ NVMET_TCP_RECV_PDU,
+ NVMET_TCP_RECV_DATA,
+ NVMET_TCP_RECV_DDGST,
+ NVMET_TCP_RECV_ERR,
+};
+
+enum {
+ NVMET_TCP_F_INIT_FAILED = (1 << 0),
+};
+
+struct nvmet_tcp_cmd {
+ struct nvmet_tcp_queue *queue;
+ struct nvmet_req req;
+
+ struct nvme_tcp_cmd_pdu *cmd_pdu;
+ struct nvme_tcp_rsp_pdu *rsp_pdu;
+ struct nvme_tcp_data_pdu *data_pdu;
+ struct nvme_tcp_r2t_pdu *r2t_pdu;
+
+ u32 rbytes_done;
+ u32 wbytes_done;
+
+ u32 pdu_len;
+ u32 pdu_recv;
+ int sg_idx;
+ int nr_mapped;
+ struct msghdr recv_msg;
+ struct kvec *iov;
+ u32 flags;
+
+ struct list_head entry;
+ struct llist_node lentry;
+
+ /* send state */
+ u32 offset;
+ struct scatterlist *cur_sg;
+ enum nvmet_tcp_send_state state;
+
+ __le32 exp_ddgst;
+ __le32 recv_ddgst;
+};
+
+enum nvmet_tcp_queue_state {
+ NVMET_TCP_Q_CONNECTING,
+ NVMET_TCP_Q_LIVE,
+ NVMET_TCP_Q_DISCONNECTING,
+};
+
+struct nvmet_tcp_queue {
+ struct socket *sock;
+ struct nvmet_tcp_port *port;
+ struct work_struct io_work;
+ int cpu;
+ struct nvmet_cq nvme_cq;
+ struct nvmet_sq nvme_sq;
+
+ /* send state */
+ struct nvmet_tcp_cmd *cmds;
+ unsigned int nr_cmds;
+ struct list_head free_list;
+ struct llist_head resp_list;
+ struct list_head resp_send_list;
+ int send_list_len;
+ struct nvmet_tcp_cmd *snd_cmd;
+
+ /* recv state */
+ int offset;
+ int left;
+ enum nvmet_tcp_recv_state rcv_state;
+ struct nvmet_tcp_cmd *cmd;
+ union nvme_tcp_pdu pdu;
+
+ /* digest state */
+ bool hdr_digest;
+ bool data_digest;
+ struct ahash_request *snd_hash;
+ struct ahash_request *rcv_hash;
+
+ spinlock_t state_lock;
+ enum nvmet_tcp_queue_state state;
+
+ struct sockaddr_storage sockaddr;
+ struct sockaddr_storage sockaddr_peer;
+ struct work_struct release_work;
+
+ int idx;
+ struct list_head queue_list;
+
+ struct nvmet_tcp_cmd connect;
+
+ struct page_frag_cache pf_cache;
+
+ void (*data_ready)(struct sock *);
+ void (*state_change)(struct sock *);
+ void (*write_space)(struct sock *);
+};
+
+struct nvmet_tcp_port {
+ struct socket *sock;
+ struct work_struct accept_work;
+ struct nvmet_port *nport;
+ struct sockaddr_storage addr;
+ int last_cpu;
+ void (*data_ready)(struct sock *);
+};
+
+static DEFINE_IDA(nvmet_tcp_queue_ida);
+static LIST_HEAD(nvmet_tcp_queue_list);
+static DEFINE_MUTEX(nvmet_tcp_queue_mutex);
+
+static struct workqueue_struct *nvmet_tcp_wq;
+static struct nvmet_fabrics_ops nvmet_tcp_ops;
+static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c);
+static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd);
+
+static inline u16 nvmet_tcp_cmd_tag(struct nvmet_tcp_queue *queue,
+ struct nvmet_tcp_cmd *cmd)
+{
+ return cmd - queue->cmds;
+}
+
+static inline bool nvmet_tcp_has_data_in(struct nvmet_tcp_cmd *cmd)
+{
+ return nvme_is_write(cmd->req.cmd) &&
+ cmd->rbytes_done < cmd->req.transfer_len;
+}
+
+static inline bool nvmet_tcp_need_data_in(struct nvmet_tcp_cmd *cmd)
+{
+ return nvmet_tcp_has_data_in(cmd) && !cmd->req.rsp->status;
+}
+
+static inline bool nvmet_tcp_need_data_out(struct nvmet_tcp_cmd *cmd)
+{
+ return !nvme_is_write(cmd->req.cmd) &&
+ cmd->req.transfer_len > 0 &&
+ !cmd->req.rsp->status;
+}
+
+static inline bool nvmet_tcp_has_inline_data(struct nvmet_tcp_cmd *cmd)
+{
+ return nvme_is_write(cmd->req.cmd) && cmd->pdu_len &&
+ !cmd->rbytes_done;
+}
+
+static inline struct nvmet_tcp_cmd *
+nvmet_tcp_get_cmd(struct nvmet_tcp_queue *queue)
+{
+ struct nvmet_tcp_cmd *cmd;
+
+ cmd = list_first_entry_or_null(&queue->free_list,
+ struct nvmet_tcp_cmd, entry);
+ if (!cmd)
+ return NULL;
+ list_del_init(&cmd->entry);
+
+ cmd->rbytes_done = cmd->wbytes_done = 0;
+ cmd->pdu_len = 0;
+ cmd->pdu_recv = 0;
+ cmd->iov = NULL;
+ cmd->flags = 0;
+ return cmd;
+}
+
+static inline void nvmet_tcp_put_cmd(struct nvmet_tcp_cmd *cmd)
+{
+ if (unlikely(cmd == &cmd->queue->connect))
+ return;
+
+ list_add_tail(&cmd->entry, &cmd->queue->free_list);
+}
+
+static inline u8 nvmet_tcp_hdgst_len(struct nvmet_tcp_queue *queue)
+{
+ return queue->hdr_digest ? NVME_TCP_DIGEST_LENGTH : 0;
+}
+
+static inline u8 nvmet_tcp_ddgst_len(struct nvmet_tcp_queue *queue)
+{
+ return queue->data_digest ? NVME_TCP_DIGEST_LENGTH : 0;
+}
+
+static inline void nvmet_tcp_hdgst(struct ahash_request *hash,
+ void *pdu, size_t len)
+{
+ struct scatterlist sg;
+
+ sg_init_one(&sg, pdu, len);
+ ahash_request_set_crypt(hash, &sg, pdu + len, len);
+ crypto_ahash_digest(hash);
+}
+
+static int nvmet_tcp_verify_hdgst(struct nvmet_tcp_queue *queue,
+ void *pdu, size_t len)
+{
+ struct nvme_tcp_hdr *hdr = pdu;
+ __le32 recv_digest;
+ __le32 exp_digest;
+
+ if (unlikely(!(hdr->flags & NVME_TCP_F_HDGST))) {
+ pr_err("queue %d: header digest enabled but no header digest\n",
+ queue->idx);
+ return -EPROTO;
+ }
+
+ recv_digest = *(__le32 *)(pdu + hdr->hlen);
+ nvmet_tcp_hdgst(queue->rcv_hash, pdu, len);
+ exp_digest = *(__le32 *)(pdu + hdr->hlen);
+ if (recv_digest != exp_digest) {
+ pr_err("queue %d: header digest error: recv %#x expected %#x\n",
+ queue->idx, le32_to_cpu(recv_digest),
+ le32_to_cpu(exp_digest));
+ return -EPROTO;
+ }
+
+ return 0;
+}
+
+static int nvmet_tcp_check_ddgst(struct nvmet_tcp_queue *queue, void *pdu)
+{
+ struct nvme_tcp_hdr *hdr = pdu;
+ u8 digest_len = nvmet_tcp_hdgst_len(queue);
+ u32 len;
+
+ len = le32_to_cpu(hdr->plen) - hdr->hlen -
+ (hdr->flags & NVME_TCP_F_HDGST ? digest_len : 0);
+
+ if (unlikely(len && !(hdr->flags & NVME_TCP_F_DDGST))) {
+ pr_err("queue %d: data digest flag is cleared\n", queue->idx);
+ return -EPROTO;
+ }
+
+ return 0;
+}
+
+static void nvmet_tcp_unmap_pdu_iovec(struct nvmet_tcp_cmd *cmd)
+{
+ struct scatterlist *sg;
+ int i;
+
+ sg = &cmd->req.sg[cmd->sg_idx];
+
+ for (i = 0; i < cmd->nr_mapped; i++)
+ kunmap(sg_page(&sg[i]));
+}
+
+static void nvmet_tcp_map_pdu_iovec(struct nvmet_tcp_cmd *cmd)
+{
+ struct kvec *iov = cmd->iov;
+ struct scatterlist *sg;
+ u32 length, offset, sg_offset;
+
+ length = cmd->pdu_len;
+ cmd->nr_mapped = DIV_ROUND_UP(length, PAGE_SIZE);
+ offset = cmd->rbytes_done;
+ cmd->sg_idx = DIV_ROUND_UP(offset, PAGE_SIZE);
+ sg_offset = offset % PAGE_SIZE;
+ sg = &cmd->req.sg[cmd->sg_idx];
+
+ while (length) {
+ u32 iov_len = min_t(u32, length, sg->length - sg_offset);
+
+ iov->iov_base = kmap(sg_page(sg)) + sg->offset + sg_offset;
+ iov->iov_len = iov_len;
+
+ length -= iov_len;
+ sg = sg_next(sg);
+ iov++;
+ }
+
+ iov_iter_kvec(&cmd->recv_msg.msg_iter, READ, cmd->iov,
+ cmd->nr_mapped, cmd->pdu_len);
+}
+
+static void nvmet_tcp_fatal_error(struct nvmet_tcp_queue *queue)
+{
+ queue->rcv_state = NVMET_TCP_RECV_ERR;
+ if (queue->nvme_sq.ctrl)
+ nvmet_ctrl_fatal_error(queue->nvme_sq.ctrl);
+ else
+ kernel_sock_shutdown(queue->sock, SHUT_RDWR);
+}
+
+static int nvmet_tcp_map_data(struct nvmet_tcp_cmd *cmd)
+{
+ struct nvme_sgl_desc *sgl = &cmd->req.cmd->common.dptr.sgl;
+ u32 len = le32_to_cpu(sgl->length);
+
+ if (!cmd->req.data_len)
+ return 0;
+
+ if (sgl->type == ((NVME_SGL_FMT_DATA_DESC << 4) |
+ NVME_SGL_FMT_OFFSET)) {
+ if (!nvme_is_write(cmd->req.cmd))
+ return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+
+ if (len > cmd->req.port->inline_data_size)
+ return NVME_SC_SGL_INVALID_OFFSET | NVME_SC_DNR;
+ cmd->pdu_len = len;
+ }
+ cmd->req.transfer_len += len;
+
+ cmd->req.sg = sgl_alloc(len, GFP_KERNEL, &cmd->req.sg_cnt);
+ if (!cmd->req.sg)
+ return NVME_SC_INTERNAL;
+ cmd->cur_sg = cmd->req.sg;
+
+ if (nvmet_tcp_has_data_in(cmd)) {
+ cmd->iov = kmalloc_array(cmd->req.sg_cnt,
+ sizeof(*cmd->iov), GFP_KERNEL);
+ if (!cmd->iov)
+ goto err;
+ }
+
+ return 0;
+err:
+ sgl_free(cmd->req.sg);
+ return NVME_SC_INTERNAL;
+}
+
+static void nvmet_tcp_ddgst(struct ahash_request *hash,
+ struct nvmet_tcp_cmd *cmd)
+{
+ ahash_request_set_crypt(hash, cmd->req.sg,
+ (void *)&cmd->exp_ddgst, cmd->req.transfer_len);
+ crypto_ahash_digest(hash);
+}
+
+static void nvmet_setup_c2h_data_pdu(struct nvmet_tcp_cmd *cmd)
+{
+ struct nvme_tcp_data_pdu *pdu = cmd->data_pdu;
+ struct nvmet_tcp_queue *queue = cmd->queue;
+ u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
+ u8 ddgst = nvmet_tcp_ddgst_len(cmd->queue);
+
+ cmd->offset = 0;
+ cmd->state = NVMET_TCP_SEND_DATA_PDU;
+
+ pdu->hdr.type = nvme_tcp_c2h_data;
+ pdu->hdr.flags = NVME_TCP_F_DATA_LAST;
+ pdu->hdr.hlen = sizeof(*pdu);
+ pdu->hdr.pdo = pdu->hdr.hlen + hdgst;
+ pdu->hdr.plen =
+ cpu_to_le32(pdu->hdr.hlen + hdgst +
+ cmd->req.transfer_len + ddgst);
+ pdu->command_id = cmd->req.rsp->command_id;
+ pdu->data_length = cpu_to_le32(cmd->req.transfer_len);
+ pdu->data_offset = cpu_to_le32(cmd->wbytes_done);
+
+ if (queue->data_digest) {
+ pdu->hdr.flags |= NVME_TCP_F_DDGST;
+ nvmet_tcp_ddgst(queue->snd_hash, cmd);
+ }
+
+ if (cmd->queue->hdr_digest) {
+ pdu->hdr.flags |= NVME_TCP_F_HDGST;
+ nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
+ }
+}
+
+static void nvmet_setup_r2t_pdu(struct nvmet_tcp_cmd *cmd)
+{
+ struct nvme_tcp_r2t_pdu *pdu = cmd->r2t_pdu;
+ struct nvmet_tcp_queue *queue = cmd->queue;
+ u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
+
+ cmd->offset = 0;
+ cmd->state = NVMET_TCP_SEND_R2T;
+
+ pdu->hdr.type = nvme_tcp_r2t;
+ pdu->hdr.flags = 0;
+ pdu->hdr.hlen = sizeof(*pdu);
+ pdu->hdr.pdo = 0;
+ pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
+
+ pdu->command_id = cmd->req.cmd->common.command_id;
+ pdu->ttag = nvmet_tcp_cmd_tag(cmd->queue, cmd);
+ pdu->r2t_length = cpu_to_le32(cmd->req.transfer_len - cmd->rbytes_done);
+ pdu->r2t_offset = cpu_to_le32(cmd->rbytes_done);
+ if (cmd->queue->hdr_digest) {
+ pdu->hdr.flags |= NVME_TCP_F_HDGST;
+ nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
+ }
+}
+
+static void nvmet_setup_response_pdu(struct nvmet_tcp_cmd *cmd)
+{
+ struct nvme_tcp_rsp_pdu *pdu = cmd->rsp_pdu;
+ struct nvmet_tcp_queue *queue = cmd->queue;
+ u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
+
+ cmd->offset = 0;
+ cmd->state = NVMET_TCP_SEND_RESPONSE;
+
+ pdu->hdr.type = nvme_tcp_rsp;
+ pdu->hdr.flags = 0;
+ pdu->hdr.hlen = sizeof(*pdu);
+ pdu->hdr.pdo = 0;
+ pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
+ if (cmd->queue->hdr_digest) {
+ pdu->hdr.flags |= NVME_TCP_F_HDGST;
+ nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
+ }
+}
+
+static void nvmet_tcp_process_resp_list(struct nvmet_tcp_queue *queue)
+{
+ struct llist_node *node;
+
+ node = llist_del_all(&queue->resp_list);
+ if (!node)
+ return;
+
+ while (node) {
+ struct nvmet_tcp_cmd *cmd = llist_entry(node,
+ struct nvmet_tcp_cmd, lentry);
+
+ list_add(&cmd->entry, &queue->resp_send_list);
+ node = node->next;
+ queue->send_list_len++;
+ }
+}
+
+static struct nvmet_tcp_cmd *nvmet_tcp_fetch_cmd(struct nvmet_tcp_queue *queue)
+{
+ queue->snd_cmd = list_first_entry_or_null(&queue->resp_send_list,
+ struct nvmet_tcp_cmd, entry);
+ if (!queue->snd_cmd) {
+ nvmet_tcp_process_resp_list(queue);
+ queue->snd_cmd =
+ list_first_entry_or_null(&queue->resp_send_list,
+ struct nvmet_tcp_cmd, entry);
+ if (unlikely(!queue->snd_cmd))
+ return NULL;
+ }
+
+ list_del_init(&queue->snd_cmd->entry);
+ queue->send_list_len--;
+
+ if (nvmet_tcp_need_data_out(queue->snd_cmd))
+ nvmet_setup_c2h_data_pdu(queue->snd_cmd);
+ else if (nvmet_tcp_need_data_in(queue->snd_cmd))
+ nvmet_setup_r2t_pdu(queue->snd_cmd);
+ else
+ nvmet_setup_response_pdu(queue->snd_cmd);
+
+ return queue->snd_cmd;
+}
+
+static void nvmet_tcp_queue_response(struct nvmet_req *req)
+{
+ struct nvmet_tcp_cmd *cmd =
+ container_of(req, struct nvmet_tcp_cmd, req);
+ struct nvmet_tcp_queue *queue = cmd->queue;
+
+ llist_add(&cmd->lentry, &queue->resp_list);
+ queue_work_on(cmd->queue->cpu, nvmet_tcp_wq, &cmd->queue->io_work);
+}
+
+static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)
+{
+ u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
+ int left = sizeof(*cmd->data_pdu) - cmd->offset + hdgst;
+ int ret;
+
+ ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->data_pdu),
+ offset_in_page(cmd->data_pdu) + cmd->offset,
+ left, MSG_DONTWAIT | MSG_MORE);
+ if (ret <= 0)
+ return ret;
+
+ cmd->offset += ret;
+ left -= ret;
+
+ if (left)
+ return -EAGAIN;
+
+ cmd->state = NVMET_TCP_SEND_DATA;
+ cmd->offset = 0;
+ return 1;
+}
+
+static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd)
+{
+ struct nvmet_tcp_queue *queue = cmd->queue;
+ int ret;
+
+ while (cmd->cur_sg) {
+ struct page *page = sg_page(cmd->cur_sg);
+ u32 left = cmd->cur_sg->length - cmd->offset;
+
+ ret = kernel_sendpage(cmd->queue->sock, page, cmd->offset,
+ left, MSG_DONTWAIT | MSG_MORE);
+ if (ret <= 0)
+ return ret;
+
+ cmd->offset += ret;
+ cmd->wbytes_done += ret;
+
+ /* Done with sg?*/
+ if (cmd->offset == cmd->cur_sg->length) {
+ cmd->cur_sg = sg_next(cmd->cur_sg);
+ cmd->offset = 0;
+ }
+ }
+
+ if (queue->data_digest) {
+ cmd->state = NVMET_TCP_SEND_DDGST;
+ cmd->offset = 0;
+ } else {
+ nvmet_setup_response_pdu(cmd);
+ }
+ return 1;
+
+}
+
+static int nvmet_try_send_response(struct nvmet_tcp_cmd *cmd,
+ bool last_in_batch)
+{
+ u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
+ int left = sizeof(*cmd->rsp_pdu) - cmd->offset + hdgst;
+ int flags = MSG_DONTWAIT;
+ int ret;
+
+ if (!last_in_batch && cmd->queue->send_list_len)
+ flags |= MSG_MORE;
+ else
+ flags |= MSG_EOR;
+
+ ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->rsp_pdu),
+ offset_in_page(cmd->rsp_pdu) + cmd->offset, left, flags);
+ if (ret <= 0)
+ return ret;
+ cmd->offset += ret;
+ left -= ret;
+
+ if (left)
+ return -EAGAIN;
+
+ kfree(cmd->iov);
+ sgl_free(cmd->req.sg);
+ cmd->queue->snd_cmd = NULL;
+ nvmet_tcp_put_cmd(cmd);
+ return 1;
+}
+
+static int nvmet_try_send_r2t(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
+{
+ u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
+ int left = sizeof(*cmd->r2t_pdu) - cmd->offset + hdgst;
+ int flags = MSG_DONTWAIT;
+ int ret;
+
+ if (!last_in_batch && cmd->queue->send_list_len)
+ flags |= MSG_MORE;
+ else
+ flags |= MSG_EOR;
+
+ ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->r2t_pdu),
+ offset_in_page(cmd->r2t_pdu) + cmd->offset, left, flags);
+ if (ret <= 0)
+ return ret;
+ cmd->offset += ret;
+ left -= ret;
+
+ if (left)
+ return -EAGAIN;
+
+ cmd->queue->snd_cmd = NULL;
+ return 1;
+}
+
+static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd)
+{
+ struct nvmet_tcp_queue *queue = cmd->queue;
+ struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
+ struct kvec iov = {
+ .iov_base = &cmd->exp_ddgst + cmd->offset,
+ .iov_len = NVME_TCP_DIGEST_LENGTH - cmd->offset
+ };
+ int ret;
+
+ ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
+ if (unlikely(ret <= 0))
+ return ret;
+
+ cmd->offset += ret;
+ nvmet_setup_response_pdu(cmd);
+ return 1;
+}
+
+static int nvmet_tcp_try_send_one(struct nvmet_tcp_queue *queue,
+ bool last_in_batch)
+{
+ struct nvmet_tcp_cmd *cmd = queue->snd_cmd;
+ int ret = 0;
+
+ if (!cmd || queue->state == NVMET_TCP_Q_DISCONNECTING) {
+ cmd = nvmet_tcp_fetch_cmd(queue);
+ if (unlikely(!cmd))
+ return 0;
+ }
+
+ if (cmd->state == NVMET_TCP_SEND_DATA_PDU) {
+ ret = nvmet_try_send_data_pdu(cmd);
+ if (ret <= 0)
+ goto done_send;
+ }
+
+ if (cmd->state == NVMET_TCP_SEND_DATA) {
+ ret = nvmet_try_send_data(cmd);
+ if (ret <= 0)
+ goto done_send;
+ }
+
+ if (cmd->state == NVMET_TCP_SEND_DDGST) {
+ ret = nvmet_try_send_ddgst(cmd);
+ if (ret <= 0)
+ goto done_send;
+ }
+
+ if (cmd->state == NVMET_TCP_SEND_R2T) {
+ ret = nvmet_try_send_r2t(cmd, last_in_batch);
+ if (ret <= 0)
+ goto done_send;
+ }
+
+ if (cmd->state == NVMET_TCP_SEND_RESPONSE)
+ ret = nvmet_try_send_response(cmd, last_in_batch);
+
+done_send:
+ if (ret < 0) {
+ if (ret == -EAGAIN)
+ return 0;
+ return ret;
+ }
+
+ return 1;
+}
+
+static int nvmet_tcp_try_send(struct nvmet_tcp_queue *queue,
+ int budget, int *sends)
+{
+ int i, ret = 0;
+
+ for (i = 0; i < budget; i++) {
+ ret = nvmet_tcp_try_send_one(queue, i == budget - 1);
+ if (ret <= 0)
+ break;
+ (*sends)++;
+ }
+
+ return ret;
+}
+
+static void nvmet_prepare_receive_pdu(struct nvmet_tcp_queue *queue)
+{
+ queue->offset = 0;
+ queue->left = sizeof(struct nvme_tcp_hdr);
+ queue->cmd = NULL;
+ queue->rcv_state = NVMET_TCP_RECV_PDU;
+}
+
+static void nvmet_tcp_free_crypto(struct nvmet_tcp_queue *queue)
+{
+ struct crypto_ahash *tfm = crypto_ahash_reqtfm(queue->rcv_hash);
+
+ ahash_request_free(queue->rcv_hash);
+ ahash_request_free(queue->snd_hash);
+ crypto_free_ahash(tfm);
+}
+
+static int nvmet_tcp_alloc_crypto(struct nvmet_tcp_queue *queue)
+{
+ struct crypto_ahash *tfm;
+
+ tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
+
+ queue->snd_hash = ahash_request_alloc(tfm, GFP_KERNEL);
+ if (!queue->snd_hash)
+ goto free_tfm;
+ ahash_request_set_callback(queue->snd_hash, 0, NULL, NULL);
+
+ queue->rcv_hash = ahash_request_alloc(tfm, GFP_KERNEL);
+ if (!queue->rcv_hash)
+ goto free_snd_hash;
+ ahash_request_set_callback(queue->rcv_hash, 0, NULL, NULL);
+
+ return 0;
+free_snd_hash:
+ ahash_request_free(queue->snd_hash);
+free_tfm:
+ crypto_free_ahash(tfm);
+ return -ENOMEM;
+}
+
+
+static int nvmet_tcp_handle_icreq(struct nvmet_tcp_queue *queue)
+{
+ struct nvme_tcp_icreq_pdu *icreq = &queue->pdu.icreq;
+ struct nvme_tcp_icresp_pdu *icresp = &queue->pdu.icresp;
+ struct msghdr msg = {};
+ struct kvec iov;
+ int ret;
+
+ if (le32_to_cpu(icreq->hdr.plen) != sizeof(struct nvme_tcp_icreq_pdu)) {
+ pr_err("bad nvme-tcp pdu length (%d)\n",
+ le32_to_cpu(icreq->hdr.plen));
+ nvmet_tcp_fatal_error(queue);
+ }
+
+ if (icreq->pfv != NVME_TCP_PFV_1_0) {
+ pr_err("queue %d: bad pfv %d\n", queue->idx, icreq->pfv);
+ return -EPROTO;
+ }
+
+ if (icreq->hpda != 0) {
+ pr_err("queue %d: unsupported hpda %d\n", queue->idx,
+ icreq->hpda);
+ return -EPROTO;
+ }
+
+ if (icreq->maxr2t != 0) {
+ pr_err("queue %d: unsupported maxr2t %d\n", queue->idx,
+ le16_to_cpu(icreq->maxr2t) + 1);
+ return -EPROTO;
+ }
+
+ queue->hdr_digest = !!(icreq->digest & NVME_TCP_HDR_DIGEST_ENABLE);
+ queue->data_digest = !!(icreq->digest & NVME_TCP_DATA_DIGEST_ENABLE);
+ if (queue->hdr_digest || queue->data_digest) {
+ ret = nvmet_tcp_alloc_crypto(queue);
+ if (ret)
+ return ret;
+ }
+
+ memset(icresp, 0, sizeof(*icresp));
+ icresp->hdr.type = nvme_tcp_icresp;
+ icresp->hdr.hlen = sizeof(*icresp);
+ icresp->hdr.pdo = 0;
+ icresp->hdr.plen = cpu_to_le32(icresp->hdr.hlen);
+ icresp->pfv = cpu_to_le16(NVME_TCP_PFV_1_0);
+ icresp->maxdata = 0xffff; /* FIXME: support r2t */
+ icresp->cpda = 0;
+ if (queue->hdr_digest)
+ icresp->digest |= NVME_TCP_HDR_DIGEST_ENABLE;
+ if (queue->data_digest)
+ icresp->digest |= NVME_TCP_DATA_DIGEST_ENABLE;
+
+ iov.iov_base = icresp;
+ iov.iov_len = sizeof(*icresp);
+ ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
+ if (ret < 0)
+ goto free_crypto;
+
+ queue->state = NVMET_TCP_Q_LIVE;
+ nvmet_prepare_receive_pdu(queue);
+ return 0;
+free_crypto:
+ if (queue->hdr_digest || queue->data_digest)
+ nvmet_tcp_free_crypto(queue);
+ return ret;
+}
+
+static void nvmet_tcp_handle_req_failure(struct nvmet_tcp_queue *queue,
+ struct nvmet_tcp_cmd *cmd, struct nvmet_req *req)
+{
+ int ret;
+
+ /* recover the expected data transfer length */
+ req->data_len = le32_to_cpu(req->cmd->common.dptr.sgl.length);
+
+ if (!nvme_is_write(cmd->req.cmd) ||
+ req->data_len > cmd->req.port->inline_data_size) {
+ nvmet_prepare_receive_pdu(queue);
+ return;
+ }
+
+ ret = nvmet_tcp_map_data(cmd);
+ if (unlikely(ret)) {
+ pr_err("queue %d: failed to map data\n", queue->idx);
+ nvmet_tcp_fatal_error(queue);
+ return;
+ }
+
+ queue->rcv_state = NVMET_TCP_RECV_DATA;
+ nvmet_tcp_map_pdu_iovec(cmd);
+ cmd->flags |= NVMET_TCP_F_INIT_FAILED;
+}
+
+static int nvmet_tcp_handle_h2c_data_pdu(struct nvmet_tcp_queue *queue)
+{
+ struct nvme_tcp_data_pdu *data = &queue->pdu.data;
+ struct nvmet_tcp_cmd *cmd;
+
+ cmd = &queue->cmds[data->ttag];
+
+ if (le32_to_cpu(data->data_offset) != cmd->rbytes_done) {
+ pr_err("ttag %u unexpected data offset %u (expected %u)\n",
+ data->ttag, le32_to_cpu(data->data_offset),
+ cmd->rbytes_done);
+ /* FIXME: use path and transport errors */
+ nvmet_req_complete(&cmd->req,
+ NVME_SC_INVALID_FIELD | NVME_SC_DNR);
+ return -EPROTO;
+ }
+
+ cmd->pdu_len = le32_to_cpu(data->data_length);
+ cmd->pdu_recv = 0;
+ nvmet_tcp_map_pdu_iovec(cmd);
+ queue->cmd = cmd;
+ queue->rcv_state = NVMET_TCP_RECV_DATA;
+
+ return 0;
+}
+
+static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
+{
+ struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
+ struct nvme_command *nvme_cmd = &queue->pdu.cmd.cmd;
+ struct nvmet_req *req;
+ int ret;
+
+ if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
+ if (hdr->type != nvme_tcp_icreq) {
+ pr_err("unexpected pdu type (%d) before icreq\n",
+ hdr->type);
+ nvmet_tcp_fatal_error(queue);
+ return -EPROTO;
+ }
+ return nvmet_tcp_handle_icreq(queue);
+ }
+
+ if (hdr->type == nvme_tcp_h2c_data) {
+ ret = nvmet_tcp_handle_h2c_data_pdu(queue);
+ if (unlikely(ret))
+ return ret;
+ return 0;
+ }
+
+ queue->cmd = nvmet_tcp_get_cmd(queue);
+ if (unlikely(!queue->cmd)) {
+ /* This should never happen */
+ pr_err("queue %d: out of commands (%d) send_list_len: %d, opcode: %d",
+ queue->idx, queue->nr_cmds, queue->send_list_len,
+ nvme_cmd->common.opcode);
+ nvmet_tcp_fatal_error(queue);
+ return -ENOMEM;
+ }
+
+ req = &queue->cmd->req;
+ memcpy(req->cmd, nvme_cmd, sizeof(*nvme_cmd));
+
+ if (unlikely(!nvmet_req_init(req, &queue->nvme_cq,
+ &queue->nvme_sq, &nvmet_tcp_ops))) {
+ pr_err("failed cmd %p id %d opcode %d, data_len: %d\n",
+ req->cmd, req->cmd->common.command_id,
+ req->cmd->common.opcode,
+ le32_to_cpu(req->cmd->common.dptr.sgl.length));
+
+ nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
+ return -EAGAIN;
+ }
+
+ ret = nvmet_tcp_map_data(queue->cmd);
+ if (unlikely(ret)) {
+ pr_err("queue %d: failed to map data\n", queue->idx);
+ if (nvmet_tcp_has_inline_data(queue->cmd))
+ nvmet_tcp_fatal_error(queue);
+ else
+ nvmet_req_complete(req, ret);
+ ret = -EAGAIN;
+ goto out;
+ }
+
+ if (nvmet_tcp_need_data_in(queue->cmd)) {
+ if (nvmet_tcp_has_inline_data(queue->cmd)) {
+ queue->rcv_state = NVMET_TCP_RECV_DATA;
+ nvmet_tcp_map_pdu_iovec(queue->cmd);
+ return 0;
+ }
+ /* send back R2T */
+ nvmet_tcp_queue_response(&queue->cmd->req);
+ goto out;
+ }
+
+ nvmet_req_execute(&queue->cmd->req);
+out:
+ nvmet_prepare_receive_pdu(queue);
+ return ret;
+}
+
+static const u8 nvme_tcp_pdu_sizes[] = {
+ [nvme_tcp_icreq] = sizeof(struct nvme_tcp_icreq_pdu),
+ [nvme_tcp_cmd] = sizeof(struct nvme_tcp_cmd_pdu),
+ [nvme_tcp_h2c_data] = sizeof(struct nvme_tcp_data_pdu),
+};
+
+static inline u8 nvmet_tcp_pdu_size(u8 type)
+{
+ size_t idx = type;
+
+ return (idx < ARRAY_SIZE(nvme_tcp_pdu_sizes) &&
+ nvme_tcp_pdu_sizes[idx]) ?
+ nvme_tcp_pdu_sizes[idx] : 0;
+}
+
+static inline bool nvmet_tcp_pdu_valid(u8 type)
+{
+ switch (type) {
+ case nvme_tcp_icreq:
+ case nvme_tcp_cmd:
+ case nvme_tcp_h2c_data:
+ /* fallthru */
+ return true;
+ }
+
+ return false;
+}
+
+static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)
+{
+ struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
+ int len;
+ struct kvec iov;
+ struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
+
+recv:
+ iov.iov_base = (void *)&queue->pdu + queue->offset;
+ iov.iov_len = queue->left;
+ len = kernel_recvmsg(queue->sock, &msg, &iov, 1,
+ iov.iov_len, msg.msg_flags);
+ if (unlikely(len < 0))
+ return len;
+
+ queue->offset += len;
+ queue->left -= len;
+ if (queue->left)
+ return -EAGAIN;
+
+ if (queue->offset == sizeof(struct nvme_tcp_hdr)) {
+ u8 hdgst = nvmet_tcp_hdgst_len(queue);
+
+ if (unlikely(!nvmet_tcp_pdu_valid(hdr->type))) {
+ pr_err("unexpected pdu type %d\n", hdr->type);
+ nvmet_tcp_fatal_error(queue);
+ return -EIO;
+ }
+
+ if (unlikely(hdr->hlen != nvmet_tcp_pdu_size(hdr->type))) {
+ pr_err("pdu %d bad hlen %d\n", hdr->type, hdr->hlen);
+ return -EIO;
+ }
+
+ queue->left = hdr->hlen - queue->offset + hdgst;
+ goto recv;
+ }
+
+ if (queue->hdr_digest &&
+ nvmet_tcp_verify_hdgst(queue, &queue->pdu, queue->offset)) {
+ nvmet_tcp_fatal_error(queue); /* fatal */
+ return -EPROTO;
+ }
+
+ if (queue->data_digest &&
+ nvmet_tcp_check_ddgst(queue, &queue->pdu)) {
+ nvmet_tcp_fatal_error(queue); /* fatal */
+ return -EPROTO;
+ }
+
+ return nvmet_tcp_done_recv_pdu(queue);
+}
+
+static void nvmet_tcp_prep_recv_ddgst(struct nvmet_tcp_cmd *cmd)
+{
+ struct nvmet_tcp_queue *queue = cmd->queue;
+
+ nvmet_tcp_ddgst(queue->rcv_hash, cmd);
+ queue->offset = 0;
+ queue->left = NVME_TCP_DIGEST_LENGTH;
+ queue->rcv_state = NVMET_TCP_RECV_DDGST;
+}
+
+static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
+{
+ struct nvmet_tcp_cmd *cmd = queue->cmd;
+ int ret;
+
+ while (msg_data_left(&cmd->recv_msg)) {
+ ret = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,
+ cmd->recv_msg.msg_flags);
+ if (ret <= 0)
+ return ret;
+
+ cmd->pdu_recv += ret;
+ cmd->rbytes_done += ret;
+ }
+
+ nvmet_tcp_unmap_pdu_iovec(cmd);
+
+ if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
+ cmd->rbytes_done == cmd->req.transfer_len) {
+ if (queue->data_digest) {
+ nvmet_tcp_prep_recv_ddgst(cmd);
+ return 0;
+ }
+ nvmet_req_execute(&cmd->req);
+ }
+
+ nvmet_prepare_receive_pdu(queue);
+ return 0;
+}
+
+static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
+{
+ struct nvmet_tcp_cmd *cmd = queue->cmd;
+ int ret;
+ struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
+ struct kvec iov = {
+ .iov_base = (void *)&cmd->recv_ddgst + queue->offset,
+ .iov_len = queue->left
+ };
+
+ ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
+ iov.iov_len, msg.msg_flags);
+ if (unlikely(ret < 0))
+ return ret;
+
+ queue->offset += ret;
+ queue->left -= ret;
+ if (queue->left)
+ return -EAGAIN;
+
+ if (queue->data_digest && cmd->exp_ddgst != cmd->recv_ddgst) {
+ pr_err("queue %d: cmd %d pdu (%d) data digest error: recv %#x expected %#x\n",
+ queue->idx, cmd->req.cmd->common.command_id,
+ queue->pdu.cmd.hdr.type, le32_to_cpu(cmd->recv_ddgst),
+ le32_to_cpu(cmd->exp_ddgst));
+ nvmet_tcp_finish_cmd(cmd);
+ nvmet_tcp_fatal_error(queue);
+ ret = -EPROTO;
+ goto out;
+ }
+
+ if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
+ cmd->rbytes_done == cmd->req.transfer_len)
+ nvmet_req_execute(&cmd->req);
+ ret = 0;
+out:
+ nvmet_prepare_receive_pdu(queue);
+ return ret;
+}
+
+static int nvmet_tcp_try_recv_one(struct nvmet_tcp_queue *queue)
+{
+ int result;
+
+ if (unlikely(queue->rcv_state == NVMET_TCP_RECV_ERR))
+ return 0;
+
+ if (queue->rcv_state == NVMET_TCP_RECV_PDU) {
+ result = nvmet_tcp_try_recv_pdu(queue);
+ if (result != 0)
+ goto done_recv;
+ }
+
+ if (queue->rcv_state == NVMET_TCP_RECV_DATA) {
+ result = nvmet_tcp_try_recv_data(queue);
+ if (result != 0)
+ goto done_recv;
+ }
+
+ if (queue->rcv_state == NVMET_TCP_RECV_DDGST) {
+ result = nvmet_tcp_try_recv_ddgst(queue);
+ if (result != 0)
+ goto done_recv;
+ }
+
+done_recv:
+ if (result < 0) {
+ if (result == -EAGAIN)
+ return 0;
+ return result;
+ }
+ return 1;
+}
+
+static int nvmet_tcp_try_recv(struct nvmet_tcp_queue *queue,
+ int budget, int *recvs)
+{
+ int i, ret = 0;
+
+ for (i = 0; i < budget; i++) {
+ ret = nvmet_tcp_try_recv_one(queue);
+ if (ret <= 0)
+ break;
+ (*recvs)++;
+ }
+
+ return ret;
+}
+
+static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue *queue)
+{
+ spin_lock(&queue->state_lock);
+ if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
+ queue->state = NVMET_TCP_Q_DISCONNECTING;
+ schedule_work(&queue->release_work);
+ }
+ spin_unlock(&queue->state_lock);
+}
+
+static void nvmet_tcp_io_work(struct work_struct *w)
+{
+ struct nvmet_tcp_queue *queue =
+ container_of(w, struct nvmet_tcp_queue, io_work);
+ bool pending;
+ int ret, ops = 0;
+
+ do {
+ pending = false;
+
+ ret = nvmet_tcp_try_recv(queue, NVMET_TCP_RECV_BUDGET, &ops);
+ if (ret > 0) {
+ pending = true;
+ } else if (ret < 0) {
+ if (ret == -EPIPE || ret == -ECONNRESET)
+ kernel_sock_shutdown(queue->sock, SHUT_RDWR);
+ else
+ nvmet_tcp_fatal_error(queue);
+ return;
+ }
+
+ ret = nvmet_tcp_try_send(queue, NVMET_TCP_SEND_BUDGET, &ops);
+ if (ret > 0) {
+ /* transmitted message/data */
+ pending = true;
+ } else if (ret < 0) {
+ if (ret == -EPIPE || ret == -ECONNRESET)
+ kernel_sock_shutdown(queue->sock, SHUT_RDWR);
+ else
+ nvmet_tcp_fatal_error(queue);
+ return;
+ }
+
+ } while (pending && ops < NVMET_TCP_IO_WORK_BUDGET);
+
+ /*
+ * We exahusted our budget, requeue our selves
+ */
+ if (pending)
+ queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
+}
+
+static int nvmet_tcp_alloc_cmd(struct nvmet_tcp_queue *queue,
+ struct nvmet_tcp_cmd *c)
+{
+ u8 hdgst = nvmet_tcp_hdgst_len(queue);
+
+ c->queue = queue;
+ c->req.port = queue->port->nport;
+
+ c->cmd_pdu = page_frag_alloc(&queue->pf_cache,
+ sizeof(*c->cmd_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
+ if (!c->cmd_pdu)
+ return -ENOMEM;
+ c->req.cmd = &c->cmd_pdu->cmd;
+
+ c->rsp_pdu = page_frag_alloc(&queue->pf_cache,
+ sizeof(*c->rsp_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
+ if (!c->rsp_pdu)
+ goto out_free_cmd;
+ c->req.rsp = &c->rsp_pdu->cqe;
+
+ c->data_pdu = page_frag_alloc(&queue->pf_cache,
+ sizeof(*c->data_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
+ if (!c->data_pdu)
+ goto out_free_rsp;
+
+ c->r2t_pdu = page_frag_alloc(&queue->pf_cache,
+ sizeof(*c->r2t_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
+ if (!c->r2t_pdu)
+ goto out_free_data;
+
+ c->recv_msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
+
+ list_add_tail(&c->entry, &queue->free_list);
+
+ return 0;
+out_free_data:
+ page_frag_free(c->data_pdu);
+out_free_rsp:
+ page_frag_free(c->rsp_pdu);
+out_free_cmd:
+ page_frag_free(c->cmd_pdu);
+ return -ENOMEM;
+}
+
+static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c)
+{
+ page_frag_free(c->r2t_pdu);
+ page_frag_free(c->data_pdu);
+ page_frag_free(c->rsp_pdu);
+ page_frag_free(c->cmd_pdu);
+}
+
+static int nvmet_tcp_alloc_cmds(struct nvmet_tcp_queue *queue)
+{
+ struct nvmet_tcp_cmd *cmds;
+ int i, ret = -EINVAL, nr_cmds = queue->nr_cmds;
+
+ cmds = kcalloc(nr_cmds, sizeof(struct nvmet_tcp_cmd), GFP_KERNEL);
+ if (!cmds)
+ goto out;
+
+ for (i = 0; i < nr_cmds; i++) {
+ ret = nvmet_tcp_alloc_cmd(queue, cmds + i);
+ if (ret)
+ goto out_free;
+ }
+
+ queue->cmds = cmds;
+
+ return 0;
+out_free:
+ while (--i >= 0)
+ nvmet_tcp_free_cmd(cmds + i);
+ kfree(cmds);
+out:
+ return ret;
+}
+
+static void nvmet_tcp_free_cmds(struct nvmet_tcp_queue *queue)
+{
+ struct nvmet_tcp_cmd *cmds = queue->cmds;
+ int i;
+
+ for (i = 0; i < queue->nr_cmds; i++)
+ nvmet_tcp_free_cmd(cmds + i);
+
+ nvmet_tcp_free_cmd(&queue->connect);
+ kfree(cmds);
+}
+
+static void nvmet_tcp_restore_socket_callbacks(struct nvmet_tcp_queue *queue)
+{
+ struct socket *sock = queue->sock;
+
+ write_lock_bh(&sock->sk->sk_callback_lock);
+ sock->sk->sk_data_ready = queue->data_ready;
+ sock->sk->sk_state_change = queue->state_change;
+ sock->sk->sk_write_space = queue->write_space;
+ sock->sk->sk_user_data = NULL;
+ write_unlock_bh(&sock->sk->sk_callback_lock);
+}
+
+static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd)
+{
+ nvmet_req_uninit(&cmd->req);
+ nvmet_tcp_unmap_pdu_iovec(cmd);
+ sgl_free(cmd->req.sg);
+}
+
+static void nvmet_tcp_uninit_data_in_cmds(struct nvmet_tcp_queue *queue)
+{
+ struct nvmet_tcp_cmd *cmd = queue->cmds;
+ int i;
+
+ for (i = 0; i < queue->nr_cmds; i++, cmd++) {
+ if (nvmet_tcp_need_data_in(cmd))
+ nvmet_tcp_finish_cmd(cmd);
+ }
+
+ if (!queue->nr_cmds && nvmet_tcp_need_data_in(&queue->connect)) {
+ /* failed in connect */
+ nvmet_tcp_finish_cmd(&queue->connect);
+ }
+}
+
+static void nvmet_tcp_release_queue_work(struct work_struct *w)
+{
+ struct nvmet_tcp_queue *queue =
+ container_of(w, struct nvmet_tcp_queue, release_work);
+
+ mutex_lock(&nvmet_tcp_queue_mutex);
+ list_del_init(&queue->queue_list);
+ mutex_unlock(&nvmet_tcp_queue_mutex);
+
+ nvmet_tcp_restore_socket_callbacks(queue);
+ flush_work(&queue->io_work);
+
+ nvmet_tcp_uninit_data_in_cmds(queue);
+ nvmet_sq_destroy(&queue->nvme_sq);
+ cancel_work_sync(&queue->io_work);
+ sock_release(queue->sock);
+ nvmet_tcp_free_cmds(queue);
+ if (queue->hdr_digest || queue->data_digest)
+ nvmet_tcp_free_crypto(queue);
+ ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
+
+ kfree(queue);
+}
+
+static void nvmet_tcp_data_ready(struct sock *sk)
+{
+ struct nvmet_tcp_queue *queue;
+
+ read_lock_bh(&sk->sk_callback_lock);
+ queue = sk->sk_user_data;
+ if (likely(queue))
+ queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
+ read_unlock_bh(&sk->sk_callback_lock);
+}
+
+static void nvmet_tcp_write_space(struct sock *sk)
+{
+ struct nvmet_tcp_queue *queue;
+
+ read_lock_bh(&sk->sk_callback_lock);
+ queue = sk->sk_user_data;
+ if (unlikely(!queue))
+ goto out;
+
+ if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
+ queue->write_space(sk);
+ goto out;
+ }
+
+ if (sk_stream_is_writeable(sk)) {
+ clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
+ queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
+ }
+out:
+ read_unlock_bh(&sk->sk_callback_lock);
+}
+
+static void nvmet_tcp_state_change(struct sock *sk)
+{
+ struct nvmet_tcp_queue *queue;
+
+ write_lock_bh(&sk->sk_callback_lock);
+ queue = sk->sk_user_data;
+ if (!queue)
+ goto done;
+
+ switch (sk->sk_state) {
+ case TCP_FIN_WAIT1:
+ case TCP_CLOSE_WAIT:
+ case TCP_CLOSE:
+ /* FALLTHRU */
+ sk->sk_user_data = NULL;
+ nvmet_tcp_schedule_release_queue(queue);
+ break;
+ default:
+ pr_warn("queue %d unhandled state %d\n",
+ queue->idx, sk->sk_state);
+ }
+done:
+ write_unlock_bh(&sk->sk_callback_lock);
+}
+
+static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
+{
+ struct socket *sock = queue->sock;
+ struct linger sol = { .l_onoff = 1, .l_linger = 0 };
+ int ret;
+
+ ret = kernel_getsockname(sock,
+ (struct sockaddr *)&queue->sockaddr);
+ if (ret < 0)
+ return ret;
+
+ ret = kernel_getpeername(sock,
+ (struct sockaddr *)&queue->sockaddr_peer);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Cleanup whatever is sitting in the TCP transmit queue on socket
+ * close. This is done to prevent stale data from being sent should
+ * the network connection be restored before TCP times out.
+ */
+ ret = kernel_setsockopt(sock, SOL_SOCKET, SO_LINGER,
+ (char *)&sol, sizeof(sol));
+ if (ret)
+ return ret;
+
+ write_lock_bh(&sock->sk->sk_callback_lock);
+ sock->sk->sk_user_data = queue;
+ queue->data_ready = sock->sk->sk_data_ready;
+ sock->sk->sk_data_ready = nvmet_tcp_data_ready;
+ queue->state_change = sock->sk->sk_state_change;
+ sock->sk->sk_state_change = nvmet_tcp_state_change;
+ queue->write_space = sock->sk->sk_write_space;
+ sock->sk->sk_write_space = nvmet_tcp_write_space;
+ write_unlock_bh(&sock->sk->sk_callback_lock);
+
+ return 0;
+}
+
+static int nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
+ struct socket *newsock)
+{
+ struct nvmet_tcp_queue *queue;
+ int ret;
+
+ queue = kzalloc(sizeof(*queue), GFP_KERNEL);
+ if (!queue)
+ return -ENOMEM;
+
+ INIT_WORK(&queue->release_work, nvmet_tcp_release_queue_work);
+ INIT_WORK(&queue->io_work, nvmet_tcp_io_work);
+ queue->sock = newsock;
+ queue->port = port;
+ queue->nr_cmds = 0;
+ spin_lock_init(&queue->state_lock);
+ queue->state = NVMET_TCP_Q_CONNECTING;
+ INIT_LIST_HEAD(&queue->free_list);
+ init_llist_head(&queue->resp_list);
+ INIT_LIST_HEAD(&queue->resp_send_list);
+
+ queue->idx = ida_simple_get(&nvmet_tcp_queue_ida, 0, 0, GFP_KERNEL);
+ if (queue->idx < 0) {
+ ret = queue->idx;
+ goto out_free_queue;
+ }
+
+ ret = nvmet_tcp_alloc_cmd(queue, &queue->connect);
+ if (ret)
+ goto out_ida_remove;
+
+ ret = nvmet_sq_init(&queue->nvme_sq);
+ if (ret)
+ goto out_free_connect;
+
+ port->last_cpu = cpumask_next_wrap(port->last_cpu,
+ cpu_online_mask, -1, false);
+ queue->cpu = port->last_cpu;
+ nvmet_prepare_receive_pdu(queue);
+
+ mutex_lock(&nvmet_tcp_queue_mutex);
+ list_add_tail(&queue->queue_list, &nvmet_tcp_queue_list);
+ mutex_unlock(&nvmet_tcp_queue_mutex);
+
+ ret = nvmet_tcp_set_queue_sock(queue);
+ if (ret)
+ goto out_destroy_sq;
+
+ queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
+
+ return 0;
+out_destroy_sq:
+ mutex_lock(&nvmet_tcp_queue_mutex);
+ list_del_init(&queue->queue_list);
+ mutex_unlock(&nvmet_tcp_queue_mutex);
+ nvmet_sq_destroy(&queue->nvme_sq);
+out_free_connect:
+ nvmet_tcp_free_cmd(&queue->connect);
+out_ida_remove:
+ ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
+out_free_queue:
+ kfree(queue);
+ return ret;
+}
+
+static void nvmet_tcp_accept_work(struct work_struct *w)
+{
+ struct nvmet_tcp_port *port =
+ container_of(w, struct nvmet_tcp_port, accept_work);
+ struct socket *newsock;
+ int ret;
+
+ while (true) {
+ ret = kernel_accept(port->sock, &newsock, O_NONBLOCK);
+ if (ret < 0) {
+ if (ret != -EAGAIN)
+ pr_warn("failed to accept err=%d\n", ret);
+ return;
+ }
+ ret = nvmet_tcp_alloc_queue(port, newsock);
+ if (ret) {
+ pr_err("failed to allocate queue\n");
+ sock_release(newsock);
+ }
+ }
+}
+
+static void nvmet_tcp_listen_data_ready(struct sock *sk)
+{
+ struct nvmet_tcp_port *port;
+
+ read_lock_bh(&sk->sk_callback_lock);
+ port = sk->sk_user_data;
+ if (!port)
+ goto out;
+
+ if (sk->sk_state == TCP_LISTEN)
+ schedule_work(&port->accept_work);
+out:
+ read_unlock_bh(&sk->sk_callback_lock);
+}
+
+static int nvmet_tcp_add_port(struct nvmet_port *nport)
+{
+ struct nvmet_tcp_port *port;
+ __kernel_sa_family_t af;
+ int opt, ret;
+
+ port = kzalloc(sizeof(*port), GFP_KERNEL);
+ if (!port)
+ return -ENOMEM;
+
+ switch (nport->disc_addr.adrfam) {
+ case NVMF_ADDR_FAMILY_IP4:
+ af = AF_INET;
+ break;
+ case NVMF_ADDR_FAMILY_IP6:
+ af = AF_INET6;
+ break;
+ default:
+ pr_err("address family %d not supported\n",
+ nport->disc_addr.adrfam);
+ ret = -EINVAL;
+ goto err_port;
+ }
+
+ ret = inet_pton_with_scope(&init_net, af, nport->disc_addr.traddr,
+ nport->disc_addr.trsvcid, &port->addr);
+ if (ret) {
+ pr_err("malformed ip/port passed: %s:%s\n",
+ nport->disc_addr.traddr, nport->disc_addr.trsvcid);
+ goto err_port;
+ }
+
+ port->nport = nport;
+ port->last_cpu = -1;
+ INIT_WORK(&port->accept_work, nvmet_tcp_accept_work);
+ if (port->nport->inline_data_size < 0)
+ port->nport->inline_data_size = NVMET_TCP_DEF_INLINE_DATA_SIZE;
+
+ ret = sock_create(port->addr.ss_family, SOCK_STREAM,
+ IPPROTO_TCP, &port->sock);
+ if (ret) {
+ pr_err("failed to create a socket\n");
+ goto err_port;
+ }
+
+ port->sock->sk->sk_user_data = port;
+ port->data_ready = port->sock->sk->sk_data_ready;
+ port->sock->sk->sk_data_ready = nvmet_tcp_listen_data_ready;
+
+ opt = 1;
+ ret = kernel_setsockopt(port->sock, IPPROTO_TCP,
+ TCP_NODELAY, (char *)&opt, sizeof(opt));
+ if (ret) {
+ pr_err("failed to set TCP_NODELAY sock opt %d\n", ret);
+ goto err_sock;
+ }
+
+ ret = kernel_setsockopt(port->sock, SOL_SOCKET, SO_REUSEADDR,
+ (char *)&opt, sizeof(opt));
+ if (ret) {
+ pr_err("failed to set SO_REUSEADDR sock opt %d\n", ret);
+ goto err_sock;
+ }
+
+ ret = kernel_bind(port->sock, (struct sockaddr *)&port->addr,
+ sizeof(port->addr));
+ if (ret) {
+ pr_err("failed to bind port socket %d\n", ret);
+ goto err_sock;
+ }
+
+ ret = kernel_listen(port->sock, 128);
+ if (ret) {
+ pr_err("failed to listen %d on port sock\n", ret);
+ goto err_sock;
+ }
+
+ nport->priv = port;
+ pr_info("enabling port %d (%pISpc)\n",
+ le16_to_cpu(nport->disc_addr.portid), &port->addr);
+
+ return 0;
+
+err_sock:
+ sock_release(port->sock);
+err_port:
+ kfree(port);
+ return ret;
+}
+
+static void nvmet_tcp_remove_port(struct nvmet_port *nport)
+{
+ struct nvmet_tcp_port *port = nport->priv;
+
+ write_lock_bh(&port->sock->sk->sk_callback_lock);
+ port->sock->sk->sk_data_ready = port->data_ready;
+ port->sock->sk->sk_user_data = NULL;
+ write_unlock_bh(&port->sock->sk->sk_callback_lock);
+ cancel_work_sync(&port->accept_work);
+
+ sock_release(port->sock);
+ kfree(port);
+}
+
+static void nvmet_tcp_delete_ctrl(struct nvmet_ctrl *ctrl)
+{
+ struct nvmet_tcp_queue *queue;
+
+ mutex_lock(&nvmet_tcp_queue_mutex);
+ list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
+ if (queue->nvme_sq.ctrl == ctrl)
+ kernel_sock_shutdown(queue->sock, SHUT_RDWR);
+ mutex_unlock(&nvmet_tcp_queue_mutex);
+}
+
+static u16 nvmet_tcp_install_queue(struct nvmet_sq *sq)
+{
+ struct nvmet_tcp_queue *queue =
+ container_of(sq, struct nvmet_tcp_queue, nvme_sq);
+
+ if (sq->qid == 0) {
+ /* Let inflight controller teardown complete */
+ flush_scheduled_work();
+ }
+
+ queue->nr_cmds = sq->size * 2;
+ if (nvmet_tcp_alloc_cmds(queue))
+ return NVME_SC_INTERNAL;
+ return 0;
+}
+
+static void nvmet_tcp_disc_port_addr(struct nvmet_req *req,
+ struct nvmet_port *nport, char *traddr)
+{
+ struct nvmet_tcp_port *port = nport->priv;
+
+ if (inet_addr_is_any((struct sockaddr *)&port->addr)) {
+ struct nvmet_tcp_cmd *cmd =
+ container_of(req, struct nvmet_tcp_cmd, req);
+ struct nvmet_tcp_queue *queue = cmd->queue;
+
+ sprintf(traddr, "%pISc", (struct sockaddr *)&queue->sockaddr);
+ } else {
+ memcpy(traddr, nport->disc_addr.traddr, NVMF_TRADDR_SIZE);
+ }
+}
+
+static struct nvmet_fabrics_ops nvmet_tcp_ops = {
+ .owner = THIS_MODULE,
+ .type = NVMF_TRTYPE_TCP,
+ .msdbd = 1,
+ .has_keyed_sgls = 0,
+ .add_port = nvmet_tcp_add_port,
+ .remove_port = nvmet_tcp_remove_port,
+ .queue_response = nvmet_tcp_queue_response,
+ .delete_ctrl = nvmet_tcp_delete_ctrl,
+ .install_queue = nvmet_tcp_install_queue,
+ .disc_traddr = nvmet_tcp_disc_port_addr,
+};
+
+static int __init nvmet_tcp_init(void)
+{
+ int ret;
+
+ nvmet_tcp_wq = alloc_workqueue("nvmet_tcp_wq", WQ_HIGHPRI, 0);
+ if (!nvmet_tcp_wq)
+ return -ENOMEM;
+
+ ret = nvmet_register_transport(&nvmet_tcp_ops);
+ if (ret)
+ goto err;
+
+ return 0;
+err:
+ destroy_workqueue(nvmet_tcp_wq);
+ return ret;
+}
+
+static void __exit nvmet_tcp_exit(void)
+{
+ struct nvmet_tcp_queue *queue;
+
+ nvmet_unregister_transport(&nvmet_tcp_ops);
+
+ flush_scheduled_work();
+ mutex_lock(&nvmet_tcp_queue_mutex);
+ list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
+ kernel_sock_shutdown(queue->sock, SHUT_RDWR);
+ mutex_unlock(&nvmet_tcp_queue_mutex);
+ flush_scheduled_work();
+
+ destroy_workqueue(nvmet_tcp_wq);
+}
+
+module_init(nvmet_tcp_init);
+module_exit(nvmet_tcp_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("nvmet-transport-3"); /* 3 == NVMF_TRTYPE_TCP */
--
2.17.1
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  Last update: 2018-12-04 02:52    [W:0.147 / U:5.472 seconds]
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