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+/*
+ * InfiniBand Network Block Driver
+ *
+ * Copyright (c) 2014 - 2017 ProfitBricks GmbH. All rights reserved.
+ * Authors: Fabian Holler < mail@fholler.de>
+ * Jack Wang <jinpu.wang@profitbricks.com>
+ * Kleber Souza <kleber.souza@profitbricks.com>
+ * Danil Kipnis <danil.kipnis@profitbricks.com>
+ * Roman Pen <roman.penyaev@profitbricks.com>
+ * Milind Dumbare <Milind.dumbare@gmail.com>
+ *
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions, and the following disclaimer,
+ * without modification.
+ * 2. Redistributions in binary form must reproduce at minimum a disclaimer
+ * substantially similar to the "NO WARRANTY" disclaimer below
+ * ("Disclaimer") and any redistribution must be conditioned upon
+ * including a substantially similar Disclaimer requirement for further
+ * binary redistribution.
+ * 3. Neither the names of the above-listed copyright holders nor the names
+ * of any contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * NO WARRANTY
+ * 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 MERCHANTIBILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/hdreg.h> /* for hd_geometry */
+#include <linux/scatterlist.h>
+#include <linux/idr.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <rdma/ib.h>
+#include <uapi/linux/in6.h>
+
+#include "ibnbd_clt.h"
+#include "ibnbd_clt_sysfs.h"
+#include "../ibnbd_inc/ibnbd.h"
+#include <rdma/ibtrs.h>
+
+MODULE_AUTHOR("ibnbd@profitbricks.com");
+MODULE_DESCRIPTION("InfiniBand Network Block Device Client");
+MODULE_VERSION(__stringify(IBNBD_VER));
+MODULE_LICENSE("GPL");
+
+static int ibnbd_client_major;
+static DEFINE_IDR(g_index_idr);
+static DEFINE_RWLOCK(g_index_lock);
+static DEFINE_SPINLOCK(sess_lock);
+static DEFINE_SPINLOCK(dev_lock);
+static LIST_HEAD(session_list);
+static LIST_HEAD(devs_list);
+static DECLARE_WAIT_QUEUE_HEAD(sess_list_waitq);
+static struct ibtrs_clt_ops ops;
+
+static bool softirq_enable;
+module_param(softirq_enable, bool, 0444);
+MODULE_PARM_DESC(softirq_enable, "finish request in softirq_fn."
+ " (default: 0)");
+/*
+ * Maximum number of partitions an instance can have.
+ * 6 bits = 64 minors = 63 partitions (one minor is used for the device itself)
+ */
+#define IBNBD_PART_BITS 6
+#define KERNEL_SECTOR_SIZE 512
+
+inline bool ibnbd_clt_dev_is_open(struct ibnbd_dev *dev)
+{
+ return dev->dev_state == DEV_STATE_OPEN;
+}
+
+static void ibnbd_clt_put_dev(struct ibnbd_dev *dev)
+{
+ if (!atomic_dec_if_positive(&dev->refcount)) {
+ write_lock(&g_index_lock);
+ idr_remove(&g_index_idr, dev->clt_device_id);
+ write_unlock(&g_index_lock);
+ kfree(dev->hw_queues);
+ kfree(dev->close_compl);
+ ibnbd_clt_put_sess(dev->sess);
+ kfree(dev);
+ }
+}
+
+static int ibnbd_clt_get_dev(struct ibnbd_dev *dev)
+{
+ return atomic_inc_not_zero(&dev->refcount);
+}
+
+static struct ibnbd_dev *g_get_dev(int dev_id)
+{
+ struct ibnbd_dev *dev;
+
+ read_lock(&g_index_lock);
+ dev = idr_find(&g_index_idr, dev_id);
+ if (!dev)
+ dev = ERR_PTR(-ENXIO);
+ read_unlock(&g_index_lock);
+
+ return dev;
+}
+
+static void ibnbd_clt_set_dev_attr(struct ibnbd_dev *dev,
+ const struct ibnbd_msg_open_rsp *rsp)
+{
+ dev->device_id = rsp->device_id;
+ dev->nsectors = rsp->nsectors;
+ dev->logical_block_size = rsp->logical_block_size;
+ dev->physical_block_size = rsp->physical_block_size;
+ dev->max_write_same_sectors = rsp->max_write_same_sectors;
+ dev->max_discard_sectors = rsp->max_discard_sectors;
+ dev->discard_zeroes_data = rsp->discard_zeroes_data;
+ dev->discard_granularity = rsp->discard_granularity;
+ dev->discard_alignment = rsp->discard_alignment;
+ dev->secure_discard = rsp->secure_discard;
+ dev->rotational = rsp->rotational;
+ dev->remote_io_mode = rsp->io_mode;
+
+ if (dev->remote_io_mode == IBNBD_FILEIO) {
+ dev->max_hw_sectors = dev->sess->max_io_size /
+ rsp->logical_block_size;
+ dev->max_segments = BMAX_SEGMENTS;
+ } else {
+ dev->max_hw_sectors = dev->sess->max_io_size /
+ rsp->logical_block_size <
+ rsp->max_hw_sectors ?
+ dev->sess->max_io_size /
+ rsp->logical_block_size : rsp->max_hw_sectors;
+ dev->max_segments = rsp->max_segments > BMAX_SEGMENTS ?
+ BMAX_SEGMENTS : rsp->max_segments;
+ }
+}
+
+static void ibnbd_clt_revalidate_disk(struct ibnbd_dev *dev,
+ size_t new_nsectors)
+{
+ int err = 0;
+
+ INFO(dev, "Device size changed from %zu to %zu sectors\n",
+ dev->nsectors, new_nsectors);
+ dev->nsectors = new_nsectors;
+ set_capacity(dev->gd,
+ dev->nsectors * (dev->logical_block_size /
+ KERNEL_SECTOR_SIZE));
+ err = revalidate_disk(dev->gd);
+ if (err)
+ ERR(dev, "Failed to change device size from"
+ " %zu to %zu, errno: %d\n", dev->nsectors,
+ new_nsectors, err);
+}
+
+static void process_msg_sess_info_rsp(struct ibnbd_session *sess,
+ struct ibnbd_msg_sess_info_rsp *msg)
+{
+ sess->ver = min_t(u8, msg->ver, IBNBD_VERSION);
+ DEB("Session to %s (%s) using protocol version %d (client version: %d,"
+ " server version: %d)\n", sess->str_addr, sess->hostname, sess->ver,
+ IBNBD_VERSION, msg->ver);
+}
+
+static int process_msg_open_rsp(struct ibnbd_session *sess,
+ struct ibnbd_msg_open_rsp *rsp)
+{
+ struct ibnbd_dev *dev;
+ int err = 0;
+
+ dev = g_get_dev(rsp->clt_device_id);
+ if (IS_ERR(dev)) {
+ ERR_NP("Open-Response message received from session %s"
+ " for unknown device (id: %d)\n", sess->str_addr,
+ rsp->clt_device_id);
+ return -ENOENT;
+ }
+
+ if (!ibnbd_clt_get_dev(dev)) {
+ ERR_NP("Failed to process Open-Response message from session"
+ " %s, unable to get reference to device (id: %d)",
+ sess->str_addr, rsp->clt_device_id);
+ return -ENOENT;
+ }
+
+ mutex_lock(&dev->lock);
+
+ if (dev->dev_state == DEV_STATE_UNMAPPED) {
+ INFO(dev, "Ignoring Open-Response message from server for "
+ " unmapped device\n");
+ err = -ENOENT;
+ goto out;
+ }
+
+ if (rsp->result) {
+ ERR(dev, "Server failed to open device for mapping, errno:"
+ " %d\n", rsp->result);
+ dev->open_errno = rsp->result;
+ if (dev->open_compl)
+ complete(dev->open_compl);
+ goto out;
+ }
+
+ if (dev->dev_state == DEV_STATE_CLOSED) {
+ /* if the device was remapped and the size changed in the
+ * meantime we need to revalidate it
+ */
+ if (dev->nsectors != rsp->nsectors)
+ ibnbd_clt_revalidate_disk(dev, (size_t)rsp->nsectors);
+ INFO(dev, "Device online, device remapped successfully\n");
+ }
+
+ ibnbd_clt_set_dev_attr(dev, rsp);
+
+ dev->dev_state = DEV_STATE_OPEN;
+ if (dev->open_compl)
+ complete(dev->open_compl);
+
+out:
+ mutex_unlock(&dev->lock);
+ ibnbd_clt_put_dev(dev);
+
+ return err;
+}
+
+static void process_msg_revalidate(struct ibnbd_session *sess,
+ struct ibnbd_msg_revalidate *msg)
+{
+ struct ibnbd_dev *dev;
+
+ dev = g_get_dev(msg->clt_device_id);
+ if (IS_ERR(dev)) {
+ ERR_NP("Received device revalidation message from session %s"
+ " for non-existent device (id %d)\n", sess->str_addr,
+ msg->clt_device_id);
+ return;
+ }
+
+ if (!ibnbd_clt_get_dev(dev)) {
+ ERR_NP("Failed to process device revalidation message from"
+ " session %s, unable to get reference to device"
+ " (id: %d)", sess->str_addr, msg->clt_device_id);
+ return;
+ }
+
+ mutex_lock(&dev->lock);
+
+ if (dev->dev_state == DEV_STATE_UNMAPPED) {
+ ERR(dev, "Received device revalidation message"
+ " for unmapped device\n");
+ goto out;
+ }
+
+ if (dev->nsectors != msg->nsectors &&
+ dev->dev_state == DEV_STATE_OPEN) {
+ ibnbd_clt_revalidate_disk(dev, (size_t)msg->nsectors);
+ } else {
+ INFO(dev, "Ignoring device revalidate message, "
+ "current device size is the same as in the "
+ "revalidate message, %llu sectors\n", msg->nsectors);
+ }
+
+out:
+ mutex_unlock(&dev->lock);
+ ibnbd_clt_put_dev(dev);
+}
+
+static int send_msg_close(struct ibtrs_session *sess, u32 device_id)
+{
+ struct ibnbd_msg_close msg;
+ struct kvec vec = {
+ .iov_base = &msg,
+ .iov_len = sizeof(msg)
+ };
+
+ msg.hdr.type = IBNBD_MSG_CLOSE;
+ msg.device_id = device_id;
+
+ return ibtrs_clt_send(sess, &vec, 1);
+}
+
+static void ibnbd_clt_recv(void *priv, const void *msg, size_t len)
+{
+ const struct ibnbd_msg_hdr *hdr = msg;
+ struct ibnbd_session *sess = priv;
+
+ if (unlikely(WARN_ON(!hdr) || ibnbd_validate_message(msg, len)))
+ return;
+
+ print_hex_dump_debug("", DUMP_PREFIX_OFFSET, 8, 1, msg, len, true);
+
+ switch (hdr->type) {
+ case IBNBD_MSG_SESS_INFO_RSP: {
+ struct ibnbd_msg_sess_info_rsp *rsp =
+ (struct ibnbd_msg_sess_info_rsp *)msg;
+
+ process_msg_sess_info_rsp(sess, rsp);
+ if (sess->sess_info_compl)
+ complete(sess->sess_info_compl);
+ break;
+ }
+ case IBNBD_MSG_OPEN_RSP: {
+ int err;
+ struct ibnbd_msg_open_rsp *rsp =
+ (struct ibnbd_msg_open_rsp *)msg;
+
+ if (process_msg_open_rsp(sess, rsp) && !rsp->result) {
+ ERR_NP("Failed to process open response message from"
+ " server, sending close message for dev id:"
+ " %u\n", rsp->device_id);
+
+ err = send_msg_close(sess->sess, rsp->device_id);
+ if (err)
+ ERR_NP("Failed to send close msg for device"
+ " with id: %u, errno: %d\n",
+ rsp->device_id, err);
+ }
+
+ break;
+ }
+ case IBNBD_MSG_CLOSE_RSP: {
+ struct ibnbd_dev *dev;
+ struct ibnbd_msg_close_rsp *rsp =
+ (struct ibnbd_msg_close_rsp *)msg;
+
+ dev = g_get_dev(rsp->clt_device_id);
+ if (IS_ERR(dev)) {
+ ERR_NP("Close-Response message received from session %s"
+ " for unknown device (id: %u)\n", sess->str_addr,
+ rsp->clt_device_id);
+ break;
+ }
+ if (dev->close_compl && dev->dev_state == DEV_STATE_UNMAPPED)
+ complete(dev->close_compl);
+
+ break;
+ }
+ case IBNBD_MSG_REVAL:
+ process_msg_revalidate(sess,
+ (struct ibnbd_msg_revalidate *)msg);
+ break;
+ default:
+ ERR_NP("IBNBD message with unknown type %d received from"
+ " session %s\n", hdr->type, sess->str_addr);
+ break;
+ }
+}
+
+static void ibnbd_blk_delay_work(struct work_struct *work)
+{
+ struct ibnbd_dev *dev;
+
+ dev = container_of(work, struct ibnbd_dev, rq_delay_work.work);
+ spin_lock_irq(dev->queue->queue_lock);
+ blk_start_queue(dev->queue);
+ spin_unlock_irq(dev->queue->queue_lock);
+}
+
+/**
+ * What is the difference between this and original blk_delay_queue() ?
+ * Here the stop queue flag is cleared, so we are like MQ.
+ */
+static void ibnbd_blk_delay_queue(struct ibnbd_dev *dev, unsigned long msecs)
+{
+ int cpu = get_cpu();
+
+ kblockd_schedule_delayed_work_on(cpu, &dev->rq_delay_work,
+ msecs_to_jiffies(msecs));
+ put_cpu();
+}
+
+static inline void ibnbd_dev_requeue(struct ibnbd_queue *q)
+{
+ struct ibnbd_dev *dev = q->dev;
+
+ if (dev->queue_mode == BLK_MQ) {
+ if (WARN_ON(!q->hctx))
+ return;
+ blk_mq_delay_queue(q->hctx, 0);
+ } else if (dev->queue_mode == BLK_RQ) {
+ ibnbd_blk_delay_queue(q->dev, 0);
+ } else {
+ WARN(1, "We support requeueing only for RQ or MQ");
+ }
+}
+
+enum {
+ IBNBD_DELAY_10ms = 10,
+ IBNBD_DELAY_IFBUSY = -1,
+};
+
+/**
+ * ibnbd_get_cpu_qlist() - finds a list with HW queues to be requeued
+ *
+ * Description:
+ * Each CPU has a list of HW queues, which needs to be requeed. If a list
+ * is not empty - it is marked with a bit. This function finds first
+ * set bit in a bitmap and returns corresponding CPU list.
+ */
+static struct ibnbd_cpu_qlist *ibnbd_get_cpu_qlist(struct ibnbd_session *sess,
+ int cpu)
+{
+ int bit;
+
+ /* First half */
+ bit = find_next_bit(sess->cpu_queues_bm, nr_cpu_ids, cpu);
+ if (bit < nr_cpu_ids) {
+ return per_cpu_ptr(sess->cpu_queues, bit);
+ } else if (cpu != 0) {
+ /* Second half */
+ bit = find_next_bit(sess->cpu_queues_bm, cpu, 0);
+ if (bit < cpu)
+ return per_cpu_ptr(sess->cpu_queues, bit);
+ }
+
+ return NULL;
+}
+
+static inline int nxt_cpu(int cpu)
+{
+ return (cpu + 1) % NR_CPUS;
+}
+
+/**
+ * get_cpu_rr_var() - returns pointer to percpu var containing last cpu requeued
+ *
+ * It also sets the var to the current cpu if the var was never set before
+ * (== -1).
+ */
+#define get_cpu_rr_var(percpu) \
+({ \
+ int *cpup; \
+ \
+ cpup = &get_cpu_var(*percpu); \
+ if (unlikely(*cpup < 0)) \
+ *cpup = smp_processor_id(); \
+ cpup; \
+})
+
+/**
+ * ibnbd_requeue_if_needed() - requeue if CPU queue is marked as non empty
+ *
+ * Description:
+ * Each CPU has it's own list of HW queues, which should be requeued.
+ * Function finds such list with HW queues, takes a list lock, picks up
+ * the first HW queue out of the list and requeues it.
+ *
+ * Return:
+ * True if the queue was requeued, false otherwise.
+ *
+ * Context:
+ * Does not matter.
+ */
+static inline bool ibnbd_requeue_if_needed(struct ibnbd_session *sess)
+{
+ struct ibnbd_queue *q = NULL;
+ struct ibnbd_cpu_qlist *cpu_q;
+ unsigned long flags;
+ int cpuv;
+
+ int *uninitialized_var(cpup);
+
+ /*
+ * To keep fairness and not to let other queues starve we always
+ * try to wake up someone else in round-robin manner. That of course
+ * increases latency but queues always have a chance to be executed.
+ */
+ cpup = get_cpu_rr_var(sess->cpu_rr);
+ cpuv = (*cpup + 1) % num_online_cpus();
+ for (cpu_q = ibnbd_get_cpu_qlist(sess, cpuv); cpu_q;
+ cpu_q = ibnbd_get_cpu_qlist(sess, nxt_cpu(cpu_q->cpu))) {
+ if (!spin_trylock_irqsave(&cpu_q->requeue_lock, flags))
+ continue;
+ if (likely(test_bit(cpu_q->cpu, sess->cpu_queues_bm))) {
+ q = list_first_entry_or_null(&cpu_q->requeue_list,
+ typeof(*q), requeue_list);
+ if (WARN_ON(!q))
+ goto clear_bit;
+ list_del_init(&q->requeue_list);
+ clear_bit_unlock(0, &q->in_list);
+
+ if (list_empty(&cpu_q->requeue_list)) {
+ /* Clear bit if nothing is left */
+clear_bit:
+ clear_bit(cpu_q->cpu, sess->cpu_queues_bm);
+ }
+ }
+ spin_unlock_irqrestore(&cpu_q->requeue_lock, flags);
+
+ if (q)
+ break;
+ }
+
+ /**
+ * Saves the CPU that is going to be requeued on the per-cpu var. Just
+ * incrementing it doesn't work because ibnbd_get_cpu_qlist() will
+ * always return the first CPU with something on the queue list when the
+ * value stored on the var is greater than the last CPU with something
+ * on the list.
+ */
+ if (cpu_q)
+ *cpup = cpu_q->cpu;
+ put_cpu_var(sess->cpu_rr);
+
+ if (q)
+ ibnbd_dev_requeue(q);
+
+ return !!q;
+}
+
+/**
+ * ibnbd_requeue_all_if_idle() - requeue all queues left in the list if
+ * session is idling (there are no requests in-flight).
+ *
+ * Description:
+ * This function tries to rerun all stopped queues if there are no
+ * requests in-flight anymore. This function tries to solve an obvious
+ * problem, when number of tags < than number of queues (hctx), which
+ * are stopped and put to sleep. If last tag, which has been just put,
+ * does not wake up all left queues (hctxs), IO requests hang forever.
+ *
+ * That can happen when all number of tags, say N, have been exhausted
+ * from one CPU, and we have many block devices per session, say M.
+ * Each block device has it's own queue (hctx) for each CPU, so eventually
+ * we can put that number of queues (hctxs) to sleep: M x NR_CPUS.
+ * If number of tags N < M x NR_CPUS finally we will get an IO hang.
+ *
+ * To avoid this hang last caller of ibnbd_put_tag() (last caller is the
+ * one who observes sess->busy == 0) must wake up all remaining queues.
+ *
+ * Context:
+ * Does not matter.
+ */
+static inline void ibnbd_requeue_all_if_idle(struct ibnbd_session *sess)
+{
+ bool requeued;
+
+ do {
+ requeued = ibnbd_requeue_if_needed(sess);
+ } while (atomic_read(&sess->busy) == 0 && requeued);
+}
+
+static struct ibtrs_tag *ibnbd_get_tag(struct ibnbd_session *sess, int cpu,
+ size_t tag_bytes, int wait)
+{
+ struct ibtrs_tag *tag;
+
+ tag = ibtrs_get_tag(sess->sess, cpu, tag_bytes,
+ wait ? IBTRS_TAG_WAIT : IBTRS_TAG_NOWAIT);
+ if (likely(tag))
+ /* We have a subtle rare case here, when all tags can be
+ * consumed before busy counter increased. This is safe,
+ * because loser will get NULL as a tag, observe 0 busy
+ * counter and immediately restart the queue himself.
+ */
+ atomic_inc(&sess->busy);
+
+ return tag;
+}
+
+static void ibnbd_put_tag(struct ibnbd_session *sess, struct ibtrs_tag *tag)
+{
+ ibtrs_put_tag(sess->sess, tag);
+ atomic_dec(&sess->busy);
+ /* Paired with ibnbd_dev_add_to_requeue(). Decrement first
+ * and then check queue bits.
+ */
+ smp_mb__after_atomic();
+ ibnbd_requeue_all_if_idle(sess);
+}
+
+static struct ibnbd_iu *ibnbd_get_iu(struct ibnbd_session *sess,
+ size_t tag_bytes, int wait)
+{
+ struct ibnbd_iu *iu;
+ struct ibtrs_tag *tag;
+
+ tag = ibnbd_get_tag(sess, -1, tag_bytes,
+ wait ? IBTRS_TAG_WAIT : IBTRS_TAG_NOWAIT);
+ if (unlikely(!tag))
+ return NULL;
+ iu = ibtrs_tag_to_pdu(tag);
+ iu->tag = tag; /* yes, ibtrs_tag_from_pdu() can be nice here,
+ * but also we have to think about MQ mode
+ */
+
+ return iu;
+}
+
+static void ibnbd_put_iu(struct ibnbd_session *sess, struct ibnbd_iu *iu)
+{
+ ibnbd_put_tag(sess, iu->tag);
+}
+
+static void ibnbd_softirq_done_fn(struct request *rq)
+{
+ struct ibnbd_dev *dev = rq->rq_disk->private_data;
+ struct ibnbd_session *sess = dev->sess;
+ struct ibnbd_iu *iu;
+
+ switch (dev->queue_mode) {
+ case BLK_MQ:
+ iu = blk_mq_rq_to_pdu(rq);
+ ibnbd_put_tag(sess, iu->tag);
+ blk_mq_end_request(rq, iu->errno);
+ if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
+ __free_page(rq->special_vec.bv_page);
+ break;
+ case BLK_RQ:
+ iu = rq->special;
+ blk_end_request_all(rq, iu->errno);
+ if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
+ __free_page(rq->special_vec.bv_page);
+ break;
+ default:
+ WARN(true, "dev->queue_mode , contains unexpected"
+ " value: %d. Memory Corruption? Inflight I/O stalled!\n",
+ dev->queue_mode);
+ return;
+ }
+}
+
+static void ibnbd_clt_rdma_ev(void *priv, enum ibtrs_clt_rdma_ev ev, int errno)
+{
+ struct ibnbd_iu *iu = (struct ibnbd_iu *)priv;
+ struct ibnbd_dev *dev = iu->dev;
+ struct request *rq;
+ const int flags = iu->msg.rw;
+ bool is_read;
+
+ switch (dev->queue_mode) {
+ case BLK_MQ:
+ rq = iu->rq;
+ is_read = req_op(rq) == READ;
+ iu->errno = errno;
+ if (softirq_enable) {
+ blk_mq_complete_request(rq, errno);
+ } else {
+ ibnbd_put_tag(dev->sess, iu->tag);
+ blk_mq_end_request(rq, errno);
+
+ if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
+ __free_page(rq->special_vec.bv_page);
+
+ }
+ break;
+ case BLK_RQ:
+ rq = iu->rq;
+ is_read = req_op(rq) == READ;
+ iu->errno = errno;
+ if (softirq_enable) {
+ blk_complete_request(rq);
+ } else {
+ blk_end_request_all(rq, errno);
+ if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
+ __free_page(rq->special_vec.bv_page);
+ }
+ break;
+ default:
+ WARN(true, "dev->queue_mode , contains unexpected"
+ " value: %d. Memory Corruption? Inflight I/O stalled!\n",
+ dev->queue_mode);
+ return;
+ }
+
+ if (errno)
+ INFO_RL(dev, "%s I/O failed with status: %d, flags: 0x%x\n",
+ is_read ? "read" : "write", errno, flags);
+}
+
+static int send_msg_open(struct ibnbd_dev *dev)
+{
+ int err;
+ struct ibnbd_msg_open msg;
+ struct kvec vec = {
+ .iov_base = &msg,
+ .iov_len = sizeof(msg)
+ };
+
+ msg.hdr.type = IBNBD_MSG_OPEN;
+ msg.clt_device_id = dev->clt_device_id;
+ msg.access_mode = dev->access_mode;
+ msg.io_mode = dev->io_mode;
+ strlcpy(msg.dev_name, dev->pathname, sizeof(msg.dev_name));
+
+ err = ibtrs_clt_send(dev->sess->sess, &vec, 1);
+
+ return err;
+}
+
+static int send_msg_sess_info(struct ibnbd_session *sess)
+{
+ struct ibnbd_msg_sess_info msg;
+ struct kvec vec = {
+ .iov_base = &msg,
+ .iov_len = sizeof(msg)
+ };
+
+ msg.hdr.type = IBNBD_MSG_SESS_INFO;
+ msg.ver = IBNBD_VERSION;
+
+ return ibtrs_clt_send(sess->sess, &vec, 1);
+}
+
+int open_remote_device(struct ibnbd_dev *dev)
+{
+ int err;
+
+ err = send_msg_open(dev);
+ if (unlikely(err)) {
+ ERR(dev, "Failed to send open msg, err: %d\n", err);
+ return err;
+ }
+ return 0;
+}
+
+static int find_dev_cb(int id, void *ptr, void *data)
+{
+ struct ibnbd_dev *dev = ptr;
+ struct ibnbd_session *sess = data;
+
+ if (dev->sess == sess && dev->dev_state == DEV_STATE_INIT &&
+ dev->open_compl) {
+ dev->dev_state = DEV_STATE_INIT_CLOSED;
+ dev->open_errno = -ECOMM;
+ complete(dev->open_compl);
+ ERR(dev, "Device offline, session disconnected.\n");
+ } else if (dev->sess == sess && dev->dev_state == DEV_STATE_UNMAPPED &&
+ dev->close_compl) {
+ complete(dev->close_compl);
+ ERR(dev, "Device closed, session disconnected.\n");
+ }
+
+ return 0;
+}
+
+static void __set_dev_states_closed(struct ibnbd_session *sess)
+{
+ struct ibnbd_dev *dev;
+
+ list_for_each_entry(dev, &sess->devs_list, list) {
+ mutex_lock(&dev->lock);
+ dev->dev_state = DEV_STATE_CLOSED;
+ dev->open_errno = -ECOMM;
+ if (dev->open_compl)
+ complete(dev->open_compl);
+ ERR(dev, "Device offline, session disconnected.\n");
+ mutex_unlock(&dev->lock);
+ }
+ read_lock(&g_index_lock);
+ idr_for_each(&g_index_idr, find_dev_cb, sess);
+ read_unlock(&g_index_lock);
+}
+
+static int update_sess_info(struct ibnbd_session *sess)
+{
+ int err;
+
+ sess->sess_info_compl = kmalloc(sizeof(*sess->sess_info_compl),
+ GFP_KERNEL);
+ if (!sess->sess_info_compl) {
+ ERR_NP("Failed to allocate memory for completion for session"
+ " %s (%s)\n", sess->str_addr, sess->hostname);
+ return -ENOMEM;
+ }
+
+ init_completion(sess->sess_info_compl);
+
+ err = send_msg_sess_info(sess);
+ if (unlikely(err)) {
+ ERR_NP("Failed to send SESS_INFO message for session %s (%s)\n",
+ sess->str_addr, sess->hostname);
+ goto out;
+ }
+
+ /* wait for IBNBD_MSG_SESS_INFO_RSP from server */
+ wait_for_completion(sess->sess_info_compl);
+out:
+ kfree(sess->sess_info_compl);
+ sess->sess_info_compl = NULL;
+
+ return err;
+}
+
+static void reopen_worker(struct work_struct *work)
+{
+ struct ibnbd_work *w;
+ struct ibnbd_session *sess;
+ struct ibnbd_dev *dev;
+ int err;
+
+ w = container_of(work, struct ibnbd_work, work);
+ sess = w->sess;
+ kfree(w);
+
+ mutex_lock(&sess->lock);
+ if (sess->state == SESS_STATE_DESTROYED) {
+ mutex_unlock(&sess->lock);
+ return;
+ }
+ err = update_sess_info(sess);
+ if (unlikely(err))
+ goto out;
+ list_for_each_entry(dev, &sess->devs_list, list) {
+ INFO(dev, "session reconnected, remapping device\n");
+ open_remote_device(dev);
+ }
+out:
+ mutex_unlock(&sess->lock);
+
+ ibnbd_clt_put_sess(sess);
+}
+
+static int ibnbd_schedule_reopen(struct ibnbd_session *sess)
+{
+ struct ibnbd_work *w;
+
+ w = kmalloc(sizeof(*w), GFP_KERNEL);
+ if (!w) {
+ ERR_NP("Failed to allocate memory to schedule reopen of"
+ " devices for session %s\n", sess->str_addr);
+ return -ENOMEM;
+ }
+
+ if (WARN_ON(!ibnbd_clt_get_sess(sess))) {
+ kfree(w);
+ return -ENOENT;
+ }
+
+ w->sess = sess;
+ INIT_WORK(&w->work, reopen_worker);
+ schedule_work(&w->work);
+
+ return 0;
+}
+
+static void ibnbd_clt_sess_ev(void *priv, enum ibtrs_clt_sess_ev ev, int errno)
+{
+ struct ibnbd_session *sess = priv;
+ struct ibtrs_attrs attrs;
+
+ switch (ev) {
+ case IBTRS_CLT_SESS_EV_DISCONNECTED:
+ if (sess->sess_info_compl)
+ complete(sess->sess_info_compl);
+ mutex_lock(&sess->lock);
+ if (sess->state == SESS_STATE_DESTROYED) {
+ mutex_unlock(&sess->lock);
+ return;
+ }
+ sess->state = SESS_STATE_DISCONNECTED;
+ __set_dev_states_closed(sess);
+ mutex_unlock(&sess->lock);
+ break;
+ case IBTRS_CLT_SESS_EV_RECONNECT:
+ mutex_lock(&sess->lock);
+ if (sess->state == SESS_STATE_DESTROYED) {
+ /* This may happen if the session started to be closed
+ * before the reconnect event arrived. In this case, we
+ * just return and the session will be closed later
+ */
+ mutex_unlock(&sess->lock);
+ return;
+ }
+ sess->state = SESS_STATE_READY;
+
+ mutex_unlock(&sess->lock);
+ memset(&attrs, 0, sizeof(attrs));
+ ibtrs_clt_query(sess->sess, &attrs);
+ strlcpy(sess->hostname, attrs.hostname, sizeof(sess->hostname));
+ sess->max_io_size = attrs.max_io_size;
+ ibnbd_schedule_reopen(sess);
+ break;
+ case IBTRS_CLT_SESS_EV_MAX_RECONN_EXCEEDED:
+ INFO_NP("Reconnect attempts exceeded for session %s\n",
+ sess->str_addr);
+ break;
+ default:
+ ERR_NP("Unknown session event received (%d), session: (%s)\n",
+ ev, sess->str_addr);
+ }
+}
+
+static int ibnbd_cmp_sock_addr(const struct sockaddr_storage *a,
+ const struct sockaddr_storage *b)
+{
+ if (a->ss_family == b->ss_family) {
+ switch (a->ss_family) {
+ case AF_INET:
+ return memcmp(&((struct sockaddr_in *)a)->sin_addr,
+ &((struct sockaddr_in *)b)->sin_addr,
+ sizeof(struct in_addr));
+ case AF_INET6:
+ return memcmp(&((struct sockaddr_in6 *)a)->sin6_addr,
+ &((struct sockaddr_in6 *)b)->sin6_addr,
+ sizeof(struct in6_addr));
+ case AF_IB:
+ return memcmp(&((struct sockaddr_ib *)a)->sib_addr,
+ &((struct sockaddr_ib *)b)->sib_addr,
+ sizeof(struct ib_addr));
+ default:
+ ERR_NP("Unknown address family: %d\n", a->ss_family);
+ return -EINVAL;
+ }
+ } else {
+ return -1;
+ }
+}
+
+struct ibnbd_session *ibnbd_clt_find_sess(const struct sockaddr_storage *addr)
+{
+ struct ibnbd_session *sess;
+
+ spin_lock(&sess_lock);
+ list_for_each_entry(sess, &session_list, list)
+ if (!ibnbd_cmp_sock_addr(&sess->addr, addr)) {
+ spin_unlock(&sess_lock);
+ return sess;
+ }
+ spin_unlock(&sess_lock);
+
+ return NULL;
+}
+
+static void ibnbd_init_cpu_qlists(struct ibnbd_cpu_qlist __percpu *cpu_queues)
+{
+ unsigned int cpu;
+ struct ibnbd_cpu_qlist *cpu_q;
+
+ for_each_online_cpu(cpu) {
+ cpu_q = per_cpu_ptr(cpu_queues, cpu);
+
+ cpu_q->cpu = cpu;
+ INIT_LIST_HEAD(&cpu_q->requeue_list);
+ spin_lock_init(&cpu_q->requeue_lock);
+ }
+}
+
+static struct blk_mq_ops ibnbd_mq_ops;
+static int setup_mq_tags(struct ibnbd_session *sess)
+{
+ struct blk_mq_tag_set *tags = &sess->tag_set;
+
+ memset(tags, 0, sizeof(*tags));
+ tags->ops = &ibnbd_mq_ops;
+ tags->queue_depth = sess->queue_depth;
+ tags->numa_node = NUMA_NO_NODE;
+ tags->flags = BLK_MQ_F_SHOULD_MERGE |
+ BLK_MQ_F_SG_MERGE |
+ BLK_MQ_F_TAG_SHARED;
+ tags->cmd_size = sizeof(struct ibnbd_iu);
+ tags->nr_hw_queues = num_online_cpus();
+
+ return blk_mq_alloc_tag_set(tags);
+}
+
+static void destroy_mq_tags(struct ibnbd_session *sess)
+{
+ blk_mq_free_tag_set(&sess->tag_set);
+}
+
+struct ibnbd_session *ibnbd_create_session(const struct sockaddr_storage *addr)
+{
+ struct ibnbd_session *sess;
+ struct ibtrs_attrs attrs;
+ char str_addr[IBTRS_ADDRLEN];
+ int err;
+ int cpu;
+
+ err = ibtrs_addr_to_str(addr, str_addr, sizeof(str_addr));
+ if (err < 0) {
+ ERR_NP("Can't create session, invalid address\n");
+ return ERR_PTR(err);
+ }
+
+ DEB("Establishing session to %s\n", str_addr);
+
+ if (ibnbd_clt_find_sess(addr)) {
+ ERR_NP("Can't create session, session to %s already exists\n",
+ str_addr);
+ return ERR_PTR(-EEXIST);
+ }
+
+ sess = kzalloc_node(sizeof(*sess), GFP_KERNEL, NUMA_NO_NODE);
+ if (unlikely(!sess)) {
+ ERR_NP("Failed to create session to %s,"
+ " allocating session struct failed\n", str_addr);
+ return ERR_PTR(-ENOMEM);
+ }
+ sess->cpu_queues = alloc_percpu(struct ibnbd_cpu_qlist);
+ if (unlikely(!sess->cpu_queues)) {
+ ERR_NP("Failed to create session to %s,"
+ " alloc of percpu var (cpu_queues) failed\n", str_addr);
+ kvfree(sess);
+ return ERR_PTR(-ENOMEM);
+ }
+ ibnbd_init_cpu_qlists(sess->cpu_queues);
+
+ /**
+ * That is simple percpu variable which stores cpu indeces, which are
+ * incremented on each access. We need that for the sake of fairness
+ * to wake up queues in a round-robin manner.
+ */
+ sess->cpu_rr = alloc_percpu(int);
+ if (unlikely(!sess->cpu_rr)) {
+ ERR_NP("Failed to create session to %s,"
+ " alloc of percpu var (cpu_rr) failed\n", str_addr);
+ free_percpu(sess->cpu_queues);
+ kfree(sess);
+ return ERR_PTR(-ENOMEM);
+ }
+ for_each_online_cpu(cpu) {
+ *per_cpu_ptr(sess->cpu_rr, cpu) = -1;
+ }
+
+ memset(&attrs, 0, sizeof(attrs));
+ memcpy(&sess->addr, addr, sizeof(sess->addr));
+ strlcpy(sess->str_addr, str_addr, sizeof(sess->str_addr));
+
+ spin_lock(&sess_lock);
+ list_add(&sess->list, &session_list);
+ spin_unlock(&sess_lock);
+
+ atomic_set(&sess->busy, 0);
+ mutex_init(&sess->lock);
+ INIT_LIST_HEAD(&sess->devs_list);
+ bitmap_zero(sess->cpu_queues_bm, NR_CPUS);
+ kref_init(&sess->refcount);
+ sess->state = SESS_STATE_DISCONNECTED;
+
+ sess->sess = ibtrs_clt_open(addr, sizeof(struct ibnbd_iu), sess,
+ RECONNECT_DELAY, BMAX_SEGMENTS,
+ MAX_RECONNECTS);
+ if (!IS_ERR(sess->sess)) {
+ mutex_lock(&sess->lock);
+ sess->state = SESS_STATE_READY;
+ mutex_unlock(&sess->lock);
+ } else {
+ err = PTR_ERR(sess->sess);
+ goto out_free;
+ }
+
+ ibtrs_clt_query(sess->sess, &attrs);
+ strlcpy(sess->hostname, attrs.hostname, sizeof(sess->hostname));
+ sess->max_io_size = attrs.max_io_size;
+ sess->queue_depth = attrs.queue_depth;
+
+ err = setup_mq_tags(sess);
+ if (unlikely(err))
+ goto close_sess;
+
+ err = update_sess_info(sess);
+ if (unlikely(err))
+ goto destroy_tags;
+
+ return sess;
+
+destroy_tags:
+ destroy_mq_tags(sess);
+close_sess:
+ ibtrs_clt_close(sess->sess);
+out_free:
+ spin_lock(&sess_lock);
+ list_del(&sess->list);
+ spin_unlock(&sess_lock);
+ free_percpu(sess->cpu_queues);
+ free_percpu(sess->cpu_rr);
+ kfree(sess);
+ return ERR_PTR(err);
+}
+
+static void ibnbd_clt_destroy_session(struct ibnbd_session *sess)
+{
+ mutex_lock(&sess->lock);
+ sess->state = SESS_STATE_DESTROYED;
+
+ if (!list_empty(&sess->devs_list)) {
+ mutex_unlock(&sess->lock);
+ WRN_NP("Device list is not empty,"
+ " closing session to %s failed\n", sess->str_addr);
+ return;
+ }
+ mutex_unlock(&sess->lock);
+ ibtrs_clt_close(sess->sess);
+
+ destroy_mq_tags(sess);
+ spin_lock(&sess_lock);
+ list_del(&sess->list);
+ spin_unlock(&sess_lock);
+ wake_up(&sess_list_waitq);
+
+ free_percpu(sess->cpu_queues);
+ free_percpu(sess->cpu_rr);
+ kfree(sess);
+}
+
+void ibnbd_clt_sess_release(struct kref *ref)
+{
+ struct ibnbd_session *sess = container_of(ref, struct ibnbd_session,
+ refcount);
+
+ ibnbd_clt_destroy_session(sess);
+}
+
+static int ibnbd_client_open(struct block_device *block_device, fmode_t mode)
+{
+ struct ibnbd_dev *dev = block_device->bd_disk->private_data;
+
+ if (dev->read_only && (mode & FMODE_WRITE))
+ return -EPERM;
+
+ if (dev->dev_state == DEV_STATE_UNMAPPED ||
+ !ibnbd_clt_get_dev(dev))
+ return -EIO;
+
+ DEB("OPEN, name=%s, open_cnt=%d\n", dev->gd->disk_name,
+ atomic_read(&dev->refcount) - 1);
+
+ return 0;
+}
+
+static void ibnbd_client_release(struct gendisk *gen, fmode_t mode)
+{
+ struct ibnbd_dev *dev = gen->private_data;
+
+ DEB("RELEASE, name=%s, open_cnt %d\n", dev->gd->disk_name,
+ atomic_read(&dev->refcount) - 1);
+
+ ibnbd_clt_put_dev(dev);
+}
+
+static int ibnbd_client_getgeo(struct block_device *block_device,
+ struct hd_geometry *geo)
+{
+ u64 size;
+ struct ibnbd_dev *dev;
+
+ dev = block_device->bd_disk->private_data;
+ size = dev->size * (dev->logical_block_size / KERNEL_SECTOR_SIZE);
+ geo->cylinders = (size & ~0x3f) >> 6; /* size/64 */
+ geo->heads = 4;
+ geo->sectors = 16;
+ geo->start = 0;
+
+ return 0;
+}
+
+static const struct block_device_operations ibnbd_client_ops = {
+ .owner = THIS_MODULE,
+ .open = ibnbd_client_open,
+ .release = ibnbd_client_release,
+ .getgeo = ibnbd_client_getgeo
+};
+
+static size_t ibnbd_clt_get_sg_size(struct scatterlist *sglist, u32 len)
+{
+ struct scatterlist *sg;
+ size_t tsize = 0;
+ int i;
+
+ for_each_sg(sglist, sg, len, i)
+ tsize += sg->length;
+ return tsize;
+}
+
+static inline int ibnbd_clt_setup_discard(struct request *rq)
+{
+ struct page *page;
+
+ page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
+ if (!page)
+ return -ENOMEM;
+ rq->special_vec.bv_page = page;
+ rq->special_vec.bv_offset = 0;
+ rq->special_vec.bv_len = PAGE_SIZE;
+ rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
+ return 0;
+}
+
+static int ibnbd_client_xfer_request(struct ibnbd_dev *dev, struct request *rq,
+ struct ibnbd_iu *iu)
+{
+ int err;
+
+ unsigned int sg_cnt;
+ size_t size;
+ struct kvec vec;
+ struct ibtrs_session *sess = dev->sess->sess;
+ struct ibtrs_tag *tag = iu->tag;
+ struct scatterlist *sg = iu->sglist;
+
+ if (req_op(rq) == REQ_OP_DISCARD) {
+ err = ibnbd_clt_setup_discard(rq);
+ if (err)
+ return err;
+ }
+ sg_cnt = blk_rq_nr_phys_segments(rq);
+
+ if (sg_cnt == 0)
+ sg_mark_end(&sg[0]);
+ else
+ sg_mark_end(&sg[sg_cnt - 1]);
+
+ iu->rq = rq;
+ iu->dev = dev;
+ iu->msg.sector = blk_rq_pos(rq);
+ iu->msg.bi_size = blk_rq_bytes(rq);
+ iu->msg.rw = rq_cmd_to_ibnbd_io_flags(rq);
+
+ sg_cnt = blk_rq_map_sg(dev->queue, rq, sg);
+
+ iu->msg.hdr.type = IBNBD_MSG_IO;
+ iu->msg.device_id = dev->device_id;
+
+ size = ibnbd_clt_get_sg_size(sg, sg_cnt);
+ vec = (struct kvec) {
+ .iov_base = &iu->msg,
+ .iov_len = sizeof(iu->msg)
+ };
+
+ if (req_op(rq) == READ)
+ err = ibtrs_clt_request_rdma_write(sess, tag, iu, &vec, 1, size,
+ sg, sg_cnt);
+ else
+ err = ibtrs_clt_rdma_write(sess, tag, iu, &vec, 1, size, sg,
+ sg_cnt);
+ if (unlikely(err)) {
+ ERR_RL(dev, "IBTRS failed to transfer IO, errno: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+/**
+ * ibnbd_dev_add_to_requeue() - add device to requeue if session is busy
+ *
+ * Description:
+ * If session is busy, that means someone will requeue us when resources
+ * are freed. If session is not doing anything - device is not added to
+ * the list and @false is returned.
+ */
+static inline bool ibnbd_dev_add_to_requeue(struct ibnbd_dev *dev,
+ struct ibnbd_queue *q)
+{
+ struct ibnbd_session *sess = dev->sess;
+ struct ibnbd_cpu_qlist *cpu_q;
+ unsigned long flags;
+ bool added = true;
+ bool need_set;
+
+ cpu_q = get_cpu_ptr(sess->cpu_queues);
+ spin_lock_irqsave(&cpu_q->requeue_lock, flags);
+
+ if (likely(!test_and_set_bit_lock(0, &q->in_list))) {
+ if (WARN_ON(!list_empty(&q->requeue_list)))
+ goto unlock;
+
+ need_set = !test_bit(cpu_q->cpu, sess->cpu_queues_bm);
+ if (need_set) {
+ set_bit(cpu_q->cpu, sess->cpu_queues_bm);
+ /* Paired with ibnbd_put_tag(). Set a bit first
+ * and then observe the busy counter.
+ */
+ smp_mb__before_atomic();
+ }
+ if (likely(atomic_read(&sess->busy))) {
+ list_add_tail(&q->requeue_list, &cpu_q->requeue_list);
+ } else {
+ /* Very unlikely, but possible: busy counter was
+ * observed as zero. Drop all bits and return
+ * false to restart the queue by ourselves.
+ */
+ if (need_set)
+ clear_bit(cpu_q->cpu, sess->cpu_queues_bm);
+ clear_bit_unlock(0, &q->in_list);
+ added = false;
+ }
+ }
+unlock:
+ spin_unlock_irqrestore(&cpu_q->requeue_lock, flags);
+ put_cpu_ptr(sess->cpu_queues);
+
+ return added;
+}
+
+static void ibnbd_dev_kick_mq_queue(struct ibnbd_dev *dev,
+ struct blk_mq_hw_ctx *hctx,
+ int delay)
+{
+ struct ibnbd_queue *q = hctx->driver_data;
+
+ if (WARN_ON(dev->queue_mode != BLK_MQ))
+ return;
+ blk_mq_stop_hw_queue(hctx);
+
+ if (delay != IBNBD_DELAY_IFBUSY)
+ blk_mq_delay_queue(hctx, delay);
+ else if (unlikely(!ibnbd_dev_add_to_requeue(dev, q)))
+ /* If session is not busy we have to restart
+ * the queue ourselves.
+ */
+ blk_mq_delay_queue(hctx, IBNBD_DELAY_10ms);
+}
+
+static void ibnbd_dev_kick_queue(struct ibnbd_dev *dev, int delay)
+{
+ if (WARN_ON(dev->queue_mode != BLK_RQ))
+ return;
+ blk_stop_queue(dev->queue);
+
+ if (delay != IBNBD_DELAY_IFBUSY)
+ ibnbd_blk_delay_queue(dev, delay);
+ else if (unlikely(!ibnbd_dev_add_to_requeue(dev, dev->hw_queues)))
+ /* If session is not busy we have to restart
+ * the queue ourselves.
+ */
+ ibnbd_blk_delay_queue(dev, IBNBD_DELAY_10ms);
+}
+
+static int ibnbd_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
+{
+ struct request *rq = bd->rq;
+ struct ibnbd_dev *dev = rq->rq_disk->private_data;
+ struct ibnbd_iu *iu = blk_mq_rq_to_pdu(rq);
+ int err;
+
+ if (unlikely(!ibnbd_clt_dev_is_open(dev)))
+ return BLK_MQ_RQ_QUEUE_ERROR;
+
+ iu->tag = ibnbd_get_tag(dev->sess, hctx->next_cpu, blk_rq_bytes(rq),
+ IBTRS_TAG_NOWAIT);
+ if (unlikely(!iu->tag)) {
+ ibnbd_dev_kick_mq_queue(dev, hctx, IBNBD_DELAY_IFBUSY);
+ return BLK_MQ_RQ_QUEUE_BUSY;
+ }
+
+ blk_mq_start_request(rq);
+ err = ibnbd_client_xfer_request(dev, rq, iu);
+ if (likely(err == 0))
+ return BLK_MQ_RQ_QUEUE_OK;
+ if (unlikely(err == -EAGAIN || err == -ENOMEM)) {
+ ibnbd_dev_kick_mq_queue(dev, hctx, IBNBD_DELAY_10ms);
+ ibnbd_put_tag(dev->sess, iu->tag);
+ return BLK_MQ_RQ_QUEUE_BUSY;
+ }
+
+ ibnbd_put_tag(dev->sess, iu->tag);
+ return BLK_MQ_RQ_QUEUE_ERROR;
+}
+
+static int ibnbd_init_request(void *data, struct request *rq,
+ unsigned int hctx_idx, unsigned int request_idx,
+ unsigned int numa_node)
+{
+ struct ibnbd_iu *iu = blk_mq_rq_to_pdu(rq);
+
+ sg_init_table(iu->sglist, BMAX_SEGMENTS);
+ return 0;
+}
+
+static inline void ibnbd_init_hw_queue(struct ibnbd_dev *dev,
+ struct ibnbd_queue *q,
+ struct blk_mq_hw_ctx *hctx)
+{
+ INIT_LIST_HEAD(&q->requeue_list);
+ q->dev = dev;
+ q->hctx = hctx;
+}
+
+static void ibnbd_init_mq_hw_queues(struct ibnbd_dev *dev)
+{
+ int i;
+ struct blk_mq_hw_ctx *hctx;
+ struct ibnbd_queue *q;
+
+ queue_for_each_hw_ctx(dev->queue, hctx, i) {
+ q = &dev->hw_queues[i];
+ ibnbd_init_hw_queue(dev, q, hctx);
+ hctx->driver_data = q;
+ }
+}
+
+static struct blk_mq_ops ibnbd_mq_ops = {
+ .queue_rq = ibnbd_queue_rq,
+ .init_request = ibnbd_init_request,
+ .complete = ibnbd_softirq_done_fn,
+};
+
+static int index_to_minor(int index)
+{
+ return index << IBNBD_PART_BITS;
+}
+
+static int minor_to_index(int minor)
+{
+ return minor >> IBNBD_PART_BITS;
+}
+
+static int ibnbd_rq_prep_fn(struct request_queue *q, struct request *rq)
+{
+ struct ibnbd_dev *dev = q->queuedata;
+ struct ibnbd_iu *iu;
+
+ iu = ibnbd_get_iu(dev->sess, blk_rq_bytes(rq), IBTRS_TAG_NOWAIT);
+ if (likely(iu)) {
+ rq->special = iu;
+ rq->rq_flags |= RQF_DONTPREP;
+
+ return BLKPREP_OK;
+ }
+
+ ibnbd_dev_kick_queue(dev, IBNBD_DELAY_IFBUSY);
+ return BLKPREP_DEFER;
+}
+
+static void ibnbd_rq_unprep_fn(struct request_queue *q, struct request *rq)
+{
+ struct ibnbd_dev *dev = q->queuedata;
+
+ if (WARN_ON(!rq->special))
+ return;
+ ibnbd_put_iu(dev->sess, rq->special);
+ rq->special = NULL;
+ rq->rq_flags &= ~RQF_DONTPREP;
+}
+
+static void ibnbd_clt_request(struct request_queue *q)
+__must_hold(q->queue_lock)
+{
+ int err;
+ struct request *req;
+ struct ibnbd_iu *iu;
+ struct ibnbd_dev *dev = q->queuedata;
+
+ while ((req = blk_fetch_request(q)) != NULL) {
+ spin_unlock_irq(q->queue_lock);
+
+ if (unlikely(!ibnbd_clt_dev_is_open(dev))) {
+ err = -EIO;
+ goto next;
+ }
+
+ iu = req->special;
+ if (WARN_ON(!iu)) {
+ err = -EIO;
+ goto next;
+ }
+
+ sg_init_table(iu->sglist, dev->max_segments);
+ err = ibnbd_client_xfer_request(dev, req, iu);
+next:
+ if (unlikely(err == -EAGAIN || err == -ENOMEM)) {
+ ibnbd_rq_unprep_fn(q, req);
+ spin_lock_irq(q->queue_lock);
+ blk_requeue_request(q, req);
+ ibnbd_dev_kick_queue(dev, IBNBD_DELAY_10ms);
+ break;
+ } else if (err) {
+ blk_end_request_all(req, err);
+ }
+
+ spin_lock_irq(q->queue_lock);
+ }
+}
+
+static int setup_mq_dev(struct ibnbd_dev *dev)
+{
+ dev->queue = blk_mq_init_queue(&dev->sess->tag_set);
+ if (IS_ERR(dev->queue)) {
+ ERR(dev, "Initializing multiqueue queue failed, errno: %ld\n",
+ PTR_ERR(dev->queue));
+ return PTR_ERR(dev->queue);
+ }
+ ibnbd_init_mq_hw_queues(dev);
+ return 0;
+}
+
+static int setup_rq_dev(struct ibnbd_dev *dev)
+{
+ dev->queue = blk_init_queue(ibnbd_clt_request, NULL);
+ if (IS_ERR_OR_NULL(dev->queue)) {
+ if (IS_ERR(dev->queue)) {
+ ERR(dev, "Initializing request queue failed, "
+ "errno: %ld\n", PTR_ERR(dev->queue));
+ return PTR_ERR(dev->queue);
+ }
+ ERR(dev, "Initializing request queue failed\n");
+ return -ENOMEM;
+ }
+
+ blk_queue_prep_rq(dev->queue, ibnbd_rq_prep_fn);
+ blk_queue_softirq_done(dev->queue, ibnbd_softirq_done_fn);
+ blk_queue_unprep_rq(dev->queue, ibnbd_rq_unprep_fn);
+
+ return 0;
+}
+
+static void setup_request_queue(struct ibnbd_dev *dev)
+{
+ blk_queue_logical_block_size(dev->queue, dev->logical_block_size);
+ blk_queue_physical_block_size(dev->queue, dev->physical_block_size);
+ blk_queue_max_hw_sectors(dev->queue, dev->max_hw_sectors);
+ blk_queue_max_write_same_sectors(dev->queue,
+ dev->max_write_same_sectors);
+
+ blk_queue_max_discard_sectors(dev->queue, dev->max_discard_sectors);
+ dev->queue->limits.discard_zeroes_data = dev->discard_zeroes_data;
+ dev->queue->limits.discard_granularity = dev->discard_granularity;
+ dev->queue->limits.discard_alignment = dev->discard_alignment;
+ if (dev->max_discard_sectors)
+ queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, dev->queue);
+ if (dev->secure_discard)
+ queue_flag_set_unlocked(QUEUE_FLAG_SECERASE, dev->queue);
+
+ queue_flag_set_unlocked(QUEUE_FLAG_SAME_COMP, dev->queue);
+ queue_flag_set_unlocked(QUEUE_FLAG_SAME_FORCE, dev->queue);
+ /* our hca only support 32 sg cnt, proto use one, so 31 left */
+ blk_queue_max_segments(dev->queue, dev->max_segments);
+ blk_queue_io_opt(dev->queue, dev->sess->max_io_size);
+ blk_queue_write_cache(dev->queue, true, true);
+ dev->queue->queuedata = dev;
+}
+
+static void ibnbd_clt_setup_gen_disk(struct ibnbd_dev *dev, int idx)
+{
+ dev->gd->major = ibnbd_client_major;
+ dev->gd->first_minor = index_to_minor(idx);
+ dev->gd->fops = &ibnbd_client_ops;
+ dev->gd->queue = dev->queue;
+ dev->gd->private_data = dev;
+ snprintf(dev->gd->disk_name, sizeof(dev->gd->disk_name), "ibnbd%d",
+ idx);
+ DEB("disk_name=%s, capacity=%zu, queue_mode=%s\n", dev->gd->disk_name,
+ dev->nsectors * (dev->logical_block_size / KERNEL_SECTOR_SIZE),
+ ibnbd_queue_mode_str(dev->queue_mode));
+
+ set_capacity(dev->gd, dev->nsectors * (dev->logical_block_size /
+ KERNEL_SECTOR_SIZE));
+
+ if (dev->access_mode == IBNBD_ACCESS_RO) {
+ dev->read_only = true;
+ set_disk_ro(dev->gd, true);
+ } else {
+ dev->read_only = false;
+ }
+
+ if (!dev->rotational)
+ queue_flag_set_unlocked(QUEUE_FLAG_NONROT, dev->queue);
+}
+
+static void ibnbd_clt_add_gen_disk(struct ibnbd_dev *dev)
+{
+ add_disk(dev->gd);
+}
+
+static int ibnbd_client_setup_device(struct ibnbd_session *sess,
+ struct ibnbd_dev *dev, int idx)
+{
+ int err;
+
+ dev->size = dev->nsectors * dev->logical_block_size;
+
+ switch (dev->queue_mode) {
+ case BLK_MQ:
+ err = setup_mq_dev(dev);
+ break;
+ case BLK_RQ:
+ err = setup_rq_dev(dev);
+ break;
+ default:
+ err = -EINVAL;
+ }
+
+ if (err)
+ return err;
+
+ setup_request_queue(dev);
+
+ dev->gd = alloc_disk_node(1 << IBNBD_PART_BITS, NUMA_NO_NODE);
+ if (!dev->gd) {
+ ERR(dev, "Failed to allocate disk node\n");
+ blk_cleanup_queue(dev->queue);
+ return -ENOMEM;
+ }
+
+ ibnbd_clt_setup_gen_disk(dev, idx);
+
+ return 0;
+}
+
+static struct ibnbd_dev *init_dev(struct ibnbd_session *sess,
+ enum ibnbd_access_mode access_mode,
+ enum ibnbd_queue_mode queue_mode,
+ const char *pathname)
+{
+ int ret;
+ struct ibnbd_dev *dev;
+ size_t nr;
+
+ dev = kzalloc_node(sizeof(*dev), GFP_KERNEL, NUMA_NO_NODE);
+ if (!dev) {
+ ERR_NP("Failed to initialize device '%s' from session %s,"
+ " allocating device structure failed\n", pathname,
+ sess->str_addr);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ nr = (queue_mode == BLK_MQ ? num_online_cpus() :
+ queue_mode == BLK_RQ ? 1 : 0);
+ if (nr) {
+ dev->hw_queues = kcalloc(nr, sizeof(*dev->hw_queues),
+ GFP_KERNEL);
+ if (unlikely(!dev->hw_queues)) {
+ ERR_NP("Failed to initialize device '%s' from session"
+ " %s, allocating hw_queues failed.", pathname,
+ sess->str_addr);
+ ret = -ENOMEM;
+ goto out_alloc;
+ }
+ /* for MQ mode we will init all hw queues after the
+ * request queue is created
+ */
+ if (queue_mode == BLK_RQ)
+ ibnbd_init_hw_queue(dev, dev->hw_queues, NULL);
+ }
+
+ idr_preload(GFP_KERNEL);
+ write_lock(&g_index_lock);
+ ret = idr_alloc(&g_index_idr, dev, 0, minor_to_index(1 << MINORBITS),
+ GFP_ATOMIC);
+ write_unlock(&g_index_lock);
+ idr_preload_end();
+ if (ret < 0) {
+ ERR_NP("Failed to initialize device '%s' from session %s,"
+ " allocating idr failed, errno: %d\n", pathname,
+ sess->str_addr, ret);
+ goto out_queues;
+ }
+
+ dev->clt_device_id = ret;
+ dev->close_compl = kmalloc(sizeof(*dev->close_compl),
+ GFP_KERNEL);
+ if (!dev->close_compl) {
+ ERR_NP("Failed to initialize device '%s' from session %s,"
+ " allocating close completion failed, errno: %d\n",
+ pathname, sess->str_addr, ret);
+ ret = -ENOMEM;
+ goto out_idr;
+ }
+ init_completion(dev->close_compl);
+ dev->sess = sess;
+ dev->access_mode = access_mode;
+ dev->queue_mode = queue_mode;
+
+ strlcpy(dev->pathname, pathname, sizeof(dev->pathname));
+
+ INIT_DELAYED_WORK(&dev->rq_delay_work, ibnbd_blk_delay_work);
+ mutex_init(&dev->lock);
+ atomic_set(&dev->refcount, 1);
+ dev->dev_state = DEV_STATE_INIT;
+
+ return dev;
+
+out_idr:
+ write_lock(&g_index_lock);
+ idr_remove(&g_index_idr, dev->clt_device_id);
+ write_unlock(&g_index_lock);
+out_queues:
+ kfree(dev->hw_queues);
+out_alloc:
+ kfree(dev);
+ return ERR_PTR(ret);
+}
+
+bool ibnbd_clt_dev_is_mapped(const char *pathname)
+{
+ struct ibnbd_dev *dev;
+
+ spin_lock(&dev_lock);
+ list_for_each_entry(dev, &devs_list, g_list)
+ if (!strncmp(dev->pathname, pathname, sizeof(dev->pathname))) {
+ spin_unlock(&dev_lock);
+ return true;
+ }
+ spin_unlock(&dev_lock);
+
+ return false;
+}
+
+static struct ibnbd_dev *__find_sess_dev(const struct ibnbd_session *sess,
+ const char *pathname)
+{
+ struct ibnbd_dev *dev;
+
+ list_for_each_entry(dev, &sess->devs_list, list)
+ if (!strncmp(dev->pathname, pathname, sizeof(dev->pathname)))
+ return dev;
+
+ return NULL;
+}
+
+struct ibnbd_dev *ibnbd_client_add_device(struct ibnbd_session *sess,
+ const char *pathname,
+ enum ibnbd_access_mode access_mode,
+ enum ibnbd_queue_mode queue_mode,
+ enum ibnbd_io_mode io_mode)
+{
+ int ret;
+ struct ibnbd_dev *dev;
+ struct completion *open_compl;
+
+ DEB("Add remote device: server=%s, path='%s', access_mode=%d,"
+ " queue_mode=%d\n", sess->str_addr, pathname, access_mode,
+ queue_mode);
+
+ mutex_lock(&sess->lock);
+
+ if (sess->state != SESS_STATE_READY) {
+ mutex_unlock(&sess->lock);
+ ERR_NP("map_device: failed to map device '%s' from session %s,"
+ " session is not connected\n", pathname, sess->str_addr);
+ return ERR_PTR(-ENOENT);
+ }
+
+ if (__find_sess_dev(sess, pathname)) {
+ mutex_unlock(&sess->lock);
+ ERR_NP("map_device: failed to map device '%s' from session %s,"
+ " device with same path is already mapped\n", pathname,
+ sess->str_addr);
+ return ERR_PTR(-EEXIST);
+ }
+
+ mutex_unlock(&sess->lock);
+ dev = init_dev(sess, access_mode, queue_mode, pathname);
+ if (IS_ERR(dev)) {
+ ERR_NP("map_device: failed to map device '%s' from session %s,"
+ " can't initialize device, errno: %ld\n", pathname,
+ sess->str_addr, PTR_ERR(dev));
+ return dev;
+ }
+
+ ibnbd_clt_get_sess(sess);
+
+ open_compl = kmalloc(sizeof(*open_compl), GFP_KERNEL);
+ if (!open_compl) {
+ ERR(dev, "map_device: failed, Can't allocate memory for"
+ " completion\n");
+ ret = -ENOMEM;
+ goto out;
+ }
+ init_completion(open_compl);
+ dev->open_compl = open_compl;
+ dev->io_mode = io_mode;
+
+ ret = open_remote_device(dev);
+ if (ret) {
+ ERR(dev, "map_device: failed, can't open remote device,"
+ " errno: %d\n", ret);
+ kfree(open_compl);
+ dev->open_compl = NULL;
+ ret = -EINVAL;
+ goto out;
+ }
+ wait_for_completion(dev->open_compl);
+ mutex_lock(&dev->lock);
+
+ kfree(open_compl);
+ dev->open_compl = NULL;
+
+ if (!ibnbd_clt_dev_is_open(dev)) {
+ mutex_unlock(&dev->lock);
+ ret = dev->open_errno;
+ ERR(dev, "map_device: failed errno: %d\n", ret);
+ goto out;
+ }
+
+ mutex_lock(&sess->lock);
+ list_add(&dev->list, &sess->devs_list);
+ mutex_unlock(&sess->lock);
+
+ spin_lock(&dev_lock);
+ list_add(&dev->g_list, &devs_list);
+ spin_unlock(&dev_lock);
+
+ DEB("Opened remote device: server=%s, path='%s'\n", sess->str_addr,
+ pathname);
+ ret = ibnbd_client_setup_device(sess, dev, dev->clt_device_id);
+ if (ret) {
+ ERR(dev, "map_device: Failed to configure device, errno: %d\n",
+ ret);
+ mutex_unlock(&dev->lock);
+ ret = -EINVAL;
+ goto out_close;
+ }
+
+ INFO(dev, "map_device: Device mapped as %s (nsectors: %zu,"
+ " logical_block_size: %d, physical_block_size: %d,"
+ " max_write_same_sectors: %d, max_discard_sectors: %d,"
+ " discard_zeroes_data: %d, discard_granularity: %d,"
+ " discard_alignment: %d, secure_discard: %d, max_segments: %d,"
+ " max_hw_sectors: %d, rotational: %d)\n", dev->gd->disk_name,
+ dev->nsectors, dev->logical_block_size, dev->physical_block_size,
+ dev->max_write_same_sectors, dev->max_discard_sectors,
+ dev->discard_zeroes_data, dev->discard_granularity,
+ dev->discard_alignment, dev->secure_discard,
+ dev->max_segments, dev->max_hw_sectors, dev->rotational);
+
+ mutex_unlock(&dev->lock);
+
+ ibnbd_clt_add_gen_disk(dev);
+
+ return dev;
+
+out_close:
+ if (!WARN_ON(ibnbd_close_device(dev, true)))
+ wait_for_completion(dev->close_compl);
+out:
+ ibnbd_clt_put_dev(dev);
+ return ERR_PTR(ret);
+}
+
+void ibnbd_destroy_gen_disk(struct ibnbd_dev *dev)
+{
+ del_gendisk(dev->gd);
+ /*
+ * Before marking queue as dying (blk_cleanup_queue() does that)
+ * we have to be sure that everything in-flight has gone.
+ * Blink with freeze/unfreeze.
+ */
+ blk_mq_freeze_queue(dev->queue);
+ blk_mq_unfreeze_queue(dev->queue);
+ blk_cleanup_queue(dev->queue);
+ put_disk(dev->gd);
+
+ ibnbd_clt_put_dev(dev);
+}
+
+static int __close_device(struct ibnbd_dev *dev, bool force)
+__must_hold(&dev->sess->lock)
+{
+ enum ibnbd_dev_state prev_state;
+ int refcount, ret = 0;
+
+ mutex_lock(&dev->lock);
+
+ if (dev->dev_state == DEV_STATE_UNMAPPED) {
+ INFO(dev, "Device is already being unmapped\n");
+ ret = -EALREADY;
+ goto out;
+ }
+
+ refcount = atomic_read(&dev->refcount);
+ if (!force && refcount > 1) {
+ ERR(dev, "Closing device failed, device is in use,"
+ " (%d device users)\n", refcount - 1);
+ ret = -EBUSY;
+ goto out;
+ }
+
+ prev_state = dev->dev_state;
+ dev->dev_state = DEV_STATE_UNMAPPED;
+
+ list_del(&dev->list);
+
+ spin_lock(&dev_lock);
+ list_del(&dev->g_list);
+ spin_unlock(&dev_lock);
+
+ ibnbd_clt_remove_dev_symlink(dev);
+ mutex_unlock(&dev->lock);
+
+ mutex_unlock(&dev->sess->lock);
+ if (prev_state == DEV_STATE_OPEN && dev->sess->sess) {
+ if (send_msg_close(dev->sess->sess, dev->device_id))
+ complete(dev->close_compl);
+ } else {
+ complete(dev->close_compl);
+ }
+
+ mutex_lock(&dev->sess->lock);
+ if (dev->gd)
+ INFO(dev, "Device is unmapped\n");
+ else
+ INFO(dev, "Device is unmapped\n");
+ return 0;
+out:
+ mutex_unlock(&dev->lock);
+ return ret;
+}
+
+int ibnbd_close_device(struct ibnbd_dev *dev, bool force)
+{
+ int ret;
+
+ mutex_lock(&dev->sess->lock);
+ ret = __close_device(dev, force);
+ mutex_unlock(&dev->sess->lock);
+
+ return ret;
+}
+
+static void ibnbd_destroy_sessions(void)
+{
+ struct ibnbd_session *sess, *sn;
+ struct ibnbd_dev *dev, *tn;
+ int ret;
+
+ list_for_each_entry_safe(sess, sn, &session_list, list) {
+ if (!ibnbd_clt_get_sess(sess))
+ continue;
+ mutex_lock(&sess->lock);
+ sess->state = SESS_STATE_DESTROYED;
+ list_for_each_entry_safe(dev, tn, &sess->devs_list, list) {
+ if (!kobject_get(&dev->kobj))
+ continue;
+ ret = __close_device(dev, true);
+ if (ret)
+ WRN(dev, "Closing device failed, errno: %d\n",
+ ret);
+ else
+ wait_for_completion(dev->close_compl);
+ ibnbd_clt_schedule_dev_destroy(dev);
+ kobject_put(&dev->kobj);
+ }
+ mutex_unlock(&sess->lock);
+ ibnbd_clt_put_sess(sess);
+ }
+}
+
+static int __init ibnbd_client_init(void)
+{
+ int err;
+
+ INFO_NP("Loading module ibnbd_client, version: "
+ __stringify(IBNBD_VER) " (softirq_enable: %d)\n",
+ softirq_enable);
+
+ ibnbd_client_major = register_blkdev(ibnbd_client_major, "ibnbd");
+ if (ibnbd_client_major <= 0) {
+ ERR_NP("Failed to load module,"
+ " block device registration failed\n");
+ err = -EBUSY;
+ goto out;
+ }
+
+ ops.owner = THIS_MODULE;
+ ops.recv = ibnbd_clt_recv;
+ ops.rdma_ev = ibnbd_clt_rdma_ev;
+ ops.sess_ev = ibnbd_clt_sess_ev;
+ err = ibtrs_clt_register(&ops);
+ if (err) {
+ ERR_NP("Failed to load module, IBTRS registration failed,"
+ " errno: %d\n", err);
+ goto out_unregister_blk;
+ }
+ err = ibnbd_clt_create_sysfs_files();
+ if (err) {
+ ERR_NP("Failed to load module,"
+ " creating sysfs device files failed, error: %d\n", err);
+ goto out_unregister;
+ }
+
+ return 0;
+
+out_unregister:
+ ibtrs_clt_unregister(&ops);
+out_unregister_blk:
+ unregister_blkdev(ibnbd_client_major, "ibnbd");
+out:
+ return err;
+}
+
+static void __exit ibnbd_client_exit(void)
+{
+ INFO_NP("Unloading module\n");
+ ibnbd_clt_destroy_default_group();
+ flush_scheduled_work();
+ ibnbd_destroy_sessions();
+ wait_event(sess_list_waitq, list_empty(&session_list));
+ ibnbd_clt_destroy_sysfs_files();
+ ibtrs_clt_unregister(&ops);
+ unregister_blkdev(ibnbd_client_major, "ibnbd");
+ idr_destroy(&g_index_idr);
+ INFO_NP("Module unloaded\n");
+}
+
+module_init(ibnbd_client_init);
+module_exit(ibnbd_client_exit);