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![Gioh Kim](/assets/img/avatar_default.png)
The IO performance test with fio after removing the likely and unlikely macros in all if-statement shows no performance drop. They do not help for the performance of rnbd. The fio test did random read on 32 rnbd devices and 64 processes. Test environment: - AMD Opteron(tm) Processor 6386 SE - 125G memory - kernel version: 5.4.86 - gcc version: gcc (Debian 8.3.0-6) 8.3.0 - Infiniband controller: InfiniBand: Mellanox Technologies MT26428 [ConnectX VPI PCIe 2.0 5GT/s - IB QDR / 10GigE] (rev b0) before read: IOPS=549k, BW=2146MiB/s read: IOPS=544k, BW=2125MiB/s read: IOPS=553k, BW=2158MiB/s read: IOPS=535k, BW=2089MiB/s read: IOPS=543k, BW=2122MiB/s read: IOPS=552k, BW=2154MiB/s average: IOPS=546k, BW=2132MiB/s after read: IOPS=556k, BW=2172MiB/s read: IOPS=561k, BW=2191MiB/s read: IOPS=552k, BW=2156MiB/s read: IOPS=551k, BW=2154MiB/s read: IOPS=562k, BW=2194MiB/s ----------- average: IOPS=556k, BW=2173MiB/s The IOPS and bandwidth got better slightly after removing likely/unlikely. (IOPS= +1.8% BW= +1.9%) But we cannot make sure that removing the likely/unlikely help the performance because it depends on various situations. We only make sure that removing the likely/unlikely does not drop the performance. Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com> Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com> Link: https://lore.kernel.org/r/20210428061359.206794-5-gi-oh.kim@ionos.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
1827 lines
46 KiB
C
1827 lines
46 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* RDMA Network Block Driver
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*
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* Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
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* Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
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* Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
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*/
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#undef pr_fmt
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#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
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#include <linux/module.h>
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#include <linux/blkdev.h>
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#include <linux/hdreg.h>
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#include <linux/scatterlist.h>
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#include <linux/idr.h>
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#include "rnbd-clt.h"
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MODULE_DESCRIPTION("RDMA Network Block Device Client");
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MODULE_LICENSE("GPL");
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static int rnbd_client_major;
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static DEFINE_IDA(index_ida);
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static DEFINE_MUTEX(ida_lock);
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static DEFINE_MUTEX(sess_lock);
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static LIST_HEAD(sess_list);
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/*
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* Maximum number of partitions an instance can have.
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* 6 bits = 64 minors = 63 partitions (one minor is used for the device itself)
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*/
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#define RNBD_PART_BITS 6
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static inline bool rnbd_clt_get_sess(struct rnbd_clt_session *sess)
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{
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return refcount_inc_not_zero(&sess->refcount);
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}
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static void free_sess(struct rnbd_clt_session *sess);
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static void rnbd_clt_put_sess(struct rnbd_clt_session *sess)
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{
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might_sleep();
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if (refcount_dec_and_test(&sess->refcount))
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free_sess(sess);
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}
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static void rnbd_clt_put_dev(struct rnbd_clt_dev *dev)
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{
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might_sleep();
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if (!refcount_dec_and_test(&dev->refcount))
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return;
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mutex_lock(&ida_lock);
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ida_simple_remove(&index_ida, dev->clt_device_id);
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mutex_unlock(&ida_lock);
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kfree(dev->hw_queues);
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kfree(dev->pathname);
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rnbd_clt_put_sess(dev->sess);
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mutex_destroy(&dev->lock);
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kfree(dev);
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}
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static inline bool rnbd_clt_get_dev(struct rnbd_clt_dev *dev)
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{
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return refcount_inc_not_zero(&dev->refcount);
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}
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static int rnbd_clt_set_dev_attr(struct rnbd_clt_dev *dev,
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const struct rnbd_msg_open_rsp *rsp)
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{
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struct rnbd_clt_session *sess = dev->sess;
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if (!rsp->logical_block_size)
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return -EINVAL;
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dev->device_id = le32_to_cpu(rsp->device_id);
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dev->nsectors = le64_to_cpu(rsp->nsectors);
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dev->logical_block_size = le16_to_cpu(rsp->logical_block_size);
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dev->physical_block_size = le16_to_cpu(rsp->physical_block_size);
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dev->max_write_same_sectors = le32_to_cpu(rsp->max_write_same_sectors);
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dev->max_discard_sectors = le32_to_cpu(rsp->max_discard_sectors);
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dev->discard_granularity = le32_to_cpu(rsp->discard_granularity);
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dev->discard_alignment = le32_to_cpu(rsp->discard_alignment);
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dev->secure_discard = le16_to_cpu(rsp->secure_discard);
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dev->rotational = rsp->rotational;
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dev->wc = !!(rsp->cache_policy & RNBD_WRITEBACK);
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dev->fua = !!(rsp->cache_policy & RNBD_FUA);
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dev->max_hw_sectors = sess->max_io_size / SECTOR_SIZE;
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dev->max_segments = BMAX_SEGMENTS;
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return 0;
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}
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static int rnbd_clt_change_capacity(struct rnbd_clt_dev *dev,
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size_t new_nsectors)
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{
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rnbd_clt_info(dev, "Device size changed from %zu to %zu sectors\n",
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dev->nsectors, new_nsectors);
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dev->nsectors = new_nsectors;
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set_capacity_and_notify(dev->gd, dev->nsectors);
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return 0;
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}
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static int process_msg_open_rsp(struct rnbd_clt_dev *dev,
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struct rnbd_msg_open_rsp *rsp)
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{
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struct kobject *gd_kobj;
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int err = 0;
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mutex_lock(&dev->lock);
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if (dev->dev_state == DEV_STATE_UNMAPPED) {
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rnbd_clt_info(dev,
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"Ignoring Open-Response message from server for unmapped device\n");
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err = -ENOENT;
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goto out;
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}
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if (dev->dev_state == DEV_STATE_MAPPED_DISCONNECTED) {
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u64 nsectors = le64_to_cpu(rsp->nsectors);
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/*
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* If the device was remapped and the size changed in the
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* meantime we need to revalidate it
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*/
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if (dev->nsectors != nsectors)
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rnbd_clt_change_capacity(dev, nsectors);
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gd_kobj = &disk_to_dev(dev->gd)->kobj;
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kobject_uevent(gd_kobj, KOBJ_ONLINE);
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rnbd_clt_info(dev, "Device online, device remapped successfully\n");
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}
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err = rnbd_clt_set_dev_attr(dev, rsp);
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if (err)
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goto out;
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dev->dev_state = DEV_STATE_MAPPED;
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out:
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mutex_unlock(&dev->lock);
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return err;
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}
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int rnbd_clt_resize_disk(struct rnbd_clt_dev *dev, size_t newsize)
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{
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int ret = 0;
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mutex_lock(&dev->lock);
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if (dev->dev_state != DEV_STATE_MAPPED) {
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pr_err("Failed to set new size of the device, device is not opened\n");
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ret = -ENOENT;
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goto out;
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}
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ret = rnbd_clt_change_capacity(dev, newsize);
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out:
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mutex_unlock(&dev->lock);
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return ret;
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}
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static inline void rnbd_clt_dev_requeue(struct rnbd_queue *q)
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{
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if (WARN_ON(!q->hctx))
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return;
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/* We can come here from interrupt, thus async=true */
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blk_mq_run_hw_queue(q->hctx, true);
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}
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enum {
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RNBD_DELAY_IFBUSY = -1,
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};
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/**
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* rnbd_get_cpu_qlist() - finds a list with HW queues to be rerun
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* @sess: Session to find a queue for
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* @cpu: Cpu to start the search from
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*
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* Description:
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* Each CPU has a list of HW queues, which needs to be rerun. If a list
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* is not empty - it is marked with a bit. This function finds first
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* set bit in a bitmap and returns corresponding CPU list.
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*/
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static struct rnbd_cpu_qlist *
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rnbd_get_cpu_qlist(struct rnbd_clt_session *sess, int cpu)
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{
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int bit;
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/* Search from cpu to nr_cpu_ids */
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bit = find_next_bit(sess->cpu_queues_bm, nr_cpu_ids, cpu);
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if (bit < nr_cpu_ids) {
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return per_cpu_ptr(sess->cpu_queues, bit);
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} else if (cpu != 0) {
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/* Search from 0 to cpu */
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bit = find_next_bit(sess->cpu_queues_bm, cpu, 0);
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if (bit < cpu)
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return per_cpu_ptr(sess->cpu_queues, bit);
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}
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return NULL;
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}
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static inline int nxt_cpu(int cpu)
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{
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return (cpu + 1) % nr_cpu_ids;
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}
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/**
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* rnbd_rerun_if_needed() - rerun next queue marked as stopped
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* @sess: Session to rerun a queue on
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*
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* Description:
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* Each CPU has it's own list of HW queues, which should be rerun.
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* Function finds such list with HW queues, takes a list lock, picks up
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* the first HW queue out of the list and requeues it.
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*
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* Return:
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* True if the queue was requeued, false otherwise.
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*
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* Context:
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* Does not matter.
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*/
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static bool rnbd_rerun_if_needed(struct rnbd_clt_session *sess)
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{
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struct rnbd_queue *q = NULL;
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struct rnbd_cpu_qlist *cpu_q;
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unsigned long flags;
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int *cpup;
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/*
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* To keep fairness and not to let other queues starve we always
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* try to wake up someone else in round-robin manner. That of course
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* increases latency but queues always have a chance to be executed.
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*/
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cpup = get_cpu_ptr(sess->cpu_rr);
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for (cpu_q = rnbd_get_cpu_qlist(sess, nxt_cpu(*cpup)); cpu_q;
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cpu_q = rnbd_get_cpu_qlist(sess, nxt_cpu(cpu_q->cpu))) {
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if (!spin_trylock_irqsave(&cpu_q->requeue_lock, flags))
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continue;
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if (!test_bit(cpu_q->cpu, sess->cpu_queues_bm))
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goto unlock;
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q = list_first_entry_or_null(&cpu_q->requeue_list,
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typeof(*q), requeue_list);
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if (WARN_ON(!q))
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goto clear_bit;
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list_del_init(&q->requeue_list);
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clear_bit_unlock(0, &q->in_list);
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if (list_empty(&cpu_q->requeue_list)) {
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/* Clear bit if nothing is left */
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clear_bit:
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clear_bit(cpu_q->cpu, sess->cpu_queues_bm);
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}
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unlock:
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spin_unlock_irqrestore(&cpu_q->requeue_lock, flags);
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if (q)
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break;
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}
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/**
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* Saves the CPU that is going to be requeued on the per-cpu var. Just
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* incrementing it doesn't work because rnbd_get_cpu_qlist() will
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* always return the first CPU with something on the queue list when the
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* value stored on the var is greater than the last CPU with something
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* on the list.
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*/
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if (cpu_q)
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*cpup = cpu_q->cpu;
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put_cpu_var(sess->cpu_rr);
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if (q)
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rnbd_clt_dev_requeue(q);
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return q;
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}
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/**
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* rnbd_rerun_all_if_idle() - rerun all queues left in the list if
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* session is idling (there are no requests
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* in-flight).
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* @sess: Session to rerun the queues on
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*
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* Description:
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* This function tries to rerun all stopped queues if there are no
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* requests in-flight anymore. This function tries to solve an obvious
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* problem, when number of tags < than number of queues (hctx), which
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* are stopped and put to sleep. If last permit, which has been just put,
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* does not wake up all left queues (hctxs), IO requests hang forever.
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*
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* That can happen when all number of permits, say N, have been exhausted
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* from one CPU, and we have many block devices per session, say M.
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* Each block device has it's own queue (hctx) for each CPU, so eventually
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* we can put that number of queues (hctxs) to sleep: M x nr_cpu_ids.
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* If number of permits N < M x nr_cpu_ids finally we will get an IO hang.
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*
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* To avoid this hang last caller of rnbd_put_permit() (last caller is the
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* one who observes sess->busy == 0) must wake up all remaining queues.
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*
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* Context:
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* Does not matter.
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*/
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static void rnbd_rerun_all_if_idle(struct rnbd_clt_session *sess)
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{
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bool requeued;
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do {
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requeued = rnbd_rerun_if_needed(sess);
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} while (atomic_read(&sess->busy) == 0 && requeued);
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}
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static struct rtrs_permit *rnbd_get_permit(struct rnbd_clt_session *sess,
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enum rtrs_clt_con_type con_type,
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enum wait_type wait)
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{
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struct rtrs_permit *permit;
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permit = rtrs_clt_get_permit(sess->rtrs, con_type, wait);
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if (permit)
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/* We have a subtle rare case here, when all permits can be
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* consumed before busy counter increased. This is safe,
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* because loser will get NULL as a permit, observe 0 busy
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* counter and immediately restart the queue himself.
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*/
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atomic_inc(&sess->busy);
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return permit;
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}
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static void rnbd_put_permit(struct rnbd_clt_session *sess,
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struct rtrs_permit *permit)
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{
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rtrs_clt_put_permit(sess->rtrs, permit);
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atomic_dec(&sess->busy);
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/* Paired with rnbd_clt_dev_add_to_requeue(). Decrement first
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* and then check queue bits.
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*/
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smp_mb__after_atomic();
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rnbd_rerun_all_if_idle(sess);
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}
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static struct rnbd_iu *rnbd_get_iu(struct rnbd_clt_session *sess,
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enum rtrs_clt_con_type con_type,
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enum wait_type wait)
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{
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struct rnbd_iu *iu;
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struct rtrs_permit *permit;
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iu = kzalloc(sizeof(*iu), GFP_KERNEL);
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if (!iu)
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return NULL;
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permit = rnbd_get_permit(sess, con_type, wait);
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if (!permit) {
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kfree(iu);
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return NULL;
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}
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iu->permit = permit;
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/*
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* 1st reference is dropped after finishing sending a "user" message,
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* 2nd reference is dropped after confirmation with the response is
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* returned.
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* 1st and 2nd can happen in any order, so the rnbd_iu should be
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* released (rtrs_permit returned to rtrs) only after both
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* are finished.
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*/
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atomic_set(&iu->refcount, 2);
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init_waitqueue_head(&iu->comp.wait);
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iu->comp.errno = INT_MAX;
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if (sg_alloc_table(&iu->sgt, 1, GFP_KERNEL)) {
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rnbd_put_permit(sess, permit);
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kfree(iu);
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return NULL;
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}
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return iu;
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}
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static void rnbd_put_iu(struct rnbd_clt_session *sess, struct rnbd_iu *iu)
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{
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if (atomic_dec_and_test(&iu->refcount)) {
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sg_free_table(&iu->sgt);
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rnbd_put_permit(sess, iu->permit);
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kfree(iu);
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}
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}
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static void rnbd_softirq_done_fn(struct request *rq)
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{
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struct rnbd_clt_dev *dev = rq->rq_disk->private_data;
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struct rnbd_clt_session *sess = dev->sess;
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struct rnbd_iu *iu;
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iu = blk_mq_rq_to_pdu(rq);
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sg_free_table_chained(&iu->sgt, RNBD_INLINE_SG_CNT);
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rnbd_put_permit(sess, iu->permit);
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blk_mq_end_request(rq, errno_to_blk_status(iu->errno));
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}
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static void msg_io_conf(void *priv, int errno)
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{
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struct rnbd_iu *iu = priv;
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struct rnbd_clt_dev *dev = iu->dev;
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struct request *rq = iu->rq;
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int rw = rq_data_dir(rq);
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iu->errno = errno;
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blk_mq_complete_request(rq);
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if (errno)
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rnbd_clt_info_rl(dev, "%s I/O failed with err: %d\n",
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rw == READ ? "read" : "write", errno);
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}
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static void wake_up_iu_comp(struct rnbd_iu *iu, int errno)
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{
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iu->comp.errno = errno;
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wake_up(&iu->comp.wait);
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}
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static void msg_conf(void *priv, int errno)
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{
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struct rnbd_iu *iu = priv;
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iu->errno = errno;
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schedule_work(&iu->work);
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}
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static int send_usr_msg(struct rtrs_clt *rtrs, int dir,
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struct rnbd_iu *iu, struct kvec *vec,
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size_t len, struct scatterlist *sg, unsigned int sg_len,
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void (*conf)(struct work_struct *work),
|
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int *errno, int wait)
|
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{
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int err;
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struct rtrs_clt_req_ops req_ops;
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INIT_WORK(&iu->work, conf);
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req_ops = (struct rtrs_clt_req_ops) {
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.priv = iu,
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.conf_fn = msg_conf,
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};
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err = rtrs_clt_request(dir, &req_ops, rtrs, iu->permit,
|
|
vec, 1, len, sg, sg_len);
|
|
if (!err && wait) {
|
|
wait_event(iu->comp.wait, iu->comp.errno != INT_MAX);
|
|
*errno = iu->comp.errno;
|
|
} else {
|
|
*errno = 0;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static void msg_close_conf(struct work_struct *work)
|
|
{
|
|
struct rnbd_iu *iu = container_of(work, struct rnbd_iu, work);
|
|
struct rnbd_clt_dev *dev = iu->dev;
|
|
|
|
wake_up_iu_comp(iu, iu->errno);
|
|
rnbd_put_iu(dev->sess, iu);
|
|
rnbd_clt_put_dev(dev);
|
|
}
|
|
|
|
static int send_msg_close(struct rnbd_clt_dev *dev, u32 device_id,
|
|
enum wait_type wait)
|
|
{
|
|
struct rnbd_clt_session *sess = dev->sess;
|
|
struct rnbd_msg_close msg;
|
|
struct rnbd_iu *iu;
|
|
struct kvec vec = {
|
|
.iov_base = &msg,
|
|
.iov_len = sizeof(msg)
|
|
};
|
|
int err, errno;
|
|
|
|
iu = rnbd_get_iu(sess, RTRS_ADMIN_CON, RTRS_PERMIT_WAIT);
|
|
if (!iu)
|
|
return -ENOMEM;
|
|
|
|
iu->buf = NULL;
|
|
iu->dev = dev;
|
|
|
|
msg.hdr.type = cpu_to_le16(RNBD_MSG_CLOSE);
|
|
msg.device_id = cpu_to_le32(device_id);
|
|
|
|
WARN_ON(!rnbd_clt_get_dev(dev));
|
|
err = send_usr_msg(sess->rtrs, WRITE, iu, &vec, 0, NULL, 0,
|
|
msg_close_conf, &errno, wait);
|
|
if (err) {
|
|
rnbd_clt_put_dev(dev);
|
|
rnbd_put_iu(sess, iu);
|
|
} else {
|
|
err = errno;
|
|
}
|
|
|
|
rnbd_put_iu(sess, iu);
|
|
return err;
|
|
}
|
|
|
|
static void msg_open_conf(struct work_struct *work)
|
|
{
|
|
struct rnbd_iu *iu = container_of(work, struct rnbd_iu, work);
|
|
struct rnbd_msg_open_rsp *rsp = iu->buf;
|
|
struct rnbd_clt_dev *dev = iu->dev;
|
|
int errno = iu->errno;
|
|
|
|
if (errno) {
|
|
rnbd_clt_err(dev,
|
|
"Opening failed, server responded: %d\n",
|
|
errno);
|
|
} else {
|
|
errno = process_msg_open_rsp(dev, rsp);
|
|
if (errno) {
|
|
u32 device_id = le32_to_cpu(rsp->device_id);
|
|
/*
|
|
* If server thinks its fine, but we fail to process
|
|
* then be nice and send a close to server.
|
|
*/
|
|
send_msg_close(dev, device_id, RTRS_PERMIT_NOWAIT);
|
|
}
|
|
}
|
|
kfree(rsp);
|
|
wake_up_iu_comp(iu, errno);
|
|
rnbd_put_iu(dev->sess, iu);
|
|
rnbd_clt_put_dev(dev);
|
|
}
|
|
|
|
static void msg_sess_info_conf(struct work_struct *work)
|
|
{
|
|
struct rnbd_iu *iu = container_of(work, struct rnbd_iu, work);
|
|
struct rnbd_msg_sess_info_rsp *rsp = iu->buf;
|
|
struct rnbd_clt_session *sess = iu->sess;
|
|
|
|
if (!iu->errno)
|
|
sess->ver = min_t(u8, rsp->ver, RNBD_PROTO_VER_MAJOR);
|
|
|
|
kfree(rsp);
|
|
wake_up_iu_comp(iu, iu->errno);
|
|
rnbd_put_iu(sess, iu);
|
|
rnbd_clt_put_sess(sess);
|
|
}
|
|
|
|
static int send_msg_open(struct rnbd_clt_dev *dev, enum wait_type wait)
|
|
{
|
|
struct rnbd_clt_session *sess = dev->sess;
|
|
struct rnbd_msg_open_rsp *rsp;
|
|
struct rnbd_msg_open msg;
|
|
struct rnbd_iu *iu;
|
|
struct kvec vec = {
|
|
.iov_base = &msg,
|
|
.iov_len = sizeof(msg)
|
|
};
|
|
int err, errno;
|
|
|
|
rsp = kzalloc(sizeof(*rsp), GFP_KERNEL);
|
|
if (!rsp)
|
|
return -ENOMEM;
|
|
|
|
iu = rnbd_get_iu(sess, RTRS_ADMIN_CON, RTRS_PERMIT_WAIT);
|
|
if (!iu) {
|
|
kfree(rsp);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
iu->buf = rsp;
|
|
iu->dev = dev;
|
|
|
|
sg_init_one(iu->sgt.sgl, rsp, sizeof(*rsp));
|
|
|
|
msg.hdr.type = cpu_to_le16(RNBD_MSG_OPEN);
|
|
msg.access_mode = dev->access_mode;
|
|
strscpy(msg.dev_name, dev->pathname, sizeof(msg.dev_name));
|
|
|
|
WARN_ON(!rnbd_clt_get_dev(dev));
|
|
err = send_usr_msg(sess->rtrs, READ, iu,
|
|
&vec, sizeof(*rsp), iu->sgt.sgl, 1,
|
|
msg_open_conf, &errno, wait);
|
|
if (err) {
|
|
rnbd_clt_put_dev(dev);
|
|
rnbd_put_iu(sess, iu);
|
|
kfree(rsp);
|
|
} else {
|
|
err = errno;
|
|
}
|
|
|
|
rnbd_put_iu(sess, iu);
|
|
return err;
|
|
}
|
|
|
|
static int send_msg_sess_info(struct rnbd_clt_session *sess, enum wait_type wait)
|
|
{
|
|
struct rnbd_msg_sess_info_rsp *rsp;
|
|
struct rnbd_msg_sess_info msg;
|
|
struct rnbd_iu *iu;
|
|
struct kvec vec = {
|
|
.iov_base = &msg,
|
|
.iov_len = sizeof(msg)
|
|
};
|
|
int err, errno;
|
|
|
|
rsp = kzalloc(sizeof(*rsp), GFP_KERNEL);
|
|
if (!rsp)
|
|
return -ENOMEM;
|
|
|
|
iu = rnbd_get_iu(sess, RTRS_ADMIN_CON, RTRS_PERMIT_WAIT);
|
|
if (!iu) {
|
|
kfree(rsp);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
iu->buf = rsp;
|
|
iu->sess = sess;
|
|
sg_init_one(iu->sgt.sgl, rsp, sizeof(*rsp));
|
|
|
|
msg.hdr.type = cpu_to_le16(RNBD_MSG_SESS_INFO);
|
|
msg.ver = RNBD_PROTO_VER_MAJOR;
|
|
|
|
if (!rnbd_clt_get_sess(sess)) {
|
|
/*
|
|
* That can happen only in one case, when RTRS has restablished
|
|
* the connection and link_ev() is called, but session is almost
|
|
* dead, last reference on session is put and caller is waiting
|
|
* for RTRS to close everything.
|
|
*/
|
|
err = -ENODEV;
|
|
goto put_iu;
|
|
}
|
|
err = send_usr_msg(sess->rtrs, READ, iu,
|
|
&vec, sizeof(*rsp), iu->sgt.sgl, 1,
|
|
msg_sess_info_conf, &errno, wait);
|
|
if (err) {
|
|
rnbd_clt_put_sess(sess);
|
|
put_iu:
|
|
rnbd_put_iu(sess, iu);
|
|
kfree(rsp);
|
|
} else {
|
|
err = errno;
|
|
}
|
|
rnbd_put_iu(sess, iu);
|
|
return err;
|
|
}
|
|
|
|
static void set_dev_states_to_disconnected(struct rnbd_clt_session *sess)
|
|
{
|
|
struct rnbd_clt_dev *dev;
|
|
struct kobject *gd_kobj;
|
|
|
|
mutex_lock(&sess->lock);
|
|
list_for_each_entry(dev, &sess->devs_list, list) {
|
|
rnbd_clt_err(dev, "Device disconnected.\n");
|
|
|
|
mutex_lock(&dev->lock);
|
|
if (dev->dev_state == DEV_STATE_MAPPED) {
|
|
dev->dev_state = DEV_STATE_MAPPED_DISCONNECTED;
|
|
gd_kobj = &disk_to_dev(dev->gd)->kobj;
|
|
kobject_uevent(gd_kobj, KOBJ_OFFLINE);
|
|
}
|
|
mutex_unlock(&dev->lock);
|
|
}
|
|
mutex_unlock(&sess->lock);
|
|
}
|
|
|
|
static void remap_devs(struct rnbd_clt_session *sess)
|
|
{
|
|
struct rnbd_clt_dev *dev;
|
|
struct rtrs_attrs attrs;
|
|
int err;
|
|
|
|
/*
|
|
* Careful here: we are called from RTRS link event directly,
|
|
* thus we can't send any RTRS request and wait for response
|
|
* or RTRS will not be able to complete request with failure
|
|
* if something goes wrong (failing of outstanding requests
|
|
* happens exactly from the context where we are blocking now).
|
|
*
|
|
* So to avoid deadlocks each usr message sent from here must
|
|
* be asynchronous.
|
|
*/
|
|
|
|
err = send_msg_sess_info(sess, RTRS_PERMIT_NOWAIT);
|
|
if (err) {
|
|
pr_err("send_msg_sess_info(\"%s\"): %d\n", sess->sessname, err);
|
|
return;
|
|
}
|
|
|
|
err = rtrs_clt_query(sess->rtrs, &attrs);
|
|
if (err) {
|
|
pr_err("rtrs_clt_query(\"%s\"): %d\n", sess->sessname, err);
|
|
return;
|
|
}
|
|
mutex_lock(&sess->lock);
|
|
sess->max_io_size = attrs.max_io_size;
|
|
|
|
list_for_each_entry(dev, &sess->devs_list, list) {
|
|
bool skip;
|
|
|
|
mutex_lock(&dev->lock);
|
|
skip = (dev->dev_state == DEV_STATE_INIT);
|
|
mutex_unlock(&dev->lock);
|
|
if (skip)
|
|
/*
|
|
* When device is establishing connection for the first
|
|
* time - do not remap, it will be closed soon.
|
|
*/
|
|
continue;
|
|
|
|
rnbd_clt_info(dev, "session reconnected, remapping device\n");
|
|
err = send_msg_open(dev, RTRS_PERMIT_NOWAIT);
|
|
if (err) {
|
|
rnbd_clt_err(dev, "send_msg_open(): %d\n", err);
|
|
break;
|
|
}
|
|
}
|
|
mutex_unlock(&sess->lock);
|
|
}
|
|
|
|
static void rnbd_clt_link_ev(void *priv, enum rtrs_clt_link_ev ev)
|
|
{
|
|
struct rnbd_clt_session *sess = priv;
|
|
|
|
switch (ev) {
|
|
case RTRS_CLT_LINK_EV_DISCONNECTED:
|
|
set_dev_states_to_disconnected(sess);
|
|
break;
|
|
case RTRS_CLT_LINK_EV_RECONNECTED:
|
|
remap_devs(sess);
|
|
break;
|
|
default:
|
|
pr_err("Unknown session event received (%d), session: %s\n",
|
|
ev, sess->sessname);
|
|
}
|
|
}
|
|
|
|
static void rnbd_init_cpu_qlists(struct rnbd_cpu_qlist __percpu *cpu_queues)
|
|
{
|
|
unsigned int cpu;
|
|
struct rnbd_cpu_qlist *cpu_q;
|
|
|
|
for_each_possible_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 void destroy_mq_tags(struct rnbd_clt_session *sess)
|
|
{
|
|
if (sess->tag_set.tags)
|
|
blk_mq_free_tag_set(&sess->tag_set);
|
|
}
|
|
|
|
static inline void wake_up_rtrs_waiters(struct rnbd_clt_session *sess)
|
|
{
|
|
sess->rtrs_ready = true;
|
|
wake_up_all(&sess->rtrs_waitq);
|
|
}
|
|
|
|
static void close_rtrs(struct rnbd_clt_session *sess)
|
|
{
|
|
might_sleep();
|
|
|
|
if (!IS_ERR_OR_NULL(sess->rtrs)) {
|
|
rtrs_clt_close(sess->rtrs);
|
|
sess->rtrs = NULL;
|
|
wake_up_rtrs_waiters(sess);
|
|
}
|
|
}
|
|
|
|
static void free_sess(struct rnbd_clt_session *sess)
|
|
{
|
|
WARN_ON(!list_empty(&sess->devs_list));
|
|
|
|
might_sleep();
|
|
|
|
close_rtrs(sess);
|
|
destroy_mq_tags(sess);
|
|
if (!list_empty(&sess->list)) {
|
|
mutex_lock(&sess_lock);
|
|
list_del(&sess->list);
|
|
mutex_unlock(&sess_lock);
|
|
}
|
|
free_percpu(sess->cpu_queues);
|
|
free_percpu(sess->cpu_rr);
|
|
mutex_destroy(&sess->lock);
|
|
kfree(sess);
|
|
}
|
|
|
|
static struct rnbd_clt_session *alloc_sess(const char *sessname)
|
|
{
|
|
struct rnbd_clt_session *sess;
|
|
int err, cpu;
|
|
|
|
sess = kzalloc_node(sizeof(*sess), GFP_KERNEL, NUMA_NO_NODE);
|
|
if (!sess)
|
|
return ERR_PTR(-ENOMEM);
|
|
strscpy(sess->sessname, sessname, sizeof(sess->sessname));
|
|
atomic_set(&sess->busy, 0);
|
|
mutex_init(&sess->lock);
|
|
INIT_LIST_HEAD(&sess->devs_list);
|
|
INIT_LIST_HEAD(&sess->list);
|
|
bitmap_zero(sess->cpu_queues_bm, num_possible_cpus());
|
|
init_waitqueue_head(&sess->rtrs_waitq);
|
|
refcount_set(&sess->refcount, 1);
|
|
|
|
sess->cpu_queues = alloc_percpu(struct rnbd_cpu_qlist);
|
|
if (!sess->cpu_queues) {
|
|
err = -ENOMEM;
|
|
goto err;
|
|
}
|
|
rnbd_init_cpu_qlists(sess->cpu_queues);
|
|
|
|
/*
|
|
* That is simple percpu variable which stores cpu indices, 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 (!sess->cpu_rr) {
|
|
err = -ENOMEM;
|
|
goto err;
|
|
}
|
|
for_each_possible_cpu(cpu)
|
|
* per_cpu_ptr(sess->cpu_rr, cpu) = cpu;
|
|
|
|
return sess;
|
|
|
|
err:
|
|
free_sess(sess);
|
|
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static int wait_for_rtrs_connection(struct rnbd_clt_session *sess)
|
|
{
|
|
wait_event(sess->rtrs_waitq, sess->rtrs_ready);
|
|
if (IS_ERR_OR_NULL(sess->rtrs))
|
|
return -ECONNRESET;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void wait_for_rtrs_disconnection(struct rnbd_clt_session *sess)
|
|
__releases(&sess_lock)
|
|
__acquires(&sess_lock)
|
|
{
|
|
DEFINE_WAIT(wait);
|
|
|
|
prepare_to_wait(&sess->rtrs_waitq, &wait, TASK_UNINTERRUPTIBLE);
|
|
if (IS_ERR_OR_NULL(sess->rtrs)) {
|
|
finish_wait(&sess->rtrs_waitq, &wait);
|
|
return;
|
|
}
|
|
mutex_unlock(&sess_lock);
|
|
/* loop in caller, see __find_and_get_sess().
|
|
* You can't leave mutex locked and call schedule(), you will catch a
|
|
* deadlock with a caller of free_sess(), which has just put the last
|
|
* reference and is about to take the sess_lock in order to delete
|
|
* the session from the list.
|
|
*/
|
|
schedule();
|
|
mutex_lock(&sess_lock);
|
|
}
|
|
|
|
static struct rnbd_clt_session *__find_and_get_sess(const char *sessname)
|
|
__releases(&sess_lock)
|
|
__acquires(&sess_lock)
|
|
{
|
|
struct rnbd_clt_session *sess, *sn;
|
|
int err;
|
|
|
|
again:
|
|
list_for_each_entry_safe(sess, sn, &sess_list, list) {
|
|
if (strcmp(sessname, sess->sessname))
|
|
continue;
|
|
|
|
if (sess->rtrs_ready && IS_ERR_OR_NULL(sess->rtrs))
|
|
/*
|
|
* No RTRS connection, session is dying.
|
|
*/
|
|
continue;
|
|
|
|
if (rnbd_clt_get_sess(sess)) {
|
|
/*
|
|
* Alive session is found, wait for RTRS connection.
|
|
*/
|
|
mutex_unlock(&sess_lock);
|
|
err = wait_for_rtrs_connection(sess);
|
|
if (err)
|
|
rnbd_clt_put_sess(sess);
|
|
mutex_lock(&sess_lock);
|
|
|
|
if (err)
|
|
/* Session is dying, repeat the loop */
|
|
goto again;
|
|
|
|
return sess;
|
|
}
|
|
/*
|
|
* Ref is 0, session is dying, wait for RTRS disconnect
|
|
* in order to avoid session names clashes.
|
|
*/
|
|
wait_for_rtrs_disconnection(sess);
|
|
/*
|
|
* RTRS is disconnected and soon session will be freed,
|
|
* so repeat a loop.
|
|
*/
|
|
goto again;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* caller is responsible for initializing 'first' to false */
|
|
static struct
|
|
rnbd_clt_session *find_or_create_sess(const char *sessname, bool *first)
|
|
{
|
|
struct rnbd_clt_session *sess = NULL;
|
|
|
|
mutex_lock(&sess_lock);
|
|
sess = __find_and_get_sess(sessname);
|
|
if (!sess) {
|
|
sess = alloc_sess(sessname);
|
|
if (IS_ERR(sess)) {
|
|
mutex_unlock(&sess_lock);
|
|
return sess;
|
|
}
|
|
list_add(&sess->list, &sess_list);
|
|
*first = true;
|
|
}
|
|
mutex_unlock(&sess_lock);
|
|
|
|
return sess;
|
|
}
|
|
|
|
static int rnbd_client_open(struct block_device *block_device, fmode_t mode)
|
|
{
|
|
struct rnbd_clt_dev *dev = block_device->bd_disk->private_data;
|
|
|
|
if (dev->read_only && (mode & FMODE_WRITE))
|
|
return -EPERM;
|
|
|
|
if (dev->dev_state == DEV_STATE_UNMAPPED ||
|
|
!rnbd_clt_get_dev(dev))
|
|
return -EIO;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void rnbd_client_release(struct gendisk *gen, fmode_t mode)
|
|
{
|
|
struct rnbd_clt_dev *dev = gen->private_data;
|
|
|
|
rnbd_clt_put_dev(dev);
|
|
}
|
|
|
|
static int rnbd_client_getgeo(struct block_device *block_device,
|
|
struct hd_geometry *geo)
|
|
{
|
|
u64 size;
|
|
struct rnbd_clt_dev *dev;
|
|
|
|
dev = block_device->bd_disk->private_data;
|
|
size = dev->size * (dev->logical_block_size / SECTOR_SIZE);
|
|
geo->cylinders = size >> 6; /* size/64 */
|
|
geo->heads = 4;
|
|
geo->sectors = 16;
|
|
geo->start = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct block_device_operations rnbd_client_ops = {
|
|
.owner = THIS_MODULE,
|
|
.open = rnbd_client_open,
|
|
.release = rnbd_client_release,
|
|
.getgeo = rnbd_client_getgeo
|
|
};
|
|
|
|
/* The amount of data that belongs to an I/O and the amount of data that
|
|
* should be read or written to the disk (bi_size) can differ.
|
|
*
|
|
* E.g. When WRITE_SAME is used, only a small amount of data is
|
|
* transferred that is then written repeatedly over a lot of sectors.
|
|
*
|
|
* Get the size of data to be transferred via RTRS by summing up the size
|
|
* of the scather-gather list entries.
|
|
*/
|
|
static size_t rnbd_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 int rnbd_client_xfer_request(struct rnbd_clt_dev *dev,
|
|
struct request *rq,
|
|
struct rnbd_iu *iu)
|
|
{
|
|
struct rtrs_clt *rtrs = dev->sess->rtrs;
|
|
struct rtrs_permit *permit = iu->permit;
|
|
struct rnbd_msg_io msg;
|
|
struct rtrs_clt_req_ops req_ops;
|
|
unsigned int sg_cnt = 0;
|
|
struct kvec vec;
|
|
size_t size;
|
|
int err;
|
|
|
|
iu->rq = rq;
|
|
iu->dev = dev;
|
|
msg.sector = cpu_to_le64(blk_rq_pos(rq));
|
|
msg.bi_size = cpu_to_le32(blk_rq_bytes(rq));
|
|
msg.rw = cpu_to_le32(rq_to_rnbd_flags(rq));
|
|
msg.prio = cpu_to_le16(req_get_ioprio(rq));
|
|
|
|
/*
|
|
* We only support discards with single segment for now.
|
|
* See queue limits.
|
|
*/
|
|
if (req_op(rq) != REQ_OP_DISCARD)
|
|
sg_cnt = blk_rq_map_sg(dev->queue, rq, iu->sgt.sgl);
|
|
|
|
if (sg_cnt == 0)
|
|
sg_mark_end(&iu->sgt.sgl[0]);
|
|
|
|
msg.hdr.type = cpu_to_le16(RNBD_MSG_IO);
|
|
msg.device_id = cpu_to_le32(dev->device_id);
|
|
|
|
vec = (struct kvec) {
|
|
.iov_base = &msg,
|
|
.iov_len = sizeof(msg)
|
|
};
|
|
size = rnbd_clt_get_sg_size(iu->sgt.sgl, sg_cnt);
|
|
req_ops = (struct rtrs_clt_req_ops) {
|
|
.priv = iu,
|
|
.conf_fn = msg_io_conf,
|
|
};
|
|
err = rtrs_clt_request(rq_data_dir(rq), &req_ops, rtrs, permit,
|
|
&vec, 1, size, iu->sgt.sgl, sg_cnt);
|
|
if (err) {
|
|
rnbd_clt_err_rl(dev, "RTRS failed to transfer IO, err: %d\n",
|
|
err);
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* rnbd_clt_dev_add_to_requeue() - add device to requeue if session is busy
|
|
* @dev: Device to be checked
|
|
* @q: Queue to be added to the requeue list if required
|
|
*
|
|
* 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 bool rnbd_clt_dev_add_to_requeue(struct rnbd_clt_dev *dev,
|
|
struct rnbd_queue *q)
|
|
{
|
|
struct rnbd_clt_session *sess = dev->sess;
|
|
struct rnbd_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 (!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 rnbd_put_permit(). Set a bit first
|
|
* and then observe the busy counter.
|
|
*/
|
|
smp_mb__before_atomic();
|
|
}
|
|
if (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 rnbd_clt_dev_kick_mq_queue(struct rnbd_clt_dev *dev,
|
|
struct blk_mq_hw_ctx *hctx,
|
|
int delay)
|
|
{
|
|
struct rnbd_queue *q = hctx->driver_data;
|
|
|
|
if (delay != RNBD_DELAY_IFBUSY)
|
|
blk_mq_delay_run_hw_queue(hctx, delay);
|
|
else if (!rnbd_clt_dev_add_to_requeue(dev, q))
|
|
/*
|
|
* If session is not busy we have to restart
|
|
* the queue ourselves.
|
|
*/
|
|
blk_mq_delay_run_hw_queue(hctx, 10/*ms*/);
|
|
}
|
|
|
|
static blk_status_t rnbd_queue_rq(struct blk_mq_hw_ctx *hctx,
|
|
const struct blk_mq_queue_data *bd)
|
|
{
|
|
struct request *rq = bd->rq;
|
|
struct rnbd_clt_dev *dev = rq->rq_disk->private_data;
|
|
struct rnbd_iu *iu = blk_mq_rq_to_pdu(rq);
|
|
int err;
|
|
blk_status_t ret = BLK_STS_IOERR;
|
|
|
|
if (dev->dev_state != DEV_STATE_MAPPED)
|
|
return BLK_STS_IOERR;
|
|
|
|
iu->permit = rnbd_get_permit(dev->sess, RTRS_IO_CON,
|
|
RTRS_PERMIT_NOWAIT);
|
|
if (!iu->permit) {
|
|
rnbd_clt_dev_kick_mq_queue(dev, hctx, RNBD_DELAY_IFBUSY);
|
|
return BLK_STS_RESOURCE;
|
|
}
|
|
|
|
iu->sgt.sgl = iu->first_sgl;
|
|
err = sg_alloc_table_chained(&iu->sgt,
|
|
/* Even-if the request has no segment,
|
|
* sglist must have one entry at least.
|
|
*/
|
|
blk_rq_nr_phys_segments(rq) ? : 1,
|
|
iu->sgt.sgl,
|
|
RNBD_INLINE_SG_CNT);
|
|
if (err) {
|
|
rnbd_clt_err_rl(dev, "sg_alloc_table_chained ret=%d\n", err);
|
|
rnbd_clt_dev_kick_mq_queue(dev, hctx, 10/*ms*/);
|
|
rnbd_put_permit(dev->sess, iu->permit);
|
|
return BLK_STS_RESOURCE;
|
|
}
|
|
|
|
blk_mq_start_request(rq);
|
|
err = rnbd_client_xfer_request(dev, rq, iu);
|
|
if (err == 0)
|
|
return BLK_STS_OK;
|
|
if (err == -EAGAIN || err == -ENOMEM) {
|
|
rnbd_clt_dev_kick_mq_queue(dev, hctx, 10/*ms*/);
|
|
ret = BLK_STS_RESOURCE;
|
|
}
|
|
sg_free_table_chained(&iu->sgt, RNBD_INLINE_SG_CNT);
|
|
rnbd_put_permit(dev->sess, iu->permit);
|
|
return ret;
|
|
}
|
|
|
|
static int rnbd_rdma_poll(struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
struct rnbd_queue *q = hctx->driver_data;
|
|
struct rnbd_clt_dev *dev = q->dev;
|
|
int cnt;
|
|
|
|
cnt = rtrs_clt_rdma_cq_direct(dev->sess->rtrs, hctx->queue_num);
|
|
return cnt;
|
|
}
|
|
|
|
static int rnbd_rdma_map_queues(struct blk_mq_tag_set *set)
|
|
{
|
|
struct rnbd_clt_session *sess = set->driver_data;
|
|
|
|
/* shared read/write queues */
|
|
set->map[HCTX_TYPE_DEFAULT].nr_queues = num_online_cpus();
|
|
set->map[HCTX_TYPE_DEFAULT].queue_offset = 0;
|
|
set->map[HCTX_TYPE_READ].nr_queues = num_online_cpus();
|
|
set->map[HCTX_TYPE_READ].queue_offset = 0;
|
|
blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
|
|
blk_mq_map_queues(&set->map[HCTX_TYPE_READ]);
|
|
|
|
if (sess->nr_poll_queues) {
|
|
/* dedicated queue for poll */
|
|
set->map[HCTX_TYPE_POLL].nr_queues = sess->nr_poll_queues;
|
|
set->map[HCTX_TYPE_POLL].queue_offset = set->map[HCTX_TYPE_READ].queue_offset +
|
|
set->map[HCTX_TYPE_READ].nr_queues;
|
|
blk_mq_map_queues(&set->map[HCTX_TYPE_POLL]);
|
|
pr_info("[session=%s] mapped %d/%d/%d default/read/poll queues.\n",
|
|
sess->sessname,
|
|
set->map[HCTX_TYPE_DEFAULT].nr_queues,
|
|
set->map[HCTX_TYPE_READ].nr_queues,
|
|
set->map[HCTX_TYPE_POLL].nr_queues);
|
|
} else {
|
|
pr_info("[session=%s] mapped %d/%d default/read queues.\n",
|
|
sess->sessname,
|
|
set->map[HCTX_TYPE_DEFAULT].nr_queues,
|
|
set->map[HCTX_TYPE_READ].nr_queues);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct blk_mq_ops rnbd_mq_ops = {
|
|
.queue_rq = rnbd_queue_rq,
|
|
.complete = rnbd_softirq_done_fn,
|
|
.map_queues = rnbd_rdma_map_queues,
|
|
.poll = rnbd_rdma_poll,
|
|
};
|
|
|
|
static int setup_mq_tags(struct rnbd_clt_session *sess)
|
|
{
|
|
struct blk_mq_tag_set *tag_set = &sess->tag_set;
|
|
|
|
memset(tag_set, 0, sizeof(*tag_set));
|
|
tag_set->ops = &rnbd_mq_ops;
|
|
tag_set->queue_depth = sess->queue_depth;
|
|
tag_set->numa_node = NUMA_NO_NODE;
|
|
tag_set->flags = BLK_MQ_F_SHOULD_MERGE |
|
|
BLK_MQ_F_TAG_QUEUE_SHARED;
|
|
tag_set->cmd_size = sizeof(struct rnbd_iu) + RNBD_RDMA_SGL_SIZE;
|
|
|
|
/* for HCTX_TYPE_DEFAULT, HCTX_TYPE_READ, HCTX_TYPE_POLL */
|
|
tag_set->nr_maps = sess->nr_poll_queues ? HCTX_MAX_TYPES : 2;
|
|
/*
|
|
* HCTX_TYPE_DEFAULT and HCTX_TYPE_READ share one set of queues
|
|
* others are for HCTX_TYPE_POLL
|
|
*/
|
|
tag_set->nr_hw_queues = num_online_cpus() + sess->nr_poll_queues;
|
|
tag_set->driver_data = sess;
|
|
|
|
return blk_mq_alloc_tag_set(tag_set);
|
|
}
|
|
|
|
static struct rnbd_clt_session *
|
|
find_and_get_or_create_sess(const char *sessname,
|
|
const struct rtrs_addr *paths,
|
|
size_t path_cnt, u16 port_nr, u32 nr_poll_queues)
|
|
{
|
|
struct rnbd_clt_session *sess;
|
|
struct rtrs_attrs attrs;
|
|
int err;
|
|
bool first = false;
|
|
struct rtrs_clt_ops rtrs_ops;
|
|
|
|
sess = find_or_create_sess(sessname, &first);
|
|
if (sess == ERR_PTR(-ENOMEM))
|
|
return ERR_PTR(-ENOMEM);
|
|
else if ((nr_poll_queues && !first) || (!nr_poll_queues && sess->nr_poll_queues)) {
|
|
/*
|
|
* A device MUST have its own session to use the polling-mode.
|
|
* It must fail to map new device with the same session.
|
|
*/
|
|
err = -EINVAL;
|
|
goto put_sess;
|
|
}
|
|
|
|
if (!first)
|
|
return sess;
|
|
|
|
if (!path_cnt) {
|
|
pr_err("Session %s not found, and path parameter not given", sessname);
|
|
err = -ENXIO;
|
|
goto put_sess;
|
|
}
|
|
|
|
rtrs_ops = (struct rtrs_clt_ops) {
|
|
.priv = sess,
|
|
.link_ev = rnbd_clt_link_ev,
|
|
};
|
|
/*
|
|
* Nothing was found, establish rtrs connection and proceed further.
|
|
*/
|
|
sess->rtrs = rtrs_clt_open(&rtrs_ops, sessname,
|
|
paths, path_cnt, port_nr,
|
|
0, /* Do not use pdu of rtrs */
|
|
RECONNECT_DELAY, BMAX_SEGMENTS,
|
|
MAX_RECONNECTS, nr_poll_queues);
|
|
if (IS_ERR(sess->rtrs)) {
|
|
err = PTR_ERR(sess->rtrs);
|
|
goto wake_up_and_put;
|
|
}
|
|
|
|
err = rtrs_clt_query(sess->rtrs, &attrs);
|
|
if (err)
|
|
goto close_rtrs;
|
|
|
|
sess->max_io_size = attrs.max_io_size;
|
|
sess->queue_depth = attrs.queue_depth;
|
|
sess->nr_poll_queues = nr_poll_queues;
|
|
|
|
err = setup_mq_tags(sess);
|
|
if (err)
|
|
goto close_rtrs;
|
|
|
|
err = send_msg_sess_info(sess, RTRS_PERMIT_WAIT);
|
|
if (err)
|
|
goto close_rtrs;
|
|
|
|
wake_up_rtrs_waiters(sess);
|
|
|
|
return sess;
|
|
|
|
close_rtrs:
|
|
close_rtrs(sess);
|
|
put_sess:
|
|
rnbd_clt_put_sess(sess);
|
|
|
|
return ERR_PTR(err);
|
|
|
|
wake_up_and_put:
|
|
wake_up_rtrs_waiters(sess);
|
|
goto put_sess;
|
|
}
|
|
|
|
static inline void rnbd_init_hw_queue(struct rnbd_clt_dev *dev,
|
|
struct rnbd_queue *q,
|
|
struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
INIT_LIST_HEAD(&q->requeue_list);
|
|
q->dev = dev;
|
|
q->hctx = hctx;
|
|
}
|
|
|
|
static void rnbd_init_mq_hw_queues(struct rnbd_clt_dev *dev)
|
|
{
|
|
int i;
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct rnbd_queue *q;
|
|
|
|
queue_for_each_hw_ctx(dev->queue, hctx, i) {
|
|
q = &dev->hw_queues[i];
|
|
rnbd_init_hw_queue(dev, q, hctx);
|
|
hctx->driver_data = q;
|
|
}
|
|
}
|
|
|
|
static int setup_mq_dev(struct rnbd_clt_dev *dev)
|
|
{
|
|
dev->queue = blk_mq_init_queue(&dev->sess->tag_set);
|
|
if (IS_ERR(dev->queue)) {
|
|
rnbd_clt_err(dev, "Initializing multiqueue queue failed, err: %ld\n",
|
|
PTR_ERR(dev->queue));
|
|
return PTR_ERR(dev->queue);
|
|
}
|
|
rnbd_init_mq_hw_queues(dev);
|
|
return 0;
|
|
}
|
|
|
|
static void setup_request_queue(struct rnbd_clt_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);
|
|
|
|
/*
|
|
* we don't support discards to "discontiguous" segments
|
|
* in on request
|
|
*/
|
|
blk_queue_max_discard_segments(dev->queue, 1);
|
|
|
|
blk_queue_max_discard_sectors(dev->queue, dev->max_discard_sectors);
|
|
dev->queue->limits.discard_granularity = dev->discard_granularity;
|
|
dev->queue->limits.discard_alignment = dev->discard_alignment;
|
|
if (dev->max_discard_sectors)
|
|
blk_queue_flag_set(QUEUE_FLAG_DISCARD, dev->queue);
|
|
if (dev->secure_discard)
|
|
blk_queue_flag_set(QUEUE_FLAG_SECERASE, dev->queue);
|
|
|
|
blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, dev->queue);
|
|
blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, dev->queue);
|
|
blk_queue_max_segments(dev->queue, dev->max_segments);
|
|
blk_queue_io_opt(dev->queue, dev->sess->max_io_size);
|
|
blk_queue_virt_boundary(dev->queue, SZ_4K - 1);
|
|
blk_queue_write_cache(dev->queue, dev->wc, dev->fua);
|
|
dev->queue->queuedata = dev;
|
|
}
|
|
|
|
static void rnbd_clt_setup_gen_disk(struct rnbd_clt_dev *dev, int idx)
|
|
{
|
|
dev->gd->major = rnbd_client_major;
|
|
dev->gd->first_minor = idx << RNBD_PART_BITS;
|
|
dev->gd->fops = &rnbd_client_ops;
|
|
dev->gd->queue = dev->queue;
|
|
dev->gd->private_data = dev;
|
|
snprintf(dev->gd->disk_name, sizeof(dev->gd->disk_name), "rnbd%d",
|
|
idx);
|
|
pr_debug("disk_name=%s, capacity=%zu\n",
|
|
dev->gd->disk_name,
|
|
dev->nsectors * (dev->logical_block_size / SECTOR_SIZE)
|
|
);
|
|
|
|
set_capacity(dev->gd, dev->nsectors);
|
|
|
|
if (dev->access_mode == RNBD_ACCESS_RO) {
|
|
dev->read_only = true;
|
|
set_disk_ro(dev->gd, true);
|
|
} else {
|
|
dev->read_only = false;
|
|
}
|
|
|
|
if (!dev->rotational)
|
|
blk_queue_flag_set(QUEUE_FLAG_NONROT, dev->queue);
|
|
add_disk(dev->gd);
|
|
}
|
|
|
|
static int rnbd_client_setup_device(struct rnbd_clt_dev *dev)
|
|
{
|
|
int err, idx = dev->clt_device_id;
|
|
|
|
dev->size = dev->nsectors * dev->logical_block_size;
|
|
|
|
err = setup_mq_dev(dev);
|
|
if (err)
|
|
return err;
|
|
|
|
setup_request_queue(dev);
|
|
|
|
dev->gd = alloc_disk_node(1 << RNBD_PART_BITS, NUMA_NO_NODE);
|
|
if (!dev->gd) {
|
|
blk_cleanup_queue(dev->queue);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
rnbd_clt_setup_gen_disk(dev, idx);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct rnbd_clt_dev *init_dev(struct rnbd_clt_session *sess,
|
|
enum rnbd_access_mode access_mode,
|
|
const char *pathname,
|
|
u32 nr_poll_queues)
|
|
{
|
|
struct rnbd_clt_dev *dev;
|
|
int ret;
|
|
|
|
dev = kzalloc_node(sizeof(*dev), GFP_KERNEL, NUMA_NO_NODE);
|
|
if (!dev)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
/*
|
|
* nr_cpu_ids: the number of softirq queues
|
|
* nr_poll_queues: the number of polling queues
|
|
*/
|
|
dev->hw_queues = kcalloc(nr_cpu_ids + nr_poll_queues,
|
|
sizeof(*dev->hw_queues),
|
|
GFP_KERNEL);
|
|
if (!dev->hw_queues) {
|
|
ret = -ENOMEM;
|
|
goto out_alloc;
|
|
}
|
|
|
|
mutex_lock(&ida_lock);
|
|
ret = ida_simple_get(&index_ida, 0, 1 << (MINORBITS - RNBD_PART_BITS),
|
|
GFP_KERNEL);
|
|
mutex_unlock(&ida_lock);
|
|
if (ret < 0) {
|
|
pr_err("Failed to initialize device '%s' from session %s, allocating idr failed, err: %d\n",
|
|
pathname, sess->sessname, ret);
|
|
goto out_queues;
|
|
}
|
|
|
|
dev->pathname = kstrdup(pathname, GFP_KERNEL);
|
|
if (!dev->pathname) {
|
|
ret = -ENOMEM;
|
|
goto out_queues;
|
|
}
|
|
|
|
dev->clt_device_id = ret;
|
|
dev->sess = sess;
|
|
dev->access_mode = access_mode;
|
|
dev->nr_poll_queues = nr_poll_queues;
|
|
mutex_init(&dev->lock);
|
|
refcount_set(&dev->refcount, 1);
|
|
dev->dev_state = DEV_STATE_INIT;
|
|
|
|
/*
|
|
* Here we called from sysfs entry, thus clt-sysfs is
|
|
* responsible that session will not disappear.
|
|
*/
|
|
WARN_ON(!rnbd_clt_get_sess(sess));
|
|
|
|
return dev;
|
|
|
|
out_queues:
|
|
kfree(dev->hw_queues);
|
|
out_alloc:
|
|
kfree(dev);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
static bool __exists_dev(const char *pathname, const char *sessname)
|
|
{
|
|
struct rnbd_clt_session *sess;
|
|
struct rnbd_clt_dev *dev;
|
|
bool found = false;
|
|
|
|
list_for_each_entry(sess, &sess_list, list) {
|
|
if (sessname && strncmp(sess->sessname, sessname,
|
|
sizeof(sess->sessname)))
|
|
continue;
|
|
mutex_lock(&sess->lock);
|
|
list_for_each_entry(dev, &sess->devs_list, list) {
|
|
if (strlen(dev->pathname) == strlen(pathname) &&
|
|
!strcmp(dev->pathname, pathname)) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
mutex_unlock(&sess->lock);
|
|
if (found)
|
|
break;
|
|
}
|
|
|
|
return found;
|
|
}
|
|
|
|
static bool exists_devpath(const char *pathname, const char *sessname)
|
|
{
|
|
bool found;
|
|
|
|
mutex_lock(&sess_lock);
|
|
found = __exists_dev(pathname, sessname);
|
|
mutex_unlock(&sess_lock);
|
|
|
|
return found;
|
|
}
|
|
|
|
static bool insert_dev_if_not_exists_devpath(struct rnbd_clt_dev *dev)
|
|
{
|
|
bool found;
|
|
struct rnbd_clt_session *sess = dev->sess;
|
|
|
|
mutex_lock(&sess_lock);
|
|
found = __exists_dev(dev->pathname, sess->sessname);
|
|
if (!found) {
|
|
mutex_lock(&sess->lock);
|
|
list_add_tail(&dev->list, &sess->devs_list);
|
|
mutex_unlock(&sess->lock);
|
|
}
|
|
mutex_unlock(&sess_lock);
|
|
|
|
return found;
|
|
}
|
|
|
|
static void delete_dev(struct rnbd_clt_dev *dev)
|
|
{
|
|
struct rnbd_clt_session *sess = dev->sess;
|
|
|
|
mutex_lock(&sess->lock);
|
|
list_del(&dev->list);
|
|
mutex_unlock(&sess->lock);
|
|
}
|
|
|
|
struct rnbd_clt_dev *rnbd_clt_map_device(const char *sessname,
|
|
struct rtrs_addr *paths,
|
|
size_t path_cnt, u16 port_nr,
|
|
const char *pathname,
|
|
enum rnbd_access_mode access_mode,
|
|
u32 nr_poll_queues)
|
|
{
|
|
struct rnbd_clt_session *sess;
|
|
struct rnbd_clt_dev *dev;
|
|
int ret;
|
|
|
|
if (exists_devpath(pathname, sessname))
|
|
return ERR_PTR(-EEXIST);
|
|
|
|
sess = find_and_get_or_create_sess(sessname, paths, path_cnt, port_nr, nr_poll_queues);
|
|
if (IS_ERR(sess))
|
|
return ERR_CAST(sess);
|
|
|
|
dev = init_dev(sess, access_mode, pathname, nr_poll_queues);
|
|
if (IS_ERR(dev)) {
|
|
pr_err("map_device: failed to map device '%s' from session %s, can't initialize device, err: %ld\n",
|
|
pathname, sess->sessname, PTR_ERR(dev));
|
|
ret = PTR_ERR(dev);
|
|
goto put_sess;
|
|
}
|
|
if (insert_dev_if_not_exists_devpath(dev)) {
|
|
ret = -EEXIST;
|
|
goto put_dev;
|
|
}
|
|
ret = send_msg_open(dev, RTRS_PERMIT_WAIT);
|
|
if (ret) {
|
|
rnbd_clt_err(dev,
|
|
"map_device: failed, can't open remote device, err: %d\n",
|
|
ret);
|
|
goto del_dev;
|
|
}
|
|
mutex_lock(&dev->lock);
|
|
pr_debug("Opened remote device: session=%s, path='%s'\n",
|
|
sess->sessname, pathname);
|
|
ret = rnbd_client_setup_device(dev);
|
|
if (ret) {
|
|
rnbd_clt_err(dev,
|
|
"map_device: Failed to configure device, err: %d\n",
|
|
ret);
|
|
mutex_unlock(&dev->lock);
|
|
goto send_close;
|
|
}
|
|
|
|
rnbd_clt_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_granularity: %d, discard_alignment: %d, secure_discard: %d, max_segments: %d, max_hw_sectors: %d, rotational: %d, wc: %d, fua: %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_granularity, dev->discard_alignment,
|
|
dev->secure_discard, dev->max_segments,
|
|
dev->max_hw_sectors, dev->rotational, dev->wc, dev->fua);
|
|
|
|
mutex_unlock(&dev->lock);
|
|
rnbd_clt_put_sess(sess);
|
|
|
|
return dev;
|
|
|
|
send_close:
|
|
send_msg_close(dev, dev->device_id, RTRS_PERMIT_WAIT);
|
|
del_dev:
|
|
delete_dev(dev);
|
|
put_dev:
|
|
rnbd_clt_put_dev(dev);
|
|
put_sess:
|
|
rnbd_clt_put_sess(sess);
|
|
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
static void destroy_gen_disk(struct rnbd_clt_dev *dev)
|
|
{
|
|
del_gendisk(dev->gd);
|
|
blk_cleanup_queue(dev->queue);
|
|
put_disk(dev->gd);
|
|
}
|
|
|
|
static void destroy_sysfs(struct rnbd_clt_dev *dev,
|
|
const struct attribute *sysfs_self)
|
|
{
|
|
rnbd_clt_remove_dev_symlink(dev);
|
|
if (dev->kobj.state_initialized) {
|
|
if (sysfs_self)
|
|
/* To avoid deadlock firstly remove itself */
|
|
sysfs_remove_file_self(&dev->kobj, sysfs_self);
|
|
kobject_del(&dev->kobj);
|
|
kobject_put(&dev->kobj);
|
|
}
|
|
}
|
|
|
|
int rnbd_clt_unmap_device(struct rnbd_clt_dev *dev, bool force,
|
|
const struct attribute *sysfs_self)
|
|
{
|
|
struct rnbd_clt_session *sess = dev->sess;
|
|
int refcount, ret = 0;
|
|
bool was_mapped;
|
|
|
|
mutex_lock(&dev->lock);
|
|
if (dev->dev_state == DEV_STATE_UNMAPPED) {
|
|
rnbd_clt_info(dev, "Device is already being unmapped\n");
|
|
ret = -EALREADY;
|
|
goto err;
|
|
}
|
|
refcount = refcount_read(&dev->refcount);
|
|
if (!force && refcount > 1) {
|
|
rnbd_clt_err(dev,
|
|
"Closing device failed, device is in use, (%d device users)\n",
|
|
refcount - 1);
|
|
ret = -EBUSY;
|
|
goto err;
|
|
}
|
|
was_mapped = (dev->dev_state == DEV_STATE_MAPPED);
|
|
dev->dev_state = DEV_STATE_UNMAPPED;
|
|
mutex_unlock(&dev->lock);
|
|
|
|
delete_dev(dev);
|
|
destroy_sysfs(dev, sysfs_self);
|
|
destroy_gen_disk(dev);
|
|
if (was_mapped && sess->rtrs)
|
|
send_msg_close(dev, dev->device_id, RTRS_PERMIT_WAIT);
|
|
|
|
rnbd_clt_info(dev, "Device is unmapped\n");
|
|
|
|
/* Likely last reference put */
|
|
rnbd_clt_put_dev(dev);
|
|
|
|
/*
|
|
* Here device and session can be vanished!
|
|
*/
|
|
|
|
return 0;
|
|
err:
|
|
mutex_unlock(&dev->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int rnbd_clt_remap_device(struct rnbd_clt_dev *dev)
|
|
{
|
|
int err;
|
|
|
|
mutex_lock(&dev->lock);
|
|
if (dev->dev_state == DEV_STATE_MAPPED_DISCONNECTED)
|
|
err = 0;
|
|
else if (dev->dev_state == DEV_STATE_UNMAPPED)
|
|
err = -ENODEV;
|
|
else if (dev->dev_state == DEV_STATE_MAPPED)
|
|
err = -EALREADY;
|
|
else
|
|
err = -EBUSY;
|
|
mutex_unlock(&dev->lock);
|
|
if (!err) {
|
|
rnbd_clt_info(dev, "Remapping device.\n");
|
|
err = send_msg_open(dev, RTRS_PERMIT_WAIT);
|
|
if (err)
|
|
rnbd_clt_err(dev, "remap_device: %d\n", err);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static void unmap_device_work(struct work_struct *work)
|
|
{
|
|
struct rnbd_clt_dev *dev;
|
|
|
|
dev = container_of(work, typeof(*dev), unmap_on_rmmod_work);
|
|
rnbd_clt_unmap_device(dev, true, NULL);
|
|
}
|
|
|
|
static void rnbd_destroy_sessions(void)
|
|
{
|
|
struct rnbd_clt_session *sess, *sn;
|
|
struct rnbd_clt_dev *dev, *tn;
|
|
|
|
/* Firstly forbid access through sysfs interface */
|
|
rnbd_clt_destroy_sysfs_files();
|
|
|
|
/*
|
|
* Here at this point there is no any concurrent access to sessions
|
|
* list and devices list:
|
|
* 1. New session or device can't be created - session sysfs files
|
|
* are removed.
|
|
* 2. Device or session can't be removed - module reference is taken
|
|
* into account in unmap device sysfs callback.
|
|
* 3. No IO requests inflight - each file open of block_dev increases
|
|
* module reference in get_disk().
|
|
*
|
|
* But still there can be user requests inflights, which are sent by
|
|
* asynchronous send_msg_*() functions, thus before unmapping devices
|
|
* RTRS session must be explicitly closed.
|
|
*/
|
|
|
|
list_for_each_entry_safe(sess, sn, &sess_list, list) {
|
|
if (!rnbd_clt_get_sess(sess))
|
|
continue;
|
|
close_rtrs(sess);
|
|
list_for_each_entry_safe(dev, tn, &sess->devs_list, list) {
|
|
/*
|
|
* Here unmap happens in parallel for only one reason:
|
|
* blk_cleanup_queue() takes around half a second, so
|
|
* on huge amount of devices the whole module unload
|
|
* procedure takes minutes.
|
|
*/
|
|
INIT_WORK(&dev->unmap_on_rmmod_work, unmap_device_work);
|
|
queue_work(system_long_wq, &dev->unmap_on_rmmod_work);
|
|
}
|
|
rnbd_clt_put_sess(sess);
|
|
}
|
|
/* Wait for all scheduled unmap works */
|
|
flush_workqueue(system_long_wq);
|
|
WARN_ON(!list_empty(&sess_list));
|
|
}
|
|
|
|
static int __init rnbd_client_init(void)
|
|
{
|
|
int err = 0;
|
|
|
|
BUILD_BUG_ON(sizeof(struct rnbd_msg_hdr) != 4);
|
|
BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info) != 36);
|
|
BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info_rsp) != 36);
|
|
BUILD_BUG_ON(sizeof(struct rnbd_msg_open) != 264);
|
|
BUILD_BUG_ON(sizeof(struct rnbd_msg_close) != 8);
|
|
BUILD_BUG_ON(sizeof(struct rnbd_msg_open_rsp) != 56);
|
|
rnbd_client_major = register_blkdev(rnbd_client_major, "rnbd");
|
|
if (rnbd_client_major <= 0) {
|
|
pr_err("Failed to load module, block device registration failed\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
err = rnbd_clt_create_sysfs_files();
|
|
if (err) {
|
|
pr_err("Failed to load module, creating sysfs device files failed, err: %d\n",
|
|
err);
|
|
unregister_blkdev(rnbd_client_major, "rnbd");
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static void __exit rnbd_client_exit(void)
|
|
{
|
|
rnbd_destroy_sessions();
|
|
unregister_blkdev(rnbd_client_major, "rnbd");
|
|
ida_destroy(&index_ida);
|
|
}
|
|
|
|
module_init(rnbd_client_init);
|
|
module_exit(rnbd_client_exit);
|