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e6190dd003
In ublk_queue_rq(), Assume current request is a re-issued request aborted previously in monitor_work because the ubq_daemon(ioucmd's task) is PF_EXITING. For this request, we cannot call io_uring_cmd_complete_in_task() anymore because at that moment io_uring context may be freed in case that no inflight ioucmd exists. Otherwise, we may cause null-deref in ctx->fallback_work. Add a check on UBLK_IO_FLAG_ABORTED to prevent the above situation. This check is safe and makes sense. Note: monitor_work sets UBLK_IO_FLAG_ABORTED and ends this request (releasing the tag). Then the request is restarted(allocating the tag) and we are here. Since releasing/allocating a tag implies smp_mb(), finding UBLK_IO_FLAG_ABORTED guarantees that here is a re-issued request aborted previously. Suggested-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220815023633.259825-4-ZiyangZhang@linux.alibaba.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
1825 lines
44 KiB
C
1825 lines
44 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Userspace block device - block device which IO is handled from userspace
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*
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* Take full use of io_uring passthrough command for communicating with
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* ublk userspace daemon(ublksrvd) for handling basic IO request.
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*
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* Copyright 2022 Ming Lei <ming.lei@redhat.com>
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*
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* (part of code stolen from loop.c)
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/sched.h>
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#include <linux/fs.h>
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#include <linux/pagemap.h>
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#include <linux/file.h>
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#include <linux/stat.h>
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#include <linux/errno.h>
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#include <linux/major.h>
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#include <linux/wait.h>
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#include <linux/blkdev.h>
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#include <linux/init.h>
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#include <linux/swap.h>
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#include <linux/slab.h>
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#include <linux/compat.h>
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#include <linux/mutex.h>
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#include <linux/writeback.h>
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#include <linux/completion.h>
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#include <linux/highmem.h>
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#include <linux/sysfs.h>
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#include <linux/miscdevice.h>
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#include <linux/falloc.h>
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#include <linux/uio.h>
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#include <linux/ioprio.h>
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#include <linux/sched/mm.h>
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#include <linux/uaccess.h>
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#include <linux/cdev.h>
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#include <linux/io_uring.h>
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#include <linux/blk-mq.h>
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#include <linux/delay.h>
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#include <linux/mm.h>
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#include <asm/page.h>
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#include <linux/task_work.h>
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#include <uapi/linux/ublk_cmd.h>
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#define UBLK_MINORS (1U << MINORBITS)
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/* All UBLK_F_* have to be included into UBLK_F_ALL */
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#define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY \
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| UBLK_F_URING_CMD_COMP_IN_TASK \
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| UBLK_F_NEED_GET_DATA)
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/* All UBLK_PARAM_TYPE_* should be included here */
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#define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD)
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struct ublk_rq_data {
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struct callback_head work;
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};
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struct ublk_uring_cmd_pdu {
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struct request *req;
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};
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/*
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* io command is active: sqe cmd is received, and its cqe isn't done
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*
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* If the flag is set, the io command is owned by ublk driver, and waited
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* for incoming blk-mq request from the ublk block device.
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*
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* If the flag is cleared, the io command will be completed, and owned by
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* ublk server.
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*/
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#define UBLK_IO_FLAG_ACTIVE 0x01
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/*
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* IO command is completed via cqe, and it is being handled by ublksrv, and
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* not committed yet
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*
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* Basically exclusively with UBLK_IO_FLAG_ACTIVE, so can be served for
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* cross verification
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*/
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#define UBLK_IO_FLAG_OWNED_BY_SRV 0x02
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/*
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* IO command is aborted, so this flag is set in case of
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* !UBLK_IO_FLAG_ACTIVE.
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*
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* After this flag is observed, any pending or new incoming request
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* associated with this io command will be failed immediately
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*/
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#define UBLK_IO_FLAG_ABORTED 0x04
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/*
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* UBLK_IO_FLAG_NEED_GET_DATA is set because IO command requires
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* get data buffer address from ublksrv.
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*
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* Then, bio data could be copied into this data buffer for a WRITE request
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* after the IO command is issued again and UBLK_IO_FLAG_NEED_GET_DATA is unset.
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*/
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#define UBLK_IO_FLAG_NEED_GET_DATA 0x08
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struct ublk_io {
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/* userspace buffer address from io cmd */
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__u64 addr;
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unsigned int flags;
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int res;
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struct io_uring_cmd *cmd;
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};
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struct ublk_queue {
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int q_id;
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int q_depth;
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unsigned long flags;
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struct task_struct *ubq_daemon;
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char *io_cmd_buf;
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unsigned long io_addr; /* mapped vm address */
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unsigned int max_io_sz;
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bool abort_work_pending;
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unsigned short nr_io_ready; /* how many ios setup */
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struct ublk_device *dev;
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struct ublk_io ios[0];
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};
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#define UBLK_DAEMON_MONITOR_PERIOD (5 * HZ)
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struct ublk_device {
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struct gendisk *ub_disk;
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char *__queues;
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unsigned short queue_size;
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struct ublksrv_ctrl_dev_info dev_info;
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struct blk_mq_tag_set tag_set;
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struct cdev cdev;
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struct device cdev_dev;
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#define UB_STATE_OPEN 0
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#define UB_STATE_USED 1
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unsigned long state;
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int ub_number;
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struct mutex mutex;
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spinlock_t mm_lock;
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struct mm_struct *mm;
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struct ublk_params params;
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struct completion completion;
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unsigned int nr_queues_ready;
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atomic_t nr_aborted_queues;
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/*
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* Our ubq->daemon may be killed without any notification, so
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* monitor each queue's daemon periodically
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*/
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struct delayed_work monitor_work;
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struct work_struct stop_work;
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};
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/* header of ublk_params */
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struct ublk_params_header {
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__u32 len;
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__u32 types;
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};
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static dev_t ublk_chr_devt;
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static struct class *ublk_chr_class;
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static DEFINE_IDR(ublk_index_idr);
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static DEFINE_SPINLOCK(ublk_idr_lock);
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static wait_queue_head_t ublk_idr_wq; /* wait until one idr is freed */
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static DEFINE_MUTEX(ublk_ctl_mutex);
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static struct miscdevice ublk_misc;
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static void ublk_dev_param_basic_apply(struct ublk_device *ub)
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{
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struct request_queue *q = ub->ub_disk->queue;
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const struct ublk_param_basic *p = &ub->params.basic;
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blk_queue_logical_block_size(q, 1 << p->logical_bs_shift);
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blk_queue_physical_block_size(q, 1 << p->physical_bs_shift);
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blk_queue_io_min(q, 1 << p->io_min_shift);
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blk_queue_io_opt(q, 1 << p->io_opt_shift);
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blk_queue_write_cache(q, p->attrs & UBLK_ATTR_VOLATILE_CACHE,
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p->attrs & UBLK_ATTR_FUA);
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if (p->attrs & UBLK_ATTR_ROTATIONAL)
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blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
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else
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blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
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blk_queue_max_hw_sectors(q, p->max_sectors);
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blk_queue_chunk_sectors(q, p->chunk_sectors);
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blk_queue_virt_boundary(q, p->virt_boundary_mask);
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if (p->attrs & UBLK_ATTR_READ_ONLY)
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set_disk_ro(ub->ub_disk, true);
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set_capacity(ub->ub_disk, p->dev_sectors);
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}
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static void ublk_dev_param_discard_apply(struct ublk_device *ub)
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{
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struct request_queue *q = ub->ub_disk->queue;
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const struct ublk_param_discard *p = &ub->params.discard;
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q->limits.discard_alignment = p->discard_alignment;
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q->limits.discard_granularity = p->discard_granularity;
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blk_queue_max_discard_sectors(q, p->max_discard_sectors);
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blk_queue_max_write_zeroes_sectors(q,
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p->max_write_zeroes_sectors);
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blk_queue_max_discard_segments(q, p->max_discard_segments);
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}
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static int ublk_validate_params(const struct ublk_device *ub)
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{
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/* basic param is the only one which must be set */
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if (ub->params.types & UBLK_PARAM_TYPE_BASIC) {
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const struct ublk_param_basic *p = &ub->params.basic;
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if (p->logical_bs_shift > PAGE_SHIFT)
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return -EINVAL;
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if (p->logical_bs_shift > p->physical_bs_shift)
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return -EINVAL;
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if (p->max_sectors > (ub->dev_info.max_io_buf_bytes >> 9))
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return -EINVAL;
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} else
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return -EINVAL;
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if (ub->params.types & UBLK_PARAM_TYPE_DISCARD) {
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const struct ublk_param_discard *p = &ub->params.discard;
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/* So far, only support single segment discard */
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if (p->max_discard_sectors && p->max_discard_segments != 1)
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return -EINVAL;
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if (!p->discard_granularity)
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return -EINVAL;
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}
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return 0;
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}
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static int ublk_apply_params(struct ublk_device *ub)
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{
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if (!(ub->params.types & UBLK_PARAM_TYPE_BASIC))
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return -EINVAL;
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ublk_dev_param_basic_apply(ub);
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if (ub->params.types & UBLK_PARAM_TYPE_DISCARD)
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ublk_dev_param_discard_apply(ub);
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return 0;
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}
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static inline bool ublk_can_use_task_work(const struct ublk_queue *ubq)
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{
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if (IS_BUILTIN(CONFIG_BLK_DEV_UBLK) &&
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!(ubq->flags & UBLK_F_URING_CMD_COMP_IN_TASK))
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return true;
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return false;
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}
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static inline bool ublk_need_get_data(const struct ublk_queue *ubq)
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{
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if (ubq->flags & UBLK_F_NEED_GET_DATA)
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return true;
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return false;
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}
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static struct ublk_device *ublk_get_device(struct ublk_device *ub)
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{
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if (kobject_get_unless_zero(&ub->cdev_dev.kobj))
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return ub;
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return NULL;
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}
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static void ublk_put_device(struct ublk_device *ub)
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{
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put_device(&ub->cdev_dev);
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}
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static inline struct ublk_queue *ublk_get_queue(struct ublk_device *dev,
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int qid)
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{
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return (struct ublk_queue *)&(dev->__queues[qid * dev->queue_size]);
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}
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static inline bool ublk_rq_has_data(const struct request *rq)
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{
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return rq->bio && bio_has_data(rq->bio);
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}
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static inline struct ublksrv_io_desc *ublk_get_iod(struct ublk_queue *ubq,
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int tag)
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{
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return (struct ublksrv_io_desc *)
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&(ubq->io_cmd_buf[tag * sizeof(struct ublksrv_io_desc)]);
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}
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static inline char *ublk_queue_cmd_buf(struct ublk_device *ub, int q_id)
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{
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return ublk_get_queue(ub, q_id)->io_cmd_buf;
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}
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static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id)
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{
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struct ublk_queue *ubq = ublk_get_queue(ub, q_id);
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return round_up(ubq->q_depth * sizeof(struct ublksrv_io_desc),
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PAGE_SIZE);
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}
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static void ublk_free_disk(struct gendisk *disk)
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{
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struct ublk_device *ub = disk->private_data;
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clear_bit(UB_STATE_USED, &ub->state);
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put_device(&ub->cdev_dev);
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}
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static const struct block_device_operations ub_fops = {
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.owner = THIS_MODULE,
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.free_disk = ublk_free_disk,
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};
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#define UBLK_MAX_PIN_PAGES 32
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struct ublk_map_data {
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const struct ublk_queue *ubq;
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const struct request *rq;
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const struct ublk_io *io;
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unsigned max_bytes;
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};
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struct ublk_io_iter {
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struct page *pages[UBLK_MAX_PIN_PAGES];
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unsigned pg_off; /* offset in the 1st page in pages */
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int nr_pages; /* how many page pointers in pages */
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struct bio *bio;
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struct bvec_iter iter;
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};
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static inline unsigned ublk_copy_io_pages(struct ublk_io_iter *data,
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unsigned max_bytes, bool to_vm)
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{
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const unsigned total = min_t(unsigned, max_bytes,
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PAGE_SIZE - data->pg_off +
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((data->nr_pages - 1) << PAGE_SHIFT));
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unsigned done = 0;
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unsigned pg_idx = 0;
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while (done < total) {
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struct bio_vec bv = bio_iter_iovec(data->bio, data->iter);
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const unsigned int bytes = min3(bv.bv_len, total - done,
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(unsigned)(PAGE_SIZE - data->pg_off));
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void *bv_buf = bvec_kmap_local(&bv);
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void *pg_buf = kmap_local_page(data->pages[pg_idx]);
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if (to_vm)
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memcpy(pg_buf + data->pg_off, bv_buf, bytes);
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else
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memcpy(bv_buf, pg_buf + data->pg_off, bytes);
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kunmap_local(pg_buf);
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kunmap_local(bv_buf);
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/* advance page array */
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data->pg_off += bytes;
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if (data->pg_off == PAGE_SIZE) {
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pg_idx += 1;
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data->pg_off = 0;
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}
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done += bytes;
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/* advance bio */
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bio_advance_iter_single(data->bio, &data->iter, bytes);
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if (!data->iter.bi_size) {
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data->bio = data->bio->bi_next;
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if (data->bio == NULL)
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break;
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data->iter = data->bio->bi_iter;
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}
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}
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return done;
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}
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static inline int ublk_copy_user_pages(struct ublk_map_data *data,
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bool to_vm)
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{
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const unsigned int gup_flags = to_vm ? FOLL_WRITE : 0;
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const unsigned long start_vm = data->io->addr;
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unsigned int done = 0;
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struct ublk_io_iter iter = {
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.pg_off = start_vm & (PAGE_SIZE - 1),
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.bio = data->rq->bio,
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.iter = data->rq->bio->bi_iter,
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};
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const unsigned int nr_pages = round_up(data->max_bytes +
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(start_vm & (PAGE_SIZE - 1)), PAGE_SIZE) >> PAGE_SHIFT;
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while (done < nr_pages) {
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const unsigned to_pin = min_t(unsigned, UBLK_MAX_PIN_PAGES,
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nr_pages - done);
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unsigned i, len;
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iter.nr_pages = get_user_pages_fast(start_vm +
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(done << PAGE_SHIFT), to_pin, gup_flags,
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iter.pages);
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if (iter.nr_pages <= 0)
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return done == 0 ? iter.nr_pages : done;
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len = ublk_copy_io_pages(&iter, data->max_bytes, to_vm);
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for (i = 0; i < iter.nr_pages; i++) {
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if (to_vm)
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set_page_dirty(iter.pages[i]);
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put_page(iter.pages[i]);
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}
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data->max_bytes -= len;
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done += iter.nr_pages;
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}
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return done;
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}
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static int ublk_map_io(const struct ublk_queue *ubq, const struct request *req,
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struct ublk_io *io)
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{
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const unsigned int rq_bytes = blk_rq_bytes(req);
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/*
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* no zero copy, we delay copy WRITE request data into ublksrv
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* context and the big benefit is that pinning pages in current
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* context is pretty fast, see ublk_pin_user_pages
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*/
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if (req_op(req) != REQ_OP_WRITE && req_op(req) != REQ_OP_FLUSH)
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return rq_bytes;
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if (ublk_rq_has_data(req)) {
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struct ublk_map_data data = {
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.ubq = ubq,
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.rq = req,
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.io = io,
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.max_bytes = rq_bytes,
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};
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ublk_copy_user_pages(&data, true);
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return rq_bytes - data.max_bytes;
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}
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return rq_bytes;
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}
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static int ublk_unmap_io(const struct ublk_queue *ubq,
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const struct request *req,
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struct ublk_io *io)
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{
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const unsigned int rq_bytes = blk_rq_bytes(req);
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if (req_op(req) == REQ_OP_READ && ublk_rq_has_data(req)) {
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struct ublk_map_data data = {
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.ubq = ubq,
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.rq = req,
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.io = io,
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.max_bytes = io->res,
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};
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WARN_ON_ONCE(io->res > rq_bytes);
|
|
|
|
ublk_copy_user_pages(&data, false);
|
|
|
|
return io->res - data.max_bytes;
|
|
}
|
|
return rq_bytes;
|
|
}
|
|
|
|
static inline unsigned int ublk_req_build_flags(struct request *req)
|
|
{
|
|
unsigned flags = 0;
|
|
|
|
if (req->cmd_flags & REQ_FAILFAST_DEV)
|
|
flags |= UBLK_IO_F_FAILFAST_DEV;
|
|
|
|
if (req->cmd_flags & REQ_FAILFAST_TRANSPORT)
|
|
flags |= UBLK_IO_F_FAILFAST_TRANSPORT;
|
|
|
|
if (req->cmd_flags & REQ_FAILFAST_DRIVER)
|
|
flags |= UBLK_IO_F_FAILFAST_DRIVER;
|
|
|
|
if (req->cmd_flags & REQ_META)
|
|
flags |= UBLK_IO_F_META;
|
|
|
|
if (req->cmd_flags & REQ_FUA)
|
|
flags |= UBLK_IO_F_FUA;
|
|
|
|
if (req->cmd_flags & REQ_NOUNMAP)
|
|
flags |= UBLK_IO_F_NOUNMAP;
|
|
|
|
if (req->cmd_flags & REQ_SWAP)
|
|
flags |= UBLK_IO_F_SWAP;
|
|
|
|
return flags;
|
|
}
|
|
|
|
static blk_status_t ublk_setup_iod(struct ublk_queue *ubq, struct request *req)
|
|
{
|
|
struct ublksrv_io_desc *iod = ublk_get_iod(ubq, req->tag);
|
|
struct ublk_io *io = &ubq->ios[req->tag];
|
|
u32 ublk_op;
|
|
|
|
switch (req_op(req)) {
|
|
case REQ_OP_READ:
|
|
ublk_op = UBLK_IO_OP_READ;
|
|
break;
|
|
case REQ_OP_WRITE:
|
|
ublk_op = UBLK_IO_OP_WRITE;
|
|
break;
|
|
case REQ_OP_FLUSH:
|
|
ublk_op = UBLK_IO_OP_FLUSH;
|
|
break;
|
|
case REQ_OP_DISCARD:
|
|
ublk_op = UBLK_IO_OP_DISCARD;
|
|
break;
|
|
case REQ_OP_WRITE_ZEROES:
|
|
ublk_op = UBLK_IO_OP_WRITE_ZEROES;
|
|
break;
|
|
default:
|
|
return BLK_STS_IOERR;
|
|
}
|
|
|
|
/* need to translate since kernel may change */
|
|
iod->op_flags = ublk_op | ublk_req_build_flags(req);
|
|
iod->nr_sectors = blk_rq_sectors(req);
|
|
iod->start_sector = blk_rq_pos(req);
|
|
iod->addr = io->addr;
|
|
|
|
return BLK_STS_OK;
|
|
}
|
|
|
|
static inline struct ublk_uring_cmd_pdu *ublk_get_uring_cmd_pdu(
|
|
struct io_uring_cmd *ioucmd)
|
|
{
|
|
return (struct ublk_uring_cmd_pdu *)&ioucmd->pdu;
|
|
}
|
|
|
|
static inline bool ubq_daemon_is_dying(struct ublk_queue *ubq)
|
|
{
|
|
return ubq->ubq_daemon->flags & PF_EXITING;
|
|
}
|
|
|
|
/* todo: handle partial completion */
|
|
static void ublk_complete_rq(struct request *req)
|
|
{
|
|
struct ublk_queue *ubq = req->mq_hctx->driver_data;
|
|
struct ublk_io *io = &ubq->ios[req->tag];
|
|
unsigned int unmapped_bytes;
|
|
|
|
/* failed read IO if nothing is read */
|
|
if (!io->res && req_op(req) == REQ_OP_READ)
|
|
io->res = -EIO;
|
|
|
|
if (io->res < 0) {
|
|
blk_mq_end_request(req, errno_to_blk_status(io->res));
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* FLUSH or DISCARD usually won't return bytes returned, so end them
|
|
* directly.
|
|
*
|
|
* Both the two needn't unmap.
|
|
*/
|
|
if (req_op(req) != REQ_OP_READ && req_op(req) != REQ_OP_WRITE) {
|
|
blk_mq_end_request(req, BLK_STS_OK);
|
|
return;
|
|
}
|
|
|
|
/* for READ request, writing data in iod->addr to rq buffers */
|
|
unmapped_bytes = ublk_unmap_io(ubq, req, io);
|
|
|
|
/*
|
|
* Extremely impossible since we got data filled in just before
|
|
*
|
|
* Re-read simply for this unlikely case.
|
|
*/
|
|
if (unlikely(unmapped_bytes < io->res))
|
|
io->res = unmapped_bytes;
|
|
|
|
if (blk_update_request(req, BLK_STS_OK, io->res))
|
|
blk_mq_requeue_request(req, true);
|
|
else
|
|
__blk_mq_end_request(req, BLK_STS_OK);
|
|
}
|
|
|
|
/*
|
|
* Since __ublk_rq_task_work always fails requests immediately during
|
|
* exiting, __ublk_fail_req() is only called from abort context during
|
|
* exiting. So lock is unnecessary.
|
|
*
|
|
* Also aborting may not be started yet, keep in mind that one failed
|
|
* request may be issued by block layer again.
|
|
*/
|
|
static void __ublk_fail_req(struct ublk_io *io, struct request *req)
|
|
{
|
|
WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE);
|
|
|
|
if (!(io->flags & UBLK_IO_FLAG_ABORTED)) {
|
|
io->flags |= UBLK_IO_FLAG_ABORTED;
|
|
blk_mq_end_request(req, BLK_STS_IOERR);
|
|
}
|
|
}
|
|
|
|
static void ubq_complete_io_cmd(struct ublk_io *io, int res)
|
|
{
|
|
/* mark this cmd owned by ublksrv */
|
|
io->flags |= UBLK_IO_FLAG_OWNED_BY_SRV;
|
|
|
|
/*
|
|
* clear ACTIVE since we are done with this sqe/cmd slot
|
|
* We can only accept io cmd in case of being not active.
|
|
*/
|
|
io->flags &= ~UBLK_IO_FLAG_ACTIVE;
|
|
|
|
/* tell ublksrv one io request is coming */
|
|
io_uring_cmd_done(io->cmd, res, 0);
|
|
}
|
|
|
|
#define UBLK_REQUEUE_DELAY_MS 3
|
|
|
|
static inline void __ublk_rq_task_work(struct request *req)
|
|
{
|
|
struct ublk_queue *ubq = req->mq_hctx->driver_data;
|
|
struct ublk_device *ub = ubq->dev;
|
|
int tag = req->tag;
|
|
struct ublk_io *io = &ubq->ios[tag];
|
|
bool task_exiting = current != ubq->ubq_daemon || ubq_daemon_is_dying(ubq);
|
|
unsigned int mapped_bytes;
|
|
|
|
pr_devel("%s: complete: op %d, qid %d tag %d io_flags %x addr %llx\n",
|
|
__func__, io->cmd->cmd_op, ubq->q_id, req->tag, io->flags,
|
|
ublk_get_iod(ubq, req->tag)->addr);
|
|
|
|
if (unlikely(task_exiting)) {
|
|
blk_mq_end_request(req, BLK_STS_IOERR);
|
|
mod_delayed_work(system_wq, &ub->monitor_work, 0);
|
|
return;
|
|
}
|
|
|
|
if (ublk_need_get_data(ubq) &&
|
|
(req_op(req) == REQ_OP_WRITE ||
|
|
req_op(req) == REQ_OP_FLUSH)) {
|
|
/*
|
|
* We have not handled UBLK_IO_NEED_GET_DATA command yet,
|
|
* so immepdately pass UBLK_IO_RES_NEED_GET_DATA to ublksrv
|
|
* and notify it.
|
|
*/
|
|
if (!(io->flags & UBLK_IO_FLAG_NEED_GET_DATA)) {
|
|
io->flags |= UBLK_IO_FLAG_NEED_GET_DATA;
|
|
pr_devel("%s: need get data. op %d, qid %d tag %d io_flags %x\n",
|
|
__func__, io->cmd->cmd_op, ubq->q_id,
|
|
req->tag, io->flags);
|
|
ubq_complete_io_cmd(io, UBLK_IO_RES_NEED_GET_DATA);
|
|
return;
|
|
}
|
|
/*
|
|
* We have handled UBLK_IO_NEED_GET_DATA command,
|
|
* so clear UBLK_IO_FLAG_NEED_GET_DATA now and just
|
|
* do the copy work.
|
|
*/
|
|
io->flags &= ~UBLK_IO_FLAG_NEED_GET_DATA;
|
|
/* update iod->addr because ublksrv may have passed a new io buffer */
|
|
ublk_get_iod(ubq, req->tag)->addr = io->addr;
|
|
pr_devel("%s: update iod->addr: op %d, qid %d tag %d io_flags %x addr %llx\n",
|
|
__func__, io->cmd->cmd_op, ubq->q_id, req->tag, io->flags,
|
|
ublk_get_iod(ubq, req->tag)->addr);
|
|
}
|
|
|
|
mapped_bytes = ublk_map_io(ubq, req, io);
|
|
|
|
/* partially mapped, update io descriptor */
|
|
if (unlikely(mapped_bytes != blk_rq_bytes(req))) {
|
|
/*
|
|
* Nothing mapped, retry until we succeed.
|
|
*
|
|
* We may never succeed in mapping any bytes here because
|
|
* of OOM. TODO: reserve one buffer with single page pinned
|
|
* for providing forward progress guarantee.
|
|
*/
|
|
if (unlikely(!mapped_bytes)) {
|
|
blk_mq_requeue_request(req, false);
|
|
blk_mq_delay_kick_requeue_list(req->q,
|
|
UBLK_REQUEUE_DELAY_MS);
|
|
return;
|
|
}
|
|
|
|
ublk_get_iod(ubq, req->tag)->nr_sectors =
|
|
mapped_bytes >> 9;
|
|
}
|
|
|
|
ubq_complete_io_cmd(io, UBLK_IO_RES_OK);
|
|
}
|
|
|
|
static void ublk_rq_task_work_cb(struct io_uring_cmd *cmd)
|
|
{
|
|
struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd);
|
|
|
|
__ublk_rq_task_work(pdu->req);
|
|
}
|
|
|
|
static void ublk_rq_task_work_fn(struct callback_head *work)
|
|
{
|
|
struct ublk_rq_data *data = container_of(work,
|
|
struct ublk_rq_data, work);
|
|
struct request *req = blk_mq_rq_from_pdu(data);
|
|
|
|
__ublk_rq_task_work(req);
|
|
}
|
|
|
|
static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx,
|
|
const struct blk_mq_queue_data *bd)
|
|
{
|
|
struct ublk_queue *ubq = hctx->driver_data;
|
|
struct request *rq = bd->rq;
|
|
blk_status_t res;
|
|
|
|
/* fill iod to slot in io cmd buffer */
|
|
res = ublk_setup_iod(ubq, rq);
|
|
if (unlikely(res != BLK_STS_OK))
|
|
return BLK_STS_IOERR;
|
|
|
|
blk_mq_start_request(bd->rq);
|
|
|
|
if (unlikely(ubq_daemon_is_dying(ubq))) {
|
|
fail:
|
|
mod_delayed_work(system_wq, &ubq->dev->monitor_work, 0);
|
|
return BLK_STS_IOERR;
|
|
}
|
|
|
|
if (ublk_can_use_task_work(ubq)) {
|
|
struct ublk_rq_data *data = blk_mq_rq_to_pdu(rq);
|
|
enum task_work_notify_mode notify_mode = bd->last ?
|
|
TWA_SIGNAL_NO_IPI : TWA_NONE;
|
|
|
|
if (task_work_add(ubq->ubq_daemon, &data->work, notify_mode))
|
|
goto fail;
|
|
} else {
|
|
struct ublk_io *io = &ubq->ios[rq->tag];
|
|
struct io_uring_cmd *cmd = io->cmd;
|
|
struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd);
|
|
|
|
/*
|
|
* If the check pass, we know that this is a re-issued request aborted
|
|
* previously in monitor_work because the ubq_daemon(cmd's task) is
|
|
* PF_EXITING. We cannot call io_uring_cmd_complete_in_task() anymore
|
|
* because this ioucmd's io_uring context may be freed now if no inflight
|
|
* ioucmd exists. Otherwise we may cause null-deref in ctx->fallback_work.
|
|
*
|
|
* Note: monitor_work sets UBLK_IO_FLAG_ABORTED and ends this request(releasing
|
|
* the tag). Then the request is re-started(allocating the tag) and we are here.
|
|
* Since releasing/allocating a tag implies smp_mb(), finding UBLK_IO_FLAG_ABORTED
|
|
* guarantees that here is a re-issued request aborted previously.
|
|
*/
|
|
if ((io->flags & UBLK_IO_FLAG_ABORTED))
|
|
goto fail;
|
|
|
|
pdu->req = rq;
|
|
io_uring_cmd_complete_in_task(cmd, ublk_rq_task_work_cb);
|
|
}
|
|
|
|
return BLK_STS_OK;
|
|
}
|
|
|
|
static void ublk_commit_rqs(struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
struct ublk_queue *ubq = hctx->driver_data;
|
|
|
|
if (ublk_can_use_task_work(ubq))
|
|
__set_notify_signal(ubq->ubq_daemon);
|
|
}
|
|
|
|
static int ublk_init_hctx(struct blk_mq_hw_ctx *hctx, void *driver_data,
|
|
unsigned int hctx_idx)
|
|
{
|
|
struct ublk_device *ub = driver_data;
|
|
struct ublk_queue *ubq = ublk_get_queue(ub, hctx->queue_num);
|
|
|
|
hctx->driver_data = ubq;
|
|
return 0;
|
|
}
|
|
|
|
static int ublk_init_rq(struct blk_mq_tag_set *set, struct request *req,
|
|
unsigned int hctx_idx, unsigned int numa_node)
|
|
{
|
|
struct ublk_rq_data *data = blk_mq_rq_to_pdu(req);
|
|
|
|
init_task_work(&data->work, ublk_rq_task_work_fn);
|
|
return 0;
|
|
}
|
|
|
|
static const struct blk_mq_ops ublk_mq_ops = {
|
|
.queue_rq = ublk_queue_rq,
|
|
.commit_rqs = ublk_commit_rqs,
|
|
.init_hctx = ublk_init_hctx,
|
|
.init_request = ublk_init_rq,
|
|
};
|
|
|
|
static int ublk_ch_open(struct inode *inode, struct file *filp)
|
|
{
|
|
struct ublk_device *ub = container_of(inode->i_cdev,
|
|
struct ublk_device, cdev);
|
|
|
|
if (test_and_set_bit(UB_STATE_OPEN, &ub->state))
|
|
return -EBUSY;
|
|
filp->private_data = ub;
|
|
return 0;
|
|
}
|
|
|
|
static int ublk_ch_release(struct inode *inode, struct file *filp)
|
|
{
|
|
struct ublk_device *ub = filp->private_data;
|
|
|
|
clear_bit(UB_STATE_OPEN, &ub->state);
|
|
return 0;
|
|
}
|
|
|
|
/* map pre-allocated per-queue cmd buffer to ublksrv daemon */
|
|
static int ublk_ch_mmap(struct file *filp, struct vm_area_struct *vma)
|
|
{
|
|
struct ublk_device *ub = filp->private_data;
|
|
size_t sz = vma->vm_end - vma->vm_start;
|
|
unsigned max_sz = UBLK_MAX_QUEUE_DEPTH * sizeof(struct ublksrv_io_desc);
|
|
unsigned long pfn, end, phys_off = vma->vm_pgoff << PAGE_SHIFT;
|
|
int q_id, ret = 0;
|
|
|
|
spin_lock(&ub->mm_lock);
|
|
if (!ub->mm)
|
|
ub->mm = current->mm;
|
|
if (current->mm != ub->mm)
|
|
ret = -EINVAL;
|
|
spin_unlock(&ub->mm_lock);
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (vma->vm_flags & VM_WRITE)
|
|
return -EPERM;
|
|
|
|
end = UBLKSRV_CMD_BUF_OFFSET + ub->dev_info.nr_hw_queues * max_sz;
|
|
if (phys_off < UBLKSRV_CMD_BUF_OFFSET || phys_off >= end)
|
|
return -EINVAL;
|
|
|
|
q_id = (phys_off - UBLKSRV_CMD_BUF_OFFSET) / max_sz;
|
|
pr_devel("%s: qid %d, pid %d, addr %lx pg_off %lx sz %lu\n",
|
|
__func__, q_id, current->pid, vma->vm_start,
|
|
phys_off, (unsigned long)sz);
|
|
|
|
if (sz != ublk_queue_cmd_buf_size(ub, q_id))
|
|
return -EINVAL;
|
|
|
|
pfn = virt_to_phys(ublk_queue_cmd_buf(ub, q_id)) >> PAGE_SHIFT;
|
|
return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot);
|
|
}
|
|
|
|
static void ublk_commit_completion(struct ublk_device *ub,
|
|
struct ublksrv_io_cmd *ub_cmd)
|
|
{
|
|
u32 qid = ub_cmd->q_id, tag = ub_cmd->tag;
|
|
struct ublk_queue *ubq = ublk_get_queue(ub, qid);
|
|
struct ublk_io *io = &ubq->ios[tag];
|
|
struct request *req;
|
|
|
|
/* now this cmd slot is owned by nbd driver */
|
|
io->flags &= ~UBLK_IO_FLAG_OWNED_BY_SRV;
|
|
io->res = ub_cmd->result;
|
|
|
|
/* find the io request and complete */
|
|
req = blk_mq_tag_to_rq(ub->tag_set.tags[qid], tag);
|
|
|
|
if (req && likely(!blk_should_fake_timeout(req->q)))
|
|
ublk_complete_rq(req);
|
|
}
|
|
|
|
/*
|
|
* When ->ubq_daemon is exiting, either new request is ended immediately,
|
|
* or any queued io command is drained, so it is safe to abort queue
|
|
* lockless
|
|
*/
|
|
static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq)
|
|
{
|
|
int i;
|
|
|
|
if (!ublk_get_device(ub))
|
|
return;
|
|
|
|
for (i = 0; i < ubq->q_depth; i++) {
|
|
struct ublk_io *io = &ubq->ios[i];
|
|
|
|
if (!(io->flags & UBLK_IO_FLAG_ACTIVE)) {
|
|
struct request *rq;
|
|
|
|
/*
|
|
* Either we fail the request or ublk_rq_task_work_fn
|
|
* will do it
|
|
*/
|
|
rq = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], i);
|
|
if (rq)
|
|
__ublk_fail_req(io, rq);
|
|
}
|
|
}
|
|
ublk_put_device(ub);
|
|
}
|
|
|
|
static void ublk_daemon_monitor_work(struct work_struct *work)
|
|
{
|
|
struct ublk_device *ub =
|
|
container_of(work, struct ublk_device, monitor_work.work);
|
|
int i;
|
|
|
|
for (i = 0; i < ub->dev_info.nr_hw_queues; i++) {
|
|
struct ublk_queue *ubq = ublk_get_queue(ub, i);
|
|
|
|
if (ubq_daemon_is_dying(ubq)) {
|
|
schedule_work(&ub->stop_work);
|
|
|
|
/* abort queue is for making forward progress */
|
|
ublk_abort_queue(ub, ubq);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We can't schedule monitor work after ublk_remove() is started.
|
|
*
|
|
* No need ub->mutex, monitor work are canceled after state is marked
|
|
* as DEAD, so DEAD state is observed reliably.
|
|
*/
|
|
if (ub->dev_info.state != UBLK_S_DEV_DEAD)
|
|
schedule_delayed_work(&ub->monitor_work,
|
|
UBLK_DAEMON_MONITOR_PERIOD);
|
|
}
|
|
|
|
static inline bool ublk_queue_ready(struct ublk_queue *ubq)
|
|
{
|
|
return ubq->nr_io_ready == ubq->q_depth;
|
|
}
|
|
|
|
static void ublk_cancel_queue(struct ublk_queue *ubq)
|
|
{
|
|
int i;
|
|
|
|
if (!ublk_queue_ready(ubq))
|
|
return;
|
|
|
|
for (i = 0; i < ubq->q_depth; i++) {
|
|
struct ublk_io *io = &ubq->ios[i];
|
|
|
|
if (io->flags & UBLK_IO_FLAG_ACTIVE)
|
|
io_uring_cmd_done(io->cmd, UBLK_IO_RES_ABORT, 0);
|
|
}
|
|
|
|
/* all io commands are canceled */
|
|
ubq->nr_io_ready = 0;
|
|
}
|
|
|
|
/* Cancel all pending commands, must be called after del_gendisk() returns */
|
|
static void ublk_cancel_dev(struct ublk_device *ub)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < ub->dev_info.nr_hw_queues; i++)
|
|
ublk_cancel_queue(ublk_get_queue(ub, i));
|
|
}
|
|
|
|
static void ublk_stop_dev(struct ublk_device *ub)
|
|
{
|
|
mutex_lock(&ub->mutex);
|
|
if (ub->dev_info.state != UBLK_S_DEV_LIVE)
|
|
goto unlock;
|
|
|
|
del_gendisk(ub->ub_disk);
|
|
ub->dev_info.state = UBLK_S_DEV_DEAD;
|
|
ub->dev_info.ublksrv_pid = -1;
|
|
put_disk(ub->ub_disk);
|
|
ub->ub_disk = NULL;
|
|
unlock:
|
|
ublk_cancel_dev(ub);
|
|
mutex_unlock(&ub->mutex);
|
|
cancel_delayed_work_sync(&ub->monitor_work);
|
|
}
|
|
|
|
/* device can only be started after all IOs are ready */
|
|
static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq)
|
|
{
|
|
mutex_lock(&ub->mutex);
|
|
ubq->nr_io_ready++;
|
|
if (ublk_queue_ready(ubq)) {
|
|
ubq->ubq_daemon = current;
|
|
get_task_struct(ubq->ubq_daemon);
|
|
ub->nr_queues_ready++;
|
|
}
|
|
if (ub->nr_queues_ready == ub->dev_info.nr_hw_queues)
|
|
complete_all(&ub->completion);
|
|
mutex_unlock(&ub->mutex);
|
|
}
|
|
|
|
static void ublk_handle_need_get_data(struct ublk_device *ub, int q_id,
|
|
int tag, struct io_uring_cmd *cmd)
|
|
{
|
|
struct ublk_queue *ubq = ublk_get_queue(ub, q_id);
|
|
struct request *req = blk_mq_tag_to_rq(ub->tag_set.tags[q_id], tag);
|
|
|
|
if (ublk_can_use_task_work(ubq)) {
|
|
struct ublk_rq_data *data = blk_mq_rq_to_pdu(req);
|
|
|
|
/* should not fail since we call it just in ubq->ubq_daemon */
|
|
task_work_add(ubq->ubq_daemon, &data->work, TWA_SIGNAL_NO_IPI);
|
|
} else {
|
|
struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd);
|
|
|
|
pdu->req = req;
|
|
io_uring_cmd_complete_in_task(cmd, ublk_rq_task_work_cb);
|
|
}
|
|
}
|
|
|
|
static int ublk_ch_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
|
|
{
|
|
struct ublksrv_io_cmd *ub_cmd = (struct ublksrv_io_cmd *)cmd->cmd;
|
|
struct ublk_device *ub = cmd->file->private_data;
|
|
struct ublk_queue *ubq;
|
|
struct ublk_io *io;
|
|
u32 cmd_op = cmd->cmd_op;
|
|
unsigned tag = ub_cmd->tag;
|
|
int ret = -EINVAL;
|
|
|
|
pr_devel("%s: received: cmd op %d queue %d tag %d result %d\n",
|
|
__func__, cmd->cmd_op, ub_cmd->q_id, tag,
|
|
ub_cmd->result);
|
|
|
|
if (!(issue_flags & IO_URING_F_SQE128))
|
|
goto out;
|
|
|
|
if (ub_cmd->q_id >= ub->dev_info.nr_hw_queues)
|
|
goto out;
|
|
|
|
ubq = ublk_get_queue(ub, ub_cmd->q_id);
|
|
if (!ubq || ub_cmd->q_id != ubq->q_id)
|
|
goto out;
|
|
|
|
if (ubq->ubq_daemon && ubq->ubq_daemon != current)
|
|
goto out;
|
|
|
|
if (tag >= ubq->q_depth)
|
|
goto out;
|
|
|
|
io = &ubq->ios[tag];
|
|
|
|
/* there is pending io cmd, something must be wrong */
|
|
if (io->flags & UBLK_IO_FLAG_ACTIVE) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* ensure that the user issues UBLK_IO_NEED_GET_DATA
|
|
* iff the driver have set the UBLK_IO_FLAG_NEED_GET_DATA.
|
|
*/
|
|
if ((!!(io->flags & UBLK_IO_FLAG_NEED_GET_DATA))
|
|
^ (cmd_op == UBLK_IO_NEED_GET_DATA))
|
|
goto out;
|
|
|
|
switch (cmd_op) {
|
|
case UBLK_IO_FETCH_REQ:
|
|
/* UBLK_IO_FETCH_REQ is only allowed before queue is setup */
|
|
if (ublk_queue_ready(ubq)) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
/*
|
|
* The io is being handled by server, so COMMIT_RQ is expected
|
|
* instead of FETCH_REQ
|
|
*/
|
|
if (io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)
|
|
goto out;
|
|
/* FETCH_RQ has to provide IO buffer */
|
|
if (!ub_cmd->addr)
|
|
goto out;
|
|
io->cmd = cmd;
|
|
io->flags |= UBLK_IO_FLAG_ACTIVE;
|
|
io->addr = ub_cmd->addr;
|
|
|
|
ublk_mark_io_ready(ub, ubq);
|
|
break;
|
|
case UBLK_IO_COMMIT_AND_FETCH_REQ:
|
|
/* FETCH_RQ has to provide IO buffer */
|
|
if (!ub_cmd->addr)
|
|
goto out;
|
|
if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV))
|
|
goto out;
|
|
io->addr = ub_cmd->addr;
|
|
io->flags |= UBLK_IO_FLAG_ACTIVE;
|
|
io->cmd = cmd;
|
|
ublk_commit_completion(ub, ub_cmd);
|
|
break;
|
|
case UBLK_IO_NEED_GET_DATA:
|
|
if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV))
|
|
goto out;
|
|
io->addr = ub_cmd->addr;
|
|
io->cmd = cmd;
|
|
io->flags |= UBLK_IO_FLAG_ACTIVE;
|
|
ublk_handle_need_get_data(ub, ub_cmd->q_id, ub_cmd->tag, cmd);
|
|
break;
|
|
default:
|
|
goto out;
|
|
}
|
|
return -EIOCBQUEUED;
|
|
|
|
out:
|
|
io_uring_cmd_done(cmd, ret, 0);
|
|
pr_devel("%s: complete: cmd op %d, tag %d ret %x io_flags %x\n",
|
|
__func__, cmd_op, tag, ret, io->flags);
|
|
return -EIOCBQUEUED;
|
|
}
|
|
|
|
static const struct file_operations ublk_ch_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = ublk_ch_open,
|
|
.release = ublk_ch_release,
|
|
.llseek = no_llseek,
|
|
.uring_cmd = ublk_ch_uring_cmd,
|
|
.mmap = ublk_ch_mmap,
|
|
};
|
|
|
|
static void ublk_deinit_queue(struct ublk_device *ub, int q_id)
|
|
{
|
|
int size = ublk_queue_cmd_buf_size(ub, q_id);
|
|
struct ublk_queue *ubq = ublk_get_queue(ub, q_id);
|
|
|
|
if (ubq->ubq_daemon)
|
|
put_task_struct(ubq->ubq_daemon);
|
|
if (ubq->io_cmd_buf)
|
|
free_pages((unsigned long)ubq->io_cmd_buf, get_order(size));
|
|
}
|
|
|
|
static int ublk_init_queue(struct ublk_device *ub, int q_id)
|
|
{
|
|
struct ublk_queue *ubq = ublk_get_queue(ub, q_id);
|
|
gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO;
|
|
void *ptr;
|
|
int size;
|
|
|
|
ubq->flags = ub->dev_info.flags;
|
|
ubq->q_id = q_id;
|
|
ubq->q_depth = ub->dev_info.queue_depth;
|
|
size = ublk_queue_cmd_buf_size(ub, q_id);
|
|
|
|
ptr = (void *) __get_free_pages(gfp_flags, get_order(size));
|
|
if (!ptr)
|
|
return -ENOMEM;
|
|
|
|
ubq->io_cmd_buf = ptr;
|
|
ubq->dev = ub;
|
|
return 0;
|
|
}
|
|
|
|
static void ublk_deinit_queues(struct ublk_device *ub)
|
|
{
|
|
int nr_queues = ub->dev_info.nr_hw_queues;
|
|
int i;
|
|
|
|
if (!ub->__queues)
|
|
return;
|
|
|
|
for (i = 0; i < nr_queues; i++)
|
|
ublk_deinit_queue(ub, i);
|
|
kfree(ub->__queues);
|
|
}
|
|
|
|
static int ublk_init_queues(struct ublk_device *ub)
|
|
{
|
|
int nr_queues = ub->dev_info.nr_hw_queues;
|
|
int depth = ub->dev_info.queue_depth;
|
|
int ubq_size = sizeof(struct ublk_queue) + depth * sizeof(struct ublk_io);
|
|
int i, ret = -ENOMEM;
|
|
|
|
ub->queue_size = ubq_size;
|
|
ub->__queues = kcalloc(nr_queues, ubq_size, GFP_KERNEL);
|
|
if (!ub->__queues)
|
|
return ret;
|
|
|
|
for (i = 0; i < nr_queues; i++) {
|
|
if (ublk_init_queue(ub, i))
|
|
goto fail;
|
|
}
|
|
|
|
init_completion(&ub->completion);
|
|
return 0;
|
|
|
|
fail:
|
|
ublk_deinit_queues(ub);
|
|
return ret;
|
|
}
|
|
|
|
static int ublk_alloc_dev_number(struct ublk_device *ub, int idx)
|
|
{
|
|
int i = idx;
|
|
int err;
|
|
|
|
spin_lock(&ublk_idr_lock);
|
|
/* allocate id, if @id >= 0, we're requesting that specific id */
|
|
if (i >= 0) {
|
|
err = idr_alloc(&ublk_index_idr, ub, i, i + 1, GFP_NOWAIT);
|
|
if (err == -ENOSPC)
|
|
err = -EEXIST;
|
|
} else {
|
|
err = idr_alloc(&ublk_index_idr, ub, 0, 0, GFP_NOWAIT);
|
|
}
|
|
spin_unlock(&ublk_idr_lock);
|
|
|
|
if (err >= 0)
|
|
ub->ub_number = err;
|
|
|
|
return err;
|
|
}
|
|
|
|
static void ublk_free_dev_number(struct ublk_device *ub)
|
|
{
|
|
spin_lock(&ublk_idr_lock);
|
|
idr_remove(&ublk_index_idr, ub->ub_number);
|
|
wake_up_all(&ublk_idr_wq);
|
|
spin_unlock(&ublk_idr_lock);
|
|
}
|
|
|
|
static void ublk_cdev_rel(struct device *dev)
|
|
{
|
|
struct ublk_device *ub = container_of(dev, struct ublk_device, cdev_dev);
|
|
|
|
blk_mq_free_tag_set(&ub->tag_set);
|
|
ublk_deinit_queues(ub);
|
|
ublk_free_dev_number(ub);
|
|
mutex_destroy(&ub->mutex);
|
|
kfree(ub);
|
|
}
|
|
|
|
static int ublk_add_chdev(struct ublk_device *ub)
|
|
{
|
|
struct device *dev = &ub->cdev_dev;
|
|
int minor = ub->ub_number;
|
|
int ret;
|
|
|
|
dev->parent = ublk_misc.this_device;
|
|
dev->devt = MKDEV(MAJOR(ublk_chr_devt), minor);
|
|
dev->class = ublk_chr_class;
|
|
dev->release = ublk_cdev_rel;
|
|
device_initialize(dev);
|
|
|
|
ret = dev_set_name(dev, "ublkc%d", minor);
|
|
if (ret)
|
|
goto fail;
|
|
|
|
cdev_init(&ub->cdev, &ublk_ch_fops);
|
|
ret = cdev_device_add(&ub->cdev, dev);
|
|
if (ret)
|
|
goto fail;
|
|
return 0;
|
|
fail:
|
|
put_device(dev);
|
|
return ret;
|
|
}
|
|
|
|
static void ublk_stop_work_fn(struct work_struct *work)
|
|
{
|
|
struct ublk_device *ub =
|
|
container_of(work, struct ublk_device, stop_work);
|
|
|
|
ublk_stop_dev(ub);
|
|
}
|
|
|
|
/* align max io buffer size with PAGE_SIZE */
|
|
static void ublk_align_max_io_size(struct ublk_device *ub)
|
|
{
|
|
unsigned int max_io_bytes = ub->dev_info.max_io_buf_bytes;
|
|
|
|
ub->dev_info.max_io_buf_bytes =
|
|
round_down(max_io_bytes, PAGE_SIZE);
|
|
}
|
|
|
|
static int ublk_add_tag_set(struct ublk_device *ub)
|
|
{
|
|
ub->tag_set.ops = &ublk_mq_ops;
|
|
ub->tag_set.nr_hw_queues = ub->dev_info.nr_hw_queues;
|
|
ub->tag_set.queue_depth = ub->dev_info.queue_depth;
|
|
ub->tag_set.numa_node = NUMA_NO_NODE;
|
|
ub->tag_set.cmd_size = sizeof(struct ublk_rq_data);
|
|
ub->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
|
|
ub->tag_set.driver_data = ub;
|
|
return blk_mq_alloc_tag_set(&ub->tag_set);
|
|
}
|
|
|
|
static void ublk_remove(struct ublk_device *ub)
|
|
{
|
|
ublk_stop_dev(ub);
|
|
cancel_work_sync(&ub->stop_work);
|
|
cdev_device_del(&ub->cdev, &ub->cdev_dev);
|
|
put_device(&ub->cdev_dev);
|
|
}
|
|
|
|
static struct ublk_device *ublk_get_device_from_id(int idx)
|
|
{
|
|
struct ublk_device *ub = NULL;
|
|
|
|
if (idx < 0)
|
|
return NULL;
|
|
|
|
spin_lock(&ublk_idr_lock);
|
|
ub = idr_find(&ublk_index_idr, idx);
|
|
if (ub)
|
|
ub = ublk_get_device(ub);
|
|
spin_unlock(&ublk_idr_lock);
|
|
|
|
return ub;
|
|
}
|
|
|
|
static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
|
|
{
|
|
struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
|
|
int ublksrv_pid = (int)header->data[0];
|
|
struct ublk_device *ub;
|
|
struct gendisk *disk;
|
|
int ret = -EINVAL;
|
|
|
|
if (ublksrv_pid <= 0)
|
|
return -EINVAL;
|
|
|
|
ub = ublk_get_device_from_id(header->dev_id);
|
|
if (!ub)
|
|
return -EINVAL;
|
|
|
|
wait_for_completion_interruptible(&ub->completion);
|
|
|
|
schedule_delayed_work(&ub->monitor_work, UBLK_DAEMON_MONITOR_PERIOD);
|
|
|
|
mutex_lock(&ub->mutex);
|
|
if (ub->dev_info.state == UBLK_S_DEV_LIVE ||
|
|
test_bit(UB_STATE_USED, &ub->state)) {
|
|
ret = -EEXIST;
|
|
goto out_unlock;
|
|
}
|
|
|
|
disk = blk_mq_alloc_disk(&ub->tag_set, ub);
|
|
if (IS_ERR(disk)) {
|
|
ret = PTR_ERR(disk);
|
|
goto out_unlock;
|
|
}
|
|
sprintf(disk->disk_name, "ublkb%d", ub->ub_number);
|
|
disk->fops = &ub_fops;
|
|
disk->private_data = ub;
|
|
|
|
ub->dev_info.ublksrv_pid = ublksrv_pid;
|
|
ub->ub_disk = disk;
|
|
|
|
ret = ublk_apply_params(ub);
|
|
if (ret)
|
|
goto out_put_disk;
|
|
|
|
get_device(&ub->cdev_dev);
|
|
ret = add_disk(disk);
|
|
if (ret) {
|
|
/*
|
|
* Has to drop the reference since ->free_disk won't be
|
|
* called in case of add_disk failure.
|
|
*/
|
|
ublk_put_device(ub);
|
|
goto out_put_disk;
|
|
}
|
|
set_bit(UB_STATE_USED, &ub->state);
|
|
ub->dev_info.state = UBLK_S_DEV_LIVE;
|
|
out_put_disk:
|
|
if (ret)
|
|
put_disk(disk);
|
|
out_unlock:
|
|
mutex_unlock(&ub->mutex);
|
|
ublk_put_device(ub);
|
|
return ret;
|
|
}
|
|
|
|
static int ublk_ctrl_get_queue_affinity(struct io_uring_cmd *cmd)
|
|
{
|
|
struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
|
|
void __user *argp = (void __user *)(unsigned long)header->addr;
|
|
struct ublk_device *ub;
|
|
cpumask_var_t cpumask;
|
|
unsigned long queue;
|
|
unsigned int retlen;
|
|
unsigned int i;
|
|
int ret = -EINVAL;
|
|
|
|
if (header->len * BITS_PER_BYTE < nr_cpu_ids)
|
|
return -EINVAL;
|
|
if (header->len & (sizeof(unsigned long)-1))
|
|
return -EINVAL;
|
|
if (!header->addr)
|
|
return -EINVAL;
|
|
|
|
ub = ublk_get_device_from_id(header->dev_id);
|
|
if (!ub)
|
|
return -EINVAL;
|
|
|
|
queue = header->data[0];
|
|
if (queue >= ub->dev_info.nr_hw_queues)
|
|
goto out_put_device;
|
|
|
|
ret = -ENOMEM;
|
|
if (!zalloc_cpumask_var(&cpumask, GFP_KERNEL))
|
|
goto out_put_device;
|
|
|
|
for_each_possible_cpu(i) {
|
|
if (ub->tag_set.map[HCTX_TYPE_DEFAULT].mq_map[i] == queue)
|
|
cpumask_set_cpu(i, cpumask);
|
|
}
|
|
|
|
ret = -EFAULT;
|
|
retlen = min_t(unsigned short, header->len, cpumask_size());
|
|
if (copy_to_user(argp, cpumask, retlen))
|
|
goto out_free_cpumask;
|
|
if (retlen != header->len &&
|
|
clear_user(argp + retlen, header->len - retlen))
|
|
goto out_free_cpumask;
|
|
|
|
ret = 0;
|
|
out_free_cpumask:
|
|
free_cpumask_var(cpumask);
|
|
out_put_device:
|
|
ublk_put_device(ub);
|
|
return ret;
|
|
}
|
|
|
|
static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info *info)
|
|
{
|
|
pr_devel("%s: dev id %d flags %llx\n", __func__,
|
|
info->dev_id, info->flags);
|
|
pr_devel("\t nr_hw_queues %d queue_depth %d\n",
|
|
info->nr_hw_queues, info->queue_depth);
|
|
}
|
|
|
|
static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd)
|
|
{
|
|
struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
|
|
void __user *argp = (void __user *)(unsigned long)header->addr;
|
|
struct ublksrv_ctrl_dev_info info;
|
|
struct ublk_device *ub;
|
|
int ret = -EINVAL;
|
|
|
|
if (header->len < sizeof(info) || !header->addr)
|
|
return -EINVAL;
|
|
if (header->queue_id != (u16)-1) {
|
|
pr_warn("%s: queue_id is wrong %x\n",
|
|
__func__, header->queue_id);
|
|
return -EINVAL;
|
|
}
|
|
if (copy_from_user(&info, argp, sizeof(info)))
|
|
return -EFAULT;
|
|
ublk_dump_dev_info(&info);
|
|
if (header->dev_id != info.dev_id) {
|
|
pr_warn("%s: dev id not match %u %u\n",
|
|
__func__, header->dev_id, info.dev_id);
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = mutex_lock_killable(&ublk_ctl_mutex);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = -ENOMEM;
|
|
ub = kzalloc(sizeof(*ub), GFP_KERNEL);
|
|
if (!ub)
|
|
goto out_unlock;
|
|
mutex_init(&ub->mutex);
|
|
spin_lock_init(&ub->mm_lock);
|
|
INIT_WORK(&ub->stop_work, ublk_stop_work_fn);
|
|
INIT_DELAYED_WORK(&ub->monitor_work, ublk_daemon_monitor_work);
|
|
|
|
ret = ublk_alloc_dev_number(ub, header->dev_id);
|
|
if (ret < 0)
|
|
goto out_free_ub;
|
|
|
|
memcpy(&ub->dev_info, &info, sizeof(info));
|
|
|
|
/* update device id */
|
|
ub->dev_info.dev_id = ub->ub_number;
|
|
|
|
/*
|
|
* 64bit flags will be copied back to userspace as feature
|
|
* negotiation result, so have to clear flags which driver
|
|
* doesn't support yet, then userspace can get correct flags
|
|
* (features) to handle.
|
|
*/
|
|
ub->dev_info.flags &= UBLK_F_ALL;
|
|
|
|
/* We are not ready to support zero copy */
|
|
ub->dev_info.flags &= ~UBLK_F_SUPPORT_ZERO_COPY;
|
|
|
|
ub->dev_info.nr_hw_queues = min_t(unsigned int,
|
|
ub->dev_info.nr_hw_queues, nr_cpu_ids);
|
|
ublk_align_max_io_size(ub);
|
|
|
|
ret = ublk_init_queues(ub);
|
|
if (ret)
|
|
goto out_free_dev_number;
|
|
|
|
ret = ublk_add_tag_set(ub);
|
|
if (ret)
|
|
goto out_deinit_queues;
|
|
|
|
ret = -EFAULT;
|
|
if (copy_to_user(argp, &ub->dev_info, sizeof(info)))
|
|
goto out_free_tag_set;
|
|
|
|
/*
|
|
* Add the char dev so that ublksrv daemon can be setup.
|
|
* ublk_add_chdev() will cleanup everything if it fails.
|
|
*/
|
|
ret = ublk_add_chdev(ub);
|
|
goto out_unlock;
|
|
|
|
out_free_tag_set:
|
|
blk_mq_free_tag_set(&ub->tag_set);
|
|
out_deinit_queues:
|
|
ublk_deinit_queues(ub);
|
|
out_free_dev_number:
|
|
ublk_free_dev_number(ub);
|
|
out_free_ub:
|
|
mutex_destroy(&ub->mutex);
|
|
kfree(ub);
|
|
out_unlock:
|
|
mutex_unlock(&ublk_ctl_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static inline bool ublk_idr_freed(int id)
|
|
{
|
|
void *ptr;
|
|
|
|
spin_lock(&ublk_idr_lock);
|
|
ptr = idr_find(&ublk_index_idr, id);
|
|
spin_unlock(&ublk_idr_lock);
|
|
|
|
return ptr == NULL;
|
|
}
|
|
|
|
static int ublk_ctrl_del_dev(int idx)
|
|
{
|
|
struct ublk_device *ub;
|
|
int ret;
|
|
|
|
ret = mutex_lock_killable(&ublk_ctl_mutex);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ub = ublk_get_device_from_id(idx);
|
|
if (ub) {
|
|
ublk_remove(ub);
|
|
ublk_put_device(ub);
|
|
ret = 0;
|
|
} else {
|
|
ret = -ENODEV;
|
|
}
|
|
|
|
/*
|
|
* Wait until the idr is removed, then it can be reused after
|
|
* DEL_DEV command is returned.
|
|
*/
|
|
if (!ret)
|
|
wait_event(ublk_idr_wq, ublk_idr_freed(idx));
|
|
mutex_unlock(&ublk_ctl_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd *cmd)
|
|
{
|
|
struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
|
|
|
|
pr_devel("%s: cmd_op %x, dev id %d qid %d data %llx buf %llx len %u\n",
|
|
__func__, cmd->cmd_op, header->dev_id, header->queue_id,
|
|
header->data[0], header->addr, header->len);
|
|
}
|
|
|
|
static int ublk_ctrl_stop_dev(struct io_uring_cmd *cmd)
|
|
{
|
|
struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
|
|
struct ublk_device *ub;
|
|
|
|
ub = ublk_get_device_from_id(header->dev_id);
|
|
if (!ub)
|
|
return -EINVAL;
|
|
|
|
ublk_stop_dev(ub);
|
|
cancel_work_sync(&ub->stop_work);
|
|
|
|
ublk_put_device(ub);
|
|
return 0;
|
|
}
|
|
|
|
static int ublk_ctrl_get_dev_info(struct io_uring_cmd *cmd)
|
|
{
|
|
struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
|
|
void __user *argp = (void __user *)(unsigned long)header->addr;
|
|
struct ublk_device *ub;
|
|
int ret = 0;
|
|
|
|
if (header->len < sizeof(struct ublksrv_ctrl_dev_info) || !header->addr)
|
|
return -EINVAL;
|
|
|
|
ub = ublk_get_device_from_id(header->dev_id);
|
|
if (!ub)
|
|
return -EINVAL;
|
|
|
|
if (copy_to_user(argp, &ub->dev_info, sizeof(ub->dev_info)))
|
|
ret = -EFAULT;
|
|
ublk_put_device(ub);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int ublk_ctrl_get_params(struct io_uring_cmd *cmd)
|
|
{
|
|
struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
|
|
void __user *argp = (void __user *)(unsigned long)header->addr;
|
|
struct ublk_params_header ph;
|
|
struct ublk_device *ub;
|
|
int ret;
|
|
|
|
if (header->len <= sizeof(ph) || !header->addr)
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&ph, argp, sizeof(ph)))
|
|
return -EFAULT;
|
|
|
|
if (ph.len > header->len || !ph.len)
|
|
return -EINVAL;
|
|
|
|
if (ph.len > sizeof(struct ublk_params))
|
|
ph.len = sizeof(struct ublk_params);
|
|
|
|
ub = ublk_get_device_from_id(header->dev_id);
|
|
if (!ub)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&ub->mutex);
|
|
if (copy_to_user(argp, &ub->params, ph.len))
|
|
ret = -EFAULT;
|
|
else
|
|
ret = 0;
|
|
mutex_unlock(&ub->mutex);
|
|
|
|
ublk_put_device(ub);
|
|
return ret;
|
|
}
|
|
|
|
static int ublk_ctrl_set_params(struct io_uring_cmd *cmd)
|
|
{
|
|
struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
|
|
void __user *argp = (void __user *)(unsigned long)header->addr;
|
|
struct ublk_params_header ph;
|
|
struct ublk_device *ub;
|
|
int ret = -EFAULT;
|
|
|
|
if (header->len <= sizeof(ph) || !header->addr)
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&ph, argp, sizeof(ph)))
|
|
return -EFAULT;
|
|
|
|
if (ph.len > header->len || !ph.len || !ph.types)
|
|
return -EINVAL;
|
|
|
|
if (ph.len > sizeof(struct ublk_params))
|
|
ph.len = sizeof(struct ublk_params);
|
|
|
|
ub = ublk_get_device_from_id(header->dev_id);
|
|
if (!ub)
|
|
return -EINVAL;
|
|
|
|
/* parameters can only be changed when device isn't live */
|
|
mutex_lock(&ub->mutex);
|
|
if (ub->dev_info.state == UBLK_S_DEV_LIVE) {
|
|
ret = -EACCES;
|
|
} else if (copy_from_user(&ub->params, argp, ph.len)) {
|
|
ret = -EFAULT;
|
|
} else {
|
|
/* clear all we don't support yet */
|
|
ub->params.types &= UBLK_PARAM_TYPE_ALL;
|
|
ret = ublk_validate_params(ub);
|
|
}
|
|
mutex_unlock(&ub->mutex);
|
|
ublk_put_device(ub);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd,
|
|
unsigned int issue_flags)
|
|
{
|
|
struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
|
|
int ret = -EINVAL;
|
|
|
|
ublk_ctrl_cmd_dump(cmd);
|
|
|
|
if (!(issue_flags & IO_URING_F_SQE128))
|
|
goto out;
|
|
|
|
ret = -EPERM;
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
goto out;
|
|
|
|
ret = -ENODEV;
|
|
switch (cmd->cmd_op) {
|
|
case UBLK_CMD_START_DEV:
|
|
ret = ublk_ctrl_start_dev(cmd);
|
|
break;
|
|
case UBLK_CMD_STOP_DEV:
|
|
ret = ublk_ctrl_stop_dev(cmd);
|
|
break;
|
|
case UBLK_CMD_GET_DEV_INFO:
|
|
ret = ublk_ctrl_get_dev_info(cmd);
|
|
break;
|
|
case UBLK_CMD_ADD_DEV:
|
|
ret = ublk_ctrl_add_dev(cmd);
|
|
break;
|
|
case UBLK_CMD_DEL_DEV:
|
|
ret = ublk_ctrl_del_dev(header->dev_id);
|
|
break;
|
|
case UBLK_CMD_GET_QUEUE_AFFINITY:
|
|
ret = ublk_ctrl_get_queue_affinity(cmd);
|
|
break;
|
|
case UBLK_CMD_GET_PARAMS:
|
|
ret = ublk_ctrl_get_params(cmd);
|
|
break;
|
|
case UBLK_CMD_SET_PARAMS:
|
|
ret = ublk_ctrl_set_params(cmd);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
out:
|
|
io_uring_cmd_done(cmd, ret, 0);
|
|
pr_devel("%s: cmd done ret %d cmd_op %x, dev id %d qid %d\n",
|
|
__func__, ret, cmd->cmd_op, header->dev_id, header->queue_id);
|
|
return -EIOCBQUEUED;
|
|
}
|
|
|
|
static const struct file_operations ublk_ctl_fops = {
|
|
.open = nonseekable_open,
|
|
.uring_cmd = ublk_ctrl_uring_cmd,
|
|
.owner = THIS_MODULE,
|
|
.llseek = noop_llseek,
|
|
};
|
|
|
|
static struct miscdevice ublk_misc = {
|
|
.minor = MISC_DYNAMIC_MINOR,
|
|
.name = "ublk-control",
|
|
.fops = &ublk_ctl_fops,
|
|
};
|
|
|
|
static int __init ublk_init(void)
|
|
{
|
|
int ret;
|
|
|
|
init_waitqueue_head(&ublk_idr_wq);
|
|
|
|
ret = misc_register(&ublk_misc);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = alloc_chrdev_region(&ublk_chr_devt, 0, UBLK_MINORS, "ublk-char");
|
|
if (ret)
|
|
goto unregister_mis;
|
|
|
|
ublk_chr_class = class_create(THIS_MODULE, "ublk-char");
|
|
if (IS_ERR(ublk_chr_class)) {
|
|
ret = PTR_ERR(ublk_chr_class);
|
|
goto free_chrdev_region;
|
|
}
|
|
return 0;
|
|
|
|
free_chrdev_region:
|
|
unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS);
|
|
unregister_mis:
|
|
misc_deregister(&ublk_misc);
|
|
return ret;
|
|
}
|
|
|
|
static void __exit ublk_exit(void)
|
|
{
|
|
struct ublk_device *ub;
|
|
int id;
|
|
|
|
class_destroy(ublk_chr_class);
|
|
|
|
misc_deregister(&ublk_misc);
|
|
|
|
idr_for_each_entry(&ublk_index_idr, ub, id)
|
|
ublk_remove(ub);
|
|
|
|
idr_destroy(&ublk_index_idr);
|
|
unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS);
|
|
}
|
|
|
|
module_init(ublk_init);
|
|
module_exit(ublk_exit);
|
|
|
|
MODULE_AUTHOR("Ming Lei <ming.lei@redhat.com>");
|
|
MODULE_LICENSE("GPL");
|