1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Userspace block device - block device which IO is handled from userspace
5 * Take full use of io_uring passthrough command for communicating with
6 * ublk userspace daemon(ublksrvd) for handling basic IO request.
8 * Copyright 2022 Ming Lei <ming.lei@redhat.com>
10 * (part of code stolen from loop.c)
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/sched.h>
16 #include <linux/pagemap.h>
17 #include <linux/file.h>
18 #include <linux/stat.h>
19 #include <linux/errno.h>
20 #include <linux/major.h>
21 #include <linux/wait.h>
22 #include <linux/blkdev.h>
23 #include <linux/init.h>
24 #include <linux/swap.h>
25 #include <linux/slab.h>
26 #include <linux/compat.h>
27 #include <linux/mutex.h>
28 #include <linux/writeback.h>
29 #include <linux/completion.h>
30 #include <linux/highmem.h>
31 #include <linux/sysfs.h>
32 #include <linux/miscdevice.h>
33 #include <linux/falloc.h>
34 #include <linux/uio.h>
35 #include <linux/ioprio.h>
36 #include <linux/sched/mm.h>
37 #include <linux/uaccess.h>
38 #include <linux/cdev.h>
39 #include <linux/io_uring.h>
40 #include <linux/blk-mq.h>
41 #include <linux/delay.h>
44 #include <linux/task_work.h>
45 #include <linux/namei.h>
46 #include <uapi/linux/ublk_cmd.h>
48 #define UBLK_MINORS (1U << MINORBITS)
50 /* All UBLK_F_* have to be included into UBLK_F_ALL */
51 #define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY \
52 | UBLK_F_URING_CMD_COMP_IN_TASK \
53 | UBLK_F_NEED_GET_DATA \
54 | UBLK_F_USER_RECOVERY \
55 | UBLK_F_USER_RECOVERY_REISSUE \
56 | UBLK_F_UNPRIVILEGED_DEV \
57 | UBLK_F_CMD_IOCTL_ENCODE)
59 /* All UBLK_PARAM_TYPE_* should be included here */
60 #define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | \
61 UBLK_PARAM_TYPE_DISCARD | UBLK_PARAM_TYPE_DEVT)
64 struct llist_node node
;
65 struct callback_head work
;
68 struct ublk_uring_cmd_pdu
{
69 struct ublk_queue
*ubq
;
73 * io command is active: sqe cmd is received, and its cqe isn't done
75 * If the flag is set, the io command is owned by ublk driver, and waited
76 * for incoming blk-mq request from the ublk block device.
78 * If the flag is cleared, the io command will be completed, and owned by
81 #define UBLK_IO_FLAG_ACTIVE 0x01
84 * IO command is completed via cqe, and it is being handled by ublksrv, and
87 * Basically exclusively with UBLK_IO_FLAG_ACTIVE, so can be served for
90 #define UBLK_IO_FLAG_OWNED_BY_SRV 0x02
93 * IO command is aborted, so this flag is set in case of
94 * !UBLK_IO_FLAG_ACTIVE.
96 * After this flag is observed, any pending or new incoming request
97 * associated with this io command will be failed immediately
99 #define UBLK_IO_FLAG_ABORTED 0x04
102 * UBLK_IO_FLAG_NEED_GET_DATA is set because IO command requires
103 * get data buffer address from ublksrv.
105 * Then, bio data could be copied into this data buffer for a WRITE request
106 * after the IO command is issued again and UBLK_IO_FLAG_NEED_GET_DATA is unset.
108 #define UBLK_IO_FLAG_NEED_GET_DATA 0x08
111 /* userspace buffer address from io cmd */
116 struct io_uring_cmd
*cmd
;
124 struct task_struct
*ubq_daemon
;
127 struct llist_head io_cmds
;
129 unsigned long io_addr
; /* mapped vm address */
130 unsigned int max_io_sz
;
132 unsigned short nr_io_ready
; /* how many ios setup */
133 struct ublk_device
*dev
;
134 struct ublk_io ios
[];
137 #define UBLK_DAEMON_MONITOR_PERIOD (5 * HZ)
140 struct gendisk
*ub_disk
;
144 unsigned int queue_size
;
145 struct ublksrv_ctrl_dev_info dev_info
;
147 struct blk_mq_tag_set tag_set
;
150 struct device cdev_dev
;
152 #define UB_STATE_OPEN 0
153 #define UB_STATE_USED 1
154 #define UB_STATE_DELETED 2
161 struct mm_struct
*mm
;
163 struct ublk_params params
;
165 struct completion completion
;
166 unsigned int nr_queues_ready
;
167 unsigned int nr_privileged_daemon
;
170 * Our ubq->daemon may be killed without any notification, so
171 * monitor each queue's daemon periodically
173 struct delayed_work monitor_work
;
174 struct work_struct quiesce_work
;
175 struct work_struct stop_work
;
178 /* header of ublk_params */
179 struct ublk_params_header
{
184 static dev_t ublk_chr_devt
;
185 static struct class *ublk_chr_class
;
187 static DEFINE_IDR(ublk_index_idr
);
188 static DEFINE_SPINLOCK(ublk_idr_lock
);
189 static wait_queue_head_t ublk_idr_wq
; /* wait until one idr is freed */
191 static DEFINE_MUTEX(ublk_ctl_mutex
);
194 * Max ublk devices allowed to add
196 * It can be extended to one per-user limit in future or even controlled
199 static unsigned int ublks_max
= 64;
200 static unsigned int ublks_added
; /* protected by ublk_ctl_mutex */
202 static struct miscdevice ublk_misc
;
204 static void ublk_dev_param_basic_apply(struct ublk_device
*ub
)
206 struct request_queue
*q
= ub
->ub_disk
->queue
;
207 const struct ublk_param_basic
*p
= &ub
->params
.basic
;
209 blk_queue_logical_block_size(q
, 1 << p
->logical_bs_shift
);
210 blk_queue_physical_block_size(q
, 1 << p
->physical_bs_shift
);
211 blk_queue_io_min(q
, 1 << p
->io_min_shift
);
212 blk_queue_io_opt(q
, 1 << p
->io_opt_shift
);
214 blk_queue_write_cache(q
, p
->attrs
& UBLK_ATTR_VOLATILE_CACHE
,
215 p
->attrs
& UBLK_ATTR_FUA
);
216 if (p
->attrs
& UBLK_ATTR_ROTATIONAL
)
217 blk_queue_flag_clear(QUEUE_FLAG_NONROT
, q
);
219 blk_queue_flag_set(QUEUE_FLAG_NONROT
, q
);
221 blk_queue_max_hw_sectors(q
, p
->max_sectors
);
222 blk_queue_chunk_sectors(q
, p
->chunk_sectors
);
223 blk_queue_virt_boundary(q
, p
->virt_boundary_mask
);
225 if (p
->attrs
& UBLK_ATTR_READ_ONLY
)
226 set_disk_ro(ub
->ub_disk
, true);
228 set_capacity(ub
->ub_disk
, p
->dev_sectors
);
231 static void ublk_dev_param_discard_apply(struct ublk_device
*ub
)
233 struct request_queue
*q
= ub
->ub_disk
->queue
;
234 const struct ublk_param_discard
*p
= &ub
->params
.discard
;
236 q
->limits
.discard_alignment
= p
->discard_alignment
;
237 q
->limits
.discard_granularity
= p
->discard_granularity
;
238 blk_queue_max_discard_sectors(q
, p
->max_discard_sectors
);
239 blk_queue_max_write_zeroes_sectors(q
,
240 p
->max_write_zeroes_sectors
);
241 blk_queue_max_discard_segments(q
, p
->max_discard_segments
);
244 static int ublk_validate_params(const struct ublk_device
*ub
)
246 /* basic param is the only one which must be set */
247 if (ub
->params
.types
& UBLK_PARAM_TYPE_BASIC
) {
248 const struct ublk_param_basic
*p
= &ub
->params
.basic
;
250 if (p
->logical_bs_shift
> PAGE_SHIFT
)
253 if (p
->logical_bs_shift
> p
->physical_bs_shift
)
256 if (p
->max_sectors
> (ub
->dev_info
.max_io_buf_bytes
>> 9))
261 if (ub
->params
.types
& UBLK_PARAM_TYPE_DISCARD
) {
262 const struct ublk_param_discard
*p
= &ub
->params
.discard
;
264 /* So far, only support single segment discard */
265 if (p
->max_discard_sectors
&& p
->max_discard_segments
!= 1)
268 if (!p
->discard_granularity
)
272 /* dev_t is read-only */
273 if (ub
->params
.types
& UBLK_PARAM_TYPE_DEVT
)
279 static int ublk_apply_params(struct ublk_device
*ub
)
281 if (!(ub
->params
.types
& UBLK_PARAM_TYPE_BASIC
))
284 ublk_dev_param_basic_apply(ub
);
286 if (ub
->params
.types
& UBLK_PARAM_TYPE_DISCARD
)
287 ublk_dev_param_discard_apply(ub
);
292 static inline bool ublk_can_use_task_work(const struct ublk_queue
*ubq
)
294 if (IS_BUILTIN(CONFIG_BLK_DEV_UBLK
) &&
295 !(ubq
->flags
& UBLK_F_URING_CMD_COMP_IN_TASK
))
300 static inline bool ublk_need_get_data(const struct ublk_queue
*ubq
)
302 return ubq
->flags
& UBLK_F_NEED_GET_DATA
;
305 static struct ublk_device
*ublk_get_device(struct ublk_device
*ub
)
307 if (kobject_get_unless_zero(&ub
->cdev_dev
.kobj
))
312 static void ublk_put_device(struct ublk_device
*ub
)
314 put_device(&ub
->cdev_dev
);
317 static inline struct ublk_queue
*ublk_get_queue(struct ublk_device
*dev
,
320 return (struct ublk_queue
*)&(dev
->__queues
[qid
* dev
->queue_size
]);
323 static inline bool ublk_rq_has_data(const struct request
*rq
)
325 return bio_has_data(rq
->bio
);
328 static inline struct ublksrv_io_desc
*ublk_get_iod(struct ublk_queue
*ubq
,
331 return (struct ublksrv_io_desc
*)
332 &(ubq
->io_cmd_buf
[tag
* sizeof(struct ublksrv_io_desc
)]);
335 static inline char *ublk_queue_cmd_buf(struct ublk_device
*ub
, int q_id
)
337 return ublk_get_queue(ub
, q_id
)->io_cmd_buf
;
340 static inline int ublk_queue_cmd_buf_size(struct ublk_device
*ub
, int q_id
)
342 struct ublk_queue
*ubq
= ublk_get_queue(ub
, q_id
);
344 return round_up(ubq
->q_depth
* sizeof(struct ublksrv_io_desc
),
348 static inline bool ublk_queue_can_use_recovery_reissue(
349 struct ublk_queue
*ubq
)
351 return (ubq
->flags
& UBLK_F_USER_RECOVERY
) &&
352 (ubq
->flags
& UBLK_F_USER_RECOVERY_REISSUE
);
355 static inline bool ublk_queue_can_use_recovery(
356 struct ublk_queue
*ubq
)
358 return ubq
->flags
& UBLK_F_USER_RECOVERY
;
361 static inline bool ublk_can_use_recovery(struct ublk_device
*ub
)
363 return ub
->dev_info
.flags
& UBLK_F_USER_RECOVERY
;
366 static void ublk_free_disk(struct gendisk
*disk
)
368 struct ublk_device
*ub
= disk
->private_data
;
370 clear_bit(UB_STATE_USED
, &ub
->state
);
371 put_device(&ub
->cdev_dev
);
374 static void ublk_store_owner_uid_gid(unsigned int *owner_uid
,
375 unsigned int *owner_gid
)
380 current_uid_gid(&uid
, &gid
);
382 *owner_uid
= from_kuid(&init_user_ns
, uid
);
383 *owner_gid
= from_kgid(&init_user_ns
, gid
);
386 static int ublk_open(struct block_device
*bdev
, fmode_t mode
)
388 struct ublk_device
*ub
= bdev
->bd_disk
->private_data
;
390 if (capable(CAP_SYS_ADMIN
))
394 * If it is one unprivileged device, only owner can open
395 * the disk. Otherwise it could be one trap made by one
396 * evil user who grants this disk's privileges to other
397 * users deliberately.
399 * This way is reasonable too given anyone can create
400 * unprivileged device, and no need other's grant.
402 if (ub
->dev_info
.flags
& UBLK_F_UNPRIVILEGED_DEV
) {
403 unsigned int curr_uid
, curr_gid
;
405 ublk_store_owner_uid_gid(&curr_uid
, &curr_gid
);
407 if (curr_uid
!= ub
->dev_info
.owner_uid
|| curr_gid
!=
408 ub
->dev_info
.owner_gid
)
415 static const struct block_device_operations ub_fops
= {
416 .owner
= THIS_MODULE
,
418 .free_disk
= ublk_free_disk
,
421 #define UBLK_MAX_PIN_PAGES 32
423 struct ublk_map_data
{
424 const struct request
*rq
;
429 struct ublk_io_iter
{
430 struct page
*pages
[UBLK_MAX_PIN_PAGES
];
431 unsigned pg_off
; /* offset in the 1st page in pages */
432 int nr_pages
; /* how many page pointers in pages */
434 struct bvec_iter iter
;
437 static inline unsigned ublk_copy_io_pages(struct ublk_io_iter
*data
,
438 unsigned max_bytes
, bool to_vm
)
440 const unsigned total
= min_t(unsigned, max_bytes
,
441 PAGE_SIZE
- data
->pg_off
+
442 ((data
->nr_pages
- 1) << PAGE_SHIFT
));
446 while (done
< total
) {
447 struct bio_vec bv
= bio_iter_iovec(data
->bio
, data
->iter
);
448 const unsigned int bytes
= min3(bv
.bv_len
, total
- done
,
449 (unsigned)(PAGE_SIZE
- data
->pg_off
));
450 void *bv_buf
= bvec_kmap_local(&bv
);
451 void *pg_buf
= kmap_local_page(data
->pages
[pg_idx
]);
454 memcpy(pg_buf
+ data
->pg_off
, bv_buf
, bytes
);
456 memcpy(bv_buf
, pg_buf
+ data
->pg_off
, bytes
);
458 kunmap_local(pg_buf
);
459 kunmap_local(bv_buf
);
461 /* advance page array */
462 data
->pg_off
+= bytes
;
463 if (data
->pg_off
== PAGE_SIZE
) {
471 bio_advance_iter_single(data
->bio
, &data
->iter
, bytes
);
472 if (!data
->iter
.bi_size
) {
473 data
->bio
= data
->bio
->bi_next
;
474 if (data
->bio
== NULL
)
476 data
->iter
= data
->bio
->bi_iter
;
483 static int ublk_copy_user_pages(struct ublk_map_data
*data
, bool to_vm
)
485 const unsigned int gup_flags
= to_vm
? FOLL_WRITE
: 0;
486 const unsigned long start_vm
= data
->ubuf
;
487 unsigned int done
= 0;
488 struct ublk_io_iter iter
= {
489 .pg_off
= start_vm
& (PAGE_SIZE
- 1),
490 .bio
= data
->rq
->bio
,
491 .iter
= data
->rq
->bio
->bi_iter
,
493 const unsigned int nr_pages
= round_up(data
->len
+
494 (start_vm
& (PAGE_SIZE
- 1)), PAGE_SIZE
) >> PAGE_SHIFT
;
496 while (done
< nr_pages
) {
497 const unsigned to_pin
= min_t(unsigned, UBLK_MAX_PIN_PAGES
,
501 iter
.nr_pages
= get_user_pages_fast(start_vm
+
502 (done
<< PAGE_SHIFT
), to_pin
, gup_flags
,
504 if (iter
.nr_pages
<= 0)
505 return done
== 0 ? iter
.nr_pages
: done
;
506 len
= ublk_copy_io_pages(&iter
, data
->len
, to_vm
);
507 for (i
= 0; i
< iter
.nr_pages
; i
++) {
509 set_page_dirty(iter
.pages
[i
]);
510 put_page(iter
.pages
[i
]);
513 done
+= iter
.nr_pages
;
519 static inline bool ublk_need_map_req(const struct request
*req
)
521 return ublk_rq_has_data(req
) && req_op(req
) == REQ_OP_WRITE
;
524 static inline bool ublk_need_unmap_req(const struct request
*req
)
526 return ublk_rq_has_data(req
) && req_op(req
) == REQ_OP_READ
;
529 static int ublk_map_io(const struct ublk_queue
*ubq
, const struct request
*req
,
532 const unsigned int rq_bytes
= blk_rq_bytes(req
);
535 * no zero copy, we delay copy WRITE request data into ublksrv
536 * context and the big benefit is that pinning pages in current
537 * context is pretty fast, see ublk_pin_user_pages
539 if (ublk_need_map_req(req
)) {
540 struct ublk_map_data data
= {
546 ublk_copy_user_pages(&data
, true);
548 return rq_bytes
- data
.len
;
553 static int ublk_unmap_io(const struct ublk_queue
*ubq
,
554 const struct request
*req
,
557 const unsigned int rq_bytes
= blk_rq_bytes(req
);
559 if (ublk_need_unmap_req(req
)) {
560 struct ublk_map_data data
= {
566 WARN_ON_ONCE(io
->res
> rq_bytes
);
568 ublk_copy_user_pages(&data
, false);
570 return io
->res
- data
.len
;
575 static inline unsigned int ublk_req_build_flags(struct request
*req
)
579 if (req
->cmd_flags
& REQ_FAILFAST_DEV
)
580 flags
|= UBLK_IO_F_FAILFAST_DEV
;
582 if (req
->cmd_flags
& REQ_FAILFAST_TRANSPORT
)
583 flags
|= UBLK_IO_F_FAILFAST_TRANSPORT
;
585 if (req
->cmd_flags
& REQ_FAILFAST_DRIVER
)
586 flags
|= UBLK_IO_F_FAILFAST_DRIVER
;
588 if (req
->cmd_flags
& REQ_META
)
589 flags
|= UBLK_IO_F_META
;
591 if (req
->cmd_flags
& REQ_FUA
)
592 flags
|= UBLK_IO_F_FUA
;
594 if (req
->cmd_flags
& REQ_NOUNMAP
)
595 flags
|= UBLK_IO_F_NOUNMAP
;
597 if (req
->cmd_flags
& REQ_SWAP
)
598 flags
|= UBLK_IO_F_SWAP
;
603 static blk_status_t
ublk_setup_iod(struct ublk_queue
*ubq
, struct request
*req
)
605 struct ublksrv_io_desc
*iod
= ublk_get_iod(ubq
, req
->tag
);
606 struct ublk_io
*io
= &ubq
->ios
[req
->tag
];
609 switch (req_op(req
)) {
611 ublk_op
= UBLK_IO_OP_READ
;
614 ublk_op
= UBLK_IO_OP_WRITE
;
617 ublk_op
= UBLK_IO_OP_FLUSH
;
620 ublk_op
= UBLK_IO_OP_DISCARD
;
622 case REQ_OP_WRITE_ZEROES
:
623 ublk_op
= UBLK_IO_OP_WRITE_ZEROES
;
626 return BLK_STS_IOERR
;
629 /* need to translate since kernel may change */
630 iod
->op_flags
= ublk_op
| ublk_req_build_flags(req
);
631 iod
->nr_sectors
= blk_rq_sectors(req
);
632 iod
->start_sector
= blk_rq_pos(req
);
633 iod
->addr
= io
->addr
;
638 static inline struct ublk_uring_cmd_pdu
*ublk_get_uring_cmd_pdu(
639 struct io_uring_cmd
*ioucmd
)
641 return (struct ublk_uring_cmd_pdu
*)&ioucmd
->pdu
;
644 static inline bool ubq_daemon_is_dying(struct ublk_queue
*ubq
)
646 return ubq
->ubq_daemon
->flags
& PF_EXITING
;
649 /* todo: handle partial completion */
650 static void ublk_complete_rq(struct request
*req
)
652 struct ublk_queue
*ubq
= req
->mq_hctx
->driver_data
;
653 struct ublk_io
*io
= &ubq
->ios
[req
->tag
];
654 unsigned int unmapped_bytes
;
655 blk_status_t res
= BLK_STS_OK
;
657 /* failed read IO if nothing is read */
658 if (!io
->res
&& req_op(req
) == REQ_OP_READ
)
662 res
= errno_to_blk_status(io
->res
);
667 * FLUSH, DISCARD or WRITE_ZEROES usually won't return bytes returned, so end them
670 * Both the two needn't unmap.
672 if (req_op(req
) != REQ_OP_READ
&& req_op(req
) != REQ_OP_WRITE
)
675 /* for READ request, writing data in iod->addr to rq buffers */
676 unmapped_bytes
= ublk_unmap_io(ubq
, req
, io
);
679 * Extremely impossible since we got data filled in just before
681 * Re-read simply for this unlikely case.
683 if (unlikely(unmapped_bytes
< io
->res
))
684 io
->res
= unmapped_bytes
;
686 if (blk_update_request(req
, BLK_STS_OK
, io
->res
))
687 blk_mq_requeue_request(req
, true);
689 __blk_mq_end_request(req
, BLK_STS_OK
);
693 blk_mq_end_request(req
, res
);
697 * Since __ublk_rq_task_work always fails requests immediately during
698 * exiting, __ublk_fail_req() is only called from abort context during
699 * exiting. So lock is unnecessary.
701 * Also aborting may not be started yet, keep in mind that one failed
702 * request may be issued by block layer again.
704 static void __ublk_fail_req(struct ublk_queue
*ubq
, struct ublk_io
*io
,
707 WARN_ON_ONCE(io
->flags
& UBLK_IO_FLAG_ACTIVE
);
709 if (!(io
->flags
& UBLK_IO_FLAG_ABORTED
)) {
710 io
->flags
|= UBLK_IO_FLAG_ABORTED
;
711 if (ublk_queue_can_use_recovery_reissue(ubq
))
712 blk_mq_requeue_request(req
, false);
714 blk_mq_end_request(req
, BLK_STS_IOERR
);
718 static void ubq_complete_io_cmd(struct ublk_io
*io
, int res
)
720 /* mark this cmd owned by ublksrv */
721 io
->flags
|= UBLK_IO_FLAG_OWNED_BY_SRV
;
724 * clear ACTIVE since we are done with this sqe/cmd slot
725 * We can only accept io cmd in case of being not active.
727 io
->flags
&= ~UBLK_IO_FLAG_ACTIVE
;
729 /* tell ublksrv one io request is coming */
730 io_uring_cmd_done(io
->cmd
, res
, 0);
733 #define UBLK_REQUEUE_DELAY_MS 3
735 static inline void __ublk_abort_rq(struct ublk_queue
*ubq
,
738 /* We cannot process this rq so just requeue it. */
739 if (ublk_queue_can_use_recovery(ubq
))
740 blk_mq_requeue_request(rq
, false);
742 blk_mq_end_request(rq
, BLK_STS_IOERR
);
744 mod_delayed_work(system_wq
, &ubq
->dev
->monitor_work
, 0);
747 static inline void __ublk_rq_task_work(struct request
*req
)
749 struct ublk_queue
*ubq
= req
->mq_hctx
->driver_data
;
751 struct ublk_io
*io
= &ubq
->ios
[tag
];
752 unsigned int mapped_bytes
;
754 pr_devel("%s: complete: op %d, qid %d tag %d io_flags %x addr %llx\n",
755 __func__
, io
->cmd
->cmd_op
, ubq
->q_id
, req
->tag
, io
->flags
,
756 ublk_get_iod(ubq
, req
->tag
)->addr
);
759 * Task is exiting if either:
761 * (1) current != ubq_daemon.
762 * io_uring_cmd_complete_in_task() tries to run task_work
763 * in a workqueue if ubq_daemon(cmd's task) is PF_EXITING.
765 * (2) current->flags & PF_EXITING.
767 if (unlikely(current
!= ubq
->ubq_daemon
|| current
->flags
& PF_EXITING
)) {
768 __ublk_abort_rq(ubq
, req
);
772 if (ublk_need_get_data(ubq
) && ublk_need_map_req(req
)) {
774 * We have not handled UBLK_IO_NEED_GET_DATA command yet,
775 * so immepdately pass UBLK_IO_RES_NEED_GET_DATA to ublksrv
778 if (!(io
->flags
& UBLK_IO_FLAG_NEED_GET_DATA
)) {
779 io
->flags
|= UBLK_IO_FLAG_NEED_GET_DATA
;
780 pr_devel("%s: need get data. op %d, qid %d tag %d io_flags %x\n",
781 __func__
, io
->cmd
->cmd_op
, ubq
->q_id
,
782 req
->tag
, io
->flags
);
783 ubq_complete_io_cmd(io
, UBLK_IO_RES_NEED_GET_DATA
);
787 * We have handled UBLK_IO_NEED_GET_DATA command,
788 * so clear UBLK_IO_FLAG_NEED_GET_DATA now and just
791 io
->flags
&= ~UBLK_IO_FLAG_NEED_GET_DATA
;
792 /* update iod->addr because ublksrv may have passed a new io buffer */
793 ublk_get_iod(ubq
, req
->tag
)->addr
= io
->addr
;
794 pr_devel("%s: update iod->addr: op %d, qid %d tag %d io_flags %x addr %llx\n",
795 __func__
, io
->cmd
->cmd_op
, ubq
->q_id
, req
->tag
, io
->flags
,
796 ublk_get_iod(ubq
, req
->tag
)->addr
);
799 mapped_bytes
= ublk_map_io(ubq
, req
, io
);
801 /* partially mapped, update io descriptor */
802 if (unlikely(mapped_bytes
!= blk_rq_bytes(req
))) {
804 * Nothing mapped, retry until we succeed.
806 * We may never succeed in mapping any bytes here because
807 * of OOM. TODO: reserve one buffer with single page pinned
808 * for providing forward progress guarantee.
810 if (unlikely(!mapped_bytes
)) {
811 blk_mq_requeue_request(req
, false);
812 blk_mq_delay_kick_requeue_list(req
->q
,
813 UBLK_REQUEUE_DELAY_MS
);
817 ublk_get_iod(ubq
, req
->tag
)->nr_sectors
=
821 ubq_complete_io_cmd(io
, UBLK_IO_RES_OK
);
824 static inline void ublk_forward_io_cmds(struct ublk_queue
*ubq
)
826 struct llist_node
*io_cmds
= llist_del_all(&ubq
->io_cmds
);
827 struct ublk_rq_data
*data
, *tmp
;
829 io_cmds
= llist_reverse_order(io_cmds
);
830 llist_for_each_entry_safe(data
, tmp
, io_cmds
, node
)
831 __ublk_rq_task_work(blk_mq_rq_from_pdu(data
));
834 static inline void ublk_abort_io_cmds(struct ublk_queue
*ubq
)
836 struct llist_node
*io_cmds
= llist_del_all(&ubq
->io_cmds
);
837 struct ublk_rq_data
*data
, *tmp
;
839 llist_for_each_entry_safe(data
, tmp
, io_cmds
, node
)
840 __ublk_abort_rq(ubq
, blk_mq_rq_from_pdu(data
));
843 static void ublk_rq_task_work_cb(struct io_uring_cmd
*cmd
)
845 struct ublk_uring_cmd_pdu
*pdu
= ublk_get_uring_cmd_pdu(cmd
);
846 struct ublk_queue
*ubq
= pdu
->ubq
;
848 ublk_forward_io_cmds(ubq
);
851 static void ublk_rq_task_work_fn(struct callback_head
*work
)
853 struct ublk_rq_data
*data
= container_of(work
,
854 struct ublk_rq_data
, work
);
855 struct request
*req
= blk_mq_rq_from_pdu(data
);
856 struct ublk_queue
*ubq
= req
->mq_hctx
->driver_data
;
858 ublk_forward_io_cmds(ubq
);
861 static void ublk_queue_cmd(struct ublk_queue
*ubq
, struct request
*rq
)
863 struct ublk_rq_data
*data
= blk_mq_rq_to_pdu(rq
);
866 if (!llist_add(&data
->node
, &ubq
->io_cmds
))
869 io
= &ubq
->ios
[rq
->tag
];
871 * If the check pass, we know that this is a re-issued request aborted
872 * previously in monitor_work because the ubq_daemon(cmd's task) is
873 * PF_EXITING. We cannot call io_uring_cmd_complete_in_task() anymore
874 * because this ioucmd's io_uring context may be freed now if no inflight
875 * ioucmd exists. Otherwise we may cause null-deref in ctx->fallback_work.
877 * Note: monitor_work sets UBLK_IO_FLAG_ABORTED and ends this request(releasing
878 * the tag). Then the request is re-started(allocating the tag) and we are here.
879 * Since releasing/allocating a tag implies smp_mb(), finding UBLK_IO_FLAG_ABORTED
880 * guarantees that here is a re-issued request aborted previously.
882 if (unlikely(io
->flags
& UBLK_IO_FLAG_ABORTED
)) {
883 ublk_abort_io_cmds(ubq
);
884 } else if (ublk_can_use_task_work(ubq
)) {
885 if (task_work_add(ubq
->ubq_daemon
, &data
->work
,
887 ublk_abort_io_cmds(ubq
);
889 struct io_uring_cmd
*cmd
= io
->cmd
;
890 struct ublk_uring_cmd_pdu
*pdu
= ublk_get_uring_cmd_pdu(cmd
);
893 io_uring_cmd_complete_in_task(cmd
, ublk_rq_task_work_cb
);
897 static blk_status_t
ublk_queue_rq(struct blk_mq_hw_ctx
*hctx
,
898 const struct blk_mq_queue_data
*bd
)
900 struct ublk_queue
*ubq
= hctx
->driver_data
;
901 struct request
*rq
= bd
->rq
;
904 /* fill iod to slot in io cmd buffer */
905 res
= ublk_setup_iod(ubq
, rq
);
906 if (unlikely(res
!= BLK_STS_OK
))
907 return BLK_STS_IOERR
;
909 /* With recovery feature enabled, force_abort is set in
910 * ublk_stop_dev() before calling del_gendisk(). We have to
911 * abort all requeued and new rqs here to let del_gendisk()
912 * move on. Besides, we cannot not call io_uring_cmd_complete_in_task()
913 * to avoid UAF on io_uring ctx.
915 * Note: force_abort is guaranteed to be seen because it is set
916 * before request queue is unqiuesced.
918 if (ublk_queue_can_use_recovery(ubq
) && unlikely(ubq
->force_abort
))
919 return BLK_STS_IOERR
;
921 blk_mq_start_request(bd
->rq
);
923 if (unlikely(ubq_daemon_is_dying(ubq
))) {
924 __ublk_abort_rq(ubq
, rq
);
928 ublk_queue_cmd(ubq
, rq
);
933 static int ublk_init_hctx(struct blk_mq_hw_ctx
*hctx
, void *driver_data
,
934 unsigned int hctx_idx
)
936 struct ublk_device
*ub
= driver_data
;
937 struct ublk_queue
*ubq
= ublk_get_queue(ub
, hctx
->queue_num
);
939 hctx
->driver_data
= ubq
;
943 static int ublk_init_rq(struct blk_mq_tag_set
*set
, struct request
*req
,
944 unsigned int hctx_idx
, unsigned int numa_node
)
946 struct ublk_rq_data
*data
= blk_mq_rq_to_pdu(req
);
948 init_task_work(&data
->work
, ublk_rq_task_work_fn
);
952 static const struct blk_mq_ops ublk_mq_ops
= {
953 .queue_rq
= ublk_queue_rq
,
954 .init_hctx
= ublk_init_hctx
,
955 .init_request
= ublk_init_rq
,
958 static int ublk_ch_open(struct inode
*inode
, struct file
*filp
)
960 struct ublk_device
*ub
= container_of(inode
->i_cdev
,
961 struct ublk_device
, cdev
);
963 if (test_and_set_bit(UB_STATE_OPEN
, &ub
->state
))
965 filp
->private_data
= ub
;
969 static int ublk_ch_release(struct inode
*inode
, struct file
*filp
)
971 struct ublk_device
*ub
= filp
->private_data
;
973 clear_bit(UB_STATE_OPEN
, &ub
->state
);
977 /* map pre-allocated per-queue cmd buffer to ublksrv daemon */
978 static int ublk_ch_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
980 struct ublk_device
*ub
= filp
->private_data
;
981 size_t sz
= vma
->vm_end
- vma
->vm_start
;
982 unsigned max_sz
= UBLK_MAX_QUEUE_DEPTH
* sizeof(struct ublksrv_io_desc
);
983 unsigned long pfn
, end
, phys_off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
986 spin_lock(&ub
->mm_lock
);
988 ub
->mm
= current
->mm
;
989 if (current
->mm
!= ub
->mm
)
991 spin_unlock(&ub
->mm_lock
);
996 if (vma
->vm_flags
& VM_WRITE
)
999 end
= UBLKSRV_CMD_BUF_OFFSET
+ ub
->dev_info
.nr_hw_queues
* max_sz
;
1000 if (phys_off
< UBLKSRV_CMD_BUF_OFFSET
|| phys_off
>= end
)
1003 q_id
= (phys_off
- UBLKSRV_CMD_BUF_OFFSET
) / max_sz
;
1004 pr_devel("%s: qid %d, pid %d, addr %lx pg_off %lx sz %lu\n",
1005 __func__
, q_id
, current
->pid
, vma
->vm_start
,
1006 phys_off
, (unsigned long)sz
);
1008 if (sz
!= ublk_queue_cmd_buf_size(ub
, q_id
))
1011 pfn
= virt_to_phys(ublk_queue_cmd_buf(ub
, q_id
)) >> PAGE_SHIFT
;
1012 return remap_pfn_range(vma
, vma
->vm_start
, pfn
, sz
, vma
->vm_page_prot
);
1015 static void ublk_commit_completion(struct ublk_device
*ub
,
1016 struct ublksrv_io_cmd
*ub_cmd
)
1018 u32 qid
= ub_cmd
->q_id
, tag
= ub_cmd
->tag
;
1019 struct ublk_queue
*ubq
= ublk_get_queue(ub
, qid
);
1020 struct ublk_io
*io
= &ubq
->ios
[tag
];
1021 struct request
*req
;
1023 /* now this cmd slot is owned by nbd driver */
1024 io
->flags
&= ~UBLK_IO_FLAG_OWNED_BY_SRV
;
1025 io
->res
= ub_cmd
->result
;
1027 /* find the io request and complete */
1028 req
= blk_mq_tag_to_rq(ub
->tag_set
.tags
[qid
], tag
);
1030 if (req
&& likely(!blk_should_fake_timeout(req
->q
)))
1031 ublk_complete_rq(req
);
1035 * When ->ubq_daemon is exiting, either new request is ended immediately,
1036 * or any queued io command is drained, so it is safe to abort queue
1039 static void ublk_abort_queue(struct ublk_device
*ub
, struct ublk_queue
*ubq
)
1043 if (!ublk_get_device(ub
))
1046 for (i
= 0; i
< ubq
->q_depth
; i
++) {
1047 struct ublk_io
*io
= &ubq
->ios
[i
];
1049 if (!(io
->flags
& UBLK_IO_FLAG_ACTIVE
)) {
1053 * Either we fail the request or ublk_rq_task_work_fn
1056 rq
= blk_mq_tag_to_rq(ub
->tag_set
.tags
[ubq
->q_id
], i
);
1058 __ublk_fail_req(ubq
, io
, rq
);
1061 ublk_put_device(ub
);
1064 static void ublk_daemon_monitor_work(struct work_struct
*work
)
1066 struct ublk_device
*ub
=
1067 container_of(work
, struct ublk_device
, monitor_work
.work
);
1070 for (i
= 0; i
< ub
->dev_info
.nr_hw_queues
; i
++) {
1071 struct ublk_queue
*ubq
= ublk_get_queue(ub
, i
);
1073 if (ubq_daemon_is_dying(ubq
)) {
1074 if (ublk_queue_can_use_recovery(ubq
))
1075 schedule_work(&ub
->quiesce_work
);
1077 schedule_work(&ub
->stop_work
);
1079 /* abort queue is for making forward progress */
1080 ublk_abort_queue(ub
, ubq
);
1085 * We can't schedule monitor work after ub's state is not UBLK_S_DEV_LIVE.
1086 * after ublk_remove() or __ublk_quiesce_dev() is started.
1088 * No need ub->mutex, monitor work are canceled after state is marked
1089 * as not LIVE, so new state is observed reliably.
1091 if (ub
->dev_info
.state
== UBLK_S_DEV_LIVE
)
1092 schedule_delayed_work(&ub
->monitor_work
,
1093 UBLK_DAEMON_MONITOR_PERIOD
);
1096 static inline bool ublk_queue_ready(struct ublk_queue
*ubq
)
1098 return ubq
->nr_io_ready
== ubq
->q_depth
;
1101 static void ublk_cancel_queue(struct ublk_queue
*ubq
)
1105 if (!ublk_queue_ready(ubq
))
1108 for (i
= 0; i
< ubq
->q_depth
; i
++) {
1109 struct ublk_io
*io
= &ubq
->ios
[i
];
1111 if (io
->flags
& UBLK_IO_FLAG_ACTIVE
)
1112 io_uring_cmd_done(io
->cmd
, UBLK_IO_RES_ABORT
, 0);
1115 /* all io commands are canceled */
1116 ubq
->nr_io_ready
= 0;
1119 /* Cancel all pending commands, must be called after del_gendisk() returns */
1120 static void ublk_cancel_dev(struct ublk_device
*ub
)
1124 for (i
= 0; i
< ub
->dev_info
.nr_hw_queues
; i
++)
1125 ublk_cancel_queue(ublk_get_queue(ub
, i
));
1128 static bool ublk_check_inflight_rq(struct request
*rq
, void *data
)
1132 if (blk_mq_request_started(rq
)) {
1139 static void ublk_wait_tagset_rqs_idle(struct ublk_device
*ub
)
1143 WARN_ON_ONCE(!blk_queue_quiesced(ub
->ub_disk
->queue
));
1146 blk_mq_tagset_busy_iter(&ub
->tag_set
,
1147 ublk_check_inflight_rq
, &idle
);
1150 msleep(UBLK_REQUEUE_DELAY_MS
);
1154 static void __ublk_quiesce_dev(struct ublk_device
*ub
)
1156 pr_devel("%s: quiesce ub: dev_id %d state %s\n",
1157 __func__
, ub
->dev_info
.dev_id
,
1158 ub
->dev_info
.state
== UBLK_S_DEV_LIVE
?
1159 "LIVE" : "QUIESCED");
1160 blk_mq_quiesce_queue(ub
->ub_disk
->queue
);
1161 ublk_wait_tagset_rqs_idle(ub
);
1162 ub
->dev_info
.state
= UBLK_S_DEV_QUIESCED
;
1163 ublk_cancel_dev(ub
);
1164 /* we are going to release task_struct of ubq_daemon and resets
1165 * ->ubq_daemon to NULL. So in monitor_work, check on ubq_daemon causes UAF.
1166 * Besides, monitor_work is not necessary in QUIESCED state since we have
1167 * already scheduled quiesce_work and quiesced all ubqs.
1169 * Do not let monitor_work schedule itself if state it QUIESCED. And we cancel
1170 * it here and re-schedule it in END_USER_RECOVERY to avoid UAF.
1172 cancel_delayed_work_sync(&ub
->monitor_work
);
1175 static void ublk_quiesce_work_fn(struct work_struct
*work
)
1177 struct ublk_device
*ub
=
1178 container_of(work
, struct ublk_device
, quiesce_work
);
1180 mutex_lock(&ub
->mutex
);
1181 if (ub
->dev_info
.state
!= UBLK_S_DEV_LIVE
)
1183 __ublk_quiesce_dev(ub
);
1185 mutex_unlock(&ub
->mutex
);
1188 static void ublk_unquiesce_dev(struct ublk_device
*ub
)
1192 pr_devel("%s: unquiesce ub: dev_id %d state %s\n",
1193 __func__
, ub
->dev_info
.dev_id
,
1194 ub
->dev_info
.state
== UBLK_S_DEV_LIVE
?
1195 "LIVE" : "QUIESCED");
1196 /* quiesce_work has run. We let requeued rqs be aborted
1197 * before running fallback_wq. "force_abort" must be seen
1198 * after request queue is unqiuesced. Then del_gendisk()
1201 for (i
= 0; i
< ub
->dev_info
.nr_hw_queues
; i
++)
1202 ublk_get_queue(ub
, i
)->force_abort
= true;
1204 blk_mq_unquiesce_queue(ub
->ub_disk
->queue
);
1205 /* We may have requeued some rqs in ublk_quiesce_queue() */
1206 blk_mq_kick_requeue_list(ub
->ub_disk
->queue
);
1209 static void ublk_stop_dev(struct ublk_device
*ub
)
1211 mutex_lock(&ub
->mutex
);
1212 if (ub
->dev_info
.state
== UBLK_S_DEV_DEAD
)
1214 if (ublk_can_use_recovery(ub
)) {
1215 if (ub
->dev_info
.state
== UBLK_S_DEV_LIVE
)
1216 __ublk_quiesce_dev(ub
);
1217 ublk_unquiesce_dev(ub
);
1219 del_gendisk(ub
->ub_disk
);
1220 ub
->dev_info
.state
= UBLK_S_DEV_DEAD
;
1221 ub
->dev_info
.ublksrv_pid
= -1;
1222 put_disk(ub
->ub_disk
);
1225 ublk_cancel_dev(ub
);
1226 mutex_unlock(&ub
->mutex
);
1227 cancel_delayed_work_sync(&ub
->monitor_work
);
1230 /* device can only be started after all IOs are ready */
1231 static void ublk_mark_io_ready(struct ublk_device
*ub
, struct ublk_queue
*ubq
)
1233 mutex_lock(&ub
->mutex
);
1235 if (ublk_queue_ready(ubq
)) {
1236 ubq
->ubq_daemon
= current
;
1237 get_task_struct(ubq
->ubq_daemon
);
1238 ub
->nr_queues_ready
++;
1240 if (capable(CAP_SYS_ADMIN
))
1241 ub
->nr_privileged_daemon
++;
1243 if (ub
->nr_queues_ready
== ub
->dev_info
.nr_hw_queues
)
1244 complete_all(&ub
->completion
);
1245 mutex_unlock(&ub
->mutex
);
1248 static void ublk_handle_need_get_data(struct ublk_device
*ub
, int q_id
,
1251 struct ublk_queue
*ubq
= ublk_get_queue(ub
, q_id
);
1252 struct request
*req
= blk_mq_tag_to_rq(ub
->tag_set
.tags
[q_id
], tag
);
1254 ublk_queue_cmd(ubq
, req
);
1257 static inline int ublk_check_cmd_op(u32 cmd_op
)
1259 u32 ioc_type
= _IOC_TYPE(cmd_op
);
1261 if (IS_ENABLED(CONFIG_BLKDEV_UBLK_LEGACY_OPCODES
) && ioc_type
!= 'u')
1264 if (ioc_type
!= 'u' && ioc_type
!= 0)
1270 static int ublk_ch_uring_cmd(struct io_uring_cmd
*cmd
, unsigned int issue_flags
)
1272 struct ublksrv_io_cmd
*ub_cmd
= (struct ublksrv_io_cmd
*)cmd
->cmd
;
1273 struct ublk_device
*ub
= cmd
->file
->private_data
;
1274 struct ublk_queue
*ubq
;
1276 u32 cmd_op
= cmd
->cmd_op
;
1277 unsigned tag
= ub_cmd
->tag
;
1279 struct request
*req
;
1281 pr_devel("%s: received: cmd op %d queue %d tag %d result %d\n",
1282 __func__
, cmd
->cmd_op
, ub_cmd
->q_id
, tag
,
1285 if (ub_cmd
->q_id
>= ub
->dev_info
.nr_hw_queues
)
1288 ubq
= ublk_get_queue(ub
, ub_cmd
->q_id
);
1289 if (!ubq
|| ub_cmd
->q_id
!= ubq
->q_id
)
1292 if (ubq
->ubq_daemon
&& ubq
->ubq_daemon
!= current
)
1295 if (tag
>= ubq
->q_depth
)
1298 io
= &ubq
->ios
[tag
];
1300 /* there is pending io cmd, something must be wrong */
1301 if (io
->flags
& UBLK_IO_FLAG_ACTIVE
) {
1307 * ensure that the user issues UBLK_IO_NEED_GET_DATA
1308 * iff the driver have set the UBLK_IO_FLAG_NEED_GET_DATA.
1310 if ((!!(io
->flags
& UBLK_IO_FLAG_NEED_GET_DATA
))
1311 ^ (_IOC_NR(cmd_op
) == UBLK_IO_NEED_GET_DATA
))
1314 ret
= ublk_check_cmd_op(cmd_op
);
1318 switch (_IOC_NR(cmd_op
)) {
1319 case UBLK_IO_FETCH_REQ
:
1320 /* UBLK_IO_FETCH_REQ is only allowed before queue is setup */
1321 if (ublk_queue_ready(ubq
)) {
1326 * The io is being handled by server, so COMMIT_RQ is expected
1327 * instead of FETCH_REQ
1329 if (io
->flags
& UBLK_IO_FLAG_OWNED_BY_SRV
)
1331 /* FETCH_RQ has to provide IO buffer if NEED GET DATA is not enabled */
1332 if (!ub_cmd
->addr
&& !ublk_need_get_data(ubq
))
1335 io
->flags
|= UBLK_IO_FLAG_ACTIVE
;
1336 io
->addr
= ub_cmd
->addr
;
1338 ublk_mark_io_ready(ub
, ubq
);
1340 case UBLK_IO_COMMIT_AND_FETCH_REQ
:
1341 req
= blk_mq_tag_to_rq(ub
->tag_set
.tags
[ub_cmd
->q_id
], tag
);
1343 * COMMIT_AND_FETCH_REQ has to provide IO buffer if NEED GET DATA is
1344 * not enabled or it is Read IO.
1346 if (!ub_cmd
->addr
&& (!ublk_need_get_data(ubq
) || req_op(req
) == REQ_OP_READ
))
1348 if (!(io
->flags
& UBLK_IO_FLAG_OWNED_BY_SRV
))
1350 io
->addr
= ub_cmd
->addr
;
1351 io
->flags
|= UBLK_IO_FLAG_ACTIVE
;
1353 ublk_commit_completion(ub
, ub_cmd
);
1355 case UBLK_IO_NEED_GET_DATA
:
1356 if (!(io
->flags
& UBLK_IO_FLAG_OWNED_BY_SRV
))
1358 io
->addr
= ub_cmd
->addr
;
1360 io
->flags
|= UBLK_IO_FLAG_ACTIVE
;
1361 ublk_handle_need_get_data(ub
, ub_cmd
->q_id
, ub_cmd
->tag
);
1366 return -EIOCBQUEUED
;
1369 io_uring_cmd_done(cmd
, ret
, 0);
1370 pr_devel("%s: complete: cmd op %d, tag %d ret %x io_flags %x\n",
1371 __func__
, cmd_op
, tag
, ret
, io
->flags
);
1372 return -EIOCBQUEUED
;
1375 static const struct file_operations ublk_ch_fops
= {
1376 .owner
= THIS_MODULE
,
1377 .open
= ublk_ch_open
,
1378 .release
= ublk_ch_release
,
1379 .llseek
= no_llseek
,
1380 .uring_cmd
= ublk_ch_uring_cmd
,
1381 .mmap
= ublk_ch_mmap
,
1384 static void ublk_deinit_queue(struct ublk_device
*ub
, int q_id
)
1386 int size
= ublk_queue_cmd_buf_size(ub
, q_id
);
1387 struct ublk_queue
*ubq
= ublk_get_queue(ub
, q_id
);
1389 if (ubq
->ubq_daemon
)
1390 put_task_struct(ubq
->ubq_daemon
);
1391 if (ubq
->io_cmd_buf
)
1392 free_pages((unsigned long)ubq
->io_cmd_buf
, get_order(size
));
1395 static int ublk_init_queue(struct ublk_device
*ub
, int q_id
)
1397 struct ublk_queue
*ubq
= ublk_get_queue(ub
, q_id
);
1398 gfp_t gfp_flags
= GFP_KERNEL
| __GFP_ZERO
;
1402 ubq
->flags
= ub
->dev_info
.flags
;
1404 ubq
->q_depth
= ub
->dev_info
.queue_depth
;
1405 size
= ublk_queue_cmd_buf_size(ub
, q_id
);
1407 ptr
= (void *) __get_free_pages(gfp_flags
, get_order(size
));
1411 ubq
->io_cmd_buf
= ptr
;
1416 static void ublk_deinit_queues(struct ublk_device
*ub
)
1418 int nr_queues
= ub
->dev_info
.nr_hw_queues
;
1424 for (i
= 0; i
< nr_queues
; i
++)
1425 ublk_deinit_queue(ub
, i
);
1426 kfree(ub
->__queues
);
1429 static int ublk_init_queues(struct ublk_device
*ub
)
1431 int nr_queues
= ub
->dev_info
.nr_hw_queues
;
1432 int depth
= ub
->dev_info
.queue_depth
;
1433 int ubq_size
= sizeof(struct ublk_queue
) + depth
* sizeof(struct ublk_io
);
1434 int i
, ret
= -ENOMEM
;
1436 ub
->queue_size
= ubq_size
;
1437 ub
->__queues
= kcalloc(nr_queues
, ubq_size
, GFP_KERNEL
);
1441 for (i
= 0; i
< nr_queues
; i
++) {
1442 if (ublk_init_queue(ub
, i
))
1446 init_completion(&ub
->completion
);
1450 ublk_deinit_queues(ub
);
1454 static int ublk_alloc_dev_number(struct ublk_device
*ub
, int idx
)
1459 spin_lock(&ublk_idr_lock
);
1460 /* allocate id, if @id >= 0, we're requesting that specific id */
1462 err
= idr_alloc(&ublk_index_idr
, ub
, i
, i
+ 1, GFP_NOWAIT
);
1466 err
= idr_alloc(&ublk_index_idr
, ub
, 0, 0, GFP_NOWAIT
);
1468 spin_unlock(&ublk_idr_lock
);
1471 ub
->ub_number
= err
;
1476 static void ublk_free_dev_number(struct ublk_device
*ub
)
1478 spin_lock(&ublk_idr_lock
);
1479 idr_remove(&ublk_index_idr
, ub
->ub_number
);
1480 wake_up_all(&ublk_idr_wq
);
1481 spin_unlock(&ublk_idr_lock
);
1484 static void ublk_cdev_rel(struct device
*dev
)
1486 struct ublk_device
*ub
= container_of(dev
, struct ublk_device
, cdev_dev
);
1488 blk_mq_free_tag_set(&ub
->tag_set
);
1489 ublk_deinit_queues(ub
);
1490 ublk_free_dev_number(ub
);
1491 mutex_destroy(&ub
->mutex
);
1495 static int ublk_add_chdev(struct ublk_device
*ub
)
1497 struct device
*dev
= &ub
->cdev_dev
;
1498 int minor
= ub
->ub_number
;
1501 dev
->parent
= ublk_misc
.this_device
;
1502 dev
->devt
= MKDEV(MAJOR(ublk_chr_devt
), minor
);
1503 dev
->class = ublk_chr_class
;
1504 dev
->release
= ublk_cdev_rel
;
1505 device_initialize(dev
);
1507 ret
= dev_set_name(dev
, "ublkc%d", minor
);
1511 cdev_init(&ub
->cdev
, &ublk_ch_fops
);
1512 ret
= cdev_device_add(&ub
->cdev
, dev
);
1523 static void ublk_stop_work_fn(struct work_struct
*work
)
1525 struct ublk_device
*ub
=
1526 container_of(work
, struct ublk_device
, stop_work
);
1531 /* align max io buffer size with PAGE_SIZE */
1532 static void ublk_align_max_io_size(struct ublk_device
*ub
)
1534 unsigned int max_io_bytes
= ub
->dev_info
.max_io_buf_bytes
;
1536 ub
->dev_info
.max_io_buf_bytes
=
1537 round_down(max_io_bytes
, PAGE_SIZE
);
1540 static int ublk_add_tag_set(struct ublk_device
*ub
)
1542 ub
->tag_set
.ops
= &ublk_mq_ops
;
1543 ub
->tag_set
.nr_hw_queues
= ub
->dev_info
.nr_hw_queues
;
1544 ub
->tag_set
.queue_depth
= ub
->dev_info
.queue_depth
;
1545 ub
->tag_set
.numa_node
= NUMA_NO_NODE
;
1546 ub
->tag_set
.cmd_size
= sizeof(struct ublk_rq_data
);
1547 ub
->tag_set
.flags
= BLK_MQ_F_SHOULD_MERGE
;
1548 ub
->tag_set
.driver_data
= ub
;
1549 return blk_mq_alloc_tag_set(&ub
->tag_set
);
1552 static void ublk_remove(struct ublk_device
*ub
)
1555 cancel_work_sync(&ub
->stop_work
);
1556 cancel_work_sync(&ub
->quiesce_work
);
1557 cdev_device_del(&ub
->cdev
, &ub
->cdev_dev
);
1558 put_device(&ub
->cdev_dev
);
1562 static struct ublk_device
*ublk_get_device_from_id(int idx
)
1564 struct ublk_device
*ub
= NULL
;
1569 spin_lock(&ublk_idr_lock
);
1570 ub
= idr_find(&ublk_index_idr
, idx
);
1572 ub
= ublk_get_device(ub
);
1573 spin_unlock(&ublk_idr_lock
);
1578 static int ublk_ctrl_start_dev(struct ublk_device
*ub
, struct io_uring_cmd
*cmd
)
1580 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1581 int ublksrv_pid
= (int)header
->data
[0];
1582 struct gendisk
*disk
;
1585 if (ublksrv_pid
<= 0)
1588 wait_for_completion_interruptible(&ub
->completion
);
1590 schedule_delayed_work(&ub
->monitor_work
, UBLK_DAEMON_MONITOR_PERIOD
);
1592 mutex_lock(&ub
->mutex
);
1593 if (ub
->dev_info
.state
== UBLK_S_DEV_LIVE
||
1594 test_bit(UB_STATE_USED
, &ub
->state
)) {
1599 disk
= blk_mq_alloc_disk(&ub
->tag_set
, NULL
);
1601 ret
= PTR_ERR(disk
);
1604 sprintf(disk
->disk_name
, "ublkb%d", ub
->ub_number
);
1605 disk
->fops
= &ub_fops
;
1606 disk
->private_data
= ub
;
1608 ub
->dev_info
.ublksrv_pid
= ublksrv_pid
;
1611 ret
= ublk_apply_params(ub
);
1615 /* don't probe partitions if any one ubq daemon is un-trusted */
1616 if (ub
->nr_privileged_daemon
!= ub
->nr_queues_ready
)
1617 set_bit(GD_SUPPRESS_PART_SCAN
, &disk
->state
);
1619 get_device(&ub
->cdev_dev
);
1620 ret
= add_disk(disk
);
1623 * Has to drop the reference since ->free_disk won't be
1624 * called in case of add_disk failure.
1626 ublk_put_device(ub
);
1629 set_bit(UB_STATE_USED
, &ub
->state
);
1630 ub
->dev_info
.state
= UBLK_S_DEV_LIVE
;
1635 mutex_unlock(&ub
->mutex
);
1639 static int ublk_ctrl_get_queue_affinity(struct ublk_device
*ub
,
1640 struct io_uring_cmd
*cmd
)
1642 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1643 void __user
*argp
= (void __user
*)(unsigned long)header
->addr
;
1644 cpumask_var_t cpumask
;
1645 unsigned long queue
;
1646 unsigned int retlen
;
1650 if (header
->len
* BITS_PER_BYTE
< nr_cpu_ids
)
1652 if (header
->len
& (sizeof(unsigned long)-1))
1657 queue
= header
->data
[0];
1658 if (queue
>= ub
->dev_info
.nr_hw_queues
)
1661 if (!zalloc_cpumask_var(&cpumask
, GFP_KERNEL
))
1664 for_each_possible_cpu(i
) {
1665 if (ub
->tag_set
.map
[HCTX_TYPE_DEFAULT
].mq_map
[i
] == queue
)
1666 cpumask_set_cpu(i
, cpumask
);
1670 retlen
= min_t(unsigned short, header
->len
, cpumask_size());
1671 if (copy_to_user(argp
, cpumask
, retlen
))
1672 goto out_free_cpumask
;
1673 if (retlen
!= header
->len
&&
1674 clear_user(argp
+ retlen
, header
->len
- retlen
))
1675 goto out_free_cpumask
;
1679 free_cpumask_var(cpumask
);
1683 static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info
*info
)
1685 pr_devel("%s: dev id %d flags %llx\n", __func__
,
1686 info
->dev_id
, info
->flags
);
1687 pr_devel("\t nr_hw_queues %d queue_depth %d\n",
1688 info
->nr_hw_queues
, info
->queue_depth
);
1691 static int ublk_ctrl_add_dev(struct io_uring_cmd
*cmd
)
1693 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1694 void __user
*argp
= (void __user
*)(unsigned long)header
->addr
;
1695 struct ublksrv_ctrl_dev_info info
;
1696 struct ublk_device
*ub
;
1699 if (header
->len
< sizeof(info
) || !header
->addr
)
1701 if (header
->queue_id
!= (u16
)-1) {
1702 pr_warn("%s: queue_id is wrong %x\n",
1703 __func__
, header
->queue_id
);
1707 if (copy_from_user(&info
, argp
, sizeof(info
)))
1710 if (capable(CAP_SYS_ADMIN
))
1711 info
.flags
&= ~UBLK_F_UNPRIVILEGED_DEV
;
1712 else if (!(info
.flags
& UBLK_F_UNPRIVILEGED_DEV
))
1715 /* the created device is always owned by current user */
1716 ublk_store_owner_uid_gid(&info
.owner_uid
, &info
.owner_gid
);
1718 if (header
->dev_id
!= info
.dev_id
) {
1719 pr_warn("%s: dev id not match %u %u\n",
1720 __func__
, header
->dev_id
, info
.dev_id
);
1724 ublk_dump_dev_info(&info
);
1726 ret
= mutex_lock_killable(&ublk_ctl_mutex
);
1731 if (ublks_added
>= ublks_max
)
1735 ub
= kzalloc(sizeof(*ub
), GFP_KERNEL
);
1738 mutex_init(&ub
->mutex
);
1739 spin_lock_init(&ub
->mm_lock
);
1740 INIT_WORK(&ub
->quiesce_work
, ublk_quiesce_work_fn
);
1741 INIT_WORK(&ub
->stop_work
, ublk_stop_work_fn
);
1742 INIT_DELAYED_WORK(&ub
->monitor_work
, ublk_daemon_monitor_work
);
1744 ret
= ublk_alloc_dev_number(ub
, header
->dev_id
);
1748 memcpy(&ub
->dev_info
, &info
, sizeof(info
));
1750 /* update device id */
1751 ub
->dev_info
.dev_id
= ub
->ub_number
;
1754 * 64bit flags will be copied back to userspace as feature
1755 * negotiation result, so have to clear flags which driver
1756 * doesn't support yet, then userspace can get correct flags
1757 * (features) to handle.
1759 ub
->dev_info
.flags
&= UBLK_F_ALL
;
1761 if (!IS_BUILTIN(CONFIG_BLK_DEV_UBLK
))
1762 ub
->dev_info
.flags
|= UBLK_F_URING_CMD_COMP_IN_TASK
;
1764 ub
->dev_info
.flags
|= UBLK_F_CMD_IOCTL_ENCODE
;
1766 /* We are not ready to support zero copy */
1767 ub
->dev_info
.flags
&= ~UBLK_F_SUPPORT_ZERO_COPY
;
1769 ub
->dev_info
.nr_hw_queues
= min_t(unsigned int,
1770 ub
->dev_info
.nr_hw_queues
, nr_cpu_ids
);
1771 ublk_align_max_io_size(ub
);
1773 ret
= ublk_init_queues(ub
);
1775 goto out_free_dev_number
;
1777 ret
= ublk_add_tag_set(ub
);
1779 goto out_deinit_queues
;
1782 if (copy_to_user(argp
, &ub
->dev_info
, sizeof(info
)))
1783 goto out_free_tag_set
;
1786 * Add the char dev so that ublksrv daemon can be setup.
1787 * ublk_add_chdev() will cleanup everything if it fails.
1789 ret
= ublk_add_chdev(ub
);
1793 blk_mq_free_tag_set(&ub
->tag_set
);
1795 ublk_deinit_queues(ub
);
1796 out_free_dev_number
:
1797 ublk_free_dev_number(ub
);
1799 mutex_destroy(&ub
->mutex
);
1802 mutex_unlock(&ublk_ctl_mutex
);
1806 static inline bool ublk_idr_freed(int id
)
1810 spin_lock(&ublk_idr_lock
);
1811 ptr
= idr_find(&ublk_index_idr
, id
);
1812 spin_unlock(&ublk_idr_lock
);
1817 static int ublk_ctrl_del_dev(struct ublk_device
**p_ub
)
1819 struct ublk_device
*ub
= *p_ub
;
1820 int idx
= ub
->ub_number
;
1823 ret
= mutex_lock_killable(&ublk_ctl_mutex
);
1827 if (!test_bit(UB_STATE_DELETED
, &ub
->state
)) {
1829 set_bit(UB_STATE_DELETED
, &ub
->state
);
1832 /* Mark the reference as consumed */
1834 ublk_put_device(ub
);
1835 mutex_unlock(&ublk_ctl_mutex
);
1838 * Wait until the idr is removed, then it can be reused after
1839 * DEL_DEV command is returned.
1841 * If we returns because of user interrupt, future delete command
1844 * - the device number isn't freed, this device won't or needn't
1845 * be deleted again, since UB_STATE_DELETED is set, and device
1846 * will be released after the last reference is dropped
1848 * - the device number is freed already, we will not find this
1849 * device via ublk_get_device_from_id()
1851 wait_event_interruptible(ublk_idr_wq
, ublk_idr_freed(idx
));
1856 static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd
*cmd
)
1858 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1860 pr_devel("%s: cmd_op %x, dev id %d qid %d data %llx buf %llx len %u\n",
1861 __func__
, cmd
->cmd_op
, header
->dev_id
, header
->queue_id
,
1862 header
->data
[0], header
->addr
, header
->len
);
1865 static int ublk_ctrl_stop_dev(struct ublk_device
*ub
)
1868 cancel_work_sync(&ub
->stop_work
);
1869 cancel_work_sync(&ub
->quiesce_work
);
1874 static int ublk_ctrl_get_dev_info(struct ublk_device
*ub
,
1875 struct io_uring_cmd
*cmd
)
1877 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1878 void __user
*argp
= (void __user
*)(unsigned long)header
->addr
;
1880 if (header
->len
< sizeof(struct ublksrv_ctrl_dev_info
) || !header
->addr
)
1883 if (copy_to_user(argp
, &ub
->dev_info
, sizeof(ub
->dev_info
)))
1889 /* TYPE_DEVT is readonly, so fill it up before returning to userspace */
1890 static void ublk_ctrl_fill_params_devt(struct ublk_device
*ub
)
1892 ub
->params
.devt
.char_major
= MAJOR(ub
->cdev_dev
.devt
);
1893 ub
->params
.devt
.char_minor
= MINOR(ub
->cdev_dev
.devt
);
1896 ub
->params
.devt
.disk_major
= MAJOR(disk_devt(ub
->ub_disk
));
1897 ub
->params
.devt
.disk_minor
= MINOR(disk_devt(ub
->ub_disk
));
1899 ub
->params
.devt
.disk_major
= 0;
1900 ub
->params
.devt
.disk_minor
= 0;
1902 ub
->params
.types
|= UBLK_PARAM_TYPE_DEVT
;
1905 static int ublk_ctrl_get_params(struct ublk_device
*ub
,
1906 struct io_uring_cmd
*cmd
)
1908 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1909 void __user
*argp
= (void __user
*)(unsigned long)header
->addr
;
1910 struct ublk_params_header ph
;
1913 if (header
->len
<= sizeof(ph
) || !header
->addr
)
1916 if (copy_from_user(&ph
, argp
, sizeof(ph
)))
1919 if (ph
.len
> header
->len
|| !ph
.len
)
1922 if (ph
.len
> sizeof(struct ublk_params
))
1923 ph
.len
= sizeof(struct ublk_params
);
1925 mutex_lock(&ub
->mutex
);
1926 ublk_ctrl_fill_params_devt(ub
);
1927 if (copy_to_user(argp
, &ub
->params
, ph
.len
))
1931 mutex_unlock(&ub
->mutex
);
1936 static int ublk_ctrl_set_params(struct ublk_device
*ub
,
1937 struct io_uring_cmd
*cmd
)
1939 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1940 void __user
*argp
= (void __user
*)(unsigned long)header
->addr
;
1941 struct ublk_params_header ph
;
1944 if (header
->len
<= sizeof(ph
) || !header
->addr
)
1947 if (copy_from_user(&ph
, argp
, sizeof(ph
)))
1950 if (ph
.len
> header
->len
|| !ph
.len
|| !ph
.types
)
1953 if (ph
.len
> sizeof(struct ublk_params
))
1954 ph
.len
= sizeof(struct ublk_params
);
1956 /* parameters can only be changed when device isn't live */
1957 mutex_lock(&ub
->mutex
);
1958 if (ub
->dev_info
.state
== UBLK_S_DEV_LIVE
) {
1960 } else if (copy_from_user(&ub
->params
, argp
, ph
.len
)) {
1963 /* clear all we don't support yet */
1964 ub
->params
.types
&= UBLK_PARAM_TYPE_ALL
;
1965 ret
= ublk_validate_params(ub
);
1967 mutex_unlock(&ub
->mutex
);
1972 static void ublk_queue_reinit(struct ublk_device
*ub
, struct ublk_queue
*ubq
)
1976 WARN_ON_ONCE(!(ubq
->ubq_daemon
&& ubq_daemon_is_dying(ubq
)));
1977 /* All old ioucmds have to be completed */
1978 WARN_ON_ONCE(ubq
->nr_io_ready
);
1979 /* old daemon is PF_EXITING, put it now */
1980 put_task_struct(ubq
->ubq_daemon
);
1981 /* We have to reset it to NULL, otherwise ub won't accept new FETCH_REQ */
1982 ubq
->ubq_daemon
= NULL
;
1984 for (i
= 0; i
< ubq
->q_depth
; i
++) {
1985 struct ublk_io
*io
= &ubq
->ios
[i
];
1987 /* forget everything now and be ready for new FETCH_REQ */
1994 static int ublk_ctrl_start_recovery(struct ublk_device
*ub
,
1995 struct io_uring_cmd
*cmd
)
1997 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
2001 mutex_lock(&ub
->mutex
);
2002 if (!ublk_can_use_recovery(ub
))
2005 * START_RECOVERY is only allowd after:
2007 * (1) UB_STATE_OPEN is not set, which means the dying process is exited
2008 * and related io_uring ctx is freed so file struct of /dev/ublkcX is
2011 * (2) UBLK_S_DEV_QUIESCED is set, which means the quiesce_work:
2012 * (a)has quiesced request queue
2013 * (b)has requeued every inflight rqs whose io_flags is ACTIVE
2014 * (c)has requeued/aborted every inflight rqs whose io_flags is NOT ACTIVE
2015 * (d)has completed/camceled all ioucmds owned by ther dying process
2017 if (test_bit(UB_STATE_OPEN
, &ub
->state
) ||
2018 ub
->dev_info
.state
!= UBLK_S_DEV_QUIESCED
) {
2022 pr_devel("%s: start recovery for dev id %d.\n", __func__
, header
->dev_id
);
2023 for (i
= 0; i
< ub
->dev_info
.nr_hw_queues
; i
++)
2024 ublk_queue_reinit(ub
, ublk_get_queue(ub
, i
));
2025 /* set to NULL, otherwise new ubq_daemon cannot mmap the io_cmd_buf */
2027 ub
->nr_queues_ready
= 0;
2028 ub
->nr_privileged_daemon
= 0;
2029 init_completion(&ub
->completion
);
2032 mutex_unlock(&ub
->mutex
);
2036 static int ublk_ctrl_end_recovery(struct ublk_device
*ub
,
2037 struct io_uring_cmd
*cmd
)
2039 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
2040 int ublksrv_pid
= (int)header
->data
[0];
2043 pr_devel("%s: Waiting for new ubq_daemons(nr: %d) are ready, dev id %d...\n",
2044 __func__
, ub
->dev_info
.nr_hw_queues
, header
->dev_id
);
2045 /* wait until new ubq_daemon sending all FETCH_REQ */
2046 wait_for_completion_interruptible(&ub
->completion
);
2047 pr_devel("%s: All new ubq_daemons(nr: %d) are ready, dev id %d\n",
2048 __func__
, ub
->dev_info
.nr_hw_queues
, header
->dev_id
);
2050 mutex_lock(&ub
->mutex
);
2051 if (!ublk_can_use_recovery(ub
))
2054 if (ub
->dev_info
.state
!= UBLK_S_DEV_QUIESCED
) {
2058 ub
->dev_info
.ublksrv_pid
= ublksrv_pid
;
2059 pr_devel("%s: new ublksrv_pid %d, dev id %d\n",
2060 __func__
, ublksrv_pid
, header
->dev_id
);
2061 blk_mq_unquiesce_queue(ub
->ub_disk
->queue
);
2062 pr_devel("%s: queue unquiesced, dev id %d.\n",
2063 __func__
, header
->dev_id
);
2064 blk_mq_kick_requeue_list(ub
->ub_disk
->queue
);
2065 ub
->dev_info
.state
= UBLK_S_DEV_LIVE
;
2066 schedule_delayed_work(&ub
->monitor_work
, UBLK_DAEMON_MONITOR_PERIOD
);
2069 mutex_unlock(&ub
->mutex
);
2074 * All control commands are sent via /dev/ublk-control, so we have to check
2075 * the destination device's permission
2077 static int ublk_char_dev_permission(struct ublk_device
*ub
,
2078 const char *dev_path
, int mask
)
2084 err
= kern_path(dev_path
, LOOKUP_FOLLOW
, &path
);
2088 err
= vfs_getattr(&path
, &stat
, STATX_TYPE
, AT_STATX_SYNC_AS_STAT
);
2093 if (stat
.rdev
!= ub
->cdev_dev
.devt
|| !S_ISCHR(stat
.mode
))
2096 err
= inode_permission(&nop_mnt_idmap
,
2097 d_backing_inode(path
.dentry
), mask
);
2103 static int ublk_ctrl_uring_cmd_permission(struct ublk_device
*ub
,
2104 struct io_uring_cmd
*cmd
)
2106 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
2107 bool unprivileged
= ub
->dev_info
.flags
& UBLK_F_UNPRIVILEGED_DEV
;
2108 void __user
*argp
= (void __user
*)(unsigned long)header
->addr
;
2109 char *dev_path
= NULL
;
2113 if (!unprivileged
) {
2114 if (!capable(CAP_SYS_ADMIN
))
2117 * The new added command of UBLK_CMD_GET_DEV_INFO2 includes
2118 * char_dev_path in payload too, since userspace may not
2119 * know if the specified device is created as unprivileged
2122 if (_IOC_NR(cmd
->cmd_op
) != UBLK_CMD_GET_DEV_INFO2
)
2127 * User has to provide the char device path for unprivileged ublk
2129 * header->addr always points to the dev path buffer, and
2130 * header->dev_path_len records length of dev path buffer.
2132 if (!header
->dev_path_len
|| header
->dev_path_len
> PATH_MAX
)
2135 if (header
->len
< header
->dev_path_len
)
2138 dev_path
= kmalloc(header
->dev_path_len
+ 1, GFP_KERNEL
);
2143 if (copy_from_user(dev_path
, argp
, header
->dev_path_len
))
2145 dev_path
[header
->dev_path_len
] = 0;
2148 switch (_IOC_NR(cmd
->cmd_op
)) {
2149 case UBLK_CMD_GET_DEV_INFO
:
2150 case UBLK_CMD_GET_DEV_INFO2
:
2151 case UBLK_CMD_GET_QUEUE_AFFINITY
:
2152 case UBLK_CMD_GET_PARAMS
:
2155 case UBLK_CMD_START_DEV
:
2156 case UBLK_CMD_STOP_DEV
:
2157 case UBLK_CMD_ADD_DEV
:
2158 case UBLK_CMD_DEL_DEV
:
2159 case UBLK_CMD_SET_PARAMS
:
2160 case UBLK_CMD_START_USER_RECOVERY
:
2161 case UBLK_CMD_END_USER_RECOVERY
:
2162 mask
= MAY_READ
| MAY_WRITE
;
2168 ret
= ublk_char_dev_permission(ub
, dev_path
, mask
);
2170 header
->len
-= header
->dev_path_len
;
2171 header
->addr
+= header
->dev_path_len
;
2173 pr_devel("%s: dev id %d cmd_op %x uid %d gid %d path %s ret %d\n",
2174 __func__
, ub
->ub_number
, cmd
->cmd_op
,
2175 ub
->dev_info
.owner_uid
, ub
->dev_info
.owner_gid
,
2182 static int ublk_ctrl_uring_cmd(struct io_uring_cmd
*cmd
,
2183 unsigned int issue_flags
)
2185 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
2186 struct ublk_device
*ub
= NULL
;
2187 u32 cmd_op
= cmd
->cmd_op
;
2190 if (issue_flags
& IO_URING_F_NONBLOCK
)
2193 ublk_ctrl_cmd_dump(cmd
);
2195 if (!(issue_flags
& IO_URING_F_SQE128
))
2198 ret
= ublk_check_cmd_op(cmd_op
);
2202 if (_IOC_NR(cmd_op
) != UBLK_CMD_ADD_DEV
) {
2204 ub
= ublk_get_device_from_id(header
->dev_id
);
2208 ret
= ublk_ctrl_uring_cmd_permission(ub
, cmd
);
2213 switch (_IOC_NR(cmd_op
)) {
2214 case UBLK_CMD_START_DEV
:
2215 ret
= ublk_ctrl_start_dev(ub
, cmd
);
2217 case UBLK_CMD_STOP_DEV
:
2218 ret
= ublk_ctrl_stop_dev(ub
);
2220 case UBLK_CMD_GET_DEV_INFO
:
2221 case UBLK_CMD_GET_DEV_INFO2
:
2222 ret
= ublk_ctrl_get_dev_info(ub
, cmd
);
2224 case UBLK_CMD_ADD_DEV
:
2225 ret
= ublk_ctrl_add_dev(cmd
);
2227 case UBLK_CMD_DEL_DEV
:
2228 ret
= ublk_ctrl_del_dev(&ub
);
2230 case UBLK_CMD_GET_QUEUE_AFFINITY
:
2231 ret
= ublk_ctrl_get_queue_affinity(ub
, cmd
);
2233 case UBLK_CMD_GET_PARAMS
:
2234 ret
= ublk_ctrl_get_params(ub
, cmd
);
2236 case UBLK_CMD_SET_PARAMS
:
2237 ret
= ublk_ctrl_set_params(ub
, cmd
);
2239 case UBLK_CMD_START_USER_RECOVERY
:
2240 ret
= ublk_ctrl_start_recovery(ub
, cmd
);
2242 case UBLK_CMD_END_USER_RECOVERY
:
2243 ret
= ublk_ctrl_end_recovery(ub
, cmd
);
2252 ublk_put_device(ub
);
2254 io_uring_cmd_done(cmd
, ret
, 0);
2255 pr_devel("%s: cmd done ret %d cmd_op %x, dev id %d qid %d\n",
2256 __func__
, ret
, cmd
->cmd_op
, header
->dev_id
, header
->queue_id
);
2257 return -EIOCBQUEUED
;
2260 static const struct file_operations ublk_ctl_fops
= {
2261 .open
= nonseekable_open
,
2262 .uring_cmd
= ublk_ctrl_uring_cmd
,
2263 .owner
= THIS_MODULE
,
2264 .llseek
= noop_llseek
,
2267 static struct miscdevice ublk_misc
= {
2268 .minor
= MISC_DYNAMIC_MINOR
,
2269 .name
= "ublk-control",
2270 .fops
= &ublk_ctl_fops
,
2273 static int __init
ublk_init(void)
2277 init_waitqueue_head(&ublk_idr_wq
);
2279 ret
= misc_register(&ublk_misc
);
2283 ret
= alloc_chrdev_region(&ublk_chr_devt
, 0, UBLK_MINORS
, "ublk-char");
2285 goto unregister_mis
;
2287 ublk_chr_class
= class_create(THIS_MODULE
, "ublk-char");
2288 if (IS_ERR(ublk_chr_class
)) {
2289 ret
= PTR_ERR(ublk_chr_class
);
2290 goto free_chrdev_region
;
2295 unregister_chrdev_region(ublk_chr_devt
, UBLK_MINORS
);
2297 misc_deregister(&ublk_misc
);
2301 static void __exit
ublk_exit(void)
2303 struct ublk_device
*ub
;
2306 idr_for_each_entry(&ublk_index_idr
, ub
, id
)
2309 class_destroy(ublk_chr_class
);
2310 misc_deregister(&ublk_misc
);
2312 idr_destroy(&ublk_index_idr
);
2313 unregister_chrdev_region(ublk_chr_devt
, UBLK_MINORS
);
2316 module_init(ublk_init
);
2317 module_exit(ublk_exit
);
2319 module_param(ublks_max
, int, 0444);
2320 MODULE_PARM_DESC(ublks_max
, "max number of ublk devices allowed to add(default: 64)");
2322 MODULE_AUTHOR("Ming Lei <ming.lei@redhat.com>");
2323 MODULE_LICENSE("GPL");