1 // SPDX-License-Identifier: GPL-2.0
5 * Portions Copyright (C) 2020 Christoph Hellwig
8 #include <linux/module.h>
9 #include <linux/ctype.h>
11 #include <linux/genhd.h>
12 #include <linux/kdev_t.h>
13 #include <linux/kernel.h>
14 #include <linux/blkdev.h>
15 #include <linux/backing-dev.h>
16 #include <linux/init.h>
17 #include <linux/spinlock.h>
18 #include <linux/proc_fs.h>
19 #include <linux/seq_file.h>
20 #include <linux/slab.h>
21 #include <linux/kmod.h>
22 #include <linux/major.h>
23 #include <linux/mutex.h>
24 #include <linux/idr.h>
25 #include <linux/log2.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/badblocks.h>
30 #include "blk-rq-qos.h"
32 static struct kobject
*block_depr
;
35 * Unique, monotonically increasing sequential number associated with block
36 * devices instances (i.e. incremented each time a device is attached).
37 * Associating uevents with block devices in userspace is difficult and racy:
38 * the uevent netlink socket is lossy, and on slow and overloaded systems has
39 * a very high latency.
40 * Block devices do not have exclusive owners in userspace, any process can set
41 * one up (e.g. loop devices). Moreover, device names can be reused (e.g. loop0
42 * can be reused again and again).
43 * A userspace process setting up a block device and watching for its events
44 * cannot thus reliably tell whether an event relates to the device it just set
45 * up or another earlier instance with the same name.
46 * This sequential number allows userspace processes to solve this problem, and
47 * uniquely associate an uevent to the lifetime to a device.
49 static atomic64_t diskseq
;
51 /* for extended dynamic devt allocation, currently only one major is used */
52 #define NR_EXT_DEVT (1 << MINORBITS)
53 static DEFINE_IDA(ext_devt_ida
);
55 void set_capacity(struct gendisk
*disk
, sector_t sectors
)
57 struct block_device
*bdev
= disk
->part0
;
59 spin_lock(&bdev
->bd_size_lock
);
60 i_size_write(bdev
->bd_inode
, (loff_t
)sectors
<< SECTOR_SHIFT
);
61 spin_unlock(&bdev
->bd_size_lock
);
63 EXPORT_SYMBOL(set_capacity
);
66 * Set disk capacity and notify if the size is not currently zero and will not
67 * be set to zero. Returns true if a uevent was sent, otherwise false.
69 bool set_capacity_and_notify(struct gendisk
*disk
, sector_t size
)
71 sector_t capacity
= get_capacity(disk
);
72 char *envp
[] = { "RESIZE=1", NULL
};
74 set_capacity(disk
, size
);
77 * Only print a message and send a uevent if the gendisk is user visible
78 * and alive. This avoids spamming the log and udev when setting the
79 * initial capacity during probing.
81 if (size
== capacity
||
83 (disk
->flags
& GENHD_FL_HIDDEN
))
86 pr_info("%s: detected capacity change from %lld to %lld\n",
87 disk
->disk_name
, capacity
, size
);
90 * Historically we did not send a uevent for changes to/from an empty
93 if (!capacity
|| !size
)
95 kobject_uevent_env(&disk_to_dev(disk
)->kobj
, KOBJ_CHANGE
, envp
);
98 EXPORT_SYMBOL_GPL(set_capacity_and_notify
);
101 * Format the device name of the indicated block device into the supplied buffer
102 * and return a pointer to that same buffer for convenience.
104 * Note: do not use this in new code, use the %pg specifier to sprintf and
107 const char *bdevname(struct block_device
*bdev
, char *buf
)
109 struct gendisk
*hd
= bdev
->bd_disk
;
110 int partno
= bdev
->bd_partno
;
113 snprintf(buf
, BDEVNAME_SIZE
, "%s", hd
->disk_name
);
114 else if (isdigit(hd
->disk_name
[strlen(hd
->disk_name
)-1]))
115 snprintf(buf
, BDEVNAME_SIZE
, "%sp%d", hd
->disk_name
, partno
);
117 snprintf(buf
, BDEVNAME_SIZE
, "%s%d", hd
->disk_name
, partno
);
121 EXPORT_SYMBOL(bdevname
);
123 static void part_stat_read_all(struct block_device
*part
,
124 struct disk_stats
*stat
)
128 memset(stat
, 0, sizeof(struct disk_stats
));
129 for_each_possible_cpu(cpu
) {
130 struct disk_stats
*ptr
= per_cpu_ptr(part
->bd_stats
, cpu
);
133 for (group
= 0; group
< NR_STAT_GROUPS
; group
++) {
134 stat
->nsecs
[group
] += ptr
->nsecs
[group
];
135 stat
->sectors
[group
] += ptr
->sectors
[group
];
136 stat
->ios
[group
] += ptr
->ios
[group
];
137 stat
->merges
[group
] += ptr
->merges
[group
];
140 stat
->io_ticks
+= ptr
->io_ticks
;
144 static unsigned int part_in_flight(struct block_device
*part
)
146 unsigned int inflight
= 0;
149 for_each_possible_cpu(cpu
) {
150 inflight
+= part_stat_local_read_cpu(part
, in_flight
[0], cpu
) +
151 part_stat_local_read_cpu(part
, in_flight
[1], cpu
);
153 if ((int)inflight
< 0)
159 static void part_in_flight_rw(struct block_device
*part
,
160 unsigned int inflight
[2])
166 for_each_possible_cpu(cpu
) {
167 inflight
[0] += part_stat_local_read_cpu(part
, in_flight
[0], cpu
);
168 inflight
[1] += part_stat_local_read_cpu(part
, in_flight
[1], cpu
);
170 if ((int)inflight
[0] < 0)
172 if ((int)inflight
[1] < 0)
177 * Can be deleted altogether. Later.
180 #define BLKDEV_MAJOR_HASH_SIZE 255
181 static struct blk_major_name
{
182 struct blk_major_name
*next
;
185 void (*probe
)(dev_t devt
);
186 } *major_names
[BLKDEV_MAJOR_HASH_SIZE
];
187 static DEFINE_MUTEX(major_names_lock
);
188 static DEFINE_SPINLOCK(major_names_spinlock
);
190 /* index in the above - for now: assume no multimajor ranges */
191 static inline int major_to_index(unsigned major
)
193 return major
% BLKDEV_MAJOR_HASH_SIZE
;
196 #ifdef CONFIG_PROC_FS
197 void blkdev_show(struct seq_file
*seqf
, off_t offset
)
199 struct blk_major_name
*dp
;
201 spin_lock(&major_names_spinlock
);
202 for (dp
= major_names
[major_to_index(offset
)]; dp
; dp
= dp
->next
)
203 if (dp
->major
== offset
)
204 seq_printf(seqf
, "%3d %s\n", dp
->major
, dp
->name
);
205 spin_unlock(&major_names_spinlock
);
207 #endif /* CONFIG_PROC_FS */
210 * __register_blkdev - register a new block device
212 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
213 * @major = 0, try to allocate any unused major number.
214 * @name: the name of the new block device as a zero terminated string
215 * @probe: allback that is called on access to any minor number of @major
217 * The @name must be unique within the system.
219 * The return value depends on the @major input parameter:
221 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
222 * then the function returns zero on success, or a negative error code
223 * - if any unused major number was requested with @major = 0 parameter
224 * then the return value is the allocated major number in range
225 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
227 * See Documentation/admin-guide/devices.txt for the list of allocated
230 * Use register_blkdev instead for any new code.
232 int __register_blkdev(unsigned int major
, const char *name
,
233 void (*probe
)(dev_t devt
))
235 struct blk_major_name
**n
, *p
;
238 mutex_lock(&major_names_lock
);
242 for (index
= ARRAY_SIZE(major_names
)-1; index
> 0; index
--) {
243 if (major_names
[index
] == NULL
)
248 printk("%s: failed to get major for %s\n",
257 if (major
>= BLKDEV_MAJOR_MAX
) {
258 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
259 __func__
, major
, BLKDEV_MAJOR_MAX
-1, name
);
265 p
= kmalloc(sizeof(struct blk_major_name
), GFP_KERNEL
);
273 strlcpy(p
->name
, name
, sizeof(p
->name
));
275 index
= major_to_index(major
);
277 spin_lock(&major_names_spinlock
);
278 for (n
= &major_names
[index
]; *n
; n
= &(*n
)->next
) {
279 if ((*n
)->major
== major
)
286 spin_unlock(&major_names_spinlock
);
289 printk("register_blkdev: cannot get major %u for %s\n",
294 mutex_unlock(&major_names_lock
);
297 EXPORT_SYMBOL(__register_blkdev
);
299 void unregister_blkdev(unsigned int major
, const char *name
)
301 struct blk_major_name
**n
;
302 struct blk_major_name
*p
= NULL
;
303 int index
= major_to_index(major
);
305 mutex_lock(&major_names_lock
);
306 spin_lock(&major_names_spinlock
);
307 for (n
= &major_names
[index
]; *n
; n
= &(*n
)->next
)
308 if ((*n
)->major
== major
)
310 if (!*n
|| strcmp((*n
)->name
, name
)) {
316 spin_unlock(&major_names_spinlock
);
317 mutex_unlock(&major_names_lock
);
321 EXPORT_SYMBOL(unregister_blkdev
);
323 int blk_alloc_ext_minor(void)
327 idx
= ida_alloc_range(&ext_devt_ida
, 0, NR_EXT_DEVT
- 1, GFP_KERNEL
);
333 void blk_free_ext_minor(unsigned int minor
)
335 ida_free(&ext_devt_ida
, minor
);
338 static char *bdevt_str(dev_t devt
, char *buf
)
340 if (MAJOR(devt
) <= 0xff && MINOR(devt
) <= 0xff) {
341 char tbuf
[BDEVT_SIZE
];
342 snprintf(tbuf
, BDEVT_SIZE
, "%02x%02x", MAJOR(devt
), MINOR(devt
));
343 snprintf(buf
, BDEVT_SIZE
, "%-9s", tbuf
);
345 snprintf(buf
, BDEVT_SIZE
, "%03x:%05x", MAJOR(devt
), MINOR(devt
));
350 void disk_uevent(struct gendisk
*disk
, enum kobject_action action
)
352 struct block_device
*part
;
356 xa_for_each(&disk
->part_tbl
, idx
, part
) {
357 if (bdev_is_partition(part
) && !bdev_nr_sectors(part
))
359 if (!kobject_get_unless_zero(&part
->bd_device
.kobj
))
363 kobject_uevent(bdev_kobj(part
), action
);
364 put_device(&part
->bd_device
);
369 EXPORT_SYMBOL_GPL(disk_uevent
);
371 static void disk_scan_partitions(struct gendisk
*disk
)
373 struct block_device
*bdev
;
375 if (!get_capacity(disk
) || !disk_part_scan_enabled(disk
))
378 set_bit(GD_NEED_PART_SCAN
, &disk
->state
);
379 bdev
= blkdev_get_by_dev(disk_devt(disk
), FMODE_READ
, NULL
);
381 blkdev_put(bdev
, FMODE_READ
);
385 * device_add_disk - add disk information to kernel list
386 * @parent: parent device for the disk
387 * @disk: per-device partitioning information
388 * @groups: Additional per-device sysfs groups
390 * This function registers the partitioning information in @disk
393 int device_add_disk(struct device
*parent
, struct gendisk
*disk
,
394 const struct attribute_group
**groups
)
397 struct device
*ddev
= disk_to_dev(disk
);
401 * The disk queue should now be all set with enough information about
402 * the device for the elevator code to pick an adequate default
403 * elevator if one is needed, that is, for devices requesting queue
406 elevator_init_mq(disk
->queue
);
409 * If the driver provides an explicit major number it also must provide
410 * the number of minors numbers supported, and those will be used to
412 * Otherwise just allocate the device numbers for both the whole device
413 * and all partitions from the extended dev_t space.
416 if (WARN_ON(!disk
->minors
))
419 if (disk
->minors
> DISK_MAX_PARTS
) {
420 pr_err("block: can't allocate more than %d partitions\n",
422 disk
->minors
= DISK_MAX_PARTS
;
424 if (disk
->first_minor
+ disk
->minors
> MINORMASK
+ 1)
427 if (WARN_ON(disk
->minors
))
430 ret
= blk_alloc_ext_minor();
433 disk
->major
= BLOCK_EXT_MAJOR
;
434 disk
->first_minor
= ret
;
435 disk
->flags
|= GENHD_FL_EXT_DEVT
;
438 /* delay uevents, until we scanned partition table */
439 dev_set_uevent_suppress(ddev
, 1);
441 ddev
->parent
= parent
;
442 ddev
->groups
= groups
;
443 dev_set_name(ddev
, "%s", disk
->disk_name
);
444 if (!(disk
->flags
& GENHD_FL_HIDDEN
))
445 ddev
->devt
= MKDEV(disk
->major
, disk
->first_minor
);
446 ret
= device_add(ddev
);
448 goto out_free_ext_minor
;
450 ret
= disk_alloc_events(disk
);
454 if (!sysfs_deprecated
) {
455 ret
= sysfs_create_link(block_depr
, &ddev
->kobj
,
456 kobject_name(&ddev
->kobj
));
462 * avoid probable deadlock caused by allocating memory with
463 * GFP_KERNEL in runtime_resume callback of its all ancestor
466 pm_runtime_set_memalloc_noio(ddev
, true);
468 ret
= blk_integrity_add(disk
);
470 goto out_del_block_link
;
472 disk
->part0
->bd_holder_dir
=
473 kobject_create_and_add("holders", &ddev
->kobj
);
474 if (!disk
->part0
->bd_holder_dir
) {
476 goto out_del_integrity
;
478 disk
->slave_dir
= kobject_create_and_add("slaves", &ddev
->kobj
);
479 if (!disk
->slave_dir
) {
481 goto out_put_holder_dir
;
484 ret
= bd_register_pending_holders(disk
);
486 goto out_put_slave_dir
;
488 ret
= blk_register_queue(disk
);
490 goto out_put_slave_dir
;
492 if (disk
->flags
& GENHD_FL_HIDDEN
) {
494 * Don't let hidden disks show up in /proc/partitions,
495 * and don't bother scanning for partitions either.
497 disk
->flags
|= GENHD_FL_SUPPRESS_PARTITION_INFO
;
498 disk
->flags
|= GENHD_FL_NO_PART_SCAN
;
500 ret
= bdi_register(disk
->bdi
, "%u:%u",
501 disk
->major
, disk
->first_minor
);
503 goto out_unregister_queue
;
504 bdi_set_owner(disk
->bdi
, ddev
);
505 ret
= sysfs_create_link(&ddev
->kobj
,
506 &disk
->bdi
->dev
->kobj
, "bdi");
508 goto out_unregister_bdi
;
510 bdev_add(disk
->part0
, ddev
->devt
);
511 disk_scan_partitions(disk
);
514 * Announce the disk and partitions after all partitions are
515 * created. (for hidden disks uevents remain suppressed forever)
517 dev_set_uevent_suppress(ddev
, 0);
518 disk_uevent(disk
, KOBJ_ADD
);
521 disk_update_readahead(disk
);
522 disk_add_events(disk
);
526 if (!(disk
->flags
& GENHD_FL_HIDDEN
))
527 bdi_unregister(disk
->bdi
);
528 out_unregister_queue
:
529 blk_unregister_queue(disk
);
530 rq_qos_exit(disk
->queue
);
532 kobject_put(disk
->slave_dir
);
534 kobject_put(disk
->part0
->bd_holder_dir
);
536 blk_integrity_del(disk
);
538 if (!sysfs_deprecated
)
539 sysfs_remove_link(block_depr
, dev_name(ddev
));
543 if (disk
->major
== BLOCK_EXT_MAJOR
)
544 blk_free_ext_minor(disk
->first_minor
);
545 return WARN_ON_ONCE(ret
); /* keep until all callers handle errors */
547 EXPORT_SYMBOL(device_add_disk
);
550 * blk_mark_disk_dead - mark a disk as dead
551 * @disk: disk to mark as dead
553 * Mark as disk as dead (e.g. surprise removed) and don't accept any new I/O
556 void blk_mark_disk_dead(struct gendisk
*disk
)
558 set_bit(GD_DEAD
, &disk
->state
);
559 blk_queue_start_drain(disk
->queue
);
561 EXPORT_SYMBOL_GPL(blk_mark_disk_dead
);
564 * del_gendisk - remove the gendisk
565 * @disk: the struct gendisk to remove
567 * Removes the gendisk and all its associated resources. This deletes the
568 * partitions associated with the gendisk, and unregisters the associated
571 * This is the counter to the respective __device_add_disk() call.
573 * The final removal of the struct gendisk happens when its refcount reaches 0
574 * with put_disk(), which should be called after del_gendisk(), if
575 * __device_add_disk() was used.
577 * Drivers exist which depend on the release of the gendisk to be synchronous,
578 * it should not be deferred.
582 void del_gendisk(struct gendisk
*disk
)
584 struct request_queue
*q
= disk
->queue
;
588 if (WARN_ON_ONCE(!disk_live(disk
) && !(disk
->flags
& GENHD_FL_HIDDEN
)))
591 blk_integrity_del(disk
);
592 disk_del_events(disk
);
594 mutex_lock(&disk
->open_mutex
);
595 remove_inode_hash(disk
->part0
->bd_inode
);
596 blk_drop_partitions(disk
);
597 mutex_unlock(&disk
->open_mutex
);
599 fsync_bdev(disk
->part0
);
600 __invalidate_device(disk
->part0
, true);
605 set_bit(GD_DEAD
, &disk
->state
);
606 set_capacity(disk
, 0);
609 * Prevent new I/O from crossing bio_queue_enter().
611 blk_queue_start_drain(q
);
613 if (!(disk
->flags
& GENHD_FL_HIDDEN
)) {
614 sysfs_remove_link(&disk_to_dev(disk
)->kobj
, "bdi");
617 * Unregister bdi before releasing device numbers (as they can
618 * get reused and we'd get clashes in sysfs).
620 bdi_unregister(disk
->bdi
);
623 blk_unregister_queue(disk
);
625 kobject_put(disk
->part0
->bd_holder_dir
);
626 kobject_put(disk
->slave_dir
);
628 part_stat_set_all(disk
->part0
, 0);
629 disk
->part0
->bd_stamp
= 0;
630 if (!sysfs_deprecated
)
631 sysfs_remove_link(block_depr
, dev_name(disk_to_dev(disk
)));
632 pm_runtime_set_memalloc_noio(disk_to_dev(disk
), false);
633 device_del(disk_to_dev(disk
));
635 blk_mq_freeze_queue_wait(q
);
639 blk_flush_integrity();
641 * Allow using passthrough request again after the queue is torn down.
643 blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE
, q
);
644 __blk_mq_unfreeze_queue(q
, true);
647 EXPORT_SYMBOL(del_gendisk
);
649 /* sysfs access to bad-blocks list. */
650 static ssize_t
disk_badblocks_show(struct device
*dev
,
651 struct device_attribute
*attr
,
654 struct gendisk
*disk
= dev_to_disk(dev
);
657 return sprintf(page
, "\n");
659 return badblocks_show(disk
->bb
, page
, 0);
662 static ssize_t
disk_badblocks_store(struct device
*dev
,
663 struct device_attribute
*attr
,
664 const char *page
, size_t len
)
666 struct gendisk
*disk
= dev_to_disk(dev
);
671 return badblocks_store(disk
->bb
, page
, len
, 0);
674 void blk_request_module(dev_t devt
)
676 unsigned int major
= MAJOR(devt
);
677 struct blk_major_name
**n
;
679 mutex_lock(&major_names_lock
);
680 for (n
= &major_names
[major_to_index(major
)]; *n
; n
= &(*n
)->next
) {
681 if ((*n
)->major
== major
&& (*n
)->probe
) {
683 mutex_unlock(&major_names_lock
);
687 mutex_unlock(&major_names_lock
);
689 if (request_module("block-major-%d-%d", MAJOR(devt
), MINOR(devt
)) > 0)
690 /* Make old-style 2.4 aliases work */
691 request_module("block-major-%d", MAJOR(devt
));
695 * print a full list of all partitions - intended for places where the root
696 * filesystem can't be mounted and thus to give the victim some idea of what
699 void __init
printk_all_partitions(void)
701 struct class_dev_iter iter
;
704 class_dev_iter_init(&iter
, &block_class
, NULL
, &disk_type
);
705 while ((dev
= class_dev_iter_next(&iter
))) {
706 struct gendisk
*disk
= dev_to_disk(dev
);
707 struct block_device
*part
;
708 char devt_buf
[BDEVT_SIZE
];
712 * Don't show empty devices or things that have been
715 if (get_capacity(disk
) == 0 ||
716 (disk
->flags
& GENHD_FL_SUPPRESS_PARTITION_INFO
))
720 * Note, unlike /proc/partitions, I am showing the numbers in
721 * hex - the same format as the root= option takes.
724 xa_for_each(&disk
->part_tbl
, idx
, part
) {
725 if (!bdev_nr_sectors(part
))
727 printk("%s%s %10llu %pg %s",
728 bdev_is_partition(part
) ? " " : "",
729 bdevt_str(part
->bd_dev
, devt_buf
),
730 bdev_nr_sectors(part
) >> 1, part
,
732 part
->bd_meta_info
->uuid
: "");
733 if (bdev_is_partition(part
))
735 else if (dev
->parent
&& dev
->parent
->driver
)
736 printk(" driver: %s\n",
737 dev
->parent
->driver
->name
);
739 printk(" (driver?)\n");
743 class_dev_iter_exit(&iter
);
746 #ifdef CONFIG_PROC_FS
748 static void *disk_seqf_start(struct seq_file
*seqf
, loff_t
*pos
)
751 struct class_dev_iter
*iter
;
754 iter
= kmalloc(sizeof(*iter
), GFP_KERNEL
);
756 return ERR_PTR(-ENOMEM
);
758 seqf
->private = iter
;
759 class_dev_iter_init(iter
, &block_class
, NULL
, &disk_type
);
761 dev
= class_dev_iter_next(iter
);
766 return dev_to_disk(dev
);
769 static void *disk_seqf_next(struct seq_file
*seqf
, void *v
, loff_t
*pos
)
774 dev
= class_dev_iter_next(seqf
->private);
776 return dev_to_disk(dev
);
781 static void disk_seqf_stop(struct seq_file
*seqf
, void *v
)
783 struct class_dev_iter
*iter
= seqf
->private;
785 /* stop is called even after start failed :-( */
787 class_dev_iter_exit(iter
);
789 seqf
->private = NULL
;
793 static void *show_partition_start(struct seq_file
*seqf
, loff_t
*pos
)
797 p
= disk_seqf_start(seqf
, pos
);
798 if (!IS_ERR_OR_NULL(p
) && !*pos
)
799 seq_puts(seqf
, "major minor #blocks name\n\n");
803 static int show_partition(struct seq_file
*seqf
, void *v
)
805 struct gendisk
*sgp
= v
;
806 struct block_device
*part
;
809 /* Don't show non-partitionable removeable devices or empty devices */
810 if (!get_capacity(sgp
) || (!disk_max_parts(sgp
) &&
811 (sgp
->flags
& GENHD_FL_REMOVABLE
)))
813 if (sgp
->flags
& GENHD_FL_SUPPRESS_PARTITION_INFO
)
817 xa_for_each(&sgp
->part_tbl
, idx
, part
) {
818 if (!bdev_nr_sectors(part
))
820 seq_printf(seqf
, "%4d %7d %10llu %pg\n",
821 MAJOR(part
->bd_dev
), MINOR(part
->bd_dev
),
822 bdev_nr_sectors(part
) >> 1, part
);
828 static const struct seq_operations partitions_op
= {
829 .start
= show_partition_start
,
830 .next
= disk_seqf_next
,
831 .stop
= disk_seqf_stop
,
832 .show
= show_partition
836 static int __init
genhd_device_init(void)
840 block_class
.dev_kobj
= sysfs_dev_block_kobj
;
841 error
= class_register(&block_class
);
846 register_blkdev(BLOCK_EXT_MAJOR
, "blkext");
848 /* create top-level block dir */
849 if (!sysfs_deprecated
)
850 block_depr
= kobject_create_and_add("block", NULL
);
854 subsys_initcall(genhd_device_init
);
856 static ssize_t
disk_range_show(struct device
*dev
,
857 struct device_attribute
*attr
, char *buf
)
859 struct gendisk
*disk
= dev_to_disk(dev
);
861 return sprintf(buf
, "%d\n", disk
->minors
);
864 static ssize_t
disk_ext_range_show(struct device
*dev
,
865 struct device_attribute
*attr
, char *buf
)
867 struct gendisk
*disk
= dev_to_disk(dev
);
869 return sprintf(buf
, "%d\n", disk_max_parts(disk
));
872 static ssize_t
disk_removable_show(struct device
*dev
,
873 struct device_attribute
*attr
, char *buf
)
875 struct gendisk
*disk
= dev_to_disk(dev
);
877 return sprintf(buf
, "%d\n",
878 (disk
->flags
& GENHD_FL_REMOVABLE
? 1 : 0));
881 static ssize_t
disk_hidden_show(struct device
*dev
,
882 struct device_attribute
*attr
, char *buf
)
884 struct gendisk
*disk
= dev_to_disk(dev
);
886 return sprintf(buf
, "%d\n",
887 (disk
->flags
& GENHD_FL_HIDDEN
? 1 : 0));
890 static ssize_t
disk_ro_show(struct device
*dev
,
891 struct device_attribute
*attr
, char *buf
)
893 struct gendisk
*disk
= dev_to_disk(dev
);
895 return sprintf(buf
, "%d\n", get_disk_ro(disk
) ? 1 : 0);
898 ssize_t
part_size_show(struct device
*dev
,
899 struct device_attribute
*attr
, char *buf
)
901 return sprintf(buf
, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev
)));
904 ssize_t
part_stat_show(struct device
*dev
,
905 struct device_attribute
*attr
, char *buf
)
907 struct block_device
*bdev
= dev_to_bdev(dev
);
908 struct request_queue
*q
= bdev
->bd_disk
->queue
;
909 struct disk_stats stat
;
910 unsigned int inflight
;
912 part_stat_read_all(bdev
, &stat
);
914 inflight
= blk_mq_in_flight(q
, bdev
);
916 inflight
= part_in_flight(bdev
);
919 "%8lu %8lu %8llu %8u "
920 "%8lu %8lu %8llu %8u "
922 "%8lu %8lu %8llu %8u "
926 stat
.merges
[STAT_READ
],
927 (unsigned long long)stat
.sectors
[STAT_READ
],
928 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
], NSEC_PER_MSEC
),
929 stat
.ios
[STAT_WRITE
],
930 stat
.merges
[STAT_WRITE
],
931 (unsigned long long)stat
.sectors
[STAT_WRITE
],
932 (unsigned int)div_u64(stat
.nsecs
[STAT_WRITE
], NSEC_PER_MSEC
),
934 jiffies_to_msecs(stat
.io_ticks
),
935 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
] +
936 stat
.nsecs
[STAT_WRITE
] +
937 stat
.nsecs
[STAT_DISCARD
] +
938 stat
.nsecs
[STAT_FLUSH
],
940 stat
.ios
[STAT_DISCARD
],
941 stat
.merges
[STAT_DISCARD
],
942 (unsigned long long)stat
.sectors
[STAT_DISCARD
],
943 (unsigned int)div_u64(stat
.nsecs
[STAT_DISCARD
], NSEC_PER_MSEC
),
944 stat
.ios
[STAT_FLUSH
],
945 (unsigned int)div_u64(stat
.nsecs
[STAT_FLUSH
], NSEC_PER_MSEC
));
948 ssize_t
part_inflight_show(struct device
*dev
, struct device_attribute
*attr
,
951 struct block_device
*bdev
= dev_to_bdev(dev
);
952 struct request_queue
*q
= bdev
->bd_disk
->queue
;
953 unsigned int inflight
[2];
956 blk_mq_in_flight_rw(q
, bdev
, inflight
);
958 part_in_flight_rw(bdev
, inflight
);
960 return sprintf(buf
, "%8u %8u\n", inflight
[0], inflight
[1]);
963 static ssize_t
disk_capability_show(struct device
*dev
,
964 struct device_attribute
*attr
, char *buf
)
966 struct gendisk
*disk
= dev_to_disk(dev
);
968 return sprintf(buf
, "%x\n", disk
->flags
);
971 static ssize_t
disk_alignment_offset_show(struct device
*dev
,
972 struct device_attribute
*attr
,
975 struct gendisk
*disk
= dev_to_disk(dev
);
977 return sprintf(buf
, "%d\n", queue_alignment_offset(disk
->queue
));
980 static ssize_t
disk_discard_alignment_show(struct device
*dev
,
981 struct device_attribute
*attr
,
984 struct gendisk
*disk
= dev_to_disk(dev
);
986 return sprintf(buf
, "%d\n", queue_discard_alignment(disk
->queue
));
989 static ssize_t
diskseq_show(struct device
*dev
,
990 struct device_attribute
*attr
, char *buf
)
992 struct gendisk
*disk
= dev_to_disk(dev
);
994 return sprintf(buf
, "%llu\n", disk
->diskseq
);
997 static DEVICE_ATTR(range
, 0444, disk_range_show
, NULL
);
998 static DEVICE_ATTR(ext_range
, 0444, disk_ext_range_show
, NULL
);
999 static DEVICE_ATTR(removable
, 0444, disk_removable_show
, NULL
);
1000 static DEVICE_ATTR(hidden
, 0444, disk_hidden_show
, NULL
);
1001 static DEVICE_ATTR(ro
, 0444, disk_ro_show
, NULL
);
1002 static DEVICE_ATTR(size
, 0444, part_size_show
, NULL
);
1003 static DEVICE_ATTR(alignment_offset
, 0444, disk_alignment_offset_show
, NULL
);
1004 static DEVICE_ATTR(discard_alignment
, 0444, disk_discard_alignment_show
, NULL
);
1005 static DEVICE_ATTR(capability
, 0444, disk_capability_show
, NULL
);
1006 static DEVICE_ATTR(stat
, 0444, part_stat_show
, NULL
);
1007 static DEVICE_ATTR(inflight
, 0444, part_inflight_show
, NULL
);
1008 static DEVICE_ATTR(badblocks
, 0644, disk_badblocks_show
, disk_badblocks_store
);
1009 static DEVICE_ATTR(diskseq
, 0444, diskseq_show
, NULL
);
1011 #ifdef CONFIG_FAIL_MAKE_REQUEST
1012 ssize_t
part_fail_show(struct device
*dev
,
1013 struct device_attribute
*attr
, char *buf
)
1015 return sprintf(buf
, "%d\n", dev_to_bdev(dev
)->bd_make_it_fail
);
1018 ssize_t
part_fail_store(struct device
*dev
,
1019 struct device_attribute
*attr
,
1020 const char *buf
, size_t count
)
1024 if (count
> 0 && sscanf(buf
, "%d", &i
) > 0)
1025 dev_to_bdev(dev
)->bd_make_it_fail
= i
;
1030 static struct device_attribute dev_attr_fail
=
1031 __ATTR(make
-it
-fail
, 0644, part_fail_show
, part_fail_store
);
1032 #endif /* CONFIG_FAIL_MAKE_REQUEST */
1034 #ifdef CONFIG_FAIL_IO_TIMEOUT
1035 static struct device_attribute dev_attr_fail_timeout
=
1036 __ATTR(io
-timeout
-fail
, 0644, part_timeout_show
, part_timeout_store
);
1039 static struct attribute
*disk_attrs
[] = {
1040 &dev_attr_range
.attr
,
1041 &dev_attr_ext_range
.attr
,
1042 &dev_attr_removable
.attr
,
1043 &dev_attr_hidden
.attr
,
1045 &dev_attr_size
.attr
,
1046 &dev_attr_alignment_offset
.attr
,
1047 &dev_attr_discard_alignment
.attr
,
1048 &dev_attr_capability
.attr
,
1049 &dev_attr_stat
.attr
,
1050 &dev_attr_inflight
.attr
,
1051 &dev_attr_badblocks
.attr
,
1052 &dev_attr_events
.attr
,
1053 &dev_attr_events_async
.attr
,
1054 &dev_attr_events_poll_msecs
.attr
,
1055 &dev_attr_diskseq
.attr
,
1056 #ifdef CONFIG_FAIL_MAKE_REQUEST
1057 &dev_attr_fail
.attr
,
1059 #ifdef CONFIG_FAIL_IO_TIMEOUT
1060 &dev_attr_fail_timeout
.attr
,
1065 static umode_t
disk_visible(struct kobject
*kobj
, struct attribute
*a
, int n
)
1067 struct device
*dev
= container_of(kobj
, typeof(*dev
), kobj
);
1068 struct gendisk
*disk
= dev_to_disk(dev
);
1070 if (a
== &dev_attr_badblocks
.attr
&& !disk
->bb
)
1075 static struct attribute_group disk_attr_group
= {
1076 .attrs
= disk_attrs
,
1077 .is_visible
= disk_visible
,
1080 static const struct attribute_group
*disk_attr_groups
[] = {
1086 * disk_release - releases all allocated resources of the gendisk
1087 * @dev: the device representing this disk
1089 * This function releases all allocated resources of the gendisk.
1091 * Drivers which used __device_add_disk() have a gendisk with a request_queue
1092 * assigned. Since the request_queue sits on top of the gendisk for these
1093 * drivers we also call blk_put_queue() for them, and we expect the
1094 * request_queue refcount to reach 0 at this point, and so the request_queue
1095 * will also be freed prior to the disk.
1097 * Context: can sleep
1099 static void disk_release(struct device
*dev
)
1101 struct gendisk
*disk
= dev_to_disk(dev
);
1104 WARN_ON_ONCE(disk_live(disk
));
1106 blk_mq_cancel_work_sync(disk
->queue
);
1108 disk_release_events(disk
);
1109 kfree(disk
->random
);
1110 xa_destroy(&disk
->part_tbl
);
1111 disk
->queue
->disk
= NULL
;
1112 blk_put_queue(disk
->queue
);
1113 iput(disk
->part0
->bd_inode
); /* frees the disk */
1116 static int block_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
1118 struct gendisk
*disk
= dev_to_disk(dev
);
1120 return add_uevent_var(env
, "DISKSEQ=%llu", disk
->diskseq
);
1123 struct class block_class
= {
1125 .dev_uevent
= block_uevent
,
1128 static char *block_devnode(struct device
*dev
, umode_t
*mode
,
1129 kuid_t
*uid
, kgid_t
*gid
)
1131 struct gendisk
*disk
= dev_to_disk(dev
);
1133 if (disk
->fops
->devnode
)
1134 return disk
->fops
->devnode(disk
, mode
);
1138 const struct device_type disk_type
= {
1140 .groups
= disk_attr_groups
,
1141 .release
= disk_release
,
1142 .devnode
= block_devnode
,
1145 #ifdef CONFIG_PROC_FS
1147 * aggregate disk stat collector. Uses the same stats that the sysfs
1148 * entries do, above, but makes them available through one seq_file.
1150 * The output looks suspiciously like /proc/partitions with a bunch of
1153 static int diskstats_show(struct seq_file
*seqf
, void *v
)
1155 struct gendisk
*gp
= v
;
1156 struct block_device
*hd
;
1157 unsigned int inflight
;
1158 struct disk_stats stat
;
1162 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1163 seq_puts(seqf, "major minor name"
1164 " rio rmerge rsect ruse wio wmerge "
1165 "wsect wuse running use aveq"
1170 xa_for_each(&gp
->part_tbl
, idx
, hd
) {
1171 if (bdev_is_partition(hd
) && !bdev_nr_sectors(hd
))
1173 part_stat_read_all(hd
, &stat
);
1174 if (queue_is_mq(gp
->queue
))
1175 inflight
= blk_mq_in_flight(gp
->queue
, hd
);
1177 inflight
= part_in_flight(hd
);
1179 seq_printf(seqf
, "%4d %7d %pg "
1186 MAJOR(hd
->bd_dev
), MINOR(hd
->bd_dev
), hd
,
1187 stat
.ios
[STAT_READ
],
1188 stat
.merges
[STAT_READ
],
1189 stat
.sectors
[STAT_READ
],
1190 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
],
1192 stat
.ios
[STAT_WRITE
],
1193 stat
.merges
[STAT_WRITE
],
1194 stat
.sectors
[STAT_WRITE
],
1195 (unsigned int)div_u64(stat
.nsecs
[STAT_WRITE
],
1198 jiffies_to_msecs(stat
.io_ticks
),
1199 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
] +
1200 stat
.nsecs
[STAT_WRITE
] +
1201 stat
.nsecs
[STAT_DISCARD
] +
1202 stat
.nsecs
[STAT_FLUSH
],
1204 stat
.ios
[STAT_DISCARD
],
1205 stat
.merges
[STAT_DISCARD
],
1206 stat
.sectors
[STAT_DISCARD
],
1207 (unsigned int)div_u64(stat
.nsecs
[STAT_DISCARD
],
1209 stat
.ios
[STAT_FLUSH
],
1210 (unsigned int)div_u64(stat
.nsecs
[STAT_FLUSH
],
1219 static const struct seq_operations diskstats_op
= {
1220 .start
= disk_seqf_start
,
1221 .next
= disk_seqf_next
,
1222 .stop
= disk_seqf_stop
,
1223 .show
= diskstats_show
1226 static int __init
proc_genhd_init(void)
1228 proc_create_seq("diskstats", 0, NULL
, &diskstats_op
);
1229 proc_create_seq("partitions", 0, NULL
, &partitions_op
);
1232 module_init(proc_genhd_init
);
1233 #endif /* CONFIG_PROC_FS */
1235 dev_t
part_devt(struct gendisk
*disk
, u8 partno
)
1237 struct block_device
*part
;
1241 part
= xa_load(&disk
->part_tbl
, partno
);
1243 devt
= part
->bd_dev
;
1249 dev_t
blk_lookup_devt(const char *name
, int partno
)
1251 dev_t devt
= MKDEV(0, 0);
1252 struct class_dev_iter iter
;
1255 class_dev_iter_init(&iter
, &block_class
, NULL
, &disk_type
);
1256 while ((dev
= class_dev_iter_next(&iter
))) {
1257 struct gendisk
*disk
= dev_to_disk(dev
);
1259 if (strcmp(dev_name(dev
), name
))
1262 if (partno
< disk
->minors
) {
1263 /* We need to return the right devno, even
1264 * if the partition doesn't exist yet.
1266 devt
= MKDEV(MAJOR(dev
->devt
),
1267 MINOR(dev
->devt
) + partno
);
1269 devt
= part_devt(disk
, partno
);
1274 class_dev_iter_exit(&iter
);
1278 struct gendisk
*__alloc_disk_node(struct request_queue
*q
, int node_id
,
1279 struct lock_class_key
*lkclass
)
1281 struct gendisk
*disk
;
1283 if (!blk_get_queue(q
))
1286 disk
= kzalloc_node(sizeof(struct gendisk
), GFP_KERNEL
, node_id
);
1290 disk
->bdi
= bdi_alloc(node_id
);
1294 disk
->part0
= bdev_alloc(disk
, 0);
1298 disk
->node_id
= node_id
;
1299 mutex_init(&disk
->open_mutex
);
1300 xa_init(&disk
->part_tbl
);
1301 if (xa_insert(&disk
->part_tbl
, 0, disk
->part0
, GFP_KERNEL
))
1302 goto out_destroy_part_tbl
;
1304 rand_initialize_disk(disk
);
1305 disk_to_dev(disk
)->class = &block_class
;
1306 disk_to_dev(disk
)->type
= &disk_type
;
1307 device_initialize(disk_to_dev(disk
));
1311 lockdep_init_map(&disk
->lockdep_map
, "(bio completion)", lkclass
, 0);
1312 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
1313 INIT_LIST_HEAD(&disk
->slave_bdevs
);
1317 out_destroy_part_tbl
:
1318 xa_destroy(&disk
->part_tbl
);
1319 disk
->part0
->bd_disk
= NULL
;
1320 iput(disk
->part0
->bd_inode
);
1329 EXPORT_SYMBOL(__alloc_disk_node
);
1331 struct gendisk
*__blk_alloc_disk(int node
, struct lock_class_key
*lkclass
)
1333 struct request_queue
*q
;
1334 struct gendisk
*disk
;
1336 q
= blk_alloc_queue(node
);
1340 disk
= __alloc_disk_node(q
, node
, lkclass
);
1342 blk_cleanup_queue(q
);
1347 EXPORT_SYMBOL(__blk_alloc_disk
);
1350 * put_disk - decrements the gendisk refcount
1351 * @disk: the struct gendisk to decrement the refcount for
1353 * This decrements the refcount for the struct gendisk. When this reaches 0
1354 * we'll have disk_release() called.
1356 * Context: Any context, but the last reference must not be dropped from
1359 void put_disk(struct gendisk
*disk
)
1362 put_device(disk_to_dev(disk
));
1364 EXPORT_SYMBOL(put_disk
);
1367 * blk_cleanup_disk - shutdown a gendisk allocated by blk_alloc_disk
1368 * @disk: gendisk to shutdown
1370 * Mark the queue hanging off @disk DYING, drain all pending requests, then mark
1371 * the queue DEAD, destroy and put it and the gendisk structure.
1373 * Context: can sleep
1375 void blk_cleanup_disk(struct gendisk
*disk
)
1377 blk_cleanup_queue(disk
->queue
);
1380 EXPORT_SYMBOL(blk_cleanup_disk
);
1382 static void set_disk_ro_uevent(struct gendisk
*gd
, int ro
)
1384 char event
[] = "DISK_RO=1";
1385 char *envp
[] = { event
, NULL
};
1389 kobject_uevent_env(&disk_to_dev(gd
)->kobj
, KOBJ_CHANGE
, envp
);
1393 * set_disk_ro - set a gendisk read-only
1394 * @disk: gendisk to operate on
1395 * @read_only: %true to set the disk read-only, %false set the disk read/write
1397 * This function is used to indicate whether a given disk device should have its
1398 * read-only flag set. set_disk_ro() is typically used by device drivers to
1399 * indicate whether the underlying physical device is write-protected.
1401 void set_disk_ro(struct gendisk
*disk
, bool read_only
)
1404 if (test_and_set_bit(GD_READ_ONLY
, &disk
->state
))
1407 if (!test_and_clear_bit(GD_READ_ONLY
, &disk
->state
))
1410 set_disk_ro_uevent(disk
, read_only
);
1412 EXPORT_SYMBOL(set_disk_ro
);
1414 int bdev_read_only(struct block_device
*bdev
)
1416 return bdev
->bd_read_only
|| get_disk_ro(bdev
->bd_disk
);
1418 EXPORT_SYMBOL(bdev_read_only
);
1420 void inc_diskseq(struct gendisk
*disk
)
1422 disk
->diskseq
= atomic64_inc_return(&diskseq
);