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/mutex.h>
23 #include <linux/idr.h>
24 #include <linux/log2.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/badblocks.h>
29 #include "blk-rq-qos.h"
31 static struct kobject
*block_depr
;
34 * Unique, monotonically increasing sequential number associated with block
35 * devices instances (i.e. incremented each time a device is attached).
36 * Associating uevents with block devices in userspace is difficult and racy:
37 * the uevent netlink socket is lossy, and on slow and overloaded systems has
38 * a very high latency.
39 * Block devices do not have exclusive owners in userspace, any process can set
40 * one up (e.g. loop devices). Moreover, device names can be reused (e.g. loop0
41 * can be reused again and again).
42 * A userspace process setting up a block device and watching for its events
43 * cannot thus reliably tell whether an event relates to the device it just set
44 * up or another earlier instance with the same name.
45 * This sequential number allows userspace processes to solve this problem, and
46 * uniquely associate an uevent to the lifetime to a device.
48 static atomic64_t diskseq
;
50 /* for extended dynamic devt allocation, currently only one major is used */
51 #define NR_EXT_DEVT (1 << MINORBITS)
52 static DEFINE_IDA(ext_devt_ida
);
54 void set_capacity(struct gendisk
*disk
, sector_t sectors
)
56 struct block_device
*bdev
= disk
->part0
;
58 spin_lock(&bdev
->bd_size_lock
);
59 i_size_write(bdev
->bd_inode
, (loff_t
)sectors
<< SECTOR_SHIFT
);
60 spin_unlock(&bdev
->bd_size_lock
);
62 EXPORT_SYMBOL(set_capacity
);
65 * Set disk capacity and notify if the size is not currently zero and will not
66 * be set to zero. Returns true if a uevent was sent, otherwise false.
68 bool set_capacity_and_notify(struct gendisk
*disk
, sector_t size
)
70 sector_t capacity
= get_capacity(disk
);
71 char *envp
[] = { "RESIZE=1", NULL
};
73 set_capacity(disk
, size
);
76 * Only print a message and send a uevent if the gendisk is user visible
77 * and alive. This avoids spamming the log and udev when setting the
78 * initial capacity during probing.
80 if (size
== capacity
||
82 (disk
->flags
& GENHD_FL_HIDDEN
))
85 pr_info("%s: detected capacity change from %lld to %lld\n",
86 disk
->disk_name
, capacity
, size
);
89 * Historically we did not send a uevent for changes to/from an empty
92 if (!capacity
|| !size
)
94 kobject_uevent_env(&disk_to_dev(disk
)->kobj
, KOBJ_CHANGE
, envp
);
97 EXPORT_SYMBOL_GPL(set_capacity_and_notify
);
100 * Format the device name of the indicated block device into the supplied buffer
101 * and return a pointer to that same buffer for convenience.
103 * Note: do not use this in new code, use the %pg specifier to sprintf and
106 const char *bdevname(struct block_device
*bdev
, char *buf
)
108 struct gendisk
*hd
= bdev
->bd_disk
;
109 int partno
= bdev
->bd_partno
;
112 snprintf(buf
, BDEVNAME_SIZE
, "%s", hd
->disk_name
);
113 else if (isdigit(hd
->disk_name
[strlen(hd
->disk_name
)-1]))
114 snprintf(buf
, BDEVNAME_SIZE
, "%sp%d", hd
->disk_name
, partno
);
116 snprintf(buf
, BDEVNAME_SIZE
, "%s%d", hd
->disk_name
, partno
);
120 EXPORT_SYMBOL(bdevname
);
122 static void part_stat_read_all(struct block_device
*part
,
123 struct disk_stats
*stat
)
127 memset(stat
, 0, sizeof(struct disk_stats
));
128 for_each_possible_cpu(cpu
) {
129 struct disk_stats
*ptr
= per_cpu_ptr(part
->bd_stats
, cpu
);
132 for (group
= 0; group
< NR_STAT_GROUPS
; group
++) {
133 stat
->nsecs
[group
] += ptr
->nsecs
[group
];
134 stat
->sectors
[group
] += ptr
->sectors
[group
];
135 stat
->ios
[group
] += ptr
->ios
[group
];
136 stat
->merges
[group
] += ptr
->merges
[group
];
139 stat
->io_ticks
+= ptr
->io_ticks
;
143 static unsigned int part_in_flight(struct block_device
*part
)
145 unsigned int inflight
= 0;
148 for_each_possible_cpu(cpu
) {
149 inflight
+= part_stat_local_read_cpu(part
, in_flight
[0], cpu
) +
150 part_stat_local_read_cpu(part
, in_flight
[1], cpu
);
152 if ((int)inflight
< 0)
158 static void part_in_flight_rw(struct block_device
*part
,
159 unsigned int inflight
[2])
165 for_each_possible_cpu(cpu
) {
166 inflight
[0] += part_stat_local_read_cpu(part
, in_flight
[0], cpu
);
167 inflight
[1] += part_stat_local_read_cpu(part
, in_flight
[1], cpu
);
169 if ((int)inflight
[0] < 0)
171 if ((int)inflight
[1] < 0)
176 * Can be deleted altogether. Later.
179 #define BLKDEV_MAJOR_HASH_SIZE 255
180 static struct blk_major_name
{
181 struct blk_major_name
*next
;
184 void (*probe
)(dev_t devt
);
185 } *major_names
[BLKDEV_MAJOR_HASH_SIZE
];
186 static DEFINE_MUTEX(major_names_lock
);
187 static DEFINE_SPINLOCK(major_names_spinlock
);
189 /* index in the above - for now: assume no multimajor ranges */
190 static inline int major_to_index(unsigned major
)
192 return major
% BLKDEV_MAJOR_HASH_SIZE
;
195 #ifdef CONFIG_PROC_FS
196 void blkdev_show(struct seq_file
*seqf
, off_t offset
)
198 struct blk_major_name
*dp
;
200 spin_lock(&major_names_spinlock
);
201 for (dp
= major_names
[major_to_index(offset
)]; dp
; dp
= dp
->next
)
202 if (dp
->major
== offset
)
203 seq_printf(seqf
, "%3d %s\n", dp
->major
, dp
->name
);
204 spin_unlock(&major_names_spinlock
);
206 #endif /* CONFIG_PROC_FS */
209 * __register_blkdev - register a new block device
211 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
212 * @major = 0, try to allocate any unused major number.
213 * @name: the name of the new block device as a zero terminated string
214 * @probe: allback that is called on access to any minor number of @major
216 * The @name must be unique within the system.
218 * The return value depends on the @major input parameter:
220 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
221 * then the function returns zero on success, or a negative error code
222 * - if any unused major number was requested with @major = 0 parameter
223 * then the return value is the allocated major number in range
224 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
226 * See Documentation/admin-guide/devices.txt for the list of allocated
229 * Use register_blkdev instead for any new code.
231 int __register_blkdev(unsigned int major
, const char *name
,
232 void (*probe
)(dev_t devt
))
234 struct blk_major_name
**n
, *p
;
237 mutex_lock(&major_names_lock
);
241 for (index
= ARRAY_SIZE(major_names
)-1; index
> 0; index
--) {
242 if (major_names
[index
] == NULL
)
247 printk("%s: failed to get major for %s\n",
256 if (major
>= BLKDEV_MAJOR_MAX
) {
257 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
258 __func__
, major
, BLKDEV_MAJOR_MAX
-1, name
);
264 p
= kmalloc(sizeof(struct blk_major_name
), GFP_KERNEL
);
272 strlcpy(p
->name
, name
, sizeof(p
->name
));
274 index
= major_to_index(major
);
276 spin_lock(&major_names_spinlock
);
277 for (n
= &major_names
[index
]; *n
; n
= &(*n
)->next
) {
278 if ((*n
)->major
== major
)
285 spin_unlock(&major_names_spinlock
);
288 printk("register_blkdev: cannot get major %u for %s\n",
293 mutex_unlock(&major_names_lock
);
296 EXPORT_SYMBOL(__register_blkdev
);
298 void unregister_blkdev(unsigned int major
, const char *name
)
300 struct blk_major_name
**n
;
301 struct blk_major_name
*p
= NULL
;
302 int index
= major_to_index(major
);
304 mutex_lock(&major_names_lock
);
305 spin_lock(&major_names_spinlock
);
306 for (n
= &major_names
[index
]; *n
; n
= &(*n
)->next
)
307 if ((*n
)->major
== major
)
309 if (!*n
|| strcmp((*n
)->name
, name
)) {
315 spin_unlock(&major_names_spinlock
);
316 mutex_unlock(&major_names_lock
);
320 EXPORT_SYMBOL(unregister_blkdev
);
322 int blk_alloc_ext_minor(void)
326 idx
= ida_alloc_range(&ext_devt_ida
, 0, NR_EXT_DEVT
, GFP_KERNEL
);
332 void blk_free_ext_minor(unsigned int minor
)
334 ida_free(&ext_devt_ida
, minor
);
337 static char *bdevt_str(dev_t devt
, char *buf
)
339 if (MAJOR(devt
) <= 0xff && MINOR(devt
) <= 0xff) {
340 char tbuf
[BDEVT_SIZE
];
341 snprintf(tbuf
, BDEVT_SIZE
, "%02x%02x", MAJOR(devt
), MINOR(devt
));
342 snprintf(buf
, BDEVT_SIZE
, "%-9s", tbuf
);
344 snprintf(buf
, BDEVT_SIZE
, "%03x:%05x", MAJOR(devt
), MINOR(devt
));
349 void disk_uevent(struct gendisk
*disk
, enum kobject_action action
)
351 struct block_device
*part
;
355 xa_for_each(&disk
->part_tbl
, idx
, part
) {
356 if (bdev_is_partition(part
) && !bdev_nr_sectors(part
))
358 if (!kobject_get_unless_zero(&part
->bd_device
.kobj
))
362 kobject_uevent(bdev_kobj(part
), action
);
363 put_device(&part
->bd_device
);
368 EXPORT_SYMBOL_GPL(disk_uevent
);
370 static void disk_scan_partitions(struct gendisk
*disk
)
372 struct block_device
*bdev
;
374 if (!get_capacity(disk
) || !disk_part_scan_enabled(disk
))
377 set_bit(GD_NEED_PART_SCAN
, &disk
->state
);
378 bdev
= blkdev_get_by_dev(disk_devt(disk
), FMODE_READ
, NULL
);
380 blkdev_put(bdev
, FMODE_READ
);
384 * device_add_disk - add disk information to kernel list
385 * @parent: parent device for the disk
386 * @disk: per-device partitioning information
387 * @groups: Additional per-device sysfs groups
389 * This function registers the partitioning information in @disk
392 int device_add_disk(struct device
*parent
, struct gendisk
*disk
,
393 const struct attribute_group
**groups
)
396 struct device
*ddev
= disk_to_dev(disk
);
400 * The disk queue should now be all set with enough information about
401 * the device for the elevator code to pick an adequate default
402 * elevator if one is needed, that is, for devices requesting queue
405 elevator_init_mq(disk
->queue
);
408 * If the driver provides an explicit major number it also must provide
409 * the number of minors numbers supported, and those will be used to
411 * Otherwise just allocate the device numbers for both the whole device
412 * and all partitions from the extended dev_t space.
415 if (WARN_ON(!disk
->minors
))
418 if (disk
->minors
> DISK_MAX_PARTS
) {
419 pr_err("block: can't allocate more than %d partitions\n",
421 disk
->minors
= DISK_MAX_PARTS
;
424 if (WARN_ON(disk
->minors
))
427 ret
= blk_alloc_ext_minor();
430 disk
->major
= BLOCK_EXT_MAJOR
;
431 disk
->first_minor
= ret
;
432 disk
->flags
|= GENHD_FL_EXT_DEVT
;
435 ret
= disk_alloc_events(disk
);
437 goto out_free_ext_minor
;
439 /* delay uevents, until we scanned partition table */
440 dev_set_uevent_suppress(ddev
, 1);
442 ddev
->parent
= parent
;
443 ddev
->groups
= groups
;
444 dev_set_name(ddev
, "%s", disk
->disk_name
);
445 if (!(disk
->flags
& GENHD_FL_HIDDEN
))
446 ddev
->devt
= MKDEV(disk
->major
, disk
->first_minor
);
447 ret
= device_add(ddev
);
449 goto out_disk_release_events
;
450 if (!sysfs_deprecated
) {
451 ret
= sysfs_create_link(block_depr
, &ddev
->kobj
,
452 kobject_name(&ddev
->kobj
));
458 * avoid probable deadlock caused by allocating memory with
459 * GFP_KERNEL in runtime_resume callback of its all ancestor
462 pm_runtime_set_memalloc_noio(ddev
, true);
464 ret
= blk_integrity_add(disk
);
466 goto out_del_block_link
;
468 disk
->part0
->bd_holder_dir
=
469 kobject_create_and_add("holders", &ddev
->kobj
);
470 if (!disk
->part0
->bd_holder_dir
)
471 goto out_del_integrity
;
472 disk
->slave_dir
= kobject_create_and_add("slaves", &ddev
->kobj
);
473 if (!disk
->slave_dir
)
474 goto out_put_holder_dir
;
476 ret
= bd_register_pending_holders(disk
);
478 goto out_put_slave_dir
;
480 ret
= blk_register_queue(disk
);
482 goto out_put_slave_dir
;
484 if (disk
->flags
& GENHD_FL_HIDDEN
) {
486 * Don't let hidden disks show up in /proc/partitions,
487 * and don't bother scanning for partitions either.
489 disk
->flags
|= GENHD_FL_SUPPRESS_PARTITION_INFO
;
490 disk
->flags
|= GENHD_FL_NO_PART_SCAN
;
492 ret
= bdi_register(disk
->bdi
, "%u:%u",
493 disk
->major
, disk
->first_minor
);
495 goto out_unregister_queue
;
496 bdi_set_owner(disk
->bdi
, ddev
);
497 ret
= sysfs_create_link(&ddev
->kobj
,
498 &disk
->bdi
->dev
->kobj
, "bdi");
500 goto out_unregister_bdi
;
502 bdev_add(disk
->part0
, ddev
->devt
);
503 disk_scan_partitions(disk
);
506 * Announce the disk and partitions after all partitions are
507 * created. (for hidden disks uevents remain suppressed forever)
509 dev_set_uevent_suppress(ddev
, 0);
510 disk_uevent(disk
, KOBJ_ADD
);
513 disk_update_readahead(disk
);
514 disk_add_events(disk
);
518 if (!(disk
->flags
& GENHD_FL_HIDDEN
))
519 bdi_unregister(disk
->bdi
);
520 out_unregister_queue
:
521 blk_unregister_queue(disk
);
523 kobject_put(disk
->slave_dir
);
525 kobject_put(disk
->part0
->bd_holder_dir
);
527 blk_integrity_del(disk
);
529 if (!sysfs_deprecated
)
530 sysfs_remove_link(block_depr
, dev_name(ddev
));
533 out_disk_release_events
:
534 disk_release_events(disk
);
536 if (disk
->major
== BLOCK_EXT_MAJOR
)
537 blk_free_ext_minor(disk
->first_minor
);
538 return WARN_ON_ONCE(ret
); /* keep until all callers handle errors */
540 EXPORT_SYMBOL(device_add_disk
);
543 * del_gendisk - remove the gendisk
544 * @disk: the struct gendisk to remove
546 * Removes the gendisk and all its associated resources. This deletes the
547 * partitions associated with the gendisk, and unregisters the associated
550 * This is the counter to the respective __device_add_disk() call.
552 * The final removal of the struct gendisk happens when its refcount reaches 0
553 * with put_disk(), which should be called after del_gendisk(), if
554 * __device_add_disk() was used.
556 * Drivers exist which depend on the release of the gendisk to be synchronous,
557 * it should not be deferred.
561 void del_gendisk(struct gendisk
*disk
)
563 struct request_queue
*q
= disk
->queue
;
567 if (WARN_ON_ONCE(!disk_live(disk
) && !(disk
->flags
& GENHD_FL_HIDDEN
)))
570 blk_integrity_del(disk
);
571 disk_del_events(disk
);
573 mutex_lock(&disk
->open_mutex
);
574 remove_inode_hash(disk
->part0
->bd_inode
);
575 blk_drop_partitions(disk
);
576 mutex_unlock(&disk
->open_mutex
);
578 fsync_bdev(disk
->part0
);
579 __invalidate_device(disk
->part0
, true);
584 set_bit(GD_DEAD
, &disk
->state
);
585 set_capacity(disk
, 0);
588 * Prevent new I/O from crossing bio_queue_enter().
590 blk_queue_start_drain(q
);
591 blk_mq_freeze_queue_wait(q
);
595 blk_flush_integrity();
597 * Allow using passthrough request again after the queue is torn down.
599 blk_mq_unfreeze_queue(q
);
601 if (!(disk
->flags
& GENHD_FL_HIDDEN
)) {
602 sysfs_remove_link(&disk_to_dev(disk
)->kobj
, "bdi");
605 * Unregister bdi before releasing device numbers (as they can
606 * get reused and we'd get clashes in sysfs).
608 bdi_unregister(disk
->bdi
);
611 blk_unregister_queue(disk
);
613 kobject_put(disk
->part0
->bd_holder_dir
);
614 kobject_put(disk
->slave_dir
);
616 part_stat_set_all(disk
->part0
, 0);
617 disk
->part0
->bd_stamp
= 0;
618 if (!sysfs_deprecated
)
619 sysfs_remove_link(block_depr
, dev_name(disk_to_dev(disk
)));
620 pm_runtime_set_memalloc_noio(disk_to_dev(disk
), false);
621 device_del(disk_to_dev(disk
));
623 EXPORT_SYMBOL(del_gendisk
);
625 /* sysfs access to bad-blocks list. */
626 static ssize_t
disk_badblocks_show(struct device
*dev
,
627 struct device_attribute
*attr
,
630 struct gendisk
*disk
= dev_to_disk(dev
);
633 return sprintf(page
, "\n");
635 return badblocks_show(disk
->bb
, page
, 0);
638 static ssize_t
disk_badblocks_store(struct device
*dev
,
639 struct device_attribute
*attr
,
640 const char *page
, size_t len
)
642 struct gendisk
*disk
= dev_to_disk(dev
);
647 return badblocks_store(disk
->bb
, page
, len
, 0);
650 void blk_request_module(dev_t devt
)
652 unsigned int major
= MAJOR(devt
);
653 struct blk_major_name
**n
;
655 mutex_lock(&major_names_lock
);
656 for (n
= &major_names
[major_to_index(major
)]; *n
; n
= &(*n
)->next
) {
657 if ((*n
)->major
== major
&& (*n
)->probe
) {
659 mutex_unlock(&major_names_lock
);
663 mutex_unlock(&major_names_lock
);
665 if (request_module("block-major-%d-%d", MAJOR(devt
), MINOR(devt
)) > 0)
666 /* Make old-style 2.4 aliases work */
667 request_module("block-major-%d", MAJOR(devt
));
671 * print a full list of all partitions - intended for places where the root
672 * filesystem can't be mounted and thus to give the victim some idea of what
675 void __init
printk_all_partitions(void)
677 struct class_dev_iter iter
;
680 class_dev_iter_init(&iter
, &block_class
, NULL
, &disk_type
);
681 while ((dev
= class_dev_iter_next(&iter
))) {
682 struct gendisk
*disk
= dev_to_disk(dev
);
683 struct block_device
*part
;
684 char devt_buf
[BDEVT_SIZE
];
688 * Don't show empty devices or things that have been
691 if (get_capacity(disk
) == 0 ||
692 (disk
->flags
& GENHD_FL_SUPPRESS_PARTITION_INFO
))
696 * Note, unlike /proc/partitions, I am showing the numbers in
697 * hex - the same format as the root= option takes.
700 xa_for_each(&disk
->part_tbl
, idx
, part
) {
701 if (!bdev_nr_sectors(part
))
703 printk("%s%s %10llu %pg %s",
704 bdev_is_partition(part
) ? " " : "",
705 bdevt_str(part
->bd_dev
, devt_buf
),
706 bdev_nr_sectors(part
) >> 1, part
,
708 part
->bd_meta_info
->uuid
: "");
709 if (bdev_is_partition(part
))
711 else if (dev
->parent
&& dev
->parent
->driver
)
712 printk(" driver: %s\n",
713 dev
->parent
->driver
->name
);
715 printk(" (driver?)\n");
719 class_dev_iter_exit(&iter
);
722 #ifdef CONFIG_PROC_FS
724 static void *disk_seqf_start(struct seq_file
*seqf
, loff_t
*pos
)
727 struct class_dev_iter
*iter
;
730 iter
= kmalloc(sizeof(*iter
), GFP_KERNEL
);
732 return ERR_PTR(-ENOMEM
);
734 seqf
->private = iter
;
735 class_dev_iter_init(iter
, &block_class
, NULL
, &disk_type
);
737 dev
= class_dev_iter_next(iter
);
742 return dev_to_disk(dev
);
745 static void *disk_seqf_next(struct seq_file
*seqf
, void *v
, loff_t
*pos
)
750 dev
= class_dev_iter_next(seqf
->private);
752 return dev_to_disk(dev
);
757 static void disk_seqf_stop(struct seq_file
*seqf
, void *v
)
759 struct class_dev_iter
*iter
= seqf
->private;
761 /* stop is called even after start failed :-( */
763 class_dev_iter_exit(iter
);
765 seqf
->private = NULL
;
769 static void *show_partition_start(struct seq_file
*seqf
, loff_t
*pos
)
773 p
= disk_seqf_start(seqf
, pos
);
774 if (!IS_ERR_OR_NULL(p
) && !*pos
)
775 seq_puts(seqf
, "major minor #blocks name\n\n");
779 static int show_partition(struct seq_file
*seqf
, void *v
)
781 struct gendisk
*sgp
= v
;
782 struct block_device
*part
;
785 /* Don't show non-partitionable removeable devices or empty devices */
786 if (!get_capacity(sgp
) || (!disk_max_parts(sgp
) &&
787 (sgp
->flags
& GENHD_FL_REMOVABLE
)))
789 if (sgp
->flags
& GENHD_FL_SUPPRESS_PARTITION_INFO
)
793 xa_for_each(&sgp
->part_tbl
, idx
, part
) {
794 if (!bdev_nr_sectors(part
))
796 seq_printf(seqf
, "%4d %7d %10llu %pg\n",
797 MAJOR(part
->bd_dev
), MINOR(part
->bd_dev
),
798 bdev_nr_sectors(part
) >> 1, part
);
804 static const struct seq_operations partitions_op
= {
805 .start
= show_partition_start
,
806 .next
= disk_seqf_next
,
807 .stop
= disk_seqf_stop
,
808 .show
= show_partition
812 static int __init
genhd_device_init(void)
816 block_class
.dev_kobj
= sysfs_dev_block_kobj
;
817 error
= class_register(&block_class
);
822 register_blkdev(BLOCK_EXT_MAJOR
, "blkext");
824 /* create top-level block dir */
825 if (!sysfs_deprecated
)
826 block_depr
= kobject_create_and_add("block", NULL
);
830 subsys_initcall(genhd_device_init
);
832 static ssize_t
disk_range_show(struct device
*dev
,
833 struct device_attribute
*attr
, char *buf
)
835 struct gendisk
*disk
= dev_to_disk(dev
);
837 return sprintf(buf
, "%d\n", disk
->minors
);
840 static ssize_t
disk_ext_range_show(struct device
*dev
,
841 struct device_attribute
*attr
, char *buf
)
843 struct gendisk
*disk
= dev_to_disk(dev
);
845 return sprintf(buf
, "%d\n", disk_max_parts(disk
));
848 static ssize_t
disk_removable_show(struct device
*dev
,
849 struct device_attribute
*attr
, char *buf
)
851 struct gendisk
*disk
= dev_to_disk(dev
);
853 return sprintf(buf
, "%d\n",
854 (disk
->flags
& GENHD_FL_REMOVABLE
? 1 : 0));
857 static ssize_t
disk_hidden_show(struct device
*dev
,
858 struct device_attribute
*attr
, char *buf
)
860 struct gendisk
*disk
= dev_to_disk(dev
);
862 return sprintf(buf
, "%d\n",
863 (disk
->flags
& GENHD_FL_HIDDEN
? 1 : 0));
866 static ssize_t
disk_ro_show(struct device
*dev
,
867 struct device_attribute
*attr
, char *buf
)
869 struct gendisk
*disk
= dev_to_disk(dev
);
871 return sprintf(buf
, "%d\n", get_disk_ro(disk
) ? 1 : 0);
874 ssize_t
part_size_show(struct device
*dev
,
875 struct device_attribute
*attr
, char *buf
)
877 return sprintf(buf
, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev
)));
880 ssize_t
part_stat_show(struct device
*dev
,
881 struct device_attribute
*attr
, char *buf
)
883 struct block_device
*bdev
= dev_to_bdev(dev
);
884 struct request_queue
*q
= bdev
->bd_disk
->queue
;
885 struct disk_stats stat
;
886 unsigned int inflight
;
888 part_stat_read_all(bdev
, &stat
);
890 inflight
= blk_mq_in_flight(q
, bdev
);
892 inflight
= part_in_flight(bdev
);
895 "%8lu %8lu %8llu %8u "
896 "%8lu %8lu %8llu %8u "
898 "%8lu %8lu %8llu %8u "
902 stat
.merges
[STAT_READ
],
903 (unsigned long long)stat
.sectors
[STAT_READ
],
904 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
], NSEC_PER_MSEC
),
905 stat
.ios
[STAT_WRITE
],
906 stat
.merges
[STAT_WRITE
],
907 (unsigned long long)stat
.sectors
[STAT_WRITE
],
908 (unsigned int)div_u64(stat
.nsecs
[STAT_WRITE
], NSEC_PER_MSEC
),
910 jiffies_to_msecs(stat
.io_ticks
),
911 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
] +
912 stat
.nsecs
[STAT_WRITE
] +
913 stat
.nsecs
[STAT_DISCARD
] +
914 stat
.nsecs
[STAT_FLUSH
],
916 stat
.ios
[STAT_DISCARD
],
917 stat
.merges
[STAT_DISCARD
],
918 (unsigned long long)stat
.sectors
[STAT_DISCARD
],
919 (unsigned int)div_u64(stat
.nsecs
[STAT_DISCARD
], NSEC_PER_MSEC
),
920 stat
.ios
[STAT_FLUSH
],
921 (unsigned int)div_u64(stat
.nsecs
[STAT_FLUSH
], NSEC_PER_MSEC
));
924 ssize_t
part_inflight_show(struct device
*dev
, struct device_attribute
*attr
,
927 struct block_device
*bdev
= dev_to_bdev(dev
);
928 struct request_queue
*q
= bdev
->bd_disk
->queue
;
929 unsigned int inflight
[2];
932 blk_mq_in_flight_rw(q
, bdev
, inflight
);
934 part_in_flight_rw(bdev
, inflight
);
936 return sprintf(buf
, "%8u %8u\n", inflight
[0], inflight
[1]);
939 static ssize_t
disk_capability_show(struct device
*dev
,
940 struct device_attribute
*attr
, char *buf
)
942 struct gendisk
*disk
= dev_to_disk(dev
);
944 return sprintf(buf
, "%x\n", disk
->flags
);
947 static ssize_t
disk_alignment_offset_show(struct device
*dev
,
948 struct device_attribute
*attr
,
951 struct gendisk
*disk
= dev_to_disk(dev
);
953 return sprintf(buf
, "%d\n", queue_alignment_offset(disk
->queue
));
956 static ssize_t
disk_discard_alignment_show(struct device
*dev
,
957 struct device_attribute
*attr
,
960 struct gendisk
*disk
= dev_to_disk(dev
);
962 return sprintf(buf
, "%d\n", queue_discard_alignment(disk
->queue
));
965 static ssize_t
diskseq_show(struct device
*dev
,
966 struct device_attribute
*attr
, char *buf
)
968 struct gendisk
*disk
= dev_to_disk(dev
);
970 return sprintf(buf
, "%llu\n", disk
->diskseq
);
973 static DEVICE_ATTR(range
, 0444, disk_range_show
, NULL
);
974 static DEVICE_ATTR(ext_range
, 0444, disk_ext_range_show
, NULL
);
975 static DEVICE_ATTR(removable
, 0444, disk_removable_show
, NULL
);
976 static DEVICE_ATTR(hidden
, 0444, disk_hidden_show
, NULL
);
977 static DEVICE_ATTR(ro
, 0444, disk_ro_show
, NULL
);
978 static DEVICE_ATTR(size
, 0444, part_size_show
, NULL
);
979 static DEVICE_ATTR(alignment_offset
, 0444, disk_alignment_offset_show
, NULL
);
980 static DEVICE_ATTR(discard_alignment
, 0444, disk_discard_alignment_show
, NULL
);
981 static DEVICE_ATTR(capability
, 0444, disk_capability_show
, NULL
);
982 static DEVICE_ATTR(stat
, 0444, part_stat_show
, NULL
);
983 static DEVICE_ATTR(inflight
, 0444, part_inflight_show
, NULL
);
984 static DEVICE_ATTR(badblocks
, 0644, disk_badblocks_show
, disk_badblocks_store
);
985 static DEVICE_ATTR(diskseq
, 0444, diskseq_show
, NULL
);
987 #ifdef CONFIG_FAIL_MAKE_REQUEST
988 ssize_t
part_fail_show(struct device
*dev
,
989 struct device_attribute
*attr
, char *buf
)
991 return sprintf(buf
, "%d\n", dev_to_bdev(dev
)->bd_make_it_fail
);
994 ssize_t
part_fail_store(struct device
*dev
,
995 struct device_attribute
*attr
,
996 const char *buf
, size_t count
)
1000 if (count
> 0 && sscanf(buf
, "%d", &i
) > 0)
1001 dev_to_bdev(dev
)->bd_make_it_fail
= i
;
1006 static struct device_attribute dev_attr_fail
=
1007 __ATTR(make
-it
-fail
, 0644, part_fail_show
, part_fail_store
);
1008 #endif /* CONFIG_FAIL_MAKE_REQUEST */
1010 #ifdef CONFIG_FAIL_IO_TIMEOUT
1011 static struct device_attribute dev_attr_fail_timeout
=
1012 __ATTR(io
-timeout
-fail
, 0644, part_timeout_show
, part_timeout_store
);
1015 static struct attribute
*disk_attrs
[] = {
1016 &dev_attr_range
.attr
,
1017 &dev_attr_ext_range
.attr
,
1018 &dev_attr_removable
.attr
,
1019 &dev_attr_hidden
.attr
,
1021 &dev_attr_size
.attr
,
1022 &dev_attr_alignment_offset
.attr
,
1023 &dev_attr_discard_alignment
.attr
,
1024 &dev_attr_capability
.attr
,
1025 &dev_attr_stat
.attr
,
1026 &dev_attr_inflight
.attr
,
1027 &dev_attr_badblocks
.attr
,
1028 &dev_attr_events
.attr
,
1029 &dev_attr_events_async
.attr
,
1030 &dev_attr_events_poll_msecs
.attr
,
1031 &dev_attr_diskseq
.attr
,
1032 #ifdef CONFIG_FAIL_MAKE_REQUEST
1033 &dev_attr_fail
.attr
,
1035 #ifdef CONFIG_FAIL_IO_TIMEOUT
1036 &dev_attr_fail_timeout
.attr
,
1041 static umode_t
disk_visible(struct kobject
*kobj
, struct attribute
*a
, int n
)
1043 struct device
*dev
= container_of(kobj
, typeof(*dev
), kobj
);
1044 struct gendisk
*disk
= dev_to_disk(dev
);
1046 if (a
== &dev_attr_badblocks
.attr
&& !disk
->bb
)
1051 static struct attribute_group disk_attr_group
= {
1052 .attrs
= disk_attrs
,
1053 .is_visible
= disk_visible
,
1056 static const struct attribute_group
*disk_attr_groups
[] = {
1062 * disk_release - releases all allocated resources of the gendisk
1063 * @dev: the device representing this disk
1065 * This function releases all allocated resources of the gendisk.
1067 * Drivers which used __device_add_disk() have a gendisk with a request_queue
1068 * assigned. Since the request_queue sits on top of the gendisk for these
1069 * drivers we also call blk_put_queue() for them, and we expect the
1070 * request_queue refcount to reach 0 at this point, and so the request_queue
1071 * will also be freed prior to the disk.
1073 * Context: can sleep
1075 static void disk_release(struct device
*dev
)
1077 struct gendisk
*disk
= dev_to_disk(dev
);
1081 disk_release_events(disk
);
1082 kfree(disk
->random
);
1083 xa_destroy(&disk
->part_tbl
);
1084 disk
->queue
->disk
= NULL
;
1085 blk_put_queue(disk
->queue
);
1086 iput(disk
->part0
->bd_inode
); /* frees the disk */
1089 static int block_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
1091 struct gendisk
*disk
= dev_to_disk(dev
);
1093 return add_uevent_var(env
, "DISKSEQ=%llu", disk
->diskseq
);
1096 struct class block_class
= {
1098 .dev_uevent
= block_uevent
,
1101 static char *block_devnode(struct device
*dev
, umode_t
*mode
,
1102 kuid_t
*uid
, kgid_t
*gid
)
1104 struct gendisk
*disk
= dev_to_disk(dev
);
1106 if (disk
->fops
->devnode
)
1107 return disk
->fops
->devnode(disk
, mode
);
1111 const struct device_type disk_type
= {
1113 .groups
= disk_attr_groups
,
1114 .release
= disk_release
,
1115 .devnode
= block_devnode
,
1118 #ifdef CONFIG_PROC_FS
1120 * aggregate disk stat collector. Uses the same stats that the sysfs
1121 * entries do, above, but makes them available through one seq_file.
1123 * The output looks suspiciously like /proc/partitions with a bunch of
1126 static int diskstats_show(struct seq_file
*seqf
, void *v
)
1128 struct gendisk
*gp
= v
;
1129 struct block_device
*hd
;
1130 unsigned int inflight
;
1131 struct disk_stats stat
;
1135 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1136 seq_puts(seqf, "major minor name"
1137 " rio rmerge rsect ruse wio wmerge "
1138 "wsect wuse running use aveq"
1143 xa_for_each(&gp
->part_tbl
, idx
, hd
) {
1144 if (bdev_is_partition(hd
) && !bdev_nr_sectors(hd
))
1146 part_stat_read_all(hd
, &stat
);
1147 if (queue_is_mq(gp
->queue
))
1148 inflight
= blk_mq_in_flight(gp
->queue
, hd
);
1150 inflight
= part_in_flight(hd
);
1152 seq_printf(seqf
, "%4d %7d %pg "
1159 MAJOR(hd
->bd_dev
), MINOR(hd
->bd_dev
), hd
,
1160 stat
.ios
[STAT_READ
],
1161 stat
.merges
[STAT_READ
],
1162 stat
.sectors
[STAT_READ
],
1163 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
],
1165 stat
.ios
[STAT_WRITE
],
1166 stat
.merges
[STAT_WRITE
],
1167 stat
.sectors
[STAT_WRITE
],
1168 (unsigned int)div_u64(stat
.nsecs
[STAT_WRITE
],
1171 jiffies_to_msecs(stat
.io_ticks
),
1172 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
] +
1173 stat
.nsecs
[STAT_WRITE
] +
1174 stat
.nsecs
[STAT_DISCARD
] +
1175 stat
.nsecs
[STAT_FLUSH
],
1177 stat
.ios
[STAT_DISCARD
],
1178 stat
.merges
[STAT_DISCARD
],
1179 stat
.sectors
[STAT_DISCARD
],
1180 (unsigned int)div_u64(stat
.nsecs
[STAT_DISCARD
],
1182 stat
.ios
[STAT_FLUSH
],
1183 (unsigned int)div_u64(stat
.nsecs
[STAT_FLUSH
],
1192 static const struct seq_operations diskstats_op
= {
1193 .start
= disk_seqf_start
,
1194 .next
= disk_seqf_next
,
1195 .stop
= disk_seqf_stop
,
1196 .show
= diskstats_show
1199 static int __init
proc_genhd_init(void)
1201 proc_create_seq("diskstats", 0, NULL
, &diskstats_op
);
1202 proc_create_seq("partitions", 0, NULL
, &partitions_op
);
1205 module_init(proc_genhd_init
);
1206 #endif /* CONFIG_PROC_FS */
1208 dev_t
part_devt(struct gendisk
*disk
, u8 partno
)
1210 struct block_device
*part
;
1214 part
= xa_load(&disk
->part_tbl
, partno
);
1216 devt
= part
->bd_dev
;
1222 dev_t
blk_lookup_devt(const char *name
, int partno
)
1224 dev_t devt
= MKDEV(0, 0);
1225 struct class_dev_iter iter
;
1228 class_dev_iter_init(&iter
, &block_class
, NULL
, &disk_type
);
1229 while ((dev
= class_dev_iter_next(&iter
))) {
1230 struct gendisk
*disk
= dev_to_disk(dev
);
1232 if (strcmp(dev_name(dev
), name
))
1235 if (partno
< disk
->minors
) {
1236 /* We need to return the right devno, even
1237 * if the partition doesn't exist yet.
1239 devt
= MKDEV(MAJOR(dev
->devt
),
1240 MINOR(dev
->devt
) + partno
);
1242 devt
= part_devt(disk
, partno
);
1247 class_dev_iter_exit(&iter
);
1251 struct gendisk
*__alloc_disk_node(struct request_queue
*q
, int node_id
,
1252 struct lock_class_key
*lkclass
)
1254 struct gendisk
*disk
;
1256 if (!blk_get_queue(q
))
1259 disk
= kzalloc_node(sizeof(struct gendisk
), GFP_KERNEL
, node_id
);
1263 disk
->bdi
= bdi_alloc(node_id
);
1267 disk
->part0
= bdev_alloc(disk
, 0);
1271 disk
->node_id
= node_id
;
1272 mutex_init(&disk
->open_mutex
);
1273 xa_init(&disk
->part_tbl
);
1274 if (xa_insert(&disk
->part_tbl
, 0, disk
->part0
, GFP_KERNEL
))
1275 goto out_destroy_part_tbl
;
1277 rand_initialize_disk(disk
);
1278 disk_to_dev(disk
)->class = &block_class
;
1279 disk_to_dev(disk
)->type
= &disk_type
;
1280 device_initialize(disk_to_dev(disk
));
1284 lockdep_init_map(&disk
->lockdep_map
, "(bio completion)", lkclass
, 0);
1285 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
1286 INIT_LIST_HEAD(&disk
->slave_bdevs
);
1290 out_destroy_part_tbl
:
1291 xa_destroy(&disk
->part_tbl
);
1292 disk
->part0
->bd_disk
= NULL
;
1293 iput(disk
->part0
->bd_inode
);
1302 EXPORT_SYMBOL(__alloc_disk_node
);
1304 struct gendisk
*__blk_alloc_disk(int node
, struct lock_class_key
*lkclass
)
1306 struct request_queue
*q
;
1307 struct gendisk
*disk
;
1309 q
= blk_alloc_queue(node
);
1313 disk
= __alloc_disk_node(q
, node
, lkclass
);
1315 blk_cleanup_queue(q
);
1320 EXPORT_SYMBOL(__blk_alloc_disk
);
1323 * put_disk - decrements the gendisk refcount
1324 * @disk: the struct gendisk to decrement the refcount for
1326 * This decrements the refcount for the struct gendisk. When this reaches 0
1327 * we'll have disk_release() called.
1329 * Context: Any context, but the last reference must not be dropped from
1332 void put_disk(struct gendisk
*disk
)
1335 put_device(disk_to_dev(disk
));
1337 EXPORT_SYMBOL(put_disk
);
1340 * blk_cleanup_disk - shutdown a gendisk allocated by blk_alloc_disk
1341 * @disk: gendisk to shutdown
1343 * Mark the queue hanging off @disk DYING, drain all pending requests, then mark
1344 * the queue DEAD, destroy and put it and the gendisk structure.
1346 * Context: can sleep
1348 void blk_cleanup_disk(struct gendisk
*disk
)
1350 blk_cleanup_queue(disk
->queue
);
1353 EXPORT_SYMBOL(blk_cleanup_disk
);
1355 static void set_disk_ro_uevent(struct gendisk
*gd
, int ro
)
1357 char event
[] = "DISK_RO=1";
1358 char *envp
[] = { event
, NULL
};
1362 kobject_uevent_env(&disk_to_dev(gd
)->kobj
, KOBJ_CHANGE
, envp
);
1366 * set_disk_ro - set a gendisk read-only
1367 * @disk: gendisk to operate on
1368 * @read_only: %true to set the disk read-only, %false set the disk read/write
1370 * This function is used to indicate whether a given disk device should have its
1371 * read-only flag set. set_disk_ro() is typically used by device drivers to
1372 * indicate whether the underlying physical device is write-protected.
1374 void set_disk_ro(struct gendisk
*disk
, bool read_only
)
1377 if (test_and_set_bit(GD_READ_ONLY
, &disk
->state
))
1380 if (!test_and_clear_bit(GD_READ_ONLY
, &disk
->state
))
1383 set_disk_ro_uevent(disk
, read_only
);
1385 EXPORT_SYMBOL(set_disk_ro
);
1387 int bdev_read_only(struct block_device
*bdev
)
1389 return bdev
->bd_read_only
|| get_disk_ro(bdev
->bd_disk
);
1391 EXPORT_SYMBOL(bdev_read_only
);
1393 void inc_diskseq(struct gendisk
*disk
)
1395 disk
->diskseq
= atomic64_inc_return(&diskseq
);