1 // SPDX-License-Identifier: GPL-2.0
6 #include <linux/module.h>
7 #include <linux/ctype.h>
9 #include <linux/genhd.h>
10 #include <linux/kdev_t.h>
11 #include <linux/kernel.h>
12 #include <linux/blkdev.h>
13 #include <linux/backing-dev.h>
14 #include <linux/init.h>
15 #include <linux/spinlock.h>
16 #include <linux/proc_fs.h>
17 #include <linux/seq_file.h>
18 #include <linux/slab.h>
19 #include <linux/kmod.h>
20 #include <linux/kobj_map.h>
21 #include <linux/mutex.h>
22 #include <linux/idr.h>
23 #include <linux/log2.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/badblocks.h>
29 static DEFINE_MUTEX(block_class_lock
);
30 static struct kobject
*block_depr
;
32 /* for extended dynamic devt allocation, currently only one major is used */
33 #define NR_EXT_DEVT (1 << MINORBITS)
35 /* For extended devt allocation. ext_devt_lock prevents look up
36 * results from going away underneath its user.
38 static DEFINE_SPINLOCK(ext_devt_lock
);
39 static DEFINE_IDR(ext_devt_idr
);
41 static void disk_check_events(struct disk_events
*ev
,
42 unsigned int *clearing_ptr
);
43 static void disk_alloc_events(struct gendisk
*disk
);
44 static void disk_add_events(struct gendisk
*disk
);
45 static void disk_del_events(struct gendisk
*disk
);
46 static void disk_release_events(struct gendisk
*disk
);
49 * Set disk capacity and notify if the size is not currently
50 * zero and will not be set to zero
52 void set_capacity_revalidate_and_notify(struct gendisk
*disk
, sector_t size
,
55 sector_t capacity
= get_capacity(disk
);
57 set_capacity(disk
, size
);
59 revalidate_disk_size(disk
, true);
61 if (capacity
!= size
&& capacity
!= 0 && size
!= 0) {
62 char *envp
[] = { "RESIZE=1", NULL
};
64 kobject_uevent_env(&disk_to_dev(disk
)->kobj
, KOBJ_CHANGE
, envp
);
68 EXPORT_SYMBOL_GPL(set_capacity_revalidate_and_notify
);
71 * Format the device name of the indicated disk into the supplied buffer and
72 * return a pointer to that same buffer for convenience.
74 char *disk_name(struct gendisk
*hd
, int partno
, char *buf
)
77 snprintf(buf
, BDEVNAME_SIZE
, "%s", hd
->disk_name
);
78 else if (isdigit(hd
->disk_name
[strlen(hd
->disk_name
)-1]))
79 snprintf(buf
, BDEVNAME_SIZE
, "%sp%d", hd
->disk_name
, partno
);
81 snprintf(buf
, BDEVNAME_SIZE
, "%s%d", hd
->disk_name
, partno
);
86 const char *bdevname(struct block_device
*bdev
, char *buf
)
88 return disk_name(bdev
->bd_disk
, bdev
->bd_partno
, buf
);
90 EXPORT_SYMBOL(bdevname
);
92 static void part_stat_read_all(struct hd_struct
*part
, struct disk_stats
*stat
)
96 memset(stat
, 0, sizeof(struct disk_stats
));
97 for_each_possible_cpu(cpu
) {
98 struct disk_stats
*ptr
= per_cpu_ptr(part
->dkstats
, cpu
);
101 for (group
= 0; group
< NR_STAT_GROUPS
; group
++) {
102 stat
->nsecs
[group
] += ptr
->nsecs
[group
];
103 stat
->sectors
[group
] += ptr
->sectors
[group
];
104 stat
->ios
[group
] += ptr
->ios
[group
];
105 stat
->merges
[group
] += ptr
->merges
[group
];
108 stat
->io_ticks
+= ptr
->io_ticks
;
112 static unsigned int part_in_flight(struct hd_struct
*part
)
114 unsigned int inflight
= 0;
117 for_each_possible_cpu(cpu
) {
118 inflight
+= part_stat_local_read_cpu(part
, in_flight
[0], cpu
) +
119 part_stat_local_read_cpu(part
, in_flight
[1], cpu
);
121 if ((int)inflight
< 0)
127 static void part_in_flight_rw(struct hd_struct
*part
, unsigned int inflight
[2])
133 for_each_possible_cpu(cpu
) {
134 inflight
[0] += part_stat_local_read_cpu(part
, in_flight
[0], cpu
);
135 inflight
[1] += part_stat_local_read_cpu(part
, in_flight
[1], cpu
);
137 if ((int)inflight
[0] < 0)
139 if ((int)inflight
[1] < 0)
143 struct hd_struct
*__disk_get_part(struct gendisk
*disk
, int partno
)
145 struct disk_part_tbl
*ptbl
= rcu_dereference(disk
->part_tbl
);
147 if (unlikely(partno
< 0 || partno
>= ptbl
->len
))
149 return rcu_dereference(ptbl
->part
[partno
]);
153 * disk_get_part - get partition
154 * @disk: disk to look partition from
155 * @partno: partition number
157 * Look for partition @partno from @disk. If found, increment
158 * reference count and return it.
164 * Pointer to the found partition on success, NULL if not found.
166 struct hd_struct
*disk_get_part(struct gendisk
*disk
, int partno
)
168 struct hd_struct
*part
;
171 part
= __disk_get_part(disk
, partno
);
173 get_device(part_to_dev(part
));
180 * disk_part_iter_init - initialize partition iterator
181 * @piter: iterator to initialize
182 * @disk: disk to iterate over
183 * @flags: DISK_PITER_* flags
185 * Initialize @piter so that it iterates over partitions of @disk.
190 void disk_part_iter_init(struct disk_part_iter
*piter
, struct gendisk
*disk
,
193 struct disk_part_tbl
*ptbl
;
196 ptbl
= rcu_dereference(disk
->part_tbl
);
201 if (flags
& DISK_PITER_REVERSE
)
202 piter
->idx
= ptbl
->len
- 1;
203 else if (flags
& (DISK_PITER_INCL_PART0
| DISK_PITER_INCL_EMPTY_PART0
))
208 piter
->flags
= flags
;
212 EXPORT_SYMBOL_GPL(disk_part_iter_init
);
215 * disk_part_iter_next - proceed iterator to the next partition and return it
216 * @piter: iterator of interest
218 * Proceed @piter to the next partition and return it.
223 struct hd_struct
*disk_part_iter_next(struct disk_part_iter
*piter
)
225 struct disk_part_tbl
*ptbl
;
228 /* put the last partition */
229 disk_put_part(piter
->part
);
234 ptbl
= rcu_dereference(piter
->disk
->part_tbl
);
236 /* determine iteration parameters */
237 if (piter
->flags
& DISK_PITER_REVERSE
) {
239 if (piter
->flags
& (DISK_PITER_INCL_PART0
|
240 DISK_PITER_INCL_EMPTY_PART0
))
249 /* iterate to the next partition */
250 for (; piter
->idx
!= end
; piter
->idx
+= inc
) {
251 struct hd_struct
*part
;
253 part
= rcu_dereference(ptbl
->part
[piter
->idx
]);
256 if (!part_nr_sects_read(part
) &&
257 !(piter
->flags
& DISK_PITER_INCL_EMPTY
) &&
258 !(piter
->flags
& DISK_PITER_INCL_EMPTY_PART0
&&
262 get_device(part_to_dev(part
));
272 EXPORT_SYMBOL_GPL(disk_part_iter_next
);
275 * disk_part_iter_exit - finish up partition iteration
276 * @piter: iter of interest
278 * Called when iteration is over. Cleans up @piter.
283 void disk_part_iter_exit(struct disk_part_iter
*piter
)
285 disk_put_part(piter
->part
);
288 EXPORT_SYMBOL_GPL(disk_part_iter_exit
);
290 static inline int sector_in_part(struct hd_struct
*part
, sector_t sector
)
292 return part
->start_sect
<= sector
&&
293 sector
< part
->start_sect
+ part_nr_sects_read(part
);
297 * disk_map_sector_rcu - map sector to partition
298 * @disk: gendisk of interest
299 * @sector: sector to map
301 * Find out which partition @sector maps to on @disk. This is
302 * primarily used for stats accounting.
305 * RCU read locked. The returned partition pointer is always valid
306 * because its refcount is grabbed except for part0, which lifetime
307 * is same with the disk.
310 * Found partition on success, part0 is returned if no partition matches
311 * or the matched partition is being deleted.
313 struct hd_struct
*disk_map_sector_rcu(struct gendisk
*disk
, sector_t sector
)
315 struct disk_part_tbl
*ptbl
;
316 struct hd_struct
*part
;
320 ptbl
= rcu_dereference(disk
->part_tbl
);
322 part
= rcu_dereference(ptbl
->last_lookup
);
323 if (part
&& sector_in_part(part
, sector
) && hd_struct_try_get(part
))
326 for (i
= 1; i
< ptbl
->len
; i
++) {
327 part
= rcu_dereference(ptbl
->part
[i
]);
329 if (part
&& sector_in_part(part
, sector
)) {
331 * only live partition can be cached for lookup,
332 * so use-after-free on cached & deleting partition
335 if (!hd_struct_try_get(part
))
337 rcu_assign_pointer(ptbl
->last_lookup
, part
);
349 * disk_has_partitions
350 * @disk: gendisk of interest
352 * Walk through the partition table and check if valid partition exists.
358 * True if the gendisk has at least one valid non-zero size partition.
361 bool disk_has_partitions(struct gendisk
*disk
)
363 struct disk_part_tbl
*ptbl
;
368 ptbl
= rcu_dereference(disk
->part_tbl
);
370 /* Iterate partitions skipping the whole device at index 0 */
371 for (i
= 1; i
< ptbl
->len
; i
++) {
372 if (rcu_dereference(ptbl
->part
[i
])) {
382 EXPORT_SYMBOL_GPL(disk_has_partitions
);
385 * Can be deleted altogether. Later.
388 #define BLKDEV_MAJOR_HASH_SIZE 255
389 static struct blk_major_name
{
390 struct blk_major_name
*next
;
393 } *major_names
[BLKDEV_MAJOR_HASH_SIZE
];
395 /* index in the above - for now: assume no multimajor ranges */
396 static inline int major_to_index(unsigned major
)
398 return major
% BLKDEV_MAJOR_HASH_SIZE
;
401 #ifdef CONFIG_PROC_FS
402 void blkdev_show(struct seq_file
*seqf
, off_t offset
)
404 struct blk_major_name
*dp
;
406 mutex_lock(&block_class_lock
);
407 for (dp
= major_names
[major_to_index(offset
)]; dp
; dp
= dp
->next
)
408 if (dp
->major
== offset
)
409 seq_printf(seqf
, "%3d %s\n", dp
->major
, dp
->name
);
410 mutex_unlock(&block_class_lock
);
412 #endif /* CONFIG_PROC_FS */
415 * register_blkdev - register a new block device
417 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
418 * @major = 0, try to allocate any unused major number.
419 * @name: the name of the new block device as a zero terminated string
421 * The @name must be unique within the system.
423 * The return value depends on the @major input parameter:
425 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
426 * then the function returns zero on success, or a negative error code
427 * - if any unused major number was requested with @major = 0 parameter
428 * then the return value is the allocated major number in range
429 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
431 * See Documentation/admin-guide/devices.txt for the list of allocated
434 int register_blkdev(unsigned int major
, const char *name
)
436 struct blk_major_name
**n
, *p
;
439 mutex_lock(&block_class_lock
);
443 for (index
= ARRAY_SIZE(major_names
)-1; index
> 0; index
--) {
444 if (major_names
[index
] == NULL
)
449 printk("%s: failed to get major for %s\n",
458 if (major
>= BLKDEV_MAJOR_MAX
) {
459 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
460 __func__
, major
, BLKDEV_MAJOR_MAX
-1, name
);
466 p
= kmalloc(sizeof(struct blk_major_name
), GFP_KERNEL
);
473 strlcpy(p
->name
, name
, sizeof(p
->name
));
475 index
= major_to_index(major
);
477 for (n
= &major_names
[index
]; *n
; n
= &(*n
)->next
) {
478 if ((*n
)->major
== major
)
487 printk("register_blkdev: cannot get major %u for %s\n",
492 mutex_unlock(&block_class_lock
);
496 EXPORT_SYMBOL(register_blkdev
);
498 void unregister_blkdev(unsigned int major
, const char *name
)
500 struct blk_major_name
**n
;
501 struct blk_major_name
*p
= NULL
;
502 int index
= major_to_index(major
);
504 mutex_lock(&block_class_lock
);
505 for (n
= &major_names
[index
]; *n
; n
= &(*n
)->next
)
506 if ((*n
)->major
== major
)
508 if (!*n
|| strcmp((*n
)->name
, name
)) {
514 mutex_unlock(&block_class_lock
);
518 EXPORT_SYMBOL(unregister_blkdev
);
520 static struct kobj_map
*bdev_map
;
523 * blk_mangle_minor - scatter minor numbers apart
524 * @minor: minor number to mangle
526 * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
527 * is enabled. Mangling twice gives the original value.
535 static int blk_mangle_minor(int minor
)
537 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
540 for (i
= 0; i
< MINORBITS
/ 2; i
++) {
541 int low
= minor
& (1 << i
);
542 int high
= minor
& (1 << (MINORBITS
- 1 - i
));
543 int distance
= MINORBITS
- 1 - 2 * i
;
545 minor
^= low
| high
; /* clear both bits */
546 low
<<= distance
; /* swap the positions */
548 minor
|= low
| high
; /* and set */
555 * blk_alloc_devt - allocate a dev_t for a partition
556 * @part: partition to allocate dev_t for
557 * @devt: out parameter for resulting dev_t
559 * Allocate a dev_t for block device.
562 * 0 on success, allocated dev_t is returned in *@devt. -errno on
568 int blk_alloc_devt(struct hd_struct
*part
, dev_t
*devt
)
570 struct gendisk
*disk
= part_to_disk(part
);
573 /* in consecutive minor range? */
574 if (part
->partno
< disk
->minors
) {
575 *devt
= MKDEV(disk
->major
, disk
->first_minor
+ part
->partno
);
579 /* allocate ext devt */
580 idr_preload(GFP_KERNEL
);
582 spin_lock_bh(&ext_devt_lock
);
583 idx
= idr_alloc(&ext_devt_idr
, part
, 0, NR_EXT_DEVT
, GFP_NOWAIT
);
584 spin_unlock_bh(&ext_devt_lock
);
588 return idx
== -ENOSPC
? -EBUSY
: idx
;
590 *devt
= MKDEV(BLOCK_EXT_MAJOR
, blk_mangle_minor(idx
));
595 * blk_free_devt - free a dev_t
596 * @devt: dev_t to free
598 * Free @devt which was allocated using blk_alloc_devt().
603 void blk_free_devt(dev_t devt
)
605 if (devt
== MKDEV(0, 0))
608 if (MAJOR(devt
) == BLOCK_EXT_MAJOR
) {
609 spin_lock_bh(&ext_devt_lock
);
610 idr_remove(&ext_devt_idr
, blk_mangle_minor(MINOR(devt
)));
611 spin_unlock_bh(&ext_devt_lock
);
616 * We invalidate devt by assigning NULL pointer for devt in idr.
618 void blk_invalidate_devt(dev_t devt
)
620 if (MAJOR(devt
) == BLOCK_EXT_MAJOR
) {
621 spin_lock_bh(&ext_devt_lock
);
622 idr_replace(&ext_devt_idr
, NULL
, blk_mangle_minor(MINOR(devt
)));
623 spin_unlock_bh(&ext_devt_lock
);
627 static char *bdevt_str(dev_t devt
, char *buf
)
629 if (MAJOR(devt
) <= 0xff && MINOR(devt
) <= 0xff) {
630 char tbuf
[BDEVT_SIZE
];
631 snprintf(tbuf
, BDEVT_SIZE
, "%02x%02x", MAJOR(devt
), MINOR(devt
));
632 snprintf(buf
, BDEVT_SIZE
, "%-9s", tbuf
);
634 snprintf(buf
, BDEVT_SIZE
, "%03x:%05x", MAJOR(devt
), MINOR(devt
));
640 * Register device numbers dev..(dev+range-1)
641 * range must be nonzero
642 * The hash chain is sorted on range, so that subranges can override.
644 void blk_register_region(dev_t devt
, unsigned long range
, struct module
*module
,
645 struct kobject
*(*probe
)(dev_t
, int *, void *),
646 int (*lock
)(dev_t
, void *), void *data
)
648 kobj_map(bdev_map
, devt
, range
, module
, probe
, lock
, data
);
651 EXPORT_SYMBOL(blk_register_region
);
653 void blk_unregister_region(dev_t devt
, unsigned long range
)
655 kobj_unmap(bdev_map
, devt
, range
);
658 EXPORT_SYMBOL(blk_unregister_region
);
660 static struct kobject
*exact_match(dev_t devt
, int *partno
, void *data
)
662 struct gendisk
*p
= data
;
664 return &disk_to_dev(p
)->kobj
;
667 static int exact_lock(dev_t devt
, void *data
)
669 struct gendisk
*p
= data
;
671 if (!get_disk_and_module(p
))
676 static void disk_scan_partitions(struct gendisk
*disk
)
678 struct block_device
*bdev
;
680 if (!get_capacity(disk
) || !disk_part_scan_enabled(disk
))
683 set_bit(GD_NEED_PART_SCAN
, &disk
->state
);
684 bdev
= blkdev_get_by_dev(disk_devt(disk
), FMODE_READ
, NULL
);
686 blkdev_put(bdev
, FMODE_READ
);
689 static void register_disk(struct device
*parent
, struct gendisk
*disk
,
690 const struct attribute_group
**groups
)
692 struct device
*ddev
= disk_to_dev(disk
);
693 struct disk_part_iter piter
;
694 struct hd_struct
*part
;
697 ddev
->parent
= parent
;
699 dev_set_name(ddev
, "%s", disk
->disk_name
);
701 /* delay uevents, until we scanned partition table */
702 dev_set_uevent_suppress(ddev
, 1);
705 WARN_ON(ddev
->groups
);
706 ddev
->groups
= groups
;
708 if (device_add(ddev
))
710 if (!sysfs_deprecated
) {
711 err
= sysfs_create_link(block_depr
, &ddev
->kobj
,
712 kobject_name(&ddev
->kobj
));
720 * avoid probable deadlock caused by allocating memory with
721 * GFP_KERNEL in runtime_resume callback of its all ancestor
724 pm_runtime_set_memalloc_noio(ddev
, true);
726 disk
->part0
.holder_dir
= kobject_create_and_add("holders", &ddev
->kobj
);
727 disk
->slave_dir
= kobject_create_and_add("slaves", &ddev
->kobj
);
729 if (disk
->flags
& GENHD_FL_HIDDEN
) {
730 dev_set_uevent_suppress(ddev
, 0);
734 disk_scan_partitions(disk
);
736 /* announce disk after possible partitions are created */
737 dev_set_uevent_suppress(ddev
, 0);
738 kobject_uevent(&ddev
->kobj
, KOBJ_ADD
);
740 /* announce possible partitions */
741 disk_part_iter_init(&piter
, disk
, 0);
742 while ((part
= disk_part_iter_next(&piter
)))
743 kobject_uevent(&part_to_dev(part
)->kobj
, KOBJ_ADD
);
744 disk_part_iter_exit(&piter
);
746 if (disk
->queue
->backing_dev_info
->dev
) {
747 err
= sysfs_create_link(&ddev
->kobj
,
748 &disk
->queue
->backing_dev_info
->dev
->kobj
,
755 * __device_add_disk - add disk information to kernel list
756 * @parent: parent device for the disk
757 * @disk: per-device partitioning information
758 * @groups: Additional per-device sysfs groups
759 * @register_queue: register the queue if set to true
761 * This function registers the partitioning information in @disk
764 * FIXME: error handling
766 static void __device_add_disk(struct device
*parent
, struct gendisk
*disk
,
767 const struct attribute_group
**groups
,
774 * The disk queue should now be all set with enough information about
775 * the device for the elevator code to pick an adequate default
776 * elevator if one is needed, that is, for devices requesting queue
780 elevator_init_mq(disk
->queue
);
782 /* minors == 0 indicates to use ext devt from part0 and should
783 * be accompanied with EXT_DEVT flag. Make sure all
784 * parameters make sense.
786 WARN_ON(disk
->minors
&& !(disk
->major
|| disk
->first_minor
));
787 WARN_ON(!disk
->minors
&&
788 !(disk
->flags
& (GENHD_FL_EXT_DEVT
| GENHD_FL_HIDDEN
)));
790 disk
->flags
|= GENHD_FL_UP
;
792 retval
= blk_alloc_devt(&disk
->part0
, &devt
);
797 disk
->major
= MAJOR(devt
);
798 disk
->first_minor
= MINOR(devt
);
800 disk_alloc_events(disk
);
802 if (disk
->flags
& GENHD_FL_HIDDEN
) {
804 * Don't let hidden disks show up in /proc/partitions,
805 * and don't bother scanning for partitions either.
807 disk
->flags
|= GENHD_FL_SUPPRESS_PARTITION_INFO
;
808 disk
->flags
|= GENHD_FL_NO_PART_SCAN
;
810 struct backing_dev_info
*bdi
= disk
->queue
->backing_dev_info
;
811 struct device
*dev
= disk_to_dev(disk
);
814 /* Register BDI before referencing it from bdev */
816 ret
= bdi_register(bdi
, "%u:%u", MAJOR(devt
), MINOR(devt
));
818 bdi_set_owner(bdi
, dev
);
819 blk_register_region(disk_devt(disk
), disk
->minors
, NULL
,
820 exact_match
, exact_lock
, disk
);
822 register_disk(parent
, disk
, groups
);
824 blk_register_queue(disk
);
827 * Take an extra ref on queue which will be put on disk_release()
828 * so that it sticks around as long as @disk is there.
830 WARN_ON_ONCE(!blk_get_queue(disk
->queue
));
832 disk_add_events(disk
);
833 blk_integrity_add(disk
);
836 void device_add_disk(struct device
*parent
, struct gendisk
*disk
,
837 const struct attribute_group
**groups
)
840 __device_add_disk(parent
, disk
, groups
, true);
842 EXPORT_SYMBOL(device_add_disk
);
844 void device_add_disk_no_queue_reg(struct device
*parent
, struct gendisk
*disk
)
846 __device_add_disk(parent
, disk
, NULL
, false);
848 EXPORT_SYMBOL(device_add_disk_no_queue_reg
);
850 static void invalidate_partition(struct gendisk
*disk
, int partno
)
852 struct block_device
*bdev
;
854 bdev
= bdget_disk(disk
, partno
);
859 __invalidate_device(bdev
, true);
862 * Unhash the bdev inode for this device so that it gets evicted as soon
863 * as last inode reference is dropped.
865 remove_inode_hash(bdev
->bd_inode
);
870 * del_gendisk - remove the gendisk
871 * @disk: the struct gendisk to remove
873 * Removes the gendisk and all its associated resources. This deletes the
874 * partitions associated with the gendisk, and unregisters the associated
877 * This is the counter to the respective __device_add_disk() call.
879 * The final removal of the struct gendisk happens when its refcount reaches 0
880 * with put_disk(), which should be called after del_gendisk(), if
881 * __device_add_disk() was used.
883 * Drivers exist which depend on the release of the gendisk to be synchronous,
884 * it should not be deferred.
888 void del_gendisk(struct gendisk
*disk
)
890 struct disk_part_iter piter
;
891 struct hd_struct
*part
;
895 blk_integrity_del(disk
);
896 disk_del_events(disk
);
899 * Block lookups of the disk until all bdevs are unhashed and the
900 * disk is marked as dead (GENHD_FL_UP cleared).
902 down_write(&disk
->lookup_sem
);
903 /* invalidate stuff */
904 disk_part_iter_init(&piter
, disk
,
905 DISK_PITER_INCL_EMPTY
| DISK_PITER_REVERSE
);
906 while ((part
= disk_part_iter_next(&piter
))) {
907 invalidate_partition(disk
, part
->partno
);
908 delete_partition(part
);
910 disk_part_iter_exit(&piter
);
912 invalidate_partition(disk
, 0);
913 set_capacity(disk
, 0);
914 disk
->flags
&= ~GENHD_FL_UP
;
915 up_write(&disk
->lookup_sem
);
917 if (!(disk
->flags
& GENHD_FL_HIDDEN
))
918 sysfs_remove_link(&disk_to_dev(disk
)->kobj
, "bdi");
921 * Unregister bdi before releasing device numbers (as they can
922 * get reused and we'd get clashes in sysfs).
924 if (!(disk
->flags
& GENHD_FL_HIDDEN
))
925 bdi_unregister(disk
->queue
->backing_dev_info
);
926 blk_unregister_queue(disk
);
931 if (!(disk
->flags
& GENHD_FL_HIDDEN
))
932 blk_unregister_region(disk_devt(disk
), disk
->minors
);
934 * Remove gendisk pointer from idr so that it cannot be looked up
935 * while RCU period before freeing gendisk is running to prevent
936 * use-after-free issues. Note that the device number stays
937 * "in-use" until we really free the gendisk.
939 blk_invalidate_devt(disk_devt(disk
));
941 kobject_put(disk
->part0
.holder_dir
);
942 kobject_put(disk
->slave_dir
);
944 part_stat_set_all(&disk
->part0
, 0);
945 disk
->part0
.stamp
= 0;
946 if (!sysfs_deprecated
)
947 sysfs_remove_link(block_depr
, dev_name(disk_to_dev(disk
)));
948 pm_runtime_set_memalloc_noio(disk_to_dev(disk
), false);
949 device_del(disk_to_dev(disk
));
951 EXPORT_SYMBOL(del_gendisk
);
953 /* sysfs access to bad-blocks list. */
954 static ssize_t
disk_badblocks_show(struct device
*dev
,
955 struct device_attribute
*attr
,
958 struct gendisk
*disk
= dev_to_disk(dev
);
961 return sprintf(page
, "\n");
963 return badblocks_show(disk
->bb
, page
, 0);
966 static ssize_t
disk_badblocks_store(struct device
*dev
,
967 struct device_attribute
*attr
,
968 const char *page
, size_t len
)
970 struct gendisk
*disk
= dev_to_disk(dev
);
975 return badblocks_store(disk
->bb
, page
, len
, 0);
979 * get_gendisk - get partitioning information for a given device
980 * @devt: device to get partitioning information for
981 * @partno: returned partition index
983 * This function gets the structure containing partitioning
984 * information for the given device @devt.
988 struct gendisk
*get_gendisk(dev_t devt
, int *partno
)
990 struct gendisk
*disk
= NULL
;
994 if (MAJOR(devt
) != BLOCK_EXT_MAJOR
) {
995 struct kobject
*kobj
;
997 kobj
= kobj_lookup(bdev_map
, devt
, partno
);
999 disk
= dev_to_disk(kobj_to_dev(kobj
));
1001 struct hd_struct
*part
;
1003 spin_lock_bh(&ext_devt_lock
);
1004 part
= idr_find(&ext_devt_idr
, blk_mangle_minor(MINOR(devt
)));
1005 if (part
&& get_disk_and_module(part_to_disk(part
))) {
1006 *partno
= part
->partno
;
1007 disk
= part_to_disk(part
);
1009 spin_unlock_bh(&ext_devt_lock
);
1016 * Synchronize with del_gendisk() to not return disk that is being
1019 down_read(&disk
->lookup_sem
);
1020 if (unlikely((disk
->flags
& GENHD_FL_HIDDEN
) ||
1021 !(disk
->flags
& GENHD_FL_UP
))) {
1022 up_read(&disk
->lookup_sem
);
1023 put_disk_and_module(disk
);
1026 up_read(&disk
->lookup_sem
);
1032 * bdget_disk - do bdget() by gendisk and partition number
1033 * @disk: gendisk of interest
1034 * @partno: partition number
1036 * Find partition @partno from @disk, do bdget() on it.
1042 * Resulting block_device on success, NULL on failure.
1044 struct block_device
*bdget_disk(struct gendisk
*disk
, int partno
)
1046 struct hd_struct
*part
;
1047 struct block_device
*bdev
= NULL
;
1049 part
= disk_get_part(disk
, partno
);
1051 bdev
= bdget_part(part
);
1052 disk_put_part(part
);
1056 EXPORT_SYMBOL(bdget_disk
);
1059 * print a full list of all partitions - intended for places where the root
1060 * filesystem can't be mounted and thus to give the victim some idea of what
1063 void __init
printk_all_partitions(void)
1065 struct class_dev_iter iter
;
1068 class_dev_iter_init(&iter
, &block_class
, NULL
, &disk_type
);
1069 while ((dev
= class_dev_iter_next(&iter
))) {
1070 struct gendisk
*disk
= dev_to_disk(dev
);
1071 struct disk_part_iter piter
;
1072 struct hd_struct
*part
;
1073 char name_buf
[BDEVNAME_SIZE
];
1074 char devt_buf
[BDEVT_SIZE
];
1077 * Don't show empty devices or things that have been
1080 if (get_capacity(disk
) == 0 ||
1081 (disk
->flags
& GENHD_FL_SUPPRESS_PARTITION_INFO
))
1085 * Note, unlike /proc/partitions, I am showing the
1086 * numbers in hex - the same format as the root=
1089 disk_part_iter_init(&piter
, disk
, DISK_PITER_INCL_PART0
);
1090 while ((part
= disk_part_iter_next(&piter
))) {
1091 bool is_part0
= part
== &disk
->part0
;
1093 printk("%s%s %10llu %s %s", is_part0
? "" : " ",
1094 bdevt_str(part_devt(part
), devt_buf
),
1095 (unsigned long long)part_nr_sects_read(part
) >> 1
1096 , disk_name(disk
, part
->partno
, name_buf
),
1097 part
->info
? part
->info
->uuid
: "");
1099 if (dev
->parent
&& dev
->parent
->driver
)
1100 printk(" driver: %s\n",
1101 dev
->parent
->driver
->name
);
1103 printk(" (driver?)\n");
1107 disk_part_iter_exit(&piter
);
1109 class_dev_iter_exit(&iter
);
1112 #ifdef CONFIG_PROC_FS
1114 static void *disk_seqf_start(struct seq_file
*seqf
, loff_t
*pos
)
1117 struct class_dev_iter
*iter
;
1120 iter
= kmalloc(sizeof(*iter
), GFP_KERNEL
);
1122 return ERR_PTR(-ENOMEM
);
1124 seqf
->private = iter
;
1125 class_dev_iter_init(iter
, &block_class
, NULL
, &disk_type
);
1127 dev
= class_dev_iter_next(iter
);
1132 return dev_to_disk(dev
);
1135 static void *disk_seqf_next(struct seq_file
*seqf
, void *v
, loff_t
*pos
)
1140 dev
= class_dev_iter_next(seqf
->private);
1142 return dev_to_disk(dev
);
1147 static void disk_seqf_stop(struct seq_file
*seqf
, void *v
)
1149 struct class_dev_iter
*iter
= seqf
->private;
1151 /* stop is called even after start failed :-( */
1153 class_dev_iter_exit(iter
);
1155 seqf
->private = NULL
;
1159 static void *show_partition_start(struct seq_file
*seqf
, loff_t
*pos
)
1163 p
= disk_seqf_start(seqf
, pos
);
1164 if (!IS_ERR_OR_NULL(p
) && !*pos
)
1165 seq_puts(seqf
, "major minor #blocks name\n\n");
1169 static int show_partition(struct seq_file
*seqf
, void *v
)
1171 struct gendisk
*sgp
= v
;
1172 struct disk_part_iter piter
;
1173 struct hd_struct
*part
;
1174 char buf
[BDEVNAME_SIZE
];
1176 /* Don't show non-partitionable removeable devices or empty devices */
1177 if (!get_capacity(sgp
) || (!disk_max_parts(sgp
) &&
1178 (sgp
->flags
& GENHD_FL_REMOVABLE
)))
1180 if (sgp
->flags
& GENHD_FL_SUPPRESS_PARTITION_INFO
)
1183 /* show the full disk and all non-0 size partitions of it */
1184 disk_part_iter_init(&piter
, sgp
, DISK_PITER_INCL_PART0
);
1185 while ((part
= disk_part_iter_next(&piter
)))
1186 seq_printf(seqf
, "%4d %7d %10llu %s\n",
1187 MAJOR(part_devt(part
)), MINOR(part_devt(part
)),
1188 (unsigned long long)part_nr_sects_read(part
) >> 1,
1189 disk_name(sgp
, part
->partno
, buf
));
1190 disk_part_iter_exit(&piter
);
1195 static const struct seq_operations partitions_op
= {
1196 .start
= show_partition_start
,
1197 .next
= disk_seqf_next
,
1198 .stop
= disk_seqf_stop
,
1199 .show
= show_partition
1204 static struct kobject
*base_probe(dev_t devt
, int *partno
, void *data
)
1206 if (request_module("block-major-%d-%d", MAJOR(devt
), MINOR(devt
)) > 0)
1207 /* Make old-style 2.4 aliases work */
1208 request_module("block-major-%d", MAJOR(devt
));
1212 static int __init
genhd_device_init(void)
1216 block_class
.dev_kobj
= sysfs_dev_block_kobj
;
1217 error
= class_register(&block_class
);
1218 if (unlikely(error
))
1220 bdev_map
= kobj_map_init(base_probe
, &block_class_lock
);
1223 register_blkdev(BLOCK_EXT_MAJOR
, "blkext");
1225 /* create top-level block dir */
1226 if (!sysfs_deprecated
)
1227 block_depr
= kobject_create_and_add("block", NULL
);
1231 subsys_initcall(genhd_device_init
);
1233 static ssize_t
disk_range_show(struct device
*dev
,
1234 struct device_attribute
*attr
, char *buf
)
1236 struct gendisk
*disk
= dev_to_disk(dev
);
1238 return sprintf(buf
, "%d\n", disk
->minors
);
1241 static ssize_t
disk_ext_range_show(struct device
*dev
,
1242 struct device_attribute
*attr
, char *buf
)
1244 struct gendisk
*disk
= dev_to_disk(dev
);
1246 return sprintf(buf
, "%d\n", disk_max_parts(disk
));
1249 static ssize_t
disk_removable_show(struct device
*dev
,
1250 struct device_attribute
*attr
, char *buf
)
1252 struct gendisk
*disk
= dev_to_disk(dev
);
1254 return sprintf(buf
, "%d\n",
1255 (disk
->flags
& GENHD_FL_REMOVABLE
? 1 : 0));
1258 static ssize_t
disk_hidden_show(struct device
*dev
,
1259 struct device_attribute
*attr
, char *buf
)
1261 struct gendisk
*disk
= dev_to_disk(dev
);
1263 return sprintf(buf
, "%d\n",
1264 (disk
->flags
& GENHD_FL_HIDDEN
? 1 : 0));
1267 static ssize_t
disk_ro_show(struct device
*dev
,
1268 struct device_attribute
*attr
, char *buf
)
1270 struct gendisk
*disk
= dev_to_disk(dev
);
1272 return sprintf(buf
, "%d\n", get_disk_ro(disk
) ? 1 : 0);
1275 ssize_t
part_size_show(struct device
*dev
,
1276 struct device_attribute
*attr
, char *buf
)
1278 struct hd_struct
*p
= dev_to_part(dev
);
1280 return sprintf(buf
, "%llu\n",
1281 (unsigned long long)part_nr_sects_read(p
));
1284 ssize_t
part_stat_show(struct device
*dev
,
1285 struct device_attribute
*attr
, char *buf
)
1287 struct hd_struct
*p
= dev_to_part(dev
);
1288 struct request_queue
*q
= part_to_disk(p
)->queue
;
1289 struct disk_stats stat
;
1290 unsigned int inflight
;
1292 part_stat_read_all(p
, &stat
);
1294 inflight
= blk_mq_in_flight(q
, p
);
1296 inflight
= part_in_flight(p
);
1299 "%8lu %8lu %8llu %8u "
1300 "%8lu %8lu %8llu %8u "
1302 "%8lu %8lu %8llu %8u "
1305 stat
.ios
[STAT_READ
],
1306 stat
.merges
[STAT_READ
],
1307 (unsigned long long)stat
.sectors
[STAT_READ
],
1308 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
], NSEC_PER_MSEC
),
1309 stat
.ios
[STAT_WRITE
],
1310 stat
.merges
[STAT_WRITE
],
1311 (unsigned long long)stat
.sectors
[STAT_WRITE
],
1312 (unsigned int)div_u64(stat
.nsecs
[STAT_WRITE
], NSEC_PER_MSEC
),
1314 jiffies_to_msecs(stat
.io_ticks
),
1315 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
] +
1316 stat
.nsecs
[STAT_WRITE
] +
1317 stat
.nsecs
[STAT_DISCARD
] +
1318 stat
.nsecs
[STAT_FLUSH
],
1320 stat
.ios
[STAT_DISCARD
],
1321 stat
.merges
[STAT_DISCARD
],
1322 (unsigned long long)stat
.sectors
[STAT_DISCARD
],
1323 (unsigned int)div_u64(stat
.nsecs
[STAT_DISCARD
], NSEC_PER_MSEC
),
1324 stat
.ios
[STAT_FLUSH
],
1325 (unsigned int)div_u64(stat
.nsecs
[STAT_FLUSH
], NSEC_PER_MSEC
));
1328 ssize_t
part_inflight_show(struct device
*dev
, struct device_attribute
*attr
,
1331 struct hd_struct
*p
= dev_to_part(dev
);
1332 struct request_queue
*q
= part_to_disk(p
)->queue
;
1333 unsigned int inflight
[2];
1336 blk_mq_in_flight_rw(q
, p
, inflight
);
1338 part_in_flight_rw(p
, inflight
);
1340 return sprintf(buf
, "%8u %8u\n", inflight
[0], inflight
[1]);
1343 static ssize_t
disk_capability_show(struct device
*dev
,
1344 struct device_attribute
*attr
, char *buf
)
1346 struct gendisk
*disk
= dev_to_disk(dev
);
1348 return sprintf(buf
, "%x\n", disk
->flags
);
1351 static ssize_t
disk_alignment_offset_show(struct device
*dev
,
1352 struct device_attribute
*attr
,
1355 struct gendisk
*disk
= dev_to_disk(dev
);
1357 return sprintf(buf
, "%d\n", queue_alignment_offset(disk
->queue
));
1360 static ssize_t
disk_discard_alignment_show(struct device
*dev
,
1361 struct device_attribute
*attr
,
1364 struct gendisk
*disk
= dev_to_disk(dev
);
1366 return sprintf(buf
, "%d\n", queue_discard_alignment(disk
->queue
));
1369 static DEVICE_ATTR(range
, 0444, disk_range_show
, NULL
);
1370 static DEVICE_ATTR(ext_range
, 0444, disk_ext_range_show
, NULL
);
1371 static DEVICE_ATTR(removable
, 0444, disk_removable_show
, NULL
);
1372 static DEVICE_ATTR(hidden
, 0444, disk_hidden_show
, NULL
);
1373 static DEVICE_ATTR(ro
, 0444, disk_ro_show
, NULL
);
1374 static DEVICE_ATTR(size
, 0444, part_size_show
, NULL
);
1375 static DEVICE_ATTR(alignment_offset
, 0444, disk_alignment_offset_show
, NULL
);
1376 static DEVICE_ATTR(discard_alignment
, 0444, disk_discard_alignment_show
, NULL
);
1377 static DEVICE_ATTR(capability
, 0444, disk_capability_show
, NULL
);
1378 static DEVICE_ATTR(stat
, 0444, part_stat_show
, NULL
);
1379 static DEVICE_ATTR(inflight
, 0444, part_inflight_show
, NULL
);
1380 static DEVICE_ATTR(badblocks
, 0644, disk_badblocks_show
, disk_badblocks_store
);
1382 #ifdef CONFIG_FAIL_MAKE_REQUEST
1383 ssize_t
part_fail_show(struct device
*dev
,
1384 struct device_attribute
*attr
, char *buf
)
1386 struct hd_struct
*p
= dev_to_part(dev
);
1388 return sprintf(buf
, "%d\n", p
->make_it_fail
);
1391 ssize_t
part_fail_store(struct device
*dev
,
1392 struct device_attribute
*attr
,
1393 const char *buf
, size_t count
)
1395 struct hd_struct
*p
= dev_to_part(dev
);
1398 if (count
> 0 && sscanf(buf
, "%d", &i
) > 0)
1399 p
->make_it_fail
= (i
== 0) ? 0 : 1;
1404 static struct device_attribute dev_attr_fail
=
1405 __ATTR(make
-it
-fail
, 0644, part_fail_show
, part_fail_store
);
1406 #endif /* CONFIG_FAIL_MAKE_REQUEST */
1408 #ifdef CONFIG_FAIL_IO_TIMEOUT
1409 static struct device_attribute dev_attr_fail_timeout
=
1410 __ATTR(io
-timeout
-fail
, 0644, part_timeout_show
, part_timeout_store
);
1413 static struct attribute
*disk_attrs
[] = {
1414 &dev_attr_range
.attr
,
1415 &dev_attr_ext_range
.attr
,
1416 &dev_attr_removable
.attr
,
1417 &dev_attr_hidden
.attr
,
1419 &dev_attr_size
.attr
,
1420 &dev_attr_alignment_offset
.attr
,
1421 &dev_attr_discard_alignment
.attr
,
1422 &dev_attr_capability
.attr
,
1423 &dev_attr_stat
.attr
,
1424 &dev_attr_inflight
.attr
,
1425 &dev_attr_badblocks
.attr
,
1426 #ifdef CONFIG_FAIL_MAKE_REQUEST
1427 &dev_attr_fail
.attr
,
1429 #ifdef CONFIG_FAIL_IO_TIMEOUT
1430 &dev_attr_fail_timeout
.attr
,
1435 static umode_t
disk_visible(struct kobject
*kobj
, struct attribute
*a
, int n
)
1437 struct device
*dev
= container_of(kobj
, typeof(*dev
), kobj
);
1438 struct gendisk
*disk
= dev_to_disk(dev
);
1440 if (a
== &dev_attr_badblocks
.attr
&& !disk
->bb
)
1445 static struct attribute_group disk_attr_group
= {
1446 .attrs
= disk_attrs
,
1447 .is_visible
= disk_visible
,
1450 static const struct attribute_group
*disk_attr_groups
[] = {
1456 * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
1457 * @disk: disk to replace part_tbl for
1458 * @new_ptbl: new part_tbl to install
1460 * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The
1461 * original ptbl is freed using RCU callback.
1464 * Matching bd_mutex locked or the caller is the only user of @disk.
1466 static void disk_replace_part_tbl(struct gendisk
*disk
,
1467 struct disk_part_tbl
*new_ptbl
)
1469 struct disk_part_tbl
*old_ptbl
=
1470 rcu_dereference_protected(disk
->part_tbl
, 1);
1472 rcu_assign_pointer(disk
->part_tbl
, new_ptbl
);
1475 rcu_assign_pointer(old_ptbl
->last_lookup
, NULL
);
1476 kfree_rcu(old_ptbl
, rcu_head
);
1481 * disk_expand_part_tbl - expand disk->part_tbl
1482 * @disk: disk to expand part_tbl for
1483 * @partno: expand such that this partno can fit in
1485 * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl
1486 * uses RCU to allow unlocked dereferencing for stats and other stuff.
1489 * Matching bd_mutex locked or the caller is the only user of @disk.
1493 * 0 on success, -errno on failure.
1495 int disk_expand_part_tbl(struct gendisk
*disk
, int partno
)
1497 struct disk_part_tbl
*old_ptbl
=
1498 rcu_dereference_protected(disk
->part_tbl
, 1);
1499 struct disk_part_tbl
*new_ptbl
;
1500 int len
= old_ptbl
? old_ptbl
->len
: 0;
1504 * check for int overflow, since we can get here from blkpg_ioctl()
1505 * with a user passed 'partno'.
1507 target
= partno
+ 1;
1511 /* disk_max_parts() is zero during initialization, ignore if so */
1512 if (disk_max_parts(disk
) && target
> disk_max_parts(disk
))
1518 new_ptbl
= kzalloc_node(struct_size(new_ptbl
, part
, target
), GFP_KERNEL
,
1523 new_ptbl
->len
= target
;
1525 for (i
= 0; i
< len
; i
++)
1526 rcu_assign_pointer(new_ptbl
->part
[i
], old_ptbl
->part
[i
]);
1528 disk_replace_part_tbl(disk
, new_ptbl
);
1533 * disk_release - releases all allocated resources of the gendisk
1534 * @dev: the device representing this disk
1536 * This function releases all allocated resources of the gendisk.
1538 * The struct gendisk refcount is incremented with get_gendisk() or
1539 * get_disk_and_module(), and its refcount is decremented with
1540 * put_disk_and_module() or put_disk(). Once the refcount reaches 0 this
1541 * function is called.
1543 * Drivers which used __device_add_disk() have a gendisk with a request_queue
1544 * assigned. Since the request_queue sits on top of the gendisk for these
1545 * drivers we also call blk_put_queue() for them, and we expect the
1546 * request_queue refcount to reach 0 at this point, and so the request_queue
1547 * will also be freed prior to the disk.
1549 * Context: can sleep
1551 static void disk_release(struct device
*dev
)
1553 struct gendisk
*disk
= dev_to_disk(dev
);
1557 blk_free_devt(dev
->devt
);
1558 disk_release_events(disk
);
1559 kfree(disk
->random
);
1560 disk_replace_part_tbl(disk
, NULL
);
1561 hd_free_part(&disk
->part0
);
1563 blk_put_queue(disk
->queue
);
1566 struct class block_class
= {
1570 static char *block_devnode(struct device
*dev
, umode_t
*mode
,
1571 kuid_t
*uid
, kgid_t
*gid
)
1573 struct gendisk
*disk
= dev_to_disk(dev
);
1575 if (disk
->fops
->devnode
)
1576 return disk
->fops
->devnode(disk
, mode
);
1580 const struct device_type disk_type
= {
1582 .groups
= disk_attr_groups
,
1583 .release
= disk_release
,
1584 .devnode
= block_devnode
,
1587 #ifdef CONFIG_PROC_FS
1589 * aggregate disk stat collector. Uses the same stats that the sysfs
1590 * entries do, above, but makes them available through one seq_file.
1592 * The output looks suspiciously like /proc/partitions with a bunch of
1595 static int diskstats_show(struct seq_file
*seqf
, void *v
)
1597 struct gendisk
*gp
= v
;
1598 struct disk_part_iter piter
;
1599 struct hd_struct
*hd
;
1600 char buf
[BDEVNAME_SIZE
];
1601 unsigned int inflight
;
1602 struct disk_stats stat
;
1605 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1606 seq_puts(seqf, "major minor name"
1607 " rio rmerge rsect ruse wio wmerge "
1608 "wsect wuse running use aveq"
1612 disk_part_iter_init(&piter
, gp
, DISK_PITER_INCL_EMPTY_PART0
);
1613 while ((hd
= disk_part_iter_next(&piter
))) {
1614 part_stat_read_all(hd
, &stat
);
1615 if (queue_is_mq(gp
->queue
))
1616 inflight
= blk_mq_in_flight(gp
->queue
, hd
);
1618 inflight
= part_in_flight(hd
);
1620 seq_printf(seqf
, "%4d %7d %s "
1627 MAJOR(part_devt(hd
)), MINOR(part_devt(hd
)),
1628 disk_name(gp
, hd
->partno
, buf
),
1629 stat
.ios
[STAT_READ
],
1630 stat
.merges
[STAT_READ
],
1631 stat
.sectors
[STAT_READ
],
1632 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
],
1634 stat
.ios
[STAT_WRITE
],
1635 stat
.merges
[STAT_WRITE
],
1636 stat
.sectors
[STAT_WRITE
],
1637 (unsigned int)div_u64(stat
.nsecs
[STAT_WRITE
],
1640 jiffies_to_msecs(stat
.io_ticks
),
1641 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
] +
1642 stat
.nsecs
[STAT_WRITE
] +
1643 stat
.nsecs
[STAT_DISCARD
] +
1644 stat
.nsecs
[STAT_FLUSH
],
1646 stat
.ios
[STAT_DISCARD
],
1647 stat
.merges
[STAT_DISCARD
],
1648 stat
.sectors
[STAT_DISCARD
],
1649 (unsigned int)div_u64(stat
.nsecs
[STAT_DISCARD
],
1651 stat
.ios
[STAT_FLUSH
],
1652 (unsigned int)div_u64(stat
.nsecs
[STAT_FLUSH
],
1656 disk_part_iter_exit(&piter
);
1661 static const struct seq_operations diskstats_op
= {
1662 .start
= disk_seqf_start
,
1663 .next
= disk_seqf_next
,
1664 .stop
= disk_seqf_stop
,
1665 .show
= diskstats_show
1668 static int __init
proc_genhd_init(void)
1670 proc_create_seq("diskstats", 0, NULL
, &diskstats_op
);
1671 proc_create_seq("partitions", 0, NULL
, &partitions_op
);
1674 module_init(proc_genhd_init
);
1675 #endif /* CONFIG_PROC_FS */
1677 dev_t
blk_lookup_devt(const char *name
, int partno
)
1679 dev_t devt
= MKDEV(0, 0);
1680 struct class_dev_iter iter
;
1683 class_dev_iter_init(&iter
, &block_class
, NULL
, &disk_type
);
1684 while ((dev
= class_dev_iter_next(&iter
))) {
1685 struct gendisk
*disk
= dev_to_disk(dev
);
1686 struct hd_struct
*part
;
1688 if (strcmp(dev_name(dev
), name
))
1691 if (partno
< disk
->minors
) {
1692 /* We need to return the right devno, even
1693 * if the partition doesn't exist yet.
1695 devt
= MKDEV(MAJOR(dev
->devt
),
1696 MINOR(dev
->devt
) + partno
);
1699 part
= disk_get_part(disk
, partno
);
1701 devt
= part_devt(part
);
1702 disk_put_part(part
);
1705 disk_put_part(part
);
1707 class_dev_iter_exit(&iter
);
1711 struct gendisk
*__alloc_disk_node(int minors
, int node_id
)
1713 struct gendisk
*disk
;
1714 struct disk_part_tbl
*ptbl
;
1716 if (minors
> DISK_MAX_PARTS
) {
1718 "block: can't allocate more than %d partitions\n",
1720 minors
= DISK_MAX_PARTS
;
1723 disk
= kzalloc_node(sizeof(struct gendisk
), GFP_KERNEL
, node_id
);
1727 disk
->part0
.dkstats
= alloc_percpu(struct disk_stats
);
1728 if (!disk
->part0
.dkstats
)
1731 init_rwsem(&disk
->lookup_sem
);
1732 disk
->node_id
= node_id
;
1733 if (disk_expand_part_tbl(disk
, 0)) {
1734 free_percpu(disk
->part0
.dkstats
);
1738 ptbl
= rcu_dereference_protected(disk
->part_tbl
, 1);
1739 rcu_assign_pointer(ptbl
->part
[0], &disk
->part0
);
1742 * set_capacity() and get_capacity() currently don't use
1743 * seqcounter to read/update the part0->nr_sects. Still init
1744 * the counter as we can read the sectors in IO submission
1745 * patch using seqence counters.
1747 * TODO: Ideally set_capacity() and get_capacity() should be
1748 * converted to make use of bd_mutex and sequence counters.
1750 hd_sects_seq_init(&disk
->part0
);
1751 if (hd_ref_init(&disk
->part0
))
1752 goto out_free_part0
;
1754 disk
->minors
= minors
;
1755 rand_initialize_disk(disk
);
1756 disk_to_dev(disk
)->class = &block_class
;
1757 disk_to_dev(disk
)->type
= &disk_type
;
1758 device_initialize(disk_to_dev(disk
));
1762 hd_free_part(&disk
->part0
);
1767 EXPORT_SYMBOL(__alloc_disk_node
);
1770 * get_disk_and_module - increments the gendisk and gendisk fops module refcount
1771 * @disk: the struct gendisk to increment the refcount for
1773 * This increments the refcount for the struct gendisk, and the gendisk's
1774 * fops module owner.
1776 * Context: Any context.
1778 struct kobject
*get_disk_and_module(struct gendisk
*disk
)
1780 struct module
*owner
;
1781 struct kobject
*kobj
;
1785 owner
= disk
->fops
->owner
;
1786 if (owner
&& !try_module_get(owner
))
1788 kobj
= kobject_get_unless_zero(&disk_to_dev(disk
)->kobj
);
1796 EXPORT_SYMBOL(get_disk_and_module
);
1799 * put_disk - decrements the gendisk refcount
1800 * @disk: the struct gendisk to decrement the refcount for
1802 * This decrements the refcount for the struct gendisk. When this reaches 0
1803 * we'll have disk_release() called.
1805 * Context: Any context, but the last reference must not be dropped from
1808 void put_disk(struct gendisk
*disk
)
1811 kobject_put(&disk_to_dev(disk
)->kobj
);
1813 EXPORT_SYMBOL(put_disk
);
1816 * put_disk_and_module - decrements the module and gendisk refcount
1817 * @disk: the struct gendisk to decrement the refcount for
1819 * This is a counterpart of get_disk_and_module() and thus also of
1822 * Context: Any context, but the last reference must not be dropped from
1825 void put_disk_and_module(struct gendisk
*disk
)
1828 struct module
*owner
= disk
->fops
->owner
;
1834 EXPORT_SYMBOL(put_disk_and_module
);
1836 static void set_disk_ro_uevent(struct gendisk
*gd
, int ro
)
1838 char event
[] = "DISK_RO=1";
1839 char *envp
[] = { event
, NULL
};
1843 kobject_uevent_env(&disk_to_dev(gd
)->kobj
, KOBJ_CHANGE
, envp
);
1846 void set_device_ro(struct block_device
*bdev
, int flag
)
1848 bdev
->bd_part
->policy
= flag
;
1851 EXPORT_SYMBOL(set_device_ro
);
1853 void set_disk_ro(struct gendisk
*disk
, int flag
)
1855 struct disk_part_iter piter
;
1856 struct hd_struct
*part
;
1858 if (disk
->part0
.policy
!= flag
) {
1859 set_disk_ro_uevent(disk
, flag
);
1860 disk
->part0
.policy
= flag
;
1863 disk_part_iter_init(&piter
, disk
, DISK_PITER_INCL_EMPTY
);
1864 while ((part
= disk_part_iter_next(&piter
)))
1865 part
->policy
= flag
;
1866 disk_part_iter_exit(&piter
);
1869 EXPORT_SYMBOL(set_disk_ro
);
1871 int bdev_read_only(struct block_device
*bdev
)
1875 return bdev
->bd_part
->policy
;
1878 EXPORT_SYMBOL(bdev_read_only
);
1881 * Disk events - monitor disk events like media change and eject request.
1883 struct disk_events
{
1884 struct list_head node
; /* all disk_event's */
1885 struct gendisk
*disk
; /* the associated disk */
1888 struct mutex block_mutex
; /* protects blocking */
1889 int block
; /* event blocking depth */
1890 unsigned int pending
; /* events already sent out */
1891 unsigned int clearing
; /* events being cleared */
1893 long poll_msecs
; /* interval, -1 for default */
1894 struct delayed_work dwork
;
1897 static const char *disk_events_strs
[] = {
1898 [ilog2(DISK_EVENT_MEDIA_CHANGE
)] = "media_change",
1899 [ilog2(DISK_EVENT_EJECT_REQUEST
)] = "eject_request",
1902 static char *disk_uevents
[] = {
1903 [ilog2(DISK_EVENT_MEDIA_CHANGE
)] = "DISK_MEDIA_CHANGE=1",
1904 [ilog2(DISK_EVENT_EJECT_REQUEST
)] = "DISK_EJECT_REQUEST=1",
1907 /* list of all disk_events */
1908 static DEFINE_MUTEX(disk_events_mutex
);
1909 static LIST_HEAD(disk_events
);
1911 /* disable in-kernel polling by default */
1912 static unsigned long disk_events_dfl_poll_msecs
;
1914 static unsigned long disk_events_poll_jiffies(struct gendisk
*disk
)
1916 struct disk_events
*ev
= disk
->ev
;
1917 long intv_msecs
= 0;
1920 * If device-specific poll interval is set, always use it. If
1921 * the default is being used, poll if the POLL flag is set.
1923 if (ev
->poll_msecs
>= 0)
1924 intv_msecs
= ev
->poll_msecs
;
1925 else if (disk
->event_flags
& DISK_EVENT_FLAG_POLL
)
1926 intv_msecs
= disk_events_dfl_poll_msecs
;
1928 return msecs_to_jiffies(intv_msecs
);
1932 * disk_block_events - block and flush disk event checking
1933 * @disk: disk to block events for
1935 * On return from this function, it is guaranteed that event checking
1936 * isn't in progress and won't happen until unblocked by
1937 * disk_unblock_events(). Events blocking is counted and the actual
1938 * unblocking happens after the matching number of unblocks are done.
1940 * Note that this intentionally does not block event checking from
1941 * disk_clear_events().
1946 void disk_block_events(struct gendisk
*disk
)
1948 struct disk_events
*ev
= disk
->ev
;
1949 unsigned long flags
;
1956 * Outer mutex ensures that the first blocker completes canceling
1957 * the event work before further blockers are allowed to finish.
1959 mutex_lock(&ev
->block_mutex
);
1961 spin_lock_irqsave(&ev
->lock
, flags
);
1962 cancel
= !ev
->block
++;
1963 spin_unlock_irqrestore(&ev
->lock
, flags
);
1966 cancel_delayed_work_sync(&disk
->ev
->dwork
);
1968 mutex_unlock(&ev
->block_mutex
);
1971 static void __disk_unblock_events(struct gendisk
*disk
, bool check_now
)
1973 struct disk_events
*ev
= disk
->ev
;
1975 unsigned long flags
;
1977 spin_lock_irqsave(&ev
->lock
, flags
);
1979 if (WARN_ON_ONCE(ev
->block
<= 0))
1985 intv
= disk_events_poll_jiffies(disk
);
1987 queue_delayed_work(system_freezable_power_efficient_wq
,
1990 queue_delayed_work(system_freezable_power_efficient_wq
,
1993 spin_unlock_irqrestore(&ev
->lock
, flags
);
1997 * disk_unblock_events - unblock disk event checking
1998 * @disk: disk to unblock events for
2000 * Undo disk_block_events(). When the block count reaches zero, it
2001 * starts events polling if configured.
2004 * Don't care. Safe to call from irq context.
2006 void disk_unblock_events(struct gendisk
*disk
)
2009 __disk_unblock_events(disk
, false);
2013 * disk_flush_events - schedule immediate event checking and flushing
2014 * @disk: disk to check and flush events for
2015 * @mask: events to flush
2017 * Schedule immediate event checking on @disk if not blocked. Events in
2018 * @mask are scheduled to be cleared from the driver. Note that this
2019 * doesn't clear the events from @disk->ev.
2022 * If @mask is non-zero must be called with bdev->bd_mutex held.
2024 void disk_flush_events(struct gendisk
*disk
, unsigned int mask
)
2026 struct disk_events
*ev
= disk
->ev
;
2031 spin_lock_irq(&ev
->lock
);
2032 ev
->clearing
|= mask
;
2034 mod_delayed_work(system_freezable_power_efficient_wq
,
2036 spin_unlock_irq(&ev
->lock
);
2040 * disk_clear_events - synchronously check, clear and return pending events
2041 * @disk: disk to fetch and clear events from
2042 * @mask: mask of events to be fetched and cleared
2044 * Disk events are synchronously checked and pending events in @mask
2045 * are cleared and returned. This ignores the block count.
2050 static unsigned int disk_clear_events(struct gendisk
*disk
, unsigned int mask
)
2052 struct disk_events
*ev
= disk
->ev
;
2053 unsigned int pending
;
2054 unsigned int clearing
= mask
;
2059 disk_block_events(disk
);
2062 * store the union of mask and ev->clearing on the stack so that the
2063 * race with disk_flush_events does not cause ambiguity (ev->clearing
2064 * can still be modified even if events are blocked).
2066 spin_lock_irq(&ev
->lock
);
2067 clearing
|= ev
->clearing
;
2069 spin_unlock_irq(&ev
->lock
);
2071 disk_check_events(ev
, &clearing
);
2073 * if ev->clearing is not 0, the disk_flush_events got called in the
2074 * middle of this function, so we want to run the workfn without delay.
2076 __disk_unblock_events(disk
, ev
->clearing
? true : false);
2078 /* then, fetch and clear pending events */
2079 spin_lock_irq(&ev
->lock
);
2080 pending
= ev
->pending
& mask
;
2081 ev
->pending
&= ~mask
;
2082 spin_unlock_irq(&ev
->lock
);
2083 WARN_ON_ONCE(clearing
& mask
);
2089 * bdev_check_media_change - check if a removable media has been changed
2090 * @bdev: block device to check
2092 * Check whether a removable media has been changed, and attempt to free all
2093 * dentries and inodes and invalidates all block device page cache entries in
2096 * Returns %true if the block device changed, or %false if not.
2098 bool bdev_check_media_change(struct block_device
*bdev
)
2100 unsigned int events
;
2102 events
= disk_clear_events(bdev
->bd_disk
, DISK_EVENT_MEDIA_CHANGE
|
2103 DISK_EVENT_EJECT_REQUEST
);
2104 if (!(events
& DISK_EVENT_MEDIA_CHANGE
))
2107 if (__invalidate_device(bdev
, true))
2108 pr_warn("VFS: busy inodes on changed media %s\n",
2109 bdev
->bd_disk
->disk_name
);
2110 set_bit(GD_NEED_PART_SCAN
, &bdev
->bd_disk
->state
);
2113 EXPORT_SYMBOL(bdev_check_media_change
);
2116 * Separate this part out so that a different pointer for clearing_ptr can be
2117 * passed in for disk_clear_events.
2119 static void disk_events_workfn(struct work_struct
*work
)
2121 struct delayed_work
*dwork
= to_delayed_work(work
);
2122 struct disk_events
*ev
= container_of(dwork
, struct disk_events
, dwork
);
2124 disk_check_events(ev
, &ev
->clearing
);
2127 static void disk_check_events(struct disk_events
*ev
,
2128 unsigned int *clearing_ptr
)
2130 struct gendisk
*disk
= ev
->disk
;
2131 char *envp
[ARRAY_SIZE(disk_uevents
) + 1] = { };
2132 unsigned int clearing
= *clearing_ptr
;
2133 unsigned int events
;
2135 int nr_events
= 0, i
;
2138 events
= disk
->fops
->check_events(disk
, clearing
);
2140 /* accumulate pending events and schedule next poll if necessary */
2141 spin_lock_irq(&ev
->lock
);
2143 events
&= ~ev
->pending
;
2144 ev
->pending
|= events
;
2145 *clearing_ptr
&= ~clearing
;
2147 intv
= disk_events_poll_jiffies(disk
);
2148 if (!ev
->block
&& intv
)
2149 queue_delayed_work(system_freezable_power_efficient_wq
,
2152 spin_unlock_irq(&ev
->lock
);
2155 * Tell userland about new events. Only the events listed in
2156 * @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT
2157 * is set. Otherwise, events are processed internally but never
2158 * get reported to userland.
2160 for (i
= 0; i
< ARRAY_SIZE(disk_uevents
); i
++)
2161 if ((events
& disk
->events
& (1 << i
)) &&
2162 (disk
->event_flags
& DISK_EVENT_FLAG_UEVENT
))
2163 envp
[nr_events
++] = disk_uevents
[i
];
2166 kobject_uevent_env(&disk_to_dev(disk
)->kobj
, KOBJ_CHANGE
, envp
);
2170 * A disk events enabled device has the following sysfs nodes under
2171 * its /sys/block/X/ directory.
2173 * events : list of all supported events
2174 * events_async : list of events which can be detected w/o polling
2175 * (always empty, only for backwards compatibility)
2176 * events_poll_msecs : polling interval, 0: disable, -1: system default
2178 static ssize_t
__disk_events_show(unsigned int events
, char *buf
)
2180 const char *delim
= "";
2184 for (i
= 0; i
< ARRAY_SIZE(disk_events_strs
); i
++)
2185 if (events
& (1 << i
)) {
2186 pos
+= sprintf(buf
+ pos
, "%s%s",
2187 delim
, disk_events_strs
[i
]);
2191 pos
+= sprintf(buf
+ pos
, "\n");
2195 static ssize_t
disk_events_show(struct device
*dev
,
2196 struct device_attribute
*attr
, char *buf
)
2198 struct gendisk
*disk
= dev_to_disk(dev
);
2200 if (!(disk
->event_flags
& DISK_EVENT_FLAG_UEVENT
))
2203 return __disk_events_show(disk
->events
, buf
);
2206 static ssize_t
disk_events_async_show(struct device
*dev
,
2207 struct device_attribute
*attr
, char *buf
)
2212 static ssize_t
disk_events_poll_msecs_show(struct device
*dev
,
2213 struct device_attribute
*attr
,
2216 struct gendisk
*disk
= dev_to_disk(dev
);
2219 return sprintf(buf
, "-1\n");
2221 return sprintf(buf
, "%ld\n", disk
->ev
->poll_msecs
);
2224 static ssize_t
disk_events_poll_msecs_store(struct device
*dev
,
2225 struct device_attribute
*attr
,
2226 const char *buf
, size_t count
)
2228 struct gendisk
*disk
= dev_to_disk(dev
);
2231 if (!count
|| !sscanf(buf
, "%ld", &intv
))
2234 if (intv
< 0 && intv
!= -1)
2240 disk_block_events(disk
);
2241 disk
->ev
->poll_msecs
= intv
;
2242 __disk_unblock_events(disk
, true);
2247 static const DEVICE_ATTR(events
, 0444, disk_events_show
, NULL
);
2248 static const DEVICE_ATTR(events_async
, 0444, disk_events_async_show
, NULL
);
2249 static const DEVICE_ATTR(events_poll_msecs
, 0644,
2250 disk_events_poll_msecs_show
,
2251 disk_events_poll_msecs_store
);
2253 static const struct attribute
*disk_events_attrs
[] = {
2254 &dev_attr_events
.attr
,
2255 &dev_attr_events_async
.attr
,
2256 &dev_attr_events_poll_msecs
.attr
,
2261 * The default polling interval can be specified by the kernel
2262 * parameter block.events_dfl_poll_msecs which defaults to 0
2263 * (disable). This can also be modified runtime by writing to
2264 * /sys/module/block/parameters/events_dfl_poll_msecs.
2266 static int disk_events_set_dfl_poll_msecs(const char *val
,
2267 const struct kernel_param
*kp
)
2269 struct disk_events
*ev
;
2272 ret
= param_set_ulong(val
, kp
);
2276 mutex_lock(&disk_events_mutex
);
2278 list_for_each_entry(ev
, &disk_events
, node
)
2279 disk_flush_events(ev
->disk
, 0);
2281 mutex_unlock(&disk_events_mutex
);
2286 static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops
= {
2287 .set
= disk_events_set_dfl_poll_msecs
,
2288 .get
= param_get_ulong
,
2291 #undef MODULE_PARAM_PREFIX
2292 #define MODULE_PARAM_PREFIX "block."
2294 module_param_cb(events_dfl_poll_msecs
, &disk_events_dfl_poll_msecs_param_ops
,
2295 &disk_events_dfl_poll_msecs
, 0644);
2298 * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
2300 static void disk_alloc_events(struct gendisk
*disk
)
2302 struct disk_events
*ev
;
2304 if (!disk
->fops
->check_events
|| !disk
->events
)
2307 ev
= kzalloc(sizeof(*ev
), GFP_KERNEL
);
2309 pr_warn("%s: failed to initialize events\n", disk
->disk_name
);
2313 INIT_LIST_HEAD(&ev
->node
);
2315 spin_lock_init(&ev
->lock
);
2316 mutex_init(&ev
->block_mutex
);
2318 ev
->poll_msecs
= -1;
2319 INIT_DELAYED_WORK(&ev
->dwork
, disk_events_workfn
);
2324 static void disk_add_events(struct gendisk
*disk
)
2326 /* FIXME: error handling */
2327 if (sysfs_create_files(&disk_to_dev(disk
)->kobj
, disk_events_attrs
) < 0)
2328 pr_warn("%s: failed to create sysfs files for events\n",
2334 mutex_lock(&disk_events_mutex
);
2335 list_add_tail(&disk
->ev
->node
, &disk_events
);
2336 mutex_unlock(&disk_events_mutex
);
2339 * Block count is initialized to 1 and the following initial
2340 * unblock kicks it into action.
2342 __disk_unblock_events(disk
, true);
2345 static void disk_del_events(struct gendisk
*disk
)
2348 disk_block_events(disk
);
2350 mutex_lock(&disk_events_mutex
);
2351 list_del_init(&disk
->ev
->node
);
2352 mutex_unlock(&disk_events_mutex
);
2355 sysfs_remove_files(&disk_to_dev(disk
)->kobj
, disk_events_attrs
);
2358 static void disk_release_events(struct gendisk
*disk
)
2360 /* the block count should be 1 from disk_del_events() */
2361 WARN_ON_ONCE(disk
->ev
&& disk
->ev
->block
!= 1);