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 bool 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
);
71 EXPORT_SYMBOL_GPL(set_capacity_revalidate_and_notify
);
74 * Format the device name of the indicated disk into the supplied buffer and
75 * return a pointer to that same buffer for convenience.
77 char *disk_name(struct gendisk
*hd
, int partno
, char *buf
)
80 snprintf(buf
, BDEVNAME_SIZE
, "%s", hd
->disk_name
);
81 else if (isdigit(hd
->disk_name
[strlen(hd
->disk_name
)-1]))
82 snprintf(buf
, BDEVNAME_SIZE
, "%sp%d", hd
->disk_name
, partno
);
84 snprintf(buf
, BDEVNAME_SIZE
, "%s%d", hd
->disk_name
, partno
);
89 const char *bdevname(struct block_device
*bdev
, char *buf
)
91 return disk_name(bdev
->bd_disk
, bdev
->bd_partno
, buf
);
93 EXPORT_SYMBOL(bdevname
);
95 static void part_stat_read_all(struct hd_struct
*part
, struct disk_stats
*stat
)
99 memset(stat
, 0, sizeof(struct disk_stats
));
100 for_each_possible_cpu(cpu
) {
101 struct disk_stats
*ptr
= per_cpu_ptr(part
->dkstats
, cpu
);
104 for (group
= 0; group
< NR_STAT_GROUPS
; group
++) {
105 stat
->nsecs
[group
] += ptr
->nsecs
[group
];
106 stat
->sectors
[group
] += ptr
->sectors
[group
];
107 stat
->ios
[group
] += ptr
->ios
[group
];
108 stat
->merges
[group
] += ptr
->merges
[group
];
111 stat
->io_ticks
+= ptr
->io_ticks
;
115 static unsigned int part_in_flight(struct hd_struct
*part
)
117 unsigned int inflight
= 0;
120 for_each_possible_cpu(cpu
) {
121 inflight
+= part_stat_local_read_cpu(part
, in_flight
[0], cpu
) +
122 part_stat_local_read_cpu(part
, in_flight
[1], cpu
);
124 if ((int)inflight
< 0)
130 static void part_in_flight_rw(struct hd_struct
*part
, unsigned int inflight
[2])
136 for_each_possible_cpu(cpu
) {
137 inflight
[0] += part_stat_local_read_cpu(part
, in_flight
[0], cpu
);
138 inflight
[1] += part_stat_local_read_cpu(part
, in_flight
[1], cpu
);
140 if ((int)inflight
[0] < 0)
142 if ((int)inflight
[1] < 0)
146 struct hd_struct
*__disk_get_part(struct gendisk
*disk
, int partno
)
148 struct disk_part_tbl
*ptbl
= rcu_dereference(disk
->part_tbl
);
150 if (unlikely(partno
< 0 || partno
>= ptbl
->len
))
152 return rcu_dereference(ptbl
->part
[partno
]);
156 * disk_get_part - get partition
157 * @disk: disk to look partition from
158 * @partno: partition number
160 * Look for partition @partno from @disk. If found, increment
161 * reference count and return it.
167 * Pointer to the found partition on success, NULL if not found.
169 struct hd_struct
*disk_get_part(struct gendisk
*disk
, int partno
)
171 struct hd_struct
*part
;
174 part
= __disk_get_part(disk
, partno
);
176 get_device(part_to_dev(part
));
183 * disk_part_iter_init - initialize partition iterator
184 * @piter: iterator to initialize
185 * @disk: disk to iterate over
186 * @flags: DISK_PITER_* flags
188 * Initialize @piter so that it iterates over partitions of @disk.
193 void disk_part_iter_init(struct disk_part_iter
*piter
, struct gendisk
*disk
,
196 struct disk_part_tbl
*ptbl
;
199 ptbl
= rcu_dereference(disk
->part_tbl
);
204 if (flags
& DISK_PITER_REVERSE
)
205 piter
->idx
= ptbl
->len
- 1;
206 else if (flags
& (DISK_PITER_INCL_PART0
| DISK_PITER_INCL_EMPTY_PART0
))
211 piter
->flags
= flags
;
215 EXPORT_SYMBOL_GPL(disk_part_iter_init
);
218 * disk_part_iter_next - proceed iterator to the next partition and return it
219 * @piter: iterator of interest
221 * Proceed @piter to the next partition and return it.
226 struct hd_struct
*disk_part_iter_next(struct disk_part_iter
*piter
)
228 struct disk_part_tbl
*ptbl
;
231 /* put the last partition */
232 disk_put_part(piter
->part
);
237 ptbl
= rcu_dereference(piter
->disk
->part_tbl
);
239 /* determine iteration parameters */
240 if (piter
->flags
& DISK_PITER_REVERSE
) {
242 if (piter
->flags
& (DISK_PITER_INCL_PART0
|
243 DISK_PITER_INCL_EMPTY_PART0
))
252 /* iterate to the next partition */
253 for (; piter
->idx
!= end
; piter
->idx
+= inc
) {
254 struct hd_struct
*part
;
256 part
= rcu_dereference(ptbl
->part
[piter
->idx
]);
259 if (!part_nr_sects_read(part
) &&
260 !(piter
->flags
& DISK_PITER_INCL_EMPTY
) &&
261 !(piter
->flags
& DISK_PITER_INCL_EMPTY_PART0
&&
265 get_device(part_to_dev(part
));
275 EXPORT_SYMBOL_GPL(disk_part_iter_next
);
278 * disk_part_iter_exit - finish up partition iteration
279 * @piter: iter of interest
281 * Called when iteration is over. Cleans up @piter.
286 void disk_part_iter_exit(struct disk_part_iter
*piter
)
288 disk_put_part(piter
->part
);
291 EXPORT_SYMBOL_GPL(disk_part_iter_exit
);
293 static inline int sector_in_part(struct hd_struct
*part
, sector_t sector
)
295 return part
->start_sect
<= sector
&&
296 sector
< part
->start_sect
+ part_nr_sects_read(part
);
300 * disk_map_sector_rcu - map sector to partition
301 * @disk: gendisk of interest
302 * @sector: sector to map
304 * Find out which partition @sector maps to on @disk. This is
305 * primarily used for stats accounting.
308 * RCU read locked. The returned partition pointer is always valid
309 * because its refcount is grabbed except for part0, which lifetime
310 * is same with the disk.
313 * Found partition on success, part0 is returned if no partition matches
314 * or the matched partition is being deleted.
316 struct hd_struct
*disk_map_sector_rcu(struct gendisk
*disk
, sector_t sector
)
318 struct disk_part_tbl
*ptbl
;
319 struct hd_struct
*part
;
323 ptbl
= rcu_dereference(disk
->part_tbl
);
325 part
= rcu_dereference(ptbl
->last_lookup
);
326 if (part
&& sector_in_part(part
, sector
) && hd_struct_try_get(part
))
329 for (i
= 1; i
< ptbl
->len
; i
++) {
330 part
= rcu_dereference(ptbl
->part
[i
]);
332 if (part
&& sector_in_part(part
, sector
)) {
334 * only live partition can be cached for lookup,
335 * so use-after-free on cached & deleting partition
338 if (!hd_struct_try_get(part
))
340 rcu_assign_pointer(ptbl
->last_lookup
, part
);
350 EXPORT_SYMBOL_GPL(disk_map_sector_rcu
);
353 * disk_has_partitions
354 * @disk: gendisk of interest
356 * Walk through the partition table and check if valid partition exists.
362 * True if the gendisk has at least one valid non-zero size partition.
365 bool disk_has_partitions(struct gendisk
*disk
)
367 struct disk_part_tbl
*ptbl
;
372 ptbl
= rcu_dereference(disk
->part_tbl
);
374 /* Iterate partitions skipping the whole device at index 0 */
375 for (i
= 1; i
< ptbl
->len
; i
++) {
376 if (rcu_dereference(ptbl
->part
[i
])) {
386 EXPORT_SYMBOL_GPL(disk_has_partitions
);
389 * Can be deleted altogether. Later.
392 #define BLKDEV_MAJOR_HASH_SIZE 255
393 static struct blk_major_name
{
394 struct blk_major_name
*next
;
397 } *major_names
[BLKDEV_MAJOR_HASH_SIZE
];
399 /* index in the above - for now: assume no multimajor ranges */
400 static inline int major_to_index(unsigned major
)
402 return major
% BLKDEV_MAJOR_HASH_SIZE
;
405 #ifdef CONFIG_PROC_FS
406 void blkdev_show(struct seq_file
*seqf
, off_t offset
)
408 struct blk_major_name
*dp
;
410 mutex_lock(&block_class_lock
);
411 for (dp
= major_names
[major_to_index(offset
)]; dp
; dp
= dp
->next
)
412 if (dp
->major
== offset
)
413 seq_printf(seqf
, "%3d %s\n", dp
->major
, dp
->name
);
414 mutex_unlock(&block_class_lock
);
416 #endif /* CONFIG_PROC_FS */
419 * register_blkdev - register a new block device
421 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
422 * @major = 0, try to allocate any unused major number.
423 * @name: the name of the new block device as a zero terminated string
425 * The @name must be unique within the system.
427 * The return value depends on the @major input parameter:
429 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
430 * then the function returns zero on success, or a negative error code
431 * - if any unused major number was requested with @major = 0 parameter
432 * then the return value is the allocated major number in range
433 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
435 * See Documentation/admin-guide/devices.txt for the list of allocated
438 int register_blkdev(unsigned int major
, const char *name
)
440 struct blk_major_name
**n
, *p
;
443 mutex_lock(&block_class_lock
);
447 for (index
= ARRAY_SIZE(major_names
)-1; index
> 0; index
--) {
448 if (major_names
[index
] == NULL
)
453 printk("%s: failed to get major for %s\n",
462 if (major
>= BLKDEV_MAJOR_MAX
) {
463 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
464 __func__
, major
, BLKDEV_MAJOR_MAX
-1, name
);
470 p
= kmalloc(sizeof(struct blk_major_name
), GFP_KERNEL
);
477 strlcpy(p
->name
, name
, sizeof(p
->name
));
479 index
= major_to_index(major
);
481 for (n
= &major_names
[index
]; *n
; n
= &(*n
)->next
) {
482 if ((*n
)->major
== major
)
491 printk("register_blkdev: cannot get major %u for %s\n",
496 mutex_unlock(&block_class_lock
);
500 EXPORT_SYMBOL(register_blkdev
);
502 void unregister_blkdev(unsigned int major
, const char *name
)
504 struct blk_major_name
**n
;
505 struct blk_major_name
*p
= NULL
;
506 int index
= major_to_index(major
);
508 mutex_lock(&block_class_lock
);
509 for (n
= &major_names
[index
]; *n
; n
= &(*n
)->next
)
510 if ((*n
)->major
== major
)
512 if (!*n
|| strcmp((*n
)->name
, name
)) {
518 mutex_unlock(&block_class_lock
);
522 EXPORT_SYMBOL(unregister_blkdev
);
524 static struct kobj_map
*bdev_map
;
527 * blk_mangle_minor - scatter minor numbers apart
528 * @minor: minor number to mangle
530 * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
531 * is enabled. Mangling twice gives the original value.
539 static int blk_mangle_minor(int minor
)
541 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
544 for (i
= 0; i
< MINORBITS
/ 2; i
++) {
545 int low
= minor
& (1 << i
);
546 int high
= minor
& (1 << (MINORBITS
- 1 - i
));
547 int distance
= MINORBITS
- 1 - 2 * i
;
549 minor
^= low
| high
; /* clear both bits */
550 low
<<= distance
; /* swap the positions */
552 minor
|= low
| high
; /* and set */
559 * blk_alloc_devt - allocate a dev_t for a partition
560 * @part: partition to allocate dev_t for
561 * @devt: out parameter for resulting dev_t
563 * Allocate a dev_t for block device.
566 * 0 on success, allocated dev_t is returned in *@devt. -errno on
572 int blk_alloc_devt(struct hd_struct
*part
, dev_t
*devt
)
574 struct gendisk
*disk
= part_to_disk(part
);
577 /* in consecutive minor range? */
578 if (part
->partno
< disk
->minors
) {
579 *devt
= MKDEV(disk
->major
, disk
->first_minor
+ part
->partno
);
583 /* allocate ext devt */
584 idr_preload(GFP_KERNEL
);
586 spin_lock_bh(&ext_devt_lock
);
587 idx
= idr_alloc(&ext_devt_idr
, part
, 0, NR_EXT_DEVT
, GFP_NOWAIT
);
588 spin_unlock_bh(&ext_devt_lock
);
592 return idx
== -ENOSPC
? -EBUSY
: idx
;
594 *devt
= MKDEV(BLOCK_EXT_MAJOR
, blk_mangle_minor(idx
));
599 * blk_free_devt - free a dev_t
600 * @devt: dev_t to free
602 * Free @devt which was allocated using blk_alloc_devt().
607 void blk_free_devt(dev_t devt
)
609 if (devt
== MKDEV(0, 0))
612 if (MAJOR(devt
) == BLOCK_EXT_MAJOR
) {
613 spin_lock_bh(&ext_devt_lock
);
614 idr_remove(&ext_devt_idr
, blk_mangle_minor(MINOR(devt
)));
615 spin_unlock_bh(&ext_devt_lock
);
620 * We invalidate devt by assigning NULL pointer for devt in idr.
622 void blk_invalidate_devt(dev_t devt
)
624 if (MAJOR(devt
) == BLOCK_EXT_MAJOR
) {
625 spin_lock_bh(&ext_devt_lock
);
626 idr_replace(&ext_devt_idr
, NULL
, blk_mangle_minor(MINOR(devt
)));
627 spin_unlock_bh(&ext_devt_lock
);
631 static char *bdevt_str(dev_t devt
, char *buf
)
633 if (MAJOR(devt
) <= 0xff && MINOR(devt
) <= 0xff) {
634 char tbuf
[BDEVT_SIZE
];
635 snprintf(tbuf
, BDEVT_SIZE
, "%02x%02x", MAJOR(devt
), MINOR(devt
));
636 snprintf(buf
, BDEVT_SIZE
, "%-9s", tbuf
);
638 snprintf(buf
, BDEVT_SIZE
, "%03x:%05x", MAJOR(devt
), MINOR(devt
));
644 * Register device numbers dev..(dev+range-1)
645 * range must be nonzero
646 * The hash chain is sorted on range, so that subranges can override.
648 void blk_register_region(dev_t devt
, unsigned long range
, struct module
*module
,
649 struct kobject
*(*probe
)(dev_t
, int *, void *),
650 int (*lock
)(dev_t
, void *), void *data
)
652 kobj_map(bdev_map
, devt
, range
, module
, probe
, lock
, data
);
655 EXPORT_SYMBOL(blk_register_region
);
657 void blk_unregister_region(dev_t devt
, unsigned long range
)
659 kobj_unmap(bdev_map
, devt
, range
);
662 EXPORT_SYMBOL(blk_unregister_region
);
664 static struct kobject
*exact_match(dev_t devt
, int *partno
, void *data
)
666 struct gendisk
*p
= data
;
668 return &disk_to_dev(p
)->kobj
;
671 static int exact_lock(dev_t devt
, void *data
)
673 struct gendisk
*p
= data
;
675 if (!get_disk_and_module(p
))
680 static void disk_scan_partitions(struct gendisk
*disk
)
682 struct block_device
*bdev
;
684 if (!get_capacity(disk
) || !disk_part_scan_enabled(disk
))
687 set_bit(GD_NEED_PART_SCAN
, &disk
->state
);
688 bdev
= blkdev_get_by_dev(disk_devt(disk
), FMODE_READ
, NULL
);
690 blkdev_put(bdev
, FMODE_READ
);
693 static void register_disk(struct device
*parent
, struct gendisk
*disk
,
694 const struct attribute_group
**groups
)
696 struct device
*ddev
= disk_to_dev(disk
);
697 struct disk_part_iter piter
;
698 struct hd_struct
*part
;
701 ddev
->parent
= parent
;
703 dev_set_name(ddev
, "%s", disk
->disk_name
);
705 /* delay uevents, until we scanned partition table */
706 dev_set_uevent_suppress(ddev
, 1);
709 WARN_ON(ddev
->groups
);
710 ddev
->groups
= groups
;
712 if (device_add(ddev
))
714 if (!sysfs_deprecated
) {
715 err
= sysfs_create_link(block_depr
, &ddev
->kobj
,
716 kobject_name(&ddev
->kobj
));
724 * avoid probable deadlock caused by allocating memory with
725 * GFP_KERNEL in runtime_resume callback of its all ancestor
728 pm_runtime_set_memalloc_noio(ddev
, true);
730 disk
->part0
.holder_dir
= kobject_create_and_add("holders", &ddev
->kobj
);
731 disk
->slave_dir
= kobject_create_and_add("slaves", &ddev
->kobj
);
733 if (disk
->flags
& GENHD_FL_HIDDEN
) {
734 dev_set_uevent_suppress(ddev
, 0);
738 disk_scan_partitions(disk
);
740 /* announce disk after possible partitions are created */
741 dev_set_uevent_suppress(ddev
, 0);
742 kobject_uevent(&ddev
->kobj
, KOBJ_ADD
);
744 /* announce possible partitions */
745 disk_part_iter_init(&piter
, disk
, 0);
746 while ((part
= disk_part_iter_next(&piter
)))
747 kobject_uevent(&part_to_dev(part
)->kobj
, KOBJ_ADD
);
748 disk_part_iter_exit(&piter
);
750 if (disk
->queue
->backing_dev_info
->dev
) {
751 err
= sysfs_create_link(&ddev
->kobj
,
752 &disk
->queue
->backing_dev_info
->dev
->kobj
,
759 * __device_add_disk - add disk information to kernel list
760 * @parent: parent device for the disk
761 * @disk: per-device partitioning information
762 * @groups: Additional per-device sysfs groups
763 * @register_queue: register the queue if set to true
765 * This function registers the partitioning information in @disk
768 * FIXME: error handling
770 static void __device_add_disk(struct device
*parent
, struct gendisk
*disk
,
771 const struct attribute_group
**groups
,
778 * The disk queue should now be all set with enough information about
779 * the device for the elevator code to pick an adequate default
780 * elevator if one is needed, that is, for devices requesting queue
784 elevator_init_mq(disk
->queue
);
786 /* minors == 0 indicates to use ext devt from part0 and should
787 * be accompanied with EXT_DEVT flag. Make sure all
788 * parameters make sense.
790 WARN_ON(disk
->minors
&& !(disk
->major
|| disk
->first_minor
));
791 WARN_ON(!disk
->minors
&&
792 !(disk
->flags
& (GENHD_FL_EXT_DEVT
| GENHD_FL_HIDDEN
)));
794 disk
->flags
|= GENHD_FL_UP
;
796 retval
= blk_alloc_devt(&disk
->part0
, &devt
);
801 disk
->major
= MAJOR(devt
);
802 disk
->first_minor
= MINOR(devt
);
804 disk_alloc_events(disk
);
806 if (disk
->flags
& GENHD_FL_HIDDEN
) {
808 * Don't let hidden disks show up in /proc/partitions,
809 * and don't bother scanning for partitions either.
811 disk
->flags
|= GENHD_FL_SUPPRESS_PARTITION_INFO
;
812 disk
->flags
|= GENHD_FL_NO_PART_SCAN
;
814 struct backing_dev_info
*bdi
= disk
->queue
->backing_dev_info
;
815 struct device
*dev
= disk_to_dev(disk
);
818 /* Register BDI before referencing it from bdev */
820 ret
= bdi_register(bdi
, "%u:%u", MAJOR(devt
), MINOR(devt
));
822 bdi_set_owner(bdi
, dev
);
823 blk_register_region(disk_devt(disk
), disk
->minors
, NULL
,
824 exact_match
, exact_lock
, disk
);
826 register_disk(parent
, disk
, groups
);
828 blk_register_queue(disk
);
831 * Take an extra ref on queue which will be put on disk_release()
832 * so that it sticks around as long as @disk is there.
834 WARN_ON_ONCE(!blk_get_queue(disk
->queue
));
836 disk_add_events(disk
);
837 blk_integrity_add(disk
);
840 void device_add_disk(struct device
*parent
, struct gendisk
*disk
,
841 const struct attribute_group
**groups
)
844 __device_add_disk(parent
, disk
, groups
, true);
846 EXPORT_SYMBOL(device_add_disk
);
848 void device_add_disk_no_queue_reg(struct device
*parent
, struct gendisk
*disk
)
850 __device_add_disk(parent
, disk
, NULL
, false);
852 EXPORT_SYMBOL(device_add_disk_no_queue_reg
);
854 static void invalidate_partition(struct gendisk
*disk
, int partno
)
856 struct block_device
*bdev
;
858 bdev
= bdget_disk(disk
, partno
);
863 __invalidate_device(bdev
, true);
866 * Unhash the bdev inode for this device so that it gets evicted as soon
867 * as last inode reference is dropped.
869 remove_inode_hash(bdev
->bd_inode
);
874 * del_gendisk - remove the gendisk
875 * @disk: the struct gendisk to remove
877 * Removes the gendisk and all its associated resources. This deletes the
878 * partitions associated with the gendisk, and unregisters the associated
881 * This is the counter to the respective __device_add_disk() call.
883 * The final removal of the struct gendisk happens when its refcount reaches 0
884 * with put_disk(), which should be called after del_gendisk(), if
885 * __device_add_disk() was used.
887 * Drivers exist which depend on the release of the gendisk to be synchronous,
888 * it should not be deferred.
892 void del_gendisk(struct gendisk
*disk
)
894 struct disk_part_iter piter
;
895 struct hd_struct
*part
;
899 blk_integrity_del(disk
);
900 disk_del_events(disk
);
903 * Block lookups of the disk until all bdevs are unhashed and the
904 * disk is marked as dead (GENHD_FL_UP cleared).
906 down_write(&disk
->lookup_sem
);
907 /* invalidate stuff */
908 disk_part_iter_init(&piter
, disk
,
909 DISK_PITER_INCL_EMPTY
| DISK_PITER_REVERSE
);
910 while ((part
= disk_part_iter_next(&piter
))) {
911 invalidate_partition(disk
, part
->partno
);
912 delete_partition(part
);
914 disk_part_iter_exit(&piter
);
916 invalidate_partition(disk
, 0);
917 set_capacity(disk
, 0);
918 disk
->flags
&= ~GENHD_FL_UP
;
919 up_write(&disk
->lookup_sem
);
921 if (!(disk
->flags
& GENHD_FL_HIDDEN
))
922 sysfs_remove_link(&disk_to_dev(disk
)->kobj
, "bdi");
925 * Unregister bdi before releasing device numbers (as they can
926 * get reused and we'd get clashes in sysfs).
928 if (!(disk
->flags
& GENHD_FL_HIDDEN
))
929 bdi_unregister(disk
->queue
->backing_dev_info
);
930 blk_unregister_queue(disk
);
935 if (!(disk
->flags
& GENHD_FL_HIDDEN
))
936 blk_unregister_region(disk_devt(disk
), disk
->minors
);
938 * Remove gendisk pointer from idr so that it cannot be looked up
939 * while RCU period before freeing gendisk is running to prevent
940 * use-after-free issues. Note that the device number stays
941 * "in-use" until we really free the gendisk.
943 blk_invalidate_devt(disk_devt(disk
));
945 kobject_put(disk
->part0
.holder_dir
);
946 kobject_put(disk
->slave_dir
);
948 part_stat_set_all(&disk
->part0
, 0);
949 disk
->part0
.stamp
= 0;
950 if (!sysfs_deprecated
)
951 sysfs_remove_link(block_depr
, dev_name(disk_to_dev(disk
)));
952 pm_runtime_set_memalloc_noio(disk_to_dev(disk
), false);
953 device_del(disk_to_dev(disk
));
955 EXPORT_SYMBOL(del_gendisk
);
957 /* sysfs access to bad-blocks list. */
958 static ssize_t
disk_badblocks_show(struct device
*dev
,
959 struct device_attribute
*attr
,
962 struct gendisk
*disk
= dev_to_disk(dev
);
965 return sprintf(page
, "\n");
967 return badblocks_show(disk
->bb
, page
, 0);
970 static ssize_t
disk_badblocks_store(struct device
*dev
,
971 struct device_attribute
*attr
,
972 const char *page
, size_t len
)
974 struct gendisk
*disk
= dev_to_disk(dev
);
979 return badblocks_store(disk
->bb
, page
, len
, 0);
983 * get_gendisk - get partitioning information for a given device
984 * @devt: device to get partitioning information for
985 * @partno: returned partition index
987 * This function gets the structure containing partitioning
988 * information for the given device @devt.
992 struct gendisk
*get_gendisk(dev_t devt
, int *partno
)
994 struct gendisk
*disk
= NULL
;
998 if (MAJOR(devt
) != BLOCK_EXT_MAJOR
) {
999 struct kobject
*kobj
;
1001 kobj
= kobj_lookup(bdev_map
, devt
, partno
);
1003 disk
= dev_to_disk(kobj_to_dev(kobj
));
1005 struct hd_struct
*part
;
1007 spin_lock_bh(&ext_devt_lock
);
1008 part
= idr_find(&ext_devt_idr
, blk_mangle_minor(MINOR(devt
)));
1009 if (part
&& get_disk_and_module(part_to_disk(part
))) {
1010 *partno
= part
->partno
;
1011 disk
= part_to_disk(part
);
1013 spin_unlock_bh(&ext_devt_lock
);
1020 * Synchronize with del_gendisk() to not return disk that is being
1023 down_read(&disk
->lookup_sem
);
1024 if (unlikely((disk
->flags
& GENHD_FL_HIDDEN
) ||
1025 !(disk
->flags
& GENHD_FL_UP
))) {
1026 up_read(&disk
->lookup_sem
);
1027 put_disk_and_module(disk
);
1030 up_read(&disk
->lookup_sem
);
1036 * bdget_disk - do bdget() by gendisk and partition number
1037 * @disk: gendisk of interest
1038 * @partno: partition number
1040 * Find partition @partno from @disk, do bdget() on it.
1046 * Resulting block_device on success, NULL on failure.
1048 struct block_device
*bdget_disk(struct gendisk
*disk
, int partno
)
1050 struct hd_struct
*part
;
1051 struct block_device
*bdev
= NULL
;
1053 part
= disk_get_part(disk
, partno
);
1055 bdev
= bdget_part(part
);
1056 disk_put_part(part
);
1060 EXPORT_SYMBOL(bdget_disk
);
1063 * print a full list of all partitions - intended for places where the root
1064 * filesystem can't be mounted and thus to give the victim some idea of what
1067 void __init
printk_all_partitions(void)
1069 struct class_dev_iter iter
;
1072 class_dev_iter_init(&iter
, &block_class
, NULL
, &disk_type
);
1073 while ((dev
= class_dev_iter_next(&iter
))) {
1074 struct gendisk
*disk
= dev_to_disk(dev
);
1075 struct disk_part_iter piter
;
1076 struct hd_struct
*part
;
1077 char name_buf
[BDEVNAME_SIZE
];
1078 char devt_buf
[BDEVT_SIZE
];
1081 * Don't show empty devices or things that have been
1084 if (get_capacity(disk
) == 0 ||
1085 (disk
->flags
& GENHD_FL_SUPPRESS_PARTITION_INFO
))
1089 * Note, unlike /proc/partitions, I am showing the
1090 * numbers in hex - the same format as the root=
1093 disk_part_iter_init(&piter
, disk
, DISK_PITER_INCL_PART0
);
1094 while ((part
= disk_part_iter_next(&piter
))) {
1095 bool is_part0
= part
== &disk
->part0
;
1097 printk("%s%s %10llu %s %s", is_part0
? "" : " ",
1098 bdevt_str(part_devt(part
), devt_buf
),
1099 (unsigned long long)part_nr_sects_read(part
) >> 1
1100 , disk_name(disk
, part
->partno
, name_buf
),
1101 part
->info
? part
->info
->uuid
: "");
1103 if (dev
->parent
&& dev
->parent
->driver
)
1104 printk(" driver: %s\n",
1105 dev
->parent
->driver
->name
);
1107 printk(" (driver?)\n");
1111 disk_part_iter_exit(&piter
);
1113 class_dev_iter_exit(&iter
);
1116 #ifdef CONFIG_PROC_FS
1118 static void *disk_seqf_start(struct seq_file
*seqf
, loff_t
*pos
)
1121 struct class_dev_iter
*iter
;
1124 iter
= kmalloc(sizeof(*iter
), GFP_KERNEL
);
1126 return ERR_PTR(-ENOMEM
);
1128 seqf
->private = iter
;
1129 class_dev_iter_init(iter
, &block_class
, NULL
, &disk_type
);
1131 dev
= class_dev_iter_next(iter
);
1136 return dev_to_disk(dev
);
1139 static void *disk_seqf_next(struct seq_file
*seqf
, void *v
, loff_t
*pos
)
1144 dev
= class_dev_iter_next(seqf
->private);
1146 return dev_to_disk(dev
);
1151 static void disk_seqf_stop(struct seq_file
*seqf
, void *v
)
1153 struct class_dev_iter
*iter
= seqf
->private;
1155 /* stop is called even after start failed :-( */
1157 class_dev_iter_exit(iter
);
1159 seqf
->private = NULL
;
1163 static void *show_partition_start(struct seq_file
*seqf
, loff_t
*pos
)
1167 p
= disk_seqf_start(seqf
, pos
);
1168 if (!IS_ERR_OR_NULL(p
) && !*pos
)
1169 seq_puts(seqf
, "major minor #blocks name\n\n");
1173 static int show_partition(struct seq_file
*seqf
, void *v
)
1175 struct gendisk
*sgp
= v
;
1176 struct disk_part_iter piter
;
1177 struct hd_struct
*part
;
1178 char buf
[BDEVNAME_SIZE
];
1180 /* Don't show non-partitionable removeable devices or empty devices */
1181 if (!get_capacity(sgp
) || (!disk_max_parts(sgp
) &&
1182 (sgp
->flags
& GENHD_FL_REMOVABLE
)))
1184 if (sgp
->flags
& GENHD_FL_SUPPRESS_PARTITION_INFO
)
1187 /* show the full disk and all non-0 size partitions of it */
1188 disk_part_iter_init(&piter
, sgp
, DISK_PITER_INCL_PART0
);
1189 while ((part
= disk_part_iter_next(&piter
)))
1190 seq_printf(seqf
, "%4d %7d %10llu %s\n",
1191 MAJOR(part_devt(part
)), MINOR(part_devt(part
)),
1192 (unsigned long long)part_nr_sects_read(part
) >> 1,
1193 disk_name(sgp
, part
->partno
, buf
));
1194 disk_part_iter_exit(&piter
);
1199 static const struct seq_operations partitions_op
= {
1200 .start
= show_partition_start
,
1201 .next
= disk_seqf_next
,
1202 .stop
= disk_seqf_stop
,
1203 .show
= show_partition
1208 static struct kobject
*base_probe(dev_t devt
, int *partno
, void *data
)
1210 if (request_module("block-major-%d-%d", MAJOR(devt
), MINOR(devt
)) > 0)
1211 /* Make old-style 2.4 aliases work */
1212 request_module("block-major-%d", MAJOR(devt
));
1216 static int __init
genhd_device_init(void)
1220 block_class
.dev_kobj
= sysfs_dev_block_kobj
;
1221 error
= class_register(&block_class
);
1222 if (unlikely(error
))
1224 bdev_map
= kobj_map_init(base_probe
, &block_class_lock
);
1227 register_blkdev(BLOCK_EXT_MAJOR
, "blkext");
1229 /* create top-level block dir */
1230 if (!sysfs_deprecated
)
1231 block_depr
= kobject_create_and_add("block", NULL
);
1235 subsys_initcall(genhd_device_init
);
1237 static ssize_t
disk_range_show(struct device
*dev
,
1238 struct device_attribute
*attr
, char *buf
)
1240 struct gendisk
*disk
= dev_to_disk(dev
);
1242 return sprintf(buf
, "%d\n", disk
->minors
);
1245 static ssize_t
disk_ext_range_show(struct device
*dev
,
1246 struct device_attribute
*attr
, char *buf
)
1248 struct gendisk
*disk
= dev_to_disk(dev
);
1250 return sprintf(buf
, "%d\n", disk_max_parts(disk
));
1253 static ssize_t
disk_removable_show(struct device
*dev
,
1254 struct device_attribute
*attr
, char *buf
)
1256 struct gendisk
*disk
= dev_to_disk(dev
);
1258 return sprintf(buf
, "%d\n",
1259 (disk
->flags
& GENHD_FL_REMOVABLE
? 1 : 0));
1262 static ssize_t
disk_hidden_show(struct device
*dev
,
1263 struct device_attribute
*attr
, char *buf
)
1265 struct gendisk
*disk
= dev_to_disk(dev
);
1267 return sprintf(buf
, "%d\n",
1268 (disk
->flags
& GENHD_FL_HIDDEN
? 1 : 0));
1271 static ssize_t
disk_ro_show(struct device
*dev
,
1272 struct device_attribute
*attr
, char *buf
)
1274 struct gendisk
*disk
= dev_to_disk(dev
);
1276 return sprintf(buf
, "%d\n", get_disk_ro(disk
) ? 1 : 0);
1279 ssize_t
part_size_show(struct device
*dev
,
1280 struct device_attribute
*attr
, char *buf
)
1282 struct hd_struct
*p
= dev_to_part(dev
);
1284 return sprintf(buf
, "%llu\n",
1285 (unsigned long long)part_nr_sects_read(p
));
1288 ssize_t
part_stat_show(struct device
*dev
,
1289 struct device_attribute
*attr
, char *buf
)
1291 struct hd_struct
*p
= dev_to_part(dev
);
1292 struct request_queue
*q
= part_to_disk(p
)->queue
;
1293 struct disk_stats stat
;
1294 unsigned int inflight
;
1296 part_stat_read_all(p
, &stat
);
1298 inflight
= blk_mq_in_flight(q
, p
);
1300 inflight
= part_in_flight(p
);
1303 "%8lu %8lu %8llu %8u "
1304 "%8lu %8lu %8llu %8u "
1306 "%8lu %8lu %8llu %8u "
1309 stat
.ios
[STAT_READ
],
1310 stat
.merges
[STAT_READ
],
1311 (unsigned long long)stat
.sectors
[STAT_READ
],
1312 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
], NSEC_PER_MSEC
),
1313 stat
.ios
[STAT_WRITE
],
1314 stat
.merges
[STAT_WRITE
],
1315 (unsigned long long)stat
.sectors
[STAT_WRITE
],
1316 (unsigned int)div_u64(stat
.nsecs
[STAT_WRITE
], NSEC_PER_MSEC
),
1318 jiffies_to_msecs(stat
.io_ticks
),
1319 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
] +
1320 stat
.nsecs
[STAT_WRITE
] +
1321 stat
.nsecs
[STAT_DISCARD
] +
1322 stat
.nsecs
[STAT_FLUSH
],
1324 stat
.ios
[STAT_DISCARD
],
1325 stat
.merges
[STAT_DISCARD
],
1326 (unsigned long long)stat
.sectors
[STAT_DISCARD
],
1327 (unsigned int)div_u64(stat
.nsecs
[STAT_DISCARD
], NSEC_PER_MSEC
),
1328 stat
.ios
[STAT_FLUSH
],
1329 (unsigned int)div_u64(stat
.nsecs
[STAT_FLUSH
], NSEC_PER_MSEC
));
1332 ssize_t
part_inflight_show(struct device
*dev
, struct device_attribute
*attr
,
1335 struct hd_struct
*p
= dev_to_part(dev
);
1336 struct request_queue
*q
= part_to_disk(p
)->queue
;
1337 unsigned int inflight
[2];
1340 blk_mq_in_flight_rw(q
, p
, inflight
);
1342 part_in_flight_rw(p
, inflight
);
1344 return sprintf(buf
, "%8u %8u\n", inflight
[0], inflight
[1]);
1347 static ssize_t
disk_capability_show(struct device
*dev
,
1348 struct device_attribute
*attr
, char *buf
)
1350 struct gendisk
*disk
= dev_to_disk(dev
);
1352 return sprintf(buf
, "%x\n", disk
->flags
);
1355 static ssize_t
disk_alignment_offset_show(struct device
*dev
,
1356 struct device_attribute
*attr
,
1359 struct gendisk
*disk
= dev_to_disk(dev
);
1361 return sprintf(buf
, "%d\n", queue_alignment_offset(disk
->queue
));
1364 static ssize_t
disk_discard_alignment_show(struct device
*dev
,
1365 struct device_attribute
*attr
,
1368 struct gendisk
*disk
= dev_to_disk(dev
);
1370 return sprintf(buf
, "%d\n", queue_discard_alignment(disk
->queue
));
1373 static DEVICE_ATTR(range
, 0444, disk_range_show
, NULL
);
1374 static DEVICE_ATTR(ext_range
, 0444, disk_ext_range_show
, NULL
);
1375 static DEVICE_ATTR(removable
, 0444, disk_removable_show
, NULL
);
1376 static DEVICE_ATTR(hidden
, 0444, disk_hidden_show
, NULL
);
1377 static DEVICE_ATTR(ro
, 0444, disk_ro_show
, NULL
);
1378 static DEVICE_ATTR(size
, 0444, part_size_show
, NULL
);
1379 static DEVICE_ATTR(alignment_offset
, 0444, disk_alignment_offset_show
, NULL
);
1380 static DEVICE_ATTR(discard_alignment
, 0444, disk_discard_alignment_show
, NULL
);
1381 static DEVICE_ATTR(capability
, 0444, disk_capability_show
, NULL
);
1382 static DEVICE_ATTR(stat
, 0444, part_stat_show
, NULL
);
1383 static DEVICE_ATTR(inflight
, 0444, part_inflight_show
, NULL
);
1384 static DEVICE_ATTR(badblocks
, 0644, disk_badblocks_show
, disk_badblocks_store
);
1386 #ifdef CONFIG_FAIL_MAKE_REQUEST
1387 ssize_t
part_fail_show(struct device
*dev
,
1388 struct device_attribute
*attr
, char *buf
)
1390 struct hd_struct
*p
= dev_to_part(dev
);
1392 return sprintf(buf
, "%d\n", p
->make_it_fail
);
1395 ssize_t
part_fail_store(struct device
*dev
,
1396 struct device_attribute
*attr
,
1397 const char *buf
, size_t count
)
1399 struct hd_struct
*p
= dev_to_part(dev
);
1402 if (count
> 0 && sscanf(buf
, "%d", &i
) > 0)
1403 p
->make_it_fail
= (i
== 0) ? 0 : 1;
1408 static struct device_attribute dev_attr_fail
=
1409 __ATTR(make
-it
-fail
, 0644, part_fail_show
, part_fail_store
);
1410 #endif /* CONFIG_FAIL_MAKE_REQUEST */
1412 #ifdef CONFIG_FAIL_IO_TIMEOUT
1413 static struct device_attribute dev_attr_fail_timeout
=
1414 __ATTR(io
-timeout
-fail
, 0644, part_timeout_show
, part_timeout_store
);
1417 static struct attribute
*disk_attrs
[] = {
1418 &dev_attr_range
.attr
,
1419 &dev_attr_ext_range
.attr
,
1420 &dev_attr_removable
.attr
,
1421 &dev_attr_hidden
.attr
,
1423 &dev_attr_size
.attr
,
1424 &dev_attr_alignment_offset
.attr
,
1425 &dev_attr_discard_alignment
.attr
,
1426 &dev_attr_capability
.attr
,
1427 &dev_attr_stat
.attr
,
1428 &dev_attr_inflight
.attr
,
1429 &dev_attr_badblocks
.attr
,
1430 #ifdef CONFIG_FAIL_MAKE_REQUEST
1431 &dev_attr_fail
.attr
,
1433 #ifdef CONFIG_FAIL_IO_TIMEOUT
1434 &dev_attr_fail_timeout
.attr
,
1439 static umode_t
disk_visible(struct kobject
*kobj
, struct attribute
*a
, int n
)
1441 struct device
*dev
= container_of(kobj
, typeof(*dev
), kobj
);
1442 struct gendisk
*disk
= dev_to_disk(dev
);
1444 if (a
== &dev_attr_badblocks
.attr
&& !disk
->bb
)
1449 static struct attribute_group disk_attr_group
= {
1450 .attrs
= disk_attrs
,
1451 .is_visible
= disk_visible
,
1454 static const struct attribute_group
*disk_attr_groups
[] = {
1460 * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
1461 * @disk: disk to replace part_tbl for
1462 * @new_ptbl: new part_tbl to install
1464 * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The
1465 * original ptbl is freed using RCU callback.
1468 * Matching bd_mutex locked or the caller is the only user of @disk.
1470 static void disk_replace_part_tbl(struct gendisk
*disk
,
1471 struct disk_part_tbl
*new_ptbl
)
1473 struct disk_part_tbl
*old_ptbl
=
1474 rcu_dereference_protected(disk
->part_tbl
, 1);
1476 rcu_assign_pointer(disk
->part_tbl
, new_ptbl
);
1479 rcu_assign_pointer(old_ptbl
->last_lookup
, NULL
);
1480 kfree_rcu(old_ptbl
, rcu_head
);
1485 * disk_expand_part_tbl - expand disk->part_tbl
1486 * @disk: disk to expand part_tbl for
1487 * @partno: expand such that this partno can fit in
1489 * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl
1490 * uses RCU to allow unlocked dereferencing for stats and other stuff.
1493 * Matching bd_mutex locked or the caller is the only user of @disk.
1497 * 0 on success, -errno on failure.
1499 int disk_expand_part_tbl(struct gendisk
*disk
, int partno
)
1501 struct disk_part_tbl
*old_ptbl
=
1502 rcu_dereference_protected(disk
->part_tbl
, 1);
1503 struct disk_part_tbl
*new_ptbl
;
1504 int len
= old_ptbl
? old_ptbl
->len
: 0;
1508 * check for int overflow, since we can get here from blkpg_ioctl()
1509 * with a user passed 'partno'.
1511 target
= partno
+ 1;
1515 /* disk_max_parts() is zero during initialization, ignore if so */
1516 if (disk_max_parts(disk
) && target
> disk_max_parts(disk
))
1522 new_ptbl
= kzalloc_node(struct_size(new_ptbl
, part
, target
), GFP_KERNEL
,
1527 new_ptbl
->len
= target
;
1529 for (i
= 0; i
< len
; i
++)
1530 rcu_assign_pointer(new_ptbl
->part
[i
], old_ptbl
->part
[i
]);
1532 disk_replace_part_tbl(disk
, new_ptbl
);
1537 * disk_release - releases all allocated resources of the gendisk
1538 * @dev: the device representing this disk
1540 * This function releases all allocated resources of the gendisk.
1542 * The struct gendisk refcount is incremented with get_gendisk() or
1543 * get_disk_and_module(), and its refcount is decremented with
1544 * put_disk_and_module() or put_disk(). Once the refcount reaches 0 this
1545 * function is called.
1547 * Drivers which used __device_add_disk() have a gendisk with a request_queue
1548 * assigned. Since the request_queue sits on top of the gendisk for these
1549 * drivers we also call blk_put_queue() for them, and we expect the
1550 * request_queue refcount to reach 0 at this point, and so the request_queue
1551 * will also be freed prior to the disk.
1553 * Context: can sleep
1555 static void disk_release(struct device
*dev
)
1557 struct gendisk
*disk
= dev_to_disk(dev
);
1561 blk_free_devt(dev
->devt
);
1562 disk_release_events(disk
);
1563 kfree(disk
->random
);
1564 disk_replace_part_tbl(disk
, NULL
);
1565 hd_free_part(&disk
->part0
);
1567 blk_put_queue(disk
->queue
);
1570 struct class block_class
= {
1574 static char *block_devnode(struct device
*dev
, umode_t
*mode
,
1575 kuid_t
*uid
, kgid_t
*gid
)
1577 struct gendisk
*disk
= dev_to_disk(dev
);
1579 if (disk
->fops
->devnode
)
1580 return disk
->fops
->devnode(disk
, mode
);
1584 const struct device_type disk_type
= {
1586 .groups
= disk_attr_groups
,
1587 .release
= disk_release
,
1588 .devnode
= block_devnode
,
1591 #ifdef CONFIG_PROC_FS
1593 * aggregate disk stat collector. Uses the same stats that the sysfs
1594 * entries do, above, but makes them available through one seq_file.
1596 * The output looks suspiciously like /proc/partitions with a bunch of
1599 static int diskstats_show(struct seq_file
*seqf
, void *v
)
1601 struct gendisk
*gp
= v
;
1602 struct disk_part_iter piter
;
1603 struct hd_struct
*hd
;
1604 char buf
[BDEVNAME_SIZE
];
1605 unsigned int inflight
;
1606 struct disk_stats stat
;
1609 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1610 seq_puts(seqf, "major minor name"
1611 " rio rmerge rsect ruse wio wmerge "
1612 "wsect wuse running use aveq"
1616 disk_part_iter_init(&piter
, gp
, DISK_PITER_INCL_EMPTY_PART0
);
1617 while ((hd
= disk_part_iter_next(&piter
))) {
1618 part_stat_read_all(hd
, &stat
);
1619 if (queue_is_mq(gp
->queue
))
1620 inflight
= blk_mq_in_flight(gp
->queue
, hd
);
1622 inflight
= part_in_flight(hd
);
1624 seq_printf(seqf
, "%4d %7d %s "
1631 MAJOR(part_devt(hd
)), MINOR(part_devt(hd
)),
1632 disk_name(gp
, hd
->partno
, buf
),
1633 stat
.ios
[STAT_READ
],
1634 stat
.merges
[STAT_READ
],
1635 stat
.sectors
[STAT_READ
],
1636 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
],
1638 stat
.ios
[STAT_WRITE
],
1639 stat
.merges
[STAT_WRITE
],
1640 stat
.sectors
[STAT_WRITE
],
1641 (unsigned int)div_u64(stat
.nsecs
[STAT_WRITE
],
1644 jiffies_to_msecs(stat
.io_ticks
),
1645 (unsigned int)div_u64(stat
.nsecs
[STAT_READ
] +
1646 stat
.nsecs
[STAT_WRITE
] +
1647 stat
.nsecs
[STAT_DISCARD
] +
1648 stat
.nsecs
[STAT_FLUSH
],
1650 stat
.ios
[STAT_DISCARD
],
1651 stat
.merges
[STAT_DISCARD
],
1652 stat
.sectors
[STAT_DISCARD
],
1653 (unsigned int)div_u64(stat
.nsecs
[STAT_DISCARD
],
1655 stat
.ios
[STAT_FLUSH
],
1656 (unsigned int)div_u64(stat
.nsecs
[STAT_FLUSH
],
1660 disk_part_iter_exit(&piter
);
1665 static const struct seq_operations diskstats_op
= {
1666 .start
= disk_seqf_start
,
1667 .next
= disk_seqf_next
,
1668 .stop
= disk_seqf_stop
,
1669 .show
= diskstats_show
1672 static int __init
proc_genhd_init(void)
1674 proc_create_seq("diskstats", 0, NULL
, &diskstats_op
);
1675 proc_create_seq("partitions", 0, NULL
, &partitions_op
);
1678 module_init(proc_genhd_init
);
1679 #endif /* CONFIG_PROC_FS */
1681 dev_t
blk_lookup_devt(const char *name
, int partno
)
1683 dev_t devt
= MKDEV(0, 0);
1684 struct class_dev_iter iter
;
1687 class_dev_iter_init(&iter
, &block_class
, NULL
, &disk_type
);
1688 while ((dev
= class_dev_iter_next(&iter
))) {
1689 struct gendisk
*disk
= dev_to_disk(dev
);
1690 struct hd_struct
*part
;
1692 if (strcmp(dev_name(dev
), name
))
1695 if (partno
< disk
->minors
) {
1696 /* We need to return the right devno, even
1697 * if the partition doesn't exist yet.
1699 devt
= MKDEV(MAJOR(dev
->devt
),
1700 MINOR(dev
->devt
) + partno
);
1703 part
= disk_get_part(disk
, partno
);
1705 devt
= part_devt(part
);
1706 disk_put_part(part
);
1709 disk_put_part(part
);
1711 class_dev_iter_exit(&iter
);
1715 struct gendisk
*__alloc_disk_node(int minors
, int node_id
)
1717 struct gendisk
*disk
;
1718 struct disk_part_tbl
*ptbl
;
1720 if (minors
> DISK_MAX_PARTS
) {
1722 "block: can't allocate more than %d partitions\n",
1724 minors
= DISK_MAX_PARTS
;
1727 disk
= kzalloc_node(sizeof(struct gendisk
), GFP_KERNEL
, node_id
);
1731 disk
->part0
.dkstats
= alloc_percpu(struct disk_stats
);
1732 if (!disk
->part0
.dkstats
)
1735 init_rwsem(&disk
->lookup_sem
);
1736 disk
->node_id
= node_id
;
1737 if (disk_expand_part_tbl(disk
, 0)) {
1738 free_percpu(disk
->part0
.dkstats
);
1742 ptbl
= rcu_dereference_protected(disk
->part_tbl
, 1);
1743 rcu_assign_pointer(ptbl
->part
[0], &disk
->part0
);
1746 * set_capacity() and get_capacity() currently don't use
1747 * seqcounter to read/update the part0->nr_sects. Still init
1748 * the counter as we can read the sectors in IO submission
1749 * patch using seqence counters.
1751 * TODO: Ideally set_capacity() and get_capacity() should be
1752 * converted to make use of bd_mutex and sequence counters.
1754 hd_sects_seq_init(&disk
->part0
);
1755 if (hd_ref_init(&disk
->part0
))
1756 goto out_free_part0
;
1758 disk
->minors
= minors
;
1759 rand_initialize_disk(disk
);
1760 disk_to_dev(disk
)->class = &block_class
;
1761 disk_to_dev(disk
)->type
= &disk_type
;
1762 device_initialize(disk_to_dev(disk
));
1766 hd_free_part(&disk
->part0
);
1771 EXPORT_SYMBOL(__alloc_disk_node
);
1774 * get_disk_and_module - increments the gendisk and gendisk fops module refcount
1775 * @disk: the struct gendisk to increment the refcount for
1777 * This increments the refcount for the struct gendisk, and the gendisk's
1778 * fops module owner.
1780 * Context: Any context.
1782 struct kobject
*get_disk_and_module(struct gendisk
*disk
)
1784 struct module
*owner
;
1785 struct kobject
*kobj
;
1789 owner
= disk
->fops
->owner
;
1790 if (owner
&& !try_module_get(owner
))
1792 kobj
= kobject_get_unless_zero(&disk_to_dev(disk
)->kobj
);
1800 EXPORT_SYMBOL(get_disk_and_module
);
1803 * put_disk - decrements the gendisk refcount
1804 * @disk: the struct gendisk to decrement the refcount for
1806 * This decrements the refcount for the struct gendisk. When this reaches 0
1807 * we'll have disk_release() called.
1809 * Context: Any context, but the last reference must not be dropped from
1812 void put_disk(struct gendisk
*disk
)
1815 kobject_put(&disk_to_dev(disk
)->kobj
);
1817 EXPORT_SYMBOL(put_disk
);
1820 * put_disk_and_module - decrements the module and gendisk refcount
1821 * @disk: the struct gendisk to decrement the refcount for
1823 * This is a counterpart of get_disk_and_module() and thus also of
1826 * Context: Any context, but the last reference must not be dropped from
1829 void put_disk_and_module(struct gendisk
*disk
)
1832 struct module
*owner
= disk
->fops
->owner
;
1838 EXPORT_SYMBOL(put_disk_and_module
);
1840 static void set_disk_ro_uevent(struct gendisk
*gd
, int ro
)
1842 char event
[] = "DISK_RO=1";
1843 char *envp
[] = { event
, NULL
};
1847 kobject_uevent_env(&disk_to_dev(gd
)->kobj
, KOBJ_CHANGE
, envp
);
1850 void set_device_ro(struct block_device
*bdev
, int flag
)
1852 bdev
->bd_part
->policy
= flag
;
1855 EXPORT_SYMBOL(set_device_ro
);
1857 void set_disk_ro(struct gendisk
*disk
, int flag
)
1859 struct disk_part_iter piter
;
1860 struct hd_struct
*part
;
1862 if (disk
->part0
.policy
!= flag
) {
1863 set_disk_ro_uevent(disk
, flag
);
1864 disk
->part0
.policy
= flag
;
1867 disk_part_iter_init(&piter
, disk
, DISK_PITER_INCL_EMPTY
);
1868 while ((part
= disk_part_iter_next(&piter
)))
1869 part
->policy
= flag
;
1870 disk_part_iter_exit(&piter
);
1873 EXPORT_SYMBOL(set_disk_ro
);
1875 int bdev_read_only(struct block_device
*bdev
)
1879 return bdev
->bd_part
->policy
;
1882 EXPORT_SYMBOL(bdev_read_only
);
1885 * Disk events - monitor disk events like media change and eject request.
1887 struct disk_events
{
1888 struct list_head node
; /* all disk_event's */
1889 struct gendisk
*disk
; /* the associated disk */
1892 struct mutex block_mutex
; /* protects blocking */
1893 int block
; /* event blocking depth */
1894 unsigned int pending
; /* events already sent out */
1895 unsigned int clearing
; /* events being cleared */
1897 long poll_msecs
; /* interval, -1 for default */
1898 struct delayed_work dwork
;
1901 static const char *disk_events_strs
[] = {
1902 [ilog2(DISK_EVENT_MEDIA_CHANGE
)] = "media_change",
1903 [ilog2(DISK_EVENT_EJECT_REQUEST
)] = "eject_request",
1906 static char *disk_uevents
[] = {
1907 [ilog2(DISK_EVENT_MEDIA_CHANGE
)] = "DISK_MEDIA_CHANGE=1",
1908 [ilog2(DISK_EVENT_EJECT_REQUEST
)] = "DISK_EJECT_REQUEST=1",
1911 /* list of all disk_events */
1912 static DEFINE_MUTEX(disk_events_mutex
);
1913 static LIST_HEAD(disk_events
);
1915 /* disable in-kernel polling by default */
1916 static unsigned long disk_events_dfl_poll_msecs
;
1918 static unsigned long disk_events_poll_jiffies(struct gendisk
*disk
)
1920 struct disk_events
*ev
= disk
->ev
;
1921 long intv_msecs
= 0;
1924 * If device-specific poll interval is set, always use it. If
1925 * the default is being used, poll if the POLL flag is set.
1927 if (ev
->poll_msecs
>= 0)
1928 intv_msecs
= ev
->poll_msecs
;
1929 else if (disk
->event_flags
& DISK_EVENT_FLAG_POLL
)
1930 intv_msecs
= disk_events_dfl_poll_msecs
;
1932 return msecs_to_jiffies(intv_msecs
);
1936 * disk_block_events - block and flush disk event checking
1937 * @disk: disk to block events for
1939 * On return from this function, it is guaranteed that event checking
1940 * isn't in progress and won't happen until unblocked by
1941 * disk_unblock_events(). Events blocking is counted and the actual
1942 * unblocking happens after the matching number of unblocks are done.
1944 * Note that this intentionally does not block event checking from
1945 * disk_clear_events().
1950 void disk_block_events(struct gendisk
*disk
)
1952 struct disk_events
*ev
= disk
->ev
;
1953 unsigned long flags
;
1960 * Outer mutex ensures that the first blocker completes canceling
1961 * the event work before further blockers are allowed to finish.
1963 mutex_lock(&ev
->block_mutex
);
1965 spin_lock_irqsave(&ev
->lock
, flags
);
1966 cancel
= !ev
->block
++;
1967 spin_unlock_irqrestore(&ev
->lock
, flags
);
1970 cancel_delayed_work_sync(&disk
->ev
->dwork
);
1972 mutex_unlock(&ev
->block_mutex
);
1975 static void __disk_unblock_events(struct gendisk
*disk
, bool check_now
)
1977 struct disk_events
*ev
= disk
->ev
;
1979 unsigned long flags
;
1981 spin_lock_irqsave(&ev
->lock
, flags
);
1983 if (WARN_ON_ONCE(ev
->block
<= 0))
1989 intv
= disk_events_poll_jiffies(disk
);
1991 queue_delayed_work(system_freezable_power_efficient_wq
,
1994 queue_delayed_work(system_freezable_power_efficient_wq
,
1997 spin_unlock_irqrestore(&ev
->lock
, flags
);
2001 * disk_unblock_events - unblock disk event checking
2002 * @disk: disk to unblock events for
2004 * Undo disk_block_events(). When the block count reaches zero, it
2005 * starts events polling if configured.
2008 * Don't care. Safe to call from irq context.
2010 void disk_unblock_events(struct gendisk
*disk
)
2013 __disk_unblock_events(disk
, false);
2017 * disk_flush_events - schedule immediate event checking and flushing
2018 * @disk: disk to check and flush events for
2019 * @mask: events to flush
2021 * Schedule immediate event checking on @disk if not blocked. Events in
2022 * @mask are scheduled to be cleared from the driver. Note that this
2023 * doesn't clear the events from @disk->ev.
2026 * If @mask is non-zero must be called with bdev->bd_mutex held.
2028 void disk_flush_events(struct gendisk
*disk
, unsigned int mask
)
2030 struct disk_events
*ev
= disk
->ev
;
2035 spin_lock_irq(&ev
->lock
);
2036 ev
->clearing
|= mask
;
2038 mod_delayed_work(system_freezable_power_efficient_wq
,
2040 spin_unlock_irq(&ev
->lock
);
2044 * disk_clear_events - synchronously check, clear and return pending events
2045 * @disk: disk to fetch and clear events from
2046 * @mask: mask of events to be fetched and cleared
2048 * Disk events are synchronously checked and pending events in @mask
2049 * are cleared and returned. This ignores the block count.
2054 static unsigned int disk_clear_events(struct gendisk
*disk
, unsigned int mask
)
2056 struct disk_events
*ev
= disk
->ev
;
2057 unsigned int pending
;
2058 unsigned int clearing
= mask
;
2063 disk_block_events(disk
);
2066 * store the union of mask and ev->clearing on the stack so that the
2067 * race with disk_flush_events does not cause ambiguity (ev->clearing
2068 * can still be modified even if events are blocked).
2070 spin_lock_irq(&ev
->lock
);
2071 clearing
|= ev
->clearing
;
2073 spin_unlock_irq(&ev
->lock
);
2075 disk_check_events(ev
, &clearing
);
2077 * if ev->clearing is not 0, the disk_flush_events got called in the
2078 * middle of this function, so we want to run the workfn without delay.
2080 __disk_unblock_events(disk
, ev
->clearing
? true : false);
2082 /* then, fetch and clear pending events */
2083 spin_lock_irq(&ev
->lock
);
2084 pending
= ev
->pending
& mask
;
2085 ev
->pending
&= ~mask
;
2086 spin_unlock_irq(&ev
->lock
);
2087 WARN_ON_ONCE(clearing
& mask
);
2093 * bdev_check_media_change - check if a removable media has been changed
2094 * @bdev: block device to check
2096 * Check whether a removable media has been changed, and attempt to free all
2097 * dentries and inodes and invalidates all block device page cache entries in
2100 * Returns %true if the block device changed, or %false if not.
2102 bool bdev_check_media_change(struct block_device
*bdev
)
2104 unsigned int events
;
2106 events
= disk_clear_events(bdev
->bd_disk
, DISK_EVENT_MEDIA_CHANGE
|
2107 DISK_EVENT_EJECT_REQUEST
);
2108 if (!(events
& DISK_EVENT_MEDIA_CHANGE
))
2111 if (__invalidate_device(bdev
, true))
2112 pr_warn("VFS: busy inodes on changed media %s\n",
2113 bdev
->bd_disk
->disk_name
);
2114 set_bit(GD_NEED_PART_SCAN
, &bdev
->bd_disk
->state
);
2117 EXPORT_SYMBOL(bdev_check_media_change
);
2120 * Separate this part out so that a different pointer for clearing_ptr can be
2121 * passed in for disk_clear_events.
2123 static void disk_events_workfn(struct work_struct
*work
)
2125 struct delayed_work
*dwork
= to_delayed_work(work
);
2126 struct disk_events
*ev
= container_of(dwork
, struct disk_events
, dwork
);
2128 disk_check_events(ev
, &ev
->clearing
);
2131 static void disk_check_events(struct disk_events
*ev
,
2132 unsigned int *clearing_ptr
)
2134 struct gendisk
*disk
= ev
->disk
;
2135 char *envp
[ARRAY_SIZE(disk_uevents
) + 1] = { };
2136 unsigned int clearing
= *clearing_ptr
;
2137 unsigned int events
;
2139 int nr_events
= 0, i
;
2142 events
= disk
->fops
->check_events(disk
, clearing
);
2144 /* accumulate pending events and schedule next poll if necessary */
2145 spin_lock_irq(&ev
->lock
);
2147 events
&= ~ev
->pending
;
2148 ev
->pending
|= events
;
2149 *clearing_ptr
&= ~clearing
;
2151 intv
= disk_events_poll_jiffies(disk
);
2152 if (!ev
->block
&& intv
)
2153 queue_delayed_work(system_freezable_power_efficient_wq
,
2156 spin_unlock_irq(&ev
->lock
);
2159 * Tell userland about new events. Only the events listed in
2160 * @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT
2161 * is set. Otherwise, events are processed internally but never
2162 * get reported to userland.
2164 for (i
= 0; i
< ARRAY_SIZE(disk_uevents
); i
++)
2165 if ((events
& disk
->events
& (1 << i
)) &&
2166 (disk
->event_flags
& DISK_EVENT_FLAG_UEVENT
))
2167 envp
[nr_events
++] = disk_uevents
[i
];
2170 kobject_uevent_env(&disk_to_dev(disk
)->kobj
, KOBJ_CHANGE
, envp
);
2174 * A disk events enabled device has the following sysfs nodes under
2175 * its /sys/block/X/ directory.
2177 * events : list of all supported events
2178 * events_async : list of events which can be detected w/o polling
2179 * (always empty, only for backwards compatibility)
2180 * events_poll_msecs : polling interval, 0: disable, -1: system default
2182 static ssize_t
__disk_events_show(unsigned int events
, char *buf
)
2184 const char *delim
= "";
2188 for (i
= 0; i
< ARRAY_SIZE(disk_events_strs
); i
++)
2189 if (events
& (1 << i
)) {
2190 pos
+= sprintf(buf
+ pos
, "%s%s",
2191 delim
, disk_events_strs
[i
]);
2195 pos
+= sprintf(buf
+ pos
, "\n");
2199 static ssize_t
disk_events_show(struct device
*dev
,
2200 struct device_attribute
*attr
, char *buf
)
2202 struct gendisk
*disk
= dev_to_disk(dev
);
2204 if (!(disk
->event_flags
& DISK_EVENT_FLAG_UEVENT
))
2207 return __disk_events_show(disk
->events
, buf
);
2210 static ssize_t
disk_events_async_show(struct device
*dev
,
2211 struct device_attribute
*attr
, char *buf
)
2216 static ssize_t
disk_events_poll_msecs_show(struct device
*dev
,
2217 struct device_attribute
*attr
,
2220 struct gendisk
*disk
= dev_to_disk(dev
);
2223 return sprintf(buf
, "-1\n");
2225 return sprintf(buf
, "%ld\n", disk
->ev
->poll_msecs
);
2228 static ssize_t
disk_events_poll_msecs_store(struct device
*dev
,
2229 struct device_attribute
*attr
,
2230 const char *buf
, size_t count
)
2232 struct gendisk
*disk
= dev_to_disk(dev
);
2235 if (!count
|| !sscanf(buf
, "%ld", &intv
))
2238 if (intv
< 0 && intv
!= -1)
2244 disk_block_events(disk
);
2245 disk
->ev
->poll_msecs
= intv
;
2246 __disk_unblock_events(disk
, true);
2251 static const DEVICE_ATTR(events
, 0444, disk_events_show
, NULL
);
2252 static const DEVICE_ATTR(events_async
, 0444, disk_events_async_show
, NULL
);
2253 static const DEVICE_ATTR(events_poll_msecs
, 0644,
2254 disk_events_poll_msecs_show
,
2255 disk_events_poll_msecs_store
);
2257 static const struct attribute
*disk_events_attrs
[] = {
2258 &dev_attr_events
.attr
,
2259 &dev_attr_events_async
.attr
,
2260 &dev_attr_events_poll_msecs
.attr
,
2265 * The default polling interval can be specified by the kernel
2266 * parameter block.events_dfl_poll_msecs which defaults to 0
2267 * (disable). This can also be modified runtime by writing to
2268 * /sys/module/block/parameters/events_dfl_poll_msecs.
2270 static int disk_events_set_dfl_poll_msecs(const char *val
,
2271 const struct kernel_param
*kp
)
2273 struct disk_events
*ev
;
2276 ret
= param_set_ulong(val
, kp
);
2280 mutex_lock(&disk_events_mutex
);
2282 list_for_each_entry(ev
, &disk_events
, node
)
2283 disk_flush_events(ev
->disk
, 0);
2285 mutex_unlock(&disk_events_mutex
);
2290 static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops
= {
2291 .set
= disk_events_set_dfl_poll_msecs
,
2292 .get
= param_get_ulong
,
2295 #undef MODULE_PARAM_PREFIX
2296 #define MODULE_PARAM_PREFIX "block."
2298 module_param_cb(events_dfl_poll_msecs
, &disk_events_dfl_poll_msecs_param_ops
,
2299 &disk_events_dfl_poll_msecs
, 0644);
2302 * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
2304 static void disk_alloc_events(struct gendisk
*disk
)
2306 struct disk_events
*ev
;
2308 if (!disk
->fops
->check_events
|| !disk
->events
)
2311 ev
= kzalloc(sizeof(*ev
), GFP_KERNEL
);
2313 pr_warn("%s: failed to initialize events\n", disk
->disk_name
);
2317 INIT_LIST_HEAD(&ev
->node
);
2319 spin_lock_init(&ev
->lock
);
2320 mutex_init(&ev
->block_mutex
);
2322 ev
->poll_msecs
= -1;
2323 INIT_DELAYED_WORK(&ev
->dwork
, disk_events_workfn
);
2328 static void disk_add_events(struct gendisk
*disk
)
2330 /* FIXME: error handling */
2331 if (sysfs_create_files(&disk_to_dev(disk
)->kobj
, disk_events_attrs
) < 0)
2332 pr_warn("%s: failed to create sysfs files for events\n",
2338 mutex_lock(&disk_events_mutex
);
2339 list_add_tail(&disk
->ev
->node
, &disk_events
);
2340 mutex_unlock(&disk_events_mutex
);
2343 * Block count is initialized to 1 and the following initial
2344 * unblock kicks it into action.
2346 __disk_unblock_events(disk
, true);
2349 static void disk_del_events(struct gendisk
*disk
)
2352 disk_block_events(disk
);
2354 mutex_lock(&disk_events_mutex
);
2355 list_del_init(&disk
->ev
->node
);
2356 mutex_unlock(&disk_events_mutex
);
2359 sysfs_remove_files(&disk_to_dev(disk
)->kobj
, disk_events_attrs
);
2362 static void disk_release_events(struct gendisk
*disk
)
2364 /* the block count should be 1 from disk_del_events() */
2365 WARN_ON_ONCE(disk
->ev
&& disk
->ev
->block
!= 1);