5 #include <linux/module.h>
7 #include <linux/genhd.h>
8 #include <linux/kdev_t.h>
9 #include <linux/kernel.h>
10 #include <linux/blkdev.h>
11 #include <linux/init.h>
12 #include <linux/spinlock.h>
13 #include <linux/proc_fs.h>
14 #include <linux/seq_file.h>
15 #include <linux/slab.h>
16 #include <linux/kmod.h>
17 #include <linux/kobj_map.h>
18 #include <linux/mutex.h>
19 #include <linux/idr.h>
20 #include <linux/log2.h>
21 #include <linux/pm_runtime.h>
23 #ifdef CONFIG_BLOCK_SUPPORT_STLOG
24 #include <linux/stlog.h>
26 #define ST_LOG(fmt,...)
31 static DEFINE_MUTEX(block_class_lock
);
32 struct kobject
*block_depr
;
34 /* for extended dynamic devt allocation, currently only one major is used */
35 #define NR_EXT_DEVT (1 << MINORBITS)
37 /* For extended devt allocation. ext_devt_lock prevents look up
38 * results from going away underneath its user.
40 static DEFINE_SPINLOCK(ext_devt_lock
);
41 static DEFINE_IDR(ext_devt_idr
);
43 static struct device_type disk_type
;
45 static void disk_check_events(struct disk_events
*ev
,
46 unsigned int *clearing_ptr
);
47 static void disk_alloc_events(struct gendisk
*disk
);
48 static void disk_add_events(struct gendisk
*disk
);
49 static void disk_del_events(struct gendisk
*disk
);
50 static void disk_release_events(struct gendisk
*disk
);
53 * disk_get_part - get partition
54 * @disk: disk to look partition from
55 * @partno: partition number
57 * Look for partition @partno from @disk. If found, increment
58 * reference count and return it.
64 * Pointer to the found partition on success, NULL if not found.
66 struct hd_struct
*disk_get_part(struct gendisk
*disk
, int partno
)
68 struct hd_struct
*part
= NULL
;
69 struct disk_part_tbl
*ptbl
;
71 if (unlikely(partno
< 0))
76 ptbl
= rcu_dereference(disk
->part_tbl
);
77 if (likely(partno
< ptbl
->len
)) {
78 part
= rcu_dereference(ptbl
->part
[partno
]);
80 get_device(part_to_dev(part
));
87 EXPORT_SYMBOL_GPL(disk_get_part
);
90 * disk_part_iter_init - initialize partition iterator
91 * @piter: iterator to initialize
92 * @disk: disk to iterate over
93 * @flags: DISK_PITER_* flags
95 * Initialize @piter so that it iterates over partitions of @disk.
100 void disk_part_iter_init(struct disk_part_iter
*piter
, struct gendisk
*disk
,
103 struct disk_part_tbl
*ptbl
;
106 ptbl
= rcu_dereference(disk
->part_tbl
);
111 if (flags
& DISK_PITER_REVERSE
)
112 piter
->idx
= ptbl
->len
- 1;
113 else if (flags
& (DISK_PITER_INCL_PART0
| DISK_PITER_INCL_EMPTY_PART0
))
118 piter
->flags
= flags
;
122 EXPORT_SYMBOL_GPL(disk_part_iter_init
);
125 * disk_part_iter_next - proceed iterator to the next partition and return it
126 * @piter: iterator of interest
128 * Proceed @piter to the next partition and return it.
133 struct hd_struct
*disk_part_iter_next(struct disk_part_iter
*piter
)
135 struct disk_part_tbl
*ptbl
;
138 /* put the last partition */
139 disk_put_part(piter
->part
);
144 ptbl
= rcu_dereference(piter
->disk
->part_tbl
);
146 /* determine iteration parameters */
147 if (piter
->flags
& DISK_PITER_REVERSE
) {
149 if (piter
->flags
& (DISK_PITER_INCL_PART0
|
150 DISK_PITER_INCL_EMPTY_PART0
))
159 /* iterate to the next partition */
160 for (; piter
->idx
!= end
; piter
->idx
+= inc
) {
161 struct hd_struct
*part
;
163 part
= rcu_dereference(ptbl
->part
[piter
->idx
]);
166 if (!part_nr_sects_read(part
) &&
167 !(piter
->flags
& DISK_PITER_INCL_EMPTY
) &&
168 !(piter
->flags
& DISK_PITER_INCL_EMPTY_PART0
&&
172 get_device(part_to_dev(part
));
182 EXPORT_SYMBOL_GPL(disk_part_iter_next
);
185 * disk_part_iter_exit - finish up partition iteration
186 * @piter: iter of interest
188 * Called when iteration is over. Cleans up @piter.
193 void disk_part_iter_exit(struct disk_part_iter
*piter
)
195 disk_put_part(piter
->part
);
198 EXPORT_SYMBOL_GPL(disk_part_iter_exit
);
200 static inline int sector_in_part(struct hd_struct
*part
, sector_t sector
)
202 return part
->start_sect
<= sector
&&
203 sector
< part
->start_sect
+ part_nr_sects_read(part
);
207 * disk_map_sector_rcu - map sector to partition
208 * @disk: gendisk of interest
209 * @sector: sector to map
211 * Find out which partition @sector maps to on @disk. This is
212 * primarily used for stats accounting.
215 * RCU read locked. The returned partition pointer is valid only
216 * while preemption is disabled.
219 * Found partition on success, part0 is returned if no partition matches
221 struct hd_struct
*disk_map_sector_rcu(struct gendisk
*disk
, sector_t sector
)
223 struct disk_part_tbl
*ptbl
;
224 struct hd_struct
*part
;
227 ptbl
= rcu_dereference(disk
->part_tbl
);
229 part
= rcu_dereference(ptbl
->last_lookup
);
230 if (part
&& sector_in_part(part
, sector
))
233 for (i
= 1; i
< ptbl
->len
; i
++) {
234 part
= rcu_dereference(ptbl
->part
[i
]);
236 if (part
&& sector_in_part(part
, sector
)) {
237 rcu_assign_pointer(ptbl
->last_lookup
, part
);
243 EXPORT_SYMBOL_GPL(disk_map_sector_rcu
);
246 * Can be deleted altogether. Later.
249 static struct blk_major_name
{
250 struct blk_major_name
*next
;
253 } *major_names
[BLKDEV_MAJOR_HASH_SIZE
];
255 /* index in the above - for now: assume no multimajor ranges */
256 static inline int major_to_index(unsigned major
)
258 return major
% BLKDEV_MAJOR_HASH_SIZE
;
261 #ifdef CONFIG_PROC_FS
262 void blkdev_show(struct seq_file
*seqf
, off_t offset
)
264 struct blk_major_name
*dp
;
266 if (offset
< BLKDEV_MAJOR_HASH_SIZE
) {
267 mutex_lock(&block_class_lock
);
268 for (dp
= major_names
[offset
]; dp
; dp
= dp
->next
)
269 seq_printf(seqf
, "%3d %s\n", dp
->major
, dp
->name
);
270 mutex_unlock(&block_class_lock
);
273 #endif /* CONFIG_PROC_FS */
276 * register_blkdev - register a new block device
278 * @major: the requested major device number [1..255]. If @major=0, try to
279 * allocate any unused major number.
280 * @name: the name of the new block device as a zero terminated string
282 * The @name must be unique within the system.
284 * The return value depends on the @major input parameter.
285 * - if a major device number was requested in range [1..255] then the
286 * function returns zero on success, or a negative error code
287 * - if any unused major number was requested with @major=0 parameter
288 * then the return value is the allocated major number in range
289 * [1..255] or a negative error code otherwise
291 int register_blkdev(unsigned int major
, const char *name
)
293 struct blk_major_name
**n
, *p
;
296 mutex_lock(&block_class_lock
);
300 for (index
= ARRAY_SIZE(major_names
)-1; index
> 0; index
--) {
301 if (major_names
[index
] == NULL
)
306 printk("register_blkdev: failed to get major for %s\n",
315 p
= kmalloc(sizeof(struct blk_major_name
), GFP_KERNEL
);
322 strlcpy(p
->name
, name
, sizeof(p
->name
));
324 index
= major_to_index(major
);
326 for (n
= &major_names
[index
]; *n
; n
= &(*n
)->next
) {
327 if ((*n
)->major
== major
)
336 printk("register_blkdev: cannot get major %d for %s\n",
341 mutex_unlock(&block_class_lock
);
345 EXPORT_SYMBOL(register_blkdev
);
347 void unregister_blkdev(unsigned int major
, const char *name
)
349 struct blk_major_name
**n
;
350 struct blk_major_name
*p
= NULL
;
351 int index
= major_to_index(major
);
353 mutex_lock(&block_class_lock
);
354 for (n
= &major_names
[index
]; *n
; n
= &(*n
)->next
)
355 if ((*n
)->major
== major
)
357 if (!*n
|| strcmp((*n
)->name
, name
)) {
363 mutex_unlock(&block_class_lock
);
367 EXPORT_SYMBOL(unregister_blkdev
);
369 static struct kobj_map
*bdev_map
;
372 * blk_mangle_minor - scatter minor numbers apart
373 * @minor: minor number to mangle
375 * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
376 * is enabled. Mangling twice gives the original value.
384 static int blk_mangle_minor(int minor
)
386 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
389 for (i
= 0; i
< MINORBITS
/ 2; i
++) {
390 int low
= minor
& (1 << i
);
391 int high
= minor
& (1 << (MINORBITS
- 1 - i
));
392 int distance
= MINORBITS
- 1 - 2 * i
;
394 minor
^= low
| high
; /* clear both bits */
395 low
<<= distance
; /* swap the positions */
397 minor
|= low
| high
; /* and set */
404 * blk_alloc_devt - allocate a dev_t for a partition
405 * @part: partition to allocate dev_t for
406 * @devt: out parameter for resulting dev_t
408 * Allocate a dev_t for block device.
411 * 0 on success, allocated dev_t is returned in *@devt. -errno on
417 int blk_alloc_devt(struct hd_struct
*part
, dev_t
*devt
)
419 struct gendisk
*disk
= part_to_disk(part
);
422 /* in consecutive minor range? */
423 if (part
->partno
< disk
->minors
) {
424 *devt
= MKDEV(disk
->major
, disk
->first_minor
+ part
->partno
);
428 /* allocate ext devt */
429 idr_preload(GFP_KERNEL
);
431 spin_lock_bh(&ext_devt_lock
);
432 idx
= idr_alloc(&ext_devt_idr
, part
, 0, NR_EXT_DEVT
, GFP_NOWAIT
);
433 spin_unlock_bh(&ext_devt_lock
);
437 return idx
== -ENOSPC
? -EBUSY
: idx
;
439 *devt
= MKDEV(BLOCK_EXT_MAJOR
, blk_mangle_minor(idx
));
444 * blk_free_devt - free a dev_t
445 * @devt: dev_t to free
447 * Free @devt which was allocated using blk_alloc_devt().
452 void blk_free_devt(dev_t devt
)
454 if (devt
== MKDEV(0, 0))
457 if (MAJOR(devt
) == BLOCK_EXT_MAJOR
) {
458 spin_lock_bh(&ext_devt_lock
);
459 idr_remove(&ext_devt_idr
, blk_mangle_minor(MINOR(devt
)));
460 spin_unlock_bh(&ext_devt_lock
);
464 static char *bdevt_str(dev_t devt
, char *buf
)
466 if (MAJOR(devt
) <= 0xff && MINOR(devt
) <= 0xff) {
467 char tbuf
[BDEVT_SIZE
];
468 snprintf(tbuf
, BDEVT_SIZE
, "%02x%02x", MAJOR(devt
), MINOR(devt
));
469 snprintf(buf
, BDEVT_SIZE
, "%-9s", tbuf
);
471 snprintf(buf
, BDEVT_SIZE
, "%03x:%05x", MAJOR(devt
), MINOR(devt
));
477 * Register device numbers dev..(dev+range-1)
478 * range must be nonzero
479 * The hash chain is sorted on range, so that subranges can override.
481 void blk_register_region(dev_t devt
, unsigned long range
, struct module
*module
,
482 struct kobject
*(*probe
)(dev_t
, int *, void *),
483 int (*lock
)(dev_t
, void *), void *data
)
485 kobj_map(bdev_map
, devt
, range
, module
, probe
, lock
, data
);
488 EXPORT_SYMBOL(blk_register_region
);
490 void blk_unregister_region(dev_t devt
, unsigned long range
)
492 kobj_unmap(bdev_map
, devt
, range
);
495 EXPORT_SYMBOL(blk_unregister_region
);
497 static struct kobject
*exact_match(dev_t devt
, int *partno
, void *data
)
499 struct gendisk
*p
= data
;
501 return &disk_to_dev(p
)->kobj
;
504 static int exact_lock(dev_t devt
, void *data
)
506 struct gendisk
*p
= data
;
513 static void register_disk(struct gendisk
*disk
)
515 struct device
*ddev
= disk_to_dev(disk
);
516 struct block_device
*bdev
;
517 struct disk_part_iter piter
;
518 struct hd_struct
*part
;
521 #ifdef CONFIG_BLOCK_SUPPORT_STLOG
522 int major
= disk
->major
;
523 int first_minor
= disk
->first_minor
;
526 ddev
->parent
= disk
->driverfs_dev
;
528 dev_set_name(ddev
, "%s", disk
->disk_name
);
530 /* delay uevents, until we scanned partition table */
531 dev_set_uevent_suppress(ddev
, 1);
533 if (device_add(ddev
))
535 if (!sysfs_deprecated
) {
536 err
= sysfs_create_link(block_depr
, &ddev
->kobj
,
537 kobject_name(&ddev
->kobj
));
545 * avoid probable deadlock caused by allocating memory with
546 * GFP_KERNEL in runtime_resume callback of its all ancestor
549 pm_runtime_set_memalloc_noio(ddev
, true);
551 disk
->part0
.holder_dir
= kobject_create_and_add("holders", &ddev
->kobj
);
552 disk
->slave_dir
= kobject_create_and_add("slaves", &ddev
->kobj
);
554 /* No minors to use for partitions */
555 if (!disk_part_scan_enabled(disk
))
558 /* No such device (e.g., media were just removed) */
559 if (!get_capacity(disk
))
562 bdev
= bdget_disk(disk
, 0);
566 bdev
->bd_invalidated
= 1;
567 err
= blkdev_get(bdev
, FMODE_READ
, NULL
);
570 blkdev_put(bdev
, FMODE_READ
);
573 /* announce disk after possible partitions are created */
574 dev_set_uevent_suppress(ddev
, 0);
575 kobject_uevent(&ddev
->kobj
, KOBJ_ADD
);
576 ST_LOG("<%s> KOBJ_ADD %d:%d", __func__
, major
, first_minor
);
578 /* announce possible partitions */
579 disk_part_iter_init(&piter
, disk
, 0);
580 while ((part
= disk_part_iter_next(&piter
))) {
581 kobject_uevent(&part_to_dev(part
)->kobj
, KOBJ_ADD
);
582 ST_LOG("<%s> KOBJ_ADD %d:%d", __func__
, major
, first_minor
+ part
->partno
);
584 disk_part_iter_exit(&piter
);
588 * add_disk - add partitioning information to kernel list
589 * @disk: per-device partitioning information
591 * This function registers the partitioning information in @disk
594 * FIXME: error handling
596 void add_disk(struct gendisk
*disk
)
598 struct backing_dev_info
*bdi
;
602 /* minors == 0 indicates to use ext devt from part0 and should
603 * be accompanied with EXT_DEVT flag. Make sure all
604 * parameters make sense.
606 WARN_ON(disk
->minors
&& !(disk
->major
|| disk
->first_minor
));
607 WARN_ON(!disk
->minors
&& !(disk
->flags
& GENHD_FL_EXT_DEVT
));
609 disk
->flags
|= GENHD_FL_UP
;
611 retval
= blk_alloc_devt(&disk
->part0
, &devt
);
616 disk_to_dev(disk
)->devt
= devt
;
618 /* ->major and ->first_minor aren't supposed to be
619 * dereferenced from here on, but set them just in case.
621 disk
->major
= MAJOR(devt
);
622 disk
->first_minor
= MINOR(devt
);
624 disk_alloc_events(disk
);
626 /* Register BDI before referencing it from bdev */
627 bdi
= &disk
->queue
->backing_dev_info
;
628 bdi_register_dev(bdi
, disk_devt(disk
));
630 blk_register_region(disk_devt(disk
), disk
->minors
, NULL
,
631 exact_match
, exact_lock
, disk
);
633 blk_register_queue(disk
);
636 * Take an extra ref on queue which will be put on disk_release()
637 * so that it sticks around as long as @disk is there.
639 WARN_ON_ONCE(!blk_get_queue(disk
->queue
));
641 retval
= sysfs_create_link(&disk_to_dev(disk
)->kobj
, &bdi
->dev
->kobj
,
645 disk_add_events(disk
);
647 EXPORT_SYMBOL(add_disk
);
649 void del_gendisk(struct gendisk
*disk
)
651 struct disk_part_iter piter
;
652 struct hd_struct
*part
;
654 #ifdef CONFIG_BLOCK_SUPPORT_STLOG
658 disk_del_events(disk
);
660 /* invalidate stuff */
661 disk_part_iter_init(&piter
, disk
,
662 DISK_PITER_INCL_EMPTY
| DISK_PITER_REVERSE
);
663 while ((part
= disk_part_iter_next(&piter
))) {
664 invalidate_partition(disk
, part
->partno
);
665 delete_partition(disk
, part
->partno
);
667 disk_part_iter_exit(&piter
);
669 invalidate_partition(disk
, 0);
670 set_capacity(disk
, 0);
671 disk
->flags
&= ~GENHD_FL_UP
;
673 sysfs_remove_link(&disk_to_dev(disk
)->kobj
, "bdi");
674 bdi_unregister(&disk
->queue
->backing_dev_info
);
675 blk_unregister_queue(disk
);
676 blk_unregister_region(disk_devt(disk
), disk
->minors
);
678 part_stat_set_all(&disk
->part0
, 0);
679 disk
->part0
.stamp
= 0;
681 kobject_put(disk
->part0
.holder_dir
);
682 kobject_put(disk
->slave_dir
);
683 if (!sysfs_deprecated
)
684 sysfs_remove_link(block_depr
, dev_name(disk_to_dev(disk
)));
685 pm_runtime_set_memalloc_noio(disk_to_dev(disk
), false);
686 #ifdef CONFIG_BLOCK_SUPPORT_STLOG
687 dev
= disk_to_dev(disk
);
688 ST_LOG("<%s> KOBJ_REMOVE %d:%d %s",
689 __func__
, MAJOR(dev
->devt
), MINOR(dev
->devt
), dev
->kobj
.name
);
692 device_del(disk_to_dev(disk
));
694 EXPORT_SYMBOL(del_gendisk
);
697 * get_gendisk - get partitioning information for a given device
698 * @devt: device to get partitioning information for
699 * @partno: returned partition index
701 * This function gets the structure containing partitioning
702 * information for the given device @devt.
704 struct gendisk
*get_gendisk(dev_t devt
, int *partno
)
706 struct gendisk
*disk
= NULL
;
708 if (MAJOR(devt
) != BLOCK_EXT_MAJOR
) {
709 struct kobject
*kobj
;
711 kobj
= kobj_lookup(bdev_map
, devt
, partno
);
713 disk
= dev_to_disk(kobj_to_dev(kobj
));
715 struct hd_struct
*part
;
717 spin_lock_bh(&ext_devt_lock
);
718 part
= idr_find(&ext_devt_idr
, blk_mangle_minor(MINOR(devt
)));
719 if (part
&& get_disk(part_to_disk(part
))) {
720 *partno
= part
->partno
;
721 disk
= part_to_disk(part
);
723 spin_unlock_bh(&ext_devt_lock
);
728 EXPORT_SYMBOL(get_gendisk
);
731 * bdget_disk - do bdget() by gendisk and partition number
732 * @disk: gendisk of interest
733 * @partno: partition number
735 * Find partition @partno from @disk, do bdget() on it.
741 * Resulting block_device on success, NULL on failure.
743 struct block_device
*bdget_disk(struct gendisk
*disk
, int partno
)
745 struct hd_struct
*part
;
746 struct block_device
*bdev
= NULL
;
748 part
= disk_get_part(disk
, partno
);
750 bdev
= bdget(part_devt(part
));
755 EXPORT_SYMBOL(bdget_disk
);
758 * print a full list of all partitions - intended for places where the root
759 * filesystem can't be mounted and thus to give the victim some idea of what
762 void __init
printk_all_partitions(void)
764 struct class_dev_iter iter
;
767 class_dev_iter_init(&iter
, &block_class
, NULL
, &disk_type
);
768 while ((dev
= class_dev_iter_next(&iter
))) {
769 struct gendisk
*disk
= dev_to_disk(dev
);
770 struct disk_part_iter piter
;
771 struct hd_struct
*part
;
772 char name_buf
[BDEVNAME_SIZE
];
773 char devt_buf
[BDEVT_SIZE
];
776 * Don't show empty devices or things that have been
779 if (get_capacity(disk
) == 0 ||
780 (disk
->flags
& GENHD_FL_SUPPRESS_PARTITION_INFO
))
784 * Note, unlike /proc/partitions, I am showing the
785 * numbers in hex - the same format as the root=
788 disk_part_iter_init(&piter
, disk
, DISK_PITER_INCL_PART0
);
789 while ((part
= disk_part_iter_next(&piter
))) {
790 bool is_part0
= part
== &disk
->part0
;
792 printk("%s%s %10llu %s %s", is_part0
? "" : " ",
793 bdevt_str(part_devt(part
), devt_buf
),
794 (unsigned long long)part_nr_sects_read(part
) >> 1
795 , disk_name(disk
, part
->partno
, name_buf
),
796 part
->info
? part
->info
->uuid
: "");
798 if (disk
->driverfs_dev
!= NULL
&&
799 disk
->driverfs_dev
->driver
!= NULL
)
800 printk(" driver: %s\n",
801 disk
->driverfs_dev
->driver
->name
);
803 printk(" (driver?)\n");
807 disk_part_iter_exit(&piter
);
809 class_dev_iter_exit(&iter
);
812 #ifdef CONFIG_PROC_FS
814 static void *disk_seqf_start(struct seq_file
*seqf
, loff_t
*pos
)
817 struct class_dev_iter
*iter
;
820 iter
= kmalloc(sizeof(*iter
), GFP_KERNEL
);
822 return ERR_PTR(-ENOMEM
);
824 seqf
->private = iter
;
825 class_dev_iter_init(iter
, &block_class
, NULL
, &disk_type
);
827 dev
= class_dev_iter_next(iter
);
832 return dev_to_disk(dev
);
835 static void *disk_seqf_next(struct seq_file
*seqf
, void *v
, loff_t
*pos
)
840 dev
= class_dev_iter_next(seqf
->private);
842 return dev_to_disk(dev
);
847 static void disk_seqf_stop(struct seq_file
*seqf
, void *v
)
849 struct class_dev_iter
*iter
= seqf
->private;
851 /* stop is called even after start failed :-( */
853 class_dev_iter_exit(iter
);
855 seqf
->private = NULL
;
859 static void *show_partition_start(struct seq_file
*seqf
, loff_t
*pos
)
863 p
= disk_seqf_start(seqf
, pos
);
864 if (!IS_ERR_OR_NULL(p
) && !*pos
)
865 seq_puts(seqf
, "major minor #blocks name\n\n");
869 static int show_partition(struct seq_file
*seqf
, void *v
)
871 struct gendisk
*sgp
= v
;
872 struct disk_part_iter piter
;
873 struct hd_struct
*part
;
874 char buf
[BDEVNAME_SIZE
];
876 /* Don't show non-partitionable removeable devices or empty devices */
877 if (!get_capacity(sgp
) || (!disk_max_parts(sgp
) &&
878 (sgp
->flags
& GENHD_FL_REMOVABLE
)))
880 if (sgp
->flags
& GENHD_FL_SUPPRESS_PARTITION_INFO
)
883 /* show the full disk and all non-0 size partitions of it */
884 disk_part_iter_init(&piter
, sgp
, DISK_PITER_INCL_PART0
);
885 while ((part
= disk_part_iter_next(&piter
)))
886 seq_printf(seqf
, "%4d %7d %10llu %s\n",
887 MAJOR(part_devt(part
)), MINOR(part_devt(part
)),
888 (unsigned long long)part_nr_sects_read(part
) >> 1,
889 disk_name(sgp
, part
->partno
, buf
));
890 disk_part_iter_exit(&piter
);
895 static const struct seq_operations partitions_op
= {
896 .start
= show_partition_start
,
897 .next
= disk_seqf_next
,
898 .stop
= disk_seqf_stop
,
899 .show
= show_partition
902 static int partitions_open(struct inode
*inode
, struct file
*file
)
904 return seq_open(file
, &partitions_op
);
907 static const struct file_operations proc_partitions_operations
= {
908 .open
= partitions_open
,
911 .release
= seq_release
,
916 static struct kobject
*base_probe(dev_t devt
, int *partno
, void *data
)
918 if (request_module("block-major-%d-%d", MAJOR(devt
), MINOR(devt
)) > 0)
919 /* Make old-style 2.4 aliases work */
920 request_module("block-major-%d", MAJOR(devt
));
924 static int __init
genhd_device_init(void)
928 block_class
.dev_kobj
= sysfs_dev_block_kobj
;
929 error
= class_register(&block_class
);
932 bdev_map
= kobj_map_init(base_probe
, &block_class_lock
);
935 register_blkdev(BLOCK_EXT_MAJOR
, "blkext");
937 /* create top-level block dir */
938 if (!sysfs_deprecated
)
939 block_depr
= kobject_create_and_add("block", NULL
);
943 subsys_initcall(genhd_device_init
);
945 static ssize_t
disk_range_show(struct device
*dev
,
946 struct device_attribute
*attr
, char *buf
)
948 struct gendisk
*disk
= dev_to_disk(dev
);
950 return sprintf(buf
, "%d\n", disk
->minors
);
953 static ssize_t
disk_ext_range_show(struct device
*dev
,
954 struct device_attribute
*attr
, char *buf
)
956 struct gendisk
*disk
= dev_to_disk(dev
);
958 return sprintf(buf
, "%d\n", disk_max_parts(disk
));
961 static ssize_t
disk_removable_show(struct device
*dev
,
962 struct device_attribute
*attr
, char *buf
)
964 struct gendisk
*disk
= dev_to_disk(dev
);
966 return sprintf(buf
, "%d\n",
967 (disk
->flags
& GENHD_FL_REMOVABLE
? 1 : 0));
970 static ssize_t
disk_ro_show(struct device
*dev
,
971 struct device_attribute
*attr
, char *buf
)
973 struct gendisk
*disk
= dev_to_disk(dev
);
975 return sprintf(buf
, "%d\n", get_disk_ro(disk
) ? 1 : 0);
978 static ssize_t
disk_capability_show(struct device
*dev
,
979 struct device_attribute
*attr
, char *buf
)
981 struct gendisk
*disk
= dev_to_disk(dev
);
983 return sprintf(buf
, "%x\n", disk
->flags
);
986 static ssize_t
disk_alignment_offset_show(struct device
*dev
,
987 struct device_attribute
*attr
,
990 struct gendisk
*disk
= dev_to_disk(dev
);
992 return sprintf(buf
, "%d\n", queue_alignment_offset(disk
->queue
));
995 static ssize_t
disk_discard_alignment_show(struct device
*dev
,
996 struct device_attribute
*attr
,
999 struct gendisk
*disk
= dev_to_disk(dev
);
1001 return sprintf(buf
, "%d\n", queue_discard_alignment(disk
->queue
));
1004 static DEVICE_ATTR(range
, S_IRUGO
, disk_range_show
, NULL
);
1005 static DEVICE_ATTR(ext_range
, S_IRUGO
, disk_ext_range_show
, NULL
);
1006 static DEVICE_ATTR(removable
, S_IRUGO
, disk_removable_show
, NULL
);
1007 static DEVICE_ATTR(ro
, S_IRUGO
, disk_ro_show
, NULL
);
1008 static DEVICE_ATTR(size
, S_IRUGO
, part_size_show
, NULL
);
1009 static DEVICE_ATTR(alignment_offset
, S_IRUGO
, disk_alignment_offset_show
, NULL
);
1010 static DEVICE_ATTR(discard_alignment
, S_IRUGO
, disk_discard_alignment_show
,
1012 static DEVICE_ATTR(capability
, S_IRUGO
, disk_capability_show
, NULL
);
1013 static DEVICE_ATTR(stat
, S_IRUGO
, part_stat_show
, NULL
);
1014 static DEVICE_ATTR(inflight
, S_IRUGO
, part_inflight_show
, NULL
);
1015 #ifdef CONFIG_FAIL_MAKE_REQUEST
1016 static struct device_attribute dev_attr_fail
=
1017 __ATTR(make
-it
-fail
, S_IRUGO
|S_IWUSR
, part_fail_show
, part_fail_store
);
1019 #ifdef CONFIG_FAIL_IO_TIMEOUT
1020 static struct device_attribute dev_attr_fail_timeout
=
1021 __ATTR(io
-timeout
-fail
, S_IRUGO
|S_IWUSR
, part_timeout_show
,
1022 part_timeout_store
);
1025 static struct attribute
*disk_attrs
[] = {
1026 &dev_attr_range
.attr
,
1027 &dev_attr_ext_range
.attr
,
1028 &dev_attr_removable
.attr
,
1030 &dev_attr_size
.attr
,
1031 &dev_attr_alignment_offset
.attr
,
1032 &dev_attr_discard_alignment
.attr
,
1033 &dev_attr_capability
.attr
,
1034 &dev_attr_stat
.attr
,
1035 &dev_attr_inflight
.attr
,
1036 #ifdef CONFIG_FAIL_MAKE_REQUEST
1037 &dev_attr_fail
.attr
,
1039 #ifdef CONFIG_FAIL_IO_TIMEOUT
1040 &dev_attr_fail_timeout
.attr
,
1045 static struct attribute_group disk_attr_group
= {
1046 .attrs
= disk_attrs
,
1049 static const struct attribute_group
*disk_attr_groups
[] = {
1055 * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
1056 * @disk: disk to replace part_tbl for
1057 * @new_ptbl: new part_tbl to install
1059 * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The
1060 * original ptbl is freed using RCU callback.
1063 * Matching bd_mutx locked.
1065 static void disk_replace_part_tbl(struct gendisk
*disk
,
1066 struct disk_part_tbl
*new_ptbl
)
1068 struct disk_part_tbl
*old_ptbl
= disk
->part_tbl
;
1070 rcu_assign_pointer(disk
->part_tbl
, new_ptbl
);
1073 rcu_assign_pointer(old_ptbl
->last_lookup
, NULL
);
1074 kfree_rcu(old_ptbl
, rcu_head
);
1079 * disk_expand_part_tbl - expand disk->part_tbl
1080 * @disk: disk to expand part_tbl for
1081 * @partno: expand such that this partno can fit in
1083 * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl
1084 * uses RCU to allow unlocked dereferencing for stats and other stuff.
1087 * Matching bd_mutex locked, might sleep.
1090 * 0 on success, -errno on failure.
1092 int disk_expand_part_tbl(struct gendisk
*disk
, int partno
)
1094 struct disk_part_tbl
*old_ptbl
= disk
->part_tbl
;
1095 struct disk_part_tbl
*new_ptbl
;
1096 int len
= old_ptbl
? old_ptbl
->len
: 0;
1101 * check for int overflow, since we can get here from blkpg_ioctl()
1102 * with a user passed 'partno'.
1104 target
= partno
+ 1;
1108 /* disk_max_parts() is zero during initialization, ignore if so */
1109 if (disk_max_parts(disk
) && target
> disk_max_parts(disk
))
1115 size
= sizeof(*new_ptbl
) + target
* sizeof(new_ptbl
->part
[0]);
1116 new_ptbl
= kzalloc_node(size
, GFP_KERNEL
, disk
->node_id
);
1120 new_ptbl
->len
= target
;
1122 for (i
= 0; i
< len
; i
++)
1123 rcu_assign_pointer(new_ptbl
->part
[i
], old_ptbl
->part
[i
]);
1125 disk_replace_part_tbl(disk
, new_ptbl
);
1129 static void disk_release(struct device
*dev
)
1131 struct gendisk
*disk
= dev_to_disk(dev
);
1133 blk_free_devt(dev
->devt
);
1134 disk_release_events(disk
);
1135 kfree(disk
->random
);
1136 disk_replace_part_tbl(disk
, NULL
);
1137 free_part_stats(&disk
->part0
);
1138 free_part_info(&disk
->part0
);
1140 blk_put_queue(disk
->queue
);
1144 static int disk_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
1146 struct gendisk
*disk
= dev_to_disk(dev
);
1147 struct disk_part_iter piter
;
1148 struct hd_struct
*part
;
1151 disk_part_iter_init(&piter
, disk
, 0);
1152 while((part
= disk_part_iter_next(&piter
)))
1154 disk_part_iter_exit(&piter
);
1155 add_uevent_var(env
, "NPARTS=%u", cnt
);
1156 #ifdef CONFIG_USB_STORAGE_DETECT
1157 if (disk
->flags
& GENHD_FL_IF_USB
) {
1158 add_uevent_var(env
, "MEDIAPRST=%d",
1159 (disk
->flags
& GENHD_FL_MEDIA_PRESENT
) ? 1 : 0);
1160 pr_info("%s %d, disk flag media_present=%d, cnt=%d\n",
1162 (disk
->flags
& GENHD_FL_MEDIA_PRESENT
), cnt
);
1168 struct class block_class
= {
1172 static char *block_devnode(struct device
*dev
, umode_t
*mode
,
1173 kuid_t
*uid
, kgid_t
*gid
)
1175 struct gendisk
*disk
= dev_to_disk(dev
);
1178 return disk
->devnode(disk
, mode
);
1182 static struct device_type disk_type
= {
1184 .groups
= disk_attr_groups
,
1185 .release
= disk_release
,
1186 .devnode
= block_devnode
,
1187 .uevent
= disk_uevent
,
1190 #ifdef CONFIG_PROC_FS
1192 * aggregate disk stat collector. Uses the same stats that the sysfs
1193 * entries do, above, but makes them available through one seq_file.
1195 * The output looks suspiciously like /proc/partitions with a bunch of
1198 static int diskstats_show(struct seq_file
*seqf
, void *v
)
1200 struct gendisk
*gp
= v
;
1201 struct disk_part_iter piter
;
1202 struct hd_struct
*hd
;
1203 char buf
[BDEVNAME_SIZE
];
1207 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1208 seq_puts(seqf, "major minor name"
1209 " rio rmerge rsect ruse wio wmerge "
1210 "wsect wuse running use aveq"
1214 disk_part_iter_init(&piter
, gp
, DISK_PITER_INCL_EMPTY_PART0
);
1215 while ((hd
= disk_part_iter_next(&piter
))) {
1216 cpu
= part_stat_lock();
1217 part_round_stats(cpu
, hd
);
1219 seq_printf(seqf
, "%4d %7d %s %lu %lu %lu "
1220 "%u %lu %lu %lu %u %u %u %u\n",
1221 MAJOR(part_devt(hd
)), MINOR(part_devt(hd
)),
1222 disk_name(gp
, hd
->partno
, buf
),
1223 part_stat_read(hd
, ios
[READ
]),
1224 part_stat_read(hd
, merges
[READ
]),
1225 part_stat_read(hd
, sectors
[READ
]),
1226 jiffies_to_msecs(part_stat_read(hd
, ticks
[READ
])),
1227 part_stat_read(hd
, ios
[WRITE
]),
1228 part_stat_read(hd
, merges
[WRITE
]),
1229 part_stat_read(hd
, sectors
[WRITE
]),
1230 jiffies_to_msecs(part_stat_read(hd
, ticks
[WRITE
])),
1232 jiffies_to_msecs(part_stat_read(hd
, io_ticks
)),
1233 jiffies_to_msecs(part_stat_read(hd
, time_in_queue
))
1236 disk_part_iter_exit(&piter
);
1241 static const struct seq_operations diskstats_op
= {
1242 .start
= disk_seqf_start
,
1243 .next
= disk_seqf_next
,
1244 .stop
= disk_seqf_stop
,
1245 .show
= diskstats_show
1248 static int diskstats_open(struct inode
*inode
, struct file
*file
)
1250 return seq_open(file
, &diskstats_op
);
1253 static const struct file_operations proc_diskstats_operations
= {
1254 .open
= diskstats_open
,
1256 .llseek
= seq_lseek
,
1257 .release
= seq_release
,
1260 #define PG2KB(x) ((unsigned long)((x) << (PAGE_SHIFT - 10)))
1261 static int iostats_show(struct seq_file
*seqf
, void *v
)
1263 struct gendisk
*gp
= v
;
1264 struct disk_part_iter piter
;
1265 struct hd_struct
*hd
;
1266 char buf
[BDEVNAME_SIZE
];
1269 unsigned long thresh
= 0;
1270 unsigned long bg_thresh
= 0;
1271 struct backing_dev_info
*bdi
;
1272 unsigned int nread
, nwrite
;
1274 /* Enhanced diskstats for IOD V 2.2 */
1275 global_dirty_limits(&bg_thresh
, &thresh
);
1277 disk_part_iter_init(&piter
, gp
, DISK_PITER_INCL_EMPTY_PART0
);
1278 while ((hd
= disk_part_iter_next(&piter
))) {
1279 cpu
= part_stat_lock();
1280 part_round_stats(cpu
, hd
);
1282 uptime
= ktime_to_ns(ktime_get());
1283 uptime
/= 1000000; /* in ms */
1284 bdi
= &gp
->queue
->backing_dev_info
;
1285 nread
= part_in_flight_read(hd
);
1286 nwrite
= part_in_flight_write(hd
);
1287 seq_printf(seqf
, "%4d %7d %s %lu %lu %lu %u "
1288 "%lu %lu %lu %u %u %u %u "
1291 "%u %llu %lu %lu %lu %u "
1293 MAJOR(part_devt(hd
)), MINOR(part_devt(hd
)),
1294 disk_name(gp
, hd
->partno
, buf
),
1295 part_stat_read(hd
, ios
[READ
]),
1296 part_stat_read(hd
, merges
[READ
]),
1297 part_stat_read(hd
, sectors
[READ
]),
1298 jiffies_to_msecs(part_stat_read(hd
, ticks
[READ
])),
1300 part_stat_read(hd
, ios
[WRITE
]),
1301 part_stat_read(hd
, merges
[WRITE
]),
1302 part_stat_read(hd
, sectors
[WRITE
]),
1303 jiffies_to_msecs(part_stat_read(hd
, ticks
[WRITE
])),
1304 /*part_in_flight(hd),*/
1306 jiffies_to_msecs(part_stat_read(hd
, io_ticks
)),
1307 jiffies_to_msecs(part_stat_read(hd
, time_in_queue
)),
1308 /* followings are added */
1309 part_stat_read(hd
, discard_ios
),
1310 part_stat_read(hd
, discard_sectors
),
1311 part_stat_read(hd
, flush_ios
),
1312 gp
->queue
->flush_ios
,
1315 gp
->queue
->in_flight_time
/ USEC_PER_MSEC
,
1317 PG2KB(bdi
->last_thresh
),
1318 PG2KB(bdi
->last_nr_dirty
),
1319 jiffies_to_msecs(bdi
->paused_total
),
1321 (unsigned long)(uptime
/ 1000),
1322 (unsigned long)(uptime
% 1000)
1325 disk_part_iter_exit(&piter
);
1330 static const struct seq_operations iostats_op
= {
1331 .start
= disk_seqf_start
,
1332 .next
= disk_seqf_next
,
1333 .stop
= disk_seqf_stop
,
1334 .show
= iostats_show
1337 static int iostats_open(struct inode
*inode
, struct file
*file
)
1339 return seq_open(file
, &iostats_op
);
1342 static const struct file_operations proc_iostats_operations
= {
1343 .open
= iostats_open
,
1345 .llseek
= seq_lseek
,
1346 .release
= seq_release
,
1349 static int __init
proc_genhd_init(void)
1351 proc_create("iostats", 0, NULL
, &proc_iostats_operations
);
1352 proc_create("diskstats", 0, NULL
, &proc_diskstats_operations
);
1353 proc_create("partitions", 0, NULL
, &proc_partitions_operations
);
1356 module_init(proc_genhd_init
);
1357 #endif /* CONFIG_PROC_FS */
1359 dev_t
blk_lookup_devt(const char *name
, int partno
)
1361 dev_t devt
= MKDEV(0, 0);
1362 struct class_dev_iter iter
;
1365 class_dev_iter_init(&iter
, &block_class
, NULL
, &disk_type
);
1366 while ((dev
= class_dev_iter_next(&iter
))) {
1367 struct gendisk
*disk
= dev_to_disk(dev
);
1368 struct hd_struct
*part
;
1370 if (strcmp(dev_name(dev
), name
))
1373 if (partno
< disk
->minors
) {
1374 /* We need to return the right devno, even
1375 * if the partition doesn't exist yet.
1377 devt
= MKDEV(MAJOR(dev
->devt
),
1378 MINOR(dev
->devt
) + partno
);
1381 part
= disk_get_part(disk
, partno
);
1383 devt
= part_devt(part
);
1384 disk_put_part(part
);
1387 disk_put_part(part
);
1389 class_dev_iter_exit(&iter
);
1392 EXPORT_SYMBOL(blk_lookup_devt
);
1394 struct gendisk
*alloc_disk(int minors
)
1396 return alloc_disk_node(minors
, NUMA_NO_NODE
);
1398 EXPORT_SYMBOL(alloc_disk
);
1400 struct gendisk
*alloc_disk_node(int minors
, int node_id
)
1402 struct gendisk
*disk
;
1404 disk
= kmalloc_node(sizeof(struct gendisk
),
1405 GFP_KERNEL
| __GFP_ZERO
, node_id
);
1407 if (!init_part_stats(&disk
->part0
)) {
1411 disk
->node_id
= node_id
;
1412 if (disk_expand_part_tbl(disk
, 0)) {
1413 free_part_stats(&disk
->part0
);
1417 disk
->part_tbl
->part
[0] = &disk
->part0
;
1420 * set_capacity() and get_capacity() currently don't use
1421 * seqcounter to read/update the part0->nr_sects. Still init
1422 * the counter as we can read the sectors in IO submission
1423 * patch using seqence counters.
1425 * TODO: Ideally set_capacity() and get_capacity() should be
1426 * converted to make use of bd_mutex and sequence counters.
1428 seqcount_init(&disk
->part0
.nr_sects_seq
);
1429 hd_ref_init(&disk
->part0
);
1431 disk
->minors
= minors
;
1432 rand_initialize_disk(disk
);
1433 disk_to_dev(disk
)->class = &block_class
;
1434 disk_to_dev(disk
)->type
= &disk_type
;
1435 device_initialize(disk_to_dev(disk
));
1439 EXPORT_SYMBOL(alloc_disk_node
);
1441 struct kobject
*get_disk(struct gendisk
*disk
)
1443 struct module
*owner
;
1444 struct kobject
*kobj
;
1448 owner
= disk
->fops
->owner
;
1449 if (owner
&& !try_module_get(owner
))
1451 kobj
= kobject_get(&disk_to_dev(disk
)->kobj
);
1460 EXPORT_SYMBOL(get_disk
);
1462 void put_disk(struct gendisk
*disk
)
1465 kobject_put(&disk_to_dev(disk
)->kobj
);
1468 EXPORT_SYMBOL(put_disk
);
1470 static void set_disk_ro_uevent(struct gendisk
*gd
, int ro
)
1472 char event
[] = "DISK_RO=1";
1473 char *envp
[] = { event
, NULL
};
1477 kobject_uevent_env(&disk_to_dev(gd
)->kobj
, KOBJ_CHANGE
, envp
);
1480 void set_device_ro(struct block_device
*bdev
, int flag
)
1482 bdev
->bd_part
->policy
= flag
;
1485 EXPORT_SYMBOL(set_device_ro
);
1487 void set_disk_ro(struct gendisk
*disk
, int flag
)
1489 struct disk_part_iter piter
;
1490 struct hd_struct
*part
;
1492 if (disk
->part0
.policy
!= flag
) {
1493 set_disk_ro_uevent(disk
, flag
);
1494 disk
->part0
.policy
= flag
;
1497 disk_part_iter_init(&piter
, disk
, DISK_PITER_INCL_EMPTY
);
1498 while ((part
= disk_part_iter_next(&piter
)))
1499 part
->policy
= flag
;
1500 disk_part_iter_exit(&piter
);
1503 EXPORT_SYMBOL(set_disk_ro
);
1505 int bdev_read_only(struct block_device
*bdev
)
1509 return bdev
->bd_part
->policy
;
1512 EXPORT_SYMBOL(bdev_read_only
);
1514 int invalidate_partition(struct gendisk
*disk
, int partno
)
1517 struct block_device
*bdev
= bdget_disk(disk
, partno
);
1520 res
= __invalidate_device(bdev
, true);
1526 EXPORT_SYMBOL(invalidate_partition
);
1529 * Disk events - monitor disk events like media change and eject request.
1531 struct disk_events
{
1532 struct list_head node
; /* all disk_event's */
1533 struct gendisk
*disk
; /* the associated disk */
1536 struct mutex block_mutex
; /* protects blocking */
1537 int block
; /* event blocking depth */
1538 unsigned int pending
; /* events already sent out */
1539 unsigned int clearing
; /* events being cleared */
1541 long poll_msecs
; /* interval, -1 for default */
1542 struct delayed_work dwork
;
1545 static const char *disk_events_strs
[] = {
1546 [ilog2(DISK_EVENT_MEDIA_CHANGE
)] = "media_change",
1547 [ilog2(DISK_EVENT_EJECT_REQUEST
)] = "eject_request",
1550 static char *disk_uevents
[] = {
1551 [ilog2(DISK_EVENT_MEDIA_CHANGE
)] = "DISK_MEDIA_CHANGE=1",
1552 [ilog2(DISK_EVENT_EJECT_REQUEST
)] = "DISK_EJECT_REQUEST=1",
1555 /* list of all disk_events */
1556 static DEFINE_MUTEX(disk_events_mutex
);
1557 static LIST_HEAD(disk_events
);
1559 /* disable in-kernel polling by default */
1560 static unsigned long disk_events_dfl_poll_msecs
= 0;
1562 static unsigned long disk_events_poll_jiffies(struct gendisk
*disk
)
1564 struct disk_events
*ev
= disk
->ev
;
1565 long intv_msecs
= 0;
1568 * If device-specific poll interval is set, always use it. If
1569 * the default is being used, poll iff there are events which
1570 * can't be monitored asynchronously.
1572 if (ev
->poll_msecs
>= 0)
1573 intv_msecs
= ev
->poll_msecs
;
1574 else if (disk
->events
& ~disk
->async_events
)
1575 intv_msecs
= disk_events_dfl_poll_msecs
;
1577 return msecs_to_jiffies(intv_msecs
);
1581 * disk_block_events - block and flush disk event checking
1582 * @disk: disk to block events for
1584 * On return from this function, it is guaranteed that event checking
1585 * isn't in progress and won't happen until unblocked by
1586 * disk_unblock_events(). Events blocking is counted and the actual
1587 * unblocking happens after the matching number of unblocks are done.
1589 * Note that this intentionally does not block event checking from
1590 * disk_clear_events().
1595 void disk_block_events(struct gendisk
*disk
)
1597 struct disk_events
*ev
= disk
->ev
;
1598 unsigned long flags
;
1605 * Outer mutex ensures that the first blocker completes canceling
1606 * the event work before further blockers are allowed to finish.
1608 mutex_lock(&ev
->block_mutex
);
1610 spin_lock_irqsave(&ev
->lock
, flags
);
1611 cancel
= !ev
->block
++;
1612 spin_unlock_irqrestore(&ev
->lock
, flags
);
1615 cancel_delayed_work_sync(&disk
->ev
->dwork
);
1617 mutex_unlock(&ev
->block_mutex
);
1620 static void __disk_unblock_events(struct gendisk
*disk
, bool check_now
)
1622 struct disk_events
*ev
= disk
->ev
;
1624 unsigned long flags
;
1626 spin_lock_irqsave(&ev
->lock
, flags
);
1628 if (WARN_ON_ONCE(ev
->block
<= 0))
1635 * Not exactly a latency critical operation, set poll timer
1636 * slack to 25% and kick event check.
1638 intv
= disk_events_poll_jiffies(disk
);
1639 set_timer_slack(&ev
->dwork
.timer
, intv
/ 4);
1641 queue_delayed_work(system_freezable_power_efficient_wq
,
1644 queue_delayed_work(system_freezable_power_efficient_wq
,
1647 spin_unlock_irqrestore(&ev
->lock
, flags
);
1651 * disk_unblock_events - unblock disk event checking
1652 * @disk: disk to unblock events for
1654 * Undo disk_block_events(). When the block count reaches zero, it
1655 * starts events polling if configured.
1658 * Don't care. Safe to call from irq context.
1660 void disk_unblock_events(struct gendisk
*disk
)
1663 __disk_unblock_events(disk
, false);
1667 * disk_flush_events - schedule immediate event checking and flushing
1668 * @disk: disk to check and flush events for
1669 * @mask: events to flush
1671 * Schedule immediate event checking on @disk if not blocked. Events in
1672 * @mask are scheduled to be cleared from the driver. Note that this
1673 * doesn't clear the events from @disk->ev.
1676 * If @mask is non-zero must be called with bdev->bd_mutex held.
1678 void disk_flush_events(struct gendisk
*disk
, unsigned int mask
)
1680 struct disk_events
*ev
= disk
->ev
;
1685 spin_lock_irq(&ev
->lock
);
1686 ev
->clearing
|= mask
;
1688 mod_delayed_work(system_freezable_power_efficient_wq
,
1690 spin_unlock_irq(&ev
->lock
);
1694 * disk_clear_events - synchronously check, clear and return pending events
1695 * @disk: disk to fetch and clear events from
1696 * @mask: mask of events to be fetched and clearted
1698 * Disk events are synchronously checked and pending events in @mask
1699 * are cleared and returned. This ignores the block count.
1704 unsigned int disk_clear_events(struct gendisk
*disk
, unsigned int mask
)
1706 const struct block_device_operations
*bdops
= disk
->fops
;
1707 struct disk_events
*ev
= disk
->ev
;
1708 unsigned int pending
;
1709 unsigned int clearing
= mask
;
1712 /* for drivers still using the old ->media_changed method */
1713 if ((mask
& DISK_EVENT_MEDIA_CHANGE
) &&
1714 bdops
->media_changed
&& bdops
->media_changed(disk
))
1715 return DISK_EVENT_MEDIA_CHANGE
;
1719 disk_block_events(disk
);
1722 * store the union of mask and ev->clearing on the stack so that the
1723 * race with disk_flush_events does not cause ambiguity (ev->clearing
1724 * can still be modified even if events are blocked).
1726 spin_lock_irq(&ev
->lock
);
1727 clearing
|= ev
->clearing
;
1729 spin_unlock_irq(&ev
->lock
);
1731 disk_check_events(ev
, &clearing
);
1733 * if ev->clearing is not 0, the disk_flush_events got called in the
1734 * middle of this function, so we want to run the workfn without delay.
1736 __disk_unblock_events(disk
, ev
->clearing
? true : false);
1738 /* then, fetch and clear pending events */
1739 spin_lock_irq(&ev
->lock
);
1740 pending
= ev
->pending
& mask
;
1741 ev
->pending
&= ~mask
;
1742 spin_unlock_irq(&ev
->lock
);
1743 WARN_ON_ONCE(clearing
& mask
);
1749 * Separate this part out so that a different pointer for clearing_ptr can be
1750 * passed in for disk_clear_events.
1752 static void disk_events_workfn(struct work_struct
*work
)
1754 struct delayed_work
*dwork
= to_delayed_work(work
);
1755 struct disk_events
*ev
= container_of(dwork
, struct disk_events
, dwork
);
1757 disk_check_events(ev
, &ev
->clearing
);
1760 static void disk_check_events(struct disk_events
*ev
,
1761 unsigned int *clearing_ptr
)
1763 struct gendisk
*disk
= ev
->disk
;
1764 char *envp
[ARRAY_SIZE(disk_uevents
) + 1] = { };
1765 unsigned int clearing
= *clearing_ptr
;
1766 unsigned int events
;
1768 int nr_events
= 0, i
;
1770 #ifdef CONFIG_USB_STORAGE_DETECT
1771 if (!(disk
->flags
& GENHD_FL_IF_USB
))
1773 events
= disk
->fops
->check_events(disk
, clearing
);
1777 events
= disk
->fops
->check_events(disk
, clearing
);
1780 /* accumulate pending events and schedule next poll if necessary */
1781 spin_lock_irq(&ev
->lock
);
1783 events
&= ~ev
->pending
;
1784 ev
->pending
|= events
;
1785 *clearing_ptr
&= ~clearing
;
1787 intv
= disk_events_poll_jiffies(disk
);
1788 if (!ev
->block
&& intv
)
1789 queue_delayed_work(system_freezable_power_efficient_wq
,
1792 spin_unlock_irq(&ev
->lock
);
1795 * Tell userland about new events. Only the events listed in
1796 * @disk->events are reported. Unlisted events are processed the
1797 * same internally but never get reported to userland.
1799 for (i
= 0; i
< ARRAY_SIZE(disk_uevents
); i
++)
1800 if (events
& disk
->events
& (1 << i
))
1801 envp
[nr_events
++] = disk_uevents
[i
];
1803 #ifdef CONFIG_USB_STORAGE_DETECT
1804 if (!(disk
->flags
& GENHD_FL_IF_USB
)) {
1806 kobject_uevent_env(&disk_to_dev(disk
)->kobj
,
1811 kobject_uevent_env(&disk_to_dev(disk
)->kobj
,
1817 * A disk events enabled device has the following sysfs nodes under
1818 * its /sys/block/X/ directory.
1820 * events : list of all supported events
1821 * events_async : list of events which can be detected w/o polling
1822 * events_poll_msecs : polling interval, 0: disable, -1: system default
1824 static ssize_t
__disk_events_show(unsigned int events
, char *buf
)
1826 const char *delim
= "";
1830 for (i
= 0; i
< ARRAY_SIZE(disk_events_strs
); i
++)
1831 if (events
& (1 << i
)) {
1832 pos
+= sprintf(buf
+ pos
, "%s%s",
1833 delim
, disk_events_strs
[i
]);
1837 pos
+= sprintf(buf
+ pos
, "\n");
1841 static ssize_t
disk_events_show(struct device
*dev
,
1842 struct device_attribute
*attr
, char *buf
)
1844 struct gendisk
*disk
= dev_to_disk(dev
);
1846 return __disk_events_show(disk
->events
, buf
);
1849 static ssize_t
disk_events_async_show(struct device
*dev
,
1850 struct device_attribute
*attr
, char *buf
)
1852 struct gendisk
*disk
= dev_to_disk(dev
);
1854 return __disk_events_show(disk
->async_events
, buf
);
1857 static ssize_t
disk_events_poll_msecs_show(struct device
*dev
,
1858 struct device_attribute
*attr
,
1861 struct gendisk
*disk
= dev_to_disk(dev
);
1863 return sprintf(buf
, "%ld\n", disk
->ev
->poll_msecs
);
1866 static ssize_t
disk_events_poll_msecs_store(struct device
*dev
,
1867 struct device_attribute
*attr
,
1868 const char *buf
, size_t count
)
1870 struct gendisk
*disk
= dev_to_disk(dev
);
1873 if (!count
|| !sscanf(buf
, "%ld", &intv
))
1876 if (intv
< 0 && intv
!= -1)
1879 disk_block_events(disk
);
1880 disk
->ev
->poll_msecs
= intv
;
1881 __disk_unblock_events(disk
, true);
1886 static const DEVICE_ATTR(events
, S_IRUGO
, disk_events_show
, NULL
);
1887 static const DEVICE_ATTR(events_async
, S_IRUGO
, disk_events_async_show
, NULL
);
1888 static const DEVICE_ATTR(events_poll_msecs
, S_IRUGO
|S_IWUSR
,
1889 disk_events_poll_msecs_show
,
1890 disk_events_poll_msecs_store
);
1892 static const struct attribute
*disk_events_attrs
[] = {
1893 &dev_attr_events
.attr
,
1894 &dev_attr_events_async
.attr
,
1895 &dev_attr_events_poll_msecs
.attr
,
1900 * The default polling interval can be specified by the kernel
1901 * parameter block.events_dfl_poll_msecs which defaults to 0
1902 * (disable). This can also be modified runtime by writing to
1903 * /sys/module/block/events_dfl_poll_msecs.
1905 static int disk_events_set_dfl_poll_msecs(const char *val
,
1906 const struct kernel_param
*kp
)
1908 struct disk_events
*ev
;
1911 ret
= param_set_ulong(val
, kp
);
1915 mutex_lock(&disk_events_mutex
);
1917 list_for_each_entry(ev
, &disk_events
, node
)
1918 disk_flush_events(ev
->disk
, 0);
1920 mutex_unlock(&disk_events_mutex
);
1925 static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops
= {
1926 .set
= disk_events_set_dfl_poll_msecs
,
1927 .get
= param_get_ulong
,
1930 #undef MODULE_PARAM_PREFIX
1931 #define MODULE_PARAM_PREFIX "block."
1933 module_param_cb(events_dfl_poll_msecs
, &disk_events_dfl_poll_msecs_param_ops
,
1934 &disk_events_dfl_poll_msecs
, 0644);
1937 * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
1939 static void disk_alloc_events(struct gendisk
*disk
)
1941 struct disk_events
*ev
;
1943 if (!disk
->fops
->check_events
)
1946 ev
= kzalloc(sizeof(*ev
), GFP_KERNEL
);
1948 pr_warn("%s: failed to initialize events\n", disk
->disk_name
);
1952 INIT_LIST_HEAD(&ev
->node
);
1954 spin_lock_init(&ev
->lock
);
1955 mutex_init(&ev
->block_mutex
);
1957 ev
->poll_msecs
= -1;
1958 INIT_DELAYED_WORK(&ev
->dwork
, disk_events_workfn
);
1963 static void disk_add_events(struct gendisk
*disk
)
1968 /* FIXME: error handling */
1969 if (sysfs_create_files(&disk_to_dev(disk
)->kobj
, disk_events_attrs
) < 0)
1970 pr_warn("%s: failed to create sysfs files for events\n",
1973 mutex_lock(&disk_events_mutex
);
1974 list_add_tail(&disk
->ev
->node
, &disk_events
);
1975 mutex_unlock(&disk_events_mutex
);
1978 * Block count is initialized to 1 and the following initial
1979 * unblock kicks it into action.
1981 __disk_unblock_events(disk
, true);
1984 static void disk_del_events(struct gendisk
*disk
)
1989 disk_block_events(disk
);
1991 mutex_lock(&disk_events_mutex
);
1992 list_del_init(&disk
->ev
->node
);
1993 mutex_unlock(&disk_events_mutex
);
1995 sysfs_remove_files(&disk_to_dev(disk
)->kobj
, disk_events_attrs
);
1998 static void disk_release_events(struct gendisk
*disk
)
2000 /* the block count should be 1 from disk_del_events() */
2001 WARN_ON_ONCE(disk
->ev
&& disk
->ev
->block
!= 1);