1 // SPDX-License-Identifier: GPL-2.0
5 * Portions Copyright (C) 2020 Christoph Hellwig
8 #include <linux/module.h>
9 #include <linux/ctype.h>
11 #include <linux/genhd.h>
12 #include <linux/kdev_t.h>
13 #include <linux/kernel.h>
14 #include <linux/blkdev.h>
15 #include <linux/backing-dev.h>
16 #include <linux/init.h>
17 #include <linux/spinlock.h>
18 #include <linux/proc_fs.h>
19 #include <linux/seq_file.h>
20 #include <linux/slab.h>
21 #include <linux/kmod.h>
22 #include <linux/mutex.h>
23 #include <linux/idr.h>
24 #include <linux/log2.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/badblocks.h>
30 static struct kobject *block_depr;
32 DECLARE_RWSEM(bdev_lookup_sem);
34 /* for extended dynamic devt allocation, currently only one major is used */
35 #define NR_EXT_DEVT (1 << MINORBITS)
36 static DEFINE_IDA(ext_devt_ida);
38 static void disk_check_events(struct disk_events *ev,
39 unsigned int *clearing_ptr);
40 static void disk_alloc_events(struct gendisk *disk);
41 static void disk_add_events(struct gendisk *disk);
42 static void disk_del_events(struct gendisk *disk);
43 static void disk_release_events(struct gendisk *disk);
45 void set_capacity(struct gendisk *disk, sector_t sectors)
47 struct block_device *bdev = disk->part0;
50 spin_lock_irqsave(&bdev->bd_size_lock, flags);
51 i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
52 spin_unlock_irqrestore(&bdev->bd_size_lock, flags);
54 EXPORT_SYMBOL(set_capacity);
57 * Set disk capacity and notify if the size is not currently zero and will not
58 * be set to zero. Returns true if a uevent was sent, otherwise false.
60 bool set_capacity_and_notify(struct gendisk *disk, sector_t size)
62 sector_t capacity = get_capacity(disk);
63 char *envp[] = { "RESIZE=1", NULL };
65 set_capacity(disk, size);
68 * Only print a message and send a uevent if the gendisk is user visible
69 * and alive. This avoids spamming the log and udev when setting the
70 * initial capacity during probing.
72 if (size == capacity ||
73 (disk->flags & (GENHD_FL_UP | GENHD_FL_HIDDEN)) != GENHD_FL_UP)
76 pr_info("%s: detected capacity change from %lld to %lld\n",
77 disk->disk_name, size, capacity);
80 * Historically we did not send a uevent for changes to/from an empty
83 if (!capacity || !size)
85 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
88 EXPORT_SYMBOL_GPL(set_capacity_and_notify);
91 * Format the device name of the indicated disk into the supplied buffer and
92 * return a pointer to that same buffer for convenience.
94 char *disk_name(struct gendisk *hd, int partno, char *buf)
97 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
98 else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
99 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
101 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
106 const char *bdevname(struct block_device *bdev, char *buf)
108 return disk_name(bdev->bd_disk, bdev->bd_partno, buf);
110 EXPORT_SYMBOL(bdevname);
112 static void part_stat_read_all(struct block_device *part,
113 struct disk_stats *stat)
117 memset(stat, 0, sizeof(struct disk_stats));
118 for_each_possible_cpu(cpu) {
119 struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu);
122 for (group = 0; group < NR_STAT_GROUPS; group++) {
123 stat->nsecs[group] += ptr->nsecs[group];
124 stat->sectors[group] += ptr->sectors[group];
125 stat->ios[group] += ptr->ios[group];
126 stat->merges[group] += ptr->merges[group];
129 stat->io_ticks += ptr->io_ticks;
133 static unsigned int part_in_flight(struct block_device *part)
135 unsigned int inflight = 0;
138 for_each_possible_cpu(cpu) {
139 inflight += part_stat_local_read_cpu(part, in_flight[0], cpu) +
140 part_stat_local_read_cpu(part, in_flight[1], cpu);
142 if ((int)inflight < 0)
148 static void part_in_flight_rw(struct block_device *part,
149 unsigned int inflight[2])
155 for_each_possible_cpu(cpu) {
156 inflight[0] += part_stat_local_read_cpu(part, in_flight[0], cpu);
157 inflight[1] += part_stat_local_read_cpu(part, in_flight[1], cpu);
159 if ((int)inflight[0] < 0)
161 if ((int)inflight[1] < 0)
165 struct block_device *__disk_get_part(struct gendisk *disk, int partno)
167 struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl);
169 if (unlikely(partno < 0 || partno >= ptbl->len))
171 return rcu_dereference(ptbl->part[partno]);
175 * disk_part_iter_init - initialize partition iterator
176 * @piter: iterator to initialize
177 * @disk: disk to iterate over
178 * @flags: DISK_PITER_* flags
180 * Initialize @piter so that it iterates over partitions of @disk.
185 void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
188 struct disk_part_tbl *ptbl;
191 ptbl = rcu_dereference(disk->part_tbl);
196 if (flags & DISK_PITER_REVERSE)
197 piter->idx = ptbl->len - 1;
198 else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
203 piter->flags = flags;
207 EXPORT_SYMBOL_GPL(disk_part_iter_init);
210 * disk_part_iter_next - proceed iterator to the next partition and return it
211 * @piter: iterator of interest
213 * Proceed @piter to the next partition and return it.
218 struct block_device *disk_part_iter_next(struct disk_part_iter *piter)
220 struct disk_part_tbl *ptbl;
223 /* put the last partition */
224 disk_part_iter_exit(piter);
228 ptbl = rcu_dereference(piter->disk->part_tbl);
230 /* determine iteration parameters */
231 if (piter->flags & DISK_PITER_REVERSE) {
233 if (piter->flags & (DISK_PITER_INCL_PART0 |
234 DISK_PITER_INCL_EMPTY_PART0))
243 /* iterate to the next partition */
244 for (; piter->idx != end; piter->idx += inc) {
245 struct block_device *part;
247 part = rcu_dereference(ptbl->part[piter->idx]);
250 piter->part = bdgrab(part);
253 if (!bdev_nr_sectors(part) &&
254 !(piter->flags & DISK_PITER_INCL_EMPTY) &&
255 !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
270 EXPORT_SYMBOL_GPL(disk_part_iter_next);
273 * disk_part_iter_exit - finish up partition iteration
274 * @piter: iter of interest
276 * Called when iteration is over. Cleans up @piter.
281 void disk_part_iter_exit(struct disk_part_iter *piter)
287 EXPORT_SYMBOL_GPL(disk_part_iter_exit);
289 static inline int sector_in_part(struct block_device *part, sector_t sector)
291 return part->bd_start_sect <= sector &&
292 sector < part->bd_start_sect + bdev_nr_sectors(part);
296 * disk_map_sector_rcu - map sector to partition
297 * @disk: gendisk of interest
298 * @sector: sector to map
300 * Find out which partition @sector maps to on @disk. This is
301 * primarily used for stats accounting.
307 * Found partition on success, part0 is returned if no partition matches
308 * or the matched partition is being deleted.
310 struct block_device *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
312 struct disk_part_tbl *ptbl;
313 struct block_device *part;
317 ptbl = rcu_dereference(disk->part_tbl);
319 part = rcu_dereference(ptbl->last_lookup);
320 if (part && sector_in_part(part, sector))
323 for (i = 1; i < ptbl->len; i++) {
324 part = rcu_dereference(ptbl->part[i]);
325 if (part && sector_in_part(part, sector)) {
326 rcu_assign_pointer(ptbl->last_lookup, part);
338 * disk_has_partitions
339 * @disk: gendisk of interest
341 * Walk through the partition table and check if valid partition exists.
347 * True if the gendisk has at least one valid non-zero size partition.
350 bool disk_has_partitions(struct gendisk *disk)
352 struct disk_part_tbl *ptbl;
357 ptbl = rcu_dereference(disk->part_tbl);
359 /* Iterate partitions skipping the whole device at index 0 */
360 for (i = 1; i < ptbl->len; i++) {
361 if (rcu_dereference(ptbl->part[i])) {
371 EXPORT_SYMBOL_GPL(disk_has_partitions);
374 * Can be deleted altogether. Later.
377 #define BLKDEV_MAJOR_HASH_SIZE 255
378 static struct blk_major_name {
379 struct blk_major_name *next;
382 void (*probe)(dev_t devt);
383 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
384 static DEFINE_MUTEX(major_names_lock);
386 /* index in the above - for now: assume no multimajor ranges */
387 static inline int major_to_index(unsigned major)
389 return major % BLKDEV_MAJOR_HASH_SIZE;
392 #ifdef CONFIG_PROC_FS
393 void blkdev_show(struct seq_file *seqf, off_t offset)
395 struct blk_major_name *dp;
397 mutex_lock(&major_names_lock);
398 for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next)
399 if (dp->major == offset)
400 seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
401 mutex_unlock(&major_names_lock);
403 #endif /* CONFIG_PROC_FS */
406 * __register_blkdev - register a new block device
408 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
409 * @major = 0, try to allocate any unused major number.
410 * @name: the name of the new block device as a zero terminated string
411 * @probe: allback that is called on access to any minor number of @major
413 * The @name must be unique within the system.
415 * The return value depends on the @major input parameter:
417 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
418 * then the function returns zero on success, or a negative error code
419 * - if any unused major number was requested with @major = 0 parameter
420 * then the return value is the allocated major number in range
421 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
423 * See Documentation/admin-guide/devices.txt for the list of allocated
426 * Use register_blkdev instead for any new code.
428 int __register_blkdev(unsigned int major, const char *name,
429 void (*probe)(dev_t devt))
431 struct blk_major_name **n, *p;
434 mutex_lock(&major_names_lock);
438 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
439 if (major_names[index] == NULL)
444 printk("%s: failed to get major for %s\n",
453 if (major >= BLKDEV_MAJOR_MAX) {
454 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
455 __func__, major, BLKDEV_MAJOR_MAX-1, name);
461 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
469 strlcpy(p->name, name, sizeof(p->name));
471 index = major_to_index(major);
473 for (n = &major_names[index]; *n; n = &(*n)->next) {
474 if ((*n)->major == major)
483 printk("register_blkdev: cannot get major %u for %s\n",
488 mutex_unlock(&major_names_lock);
491 EXPORT_SYMBOL(__register_blkdev);
493 void unregister_blkdev(unsigned int major, const char *name)
495 struct blk_major_name **n;
496 struct blk_major_name *p = NULL;
497 int index = major_to_index(major);
499 mutex_lock(&major_names_lock);
500 for (n = &major_names[index]; *n; n = &(*n)->next)
501 if ((*n)->major == major)
503 if (!*n || strcmp((*n)->name, name)) {
509 mutex_unlock(&major_names_lock);
513 EXPORT_SYMBOL(unregister_blkdev);
516 * blk_mangle_minor - scatter minor numbers apart
517 * @minor: minor number to mangle
519 * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
520 * is enabled. Mangling twice gives the original value.
528 static int blk_mangle_minor(int minor)
530 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
533 for (i = 0; i < MINORBITS / 2; i++) {
534 int low = minor & (1 << i);
535 int high = minor & (1 << (MINORBITS - 1 - i));
536 int distance = MINORBITS - 1 - 2 * i;
538 minor ^= low | high; /* clear both bits */
539 low <<= distance; /* swap the positions */
541 minor |= low | high; /* and set */
548 * blk_alloc_devt - allocate a dev_t for a block device
549 * @bdev: block device to allocate dev_t for
550 * @devt: out parameter for resulting dev_t
552 * Allocate a dev_t for block device.
555 * 0 on success, allocated dev_t is returned in *@devt. -errno on
561 int blk_alloc_devt(struct block_device *bdev, dev_t *devt)
563 struct gendisk *disk = bdev->bd_disk;
566 /* in consecutive minor range? */
567 if (bdev->bd_partno < disk->minors) {
568 *devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
572 idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT, GFP_KERNEL);
574 return idx == -ENOSPC ? -EBUSY : idx;
576 *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
581 * blk_free_devt - free a dev_t
582 * @devt: dev_t to free
584 * Free @devt which was allocated using blk_alloc_devt().
589 void blk_free_devt(dev_t devt)
591 if (MAJOR(devt) == BLOCK_EXT_MAJOR)
592 ida_free(&ext_devt_ida, blk_mangle_minor(MINOR(devt)));
595 static char *bdevt_str(dev_t devt, char *buf)
597 if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
598 char tbuf[BDEVT_SIZE];
599 snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
600 snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
602 snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
607 static void disk_scan_partitions(struct gendisk *disk)
609 struct block_device *bdev;
611 if (!get_capacity(disk) || !disk_part_scan_enabled(disk))
614 set_bit(GD_NEED_PART_SCAN, &disk->state);
615 bdev = blkdev_get_by_dev(disk_devt(disk), FMODE_READ, NULL);
617 blkdev_put(bdev, FMODE_READ);
620 static void register_disk(struct device *parent, struct gendisk *disk,
621 const struct attribute_group **groups)
623 struct device *ddev = disk_to_dev(disk);
624 struct disk_part_iter piter;
625 struct block_device *part;
628 ddev->parent = parent;
630 dev_set_name(ddev, "%s", disk->disk_name);
632 /* delay uevents, until we scanned partition table */
633 dev_set_uevent_suppress(ddev, 1);
636 WARN_ON(ddev->groups);
637 ddev->groups = groups;
639 if (device_add(ddev))
641 if (!sysfs_deprecated) {
642 err = sysfs_create_link(block_depr, &ddev->kobj,
643 kobject_name(&ddev->kobj));
651 * avoid probable deadlock caused by allocating memory with
652 * GFP_KERNEL in runtime_resume callback of its all ancestor
655 pm_runtime_set_memalloc_noio(ddev, true);
657 disk->part0->bd_holder_dir =
658 kobject_create_and_add("holders", &ddev->kobj);
659 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
661 if (disk->flags & GENHD_FL_HIDDEN) {
662 dev_set_uevent_suppress(ddev, 0);
666 disk_scan_partitions(disk);
668 /* announce disk after possible partitions are created */
669 dev_set_uevent_suppress(ddev, 0);
670 kobject_uevent(&ddev->kobj, KOBJ_ADD);
672 /* announce possible partitions */
673 disk_part_iter_init(&piter, disk, 0);
674 while ((part = disk_part_iter_next(&piter)))
675 kobject_uevent(bdev_kobj(part), KOBJ_ADD);
676 disk_part_iter_exit(&piter);
678 if (disk->queue->backing_dev_info->dev) {
679 err = sysfs_create_link(&ddev->kobj,
680 &disk->queue->backing_dev_info->dev->kobj,
687 * __device_add_disk - add disk information to kernel list
688 * @parent: parent device for the disk
689 * @disk: per-device partitioning information
690 * @groups: Additional per-device sysfs groups
691 * @register_queue: register the queue if set to true
693 * This function registers the partitioning information in @disk
696 * FIXME: error handling
698 static void __device_add_disk(struct device *parent, struct gendisk *disk,
699 const struct attribute_group **groups,
706 * The disk queue should now be all set with enough information about
707 * the device for the elevator code to pick an adequate default
708 * elevator if one is needed, that is, for devices requesting queue
712 elevator_init_mq(disk->queue);
714 /* minors == 0 indicates to use ext devt from part0 and should
715 * be accompanied with EXT_DEVT flag. Make sure all
716 * parameters make sense.
718 WARN_ON(disk->minors && !(disk->major || disk->first_minor));
719 WARN_ON(!disk->minors &&
720 !(disk->flags & (GENHD_FL_EXT_DEVT | GENHD_FL_HIDDEN)));
722 disk->flags |= GENHD_FL_UP;
724 retval = blk_alloc_devt(disk->part0, &devt);
729 disk->major = MAJOR(devt);
730 disk->first_minor = MINOR(devt);
732 disk_alloc_events(disk);
734 if (disk->flags & GENHD_FL_HIDDEN) {
736 * Don't let hidden disks show up in /proc/partitions,
737 * and don't bother scanning for partitions either.
739 disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
740 disk->flags |= GENHD_FL_NO_PART_SCAN;
742 struct backing_dev_info *bdi = disk->queue->backing_dev_info;
743 struct device *dev = disk_to_dev(disk);
746 /* Register BDI before referencing it from bdev */
748 ret = bdi_register(bdi, "%u:%u", MAJOR(devt), MINOR(devt));
750 bdi_set_owner(bdi, dev);
751 bdev_add(disk->part0, devt);
753 register_disk(parent, disk, groups);
755 blk_register_queue(disk);
758 * Take an extra ref on queue which will be put on disk_release()
759 * so that it sticks around as long as @disk is there.
761 WARN_ON_ONCE(!blk_get_queue(disk->queue));
763 disk_add_events(disk);
764 blk_integrity_add(disk);
767 void device_add_disk(struct device *parent, struct gendisk *disk,
768 const struct attribute_group **groups)
771 __device_add_disk(parent, disk, groups, true);
773 EXPORT_SYMBOL(device_add_disk);
775 void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk)
777 __device_add_disk(parent, disk, NULL, false);
779 EXPORT_SYMBOL(device_add_disk_no_queue_reg);
781 static void invalidate_partition(struct block_device *bdev)
784 __invalidate_device(bdev, true);
787 * Unhash the bdev inode for this device so that it can't be looked
788 * up any more even if openers still hold references to it.
790 remove_inode_hash(bdev->bd_inode);
794 * del_gendisk - remove the gendisk
795 * @disk: the struct gendisk to remove
797 * Removes the gendisk and all its associated resources. This deletes the
798 * partitions associated with the gendisk, and unregisters the associated
801 * This is the counter to the respective __device_add_disk() call.
803 * The final removal of the struct gendisk happens when its refcount reaches 0
804 * with put_disk(), which should be called after del_gendisk(), if
805 * __device_add_disk() was used.
807 * Drivers exist which depend on the release of the gendisk to be synchronous,
808 * it should not be deferred.
812 void del_gendisk(struct gendisk *disk)
814 struct disk_part_iter piter;
815 struct block_device *part;
819 if (WARN_ON_ONCE(!disk->queue))
822 blk_integrity_del(disk);
823 disk_del_events(disk);
826 * Block lookups of the disk until all bdevs are unhashed and the
827 * disk is marked as dead (GENHD_FL_UP cleared).
829 down_write(&bdev_lookup_sem);
831 /* invalidate stuff */
832 disk_part_iter_init(&piter, disk,
833 DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
834 while ((part = disk_part_iter_next(&piter))) {
835 invalidate_partition(part);
836 delete_partition(part);
838 disk_part_iter_exit(&piter);
840 invalidate_partition(disk->part0);
841 set_capacity(disk, 0);
842 disk->flags &= ~GENHD_FL_UP;
843 up_write(&bdev_lookup_sem);
845 if (!(disk->flags & GENHD_FL_HIDDEN)) {
846 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
849 * Unregister bdi before releasing device numbers (as they can
850 * get reused and we'd get clashes in sysfs).
852 bdi_unregister(disk->queue->backing_dev_info);
855 blk_unregister_queue(disk);
857 kobject_put(disk->part0->bd_holder_dir);
858 kobject_put(disk->slave_dir);
860 part_stat_set_all(disk->part0, 0);
861 disk->part0->bd_stamp = 0;
862 if (!sysfs_deprecated)
863 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
864 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
865 device_del(disk_to_dev(disk));
867 EXPORT_SYMBOL(del_gendisk);
869 /* sysfs access to bad-blocks list. */
870 static ssize_t disk_badblocks_show(struct device *dev,
871 struct device_attribute *attr,
874 struct gendisk *disk = dev_to_disk(dev);
877 return sprintf(page, "\n");
879 return badblocks_show(disk->bb, page, 0);
882 static ssize_t disk_badblocks_store(struct device *dev,
883 struct device_attribute *attr,
884 const char *page, size_t len)
886 struct gendisk *disk = dev_to_disk(dev);
891 return badblocks_store(disk->bb, page, len, 0);
894 void blk_request_module(dev_t devt)
896 unsigned int major = MAJOR(devt);
897 struct blk_major_name **n;
899 mutex_lock(&major_names_lock);
900 for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) {
901 if ((*n)->major == major && (*n)->probe) {
903 mutex_unlock(&major_names_lock);
907 mutex_unlock(&major_names_lock);
909 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
910 /* Make old-style 2.4 aliases work */
911 request_module("block-major-%d", MAJOR(devt));
915 * bdget_disk - do bdget() by gendisk and partition number
916 * @disk: gendisk of interest
917 * @partno: partition number
919 * Find partition @partno from @disk, do bdget() on it.
925 * Resulting block_device on success, NULL on failure.
927 struct block_device *bdget_disk(struct gendisk *disk, int partno)
929 struct block_device *bdev = NULL;
932 bdev = __disk_get_part(disk, partno);
933 if (bdev && !bdgrab(bdev))
941 * print a full list of all partitions - intended for places where the root
942 * filesystem can't be mounted and thus to give the victim some idea of what
945 void __init printk_all_partitions(void)
947 struct class_dev_iter iter;
950 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
951 while ((dev = class_dev_iter_next(&iter))) {
952 struct gendisk *disk = dev_to_disk(dev);
953 struct disk_part_iter piter;
954 struct block_device *part;
955 char name_buf[BDEVNAME_SIZE];
956 char devt_buf[BDEVT_SIZE];
959 * Don't show empty devices or things that have been
962 if (get_capacity(disk) == 0 ||
963 (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
967 * Note, unlike /proc/partitions, I am showing the
968 * numbers in hex - the same format as the root=
971 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
972 while ((part = disk_part_iter_next(&piter))) {
973 bool is_part0 = part == disk->part0;
975 printk("%s%s %10llu %s %s", is_part0 ? "" : " ",
976 bdevt_str(part->bd_dev, devt_buf),
977 bdev_nr_sectors(part) >> 1,
978 disk_name(disk, part->bd_partno, name_buf),
980 part->bd_meta_info->uuid : "");
982 if (dev->parent && dev->parent->driver)
983 printk(" driver: %s\n",
984 dev->parent->driver->name);
986 printk(" (driver?)\n");
990 disk_part_iter_exit(&piter);
992 class_dev_iter_exit(&iter);
995 #ifdef CONFIG_PROC_FS
997 static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
1000 struct class_dev_iter *iter;
1003 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
1005 return ERR_PTR(-ENOMEM);
1007 seqf->private = iter;
1008 class_dev_iter_init(iter, &block_class, NULL, &disk_type);
1010 dev = class_dev_iter_next(iter);
1015 return dev_to_disk(dev);
1018 static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
1023 dev = class_dev_iter_next(seqf->private);
1025 return dev_to_disk(dev);
1030 static void disk_seqf_stop(struct seq_file *seqf, void *v)
1032 struct class_dev_iter *iter = seqf->private;
1034 /* stop is called even after start failed :-( */
1036 class_dev_iter_exit(iter);
1038 seqf->private = NULL;
1042 static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
1046 p = disk_seqf_start(seqf, pos);
1047 if (!IS_ERR_OR_NULL(p) && !*pos)
1048 seq_puts(seqf, "major minor #blocks name\n\n");
1052 static int show_partition(struct seq_file *seqf, void *v)
1054 struct gendisk *sgp = v;
1055 struct disk_part_iter piter;
1056 struct block_device *part;
1057 char buf[BDEVNAME_SIZE];
1059 /* Don't show non-partitionable removeable devices or empty devices */
1060 if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
1061 (sgp->flags & GENHD_FL_REMOVABLE)))
1063 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
1066 /* show the full disk and all non-0 size partitions of it */
1067 disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
1068 while ((part = disk_part_iter_next(&piter)))
1069 seq_printf(seqf, "%4d %7d %10llu %s\n",
1070 MAJOR(part->bd_dev), MINOR(part->bd_dev),
1071 bdev_nr_sectors(part) >> 1,
1072 disk_name(sgp, part->bd_partno, buf));
1073 disk_part_iter_exit(&piter);
1078 static const struct seq_operations partitions_op = {
1079 .start = show_partition_start,
1080 .next = disk_seqf_next,
1081 .stop = disk_seqf_stop,
1082 .show = show_partition
1086 static int __init genhd_device_init(void)
1090 block_class.dev_kobj = sysfs_dev_block_kobj;
1091 error = class_register(&block_class);
1092 if (unlikely(error))
1096 register_blkdev(BLOCK_EXT_MAJOR, "blkext");
1098 /* create top-level block dir */
1099 if (!sysfs_deprecated)
1100 block_depr = kobject_create_and_add("block", NULL);
1104 subsys_initcall(genhd_device_init);
1106 static ssize_t disk_range_show(struct device *dev,
1107 struct device_attribute *attr, char *buf)
1109 struct gendisk *disk = dev_to_disk(dev);
1111 return sprintf(buf, "%d\n", disk->minors);
1114 static ssize_t disk_ext_range_show(struct device *dev,
1115 struct device_attribute *attr, char *buf)
1117 struct gendisk *disk = dev_to_disk(dev);
1119 return sprintf(buf, "%d\n", disk_max_parts(disk));
1122 static ssize_t disk_removable_show(struct device *dev,
1123 struct device_attribute *attr, char *buf)
1125 struct gendisk *disk = dev_to_disk(dev);
1127 return sprintf(buf, "%d\n",
1128 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
1131 static ssize_t disk_hidden_show(struct device *dev,
1132 struct device_attribute *attr, char *buf)
1134 struct gendisk *disk = dev_to_disk(dev);
1136 return sprintf(buf, "%d\n",
1137 (disk->flags & GENHD_FL_HIDDEN ? 1 : 0));
1140 static ssize_t disk_ro_show(struct device *dev,
1141 struct device_attribute *attr, char *buf)
1143 struct gendisk *disk = dev_to_disk(dev);
1145 return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
1148 ssize_t part_size_show(struct device *dev,
1149 struct device_attribute *attr, char *buf)
1151 return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));
1154 ssize_t part_stat_show(struct device *dev,
1155 struct device_attribute *attr, char *buf)
1157 struct block_device *bdev = dev_to_bdev(dev);
1158 struct request_queue *q = bdev->bd_disk->queue;
1159 struct disk_stats stat;
1160 unsigned int inflight;
1162 part_stat_read_all(bdev, &stat);
1164 inflight = blk_mq_in_flight(q, bdev);
1166 inflight = part_in_flight(bdev);
1169 "%8lu %8lu %8llu %8u "
1170 "%8lu %8lu %8llu %8u "
1172 "%8lu %8lu %8llu %8u "
1175 stat.ios[STAT_READ],
1176 stat.merges[STAT_READ],
1177 (unsigned long long)stat.sectors[STAT_READ],
1178 (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC),
1179 stat.ios[STAT_WRITE],
1180 stat.merges[STAT_WRITE],
1181 (unsigned long long)stat.sectors[STAT_WRITE],
1182 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC),
1184 jiffies_to_msecs(stat.io_ticks),
1185 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1186 stat.nsecs[STAT_WRITE] +
1187 stat.nsecs[STAT_DISCARD] +
1188 stat.nsecs[STAT_FLUSH],
1190 stat.ios[STAT_DISCARD],
1191 stat.merges[STAT_DISCARD],
1192 (unsigned long long)stat.sectors[STAT_DISCARD],
1193 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC),
1194 stat.ios[STAT_FLUSH],
1195 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC));
1198 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
1201 struct block_device *bdev = dev_to_bdev(dev);
1202 struct request_queue *q = bdev->bd_disk->queue;
1203 unsigned int inflight[2];
1206 blk_mq_in_flight_rw(q, bdev, inflight);
1208 part_in_flight_rw(bdev, inflight);
1210 return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
1213 static ssize_t disk_capability_show(struct device *dev,
1214 struct device_attribute *attr, char *buf)
1216 struct gendisk *disk = dev_to_disk(dev);
1218 return sprintf(buf, "%x\n", disk->flags);
1221 static ssize_t disk_alignment_offset_show(struct device *dev,
1222 struct device_attribute *attr,
1225 struct gendisk *disk = dev_to_disk(dev);
1227 return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue));
1230 static ssize_t disk_discard_alignment_show(struct device *dev,
1231 struct device_attribute *attr,
1234 struct gendisk *disk = dev_to_disk(dev);
1236 return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
1239 static DEVICE_ATTR(range, 0444, disk_range_show, NULL);
1240 static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL);
1241 static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL);
1242 static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL);
1243 static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL);
1244 static DEVICE_ATTR(size, 0444, part_size_show, NULL);
1245 static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL);
1246 static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL);
1247 static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL);
1248 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
1249 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
1250 static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
1252 #ifdef CONFIG_FAIL_MAKE_REQUEST
1253 ssize_t part_fail_show(struct device *dev,
1254 struct device_attribute *attr, char *buf)
1256 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail);
1259 ssize_t part_fail_store(struct device *dev,
1260 struct device_attribute *attr,
1261 const char *buf, size_t count)
1265 if (count > 0 && sscanf(buf, "%d", &i) > 0)
1266 dev_to_bdev(dev)->bd_make_it_fail = i;
1271 static struct device_attribute dev_attr_fail =
1272 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
1273 #endif /* CONFIG_FAIL_MAKE_REQUEST */
1275 #ifdef CONFIG_FAIL_IO_TIMEOUT
1276 static struct device_attribute dev_attr_fail_timeout =
1277 __ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store);
1280 static struct attribute *disk_attrs[] = {
1281 &dev_attr_range.attr,
1282 &dev_attr_ext_range.attr,
1283 &dev_attr_removable.attr,
1284 &dev_attr_hidden.attr,
1286 &dev_attr_size.attr,
1287 &dev_attr_alignment_offset.attr,
1288 &dev_attr_discard_alignment.attr,
1289 &dev_attr_capability.attr,
1290 &dev_attr_stat.attr,
1291 &dev_attr_inflight.attr,
1292 &dev_attr_badblocks.attr,
1293 #ifdef CONFIG_FAIL_MAKE_REQUEST
1294 &dev_attr_fail.attr,
1296 #ifdef CONFIG_FAIL_IO_TIMEOUT
1297 &dev_attr_fail_timeout.attr,
1302 static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n)
1304 struct device *dev = container_of(kobj, typeof(*dev), kobj);
1305 struct gendisk *disk = dev_to_disk(dev);
1307 if (a == &dev_attr_badblocks.attr && !disk->bb)
1312 static struct attribute_group disk_attr_group = {
1313 .attrs = disk_attrs,
1314 .is_visible = disk_visible,
1317 static const struct attribute_group *disk_attr_groups[] = {
1323 * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
1324 * @disk: disk to replace part_tbl for
1325 * @new_ptbl: new part_tbl to install
1327 * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The
1328 * original ptbl is freed using RCU callback.
1331 * Matching bd_mutex locked or the caller is the only user of @disk.
1333 static void disk_replace_part_tbl(struct gendisk *disk,
1334 struct disk_part_tbl *new_ptbl)
1336 struct disk_part_tbl *old_ptbl =
1337 rcu_dereference_protected(disk->part_tbl, 1);
1339 rcu_assign_pointer(disk->part_tbl, new_ptbl);
1342 rcu_assign_pointer(old_ptbl->last_lookup, NULL);
1343 kfree_rcu(old_ptbl, rcu_head);
1348 * disk_expand_part_tbl - expand disk->part_tbl
1349 * @disk: disk to expand part_tbl for
1350 * @partno: expand such that this partno can fit in
1352 * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl
1353 * uses RCU to allow unlocked dereferencing for stats and other stuff.
1356 * Matching bd_mutex locked or the caller is the only user of @disk.
1360 * 0 on success, -errno on failure.
1362 int disk_expand_part_tbl(struct gendisk *disk, int partno)
1364 struct disk_part_tbl *old_ptbl =
1365 rcu_dereference_protected(disk->part_tbl, 1);
1366 struct disk_part_tbl *new_ptbl;
1367 int len = old_ptbl ? old_ptbl->len : 0;
1371 * check for int overflow, since we can get here from blkpg_ioctl()
1372 * with a user passed 'partno'.
1374 target = partno + 1;
1378 /* disk_max_parts() is zero during initialization, ignore if so */
1379 if (disk_max_parts(disk) && target > disk_max_parts(disk))
1385 new_ptbl = kzalloc_node(struct_size(new_ptbl, part, target), GFP_KERNEL,
1390 new_ptbl->len = target;
1392 for (i = 0; i < len; i++)
1393 rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
1395 disk_replace_part_tbl(disk, new_ptbl);
1400 * disk_release - releases all allocated resources of the gendisk
1401 * @dev: the device representing this disk
1403 * This function releases all allocated resources of the gendisk.
1405 * Drivers which used __device_add_disk() have a gendisk with a request_queue
1406 * assigned. Since the request_queue sits on top of the gendisk for these
1407 * drivers we also call blk_put_queue() for them, and we expect the
1408 * request_queue refcount to reach 0 at this point, and so the request_queue
1409 * will also be freed prior to the disk.
1411 * Context: can sleep
1413 static void disk_release(struct device *dev)
1415 struct gendisk *disk = dev_to_disk(dev);
1419 blk_free_devt(dev->devt);
1420 disk_release_events(disk);
1421 kfree(disk->random);
1422 disk_replace_part_tbl(disk, NULL);
1425 blk_put_queue(disk->queue);
1428 struct class block_class = {
1432 static char *block_devnode(struct device *dev, umode_t *mode,
1433 kuid_t *uid, kgid_t *gid)
1435 struct gendisk *disk = dev_to_disk(dev);
1437 if (disk->fops->devnode)
1438 return disk->fops->devnode(disk, mode);
1442 const struct device_type disk_type = {
1444 .groups = disk_attr_groups,
1445 .release = disk_release,
1446 .devnode = block_devnode,
1449 #ifdef CONFIG_PROC_FS
1451 * aggregate disk stat collector. Uses the same stats that the sysfs
1452 * entries do, above, but makes them available through one seq_file.
1454 * The output looks suspiciously like /proc/partitions with a bunch of
1457 static int diskstats_show(struct seq_file *seqf, void *v)
1459 struct gendisk *gp = v;
1460 struct disk_part_iter piter;
1461 struct block_device *hd;
1462 char buf[BDEVNAME_SIZE];
1463 unsigned int inflight;
1464 struct disk_stats stat;
1467 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1468 seq_puts(seqf, "major minor name"
1469 " rio rmerge rsect ruse wio wmerge "
1470 "wsect wuse running use aveq"
1474 disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
1475 while ((hd = disk_part_iter_next(&piter))) {
1476 part_stat_read_all(hd, &stat);
1477 if (queue_is_mq(gp->queue))
1478 inflight = blk_mq_in_flight(gp->queue, hd);
1480 inflight = part_in_flight(hd);
1482 seq_printf(seqf, "%4d %7d %s "
1489 MAJOR(hd->bd_dev), MINOR(hd->bd_dev),
1490 disk_name(gp, hd->bd_partno, buf),
1491 stat.ios[STAT_READ],
1492 stat.merges[STAT_READ],
1493 stat.sectors[STAT_READ],
1494 (unsigned int)div_u64(stat.nsecs[STAT_READ],
1496 stat.ios[STAT_WRITE],
1497 stat.merges[STAT_WRITE],
1498 stat.sectors[STAT_WRITE],
1499 (unsigned int)div_u64(stat.nsecs[STAT_WRITE],
1502 jiffies_to_msecs(stat.io_ticks),
1503 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1504 stat.nsecs[STAT_WRITE] +
1505 stat.nsecs[STAT_DISCARD] +
1506 stat.nsecs[STAT_FLUSH],
1508 stat.ios[STAT_DISCARD],
1509 stat.merges[STAT_DISCARD],
1510 stat.sectors[STAT_DISCARD],
1511 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD],
1513 stat.ios[STAT_FLUSH],
1514 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH],
1518 disk_part_iter_exit(&piter);
1523 static const struct seq_operations diskstats_op = {
1524 .start = disk_seqf_start,
1525 .next = disk_seqf_next,
1526 .stop = disk_seqf_stop,
1527 .show = diskstats_show
1530 static int __init proc_genhd_init(void)
1532 proc_create_seq("diskstats", 0, NULL, &diskstats_op);
1533 proc_create_seq("partitions", 0, NULL, &partitions_op);
1536 module_init(proc_genhd_init);
1537 #endif /* CONFIG_PROC_FS */
1539 dev_t blk_lookup_devt(const char *name, int partno)
1541 dev_t devt = MKDEV(0, 0);
1542 struct class_dev_iter iter;
1545 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
1546 while ((dev = class_dev_iter_next(&iter))) {
1547 struct gendisk *disk = dev_to_disk(dev);
1548 struct block_device *part;
1550 if (strcmp(dev_name(dev), name))
1553 if (partno < disk->minors) {
1554 /* We need to return the right devno, even
1555 * if the partition doesn't exist yet.
1557 devt = MKDEV(MAJOR(dev->devt),
1558 MINOR(dev->devt) + partno);
1561 part = bdget_disk(disk, partno);
1563 devt = part->bd_dev;
1568 class_dev_iter_exit(&iter);
1572 struct gendisk *__alloc_disk_node(int minors, int node_id)
1574 struct gendisk *disk;
1575 struct disk_part_tbl *ptbl;
1577 if (minors > DISK_MAX_PARTS) {
1579 "block: can't allocate more than %d partitions\n",
1581 minors = DISK_MAX_PARTS;
1584 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
1588 disk->part0 = bdev_alloc(disk, 0);
1592 disk->node_id = node_id;
1593 if (disk_expand_part_tbl(disk, 0))
1596 ptbl = rcu_dereference_protected(disk->part_tbl, 1);
1597 rcu_assign_pointer(ptbl->part[0], disk->part0);
1599 disk->minors = minors;
1600 rand_initialize_disk(disk);
1601 disk_to_dev(disk)->class = &block_class;
1602 disk_to_dev(disk)->type = &disk_type;
1603 device_initialize(disk_to_dev(disk));
1612 EXPORT_SYMBOL(__alloc_disk_node);
1615 * put_disk - decrements the gendisk refcount
1616 * @disk: the struct gendisk to decrement the refcount for
1618 * This decrements the refcount for the struct gendisk. When this reaches 0
1619 * we'll have disk_release() called.
1621 * Context: Any context, but the last reference must not be dropped from
1624 void put_disk(struct gendisk *disk)
1627 put_device(disk_to_dev(disk));
1629 EXPORT_SYMBOL(put_disk);
1631 static void set_disk_ro_uevent(struct gendisk *gd, int ro)
1633 char event[] = "DISK_RO=1";
1634 char *envp[] = { event, NULL };
1638 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
1641 void set_disk_ro(struct gendisk *disk, int flag)
1643 struct disk_part_iter piter;
1644 struct block_device *part;
1646 if (disk->part0->bd_read_only != flag) {
1647 set_disk_ro_uevent(disk, flag);
1648 disk->part0->bd_read_only = flag;
1651 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
1652 while ((part = disk_part_iter_next(&piter)))
1653 part->bd_read_only = flag;
1654 disk_part_iter_exit(&piter);
1657 EXPORT_SYMBOL(set_disk_ro);
1659 int bdev_read_only(struct block_device *bdev)
1663 return bdev->bd_read_only;
1666 EXPORT_SYMBOL(bdev_read_only);
1669 * Disk events - monitor disk events like media change and eject request.
1671 struct disk_events {
1672 struct list_head node; /* all disk_event's */
1673 struct gendisk *disk; /* the associated disk */
1676 struct mutex block_mutex; /* protects blocking */
1677 int block; /* event blocking depth */
1678 unsigned int pending; /* events already sent out */
1679 unsigned int clearing; /* events being cleared */
1681 long poll_msecs; /* interval, -1 for default */
1682 struct delayed_work dwork;
1685 static const char *disk_events_strs[] = {
1686 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
1687 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
1690 static char *disk_uevents[] = {
1691 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
1692 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
1695 /* list of all disk_events */
1696 static DEFINE_MUTEX(disk_events_mutex);
1697 static LIST_HEAD(disk_events);
1699 /* disable in-kernel polling by default */
1700 static unsigned long disk_events_dfl_poll_msecs;
1702 static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
1704 struct disk_events *ev = disk->ev;
1705 long intv_msecs = 0;
1708 * If device-specific poll interval is set, always use it. If
1709 * the default is being used, poll if the POLL flag is set.
1711 if (ev->poll_msecs >= 0)
1712 intv_msecs = ev->poll_msecs;
1713 else if (disk->event_flags & DISK_EVENT_FLAG_POLL)
1714 intv_msecs = disk_events_dfl_poll_msecs;
1716 return msecs_to_jiffies(intv_msecs);
1720 * disk_block_events - block and flush disk event checking
1721 * @disk: disk to block events for
1723 * On return from this function, it is guaranteed that event checking
1724 * isn't in progress and won't happen until unblocked by
1725 * disk_unblock_events(). Events blocking is counted and the actual
1726 * unblocking happens after the matching number of unblocks are done.
1728 * Note that this intentionally does not block event checking from
1729 * disk_clear_events().
1734 void disk_block_events(struct gendisk *disk)
1736 struct disk_events *ev = disk->ev;
1737 unsigned long flags;
1744 * Outer mutex ensures that the first blocker completes canceling
1745 * the event work before further blockers are allowed to finish.
1747 mutex_lock(&ev->block_mutex);
1749 spin_lock_irqsave(&ev->lock, flags);
1750 cancel = !ev->block++;
1751 spin_unlock_irqrestore(&ev->lock, flags);
1754 cancel_delayed_work_sync(&disk->ev->dwork);
1756 mutex_unlock(&ev->block_mutex);
1759 static void __disk_unblock_events(struct gendisk *disk, bool check_now)
1761 struct disk_events *ev = disk->ev;
1763 unsigned long flags;
1765 spin_lock_irqsave(&ev->lock, flags);
1767 if (WARN_ON_ONCE(ev->block <= 0))
1773 intv = disk_events_poll_jiffies(disk);
1775 queue_delayed_work(system_freezable_power_efficient_wq,
1778 queue_delayed_work(system_freezable_power_efficient_wq,
1781 spin_unlock_irqrestore(&ev->lock, flags);
1785 * disk_unblock_events - unblock disk event checking
1786 * @disk: disk to unblock events for
1788 * Undo disk_block_events(). When the block count reaches zero, it
1789 * starts events polling if configured.
1792 * Don't care. Safe to call from irq context.
1794 void disk_unblock_events(struct gendisk *disk)
1797 __disk_unblock_events(disk, false);
1801 * disk_flush_events - schedule immediate event checking and flushing
1802 * @disk: disk to check and flush events for
1803 * @mask: events to flush
1805 * Schedule immediate event checking on @disk if not blocked. Events in
1806 * @mask are scheduled to be cleared from the driver. Note that this
1807 * doesn't clear the events from @disk->ev.
1810 * If @mask is non-zero must be called with bdev->bd_mutex held.
1812 void disk_flush_events(struct gendisk *disk, unsigned int mask)
1814 struct disk_events *ev = disk->ev;
1819 spin_lock_irq(&ev->lock);
1820 ev->clearing |= mask;
1822 mod_delayed_work(system_freezable_power_efficient_wq,
1824 spin_unlock_irq(&ev->lock);
1828 * disk_clear_events - synchronously check, clear and return pending events
1829 * @disk: disk to fetch and clear events from
1830 * @mask: mask of events to be fetched and cleared
1832 * Disk events are synchronously checked and pending events in @mask
1833 * are cleared and returned. This ignores the block count.
1838 static unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
1840 struct disk_events *ev = disk->ev;
1841 unsigned int pending;
1842 unsigned int clearing = mask;
1847 disk_block_events(disk);
1850 * store the union of mask and ev->clearing on the stack so that the
1851 * race with disk_flush_events does not cause ambiguity (ev->clearing
1852 * can still be modified even if events are blocked).
1854 spin_lock_irq(&ev->lock);
1855 clearing |= ev->clearing;
1857 spin_unlock_irq(&ev->lock);
1859 disk_check_events(ev, &clearing);
1861 * if ev->clearing is not 0, the disk_flush_events got called in the
1862 * middle of this function, so we want to run the workfn without delay.
1864 __disk_unblock_events(disk, ev->clearing ? true : false);
1866 /* then, fetch and clear pending events */
1867 spin_lock_irq(&ev->lock);
1868 pending = ev->pending & mask;
1869 ev->pending &= ~mask;
1870 spin_unlock_irq(&ev->lock);
1871 WARN_ON_ONCE(clearing & mask);
1877 * bdev_check_media_change - check if a removable media has been changed
1878 * @bdev: block device to check
1880 * Check whether a removable media has been changed, and attempt to free all
1881 * dentries and inodes and invalidates all block device page cache entries in
1884 * Returns %true if the block device changed, or %false if not.
1886 bool bdev_check_media_change(struct block_device *bdev)
1888 unsigned int events;
1890 events = disk_clear_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE |
1891 DISK_EVENT_EJECT_REQUEST);
1892 if (!(events & DISK_EVENT_MEDIA_CHANGE))
1895 if (__invalidate_device(bdev, true))
1896 pr_warn("VFS: busy inodes on changed media %s\n",
1897 bdev->bd_disk->disk_name);
1898 set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
1901 EXPORT_SYMBOL(bdev_check_media_change);
1904 * Separate this part out so that a different pointer for clearing_ptr can be
1905 * passed in for disk_clear_events.
1907 static void disk_events_workfn(struct work_struct *work)
1909 struct delayed_work *dwork = to_delayed_work(work);
1910 struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
1912 disk_check_events(ev, &ev->clearing);
1915 static void disk_check_events(struct disk_events *ev,
1916 unsigned int *clearing_ptr)
1918 struct gendisk *disk = ev->disk;
1919 char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
1920 unsigned int clearing = *clearing_ptr;
1921 unsigned int events;
1923 int nr_events = 0, i;
1926 events = disk->fops->check_events(disk, clearing);
1928 /* accumulate pending events and schedule next poll if necessary */
1929 spin_lock_irq(&ev->lock);
1931 events &= ~ev->pending;
1932 ev->pending |= events;
1933 *clearing_ptr &= ~clearing;
1935 intv = disk_events_poll_jiffies(disk);
1936 if (!ev->block && intv)
1937 queue_delayed_work(system_freezable_power_efficient_wq,
1940 spin_unlock_irq(&ev->lock);
1943 * Tell userland about new events. Only the events listed in
1944 * @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT
1945 * is set. Otherwise, events are processed internally but never
1946 * get reported to userland.
1948 for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
1949 if ((events & disk->events & (1 << i)) &&
1950 (disk->event_flags & DISK_EVENT_FLAG_UEVENT))
1951 envp[nr_events++] = disk_uevents[i];
1954 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
1958 * A disk events enabled device has the following sysfs nodes under
1959 * its /sys/block/X/ directory.
1961 * events : list of all supported events
1962 * events_async : list of events which can be detected w/o polling
1963 * (always empty, only for backwards compatibility)
1964 * events_poll_msecs : polling interval, 0: disable, -1: system default
1966 static ssize_t __disk_events_show(unsigned int events, char *buf)
1968 const char *delim = "";
1972 for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
1973 if (events & (1 << i)) {
1974 pos += sprintf(buf + pos, "%s%s",
1975 delim, disk_events_strs[i]);
1979 pos += sprintf(buf + pos, "\n");
1983 static ssize_t disk_events_show(struct device *dev,
1984 struct device_attribute *attr, char *buf)
1986 struct gendisk *disk = dev_to_disk(dev);
1988 if (!(disk->event_flags & DISK_EVENT_FLAG_UEVENT))
1991 return __disk_events_show(disk->events, buf);
1994 static ssize_t disk_events_async_show(struct device *dev,
1995 struct device_attribute *attr, char *buf)
2000 static ssize_t disk_events_poll_msecs_show(struct device *dev,
2001 struct device_attribute *attr,
2004 struct gendisk *disk = dev_to_disk(dev);
2007 return sprintf(buf, "-1\n");
2009 return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
2012 static ssize_t disk_events_poll_msecs_store(struct device *dev,
2013 struct device_attribute *attr,
2014 const char *buf, size_t count)
2016 struct gendisk *disk = dev_to_disk(dev);
2019 if (!count || !sscanf(buf, "%ld", &intv))
2022 if (intv < 0 && intv != -1)
2028 disk_block_events(disk);
2029 disk->ev->poll_msecs = intv;
2030 __disk_unblock_events(disk, true);
2035 static const DEVICE_ATTR(events, 0444, disk_events_show, NULL);
2036 static const DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL);
2037 static const DEVICE_ATTR(events_poll_msecs, 0644,
2038 disk_events_poll_msecs_show,
2039 disk_events_poll_msecs_store);
2041 static const struct attribute *disk_events_attrs[] = {
2042 &dev_attr_events.attr,
2043 &dev_attr_events_async.attr,
2044 &dev_attr_events_poll_msecs.attr,
2049 * The default polling interval can be specified by the kernel
2050 * parameter block.events_dfl_poll_msecs which defaults to 0
2051 * (disable). This can also be modified runtime by writing to
2052 * /sys/module/block/parameters/events_dfl_poll_msecs.
2054 static int disk_events_set_dfl_poll_msecs(const char *val,
2055 const struct kernel_param *kp)
2057 struct disk_events *ev;
2060 ret = param_set_ulong(val, kp);
2064 mutex_lock(&disk_events_mutex);
2066 list_for_each_entry(ev, &disk_events, node)
2067 disk_flush_events(ev->disk, 0);
2069 mutex_unlock(&disk_events_mutex);
2074 static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
2075 .set = disk_events_set_dfl_poll_msecs,
2076 .get = param_get_ulong,
2079 #undef MODULE_PARAM_PREFIX
2080 #define MODULE_PARAM_PREFIX "block."
2082 module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
2083 &disk_events_dfl_poll_msecs, 0644);
2086 * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
2088 static void disk_alloc_events(struct gendisk *disk)
2090 struct disk_events *ev;
2092 if (!disk->fops->check_events || !disk->events)
2095 ev = kzalloc(sizeof(*ev), GFP_KERNEL);
2097 pr_warn("%s: failed to initialize events\n", disk->disk_name);
2101 INIT_LIST_HEAD(&ev->node);
2103 spin_lock_init(&ev->lock);
2104 mutex_init(&ev->block_mutex);
2106 ev->poll_msecs = -1;
2107 INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
2112 static void disk_add_events(struct gendisk *disk)
2114 /* FIXME: error handling */
2115 if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
2116 pr_warn("%s: failed to create sysfs files for events\n",
2122 mutex_lock(&disk_events_mutex);
2123 list_add_tail(&disk->ev->node, &disk_events);
2124 mutex_unlock(&disk_events_mutex);
2127 * Block count is initialized to 1 and the following initial
2128 * unblock kicks it into action.
2130 __disk_unblock_events(disk, true);
2133 static void disk_del_events(struct gendisk *disk)
2136 disk_block_events(disk);
2138 mutex_lock(&disk_events_mutex);
2139 list_del_init(&disk->ev->node);
2140 mutex_unlock(&disk_events_mutex);
2143 sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
2146 static void disk_release_events(struct gendisk *disk)
2148 /* the block count should be 1 from disk_del_events() */
2149 WARN_ON_ONCE(disk->ev && disk->ev->block != 1);