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;
49 spin_lock(&bdev->bd_size_lock);
50 i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
51 spin_unlock(&bdev->bd_size_lock);
53 EXPORT_SYMBOL(set_capacity);
56 * Set disk capacity and notify if the size is not currently zero and will not
57 * be set to zero. Returns true if a uevent was sent, otherwise false.
59 bool set_capacity_and_notify(struct gendisk *disk, sector_t size)
61 sector_t capacity = get_capacity(disk);
62 char *envp[] = { "RESIZE=1", NULL };
64 set_capacity(disk, size);
67 * Only print a message and send a uevent if the gendisk is user visible
68 * and alive. This avoids spamming the log and udev when setting the
69 * initial capacity during probing.
71 if (size == capacity ||
72 (disk->flags & (GENHD_FL_UP | GENHD_FL_HIDDEN)) != GENHD_FL_UP)
75 pr_info("%s: detected capacity change from %lld to %lld\n",
76 disk->disk_name, size, capacity);
79 * Historically we did not send a uevent for changes to/from an empty
82 if (!capacity || !size)
84 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
87 EXPORT_SYMBOL_GPL(set_capacity_and_notify);
90 * Format the device name of the indicated disk into the supplied buffer and
91 * return a pointer to that same buffer for convenience.
93 char *disk_name(struct gendisk *hd, int partno, char *buf)
96 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
97 else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
98 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
100 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
105 const char *bdevname(struct block_device *bdev, char *buf)
107 return disk_name(bdev->bd_disk, bdev->bd_partno, buf);
109 EXPORT_SYMBOL(bdevname);
111 static void part_stat_read_all(struct block_device *part,
112 struct disk_stats *stat)
116 memset(stat, 0, sizeof(struct disk_stats));
117 for_each_possible_cpu(cpu) {
118 struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu);
121 for (group = 0; group < NR_STAT_GROUPS; group++) {
122 stat->nsecs[group] += ptr->nsecs[group];
123 stat->sectors[group] += ptr->sectors[group];
124 stat->ios[group] += ptr->ios[group];
125 stat->merges[group] += ptr->merges[group];
128 stat->io_ticks += ptr->io_ticks;
132 static unsigned int part_in_flight(struct block_device *part)
134 unsigned int inflight = 0;
137 for_each_possible_cpu(cpu) {
138 inflight += part_stat_local_read_cpu(part, in_flight[0], cpu) +
139 part_stat_local_read_cpu(part, in_flight[1], cpu);
141 if ((int)inflight < 0)
147 static void part_in_flight_rw(struct block_device *part,
148 unsigned int inflight[2])
154 for_each_possible_cpu(cpu) {
155 inflight[0] += part_stat_local_read_cpu(part, in_flight[0], cpu);
156 inflight[1] += part_stat_local_read_cpu(part, in_flight[1], cpu);
158 if ((int)inflight[0] < 0)
160 if ((int)inflight[1] < 0)
164 struct block_device *__disk_get_part(struct gendisk *disk, int partno)
166 struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl);
168 if (unlikely(partno < 0 || partno >= ptbl->len))
170 return rcu_dereference(ptbl->part[partno]);
174 * disk_part_iter_init - initialize partition iterator
175 * @piter: iterator to initialize
176 * @disk: disk to iterate over
177 * @flags: DISK_PITER_* flags
179 * Initialize @piter so that it iterates over partitions of @disk.
184 void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
187 struct disk_part_tbl *ptbl;
190 ptbl = rcu_dereference(disk->part_tbl);
195 if (flags & DISK_PITER_REVERSE)
196 piter->idx = ptbl->len - 1;
197 else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
202 piter->flags = flags;
206 EXPORT_SYMBOL_GPL(disk_part_iter_init);
209 * disk_part_iter_next - proceed iterator to the next partition and return it
210 * @piter: iterator of interest
212 * Proceed @piter to the next partition and return it.
217 struct block_device *disk_part_iter_next(struct disk_part_iter *piter)
219 struct disk_part_tbl *ptbl;
222 /* put the last partition */
223 disk_part_iter_exit(piter);
227 ptbl = rcu_dereference(piter->disk->part_tbl);
229 /* determine iteration parameters */
230 if (piter->flags & DISK_PITER_REVERSE) {
232 if (piter->flags & (DISK_PITER_INCL_PART0 |
233 DISK_PITER_INCL_EMPTY_PART0))
242 /* iterate to the next partition */
243 for (; piter->idx != end; piter->idx += inc) {
244 struct block_device *part;
246 part = rcu_dereference(ptbl->part[piter->idx]);
249 piter->part = bdgrab(part);
252 if (!bdev_nr_sectors(part) &&
253 !(piter->flags & DISK_PITER_INCL_EMPTY) &&
254 !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
269 EXPORT_SYMBOL_GPL(disk_part_iter_next);
272 * disk_part_iter_exit - finish up partition iteration
273 * @piter: iter of interest
275 * Called when iteration is over. Cleans up @piter.
280 void disk_part_iter_exit(struct disk_part_iter *piter)
286 EXPORT_SYMBOL_GPL(disk_part_iter_exit);
288 static inline int sector_in_part(struct block_device *part, sector_t sector)
290 return part->bd_start_sect <= sector &&
291 sector < part->bd_start_sect + bdev_nr_sectors(part);
295 * disk_map_sector_rcu - map sector to partition
296 * @disk: gendisk of interest
297 * @sector: sector to map
299 * Find out which partition @sector maps to on @disk. This is
300 * primarily used for stats accounting.
306 * Found partition on success, part0 is returned if no partition matches
307 * or the matched partition is being deleted.
309 struct block_device *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
311 struct disk_part_tbl *ptbl;
312 struct block_device *part;
316 ptbl = rcu_dereference(disk->part_tbl);
318 part = rcu_dereference(ptbl->last_lookup);
319 if (part && sector_in_part(part, sector))
322 for (i = 1; i < ptbl->len; i++) {
323 part = rcu_dereference(ptbl->part[i]);
324 if (part && sector_in_part(part, sector)) {
325 rcu_assign_pointer(ptbl->last_lookup, part);
337 * disk_has_partitions
338 * @disk: gendisk of interest
340 * Walk through the partition table and check if valid partition exists.
346 * True if the gendisk has at least one valid non-zero size partition.
349 bool disk_has_partitions(struct gendisk *disk)
351 struct disk_part_tbl *ptbl;
356 ptbl = rcu_dereference(disk->part_tbl);
358 /* Iterate partitions skipping the whole device at index 0 */
359 for (i = 1; i < ptbl->len; i++) {
360 if (rcu_dereference(ptbl->part[i])) {
370 EXPORT_SYMBOL_GPL(disk_has_partitions);
373 * Can be deleted altogether. Later.
376 #define BLKDEV_MAJOR_HASH_SIZE 255
377 static struct blk_major_name {
378 struct blk_major_name *next;
381 void (*probe)(dev_t devt);
382 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
383 static DEFINE_MUTEX(major_names_lock);
385 /* index in the above - for now: assume no multimajor ranges */
386 static inline int major_to_index(unsigned major)
388 return major % BLKDEV_MAJOR_HASH_SIZE;
391 #ifdef CONFIG_PROC_FS
392 void blkdev_show(struct seq_file *seqf, off_t offset)
394 struct blk_major_name *dp;
396 mutex_lock(&major_names_lock);
397 for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next)
398 if (dp->major == offset)
399 seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
400 mutex_unlock(&major_names_lock);
402 #endif /* CONFIG_PROC_FS */
405 * __register_blkdev - register a new block device
407 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
408 * @major = 0, try to allocate any unused major number.
409 * @name: the name of the new block device as a zero terminated string
410 * @probe: allback that is called on access to any minor number of @major
412 * The @name must be unique within the system.
414 * The return value depends on the @major input parameter:
416 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
417 * then the function returns zero on success, or a negative error code
418 * - if any unused major number was requested with @major = 0 parameter
419 * then the return value is the allocated major number in range
420 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
422 * See Documentation/admin-guide/devices.txt for the list of allocated
425 * Use register_blkdev instead for any new code.
427 int __register_blkdev(unsigned int major, const char *name,
428 void (*probe)(dev_t devt))
430 struct blk_major_name **n, *p;
433 mutex_lock(&major_names_lock);
437 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
438 if (major_names[index] == NULL)
443 printk("%s: failed to get major for %s\n",
452 if (major >= BLKDEV_MAJOR_MAX) {
453 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
454 __func__, major, BLKDEV_MAJOR_MAX-1, name);
460 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
468 strlcpy(p->name, name, sizeof(p->name));
470 index = major_to_index(major);
472 for (n = &major_names[index]; *n; n = &(*n)->next) {
473 if ((*n)->major == major)
482 printk("register_blkdev: cannot get major %u for %s\n",
487 mutex_unlock(&major_names_lock);
490 EXPORT_SYMBOL(__register_blkdev);
492 void unregister_blkdev(unsigned int major, const char *name)
494 struct blk_major_name **n;
495 struct blk_major_name *p = NULL;
496 int index = major_to_index(major);
498 mutex_lock(&major_names_lock);
499 for (n = &major_names[index]; *n; n = &(*n)->next)
500 if ((*n)->major == major)
502 if (!*n || strcmp((*n)->name, name)) {
508 mutex_unlock(&major_names_lock);
512 EXPORT_SYMBOL(unregister_blkdev);
515 * blk_mangle_minor - scatter minor numbers apart
516 * @minor: minor number to mangle
518 * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
519 * is enabled. Mangling twice gives the original value.
527 static int blk_mangle_minor(int minor)
529 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
532 for (i = 0; i < MINORBITS / 2; i++) {
533 int low = minor & (1 << i);
534 int high = minor & (1 << (MINORBITS - 1 - i));
535 int distance = MINORBITS - 1 - 2 * i;
537 minor ^= low | high; /* clear both bits */
538 low <<= distance; /* swap the positions */
540 minor |= low | high; /* and set */
547 * blk_alloc_devt - allocate a dev_t for a block device
548 * @bdev: block device to allocate dev_t for
549 * @devt: out parameter for resulting dev_t
551 * Allocate a dev_t for block device.
554 * 0 on success, allocated dev_t is returned in *@devt. -errno on
560 int blk_alloc_devt(struct block_device *bdev, dev_t *devt)
562 struct gendisk *disk = bdev->bd_disk;
565 /* in consecutive minor range? */
566 if (bdev->bd_partno < disk->minors) {
567 *devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
571 idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT, GFP_KERNEL);
573 return idx == -ENOSPC ? -EBUSY : idx;
575 *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
580 * blk_free_devt - free a dev_t
581 * @devt: dev_t to free
583 * Free @devt which was allocated using blk_alloc_devt().
588 void blk_free_devt(dev_t devt)
590 if (MAJOR(devt) == BLOCK_EXT_MAJOR)
591 ida_free(&ext_devt_ida, blk_mangle_minor(MINOR(devt)));
594 static char *bdevt_str(dev_t devt, char *buf)
596 if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
597 char tbuf[BDEVT_SIZE];
598 snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
599 snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
601 snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
606 static void disk_scan_partitions(struct gendisk *disk)
608 struct block_device *bdev;
610 if (!get_capacity(disk) || !disk_part_scan_enabled(disk))
613 set_bit(GD_NEED_PART_SCAN, &disk->state);
614 bdev = blkdev_get_by_dev(disk_devt(disk), FMODE_READ, NULL);
616 blkdev_put(bdev, FMODE_READ);
619 static void register_disk(struct device *parent, struct gendisk *disk,
620 const struct attribute_group **groups)
622 struct device *ddev = disk_to_dev(disk);
623 struct disk_part_iter piter;
624 struct block_device *part;
627 ddev->parent = parent;
629 dev_set_name(ddev, "%s", disk->disk_name);
631 /* delay uevents, until we scanned partition table */
632 dev_set_uevent_suppress(ddev, 1);
635 WARN_ON(ddev->groups);
636 ddev->groups = groups;
638 if (device_add(ddev))
640 if (!sysfs_deprecated) {
641 err = sysfs_create_link(block_depr, &ddev->kobj,
642 kobject_name(&ddev->kobj));
650 * avoid probable deadlock caused by allocating memory with
651 * GFP_KERNEL in runtime_resume callback of its all ancestor
654 pm_runtime_set_memalloc_noio(ddev, true);
656 disk->part0->bd_holder_dir =
657 kobject_create_and_add("holders", &ddev->kobj);
658 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
660 if (disk->flags & GENHD_FL_HIDDEN) {
661 dev_set_uevent_suppress(ddev, 0);
665 disk_scan_partitions(disk);
667 /* announce disk after possible partitions are created */
668 dev_set_uevent_suppress(ddev, 0);
669 kobject_uevent(&ddev->kobj, KOBJ_ADD);
671 /* announce possible partitions */
672 disk_part_iter_init(&piter, disk, 0);
673 while ((part = disk_part_iter_next(&piter)))
674 kobject_uevent(bdev_kobj(part), KOBJ_ADD);
675 disk_part_iter_exit(&piter);
677 if (disk->queue->backing_dev_info->dev) {
678 err = sysfs_create_link(&ddev->kobj,
679 &disk->queue->backing_dev_info->dev->kobj,
686 * __device_add_disk - add disk information to kernel list
687 * @parent: parent device for the disk
688 * @disk: per-device partitioning information
689 * @groups: Additional per-device sysfs groups
690 * @register_queue: register the queue if set to true
692 * This function registers the partitioning information in @disk
695 * FIXME: error handling
697 static void __device_add_disk(struct device *parent, struct gendisk *disk,
698 const struct attribute_group **groups,
705 * The disk queue should now be all set with enough information about
706 * the device for the elevator code to pick an adequate default
707 * elevator if one is needed, that is, for devices requesting queue
711 elevator_init_mq(disk->queue);
713 /* minors == 0 indicates to use ext devt from part0 and should
714 * be accompanied with EXT_DEVT flag. Make sure all
715 * parameters make sense.
717 WARN_ON(disk->minors && !(disk->major || disk->first_minor));
718 WARN_ON(!disk->minors &&
719 !(disk->flags & (GENHD_FL_EXT_DEVT | GENHD_FL_HIDDEN)));
721 disk->flags |= GENHD_FL_UP;
723 retval = blk_alloc_devt(disk->part0, &devt);
728 disk->major = MAJOR(devt);
729 disk->first_minor = MINOR(devt);
731 disk_alloc_events(disk);
733 if (disk->flags & GENHD_FL_HIDDEN) {
735 * Don't let hidden disks show up in /proc/partitions,
736 * and don't bother scanning for partitions either.
738 disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
739 disk->flags |= GENHD_FL_NO_PART_SCAN;
741 struct backing_dev_info *bdi = disk->queue->backing_dev_info;
742 struct device *dev = disk_to_dev(disk);
745 /* Register BDI before referencing it from bdev */
747 ret = bdi_register(bdi, "%u:%u", MAJOR(devt), MINOR(devt));
749 bdi_set_owner(bdi, dev);
750 bdev_add(disk->part0, devt);
752 register_disk(parent, disk, groups);
754 blk_register_queue(disk);
757 * Take an extra ref on queue which will be put on disk_release()
758 * so that it sticks around as long as @disk is there.
760 WARN_ON_ONCE(!blk_get_queue(disk->queue));
762 disk_add_events(disk);
763 blk_integrity_add(disk);
766 void device_add_disk(struct device *parent, struct gendisk *disk,
767 const struct attribute_group **groups)
770 __device_add_disk(parent, disk, groups, true);
772 EXPORT_SYMBOL(device_add_disk);
774 void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk)
776 __device_add_disk(parent, disk, NULL, false);
778 EXPORT_SYMBOL(device_add_disk_no_queue_reg);
780 static void invalidate_partition(struct block_device *bdev)
783 __invalidate_device(bdev, true);
786 * Unhash the bdev inode for this device so that it can't be looked
787 * up any more even if openers still hold references to it.
789 remove_inode_hash(bdev->bd_inode);
793 * del_gendisk - remove the gendisk
794 * @disk: the struct gendisk to remove
796 * Removes the gendisk and all its associated resources. This deletes the
797 * partitions associated with the gendisk, and unregisters the associated
800 * This is the counter to the respective __device_add_disk() call.
802 * The final removal of the struct gendisk happens when its refcount reaches 0
803 * with put_disk(), which should be called after del_gendisk(), if
804 * __device_add_disk() was used.
806 * Drivers exist which depend on the release of the gendisk to be synchronous,
807 * it should not be deferred.
811 void del_gendisk(struct gendisk *disk)
813 struct disk_part_iter piter;
814 struct block_device *part;
818 if (WARN_ON_ONCE(!disk->queue))
821 blk_integrity_del(disk);
822 disk_del_events(disk);
825 * Block lookups of the disk until all bdevs are unhashed and the
826 * disk is marked as dead (GENHD_FL_UP cleared).
828 down_write(&bdev_lookup_sem);
830 /* invalidate stuff */
831 disk_part_iter_init(&piter, disk,
832 DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
833 while ((part = disk_part_iter_next(&piter))) {
834 invalidate_partition(part);
835 delete_partition(part);
837 disk_part_iter_exit(&piter);
839 invalidate_partition(disk->part0);
840 set_capacity(disk, 0);
841 disk->flags &= ~GENHD_FL_UP;
842 up_write(&bdev_lookup_sem);
844 if (!(disk->flags & GENHD_FL_HIDDEN)) {
845 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
848 * Unregister bdi before releasing device numbers (as they can
849 * get reused and we'd get clashes in sysfs).
851 bdi_unregister(disk->queue->backing_dev_info);
854 blk_unregister_queue(disk);
856 kobject_put(disk->part0->bd_holder_dir);
857 kobject_put(disk->slave_dir);
859 part_stat_set_all(disk->part0, 0);
860 disk->part0->bd_stamp = 0;
861 if (!sysfs_deprecated)
862 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
863 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
864 device_del(disk_to_dev(disk));
866 EXPORT_SYMBOL(del_gendisk);
868 /* sysfs access to bad-blocks list. */
869 static ssize_t disk_badblocks_show(struct device *dev,
870 struct device_attribute *attr,
873 struct gendisk *disk = dev_to_disk(dev);
876 return sprintf(page, "\n");
878 return badblocks_show(disk->bb, page, 0);
881 static ssize_t disk_badblocks_store(struct device *dev,
882 struct device_attribute *attr,
883 const char *page, size_t len)
885 struct gendisk *disk = dev_to_disk(dev);
890 return badblocks_store(disk->bb, page, len, 0);
893 void blk_request_module(dev_t devt)
895 unsigned int major = MAJOR(devt);
896 struct blk_major_name **n;
898 mutex_lock(&major_names_lock);
899 for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) {
900 if ((*n)->major == major && (*n)->probe) {
902 mutex_unlock(&major_names_lock);
906 mutex_unlock(&major_names_lock);
908 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
909 /* Make old-style 2.4 aliases work */
910 request_module("block-major-%d", MAJOR(devt));
914 * bdget_disk - do bdget() by gendisk and partition number
915 * @disk: gendisk of interest
916 * @partno: partition number
918 * Find partition @partno from @disk, do bdget() on it.
924 * Resulting block_device on success, NULL on failure.
926 struct block_device *bdget_disk(struct gendisk *disk, int partno)
928 struct block_device *bdev = NULL;
931 bdev = __disk_get_part(disk, partno);
932 if (bdev && !bdgrab(bdev))
940 * print a full list of all partitions - intended for places where the root
941 * filesystem can't be mounted and thus to give the victim some idea of what
944 void __init printk_all_partitions(void)
946 struct class_dev_iter iter;
949 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
950 while ((dev = class_dev_iter_next(&iter))) {
951 struct gendisk *disk = dev_to_disk(dev);
952 struct disk_part_iter piter;
953 struct block_device *part;
954 char name_buf[BDEVNAME_SIZE];
955 char devt_buf[BDEVT_SIZE];
958 * Don't show empty devices or things that have been
961 if (get_capacity(disk) == 0 ||
962 (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
966 * Note, unlike /proc/partitions, I am showing the
967 * numbers in hex - the same format as the root=
970 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
971 while ((part = disk_part_iter_next(&piter))) {
972 bool is_part0 = part == disk->part0;
974 printk("%s%s %10llu %s %s", is_part0 ? "" : " ",
975 bdevt_str(part->bd_dev, devt_buf),
976 bdev_nr_sectors(part) >> 1,
977 disk_name(disk, part->bd_partno, name_buf),
979 part->bd_meta_info->uuid : "");
981 if (dev->parent && dev->parent->driver)
982 printk(" driver: %s\n",
983 dev->parent->driver->name);
985 printk(" (driver?)\n");
989 disk_part_iter_exit(&piter);
991 class_dev_iter_exit(&iter);
994 #ifdef CONFIG_PROC_FS
996 static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
999 struct class_dev_iter *iter;
1002 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
1004 return ERR_PTR(-ENOMEM);
1006 seqf->private = iter;
1007 class_dev_iter_init(iter, &block_class, NULL, &disk_type);
1009 dev = class_dev_iter_next(iter);
1014 return dev_to_disk(dev);
1017 static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
1022 dev = class_dev_iter_next(seqf->private);
1024 return dev_to_disk(dev);
1029 static void disk_seqf_stop(struct seq_file *seqf, void *v)
1031 struct class_dev_iter *iter = seqf->private;
1033 /* stop is called even after start failed :-( */
1035 class_dev_iter_exit(iter);
1037 seqf->private = NULL;
1041 static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
1045 p = disk_seqf_start(seqf, pos);
1046 if (!IS_ERR_OR_NULL(p) && !*pos)
1047 seq_puts(seqf, "major minor #blocks name\n\n");
1051 static int show_partition(struct seq_file *seqf, void *v)
1053 struct gendisk *sgp = v;
1054 struct disk_part_iter piter;
1055 struct block_device *part;
1056 char buf[BDEVNAME_SIZE];
1058 /* Don't show non-partitionable removeable devices or empty devices */
1059 if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
1060 (sgp->flags & GENHD_FL_REMOVABLE)))
1062 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
1065 /* show the full disk and all non-0 size partitions of it */
1066 disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
1067 while ((part = disk_part_iter_next(&piter)))
1068 seq_printf(seqf, "%4d %7d %10llu %s\n",
1069 MAJOR(part->bd_dev), MINOR(part->bd_dev),
1070 bdev_nr_sectors(part) >> 1,
1071 disk_name(sgp, part->bd_partno, buf));
1072 disk_part_iter_exit(&piter);
1077 static const struct seq_operations partitions_op = {
1078 .start = show_partition_start,
1079 .next = disk_seqf_next,
1080 .stop = disk_seqf_stop,
1081 .show = show_partition
1085 static int __init genhd_device_init(void)
1089 block_class.dev_kobj = sysfs_dev_block_kobj;
1090 error = class_register(&block_class);
1091 if (unlikely(error))
1095 register_blkdev(BLOCK_EXT_MAJOR, "blkext");
1097 /* create top-level block dir */
1098 if (!sysfs_deprecated)
1099 block_depr = kobject_create_and_add("block", NULL);
1103 subsys_initcall(genhd_device_init);
1105 static ssize_t disk_range_show(struct device *dev,
1106 struct device_attribute *attr, char *buf)
1108 struct gendisk *disk = dev_to_disk(dev);
1110 return sprintf(buf, "%d\n", disk->minors);
1113 static ssize_t disk_ext_range_show(struct device *dev,
1114 struct device_attribute *attr, char *buf)
1116 struct gendisk *disk = dev_to_disk(dev);
1118 return sprintf(buf, "%d\n", disk_max_parts(disk));
1121 static ssize_t disk_removable_show(struct device *dev,
1122 struct device_attribute *attr, char *buf)
1124 struct gendisk *disk = dev_to_disk(dev);
1126 return sprintf(buf, "%d\n",
1127 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
1130 static ssize_t disk_hidden_show(struct device *dev,
1131 struct device_attribute *attr, char *buf)
1133 struct gendisk *disk = dev_to_disk(dev);
1135 return sprintf(buf, "%d\n",
1136 (disk->flags & GENHD_FL_HIDDEN ? 1 : 0));
1139 static ssize_t disk_ro_show(struct device *dev,
1140 struct device_attribute *attr, char *buf)
1142 struct gendisk *disk = dev_to_disk(dev);
1144 return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
1147 ssize_t part_size_show(struct device *dev,
1148 struct device_attribute *attr, char *buf)
1150 return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));
1153 ssize_t part_stat_show(struct device *dev,
1154 struct device_attribute *attr, char *buf)
1156 struct block_device *bdev = dev_to_bdev(dev);
1157 struct request_queue *q = bdev->bd_disk->queue;
1158 struct disk_stats stat;
1159 unsigned int inflight;
1161 part_stat_read_all(bdev, &stat);
1163 inflight = blk_mq_in_flight(q, bdev);
1165 inflight = part_in_flight(bdev);
1168 "%8lu %8lu %8llu %8u "
1169 "%8lu %8lu %8llu %8u "
1171 "%8lu %8lu %8llu %8u "
1174 stat.ios[STAT_READ],
1175 stat.merges[STAT_READ],
1176 (unsigned long long)stat.sectors[STAT_READ],
1177 (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC),
1178 stat.ios[STAT_WRITE],
1179 stat.merges[STAT_WRITE],
1180 (unsigned long long)stat.sectors[STAT_WRITE],
1181 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC),
1183 jiffies_to_msecs(stat.io_ticks),
1184 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1185 stat.nsecs[STAT_WRITE] +
1186 stat.nsecs[STAT_DISCARD] +
1187 stat.nsecs[STAT_FLUSH],
1189 stat.ios[STAT_DISCARD],
1190 stat.merges[STAT_DISCARD],
1191 (unsigned long long)stat.sectors[STAT_DISCARD],
1192 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC),
1193 stat.ios[STAT_FLUSH],
1194 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC));
1197 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
1200 struct block_device *bdev = dev_to_bdev(dev);
1201 struct request_queue *q = bdev->bd_disk->queue;
1202 unsigned int inflight[2];
1205 blk_mq_in_flight_rw(q, bdev, inflight);
1207 part_in_flight_rw(bdev, inflight);
1209 return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
1212 static ssize_t disk_capability_show(struct device *dev,
1213 struct device_attribute *attr, char *buf)
1215 struct gendisk *disk = dev_to_disk(dev);
1217 return sprintf(buf, "%x\n", disk->flags);
1220 static ssize_t disk_alignment_offset_show(struct device *dev,
1221 struct device_attribute *attr,
1224 struct gendisk *disk = dev_to_disk(dev);
1226 return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue));
1229 static ssize_t disk_discard_alignment_show(struct device *dev,
1230 struct device_attribute *attr,
1233 struct gendisk *disk = dev_to_disk(dev);
1235 return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
1238 static DEVICE_ATTR(range, 0444, disk_range_show, NULL);
1239 static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL);
1240 static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL);
1241 static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL);
1242 static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL);
1243 static DEVICE_ATTR(size, 0444, part_size_show, NULL);
1244 static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL);
1245 static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL);
1246 static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL);
1247 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
1248 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
1249 static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
1251 #ifdef CONFIG_FAIL_MAKE_REQUEST
1252 ssize_t part_fail_show(struct device *dev,
1253 struct device_attribute *attr, char *buf)
1255 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail);
1258 ssize_t part_fail_store(struct device *dev,
1259 struct device_attribute *attr,
1260 const char *buf, size_t count)
1264 if (count > 0 && sscanf(buf, "%d", &i) > 0)
1265 dev_to_bdev(dev)->bd_make_it_fail = i;
1270 static struct device_attribute dev_attr_fail =
1271 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
1272 #endif /* CONFIG_FAIL_MAKE_REQUEST */
1274 #ifdef CONFIG_FAIL_IO_TIMEOUT
1275 static struct device_attribute dev_attr_fail_timeout =
1276 __ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store);
1279 static struct attribute *disk_attrs[] = {
1280 &dev_attr_range.attr,
1281 &dev_attr_ext_range.attr,
1282 &dev_attr_removable.attr,
1283 &dev_attr_hidden.attr,
1285 &dev_attr_size.attr,
1286 &dev_attr_alignment_offset.attr,
1287 &dev_attr_discard_alignment.attr,
1288 &dev_attr_capability.attr,
1289 &dev_attr_stat.attr,
1290 &dev_attr_inflight.attr,
1291 &dev_attr_badblocks.attr,
1292 #ifdef CONFIG_FAIL_MAKE_REQUEST
1293 &dev_attr_fail.attr,
1295 #ifdef CONFIG_FAIL_IO_TIMEOUT
1296 &dev_attr_fail_timeout.attr,
1301 static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n)
1303 struct device *dev = container_of(kobj, typeof(*dev), kobj);
1304 struct gendisk *disk = dev_to_disk(dev);
1306 if (a == &dev_attr_badblocks.attr && !disk->bb)
1311 static struct attribute_group disk_attr_group = {
1312 .attrs = disk_attrs,
1313 .is_visible = disk_visible,
1316 static const struct attribute_group *disk_attr_groups[] = {
1322 * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
1323 * @disk: disk to replace part_tbl for
1324 * @new_ptbl: new part_tbl to install
1326 * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The
1327 * original ptbl is freed using RCU callback.
1330 * Matching bd_mutex locked or the caller is the only user of @disk.
1332 static void disk_replace_part_tbl(struct gendisk *disk,
1333 struct disk_part_tbl *new_ptbl)
1335 struct disk_part_tbl *old_ptbl =
1336 rcu_dereference_protected(disk->part_tbl, 1);
1338 rcu_assign_pointer(disk->part_tbl, new_ptbl);
1341 rcu_assign_pointer(old_ptbl->last_lookup, NULL);
1342 kfree_rcu(old_ptbl, rcu_head);
1347 * disk_expand_part_tbl - expand disk->part_tbl
1348 * @disk: disk to expand part_tbl for
1349 * @partno: expand such that this partno can fit in
1351 * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl
1352 * uses RCU to allow unlocked dereferencing for stats and other stuff.
1355 * Matching bd_mutex locked or the caller is the only user of @disk.
1359 * 0 on success, -errno on failure.
1361 int disk_expand_part_tbl(struct gendisk *disk, int partno)
1363 struct disk_part_tbl *old_ptbl =
1364 rcu_dereference_protected(disk->part_tbl, 1);
1365 struct disk_part_tbl *new_ptbl;
1366 int len = old_ptbl ? old_ptbl->len : 0;
1370 * check for int overflow, since we can get here from blkpg_ioctl()
1371 * with a user passed 'partno'.
1373 target = partno + 1;
1377 /* disk_max_parts() is zero during initialization, ignore if so */
1378 if (disk_max_parts(disk) && target > disk_max_parts(disk))
1384 new_ptbl = kzalloc_node(struct_size(new_ptbl, part, target), GFP_KERNEL,
1389 new_ptbl->len = target;
1391 for (i = 0; i < len; i++)
1392 rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
1394 disk_replace_part_tbl(disk, new_ptbl);
1399 * disk_release - releases all allocated resources of the gendisk
1400 * @dev: the device representing this disk
1402 * This function releases all allocated resources of the gendisk.
1404 * Drivers which used __device_add_disk() have a gendisk with a request_queue
1405 * assigned. Since the request_queue sits on top of the gendisk for these
1406 * drivers we also call blk_put_queue() for them, and we expect the
1407 * request_queue refcount to reach 0 at this point, and so the request_queue
1408 * will also be freed prior to the disk.
1410 * Context: can sleep
1412 static void disk_release(struct device *dev)
1414 struct gendisk *disk = dev_to_disk(dev);
1418 blk_free_devt(dev->devt);
1419 disk_release_events(disk);
1420 kfree(disk->random);
1421 disk_replace_part_tbl(disk, NULL);
1424 blk_put_queue(disk->queue);
1427 struct class block_class = {
1431 static char *block_devnode(struct device *dev, umode_t *mode,
1432 kuid_t *uid, kgid_t *gid)
1434 struct gendisk *disk = dev_to_disk(dev);
1436 if (disk->fops->devnode)
1437 return disk->fops->devnode(disk, mode);
1441 const struct device_type disk_type = {
1443 .groups = disk_attr_groups,
1444 .release = disk_release,
1445 .devnode = block_devnode,
1448 #ifdef CONFIG_PROC_FS
1450 * aggregate disk stat collector. Uses the same stats that the sysfs
1451 * entries do, above, but makes them available through one seq_file.
1453 * The output looks suspiciously like /proc/partitions with a bunch of
1456 static int diskstats_show(struct seq_file *seqf, void *v)
1458 struct gendisk *gp = v;
1459 struct disk_part_iter piter;
1460 struct block_device *hd;
1461 char buf[BDEVNAME_SIZE];
1462 unsigned int inflight;
1463 struct disk_stats stat;
1466 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1467 seq_puts(seqf, "major minor name"
1468 " rio rmerge rsect ruse wio wmerge "
1469 "wsect wuse running use aveq"
1473 disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
1474 while ((hd = disk_part_iter_next(&piter))) {
1475 part_stat_read_all(hd, &stat);
1476 if (queue_is_mq(gp->queue))
1477 inflight = blk_mq_in_flight(gp->queue, hd);
1479 inflight = part_in_flight(hd);
1481 seq_printf(seqf, "%4d %7d %s "
1488 MAJOR(hd->bd_dev), MINOR(hd->bd_dev),
1489 disk_name(gp, hd->bd_partno, buf),
1490 stat.ios[STAT_READ],
1491 stat.merges[STAT_READ],
1492 stat.sectors[STAT_READ],
1493 (unsigned int)div_u64(stat.nsecs[STAT_READ],
1495 stat.ios[STAT_WRITE],
1496 stat.merges[STAT_WRITE],
1497 stat.sectors[STAT_WRITE],
1498 (unsigned int)div_u64(stat.nsecs[STAT_WRITE],
1501 jiffies_to_msecs(stat.io_ticks),
1502 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1503 stat.nsecs[STAT_WRITE] +
1504 stat.nsecs[STAT_DISCARD] +
1505 stat.nsecs[STAT_FLUSH],
1507 stat.ios[STAT_DISCARD],
1508 stat.merges[STAT_DISCARD],
1509 stat.sectors[STAT_DISCARD],
1510 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD],
1512 stat.ios[STAT_FLUSH],
1513 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH],
1517 disk_part_iter_exit(&piter);
1522 static const struct seq_operations diskstats_op = {
1523 .start = disk_seqf_start,
1524 .next = disk_seqf_next,
1525 .stop = disk_seqf_stop,
1526 .show = diskstats_show
1529 static int __init proc_genhd_init(void)
1531 proc_create_seq("diskstats", 0, NULL, &diskstats_op);
1532 proc_create_seq("partitions", 0, NULL, &partitions_op);
1535 module_init(proc_genhd_init);
1536 #endif /* CONFIG_PROC_FS */
1538 dev_t blk_lookup_devt(const char *name, int partno)
1540 dev_t devt = MKDEV(0, 0);
1541 struct class_dev_iter iter;
1544 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
1545 while ((dev = class_dev_iter_next(&iter))) {
1546 struct gendisk *disk = dev_to_disk(dev);
1547 struct block_device *part;
1549 if (strcmp(dev_name(dev), name))
1552 if (partno < disk->minors) {
1553 /* We need to return the right devno, even
1554 * if the partition doesn't exist yet.
1556 devt = MKDEV(MAJOR(dev->devt),
1557 MINOR(dev->devt) + partno);
1560 part = bdget_disk(disk, partno);
1562 devt = part->bd_dev;
1567 class_dev_iter_exit(&iter);
1571 struct gendisk *__alloc_disk_node(int minors, int node_id)
1573 struct gendisk *disk;
1574 struct disk_part_tbl *ptbl;
1576 if (minors > DISK_MAX_PARTS) {
1578 "block: can't allocate more than %d partitions\n",
1580 minors = DISK_MAX_PARTS;
1583 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
1587 disk->part0 = bdev_alloc(disk, 0);
1591 disk->node_id = node_id;
1592 if (disk_expand_part_tbl(disk, 0))
1595 ptbl = rcu_dereference_protected(disk->part_tbl, 1);
1596 rcu_assign_pointer(ptbl->part[0], disk->part0);
1598 disk->minors = minors;
1599 rand_initialize_disk(disk);
1600 disk_to_dev(disk)->class = &block_class;
1601 disk_to_dev(disk)->type = &disk_type;
1602 device_initialize(disk_to_dev(disk));
1611 EXPORT_SYMBOL(__alloc_disk_node);
1614 * put_disk - decrements the gendisk refcount
1615 * @disk: the struct gendisk to decrement the refcount for
1617 * This decrements the refcount for the struct gendisk. When this reaches 0
1618 * we'll have disk_release() called.
1620 * Context: Any context, but the last reference must not be dropped from
1623 void put_disk(struct gendisk *disk)
1626 put_device(disk_to_dev(disk));
1628 EXPORT_SYMBOL(put_disk);
1630 static void set_disk_ro_uevent(struct gendisk *gd, int ro)
1632 char event[] = "DISK_RO=1";
1633 char *envp[] = { event, NULL };
1637 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
1640 void set_disk_ro(struct gendisk *disk, int flag)
1642 struct disk_part_iter piter;
1643 struct block_device *part;
1645 if (disk->part0->bd_read_only != flag) {
1646 set_disk_ro_uevent(disk, flag);
1647 disk->part0->bd_read_only = flag;
1650 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
1651 while ((part = disk_part_iter_next(&piter)))
1652 part->bd_read_only = flag;
1653 disk_part_iter_exit(&piter);
1656 EXPORT_SYMBOL(set_disk_ro);
1658 int bdev_read_only(struct block_device *bdev)
1662 return bdev->bd_read_only;
1665 EXPORT_SYMBOL(bdev_read_only);
1668 * Disk events - monitor disk events like media change and eject request.
1670 struct disk_events {
1671 struct list_head node; /* all disk_event's */
1672 struct gendisk *disk; /* the associated disk */
1675 struct mutex block_mutex; /* protects blocking */
1676 int block; /* event blocking depth */
1677 unsigned int pending; /* events already sent out */
1678 unsigned int clearing; /* events being cleared */
1680 long poll_msecs; /* interval, -1 for default */
1681 struct delayed_work dwork;
1684 static const char *disk_events_strs[] = {
1685 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
1686 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
1689 static char *disk_uevents[] = {
1690 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
1691 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
1694 /* list of all disk_events */
1695 static DEFINE_MUTEX(disk_events_mutex);
1696 static LIST_HEAD(disk_events);
1698 /* disable in-kernel polling by default */
1699 static unsigned long disk_events_dfl_poll_msecs;
1701 static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
1703 struct disk_events *ev = disk->ev;
1704 long intv_msecs = 0;
1707 * If device-specific poll interval is set, always use it. If
1708 * the default is being used, poll if the POLL flag is set.
1710 if (ev->poll_msecs >= 0)
1711 intv_msecs = ev->poll_msecs;
1712 else if (disk->event_flags & DISK_EVENT_FLAG_POLL)
1713 intv_msecs = disk_events_dfl_poll_msecs;
1715 return msecs_to_jiffies(intv_msecs);
1719 * disk_block_events - block and flush disk event checking
1720 * @disk: disk to block events for
1722 * On return from this function, it is guaranteed that event checking
1723 * isn't in progress and won't happen until unblocked by
1724 * disk_unblock_events(). Events blocking is counted and the actual
1725 * unblocking happens after the matching number of unblocks are done.
1727 * Note that this intentionally does not block event checking from
1728 * disk_clear_events().
1733 void disk_block_events(struct gendisk *disk)
1735 struct disk_events *ev = disk->ev;
1736 unsigned long flags;
1743 * Outer mutex ensures that the first blocker completes canceling
1744 * the event work before further blockers are allowed to finish.
1746 mutex_lock(&ev->block_mutex);
1748 spin_lock_irqsave(&ev->lock, flags);
1749 cancel = !ev->block++;
1750 spin_unlock_irqrestore(&ev->lock, flags);
1753 cancel_delayed_work_sync(&disk->ev->dwork);
1755 mutex_unlock(&ev->block_mutex);
1758 static void __disk_unblock_events(struct gendisk *disk, bool check_now)
1760 struct disk_events *ev = disk->ev;
1762 unsigned long flags;
1764 spin_lock_irqsave(&ev->lock, flags);
1766 if (WARN_ON_ONCE(ev->block <= 0))
1772 intv = disk_events_poll_jiffies(disk);
1774 queue_delayed_work(system_freezable_power_efficient_wq,
1777 queue_delayed_work(system_freezable_power_efficient_wq,
1780 spin_unlock_irqrestore(&ev->lock, flags);
1784 * disk_unblock_events - unblock disk event checking
1785 * @disk: disk to unblock events for
1787 * Undo disk_block_events(). When the block count reaches zero, it
1788 * starts events polling if configured.
1791 * Don't care. Safe to call from irq context.
1793 void disk_unblock_events(struct gendisk *disk)
1796 __disk_unblock_events(disk, false);
1800 * disk_flush_events - schedule immediate event checking and flushing
1801 * @disk: disk to check and flush events for
1802 * @mask: events to flush
1804 * Schedule immediate event checking on @disk if not blocked. Events in
1805 * @mask are scheduled to be cleared from the driver. Note that this
1806 * doesn't clear the events from @disk->ev.
1809 * If @mask is non-zero must be called with bdev->bd_mutex held.
1811 void disk_flush_events(struct gendisk *disk, unsigned int mask)
1813 struct disk_events *ev = disk->ev;
1818 spin_lock_irq(&ev->lock);
1819 ev->clearing |= mask;
1821 mod_delayed_work(system_freezable_power_efficient_wq,
1823 spin_unlock_irq(&ev->lock);
1827 * disk_clear_events - synchronously check, clear and return pending events
1828 * @disk: disk to fetch and clear events from
1829 * @mask: mask of events to be fetched and cleared
1831 * Disk events are synchronously checked and pending events in @mask
1832 * are cleared and returned. This ignores the block count.
1837 static unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
1839 struct disk_events *ev = disk->ev;
1840 unsigned int pending;
1841 unsigned int clearing = mask;
1846 disk_block_events(disk);
1849 * store the union of mask and ev->clearing on the stack so that the
1850 * race with disk_flush_events does not cause ambiguity (ev->clearing
1851 * can still be modified even if events are blocked).
1853 spin_lock_irq(&ev->lock);
1854 clearing |= ev->clearing;
1856 spin_unlock_irq(&ev->lock);
1858 disk_check_events(ev, &clearing);
1860 * if ev->clearing is not 0, the disk_flush_events got called in the
1861 * middle of this function, so we want to run the workfn without delay.
1863 __disk_unblock_events(disk, ev->clearing ? true : false);
1865 /* then, fetch and clear pending events */
1866 spin_lock_irq(&ev->lock);
1867 pending = ev->pending & mask;
1868 ev->pending &= ~mask;
1869 spin_unlock_irq(&ev->lock);
1870 WARN_ON_ONCE(clearing & mask);
1876 * bdev_check_media_change - check if a removable media has been changed
1877 * @bdev: block device to check
1879 * Check whether a removable media has been changed, and attempt to free all
1880 * dentries and inodes and invalidates all block device page cache entries in
1883 * Returns %true if the block device changed, or %false if not.
1885 bool bdev_check_media_change(struct block_device *bdev)
1887 unsigned int events;
1889 events = disk_clear_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE |
1890 DISK_EVENT_EJECT_REQUEST);
1891 if (!(events & DISK_EVENT_MEDIA_CHANGE))
1894 if (__invalidate_device(bdev, true))
1895 pr_warn("VFS: busy inodes on changed media %s\n",
1896 bdev->bd_disk->disk_name);
1897 set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
1900 EXPORT_SYMBOL(bdev_check_media_change);
1903 * Separate this part out so that a different pointer for clearing_ptr can be
1904 * passed in for disk_clear_events.
1906 static void disk_events_workfn(struct work_struct *work)
1908 struct delayed_work *dwork = to_delayed_work(work);
1909 struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
1911 disk_check_events(ev, &ev->clearing);
1914 static void disk_check_events(struct disk_events *ev,
1915 unsigned int *clearing_ptr)
1917 struct gendisk *disk = ev->disk;
1918 char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
1919 unsigned int clearing = *clearing_ptr;
1920 unsigned int events;
1922 int nr_events = 0, i;
1925 events = disk->fops->check_events(disk, clearing);
1927 /* accumulate pending events and schedule next poll if necessary */
1928 spin_lock_irq(&ev->lock);
1930 events &= ~ev->pending;
1931 ev->pending |= events;
1932 *clearing_ptr &= ~clearing;
1934 intv = disk_events_poll_jiffies(disk);
1935 if (!ev->block && intv)
1936 queue_delayed_work(system_freezable_power_efficient_wq,
1939 spin_unlock_irq(&ev->lock);
1942 * Tell userland about new events. Only the events listed in
1943 * @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT
1944 * is set. Otherwise, events are processed internally but never
1945 * get reported to userland.
1947 for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
1948 if ((events & disk->events & (1 << i)) &&
1949 (disk->event_flags & DISK_EVENT_FLAG_UEVENT))
1950 envp[nr_events++] = disk_uevents[i];
1953 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
1957 * A disk events enabled device has the following sysfs nodes under
1958 * its /sys/block/X/ directory.
1960 * events : list of all supported events
1961 * events_async : list of events which can be detected w/o polling
1962 * (always empty, only for backwards compatibility)
1963 * events_poll_msecs : polling interval, 0: disable, -1: system default
1965 static ssize_t __disk_events_show(unsigned int events, char *buf)
1967 const char *delim = "";
1971 for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
1972 if (events & (1 << i)) {
1973 pos += sprintf(buf + pos, "%s%s",
1974 delim, disk_events_strs[i]);
1978 pos += sprintf(buf + pos, "\n");
1982 static ssize_t disk_events_show(struct device *dev,
1983 struct device_attribute *attr, char *buf)
1985 struct gendisk *disk = dev_to_disk(dev);
1987 if (!(disk->event_flags & DISK_EVENT_FLAG_UEVENT))
1990 return __disk_events_show(disk->events, buf);
1993 static ssize_t disk_events_async_show(struct device *dev,
1994 struct device_attribute *attr, char *buf)
1999 static ssize_t disk_events_poll_msecs_show(struct device *dev,
2000 struct device_attribute *attr,
2003 struct gendisk *disk = dev_to_disk(dev);
2006 return sprintf(buf, "-1\n");
2008 return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
2011 static ssize_t disk_events_poll_msecs_store(struct device *dev,
2012 struct device_attribute *attr,
2013 const char *buf, size_t count)
2015 struct gendisk *disk = dev_to_disk(dev);
2018 if (!count || !sscanf(buf, "%ld", &intv))
2021 if (intv < 0 && intv != -1)
2027 disk_block_events(disk);
2028 disk->ev->poll_msecs = intv;
2029 __disk_unblock_events(disk, true);
2034 static const DEVICE_ATTR(events, 0444, disk_events_show, NULL);
2035 static const DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL);
2036 static const DEVICE_ATTR(events_poll_msecs, 0644,
2037 disk_events_poll_msecs_show,
2038 disk_events_poll_msecs_store);
2040 static const struct attribute *disk_events_attrs[] = {
2041 &dev_attr_events.attr,
2042 &dev_attr_events_async.attr,
2043 &dev_attr_events_poll_msecs.attr,
2048 * The default polling interval can be specified by the kernel
2049 * parameter block.events_dfl_poll_msecs which defaults to 0
2050 * (disable). This can also be modified runtime by writing to
2051 * /sys/module/block/parameters/events_dfl_poll_msecs.
2053 static int disk_events_set_dfl_poll_msecs(const char *val,
2054 const struct kernel_param *kp)
2056 struct disk_events *ev;
2059 ret = param_set_ulong(val, kp);
2063 mutex_lock(&disk_events_mutex);
2065 list_for_each_entry(ev, &disk_events, node)
2066 disk_flush_events(ev->disk, 0);
2068 mutex_unlock(&disk_events_mutex);
2073 static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
2074 .set = disk_events_set_dfl_poll_msecs,
2075 .get = param_get_ulong,
2078 #undef MODULE_PARAM_PREFIX
2079 #define MODULE_PARAM_PREFIX "block."
2081 module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
2082 &disk_events_dfl_poll_msecs, 0644);
2085 * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
2087 static void disk_alloc_events(struct gendisk *disk)
2089 struct disk_events *ev;
2091 if (!disk->fops->check_events || !disk->events)
2094 ev = kzalloc(sizeof(*ev), GFP_KERNEL);
2096 pr_warn("%s: failed to initialize events\n", disk->disk_name);
2100 INIT_LIST_HEAD(&ev->node);
2102 spin_lock_init(&ev->lock);
2103 mutex_init(&ev->block_mutex);
2105 ev->poll_msecs = -1;
2106 INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
2111 static void disk_add_events(struct gendisk *disk)
2113 /* FIXME: error handling */
2114 if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
2115 pr_warn("%s: failed to create sysfs files for events\n",
2121 mutex_lock(&disk_events_mutex);
2122 list_add_tail(&disk->ev->node, &disk_events);
2123 mutex_unlock(&disk_events_mutex);
2126 * Block count is initialized to 1 and the following initial
2127 * unblock kicks it into action.
2129 __disk_unblock_events(disk, true);
2132 static void disk_del_events(struct gendisk *disk)
2135 disk_block_events(disk);
2137 mutex_lock(&disk_events_mutex);
2138 list_del_init(&disk->ev->node);
2139 mutex_unlock(&disk_events_mutex);
2142 sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
2145 static void disk_release_events(struct gendisk *disk)
2147 /* the block count should be 1 from disk_del_events() */
2148 WARN_ON_ONCE(disk->ev && disk->ev->block != 1);