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, capacity, size);
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)
165 * disk_part_iter_init - initialize partition iterator
166 * @piter: iterator to initialize
167 * @disk: disk to iterate over
168 * @flags: DISK_PITER_* flags
170 * Initialize @piter so that it iterates over partitions of @disk.
175 void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
180 if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
184 piter->flags = flags;
188 * disk_part_iter_next - proceed iterator to the next partition and return it
189 * @piter: iterator of interest
191 * Proceed @piter to the next partition and return it.
196 struct block_device *disk_part_iter_next(struct disk_part_iter *piter)
198 struct block_device *part;
201 /* put the last partition */
202 disk_part_iter_exit(piter);
205 xa_for_each_start(&piter->disk->part_tbl, idx, part, piter->idx) {
206 if (!bdev_nr_sectors(part) &&
207 !(piter->flags & DISK_PITER_INCL_EMPTY) &&
208 !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
212 piter->part = bdgrab(part);
215 piter->idx = idx + 1;
224 * disk_part_iter_exit - finish up partition iteration
225 * @piter: iter of interest
227 * Called when iteration is over. Cleans up @piter.
232 void disk_part_iter_exit(struct disk_part_iter *piter)
240 * Can be deleted altogether. Later.
243 #define BLKDEV_MAJOR_HASH_SIZE 255
244 static struct blk_major_name {
245 struct blk_major_name *next;
248 void (*probe)(dev_t devt);
249 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
250 static DEFINE_MUTEX(major_names_lock);
252 /* index in the above - for now: assume no multimajor ranges */
253 static inline int major_to_index(unsigned major)
255 return major % BLKDEV_MAJOR_HASH_SIZE;
258 #ifdef CONFIG_PROC_FS
259 void blkdev_show(struct seq_file *seqf, off_t offset)
261 struct blk_major_name *dp;
263 mutex_lock(&major_names_lock);
264 for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next)
265 if (dp->major == offset)
266 seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
267 mutex_unlock(&major_names_lock);
269 #endif /* CONFIG_PROC_FS */
272 * __register_blkdev - register a new block device
274 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
275 * @major = 0, try to allocate any unused major number.
276 * @name: the name of the new block device as a zero terminated string
277 * @probe: allback that is called on access to any minor number of @major
279 * The @name must be unique within the system.
281 * The return value depends on the @major input parameter:
283 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
284 * then the function returns zero on success, or a negative error code
285 * - if any unused major number was requested with @major = 0 parameter
286 * then the return value is the allocated major number in range
287 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
289 * See Documentation/admin-guide/devices.txt for the list of allocated
292 * Use register_blkdev instead for any new code.
294 int __register_blkdev(unsigned int major, const char *name,
295 void (*probe)(dev_t devt))
297 struct blk_major_name **n, *p;
300 mutex_lock(&major_names_lock);
304 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
305 if (major_names[index] == NULL)
310 printk("%s: failed to get major for %s\n",
319 if (major >= BLKDEV_MAJOR_MAX) {
320 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
321 __func__, major, BLKDEV_MAJOR_MAX-1, name);
327 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
335 strlcpy(p->name, name, sizeof(p->name));
337 index = major_to_index(major);
339 for (n = &major_names[index]; *n; n = &(*n)->next) {
340 if ((*n)->major == major)
349 printk("register_blkdev: cannot get major %u for %s\n",
354 mutex_unlock(&major_names_lock);
357 EXPORT_SYMBOL(__register_blkdev);
359 void unregister_blkdev(unsigned int major, const char *name)
361 struct blk_major_name **n;
362 struct blk_major_name *p = NULL;
363 int index = major_to_index(major);
365 mutex_lock(&major_names_lock);
366 for (n = &major_names[index]; *n; n = &(*n)->next)
367 if ((*n)->major == major)
369 if (!*n || strcmp((*n)->name, name)) {
375 mutex_unlock(&major_names_lock);
379 EXPORT_SYMBOL(unregister_blkdev);
382 * blk_mangle_minor - scatter minor numbers apart
383 * @minor: minor number to mangle
385 * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
386 * is enabled. Mangling twice gives the original value.
394 static int blk_mangle_minor(int minor)
396 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
399 for (i = 0; i < MINORBITS / 2; i++) {
400 int low = minor & (1 << i);
401 int high = minor & (1 << (MINORBITS - 1 - i));
402 int distance = MINORBITS - 1 - 2 * i;
404 minor ^= low | high; /* clear both bits */
405 low <<= distance; /* swap the positions */
407 minor |= low | high; /* and set */
414 * blk_alloc_devt - allocate a dev_t for a block device
415 * @bdev: block device to allocate dev_t for
416 * @devt: out parameter for resulting dev_t
418 * Allocate a dev_t for block device.
421 * 0 on success, allocated dev_t is returned in *@devt. -errno on
427 int blk_alloc_devt(struct block_device *bdev, dev_t *devt)
429 struct gendisk *disk = bdev->bd_disk;
432 /* in consecutive minor range? */
433 if (bdev->bd_partno < disk->minors) {
434 *devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
438 idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT, GFP_KERNEL);
440 return idx == -ENOSPC ? -EBUSY : idx;
442 *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
447 * blk_free_devt - free a dev_t
448 * @devt: dev_t to free
450 * Free @devt which was allocated using blk_alloc_devt().
455 void blk_free_devt(dev_t devt)
457 if (MAJOR(devt) == BLOCK_EXT_MAJOR)
458 ida_free(&ext_devt_ida, blk_mangle_minor(MINOR(devt)));
461 static char *bdevt_str(dev_t devt, char *buf)
463 if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
464 char tbuf[BDEVT_SIZE];
465 snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
466 snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
468 snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
473 void disk_uevent(struct gendisk *disk, enum kobject_action action)
475 struct disk_part_iter piter;
476 struct block_device *part;
478 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY_PART0);
479 while ((part = disk_part_iter_next(&piter)))
480 kobject_uevent(bdev_kobj(part), action);
481 disk_part_iter_exit(&piter);
483 EXPORT_SYMBOL_GPL(disk_uevent);
485 static void disk_scan_partitions(struct gendisk *disk)
487 struct block_device *bdev;
489 if (!get_capacity(disk) || !disk_part_scan_enabled(disk))
492 set_bit(GD_NEED_PART_SCAN, &disk->state);
493 bdev = blkdev_get_by_dev(disk_devt(disk), FMODE_READ, NULL);
495 blkdev_put(bdev, FMODE_READ);
498 static void register_disk(struct device *parent, struct gendisk *disk,
499 const struct attribute_group **groups)
501 struct device *ddev = disk_to_dev(disk);
504 ddev->parent = parent;
506 dev_set_name(ddev, "%s", disk->disk_name);
508 /* delay uevents, until we scanned partition table */
509 dev_set_uevent_suppress(ddev, 1);
512 WARN_ON(ddev->groups);
513 ddev->groups = groups;
515 if (device_add(ddev))
517 if (!sysfs_deprecated) {
518 err = sysfs_create_link(block_depr, &ddev->kobj,
519 kobject_name(&ddev->kobj));
527 * avoid probable deadlock caused by allocating memory with
528 * GFP_KERNEL in runtime_resume callback of its all ancestor
531 pm_runtime_set_memalloc_noio(ddev, true);
533 disk->part0->bd_holder_dir =
534 kobject_create_and_add("holders", &ddev->kobj);
535 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
537 if (disk->flags & GENHD_FL_HIDDEN)
540 disk_scan_partitions(disk);
542 /* announce the disk and partitions after all partitions are created */
543 dev_set_uevent_suppress(ddev, 0);
544 disk_uevent(disk, KOBJ_ADD);
546 if (disk->queue->backing_dev_info->dev) {
547 err = sysfs_create_link(&ddev->kobj,
548 &disk->queue->backing_dev_info->dev->kobj,
555 * __device_add_disk - add disk information to kernel list
556 * @parent: parent device for the disk
557 * @disk: per-device partitioning information
558 * @groups: Additional per-device sysfs groups
559 * @register_queue: register the queue if set to true
561 * This function registers the partitioning information in @disk
564 * FIXME: error handling
566 static void __device_add_disk(struct device *parent, struct gendisk *disk,
567 const struct attribute_group **groups,
574 * The disk queue should now be all set with enough information about
575 * the device for the elevator code to pick an adequate default
576 * elevator if one is needed, that is, for devices requesting queue
580 elevator_init_mq(disk->queue);
582 /* minors == 0 indicates to use ext devt from part0 and should
583 * be accompanied with EXT_DEVT flag. Make sure all
584 * parameters make sense.
586 WARN_ON(disk->minors && !(disk->major || disk->first_minor));
587 WARN_ON(!disk->minors &&
588 !(disk->flags & (GENHD_FL_EXT_DEVT | GENHD_FL_HIDDEN)));
590 disk->flags |= GENHD_FL_UP;
592 retval = blk_alloc_devt(disk->part0, &devt);
597 disk->major = MAJOR(devt);
598 disk->first_minor = MINOR(devt);
600 disk_alloc_events(disk);
602 if (disk->flags & GENHD_FL_HIDDEN) {
604 * Don't let hidden disks show up in /proc/partitions,
605 * and don't bother scanning for partitions either.
607 disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
608 disk->flags |= GENHD_FL_NO_PART_SCAN;
610 struct backing_dev_info *bdi = disk->queue->backing_dev_info;
611 struct device *dev = disk_to_dev(disk);
614 /* Register BDI before referencing it from bdev */
616 ret = bdi_register(bdi, "%u:%u", MAJOR(devt), MINOR(devt));
618 bdi_set_owner(bdi, dev);
619 bdev_add(disk->part0, devt);
621 register_disk(parent, disk, groups);
623 blk_register_queue(disk);
626 * Take an extra ref on queue which will be put on disk_release()
627 * so that it sticks around as long as @disk is there.
629 WARN_ON_ONCE(!blk_get_queue(disk->queue));
631 disk_add_events(disk);
632 blk_integrity_add(disk);
635 void device_add_disk(struct device *parent, struct gendisk *disk,
636 const struct attribute_group **groups)
639 __device_add_disk(parent, disk, groups, true);
641 EXPORT_SYMBOL(device_add_disk);
643 void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk)
645 __device_add_disk(parent, disk, NULL, false);
647 EXPORT_SYMBOL(device_add_disk_no_queue_reg);
649 static void invalidate_partition(struct block_device *bdev)
652 __invalidate_device(bdev, true);
655 * Unhash the bdev inode for this device so that it can't be looked
656 * up any more even if openers still hold references to it.
658 remove_inode_hash(bdev->bd_inode);
662 * del_gendisk - remove the gendisk
663 * @disk: the struct gendisk to remove
665 * Removes the gendisk and all its associated resources. This deletes the
666 * partitions associated with the gendisk, and unregisters the associated
669 * This is the counter to the respective __device_add_disk() call.
671 * The final removal of the struct gendisk happens when its refcount reaches 0
672 * with put_disk(), which should be called after del_gendisk(), if
673 * __device_add_disk() was used.
675 * Drivers exist which depend on the release of the gendisk to be synchronous,
676 * it should not be deferred.
680 void del_gendisk(struct gendisk *disk)
682 struct disk_part_iter piter;
683 struct block_device *part;
687 if (WARN_ON_ONCE(!disk->queue))
690 blk_integrity_del(disk);
691 disk_del_events(disk);
694 * Block lookups of the disk until all bdevs are unhashed and the
695 * disk is marked as dead (GENHD_FL_UP cleared).
697 down_write(&bdev_lookup_sem);
699 /* invalidate stuff */
700 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
701 while ((part = disk_part_iter_next(&piter))) {
702 invalidate_partition(part);
703 delete_partition(part);
705 disk_part_iter_exit(&piter);
707 invalidate_partition(disk->part0);
708 set_capacity(disk, 0);
709 disk->flags &= ~GENHD_FL_UP;
710 up_write(&bdev_lookup_sem);
712 if (!(disk->flags & GENHD_FL_HIDDEN)) {
713 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
716 * Unregister bdi before releasing device numbers (as they can
717 * get reused and we'd get clashes in sysfs).
719 bdi_unregister(disk->queue->backing_dev_info);
722 blk_unregister_queue(disk);
724 kobject_put(disk->part0->bd_holder_dir);
725 kobject_put(disk->slave_dir);
727 part_stat_set_all(disk->part0, 0);
728 disk->part0->bd_stamp = 0;
729 if (!sysfs_deprecated)
730 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
731 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
732 device_del(disk_to_dev(disk));
734 EXPORT_SYMBOL(del_gendisk);
736 /* sysfs access to bad-blocks list. */
737 static ssize_t disk_badblocks_show(struct device *dev,
738 struct device_attribute *attr,
741 struct gendisk *disk = dev_to_disk(dev);
744 return sprintf(page, "\n");
746 return badblocks_show(disk->bb, page, 0);
749 static ssize_t disk_badblocks_store(struct device *dev,
750 struct device_attribute *attr,
751 const char *page, size_t len)
753 struct gendisk *disk = dev_to_disk(dev);
758 return badblocks_store(disk->bb, page, len, 0);
761 void blk_request_module(dev_t devt)
763 unsigned int major = MAJOR(devt);
764 struct blk_major_name **n;
766 mutex_lock(&major_names_lock);
767 for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) {
768 if ((*n)->major == major && (*n)->probe) {
770 mutex_unlock(&major_names_lock);
774 mutex_unlock(&major_names_lock);
776 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
777 /* Make old-style 2.4 aliases work */
778 request_module("block-major-%d", MAJOR(devt));
782 * bdget_disk - do bdget() by gendisk and partition number
783 * @disk: gendisk of interest
784 * @partno: partition number
786 * Find partition @partno from @disk, do bdget() on it.
792 * Resulting block_device on success, NULL on failure.
794 struct block_device *bdget_disk(struct gendisk *disk, int partno)
796 struct block_device *bdev = NULL;
799 bdev = xa_load(&disk->part_tbl, partno);
800 if (bdev && !bdgrab(bdev))
808 * print a full list of all partitions - intended for places where the root
809 * filesystem can't be mounted and thus to give the victim some idea of what
812 void __init printk_all_partitions(void)
814 struct class_dev_iter iter;
817 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
818 while ((dev = class_dev_iter_next(&iter))) {
819 struct gendisk *disk = dev_to_disk(dev);
820 struct disk_part_iter piter;
821 struct block_device *part;
822 char name_buf[BDEVNAME_SIZE];
823 char devt_buf[BDEVT_SIZE];
826 * Don't show empty devices or things that have been
829 if (get_capacity(disk) == 0 ||
830 (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
834 * Note, unlike /proc/partitions, I am showing the
835 * numbers in hex - the same format as the root=
838 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
839 while ((part = disk_part_iter_next(&piter))) {
840 bool is_part0 = part == disk->part0;
842 printk("%s%s %10llu %s %s", is_part0 ? "" : " ",
843 bdevt_str(part->bd_dev, devt_buf),
844 bdev_nr_sectors(part) >> 1,
845 disk_name(disk, part->bd_partno, name_buf),
847 part->bd_meta_info->uuid : "");
849 if (dev->parent && dev->parent->driver)
850 printk(" driver: %s\n",
851 dev->parent->driver->name);
853 printk(" (driver?)\n");
857 disk_part_iter_exit(&piter);
859 class_dev_iter_exit(&iter);
862 #ifdef CONFIG_PROC_FS
864 static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
867 struct class_dev_iter *iter;
870 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
872 return ERR_PTR(-ENOMEM);
874 seqf->private = iter;
875 class_dev_iter_init(iter, &block_class, NULL, &disk_type);
877 dev = class_dev_iter_next(iter);
882 return dev_to_disk(dev);
885 static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
890 dev = class_dev_iter_next(seqf->private);
892 return dev_to_disk(dev);
897 static void disk_seqf_stop(struct seq_file *seqf, void *v)
899 struct class_dev_iter *iter = seqf->private;
901 /* stop is called even after start failed :-( */
903 class_dev_iter_exit(iter);
905 seqf->private = NULL;
909 static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
913 p = disk_seqf_start(seqf, pos);
914 if (!IS_ERR_OR_NULL(p) && !*pos)
915 seq_puts(seqf, "major minor #blocks name\n\n");
919 static int show_partition(struct seq_file *seqf, void *v)
921 struct gendisk *sgp = v;
922 struct disk_part_iter piter;
923 struct block_device *part;
924 char buf[BDEVNAME_SIZE];
926 /* Don't show non-partitionable removeable devices or empty devices */
927 if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
928 (sgp->flags & GENHD_FL_REMOVABLE)))
930 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
933 /* show the full disk and all non-0 size partitions of it */
934 disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
935 while ((part = disk_part_iter_next(&piter)))
936 seq_printf(seqf, "%4d %7d %10llu %s\n",
937 MAJOR(part->bd_dev), MINOR(part->bd_dev),
938 bdev_nr_sectors(part) >> 1,
939 disk_name(sgp, part->bd_partno, buf));
940 disk_part_iter_exit(&piter);
945 static const struct seq_operations partitions_op = {
946 .start = show_partition_start,
947 .next = disk_seqf_next,
948 .stop = disk_seqf_stop,
949 .show = show_partition
953 static int __init genhd_device_init(void)
957 block_class.dev_kobj = sysfs_dev_block_kobj;
958 error = class_register(&block_class);
963 register_blkdev(BLOCK_EXT_MAJOR, "blkext");
965 /* create top-level block dir */
966 if (!sysfs_deprecated)
967 block_depr = kobject_create_and_add("block", NULL);
971 subsys_initcall(genhd_device_init);
973 static ssize_t disk_range_show(struct device *dev,
974 struct device_attribute *attr, char *buf)
976 struct gendisk *disk = dev_to_disk(dev);
978 return sprintf(buf, "%d\n", disk->minors);
981 static ssize_t disk_ext_range_show(struct device *dev,
982 struct device_attribute *attr, char *buf)
984 struct gendisk *disk = dev_to_disk(dev);
986 return sprintf(buf, "%d\n", disk_max_parts(disk));
989 static ssize_t disk_removable_show(struct device *dev,
990 struct device_attribute *attr, char *buf)
992 struct gendisk *disk = dev_to_disk(dev);
994 return sprintf(buf, "%d\n",
995 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
998 static ssize_t disk_hidden_show(struct device *dev,
999 struct device_attribute *attr, char *buf)
1001 struct gendisk *disk = dev_to_disk(dev);
1003 return sprintf(buf, "%d\n",
1004 (disk->flags & GENHD_FL_HIDDEN ? 1 : 0));
1007 static ssize_t disk_ro_show(struct device *dev,
1008 struct device_attribute *attr, char *buf)
1010 struct gendisk *disk = dev_to_disk(dev);
1012 return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
1015 ssize_t part_size_show(struct device *dev,
1016 struct device_attribute *attr, char *buf)
1018 return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));
1021 ssize_t part_stat_show(struct device *dev,
1022 struct device_attribute *attr, char *buf)
1024 struct block_device *bdev = dev_to_bdev(dev);
1025 struct request_queue *q = bdev->bd_disk->queue;
1026 struct disk_stats stat;
1027 unsigned int inflight;
1029 part_stat_read_all(bdev, &stat);
1031 inflight = blk_mq_in_flight(q, bdev);
1033 inflight = part_in_flight(bdev);
1036 "%8lu %8lu %8llu %8u "
1037 "%8lu %8lu %8llu %8u "
1039 "%8lu %8lu %8llu %8u "
1042 stat.ios[STAT_READ],
1043 stat.merges[STAT_READ],
1044 (unsigned long long)stat.sectors[STAT_READ],
1045 (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC),
1046 stat.ios[STAT_WRITE],
1047 stat.merges[STAT_WRITE],
1048 (unsigned long long)stat.sectors[STAT_WRITE],
1049 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC),
1051 jiffies_to_msecs(stat.io_ticks),
1052 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1053 stat.nsecs[STAT_WRITE] +
1054 stat.nsecs[STAT_DISCARD] +
1055 stat.nsecs[STAT_FLUSH],
1057 stat.ios[STAT_DISCARD],
1058 stat.merges[STAT_DISCARD],
1059 (unsigned long long)stat.sectors[STAT_DISCARD],
1060 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC),
1061 stat.ios[STAT_FLUSH],
1062 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC));
1065 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
1068 struct block_device *bdev = dev_to_bdev(dev);
1069 struct request_queue *q = bdev->bd_disk->queue;
1070 unsigned int inflight[2];
1073 blk_mq_in_flight_rw(q, bdev, inflight);
1075 part_in_flight_rw(bdev, inflight);
1077 return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
1080 static ssize_t disk_capability_show(struct device *dev,
1081 struct device_attribute *attr, char *buf)
1083 struct gendisk *disk = dev_to_disk(dev);
1085 return sprintf(buf, "%x\n", disk->flags);
1088 static ssize_t disk_alignment_offset_show(struct device *dev,
1089 struct device_attribute *attr,
1092 struct gendisk *disk = dev_to_disk(dev);
1094 return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue));
1097 static ssize_t disk_discard_alignment_show(struct device *dev,
1098 struct device_attribute *attr,
1101 struct gendisk *disk = dev_to_disk(dev);
1103 return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
1106 static DEVICE_ATTR(range, 0444, disk_range_show, NULL);
1107 static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL);
1108 static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL);
1109 static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL);
1110 static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL);
1111 static DEVICE_ATTR(size, 0444, part_size_show, NULL);
1112 static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL);
1113 static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL);
1114 static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL);
1115 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
1116 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
1117 static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
1119 #ifdef CONFIG_FAIL_MAKE_REQUEST
1120 ssize_t part_fail_show(struct device *dev,
1121 struct device_attribute *attr, char *buf)
1123 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail);
1126 ssize_t part_fail_store(struct device *dev,
1127 struct device_attribute *attr,
1128 const char *buf, size_t count)
1132 if (count > 0 && sscanf(buf, "%d", &i) > 0)
1133 dev_to_bdev(dev)->bd_make_it_fail = i;
1138 static struct device_attribute dev_attr_fail =
1139 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
1140 #endif /* CONFIG_FAIL_MAKE_REQUEST */
1142 #ifdef CONFIG_FAIL_IO_TIMEOUT
1143 static struct device_attribute dev_attr_fail_timeout =
1144 __ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store);
1147 static struct attribute *disk_attrs[] = {
1148 &dev_attr_range.attr,
1149 &dev_attr_ext_range.attr,
1150 &dev_attr_removable.attr,
1151 &dev_attr_hidden.attr,
1153 &dev_attr_size.attr,
1154 &dev_attr_alignment_offset.attr,
1155 &dev_attr_discard_alignment.attr,
1156 &dev_attr_capability.attr,
1157 &dev_attr_stat.attr,
1158 &dev_attr_inflight.attr,
1159 &dev_attr_badblocks.attr,
1160 #ifdef CONFIG_FAIL_MAKE_REQUEST
1161 &dev_attr_fail.attr,
1163 #ifdef CONFIG_FAIL_IO_TIMEOUT
1164 &dev_attr_fail_timeout.attr,
1169 static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n)
1171 struct device *dev = container_of(kobj, typeof(*dev), kobj);
1172 struct gendisk *disk = dev_to_disk(dev);
1174 if (a == &dev_attr_badblocks.attr && !disk->bb)
1179 static struct attribute_group disk_attr_group = {
1180 .attrs = disk_attrs,
1181 .is_visible = disk_visible,
1184 static const struct attribute_group *disk_attr_groups[] = {
1190 * disk_release - releases all allocated resources of the gendisk
1191 * @dev: the device representing this disk
1193 * This function releases all allocated resources of the gendisk.
1195 * Drivers which used __device_add_disk() have a gendisk with a request_queue
1196 * assigned. Since the request_queue sits on top of the gendisk for these
1197 * drivers we also call blk_put_queue() for them, and we expect the
1198 * request_queue refcount to reach 0 at this point, and so the request_queue
1199 * will also be freed prior to the disk.
1201 * Context: can sleep
1203 static void disk_release(struct device *dev)
1205 struct gendisk *disk = dev_to_disk(dev);
1209 blk_free_devt(dev->devt);
1210 disk_release_events(disk);
1211 kfree(disk->random);
1212 xa_destroy(&disk->part_tbl);
1215 blk_put_queue(disk->queue);
1218 struct class block_class = {
1222 static char *block_devnode(struct device *dev, umode_t *mode,
1223 kuid_t *uid, kgid_t *gid)
1225 struct gendisk *disk = dev_to_disk(dev);
1227 if (disk->fops->devnode)
1228 return disk->fops->devnode(disk, mode);
1232 const struct device_type disk_type = {
1234 .groups = disk_attr_groups,
1235 .release = disk_release,
1236 .devnode = block_devnode,
1239 #ifdef CONFIG_PROC_FS
1241 * aggregate disk stat collector. Uses the same stats that the sysfs
1242 * entries do, above, but makes them available through one seq_file.
1244 * The output looks suspiciously like /proc/partitions with a bunch of
1247 static int diskstats_show(struct seq_file *seqf, void *v)
1249 struct gendisk *gp = v;
1250 struct disk_part_iter piter;
1251 struct block_device *hd;
1252 char buf[BDEVNAME_SIZE];
1253 unsigned int inflight;
1254 struct disk_stats stat;
1257 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1258 seq_puts(seqf, "major minor name"
1259 " rio rmerge rsect ruse wio wmerge "
1260 "wsect wuse running use aveq"
1264 disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
1265 while ((hd = disk_part_iter_next(&piter))) {
1266 part_stat_read_all(hd, &stat);
1267 if (queue_is_mq(gp->queue))
1268 inflight = blk_mq_in_flight(gp->queue, hd);
1270 inflight = part_in_flight(hd);
1272 seq_printf(seqf, "%4d %7d %s "
1279 MAJOR(hd->bd_dev), MINOR(hd->bd_dev),
1280 disk_name(gp, hd->bd_partno, buf),
1281 stat.ios[STAT_READ],
1282 stat.merges[STAT_READ],
1283 stat.sectors[STAT_READ],
1284 (unsigned int)div_u64(stat.nsecs[STAT_READ],
1286 stat.ios[STAT_WRITE],
1287 stat.merges[STAT_WRITE],
1288 stat.sectors[STAT_WRITE],
1289 (unsigned int)div_u64(stat.nsecs[STAT_WRITE],
1292 jiffies_to_msecs(stat.io_ticks),
1293 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1294 stat.nsecs[STAT_WRITE] +
1295 stat.nsecs[STAT_DISCARD] +
1296 stat.nsecs[STAT_FLUSH],
1298 stat.ios[STAT_DISCARD],
1299 stat.merges[STAT_DISCARD],
1300 stat.sectors[STAT_DISCARD],
1301 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD],
1303 stat.ios[STAT_FLUSH],
1304 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH],
1308 disk_part_iter_exit(&piter);
1313 static const struct seq_operations diskstats_op = {
1314 .start = disk_seqf_start,
1315 .next = disk_seqf_next,
1316 .stop = disk_seqf_stop,
1317 .show = diskstats_show
1320 static int __init proc_genhd_init(void)
1322 proc_create_seq("diskstats", 0, NULL, &diskstats_op);
1323 proc_create_seq("partitions", 0, NULL, &partitions_op);
1326 module_init(proc_genhd_init);
1327 #endif /* CONFIG_PROC_FS */
1329 dev_t blk_lookup_devt(const char *name, int partno)
1331 dev_t devt = MKDEV(0, 0);
1332 struct class_dev_iter iter;
1335 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
1336 while ((dev = class_dev_iter_next(&iter))) {
1337 struct gendisk *disk = dev_to_disk(dev);
1338 struct block_device *part;
1340 if (strcmp(dev_name(dev), name))
1343 if (partno < disk->minors) {
1344 /* We need to return the right devno, even
1345 * if the partition doesn't exist yet.
1347 devt = MKDEV(MAJOR(dev->devt),
1348 MINOR(dev->devt) + partno);
1351 part = bdget_disk(disk, partno);
1353 devt = part->bd_dev;
1358 class_dev_iter_exit(&iter);
1362 struct gendisk *__alloc_disk_node(int minors, int node_id)
1364 struct gendisk *disk;
1366 if (minors > DISK_MAX_PARTS) {
1368 "block: can't allocate more than %d partitions\n",
1370 minors = DISK_MAX_PARTS;
1373 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
1377 disk->part0 = bdev_alloc(disk, 0);
1381 disk->node_id = node_id;
1382 xa_init(&disk->part_tbl);
1383 if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL))
1384 goto out_destroy_part_tbl;
1386 disk->minors = minors;
1387 rand_initialize_disk(disk);
1388 disk_to_dev(disk)->class = &block_class;
1389 disk_to_dev(disk)->type = &disk_type;
1390 device_initialize(disk_to_dev(disk));
1393 out_destroy_part_tbl:
1394 xa_destroy(&disk->part_tbl);
1400 EXPORT_SYMBOL(__alloc_disk_node);
1403 * put_disk - decrements the gendisk refcount
1404 * @disk: the struct gendisk to decrement the refcount for
1406 * This decrements the refcount for the struct gendisk. When this reaches 0
1407 * we'll have disk_release() called.
1409 * Context: Any context, but the last reference must not be dropped from
1412 void put_disk(struct gendisk *disk)
1415 put_device(disk_to_dev(disk));
1417 EXPORT_SYMBOL(put_disk);
1419 static void set_disk_ro_uevent(struct gendisk *gd, int ro)
1421 char event[] = "DISK_RO=1";
1422 char *envp[] = { event, NULL };
1426 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
1430 * set_disk_ro - set a gendisk read-only
1431 * @disk: gendisk to operate on
1432 * @read_only: %true to set the disk read-only, %false set the disk read/write
1434 * This function is used to indicate whether a given disk device should have its
1435 * read-only flag set. set_disk_ro() is typically used by device drivers to
1436 * indicate whether the underlying physical device is write-protected.
1438 void set_disk_ro(struct gendisk *disk, bool read_only)
1441 if (test_and_set_bit(GD_READ_ONLY, &disk->state))
1444 if (!test_and_clear_bit(GD_READ_ONLY, &disk->state))
1447 set_disk_ro_uevent(disk, read_only);
1449 EXPORT_SYMBOL(set_disk_ro);
1451 int bdev_read_only(struct block_device *bdev)
1453 return bdev->bd_read_only || get_disk_ro(bdev->bd_disk);
1455 EXPORT_SYMBOL(bdev_read_only);
1458 * Disk events - monitor disk events like media change and eject request.
1460 struct disk_events {
1461 struct list_head node; /* all disk_event's */
1462 struct gendisk *disk; /* the associated disk */
1465 struct mutex block_mutex; /* protects blocking */
1466 int block; /* event blocking depth */
1467 unsigned int pending; /* events already sent out */
1468 unsigned int clearing; /* events being cleared */
1470 long poll_msecs; /* interval, -1 for default */
1471 struct delayed_work dwork;
1474 static const char *disk_events_strs[] = {
1475 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
1476 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
1479 static char *disk_uevents[] = {
1480 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
1481 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
1484 /* list of all disk_events */
1485 static DEFINE_MUTEX(disk_events_mutex);
1486 static LIST_HEAD(disk_events);
1488 /* disable in-kernel polling by default */
1489 static unsigned long disk_events_dfl_poll_msecs;
1491 static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
1493 struct disk_events *ev = disk->ev;
1494 long intv_msecs = 0;
1497 * If device-specific poll interval is set, always use it. If
1498 * the default is being used, poll if the POLL flag is set.
1500 if (ev->poll_msecs >= 0)
1501 intv_msecs = ev->poll_msecs;
1502 else if (disk->event_flags & DISK_EVENT_FLAG_POLL)
1503 intv_msecs = disk_events_dfl_poll_msecs;
1505 return msecs_to_jiffies(intv_msecs);
1509 * disk_block_events - block and flush disk event checking
1510 * @disk: disk to block events for
1512 * On return from this function, it is guaranteed that event checking
1513 * isn't in progress and won't happen until unblocked by
1514 * disk_unblock_events(). Events blocking is counted and the actual
1515 * unblocking happens after the matching number of unblocks are done.
1517 * Note that this intentionally does not block event checking from
1518 * disk_clear_events().
1523 void disk_block_events(struct gendisk *disk)
1525 struct disk_events *ev = disk->ev;
1526 unsigned long flags;
1533 * Outer mutex ensures that the first blocker completes canceling
1534 * the event work before further blockers are allowed to finish.
1536 mutex_lock(&ev->block_mutex);
1538 spin_lock_irqsave(&ev->lock, flags);
1539 cancel = !ev->block++;
1540 spin_unlock_irqrestore(&ev->lock, flags);
1543 cancel_delayed_work_sync(&disk->ev->dwork);
1545 mutex_unlock(&ev->block_mutex);
1548 static void __disk_unblock_events(struct gendisk *disk, bool check_now)
1550 struct disk_events *ev = disk->ev;
1552 unsigned long flags;
1554 spin_lock_irqsave(&ev->lock, flags);
1556 if (WARN_ON_ONCE(ev->block <= 0))
1562 intv = disk_events_poll_jiffies(disk);
1564 queue_delayed_work(system_freezable_power_efficient_wq,
1567 queue_delayed_work(system_freezable_power_efficient_wq,
1570 spin_unlock_irqrestore(&ev->lock, flags);
1574 * disk_unblock_events - unblock disk event checking
1575 * @disk: disk to unblock events for
1577 * Undo disk_block_events(). When the block count reaches zero, it
1578 * starts events polling if configured.
1581 * Don't care. Safe to call from irq context.
1583 void disk_unblock_events(struct gendisk *disk)
1586 __disk_unblock_events(disk, false);
1590 * disk_flush_events - schedule immediate event checking and flushing
1591 * @disk: disk to check and flush events for
1592 * @mask: events to flush
1594 * Schedule immediate event checking on @disk if not blocked. Events in
1595 * @mask are scheduled to be cleared from the driver. Note that this
1596 * doesn't clear the events from @disk->ev.
1599 * If @mask is non-zero must be called with bdev->bd_mutex held.
1601 void disk_flush_events(struct gendisk *disk, unsigned int mask)
1603 struct disk_events *ev = disk->ev;
1608 spin_lock_irq(&ev->lock);
1609 ev->clearing |= mask;
1611 mod_delayed_work(system_freezable_power_efficient_wq,
1613 spin_unlock_irq(&ev->lock);
1617 * disk_clear_events - synchronously check, clear and return pending events
1618 * @disk: disk to fetch and clear events from
1619 * @mask: mask of events to be fetched and cleared
1621 * Disk events are synchronously checked and pending events in @mask
1622 * are cleared and returned. This ignores the block count.
1627 static unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
1629 struct disk_events *ev = disk->ev;
1630 unsigned int pending;
1631 unsigned int clearing = mask;
1636 disk_block_events(disk);
1639 * store the union of mask and ev->clearing on the stack so that the
1640 * race with disk_flush_events does not cause ambiguity (ev->clearing
1641 * can still be modified even if events are blocked).
1643 spin_lock_irq(&ev->lock);
1644 clearing |= ev->clearing;
1646 spin_unlock_irq(&ev->lock);
1648 disk_check_events(ev, &clearing);
1650 * if ev->clearing is not 0, the disk_flush_events got called in the
1651 * middle of this function, so we want to run the workfn without delay.
1653 __disk_unblock_events(disk, ev->clearing ? true : false);
1655 /* then, fetch and clear pending events */
1656 spin_lock_irq(&ev->lock);
1657 pending = ev->pending & mask;
1658 ev->pending &= ~mask;
1659 spin_unlock_irq(&ev->lock);
1660 WARN_ON_ONCE(clearing & mask);
1666 * bdev_check_media_change - check if a removable media has been changed
1667 * @bdev: block device to check
1669 * Check whether a removable media has been changed, and attempt to free all
1670 * dentries and inodes and invalidates all block device page cache entries in
1673 * Returns %true if the block device changed, or %false if not.
1675 bool bdev_check_media_change(struct block_device *bdev)
1677 unsigned int events;
1679 events = disk_clear_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE |
1680 DISK_EVENT_EJECT_REQUEST);
1681 if (!(events & DISK_EVENT_MEDIA_CHANGE))
1684 if (__invalidate_device(bdev, true))
1685 pr_warn("VFS: busy inodes on changed media %s\n",
1686 bdev->bd_disk->disk_name);
1687 set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
1690 EXPORT_SYMBOL(bdev_check_media_change);
1693 * Separate this part out so that a different pointer for clearing_ptr can be
1694 * passed in for disk_clear_events.
1696 static void disk_events_workfn(struct work_struct *work)
1698 struct delayed_work *dwork = to_delayed_work(work);
1699 struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
1701 disk_check_events(ev, &ev->clearing);
1704 static void disk_check_events(struct disk_events *ev,
1705 unsigned int *clearing_ptr)
1707 struct gendisk *disk = ev->disk;
1708 char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
1709 unsigned int clearing = *clearing_ptr;
1710 unsigned int events;
1712 int nr_events = 0, i;
1715 events = disk->fops->check_events(disk, clearing);
1717 /* accumulate pending events and schedule next poll if necessary */
1718 spin_lock_irq(&ev->lock);
1720 events &= ~ev->pending;
1721 ev->pending |= events;
1722 *clearing_ptr &= ~clearing;
1724 intv = disk_events_poll_jiffies(disk);
1725 if (!ev->block && intv)
1726 queue_delayed_work(system_freezable_power_efficient_wq,
1729 spin_unlock_irq(&ev->lock);
1732 * Tell userland about new events. Only the events listed in
1733 * @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT
1734 * is set. Otherwise, events are processed internally but never
1735 * get reported to userland.
1737 for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
1738 if ((events & disk->events & (1 << i)) &&
1739 (disk->event_flags & DISK_EVENT_FLAG_UEVENT))
1740 envp[nr_events++] = disk_uevents[i];
1743 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
1747 * A disk events enabled device has the following sysfs nodes under
1748 * its /sys/block/X/ directory.
1750 * events : list of all supported events
1751 * events_async : list of events which can be detected w/o polling
1752 * (always empty, only for backwards compatibility)
1753 * events_poll_msecs : polling interval, 0: disable, -1: system default
1755 static ssize_t __disk_events_show(unsigned int events, char *buf)
1757 const char *delim = "";
1761 for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
1762 if (events & (1 << i)) {
1763 pos += sprintf(buf + pos, "%s%s",
1764 delim, disk_events_strs[i]);
1768 pos += sprintf(buf + pos, "\n");
1772 static ssize_t disk_events_show(struct device *dev,
1773 struct device_attribute *attr, char *buf)
1775 struct gendisk *disk = dev_to_disk(dev);
1777 if (!(disk->event_flags & DISK_EVENT_FLAG_UEVENT))
1780 return __disk_events_show(disk->events, buf);
1783 static ssize_t disk_events_async_show(struct device *dev,
1784 struct device_attribute *attr, char *buf)
1789 static ssize_t disk_events_poll_msecs_show(struct device *dev,
1790 struct device_attribute *attr,
1793 struct gendisk *disk = dev_to_disk(dev);
1796 return sprintf(buf, "-1\n");
1798 return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
1801 static ssize_t disk_events_poll_msecs_store(struct device *dev,
1802 struct device_attribute *attr,
1803 const char *buf, size_t count)
1805 struct gendisk *disk = dev_to_disk(dev);
1808 if (!count || !sscanf(buf, "%ld", &intv))
1811 if (intv < 0 && intv != -1)
1817 disk_block_events(disk);
1818 disk->ev->poll_msecs = intv;
1819 __disk_unblock_events(disk, true);
1824 static const DEVICE_ATTR(events, 0444, disk_events_show, NULL);
1825 static const DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL);
1826 static const DEVICE_ATTR(events_poll_msecs, 0644,
1827 disk_events_poll_msecs_show,
1828 disk_events_poll_msecs_store);
1830 static const struct attribute *disk_events_attrs[] = {
1831 &dev_attr_events.attr,
1832 &dev_attr_events_async.attr,
1833 &dev_attr_events_poll_msecs.attr,
1838 * The default polling interval can be specified by the kernel
1839 * parameter block.events_dfl_poll_msecs which defaults to 0
1840 * (disable). This can also be modified runtime by writing to
1841 * /sys/module/block/parameters/events_dfl_poll_msecs.
1843 static int disk_events_set_dfl_poll_msecs(const char *val,
1844 const struct kernel_param *kp)
1846 struct disk_events *ev;
1849 ret = param_set_ulong(val, kp);
1853 mutex_lock(&disk_events_mutex);
1855 list_for_each_entry(ev, &disk_events, node)
1856 disk_flush_events(ev->disk, 0);
1858 mutex_unlock(&disk_events_mutex);
1863 static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
1864 .set = disk_events_set_dfl_poll_msecs,
1865 .get = param_get_ulong,
1868 #undef MODULE_PARAM_PREFIX
1869 #define MODULE_PARAM_PREFIX "block."
1871 module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
1872 &disk_events_dfl_poll_msecs, 0644);
1875 * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
1877 static void disk_alloc_events(struct gendisk *disk)
1879 struct disk_events *ev;
1881 if (!disk->fops->check_events || !disk->events)
1884 ev = kzalloc(sizeof(*ev), GFP_KERNEL);
1886 pr_warn("%s: failed to initialize events\n", disk->disk_name);
1890 INIT_LIST_HEAD(&ev->node);
1892 spin_lock_init(&ev->lock);
1893 mutex_init(&ev->block_mutex);
1895 ev->poll_msecs = -1;
1896 INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
1901 static void disk_add_events(struct gendisk *disk)
1903 /* FIXME: error handling */
1904 if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
1905 pr_warn("%s: failed to create sysfs files for events\n",
1911 mutex_lock(&disk_events_mutex);
1912 list_add_tail(&disk->ev->node, &disk_events);
1913 mutex_unlock(&disk_events_mutex);
1916 * Block count is initialized to 1 and the following initial
1917 * unblock kicks it into action.
1919 __disk_unblock_events(disk, true);
1922 static void disk_del_events(struct gendisk *disk)
1925 disk_block_events(disk);
1927 mutex_lock(&disk_events_mutex);
1928 list_del_init(&disk->ev->node);
1929 mutex_unlock(&disk_events_mutex);
1932 sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
1935 static void disk_release_events(struct gendisk *disk)
1937 /* the block count should be 1 from disk_del_events() */
1938 WARN_ON_ONCE(disk->ev && disk->ev->block != 1);