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 /* for extended dynamic devt allocation, currently only one major is used */
33 #define NR_EXT_DEVT (1 << MINORBITS)
34 static DEFINE_IDA(ext_devt_ida);
36 static void disk_check_events(struct disk_events *ev,
37 unsigned int *clearing_ptr);
38 static void disk_alloc_events(struct gendisk *disk);
39 static void disk_add_events(struct gendisk *disk);
40 static void disk_del_events(struct gendisk *disk);
41 static void disk_release_events(struct gendisk *disk);
43 void set_capacity(struct gendisk *disk, sector_t sectors)
45 struct block_device *bdev = disk->part0;
47 spin_lock(&bdev->bd_size_lock);
48 i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
49 spin_unlock(&bdev->bd_size_lock);
51 EXPORT_SYMBOL(set_capacity);
54 * Set disk capacity and notify if the size is not currently zero and will not
55 * be set to zero. Returns true if a uevent was sent, otherwise false.
57 bool set_capacity_and_notify(struct gendisk *disk, sector_t size)
59 sector_t capacity = get_capacity(disk);
60 char *envp[] = { "RESIZE=1", NULL };
62 set_capacity(disk, size);
65 * Only print a message and send a uevent if the gendisk is user visible
66 * and alive. This avoids spamming the log and udev when setting the
67 * initial capacity during probing.
69 if (size == capacity ||
70 (disk->flags & (GENHD_FL_UP | GENHD_FL_HIDDEN)) != GENHD_FL_UP)
73 pr_info("%s: detected capacity change from %lld to %lld\n",
74 disk->disk_name, capacity, size);
77 * Historically we did not send a uevent for changes to/from an empty
80 if (!capacity || !size)
82 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
85 EXPORT_SYMBOL_GPL(set_capacity_and_notify);
88 * Format the device name of the indicated disk into the supplied buffer and
89 * return a pointer to that same buffer for convenience.
91 char *disk_name(struct gendisk *hd, int partno, char *buf)
94 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
95 else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
96 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
98 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
103 const char *bdevname(struct block_device *bdev, char *buf)
105 return disk_name(bdev->bd_disk, bdev->bd_partno, buf);
107 EXPORT_SYMBOL(bdevname);
109 static void part_stat_read_all(struct block_device *part,
110 struct disk_stats *stat)
114 memset(stat, 0, sizeof(struct disk_stats));
115 for_each_possible_cpu(cpu) {
116 struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu);
119 for (group = 0; group < NR_STAT_GROUPS; group++) {
120 stat->nsecs[group] += ptr->nsecs[group];
121 stat->sectors[group] += ptr->sectors[group];
122 stat->ios[group] += ptr->ios[group];
123 stat->merges[group] += ptr->merges[group];
126 stat->io_ticks += ptr->io_ticks;
130 static unsigned int part_in_flight(struct block_device *part)
132 unsigned int inflight = 0;
135 for_each_possible_cpu(cpu) {
136 inflight += part_stat_local_read_cpu(part, in_flight[0], cpu) +
137 part_stat_local_read_cpu(part, in_flight[1], cpu);
139 if ((int)inflight < 0)
145 static void part_in_flight_rw(struct block_device *part,
146 unsigned int inflight[2])
152 for_each_possible_cpu(cpu) {
153 inflight[0] += part_stat_local_read_cpu(part, in_flight[0], cpu);
154 inflight[1] += part_stat_local_read_cpu(part, in_flight[1], cpu);
156 if ((int)inflight[0] < 0)
158 if ((int)inflight[1] < 0)
163 * Can be deleted altogether. Later.
166 #define BLKDEV_MAJOR_HASH_SIZE 255
167 static struct blk_major_name {
168 struct blk_major_name *next;
171 void (*probe)(dev_t devt);
172 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
173 static DEFINE_MUTEX(major_names_lock);
175 /* index in the above - for now: assume no multimajor ranges */
176 static inline int major_to_index(unsigned major)
178 return major % BLKDEV_MAJOR_HASH_SIZE;
181 #ifdef CONFIG_PROC_FS
182 void blkdev_show(struct seq_file *seqf, off_t offset)
184 struct blk_major_name *dp;
186 mutex_lock(&major_names_lock);
187 for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next)
188 if (dp->major == offset)
189 seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
190 mutex_unlock(&major_names_lock);
192 #endif /* CONFIG_PROC_FS */
195 * __register_blkdev - register a new block device
197 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
198 * @major = 0, try to allocate any unused major number.
199 * @name: the name of the new block device as a zero terminated string
200 * @probe: allback that is called on access to any minor number of @major
202 * The @name must be unique within the system.
204 * The return value depends on the @major input parameter:
206 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
207 * then the function returns zero on success, or a negative error code
208 * - if any unused major number was requested with @major = 0 parameter
209 * then the return value is the allocated major number in range
210 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
212 * See Documentation/admin-guide/devices.txt for the list of allocated
215 * Use register_blkdev instead for any new code.
217 int __register_blkdev(unsigned int major, const char *name,
218 void (*probe)(dev_t devt))
220 struct blk_major_name **n, *p;
223 mutex_lock(&major_names_lock);
227 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
228 if (major_names[index] == NULL)
233 printk("%s: failed to get major for %s\n",
242 if (major >= BLKDEV_MAJOR_MAX) {
243 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
244 __func__, major, BLKDEV_MAJOR_MAX-1, name);
250 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
258 strlcpy(p->name, name, sizeof(p->name));
260 index = major_to_index(major);
262 for (n = &major_names[index]; *n; n = &(*n)->next) {
263 if ((*n)->major == major)
272 printk("register_blkdev: cannot get major %u for %s\n",
277 mutex_unlock(&major_names_lock);
280 EXPORT_SYMBOL(__register_blkdev);
282 void unregister_blkdev(unsigned int major, const char *name)
284 struct blk_major_name **n;
285 struct blk_major_name *p = NULL;
286 int index = major_to_index(major);
288 mutex_lock(&major_names_lock);
289 for (n = &major_names[index]; *n; n = &(*n)->next)
290 if ((*n)->major == major)
292 if (!*n || strcmp((*n)->name, name)) {
298 mutex_unlock(&major_names_lock);
302 EXPORT_SYMBOL(unregister_blkdev);
305 * blk_mangle_minor - scatter minor numbers apart
306 * @minor: minor number to mangle
308 * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
309 * is enabled. Mangling twice gives the original value.
317 static int blk_mangle_minor(int minor)
319 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
322 for (i = 0; i < MINORBITS / 2; i++) {
323 int low = minor & (1 << i);
324 int high = minor & (1 << (MINORBITS - 1 - i));
325 int distance = MINORBITS - 1 - 2 * i;
327 minor ^= low | high; /* clear both bits */
328 low <<= distance; /* swap the positions */
330 minor |= low | high; /* and set */
337 * blk_alloc_devt - allocate a dev_t for a block device
338 * @bdev: block device to allocate dev_t for
339 * @devt: out parameter for resulting dev_t
341 * Allocate a dev_t for block device.
344 * 0 on success, allocated dev_t is returned in *@devt. -errno on
350 int blk_alloc_devt(struct block_device *bdev, dev_t *devt)
352 struct gendisk *disk = bdev->bd_disk;
355 /* in consecutive minor range? */
356 if (bdev->bd_partno < disk->minors) {
357 *devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
361 idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT, GFP_KERNEL);
363 return idx == -ENOSPC ? -EBUSY : idx;
365 *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
370 * blk_free_devt - free a dev_t
371 * @devt: dev_t to free
373 * Free @devt which was allocated using blk_alloc_devt().
378 void blk_free_devt(dev_t devt)
380 if (MAJOR(devt) == BLOCK_EXT_MAJOR)
381 ida_free(&ext_devt_ida, blk_mangle_minor(MINOR(devt)));
384 static char *bdevt_str(dev_t devt, char *buf)
386 if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
387 char tbuf[BDEVT_SIZE];
388 snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
389 snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
391 snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
396 void disk_uevent(struct gendisk *disk, enum kobject_action action)
398 struct block_device *part;
402 xa_for_each(&disk->part_tbl, idx, part) {
403 if (bdev_is_partition(part) && !bdev_nr_sectors(part))
409 kobject_uevent(bdev_kobj(part), action);
415 EXPORT_SYMBOL_GPL(disk_uevent);
417 static void disk_scan_partitions(struct gendisk *disk)
419 struct block_device *bdev;
421 if (!get_capacity(disk) || !disk_part_scan_enabled(disk))
424 set_bit(GD_NEED_PART_SCAN, &disk->state);
425 bdev = blkdev_get_by_dev(disk_devt(disk), FMODE_READ, NULL);
427 blkdev_put(bdev, FMODE_READ);
430 static void register_disk(struct device *parent, struct gendisk *disk,
431 const struct attribute_group **groups)
433 struct device *ddev = disk_to_dev(disk);
436 ddev->parent = parent;
438 dev_set_name(ddev, "%s", disk->disk_name);
440 /* delay uevents, until we scanned partition table */
441 dev_set_uevent_suppress(ddev, 1);
444 WARN_ON(ddev->groups);
445 ddev->groups = groups;
447 if (device_add(ddev))
449 if (!sysfs_deprecated) {
450 err = sysfs_create_link(block_depr, &ddev->kobj,
451 kobject_name(&ddev->kobj));
459 * avoid probable deadlock caused by allocating memory with
460 * GFP_KERNEL in runtime_resume callback of its all ancestor
463 pm_runtime_set_memalloc_noio(ddev, true);
465 disk->part0->bd_holder_dir =
466 kobject_create_and_add("holders", &ddev->kobj);
467 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
469 if (disk->flags & GENHD_FL_HIDDEN)
472 disk_scan_partitions(disk);
474 /* announce the disk and partitions after all partitions are created */
475 dev_set_uevent_suppress(ddev, 0);
476 disk_uevent(disk, KOBJ_ADD);
478 if (disk->queue->backing_dev_info->dev) {
479 err = sysfs_create_link(&ddev->kobj,
480 &disk->queue->backing_dev_info->dev->kobj,
487 * __device_add_disk - add disk information to kernel list
488 * @parent: parent device for the disk
489 * @disk: per-device partitioning information
490 * @groups: Additional per-device sysfs groups
491 * @register_queue: register the queue if set to true
493 * This function registers the partitioning information in @disk
496 * FIXME: error handling
498 static void __device_add_disk(struct device *parent, struct gendisk *disk,
499 const struct attribute_group **groups,
506 * The disk queue should now be all set with enough information about
507 * the device for the elevator code to pick an adequate default
508 * elevator if one is needed, that is, for devices requesting queue
512 elevator_init_mq(disk->queue);
514 /* minors == 0 indicates to use ext devt from part0 and should
515 * be accompanied with EXT_DEVT flag. Make sure all
516 * parameters make sense.
518 WARN_ON(disk->minors && !(disk->major || disk->first_minor));
519 WARN_ON(!disk->minors &&
520 !(disk->flags & (GENHD_FL_EXT_DEVT | GENHD_FL_HIDDEN)));
522 disk->flags |= GENHD_FL_UP;
524 retval = blk_alloc_devt(disk->part0, &devt);
529 disk->major = MAJOR(devt);
530 disk->first_minor = MINOR(devt);
532 disk_alloc_events(disk);
534 if (disk->flags & GENHD_FL_HIDDEN) {
536 * Don't let hidden disks show up in /proc/partitions,
537 * and don't bother scanning for partitions either.
539 disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
540 disk->flags |= GENHD_FL_NO_PART_SCAN;
542 struct backing_dev_info *bdi = disk->queue->backing_dev_info;
543 struct device *dev = disk_to_dev(disk);
546 /* Register BDI before referencing it from bdev */
548 ret = bdi_register(bdi, "%u:%u", MAJOR(devt), MINOR(devt));
550 bdi_set_owner(bdi, dev);
551 bdev_add(disk->part0, devt);
553 register_disk(parent, disk, groups);
555 blk_register_queue(disk);
558 * Take an extra ref on queue which will be put on disk_release()
559 * so that it sticks around as long as @disk is there.
561 WARN_ON_ONCE(!blk_get_queue(disk->queue));
563 disk_add_events(disk);
564 blk_integrity_add(disk);
567 void device_add_disk(struct device *parent, struct gendisk *disk,
568 const struct attribute_group **groups)
571 __device_add_disk(parent, disk, groups, true);
573 EXPORT_SYMBOL(device_add_disk);
575 void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk)
577 __device_add_disk(parent, disk, NULL, false);
579 EXPORT_SYMBOL(device_add_disk_no_queue_reg);
582 * del_gendisk - remove the gendisk
583 * @disk: the struct gendisk to remove
585 * Removes the gendisk and all its associated resources. This deletes the
586 * partitions associated with the gendisk, and unregisters the associated
589 * This is the counter to the respective __device_add_disk() call.
591 * The final removal of the struct gendisk happens when its refcount reaches 0
592 * with put_disk(), which should be called after del_gendisk(), if
593 * __device_add_disk() was used.
595 * Drivers exist which depend on the release of the gendisk to be synchronous,
596 * it should not be deferred.
600 void del_gendisk(struct gendisk *disk)
604 if (WARN_ON_ONCE(!disk->queue))
607 blk_integrity_del(disk);
608 disk_del_events(disk);
610 mutex_lock(&disk->part0->bd_mutex);
611 disk->flags &= ~GENHD_FL_UP;
612 blk_drop_partitions(disk);
613 mutex_unlock(&disk->part0->bd_mutex);
615 fsync_bdev(disk->part0);
616 __invalidate_device(disk->part0, true);
619 * Unhash the bdev inode for this device so that it can't be looked
620 * up any more even if openers still hold references to it.
622 remove_inode_hash(disk->part0->bd_inode);
624 set_capacity(disk, 0);
626 if (!(disk->flags & GENHD_FL_HIDDEN)) {
627 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
630 * Unregister bdi before releasing device numbers (as they can
631 * get reused and we'd get clashes in sysfs).
633 bdi_unregister(disk->queue->backing_dev_info);
636 blk_unregister_queue(disk);
638 kobject_put(disk->part0->bd_holder_dir);
639 kobject_put(disk->slave_dir);
641 part_stat_set_all(disk->part0, 0);
642 disk->part0->bd_stamp = 0;
643 if (!sysfs_deprecated)
644 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
645 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
646 device_del(disk_to_dev(disk));
648 EXPORT_SYMBOL(del_gendisk);
650 /* sysfs access to bad-blocks list. */
651 static ssize_t disk_badblocks_show(struct device *dev,
652 struct device_attribute *attr,
655 struct gendisk *disk = dev_to_disk(dev);
658 return sprintf(page, "\n");
660 return badblocks_show(disk->bb, page, 0);
663 static ssize_t disk_badblocks_store(struct device *dev,
664 struct device_attribute *attr,
665 const char *page, size_t len)
667 struct gendisk *disk = dev_to_disk(dev);
672 return badblocks_store(disk->bb, page, len, 0);
675 void blk_request_module(dev_t devt)
677 unsigned int major = MAJOR(devt);
678 struct blk_major_name **n;
680 mutex_lock(&major_names_lock);
681 for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) {
682 if ((*n)->major == major && (*n)->probe) {
684 mutex_unlock(&major_names_lock);
688 mutex_unlock(&major_names_lock);
690 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
691 /* Make old-style 2.4 aliases work */
692 request_module("block-major-%d", MAJOR(devt));
696 * bdget_disk - do bdget() by gendisk and partition number
697 * @disk: gendisk of interest
698 * @partno: partition number
700 * Find partition @partno from @disk, do bdget() on it.
706 * Resulting block_device on success, NULL on failure.
708 struct block_device *bdget_disk(struct gendisk *disk, int partno)
710 struct block_device *bdev = NULL;
713 bdev = xa_load(&disk->part_tbl, partno);
714 if (bdev && !bdgrab(bdev))
722 * print a full list of all partitions - intended for places where the root
723 * filesystem can't be mounted and thus to give the victim some idea of what
726 void __init printk_all_partitions(void)
728 struct class_dev_iter iter;
731 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
732 while ((dev = class_dev_iter_next(&iter))) {
733 struct gendisk *disk = dev_to_disk(dev);
734 struct block_device *part;
735 char name_buf[BDEVNAME_SIZE];
736 char devt_buf[BDEVT_SIZE];
740 * Don't show empty devices or things that have been
743 if (get_capacity(disk) == 0 ||
744 (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
748 * Note, unlike /proc/partitions, I am showing the numbers in
749 * hex - the same format as the root= option takes.
752 xa_for_each(&disk->part_tbl, idx, part) {
753 if (!bdev_nr_sectors(part))
755 printk("%s%s %10llu %s %s",
756 bdev_is_partition(part) ? " " : "",
757 bdevt_str(part->bd_dev, devt_buf),
758 bdev_nr_sectors(part) >> 1,
759 disk_name(disk, part->bd_partno, name_buf),
761 part->bd_meta_info->uuid : "");
762 if (bdev_is_partition(part))
764 else if (dev->parent && dev->parent->driver)
765 printk(" driver: %s\n",
766 dev->parent->driver->name);
768 printk(" (driver?)\n");
772 class_dev_iter_exit(&iter);
775 #ifdef CONFIG_PROC_FS
777 static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
780 struct class_dev_iter *iter;
783 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
785 return ERR_PTR(-ENOMEM);
787 seqf->private = iter;
788 class_dev_iter_init(iter, &block_class, NULL, &disk_type);
790 dev = class_dev_iter_next(iter);
795 return dev_to_disk(dev);
798 static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
803 dev = class_dev_iter_next(seqf->private);
805 return dev_to_disk(dev);
810 static void disk_seqf_stop(struct seq_file *seqf, void *v)
812 struct class_dev_iter *iter = seqf->private;
814 /* stop is called even after start failed :-( */
816 class_dev_iter_exit(iter);
818 seqf->private = NULL;
822 static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
826 p = disk_seqf_start(seqf, pos);
827 if (!IS_ERR_OR_NULL(p) && !*pos)
828 seq_puts(seqf, "major minor #blocks name\n\n");
832 static int show_partition(struct seq_file *seqf, void *v)
834 struct gendisk *sgp = v;
835 struct block_device *part;
837 char buf[BDEVNAME_SIZE];
839 /* Don't show non-partitionable removeable devices or empty devices */
840 if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
841 (sgp->flags & GENHD_FL_REMOVABLE)))
843 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
847 xa_for_each(&sgp->part_tbl, idx, part) {
848 if (!bdev_nr_sectors(part))
850 seq_printf(seqf, "%4d %7d %10llu %s\n",
851 MAJOR(part->bd_dev), MINOR(part->bd_dev),
852 bdev_nr_sectors(part) >> 1,
853 disk_name(sgp, part->bd_partno, buf));
859 static const struct seq_operations partitions_op = {
860 .start = show_partition_start,
861 .next = disk_seqf_next,
862 .stop = disk_seqf_stop,
863 .show = show_partition
867 static int __init genhd_device_init(void)
871 block_class.dev_kobj = sysfs_dev_block_kobj;
872 error = class_register(&block_class);
877 register_blkdev(BLOCK_EXT_MAJOR, "blkext");
879 /* create top-level block dir */
880 if (!sysfs_deprecated)
881 block_depr = kobject_create_and_add("block", NULL);
885 subsys_initcall(genhd_device_init);
887 static ssize_t disk_range_show(struct device *dev,
888 struct device_attribute *attr, char *buf)
890 struct gendisk *disk = dev_to_disk(dev);
892 return sprintf(buf, "%d\n", disk->minors);
895 static ssize_t disk_ext_range_show(struct device *dev,
896 struct device_attribute *attr, char *buf)
898 struct gendisk *disk = dev_to_disk(dev);
900 return sprintf(buf, "%d\n", disk_max_parts(disk));
903 static ssize_t disk_removable_show(struct device *dev,
904 struct device_attribute *attr, char *buf)
906 struct gendisk *disk = dev_to_disk(dev);
908 return sprintf(buf, "%d\n",
909 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
912 static ssize_t disk_hidden_show(struct device *dev,
913 struct device_attribute *attr, char *buf)
915 struct gendisk *disk = dev_to_disk(dev);
917 return sprintf(buf, "%d\n",
918 (disk->flags & GENHD_FL_HIDDEN ? 1 : 0));
921 static ssize_t disk_ro_show(struct device *dev,
922 struct device_attribute *attr, char *buf)
924 struct gendisk *disk = dev_to_disk(dev);
926 return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
929 ssize_t part_size_show(struct device *dev,
930 struct device_attribute *attr, char *buf)
932 return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));
935 ssize_t part_stat_show(struct device *dev,
936 struct device_attribute *attr, char *buf)
938 struct block_device *bdev = dev_to_bdev(dev);
939 struct request_queue *q = bdev->bd_disk->queue;
940 struct disk_stats stat;
941 unsigned int inflight;
943 part_stat_read_all(bdev, &stat);
945 inflight = blk_mq_in_flight(q, bdev);
947 inflight = part_in_flight(bdev);
950 "%8lu %8lu %8llu %8u "
951 "%8lu %8lu %8llu %8u "
953 "%8lu %8lu %8llu %8u "
957 stat.merges[STAT_READ],
958 (unsigned long long)stat.sectors[STAT_READ],
959 (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC),
960 stat.ios[STAT_WRITE],
961 stat.merges[STAT_WRITE],
962 (unsigned long long)stat.sectors[STAT_WRITE],
963 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC),
965 jiffies_to_msecs(stat.io_ticks),
966 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
967 stat.nsecs[STAT_WRITE] +
968 stat.nsecs[STAT_DISCARD] +
969 stat.nsecs[STAT_FLUSH],
971 stat.ios[STAT_DISCARD],
972 stat.merges[STAT_DISCARD],
973 (unsigned long long)stat.sectors[STAT_DISCARD],
974 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC),
975 stat.ios[STAT_FLUSH],
976 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC));
979 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
982 struct block_device *bdev = dev_to_bdev(dev);
983 struct request_queue *q = bdev->bd_disk->queue;
984 unsigned int inflight[2];
987 blk_mq_in_flight_rw(q, bdev, inflight);
989 part_in_flight_rw(bdev, inflight);
991 return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
994 static ssize_t disk_capability_show(struct device *dev,
995 struct device_attribute *attr, char *buf)
997 struct gendisk *disk = dev_to_disk(dev);
999 return sprintf(buf, "%x\n", disk->flags);
1002 static ssize_t disk_alignment_offset_show(struct device *dev,
1003 struct device_attribute *attr,
1006 struct gendisk *disk = dev_to_disk(dev);
1008 return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue));
1011 static ssize_t disk_discard_alignment_show(struct device *dev,
1012 struct device_attribute *attr,
1015 struct gendisk *disk = dev_to_disk(dev);
1017 return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
1020 static DEVICE_ATTR(range, 0444, disk_range_show, NULL);
1021 static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL);
1022 static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL);
1023 static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL);
1024 static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL);
1025 static DEVICE_ATTR(size, 0444, part_size_show, NULL);
1026 static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL);
1027 static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL);
1028 static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL);
1029 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
1030 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
1031 static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
1033 #ifdef CONFIG_FAIL_MAKE_REQUEST
1034 ssize_t part_fail_show(struct device *dev,
1035 struct device_attribute *attr, char *buf)
1037 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail);
1040 ssize_t part_fail_store(struct device *dev,
1041 struct device_attribute *attr,
1042 const char *buf, size_t count)
1046 if (count > 0 && sscanf(buf, "%d", &i) > 0)
1047 dev_to_bdev(dev)->bd_make_it_fail = i;
1052 static struct device_attribute dev_attr_fail =
1053 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
1054 #endif /* CONFIG_FAIL_MAKE_REQUEST */
1056 #ifdef CONFIG_FAIL_IO_TIMEOUT
1057 static struct device_attribute dev_attr_fail_timeout =
1058 __ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store);
1061 static struct attribute *disk_attrs[] = {
1062 &dev_attr_range.attr,
1063 &dev_attr_ext_range.attr,
1064 &dev_attr_removable.attr,
1065 &dev_attr_hidden.attr,
1067 &dev_attr_size.attr,
1068 &dev_attr_alignment_offset.attr,
1069 &dev_attr_discard_alignment.attr,
1070 &dev_attr_capability.attr,
1071 &dev_attr_stat.attr,
1072 &dev_attr_inflight.attr,
1073 &dev_attr_badblocks.attr,
1074 #ifdef CONFIG_FAIL_MAKE_REQUEST
1075 &dev_attr_fail.attr,
1077 #ifdef CONFIG_FAIL_IO_TIMEOUT
1078 &dev_attr_fail_timeout.attr,
1083 static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n)
1085 struct device *dev = container_of(kobj, typeof(*dev), kobj);
1086 struct gendisk *disk = dev_to_disk(dev);
1088 if (a == &dev_attr_badblocks.attr && !disk->bb)
1093 static struct attribute_group disk_attr_group = {
1094 .attrs = disk_attrs,
1095 .is_visible = disk_visible,
1098 static const struct attribute_group *disk_attr_groups[] = {
1104 * disk_release - releases all allocated resources of the gendisk
1105 * @dev: the device representing this disk
1107 * This function releases all allocated resources of the gendisk.
1109 * Drivers which used __device_add_disk() have a gendisk with a request_queue
1110 * assigned. Since the request_queue sits on top of the gendisk for these
1111 * drivers we also call blk_put_queue() for them, and we expect the
1112 * request_queue refcount to reach 0 at this point, and so the request_queue
1113 * will also be freed prior to the disk.
1115 * Context: can sleep
1117 static void disk_release(struct device *dev)
1119 struct gendisk *disk = dev_to_disk(dev);
1123 blk_free_devt(dev->devt);
1124 disk_release_events(disk);
1125 kfree(disk->random);
1126 xa_destroy(&disk->part_tbl);
1129 blk_put_queue(disk->queue);
1132 struct class block_class = {
1136 static char *block_devnode(struct device *dev, umode_t *mode,
1137 kuid_t *uid, kgid_t *gid)
1139 struct gendisk *disk = dev_to_disk(dev);
1141 if (disk->fops->devnode)
1142 return disk->fops->devnode(disk, mode);
1146 const struct device_type disk_type = {
1148 .groups = disk_attr_groups,
1149 .release = disk_release,
1150 .devnode = block_devnode,
1153 #ifdef CONFIG_PROC_FS
1155 * aggregate disk stat collector. Uses the same stats that the sysfs
1156 * entries do, above, but makes them available through one seq_file.
1158 * The output looks suspiciously like /proc/partitions with a bunch of
1161 static int diskstats_show(struct seq_file *seqf, void *v)
1163 struct gendisk *gp = v;
1164 struct block_device *hd;
1165 char buf[BDEVNAME_SIZE];
1166 unsigned int inflight;
1167 struct disk_stats stat;
1171 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1172 seq_puts(seqf, "major minor name"
1173 " rio rmerge rsect ruse wio wmerge "
1174 "wsect wuse running use aveq"
1179 xa_for_each(&gp->part_tbl, idx, hd) {
1180 if (bdev_is_partition(hd) && !bdev_nr_sectors(hd))
1182 part_stat_read_all(hd, &stat);
1183 if (queue_is_mq(gp->queue))
1184 inflight = blk_mq_in_flight(gp->queue, hd);
1186 inflight = part_in_flight(hd);
1188 seq_printf(seqf, "%4d %7d %s "
1195 MAJOR(hd->bd_dev), MINOR(hd->bd_dev),
1196 disk_name(gp, hd->bd_partno, buf),
1197 stat.ios[STAT_READ],
1198 stat.merges[STAT_READ],
1199 stat.sectors[STAT_READ],
1200 (unsigned int)div_u64(stat.nsecs[STAT_READ],
1202 stat.ios[STAT_WRITE],
1203 stat.merges[STAT_WRITE],
1204 stat.sectors[STAT_WRITE],
1205 (unsigned int)div_u64(stat.nsecs[STAT_WRITE],
1208 jiffies_to_msecs(stat.io_ticks),
1209 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1210 stat.nsecs[STAT_WRITE] +
1211 stat.nsecs[STAT_DISCARD] +
1212 stat.nsecs[STAT_FLUSH],
1214 stat.ios[STAT_DISCARD],
1215 stat.merges[STAT_DISCARD],
1216 stat.sectors[STAT_DISCARD],
1217 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD],
1219 stat.ios[STAT_FLUSH],
1220 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH],
1229 static const struct seq_operations diskstats_op = {
1230 .start = disk_seqf_start,
1231 .next = disk_seqf_next,
1232 .stop = disk_seqf_stop,
1233 .show = diskstats_show
1236 static int __init proc_genhd_init(void)
1238 proc_create_seq("diskstats", 0, NULL, &diskstats_op);
1239 proc_create_seq("partitions", 0, NULL, &partitions_op);
1242 module_init(proc_genhd_init);
1243 #endif /* CONFIG_PROC_FS */
1245 dev_t blk_lookup_devt(const char *name, int partno)
1247 dev_t devt = MKDEV(0, 0);
1248 struct class_dev_iter iter;
1251 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
1252 while ((dev = class_dev_iter_next(&iter))) {
1253 struct gendisk *disk = dev_to_disk(dev);
1254 struct block_device *part;
1256 if (strcmp(dev_name(dev), name))
1259 if (partno < disk->minors) {
1260 /* We need to return the right devno, even
1261 * if the partition doesn't exist yet.
1263 devt = MKDEV(MAJOR(dev->devt),
1264 MINOR(dev->devt) + partno);
1267 part = bdget_disk(disk, partno);
1269 devt = part->bd_dev;
1274 class_dev_iter_exit(&iter);
1278 struct gendisk *__alloc_disk_node(int minors, int node_id)
1280 struct gendisk *disk;
1282 if (minors > DISK_MAX_PARTS) {
1284 "block: can't allocate more than %d partitions\n",
1286 minors = DISK_MAX_PARTS;
1289 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
1293 disk->part0 = bdev_alloc(disk, 0);
1297 disk->node_id = node_id;
1298 xa_init(&disk->part_tbl);
1299 if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL))
1300 goto out_destroy_part_tbl;
1302 disk->minors = minors;
1303 rand_initialize_disk(disk);
1304 disk_to_dev(disk)->class = &block_class;
1305 disk_to_dev(disk)->type = &disk_type;
1306 device_initialize(disk_to_dev(disk));
1309 out_destroy_part_tbl:
1310 xa_destroy(&disk->part_tbl);
1316 EXPORT_SYMBOL(__alloc_disk_node);
1319 * put_disk - decrements the gendisk refcount
1320 * @disk: the struct gendisk to decrement the refcount for
1322 * This decrements the refcount for the struct gendisk. When this reaches 0
1323 * we'll have disk_release() called.
1325 * Context: Any context, but the last reference must not be dropped from
1328 void put_disk(struct gendisk *disk)
1331 put_device(disk_to_dev(disk));
1333 EXPORT_SYMBOL(put_disk);
1335 static void set_disk_ro_uevent(struct gendisk *gd, int ro)
1337 char event[] = "DISK_RO=1";
1338 char *envp[] = { event, NULL };
1342 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
1346 * set_disk_ro - set a gendisk read-only
1347 * @disk: gendisk to operate on
1348 * @read_only: %true to set the disk read-only, %false set the disk read/write
1350 * This function is used to indicate whether a given disk device should have its
1351 * read-only flag set. set_disk_ro() is typically used by device drivers to
1352 * indicate whether the underlying physical device is write-protected.
1354 void set_disk_ro(struct gendisk *disk, bool read_only)
1357 if (test_and_set_bit(GD_READ_ONLY, &disk->state))
1360 if (!test_and_clear_bit(GD_READ_ONLY, &disk->state))
1363 set_disk_ro_uevent(disk, read_only);
1365 EXPORT_SYMBOL(set_disk_ro);
1367 int bdev_read_only(struct block_device *bdev)
1369 return bdev->bd_read_only || get_disk_ro(bdev->bd_disk);
1371 EXPORT_SYMBOL(bdev_read_only);
1374 * Disk events - monitor disk events like media change and eject request.
1376 struct disk_events {
1377 struct list_head node; /* all disk_event's */
1378 struct gendisk *disk; /* the associated disk */
1381 struct mutex block_mutex; /* protects blocking */
1382 int block; /* event blocking depth */
1383 unsigned int pending; /* events already sent out */
1384 unsigned int clearing; /* events being cleared */
1386 long poll_msecs; /* interval, -1 for default */
1387 struct delayed_work dwork;
1390 static const char *disk_events_strs[] = {
1391 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
1392 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
1395 static char *disk_uevents[] = {
1396 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
1397 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
1400 /* list of all disk_events */
1401 static DEFINE_MUTEX(disk_events_mutex);
1402 static LIST_HEAD(disk_events);
1404 /* disable in-kernel polling by default */
1405 static unsigned long disk_events_dfl_poll_msecs;
1407 static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
1409 struct disk_events *ev = disk->ev;
1410 long intv_msecs = 0;
1413 * If device-specific poll interval is set, always use it. If
1414 * the default is being used, poll if the POLL flag is set.
1416 if (ev->poll_msecs >= 0)
1417 intv_msecs = ev->poll_msecs;
1418 else if (disk->event_flags & DISK_EVENT_FLAG_POLL)
1419 intv_msecs = disk_events_dfl_poll_msecs;
1421 return msecs_to_jiffies(intv_msecs);
1425 * disk_block_events - block and flush disk event checking
1426 * @disk: disk to block events for
1428 * On return from this function, it is guaranteed that event checking
1429 * isn't in progress and won't happen until unblocked by
1430 * disk_unblock_events(). Events blocking is counted and the actual
1431 * unblocking happens after the matching number of unblocks are done.
1433 * Note that this intentionally does not block event checking from
1434 * disk_clear_events().
1439 void disk_block_events(struct gendisk *disk)
1441 struct disk_events *ev = disk->ev;
1442 unsigned long flags;
1449 * Outer mutex ensures that the first blocker completes canceling
1450 * the event work before further blockers are allowed to finish.
1452 mutex_lock(&ev->block_mutex);
1454 spin_lock_irqsave(&ev->lock, flags);
1455 cancel = !ev->block++;
1456 spin_unlock_irqrestore(&ev->lock, flags);
1459 cancel_delayed_work_sync(&disk->ev->dwork);
1461 mutex_unlock(&ev->block_mutex);
1464 static void __disk_unblock_events(struct gendisk *disk, bool check_now)
1466 struct disk_events *ev = disk->ev;
1468 unsigned long flags;
1470 spin_lock_irqsave(&ev->lock, flags);
1472 if (WARN_ON_ONCE(ev->block <= 0))
1478 intv = disk_events_poll_jiffies(disk);
1480 queue_delayed_work(system_freezable_power_efficient_wq,
1483 queue_delayed_work(system_freezable_power_efficient_wq,
1486 spin_unlock_irqrestore(&ev->lock, flags);
1490 * disk_unblock_events - unblock disk event checking
1491 * @disk: disk to unblock events for
1493 * Undo disk_block_events(). When the block count reaches zero, it
1494 * starts events polling if configured.
1497 * Don't care. Safe to call from irq context.
1499 void disk_unblock_events(struct gendisk *disk)
1502 __disk_unblock_events(disk, false);
1506 * disk_flush_events - schedule immediate event checking and flushing
1507 * @disk: disk to check and flush events for
1508 * @mask: events to flush
1510 * Schedule immediate event checking on @disk if not blocked. Events in
1511 * @mask are scheduled to be cleared from the driver. Note that this
1512 * doesn't clear the events from @disk->ev.
1515 * If @mask is non-zero must be called with bdev->bd_mutex held.
1517 void disk_flush_events(struct gendisk *disk, unsigned int mask)
1519 struct disk_events *ev = disk->ev;
1524 spin_lock_irq(&ev->lock);
1525 ev->clearing |= mask;
1527 mod_delayed_work(system_freezable_power_efficient_wq,
1529 spin_unlock_irq(&ev->lock);
1533 * disk_clear_events - synchronously check, clear and return pending events
1534 * @disk: disk to fetch and clear events from
1535 * @mask: mask of events to be fetched and cleared
1537 * Disk events are synchronously checked and pending events in @mask
1538 * are cleared and returned. This ignores the block count.
1543 static unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
1545 struct disk_events *ev = disk->ev;
1546 unsigned int pending;
1547 unsigned int clearing = mask;
1552 disk_block_events(disk);
1555 * store the union of mask and ev->clearing on the stack so that the
1556 * race with disk_flush_events does not cause ambiguity (ev->clearing
1557 * can still be modified even if events are blocked).
1559 spin_lock_irq(&ev->lock);
1560 clearing |= ev->clearing;
1562 spin_unlock_irq(&ev->lock);
1564 disk_check_events(ev, &clearing);
1566 * if ev->clearing is not 0, the disk_flush_events got called in the
1567 * middle of this function, so we want to run the workfn without delay.
1569 __disk_unblock_events(disk, ev->clearing ? true : false);
1571 /* then, fetch and clear pending events */
1572 spin_lock_irq(&ev->lock);
1573 pending = ev->pending & mask;
1574 ev->pending &= ~mask;
1575 spin_unlock_irq(&ev->lock);
1576 WARN_ON_ONCE(clearing & mask);
1582 * bdev_check_media_change - check if a removable media has been changed
1583 * @bdev: block device to check
1585 * Check whether a removable media has been changed, and attempt to free all
1586 * dentries and inodes and invalidates all block device page cache entries in
1589 * Returns %true if the block device changed, or %false if not.
1591 bool bdev_check_media_change(struct block_device *bdev)
1593 unsigned int events;
1595 events = disk_clear_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE |
1596 DISK_EVENT_EJECT_REQUEST);
1597 if (!(events & DISK_EVENT_MEDIA_CHANGE))
1600 if (__invalidate_device(bdev, true))
1601 pr_warn("VFS: busy inodes on changed media %s\n",
1602 bdev->bd_disk->disk_name);
1603 set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
1606 EXPORT_SYMBOL(bdev_check_media_change);
1609 * Separate this part out so that a different pointer for clearing_ptr can be
1610 * passed in for disk_clear_events.
1612 static void disk_events_workfn(struct work_struct *work)
1614 struct delayed_work *dwork = to_delayed_work(work);
1615 struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
1617 disk_check_events(ev, &ev->clearing);
1620 static void disk_check_events(struct disk_events *ev,
1621 unsigned int *clearing_ptr)
1623 struct gendisk *disk = ev->disk;
1624 char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
1625 unsigned int clearing = *clearing_ptr;
1626 unsigned int events;
1628 int nr_events = 0, i;
1631 events = disk->fops->check_events(disk, clearing);
1633 /* accumulate pending events and schedule next poll if necessary */
1634 spin_lock_irq(&ev->lock);
1636 events &= ~ev->pending;
1637 ev->pending |= events;
1638 *clearing_ptr &= ~clearing;
1640 intv = disk_events_poll_jiffies(disk);
1641 if (!ev->block && intv)
1642 queue_delayed_work(system_freezable_power_efficient_wq,
1645 spin_unlock_irq(&ev->lock);
1648 * Tell userland about new events. Only the events listed in
1649 * @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT
1650 * is set. Otherwise, events are processed internally but never
1651 * get reported to userland.
1653 for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
1654 if ((events & disk->events & (1 << i)) &&
1655 (disk->event_flags & DISK_EVENT_FLAG_UEVENT))
1656 envp[nr_events++] = disk_uevents[i];
1659 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
1663 * A disk events enabled device has the following sysfs nodes under
1664 * its /sys/block/X/ directory.
1666 * events : list of all supported events
1667 * events_async : list of events which can be detected w/o polling
1668 * (always empty, only for backwards compatibility)
1669 * events_poll_msecs : polling interval, 0: disable, -1: system default
1671 static ssize_t __disk_events_show(unsigned int events, char *buf)
1673 const char *delim = "";
1677 for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
1678 if (events & (1 << i)) {
1679 pos += sprintf(buf + pos, "%s%s",
1680 delim, disk_events_strs[i]);
1684 pos += sprintf(buf + pos, "\n");
1688 static ssize_t disk_events_show(struct device *dev,
1689 struct device_attribute *attr, char *buf)
1691 struct gendisk *disk = dev_to_disk(dev);
1693 if (!(disk->event_flags & DISK_EVENT_FLAG_UEVENT))
1696 return __disk_events_show(disk->events, buf);
1699 static ssize_t disk_events_async_show(struct device *dev,
1700 struct device_attribute *attr, char *buf)
1705 static ssize_t disk_events_poll_msecs_show(struct device *dev,
1706 struct device_attribute *attr,
1709 struct gendisk *disk = dev_to_disk(dev);
1712 return sprintf(buf, "-1\n");
1714 return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
1717 static ssize_t disk_events_poll_msecs_store(struct device *dev,
1718 struct device_attribute *attr,
1719 const char *buf, size_t count)
1721 struct gendisk *disk = dev_to_disk(dev);
1724 if (!count || !sscanf(buf, "%ld", &intv))
1727 if (intv < 0 && intv != -1)
1733 disk_block_events(disk);
1734 disk->ev->poll_msecs = intv;
1735 __disk_unblock_events(disk, true);
1740 static const DEVICE_ATTR(events, 0444, disk_events_show, NULL);
1741 static const DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL);
1742 static const DEVICE_ATTR(events_poll_msecs, 0644,
1743 disk_events_poll_msecs_show,
1744 disk_events_poll_msecs_store);
1746 static const struct attribute *disk_events_attrs[] = {
1747 &dev_attr_events.attr,
1748 &dev_attr_events_async.attr,
1749 &dev_attr_events_poll_msecs.attr,
1754 * The default polling interval can be specified by the kernel
1755 * parameter block.events_dfl_poll_msecs which defaults to 0
1756 * (disable). This can also be modified runtime by writing to
1757 * /sys/module/block/parameters/events_dfl_poll_msecs.
1759 static int disk_events_set_dfl_poll_msecs(const char *val,
1760 const struct kernel_param *kp)
1762 struct disk_events *ev;
1765 ret = param_set_ulong(val, kp);
1769 mutex_lock(&disk_events_mutex);
1771 list_for_each_entry(ev, &disk_events, node)
1772 disk_flush_events(ev->disk, 0);
1774 mutex_unlock(&disk_events_mutex);
1779 static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
1780 .set = disk_events_set_dfl_poll_msecs,
1781 .get = param_get_ulong,
1784 #undef MODULE_PARAM_PREFIX
1785 #define MODULE_PARAM_PREFIX "block."
1787 module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
1788 &disk_events_dfl_poll_msecs, 0644);
1791 * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
1793 static void disk_alloc_events(struct gendisk *disk)
1795 struct disk_events *ev;
1797 if (!disk->fops->check_events || !disk->events)
1800 ev = kzalloc(sizeof(*ev), GFP_KERNEL);
1802 pr_warn("%s: failed to initialize events\n", disk->disk_name);
1806 INIT_LIST_HEAD(&ev->node);
1808 spin_lock_init(&ev->lock);
1809 mutex_init(&ev->block_mutex);
1811 ev->poll_msecs = -1;
1812 INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
1817 static void disk_add_events(struct gendisk *disk)
1819 /* FIXME: error handling */
1820 if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
1821 pr_warn("%s: failed to create sysfs files for events\n",
1827 mutex_lock(&disk_events_mutex);
1828 list_add_tail(&disk->ev->node, &disk_events);
1829 mutex_unlock(&disk_events_mutex);
1832 * Block count is initialized to 1 and the following initial
1833 * unblock kicks it into action.
1835 __disk_unblock_events(disk, true);
1838 static void disk_del_events(struct gendisk *disk)
1841 disk_block_events(disk);
1843 mutex_lock(&disk_events_mutex);
1844 list_del_init(&disk->ev->node);
1845 mutex_unlock(&disk_events_mutex);
1848 sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
1851 static void disk_release_events(struct gendisk *disk)
1853 /* the block count should be 1 from disk_del_events() */
1854 WARN_ON_ONCE(disk->ev && disk->ev->block != 1);