5 #include <linux/module.h>
7 #include <linux/genhd.h>
8 #include <linux/kdev_t.h>
9 #include <linux/kernel.h>
10 #include <linux/blkdev.h>
11 #include <linux/backing-dev.h>
12 #include <linux/init.h>
13 #include <linux/spinlock.h>
14 #include <linux/proc_fs.h>
15 #include <linux/seq_file.h>
16 #include <linux/slab.h>
17 #include <linux/kmod.h>
18 #include <linux/kobj_map.h>
19 #include <linux/mutex.h>
20 #include <linux/idr.h>
21 #include <linux/log2.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/badblocks.h>
27 static DEFINE_MUTEX(block_class_lock);
28 struct kobject *block_depr;
30 /* for extended dynamic devt allocation, currently only one major is used */
31 #define NR_EXT_DEVT (1 << MINORBITS)
33 /* For extended devt allocation. ext_devt_lock prevents look up
34 * results from going away underneath its user.
36 static DEFINE_SPINLOCK(ext_devt_lock);
37 static DEFINE_IDR(ext_devt_idr);
39 static struct device_type disk_type;
41 static void disk_check_events(struct disk_events *ev,
42 unsigned int *clearing_ptr);
43 static void disk_alloc_events(struct gendisk *disk);
44 static void disk_add_events(struct gendisk *disk);
45 static void disk_del_events(struct gendisk *disk);
46 static void disk_release_events(struct gendisk *disk);
49 * disk_get_part - get partition
50 * @disk: disk to look partition from
51 * @partno: partition number
53 * Look for partition @partno from @disk. If found, increment
54 * reference count and return it.
60 * Pointer to the found partition on success, NULL if not found.
62 struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
64 struct hd_struct *part = NULL;
65 struct disk_part_tbl *ptbl;
67 if (unlikely(partno < 0))
72 ptbl = rcu_dereference(disk->part_tbl);
73 if (likely(partno < ptbl->len)) {
74 part = rcu_dereference(ptbl->part[partno]);
76 get_device(part_to_dev(part));
83 EXPORT_SYMBOL_GPL(disk_get_part);
86 * disk_part_iter_init - initialize partition iterator
87 * @piter: iterator to initialize
88 * @disk: disk to iterate over
89 * @flags: DISK_PITER_* flags
91 * Initialize @piter so that it iterates over partitions of @disk.
96 void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
99 struct disk_part_tbl *ptbl;
102 ptbl = rcu_dereference(disk->part_tbl);
107 if (flags & DISK_PITER_REVERSE)
108 piter->idx = ptbl->len - 1;
109 else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
114 piter->flags = flags;
118 EXPORT_SYMBOL_GPL(disk_part_iter_init);
121 * disk_part_iter_next - proceed iterator to the next partition and return it
122 * @piter: iterator of interest
124 * Proceed @piter to the next partition and return it.
129 struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
131 struct disk_part_tbl *ptbl;
134 /* put the last partition */
135 disk_put_part(piter->part);
140 ptbl = rcu_dereference(piter->disk->part_tbl);
142 /* determine iteration parameters */
143 if (piter->flags & DISK_PITER_REVERSE) {
145 if (piter->flags & (DISK_PITER_INCL_PART0 |
146 DISK_PITER_INCL_EMPTY_PART0))
155 /* iterate to the next partition */
156 for (; piter->idx != end; piter->idx += inc) {
157 struct hd_struct *part;
159 part = rcu_dereference(ptbl->part[piter->idx]);
162 if (!part_nr_sects_read(part) &&
163 !(piter->flags & DISK_PITER_INCL_EMPTY) &&
164 !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
168 get_device(part_to_dev(part));
178 EXPORT_SYMBOL_GPL(disk_part_iter_next);
181 * disk_part_iter_exit - finish up partition iteration
182 * @piter: iter of interest
184 * Called when iteration is over. Cleans up @piter.
189 void disk_part_iter_exit(struct disk_part_iter *piter)
191 disk_put_part(piter->part);
194 EXPORT_SYMBOL_GPL(disk_part_iter_exit);
196 static inline int sector_in_part(struct hd_struct *part, sector_t sector)
198 return part->start_sect <= sector &&
199 sector < part->start_sect + part_nr_sects_read(part);
203 * disk_map_sector_rcu - map sector to partition
204 * @disk: gendisk of interest
205 * @sector: sector to map
207 * Find out which partition @sector maps to on @disk. This is
208 * primarily used for stats accounting.
211 * RCU read locked. The returned partition pointer is valid only
212 * while preemption is disabled.
215 * Found partition on success, part0 is returned if no partition matches
217 struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
219 struct disk_part_tbl *ptbl;
220 struct hd_struct *part;
223 ptbl = rcu_dereference(disk->part_tbl);
225 part = rcu_dereference(ptbl->last_lookup);
226 if (part && sector_in_part(part, sector))
229 for (i = 1; i < ptbl->len; i++) {
230 part = rcu_dereference(ptbl->part[i]);
232 if (part && sector_in_part(part, sector)) {
233 rcu_assign_pointer(ptbl->last_lookup, part);
239 EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
242 * Can be deleted altogether. Later.
245 static struct blk_major_name {
246 struct blk_major_name *next;
249 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
251 /* index in the above - for now: assume no multimajor ranges */
252 static inline int major_to_index(unsigned major)
254 return major % BLKDEV_MAJOR_HASH_SIZE;
257 #ifdef CONFIG_PROC_FS
258 void blkdev_show(struct seq_file *seqf, off_t offset)
260 struct blk_major_name *dp;
262 if (offset < BLKDEV_MAJOR_HASH_SIZE) {
263 mutex_lock(&block_class_lock);
264 for (dp = major_names[offset]; dp; dp = dp->next)
265 seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
266 mutex_unlock(&block_class_lock);
269 #endif /* CONFIG_PROC_FS */
272 * register_blkdev - register a new block device
274 * @major: the requested major device number [1..255]. If @major=0, try to
275 * allocate any unused major number.
276 * @name: the name of the new block device as a zero terminated string
278 * The @name must be unique within the system.
280 * The return value depends on the @major input parameter.
281 * - if a major device number was requested in range [1..255] then the
282 * function returns zero on success, or a negative error code
283 * - if any unused major number was requested with @major=0 parameter
284 * then the return value is the allocated major number in range
285 * [1..255] or a negative error code otherwise
287 int register_blkdev(unsigned int major, const char *name)
289 struct blk_major_name **n, *p;
292 mutex_lock(&block_class_lock);
296 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
297 if (major_names[index] == NULL)
302 printk("register_blkdev: failed to get major for %s\n",
311 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
318 strlcpy(p->name, name, sizeof(p->name));
320 index = major_to_index(major);
322 for (n = &major_names[index]; *n; n = &(*n)->next) {
323 if ((*n)->major == major)
332 printk("register_blkdev: cannot get major %d for %s\n",
337 mutex_unlock(&block_class_lock);
341 EXPORT_SYMBOL(register_blkdev);
343 void unregister_blkdev(unsigned int major, const char *name)
345 struct blk_major_name **n;
346 struct blk_major_name *p = NULL;
347 int index = major_to_index(major);
349 mutex_lock(&block_class_lock);
350 for (n = &major_names[index]; *n; n = &(*n)->next)
351 if ((*n)->major == major)
353 if (!*n || strcmp((*n)->name, name)) {
359 mutex_unlock(&block_class_lock);
363 EXPORT_SYMBOL(unregister_blkdev);
365 static struct kobj_map *bdev_map;
368 * blk_mangle_minor - scatter minor numbers apart
369 * @minor: minor number to mangle
371 * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
372 * is enabled. Mangling twice gives the original value.
380 static int blk_mangle_minor(int minor)
382 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
385 for (i = 0; i < MINORBITS / 2; i++) {
386 int low = minor & (1 << i);
387 int high = minor & (1 << (MINORBITS - 1 - i));
388 int distance = MINORBITS - 1 - 2 * i;
390 minor ^= low | high; /* clear both bits */
391 low <<= distance; /* swap the positions */
393 minor |= low | high; /* and set */
400 * blk_alloc_devt - allocate a dev_t for a partition
401 * @part: partition to allocate dev_t for
402 * @devt: out parameter for resulting dev_t
404 * Allocate a dev_t for block device.
407 * 0 on success, allocated dev_t is returned in *@devt. -errno on
413 int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
415 struct gendisk *disk = part_to_disk(part);
418 /* in consecutive minor range? */
419 if (part->partno < disk->minors) {
420 *devt = MKDEV(disk->major, disk->first_minor + part->partno);
424 /* allocate ext devt */
425 idr_preload(GFP_KERNEL);
427 spin_lock_bh(&ext_devt_lock);
428 idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT);
429 spin_unlock_bh(&ext_devt_lock);
433 return idx == -ENOSPC ? -EBUSY : idx;
435 *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
440 * blk_free_devt - free a dev_t
441 * @devt: dev_t to free
443 * Free @devt which was allocated using blk_alloc_devt().
448 void blk_free_devt(dev_t devt)
450 if (devt == MKDEV(0, 0))
453 if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
454 spin_lock_bh(&ext_devt_lock);
455 idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
456 spin_unlock_bh(&ext_devt_lock);
460 static char *bdevt_str(dev_t devt, char *buf)
462 if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
463 char tbuf[BDEVT_SIZE];
464 snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
465 snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
467 snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
473 * Register device numbers dev..(dev+range-1)
474 * range must be nonzero
475 * The hash chain is sorted on range, so that subranges can override.
477 void blk_register_region(dev_t devt, unsigned long range, struct module *module,
478 struct kobject *(*probe)(dev_t, int *, void *),
479 int (*lock)(dev_t, void *), void *data)
481 kobj_map(bdev_map, devt, range, module, probe, lock, data);
484 EXPORT_SYMBOL(blk_register_region);
486 void blk_unregister_region(dev_t devt, unsigned long range)
488 kobj_unmap(bdev_map, devt, range);
491 EXPORT_SYMBOL(blk_unregister_region);
493 static struct kobject *exact_match(dev_t devt, int *partno, void *data)
495 struct gendisk *p = data;
497 return &disk_to_dev(p)->kobj;
500 static int exact_lock(dev_t devt, void *data)
502 struct gendisk *p = data;
509 static void register_disk(struct device *parent, struct gendisk *disk)
511 struct device *ddev = disk_to_dev(disk);
512 struct block_device *bdev;
513 struct disk_part_iter piter;
514 struct hd_struct *part;
517 ddev->parent = parent;
519 dev_set_name(ddev, "%s", disk->disk_name);
521 /* delay uevents, until we scanned partition table */
522 dev_set_uevent_suppress(ddev, 1);
524 if (device_add(ddev))
526 if (!sysfs_deprecated) {
527 err = sysfs_create_link(block_depr, &ddev->kobj,
528 kobject_name(&ddev->kobj));
536 * avoid probable deadlock caused by allocating memory with
537 * GFP_KERNEL in runtime_resume callback of its all ancestor
540 pm_runtime_set_memalloc_noio(ddev, true);
542 disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
543 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
545 /* No minors to use for partitions */
546 if (!disk_part_scan_enabled(disk))
549 /* No such device (e.g., media were just removed) */
550 if (!get_capacity(disk))
553 bdev = bdget_disk(disk, 0);
557 bdev->bd_invalidated = 1;
558 err = blkdev_get(bdev, FMODE_READ, NULL);
561 blkdev_put(bdev, FMODE_READ);
564 /* announce disk after possible partitions are created */
565 dev_set_uevent_suppress(ddev, 0);
566 kobject_uevent(&ddev->kobj, KOBJ_ADD);
568 /* announce possible partitions */
569 disk_part_iter_init(&piter, disk, 0);
570 while ((part = disk_part_iter_next(&piter)))
571 kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
572 disk_part_iter_exit(&piter);
575 void put_disk_devt(struct disk_devt *disk_devt)
577 if (disk_devt && atomic_dec_and_test(&disk_devt->count))
578 disk_devt->release(disk_devt);
580 EXPORT_SYMBOL(put_disk_devt);
582 void get_disk_devt(struct disk_devt *disk_devt)
585 atomic_inc(&disk_devt->count);
587 EXPORT_SYMBOL(get_disk_devt);
590 * device_add_disk - add partitioning information to kernel list
591 * @parent: parent device for the disk
592 * @disk: per-device partitioning information
594 * This function registers the partitioning information in @disk
597 * FIXME: error handling
599 void device_add_disk(struct device *parent, struct gendisk *disk)
601 struct backing_dev_info *bdi;
605 /* minors == 0 indicates to use ext devt from part0 and should
606 * be accompanied with EXT_DEVT flag. Make sure all
607 * parameters make sense.
609 WARN_ON(disk->minors && !(disk->major || disk->first_minor));
610 WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT));
612 disk->flags |= GENHD_FL_UP;
614 retval = blk_alloc_devt(&disk->part0, &devt);
619 disk_to_dev(disk)->devt = devt;
621 /* ->major and ->first_minor aren't supposed to be
622 * dereferenced from here on, but set them just in case.
624 disk->major = MAJOR(devt);
625 disk->first_minor = MINOR(devt);
627 disk_alloc_events(disk);
630 * Take a reference on the devt and assign it to queue since it
631 * must not be reallocated while the bdi is registered
633 disk->queue->disk_devt = disk->disk_devt;
634 get_disk_devt(disk->disk_devt);
636 /* Register BDI before referencing it from bdev */
637 bdi = disk->queue->backing_dev_info;
638 bdi_register_owner(bdi, disk_to_dev(disk));
640 blk_register_region(disk_devt(disk), disk->minors, NULL,
641 exact_match, exact_lock, disk);
642 register_disk(parent, disk);
643 blk_register_queue(disk);
646 * Take an extra ref on queue which will be put on disk_release()
647 * so that it sticks around as long as @disk is there.
649 WARN_ON_ONCE(!blk_get_queue(disk->queue));
651 retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
655 disk_add_events(disk);
656 blk_integrity_add(disk);
658 EXPORT_SYMBOL(device_add_disk);
660 void del_gendisk(struct gendisk *disk)
662 struct disk_part_iter piter;
663 struct hd_struct *part;
665 blk_integrity_del(disk);
666 disk_del_events(disk);
668 /* invalidate stuff */
669 disk_part_iter_init(&piter, disk,
670 DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
671 while ((part = disk_part_iter_next(&piter))) {
672 invalidate_partition(disk, part->partno);
673 bdev_unhash_inode(part_devt(part));
674 delete_partition(disk, part->partno);
676 disk_part_iter_exit(&piter);
678 invalidate_partition(disk, 0);
679 bdev_unhash_inode(disk_devt(disk));
680 set_capacity(disk, 0);
681 disk->flags &= ~GENHD_FL_UP;
683 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
685 * Unregister bdi before releasing device numbers (as they can get
686 * reused and we'd get clashes in sysfs).
688 bdi_unregister(disk->queue->backing_dev_info);
689 blk_unregister_queue(disk);
690 blk_unregister_region(disk_devt(disk), disk->minors);
692 part_stat_set_all(&disk->part0, 0);
693 disk->part0.stamp = 0;
695 kobject_put(disk->part0.holder_dir);
696 kobject_put(disk->slave_dir);
697 if (!sysfs_deprecated)
698 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
699 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
700 device_del(disk_to_dev(disk));
702 EXPORT_SYMBOL(del_gendisk);
704 /* sysfs access to bad-blocks list. */
705 static ssize_t disk_badblocks_show(struct device *dev,
706 struct device_attribute *attr,
709 struct gendisk *disk = dev_to_disk(dev);
712 return sprintf(page, "\n");
714 return badblocks_show(disk->bb, page, 0);
717 static ssize_t disk_badblocks_store(struct device *dev,
718 struct device_attribute *attr,
719 const char *page, size_t len)
721 struct gendisk *disk = dev_to_disk(dev);
726 return badblocks_store(disk->bb, page, len, 0);
730 * get_gendisk - get partitioning information for a given device
731 * @devt: device to get partitioning information for
732 * @partno: returned partition index
734 * This function gets the structure containing partitioning
735 * information for the given device @devt.
737 struct gendisk *get_gendisk(dev_t devt, int *partno)
739 struct gendisk *disk = NULL;
741 if (MAJOR(devt) != BLOCK_EXT_MAJOR) {
742 struct kobject *kobj;
744 kobj = kobj_lookup(bdev_map, devt, partno);
746 disk = dev_to_disk(kobj_to_dev(kobj));
748 struct hd_struct *part;
750 spin_lock_bh(&ext_devt_lock);
751 part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
752 if (part && get_disk(part_to_disk(part))) {
753 *partno = part->partno;
754 disk = part_to_disk(part);
756 spin_unlock_bh(&ext_devt_lock);
761 EXPORT_SYMBOL(get_gendisk);
764 * bdget_disk - do bdget() by gendisk and partition number
765 * @disk: gendisk of interest
766 * @partno: partition number
768 * Find partition @partno from @disk, do bdget() on it.
774 * Resulting block_device on success, NULL on failure.
776 struct block_device *bdget_disk(struct gendisk *disk, int partno)
778 struct hd_struct *part;
779 struct block_device *bdev = NULL;
781 part = disk_get_part(disk, partno);
783 bdev = bdget(part_devt(part));
788 EXPORT_SYMBOL(bdget_disk);
791 * print a full list of all partitions - intended for places where the root
792 * filesystem can't be mounted and thus to give the victim some idea of what
795 void __init printk_all_partitions(void)
797 struct class_dev_iter iter;
800 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
801 while ((dev = class_dev_iter_next(&iter))) {
802 struct gendisk *disk = dev_to_disk(dev);
803 struct disk_part_iter piter;
804 struct hd_struct *part;
805 char name_buf[BDEVNAME_SIZE];
806 char devt_buf[BDEVT_SIZE];
809 * Don't show empty devices or things that have been
812 if (get_capacity(disk) == 0 ||
813 (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
817 * Note, unlike /proc/partitions, I am showing the
818 * numbers in hex - the same format as the root=
821 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
822 while ((part = disk_part_iter_next(&piter))) {
823 bool is_part0 = part == &disk->part0;
825 printk("%s%s %10llu %s %s", is_part0 ? "" : " ",
826 bdevt_str(part_devt(part), devt_buf),
827 (unsigned long long)part_nr_sects_read(part) >> 1
828 , disk_name(disk, part->partno, name_buf),
829 part->info ? part->info->uuid : "");
831 if (dev->parent && dev->parent->driver)
832 printk(" driver: %s\n",
833 dev->parent->driver->name);
835 printk(" (driver?)\n");
839 disk_part_iter_exit(&piter);
841 class_dev_iter_exit(&iter);
844 #ifdef CONFIG_PROC_FS
846 static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
849 struct class_dev_iter *iter;
852 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
854 return ERR_PTR(-ENOMEM);
856 seqf->private = iter;
857 class_dev_iter_init(iter, &block_class, NULL, &disk_type);
859 dev = class_dev_iter_next(iter);
864 return dev_to_disk(dev);
867 static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
872 dev = class_dev_iter_next(seqf->private);
874 return dev_to_disk(dev);
879 static void disk_seqf_stop(struct seq_file *seqf, void *v)
881 struct class_dev_iter *iter = seqf->private;
883 /* stop is called even after start failed :-( */
885 class_dev_iter_exit(iter);
887 seqf->private = NULL;
891 static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
895 p = disk_seqf_start(seqf, pos);
896 if (!IS_ERR_OR_NULL(p) && !*pos)
897 seq_puts(seqf, "major minor #blocks name\n\n");
901 static int show_partition(struct seq_file *seqf, void *v)
903 struct gendisk *sgp = v;
904 struct disk_part_iter piter;
905 struct hd_struct *part;
906 char buf[BDEVNAME_SIZE];
908 /* Don't show non-partitionable removeable devices or empty devices */
909 if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
910 (sgp->flags & GENHD_FL_REMOVABLE)))
912 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
915 /* show the full disk and all non-0 size partitions of it */
916 disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
917 while ((part = disk_part_iter_next(&piter)))
918 seq_printf(seqf, "%4d %7d %10llu %s\n",
919 MAJOR(part_devt(part)), MINOR(part_devt(part)),
920 (unsigned long long)part_nr_sects_read(part) >> 1,
921 disk_name(sgp, part->partno, buf));
922 disk_part_iter_exit(&piter);
927 static const struct seq_operations partitions_op = {
928 .start = show_partition_start,
929 .next = disk_seqf_next,
930 .stop = disk_seqf_stop,
931 .show = show_partition
934 static int partitions_open(struct inode *inode, struct file *file)
936 return seq_open(file, &partitions_op);
939 static const struct file_operations proc_partitions_operations = {
940 .open = partitions_open,
943 .release = seq_release,
948 static struct kobject *base_probe(dev_t devt, int *partno, void *data)
950 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
951 /* Make old-style 2.4 aliases work */
952 request_module("block-major-%d", MAJOR(devt));
956 static int __init genhd_device_init(void)
960 block_class.dev_kobj = sysfs_dev_block_kobj;
961 error = class_register(&block_class);
964 bdev_map = kobj_map_init(base_probe, &block_class_lock);
967 register_blkdev(BLOCK_EXT_MAJOR, "blkext");
969 /* create top-level block dir */
970 if (!sysfs_deprecated)
971 block_depr = kobject_create_and_add("block", NULL);
975 subsys_initcall(genhd_device_init);
977 static ssize_t disk_range_show(struct device *dev,
978 struct device_attribute *attr, char *buf)
980 struct gendisk *disk = dev_to_disk(dev);
982 return sprintf(buf, "%d\n", disk->minors);
985 static ssize_t disk_ext_range_show(struct device *dev,
986 struct device_attribute *attr, char *buf)
988 struct gendisk *disk = dev_to_disk(dev);
990 return sprintf(buf, "%d\n", disk_max_parts(disk));
993 static ssize_t disk_removable_show(struct device *dev,
994 struct device_attribute *attr, char *buf)
996 struct gendisk *disk = dev_to_disk(dev);
998 return sprintf(buf, "%d\n",
999 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
1002 static ssize_t disk_ro_show(struct device *dev,
1003 struct device_attribute *attr, char *buf)
1005 struct gendisk *disk = dev_to_disk(dev);
1007 return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
1010 static ssize_t disk_capability_show(struct device *dev,
1011 struct device_attribute *attr, char *buf)
1013 struct gendisk *disk = dev_to_disk(dev);
1015 return sprintf(buf, "%x\n", disk->flags);
1018 static ssize_t disk_alignment_offset_show(struct device *dev,
1019 struct device_attribute *attr,
1022 struct gendisk *disk = dev_to_disk(dev);
1024 return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue));
1027 static ssize_t disk_discard_alignment_show(struct device *dev,
1028 struct device_attribute *attr,
1031 struct gendisk *disk = dev_to_disk(dev);
1033 return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
1036 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
1037 static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL);
1038 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
1039 static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
1040 static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
1041 static DEVICE_ATTR(alignment_offset, S_IRUGO, disk_alignment_offset_show, NULL);
1042 static DEVICE_ATTR(discard_alignment, S_IRUGO, disk_discard_alignment_show,
1044 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
1045 static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
1046 static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
1047 static DEVICE_ATTR(badblocks, S_IRUGO | S_IWUSR, disk_badblocks_show,
1048 disk_badblocks_store);
1049 #ifdef CONFIG_FAIL_MAKE_REQUEST
1050 static struct device_attribute dev_attr_fail =
1051 __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
1053 #ifdef CONFIG_FAIL_IO_TIMEOUT
1054 static struct device_attribute dev_attr_fail_timeout =
1055 __ATTR(io-timeout-fail, S_IRUGO|S_IWUSR, part_timeout_show,
1056 part_timeout_store);
1059 static struct attribute *disk_attrs[] = {
1060 &dev_attr_range.attr,
1061 &dev_attr_ext_range.attr,
1062 &dev_attr_removable.attr,
1064 &dev_attr_size.attr,
1065 &dev_attr_alignment_offset.attr,
1066 &dev_attr_discard_alignment.attr,
1067 &dev_attr_capability.attr,
1068 &dev_attr_stat.attr,
1069 &dev_attr_inflight.attr,
1070 &dev_attr_badblocks.attr,
1071 #ifdef CONFIG_FAIL_MAKE_REQUEST
1072 &dev_attr_fail.attr,
1074 #ifdef CONFIG_FAIL_IO_TIMEOUT
1075 &dev_attr_fail_timeout.attr,
1080 static struct attribute_group disk_attr_group = {
1081 .attrs = disk_attrs,
1084 static const struct attribute_group *disk_attr_groups[] = {
1090 * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
1091 * @disk: disk to replace part_tbl for
1092 * @new_ptbl: new part_tbl to install
1094 * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The
1095 * original ptbl is freed using RCU callback.
1098 * Matching bd_mutx locked.
1100 static void disk_replace_part_tbl(struct gendisk *disk,
1101 struct disk_part_tbl *new_ptbl)
1103 struct disk_part_tbl *old_ptbl = disk->part_tbl;
1105 rcu_assign_pointer(disk->part_tbl, new_ptbl);
1108 rcu_assign_pointer(old_ptbl->last_lookup, NULL);
1109 kfree_rcu(old_ptbl, rcu_head);
1114 * disk_expand_part_tbl - expand disk->part_tbl
1115 * @disk: disk to expand part_tbl for
1116 * @partno: expand such that this partno can fit in
1118 * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl
1119 * uses RCU to allow unlocked dereferencing for stats and other stuff.
1122 * Matching bd_mutex locked, might sleep.
1125 * 0 on success, -errno on failure.
1127 int disk_expand_part_tbl(struct gendisk *disk, int partno)
1129 struct disk_part_tbl *old_ptbl = disk->part_tbl;
1130 struct disk_part_tbl *new_ptbl;
1131 int len = old_ptbl ? old_ptbl->len : 0;
1136 * check for int overflow, since we can get here from blkpg_ioctl()
1137 * with a user passed 'partno'.
1139 target = partno + 1;
1143 /* disk_max_parts() is zero during initialization, ignore if so */
1144 if (disk_max_parts(disk) && target > disk_max_parts(disk))
1150 size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]);
1151 new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id);
1155 new_ptbl->len = target;
1157 for (i = 0; i < len; i++)
1158 rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
1160 disk_replace_part_tbl(disk, new_ptbl);
1164 static void disk_release(struct device *dev)
1166 struct gendisk *disk = dev_to_disk(dev);
1168 blk_free_devt(dev->devt);
1169 disk_release_events(disk);
1170 kfree(disk->random);
1171 disk_replace_part_tbl(disk, NULL);
1172 hd_free_part(&disk->part0);
1174 blk_put_queue(disk->queue);
1177 struct class block_class = {
1181 static char *block_devnode(struct device *dev, umode_t *mode,
1182 kuid_t *uid, kgid_t *gid)
1184 struct gendisk *disk = dev_to_disk(dev);
1187 return disk->devnode(disk, mode);
1191 static struct device_type disk_type = {
1193 .groups = disk_attr_groups,
1194 .release = disk_release,
1195 .devnode = block_devnode,
1198 #ifdef CONFIG_PROC_FS
1200 * aggregate disk stat collector. Uses the same stats that the sysfs
1201 * entries do, above, but makes them available through one seq_file.
1203 * The output looks suspiciously like /proc/partitions with a bunch of
1206 static int diskstats_show(struct seq_file *seqf, void *v)
1208 struct gendisk *gp = v;
1209 struct disk_part_iter piter;
1210 struct hd_struct *hd;
1211 char buf[BDEVNAME_SIZE];
1215 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1216 seq_puts(seqf, "major minor name"
1217 " rio rmerge rsect ruse wio wmerge "
1218 "wsect wuse running use aveq"
1222 disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
1223 while ((hd = disk_part_iter_next(&piter))) {
1224 cpu = part_stat_lock();
1225 part_round_stats(cpu, hd);
1227 seq_printf(seqf, "%4d %7d %s %lu %lu %lu "
1228 "%u %lu %lu %lu %u %u %u %u\n",
1229 MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
1230 disk_name(gp, hd->partno, buf),
1231 part_stat_read(hd, ios[READ]),
1232 part_stat_read(hd, merges[READ]),
1233 part_stat_read(hd, sectors[READ]),
1234 jiffies_to_msecs(part_stat_read(hd, ticks[READ])),
1235 part_stat_read(hd, ios[WRITE]),
1236 part_stat_read(hd, merges[WRITE]),
1237 part_stat_read(hd, sectors[WRITE]),
1238 jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])),
1240 jiffies_to_msecs(part_stat_read(hd, io_ticks)),
1241 jiffies_to_msecs(part_stat_read(hd, time_in_queue))
1244 disk_part_iter_exit(&piter);
1249 static const struct seq_operations diskstats_op = {
1250 .start = disk_seqf_start,
1251 .next = disk_seqf_next,
1252 .stop = disk_seqf_stop,
1253 .show = diskstats_show
1256 static int diskstats_open(struct inode *inode, struct file *file)
1258 return seq_open(file, &diskstats_op);
1261 static const struct file_operations proc_diskstats_operations = {
1262 .open = diskstats_open,
1264 .llseek = seq_lseek,
1265 .release = seq_release,
1268 static int __init proc_genhd_init(void)
1270 proc_create("diskstats", 0, NULL, &proc_diskstats_operations);
1271 proc_create("partitions", 0, NULL, &proc_partitions_operations);
1274 module_init(proc_genhd_init);
1275 #endif /* CONFIG_PROC_FS */
1277 dev_t blk_lookup_devt(const char *name, int partno)
1279 dev_t devt = MKDEV(0, 0);
1280 struct class_dev_iter iter;
1283 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
1284 while ((dev = class_dev_iter_next(&iter))) {
1285 struct gendisk *disk = dev_to_disk(dev);
1286 struct hd_struct *part;
1288 if (strcmp(dev_name(dev), name))
1291 if (partno < disk->minors) {
1292 /* We need to return the right devno, even
1293 * if the partition doesn't exist yet.
1295 devt = MKDEV(MAJOR(dev->devt),
1296 MINOR(dev->devt) + partno);
1299 part = disk_get_part(disk, partno);
1301 devt = part_devt(part);
1302 disk_put_part(part);
1305 disk_put_part(part);
1307 class_dev_iter_exit(&iter);
1310 EXPORT_SYMBOL(blk_lookup_devt);
1312 struct gendisk *alloc_disk(int minors)
1314 return alloc_disk_node(minors, NUMA_NO_NODE);
1316 EXPORT_SYMBOL(alloc_disk);
1318 struct gendisk *alloc_disk_node(int minors, int node_id)
1320 struct gendisk *disk;
1322 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
1324 if (!init_part_stats(&disk->part0)) {
1328 disk->node_id = node_id;
1329 if (disk_expand_part_tbl(disk, 0)) {
1330 free_part_stats(&disk->part0);
1334 disk->part_tbl->part[0] = &disk->part0;
1337 * set_capacity() and get_capacity() currently don't use
1338 * seqcounter to read/update the part0->nr_sects. Still init
1339 * the counter as we can read the sectors in IO submission
1340 * patch using seqence counters.
1342 * TODO: Ideally set_capacity() and get_capacity() should be
1343 * converted to make use of bd_mutex and sequence counters.
1345 seqcount_init(&disk->part0.nr_sects_seq);
1346 if (hd_ref_init(&disk->part0)) {
1347 hd_free_part(&disk->part0);
1352 disk->minors = minors;
1353 rand_initialize_disk(disk);
1354 disk_to_dev(disk)->class = &block_class;
1355 disk_to_dev(disk)->type = &disk_type;
1356 device_initialize(disk_to_dev(disk));
1360 EXPORT_SYMBOL(alloc_disk_node);
1362 struct kobject *get_disk(struct gendisk *disk)
1364 struct module *owner;
1365 struct kobject *kobj;
1369 owner = disk->fops->owner;
1370 if (owner && !try_module_get(owner))
1372 kobj = kobject_get(&disk_to_dev(disk)->kobj);
1381 EXPORT_SYMBOL(get_disk);
1383 void put_disk(struct gendisk *disk)
1386 kobject_put(&disk_to_dev(disk)->kobj);
1389 EXPORT_SYMBOL(put_disk);
1391 static void set_disk_ro_uevent(struct gendisk *gd, int ro)
1393 char event[] = "DISK_RO=1";
1394 char *envp[] = { event, NULL };
1398 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
1401 void set_device_ro(struct block_device *bdev, int flag)
1403 bdev->bd_part->policy = flag;
1406 EXPORT_SYMBOL(set_device_ro);
1408 void set_disk_ro(struct gendisk *disk, int flag)
1410 struct disk_part_iter piter;
1411 struct hd_struct *part;
1413 if (disk->part0.policy != flag) {
1414 set_disk_ro_uevent(disk, flag);
1415 disk->part0.policy = flag;
1418 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
1419 while ((part = disk_part_iter_next(&piter)))
1420 part->policy = flag;
1421 disk_part_iter_exit(&piter);
1424 EXPORT_SYMBOL(set_disk_ro);
1426 int bdev_read_only(struct block_device *bdev)
1430 return bdev->bd_part->policy;
1433 EXPORT_SYMBOL(bdev_read_only);
1435 int invalidate_partition(struct gendisk *disk, int partno)
1438 struct block_device *bdev = bdget_disk(disk, partno);
1441 res = __invalidate_device(bdev, true);
1447 EXPORT_SYMBOL(invalidate_partition);
1450 * Disk events - monitor disk events like media change and eject request.
1452 struct disk_events {
1453 struct list_head node; /* all disk_event's */
1454 struct gendisk *disk; /* the associated disk */
1457 struct mutex block_mutex; /* protects blocking */
1458 int block; /* event blocking depth */
1459 unsigned int pending; /* events already sent out */
1460 unsigned int clearing; /* events being cleared */
1462 long poll_msecs; /* interval, -1 for default */
1463 struct delayed_work dwork;
1466 static const char *disk_events_strs[] = {
1467 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
1468 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
1471 static char *disk_uevents[] = {
1472 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
1473 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
1476 /* list of all disk_events */
1477 static DEFINE_MUTEX(disk_events_mutex);
1478 static LIST_HEAD(disk_events);
1480 /* disable in-kernel polling by default */
1481 static unsigned long disk_events_dfl_poll_msecs;
1483 static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
1485 struct disk_events *ev = disk->ev;
1486 long intv_msecs = 0;
1489 * If device-specific poll interval is set, always use it. If
1490 * the default is being used, poll iff there are events which
1491 * can't be monitored asynchronously.
1493 if (ev->poll_msecs >= 0)
1494 intv_msecs = ev->poll_msecs;
1495 else if (disk->events & ~disk->async_events)
1496 intv_msecs = disk_events_dfl_poll_msecs;
1498 return msecs_to_jiffies(intv_msecs);
1502 * disk_block_events - block and flush disk event checking
1503 * @disk: disk to block events for
1505 * On return from this function, it is guaranteed that event checking
1506 * isn't in progress and won't happen until unblocked by
1507 * disk_unblock_events(). Events blocking is counted and the actual
1508 * unblocking happens after the matching number of unblocks are done.
1510 * Note that this intentionally does not block event checking from
1511 * disk_clear_events().
1516 void disk_block_events(struct gendisk *disk)
1518 struct disk_events *ev = disk->ev;
1519 unsigned long flags;
1526 * Outer mutex ensures that the first blocker completes canceling
1527 * the event work before further blockers are allowed to finish.
1529 mutex_lock(&ev->block_mutex);
1531 spin_lock_irqsave(&ev->lock, flags);
1532 cancel = !ev->block++;
1533 spin_unlock_irqrestore(&ev->lock, flags);
1536 cancel_delayed_work_sync(&disk->ev->dwork);
1538 mutex_unlock(&ev->block_mutex);
1541 static void __disk_unblock_events(struct gendisk *disk, bool check_now)
1543 struct disk_events *ev = disk->ev;
1545 unsigned long flags;
1547 spin_lock_irqsave(&ev->lock, flags);
1549 if (WARN_ON_ONCE(ev->block <= 0))
1555 intv = disk_events_poll_jiffies(disk);
1557 queue_delayed_work(system_freezable_power_efficient_wq,
1560 queue_delayed_work(system_freezable_power_efficient_wq,
1563 spin_unlock_irqrestore(&ev->lock, flags);
1567 * disk_unblock_events - unblock disk event checking
1568 * @disk: disk to unblock events for
1570 * Undo disk_block_events(). When the block count reaches zero, it
1571 * starts events polling if configured.
1574 * Don't care. Safe to call from irq context.
1576 void disk_unblock_events(struct gendisk *disk)
1579 __disk_unblock_events(disk, false);
1583 * disk_flush_events - schedule immediate event checking and flushing
1584 * @disk: disk to check and flush events for
1585 * @mask: events to flush
1587 * Schedule immediate event checking on @disk if not blocked. Events in
1588 * @mask are scheduled to be cleared from the driver. Note that this
1589 * doesn't clear the events from @disk->ev.
1592 * If @mask is non-zero must be called with bdev->bd_mutex held.
1594 void disk_flush_events(struct gendisk *disk, unsigned int mask)
1596 struct disk_events *ev = disk->ev;
1601 spin_lock_irq(&ev->lock);
1602 ev->clearing |= mask;
1604 mod_delayed_work(system_freezable_power_efficient_wq,
1606 spin_unlock_irq(&ev->lock);
1610 * disk_clear_events - synchronously check, clear and return pending events
1611 * @disk: disk to fetch and clear events from
1612 * @mask: mask of events to be fetched and cleared
1614 * Disk events are synchronously checked and pending events in @mask
1615 * are cleared and returned. This ignores the block count.
1620 unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
1622 const struct block_device_operations *bdops = disk->fops;
1623 struct disk_events *ev = disk->ev;
1624 unsigned int pending;
1625 unsigned int clearing = mask;
1628 /* for drivers still using the old ->media_changed method */
1629 if ((mask & DISK_EVENT_MEDIA_CHANGE) &&
1630 bdops->media_changed && bdops->media_changed(disk))
1631 return DISK_EVENT_MEDIA_CHANGE;
1635 disk_block_events(disk);
1638 * store the union of mask and ev->clearing on the stack so that the
1639 * race with disk_flush_events does not cause ambiguity (ev->clearing
1640 * can still be modified even if events are blocked).
1642 spin_lock_irq(&ev->lock);
1643 clearing |= ev->clearing;
1645 spin_unlock_irq(&ev->lock);
1647 disk_check_events(ev, &clearing);
1649 * if ev->clearing is not 0, the disk_flush_events got called in the
1650 * middle of this function, so we want to run the workfn without delay.
1652 __disk_unblock_events(disk, ev->clearing ? true : false);
1654 /* then, fetch and clear pending events */
1655 spin_lock_irq(&ev->lock);
1656 pending = ev->pending & mask;
1657 ev->pending &= ~mask;
1658 spin_unlock_irq(&ev->lock);
1659 WARN_ON_ONCE(clearing & mask);
1665 * Separate this part out so that a different pointer for clearing_ptr can be
1666 * passed in for disk_clear_events.
1668 static void disk_events_workfn(struct work_struct *work)
1670 struct delayed_work *dwork = to_delayed_work(work);
1671 struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
1673 disk_check_events(ev, &ev->clearing);
1676 static void disk_check_events(struct disk_events *ev,
1677 unsigned int *clearing_ptr)
1679 struct gendisk *disk = ev->disk;
1680 char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
1681 unsigned int clearing = *clearing_ptr;
1682 unsigned int events;
1684 int nr_events = 0, i;
1687 events = disk->fops->check_events(disk, clearing);
1689 /* accumulate pending events and schedule next poll if necessary */
1690 spin_lock_irq(&ev->lock);
1692 events &= ~ev->pending;
1693 ev->pending |= events;
1694 *clearing_ptr &= ~clearing;
1696 intv = disk_events_poll_jiffies(disk);
1697 if (!ev->block && intv)
1698 queue_delayed_work(system_freezable_power_efficient_wq,
1701 spin_unlock_irq(&ev->lock);
1704 * Tell userland about new events. Only the events listed in
1705 * @disk->events are reported. Unlisted events are processed the
1706 * same internally but never get reported to userland.
1708 for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
1709 if (events & disk->events & (1 << i))
1710 envp[nr_events++] = disk_uevents[i];
1713 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
1717 * A disk events enabled device has the following sysfs nodes under
1718 * its /sys/block/X/ directory.
1720 * events : list of all supported events
1721 * events_async : list of events which can be detected w/o polling
1722 * events_poll_msecs : polling interval, 0: disable, -1: system default
1724 static ssize_t __disk_events_show(unsigned int events, char *buf)
1726 const char *delim = "";
1730 for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
1731 if (events & (1 << i)) {
1732 pos += sprintf(buf + pos, "%s%s",
1733 delim, disk_events_strs[i]);
1737 pos += sprintf(buf + pos, "\n");
1741 static ssize_t disk_events_show(struct device *dev,
1742 struct device_attribute *attr, char *buf)
1744 struct gendisk *disk = dev_to_disk(dev);
1746 return __disk_events_show(disk->events, buf);
1749 static ssize_t disk_events_async_show(struct device *dev,
1750 struct device_attribute *attr, char *buf)
1752 struct gendisk *disk = dev_to_disk(dev);
1754 return __disk_events_show(disk->async_events, buf);
1757 static ssize_t disk_events_poll_msecs_show(struct device *dev,
1758 struct device_attribute *attr,
1761 struct gendisk *disk = dev_to_disk(dev);
1763 return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
1766 static ssize_t disk_events_poll_msecs_store(struct device *dev,
1767 struct device_attribute *attr,
1768 const char *buf, size_t count)
1770 struct gendisk *disk = dev_to_disk(dev);
1773 if (!count || !sscanf(buf, "%ld", &intv))
1776 if (intv < 0 && intv != -1)
1779 disk_block_events(disk);
1780 disk->ev->poll_msecs = intv;
1781 __disk_unblock_events(disk, true);
1786 static const DEVICE_ATTR(events, S_IRUGO, disk_events_show, NULL);
1787 static const DEVICE_ATTR(events_async, S_IRUGO, disk_events_async_show, NULL);
1788 static const DEVICE_ATTR(events_poll_msecs, S_IRUGO|S_IWUSR,
1789 disk_events_poll_msecs_show,
1790 disk_events_poll_msecs_store);
1792 static const struct attribute *disk_events_attrs[] = {
1793 &dev_attr_events.attr,
1794 &dev_attr_events_async.attr,
1795 &dev_attr_events_poll_msecs.attr,
1800 * The default polling interval can be specified by the kernel
1801 * parameter block.events_dfl_poll_msecs which defaults to 0
1802 * (disable). This can also be modified runtime by writing to
1803 * /sys/module/block/events_dfl_poll_msecs.
1805 static int disk_events_set_dfl_poll_msecs(const char *val,
1806 const struct kernel_param *kp)
1808 struct disk_events *ev;
1811 ret = param_set_ulong(val, kp);
1815 mutex_lock(&disk_events_mutex);
1817 list_for_each_entry(ev, &disk_events, node)
1818 disk_flush_events(ev->disk, 0);
1820 mutex_unlock(&disk_events_mutex);
1825 static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
1826 .set = disk_events_set_dfl_poll_msecs,
1827 .get = param_get_ulong,
1830 #undef MODULE_PARAM_PREFIX
1831 #define MODULE_PARAM_PREFIX "block."
1833 module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
1834 &disk_events_dfl_poll_msecs, 0644);
1837 * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
1839 static void disk_alloc_events(struct gendisk *disk)
1841 struct disk_events *ev;
1843 if (!disk->fops->check_events)
1846 ev = kzalloc(sizeof(*ev), GFP_KERNEL);
1848 pr_warn("%s: failed to initialize events\n", disk->disk_name);
1852 INIT_LIST_HEAD(&ev->node);
1854 spin_lock_init(&ev->lock);
1855 mutex_init(&ev->block_mutex);
1857 ev->poll_msecs = -1;
1858 INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
1863 static void disk_add_events(struct gendisk *disk)
1868 /* FIXME: error handling */
1869 if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
1870 pr_warn("%s: failed to create sysfs files for events\n",
1873 mutex_lock(&disk_events_mutex);
1874 list_add_tail(&disk->ev->node, &disk_events);
1875 mutex_unlock(&disk_events_mutex);
1878 * Block count is initialized to 1 and the following initial
1879 * unblock kicks it into action.
1881 __disk_unblock_events(disk, true);
1884 static void disk_del_events(struct gendisk *disk)
1889 disk_block_events(disk);
1891 mutex_lock(&disk_events_mutex);
1892 list_del_init(&disk->ev->node);
1893 mutex_unlock(&disk_events_mutex);
1895 sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
1898 static void disk_release_events(struct gendisk *disk)
1900 /* the block count should be 1 from disk_del_events() */
1901 WARN_ON_ONCE(disk->ev && disk->ev->block != 1);