Merge branch 'batman-adv/maint' of git://git.open-mesh.org/linux-merge
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / block / genhd.c
blobe2f67902dd024ed2f07abdfc190c73558d2ddb7b
1 /*
2 * gendisk handling
3 */
5 #include <linux/module.h>
6 #include <linux/fs.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/init.h>
12 #include <linux/spinlock.h>
13 #include <linux/proc_fs.h>
14 #include <linux/seq_file.h>
15 #include <linux/slab.h>
16 #include <linux/kmod.h>
17 #include <linux/kobj_map.h>
18 #include <linux/buffer_head.h>
19 #include <linux/mutex.h>
20 #include <linux/idr.h>
21 #include <linux/log2.h>
23 #include "blk.h"
25 static DEFINE_MUTEX(block_class_lock);
26 struct kobject *block_depr;
28 /* for extended dynamic devt allocation, currently only one major is used */
29 #define MAX_EXT_DEVT (1 << MINORBITS)
31 /* For extended devt allocation. ext_devt_mutex prevents look up
32 * results from going away underneath its user.
34 static DEFINE_MUTEX(ext_devt_mutex);
35 static DEFINE_IDR(ext_devt_idr);
37 static struct device_type disk_type;
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 /**
44 * disk_get_part - get partition
45 * @disk: disk to look partition from
46 * @partno: partition number
48 * Look for partition @partno from @disk. If found, increment
49 * reference count and return it.
51 * CONTEXT:
52 * Don't care.
54 * RETURNS:
55 * Pointer to the found partition on success, NULL if not found.
57 struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
59 struct hd_struct *part = NULL;
60 struct disk_part_tbl *ptbl;
62 if (unlikely(partno < 0))
63 return NULL;
65 rcu_read_lock();
67 ptbl = rcu_dereference(disk->part_tbl);
68 if (likely(partno < ptbl->len)) {
69 part = rcu_dereference(ptbl->part[partno]);
70 if (part)
71 get_device(part_to_dev(part));
74 rcu_read_unlock();
76 return part;
78 EXPORT_SYMBOL_GPL(disk_get_part);
80 /**
81 * disk_part_iter_init - initialize partition iterator
82 * @piter: iterator to initialize
83 * @disk: disk to iterate over
84 * @flags: DISK_PITER_* flags
86 * Initialize @piter so that it iterates over partitions of @disk.
88 * CONTEXT:
89 * Don't care.
91 void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
92 unsigned int flags)
94 struct disk_part_tbl *ptbl;
96 rcu_read_lock();
97 ptbl = rcu_dereference(disk->part_tbl);
99 piter->disk = disk;
100 piter->part = NULL;
102 if (flags & DISK_PITER_REVERSE)
103 piter->idx = ptbl->len - 1;
104 else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
105 piter->idx = 0;
106 else
107 piter->idx = 1;
109 piter->flags = flags;
111 rcu_read_unlock();
113 EXPORT_SYMBOL_GPL(disk_part_iter_init);
116 * disk_part_iter_next - proceed iterator to the next partition and return it
117 * @piter: iterator of interest
119 * Proceed @piter to the next partition and return it.
121 * CONTEXT:
122 * Don't care.
124 struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
126 struct disk_part_tbl *ptbl;
127 int inc, end;
129 /* put the last partition */
130 disk_put_part(piter->part);
131 piter->part = NULL;
133 /* get part_tbl */
134 rcu_read_lock();
135 ptbl = rcu_dereference(piter->disk->part_tbl);
137 /* determine iteration parameters */
138 if (piter->flags & DISK_PITER_REVERSE) {
139 inc = -1;
140 if (piter->flags & (DISK_PITER_INCL_PART0 |
141 DISK_PITER_INCL_EMPTY_PART0))
142 end = -1;
143 else
144 end = 0;
145 } else {
146 inc = 1;
147 end = ptbl->len;
150 /* iterate to the next partition */
151 for (; piter->idx != end; piter->idx += inc) {
152 struct hd_struct *part;
154 part = rcu_dereference(ptbl->part[piter->idx]);
155 if (!part)
156 continue;
157 if (!part->nr_sects &&
158 !(piter->flags & DISK_PITER_INCL_EMPTY) &&
159 !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
160 piter->idx == 0))
161 continue;
163 get_device(part_to_dev(part));
164 piter->part = part;
165 piter->idx += inc;
166 break;
169 rcu_read_unlock();
171 return piter->part;
173 EXPORT_SYMBOL_GPL(disk_part_iter_next);
176 * disk_part_iter_exit - finish up partition iteration
177 * @piter: iter of interest
179 * Called when iteration is over. Cleans up @piter.
181 * CONTEXT:
182 * Don't care.
184 void disk_part_iter_exit(struct disk_part_iter *piter)
186 disk_put_part(piter->part);
187 piter->part = NULL;
189 EXPORT_SYMBOL_GPL(disk_part_iter_exit);
191 static inline int sector_in_part(struct hd_struct *part, sector_t sector)
193 return part->start_sect <= sector &&
194 sector < part->start_sect + part->nr_sects;
198 * disk_map_sector_rcu - map sector to partition
199 * @disk: gendisk of interest
200 * @sector: sector to map
202 * Find out which partition @sector maps to on @disk. This is
203 * primarily used for stats accounting.
205 * CONTEXT:
206 * RCU read locked. The returned partition pointer is valid only
207 * while preemption is disabled.
209 * RETURNS:
210 * Found partition on success, part0 is returned if no partition matches
212 struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
214 struct disk_part_tbl *ptbl;
215 struct hd_struct *part;
216 int i;
218 ptbl = rcu_dereference(disk->part_tbl);
220 part = rcu_dereference(ptbl->last_lookup);
221 if (part && sector_in_part(part, sector))
222 return part;
224 for (i = 1; i < ptbl->len; i++) {
225 part = rcu_dereference(ptbl->part[i]);
227 if (part && sector_in_part(part, sector)) {
228 rcu_assign_pointer(ptbl->last_lookup, part);
229 return part;
232 return &disk->part0;
234 EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
237 * Can be deleted altogether. Later.
240 static struct blk_major_name {
241 struct blk_major_name *next;
242 int major;
243 char name[16];
244 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
246 /* index in the above - for now: assume no multimajor ranges */
247 static inline int major_to_index(unsigned major)
249 return major % BLKDEV_MAJOR_HASH_SIZE;
252 #ifdef CONFIG_PROC_FS
253 void blkdev_show(struct seq_file *seqf, off_t offset)
255 struct blk_major_name *dp;
257 if (offset < BLKDEV_MAJOR_HASH_SIZE) {
258 mutex_lock(&block_class_lock);
259 for (dp = major_names[offset]; dp; dp = dp->next)
260 seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
261 mutex_unlock(&block_class_lock);
264 #endif /* CONFIG_PROC_FS */
267 * register_blkdev - register a new block device
269 * @major: the requested major device number [1..255]. If @major=0, try to
270 * allocate any unused major number.
271 * @name: the name of the new block device as a zero terminated string
273 * The @name must be unique within the system.
275 * The return value depends on the @major input parameter.
276 * - if a major device number was requested in range [1..255] then the
277 * function returns zero on success, or a negative error code
278 * - if any unused major number was requested with @major=0 parameter
279 * then the return value is the allocated major number in range
280 * [1..255] or a negative error code otherwise
282 int register_blkdev(unsigned int major, const char *name)
284 struct blk_major_name **n, *p;
285 int index, ret = 0;
287 mutex_lock(&block_class_lock);
289 /* temporary */
290 if (major == 0) {
291 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
292 if (major_names[index] == NULL)
293 break;
296 if (index == 0) {
297 printk("register_blkdev: failed to get major for %s\n",
298 name);
299 ret = -EBUSY;
300 goto out;
302 major = index;
303 ret = major;
306 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
307 if (p == NULL) {
308 ret = -ENOMEM;
309 goto out;
312 p->major = major;
313 strlcpy(p->name, name, sizeof(p->name));
314 p->next = NULL;
315 index = major_to_index(major);
317 for (n = &major_names[index]; *n; n = &(*n)->next) {
318 if ((*n)->major == major)
319 break;
321 if (!*n)
322 *n = p;
323 else
324 ret = -EBUSY;
326 if (ret < 0) {
327 printk("register_blkdev: cannot get major %d for %s\n",
328 major, name);
329 kfree(p);
331 out:
332 mutex_unlock(&block_class_lock);
333 return ret;
336 EXPORT_SYMBOL(register_blkdev);
338 void unregister_blkdev(unsigned int major, const char *name)
340 struct blk_major_name **n;
341 struct blk_major_name *p = NULL;
342 int index = major_to_index(major);
344 mutex_lock(&block_class_lock);
345 for (n = &major_names[index]; *n; n = &(*n)->next)
346 if ((*n)->major == major)
347 break;
348 if (!*n || strcmp((*n)->name, name)) {
349 WARN_ON(1);
350 } else {
351 p = *n;
352 *n = p->next;
354 mutex_unlock(&block_class_lock);
355 kfree(p);
358 EXPORT_SYMBOL(unregister_blkdev);
360 static struct kobj_map *bdev_map;
363 * blk_mangle_minor - scatter minor numbers apart
364 * @minor: minor number to mangle
366 * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
367 * is enabled. Mangling twice gives the original value.
369 * RETURNS:
370 * Mangled value.
372 * CONTEXT:
373 * Don't care.
375 static int blk_mangle_minor(int minor)
377 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
378 int i;
380 for (i = 0; i < MINORBITS / 2; i++) {
381 int low = minor & (1 << i);
382 int high = minor & (1 << (MINORBITS - 1 - i));
383 int distance = MINORBITS - 1 - 2 * i;
385 minor ^= low | high; /* clear both bits */
386 low <<= distance; /* swap the positions */
387 high >>= distance;
388 minor |= low | high; /* and set */
390 #endif
391 return minor;
395 * blk_alloc_devt - allocate a dev_t for a partition
396 * @part: partition to allocate dev_t for
397 * @devt: out parameter for resulting dev_t
399 * Allocate a dev_t for block device.
401 * RETURNS:
402 * 0 on success, allocated dev_t is returned in *@devt. -errno on
403 * failure.
405 * CONTEXT:
406 * Might sleep.
408 int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
410 struct gendisk *disk = part_to_disk(part);
411 int idx, rc;
413 /* in consecutive minor range? */
414 if (part->partno < disk->minors) {
415 *devt = MKDEV(disk->major, disk->first_minor + part->partno);
416 return 0;
419 /* allocate ext devt */
420 do {
421 if (!idr_pre_get(&ext_devt_idr, GFP_KERNEL))
422 return -ENOMEM;
423 rc = idr_get_new(&ext_devt_idr, part, &idx);
424 } while (rc == -EAGAIN);
426 if (rc)
427 return rc;
429 if (idx > MAX_EXT_DEVT) {
430 idr_remove(&ext_devt_idr, idx);
431 return -EBUSY;
434 *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
435 return 0;
439 * blk_free_devt - free a dev_t
440 * @devt: dev_t to free
442 * Free @devt which was allocated using blk_alloc_devt().
444 * CONTEXT:
445 * Might sleep.
447 void blk_free_devt(dev_t devt)
449 might_sleep();
451 if (devt == MKDEV(0, 0))
452 return;
454 if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
455 mutex_lock(&ext_devt_mutex);
456 idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
457 mutex_unlock(&ext_devt_mutex);
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);
467 } else
468 snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
470 return buf;
474 * Register device numbers dev..(dev+range-1)
475 * range must be nonzero
476 * The hash chain is sorted on range, so that subranges can override.
478 void blk_register_region(dev_t devt, unsigned long range, struct module *module,
479 struct kobject *(*probe)(dev_t, int *, void *),
480 int (*lock)(dev_t, void *), void *data)
482 kobj_map(bdev_map, devt, range, module, probe, lock, data);
485 EXPORT_SYMBOL(blk_register_region);
487 void blk_unregister_region(dev_t devt, unsigned long range)
489 kobj_unmap(bdev_map, devt, range);
492 EXPORT_SYMBOL(blk_unregister_region);
494 static struct kobject *exact_match(dev_t devt, int *partno, void *data)
496 struct gendisk *p = data;
498 return &disk_to_dev(p)->kobj;
501 static int exact_lock(dev_t devt, void *data)
503 struct gendisk *p = data;
505 if (!get_disk(p))
506 return -1;
507 return 0;
510 void register_disk(struct gendisk *disk)
512 struct device *ddev = disk_to_dev(disk);
513 struct block_device *bdev;
514 struct disk_part_iter piter;
515 struct hd_struct *part;
516 int err;
518 ddev->parent = disk->driverfs_dev;
520 dev_set_name(ddev, disk->disk_name);
522 /* delay uevents, until we scanned partition table */
523 dev_set_uevent_suppress(ddev, 1);
525 if (device_add(ddev))
526 return;
527 if (!sysfs_deprecated) {
528 err = sysfs_create_link(block_depr, &ddev->kobj,
529 kobject_name(&ddev->kobj));
530 if (err) {
531 device_del(ddev);
532 return;
535 disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
536 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
538 /* No minors to use for partitions */
539 if (!disk_partitionable(disk))
540 goto exit;
542 /* No such device (e.g., media were just removed) */
543 if (!get_capacity(disk))
544 goto exit;
546 bdev = bdget_disk(disk, 0);
547 if (!bdev)
548 goto exit;
550 bdev->bd_invalidated = 1;
551 err = blkdev_get(bdev, FMODE_READ, NULL);
552 if (err < 0)
553 goto exit;
554 blkdev_put(bdev, FMODE_READ);
556 exit:
557 /* announce disk after possible partitions are created */
558 dev_set_uevent_suppress(ddev, 0);
559 kobject_uevent(&ddev->kobj, KOBJ_ADD);
561 /* announce possible partitions */
562 disk_part_iter_init(&piter, disk, 0);
563 while ((part = disk_part_iter_next(&piter)))
564 kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
565 disk_part_iter_exit(&piter);
569 * add_disk - add partitioning information to kernel list
570 * @disk: per-device partitioning information
572 * This function registers the partitioning information in @disk
573 * with the kernel.
575 * FIXME: error handling
577 void add_disk(struct gendisk *disk)
579 struct backing_dev_info *bdi;
580 dev_t devt;
581 int retval;
583 /* minors == 0 indicates to use ext devt from part0 and should
584 * be accompanied with EXT_DEVT flag. Make sure all
585 * parameters make sense.
587 WARN_ON(disk->minors && !(disk->major || disk->first_minor));
588 WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT));
590 disk->flags |= GENHD_FL_UP;
592 retval = blk_alloc_devt(&disk->part0, &devt);
593 if (retval) {
594 WARN_ON(1);
595 return;
597 disk_to_dev(disk)->devt = devt;
599 /* ->major and ->first_minor aren't supposed to be
600 * dereferenced from here on, but set them just in case.
602 disk->major = MAJOR(devt);
603 disk->first_minor = MINOR(devt);
605 /* Register BDI before referencing it from bdev */
606 bdi = &disk->queue->backing_dev_info;
607 bdi_register_dev(bdi, disk_devt(disk));
609 blk_register_region(disk_devt(disk), disk->minors, NULL,
610 exact_match, exact_lock, disk);
611 register_disk(disk);
612 blk_register_queue(disk);
614 retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
615 "bdi");
616 WARN_ON(retval);
618 disk_add_events(disk);
620 EXPORT_SYMBOL(add_disk);
622 void del_gendisk(struct gendisk *disk)
624 struct disk_part_iter piter;
625 struct hd_struct *part;
627 disk_del_events(disk);
629 /* invalidate stuff */
630 disk_part_iter_init(&piter, disk,
631 DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
632 while ((part = disk_part_iter_next(&piter))) {
633 invalidate_partition(disk, part->partno);
634 delete_partition(disk, part->partno);
636 disk_part_iter_exit(&piter);
638 invalidate_partition(disk, 0);
639 blk_free_devt(disk_to_dev(disk)->devt);
640 set_capacity(disk, 0);
641 disk->flags &= ~GENHD_FL_UP;
643 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
644 bdi_unregister(&disk->queue->backing_dev_info);
645 blk_unregister_queue(disk);
646 blk_unregister_region(disk_devt(disk), disk->minors);
648 part_stat_set_all(&disk->part0, 0);
649 disk->part0.stamp = 0;
651 kobject_put(disk->part0.holder_dir);
652 kobject_put(disk->slave_dir);
653 disk->driverfs_dev = NULL;
654 if (!sysfs_deprecated)
655 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
656 device_del(disk_to_dev(disk));
658 EXPORT_SYMBOL(del_gendisk);
661 * get_gendisk - get partitioning information for a given device
662 * @devt: device to get partitioning information for
663 * @partno: returned partition index
665 * This function gets the structure containing partitioning
666 * information for the given device @devt.
668 struct gendisk *get_gendisk(dev_t devt, int *partno)
670 struct gendisk *disk = NULL;
672 if (MAJOR(devt) != BLOCK_EXT_MAJOR) {
673 struct kobject *kobj;
675 kobj = kobj_lookup(bdev_map, devt, partno);
676 if (kobj)
677 disk = dev_to_disk(kobj_to_dev(kobj));
678 } else {
679 struct hd_struct *part;
681 mutex_lock(&ext_devt_mutex);
682 part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
683 if (part && get_disk(part_to_disk(part))) {
684 *partno = part->partno;
685 disk = part_to_disk(part);
687 mutex_unlock(&ext_devt_mutex);
690 return disk;
692 EXPORT_SYMBOL(get_gendisk);
695 * bdget_disk - do bdget() by gendisk and partition number
696 * @disk: gendisk of interest
697 * @partno: partition number
699 * Find partition @partno from @disk, do bdget() on it.
701 * CONTEXT:
702 * Don't care.
704 * RETURNS:
705 * Resulting block_device on success, NULL on failure.
707 struct block_device *bdget_disk(struct gendisk *disk, int partno)
709 struct hd_struct *part;
710 struct block_device *bdev = NULL;
712 part = disk_get_part(disk, partno);
713 if (part)
714 bdev = bdget(part_devt(part));
715 disk_put_part(part);
717 return bdev;
719 EXPORT_SYMBOL(bdget_disk);
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
724 * went wrong
726 void __init printk_all_partitions(void)
728 struct class_dev_iter iter;
729 struct device *dev;
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 disk_part_iter piter;
735 struct hd_struct *part;
736 char name_buf[BDEVNAME_SIZE];
737 char devt_buf[BDEVT_SIZE];
738 u8 uuid[PARTITION_META_INFO_UUIDLTH * 2 + 1];
741 * Don't show empty devices or things that have been
742 * suppressed
744 if (get_capacity(disk) == 0 ||
745 (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
746 continue;
749 * Note, unlike /proc/partitions, I am showing the
750 * numbers in hex - the same format as the root=
751 * option takes.
753 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
754 while ((part = disk_part_iter_next(&piter))) {
755 bool is_part0 = part == &disk->part0;
757 uuid[0] = 0;
758 if (part->info)
759 part_unpack_uuid(part->info->uuid, uuid);
761 printk("%s%s %10llu %s %s", is_part0 ? "" : " ",
762 bdevt_str(part_devt(part), devt_buf),
763 (unsigned long long)part->nr_sects >> 1,
764 disk_name(disk, part->partno, name_buf), uuid);
765 if (is_part0) {
766 if (disk->driverfs_dev != NULL &&
767 disk->driverfs_dev->driver != NULL)
768 printk(" driver: %s\n",
769 disk->driverfs_dev->driver->name);
770 else
771 printk(" (driver?)\n");
772 } else
773 printk("\n");
775 disk_part_iter_exit(&piter);
777 class_dev_iter_exit(&iter);
780 #ifdef CONFIG_PROC_FS
781 /* iterator */
782 static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
784 loff_t skip = *pos;
785 struct class_dev_iter *iter;
786 struct device *dev;
788 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
789 if (!iter)
790 return ERR_PTR(-ENOMEM);
792 seqf->private = iter;
793 class_dev_iter_init(iter, &block_class, NULL, &disk_type);
794 do {
795 dev = class_dev_iter_next(iter);
796 if (!dev)
797 return NULL;
798 } while (skip--);
800 return dev_to_disk(dev);
803 static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
805 struct device *dev;
807 (*pos)++;
808 dev = class_dev_iter_next(seqf->private);
809 if (dev)
810 return dev_to_disk(dev);
812 return NULL;
815 static void disk_seqf_stop(struct seq_file *seqf, void *v)
817 struct class_dev_iter *iter = seqf->private;
819 /* stop is called even after start failed :-( */
820 if (iter) {
821 class_dev_iter_exit(iter);
822 kfree(iter);
826 static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
828 static void *p;
830 p = disk_seqf_start(seqf, pos);
831 if (!IS_ERR_OR_NULL(p) && !*pos)
832 seq_puts(seqf, "major minor #blocks name\n\n");
833 return p;
836 static int show_partition(struct seq_file *seqf, void *v)
838 struct gendisk *sgp = v;
839 struct disk_part_iter piter;
840 struct hd_struct *part;
841 char buf[BDEVNAME_SIZE];
843 /* Don't show non-partitionable removeable devices or empty devices */
844 if (!get_capacity(sgp) || (!disk_partitionable(sgp) &&
845 (sgp->flags & GENHD_FL_REMOVABLE)))
846 return 0;
847 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
848 return 0;
850 /* show the full disk and all non-0 size partitions of it */
851 disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
852 while ((part = disk_part_iter_next(&piter)))
853 seq_printf(seqf, "%4d %7d %10llu %s\n",
854 MAJOR(part_devt(part)), MINOR(part_devt(part)),
855 (unsigned long long)part->nr_sects >> 1,
856 disk_name(sgp, part->partno, buf));
857 disk_part_iter_exit(&piter);
859 return 0;
862 static const struct seq_operations partitions_op = {
863 .start = show_partition_start,
864 .next = disk_seqf_next,
865 .stop = disk_seqf_stop,
866 .show = show_partition
869 static int partitions_open(struct inode *inode, struct file *file)
871 return seq_open(file, &partitions_op);
874 static const struct file_operations proc_partitions_operations = {
875 .open = partitions_open,
876 .read = seq_read,
877 .llseek = seq_lseek,
878 .release = seq_release,
880 #endif
883 static struct kobject *base_probe(dev_t devt, int *partno, void *data)
885 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
886 /* Make old-style 2.4 aliases work */
887 request_module("block-major-%d", MAJOR(devt));
888 return NULL;
891 static int __init genhd_device_init(void)
893 int error;
895 block_class.dev_kobj = sysfs_dev_block_kobj;
896 error = class_register(&block_class);
897 if (unlikely(error))
898 return error;
899 bdev_map = kobj_map_init(base_probe, &block_class_lock);
900 blk_dev_init();
902 register_blkdev(BLOCK_EXT_MAJOR, "blkext");
904 /* create top-level block dir */
905 if (!sysfs_deprecated)
906 block_depr = kobject_create_and_add("block", NULL);
907 return 0;
910 subsys_initcall(genhd_device_init);
912 static ssize_t disk_range_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", disk->minors);
920 static ssize_t disk_ext_range_show(struct device *dev,
921 struct device_attribute *attr, char *buf)
923 struct gendisk *disk = dev_to_disk(dev);
925 return sprintf(buf, "%d\n", disk_max_parts(disk));
928 static ssize_t disk_removable_show(struct device *dev,
929 struct device_attribute *attr, char *buf)
931 struct gendisk *disk = dev_to_disk(dev);
933 return sprintf(buf, "%d\n",
934 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
937 static ssize_t disk_ro_show(struct device *dev,
938 struct device_attribute *attr, char *buf)
940 struct gendisk *disk = dev_to_disk(dev);
942 return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
945 static ssize_t disk_capability_show(struct device *dev,
946 struct device_attribute *attr, char *buf)
948 struct gendisk *disk = dev_to_disk(dev);
950 return sprintf(buf, "%x\n", disk->flags);
953 static ssize_t disk_alignment_offset_show(struct device *dev,
954 struct device_attribute *attr,
955 char *buf)
957 struct gendisk *disk = dev_to_disk(dev);
959 return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue));
962 static ssize_t disk_discard_alignment_show(struct device *dev,
963 struct device_attribute *attr,
964 char *buf)
966 struct gendisk *disk = dev_to_disk(dev);
968 return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
971 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
972 static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL);
973 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
974 static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
975 static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
976 static DEVICE_ATTR(alignment_offset, S_IRUGO, disk_alignment_offset_show, NULL);
977 static DEVICE_ATTR(discard_alignment, S_IRUGO, disk_discard_alignment_show,
978 NULL);
979 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
980 static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
981 static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
982 #ifdef CONFIG_FAIL_MAKE_REQUEST
983 static struct device_attribute dev_attr_fail =
984 __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
985 #endif
986 #ifdef CONFIG_FAIL_IO_TIMEOUT
987 static struct device_attribute dev_attr_fail_timeout =
988 __ATTR(io-timeout-fail, S_IRUGO|S_IWUSR, part_timeout_show,
989 part_timeout_store);
990 #endif
992 static struct attribute *disk_attrs[] = {
993 &dev_attr_range.attr,
994 &dev_attr_ext_range.attr,
995 &dev_attr_removable.attr,
996 &dev_attr_ro.attr,
997 &dev_attr_size.attr,
998 &dev_attr_alignment_offset.attr,
999 &dev_attr_discard_alignment.attr,
1000 &dev_attr_capability.attr,
1001 &dev_attr_stat.attr,
1002 &dev_attr_inflight.attr,
1003 #ifdef CONFIG_FAIL_MAKE_REQUEST
1004 &dev_attr_fail.attr,
1005 #endif
1006 #ifdef CONFIG_FAIL_IO_TIMEOUT
1007 &dev_attr_fail_timeout.attr,
1008 #endif
1009 NULL
1012 static struct attribute_group disk_attr_group = {
1013 .attrs = disk_attrs,
1016 static const struct attribute_group *disk_attr_groups[] = {
1017 &disk_attr_group,
1018 NULL
1022 * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
1023 * @disk: disk to replace part_tbl for
1024 * @new_ptbl: new part_tbl to install
1026 * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The
1027 * original ptbl is freed using RCU callback.
1029 * LOCKING:
1030 * Matching bd_mutx locked.
1032 static void disk_replace_part_tbl(struct gendisk *disk,
1033 struct disk_part_tbl *new_ptbl)
1035 struct disk_part_tbl *old_ptbl = disk->part_tbl;
1037 rcu_assign_pointer(disk->part_tbl, new_ptbl);
1039 if (old_ptbl) {
1040 rcu_assign_pointer(old_ptbl->last_lookup, NULL);
1041 kfree_rcu(old_ptbl, rcu_head);
1046 * disk_expand_part_tbl - expand disk->part_tbl
1047 * @disk: disk to expand part_tbl for
1048 * @partno: expand such that this partno can fit in
1050 * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl
1051 * uses RCU to allow unlocked dereferencing for stats and other stuff.
1053 * LOCKING:
1054 * Matching bd_mutex locked, might sleep.
1056 * RETURNS:
1057 * 0 on success, -errno on failure.
1059 int disk_expand_part_tbl(struct gendisk *disk, int partno)
1061 struct disk_part_tbl *old_ptbl = disk->part_tbl;
1062 struct disk_part_tbl *new_ptbl;
1063 int len = old_ptbl ? old_ptbl->len : 0;
1064 int target = partno + 1;
1065 size_t size;
1066 int i;
1068 /* disk_max_parts() is zero during initialization, ignore if so */
1069 if (disk_max_parts(disk) && target > disk_max_parts(disk))
1070 return -EINVAL;
1072 if (target <= len)
1073 return 0;
1075 size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]);
1076 new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id);
1077 if (!new_ptbl)
1078 return -ENOMEM;
1080 new_ptbl->len = target;
1082 for (i = 0; i < len; i++)
1083 rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
1085 disk_replace_part_tbl(disk, new_ptbl);
1086 return 0;
1089 static void disk_release(struct device *dev)
1091 struct gendisk *disk = dev_to_disk(dev);
1093 disk_release_events(disk);
1094 kfree(disk->random);
1095 disk_replace_part_tbl(disk, NULL);
1096 free_part_stats(&disk->part0);
1097 free_part_info(&disk->part0);
1098 kfree(disk);
1100 struct class block_class = {
1101 .name = "block",
1104 static char *block_devnode(struct device *dev, mode_t *mode)
1106 struct gendisk *disk = dev_to_disk(dev);
1108 if (disk->devnode)
1109 return disk->devnode(disk, mode);
1110 return NULL;
1113 static struct device_type disk_type = {
1114 .name = "disk",
1115 .groups = disk_attr_groups,
1116 .release = disk_release,
1117 .devnode = block_devnode,
1120 #ifdef CONFIG_PROC_FS
1122 * aggregate disk stat collector. Uses the same stats that the sysfs
1123 * entries do, above, but makes them available through one seq_file.
1125 * The output looks suspiciously like /proc/partitions with a bunch of
1126 * extra fields.
1128 static int diskstats_show(struct seq_file *seqf, void *v)
1130 struct gendisk *gp = v;
1131 struct disk_part_iter piter;
1132 struct hd_struct *hd;
1133 char buf[BDEVNAME_SIZE];
1134 int cpu;
1137 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1138 seq_puts(seqf, "major minor name"
1139 " rio rmerge rsect ruse wio wmerge "
1140 "wsect wuse running use aveq"
1141 "\n\n");
1144 disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
1145 while ((hd = disk_part_iter_next(&piter))) {
1146 cpu = part_stat_lock();
1147 part_round_stats(cpu, hd);
1148 part_stat_unlock();
1149 seq_printf(seqf, "%4d %7d %s %lu %lu %lu "
1150 "%u %lu %lu %lu %u %u %u %u\n",
1151 MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
1152 disk_name(gp, hd->partno, buf),
1153 part_stat_read(hd, ios[READ]),
1154 part_stat_read(hd, merges[READ]),
1155 part_stat_read(hd, sectors[READ]),
1156 jiffies_to_msecs(part_stat_read(hd, ticks[READ])),
1157 part_stat_read(hd, ios[WRITE]),
1158 part_stat_read(hd, merges[WRITE]),
1159 part_stat_read(hd, sectors[WRITE]),
1160 jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])),
1161 part_in_flight(hd),
1162 jiffies_to_msecs(part_stat_read(hd, io_ticks)),
1163 jiffies_to_msecs(part_stat_read(hd, time_in_queue))
1166 disk_part_iter_exit(&piter);
1168 return 0;
1171 static const struct seq_operations diskstats_op = {
1172 .start = disk_seqf_start,
1173 .next = disk_seqf_next,
1174 .stop = disk_seqf_stop,
1175 .show = diskstats_show
1178 static int diskstats_open(struct inode *inode, struct file *file)
1180 return seq_open(file, &diskstats_op);
1183 static const struct file_operations proc_diskstats_operations = {
1184 .open = diskstats_open,
1185 .read = seq_read,
1186 .llseek = seq_lseek,
1187 .release = seq_release,
1190 static int __init proc_genhd_init(void)
1192 proc_create("diskstats", 0, NULL, &proc_diskstats_operations);
1193 proc_create("partitions", 0, NULL, &proc_partitions_operations);
1194 return 0;
1196 module_init(proc_genhd_init);
1197 #endif /* CONFIG_PROC_FS */
1199 dev_t blk_lookup_devt(const char *name, int partno)
1201 dev_t devt = MKDEV(0, 0);
1202 struct class_dev_iter iter;
1203 struct device *dev;
1205 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
1206 while ((dev = class_dev_iter_next(&iter))) {
1207 struct gendisk *disk = dev_to_disk(dev);
1208 struct hd_struct *part;
1210 if (strcmp(dev_name(dev), name))
1211 continue;
1213 if (partno < disk->minors) {
1214 /* We need to return the right devno, even
1215 * if the partition doesn't exist yet.
1217 devt = MKDEV(MAJOR(dev->devt),
1218 MINOR(dev->devt) + partno);
1219 break;
1221 part = disk_get_part(disk, partno);
1222 if (part) {
1223 devt = part_devt(part);
1224 disk_put_part(part);
1225 break;
1227 disk_put_part(part);
1229 class_dev_iter_exit(&iter);
1230 return devt;
1232 EXPORT_SYMBOL(blk_lookup_devt);
1234 struct gendisk *alloc_disk(int minors)
1236 return alloc_disk_node(minors, -1);
1238 EXPORT_SYMBOL(alloc_disk);
1240 struct gendisk *alloc_disk_node(int minors, int node_id)
1242 struct gendisk *disk;
1244 disk = kmalloc_node(sizeof(struct gendisk),
1245 GFP_KERNEL | __GFP_ZERO, node_id);
1246 if (disk) {
1247 if (!init_part_stats(&disk->part0)) {
1248 kfree(disk);
1249 return NULL;
1251 disk->node_id = node_id;
1252 if (disk_expand_part_tbl(disk, 0)) {
1253 free_part_stats(&disk->part0);
1254 kfree(disk);
1255 return NULL;
1257 disk->part_tbl->part[0] = &disk->part0;
1259 hd_ref_init(&disk->part0);
1261 disk->minors = minors;
1262 rand_initialize_disk(disk);
1263 disk_to_dev(disk)->class = &block_class;
1264 disk_to_dev(disk)->type = &disk_type;
1265 device_initialize(disk_to_dev(disk));
1267 return disk;
1269 EXPORT_SYMBOL(alloc_disk_node);
1271 struct kobject *get_disk(struct gendisk *disk)
1273 struct module *owner;
1274 struct kobject *kobj;
1276 if (!disk->fops)
1277 return NULL;
1278 owner = disk->fops->owner;
1279 if (owner && !try_module_get(owner))
1280 return NULL;
1281 kobj = kobject_get(&disk_to_dev(disk)->kobj);
1282 if (kobj == NULL) {
1283 module_put(owner);
1284 return NULL;
1286 return kobj;
1290 EXPORT_SYMBOL(get_disk);
1292 void put_disk(struct gendisk *disk)
1294 if (disk)
1295 kobject_put(&disk_to_dev(disk)->kobj);
1298 EXPORT_SYMBOL(put_disk);
1300 static void set_disk_ro_uevent(struct gendisk *gd, int ro)
1302 char event[] = "DISK_RO=1";
1303 char *envp[] = { event, NULL };
1305 if (!ro)
1306 event[8] = '0';
1307 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
1310 void set_device_ro(struct block_device *bdev, int flag)
1312 bdev->bd_part->policy = flag;
1315 EXPORT_SYMBOL(set_device_ro);
1317 void set_disk_ro(struct gendisk *disk, int flag)
1319 struct disk_part_iter piter;
1320 struct hd_struct *part;
1322 if (disk->part0.policy != flag) {
1323 set_disk_ro_uevent(disk, flag);
1324 disk->part0.policy = flag;
1327 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
1328 while ((part = disk_part_iter_next(&piter)))
1329 part->policy = flag;
1330 disk_part_iter_exit(&piter);
1333 EXPORT_SYMBOL(set_disk_ro);
1335 int bdev_read_only(struct block_device *bdev)
1337 if (!bdev)
1338 return 0;
1339 return bdev->bd_part->policy;
1342 EXPORT_SYMBOL(bdev_read_only);
1344 int invalidate_partition(struct gendisk *disk, int partno)
1346 int res = 0;
1347 struct block_device *bdev = bdget_disk(disk, partno);
1348 if (bdev) {
1349 fsync_bdev(bdev);
1350 res = __invalidate_device(bdev, true);
1351 bdput(bdev);
1353 return res;
1356 EXPORT_SYMBOL(invalidate_partition);
1359 * Disk events - monitor disk events like media change and eject request.
1361 struct disk_events {
1362 struct list_head node; /* all disk_event's */
1363 struct gendisk *disk; /* the associated disk */
1364 spinlock_t lock;
1366 struct mutex block_mutex; /* protects blocking */
1367 int block; /* event blocking depth */
1368 unsigned int pending; /* events already sent out */
1369 unsigned int clearing; /* events being cleared */
1371 long poll_msecs; /* interval, -1 for default */
1372 struct delayed_work dwork;
1375 static const char *disk_events_strs[] = {
1376 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
1377 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
1380 static char *disk_uevents[] = {
1381 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
1382 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
1385 /* list of all disk_events */
1386 static DEFINE_MUTEX(disk_events_mutex);
1387 static LIST_HEAD(disk_events);
1389 /* disable in-kernel polling by default */
1390 static unsigned long disk_events_dfl_poll_msecs = 0;
1392 static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
1394 struct disk_events *ev = disk->ev;
1395 long intv_msecs = 0;
1398 * If device-specific poll interval is set, always use it. If
1399 * the default is being used, poll iff there are events which
1400 * can't be monitored asynchronously.
1402 if (ev->poll_msecs >= 0)
1403 intv_msecs = ev->poll_msecs;
1404 else if (disk->events & ~disk->async_events)
1405 intv_msecs = disk_events_dfl_poll_msecs;
1407 return msecs_to_jiffies(intv_msecs);
1411 * disk_block_events - block and flush disk event checking
1412 * @disk: disk to block events for
1414 * On return from this function, it is guaranteed that event checking
1415 * isn't in progress and won't happen until unblocked by
1416 * disk_unblock_events(). Events blocking is counted and the actual
1417 * unblocking happens after the matching number of unblocks are done.
1419 * Note that this intentionally does not block event checking from
1420 * disk_clear_events().
1422 * CONTEXT:
1423 * Might sleep.
1425 void disk_block_events(struct gendisk *disk)
1427 struct disk_events *ev = disk->ev;
1428 unsigned long flags;
1429 bool cancel;
1431 if (!ev)
1432 return;
1435 * Outer mutex ensures that the first blocker completes canceling
1436 * the event work before further blockers are allowed to finish.
1438 mutex_lock(&ev->block_mutex);
1440 spin_lock_irqsave(&ev->lock, flags);
1441 cancel = !ev->block++;
1442 spin_unlock_irqrestore(&ev->lock, flags);
1444 if (cancel)
1445 cancel_delayed_work_sync(&disk->ev->dwork);
1447 mutex_unlock(&ev->block_mutex);
1450 static void __disk_unblock_events(struct gendisk *disk, bool check_now)
1452 struct disk_events *ev = disk->ev;
1453 unsigned long intv;
1454 unsigned long flags;
1456 spin_lock_irqsave(&ev->lock, flags);
1458 if (WARN_ON_ONCE(ev->block <= 0))
1459 goto out_unlock;
1461 if (--ev->block)
1462 goto out_unlock;
1465 * Not exactly a latency critical operation, set poll timer
1466 * slack to 25% and kick event check.
1468 intv = disk_events_poll_jiffies(disk);
1469 set_timer_slack(&ev->dwork.timer, intv / 4);
1470 if (check_now)
1471 queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
1472 else if (intv)
1473 queue_delayed_work(system_nrt_wq, &ev->dwork, intv);
1474 out_unlock:
1475 spin_unlock_irqrestore(&ev->lock, flags);
1479 * disk_unblock_events - unblock disk event checking
1480 * @disk: disk to unblock events for
1482 * Undo disk_block_events(). When the block count reaches zero, it
1483 * starts events polling if configured.
1485 * CONTEXT:
1486 * Don't care. Safe to call from irq context.
1488 void disk_unblock_events(struct gendisk *disk)
1490 if (disk->ev)
1491 __disk_unblock_events(disk, false);
1495 * disk_flush_events - schedule immediate event checking and flushing
1496 * @disk: disk to check and flush events for
1497 * @mask: events to flush
1499 * Schedule immediate event checking on @disk if not blocked. Events in
1500 * @mask are scheduled to be cleared from the driver. Note that this
1501 * doesn't clear the events from @disk->ev.
1503 * CONTEXT:
1504 * If @mask is non-zero must be called with bdev->bd_mutex held.
1506 void disk_flush_events(struct gendisk *disk, unsigned int mask)
1508 struct disk_events *ev = disk->ev;
1510 if (!ev)
1511 return;
1513 spin_lock_irq(&ev->lock);
1514 ev->clearing |= mask;
1515 if (!ev->block) {
1516 cancel_delayed_work(&ev->dwork);
1517 queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
1519 spin_unlock_irq(&ev->lock);
1523 * disk_clear_events - synchronously check, clear and return pending events
1524 * @disk: disk to fetch and clear events from
1525 * @mask: mask of events to be fetched and clearted
1527 * Disk events are synchronously checked and pending events in @mask
1528 * are cleared and returned. This ignores the block count.
1530 * CONTEXT:
1531 * Might sleep.
1533 unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
1535 const struct block_device_operations *bdops = disk->fops;
1536 struct disk_events *ev = disk->ev;
1537 unsigned int pending;
1539 if (!ev) {
1540 /* for drivers still using the old ->media_changed method */
1541 if ((mask & DISK_EVENT_MEDIA_CHANGE) &&
1542 bdops->media_changed && bdops->media_changed(disk))
1543 return DISK_EVENT_MEDIA_CHANGE;
1544 return 0;
1547 /* tell the workfn about the events being cleared */
1548 spin_lock_irq(&ev->lock);
1549 ev->clearing |= mask;
1550 spin_unlock_irq(&ev->lock);
1552 /* uncondtionally schedule event check and wait for it to finish */
1553 disk_block_events(disk);
1554 queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
1555 flush_delayed_work(&ev->dwork);
1556 __disk_unblock_events(disk, false);
1558 /* then, fetch and clear pending events */
1559 spin_lock_irq(&ev->lock);
1560 WARN_ON_ONCE(ev->clearing & mask); /* cleared by workfn */
1561 pending = ev->pending & mask;
1562 ev->pending &= ~mask;
1563 spin_unlock_irq(&ev->lock);
1565 return pending;
1568 static void disk_events_workfn(struct work_struct *work)
1570 struct delayed_work *dwork = to_delayed_work(work);
1571 struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
1572 struct gendisk *disk = ev->disk;
1573 char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
1574 unsigned int clearing = ev->clearing;
1575 unsigned int events;
1576 unsigned long intv;
1577 int nr_events = 0, i;
1579 /* check events */
1580 events = disk->fops->check_events(disk, clearing);
1582 /* accumulate pending events and schedule next poll if necessary */
1583 spin_lock_irq(&ev->lock);
1585 events &= ~ev->pending;
1586 ev->pending |= events;
1587 ev->clearing &= ~clearing;
1589 intv = disk_events_poll_jiffies(disk);
1590 if (!ev->block && intv)
1591 queue_delayed_work(system_nrt_wq, &ev->dwork, intv);
1593 spin_unlock_irq(&ev->lock);
1596 * Tell userland about new events. Only the events listed in
1597 * @disk->events are reported. Unlisted events are processed the
1598 * same internally but never get reported to userland.
1600 for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
1601 if (events & disk->events & (1 << i))
1602 envp[nr_events++] = disk_uevents[i];
1604 if (nr_events)
1605 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
1609 * A disk events enabled device has the following sysfs nodes under
1610 * its /sys/block/X/ directory.
1612 * events : list of all supported events
1613 * events_async : list of events which can be detected w/o polling
1614 * events_poll_msecs : polling interval, 0: disable, -1: system default
1616 static ssize_t __disk_events_show(unsigned int events, char *buf)
1618 const char *delim = "";
1619 ssize_t pos = 0;
1620 int i;
1622 for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
1623 if (events & (1 << i)) {
1624 pos += sprintf(buf + pos, "%s%s",
1625 delim, disk_events_strs[i]);
1626 delim = " ";
1628 if (pos)
1629 pos += sprintf(buf + pos, "\n");
1630 return pos;
1633 static ssize_t disk_events_show(struct device *dev,
1634 struct device_attribute *attr, char *buf)
1636 struct gendisk *disk = dev_to_disk(dev);
1638 return __disk_events_show(disk->events, buf);
1641 static ssize_t disk_events_async_show(struct device *dev,
1642 struct device_attribute *attr, char *buf)
1644 struct gendisk *disk = dev_to_disk(dev);
1646 return __disk_events_show(disk->async_events, buf);
1649 static ssize_t disk_events_poll_msecs_show(struct device *dev,
1650 struct device_attribute *attr,
1651 char *buf)
1653 struct gendisk *disk = dev_to_disk(dev);
1655 return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
1658 static ssize_t disk_events_poll_msecs_store(struct device *dev,
1659 struct device_attribute *attr,
1660 const char *buf, size_t count)
1662 struct gendisk *disk = dev_to_disk(dev);
1663 long intv;
1665 if (!count || !sscanf(buf, "%ld", &intv))
1666 return -EINVAL;
1668 if (intv < 0 && intv != -1)
1669 return -EINVAL;
1671 disk_block_events(disk);
1672 disk->ev->poll_msecs = intv;
1673 __disk_unblock_events(disk, true);
1675 return count;
1678 static const DEVICE_ATTR(events, S_IRUGO, disk_events_show, NULL);
1679 static const DEVICE_ATTR(events_async, S_IRUGO, disk_events_async_show, NULL);
1680 static const DEVICE_ATTR(events_poll_msecs, S_IRUGO|S_IWUSR,
1681 disk_events_poll_msecs_show,
1682 disk_events_poll_msecs_store);
1684 static const struct attribute *disk_events_attrs[] = {
1685 &dev_attr_events.attr,
1686 &dev_attr_events_async.attr,
1687 &dev_attr_events_poll_msecs.attr,
1688 NULL,
1692 * The default polling interval can be specified by the kernel
1693 * parameter block.events_dfl_poll_msecs which defaults to 0
1694 * (disable). This can also be modified runtime by writing to
1695 * /sys/module/block/events_dfl_poll_msecs.
1697 static int disk_events_set_dfl_poll_msecs(const char *val,
1698 const struct kernel_param *kp)
1700 struct disk_events *ev;
1701 int ret;
1703 ret = param_set_ulong(val, kp);
1704 if (ret < 0)
1705 return ret;
1707 mutex_lock(&disk_events_mutex);
1709 list_for_each_entry(ev, &disk_events, node)
1710 disk_flush_events(ev->disk, 0);
1712 mutex_unlock(&disk_events_mutex);
1714 return 0;
1717 static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
1718 .set = disk_events_set_dfl_poll_msecs,
1719 .get = param_get_ulong,
1722 #undef MODULE_PARAM_PREFIX
1723 #define MODULE_PARAM_PREFIX "block."
1725 module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
1726 &disk_events_dfl_poll_msecs, 0644);
1729 * disk_{add|del|release}_events - initialize and destroy disk_events.
1731 static void disk_add_events(struct gendisk *disk)
1733 struct disk_events *ev;
1735 if (!disk->fops->check_events)
1736 return;
1738 ev = kzalloc(sizeof(*ev), GFP_KERNEL);
1739 if (!ev) {
1740 pr_warn("%s: failed to initialize events\n", disk->disk_name);
1741 return;
1744 if (sysfs_create_files(&disk_to_dev(disk)->kobj,
1745 disk_events_attrs) < 0) {
1746 pr_warn("%s: failed to create sysfs files for events\n",
1747 disk->disk_name);
1748 kfree(ev);
1749 return;
1752 disk->ev = ev;
1754 INIT_LIST_HEAD(&ev->node);
1755 ev->disk = disk;
1756 spin_lock_init(&ev->lock);
1757 mutex_init(&ev->block_mutex);
1758 ev->block = 1;
1759 ev->poll_msecs = -1;
1760 INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
1762 mutex_lock(&disk_events_mutex);
1763 list_add_tail(&ev->node, &disk_events);
1764 mutex_unlock(&disk_events_mutex);
1767 * Block count is initialized to 1 and the following initial
1768 * unblock kicks it into action.
1770 __disk_unblock_events(disk, true);
1773 static void disk_del_events(struct gendisk *disk)
1775 if (!disk->ev)
1776 return;
1778 disk_block_events(disk);
1780 mutex_lock(&disk_events_mutex);
1781 list_del_init(&disk->ev->node);
1782 mutex_unlock(&disk_events_mutex);
1784 sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
1787 static void disk_release_events(struct gendisk *disk)
1789 /* the block count should be 1 from disk_del_events() */
1790 WARN_ON_ONCE(disk->ev && disk->ev->block != 1);
1791 kfree(disk->ev);