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/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>
24 static DEFINE_MUTEX(block_class_lock
);
25 #ifndef CONFIG_SYSFS_DEPRECATED
26 struct kobject
*block_depr
;
29 /* for extended dynamic devt allocation, currently only one major is used */
30 #define MAX_EXT_DEVT (1 << MINORBITS)
32 /* For extended devt allocation. ext_devt_mutex prevents look up
33 * results from going away underneath its user.
35 static DEFINE_MUTEX(ext_devt_mutex
);
36 static DEFINE_IDR(ext_devt_idr
);
38 static struct device_type disk_type
;
41 * disk_get_part - get partition
42 * @disk: disk to look partition from
43 * @partno: partition number
45 * Look for partition @partno from @disk. If found, increment
46 * reference count and return it.
52 * Pointer to the found partition on success, NULL if not found.
54 struct hd_struct
*disk_get_part(struct gendisk
*disk
, int partno
)
56 struct hd_struct
*part
= NULL
;
57 struct disk_part_tbl
*ptbl
;
59 if (unlikely(partno
< 0))
64 ptbl
= rcu_dereference(disk
->part_tbl
);
65 if (likely(partno
< ptbl
->len
)) {
66 part
= rcu_dereference(ptbl
->part
[partno
]);
68 get_device(part_to_dev(part
));
75 EXPORT_SYMBOL_GPL(disk_get_part
);
78 * disk_part_iter_init - initialize partition iterator
79 * @piter: iterator to initialize
80 * @disk: disk to iterate over
81 * @flags: DISK_PITER_* flags
83 * Initialize @piter so that it iterates over partitions of @disk.
88 void disk_part_iter_init(struct disk_part_iter
*piter
, struct gendisk
*disk
,
91 struct disk_part_tbl
*ptbl
;
94 ptbl
= rcu_dereference(disk
->part_tbl
);
99 if (flags
& DISK_PITER_REVERSE
)
100 piter
->idx
= ptbl
->len
- 1;
101 else if (flags
& (DISK_PITER_INCL_PART0
| DISK_PITER_INCL_EMPTY_PART0
))
106 piter
->flags
= flags
;
110 EXPORT_SYMBOL_GPL(disk_part_iter_init
);
113 * disk_part_iter_next - proceed iterator to the next partition and return it
114 * @piter: iterator of interest
116 * Proceed @piter to the next partition and return it.
121 struct hd_struct
*disk_part_iter_next(struct disk_part_iter
*piter
)
123 struct disk_part_tbl
*ptbl
;
126 /* put the last partition */
127 disk_put_part(piter
->part
);
132 ptbl
= rcu_dereference(piter
->disk
->part_tbl
);
134 /* determine iteration parameters */
135 if (piter
->flags
& DISK_PITER_REVERSE
) {
137 if (piter
->flags
& (DISK_PITER_INCL_PART0
|
138 DISK_PITER_INCL_EMPTY_PART0
))
147 /* iterate to the next partition */
148 for (; piter
->idx
!= end
; piter
->idx
+= inc
) {
149 struct hd_struct
*part
;
151 part
= rcu_dereference(ptbl
->part
[piter
->idx
]);
154 if (!part
->nr_sects
&&
155 !(piter
->flags
& DISK_PITER_INCL_EMPTY
) &&
156 !(piter
->flags
& DISK_PITER_INCL_EMPTY_PART0
&&
160 get_device(part_to_dev(part
));
170 EXPORT_SYMBOL_GPL(disk_part_iter_next
);
173 * disk_part_iter_exit - finish up partition iteration
174 * @piter: iter of interest
176 * Called when iteration is over. Cleans up @piter.
181 void disk_part_iter_exit(struct disk_part_iter
*piter
)
183 disk_put_part(piter
->part
);
186 EXPORT_SYMBOL_GPL(disk_part_iter_exit
);
188 static inline int sector_in_part(struct hd_struct
*part
, sector_t sector
)
190 return part
->start_sect
<= sector
&&
191 sector
< part
->start_sect
+ part
->nr_sects
;
195 * disk_map_sector_rcu - map sector to partition
196 * @disk: gendisk of interest
197 * @sector: sector to map
199 * Find out which partition @sector maps to on @disk. This is
200 * primarily used for stats accounting.
203 * RCU read locked. The returned partition pointer is valid only
204 * while preemption is disabled.
207 * Found partition on success, part0 is returned if no partition matches
209 struct hd_struct
*disk_map_sector_rcu(struct gendisk
*disk
, sector_t sector
)
211 struct disk_part_tbl
*ptbl
;
212 struct hd_struct
*part
;
215 ptbl
= rcu_dereference(disk
->part_tbl
);
217 part
= rcu_dereference(ptbl
->last_lookup
);
218 if (part
&& sector_in_part(part
, sector
))
221 for (i
= 1; i
< ptbl
->len
; i
++) {
222 part
= rcu_dereference(ptbl
->part
[i
]);
224 if (part
&& sector_in_part(part
, sector
)) {
225 rcu_assign_pointer(ptbl
->last_lookup
, part
);
231 EXPORT_SYMBOL_GPL(disk_map_sector_rcu
);
234 * Can be deleted altogether. Later.
237 static struct blk_major_name
{
238 struct blk_major_name
*next
;
241 } *major_names
[BLKDEV_MAJOR_HASH_SIZE
];
243 /* index in the above - for now: assume no multimajor ranges */
244 static inline int major_to_index(int major
)
246 return major
% BLKDEV_MAJOR_HASH_SIZE
;
249 #ifdef CONFIG_PROC_FS
250 void blkdev_show(struct seq_file
*seqf
, off_t offset
)
252 struct blk_major_name
*dp
;
254 if (offset
< BLKDEV_MAJOR_HASH_SIZE
) {
255 mutex_lock(&block_class_lock
);
256 for (dp
= major_names
[offset
]; dp
; dp
= dp
->next
)
257 seq_printf(seqf
, "%3d %s\n", dp
->major
, dp
->name
);
258 mutex_unlock(&block_class_lock
);
261 #endif /* CONFIG_PROC_FS */
264 * register_blkdev - register a new block device
266 * @major: the requested major device number [1..255]. If @major=0, try to
267 * allocate any unused major number.
268 * @name: the name of the new block device as a zero terminated string
270 * The @name must be unique within the system.
272 * The return value depends on the @major input parameter.
273 * - if a major device number was requested in range [1..255] then the
274 * function returns zero on success, or a negative error code
275 * - if any unused major number was requested with @major=0 parameter
276 * then the return value is the allocated major number in range
277 * [1..255] or a negative error code otherwise
279 int register_blkdev(unsigned int major
, const char *name
)
281 struct blk_major_name
**n
, *p
;
284 mutex_lock(&block_class_lock
);
288 for (index
= ARRAY_SIZE(major_names
)-1; index
> 0; index
--) {
289 if (major_names
[index
] == NULL
)
294 printk("register_blkdev: failed to get major for %s\n",
303 p
= kmalloc(sizeof(struct blk_major_name
), GFP_KERNEL
);
310 strlcpy(p
->name
, name
, sizeof(p
->name
));
312 index
= major_to_index(major
);
314 for (n
= &major_names
[index
]; *n
; n
= &(*n
)->next
) {
315 if ((*n
)->major
== major
)
324 printk("register_blkdev: cannot get major %d for %s\n",
329 mutex_unlock(&block_class_lock
);
333 EXPORT_SYMBOL(register_blkdev
);
335 void unregister_blkdev(unsigned int major
, const char *name
)
337 struct blk_major_name
**n
;
338 struct blk_major_name
*p
= NULL
;
339 int index
= major_to_index(major
);
341 mutex_lock(&block_class_lock
);
342 for (n
= &major_names
[index
]; *n
; n
= &(*n
)->next
)
343 if ((*n
)->major
== major
)
345 if (!*n
|| strcmp((*n
)->name
, name
)) {
351 mutex_unlock(&block_class_lock
);
355 EXPORT_SYMBOL(unregister_blkdev
);
357 static struct kobj_map
*bdev_map
;
360 * blk_mangle_minor - scatter minor numbers apart
361 * @minor: minor number to mangle
363 * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
364 * is enabled. Mangling twice gives the original value.
372 static int blk_mangle_minor(int minor
)
374 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
377 for (i
= 0; i
< MINORBITS
/ 2; i
++) {
378 int low
= minor
& (1 << i
);
379 int high
= minor
& (1 << (MINORBITS
- 1 - i
));
380 int distance
= MINORBITS
- 1 - 2 * i
;
382 minor
^= low
| high
; /* clear both bits */
383 low
<<= distance
; /* swap the positions */
385 minor
|= low
| high
; /* and set */
392 * blk_alloc_devt - allocate a dev_t for a partition
393 * @part: partition to allocate dev_t for
394 * @devt: out parameter for resulting dev_t
396 * Allocate a dev_t for block device.
399 * 0 on success, allocated dev_t is returned in *@devt. -errno on
405 int blk_alloc_devt(struct hd_struct
*part
, dev_t
*devt
)
407 struct gendisk
*disk
= part_to_disk(part
);
410 /* in consecutive minor range? */
411 if (part
->partno
< disk
->minors
) {
412 *devt
= MKDEV(disk
->major
, disk
->first_minor
+ part
->partno
);
416 /* allocate ext devt */
418 if (!idr_pre_get(&ext_devt_idr
, GFP_KERNEL
))
420 rc
= idr_get_new(&ext_devt_idr
, part
, &idx
);
421 } while (rc
== -EAGAIN
);
426 if (idx
> MAX_EXT_DEVT
) {
427 idr_remove(&ext_devt_idr
, idx
);
431 *devt
= MKDEV(BLOCK_EXT_MAJOR
, blk_mangle_minor(idx
));
436 * blk_free_devt - free a dev_t
437 * @devt: dev_t to free
439 * Free @devt which was allocated using blk_alloc_devt().
444 void blk_free_devt(dev_t devt
)
448 if (devt
== MKDEV(0, 0))
451 if (MAJOR(devt
) == BLOCK_EXT_MAJOR
) {
452 mutex_lock(&ext_devt_mutex
);
453 idr_remove(&ext_devt_idr
, blk_mangle_minor(MINOR(devt
)));
454 mutex_unlock(&ext_devt_mutex
);
458 static char *bdevt_str(dev_t devt
, char *buf
)
460 if (MAJOR(devt
) <= 0xff && MINOR(devt
) <= 0xff) {
461 char tbuf
[BDEVT_SIZE
];
462 snprintf(tbuf
, BDEVT_SIZE
, "%02x%02x", MAJOR(devt
), MINOR(devt
));
463 snprintf(buf
, BDEVT_SIZE
, "%-9s", tbuf
);
465 snprintf(buf
, BDEVT_SIZE
, "%03x:%05x", MAJOR(devt
), MINOR(devt
));
471 * Register device numbers dev..(dev+range-1)
472 * range must be nonzero
473 * The hash chain is sorted on range, so that subranges can override.
475 void blk_register_region(dev_t devt
, unsigned long range
, struct module
*module
,
476 struct kobject
*(*probe
)(dev_t
, int *, void *),
477 int (*lock
)(dev_t
, void *), void *data
)
479 kobj_map(bdev_map
, devt
, range
, module
, probe
, lock
, data
);
482 EXPORT_SYMBOL(blk_register_region
);
484 void blk_unregister_region(dev_t devt
, unsigned long range
)
486 kobj_unmap(bdev_map
, devt
, range
);
489 EXPORT_SYMBOL(blk_unregister_region
);
491 static struct kobject
*exact_match(dev_t devt
, int *partno
, void *data
)
493 struct gendisk
*p
= data
;
495 return &disk_to_dev(p
)->kobj
;
498 static int exact_lock(dev_t devt
, void *data
)
500 struct gendisk
*p
= data
;
507 void add_disk(struct gendisk
*disk
)
509 struct backing_dev_info
*bdi
;
513 /* minors == 0 indicates to use ext devt from part0 and should
514 * be accompanied with EXT_DEVT flag. Make sure all
515 * parameters make sense.
517 WARN_ON(disk
->minors
&& !(disk
->major
|| disk
->first_minor
));
518 WARN_ON(!disk
->minors
&& !(disk
->flags
& GENHD_FL_EXT_DEVT
));
520 disk
->flags
|= GENHD_FL_UP
;
522 retval
= blk_alloc_devt(&disk
->part0
, &devt
);
527 disk_to_dev(disk
)->devt
= devt
;
529 /* ->major and ->first_minor aren't supposed to be
530 * dereferenced from here on, but set them just in case.
532 disk
->major
= MAJOR(devt
);
533 disk
->first_minor
= MINOR(devt
);
535 /* Register BDI before referencing it from bdev */
536 bdi
= &disk
->queue
->backing_dev_info
;
537 bdi_register_dev(bdi
, disk_devt(disk
));
539 blk_register_region(disk_devt(disk
), disk
->minors
, NULL
,
540 exact_match
, exact_lock
, disk
);
542 blk_register_queue(disk
);
544 retval
= sysfs_create_link(&disk_to_dev(disk
)->kobj
, &bdi
->dev
->kobj
,
549 EXPORT_SYMBOL(add_disk
);
550 EXPORT_SYMBOL(del_gendisk
); /* in partitions/check.c */
552 void unlink_gendisk(struct gendisk
*disk
)
554 sysfs_remove_link(&disk_to_dev(disk
)->kobj
, "bdi");
555 bdi_unregister(&disk
->queue
->backing_dev_info
);
556 blk_unregister_queue(disk
);
557 blk_unregister_region(disk_devt(disk
), disk
->minors
);
561 * get_gendisk - get partitioning information for a given device
562 * @devt: device to get partitioning information for
563 * @partno: returned partition index
565 * This function gets the structure containing partitioning
566 * information for the given device @devt.
568 struct gendisk
*get_gendisk(dev_t devt
, int *partno
)
570 struct gendisk
*disk
= NULL
;
572 if (MAJOR(devt
) != BLOCK_EXT_MAJOR
) {
573 struct kobject
*kobj
;
575 kobj
= kobj_lookup(bdev_map
, devt
, partno
);
577 disk
= dev_to_disk(kobj_to_dev(kobj
));
579 struct hd_struct
*part
;
581 mutex_lock(&ext_devt_mutex
);
582 part
= idr_find(&ext_devt_idr
, blk_mangle_minor(MINOR(devt
)));
583 if (part
&& get_disk(part_to_disk(part
))) {
584 *partno
= part
->partno
;
585 disk
= part_to_disk(part
);
587 mutex_unlock(&ext_devt_mutex
);
592 EXPORT_SYMBOL(get_gendisk
);
595 * bdget_disk - do bdget() by gendisk and partition number
596 * @disk: gendisk of interest
597 * @partno: partition number
599 * Find partition @partno from @disk, do bdget() on it.
605 * Resulting block_device on success, NULL on failure.
607 struct block_device
*bdget_disk(struct gendisk
*disk
, int partno
)
609 struct hd_struct
*part
;
610 struct block_device
*bdev
= NULL
;
612 part
= disk_get_part(disk
, partno
);
614 bdev
= bdget(part_devt(part
));
619 EXPORT_SYMBOL(bdget_disk
);
622 * print a full list of all partitions - intended for places where the root
623 * filesystem can't be mounted and thus to give the victim some idea of what
626 void __init
printk_all_partitions(void)
628 struct class_dev_iter iter
;
631 class_dev_iter_init(&iter
, &block_class
, NULL
, &disk_type
);
632 while ((dev
= class_dev_iter_next(&iter
))) {
633 struct gendisk
*disk
= dev_to_disk(dev
);
634 struct disk_part_iter piter
;
635 struct hd_struct
*part
;
636 char name_buf
[BDEVNAME_SIZE
];
637 char devt_buf
[BDEVT_SIZE
];
640 * Don't show empty devices or things that have been
643 if (get_capacity(disk
) == 0 ||
644 (disk
->flags
& GENHD_FL_SUPPRESS_PARTITION_INFO
))
648 * Note, unlike /proc/partitions, I am showing the
649 * numbers in hex - the same format as the root=
652 disk_part_iter_init(&piter
, disk
, DISK_PITER_INCL_PART0
);
653 while ((part
= disk_part_iter_next(&piter
))) {
654 bool is_part0
= part
== &disk
->part0
;
656 printk("%s%s %10llu %s", is_part0
? "" : " ",
657 bdevt_str(part_devt(part
), devt_buf
),
658 (unsigned long long)part
->nr_sects
>> 1,
659 disk_name(disk
, part
->partno
, name_buf
));
661 if (disk
->driverfs_dev
!= NULL
&&
662 disk
->driverfs_dev
->driver
!= NULL
)
663 printk(" driver: %s\n",
664 disk
->driverfs_dev
->driver
->name
);
666 printk(" (driver?)\n");
670 disk_part_iter_exit(&piter
);
672 class_dev_iter_exit(&iter
);
675 #ifdef CONFIG_PROC_FS
677 static void *disk_seqf_start(struct seq_file
*seqf
, loff_t
*pos
)
680 struct class_dev_iter
*iter
;
683 iter
= kmalloc(sizeof(*iter
), GFP_KERNEL
);
685 return ERR_PTR(-ENOMEM
);
687 seqf
->private = iter
;
688 class_dev_iter_init(iter
, &block_class
, NULL
, &disk_type
);
690 dev
= class_dev_iter_next(iter
);
695 return dev_to_disk(dev
);
698 static void *disk_seqf_next(struct seq_file
*seqf
, void *v
, loff_t
*pos
)
703 dev
= class_dev_iter_next(seqf
->private);
705 return dev_to_disk(dev
);
710 static void disk_seqf_stop(struct seq_file
*seqf
, void *v
)
712 struct class_dev_iter
*iter
= seqf
->private;
714 /* stop is called even after start failed :-( */
716 class_dev_iter_exit(iter
);
721 static void *show_partition_start(struct seq_file
*seqf
, loff_t
*pos
)
725 p
= disk_seqf_start(seqf
, pos
);
726 if (!IS_ERR(p
) && p
&& !*pos
)
727 seq_puts(seqf
, "major minor #blocks name\n\n");
731 static int show_partition(struct seq_file
*seqf
, void *v
)
733 struct gendisk
*sgp
= v
;
734 struct disk_part_iter piter
;
735 struct hd_struct
*part
;
736 char buf
[BDEVNAME_SIZE
];
738 /* Don't show non-partitionable removeable devices or empty devices */
739 if (!get_capacity(sgp
) || (!disk_partitionable(sgp
) &&
740 (sgp
->flags
& GENHD_FL_REMOVABLE
)))
742 if (sgp
->flags
& GENHD_FL_SUPPRESS_PARTITION_INFO
)
745 /* show the full disk and all non-0 size partitions of it */
746 disk_part_iter_init(&piter
, sgp
, DISK_PITER_INCL_PART0
);
747 while ((part
= disk_part_iter_next(&piter
)))
748 seq_printf(seqf
, "%4d %7d %10llu %s\n",
749 MAJOR(part_devt(part
)), MINOR(part_devt(part
)),
750 (unsigned long long)part
->nr_sects
>> 1,
751 disk_name(sgp
, part
->partno
, buf
));
752 disk_part_iter_exit(&piter
);
757 static const struct seq_operations partitions_op
= {
758 .start
= show_partition_start
,
759 .next
= disk_seqf_next
,
760 .stop
= disk_seqf_stop
,
761 .show
= show_partition
764 static int partitions_open(struct inode
*inode
, struct file
*file
)
766 return seq_open(file
, &partitions_op
);
769 static const struct file_operations proc_partitions_operations
= {
770 .open
= partitions_open
,
773 .release
= seq_release
,
778 static struct kobject
*base_probe(dev_t devt
, int *partno
, void *data
)
780 if (request_module("block-major-%d-%d", MAJOR(devt
), MINOR(devt
)) > 0)
781 /* Make old-style 2.4 aliases work */
782 request_module("block-major-%d", MAJOR(devt
));
786 static int __init
genhd_device_init(void)
790 block_class
.dev_kobj
= sysfs_dev_block_kobj
;
791 error
= class_register(&block_class
);
794 bdev_map
= kobj_map_init(base_probe
, &block_class_lock
);
797 register_blkdev(BLOCK_EXT_MAJOR
, "blkext");
799 #ifndef CONFIG_SYSFS_DEPRECATED
800 /* create top-level block dir */
801 block_depr
= kobject_create_and_add("block", NULL
);
806 subsys_initcall(genhd_device_init
);
808 static ssize_t
disk_range_show(struct device
*dev
,
809 struct device_attribute
*attr
, char *buf
)
811 struct gendisk
*disk
= dev_to_disk(dev
);
813 return sprintf(buf
, "%d\n", disk
->minors
);
816 static ssize_t
disk_ext_range_show(struct device
*dev
,
817 struct device_attribute
*attr
, char *buf
)
819 struct gendisk
*disk
= dev_to_disk(dev
);
821 return sprintf(buf
, "%d\n", disk_max_parts(disk
));
824 static ssize_t
disk_removable_show(struct device
*dev
,
825 struct device_attribute
*attr
, char *buf
)
827 struct gendisk
*disk
= dev_to_disk(dev
);
829 return sprintf(buf
, "%d\n",
830 (disk
->flags
& GENHD_FL_REMOVABLE
? 1 : 0));
833 static ssize_t
disk_ro_show(struct device
*dev
,
834 struct device_attribute
*attr
, char *buf
)
836 struct gendisk
*disk
= dev_to_disk(dev
);
838 return sprintf(buf
, "%d\n", get_disk_ro(disk
) ? 1 : 0);
841 static ssize_t
disk_capability_show(struct device
*dev
,
842 struct device_attribute
*attr
, char *buf
)
844 struct gendisk
*disk
= dev_to_disk(dev
);
846 return sprintf(buf
, "%x\n", disk
->flags
);
849 static ssize_t
disk_alignment_offset_show(struct device
*dev
,
850 struct device_attribute
*attr
,
853 struct gendisk
*disk
= dev_to_disk(dev
);
855 return sprintf(buf
, "%d\n", queue_alignment_offset(disk
->queue
));
858 static ssize_t
disk_discard_alignment_show(struct device
*dev
,
859 struct device_attribute
*attr
,
862 struct gendisk
*disk
= dev_to_disk(dev
);
864 return sprintf(buf
, "%d\n", queue_discard_alignment(disk
->queue
));
867 static DEVICE_ATTR(range
, S_IRUGO
, disk_range_show
, NULL
);
868 static DEVICE_ATTR(ext_range
, S_IRUGO
, disk_ext_range_show
, NULL
);
869 static DEVICE_ATTR(removable
, S_IRUGO
, disk_removable_show
, NULL
);
870 static DEVICE_ATTR(ro
, S_IRUGO
, disk_ro_show
, NULL
);
871 static DEVICE_ATTR(size
, S_IRUGO
, part_size_show
, NULL
);
872 static DEVICE_ATTR(alignment_offset
, S_IRUGO
, disk_alignment_offset_show
, NULL
);
873 static DEVICE_ATTR(discard_alignment
, S_IRUGO
, disk_discard_alignment_show
,
875 static DEVICE_ATTR(capability
, S_IRUGO
, disk_capability_show
, NULL
);
876 static DEVICE_ATTR(stat
, S_IRUGO
, part_stat_show
, NULL
);
877 static DEVICE_ATTR(inflight
, S_IRUGO
, part_inflight_show
, NULL
);
878 #ifdef CONFIG_FAIL_MAKE_REQUEST
879 static struct device_attribute dev_attr_fail
=
880 __ATTR(make
-it
-fail
, S_IRUGO
|S_IWUSR
, part_fail_show
, part_fail_store
);
882 #ifdef CONFIG_FAIL_IO_TIMEOUT
883 static struct device_attribute dev_attr_fail_timeout
=
884 __ATTR(io
-timeout
-fail
, S_IRUGO
|S_IWUSR
, part_timeout_show
,
888 static struct attribute
*disk_attrs
[] = {
889 &dev_attr_range
.attr
,
890 &dev_attr_ext_range
.attr
,
891 &dev_attr_removable
.attr
,
894 &dev_attr_alignment_offset
.attr
,
895 &dev_attr_discard_alignment
.attr
,
896 &dev_attr_capability
.attr
,
898 &dev_attr_inflight
.attr
,
899 #ifdef CONFIG_FAIL_MAKE_REQUEST
902 #ifdef CONFIG_FAIL_IO_TIMEOUT
903 &dev_attr_fail_timeout
.attr
,
908 static struct attribute_group disk_attr_group
= {
912 static const struct attribute_group
*disk_attr_groups
[] = {
917 static void disk_free_ptbl_rcu_cb(struct rcu_head
*head
)
919 struct disk_part_tbl
*ptbl
=
920 container_of(head
, struct disk_part_tbl
, rcu_head
);
926 * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
927 * @disk: disk to replace part_tbl for
928 * @new_ptbl: new part_tbl to install
930 * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The
931 * original ptbl is freed using RCU callback.
934 * Matching bd_mutx locked.
936 static void disk_replace_part_tbl(struct gendisk
*disk
,
937 struct disk_part_tbl
*new_ptbl
)
939 struct disk_part_tbl
*old_ptbl
= disk
->part_tbl
;
941 rcu_assign_pointer(disk
->part_tbl
, new_ptbl
);
944 rcu_assign_pointer(old_ptbl
->last_lookup
, NULL
);
945 call_rcu(&old_ptbl
->rcu_head
, disk_free_ptbl_rcu_cb
);
950 * disk_expand_part_tbl - expand disk->part_tbl
951 * @disk: disk to expand part_tbl for
952 * @partno: expand such that this partno can fit in
954 * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl
955 * uses RCU to allow unlocked dereferencing for stats and other stuff.
958 * Matching bd_mutex locked, might sleep.
961 * 0 on success, -errno on failure.
963 int disk_expand_part_tbl(struct gendisk
*disk
, int partno
)
965 struct disk_part_tbl
*old_ptbl
= disk
->part_tbl
;
966 struct disk_part_tbl
*new_ptbl
;
967 int len
= old_ptbl
? old_ptbl
->len
: 0;
968 int target
= partno
+ 1;
972 /* disk_max_parts() is zero during initialization, ignore if so */
973 if (disk_max_parts(disk
) && target
> disk_max_parts(disk
))
979 size
= sizeof(*new_ptbl
) + target
* sizeof(new_ptbl
->part
[0]);
980 new_ptbl
= kzalloc_node(size
, GFP_KERNEL
, disk
->node_id
);
984 new_ptbl
->len
= target
;
986 for (i
= 0; i
< len
; i
++)
987 rcu_assign_pointer(new_ptbl
->part
[i
], old_ptbl
->part
[i
]);
989 disk_replace_part_tbl(disk
, new_ptbl
);
993 static void disk_release(struct device
*dev
)
995 struct gendisk
*disk
= dev_to_disk(dev
);
998 disk_replace_part_tbl(disk
, NULL
);
999 free_part_stats(&disk
->part0
);
1002 struct class block_class
= {
1006 static char *block_devnode(struct device
*dev
, mode_t
*mode
)
1008 struct gendisk
*disk
= dev_to_disk(dev
);
1011 return disk
->devnode(disk
, mode
);
1015 static struct device_type disk_type
= {
1017 .groups
= disk_attr_groups
,
1018 .release
= disk_release
,
1019 .devnode
= block_devnode
,
1022 #ifdef CONFIG_PROC_FS
1024 * aggregate disk stat collector. Uses the same stats that the sysfs
1025 * entries do, above, but makes them available through one seq_file.
1027 * The output looks suspiciously like /proc/partitions with a bunch of
1030 static int diskstats_show(struct seq_file
*seqf
, void *v
)
1032 struct gendisk
*gp
= v
;
1033 struct disk_part_iter piter
;
1034 struct hd_struct
*hd
;
1035 char buf
[BDEVNAME_SIZE
];
1039 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1040 seq_puts(seqf, "major minor name"
1041 " rio rmerge rsect ruse wio wmerge "
1042 "wsect wuse running use aveq"
1046 disk_part_iter_init(&piter
, gp
, DISK_PITER_INCL_EMPTY_PART0
);
1047 while ((hd
= disk_part_iter_next(&piter
))) {
1048 cpu
= part_stat_lock();
1049 part_round_stats(cpu
, hd
);
1051 seq_printf(seqf
, "%4d %7d %s %lu %lu %llu "
1052 "%u %lu %lu %llu %u %u %u %u\n",
1053 MAJOR(part_devt(hd
)), MINOR(part_devt(hd
)),
1054 disk_name(gp
, hd
->partno
, buf
),
1055 part_stat_read(hd
, ios
[0]),
1056 part_stat_read(hd
, merges
[0]),
1057 (unsigned long long)part_stat_read(hd
, sectors
[0]),
1058 jiffies_to_msecs(part_stat_read(hd
, ticks
[0])),
1059 part_stat_read(hd
, ios
[1]),
1060 part_stat_read(hd
, merges
[1]),
1061 (unsigned long long)part_stat_read(hd
, sectors
[1]),
1062 jiffies_to_msecs(part_stat_read(hd
, ticks
[1])),
1064 jiffies_to_msecs(part_stat_read(hd
, io_ticks
)),
1065 jiffies_to_msecs(part_stat_read(hd
, time_in_queue
))
1068 disk_part_iter_exit(&piter
);
1073 static const struct seq_operations diskstats_op
= {
1074 .start
= disk_seqf_start
,
1075 .next
= disk_seqf_next
,
1076 .stop
= disk_seqf_stop
,
1077 .show
= diskstats_show
1080 static int diskstats_open(struct inode
*inode
, struct file
*file
)
1082 return seq_open(file
, &diskstats_op
);
1085 static const struct file_operations proc_diskstats_operations
= {
1086 .open
= diskstats_open
,
1088 .llseek
= seq_lseek
,
1089 .release
= seq_release
,
1092 static int __init
proc_genhd_init(void)
1094 proc_create("diskstats", 0, NULL
, &proc_diskstats_operations
);
1095 proc_create("partitions", 0, NULL
, &proc_partitions_operations
);
1098 module_init(proc_genhd_init
);
1099 #endif /* CONFIG_PROC_FS */
1101 static void media_change_notify_thread(struct work_struct
*work
)
1103 struct gendisk
*gd
= container_of(work
, struct gendisk
, async_notify
);
1104 char event
[] = "MEDIA_CHANGE=1";
1105 char *envp
[] = { event
, NULL
};
1108 * set enviroment vars to indicate which event this is for
1109 * so that user space will know to go check the media status.
1111 kobject_uevent_env(&disk_to_dev(gd
)->kobj
, KOBJ_CHANGE
, envp
);
1112 put_device(gd
->driverfs_dev
);
1116 dev_t
blk_lookup_devt(const char *name
, int partno
)
1118 dev_t devt
= MKDEV(0, 0);
1119 struct class_dev_iter iter
;
1122 class_dev_iter_init(&iter
, &block_class
, NULL
, &disk_type
);
1123 while ((dev
= class_dev_iter_next(&iter
))) {
1124 struct gendisk
*disk
= dev_to_disk(dev
);
1125 struct hd_struct
*part
;
1127 if (strcmp(dev_name(dev
), name
))
1130 if (partno
< disk
->minors
) {
1131 /* We need to return the right devno, even
1132 * if the partition doesn't exist yet.
1134 devt
= MKDEV(MAJOR(dev
->devt
),
1135 MINOR(dev
->devt
) + partno
);
1138 part
= disk_get_part(disk
, partno
);
1140 devt
= part_devt(part
);
1141 disk_put_part(part
);
1144 disk_put_part(part
);
1146 class_dev_iter_exit(&iter
);
1149 EXPORT_SYMBOL(blk_lookup_devt
);
1151 struct gendisk
*alloc_disk(int minors
)
1153 return alloc_disk_node(minors
, -1);
1155 EXPORT_SYMBOL(alloc_disk
);
1157 struct gendisk
*alloc_disk_node(int minors
, int node_id
)
1159 struct gendisk
*disk
;
1161 disk
= kmalloc_node(sizeof(struct gendisk
),
1162 GFP_KERNEL
| __GFP_ZERO
, node_id
);
1164 if (!init_part_stats(&disk
->part0
)) {
1168 disk
->node_id
= node_id
;
1169 if (disk_expand_part_tbl(disk
, 0)) {
1170 free_part_stats(&disk
->part0
);
1174 disk
->part_tbl
->part
[0] = &disk
->part0
;
1176 disk
->minors
= minors
;
1177 rand_initialize_disk(disk
);
1178 disk_to_dev(disk
)->class = &block_class
;
1179 disk_to_dev(disk
)->type
= &disk_type
;
1180 device_initialize(disk_to_dev(disk
));
1181 INIT_WORK(&disk
->async_notify
,
1182 media_change_notify_thread
);
1186 EXPORT_SYMBOL(alloc_disk_node
);
1188 struct kobject
*get_disk(struct gendisk
*disk
)
1190 struct module
*owner
;
1191 struct kobject
*kobj
;
1195 owner
= disk
->fops
->owner
;
1196 if (owner
&& !try_module_get(owner
))
1198 kobj
= kobject_get(&disk_to_dev(disk
)->kobj
);
1207 EXPORT_SYMBOL(get_disk
);
1209 void put_disk(struct gendisk
*disk
)
1212 kobject_put(&disk_to_dev(disk
)->kobj
);
1215 EXPORT_SYMBOL(put_disk
);
1217 static void set_disk_ro_uevent(struct gendisk
*gd
, int ro
)
1219 char event
[] = "DISK_RO=1";
1220 char *envp
[] = { event
, NULL
};
1224 kobject_uevent_env(&disk_to_dev(gd
)->kobj
, KOBJ_CHANGE
, envp
);
1227 void set_device_ro(struct block_device
*bdev
, int flag
)
1229 bdev
->bd_part
->policy
= flag
;
1232 EXPORT_SYMBOL(set_device_ro
);
1234 void set_disk_ro(struct gendisk
*disk
, int flag
)
1236 struct disk_part_iter piter
;
1237 struct hd_struct
*part
;
1239 if (disk
->part0
.policy
!= flag
) {
1240 set_disk_ro_uevent(disk
, flag
);
1241 disk
->part0
.policy
= flag
;
1244 disk_part_iter_init(&piter
, disk
, DISK_PITER_INCL_EMPTY
);
1245 while ((part
= disk_part_iter_next(&piter
)))
1246 part
->policy
= flag
;
1247 disk_part_iter_exit(&piter
);
1250 EXPORT_SYMBOL(set_disk_ro
);
1252 int bdev_read_only(struct block_device
*bdev
)
1256 return bdev
->bd_part
->policy
;
1259 EXPORT_SYMBOL(bdev_read_only
);
1261 int invalidate_partition(struct gendisk
*disk
, int partno
)
1264 struct block_device
*bdev
= bdget_disk(disk
, partno
);
1267 res
= __invalidate_device(bdev
);
1273 EXPORT_SYMBOL(invalidate_partition
);