4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
8 #include <linux/init.h>
10 #include <linux/fcntl.h>
11 #include <linux/slab.h>
12 #include <linux/kmod.h>
13 #include <linux/major.h>
14 #include <linux/smp_lock.h>
15 #include <linux/highmem.h>
16 #include <linux/blkdev.h>
17 #include <linux/module.h>
18 #include <linux/blkpg.h>
19 #include <linux/buffer_head.h>
20 #include <linux/writeback.h>
21 #include <linux/mpage.h>
22 #include <linux/mount.h>
23 #include <linux/uio.h>
24 #include <linux/namei.h>
25 #include <asm/uaccess.h>
29 struct block_device bdev
;
30 struct inode vfs_inode
;
33 static inline struct bdev_inode
*BDEV_I(struct inode
*inode
)
35 return container_of(inode
, struct bdev_inode
, vfs_inode
);
38 inline struct block_device
*I_BDEV(struct inode
*inode
)
40 return &BDEV_I(inode
)->bdev
;
43 EXPORT_SYMBOL(I_BDEV
);
45 static sector_t
max_block(struct block_device
*bdev
)
47 sector_t retval
= ~((sector_t
)0);
48 loff_t sz
= i_size_read(bdev
->bd_inode
);
51 unsigned int size
= block_size(bdev
);
52 unsigned int sizebits
= blksize_bits(size
);
53 retval
= (sz
>> sizebits
);
58 /* Kill _all_ buffers, dirty or not.. */
59 static void kill_bdev(struct block_device
*bdev
)
61 invalidate_bdev(bdev
, 1);
62 truncate_inode_pages(bdev
->bd_inode
->i_mapping
, 0);
65 int set_blocksize(struct block_device
*bdev
, int size
)
67 /* Size must be a power of two, and between 512 and PAGE_SIZE */
68 if (size
> PAGE_SIZE
|| size
< 512 || (size
& (size
-1)))
71 /* Size cannot be smaller than the size supported by the device */
72 if (size
< bdev_hardsect_size(bdev
))
75 /* Don't change the size if it is same as current */
76 if (bdev
->bd_block_size
!= size
) {
78 bdev
->bd_block_size
= size
;
79 bdev
->bd_inode
->i_blkbits
= blksize_bits(size
);
85 EXPORT_SYMBOL(set_blocksize
);
87 int sb_set_blocksize(struct super_block
*sb
, int size
)
89 if (set_blocksize(sb
->s_bdev
, size
))
91 /* If we get here, we know size is power of two
92 * and it's value is between 512 and PAGE_SIZE */
93 sb
->s_blocksize
= size
;
94 sb
->s_blocksize_bits
= blksize_bits(size
);
95 return sb
->s_blocksize
;
98 EXPORT_SYMBOL(sb_set_blocksize
);
100 int sb_min_blocksize(struct super_block
*sb
, int size
)
102 int minsize
= bdev_hardsect_size(sb
->s_bdev
);
105 return sb_set_blocksize(sb
, size
);
108 EXPORT_SYMBOL(sb_min_blocksize
);
111 blkdev_get_block(struct inode
*inode
, sector_t iblock
,
112 struct buffer_head
*bh
, int create
)
114 if (iblock
>= max_block(I_BDEV(inode
))) {
119 * for reads, we're just trying to fill a partial page.
120 * return a hole, they will have to call get_block again
121 * before they can fill it, and they will get -EIO at that
126 bh
->b_bdev
= I_BDEV(inode
);
127 bh
->b_blocknr
= iblock
;
128 set_buffer_mapped(bh
);
132 #ifdef CONFIG_DIRECTIO
134 blkdev_get_blocks(struct inode
*inode
, sector_t iblock
,
135 struct buffer_head
*bh
, int create
)
137 sector_t end_block
= max_block(I_BDEV(inode
));
138 unsigned long max_blocks
= bh
->b_size
>> inode
->i_blkbits
;
140 if ((iblock
+ max_blocks
) > end_block
) {
141 max_blocks
= end_block
- iblock
;
142 if ((long)max_blocks
<= 0) {
144 return -EIO
; /* write fully beyond EOF */
146 * It is a read which is fully beyond EOF. We return
147 * a !buffer_mapped buffer
153 bh
->b_bdev
= I_BDEV(inode
);
154 bh
->b_blocknr
= iblock
;
155 bh
->b_size
= max_blocks
<< inode
->i_blkbits
;
157 set_buffer_mapped(bh
);
162 blkdev_direct_IO(int rw
, struct kiocb
*iocb
, const struct iovec
*iov
,
163 loff_t offset
, unsigned long nr_segs
)
165 struct file
*file
= iocb
->ki_filp
;
166 struct inode
*inode
= file
->f_mapping
->host
;
168 return blockdev_direct_IO_no_locking(rw
, iocb
, inode
, I_BDEV(inode
),
169 iov
, offset
, nr_segs
, blkdev_get_blocks
, NULL
);
173 static int blkdev_writepage(struct page
*page
, struct writeback_control
*wbc
)
175 return block_write_full_page(page
, blkdev_get_block
, wbc
);
178 static int blkdev_readpage(struct file
* file
, struct page
* page
)
180 return block_read_full_page(page
, blkdev_get_block
);
183 static int blkdev_prepare_write(struct file
*file
, struct page
*page
, unsigned from
, unsigned to
)
185 return block_prepare_write(page
, from
, to
, blkdev_get_block
);
188 static int blkdev_commit_write(struct file
*file
, struct page
*page
, unsigned from
, unsigned to
)
190 return block_commit_write(page
, from
, to
);
195 * for a block special file file->f_dentry->d_inode->i_size is zero
196 * so we compute the size by hand (just as in block_read/write above)
198 static loff_t
block_llseek(struct file
*file
, loff_t offset
, int origin
)
200 struct inode
*bd_inode
= file
->f_mapping
->host
;
204 mutex_lock(&bd_inode
->i_mutex
);
205 size
= i_size_read(bd_inode
);
212 offset
+= file
->f_pos
;
215 if (offset
>= 0 && offset
<= size
) {
216 if (offset
!= file
->f_pos
) {
217 file
->f_pos
= offset
;
221 mutex_unlock(&bd_inode
->i_mutex
);
226 * Filp is never NULL; the only case when ->fsync() is called with
227 * NULL first argument is nfsd_sync_dir() and that's not a directory.
230 static int block_fsync(struct file
*filp
, struct dentry
*dentry
, int datasync
)
232 return sync_blockdev(I_BDEV(filp
->f_mapping
->host
));
239 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(bdev_lock
);
240 static kmem_cache_t
* bdev_cachep __read_mostly
;
242 static struct inode
*bdev_alloc_inode(struct super_block
*sb
)
244 struct bdev_inode
*ei
= kmem_cache_alloc(bdev_cachep
, SLAB_KERNEL
);
247 return &ei
->vfs_inode
;
250 static void bdev_destroy_inode(struct inode
*inode
)
252 struct bdev_inode
*bdi
= BDEV_I(inode
);
254 bdi
->bdev
.bd_inode_backing_dev_info
= NULL
;
255 kmem_cache_free(bdev_cachep
, bdi
);
258 static void init_once(void * foo
, kmem_cache_t
* cachep
, unsigned long flags
)
260 struct bdev_inode
*ei
= (struct bdev_inode
*) foo
;
261 struct block_device
*bdev
= &ei
->bdev
;
263 if ((flags
& (SLAB_CTOR_VERIFY
|SLAB_CTOR_CONSTRUCTOR
)) ==
264 SLAB_CTOR_CONSTRUCTOR
)
266 memset(bdev
, 0, sizeof(*bdev
));
267 mutex_init(&bdev
->bd_mutex
);
268 mutex_init(&bdev
->bd_mount_mutex
);
269 INIT_LIST_HEAD(&bdev
->bd_inodes
);
270 INIT_LIST_HEAD(&bdev
->bd_list
);
272 INIT_LIST_HEAD(&bdev
->bd_holder_list
);
274 inode_init_once(&ei
->vfs_inode
);
278 static inline void __bd_forget(struct inode
*inode
)
280 list_del_init(&inode
->i_devices
);
281 #if 0 // mask by Victor Yu. 02-12-2007
282 inode
->i_bdev
= NULL
;
284 inode
->u
.i_bdev
= NULL
;
286 inode
->i_mapping
= &inode
->i_data
;
289 static void bdev_clear_inode(struct inode
*inode
)
291 struct block_device
*bdev
= &BDEV_I(inode
)->bdev
;
293 spin_lock(&bdev_lock
);
294 while ( (p
= bdev
->bd_inodes
.next
) != &bdev
->bd_inodes
) {
295 __bd_forget(list_entry(p
, struct inode
, i_devices
));
297 list_del_init(&bdev
->bd_list
);
298 spin_unlock(&bdev_lock
);
301 static struct super_operations bdev_sops
= {
302 .statfs
= simple_statfs
,
303 .alloc_inode
= bdev_alloc_inode
,
304 .destroy_inode
= bdev_destroy_inode
,
305 .drop_inode
= generic_delete_inode
,
306 .clear_inode
= bdev_clear_inode
,
309 static int bd_get_sb(struct file_system_type
*fs_type
,
310 int flags
, const char *dev_name
, void *data
, struct vfsmount
*mnt
)
312 return get_sb_pseudo(fs_type
, "bdev:", &bdev_sops
, 0x62646576, mnt
);
315 static struct file_system_type bd_type
= {
318 .kill_sb
= kill_anon_super
,
321 static struct vfsmount
*bd_mnt __read_mostly
;
322 struct super_block
*blockdev_superblock
;
324 void __init
bdev_cache_init(void)
327 bdev_cachep
= kmem_cache_create("bdev_cache", sizeof(struct bdev_inode
),
328 0, (SLAB_HWCACHE_ALIGN
|SLAB_RECLAIM_ACCOUNT
|
329 SLAB_MEM_SPREAD
|SLAB_PANIC
),
331 err
= register_filesystem(&bd_type
);
333 panic("Cannot register bdev pseudo-fs");
334 bd_mnt
= kern_mount(&bd_type
);
335 err
= PTR_ERR(bd_mnt
);
337 panic("Cannot create bdev pseudo-fs");
338 blockdev_superblock
= bd_mnt
->mnt_sb
; /* For writeback */
342 * Most likely _very_ bad one - but then it's hardly critical for small
343 * /dev and can be fixed when somebody will need really large one.
344 * Keep in mind that it will be fed through icache hash function too.
346 static inline unsigned long hash(dev_t dev
)
348 return MAJOR(dev
)+MINOR(dev
);
351 static int bdev_test(struct inode
*inode
, void *data
)
353 return BDEV_I(inode
)->bdev
.bd_dev
== *(dev_t
*)data
;
356 static int bdev_set(struct inode
*inode
, void *data
)
358 BDEV_I(inode
)->bdev
.bd_dev
= *(dev_t
*)data
;
362 static LIST_HEAD(all_bdevs
);
364 struct block_device
*bdget(dev_t dev
)
366 struct block_device
*bdev
;
369 inode
= iget5_locked(bd_mnt
->mnt_sb
, hash(dev
),
370 bdev_test
, bdev_set
, &dev
);
375 bdev
= &BDEV_I(inode
)->bdev
;
377 if (inode
->i_state
& I_NEW
) {
378 bdev
->bd_contains
= NULL
;
379 bdev
->bd_inode
= inode
;
380 bdev
->bd_block_size
= (1 << inode
->i_blkbits
);
381 bdev
->bd_part_count
= 0;
382 bdev
->bd_invalidated
= 0;
383 inode
->i_mode
= S_IFBLK
;
385 #if 0 // mask by Victor Yu. 02-12-2007
386 inode
->i_bdev
= bdev
;
388 inode
->u
.i_bdev
= bdev
;
390 inode
->i_data
.a_ops
= &def_blk_aops
;
391 mapping_set_gfp_mask(&inode
->i_data
, GFP_USER
);
392 inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
393 spin_lock(&bdev_lock
);
394 list_add(&bdev
->bd_list
, &all_bdevs
);
395 spin_unlock(&bdev_lock
);
396 unlock_new_inode(inode
);
401 EXPORT_SYMBOL(bdget
);
403 long nr_blockdev_pages(void)
407 spin_lock(&bdev_lock
);
408 list_for_each(p
, &all_bdevs
) {
409 struct block_device
*bdev
;
410 bdev
= list_entry(p
, struct block_device
, bd_list
);
411 ret
+= bdev
->bd_inode
->i_mapping
->nrpages
;
413 spin_unlock(&bdev_lock
);
417 void bdput(struct block_device
*bdev
)
419 iput(bdev
->bd_inode
);
422 EXPORT_SYMBOL(bdput
);
424 static struct block_device
*bd_acquire(struct inode
*inode
)
426 struct block_device
*bdev
;
428 spin_lock(&bdev_lock
);
429 #if 0 // mask by Victor Yu. 02-12-2007
430 bdev
= inode
->i_bdev
;
432 bdev
= inode
->u
.i_bdev
;
435 atomic_inc(&bdev
->bd_inode
->i_count
);
436 spin_unlock(&bdev_lock
);
439 spin_unlock(&bdev_lock
);
441 bdev
= bdget(inode
->i_rdev
);
443 spin_lock(&bdev_lock
);
444 #if 0 // mask by Victor Yu. 02-12-2007
445 if (!inode
->i_bdev
) {
447 if (!inode
->u
.i_bdev
) {
450 * We take an additional bd_inode->i_count for inode,
451 * and it's released in clear_inode() of inode.
452 * So, we can access it via ->i_mapping always
455 atomic_inc(&bdev
->bd_inode
->i_count
);
456 #if 0 // mask by Viccctor Yu. 02-12-2007
457 inode
->i_bdev
= bdev
;
459 inode
->u
.i_bdev
= bdev
;
461 inode
->i_mapping
= bdev
->bd_inode
->i_mapping
;
462 list_add(&inode
->i_devices
, &bdev
->bd_inodes
);
464 spin_unlock(&bdev_lock
);
469 /* Call when you free inode */
471 void bd_forget(struct inode
*inode
)
473 struct block_device
*bdev
= NULL
;
475 spin_lock(&bdev_lock
);
476 #if 0 // mask by Victor Yu. 02-12-2007
479 if (inode
->u
.i_bdev
) {
481 if (inode
->i_sb
!= blockdev_superblock
)
482 #if 0 // mask by Victor Yu. 02-12-2007
483 bdev
= inode
->i_bdev
;
485 bdev
= inode
->u
.i_bdev
;
489 spin_unlock(&bdev_lock
);
492 iput(bdev
->bd_inode
);
495 int bd_claim(struct block_device
*bdev
, void *holder
)
498 spin_lock(&bdev_lock
);
500 /* first decide result */
501 if (bdev
->bd_holder
== holder
)
502 res
= 0; /* already a holder */
503 else if (bdev
->bd_holder
!= NULL
)
504 res
= -EBUSY
; /* held by someone else */
505 else if (bdev
->bd_contains
== bdev
)
506 res
= 0; /* is a whole device which isn't held */
508 else if (bdev
->bd_contains
->bd_holder
== bd_claim
)
509 res
= 0; /* is a partition of a device that is being partitioned */
510 else if (bdev
->bd_contains
->bd_holder
!= NULL
)
511 res
= -EBUSY
; /* is a partition of a held device */
513 res
= 0; /* is a partition of an un-held device */
515 /* now impose change */
517 /* note that for a whole device bd_holders
518 * will be incremented twice, and bd_holder will
519 * be set to bd_claim before being set to holder
521 bdev
->bd_contains
->bd_holders
++;
522 bdev
->bd_contains
->bd_holder
= bd_claim
;
524 bdev
->bd_holder
= holder
;
526 spin_unlock(&bdev_lock
);
530 EXPORT_SYMBOL(bd_claim
);
532 void bd_release(struct block_device
*bdev
)
534 spin_lock(&bdev_lock
);
535 if (!--bdev
->bd_contains
->bd_holders
)
536 bdev
->bd_contains
->bd_holder
= NULL
;
537 if (!--bdev
->bd_holders
)
538 bdev
->bd_holder
= NULL
;
539 spin_unlock(&bdev_lock
);
542 EXPORT_SYMBOL(bd_release
);
546 * Functions for bd_claim_by_kobject / bd_release_from_kobject
548 * If a kobject is passed to bd_claim_by_kobject()
549 * and the kobject has a parent directory,
550 * following symlinks are created:
551 * o from the kobject to the claimed bdev
552 * o from "holders" directory of the bdev to the parent of the kobject
553 * bd_release_from_kobject() removes these symlinks.
556 * If /dev/dm-0 maps to /dev/sda, kobject corresponding to
557 * /sys/block/dm-0/slaves is passed to bd_claim_by_kobject(), then:
558 * /sys/block/dm-0/slaves/sda --> /sys/block/sda
559 * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
562 static struct kobject
*bdev_get_kobj(struct block_device
*bdev
)
564 if (bdev
->bd_contains
!= bdev
)
565 return kobject_get(&bdev
->bd_part
->kobj
);
567 return kobject_get(&bdev
->bd_disk
->kobj
);
570 static struct kobject
*bdev_get_holder(struct block_device
*bdev
)
572 if (bdev
->bd_contains
!= bdev
)
573 return kobject_get(bdev
->bd_part
->holder_dir
);
575 return kobject_get(bdev
->bd_disk
->holder_dir
);
578 static int add_symlink(struct kobject
*from
, struct kobject
*to
)
582 return sysfs_create_link(from
, to
, kobject_name(to
));
585 static void del_symlink(struct kobject
*from
, struct kobject
*to
)
589 sysfs_remove_link(from
, kobject_name(to
));
593 * 'struct bd_holder' contains pointers to kobjects symlinked by
594 * bd_claim_by_kobject.
595 * It's connected to bd_holder_list which is protected by bdev->bd_sem.
598 struct list_head list
; /* chain of holders of the bdev */
599 int count
; /* references from the holder */
600 struct kobject
*sdir
; /* holder object, e.g. "/block/dm-0/slaves" */
601 struct kobject
*hdev
; /* e.g. "/block/dm-0" */
602 struct kobject
*hdir
; /* e.g. "/block/sda/holders" */
603 struct kobject
*sdev
; /* e.g. "/block/sda" */
607 * Get references of related kobjects at once.
608 * Returns 1 on success. 0 on failure.
610 * Should call bd_holder_release_dirs() after successful use.
612 static int bd_holder_grab_dirs(struct block_device
*bdev
,
613 struct bd_holder
*bo
)
618 bo
->sdir
= kobject_get(bo
->sdir
);
622 bo
->hdev
= kobject_get(bo
->sdir
->parent
);
626 bo
->sdev
= bdev_get_kobj(bdev
);
630 bo
->hdir
= bdev_get_holder(bdev
);
637 kobject_put(bo
->sdev
);
639 kobject_put(bo
->hdev
);
641 kobject_put(bo
->sdir
);
646 /* Put references of related kobjects at once. */
647 static void bd_holder_release_dirs(struct bd_holder
*bo
)
649 kobject_put(bo
->hdir
);
650 kobject_put(bo
->sdev
);
651 kobject_put(bo
->hdev
);
652 kobject_put(bo
->sdir
);
655 static struct bd_holder
*alloc_bd_holder(struct kobject
*kobj
)
657 struct bd_holder
*bo
;
659 bo
= kzalloc(sizeof(*bo
), GFP_KERNEL
);
669 static void free_bd_holder(struct bd_holder
*bo
)
675 * find_bd_holder - find matching struct bd_holder from the block device
677 * @bdev: struct block device to be searched
678 * @bo: target struct bd_holder
680 * Returns matching entry with @bo in @bdev->bd_holder_list.
681 * If found, increment the reference count and return the pointer.
682 * If not found, returns NULL.
684 static struct bd_holder
*find_bd_holder(struct block_device
*bdev
,
685 struct bd_holder
*bo
)
687 struct bd_holder
*tmp
;
689 list_for_each_entry(tmp
, &bdev
->bd_holder_list
, list
)
690 if (tmp
->sdir
== bo
->sdir
) {
699 * add_bd_holder - create sysfs symlinks for bd_claim() relationship
701 * @bdev: block device to be bd_claimed
702 * @bo: preallocated and initialized by alloc_bd_holder()
704 * Add @bo to @bdev->bd_holder_list, create symlinks.
706 * Returns 0 if symlinks are created.
707 * Returns -ve if something fails.
709 static int add_bd_holder(struct block_device
*bdev
, struct bd_holder
*bo
)
716 if (!bd_holder_grab_dirs(bdev
, bo
))
719 ret
= add_symlink(bo
->sdir
, bo
->sdev
);
721 ret
= add_symlink(bo
->hdir
, bo
->hdev
);
723 del_symlink(bo
->sdir
, bo
->sdev
);
726 list_add_tail(&bo
->list
, &bdev
->bd_holder_list
);
731 * del_bd_holder - delete sysfs symlinks for bd_claim() relationship
733 * @bdev: block device to be bd_claimed
734 * @kobj: holder's kobject
736 * If there is matching entry with @kobj in @bdev->bd_holder_list
737 * and no other bd_claim() from the same kobject,
738 * remove the struct bd_holder from the list, delete symlinks for it.
740 * Returns a pointer to the struct bd_holder when it's removed from the list
741 * and ready to be freed.
742 * Returns NULL if matching claim isn't found or there is other bd_claim()
743 * by the same kobject.
745 static struct bd_holder
*del_bd_holder(struct block_device
*bdev
,
746 struct kobject
*kobj
)
748 struct bd_holder
*bo
;
750 list_for_each_entry(bo
, &bdev
->bd_holder_list
, list
) {
751 if (bo
->sdir
== kobj
) {
753 BUG_ON(bo
->count
< 0);
756 del_symlink(bo
->sdir
, bo
->sdev
);
757 del_symlink(bo
->hdir
, bo
->hdev
);
758 bd_holder_release_dirs(bo
);
769 * bd_claim_by_kobject - bd_claim() with additional kobject signature
771 * @bdev: block device to be claimed
772 * @holder: holder's signature
773 * @kobj: holder's kobject
775 * Do bd_claim() and if it succeeds, create sysfs symlinks between
776 * the bdev and the holder's kobject.
777 * Use bd_release_from_kobject() when relesing the claimed bdev.
779 * Returns 0 on success. (same as bd_claim())
780 * Returns errno on failure.
782 static int bd_claim_by_kobject(struct block_device
*bdev
, void *holder
,
783 struct kobject
*kobj
)
786 struct bd_holder
*bo
, *found
;
791 bo
= alloc_bd_holder(kobj
);
795 mutex_lock_nested(&bdev
->bd_mutex
, BD_MUTEX_PARTITION
);
796 res
= bd_claim(bdev
, holder
);
798 found
= find_bd_holder(bdev
, bo
);
800 res
= add_bd_holder(bdev
, bo
);
808 mutex_unlock(&bdev
->bd_mutex
);
814 * bd_release_from_kobject - bd_release() with additional kobject signature
816 * @bdev: block device to be released
817 * @kobj: holder's kobject
819 * Do bd_release() and remove sysfs symlinks created by bd_claim_by_kobject().
821 static void bd_release_from_kobject(struct block_device
*bdev
,
822 struct kobject
*kobj
)
824 struct bd_holder
*bo
;
829 mutex_lock_nested(&bdev
->bd_mutex
, BD_MUTEX_PARTITION
);
831 if ((bo
= del_bd_holder(bdev
, kobj
)))
833 mutex_unlock(&bdev
->bd_mutex
);
837 * bd_claim_by_disk - wrapper function for bd_claim_by_kobject()
839 * @bdev: block device to be claimed
840 * @holder: holder's signature
841 * @disk: holder's gendisk
843 * Call bd_claim_by_kobject() with getting @disk->slave_dir.
845 int bd_claim_by_disk(struct block_device
*bdev
, void *holder
,
846 struct gendisk
*disk
)
848 return bd_claim_by_kobject(bdev
, holder
, kobject_get(disk
->slave_dir
));
850 EXPORT_SYMBOL_GPL(bd_claim_by_disk
);
853 * bd_release_from_disk - wrapper function for bd_release_from_kobject()
855 * @bdev: block device to be claimed
856 * @disk: holder's gendisk
858 * Call bd_release_from_kobject() and put @disk->slave_dir.
860 void bd_release_from_disk(struct block_device
*bdev
, struct gendisk
*disk
)
862 bd_release_from_kobject(bdev
, disk
->slave_dir
);
863 kobject_put(disk
->slave_dir
);
865 EXPORT_SYMBOL_GPL(bd_release_from_disk
);
869 * Tries to open block device by device number. Use it ONLY if you
870 * really do not have anything better - i.e. when you are behind a
871 * truly sucky interface and all you are given is a device number. _Never_
872 * to be used for internal purposes. If you ever need it - reconsider
875 struct block_device
*open_by_devnum(dev_t dev
, unsigned mode
)
877 struct block_device
*bdev
= bdget(dev
);
879 int flags
= mode
& FMODE_WRITE
? O_RDWR
: O_RDONLY
;
881 err
= blkdev_get(bdev
, mode
, flags
);
882 return err
? ERR_PTR(err
) : bdev
;
885 EXPORT_SYMBOL(open_by_devnum
);
888 blkdev_get_partition(struct block_device
*bdev
, mode_t mode
, unsigned flags
);
890 struct block_device
*open_partition_by_devnum(dev_t dev
, unsigned mode
)
892 struct block_device
*bdev
= bdget(dev
);
894 int flags
= mode
& FMODE_WRITE
? O_RDWR
: O_RDONLY
;
896 err
= blkdev_get_partition(bdev
, mode
, flags
);
897 return err
? ERR_PTR(err
) : bdev
;
900 EXPORT_SYMBOL(open_partition_by_devnum
);
904 * This routine checks whether a removable media has been changed,
905 * and invalidates all buffer-cache-entries in that case. This
906 * is a relatively slow routine, so we have to try to minimize using
907 * it. Thus it is called only upon a 'mount' or 'open'. This
908 * is the best way of combining speed and utility, I think.
909 * People changing diskettes in the middle of an operation deserve
912 int check_disk_change(struct block_device
*bdev
)
914 struct gendisk
*disk
= bdev
->bd_disk
;
915 struct block_device_operations
* bdops
= disk
->fops
;
917 if (!bdops
->media_changed
)
919 if (!bdops
->media_changed(bdev
->bd_disk
))
922 if (__invalidate_device(bdev
))
923 printk("VFS: busy inodes on changed media.\n");
925 if (bdops
->revalidate_disk
)
926 bdops
->revalidate_disk(bdev
->bd_disk
);
927 if (bdev
->bd_disk
->minors
> 1)
928 bdev
->bd_invalidated
= 1;
932 EXPORT_SYMBOL(check_disk_change
);
934 void bd_set_size(struct block_device
*bdev
, loff_t size
)
936 unsigned bsize
= bdev_hardsect_size(bdev
);
938 bdev
->bd_inode
->i_size
= size
;
939 while (bsize
< PAGE_CACHE_SIZE
) {
944 bdev
->bd_block_size
= bsize
;
945 bdev
->bd_inode
->i_blkbits
= blksize_bits(bsize
);
947 EXPORT_SYMBOL(bd_set_size
);
949 static int __blkdev_put(struct block_device
*bdev
, unsigned int subclass
)
952 struct inode
*bd_inode
= bdev
->bd_inode
;
953 struct gendisk
*disk
= bdev
->bd_disk
;
955 mutex_lock_nested(&bdev
->bd_mutex
, subclass
);
957 if (!--bdev
->bd_openers
) {
961 if (bdev
->bd_contains
== bdev
) {
962 if (disk
->fops
->release
)
963 ret
= disk
->fops
->release(bd_inode
, NULL
);
965 mutex_lock_nested(&bdev
->bd_contains
->bd_mutex
,
967 bdev
->bd_contains
->bd_part_count
--;
968 mutex_unlock(&bdev
->bd_contains
->bd_mutex
);
970 if (!bdev
->bd_openers
) {
971 struct module
*owner
= disk
->fops
->owner
;
976 if (bdev
->bd_contains
!= bdev
) {
977 kobject_put(&bdev
->bd_part
->kobj
);
978 bdev
->bd_part
= NULL
;
980 bdev
->bd_disk
= NULL
;
981 bdev
->bd_inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
982 if (bdev
!= bdev
->bd_contains
)
983 __blkdev_put(bdev
->bd_contains
, subclass
+ 1);
984 bdev
->bd_contains
= NULL
;
987 mutex_unlock(&bdev
->bd_mutex
);
992 int blkdev_put(struct block_device
*bdev
)
994 return __blkdev_put(bdev
, BD_MUTEX_NORMAL
);
996 EXPORT_SYMBOL(blkdev_put
);
998 int blkdev_put_partition(struct block_device
*bdev
)
1000 return __blkdev_put(bdev
, BD_MUTEX_PARTITION
);
1002 EXPORT_SYMBOL(blkdev_put_partition
);
1005 blkdev_get_whole(struct block_device
*bdev
, mode_t mode
, unsigned flags
);
1008 do_open(struct block_device
*bdev
, struct file
*file
, unsigned int subclass
)
1010 struct module
*owner
= NULL
;
1011 struct gendisk
*disk
;
1015 file
->f_mapping
= bdev
->bd_inode
->i_mapping
;
1017 disk
= get_gendisk(bdev
->bd_dev
, &part
);
1023 owner
= disk
->fops
->owner
;
1025 mutex_lock_nested(&bdev
->bd_mutex
, subclass
);
1027 if (!bdev
->bd_openers
) {
1028 bdev
->bd_disk
= disk
;
1029 bdev
->bd_contains
= bdev
;
1031 struct backing_dev_info
*bdi
;
1032 if (disk
->fops
->open
) {
1033 ret
= disk
->fops
->open(bdev
->bd_inode
, file
);
1037 if (!bdev
->bd_openers
) {
1038 bd_set_size(bdev
,(loff_t
)get_capacity(disk
)<<9);
1039 bdi
= blk_get_backing_dev_info(bdev
);
1041 bdi
= &default_backing_dev_info
;
1042 bdev
->bd_inode
->i_data
.backing_dev_info
= bdi
;
1044 if (bdev
->bd_invalidated
)
1045 rescan_partitions(disk
, bdev
);
1047 struct hd_struct
*p
;
1048 struct block_device
*whole
;
1049 whole
= bdget_disk(disk
, 0);
1053 ret
= blkdev_get_whole(whole
, file
->f_mode
, file
->f_flags
);
1056 bdev
->bd_contains
= whole
;
1057 mutex_lock_nested(&whole
->bd_mutex
, BD_MUTEX_WHOLE
);
1058 whole
->bd_part_count
++;
1059 p
= disk
->part
[part
- 1];
1060 bdev
->bd_inode
->i_data
.backing_dev_info
=
1061 whole
->bd_inode
->i_data
.backing_dev_info
;
1062 if (!(disk
->flags
& GENHD_FL_UP
) || !p
|| !p
->nr_sects
) {
1063 whole
->bd_part_count
--;
1064 mutex_unlock(&whole
->bd_mutex
);
1068 kobject_get(&p
->kobj
);
1070 bd_set_size(bdev
, (loff_t
) p
->nr_sects
<< 9);
1071 mutex_unlock(&whole
->bd_mutex
);
1076 if (bdev
->bd_contains
== bdev
) {
1077 if (bdev
->bd_disk
->fops
->open
) {
1078 ret
= bdev
->bd_disk
->fops
->open(bdev
->bd_inode
, file
);
1082 if (bdev
->bd_invalidated
)
1083 rescan_partitions(bdev
->bd_disk
, bdev
);
1085 mutex_lock_nested(&bdev
->bd_contains
->bd_mutex
,
1087 bdev
->bd_contains
->bd_part_count
++;
1088 mutex_unlock(&bdev
->bd_contains
->bd_mutex
);
1092 mutex_unlock(&bdev
->bd_mutex
);
1097 bdev
->bd_disk
= NULL
;
1098 bdev
->bd_inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
1099 if (bdev
!= bdev
->bd_contains
)
1100 __blkdev_put(bdev
->bd_contains
, BD_MUTEX_WHOLE
);
1101 bdev
->bd_contains
= NULL
;
1105 mutex_unlock(&bdev
->bd_mutex
);
1112 int blkdev_get(struct block_device
*bdev
, mode_t mode
, unsigned flags
)
1115 * This crockload is due to bad choice of ->open() type.
1117 * For now, block device ->open() routine must _not_
1118 * examine anything in 'inode' argument except ->i_rdev.
1120 struct file fake_file
= {};
1121 struct dentry fake_dentry
= {};
1122 fake_file
.f_mode
= mode
;
1123 fake_file
.f_flags
= flags
;
1124 fake_file
.f_dentry
= &fake_dentry
;
1125 fake_dentry
.d_inode
= bdev
->bd_inode
;
1127 return do_open(bdev
, &fake_file
, BD_MUTEX_NORMAL
);
1130 EXPORT_SYMBOL(blkdev_get
);
1133 blkdev_get_whole(struct block_device
*bdev
, mode_t mode
, unsigned flags
)
1136 * This crockload is due to bad choice of ->open() type.
1138 * For now, block device ->open() routine must _not_
1139 * examine anything in 'inode' argument except ->i_rdev.
1141 struct file fake_file
= {};
1142 struct dentry fake_dentry
= {};
1143 fake_file
.f_mode
= mode
;
1144 fake_file
.f_flags
= flags
;
1145 fake_file
.f_dentry
= &fake_dentry
;
1146 fake_dentry
.d_inode
= bdev
->bd_inode
;
1148 return do_open(bdev
, &fake_file
, BD_MUTEX_WHOLE
);
1152 blkdev_get_partition(struct block_device
*bdev
, mode_t mode
, unsigned flags
)
1155 * This crockload is due to bad choice of ->open() type.
1157 * For now, block device ->open() routine must _not_
1158 * examine anything in 'inode' argument except ->i_rdev.
1160 struct file fake_file
= {};
1161 struct dentry fake_dentry
= {};
1162 fake_file
.f_mode
= mode
;
1163 fake_file
.f_flags
= flags
;
1164 fake_file
.f_dentry
= &fake_dentry
;
1165 fake_dentry
.d_inode
= bdev
->bd_inode
;
1167 return do_open(bdev
, &fake_file
, BD_MUTEX_PARTITION
);
1170 static int blkdev_open(struct inode
* inode
, struct file
* filp
)
1172 struct block_device
*bdev
;
1176 * Preserve backwards compatibility and allow large file access
1177 * even if userspace doesn't ask for it explicitly. Some mkfs
1178 * binary needs it. We might want to drop this workaround
1179 * during an unstable branch.
1181 filp
->f_flags
|= O_LARGEFILE
;
1183 bdev
= bd_acquire(inode
);
1187 res
= do_open(bdev
, filp
, BD_MUTEX_NORMAL
);
1191 if (!(filp
->f_flags
& O_EXCL
) )
1194 if (!(res
= bd_claim(bdev
, filp
)))
1201 static int blkdev_close(struct inode
* inode
, struct file
* filp
)
1203 struct block_device
*bdev
= I_BDEV(filp
->f_mapping
->host
);
1204 if (bdev
->bd_holder
== filp
)
1206 return blkdev_put(bdev
);
1209 static long block_ioctl(struct file
*file
, unsigned cmd
, unsigned long arg
)
1211 return blkdev_ioctl(file
->f_mapping
->host
, file
, cmd
, arg
);
1214 const struct address_space_operations def_blk_aops
= {
1215 .readpage
= blkdev_readpage
,
1216 .writepage
= blkdev_writepage
,
1217 .sync_page
= block_sync_page
,
1218 .prepare_write
= blkdev_prepare_write
,
1219 .commit_write
= blkdev_commit_write
,
1220 .writepages
= generic_writepages
,
1221 #ifdef CONFIG_DIRECTIO
1222 .direct_IO
= blkdev_direct_IO
,
1226 const struct file_operations def_blk_fops
= {
1227 .open
= blkdev_open
,
1228 .release
= blkdev_close
,
1229 .llseek
= block_llseek
,
1230 .read
= do_sync_read
,
1231 .write
= do_sync_write
,
1232 .aio_read
= generic_file_aio_read
,
1233 .aio_write
= generic_file_aio_write_nolock
,
1234 .mmap
= generic_file_mmap
,
1235 .fsync
= block_fsync
,
1236 .unlocked_ioctl
= block_ioctl
,
1237 #ifdef CONFIG_COMPAT
1238 .compat_ioctl
= compat_blkdev_ioctl
,
1240 .sendfile
= generic_file_sendfile
,
1241 .splice_read
= generic_file_splice_read
,
1242 .splice_write
= generic_file_splice_write
,
1245 int ioctl_by_bdev(struct block_device
*bdev
, unsigned cmd
, unsigned long arg
)
1248 mm_segment_t old_fs
= get_fs();
1250 res
= blkdev_ioctl(bdev
->bd_inode
, NULL
, cmd
, arg
);
1255 EXPORT_SYMBOL(ioctl_by_bdev
);
1258 * lookup_bdev - lookup a struct block_device by name
1260 * @path: special file representing the block device
1262 * Get a reference to the blockdevice at @path in the current
1263 * namespace if possible and return it. Return ERR_PTR(error)
1266 struct block_device
*lookup_bdev(const char *path
)
1268 struct block_device
*bdev
;
1269 struct inode
*inode
;
1270 struct nameidata nd
;
1273 if (!path
|| !*path
)
1274 return ERR_PTR(-EINVAL
);
1276 error
= path_lookup(path
, LOOKUP_FOLLOW
, &nd
);
1278 return ERR_PTR(error
);
1280 inode
= nd
.dentry
->d_inode
;
1282 if (!S_ISBLK(inode
->i_mode
))
1285 if (nd
.mnt
->mnt_flags
& MNT_NODEV
)
1288 bdev
= bd_acquire(inode
);
1295 bdev
= ERR_PTR(error
);
1300 * open_bdev_excl - open a block device by name and set it up for use
1302 * @path: special file representing the block device
1303 * @flags: %MS_RDONLY for opening read-only
1304 * @holder: owner for exclusion
1306 * Open the blockdevice described by the special file at @path, claim it
1309 struct block_device
*open_bdev_excl(const char *path
, int flags
, void *holder
)
1311 struct block_device
*bdev
;
1312 mode_t mode
= FMODE_READ
;
1315 bdev
= lookup_bdev(path
);
1319 if (!(flags
& MS_RDONLY
))
1320 mode
|= FMODE_WRITE
;
1321 error
= blkdev_get(bdev
, mode
, 0);
1323 return ERR_PTR(error
);
1325 if (!(flags
& MS_RDONLY
) && bdev_read_only(bdev
))
1327 error
= bd_claim(bdev
, holder
);
1335 return ERR_PTR(error
);
1338 EXPORT_SYMBOL(open_bdev_excl
);
1341 * close_bdev_excl - release a blockdevice openen by open_bdev_excl()
1343 * @bdev: blockdevice to close
1345 * This is the counterpart to open_bdev_excl().
1347 void close_bdev_excl(struct block_device
*bdev
)
1353 EXPORT_SYMBOL(close_bdev_excl
);
1355 int __invalidate_device(struct block_device
*bdev
)
1357 struct super_block
*sb
= get_super(bdev
);
1362 * no need to lock the super, get_super holds the
1363 * read mutex so the filesystem cannot go away
1364 * under us (->put_super runs with the write lock
1367 shrink_dcache_sb(sb
);
1368 res
= invalidate_inodes(sb
);
1371 invalidate_bdev(bdev
, 0);
1374 EXPORT_SYMBOL(__invalidate_device
);