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
);
133 blkdev_get_blocks(struct inode
*inode
, sector_t iblock
,
134 struct buffer_head
*bh
, int create
)
136 sector_t end_block
= max_block(I_BDEV(inode
));
137 unsigned long max_blocks
= bh
->b_size
>> inode
->i_blkbits
;
139 if ((iblock
+ max_blocks
) > end_block
) {
140 max_blocks
= end_block
- iblock
;
141 if ((long)max_blocks
<= 0) {
143 return -EIO
; /* write fully beyond EOF */
145 * It is a read which is fully beyond EOF. We return
146 * a !buffer_mapped buffer
152 bh
->b_bdev
= I_BDEV(inode
);
153 bh
->b_blocknr
= iblock
;
154 bh
->b_size
= max_blocks
<< inode
->i_blkbits
;
156 set_buffer_mapped(bh
);
161 blkdev_direct_IO(int rw
, struct kiocb
*iocb
, const struct iovec
*iov
,
162 loff_t offset
, unsigned long nr_segs
)
164 struct file
*file
= iocb
->ki_filp
;
165 struct inode
*inode
= file
->f_mapping
->host
;
167 return blockdev_direct_IO_no_locking(rw
, iocb
, inode
, I_BDEV(inode
),
168 iov
, offset
, nr_segs
, blkdev_get_blocks
, NULL
);
171 static int blkdev_writepage(struct page
*page
, struct writeback_control
*wbc
)
173 return block_write_full_page(page
, blkdev_get_block
, wbc
);
176 static int blkdev_readpage(struct file
* file
, struct page
* page
)
178 return block_read_full_page(page
, blkdev_get_block
);
181 static int blkdev_prepare_write(struct file
*file
, struct page
*page
, unsigned from
, unsigned to
)
183 return block_prepare_write(page
, from
, to
, blkdev_get_block
);
186 static int blkdev_commit_write(struct file
*file
, struct page
*page
, unsigned from
, unsigned to
)
188 return block_commit_write(page
, from
, to
);
193 * for a block special file file->f_path.dentry->d_inode->i_size is zero
194 * so we compute the size by hand (just as in block_read/write above)
196 static loff_t
block_llseek(struct file
*file
, loff_t offset
, int origin
)
198 struct inode
*bd_inode
= file
->f_mapping
->host
;
202 mutex_lock(&bd_inode
->i_mutex
);
203 size
= i_size_read(bd_inode
);
210 offset
+= file
->f_pos
;
213 if (offset
>= 0 && offset
<= size
) {
214 if (offset
!= file
->f_pos
) {
215 file
->f_pos
= offset
;
219 mutex_unlock(&bd_inode
->i_mutex
);
224 * Filp is never NULL; the only case when ->fsync() is called with
225 * NULL first argument is nfsd_sync_dir() and that's not a directory.
228 static int block_fsync(struct file
*filp
, struct dentry
*dentry
, int datasync
)
230 return sync_blockdev(I_BDEV(filp
->f_mapping
->host
));
237 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(bdev_lock
);
238 static struct kmem_cache
* bdev_cachep __read_mostly
;
240 static struct inode
*bdev_alloc_inode(struct super_block
*sb
)
242 struct bdev_inode
*ei
= kmem_cache_alloc(bdev_cachep
, GFP_KERNEL
);
245 return &ei
->vfs_inode
;
248 static void bdev_destroy_inode(struct inode
*inode
)
250 struct bdev_inode
*bdi
= BDEV_I(inode
);
252 bdi
->bdev
.bd_inode_backing_dev_info
= NULL
;
253 kmem_cache_free(bdev_cachep
, bdi
);
256 static void init_once(void * foo
, struct kmem_cache
* cachep
, unsigned long flags
)
258 struct bdev_inode
*ei
= (struct bdev_inode
*) foo
;
259 struct block_device
*bdev
= &ei
->bdev
;
261 if ((flags
& (SLAB_CTOR_VERIFY
|SLAB_CTOR_CONSTRUCTOR
)) ==
262 SLAB_CTOR_CONSTRUCTOR
)
264 memset(bdev
, 0, sizeof(*bdev
));
265 mutex_init(&bdev
->bd_mutex
);
266 mutex_init(&bdev
->bd_mount_mutex
);
267 INIT_LIST_HEAD(&bdev
->bd_inodes
);
268 INIT_LIST_HEAD(&bdev
->bd_list
);
270 INIT_LIST_HEAD(&bdev
->bd_holder_list
);
272 inode_init_once(&ei
->vfs_inode
);
276 static inline void __bd_forget(struct inode
*inode
)
278 list_del_init(&inode
->i_devices
);
279 inode
->i_bdev
= NULL
;
280 inode
->i_mapping
= &inode
->i_data
;
283 static void bdev_clear_inode(struct inode
*inode
)
285 struct block_device
*bdev
= &BDEV_I(inode
)->bdev
;
287 spin_lock(&bdev_lock
);
288 while ( (p
= bdev
->bd_inodes
.next
) != &bdev
->bd_inodes
) {
289 __bd_forget(list_entry(p
, struct inode
, i_devices
));
291 list_del_init(&bdev
->bd_list
);
292 spin_unlock(&bdev_lock
);
295 static struct super_operations bdev_sops
= {
296 .statfs
= simple_statfs
,
297 .alloc_inode
= bdev_alloc_inode
,
298 .destroy_inode
= bdev_destroy_inode
,
299 .drop_inode
= generic_delete_inode
,
300 .clear_inode
= bdev_clear_inode
,
303 static int bd_get_sb(struct file_system_type
*fs_type
,
304 int flags
, const char *dev_name
, void *data
, struct vfsmount
*mnt
)
306 return get_sb_pseudo(fs_type
, "bdev:", &bdev_sops
, 0x62646576, mnt
);
309 static struct file_system_type bd_type
= {
312 .kill_sb
= kill_anon_super
,
315 static struct vfsmount
*bd_mnt __read_mostly
;
316 struct super_block
*blockdev_superblock
;
318 void __init
bdev_cache_init(void)
321 bdev_cachep
= kmem_cache_create("bdev_cache", sizeof(struct bdev_inode
),
322 0, (SLAB_HWCACHE_ALIGN
|SLAB_RECLAIM_ACCOUNT
|
323 SLAB_MEM_SPREAD
|SLAB_PANIC
),
325 err
= register_filesystem(&bd_type
);
327 panic("Cannot register bdev pseudo-fs");
328 bd_mnt
= kern_mount(&bd_type
);
329 err
= PTR_ERR(bd_mnt
);
331 panic("Cannot create bdev pseudo-fs");
332 blockdev_superblock
= bd_mnt
->mnt_sb
; /* For writeback */
336 * Most likely _very_ bad one - but then it's hardly critical for small
337 * /dev and can be fixed when somebody will need really large one.
338 * Keep in mind that it will be fed through icache hash function too.
340 static inline unsigned long hash(dev_t dev
)
342 return MAJOR(dev
)+MINOR(dev
);
345 static int bdev_test(struct inode
*inode
, void *data
)
347 return BDEV_I(inode
)->bdev
.bd_dev
== *(dev_t
*)data
;
350 static int bdev_set(struct inode
*inode
, void *data
)
352 BDEV_I(inode
)->bdev
.bd_dev
= *(dev_t
*)data
;
356 static LIST_HEAD(all_bdevs
);
358 struct block_device
*bdget(dev_t dev
)
360 struct block_device
*bdev
;
363 inode
= iget5_locked(bd_mnt
->mnt_sb
, hash(dev
),
364 bdev_test
, bdev_set
, &dev
);
369 bdev
= &BDEV_I(inode
)->bdev
;
371 if (inode
->i_state
& I_NEW
) {
372 bdev
->bd_contains
= NULL
;
373 bdev
->bd_inode
= inode
;
374 bdev
->bd_block_size
= (1 << inode
->i_blkbits
);
375 bdev
->bd_part_count
= 0;
376 bdev
->bd_invalidated
= 0;
377 inode
->i_mode
= S_IFBLK
;
379 inode
->i_bdev
= bdev
;
380 inode
->i_data
.a_ops
= &def_blk_aops
;
381 mapping_set_gfp_mask(&inode
->i_data
, GFP_USER
);
382 inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
383 spin_lock(&bdev_lock
);
384 list_add(&bdev
->bd_list
, &all_bdevs
);
385 spin_unlock(&bdev_lock
);
386 unlock_new_inode(inode
);
391 EXPORT_SYMBOL(bdget
);
393 long nr_blockdev_pages(void)
397 spin_lock(&bdev_lock
);
398 list_for_each(p
, &all_bdevs
) {
399 struct block_device
*bdev
;
400 bdev
= list_entry(p
, struct block_device
, bd_list
);
401 ret
+= bdev
->bd_inode
->i_mapping
->nrpages
;
403 spin_unlock(&bdev_lock
);
407 void bdput(struct block_device
*bdev
)
409 iput(bdev
->bd_inode
);
412 EXPORT_SYMBOL(bdput
);
414 static struct block_device
*bd_acquire(struct inode
*inode
)
416 struct block_device
*bdev
;
418 spin_lock(&bdev_lock
);
419 bdev
= inode
->i_bdev
;
421 atomic_inc(&bdev
->bd_inode
->i_count
);
422 spin_unlock(&bdev_lock
);
425 spin_unlock(&bdev_lock
);
427 bdev
= bdget(inode
->i_rdev
);
429 spin_lock(&bdev_lock
);
430 if (!inode
->i_bdev
) {
432 * We take an additional bd_inode->i_count for inode,
433 * and it's released in clear_inode() of inode.
434 * So, we can access it via ->i_mapping always
437 atomic_inc(&bdev
->bd_inode
->i_count
);
438 inode
->i_bdev
= bdev
;
439 inode
->i_mapping
= bdev
->bd_inode
->i_mapping
;
440 list_add(&inode
->i_devices
, &bdev
->bd_inodes
);
442 spin_unlock(&bdev_lock
);
447 /* Call when you free inode */
449 void bd_forget(struct inode
*inode
)
451 struct block_device
*bdev
= NULL
;
453 spin_lock(&bdev_lock
);
455 if (inode
->i_sb
!= blockdev_superblock
)
456 bdev
= inode
->i_bdev
;
459 spin_unlock(&bdev_lock
);
462 iput(bdev
->bd_inode
);
465 int bd_claim(struct block_device
*bdev
, void *holder
)
468 spin_lock(&bdev_lock
);
470 /* first decide result */
471 if (bdev
->bd_holder
== holder
)
472 res
= 0; /* already a holder */
473 else if (bdev
->bd_holder
!= NULL
)
474 res
= -EBUSY
; /* held by someone else */
475 else if (bdev
->bd_contains
== bdev
)
476 res
= 0; /* is a whole device which isn't held */
478 else if (bdev
->bd_contains
->bd_holder
== bd_claim
)
479 res
= 0; /* is a partition of a device that is being partitioned */
480 else if (bdev
->bd_contains
->bd_holder
!= NULL
)
481 res
= -EBUSY
; /* is a partition of a held device */
483 res
= 0; /* is a partition of an un-held device */
485 /* now impose change */
487 /* note that for a whole device bd_holders
488 * will be incremented twice, and bd_holder will
489 * be set to bd_claim before being set to holder
491 bdev
->bd_contains
->bd_holders
++;
492 bdev
->bd_contains
->bd_holder
= bd_claim
;
494 bdev
->bd_holder
= holder
;
496 spin_unlock(&bdev_lock
);
500 EXPORT_SYMBOL(bd_claim
);
502 void bd_release(struct block_device
*bdev
)
504 spin_lock(&bdev_lock
);
505 if (!--bdev
->bd_contains
->bd_holders
)
506 bdev
->bd_contains
->bd_holder
= NULL
;
507 if (!--bdev
->bd_holders
)
508 bdev
->bd_holder
= NULL
;
509 spin_unlock(&bdev_lock
);
512 EXPORT_SYMBOL(bd_release
);
516 * Functions for bd_claim_by_kobject / bd_release_from_kobject
518 * If a kobject is passed to bd_claim_by_kobject()
519 * and the kobject has a parent directory,
520 * following symlinks are created:
521 * o from the kobject to the claimed bdev
522 * o from "holders" directory of the bdev to the parent of the kobject
523 * bd_release_from_kobject() removes these symlinks.
526 * If /dev/dm-0 maps to /dev/sda, kobject corresponding to
527 * /sys/block/dm-0/slaves is passed to bd_claim_by_kobject(), then:
528 * /sys/block/dm-0/slaves/sda --> /sys/block/sda
529 * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
532 static struct kobject
*bdev_get_kobj(struct block_device
*bdev
)
534 if (bdev
->bd_contains
!= bdev
)
535 return kobject_get(&bdev
->bd_part
->kobj
);
537 return kobject_get(&bdev
->bd_disk
->kobj
);
540 static struct kobject
*bdev_get_holder(struct block_device
*bdev
)
542 if (bdev
->bd_contains
!= bdev
)
543 return kobject_get(bdev
->bd_part
->holder_dir
);
545 return kobject_get(bdev
->bd_disk
->holder_dir
);
548 static int add_symlink(struct kobject
*from
, struct kobject
*to
)
552 return sysfs_create_link(from
, to
, kobject_name(to
));
555 static void del_symlink(struct kobject
*from
, struct kobject
*to
)
559 sysfs_remove_link(from
, kobject_name(to
));
563 * 'struct bd_holder' contains pointers to kobjects symlinked by
564 * bd_claim_by_kobject.
565 * It's connected to bd_holder_list which is protected by bdev->bd_sem.
568 struct list_head list
; /* chain of holders of the bdev */
569 int count
; /* references from the holder */
570 struct kobject
*sdir
; /* holder object, e.g. "/block/dm-0/slaves" */
571 struct kobject
*hdev
; /* e.g. "/block/dm-0" */
572 struct kobject
*hdir
; /* e.g. "/block/sda/holders" */
573 struct kobject
*sdev
; /* e.g. "/block/sda" */
577 * Get references of related kobjects at once.
578 * Returns 1 on success. 0 on failure.
580 * Should call bd_holder_release_dirs() after successful use.
582 static int bd_holder_grab_dirs(struct block_device
*bdev
,
583 struct bd_holder
*bo
)
588 bo
->sdir
= kobject_get(bo
->sdir
);
592 bo
->hdev
= kobject_get(bo
->sdir
->parent
);
596 bo
->sdev
= bdev_get_kobj(bdev
);
600 bo
->hdir
= bdev_get_holder(bdev
);
607 kobject_put(bo
->sdev
);
609 kobject_put(bo
->hdev
);
611 kobject_put(bo
->sdir
);
616 /* Put references of related kobjects at once. */
617 static void bd_holder_release_dirs(struct bd_holder
*bo
)
619 kobject_put(bo
->hdir
);
620 kobject_put(bo
->sdev
);
621 kobject_put(bo
->hdev
);
622 kobject_put(bo
->sdir
);
625 static struct bd_holder
*alloc_bd_holder(struct kobject
*kobj
)
627 struct bd_holder
*bo
;
629 bo
= kzalloc(sizeof(*bo
), GFP_KERNEL
);
639 static void free_bd_holder(struct bd_holder
*bo
)
645 * find_bd_holder - find matching struct bd_holder from the block device
647 * @bdev: struct block device to be searched
648 * @bo: target struct bd_holder
650 * Returns matching entry with @bo in @bdev->bd_holder_list.
651 * If found, increment the reference count and return the pointer.
652 * If not found, returns NULL.
654 static struct bd_holder
*find_bd_holder(struct block_device
*bdev
,
655 struct bd_holder
*bo
)
657 struct bd_holder
*tmp
;
659 list_for_each_entry(tmp
, &bdev
->bd_holder_list
, list
)
660 if (tmp
->sdir
== bo
->sdir
) {
669 * add_bd_holder - create sysfs symlinks for bd_claim() relationship
671 * @bdev: block device to be bd_claimed
672 * @bo: preallocated and initialized by alloc_bd_holder()
674 * Add @bo to @bdev->bd_holder_list, create symlinks.
676 * Returns 0 if symlinks are created.
677 * Returns -ve if something fails.
679 static int add_bd_holder(struct block_device
*bdev
, struct bd_holder
*bo
)
686 if (!bd_holder_grab_dirs(bdev
, bo
))
689 ret
= add_symlink(bo
->sdir
, bo
->sdev
);
691 ret
= add_symlink(bo
->hdir
, bo
->hdev
);
693 del_symlink(bo
->sdir
, bo
->sdev
);
696 list_add_tail(&bo
->list
, &bdev
->bd_holder_list
);
701 * del_bd_holder - delete sysfs symlinks for bd_claim() relationship
703 * @bdev: block device to be bd_claimed
704 * @kobj: holder's kobject
706 * If there is matching entry with @kobj in @bdev->bd_holder_list
707 * and no other bd_claim() from the same kobject,
708 * remove the struct bd_holder from the list, delete symlinks for it.
710 * Returns a pointer to the struct bd_holder when it's removed from the list
711 * and ready to be freed.
712 * Returns NULL if matching claim isn't found or there is other bd_claim()
713 * by the same kobject.
715 static struct bd_holder
*del_bd_holder(struct block_device
*bdev
,
716 struct kobject
*kobj
)
718 struct bd_holder
*bo
;
720 list_for_each_entry(bo
, &bdev
->bd_holder_list
, list
) {
721 if (bo
->sdir
== kobj
) {
723 BUG_ON(bo
->count
< 0);
726 del_symlink(bo
->sdir
, bo
->sdev
);
727 del_symlink(bo
->hdir
, bo
->hdev
);
728 bd_holder_release_dirs(bo
);
739 * bd_claim_by_kobject - bd_claim() with additional kobject signature
741 * @bdev: block device to be claimed
742 * @holder: holder's signature
743 * @kobj: holder's kobject
745 * Do bd_claim() and if it succeeds, create sysfs symlinks between
746 * the bdev and the holder's kobject.
747 * Use bd_release_from_kobject() when relesing the claimed bdev.
749 * Returns 0 on success. (same as bd_claim())
750 * Returns errno on failure.
752 static int bd_claim_by_kobject(struct block_device
*bdev
, void *holder
,
753 struct kobject
*kobj
)
756 struct bd_holder
*bo
, *found
;
761 bo
= alloc_bd_holder(kobj
);
765 mutex_lock(&bdev
->bd_mutex
);
766 res
= bd_claim(bdev
, holder
);
768 found
= find_bd_holder(bdev
, bo
);
770 res
= add_bd_holder(bdev
, bo
);
778 mutex_unlock(&bdev
->bd_mutex
);
784 * bd_release_from_kobject - bd_release() with additional kobject signature
786 * @bdev: block device to be released
787 * @kobj: holder's kobject
789 * Do bd_release() and remove sysfs symlinks created by bd_claim_by_kobject().
791 static void bd_release_from_kobject(struct block_device
*bdev
,
792 struct kobject
*kobj
)
794 struct bd_holder
*bo
;
799 mutex_lock(&bdev
->bd_mutex
);
801 if ((bo
= del_bd_holder(bdev
, kobj
)))
803 mutex_unlock(&bdev
->bd_mutex
);
807 * bd_claim_by_disk - wrapper function for bd_claim_by_kobject()
809 * @bdev: block device to be claimed
810 * @holder: holder's signature
811 * @disk: holder's gendisk
813 * Call bd_claim_by_kobject() with getting @disk->slave_dir.
815 int bd_claim_by_disk(struct block_device
*bdev
, void *holder
,
816 struct gendisk
*disk
)
818 return bd_claim_by_kobject(bdev
, holder
, kobject_get(disk
->slave_dir
));
820 EXPORT_SYMBOL_GPL(bd_claim_by_disk
);
823 * bd_release_from_disk - wrapper function for bd_release_from_kobject()
825 * @bdev: block device to be claimed
826 * @disk: holder's gendisk
828 * Call bd_release_from_kobject() and put @disk->slave_dir.
830 void bd_release_from_disk(struct block_device
*bdev
, struct gendisk
*disk
)
832 bd_release_from_kobject(bdev
, disk
->slave_dir
);
833 kobject_put(disk
->slave_dir
);
835 EXPORT_SYMBOL_GPL(bd_release_from_disk
);
839 * Tries to open block device by device number. Use it ONLY if you
840 * really do not have anything better - i.e. when you are behind a
841 * truly sucky interface and all you are given is a device number. _Never_
842 * to be used for internal purposes. If you ever need it - reconsider
845 struct block_device
*open_by_devnum(dev_t dev
, unsigned mode
)
847 struct block_device
*bdev
= bdget(dev
);
849 int flags
= mode
& FMODE_WRITE
? O_RDWR
: O_RDONLY
;
851 err
= blkdev_get(bdev
, mode
, flags
);
852 return err
? ERR_PTR(err
) : bdev
;
855 EXPORT_SYMBOL(open_by_devnum
);
858 * This routine checks whether a removable media has been changed,
859 * and invalidates all buffer-cache-entries in that case. This
860 * is a relatively slow routine, so we have to try to minimize using
861 * it. Thus it is called only upon a 'mount' or 'open'. This
862 * is the best way of combining speed and utility, I think.
863 * People changing diskettes in the middle of an operation deserve
866 int check_disk_change(struct block_device
*bdev
)
868 struct gendisk
*disk
= bdev
->bd_disk
;
869 struct block_device_operations
* bdops
= disk
->fops
;
871 if (!bdops
->media_changed
)
873 if (!bdops
->media_changed(bdev
->bd_disk
))
876 if (__invalidate_device(bdev
))
877 printk("VFS: busy inodes on changed media.\n");
879 if (bdops
->revalidate_disk
)
880 bdops
->revalidate_disk(bdev
->bd_disk
);
881 if (bdev
->bd_disk
->minors
> 1)
882 bdev
->bd_invalidated
= 1;
886 EXPORT_SYMBOL(check_disk_change
);
888 void bd_set_size(struct block_device
*bdev
, loff_t size
)
890 unsigned bsize
= bdev_hardsect_size(bdev
);
892 bdev
->bd_inode
->i_size
= size
;
893 while (bsize
< PAGE_CACHE_SIZE
) {
898 bdev
->bd_block_size
= bsize
;
899 bdev
->bd_inode
->i_blkbits
= blksize_bits(bsize
);
901 EXPORT_SYMBOL(bd_set_size
);
903 static int __blkdev_get(struct block_device
*bdev
, mode_t mode
, unsigned flags
,
905 static int __blkdev_put(struct block_device
*bdev
, int for_part
);
907 static int do_open(struct block_device
*bdev
, struct file
*file
, int for_part
)
909 struct module
*owner
= NULL
;
910 struct gendisk
*disk
;
914 file
->f_mapping
= bdev
->bd_inode
->i_mapping
;
916 disk
= get_gendisk(bdev
->bd_dev
, &part
);
922 owner
= disk
->fops
->owner
;
924 mutex_lock_nested(&bdev
->bd_mutex
, for_part
);
925 if (!bdev
->bd_openers
) {
926 bdev
->bd_disk
= disk
;
927 bdev
->bd_contains
= bdev
;
929 struct backing_dev_info
*bdi
;
930 if (disk
->fops
->open
) {
931 ret
= disk
->fops
->open(bdev
->bd_inode
, file
);
935 if (!bdev
->bd_openers
) {
936 bd_set_size(bdev
,(loff_t
)get_capacity(disk
)<<9);
937 bdi
= blk_get_backing_dev_info(bdev
);
939 bdi
= &default_backing_dev_info
;
940 bdev
->bd_inode
->i_data
.backing_dev_info
= bdi
;
942 if (bdev
->bd_invalidated
)
943 rescan_partitions(disk
, bdev
);
946 struct block_device
*whole
;
947 whole
= bdget_disk(disk
, 0);
952 ret
= __blkdev_get(whole
, file
->f_mode
, file
->f_flags
, 1);
955 bdev
->bd_contains
= whole
;
956 p
= disk
->part
[part
- 1];
957 bdev
->bd_inode
->i_data
.backing_dev_info
=
958 whole
->bd_inode
->i_data
.backing_dev_info
;
959 if (!(disk
->flags
& GENHD_FL_UP
) || !p
|| !p
->nr_sects
) {
963 kobject_get(&p
->kobj
);
965 bd_set_size(bdev
, (loff_t
) p
->nr_sects
<< 9);
970 if (bdev
->bd_contains
== bdev
) {
971 if (bdev
->bd_disk
->fops
->open
) {
972 ret
= bdev
->bd_disk
->fops
->open(bdev
->bd_inode
, file
);
976 if (bdev
->bd_invalidated
)
977 rescan_partitions(bdev
->bd_disk
, bdev
);
982 bdev
->bd_part_count
++;
983 mutex_unlock(&bdev
->bd_mutex
);
988 bdev
->bd_disk
= NULL
;
989 bdev
->bd_inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
990 if (bdev
!= bdev
->bd_contains
)
991 __blkdev_put(bdev
->bd_contains
, 1);
992 bdev
->bd_contains
= NULL
;
996 mutex_unlock(&bdev
->bd_mutex
);
1003 static int __blkdev_get(struct block_device
*bdev
, mode_t mode
, unsigned flags
,
1007 * This crockload is due to bad choice of ->open() type.
1009 * For now, block device ->open() routine must _not_
1010 * examine anything in 'inode' argument except ->i_rdev.
1012 struct file fake_file
= {};
1013 struct dentry fake_dentry
= {};
1014 fake_file
.f_mode
= mode
;
1015 fake_file
.f_flags
= flags
;
1016 fake_file
.f_path
.dentry
= &fake_dentry
;
1017 fake_dentry
.d_inode
= bdev
->bd_inode
;
1019 return do_open(bdev
, &fake_file
, for_part
);
1022 int blkdev_get(struct block_device
*bdev
, mode_t mode
, unsigned flags
)
1024 return __blkdev_get(bdev
, mode
, flags
, 0);
1026 EXPORT_SYMBOL(blkdev_get
);
1028 static int blkdev_open(struct inode
* inode
, struct file
* filp
)
1030 struct block_device
*bdev
;
1034 * Preserve backwards compatibility and allow large file access
1035 * even if userspace doesn't ask for it explicitly. Some mkfs
1036 * binary needs it. We might want to drop this workaround
1037 * during an unstable branch.
1039 filp
->f_flags
|= O_LARGEFILE
;
1041 bdev
= bd_acquire(inode
);
1045 res
= do_open(bdev
, filp
, 0);
1049 if (!(filp
->f_flags
& O_EXCL
) )
1052 if (!(res
= bd_claim(bdev
, filp
)))
1059 static int __blkdev_put(struct block_device
*bdev
, int for_part
)
1062 struct inode
*bd_inode
= bdev
->bd_inode
;
1063 struct gendisk
*disk
= bdev
->bd_disk
;
1064 struct block_device
*victim
= NULL
;
1066 mutex_lock_nested(&bdev
->bd_mutex
, for_part
);
1069 bdev
->bd_part_count
--;
1071 if (!--bdev
->bd_openers
) {
1072 sync_blockdev(bdev
);
1075 if (bdev
->bd_contains
== bdev
) {
1076 if (disk
->fops
->release
)
1077 ret
= disk
->fops
->release(bd_inode
, NULL
);
1079 if (!bdev
->bd_openers
) {
1080 struct module
*owner
= disk
->fops
->owner
;
1085 if (bdev
->bd_contains
!= bdev
) {
1086 kobject_put(&bdev
->bd_part
->kobj
);
1087 bdev
->bd_part
= NULL
;
1089 bdev
->bd_disk
= NULL
;
1090 bdev
->bd_inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
1091 if (bdev
!= bdev
->bd_contains
)
1092 victim
= bdev
->bd_contains
;
1093 bdev
->bd_contains
= NULL
;
1096 mutex_unlock(&bdev
->bd_mutex
);
1099 __blkdev_put(victim
, 1);
1103 int blkdev_put(struct block_device
*bdev
)
1105 return __blkdev_put(bdev
, 0);
1107 EXPORT_SYMBOL(blkdev_put
);
1109 static int blkdev_close(struct inode
* inode
, struct file
* filp
)
1111 struct block_device
*bdev
= I_BDEV(filp
->f_mapping
->host
);
1112 if (bdev
->bd_holder
== filp
)
1114 return blkdev_put(bdev
);
1117 static long block_ioctl(struct file
*file
, unsigned cmd
, unsigned long arg
)
1119 return blkdev_ioctl(file
->f_mapping
->host
, file
, cmd
, arg
);
1122 const struct address_space_operations def_blk_aops
= {
1123 .readpage
= blkdev_readpage
,
1124 .writepage
= blkdev_writepage
,
1125 .sync_page
= block_sync_page
,
1126 .prepare_write
= blkdev_prepare_write
,
1127 .commit_write
= blkdev_commit_write
,
1128 .writepages
= generic_writepages
,
1129 .direct_IO
= blkdev_direct_IO
,
1132 const struct file_operations def_blk_fops
= {
1133 .open
= blkdev_open
,
1134 .release
= blkdev_close
,
1135 .llseek
= block_llseek
,
1136 .read
= do_sync_read
,
1137 .write
= do_sync_write
,
1138 .aio_read
= generic_file_aio_read
,
1139 .aio_write
= generic_file_aio_write_nolock
,
1140 .mmap
= generic_file_mmap
,
1141 .fsync
= block_fsync
,
1142 .unlocked_ioctl
= block_ioctl
,
1143 #ifdef CONFIG_COMPAT
1144 .compat_ioctl
= compat_blkdev_ioctl
,
1146 .sendfile
= generic_file_sendfile
,
1147 .splice_read
= generic_file_splice_read
,
1148 .splice_write
= generic_file_splice_write
,
1151 int ioctl_by_bdev(struct block_device
*bdev
, unsigned cmd
, unsigned long arg
)
1154 mm_segment_t old_fs
= get_fs();
1156 res
= blkdev_ioctl(bdev
->bd_inode
, NULL
, cmd
, arg
);
1161 EXPORT_SYMBOL(ioctl_by_bdev
);
1164 * lookup_bdev - lookup a struct block_device by name
1166 * @path: special file representing the block device
1168 * Get a reference to the blockdevice at @path in the current
1169 * namespace if possible and return it. Return ERR_PTR(error)
1172 struct block_device
*lookup_bdev(const char *path
)
1174 struct block_device
*bdev
;
1175 struct inode
*inode
;
1176 struct nameidata nd
;
1179 if (!path
|| !*path
)
1180 return ERR_PTR(-EINVAL
);
1182 error
= path_lookup(path
, LOOKUP_FOLLOW
, &nd
);
1184 return ERR_PTR(error
);
1186 inode
= nd
.dentry
->d_inode
;
1188 if (!S_ISBLK(inode
->i_mode
))
1191 if (nd
.mnt
->mnt_flags
& MNT_NODEV
)
1194 bdev
= bd_acquire(inode
);
1201 bdev
= ERR_PTR(error
);
1206 * open_bdev_excl - open a block device by name and set it up for use
1208 * @path: special file representing the block device
1209 * @flags: %MS_RDONLY for opening read-only
1210 * @holder: owner for exclusion
1212 * Open the blockdevice described by the special file at @path, claim it
1215 struct block_device
*open_bdev_excl(const char *path
, int flags
, void *holder
)
1217 struct block_device
*bdev
;
1218 mode_t mode
= FMODE_READ
;
1221 bdev
= lookup_bdev(path
);
1225 if (!(flags
& MS_RDONLY
))
1226 mode
|= FMODE_WRITE
;
1227 error
= blkdev_get(bdev
, mode
, 0);
1229 return ERR_PTR(error
);
1231 if (!(flags
& MS_RDONLY
) && bdev_read_only(bdev
))
1233 error
= bd_claim(bdev
, holder
);
1241 return ERR_PTR(error
);
1244 EXPORT_SYMBOL(open_bdev_excl
);
1247 * close_bdev_excl - release a blockdevice openen by open_bdev_excl()
1249 * @bdev: blockdevice to close
1251 * This is the counterpart to open_bdev_excl().
1253 void close_bdev_excl(struct block_device
*bdev
)
1259 EXPORT_SYMBOL(close_bdev_excl
);
1261 int __invalidate_device(struct block_device
*bdev
)
1263 struct super_block
*sb
= get_super(bdev
);
1268 * no need to lock the super, get_super holds the
1269 * read mutex so the filesystem cannot go away
1270 * under us (->put_super runs with the write lock
1273 shrink_dcache_sb(sb
);
1274 res
= invalidate_inodes(sb
);
1277 invalidate_bdev(bdev
, 0);
1280 EXPORT_SYMBOL(__invalidate_device
);