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/device_cgroup.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/pagevec.h>
21 #include <linux/writeback.h>
22 #include <linux/mpage.h>
23 #include <linux/mount.h>
24 #include <linux/uio.h>
25 #include <linux/namei.h>
26 #include <linux/log2.h>
27 #include <linux/kmemleak.h>
28 #include <asm/uaccess.h>
32 struct block_device bdev
;
33 struct inode vfs_inode
;
36 static const struct address_space_operations def_blk_aops
;
38 static inline struct bdev_inode
*BDEV_I(struct inode
*inode
)
40 return container_of(inode
, struct bdev_inode
, vfs_inode
);
43 inline struct block_device
*I_BDEV(struct inode
*inode
)
45 return &BDEV_I(inode
)->bdev
;
48 EXPORT_SYMBOL(I_BDEV
);
51 * move the inode from it's current bdi to the a new bdi. if the inode is dirty
52 * we need to move it onto the dirty list of @dst so that the inode is always
55 static void bdev_inode_switch_bdi(struct inode
*inode
,
56 struct backing_dev_info
*dst
)
58 spin_lock(&inode_lock
);
59 inode
->i_data
.backing_dev_info
= dst
;
60 if (inode
->i_state
& I_DIRTY
)
61 list_move(&inode
->i_wb_list
, &dst
->wb
.b_dirty
);
62 spin_unlock(&inode_lock
);
65 static sector_t
max_block(struct block_device
*bdev
)
67 sector_t retval
= ~((sector_t
)0);
68 loff_t sz
= i_size_read(bdev
->bd_inode
);
71 unsigned int size
= block_size(bdev
);
72 unsigned int sizebits
= blksize_bits(size
);
73 retval
= (sz
>> sizebits
);
78 /* Kill _all_ buffers and pagecache , dirty or not.. */
79 static void kill_bdev(struct block_device
*bdev
)
81 if (bdev
->bd_inode
->i_mapping
->nrpages
== 0)
84 truncate_inode_pages(bdev
->bd_inode
->i_mapping
, 0);
87 int set_blocksize(struct block_device
*bdev
, int size
)
89 /* Size must be a power of two, and between 512 and PAGE_SIZE */
90 if (size
> PAGE_SIZE
|| size
< 512 || !is_power_of_2(size
))
93 /* Size cannot be smaller than the size supported by the device */
94 if (size
< bdev_logical_block_size(bdev
))
97 /* Don't change the size if it is same as current */
98 if (bdev
->bd_block_size
!= size
) {
100 bdev
->bd_block_size
= size
;
101 bdev
->bd_inode
->i_blkbits
= blksize_bits(size
);
107 EXPORT_SYMBOL(set_blocksize
);
109 int sb_set_blocksize(struct super_block
*sb
, int size
)
111 if (set_blocksize(sb
->s_bdev
, size
))
113 /* If we get here, we know size is power of two
114 * and it's value is between 512 and PAGE_SIZE */
115 sb
->s_blocksize
= size
;
116 sb
->s_blocksize_bits
= blksize_bits(size
);
117 return sb
->s_blocksize
;
120 EXPORT_SYMBOL(sb_set_blocksize
);
122 int sb_min_blocksize(struct super_block
*sb
, int size
)
124 int minsize
= bdev_logical_block_size(sb
->s_bdev
);
127 return sb_set_blocksize(sb
, size
);
130 EXPORT_SYMBOL(sb_min_blocksize
);
133 blkdev_get_block(struct inode
*inode
, sector_t iblock
,
134 struct buffer_head
*bh
, int create
)
136 if (iblock
>= max_block(I_BDEV(inode
))) {
141 * for reads, we're just trying to fill a partial page.
142 * return a hole, they will have to call get_block again
143 * before they can fill it, and they will get -EIO at that
148 bh
->b_bdev
= I_BDEV(inode
);
149 bh
->b_blocknr
= iblock
;
150 set_buffer_mapped(bh
);
155 blkdev_get_blocks(struct inode
*inode
, sector_t iblock
,
156 struct buffer_head
*bh
, int create
)
158 sector_t end_block
= max_block(I_BDEV(inode
));
159 unsigned long max_blocks
= bh
->b_size
>> inode
->i_blkbits
;
161 if ((iblock
+ max_blocks
) > end_block
) {
162 max_blocks
= end_block
- iblock
;
163 if ((long)max_blocks
<= 0) {
165 return -EIO
; /* write fully beyond EOF */
167 * It is a read which is fully beyond EOF. We return
168 * a !buffer_mapped buffer
174 bh
->b_bdev
= I_BDEV(inode
);
175 bh
->b_blocknr
= iblock
;
176 bh
->b_size
= max_blocks
<< inode
->i_blkbits
;
178 set_buffer_mapped(bh
);
183 blkdev_direct_IO(int rw
, struct kiocb
*iocb
, const struct iovec
*iov
,
184 loff_t offset
, unsigned long nr_segs
)
186 struct file
*file
= iocb
->ki_filp
;
187 struct inode
*inode
= file
->f_mapping
->host
;
189 return __blockdev_direct_IO(rw
, iocb
, inode
, I_BDEV(inode
), iov
, offset
,
190 nr_segs
, blkdev_get_blocks
, NULL
, NULL
, 0);
193 int __sync_blockdev(struct block_device
*bdev
, int wait
)
198 return filemap_flush(bdev
->bd_inode
->i_mapping
);
199 return filemap_write_and_wait(bdev
->bd_inode
->i_mapping
);
203 * Write out and wait upon all the dirty data associated with a block
204 * device via its mapping. Does not take the superblock lock.
206 int sync_blockdev(struct block_device
*bdev
)
208 return __sync_blockdev(bdev
, 1);
210 EXPORT_SYMBOL(sync_blockdev
);
213 * Write out and wait upon all dirty data associated with this
214 * device. Filesystem data as well as the underlying block
215 * device. Takes the superblock lock.
217 int fsync_bdev(struct block_device
*bdev
)
219 struct super_block
*sb
= get_super(bdev
);
221 int res
= sync_filesystem(sb
);
225 return sync_blockdev(bdev
);
227 EXPORT_SYMBOL(fsync_bdev
);
230 * freeze_bdev -- lock a filesystem and force it into a consistent state
231 * @bdev: blockdevice to lock
233 * If a superblock is found on this device, we take the s_umount semaphore
234 * on it to make sure nobody unmounts until the snapshot creation is done.
235 * The reference counter (bd_fsfreeze_count) guarantees that only the last
236 * unfreeze process can unfreeze the frozen filesystem actually when multiple
237 * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
238 * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
241 struct super_block
*freeze_bdev(struct block_device
*bdev
)
243 struct super_block
*sb
;
246 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
247 if (++bdev
->bd_fsfreeze_count
> 1) {
249 * We don't even need to grab a reference - the first call
250 * to freeze_bdev grab an active reference and only the last
251 * thaw_bdev drops it.
253 sb
= get_super(bdev
);
255 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
259 sb
= get_active_super(bdev
);
262 error
= freeze_super(sb
);
264 deactivate_super(sb
);
265 bdev
->bd_fsfreeze_count
--;
266 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
267 return ERR_PTR(error
);
269 deactivate_super(sb
);
272 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
273 return sb
; /* thaw_bdev releases s->s_umount */
275 EXPORT_SYMBOL(freeze_bdev
);
278 * thaw_bdev -- unlock filesystem
279 * @bdev: blockdevice to unlock
280 * @sb: associated superblock
282 * Unlocks the filesystem and marks it writeable again after freeze_bdev().
284 int thaw_bdev(struct block_device
*bdev
, struct super_block
*sb
)
288 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
289 if (!bdev
->bd_fsfreeze_count
)
293 if (--bdev
->bd_fsfreeze_count
> 0)
299 error
= thaw_super(sb
);
301 bdev
->bd_fsfreeze_count
++;
302 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
306 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
309 EXPORT_SYMBOL(thaw_bdev
);
311 static int blkdev_writepage(struct page
*page
, struct writeback_control
*wbc
)
313 return block_write_full_page(page
, blkdev_get_block
, wbc
);
316 static int blkdev_readpage(struct file
* file
, struct page
* page
)
318 return block_read_full_page(page
, blkdev_get_block
);
321 static int blkdev_write_begin(struct file
*file
, struct address_space
*mapping
,
322 loff_t pos
, unsigned len
, unsigned flags
,
323 struct page
**pagep
, void **fsdata
)
325 return block_write_begin(mapping
, pos
, len
, flags
, pagep
,
329 static int blkdev_write_end(struct file
*file
, struct address_space
*mapping
,
330 loff_t pos
, unsigned len
, unsigned copied
,
331 struct page
*page
, void *fsdata
)
334 ret
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
337 page_cache_release(page
);
344 * for a block special file file->f_path.dentry->d_inode->i_size is zero
345 * so we compute the size by hand (just as in block_read/write above)
347 static loff_t
block_llseek(struct file
*file
, loff_t offset
, int origin
)
349 struct inode
*bd_inode
= file
->f_mapping
->host
;
353 mutex_lock(&bd_inode
->i_mutex
);
354 size
= i_size_read(bd_inode
);
361 offset
+= file
->f_pos
;
364 if (offset
>= 0 && offset
<= size
) {
365 if (offset
!= file
->f_pos
) {
366 file
->f_pos
= offset
;
370 mutex_unlock(&bd_inode
->i_mutex
);
374 int blkdev_fsync(struct file
*filp
, int datasync
)
376 struct inode
*bd_inode
= filp
->f_mapping
->host
;
377 struct block_device
*bdev
= I_BDEV(bd_inode
);
381 * There is no need to serialise calls to blkdev_issue_flush with
382 * i_mutex and doing so causes performance issues with concurrent
383 * O_SYNC writers to a block device.
385 mutex_unlock(&bd_inode
->i_mutex
);
387 error
= blkdev_issue_flush(bdev
, GFP_KERNEL
, NULL
);
388 if (error
== -EOPNOTSUPP
)
391 mutex_lock(&bd_inode
->i_mutex
);
395 EXPORT_SYMBOL(blkdev_fsync
);
401 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(bdev_lock
);
402 static struct kmem_cache
* bdev_cachep __read_mostly
;
404 static struct inode
*bdev_alloc_inode(struct super_block
*sb
)
406 struct bdev_inode
*ei
= kmem_cache_alloc(bdev_cachep
, GFP_KERNEL
);
409 return &ei
->vfs_inode
;
412 static void bdev_destroy_inode(struct inode
*inode
)
414 struct bdev_inode
*bdi
= BDEV_I(inode
);
416 kmem_cache_free(bdev_cachep
, bdi
);
419 static void init_once(void *foo
)
421 struct bdev_inode
*ei
= (struct bdev_inode
*) foo
;
422 struct block_device
*bdev
= &ei
->bdev
;
424 memset(bdev
, 0, sizeof(*bdev
));
425 mutex_init(&bdev
->bd_mutex
);
426 INIT_LIST_HEAD(&bdev
->bd_inodes
);
427 INIT_LIST_HEAD(&bdev
->bd_list
);
429 INIT_LIST_HEAD(&bdev
->bd_holder_list
);
431 inode_init_once(&ei
->vfs_inode
);
432 /* Initialize mutex for freeze. */
433 mutex_init(&bdev
->bd_fsfreeze_mutex
);
436 static inline void __bd_forget(struct inode
*inode
)
438 list_del_init(&inode
->i_devices
);
439 inode
->i_bdev
= NULL
;
440 inode
->i_mapping
= &inode
->i_data
;
443 static void bdev_evict_inode(struct inode
*inode
)
445 struct block_device
*bdev
= &BDEV_I(inode
)->bdev
;
447 truncate_inode_pages(&inode
->i_data
, 0);
448 invalidate_inode_buffers(inode
); /* is it needed here? */
449 end_writeback(inode
);
450 spin_lock(&bdev_lock
);
451 while ( (p
= bdev
->bd_inodes
.next
) != &bdev
->bd_inodes
) {
452 __bd_forget(list_entry(p
, struct inode
, i_devices
));
454 list_del_init(&bdev
->bd_list
);
455 spin_unlock(&bdev_lock
);
458 static const struct super_operations bdev_sops
= {
459 .statfs
= simple_statfs
,
460 .alloc_inode
= bdev_alloc_inode
,
461 .destroy_inode
= bdev_destroy_inode
,
462 .drop_inode
= generic_delete_inode
,
463 .evict_inode
= bdev_evict_inode
,
466 static struct dentry
*bd_mount(struct file_system_type
*fs_type
,
467 int flags
, const char *dev_name
, void *data
)
469 return mount_pseudo(fs_type
, "bdev:", &bdev_sops
, 0x62646576);
472 static struct file_system_type bd_type
= {
475 .kill_sb
= kill_anon_super
,
478 struct super_block
*blockdev_superblock __read_mostly
;
480 void __init
bdev_cache_init(void)
483 struct vfsmount
*bd_mnt
;
485 bdev_cachep
= kmem_cache_create("bdev_cache", sizeof(struct bdev_inode
),
486 0, (SLAB_HWCACHE_ALIGN
|SLAB_RECLAIM_ACCOUNT
|
487 SLAB_MEM_SPREAD
|SLAB_PANIC
),
489 err
= register_filesystem(&bd_type
);
491 panic("Cannot register bdev pseudo-fs");
492 bd_mnt
= kern_mount(&bd_type
);
494 panic("Cannot create bdev pseudo-fs");
496 * This vfsmount structure is only used to obtain the
497 * blockdev_superblock, so tell kmemleak not to report it.
499 kmemleak_not_leak(bd_mnt
);
500 blockdev_superblock
= bd_mnt
->mnt_sb
; /* For writeback */
504 * Most likely _very_ bad one - but then it's hardly critical for small
505 * /dev and can be fixed when somebody will need really large one.
506 * Keep in mind that it will be fed through icache hash function too.
508 static inline unsigned long hash(dev_t dev
)
510 return MAJOR(dev
)+MINOR(dev
);
513 static int bdev_test(struct inode
*inode
, void *data
)
515 return BDEV_I(inode
)->bdev
.bd_dev
== *(dev_t
*)data
;
518 static int bdev_set(struct inode
*inode
, void *data
)
520 BDEV_I(inode
)->bdev
.bd_dev
= *(dev_t
*)data
;
524 static LIST_HEAD(all_bdevs
);
526 struct block_device
*bdget(dev_t dev
)
528 struct block_device
*bdev
;
531 inode
= iget5_locked(blockdev_superblock
, hash(dev
),
532 bdev_test
, bdev_set
, &dev
);
537 bdev
= &BDEV_I(inode
)->bdev
;
539 if (inode
->i_state
& I_NEW
) {
540 bdev
->bd_contains
= NULL
;
541 bdev
->bd_inode
= inode
;
542 bdev
->bd_block_size
= (1 << inode
->i_blkbits
);
543 bdev
->bd_part_count
= 0;
544 bdev
->bd_invalidated
= 0;
545 inode
->i_mode
= S_IFBLK
;
547 inode
->i_bdev
= bdev
;
548 inode
->i_data
.a_ops
= &def_blk_aops
;
549 mapping_set_gfp_mask(&inode
->i_data
, GFP_USER
);
550 inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
551 spin_lock(&bdev_lock
);
552 list_add(&bdev
->bd_list
, &all_bdevs
);
553 spin_unlock(&bdev_lock
);
554 unlock_new_inode(inode
);
559 EXPORT_SYMBOL(bdget
);
562 * bdgrab -- Grab a reference to an already referenced block device
563 * @bdev: Block device to grab a reference to.
565 struct block_device
*bdgrab(struct block_device
*bdev
)
567 ihold(bdev
->bd_inode
);
571 long nr_blockdev_pages(void)
573 struct block_device
*bdev
;
575 spin_lock(&bdev_lock
);
576 list_for_each_entry(bdev
, &all_bdevs
, bd_list
) {
577 ret
+= bdev
->bd_inode
->i_mapping
->nrpages
;
579 spin_unlock(&bdev_lock
);
583 void bdput(struct block_device
*bdev
)
585 iput(bdev
->bd_inode
);
588 EXPORT_SYMBOL(bdput
);
590 static struct block_device
*bd_acquire(struct inode
*inode
)
592 struct block_device
*bdev
;
594 spin_lock(&bdev_lock
);
595 bdev
= inode
->i_bdev
;
597 ihold(bdev
->bd_inode
);
598 spin_unlock(&bdev_lock
);
601 spin_unlock(&bdev_lock
);
603 bdev
= bdget(inode
->i_rdev
);
605 spin_lock(&bdev_lock
);
606 if (!inode
->i_bdev
) {
608 * We take an additional reference to bd_inode,
609 * and it's released in clear_inode() of inode.
610 * So, we can access it via ->i_mapping always
613 ihold(bdev
->bd_inode
);
614 inode
->i_bdev
= bdev
;
615 inode
->i_mapping
= bdev
->bd_inode
->i_mapping
;
616 list_add(&inode
->i_devices
, &bdev
->bd_inodes
);
618 spin_unlock(&bdev_lock
);
623 /* Call when you free inode */
625 void bd_forget(struct inode
*inode
)
627 struct block_device
*bdev
= NULL
;
629 spin_lock(&bdev_lock
);
631 if (!sb_is_blkdev_sb(inode
->i_sb
))
632 bdev
= inode
->i_bdev
;
635 spin_unlock(&bdev_lock
);
638 iput(bdev
->bd_inode
);
642 * bd_may_claim - test whether a block device can be claimed
643 * @bdev: block device of interest
644 * @whole: whole block device containing @bdev, may equal @bdev
645 * @holder: holder trying to claim @bdev
647 * Test whther @bdev can be claimed by @holder.
650 * spin_lock(&bdev_lock).
653 * %true if @bdev can be claimed, %false otherwise.
655 static bool bd_may_claim(struct block_device
*bdev
, struct block_device
*whole
,
658 if (bdev
->bd_holder
== holder
)
659 return true; /* already a holder */
660 else if (bdev
->bd_holder
!= NULL
)
661 return false; /* held by someone else */
662 else if (bdev
->bd_contains
== bdev
)
663 return true; /* is a whole device which isn't held */
665 else if (whole
->bd_holder
== bd_claim
)
666 return true; /* is a partition of a device that is being partitioned */
667 else if (whole
->bd_holder
!= NULL
)
668 return false; /* is a partition of a held device */
670 return true; /* is a partition of an un-held device */
674 * bd_prepare_to_claim - prepare to claim a block device
675 * @bdev: block device of interest
676 * @whole: the whole device containing @bdev, may equal @bdev
677 * @holder: holder trying to claim @bdev
679 * Prepare to claim @bdev. This function fails if @bdev is already
680 * claimed by another holder and waits if another claiming is in
681 * progress. This function doesn't actually claim. On successful
682 * return, the caller has ownership of bd_claiming and bd_holder[s].
685 * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab
689 * 0 if @bdev can be claimed, -EBUSY otherwise.
691 static int bd_prepare_to_claim(struct block_device
*bdev
,
692 struct block_device
*whole
, void *holder
)
695 /* if someone else claimed, fail */
696 if (!bd_may_claim(bdev
, whole
, holder
))
699 /* if claiming is already in progress, wait for it to finish */
700 if (whole
->bd_claiming
) {
701 wait_queue_head_t
*wq
= bit_waitqueue(&whole
->bd_claiming
, 0);
704 prepare_to_wait(wq
, &wait
, TASK_UNINTERRUPTIBLE
);
705 spin_unlock(&bdev_lock
);
707 finish_wait(wq
, &wait
);
708 spin_lock(&bdev_lock
);
717 * bd_start_claiming - start claiming a block device
718 * @bdev: block device of interest
719 * @holder: holder trying to claim @bdev
721 * @bdev is about to be opened exclusively. Check @bdev can be opened
722 * exclusively and mark that an exclusive open is in progress. Each
723 * successful call to this function must be matched with a call to
724 * either bd_finish_claiming() or bd_abort_claiming() (which do not
727 * This function is used to gain exclusive access to the block device
728 * without actually causing other exclusive open attempts to fail. It
729 * should be used when the open sequence itself requires exclusive
730 * access but may subsequently fail.
736 * Pointer to the block device containing @bdev on success, ERR_PTR()
739 static struct block_device
*bd_start_claiming(struct block_device
*bdev
,
742 struct gendisk
*disk
;
743 struct block_device
*whole
;
749 * @bdev might not have been initialized properly yet, look up
750 * and grab the outer block device the hard way.
752 disk
= get_gendisk(bdev
->bd_dev
, &partno
);
754 return ERR_PTR(-ENXIO
);
756 whole
= bdget_disk(disk
, 0);
757 module_put(disk
->fops
->owner
);
760 return ERR_PTR(-ENOMEM
);
762 /* prepare to claim, if successful, mark claiming in progress */
763 spin_lock(&bdev_lock
);
765 err
= bd_prepare_to_claim(bdev
, whole
, holder
);
767 whole
->bd_claiming
= holder
;
768 spin_unlock(&bdev_lock
);
771 spin_unlock(&bdev_lock
);
777 /* releases bdev_lock */
778 static void __bd_abort_claiming(struct block_device
*whole
, void *holder
)
780 BUG_ON(whole
->bd_claiming
!= holder
);
781 whole
->bd_claiming
= NULL
;
782 wake_up_bit(&whole
->bd_claiming
, 0);
784 spin_unlock(&bdev_lock
);
789 * bd_abort_claiming - abort claiming a block device
790 * @whole: whole block device returned by bd_start_claiming()
791 * @holder: holder trying to claim @bdev
793 * Abort a claiming block started by bd_start_claiming(). Note that
794 * @whole is not the block device to be claimed but the whole device
795 * returned by bd_start_claiming().
798 * Grabs and releases bdev_lock.
800 static void bd_abort_claiming(struct block_device
*whole
, void *holder
)
802 spin_lock(&bdev_lock
);
803 __bd_abort_claiming(whole
, holder
); /* releases bdev_lock */
806 /* increment holders when we have a legitimate claim. requires bdev_lock */
807 static void __bd_claim(struct block_device
*bdev
, struct block_device
*whole
,
810 /* note that for a whole device bd_holders
811 * will be incremented twice, and bd_holder will
812 * be set to bd_claim before being set to holder
815 whole
->bd_holder
= bd_claim
;
817 bdev
->bd_holder
= holder
;
821 * bd_finish_claiming - finish claiming a block device
822 * @bdev: block device of interest (passed to bd_start_claiming())
823 * @whole: whole block device returned by bd_start_claiming()
824 * @holder: holder trying to claim @bdev
826 * Finish a claiming block started by bd_start_claiming().
829 * Grabs and releases bdev_lock.
831 static void bd_finish_claiming(struct block_device
*bdev
,
832 struct block_device
*whole
, void *holder
)
834 spin_lock(&bdev_lock
);
835 BUG_ON(!bd_may_claim(bdev
, whole
, holder
));
836 __bd_claim(bdev
, whole
, holder
);
837 __bd_abort_claiming(whole
, holder
); /* not actually an abort */
841 * bd_claim - claim a block device
842 * @bdev: block device to claim
843 * @holder: holder trying to claim @bdev
845 * Try to claim @bdev which must have been opened successfully.
851 * 0 if successful, -EBUSY if @bdev is already claimed.
853 int bd_claim(struct block_device
*bdev
, void *holder
)
855 struct block_device
*whole
= bdev
->bd_contains
;
860 spin_lock(&bdev_lock
);
861 res
= bd_prepare_to_claim(bdev
, whole
, holder
);
863 __bd_claim(bdev
, whole
, holder
);
864 spin_unlock(&bdev_lock
);
868 EXPORT_SYMBOL(bd_claim
);
870 void bd_release(struct block_device
*bdev
)
872 spin_lock(&bdev_lock
);
873 if (!--bdev
->bd_contains
->bd_holders
)
874 bdev
->bd_contains
->bd_holder
= NULL
;
875 if (!--bdev
->bd_holders
)
876 bdev
->bd_holder
= NULL
;
877 spin_unlock(&bdev_lock
);
880 EXPORT_SYMBOL(bd_release
);
884 * Functions for bd_claim_by_kobject / bd_release_from_kobject
886 * If a kobject is passed to bd_claim_by_kobject()
887 * and the kobject has a parent directory,
888 * following symlinks are created:
889 * o from the kobject to the claimed bdev
890 * o from "holders" directory of the bdev to the parent of the kobject
891 * bd_release_from_kobject() removes these symlinks.
894 * If /dev/dm-0 maps to /dev/sda, kobject corresponding to
895 * /sys/block/dm-0/slaves is passed to bd_claim_by_kobject(), then:
896 * /sys/block/dm-0/slaves/sda --> /sys/block/sda
897 * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
900 static int add_symlink(struct kobject
*from
, struct kobject
*to
)
904 return sysfs_create_link(from
, to
, kobject_name(to
));
907 static void del_symlink(struct kobject
*from
, struct kobject
*to
)
911 sysfs_remove_link(from
, kobject_name(to
));
915 * 'struct bd_holder' contains pointers to kobjects symlinked by
916 * bd_claim_by_kobject.
917 * It's connected to bd_holder_list which is protected by bdev->bd_sem.
920 struct list_head list
; /* chain of holders of the bdev */
921 int count
; /* references from the holder */
922 struct kobject
*sdir
; /* holder object, e.g. "/block/dm-0/slaves" */
923 struct kobject
*hdev
; /* e.g. "/block/dm-0" */
924 struct kobject
*hdir
; /* e.g. "/block/sda/holders" */
925 struct kobject
*sdev
; /* e.g. "/block/sda" */
929 * Get references of related kobjects at once.
930 * Returns 1 on success. 0 on failure.
932 * Should call bd_holder_release_dirs() after successful use.
934 static int bd_holder_grab_dirs(struct block_device
*bdev
,
935 struct bd_holder
*bo
)
940 bo
->sdir
= kobject_get(bo
->sdir
);
944 bo
->hdev
= kobject_get(bo
->sdir
->parent
);
948 bo
->sdev
= kobject_get(&part_to_dev(bdev
->bd_part
)->kobj
);
952 bo
->hdir
= kobject_get(bdev
->bd_part
->holder_dir
);
959 kobject_put(bo
->sdev
);
961 kobject_put(bo
->hdev
);
963 kobject_put(bo
->sdir
);
968 /* Put references of related kobjects at once. */
969 static void bd_holder_release_dirs(struct bd_holder
*bo
)
971 kobject_put(bo
->hdir
);
972 kobject_put(bo
->sdev
);
973 kobject_put(bo
->hdev
);
974 kobject_put(bo
->sdir
);
977 static struct bd_holder
*alloc_bd_holder(struct kobject
*kobj
)
979 struct bd_holder
*bo
;
981 bo
= kzalloc(sizeof(*bo
), GFP_KERNEL
);
991 static void free_bd_holder(struct bd_holder
*bo
)
997 * find_bd_holder - find matching struct bd_holder from the block device
999 * @bdev: struct block device to be searched
1000 * @bo: target struct bd_holder
1002 * Returns matching entry with @bo in @bdev->bd_holder_list.
1003 * If found, increment the reference count and return the pointer.
1004 * If not found, returns NULL.
1006 static struct bd_holder
*find_bd_holder(struct block_device
*bdev
,
1007 struct bd_holder
*bo
)
1009 struct bd_holder
*tmp
;
1011 list_for_each_entry(tmp
, &bdev
->bd_holder_list
, list
)
1012 if (tmp
->sdir
== bo
->sdir
) {
1021 * add_bd_holder - create sysfs symlinks for bd_claim() relationship
1023 * @bdev: block device to be bd_claimed
1024 * @bo: preallocated and initialized by alloc_bd_holder()
1026 * Add @bo to @bdev->bd_holder_list, create symlinks.
1028 * Returns 0 if symlinks are created.
1029 * Returns -ve if something fails.
1031 static int add_bd_holder(struct block_device
*bdev
, struct bd_holder
*bo
)
1038 if (!bd_holder_grab_dirs(bdev
, bo
))
1041 err
= add_symlink(bo
->sdir
, bo
->sdev
);
1045 err
= add_symlink(bo
->hdir
, bo
->hdev
);
1047 del_symlink(bo
->sdir
, bo
->sdev
);
1051 list_add_tail(&bo
->list
, &bdev
->bd_holder_list
);
1056 * del_bd_holder - delete sysfs symlinks for bd_claim() relationship
1058 * @bdev: block device to be bd_claimed
1059 * @kobj: holder's kobject
1061 * If there is matching entry with @kobj in @bdev->bd_holder_list
1062 * and no other bd_claim() from the same kobject,
1063 * remove the struct bd_holder from the list, delete symlinks for it.
1065 * Returns a pointer to the struct bd_holder when it's removed from the list
1066 * and ready to be freed.
1067 * Returns NULL if matching claim isn't found or there is other bd_claim()
1068 * by the same kobject.
1070 static struct bd_holder
*del_bd_holder(struct block_device
*bdev
,
1071 struct kobject
*kobj
)
1073 struct bd_holder
*bo
;
1075 list_for_each_entry(bo
, &bdev
->bd_holder_list
, list
) {
1076 if (bo
->sdir
== kobj
) {
1078 BUG_ON(bo
->count
< 0);
1080 list_del(&bo
->list
);
1081 del_symlink(bo
->sdir
, bo
->sdev
);
1082 del_symlink(bo
->hdir
, bo
->hdev
);
1083 bd_holder_release_dirs(bo
);
1094 * bd_claim_by_kobject - bd_claim() with additional kobject signature
1096 * @bdev: block device to be claimed
1097 * @holder: holder's signature
1098 * @kobj: holder's kobject
1100 * Do bd_claim() and if it succeeds, create sysfs symlinks between
1101 * the bdev and the holder's kobject.
1102 * Use bd_release_from_kobject() when relesing the claimed bdev.
1104 * Returns 0 on success. (same as bd_claim())
1105 * Returns errno on failure.
1107 static int bd_claim_by_kobject(struct block_device
*bdev
, void *holder
,
1108 struct kobject
*kobj
)
1111 struct bd_holder
*bo
, *found
;
1116 bo
= alloc_bd_holder(kobj
);
1120 mutex_lock(&bdev
->bd_mutex
);
1122 err
= bd_claim(bdev
, holder
);
1126 found
= find_bd_holder(bdev
, bo
);
1130 err
= add_bd_holder(bdev
, bo
);
1136 mutex_unlock(&bdev
->bd_mutex
);
1142 * bd_release_from_kobject - bd_release() with additional kobject signature
1144 * @bdev: block device to be released
1145 * @kobj: holder's kobject
1147 * Do bd_release() and remove sysfs symlinks created by bd_claim_by_kobject().
1149 static void bd_release_from_kobject(struct block_device
*bdev
,
1150 struct kobject
*kobj
)
1155 mutex_lock(&bdev
->bd_mutex
);
1157 free_bd_holder(del_bd_holder(bdev
, kobj
));
1158 mutex_unlock(&bdev
->bd_mutex
);
1162 * bd_claim_by_disk - wrapper function for bd_claim_by_kobject()
1164 * @bdev: block device to be claimed
1165 * @holder: holder's signature
1166 * @disk: holder's gendisk
1168 * Call bd_claim_by_kobject() with getting @disk->slave_dir.
1170 int bd_claim_by_disk(struct block_device
*bdev
, void *holder
,
1171 struct gendisk
*disk
)
1173 return bd_claim_by_kobject(bdev
, holder
, kobject_get(disk
->slave_dir
));
1175 EXPORT_SYMBOL_GPL(bd_claim_by_disk
);
1178 * bd_release_from_disk - wrapper function for bd_release_from_kobject()
1180 * @bdev: block device to be claimed
1181 * @disk: holder's gendisk
1183 * Call bd_release_from_kobject() and put @disk->slave_dir.
1185 void bd_release_from_disk(struct block_device
*bdev
, struct gendisk
*disk
)
1187 bd_release_from_kobject(bdev
, disk
->slave_dir
);
1188 kobject_put(disk
->slave_dir
);
1190 EXPORT_SYMBOL_GPL(bd_release_from_disk
);
1194 * Tries to open block device by device number. Use it ONLY if you
1195 * really do not have anything better - i.e. when you are behind a
1196 * truly sucky interface and all you are given is a device number. _Never_
1197 * to be used for internal purposes. If you ever need it - reconsider
1200 struct block_device
*open_by_devnum(dev_t dev
, fmode_t mode
)
1202 struct block_device
*bdev
= bdget(dev
);
1205 err
= blkdev_get(bdev
, mode
);
1206 return err
? ERR_PTR(err
) : bdev
;
1209 EXPORT_SYMBOL(open_by_devnum
);
1212 * flush_disk - invalidates all buffer-cache entries on a disk
1214 * @bdev: struct block device to be flushed
1216 * Invalidates all buffer-cache entries on a disk. It should be called
1217 * when a disk has been changed -- either by a media change or online
1220 static void flush_disk(struct block_device
*bdev
, bool kill_dirty
)
1222 if (__invalidate_device(bdev
, kill_dirty
)) {
1223 char name
[BDEVNAME_SIZE
] = "";
1226 disk_name(bdev
->bd_disk
, 0, name
);
1227 printk(KERN_WARNING
"VFS: busy inodes on changed media or "
1228 "resized disk %s\n", name
);
1233 if (disk_partitionable(bdev
->bd_disk
))
1234 bdev
->bd_invalidated
= 1;
1238 * check_disk_size_change - checks for disk size change and adjusts bdev size.
1239 * @disk: struct gendisk to check
1240 * @bdev: struct bdev to adjust.
1242 * This routine checks to see if the bdev size does not match the disk size
1243 * and adjusts it if it differs.
1245 void check_disk_size_change(struct gendisk
*disk
, struct block_device
*bdev
)
1247 loff_t disk_size
, bdev_size
;
1249 disk_size
= (loff_t
)get_capacity(disk
) << 9;
1250 bdev_size
= i_size_read(bdev
->bd_inode
);
1251 if (disk_size
!= bdev_size
) {
1252 char name
[BDEVNAME_SIZE
];
1254 disk_name(disk
, 0, name
);
1256 "%s: detected capacity change from %lld to %lld\n",
1257 name
, bdev_size
, disk_size
);
1258 i_size_write(bdev
->bd_inode
, disk_size
);
1259 flush_disk(bdev
, false);
1262 EXPORT_SYMBOL(check_disk_size_change
);
1265 * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back
1266 * @disk: struct gendisk to be revalidated
1268 * This routine is a wrapper for lower-level driver's revalidate_disk
1269 * call-backs. It is used to do common pre and post operations needed
1270 * for all revalidate_disk operations.
1272 int revalidate_disk(struct gendisk
*disk
)
1274 struct block_device
*bdev
;
1277 if (disk
->fops
->revalidate_disk
)
1278 ret
= disk
->fops
->revalidate_disk(disk
);
1280 bdev
= bdget_disk(disk
, 0);
1284 mutex_lock(&bdev
->bd_mutex
);
1285 check_disk_size_change(disk
, bdev
);
1286 mutex_unlock(&bdev
->bd_mutex
);
1290 EXPORT_SYMBOL(revalidate_disk
);
1293 * This routine checks whether a removable media has been changed,
1294 * and invalidates all buffer-cache-entries in that case. This
1295 * is a relatively slow routine, so we have to try to minimize using
1296 * it. Thus it is called only upon a 'mount' or 'open'. This
1297 * is the best way of combining speed and utility, I think.
1298 * People changing diskettes in the middle of an operation deserve
1301 int check_disk_change(struct block_device
*bdev
)
1303 struct gendisk
*disk
= bdev
->bd_disk
;
1304 const struct block_device_operations
*bdops
= disk
->fops
;
1306 if (!bdops
->media_changed
)
1308 if (!bdops
->media_changed(bdev
->bd_disk
))
1311 flush_disk(bdev
, true);
1312 if (bdops
->revalidate_disk
)
1313 bdops
->revalidate_disk(bdev
->bd_disk
);
1317 EXPORT_SYMBOL(check_disk_change
);
1319 void bd_set_size(struct block_device
*bdev
, loff_t size
)
1321 unsigned bsize
= bdev_logical_block_size(bdev
);
1323 bdev
->bd_inode
->i_size
= size
;
1324 while (bsize
< PAGE_CACHE_SIZE
) {
1329 bdev
->bd_block_size
= bsize
;
1330 bdev
->bd_inode
->i_blkbits
= blksize_bits(bsize
);
1332 EXPORT_SYMBOL(bd_set_size
);
1334 static int __blkdev_put(struct block_device
*bdev
, fmode_t mode
, int for_part
);
1339 * mutex_lock(part->bd_mutex)
1340 * mutex_lock_nested(whole->bd_mutex, 1)
1343 static int __blkdev_get(struct block_device
*bdev
, fmode_t mode
, int for_part
)
1345 struct gendisk
*disk
;
1350 if (mode
& FMODE_READ
)
1352 if (mode
& FMODE_WRITE
)
1355 * hooks: /n/, see "layering violations".
1358 ret
= devcgroup_inode_permission(bdev
->bd_inode
, perm
);
1368 disk
= get_gendisk(bdev
->bd_dev
, &partno
);
1372 mutex_lock_nested(&bdev
->bd_mutex
, for_part
);
1373 if (!bdev
->bd_openers
) {
1374 bdev
->bd_disk
= disk
;
1375 bdev
->bd_contains
= bdev
;
1377 struct backing_dev_info
*bdi
;
1380 bdev
->bd_part
= disk_get_part(disk
, partno
);
1384 if (disk
->fops
->open
) {
1385 ret
= disk
->fops
->open(bdev
, mode
);
1386 if (ret
== -ERESTARTSYS
) {
1387 /* Lost a race with 'disk' being
1388 * deleted, try again.
1391 disk_put_part(bdev
->bd_part
);
1392 bdev
->bd_part
= NULL
;
1393 module_put(disk
->fops
->owner
);
1395 bdev
->bd_disk
= NULL
;
1396 mutex_unlock(&bdev
->bd_mutex
);
1402 if (!bdev
->bd_openers
) {
1403 bd_set_size(bdev
,(loff_t
)get_capacity(disk
)<<9);
1404 bdi
= blk_get_backing_dev_info(bdev
);
1406 bdi
= &default_backing_dev_info
;
1407 bdev_inode_switch_bdi(bdev
->bd_inode
, bdi
);
1409 if (bdev
->bd_invalidated
)
1410 rescan_partitions(disk
, bdev
);
1412 struct block_device
*whole
;
1413 whole
= bdget_disk(disk
, 0);
1418 ret
= __blkdev_get(whole
, mode
, 1);
1421 bdev
->bd_contains
= whole
;
1422 bdev_inode_switch_bdi(bdev
->bd_inode
,
1423 whole
->bd_inode
->i_data
.backing_dev_info
);
1424 bdev
->bd_part
= disk_get_part(disk
, partno
);
1425 if (!(disk
->flags
& GENHD_FL_UP
) ||
1426 !bdev
->bd_part
|| !bdev
->bd_part
->nr_sects
) {
1430 bd_set_size(bdev
, (loff_t
)bdev
->bd_part
->nr_sects
<< 9);
1433 module_put(disk
->fops
->owner
);
1436 if (bdev
->bd_contains
== bdev
) {
1437 if (bdev
->bd_disk
->fops
->open
) {
1438 ret
= bdev
->bd_disk
->fops
->open(bdev
, mode
);
1440 goto out_unlock_bdev
;
1442 if (bdev
->bd_invalidated
)
1443 rescan_partitions(bdev
->bd_disk
, bdev
);
1448 bdev
->bd_part_count
++;
1449 mutex_unlock(&bdev
->bd_mutex
);
1453 disk_put_part(bdev
->bd_part
);
1454 bdev
->bd_disk
= NULL
;
1455 bdev
->bd_part
= NULL
;
1456 bdev_inode_switch_bdi(bdev
->bd_inode
, &default_backing_dev_info
);
1457 if (bdev
!= bdev
->bd_contains
)
1458 __blkdev_put(bdev
->bd_contains
, mode
, 1);
1459 bdev
->bd_contains
= NULL
;
1461 mutex_unlock(&bdev
->bd_mutex
);
1464 module_put(disk
->fops
->owner
);
1471 int blkdev_get(struct block_device
*bdev
, fmode_t mode
)
1473 return __blkdev_get(bdev
, mode
, 0);
1475 EXPORT_SYMBOL(blkdev_get
);
1477 static int blkdev_open(struct inode
* inode
, struct file
* filp
)
1479 struct block_device
*whole
= NULL
;
1480 struct block_device
*bdev
;
1484 * Preserve backwards compatibility and allow large file access
1485 * even if userspace doesn't ask for it explicitly. Some mkfs
1486 * binary needs it. We might want to drop this workaround
1487 * during an unstable branch.
1489 filp
->f_flags
|= O_LARGEFILE
;
1491 if (filp
->f_flags
& O_NDELAY
)
1492 filp
->f_mode
|= FMODE_NDELAY
;
1493 if (filp
->f_flags
& O_EXCL
)
1494 filp
->f_mode
|= FMODE_EXCL
;
1495 if ((filp
->f_flags
& O_ACCMODE
) == 3)
1496 filp
->f_mode
|= FMODE_WRITE_IOCTL
;
1498 bdev
= bd_acquire(inode
);
1502 if (filp
->f_mode
& FMODE_EXCL
) {
1503 whole
= bd_start_claiming(bdev
, filp
);
1504 if (IS_ERR(whole
)) {
1506 return PTR_ERR(whole
);
1510 filp
->f_mapping
= bdev
->bd_inode
->i_mapping
;
1512 res
= blkdev_get(bdev
, filp
->f_mode
);
1516 bd_finish_claiming(bdev
, whole
, filp
);
1518 bd_abort_claiming(whole
, filp
);
1524 static int __blkdev_put(struct block_device
*bdev
, fmode_t mode
, int for_part
)
1527 struct gendisk
*disk
= bdev
->bd_disk
;
1528 struct block_device
*victim
= NULL
;
1530 mutex_lock_nested(&bdev
->bd_mutex
, for_part
);
1532 bdev
->bd_part_count
--;
1534 if (!--bdev
->bd_openers
) {
1535 sync_blockdev(bdev
);
1538 if (bdev
->bd_contains
== bdev
) {
1539 if (disk
->fops
->release
)
1540 ret
= disk
->fops
->release(disk
, mode
);
1542 if (!bdev
->bd_openers
) {
1543 struct module
*owner
= disk
->fops
->owner
;
1547 disk_put_part(bdev
->bd_part
);
1548 bdev
->bd_part
= NULL
;
1549 bdev
->bd_disk
= NULL
;
1550 bdev_inode_switch_bdi(bdev
->bd_inode
,
1551 &default_backing_dev_info
);
1552 if (bdev
!= bdev
->bd_contains
)
1553 victim
= bdev
->bd_contains
;
1554 bdev
->bd_contains
= NULL
;
1556 mutex_unlock(&bdev
->bd_mutex
);
1559 __blkdev_put(victim
, mode
, 1);
1563 int blkdev_put(struct block_device
*bdev
, fmode_t mode
)
1565 return __blkdev_put(bdev
, mode
, 0);
1567 EXPORT_SYMBOL(blkdev_put
);
1569 static int blkdev_close(struct inode
* inode
, struct file
* filp
)
1571 struct block_device
*bdev
= I_BDEV(filp
->f_mapping
->host
);
1572 if (bdev
->bd_holder
== filp
)
1574 return blkdev_put(bdev
, filp
->f_mode
);
1577 static long block_ioctl(struct file
*file
, unsigned cmd
, unsigned long arg
)
1579 struct block_device
*bdev
= I_BDEV(file
->f_mapping
->host
);
1580 fmode_t mode
= file
->f_mode
;
1583 * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
1584 * to updated it before every ioctl.
1586 if (file
->f_flags
& O_NDELAY
)
1587 mode
|= FMODE_NDELAY
;
1589 mode
&= ~FMODE_NDELAY
;
1591 return blkdev_ioctl(bdev
, mode
, cmd
, arg
);
1595 * Write data to the block device. Only intended for the block device itself
1596 * and the raw driver which basically is a fake block device.
1598 * Does not take i_mutex for the write and thus is not for general purpose
1601 ssize_t
blkdev_aio_write(struct kiocb
*iocb
, const struct iovec
*iov
,
1602 unsigned long nr_segs
, loff_t pos
)
1604 struct file
*file
= iocb
->ki_filp
;
1607 BUG_ON(iocb
->ki_pos
!= pos
);
1609 ret
= __generic_file_aio_write(iocb
, iov
, nr_segs
, &iocb
->ki_pos
);
1610 if (ret
> 0 || ret
== -EIOCBQUEUED
) {
1613 err
= generic_write_sync(file
, pos
, ret
);
1614 if (err
< 0 && ret
> 0)
1619 EXPORT_SYMBOL_GPL(blkdev_aio_write
);
1622 * Try to release a page associated with block device when the system
1623 * is under memory pressure.
1625 static int blkdev_releasepage(struct page
*page
, gfp_t wait
)
1627 struct super_block
*super
= BDEV_I(page
->mapping
->host
)->bdev
.bd_super
;
1629 if (super
&& super
->s_op
->bdev_try_to_free_page
)
1630 return super
->s_op
->bdev_try_to_free_page(super
, page
, wait
);
1632 return try_to_free_buffers(page
);
1635 static const struct address_space_operations def_blk_aops
= {
1636 .readpage
= blkdev_readpage
,
1637 .writepage
= blkdev_writepage
,
1638 .sync_page
= block_sync_page
,
1639 .write_begin
= blkdev_write_begin
,
1640 .write_end
= blkdev_write_end
,
1641 .writepages
= generic_writepages
,
1642 .releasepage
= blkdev_releasepage
,
1643 .direct_IO
= blkdev_direct_IO
,
1646 const struct file_operations def_blk_fops
= {
1647 .open
= blkdev_open
,
1648 .release
= blkdev_close
,
1649 .llseek
= block_llseek
,
1650 .read
= do_sync_read
,
1651 .write
= do_sync_write
,
1652 .aio_read
= generic_file_aio_read
,
1653 .aio_write
= blkdev_aio_write
,
1654 .mmap
= generic_file_mmap
,
1655 .fsync
= blkdev_fsync
,
1656 .unlocked_ioctl
= block_ioctl
,
1657 #ifdef CONFIG_COMPAT
1658 .compat_ioctl
= compat_blkdev_ioctl
,
1660 .splice_read
= generic_file_splice_read
,
1661 .splice_write
= generic_file_splice_write
,
1664 int ioctl_by_bdev(struct block_device
*bdev
, unsigned cmd
, unsigned long arg
)
1667 mm_segment_t old_fs
= get_fs();
1669 res
= blkdev_ioctl(bdev
, 0, cmd
, arg
);
1674 EXPORT_SYMBOL(ioctl_by_bdev
);
1677 * lookup_bdev - lookup a struct block_device by name
1678 * @pathname: special file representing the block device
1680 * Get a reference to the blockdevice at @pathname in the current
1681 * namespace if possible and return it. Return ERR_PTR(error)
1684 struct block_device
*lookup_bdev(const char *pathname
)
1686 struct block_device
*bdev
;
1687 struct inode
*inode
;
1691 if (!pathname
|| !*pathname
)
1692 return ERR_PTR(-EINVAL
);
1694 error
= kern_path(pathname
, LOOKUP_FOLLOW
, &path
);
1696 return ERR_PTR(error
);
1698 inode
= path
.dentry
->d_inode
;
1700 if (!S_ISBLK(inode
->i_mode
))
1703 if (path
.mnt
->mnt_flags
& MNT_NODEV
)
1706 bdev
= bd_acquire(inode
);
1713 bdev
= ERR_PTR(error
);
1716 EXPORT_SYMBOL(lookup_bdev
);
1719 * open_bdev_exclusive - open a block device by name and set it up for use
1721 * @path: special file representing the block device
1722 * @mode: FMODE_... combination to pass be used
1723 * @holder: owner for exclusion
1725 * Open the blockdevice described by the special file at @path, claim it
1728 struct block_device
*open_bdev_exclusive(const char *path
, fmode_t mode
, void *holder
)
1730 struct block_device
*bdev
, *whole
;
1733 bdev
= lookup_bdev(path
);
1737 whole
= bd_start_claiming(bdev
, holder
);
1738 if (IS_ERR(whole
)) {
1743 error
= blkdev_get(bdev
, mode
);
1745 goto out_abort_claiming
;
1748 if ((mode
& FMODE_WRITE
) && bdev_read_only(bdev
))
1749 goto out_blkdev_put
;
1751 bd_finish_claiming(bdev
, whole
, holder
);
1755 blkdev_put(bdev
, mode
);
1757 bd_abort_claiming(whole
, holder
);
1758 return ERR_PTR(error
);
1761 EXPORT_SYMBOL(open_bdev_exclusive
);
1764 * close_bdev_exclusive - close a blockdevice opened by open_bdev_exclusive()
1766 * @bdev: blockdevice to close
1767 * @mode: mode, must match that used to open.
1769 * This is the counterpart to open_bdev_exclusive().
1771 void close_bdev_exclusive(struct block_device
*bdev
, fmode_t mode
)
1774 blkdev_put(bdev
, mode
);
1777 EXPORT_SYMBOL(close_bdev_exclusive
);
1779 int __invalidate_device(struct block_device
*bdev
, bool kill_dirty
)
1781 struct super_block
*sb
= get_super(bdev
);
1786 * no need to lock the super, get_super holds the
1787 * read mutex so the filesystem cannot go away
1788 * under us (->put_super runs with the write lock
1791 shrink_dcache_sb(sb
);
1792 res
= invalidate_inodes(sb
, kill_dirty
);
1795 invalidate_bdev(bdev
);
1798 EXPORT_SYMBOL(__invalidate_device
);