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/swap.h>
21 #include <linux/pagevec.h>
22 #include <linux/writeback.h>
23 #include <linux/mpage.h>
24 #include <linux/mount.h>
25 #include <linux/uio.h>
26 #include <linux/namei.h>
27 #include <linux/log2.h>
28 #include <linux/kmemleak.h>
29 #include <linux/cleancache.h>
30 #include <asm/uaccess.h>
34 struct block_device bdev
;
35 struct inode vfs_inode
;
38 static const struct address_space_operations def_blk_aops
;
40 static inline struct bdev_inode
*BDEV_I(struct inode
*inode
)
42 return container_of(inode
, struct bdev_inode
, vfs_inode
);
45 inline struct block_device
*I_BDEV(struct inode
*inode
)
47 return &BDEV_I(inode
)->bdev
;
49 EXPORT_SYMBOL(I_BDEV
);
52 * Move the inode from its current bdi to a new bdi. If the inode is dirty we
53 * need to move it onto the dirty list of @dst so that the inode is always on
56 static void bdev_inode_switch_bdi(struct inode
*inode
,
57 struct backing_dev_info
*dst
)
59 struct backing_dev_info
*old
= inode
->i_data
.backing_dev_info
;
61 if (unlikely(dst
== old
)) /* deadlock avoidance */
63 bdi_lock_two(&old
->wb
, &dst
->wb
);
64 spin_lock(&inode
->i_lock
);
65 inode
->i_data
.backing_dev_info
= dst
;
66 if (inode
->i_state
& I_DIRTY
)
67 list_move(&inode
->i_wb_list
, &dst
->wb
.b_dirty
);
68 spin_unlock(&inode
->i_lock
);
69 spin_unlock(&old
->wb
.list_lock
);
70 spin_unlock(&dst
->wb
.list_lock
);
73 static sector_t
max_block(struct block_device
*bdev
)
75 sector_t retval
= ~((sector_t
)0);
76 loff_t sz
= i_size_read(bdev
->bd_inode
);
79 unsigned int size
= block_size(bdev
);
80 unsigned int sizebits
= blksize_bits(size
);
81 retval
= (sz
>> sizebits
);
86 /* Kill _all_ buffers and pagecache , dirty or not.. */
87 void kill_bdev(struct block_device
*bdev
)
89 struct address_space
*mapping
= bdev
->bd_inode
->i_mapping
;
91 if (mapping
->nrpages
== 0)
95 truncate_inode_pages(mapping
, 0);
97 EXPORT_SYMBOL(kill_bdev
);
99 /* Invalidate clean unused buffers and pagecache. */
100 void invalidate_bdev(struct block_device
*bdev
)
102 struct address_space
*mapping
= bdev
->bd_inode
->i_mapping
;
104 if (mapping
->nrpages
== 0)
107 invalidate_bh_lrus();
108 lru_add_drain_all(); /* make sure all lru add caches are flushed */
109 invalidate_mapping_pages(mapping
, 0, -1);
110 /* 99% of the time, we don't need to flush the cleancache on the bdev.
111 * But, for the strange corners, lets be cautious
113 cleancache_flush_inode(mapping
);
115 EXPORT_SYMBOL(invalidate_bdev
);
117 int set_blocksize(struct block_device
*bdev
, int size
)
119 /* Size must be a power of two, and between 512 and PAGE_SIZE */
120 if (size
> PAGE_SIZE
|| size
< 512 || !is_power_of_2(size
))
123 /* Size cannot be smaller than the size supported by the device */
124 if (size
< bdev_logical_block_size(bdev
))
127 /* Don't change the size if it is same as current */
128 if (bdev
->bd_block_size
!= size
) {
130 bdev
->bd_block_size
= size
;
131 bdev
->bd_inode
->i_blkbits
= blksize_bits(size
);
137 EXPORT_SYMBOL(set_blocksize
);
139 int sb_set_blocksize(struct super_block
*sb
, int size
)
141 if (set_blocksize(sb
->s_bdev
, size
))
143 /* If we get here, we know size is power of two
144 * and it's value is between 512 and PAGE_SIZE */
145 sb
->s_blocksize
= size
;
146 sb
->s_blocksize_bits
= blksize_bits(size
);
147 return sb
->s_blocksize
;
150 EXPORT_SYMBOL(sb_set_blocksize
);
152 int sb_min_blocksize(struct super_block
*sb
, int size
)
154 int minsize
= bdev_logical_block_size(sb
->s_bdev
);
157 return sb_set_blocksize(sb
, size
);
160 EXPORT_SYMBOL(sb_min_blocksize
);
163 blkdev_get_block(struct inode
*inode
, sector_t iblock
,
164 struct buffer_head
*bh
, int create
)
166 if (iblock
>= max_block(I_BDEV(inode
))) {
171 * for reads, we're just trying to fill a partial page.
172 * return a hole, they will have to call get_block again
173 * before they can fill it, and they will get -EIO at that
178 bh
->b_bdev
= I_BDEV(inode
);
179 bh
->b_blocknr
= iblock
;
180 set_buffer_mapped(bh
);
185 blkdev_get_blocks(struct inode
*inode
, sector_t iblock
,
186 struct buffer_head
*bh
, int create
)
188 sector_t end_block
= max_block(I_BDEV(inode
));
189 unsigned long max_blocks
= bh
->b_size
>> inode
->i_blkbits
;
191 if ((iblock
+ max_blocks
) > end_block
) {
192 max_blocks
= end_block
- iblock
;
193 if ((long)max_blocks
<= 0) {
195 return -EIO
; /* write fully beyond EOF */
197 * It is a read which is fully beyond EOF. We return
198 * a !buffer_mapped buffer
204 bh
->b_bdev
= I_BDEV(inode
);
205 bh
->b_blocknr
= iblock
;
206 bh
->b_size
= max_blocks
<< inode
->i_blkbits
;
208 set_buffer_mapped(bh
);
213 blkdev_direct_IO(int rw
, struct kiocb
*iocb
, const struct iovec
*iov
,
214 loff_t offset
, unsigned long nr_segs
)
216 struct file
*file
= iocb
->ki_filp
;
217 struct inode
*inode
= file
->f_mapping
->host
;
219 return __blockdev_direct_IO(rw
, iocb
, inode
, I_BDEV(inode
), iov
, offset
,
220 nr_segs
, blkdev_get_blocks
, NULL
, NULL
, 0);
223 int __sync_blockdev(struct block_device
*bdev
, int wait
)
228 return filemap_flush(bdev
->bd_inode
->i_mapping
);
229 return filemap_write_and_wait(bdev
->bd_inode
->i_mapping
);
233 * Write out and wait upon all the dirty data associated with a block
234 * device via its mapping. Does not take the superblock lock.
236 int sync_blockdev(struct block_device
*bdev
)
238 return __sync_blockdev(bdev
, 1);
240 EXPORT_SYMBOL(sync_blockdev
);
243 * Write out and wait upon all dirty data associated with this
244 * device. Filesystem data as well as the underlying block
245 * device. Takes the superblock lock.
247 int fsync_bdev(struct block_device
*bdev
)
249 struct super_block
*sb
= get_super(bdev
);
251 int res
= sync_filesystem(sb
);
255 return sync_blockdev(bdev
);
257 EXPORT_SYMBOL(fsync_bdev
);
260 * freeze_bdev -- lock a filesystem and force it into a consistent state
261 * @bdev: blockdevice to lock
263 * If a superblock is found on this device, we take the s_umount semaphore
264 * on it to make sure nobody unmounts until the snapshot creation is done.
265 * The reference counter (bd_fsfreeze_count) guarantees that only the last
266 * unfreeze process can unfreeze the frozen filesystem actually when multiple
267 * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
268 * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
271 struct super_block
*freeze_bdev(struct block_device
*bdev
)
273 struct super_block
*sb
;
276 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
277 if (++bdev
->bd_fsfreeze_count
> 1) {
279 * We don't even need to grab a reference - the first call
280 * to freeze_bdev grab an active reference and only the last
281 * thaw_bdev drops it.
283 sb
= get_super(bdev
);
285 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
289 sb
= get_active_super(bdev
);
292 error
= freeze_super(sb
);
294 deactivate_super(sb
);
295 bdev
->bd_fsfreeze_count
--;
296 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
297 return ERR_PTR(error
);
299 deactivate_super(sb
);
302 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
303 return sb
; /* thaw_bdev releases s->s_umount */
305 EXPORT_SYMBOL(freeze_bdev
);
308 * thaw_bdev -- unlock filesystem
309 * @bdev: blockdevice to unlock
310 * @sb: associated superblock
312 * Unlocks the filesystem and marks it writeable again after freeze_bdev().
314 int thaw_bdev(struct block_device
*bdev
, struct super_block
*sb
)
318 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
319 if (!bdev
->bd_fsfreeze_count
)
323 if (--bdev
->bd_fsfreeze_count
> 0)
329 error
= thaw_super(sb
);
331 bdev
->bd_fsfreeze_count
++;
332 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
336 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
339 EXPORT_SYMBOL(thaw_bdev
);
341 static int blkdev_writepage(struct page
*page
, struct writeback_control
*wbc
)
343 return block_write_full_page(page
, blkdev_get_block
, wbc
);
346 static int blkdev_readpage(struct file
* file
, struct page
* page
)
348 return block_read_full_page(page
, blkdev_get_block
);
351 static int blkdev_write_begin(struct file
*file
, struct address_space
*mapping
,
352 loff_t pos
, unsigned len
, unsigned flags
,
353 struct page
**pagep
, void **fsdata
)
355 return block_write_begin(mapping
, pos
, len
, flags
, pagep
,
359 static int blkdev_write_end(struct file
*file
, struct address_space
*mapping
,
360 loff_t pos
, unsigned len
, unsigned copied
,
361 struct page
*page
, void *fsdata
)
364 ret
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
367 page_cache_release(page
);
374 * for a block special file file->f_path.dentry->d_inode->i_size is zero
375 * so we compute the size by hand (just as in block_read/write above)
377 static loff_t
block_llseek(struct file
*file
, loff_t offset
, int origin
)
379 struct inode
*bd_inode
= file
->f_mapping
->host
;
383 mutex_lock(&bd_inode
->i_mutex
);
384 size
= i_size_read(bd_inode
);
392 offset
+= file
->f_pos
;
398 if (offset
>= 0 && offset
<= size
) {
399 if (offset
!= file
->f_pos
) {
400 file
->f_pos
= offset
;
405 mutex_unlock(&bd_inode
->i_mutex
);
409 int blkdev_fsync(struct file
*filp
, loff_t start
, loff_t end
, int datasync
)
411 struct inode
*bd_inode
= filp
->f_mapping
->host
;
412 struct block_device
*bdev
= I_BDEV(bd_inode
);
415 error
= filemap_write_and_wait_range(filp
->f_mapping
, start
, end
);
420 * There is no need to serialise calls to blkdev_issue_flush with
421 * i_mutex and doing so causes performance issues with concurrent
422 * O_SYNC writers to a block device.
424 error
= blkdev_issue_flush(bdev
, GFP_KERNEL
, NULL
);
425 if (error
== -EOPNOTSUPP
)
430 EXPORT_SYMBOL(blkdev_fsync
);
436 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(bdev_lock
);
437 static struct kmem_cache
* bdev_cachep __read_mostly
;
439 static struct inode
*bdev_alloc_inode(struct super_block
*sb
)
441 struct bdev_inode
*ei
= kmem_cache_alloc(bdev_cachep
, GFP_KERNEL
);
444 return &ei
->vfs_inode
;
447 static void bdev_i_callback(struct rcu_head
*head
)
449 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
450 struct bdev_inode
*bdi
= BDEV_I(inode
);
452 kmem_cache_free(bdev_cachep
, bdi
);
455 static void bdev_destroy_inode(struct inode
*inode
)
457 call_rcu(&inode
->i_rcu
, bdev_i_callback
);
460 static void init_once(void *foo
)
462 struct bdev_inode
*ei
= (struct bdev_inode
*) foo
;
463 struct block_device
*bdev
= &ei
->bdev
;
465 memset(bdev
, 0, sizeof(*bdev
));
466 mutex_init(&bdev
->bd_mutex
);
467 INIT_LIST_HEAD(&bdev
->bd_inodes
);
468 INIT_LIST_HEAD(&bdev
->bd_list
);
470 INIT_LIST_HEAD(&bdev
->bd_holder_disks
);
472 inode_init_once(&ei
->vfs_inode
);
473 /* Initialize mutex for freeze. */
474 mutex_init(&bdev
->bd_fsfreeze_mutex
);
477 static inline void __bd_forget(struct inode
*inode
)
479 list_del_init(&inode
->i_devices
);
480 inode
->i_bdev
= NULL
;
481 inode
->i_mapping
= &inode
->i_data
;
484 static void bdev_evict_inode(struct inode
*inode
)
486 struct block_device
*bdev
= &BDEV_I(inode
)->bdev
;
488 truncate_inode_pages(&inode
->i_data
, 0);
489 invalidate_inode_buffers(inode
); /* is it needed here? */
490 end_writeback(inode
);
491 spin_lock(&bdev_lock
);
492 while ( (p
= bdev
->bd_inodes
.next
) != &bdev
->bd_inodes
) {
493 __bd_forget(list_entry(p
, struct inode
, i_devices
));
495 list_del_init(&bdev
->bd_list
);
496 spin_unlock(&bdev_lock
);
499 static const struct super_operations bdev_sops
= {
500 .statfs
= simple_statfs
,
501 .alloc_inode
= bdev_alloc_inode
,
502 .destroy_inode
= bdev_destroy_inode
,
503 .drop_inode
= generic_delete_inode
,
504 .evict_inode
= bdev_evict_inode
,
507 static struct dentry
*bd_mount(struct file_system_type
*fs_type
,
508 int flags
, const char *dev_name
, void *data
)
510 return mount_pseudo(fs_type
, "bdev:", &bdev_sops
, NULL
, 0x62646576);
513 static struct file_system_type bd_type
= {
516 .kill_sb
= kill_anon_super
,
519 static struct super_block
*blockdev_superblock __read_mostly
;
521 void __init
bdev_cache_init(void)
524 struct vfsmount
*bd_mnt
;
526 bdev_cachep
= kmem_cache_create("bdev_cache", sizeof(struct bdev_inode
),
527 0, (SLAB_HWCACHE_ALIGN
|SLAB_RECLAIM_ACCOUNT
|
528 SLAB_MEM_SPREAD
|SLAB_PANIC
),
530 err
= register_filesystem(&bd_type
);
532 panic("Cannot register bdev pseudo-fs");
533 bd_mnt
= kern_mount(&bd_type
);
535 panic("Cannot create bdev pseudo-fs");
537 * This vfsmount structure is only used to obtain the
538 * blockdev_superblock, so tell kmemleak not to report it.
540 kmemleak_not_leak(bd_mnt
);
541 blockdev_superblock
= bd_mnt
->mnt_sb
; /* For writeback */
545 * Most likely _very_ bad one - but then it's hardly critical for small
546 * /dev and can be fixed when somebody will need really large one.
547 * Keep in mind that it will be fed through icache hash function too.
549 static inline unsigned long hash(dev_t dev
)
551 return MAJOR(dev
)+MINOR(dev
);
554 static int bdev_test(struct inode
*inode
, void *data
)
556 return BDEV_I(inode
)->bdev
.bd_dev
== *(dev_t
*)data
;
559 static int bdev_set(struct inode
*inode
, void *data
)
561 BDEV_I(inode
)->bdev
.bd_dev
= *(dev_t
*)data
;
565 static LIST_HEAD(all_bdevs
);
567 struct block_device
*bdget(dev_t dev
)
569 struct block_device
*bdev
;
572 inode
= iget5_locked(blockdev_superblock
, hash(dev
),
573 bdev_test
, bdev_set
, &dev
);
578 bdev
= &BDEV_I(inode
)->bdev
;
580 if (inode
->i_state
& I_NEW
) {
581 bdev
->bd_contains
= NULL
;
582 bdev
->bd_super
= NULL
;
583 bdev
->bd_inode
= inode
;
584 bdev
->bd_block_size
= (1 << inode
->i_blkbits
);
585 bdev
->bd_part_count
= 0;
586 bdev
->bd_invalidated
= 0;
587 inode
->i_mode
= S_IFBLK
;
589 inode
->i_bdev
= bdev
;
590 inode
->i_data
.a_ops
= &def_blk_aops
;
591 mapping_set_gfp_mask(&inode
->i_data
, GFP_USER
);
592 inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
593 spin_lock(&bdev_lock
);
594 list_add(&bdev
->bd_list
, &all_bdevs
);
595 spin_unlock(&bdev_lock
);
596 unlock_new_inode(inode
);
601 EXPORT_SYMBOL(bdget
);
604 * bdgrab -- Grab a reference to an already referenced block device
605 * @bdev: Block device to grab a reference to.
607 struct block_device
*bdgrab(struct block_device
*bdev
)
609 ihold(bdev
->bd_inode
);
613 long nr_blockdev_pages(void)
615 struct block_device
*bdev
;
617 spin_lock(&bdev_lock
);
618 list_for_each_entry(bdev
, &all_bdevs
, bd_list
) {
619 ret
+= bdev
->bd_inode
->i_mapping
->nrpages
;
621 spin_unlock(&bdev_lock
);
625 void bdput(struct block_device
*bdev
)
627 iput(bdev
->bd_inode
);
630 EXPORT_SYMBOL(bdput
);
632 static struct block_device
*bd_acquire(struct inode
*inode
)
634 struct block_device
*bdev
;
636 spin_lock(&bdev_lock
);
637 bdev
= inode
->i_bdev
;
639 ihold(bdev
->bd_inode
);
640 spin_unlock(&bdev_lock
);
643 spin_unlock(&bdev_lock
);
645 bdev
= bdget(inode
->i_rdev
);
647 spin_lock(&bdev_lock
);
648 if (!inode
->i_bdev
) {
650 * We take an additional reference to bd_inode,
651 * and it's released in clear_inode() of inode.
652 * So, we can access it via ->i_mapping always
655 ihold(bdev
->bd_inode
);
656 inode
->i_bdev
= bdev
;
657 inode
->i_mapping
= bdev
->bd_inode
->i_mapping
;
658 list_add(&inode
->i_devices
, &bdev
->bd_inodes
);
660 spin_unlock(&bdev_lock
);
665 static inline int sb_is_blkdev_sb(struct super_block
*sb
)
667 return sb
== blockdev_superblock
;
670 /* Call when you free inode */
672 void bd_forget(struct inode
*inode
)
674 struct block_device
*bdev
= NULL
;
676 spin_lock(&bdev_lock
);
678 if (!sb_is_blkdev_sb(inode
->i_sb
))
679 bdev
= inode
->i_bdev
;
682 spin_unlock(&bdev_lock
);
685 iput(bdev
->bd_inode
);
689 * bd_may_claim - test whether a block device can be claimed
690 * @bdev: block device of interest
691 * @whole: whole block device containing @bdev, may equal @bdev
692 * @holder: holder trying to claim @bdev
694 * Test whether @bdev can be claimed by @holder.
697 * spin_lock(&bdev_lock).
700 * %true if @bdev can be claimed, %false otherwise.
702 static bool bd_may_claim(struct block_device
*bdev
, struct block_device
*whole
,
705 if (bdev
->bd_holder
== holder
)
706 return true; /* already a holder */
707 else if (bdev
->bd_holder
!= NULL
)
708 return false; /* held by someone else */
709 else if (bdev
->bd_contains
== bdev
)
710 return true; /* is a whole device which isn't held */
712 else if (whole
->bd_holder
== bd_may_claim
)
713 return true; /* is a partition of a device that is being partitioned */
714 else if (whole
->bd_holder
!= NULL
)
715 return false; /* is a partition of a held device */
717 return true; /* is a partition of an un-held device */
721 * bd_prepare_to_claim - prepare to claim a block device
722 * @bdev: block device of interest
723 * @whole: the whole device containing @bdev, may equal @bdev
724 * @holder: holder trying to claim @bdev
726 * Prepare to claim @bdev. This function fails if @bdev is already
727 * claimed by another holder and waits if another claiming is in
728 * progress. This function doesn't actually claim. On successful
729 * return, the caller has ownership of bd_claiming and bd_holder[s].
732 * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab
736 * 0 if @bdev can be claimed, -EBUSY otherwise.
738 static int bd_prepare_to_claim(struct block_device
*bdev
,
739 struct block_device
*whole
, void *holder
)
742 /* if someone else claimed, fail */
743 if (!bd_may_claim(bdev
, whole
, holder
))
746 /* if claiming is already in progress, wait for it to finish */
747 if (whole
->bd_claiming
) {
748 wait_queue_head_t
*wq
= bit_waitqueue(&whole
->bd_claiming
, 0);
751 prepare_to_wait(wq
, &wait
, TASK_UNINTERRUPTIBLE
);
752 spin_unlock(&bdev_lock
);
754 finish_wait(wq
, &wait
);
755 spin_lock(&bdev_lock
);
764 * bd_start_claiming - start claiming a block device
765 * @bdev: block device of interest
766 * @holder: holder trying to claim @bdev
768 * @bdev is about to be opened exclusively. Check @bdev can be opened
769 * exclusively and mark that an exclusive open is in progress. Each
770 * successful call to this function must be matched with a call to
771 * either bd_finish_claiming() or bd_abort_claiming() (which do not
774 * This function is used to gain exclusive access to the block device
775 * without actually causing other exclusive open attempts to fail. It
776 * should be used when the open sequence itself requires exclusive
777 * access but may subsequently fail.
783 * Pointer to the block device containing @bdev on success, ERR_PTR()
786 static struct block_device
*bd_start_claiming(struct block_device
*bdev
,
789 struct gendisk
*disk
;
790 struct block_device
*whole
;
796 * @bdev might not have been initialized properly yet, look up
797 * and grab the outer block device the hard way.
799 disk
= get_gendisk(bdev
->bd_dev
, &partno
);
801 return ERR_PTR(-ENXIO
);
804 * Normally, @bdev should equal what's returned from bdget_disk()
805 * if partno is 0; however, some drivers (floppy) use multiple
806 * bdev's for the same physical device and @bdev may be one of the
807 * aliases. Keep @bdev if partno is 0. This means claimer
808 * tracking is broken for those devices but it has always been that
812 whole
= bdget_disk(disk
, 0);
814 whole
= bdgrab(bdev
);
816 module_put(disk
->fops
->owner
);
819 return ERR_PTR(-ENOMEM
);
821 /* prepare to claim, if successful, mark claiming in progress */
822 spin_lock(&bdev_lock
);
824 err
= bd_prepare_to_claim(bdev
, whole
, holder
);
826 whole
->bd_claiming
= holder
;
827 spin_unlock(&bdev_lock
);
830 spin_unlock(&bdev_lock
);
837 struct bd_holder_disk
{
838 struct list_head list
;
839 struct gendisk
*disk
;
843 static struct bd_holder_disk
*bd_find_holder_disk(struct block_device
*bdev
,
844 struct gendisk
*disk
)
846 struct bd_holder_disk
*holder
;
848 list_for_each_entry(holder
, &bdev
->bd_holder_disks
, list
)
849 if (holder
->disk
== disk
)
854 static int add_symlink(struct kobject
*from
, struct kobject
*to
)
856 return sysfs_create_link(from
, to
, kobject_name(to
));
859 static void del_symlink(struct kobject
*from
, struct kobject
*to
)
861 sysfs_remove_link(from
, kobject_name(to
));
865 * bd_link_disk_holder - create symlinks between holding disk and slave bdev
866 * @bdev: the claimed slave bdev
867 * @disk: the holding disk
869 * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
871 * This functions creates the following sysfs symlinks.
873 * - from "slaves" directory of the holder @disk to the claimed @bdev
874 * - from "holders" directory of the @bdev to the holder @disk
876 * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is
877 * passed to bd_link_disk_holder(), then:
879 * /sys/block/dm-0/slaves/sda --> /sys/block/sda
880 * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
882 * The caller must have claimed @bdev before calling this function and
883 * ensure that both @bdev and @disk are valid during the creation and
884 * lifetime of these symlinks.
890 * 0 on success, -errno on failure.
892 int bd_link_disk_holder(struct block_device
*bdev
, struct gendisk
*disk
)
894 struct bd_holder_disk
*holder
;
897 mutex_lock(&bdev
->bd_mutex
);
899 WARN_ON_ONCE(!bdev
->bd_holder
);
901 /* FIXME: remove the following once add_disk() handles errors */
902 if (WARN_ON(!disk
->slave_dir
|| !bdev
->bd_part
->holder_dir
))
905 holder
= bd_find_holder_disk(bdev
, disk
);
911 holder
= kzalloc(sizeof(*holder
), GFP_KERNEL
);
917 INIT_LIST_HEAD(&holder
->list
);
921 ret
= add_symlink(disk
->slave_dir
, &part_to_dev(bdev
->bd_part
)->kobj
);
925 ret
= add_symlink(bdev
->bd_part
->holder_dir
, &disk_to_dev(disk
)->kobj
);
929 * bdev could be deleted beneath us which would implicitly destroy
930 * the holder directory. Hold on to it.
932 kobject_get(bdev
->bd_part
->holder_dir
);
934 list_add(&holder
->list
, &bdev
->bd_holder_disks
);
938 del_symlink(disk
->slave_dir
, &part_to_dev(bdev
->bd_part
)->kobj
);
942 mutex_unlock(&bdev
->bd_mutex
);
945 EXPORT_SYMBOL_GPL(bd_link_disk_holder
);
948 * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder()
949 * @bdev: the calimed slave bdev
950 * @disk: the holding disk
952 * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
957 void bd_unlink_disk_holder(struct block_device
*bdev
, struct gendisk
*disk
)
959 struct bd_holder_disk
*holder
;
961 mutex_lock(&bdev
->bd_mutex
);
963 holder
= bd_find_holder_disk(bdev
, disk
);
965 if (!WARN_ON_ONCE(holder
== NULL
) && !--holder
->refcnt
) {
966 del_symlink(disk
->slave_dir
, &part_to_dev(bdev
->bd_part
)->kobj
);
967 del_symlink(bdev
->bd_part
->holder_dir
,
968 &disk_to_dev(disk
)->kobj
);
969 kobject_put(bdev
->bd_part
->holder_dir
);
970 list_del_init(&holder
->list
);
974 mutex_unlock(&bdev
->bd_mutex
);
976 EXPORT_SYMBOL_GPL(bd_unlink_disk_holder
);
980 * flush_disk - invalidates all buffer-cache entries on a disk
982 * @bdev: struct block device to be flushed
983 * @kill_dirty: flag to guide handling of dirty inodes
985 * Invalidates all buffer-cache entries on a disk. It should be called
986 * when a disk has been changed -- either by a media change or online
989 static void flush_disk(struct block_device
*bdev
, bool kill_dirty
)
991 if (__invalidate_device(bdev
, kill_dirty
)) {
992 char name
[BDEVNAME_SIZE
] = "";
995 disk_name(bdev
->bd_disk
, 0, name
);
996 printk(KERN_WARNING
"VFS: busy inodes on changed media or "
997 "resized disk %s\n", name
);
1002 if (disk_part_scan_enabled(bdev
->bd_disk
))
1003 bdev
->bd_invalidated
= 1;
1007 * check_disk_size_change - checks for disk size change and adjusts bdev size.
1008 * @disk: struct gendisk to check
1009 * @bdev: struct bdev to adjust.
1011 * This routine checks to see if the bdev size does not match the disk size
1012 * and adjusts it if it differs.
1014 void check_disk_size_change(struct gendisk
*disk
, struct block_device
*bdev
)
1016 loff_t disk_size
, bdev_size
;
1018 disk_size
= (loff_t
)get_capacity(disk
) << 9;
1019 bdev_size
= i_size_read(bdev
->bd_inode
);
1020 if (disk_size
!= bdev_size
) {
1021 char name
[BDEVNAME_SIZE
];
1023 disk_name(disk
, 0, name
);
1025 "%s: detected capacity change from %lld to %lld\n",
1026 name
, bdev_size
, disk_size
);
1027 i_size_write(bdev
->bd_inode
, disk_size
);
1028 flush_disk(bdev
, false);
1031 EXPORT_SYMBOL(check_disk_size_change
);
1034 * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back
1035 * @disk: struct gendisk to be revalidated
1037 * This routine is a wrapper for lower-level driver's revalidate_disk
1038 * call-backs. It is used to do common pre and post operations needed
1039 * for all revalidate_disk operations.
1041 int revalidate_disk(struct gendisk
*disk
)
1043 struct block_device
*bdev
;
1046 if (disk
->fops
->revalidate_disk
)
1047 ret
= disk
->fops
->revalidate_disk(disk
);
1049 bdev
= bdget_disk(disk
, 0);
1053 mutex_lock(&bdev
->bd_mutex
);
1054 check_disk_size_change(disk
, bdev
);
1055 mutex_unlock(&bdev
->bd_mutex
);
1059 EXPORT_SYMBOL(revalidate_disk
);
1062 * This routine checks whether a removable media has been changed,
1063 * and invalidates all buffer-cache-entries in that case. This
1064 * is a relatively slow routine, so we have to try to minimize using
1065 * it. Thus it is called only upon a 'mount' or 'open'. This
1066 * is the best way of combining speed and utility, I think.
1067 * People changing diskettes in the middle of an operation deserve
1070 int check_disk_change(struct block_device
*bdev
)
1072 struct gendisk
*disk
= bdev
->bd_disk
;
1073 const struct block_device_operations
*bdops
= disk
->fops
;
1074 unsigned int events
;
1076 events
= disk_clear_events(disk
, DISK_EVENT_MEDIA_CHANGE
|
1077 DISK_EVENT_EJECT_REQUEST
);
1078 if (!(events
& DISK_EVENT_MEDIA_CHANGE
))
1081 flush_disk(bdev
, true);
1082 if (bdops
->revalidate_disk
)
1083 bdops
->revalidate_disk(bdev
->bd_disk
);
1087 EXPORT_SYMBOL(check_disk_change
);
1089 void bd_set_size(struct block_device
*bdev
, loff_t size
)
1091 unsigned bsize
= bdev_logical_block_size(bdev
);
1093 bdev
->bd_inode
->i_size
= size
;
1094 while (bsize
< PAGE_CACHE_SIZE
) {
1099 bdev
->bd_block_size
= bsize
;
1100 bdev
->bd_inode
->i_blkbits
= blksize_bits(bsize
);
1102 EXPORT_SYMBOL(bd_set_size
);
1104 static int __blkdev_put(struct block_device
*bdev
, fmode_t mode
, int for_part
);
1109 * mutex_lock(part->bd_mutex)
1110 * mutex_lock_nested(whole->bd_mutex, 1)
1113 static int __blkdev_get(struct block_device
*bdev
, fmode_t mode
, int for_part
)
1115 struct gendisk
*disk
;
1116 struct module
*owner
;
1121 if (mode
& FMODE_READ
)
1123 if (mode
& FMODE_WRITE
)
1126 * hooks: /n/, see "layering violations".
1129 ret
= devcgroup_inode_permission(bdev
->bd_inode
, perm
);
1139 disk
= get_gendisk(bdev
->bd_dev
, &partno
);
1142 owner
= disk
->fops
->owner
;
1144 disk_block_events(disk
);
1145 mutex_lock_nested(&bdev
->bd_mutex
, for_part
);
1146 if (!bdev
->bd_openers
) {
1147 bdev
->bd_disk
= disk
;
1148 bdev
->bd_contains
= bdev
;
1150 struct backing_dev_info
*bdi
;
1153 bdev
->bd_part
= disk_get_part(disk
, partno
);
1158 if (disk
->fops
->open
) {
1159 ret
= disk
->fops
->open(bdev
, mode
);
1160 if (ret
== -ERESTARTSYS
) {
1161 /* Lost a race with 'disk' being
1162 * deleted, try again.
1165 disk_put_part(bdev
->bd_part
);
1166 bdev
->bd_part
= NULL
;
1167 bdev
->bd_disk
= NULL
;
1168 mutex_unlock(&bdev
->bd_mutex
);
1169 disk_unblock_events(disk
);
1176 if (!ret
&& !bdev
->bd_openers
) {
1177 bd_set_size(bdev
,(loff_t
)get_capacity(disk
)<<9);
1178 bdi
= blk_get_backing_dev_info(bdev
);
1180 bdi
= &default_backing_dev_info
;
1181 bdev_inode_switch_bdi(bdev
->bd_inode
, bdi
);
1185 * If the device is invalidated, rescan partition
1186 * if open succeeded or failed with -ENOMEDIUM.
1187 * The latter is necessary to prevent ghost
1188 * partitions on a removed medium.
1190 if (bdev
->bd_invalidated
&& (!ret
|| ret
== -ENOMEDIUM
))
1191 rescan_partitions(disk
, bdev
);
1195 struct block_device
*whole
;
1196 whole
= bdget_disk(disk
, 0);
1201 ret
= __blkdev_get(whole
, mode
, 1);
1204 bdev
->bd_contains
= whole
;
1205 bdev_inode_switch_bdi(bdev
->bd_inode
,
1206 whole
->bd_inode
->i_data
.backing_dev_info
);
1207 bdev
->bd_part
= disk_get_part(disk
, partno
);
1208 if (!(disk
->flags
& GENHD_FL_UP
) ||
1209 !bdev
->bd_part
|| !bdev
->bd_part
->nr_sects
) {
1213 bd_set_size(bdev
, (loff_t
)bdev
->bd_part
->nr_sects
<< 9);
1216 if (bdev
->bd_contains
== bdev
) {
1218 if (bdev
->bd_disk
->fops
->open
)
1219 ret
= bdev
->bd_disk
->fops
->open(bdev
, mode
);
1220 /* the same as first opener case, read comment there */
1221 if (bdev
->bd_invalidated
&& (!ret
|| ret
== -ENOMEDIUM
))
1222 rescan_partitions(bdev
->bd_disk
, bdev
);
1224 goto out_unlock_bdev
;
1226 /* only one opener holds refs to the module and disk */
1232 bdev
->bd_part_count
++;
1233 mutex_unlock(&bdev
->bd_mutex
);
1234 disk_unblock_events(disk
);
1238 disk_put_part(bdev
->bd_part
);
1239 bdev
->bd_disk
= NULL
;
1240 bdev
->bd_part
= NULL
;
1241 bdev_inode_switch_bdi(bdev
->bd_inode
, &default_backing_dev_info
);
1242 if (bdev
!= bdev
->bd_contains
)
1243 __blkdev_put(bdev
->bd_contains
, mode
, 1);
1244 bdev
->bd_contains
= NULL
;
1246 mutex_unlock(&bdev
->bd_mutex
);
1247 disk_unblock_events(disk
);
1257 * blkdev_get - open a block device
1258 * @bdev: block_device to open
1259 * @mode: FMODE_* mask
1260 * @holder: exclusive holder identifier
1262 * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is
1263 * open with exclusive access. Specifying %FMODE_EXCL with %NULL
1264 * @holder is invalid. Exclusive opens may nest for the same @holder.
1266 * On success, the reference count of @bdev is unchanged. On failure,
1273 * 0 on success, -errno on failure.
1275 int blkdev_get(struct block_device
*bdev
, fmode_t mode
, void *holder
)
1277 struct block_device
*whole
= NULL
;
1280 WARN_ON_ONCE((mode
& FMODE_EXCL
) && !holder
);
1282 if ((mode
& FMODE_EXCL
) && holder
) {
1283 whole
= bd_start_claiming(bdev
, holder
);
1284 if (IS_ERR(whole
)) {
1286 return PTR_ERR(whole
);
1290 res
= __blkdev_get(bdev
, mode
, 0);
1293 struct gendisk
*disk
= whole
->bd_disk
;
1295 /* finish claiming */
1296 mutex_lock(&bdev
->bd_mutex
);
1297 spin_lock(&bdev_lock
);
1300 BUG_ON(!bd_may_claim(bdev
, whole
, holder
));
1302 * Note that for a whole device bd_holders
1303 * will be incremented twice, and bd_holder
1304 * will be set to bd_may_claim before being
1307 whole
->bd_holders
++;
1308 whole
->bd_holder
= bd_may_claim
;
1310 bdev
->bd_holder
= holder
;
1313 /* tell others that we're done */
1314 BUG_ON(whole
->bd_claiming
!= holder
);
1315 whole
->bd_claiming
= NULL
;
1316 wake_up_bit(&whole
->bd_claiming
, 0);
1318 spin_unlock(&bdev_lock
);
1321 * Block event polling for write claims if requested. Any
1322 * write holder makes the write_holder state stick until
1323 * all are released. This is good enough and tracking
1324 * individual writeable reference is too fragile given the
1325 * way @mode is used in blkdev_get/put().
1327 if (!res
&& (mode
& FMODE_WRITE
) && !bdev
->bd_write_holder
&&
1328 (disk
->flags
& GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE
)) {
1329 bdev
->bd_write_holder
= true;
1330 disk_block_events(disk
);
1333 mutex_unlock(&bdev
->bd_mutex
);
1339 EXPORT_SYMBOL(blkdev_get
);
1342 * blkdev_get_by_path - open a block device by name
1343 * @path: path to the block device to open
1344 * @mode: FMODE_* mask
1345 * @holder: exclusive holder identifier
1347 * Open the blockdevice described by the device file at @path. @mode
1348 * and @holder are identical to blkdev_get().
1350 * On success, the returned block_device has reference count of one.
1356 * Pointer to block_device on success, ERR_PTR(-errno) on failure.
1358 struct block_device
*blkdev_get_by_path(const char *path
, fmode_t mode
,
1361 struct block_device
*bdev
;
1364 bdev
= lookup_bdev(path
);
1368 err
= blkdev_get(bdev
, mode
, holder
);
1370 return ERR_PTR(err
);
1372 if ((mode
& FMODE_WRITE
) && bdev_read_only(bdev
)) {
1373 blkdev_put(bdev
, mode
);
1374 return ERR_PTR(-EACCES
);
1379 EXPORT_SYMBOL(blkdev_get_by_path
);
1382 * blkdev_get_by_dev - open a block device by device number
1383 * @dev: device number of block device to open
1384 * @mode: FMODE_* mask
1385 * @holder: exclusive holder identifier
1387 * Open the blockdevice described by device number @dev. @mode and
1388 * @holder are identical to blkdev_get().
1390 * Use it ONLY if you really do not have anything better - i.e. when
1391 * you are behind a truly sucky interface and all you are given is a
1392 * device number. _Never_ to be used for internal purposes. If you
1393 * ever need it - reconsider your API.
1395 * On success, the returned block_device has reference count of one.
1401 * Pointer to block_device on success, ERR_PTR(-errno) on failure.
1403 struct block_device
*blkdev_get_by_dev(dev_t dev
, fmode_t mode
, void *holder
)
1405 struct block_device
*bdev
;
1410 return ERR_PTR(-ENOMEM
);
1412 err
= blkdev_get(bdev
, mode
, holder
);
1414 return ERR_PTR(err
);
1418 EXPORT_SYMBOL(blkdev_get_by_dev
);
1420 static int blkdev_open(struct inode
* inode
, struct file
* filp
)
1422 struct block_device
*bdev
;
1425 * Preserve backwards compatibility and allow large file access
1426 * even if userspace doesn't ask for it explicitly. Some mkfs
1427 * binary needs it. We might want to drop this workaround
1428 * during an unstable branch.
1430 filp
->f_flags
|= O_LARGEFILE
;
1432 if (filp
->f_flags
& O_NDELAY
)
1433 filp
->f_mode
|= FMODE_NDELAY
;
1434 if (filp
->f_flags
& O_EXCL
)
1435 filp
->f_mode
|= FMODE_EXCL
;
1436 if ((filp
->f_flags
& O_ACCMODE
) == 3)
1437 filp
->f_mode
|= FMODE_WRITE_IOCTL
;
1439 bdev
= bd_acquire(inode
);
1443 filp
->f_mapping
= bdev
->bd_inode
->i_mapping
;
1445 return blkdev_get(bdev
, filp
->f_mode
, filp
);
1448 static int __blkdev_put(struct block_device
*bdev
, fmode_t mode
, int for_part
)
1451 struct gendisk
*disk
= bdev
->bd_disk
;
1452 struct block_device
*victim
= NULL
;
1454 mutex_lock_nested(&bdev
->bd_mutex
, for_part
);
1456 bdev
->bd_part_count
--;
1458 if (!--bdev
->bd_openers
) {
1459 WARN_ON_ONCE(bdev
->bd_holders
);
1460 sync_blockdev(bdev
);
1462 /* ->release can cause the old bdi to disappear,
1463 * so must switch it out first
1465 bdev_inode_switch_bdi(bdev
->bd_inode
,
1466 &default_backing_dev_info
);
1468 if (bdev
->bd_contains
== bdev
) {
1469 if (disk
->fops
->release
)
1470 ret
= disk
->fops
->release(disk
, mode
);
1472 if (!bdev
->bd_openers
) {
1473 struct module
*owner
= disk
->fops
->owner
;
1475 disk_put_part(bdev
->bd_part
);
1476 bdev
->bd_part
= NULL
;
1477 bdev
->bd_disk
= NULL
;
1478 if (bdev
!= bdev
->bd_contains
)
1479 victim
= bdev
->bd_contains
;
1480 bdev
->bd_contains
= NULL
;
1485 mutex_unlock(&bdev
->bd_mutex
);
1488 __blkdev_put(victim
, mode
, 1);
1492 int blkdev_put(struct block_device
*bdev
, fmode_t mode
)
1494 mutex_lock(&bdev
->bd_mutex
);
1496 if (mode
& FMODE_EXCL
) {
1500 * Release a claim on the device. The holder fields
1501 * are protected with bdev_lock. bd_mutex is to
1502 * synchronize disk_holder unlinking.
1504 spin_lock(&bdev_lock
);
1506 WARN_ON_ONCE(--bdev
->bd_holders
< 0);
1507 WARN_ON_ONCE(--bdev
->bd_contains
->bd_holders
< 0);
1509 /* bd_contains might point to self, check in a separate step */
1510 if ((bdev_free
= !bdev
->bd_holders
))
1511 bdev
->bd_holder
= NULL
;
1512 if (!bdev
->bd_contains
->bd_holders
)
1513 bdev
->bd_contains
->bd_holder
= NULL
;
1515 spin_unlock(&bdev_lock
);
1518 * If this was the last claim, remove holder link and
1519 * unblock evpoll if it was a write holder.
1521 if (bdev_free
&& bdev
->bd_write_holder
) {
1522 disk_unblock_events(bdev
->bd_disk
);
1523 bdev
->bd_write_holder
= false;
1528 * Trigger event checking and tell drivers to flush MEDIA_CHANGE
1529 * event. This is to ensure detection of media removal commanded
1530 * from userland - e.g. eject(1).
1532 disk_flush_events(bdev
->bd_disk
, DISK_EVENT_MEDIA_CHANGE
);
1534 mutex_unlock(&bdev
->bd_mutex
);
1536 return __blkdev_put(bdev
, mode
, 0);
1538 EXPORT_SYMBOL(blkdev_put
);
1540 static int blkdev_close(struct inode
* inode
, struct file
* filp
)
1542 struct block_device
*bdev
= I_BDEV(filp
->f_mapping
->host
);
1544 return blkdev_put(bdev
, filp
->f_mode
);
1547 static long block_ioctl(struct file
*file
, unsigned cmd
, unsigned long arg
)
1549 struct block_device
*bdev
= I_BDEV(file
->f_mapping
->host
);
1550 fmode_t mode
= file
->f_mode
;
1553 * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
1554 * to updated it before every ioctl.
1556 if (file
->f_flags
& O_NDELAY
)
1557 mode
|= FMODE_NDELAY
;
1559 mode
&= ~FMODE_NDELAY
;
1561 return blkdev_ioctl(bdev
, mode
, cmd
, arg
);
1565 * Write data to the block device. Only intended for the block device itself
1566 * and the raw driver which basically is a fake block device.
1568 * Does not take i_mutex for the write and thus is not for general purpose
1571 ssize_t
blkdev_aio_write(struct kiocb
*iocb
, const struct iovec
*iov
,
1572 unsigned long nr_segs
, loff_t pos
)
1574 struct file
*file
= iocb
->ki_filp
;
1577 BUG_ON(iocb
->ki_pos
!= pos
);
1579 ret
= __generic_file_aio_write(iocb
, iov
, nr_segs
, &iocb
->ki_pos
);
1580 if (ret
> 0 || ret
== -EIOCBQUEUED
) {
1583 err
= generic_write_sync(file
, pos
, ret
);
1584 if (err
< 0 && ret
> 0)
1589 EXPORT_SYMBOL_GPL(blkdev_aio_write
);
1592 * Try to release a page associated with block device when the system
1593 * is under memory pressure.
1595 static int blkdev_releasepage(struct page
*page
, gfp_t wait
)
1597 struct super_block
*super
= BDEV_I(page
->mapping
->host
)->bdev
.bd_super
;
1599 if (super
&& super
->s_op
->bdev_try_to_free_page
)
1600 return super
->s_op
->bdev_try_to_free_page(super
, page
, wait
);
1602 return try_to_free_buffers(page
);
1605 static const struct address_space_operations def_blk_aops
= {
1606 .readpage
= blkdev_readpage
,
1607 .writepage
= blkdev_writepage
,
1608 .write_begin
= blkdev_write_begin
,
1609 .write_end
= blkdev_write_end
,
1610 .writepages
= generic_writepages
,
1611 .releasepage
= blkdev_releasepage
,
1612 .direct_IO
= blkdev_direct_IO
,
1615 const struct file_operations def_blk_fops
= {
1616 .open
= blkdev_open
,
1617 .release
= blkdev_close
,
1618 .llseek
= block_llseek
,
1619 .read
= do_sync_read
,
1620 .write
= do_sync_write
,
1621 .aio_read
= generic_file_aio_read
,
1622 .aio_write
= blkdev_aio_write
,
1623 .mmap
= generic_file_mmap
,
1624 .fsync
= blkdev_fsync
,
1625 .unlocked_ioctl
= block_ioctl
,
1626 #ifdef CONFIG_COMPAT
1627 .compat_ioctl
= compat_blkdev_ioctl
,
1629 .splice_read
= generic_file_splice_read
,
1630 .splice_write
= generic_file_splice_write
,
1633 int ioctl_by_bdev(struct block_device
*bdev
, unsigned cmd
, unsigned long arg
)
1636 mm_segment_t old_fs
= get_fs();
1638 res
= blkdev_ioctl(bdev
, 0, cmd
, arg
);
1643 EXPORT_SYMBOL(ioctl_by_bdev
);
1646 * lookup_bdev - lookup a struct block_device by name
1647 * @pathname: special file representing the block device
1649 * Get a reference to the blockdevice at @pathname in the current
1650 * namespace if possible and return it. Return ERR_PTR(error)
1653 struct block_device
*lookup_bdev(const char *pathname
)
1655 struct block_device
*bdev
;
1656 struct inode
*inode
;
1660 if (!pathname
|| !*pathname
)
1661 return ERR_PTR(-EINVAL
);
1663 error
= kern_path(pathname
, LOOKUP_FOLLOW
, &path
);
1665 return ERR_PTR(error
);
1667 inode
= path
.dentry
->d_inode
;
1669 if (!S_ISBLK(inode
->i_mode
))
1672 if (path
.mnt
->mnt_flags
& MNT_NODEV
)
1675 bdev
= bd_acquire(inode
);
1682 bdev
= ERR_PTR(error
);
1685 EXPORT_SYMBOL(lookup_bdev
);
1687 int __invalidate_device(struct block_device
*bdev
, bool kill_dirty
)
1689 struct super_block
*sb
= get_super(bdev
);
1694 * no need to lock the super, get_super holds the
1695 * read mutex so the filesystem cannot go away
1696 * under us (->put_super runs with the write lock
1699 shrink_dcache_sb(sb
);
1700 res
= invalidate_inodes(sb
, kill_dirty
);
1703 invalidate_bdev(bdev
);
1706 EXPORT_SYMBOL(__invalidate_device
);