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/cleancache.h>
29 #include <asm/uaccess.h>
33 struct block_device bdev
;
34 struct inode vfs_inode
;
37 static const struct address_space_operations def_blk_aops
;
39 static inline struct bdev_inode
*BDEV_I(struct inode
*inode
)
41 return container_of(inode
, struct bdev_inode
, vfs_inode
);
44 inline struct block_device
*I_BDEV(struct inode
*inode
)
46 return &BDEV_I(inode
)->bdev
;
48 EXPORT_SYMBOL(I_BDEV
);
51 * Move the inode from its current bdi to a new bdi. If the inode is dirty we
52 * need to move it onto the dirty list of @dst so that the inode is always on
55 static void bdev_inode_switch_bdi(struct inode
*inode
,
56 struct backing_dev_info
*dst
)
58 struct backing_dev_info
*old
= inode
->i_data
.backing_dev_info
;
60 if (unlikely(dst
== old
)) /* deadlock avoidance */
62 bdi_lock_two(&old
->wb
, &dst
->wb
);
63 spin_lock(&inode
->i_lock
);
64 inode
->i_data
.backing_dev_info
= dst
;
65 if (inode
->i_state
& I_DIRTY
)
66 list_move(&inode
->i_wb_list
, &dst
->wb
.b_dirty
);
67 spin_unlock(&inode
->i_lock
);
68 spin_unlock(&old
->wb
.list_lock
);
69 spin_unlock(&dst
->wb
.list_lock
);
72 static sector_t
max_block(struct block_device
*bdev
)
74 sector_t retval
= ~((sector_t
)0);
75 loff_t sz
= i_size_read(bdev
->bd_inode
);
78 unsigned int size
= block_size(bdev
);
79 unsigned int sizebits
= blksize_bits(size
);
80 retval
= (sz
>> sizebits
);
85 /* Kill _all_ buffers and pagecache , dirty or not.. */
86 void kill_bdev(struct block_device
*bdev
)
88 struct address_space
*mapping
= bdev
->bd_inode
->i_mapping
;
90 if (mapping
->nrpages
== 0)
94 truncate_inode_pages(mapping
, 0);
96 EXPORT_SYMBOL(kill_bdev
);
98 /* Invalidate clean unused buffers and pagecache. */
99 void invalidate_bdev(struct block_device
*bdev
)
101 struct address_space
*mapping
= bdev
->bd_inode
->i_mapping
;
103 if (mapping
->nrpages
== 0)
106 invalidate_bh_lrus();
107 lru_add_drain_all(); /* make sure all lru add caches are flushed */
108 invalidate_mapping_pages(mapping
, 0, -1);
109 /* 99% of the time, we don't need to flush the cleancache on the bdev.
110 * But, for the strange corners, lets be cautious
112 cleancache_flush_inode(mapping
);
114 EXPORT_SYMBOL(invalidate_bdev
);
116 int set_blocksize(struct block_device
*bdev
, int size
)
118 /* Size must be a power of two, and between 512 and PAGE_SIZE */
119 if (size
> PAGE_SIZE
|| size
< 512 || !is_power_of_2(size
))
122 /* Size cannot be smaller than the size supported by the device */
123 if (size
< bdev_logical_block_size(bdev
))
126 /* Don't change the size if it is same as current */
127 if (bdev
->bd_block_size
!= size
) {
129 bdev
->bd_block_size
= size
;
130 bdev
->bd_inode
->i_blkbits
= blksize_bits(size
);
136 EXPORT_SYMBOL(set_blocksize
);
138 int sb_set_blocksize(struct super_block
*sb
, int size
)
140 if (set_blocksize(sb
->s_bdev
, size
))
142 /* If we get here, we know size is power of two
143 * and it's value is between 512 and PAGE_SIZE */
144 sb
->s_blocksize
= size
;
145 sb
->s_blocksize_bits
= blksize_bits(size
);
146 return sb
->s_blocksize
;
149 EXPORT_SYMBOL(sb_set_blocksize
);
151 int sb_min_blocksize(struct super_block
*sb
, int size
)
153 int minsize
= bdev_logical_block_size(sb
->s_bdev
);
156 return sb_set_blocksize(sb
, size
);
159 EXPORT_SYMBOL(sb_min_blocksize
);
162 blkdev_get_block(struct inode
*inode
, sector_t iblock
,
163 struct buffer_head
*bh
, int create
)
165 if (iblock
>= max_block(I_BDEV(inode
))) {
170 * for reads, we're just trying to fill a partial page.
171 * return a hole, they will have to call get_block again
172 * before they can fill it, and they will get -EIO at that
177 bh
->b_bdev
= I_BDEV(inode
);
178 bh
->b_blocknr
= iblock
;
179 set_buffer_mapped(bh
);
184 blkdev_get_blocks(struct inode
*inode
, sector_t iblock
,
185 struct buffer_head
*bh
, int create
)
187 sector_t end_block
= max_block(I_BDEV(inode
));
188 unsigned long max_blocks
= bh
->b_size
>> inode
->i_blkbits
;
190 if ((iblock
+ max_blocks
) > end_block
) {
191 max_blocks
= end_block
- iblock
;
192 if ((long)max_blocks
<= 0) {
194 return -EIO
; /* write fully beyond EOF */
196 * It is a read which is fully beyond EOF. We return
197 * a !buffer_mapped buffer
203 bh
->b_bdev
= I_BDEV(inode
);
204 bh
->b_blocknr
= iblock
;
205 bh
->b_size
= max_blocks
<< inode
->i_blkbits
;
207 set_buffer_mapped(bh
);
212 blkdev_direct_IO(int rw
, struct kiocb
*iocb
, const struct iovec
*iov
,
213 loff_t offset
, unsigned long nr_segs
)
215 struct file
*file
= iocb
->ki_filp
;
216 struct inode
*inode
= file
->f_mapping
->host
;
218 return __blockdev_direct_IO(rw
, iocb
, inode
, I_BDEV(inode
), iov
, offset
,
219 nr_segs
, blkdev_get_blocks
, NULL
, NULL
, 0);
222 int __sync_blockdev(struct block_device
*bdev
, int wait
)
227 return filemap_flush(bdev
->bd_inode
->i_mapping
);
228 return filemap_write_and_wait(bdev
->bd_inode
->i_mapping
);
232 * Write out and wait upon all the dirty data associated with a block
233 * device via its mapping. Does not take the superblock lock.
235 int sync_blockdev(struct block_device
*bdev
)
237 return __sync_blockdev(bdev
, 1);
239 EXPORT_SYMBOL(sync_blockdev
);
242 * Write out and wait upon all dirty data associated with this
243 * device. Filesystem data as well as the underlying block
244 * device. Takes the superblock lock.
246 int fsync_bdev(struct block_device
*bdev
)
248 struct super_block
*sb
= get_super(bdev
);
250 int res
= sync_filesystem(sb
);
254 return sync_blockdev(bdev
);
256 EXPORT_SYMBOL(fsync_bdev
);
259 * freeze_bdev -- lock a filesystem and force it into a consistent state
260 * @bdev: blockdevice to lock
262 * If a superblock is found on this device, we take the s_umount semaphore
263 * on it to make sure nobody unmounts until the snapshot creation is done.
264 * The reference counter (bd_fsfreeze_count) guarantees that only the last
265 * unfreeze process can unfreeze the frozen filesystem actually when multiple
266 * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
267 * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
270 struct super_block
*freeze_bdev(struct block_device
*bdev
)
272 struct super_block
*sb
;
275 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
276 if (++bdev
->bd_fsfreeze_count
> 1) {
278 * We don't even need to grab a reference - the first call
279 * to freeze_bdev grab an active reference and only the last
280 * thaw_bdev drops it.
282 sb
= get_super(bdev
);
284 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
288 sb
= get_active_super(bdev
);
291 error
= freeze_super(sb
);
293 deactivate_super(sb
);
294 bdev
->bd_fsfreeze_count
--;
295 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
296 return ERR_PTR(error
);
298 deactivate_super(sb
);
301 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
302 return sb
; /* thaw_bdev releases s->s_umount */
304 EXPORT_SYMBOL(freeze_bdev
);
307 * thaw_bdev -- unlock filesystem
308 * @bdev: blockdevice to unlock
309 * @sb: associated superblock
311 * Unlocks the filesystem and marks it writeable again after freeze_bdev().
313 int thaw_bdev(struct block_device
*bdev
, struct super_block
*sb
)
317 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
318 if (!bdev
->bd_fsfreeze_count
)
322 if (--bdev
->bd_fsfreeze_count
> 0)
328 error
= thaw_super(sb
);
330 bdev
->bd_fsfreeze_count
++;
331 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
335 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
338 EXPORT_SYMBOL(thaw_bdev
);
340 static int blkdev_writepage(struct page
*page
, struct writeback_control
*wbc
)
342 return block_write_full_page(page
, blkdev_get_block
, wbc
);
345 static int blkdev_readpage(struct file
* file
, struct page
* page
)
347 return block_read_full_page(page
, blkdev_get_block
);
350 static int blkdev_write_begin(struct file
*file
, struct address_space
*mapping
,
351 loff_t pos
, unsigned len
, unsigned flags
,
352 struct page
**pagep
, void **fsdata
)
354 return block_write_begin(mapping
, pos
, len
, flags
, pagep
,
358 static int blkdev_write_end(struct file
*file
, struct address_space
*mapping
,
359 loff_t pos
, unsigned len
, unsigned copied
,
360 struct page
*page
, void *fsdata
)
363 ret
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
366 page_cache_release(page
);
373 * for a block special file file->f_path.dentry->d_inode->i_size is zero
374 * so we compute the size by hand (just as in block_read/write above)
376 static loff_t
block_llseek(struct file
*file
, loff_t offset
, int origin
)
378 struct inode
*bd_inode
= file
->f_mapping
->host
;
382 mutex_lock(&bd_inode
->i_mutex
);
383 size
= i_size_read(bd_inode
);
391 offset
+= file
->f_pos
;
397 if (offset
>= 0 && offset
<= size
) {
398 if (offset
!= file
->f_pos
) {
399 file
->f_pos
= offset
;
404 mutex_unlock(&bd_inode
->i_mutex
);
408 int blkdev_fsync(struct file
*filp
, loff_t start
, loff_t end
, int datasync
)
410 struct inode
*bd_inode
= filp
->f_mapping
->host
;
411 struct block_device
*bdev
= I_BDEV(bd_inode
);
414 error
= filemap_write_and_wait_range(filp
->f_mapping
, start
, end
);
419 * There is no need to serialise calls to blkdev_issue_flush with
420 * i_mutex and doing so causes performance issues with concurrent
421 * O_SYNC writers to a block device.
423 error
= blkdev_issue_flush(bdev
, GFP_KERNEL
, NULL
);
424 if (error
== -EOPNOTSUPP
)
429 EXPORT_SYMBOL(blkdev_fsync
);
435 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(bdev_lock
);
436 static struct kmem_cache
* bdev_cachep __read_mostly
;
438 static struct inode
*bdev_alloc_inode(struct super_block
*sb
)
440 struct bdev_inode
*ei
= kmem_cache_alloc(bdev_cachep
, GFP_KERNEL
);
443 return &ei
->vfs_inode
;
446 static void bdev_i_callback(struct rcu_head
*head
)
448 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
449 struct bdev_inode
*bdi
= BDEV_I(inode
);
451 kmem_cache_free(bdev_cachep
, bdi
);
454 static void bdev_destroy_inode(struct inode
*inode
)
456 call_rcu(&inode
->i_rcu
, bdev_i_callback
);
459 static void init_once(void *foo
)
461 struct bdev_inode
*ei
= (struct bdev_inode
*) foo
;
462 struct block_device
*bdev
= &ei
->bdev
;
464 memset(bdev
, 0, sizeof(*bdev
));
465 mutex_init(&bdev
->bd_mutex
);
466 INIT_LIST_HEAD(&bdev
->bd_inodes
);
467 INIT_LIST_HEAD(&bdev
->bd_list
);
469 INIT_LIST_HEAD(&bdev
->bd_holder_disks
);
471 inode_init_once(&ei
->vfs_inode
);
472 /* Initialize mutex for freeze. */
473 mutex_init(&bdev
->bd_fsfreeze_mutex
);
476 static inline void __bd_forget(struct inode
*inode
)
478 list_del_init(&inode
->i_devices
);
479 inode
->i_bdev
= NULL
;
480 inode
->i_mapping
= &inode
->i_data
;
483 static void bdev_evict_inode(struct inode
*inode
)
485 struct block_device
*bdev
= &BDEV_I(inode
)->bdev
;
487 truncate_inode_pages(&inode
->i_data
, 0);
488 invalidate_inode_buffers(inode
); /* is it needed here? */
489 end_writeback(inode
);
490 spin_lock(&bdev_lock
);
491 while ( (p
= bdev
->bd_inodes
.next
) != &bdev
->bd_inodes
) {
492 __bd_forget(list_entry(p
, struct inode
, i_devices
));
494 list_del_init(&bdev
->bd_list
);
495 spin_unlock(&bdev_lock
);
498 static const struct super_operations bdev_sops
= {
499 .statfs
= simple_statfs
,
500 .alloc_inode
= bdev_alloc_inode
,
501 .destroy_inode
= bdev_destroy_inode
,
502 .drop_inode
= generic_delete_inode
,
503 .evict_inode
= bdev_evict_inode
,
506 static struct dentry
*bd_mount(struct file_system_type
*fs_type
,
507 int flags
, const char *dev_name
, void *data
)
509 return mount_pseudo(fs_type
, "bdev:", &bdev_sops
, NULL
, 0x62646576);
512 static struct file_system_type bd_type
= {
515 .kill_sb
= kill_anon_super
,
518 static struct super_block
*blockdev_superblock __read_mostly
;
520 void __init
bdev_cache_init(void)
523 static struct vfsmount
*bd_mnt
;
525 bdev_cachep
= kmem_cache_create("bdev_cache", sizeof(struct bdev_inode
),
526 0, (SLAB_HWCACHE_ALIGN
|SLAB_RECLAIM_ACCOUNT
|
527 SLAB_MEM_SPREAD
|SLAB_PANIC
),
529 err
= register_filesystem(&bd_type
);
531 panic("Cannot register bdev pseudo-fs");
532 bd_mnt
= kern_mount(&bd_type
);
534 panic("Cannot create bdev pseudo-fs");
535 blockdev_superblock
= bd_mnt
->mnt_sb
; /* For writeback */
539 * Most likely _very_ bad one - but then it's hardly critical for small
540 * /dev and can be fixed when somebody will need really large one.
541 * Keep in mind that it will be fed through icache hash function too.
543 static inline unsigned long hash(dev_t dev
)
545 return MAJOR(dev
)+MINOR(dev
);
548 static int bdev_test(struct inode
*inode
, void *data
)
550 return BDEV_I(inode
)->bdev
.bd_dev
== *(dev_t
*)data
;
553 static int bdev_set(struct inode
*inode
, void *data
)
555 BDEV_I(inode
)->bdev
.bd_dev
= *(dev_t
*)data
;
559 static LIST_HEAD(all_bdevs
);
561 struct block_device
*bdget(dev_t dev
)
563 struct block_device
*bdev
;
566 inode
= iget5_locked(blockdev_superblock
, hash(dev
),
567 bdev_test
, bdev_set
, &dev
);
572 bdev
= &BDEV_I(inode
)->bdev
;
574 if (inode
->i_state
& I_NEW
) {
575 bdev
->bd_contains
= NULL
;
576 bdev
->bd_super
= NULL
;
577 bdev
->bd_inode
= inode
;
578 bdev
->bd_block_size
= (1 << inode
->i_blkbits
);
579 bdev
->bd_part_count
= 0;
580 bdev
->bd_invalidated
= 0;
581 inode
->i_mode
= S_IFBLK
;
583 inode
->i_bdev
= bdev
;
584 inode
->i_data
.a_ops
= &def_blk_aops
;
585 mapping_set_gfp_mask(&inode
->i_data
, GFP_USER
);
586 inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
587 spin_lock(&bdev_lock
);
588 list_add(&bdev
->bd_list
, &all_bdevs
);
589 spin_unlock(&bdev_lock
);
590 unlock_new_inode(inode
);
595 EXPORT_SYMBOL(bdget
);
598 * bdgrab -- Grab a reference to an already referenced block device
599 * @bdev: Block device to grab a reference to.
601 struct block_device
*bdgrab(struct block_device
*bdev
)
603 ihold(bdev
->bd_inode
);
607 long nr_blockdev_pages(void)
609 struct block_device
*bdev
;
611 spin_lock(&bdev_lock
);
612 list_for_each_entry(bdev
, &all_bdevs
, bd_list
) {
613 ret
+= bdev
->bd_inode
->i_mapping
->nrpages
;
615 spin_unlock(&bdev_lock
);
619 void bdput(struct block_device
*bdev
)
621 iput(bdev
->bd_inode
);
624 EXPORT_SYMBOL(bdput
);
626 static struct block_device
*bd_acquire(struct inode
*inode
)
628 struct block_device
*bdev
;
630 spin_lock(&bdev_lock
);
631 bdev
= inode
->i_bdev
;
633 ihold(bdev
->bd_inode
);
634 spin_unlock(&bdev_lock
);
637 spin_unlock(&bdev_lock
);
639 bdev
= bdget(inode
->i_rdev
);
641 spin_lock(&bdev_lock
);
642 if (!inode
->i_bdev
) {
644 * We take an additional reference to bd_inode,
645 * and it's released in clear_inode() of inode.
646 * So, we can access it via ->i_mapping always
649 ihold(bdev
->bd_inode
);
650 inode
->i_bdev
= bdev
;
651 inode
->i_mapping
= bdev
->bd_inode
->i_mapping
;
652 list_add(&inode
->i_devices
, &bdev
->bd_inodes
);
654 spin_unlock(&bdev_lock
);
659 static inline int sb_is_blkdev_sb(struct super_block
*sb
)
661 return sb
== blockdev_superblock
;
664 /* Call when you free inode */
666 void bd_forget(struct inode
*inode
)
668 struct block_device
*bdev
= NULL
;
670 spin_lock(&bdev_lock
);
672 if (!sb_is_blkdev_sb(inode
->i_sb
))
673 bdev
= inode
->i_bdev
;
676 spin_unlock(&bdev_lock
);
679 iput(bdev
->bd_inode
);
683 * bd_may_claim - test whether a block device can be claimed
684 * @bdev: block device of interest
685 * @whole: whole block device containing @bdev, may equal @bdev
686 * @holder: holder trying to claim @bdev
688 * Test whether @bdev can be claimed by @holder.
691 * spin_lock(&bdev_lock).
694 * %true if @bdev can be claimed, %false otherwise.
696 static bool bd_may_claim(struct block_device
*bdev
, struct block_device
*whole
,
699 if (bdev
->bd_holder
== holder
)
700 return true; /* already a holder */
701 else if (bdev
->bd_holder
!= NULL
)
702 return false; /* held by someone else */
703 else if (bdev
->bd_contains
== bdev
)
704 return true; /* is a whole device which isn't held */
706 else if (whole
->bd_holder
== bd_may_claim
)
707 return true; /* is a partition of a device that is being partitioned */
708 else if (whole
->bd_holder
!= NULL
)
709 return false; /* is a partition of a held device */
711 return true; /* is a partition of an un-held device */
715 * bd_prepare_to_claim - prepare to claim a block device
716 * @bdev: block device of interest
717 * @whole: the whole device containing @bdev, may equal @bdev
718 * @holder: holder trying to claim @bdev
720 * Prepare to claim @bdev. This function fails if @bdev is already
721 * claimed by another holder and waits if another claiming is in
722 * progress. This function doesn't actually claim. On successful
723 * return, the caller has ownership of bd_claiming and bd_holder[s].
726 * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab
730 * 0 if @bdev can be claimed, -EBUSY otherwise.
732 static int bd_prepare_to_claim(struct block_device
*bdev
,
733 struct block_device
*whole
, void *holder
)
736 /* if someone else claimed, fail */
737 if (!bd_may_claim(bdev
, whole
, holder
))
740 /* if claiming is already in progress, wait for it to finish */
741 if (whole
->bd_claiming
) {
742 wait_queue_head_t
*wq
= bit_waitqueue(&whole
->bd_claiming
, 0);
745 prepare_to_wait(wq
, &wait
, TASK_UNINTERRUPTIBLE
);
746 spin_unlock(&bdev_lock
);
748 finish_wait(wq
, &wait
);
749 spin_lock(&bdev_lock
);
758 * bd_start_claiming - start claiming a block device
759 * @bdev: block device of interest
760 * @holder: holder trying to claim @bdev
762 * @bdev is about to be opened exclusively. Check @bdev can be opened
763 * exclusively and mark that an exclusive open is in progress. Each
764 * successful call to this function must be matched with a call to
765 * either bd_finish_claiming() or bd_abort_claiming() (which do not
768 * This function is used to gain exclusive access to the block device
769 * without actually causing other exclusive open attempts to fail. It
770 * should be used when the open sequence itself requires exclusive
771 * access but may subsequently fail.
777 * Pointer to the block device containing @bdev on success, ERR_PTR()
780 static struct block_device
*bd_start_claiming(struct block_device
*bdev
,
783 struct gendisk
*disk
;
784 struct block_device
*whole
;
790 * @bdev might not have been initialized properly yet, look up
791 * and grab the outer block device the hard way.
793 disk
= get_gendisk(bdev
->bd_dev
, &partno
);
795 return ERR_PTR(-ENXIO
);
798 * Normally, @bdev should equal what's returned from bdget_disk()
799 * if partno is 0; however, some drivers (floppy) use multiple
800 * bdev's for the same physical device and @bdev may be one of the
801 * aliases. Keep @bdev if partno is 0. This means claimer
802 * tracking is broken for those devices but it has always been that
806 whole
= bdget_disk(disk
, 0);
808 whole
= bdgrab(bdev
);
810 module_put(disk
->fops
->owner
);
813 return ERR_PTR(-ENOMEM
);
815 /* prepare to claim, if successful, mark claiming in progress */
816 spin_lock(&bdev_lock
);
818 err
= bd_prepare_to_claim(bdev
, whole
, holder
);
820 whole
->bd_claiming
= holder
;
821 spin_unlock(&bdev_lock
);
824 spin_unlock(&bdev_lock
);
831 struct bd_holder_disk
{
832 struct list_head list
;
833 struct gendisk
*disk
;
837 static struct bd_holder_disk
*bd_find_holder_disk(struct block_device
*bdev
,
838 struct gendisk
*disk
)
840 struct bd_holder_disk
*holder
;
842 list_for_each_entry(holder
, &bdev
->bd_holder_disks
, list
)
843 if (holder
->disk
== disk
)
848 static int add_symlink(struct kobject
*from
, struct kobject
*to
)
850 return sysfs_create_link(from
, to
, kobject_name(to
));
853 static void del_symlink(struct kobject
*from
, struct kobject
*to
)
855 sysfs_remove_link(from
, kobject_name(to
));
859 * bd_link_disk_holder - create symlinks between holding disk and slave bdev
860 * @bdev: the claimed slave bdev
861 * @disk: the holding disk
863 * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
865 * This functions creates the following sysfs symlinks.
867 * - from "slaves" directory of the holder @disk to the claimed @bdev
868 * - from "holders" directory of the @bdev to the holder @disk
870 * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is
871 * passed to bd_link_disk_holder(), then:
873 * /sys/block/dm-0/slaves/sda --> /sys/block/sda
874 * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
876 * The caller must have claimed @bdev before calling this function and
877 * ensure that both @bdev and @disk are valid during the creation and
878 * lifetime of these symlinks.
884 * 0 on success, -errno on failure.
886 int bd_link_disk_holder(struct block_device
*bdev
, struct gendisk
*disk
)
888 struct bd_holder_disk
*holder
;
891 mutex_lock(&bdev
->bd_mutex
);
893 WARN_ON_ONCE(!bdev
->bd_holder
);
895 /* FIXME: remove the following once add_disk() handles errors */
896 if (WARN_ON(!disk
->slave_dir
|| !bdev
->bd_part
->holder_dir
))
899 holder
= bd_find_holder_disk(bdev
, disk
);
905 holder
= kzalloc(sizeof(*holder
), GFP_KERNEL
);
911 INIT_LIST_HEAD(&holder
->list
);
915 ret
= add_symlink(disk
->slave_dir
, &part_to_dev(bdev
->bd_part
)->kobj
);
919 ret
= add_symlink(bdev
->bd_part
->holder_dir
, &disk_to_dev(disk
)->kobj
);
923 * bdev could be deleted beneath us which would implicitly destroy
924 * the holder directory. Hold on to it.
926 kobject_get(bdev
->bd_part
->holder_dir
);
928 list_add(&holder
->list
, &bdev
->bd_holder_disks
);
932 del_symlink(disk
->slave_dir
, &part_to_dev(bdev
->bd_part
)->kobj
);
936 mutex_unlock(&bdev
->bd_mutex
);
939 EXPORT_SYMBOL_GPL(bd_link_disk_holder
);
942 * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder()
943 * @bdev: the calimed slave bdev
944 * @disk: the holding disk
946 * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
951 void bd_unlink_disk_holder(struct block_device
*bdev
, struct gendisk
*disk
)
953 struct bd_holder_disk
*holder
;
955 mutex_lock(&bdev
->bd_mutex
);
957 holder
= bd_find_holder_disk(bdev
, disk
);
959 if (!WARN_ON_ONCE(holder
== NULL
) && !--holder
->refcnt
) {
960 del_symlink(disk
->slave_dir
, &part_to_dev(bdev
->bd_part
)->kobj
);
961 del_symlink(bdev
->bd_part
->holder_dir
,
962 &disk_to_dev(disk
)->kobj
);
963 kobject_put(bdev
->bd_part
->holder_dir
);
964 list_del_init(&holder
->list
);
968 mutex_unlock(&bdev
->bd_mutex
);
970 EXPORT_SYMBOL_GPL(bd_unlink_disk_holder
);
974 * flush_disk - invalidates all buffer-cache entries on a disk
976 * @bdev: struct block device to be flushed
977 * @kill_dirty: flag to guide handling of dirty inodes
979 * Invalidates all buffer-cache entries on a disk. It should be called
980 * when a disk has been changed -- either by a media change or online
983 static void flush_disk(struct block_device
*bdev
, bool kill_dirty
)
985 if (__invalidate_device(bdev
, kill_dirty
)) {
986 char name
[BDEVNAME_SIZE
] = "";
989 disk_name(bdev
->bd_disk
, 0, name
);
990 printk(KERN_WARNING
"VFS: busy inodes on changed media or "
991 "resized disk %s\n", name
);
996 if (disk_part_scan_enabled(bdev
->bd_disk
))
997 bdev
->bd_invalidated
= 1;
1001 * check_disk_size_change - checks for disk size change and adjusts bdev size.
1002 * @disk: struct gendisk to check
1003 * @bdev: struct bdev to adjust.
1005 * This routine checks to see if the bdev size does not match the disk size
1006 * and adjusts it if it differs.
1008 void check_disk_size_change(struct gendisk
*disk
, struct block_device
*bdev
)
1010 loff_t disk_size
, bdev_size
;
1012 disk_size
= (loff_t
)get_capacity(disk
) << 9;
1013 bdev_size
= i_size_read(bdev
->bd_inode
);
1014 if (disk_size
!= bdev_size
) {
1015 char name
[BDEVNAME_SIZE
];
1017 disk_name(disk
, 0, name
);
1019 "%s: detected capacity change from %lld to %lld\n",
1020 name
, bdev_size
, disk_size
);
1021 i_size_write(bdev
->bd_inode
, disk_size
);
1022 flush_disk(bdev
, false);
1025 EXPORT_SYMBOL(check_disk_size_change
);
1028 * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back
1029 * @disk: struct gendisk to be revalidated
1031 * This routine is a wrapper for lower-level driver's revalidate_disk
1032 * call-backs. It is used to do common pre and post operations needed
1033 * for all revalidate_disk operations.
1035 int revalidate_disk(struct gendisk
*disk
)
1037 struct block_device
*bdev
;
1040 if (disk
->fops
->revalidate_disk
)
1041 ret
= disk
->fops
->revalidate_disk(disk
);
1043 bdev
= bdget_disk(disk
, 0);
1047 mutex_lock(&bdev
->bd_mutex
);
1048 check_disk_size_change(disk
, bdev
);
1049 mutex_unlock(&bdev
->bd_mutex
);
1053 EXPORT_SYMBOL(revalidate_disk
);
1056 * This routine checks whether a removable media has been changed,
1057 * and invalidates all buffer-cache-entries in that case. This
1058 * is a relatively slow routine, so we have to try to minimize using
1059 * it. Thus it is called only upon a 'mount' or 'open'. This
1060 * is the best way of combining speed and utility, I think.
1061 * People changing diskettes in the middle of an operation deserve
1064 int check_disk_change(struct block_device
*bdev
)
1066 struct gendisk
*disk
= bdev
->bd_disk
;
1067 const struct block_device_operations
*bdops
= disk
->fops
;
1068 unsigned int events
;
1070 events
= disk_clear_events(disk
, DISK_EVENT_MEDIA_CHANGE
|
1071 DISK_EVENT_EJECT_REQUEST
);
1072 if (!(events
& DISK_EVENT_MEDIA_CHANGE
))
1075 flush_disk(bdev
, true);
1076 if (bdops
->revalidate_disk
)
1077 bdops
->revalidate_disk(bdev
->bd_disk
);
1081 EXPORT_SYMBOL(check_disk_change
);
1083 void bd_set_size(struct block_device
*bdev
, loff_t size
)
1085 unsigned bsize
= bdev_logical_block_size(bdev
);
1087 bdev
->bd_inode
->i_size
= size
;
1088 while (bsize
< PAGE_CACHE_SIZE
) {
1093 bdev
->bd_block_size
= bsize
;
1094 bdev
->bd_inode
->i_blkbits
= blksize_bits(bsize
);
1096 EXPORT_SYMBOL(bd_set_size
);
1098 static int __blkdev_put(struct block_device
*bdev
, fmode_t mode
, int for_part
);
1103 * mutex_lock(part->bd_mutex)
1104 * mutex_lock_nested(whole->bd_mutex, 1)
1107 static int __blkdev_get(struct block_device
*bdev
, fmode_t mode
, int for_part
)
1109 struct gendisk
*disk
;
1110 struct module
*owner
;
1115 if (mode
& FMODE_READ
)
1117 if (mode
& FMODE_WRITE
)
1120 * hooks: /n/, see "layering violations".
1123 ret
= devcgroup_inode_permission(bdev
->bd_inode
, perm
);
1133 disk
= get_gendisk(bdev
->bd_dev
, &partno
);
1136 owner
= disk
->fops
->owner
;
1138 disk_block_events(disk
);
1139 mutex_lock_nested(&bdev
->bd_mutex
, for_part
);
1140 if (!bdev
->bd_openers
) {
1141 bdev
->bd_disk
= disk
;
1142 bdev
->bd_queue
= disk
->queue
;
1143 bdev
->bd_contains
= bdev
;
1145 struct backing_dev_info
*bdi
;
1148 bdev
->bd_part
= disk_get_part(disk
, partno
);
1153 if (disk
->fops
->open
) {
1154 ret
= disk
->fops
->open(bdev
, mode
);
1155 if (ret
== -ERESTARTSYS
) {
1156 /* Lost a race with 'disk' being
1157 * deleted, try again.
1160 disk_put_part(bdev
->bd_part
);
1161 bdev
->bd_part
= NULL
;
1162 bdev
->bd_disk
= NULL
;
1163 bdev
->bd_queue
= NULL
;
1164 mutex_unlock(&bdev
->bd_mutex
);
1165 disk_unblock_events(disk
);
1172 if (!ret
&& !bdev
->bd_openers
) {
1173 bd_set_size(bdev
,(loff_t
)get_capacity(disk
)<<9);
1174 bdi
= blk_get_backing_dev_info(bdev
);
1176 bdi
= &default_backing_dev_info
;
1177 bdev_inode_switch_bdi(bdev
->bd_inode
, bdi
);
1181 * If the device is invalidated, rescan partition
1182 * if open succeeded or failed with -ENOMEDIUM.
1183 * The latter is necessary to prevent ghost
1184 * partitions on a removed medium.
1186 if (bdev
->bd_invalidated
) {
1188 rescan_partitions(disk
, bdev
);
1189 else if (ret
== -ENOMEDIUM
)
1190 invalidate_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
) {
1223 rescan_partitions(bdev
->bd_disk
, bdev
);
1224 else if (ret
== -ENOMEDIUM
)
1225 invalidate_partitions(bdev
->bd_disk
, bdev
);
1228 goto out_unlock_bdev
;
1230 /* only one opener holds refs to the module and disk */
1236 bdev
->bd_part_count
++;
1237 mutex_unlock(&bdev
->bd_mutex
);
1238 disk_unblock_events(disk
);
1242 disk_put_part(bdev
->bd_part
);
1243 bdev
->bd_disk
= NULL
;
1244 bdev
->bd_part
= NULL
;
1245 bdev
->bd_queue
= NULL
;
1246 bdev_inode_switch_bdi(bdev
->bd_inode
, &default_backing_dev_info
);
1247 if (bdev
!= bdev
->bd_contains
)
1248 __blkdev_put(bdev
->bd_contains
, mode
, 1);
1249 bdev
->bd_contains
= NULL
;
1251 mutex_unlock(&bdev
->bd_mutex
);
1252 disk_unblock_events(disk
);
1262 * blkdev_get - open a block device
1263 * @bdev: block_device to open
1264 * @mode: FMODE_* mask
1265 * @holder: exclusive holder identifier
1267 * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is
1268 * open with exclusive access. Specifying %FMODE_EXCL with %NULL
1269 * @holder is invalid. Exclusive opens may nest for the same @holder.
1271 * On success, the reference count of @bdev is unchanged. On failure,
1278 * 0 on success, -errno on failure.
1280 int blkdev_get(struct block_device
*bdev
, fmode_t mode
, void *holder
)
1282 struct block_device
*whole
= NULL
;
1285 WARN_ON_ONCE((mode
& FMODE_EXCL
) && !holder
);
1287 if ((mode
& FMODE_EXCL
) && holder
) {
1288 whole
= bd_start_claiming(bdev
, holder
);
1289 if (IS_ERR(whole
)) {
1291 return PTR_ERR(whole
);
1295 res
= __blkdev_get(bdev
, mode
, 0);
1298 struct gendisk
*disk
= whole
->bd_disk
;
1300 /* finish claiming */
1301 mutex_lock(&bdev
->bd_mutex
);
1302 spin_lock(&bdev_lock
);
1305 BUG_ON(!bd_may_claim(bdev
, whole
, holder
));
1307 * Note that for a whole device bd_holders
1308 * will be incremented twice, and bd_holder
1309 * will be set to bd_may_claim before being
1312 whole
->bd_holders
++;
1313 whole
->bd_holder
= bd_may_claim
;
1315 bdev
->bd_holder
= holder
;
1318 /* tell others that we're done */
1319 BUG_ON(whole
->bd_claiming
!= holder
);
1320 whole
->bd_claiming
= NULL
;
1321 wake_up_bit(&whole
->bd_claiming
, 0);
1323 spin_unlock(&bdev_lock
);
1326 * Block event polling for write claims if requested. Any
1327 * write holder makes the write_holder state stick until
1328 * all are released. This is good enough and tracking
1329 * individual writeable reference is too fragile given the
1330 * way @mode is used in blkdev_get/put().
1332 if (!res
&& (mode
& FMODE_WRITE
) && !bdev
->bd_write_holder
&&
1333 (disk
->flags
& GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE
)) {
1334 bdev
->bd_write_holder
= true;
1335 disk_block_events(disk
);
1338 mutex_unlock(&bdev
->bd_mutex
);
1344 EXPORT_SYMBOL(blkdev_get
);
1347 * blkdev_get_by_path - open a block device by name
1348 * @path: path to the block device to open
1349 * @mode: FMODE_* mask
1350 * @holder: exclusive holder identifier
1352 * Open the blockdevice described by the device file at @path. @mode
1353 * and @holder are identical to blkdev_get().
1355 * On success, the returned block_device has reference count of one.
1361 * Pointer to block_device on success, ERR_PTR(-errno) on failure.
1363 struct block_device
*blkdev_get_by_path(const char *path
, fmode_t mode
,
1366 struct block_device
*bdev
;
1369 bdev
= lookup_bdev(path
);
1373 err
= blkdev_get(bdev
, mode
, holder
);
1375 return ERR_PTR(err
);
1377 if ((mode
& FMODE_WRITE
) && bdev_read_only(bdev
)) {
1378 blkdev_put(bdev
, mode
);
1379 return ERR_PTR(-EACCES
);
1384 EXPORT_SYMBOL(blkdev_get_by_path
);
1387 * blkdev_get_by_dev - open a block device by device number
1388 * @dev: device number of block device to open
1389 * @mode: FMODE_* mask
1390 * @holder: exclusive holder identifier
1392 * Open the blockdevice described by device number @dev. @mode and
1393 * @holder are identical to blkdev_get().
1395 * Use it ONLY if you really do not have anything better - i.e. when
1396 * you are behind a truly sucky interface and all you are given is a
1397 * device number. _Never_ to be used for internal purposes. If you
1398 * ever need it - reconsider your API.
1400 * On success, the returned block_device has reference count of one.
1406 * Pointer to block_device on success, ERR_PTR(-errno) on failure.
1408 struct block_device
*blkdev_get_by_dev(dev_t dev
, fmode_t mode
, void *holder
)
1410 struct block_device
*bdev
;
1415 return ERR_PTR(-ENOMEM
);
1417 err
= blkdev_get(bdev
, mode
, holder
);
1419 return ERR_PTR(err
);
1423 EXPORT_SYMBOL(blkdev_get_by_dev
);
1425 static int blkdev_open(struct inode
* inode
, struct file
* filp
)
1427 struct block_device
*bdev
;
1430 * Preserve backwards compatibility and allow large file access
1431 * even if userspace doesn't ask for it explicitly. Some mkfs
1432 * binary needs it. We might want to drop this workaround
1433 * during an unstable branch.
1435 filp
->f_flags
|= O_LARGEFILE
;
1437 if (filp
->f_flags
& O_NDELAY
)
1438 filp
->f_mode
|= FMODE_NDELAY
;
1439 if (filp
->f_flags
& O_EXCL
)
1440 filp
->f_mode
|= FMODE_EXCL
;
1441 if ((filp
->f_flags
& O_ACCMODE
) == 3)
1442 filp
->f_mode
|= FMODE_WRITE_IOCTL
;
1444 bdev
= bd_acquire(inode
);
1448 filp
->f_mapping
= bdev
->bd_inode
->i_mapping
;
1450 return blkdev_get(bdev
, filp
->f_mode
, filp
);
1453 static int __blkdev_put(struct block_device
*bdev
, fmode_t mode
, int for_part
)
1456 struct gendisk
*disk
= bdev
->bd_disk
;
1457 struct block_device
*victim
= NULL
;
1459 mutex_lock_nested(&bdev
->bd_mutex
, for_part
);
1461 bdev
->bd_part_count
--;
1463 if (!--bdev
->bd_openers
) {
1464 WARN_ON_ONCE(bdev
->bd_holders
);
1465 sync_blockdev(bdev
);
1467 /* ->release can cause the old bdi to disappear,
1468 * so must switch it out first
1470 bdev_inode_switch_bdi(bdev
->bd_inode
,
1471 &default_backing_dev_info
);
1473 if (bdev
->bd_contains
== bdev
) {
1474 if (disk
->fops
->release
)
1475 ret
= disk
->fops
->release(disk
, mode
);
1477 if (!bdev
->bd_openers
) {
1478 struct module
*owner
= disk
->fops
->owner
;
1480 disk_put_part(bdev
->bd_part
);
1481 bdev
->bd_part
= NULL
;
1482 bdev
->bd_disk
= NULL
;
1483 if (bdev
!= bdev
->bd_contains
)
1484 victim
= bdev
->bd_contains
;
1485 bdev
->bd_contains
= NULL
;
1490 mutex_unlock(&bdev
->bd_mutex
);
1493 __blkdev_put(victim
, mode
, 1);
1497 int blkdev_put(struct block_device
*bdev
, fmode_t mode
)
1499 mutex_lock(&bdev
->bd_mutex
);
1501 if (mode
& FMODE_EXCL
) {
1505 * Release a claim on the device. The holder fields
1506 * are protected with bdev_lock. bd_mutex is to
1507 * synchronize disk_holder unlinking.
1509 spin_lock(&bdev_lock
);
1511 WARN_ON_ONCE(--bdev
->bd_holders
< 0);
1512 WARN_ON_ONCE(--bdev
->bd_contains
->bd_holders
< 0);
1514 /* bd_contains might point to self, check in a separate step */
1515 if ((bdev_free
= !bdev
->bd_holders
))
1516 bdev
->bd_holder
= NULL
;
1517 if (!bdev
->bd_contains
->bd_holders
)
1518 bdev
->bd_contains
->bd_holder
= NULL
;
1520 spin_unlock(&bdev_lock
);
1523 * If this was the last claim, remove holder link and
1524 * unblock evpoll if it was a write holder.
1526 if (bdev_free
&& bdev
->bd_write_holder
) {
1527 disk_unblock_events(bdev
->bd_disk
);
1528 bdev
->bd_write_holder
= false;
1533 * Trigger event checking and tell drivers to flush MEDIA_CHANGE
1534 * event. This is to ensure detection of media removal commanded
1535 * from userland - e.g. eject(1).
1537 disk_flush_events(bdev
->bd_disk
, DISK_EVENT_MEDIA_CHANGE
);
1539 mutex_unlock(&bdev
->bd_mutex
);
1541 return __blkdev_put(bdev
, mode
, 0);
1543 EXPORT_SYMBOL(blkdev_put
);
1545 static int blkdev_close(struct inode
* inode
, struct file
* filp
)
1547 struct block_device
*bdev
= I_BDEV(filp
->f_mapping
->host
);
1549 return blkdev_put(bdev
, filp
->f_mode
);
1552 static long block_ioctl(struct file
*file
, unsigned cmd
, unsigned long arg
)
1554 struct block_device
*bdev
= I_BDEV(file
->f_mapping
->host
);
1555 fmode_t mode
= file
->f_mode
;
1558 * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
1559 * to updated it before every ioctl.
1561 if (file
->f_flags
& O_NDELAY
)
1562 mode
|= FMODE_NDELAY
;
1564 mode
&= ~FMODE_NDELAY
;
1566 return blkdev_ioctl(bdev
, mode
, cmd
, arg
);
1570 * Write data to the block device. Only intended for the block device itself
1571 * and the raw driver which basically is a fake block device.
1573 * Does not take i_mutex for the write and thus is not for general purpose
1576 ssize_t
blkdev_aio_write(struct kiocb
*iocb
, const struct iovec
*iov
,
1577 unsigned long nr_segs
, loff_t pos
)
1579 struct file
*file
= iocb
->ki_filp
;
1582 BUG_ON(iocb
->ki_pos
!= pos
);
1584 ret
= __generic_file_aio_write(iocb
, iov
, nr_segs
, &iocb
->ki_pos
);
1585 if (ret
> 0 || ret
== -EIOCBQUEUED
) {
1588 err
= generic_write_sync(file
, pos
, ret
);
1589 if (err
< 0 && ret
> 0)
1594 EXPORT_SYMBOL_GPL(blkdev_aio_write
);
1597 * Try to release a page associated with block device when the system
1598 * is under memory pressure.
1600 static int blkdev_releasepage(struct page
*page
, gfp_t wait
)
1602 struct super_block
*super
= BDEV_I(page
->mapping
->host
)->bdev
.bd_super
;
1604 if (super
&& super
->s_op
->bdev_try_to_free_page
)
1605 return super
->s_op
->bdev_try_to_free_page(super
, page
, wait
);
1607 return try_to_free_buffers(page
);
1610 static const struct address_space_operations def_blk_aops
= {
1611 .readpage
= blkdev_readpage
,
1612 .writepage
= blkdev_writepage
,
1613 .write_begin
= blkdev_write_begin
,
1614 .write_end
= blkdev_write_end
,
1615 .writepages
= generic_writepages
,
1616 .releasepage
= blkdev_releasepage
,
1617 .direct_IO
= blkdev_direct_IO
,
1620 const struct file_operations def_blk_fops
= {
1621 .open
= blkdev_open
,
1622 .release
= blkdev_close
,
1623 .llseek
= block_llseek
,
1624 .read
= do_sync_read
,
1625 .write
= do_sync_write
,
1626 .aio_read
= generic_file_aio_read
,
1627 .aio_write
= blkdev_aio_write
,
1628 .mmap
= generic_file_mmap
,
1629 .fsync
= blkdev_fsync
,
1630 .unlocked_ioctl
= block_ioctl
,
1631 #ifdef CONFIG_COMPAT
1632 .compat_ioctl
= compat_blkdev_ioctl
,
1634 .splice_read
= generic_file_splice_read
,
1635 .splice_write
= generic_file_splice_write
,
1638 int ioctl_by_bdev(struct block_device
*bdev
, unsigned cmd
, unsigned long arg
)
1641 mm_segment_t old_fs
= get_fs();
1643 res
= blkdev_ioctl(bdev
, 0, cmd
, arg
);
1648 EXPORT_SYMBOL(ioctl_by_bdev
);
1651 * lookup_bdev - lookup a struct block_device by name
1652 * @pathname: special file representing the block device
1654 * Get a reference to the blockdevice at @pathname in the current
1655 * namespace if possible and return it. Return ERR_PTR(error)
1658 struct block_device
*lookup_bdev(const char *pathname
)
1660 struct block_device
*bdev
;
1661 struct inode
*inode
;
1665 if (!pathname
|| !*pathname
)
1666 return ERR_PTR(-EINVAL
);
1668 error
= kern_path(pathname
, LOOKUP_FOLLOW
, &path
);
1670 return ERR_PTR(error
);
1672 inode
= path
.dentry
->d_inode
;
1674 if (!S_ISBLK(inode
->i_mode
))
1677 if (path
.mnt
->mnt_flags
& MNT_NODEV
)
1680 bdev
= bd_acquire(inode
);
1687 bdev
= ERR_PTR(error
);
1690 EXPORT_SYMBOL(lookup_bdev
);
1692 int __invalidate_device(struct block_device
*bdev
, bool kill_dirty
)
1694 struct super_block
*sb
= get_super(bdev
);
1699 * no need to lock the super, get_super holds the
1700 * read mutex so the filesystem cannot go away
1701 * under us (->put_super runs with the write lock
1704 shrink_dcache_sb(sb
);
1705 res
= invalidate_inodes(sb
, kill_dirty
);
1708 invalidate_bdev(bdev
);
1711 EXPORT_SYMBOL(__invalidate_device
);