4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
8 #include <linux/init.h>
10 #include <linux/fcntl.h>
11 #include <linux/slab.h>
12 #include <linux/kmod.h>
13 #include <linux/major.h>
14 #include <linux/smp_lock.h>
15 #include <linux/device_cgroup.h>
16 #include <linux/highmem.h>
17 #include <linux/blkdev.h>
18 #include <linux/module.h>
19 #include <linux/blkpg.h>
20 #include <linux/buffer_head.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 <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
;
49 EXPORT_SYMBOL(I_BDEV
);
51 static sector_t
max_block(struct block_device
*bdev
)
53 sector_t retval
= ~((sector_t
)0);
54 loff_t sz
= i_size_read(bdev
->bd_inode
);
57 unsigned int size
= block_size(bdev
);
58 unsigned int sizebits
= blksize_bits(size
);
59 retval
= (sz
>> sizebits
);
64 /* Kill _all_ buffers and pagecache , dirty or not.. */
65 static void kill_bdev(struct block_device
*bdev
)
67 if (bdev
->bd_inode
->i_mapping
->nrpages
== 0)
70 truncate_inode_pages(bdev
->bd_inode
->i_mapping
, 0);
73 int set_blocksize(struct block_device
*bdev
, int size
)
75 /* Size must be a power of two, and between 512 and PAGE_SIZE */
76 if (size
> PAGE_SIZE
|| size
< 512 || !is_power_of_2(size
))
79 /* Size cannot be smaller than the size supported by the device */
80 if (size
< bdev_logical_block_size(bdev
))
83 /* Don't change the size if it is same as current */
84 if (bdev
->bd_block_size
!= size
) {
86 bdev
->bd_block_size
= size
;
87 bdev
->bd_inode
->i_blkbits
= blksize_bits(size
);
93 EXPORT_SYMBOL(set_blocksize
);
95 int sb_set_blocksize(struct super_block
*sb
, int size
)
97 if (set_blocksize(sb
->s_bdev
, size
))
99 /* If we get here, we know size is power of two
100 * and it's value is between 512 and PAGE_SIZE */
101 sb
->s_blocksize
= size
;
102 sb
->s_blocksize_bits
= blksize_bits(size
);
103 return sb
->s_blocksize
;
106 EXPORT_SYMBOL(sb_set_blocksize
);
108 int sb_min_blocksize(struct super_block
*sb
, int size
)
110 int minsize
= bdev_logical_block_size(sb
->s_bdev
);
113 return sb_set_blocksize(sb
, size
);
116 EXPORT_SYMBOL(sb_min_blocksize
);
119 blkdev_get_block(struct inode
*inode
, sector_t iblock
,
120 struct buffer_head
*bh
, int create
)
122 if (iblock
>= max_block(I_BDEV(inode
))) {
127 * for reads, we're just trying to fill a partial page.
128 * return a hole, they will have to call get_block again
129 * before they can fill it, and they will get -EIO at that
134 bh
->b_bdev
= I_BDEV(inode
);
135 bh
->b_blocknr
= iblock
;
136 set_buffer_mapped(bh
);
141 blkdev_get_blocks(struct inode
*inode
, sector_t iblock
,
142 struct buffer_head
*bh
, int create
)
144 sector_t end_block
= max_block(I_BDEV(inode
));
145 unsigned long max_blocks
= bh
->b_size
>> inode
->i_blkbits
;
147 if ((iblock
+ max_blocks
) > end_block
) {
148 max_blocks
= end_block
- iblock
;
149 if ((long)max_blocks
<= 0) {
151 return -EIO
; /* write fully beyond EOF */
153 * It is a read which is fully beyond EOF. We return
154 * a !buffer_mapped buffer
160 bh
->b_bdev
= I_BDEV(inode
);
161 bh
->b_blocknr
= iblock
;
162 bh
->b_size
= max_blocks
<< inode
->i_blkbits
;
164 set_buffer_mapped(bh
);
169 blkdev_direct_IO(int rw
, struct kiocb
*iocb
, const struct iovec
*iov
,
170 loff_t offset
, unsigned long nr_segs
)
172 struct file
*file
= iocb
->ki_filp
;
173 struct inode
*inode
= file
->f_mapping
->host
;
175 return blockdev_direct_IO_no_locking(rw
, iocb
, inode
, I_BDEV(inode
),
176 iov
, offset
, nr_segs
, blkdev_get_blocks
, NULL
);
179 int __sync_blockdev(struct block_device
*bdev
, int wait
)
184 return filemap_flush(bdev
->bd_inode
->i_mapping
);
185 return filemap_write_and_wait(bdev
->bd_inode
->i_mapping
);
189 * Write out and wait upon all the dirty data associated with a block
190 * device via its mapping. Does not take the superblock lock.
192 int sync_blockdev(struct block_device
*bdev
)
194 return __sync_blockdev(bdev
, 1);
196 EXPORT_SYMBOL(sync_blockdev
);
199 * Write out and wait upon all dirty data associated with this
200 * device. Filesystem data as well as the underlying block
201 * device. Takes the superblock lock.
203 int fsync_bdev(struct block_device
*bdev
)
205 struct super_block
*sb
= get_super(bdev
);
207 int res
= sync_filesystem(sb
);
211 return sync_blockdev(bdev
);
213 EXPORT_SYMBOL(fsync_bdev
);
216 * freeze_bdev -- lock a filesystem and force it into a consistent state
217 * @bdev: blockdevice to lock
219 * If a superblock is found on this device, we take the s_umount semaphore
220 * on it to make sure nobody unmounts until the snapshot creation is done.
221 * The reference counter (bd_fsfreeze_count) guarantees that only the last
222 * unfreeze process can unfreeze the frozen filesystem actually when multiple
223 * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
224 * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
227 struct super_block
*freeze_bdev(struct block_device
*bdev
)
229 struct super_block
*sb
;
232 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
233 if (++bdev
->bd_fsfreeze_count
> 1) {
235 * We don't even need to grab a reference - the first call
236 * to freeze_bdev grab an active reference and only the last
237 * thaw_bdev drops it.
239 sb
= get_super(bdev
);
241 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
245 sb
= get_active_super(bdev
);
248 error
= freeze_super(sb
);
250 deactivate_super(sb
);
251 bdev
->bd_fsfreeze_count
--;
252 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
253 return ERR_PTR(error
);
255 deactivate_super(sb
);
258 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
259 return sb
; /* thaw_bdev releases s->s_umount */
261 EXPORT_SYMBOL(freeze_bdev
);
264 * thaw_bdev -- unlock filesystem
265 * @bdev: blockdevice to unlock
266 * @sb: associated superblock
268 * Unlocks the filesystem and marks it writeable again after freeze_bdev().
270 int thaw_bdev(struct block_device
*bdev
, struct super_block
*sb
)
274 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
275 if (!bdev
->bd_fsfreeze_count
)
279 if (--bdev
->bd_fsfreeze_count
> 0)
285 error
= thaw_super(sb
);
287 bdev
->bd_fsfreeze_count
++;
288 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
292 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
295 EXPORT_SYMBOL(thaw_bdev
);
297 static int blkdev_writepage(struct page
*page
, struct writeback_control
*wbc
)
299 return block_write_full_page(page
, blkdev_get_block
, wbc
);
302 static int blkdev_readpage(struct file
* file
, struct page
* page
)
304 return block_read_full_page(page
, blkdev_get_block
);
307 static int blkdev_write_begin(struct file
*file
, struct address_space
*mapping
,
308 loff_t pos
, unsigned len
, unsigned flags
,
309 struct page
**pagep
, void **fsdata
)
312 return block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
316 static int blkdev_write_end(struct file
*file
, struct address_space
*mapping
,
317 loff_t pos
, unsigned len
, unsigned copied
,
318 struct page
*page
, void *fsdata
)
321 ret
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
324 page_cache_release(page
);
331 * for a block special file file->f_path.dentry->d_inode->i_size is zero
332 * so we compute the size by hand (just as in block_read/write above)
334 static loff_t
block_llseek(struct file
*file
, loff_t offset
, int origin
)
336 struct inode
*bd_inode
= file
->f_mapping
->host
;
340 mutex_lock(&bd_inode
->i_mutex
);
341 size
= i_size_read(bd_inode
);
348 offset
+= file
->f_pos
;
351 if (offset
>= 0 && offset
<= size
) {
352 if (offset
!= file
->f_pos
) {
353 file
->f_pos
= offset
;
357 mutex_unlock(&bd_inode
->i_mutex
);
361 int blkdev_fsync(struct file
*filp
, int datasync
)
363 struct inode
*bd_inode
= filp
->f_mapping
->host
;
364 struct block_device
*bdev
= I_BDEV(bd_inode
);
368 * There is no need to serialise calls to blkdev_issue_flush with
369 * i_mutex and doing so causes performance issues with concurrent
370 * O_SYNC writers to a block device.
372 mutex_unlock(&bd_inode
->i_mutex
);
374 error
= blkdev_issue_flush(bdev
, GFP_KERNEL
, NULL
, BLKDEV_IFL_WAIT
);
375 if (error
== -EOPNOTSUPP
)
378 mutex_lock(&bd_inode
->i_mutex
);
382 EXPORT_SYMBOL(blkdev_fsync
);
388 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(bdev_lock
);
389 static struct kmem_cache
* bdev_cachep __read_mostly
;
391 static struct inode
*bdev_alloc_inode(struct super_block
*sb
)
393 struct bdev_inode
*ei
= kmem_cache_alloc(bdev_cachep
, GFP_KERNEL
);
396 return &ei
->vfs_inode
;
399 static void bdev_destroy_inode(struct inode
*inode
)
401 struct bdev_inode
*bdi
= BDEV_I(inode
);
403 kmem_cache_free(bdev_cachep
, bdi
);
406 static void init_once(void *foo
)
408 struct bdev_inode
*ei
= (struct bdev_inode
*) foo
;
409 struct block_device
*bdev
= &ei
->bdev
;
411 memset(bdev
, 0, sizeof(*bdev
));
412 mutex_init(&bdev
->bd_mutex
);
413 INIT_LIST_HEAD(&bdev
->bd_inodes
);
414 INIT_LIST_HEAD(&bdev
->bd_list
);
416 INIT_LIST_HEAD(&bdev
->bd_holder_list
);
418 inode_init_once(&ei
->vfs_inode
);
419 /* Initialize mutex for freeze. */
420 mutex_init(&bdev
->bd_fsfreeze_mutex
);
423 static inline void __bd_forget(struct inode
*inode
)
425 list_del_init(&inode
->i_devices
);
426 inode
->i_bdev
= NULL
;
427 inode
->i_mapping
= &inode
->i_data
;
430 static void bdev_clear_inode(struct inode
*inode
)
432 struct block_device
*bdev
= &BDEV_I(inode
)->bdev
;
434 spin_lock(&bdev_lock
);
435 while ( (p
= bdev
->bd_inodes
.next
) != &bdev
->bd_inodes
) {
436 __bd_forget(list_entry(p
, struct inode
, i_devices
));
438 list_del_init(&bdev
->bd_list
);
439 spin_unlock(&bdev_lock
);
442 static const struct super_operations bdev_sops
= {
443 .statfs
= simple_statfs
,
444 .alloc_inode
= bdev_alloc_inode
,
445 .destroy_inode
= bdev_destroy_inode
,
446 .drop_inode
= generic_delete_inode
,
447 .clear_inode
= bdev_clear_inode
,
450 static int bd_get_sb(struct file_system_type
*fs_type
,
451 int flags
, const char *dev_name
, void *data
, struct vfsmount
*mnt
)
453 return get_sb_pseudo(fs_type
, "bdev:", &bdev_sops
, 0x62646576, mnt
);
456 static struct file_system_type bd_type
= {
459 .kill_sb
= kill_anon_super
,
462 struct super_block
*blockdev_superblock __read_mostly
;
464 void __init
bdev_cache_init(void)
467 struct vfsmount
*bd_mnt
;
469 bdev_cachep
= kmem_cache_create("bdev_cache", sizeof(struct bdev_inode
),
470 0, (SLAB_HWCACHE_ALIGN
|SLAB_RECLAIM_ACCOUNT
|
471 SLAB_MEM_SPREAD
|SLAB_PANIC
),
473 err
= register_filesystem(&bd_type
);
475 panic("Cannot register bdev pseudo-fs");
476 bd_mnt
= kern_mount(&bd_type
);
478 panic("Cannot create bdev pseudo-fs");
480 * This vfsmount structure is only used to obtain the
481 * blockdev_superblock, so tell kmemleak not to report it.
483 kmemleak_not_leak(bd_mnt
);
484 blockdev_superblock
= bd_mnt
->mnt_sb
; /* For writeback */
488 * Most likely _very_ bad one - but then it's hardly critical for small
489 * /dev and can be fixed when somebody will need really large one.
490 * Keep in mind that it will be fed through icache hash function too.
492 static inline unsigned long hash(dev_t dev
)
494 return MAJOR(dev
)+MINOR(dev
);
497 static int bdev_test(struct inode
*inode
, void *data
)
499 return BDEV_I(inode
)->bdev
.bd_dev
== *(dev_t
*)data
;
502 static int bdev_set(struct inode
*inode
, void *data
)
504 BDEV_I(inode
)->bdev
.bd_dev
= *(dev_t
*)data
;
508 static LIST_HEAD(all_bdevs
);
510 struct block_device
*bdget(dev_t dev
)
512 struct block_device
*bdev
;
515 inode
= iget5_locked(blockdev_superblock
, hash(dev
),
516 bdev_test
, bdev_set
, &dev
);
521 bdev
= &BDEV_I(inode
)->bdev
;
523 if (inode
->i_state
& I_NEW
) {
524 bdev
->bd_contains
= NULL
;
525 bdev
->bd_inode
= inode
;
526 bdev
->bd_block_size
= (1 << inode
->i_blkbits
);
527 bdev
->bd_part_count
= 0;
528 bdev
->bd_invalidated
= 0;
529 inode
->i_mode
= S_IFBLK
;
531 inode
->i_bdev
= bdev
;
532 inode
->i_data
.a_ops
= &def_blk_aops
;
533 mapping_set_gfp_mask(&inode
->i_data
, GFP_USER
);
534 inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
535 spin_lock(&bdev_lock
);
536 list_add(&bdev
->bd_list
, &all_bdevs
);
537 spin_unlock(&bdev_lock
);
538 unlock_new_inode(inode
);
543 EXPORT_SYMBOL(bdget
);
546 * bdgrab -- Grab a reference to an already referenced block device
547 * @bdev: Block device to grab a reference to.
549 struct block_device
*bdgrab(struct block_device
*bdev
)
551 atomic_inc(&bdev
->bd_inode
->i_count
);
555 long nr_blockdev_pages(void)
557 struct block_device
*bdev
;
559 spin_lock(&bdev_lock
);
560 list_for_each_entry(bdev
, &all_bdevs
, bd_list
) {
561 ret
+= bdev
->bd_inode
->i_mapping
->nrpages
;
563 spin_unlock(&bdev_lock
);
567 void bdput(struct block_device
*bdev
)
569 iput(bdev
->bd_inode
);
572 EXPORT_SYMBOL(bdput
);
574 static struct block_device
*bd_acquire(struct inode
*inode
)
576 struct block_device
*bdev
;
578 spin_lock(&bdev_lock
);
579 bdev
= inode
->i_bdev
;
581 atomic_inc(&bdev
->bd_inode
->i_count
);
582 spin_unlock(&bdev_lock
);
585 spin_unlock(&bdev_lock
);
587 bdev
= bdget(inode
->i_rdev
);
589 spin_lock(&bdev_lock
);
590 if (!inode
->i_bdev
) {
592 * We take an additional bd_inode->i_count for inode,
593 * and it's released in clear_inode() of inode.
594 * So, we can access it via ->i_mapping always
597 atomic_inc(&bdev
->bd_inode
->i_count
);
598 inode
->i_bdev
= bdev
;
599 inode
->i_mapping
= bdev
->bd_inode
->i_mapping
;
600 list_add(&inode
->i_devices
, &bdev
->bd_inodes
);
602 spin_unlock(&bdev_lock
);
607 /* Call when you free inode */
609 void bd_forget(struct inode
*inode
)
611 struct block_device
*bdev
= NULL
;
613 spin_lock(&bdev_lock
);
615 if (!sb_is_blkdev_sb(inode
->i_sb
))
616 bdev
= inode
->i_bdev
;
619 spin_unlock(&bdev_lock
);
622 iput(bdev
->bd_inode
);
626 * bd_may_claim - test whether a block device can be claimed
627 * @bdev: block device of interest
628 * @whole: whole block device containing @bdev, may equal @bdev
629 * @holder: holder trying to claim @bdev
631 * Test whther @bdev can be claimed by @holder.
634 * spin_lock(&bdev_lock).
637 * %true if @bdev can be claimed, %false otherwise.
639 static bool bd_may_claim(struct block_device
*bdev
, struct block_device
*whole
,
642 if (bdev
->bd_holder
== holder
)
643 return true; /* already a holder */
644 else if (bdev
->bd_holder
!= NULL
)
645 return false; /* held by someone else */
646 else if (bdev
->bd_contains
== bdev
)
647 return true; /* is a whole device which isn't held */
649 else if (whole
->bd_holder
== bd_claim
)
650 return true; /* is a partition of a device that is being partitioned */
651 else if (whole
->bd_holder
!= NULL
)
652 return false; /* is a partition of a held device */
654 return true; /* is a partition of an un-held device */
658 * bd_prepare_to_claim - prepare to claim a block device
659 * @bdev: block device of interest
660 * @whole: the whole device containing @bdev, may equal @bdev
661 * @holder: holder trying to claim @bdev
663 * Prepare to claim @bdev. This function fails if @bdev is already
664 * claimed by another holder and waits if another claiming is in
665 * progress. This function doesn't actually claim. On successful
666 * return, the caller has ownership of bd_claiming and bd_holder[s].
669 * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab
673 * 0 if @bdev can be claimed, -EBUSY otherwise.
675 static int bd_prepare_to_claim(struct block_device
*bdev
,
676 struct block_device
*whole
, void *holder
)
679 /* if someone else claimed, fail */
680 if (!bd_may_claim(bdev
, whole
, holder
))
683 /* if someone else is claiming, wait for it to finish */
684 if (whole
->bd_claiming
&& whole
->bd_claiming
!= holder
) {
685 wait_queue_head_t
*wq
= bit_waitqueue(&whole
->bd_claiming
, 0);
688 prepare_to_wait(wq
, &wait
, TASK_UNINTERRUPTIBLE
);
689 spin_unlock(&bdev_lock
);
691 finish_wait(wq
, &wait
);
692 spin_lock(&bdev_lock
);
701 * bd_start_claiming - start claiming a block device
702 * @bdev: block device of interest
703 * @holder: holder trying to claim @bdev
705 * @bdev is about to be opened exclusively. Check @bdev can be opened
706 * exclusively and mark that an exclusive open is in progress. Each
707 * successful call to this function must be matched with a call to
708 * either bd_claim() or bd_abort_claiming(). If this function
709 * succeeds, the matching bd_claim() is guaranteed to succeed.
715 * Pointer to the block device containing @bdev on success, ERR_PTR()
718 static struct block_device
*bd_start_claiming(struct block_device
*bdev
,
721 struct gendisk
*disk
;
722 struct block_device
*whole
;
728 * @bdev might not have been initialized properly yet, look up
729 * and grab the outer block device the hard way.
731 disk
= get_gendisk(bdev
->bd_dev
, &partno
);
733 return ERR_PTR(-ENXIO
);
735 whole
= bdget_disk(disk
, 0);
738 return ERR_PTR(-ENOMEM
);
740 /* prepare to claim, if successful, mark claiming in progress */
741 spin_lock(&bdev_lock
);
743 err
= bd_prepare_to_claim(bdev
, whole
, holder
);
745 whole
->bd_claiming
= holder
;
746 spin_unlock(&bdev_lock
);
749 spin_unlock(&bdev_lock
);
755 /* releases bdev_lock */
756 static void __bd_abort_claiming(struct block_device
*whole
, void *holder
)
758 BUG_ON(whole
->bd_claiming
!= holder
);
759 whole
->bd_claiming
= NULL
;
760 wake_up_bit(&whole
->bd_claiming
, 0);
762 spin_unlock(&bdev_lock
);
767 * bd_abort_claiming - abort claiming a block device
768 * @whole: whole block device returned by bd_start_claiming()
769 * @holder: holder trying to claim @bdev
771 * Abort a claiming block started by bd_start_claiming(). Note that
772 * @whole is not the block device to be claimed but the whole device
773 * returned by bd_start_claiming().
776 * Grabs and releases bdev_lock.
778 static void bd_abort_claiming(struct block_device
*whole
, void *holder
)
780 spin_lock(&bdev_lock
);
781 __bd_abort_claiming(whole
, holder
); /* releases bdev_lock */
785 * bd_claim - claim a block device
786 * @bdev: block device to claim
787 * @holder: holder trying to claim @bdev
789 * Try to claim @bdev which must have been opened successfully. This
790 * function may be called with or without preceding
791 * blk_start_claiming(). In the former case, this function is always
792 * successful and terminates the claiming block.
798 * 0 if successful, -EBUSY if @bdev is already claimed.
800 int bd_claim(struct block_device
*bdev
, void *holder
)
802 struct block_device
*whole
= bdev
->bd_contains
;
807 spin_lock(&bdev_lock
);
809 res
= bd_prepare_to_claim(bdev
, whole
, holder
);
811 /* note that for a whole device bd_holders
812 * will be incremented twice, and bd_holder will
813 * be set to bd_claim before being set to holder
816 whole
->bd_holder
= bd_claim
;
818 bdev
->bd_holder
= holder
;
821 if (whole
->bd_claiming
)
822 __bd_abort_claiming(whole
, holder
); /* releases bdev_lock */
824 spin_unlock(&bdev_lock
);
828 EXPORT_SYMBOL(bd_claim
);
830 void bd_release(struct block_device
*bdev
)
832 spin_lock(&bdev_lock
);
833 if (!--bdev
->bd_contains
->bd_holders
)
834 bdev
->bd_contains
->bd_holder
= NULL
;
835 if (!--bdev
->bd_holders
)
836 bdev
->bd_holder
= NULL
;
837 spin_unlock(&bdev_lock
);
840 EXPORT_SYMBOL(bd_release
);
844 * Functions for bd_claim_by_kobject / bd_release_from_kobject
846 * If a kobject is passed to bd_claim_by_kobject()
847 * and the kobject has a parent directory,
848 * following symlinks are created:
849 * o from the kobject to the claimed bdev
850 * o from "holders" directory of the bdev to the parent of the kobject
851 * bd_release_from_kobject() removes these symlinks.
854 * If /dev/dm-0 maps to /dev/sda, kobject corresponding to
855 * /sys/block/dm-0/slaves is passed to bd_claim_by_kobject(), then:
856 * /sys/block/dm-0/slaves/sda --> /sys/block/sda
857 * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
860 static int add_symlink(struct kobject
*from
, struct kobject
*to
)
864 return sysfs_create_link(from
, to
, kobject_name(to
));
867 static void del_symlink(struct kobject
*from
, struct kobject
*to
)
871 sysfs_remove_link(from
, kobject_name(to
));
875 * 'struct bd_holder' contains pointers to kobjects symlinked by
876 * bd_claim_by_kobject.
877 * It's connected to bd_holder_list which is protected by bdev->bd_sem.
880 struct list_head list
; /* chain of holders of the bdev */
881 int count
; /* references from the holder */
882 struct kobject
*sdir
; /* holder object, e.g. "/block/dm-0/slaves" */
883 struct kobject
*hdev
; /* e.g. "/block/dm-0" */
884 struct kobject
*hdir
; /* e.g. "/block/sda/holders" */
885 struct kobject
*sdev
; /* e.g. "/block/sda" */
889 * Get references of related kobjects at once.
890 * Returns 1 on success. 0 on failure.
892 * Should call bd_holder_release_dirs() after successful use.
894 static int bd_holder_grab_dirs(struct block_device
*bdev
,
895 struct bd_holder
*bo
)
900 bo
->sdir
= kobject_get(bo
->sdir
);
904 bo
->hdev
= kobject_get(bo
->sdir
->parent
);
908 bo
->sdev
= kobject_get(&part_to_dev(bdev
->bd_part
)->kobj
);
912 bo
->hdir
= kobject_get(bdev
->bd_part
->holder_dir
);
919 kobject_put(bo
->sdev
);
921 kobject_put(bo
->hdev
);
923 kobject_put(bo
->sdir
);
928 /* Put references of related kobjects at once. */
929 static void bd_holder_release_dirs(struct bd_holder
*bo
)
931 kobject_put(bo
->hdir
);
932 kobject_put(bo
->sdev
);
933 kobject_put(bo
->hdev
);
934 kobject_put(bo
->sdir
);
937 static struct bd_holder
*alloc_bd_holder(struct kobject
*kobj
)
939 struct bd_holder
*bo
;
941 bo
= kzalloc(sizeof(*bo
), GFP_KERNEL
);
951 static void free_bd_holder(struct bd_holder
*bo
)
957 * find_bd_holder - find matching struct bd_holder from the block device
959 * @bdev: struct block device to be searched
960 * @bo: target struct bd_holder
962 * Returns matching entry with @bo in @bdev->bd_holder_list.
963 * If found, increment the reference count and return the pointer.
964 * If not found, returns NULL.
966 static struct bd_holder
*find_bd_holder(struct block_device
*bdev
,
967 struct bd_holder
*bo
)
969 struct bd_holder
*tmp
;
971 list_for_each_entry(tmp
, &bdev
->bd_holder_list
, list
)
972 if (tmp
->sdir
== bo
->sdir
) {
981 * add_bd_holder - create sysfs symlinks for bd_claim() relationship
983 * @bdev: block device to be bd_claimed
984 * @bo: preallocated and initialized by alloc_bd_holder()
986 * Add @bo to @bdev->bd_holder_list, create symlinks.
988 * Returns 0 if symlinks are created.
989 * Returns -ve if something fails.
991 static int add_bd_holder(struct block_device
*bdev
, struct bd_holder
*bo
)
998 if (!bd_holder_grab_dirs(bdev
, bo
))
1001 err
= add_symlink(bo
->sdir
, bo
->sdev
);
1005 err
= add_symlink(bo
->hdir
, bo
->hdev
);
1007 del_symlink(bo
->sdir
, bo
->sdev
);
1011 list_add_tail(&bo
->list
, &bdev
->bd_holder_list
);
1016 * del_bd_holder - delete sysfs symlinks for bd_claim() relationship
1018 * @bdev: block device to be bd_claimed
1019 * @kobj: holder's kobject
1021 * If there is matching entry with @kobj in @bdev->bd_holder_list
1022 * and no other bd_claim() from the same kobject,
1023 * remove the struct bd_holder from the list, delete symlinks for it.
1025 * Returns a pointer to the struct bd_holder when it's removed from the list
1026 * and ready to be freed.
1027 * Returns NULL if matching claim isn't found or there is other bd_claim()
1028 * by the same kobject.
1030 static struct bd_holder
*del_bd_holder(struct block_device
*bdev
,
1031 struct kobject
*kobj
)
1033 struct bd_holder
*bo
;
1035 list_for_each_entry(bo
, &bdev
->bd_holder_list
, list
) {
1036 if (bo
->sdir
== kobj
) {
1038 BUG_ON(bo
->count
< 0);
1040 list_del(&bo
->list
);
1041 del_symlink(bo
->sdir
, bo
->sdev
);
1042 del_symlink(bo
->hdir
, bo
->hdev
);
1043 bd_holder_release_dirs(bo
);
1054 * bd_claim_by_kobject - bd_claim() with additional kobject signature
1056 * @bdev: block device to be claimed
1057 * @holder: holder's signature
1058 * @kobj: holder's kobject
1060 * Do bd_claim() and if it succeeds, create sysfs symlinks between
1061 * the bdev and the holder's kobject.
1062 * Use bd_release_from_kobject() when relesing the claimed bdev.
1064 * Returns 0 on success. (same as bd_claim())
1065 * Returns errno on failure.
1067 static int bd_claim_by_kobject(struct block_device
*bdev
, void *holder
,
1068 struct kobject
*kobj
)
1071 struct bd_holder
*bo
, *found
;
1076 bo
= alloc_bd_holder(kobj
);
1080 mutex_lock(&bdev
->bd_mutex
);
1082 err
= bd_claim(bdev
, holder
);
1086 found
= find_bd_holder(bdev
, bo
);
1090 err
= add_bd_holder(bdev
, bo
);
1096 mutex_unlock(&bdev
->bd_mutex
);
1102 * bd_release_from_kobject - bd_release() with additional kobject signature
1104 * @bdev: block device to be released
1105 * @kobj: holder's kobject
1107 * Do bd_release() and remove sysfs symlinks created by bd_claim_by_kobject().
1109 static void bd_release_from_kobject(struct block_device
*bdev
,
1110 struct kobject
*kobj
)
1115 mutex_lock(&bdev
->bd_mutex
);
1117 free_bd_holder(del_bd_holder(bdev
, kobj
));
1118 mutex_unlock(&bdev
->bd_mutex
);
1122 * bd_claim_by_disk - wrapper function for bd_claim_by_kobject()
1124 * @bdev: block device to be claimed
1125 * @holder: holder's signature
1126 * @disk: holder's gendisk
1128 * Call bd_claim_by_kobject() with getting @disk->slave_dir.
1130 int bd_claim_by_disk(struct block_device
*bdev
, void *holder
,
1131 struct gendisk
*disk
)
1133 return bd_claim_by_kobject(bdev
, holder
, kobject_get(disk
->slave_dir
));
1135 EXPORT_SYMBOL_GPL(bd_claim_by_disk
);
1138 * bd_release_from_disk - wrapper function for bd_release_from_kobject()
1140 * @bdev: block device to be claimed
1141 * @disk: holder's gendisk
1143 * Call bd_release_from_kobject() and put @disk->slave_dir.
1145 void bd_release_from_disk(struct block_device
*bdev
, struct gendisk
*disk
)
1147 bd_release_from_kobject(bdev
, disk
->slave_dir
);
1148 kobject_put(disk
->slave_dir
);
1150 EXPORT_SYMBOL_GPL(bd_release_from_disk
);
1154 * Tries to open block device by device number. Use it ONLY if you
1155 * really do not have anything better - i.e. when you are behind a
1156 * truly sucky interface and all you are given is a device number. _Never_
1157 * to be used for internal purposes. If you ever need it - reconsider
1160 struct block_device
*open_by_devnum(dev_t dev
, fmode_t mode
)
1162 struct block_device
*bdev
= bdget(dev
);
1165 err
= blkdev_get(bdev
, mode
);
1166 return err
? ERR_PTR(err
) : bdev
;
1169 EXPORT_SYMBOL(open_by_devnum
);
1172 * flush_disk - invalidates all buffer-cache entries on a disk
1174 * @bdev: struct block device to be flushed
1176 * Invalidates all buffer-cache entries on a disk. It should be called
1177 * when a disk has been changed -- either by a media change or online
1180 static void flush_disk(struct block_device
*bdev
)
1182 if (__invalidate_device(bdev
)) {
1183 char name
[BDEVNAME_SIZE
] = "";
1186 disk_name(bdev
->bd_disk
, 0, name
);
1187 printk(KERN_WARNING
"VFS: busy inodes on changed media or "
1188 "resized disk %s\n", name
);
1193 if (disk_partitionable(bdev
->bd_disk
))
1194 bdev
->bd_invalidated
= 1;
1198 * check_disk_size_change - checks for disk size change and adjusts bdev size.
1199 * @disk: struct gendisk to check
1200 * @bdev: struct bdev to adjust.
1202 * This routine checks to see if the bdev size does not match the disk size
1203 * and adjusts it if it differs.
1205 void check_disk_size_change(struct gendisk
*disk
, struct block_device
*bdev
)
1207 loff_t disk_size
, bdev_size
;
1209 disk_size
= (loff_t
)get_capacity(disk
) << 9;
1210 bdev_size
= i_size_read(bdev
->bd_inode
);
1211 if (disk_size
!= bdev_size
) {
1212 char name
[BDEVNAME_SIZE
];
1214 disk_name(disk
, 0, name
);
1216 "%s: detected capacity change from %lld to %lld\n",
1217 name
, bdev_size
, disk_size
);
1218 i_size_write(bdev
->bd_inode
, disk_size
);
1222 EXPORT_SYMBOL(check_disk_size_change
);
1225 * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back
1226 * @disk: struct gendisk to be revalidated
1228 * This routine is a wrapper for lower-level driver's revalidate_disk
1229 * call-backs. It is used to do common pre and post operations needed
1230 * for all revalidate_disk operations.
1232 int revalidate_disk(struct gendisk
*disk
)
1234 struct block_device
*bdev
;
1237 if (disk
->fops
->revalidate_disk
)
1238 ret
= disk
->fops
->revalidate_disk(disk
);
1240 bdev
= bdget_disk(disk
, 0);
1244 mutex_lock(&bdev
->bd_mutex
);
1245 check_disk_size_change(disk
, bdev
);
1246 mutex_unlock(&bdev
->bd_mutex
);
1250 EXPORT_SYMBOL(revalidate_disk
);
1253 * This routine checks whether a removable media has been changed,
1254 * and invalidates all buffer-cache-entries in that case. This
1255 * is a relatively slow routine, so we have to try to minimize using
1256 * it. Thus it is called only upon a 'mount' or 'open'. This
1257 * is the best way of combining speed and utility, I think.
1258 * People changing diskettes in the middle of an operation deserve
1261 int check_disk_change(struct block_device
*bdev
)
1263 struct gendisk
*disk
= bdev
->bd_disk
;
1264 const struct block_device_operations
*bdops
= disk
->fops
;
1266 if (!bdops
->media_changed
)
1268 if (!bdops
->media_changed(bdev
->bd_disk
))
1272 if (bdops
->revalidate_disk
)
1273 bdops
->revalidate_disk(bdev
->bd_disk
);
1277 EXPORT_SYMBOL(check_disk_change
);
1279 void bd_set_size(struct block_device
*bdev
, loff_t size
)
1281 unsigned bsize
= bdev_logical_block_size(bdev
);
1283 bdev
->bd_inode
->i_size
= size
;
1284 while (bsize
< PAGE_CACHE_SIZE
) {
1289 bdev
->bd_block_size
= bsize
;
1290 bdev
->bd_inode
->i_blkbits
= blksize_bits(bsize
);
1292 EXPORT_SYMBOL(bd_set_size
);
1294 static int __blkdev_put(struct block_device
*bdev
, fmode_t mode
, int for_part
);
1299 * mutex_lock(part->bd_mutex)
1300 * mutex_lock_nested(whole->bd_mutex, 1)
1303 static int __blkdev_get(struct block_device
*bdev
, fmode_t mode
, int for_part
)
1305 struct gendisk
*disk
;
1310 if (mode
& FMODE_READ
)
1312 if (mode
& FMODE_WRITE
)
1315 * hooks: /n/, see "layering violations".
1317 ret
= devcgroup_inode_permission(bdev
->bd_inode
, perm
);
1327 disk
= get_gendisk(bdev
->bd_dev
, &partno
);
1329 goto out_unlock_kernel
;
1331 mutex_lock_nested(&bdev
->bd_mutex
, for_part
);
1332 if (!bdev
->bd_openers
) {
1333 bdev
->bd_disk
= disk
;
1334 bdev
->bd_contains
= bdev
;
1336 struct backing_dev_info
*bdi
;
1339 bdev
->bd_part
= disk_get_part(disk
, partno
);
1343 if (disk
->fops
->open
) {
1344 ret
= disk
->fops
->open(bdev
, mode
);
1345 if (ret
== -ERESTARTSYS
) {
1346 /* Lost a race with 'disk' being
1347 * deleted, try again.
1350 disk_put_part(bdev
->bd_part
);
1351 bdev
->bd_part
= NULL
;
1352 module_put(disk
->fops
->owner
);
1354 bdev
->bd_disk
= NULL
;
1355 mutex_unlock(&bdev
->bd_mutex
);
1361 if (!bdev
->bd_openers
) {
1362 bd_set_size(bdev
,(loff_t
)get_capacity(disk
)<<9);
1363 bdi
= blk_get_backing_dev_info(bdev
);
1365 bdi
= &default_backing_dev_info
;
1366 bdev
->bd_inode
->i_data
.backing_dev_info
= bdi
;
1368 if (bdev
->bd_invalidated
)
1369 rescan_partitions(disk
, bdev
);
1371 struct block_device
*whole
;
1372 whole
= bdget_disk(disk
, 0);
1377 ret
= __blkdev_get(whole
, mode
, 1);
1380 bdev
->bd_contains
= whole
;
1381 bdev
->bd_inode
->i_data
.backing_dev_info
=
1382 whole
->bd_inode
->i_data
.backing_dev_info
;
1383 bdev
->bd_part
= disk_get_part(disk
, partno
);
1384 if (!(disk
->flags
& GENHD_FL_UP
) ||
1385 !bdev
->bd_part
|| !bdev
->bd_part
->nr_sects
) {
1389 bd_set_size(bdev
, (loff_t
)bdev
->bd_part
->nr_sects
<< 9);
1392 module_put(disk
->fops
->owner
);
1395 if (bdev
->bd_contains
== bdev
) {
1396 if (bdev
->bd_disk
->fops
->open
) {
1397 ret
= bdev
->bd_disk
->fops
->open(bdev
, mode
);
1399 goto out_unlock_bdev
;
1401 if (bdev
->bd_invalidated
)
1402 rescan_partitions(bdev
->bd_disk
, bdev
);
1407 bdev
->bd_part_count
++;
1408 mutex_unlock(&bdev
->bd_mutex
);
1413 disk_put_part(bdev
->bd_part
);
1414 bdev
->bd_disk
= NULL
;
1415 bdev
->bd_part
= NULL
;
1416 bdev
->bd_inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
1417 if (bdev
!= bdev
->bd_contains
)
1418 __blkdev_put(bdev
->bd_contains
, mode
, 1);
1419 bdev
->bd_contains
= NULL
;
1421 mutex_unlock(&bdev
->bd_mutex
);
1426 module_put(disk
->fops
->owner
);
1433 int blkdev_get(struct block_device
*bdev
, fmode_t mode
)
1435 return __blkdev_get(bdev
, mode
, 0);
1437 EXPORT_SYMBOL(blkdev_get
);
1439 static int blkdev_open(struct inode
* inode
, struct file
* filp
)
1441 struct block_device
*whole
= NULL
;
1442 struct block_device
*bdev
;
1446 * Preserve backwards compatibility and allow large file access
1447 * even if userspace doesn't ask for it explicitly. Some mkfs
1448 * binary needs it. We might want to drop this workaround
1449 * during an unstable branch.
1451 filp
->f_flags
|= O_LARGEFILE
;
1453 if (filp
->f_flags
& O_NDELAY
)
1454 filp
->f_mode
|= FMODE_NDELAY
;
1455 if (filp
->f_flags
& O_EXCL
)
1456 filp
->f_mode
|= FMODE_EXCL
;
1457 if ((filp
->f_flags
& O_ACCMODE
) == 3)
1458 filp
->f_mode
|= FMODE_WRITE_IOCTL
;
1460 bdev
= bd_acquire(inode
);
1464 if (filp
->f_mode
& FMODE_EXCL
) {
1465 whole
= bd_start_claiming(bdev
, filp
);
1466 if (IS_ERR(whole
)) {
1468 return PTR_ERR(whole
);
1472 filp
->f_mapping
= bdev
->bd_inode
->i_mapping
;
1474 res
= blkdev_get(bdev
, filp
->f_mode
);
1478 BUG_ON(bd_claim(bdev
, filp
) != 0);
1480 bd_abort_claiming(whole
, filp
);
1486 static int __blkdev_put(struct block_device
*bdev
, fmode_t mode
, int for_part
)
1489 struct gendisk
*disk
= bdev
->bd_disk
;
1490 struct block_device
*victim
= NULL
;
1492 mutex_lock_nested(&bdev
->bd_mutex
, for_part
);
1495 bdev
->bd_part_count
--;
1497 if (!--bdev
->bd_openers
) {
1498 sync_blockdev(bdev
);
1501 if (bdev
->bd_contains
== bdev
) {
1502 if (disk
->fops
->release
)
1503 ret
= disk
->fops
->release(disk
, mode
);
1505 if (!bdev
->bd_openers
) {
1506 struct module
*owner
= disk
->fops
->owner
;
1510 disk_put_part(bdev
->bd_part
);
1511 bdev
->bd_part
= NULL
;
1512 bdev
->bd_disk
= NULL
;
1513 bdev
->bd_inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
1514 if (bdev
!= bdev
->bd_contains
)
1515 victim
= bdev
->bd_contains
;
1516 bdev
->bd_contains
= NULL
;
1519 mutex_unlock(&bdev
->bd_mutex
);
1522 __blkdev_put(victim
, mode
, 1);
1526 int blkdev_put(struct block_device
*bdev
, fmode_t mode
)
1528 return __blkdev_put(bdev
, mode
, 0);
1530 EXPORT_SYMBOL(blkdev_put
);
1532 static int blkdev_close(struct inode
* inode
, struct file
* filp
)
1534 struct block_device
*bdev
= I_BDEV(filp
->f_mapping
->host
);
1535 if (bdev
->bd_holder
== filp
)
1537 return blkdev_put(bdev
, filp
->f_mode
);
1540 static long block_ioctl(struct file
*file
, unsigned cmd
, unsigned long arg
)
1542 struct block_device
*bdev
= I_BDEV(file
->f_mapping
->host
);
1543 fmode_t mode
= file
->f_mode
;
1546 * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
1547 * to updated it before every ioctl.
1549 if (file
->f_flags
& O_NDELAY
)
1550 mode
|= FMODE_NDELAY
;
1552 mode
&= ~FMODE_NDELAY
;
1554 return blkdev_ioctl(bdev
, mode
, cmd
, arg
);
1558 * Write data to the block device. Only intended for the block device itself
1559 * and the raw driver which basically is a fake block device.
1561 * Does not take i_mutex for the write and thus is not for general purpose
1564 ssize_t
blkdev_aio_write(struct kiocb
*iocb
, const struct iovec
*iov
,
1565 unsigned long nr_segs
, loff_t pos
)
1567 struct file
*file
= iocb
->ki_filp
;
1570 BUG_ON(iocb
->ki_pos
!= pos
);
1572 ret
= __generic_file_aio_write(iocb
, iov
, nr_segs
, &iocb
->ki_pos
);
1573 if (ret
> 0 || ret
== -EIOCBQUEUED
) {
1576 err
= generic_write_sync(file
, pos
, ret
);
1577 if (err
< 0 && ret
> 0)
1582 EXPORT_SYMBOL_GPL(blkdev_aio_write
);
1585 * Try to release a page associated with block device when the system
1586 * is under memory pressure.
1588 static int blkdev_releasepage(struct page
*page
, gfp_t wait
)
1590 struct super_block
*super
= BDEV_I(page
->mapping
->host
)->bdev
.bd_super
;
1592 if (super
&& super
->s_op
->bdev_try_to_free_page
)
1593 return super
->s_op
->bdev_try_to_free_page(super
, page
, wait
);
1595 return try_to_free_buffers(page
);
1598 static const struct address_space_operations def_blk_aops
= {
1599 .readpage
= blkdev_readpage
,
1600 .writepage
= blkdev_writepage
,
1601 .sync_page
= block_sync_page
,
1602 .write_begin
= blkdev_write_begin
,
1603 .write_end
= blkdev_write_end
,
1604 .writepages
= generic_writepages
,
1605 .releasepage
= blkdev_releasepage
,
1606 .direct_IO
= blkdev_direct_IO
,
1609 const struct file_operations def_blk_fops
= {
1610 .open
= blkdev_open
,
1611 .release
= blkdev_close
,
1612 .llseek
= block_llseek
,
1613 .read
= do_sync_read
,
1614 .write
= do_sync_write
,
1615 .aio_read
= generic_file_aio_read
,
1616 .aio_write
= blkdev_aio_write
,
1617 .mmap
= generic_file_mmap
,
1618 .fsync
= blkdev_fsync
,
1619 .unlocked_ioctl
= block_ioctl
,
1620 #ifdef CONFIG_COMPAT
1621 .compat_ioctl
= compat_blkdev_ioctl
,
1623 .splice_read
= generic_file_splice_read
,
1624 .splice_write
= generic_file_splice_write
,
1627 int ioctl_by_bdev(struct block_device
*bdev
, unsigned cmd
, unsigned long arg
)
1630 mm_segment_t old_fs
= get_fs();
1632 res
= blkdev_ioctl(bdev
, 0, cmd
, arg
);
1637 EXPORT_SYMBOL(ioctl_by_bdev
);
1640 * lookup_bdev - lookup a struct block_device by name
1641 * @pathname: special file representing the block device
1643 * Get a reference to the blockdevice at @pathname in the current
1644 * namespace if possible and return it. Return ERR_PTR(error)
1647 struct block_device
*lookup_bdev(const char *pathname
)
1649 struct block_device
*bdev
;
1650 struct inode
*inode
;
1654 if (!pathname
|| !*pathname
)
1655 return ERR_PTR(-EINVAL
);
1657 error
= kern_path(pathname
, LOOKUP_FOLLOW
, &path
);
1659 return ERR_PTR(error
);
1661 inode
= path
.dentry
->d_inode
;
1663 if (!S_ISBLK(inode
->i_mode
))
1666 if (path
.mnt
->mnt_flags
& MNT_NODEV
)
1669 bdev
= bd_acquire(inode
);
1676 bdev
= ERR_PTR(error
);
1679 EXPORT_SYMBOL(lookup_bdev
);
1682 * open_bdev_exclusive - open a block device by name and set it up for use
1684 * @path: special file representing the block device
1685 * @mode: FMODE_... combination to pass be used
1686 * @holder: owner for exclusion
1688 * Open the blockdevice described by the special file at @path, claim it
1691 struct block_device
*open_bdev_exclusive(const char *path
, fmode_t mode
, void *holder
)
1693 struct block_device
*bdev
, *whole
;
1696 bdev
= lookup_bdev(path
);
1700 whole
= bd_start_claiming(bdev
, holder
);
1701 if (IS_ERR(whole
)) {
1706 error
= blkdev_get(bdev
, mode
);
1708 goto out_abort_claiming
;
1711 if ((mode
& FMODE_WRITE
) && bdev_read_only(bdev
))
1712 goto out_blkdev_put
;
1714 BUG_ON(bd_claim(bdev
, holder
) != 0);
1718 blkdev_put(bdev
, mode
);
1720 bd_abort_claiming(whole
, holder
);
1721 return ERR_PTR(error
);
1724 EXPORT_SYMBOL(open_bdev_exclusive
);
1727 * close_bdev_exclusive - close a blockdevice opened by open_bdev_exclusive()
1729 * @bdev: blockdevice to close
1730 * @mode: mode, must match that used to open.
1732 * This is the counterpart to open_bdev_exclusive().
1734 void close_bdev_exclusive(struct block_device
*bdev
, fmode_t mode
)
1737 blkdev_put(bdev
, mode
);
1740 EXPORT_SYMBOL(close_bdev_exclusive
);
1742 int __invalidate_device(struct block_device
*bdev
)
1744 struct super_block
*sb
= get_super(bdev
);
1749 * no need to lock the super, get_super holds the
1750 * read mutex so the filesystem cannot go away
1751 * under us (->put_super runs with the write lock
1754 shrink_dcache_sb(sb
);
1755 res
= invalidate_inodes(sb
);
1758 invalidate_bdev(bdev
);
1761 EXPORT_SYMBOL(__invalidate_device
);