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/magic.h>
20 #include <linux/buffer_head.h>
21 #include <linux/swap.h>
22 #include <linux/pagevec.h>
23 #include <linux/writeback.h>
24 #include <linux/mpage.h>
25 #include <linux/mount.h>
26 #include <linux/uio.h>
27 #include <linux/namei.h>
28 #include <linux/log2.h>
29 #include <linux/cleancache.h>
30 #include <linux/aio.h>
31 #include <asm/uaccess.h>
35 struct block_device bdev
;
36 struct inode vfs_inode
;
39 static const struct address_space_operations def_blk_aops
;
41 static inline struct bdev_inode
*BDEV_I(struct inode
*inode
)
43 return container_of(inode
, struct bdev_inode
, vfs_inode
);
46 inline struct block_device
*I_BDEV(struct inode
*inode
)
48 return &BDEV_I(inode
)->bdev
;
50 EXPORT_SYMBOL(I_BDEV
);
53 * Move the inode from its current bdi to a new bdi. If the inode is dirty we
54 * need to move it onto the dirty list of @dst so that the inode is always on
57 static void bdev_inode_switch_bdi(struct inode
*inode
,
58 struct backing_dev_info
*dst
)
60 struct backing_dev_info
*old
= inode
->i_data
.backing_dev_info
;
61 bool wakeup_bdi
= false;
63 if (unlikely(dst
== old
)) /* deadlock avoidance */
65 bdi_lock_two(&old
->wb
, &dst
->wb
);
66 spin_lock(&inode
->i_lock
);
67 inode
->i_data
.backing_dev_info
= dst
;
68 if (inode
->i_state
& I_DIRTY
) {
69 if (bdi_cap_writeback_dirty(dst
) && !wb_has_dirty_io(&dst
->wb
))
71 list_move(&inode
->i_wb_list
, &dst
->wb
.b_dirty
);
73 spin_unlock(&inode
->i_lock
);
74 spin_unlock(&old
->wb
.list_lock
);
75 spin_unlock(&dst
->wb
.list_lock
);
78 bdi_wakeup_thread_delayed(dst
);
81 /* Kill _all_ buffers and pagecache , dirty or not.. */
82 void kill_bdev(struct block_device
*bdev
)
84 struct address_space
*mapping
= bdev
->bd_inode
->i_mapping
;
86 if (mapping
->nrpages
== 0)
90 truncate_inode_pages(mapping
, 0);
92 EXPORT_SYMBOL(kill_bdev
);
94 /* Invalidate clean unused buffers and pagecache. */
95 void invalidate_bdev(struct block_device
*bdev
)
97 struct address_space
*mapping
= bdev
->bd_inode
->i_mapping
;
99 if (mapping
->nrpages
== 0)
102 invalidate_bh_lrus();
103 lru_add_drain_all(); /* make sure all lru add caches are flushed */
104 invalidate_mapping_pages(mapping
, 0, -1);
105 /* 99% of the time, we don't need to flush the cleancache on the bdev.
106 * But, for the strange corners, lets be cautious
108 cleancache_invalidate_inode(mapping
);
110 EXPORT_SYMBOL(invalidate_bdev
);
112 int set_blocksize(struct block_device
*bdev
, int size
)
114 /* Size must be a power of two, and between 512 and PAGE_SIZE */
115 if (size
> PAGE_SIZE
|| size
< 512 || !is_power_of_2(size
))
118 /* Size cannot be smaller than the size supported by the device */
119 if (size
< bdev_logical_block_size(bdev
))
122 /* Don't change the size if it is same as current */
123 if (bdev
->bd_block_size
!= size
) {
125 bdev
->bd_block_size
= size
;
126 bdev
->bd_inode
->i_blkbits
= blksize_bits(size
);
132 EXPORT_SYMBOL(set_blocksize
);
134 int sb_set_blocksize(struct super_block
*sb
, int size
)
136 if (set_blocksize(sb
->s_bdev
, size
))
138 /* If we get here, we know size is power of two
139 * and it's value is between 512 and PAGE_SIZE */
140 sb
->s_blocksize
= size
;
141 sb
->s_blocksize_bits
= blksize_bits(size
);
142 return sb
->s_blocksize
;
145 EXPORT_SYMBOL(sb_set_blocksize
);
147 int sb_min_blocksize(struct super_block
*sb
, int size
)
149 int minsize
= bdev_logical_block_size(sb
->s_bdev
);
152 return sb_set_blocksize(sb
, size
);
155 EXPORT_SYMBOL(sb_min_blocksize
);
158 blkdev_get_block(struct inode
*inode
, sector_t iblock
,
159 struct buffer_head
*bh
, int create
)
161 bh
->b_bdev
= I_BDEV(inode
);
162 bh
->b_blocknr
= iblock
;
163 set_buffer_mapped(bh
);
168 blkdev_direct_IO(int rw
, struct kiocb
*iocb
, const struct iovec
*iov
,
169 loff_t offset
, unsigned long nr_segs
)
171 struct file
*file
= iocb
->ki_filp
;
172 struct inode
*inode
= file
->f_mapping
->host
;
174 return __blockdev_direct_IO(rw
, iocb
, inode
, I_BDEV(inode
), iov
, offset
,
175 nr_segs
, blkdev_get_block
, NULL
, NULL
, 0);
178 int __sync_blockdev(struct block_device
*bdev
, int wait
)
183 return filemap_flush(bdev
->bd_inode
->i_mapping
);
184 return filemap_write_and_wait(bdev
->bd_inode
->i_mapping
);
188 * Write out and wait upon all the dirty data associated with a block
189 * device via its mapping. Does not take the superblock lock.
191 int sync_blockdev(struct block_device
*bdev
)
193 return __sync_blockdev(bdev
, 1);
195 EXPORT_SYMBOL(sync_blockdev
);
198 * Write out and wait upon all dirty data associated with this
199 * device. Filesystem data as well as the underlying block
200 * device. Takes the superblock lock.
202 int fsync_bdev(struct block_device
*bdev
)
204 struct super_block
*sb
= get_super(bdev
);
206 int res
= sync_filesystem(sb
);
210 return sync_blockdev(bdev
);
212 EXPORT_SYMBOL(fsync_bdev
);
215 * freeze_bdev -- lock a filesystem and force it into a consistent state
216 * @bdev: blockdevice to lock
218 * If a superblock is found on this device, we take the s_umount semaphore
219 * on it to make sure nobody unmounts until the snapshot creation is done.
220 * The reference counter (bd_fsfreeze_count) guarantees that only the last
221 * unfreeze process can unfreeze the frozen filesystem actually when multiple
222 * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
223 * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
226 struct super_block
*freeze_bdev(struct block_device
*bdev
)
228 struct super_block
*sb
;
231 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
232 if (++bdev
->bd_fsfreeze_count
> 1) {
234 * We don't even need to grab a reference - the first call
235 * to freeze_bdev grab an active reference and only the last
236 * thaw_bdev drops it.
238 sb
= get_super(bdev
);
240 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
244 sb
= get_active_super(bdev
);
247 error
= freeze_super(sb
);
249 deactivate_super(sb
);
250 bdev
->bd_fsfreeze_count
--;
251 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
252 return ERR_PTR(error
);
254 deactivate_super(sb
);
257 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
258 return sb
; /* thaw_bdev releases s->s_umount */
260 EXPORT_SYMBOL(freeze_bdev
);
263 * thaw_bdev -- unlock filesystem
264 * @bdev: blockdevice to unlock
265 * @sb: associated superblock
267 * Unlocks the filesystem and marks it writeable again after freeze_bdev().
269 int thaw_bdev(struct block_device
*bdev
, struct super_block
*sb
)
273 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
274 if (!bdev
->bd_fsfreeze_count
)
278 if (--bdev
->bd_fsfreeze_count
> 0)
284 error
= thaw_super(sb
);
286 bdev
->bd_fsfreeze_count
++;
287 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
291 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
294 EXPORT_SYMBOL(thaw_bdev
);
296 static int blkdev_writepage(struct page
*page
, struct writeback_control
*wbc
)
298 return block_write_full_page(page
, blkdev_get_block
, wbc
);
301 static int blkdev_readpage(struct file
* file
, struct page
* page
)
303 return block_read_full_page(page
, blkdev_get_block
);
306 static int blkdev_write_begin(struct file
*file
, struct address_space
*mapping
,
307 loff_t pos
, unsigned len
, unsigned flags
,
308 struct page
**pagep
, void **fsdata
)
310 return block_write_begin(mapping
, pos
, len
, flags
, pagep
,
314 static int blkdev_write_end(struct file
*file
, struct address_space
*mapping
,
315 loff_t pos
, unsigned len
, unsigned copied
,
316 struct page
*page
, void *fsdata
)
319 ret
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
322 page_cache_release(page
);
329 * for a block special file file_inode(file)->i_size is zero
330 * so we compute the size by hand (just as in block_read/write above)
332 static loff_t
block_llseek(struct file
*file
, loff_t offset
, int whence
)
334 struct inode
*bd_inode
= file
->f_mapping
->host
;
338 mutex_lock(&bd_inode
->i_mutex
);
339 size
= i_size_read(bd_inode
);
347 offset
+= file
->f_pos
;
353 if (offset
>= 0 && offset
<= size
) {
354 if (offset
!= file
->f_pos
) {
355 file
->f_pos
= offset
;
360 mutex_unlock(&bd_inode
->i_mutex
);
364 int blkdev_fsync(struct file
*filp
, loff_t start
, loff_t end
, int datasync
)
366 struct inode
*bd_inode
= filp
->f_mapping
->host
;
367 struct block_device
*bdev
= I_BDEV(bd_inode
);
370 error
= filemap_write_and_wait_range(filp
->f_mapping
, start
, end
);
375 * There is no need to serialise calls to blkdev_issue_flush with
376 * i_mutex and doing so causes performance issues with concurrent
377 * O_SYNC writers to a block device.
379 error
= blkdev_issue_flush(bdev
, GFP_KERNEL
, NULL
);
380 if (error
== -EOPNOTSUPP
)
385 EXPORT_SYMBOL(blkdev_fsync
);
391 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(bdev_lock
);
392 static struct kmem_cache
* bdev_cachep __read_mostly
;
394 static struct inode
*bdev_alloc_inode(struct super_block
*sb
)
396 struct bdev_inode
*ei
= kmem_cache_alloc(bdev_cachep
, GFP_KERNEL
);
399 return &ei
->vfs_inode
;
402 static void bdev_i_callback(struct rcu_head
*head
)
404 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
405 struct bdev_inode
*bdi
= BDEV_I(inode
);
407 kmem_cache_free(bdev_cachep
, bdi
);
410 static void bdev_destroy_inode(struct inode
*inode
)
412 call_rcu(&inode
->i_rcu
, bdev_i_callback
);
415 static void init_once(void *foo
)
417 struct bdev_inode
*ei
= (struct bdev_inode
*) foo
;
418 struct block_device
*bdev
= &ei
->bdev
;
420 memset(bdev
, 0, sizeof(*bdev
));
421 mutex_init(&bdev
->bd_mutex
);
422 INIT_LIST_HEAD(&bdev
->bd_inodes
);
423 INIT_LIST_HEAD(&bdev
->bd_list
);
425 INIT_LIST_HEAD(&bdev
->bd_holder_disks
);
427 inode_init_once(&ei
->vfs_inode
);
428 /* Initialize mutex for freeze. */
429 mutex_init(&bdev
->bd_fsfreeze_mutex
);
432 static inline void __bd_forget(struct inode
*inode
)
434 list_del_init(&inode
->i_devices
);
435 inode
->i_bdev
= NULL
;
436 inode
->i_mapping
= &inode
->i_data
;
439 static void bdev_evict_inode(struct inode
*inode
)
441 struct block_device
*bdev
= &BDEV_I(inode
)->bdev
;
443 truncate_inode_pages(&inode
->i_data
, 0);
444 invalidate_inode_buffers(inode
); /* is it needed here? */
446 spin_lock(&bdev_lock
);
447 while ( (p
= bdev
->bd_inodes
.next
) != &bdev
->bd_inodes
) {
448 __bd_forget(list_entry(p
, struct inode
, i_devices
));
450 list_del_init(&bdev
->bd_list
);
451 spin_unlock(&bdev_lock
);
454 static const struct super_operations bdev_sops
= {
455 .statfs
= simple_statfs
,
456 .alloc_inode
= bdev_alloc_inode
,
457 .destroy_inode
= bdev_destroy_inode
,
458 .drop_inode
= generic_delete_inode
,
459 .evict_inode
= bdev_evict_inode
,
462 static struct dentry
*bd_mount(struct file_system_type
*fs_type
,
463 int flags
, const char *dev_name
, void *data
)
465 return mount_pseudo(fs_type
, "bdev:", &bdev_sops
, NULL
, BDEVFS_MAGIC
);
468 static struct file_system_type bd_type
= {
471 .kill_sb
= kill_anon_super
,
474 static struct super_block
*blockdev_superblock __read_mostly
;
476 void __init
bdev_cache_init(void)
479 static struct vfsmount
*bd_mnt
;
481 bdev_cachep
= kmem_cache_create("bdev_cache", sizeof(struct bdev_inode
),
482 0, (SLAB_HWCACHE_ALIGN
|SLAB_RECLAIM_ACCOUNT
|
483 SLAB_MEM_SPREAD
|SLAB_PANIC
),
485 err
= register_filesystem(&bd_type
);
487 panic("Cannot register bdev pseudo-fs");
488 bd_mnt
= kern_mount(&bd_type
);
490 panic("Cannot create bdev pseudo-fs");
491 blockdev_superblock
= bd_mnt
->mnt_sb
; /* For writeback */
495 * Most likely _very_ bad one - but then it's hardly critical for small
496 * /dev and can be fixed when somebody will need really large one.
497 * Keep in mind that it will be fed through icache hash function too.
499 static inline unsigned long hash(dev_t dev
)
501 return MAJOR(dev
)+MINOR(dev
);
504 static int bdev_test(struct inode
*inode
, void *data
)
506 return BDEV_I(inode
)->bdev
.bd_dev
== *(dev_t
*)data
;
509 static int bdev_set(struct inode
*inode
, void *data
)
511 BDEV_I(inode
)->bdev
.bd_dev
= *(dev_t
*)data
;
515 static LIST_HEAD(all_bdevs
);
517 struct block_device
*bdget(dev_t dev
)
519 struct block_device
*bdev
;
522 inode
= iget5_locked(blockdev_superblock
, hash(dev
),
523 bdev_test
, bdev_set
, &dev
);
528 bdev
= &BDEV_I(inode
)->bdev
;
530 if (inode
->i_state
& I_NEW
) {
531 bdev
->bd_contains
= NULL
;
532 bdev
->bd_super
= NULL
;
533 bdev
->bd_inode
= inode
;
534 bdev
->bd_block_size
= (1 << inode
->i_blkbits
);
535 bdev
->bd_part_count
= 0;
536 bdev
->bd_invalidated
= 0;
537 inode
->i_mode
= S_IFBLK
;
539 inode
->i_bdev
= bdev
;
540 inode
->i_data
.a_ops
= &def_blk_aops
;
541 mapping_set_gfp_mask(&inode
->i_data
, GFP_USER
);
542 inode
->i_data
.backing_dev_info
= &default_backing_dev_info
;
543 spin_lock(&bdev_lock
);
544 list_add(&bdev
->bd_list
, &all_bdevs
);
545 spin_unlock(&bdev_lock
);
546 unlock_new_inode(inode
);
551 EXPORT_SYMBOL(bdget
);
554 * bdgrab -- Grab a reference to an already referenced block device
555 * @bdev: Block device to grab a reference to.
557 struct block_device
*bdgrab(struct block_device
*bdev
)
559 ihold(bdev
->bd_inode
);
562 EXPORT_SYMBOL(bdgrab
);
564 long nr_blockdev_pages(void)
566 struct block_device
*bdev
;
568 spin_lock(&bdev_lock
);
569 list_for_each_entry(bdev
, &all_bdevs
, bd_list
) {
570 ret
+= bdev
->bd_inode
->i_mapping
->nrpages
;
572 spin_unlock(&bdev_lock
);
576 void bdput(struct block_device
*bdev
)
578 iput(bdev
->bd_inode
);
581 EXPORT_SYMBOL(bdput
);
583 static struct block_device
*bd_acquire(struct inode
*inode
)
585 struct block_device
*bdev
;
587 spin_lock(&bdev_lock
);
588 bdev
= inode
->i_bdev
;
590 ihold(bdev
->bd_inode
);
591 spin_unlock(&bdev_lock
);
594 spin_unlock(&bdev_lock
);
596 bdev
= bdget(inode
->i_rdev
);
598 spin_lock(&bdev_lock
);
599 if (!inode
->i_bdev
) {
601 * We take an additional reference to bd_inode,
602 * and it's released in clear_inode() of inode.
603 * So, we can access it via ->i_mapping always
606 ihold(bdev
->bd_inode
);
607 inode
->i_bdev
= bdev
;
608 inode
->i_mapping
= bdev
->bd_inode
->i_mapping
;
609 list_add(&inode
->i_devices
, &bdev
->bd_inodes
);
611 spin_unlock(&bdev_lock
);
616 static inline int sb_is_blkdev_sb(struct super_block
*sb
)
618 return sb
== blockdev_superblock
;
621 /* Call when you free inode */
623 void bd_forget(struct inode
*inode
)
625 struct block_device
*bdev
= NULL
;
627 spin_lock(&bdev_lock
);
628 if (!sb_is_blkdev_sb(inode
->i_sb
))
629 bdev
= inode
->i_bdev
;
631 spin_unlock(&bdev_lock
);
634 iput(bdev
->bd_inode
);
638 * bd_may_claim - test whether a block device can be claimed
639 * @bdev: block device of interest
640 * @whole: whole block device containing @bdev, may equal @bdev
641 * @holder: holder trying to claim @bdev
643 * Test whether @bdev can be claimed by @holder.
646 * spin_lock(&bdev_lock).
649 * %true if @bdev can be claimed, %false otherwise.
651 static bool bd_may_claim(struct block_device
*bdev
, struct block_device
*whole
,
654 if (bdev
->bd_holder
== holder
)
655 return true; /* already a holder */
656 else if (bdev
->bd_holder
!= NULL
)
657 return false; /* held by someone else */
658 else if (whole
== bdev
)
659 return true; /* is a whole device which isn't held */
661 else if (whole
->bd_holder
== bd_may_claim
)
662 return true; /* is a partition of a device that is being partitioned */
663 else if (whole
->bd_holder
!= NULL
)
664 return false; /* is a partition of a held device */
666 return true; /* is a partition of an un-held device */
670 * bd_prepare_to_claim - prepare to claim a block device
671 * @bdev: block device of interest
672 * @whole: the whole device containing @bdev, may equal @bdev
673 * @holder: holder trying to claim @bdev
675 * Prepare to claim @bdev. This function fails if @bdev is already
676 * claimed by another holder and waits if another claiming is in
677 * progress. This function doesn't actually claim. On successful
678 * return, the caller has ownership of bd_claiming and bd_holder[s].
681 * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab
685 * 0 if @bdev can be claimed, -EBUSY otherwise.
687 static int bd_prepare_to_claim(struct block_device
*bdev
,
688 struct block_device
*whole
, void *holder
)
691 /* if someone else claimed, fail */
692 if (!bd_may_claim(bdev
, whole
, holder
))
695 /* if claiming is already in progress, wait for it to finish */
696 if (whole
->bd_claiming
) {
697 wait_queue_head_t
*wq
= bit_waitqueue(&whole
->bd_claiming
, 0);
700 prepare_to_wait(wq
, &wait
, TASK_UNINTERRUPTIBLE
);
701 spin_unlock(&bdev_lock
);
703 finish_wait(wq
, &wait
);
704 spin_lock(&bdev_lock
);
713 * bd_start_claiming - start claiming a block device
714 * @bdev: block device of interest
715 * @holder: holder trying to claim @bdev
717 * @bdev is about to be opened exclusively. Check @bdev can be opened
718 * exclusively and mark that an exclusive open is in progress. Each
719 * successful call to this function must be matched with a call to
720 * either bd_finish_claiming() or bd_abort_claiming() (which do not
723 * This function is used to gain exclusive access to the block device
724 * without actually causing other exclusive open attempts to fail. It
725 * should be used when the open sequence itself requires exclusive
726 * access but may subsequently fail.
732 * Pointer to the block device containing @bdev on success, ERR_PTR()
735 static struct block_device
*bd_start_claiming(struct block_device
*bdev
,
738 struct gendisk
*disk
;
739 struct block_device
*whole
;
745 * @bdev might not have been initialized properly yet, look up
746 * and grab the outer block device the hard way.
748 disk
= get_gendisk(bdev
->bd_dev
, &partno
);
750 return ERR_PTR(-ENXIO
);
753 * Normally, @bdev should equal what's returned from bdget_disk()
754 * if partno is 0; however, some drivers (floppy) use multiple
755 * bdev's for the same physical device and @bdev may be one of the
756 * aliases. Keep @bdev if partno is 0. This means claimer
757 * tracking is broken for those devices but it has always been that
761 whole
= bdget_disk(disk
, 0);
763 whole
= bdgrab(bdev
);
765 module_put(disk
->fops
->owner
);
768 return ERR_PTR(-ENOMEM
);
770 /* prepare to claim, if successful, mark claiming in progress */
771 spin_lock(&bdev_lock
);
773 err
= bd_prepare_to_claim(bdev
, whole
, holder
);
775 whole
->bd_claiming
= holder
;
776 spin_unlock(&bdev_lock
);
779 spin_unlock(&bdev_lock
);
786 struct bd_holder_disk
{
787 struct list_head list
;
788 struct gendisk
*disk
;
792 static struct bd_holder_disk
*bd_find_holder_disk(struct block_device
*bdev
,
793 struct gendisk
*disk
)
795 struct bd_holder_disk
*holder
;
797 list_for_each_entry(holder
, &bdev
->bd_holder_disks
, list
)
798 if (holder
->disk
== disk
)
803 static int add_symlink(struct kobject
*from
, struct kobject
*to
)
805 return sysfs_create_link(from
, to
, kobject_name(to
));
808 static void del_symlink(struct kobject
*from
, struct kobject
*to
)
810 sysfs_remove_link(from
, kobject_name(to
));
814 * bd_link_disk_holder - create symlinks between holding disk and slave bdev
815 * @bdev: the claimed slave bdev
816 * @disk: the holding disk
818 * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
820 * This functions creates the following sysfs symlinks.
822 * - from "slaves" directory of the holder @disk to the claimed @bdev
823 * - from "holders" directory of the @bdev to the holder @disk
825 * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is
826 * passed to bd_link_disk_holder(), then:
828 * /sys/block/dm-0/slaves/sda --> /sys/block/sda
829 * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
831 * The caller must have claimed @bdev before calling this function and
832 * ensure that both @bdev and @disk are valid during the creation and
833 * lifetime of these symlinks.
839 * 0 on success, -errno on failure.
841 int bd_link_disk_holder(struct block_device
*bdev
, struct gendisk
*disk
)
843 struct bd_holder_disk
*holder
;
846 mutex_lock(&bdev
->bd_mutex
);
848 WARN_ON_ONCE(!bdev
->bd_holder
);
850 /* FIXME: remove the following once add_disk() handles errors */
851 if (WARN_ON(!disk
->slave_dir
|| !bdev
->bd_part
->holder_dir
))
854 holder
= bd_find_holder_disk(bdev
, disk
);
860 holder
= kzalloc(sizeof(*holder
), GFP_KERNEL
);
866 INIT_LIST_HEAD(&holder
->list
);
870 ret
= add_symlink(disk
->slave_dir
, &part_to_dev(bdev
->bd_part
)->kobj
);
874 ret
= add_symlink(bdev
->bd_part
->holder_dir
, &disk_to_dev(disk
)->kobj
);
878 * bdev could be deleted beneath us which would implicitly destroy
879 * the holder directory. Hold on to it.
881 kobject_get(bdev
->bd_part
->holder_dir
);
883 list_add(&holder
->list
, &bdev
->bd_holder_disks
);
887 del_symlink(disk
->slave_dir
, &part_to_dev(bdev
->bd_part
)->kobj
);
891 mutex_unlock(&bdev
->bd_mutex
);
894 EXPORT_SYMBOL_GPL(bd_link_disk_holder
);
897 * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder()
898 * @bdev: the calimed slave bdev
899 * @disk: the holding disk
901 * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
906 void bd_unlink_disk_holder(struct block_device
*bdev
, struct gendisk
*disk
)
908 struct bd_holder_disk
*holder
;
910 mutex_lock(&bdev
->bd_mutex
);
912 holder
= bd_find_holder_disk(bdev
, disk
);
914 if (!WARN_ON_ONCE(holder
== NULL
) && !--holder
->refcnt
) {
915 del_symlink(disk
->slave_dir
, &part_to_dev(bdev
->bd_part
)->kobj
);
916 del_symlink(bdev
->bd_part
->holder_dir
,
917 &disk_to_dev(disk
)->kobj
);
918 kobject_put(bdev
->bd_part
->holder_dir
);
919 list_del_init(&holder
->list
);
923 mutex_unlock(&bdev
->bd_mutex
);
925 EXPORT_SYMBOL_GPL(bd_unlink_disk_holder
);
929 * flush_disk - invalidates all buffer-cache entries on a disk
931 * @bdev: struct block device to be flushed
932 * @kill_dirty: flag to guide handling of dirty inodes
934 * Invalidates all buffer-cache entries on a disk. It should be called
935 * when a disk has been changed -- either by a media change or online
938 static void flush_disk(struct block_device
*bdev
, bool kill_dirty
)
940 if (__invalidate_device(bdev
, kill_dirty
)) {
941 char name
[BDEVNAME_SIZE
] = "";
944 disk_name(bdev
->bd_disk
, 0, name
);
945 printk(KERN_WARNING
"VFS: busy inodes on changed media or "
946 "resized disk %s\n", name
);
951 if (disk_part_scan_enabled(bdev
->bd_disk
))
952 bdev
->bd_invalidated
= 1;
956 * check_disk_size_change - checks for disk size change and adjusts bdev size.
957 * @disk: struct gendisk to check
958 * @bdev: struct bdev to adjust.
960 * This routine checks to see if the bdev size does not match the disk size
961 * and adjusts it if it differs.
963 void check_disk_size_change(struct gendisk
*disk
, struct block_device
*bdev
)
965 loff_t disk_size
, bdev_size
;
967 disk_size
= (loff_t
)get_capacity(disk
) << 9;
968 bdev_size
= i_size_read(bdev
->bd_inode
);
969 if (disk_size
!= bdev_size
) {
970 char name
[BDEVNAME_SIZE
];
972 disk_name(disk
, 0, name
);
974 "%s: detected capacity change from %lld to %lld\n",
975 name
, bdev_size
, disk_size
);
976 i_size_write(bdev
->bd_inode
, disk_size
);
977 flush_disk(bdev
, false);
980 EXPORT_SYMBOL(check_disk_size_change
);
983 * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back
984 * @disk: struct gendisk to be revalidated
986 * This routine is a wrapper for lower-level driver's revalidate_disk
987 * call-backs. It is used to do common pre and post operations needed
988 * for all revalidate_disk operations.
990 int revalidate_disk(struct gendisk
*disk
)
992 struct block_device
*bdev
;
995 if (disk
->fops
->revalidate_disk
)
996 ret
= disk
->fops
->revalidate_disk(disk
);
998 bdev
= bdget_disk(disk
, 0);
1002 mutex_lock(&bdev
->bd_mutex
);
1003 check_disk_size_change(disk
, bdev
);
1004 bdev
->bd_invalidated
= 0;
1005 mutex_unlock(&bdev
->bd_mutex
);
1009 EXPORT_SYMBOL(revalidate_disk
);
1012 * This routine checks whether a removable media has been changed,
1013 * and invalidates all buffer-cache-entries in that case. This
1014 * is a relatively slow routine, so we have to try to minimize using
1015 * it. Thus it is called only upon a 'mount' or 'open'. This
1016 * is the best way of combining speed and utility, I think.
1017 * People changing diskettes in the middle of an operation deserve
1020 int check_disk_change(struct block_device
*bdev
)
1022 struct gendisk
*disk
= bdev
->bd_disk
;
1023 const struct block_device_operations
*bdops
= disk
->fops
;
1024 unsigned int events
;
1026 events
= disk_clear_events(disk
, DISK_EVENT_MEDIA_CHANGE
|
1027 #ifdef CONFIG_MTK_MULTI_PARTITION_MOUNT_ONLY_SUPPORT
1028 DISK_EVENT_EJECT_REQUEST
| DISK_EVENT_MEDIA_DISAPPEAR
); //add DISK_EVENT_MEDIA_DISAPPEAR for sd hotplug
1030 DISK_EVENT_EJECT_REQUEST
);
1032 if (!(events
& DISK_EVENT_MEDIA_CHANGE
))
1035 flush_disk(bdev
, true);
1036 if (bdops
->revalidate_disk
)
1037 bdops
->revalidate_disk(bdev
->bd_disk
);
1041 EXPORT_SYMBOL(check_disk_change
);
1043 void bd_set_size(struct block_device
*bdev
, loff_t size
)
1045 unsigned bsize
= bdev_logical_block_size(bdev
);
1047 mutex_lock(&bdev
->bd_inode
->i_mutex
);
1048 i_size_write(bdev
->bd_inode
, size
);
1049 mutex_unlock(&bdev
->bd_inode
->i_mutex
);
1050 while (bsize
< PAGE_CACHE_SIZE
) {
1055 bdev
->bd_block_size
= bsize
;
1056 bdev
->bd_inode
->i_blkbits
= blksize_bits(bsize
);
1058 EXPORT_SYMBOL(bd_set_size
);
1060 static void __blkdev_put(struct block_device
*bdev
, fmode_t mode
, int for_part
);
1065 * mutex_lock(part->bd_mutex)
1066 * mutex_lock_nested(whole->bd_mutex, 1)
1069 static int __blkdev_get(struct block_device
*bdev
, fmode_t mode
, int for_part
)
1071 struct gendisk
*disk
;
1072 struct module
*owner
;
1077 if (mode
& FMODE_READ
)
1079 if (mode
& FMODE_WRITE
)
1082 * hooks: /n/, see "layering violations".
1085 ret
= devcgroup_inode_permission(bdev
->bd_inode
, perm
);
1095 disk
= get_gendisk(bdev
->bd_dev
, &partno
);
1098 owner
= disk
->fops
->owner
;
1100 disk_block_events(disk
);
1101 mutex_lock_nested(&bdev
->bd_mutex
, for_part
);
1102 if (!bdev
->bd_openers
) {
1103 bdev
->bd_disk
= disk
;
1104 bdev
->bd_queue
= disk
->queue
;
1105 bdev
->bd_contains
= bdev
;
1107 struct backing_dev_info
*bdi
;
1110 bdev
->bd_part
= disk_get_part(disk
, partno
);
1115 if (disk
->fops
->open
) {
1116 ret
= disk
->fops
->open(bdev
, mode
);
1117 if (ret
== -ERESTARTSYS
) {
1118 /* Lost a race with 'disk' being
1119 * deleted, try again.
1122 disk_put_part(bdev
->bd_part
);
1123 bdev
->bd_part
= NULL
;
1124 bdev
->bd_disk
= NULL
;
1125 bdev
->bd_queue
= NULL
;
1126 mutex_unlock(&bdev
->bd_mutex
);
1127 disk_unblock_events(disk
);
1135 bd_set_size(bdev
,(loff_t
)get_capacity(disk
)<<9);
1136 bdi
= blk_get_backing_dev_info(bdev
);
1138 bdi
= &default_backing_dev_info
;
1139 bdev_inode_switch_bdi(bdev
->bd_inode
, bdi
);
1143 * If the device is invalidated, rescan partition
1144 * if open succeeded or failed with -ENOMEDIUM.
1145 * The latter is necessary to prevent ghost
1146 * partitions on a removed medium.
1148 if (bdev
->bd_invalidated
) {
1150 rescan_partitions(disk
, bdev
);
1151 else if (ret
== -ENOMEDIUM
)
1152 invalidate_partitions(disk
, bdev
);
1157 struct block_device
*whole
;
1158 whole
= bdget_disk(disk
, 0);
1163 ret
= __blkdev_get(whole
, mode
, 1);
1166 bdev
->bd_contains
= whole
;
1167 bdev_inode_switch_bdi(bdev
->bd_inode
,
1168 whole
->bd_inode
->i_data
.backing_dev_info
);
1169 bdev
->bd_part
= disk_get_part(disk
, partno
);
1170 if (!(disk
->flags
& GENHD_FL_UP
) ||
1171 !bdev
->bd_part
|| !bdev
->bd_part
->nr_sects
) {
1175 bd_set_size(bdev
, (loff_t
)bdev
->bd_part
->nr_sects
<< 9);
1178 if (bdev
->bd_contains
== bdev
) {
1180 if (bdev
->bd_disk
->fops
->open
)
1181 ret
= bdev
->bd_disk
->fops
->open(bdev
, mode
);
1182 /* the same as first opener case, read comment there */
1183 if (bdev
->bd_invalidated
) {
1185 rescan_partitions(bdev
->bd_disk
, bdev
);
1186 else if (ret
== -ENOMEDIUM
)
1187 invalidate_partitions(bdev
->bd_disk
, bdev
);
1190 goto out_unlock_bdev
;
1192 /* only one opener holds refs to the module and disk */
1198 bdev
->bd_part_count
++;
1199 mutex_unlock(&bdev
->bd_mutex
);
1200 disk_unblock_events(disk
);
1204 disk_put_part(bdev
->bd_part
);
1205 bdev
->bd_disk
= NULL
;
1206 bdev
->bd_part
= NULL
;
1207 bdev
->bd_queue
= NULL
;
1208 bdev_inode_switch_bdi(bdev
->bd_inode
, &default_backing_dev_info
);
1209 if (bdev
!= bdev
->bd_contains
)
1210 __blkdev_put(bdev
->bd_contains
, mode
, 1);
1211 bdev
->bd_contains
= NULL
;
1213 mutex_unlock(&bdev
->bd_mutex
);
1214 disk_unblock_events(disk
);
1224 * blkdev_get - open a block device
1225 * @bdev: block_device to open
1226 * @mode: FMODE_* mask
1227 * @holder: exclusive holder identifier
1229 * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is
1230 * open with exclusive access. Specifying %FMODE_EXCL with %NULL
1231 * @holder is invalid. Exclusive opens may nest for the same @holder.
1233 * On success, the reference count of @bdev is unchanged. On failure,
1240 * 0 on success, -errno on failure.
1242 int blkdev_get(struct block_device
*bdev
, fmode_t mode
, void *holder
)
1244 struct block_device
*whole
= NULL
;
1247 WARN_ON_ONCE((mode
& FMODE_EXCL
) && !holder
);
1249 if ((mode
& FMODE_EXCL
) && holder
) {
1250 whole
= bd_start_claiming(bdev
, holder
);
1251 if (IS_ERR(whole
)) {
1253 return PTR_ERR(whole
);
1257 res
= __blkdev_get(bdev
, mode
, 0);
1260 struct gendisk
*disk
= whole
->bd_disk
;
1262 /* finish claiming */
1263 mutex_lock(&bdev
->bd_mutex
);
1264 spin_lock(&bdev_lock
);
1267 BUG_ON(!bd_may_claim(bdev
, whole
, holder
));
1269 * Note that for a whole device bd_holders
1270 * will be incremented twice, and bd_holder
1271 * will be set to bd_may_claim before being
1274 whole
->bd_holders
++;
1275 whole
->bd_holder
= bd_may_claim
;
1277 bdev
->bd_holder
= holder
;
1280 /* tell others that we're done */
1281 BUG_ON(whole
->bd_claiming
!= holder
);
1282 whole
->bd_claiming
= NULL
;
1283 wake_up_bit(&whole
->bd_claiming
, 0);
1285 spin_unlock(&bdev_lock
);
1288 * Block event polling for write claims if requested. Any
1289 * write holder makes the write_holder state stick until
1290 * all are released. This is good enough and tracking
1291 * individual writeable reference is too fragile given the
1292 * way @mode is used in blkdev_get/put().
1294 if (!res
&& (mode
& FMODE_WRITE
) && !bdev
->bd_write_holder
&&
1295 (disk
->flags
& GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE
)) {
1296 bdev
->bd_write_holder
= true;
1297 disk_block_events(disk
);
1300 mutex_unlock(&bdev
->bd_mutex
);
1306 EXPORT_SYMBOL(blkdev_get
);
1309 * blkdev_get_by_path - open a block device by name
1310 * @path: path to the block device to open
1311 * @mode: FMODE_* mask
1312 * @holder: exclusive holder identifier
1314 * Open the blockdevice described by the device file at @path. @mode
1315 * and @holder are identical to blkdev_get().
1317 * On success, the returned block_device has reference count of one.
1323 * Pointer to block_device on success, ERR_PTR(-errno) on failure.
1325 struct block_device
*blkdev_get_by_path(const char *path
, fmode_t mode
,
1328 struct block_device
*bdev
;
1331 bdev
= lookup_bdev(path
);
1335 err
= blkdev_get(bdev
, mode
, holder
);
1337 return ERR_PTR(err
);
1339 if ((mode
& FMODE_WRITE
) && bdev_read_only(bdev
)) {
1340 blkdev_put(bdev
, mode
);
1341 return ERR_PTR(-EACCES
);
1346 EXPORT_SYMBOL(blkdev_get_by_path
);
1349 * blkdev_get_by_dev - open a block device by device number
1350 * @dev: device number of block device to open
1351 * @mode: FMODE_* mask
1352 * @holder: exclusive holder identifier
1354 * Open the blockdevice described by device number @dev. @mode and
1355 * @holder are identical to blkdev_get().
1357 * Use it ONLY if you really do not have anything better - i.e. when
1358 * you are behind a truly sucky interface and all you are given is a
1359 * device number. _Never_ to be used for internal purposes. If you
1360 * ever need it - reconsider your API.
1362 * On success, the returned block_device has reference count of one.
1368 * Pointer to block_device on success, ERR_PTR(-errno) on failure.
1370 struct block_device
*blkdev_get_by_dev(dev_t dev
, fmode_t mode
, void *holder
)
1372 struct block_device
*bdev
;
1377 return ERR_PTR(-ENOMEM
);
1379 err
= blkdev_get(bdev
, mode
, holder
);
1381 return ERR_PTR(err
);
1385 EXPORT_SYMBOL(blkdev_get_by_dev
);
1387 static int blkdev_open(struct inode
* inode
, struct file
* filp
)
1389 struct block_device
*bdev
;
1392 * Preserve backwards compatibility and allow large file access
1393 * even if userspace doesn't ask for it explicitly. Some mkfs
1394 * binary needs it. We might want to drop this workaround
1395 * during an unstable branch.
1397 filp
->f_flags
|= O_LARGEFILE
;
1399 if (filp
->f_flags
& O_NDELAY
)
1400 filp
->f_mode
|= FMODE_NDELAY
;
1401 if (filp
->f_flags
& O_EXCL
)
1402 filp
->f_mode
|= FMODE_EXCL
;
1403 if ((filp
->f_flags
& O_ACCMODE
) == 3)
1404 filp
->f_mode
|= FMODE_WRITE_IOCTL
;
1406 bdev
= bd_acquire(inode
);
1410 filp
->f_mapping
= bdev
->bd_inode
->i_mapping
;
1412 return blkdev_get(bdev
, filp
->f_mode
, filp
);
1415 static void __blkdev_put(struct block_device
*bdev
, fmode_t mode
, int for_part
)
1417 struct gendisk
*disk
= bdev
->bd_disk
;
1418 struct block_device
*victim
= NULL
;
1420 mutex_lock_nested(&bdev
->bd_mutex
, for_part
);
1422 bdev
->bd_part_count
--;
1424 if (!--bdev
->bd_openers
) {
1425 WARN_ON_ONCE(bdev
->bd_holders
);
1426 sync_blockdev(bdev
);
1428 /* ->release can cause the old bdi to disappear,
1429 * so must switch it out first
1431 bdev_inode_switch_bdi(bdev
->bd_inode
,
1432 &default_backing_dev_info
);
1434 if (bdev
->bd_contains
== bdev
) {
1435 if (disk
->fops
->release
)
1436 disk
->fops
->release(disk
, mode
);
1438 if (!bdev
->bd_openers
) {
1439 struct module
*owner
= disk
->fops
->owner
;
1441 disk_put_part(bdev
->bd_part
);
1442 bdev
->bd_part
= NULL
;
1443 bdev
->bd_disk
= NULL
;
1444 if (bdev
!= bdev
->bd_contains
)
1445 victim
= bdev
->bd_contains
;
1446 bdev
->bd_contains
= NULL
;
1451 mutex_unlock(&bdev
->bd_mutex
);
1454 __blkdev_put(victim
, mode
, 1);
1457 void blkdev_put(struct block_device
*bdev
, fmode_t mode
)
1459 mutex_lock(&bdev
->bd_mutex
);
1461 if (mode
& FMODE_EXCL
) {
1465 * Release a claim on the device. The holder fields
1466 * are protected with bdev_lock. bd_mutex is to
1467 * synchronize disk_holder unlinking.
1469 spin_lock(&bdev_lock
);
1471 WARN_ON_ONCE(--bdev
->bd_holders
< 0);
1472 WARN_ON_ONCE(--bdev
->bd_contains
->bd_holders
< 0);
1474 /* bd_contains might point to self, check in a separate step */
1475 if ((bdev_free
= !bdev
->bd_holders
))
1476 bdev
->bd_holder
= NULL
;
1477 if (!bdev
->bd_contains
->bd_holders
)
1478 bdev
->bd_contains
->bd_holder
= NULL
;
1480 spin_unlock(&bdev_lock
);
1483 * If this was the last claim, remove holder link and
1484 * unblock evpoll if it was a write holder.
1486 if (bdev_free
&& bdev
->bd_write_holder
) {
1487 disk_unblock_events(bdev
->bd_disk
);
1488 bdev
->bd_write_holder
= false;
1493 * Trigger event checking and tell drivers to flush MEDIA_CHANGE
1494 * event. This is to ensure detection of media removal commanded
1495 * from userland - e.g. eject(1).
1497 disk_flush_events(bdev
->bd_disk
, DISK_EVENT_MEDIA_CHANGE
);
1499 mutex_unlock(&bdev
->bd_mutex
);
1501 __blkdev_put(bdev
, mode
, 0);
1503 EXPORT_SYMBOL(blkdev_put
);
1505 static int blkdev_close(struct inode
* inode
, struct file
* filp
)
1507 struct block_device
*bdev
= I_BDEV(filp
->f_mapping
->host
);
1508 blkdev_put(bdev
, filp
->f_mode
);
1512 static long block_ioctl(struct file
*file
, unsigned cmd
, unsigned long arg
)
1514 struct block_device
*bdev
= I_BDEV(file
->f_mapping
->host
);
1515 fmode_t mode
= file
->f_mode
;
1518 * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
1519 * to updated it before every ioctl.
1521 if (file
->f_flags
& O_NDELAY
)
1522 mode
|= FMODE_NDELAY
;
1524 mode
&= ~FMODE_NDELAY
;
1526 return blkdev_ioctl(bdev
, mode
, cmd
, arg
);
1530 * Write data to the block device. Only intended for the block device itself
1531 * and the raw driver which basically is a fake block device.
1533 * Does not take i_mutex for the write and thus is not for general purpose
1536 ssize_t
blkdev_aio_write(struct kiocb
*iocb
, const struct iovec
*iov
,
1537 unsigned long nr_segs
, loff_t pos
)
1539 struct file
*file
= iocb
->ki_filp
;
1540 struct blk_plug plug
;
1543 BUG_ON(iocb
->ki_pos
!= pos
);
1545 blk_start_plug(&plug
);
1546 ret
= __generic_file_aio_write(iocb
, iov
, nr_segs
, &iocb
->ki_pos
);
1547 if (ret
> 0 || ret
== -EIOCBQUEUED
) {
1550 err
= generic_write_sync(file
, pos
, ret
);
1551 if (err
< 0 && ret
> 0)
1554 blk_finish_plug(&plug
);
1557 EXPORT_SYMBOL_GPL(blkdev_aio_write
);
1559 static ssize_t
blkdev_aio_read(struct kiocb
*iocb
, const struct iovec
*iov
,
1560 unsigned long nr_segs
, loff_t pos
)
1562 struct file
*file
= iocb
->ki_filp
;
1563 struct inode
*bd_inode
= file
->f_mapping
->host
;
1564 loff_t size
= i_size_read(bd_inode
);
1570 if (size
< iocb
->ki_left
)
1571 nr_segs
= iov_shorten((struct iovec
*)iov
, nr_segs
, size
);
1572 return generic_file_aio_read(iocb
, iov
, nr_segs
, pos
);
1576 * Try to release a page associated with block device when the system
1577 * is under memory pressure.
1579 static int blkdev_releasepage(struct page
*page
, gfp_t wait
)
1581 struct super_block
*super
= BDEV_I(page
->mapping
->host
)->bdev
.bd_super
;
1583 if (super
&& super
->s_op
->bdev_try_to_free_page
)
1584 return super
->s_op
->bdev_try_to_free_page(super
, page
, wait
);
1586 return try_to_free_buffers(page
);
1589 static const struct address_space_operations def_blk_aops
= {
1590 .readpage
= blkdev_readpage
,
1591 .writepage
= blkdev_writepage
,
1592 .write_begin
= blkdev_write_begin
,
1593 .write_end
= blkdev_write_end
,
1594 .writepages
= generic_writepages
,
1595 .releasepage
= blkdev_releasepage
,
1596 .direct_IO
= blkdev_direct_IO
,
1599 const struct file_operations def_blk_fops
= {
1600 .open
= blkdev_open
,
1601 .release
= blkdev_close
,
1602 .llseek
= block_llseek
,
1603 .read
= do_sync_read
,
1604 .write
= do_sync_write
,
1605 .aio_read
= blkdev_aio_read
,
1606 .aio_write
= blkdev_aio_write
,
1607 .mmap
= generic_file_mmap
,
1608 .fsync
= blkdev_fsync
,
1609 .unlocked_ioctl
= block_ioctl
,
1610 #ifdef CONFIG_COMPAT
1611 .compat_ioctl
= compat_blkdev_ioctl
,
1613 .splice_read
= generic_file_splice_read
,
1614 .splice_write
= generic_file_splice_write
,
1617 int ioctl_by_bdev(struct block_device
*bdev
, unsigned cmd
, unsigned long arg
)
1620 mm_segment_t old_fs
= get_fs();
1622 res
= blkdev_ioctl(bdev
, 0, cmd
, arg
);
1627 EXPORT_SYMBOL(ioctl_by_bdev
);
1630 * lookup_bdev - lookup a struct block_device by name
1631 * @pathname: special file representing the block device
1633 * Get a reference to the blockdevice at @pathname in the current
1634 * namespace if possible and return it. Return ERR_PTR(error)
1637 struct block_device
*lookup_bdev(const char *pathname
)
1639 struct block_device
*bdev
;
1640 struct inode
*inode
;
1644 if (!pathname
|| !*pathname
)
1645 return ERR_PTR(-EINVAL
);
1647 error
= kern_path(pathname
, LOOKUP_FOLLOW
, &path
);
1649 return ERR_PTR(error
);
1651 inode
= path
.dentry
->d_inode
;
1653 if (!S_ISBLK(inode
->i_mode
))
1656 if (path
.mnt
->mnt_flags
& MNT_NODEV
)
1659 bdev
= bd_acquire(inode
);
1666 bdev
= ERR_PTR(error
);
1669 EXPORT_SYMBOL(lookup_bdev
);
1671 int __invalidate_device(struct block_device
*bdev
, bool kill_dirty
)
1673 struct super_block
*sb
= get_super(bdev
);
1678 * no need to lock the super, get_super holds the
1679 * read mutex so the filesystem cannot go away
1680 * under us (->put_super runs with the write lock
1683 shrink_dcache_sb(sb
);
1684 res
= invalidate_inodes(sb
, kill_dirty
);
1687 invalidate_bdev(bdev
);
1690 EXPORT_SYMBOL(__invalidate_device
);
1692 void iterate_bdevs(void (*func
)(struct block_device
*, void *), void *arg
)
1694 struct inode
*inode
, *old_inode
= NULL
;
1696 spin_lock(&inode_sb_list_lock
);
1697 list_for_each_entry(inode
, &blockdev_superblock
->s_inodes
, i_sb_list
) {
1698 struct address_space
*mapping
= inode
->i_mapping
;
1699 struct block_device
*bdev
;
1701 spin_lock(&inode
->i_lock
);
1702 if (inode
->i_state
& (I_FREEING
|I_WILL_FREE
|I_NEW
) ||
1703 mapping
->nrpages
== 0) {
1704 spin_unlock(&inode
->i_lock
);
1708 spin_unlock(&inode
->i_lock
);
1709 spin_unlock(&inode_sb_list_lock
);
1711 * We hold a reference to 'inode' so it couldn't have been
1712 * removed from s_inodes list while we dropped the
1713 * inode_sb_list_lock. We cannot iput the inode now as we can
1714 * be holding the last reference and we cannot iput it under
1715 * inode_sb_list_lock. So we keep the reference and iput it
1720 bdev
= I_BDEV(inode
);
1722 mutex_lock(&bdev
->bd_mutex
);
1723 if (bdev
->bd_openers
)
1725 mutex_unlock(&bdev
->bd_mutex
);
1727 spin_lock(&inode_sb_list_lock
);
1729 spin_unlock(&inode_sb_list_lock
);