1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
5 * Copyright (C) 2016 - 2020 Christoph Hellwig
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/backing-dev.h>
18 #include <linux/module.h>
19 #include <linux/blkpg.h>
20 #include <linux/magic.h>
21 #include <linux/buffer_head.h>
22 #include <linux/swap.h>
23 #include <linux/pagevec.h>
24 #include <linux/writeback.h>
25 #include <linux/mpage.h>
26 #include <linux/mount.h>
27 #include <linux/pseudo_fs.h>
28 #include <linux/uio.h>
29 #include <linux/namei.h>
30 #include <linux/log2.h>
31 #include <linux/cleancache.h>
32 #include <linux/task_io_accounting_ops.h>
33 #include <linux/falloc.h>
34 #include <linux/part_stat.h>
35 #include <linux/uaccess.h>
36 #include <linux/suspend.h>
38 #include "../block/blk.h"
41 struct block_device bdev
;
42 struct inode vfs_inode
;
45 static const struct address_space_operations def_blk_aops
;
47 static inline struct bdev_inode
*BDEV_I(struct inode
*inode
)
49 return container_of(inode
, struct bdev_inode
, vfs_inode
);
52 struct block_device
*I_BDEV(struct inode
*inode
)
54 return &BDEV_I(inode
)->bdev
;
56 EXPORT_SYMBOL(I_BDEV
);
58 static void bdev_write_inode(struct block_device
*bdev
)
60 struct inode
*inode
= bdev
->bd_inode
;
63 spin_lock(&inode
->i_lock
);
64 while (inode
->i_state
& I_DIRTY
) {
65 spin_unlock(&inode
->i_lock
);
66 ret
= write_inode_now(inode
, true);
68 char name
[BDEVNAME_SIZE
];
69 pr_warn_ratelimited("VFS: Dirty inode writeback failed "
70 "for block device %s (err=%d).\n",
71 bdevname(bdev
, name
), ret
);
73 spin_lock(&inode
->i_lock
);
75 spin_unlock(&inode
->i_lock
);
78 /* Kill _all_ buffers and pagecache , dirty or not.. */
79 static void kill_bdev(struct block_device
*bdev
)
81 struct address_space
*mapping
= bdev
->bd_inode
->i_mapping
;
83 if (mapping_empty(mapping
))
87 truncate_inode_pages(mapping
, 0);
90 /* Invalidate clean unused buffers and pagecache. */
91 void invalidate_bdev(struct block_device
*bdev
)
93 struct address_space
*mapping
= bdev
->bd_inode
->i_mapping
;
95 if (mapping
->nrpages
) {
97 lru_add_drain_all(); /* make sure all lru add caches are flushed */
98 invalidate_mapping_pages(mapping
, 0, -1);
100 /* 99% of the time, we don't need to flush the cleancache on the bdev.
101 * But, for the strange corners, lets be cautious
103 cleancache_invalidate_inode(mapping
);
105 EXPORT_SYMBOL(invalidate_bdev
);
108 * Drop all buffers & page cache for given bdev range. This function bails
109 * with error if bdev has other exclusive owner (such as filesystem).
111 int truncate_bdev_range(struct block_device
*bdev
, fmode_t mode
,
112 loff_t lstart
, loff_t lend
)
115 * If we don't hold exclusive handle for the device, upgrade to it
116 * while we discard the buffer cache to avoid discarding buffers
117 * under live filesystem.
119 if (!(mode
& FMODE_EXCL
)) {
120 int err
= bd_prepare_to_claim(bdev
, truncate_bdev_range
);
125 truncate_inode_pages_range(bdev
->bd_inode
->i_mapping
, lstart
, lend
);
126 if (!(mode
& FMODE_EXCL
))
127 bd_abort_claiming(bdev
, truncate_bdev_range
);
132 * Someone else has handle exclusively open. Try invalidating instead.
133 * The 'end' argument is inclusive so the rounding is safe.
135 return invalidate_inode_pages2_range(bdev
->bd_inode
->i_mapping
,
136 lstart
>> PAGE_SHIFT
,
140 static void set_init_blocksize(struct block_device
*bdev
)
142 unsigned int bsize
= bdev_logical_block_size(bdev
);
143 loff_t size
= i_size_read(bdev
->bd_inode
);
145 while (bsize
< PAGE_SIZE
) {
150 bdev
->bd_inode
->i_blkbits
= blksize_bits(bsize
);
153 int set_blocksize(struct block_device
*bdev
, int size
)
155 /* Size must be a power of two, and between 512 and PAGE_SIZE */
156 if (size
> PAGE_SIZE
|| size
< 512 || !is_power_of_2(size
))
159 /* Size cannot be smaller than the size supported by the device */
160 if (size
< bdev_logical_block_size(bdev
))
163 /* Don't change the size if it is same as current */
164 if (bdev
->bd_inode
->i_blkbits
!= blksize_bits(size
)) {
166 bdev
->bd_inode
->i_blkbits
= blksize_bits(size
);
172 EXPORT_SYMBOL(set_blocksize
);
174 int sb_set_blocksize(struct super_block
*sb
, int size
)
176 if (set_blocksize(sb
->s_bdev
, size
))
178 /* If we get here, we know size is power of two
179 * and it's value is between 512 and PAGE_SIZE */
180 sb
->s_blocksize
= size
;
181 sb
->s_blocksize_bits
= blksize_bits(size
);
182 return sb
->s_blocksize
;
185 EXPORT_SYMBOL(sb_set_blocksize
);
187 int sb_min_blocksize(struct super_block
*sb
, int size
)
189 int minsize
= bdev_logical_block_size(sb
->s_bdev
);
192 return sb_set_blocksize(sb
, size
);
195 EXPORT_SYMBOL(sb_min_blocksize
);
198 blkdev_get_block(struct inode
*inode
, sector_t iblock
,
199 struct buffer_head
*bh
, int create
)
201 bh
->b_bdev
= I_BDEV(inode
);
202 bh
->b_blocknr
= iblock
;
203 set_buffer_mapped(bh
);
207 static struct inode
*bdev_file_inode(struct file
*file
)
209 return file
->f_mapping
->host
;
212 static unsigned int dio_bio_write_op(struct kiocb
*iocb
)
214 unsigned int op
= REQ_OP_WRITE
| REQ_SYNC
| REQ_IDLE
;
216 /* avoid the need for a I/O completion work item */
217 if (iocb
->ki_flags
& IOCB_DSYNC
)
222 #define DIO_INLINE_BIO_VECS 4
224 static void blkdev_bio_end_io_simple(struct bio
*bio
)
226 struct task_struct
*waiter
= bio
->bi_private
;
228 WRITE_ONCE(bio
->bi_private
, NULL
);
229 blk_wake_io_task(waiter
);
233 __blkdev_direct_IO_simple(struct kiocb
*iocb
, struct iov_iter
*iter
,
234 unsigned int nr_pages
)
236 struct file
*file
= iocb
->ki_filp
;
237 struct block_device
*bdev
= I_BDEV(bdev_file_inode(file
));
238 struct bio_vec inline_vecs
[DIO_INLINE_BIO_VECS
], *vecs
;
239 loff_t pos
= iocb
->ki_pos
;
240 bool should_dirty
= false;
245 if ((pos
| iov_iter_alignment(iter
)) &
246 (bdev_logical_block_size(bdev
) - 1))
249 if (nr_pages
<= DIO_INLINE_BIO_VECS
)
252 vecs
= kmalloc_array(nr_pages
, sizeof(struct bio_vec
),
258 bio_init(&bio
, vecs
, nr_pages
);
259 bio_set_dev(&bio
, bdev
);
260 bio
.bi_iter
.bi_sector
= pos
>> 9;
261 bio
.bi_write_hint
= iocb
->ki_hint
;
262 bio
.bi_private
= current
;
263 bio
.bi_end_io
= blkdev_bio_end_io_simple
;
264 bio
.bi_ioprio
= iocb
->ki_ioprio
;
266 ret
= bio_iov_iter_get_pages(&bio
, iter
);
269 ret
= bio
.bi_iter
.bi_size
;
271 if (iov_iter_rw(iter
) == READ
) {
272 bio
.bi_opf
= REQ_OP_READ
;
273 if (iter_is_iovec(iter
))
276 bio
.bi_opf
= dio_bio_write_op(iocb
);
277 task_io_account_write(ret
);
279 if (iocb
->ki_flags
& IOCB_NOWAIT
)
280 bio
.bi_opf
|= REQ_NOWAIT
;
281 if (iocb
->ki_flags
& IOCB_HIPRI
)
282 bio_set_polled(&bio
, iocb
);
284 qc
= submit_bio(&bio
);
286 set_current_state(TASK_UNINTERRUPTIBLE
);
287 if (!READ_ONCE(bio
.bi_private
))
289 if (!(iocb
->ki_flags
& IOCB_HIPRI
) ||
290 !blk_poll(bdev_get_queue(bdev
), qc
, true))
293 __set_current_state(TASK_RUNNING
);
295 bio_release_pages(&bio
, should_dirty
);
296 if (unlikely(bio
.bi_status
))
297 ret
= blk_status_to_errno(bio
.bi_status
);
300 if (vecs
!= inline_vecs
)
311 struct task_struct
*waiter
;
316 bool should_dirty
: 1;
321 static struct bio_set blkdev_dio_pool
;
323 static int blkdev_iopoll(struct kiocb
*kiocb
, bool wait
)
325 struct block_device
*bdev
= I_BDEV(kiocb
->ki_filp
->f_mapping
->host
);
326 struct request_queue
*q
= bdev_get_queue(bdev
);
328 return blk_poll(q
, READ_ONCE(kiocb
->ki_cookie
), wait
);
331 static void blkdev_bio_end_io(struct bio
*bio
)
333 struct blkdev_dio
*dio
= bio
->bi_private
;
334 bool should_dirty
= dio
->should_dirty
;
336 if (bio
->bi_status
&& !dio
->bio
.bi_status
)
337 dio
->bio
.bi_status
= bio
->bi_status
;
339 if (!dio
->multi_bio
|| atomic_dec_and_test(&dio
->ref
)) {
341 struct kiocb
*iocb
= dio
->iocb
;
344 if (likely(!dio
->bio
.bi_status
)) {
348 ret
= blk_status_to_errno(dio
->bio
.bi_status
);
351 dio
->iocb
->ki_complete(iocb
, ret
, 0);
355 struct task_struct
*waiter
= dio
->waiter
;
357 WRITE_ONCE(dio
->waiter
, NULL
);
358 blk_wake_io_task(waiter
);
363 bio_check_pages_dirty(bio
);
365 bio_release_pages(bio
, false);
370 static ssize_t
__blkdev_direct_IO(struct kiocb
*iocb
, struct iov_iter
*iter
,
371 unsigned int nr_pages
)
373 struct file
*file
= iocb
->ki_filp
;
374 struct inode
*inode
= bdev_file_inode(file
);
375 struct block_device
*bdev
= I_BDEV(inode
);
376 struct blk_plug plug
;
377 struct blkdev_dio
*dio
;
379 bool is_poll
= (iocb
->ki_flags
& IOCB_HIPRI
) != 0;
380 bool is_read
= (iov_iter_rw(iter
) == READ
), is_sync
;
381 loff_t pos
= iocb
->ki_pos
;
382 blk_qc_t qc
= BLK_QC_T_NONE
;
385 if ((pos
| iov_iter_alignment(iter
)) &
386 (bdev_logical_block_size(bdev
) - 1))
389 bio
= bio_alloc_kiocb(iocb
, nr_pages
, &blkdev_dio_pool
);
391 dio
= container_of(bio
, struct blkdev_dio
, bio
);
392 dio
->is_sync
= is_sync
= is_sync_kiocb(iocb
);
394 dio
->waiter
= current
;
401 dio
->multi_bio
= false;
402 dio
->should_dirty
= is_read
&& iter_is_iovec(iter
);
405 * Don't plug for HIPRI/polled IO, as those should go straight
409 blk_start_plug(&plug
);
412 bio_set_dev(bio
, bdev
);
413 bio
->bi_iter
.bi_sector
= pos
>> 9;
414 bio
->bi_write_hint
= iocb
->ki_hint
;
415 bio
->bi_private
= dio
;
416 bio
->bi_end_io
= blkdev_bio_end_io
;
417 bio
->bi_ioprio
= iocb
->ki_ioprio
;
419 ret
= bio_iov_iter_get_pages(bio
, iter
);
421 bio
->bi_status
= BLK_STS_IOERR
;
427 bio
->bi_opf
= REQ_OP_READ
;
428 if (dio
->should_dirty
)
429 bio_set_pages_dirty(bio
);
431 bio
->bi_opf
= dio_bio_write_op(iocb
);
432 task_io_account_write(bio
->bi_iter
.bi_size
);
434 if (iocb
->ki_flags
& IOCB_NOWAIT
)
435 bio
->bi_opf
|= REQ_NOWAIT
;
437 dio
->size
+= bio
->bi_iter
.bi_size
;
438 pos
+= bio
->bi_iter
.bi_size
;
440 nr_pages
= bio_iov_vecs_to_alloc(iter
, BIO_MAX_VECS
);
444 if (iocb
->ki_flags
& IOCB_HIPRI
) {
445 bio_set_polled(bio
, iocb
);
449 qc
= submit_bio(bio
);
452 WRITE_ONCE(iocb
->ki_cookie
, qc
);
456 if (!dio
->multi_bio
) {
458 * AIO needs an extra reference to ensure the dio
459 * structure which is embedded into the first bio
464 dio
->multi_bio
= true;
465 atomic_set(&dio
->ref
, 2);
467 atomic_inc(&dio
->ref
);
471 bio
= bio_alloc(GFP_KERNEL
, nr_pages
);
475 blk_finish_plug(&plug
);
481 set_current_state(TASK_UNINTERRUPTIBLE
);
482 if (!READ_ONCE(dio
->waiter
))
485 if (!(iocb
->ki_flags
& IOCB_HIPRI
) ||
486 !blk_poll(bdev_get_queue(bdev
), qc
, true))
489 __set_current_state(TASK_RUNNING
);
492 ret
= blk_status_to_errno(dio
->bio
.bi_status
);
501 blkdev_direct_IO(struct kiocb
*iocb
, struct iov_iter
*iter
)
503 unsigned int nr_pages
;
505 if (!iov_iter_count(iter
))
508 nr_pages
= bio_iov_vecs_to_alloc(iter
, BIO_MAX_VECS
+ 1);
509 if (is_sync_kiocb(iocb
) && nr_pages
<= BIO_MAX_VECS
)
510 return __blkdev_direct_IO_simple(iocb
, iter
, nr_pages
);
512 return __blkdev_direct_IO(iocb
, iter
, bio_max_segs(nr_pages
));
515 static __init
int blkdev_init(void)
517 return bioset_init(&blkdev_dio_pool
, 4,
518 offsetof(struct blkdev_dio
, bio
),
519 BIOSET_NEED_BVECS
|BIOSET_PERCPU_CACHE
);
521 module_init(blkdev_init
);
523 int __sync_blockdev(struct block_device
*bdev
, int wait
)
528 return filemap_flush(bdev
->bd_inode
->i_mapping
);
529 return filemap_write_and_wait(bdev
->bd_inode
->i_mapping
);
533 * Write out and wait upon all the dirty data associated with a block
534 * device via its mapping. Does not take the superblock lock.
536 int sync_blockdev(struct block_device
*bdev
)
538 return __sync_blockdev(bdev
, 1);
540 EXPORT_SYMBOL(sync_blockdev
);
543 * Write out and wait upon all dirty data associated with this
544 * device. Filesystem data as well as the underlying block
545 * device. Takes the superblock lock.
547 int fsync_bdev(struct block_device
*bdev
)
549 struct super_block
*sb
= get_super(bdev
);
551 int res
= sync_filesystem(sb
);
555 return sync_blockdev(bdev
);
557 EXPORT_SYMBOL(fsync_bdev
);
560 * freeze_bdev -- lock a filesystem and force it into a consistent state
561 * @bdev: blockdevice to lock
563 * If a superblock is found on this device, we take the s_umount semaphore
564 * on it to make sure nobody unmounts until the snapshot creation is done.
565 * The reference counter (bd_fsfreeze_count) guarantees that only the last
566 * unfreeze process can unfreeze the frozen filesystem actually when multiple
567 * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
568 * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
571 int freeze_bdev(struct block_device
*bdev
)
573 struct super_block
*sb
;
576 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
577 if (++bdev
->bd_fsfreeze_count
> 1)
580 sb
= get_active_super(bdev
);
583 if (sb
->s_op
->freeze_super
)
584 error
= sb
->s_op
->freeze_super(sb
);
586 error
= freeze_super(sb
);
587 deactivate_super(sb
);
590 bdev
->bd_fsfreeze_count
--;
593 bdev
->bd_fsfreeze_sb
= sb
;
598 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
601 EXPORT_SYMBOL(freeze_bdev
);
604 * thaw_bdev -- unlock filesystem
605 * @bdev: blockdevice to unlock
607 * Unlocks the filesystem and marks it writeable again after freeze_bdev().
609 int thaw_bdev(struct block_device
*bdev
)
611 struct super_block
*sb
;
614 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
615 if (!bdev
->bd_fsfreeze_count
)
619 if (--bdev
->bd_fsfreeze_count
> 0)
622 sb
= bdev
->bd_fsfreeze_sb
;
626 if (sb
->s_op
->thaw_super
)
627 error
= sb
->s_op
->thaw_super(sb
);
629 error
= thaw_super(sb
);
631 bdev
->bd_fsfreeze_count
++;
633 bdev
->bd_fsfreeze_sb
= NULL
;
635 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
638 EXPORT_SYMBOL(thaw_bdev
);
640 static int blkdev_writepage(struct page
*page
, struct writeback_control
*wbc
)
642 return block_write_full_page(page
, blkdev_get_block
, wbc
);
645 static int blkdev_readpage(struct file
* file
, struct page
* page
)
647 return block_read_full_page(page
, blkdev_get_block
);
650 static void blkdev_readahead(struct readahead_control
*rac
)
652 mpage_readahead(rac
, blkdev_get_block
);
655 static int blkdev_write_begin(struct file
*file
, struct address_space
*mapping
,
656 loff_t pos
, unsigned len
, unsigned flags
,
657 struct page
**pagep
, void **fsdata
)
659 return block_write_begin(mapping
, pos
, len
, flags
, pagep
,
663 static int blkdev_write_end(struct file
*file
, struct address_space
*mapping
,
664 loff_t pos
, unsigned len
, unsigned copied
,
665 struct page
*page
, void *fsdata
)
668 ret
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
678 * for a block special file file_inode(file)->i_size is zero
679 * so we compute the size by hand (just as in block_read/write above)
681 static loff_t
block_llseek(struct file
*file
, loff_t offset
, int whence
)
683 struct inode
*bd_inode
= bdev_file_inode(file
);
686 inode_lock(bd_inode
);
687 retval
= fixed_size_llseek(file
, offset
, whence
, i_size_read(bd_inode
));
688 inode_unlock(bd_inode
);
692 static int blkdev_fsync(struct file
*filp
, loff_t start
, loff_t end
,
695 struct inode
*bd_inode
= bdev_file_inode(filp
);
696 struct block_device
*bdev
= I_BDEV(bd_inode
);
699 error
= file_write_and_wait_range(filp
, start
, end
);
704 * There is no need to serialise calls to blkdev_issue_flush with
705 * i_mutex and doing so causes performance issues with concurrent
706 * O_SYNC writers to a block device.
708 error
= blkdev_issue_flush(bdev
);
709 if (error
== -EOPNOTSUPP
)
716 * bdev_read_page() - Start reading a page from a block device
717 * @bdev: The device to read the page from
718 * @sector: The offset on the device to read the page to (need not be aligned)
719 * @page: The page to read
721 * On entry, the page should be locked. It will be unlocked when the page
722 * has been read. If the block driver implements rw_page synchronously,
723 * that will be true on exit from this function, but it need not be.
725 * Errors returned by this function are usually "soft", eg out of memory, or
726 * queue full; callers should try a different route to read this page rather
727 * than propagate an error back up the stack.
729 * Return: negative errno if an error occurs, 0 if submission was successful.
731 int bdev_read_page(struct block_device
*bdev
, sector_t sector
,
734 const struct block_device_operations
*ops
= bdev
->bd_disk
->fops
;
735 int result
= -EOPNOTSUPP
;
737 if (!ops
->rw_page
|| bdev_get_integrity(bdev
))
740 result
= blk_queue_enter(bdev
->bd_disk
->queue
, 0);
743 result
= ops
->rw_page(bdev
, sector
+ get_start_sect(bdev
), page
,
745 blk_queue_exit(bdev
->bd_disk
->queue
);
750 * bdev_write_page() - Start writing a page to a block device
751 * @bdev: The device to write the page to
752 * @sector: The offset on the device to write the page to (need not be aligned)
753 * @page: The page to write
754 * @wbc: The writeback_control for the write
756 * On entry, the page should be locked and not currently under writeback.
757 * On exit, if the write started successfully, the page will be unlocked and
758 * under writeback. If the write failed already (eg the driver failed to
759 * queue the page to the device), the page will still be locked. If the
760 * caller is a ->writepage implementation, it will need to unlock the page.
762 * Errors returned by this function are usually "soft", eg out of memory, or
763 * queue full; callers should try a different route to write this page rather
764 * than propagate an error back up the stack.
766 * Return: negative errno if an error occurs, 0 if submission was successful.
768 int bdev_write_page(struct block_device
*bdev
, sector_t sector
,
769 struct page
*page
, struct writeback_control
*wbc
)
772 const struct block_device_operations
*ops
= bdev
->bd_disk
->fops
;
774 if (!ops
->rw_page
|| bdev_get_integrity(bdev
))
776 result
= blk_queue_enter(bdev
->bd_disk
->queue
, 0);
780 set_page_writeback(page
);
781 result
= ops
->rw_page(bdev
, sector
+ get_start_sect(bdev
), page
,
784 end_page_writeback(page
);
786 clean_page_buffers(page
);
789 blk_queue_exit(bdev
->bd_disk
->queue
);
797 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(bdev_lock
);
798 static struct kmem_cache
* bdev_cachep __read_mostly
;
800 static struct inode
*bdev_alloc_inode(struct super_block
*sb
)
802 struct bdev_inode
*ei
= kmem_cache_alloc(bdev_cachep
, GFP_KERNEL
);
806 memset(&ei
->bdev
, 0, sizeof(ei
->bdev
));
807 return &ei
->vfs_inode
;
810 static void bdev_free_inode(struct inode
*inode
)
812 struct block_device
*bdev
= I_BDEV(inode
);
814 free_percpu(bdev
->bd_stats
);
815 kfree(bdev
->bd_meta_info
);
817 if (!bdev_is_partition(bdev
)) {
818 if (bdev
->bd_disk
&& bdev
->bd_disk
->bdi
)
819 bdi_put(bdev
->bd_disk
->bdi
);
820 kfree(bdev
->bd_disk
);
823 if (MAJOR(bdev
->bd_dev
) == BLOCK_EXT_MAJOR
)
824 blk_free_ext_minor(MINOR(bdev
->bd_dev
));
826 kmem_cache_free(bdev_cachep
, BDEV_I(inode
));
829 static void init_once(void *data
)
831 struct bdev_inode
*ei
= data
;
833 inode_init_once(&ei
->vfs_inode
);
836 static void bdev_evict_inode(struct inode
*inode
)
838 truncate_inode_pages_final(&inode
->i_data
);
839 invalidate_inode_buffers(inode
); /* is it needed here? */
843 static const struct super_operations bdev_sops
= {
844 .statfs
= simple_statfs
,
845 .alloc_inode
= bdev_alloc_inode
,
846 .free_inode
= bdev_free_inode
,
847 .drop_inode
= generic_delete_inode
,
848 .evict_inode
= bdev_evict_inode
,
851 static int bd_init_fs_context(struct fs_context
*fc
)
853 struct pseudo_fs_context
*ctx
= init_pseudo(fc
, BDEVFS_MAGIC
);
856 fc
->s_iflags
|= SB_I_CGROUPWB
;
857 ctx
->ops
= &bdev_sops
;
861 static struct file_system_type bd_type
= {
863 .init_fs_context
= bd_init_fs_context
,
864 .kill_sb
= kill_anon_super
,
867 struct super_block
*blockdev_superblock __read_mostly
;
868 EXPORT_SYMBOL_GPL(blockdev_superblock
);
870 void __init
bdev_cache_init(void)
873 static struct vfsmount
*bd_mnt
;
875 bdev_cachep
= kmem_cache_create("bdev_cache", sizeof(struct bdev_inode
),
876 0, (SLAB_HWCACHE_ALIGN
|SLAB_RECLAIM_ACCOUNT
|
877 SLAB_MEM_SPREAD
|SLAB_ACCOUNT
|SLAB_PANIC
),
879 err
= register_filesystem(&bd_type
);
881 panic("Cannot register bdev pseudo-fs");
882 bd_mnt
= kern_mount(&bd_type
);
884 panic("Cannot create bdev pseudo-fs");
885 blockdev_superblock
= bd_mnt
->mnt_sb
; /* For writeback */
888 struct block_device
*bdev_alloc(struct gendisk
*disk
, u8 partno
)
890 struct block_device
*bdev
;
893 inode
= new_inode(blockdev_superblock
);
896 inode
->i_mode
= S_IFBLK
;
898 inode
->i_data
.a_ops
= &def_blk_aops
;
899 mapping_set_gfp_mask(&inode
->i_data
, GFP_USER
);
901 bdev
= I_BDEV(inode
);
902 mutex_init(&bdev
->bd_fsfreeze_mutex
);
903 spin_lock_init(&bdev
->bd_size_lock
);
904 bdev
->bd_disk
= disk
;
905 bdev
->bd_partno
= partno
;
906 bdev
->bd_inode
= inode
;
907 bdev
->bd_stats
= alloc_percpu(struct disk_stats
);
908 if (!bdev
->bd_stats
) {
915 void bdev_add(struct block_device
*bdev
, dev_t dev
)
918 bdev
->bd_inode
->i_rdev
= dev
;
919 bdev
->bd_inode
->i_ino
= dev
;
920 insert_inode_hash(bdev
->bd_inode
);
923 long nr_blockdev_pages(void)
928 spin_lock(&blockdev_superblock
->s_inode_list_lock
);
929 list_for_each_entry(inode
, &blockdev_superblock
->s_inodes
, i_sb_list
)
930 ret
+= inode
->i_mapping
->nrpages
;
931 spin_unlock(&blockdev_superblock
->s_inode_list_lock
);
937 * bd_may_claim - test whether a block device can be claimed
938 * @bdev: block device of interest
939 * @whole: whole block device containing @bdev, may equal @bdev
940 * @holder: holder trying to claim @bdev
942 * Test whether @bdev can be claimed by @holder.
945 * spin_lock(&bdev_lock).
948 * %true if @bdev can be claimed, %false otherwise.
950 static bool bd_may_claim(struct block_device
*bdev
, struct block_device
*whole
,
953 if (bdev
->bd_holder
== holder
)
954 return true; /* already a holder */
955 else if (bdev
->bd_holder
!= NULL
)
956 return false; /* held by someone else */
957 else if (whole
== bdev
)
958 return true; /* is a whole device which isn't held */
960 else if (whole
->bd_holder
== bd_may_claim
)
961 return true; /* is a partition of a device that is being partitioned */
962 else if (whole
->bd_holder
!= NULL
)
963 return false; /* is a partition of a held device */
965 return true; /* is a partition of an un-held device */
969 * bd_prepare_to_claim - claim a block device
970 * @bdev: block device of interest
971 * @holder: holder trying to claim @bdev
973 * Claim @bdev. This function fails if @bdev is already claimed by another
974 * holder and waits if another claiming is in progress. return, the caller
975 * has ownership of bd_claiming and bd_holder[s].
978 * 0 if @bdev can be claimed, -EBUSY otherwise.
980 int bd_prepare_to_claim(struct block_device
*bdev
, void *holder
)
982 struct block_device
*whole
= bdev_whole(bdev
);
984 if (WARN_ON_ONCE(!holder
))
987 spin_lock(&bdev_lock
);
988 /* if someone else claimed, fail */
989 if (!bd_may_claim(bdev
, whole
, holder
)) {
990 spin_unlock(&bdev_lock
);
994 /* if claiming is already in progress, wait for it to finish */
995 if (whole
->bd_claiming
) {
996 wait_queue_head_t
*wq
= bit_waitqueue(&whole
->bd_claiming
, 0);
999 prepare_to_wait(wq
, &wait
, TASK_UNINTERRUPTIBLE
);
1000 spin_unlock(&bdev_lock
);
1002 finish_wait(wq
, &wait
);
1007 whole
->bd_claiming
= holder
;
1008 spin_unlock(&bdev_lock
);
1011 EXPORT_SYMBOL_GPL(bd_prepare_to_claim
); /* only for the loop driver */
1013 static void bd_clear_claiming(struct block_device
*whole
, void *holder
)
1015 lockdep_assert_held(&bdev_lock
);
1016 /* tell others that we're done */
1017 BUG_ON(whole
->bd_claiming
!= holder
);
1018 whole
->bd_claiming
= NULL
;
1019 wake_up_bit(&whole
->bd_claiming
, 0);
1023 * bd_finish_claiming - finish claiming of a block device
1024 * @bdev: block device of interest
1025 * @holder: holder that has claimed @bdev
1027 * Finish exclusive open of a block device. Mark the device as exlusively
1028 * open by the holder and wake up all waiters for exclusive open to finish.
1030 static void bd_finish_claiming(struct block_device
*bdev
, void *holder
)
1032 struct block_device
*whole
= bdev_whole(bdev
);
1034 spin_lock(&bdev_lock
);
1035 BUG_ON(!bd_may_claim(bdev
, whole
, holder
));
1037 * Note that for a whole device bd_holders will be incremented twice,
1038 * and bd_holder will be set to bd_may_claim before being set to holder
1040 whole
->bd_holders
++;
1041 whole
->bd_holder
= bd_may_claim
;
1043 bdev
->bd_holder
= holder
;
1044 bd_clear_claiming(whole
, holder
);
1045 spin_unlock(&bdev_lock
);
1049 * bd_abort_claiming - abort claiming of a block device
1050 * @bdev: block device of interest
1051 * @holder: holder that has claimed @bdev
1053 * Abort claiming of a block device when the exclusive open failed. This can be
1054 * also used when exclusive open is not actually desired and we just needed
1055 * to block other exclusive openers for a while.
1057 void bd_abort_claiming(struct block_device
*bdev
, void *holder
)
1059 spin_lock(&bdev_lock
);
1060 bd_clear_claiming(bdev_whole(bdev
), holder
);
1061 spin_unlock(&bdev_lock
);
1063 EXPORT_SYMBOL(bd_abort_claiming
);
1065 static void blkdev_flush_mapping(struct block_device
*bdev
)
1067 WARN_ON_ONCE(bdev
->bd_holders
);
1068 sync_blockdev(bdev
);
1070 bdev_write_inode(bdev
);
1073 static int blkdev_get_whole(struct block_device
*bdev
, fmode_t mode
)
1075 struct gendisk
*disk
= bdev
->bd_disk
;
1078 if (disk
->fops
->open
) {
1079 ret
= disk
->fops
->open(bdev
, mode
);
1081 /* avoid ghost partitions on a removed medium */
1082 if (ret
== -ENOMEDIUM
&&
1083 test_bit(GD_NEED_PART_SCAN
, &disk
->state
))
1084 bdev_disk_changed(disk
, true);
1089 if (!bdev
->bd_openers
)
1090 set_init_blocksize(bdev
);
1091 if (test_bit(GD_NEED_PART_SCAN
, &disk
->state
))
1092 bdev_disk_changed(disk
, false);
1097 static void blkdev_put_whole(struct block_device
*bdev
, fmode_t mode
)
1099 if (!--bdev
->bd_openers
)
1100 blkdev_flush_mapping(bdev
);
1101 if (bdev
->bd_disk
->fops
->release
)
1102 bdev
->bd_disk
->fops
->release(bdev
->bd_disk
, mode
);
1105 static int blkdev_get_part(struct block_device
*part
, fmode_t mode
)
1107 struct gendisk
*disk
= part
->bd_disk
;
1110 if (part
->bd_openers
)
1113 ret
= blkdev_get_whole(bdev_whole(part
), mode
);
1118 if (!bdev_nr_sectors(part
))
1119 goto out_blkdev_put
;
1121 disk
->open_partitions
++;
1122 set_init_blocksize(part
);
1128 blkdev_put_whole(bdev_whole(part
), mode
);
1132 static void blkdev_put_part(struct block_device
*part
, fmode_t mode
)
1134 struct block_device
*whole
= bdev_whole(part
);
1136 if (--part
->bd_openers
)
1138 blkdev_flush_mapping(part
);
1139 whole
->bd_disk
->open_partitions
--;
1140 blkdev_put_whole(whole
, mode
);
1143 struct block_device
*blkdev_get_no_open(dev_t dev
)
1145 struct block_device
*bdev
;
1146 struct inode
*inode
;
1148 inode
= ilookup(blockdev_superblock
, dev
);
1150 blk_request_module(dev
);
1151 inode
= ilookup(blockdev_superblock
, dev
);
1156 /* switch from the inode reference to a device mode one: */
1157 bdev
= &BDEV_I(inode
)->bdev
;
1158 if (!kobject_get_unless_zero(&bdev
->bd_device
.kobj
))
1164 if ((bdev
->bd_disk
->flags
& GENHD_FL_HIDDEN
) ||
1165 !try_module_get(bdev
->bd_disk
->fops
->owner
)) {
1166 put_device(&bdev
->bd_device
);
1173 void blkdev_put_no_open(struct block_device
*bdev
)
1175 module_put(bdev
->bd_disk
->fops
->owner
);
1176 put_device(&bdev
->bd_device
);
1180 * blkdev_get_by_dev - open a block device by device number
1181 * @dev: device number of block device to open
1182 * @mode: FMODE_* mask
1183 * @holder: exclusive holder identifier
1185 * Open the block device described by device number @dev. If @mode includes
1186 * %FMODE_EXCL, the block device is opened with exclusive access. Specifying
1187 * %FMODE_EXCL with a %NULL @holder is invalid. Exclusive opens may nest for
1190 * Use this interface ONLY if you really do not have anything better - i.e. when
1191 * you are behind a truly sucky interface and all you are given is a device
1192 * number. Everything else should use blkdev_get_by_path().
1198 * Reference to the block_device on success, ERR_PTR(-errno) on failure.
1200 struct block_device
*blkdev_get_by_dev(dev_t dev
, fmode_t mode
, void *holder
)
1202 bool unblock_events
= true;
1203 struct block_device
*bdev
;
1204 struct gendisk
*disk
;
1207 ret
= devcgroup_check_permission(DEVCG_DEV_BLOCK
,
1208 MAJOR(dev
), MINOR(dev
),
1209 ((mode
& FMODE_READ
) ? DEVCG_ACC_READ
: 0) |
1210 ((mode
& FMODE_WRITE
) ? DEVCG_ACC_WRITE
: 0));
1212 return ERR_PTR(ret
);
1214 bdev
= blkdev_get_no_open(dev
);
1216 return ERR_PTR(-ENXIO
);
1217 disk
= bdev
->bd_disk
;
1219 if (mode
& FMODE_EXCL
) {
1220 ret
= bd_prepare_to_claim(bdev
, holder
);
1225 disk_block_events(disk
);
1227 mutex_lock(&disk
->open_mutex
);
1229 if (!disk_live(disk
))
1230 goto abort_claiming
;
1231 if (bdev_is_partition(bdev
))
1232 ret
= blkdev_get_part(bdev
, mode
);
1234 ret
= blkdev_get_whole(bdev
, mode
);
1236 goto abort_claiming
;
1237 if (mode
& FMODE_EXCL
) {
1238 bd_finish_claiming(bdev
, holder
);
1241 * Block event polling for write claims if requested. Any write
1242 * holder makes the write_holder state stick until all are
1243 * released. This is good enough and tracking individual
1244 * writeable reference is too fragile given the way @mode is
1245 * used in blkdev_get/put().
1247 if ((mode
& FMODE_WRITE
) && !bdev
->bd_write_holder
&&
1248 (disk
->flags
& GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE
)) {
1249 bdev
->bd_write_holder
= true;
1250 unblock_events
= false;
1253 mutex_unlock(&disk
->open_mutex
);
1256 disk_unblock_events(disk
);
1260 if (mode
& FMODE_EXCL
)
1261 bd_abort_claiming(bdev
, holder
);
1262 mutex_unlock(&disk
->open_mutex
);
1263 disk_unblock_events(disk
);
1265 blkdev_put_no_open(bdev
);
1266 return ERR_PTR(ret
);
1268 EXPORT_SYMBOL(blkdev_get_by_dev
);
1271 * blkdev_get_by_path - open a block device by name
1272 * @path: path to the block device to open
1273 * @mode: FMODE_* mask
1274 * @holder: exclusive holder identifier
1276 * Open the block device described by the device file at @path. If @mode
1277 * includes %FMODE_EXCL, the block device is opened with exclusive access.
1278 * Specifying %FMODE_EXCL with a %NULL @holder is invalid. Exclusive opens may
1279 * nest for the same @holder.
1285 * Reference to the block_device on success, ERR_PTR(-errno) on failure.
1287 struct block_device
*blkdev_get_by_path(const char *path
, fmode_t mode
,
1290 struct block_device
*bdev
;
1294 error
= lookup_bdev(path
, &dev
);
1296 return ERR_PTR(error
);
1298 bdev
= blkdev_get_by_dev(dev
, mode
, holder
);
1299 if (!IS_ERR(bdev
) && (mode
& FMODE_WRITE
) && bdev_read_only(bdev
)) {
1300 blkdev_put(bdev
, mode
);
1301 return ERR_PTR(-EACCES
);
1306 EXPORT_SYMBOL(blkdev_get_by_path
);
1308 static int blkdev_open(struct inode
* inode
, struct file
* filp
)
1310 struct block_device
*bdev
;
1313 * Preserve backwards compatibility and allow large file access
1314 * even if userspace doesn't ask for it explicitly. Some mkfs
1315 * binary needs it. We might want to drop this workaround
1316 * during an unstable branch.
1318 filp
->f_flags
|= O_LARGEFILE
;
1320 filp
->f_mode
|= FMODE_NOWAIT
| FMODE_BUF_RASYNC
;
1322 if (filp
->f_flags
& O_NDELAY
)
1323 filp
->f_mode
|= FMODE_NDELAY
;
1324 if (filp
->f_flags
& O_EXCL
)
1325 filp
->f_mode
|= FMODE_EXCL
;
1326 if ((filp
->f_flags
& O_ACCMODE
) == 3)
1327 filp
->f_mode
|= FMODE_WRITE_IOCTL
;
1329 bdev
= blkdev_get_by_dev(inode
->i_rdev
, filp
->f_mode
, filp
);
1331 return PTR_ERR(bdev
);
1332 filp
->f_mapping
= bdev
->bd_inode
->i_mapping
;
1333 filp
->f_wb_err
= filemap_sample_wb_err(filp
->f_mapping
);
1337 void blkdev_put(struct block_device
*bdev
, fmode_t mode
)
1339 struct gendisk
*disk
= bdev
->bd_disk
;
1342 * Sync early if it looks like we're the last one. If someone else
1343 * opens the block device between now and the decrement of bd_openers
1344 * then we did a sync that we didn't need to, but that's not the end
1345 * of the world and we want to avoid long (could be several minute)
1346 * syncs while holding the mutex.
1348 if (bdev
->bd_openers
== 1)
1349 sync_blockdev(bdev
);
1351 mutex_lock(&disk
->open_mutex
);
1352 if (mode
& FMODE_EXCL
) {
1353 struct block_device
*whole
= bdev_whole(bdev
);
1357 * Release a claim on the device. The holder fields
1358 * are protected with bdev_lock. open_mutex is to
1359 * synchronize disk_holder unlinking.
1361 spin_lock(&bdev_lock
);
1363 WARN_ON_ONCE(--bdev
->bd_holders
< 0);
1364 WARN_ON_ONCE(--whole
->bd_holders
< 0);
1366 if ((bdev_free
= !bdev
->bd_holders
))
1367 bdev
->bd_holder
= NULL
;
1368 if (!whole
->bd_holders
)
1369 whole
->bd_holder
= NULL
;
1371 spin_unlock(&bdev_lock
);
1374 * If this was the last claim, remove holder link and
1375 * unblock evpoll if it was a write holder.
1377 if (bdev_free
&& bdev
->bd_write_holder
) {
1378 disk_unblock_events(disk
);
1379 bdev
->bd_write_holder
= false;
1384 * Trigger event checking and tell drivers to flush MEDIA_CHANGE
1385 * event. This is to ensure detection of media removal commanded
1386 * from userland - e.g. eject(1).
1388 disk_flush_events(disk
, DISK_EVENT_MEDIA_CHANGE
);
1390 if (bdev_is_partition(bdev
))
1391 blkdev_put_part(bdev
, mode
);
1393 blkdev_put_whole(bdev
, mode
);
1394 mutex_unlock(&disk
->open_mutex
);
1396 blkdev_put_no_open(bdev
);
1398 EXPORT_SYMBOL(blkdev_put
);
1400 static int blkdev_close(struct inode
* inode
, struct file
* filp
)
1402 struct block_device
*bdev
= I_BDEV(bdev_file_inode(filp
));
1403 blkdev_put(bdev
, filp
->f_mode
);
1407 static long block_ioctl(struct file
*file
, unsigned cmd
, unsigned long arg
)
1409 struct block_device
*bdev
= I_BDEV(bdev_file_inode(file
));
1410 fmode_t mode
= file
->f_mode
;
1413 * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
1414 * to updated it before every ioctl.
1416 if (file
->f_flags
& O_NDELAY
)
1417 mode
|= FMODE_NDELAY
;
1419 mode
&= ~FMODE_NDELAY
;
1421 return blkdev_ioctl(bdev
, mode
, cmd
, arg
);
1425 * Write data to the block device. Only intended for the block device itself
1426 * and the raw driver which basically is a fake block device.
1428 * Does not take i_mutex for the write and thus is not for general purpose
1431 static ssize_t
blkdev_write_iter(struct kiocb
*iocb
, struct iov_iter
*from
)
1433 struct file
*file
= iocb
->ki_filp
;
1434 struct inode
*bd_inode
= bdev_file_inode(file
);
1435 loff_t size
= i_size_read(bd_inode
);
1436 struct blk_plug plug
;
1440 if (bdev_read_only(I_BDEV(bd_inode
)))
1443 if (IS_SWAPFILE(bd_inode
) && !is_hibernate_resume_dev(bd_inode
->i_rdev
))
1446 if (!iov_iter_count(from
))
1449 if (iocb
->ki_pos
>= size
)
1452 if ((iocb
->ki_flags
& (IOCB_NOWAIT
| IOCB_DIRECT
)) == IOCB_NOWAIT
)
1455 size
-= iocb
->ki_pos
;
1456 if (iov_iter_count(from
) > size
) {
1457 shorted
= iov_iter_count(from
) - size
;
1458 iov_iter_truncate(from
, size
);
1461 blk_start_plug(&plug
);
1462 ret
= __generic_file_write_iter(iocb
, from
);
1464 ret
= generic_write_sync(iocb
, ret
);
1465 iov_iter_reexpand(from
, iov_iter_count(from
) + shorted
);
1466 blk_finish_plug(&plug
);
1470 static ssize_t
blkdev_read_iter(struct kiocb
*iocb
, struct iov_iter
*to
)
1472 struct file
*file
= iocb
->ki_filp
;
1473 struct inode
*bd_inode
= bdev_file_inode(file
);
1474 loff_t size
= i_size_read(bd_inode
);
1475 loff_t pos
= iocb
->ki_pos
;
1483 if (iov_iter_count(to
) > size
) {
1484 shorted
= iov_iter_count(to
) - size
;
1485 iov_iter_truncate(to
, size
);
1488 ret
= generic_file_read_iter(iocb
, to
);
1489 iov_iter_reexpand(to
, iov_iter_count(to
) + shorted
);
1493 static int blkdev_writepages(struct address_space
*mapping
,
1494 struct writeback_control
*wbc
)
1496 return generic_writepages(mapping
, wbc
);
1499 static const struct address_space_operations def_blk_aops
= {
1500 .set_page_dirty
= __set_page_dirty_buffers
,
1501 .readpage
= blkdev_readpage
,
1502 .readahead
= blkdev_readahead
,
1503 .writepage
= blkdev_writepage
,
1504 .write_begin
= blkdev_write_begin
,
1505 .write_end
= blkdev_write_end
,
1506 .writepages
= blkdev_writepages
,
1507 .direct_IO
= blkdev_direct_IO
,
1508 .migratepage
= buffer_migrate_page_norefs
,
1509 .is_dirty_writeback
= buffer_check_dirty_writeback
,
1512 #define BLKDEV_FALLOC_FL_SUPPORTED \
1513 (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
1514 FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE)
1516 static long blkdev_fallocate(struct file
*file
, int mode
, loff_t start
,
1519 struct block_device
*bdev
= I_BDEV(bdev_file_inode(file
));
1520 loff_t end
= start
+ len
- 1;
1524 /* Fail if we don't recognize the flags. */
1525 if (mode
& ~BLKDEV_FALLOC_FL_SUPPORTED
)
1528 /* Don't go off the end of the device. */
1529 isize
= i_size_read(bdev
->bd_inode
);
1533 if (mode
& FALLOC_FL_KEEP_SIZE
) {
1534 len
= isize
- start
;
1535 end
= start
+ len
- 1;
1541 * Don't allow IO that isn't aligned to logical block size.
1543 if ((start
| len
) & (bdev_logical_block_size(bdev
) - 1))
1546 /* Invalidate the page cache, including dirty pages. */
1547 error
= truncate_bdev_range(bdev
, file
->f_mode
, start
, end
);
1552 case FALLOC_FL_ZERO_RANGE
:
1553 case FALLOC_FL_ZERO_RANGE
| FALLOC_FL_KEEP_SIZE
:
1554 error
= blkdev_issue_zeroout(bdev
, start
>> 9, len
>> 9,
1555 GFP_KERNEL
, BLKDEV_ZERO_NOUNMAP
);
1557 case FALLOC_FL_PUNCH_HOLE
| FALLOC_FL_KEEP_SIZE
:
1558 error
= blkdev_issue_zeroout(bdev
, start
>> 9, len
>> 9,
1559 GFP_KERNEL
, BLKDEV_ZERO_NOFALLBACK
);
1561 case FALLOC_FL_PUNCH_HOLE
| FALLOC_FL_KEEP_SIZE
| FALLOC_FL_NO_HIDE_STALE
:
1562 error
= blkdev_issue_discard(bdev
, start
>> 9, len
>> 9,
1572 * Invalidate the page cache again; if someone wandered in and dirtied
1573 * a page, we just discard it - userspace has no way of knowing whether
1574 * the write happened before or after discard completing...
1576 return truncate_bdev_range(bdev
, file
->f_mode
, start
, end
);
1579 const struct file_operations def_blk_fops
= {
1580 .open
= blkdev_open
,
1581 .release
= blkdev_close
,
1582 .llseek
= block_llseek
,
1583 .read_iter
= blkdev_read_iter
,
1584 .write_iter
= blkdev_write_iter
,
1585 .iopoll
= blkdev_iopoll
,
1586 .mmap
= generic_file_mmap
,
1587 .fsync
= blkdev_fsync
,
1588 .unlocked_ioctl
= block_ioctl
,
1589 #ifdef CONFIG_COMPAT
1590 .compat_ioctl
= compat_blkdev_ioctl
,
1592 .splice_read
= generic_file_splice_read
,
1593 .splice_write
= iter_file_splice_write
,
1594 .fallocate
= blkdev_fallocate
,
1598 * lookup_bdev - lookup a struct block_device by name
1599 * @pathname: special file representing the block device
1600 * @dev: return value of the block device's dev_t
1602 * Get a reference to the blockdevice at @pathname in the current
1603 * namespace if possible and return it. Return ERR_PTR(error)
1606 int lookup_bdev(const char *pathname
, dev_t
*dev
)
1608 struct inode
*inode
;
1612 if (!pathname
|| !*pathname
)
1615 error
= kern_path(pathname
, LOOKUP_FOLLOW
, &path
);
1619 inode
= d_backing_inode(path
.dentry
);
1621 if (!S_ISBLK(inode
->i_mode
))
1624 if (!may_open_dev(&path
))
1627 *dev
= inode
->i_rdev
;
1633 EXPORT_SYMBOL(lookup_bdev
);
1635 int __invalidate_device(struct block_device
*bdev
, bool kill_dirty
)
1637 struct super_block
*sb
= get_super(bdev
);
1642 * no need to lock the super, get_super holds the
1643 * read mutex so the filesystem cannot go away
1644 * under us (->put_super runs with the write lock
1647 shrink_dcache_sb(sb
);
1648 res
= invalidate_inodes(sb
, kill_dirty
);
1651 invalidate_bdev(bdev
);
1654 EXPORT_SYMBOL(__invalidate_device
);
1656 void iterate_bdevs(void (*func
)(struct block_device
*, void *), void *arg
)
1658 struct inode
*inode
, *old_inode
= NULL
;
1660 spin_lock(&blockdev_superblock
->s_inode_list_lock
);
1661 list_for_each_entry(inode
, &blockdev_superblock
->s_inodes
, i_sb_list
) {
1662 struct address_space
*mapping
= inode
->i_mapping
;
1663 struct block_device
*bdev
;
1665 spin_lock(&inode
->i_lock
);
1666 if (inode
->i_state
& (I_FREEING
|I_WILL_FREE
|I_NEW
) ||
1667 mapping
->nrpages
== 0) {
1668 spin_unlock(&inode
->i_lock
);
1672 spin_unlock(&inode
->i_lock
);
1673 spin_unlock(&blockdev_superblock
->s_inode_list_lock
);
1675 * We hold a reference to 'inode' so it couldn't have been
1676 * removed from s_inodes list while we dropped the
1677 * s_inode_list_lock We cannot iput the inode now as we can
1678 * be holding the last reference and we cannot iput it under
1679 * s_inode_list_lock. So we keep the reference and iput it
1684 bdev
= I_BDEV(inode
);
1686 mutex_lock(&bdev
->bd_disk
->open_mutex
);
1687 if (bdev
->bd_openers
)
1689 mutex_unlock(&bdev
->bd_disk
->open_mutex
);
1691 spin_lock(&blockdev_superblock
->s_inode_list_lock
);
1693 spin_unlock(&blockdev_superblock
->s_inode_list_lock
);