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8#include <linux/init.h>
9#include <linux/mm.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/dax.h>
22#include <linux/buffer_head.h>
23#include <linux/swap.h>
24#include <linux/pagevec.h>
25#include <linux/writeback.h>
26#include <linux/mpage.h>
27#include <linux/mount.h>
28#include <linux/uio.h>
29#include <linux/namei.h>
30#include <linux/log2.h>
31#include <linux/cleancache.h>
32#include <linux/dax.h>
33#include <linux/badblocks.h>
34#include <linux/task_io_accounting_ops.h>
35#include <linux/falloc.h>
36#include <linux/uaccess.h>
37#include "internal.h"
38
39struct bdev_inode {
40 struct block_device bdev;
41 struct inode vfs_inode;
42};
43
44static const struct address_space_operations def_blk_aops;
45
46static inline struct bdev_inode *BDEV_I(struct inode *inode)
47{
48 return container_of(inode, struct bdev_inode, vfs_inode);
49}
50
51struct block_device *I_BDEV(struct inode *inode)
52{
53 return &BDEV_I(inode)->bdev;
54}
55EXPORT_SYMBOL(I_BDEV);
56
57static void bdev_write_inode(struct block_device *bdev)
58{
59 struct inode *inode = bdev->bd_inode;
60 int ret;
61
62 spin_lock(&inode->i_lock);
63 while (inode->i_state & I_DIRTY) {
64 spin_unlock(&inode->i_lock);
65 ret = write_inode_now(inode, true);
66 if (ret) {
67 char name[BDEVNAME_SIZE];
68 pr_warn_ratelimited("VFS: Dirty inode writeback failed "
69 "for block device %s (err=%d).\n",
70 bdevname(bdev, name), ret);
71 }
72 spin_lock(&inode->i_lock);
73 }
74 spin_unlock(&inode->i_lock);
75}
76
77
78void kill_bdev(struct block_device *bdev)
79{
80 struct address_space *mapping = bdev->bd_inode->i_mapping;
81
82 if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
83 return;
84
85 invalidate_bh_lrus();
86 truncate_inode_pages(mapping, 0);
87}
88EXPORT_SYMBOL(kill_bdev);
89
90
91void invalidate_bdev(struct block_device *bdev)
92{
93 struct address_space *mapping = bdev->bd_inode->i_mapping;
94
95 if (mapping->nrpages) {
96 invalidate_bh_lrus();
97 lru_add_drain_all();
98 invalidate_mapping_pages(mapping, 0, -1);
99 }
100
101
102
103 cleancache_invalidate_inode(mapping);
104}
105EXPORT_SYMBOL(invalidate_bdev);
106
107int set_blocksize(struct block_device *bdev, int size)
108{
109
110 if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size))
111 return -EINVAL;
112
113
114 if (size < bdev_logical_block_size(bdev))
115 return -EINVAL;
116
117
118 if (bdev->bd_block_size != size) {
119 sync_blockdev(bdev);
120 bdev->bd_block_size = size;
121 bdev->bd_inode->i_blkbits = blksize_bits(size);
122 kill_bdev(bdev);
123 }
124 return 0;
125}
126
127EXPORT_SYMBOL(set_blocksize);
128
129int sb_set_blocksize(struct super_block *sb, int size)
130{
131 if (set_blocksize(sb->s_bdev, size))
132 return 0;
133
134
135 sb->s_blocksize = size;
136 sb->s_blocksize_bits = blksize_bits(size);
137 return sb->s_blocksize;
138}
139
140EXPORT_SYMBOL(sb_set_blocksize);
141
142int sb_min_blocksize(struct super_block *sb, int size)
143{
144 int minsize = bdev_logical_block_size(sb->s_bdev);
145 if (size < minsize)
146 size = minsize;
147 return sb_set_blocksize(sb, size);
148}
149
150EXPORT_SYMBOL(sb_min_blocksize);
151
152static int
153blkdev_get_block(struct inode *inode, sector_t iblock,
154 struct buffer_head *bh, int create)
155{
156 bh->b_bdev = I_BDEV(inode);
157 bh->b_blocknr = iblock;
158 set_buffer_mapped(bh);
159 return 0;
160}
161
162static struct inode *bdev_file_inode(struct file *file)
163{
164 return file->f_mapping->host;
165}
166
167static unsigned int dio_bio_write_op(struct kiocb *iocb)
168{
169 unsigned int op = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
170
171
172 if (iocb->ki_flags & IOCB_DSYNC)
173 op |= REQ_FUA;
174 return op;
175}
176
177#define DIO_INLINE_BIO_VECS 4
178
179static void blkdev_bio_end_io_simple(struct bio *bio)
180{
181 struct task_struct *waiter = bio->bi_private;
182
183 WRITE_ONCE(bio->bi_private, NULL);
184 wake_up_process(waiter);
185}
186
187static ssize_t
188__blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
189 int nr_pages)
190{
191 struct file *file = iocb->ki_filp;
192 struct block_device *bdev = I_BDEV(bdev_file_inode(file));
193 struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs, *bvec;
194 loff_t pos = iocb->ki_pos;
195 bool should_dirty = false;
196 struct bio bio;
197 ssize_t ret;
198 blk_qc_t qc;
199 int i;
200
201 if ((pos | iov_iter_alignment(iter)) &
202 (bdev_logical_block_size(bdev) - 1))
203 return -EINVAL;
204
205 if (nr_pages <= DIO_INLINE_BIO_VECS)
206 vecs = inline_vecs;
207 else {
208 vecs = kmalloc(nr_pages * sizeof(struct bio_vec), GFP_KERNEL);
209 if (!vecs)
210 return -ENOMEM;
211 }
212
213 bio_init(&bio, vecs, nr_pages);
214 bio_set_dev(&bio, bdev);
215 bio.bi_iter.bi_sector = pos >> 9;
216 bio.bi_write_hint = iocb->ki_hint;
217 bio.bi_private = current;
218 bio.bi_end_io = blkdev_bio_end_io_simple;
219
220 ret = bio_iov_iter_get_pages(&bio, iter);
221 if (unlikely(ret))
222 return ret;
223 ret = bio.bi_iter.bi_size;
224
225 if (iov_iter_rw(iter) == READ) {
226 bio.bi_opf = REQ_OP_READ;
227 if (iter_is_iovec(iter))
228 should_dirty = true;
229 } else {
230 bio.bi_opf = dio_bio_write_op(iocb);
231 task_io_account_write(ret);
232 }
233
234 qc = submit_bio(&bio);
235 for (;;) {
236 set_current_state(TASK_UNINTERRUPTIBLE);
237 if (!READ_ONCE(bio.bi_private))
238 break;
239 if (!(iocb->ki_flags & IOCB_HIPRI) ||
240 !blk_poll(bdev_get_queue(bdev), qc))
241 io_schedule();
242 }
243 __set_current_state(TASK_RUNNING);
244
245 bio_for_each_segment_all(bvec, &bio, i) {
246 if (should_dirty && !PageCompound(bvec->bv_page))
247 set_page_dirty_lock(bvec->bv_page);
248 put_page(bvec->bv_page);
249 }
250
251 if (vecs != inline_vecs)
252 kfree(vecs);
253
254 if (unlikely(bio.bi_status))
255 ret = blk_status_to_errno(bio.bi_status);
256
257 bio_uninit(&bio);
258
259 return ret;
260}
261
262struct blkdev_dio {
263 union {
264 struct kiocb *iocb;
265 struct task_struct *waiter;
266 };
267 size_t size;
268 atomic_t ref;
269 bool multi_bio : 1;
270 bool should_dirty : 1;
271 bool is_sync : 1;
272 struct bio bio;
273};
274
275static struct bio_set *blkdev_dio_pool __read_mostly;
276
277static void blkdev_bio_end_io(struct bio *bio)
278{
279 struct blkdev_dio *dio = bio->bi_private;
280 bool should_dirty = dio->should_dirty;
281
282 if (dio->multi_bio && !atomic_dec_and_test(&dio->ref)) {
283 if (bio->bi_status && !dio->bio.bi_status)
284 dio->bio.bi_status = bio->bi_status;
285 } else {
286 if (!dio->is_sync) {
287 struct kiocb *iocb = dio->iocb;
288 ssize_t ret;
289
290 if (likely(!dio->bio.bi_status)) {
291 ret = dio->size;
292 iocb->ki_pos += ret;
293 } else {
294 ret = blk_status_to_errno(dio->bio.bi_status);
295 }
296
297 dio->iocb->ki_complete(iocb, ret, 0);
298 bio_put(&dio->bio);
299 } else {
300 struct task_struct *waiter = dio->waiter;
301
302 WRITE_ONCE(dio->waiter, NULL);
303 wake_up_process(waiter);
304 }
305 }
306
307 if (should_dirty) {
308 bio_check_pages_dirty(bio);
309 } else {
310 struct bio_vec *bvec;
311 int i;
312
313 bio_for_each_segment_all(bvec, bio, i)
314 put_page(bvec->bv_page);
315 bio_put(bio);
316 }
317}
318
319static ssize_t
320__blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
321{
322 struct file *file = iocb->ki_filp;
323 struct inode *inode = bdev_file_inode(file);
324 struct block_device *bdev = I_BDEV(inode);
325 struct blk_plug plug;
326 struct blkdev_dio *dio;
327 struct bio *bio;
328 bool is_read = (iov_iter_rw(iter) == READ), is_sync;
329 loff_t pos = iocb->ki_pos;
330 blk_qc_t qc = BLK_QC_T_NONE;
331 int ret = 0;
332
333 if ((pos | iov_iter_alignment(iter)) &
334 (bdev_logical_block_size(bdev) - 1))
335 return -EINVAL;
336
337 bio = bio_alloc_bioset(GFP_KERNEL, nr_pages, blkdev_dio_pool);
338 bio_get(bio);
339
340 dio = container_of(bio, struct blkdev_dio, bio);
341 dio->is_sync = is_sync = is_sync_kiocb(iocb);
342 if (dio->is_sync)
343 dio->waiter = current;
344 else
345 dio->iocb = iocb;
346
347 dio->size = 0;
348 dio->multi_bio = false;
349 dio->should_dirty = is_read && (iter->type == ITER_IOVEC);
350
351 blk_start_plug(&plug);
352 for (;;) {
353 bio_set_dev(bio, bdev);
354 bio->bi_iter.bi_sector = pos >> 9;
355 bio->bi_write_hint = iocb->ki_hint;
356 bio->bi_private = dio;
357 bio->bi_end_io = blkdev_bio_end_io;
358
359 ret = bio_iov_iter_get_pages(bio, iter);
360 if (unlikely(ret)) {
361 bio->bi_status = BLK_STS_IOERR;
362 bio_endio(bio);
363 break;
364 }
365
366 if (is_read) {
367 bio->bi_opf = REQ_OP_READ;
368 if (dio->should_dirty)
369 bio_set_pages_dirty(bio);
370 } else {
371 bio->bi_opf = dio_bio_write_op(iocb);
372 task_io_account_write(bio->bi_iter.bi_size);
373 }
374
375 dio->size += bio->bi_iter.bi_size;
376 pos += bio->bi_iter.bi_size;
377
378 nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES);
379 if (!nr_pages) {
380 qc = submit_bio(bio);
381 break;
382 }
383
384 if (!dio->multi_bio) {
385 dio->multi_bio = true;
386 atomic_set(&dio->ref, 2);
387 } else {
388 atomic_inc(&dio->ref);
389 }
390
391 submit_bio(bio);
392 bio = bio_alloc(GFP_KERNEL, nr_pages);
393 }
394 blk_finish_plug(&plug);
395
396 if (!is_sync)
397 return -EIOCBQUEUED;
398
399 for (;;) {
400 set_current_state(TASK_UNINTERRUPTIBLE);
401 if (!READ_ONCE(dio->waiter))
402 break;
403
404 if (!(iocb->ki_flags & IOCB_HIPRI) ||
405 !blk_poll(bdev_get_queue(bdev), qc))
406 io_schedule();
407 }
408 __set_current_state(TASK_RUNNING);
409
410 if (!ret)
411 ret = blk_status_to_errno(dio->bio.bi_status);
412 if (likely(!ret))
413 ret = dio->size;
414
415 bio_put(&dio->bio);
416 return ret;
417}
418
419static ssize_t
420blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
421{
422 int nr_pages;
423
424 nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES + 1);
425 if (!nr_pages)
426 return 0;
427 if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_PAGES)
428 return __blkdev_direct_IO_simple(iocb, iter, nr_pages);
429
430 return __blkdev_direct_IO(iocb, iter, min(nr_pages, BIO_MAX_PAGES));
431}
432
433static __init int blkdev_init(void)
434{
435 blkdev_dio_pool = bioset_create(4, offsetof(struct blkdev_dio, bio), BIOSET_NEED_BVECS);
436 if (!blkdev_dio_pool)
437 return -ENOMEM;
438 return 0;
439}
440module_init(blkdev_init);
441
442int __sync_blockdev(struct block_device *bdev, int wait)
443{
444 if (!bdev)
445 return 0;
446 if (!wait)
447 return filemap_flush(bdev->bd_inode->i_mapping);
448 return filemap_write_and_wait(bdev->bd_inode->i_mapping);
449}
450
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454
455int sync_blockdev(struct block_device *bdev)
456{
457 return __sync_blockdev(bdev, 1);
458}
459EXPORT_SYMBOL(sync_blockdev);
460
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464
465
466int fsync_bdev(struct block_device *bdev)
467{
468 struct super_block *sb = get_super(bdev);
469 if (sb) {
470 int res = sync_filesystem(sb);
471 drop_super(sb);
472 return res;
473 }
474 return sync_blockdev(bdev);
475}
476EXPORT_SYMBOL(fsync_bdev);
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489
490struct super_block *freeze_bdev(struct block_device *bdev)
491{
492 struct super_block *sb;
493 int error = 0;
494
495 mutex_lock(&bdev->bd_fsfreeze_mutex);
496 if (++bdev->bd_fsfreeze_count > 1) {
497
498
499
500
501
502 sb = get_super(bdev);
503 if (sb)
504 drop_super(sb);
505 mutex_unlock(&bdev->bd_fsfreeze_mutex);
506 return sb;
507 }
508
509 sb = get_active_super(bdev);
510 if (!sb)
511 goto out;
512 if (sb->s_op->freeze_super)
513 error = sb->s_op->freeze_super(sb);
514 else
515 error = freeze_super(sb);
516 if (error) {
517 deactivate_super(sb);
518 bdev->bd_fsfreeze_count--;
519 mutex_unlock(&bdev->bd_fsfreeze_mutex);
520 return ERR_PTR(error);
521 }
522 deactivate_super(sb);
523 out:
524 sync_blockdev(bdev);
525 mutex_unlock(&bdev->bd_fsfreeze_mutex);
526 return sb;
527}
528EXPORT_SYMBOL(freeze_bdev);
529
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535
536
537int thaw_bdev(struct block_device *bdev, struct super_block *sb)
538{
539 int error = -EINVAL;
540
541 mutex_lock(&bdev->bd_fsfreeze_mutex);
542 if (!bdev->bd_fsfreeze_count)
543 goto out;
544
545 error = 0;
546 if (--bdev->bd_fsfreeze_count > 0)
547 goto out;
548
549 if (!sb)
550 goto out;
551
552 if (sb->s_op->thaw_super)
553 error = sb->s_op->thaw_super(sb);
554 else
555 error = thaw_super(sb);
556 if (error)
557 bdev->bd_fsfreeze_count++;
558out:
559 mutex_unlock(&bdev->bd_fsfreeze_mutex);
560 return error;
561}
562EXPORT_SYMBOL(thaw_bdev);
563
564static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
565{
566 return block_write_full_page(page, blkdev_get_block, wbc);
567}
568
569static int blkdev_readpage(struct file * file, struct page * page)
570{
571 return block_read_full_page(page, blkdev_get_block);
572}
573
574static int blkdev_readpages(struct file *file, struct address_space *mapping,
575 struct list_head *pages, unsigned nr_pages)
576{
577 return mpage_readpages(mapping, pages, nr_pages, blkdev_get_block);
578}
579
580static int blkdev_write_begin(struct file *file, struct address_space *mapping,
581 loff_t pos, unsigned len, unsigned flags,
582 struct page **pagep, void **fsdata)
583{
584 return block_write_begin(mapping, pos, len, flags, pagep,
585 blkdev_get_block);
586}
587
588static int blkdev_write_end(struct file *file, struct address_space *mapping,
589 loff_t pos, unsigned len, unsigned copied,
590 struct page *page, void *fsdata)
591{
592 int ret;
593 ret = block_write_end(file, mapping, pos, len, copied, page, fsdata);
594
595 unlock_page(page);
596 put_page(page);
597
598 return ret;
599}
600
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604
605
606static loff_t block_llseek(struct file *file, loff_t offset, int whence)
607{
608 struct inode *bd_inode = bdev_file_inode(file);
609 loff_t retval;
610
611 inode_lock(bd_inode);
612 retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode));
613 inode_unlock(bd_inode);
614 return retval;
615}
616
617int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
618{
619 struct inode *bd_inode = bdev_file_inode(filp);
620 struct block_device *bdev = I_BDEV(bd_inode);
621 int error;
622
623 error = file_write_and_wait_range(filp, start, end);
624 if (error)
625 return error;
626
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630
631
632 error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL);
633 if (error == -EOPNOTSUPP)
634 error = 0;
635
636 return error;
637}
638EXPORT_SYMBOL(blkdev_fsync);
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655
656int bdev_read_page(struct block_device *bdev, sector_t sector,
657 struct page *page)
658{
659 const struct block_device_operations *ops = bdev->bd_disk->fops;
660 int result = -EOPNOTSUPP;
661
662 if (!ops->rw_page || bdev_get_integrity(bdev))
663 return result;
664
665 result = blk_queue_enter(bdev->bd_queue, 0);
666 if (result)
667 return result;
668 result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, false);
669 blk_queue_exit(bdev->bd_queue);
670 return result;
671}
672EXPORT_SYMBOL_GPL(bdev_read_page);
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692
693int bdev_write_page(struct block_device *bdev, sector_t sector,
694 struct page *page, struct writeback_control *wbc)
695{
696 int result;
697 const struct block_device_operations *ops = bdev->bd_disk->fops;
698
699 if (!ops->rw_page || bdev_get_integrity(bdev))
700 return -EOPNOTSUPP;
701 result = blk_queue_enter(bdev->bd_queue, 0);
702 if (result)
703 return result;
704
705 set_page_writeback(page);
706 result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, true);
707 if (result) {
708 end_page_writeback(page);
709 } else {
710 clean_page_buffers(page);
711 unlock_page(page);
712 }
713 blk_queue_exit(bdev->bd_queue);
714 return result;
715}
716EXPORT_SYMBOL_GPL(bdev_write_page);
717
718
719
720
721
722static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock);
723static struct kmem_cache * bdev_cachep __read_mostly;
724
725static struct inode *bdev_alloc_inode(struct super_block *sb)
726{
727 struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL);
728 if (!ei)
729 return NULL;
730 return &ei->vfs_inode;
731}
732
733static void bdev_i_callback(struct rcu_head *head)
734{
735 struct inode *inode = container_of(head, struct inode, i_rcu);
736 struct bdev_inode *bdi = BDEV_I(inode);
737
738 kmem_cache_free(bdev_cachep, bdi);
739}
740
741static void bdev_destroy_inode(struct inode *inode)
742{
743 call_rcu(&inode->i_rcu, bdev_i_callback);
744}
745
746static void init_once(void *foo)
747{
748 struct bdev_inode *ei = (struct bdev_inode *) foo;
749 struct block_device *bdev = &ei->bdev;
750
751 memset(bdev, 0, sizeof(*bdev));
752 mutex_init(&bdev->bd_mutex);
753 INIT_LIST_HEAD(&bdev->bd_list);
754#ifdef CONFIG_SYSFS
755 INIT_LIST_HEAD(&bdev->bd_holder_disks);
756#endif
757 bdev->bd_bdi = &noop_backing_dev_info;
758 inode_init_once(&ei->vfs_inode);
759
760 mutex_init(&bdev->bd_fsfreeze_mutex);
761}
762
763static void bdev_evict_inode(struct inode *inode)
764{
765 struct block_device *bdev = &BDEV_I(inode)->bdev;
766 truncate_inode_pages_final(&inode->i_data);
767 invalidate_inode_buffers(inode);
768 clear_inode(inode);
769 spin_lock(&bdev_lock);
770 list_del_init(&bdev->bd_list);
771 spin_unlock(&bdev_lock);
772
773 inode_detach_wb(inode);
774 if (bdev->bd_bdi != &noop_backing_dev_info) {
775 bdi_put(bdev->bd_bdi);
776 bdev->bd_bdi = &noop_backing_dev_info;
777 }
778}
779
780static const struct super_operations bdev_sops = {
781 .statfs = simple_statfs,
782 .alloc_inode = bdev_alloc_inode,
783 .destroy_inode = bdev_destroy_inode,
784 .drop_inode = generic_delete_inode,
785 .evict_inode = bdev_evict_inode,
786};
787
788static struct dentry *bd_mount(struct file_system_type *fs_type,
789 int flags, const char *dev_name, void *data)
790{
791 struct dentry *dent;
792 dent = mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, BDEVFS_MAGIC);
793 if (!IS_ERR(dent))
794 dent->d_sb->s_iflags |= SB_I_CGROUPWB;
795 return dent;
796}
797
798static struct file_system_type bd_type = {
799 .name = "bdev",
800 .mount = bd_mount,
801 .kill_sb = kill_anon_super,
802};
803
804struct super_block *blockdev_superblock __read_mostly;
805EXPORT_SYMBOL_GPL(blockdev_superblock);
806
807void __init bdev_cache_init(void)
808{
809 int err;
810 static struct vfsmount *bd_mnt;
811
812 bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode),
813 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
814 SLAB_MEM_SPREAD|SLAB_ACCOUNT|SLAB_PANIC),
815 init_once);
816 err = register_filesystem(&bd_type);
817 if (err)
818 panic("Cannot register bdev pseudo-fs");
819 bd_mnt = kern_mount(&bd_type);
820 if (IS_ERR(bd_mnt))
821 panic("Cannot create bdev pseudo-fs");
822 blockdev_superblock = bd_mnt->mnt_sb;
823}
824
825
826
827
828
829
830static inline unsigned long hash(dev_t dev)
831{
832 return MAJOR(dev)+MINOR(dev);
833}
834
835static int bdev_test(struct inode *inode, void *data)
836{
837 return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data;
838}
839
840static int bdev_set(struct inode *inode, void *data)
841{
842 BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data;
843 return 0;
844}
845
846static LIST_HEAD(all_bdevs);
847
848
849
850
851
852void bdev_unhash_inode(dev_t dev)
853{
854 struct inode *inode;
855
856 inode = ilookup5(blockdev_superblock, hash(dev), bdev_test, &dev);
857 if (inode) {
858 remove_inode_hash(inode);
859 iput(inode);
860 }
861}
862
863struct block_device *bdget(dev_t dev)
864{
865 struct block_device *bdev;
866 struct inode *inode;
867
868 inode = iget5_locked(blockdev_superblock, hash(dev),
869 bdev_test, bdev_set, &dev);
870
871 if (!inode)
872 return NULL;
873
874 bdev = &BDEV_I(inode)->bdev;
875
876 if (inode->i_state & I_NEW) {
877 bdev->bd_contains = NULL;
878 bdev->bd_super = NULL;
879 bdev->bd_inode = inode;
880 bdev->bd_block_size = i_blocksize(inode);
881 bdev->bd_part_count = 0;
882 bdev->bd_invalidated = 0;
883 inode->i_mode = S_IFBLK;
884 inode->i_rdev = dev;
885 inode->i_bdev = bdev;
886 inode->i_data.a_ops = &def_blk_aops;
887 mapping_set_gfp_mask(&inode->i_data, GFP_USER);
888 spin_lock(&bdev_lock);
889 list_add(&bdev->bd_list, &all_bdevs);
890 spin_unlock(&bdev_lock);
891 unlock_new_inode(inode);
892 }
893 return bdev;
894}
895
896EXPORT_SYMBOL(bdget);
897
898
899
900
901
902struct block_device *bdgrab(struct block_device *bdev)
903{
904 ihold(bdev->bd_inode);
905 return bdev;
906}
907EXPORT_SYMBOL(bdgrab);
908
909long nr_blockdev_pages(void)
910{
911 struct block_device *bdev;
912 long ret = 0;
913 spin_lock(&bdev_lock);
914 list_for_each_entry(bdev, &all_bdevs, bd_list) {
915 ret += bdev->bd_inode->i_mapping->nrpages;
916 }
917 spin_unlock(&bdev_lock);
918 return ret;
919}
920
921void bdput(struct block_device *bdev)
922{
923 iput(bdev->bd_inode);
924}
925
926EXPORT_SYMBOL(bdput);
927
928static struct block_device *bd_acquire(struct inode *inode)
929{
930 struct block_device *bdev;
931
932 spin_lock(&bdev_lock);
933 bdev = inode->i_bdev;
934 if (bdev && !inode_unhashed(bdev->bd_inode)) {
935 bdgrab(bdev);
936 spin_unlock(&bdev_lock);
937 return bdev;
938 }
939 spin_unlock(&bdev_lock);
940
941
942
943
944
945
946
947 if (bdev)
948 bd_forget(inode);
949
950 bdev = bdget(inode->i_rdev);
951 if (bdev) {
952 spin_lock(&bdev_lock);
953 if (!inode->i_bdev) {
954
955
956
957
958
959
960 bdgrab(bdev);
961 inode->i_bdev = bdev;
962 inode->i_mapping = bdev->bd_inode->i_mapping;
963 }
964 spin_unlock(&bdev_lock);
965 }
966 return bdev;
967}
968
969
970
971void bd_forget(struct inode *inode)
972{
973 struct block_device *bdev = NULL;
974
975 spin_lock(&bdev_lock);
976 if (!sb_is_blkdev_sb(inode->i_sb))
977 bdev = inode->i_bdev;
978 inode->i_bdev = NULL;
979 inode->i_mapping = &inode->i_data;
980 spin_unlock(&bdev_lock);
981
982 if (bdev)
983 bdput(bdev);
984}
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000static bool bd_may_claim(struct block_device *bdev, struct block_device *whole,
1001 void *holder)
1002{
1003 if (bdev->bd_holder == holder)
1004 return true;
1005 else if (bdev->bd_holder != NULL)
1006 return false;
1007 else if (whole == bdev)
1008 return true;
1009
1010 else if (whole->bd_holder == bd_may_claim)
1011 return true;
1012 else if (whole->bd_holder != NULL)
1013 return false;
1014 else
1015 return true;
1016}
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036static int bd_prepare_to_claim(struct block_device *bdev,
1037 struct block_device *whole, void *holder)
1038{
1039retry:
1040
1041 if (!bd_may_claim(bdev, whole, holder))
1042 return -EBUSY;
1043
1044
1045 if (whole->bd_claiming) {
1046 wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0);
1047 DEFINE_WAIT(wait);
1048
1049 prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
1050 spin_unlock(&bdev_lock);
1051 schedule();
1052 finish_wait(wq, &wait);
1053 spin_lock(&bdev_lock);
1054 goto retry;
1055 }
1056
1057
1058 return 0;
1059}
1060
1061static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno)
1062{
1063 struct gendisk *disk = get_gendisk(bdev->bd_dev, partno);
1064
1065 if (!disk)
1066 return NULL;
1067
1068
1069
1070
1071
1072
1073
1074
1075 if (inode_unhashed(bdev->bd_inode)) {
1076 put_disk_and_module(disk);
1077 return NULL;
1078 }
1079 return disk;
1080}
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105static struct block_device *bd_start_claiming(struct block_device *bdev,
1106 void *holder)
1107{
1108 struct gendisk *disk;
1109 struct block_device *whole;
1110 int partno, err;
1111
1112 might_sleep();
1113
1114
1115
1116
1117
1118 disk = bdev_get_gendisk(bdev, &partno);
1119 if (!disk)
1120 return ERR_PTR(-ENXIO);
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130 if (partno)
1131 whole = bdget_disk(disk, 0);
1132 else
1133 whole = bdgrab(bdev);
1134
1135 put_disk_and_module(disk);
1136 if (!whole)
1137 return ERR_PTR(-ENOMEM);
1138
1139
1140 spin_lock(&bdev_lock);
1141
1142 err = bd_prepare_to_claim(bdev, whole, holder);
1143 if (err == 0) {
1144 whole->bd_claiming = holder;
1145 spin_unlock(&bdev_lock);
1146 return whole;
1147 } else {
1148 spin_unlock(&bdev_lock);
1149 bdput(whole);
1150 return ERR_PTR(err);
1151 }
1152}
1153
1154#ifdef CONFIG_SYSFS
1155struct bd_holder_disk {
1156 struct list_head list;
1157 struct gendisk *disk;
1158 int refcnt;
1159};
1160
1161static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev,
1162 struct gendisk *disk)
1163{
1164 struct bd_holder_disk *holder;
1165
1166 list_for_each_entry(holder, &bdev->bd_holder_disks, list)
1167 if (holder->disk == disk)
1168 return holder;
1169 return NULL;
1170}
1171
1172static int add_symlink(struct kobject *from, struct kobject *to)
1173{
1174 return sysfs_create_link(from, to, kobject_name(to));
1175}
1176
1177static void del_symlink(struct kobject *from, struct kobject *to)
1178{
1179 sysfs_remove_link(from, kobject_name(to));
1180}
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
1211{
1212 struct bd_holder_disk *holder;
1213 int ret = 0;
1214
1215 mutex_lock(&bdev->bd_mutex);
1216
1217 WARN_ON_ONCE(!bdev->bd_holder);
1218
1219
1220 if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir))
1221 goto out_unlock;
1222
1223 holder = bd_find_holder_disk(bdev, disk);
1224 if (holder) {
1225 holder->refcnt++;
1226 goto out_unlock;
1227 }
1228
1229 holder = kzalloc(sizeof(*holder), GFP_KERNEL);
1230 if (!holder) {
1231 ret = -ENOMEM;
1232 goto out_unlock;
1233 }
1234
1235 INIT_LIST_HEAD(&holder->list);
1236 holder->disk = disk;
1237 holder->refcnt = 1;
1238
1239 ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
1240 if (ret)
1241 goto out_free;
1242
1243 ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
1244 if (ret)
1245 goto out_del;
1246
1247
1248
1249
1250 kobject_get(bdev->bd_part->holder_dir);
1251
1252 list_add(&holder->list, &bdev->bd_holder_disks);
1253 goto out_unlock;
1254
1255out_del:
1256 del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
1257out_free:
1258 kfree(holder);
1259out_unlock:
1260 mutex_unlock(&bdev->bd_mutex);
1261 return ret;
1262}
1263EXPORT_SYMBOL_GPL(bd_link_disk_holder);
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
1276{
1277 struct bd_holder_disk *holder;
1278
1279 mutex_lock(&bdev->bd_mutex);
1280
1281 holder = bd_find_holder_disk(bdev, disk);
1282
1283 if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
1284 del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
1285 del_symlink(bdev->bd_part->holder_dir,
1286 &disk_to_dev(disk)->kobj);
1287 kobject_put(bdev->bd_part->holder_dir);
1288 list_del_init(&holder->list);
1289 kfree(holder);
1290 }
1291
1292 mutex_unlock(&bdev->bd_mutex);
1293}
1294EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
1295#endif
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307static void flush_disk(struct block_device *bdev, bool kill_dirty)
1308{
1309 if (__invalidate_device(bdev, kill_dirty)) {
1310 printk(KERN_WARNING "VFS: busy inodes on changed media or "
1311 "resized disk %s\n",
1312 bdev->bd_disk ? bdev->bd_disk->disk_name : "");
1313 }
1314
1315 if (!bdev->bd_disk)
1316 return;
1317 if (disk_part_scan_enabled(bdev->bd_disk))
1318 bdev->bd_invalidated = 1;
1319}
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330void check_disk_size_change(struct gendisk *disk, struct block_device *bdev)
1331{
1332 loff_t disk_size, bdev_size;
1333
1334 disk_size = (loff_t)get_capacity(disk) << 9;
1335 bdev_size = i_size_read(bdev->bd_inode);
1336 if (disk_size != bdev_size) {
1337 printk(KERN_INFO
1338 "%s: detected capacity change from %lld to %lld\n",
1339 disk->disk_name, bdev_size, disk_size);
1340 i_size_write(bdev->bd_inode, disk_size);
1341 if (bdev_size > disk_size)
1342 flush_disk(bdev, false);
1343 }
1344}
1345EXPORT_SYMBOL(check_disk_size_change);
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355int revalidate_disk(struct gendisk *disk)
1356{
1357 struct block_device *bdev;
1358 int ret = 0;
1359
1360 if (disk->fops->revalidate_disk)
1361 ret = disk->fops->revalidate_disk(disk);
1362 bdev = bdget_disk(disk, 0);
1363 if (!bdev)
1364 return ret;
1365
1366 mutex_lock(&bdev->bd_mutex);
1367 check_disk_size_change(disk, bdev);
1368 bdev->bd_invalidated = 0;
1369 mutex_unlock(&bdev->bd_mutex);
1370 bdput(bdev);
1371 return ret;
1372}
1373EXPORT_SYMBOL(revalidate_disk);
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384int check_disk_change(struct block_device *bdev)
1385{
1386 struct gendisk *disk = bdev->bd_disk;
1387 const struct block_device_operations *bdops = disk->fops;
1388 unsigned int events;
1389
1390 events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE |
1391 DISK_EVENT_EJECT_REQUEST);
1392 if (!(events & DISK_EVENT_MEDIA_CHANGE))
1393 return 0;
1394
1395 flush_disk(bdev, true);
1396 if (bdops->revalidate_disk)
1397 bdops->revalidate_disk(bdev->bd_disk);
1398 return 1;
1399}
1400
1401EXPORT_SYMBOL(check_disk_change);
1402
1403void bd_set_size(struct block_device *bdev, loff_t size)
1404{
1405 unsigned bsize = bdev_logical_block_size(bdev);
1406
1407 inode_lock(bdev->bd_inode);
1408 i_size_write(bdev->bd_inode, size);
1409 inode_unlock(bdev->bd_inode);
1410 while (bsize < PAGE_SIZE) {
1411 if (size & bsize)
1412 break;
1413 bsize <<= 1;
1414 }
1415 bdev->bd_block_size = bsize;
1416 bdev->bd_inode->i_blkbits = blksize_bits(bsize);
1417}
1418EXPORT_SYMBOL(bd_set_size);
1419
1420static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
1421
1422
1423
1424
1425
1426
1427
1428
1429static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
1430{
1431 struct gendisk *disk;
1432 int ret;
1433 int partno;
1434 int perm = 0;
1435 bool first_open = false;
1436
1437 if (mode & FMODE_READ)
1438 perm |= MAY_READ;
1439 if (mode & FMODE_WRITE)
1440 perm |= MAY_WRITE;
1441
1442
1443
1444 if (!for_part) {
1445 ret = devcgroup_inode_permission(bdev->bd_inode, perm);
1446 if (ret != 0) {
1447 bdput(bdev);
1448 return ret;
1449 }
1450 }
1451
1452 restart:
1453
1454 ret = -ENXIO;
1455 disk = bdev_get_gendisk(bdev, &partno);
1456 if (!disk)
1457 goto out;
1458
1459 disk_block_events(disk);
1460 mutex_lock_nested(&bdev->bd_mutex, for_part);
1461 if (!bdev->bd_openers) {
1462 first_open = true;
1463 bdev->bd_disk = disk;
1464 bdev->bd_queue = disk->queue;
1465 bdev->bd_contains = bdev;
1466 bdev->bd_partno = partno;
1467
1468 if (!partno) {
1469 ret = -ENXIO;
1470 bdev->bd_part = disk_get_part(disk, partno);
1471 if (!bdev->bd_part)
1472 goto out_clear;
1473
1474 ret = 0;
1475 if (disk->fops->open) {
1476 ret = disk->fops->open(bdev, mode);
1477 if (ret == -ERESTARTSYS) {
1478
1479
1480
1481
1482 disk_put_part(bdev->bd_part);
1483 bdev->bd_part = NULL;
1484 bdev->bd_disk = NULL;
1485 bdev->bd_queue = NULL;
1486 mutex_unlock(&bdev->bd_mutex);
1487 disk_unblock_events(disk);
1488 put_disk_and_module(disk);
1489 goto restart;
1490 }
1491 }
1492
1493 if (!ret)
1494 bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
1495
1496
1497
1498
1499
1500
1501
1502 if (bdev->bd_invalidated) {
1503 if (!ret)
1504 rescan_partitions(disk, bdev);
1505 else if (ret == -ENOMEDIUM)
1506 invalidate_partitions(disk, bdev);
1507 }
1508
1509 if (ret)
1510 goto out_clear;
1511 } else {
1512 struct block_device *whole;
1513 whole = bdget_disk(disk, 0);
1514 ret = -ENOMEM;
1515 if (!whole)
1516 goto out_clear;
1517 BUG_ON(for_part);
1518 ret = __blkdev_get(whole, mode, 1);
1519 if (ret)
1520 goto out_clear;
1521 bdev->bd_contains = whole;
1522 bdev->bd_part = disk_get_part(disk, partno);
1523 if (!(disk->flags & GENHD_FL_UP) ||
1524 !bdev->bd_part || !bdev->bd_part->nr_sects) {
1525 ret = -ENXIO;
1526 goto out_clear;
1527 }
1528 bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
1529 }
1530
1531 if (bdev->bd_bdi == &noop_backing_dev_info)
1532 bdev->bd_bdi = bdi_get(disk->queue->backing_dev_info);
1533 } else {
1534 if (bdev->bd_contains == bdev) {
1535 ret = 0;
1536 if (bdev->bd_disk->fops->open)
1537 ret = bdev->bd_disk->fops->open(bdev, mode);
1538
1539 if (bdev->bd_invalidated) {
1540 if (!ret)
1541 rescan_partitions(bdev->bd_disk, bdev);
1542 else if (ret == -ENOMEDIUM)
1543 invalidate_partitions(bdev->bd_disk, bdev);
1544 }
1545 if (ret)
1546 goto out_unlock_bdev;
1547 }
1548 }
1549 bdev->bd_openers++;
1550 if (for_part)
1551 bdev->bd_part_count++;
1552 mutex_unlock(&bdev->bd_mutex);
1553 disk_unblock_events(disk);
1554
1555 if (!first_open)
1556 put_disk_and_module(disk);
1557 return 0;
1558
1559 out_clear:
1560 disk_put_part(bdev->bd_part);
1561 bdev->bd_disk = NULL;
1562 bdev->bd_part = NULL;
1563 bdev->bd_queue = NULL;
1564 if (bdev != bdev->bd_contains)
1565 __blkdev_put(bdev->bd_contains, mode, 1);
1566 bdev->bd_contains = NULL;
1567 out_unlock_bdev:
1568 mutex_unlock(&bdev->bd_mutex);
1569 disk_unblock_events(disk);
1570 put_disk_and_module(disk);
1571 out:
1572 bdput(bdev);
1573
1574 return ret;
1575}
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
1597{
1598 struct block_device *whole = NULL;
1599 int res;
1600
1601 WARN_ON_ONCE((mode & FMODE_EXCL) && !holder);
1602
1603 if ((mode & FMODE_EXCL) && holder) {
1604 whole = bd_start_claiming(bdev, holder);
1605 if (IS_ERR(whole)) {
1606 bdput(bdev);
1607 return PTR_ERR(whole);
1608 }
1609 }
1610
1611 res = __blkdev_get(bdev, mode, 0);
1612
1613 if (whole) {
1614 struct gendisk *disk = whole->bd_disk;
1615
1616
1617 mutex_lock(&bdev->bd_mutex);
1618 spin_lock(&bdev_lock);
1619
1620 if (!res) {
1621 BUG_ON(!bd_may_claim(bdev, whole, holder));
1622
1623
1624
1625
1626
1627
1628 whole->bd_holders++;
1629 whole->bd_holder = bd_may_claim;
1630 bdev->bd_holders++;
1631 bdev->bd_holder = holder;
1632 }
1633
1634
1635 BUG_ON(whole->bd_claiming != holder);
1636 whole->bd_claiming = NULL;
1637 wake_up_bit(&whole->bd_claiming, 0);
1638
1639 spin_unlock(&bdev_lock);
1640
1641
1642
1643
1644
1645
1646
1647
1648 if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder &&
1649 (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
1650 bdev->bd_write_holder = true;
1651 disk_block_events(disk);
1652 }
1653
1654 mutex_unlock(&bdev->bd_mutex);
1655 bdput(whole);
1656 }
1657
1658 return res;
1659}
1660EXPORT_SYMBOL(blkdev_get);
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
1680 void *holder)
1681{
1682 struct block_device *bdev;
1683 int err;
1684
1685 bdev = lookup_bdev(path);
1686 if (IS_ERR(bdev))
1687 return bdev;
1688
1689 err = blkdev_get(bdev, mode, holder);
1690 if (err)
1691 return ERR_PTR(err);
1692
1693 if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) {
1694 blkdev_put(bdev, mode);
1695 return ERR_PTR(-EACCES);
1696 }
1697
1698 return bdev;
1699}
1700EXPORT_SYMBOL(blkdev_get_by_path);
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
1725{
1726 struct block_device *bdev;
1727 int err;
1728
1729 bdev = bdget(dev);
1730 if (!bdev)
1731 return ERR_PTR(-ENOMEM);
1732
1733 err = blkdev_get(bdev, mode, holder);
1734 if (err)
1735 return ERR_PTR(err);
1736
1737 return bdev;
1738}
1739EXPORT_SYMBOL(blkdev_get_by_dev);
1740
1741static int blkdev_open(struct inode * inode, struct file * filp)
1742{
1743 struct block_device *bdev;
1744
1745
1746
1747
1748
1749
1750
1751 filp->f_flags |= O_LARGEFILE;
1752
1753 filp->f_mode |= FMODE_NOWAIT;
1754
1755 if (filp->f_flags & O_NDELAY)
1756 filp->f_mode |= FMODE_NDELAY;
1757 if (filp->f_flags & O_EXCL)
1758 filp->f_mode |= FMODE_EXCL;
1759 if ((filp->f_flags & O_ACCMODE) == 3)
1760 filp->f_mode |= FMODE_WRITE_IOCTL;
1761
1762 bdev = bd_acquire(inode);
1763 if (bdev == NULL)
1764 return -ENOMEM;
1765
1766 filp->f_mapping = bdev->bd_inode->i_mapping;
1767 filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping);
1768
1769 return blkdev_get(bdev, filp->f_mode, filp);
1770}
1771
1772static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
1773{
1774 struct gendisk *disk = bdev->bd_disk;
1775 struct block_device *victim = NULL;
1776
1777 mutex_lock_nested(&bdev->bd_mutex, for_part);
1778 if (for_part)
1779 bdev->bd_part_count--;
1780
1781 if (!--bdev->bd_openers) {
1782 WARN_ON_ONCE(bdev->bd_holders);
1783 sync_blockdev(bdev);
1784 kill_bdev(bdev);
1785
1786 bdev_write_inode(bdev);
1787 }
1788 if (bdev->bd_contains == bdev) {
1789 if (disk->fops->release)
1790 disk->fops->release(disk, mode);
1791 }
1792 if (!bdev->bd_openers) {
1793 disk_put_part(bdev->bd_part);
1794 bdev->bd_part = NULL;
1795 bdev->bd_disk = NULL;
1796 if (bdev != bdev->bd_contains)
1797 victim = bdev->bd_contains;
1798 bdev->bd_contains = NULL;
1799
1800 put_disk_and_module(disk);
1801 }
1802 mutex_unlock(&bdev->bd_mutex);
1803 bdput(bdev);
1804 if (victim)
1805 __blkdev_put(victim, mode, 1);
1806}
1807
1808void blkdev_put(struct block_device *bdev, fmode_t mode)
1809{
1810 mutex_lock(&bdev->bd_mutex);
1811
1812 if (mode & FMODE_EXCL) {
1813 bool bdev_free;
1814
1815
1816
1817
1818
1819
1820 spin_lock(&bdev_lock);
1821
1822 WARN_ON_ONCE(--bdev->bd_holders < 0);
1823 WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0);
1824
1825
1826 if ((bdev_free = !bdev->bd_holders))
1827 bdev->bd_holder = NULL;
1828 if (!bdev->bd_contains->bd_holders)
1829 bdev->bd_contains->bd_holder = NULL;
1830
1831 spin_unlock(&bdev_lock);
1832
1833
1834
1835
1836
1837 if (bdev_free && bdev->bd_write_holder) {
1838 disk_unblock_events(bdev->bd_disk);
1839 bdev->bd_write_holder = false;
1840 }
1841 }
1842
1843
1844
1845
1846
1847
1848 disk_flush_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE);
1849
1850 mutex_unlock(&bdev->bd_mutex);
1851
1852 __blkdev_put(bdev, mode, 0);
1853}
1854EXPORT_SYMBOL(blkdev_put);
1855
1856static int blkdev_close(struct inode * inode, struct file * filp)
1857{
1858 struct block_device *bdev = I_BDEV(bdev_file_inode(filp));
1859 blkdev_put(bdev, filp->f_mode);
1860 return 0;
1861}
1862
1863static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
1864{
1865 struct block_device *bdev = I_BDEV(bdev_file_inode(file));
1866 fmode_t mode = file->f_mode;
1867
1868
1869
1870
1871
1872 if (file->f_flags & O_NDELAY)
1873 mode |= FMODE_NDELAY;
1874 else
1875 mode &= ~FMODE_NDELAY;
1876
1877 return blkdev_ioctl(bdev, mode, cmd, arg);
1878}
1879
1880
1881
1882
1883
1884
1885
1886
1887ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
1888{
1889 struct file *file = iocb->ki_filp;
1890 struct inode *bd_inode = bdev_file_inode(file);
1891 loff_t size = i_size_read(bd_inode);
1892 struct blk_plug plug;
1893 ssize_t ret;
1894
1895 if (bdev_read_only(I_BDEV(bd_inode)))
1896 return -EPERM;
1897
1898 if (!iov_iter_count(from))
1899 return 0;
1900
1901 if (iocb->ki_pos >= size)
1902 return -ENOSPC;
1903
1904 if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT)
1905 return -EOPNOTSUPP;
1906
1907 iov_iter_truncate(from, size - iocb->ki_pos);
1908
1909 blk_start_plug(&plug);
1910 ret = __generic_file_write_iter(iocb, from);
1911 if (ret > 0)
1912 ret = generic_write_sync(iocb, ret);
1913 blk_finish_plug(&plug);
1914 return ret;
1915}
1916EXPORT_SYMBOL_GPL(blkdev_write_iter);
1917
1918ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
1919{
1920 struct file *file = iocb->ki_filp;
1921 struct inode *bd_inode = bdev_file_inode(file);
1922 loff_t size = i_size_read(bd_inode);
1923 loff_t pos = iocb->ki_pos;
1924
1925 if (pos >= size)
1926 return 0;
1927
1928 size -= pos;
1929 iov_iter_truncate(to, size);
1930 return generic_file_read_iter(iocb, to);
1931}
1932EXPORT_SYMBOL_GPL(blkdev_read_iter);
1933
1934
1935
1936
1937
1938static int blkdev_releasepage(struct page *page, gfp_t wait)
1939{
1940 struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super;
1941
1942 if (super && super->s_op->bdev_try_to_free_page)
1943 return super->s_op->bdev_try_to_free_page(super, page, wait);
1944
1945 return try_to_free_buffers(page);
1946}
1947
1948static int blkdev_writepages(struct address_space *mapping,
1949 struct writeback_control *wbc)
1950{
1951 return generic_writepages(mapping, wbc);
1952}
1953
1954static const struct address_space_operations def_blk_aops = {
1955 .readpage = blkdev_readpage,
1956 .readpages = blkdev_readpages,
1957 .writepage = blkdev_writepage,
1958 .write_begin = blkdev_write_begin,
1959 .write_end = blkdev_write_end,
1960 .writepages = blkdev_writepages,
1961 .releasepage = blkdev_releasepage,
1962 .direct_IO = blkdev_direct_IO,
1963 .is_dirty_writeback = buffer_check_dirty_writeback,
1964};
1965
1966#define BLKDEV_FALLOC_FL_SUPPORTED \
1967 (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
1968 FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE)
1969
1970static long blkdev_fallocate(struct file *file, int mode, loff_t start,
1971 loff_t len)
1972{
1973 struct block_device *bdev = I_BDEV(bdev_file_inode(file));
1974 struct address_space *mapping;
1975 loff_t end = start + len - 1;
1976 loff_t isize;
1977 int error;
1978
1979
1980 if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED)
1981 return -EOPNOTSUPP;
1982
1983
1984 isize = i_size_read(bdev->bd_inode);
1985 if (start >= isize)
1986 return -EINVAL;
1987 if (end >= isize) {
1988 if (mode & FALLOC_FL_KEEP_SIZE) {
1989 len = isize - start;
1990 end = start + len - 1;
1991 } else
1992 return -EINVAL;
1993 }
1994
1995
1996
1997
1998 if ((start | len) & (bdev_logical_block_size(bdev) - 1))
1999 return -EINVAL;
2000
2001
2002 mapping = bdev->bd_inode->i_mapping;
2003 truncate_inode_pages_range(mapping, start, end);
2004
2005 switch (mode) {
2006 case FALLOC_FL_ZERO_RANGE:
2007 case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE:
2008 error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
2009 GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
2010 break;
2011 case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
2012 error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
2013 GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK);
2014 break;
2015 case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE:
2016 error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
2017 GFP_KERNEL, 0);
2018 break;
2019 default:
2020 return -EOPNOTSUPP;
2021 }
2022 if (error)
2023 return error;
2024
2025
2026
2027
2028
2029
2030 return invalidate_inode_pages2_range(mapping,
2031 start >> PAGE_SHIFT,
2032 end >> PAGE_SHIFT);
2033}
2034
2035const struct file_operations def_blk_fops = {
2036 .open = blkdev_open,
2037 .release = blkdev_close,
2038 .llseek = block_llseek,
2039 .read_iter = blkdev_read_iter,
2040 .write_iter = blkdev_write_iter,
2041 .mmap = generic_file_mmap,
2042 .fsync = blkdev_fsync,
2043 .unlocked_ioctl = block_ioctl,
2044#ifdef CONFIG_COMPAT
2045 .compat_ioctl = compat_blkdev_ioctl,
2046#endif
2047 .splice_read = generic_file_splice_read,
2048 .splice_write = iter_file_splice_write,
2049 .fallocate = blkdev_fallocate,
2050};
2051
2052int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)
2053{
2054 int res;
2055 mm_segment_t old_fs = get_fs();
2056 set_fs(KERNEL_DS);
2057 res = blkdev_ioctl(bdev, 0, cmd, arg);
2058 set_fs(old_fs);
2059 return res;
2060}
2061
2062EXPORT_SYMBOL(ioctl_by_bdev);
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072struct block_device *lookup_bdev(const char *pathname)
2073{
2074 struct block_device *bdev;
2075 struct inode *inode;
2076 struct path path;
2077 int error;
2078
2079 if (!pathname || !*pathname)
2080 return ERR_PTR(-EINVAL);
2081
2082 error = kern_path(pathname, LOOKUP_FOLLOW, &path);
2083 if (error)
2084 return ERR_PTR(error);
2085
2086 inode = d_backing_inode(path.dentry);
2087 error = -ENOTBLK;
2088 if (!S_ISBLK(inode->i_mode))
2089 goto fail;
2090 error = -EACCES;
2091 if (!may_open_dev(&path))
2092 goto fail;
2093 error = -ENOMEM;
2094 bdev = bd_acquire(inode);
2095 if (!bdev)
2096 goto fail;
2097out:
2098 path_put(&path);
2099 return bdev;
2100fail:
2101 bdev = ERR_PTR(error);
2102 goto out;
2103}
2104EXPORT_SYMBOL(lookup_bdev);
2105
2106int __invalidate_device(struct block_device *bdev, bool kill_dirty)
2107{
2108 struct super_block *sb = get_super(bdev);
2109 int res = 0;
2110
2111 if (sb) {
2112
2113
2114
2115
2116
2117
2118 shrink_dcache_sb(sb);
2119 res = invalidate_inodes(sb, kill_dirty);
2120 drop_super(sb);
2121 }
2122 invalidate_bdev(bdev);
2123 return res;
2124}
2125EXPORT_SYMBOL(__invalidate_device);
2126
2127void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg)
2128{
2129 struct inode *inode, *old_inode = NULL;
2130
2131 spin_lock(&blockdev_superblock->s_inode_list_lock);
2132 list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) {
2133 struct address_space *mapping = inode->i_mapping;
2134 struct block_device *bdev;
2135
2136 spin_lock(&inode->i_lock);
2137 if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) ||
2138 mapping->nrpages == 0) {
2139 spin_unlock(&inode->i_lock);
2140 continue;
2141 }
2142 __iget(inode);
2143 spin_unlock(&inode->i_lock);
2144 spin_unlock(&blockdev_superblock->s_inode_list_lock);
2145
2146
2147
2148
2149
2150
2151
2152
2153 iput(old_inode);
2154 old_inode = inode;
2155 bdev = I_BDEV(inode);
2156
2157 mutex_lock(&bdev->bd_mutex);
2158 if (bdev->bd_openers)
2159 func(bdev, arg);
2160 mutex_unlock(&bdev->bd_mutex);
2161
2162 spin_lock(&blockdev_superblock->s_inode_list_lock);
2163 }
2164 spin_unlock(&blockdev_superblock->s_inode_list_lock);
2165 iput(old_inode);
2166}
2167