4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
8 #include <linux/init.h>
10 #include <linux/fcntl.h>
11 #include <linux/slab.h>
12 #include <linux/kmod.h>
13 #include <linux/major.h>
14 #include <linux/smp_lock.h>
15 #include <linux/highmem.h>
16 #include <linux/blkdev.h>
17 #include <linux/module.h>
18 #include <linux/blkpg.h>
19 #include <linux/buffer_head.h>
20 #include <linux/writeback.h>
21 #include <linux/mpage.h>
22 #include <linux/mount.h>
23 #include <linux/uio.h>
24 #include <linux/namei.h>
25 #include <asm/uaccess.h>
29 struct block_device bdev;
30 struct inode vfs_inode;
33 static inline struct bdev_inode *BDEV_I(struct inode *inode)
35 return container_of(inode, struct bdev_inode, vfs_inode);
38 inline struct block_device *I_BDEV(struct inode *inode)
40 return &BDEV_I(inode)->bdev;
43 EXPORT_SYMBOL(I_BDEV);
45 static sector_t max_block(struct block_device *bdev)
47 sector_t retval = ~((sector_t)0);
48 loff_t sz = i_size_read(bdev->bd_inode);
51 unsigned int size = block_size(bdev);
52 unsigned int sizebits = blksize_bits(size);
53 retval = (sz >> sizebits);
58 /* Kill _all_ buffers, dirty or not.. */
59 static void kill_bdev(struct block_device *bdev)
61 invalidate_bdev(bdev, 1);
62 truncate_inode_pages(bdev->bd_inode->i_mapping, 0);
65 int set_blocksize(struct block_device *bdev, int size)
67 /* Size must be a power of two, and between 512 and PAGE_SIZE */
68 if (size > PAGE_SIZE || size < 512 || (size & (size-1)))
71 /* Size cannot be smaller than the size supported by the device */
72 if (size < bdev_hardsect_size(bdev))
75 /* Don't change the size if it is same as current */
76 if (bdev->bd_block_size != size) {
78 bdev->bd_block_size = size;
79 bdev->bd_inode->i_blkbits = blksize_bits(size);
85 EXPORT_SYMBOL(set_blocksize);
87 int sb_set_blocksize(struct super_block *sb, int size)
89 if (set_blocksize(sb->s_bdev, size))
91 /* If we get here, we know size is power of two
92 * and it's value is between 512 and PAGE_SIZE */
93 sb->s_blocksize = size;
94 sb->s_blocksize_bits = blksize_bits(size);
95 return sb->s_blocksize;
98 EXPORT_SYMBOL(sb_set_blocksize);
100 int sb_min_blocksize(struct super_block *sb, int size)
102 int minsize = bdev_hardsect_size(sb->s_bdev);
105 return sb_set_blocksize(sb, size);
108 EXPORT_SYMBOL(sb_min_blocksize);
111 blkdev_get_block(struct inode *inode, sector_t iblock,
112 struct buffer_head *bh, int create)
114 if (iblock >= max_block(I_BDEV(inode))) {
119 * for reads, we're just trying to fill a partial page.
120 * return a hole, they will have to call get_block again
121 * before they can fill it, and they will get -EIO at that
126 bh->b_bdev = I_BDEV(inode);
127 bh->b_blocknr = iblock;
128 set_buffer_mapped(bh);
133 blkdev_get_blocks(struct inode *inode, sector_t iblock,
134 struct buffer_head *bh, int create)
136 sector_t end_block = max_block(I_BDEV(inode));
137 unsigned long max_blocks = bh->b_size >> inode->i_blkbits;
139 if ((iblock + max_blocks) > end_block) {
140 max_blocks = end_block - iblock;
141 if ((long)max_blocks <= 0) {
143 return -EIO; /* write fully beyond EOF */
145 * It is a read which is fully beyond EOF. We return
146 * a !buffer_mapped buffer
152 bh->b_bdev = I_BDEV(inode);
153 bh->b_blocknr = iblock;
154 bh->b_size = max_blocks << inode->i_blkbits;
156 set_buffer_mapped(bh);
161 blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
162 loff_t offset, unsigned long nr_segs)
164 struct file *file = iocb->ki_filp;
165 struct inode *inode = file->f_mapping->host;
167 return blockdev_direct_IO_no_locking(rw, iocb, inode, I_BDEV(inode),
168 iov, offset, nr_segs, blkdev_get_blocks, NULL);
171 static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
173 return block_write_full_page(page, blkdev_get_block, wbc);
176 static int blkdev_readpage(struct file * file, struct page * page)
178 return block_read_full_page(page, blkdev_get_block);
181 static int blkdev_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
183 return block_prepare_write(page, from, to, blkdev_get_block);
186 static int blkdev_commit_write(struct file *file, struct page *page, unsigned from, unsigned to)
188 return block_commit_write(page, from, to);
193 * for a block special file file->f_dentry->d_inode->i_size is zero
194 * so we compute the size by hand (just as in block_read/write above)
196 static loff_t block_llseek(struct file *file, loff_t offset, int origin)
198 struct inode *bd_inode = file->f_mapping->host;
202 mutex_lock(&bd_inode->i_mutex);
203 size = i_size_read(bd_inode);
210 offset += file->f_pos;
213 if (offset >= 0 && offset <= size) {
214 if (offset != file->f_pos) {
215 file->f_pos = offset;
219 mutex_unlock(&bd_inode->i_mutex);
224 * Filp is never NULL; the only case when ->fsync() is called with
225 * NULL first argument is nfsd_sync_dir() and that's not a directory.
228 static int block_fsync(struct file *filp, struct dentry *dentry, int datasync)
230 return sync_blockdev(I_BDEV(filp->f_mapping->host));
237 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock);
238 static struct kmem_cache * bdev_cachep __read_mostly;
240 static struct inode *bdev_alloc_inode(struct super_block *sb)
242 struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL);
245 return &ei->vfs_inode;
248 static void bdev_destroy_inode(struct inode *inode)
250 struct bdev_inode *bdi = BDEV_I(inode);
252 bdi->bdev.bd_inode_backing_dev_info = NULL;
253 kmem_cache_free(bdev_cachep, bdi);
256 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
258 struct bdev_inode *ei = (struct bdev_inode *) foo;
259 struct block_device *bdev = &ei->bdev;
261 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
262 SLAB_CTOR_CONSTRUCTOR)
264 memset(bdev, 0, sizeof(*bdev));
265 mutex_init(&bdev->bd_mutex);
266 mutex_init(&bdev->bd_mount_mutex);
267 INIT_LIST_HEAD(&bdev->bd_inodes);
268 INIT_LIST_HEAD(&bdev->bd_list);
270 INIT_LIST_HEAD(&bdev->bd_holder_list);
272 inode_init_once(&ei->vfs_inode);
276 static inline void __bd_forget(struct inode *inode)
278 list_del_init(&inode->i_devices);
279 inode->i_bdev = NULL;
280 inode->i_mapping = &inode->i_data;
283 static void bdev_clear_inode(struct inode *inode)
285 struct block_device *bdev = &BDEV_I(inode)->bdev;
287 spin_lock(&bdev_lock);
288 while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) {
289 __bd_forget(list_entry(p, struct inode, i_devices));
291 list_del_init(&bdev->bd_list);
292 spin_unlock(&bdev_lock);
295 static struct super_operations bdev_sops = {
296 .statfs = simple_statfs,
297 .alloc_inode = bdev_alloc_inode,
298 .destroy_inode = bdev_destroy_inode,
299 .drop_inode = generic_delete_inode,
300 .clear_inode = bdev_clear_inode,
303 static int bd_get_sb(struct file_system_type *fs_type,
304 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
306 return get_sb_pseudo(fs_type, "bdev:", &bdev_sops, 0x62646576, mnt);
309 static struct file_system_type bd_type = {
312 .kill_sb = kill_anon_super,
315 static struct vfsmount *bd_mnt __read_mostly;
316 struct super_block *blockdev_superblock;
318 void __init bdev_cache_init(void)
321 bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode),
322 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
323 SLAB_MEM_SPREAD|SLAB_PANIC),
325 err = register_filesystem(&bd_type);
327 panic("Cannot register bdev pseudo-fs");
328 bd_mnt = kern_mount(&bd_type);
329 err = PTR_ERR(bd_mnt);
331 panic("Cannot create bdev pseudo-fs");
332 blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */
336 * Most likely _very_ bad one - but then it's hardly critical for small
337 * /dev and can be fixed when somebody will need really large one.
338 * Keep in mind that it will be fed through icache hash function too.
340 static inline unsigned long hash(dev_t dev)
342 return MAJOR(dev)+MINOR(dev);
345 static int bdev_test(struct inode *inode, void *data)
347 return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data;
350 static int bdev_set(struct inode *inode, void *data)
352 BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data;
356 static LIST_HEAD(all_bdevs);
358 static struct lock_class_key bdev_part_lock_key;
360 struct block_device *bdget(dev_t dev)
362 struct block_device *bdev;
364 struct gendisk *disk;
367 inode = iget5_locked(bd_mnt->mnt_sb, hash(dev),
368 bdev_test, bdev_set, &dev);
373 bdev = &BDEV_I(inode)->bdev;
375 if (inode->i_state & I_NEW) {
376 bdev->bd_contains = NULL;
377 bdev->bd_inode = inode;
378 bdev->bd_block_size = (1 << inode->i_blkbits);
379 bdev->bd_part_count = 0;
380 bdev->bd_invalidated = 0;
381 inode->i_mode = S_IFBLK;
383 inode->i_bdev = bdev;
384 inode->i_data.a_ops = &def_blk_aops;
385 mapping_set_gfp_mask(&inode->i_data, GFP_USER);
386 inode->i_data.backing_dev_info = &default_backing_dev_info;
387 spin_lock(&bdev_lock);
388 list_add(&bdev->bd_list, &all_bdevs);
389 spin_unlock(&bdev_lock);
390 unlock_new_inode(inode);
391 mutex_init(&bdev->bd_mutex);
392 disk = get_gendisk(dev, &part);
394 lockdep_set_class(&bdev->bd_mutex, &bdev_part_lock_key);
400 EXPORT_SYMBOL(bdget);
402 long nr_blockdev_pages(void)
406 spin_lock(&bdev_lock);
407 list_for_each(p, &all_bdevs) {
408 struct block_device *bdev;
409 bdev = list_entry(p, struct block_device, bd_list);
410 ret += bdev->bd_inode->i_mapping->nrpages;
412 spin_unlock(&bdev_lock);
416 void bdput(struct block_device *bdev)
418 iput(bdev->bd_inode);
421 EXPORT_SYMBOL(bdput);
423 static struct block_device *bd_acquire(struct inode *inode)
425 struct block_device *bdev;
427 spin_lock(&bdev_lock);
428 bdev = inode->i_bdev;
430 atomic_inc(&bdev->bd_inode->i_count);
431 spin_unlock(&bdev_lock);
434 spin_unlock(&bdev_lock);
436 bdev = bdget(inode->i_rdev);
438 spin_lock(&bdev_lock);
439 if (!inode->i_bdev) {
441 * We take an additional bd_inode->i_count for inode,
442 * and it's released in clear_inode() of inode.
443 * So, we can access it via ->i_mapping always
446 atomic_inc(&bdev->bd_inode->i_count);
447 inode->i_bdev = bdev;
448 inode->i_mapping = bdev->bd_inode->i_mapping;
449 list_add(&inode->i_devices, &bdev->bd_inodes);
451 spin_unlock(&bdev_lock);
456 /* Call when you free inode */
458 void bd_forget(struct inode *inode)
460 struct block_device *bdev = NULL;
462 spin_lock(&bdev_lock);
464 if (inode->i_sb != blockdev_superblock)
465 bdev = inode->i_bdev;
468 spin_unlock(&bdev_lock);
471 iput(bdev->bd_inode);
474 int bd_claim(struct block_device *bdev, void *holder)
477 spin_lock(&bdev_lock);
479 /* first decide result */
480 if (bdev->bd_holder == holder)
481 res = 0; /* already a holder */
482 else if (bdev->bd_holder != NULL)
483 res = -EBUSY; /* held by someone else */
484 else if (bdev->bd_contains == bdev)
485 res = 0; /* is a whole device which isn't held */
487 else if (bdev->bd_contains->bd_holder == bd_claim)
488 res = 0; /* is a partition of a device that is being partitioned */
489 else if (bdev->bd_contains->bd_holder != NULL)
490 res = -EBUSY; /* is a partition of a held device */
492 res = 0; /* is a partition of an un-held device */
494 /* now impose change */
496 /* note that for a whole device bd_holders
497 * will be incremented twice, and bd_holder will
498 * be set to bd_claim before being set to holder
500 bdev->bd_contains->bd_holders ++;
501 bdev->bd_contains->bd_holder = bd_claim;
503 bdev->bd_holder = holder;
505 spin_unlock(&bdev_lock);
509 EXPORT_SYMBOL(bd_claim);
511 void bd_release(struct block_device *bdev)
513 spin_lock(&bdev_lock);
514 if (!--bdev->bd_contains->bd_holders)
515 bdev->bd_contains->bd_holder = NULL;
516 if (!--bdev->bd_holders)
517 bdev->bd_holder = NULL;
518 spin_unlock(&bdev_lock);
521 EXPORT_SYMBOL(bd_release);
525 * Functions for bd_claim_by_kobject / bd_release_from_kobject
527 * If a kobject is passed to bd_claim_by_kobject()
528 * and the kobject has a parent directory,
529 * following symlinks are created:
530 * o from the kobject to the claimed bdev
531 * o from "holders" directory of the bdev to the parent of the kobject
532 * bd_release_from_kobject() removes these symlinks.
535 * If /dev/dm-0 maps to /dev/sda, kobject corresponding to
536 * /sys/block/dm-0/slaves is passed to bd_claim_by_kobject(), then:
537 * /sys/block/dm-0/slaves/sda --> /sys/block/sda
538 * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
541 static struct kobject *bdev_get_kobj(struct block_device *bdev)
543 if (bdev->bd_contains != bdev)
544 return kobject_get(&bdev->bd_part->kobj);
546 return kobject_get(&bdev->bd_disk->kobj);
549 static struct kobject *bdev_get_holder(struct block_device *bdev)
551 if (bdev->bd_contains != bdev)
552 return kobject_get(bdev->bd_part->holder_dir);
554 return kobject_get(bdev->bd_disk->holder_dir);
557 static int add_symlink(struct kobject *from, struct kobject *to)
561 return sysfs_create_link(from, to, kobject_name(to));
564 static void del_symlink(struct kobject *from, struct kobject *to)
568 sysfs_remove_link(from, kobject_name(to));
572 * 'struct bd_holder' contains pointers to kobjects symlinked by
573 * bd_claim_by_kobject.
574 * It's connected to bd_holder_list which is protected by bdev->bd_sem.
577 struct list_head list; /* chain of holders of the bdev */
578 int count; /* references from the holder */
579 struct kobject *sdir; /* holder object, e.g. "/block/dm-0/slaves" */
580 struct kobject *hdev; /* e.g. "/block/dm-0" */
581 struct kobject *hdir; /* e.g. "/block/sda/holders" */
582 struct kobject *sdev; /* e.g. "/block/sda" */
586 * Get references of related kobjects at once.
587 * Returns 1 on success. 0 on failure.
589 * Should call bd_holder_release_dirs() after successful use.
591 static int bd_holder_grab_dirs(struct block_device *bdev,
592 struct bd_holder *bo)
597 bo->sdir = kobject_get(bo->sdir);
601 bo->hdev = kobject_get(bo->sdir->parent);
605 bo->sdev = bdev_get_kobj(bdev);
609 bo->hdir = bdev_get_holder(bdev);
616 kobject_put(bo->sdev);
618 kobject_put(bo->hdev);
620 kobject_put(bo->sdir);
625 /* Put references of related kobjects at once. */
626 static void bd_holder_release_dirs(struct bd_holder *bo)
628 kobject_put(bo->hdir);
629 kobject_put(bo->sdev);
630 kobject_put(bo->hdev);
631 kobject_put(bo->sdir);
634 static struct bd_holder *alloc_bd_holder(struct kobject *kobj)
636 struct bd_holder *bo;
638 bo = kzalloc(sizeof(*bo), GFP_KERNEL);
648 static void free_bd_holder(struct bd_holder *bo)
654 * find_bd_holder - find matching struct bd_holder from the block device
656 * @bdev: struct block device to be searched
657 * @bo: target struct bd_holder
659 * Returns matching entry with @bo in @bdev->bd_holder_list.
660 * If found, increment the reference count and return the pointer.
661 * If not found, returns NULL.
663 static struct bd_holder *find_bd_holder(struct block_device *bdev,
664 struct bd_holder *bo)
666 struct bd_holder *tmp;
668 list_for_each_entry(tmp, &bdev->bd_holder_list, list)
669 if (tmp->sdir == bo->sdir) {
678 * add_bd_holder - create sysfs symlinks for bd_claim() relationship
680 * @bdev: block device to be bd_claimed
681 * @bo: preallocated and initialized by alloc_bd_holder()
683 * Add @bo to @bdev->bd_holder_list, create symlinks.
685 * Returns 0 if symlinks are created.
686 * Returns -ve if something fails.
688 static int add_bd_holder(struct block_device *bdev, struct bd_holder *bo)
695 if (!bd_holder_grab_dirs(bdev, bo))
698 ret = add_symlink(bo->sdir, bo->sdev);
700 ret = add_symlink(bo->hdir, bo->hdev);
702 del_symlink(bo->sdir, bo->sdev);
705 list_add_tail(&bo->list, &bdev->bd_holder_list);
710 * del_bd_holder - delete sysfs symlinks for bd_claim() relationship
712 * @bdev: block device to be bd_claimed
713 * @kobj: holder's kobject
715 * If there is matching entry with @kobj in @bdev->bd_holder_list
716 * and no other bd_claim() from the same kobject,
717 * remove the struct bd_holder from the list, delete symlinks for it.
719 * Returns a pointer to the struct bd_holder when it's removed from the list
720 * and ready to be freed.
721 * Returns NULL if matching claim isn't found or there is other bd_claim()
722 * by the same kobject.
724 static struct bd_holder *del_bd_holder(struct block_device *bdev,
725 struct kobject *kobj)
727 struct bd_holder *bo;
729 list_for_each_entry(bo, &bdev->bd_holder_list, list) {
730 if (bo->sdir == kobj) {
732 BUG_ON(bo->count < 0);
735 del_symlink(bo->sdir, bo->sdev);
736 del_symlink(bo->hdir, bo->hdev);
737 bd_holder_release_dirs(bo);
748 * bd_claim_by_kobject - bd_claim() with additional kobject signature
750 * @bdev: block device to be claimed
751 * @holder: holder's signature
752 * @kobj: holder's kobject
754 * Do bd_claim() and if it succeeds, create sysfs symlinks between
755 * the bdev and the holder's kobject.
756 * Use bd_release_from_kobject() when relesing the claimed bdev.
758 * Returns 0 on success. (same as bd_claim())
759 * Returns errno on failure.
761 static int bd_claim_by_kobject(struct block_device *bdev, void *holder,
762 struct kobject *kobj)
765 struct bd_holder *bo, *found;
770 bo = alloc_bd_holder(kobj);
774 mutex_lock(&bdev->bd_mutex);
775 res = bd_claim(bdev, holder);
777 found = find_bd_holder(bdev, bo);
779 res = add_bd_holder(bdev, bo);
787 mutex_unlock(&bdev->bd_mutex);
793 * bd_release_from_kobject - bd_release() with additional kobject signature
795 * @bdev: block device to be released
796 * @kobj: holder's kobject
798 * Do bd_release() and remove sysfs symlinks created by bd_claim_by_kobject().
800 static void bd_release_from_kobject(struct block_device *bdev,
801 struct kobject *kobj)
803 struct bd_holder *bo;
808 mutex_lock(&bdev->bd_mutex);
810 if ((bo = del_bd_holder(bdev, kobj)))
812 mutex_unlock(&bdev->bd_mutex);
816 * bd_claim_by_disk - wrapper function for bd_claim_by_kobject()
818 * @bdev: block device to be claimed
819 * @holder: holder's signature
820 * @disk: holder's gendisk
822 * Call bd_claim_by_kobject() with getting @disk->slave_dir.
824 int bd_claim_by_disk(struct block_device *bdev, void *holder,
825 struct gendisk *disk)
827 return bd_claim_by_kobject(bdev, holder, kobject_get(disk->slave_dir));
829 EXPORT_SYMBOL_GPL(bd_claim_by_disk);
832 * bd_release_from_disk - wrapper function for bd_release_from_kobject()
834 * @bdev: block device to be claimed
835 * @disk: holder's gendisk
837 * Call bd_release_from_kobject() and put @disk->slave_dir.
839 void bd_release_from_disk(struct block_device *bdev, struct gendisk *disk)
841 bd_release_from_kobject(bdev, disk->slave_dir);
842 kobject_put(disk->slave_dir);
844 EXPORT_SYMBOL_GPL(bd_release_from_disk);
848 * Tries to open block device by device number. Use it ONLY if you
849 * really do not have anything better - i.e. when you are behind a
850 * truly sucky interface and all you are given is a device number. _Never_
851 * to be used for internal purposes. If you ever need it - reconsider
854 struct block_device *open_by_devnum(dev_t dev, unsigned mode)
856 struct block_device *bdev = bdget(dev);
858 int flags = mode & FMODE_WRITE ? O_RDWR : O_RDONLY;
860 err = blkdev_get(bdev, mode, flags);
861 return err ? ERR_PTR(err) : bdev;
864 EXPORT_SYMBOL(open_by_devnum);
867 * This routine checks whether a removable media has been changed,
868 * and invalidates all buffer-cache-entries in that case. This
869 * is a relatively slow routine, so we have to try to minimize using
870 * it. Thus it is called only upon a 'mount' or 'open'. This
871 * is the best way of combining speed and utility, I think.
872 * People changing diskettes in the middle of an operation deserve
875 int check_disk_change(struct block_device *bdev)
877 struct gendisk *disk = bdev->bd_disk;
878 struct block_device_operations * bdops = disk->fops;
880 if (!bdops->media_changed)
882 if (!bdops->media_changed(bdev->bd_disk))
885 if (__invalidate_device(bdev))
886 printk("VFS: busy inodes on changed media.\n");
888 if (bdops->revalidate_disk)
889 bdops->revalidate_disk(bdev->bd_disk);
890 if (bdev->bd_disk->minors > 1)
891 bdev->bd_invalidated = 1;
895 EXPORT_SYMBOL(check_disk_change);
897 void bd_set_size(struct block_device *bdev, loff_t size)
899 unsigned bsize = bdev_hardsect_size(bdev);
901 bdev->bd_inode->i_size = size;
902 while (bsize < PAGE_CACHE_SIZE) {
907 bdev->bd_block_size = bsize;
908 bdev->bd_inode->i_blkbits = blksize_bits(bsize);
910 EXPORT_SYMBOL(bd_set_size);
912 static int do_open(struct block_device *bdev, struct file *file)
914 struct module *owner = NULL;
915 struct gendisk *disk;
919 file->f_mapping = bdev->bd_inode->i_mapping;
921 disk = get_gendisk(bdev->bd_dev, &part);
927 owner = disk->fops->owner;
929 mutex_lock(&bdev->bd_mutex);
930 if (!bdev->bd_openers) {
931 bdev->bd_disk = disk;
932 bdev->bd_contains = bdev;
934 struct backing_dev_info *bdi;
935 if (disk->fops->open) {
936 ret = disk->fops->open(bdev->bd_inode, file);
940 if (!bdev->bd_openers) {
941 bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
942 bdi = blk_get_backing_dev_info(bdev);
944 bdi = &default_backing_dev_info;
945 bdev->bd_inode->i_data.backing_dev_info = bdi;
947 if (bdev->bd_invalidated)
948 rescan_partitions(disk, bdev);
951 struct block_device *whole;
952 whole = bdget_disk(disk, 0);
956 ret = blkdev_get(whole, file->f_mode, file->f_flags);
959 bdev->bd_contains = whole;
960 mutex_lock(&whole->bd_mutex);
961 whole->bd_part_count++;
962 p = disk->part[part - 1];
963 bdev->bd_inode->i_data.backing_dev_info =
964 whole->bd_inode->i_data.backing_dev_info;
965 if (!(disk->flags & GENHD_FL_UP) || !p || !p->nr_sects) {
966 whole->bd_part_count--;
967 mutex_unlock(&whole->bd_mutex);
971 kobject_get(&p->kobj);
973 bd_set_size(bdev, (loff_t) p->nr_sects << 9);
974 mutex_unlock(&whole->bd_mutex);
979 if (bdev->bd_contains == bdev) {
980 if (bdev->bd_disk->fops->open) {
981 ret = bdev->bd_disk->fops->open(bdev->bd_inode, file);
985 if (bdev->bd_invalidated)
986 rescan_partitions(bdev->bd_disk, bdev);
988 mutex_lock(&bdev->bd_contains->bd_mutex);
989 bdev->bd_contains->bd_part_count++;
990 mutex_unlock(&bdev->bd_contains->bd_mutex);
994 mutex_unlock(&bdev->bd_mutex);
999 bdev->bd_disk = NULL;
1000 bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
1001 if (bdev != bdev->bd_contains)
1002 blkdev_put(bdev->bd_contains);
1003 bdev->bd_contains = NULL;
1007 mutex_unlock(&bdev->bd_mutex);
1014 int blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags)
1017 * This crockload is due to bad choice of ->open() type.
1019 * For now, block device ->open() routine must _not_
1020 * examine anything in 'inode' argument except ->i_rdev.
1022 struct file fake_file = {};
1023 struct dentry fake_dentry = {};
1024 fake_file.f_mode = mode;
1025 fake_file.f_flags = flags;
1026 fake_file.f_dentry = &fake_dentry;
1027 fake_dentry.d_inode = bdev->bd_inode;
1029 return do_open(bdev, &fake_file);
1032 EXPORT_SYMBOL(blkdev_get);
1034 static int blkdev_open(struct inode * inode, struct file * filp)
1036 struct block_device *bdev;
1040 * Preserve backwards compatibility and allow large file access
1041 * even if userspace doesn't ask for it explicitly. Some mkfs
1042 * binary needs it. We might want to drop this workaround
1043 * during an unstable branch.
1045 filp->f_flags |= O_LARGEFILE;
1047 bdev = bd_acquire(inode);
1051 res = do_open(bdev, filp);
1055 if (!(filp->f_flags & O_EXCL) )
1058 if (!(res = bd_claim(bdev, filp)))
1065 int blkdev_put(struct block_device *bdev)
1068 struct inode *bd_inode = bdev->bd_inode;
1069 struct gendisk *disk = bdev->bd_disk;
1071 mutex_lock(&bdev->bd_mutex);
1073 if (!--bdev->bd_openers) {
1074 sync_blockdev(bdev);
1077 if (bdev->bd_contains == bdev) {
1078 if (disk->fops->release)
1079 ret = disk->fops->release(bd_inode, NULL);
1081 mutex_lock(&bdev->bd_contains->bd_mutex);
1082 bdev->bd_contains->bd_part_count--;
1083 mutex_unlock(&bdev->bd_contains->bd_mutex);
1085 if (!bdev->bd_openers) {
1086 struct module *owner = disk->fops->owner;
1091 if (bdev->bd_contains != bdev) {
1092 kobject_put(&bdev->bd_part->kobj);
1093 bdev->bd_part = NULL;
1095 bdev->bd_disk = NULL;
1096 bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
1097 if (bdev != bdev->bd_contains) {
1098 blkdev_put(bdev->bd_contains);
1100 bdev->bd_contains = NULL;
1103 mutex_unlock(&bdev->bd_mutex);
1108 EXPORT_SYMBOL(blkdev_put);
1110 static int blkdev_close(struct inode * inode, struct file * filp)
1112 struct block_device *bdev = I_BDEV(filp->f_mapping->host);
1113 if (bdev->bd_holder == filp)
1115 return blkdev_put(bdev);
1118 static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
1120 return blkdev_ioctl(file->f_mapping->host, file, cmd, arg);
1123 const struct address_space_operations def_blk_aops = {
1124 .readpage = blkdev_readpage,
1125 .writepage = blkdev_writepage,
1126 .sync_page = block_sync_page,
1127 .prepare_write = blkdev_prepare_write,
1128 .commit_write = blkdev_commit_write,
1129 .writepages = generic_writepages,
1130 .direct_IO = blkdev_direct_IO,
1133 const struct file_operations def_blk_fops = {
1134 .open = blkdev_open,
1135 .release = blkdev_close,
1136 .llseek = block_llseek,
1137 .read = do_sync_read,
1138 .write = do_sync_write,
1139 .aio_read = generic_file_aio_read,
1140 .aio_write = generic_file_aio_write_nolock,
1141 .mmap = generic_file_mmap,
1142 .fsync = block_fsync,
1143 .unlocked_ioctl = block_ioctl,
1144 #ifdef CONFIG_COMPAT
1145 .compat_ioctl = compat_blkdev_ioctl,
1147 .sendfile = generic_file_sendfile,
1148 .splice_read = generic_file_splice_read,
1149 .splice_write = generic_file_splice_write,
1152 int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)
1155 mm_segment_t old_fs = get_fs();
1157 res = blkdev_ioctl(bdev->bd_inode, NULL, cmd, arg);
1162 EXPORT_SYMBOL(ioctl_by_bdev);
1165 * lookup_bdev - lookup a struct block_device by name
1167 * @path: special file representing the block device
1169 * Get a reference to the blockdevice at @path in the current
1170 * namespace if possible and return it. Return ERR_PTR(error)
1173 struct block_device *lookup_bdev(const char *path)
1175 struct block_device *bdev;
1176 struct inode *inode;
1177 struct nameidata nd;
1180 if (!path || !*path)
1181 return ERR_PTR(-EINVAL);
1183 error = path_lookup(path, LOOKUP_FOLLOW, &nd);
1185 return ERR_PTR(error);
1187 inode = nd.dentry->d_inode;
1189 if (!S_ISBLK(inode->i_mode))
1192 if (nd.mnt->mnt_flags & MNT_NODEV)
1195 bdev = bd_acquire(inode);
1202 bdev = ERR_PTR(error);
1207 * open_bdev_excl - open a block device by name and set it up for use
1209 * @path: special file representing the block device
1210 * @flags: %MS_RDONLY for opening read-only
1211 * @holder: owner for exclusion
1213 * Open the blockdevice described by the special file at @path, claim it
1216 struct block_device *open_bdev_excl(const char *path, int flags, void *holder)
1218 struct block_device *bdev;
1219 mode_t mode = FMODE_READ;
1222 bdev = lookup_bdev(path);
1226 if (!(flags & MS_RDONLY))
1227 mode |= FMODE_WRITE;
1228 error = blkdev_get(bdev, mode, 0);
1230 return ERR_PTR(error);
1232 if (!(flags & MS_RDONLY) && bdev_read_only(bdev))
1234 error = bd_claim(bdev, holder);
1242 return ERR_PTR(error);
1245 EXPORT_SYMBOL(open_bdev_excl);
1248 * close_bdev_excl - release a blockdevice openen by open_bdev_excl()
1250 * @bdev: blockdevice to close
1252 * This is the counterpart to open_bdev_excl().
1254 void close_bdev_excl(struct block_device *bdev)
1260 EXPORT_SYMBOL(close_bdev_excl);
1262 int __invalidate_device(struct block_device *bdev)
1264 struct super_block *sb = get_super(bdev);
1269 * no need to lock the super, get_super holds the
1270 * read mutex so the filesystem cannot go away
1271 * under us (->put_super runs with the write lock
1274 shrink_dcache_sb(sb);
1275 res = invalidate_inodes(sb);
1278 invalidate_bdev(bdev, 0);
1281 EXPORT_SYMBOL(__invalidate_device);