Merge branch 'cleanup-bd_claim' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into for-2.6.38/core

block/ioctl.c

···
 			return -EINVAL;
 		if (get_user(n, (int __user *) arg))
 			return -EFAULT;
-		if (!(mode & FMODE_EXCL) && bd_claim(bdev, &bdev) < 0)
+		if (!(mode & FMODE_EXCL) &&
+		    blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
 			return -EBUSY;
 		ret = set_blocksize(bdev, n);
 		if (!(mode & FMODE_EXCL))
-			bd_release(bdev);
+			blkdev_put(bdev, mode | FMODE_EXCL);
 		return ret;
 	case BLKPG:
 		ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);

drivers/block/drbd/drbd_int.h

···
 struct drbd_backing_dev {
 	struct block_device *backing_bdev;
 	struct block_device *md_bdev;
-	struct file *lo_file;
-	struct file *md_file;
 	struct drbd_md md;
 	struct disk_conf dc; /* The user provided config... */
 	sector_t known_size; /* last known size of that backing device */

drivers/block/drbd/drbd_main.c

···
 	if (ldev == NULL)
 		return;
 
-	bd_release(ldev->backing_bdev);
-	bd_release(ldev->md_bdev);
-
-	fput(ldev->lo_file);
-	fput(ldev->md_file);
+	blkdev_put(ldev->backing_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
+	blkdev_put(ldev->md_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
 
 	kfree(ldev);
 }

drivers/block/drbd/drbd_nl.c

···
 	sector_t max_possible_sectors;
 	sector_t min_md_device_sectors;
 	struct drbd_backing_dev *nbc = NULL; /* new_backing_conf */
-	struct inode *inode, *inode2;
+	struct block_device *bdev;
 	struct lru_cache *resync_lru = NULL;
 	union drbd_state ns, os;
 	unsigned int max_seg_s;
···
 		}
 	}
 
-	nbc->lo_file = filp_open(nbc->dc.backing_dev, O_RDWR, 0);
-	if (IS_ERR(nbc->lo_file)) {
+	bdev = blkdev_get_by_path(nbc->dc.backing_dev,
+				  FMODE_READ | FMODE_WRITE | FMODE_EXCL, mdev);
+	if (IS_ERR(bdev)) {
 		dev_err(DEV, "open(\"%s\") failed with %ld\n", nbc->dc.backing_dev,
-		    PTR_ERR(nbc->lo_file));
-		nbc->lo_file = NULL;
+			PTR_ERR(bdev));
 		retcode = ERR_OPEN_DISK;
 		goto fail;
 	}
+	nbc->backing_bdev = bdev;
 
-	inode = nbc->lo_file->f_dentry->d_inode;
-
-	if (!S_ISBLK(inode->i_mode)) {
-		retcode = ERR_DISK_NOT_BDEV;
-		goto fail;
-	}
-
-	nbc->md_file = filp_open(nbc->dc.meta_dev, O_RDWR, 0);
-	if (IS_ERR(nbc->md_file)) {
+	/*
+	 * meta_dev_idx >= 0: external fixed size, possibly multiple
+	 * drbd sharing one meta device.  TODO in that case, paranoia
+	 * check that [md_bdev, meta_dev_idx] is not yet used by some
+	 * other drbd minor!  (if you use drbd.conf + drbdadm, that
+	 * should check it for you already; but if you don't, or
+	 * someone fooled it, we need to double check here)
+	 */
+	bdev = blkdev_get_by_path(nbc->dc.meta_dev,
+				  FMODE_READ | FMODE_WRITE | FMODE_EXCL,
+				  (nbc->dc.meta_dev_idx < 0) ?
+				  (void *)mdev : (void *)drbd_m_holder);
+	if (IS_ERR(bdev)) {
 		dev_err(DEV, "open(\"%s\") failed with %ld\n", nbc->dc.meta_dev,
-		    PTR_ERR(nbc->md_file));
-		nbc->md_file = NULL;
+			PTR_ERR(bdev));
 		retcode = ERR_OPEN_MD_DISK;
 		goto fail;
 	}
+	nbc->md_bdev = bdev;
 
-	inode2 = nbc->md_file->f_dentry->d_inode;
-
-	if (!S_ISBLK(inode2->i_mode)) {
-		retcode = ERR_MD_NOT_BDEV;
-		goto fail;
-	}
-
-	nbc->backing_bdev = inode->i_bdev;
-	if (bd_claim(nbc->backing_bdev, mdev)) {
-		printk(KERN_ERR "drbd: bd_claim(%p,%p); failed [%p;%p;%u]\n",
-		       nbc->backing_bdev, mdev,
-		       nbc->backing_bdev->bd_holder,
-		       nbc->backing_bdev->bd_contains->bd_holder,
-		       nbc->backing_bdev->bd_holders);
-		retcode = ERR_BDCLAIM_DISK;
+	if ((nbc->backing_bdev == nbc->md_bdev) !=
+	    (nbc->dc.meta_dev_idx == DRBD_MD_INDEX_INTERNAL ||
+	     nbc->dc.meta_dev_idx == DRBD_MD_INDEX_FLEX_INT)) {
+		retcode = ERR_MD_IDX_INVALID;
 		goto fail;
 	}
 
···
 			offsetof(struct bm_extent, lce));
 	if (!resync_lru) {
 		retcode = ERR_NOMEM;
-		goto release_bdev_fail;
-	}
-
-	/* meta_dev_idx >= 0: external fixed size,
-	 * possibly multiple drbd sharing one meta device.
-	 * TODO in that case, paranoia check that [md_bdev, meta_dev_idx] is
-	 * not yet used by some other drbd minor!
-	 * (if you use drbd.conf + drbdadm,
-	 * that should check it for you already; but if you don't, or someone
-	 * fooled it, we need to double check here) */
-	nbc->md_bdev = inode2->i_bdev;
-	if (bd_claim(nbc->md_bdev, (nbc->dc.meta_dev_idx < 0) ? (void *)mdev
-				: (void *) drbd_m_holder)) {
-		retcode = ERR_BDCLAIM_MD_DISK;
-		goto release_bdev_fail;
-	}
-
-	if ((nbc->backing_bdev == nbc->md_bdev) !=
-	    (nbc->dc.meta_dev_idx == DRBD_MD_INDEX_INTERNAL ||
-	     nbc->dc.meta_dev_idx == DRBD_MD_INDEX_FLEX_INT)) {
-		retcode = ERR_MD_IDX_INVALID;
-		goto release_bdev2_fail;
+		goto fail;
 	}
 
 	/* RT - for drbd_get_max_capacity() DRBD_MD_INDEX_FLEX_INT */
···
 			(unsigned long long) drbd_get_max_capacity(nbc),
 			(unsigned long long) nbc->dc.disk_size);
 		retcode = ERR_DISK_TO_SMALL;
-		goto release_bdev2_fail;
+		goto fail;
 	}
 
 	if (nbc->dc.meta_dev_idx < 0) {
···
 		dev_warn(DEV, "refusing attach: md-device too small, "
 		     "at least %llu sectors needed for this meta-disk type\n",
 		     (unsigned long long) min_md_device_sectors);
-		goto release_bdev2_fail;
+		goto fail;
 	}
 
 	/* Make sure the new disk is big enough
···
 	if (drbd_get_max_capacity(nbc) <
 	    drbd_get_capacity(mdev->this_bdev)) {
 		retcode = ERR_DISK_TO_SMALL;
-		goto release_bdev2_fail;
+		goto fail;
 	}
 
 	nbc->known_size = drbd_get_capacity(nbc->backing_bdev);
···
 	retcode = _drbd_request_state(mdev, NS(disk, D_ATTACHING), CS_VERBOSE);
 	drbd_resume_io(mdev);
 	if (retcode < SS_SUCCESS)
-		goto release_bdev2_fail;
+		goto fail;
 
 	if (!get_ldev_if_state(mdev, D_ATTACHING))
 		goto force_diskless;
···
  force_diskless:
 	drbd_force_state(mdev, NS(disk, D_FAILED));
 	drbd_md_sync(mdev);
- release_bdev2_fail:
-	if (nbc)
-		bd_release(nbc->md_bdev);
- release_bdev_fail:
-	if (nbc)
-		bd_release(nbc->backing_bdev);
  fail:
 	if (nbc) {
-		if (nbc->lo_file)
-			fput(nbc->lo_file);
-		if (nbc->md_file)
-			fput(nbc->md_file);
+		if (nbc->backing_bdev)
+			blkdev_put(nbc->backing_bdev,
+				   FMODE_READ | FMODE_WRITE | FMODE_EXCL);
+		if (nbc->md_bdev)
+			blkdev_put(nbc->md_bdev,
+				   FMODE_READ | FMODE_WRITE | FMODE_EXCL);
 		kfree(nbc);
 	}
 	lc_destroy(resync_lru);

drivers/block/pktcdvd.c

···
 	 * so bdget() can't fail.
 	 */
 	bdget(pd->bdev->bd_dev);
-	if ((ret = blkdev_get(pd->bdev, FMODE_READ)))
+	if ((ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd)))
 		goto out;
-
-	if ((ret = bd_claim(pd->bdev, pd)))
-		goto out_putdev;
 
 	if ((ret = pkt_get_last_written(pd, &lba))) {
 		printk(DRIVER_NAME": pkt_get_last_written failed\n");
-		goto out_unclaim;
+		goto out_putdev;
 	}
 
 	set_capacity(pd->disk, lba << 2);
···
 	q = bdev_get_queue(pd->bdev);
 	if (write) {
 		if ((ret = pkt_open_write(pd)))
-			goto out_unclaim;
+			goto out_putdev;
 		/*
 		 * Some CDRW drives can not handle writes larger than one packet,
 		 * even if the size is a multiple of the packet size.
···
 	}
 
 	if ((ret = pkt_set_segment_merging(pd, q)))
-		goto out_unclaim;
+		goto out_putdev;
 
 	if (write) {
 		if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
 			printk(DRIVER_NAME": not enough memory for buffers\n");
 			ret = -ENOMEM;
-			goto out_unclaim;
+			goto out_putdev;
 		}
 		printk(DRIVER_NAME": %lukB available on disc\n", lba << 1);
 	}
 
 	return 0;
 
-out_unclaim:
-	bd_release(pd->bdev);
 out_putdev:
-	blkdev_put(pd->bdev, FMODE_READ);
+	blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
 out:
 	return ret;
 }
···
 	pkt_lock_door(pd, 0);
 
 	pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
-	bd_release(pd->bdev);
-	blkdev_put(pd->bdev, FMODE_READ);
+	blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
 
 	pkt_shrink_pktlist(pd);
 }
···
 	bdev = bdget(dev);
 	if (!bdev)
 		return -ENOMEM;
-	ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY);
+	ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL);
 	if (ret)
 		return ret;
 

drivers/char/raw.c

···
 	if (!bdev)
 		goto out;
 	igrab(bdev->bd_inode);
-	err = blkdev_get(bdev, filp->f_mode);
+	err = blkdev_get(bdev, filp->f_mode | FMODE_EXCL, raw_open);
 	if (err)
 		goto out;
-	err = bd_claim(bdev, raw_open);
-	if (err)
-		goto out1;
 	err = set_blocksize(bdev, bdev_logical_block_size(bdev));
 	if (err)
-		goto out2;
+		goto out1;
 	filp->f_flags |= O_DIRECT;
 	filp->f_mapping = bdev->bd_inode->i_mapping;
 	if (++raw_devices[minor].inuse == 1)
···
 	mutex_unlock(&raw_mutex);
 	return 0;
 
-out2:
-	bd_release(bdev);
 out1:
-	blkdev_put(bdev, filp->f_mode);
+	blkdev_put(bdev, filp->f_mode | FMODE_EXCL);
 out:
 	mutex_unlock(&raw_mutex);
 	return err;
···
 	}
 	mutex_unlock(&raw_mutex);
 
-	bd_release(bdev);
-	blkdev_put(bdev, filp->f_mode);
+	blkdev_put(bdev, filp->f_mode | FMODE_EXCL);
 	return 0;
 }
 

drivers/md/dm-table.c

···
 
 	BUG_ON(d->dm_dev.bdev);
 
-	bdev = open_by_devnum(dev, d->dm_dev.mode);
+	bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
 	if (IS_ERR(bdev))
 		return PTR_ERR(bdev);
-	r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md));
-	if (r)
-		blkdev_put(bdev, d->dm_dev.mode);
-	else
-		d->dm_dev.bdev = bdev;
-	return r;
+
+	r = bd_link_disk_holder(bdev, dm_disk(md));
+	if (r) {
+		blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
+		return r;
+	}
+
+	d->dm_dev.bdev = bdev;
+	return 0;
 }
 
 /*
···
 	if (!d->dm_dev.bdev)
 		return;
 
-	bd_release_from_disk(d->dm_dev.bdev, dm_disk(md));
-	blkdev_put(d->dm_dev.bdev, d->dm_dev.mode);
+	blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
 	d->dm_dev.bdev = NULL;
 }
 

drivers/md/md.c

···
 	rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
 
 	list_add_rcu(&rdev->same_set, &mddev->disks);
-	bd_claim_by_disk(rdev->bdev, rdev->bdev->bd_holder, mddev->gendisk);
+	bd_link_disk_holder(rdev->bdev, mddev->gendisk);
 
 	/* May as well allow recovery to be retried once */
 	mddev->recovery_disabled = 0;
···
 		MD_BUG();
 		return;
 	}
-	bd_release_from_disk(rdev->bdev, rdev->mddev->gendisk);
 	list_del_rcu(&rdev->same_set);
 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
 	rdev->mddev = NULL;
···
 	struct block_device *bdev;
 	char b[BDEVNAME_SIZE];
 
-	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
+	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
+				 shared ? (mdk_rdev_t *)lock_rdev : rdev);
 	if (IS_ERR(bdev)) {
 		printk(KERN_ERR "md: could not open %s.\n",
 			__bdevname(dev, b));
 		return PTR_ERR(bdev);
-	}
-	err = bd_claim(bdev, shared ? (mdk_rdev_t *)lock_rdev : rdev);
-	if (err) {
-		printk(KERN_ERR "md: could not bd_claim %s.\n",
-			bdevname(bdev, b));
-		blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
-		return err;
 	}
 	if (!shared)
 		set_bit(AllReserved, &rdev->flags);
···
 	rdev->bdev = NULL;
 	if (!bdev)
 		MD_BUG();
-	bd_release(bdev);
-	blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
+	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 }
 
 void md_autodetect_dev(dev_t dev);

drivers/mtd/devices/block2mtd.c

···
 	if (dev->blkdev) {
 		invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
 					0, -1);
-		close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
+		blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 	}
 
 	kfree(dev);
···
 /* FIXME: ensure that mtd->size % erase_size == 0 */
 static struct block2mtd_dev *add_device(char *devname, int erase_size)
 {
+	const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
 	struct block_device *bdev;
 	struct block2mtd_dev *dev;
 	char *name;
···
 		return NULL;
 
 	/* Get a handle on the device */
-	bdev = open_bdev_exclusive(devname, FMODE_READ|FMODE_WRITE, NULL);
+	bdev = blkdev_get_by_path(devname, mode, dev);
 #ifndef MODULE
 	if (IS_ERR(bdev)) {
 
···
 		   to resolve the device name by other means. */
 
 		dev_t devt = name_to_dev_t(devname);
-		if (devt) {
-			bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
-		}
+		if (devt)
+			bdev = blkdev_get_by_dev(devt, mode, dev);
 	}
 #endif
 

drivers/s390/block/dasd_genhd.c

···
 	struct block_device *bdev;
 
 	bdev = bdget_disk(block->gdp, 0);
-	if (!bdev || blkdev_get(bdev, FMODE_READ) < 0)
+	if (!bdev || blkdev_get(bdev, FMODE_READ, NULL) < 0)
 		return -ENODEV;
 	/*
 	 * See fs/partition/check.c:register_disk,rescan_partitions

drivers/usb/gadget/storage_common.c

···
 	ro = curlun->initially_ro;
 	if (!ro) {
 		filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
-		if (-EROFS == PTR_ERR(filp))
+		if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
 			ro = 1;
 	}
 	if (ro)
···
 
 	if (filp->f_path.dentry)
 		inode = filp->f_path.dentry->d_inode;
-	if (inode && S_ISBLK(inode->i_mode)) {
-		if (bdev_read_only(inode->i_bdev))
-			ro = 1;
-	} else if (!inode || !S_ISREG(inode->i_mode)) {
+	if (!inode || (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
 		LINFO(curlun, "invalid file type: %s\n", filename);
 		goto out;
 	}

fs/block_dev.c

···
 	mutex_init(&bdev->bd_mutex);
 	INIT_LIST_HEAD(&bdev->bd_inodes);
 	INIT_LIST_HEAD(&bdev->bd_list);
-#ifdef CONFIG_SYSFS
-	INIT_LIST_HEAD(&bdev->bd_holder_list);
-#endif
 	inode_init_once(&ei->vfs_inode);
 	/* Initialize mutex for freeze. */
 	mutex_init(&bdev->bd_fsfreeze_mutex);
···
 	else if (bdev->bd_contains == bdev)
 		return true;  	 /* is a whole device which isn't held */
 
-	else if (whole->bd_holder == bd_claim)
+	else if (whole->bd_holder == bd_may_claim)
 		return true; 	 /* is a partition of a device that is being partitioned */
 	else if (whole->bd_holder != NULL)
 		return false;	 /* is a partition of a held device */
···
 	}
 }
 
-/* releases bdev_lock */
-static void __bd_abort_claiming(struct block_device *whole, void *holder)
-{
-	BUG_ON(whole->bd_claiming != holder);
-	whole->bd_claiming = NULL;
-	wake_up_bit(&whole->bd_claiming, 0);
-
-	spin_unlock(&bdev_lock);
-	bdput(whole);
-}
-
-/**
- * bd_abort_claiming - abort claiming a block device
- * @whole: whole block device returned by bd_start_claiming()
- * @holder: holder trying to claim @bdev
- *
- * Abort a claiming block started by bd_start_claiming().  Note that
- * @whole is not the block device to be claimed but the whole device
- * returned by bd_start_claiming().
- *
- * CONTEXT:
- * Grabs and releases bdev_lock.
- */
-static void bd_abort_claiming(struct block_device *whole, void *holder)
-{
-	spin_lock(&bdev_lock);
-	__bd_abort_claiming(whole, holder);		/* releases bdev_lock */
-}
-
-/* increment holders when we have a legitimate claim. requires bdev_lock */
-static void __bd_claim(struct block_device *bdev, struct block_device *whole,
-					void *holder)
-{
-	/* note that for a whole device bd_holders
-	 * will be incremented twice, and bd_holder will
-	 * be set to bd_claim before being set to holder
-	 */
-	whole->bd_holders++;
-	whole->bd_holder = bd_claim;
-	bdev->bd_holders++;
-	bdev->bd_holder = holder;
-}
-
-/**
- * bd_finish_claiming - finish claiming a block device
- * @bdev: block device of interest (passed to bd_start_claiming())
- * @whole: whole block device returned by bd_start_claiming()
- * @holder: holder trying to claim @bdev
- *
- * Finish a claiming block started by bd_start_claiming().
- *
- * CONTEXT:
- * Grabs and releases bdev_lock.
- */
-static void bd_finish_claiming(struct block_device *bdev,
-				struct block_device *whole, void *holder)
-{
-	spin_lock(&bdev_lock);
-	BUG_ON(!bd_may_claim(bdev, whole, holder));
-	__bd_claim(bdev, whole, holder);
-	__bd_abort_claiming(whole, holder); /* not actually an abort */
-}
-
-/**
- * bd_claim - claim a block device
- * @bdev: block device to claim
- * @holder: holder trying to claim @bdev
- *
- * Try to claim @bdev which must have been opened successfully.
- *
- * CONTEXT:
- * Might sleep.
- *
- * RETURNS:
- * 0 if successful, -EBUSY if @bdev is already claimed.
- */
-int bd_claim(struct block_device *bdev, void *holder)
-{
-	struct block_device *whole = bdev->bd_contains;
-	int res;
-
-	might_sleep();
-
-	spin_lock(&bdev_lock);
-	res = bd_prepare_to_claim(bdev, whole, holder);
-	if (res == 0)
-		__bd_claim(bdev, whole, holder);
-	spin_unlock(&bdev_lock);
-
-	return res;
-}
-EXPORT_SYMBOL(bd_claim);
-
-void bd_release(struct block_device *bdev)
-{
-	spin_lock(&bdev_lock);
-	if (!--bdev->bd_contains->bd_holders)
-		bdev->bd_contains->bd_holder = NULL;
-	if (!--bdev->bd_holders)
-		bdev->bd_holder = NULL;
-	spin_unlock(&bdev_lock);
-}
-
-EXPORT_SYMBOL(bd_release);
-
 #ifdef CONFIG_SYSFS
-/*
- * Functions for bd_claim_by_kobject / bd_release_from_kobject
- *
- *     If a kobject is passed to bd_claim_by_kobject()
- *     and the kobject has a parent directory,
- *     following symlinks are created:
- *        o from the kobject to the claimed bdev
- *        o from "holders" directory of the bdev to the parent of the kobject
- *     bd_release_from_kobject() removes these symlinks.
- *
- *     Example:
- *        If /dev/dm-0 maps to /dev/sda, kobject corresponding to
- *        /sys/block/dm-0/slaves is passed to bd_claim_by_kobject(), then:
- *           /sys/block/dm-0/slaves/sda --> /sys/block/sda
- *           /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
- */
-
 static int add_symlink(struct kobject *from, struct kobject *to)
 {
-	if (!from || !to)
-		return 0;
 	return sysfs_create_link(from, to, kobject_name(to));
 }
 
 static void del_symlink(struct kobject *from, struct kobject *to)
 {
-	if (!from || !to)
-		return;
 	sysfs_remove_link(from, kobject_name(to));
 }
 
-/*
- * 'struct bd_holder' contains pointers to kobjects symlinked by
- * bd_claim_by_kobject.
- * It's connected to bd_holder_list which is protected by bdev->bd_sem.
- */
-struct bd_holder {
-	struct list_head list;	/* chain of holders of the bdev */
-	int count;		/* references from the holder */
-	struct kobject *sdir;	/* holder object, e.g. "/block/dm-0/slaves" */
-	struct kobject *hdev;	/* e.g. "/block/dm-0" */
-	struct kobject *hdir;	/* e.g. "/block/sda/holders" */
-	struct kobject *sdev;	/* e.g. "/block/sda" */
-};
-
-/*
- * Get references of related kobjects at once.
- * Returns 1 on success. 0 on failure.
- *
- * Should call bd_holder_release_dirs() after successful use.
- */
-static int bd_holder_grab_dirs(struct block_device *bdev,
-			struct bd_holder *bo)
-{
-	if (!bdev || !bo)
-		return 0;
-
-	bo->sdir = kobject_get(bo->sdir);
-	if (!bo->sdir)
-		return 0;
-
-	bo->hdev = kobject_get(bo->sdir->parent);
-	if (!bo->hdev)
-		goto fail_put_sdir;
-
-	bo->sdev = kobject_get(&part_to_dev(bdev->bd_part)->kobj);
-	if (!bo->sdev)
-		goto fail_put_hdev;
-
-	bo->hdir = kobject_get(bdev->bd_part->holder_dir);
-	if (!bo->hdir)
-		goto fail_put_sdev;
-
-	return 1;
-
-fail_put_sdev:
-	kobject_put(bo->sdev);
-fail_put_hdev:
-	kobject_put(bo->hdev);
-fail_put_sdir:
-	kobject_put(bo->sdir);
-
-	return 0;
-}
-
-/* Put references of related kobjects at once. */
-static void bd_holder_release_dirs(struct bd_holder *bo)
-{
-	kobject_put(bo->hdir);
-	kobject_put(bo->sdev);
-	kobject_put(bo->hdev);
-	kobject_put(bo->sdir);
-}
-
-static struct bd_holder *alloc_bd_holder(struct kobject *kobj)
-{
-	struct bd_holder *bo;
-
-	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
-	if (!bo)
-		return NULL;
-
-	bo->count = 1;
-	bo->sdir = kobj;
-
-	return bo;
-}
-
-static void free_bd_holder(struct bd_holder *bo)
-{
-	kfree(bo);
-}
-
 /**
- * find_bd_holder - find matching struct bd_holder from the block device
+ * bd_link_disk_holder - create symlinks between holding disk and slave bdev
+ * @bdev: the claimed slave bdev
+ * @disk: the holding disk
  *
- * @bdev:	struct block device to be searched
- * @bo:		target struct bd_holder
+ * This functions creates the following sysfs symlinks.
  *
- * Returns matching entry with @bo in @bdev->bd_holder_list.
- * If found, increment the reference count and return the pointer.
- * If not found, returns NULL.
+ * - from "slaves" directory of the holder @disk to the claimed @bdev
+ * - from "holders" directory of the @bdev to the holder @disk
+ *
+ * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is
+ * passed to bd_link_disk_holder(), then:
+ *
+ *   /sys/block/dm-0/slaves/sda --> /sys/block/sda
+ *   /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
+ *
+ * The caller must have claimed @bdev before calling this function and
+ * ensure that both @bdev and @disk are valid during the creation and
+ * lifetime of these symlinks.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
  */
-static struct bd_holder *find_bd_holder(struct block_device *bdev,
-					struct bd_holder *bo)
+int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
 {
-	struct bd_holder *tmp;
-
-	list_for_each_entry(tmp, &bdev->bd_holder_list, list)
-		if (tmp->sdir == bo->sdir) {
-			tmp->count++;
-			return tmp;
-		}
-
-	return NULL;
-}
-
-/**
- * add_bd_holder - create sysfs symlinks for bd_claim() relationship
- *
- * @bdev:	block device to be bd_claimed
- * @bo:		preallocated and initialized by alloc_bd_holder()
- *
- * Add @bo to @bdev->bd_holder_list, create symlinks.
- *
- * Returns 0 if symlinks are created.
- * Returns -ve if something fails.
- */
-static int add_bd_holder(struct block_device *bdev, struct bd_holder *bo)
-{
-	int err;
-
-	if (!bo)
-		return -EINVAL;
-
-	if (!bd_holder_grab_dirs(bdev, bo))
-		return -EBUSY;
-
-	err = add_symlink(bo->sdir, bo->sdev);
-	if (err)
-		return err;
-
-	err = add_symlink(bo->hdir, bo->hdev);
-	if (err) {
-		del_symlink(bo->sdir, bo->sdev);
-		return err;
-	}
-
-	list_add_tail(&bo->list, &bdev->bd_holder_list);
-	return 0;
-}
-
-/**
- * del_bd_holder - delete sysfs symlinks for bd_claim() relationship
- *
- * @bdev:	block device to be bd_claimed
- * @kobj:	holder's kobject
- *
- * If there is matching entry with @kobj in @bdev->bd_holder_list
- * and no other bd_claim() from the same kobject,
- * remove the struct bd_holder from the list, delete symlinks for it.
- *
- * Returns a pointer to the struct bd_holder when it's removed from the list
- * and ready to be freed.
- * Returns NULL if matching claim isn't found or there is other bd_claim()
- * by the same kobject.
- */
-static struct bd_holder *del_bd_holder(struct block_device *bdev,
-					struct kobject *kobj)
-{
-	struct bd_holder *bo;
-
-	list_for_each_entry(bo, &bdev->bd_holder_list, list) {
-		if (bo->sdir == kobj) {
-			bo->count--;
-			BUG_ON(bo->count < 0);
-			if (!bo->count) {
-				list_del(&bo->list);
-				del_symlink(bo->sdir, bo->sdev);
-				del_symlink(bo->hdir, bo->hdev);
-				bd_holder_release_dirs(bo);
-				return bo;
-			}
-			break;
-		}
-	}
-
-	return NULL;
-}
-
-/**
- * bd_claim_by_kobject - bd_claim() with additional kobject signature
- *
- * @bdev:	block device to be claimed
- * @holder:	holder's signature
- * @kobj:	holder's kobject
- *
- * Do bd_claim() and if it succeeds, create sysfs symlinks between
- * the bdev and the holder's kobject.
- * Use bd_release_from_kobject() when relesing the claimed bdev.
- *
- * Returns 0 on success. (same as bd_claim())
- * Returns errno on failure.
- */
-static int bd_claim_by_kobject(struct block_device *bdev, void *holder,
-				struct kobject *kobj)
-{
-	int err;
-	struct bd_holder *bo, *found;
-
-	if (!kobj)
-		return -EINVAL;
-
-	bo = alloc_bd_holder(kobj);
-	if (!bo)
-		return -ENOMEM;
+	int ret = 0;
 
 	mutex_lock(&bdev->bd_mutex);
 
-	err = bd_claim(bdev, holder);
-	if (err)
-		goto fail;
+	WARN_ON_ONCE(!bdev->bd_holder || bdev->bd_holder_disk);
 
-	found = find_bd_holder(bdev, bo);
-	if (found)
-		goto fail;
+	/* FIXME: remove the following once add_disk() handles errors */
+	if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir))
+		goto out_unlock;
 
-	err = add_bd_holder(bdev, bo);
-	if (err)
-		bd_release(bdev);
-	else
-		bo = NULL;
-fail:
+	ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+	if (ret)
+		goto out_unlock;
+
+	ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
+	if (ret) {
+		del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+		goto out_unlock;
+	}
+
+	bdev->bd_holder_disk = disk;
+out_unlock:
 	mutex_unlock(&bdev->bd_mutex);
-	free_bd_holder(bo);
-	return err;
+	return ret;
 }
+EXPORT_SYMBOL_GPL(bd_link_disk_holder);
 
-/**
- * bd_release_from_kobject - bd_release() with additional kobject signature
- *
- * @bdev:	block device to be released
- * @kobj:	holder's kobject
- *
- * Do bd_release() and remove sysfs symlinks created by bd_claim_by_kobject().
- */
-static void bd_release_from_kobject(struct block_device *bdev,
-					struct kobject *kobj)
+static void bd_unlink_disk_holder(struct block_device *bdev)
 {
-	if (!kobj)
+	struct gendisk *disk = bdev->bd_holder_disk;
+
+	bdev->bd_holder_disk = NULL;
+	if (!disk)
 		return;
 
-	mutex_lock(&bdev->bd_mutex);
-	bd_release(bdev);
-	free_bd_holder(del_bd_holder(bdev, kobj));
-	mutex_unlock(&bdev->bd_mutex);
+	del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+	del_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
 }
-
-/**
- * bd_claim_by_disk - wrapper function for bd_claim_by_kobject()
- *
- * @bdev:	block device to be claimed
- * @holder:	holder's signature
- * @disk:	holder's gendisk
- *
- * Call bd_claim_by_kobject() with getting @disk->slave_dir.
- */
-int bd_claim_by_disk(struct block_device *bdev, void *holder,
-			struct gendisk *disk)
-{
-	return bd_claim_by_kobject(bdev, holder, kobject_get(disk->slave_dir));
-}
-EXPORT_SYMBOL_GPL(bd_claim_by_disk);
-
-/**
- * bd_release_from_disk - wrapper function for bd_release_from_kobject()
- *
- * @bdev:	block device to be claimed
- * @disk:	holder's gendisk
- *
- * Call bd_release_from_kobject() and put @disk->slave_dir.
- */
-void bd_release_from_disk(struct block_device *bdev, struct gendisk *disk)
-{
-	bd_release_from_kobject(bdev, disk->slave_dir);
-	kobject_put(disk->slave_dir);
-}
-EXPORT_SYMBOL_GPL(bd_release_from_disk);
+#else
+static inline void bd_unlink_disk_holder(struct block_device *bdev)
+{ }
 #endif
-
-/*
- * Tries to open block device by device number.  Use it ONLY if you
- * really do not have anything better - i.e. when you are behind a
- * truly sucky interface and all you are given is a device number.  _Never_
- * to be used for internal purposes.  If you ever need it - reconsider
- * your API.
- */
-struct block_device *open_by_devnum(dev_t dev, fmode_t mode)
-{
-	struct block_device *bdev = bdget(dev);
-	int err = -ENOMEM;
-	if (bdev)
-		err = blkdev_get(bdev, mode);
-	return err ? ERR_PTR(err) : bdev;
-}
-
-EXPORT_SYMBOL(open_by_devnum);
 
 /**
  * flush_disk - invalidates all buffer-cache entries on a disk
···
 	return ret;
 }
 
-int blkdev_get(struct block_device *bdev, fmode_t mode)
+/**
+ * blkdev_get - open a block device
+ * @bdev: block_device to open
+ * @mode: FMODE_* mask
+ * @holder: exclusive holder identifier
+ *
+ * Open @bdev with @mode.  If @mode includes %FMODE_EXCL, @bdev is
+ * open with exclusive access.  Specifying %FMODE_EXCL with %NULL
+ * @holder is invalid.  Exclusive opens may nest for the same @holder.
+ *
+ * On success, the reference count of @bdev is unchanged.  On failure,
+ * @bdev is put.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
 {
-	return __blkdev_get(bdev, mode, 0);
+	struct block_device *whole = NULL;
+	int res;
+
+	WARN_ON_ONCE((mode & FMODE_EXCL) && !holder);
+
+	if ((mode & FMODE_EXCL) && holder) {
+		whole = bd_start_claiming(bdev, holder);
+		if (IS_ERR(whole)) {
+			bdput(bdev);
+			return PTR_ERR(whole);
+		}
+	}
+
+	res = __blkdev_get(bdev, mode, 0);
+
+	/* __blkdev_get() may alter read only status, check it afterwards */
+	if (!res && (mode & FMODE_WRITE) && bdev_read_only(bdev)) {
+		__blkdev_put(bdev, mode, 0);
+		res = -EACCES;
+	}
+
+	if (whole) {
+		/* finish claiming */
+		spin_lock(&bdev_lock);
+
+		if (res == 0) {
+			BUG_ON(!bd_may_claim(bdev, whole, holder));
+			/*
+			 * Note that for a whole device bd_holders
+			 * will be incremented twice, and bd_holder
+			 * will be set to bd_may_claim before being
+			 * set to holder
+			 */
+			whole->bd_holders++;
+			whole->bd_holder = bd_may_claim;
+			bdev->bd_holders++;
+			bdev->bd_holder = holder;
+		}
+
+		/* tell others that we're done */
+		BUG_ON(whole->bd_claiming != holder);
+		whole->bd_claiming = NULL;
+		wake_up_bit(&whole->bd_claiming, 0);
+
+		spin_unlock(&bdev_lock);
+		bdput(whole);
+	}
+
+	return res;
 }
 EXPORT_SYMBOL(blkdev_get);
 
+/**
+ * blkdev_get_by_path - open a block device by name
+ * @path: path to the block device to open
+ * @mode: FMODE_* mask
+ * @holder: exclusive holder identifier
+ *
+ * Open the blockdevice described by the device file at @path.  @mode
+ * and @holder are identical to blkdev_get().
+ *
+ * On success, the returned block_device has reference count of one.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * Pointer to block_device on success, ERR_PTR(-errno) on failure.
+ */
+struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
+					void *holder)
+{
+	struct block_device *bdev;
+	int err;
+
+	bdev = lookup_bdev(path);
+	if (IS_ERR(bdev))
+		return bdev;
+
+	err = blkdev_get(bdev, mode, holder);
+	if (err)
+		return ERR_PTR(err);
+
+	return bdev;
+}
+EXPORT_SYMBOL(blkdev_get_by_path);
+
+/**
+ * blkdev_get_by_dev - open a block device by device number
+ * @dev: device number of block device to open
+ * @mode: FMODE_* mask
+ * @holder: exclusive holder identifier
+ *
+ * Open the blockdevice described by device number @dev.  @mode and
+ * @holder are identical to blkdev_get().
+ *
+ * Use it ONLY if you really do not have anything better - i.e. when
+ * you are behind a truly sucky interface and all you are given is a
+ * device number.  _Never_ to be used for internal purposes.  If you
+ * ever need it - reconsider your API.
+ *
+ * On success, the returned block_device has reference count of one.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * Pointer to block_device on success, ERR_PTR(-errno) on failure.
+ */
+struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
+{
+	struct block_device *bdev;
+	int err;
+
+	bdev = bdget(dev);
+	if (!bdev)
+		return ERR_PTR(-ENOMEM);
+
+	err = blkdev_get(bdev, mode, holder);
+	if (err)
+		return ERR_PTR(err);
+
+	return bdev;
+}
+EXPORT_SYMBOL(blkdev_get_by_dev);
+
 static int blkdev_open(struct inode * inode, struct file * filp)
 {
-	struct block_device *whole = NULL;
 	struct block_device *bdev;
-	int res;
 
 	/*
 	 * Preserve backwards compatibility and allow large file access
···
 	if (bdev == NULL)
 		return -ENOMEM;
 
-	if (filp->f_mode & FMODE_EXCL) {
-		whole = bd_start_claiming(bdev, filp);
-		if (IS_ERR(whole)) {
-			bdput(bdev);
-			return PTR_ERR(whole);
-		}
-	}
-
 	filp->f_mapping = bdev->bd_inode->i_mapping;
 
-	res = blkdev_get(bdev, filp->f_mode);
-
-	if (whole) {
-		if (res == 0)
-			bd_finish_claiming(bdev, whole, filp);
-		else
-			bd_abort_claiming(whole, filp);
-	}
-
-	return res;
+	return blkdev_get(bdev, filp->f_mode, filp);
 }
 
 static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
···
 		bdev->bd_part_count--;
 
 	if (!--bdev->bd_openers) {
+		WARN_ON_ONCE(bdev->bd_holders);
 		sync_blockdev(bdev);
 		kill_bdev(bdev);
 	}
···
 
 int blkdev_put(struct block_device *bdev, fmode_t mode)
 {
+	if (mode & FMODE_EXCL) {
+		bool bdev_free;
+
+		/*
+		 * Release a claim on the device.  The holder fields
+		 * are protected with bdev_lock.  bd_mutex is to
+		 * synchronize disk_holder unlinking.
+		 */
+		mutex_lock(&bdev->bd_mutex);
+		spin_lock(&bdev_lock);
+
+		WARN_ON_ONCE(--bdev->bd_holders < 0);
+		WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0);
+
+		/* bd_contains might point to self, check in a separate step */
+		if ((bdev_free = !bdev->bd_holders))
+			bdev->bd_holder = NULL;
+		if (!bdev->bd_contains->bd_holders)
+			bdev->bd_contains->bd_holder = NULL;
+
+		spin_unlock(&bdev_lock);
+
+		/* if this was the last claim, holder link should go too */
+		if (bdev_free)
+			bd_unlink_disk_holder(bdev);
+
+		mutex_unlock(&bdev->bd_mutex);
+	}
 	return __blkdev_put(bdev, mode, 0);
 }
 EXPORT_SYMBOL(blkdev_put);
···
 static int blkdev_close(struct inode * inode, struct file * filp)
 {
 	struct block_device *bdev = I_BDEV(filp->f_mapping->host);
-	if (bdev->bd_holder == filp)
-		bd_release(bdev);
+
 	return blkdev_put(bdev, filp->f_mode);
 }
 
···
 	goto out;
 }
 EXPORT_SYMBOL(lookup_bdev);
-
-/**
- * open_bdev_exclusive  -  open a block device by name and set it up for use
- *
- * @path:	special file representing the block device
- * @mode:	FMODE_... combination to pass be used
- * @holder:	owner for exclusion
- *
- * Open the blockdevice described by the special file at @path, claim it
- * for the @holder.
- */
-struct block_device *open_bdev_exclusive(const char *path, fmode_t mode, void *holder)
-{
-	struct block_device *bdev, *whole;
-	int error;
-
-	bdev = lookup_bdev(path);
-	if (IS_ERR(bdev))
-		return bdev;
-
-	whole = bd_start_claiming(bdev, holder);
-	if (IS_ERR(whole)) {
-		bdput(bdev);
-		return whole;
-	}
-
-	error = blkdev_get(bdev, mode);
-	if (error)
-		goto out_abort_claiming;
-
-	error = -EACCES;
-	if ((mode & FMODE_WRITE) && bdev_read_only(bdev))
-		goto out_blkdev_put;
-
-	bd_finish_claiming(bdev, whole, holder);
-	return bdev;
-
-out_blkdev_put:
-	blkdev_put(bdev, mode);
-out_abort_claiming:
-	bd_abort_claiming(whole, holder);
-	return ERR_PTR(error);
-}
-
-EXPORT_SYMBOL(open_bdev_exclusive);
-
-/**
- * close_bdev_exclusive  -  close a blockdevice opened by open_bdev_exclusive()
- *
- * @bdev:	blockdevice to close
- * @mode:	mode, must match that used to open.
- *
- * This is the counterpart to open_bdev_exclusive().
- */
-void close_bdev_exclusive(struct block_device *bdev, fmode_t mode)
-{
-	bd_release(bdev);
-	blkdev_put(bdev, mode);
-}
-
-EXPORT_SYMBOL(close_bdev_exclusive);
 
 int __invalidate_device(struct block_device *bdev)
 {

fs/btrfs/volumes.c

···
 			continue;
 
 		if (device->bdev) {
-			close_bdev_exclusive(device->bdev, device->mode);
+			blkdev_put(device->bdev, device->mode);
 			device->bdev = NULL;
 			fs_devices->open_devices--;
 		}
···
 
 	list_for_each_entry(device, &fs_devices->devices, dev_list) {
 		if (device->bdev) {
-			close_bdev_exclusive(device->bdev, device->mode);
+			blkdev_put(device->bdev, device->mode);
 			fs_devices->open_devices--;
 		}
 		if (device->writeable) {
···
 	int seeding = 1;
 	int ret = 0;
 
+	flags |= FMODE_EXCL;
+
 	list_for_each_entry(device, head, dev_list) {
 		if (device->bdev)
 			continue;
 		if (!device->name)
 			continue;
 
-		bdev = open_bdev_exclusive(device->name, flags, holder);
+		bdev = blkdev_get_by_path(device->name, flags, holder);
 		if (IS_ERR(bdev)) {
 			printk(KERN_INFO "open %s failed\n", device->name);
 			goto error;
···
 error_brelse:
 		brelse(bh);
 error_close:
-		close_bdev_exclusive(bdev, FMODE_READ);
+		blkdev_put(bdev, flags);
 error:
 		continue;
 	}
···
 
 	mutex_lock(&uuid_mutex);
 
-	bdev = open_bdev_exclusive(path, flags, holder);
+	flags |= FMODE_EXCL;
+	bdev = blkdev_get_by_path(path, flags, holder);
 
 	if (IS_ERR(bdev)) {
 		ret = PTR_ERR(bdev);
···
 
 	brelse(bh);
 error_close:
-	close_bdev_exclusive(bdev, flags);
+	blkdev_put(bdev, flags);
 error:
 	mutex_unlock(&uuid_mutex);
 	return ret;
···
 			goto out;
 		}
 	} else {
-		bdev = open_bdev_exclusive(device_path, FMODE_READ,
-				      root->fs_info->bdev_holder);
+		bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
+					  root->fs_info->bdev_holder);
 		if (IS_ERR(bdev)) {
 			ret = PTR_ERR(bdev);
 			goto out;
···
 		root->fs_info->fs_devices->latest_bdev = next_device->bdev;
 
 	if (device->bdev) {
-		close_bdev_exclusive(device->bdev, device->mode);
+		blkdev_put(device->bdev, device->mode);
 		device->bdev = NULL;
 		device->fs_devices->open_devices--;
 	}
···
 	brelse(bh);
 error_close:
 	if (bdev)
-		close_bdev_exclusive(bdev, FMODE_READ);
+		blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
 out:
 	mutex_unlock(&root->fs_info->volume_mutex);
 	mutex_unlock(&uuid_mutex);
···
 	if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
 		return -EINVAL;
 
-	bdev = open_bdev_exclusive(device_path, 0, root->fs_info->bdev_holder);
+	bdev = blkdev_get_by_path(device_path, FMODE_EXCL,
+				  root->fs_info->bdev_holder);
 	if (IS_ERR(bdev))
 		return PTR_ERR(bdev);
 
···
 	mutex_unlock(&root->fs_info->volume_mutex);
 	return ret;
 error:
-	close_bdev_exclusive(bdev, 0);
+	blkdev_put(bdev, FMODE_EXCL);
 	if (seeding_dev) {
 		mutex_unlock(&uuid_mutex);
 		up_write(&sb->s_umount);

fs/btrfs/volumes.h

···
 
 	struct block_device *bdev;
 
-	/* the mode sent to open_bdev_exclusive */
+	/* the mode sent to blkdev_get */
 	fmode_t mode;
 
 	char *name;

fs/ext3/super.c

···
 	struct block_device *bdev;
 	char b[BDEVNAME_SIZE];
 
-	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
+	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 	if (IS_ERR(bdev))
 		goto fail;
 	return bdev;
···
  */
 static int ext3_blkdev_put(struct block_device *bdev)
 {
-	bd_release(bdev);
-	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
+	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 }
 
 static int ext3_blkdev_remove(struct ext3_sb_info *sbi)
···
 	bdev = ext3_blkdev_get(j_dev, sb);
 	if (bdev == NULL)
 		return NULL;
-
-	if (bd_claim(bdev, sb)) {
-		ext3_msg(sb, KERN_ERR,
-			"error: failed to claim external journal device");
-		blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
-		return NULL;
-	}
 
 	blocksize = sb->s_blocksize;
 	hblock = bdev_logical_block_size(bdev);

fs/ext4/super.c

···
 	struct block_device *bdev;
 	char b[BDEVNAME_SIZE];
 
-	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
+	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 	if (IS_ERR(bdev))
 		goto fail;
 	return bdev;
···
  */
 static int ext4_blkdev_put(struct block_device *bdev)
 {
-	bd_release(bdev);
-	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
+	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 }
 
 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
···
 	bdev = ext4_blkdev_get(j_dev, sb);
 	if (bdev == NULL)
 		return NULL;
-
-	if (bd_claim(bdev, sb)) {
-		ext4_msg(sb, KERN_ERR,
-			"failed to claim external journal device");
-		blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
-		return NULL;
-	}
 
 	blocksize = sb->s_blocksize;
 	hblock = bdev_logical_block_size(bdev);

fs/gfs2/ops_fstype.c

···
 {
 	struct block_device *bdev;
 	struct super_block *s;
-	fmode_t mode = FMODE_READ;
+	fmode_t mode = FMODE_READ | FMODE_EXCL;
 	int error;
 	struct gfs2_args args;
 	struct gfs2_sbd *sdp;
···
 	if (!(flags & MS_RDONLY))
 		mode |= FMODE_WRITE;
 
-	bdev = open_bdev_exclusive(dev_name, mode, fs_type);
+	bdev = blkdev_get_by_path(dev_name, mode, fs_type);
 	if (IS_ERR(bdev))
 		return ERR_CAST(bdev);
 
···
 		goto error_bdev;
 
 	if (s->s_root)
-		close_bdev_exclusive(bdev, mode);
+		blkdev_put(bdev, mode);
 
 	memset(&args, 0, sizeof(args));
 	args.ar_quota = GFS2_QUOTA_DEFAULT;
···
 	deactivate_locked_super(s);
 	return ERR_PTR(error);
 error_bdev:
-	close_bdev_exclusive(bdev, mode);
+	blkdev_put(bdev, mode);
 	return ERR_PTR(error);
 }
 

fs/jfs/jfs_logmgr.c

···
 	 * file systems to log may have n-to-1 relationship;
 	 */
 
-	bdev = open_by_devnum(sbi->logdev, FMODE_READ|FMODE_WRITE);
+	bdev = blkdev_get_by_dev(sbi->logdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
+				 log);
 	if (IS_ERR(bdev)) {
 		rc = -PTR_ERR(bdev);
 		goto free;
-	}
-
-	if ((rc = bd_claim(bdev, log))) {
-		goto close;
 	}
 
 	log->bdev = bdev;
···
 	 * initialize log:
 	 */
 	if ((rc = lmLogInit(log)))
-		goto unclaim;
+		goto close;
 
 	list_add(&log->journal_list, &jfs_external_logs);
 
···
 	list_del(&log->journal_list);
 	lbmLogShutdown(log);
 
-      unclaim:
-	bd_release(bdev);
-
       close:		/* close external log device */
-	blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
+	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 
       free:		/* free log descriptor */
 	mutex_unlock(&jfs_log_mutex);
···
 	bdev = log->bdev;
 	rc = lmLogShutdown(log);
 
-	bd_release(bdev);
-	blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
+	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 
 	kfree(log);
 

fs/logfs/dev_bdev.c

···
 
 static void bdev_put_device(struct logfs_super *s)
 {
-	close_bdev_exclusive(s->s_bdev, FMODE_READ|FMODE_WRITE);
+	blkdev_put(s->s_bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 }
 
 static int bdev_can_write_buf(struct super_block *sb, u64 ofs)
···
 {
 	struct block_device *bdev;
 
-	bdev = open_bdev_exclusive(devname, FMODE_READ|FMODE_WRITE, type);
+	bdev = blkdev_get_by_path(devname, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
+				  type);
 	if (IS_ERR(bdev))
 		return PTR_ERR(bdev);
 
 	if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
 		int mtdnr = MINOR(bdev->bd_dev);
-		close_bdev_exclusive(bdev, FMODE_READ|FMODE_WRITE);
+		blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 		return logfs_get_sb_mtd(p, mtdnr);
 	}
 

fs/nilfs2/super.c

···
 {
 	struct nilfs_super_data sd;
 	struct super_block *s;
-	fmode_t mode = FMODE_READ;
+	fmode_t mode = FMODE_READ | FMODE_EXCL;
 	struct dentry *root_dentry;
 	int err, s_new = false;
 
 	if (!(flags & MS_RDONLY))
 		mode |= FMODE_WRITE;
 
-	sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
+	sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type);
 	if (IS_ERR(sd.bdev))
 		return ERR_CAST(sd.bdev);
 
···
 	}
 
 	if (!s_new)
-		close_bdev_exclusive(sd.bdev, mode);
+		blkdev_put(sd.bdev, mode);
 
 	return root_dentry;
 
···
 
  failed:
 	if (!s_new)
-		close_bdev_exclusive(sd.bdev, mode);
+		blkdev_put(sd.bdev, mode);
 	return ERR_PTR(err);
 }
 

fs/ocfs2/cluster/heartbeat.c

···
 		goto out;
 
 	reg->hr_bdev = I_BDEV(filp->f_mapping->host);
-	ret = blkdev_get(reg->hr_bdev, FMODE_WRITE | FMODE_READ);
+	ret = blkdev_get(reg->hr_bdev, FMODE_WRITE | FMODE_READ, NULL);
 	if (ret) {
 		reg->hr_bdev = NULL;
 		goto out;

fs/partitions/check.c

···
 		goto exit;
 
 	bdev->bd_invalidated = 1;
-	err = blkdev_get(bdev, FMODE_READ);
+	err = blkdev_get(bdev, FMODE_READ, NULL);
 	if (err < 0)
 		goto exit;
 	blkdev_put(bdev, FMODE_READ);

fs/reiserfs/journal.c

···
 	result = 0;
 
 	if (journal->j_dev_bd != NULL) {
-		if (journal->j_dev_bd->bd_dev != super->s_dev)
-			bd_release(journal->j_dev_bd);
 		result = blkdev_put(journal->j_dev_bd, journal->j_dev_mode);
 		journal->j_dev_bd = NULL;
 	}
···
 {
 	int result;
 	dev_t jdev;
-	fmode_t blkdev_mode = FMODE_READ | FMODE_WRITE;
+	fmode_t blkdev_mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
 	char b[BDEVNAME_SIZE];
 
 	result = 0;
···
 
 	/* there is no "jdev" option and journal is on separate device */
 	if ((!jdev_name || !jdev_name[0])) {
-		journal->j_dev_bd = open_by_devnum(jdev, blkdev_mode);
+		if (jdev == super->s_dev)
+			blkdev_mode &= ~FMODE_EXCL;
+		journal->j_dev_bd = blkdev_get_by_dev(jdev, blkdev_mode,
+						      journal);
 		journal->j_dev_mode = blkdev_mode;
 		if (IS_ERR(journal->j_dev_bd)) {
 			result = PTR_ERR(journal->j_dev_bd);
···
 					 "cannot init journal device '%s': %i",
 					 __bdevname(jdev, b), result);
 			return result;
-		} else if (jdev != super->s_dev) {
-			result = bd_claim(journal->j_dev_bd, journal);
-			if (result) {
-				blkdev_put(journal->j_dev_bd, blkdev_mode);
-				return result;
-			}
-
+		} else if (jdev != super->s_dev)
 			set_blocksize(journal->j_dev_bd, super->s_blocksize);
-		}
 
 		return 0;
 	}
 
 	journal->j_dev_mode = blkdev_mode;
-	journal->j_dev_bd = open_bdev_exclusive(jdev_name,
-						blkdev_mode, journal);
+	journal->j_dev_bd = blkdev_get_by_path(jdev_name, blkdev_mode, journal);
 	if (IS_ERR(journal->j_dev_bd)) {
 		result = PTR_ERR(journal->j_dev_bd);
 		journal->j_dev_bd = NULL;

fs/super.c

···
 {
 	struct block_device *bdev;
 	struct super_block *s;
-	fmode_t mode = FMODE_READ;
+	fmode_t mode = FMODE_READ | FMODE_EXCL;
 	int error = 0;
 
 	if (!(flags & MS_RDONLY))
 		mode |= FMODE_WRITE;
 
-	bdev = open_bdev_exclusive(dev_name, mode, fs_type);
+	bdev = blkdev_get_by_path(dev_name, mode, fs_type);
 	if (IS_ERR(bdev))
 		return ERR_CAST(bdev);
 
···
 
 		/*
 		 * s_umount nests inside bd_mutex during
-		 * __invalidate_device().  close_bdev_exclusive()
-		 * acquires bd_mutex and can't be called under
-		 * s_umount.  Drop s_umount temporarily.  This is safe
-		 * as we're holding an active reference.
+		 * __invalidate_device().  blkdev_put() acquires
+		 * bd_mutex and can't be called under s_umount.  Drop
+		 * s_umount temporarily.  This is safe as we're
+		 * holding an active reference.
 		 */
 		up_write(&s->s_umount);
-		close_bdev_exclusive(bdev, mode);
+		blkdev_put(bdev, mode);
 		down_write(&s->s_umount);
 	} else {
 		char b[BDEVNAME_SIZE];
···
 error_s:
 	error = PTR_ERR(s);
 error_bdev:
-	close_bdev_exclusive(bdev, mode);
+	blkdev_put(bdev, mode);
 error:
 	return ERR_PTR(error);
 }
···
 	bdev->bd_super = NULL;
 	generic_shutdown_super(sb);
 	sync_blockdev(bdev);
-	close_bdev_exclusive(bdev, mode);
+	WARN_ON_ONCE(!(mode & FMODE_EXCL));
+	blkdev_put(bdev, mode | FMODE_EXCL);
 }
 
 EXPORT_SYMBOL(kill_block_super);

fs/xfs/linux-2.6/xfs_super.c

···
 {
 	int			error = 0;
 
-	*bdevp = open_bdev_exclusive(name, FMODE_READ|FMODE_WRITE, mp);
+	*bdevp = blkdev_get_by_path(name, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
+				    mp);
 	if (IS_ERR(*bdevp)) {
 		error = PTR_ERR(*bdevp);
 		printk("XFS: Invalid device [%s], error=%d\n", name, error);
···
 	struct block_device	*bdev)
 {
 	if (bdev)
-		close_bdev_exclusive(bdev, FMODE_READ|FMODE_WRITE);
+		blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 }
 
 /*

include/linux/fs.h

···
 	void *			bd_holder;
 	int			bd_holders;
 #ifdef CONFIG_SYSFS
-	struct list_head	bd_holder_list;
+	struct gendisk *	bd_holder_disk;	/* for sysfs slave linkng */
 #endif
 	struct block_device *	bd_contains;
 	unsigned		bd_block_size;
···
 extern void bd_set_size(struct block_device *, loff_t size);
 extern void bd_forget(struct inode *inode);
 extern void bdput(struct block_device *);
-extern struct block_device *open_by_devnum(dev_t, fmode_t);
 extern void invalidate_bdev(struct block_device *);
 extern int sync_blockdev(struct block_device *bdev);
 extern struct super_block *freeze_bdev(struct block_device *);
···
 extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
 extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
 extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
-extern int blkdev_get(struct block_device *, fmode_t);
-extern int blkdev_put(struct block_device *, fmode_t);
-extern int bd_claim(struct block_device *, void *);
-extern void bd_release(struct block_device *);
+extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
+extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
+					       void *holder);
+extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,
+					      void *holder);
+extern int blkdev_put(struct block_device *bdev, fmode_t mode);
 #ifdef CONFIG_SYSFS
-extern int bd_claim_by_disk(struct block_device *, void *, struct gendisk *);
-extern void bd_release_from_disk(struct block_device *, struct gendisk *);
+extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
 #else
-#define bd_claim_by_disk(bdev, holder, disk)	bd_claim(bdev, holder)
-#define bd_release_from_disk(bdev, disk)	bd_release(bdev)
+static inline int bd_link_disk_holder(struct block_device *bdev,
+				      struct gendisk *disk)
+{
+	return 0;
+}
 #endif
 #endif
 
···
 extern const char *__bdevname(dev_t, char *buffer);
 extern const char *bdevname(struct block_device *bdev, char *buffer);
 extern struct block_device *lookup_bdev(const char *);
-extern struct block_device *open_bdev_exclusive(const char *, fmode_t, void *);
-extern void close_bdev_exclusive(struct block_device *, fmode_t);
 extern void blkdev_show(struct seq_file *,off_t);
 
 #else

kernel/power/swap.c

···
 		return res;
 
 	root_swap = res;
-	res = blkdev_get(hib_resume_bdev, FMODE_WRITE);
+	res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
 	if (res)
 		return res;
 
···
 {
 	int error;
 
-	hib_resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
+	hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
+					    FMODE_READ, NULL);
 	if (!IS_ERR(hib_resume_bdev)) {
 		set_blocksize(hib_resume_bdev, PAGE_SIZE);
 		clear_page(swsusp_header);

mm/swapfile.c

···
 	if (S_ISBLK(inode->i_mode)) {
 		struct block_device *bdev = I_BDEV(inode);
 		set_blocksize(bdev, p->old_block_size);
-		bd_release(bdev);
+		blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
 	} else {
 		mutex_lock(&inode->i_mutex);
 		inode->i_flags &= ~S_SWAPFILE;
···
 	error = -EINVAL;
 	if (S_ISBLK(inode->i_mode)) {
 		bdev = I_BDEV(inode);
-		error = bd_claim(bdev, sys_swapon);
+		error = blkdev_get(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL,
+				   sys_swapon);
 		if (error < 0) {
 			bdev = NULL;
 			error = -EINVAL;
···
 bad_swap:
 	if (bdev) {
 		set_blocksize(bdev, p->old_block_size);
-		bd_release(bdev);
+		blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
 	}
 	destroy_swap_extents(p);
 	swap_cgroup_swapoff(type);