block: clean up blkdev_get() wrappers and their users

After recent blkdev_get() modifications, open_by_devnum() and
open_bdev_exclusive() are simple wrappers around blkdev_get().
Replace them with blkdev_get_by_dev() and blkdev_get_by_path().

blkdev_get_by_dev() is identical to open_by_devnum().
blkdev_get_by_path() is slightly different in that it doesn't
automatically add %FMODE_EXCL to @mode.

All users are converted.  Most conversions are mechanical and don't
introduce any behavior difference.  There are several exceptions.

* btrfs now sets FMODE_EXCL in btrfs_device->mode, so there's no
  reason to OR it explicitly on blkdev_put().

* gfs2, nilfs2 and the generic mount_bdev() now set FMODE_EXCL in
  sb->s_mode.

* With the above changes, sb->s_mode now always should contain
  FMODE_EXCL.  WARN_ON_ONCE() added to kill_block_super() to detect
  errors.

The new blkdev_get_*() functions are with proper docbook comments.
While at it, add function description to blkdev_get() too.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Joern Engel <joern@lazybastard.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: reiserfs-devel@vger.kernel.org
Cc: xfs-masters@oss.sgi.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>

4 files changed, 11 insertions, 11 deletions

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index fd0346090289..650e43ba4f7c 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -902,8 +902,8 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
 		}
 	}
 
-	bdev = open_bdev_exclusive(nbc->dc.backing_dev,
-				   FMODE_READ | FMODE_WRITE, mdev);
+	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(bdev));
@@ -920,10 +920,10 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
 	 * should check it for you already; but if you don't, or
 	 * someone fooled it, we need to double check here)
 	 */
-	bdev = open_bdev_exclusive(nbc->dc.meta_dev,
-				   FMODE_READ | FMODE_WRITE,
-				   (nbc->dc.meta_dev_idx < 0) ?
-				   (void *)mdev : (void *)drbd_m_holder);
+	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(bdev));
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 9e88ca0c55e9..67150c32986c 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -325,7 +325,7 @@ static int open_dev(struct dm_dev_internal *d, dev_t dev,
 
 	BUG_ON(d->dm_dev.bdev);
 
-	bdev = open_by_devnum(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
+	bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
 	if (IS_ERR(bdev))
 		return PTR_ERR(bdev);
 
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 6af951ffe0bb..5aaa6bfbe638 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1934,8 +1934,8 @@ static int lock_rdev(mdk_rdev_t *rdev, dev_t dev, int shared)
 	struct block_device *bdev;
 	char b[BDEVNAME_SIZE];
 
-	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
-			      shared ? (mdk_rdev_t *)lock_rdev : rdev);
+	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));
diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index aa557beb8f51..f29a6f9df6e7 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -247,7 +247,7 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size)
 		return NULL;
 
 	/* Get a handle on the device */
-	bdev = open_bdev_exclusive(devname, mode, dev);
+	bdev = blkdev_get_by_path(devname, mode, dev);
 #ifndef MODULE
 	if (IS_ERR(bdev)) {
 
@@ -256,7 +256,7 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size)
 
 		dev_t devt = name_to_dev_t(devname);
 		if (devt)
-			bdev = open_by_devnum(devt, mode, dev);
+			bdev = blkdev_get_by_dev(devt, mode, dev);
 	}
 #endif