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block: clean up blkdev_get() wrappers and their users

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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>
This commit is contained in:
Tejun Heo
2010-11-13 11:55:18 +01:00
parent 75f1dc0d07
commit d4d7762995
18 changed files with 149 additions and 94 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
fs/super.c
View File

@@ -766,13 +766,13 @@ struct dentry *mount_bdev(struct file_system_type *fs_type,
{
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);
@@ -807,7 +807,7 @@ struct dentry *mount_bdev(struct file_system_type *fs_type,
* holding an active reference.
*/
up_write(&s->s_umount);
blkdev_put(bdev, mode | FMODE_EXCL);
blkdev_put(bdev, mode);
down_write(&s->s_umount);
} else {
char b[BDEVNAME_SIZE];
@@ -831,7 +831,7 @@ struct dentry *mount_bdev(struct file_system_type *fs_type,
error_s:
error = PTR_ERR(s);
error_bdev:
blkdev_put(bdev, mode | FMODE_EXCL);
blkdev_put(bdev, mode);
error:
return ERR_PTR(error);
}
@@ -862,6 +862,7 @@ void kill_block_super(struct super_block *sb)
bdev->bd_super = NULL;
generic_shutdown_super(sb);
sync_blockdev(bdev);
WARN_ON_ONCE(!(mode & FMODE_EXCL));
blkdev_put(bdev, mode | FMODE_EXCL);
}