We forget to increase device_available if there's an error in snapshot_open(),
so the snapshot device cannot be open at all after snapshot_open() has
returned an error.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
        if (!atomic_add_unless(&device_available, -1, 0))
                return -EBUSY;
 
-       if ((filp->f_flags & O_ACCMODE) == O_RDWR)
+       if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
+               atomic_inc(&device_available);
                return -ENOSYS;
-
-       if(create_basic_memory_bitmaps())
+       }
+       if(create_basic_memory_bitmaps()) {
+               atomic_inc(&device_available);
                return -ENOMEM;
-
+       }
        nonseekable_open(inode, filp);
        data = &snapshot_state;
        filp->private_data = data;