Btrfs can span multiple devices, so sb->s_bdev will not always point to the block device that we are looking to freeze. This isn't a huge issue since the only thing that freezes per-bdev is device-mapper, but if btrfs spans multiple dm devices then we could run into corruption issues as we could end up not actually freezing the super properly. So enter contains_bdev. This will be used by get_active_super, if the sb implements contains_bdev we just ask the fs if it has the bdev we want and if so we are good to go. I'm not married to the name, so if anybody has any better suggestions I'm open to them. Comments? Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
