From: Omar Sandoval Date: Mon, 18 May 2015 09:16:27 +0000 (-0700) Subject: Btrfs: remove all subvol options before mounting top-level X-Git-Tag: omap-for-v4.2/fixes-rc1^2~69^2~42 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e6e4dbe894ef29bd4aa05a7702e0cded1943dd10;p=pandora-kernel.git Btrfs: remove all subvol options before mounting top-level Currently, setup_root_args() substitutes 's/subvol=[^,]*/subvolid=0/'. But, this means that if the user passes both a subvol and subvolid for some reason, we won't actually mount the top-level when we recursively mount. For example, consider: mkfs.btrfs -f /dev/sdb mount /dev/sdb /mnt btrfs subvol create /mnt/subvol1 # subvolid=257 btrfs subvol create /mnt/subvol2 # subvolid=258 umount /mnt mount -osubvol=/subvol1,subvolid=258 /dev/sdb /mnt In the final mount, subvol=/subvol1,subvolid=258 becomes subvolid=0,subvolid=258, and the last option takes precedence, so we mount subvol2 and try to look up subvol1 inside of it, which fails. So, instead, do a thorough scan through the argument list and remove any subvol= and subvolid= options, then append subvolid=0 to the end. This implicitly makes subvol= take precedence over subvolid=, but we're about to add a stricter check for that. This also makes setup_root_args() more generic, which we'll need soon. Reviewed-by: David Sterba Signed-off-by: Omar Sandoval Signed-off-by: Chris Mason --- Reading git-diff-tree failed