After a lot of deep digging into the bind mount, loop driver, and buffer cache and tracking the corrupt pages back down the layers of the stack we've sanity checked this down to the image. The smoking gun was the kernel message:
Nov 6 12:15:16 ubuntu-phablet kernel: [ 3.940485] do_mount: /dev/loop0 -> /root [<null>] Nov 6 12:15:16 ubuntu-phablet kernel: [ 3.941095] EXT2-fs (loop0): warning: mounting unchecked fs, running e2fsck is recommended Nov 6 12:15:16 ubuntu-phablet kernel: [ 3.941431] do_mount return -> 0 (apologies for my extra debug). So it appears that /dev/loop0 is being mounted and it is corrupted. I ran fsck on /userdata/system.img and /userdata/ubuntu.img only to find that the system.img needed some fixing: fsck /userdata/system.img fsck from util-linux 2.25 e2fsck 1.42.10 (18-May-2014) /userdata/system.img was not cleanly unmounted, check forced. Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 3A: Optimizing directories Pass 4: Checking reference counts Unattached inode 3225 Connect to /lost+found<y>? yes Inode 3225 ref count is 2, should be 1. Fix<y>? yes Unattached inode 3709 Connect to /lost+found<y>? yes Inode 3709 ref count is 2, should be 1. Fix<y>? yes Unattached inode 3808 Connect to /lost+found<y>? yes Inode 3808 ref count is 2, should be 1. Fix<y>? yes Unattached inode 4427 Connect to /lost+found<y>? yes Inode 4427 ref count is 2, should be 1. Fix<y>? yes Unattached inode 4485 Connect to /lost+found<y>? yes Inode 4485 ref count is 2, should be 1. Fix<y>? yes Unattached inode 5889 Connect to /lost+found<y>? yes Inode 5889 ref count is 2, should be 1. Fix<y>? yes Unattached inode 5943 Connect to /lost+found<y>? yes Inode 5943 ref count is 2, should be 1. Fix<y>? yes Unattached inode 7853 Connect to /lost+found<y>? yes Inode 7853 ref count is 2, should be 1. Fix<y>? yes yyyPass 5: Checking group summary information Block bitmap differences: -70903 -71144 -71201 -(71674--71675) -71727 -71852 -72689 -72757 -(74519--74520) -74869 -74961 +(92082--92087) +(92089--92092) -92102 +92104 +92114 +y92119 +(92121--92131) Fix<y>? yes Free blocks count wrong for group #13 (8813, counted=8820). Fix<y>? yes Free blocks count wrong (133222, counted=133229). Fix<y>? yes Inode bitmap differences: +(19989--20010) +(20013--20014) -(20545--20549)y -(20551--20569) Fix<y>? yes Free inodes count wrong for group #13 (3225, counted=3232). Fix<y>? yes Directories count wrong for group #13 (761, counted=760). Fix<y>? yes Free inodes count wrong (81946, counted=81953). Fix<y>? yes /userdata/system.img: ***** FILE SYSTEM WAS MODIFIED ***** /userdata/system.img: ***** REBOOT LINUX ***** So, there are two big issues outstanding, most probably in the user space shutdown and initrd stages: 1. The file system is not being flushed and unmounted properly. 2. The file system is not being fsck'd before mounting - this is a cardinal sin IMHO The end result is mounting a corrupt file system that is causing the garbage in the apparmor files. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1387214 Title: file corruption on touch images in rw portions of the filesystem To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1387214/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
