Comment 5 for bug 438379

attaching full dmesg log containing the journal error:

[12044.533766] JBD2: Detected IO errors while flushing file data on sdb1:8
[12044.533801] Aborting journal on device sdb1:8.
[12044.536197] EXT4-fs error (device sdb1): ext4_journal_start_sb: Detected aborted journal
[12044.536207] EXT4-fs (sdb1): Remounting filesystem read-only
[12044.753276] journal commit I/O error
[12044.754345] sd 5:0:0:0: [sdb] Assuming drive cache: write through

performing a fsck gives the following (varying, but always the same kind of message, sometimes it even asks y/n):

fsck from util-linux-ng 2.16
e2fsck 1.41.9 (22-Aug-2009)
/dev/sdb1: recovering journal
Clearing orphaned inode 88661 (uid=500, gid=1000, mode=0140755, size=0)
/dev/sdb1: clean, 130365/484800 files, 1018223/1938616 blocks

trying to remount rw gives the following

sudo mount -o remount,rw -t ext4 /dev/sdb1 /
mount: cannot remount block device /dev/sdb1 read-write, is write-protected

the error occurs in about 40% of the resume cases and sometimes even after a cold boot.
I will install a mainline kernel as you suggested and see if it still occurs, but maybe you already have some ideas what it can be?

As said before: root is on /dev/sdb1, a built-in, but USB-attached SD-card-reader. I don't have a spare hard disk at hand to test, if this might be the problem.