> So. This time, while the backup was in process, I mounted /home
> read-only to check something out. Apparently that's not good enough to
> keep the filesystem intact,
Indeed, with ext4 (and maybe other journaled filesystems as well), even
if you mount read-only the system starts by (re)playing the end of the
journal to make sure the filesystem is in a consistent state.
> because at the end when I resumed, several
> things in $HOME didn't work right.
So apparently the resumed system then went on to "unconsistentify" the
file system somehow, due to it not knowing that the journal had been
(re)played behind its back. I don't know enough of the details to know
why that happens (playing the journal is conceptually something that
should be idempotent, but obviously things are more subtle than that).
> So what can I do to fix this, while still keeping my history, cookies,
> tabs, etc?
I'd start by unmounting the file system (might require a reboot) and
forcing an `fsck`. After that, you might want to compare the files
between your fsck'd partition and its backup. The sooner you do it,
the fewer changes there are, so the easier it will be to spot the
relevant (i.e. undesired) changes.
Stefan
