On Wed, May 05 2010 at 1:18am -0400, Douglas McClendon <dmc.fedora@xxxxxxxxxxxxxxxxxxxxxx> wrote: > Ok, so my complaining about code-progress should now be complete. I > think I'm back in action. But the "BUG: lock held when returning to > user space" still seems like a message you folks wanted yourselves > to hear. > > After grumbling to myself that fedora doesn't provide a package with > dmsetup.static, I went ahead and copied all relocatable deps > (/lib/ld-linux.so.2??) to tmpfs along with dmsetup, using > LD_LIBRARY_PATH. I also used --noudevrules and --noudevsync. Then > I followed the documentation I found which, for use cases as > esoteric as mine, might be desirable in snapshot.txt > > https://patchwork.kernel.org/patch/59806/ > > I.e. rules for snapshot handover in the general case. (who knows, > maybe I'll be the only user of non-snapshot-merge snapshot handover > for all time) (though technically I guess you can call what I've > been doing for the last several years to be an alternate form of > snapshot merging. I.e. where your snapshot base is readonly and you > are merging both the readonly base and cow to a third writable > device) > > Anyway, I finally got my stuffs working again, or at least, I have a > virtual snapshot-as-rootfs being dm-mirror migrated right now. I > assume that my loading of a new table, is sufficiently equivalent to > the dmsetup remove of the old snapshot as described in the above > link. Glad to hear snapshot cow handover is working well for you. > But finally, and the real reason for this message- during this I > noticed that the aforementioned "BUG:" was not in fact what was > killing my system. I.e. I still get that message, though everything > else appears to work and it appears to be harmless (I hope). > > BUG: lock held when returning to user space! > > dmsetup/865 is leaving the kernel with locks still held! > 1 lock held by dmsetup/865: > #0: (&journal->j_barrier){+.+...+}, at: [<c056b84d>] jbd2_journal_lock_updates+0xbd/0xc5 This is an ext4 issue that has been fixed upstream, see: https://bugzilla.redhat.com/show_bug.cgi?id=568503 and it is staged for inclussion in the next kernel (2.6.35): http://git.kernel.org/?p=linux/kernel/git/tytso/ext4.git;a=commit;h=74a8f0090293696a716c728f9cd484b45083937f -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
