On Wed, Nov 10, 2021 at 11:14:41AM +0530, Nikhil Kshirsagar wrote: > Hello, > > After a reboot of an Ubuntu server running 4.15.0-143-generic kernel, > the storage devices using bcache do not come back up and the following > stack traces are seen in kern.log. Please could someone help me > understand if this is due to a full bcache journal? Is there any > workaround, or fix? Your journal is completely full, so persisting the new btree root while doing journal replay is hanging. There isn't a _good_ solution for this journal deadlock in bcache (it's fixed in bcachefs), but there is a hack: edit drivers/md/bcache/btree.c line 2493 delete the call to bch_journal_meta(), and build a new kernel. Once you've gotten it to register, do a clean shutdown and then go back to a stock kernel. Running the kernel with that call deleted won't be safe if you crash, but it'll get you going again.
