http://bugzilla.novell.com/show_bug.cgi?id=908706 --- Comment #15 from Neil Brown --- Hi Mark, thanks for all the details. Part of the problem is that your /var/cache/fscache is in a 'btrfs' volume. fscache doesn't work on btrfs. It requires the filesystem to provide a 'bmap' interface user e.g. by the FIBMAP ioctl. btrfs doesn't provide that (for good reason). fscache (or more acturately: cachefiles which is the cache backend in use) refuses to work if bmap isn't available, and this results in the [ 859.668561] CacheFiles: Lookup failed error -1 [ 859.672224] CacheFiles: Lookup failed error -1 [ 859.675402] CacheFiles: Lookup failed error -1 [ 859.694269] CacheFiles: Lookup failed error -1 messages, and results in all the files always being empty. The crash: [ 859.700614] FS-Cache: Assertion failed [ 859.700704] ------------[ cut here ]------------ [ 859.700765] kernel BUG at ../fs/fscache/operation.c:38! seems to be caused by the object being removed from the cache before it has even been added. I suspect that is being caused because creating the object fails due to the lack of 'bmap'. Is there any way you can mount some other filesystem on /var/cache/fscache? You could possible create a large file somewhere, then losetup /dev/loop0 /my/large/file mkfs.ext4 /dev/loop0 mount /dev/loop0 /var/cache/fscache Then restart cachefilesd. -- You are receiving this mail because: You are on the CC list for the bug.