Oops in rmmod cifs if done soon after the last mount.
Sorry typo in the previous comment - I meant rmmod cifs can oops if done immediately after the last unmount
http://kernel.org/git/?p=linux/kernel/git/sfrench/cifs-2.6.git;a=commitdiff;h=f191401f5906f4d942fac87ebeb4671faf1ba7d6;hp=1982c344f1bf08118f7c224958b30c64e162009e
Changeset included above. Will push to mainline after 2.6.12