Comment 5 for bug 885744

SRU justification:

Impact:

statfs() calls on eCryptfs files returned the wrong filesystem type and,
when using filename encryption, the wrong maximum filename length.

If mount-wide filename encryption is enabled, the cipher block size and
the lower filesystem's max filename length will determine the max
eCryptfs filename length. Pre-tested, known good lengths are used when
the lower filesystem's namelen is 255 and a cipher with 8 or 16 byte
block sizes is used. In other, less common cases, we fall back to a safe
rounded-down estimate when determining the eCryptfs namelen.

Fix:

Backport of upstream commit 4a26620df451ad46151ad21d711ed43e963c004e

Testcase:

http://bazaar.launchpad.net/~ecryptfs/ecryptfs/trunk/revision/640
http://bazaar.launchpad.net/~ecryptfs/ecryptfs/trunk/revision/625
[ see test: tests/kernel/lp-885744 ]