From: <viro@parcelfarce.linux.theplanet.co.uk>

cramfs and freevxfs explicitly mark themselves readonly (as other r/o fs
do).

afs marked noatime (ACKed by maintainer)

filesystems that do not do update_atime() in their ->readdir() had been
explicitly marked nodiratime.  NOTE: cifs, coda and ncpfs almost certainly
need full noatime as we currently have in nfs and afs.

update_atime() call shifted to callers of ->readdir() and out of
->readdir() instances.  Bugs caught:

  dcache_readdir() updated atime only if it reached EOF.

  bfs_readdir() - ditto.

  qnx4_readdir() - ditto.