Hi,
I wrote an IETF draft proposing a few new attributes for NFSv4.2.
Since there did not seem to be interest in them, I just
let the draft expire. However, David Noveck pinged
me w.r.t. it, so I thought I'd ask here about it.
All the attributes are meant to be "read only, per server file system":
supported_ops - A bitmap of the operations supported.
The motivation was that NFS4ERR_NOTSUPP is supposed to
be "per server", although the rumour was that the Linux knfsd
uses it "per server file system".
dir_cookie_rising - Only useful for directory delegations, which no
one seems to be implementing.
seek_granularity - The smallest size of unallocated region reported
be the Seek operation. FreeBSD has a pathconf(2) variable called
_PC_MIN_HOLE_SIZE that an application can use to decide if
lseek(SEEK_DATA/SEEK_HOLE) is useful.
mandatory_br_locks - Byte range locks are mandatory. No one
seems to be implementing these, but a client needs to know
that mandatory locking is being enforced so that it can cache
data correctly.
max_xattr_len - Allows the client to avoid attempting to Setxattr an
attribute that is larger than the server file system supports.
So, does the Linux folk think any of these are useful enough to implement?
If not, I do not see any reason to pursue this further.
Thanks for any comments, rick
