RPC_MAX_AUTH_SIZE is scattered around several places.  Better to set it
once in the auth code, where this kind of estimate should be made.  And
while we're at it we can leave it zero when we're not using krb5i or
krb5p.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Otherwise a following patch would turn off all 4.1 zero-copy reads.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We plan to use this estimate to decide whether or not to allow zero-copy
reads.  Currently we're assuming all getattr's are a page, which can be
both too small (ACLs e.g. may be arbitrarily long) and too large (after
an upcoming read patch this will unnecessarily prevent zero copy reads
in any read compound also containing a getattr).
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Currently we limit readdir results to a single page.  This can result in
a performance regression compared to NFSv3 when reading large
directories.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

It will turn out to be useful to have a more accurate estimate of reply
size; so, piggyback on the existing op reply-size estimators.

Also move nfsd4_max_reply to nfs4proc.c to get easier access to struct
nfsd4_operation and friends.  (Thanks to Christoph Hellwig for pointing
out that simplification.)
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

I ran into this corner case in testing: in theory clients can provide
state owners up to 1024 bytes long.  In the sessions case there might be
a risk of this pushing us over the DRC slot size.

The conflicting owner isn't really that important, so let's humor a
client that provides a small maxresponsize_cached by allowing ourselves
to return without the conflicting owner instead of outright failing the
operation.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

After this we can handle for example getattr of very large ACLs.

Read, readdir, readlink are still special cases with their own limits.

Also we can't handle a new operation starting close to the end of a
page.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Better variable name, some comments, etc.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Now that all op encoders can handle running out of space, we no longer
need to check the remaining size for every operation; only nonidempotent
operations need that check, and that can be done by
nfsd4_check_resp_size.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We've tried to prevent running out of space with COMPOUND_SLACK_SPACE
and special checking in those operations (getattr) whose result can vary
enormously.

However:
	- COMPOUND_SLACK_SPACE may be difficult to maintain as we add
	  more protocol.
	- BUG_ON or page faulting on failure seems overly fragile.
	- Especially in the 4.1 case, we prefer not to fail compounds
	  just because the returned result came *close* to session
	  limits.  (Though perfect enforcement here may be difficult.)
	- I'd prefer encoding to be uniform for all encoders instead of
	  having special exceptions for encoders containing, for
	  example, attributes.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Note this makes ADJUST_ARGS useless; we'll remove it in the following
patch.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This is a cosmetic change for now; no change in behavior.

Note we're just depending on xdr_reserve_space to do the bounds checking
for us, we're not really depending on its adjustment of iovec or xdr_buf
lengths yet, as those are fixed up by as necessary after the fact by
read-link operations and by nfs4svc_encode_compoundres.  However we do
have to update xdr->iov on read-like operations to prevent
xdr_reserve_space from messing with the already-fixed-up length of the
the head.

When the attribute encoding fails partway through we have to undo the
length adjustments made so far.  We do it manually for now, but later
patches will add an xdr_truncate_encode() helper to handle cases like
this.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If nfsd4_check_resp_size() returns an error then we should really be
truncating the reply here, otherwise we may leave extra garbage at the
end of the rpc reply.

Also add a warning to catch any cases where our reply-size estimates may
be wrong in the case of a non-idempotent operation.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Currently if the nfs-level part of a reply would be too large, we'll
return an error to the client.  But if the nfs-level part fits and
leaves no room for krb5p or krb5i stuff, then we just drop the request
entirely.

That's no good.  Instead, reserve some slack space at the end of the
buffer and make sure we fail outright if we'd come close.

The slack space here is a massive overstimate of what's required, we
should probably try for a tighter limit at some point.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Mechanical transformation with no change of behavior.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Just change the nfsd4_encode_getattr api.  Not changing any code or
adding any new functionality yet.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This is a mechanical transformation with no change in behavior.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Currently a non-idempotent op reply may be cached if it fails in the
proc code but not if it fails at xdr decoding.  I doubt there are any
xdr-decoding-time errors that would make this a problem in practice, so
this probably isn't a serious bug.

The space estimates should also take into account space required for
encoding of error returns.  Again, not a practical problem, though it
would become one after future patches which will tighten the space
estimates.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The write reply also includes count and stable_how.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

OP_MODIFIES_SOMETHING flags operations that we should be careful not to
initiate without being sure we have the buffer space to encode a reply.

None of these ops fall into that category.

We could probably remove a few more, but this isn't a very important
problem at least for ops whose reply size is easy to estimate.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Move the state locking and file descriptor reference out from the
callers and into nfs4_preprocess_stateid_op() itself.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Testing NFS4.0 by pynfs, I got some messeages as,
"nfsd: inode locked twice during operation."

When one compound RPC contains two or more ops that locks
the filehandle,the second op will cause the message.

As two SETATTR ops, after the first SETATTR, nfsd will not call
fh_put() to release current filehandle, it means filehandle have
unlocked with fh_post_saved = 1.
The second SETATTR find fh_post_saved = 1, and printk the message.

v2: introduce helper fh_clear_wcc().
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If a file is unlinked or renamed between the time when we do the local
open and the time when we get the delegation, then we will return to the
client indicating that it holds a delegation even though the file no
longer exists under the name it was open under.

But a client performing an open-by-name, when it is returned a
delegation, must be able to assume that the file is still linked at the
name it was opened under.

So, hold the parent i_mutex for longer to prevent concurrent renames or
unlinks.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This is basically a no-op, to simplify a following patch.
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Remove the boilerplate code to marshall and unmarhall ACL objects into
xattrs and operate on the posix_acl objects directly.  Also move all
the ACL handling code into nfs?acl.c where it belongs.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This confuses me every time.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

NFSv4 clients can contact port 2049 directly instead of needing the
portmapper.

Therefore a failure to register to the portmapper when starting an
NFSv4-only server isn't really a problem.

But Gareth Williams reports that an attempt to start an NFSv4-only
server without starting portmap fails:

  #rpc.nfsd -N 2 -N 3
  rpc.nfsd: writing fd to kernel failed: errno 111 (Connection refused)
  rpc.nfsd: unable to set any sockets for nfsd

Add a flag to svc_version to tell the rpc layer it can safely ignore an
rpcbind failure in the NFSv4-only case.
Reported-by: NGareth Williams <gareth@garethwilliams.me.uk>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

commit 58cd57bf
"nfsd: Fix SP4_MACH_CRED negotiation in EXCHANGE_ID"
miss calculating the length of bitmap for spo_must_enforce and spo_must_allow.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

 - don't BUG_ON() when not SP4_NONE
 - calculate recv and send reserve sizes correctly
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

You can turn on or off support for minorversions using e.g.

	echo "-4.2" >/proc/fs/nfsd/versions

However, the current implementation is a little wonky.  For example, the
above will turn off 4.2 support, but it will also turn *on* 4.1 support.

This didn't matter as long as we only had 2 minorversions, which was
true till very recently.

And do a little cleanup here.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We saw a v4.0 client's create fail as follows:

	- open create succeeds and gets a read delegation
	- client attempts to set mode on new file, gets DELAY while
	  server recalls delegation.
	- client attempts a CLAIM_DELEGATE_CUR open using the
	  delegation, gets error because of new file mode.

This probably can't happen on a recent kernel since we're no longer
giving out delegations on create opens.  Nevertheless, it's a
bug--reclaim opens should bypass permission checks.
Reported-by: NSteve Dickson <steved@redhat.com>
Reported-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Implement labeled NFS on the server: encoding and decoding, and writing
and reading, of file labels.

Enabled with CONFIG_NFSD_V4_SECURITY_LABEL.
Signed-off-by: NMatthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: NMiguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: NPhua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: NKhin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The Linux client is using CLAIM_FH to implement regular opens, not just
recovery cases, so it depends on the server to check permissions
correctly.

Therefore the owner override, which may make sense in the delegation
recovery case, isn't right in the CLAIM_FH case.

Symptoms: on a client with 49f9a0fa
"NFSv4.1: Enable open-by-filehandle", Bryan noticed this:

	touch test.txt
	chmod 000 test.txt
	echo test > test.txt

succeeding.

Cc: stable@kernel.org
Reported-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We're going out of our way here to remap an error to make rfc 3530
happy--but the rfc itself (nor rfc 1813, which has similar language)
gives no justification.  And disagrees with local filesystem behavior,
with Linux and posix man pages, and knfsd's implemented behavior for v2
and v3.

And the documented behavior seems better, in that it gives a little more
information--you could implement the 3530 behavior using the posix
behavior, but not the other way around.

Also, the Linux client makes no attempt to remap this error in the v4
case, so it can end up just returning EEXIST to the application in a
case where it should return EISDIR.

So honestly I think the rfc's are just buggy here--or in any case it
doesn't see worth the trouble to remap this error.
Reported-by: NFrank S Filz <ffilz@us.ibm.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

More logic that's unnecessary in the 4.1 case.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>