Without the patch, there is a leakage of nlmblock structure refcount
that holds a reference nlmfile structure, that holds a reference to
struct file, when async GETFL is used (-EINPROGRESS return from
file_ops->lock()), and also in some error cases.

Fix up a style nit while we're here.
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

This patch addresses a compatibility issue with a Linux NFS server and
AIX NFS client.

I have exported /export as fsid=0 with sec=krb5:krb5i
I have mount --bind /home onto /export/home
I have exported /export/home with sec=krb5i

The AIX client mounts / -o sec=krb5:krb5i onto /mnt

If I do an ls /mnt, the AIX client gets a permission error. Looking at
the network traceIwe see a READDIR looking for attributes
FATTR4_RDATTR_ERROR and FATTR4_MOUNTED_ON_FILEID. The response gives a
NFS4ERR_WRONGSEC which the AIX client is not expecting.

Since the AIX client is only asking for an attribute that is an
attribute of the parent file system (pseudo root in my example), it
seems reasonable that there should not be an error.

In discussing this issue with Bruce Fields, I initially proposed
ignoring the error in nfsd4_encode_dirent_fattr() if all that was being
asked for was FATTR4_RDATTR_ERROR and FATTR4_MOUNTED_ON_FILEID, however,
Bruce suggested that we avoid calling cross_mnt() if only these
attributes are requested.

The following patch implements bypassing cross_mnt() if only
FATTR4_RDATTR_ERROR and FATTR4_MOUNTED_ON_FILEID are called. Since there
is some complexity in the code in nfsd4_encode_fattr(), I didn't want to
duplicate code (and introduce a maintenance nightmare), so I added a
parameter to nfsd4_encode_fattr() that indicates whether it should
ignore cross mounts and simply fill in the attribute using the passed in
dentry as opposed to it's parent.
Signed-off-by: Frank Filz <ffilzlnx@us.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

The failure to return a stateowner from nfs4_preprocess_seqid_op() means
in the case where a lock request is of a type incompatible with an open
(due to, e.g., an application attempting a write lock on a file open for
read), means that fs/nfsd/nfs4xdr.c:ENCODE_SEQID_OP_TAIL() never bumps
the seqid as it should.  The client, attempting to close the file
afterwards, then gets an (incorrect) bad sequence id error.  Worse, this
prevents the open file from ever being closed, so we leak state.

Thanks to Benny Halevy and Trond Myklebust for analysis, and to Steven
Wilton for the report and extensive data-gathering.

Cc: Benny Halevy <bhalevy@panasas.com>
Cc: Steven Wilton <steven.wilton@team.eftel.com.au>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

In a number of places where we wish only to translate nlm_drop_reply to
rpc_drop_reply errors we instead return early with rpc_drop_reply,
skipping some important end-of-function cleanup.

This results in reference count leaks when lockd is doing posix locking
on GFS2.
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

When the callback channel fails, we inform the client of that by
returning a cb_path_down error the next time it tries to renew its
lease.

If we wait most of a lease period before deciding that a callback has
failed and that the callback channel is down, then we decrease the
chances that the client will find out in time to do anything about it.

So, mark the channel down as soon as we recognize that an rpc has
failed.  However, continue trying to recall delegations anyway, in hopes
it will come back up.  This will prevent more delegations from being
given out, and ensure cb_path_down is returned to renew calls earlier,
while still making the best effort to deliver recalls of existing
delegations.

Also fix a couple comments and remove a dprink that doesn't seem likely
to be useful.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Fix various minor style violations.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Declare this variable in the one function where it's used, and clean up
some minor style problems.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Fix bizarre indentation.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

We generate a unique cl_confirm for every new client; so if we've
already checked that this cl_confirm agrees with the cl_confirm of
unconf, then we already know that it does not agree with the cl_confirm
of conf.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Again, the only way conf and unconf can have the same clientid is if
they were created in the "probable callback update" case of setclientid,
in which case we already know that the cl_verifier fields must agree.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

If conf and unconf are both found in the lookup by cl_clientid, then
they share the same cl_clientid.  We always create a unique new
cl_clientid field when creating a new client--the only exception is the
"probable callback update" case in setclientid, where we copy the old
cl_clientid from another clientid with the same name.

Therefore two clients with the same cl_client field also always share
the same cl_name field, and a couple of the checks here are redundant.

Thanks to Simon Holm Thøgersen for a compile fix.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Simon Holm Thøgersen <odie@cs.aau.dk>

Using a counter instead of the nanoseconds value seems more likely to
produce a unique cl_confirm.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

We're supposed to generate a different cl_confirm verifier for each new
client, so these to cl_confirm values should never be the same.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Most of these comments just summarize the code.

The matching of code to the cases described in the RFC may still be
useful, though; add specific section references to make that easier to
follow.  Also update references to the outdated RFC 3010.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

While we're here, let's remove the redundant (and now wrong) pathname in
the comment, and the #ifdef __KERNEL__'s.
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

This header is used only in a few places in fs/nfsd, so there seems to
be little point to having it in include/.  (Thanks to Robert Day for
pointing this out.)

Cc: Robert P. J. Day <rpjday@crashcourse.ca>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Newer server features such as nfsv4 and gss depend on proc to work, so a
failure to initialize the proc files they need should be treated as
fatal.

Thanks to Andrew Morton for style fix and compile fix in case where
CONFIG_NFSD_V4 is undefined.

Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Just some minor cleanup.

Also I don't see much point in trying to register further proc entries
if initial entries fail; so just stop trying in that case.
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

I assume the reason failure of creation was ignored here was just to
continue support embedded systems that want nfsd but not proc.

However, in cases where proc is supported it would be clearer to fail
entirely than to come up with some features disabled.
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

The server depends on upcalls under /proc to support nfsv4 and gss.
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

There's really nothing much the caller can do if cache unregistration
fails.  And indeed, all any caller does in this case is print an error
and continue.  So just return void and move the printk's inside
cache_unregister.
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

If the reply cache initialization fails due to a kmalloc failure,
currently we try to soldier on with a reduced (or nonexistant) reply
cache.

Better to just fail immediately: the failure is then much easier to
understand and debug, and it could save us complexity in some later
code.  (But actually, it doesn't help currently because the cache is
also turned off in some odd failure cases; we should probably find a
better way to handle those failure cases some day.)

Fix some minor style problems while we're at it, and rename
nfsd_cache_init() to remove the need for a comment describing it.
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Handle the failure case here with something closer to the standard
kernel style.

Doesn't really matter for now, but I'd like to add a few more failure
cases, and then this'll help.
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

We forgot to shut down the nfs4 state and idmapping code in this case.
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

The length "nbytes" passed into read_buf should never be negative, but
we check only for too-large values of "nbytes", not for too-small
values.  Make nbytes unsigned, so it's clear that the former tests are
sufficient.  (Despite this read_buf() currently correctly returns an xdr
error in the case of a negative length, thanks to an unsigned
comparison with size_of() and bounds-checking in kmalloc().  This seems
very fragile, though.)
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

The path here must be left over from some earlier draft; fix it.  And do
some more minor cleanup while we're there.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Clean up: For consistency, store the length of path name strings in nfsd
argument structures as unsigned integers.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-By: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-By: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Clean up: path name lengths are unsigned on the wire, negative lengths
are not meaningful natively either.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-By: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Clean up: adjust the sign of the length argument of nfsd_lookup and
nfsd_lookup_dentry, for consistency with recent changes.  NFSD version
4 callers already pass an unsigned file name length.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-By: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Clean up: For consistency, store the length of file name strings in nfsd
argument structures as unsigned integers.  This matches the XDR routines
and client argument structures for the same operation types.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-By: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Clean up: file name lengths are unsigned on the wire, negative lengths
are not meaningful natively either.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-By: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

According to The Open Group's NLM specification, NLM callers are variable
length strings.  XDR variable length strings use an unsigned 32 bit length.
And internally, negative string lengths are not meaningful for the Linux
NLM implementation.

Clean up: Make nlm_lock.len and nlm_reboot.len unsigned integers.  This
makes the sign of NLM string lengths consistent with the sign of xdr_netobj
lengths.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-By: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

XDR strings, opaques, and net objects should all use unsigned lengths.
To wit, RFC 4506 says:

4.2.  Unsigned Integer

   An XDR unsigned integer is a 32-bit datum that encodes a non-negative
   integer in the range [0,4294967295].

 ...

4.11.  String

   The standard defines a string of n (numbered 0 through n-1) ASCII
   bytes to be the number n encoded as an unsigned integer (as described
   above), and followed by the n bytes of the string.

After this patch, xdr_decode_string_inplace now matches the other XDR
string and array helpers that take a string length argument.  See:

xdr_encode_opaque_fixed, xdr_encode_opaque, xdr_encode_array
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-By: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Make sure we compare an unsigned length to an unsigned count in
read_flush().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Obviously at some point we thought "error" represented the length when
positive.  This appears to be a long-standing typo.

Thanks to Prasad Potluri <pvp@us.ibm.com> for finding the problem and
proposing an earlier version of this patch.

Cc: Steve French <smfltc@us.ibm.com>
Cc: Prasad V Potluri <pvp@us.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Dereferenced pointer "dentry" without checking and assigned to inode
in the declaration.

(We could just delete the NULL checks that follow instead, as we never
get to the encode function in this particular case.  But it takes a
little detective work to verify that fact, so it's probably safer to
leave the checks in place.)

Cc: Steve French <smfltc@us.ibm.com>
Signed-off-by: Prasad V Potluri <pvp@us.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

The whole reason to move this callback-channel probe into a separate
thread was because (for now) we don't have an easy way to create the
rpc_client asynchronously.  But I forgot to move the rpc_create() to the
spawned thread.  Doh!  Fix that.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Our callback code doesn't actually handle concurrent attempts to probe
the callback channel.  Some rethinking of the locking may be required.
However, we can also just move the callback probing to this case.  Since
this is the only time a client is "confirmed" (and since that can only
happen once in the lifetime of a client), this ensures we only probe
once.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  block: kill swap_io_context()
  as-iosched: fix inconsistent ioc->lock context
  ide-cd: fix leftover data BUG
  block: make elevator lib checkpatch compliant
  cfq-iosched: make checkpatch compliant
  block: make core bits checkpatch compliant
  block: new end request handling interface should take unsigned byte counts
  unexport add_disk_randomness
  block/sunvdc.c:print_version() must be __devinit
  splice: always updated atime in direct splice