The session client is manipulated under the client_lock hence
both free_session and nfsd4_del_conns must be called under this lock.

This patch adds a BUG_ON that checks this condition in the
respective functions and implements the missing locks.

nfsd4_{get,put}_session helpers were moved to the C file that uses them
so to prevent use from external files and an unlocked version of
nfsd4_put_session is provided for external use from nfs4xdr.c
Signed-off-by: NBenny Halevy <bhalevy@tonian.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This fixes an oops when a buggy client tries to use an initial seqid of
0 on a new slot, which we may misinterpret as a replay.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Combine two booleans into a single flag field, move the smaller fields
to the end.

(In practice this doesn't make the struct any smaller.  But we'll be
adding another flag here soon.)

Remove some debugging code that doesn't look useful, while we're in the
neighborhood.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

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

Address the possible performance regression mentioned in "nfsd4: hash
lockowners to simplify RELEASE_LOCKOWNER" by providing a separate
(lockowner, inode) hash.

Really, I doubt this matters much, but I think it's likely we'll change
these data structures here and I'd rather that the need for (owner,
inode) lookups be well-documented.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Move idr preallocation out of stateid initialization, into stateid
allocation, so that we no longer have to handle any errors from the
former.

This is a little subtle due to the way the idr code manages these
preallocated items--document that in comments.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If process_open1() creates a new open owner, but the open later fails,
the current code will leave the open owner around.  It won't be on the
close_lru list, and the client isn't expected to send a CLOSE, so it
will hang around as long as the client does.

Similarly, if process_open1() removes an existing open owner from the
close lru, anticipating that an open owner that previously had no
associated stateid's now will, but the open subsequently fails, then
we'll again be left with the same leak.

Fix both problems.
Reported-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

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

These comments are mostly out of date.
Reported-by: NBryan Schumaker <bjschuma@netapp.com>

In response to some review comments, get rid of the somewhat obscure
for-loop with bitops, and improve a comment.
Reported-by: NSteve Dickson <steved@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Use a separate stateid idr per client, and lookup a stateid by first
finding the client, then looking up the stateid relative to that client.

Also some minor refactoring.

This allows us to improve error returns: we can return expired when the
clientid is not found and bad_stateid when the clientid is found but not
the stateid, as opposed to returning expired for both cases.

I hope this will also help to replace the state lock mostly by a
per-client lock, but that hasn't been done yet.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Test_stateid is 4.1-only and only allowed after a sequence operation, so
this check is unnecessary.

Cc: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The idr system is designed exactly for generating id and looking up
integer id's.  Thanks to Trond for pointing it out.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This will be convenient.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Look up closed stateid's in the stateid hash like any other stateid
rather than searching the close lru.

This is simpler, and fixes a bug: currently we handle only the case of a
close that is the last close for a given stateowner, but not the case of
a close for a stateowner that still has active opens on other files.
Thus in a case like:

	open(owner, file1)
	open(owner, file2)
	close(owner, file2)
	close(owner, file2)

the final close won't be recognized as a retransmission.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Including the full clientid in the on-the-wire stateid allows more
reliable detection of bad vs. expired stateid's, simplifies code, and
ensures we won't reuse the opaque part of the stateid (as we currently
do when the same openowner closes and reopens the same file).
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Keep around an unhashed copy of the final stateid after the last close
using an openowner, and when identifying a replay, match against that
stateid instead of just against the open owner id.  Free it the next
time the seqid is bumped or the stateowner is destroyed.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

I want at least one more bit here.  So, let's haul out the caps lock key
and add a flags field.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

It's simpler to look up delegation stateid's in the same hash table as
any other stateid.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

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

We want delegations to share more with open/lock stateid's, so first
we'll pull out some of the common stuff we want to share.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We're only using those flags to choose lock or open stateid's at this
point.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Move most of this into helper functions.  Also move the non-CONFIRM case
into caller, providing a helper function for that purpose.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The stateowner has some fields that only make sense for openowners, and
some that only make sense for lockowners, and I find it a lot clearer if
those are separated out.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Move the CLOSE_STATE case into the unique caller that cares about it
rather than putting it in preprocess_seqid_op.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Maybe we'll bring it back some day, but we don't have much real use for
it now.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Follow the recommendation from rfc3530bis for stateid generation number
wraparound, simplify some code, and fix or remove incorrect comments.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The trick free_stateid is using is a little cheesy, and we'll have more
uses for this field later.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Wow, I wonder how long that typo's been there.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This flag doesn't really buy us anything.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Move around some of this code, simplify a bit.
Reviewed-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The set of errors here does *not* agree with the set of errors specified
in the rfc!

While we're there, turn this macros into a function, for the usual
reasons, and move it to the one place where it's actually used.

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

This operation is used by the client to check the validity of a list of
stateids.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

A couple fields here were left over from a previous version of a patch,
and are no longer used.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Instead of acquiring one lease each time another client opens a file,
nfsd can acquire just one lease to represent all of them, and reference
count it to determine when to release it.

This fixes a regression introduced by
c45821d2 "locks: eliminate fl_mylease
callback": after that patch, only the struct file * is used to determine
who owns a given lease.  But since we recently converted the server to
share a single struct file per open, if we acquire multiple leases on
the same file from nfsd, it then becomes impossible on unlocking a lease
to determine which of those leases (all of whom share the same struct
file *) we meant to remove.

Thanks to Takashi Iwai <tiwai@suse.de> for catching a bug in a previous
version of this patch.
Tested-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If we lose the backchannel and then the client repairs the problem,
resend any callbacks.

We use a new cb_done flag to track whether there is still work to be
done for the callback or whether it can be destroyed with the rpc.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If this loses any backchannel, make sure we have a chance to notice that
and set the sequence flags.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Distinguish between when the callback channel is known to be down, and
when it is not yet confirmed.  This will be useful in the 4.1 case.

Also, we don't seem to be using the fact that this field is atomic.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Basic xdr and processing for BIND_CONN_TO_SESSION.  This adds a
connection to the list of connections associated with a session.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>