Preparation for removal of the client_mutex, which currently protects
this array. While we don't actually need the find_*_file_locked variants
just yet, a later patch will. So go ahead and add them now to reduce
future churn in this code.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Access to this list is currently serialized by the client_mutex. Add
finer grained locking around this list in preparation for its removal.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
lookup_clientid is preferable to find_confirmed_client since it's able
to use the cached client in the compound state.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
If the client were to disappear from underneath us while we're holding
a session reference, things would be bad. This cleanup helps ensure
that it cannot, which will be a possibility when the client_mutex is
removed.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Now that we know that we won't have several lockowners with the same,
owner->data, we can simplify nfsd4_release_lockowner and get rid of
the lo_list in the process.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Just like open-owners, lock-owners are associated with a name, a clientid
and, in the case of minor version 0, a sequence id. There is no association
to a file.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
In the NFSv4 spec, lock stateids are per-file objects. Lockowners are not.
This patch replaces the current list of lock owners in the open stateids
with a list of lock stateids.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Move the slot return, put session etc into a helper in fs/nfsd/nfs4state.c
instead of open coding in nfs4svc_encode_compoundres.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The client is actually asking for 2532 bytes. I suspect that's a
mistake. But maybe we can allow some more. In theory lock needs more
if it might return a maximum-length lockowner in the denied case.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
They do not need to be used outside fs/nfsd/nfs4state.c
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The only real user of this header is fs/nfsd/nfsfh.h, so merge the
two. Various lockѕ source files used it to indirectly get other
sunrpc or nfs headers, so fix those up.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Do a minimal SP4_MACH_CRED implementation suggested by Trond, ignoring
the client-provided spo_must_* arrays and just enforcing credential
checks for the minimum required operations.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
A 4.1 server must notify a client that has had any state revoked using
the SEQ4_STATUS_RECALLABLE_STATE_REVOKED flag. The client can figure
out exactly which state is the problem using CHECK_STATEID and then free
it using FREE_STATEID. The status flag will be unset once all such
revoked stateids are freed.
Our server's only recallable state is delegations. So we keep with each
4.1 client a list of delegations that have timed out and been recalled,
but haven't yet been freed by FREE_STATEID.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Closed stateid's are kept around a little while to handle close replays
in the 4.0 case. So we stash them in the last-used stateid in the
oo_last_closed_stateid field of the open owner. We can free that in
encode_seqid_op_tail once the seqid on the open owner is next
incremented. But we don't want to do that on the close itself; so we
set NFS4_OO_PURGE_CLOSE flag set on the open owner, skip freeing it the
first time through encode_seqid_op_tail, then when we see that flag set
next time we free it.
This is unnecessarily baroque.
Instead, just move the logic that increments the seqid out of the xdr
code and into the operation code itself.
The justification given for the current placement is that we need to
wait till the last minute to be sure we know whether the status is a
sequence-id-mutating error or not, but examination of the code shows
that can't actually happen.
Reported-by: Yanchuan Nian <ycnian@gmail.com>
Tested-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We only ever traverse the hash chains in the forward direction, so a
double pointer list head isn't really necessary.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This changes session destruction to be similar to client destruction in
that attempts to destroy a session while in use (which should be rare
corner cases) result in DELAY. This simplifies things somewhat and
helps meet a coming 4.2 requirement.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When a setclientid_confirm or create_session confirms a client after a
client reboot, it also destroys any previous state held by that client.
The shutdown of that previous state must be careful not to free the
client out from under threads processing other requests that refer to
the client.
This is a particular problem in the NFSv4.1 case when we hold a
reference to a session (hence a client) throughout compound processing.
The server attempts to handle this by unhashing the client at the time
it's destroyed, then delaying the final free to the end. But this still
leaves some races in the current code.
I believe it's simpler just to fail the attempt to destroy the client by
returning NFS4ERR_DELAY. This is a case that should never happen
anyway.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Change uid and gid in struct nfsd4_cb_sec to be of type kuid_t and
kgid_t.
In nfsd4_decode_cb_sec when reading uids and gids off the wire convert
them to kuids and kgids, and if they don't convert to valid kuids or
valid kuids ignore RPC_AUTH_UNIX and don't fill in any of the fields.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Write the client's ip address to any state file and all appropriate
state for that client will be forgotten.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
I also log basic information that I can figure out about the type of
state (such as number of locks for each client IP address). This can be
useful for checking that state was actually dropped and later for
checking if the client was able to recover.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The eventual goal is to forget state based on ip address, so it makes
sense to call this function in a for-each-client loop until the correct
amount of state is forgotten. I also use this patch as an opportunity
to rename the forget function from "func()" to "forget()".
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There were only a small number of functions in this file and since they
all affect stored state I think it makes sense to put them in state.h
instead. I also dropped most static inline declarations since there are
no callers when fault injection is not enabled.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Passing net context looks as overkill.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This patch replaces init_net by SVC_NET(), where possible and also passes
proper context to nested functions where required.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This hash holds nfs4_clients info, which are network namespace aware.
So let's make it allocated per network namespace.
Note: this hash is used only by legacy tracker. So let's allocate hash in
tracker init.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Remove the cl_recdir field from the nfs4_client struct. Instead, just
compute it on the fly when and if it's needed, which is now only when
the legacy client tracking code is in effect.
The error handling in the legacy client tracker is also changed to
handle the case where md5 is unavailable. In that case, we'll warn
the admin with a KERN_ERR message and disable the client tracking.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The current code requires that we md5 hash the name in order to store
the client in the confirmed and unconfirmed trees. Change it instead
to store the clients in a pair of rbtrees, and simply compare the
cl_names directly instead of hashing them. This also necessitates that
we add a new flag to the clp->cl_flags field to indicate which tree
the client is currently in.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When nfsd starts, the legacy reboot recovery code creates a tracking
struct for each directory in the v4recoverydir. When the grace period
ends, it basically does a "readdir" on the directory again, and matches
each dentry in there to an existing client id to see if it should be
removed or not. If the matching client doesn't exist, or hasn't
reclaimed its state then it will remove that dentry.
This is pretty inefficient since it involves doing a lot of hash-bucket
searching. It also means that we have to keep relying on being able to
search for a nfs4_client by md5 hashed cl_recdir name.
Instead, add a pointer to the nfs4_client that indicates the association
between the nfs4_client_reclaim and nfs4_client. When a reclaim operation
comes in, we set the pointer to make that association. On gracedone, the
legacy client tracker will keep the recdir around iff:
1/ there is a reclaim record for the directory
...and...
2/ there's an association between the reclaim record and a client record
-- that is, a create or check operation was performed on the client that
matches that directory.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Later callers will need to make changes to the record.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We'll need to be able to call this from nfs4recover.c eventually.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Currently, it takes a client pointer, but later we're going to need to
search for these records without knowing whether a matching client even
exists.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
For now this only adds support for AUTH_NULL. (Previously we assumed
AUTH_UNIX.) We'll also need AUTH_GSS, which is trickier.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We're currently ignoring the callback security parameters specified in
create_session, and just assuming the client wants auth_sys, because
that's all the current linux client happens to care about. But this
could cause us callbacks to fail to a client that wanted something
different.
For now, all we're doing is no longer ignoring the uid and gid passed in
the auth_sys case. Further patches will add support for auth_null and
gss (and possibly use more of the auth_sys information; the spec wants
us to use exactly the credential we're passed, though it's hard to
imagine why a client would care).
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Something like creating a client with setclientid and then trying to
confirm it with create_session may not crash the server, but I'm not
completely positive of that, and in any case it's obviously bad client
behavior.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
locks.c doesn't use the BKL anymore and there is no fi_perfile field.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Commit d5497fc693 "nfsd4: move rq_flavor
into svc_cred" forgot to remove cl_flavor from the client, leaving two
places (cl_flavor and cl_cred.cr_flavor) for the flavor to be stored.
After that patch, the latter was the one that was updated, but the
former was the one that the callback used.
Symptoms were a long delay on utime(). This is because the utime()
generated a setattr which recalled a delegation, but the cb_recall was
ignored by the client because it had the wrong security flavor.
Cc: stable@vger.kernel.org
Tested-by: Jamie Heilman <jamie@audible.transient.net>
Reported-by: Jamie Heilman <jamie@audible.transient.net>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
NFSd's boot_time represents grace period start point in time.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Passed network namespace replaced hard-coded init_net
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
According to RFC 5661, the TEST_STATEID operation is not allowed to
return NFS4ERR_STALE_STATEID. In addition, RFC 5661 says:
15.1.16.5. NFS4ERR_STALE_STATEID (Error Code 10023)
A stateid generated by an earlier server instance was used. This
error is moot in NFSv4.1 because all operations that take a stateid
MUST be preceded by the SEQUENCE operation, and the earlier server
instance is detected by the session infrastructure that supports
SEQUENCE.
I triggered NFS4ERR_STALE_STATEID while testing the Linux client's
NOGRACE recovery. Bruce suggested an additional test that could be
useful to client developers.
Lastly, RFC 5661, section 18.48.3 has this:
o Special stateids are always considered invalid (they result in the
error code NFS4ERR_BAD_STATEID).
An explicit check is made for those state IDs to avoid printk noise.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Instead of keeping the principal name associated with a request in a
structure that's private to auth_gss and using an accessor function,
move it to svc_cred.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Abstract out the mechanism that we use to track clients into a set of
client name tracking functions.
This gives us a mechanism to plug in a new set of client tracking
functions without disturbing the callers. It also gives us a way to
decide on what tracking scheme to use at runtime.
For now, this just looks like pointless abstraction, but later we'll
add a new alternate scheme for tracking clients on stable storage.
Note too that this patch anticipates the eventual containerization
of this code by passing in struct net pointers in places. No attempt
is made to containerize the legacy client tracker however.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We'll need a way to flag the nfs4_client as already being recorded on
stable storage so that we don't continually upcall. Currently, that's
recorded in the cl_firststate field of the client struct. Using an
entire u32 to store a flag is rather wasteful though.
The cl_cb_flags field is only using 2 bits right now, so repurpose that
to a generic flags field. Rename NFSD4_CLIENT_KILL to
NFSD4_CLIENT_CB_KILL to make it evident that it's part of the callback
flags. Add a mask that we can use for existing checks that look to see
whether any flags are set, so that the new flags don't interfere.
Convert all references to cl_firstate to the NFSD4_CLIENT_STABLE flag,
and add a new NFSD4_CLIENT_RECLAIM_COMPLETE flag.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: J. 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: J. 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: J. 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: J. 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: J. 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: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
In response to some review comments, get rid of the somewhat obscure
for-loop with bitops, and improve a comment.
Reported-by: Steve Dickson <steved@redhat.com>
Signed-off-by: J. 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: J. 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: J. 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: J. 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: J. 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: J. 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: J. 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: J. 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: J. 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: J. 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: J. 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: J. 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: J. Bruce Fields <bfields@redhat.com>
This operation is used by the client to check the validity of a list of
stateids.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. 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
c45821d263 "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: Takashi Iwai <tiwai@suse.de>
Signed-off-by: J. 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: J. 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: J. 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: J. 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: J. Bruce Fields <bfields@redhat.com>
when callback is generated in NFSv4 server, it doesn't set the source
address. When an alias IP is utilized on NFSv4 server and suppose the
client is accessing via that alias IP (e.g. eth0:0), the client invokes
the callback to the IP address that is set on the original device (e.g.
eth0). This behavior results in timeout of xprt.
The patch sets the IP address that the client should invoke callback to.
Signed-off-by: Takuma Umeya <tumeya@redhat.com>
[bfields@redhat.com: Simplify gen_callback arguments, use helper function]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When we converted to sharing struct filess between nfs4 opens I went too
far and also used the same mechanism for delegations. But keeping
a reference to the struct file ensures it will outlast the lease, and
allows us to remove the lease with the same file as we added it.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The minorversion seems more a property of the client than the callback
channel.
Some time we should probably also enforce consistent minorversion usage
from the client; for now, this is just a cosmetic change.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Only one of the nfsd4_callback_probe callers actually cares about
changing the callback information.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The callback program is allowed to depend on the session which the
callback is going over.
No change in behavior yet, while we still only do callbacks over a
single session for the lifetime of the client.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Currently we don't deal well with a client that has multiple sessions
associated with it (even simultaneously, or serially over the lifetime
of the client).
In particular, we don't attempt to keep the backchannel running after
the original session diseappears.
We will fix that soon.
Once we do that, we need the slot sequence number to be per-session;
otherwise, for example, we cannot correctly handle a case like this:
- All session 1 connections are lost.
- The client creates session 2. We use it for the backchannel
(since it's the only working choice).
- The client gives us a new connection to use with session 1.
- The client destroys session 2.
At this point our only choice is to go back to using session 1. When we
do so we must use the sequence number that is next for session 1. We
therefore need to maintain multiple sequence number streams.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Instead of copying the sessionid, use the new cl_cb_session pointer,
which indicates which session we're using for the backchannel.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The backchannel should be associated with a session, it isn't really
global to the client.
We do, however, want a pointer global to the client which tracks which
session we're currently using for client-based callbacks.
This is a first step in that direction; for now, just reshuffling of
code with no significant change in behavior.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The spec requires us in various places to keep track of the connections
associated with each session.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Instead of creating the new rpc client from a regular server thread,
set a flag, kick off a null call, and allow the null call to do the work
of setting up the client on the callback workqueue.
Use a spinlock to ensure the callback work gets a consistent view of the
callback parameters.
This allows, for example, changing the callback from contexts where
sleeping is not allowed. I hope it will also keep the locking simple as
we add more session and trunking features, by serializing most of the
callback-specific work.
This also closes a small race where the the new cb_ident could be used
with an old connection (or vice-versa).
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
