misc (mostly callback) patches for 2.6.31

misc (mostly callback) patches for 2.6.31

[J. Bruce Fields]

I intend to submit the following for 2.6.31, mainly concerned with
moving the nfsv4 callbacks to asynchronous rpc's.  Currently we create a
new kthread for each callback.  But there's no real reason they need a
real thread, and I'm assuming an rpc task will be lighter-weight.  This
should also keep the callbacks from outliving the nfsd module (though
that could probably be solved some other way).

Next I'd like to improve the decision about when to declare the callback
channel down, and implement the callback-parameter-changing case of
setclientid (and the corresponding 4.1 case).  For the latter I'm
currently stuck trying to decide how to do the locking necessary to
prevent races between destruction of the old rpc client and
lease-breaking code about to launch a new rpc task using the old rpc
client.

--b.

[PATCH] nfsd4: rename callback struct to cb_conn

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

I want to use the name for a struct that actually does represent a
single callback.

(Actually, I've never been sure it helps to a separate struct for the
callback information.  Some day maybe those fields could just be dumped
into struct nfs4_client.  I don't know.)

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
 fs/nfsd/nfs4callback.c     |   16 ++++++++--------
 fs/nfsd/nfs4state.c        |   22 +++++++++++-----------
 include/linux/nfsd/state.h |    4 ++--
 3 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 0aaf68b..125d731 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -369,7 +369,7 @@ static int max_cb_time(void)
 int setup_callback_client(struct nfs4_client *clp)
 {
 	struct sockaddr_in	addr;
-	struct nfs4_callback    *cb = &clp->cl_callback;
+	struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
 	struct rpc_timeout	timeparms = {
 		.to_initval	= max_cb_time(),
 		.to_retries	= 0,
@@ -422,7 +422,7 @@ static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
 	if (task->tk_status)
 		warn_no_callback_path(clp, task->tk_status);
 	else
-		atomic_set(&clp->cl_callback.cb_set, 1);
+		atomic_set(&clp->cl_cb_conn.cb_set, 1);
 	put_nfs4_client(clp);
 }
 
@@ -430,7 +430,7 @@ static const struct rpc_call_ops nfsd4_cb_probe_ops = {
 	.rpc_call_done = nfsd4_cb_probe_done,
 };
 
-static struct rpc_cred *lookup_cb_cred(struct nfs4_callback *cb)
+static struct rpc_cred *lookup_cb_cred(struct nfs4_cb_conn *cb)
 {
 	struct auth_cred acred = {
 		.machine_cred = 1
@@ -448,7 +448,7 @@ static struct rpc_cred *lookup_cb_cred(struct nfs4_callback *cb)
 
 void do_probe_callback(struct nfs4_client *clp)
 {
-	struct nfs4_callback    *cb = &clp->cl_callback;
+	struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
 	struct rpc_message msg = {
 		.rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
 		.rpc_argp       = clp,
@@ -480,7 +480,7 @@ nfsd4_probe_callback(struct nfs4_client *clp)
 {
 	int status;
 
-	BUG_ON(atomic_read(&clp->cl_callback.cb_set));
+	BUG_ON(atomic_read(&clp->cl_cb_conn.cb_set));
 
 	status = setup_callback_client(clp);
 	if (status) {
@@ -501,12 +501,12 @@ void
 nfsd4_cb_recall(struct nfs4_delegation *dp)
 {
 	struct nfs4_client *clp = dp->dl_client;
-	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
+	struct rpc_clnt *clnt = clp->cl_cb_conn.cb_client;
 	struct nfs4_cb_recall *cbr = &dp->dl_recall;
 	struct rpc_message msg = {
 		.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
 		.rpc_argp = cbr,
-		.rpc_cred = clp->cl_callback.cb_cred
+		.rpc_cred = clp->cl_cb_conn.cb_cred
 	};
 	int retries = 1;
 	int status = 0;
@@ -519,7 +519,7 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
 		switch (status) {
 			case -EIO:
 				/* Network partition? */
-				atomic_set(&clp->cl_callback.cb_set, 0);
+				atomic_set(&clp->cl_cb_conn.cb_set, 0);
 			case -EBADHANDLE:
 			case -NFS4ERR_BAD_STATEID:
 				/* Race: client probably got cb_recall
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index b205c7d..9378586 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -182,7 +182,7 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_stateid *stp, struct svc_f
 {
 	struct nfs4_delegation *dp;
 	struct nfs4_file *fp = stp->st_file;
-	struct nfs4_callback *cb = &stp->st_stateowner->so_client->cl_callback;
+	struct nfs4_cb_conn *cb = &stp->st_stateowner->so_client->cl_cb_conn;
 
 	dprintk("NFSD alloc_init_deleg\n");
 	if (fp->fi_had_conflict)
@@ -633,19 +633,19 @@ static struct nfs4_client *alloc_client(struct xdr_netobj name)
 static void
 shutdown_callback_client(struct nfs4_client *clp)
 {
-	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
+	struct rpc_clnt *clnt = clp->cl_cb_conn.cb_client;
 
 	if (clnt) {
 		/*
 		 * Callback threads take a reference on the client, so there
 		 * should be no outstanding callbacks at this point.
 		 */
-		clp->cl_callback.cb_client = NULL;
+		clp->cl_cb_conn.cb_client = NULL;
 		rpc_shutdown_client(clnt);
 	}
-	if (clp->cl_callback.cb_cred) {
-		put_rpccred(clp->cl_callback.cb_cred);
-		clp->cl_callback.cb_cred = NULL;
+	if (clp->cl_cb_conn.cb_cred) {
+		put_rpccred(clp->cl_cb_conn.cb_cred);
+		clp->cl_cb_conn.cb_cred = NULL;
 	}
 }
 
@@ -719,7 +719,7 @@ static struct nfs4_client *create_client(struct xdr_netobj name, char *recdir)
 		return NULL;
 	memcpy(clp->cl_recdir, recdir, HEXDIR_LEN);
 	atomic_set(&clp->cl_count, 1);
-	atomic_set(&clp->cl_callback.cb_set, 0);
+	atomic_set(&clp->cl_cb_conn.cb_set, 0);
 	INIT_LIST_HEAD(&clp->cl_idhash);
 	INIT_LIST_HEAD(&clp->cl_strhash);
 	INIT_LIST_HEAD(&clp->cl_openowners);
@@ -971,7 +971,7 @@ parse_ipv4(unsigned int addr_len, char *addr_val, unsigned int *cbaddrp, unsigne
 static void
 gen_callback(struct nfs4_client *clp, struct nfsd4_setclientid *se)
 {
-	struct nfs4_callback *cb = &clp->cl_callback;
+	struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
 
 	/* Currently, we only support tcp for the callback channel */
 	if ((se->se_callback_netid_len != 3) || memcmp((char *)se->se_callback_netid_val, "tcp", 3))
@@ -1691,7 +1691,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
 		else {
 			/* XXX: We just turn off callbacks until we can handle
 			  * change request correctly. */
-			atomic_set(&conf->cl_callback.cb_set, 0);
+			atomic_set(&conf->cl_cb_conn.cb_set, 0);
 			expire_client(unconf);
 			status = nfs_ok;
 
@@ -2425,7 +2425,7 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_sta
 {
 	struct nfs4_delegation *dp;
 	struct nfs4_stateowner *sop = stp->st_stateowner;
-	struct nfs4_callback *cb = &sop->so_client->cl_callback;
+	struct nfs4_cb_conn *cb = &sop->so_client->cl_cb_conn;
 	struct file_lock fl, *flp = &fl;
 	int status, flag = 0;
 
@@ -2617,7 +2617,7 @@ nfsd4_renew(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	renew_client(clp);
 	status = nfserr_cb_path_down;
 	if (!list_empty(&clp->cl_delegations)
-			&& !atomic_read(&clp->cl_callback.cb_set))
+			&& !atomic_read(&clp->cl_cb_conn.cb_set))
 		goto out;
 	status = nfs_ok;
 out:
diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index 8d882a3..cefb012 100644
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -88,7 +88,7 @@ struct nfs4_delegation {
 #define dl_fh           dl_recall.cbr_fh
 
 /* client delegation callback info */
-struct nfs4_callback {
+struct nfs4_cb_conn {
 	/* SETCLIENTID info */
 	u32                     cb_addr;
 	unsigned short          cb_port;
@@ -186,7 +186,7 @@ struct nfs4_client {
 	struct svc_cred		cl_cred; 	/* setclientid principal */
 	clientid_t		cl_clientid;	/* generated by server */
 	nfs4_verifier		cl_confirm;	/* generated by server */
-	struct nfs4_callback	cl_callback;    /* callback info */
+	struct nfs4_cb_conn	cl_cb_conn;     /* callback info */
 	atomic_t		cl_count;	/* ref count */
 	u32			cl_firststate;	/* recovery dir creation */
 
-- 
1.6.0.4

[PATCH] nfsd: quiet compile warning

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

Stephen Rothwell said:
"Today's linux-next build (powerpc ppc64_defconfig) produced this new
warning:

fs/nfsd/nfs4state.c: In function 'EXPIRED_STATEID':
fs/nfsd/nfs4state.c:2757: warning: comparison of distinct pointer types lacks a cast

Caused by commit 78155ed75f470710f2aecb3e75e3d97107ba8374 ("nfsd4:
distinguish expired from stale stateids")."

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
---
 fs/nfsd/nfs4state.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 74e822e..d24dd12 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2754,7 +2754,7 @@ EXPIRED_STATEID(stateid_t *stateid)
 {
 	if (time_before((unsigned long)boot_time,
 			((unsigned long)stateid->si_boot)) &&
-	    time_before((stateid->si_boot + lease_time), get_seconds())) {
+	    time_before((unsigned long)(stateid->si_boot + lease_time), get_seconds())) {
 		dprintk("NFSD: expired stateid (%08x/%08x/%08x/%08x)!\n",
 			stateid->si_boot, stateid->si_stateownerid,
 			stateid->si_fileid, stateid->si_generation);
-- 
1.6.0.4

[PATCH] nfsd4: setclientid_confirm callback-change fixes

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

This setclientid_confirm case should allow the client to change
callbacks, but it currently has a dummy implementation that just turns
off callbacks completely.  That dummy implementation isn't completely
correct either, though:

	- There's no need to remove any client recovery directory in
	  this case.
	- New clientid confirm verifiers should be generated (and
	  returned) in setclientid; there's no need to generate a new
	  one here.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
 fs/nfsd/nfs4state.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index d24dd12..7e1fcc3 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1688,8 +1688,6 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
 			/* XXX: We just turn off callbacks until we can handle
 			  * change request correctly. */
 			atomic_set(&conf->cl_callback.cb_set, 0);
-			gen_confirm(conf);
-			nfsd4_remove_clid_dir(unconf);
 			expire_client(unconf);
 			status = nfs_ok;
 
-- 
1.6.0.4

[PATCH] nfsd4: set shorter timeout

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

We tried to do something overly complicated with the callback rpc
timeouts here.  And they're wrong--the result is that by the time a
single callback times out, it's already too late to tell the client
(using the cb_path_down return to RENEW) that the callback is down.

Use a much shorter, simpler timeout.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
 fs/nfsd/nfs4callback.c |   11 +++++++----
 1 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 290289b..049f052 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -358,6 +358,11 @@ static struct rpc_program cb_program = {
 		.pipe_dir_name  = "/nfsd4_cb",
 };
 
+static int max_cb_time(void)
+{
+	return max(NFSD_LEASE_TIME/10, (time_t)1) * HZ;
+}
+
 /* Reference counting, callback cleanup, etc., all look racy as heck.
  * And why is cb_set an atomic? */
 
@@ -366,10 +371,8 @@ static struct rpc_clnt *setup_callback_client(struct nfs4_client *clp)
 	struct sockaddr_in	addr;
 	struct nfs4_callback    *cb = &clp->cl_callback;
 	struct rpc_timeout	timeparms = {
-		.to_initval	= (NFSD_LEASE_TIME/4) * HZ,
-		.to_retries	= 5,
-		.to_maxval	= (NFSD_LEASE_TIME/2) * HZ,
-		.to_exponential	= 1,
+		.to_initval	= max_cb_time(),
+		.to_retries	= 0,
 	};
 	struct rpc_create_args args = {
 		.protocol	= IPPROTO_TCP,
-- 
1.6.0.4

[PATCH] nfsd4: set cb_client inside setup_callback_client

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

This is just a minor code simplification.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
 fs/nfsd/nfs4callback.c |   26 ++++++++++++--------------
 1 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 049f052..4788d09 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -366,7 +366,7 @@ static int max_cb_time(void)
 /* Reference counting, callback cleanup, etc., all look racy as heck.
  * And why is cb_set an atomic? */
 
-static struct rpc_clnt *setup_callback_client(struct nfs4_client *clp)
+int setup_callback_client(struct nfs4_client *clp)
 {
 	struct sockaddr_in	addr;
 	struct nfs4_callback    *cb = &clp->cl_callback;
@@ -389,7 +389,7 @@ static struct rpc_clnt *setup_callback_client(struct nfs4_client *clp)
 	struct rpc_clnt *client;
 
 	if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
-		return ERR_PTR(-EINVAL);
+		return -EINVAL;
 
 	/* Initialize address */
 	memset(&addr, 0, sizeof(addr));
@@ -399,10 +399,13 @@ static struct rpc_clnt *setup_callback_client(struct nfs4_client *clp)
 
 	/* Create RPC client */
 	client = rpc_create(&args);
-	if (IS_ERR(client))
+	if (IS_ERR(client)) {
 		dprintk("NFSD: couldn't create callback client: %ld\n",
 			PTR_ERR(client));
-	return client;
+		return PTR_ERR(client);
+	}
+	cb->cb_client = client;
+	return 0;
 
 }
 
@@ -414,28 +417,23 @@ static int do_probe_callback(void *data)
 		.rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
 		.rpc_argp       = clp,
 	};
-	struct rpc_clnt *client;
 	int status;
 
-	client = setup_callback_client(clp);
-	if (IS_ERR(client)) {
-		status = PTR_ERR(client);
-		dprintk("NFSD: couldn't create callback client: %d\n",
-								status);
+	status = setup_callback_client(clp);
+	if (status)
 		goto out_err;
-	}
 
-	status = rpc_call_sync(client, &msg, RPC_TASK_SOFT);
+	status = rpc_call_sync(cb->cb_client, &msg, RPC_TASK_SOFT);
 
 	if (status)
 		goto out_release_client;
 
-	cb->cb_client = client;
 	atomic_set(&cb->cb_set, 1);
 	put_nfs4_client(clp);
 	return 0;
 out_release_client:
-	rpc_shutdown_client(client);
+	rpc_shutdown_client(cb->cb_client);
+	cb->cb_client = NULL;
 out_err:
 	dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
 		(int)clp->cl_name.len, clp->cl_name.data, status);
-- 
1.6.0.4

[PATCH] nfsd4: create rpc callback client from server thread

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

The code is a little simpler, and it should be easier to avoid races, if
we just do all rpc client creation/destruction from nfsd or laundromat
threads and do only the rpc calls themselves asynchronously.  The rpc
creation doesn't involve any significant waiting (it doesn't call the
client, for example), so there's no reason not to do this.

Also don't bother destroying the client on failure of the rpc null
probe.  We may want to retry the probe later anyway.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
 fs/nfsd/nfs4callback.c |   31 ++++++++++++++++---------------
 1 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 4788d09..711c628 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -409,6 +409,12 @@ int setup_callback_client(struct nfs4_client *clp)
 
 }
 
+static void warn_no_callback_path(struct nfs4_client *clp, int reason)
+{
+	dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
+		(int)clp->cl_name.len, clp->cl_name.data, reason);
+}
+
 static int do_probe_callback(void *data)
 {
 	struct nfs4_client *clp = data;
@@ -419,24 +425,12 @@ static int do_probe_callback(void *data)
 	};
 	int status;
 
-	status = setup_callback_client(clp);
-	if (status)
-		goto out_err;
-
 	status = rpc_call_sync(cb->cb_client, &msg, RPC_TASK_SOFT);
-
 	if (status)
-		goto out_release_client;
+		warn_no_callback_path(clp, status);
+	else
+		atomic_set(&cb->cb_set, 1);
 
-	atomic_set(&cb->cb_set, 1);
-	put_nfs4_client(clp);
-	return 0;
-out_release_client:
-	rpc_shutdown_client(cb->cb_client);
-	cb->cb_client = NULL;
-out_err:
-	dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
-		(int)clp->cl_name.len, clp->cl_name.data, status);
 	put_nfs4_client(clp);
 	return 0;
 }
@@ -448,9 +442,16 @@ void
 nfsd4_probe_callback(struct nfs4_client *clp)
 {
 	struct task_struct *t;
+	int status;
 
 	BUG_ON(atomic_read(&clp->cl_callback.cb_set));
 
+	status = setup_callback_client(clp);
+	if (status) {
+		warn_no_callback_path(clp, status);
+		return;
+	}
+
 	/* the task holds a reference to the nfs4_client struct */
 	atomic_inc(&clp->cl_count);
 
-- 
1.6.0.4

[PATCH] nfsd4: lookup up callback cred only once

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

Lookup the callback cred once and then use it for all subsequent
callbacks.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
 fs/nfsd/nfs4callback.c     |   26 ++++++++++++++++++++++++++
 fs/nfsd/nfs4state.c        |    4 ++++
 include/linux/nfsd/state.h |    1 +
 3 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 711c628..cc10ed3 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -415,6 +415,22 @@ static void warn_no_callback_path(struct nfs4_client *clp, int reason)
 		(int)clp->cl_name.len, clp->cl_name.data, reason);
 }
 
+static struct rpc_cred *lookup_cb_cred(struct nfs4_callback *cb)
+{
+	struct auth_cred acred = {
+		.machine_cred = 1
+	};
+
+	/*
+	 * Note in the gss case this doesn't actually have to wait for a
+	 * gss upcall (or any calls to the client); this just creates a
+	 * non-uptodate cred which the rpc state machine will fill in with
+	 * a refresh_upcall later.
+	 */
+	return rpcauth_lookup_credcache(cb->cb_client->cl_auth, &acred,
+							RPCAUTH_LOOKUP_NEW);
+}
+
 static int do_probe_callback(void *data)
 {
 	struct nfs4_client *clp = data;
@@ -423,9 +439,18 @@ static int do_probe_callback(void *data)
 		.rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
 		.rpc_argp       = clp,
 	};
+	struct rpc_cred *cred;
 	int status;
 
+	cred = lookup_cb_cred(cb);
+	if (IS_ERR(cred)) {
+		status = PTR_ERR(cred);
+		goto out;
+	}
+	cb->cb_cred = cred;
+	msg.rpc_cred = cb->cb_cred;
 	status = rpc_call_sync(cb->cb_client, &msg, RPC_TASK_SOFT);
+out:
 	if (status)
 		warn_no_callback_path(clp, status);
 	else
@@ -475,6 +500,7 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
 	struct rpc_message msg = {
 		.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
 		.rpc_argp = cbr,
+		.rpc_cred = clp->cl_callback.cb_cred
 	};
 	int retries = 1;
 	int status = 0;
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 7e1fcc3..b205c7d 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -643,6 +643,10 @@ shutdown_callback_client(struct nfs4_client *clp)
 		clp->cl_callback.cb_client = NULL;
 		rpc_shutdown_client(clnt);
 	}
+	if (clp->cl_callback.cb_cred) {
+		put_rpccred(clp->cl_callback.cb_cred);
+		clp->cl_callback.cb_cred = NULL;
+	}
 }
 
 static inline void
diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index 4d61c87..8d882a3 100644
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -97,6 +97,7 @@ struct nfs4_callback {
 	/* RPC client info */
 	atomic_t		cb_set;     /* successful CB_NULL call */
 	struct rpc_clnt *       cb_client;
+	struct rpc_cred	*	cb_cred;
 };
 
 /* Maximum number of slots per session. 128 is useful for long haul TCP */
-- 
1.6.0.4

[PATCH] nfsd4: replace callback thread by asynchronous rpc

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

We don't really need a synchronous rpc, and moving to an asynchronous
rpc allows us to do without this extra kthread.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
 fs/nfsd/nfs4callback.c |   38 ++++++++++++++++++++++----------------
 1 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index cc10ed3..0aaf68b 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -415,6 +415,21 @@ static void warn_no_callback_path(struct nfs4_client *clp, int reason)
 		(int)clp->cl_name.len, clp->cl_name.data, reason);
 }
 
+static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_client *clp = calldata;
+
+	if (task->tk_status)
+		warn_no_callback_path(clp, task->tk_status);
+	else
+		atomic_set(&clp->cl_callback.cb_set, 1);
+	put_nfs4_client(clp);
+}
+
+static const struct rpc_call_ops nfsd4_cb_probe_ops = {
+	.rpc_call_done = nfsd4_cb_probe_done,
+};
+
 static struct rpc_cred *lookup_cb_cred(struct nfs4_callback *cb)
 {
 	struct auth_cred acred = {
@@ -431,9 +446,8 @@ static struct rpc_cred *lookup_cb_cred(struct nfs4_callback *cb)
 							RPCAUTH_LOOKUP_NEW);
 }
 
-static int do_probe_callback(void *data)
+void do_probe_callback(struct nfs4_client *clp)
 {
-	struct nfs4_client *clp = data;
 	struct nfs4_callback    *cb = &clp->cl_callback;
 	struct rpc_message msg = {
 		.rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
@@ -449,15 +463,13 @@ static int do_probe_callback(void *data)
 	}
 	cb->cb_cred = cred;
 	msg.rpc_cred = cb->cb_cred;
-	status = rpc_call_sync(cb->cb_client, &msg, RPC_TASK_SOFT);
+	status = rpc_call_async(cb->cb_client, &msg, RPC_TASK_SOFT,
+				&nfsd4_cb_probe_ops, (void *)clp);
 out:
-	if (status)
+	if (status) {
 		warn_no_callback_path(clp, status);
-	else
-		atomic_set(&cb->cb_set, 1);
-
-	put_nfs4_client(clp);
-	return 0;
+		put_nfs4_client(clp);
+	}
 }
 
 /*
@@ -466,7 +478,6 @@ out:
 void
 nfsd4_probe_callback(struct nfs4_client *clp)
 {
-	struct task_struct *t;
 	int status;
 
 	BUG_ON(atomic_read(&clp->cl_callback.cb_set));
@@ -480,12 +491,7 @@ nfsd4_probe_callback(struct nfs4_client *clp)
 	/* the task holds a reference to the nfs4_client struct */
 	atomic_inc(&clp->cl_count);
 
-	t = kthread_run(do_probe_callback, clp, "nfs4_cb_probe");
-
-	if (IS_ERR(t))
-		atomic_dec(&clp->cl_count);
-
-	return;
+	do_probe_callback(clp);
 }
 
 /*
-- 
1.6.0.4

[PATCH] nfsd4: rename callback struct to cb_conn

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

I want to use the name for a struct that actually does represent a
single callback.

(Actually, I've never been sure it helps to a separate struct for the
callback information.  Some day maybe those fields could just be dumped
into struct nfs4_client.  I don't know.)

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
 fs/nfsd/nfs4callback.c     |   16 ++++++++--------
 fs/nfsd/nfs4state.c        |   22 +++++++++++-----------
 include/linux/nfsd/state.h |    4 ++--
 3 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 0aaf68b..ed860d7 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -369,7 +369,7 @@ static int max_cb_time(void)
 int setup_callback_client(struct nfs4_client *clp)
 {
 	struct sockaddr_in	addr;
-	struct nfs4_callback    *cb = &clp->cl_callback;
+	struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
 	struct rpc_timeout	timeparms = {
 		.to_initval	= max_cb_time(),
 		.to_retries	= 0,
@@ -422,7 +422,7 @@ static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
 	if (task->tk_status)
 		warn_no_callback_path(clp, task->tk_status);
 	else
-		atomic_set(&clp->cl_callback.cb_set, 1);
+		atomic_set(&clp->cl_cb_conn.cb_set, 1);
 	put_nfs4_client(clp);
 }
 
@@ -430,7 +430,7 @@ static const struct rpc_call_ops nfsd4_cb_probe_ops = {
 	.rpc_call_done = nfsd4_cb_probe_done,
 };
 
-static struct rpc_cred *lookup_cb_cred(struct nfs4_callback *cb)
+static struct rpc_cred *lookup_cb_cred(struct nfs4_cb_conn *cb)
 {
 	struct auth_cred acred = {
 		.machine_cred = 1
@@ -448,7 +448,7 @@ static struct rpc_cred *lookup_cb_cred(struct nfs4_callback *cb)
 
 void do_probe_callback(struct nfs4_client *clp)
 {
-	struct nfs4_callback    *cb = &clp->cl_callback;
+	struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
 	struct rpc_message msg = {
 		.rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
 		.rpc_argp       = clp,
@@ -480,7 +480,7 @@ nfsd4_probe_callback(struct nfs4_client *clp)
 {
 	int status;
 
-	BUG_ON(atomic_read(&clp->cl_callback.cb_set));
+	BUG_ON(atomic_read(&clp->cl_cb_conn.cb_set));
 
 	status = setup_callback_client(clp);
 	if (status) {
@@ -501,12 +501,12 @@ void
 nfsd4_cb_recall(struct nfs4_delegation *dp)
 {
 	struct nfs4_client *clp = dp->dl_client;
-	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
+	struct rpc_clnt *clnt = clp->cl_cb_conn.cb_client;
 	struct nfs4_cb_recall *cbr = &dp->dl_recall;
 	struct rpc_message msg = {
 		.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
 		.rpc_argp = cbr,
-		.rpc_cred = clp->cl_callback.cb_cred
+		.rpc_cred = clp->cl_cb_conn.cb_cred
 	};
 	int retries = 1;
 	int status = 0;
@@ -519,7 +519,7 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
 		switch (status) {
 			case -EIO:
 				/* Network partition? */
-				atomic_set(&clp->cl_callback.cb_set, 0);
+				atomic_set(&clp->cl_cb_conn.cb_set, 0);
 			case -EBADHANDLE:
 			case -NFS4ERR_BAD_STATEID:
 				/* Race: client probably got cb_recall
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index b205c7d..d7b5e6b 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -182,7 +182,7 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_stateid *stp, struct svc_f
 {
 	struct nfs4_delegation *dp;
 	struct nfs4_file *fp = stp->st_file;
-	struct nfs4_callback *cb = &stp->st_stateowner->so_client->cl_callback;
+	struct nfs4_cb_conn *cb = &stp->st_stateowner->so_client->cl_cb_conn;
 
 	dprintk("NFSD alloc_init_deleg\n");
 	if (fp->fi_had_conflict)
@@ -633,19 +633,19 @@ static struct nfs4_client *alloc_client(struct xdr_netobj name)
 static void
 shutdown_callback_client(struct nfs4_client *clp)
 {
-	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
+	struct rpc_clnt *clnt = clp->cl_cb_conn.cb_client;
 
 	if (clnt) {
 		/*
 		 * Callback threads take a reference on the client, so there
 		 * should be no outstanding callbacks at this point.
 		 */
-		clp->cl_callback.cb_client = NULL;
+		clp->cl_cb_conn.cb_client = NULL;
 		rpc_shutdown_client(clnt);
 	}
-	if (clp->cl_callback.cb_cred) {
-		put_rpccred(clp->cl_callback.cb_cred);
-		clp->cl_callback.cb_cred = NULL;
+	if (clp->cl_cb_conn.cb_cred) {
+		put_rpccred(clp->cl_cb_conn.cb_cred);
+		clp->cl_cb_conn.cb_cred = NULL;
 	}
 }
 
@@ -719,7 +719,7 @@ static struct nfs4_client *create_client(struct xdr_netobj name, char *recdir)
 		return NULL;
 	memcpy(clp->cl_recdir, recdir, HEXDIR_LEN);
 	atomic_set(&clp->cl_count, 1);
-	atomic_set(&clp->cl_callback.cb_set, 0);
+	atomic_set(&clp->cl_cb_conn.cb_set, 0);
 	INIT_LIST_HEAD(&clp->cl_idhash);
 	INIT_LIST_HEAD(&clp->cl_strhash);
 	INIT_LIST_HEAD(&clp->cl_openowners);
@@ -971,7 +971,7 @@ parse_ipv4(unsigned int addr_len, char *addr_val, unsigned int *cbaddrp, unsigne
 static void
 gen_callback(struct nfs4_client *clp, struct nfsd4_setclientid *se)
 {
-	struct nfs4_callback *cb = &clp->cl_callback;
+	struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
 
 	/* Currently, we only support tcp for the callback channel */
 	if ((se->se_callback_netid_len != 3) || memcmp((char *)se->se_callback_netid_val, "tcp", 3))
@@ -1691,7 +1691,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
 		else {
 			/* XXX: We just turn off callbacks until we can handle
 			  * change request correctly. */
-			atomic_set(&conf->cl_callback.cb_set, 0);
+			atomic_set(&conf->cl_cb_conn.cb_set, 0);
 			expire_client(unconf);
 			status = nfs_ok;
 
@@ -2425,7 +2425,7 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_sta
 {
 	struct nfs4_delegation *dp;
 	struct nfs4_stateowner *sop = stp->st_stateowner;
-	struct nfs4_callback *cb = &sop->so_client->cl_callback;
+	struct nfs4_cb_conn *cb = &sop->so_client->cl_cb_conn;
 	struct file_lock fl, *flp = &fl;
 	int status, flag = 0;
 
@@ -2617,7 +2617,7 @@ nfsd4_renew(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	renew_client(clp);
 	status = nfserr_cb_path_down;
 	if (!list_empty(&clp->cl_delegations)
-			&& !atomic_read(&clp->cl_callback.cb_set))
+			&& !atomic_read(&clp->cl_cb_conn.cb_set))
 		goto out;
 	status = nfs_ok;
 out:
diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index 8d882a3..563c367 100644
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -88,7 +88,7 @@ struct nfs4_delegation {
 #define dl_fh           dl_recall.cbr_fh
 
 /* client delegation callback info */
-struct nfs4_callback {
+struct nfs4_cb_conn {
 	/* SETCLIENTID info */
 	u32                     cb_addr;
 	unsigned short          cb_port;
@@ -186,7 +186,7 @@ struct nfs4_client {
 	struct svc_cred		cl_cred; 	/* setclientid principal */
 	clientid_t		cl_clientid;	/* generated by server */
 	nfs4_verifier		cl_confirm;	/* generated by server */
-	struct nfs4_callback	cl_callback;    /* callback info */
+	struct nfs4_cb_conn	cl_cb_conn;     /* callback info */
 	atomic_t		cl_count;	/* ref count */
 	u32			cl_firststate;	/* recovery dir creation */
 
-- 
1.6.0.4

[PATCH] nfsd4: eliminate struct nfs4_cb_recall

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

The nfs4_cb_recall struct is used only in nfs4_delegation, so its
pointer to the containing delegation is unnecessary--we could just use
container_of().

But there's no real reason to have this a separate struct at all--just
move these fields to nfs4_delegation.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
 fs/nfsd/nfs4callback.c     |   24 +++++++++++-------------
 fs/nfsd/nfs4state.c        |    5 ++---
 include/linux/nfsd/state.h |   18 +++++-------------
 3 files changed, 18 insertions(+), 29 deletions(-)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index ed860d7..2509305 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -215,18 +215,18 @@ encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
 }
 
 static int
-encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
+encode_cb_recall(struct xdr_stream *xdr, struct nfs4_delegation *dp)
 {
 	__be32 *p;
-	int len = cb_rec->cbr_fh.fh_size;
+	int len = dp->dl_fh.fh_size;
 
-	RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
+	RESERVE_SPACE(12+sizeof(dp->dl_stateid) + len);
 	WRITE32(OP_CB_RECALL);
-	WRITE32(cb_rec->cbr_stateid.si_generation);
-	WRITEMEM(&cb_rec->cbr_stateid.si_opaque, sizeof(stateid_opaque_t));
-	WRITE32(cb_rec->cbr_trunc);
+	WRITE32(dp->dl_stateid.si_generation);
+	WRITEMEM(&dp->dl_stateid.si_opaque, sizeof(stateid_opaque_t));
+	WRITE32(dp->dl_trunc);
 	WRITE32(len);
-	WRITEMEM(&cb_rec->cbr_fh.fh_base, len);
+	WRITEMEM(&dp->dl_fh.fh_base, len);
 	return 0;
 }
 
@@ -241,11 +241,11 @@ nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
 }
 
 static int
-nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_cb_recall *args)
+nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_delegation *args)
 {
 	struct xdr_stream xdr;
 	struct nfs4_cb_compound_hdr hdr = {
-		.ident = args->cbr_ident,
+		.ident = args->dl_ident,
 		.nops   = 1,
 	};
 
@@ -502,17 +502,15 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
 {
 	struct nfs4_client *clp = dp->dl_client;
 	struct rpc_clnt *clnt = clp->cl_cb_conn.cb_client;
-	struct nfs4_cb_recall *cbr = &dp->dl_recall;
 	struct rpc_message msg = {
 		.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
-		.rpc_argp = cbr,
+		.rpc_argp = dp,
 		.rpc_cred = clp->cl_cb_conn.cb_cred
 	};
 	int retries = 1;
 	int status = 0;
 
-	cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
-	cbr->cbr_dp = dp;
+	dp->dl_trunc = 0; /* XXX need to implement truncate optimization */
 
 	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
 	while (retries--) {
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index d7b5e6b..3e5345e 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -203,9 +203,8 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_stateid *stp, struct svc_f
 	get_file(stp->st_vfs_file);
 	dp->dl_vfs_file = stp->st_vfs_file;
 	dp->dl_type = type;
-	dp->dl_recall.cbr_dp = NULL;
-	dp->dl_recall.cbr_ident = cb->cb_ident;
-	dp->dl_recall.cbr_trunc = 0;
+	dp->dl_ident = cb->cb_ident;
+	dp->dl_trunc = 0;
 	dp->dl_stateid.si_boot = get_seconds();
 	dp->dl_stateid.si_stateownerid = current_delegid++;
 	dp->dl_stateid.si_fileid = 0;
diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index 563c367..233b60d 100644
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -61,15 +61,6 @@ typedef struct {
 #define si_stateownerid   si_opaque.so_stateownerid
 #define si_fileid         si_opaque.so_fileid
 
-
-struct nfs4_cb_recall {
-	u32			cbr_ident;
-	int			cbr_trunc;
-	stateid_t		cbr_stateid;
-	struct knfsd_fh		cbr_fh;
-	struct nfs4_delegation	*cbr_dp;
-};
-
 struct nfs4_delegation {
 	struct list_head	dl_perfile;
 	struct list_head	dl_perclnt;
@@ -81,12 +72,13 @@ struct nfs4_delegation {
 	struct file		*dl_vfs_file;
 	u32			dl_type;
 	time_t			dl_time;
-	struct nfs4_cb_recall	dl_recall;
+/* For recall: */
+	u32			dl_ident;
+	int			dl_trunc;
+	stateid_t		dl_stateid;
+	struct knfsd_fh		dl_fh;
 };
 
-#define dl_stateid      dl_recall.cbr_stateid
-#define dl_fh           dl_recall.cbr_fh
-
 /* client delegation callback info */
 struct nfs4_cb_conn {
 	/* SETCLIENTID info */
-- 
1.6.0.4

[PATCH] nfsd4: remove unused dl_trunc

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

There's no point in keeping this field around--it's always zero.

(Background: the protocol allows you to tell the client that the file is
about to be truncated, as an optimization to save the client from
writing back dirty pages that will just be discarded.  We don't
implement this hint.  If we do some day, adding this field back in will
be the least of the work involved.)

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
 fs/nfsd/nfs4callback.c     |    4 +---
 fs/nfsd/nfs4state.c        |    1 -
 include/linux/nfsd/state.h |    1 -
 3 files changed, 1 insertions(+), 5 deletions(-)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 2509305..0420b5e 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -224,7 +224,7 @@ encode_cb_recall(struct xdr_stream *xdr, struct nfs4_delegation *dp)
 	WRITE32(OP_CB_RECALL);
 	WRITE32(dp->dl_stateid.si_generation);
 	WRITEMEM(&dp->dl_stateid.si_opaque, sizeof(stateid_opaque_t));
-	WRITE32(dp->dl_trunc);
+	WRITE32(0); /* truncate optimization not implemented */
 	WRITE32(len);
 	WRITEMEM(&dp->dl_fh.fh_base, len);
 	return 0;
@@ -510,8 +510,6 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
 	int retries = 1;
 	int status = 0;
 
-	dp->dl_trunc = 0; /* XXX need to implement truncate optimization */
-
 	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
 	while (retries--) {
 		switch (status) {
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 3e5345e..cbb16e1 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -204,7 +204,6 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_stateid *stp, struct svc_f
 	dp->dl_vfs_file = stp->st_vfs_file;
 	dp->dl_type = type;
 	dp->dl_ident = cb->cb_ident;
-	dp->dl_trunc = 0;
 	dp->dl_stateid.si_boot = get_seconds();
 	dp->dl_stateid.si_stateownerid = current_delegid++;
 	dp->dl_stateid.si_fileid = 0;
diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index 233b60d..346b603 100644
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -74,7 +74,6 @@ struct nfs4_delegation {
 	time_t			dl_time;
 /* For recall: */
 	u32			dl_ident;
-	int			dl_trunc;
 	stateid_t		dl_stateid;
 	struct knfsd_fh		dl_fh;
 };
-- 
1.6.0.4

[PATCH] nfsd4: track recall retries in nfs4_delegation

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

Move this out of a local variable into the nfs4_delegation object in
preparation for making this an async rpc call (at which point we'll need
any state like this in a common object that's preserved across function
calls).

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
 fs/nfsd/nfs4callback.c     |    4 ++--
 include/linux/nfsd/state.h |    1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 0420b5e..b88b207 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -507,11 +507,11 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
 		.rpc_argp = dp,
 		.rpc_cred = clp->cl_cb_conn.cb_cred
 	};
-	int retries = 1;
 	int status = 0;
 
+	dp->dl_retries = 1;
 	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
-	while (retries--) {
+	while (dp->dl_retries--) {
 		switch (status) {
 			case -EIO:
 				/* Network partition? */
diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index 346b603..c0c4921 100644
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -76,6 +76,7 @@ struct nfs4_delegation {
 	u32			dl_ident;
 	stateid_t		dl_stateid;
 	struct knfsd_fh		dl_fh;
+	int			dl_retries;
 };
 
 /* client delegation callback info */
-- 
1.6.0.4

[PATCH] nfsd4: make recall callback an asynchronous rpc

[J. Bruce Fields]

From: J. Bruce Fields <bfields@citi.umich.edu>

As with the probe, this removes the need for another kthread.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
 fs/nfsd/nfs4callback.c |   74 +++++++++++++++++++++++++++++++----------------
 fs/nfsd/nfs4state.c    |   28 ++----------------
 2 files changed, 52 insertions(+), 50 deletions(-)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index b88b207..753184e 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -494,6 +494,49 @@ nfsd4_probe_callback(struct nfs4_client *clp)
 	do_probe_callback(clp);
 }
 
+static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_delegation *dp = calldata;
+	struct nfs4_client *clp = dp->dl_client;
+
+	switch (task->tk_status) {
+		case -EIO:
+			/* Network partition? */
+			atomic_set(&clp->cl_cb_conn.cb_set, 0);
+			warn_no_callback_path(clp, task->tk_status);
+		case -EBADHANDLE:
+		case -NFS4ERR_BAD_STATEID:
+			/* Race: client probably got cb_recall
+			 * before open reply granting delegation */
+			break;
+		default:
+			/* success, or error we can't handle */
+			return;
+	}
+	if (dp->dl_retries--) {
+		rpc_delay(task, 2*HZ);
+		task->tk_status = 0;
+		rpc_restart_call(task);
+	} else {
+		atomic_set(&clp->cl_cb_conn.cb_set, 0);
+		warn_no_callback_path(clp, task->tk_status);
+	}
+}
+
+static void nfsd4_cb_recall_release(void *calldata)
+{
+	struct nfs4_delegation *dp = calldata;
+	struct nfs4_client *clp = dp->dl_client;
+
+	nfs4_put_delegation(dp);
+	put_nfs4_client(clp);
+}
+
+static const struct rpc_call_ops nfsd4_cb_recall_ops = {
+	.rpc_call_done = nfsd4_cb_recall_done,
+	.rpc_release = nfsd4_cb_recall_release,
+};
+
 /*
  * called with dp->dl_count inc'ed.
  */
@@ -507,32 +550,13 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
 		.rpc_argp = dp,
 		.rpc_cred = clp->cl_cb_conn.cb_cred
 	};
-	int status = 0;
+	int status;
 
 	dp->dl_retries = 1;
-	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
-	while (dp->dl_retries--) {
-		switch (status) {
-			case -EIO:
-				/* Network partition? */
-				atomic_set(&clp->cl_cb_conn.cb_set, 0);
-			case -EBADHANDLE:
-			case -NFS4ERR_BAD_STATEID:
-				/* Race: client probably got cb_recall
-				 * before open reply granting delegation */
-				break;
-			default:
-				goto out_put_cred;
-		}
-		ssleep(2);
-		status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
+	status = rpc_call_async(clnt, &msg, RPC_TASK_SOFT,
+				&nfsd4_cb_recall_ops, dp);
+	if (status) {
+		put_nfs4_client(clp);
+		nfs4_put_delegation(dp);
 	}
-out_put_cred:
-	/*
-	 * Success or failure, now we're either waiting for lease expiration
-	 * or deleg_return.
-	 */
-	put_nfs4_client(clp);
-	nfs4_put_delegation(dp);
-	return;
 }
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index cbb16e1..a4bdf25 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2060,19 +2060,6 @@ nfs4_file_downgrade(struct file *filp, unsigned int share_access)
 }
 
 /*
- * Recall a delegation
- */
-static int
-do_recall(void *__dp)
-{
-	struct nfs4_delegation *dp = __dp;
-
-	dp->dl_file->fi_had_conflict = true;
-	nfsd4_cb_recall(dp);
-	return 0;
-}
-
-/*
  * Spawn a thread to perform a recall on the delegation represented
  * by the lease (file_lock)
  *
@@ -2083,8 +2070,7 @@ do_recall(void *__dp)
 static
 void nfsd_break_deleg_cb(struct file_lock *fl)
 {
-	struct nfs4_delegation *dp=  (struct nfs4_delegation *)fl->fl_owner;
-	struct task_struct *t;
+	struct nfs4_delegation *dp = (struct nfs4_delegation *)fl->fl_owner;
 
 	dprintk("NFSD nfsd_break_deleg_cb: dp %p fl %p\n",dp,fl);
 	if (!dp)
@@ -2112,16 +2098,8 @@ void nfsd_break_deleg_cb(struct file_lock *fl)
 	 */
 	fl->fl_break_time = 0;
 
-	t = kthread_run(do_recall, dp, "%s", "nfs4_cb_recall");
-	if (IS_ERR(t)) {
-		struct nfs4_client *clp = dp->dl_client;
-
-		printk(KERN_INFO "NFSD: Callback thread failed for "
-			"for client (clientid %08x/%08x)\n",
-			clp->cl_clientid.cl_boot, clp->cl_clientid.cl_id);
-		put_nfs4_client(dp->dl_client);
-		nfs4_put_delegation(dp);
-	}
+	dp->dl_file->fi_had_conflict = true;
+	nfsd4_cb_recall(dp);
 }
 
 /*
-- 
1.6.0.4