/*
- * linux/fs/nfsd/nfs4callback.c
- *
* Copyright (c) 2001 The Regents of the University of Michigan.
* All rights reserved.
*
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
-#include <linux/module.h>
-#include <linux/list.h>
-#include <linux/inet.h>
-#include <linux/errno.h>
-#include <linux/delay.h>
-#include <linux/sched.h>
-#include <linux/kthread.h>
-#include <linux/sunrpc/xdr.h>
-#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/clnt.h>
-#include <linux/nfsd/nfsd.h>
-#include <linux/nfsd/state.h>
-#include <linux/sunrpc/sched.h>
-#include <linux/nfs4.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <linux/slab.h>
+#include "nfsd.h"
+#include "state.h"
#define NFSDDBG_FACILITY NFSDDBG_PROC
#define NFSPROC4_CB_NULL 0
#define NFSPROC4_CB_COMPOUND 1
+#define NFS4_STATEID_SIZE 16
/* Index of predefined Linux callback client operations */
enum {
NFSPROC4_CLNT_CB_NULL = 0,
NFSPROC4_CLNT_CB_RECALL,
+ NFSPROC4_CLNT_CB_SEQUENCE,
};
enum nfs_cb_opnum4 {
OP_CB_RECALL = 4,
+ OP_CB_SEQUENCE = 11,
};
#define NFS4_MAXTAGLEN 20
#define NFS4_dec_cb_null_sz 0
#define cb_compound_enc_hdr_sz 4
#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
+#define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2)
+#define cb_sequence_enc_sz (sessionid_sz + 4 + \
+ 1 /* no referring calls list yet */)
+#define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4)
+
#define op_enc_sz 1
#define op_dec_sz 2
#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
+ cb_sequence_enc_sz + \
1 + enc_stateid_sz + \
enc_nfs4_fh_sz)
#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
+ cb_sequence_dec_sz + \
op_dec_sz)
/*
} while (0)
struct nfs4_cb_compound_hdr {
- int status;
- u32 ident;
+ /* args */
+ u32 ident; /* minorversion 0 only */
u32 nops;
__be32 *nops_p;
u32 minorversion;
+ /* res */
+ int status;
u32 taglen;
char *tag;
};
hdr->nops++;
}
+static void
+encode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *args,
+ struct nfs4_cb_compound_hdr *hdr)
+{
+ __be32 *p;
+
+ if (hdr->minorversion == 0)
+ return;
+
+ RESERVE_SPACE(1 + NFS4_MAX_SESSIONID_LEN + 20);
+
+ WRITE32(OP_CB_SEQUENCE);
+ WRITEMEM(args->cbs_clp->cl_sessionid.data, NFS4_MAX_SESSIONID_LEN);
+ WRITE32(args->cbs_clp->cl_cb_seq_nr);
+ WRITE32(0); /* slotid, always 0 */
+ WRITE32(0); /* highest slotid always 0 */
+ WRITE32(0); /* cachethis always 0 */
+ WRITE32(0); /* FIXME: support referring_call_lists */
+ hdr->nops++;
+}
+
static int
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_delegation *args)
+nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p,
+ struct nfs4_rpc_args *rpc_args)
{
struct xdr_stream xdr;
+ struct nfs4_delegation *args = rpc_args->args_op;
struct nfs4_cb_compound_hdr hdr = {
.ident = args->dl_ident,
+ .minorversion = rpc_args->args_seq.cbs_minorversion,
};
xdr_init_encode(&xdr, &req->rq_snd_buf, p);
encode_cb_compound_hdr(&xdr, &hdr);
+ encode_cb_sequence(&xdr, &rpc_args->args_seq, &hdr);
encode_cb_recall(&xdr, args, &hdr);
encode_cb_nops(&hdr);
return 0;
return 0;
}
+/*
+ * Our current back channel implmentation supports a single backchannel
+ * with a single slot.
+ */
+static int
+decode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *res,
+ struct rpc_rqst *rqstp)
+{
+ struct nfs4_sessionid id;
+ int status;
+ u32 dummy;
+ __be32 *p;
+
+ if (res->cbs_minorversion == 0)
+ return 0;
+
+ status = decode_cb_op_hdr(xdr, OP_CB_SEQUENCE);
+ if (status)
+ return status;
+
+ /*
+ * If the server returns different values for sessionID, slotID or
+ * sequence number, the server is looney tunes.
+ */
+ status = -ESERVERFAULT;
+
+ READ_BUF(NFS4_MAX_SESSIONID_LEN + 16);
+ memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
+ p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
+ if (memcmp(id.data, res->cbs_clp->cl_sessionid.data,
+ NFS4_MAX_SESSIONID_LEN)) {
+ dprintk("%s Invalid session id\n", __func__);
+ goto out;
+ }
+ READ32(dummy);
+ if (dummy != res->cbs_clp->cl_cb_seq_nr) {
+ dprintk("%s Invalid sequence number\n", __func__);
+ goto out;
+ }
+ READ32(dummy); /* slotid must be 0 */
+ if (dummy != 0) {
+ dprintk("%s Invalid slotid\n", __func__);
+ goto out;
+ }
+ /* FIXME: process highest slotid and target highest slotid */
+ status = 0;
+out:
+ return status;
+}
+
+
static int
nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
{
}
static int
-nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p)
+nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p,
+ struct nfsd4_cb_sequence *seq)
{
struct xdr_stream xdr;
struct nfs4_cb_compound_hdr hdr;
status = decode_cb_compound_hdr(&xdr, &hdr);
if (status)
goto out;
+ if (seq) {
+ status = decode_cb_sequence(&xdr, seq, rqstp);
+ if (status)
+ goto out;
+ }
status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
out:
return status;
};
static struct rpc_version nfs_cb_version4 = {
+/*
+ * Note on the callback rpc program version number: despite language in rfc
+ * 5661 section 18.36.3 requiring servers to use 4 in this field, the
+ * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
+ * in practice that appears to be what implementations use. The section
+ * 18.36.3 language is expected to be fixed in an erratum.
+ */
.number = 1,
.nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
.procs = nfs4_cb_procedures
};
static struct rpc_version * nfs_cb_version[] = {
- NULL,
&nfs_cb_version4,
};
static int max_cb_time(void)
{
- return max(NFSD_LEASE_TIME/10, (time_t)1) * HZ;
+ return max(nfsd4_lease/10, (time_t)1) * HZ;
}
/* Reference counting, callback cleanup, etc., all look racy as heck.
- * And why is cb_set an atomic? */
+ * And why is cl_cb_set an atomic? */
-int setup_callback_client(struct nfs4_client *clp)
+int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *cb)
{
- struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
struct rpc_timeout timeparms = {
.to_initval = max_cb_time(),
.to_retries = 0,
};
struct rpc_create_args args = {
- .protocol = IPPROTO_TCP,
+ .protocol = XPRT_TRANSPORT_TCP,
.address = (struct sockaddr *) &cb->cb_addr,
.addrsize = cb->cb_addrlen,
.timeout = &timeparms,
.program = &cb_program,
.prognumber = cb->cb_prog,
- .version = nfs_cb_version[1]->number,
+ .version = 0,
.authflavor = clp->cl_flavor,
.flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
.client_name = clp->cl_principal,
if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
return -EINVAL;
-
+ if (cb->cb_minorversion) {
+ args.bc_xprt = cb->cb_xprt;
+ args.protocol = XPRT_TRANSPORT_BC_TCP;
+ }
/* Create RPC client */
client = rpc_create(&args);
if (IS_ERR(client)) {
PTR_ERR(client));
return PTR_ERR(client);
}
- cb->cb_client = client;
+ nfsd4_set_callback_client(clp, client);
return 0;
}
if (task->tk_status)
warn_no_callback_path(clp, task->tk_status);
else
- atomic_set(&clp->cl_cb_conn.cb_set, 1);
- put_nfs4_client(clp);
+ atomic_set(&clp->cl_cb_set, 1);
}
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_cb_conn *cb)
-{
- struct auth_cred acred = {
- .machine_cred = 1
- };
- struct rpc_auth *auth = cb->cb_client->cl_auth;
+static struct rpc_cred *callback_cred;
- /*
- * 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 auth->au_ops->lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
+int set_callback_cred(void)
+{
+ if (callback_cred)
+ return 0;
+ callback_cred = rpc_lookup_machine_cred();
+ if (!callback_cred)
+ return -ENOMEM;
+ return 0;
}
+
void do_probe_callback(struct nfs4_client *clp)
{
- 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,
+ .rpc_cred = callback_cred
};
- 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_async(cb->cb_client, &msg, RPC_TASK_SOFT,
+ status = rpc_call_async(clp->cl_cb_client, &msg,
+ RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
&nfsd4_cb_probe_ops, (void *)clp);
-out:
- if (status) {
+ if (status)
warn_no_callback_path(clp, status);
- put_nfs4_client(clp);
- }
}
/*
* Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
*/
-void
-nfsd4_probe_callback(struct nfs4_client *clp)
+void nfsd4_probe_callback(struct nfs4_client *clp, struct nfs4_cb_conn *cb)
{
int status;
- BUG_ON(atomic_read(&clp->cl_cb_conn.cb_set));
+ BUG_ON(atomic_read(&clp->cl_cb_set));
- status = setup_callback_client(clp);
+ status = setup_callback_client(clp, cb);
if (status) {
warn_no_callback_path(clp, status);
return;
}
+ do_probe_callback(clp);
+}
+
+/*
+ * There's currently a single callback channel slot.
+ * If the slot is available, then mark it busy. Otherwise, set the
+ * thread for sleeping on the callback RPC wait queue.
+ */
+static int nfsd41_cb_setup_sequence(struct nfs4_client *clp,
+ struct rpc_task *task)
+{
+ struct nfs4_rpc_args *args = task->tk_msg.rpc_argp;
+ u32 *ptr = (u32 *)clp->cl_sessionid.data;
+ int status = 0;
+
+ dprintk("%s: %u:%u:%u:%u\n", __func__,
+ ptr[0], ptr[1], ptr[2], ptr[3]);
+
+ if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
+ rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
+ dprintk("%s slot is busy\n", __func__);
+ status = -EAGAIN;
+ goto out;
+ }
- /* the task holds a reference to the nfs4_client struct */
- atomic_inc(&clp->cl_count);
+ /*
+ * We'll need the clp during XDR encoding and decoding,
+ * and the sequence during decoding to verify the reply
+ */
+ args->args_seq.cbs_clp = clp;
+ task->tk_msg.rpc_resp = &args->args_seq;
- do_probe_callback(clp);
+out:
+ dprintk("%s status=%d\n", __func__, status);
+ return status;
+}
+
+/*
+ * TODO: cb_sequence should support referring call lists, cachethis, multiple
+ * slots, and mark callback channel down on communication errors.
+ */
+static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
+{
+ struct nfs4_delegation *dp = calldata;
+ struct nfs4_client *clp = dp->dl_client;
+ struct nfs4_rpc_args *args = task->tk_msg.rpc_argp;
+ u32 minorversion = clp->cl_cb_conn.cb_minorversion;
+ int status = 0;
+
+ args->args_seq.cbs_minorversion = minorversion;
+ if (minorversion) {
+ status = nfsd41_cb_setup_sequence(clp, task);
+ if (status) {
+ if (status != -EAGAIN) {
+ /* terminate rpc task */
+ task->tk_status = status;
+ task->tk_action = NULL;
+ }
+ return;
+ }
+ }
+ rpc_call_start(task);
}
+static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
+{
+ struct nfs4_delegation *dp = calldata;
+ struct nfs4_client *clp = dp->dl_client;
+
+ dprintk("%s: minorversion=%d\n", __func__,
+ clp->cl_cb_conn.cb_minorversion);
+
+ if (clp->cl_cb_conn.cb_minorversion) {
+ /* No need for lock, access serialized in nfsd4_cb_prepare */
+ ++clp->cl_cb_seq_nr;
+ clear_bit(0, &clp->cl_cb_slot_busy);
+ rpc_wake_up_next(&clp->cl_cb_waitq);
+ dprintk("%s: freed slot, new seqid=%d\n", __func__,
+ clp->cl_cb_seq_nr);
+
+ /* We're done looking into the sequence information */
+ task->tk_msg.rpc_resp = NULL;
+ }
+}
+
+
static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
{
struct nfs4_delegation *dp = calldata;
struct nfs4_client *clp = dp->dl_client;
+ struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
+
+ nfsd4_cb_done(task, calldata);
+
+ if (current_rpc_client == NULL) {
+ /* We're shutting down; give up. */
+ /* XXX: err, or is it ok just to fall through
+ * and rpc_restart_call? */
+ return;
+ }
switch (task->tk_status) {
case -EIO:
/* Network partition? */
- atomic_set(&clp->cl_cb_conn.cb_set, 0);
+ atomic_set(&clp->cl_cb_set, 0);
warn_no_callback_path(clp, task->tk_status);
+ if (current_rpc_client != task->tk_client) {
+ /* queue a callback on the new connection: */
+ nfsd4_cb_recall(dp);
+ return;
+ }
case -EBADHANDLE:
case -NFS4ERR_BAD_STATEID:
/* Race: client probably got cb_recall
rpc_delay(task, 2*HZ);
task->tk_status = 0;
rpc_restart_call(task);
+ return;
} else {
- atomic_set(&clp->cl_cb_conn.cb_set, 0);
+ atomic_set(&clp->cl_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_prepare = nfsd4_cb_prepare,
.rpc_call_done = nfsd4_cb_recall_done,
.rpc_release = nfsd4_cb_recall_release,
};
+static struct workqueue_struct *callback_wq;
+
+int nfsd4_create_callback_queue(void)
+{
+ callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
+ if (!callback_wq)
+ return -ENOMEM;
+ return 0;
+}
+
+void nfsd4_destroy_callback_queue(void)
+{
+ destroy_workqueue(callback_wq);
+}
+
+/* must be called under the state lock */
+void nfsd4_set_callback_client(struct nfs4_client *clp, struct rpc_clnt *new)
+{
+ struct rpc_clnt *old = clp->cl_cb_client;
+
+ clp->cl_cb_client = new;
+ /*
+ * After this, any work that saw the old value of cl_cb_client will
+ * be gone:
+ */
+ flush_workqueue(callback_wq);
+ /* So we can safely shut it down: */
+ if (old)
+ rpc_shutdown_client(old);
+}
+
/*
* called with dp->dl_count inc'ed.
*/
-void
-nfsd4_cb_recall(struct nfs4_delegation *dp)
+static void _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 rpc_clnt *clnt = clp->cl_cb_client;
+ struct nfs4_rpc_args *args = &dp->dl_recall.cb_args;
struct rpc_message msg = {
.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
- .rpc_argp = dp,
- .rpc_cred = clp->cl_cb_conn.cb_cred
+ .rpc_cred = callback_cred
};
int status;
+ if (clnt == NULL)
+ return; /* Client is shutting down; give up. */
+
+ args->args_op = dp;
+ msg.rpc_argp = args;
dp->dl_retries = 1;
status = rpc_call_async(clnt, &msg, RPC_TASK_SOFT,
&nfsd4_cb_recall_ops, dp);
- if (status) {
- put_nfs4_client(clp);
+ if (status)
nfs4_put_delegation(dp);
- }
+}
+
+void nfsd4_do_callback_rpc(struct work_struct *w)
+{
+ /* XXX: for now, just send off delegation recall. */
+ /* In future, generalize to handle any sort of callback. */
+ struct nfsd4_callback *c = container_of(w, struct nfsd4_callback, cb_work);
+ struct nfs4_delegation *dp = container_of(c, struct nfs4_delegation, dl_recall);
+
+ _nfsd4_cb_recall(dp);
+}
+
+
+void nfsd4_cb_recall(struct nfs4_delegation *dp)
+{
+ queue_work(callback_wq, &dp->dl_recall.cb_work);
}