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-rw-r--r--fs/nfs/callback.c112
-rw-r--r--fs/nfs/callback.h7
2 files changed, 115 insertions, 4 deletions
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 4b1313eda6f5..470928898063 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -17,6 +17,9 @@
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/sunrpc/svcauth_gss.h>
+#if defined(CONFIG_NFS_V4_1)
+#include <linux/sunrpc/bc_xprt.h>
+#endif
#include <net/inet_sock.h>
@@ -28,6 +31,7 @@
struct nfs_callback_data {
unsigned int users;
+ struct svc_serv *serv;
struct svc_rqst *rqst;
struct task_struct *task;
};
@@ -131,6 +135,99 @@ out_err:
return ERR_PTR(ret);
}
+#if defined(CONFIG_NFS_V4_1)
+/*
+ * The callback service for NFSv4.1 callbacks
+ */
+static int
+nfs41_callback_svc(void *vrqstp)
+{
+ struct svc_rqst *rqstp = vrqstp;
+ struct svc_serv *serv = rqstp->rq_server;
+ struct rpc_rqst *req;
+ int error;
+ DEFINE_WAIT(wq);
+
+ set_freezable();
+
+ /*
+ * FIXME: do we really need to run this under the BKL? If so, please
+ * add a comment about what it's intended to protect.
+ */
+ lock_kernel();
+ while (!kthread_should_stop()) {
+ prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
+ spin_lock_bh(&serv->sv_cb_lock);
+ if (!list_empty(&serv->sv_cb_list)) {
+ req = list_first_entry(&serv->sv_cb_list,
+ struct rpc_rqst, rq_bc_list);
+ list_del(&req->rq_bc_list);
+ spin_unlock_bh(&serv->sv_cb_lock);
+ dprintk("Invoking bc_svc_process()\n");
+ error = bc_svc_process(serv, req, rqstp);
+ dprintk("bc_svc_process() returned w/ error code= %d\n",
+ error);
+ } else {
+ spin_unlock_bh(&serv->sv_cb_lock);
+ schedule();
+ }
+ finish_wait(&serv->sv_cb_waitq, &wq);
+ }
+ unlock_kernel();
+ nfs_callback_info.task = NULL;
+ svc_exit_thread(rqstp);
+ return 0;
+}
+
+/*
+ * Bring up the NFSv4.1 callback service
+ */
+struct svc_rqst *
+nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
+{
+ /*
+ * Save the svc_serv in the transport so that it can
+ * be referenced when the session backchannel is initialized
+ */
+ xprt->bc_serv = serv;
+
+ INIT_LIST_HEAD(&serv->sv_cb_list);
+ spin_lock_init(&serv->sv_cb_lock);
+ init_waitqueue_head(&serv->sv_cb_waitq);
+ return svc_prepare_thread(serv, &serv->sv_pools[0]);
+}
+
+static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
+ struct svc_serv *serv, struct rpc_xprt *xprt,
+ struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
+{
+ if (minorversion) {
+ *rqstpp = nfs41_callback_up(serv, xprt);
+ *callback_svc = nfs41_callback_svc;
+ }
+ return minorversion;
+}
+
+static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
+ struct nfs_callback_data *cb_info)
+{
+ if (minorversion)
+ xprt->bc_serv = cb_info->serv;
+}
+#else
+static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
+ struct svc_serv *serv, struct rpc_xprt *xprt,
+ struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
+{
+ return 0;
+}
+
+static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
+ struct nfs_callback_data *cb_info)
+{
+}
+#endif /* CONFIG_NFS_V4_1 */
+
/*
* Bring up the callback thread if it is not already up.
*/
@@ -141,21 +238,25 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
int (*callback_svc)(void *vrqstp);
char svc_name[12];
int ret = 0;
+ int minorversion_setup;
mutex_lock(&nfs_callback_mutex);
- if (nfs_callback_info.users++ || nfs_callback_info.task != NULL)
+ if (nfs_callback_info.users++ || nfs_callback_info.task != NULL) {
+ nfs_callback_bc_serv(minorversion, xprt, &nfs_callback_info);
goto out;
+ }
serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
if (!serv) {
ret = -ENOMEM;
goto out_err;
}
- if (!minorversion) {
+ minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
+ serv, xprt, &rqstp, &callback_svc);
+ if (!minorversion_setup) {
+ /* v4.0 callback setup */
rqstp = nfs4_callback_up(serv);
callback_svc = nfs4_callback_svc;
- } else {
- BUG(); /* for now */
}
if (IS_ERR(rqstp)) {
@@ -166,6 +267,7 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
svc_sock_update_bufs(serv);
sprintf(svc_name, "nfsv4.%u-svc", minorversion);
+ nfs_callback_info.serv = serv;
nfs_callback_info.rqst = rqstp;
nfs_callback_info.task = kthread_run(callback_svc,
nfs_callback_info.rqst,
@@ -173,6 +275,7 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
if (IS_ERR(nfs_callback_info.task)) {
ret = PTR_ERR(nfs_callback_info.task);
svc_exit_thread(nfs_callback_info.rqst);
+ nfs_callback_info.serv = NULL;
nfs_callback_info.rqst = NULL;
nfs_callback_info.task = NULL;
goto out_err;
@@ -205,6 +308,7 @@ void nfs_callback_down(void)
if (nfs_callback_info.users == 0 && nfs_callback_info.task != NULL) {
kthread_stop(nfs_callback_info.task);
svc_exit_thread(nfs_callback_info.rqst);
+ nfs_callback_info.serv = NULL;
nfs_callback_info.rqst = NULL;
nfs_callback_info.task = NULL;
}
diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
index 9b907f408b8d..29123b5604f2 100644
--- a/fs/nfs/callback.h
+++ b/fs/nfs/callback.h
@@ -70,6 +70,13 @@ extern void nfs_callback_down(void);
#define nfs_callback_down() do {} while(0)
#endif
+/*
+ * nfs41: Callbacks are expected to not cause substantial latency,
+ * so we limit their concurrency to 1 by setting up the maximum number
+ * of slots for the backchannel.
+ */
+#define NFS41_BC_MIN_CALLBACKS 1
+
extern unsigned int nfs_callback_set_tcpport;
extern unsigned short nfs_callback_tcpport;
extern unsigned short nfs_callback_tcpport6;