NFS: Refactor nfs_get_client(): initialize nfs_client

Clean up: Continue to rationalize the locking in nfs_get_client() by
moving the logic that handles the case where a matching server IP
address is not found.

When we support server trunking detection, client initialization may
return a different nfs_client struct than was passed to it.  Change
the synopsis of the init_client methods to return an nfs_client.

The client initialization logic in nfs_get_client() is not much more
than a wrapper around ->init_client.  It's simpler to keep the little
bits of error handling in the version-specific init_client methods.

No behavior change is expected.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 5f19f95..8a4b3c2 100644 (file)
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -546,7 +546,6 @@ nfs_get_client(const struct nfs_client_initdata *cl_init,
               int noresvport)
 {
        struct nfs_client *clp, *new = NULL;
-       int error;
        struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
 
        dprintk("--> nfs_get_client(%s,v%u)\n",
@@ -563,8 +562,13 @@ nfs_get_client(const struct nfs_client_initdata *cl_init,
                                nfs_free_client(new);
                        return nfs_found_client(cl_init, clp);
                }
-               if (new)
-                       goto install_client;
+               if (new) {
+                       list_add(&new->cl_share_link, &nn->nfs_client_list);
+                       spin_unlock(&nn->nfs_client_lock);
+                       return cl_init->rpc_ops->init_client(new,
+                                               timeparms, ip_addr,
+                                               authflavour, noresvport);
+               }
 
                spin_unlock(&nn->nfs_client_lock);
 
@@ -574,21 +578,6 @@ nfs_get_client(const struct nfs_client_initdata *cl_init,
        dprintk("<-- nfs_get_client() Failed to find %s (%ld)\n",
                cl_init->hostname ?: "", PTR_ERR(new));
        return new;
-
-       /* install a new client and return with it unready */
-install_client:
-       clp = new;
-       list_add(&clp->cl_share_link, &nn->nfs_client_list);
-       spin_unlock(&nn->nfs_client_lock);
-
-       error = cl_init->rpc_ops->init_client(clp, timeparms, ip_addr,
-                                             authflavour, noresvport);
-       if (error < 0) {
-               nfs_put_client(clp);
-               return ERR_PTR(error);
-       }
-       dprintk("--> nfs_get_client() = %p [new]\n", clp);
-       return clp;
 }
 
 /*
@@ -813,10 +802,19 @@ static int nfs_init_server_rpcclient(struct nfs_server *server,
        return 0;
 }
 
-/*
- * Initialise an NFS2 or NFS3 client
+/**
+ * nfs_init_client - Initialise an NFS2 or NFS3 client
+ *
+ * @clp: nfs_client to initialise
+ * @timeparms: timeout parameters for underlying RPC transport
+ * @ip_addr: IP presentation address (not used)
+ * @authflavor: authentication flavor for underlying RPC transport
+ * @noresvport: set if RPC transport can use an ephemeral source port
+ *
+ * Returns pointer to an NFS client, or an ERR_PTR value.
  */
-int nfs_init_client(struct nfs_client *clp, const struct rpc_timeout *timeparms,
+struct nfs_client *nfs_init_client(struct nfs_client *clp,
+                   const struct rpc_timeout *timeparms,
                    const char *ip_addr, rpc_authflavor_t authflavour,
                    int noresvport)
 {
@@ -825,7 +823,7 @@ int nfs_init_client(struct nfs_client *clp, const struct rpc_timeout *timeparms,
        if (clp->cl_cons_state == NFS_CS_READY) {
                /* the client is already initialised */
                dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp);
-               return 0;
+               return clp;
        }
 
        /*
@@ -837,12 +835,13 @@ int nfs_init_client(struct nfs_client *clp, const struct rpc_timeout *timeparms,
        if (error < 0)
                goto error;
        nfs_mark_client_ready(clp, NFS_CS_READY);
-       return 0;
+       return clp;
 
 error:
        nfs_mark_client_ready(clp, error);
+       nfs_put_client(clp);
        dprintk("<-- nfs_init_client() = xerror %d\n", error);
-       return error;
+       return ERR_PTR(error);
 }
 
 /*
@@ -1358,14 +1357,22 @@ static int nfs4_init_client_minor_version(struct nfs_client *clp)
        return nfs4_init_callback(clp);
 }
 
-/*
- * Initialise an NFS4 client record
+/**
+ * nfs4_init_client - Initialise an NFS4 client record
+ *
+ * @clp: nfs_client to initialise
+ * @timeparms: timeout parameters for underlying RPC transport
+ * @ip_addr: callback IP address in presentation format
+ * @authflavor: authentication flavor for underlying RPC transport
+ * @noresvport: set if RPC transport can use an ephemeral source port
+ *
+ * Returns pointer to an NFS client, or an ERR_PTR value.
  */
-int nfs4_init_client(struct nfs_client *clp,
-                    const struct rpc_timeout *timeparms,
-                    const char *ip_addr,
-                    rpc_authflavor_t authflavour,
-                    int noresvport)
+struct nfs_client *nfs4_init_client(struct nfs_client *clp,
+                                   const struct rpc_timeout *timeparms,
+                                   const char *ip_addr,
+                                   rpc_authflavor_t authflavour,
+                                   int noresvport)
 {
        char buf[INET6_ADDRSTRLEN + 1];
        int error;
@@ -1373,7 +1380,7 @@ int nfs4_init_client(struct nfs_client *clp,
        if (clp->cl_cons_state == NFS_CS_READY) {
                /* the client is initialised already */
                dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
-               return 0;
+               return clp;
        }
 
        /* Check NFS protocol revision and initialize RPC op vector */
@@ -1413,12 +1420,13 @@ int nfs4_init_client(struct nfs_client *clp,
 
        if (!nfs4_has_session(clp))
                nfs_mark_client_ready(clp, NFS_CS_READY);
-       return 0;
+       return clp;
 
 error:
        nfs_mark_client_ready(clp, error);
+       nfs_put_client(clp);
        dprintk("<-- nfs4_init_client() = xerror %d\n", error);
-       return error;
+       return ERR_PTR(error);
 }
 
 /*

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 989959a..3a9e80c 100644 (file)
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -238,7 +238,7 @@ extern int nfs4_init_ds_session(struct nfs_client *clp);
 
 /* proc.c */
 void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
-extern int nfs_init_client(struct nfs_client *clp,
+extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
                           const struct rpc_timeout *timeparms,
                           const char *ip_addr, rpc_authflavor_t authflavour,
                           int noresvport);
@@ -373,7 +373,7 @@ void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
 
 /* nfs4proc.c */
 extern void __nfs4_read_done_cb(struct nfs_read_data *);
-extern int nfs4_init_client(struct nfs_client *clp,
+extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
                            const struct rpc_timeout *timeparms,
                            const char *ip_addr,
                            rpc_authflavor_t authflavour,

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index c420b8d..0c521cd 100644 (file)
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1397,7 +1397,8 @@ struct nfs_rpc_ops {
                                struct nfs_open_context *ctx,
                                int open_flags,
                                struct iattr *iattr);
-       int     (*init_client) (struct nfs_client *, const struct rpc_timeout *,
+       struct nfs_client *
+               (*init_client) (struct nfs_client *, const struct rpc_timeout *,
                                const char *, rpc_authflavor_t, int);
 };