NFS: Create a submount rpc_op

This simplifies the code for v2 and v3 and gives v4 a chance to decide
on referrals without needing to modify the generic client.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

7 files changed, 52 insertions, 67 deletions

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index d6994443f285..0fd1efaf1cff 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -185,17 +185,6 @@ static inline void nfs_fs_proc_exit(void)
 }
 #endif
 
-/* nfs4namespace.c */
-#ifdef CONFIG_NFS_V4
-extern struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry);
-#else
-static inline
-struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
-{
-        return ERR_PTR(-ENOENT);
-}
-#endif
-
 /* callback_xdr.c */
 extern struct svc_version nfs4_callback_version1;
 extern struct svc_version nfs4_callback_version4;
@@ -286,6 +275,10 @@ extern void nfs_sb_deactive(struct super_block *sb);
 extern char *nfs_path(char **p, struct dentry *dentry,
                       char *buffer, ssize_t buflen);
 extern struct vfsmount *nfs_d_automount(struct path *path);
+struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
+                              struct nfs_fh *, struct nfs_fattr *);
+struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
+                                 struct nfs_fattr *, rpc_authflavor_t);
 
 /* getroot.c */
 extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index 2a9591b0b150..e36fd8a51819 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -26,11 +26,6 @@ static LIST_HEAD(nfs_automount_list);
 static DECLARE_DELAYED_WORK(nfs_automount_task, nfs_expire_automounts);
 int nfs_mountpoint_expiry_timeout = 500 * HZ;
 
-static struct vfsmount *nfs_do_submount(struct dentry *dentry,
-                                        struct nfs_fh *fh,
-                                        struct nfs_fattr *fattr,
-                                        rpc_authflavor_t authflavor);
-
 /*
  * nfs_path - reconstruct the path given an arbitrary dentry
  * @base - used to return pointer to the end of devname part of path
@@ -118,35 +113,6 @@ Elong:
         return ERR_PTR(-ENAMETOOLONG);
 }
 
-#ifdef CONFIG_NFS_V4
-static struct rpc_clnt *nfs_lookup_mountpoint(struct inode *dir,
-                                              struct qstr *name,
-                                              struct nfs_fh *fh,
-                                              struct nfs_fattr *fattr)
-{
-        int err;
-
-        if (NFS_PROTO(dir)->version == 4)
-                return nfs4_proc_lookup_mountpoint(dir, name, fh, fattr);
-
-        err = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, name, fh, fattr);
-        if (err)
-                return ERR_PTR(err);
-        return rpc_clone_client(NFS_SERVER(dir)->client);
-}
-#else /* CONFIG_NFS_V4 */
-static inline struct rpc_clnt *nfs_lookup_mountpoint(struct inode *dir,
-                                                     struct qstr *name,
-                                                     struct nfs_fh *fh,
-                                                     struct nfs_fattr *fattr)
-{
-        int err = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, name, fh, fattr);
-        if (err)
-                return ERR_PTR(err);
-        return rpc_clone_client(NFS_SERVER(dir)->client);
-}
-#endif /* CONFIG_NFS_V4 */
-
 /*
  * nfs_d_automount - Handle crossing a mountpoint on the server
  * @path - The mountpoint
@@ -162,10 +128,9 @@ static inline struct rpc_clnt *nfs_lookup_mountpoint(struct inode *dir,
 struct vfsmount *nfs_d_automount(struct path *path)
 {
         struct vfsmount *mnt;
-        struct dentry *parent;
+        struct nfs_server *server = NFS_SERVER(path->dentry->d_inode);
         struct nfs_fh *fh = NULL;
         struct nfs_fattr *fattr = NULL;
-        struct rpc_clnt *client;
 
         dprintk("--> nfs_d_automount()\n");
 
@@ -181,21 +146,7 @@ struct vfsmount *nfs_d_automount(struct path *path)
 
         dprintk("%s: enter\n", __func__);
 
-        /* Look it up again to get its attributes */
-        parent = dget_parent(path->dentry);
-        client = nfs_lookup_mountpoint(parent->d_inode, &path->dentry->d_name, fh, fattr);
-        dput(parent);
-        if (IS_ERR(client)) {
-                mnt = ERR_CAST(client);
-                goto out;
-        }
-
-        if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
-                mnt = nfs_do_refmount(client, path->dentry);
-        else
-                mnt = nfs_do_submount(path->dentry, fh, fattr, client->cl_auth->au_flavor);
-        rpc_shutdown_client(client);
-
+        mnt = server->nfs_client->rpc_ops->submount(server, path->dentry, fh, fattr);
         if (IS_ERR(mnt))
                 goto out;
 
@@ -268,10 +219,8 @@ static struct vfsmount *nfs_do_clone_mount(struct nfs_server *server,
  * @authflavor - security flavor to use when performing the mount
  *
  */
-static struct vfsmount *nfs_do_submount(struct dentry *dentry,
-                                        struct nfs_fh *fh,
-                                        struct nfs_fattr *fattr,
-                                        rpc_authflavor_t authflavor)
+struct vfsmount *nfs_do_submount(struct dentry *dentry, struct nfs_fh *fh,
+                                 struct nfs_fattr *fattr, rpc_authflavor_t authflavor)
 {
         struct nfs_clone_mount mountdata = {
                 .sb = dentry->d_sb,
@@ -304,3 +253,19 @@ out:
         dprintk("<-- nfs_do_submount() = %p\n", mnt);
         return mnt;
 }
+
+struct vfsmount *nfs_submount(struct nfs_server *server, struct dentry *dentry,
+                              struct nfs_fh *fh, struct nfs_fattr *fattr)
+{
+        int err;
+        struct dentry *parent = dget_parent(dentry);
+
+        /* Look it up again to get its attributes */
+        err = server->nfs_client->rpc_ops->lookup(server->client, parent->d_inode,
+                                                  &dentry->d_name, fh, fattr);
+        dput(parent);
+        if (err != 0)
+                return ERR_PTR(err);
+
+        return nfs_do_submount(dentry, fh, fattr, server->client->cl_auth->au_flavor);
+}
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 56dcefc2f3f7..c23214d55ecf 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -885,6 +885,7 @@ const struct nfs_rpc_ops nfs_v3_clientops = {
         .file_inode_ops = &nfs3_file_inode_operations,
         .file_ops       = &nfs_file_operations,
         .getroot        = nfs3_proc_get_root,
+        .submount       = nfs_submount,
         .getattr        = nfs3_proc_getattr,
         .setattr        = nfs3_proc_setattr,
         .lookup         = nfs3_proc_lookup,
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 53a487ee9867..97365b0f9d3f 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -208,6 +208,8 @@ extern const struct inode_operations nfs4_dir_inode_operations;
 /* nfs4namespace.c */
 rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *);
 struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *, struct inode *, struct qstr *);
+struct vfsmount *nfs4_submount(struct nfs_server *, struct dentry *,
+                               struct nfs_fh *, struct nfs_fattr *);
 
 /* nfs4proc.c */
 extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, struct rpc_cred *, struct nfs4_setclientid_res *);
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index a69ee3952bbe..80fc0fe7095e 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -329,7 +329,7 @@ out:
  * @dentry - dentry of referral
  *
  */
-struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
+static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
 {
         struct vfsmount *mnt = ERR_PTR(-ENOMEM);
         struct dentry *parent;
@@ -370,3 +370,25 @@ out:
         dprintk("%s: done\n", __func__);
         return mnt;
 }
+
+struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry,
+                               struct nfs_fh *fh, struct nfs_fattr *fattr)
+{
+        struct dentry *parent = dget_parent(dentry);
+        struct rpc_clnt *client;
+        struct vfsmount *mnt;
+
+        /* Look it up again to get its attributes and sec flavor */
+        client = nfs4_proc_lookup_mountpoint(parent->d_inode, &dentry->d_name, fh, fattr);
+        dput(parent);
+        if (IS_ERR(client))
+                return ERR_CAST(client);
+
+        if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
+                mnt = nfs_do_refmount(client, dentry);
+        else
+                mnt = nfs_do_submount(dentry, fh, fattr, client->cl_auth->au_flavor);
+
+        rpc_shutdown_client(client);
+        return mnt;
+}
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index fa661b91e57c..2091af294c61 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6571,6 +6571,7 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
         .file_inode_ops = &nfs4_file_inode_operations,
         .file_ops       = &nfs4_file_operations,
         .getroot        = nfs4_proc_get_root,
+        .submount       = nfs4_submount,
         .getattr        = nfs4_proc_getattr,
         .setattr        = nfs4_proc_setattr,
         .lookup         = nfs4_proc_lookup,
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index 22ee70586875..76b3229fc527 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -742,6 +742,7 @@ const struct nfs_rpc_ops nfs_v2_clientops = {
         .file_inode_ops = &nfs_file_inode_operations,
         .file_ops       = &nfs_file_operations,
         .getroot        = nfs_proc_get_root,
+        .submount       = nfs_submount,
         .getattr        = nfs_proc_getattr,
         .setattr        = nfs_proc_setattr,
         .lookup         = nfs_proc_lookup,