NFS: Create a single nfs_get_root()

This patch splits out the NFS v4 specific functionality of
nfs4_get_root() into its own rpc_op called by the generic client, and
leaves nfs4_proc_get_rootfh() as its own stand alone function.  This
also allows me to change nfs4_remote_mount(), nfs4_xdev_mount() and
nfs4_remote_referral_mount() to use the generic client's nfs_get_root()
function.  Later patches in this series will collapse these functions
into one common function, so using the same get_root() function
everywhere simplifies future changes.

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

3 files changed, 30 insertions, 87 deletions

diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index 8a0f33ead77c..8abfb19bd3aa 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -178,87 +178,4 @@ out:
         return ret;
 }
 
-/*
- * get an NFS4 root dentry from the root filehandle
- */
-struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh,
-                             const char *devname)
-{
-        struct nfs_server *server = NFS_SB(sb);
-        struct nfs_fattr *fattr = NULL;
-        struct dentry *ret;
-        struct inode *inode;
-        void *name = kstrdup(devname, GFP_KERNEL);
-        int error;
-
-        dprintk("--> nfs4_get_root()\n");
-
-        if (!name)
-                return ERR_PTR(-ENOMEM);
-
-        /* get the info about the server and filesystem */
-        error = nfs4_server_capabilities(server, mntfh);
-        if (error < 0) {
-                dprintk("nfs_get_root: getcaps error = %d\n",
-                        -error);
-                kfree(name);
-                return ERR_PTR(error);
-        }
-
-        fattr = nfs_alloc_fattr();
-        if (fattr == NULL) {
-                kfree(name);
-                return ERR_PTR(-ENOMEM);
-        }
-
-        /* get the actual root for this mount */
-        error = server->nfs_client->rpc_ops->getattr(server, mntfh, fattr);
-        if (error < 0) {
-                dprintk("nfs_get_root: getattr error = %d\n", -error);
-                ret = ERR_PTR(error);
-                goto out;
-        }
-
-        if (fattr->valid & NFS_ATTR_FATTR_FSID &&
-            !nfs_fsid_equal(&server->fsid, &fattr->fsid))
-                memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
-
-        inode = nfs_fhget(sb, mntfh, fattr);
-        if (IS_ERR(inode)) {
-                dprintk("nfs_get_root: get root inode failed\n");
-                ret = ERR_CAST(inode);
-                goto out;
-        }
-
-        error = nfs_superblock_set_dummy_root(sb, inode);
-        if (error != 0) {
-                ret = ERR_PTR(error);
-                goto out;
-        }
-
-        /* root dentries normally start off anonymous and get spliced in later
-         * if the dentry tree reaches them; however if the dentry already
-         * exists, we'll pick it up at this point and use it as the root
-         */
-        ret = d_obtain_alias(inode);
-        if (IS_ERR(ret)) {
-                dprintk("nfs_get_root: get root dentry failed\n");
-                goto out;
-        }
-
-        security_d_instantiate(ret, inode);
-        spin_lock(&ret->d_lock);
-        if (IS_ROOT(ret) && !(ret->d_flags & DCACHE_NFSFS_RENAMED)) {
-                ret->d_fsdata = name;
-                name = NULL;
-        }
-        spin_unlock(&ret->d_lock);
-out:
-        if (name)
-                kfree(name);
-        nfs_free_fattr(fattr);
-        dprintk("<-- nfs4_get_root()\n");
-        return ret;
-}
-
 #endif /* CONFIG_NFS_V4 */
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 69212d2f882d..e6ab15f108b1 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -80,6 +80,7 @@ static int _nfs4_recover_proc_open(struct nfs4_opendata *data);
 static int nfs4_do_fsinfo(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *);
 static int nfs4_async_handle_error(struct rpc_task *, const struct nfs_server *, struct nfs4_state *);
 static void nfs_fixup_referral_attributes(struct nfs_fattr *fattr);
+static int nfs4_proc_getattr(struct nfs_server *, struct nfs_fh *, struct nfs_fattr *);
 static int _nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fattr *fattr);
 static int nfs4_do_setattr(struct inode *inode, struct rpc_cred *cred,
                             struct nfs_fattr *fattr, struct iattr *sattr,
@@ -2363,6 +2364,31 @@ int nfs4_proc_get_rootfh(struct nfs_server *server, struct nfs_fh *fhandle,
         return nfs4_map_errors(status);
 }
 
+static int nfs4_proc_get_root(struct nfs_server *server, struct nfs_fh *mntfh,
+                              struct nfs_fsinfo *info)
+{
+        int error;
+        struct nfs_fattr *fattr = info->fattr;
+
+        error = nfs4_server_capabilities(server, mntfh);
+        if (error < 0) {
+                dprintk("nfs4_get_root: getcaps error = %d\n", -error);
+                return error;
+        }
+
+        error = nfs4_proc_getattr(server, mntfh, fattr);
+        if (error < 0) {
+                dprintk("nfs4_get_root: getattr error = %d\n", -error);
+                return error;
+        }
+
+        if (fattr->valid & NFS_ATTR_FATTR_FSID &&
+            !nfs_fsid_equal(&server->fsid, &fattr->fsid))
+                memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
+
+        return error;
+}
+
 /*
  * Get locations and (maybe) other attributes of a referral.
  * Note that we'll actually follow the referral later when
@@ -6539,7 +6565,7 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
         .dir_inode_ops  = &nfs4_dir_inode_operations,
         .file_inode_ops = &nfs4_file_inode_operations,
         .file_ops       = &nfs4_file_operations,
-        .getroot        = nfs4_proc_get_rootfh,
+        .getroot        = nfs4_proc_get_root,
         .submount       = nfs4_submount,
         .getattr        = nfs4_proc_getattr,
         .setattr        = nfs4_proc_setattr,
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 4ac7fca7e4bf..75b1717e91dd 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2727,7 +2727,7 @@ nfs4_remote_mount(struct file_system_type *fs_type, int flags,
                 nfs_fscache_get_super_cookie(s, data->fscache_uniq, NULL);
         }
 
-        mntroot = nfs4_get_root(s, mntfh, dev_name);
+        mntroot = nfs_get_root(s, mntfh, dev_name);
         if (IS_ERR(mntroot)) {
                 error = PTR_ERR(mntroot);
                 goto error_splat_super;
@@ -2991,7 +2991,7 @@ nfs4_xdev_mount(struct file_system_type *fs_type, int flags,
                 nfs_fscache_get_super_cookie(s, NULL, data);
         }
 
-        mntroot = nfs4_get_root(s, data->fh, dev_name);
+        mntroot = nfs_get_root(s, data->fh, dev_name);
         if (IS_ERR(mntroot)) {
                 error = PTR_ERR(mntroot);
                 goto error_splat_super;
@@ -3082,7 +3082,7 @@ nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
                 nfs_fscache_get_super_cookie(s, NULL, data);
         }
 
-        mntroot = nfs4_get_root(s, mntfh, dev_name);
+        mntroot = nfs_get_root(s, mntfh, dev_name);
         if (IS_ERR(mntroot)) {
                 error = PTR_ERR(mntroot);
                 goto error_splat_super;