NFS: Clean-up: Replace nfs_copy_user_string with strndup_user

The new string utility function strndup_user can be used instead of
nfs_copy_user_string, eliminating an unnecessary duplication of function.

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

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index e7d1970..04ad881 100644 (file)
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -785,27 +785,6 @@ static void nfs4_fill_super(struct super_block *sb)
        nfs_initialise_sb(sb);
 }
 
-static void *nfs_copy_user_string(char *dst, struct nfs_string *src, int maxlen)
-{
-       void *p = NULL;
-
-       if (!src->len)
-               return ERR_PTR(-EINVAL);
-       if (src->len < maxlen)
-               maxlen = src->len;
-       if (dst == NULL) {
-               p = dst = kmalloc(maxlen + 1, GFP_KERNEL);
-               if (p == NULL)
-                       return ERR_PTR(-ENOMEM);
-       }
-       if (copy_from_user(dst, src->data, maxlen)) {
-               kfree(p);
-               return ERR_PTR(-EFAULT);
-       }
-       dst[maxlen] = '\0';
-       return dst;
-}
-
 /*
  * Get the superblock for an NFS4 mountpoint
  */
@@ -819,8 +798,7 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
        rpc_authflavor_t authflavour;
        struct nfs_fh mntfh;
        struct dentry *mntroot;
-       char *mntpath = NULL, *hostname = NULL, ip_addr[16];
-       void *p;
+       char *p, *mntpath = NULL, *hostname = NULL, *ip_addr = NULL;
        int error;
 
        if (data == NULL) {
@@ -857,39 +835,39 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
                        dprintk("%s: Invalid number of RPC auth flavours %d.\n",
                                        __FUNCTION__, data->auth_flavourlen);
                        error = -EINVAL;
-                       goto out_err_noserver;
+                       goto out;
                }
 
                if (copy_from_user(&authflavour, data->auth_flavours,
                                   sizeof(authflavour))) {
                        error = -EFAULT;
-                       goto out_err_noserver;
+                       goto out;
                }
        }
 
-       p = nfs_copy_user_string(NULL, &data->hostname, NFS4_MAXNAMLEN);
+       p = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
        if (IS_ERR(p))
                goto out_err;
        hostname = p;
 
-       p = nfs_copy_user_string(NULL, &data->mnt_path, NFS4_MAXPATHLEN);
+       p = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
        if (IS_ERR(p))
                goto out_err;
        mntpath = p;
 
        dprintk("MNTPATH: %s\n", mntpath);
 
-       p = nfs_copy_user_string(ip_addr, &data->client_addr,
-                                sizeof(ip_addr) - 1);
+       p = strndup_user(data->client_addr.data, 16);
        if (IS_ERR(p))
                goto out_err;
+       ip_addr = p;
 
        /* Get a volume representation */
        server = nfs4_create_server(data, hostname, &addr, mntpath, ip_addr,
                                    authflavour, &mntfh);
        if (IS_ERR(server)) {
                error = PTR_ERR(server);
-               goto out_err_noserver;
+               goto out;
        }
 
        /* Get a superblock - note that we may end up sharing one that already exists */
@@ -919,25 +897,26 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
        s->s_flags |= MS_ACTIVE;
        mnt->mnt_sb = s;
        mnt->mnt_root = mntroot;
+       error = 0;
+
+out:
+       kfree(ip_addr);
        kfree(mntpath);
        kfree(hostname);
-       return 0;
+       return error;
 
 out_err:
        error = PTR_ERR(p);
-       goto out_err_noserver;
+       goto out;
 
 out_free:
        nfs_free_server(server);
-out_err_noserver:
-       kfree(mntpath);
-       kfree(hostname);
-       return error;
+       goto out;
 
 error_splat_super:
        up_write(&s->s_umount);
        deactivate_super(s);
-       goto out_err_noserver;
+       goto out;
 }
 
 static void nfs4_kill_super(struct super_block *sb)