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>

1 files changed, 16 insertions, 37 deletions

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index e7d197085834..04ad881eac77 100644
--- 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)