cleanup: rewrite long while(1) loop more cleanly

diff --git a/fs/unionfs/copyup.c b/fs/unionfs/copyup.c
index 747e6574a7a0f24aa317c7089b22022fdd048183..56e1371054378eebba18a758e75625d23c8ae659 100644 (file)
--- a/fs/unionfs/copyup.c
+++ b/fs/unionfs/copyup.c
@@ -700,89 +700,81 @@ static struct dentry *create_parents_named(struct inode *dir,
        sb = dentry->d_sb;
 
        /*
-        * This is basically while(child_dentry != dentry).  This loop is
-        * horrible to follow and should be replaced with cleaner code.
+        * This code goes between the begin/end labels and basically
+        * emulates a while(child_dentry != dentry), only cleaner and
+        * shorter than what would be a much longer while loop.
         */
-       while (1) {
-               /* get hidden parent dir in the current branch */
-               hidden_parent_dentry =
-                       unionfs_lower_dentry_idx(parent_dentry, bindex);
-               unionfs_unlock_dentry(parent_dentry);
+begin:
+       /* get hidden parent dir in the current branch */
+       hidden_parent_dentry = unionfs_lower_dentry_idx(parent_dentry, bindex);
+       unionfs_unlock_dentry(parent_dentry);
+
+       /* init the values to lookup */
+       childname = child_dentry->d_name.name;
+       childnamelen = child_dentry->d_name.len;
+
+       if (child_dentry != dentry) {
+               /* lookup child in the underlying file system */
+               hidden_dentry = lookup_one_len(childname, hidden_parent_dentry,
+                                              childnamelen);
+               if (IS_ERR(hidden_dentry))
+                       goto out;
+       } else {
+               /*
+                * Is the name a whiteout of the child name ?  lookup the
+                * whiteout child in the underlying file system
+                */
+               hidden_dentry = lookup_one_len(name, hidden_parent_dentry,
+                                              strlen(name));
+               if (IS_ERR(hidden_dentry))
+                       goto out;
 
-               /* init the values to lookup */
-               childname = child_dentry->d_name.name;
-               childnamelen = child_dentry->d_name.len;
+               /* Replace the current dentry (if any) with the new one */
+               dput(unionfs_lower_dentry_idx(dentry, bindex));
+               unionfs_set_lower_dentry_idx(dentry, bindex,
+                                            hidden_dentry);
 
-               if (child_dentry != dentry) {
-                       /* lookup child in the underlying file system */
-                       hidden_dentry =
-                               lookup_one_len(childname, hidden_parent_dentry,
-                                              childnamelen);
-                       if (IS_ERR(hidden_dentry))
-                               goto out;
-               } else {
+               __cleanup_dentry(dentry, bindex, old_bstart, old_bend);
+               goto out;
+       }
 
-                       /*
-                        * is the name a whiteout of the child name ?
-                        * lookup the whiteout child in the underlying file
-                        * system
-                        */
-                       hidden_dentry =
-                               lookup_one_len(name, hidden_parent_dentry,
-                                              strlen(name));
-                       if (IS_ERR(hidden_dentry))
-                               goto out;
+       if (hidden_dentry->d_inode) {
+               /*
+                * since this already exists we dput to avoid
+                * multiple references on the same dentry
+                */
+               dput(hidden_dentry);
+       } else {
+               struct sioq_args args;
 
-                       /*
-                        * Replace the current dentry (if any) with the new
-                        * one.
-                        */
-                       dput(unionfs_lower_dentry_idx(dentry, bindex));
-                       unionfs_set_lower_dentry_idx(dentry, bindex,
-                                                    hidden_dentry);
+               /* it's a negative dentry, create a new dir */
+               hidden_parent_dentry = lock_parent(hidden_dentry);
 
-                       __cleanup_dentry(dentry, bindex, old_bstart, old_bend);
-                       break;
-               }
+               args.mkdir.parent = hidden_parent_dentry->d_inode;
+               args.mkdir.dentry = hidden_dentry;
+               args.mkdir.mode = child_dentry->d_inode->i_mode;
 
-               if (hidden_dentry->d_inode) {
-                       /*
-                        * since this already exists we dput to avoid
-                        * multiple references on the same dentry
-                        */
-                       dput(hidden_dentry);
-               } else {
-                       struct sioq_args args;
-
-                       /* its a negative dentry, create a new dir */
-                       hidden_parent_dentry = lock_parent(hidden_dentry);
-
-                       args.mkdir.parent = hidden_parent_dentry->d_inode;
-                       args.mkdir.dentry = hidden_dentry;
-                       args.mkdir.mode = child_dentry->d_inode->i_mode;
-
-                       run_sioq(__unionfs_mkdir, &args);
-                       err = args.err;
-
-                       if (!err)
-                               err = copyup_permissions(dir->i_sb,
-                                                        child_dentry,
-                                                        hidden_dentry);
-                       unlock_dir(hidden_parent_dentry);
-                       if (err) {
-                               dput(hidden_dentry);
-                               hidden_dentry = ERR_PTR(err);
-                               goto out;
-                       }
+               run_sioq(__unionfs_mkdir, &args);
+               err = args.err;
 
+               if (!err)
+                       err = copyup_permissions(dir->i_sb, child_dentry,
+                                                hidden_dentry);
+               unlock_dir(hidden_parent_dentry);
+               if (err) {
+                       dput(hidden_dentry);
+                       hidden_dentry = ERR_PTR(err);
+                       goto out;
                }
 
-               __set_inode(child_dentry, hidden_dentry, bindex);
-               __set_dentry(child_dentry, hidden_dentry, bindex);
-
-               parent_dentry = child_dentry;
-               child_dentry = path[--count];
        }
+
+       __set_inode(child_dentry, hidden_dentry, bindex);
+       __set_dentry(child_dentry, hidden_dentry, bindex);
+
+       parent_dentry = child_dentry;
+       child_dentry = path[--count];
+       goto begin;
 out:
        kfree(path);
        return hidden_dentry;