1 files changed, 42 insertions, 10 deletions

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 18677cd4e62f..7d10278db30d 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -207,7 +207,17 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *paren
 		return ERR_PTR(-ENOENT);
 	}
 	sd->s_frag = get_fragment(frag);
-	list_add(&sd->s_sibling, &parent_sd->s_children);
+
+	/*
+	 * configfs_lookup scans only for unpinned items. s_children is
+	 * partitioned so that configfs_lookup can bail out early.
+	 * CONFIGFS_PINNED and CONFIGFS_NOT_PINNED are not symmetrical.  readdir
+	 * cursors still need to be inserted at the front of the list.
+	 */
+	if (sd->s_type & CONFIGFS_PINNED)
+		list_add_tail(&sd->s_sibling, &parent_sd->s_children);
+	else
+		list_add(&sd->s_sibling, &parent_sd->s_children);
 	spin_unlock(&configfs_dirent_lock);
 
 	return sd;
@@ -220,10 +230,11 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *paren
  *
  * called with parent inode's i_mutex held
  */
-static int configfs_dirent_exists(struct configfs_dirent *parent_sd,
-				  const unsigned char *new)
+static int configfs_dirent_exists(struct dentry *dentry)
 {
-	struct configfs_dirent * sd;
+	struct configfs_dirent *parent_sd = dentry->d_parent->d_fsdata;
+	const unsigned char *new = dentry->d_name.name;
+	struct configfs_dirent *sd;
 
 	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
 		if (sd->s_element) {
@@ -289,10 +300,6 @@ static int configfs_create_dir(struct config_item *item, struct dentry *dentry,
 
 	BUG_ON(!item);
 
-	error = configfs_dirent_exists(p->d_fsdata, dentry->d_name.name);
-	if (unlikely(error))
-		return error;
-
 	error = configfs_make_dirent(p->d_fsdata, dentry, item, mode,
 				     CONFIGFS_DIR | CONFIGFS_USET_CREATING,
 				     frag);
@@ -451,6 +458,18 @@ static struct dentry * configfs_lookup(struct inode *dir,
 
 	spin_lock(&configfs_dirent_lock);
 	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
+
+		/*
+		 * s_children is partitioned, see configfs_new_dirent. The first
+		 * pinned item indicates we can stop scanning.
+		 */
+		if (sd->s_type & CONFIGFS_PINNED)
+			break;
+
+		/*
+		 * Note: CONFIGFS_PINNED and CONFIGFS_NOT_PINNED are asymmetric.
+		 * there may be a readdir cursor in this list
+		 */
 		if ((sd->s_type & CONFIGFS_NOT_PINNED) &&
 		    !strcmp(configfs_get_name(sd), dentry->d_name.name)) {
 			struct configfs_attribute *attr = sd->s_element;
@@ -580,6 +599,7 @@ static void detach_attrs(struct config_item * item)
 static int populate_attrs(struct config_item *item)
 {
 	const struct config_item_type *t = item->ci_type;
+	struct configfs_group_operations *ops;
 	struct configfs_attribute *attr;
 	struct configfs_bin_attribute *bin_attr;
 	int error = 0;
@@ -587,14 +607,23 @@ static int populate_attrs(struct config_item *item)
 
 	if (!t)
 		return -EINVAL;
+
+	ops = t->ct_group_ops;
+
 	if (t->ct_attrs) {
 		for (i = 0; (attr = t->ct_attrs[i]) != NULL; i++) {
+			if (ops && ops->is_visible && !ops->is_visible(item, attr, i))
+				continue;
+
 			if ((error = configfs_create_file(item, attr)))
 				break;
 		}
 	}
 	if (t->ct_bin_attrs) {
 		for (i = 0; (bin_attr = t->ct_bin_attrs[i]) != NULL; i++) {
+			if (ops && ops->is_bin_visible && !ops->is_bin_visible(item, bin_attr, i))
+				continue;
+
 			error = configfs_create_bin_file(item, bin_attr);
 			if (error)
 				break;
@@ -1875,8 +1904,11 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
 	if (dentry) {
 		d_add(dentry, NULL);
 
-		err = configfs_attach_group(sd->s_element, &group->cg_item,
-					    dentry, frag);
+		err = configfs_dirent_exists(dentry);
+		if (!err)
+			err = configfs_attach_group(sd->s_element,
+						    &group->cg_item,
+						    dentry, frag);
 		if (err) {
 			BUG_ON(d_inode(dentry));
 			d_drop(dentry);