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Commit 95e598e7 authored by zhangyi (F)'s avatar zhangyi (F) Committed by Miklos Szeredi
Browse files

ovl: simplify ovl_check_empty_and_clear() 



Filter out non-whiteout non-upper entries from list of merge dir entries
while checking if merge dir is empty in ovl_check_empty_dir().
The remaining work for ovl_clear_empty() is to clear all entries on the
list.

[amir: split patch from rmdir bug fix]

Signed-off-by: default avatarzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent b79e05aa

fs/overlayfs/dir.c

+2 −3
Original line number Diff line number Diff line
@@ -300,7 +300,6 @@ static struct dentry *ovl_check_empty_and_clear(struct dentry *dentry) 
{

	int err;

	struct dentry *ret = NULL;

	enum ovl_path_type type = ovl_path_type(dentry);

	LIST_HEAD(list);



	err = ovl_check_empty_dir(dentry, &list);
@@ -313,13 +312,13 @@ static struct dentry *ovl_check_empty_and_clear(struct dentry *dentry) 
	 * When removing an empty opaque directory, then it makes no sense to

	 * replace it with an exact replica of itself.

	 *

	 * If no upperdentry then skip clearing whiteouts.

	 * If upperdentry has whiteouts, clear them.

	 *

	 * Can race with copy-up, since we don't hold the upperdir mutex.

	 * Doesn't matter, since copy-up can't create a non-empty directory

	 * from an empty one.

	 */

	if (OVL_TYPE_UPPER(type) && OVL_TYPE_MERGE(type))

	if (!list_empty(&list))

		ret = ovl_clear_empty(dentry, &list);



out_free:

fs/overlayfs/readdir.c

+20 −7
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ struct ovl_cache_entry { 
	struct list_head l_node;

	struct rb_node node;

	struct ovl_cache_entry *next_maybe_whiteout;

	bool is_upper;

	bool is_whiteout;

	char name[];

};
@@ -158,6 +159,7 @@ static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd, 
	/* Defer setting d_ino for upper entry to ovl_iterate() */

	if (ovl_calc_d_ino(rdd, p))

		p->ino = 0;

	p->is_upper = rdd->is_upper;

	p->is_whiteout = false;



	if (d_type == DT_CHR) {
@@ -851,7 +853,7 @@ const struct file_operations ovl_dir_operations = { 
int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)

{

	int err;

	struct ovl_cache_entry *p;

	struct ovl_cache_entry *p, *n;

	struct rb_root root = RB_ROOT;



	err = ovl_dir_read_merged(dentry, list, &root);
@@ -860,18 +862,29 @@ int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list) 


	err = 0;



	list_for_each_entry(p, list, l_node) {

		if (p->is_whiteout)

	list_for_each_entry_safe(p, n, list, l_node) {

		/*

		 * Select whiteouts in upperdir, they should

		 * be cleared when deleting this directory.

		 */

		if (p->is_whiteout) {

			if (p->is_upper)

				continue;

			goto del_entry;

		}



		if (p->name[0] == '.') {

			if (p->len == 1)

				continue;

				goto del_entry;

			if (p->len == 2 && p->name[1] == '.')

				continue;

				goto del_entry;

		}

		err = -ENOTEMPTY;

		break;



del_entry:

		list_del(&p->l_node);

		kfree(p);

	}



	return err;
@@ -885,7 +898,7 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list) 
	list_for_each_entry(p, list, l_node) {

		struct dentry *dentry;



		if (!p->is_whiteout)

		if (WARN_ON(!p->is_whiteout || !p->is_upper))

			continue;



		dentry = lookup_one_len(p->name, upper, p->len);