1 files changed, 0 insertions, 148 deletions
diff --git a/target/linux/generic/patches-4.1/140-overlayfs_readdir_locking_fix.patch b/target/linux/generic/patches-4.1/140-overlayfs_readdir_locking_fix.patch
deleted file mode 100644
index 67dff987d3..0000000000
--- a/target/linux/generic/patches-4.1/140-overlayfs_readdir_locking_fix.patch
+++ /dev/null
@@ -1,148 +0,0 @@
-Patch by: Miklos Szeredi <miklos@szeredi.hu>
-
-Some filesystems (e.g. jffs2) lock the same resources for both readdir
-and lookup, leading to a deadlock in ovl_cache_entry_new, which is called
-from the filldir, and calls lookup itself.
-
---- a/fs/overlayfs/readdir.c
-+++ b/fs/overlayfs/readdir.c
-@@ -23,6 +23,7 @@ struct ovl_cache_entry {
- 	u64 ino;
- 	struct list_head l_node;
- 	struct rb_node node;
-+	struct ovl_cache_entry *next_maybe_whiteout;
- 	bool is_whiteout;
- 	char name[];
- };
-@@ -39,7 +40,7 @@ struct ovl_readdir_data {
- 	struct rb_root root;
- 	struct list_head *list;
- 	struct list_head middle;
--	struct dentry *dir;
-+	struct ovl_cache_entry *first_maybe_whiteout;
- 	int count;
- 	int err;
- };
-@@ -79,7 +80,7 @@ static struct ovl_cache_entry *ovl_cache
- 	return NULL;
- }
- 
--static struct ovl_cache_entry *ovl_cache_entry_new(struct dentry *dir,
-+static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd,
- 						   const char *name, int len,
- 						   u64 ino, unsigned int d_type)
- {
-@@ -98,29 +99,8 @@ static struct ovl_cache_entry *ovl_cache
- 	p->is_whiteout = false;
- 
- 	if (d_type == DT_CHR) {
--		struct dentry *dentry;
--		const struct cred *old_cred;
--		struct cred *override_cred;
--
--		override_cred = prepare_creds();
--		if (!override_cred) {
--			kfree(p);
--			return NULL;
--		}
--
--		/*
--		 * CAP_DAC_OVERRIDE for lookup
--		 */
--		cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
--		old_cred = override_creds(override_cred);
--
--		dentry = lookup_one_len(name, dir, len);
--		if (!IS_ERR(dentry)) {
--			p->is_whiteout = ovl_is_whiteout(dentry);
--			dput(dentry);
--		}
--		revert_creds(old_cred);
--		put_cred(override_cred);
-+		p->next_maybe_whiteout = rdd->first_maybe_whiteout;
-+		rdd->first_maybe_whiteout = p;
- 	}
- 	return p;
- }
-@@ -148,7 +128,7 @@ static int ovl_cache_entry_add_rb(struct
- 			return 0;
- 	}
- 
--	p = ovl_cache_entry_new(rdd->dir, name, len, ino, d_type);
-+	p = ovl_cache_entry_new(rdd, name, len, ino, d_type);
- 	if (p == NULL)
- 		return -ENOMEM;
- 
-@@ -169,7 +149,7 @@ static int ovl_fill_lower(struct ovl_rea
- 	if (p) {
- 		list_move_tail(&p->l_node, &rdd->middle);
- 	} else {
--		p = ovl_cache_entry_new(rdd->dir, name, namelen, ino, d_type);
-+		p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type);
- 		if (p == NULL)
- 			rdd->err = -ENOMEM;
- 		else
-@@ -219,6 +199,43 @@ static int ovl_fill_merge(struct dir_con
- 		return ovl_fill_lower(rdd, name, namelen, offset, ino, d_type);
- }
- 
-+static int ovl_check_whiteouts(struct dentry *dir, struct ovl_readdir_data *rdd)
-+{
-+	int err = 0;
-+
-+	mutex_lock(&dir->d_inode->i_mutex);
-+	while (rdd->first_maybe_whiteout) {
-+		struct dentry *dentry;
-+		const struct cred *old_cred;
-+		struct cred *override_cred;
-+		struct ovl_cache_entry *p = rdd->first_maybe_whiteout;
-+
-+		rdd->first_maybe_whiteout = p->next_maybe_whiteout;
-+
-+		override_cred = prepare_creds();
-+		if (!override_cred) {
-+			err = -ENOMEM;
-+			break;
-+		}
-+		/*
-+		 * CAP_DAC_OVERRIDE for lookup
-+		 */
-+		cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
-+		old_cred = override_creds(override_cred);
-+
-+		dentry = lookup_one_len(p->name, dir, p->len);
-+		if (!IS_ERR(dentry)) {
-+			p->is_whiteout = ovl_is_whiteout(dentry);
-+			dput(dentry);
-+		}
-+		revert_creds(old_cred);
-+		put_cred(override_cred);
-+	}
-+	mutex_unlock(&dir->d_inode->i_mutex);
-+
-+	return err;
-+}
-+
- static inline int ovl_dir_read(struct path *realpath,
- 			       struct ovl_readdir_data *rdd)
- {
-@@ -229,7 +246,7 @@ static inline int ovl_dir_read(struct pa
- 	if (IS_ERR(realfile))
- 		return PTR_ERR(realfile);
- 
--	rdd->dir = realpath->dentry;
-+	rdd->first_maybe_whiteout = NULL;
- 	rdd->ctx.pos = 0;
- 	do {
- 		rdd->count = 0;
-@@ -238,6 +255,10 @@ static inline int ovl_dir_read(struct pa
- 		if (err >= 0)
- 			err = rdd->err;
- 	} while (!err && rdd->count);
-+
-+	if (!err && rdd->first_maybe_whiteout)
-+		err = ovl_check_whiteouts(realpath->dentry, rdd);
-+
- 	fput(realfile);
- 
- 	return err;