[PATCH 06/34] sysfs: make __sysfs_add_one() fail if the parent isn't a directory

[Tejun Heo <tj@kernel.org>]

Currently the kobject based interface guarantees that a parent
sysfs_dirent is always a directory; however, the planned kernfs
interface will be directly based on sysfs_dirents and the caller may
specify non-directory node as the parent.  Add an explicit check in
__sysfs_add_one() so that such attempts fail with -EINVAL.

Signed-off-by: Tejun Heo <tj@kernel.org>
---
 fs/sysfs/dir.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index de47ed3..bec4466 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -432,6 +432,9 @@ int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
 	struct sysfs_inode_attrs *ps_iattr;
 	int ret;
 
+	if (sysfs_type(parent_sd) != SYSFS_DIR)
+		return -EINVAL;
+
 	sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns);
 	sd->s_parent = sysfs_get(parent_sd);
 
-- 
1.8.3.1