ovl: fix nested overlayfs mount
When the upper overlayfs checks "trusted.overlay.*" xattr on the underlying
overlayfs mount, it gets -EPERM, which confuses the upper overlayfs.
Fix this by returning -EOPNOTSUPP instead of -EPERM from
ovl_own_xattr_get() and ovl_own_xattr_set(). This behavior is consistent
with the behavior of ovl_listxattr(), which filters out the private
overlayfs xattrs.
Note: nested overlays are deprecated. But this change makes sense
regardless: these xattrs are private to the overlay and should always be
hidden. Hence getting and setting them should indicate this.
[SzMi: Use EOPNOTSUPP instead of ENODATA and use it for both getting and
setting "trusted.overlay." xattrs. This is a perfectly valid error code
for "we don't support this prefix", which is the case here.]
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index e19e2ed..aadb254 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -603,7 +603,7 @@ static int ovl_own_xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
const char *name, void *buffer, size_t size)
{
- return -EPERM;
+ return -EOPNOTSUPP;
}
static int ovl_own_xattr_set(const struct xattr_handler *handler,
@@ -611,7 +611,7 @@ static int ovl_own_xattr_set(const struct xattr_handler *handler,
const char *name, const void *value,
size_t size, int flags)
{
- return -EPERM;
+ return -EOPNOTSUPP;
}
static int ovl_other_xattr_get(const struct xattr_handler *handler,