[PATCH v13 35/59] ceph: add a new ceph.fscrypt.auth vxattr

[Jeff Layton]

Give the client a way to get at the xattr from userland, mostly for
future debugging purposes.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
 fs/ceph/xattr.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 58628cef4207..e080116608b2 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -352,6 +352,23 @@ static ssize_t ceph_vxattrcb_auth_mds(struct ceph_inode_info *ci,
 	return ret;
 }
 
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+static bool ceph_vxattrcb_fscrypt_auth_exists(struct ceph_inode_info *ci)
+{
+	return ci->fscrypt_auth_len;
+}
+
+static ssize_t ceph_vxattrcb_fscrypt_auth(struct ceph_inode_info *ci, char *val, size_t size)
+{
+	if (size) {
+		if (size < ci->fscrypt_auth_len)
+			return -ERANGE;
+		memcpy(val, ci->fscrypt_auth, ci->fscrypt_auth_len);
+	}
+	return ci->fscrypt_auth_len;
+}
+#endif /* CONFIG_FS_ENCRYPTION */
+
 #define CEPH_XATTR_NAME(_type, _name)	XATTR_CEPH_PREFIX #_type "." #_name
 #define CEPH_XATTR_NAME2(_type, _name, _name2)	\
 	XATTR_CEPH_PREFIX #_type "." #_name "." #_name2
@@ -500,6 +517,15 @@ static struct ceph_vxattr ceph_common_vxattrs[] = {
 		.exists_cb = NULL,
 		.flags = VXATTR_FLAG_READONLY,
 	},
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+	{
+		.name = "ceph.fscrypt.auth",
+		.name_size = sizeof("ceph.fscrypt.auth"),
+		.getxattr_cb = ceph_vxattrcb_fscrypt_auth,
+		.exists_cb = ceph_vxattrcb_fscrypt_auth_exists,
+		.flags = VXATTR_FLAG_READONLY,
+	},
+#endif /* CONFIG_FS_ENCRYPTION */
 	{ .name = NULL, 0 }	/* Required table terminator */
 };
 
-- 
2.35.1