diff mbox series

[v2] ceph: add a new vxattr to return auth mds for an inode

Message ID 20210727184253.171816-1-jlayton@kernel.org
State New
Headers show
Series [v2] ceph: add a new vxattr to return auth mds for an inode | expand

Commit Message

Jeff Layton July 27, 2021, 6:42 p.m. UTC 
Add a new vxattr that shows what MDS is authoritative for an inode (if
we happen to have auth caps). If we don't have an auth cap for the inode
then just return -1.

URL: https://tracker.ceph.com/issues/1276
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/ceph/xattr.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

v2: ensure we hold the i_ceph_lock when working with the i_auth_cap.
diff mbox series

Patch

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 1242db8d3444..159a1ffa4f4b 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -340,6 +340,18 @@  static ssize_t ceph_vxattrcb_caps(struct ceph_inode_info *ci, char *val,
 			      ceph_cap_string(issued), issued);
 }
 
+static ssize_t ceph_vxattrcb_auth_mds(struct ceph_inode_info *ci,
+				       char *val, size_t size)
+{
+	int ret;
+
+	spin_lock(&ci->i_ceph_lock);
+	ret = ceph_fmt_xattr(val, size, "%d",
+			     ci->i_auth_cap ? ci->i_auth_cap->session->s_mds : -1);
+	spin_unlock(&ci->i_ceph_lock);
+	return ret;
+}
+
 #define CEPH_XATTR_NAME(_type, _name)	XATTR_CEPH_PREFIX #_type "." #_name
 #define CEPH_XATTR_NAME2(_type, _name, _name2)	\
 	XATTR_CEPH_PREFIX #_type "." #_name "." #_name2
@@ -473,6 +485,13 @@  static struct ceph_vxattr ceph_common_vxattrs[] = {
 		.exists_cb = NULL,
 		.flags = VXATTR_FLAG_READONLY,
 	},
+	{
+		.name = "ceph.auth_mds",
+		.name_size = sizeof("ceph.auth_mds"),
+		.getxattr_cb = ceph_vxattrcb_auth_mds,
+		.exists_cb = NULL,
+		.flags = VXATTR_FLAG_READONLY,
+	},
 	{ .name = NULL, 0 }	/* Required table terminator */
 };