[PATCH v3 2/2] ceph: add ceph.{clusterid/clientid} vxattrs suppport

[xiubli@redhat.com]

From: Xiubo Li <xiubli@redhat.com>

These two vxattrs will only exist in local client side, with which
we can easily know which mountpoint the file belongs to and also
they can help locate the debugfs path quickly.

URL: https://tracker.ceph.com/issues/48057
Signed-off-by: Xiubo Li <xiubli@redhat.com>
---
 fs/ceph/xattr.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 0fd05d3d4399..4a41db46e191 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -304,6 +304,23 @@ static ssize_t ceph_vxattrcb_snap_btime(struct ceph_inode_info *ci, char *val,
 				ci->i_snap_btime.tv_nsec);
 }
 
+static ssize_t ceph_vxattrcb_clusterid(struct ceph_inode_info *ci,
+				       char *val, size_t size)
+{
+	struct ceph_fs_client *fsc = ceph_sb_to_client(ci->vfs_inode.i_sb);
+
+	return ceph_fmt_xattr(val, size, "%pU", &fsc->client->fsid);
+}
+
+static ssize_t ceph_vxattrcb_clientid(struct ceph_inode_info *ci,
+				      char *val, size_t size)
+{
+	struct ceph_fs_client *fsc = ceph_sb_to_client(ci->vfs_inode.i_sb);
+
+	return ceph_fmt_xattr(val, size, "client%lld",
+			      ceph_client_gid(fsc->client));
+}
+
 #define CEPH_XATTR_NAME(_type, _name)	XATTR_CEPH_PREFIX #_type "." #_name
 #define CEPH_XATTR_NAME2(_type, _name, _name2)	\
 	XATTR_CEPH_PREFIX #_type "." #_name "." #_name2
@@ -407,6 +424,24 @@ static struct ceph_vxattr ceph_file_vxattrs[] = {
 	{ .name = NULL, 0 }	/* Required table terminator */
 };
 
+static struct ceph_vxattr ceph_vxattrs[] = {
+	{
+		.name = "ceph.clusterid",
+		.name_size = sizeof("ceph.clusterid"),
+		.getxattr_cb = ceph_vxattrcb_clusterid,
+		.exists_cb = NULL,
+		.flags = VXATTR_FLAG_READONLY,
+	},
+	{
+		.name = "ceph.clientid",
+		.name_size = sizeof("ceph.clientid"),
+		.getxattr_cb = ceph_vxattrcb_clientid,
+		.exists_cb = NULL,
+		.flags = VXATTR_FLAG_READONLY,
+	},
+	{ .name = NULL, 0 }	/* Required table terminator */
+};
+
 static struct ceph_vxattr *ceph_inode_vxattrs(struct inode *inode)
 {
 	if (S_ISDIR(inode->i_mode))
@@ -429,6 +464,13 @@ static struct ceph_vxattr *ceph_match_vxattr(struct inode *inode,
 		}
 	}
 
+	vxattr = ceph_vxattrs;
+	while (vxattr->name) {
+		if (!strcmp(vxattr->name, name))
+			return vxattr;
+		vxattr++;
+	}
+
 	return NULL;
 }
 
-- 
2.27.0