[PATCH v2 2/4] ceph: save name and fsid in mount source

[Hu Weiwen <huww98@outlook.com>]

We have name and fsid in the new device syntax.  It is confusing that
the kernel accept these info but do not take them into account when
connecting to the cluster.

Although the mount.ceph helper program will extract the name from device
spec and pass it as name options, these changes are still useful if we
don't have that program installed, or if we want to call `mount()'
directly.

Signed-off-by: Hu Weiwen <huww98@outlook.com>
---
 fs/ceph/super.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 9185ff00bb61..3d36ee4543ed 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -267,6 +267,7 @@ static int ceph_parse_new_source(const char *dev_name, const char *dev_name_end,
 	struct ceph_fsid fsid;
 	struct ceph_parse_opts_ctx *pctx = fc->fs_private;
 	struct ceph_mount_options *fsopt = pctx->opts;
+	struct ceph_options *copts = pctx->copts;
 	char *fsid_start, *fs_name_start;
 
 	if (*dev_name_end != '=') {
@@ -285,6 +286,12 @@ static int ceph_parse_new_source(const char *dev_name, const char *dev_name_end,
 
 	if (ceph_parse_fsid(fsid_start, &fsid))
 		return invalfc(fc, "Invalid FSID");
+	if (!(copts->flags & CEPH_OPT_FSID)) {
+		copts->fsid = fsid;
+		copts->flags |= CEPH_OPT_FSID;
+	} else if (ceph_fsid_compare(&fsid, &copts->fsid)) {
+		return invalfc(fc, "Mismatching cluster FSID between mount source and options");
+	}
 
 	++fs_name_start; /* start of file system name */
 	len = dev_name_end - fs_name_start;
@@ -294,10 +301,20 @@ static int ceph_parse_new_source(const char *dev_name, const char *dev_name_end,
 		if (!fsopt->mds_namespace)
 			return -ENOMEM;
 	} else if (!strstrn_equals(fsopt->mds_namespace, fs_name_start, len)) {
-		return invalfc(fc, "Mismatching mds_namespace");
+		return invalfc(fc, "Mismatching mds_namespace between mount source and options");
 	}
 	dout("file system (mds namespace) '%s'\n", fsopt->mds_namespace);
 
+	len = fsid_start - dev_name - 1;
+	if (!copts->name) {
+		copts->name = kstrndup(dev_name, len, GFP_KERNEL);
+		if (!copts->name)
+			return -ENOMEM;
+	} else if (!strstrn_equals(copts->name, dev_name, len)) {
+		return invalfc(fc, "Mismatching cephx name between mount source and options");
+	}
+	dout("cephx name '%s'\n", copts->name);
+
 	fsopt->new_dev_syntax = true;
 	return 0;
 }
-- 
2.25.1