ceph: don't rely on error_string to validate blocklisted session.

The "error_string" in the metadata of MClientSession is being
parsed by kclient to validate whether the session is blocklisted.
The "error_string" is for humans and shouldn't be relied on it.
Hence added the flag to MClientsession to indicate the session
is blocklisted.

[ jlayton: minor formatting cleanup ]

URL: https://tracker.ceph.com/issues/47450
Signed-off-by: Kotresh HR <khiremat@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 52d1b538c656c048a30e876a6d189b50f1e81a56..522790c64db4cc8544a40b4c8728b070a9f8b9c8 100644 (file)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -3361,9 +3361,14 @@ static void handle_session(struct ceph_mds_session *session,
 
        if (msg_version >= 3) {
                u32 len;
-               /* version >= 2, metadata */
-               if (__decode_session_metadata(&p, end, &blocklisted) < 0)
+               /* version >= 2 and < 5, decode metadata, skip otherwise
+                * as it's handled via flags.
+                */
+               if (msg_version >= 5)
+                       ceph_decode_skip_map(&p, end, string, string, bad);
+               else if (__decode_session_metadata(&p, end, &blocklisted) < 0)
                        goto bad;
+
                /* version >= 3, feature bits */
                ceph_decode_32_safe(&p, end, len, bad);
                if (len) {
@@ -3372,6 +3377,18 @@ static void handle_session(struct ceph_mds_session *session,
                }
        }
 
+       if (msg_version >= 5) {
+               u32 flags;
+               /* version >= 4, struct_v, struct_cv, len, metric_spec */
+               ceph_decode_skip_n(&p, end, 2 + sizeof(u32) * 2, bad);
+               /* version >= 5, flags   */
+                ceph_decode_32_safe(&p, end, flags, bad);
+               if (flags & CEPH_SESSION_BLOCKLISTED) {
+                       pr_warn("mds%d session blocklisted\n", session->s_mds);
+                       blocklisted = true;
+               }
+       }
+
        mutex_lock(&mdsc->mutex);
        if (op == CEPH_SESSION_CLOSE) {
                ceph_get_mds_session(session);

diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index bc2699feddbeb7d1b29000dd7b51c4888276495d..7ad6c3d0db7da1f2f76e26b540b0bfef75df15be 100644 (file)
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -302,6 +302,8 @@ enum {
        CEPH_SESSION_REQUEST_FLUSH_MDLOG,
 };
 
+#define CEPH_SESSION_BLOCKLISTED       (1 << 0)  /* session blocklisted */
+
 extern const char *ceph_session_op_name(int op);
 
 struct ceph_mds_session_head {