client/Client.cc: add feature to reconnect client after MDS reset

Client.cc marks session as stale instead of reconecting after received
reset from MDS. On MDS side session is closed so MDS is ignoring cap
renew. This adds option to reconnect stale client sessions instead of
just marking sessions stale.

Fixes: http://tracker.ceph.com/issues/18757
Signed-off-by: Henrik Korkuc <henrik@kirneh.eu>
(cherry picked from commit e0bbc704676ef4aed510daff075ef63c9e73b7b3)

diff --git a/doc/cephfs/client-config-ref.rst b/doc/cephfs/client-config-ref.rst
index a789a6d4d16c8bb51365729a2c05d81358ccf28a..ce5562fae406f9ee4ff9d03eaf81c4d5a20c6166 100644 (file)
--- a/doc/cephfs/client-config-ref.rst
+++ b/doc/cephfs/client-config-ref.rst
@@ -147,6 +147,12 @@
 :Type: Integer
 :Default: ``131072`` (128KB)
 
+``client_reconnect_stale``
+
+:Description: Automatically reconnect stale session.
+:Type: Boolean
+:Default: ``false``
+
 ``client_snapdir``
 
 :Description: Set the snapshot directory name.

diff --git a/src/client/Client.cc b/src/client/Client.cc
index 2d3284b76dce8d0cfa1002e1a3de1d1a8938c862..59bba676d9bf64cc240bb2ca3c35ca0b3ba1ec20 100644 (file)
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -12059,8 +12059,16 @@ void Client::ms_handle_remote_reset(Connection *con)
          break;
 
        case MetaSession::STATE_OPEN:
-         ldout(cct, 1) << "reset from mds we were open; mark session as stale" << dendl;
-         s->state = MetaSession::STATE_STALE;
+         {
+           const md_config_t *conf = cct->_conf;
+           if (conf->client_reconnect_stale) {
+             ldout(cct, 1) << "reset from mds we were open; close mds session for reconnect" << dendl;
+             _closed_mds_session(s);
+           } else {
+             ldout(cct, 1) << "reset from mds we were open; mark session as stale" << dendl;
+             s->state = MetaSession::STATE_STALE;
+           }
+         }
          break;
 
        case MetaSession::STATE_NEW:

diff --git a/src/common/config_opts.h b/src/common/config_opts.h
index 4eafaf7d42135ab7b080b1645980c4e5eb89f0d2..ca9141c6be04dd29ba1b3bb72e1ee780d84a1dee 100644 (file)
--- a/src/common/config_opts.h
+++ b/src/common/config_opts.h
@@ -375,6 +375,7 @@ OPTION(client_trace, OPT_STR, "")
 OPTION(client_readahead_min, OPT_LONGLONG, 128*1024)  // readahead at _least_ this much.
 OPTION(client_readahead_max_bytes, OPT_LONGLONG, 0)  // default unlimited
 OPTION(client_readahead_max_periods, OPT_LONGLONG, 4)  // as multiple of file layout period (object size * num stripes)
+OPTION(client_reconnect_stale, OPT_BOOL, false)  // automatically reconnect stale session
 OPTION(client_snapdir, OPT_STR, ".snap")
 OPTION(client_mountpoint, OPT_STR, "/")
 OPTION(client_mount_uid, OPT_INT, -1)