[lustre-devel] [PATCH 3/8] lustre: fld: resend seq lookup RPC if it is on LWP
James Simmons
jsimmons at infradead.org
Wed Jul 24 19:44:02 PDT 2019
From: wang di <di.wang at intel.com>
Because Light Weight connection might be evicted after
restart, then cause inflight RPC fails, to avoid this,
we need resend seq lookup RPC.
remove "-f" from "stop mdt" in sanity 17m, so umount can
keep the the connection, and otherwise the OSP might be
evicted.
WC-bug-id: https://jira.whamcloud.com/browse/LU-4571
Lustre-commit: cf7f66d87e52293535cde6e8cc7386e6c1bdfa46
Signed-off-by: wang di <di.wang at intel.com>
Reviewed-on: http://review.whamcloud.com/9106
Reviewed-by: Andreas Dilger <adilger at whamcloud.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong at gmail.com>
Reviewed-by: Niu Yawei <yawei.niu at intel.com>
---
fs/lustre/fld/fld_request.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/fs/lustre/fld/fld_request.c b/fs/lustre/fld/fld_request.c
index 248fffa..ec45ea6 100644
--- a/fs/lustre/fld/fld_request.c
+++ b/fs/lustre/fld/fld_request.c
@@ -314,6 +314,7 @@ int fld_client_rpc(struct obd_export *exp,
LASSERT(exp);
+again:
imp = class_exp2cliimp(exp);
switch (fld_op) {
case FLD_QUERY:
@@ -329,8 +330,15 @@ int fld_client_rpc(struct obd_export *exp,
op = req_capsule_client_get(&req->rq_pill, &RMF_FLD_OPC);
*op = FLD_LOOKUP;
- if (imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS)
+ /* For MDS_MDS seq lookup, it will always use LWP connection,
+ * but LWP will be evicted after restart, so cause the error.
+ * so we will set no_delay for seq lookup request, once the
+ * request fails because of the eviction. always retry here
+ */
+ if (imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS) {
req->rq_allow_replay = 1;
+ req->rq_no_delay = 1;
+ }
break;
case FLD_READ:
req = ptlrpc_request_alloc_pack(imp, &RQF_FLD_READ,
@@ -358,8 +366,19 @@ int fld_client_rpc(struct obd_export *exp,
obd_get_request_slot(&exp->exp_obd->u.cli);
rc = ptlrpc_queue_wait(req);
obd_put_request_slot(&exp->exp_obd->u.cli);
- if (rc)
+ if (rc != 0) {
+ if (rc == -EWOULDBLOCK) {
+ /* For no_delay req(see above), EWOULDBLOCK means the
+ * connection is being evicted, but this seq lookup
+ * should not return error, since it would cause
+ * unecessary failure of the application, instead
+ * it should retry here
+ */
+ ptlrpc_req_finished(req);
+ goto again;
+ }
goto out_req;
+ }
if (fld_op == FLD_QUERY) {
prange = req_capsule_server_get(&req->rq_pill, &RMF_FLD_MDFLD);
--
1.8.3.1
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