[lustre-devel] [PATCH 10/20] lustre: ptlrpc: add assert for ptlrpc_service_purge_all

[James Simmons]

From: Etienne AUJAMES <etienne.aujames at cea.fr>

ptlrpc_service_purge_all() calls ptlrpc_server_request_get() with
"force=true" to purge all active requests before stopping an NRS
policy (when unregistering a service).

"force" mode should always return a request if a pending request is
present in the NRS policy.

BUG: unable to handle kernel NULL pointer dereference at
0000000000000114
IP: [<ffffffffc0d9e965>] ptlrpc_nrs_req_stop_nolock+0x5/0x150
.....
? ptlrpc_server_finish_active_request+0x2b/0x140 [ptlrpc]
ptlrpc_service_purge_all+0x137/0x920 [ptlrpc]
ptlrpc_unregister_service+0xe7/0x6f0 [ptlrpc]
ost_cleanup+0x52/0x1b0 [ost]
class_free_dev+0x21d/0x720 [obdclass]
class_export_put+0x1f0/0x2c0 [obdclass]
class_unlink_export+0x135/0x170 [obdclass]
class_decref+0x80/0x160 [obdclass]
class_detach+0x1b3/0x2e0 [obdclass]
class_process_config+0x1a38/0x2830 [obdclass]
? complete+0x4a/0x60
? list_del+0xd/0x30
? wait_for_completion+0x4e/0x140
class_manual_cleanup+0x1e0/0x710 [obdclass]
server_stop_servers+0xd5/0x160 [obdclass]
server_put_super+0x12d/0xd00 [obdclass]
generic_shutdown_super+0x6d/0x100

WC-bug-id: https://jira.whamcloud.com/browse/LU-16144
Lustre-commit: 1bba7dd425d3fc9ef3 ("LU-16144 nrs: implement force mode for nrs_tbf_req_get()")
Signed-off-by: Etienne AUJAMES <etienne.aujames at cea.fr>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/48494
Reviewed-by: Nikitas Angelinas <nikitas.angelinas at hpe.com>
Reviewed-by: Andreas Dilger <adilger at whamcloud.com>
Reviewed-by: Oleg Drokin <green at whamcloud.com>
Signed-off-by: James Simmons <jsimmons at infradead.org>
---
 fs/lustre/ptlrpc/service.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/lustre/ptlrpc/service.c b/fs/lustre/ptlrpc/service.c
index 59fe1f4aa18f..aaf7529e25f3 100644
--- a/fs/lustre/ptlrpc/service.c
+++ b/fs/lustre/ptlrpc/service.c
@@ -2939,6 +2939,7 @@ ptlrpc_service_purge_all(struct ptlrpc_service *svc)
 
 		while (ptlrpc_server_request_pending(svcpt, true)) {
 			req = ptlrpc_server_request_get(svcpt, true);
+			LASSERT(req);
 			ptlrpc_server_finish_active_request(svcpt, req);
 		}
 
-- 
2.27.0