[PATCH 3.18 23/27] staging: lustre: ptlrpc: skip lock if export failed

Greg Kroah-Hartman
2017-11-06T11:32:32Z

From: Alexander Boyko <alexander.boyko@seagate.com>

[ Upstream commit 4c43c27ddc461d8473cedd70f2549614641dfbc7 ]

This patch resolves IO vs eviction race.
After eviction failed export stayed at stale list,
a client had IO processing and reconnected during it.
A client sent brw rpc with last lock cookie and new connection.
The lock with failed export was found and assert was happened.
(ost_handler.c:1812:ost_prolong_lock_one())
ASSERTION( lock->l_export == opd->opd_exp ) failed:

1. Skip the lock at ldlm_handle2lock if lock export failed.
2. Validation of lock for IO was added at hpreq_check(). The lock
searching is based on granted interval tree. If server doesn`t
have a valid lock, it reply to client with ESTALE.

Signed-off-by: Alexander Boyko <alexander.boyko@seagate.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7702
Seagate-bug-id: MRP-2787
Reviewed-on: http://review.whamcloud.com/18120
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Vitaly Fertman <vitaly.fertman@seagate.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/staging/lustre/lustre/ldlm/ldlm_lock.c | 7 +++++++
drivers/staging/lustre/lustre/ptlrpc/service.c | 21 ++++++++-------------
2 files changed, 15 insertions(+), 13 deletions(-)

--- a/drivers/staging/lustre/lustre/ldlm/ldlm_lock.c
+++ b/drivers/staging/lustre/lustre/ldlm/ldlm_lock.c
@@ -573,6 +573,13 @@ struct ldlm_lock *__ldlm_handle2lock(con
if (lock == NULL)
return NULL;

+ if (lock->l_export && lock->l_export->exp_failed) {
+ CDEBUG(D_INFO, "lock export failed: lock %p, exp %p\n",
+ lock, lock->l_export);
+ LDLM_LOCK_PUT(lock);
+ return NULL;
+ }
+
/* It's unlikely but possible that someone marked the lock as
* destroyed after we did handle2object on it */
if (flags == 0 && ((lock->l_flags & LDLM_FL_DESTROYED)== 0)) {
--- a/drivers/staging/lustre/lustre/ptlrpc/service.c
+++ b/drivers/staging/lustre/lustre/ptlrpc/service.c
@@ -1506,20 +1506,15 @@ static int ptlrpc_server_hpreq_init(stru
* it may hit swab race at LU-1044. */
if (req->rq_ops->hpreq_check) {
rc = req->rq_ops->hpreq_check(req);
- /**
- * XXX: Out of all current
- * ptlrpc_hpreq_ops::hpreq_check(), only
- * ldlm_cancel_hpreq_check() can return an error code;
- * other functions assert in similar places, which seems
- * odd. What also does not seem right is that handlers
- * for those RPCs do not assert on the same checks, but
- * rather handle the error cases. e.g. see
- * ost_rw_hpreq_check(), and ost_brw_read(),
- * ost_brw_write().
+ if (rc == -ESTALE) {
+ req->rq_status = rc;
+ ptlrpc_error(req);
+ }
+ /** can only return error,
+ * 0 for normal request,
+ * or 1 for high priority request
*/
- if (rc < 0)
- return rc;
- LASSERT(rc == 0 || rc == 1);
+ LASSERT(rc <= 1);
}

spin_lock_bh(&req->rq_export->exp_rpc_lock);