LU-1813 osc: osc_lock_unuse() race

The lock may have been released by upper layer so the cl_unuse_try()
in osc_lock_upcall() will release the dlm lock instead of crashing.

Signed-off-by: Jinshan Xiong <jinshan.xiong@whamcloud.com>
Change-Id: Ie1c3f8d2ba8b227e42d08b1631651c5834cbac25
Reviewed-on: http://review.whamcloud.com/3895
Tested-by: Hudson
Reviewed-by: Lai Siyao <laisiyao@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: wangdi <di.wang@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/obdclass/cl_page.c b/lustre/obdclass/cl_page.c
index 1266c79..b2cecd8 100644 (file)
--- a/lustre/obdclass/cl_page.c
+++ b/lustre/obdclass/cl_page.c
@@ -1358,13 +1358,6 @@ void cl_page_completion(const struct lu_env *env,
                 pg->cp_sync_io = NULL;
                 cl_sync_io_note(anchor, ioret);
         }
                 pg->cp_sync_io = NULL;
                 cl_sync_io_note(anchor, ioret);
         }

-
-        /* Don't assert the page writeback bit here because the lustre file
-         * may be as a backend of swap space. in this case, the page writeback
-         * is set by VM, and obvious we shouldn't clear it at all. Fortunately
-         * this type of pages are all TRANSIENT pages. */
-        KLASSERT(ergo(pg->cp_type == CPT_CACHEABLE,
-                      !PageWriteback(cl_page_vmpage(env, pg))));

         EXIT;
 }
 EXPORT_SYMBOL(cl_page_completion);
         EXIT;
 }
 EXPORT_SYMBOL(cl_page_completion);

diff --git a/lustre/osc/osc_lock.c b/lustre/osc/osc_lock.c
index a4b9be0..ffcfdf7 100644 (file)
--- a/lustre/osc/osc_lock.c
+++ b/lustre/osc/osc_lock.c
@@ -200,11 +200,13 @@ static int osc_lock_unuse(const struct lu_env *env,
                 LASSERT(!ols->ols_hold);
                 LASSERT(ols->ols_agl);
                 return 0;
                 LASSERT(!ols->ols_hold);
                 LASSERT(ols->ols_agl);
                 return 0;

+       case OLS_UPCALL_RECEIVED:
+               osc_lock_unhold(ols);

        case OLS_ENQUEUED:
        case OLS_ENQUEUED:

-        case OLS_UPCALL_RECEIVED:
-                LASSERT(!ols->ols_hold);
-                ols->ols_state = OLS_NEW;
-                return 0;
+               LASSERT(!ols->ols_hold);
+               osc_lock_detach(env, ols);
+               ols->ols_state = OLS_NEW;
+               return 0;

         case OLS_GRANTED:
                 LASSERT(!ols->ols_glimpse);
                 LASSERT(ols->ols_hold);
         case OLS_GRANTED:
                 LASSERT(!ols->ols_glimpse);
                 LASSERT(ols->ols_hold);