Attempt to fix zil_sync race

Signed-off-by: Richard Yao <[email protected]>
openzfs · May 14, 2017 · ebbcf18 · ebbcf18
1 parent 26e0a8f
commit ebbcf18
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Showing 2 changed files with 5 additions and 7 deletions.
diff --git a/include/sys/zil_impl.h b/include/sys/zil_impl.h
@@ -129,9 +129,8 @@ struct zilog {
 	uint_t		zl_prev_blks[ZIL_PREV_BLKS]; /* size - sector rounded */
 	uint_t		zl_prev_rotor;	/* rotor for zl_prev[] */
 	txg_node_t	zl_dirty_link;	/* protected by dp_dirty_zilogs list */
-	kmutex_t	zl_writer_lock;	/* protects two fields below */
+	kmutex_t	zl_writer_lock;	/* protects writer list */
 	list_t		zl_writer_list;	/* list of writers */
-	lwb_t		*zl_last_lwb;	/* lwb from previous pipeline stage */
 };
 
 /*

diff --git a/module/zfs/zil.c b/module/zfs/zil.c
@@ -1613,12 +1613,12 @@ zil_commit_writer(zilog_t *zilog)
 				cv_wait(&prev->zilw_cv_waiter,
 				    &zilog->zl_writer_lock);
 			}
-			lwb = zilog->zl_last_lwb;
-
-		} else {
-			lwb = list_tail(&zilog->zl_lwb_list);
 		}
 
+		mutex_enter(&zilog->zl_lock);
+		lwb = list_tail(&zilog->zl_lwb_list);
+		mutex_exit(&zilog->zl_lock);
+
 		if (lwb == NULL)
 			lwb = zil_create(zilw);
 	}
@@ -1652,7 +1652,6 @@ zil_commit_writer(zilog_t *zilog)
 	/*
 	 * Signal next thread, if any, for entry into the pipeline.
 	 */
-	zilog->zl_last_lwb = lwb;
 	mutex_enter(&zilog->zl_writer_lock);
 	if (zilw->zilw_stage == 1) {
 		zilw->zilw_stage = 2;