X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Ftxg.c;h=6e64adf9376e5c97a8cfb823caf796c0c9cb6b8f;hb=570827e129ed81e066e894530bbe24642f473154;hp=382a2a91c7b08b5a0c1dada5c3a0edf6cbadb15d;hpb=c28b227942b421ebdc03c9df9a012642fb517223;p=zfs.git

diff --git a/module/zfs/txg.c b/module/zfs/txg.c
index 382a2a9..6e64adf 100644
--- a/module/zfs/txg.c
+++ b/module/zfs/txg.c
@@ -166,10 +166,10 @@ txg_thread_wait(tx_state_t *tx, callb_cpr_t *cpr, kcondvar_t *cv, uint64_t time)
 	CALLB_CPR_SAFE_BEGIN(cpr);
 
 	if (time)
-		(void) cv_timedwait(cv, &tx->tx_sync_lock,
+		(void) cv_timedwait_interruptible(cv, &tx->tx_sync_lock,
 		    ddi_get_lbolt() + time);
 	else
-		cv_wait(cv, &tx->tx_sync_lock);
+		cv_wait_interruptible(cv, &tx->tx_sync_lock);
 
 	CALLB_CPR_SAFE_END(cpr, &tx->tx_sync_lock);
 }
@@ -350,6 +350,20 @@ txg_dispatch_callbacks(dsl_pool_t *dp, uint64_t txg)
 	}
 }
 
+/*
+ * Wait for pending commit callbacks of already-synced transactions to finish
+ * processing.
+ * Calling this function from within a commit callback will deadlock.
+ */
+void
+txg_wait_callbacks(dsl_pool_t *dp)
+{
+	tx_state_t *tx = &dp->dp_tx;
+
+	if (tx->tx_commit_cb_taskq != NULL)
+		taskq_wait(tx->tx_commit_cb_taskq);
+}
+
 static void
 txg_sync_thread(dsl_pool_t *dp)
 {
@@ -358,6 +372,19 @@ txg_sync_thread(dsl_pool_t *dp)
 	callb_cpr_t cpr;
 	uint64_t start, delta;
 
+#ifdef _KERNEL
+	/*
+	 * Disable the normal reclaim path for the txg_sync thread.  This
+	 * ensures the thread will never enter dmu_tx_assign() which can
+	 * otherwise occur due to direct reclaim.  If this is allowed to
+	 * happen the system can deadlock.  Direct reclaim call path:
+	 *
+	 *   ->shrink_icache_memory->prune_icache->dispose_list->
+	 *   clear_inode->zpl_clear_inode->zfs_inactive->dmu_tx_assign
+	 */
+	current->flags |= PF_MEMALLOC;
+#endif /* _KERNEL */
+
 	txg_thread_enter(tx, &cpr);
 
 	start = delta = 0;
@@ -479,7 +506,7 @@ void
 txg_delay(dsl_pool_t *dp, uint64_t txg, int ticks)
 {
 	tx_state_t *tx = &dp->dp_tx;
-	int timeout = ddi_get_lbolt() + ticks;
+	clock_t timeout = ddi_get_lbolt() + ticks;
 
 	/* don't delay if this txg could transition to quiesing immediately */
 	if (tx->tx_open_txg > txg ||
@@ -497,6 +524,8 @@ txg_delay(dsl_pool_t *dp, uint64_t txg, int ticks)
 		(void) cv_timedwait(&tx->tx_quiesce_more_cv, &tx->tx_sync_lock,
 		    timeout);
 
+	DMU_TX_STAT_BUMP(dmu_tx_delay);
+
 	mutex_exit(&tx->tx_sync_lock);
 }
 
@@ -735,6 +764,7 @@ EXPORT_SYMBOL(txg_register_callbacks);
 EXPORT_SYMBOL(txg_delay);
 EXPORT_SYMBOL(txg_wait_synced);
 EXPORT_SYMBOL(txg_wait_open);
+EXPORT_SYMBOL(txg_wait_callbacks);
 EXPORT_SYMBOL(txg_stalled);
 EXPORT_SYMBOL(txg_sync_waiting);
 #endif