1 files changed, 83 insertions, 89 deletions

diff --git a/module/zfs/zil.c b/module/zfs/zil.c
index 83fef0d87..53d9d9bf7 100644
--- a/module/zfs/zil.c
+++ b/module/zfs/zil.c
@@ -19,12 +19,13 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
 #include <sys/zfs_context.h>
 #include <sys/spa.h>
+#include <sys/spa_impl.h>
 #include <sys/dmu.h>
 #include <sys/zap.h>
 #include <sys/arc.h>
@@ -471,34 +472,22 @@ zil_destroy(zilog_t *zilog, boolean_t keep_first)
 }
 
 /*
- * zil_rollback_destroy() is only called by the rollback code.
- * We already have a syncing tx. Rollback has exclusive access to the
- * dataset, so we don't have to worry about concurrent zil access.
- * The actual freeing of any log blocks occurs in zil_sync() later in
- * this txg syncing phase.
+ * return true if the initial log block is not valid
  */
-void
-zil_rollback_destroy(zilog_t *zilog, dmu_tx_t *tx)
+static boolean_t
+zil_empty(zilog_t *zilog)
 {
 	const zil_header_t *zh = zilog->zl_header;
-	uint64_t txg;
+	arc_buf_t *abuf = NULL;
 
 	if (BP_IS_HOLE(&zh->zh_log))
-		return;
+		return (B_TRUE);
 
-	txg = dmu_tx_get_txg(tx);
-	ASSERT3U(zilog->zl_destroy_txg, <, txg);
-	zilog->zl_destroy_txg = txg;
-	zilog->zl_keep_first = B_FALSE;
+	if (zil_read_log_block(zilog, &zh->zh_log, &abuf) != 0)
+		return (B_TRUE);
 
-	/*
-	 * Ensure there's no outstanding ZIL IO.  No lwbs or just the
-	 * unused one that allocated in advance is ok.
-	 */
-	ASSERT(zilog->zl_lwb_list.list_head.list_next ==
-	    zilog->zl_lwb_list.list_head.list_prev);
-	(void) zil_parse(zilog, zil_free_log_block, zil_free_log_record,
-	    tx, zh->zh_claim_txg);
+	VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1);
+	return (B_FALSE);
 }
 
 int
@@ -520,6 +509,30 @@ zil_claim(char *osname, void *txarg)
 	zilog = dmu_objset_zil(os);
 	zh = zil_header_in_syncing_context(zilog);
 
+	if (zilog->zl_spa->spa_log_state == SPA_LOG_CLEAR) {
+		if (!BP_IS_HOLE(&zh->zh_log))
+			zio_free_blk(zilog->zl_spa, &zh->zh_log, first_txg);
+		BP_ZERO(&zh->zh_log);
+		dsl_dataset_dirty(dmu_objset_ds(os), tx);
+	}
+
+	/*
+	 * Record here whether the zil has any records to replay.
+	 * If the header block pointer is null or the block points
+	 * to the stubby then we know there are no valid log records.
+	 * We use the header to store this state as the the zilog gets
+	 * freed later in dmu_objset_close().
+	 * The flags (and the rest of the header fields) are cleared in
+	 * zil_sync() as a result of a zil_destroy(), after replaying the log.
+	 *
+	 * Note, the intent log can be empty but still need the
+	 * stubby to be claimed.
+	 */
+	if (!zil_empty(zilog)) {
+		zh->zh_flags |= ZIL_REPLAY_NEEDED;
+		dsl_dataset_dirty(dmu_objset_ds(os), tx);
+	}
+
 	/*
 	 * Claim all log blocks if we haven't already done so, and remember
 	 * the highest claimed sequence number.  This ensures that if we can
@@ -587,36 +600,6 @@ zil_check_log_chain(char *osname, void *txarg)
 	return (error);
 }
 
-/*
- * Clear a log chain
- */
-/* ARGSUSED */
-int
-zil_clear_log_chain(char *osname, void *txarg)
-{
-	zilog_t *zilog;
-	zil_header_t *zh;
-	objset_t *os;
-	dmu_tx_t *tx;
-	int error;
-
-	error = dmu_objset_open(osname, DMU_OST_ANY, DS_MODE_USER, &os);
-	if (error) {
-		cmn_err(CE_WARN, "can't open objset for %s", osname);
-		return (0);
-	}
-
-	zilog = dmu_objset_zil(os);
-	tx = dmu_tx_create(zilog->zl_os);
-	(void) dmu_tx_assign(tx, TXG_WAIT);
-	zh = zil_header_in_syncing_context(zilog);
-	BP_ZERO(&zh->zh_log);
-	dsl_dataset_dirty(dmu_objset_ds(os), tx);
-	dmu_tx_commit(tx);
-	dmu_objset_close(os);
-	return (0);
-}
-
 static int
 zil_vdev_compare(const void *x1, const void *x2)
 {
@@ -719,18 +702,26 @@ zil_lwb_write_done(zio_t *zio)
 	ASSERT(zio->io_bp->blk_fill == 0);
 
 	/*
-	 * Now that we've written this log block, we have a stable pointer
-	 * to the next block in the chain, so it's OK to let the txg in
-	 * which we allocated the next block sync.
+	 * Ensure the lwb buffer pointer is cleared before releasing
+	 * the txg. If we have had an allocation failure and
+	 * the txg is waiting to sync then we want want zil_sync()
+	 * to remove the lwb so that it's not picked up as the next new
+	 * one in zil_commit_writer(). zil_sync() will only remove
+	 * the lwb if lwb_buf is null.
 	 */
-	txg_rele_to_sync(&lwb->lwb_txgh);
-
 	zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
 	mutex_enter(&zilog->zl_lock);
 	lwb->lwb_buf = NULL;
 	if (zio->io_error)
 		zilog->zl_log_error = B_TRUE;
 	mutex_exit(&zilog->zl_lock);
+
+	/*
+	 * Now that we've written this log block, we have a stable pointer
+	 * to the next block in the chain, so it's OK to let the txg in
+	 * which we allocated the next block sync.
+	 */
+	txg_rele_to_sync(&lwb->lwb_txgh);
 }
 
 /*
@@ -752,9 +743,9 @@ zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb)
 	}
 	if (lwb->lwb_zio == NULL) {
 		lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa,
-		    0, &lwb->lwb_blk, lwb->lwb_buf,
-		    lwb->lwb_sz, zil_lwb_write_done, lwb,
-		    ZIO_PRIORITY_LOG_WRITE, ZIO_FLAG_CANFAIL, &zb);
+		    0, &lwb->lwb_blk, lwb->lwb_buf, lwb->lwb_sz,
+		    zil_lwb_write_done, lwb, ZIO_PRIORITY_LOG_WRITE,
+		    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &zb);
 	}
 }
 
@@ -1040,7 +1031,7 @@ zil_clean(zilog_t *zilog)
 	if ((itx != NULL) &&
 	    (itx->itx_lr.lrc_txg <= spa_last_synced_txg(zilog->zl_spa))) {
 		(void) taskq_dispatch(zilog->zl_clean_taskq,
-		    (void (*)(void *))zil_itx_clean, zilog, TQ_NOSLEEP);
+		    (task_func_t *)zil_itx_clean, zilog, TQ_SLEEP);
 	}
 	mutex_exit(&zilog->zl_lock);
 }
@@ -1216,6 +1207,13 @@ zil_sync(zilog_t *zilog, dmu_tx_t *tx)
 	spa_t *spa = zilog->zl_spa;
 	lwb_t *lwb;
 
+	/*
+	 * We don't zero out zl_destroy_txg, so make sure we don't try
+	 * to destroy it twice.
+	 */
+	if (spa_sync_pass(spa) != 1)
+		return;
+
 	mutex_enter(&zilog->zl_lock);
 
 	ASSERT(zilog->zl_stop_sync == 0);
@@ -1226,7 +1224,6 @@ zil_sync(zilog_t *zilog, dmu_tx_t *tx)
 		blkptr_t blk = zh->zh_log;
 
 		ASSERT(list_head(&zilog->zl_lwb_list) == NULL);
-		ASSERT(spa_sync_pass(spa) == 1);
 
 		bzero(zh, sizeof (zil_header_t));
 		bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq));
@@ -1245,12 +1242,7 @@ zil_sync(zilog_t *zilog, dmu_tx_t *tx)
 		}
 	}
 
-	for (;;) {
-		lwb = list_head(&zilog->zl_lwb_list);
-		if (lwb == NULL) {
-			mutex_exit(&zilog->zl_lock);
-			return;
-		}
+	while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
 		zh->zh_log = lwb->lwb_blk;
 		if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg)
 			break;
@@ -1344,25 +1336,6 @@ zil_free(zilog_t *zilog)
 }
 
 /*
- * return true if the initial log block is not valid
- */
-static boolean_t
-zil_empty(zilog_t *zilog)
-{
-	const zil_header_t *zh = zilog->zl_header;
-	arc_buf_t *abuf = NULL;
-
-	if (BP_IS_HOLE(&zh->zh_log))
-		return (B_TRUE);
-
-	if (zil_read_log_block(zilog, &zh->zh_log, &abuf) != 0)
-		return (B_TRUE);
-
-	VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1);
-	return (B_FALSE);
-}
-
-/*
  * Open an intent log.
  */
 zilog_t *
@@ -1417,7 +1390,7 @@ zil_suspend(zilog_t *zilog)
 	const zil_header_t *zh = zilog->zl_header;
 
 	mutex_enter(&zilog->zl_lock);
-	if (zh->zh_claim_txg != 0) {		/* unplayed log */
+	if (zh->zh_flags & ZIL_REPLAY_NEEDED) {		/* unplayed log */
 		mutex_exit(&zilog->zl_lock);
 		return (EBUSY);
 	}
@@ -1601,7 +1574,7 @@ zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE])
 	const zil_header_t *zh = zilog->zl_header;
 	zil_replay_arg_t zr;
 
-	if (zil_empty(zilog)) {
+	if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) {
 		zil_destroy(zilog, B_TRUE);
 		return;
 	}
@@ -1671,3 +1644,24 @@ out:
 	mutex_exit(&zilog->zl_lock);
 	return (ret);
 }
+
+/* ARGSUSED */
+int
+zil_vdev_offline(char *osname, void *arg)
+{
+	objset_t *os;
+	zilog_t *zilog;
+	int error;
+
+	error = dmu_objset_open(osname, DMU_OST_ANY, DS_MODE_USER, &os);
+	if (error)
+		return (error);
+
+	zilog = dmu_objset_zil(os);
+	if (zil_suspend(zilog) != 0)
+		error = EEXIST;
+	else
+		zil_resume(zilog);
+	dmu_objset_close(os);
+	return (error);
+}