From 4c1f8e17843d8b5e05474575ab7d8a0984b19af3 Mon Sep 17 00:00:00 2001
From: Etienne Dechamps <etienne.dechamps@ovh.net>
Date: Tue, 25 Sep 2012 14:28:53 +0200
Subject: [PATCH] TRIM cache devices on export and remove.

With this patch:
 - L2ARC vdevs are trimmed on export, except the labels which are
  preserved to keep import working.
 - L2ARC vdevs are trimmed entirely on remove and pool destroy.
---
 include/sys/arc.h       | 2 +-
 include/sys/zio.h       | 2 +-
 module/zfs/arc.c        | 7 ++++++-
 module/zfs/spa.c        | 7 +++++--
 module/zfs/trim_map.c   | 2 +-
 module/zfs/vdev_label.c | 2 +-
 module/zfs/zio.c        | 6 ++++--
 7 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/include/sys/arc.h b/include/sys/arc.h
index dd9b128bc1ea..7096216823bb 100644
--- a/include/sys/arc.h
+++ b/include/sys/arc.h
@@ -143,7 +143,7 @@ void arc_fini(void);
  */
 
 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
-void l2arc_remove_vdev(vdev_t *vd);
+void l2arc_remove_vdev(vdev_t *vd, int trim);
 boolean_t l2arc_vdev_present(vdev_t *vd);
 void l2arc_init(void);
 void l2arc_fini(void);
diff --git a/include/sys/zio.h b/include/sys/zio.h
index 8cb939d46916..6d15edbea55e 100644
--- a/include/sys/zio.h
+++ b/include/sys/zio.h
@@ -517,7 +517,7 @@ extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
 extern void zio_flush(zio_t *zio, vdev_t *vd);
 extern zio_t *zio_trim(zio_t *zio, spa_t *spa, vdev_t *vd,
-    uint64_t offset, uint64_t size);
+    uint64_t offset, uint64_t size, enum zio_flag flags);
 extern void zio_shrink(zio_t *zio, uint64_t size);
 
 extern int zio_wait(zio_t *zio);
diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index 203586193cf1..70e9f530a359 100644
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -4856,7 +4856,7 @@ l2arc_add_vdev(spa_t *spa, vdev_t *vd)
  * Remove a vdev from the L2ARC.
  */
 void
-l2arc_remove_vdev(vdev_t *vd)
+l2arc_remove_vdev(vdev_t *vd, int trim)
 {
 	l2arc_dev_t *dev, *nextdev, *remdev = NULL;
 
@@ -4886,6 +4886,11 @@ l2arc_remove_vdev(vdev_t *vd)
 	 */
 	l2arc_evict(remdev, 0, B_TRUE);
 	list_destroy(remdev->l2ad_buflist);
+	if (trim && spa_writeable(vd->vdev_spa))
+		zio_wait(zio_trim(NULL, vd->vdev_spa, vd,
+		    remdev->l2ad_start,
+		    remdev->l2ad_end - remdev->l2ad_start,
+		    ZIO_FLAG_CONFIG_WRITER));
 	kmem_free(remdev->l2ad_buflist, sizeof (list_t));
 	kmem_free(remdev, sizeof (l2arc_dev_t));
 }
diff --git a/module/zfs/spa.c b/module/zfs/spa.c
index 16df287acb7f..581924d79c97 100644
--- a/module/zfs/spa.c
+++ b/module/zfs/spa.c
@@ -1311,7 +1311,10 @@ spa_load_l2cache(spa_t *spa)
 
 			if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
 			    pool != 0ULL && l2arc_vdev_present(vd))
-				l2arc_remove_vdev(vd);
+				l2arc_remove_vdev(vd, 0);
+			if (!zfs_notrim && spa_writeable(spa))
+				zio_wait(zio_trim(NULL, spa, vd, 0,
+				    vd->vdev_psize, ZIO_FLAG_CONFIG_WRITER));
 			vdev_clear_stats(vd);
 			vdev_free(vd);
 		}
@@ -2935,7 +2938,7 @@ spa_l2cache_drop(spa_t *spa)
 
 		if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
 		    pool != 0ULL && l2arc_vdev_present(vd))
-			l2arc_remove_vdev(vd);
+			l2arc_remove_vdev(vd, !zfs_notrim);
 	}
 }
 
diff --git a/module/zfs/trim_map.c b/module/zfs/trim_map.c
index ea6116868a97..3ae4eb89b172 100644
--- a/module/zfs/trim_map.c
+++ b/module/zfs/trim_map.c
@@ -392,7 +392,7 @@ trim_map_vdev_commit(spa_t *spa, zio_t *zio, vdev_t *vd)
 		avl_remove(&tm->tm_queued_frees, ts);
 		avl_add(&tm->tm_inflight_frees, ts);
 		zio_nowait(zio_trim(zio, spa, vd, ts->ts_start,
-		    ts->ts_end - ts->ts_start));
+		    ts->ts_end - ts->ts_start, 0));
 	}
 	mutex_exit(&tm->tm_lock);
 }
diff --git a/module/zfs/vdev_label.c b/module/zfs/vdev_label.c
index aeab374b8c4f..413cc3fa1759 100644
--- a/module/zfs/vdev_label.c
+++ b/module/zfs/vdev_label.c
@@ -697,7 +697,7 @@ vdev_label_init(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason)
 	 */
 	if (!zfs_notrim && (reason == VDEV_LABEL_CREATE ||
 	    reason == VDEV_LABEL_SPARE || reason == VDEV_LABEL_L2CACHE))
-		zio_wait(zio_trim(NULL, spa, vd, 0, vd->vdev_psize));
+		zio_wait(zio_trim(NULL, spa, vd, 0, vd->vdev_psize, 0));
 
 	/*
 	 * Initialize its label.
diff --git a/module/zfs/zio.c b/module/zfs/zio.c
index 5ae6ff4f1f24..d24ec3480274 100644
--- a/module/zfs/zio.c
+++ b/module/zfs/zio.c
@@ -982,14 +982,16 @@ zio_flush(zio_t *zio, vdev_t *vd)
 }
 
 zio_t *
-zio_trim(zio_t *zio, spa_t *spa, vdev_t *vd, uint64_t offset, uint64_t size)
+zio_trim(zio_t *zio, spa_t *spa, vdev_t *vd, uint64_t offset, uint64_t size,
+    enum zio_flag flags)
 {
 
 	ASSERT(vd->vdev_ops->vdev_op_leaf);
 
 	return zio_ioctl(zio, spa, vd, DKIOCTRIM, offset, size,
 	    NULL, NULL, ZIO_PRIORITY_TRIM,
-	    ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY);
+	    ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY
+	    | flags);
 }
 
 void