Multipath autoreplace, control enclosure LEDs, event rate limiting

1. Enable multipath autoreplace support for FMA.

This extends FMA autoreplace to work with multipath disks.  This
requires libdevmapper to be installed at build time.

2. Turn on/off fault LEDs when VDEVs become degraded/faulted/online

Set ZED_USE_ENCLOSURE_LEDS=1 in zed.rc to have ZED turn on/off the enclosure
LED for a drive when a drive becomes FAULTED/DEGRADED.  Your enclosure must
be supported by the Linux SES driver for this to work.  The enclosure LED
scripts work for multipath devices as well.  The scripts will clear the LED
when the fault is cleared.

3. Rate limit ZIO delay and checksum events so as not to flood ZED

ZIO delay and checksum events are rate limited to 5/sec in the zfs module.

Reviewed-by: Richard Laager <[email protected]>
Reviewed by: Don Brady <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Tony Hutter <[email protected]>
Closes #2449 
Closes #3017 
Closes #5159 

1 files changed, 20 insertions, 9 deletions

diff --git a/module/zfs/vdev.c b/module/zfs/vdev.c
index 5ff5cf3b1..f7e91430f 100644
--- a/module/zfs/vdev.c
+++ b/module/zfs/vdev.c
@@ -44,6 +44,7 @@
 #include <sys/zil.h>
 #include <sys/dsl_scan.h>
 #include <sys/zvol.h>
+#include <sys/zfs_ratelimit.h>
 
 /*
  * When a vdev is added, it will be divided into approximately (but no
@@ -346,12 +347,21 @@ vdev_alloc_common(spa_t *spa, uint_t id, uint64_t guid, vdev_ops_t *ops)
 	vd->vdev_state = VDEV_STATE_CLOSED;
 	vd->vdev_ishole = (ops == &vdev_hole_ops);
 
+	/*
+	 * Initialize rate limit structs for events.  We rate limit ZIO delay
+	 * and checksum events so that we don't overwhelm ZED with thousands
+	 * of events when a disk is acting up.
+	 */
+	zfs_ratelimit_init(&vd->vdev_delay_rl, DELAYS_PER_SECOND, 1);
+	zfs_ratelimit_init(&vd->vdev_checksum_rl, CHECKSUMS_PER_SECOND, 1);
+
 	list_link_init(&vd->vdev_config_dirty_node);
 	list_link_init(&vd->vdev_state_dirty_node);
 	mutex_init(&vd->vdev_dtl_lock, NULL, MUTEX_NOLOCKDEP, NULL);
 	mutex_init(&vd->vdev_stat_lock, NULL, MUTEX_DEFAULT, NULL);
 	mutex_init(&vd->vdev_probe_lock, NULL, MUTEX_DEFAULT, NULL);
 	mutex_init(&vd->vdev_queue_lock, NULL, MUTEX_DEFAULT, NULL);
+
 	for (t = 0; t < DTL_TYPES; t++) {
 		vd->vdev_dtl[t] = range_tree_create(NULL, NULL,
 		    &vd->vdev_dtl_lock);
@@ -2221,7 +2231,6 @@ vdev_load(vdev_t *vd)
 	    vdev_metaslab_init(vd, 0) != 0))
 		vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
 		    VDEV_AUX_CORRUPT_DATA);
-
 	/*
 	 * If this is a leaf vdev, load its DTL.
 	 */
@@ -3458,15 +3467,17 @@ vdev_set_state(vdev_t *vd, boolean_t isopen, vdev_state_t state, vdev_aux_t aux)
 	/*
 	 * Notify ZED of any significant state-change on a leaf vdev.
 	 *
-	 * We ignore transitions from a closed state to healthy unless
-	 * the parent was degraded.
 	 */
-	if (vd->vdev_ops->vdev_op_leaf &&
-	    ((save_state > VDEV_STATE_CLOSED) ||
-	    (vd->vdev_state < VDEV_STATE_HEALTHY) ||
-	    (vd->vdev_parent != NULL &&
-	    vd->vdev_parent->vdev_prevstate == VDEV_STATE_DEGRADED))) {
-		zfs_post_state_change(spa, vd, save_state);
+	if (vd->vdev_ops->vdev_op_leaf) {
+		/* preserve original state from a vdev_reopen() */
+		if ((vd->vdev_prevstate != VDEV_STATE_UNKNOWN) &&
+		    (vd->vdev_prevstate != vd->vdev_state) &&
+		    (save_state <= VDEV_STATE_CLOSED))
+			save_state = vd->vdev_prevstate;
+
+		/* filter out state change due to initial vdev_open */
+		if (save_state > VDEV_STATE_CLOSED)
+			zfs_post_state_change(spa, vd, save_state);
 	}
 
 	if (!isopen && vd->vdev_parent)