Dan Williams: mdmon: record sync_completed directly to the metadata

[Martin F. Krafft]

Module: mdadm
Branch: fixes/udev-blkid
Commit: 4f0a7acc9a0a93d39b66b29e374f9a5edd173047
URL:    http://git.debian.org/?p=pkg-mdadm/mdadm.git;a=commit;h=4f0a7acc9a0a93d39b66b29e374f9a5edd173047

Author: Dan Williams <dan.j.williams at intel.com>
Date:   Tue Jun 15 18:41:57 2010 -0700

mdmon: record sync_completed directly to the metadata

When sync_action is idle mdmon takes the latest value of md/resync_start
or md/<dev>/recovery_start to record the resync/rebuild checkpoint in
the metadata.  However, now that mdmon is reading sync_completed there
is no longer a need to wait for, or force an idle event to take a
checkpoint.

Simply update the forward progress of ->last_checkpoint at every wakeup
event and force it to be recorded at least every 1/16th array-size
interval.  It may be recorded more frequently if a ->set_array_state()
event occurs.

This also cleans up some confusion in handling the dual-rebuild case.
If more than one spare has been activated the kernel starts the rebuild
at the lowest recovery offset, so we do not need to worry about
min_recovery_start().

Signed-off-by: Dan Williams <dan.j.williams at intel.com>

---

 monitor.c     |   10 +++++++---
 super-intel.c |    7 ++-----
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/monitor.c b/monitor.c
index 12f8d3e..59b4181 100644
--- a/monitor.c
+++ b/monitor.c
@@ -334,10 +334,14 @@ static int read_and_act(struct active_array *a)
 	 */
 	if (sync_completed > a->last_checkpoint &&
 	    sync_completed - a->last_checkpoint > a->info.component_size >> 4 &&
-	    a->curr_action > reshape && a->next_action == bad_action) {
+	    a->curr_action > reshape) {
+		/* A (non-reshape) sync_action has reached a checkpoint.
+		 * Record the updated position in the metadata
+		 */
+		a->last_checkpoint = sync_completed;
+		a->container->ss->set_array_state(a, a->curr_state <= clean);
+	} else if (sync_completed > a->last_checkpoint)
 		a->last_checkpoint = sync_completed;
-		a->next_action = idle;
-	}
 
 	a->container->ss->sync_metadata(a->container);
 	dprintf("%s(%d): state:%s action:%s next(", __func__, a->info.container_member,
diff --git a/super-intel.c b/super-intel.c
index b88e6a9..3bd041a 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -4415,14 +4415,11 @@ static int imsm_set_array_state(struct active_array *a, int consistent)
 
 	/* check if we can update curr_migr_unit from resync_start, recovery_start */
 	blocks_per_unit = blocks_per_migr_unit(dev);
-	if (blocks_per_unit && failed <= 1) {
+	if (blocks_per_unit) {
 		__u32 units32;
 		__u64 units;
 
-		if (migr_type(dev) == MIGR_REBUILD)
-			units = min_recovery_start(&a->info) / blocks_per_unit;
-		else
-			units = a->info.resync_start / blocks_per_unit;
+		units = a->last_checkpoint / blocks_per_unit;
 		units32 = units;
 
 		/* check that we did not overflow 32-bits, and that