From: NeilBrown <neilb@suse.de>
Date: Tue, 11 Jan 2011 23:34:44 +0000 (+1100)
Subject: Fix calculations for max_progress and completed.
X-Git-Tag: mdadm-3.2~108
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=92d1991fffcc56c7b7ce4667f847559e2df23449;p=thirdparty%2Fmdadm.git

Fix calculations for max_progress and completed.


'sync_completed' can sometimes have a value which is slightly high.
So round-down relevant values to new-chunk size and that is what we
want.

Subtract from component_size after scaling down rather than before as
that is easier.
Make sure max_progress never goes negative when reshaping backwards.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/Grow.c b/Grow.c
index 708a6c74..7c7fa647 100644
--- a/Grow.c
+++ b/Grow.c
@@ -2409,14 +2409,20 @@ int progress_reshape(struct mdinfo *info, struct reshape *reshape,
 	 * At the same time we convert wait_point to a similar number
 	 * for comparing against sync_completed.
 	 */
-	if (!advancing) {
-		max_progress = info->component_size * reshape->after.data_disks
-			- max_progress;
-		wait_point = info->component_size * reshape->after.data_disks
-			- wait_point;
-	}
+	/* scale down max_progress to per_disk */
 	max_progress /= reshape->after.data_disks;
+	/* Round to chunk size as some kernels give an erroneously high number */
+	max_progress /= info->new_chunk/512;
+	max_progress *= info->new_chunk/512;
+	/* Limit progress to the whole device */
+	if (max_progress > info->component_size)
+		max_progress = info->component_size;
 	wait_point /= reshape->after.data_disks;
+	if (!advancing) {
+		/* switch from 'device offset' to 'processed block count' */
+		max_progress = info->component_size - max_progress;
+		wait_point = info->component_size - wait_point;
+	}
 
 	sysfs_set_num(info, NULL, "sync_max", max_progress);
 
@@ -2452,6 +2458,9 @@ int progress_reshape(struct mdinfo *info, struct reshape *reshape,
 			return -1;
 		}
 	}
+	/* some kernels can give an incorrectly high 'completed' number */
+	completed /= (info->new_chunk/512);
+	completed *= (info->new_chunk/512);
 	/* Convert 'completed' back in to a 'progress' number */
 	completed *= reshape->after.data_disks;
 	if (!advancing) {