From: NeilBrown <neilb@suse.de>
Date: Mon, 23 Mar 2015 06:36:38 +0000 (+1100)
Subject: md: don't require sync_min to be a multiple of chunk_size.
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=50c37b136a3807eda44afe16529b5af701ec49f5;p=linux-beck.git

md: don't require sync_min to be a multiple of chunk_size.

There is really no need for sync_min to be a multiple of
chunk_size, and values read from here often aren't.
That means you cannot read a value and expect to be able
to write it back later.

So remove the chunk_size check, and round down to a multiple
of 4K, to be sure everything works with 4K-sector devices.

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

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 0d8968535976..3724a29eaf0e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4427,7 +4427,6 @@ min_sync_store(struct mddev *mddev, const char *buf, size_t len)
 {
 	unsigned long long min;
 	int err;
-	int chunk;
 
 	if (kstrtoull(buf, 10, &min))
 		return -EINVAL;
@@ -4441,16 +4440,8 @@ min_sync_store(struct mddev *mddev, const char *buf, size_t len)
 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
 		goto out_unlock;
 
-	/* Must be a multiple of chunk_size */
-	chunk = mddev->chunk_sectors;
-	if (chunk) {
-		sector_t temp = min;
-
-		err = -EINVAL;
-		if (sector_div(temp, chunk))
-			goto out_unlock;
-	}
-	mddev->resync_min = min;
+	/* Round down to multiple of 4K for safety */
+	mddev->resync_min = round_down(min, 8);
 	err = 0;
 
 out_unlock: