From: Dan Williams <dan.j.williams@intel.com>
Date: Wed, 26 Nov 2008 22:39:51 +0000 (-0700)
Subject: imsm: fix metadata reservation
X-Git-Tag: mdadm-3.0-devel3~64
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dda5855f96baa1b7e15e6ee8bb6d985e269257e5;p=thirdparty%2Fmdadm.git

imsm: fix metadata reservation

1/ When truncating the space reserved for the metadata round down to an
   even numbered sector count to avoid an off-by-one error when
   sysfs_add_disk rounds up.
2/ Set the current metadata parameter block size
   as a floor.

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

diff --git a/super-intel.c b/super-intel.c
index 5d8944ce..99419ffd 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -489,6 +489,13 @@ static struct extent *get_extents(struct intel_super *super, struct dl *dl)
 
 		remainder = __le32_to_cpu(dl->disk.total_blocks) - 
 			    (last->start + last->size);
+		/* round down to 1k block to satisfy precision of the kernel
+		 * 'size' interface
+		 */
+		remainder &= ~1UL;
+		/* make sure remainder is still sane */
+		if (remainder < ROUND_UP(super->len, 512) >> 9)
+			remainder = ROUND_UP(super->len, 512) >> 9;
 		if (reservation > remainder)
 			reservation = remainder;
 	}