[PATCH 1/1] unblock the creation of an external metadata RAID ifnative one exists

From aa169142c6dde0a7c1dc1b91dec0973474661036 Mon Sep 17 00:00:00 2001
From: Marcin Labun
Date: Tue, 25 Jan 2011 15:57:20 +0100
Subject: [PATCH 1/1] md: unblock the creation of an external metadata RAID if native one exists

Native metadata reserves a parent disk device for exclusive use by setting
AllReserved in rdev->flags. Now if a member device has AllReserved flag set
on its block device then creation of any external metadata array/container on
is unreasonably blocked.
Solution:
When creating a new external RAID device we must check that the new
device is not using a partition of a disk, when there is another array
using another partition of the same disk calming exclusive usage for the
disk. Exclusive usage is enforced by setting AllReserved in rdev->flags.

Signed-off-by: Marcin Labun
---
drivers/md/md.c | 19 +++++++++++++++++--
1 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 175c424..1bb309f 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2603,15 +2603,30 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
mddev_unlock(my_mddev);
for_each_mddev(mddev, tmp) {
mdk_rdev_t *rdev2;
-
+
mddev_lock(mddev);
+
list_for_each_entry(rdev2, &mddev->disks, same_set)
- if (test_bit(AllReserved, &rdev2->flags) ||
+ if ((test_bit(AllReserved, &rdev2->flags) &&
+ rdev->bdev->bd_contains == rdev2->bdev->bd_contains) ||
(rdev->bdev == rdev2->bdev &&
rdev != rdev2 &&
overlaps(rdev->data_offset, rdev->sectors,
rdev2->data_offset,
rdev2->sectors))) {
+ char b[BDEVNAME_SIZE];
+
+ dprintk(KERN_INFO "rdev: %p %s\n", rdev, bdevname(rdev->bdev,b));
+ dprintk(KERN_INFO "rdev tested: %p %s\n", rdev2, bdevname(rdev2->bdev,b));
+ dprintk(KERN_INFO "my_mddev: %p tested: %p if: %d, %d, %d, %d, %d \n",
+ my_mddev,
+ mddev,
+ test_bit(AllReserved, &rdev2->flags),
+ rdev->bdev->bd_contains == rdev2->bdev->bd_contains,
+ rdev->bdev == rdev2->bdev,
+ rdev != rdev2,
+ overlaps(rdev->data_offset, rdev->sectors,
+ rdev2->data_offset, rdev2->sectors));
overlap = 1;
break;
}
--
1.6.4.2

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