This is a note to let you know that I've just added the patch titled
md/raid10: fix "enough" function for detecting if array is failed.
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
md-raid10-fix-enough-function-for-detecting-if-array-is-failed.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4e19de3be14c9390e63271effb5b95ab50f298f4 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@xxxxxxx>
Date: Thu, 27 Sep 2012 12:35:21 +1000
Subject: md/raid10: fix "enough" function for detecting if array is failed.
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From: NeilBrown <neilb@xxxxxxx>
commit 80b4812407c6b1f66a4f2430e69747a13f010839 upstream.
The 'enough' function is written to work with 'near' arrays only
in that is implicitly assumes that the offset from one 'group' of
devices to the next is the same as the number of copies.
In reality it is the number of 'near' copies.
So change it to make this number explicit.
This bug makes it possible to run arrays without enough drives
present, which is dangerous.
It is appropriate for an -stable kernel, but will almost certainly
need to be modified for some of them.
Reported-by: Jakub Husák <jakub@xxxxxxxxxxx>
Signed-off-by: NeilBrown <neilb@xxxxxxx>
[bwh: Backported to 3.2: s/geo->/conf->/]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Cc: Rui Xiang <rui.xiang@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/raid10.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1419,14 +1419,16 @@ static int enough(struct r10conf *conf,
do {
int n = conf->copies;
int cnt = 0;
+ int this = first;
while (n--) {
- if (conf->mirrors[first].rdev &&
- first != ignore)
+ if (conf->mirrors[this].rdev &&
+ this != ignore)
cnt++;
- first = (first+1) % conf->raid_disks;
+ this = (this+1) % conf->raid_disks;
}
if (cnt == 0)
return 0;
+ first = (first + conf->near_copies) % conf->raid_disks;
} while (first != 0);
return 1;
}
Patches currently in stable-queue which might be from neilb@xxxxxxx are
queue-3.4/md-avoid-possible-spinning-md-thread-at-shutdown.patch
queue-3.4/md-raid10-fix-enough-function-for-detecting-if-array-is-failed.patch
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