From: Pete Zaitcev <zaitcev@redhat.com>
To: neilb@cse.unsw.edu.au
Cc: linux-raid@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
Pete Zaitcev <zaitcev@redhat.com>
Subject: Bug in RAID1 in 2.4
Date: Sat, 20 Dec 2003 03:25:47 -0500 [thread overview]
Message-ID: <20031220082547.GB18118@devserv.devel.redhat.com> (raw)
In drivers/md/raid1.c, raid1_sync_request contains the following:
block_nr = sector_nr;
bsize = 512;
while (!(block_nr & 1) && bsize < PAGE_SIZE
&& (block_nr+2)*(bsize>>9) < (mddev->sb->size *2)) {
block_nr >>= 1;
bsize <<= 1;
}
Suppose that a mirror is 4K in size. The code above produces
reads (and writes) of the following offsets and sizes:
0K[2K], 2K[1K], 3K[0.5K], 3.5K[0.5K]
The above is correct, but it makes the RAID1 completely unuseable
on s390, because I/O with sizes less than 4K is not supported.
I would like the attached patch applied to correct the issue.
-- Pete
--- linux-2.4.23/drivers/md/raid1.c 2003-06-13 07:51:34.000000000 -0700
+++ linux-2.4.23-nip/drivers/md/raid1.c 2003-12-19 23:57:57.000000000 -0800
@@ -1436,7 +1436,7 @@
block_nr = sector_nr;
bsize = 512;
while (!(block_nr & 1) && bsize < PAGE_SIZE
- && (block_nr+2)*(bsize>>9) < (mddev->sb->size *2)) {
+ && (block_nr+2)*(bsize>>9) <= (mddev->sb->size *2)) {
block_nr >>= 1;
bsize <<= 1;
}
next reply other threads:[~2003-12-20 8:25 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-12-20 8:25 Pete Zaitcev [this message]
2003-12-21 9:44 ` Bug in RAID1 in 2.4 Neil Brown
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