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From: Willy Tarreau <w@1wt.eu>
To: linux-kernel@vger.kernel.org, stable@kernel.org,
	stable-review@kernel.org
Cc: NeilBrown <neilb@suse.de>, Greg Kroah-Hartman <gregkh@suse.de>,
	Willy Tarreau <w@1wt.eu>
Subject: [PATCH 11/23] md: fix bug with re-adding of partially recovered device.
Date: Mon, 07 Feb 2011 00:23:03 +0100	[thread overview]
Message-ID: <20110206232252.997683635@pcw.home.local> (raw)
In-Reply-To: <4beed4da27f06efb2c13d6ed48850634@local>

2.6.27.58-stable review patch.  If anyone has any objections, please let us know.

------------------

From: NeilBrown <neilb@suse.de>

commit 1a855a0606653d2d82506281e2c686bacb4b2f45 upstream.

With v0.90 metadata, a hot-spare does not become a full member of the
array until recovery is complete.  So if we re-add such a device to
the array, we know that all of it is as up-to-date as the event count
would suggest, and so it a bitmap-based recovery is possible.

However with v1.x metadata, the hot-spare immediately becomes a full
member of the array, but it record how much of the device has been
recovered.  If the array is stopped and re-assembled recovery starts
from this point.

When such a device is hot-added to an array we currently lose the 'how
much is recovered' information and incorrectly included it as a full
in-sync member (after bitmap-based fixup).
This is wrong and unsafe and could corrupt data.

So be more careful about setting saved_raid_disk - which is what
guides the re-adding of devices back into an array.
The new code matches the code in slot_store which does a similar
thing, which is encouraging.

This is suitable for any -stable kernel.

Reported-by: "Dailey, Nate" <Nate.Dailey@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>

---
 drivers/md/md.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Index: longterm-2.6.27/drivers/md/md.c
===================================================================
--- longterm-2.6.27.orig/drivers/md/md.c	2011-01-29 11:19:14.697066081 +0100
+++ longterm-2.6.27/drivers/md/md.c	2011-01-29 11:27:14.692063986 +0100
@@ -4300,7 +4300,7 @@
 				PTR_ERR(rdev));
 			return PTR_ERR(rdev);
 		}
-		/* set save_raid_disk if appropriate */
+		/* set saved_raid_disk if appropriate */
 		if (!mddev->persistent) {
 			if (info->state & (1<<MD_DISK_SYNC)  &&
 			    info->raid_disk < mddev->raid_disks)
@@ -4310,7 +4310,10 @@
 		} else
 			super_types[mddev->major_version].
 				validate_super(mddev, rdev);
-		rdev->saved_raid_disk = rdev->raid_disk;
+		if (test_bit(In_sync, &rdev->flags))
+			rdev->saved_raid_disk = rdev->raid_disk;
+		else
+			rdev->saved_raid_disk = -1;
 
 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))



  parent reply	other threads:[~2011-02-06 23:46 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20110206232252.509080428@pcw.home.local>
2011-02-06 23:22 ` [PATCH 00/23] 2.6.27.58-longterm review Willy Tarreau
2011-02-06 23:22   ` [PATCH 01/23] ALSA: hda: Use model=lg quirk for LG P1 Express to enable playback and capture Willy Tarreau
2011-02-06 23:22   ` [PATCH 02/23] ALSA: hda: Use LPIB for Dell Latitude 131L Willy Tarreau
2011-02-06 23:22   ` [PATCH 03/23] ALSA: hda: Use LPIB quirk for Dell Inspiron m101z/1120 Willy Tarreau
2011-02-06 23:22   ` [PATCH 04/23] USB: usb-storage: unusual_devs entry for the Samsung YP-CP3 Willy Tarreau
2011-02-06 23:22   ` [PATCH 05/23] USB: misc: uss720.c: add another vendor/product ID Willy Tarreau
2011-02-06 23:22   ` [PATCH 06/23] HID: hidraw: fix window in hidraw_release Willy Tarreau
2011-02-06 23:22   ` [PATCH 07/23] hwmon: (adm1026) Allow 1 as a valid divider value Willy Tarreau
2011-02-06 23:23   ` [PATCH 08/23] hwmon: (adm1026) Fix setting fan_div Willy Tarreau
2011-02-06 23:23   ` [PATCH 09/23] IB/uverbs: Handle large number of entries in poll CQ Willy Tarreau
2011-02-06 23:23   ` [PATCH 10/23] mv_xor: fix race in tasklet function Willy Tarreau
2011-02-06 23:23   ` Willy Tarreau [this message]
2011-02-06 23:23   ` [PATCH 12/23] NFS: Fix fcntl F_GETLK not reporting some conflicts Willy Tarreau
2011-02-06 23:23   ` [PATCH 13/23] nfsd: Fix possible BUG_ON firing in set_change_info Willy Tarreau
2011-02-06 23:23   ` [PATCH 14/23] PM / Hibernate: Fix PM_POST_* notification with user-space suspend Willy Tarreau
2011-02-06 23:23   ` [PATCH 15/23] posix-cpu-timers: workaround to suppress the problems with mt exec Willy Tarreau
2011-02-06 23:23   ` [PATCH 16/23] sctp: Fix a race between ICMP protocol unreachable and connect() Willy Tarreau
2011-02-06 23:23   ` [PATCH 17/23] sound: Prevent buffer overflow in OSS load_mixer_volumes Willy Tarreau
2011-02-06 23:23   ` [PATCH 18/23] sunrpc: prevent use-after-free on clearing XPT_BUSY Willy Tarreau
2011-02-06 23:23   ` [PATCH 19/23] x86, gcc-4.6: Use gcc -m options when building vdso Willy Tarreau
2011-02-06 23:23   ` [PATCH 20/23] tracing: Fix panic when lseek() called on "trace" opened for writing Willy Tarreau
2011-02-14 23:14     ` [Stable-review] " Ben Hutchings
2011-02-15  1:33       ` Steven Rostedt
2011-02-15  1:38         ` Ben Hutchings
2011-02-15  2:01           ` Steven Rostedt
2011-02-15  5:39       ` Willy Tarreau
2011-02-06 23:23   ` [PATCH 21/23] hvc_console: Fix race between hvc_close and hvc_remove Willy Tarreau
2011-02-07 21:16     ` Anton Blanchard
2011-02-07 22:11       ` Willy Tarreau
2011-02-06 23:23   ` [PATCH 22/23] hvc_console: Fix race between hvc_close and hvc_remove, again Willy Tarreau
2011-02-06 23:23   ` [PATCH 23/23] install_special_mapping skips security_file_mmap check Willy Tarreau

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