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From: Martin Schwidefsky <schwidefsky@de.ibm.com>
To: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org
Cc: Stefan Weinhuber <wein@de.ibm.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: [patch 05/10] dasd: fix reference counting in display method for proc/dasd/devices
Date: Wed, 05 Mar 2008 12:54:37 +0100	[thread overview]
Message-ID: <20080305115714.023087298@de.ibm.com> (raw)
In-Reply-To: <20080305115432.691030908@de.ibm.com>

[-- Attachment #1: 005-dasd-refcount.diff --]
[-- Type: text/plain, Size: 1137 bytes --]

From: Stefan Weinhuber <wein@de.ibm.com>

Using the /proc/dasd/devices interface leaves the reference counter
of alias devices in an inconsistent state. A process that tries to set
such a device offline afterwards will hang.
The dasd_devices_show function returns immediately for alias devices
and this code path was missing a dasd_put_device call.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 drivers/s390/block/dasd_proc.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Index: quilt-2.6/drivers/s390/block/dasd_proc.c
===================================================================
--- quilt-2.6.orig/drivers/s390/block/dasd_proc.c
+++ quilt-2.6/drivers/s390/block/dasd_proc.c
@@ -62,8 +62,10 @@ dasd_devices_show(struct seq_file *m, vo
 		return 0;
 	if (device->block)
 		block = device->block;
-	else
+	else {
+		dasd_put_device(device);
 		return 0;
+	}
 	/* Print device number. */
 	seq_printf(m, "%s", device->cdev->dev.bus_id);
 	/* Print discipline string. */

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.


  parent reply	other threads:[~2008-03-05 11:59 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-05 11:54 [patch 00/10] s390 bux fixes for 2.6.25-rc4 Martin Schwidefsky
2008-03-05 11:54 ` [patch 01/10] Update default configuration Martin Schwidefsky
2008-03-05 11:54 ` [patch 02/10] idle: Fix machine check handling in idle loop Martin Schwidefsky
2008-03-05 11:54 ` [patch 03/10] Get rid of memcpy gcc warning workaround Martin Schwidefsky
2008-03-05 11:54 ` [patch 04/10] dasd: let dasd erp matching recognize alias recovery Martin Schwidefsky
2008-03-05 11:54 ` Martin Schwidefsky [this message]
2008-03-05 11:54 ` [patch 06/10] sclp_vt220: speed up console output for interactive work Martin Schwidefsky
2008-03-05 11:54 ` [patch 07/10] zcrypt: fix ap_device_list handling Martin Schwidefsky
2008-03-05 11:54 ` [patch 08/10] Fix IPL from NSS Martin Schwidefsky
2008-03-05 11:54 ` [patch 09/10] Load disabled wait psw if reipl fails Martin Schwidefsky
2008-03-05 11:54 ` [patch 10/10] incorrect reipl nss name Martin Schwidefsky

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