Re: BUG: using rootfstype=ext4 causes oops

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Thursday 16 April 2009 19:05:56 Andrew Price wrote:
> On Thu, Apr 16, 2009 at 06:02:21PM +0200, Bartlomiej Zolnierkiewicz wrote:
> > Freeing non-slab objects is bad.
> > 
> > Andrew, does this patch help?
> 
> Yes, that seems to fix it. I tested it with gfs2 and ext4 the usual way
> and I couldn't reproduce the panic.
> 
> Thanks Bartlomiej.

Great, I'll queue the following patch for the next round of IDE fixes.

From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Subject: [PATCH] ide: fix barriers support

Freeing non-slab objects is bad and results in an oops.  Fix it.

Reported-and-tested-by: Andrew Price <andy@andrewprice.me.uk>
Cc: Theodore Tso <tytso@mit.edu>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
---
 drivers/ide/ide-io.c |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

Index: b/drivers/ide/ide-io.c
===================================================================
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -102,11 +102,14 @@ void ide_complete_cmd(ide_drive_t *drive
 			drive->dev_flags |= IDE_DFLAG_PARKED;
 	}
 
-	if (rq && rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
-		memcpy(rq->special, cmd, sizeof(*cmd));
+	if (rq && rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
+		struct ide_cmd *orig_cmd = rq->special;
 
-	if (cmd->tf_flags & IDE_TFLAG_DYN)
-		kfree(cmd);
+		if (cmd->tf_flags & IDE_TFLAG_DYN)
+			kfree(orig_cmd);
+		else
+			memcpy(orig_cmd, cmd, sizeof(*cmd));
+	}
 }
 
 /* obsolete, blk_rq_bytes() should be used instead */