From: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Date: Sun, 21 Mar 2010 21:52:23 +0000 (+0100)
Subject: libata: don't flush dcache on slab pages
X-Git-Tag: v2.6.34.1~190
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=968ada73731c432d54d0d273bc2a82aceb06deea;p=thirdparty%2Fkernel%2Fstable.git

libata: don't flush dcache on slab pages

commit 3842e835490cdf17013b30a788f6311bdcfd0571 upstream.

page_mapping() check this via VM_BUG_ON(PageSlab(page)) so we bug here
with the according debuging turned on.

Future TODO: replace this with a flush_dcache_page_for_pio() API

Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index e3877b6843c9a..472364889a719 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -894,7 +894,7 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
 				       do_write);
 	}
 
-	if (!do_write)
+	if (!do_write && !PageSlab(page))
 		flush_dcache_page(page);
 
 	qc->curbytes += qc->sect_size;