From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta8.messagelabs.com (mail6.bemta8.messagelabs.com [216.82.243.55]) by kanga.kvack.org (Postfix) with ESMTP id DC6F7900137 for ; Tue, 13 Sep 2011 13:37:49 -0400 (EDT) MIME-Version: 1.0 Message-ID: <2ca31b06-eef9-49e4-beba-4959471b45d2@default> Date: Tue, 13 Sep 2011 10:37:23 -0700 (PDT) From: Dan Magenheimer Subject: [REVERT for 3.1-rc7] staging: zcache: revert "fix crash on high memory swap" Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Greg KH Cc: Francis Moreau , gregkh@suse.de, Seth Jennings , devel@driverdev.osuosl.org, linux-mm@kvack.org, Nitin Gupta , linux-kernel@vger.kernel.org Hi Greg -- Please revert the following commit, hopefully before 3.1 is released. Although it fixes a crash in 32-bit systems with high memory, the fix apparently *causes* crashes on 64-bit systems. Not sure why my testing didn't catch it before but it has now been observed in the wild in 3.1-rc4 and I can reproduce it now fairly easily. 3.1-rc3 works fine, 3.1-rc4 fails, and 3.1-rc3 plus only this commit fails. Let's revert it before 3.1 and Seth and Nitin and I will sort out a better fix later. Reported-by: Francis Moreau Reproduced-by: Dan Magenheimer Thanks, Dan commit c5f5c4db393837ebb2ae47bf061d70e498f48f8c Author: Seth Jennings Date: Wed Aug 10 12:56:49 2011 -0500 staging: zcache: fix crash on high memory swap =20 zcache_put_page() was modified to pass page_address(page) instead of th= e actual page structure. In combination with the function signature chang= es to tmem_put() and zcache_pampd_create(), zcache_pampd_create() tries to (re)derive the page structure from the virtual address. However, if th= e original page is a high memory page (or any unmapped page), this virt_to_page() fails because the page_address() in zcache_put_page() returned NULL. =20 This patch changes zcache_put_page() and zcache_get_page() to pass the page structure instead of the page's virtual address, which may or may not exist. =20 Signed-off-by: Seth Jennings Acked-by: Dan Magenheimer Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/= zcache-main.c index 855a5bb..a3f5162 100644 --- a/drivers/staging/zcache/zcache-main.c +++ b/drivers/staging/zcache/zcache-main.c @@ -1158,7 +1158,7 @@ static void *zcache_pampd_create(char *data, size_t s= ize, bool raw, int eph, =09size_t clen; =09int ret; =09unsigned long count; -=09struct page *page =3D virt_to_page(data); +=09struct page *page =3D (struct page *)(data); =09struct zcache_client *cli =3D pool->client; =09uint16_t client_id =3D get_client_id_from_client(cli); =09unsigned long zv_mean_zsize; @@ -1227,7 +1227,7 @@ static int zcache_pampd_get_data(char *data, size_t *= bufsize, bool raw, =09int ret =3D 0; =20 =09BUG_ON(is_ephemeral(pool)); -=09zv_decompress(virt_to_page(data), pampd); +=09zv_decompress((struct page *)(data), pampd); =09return ret; } =20 @@ -1539,7 +1539,7 @@ static int zcache_put_page(int cli_id, int pool_id, s= truct tmem_oid *oidp, =09=09goto out; =09if (!zcache_freeze && zcache_do_preload(pool) =3D=3D 0) { =09=09/* preload does preempt_disable on success */ -=09=09ret =3D tmem_put(pool, oidp, index, page_address(page), +=09=09ret =3D tmem_put(pool, oidp, index, (char *)(page), =09=09=09=09PAGE_SIZE, 0, is_ephemeral(pool)); =09=09if (ret < 0) { =09=09=09if (is_ephemeral(pool)) @@ -1572,7 +1572,7 @@ static int zcache_get_page(int cli_id, int pool_id, s= truct tmem_oid *oidp, =09pool =3D zcache_get_pool_by_id(cli_id, pool_id); =09if (likely(pool !=3D NULL)) { =09=09if (atomic_read(&pool->obj_count) > 0) -=09=09=09ret =3D tmem_get(pool, oidp, index, page_address(page), +=09=09=09ret =3D tmem_get(pool, oidp, index, (char *)(page), =09=09=09=09=09&size, 0, is_ephemeral(pool)); =09=09zcache_put_pool(pool); =09} -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org