Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758775AbYJGAt7 (ORCPT ); Mon, 6 Oct 2008 20:49:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757459AbYJGAnx (ORCPT ); Mon, 6 Oct 2008 20:43:53 -0400 Received: from ns2.suse.de ([195.135.220.15]:60515 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755868AbYJGAnw (ORCPT ); Mon, 6 Oct 2008 20:43:52 -0400 Date: Mon, 6 Oct 2008 17:38:33 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, James.Bottomley@HansenPartnership.com, jens.axboe@oracle.com, FUJITA Tomonori Subject: [patch 26/71] sg: disable interrupts inside sg_copy_buffer Message-ID: <20081007003833.GA3055@suse.de> References: <20081007002606.723632097@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="sg-disable-interrupts-inside-sg_copy_buffer.patch" In-Reply-To: <20081007003634.GA3055@suse.de> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1695 Lines: 57 2.6.26-stable review patch. If anyone has any objections, please let us know. ------------------ From: FUJITA Tomonori This is the backport of the upstream commit 50bed2e2862a8f3a4f7d683d0d27292e71ef18b9 The callers of sg_copy_buffer must disable interrupts before calling it (since it uses kmap_atomic). Some callers use it on interrupt-disabled code but some need to take the trouble to disable interrupts just for this. No wonder they forget about it and we hit a bug like: http://bugzilla.kernel.org/show_bug.cgi?id=11529 James said that it might be better to disable interrupts inside the function rather than risk the callers getting it wrong. Signed-off-by: FUJITA Tomonori Signed-off-by: Jens Axboe Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman --- lib/scatterlist.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -312,8 +312,9 @@ static size_t sg_copy_buffer(struct scat struct scatterlist *sg; size_t buf_off = 0; int i; + unsigned long flags; - WARN_ON(!irqs_disabled()); + local_irq_save(flags); for_each_sg(sgl, sg, nents, i) { struct page *page; @@ -358,6 +359,8 @@ static size_t sg_copy_buffer(struct scat break; } + local_irq_restore(flags); + return buf_off; } -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/