Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755514Ab2E1DwY (ORCPT ); Sun, 27 May 2012 23:52:24 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51918 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753515Ab2E1D3M (ORCPT ); Sun, 27 May 2012 23:29:12 -0400 Message-Id: <20120528031204.124440304@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 28 May 2012 04:12:11 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Bernd Schubert , Jens Axboe Subject: [ 009/117] bio allocation failure due to bio_get_nr_vecs() In-Reply-To: <20120528031202.829379252@decadent.org.uk> X-SA-Exim-Connect-IP: 192.168.4.185 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1676 Lines: 54 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bernd Schubert commit f908ee9463b09ddd05e1c1a0111132212dc05fac upstream. The number of bio_get_nr_vecs() is passed down via bio_alloc() to bvec_alloc_bs(), which fails the bio allocation if nr_iovecs > BIO_MAX_PAGES. For the underlying caller this causes an unexpected bio allocation failure. Limiting to queue_max_segments() is not sufficient, as max_segments also might be very large. bvec_alloc_bs(gfp_mask, nr_iovecs, ) => NULL when nr_iovecs > BIO_MAX_PAGES bio_alloc_bioset(gfp_mask, nr_iovecs, ...) bio_alloc(GFP_NOIO, nvecs) xfs_alloc_ioend_bio() Signed-off-by: Bernd Schubert Signed-off-by: Jens Axboe Signed-off-by: Ben Hutchings --- fs/bio.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/bio.c b/fs/bio.c index e453924..84da885 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -505,9 +505,14 @@ EXPORT_SYMBOL(bio_clone); int bio_get_nr_vecs(struct block_device *bdev) { struct request_queue *q = bdev_get_queue(bdev); - return min_t(unsigned, + int nr_pages; + + nr_pages = min_t(unsigned, queue_max_segments(q), queue_max_sectors(q) / (PAGE_SIZE >> 9) + 1); + + return min_t(unsigned, nr_pages, BIO_MAX_PAGES); + } EXPORT_SYMBOL(bio_get_nr_vecs); -- 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/