From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q4BEVa8v035985 for ; Fri, 11 May 2012 09:31:37 -0500 Received: from mailgw1.uni-kl.de (mailgw1.uni-kl.de [131.246.120.220]) by cuda.sgi.com with ESMTP id RCAfd8Mwp7IriYVy (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Fri, 11 May 2012 07:31:35 -0700 (PDT) Received: from itwm2.itwm.fhg.de (itwm2.itwm.fhg.de [131.246.191.3]) by mailgw1.uni-kl.de (8.14.3/8.14.3/Debian-5+lenny1) with ESMTP id q4BEVWAr028400 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NOT) for ; Fri, 11 May 2012 16:31:32 +0200 Message-ID: <4FAD22BD.7010007@itwm.fraunhofer.de> Date: Fri, 11 May 2012 16:31:25 +0200 From: Bernd Schubert MIME-Version: 1.0 Subject: Re: [PATCH] bio allocation failure due to bio_get_nr_vecs() References: <4FABF01E.7080303@itwm.fraunhofer.de> <4FAD18D4.3090102@itwm.fraunhofer.de> In-Reply-To: Content-Type: multipart/mixed; boundary="------------080007060100060203010907" List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Jeff Moyer Cc: Jens Axboe , sandeen@sandeen.net, linux-xfs@oss.sgi.com, Tejun Heo , "linux-fsdevel@vger.kernel.org" , Kent Overstreet This is a multi-part message in MIME format. --------------080007060100060203010907 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit On 05/11/2012 04:06 PM, Jeff Moyer wrote: > Bernd Schubert writes: > >> 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; > > Looks like a corrupt patch. What do you actually mean? Issue by thunderbird? I just saved the mail in my sent folder and it looks? Just to be sure, patch attached. Thanks, Bernd --------------080007060100060203010907 Content-Type: text/x-patch; name="fix-bio-nrvec.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="fix-bio-nrvec.patch" bio: bio_get_nr_vecs() must not return more than BIO_MAX_PAGES From: Bernd Schubert 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 sufficiet, 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 --- 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); --------------080007060100060203010907 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs --------------080007060100060203010907--