From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Olien Subject: Re: dev kernels(bio change), evms_activate still produces oops Date: Wed, 9 Feb 2005 15:10:44 -0800 Message-ID: <20050209231044.GA959@osdl.org> References: <87sm48dnh2.87r7jsdnh2@87pszcdnh2.message.id> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87sm48dnh2.87r7jsdnh2@87pszcdnh2.message.id> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: syrius.ml@no-log.org Cc: evms-devel@lists.sourceforge.net, dm-devel@redhat.com, agk@redhat.com List-Id: dm-devel.ids Sorry for being so slow. Here's a patch that I believe will fix this oops. Please give this a try and let me know. The problem is that when I coded up the new bio_clone() code, I made the bad assumption that the bio passed in would have been allocated from a bio_set. In the case of raid5 and raid6, this isn't the case. So, when raid5 passes one of its bio's into the dm code, and dm tries to bio_clone() it, bio_clone() dereferences a NULL pointer. As a quick fix, this patch changes bio_clone() to just use the global bio_set to allocate the new bio. Problem is, this potentially sets up another bio exhaustion case. I'm thinking there should maybe be a bio_clone_bioset() that accepts a bio_set pointer as an argument. That way, dm could for example pass in it's own bio_set to allocate from. But for now, here's the quick patch. Please give it a try and give me the results. diff -ur linux-2.6.11-rc3-bk4-udm1/fs/bio.c linux-2.6.11-rc3-bk4-udm1-patch/fs/bio.c --- linux-2.6.11-rc3-bk4-udm1/fs/bio.c 2005-02-08 15:36:16.000000000 -0800 +++ linux-2.6.11-rc3-bk4-udm1-patch/fs/bio.c 2005-02-09 14:56:39.000000000 -0800 @@ -258,7 +258,7 @@ */ struct bio *bio_clone(struct bio *bio, int gfp_mask) { - struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, bio->bi_set); + struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set); if (b) __bio_clone(b, bio); -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel