Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754211AbaAGVXN (ORCPT ); Tue, 7 Jan 2014 16:23:13 -0500 Received: from mail-pa0-f42.google.com ([209.85.220.42]:65149 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753165AbaAGVXF (ORCPT ); Tue, 7 Jan 2014 16:23:05 -0500 MIME-Version: 1.0 In-Reply-To: <1389126617.23310.19.camel@ret.masoncoding.com> References: <20140102053101.GA29352@localhost> <20140106221036.GE9037@kmo> <20140107055318.GA19016@localhost> <1389126617.23310.19.camel@ret.masoncoding.com> Date: Tue, 7 Jan 2014 13:23:04 -0800 Message-ID: Subject: Re: [block:for-3.14/core] kernel BUG at fs/bio.c:1748 From: Muthu Kumar To: Chris Mason Cc: "kmo@daterainc.com" , "linux-btrfs@vger.kernel.org" , "fengguang.wu@intel.com" , "linux-kernel@vger.kernel.org" , "lkp@linux.intel.com" , "axboe@kernel.dk" , "linux-fsdevel@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Chris, This is based off of Jens block tree, for-3.14/core branch... Regards, Muthu On Tue, Jan 7, 2014 at 12:29 PM, Chris Mason wrote: > On Tue, 2014-01-07 at 12:15 -0800, Muthu Kumar wrote: >> Thanks Fengguang. Final patch with added comment. BTW, fengguang >> mentioned that git-am has trouble with the inline patch and "quilt >> import" worked fine for him... >> >> ------------ >> In btrfs_end_bio(), we increment bi_remaining if is_orig_bio. If not, >> we restore the orig_bio but failed to increment bi_remaining for >> orig_bio, which triggers a BUG_ON later when bio_endio is called. Fix >> is to increment bi_remaining when we restore the orig bio as well. >> > > Hi everyone, > > Which git tree is this against? Just Jens or some extra code too? > > I'll run some tests here. My original patch is below (it's slightly > different from Muthu's). > > Btrfs is sometimes calling bio_endio twice on the same bio while > we chain things. This makes sure we don't trip over new assertions in > fs/bio.c > > Signed-off-by: Chris Mason > > diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c > index 7fcac70..5b30360 100644 > --- a/fs/btrfs/check-integrity.c > +++ b/fs/btrfs/check-integrity.c > @@ -2289,6 +2289,10 @@ static void btrfsic_bio_end_io(struct bio *bp, int bio_error_status) > block = next_block; > } while (NULL != block); > > + /* > + * since we're not using bio_endio here, we don't need to worry about > + * the remaining count > + */ > bp->bi_end_io(bp, bio_error_status); > } > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index 62176ad..786ddac 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -1684,7 +1684,7 @@ static void end_workqueue_fn(struct btrfs_work *work) > bio->bi_private = end_io_wq->private; > bio->bi_end_io = end_io_wq->end_io; > kfree(end_io_wq); > - bio_endio(bio, error); > + bio_endio_nodec(bio, error); > } > > static int cleaner_kthread(void *arg) > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index ef48947..a31448f 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -5284,9 +5284,17 @@ static void btrfs_end_bio(struct bio *bio, int err) > } > } > > - if (bio == bbio->orig_bio) > + if (bio == bbio->orig_bio) { > is_orig_bio = 1; > > + /* > + * eventually we will call the bi_endio for the original bio, > + * make sure that we've properly bumped bi_remaining to reflect > + * our chain of endios here > + */ > + atomic_inc(&bio->bi_remaining); > + } > + > if (atomic_dec_and_test(&bbio->stripes_pending)) { > if (!is_orig_bio) { > bio_put(bio); > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- 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/