lkml.org 
[lkml]   [2013]   [Nov]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRe: Boot failure on Arndale with next-20131105
Date
Quoting Olof Johansson (2013-11-05 15:38:33)
> On Tue, Nov 5, 2013 at 12:33 PM, Chris Mason <chris.mason@fusionio.com> wrote:
> > Quoting Olof Johansson (2013-11-05 15:23:51)
> >> On Tue, Nov 5, 2013 at 11:33 AM, Jens Axboe <axboe@kernel.dk> wrote:
> >
> > [ horrible crashes fixed by removing my patch ]
> >
> >> > Very weird! What file system is being used?
> >>
> >> Most of my failures have happened on regular MMC cards with ext4
> >> filesystems on them.
> >>
> >> Note that the panic happens during device probe / partition table
> >> scanning, not after mounting the filesystem.
> >>
> >> Giving your patch a go now across the board. I'm very concerned about
> >> the reports of bisectability, build failures and heaps of warnings
> >> though. Did the 0-day builder pick up any of those? :-/
> >>
> >
> > Hmmm, is bcache in your config?
>
> Doesn't look that way -- no ARM defconfigs enable it (it's what I
> build and boot), and the option defaults to off and nothing selects
> it.

Ok, I think I see it. My guess is that you're hitting bounce buffers.
__blk_queue_bounce is the only caller of the bio splitting code I can
see that you might be hitting.

My first patch exposed a lurking bug in bio_clone_biovec. Basically
bio->bi_vcnt is being doubled instead of initialized.

This patch is only compile tested, but I think it'll fix it.

diff --git a/fs/bio.c b/fs/bio.c
index be93de1..3595456 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -612,6 +612,7 @@ int bio_clone_biovec(struct bio *bio, gfp_t gfp_mask)
unsigned nr_iovecs = 0;
struct bio_vec bv, *bvl = NULL;
struct bvec_iter iter;
+ int i;

BUG_ON(!bio->bi_pool);
BUG_ON(BIO_POOL_IDX(bio) != BIO_POOL_NONE);
@@ -628,8 +629,9 @@ int bio_clone_biovec(struct bio *bio, gfp_t gfp_mask)
bvl = bio->bi_inline_vecs;
}

+ i = 0;
bio_for_each_segment(bv, bio, iter)
- bvl[bio->bi_vcnt++] = bv;
+ bvl[i++] = bv;

bio->bi_io_vec = bvl;
bio->bi_iter.bi_idx = 0;

\
 
 \ /
  Last update: 2013-11-05 22:21    [W:0.072 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site