2013-10-31 19:38:31

by Chris Mason

Subject: [PATCH] Btrfs: update bi_remaining to relfect our bio endio chaining

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 <[email protected]>

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);

2013-10-31 19:57:21

by Kent Overstreet

Subject: Re: [PATCH] Btrfs: update bi_remaining to relfect our bio endio chaining

On Thu, Oct 31, 2013 at 03:38:20PM -0400, Chris Mason wrote:
> 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 <[email protected]>

Beat me to it :P

Tested-by: Kent Overstreet <[email protected]>