lkml.org 
[lkml]   [2012]   [Sep]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] block: makes bio_split support bio without data

Hi Jens,
this patch has been sitting in my -next tree for a little while and I was
hoping for it to go in for the next merge window.
It simply allows bio_split() to be used on bios without a payload, such as
'discard'.
Are you happy with it going in though my 'md' tree, or would you rather take
it though your 'block' tree?

Thanks,
NeilBrown


From: Shaohua Li <shli@fusionio.com>
Date: Thu, 20 Sep 2012 09:36:03 +1000
Subject: [PATCH] block: makes bio_split support bio without data

discard bio hasn't data attached. We hit a BUG_ON with such bio. This makes
bio_split works for such bio.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/fs/bio.c b/fs/bio.c
index 71072ab..dbb7a6c 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -1501,7 +1501,7 @@ struct bio_pair *bio_split(struct bio *bi, int first_sectors)
trace_block_split(bdev_get_queue(bi->bi_bdev), bi,
bi->bi_sector + first_sectors);

- BUG_ON(bi->bi_vcnt != 1);
+ BUG_ON(bi->bi_vcnt != 1 && bi->bi_vcnt != 0);
BUG_ON(bi->bi_idx != 0);
atomic_set(&bp->cnt, 3);
bp->error = 0;
@@ -1511,17 +1511,19 @@ struct bio_pair *bio_split(struct bio *bi, int first_sectors)
bp->bio2.bi_size -= first_sectors << 9;
bp->bio1.bi_size = first_sectors << 9;

- bp->bv1 = bi->bi_io_vec[0];
- bp->bv2 = bi->bi_io_vec[0];
- bp->bv2.bv_offset += first_sectors << 9;
- bp->bv2.bv_len -= first_sectors << 9;
- bp->bv1.bv_len = first_sectors << 9;
+ if (bi->bi_vcnt != 0) {
+ bp->bv1 = bi->bi_io_vec[0];
+ bp->bv2 = bi->bi_io_vec[0];
+ bp->bv2.bv_offset += first_sectors << 9;
+ bp->bv2.bv_len -= first_sectors << 9;
+ bp->bv1.bv_len = first_sectors << 9;

- bp->bio1.bi_io_vec = &bp->bv1;
- bp->bio2.bi_io_vec = &bp->bv2;
+ bp->bio1.bi_io_vec = &bp->bv1;
+ bp->bio2.bi_io_vec = &bp->bv2;

- bp->bio1.bi_max_vecs = 1;
- bp->bio2.bi_max_vecs = 1;
+ bp->bio1.bi_max_vecs = 1;
+ bp->bio2.bi_max_vecs = 1;
+ }

bp->bio1.bi_end_io = bio_pair_end_1;
bp->bio2.bi_end_io = bio_pair_end_2;[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2012-09-24 07:21    [W:0.101 / U:13.656 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site