linux-kernel - Re: status of block-integrity

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sun, 22 Dec 2013 12:45:55 -0800
From:	"Nicholas A. Bellinger" <nab@...ux-iscsi.org>
To:	Christoph Hellwig <hch@...radead.org>
Cc:	"Martin K. Petersen" <martin.petersen@...cle.com>,
	Jens Axboe <axboe@...nel.dk>, linux-kernel@...r.kernel.org,
	linux-scsi@...r.kernel.org
Subject: Re: status of block-integrity

On Sun, 2013-12-22 at 11:21 -0800, Christoph Hellwig wrote:
> We have the block integrity code to support DIF/DIX in the the tree for
> about 5 and a half years, and we still don't have a single consumer of
> it.  By normal kernel rules it should never have been merged, or at
> least the bitrot long removed.

Is not sd_dif.c a consumer of blk_integrity.c logic..?

> Given that we'll have a lot of work to do in this area with block
> multiqueue I think it's time to either kill it off for good or make sure
> we can actually use and test it.

Speak of the devil..

I've been working on enabling DIF support in scsi-mq recently, and
AFAICT the only part that is required in blk-mq for DIF emulation to
function with scsi-debug is the following patch.

commit 1428a390cc16025f93905852777d4afd8aeba05d
Author: Nicholas Bellinger <nab@...ux-iscsi.org>
Date:   Sun Dec 22 11:58:49 2013 +0000

    blk-mq: Add bio_integrity setup to blk_mq_make_request
    
    This patch adds the missing bio_integrity_enabled() +
    bio_integrity_prep() setup into blk_mq_make_request()
    in order to use DIF protection with scsi-mq.
    
    Cc: Jens Axboe <axboe@...nel.dk>
    Cc: Martin K. Petersen <martin.petersen@...cle.com>
    Signed-off-by: Nicholas Bellinger <nab@...ux-iscsi.org>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index c79126e..a520c39 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -916,6 +916,11 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
 
        blk_queue_bounce(q, &bio);
 
+       if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
+               bio_endio(bio, -EIO);
+               return;
+       }
+
        if (use_plug && blk_attempt_plug_merge(q, bio, &request_count))
                return;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/