Fix corruption issue with dm-crypt on top of software raid5. Cancelled
readahead bio's that report no error, just have BIO_UPTODATE cleared
were reported as successful reads to the higher layers (and leaving
random content in the buffer cache). Already fixed in 2.6.19.
Signed-off-by: Christophe Saout <[email protected]>
--- linux-2.6.18.orig/drivers/md/dm-crypt.c 2006-09-20 05:42:06.000000000 +0200
+++ linux-2.6.18/drivers/md/dm-crypt.c 2006-12-02 03:03:36.000000000 +0100
@@ -717,13 +717,15 @@
if (bio->bi_size)
return 1;
+ if (!bio_flagged(bio, BIO_UPTODATE) && !error)
+ error = -EIO;
+
bio_put(bio);
/*
* successful reads are decrypted by the worker thread
*/
- if ((bio_data_dir(bio) == READ)
- && bio_flagged(bio, BIO_UPTODATE)) {
+ if (bio_data_dir(io->bio) == READ && !error) {
kcryptd_queue_io(io);
return 0;
}
[Note: please Cc: [email protected] on -stable patches]
* Christophe Saout ([email protected]) wrote:
> Fix corruption issue with dm-crypt on top of software raid5. Cancelled
> readahead bio's that report no error, just have BIO_UPTODATE cleared
> were reported as successful reads to the higher layers (and leaving
> random content in the buffer cache). Already fixed in 2.6.19.
I take it this is fixed a different way in 2.6.19? Mind clarifying the
difference?
> Signed-off-by: Christophe Saout <[email protected]>
>
>
> --- linux-2.6.18.orig/drivers/md/dm-crypt.c 2006-09-20 05:42:06.000000000 +0200
> +++ linux-2.6.18/drivers/md/dm-crypt.c 2006-12-02 03:03:36.000000000 +0100
> @@ -717,13 +717,15 @@
> if (bio->bi_size)
> return 1;
>
> + if (!bio_flagged(bio, BIO_UPTODATE) && !error)
> + error = -EIO;
> +
Minor nit: introduces trailing whitespaces, cleaned it up locally.
thanks,
-chris
--
This is a note to let you know that we have just queued up the patch titled
Subject: dm crypt: Fix data corruption with dm-crypt over RAID5
to the 2.6.18-stable tree. Its filename is
dm-crypt-fix-data-corruption-with-dm-crypt-over-raid5.patch
A git repo of this tree can be found at
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
>From linux-kernel-owner+chrisw=40sous-sol.org-S1162719AbWLBC2Z@vger.kernel.org Fri Dec 1 18:36:19 2006
Date: Sat, 02 Dec 2006 03:27:56 +0100
From: Christophe Saout <[email protected]>
To: [email protected]
Cc: [email protected], Andrey <[email protected]>, Andrew Morton <[email protected]>, [email protected], Neil Brown <[email protected]>, Jens Axboe <[email protected]>, Chris Wright <[email protected]>
Subject: dm crypt: Fix data corruption with dm-crypt over RAID5
Fix corruption issue with dm-crypt on top of software raid5. Cancelled
readahead bio's that report no error, just have BIO_UPTODATE cleared
were reported as successful reads to the higher layers (and leaving
random content in the buffer cache). Already fixed in 2.6.19.
Signed-off-by: Christophe Saout <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
drivers/md/dm-crypt.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- linux-2.6.18.5.orig/drivers/md/dm-crypt.c
+++ linux-2.6.18.5/drivers/md/dm-crypt.c
@@ -717,13 +717,15 @@ static int crypt_endio(struct bio *bio,
if (bio->bi_size)
return 1;
+ if (!bio_flagged(bio, BIO_UPTODATE) && !error)
+ error = -EIO;
+
bio_put(bio);
/*
* successful reads are decrypted by the worker thread
*/
- if ((bio_data_dir(bio) == READ)
- && bio_flagged(bio, BIO_UPTODATE)) {
+ if (bio_data_dir(io->bio) == READ && !error) {
kcryptd_queue_io(io);
return 0;
}
Am Freitag, den 01.12.2006, 19:49 -0800 schrieb Chris Wright:
> * Christophe Saout ([email protected]) wrote:
> > Fix corruption issue with dm-crypt on top of software raid5. Cancelled
> > readahead bio's that report no error, just have BIO_UPTODATE cleared
> > were reported as successful reads to the higher layers (and leaving
> > random content in the buffer cache). Already fixed in 2.6.19.
>
> I take it this is fixed a different way in 2.6.19? Mind clarifying the
> difference?
It's more or less fixed the same way in 2.6.19. The function was
reordered by Milan Broz to accommodate the changed write path (commit
8b004457168995f2ae2a35327f885183a9e74141):
> [PATCH] dm crypt: restructure for workqueue change
>
> Restructure part of the dm-crypt code in preparation for workqueue
> changes.
>
> Use 'base_bio' or 'clone' variable names consistently throughout. No
> functional changes are included in this patch.
"No functional changes" actually included the correct fix, accidental or
not.
> Minor nit: introduces trailing whitespaces, cleaned it up locally.
Ouch, sorry.
On Sat, 2006-12-02 at 03:27 +0100, Christophe Saout wrote:
Hi Christophe:
I'm wondering about trying out your patch with dm-crypt on 2.6.12.
The code in drivers/md/dm-crypt.c`crypt_endio() appears to be the same.
Is there a reason that this isn't necessary or would be a bad idea.
Looks like the existing code isn't checking the BIO_UPTODATE flag
before doing the bio_put(). Looks the the second part of not calling
kcryptd_queue_io() and forwarding the processing to the cryptd is
effectively the same. The 1st change will set error if BIO_UPTODATE
isn't set and that will cause the 2nd change to skip calling
kcryptd_queue_io().
I'm not sure about the change in the arg to bio_data_dir()
changing from bio to io->bio. Perhaps they are equivalent;
care to comment on that.
Unless I hear otherwise I'll try it out Tomorrow.
-piet
> Fix corruption issue with dm-crypt on top of software raid5. Cancelled
> readahead bio's that report no error, just have BIO_UPTODATE cleared
> were reported as successful reads to the higher layers (and leaving
> random content in the buffer cache). Already fixed in 2.6.19.
>
> Signed-off-by: Christophe Saout <[email protected]>
>
>
> --- linux-2.6.18.orig/drivers/md/dm-crypt.c 2006-09-20 05:42:06.000000000 +0200
> +++ linux-2.6.18/drivers/md/dm-crypt.c 2006-12-02 03:03:36.000000000 +0100
> @@ -717,13 +717,15 @@
> if (bio->bi_size)
> return 1;
>
> + if (!bio_flagged(bio, BIO_UPTODATE) && !error)
> + error = -EIO;
> +
> bio_put(bio);
>
> /*
> * successful reads are decrypted by the worker thread
> */
> - if ((bio_data_dir(bio) == READ)
> - && bio_flagged(bio, BIO_UPTODATE)) {
> + if (bio_data_dir(io->bio) == READ && !error) {
> kcryptd_queue_io(io);
> return 0;
> }
>
>
> --
> dm-devel mailing list
> [email protected]
> https://www.redhat.com/mailman/listinfo/dm-devel
--
Piet Delaney Phone: (408) 200-5256
Blue Lane Technologies Fax: (408) 200-5299
10450 Bubb Rd.
Cupertino, Ca. 95014 Email: [email protected]
Christophe Saout wrote:
> Fix corruption issue with dm-crypt on top of software raid5. Cancelled
> readahead bio's that report no error, just have BIO_UPTODATE cleared
> were reported as successful reads to the higher layers (and leaving
> random content in the buffer cache). Already fixed in 2.6.19.
>
> Signed-off-by: Christophe Saout <[email protected]>
>
>
> --- linux-2.6.18.orig/drivers/md/dm-crypt.c 2006-09-20 05:42:06.000000000
> +0200
> +++ linux-2.6.18/drivers/md/dm-crypt.c 2006-12-02 03:03:36.000000000 +0100
> @@ -717,13 +717,15 @@
> if (bio->bi_size)
> return 1;
>
> + if (!bio_flagged(bio, BIO_UPTODATE) && !error)
> + error = -EIO;
> +
> bio_put(bio);
>
> /*
> * successful reads are decrypted by the worker thread
> */
> - if ((bio_data_dir(bio) == READ)
> - && bio_flagged(bio, BIO_UPTODATE)) {
> + if (bio_data_dir(io->bio) == READ && !error) {
> kcryptd_queue_io(io);
Why doesn't kcryptd_queue_io() check the return value from queue_work()?
476 static void kcryptd_queue_io(struct crypt_io *io)
477 {
478 INIT_WORK(&io->work, kcryptd_do_work, io);
479 queue_work(_kcryptd_workqueue, &io->work);
480 }
-piet
> return 0;
> }