Re: Bio & Biovec-1 increasing cache size, never freed during disk IO

Neil Brown
2006-03-02T06:13:44Z

On Wednesday March 1, mbrancaleoni@gmail.com wrote:
> Hi Neil.
>
> unfortunately the patch does nothing, the problem persists.
> Tested with 2.6.16-rc5.
> (I've double checked if the patch was applied correctly)
>
> Can I do anything to be of some more help?

Yes, try another patch. :-) and tell me if you have CONFIG_DEBUG_SLAB
set... there was another use-after-free bug which CONFIG_DEBUG_SLAB
would have made worse.

This patch should fix it all up.

Thanks again,
NeilBrown

Signed-off-by: Neil Brown <neilb@suse.de>

### Diffstat output
./drivers/md/raid1.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff ./drivers/md/raid1.c~current~ ./drivers/md/raid1.c
--- ./drivers/md/raid1.c~current~ 2006-02-27 11:52:18.000000000 +1100
+++ ./drivers/md/raid1.c 2006-03-01 10:44:49.000000000 +1100
@@ -306,6 +306,7 @@ static int raid1_end_write_request(struc
r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
conf_t *conf = mddev_to_conf(r1_bio->mddev);
+ struct bio *to_put = NULL;

if (bio->bi_size)
return 1;
@@ -323,6 +324,7 @@ static int raid1_end_write_request(struc
* this branch is our 'one mirror IO has finished' event handler:
*/
r1_bio->bios[mirror] = NULL;
+ to_put = bio;
if (!uptodate) {
md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
/* an I/O failed, we can't clear the bitmap */
@@ -375,7 +377,7 @@ static int raid1_end_write_request(struc
/* Don't dec_pending yet, we want to hold
* the reference over the retry
*/
- return 0;
+ goto out;
}
if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
/* free extra copy of the data pages */
@@ -392,10 +394,11 @@ static int raid1_end_write_request(struc
raid_end_bio_io(r1_bio);
}

- if (r1_bio->bios[mirror]==NULL)
- bio_put(bio);
-
rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
+ out:
+ if (to_put)
+ bio_put(to_put);
+
return 0;
}

@@ -857,7 +860,7 @@ static int make_request(request_queue_t
atomic_set(&r1_bio->remaining, 0);
atomic_set(&r1_bio->behind_remaining, 0);

- do_barriers = bio->bi_rw & BIO_RW_BARRIER;
+ do_barriers = bio_barrier(bio);
if (do_barriers)
set_bit(R1BIO_Barrier, &r1_bio->state);