drbd: fix list corruption (recent regression)

The commit 288f422ec1
 drbd: Track all IO requests on the TL, not writes only
moved a list_add_tail(req, ) into a region where req
may have just been freed due to conflict detection.

Fix this by adding a proper cleanup section for that code path.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This commit is contained in:
Lars Ellenberg 2010-07-09 23:28:10 +02:00 committed by Philipp Reisner
parent e756414f7d
commit d28fd092a5
1 changed files with 17 additions and 25 deletions

View File

@ -917,31 +917,8 @@ allocate_barrier:
/* check this request on the collision detection hash tables.
* if we have a conflict, just complete it here.
* THINK do we want to check reads, too? (I don't think so...) */
if (rw == WRITE && _req_conflicts(req)) {
/* this is a conflicting request.
* even though it may have been only _partially_
* overlapping with one of the currently pending requests,
* without even submitting or sending it, we will
* pretend that it was successfully served right now.
*/
if (local) {
bio_put(req->private_bio);
req->private_bio = NULL;
drbd_al_complete_io(mdev, req->sector);
put_ldev(mdev);
local = 0;
}
if (remote)
dec_ap_pending(mdev);
_drbd_end_io_acct(mdev, req);
/* THINK: do we want to fail it (-EIO), or pretend success? */
bio_endio(req->master_bio, 0);
req->master_bio = NULL;
dec_ap_bio(mdev);
drbd_req_free(req);
remote = 0;
}
if (rw == WRITE && _req_conflicts(req))
goto fail_conflicting;
list_add_tail(&req->tl_requests, &mdev->newest_tle->requests);
@ -976,6 +953,21 @@ allocate_barrier:
return 0;
fail_conflicting:
/* this is a conflicting request.
* even though it may have been only _partially_
* overlapping with one of the currently pending requests,
* without even submitting or sending it, we will
* pretend that it was successfully served right now.
*/
_drbd_end_io_acct(mdev, req);
spin_unlock_irq(&mdev->req_lock);
if (remote)
dec_ap_pending(mdev);
/* THINK: do we want to fail it (-EIO), or pretend success?
* this pretends success. */
err = 0;
fail_free_complete:
if (rw == WRITE && local)
drbd_al_complete_io(mdev, sector);