From a115413de13ae6beb0cbfc198afe385a261ab284 Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Sat, 13 Nov 2010 20:42:29 +0100 Subject: [PATCH] drbd: fix for spin_lock_irqsave in endio callback In commit 9b7f76dc37919ea36caa9680a3f765e5b19b25fb, Author: Lars Ellenberg Date: Wed Aug 11 23:40:24 2010 +0200 drbd: new configuration parameter c-min-rate a bad chunk slipped through, which is now reverted as well, restoring the correct irqsave for the endio callback. This patch also add comments at both req_mod() and in the endio callback so it should not happen again. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_req.h | 3 ++- drivers/block/drbd/drbd_worker.c | 10 +++++++++- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h index 181ea0364822..ab2bd09d54b4 100644 --- a/drivers/block/drbd/drbd_req.h +++ b/drivers/block/drbd/drbd_req.h @@ -339,7 +339,8 @@ static inline int _req_mod(struct drbd_request *req, enum drbd_req_event what) } /* completion of master bio is outside of spinlock. - * If you need it irqsave, do it your self! */ + * If you need it irqsave, do it your self! + * Which means: don't use from bio endio callback. */ static inline int req_mod(struct drbd_request *req, enum drbd_req_event what) { diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 47d223c2409c..34f224b018b3 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -193,8 +193,10 @@ void drbd_endio_sec(struct bio *bio, int error) */ void drbd_endio_pri(struct bio *bio, int error) { + unsigned long flags; struct drbd_request *req = bio->bi_private; struct drbd_conf *mdev = req->mdev; + struct bio_and_error m; enum drbd_req_event what; int uptodate = bio_flagged(bio, BIO_UPTODATE); @@ -220,7 +222,13 @@ void drbd_endio_pri(struct bio *bio, int error) bio_put(req->private_bio); req->private_bio = ERR_PTR(error); - req_mod(req, what); + /* not req_mod(), we need irqsave here! */ + spin_lock_irqsave(&mdev->req_lock, flags); + __req_mod(req, what, &m); + spin_unlock_irqrestore(&mdev->req_lock, flags); + + if (m.bio) + complete_master_bio(mdev, &m); } int w_read_retry_remote(struct drbd_conf *mdev, struct drbd_work *w, int cancel)