rxe_mcast.c currently uses _irqsave spinlocks for rxe->mcg_lock
while rxe_recv.c uses _bh spinlocks for the same lock. Adding
tracing shows that the code in rxe_mcast.c is all executed in_task()
context while the code in rxe_recv.c that refers to the lock
executes in softirq context. This causes a lockdep warning in code
that executes multicast I/O including blktests check srp.
Change the locking of rxe->mcg_lock in rxe_mcast.c to use
spin_(un)lock_bh().
With this change the following locks in rdma_rxe which are all _bh
show no lockdep warnings.
atomic_ops_lock
mw->lock
port->port_lock
qp->state_lock
rxe->mcg_lock
rxe->mmap_offset_lock
rxe->pending_lock
task->state_lock
The only other remaining lock is pool->xa.xa_lock which
must either be some combination of _bh and _irq types depending
on the object type (== ah or not) or plain spin_lock if
the read side operations are converted to use rcu_read_lock().
Fixes: 6090a0c4c7c6 ("RDMA/rxe: Cleanup rxe_mcast.c")
Signed-off-by: Bob Pearson <rpearsonhpe@xxxxxxxxx>
---
drivers/infiniband/sw/rxe/rxe_mcast.c | 36 +++++++++++----------------
1 file changed, 15 insertions(+), 21 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_mcast.c b/drivers/infiniband/sw/rxe/rxe_mcast.c
index ae8f11cb704a..7f50566b8d89 100644
--- a/drivers/infiniband/sw/rxe/rxe_mcast.c
+++ b/drivers/infiniband/sw/rxe/rxe_mcast.c
@@ -143,11 +143,10 @@ static struct rxe_mcg *__rxe_lookup_mcg(struct rxe_dev *rxe,
struct rxe_mcg *rxe_lookup_mcg(struct rxe_dev *rxe, union ib_gid *mgid)
{
struct rxe_mcg *mcg;
- unsigned long flags;
- spin_lock_irqsave(&rxe->mcg_lock, flags);
+ spin_lock_bh(&rxe->mcg_lock);
mcg = __rxe_lookup_mcg(rxe, mgid);
- spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+ spin_unlock_bh(&rxe->mcg_lock);
return mcg;
}
@@ -198,7 +197,6 @@ static int __rxe_init_mcg(struct rxe_dev *rxe, union ib_gid *mgid,
static struct rxe_mcg *rxe_get_mcg(struct rxe_dev *rxe, union ib_gid *mgid)
{
struct rxe_mcg *mcg, *tmp;
- unsigned long flags;
int err;
if (rxe->attr.max_mcast_grp == 0)
@@ -214,7 +212,7 @@ static struct rxe_mcg *rxe_get_mcg(struct rxe_dev *rxe, union ib_gid *mgid)
if (!mcg)
return ERR_PTR(-ENOMEM);
- spin_lock_irqsave(&rxe->mcg_lock, flags);
+ spin_lock_bh(&rxe->mcg_lock);
/* re-check to see if someone else just added it */
tmp = __rxe_lookup_mcg(rxe, mgid);
if (tmp) {
@@ -232,12 +230,12 @@ static struct rxe_mcg *rxe_get_mcg(struct rxe_dev *rxe, union ib_gid *mgid)
if (err)
goto err_dec;
out:
- spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+ spin_unlock_bh(&rxe->mcg_lock);
return mcg;
err_dec:
atomic_dec(&rxe->mcg_num);
- spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+ spin_unlock_bh(&rxe->mcg_lock);
kfree(mcg);
return ERR_PTR(err);
}
@@ -280,11 +278,9 @@ static void __rxe_destroy_mcg(struct rxe_mcg *mcg)
*/
static void rxe_destroy_mcg(struct rxe_mcg *mcg)
{
- unsigned long flags;
-
- spin_lock_irqsave(&mcg->rxe->mcg_lock, flags);
+ spin_lock_bh(&mcg->rxe->mcg_lock);
__rxe_destroy_mcg(mcg);
- spin_unlock_irqrestore(&mcg->rxe->mcg_lock, flags);
+ spin_unlock_bh(&mcg->rxe->mcg_lock);
}
/**
@@ -339,25 +335,24 @@ static int rxe_attach_mcg(struct rxe_mcg *mcg, struct rxe_qp *qp)
{
struct rxe_dev *rxe = mcg->rxe;
struct rxe_mca *mca, *tmp;
- unsigned long flags;
int err;
/* check to see if the qp is already a member of the group */
- spin_lock_irqsave(&rxe->mcg_lock, flags);
+ spin_lock_bh(&rxe->mcg_lock);
list_for_each_entry(mca, &mcg->qp_list, qp_list) {
if (mca->qp == qp) {
- spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+ spin_unlock_bh(&rxe->mcg_lock);
return 0;
}
}
- spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+ spin_unlock_bh(&rxe->mcg_lock);
/* speculative alloc new mca without using GFP_ATOMIC */
mca = kzalloc(sizeof(*mca), GFP_KERNEL);
if (!mca)
return -ENOMEM;
- spin_lock_irqsave(&rxe->mcg_lock, flags);
+ spin_lock_bh(&rxe->mcg_lock);
/* re-check to see if someone else just attached qp */
list_for_each_entry(tmp, &mcg->qp_list, qp_list) {
if (tmp->qp == qp) {
@@ -371,7 +366,7 @@ static int rxe_attach_mcg(struct rxe_mcg *mcg, struct rxe_qp *qp)
if (err)
kfree(mca);
out:
- spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+ spin_unlock_bh(&rxe->mcg_lock);
return err;
}
@@ -405,9 +400,8 @@ static int rxe_detach_mcg(struct rxe_mcg *mcg, struct rxe_qp *qp)
{
struct rxe_dev *rxe = mcg->rxe;
struct rxe_mca *mca, *tmp;
- unsigned long flags;
- spin_lock_irqsave(&rxe->mcg_lock, flags);
+ spin_lock_bh(&rxe->mcg_lock);
list_for_each_entry_safe(mca, tmp, &mcg->qp_list, qp_list) {
if (mca->qp == qp) {
__rxe_cleanup_mca(mca, mcg);
@@ -421,13 +415,13 @@ static int rxe_detach_mcg(struct rxe_mcg *mcg, struct rxe_qp *qp)
if (atomic_read(&mcg->qp_num) <= 0)
__rxe_destroy_mcg(mcg);
- spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+ spin_unlock_bh(&rxe->mcg_lock);
return 0;
}
}
/* we didn't find the qp on the list */
- spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+ spin_unlock_bh(&rxe->mcg_lock);
return -EINVAL;
}
--
2.32.0
