@@ -7,45 +7,61 @@
#include "rxe.h"
#include "rxe_loc.h"
+/* caller should hold mc_grp_pool->pool_lock */
+static struct rxe_mc_grp *create_grp(struct rxe_dev *rxe,
+ struct rxe_pool *pool,
+ union ib_gid *mgid)
+{
+ int err;
+ struct rxe_mc_grp *grp;
+
+ grp = rxe_alloc_nl(&rxe->mc_grp_pool);
+ if (!grp)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&grp->qp_list);
+ spin_lock_init(&grp->mcg_lock);
+ grp->rxe = rxe;
+ rxe_add_key_nl(grp, mgid);
+
+ err = rxe_mcast_add(rxe, mgid);
+ if (unlikely(err)) {
+ rxe_drop_key_nl(grp);
+ rxe_drop_ref(grp);
+ return ERR_PTR(err);
+ }
+
+ return grp;
+}
+
int rxe_mcast_get_grp(struct rxe_dev *rxe, union ib_gid *mgid,
struct rxe_mc_grp **grp_p)
{
int err;
struct rxe_mc_grp *grp;
+ struct rxe_pool *pool = &rxe->mc_grp_pool;
+ unsigned long flags;
- if (rxe->attr.max_mcast_qp_attach == 0) {
- err = -EINVAL;
- goto err1;
- }
+ if (rxe->attr.max_mcast_qp_attach == 0)
+ return -EINVAL;
- grp = rxe_pool_get_key(&rxe->mc_grp_pool, mgid);
+ write_lock_irqsave(&pool->pool_lock, flags);
+
+ grp = rxe_pool_get_key_nl(pool, mgid);
if (grp)
goto done;
- grp = rxe_alloc(&rxe->mc_grp_pool);
- if (!grp) {
- err = -ENOMEM;
- goto err1;
+ grp = create_grp(rxe, pool, mgid);
+ if (IS_ERR(grp)) {
+ write_unlock_irqrestore(&pool->pool_lock, flags);
+ err = PTR_ERR(grp);
+ return err;
}
- INIT_LIST_HEAD(&grp->qp_list);
- spin_lock_init(&grp->mcg_lock);
- grp->rxe = rxe;
-
- rxe_add_key(grp, mgid);
-
- err = rxe_mcast_add(rxe, mgid);
- if (err)
- goto err2;
-
done:
+ write_unlock_irqrestore(&pool->pool_lock, flags);
*grp_p = grp;
return 0;
-
-err2:
- rxe_drop_ref(grp);
-err1:
- return err;
}
int rxe_mcast_add_grp_elem(struct rxe_dev *rxe, struct rxe_qp *qp,
Fix a race in rxe_mcast.c that occurs when two QPs try at the same time to attach a multicast address. Both QPs lookup the mgid address in a pool of multicast groups and if they do not find it create a new group elem. Fix this by locking the lookup/alloc/add key sequence and using the unlocked APIs added in this patch set. Signed-off-by: Bob Pearson <rpearson@hpe.com> --- drivers/infiniband/sw/rxe/rxe_mcast.c | 64 +++++++++++++++++---------- 1 file changed, 40 insertions(+), 24 deletions(-)