From: Jason Gunthorpe Date: Wed, 4 Nov 2020 21:40:59 +0000 (-0400) Subject: RDMA/cm: Make the local_id_table xarray non-irq X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=eb73060b971aa04e4f7421b8c9c0363918608b72;p=linux.git RDMA/cm: Make the local_id_table xarray non-irq The xarray is never mutated from an IRQ handler, only from work queues under a spinlock_irq. Thus there is no reason for it be an IRQ type xarray. This was copied over from the original IDR code, but the recent rework put the xarray inside another spinlock_irq which will unbalance the unlocking. Fixes: c206f8bad15d ("RDMA/cm: Make it clearer how concurrency works in cm_req_handler()") Link: https://lore.kernel.org/r/0-v1-808b6da3bd3f+1857-cm_xarray_no_irq_jgg@nvidia.com Reported-by: Matthew Wilcox Signed-off-by: Jason Gunthorpe --- diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c index 5740d1ba35687..012156624b829 100644 --- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -859,8 +859,8 @@ static struct cm_id_private *cm_alloc_id_priv(struct ib_device *device, atomic_set(&cm_id_priv->work_count, -1); refcount_set(&cm_id_priv->refcount, 1); - ret = xa_alloc_cyclic_irq(&cm.local_id_table, &id, NULL, xa_limit_32b, - &cm.local_id_next, GFP_KERNEL); + ret = xa_alloc_cyclic(&cm.local_id_table, &id, NULL, xa_limit_32b, + &cm.local_id_next, GFP_KERNEL); if (ret < 0) goto error; cm_id_priv->id.local_id = (__force __be32)id ^ cm.random_id_operand; @@ -878,8 +878,8 @@ error: */ static void cm_finalize_id(struct cm_id_private *cm_id_priv) { - xa_store_irq(&cm.local_id_table, cm_local_id(cm_id_priv->id.local_id), - cm_id_priv, GFP_KERNEL); + xa_store(&cm.local_id_table, cm_local_id(cm_id_priv->id.local_id), + cm_id_priv, GFP_ATOMIC); } struct ib_cm_id *ib_create_cm_id(struct ib_device *device, @@ -1169,7 +1169,7 @@ retest: spin_unlock(&cm.lock); spin_unlock_irq(&cm_id_priv->lock); - xa_erase_irq(&cm.local_id_table, cm_local_id(cm_id->local_id)); + xa_erase(&cm.local_id_table, cm_local_id(cm_id->local_id)); cm_deref_id(cm_id_priv); wait_for_completion(&cm_id_priv->comp); while ((work = cm_dequeue_work(cm_id_priv)) != NULL) @@ -4482,7 +4482,7 @@ static int __init ib_cm_init(void) cm.remote_id_table = RB_ROOT; cm.remote_qp_table = RB_ROOT; cm.remote_sidr_table = RB_ROOT; - xa_init_flags(&cm.local_id_table, XA_FLAGS_ALLOC | XA_FLAGS_LOCK_IRQ); + xa_init_flags(&cm.local_id_table, XA_FLAGS_ALLOC); get_random_bytes(&cm.random_id_operand, sizeof cm.random_id_operand); INIT_LIST_HEAD(&cm.timewait_list);