diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/infiniband/core/rdma_core.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c index bf8e149d3191..e0a5e897e4b1 100644 --- a/drivers/infiniband/core/rdma_core.c +++ b/drivers/infiniband/core/rdma_core.c @@ -153,9 +153,9 @@ static int uverbs_destroy_uobject(struct ib_uobject *uobj, uobj->context = NULL; /* - * For DESTROY the usecnt is held write locked, the caller is expected - * to put it unlock and put the object when done with it. Only DESTROY - * can remove the IDR handle. + * For DESTROY the usecnt is not changed, the caller is expected to + * manage it via uobj_put_destroy(). Only DESTROY can remove the IDR + * handle. */ if (reason != RDMA_REMOVE_DESTROY) atomic_set(&uobj->usecnt, 0); @@ -187,7 +187,7 @@ static int uverbs_destroy_uobject(struct ib_uobject *uobj, /* * This calls uverbs_destroy_uobject() using the RDMA_REMOVE_DESTROY * sequence. It should only be used from command callbacks. On success the - * caller must pair this with rdma_lookup_put_uobject(LOOKUP_WRITE). This + * caller must pair this with uobj_put_destroy(). This * version requires the caller to have already obtained an * LOOKUP_DESTROY uobject kref. */ @@ -198,6 +198,13 @@ int uobj_destroy(struct ib_uobject *uobj, struct uverbs_attr_bundle *attrs) down_read(&ufile->hw_destroy_rwsem); + /* + * Once the uobject is destroyed by RDMA_REMOVE_DESTROY then it is left + * write locked as the callers put it back with UVERBS_LOOKUP_DESTROY. + * This is because any other concurrent thread can still see the object + * in the xarray due to RCU. Leaving it locked ensures nothing else will + * touch it. + */ ret = uverbs_try_lock_object(uobj, UVERBS_LOOKUP_WRITE); if (ret) goto out_unlock; @@ -216,7 +223,7 @@ out_unlock: /* * uobj_get_destroy destroys the HW object and returns a handle to the uobj * with a NULL object pointer. The caller must pair this with - * uverbs_put_destroy. + * uobj_put_destroy(). */ struct ib_uobject *__uobj_get_destroy(const struct uverbs_api_object *obj, u32 id, struct uverbs_attr_bundle *attrs) @@ -250,8 +257,7 @@ int __uobj_perform_destroy(const struct uverbs_api_object *obj, u32 id, uobj = __uobj_get_destroy(obj, id, attrs); if (IS_ERR(uobj)) return PTR_ERR(uobj); - - rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_WRITE); + uobj_put_destroy(uobj); return 0; } |