diff options
Diffstat (limited to 'drivers/infiniband/core/rdma_core.c')
| -rw-r--r-- | drivers/infiniband/core/rdma_core.c | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c index ccf4d069c25c..d0580eed3bcb 100644 --- a/drivers/infiniband/core/rdma_core.c +++ b/drivers/infiniband/core/rdma_core.c @@ -160,9 +160,9 @@ 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); @@ -194,7 +194,7 @@ 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. */ @@ -205,6 +205,13 @@ 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; @@ -223,7 +230,7 @@ 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) @@ -257,8 +264,7 @@ 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; } @@ -362,7 +368,7 @@ lookup_get_fd_uobject(const struct uverbs_api_object *obj, * and the caller is expected to ensure that uverbs_close_fd is never * done while a call top lookup is possible. */ - if (f->f_op != fd_type->fops) { + if (f->f_op != fd_type->fops || uobject->ufile != ufile) { fput(f); return ERR_PTR(-EBADF); } @@ -689,7 +695,6 @@ void rdma_lookup_put_uobject(struct ib_uobject *uobj, enum rdma_lookup_mode mode) { assert_uverbs_usecnt(uobj, mode); - uobj->uapi_object->type_class->lookup_put(uobj, mode); /* * In order to unlock an object, either decrease its usecnt for * read access or zero it in case of exclusive access. See @@ -706,6 +711,7 @@ void rdma_lookup_put_uobject(struct ib_uobject *uobj, break; } + uobj->uapi_object->type_class->lookup_put(uobj, mode); /* Pairs with the kref obtained by type->lookup_get */ uverbs_uobject_put(uobj); } |