994 строки
26 KiB
C
994 строки
26 KiB
C
/*
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* Copyright (c) 2016, Mellanox Technologies inc. All rights reserved.
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*
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* This software is available to you under a choice of one of two
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* licenses. You may choose to be licensed under the terms of the GNU
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* General Public License (GPL) Version 2, available from the file
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* COPYING in the main directory of this source tree, or the
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* OpenIB.org BSD license below:
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*
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* Redistribution and use in source and binary forms, with or
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* without modification, are permitted provided that the following
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* conditions are met:
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*
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* - Redistributions of source code must retain the above
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* copyright notice, this list of conditions and the following
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* disclaimer.
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*
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* - Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#include <linux/file.h>
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#include <linux/anon_inodes.h>
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#include <linux/sched/mm.h>
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#include <rdma/ib_verbs.h>
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#include <rdma/uverbs_types.h>
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#include <linux/rcupdate.h>
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#include <rdma/uverbs_ioctl.h>
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#include <rdma/rdma_user_ioctl.h>
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#include "uverbs.h"
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#include "core_priv.h"
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#include "rdma_core.h"
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void uverbs_uobject_get(struct ib_uobject *uobject)
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{
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kref_get(&uobject->ref);
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}
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static void uverbs_uobject_free(struct kref *ref)
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{
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struct ib_uobject *uobj =
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container_of(ref, struct ib_uobject, ref);
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if (uobj->uapi_object->type_class->needs_kfree_rcu)
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kfree_rcu(uobj, rcu);
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else
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kfree(uobj);
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}
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void uverbs_uobject_put(struct ib_uobject *uobject)
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{
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kref_put(&uobject->ref, uverbs_uobject_free);
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}
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static int uverbs_try_lock_object(struct ib_uobject *uobj,
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enum rdma_lookup_mode mode)
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{
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/*
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* When a shared access is required, we use a positive counter. Each
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* shared access request checks that the value != -1 and increment it.
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* Exclusive access is required for operations like write or destroy.
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* In exclusive access mode, we check that the counter is zero (nobody
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* claimed this object) and we set it to -1. Releasing a shared access
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* lock is done simply by decreasing the counter. As for exclusive
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* access locks, since only a single one of them is is allowed
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* concurrently, setting the counter to zero is enough for releasing
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* this lock.
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*/
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switch (mode) {
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case UVERBS_LOOKUP_READ:
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return atomic_fetch_add_unless(&uobj->usecnt, 1, -1) == -1 ?
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-EBUSY : 0;
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case UVERBS_LOOKUP_WRITE:
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/* lock is exclusive */
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return atomic_cmpxchg(&uobj->usecnt, 0, -1) == 0 ? 0 : -EBUSY;
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case UVERBS_LOOKUP_DESTROY:
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return 0;
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}
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return 0;
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}
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static void assert_uverbs_usecnt(struct ib_uobject *uobj,
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enum rdma_lookup_mode mode)
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{
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#ifdef CONFIG_LOCKDEP
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switch (mode) {
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case UVERBS_LOOKUP_READ:
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WARN_ON(atomic_read(&uobj->usecnt) <= 0);
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break;
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case UVERBS_LOOKUP_WRITE:
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WARN_ON(atomic_read(&uobj->usecnt) != -1);
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break;
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case UVERBS_LOOKUP_DESTROY:
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break;
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}
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#endif
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}
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/*
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* This must be called with the hw_destroy_rwsem locked for read or write,
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* also the uobject itself must be locked for write.
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*
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* Upon return the HW object is guaranteed to be destroyed.
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*
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* For RDMA_REMOVE_ABORT, the hw_destroy_rwsem is not required to be held,
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* however the type's allocat_commit function cannot have been called and the
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* uobject cannot be on the uobjects_lists
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*
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* For RDMA_REMOVE_DESTROY the caller shold be holding a kref (eg via
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* rdma_lookup_get_uobject) and the object is left in a state where the caller
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* needs to call rdma_lookup_put_uobject.
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*
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* For all other destroy modes this function internally unlocks the uobject
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* and consumes the kref on the uobj.
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*/
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static int uverbs_destroy_uobject(struct ib_uobject *uobj,
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enum rdma_remove_reason reason)
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{
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struct ib_uverbs_file *ufile = uobj->ufile;
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unsigned long flags;
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int ret;
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lockdep_assert_held(&ufile->hw_destroy_rwsem);
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assert_uverbs_usecnt(uobj, UVERBS_LOOKUP_WRITE);
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if (uobj->object) {
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ret = uobj->uapi_object->type_class->destroy_hw(uobj, reason);
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if (ret) {
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if (ib_is_destroy_retryable(ret, reason, uobj))
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return ret;
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/* Nothing to be done, dangle the memory and move on */
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WARN(true,
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"ib_uverbs: failed to remove uobject id %d, driver err=%d",
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uobj->id, ret);
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}
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uobj->object = NULL;
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}
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if (reason == RDMA_REMOVE_ABORT) {
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WARN_ON(!list_empty(&uobj->list));
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WARN_ON(!uobj->context);
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uobj->uapi_object->type_class->alloc_abort(uobj);
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}
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uobj->context = NULL;
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/*
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* For DESTROY the usecnt is held write locked, the caller is expected
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* to put it unlock and put the object when done with it. Only DESTROY
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* can remove the IDR handle.
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*/
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if (reason != RDMA_REMOVE_DESTROY)
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atomic_set(&uobj->usecnt, 0);
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else
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uobj->uapi_object->type_class->remove_handle(uobj);
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if (!list_empty(&uobj->list)) {
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spin_lock_irqsave(&ufile->uobjects_lock, flags);
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list_del_init(&uobj->list);
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spin_unlock_irqrestore(&ufile->uobjects_lock, flags);
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/*
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* Pairs with the get in rdma_alloc_commit_uobject(), could
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* destroy uobj.
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*/
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uverbs_uobject_put(uobj);
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}
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/*
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* When aborting the stack kref remains owned by the core code, and is
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* not transferred into the type. Pairs with the get in alloc_uobj
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*/
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if (reason == RDMA_REMOVE_ABORT)
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uverbs_uobject_put(uobj);
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return 0;
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}
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/*
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* This calls uverbs_destroy_uobject() using the RDMA_REMOVE_DESTROY
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* sequence. It should only be used from command callbacks. On success the
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* caller must pair this with rdma_lookup_put_uobject(LOOKUP_WRITE). This
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* version requires the caller to have already obtained an
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* LOOKUP_DESTROY uobject kref.
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*/
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int uobj_destroy(struct ib_uobject *uobj)
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{
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struct ib_uverbs_file *ufile = uobj->ufile;
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int ret;
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down_read(&ufile->hw_destroy_rwsem);
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ret = uverbs_try_lock_object(uobj, UVERBS_LOOKUP_WRITE);
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if (ret)
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goto out_unlock;
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ret = uverbs_destroy_uobject(uobj, RDMA_REMOVE_DESTROY);
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if (ret) {
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atomic_set(&uobj->usecnt, 0);
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goto out_unlock;
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}
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out_unlock:
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up_read(&ufile->hw_destroy_rwsem);
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return ret;
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}
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/*
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* uobj_get_destroy destroys the HW object and returns a handle to the uobj
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* with a NULL object pointer. The caller must pair this with
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* uverbs_put_destroy.
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*/
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struct ib_uobject *__uobj_get_destroy(const struct uverbs_api_object *obj,
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u32 id, struct ib_uverbs_file *ufile)
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{
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struct ib_uobject *uobj;
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int ret;
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uobj = rdma_lookup_get_uobject(obj, ufile, id, UVERBS_LOOKUP_DESTROY);
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if (IS_ERR(uobj))
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return uobj;
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ret = uobj_destroy(uobj);
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if (ret) {
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rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_DESTROY);
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return ERR_PTR(ret);
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}
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return uobj;
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}
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/*
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* Does both uobj_get_destroy() and uobj_put_destroy(). Returns success_res
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* on success (negative errno on failure). For use by callers that do not need
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* the uobj.
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*/
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int __uobj_perform_destroy(const struct uverbs_api_object *obj, u32 id,
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struct ib_uverbs_file *ufile, int success_res)
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{
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struct ib_uobject *uobj;
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uobj = __uobj_get_destroy(obj, id, ufile);
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if (IS_ERR(uobj))
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return PTR_ERR(uobj);
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rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_WRITE);
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return success_res;
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}
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/* alloc_uobj must be undone by uverbs_destroy_uobject() */
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static struct ib_uobject *alloc_uobj(struct ib_uverbs_file *ufile,
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const struct uverbs_api_object *obj)
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{
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struct ib_uobject *uobj;
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struct ib_ucontext *ucontext;
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ucontext = ib_uverbs_get_ucontext(ufile);
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if (IS_ERR(ucontext))
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return ERR_CAST(ucontext);
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uobj = kzalloc(obj->type_attrs->obj_size, GFP_KERNEL);
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if (!uobj)
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return ERR_PTR(-ENOMEM);
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/*
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* user_handle should be filled by the handler,
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* The object is added to the list in the commit stage.
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*/
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uobj->ufile = ufile;
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uobj->context = ucontext;
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INIT_LIST_HEAD(&uobj->list);
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uobj->uapi_object = obj;
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/*
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* Allocated objects start out as write locked to deny any other
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* syscalls from accessing them until they are committed. See
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* rdma_alloc_commit_uobject
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*/
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atomic_set(&uobj->usecnt, -1);
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kref_init(&uobj->ref);
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return uobj;
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}
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static int idr_add_uobj(struct ib_uobject *uobj)
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{
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int ret;
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idr_preload(GFP_KERNEL);
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spin_lock(&uobj->ufile->idr_lock);
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/*
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* We start with allocating an idr pointing to NULL. This represents an
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* object which isn't initialized yet. We'll replace it later on with
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* the real object once we commit.
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*/
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ret = idr_alloc(&uobj->ufile->idr, NULL, 0,
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min_t(unsigned long, U32_MAX - 1, INT_MAX), GFP_NOWAIT);
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if (ret >= 0)
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uobj->id = ret;
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spin_unlock(&uobj->ufile->idr_lock);
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idr_preload_end();
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return ret < 0 ? ret : 0;
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}
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/* Returns the ib_uobject or an error. The caller should check for IS_ERR. */
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static struct ib_uobject *
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lookup_get_idr_uobject(const struct uverbs_api_object *obj,
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struct ib_uverbs_file *ufile, s64 id,
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enum rdma_lookup_mode mode)
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{
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struct ib_uobject *uobj;
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unsigned long idrno = id;
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if (id < 0 || id > ULONG_MAX)
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return ERR_PTR(-EINVAL);
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rcu_read_lock();
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/* object won't be released as we're protected in rcu */
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uobj = idr_find(&ufile->idr, idrno);
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if (!uobj) {
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uobj = ERR_PTR(-ENOENT);
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goto free;
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}
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/*
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* The idr_find is guaranteed to return a pointer to something that
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* isn't freed yet, or NULL, as the free after idr_remove goes through
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* kfree_rcu(). However the object may still have been released and
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* kfree() could be called at any time.
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*/
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if (!kref_get_unless_zero(&uobj->ref))
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uobj = ERR_PTR(-ENOENT);
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free:
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rcu_read_unlock();
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return uobj;
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}
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static struct ib_uobject *
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lookup_get_fd_uobject(const struct uverbs_api_object *obj,
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struct ib_uverbs_file *ufile, s64 id,
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enum rdma_lookup_mode mode)
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{
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const struct uverbs_obj_fd_type *fd_type;
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struct file *f;
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struct ib_uobject *uobject;
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int fdno = id;
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if (fdno != id)
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return ERR_PTR(-EINVAL);
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if (mode != UVERBS_LOOKUP_READ)
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return ERR_PTR(-EOPNOTSUPP);
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if (!obj->type_attrs)
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return ERR_PTR(-EIO);
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fd_type =
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container_of(obj->type_attrs, struct uverbs_obj_fd_type, type);
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f = fget(fdno);
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if (!f)
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return ERR_PTR(-EBADF);
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uobject = f->private_data;
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/*
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* fget(id) ensures we are not currently running uverbs_close_fd,
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* and the caller is expected to ensure that uverbs_close_fd is never
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* done while a call top lookup is possible.
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*/
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if (f->f_op != fd_type->fops) {
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fput(f);
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return ERR_PTR(-EBADF);
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}
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uverbs_uobject_get(uobject);
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return uobject;
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}
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struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_api_object *obj,
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struct ib_uverbs_file *ufile, s64 id,
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enum rdma_lookup_mode mode)
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{
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struct ib_uobject *uobj;
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int ret;
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if (!obj)
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return ERR_PTR(-EINVAL);
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uobj = obj->type_class->lookup_get(obj, ufile, id, mode);
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if (IS_ERR(uobj))
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return uobj;
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if (uobj->uapi_object != obj) {
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ret = -EINVAL;
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goto free;
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}
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/*
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* If we have been disassociated block every command except for
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* DESTROY based commands.
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*/
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if (mode != UVERBS_LOOKUP_DESTROY &&
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!srcu_dereference(ufile->device->ib_dev,
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&ufile->device->disassociate_srcu)) {
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ret = -EIO;
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goto free;
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}
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ret = uverbs_try_lock_object(uobj, mode);
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if (ret)
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goto free;
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return uobj;
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free:
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obj->type_class->lookup_put(uobj, mode);
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uverbs_uobject_put(uobj);
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return ERR_PTR(ret);
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}
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static struct ib_uobject *
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alloc_begin_idr_uobject(const struct uverbs_api_object *obj,
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struct ib_uverbs_file *ufile)
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{
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int ret;
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struct ib_uobject *uobj;
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uobj = alloc_uobj(ufile, obj);
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if (IS_ERR(uobj))
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return uobj;
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ret = idr_add_uobj(uobj);
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if (ret)
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goto uobj_put;
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ret = ib_rdmacg_try_charge(&uobj->cg_obj, uobj->context->device,
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RDMACG_RESOURCE_HCA_OBJECT);
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if (ret)
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goto idr_remove;
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return uobj;
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idr_remove:
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spin_lock(&ufile->idr_lock);
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idr_remove(&ufile->idr, uobj->id);
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spin_unlock(&ufile->idr_lock);
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uobj_put:
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uverbs_uobject_put(uobj);
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return ERR_PTR(ret);
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}
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static struct ib_uobject *
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alloc_begin_fd_uobject(const struct uverbs_api_object *obj,
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struct ib_uverbs_file *ufile)
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{
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int new_fd;
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struct ib_uobject *uobj;
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new_fd = get_unused_fd_flags(O_CLOEXEC);
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if (new_fd < 0)
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return ERR_PTR(new_fd);
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uobj = alloc_uobj(ufile, obj);
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if (IS_ERR(uobj)) {
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put_unused_fd(new_fd);
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return uobj;
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}
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uobj->id = new_fd;
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uobj->ufile = ufile;
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return uobj;
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}
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struct ib_uobject *rdma_alloc_begin_uobject(const struct uverbs_api_object *obj,
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struct ib_uverbs_file *ufile)
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{
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struct ib_uobject *ret;
|
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|
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if (!obj)
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return ERR_PTR(-EINVAL);
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|
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/*
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* The hw_destroy_rwsem is held across the entire object creation and
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* released during rdma_alloc_commit_uobject or
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* rdma_alloc_abort_uobject
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*/
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if (!down_read_trylock(&ufile->hw_destroy_rwsem))
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return ERR_PTR(-EIO);
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ret = obj->type_class->alloc_begin(obj, ufile);
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if (IS_ERR(ret)) {
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up_read(&ufile->hw_destroy_rwsem);
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return ret;
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}
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return ret;
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}
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static void alloc_abort_idr_uobject(struct ib_uobject *uobj)
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{
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ib_rdmacg_uncharge(&uobj->cg_obj, uobj->context->device,
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RDMACG_RESOURCE_HCA_OBJECT);
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|
|
|
spin_lock(&uobj->ufile->idr_lock);
|
|
idr_remove(&uobj->ufile->idr, uobj->id);
|
|
spin_unlock(&uobj->ufile->idr_lock);
|
|
}
|
|
|
|
static int __must_check destroy_hw_idr_uobject(struct ib_uobject *uobj,
|
|
enum rdma_remove_reason why)
|
|
{
|
|
const struct uverbs_obj_idr_type *idr_type =
|
|
container_of(uobj->uapi_object->type_attrs,
|
|
struct uverbs_obj_idr_type, type);
|
|
int ret = idr_type->destroy_object(uobj, why);
|
|
|
|
/*
|
|
* We can only fail gracefully if the user requested to destroy the
|
|
* object or when a retry may be called upon an error.
|
|
* In the rest of the cases, just remove whatever you can.
|
|
*/
|
|
if (ib_is_destroy_retryable(ret, why, uobj))
|
|
return ret;
|
|
|
|
if (why == RDMA_REMOVE_ABORT)
|
|
return 0;
|
|
|
|
ib_rdmacg_uncharge(&uobj->cg_obj, uobj->context->device,
|
|
RDMACG_RESOURCE_HCA_OBJECT);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void remove_handle_idr_uobject(struct ib_uobject *uobj)
|
|
{
|
|
spin_lock(&uobj->ufile->idr_lock);
|
|
idr_remove(&uobj->ufile->idr, uobj->id);
|
|
spin_unlock(&uobj->ufile->idr_lock);
|
|
/* Matches the kref in alloc_commit_idr_uobject */
|
|
uverbs_uobject_put(uobj);
|
|
}
|
|
|
|
static void alloc_abort_fd_uobject(struct ib_uobject *uobj)
|
|
{
|
|
put_unused_fd(uobj->id);
|
|
}
|
|
|
|
static int __must_check destroy_hw_fd_uobject(struct ib_uobject *uobj,
|
|
enum rdma_remove_reason why)
|
|
{
|
|
const struct uverbs_obj_fd_type *fd_type = container_of(
|
|
uobj->uapi_object->type_attrs, struct uverbs_obj_fd_type, type);
|
|
int ret = fd_type->context_closed(uobj, why);
|
|
|
|
if (ib_is_destroy_retryable(ret, why, uobj))
|
|
return ret;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void remove_handle_fd_uobject(struct ib_uobject *uobj)
|
|
{
|
|
}
|
|
|
|
static int alloc_commit_idr_uobject(struct ib_uobject *uobj)
|
|
{
|
|
struct ib_uverbs_file *ufile = uobj->ufile;
|
|
|
|
spin_lock(&ufile->idr_lock);
|
|
/*
|
|
* We already allocated this IDR with a NULL object, so
|
|
* this shouldn't fail.
|
|
*
|
|
* NOTE: Once we set the IDR we loose ownership of our kref on uobj.
|
|
* It will be put by remove_commit_idr_uobject()
|
|
*/
|
|
WARN_ON(idr_replace(&ufile->idr, uobj, uobj->id));
|
|
spin_unlock(&ufile->idr_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int alloc_commit_fd_uobject(struct ib_uobject *uobj)
|
|
{
|
|
const struct uverbs_obj_fd_type *fd_type = container_of(
|
|
uobj->uapi_object->type_attrs, struct uverbs_obj_fd_type, type);
|
|
int fd = uobj->id;
|
|
struct file *filp;
|
|
|
|
/*
|
|
* The kref for uobj is moved into filp->private data and put in
|
|
* uverbs_close_fd(). Once alloc_commit() succeeds uverbs_close_fd()
|
|
* must be guaranteed to be called from the provided fops release
|
|
* callback.
|
|
*/
|
|
filp = anon_inode_getfile(fd_type->name,
|
|
fd_type->fops,
|
|
uobj,
|
|
fd_type->flags);
|
|
if (IS_ERR(filp))
|
|
return PTR_ERR(filp);
|
|
|
|
uobj->object = filp;
|
|
|
|
/* Matching put will be done in uverbs_close_fd() */
|
|
kref_get(&uobj->ufile->ref);
|
|
|
|
/* This shouldn't be used anymore. Use the file object instead */
|
|
uobj->id = 0;
|
|
|
|
/*
|
|
* NOTE: Once we install the file we loose ownership of our kref on
|
|
* uobj. It will be put by uverbs_close_fd()
|
|
*/
|
|
fd_install(fd, filp);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* In all cases rdma_alloc_commit_uobject() consumes the kref to uobj and the
|
|
* caller can no longer assume uobj is valid. If this function fails it
|
|
* destroys the uboject, including the attached HW object.
|
|
*/
|
|
int __must_check rdma_alloc_commit_uobject(struct ib_uobject *uobj)
|
|
{
|
|
struct ib_uverbs_file *ufile = uobj->ufile;
|
|
int ret;
|
|
|
|
/* alloc_commit consumes the uobj kref */
|
|
ret = uobj->uapi_object->type_class->alloc_commit(uobj);
|
|
if (ret) {
|
|
uverbs_destroy_uobject(uobj, RDMA_REMOVE_ABORT);
|
|
up_read(&ufile->hw_destroy_rwsem);
|
|
return ret;
|
|
}
|
|
|
|
/* kref is held so long as the uobj is on the uobj list. */
|
|
uverbs_uobject_get(uobj);
|
|
spin_lock_irq(&ufile->uobjects_lock);
|
|
list_add(&uobj->list, &ufile->uobjects);
|
|
spin_unlock_irq(&ufile->uobjects_lock);
|
|
|
|
/* matches atomic_set(-1) in alloc_uobj */
|
|
atomic_set(&uobj->usecnt, 0);
|
|
|
|
/* Matches the down_read in rdma_alloc_begin_uobject */
|
|
up_read(&ufile->hw_destroy_rwsem);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This consumes the kref for uobj. It is up to the caller to unwind the HW
|
|
* object and anything else connected to uobj before calling this.
|
|
*/
|
|
void rdma_alloc_abort_uobject(struct ib_uobject *uobj)
|
|
{
|
|
struct ib_uverbs_file *ufile = uobj->ufile;
|
|
|
|
uobj->object = NULL;
|
|
uverbs_destroy_uobject(uobj, RDMA_REMOVE_ABORT);
|
|
|
|
/* Matches the down_read in rdma_alloc_begin_uobject */
|
|
up_read(&ufile->hw_destroy_rwsem);
|
|
}
|
|
|
|
static void lookup_put_idr_uobject(struct ib_uobject *uobj,
|
|
enum rdma_lookup_mode mode)
|
|
{
|
|
}
|
|
|
|
static void lookup_put_fd_uobject(struct ib_uobject *uobj,
|
|
enum rdma_lookup_mode mode)
|
|
{
|
|
struct file *filp = uobj->object;
|
|
|
|
WARN_ON(mode != UVERBS_LOOKUP_READ);
|
|
/* This indirectly calls uverbs_close_fd and free the object */
|
|
fput(filp);
|
|
}
|
|
|
|
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
|
|
* uverbs_try_lock_object for locking schema information.
|
|
*/
|
|
switch (mode) {
|
|
case UVERBS_LOOKUP_READ:
|
|
atomic_dec(&uobj->usecnt);
|
|
break;
|
|
case UVERBS_LOOKUP_WRITE:
|
|
atomic_set(&uobj->usecnt, 0);
|
|
break;
|
|
case UVERBS_LOOKUP_DESTROY:
|
|
break;
|
|
}
|
|
|
|
/* Pairs with the kref obtained by type->lookup_get */
|
|
uverbs_uobject_put(uobj);
|
|
}
|
|
|
|
void setup_ufile_idr_uobject(struct ib_uverbs_file *ufile)
|
|
{
|
|
spin_lock_init(&ufile->idr_lock);
|
|
idr_init(&ufile->idr);
|
|
}
|
|
|
|
void release_ufile_idr_uobject(struct ib_uverbs_file *ufile)
|
|
{
|
|
struct ib_uobject *entry;
|
|
int id;
|
|
|
|
/*
|
|
* At this point uverbs_cleanup_ufile() is guaranteed to have run, and
|
|
* there are no HW objects left, however the IDR is still populated
|
|
* with anything that has not been cleaned up by userspace. Since the
|
|
* kref on ufile is 0, nothing is allowed to call lookup_get.
|
|
*
|
|
* This is an optimized equivalent to remove_handle_idr_uobject
|
|
*/
|
|
idr_for_each_entry(&ufile->idr, entry, id) {
|
|
WARN_ON(entry->object);
|
|
uverbs_uobject_put(entry);
|
|
}
|
|
|
|
idr_destroy(&ufile->idr);
|
|
}
|
|
|
|
const struct uverbs_obj_type_class uverbs_idr_class = {
|
|
.alloc_begin = alloc_begin_idr_uobject,
|
|
.lookup_get = lookup_get_idr_uobject,
|
|
.alloc_commit = alloc_commit_idr_uobject,
|
|
.alloc_abort = alloc_abort_idr_uobject,
|
|
.lookup_put = lookup_put_idr_uobject,
|
|
.destroy_hw = destroy_hw_idr_uobject,
|
|
.remove_handle = remove_handle_idr_uobject,
|
|
/*
|
|
* When we destroy an object, we first just lock it for WRITE and
|
|
* actually DESTROY it in the finalize stage. So, the problematic
|
|
* scenario is when we just started the finalize stage of the
|
|
* destruction (nothing was executed yet). Now, the other thread
|
|
* fetched the object for READ access, but it didn't lock it yet.
|
|
* The DESTROY thread continues and starts destroying the object.
|
|
* When the other thread continue - without the RCU, it would
|
|
* access freed memory. However, the rcu_read_lock delays the free
|
|
* until the rcu_read_lock of the READ operation quits. Since the
|
|
* exclusive lock of the object is still taken by the DESTROY flow, the
|
|
* READ operation will get -EBUSY and it'll just bail out.
|
|
*/
|
|
.needs_kfree_rcu = true,
|
|
};
|
|
EXPORT_SYMBOL(uverbs_idr_class);
|
|
|
|
void uverbs_close_fd(struct file *f)
|
|
{
|
|
struct ib_uobject *uobj = f->private_data;
|
|
struct ib_uverbs_file *ufile = uobj->ufile;
|
|
|
|
if (down_read_trylock(&ufile->hw_destroy_rwsem)) {
|
|
/*
|
|
* lookup_get_fd_uobject holds the kref on the struct file any
|
|
* time a FD uobj is locked, which prevents this release
|
|
* method from being invoked. Meaning we can always get the
|
|
* write lock here, or we have a kernel bug.
|
|
*/
|
|
WARN_ON(uverbs_try_lock_object(uobj, UVERBS_LOOKUP_WRITE));
|
|
uverbs_destroy_uobject(uobj, RDMA_REMOVE_CLOSE);
|
|
up_read(&ufile->hw_destroy_rwsem);
|
|
}
|
|
|
|
/* Matches the get in alloc_begin_fd_uobject */
|
|
kref_put(&ufile->ref, ib_uverbs_release_file);
|
|
|
|
/* Pairs with filp->private_data in alloc_begin_fd_uobject */
|
|
uverbs_uobject_put(uobj);
|
|
}
|
|
|
|
/*
|
|
* Drop the ucontext off the ufile and completely disconnect it from the
|
|
* ib_device
|
|
*/
|
|
static void ufile_destroy_ucontext(struct ib_uverbs_file *ufile,
|
|
enum rdma_remove_reason reason)
|
|
{
|
|
struct ib_ucontext *ucontext = ufile->ucontext;
|
|
struct ib_device *ib_dev = ucontext->device;
|
|
int ret;
|
|
|
|
/*
|
|
* If we are closing the FD then the user mmap VMAs must have
|
|
* already been destroyed as they hold on to the filep, otherwise
|
|
* they need to be zap'd.
|
|
*/
|
|
if (reason == RDMA_REMOVE_DRIVER_REMOVE) {
|
|
uverbs_user_mmap_disassociate(ufile);
|
|
if (ib_dev->disassociate_ucontext)
|
|
ib_dev->disassociate_ucontext(ucontext);
|
|
}
|
|
|
|
ib_rdmacg_uncharge(&ucontext->cg_obj, ib_dev,
|
|
RDMACG_RESOURCE_HCA_HANDLE);
|
|
|
|
/*
|
|
* FIXME: Drivers are not permitted to fail dealloc_ucontext, remove
|
|
* the error return.
|
|
*/
|
|
ret = ib_dev->dealloc_ucontext(ucontext);
|
|
WARN_ON(ret);
|
|
|
|
ufile->ucontext = NULL;
|
|
}
|
|
|
|
static int __uverbs_cleanup_ufile(struct ib_uverbs_file *ufile,
|
|
enum rdma_remove_reason reason)
|
|
{
|
|
struct ib_uobject *obj, *next_obj;
|
|
int ret = -EINVAL;
|
|
|
|
/*
|
|
* This shouldn't run while executing other commands on this
|
|
* context. Thus, the only thing we should take care of is
|
|
* releasing a FD while traversing this list. The FD could be
|
|
* closed and released from the _release fop of this FD.
|
|
* In order to mitigate this, we add a lock.
|
|
* We take and release the lock per traversal in order to let
|
|
* other threads (which might still use the FDs) chance to run.
|
|
*/
|
|
list_for_each_entry_safe(obj, next_obj, &ufile->uobjects, list) {
|
|
/*
|
|
* if we hit this WARN_ON, that means we are
|
|
* racing with a lookup_get.
|
|
*/
|
|
WARN_ON(uverbs_try_lock_object(obj, UVERBS_LOOKUP_WRITE));
|
|
if (!uverbs_destroy_uobject(obj, reason))
|
|
ret = 0;
|
|
else
|
|
atomic_set(&obj->usecnt, 0);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Destroy the uncontext and every uobject associated with it. If called with
|
|
* reason != RDMA_REMOVE_CLOSE this will not return until the destruction has
|
|
* been completed and ufile->ucontext is NULL.
|
|
*
|
|
* This is internally locked and can be called in parallel from multiple
|
|
* contexts.
|
|
*/
|
|
void uverbs_destroy_ufile_hw(struct ib_uverbs_file *ufile,
|
|
enum rdma_remove_reason reason)
|
|
{
|
|
if (reason == RDMA_REMOVE_CLOSE) {
|
|
/*
|
|
* During destruction we might trigger something that
|
|
* synchronously calls release on any file descriptor. For
|
|
* this reason all paths that come from file_operations
|
|
* release must use try_lock. They can progress knowing that
|
|
* there is an ongoing uverbs_destroy_ufile_hw that will clean
|
|
* up the driver resources.
|
|
*/
|
|
if (!mutex_trylock(&ufile->ucontext_lock))
|
|
return;
|
|
|
|
} else {
|
|
mutex_lock(&ufile->ucontext_lock);
|
|
}
|
|
|
|
down_write(&ufile->hw_destroy_rwsem);
|
|
|
|
/*
|
|
* If a ucontext was never created then we can't have any uobjects to
|
|
* cleanup, nothing to do.
|
|
*/
|
|
if (!ufile->ucontext)
|
|
goto done;
|
|
|
|
ufile->ucontext->closing = true;
|
|
ufile->ucontext->cleanup_retryable = true;
|
|
while (!list_empty(&ufile->uobjects))
|
|
if (__uverbs_cleanup_ufile(ufile, reason)) {
|
|
/*
|
|
* No entry was cleaned-up successfully during this
|
|
* iteration
|
|
*/
|
|
break;
|
|
}
|
|
|
|
ufile->ucontext->cleanup_retryable = false;
|
|
if (!list_empty(&ufile->uobjects))
|
|
__uverbs_cleanup_ufile(ufile, reason);
|
|
|
|
ufile_destroy_ucontext(ufile, reason);
|
|
|
|
done:
|
|
up_write(&ufile->hw_destroy_rwsem);
|
|
mutex_unlock(&ufile->ucontext_lock);
|
|
}
|
|
|
|
const struct uverbs_obj_type_class uverbs_fd_class = {
|
|
.alloc_begin = alloc_begin_fd_uobject,
|
|
.lookup_get = lookup_get_fd_uobject,
|
|
.alloc_commit = alloc_commit_fd_uobject,
|
|
.alloc_abort = alloc_abort_fd_uobject,
|
|
.lookup_put = lookup_put_fd_uobject,
|
|
.destroy_hw = destroy_hw_fd_uobject,
|
|
.remove_handle = remove_handle_fd_uobject,
|
|
.needs_kfree_rcu = false,
|
|
};
|
|
EXPORT_SYMBOL(uverbs_fd_class);
|
|
|
|
struct ib_uobject *
|
|
uverbs_get_uobject_from_file(u16 object_id,
|
|
struct ib_uverbs_file *ufile,
|
|
enum uverbs_obj_access access, s64 id)
|
|
{
|
|
const struct uverbs_api_object *obj =
|
|
uapi_get_object(ufile->device->uapi, object_id);
|
|
|
|
switch (access) {
|
|
case UVERBS_ACCESS_READ:
|
|
return rdma_lookup_get_uobject(obj, ufile, id,
|
|
UVERBS_LOOKUP_READ);
|
|
case UVERBS_ACCESS_DESTROY:
|
|
/* Actual destruction is done inside uverbs_handle_method */
|
|
return rdma_lookup_get_uobject(obj, ufile, id,
|
|
UVERBS_LOOKUP_DESTROY);
|
|
case UVERBS_ACCESS_WRITE:
|
|
return rdma_lookup_get_uobject(obj, ufile, id,
|
|
UVERBS_LOOKUP_WRITE);
|
|
case UVERBS_ACCESS_NEW:
|
|
return rdma_alloc_begin_uobject(obj, ufile);
|
|
default:
|
|
WARN_ON(true);
|
|
return ERR_PTR(-EOPNOTSUPP);
|
|
}
|
|
}
|
|
|
|
int uverbs_finalize_object(struct ib_uobject *uobj,
|
|
enum uverbs_obj_access access,
|
|
bool commit)
|
|
{
|
|
int ret = 0;
|
|
|
|
/*
|
|
* refcounts should be handled at the object level and not at the
|
|
* uobject level. Refcounts of the objects themselves are done in
|
|
* handlers.
|
|
*/
|
|
|
|
switch (access) {
|
|
case UVERBS_ACCESS_READ:
|
|
rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_READ);
|
|
break;
|
|
case UVERBS_ACCESS_WRITE:
|
|
rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_WRITE);
|
|
break;
|
|
case UVERBS_ACCESS_DESTROY:
|
|
if (uobj)
|
|
rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_DESTROY);
|
|
break;
|
|
case UVERBS_ACCESS_NEW:
|
|
if (commit)
|
|
ret = rdma_alloc_commit_uobject(uobj);
|
|
else
|
|
rdma_alloc_abort_uobject(uobj);
|
|
break;
|
|
default:
|
|
WARN_ON(true);
|
|
ret = -EOPNOTSUPP;
|
|
}
|
|
|
|
return ret;
|
|
}
|