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RDMA/uverbs: Do not discard the IB_EVENT_DEVICE_FATAL event

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The commit below moved all of the destruction to the disassociate step and
cleaned up the event channel during destroy_uobj.

However, when ib_uverbs_free_hw_resources() pushes IB_EVENT_DEVICE_FATAL
and then immediately goes to destroy all uobjects this causes
ib_uverbs_free_event_queue() to discard the queued event if userspace
hasn't already read() it.

Unlike all other event queues async FD needs to defer the
ib_uverbs_free_event_queue() until FD release. This still unregisters the
handler from the IB device during disassociation.

Fixes: 3e032c0e92aa ("RDMA/core: Make ib_uverbs_async_event_file into a uobject")
Link: https://lore.kernel.org/r/20200507063348.98713-2-leon@kernel.org
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Jason Gunthorpe 2020-05-07 09:33:47 +03:00
parent c8b1f340e5
commit c485b19d52
4 changed files with 29 additions and 3 deletions
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3
drivers/infiniband/core/rdma_core.c
View File

@ -459,7 +459,8 @@ alloc_begin_fd_uobject(const struct uverbs_api_object *obj,
struct ib_uobject *uobj;
struct file *filp;
if (WARN_ON(fd_type->fops->release != &uverbs_uobject_fd_release))
if (WARN_ON(fd_type->fops->release != &uverbs_uobject_fd_release &&
fd_type->fops->release != &uverbs_async_event_release))
return ERR_PTR(-EINVAL);
new_fd = get_unused_fd_flags(O_CLOEXEC);

1
drivers/infiniband/core/uverbs.h
View File

@ -219,6 +219,7 @@ void ib_uverbs_init_event_queue(struct ib_uverbs_event_queue *ev_queue);
void ib_uverbs_init_async_event_file(struct ib_uverbs_async_event_file *ev_file);
void ib_uverbs_free_event_queue(struct ib_uverbs_event_queue *event_queue);
void ib_uverbs_flow_resources_free(struct ib_uflow_resources *uflow_res);
int uverbs_async_event_release(struct inode *inode, struct file *filp);
int ib_alloc_ucontext(struct uverbs_attr_bundle *attrs);
int ib_init_ucontext(struct uverbs_attr_bundle *attrs);

2
drivers/infiniband/core/uverbs_main.c
View File

@ -346,7 +346,7 @@ const struct file_operations uverbs_async_event_fops = {
.owner = THIS_MODULE,
.read = ib_uverbs_async_event_read,
.poll = ib_uverbs_async_event_poll,
.release = uverbs_uobject_fd_release,
.release = uverbs_async_event_release,
.fasync = ib_uverbs_async_event_fasync,
.llseek = no_llseek,
};

26
drivers/infiniband/core/uverbs_std_types_async_fd.c
View File

@ -26,10 +26,34 @@ static int uverbs_async_event_destroy_uobj(struct ib_uobject *uobj,
container_of(uobj, struct ib_uverbs_async_event_file, uobj);
ib_unregister_event_handler(&event_file->event_handler);
ib_uverbs_free_event_queue(&event_file->ev_queue);
return 0;
}
int uverbs_async_event_release(struct inode *inode, struct file *filp)
{
struct ib_uverbs_async_event_file *event_file;
struct ib_uobject *uobj = filp->private_data;
int ret;
if (!uobj)
return uverbs_uobject_fd_release(inode, filp);
event_file =
container_of(uobj, struct ib_uverbs_async_event_file, uobj);
/*
* The async event FD has to deliver IB_EVENT_DEVICE_FATAL even after
* disassociation, so cleaning the event list must only happen after
* release. The user knows it has reached the end of the event stream
* when it sees IB_EVENT_DEVICE_FATAL.
*/
uverbs_uobject_get(uobj);
ret = uverbs_uobject_fd_release(inode, filp);
ib_uverbs_free_event_queue(&event_file->ev_queue);
uverbs_uobject_put(uobj);
return ret;
}
DECLARE_UVERBS_NAMED_METHOD(
UVERBS_METHOD_ASYNC_EVENT_ALLOC,
UVERBS_ATTR_FD(UVERBS_ATTR_ASYNC_EVENT_ALLOC_FD_HANDLE,