Commit eb356e6d authored Apr 06, 2020 by Jason Gunthorpe

RDMA/uverbs: Make the event_queue fds return POLLERR when disassociated

If is_closed is set, and the event list is empty, then read() will return
-EIO without blocking. After setting is_closed in
ib_uverbs_free_event_queue(), we do trigger a wake_up on the poll_wait,
but the fops->poll() function does not check it, so poll will continue to
sleep on an empty list.

Fixes: 14e23bd6 ("RDMA/core: Fix locking in ib_uverbs_event_read")
Link: https://lore.kernel.org/r/0-v1-ace813388969+48859-uverbs_poll_fix%25jgg@mellanox.com


Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

parent cf26deff

drivers/infiniband/core/uverbs_main.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -296,6 +296,8 @@ static __poll_t ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue,
		spin_lock_irq(&ev_queue->lock);
		if (!list_empty(&ev_queue->event_list))
		pollflags = EPOLLIN \| EPOLLRDNORM;
		else if (ev_queue->is_closed)
		pollflags = EPOLLERR;
		spin_unlock_irq(&ev_queue->lock);

		return pollflags;

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