Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
io_uring/eventfd: open code io_eventfd_grab()
io_eventfd_grab() doesn't help wit understanding the path, it'll be
simpler to keep the helper open coded.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5cb53ce3876c2819db9e8055cf41dca4398521db.1745493845.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
authored by
Pavel Begunkov
and committed by
Jens Axboe
f6da4fee
da01f60f
+10
-30
+10
-30
io_uring/eventfd.c
+10
-30
io_uring/eventfd.c
···
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/*
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* Trigger if eventfd_async isn't set, or if it's set and the caller is
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* an async worker. If ev_fd isn't valid, obviously return false.
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* an async worker.
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*/
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static bool io_eventfd_trigger(struct io_ev_fd *ev_fd)
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{
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if (ev_fd)
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return !ev_fd->eventfd_async || io_wq_current_is_worker();
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return false;
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}
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/*
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* On success, returns with an ev_fd reference grabbed and the RCU read
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* lock held.
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*/
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static struct io_ev_fd *io_eventfd_grab(struct io_ring_ctx *ctx)
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{
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struct io_ev_fd *ev_fd;
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/*
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* rcu_dereference ctx->io_ev_fd once and use it for both for checking
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* and eventfd_signal
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*/
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ev_fd = rcu_dereference(ctx->io_ev_fd);
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/*
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* Check again if ev_fd exists in case an io_eventfd_unregister call
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* completed between the NULL check of ctx->io_ev_fd at the start of
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* the function and rcu_read_lock.
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*/
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if (io_eventfd_trigger(ev_fd) && refcount_inc_not_zero(&ev_fd->refs))
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return ev_fd;
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return NULL;
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return !ev_fd->eventfd_async || io_wq_current_is_worker();
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}
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void io_eventfd_signal(struct io_ring_ctx *ctx, bool cqe_event)
···
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return;
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guard(rcu)();
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ev_fd = io_eventfd_grab(ctx);
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ev_fd = rcu_dereference(ctx->io_ev_fd);
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/*
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* Check again if ev_fd exists in case an io_eventfd_unregister call
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* completed between the NULL check of ctx->io_ev_fd at the start of
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* the function and rcu_read_lock.
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*/
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if (!ev_fd)
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return;
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if (!io_eventfd_trigger(ev_fd) || !refcount_inc_not_zero(&ev_fd->refs))
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return;
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if (cqe_event) {