Commit a6ba632d authored by Jens Axboe's avatar Jens Axboe

io_uring: retry poll if we got woken with non-matching mask

If we get woken and the poll doesn't match our mask, re-add the task
to the poll waitqueue and try again instead of completing the request
with a mask of 0.
Reported-by: default avatarDan Melnic <dmm@fb.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 10bea96d
...@@ -4412,8 +4412,20 @@ static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error) ...@@ -4412,8 +4412,20 @@ static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error)
static void io_poll_task_handler(struct io_kiocb *req, struct io_kiocb **nxt) static void io_poll_task_handler(struct io_kiocb *req, struct io_kiocb **nxt)
{ {
struct io_ring_ctx *ctx = req->ctx; struct io_ring_ctx *ctx = req->ctx;
struct io_poll_iocb *poll = &req->poll;
if (!req->result && !READ_ONCE(poll->canceled)) {
struct poll_table_struct pt = { ._key = poll->events };
req->result = vfs_poll(req->file, &pt) & poll->events;
}
spin_lock_irq(&ctx->completion_lock); spin_lock_irq(&ctx->completion_lock);
if (!req->result && !READ_ONCE(poll->canceled)) {
add_wait_queue(poll->head, &poll->wait);
spin_unlock_irq(&ctx->completion_lock);
return;
}
hash_del(&req->hash_node); hash_del(&req->hash_node);
io_poll_complete(req, req->result, 0); io_poll_complete(req, req->result, 0);
req->flags |= REQ_F_COMP_LOCKED; req->flags |= REQ_F_COMP_LOCKED;
......
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