io_uring/poll: introduce io_arm_apoll()

In preparation to allowing commands to do file polling, add a helper
that takes the desired poll event mask and arms it for polling. We won't
be able to use io_arm_poll_handler() with IORING_OP_URING_CMD as it
tries to infer the mask from the opcode data, and we can't unify it
across all commands.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7ee5633f2dc45fd15243f1a60965f7e30e1c48e8.1750065793.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/poll.c b/io_uring/poll.c
index 0526062e2f8137a78a4fd8de55cf765b2ddbd03f..c7e9fb34563d0374fbd1e535055c52a50a9552e5 100644 (file)
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -669,33 +669,18 @@ static struct async_poll *io_req_alloc_apoll(struct io_kiocb *req,
        return apoll;
 }
 
-int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags)
+int io_arm_apoll(struct io_kiocb *req, unsigned issue_flags, __poll_t mask)
 {
-       const struct io_issue_def *def = &io_issue_defs[req->opcode];
        struct async_poll *apoll;
        struct io_poll_table ipt;
-       __poll_t mask = POLLPRI | POLLERR | EPOLLET;
        int ret;
 
-       if (!def->pollin && !def->pollout)
-               return IO_APOLL_ABORTED;
+       mask |= EPOLLET;
        if (!io_file_can_poll(req))
                return IO_APOLL_ABORTED;
        if (!(req->flags & REQ_F_APOLL_MULTISHOT))
                mask |= EPOLLONESHOT;
 
-       if (def->pollin) {
-               mask |= EPOLLIN | EPOLLRDNORM;
-
-               /* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */
-               if (req->flags & REQ_F_CLEAR_POLLIN)
-                       mask &= ~EPOLLIN;
-       } else {
-               mask |= EPOLLOUT | EPOLLWRNORM;
-       }
-       if (def->poll_exclusive)
-               mask |= EPOLLEXCLUSIVE;
-
        apoll = io_req_alloc_apoll(req, issue_flags);
        if (!apoll)
                return IO_APOLL_ABORTED;
@@ -712,6 +697,31 @@ int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags)
        return IO_APOLL_OK;
 }
 
+int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags)
+{
+       const struct io_issue_def *def = &io_issue_defs[req->opcode];
+       __poll_t mask = POLLPRI | POLLERR;
+
+       if (!def->pollin && !def->pollout)
+               return IO_APOLL_ABORTED;
+       if (!io_file_can_poll(req))
+               return IO_APOLL_ABORTED;
+
+       if (def->pollin) {
+               mask |= EPOLLIN | EPOLLRDNORM;
+
+               /* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */
+               if (req->flags & REQ_F_CLEAR_POLLIN)
+                       mask &= ~EPOLLIN;
+       } else {
+               mask |= EPOLLOUT | EPOLLWRNORM;
+       }
+       if (def->poll_exclusive)
+               mask |= EPOLLEXCLUSIVE;
+
+       return io_arm_apoll(req, issue_flags, mask);
+}
+
 /*
  * Returns true if we found and killed one or more poll requests
  */

diff --git a/io_uring/poll.h b/io_uring/poll.h
index 27e2db2ed4aee52b972202074377b68fbde868c3..c8438286dfa0a02d8f73208c0d29a327ac4f8279 100644 (file)
--- a/io_uring/poll.h
+++ b/io_uring/poll.h
@@ -41,6 +41,7 @@ int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags);
 struct io_cancel_data;
 int io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd,
                   unsigned issue_flags);
+int io_arm_apoll(struct io_kiocb *req, unsigned issue_flags, __poll_t mask);
 int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags);
 bool io_poll_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx,
                        bool cancel_all);