aboutsummaryrefslogtreecommitdiff
path: root/io_uring
diff options
context:
space:
mode:
authorPavel Begunkov2022-06-23 14:24:48 +0100
committerJens Axboe2022-07-24 18:39:16 -0600
commitde08356f4858628fdffb8bd7e9cceb60c7e08ead (patch)
tree2a551cecc6e6722107b38d2501b2fbbfd9c397e8 /io_uring
parent063a007996bf725ba4c7d8741701670be9858300 (diff)
io_uring: refactor poll arm error handling
__io_arm_poll_handler() errors parsing is a horror, in case it failed it returns 0 and the caller is expected to look at ipt.error, which already led us to a number of problems before. When it returns a valid mask, leave it as it's not, i.e. return 1 and store the mask in ipt.result_mask. In case of a failure that can be handled inline return an error code (negative value), and return 0 if __io_arm_poll_handler() took ownership of the request and will complete it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/018cacdaef5fe95d7dc56b32e85d752cab7607f6.1655990418.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
-rw-r--r--io_uring/poll.c44
1 files changed, 21 insertions, 23 deletions
diff --git a/io_uring/poll.c b/io_uring/poll.c
index 80113b036c88..3f3ae3b1505f 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -435,6 +435,12 @@ static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head,
(struct io_poll **) &pt->req->async_data);
}
+/*
+ * Returns 0 when it's handed over for polling. The caller owns the requests if
+ * it returns non-zero, but otherwise should not touch it. Negative values
+ * contain an error code. When the result is >0, the polling has completed
+ * inline and ipt.result_mask is set to the mask.
+ */
static int __io_arm_poll_handler(struct io_kiocb *req,
struct io_poll *poll,
struct io_poll_table *ipt, __poll_t mask)
@@ -461,6 +467,17 @@ static int __io_arm_poll_handler(struct io_kiocb *req,
atomic_set(&req->poll_refs, 1);
mask = vfs_poll(req->file, &ipt->pt) & poll->events;
+ if (unlikely(ipt->error || !ipt->nr_entries)) {
+ io_poll_remove_entries(req);
+
+ if (mask && (poll->events & EPOLLET)) {
+ ipt->result_mask = mask;
+ return 1;
+ } else {
+ return ipt->error ?: -EINVAL;
+ }
+ }
+
if (mask &&
((poll->events & (EPOLLET|EPOLLONESHOT)) == (EPOLLET|EPOLLONESHOT))) {
io_poll_remove_entries(req);
@@ -469,25 +486,12 @@ static int __io_arm_poll_handler(struct io_kiocb *req,
return 1;
}
- if (!mask && unlikely(ipt->error || !ipt->nr_entries)) {
- io_poll_remove_entries(req);
- if (!ipt->error)
- ipt->error = -EINVAL;
- return 0;
- }
-
if (req->flags & REQ_F_HASH_LOCKED)
io_poll_req_insert_locked(req);
else
io_poll_req_insert(req);
if (mask && (poll->events & EPOLLET)) {
- /* can't multishot if failed, just queue the event we've got */
- if (unlikely(ipt->error || !ipt->nr_entries)) {
- poll->events |= EPOLLONESHOT;
- req->apoll_events |= EPOLLONESHOT;
- ipt->error = 0;
- }
__io_poll_execute(req, mask);
return 0;
}
@@ -582,9 +586,8 @@ int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags)
io_kbuf_recycle(req, issue_flags);
ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask);
- if (ret || ipt.error)
- return ret ? IO_APOLL_READY : IO_APOLL_ABORTED;
-
+ if (ret)
+ return ret > 0 ? IO_APOLL_READY : IO_APOLL_ABORTED;
trace_io_uring_poll_arm(req, mask, apoll->poll.events);
return IO_APOLL_OK;
}
@@ -815,16 +818,11 @@ int io_poll_add(struct io_kiocb *req, unsigned int issue_flags)
req->flags &= ~REQ_F_HASH_LOCKED;
ret = __io_arm_poll_handler(req, poll, &ipt, poll->events);
- if (ret) {
+ if (ret > 0) {
io_req_set_res(req, ipt.result_mask, 0);
return IOU_OK;
}
- if (ipt.error) {
- req_set_fail(req);
- return ipt.error;
- }
-
- return IOU_ISSUE_SKIP_COMPLETE;
+ return ret ?: IOU_ISSUE_SKIP_COMPLETE;
}
int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags)