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io_uring: clean up io_poll_check_events return values 

The values returned are a bit confusing, where 0 and 1 have implied
meaning, so add some definitions for them.

Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220630091231.1456789-6-dylany@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Dylan Yudaken 2022-06-30 02:12:24 -07:00 committed by Jens Axboe
parent d4e097dae2
commit 2ba69707d9
1 changed files with 16 additions and 11 deletions
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27
io_uring/poll.c
View File

@ -192,13 +192,18 @@ static void io_poll_remove_entries(struct io_kiocb *req)
rcu_read_unlock();
}
enum {
IOU_POLL_DONE = 0,
IOU_POLL_NO_ACTION = 1,
};
/*
* All poll tw should go through this. Checks for poll events, manages
* references, does rewait, etc.
*
* Returns a negative error on failure. >0 when no action require, which is
* either spurious wakeup or multishot CQE is served. 0 when it's done with
* the request, then the mask is stored in req->cqe.res.
* Returns a negative error on failure. IOU_POLL_NO_ACTION when no action require,
* which is either spurious wakeup or multishot CQE is served.
* IOU_POLL_DONE when it's done with the request, then the mask is stored in req->cqe.res.
*/
static int io_poll_check_events(struct io_kiocb *req, bool *locked)
{
@ -214,10 +219,11 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked)
/* tw handler should be the owner, and so have some references */
if (WARN_ON_ONCE(!(v & IO_POLL_REF_MASK)))
return 0;
return IOU_POLL_DONE;
if (v & IO_POLL_CANCEL_FLAG)
return -ECANCELED;
/* the mask was stashed in __io_poll_execute */
if (!req->cqe.res) {
struct poll_table_struct pt = { ._key = req->apoll_events };
req->cqe.res = vfs_poll(req->file, &pt) & req->apoll_events;
@ -226,7 +232,7 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked)
if ((unlikely(!req->cqe.res)))
continue;
if (req->apoll_events & EPOLLONESHOT)
return 0;
return IOU_POLL_DONE;
/* multishot, just fill a CQE and proceed */
if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
@ -238,7 +244,7 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked)
return -ECANCELED;
} else {
ret = io_poll_issue(req, locked);
if (ret)
if (ret < 0)
return ret;
}
@ -248,7 +254,7 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked)
*/
} while (atomic_sub_return(v & IO_POLL_REF_MASK, &req->poll_refs));
return 1;
return IOU_POLL_NO_ACTION;
}
static void io_poll_task_func(struct io_kiocb *req, bool *locked)
@ -256,12 +262,11 @@ static void io_poll_task_func(struct io_kiocb *req, bool *locked)
int ret;
ret = io_poll_check_events(req, locked);
if (ret > 0)
if (ret == IOU_POLL_NO_ACTION)
return;
if (!ret) {
if (ret == IOU_POLL_DONE) {
struct io_poll *poll = io_kiocb_to_cmd(req);
req->cqe.res = mangle_poll(req->cqe.res & poll->events);
} else {
req->cqe.res = ret;
@ -280,7 +285,7 @@ static void io_apoll_task_func(struct io_kiocb *req, bool *locked)
int ret;
ret = io_poll_check_events(req, locked);
if (ret > 0)
if (ret == IOU_POLL_NO_ACTION)
return;
io_poll_remove_entries(req);