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Subject[PATCH v2 for-next 05/12] io_uring: clean up io_poll_check_events return values
Date
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>
---
io_uring/poll.c | 27 ++++++++++++++++-----------
1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/io_uring/poll.c b/io_uring/poll.c
index fa25b88a7b93..922a3d1b2e31 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -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);
--
2.30.2
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