io_uring: don't alter iopoll reissue fail ret code

When reissue_prep failed in io_complete_rw_iopoll(), we change return
code to -EIO to prevent io_iopoll_complete() from doing resubmission.
Mark requests with a new flag (i.e. REQ_F_DONT_REISSUE) instead and
retain the original return value.

It also removes io_rw_reissue() from io_iopoll_complete() that will be
used later.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-03-22 01:58:32 +00:00 committed by Jens Axboe
parent 1c98679db9
commit 8c130827f4

View File

@ -696,6 +696,7 @@ enum {
REQ_F_LTIMEOUT_ACTIVE_BIT,
REQ_F_COMPLETE_INLINE_BIT,
REQ_F_REISSUE_BIT,
REQ_F_DONT_REISSUE_BIT,
/* keep async read/write and isreg together and in order */
REQ_F_ASYNC_READ_BIT,
REQ_F_ASYNC_WRITE_BIT,
@ -741,6 +742,8 @@ enum {
REQ_F_COMPLETE_INLINE = BIT(REQ_F_COMPLETE_INLINE_BIT),
/* caller should reissue async */
REQ_F_REISSUE = BIT(REQ_F_REISSUE_BIT),
/* don't attempt request reissue, see io_rw_reissue() */
REQ_F_DONT_REISSUE = BIT(REQ_F_DONT_REISSUE_BIT),
/* supports async reads */
REQ_F_ASYNC_READ = BIT(REQ_F_ASYNC_READ_BIT),
/* supports async writes */
@ -1016,7 +1019,6 @@ static struct fixed_rsrc_ref_node *alloc_fixed_rsrc_ref_node(
struct io_ring_ctx *ctx);
static void io_ring_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);
static bool io_rw_reissue(struct io_kiocb *req);
static void io_cqring_fill_event(struct io_kiocb *req, long res);
static void io_put_req(struct io_kiocb *req);
static void io_put_req_deferred(struct io_kiocb *req, int nr);
@ -2253,10 +2255,12 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
req = list_first_entry(done, struct io_kiocb, inflight_entry);
list_del(&req->inflight_entry);
if (READ_ONCE(req->result) == -EAGAIN) {
if (READ_ONCE(req->result) == -EAGAIN &&
!(req->flags & REQ_F_DONT_REISSUE)) {
req->iopoll_completed = 0;
if (io_rw_reissue(req))
continue;
req_ref_get(req);
io_queue_async_work(req);
continue;
}
if (req->flags & REQ_F_BUFFER_SELECTED)
@ -2471,24 +2475,6 @@ static bool io_rw_should_reissue(struct io_kiocb *req)
}
#endif
static bool io_rw_reissue(struct io_kiocb *req)
{
#ifdef CONFIG_BLOCK
if (!io_rw_should_reissue(req))
return false;
lockdep_assert_held(&req->ctx->uring_lock);
if (io_resubmit_prep(req)) {
req_ref_get(req);
io_queue_async_work(req);
return true;
}
req_set_fail_links(req);
#endif
return false;
}
static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
unsigned int issue_flags)
{
@ -2527,15 +2513,17 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
iov_iter_revert(&rw->iter,
req->result - iov_iter_count(&rw->iter));
else if (!io_resubmit_prep(req))
res = -EIO;
req->flags |= REQ_F_DONT_REISSUE;
}
#endif
if (kiocb->ki_flags & IOCB_WRITE)
kiocb_end_write(req);
if (res != -EAGAIN && res != req->result)
if (res != -EAGAIN && res != req->result) {
req->flags |= REQ_F_DONT_REISSUE;
req_set_fail_links(req);
}
WRITE_ONCE(req->result, res);
/* order with io_iopoll_complete() checking ->result */
@ -2776,7 +2764,10 @@ static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
if (check_reissue && req->flags & REQ_F_REISSUE) {
req->flags &= ~REQ_F_REISSUE;
if (!io_rw_reissue(req)) {
if (!io_resubmit_prep(req)) {
req_ref_get(req);
io_queue_async_work(req);
} else {
int cflags = 0;
req_set_fail_links(req);