io_uring: fix stopping iopoll'ing too early
Nobody adjusts *nr_events (number of completed requests) before calling
io_iopoll_getevents(), so the passed @min shouldn't be adjusted as well.
Othewise it can return less than initially asked @min without hitting
need_resched().
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 60f1a81c..332008f 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2044,7 +2044,7 @@ static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events,
ret = io_do_iopoll(ctx, nr_events, min);
if (ret < 0)
return ret;
- if (!min || *nr_events >= min)
+ if (*nr_events >= min)
return 0;
}
@@ -2087,8 +2087,6 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events,
*/
mutex_lock(&ctx->uring_lock);
do {
- int tmin = 0;
-
/*
* Don't enter poll loop if we already have events pending.
* If we do, we can potentially be spinning for commands that
@@ -2113,10 +2111,7 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events,
mutex_lock(&ctx->uring_lock);
}
- if (*nr_events < min)
- tmin = min - *nr_events;
-
- ret = io_iopoll_getevents(ctx, nr_events, tmin);
+ ret = io_iopoll_getevents(ctx, nr_events, min);
if (ret <= 0)
break;
ret = 0;