[PATCH v2 2/3] io_uring: fix stopping iopoll'ing too early

[Pavel Begunkov <asml.silence@gmail.com>]

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>
---
 fs/io_uring.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 50f9260eea9b..020944a193d0 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2037,7 +2037,7 @@ 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;
 	}
 
@@ -2080,8 +2080,6 @@ 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
@@ -2106,10 +2104,7 @@ 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;
-- 
2.24.0