io_uring: honour zeroes as io-wq worker limits

When we pass in zero as an io-wq worker number limit it shouldn't actually change the limits but return the old value, follow that behaviour with deferred limits setup as well. Cc: [email protected] # 5.15 Reported-by: Beld Zhang <[email protected]> Fixes: e139a1e ("io_uring: apply max_workers limit to all future users") Signed-off-by: Pavel Begunkov <[email protected]> Link: https://lore.kernel.org/r/1b222a92f7a78a24b042763805e891a4cdd4b544.1636384034.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <[email protected]>
blogic · Nov 8, 2021 · bad119b · bad119b
1 parent a195778
commit bad119b
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/fs/io_uring.c b/fs/io_uring.c
@@ -10791,7 +10791,9 @@ static __cold int io_register_iowq_max_workers(struct io_ring_ctx *ctx,
 
 	BUILD_BUG_ON(sizeof(new_count) != sizeof(ctx->iowq_limits));
 
-	memcpy(ctx->iowq_limits, new_count, sizeof(new_count));
+	for (i = 0; i < ARRAY_SIZE(new_count); i++)
+		if (new_count[i])
+			ctx->iowq_limits[i] = new_count[i];
 	ctx->iowq_limits_set = true;
 
 	if (tctx && tctx->io_wq) {