From 7a12035aa00fbf1fb92d2717630fee575efcf43b Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Thu, 15 Apr 2021 17:35:45 +0800 Subject: [PATCH] io_uring: clamp to_submit in io_submit_sqes() mainline inclusion from mainline-5.6-rc1 commit 9ef4f124894b7b9241a3cf5f9b40db0812783d66 category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA --------------------------- Make io_submit_sqes() to clamp @to_submit itself. It removes duplicated code and prepares for following changes. Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe Conflicts fs/io_uring.c [conflicts with 73e08e711d9c(Revert "io_uring: only allow submit from owning task")] Signed-off-by: yangerkun Signed-off-by: yangerkun Reviewed-by: zhangyi (F) Signed-off-by: Cheng Jian --- fs/io_uring.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 0853745726db..dccf946d4203 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4574,6 +4574,8 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, return -EBUSY; } + nr = min(nr, ctx->sq_entries); + if (!percpu_ref_tryget_many(&ctx->refs, nr)) return -EAGAIN; @@ -4748,7 +4750,6 @@ static int io_sq_thread(void *data) ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP; } - to_submit = min(to_submit, ctx->sq_entries); mutex_lock(&ctx->uring_lock); ret = io_submit_sqes(ctx, to_submit, NULL, -1, &cur_mm, true); mutex_unlock(&ctx->uring_lock); @@ -6088,7 +6089,6 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, } else if (to_submit) { struct mm_struct *cur_mm; - to_submit = min(to_submit, ctx->sq_entries); mutex_lock(&ctx->uring_lock); /* already have mm, so io_submit_sqes() won't try to grab it */ cur_mm = ctx->sqo_mm; -- GitLab