From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 970A42590 for ; Sun, 22 Jan 2023 15:18:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1DA40C4339B; Sun, 22 Jan 2023 15:18:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1674400681; bh=fMf82nTxzvC5LwUhqZe7z1wzBYFlizwz+OhnKcxxmV8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OmRv39vhelwQHP7MW3sEhZgqKnwr1yiyz2rq9dKcEhB9rUaGigWSuC+BrDy3+/6TW t2BxbRnyuuCjlbqUpQLfDtUloD4E5A/zCDTuSi5zjTdkXVX/pKSCW4VNFn36WC5M5r OaQgXzQctKaw8uaEn+4DwPP42AiYICHAZgbe2704= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dylan Yudaken , Pavel Begunkov , Jens Axboe , Sasha Levin Subject: [PATCH 5.15 039/117] io_uring: update kiocb->ki_pos at execution time Date: Sun, 22 Jan 2023 16:03:49 +0100 Message-Id: <20230122150234.368214381@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230122150232.736358800@linuxfoundation.org> References: <20230122150232.736358800@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Dylan Yudaken commit d34e1e5b396a0dbaa4a29b7138df662cfb9d8e8e upstream. Update kiocb->ki_pos at execution time rather than in io_prep_rw(). io_prep_rw() happens before the job is enqueued to a worker and so the offset might be read multiple times before being executed once. Ensures that the file position in a set of _linked_ SQEs will be only obtained after earlier SQEs have completed, and so will include their incremented file position. Signed-off-by: Dylan Yudaken Reviewed-by: Pavel Begunkov Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- io_uring/io_uring.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 14297add8485..d9396cfaa4f3 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2922,14 +2922,6 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, req->flags |= REQ_F_ISREG; kiocb->ki_pos = READ_ONCE(sqe->off); - if (kiocb->ki_pos == -1) { - if (!(file->f_mode & FMODE_STREAM)) { - req->flags |= REQ_F_CUR_POS; - kiocb->ki_pos = file->f_pos; - } else { - kiocb->ki_pos = 0; - } - } kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp)); kiocb->ki_flags = iocb_flags(kiocb->ki_filp); ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags)); @@ -3011,6 +3003,20 @@ static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) } } +static inline void io_kiocb_update_pos(struct io_kiocb *req) +{ + struct kiocb *kiocb = &req->rw.kiocb; + + if (kiocb->ki_pos == -1) { + if (!(req->file->f_mode & FMODE_STREAM)) { + req->flags |= REQ_F_CUR_POS; + kiocb->ki_pos = req->file->f_pos; + } else { + kiocb->ki_pos = 0; + } + } +} + static void kiocb_done(struct kiocb *kiocb, ssize_t ret, unsigned int issue_flags) { @@ -3566,6 +3572,8 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags) return ret ?: -EAGAIN; } + io_kiocb_update_pos(req); + ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), req->result); if (unlikely(ret)) { kfree(iovec); @@ -3700,6 +3708,8 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags) (req->flags & REQ_F_ISREG)) goto copy_iov; + io_kiocb_update_pos(req); + ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), req->result); if (unlikely(ret)) goto out_free; -- 2.39.0