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 ED7112F24 for ; Wed, 12 Apr 2023 08:44:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7653FC433D2; Wed, 12 Apr 2023 08:44:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681289050; bh=lxjy0herTY3nPIjIN7MHtjRmv7Ula2S2rl7YYIm7pzw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oL18eHcfvdjPFkI+2jGfz5xJPEKdDCBhbFddmtVnHl2D4EsrNLOMFxBvpbdW4YsR7 8SAwbDbe5VWz9uce1IkwkhIb3N84pdk2QmiQG5wn7XKtgDKbvAK9QDAEc0o2C2yHnj dPsHtqdfnJx8Ei2gCN20O9IK0DRhxE48FsKFwrao= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Nuno=20S=C3=A1?= , Lars-Peter Clausen , Stable@vger.kernel.org, Jonathan Cameron Subject: [PATCH 6.1 077/164] iio: buffer: make sure O_NONBLOCK is respected Date: Wed, 12 Apr 2023 10:33:19 +0200 Message-Id: <20230412082840.027747830@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230412082836.695875037@linuxfoundation.org> References: <20230412082836.695875037@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: Nuno Sá commit 3da1814184582ed0faf039275a3f02e6f69944ee upstream. For output buffers, there's no guarantee that the buffer won't be full in the first iteration of the loop in which case we would block independently of userspace passing O_NONBLOCK or not. Fix it by always checking the flag before going to sleep. While at it (and as it's a bit related), refactored the loop so that the stop condition is 'written != n', i.e, run the loop until all data has been copied into the IIO buffers. This makes the code a bit simpler. Fixes: 9eeee3b0bf190 ("iio: Add output buffer support") Signed-off-by: Nuno Sá Reviewed-by: Lars-Peter Clausen Link: https://lore.kernel.org/r/20230216101452.591805-3-nuno.sa@analog.com Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/industrialio-buffer.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -203,21 +203,24 @@ static ssize_t iio_buffer_write(struct f break; } + if (filp->f_flags & O_NONBLOCK) { + if (!written) + ret = -EAGAIN; + break; + } + wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); continue; } ret = rb->access->write(rb, n - written, buf + written); - if (ret == 0 && (filp->f_flags & O_NONBLOCK)) - ret = -EAGAIN; + if (ret < 0) + break; - if (ret > 0) { - written += ret; - if (written != n && !(filp->f_flags & O_NONBLOCK)) - continue; - } - } while (ret == 0); + written += ret; + + } while (written != n); remove_wait_queue(&rb->pollq, &wait); return ret < 0 ? ret : written;