From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751345AbdAQLRA (ORCPT ); Tue, 17 Jan 2017 06:17:00 -0500 Received: from lelnx193.ext.ti.com ([198.47.27.77]:26356 "EHLO lelnx193.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750919AbdAQLQ7 (ORCPT ); Tue, 17 Jan 2017 06:16:59 -0500 From: Lokesh Vutla To: CC: , Linux ARM Mailing List , Tero Kristo , Sekhar Nori , Nishanth Menon , Lokesh Vutla Subject: [RFC PATCH] initramfs: finish fput() before accessing any binary from initramfs Date: Tue, 17 Jan 2017 16:44:56 +0530 Message-ID: <20170117111456.2269-1-lokeshvutla@ti.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org commit 4a9d4b024a31 ("switch fput to task_work_add") implements a schedule_work() for completing fput(), but did not guarantee calling __fput() after unpacking initramfs. Because of this, there is a possibility that during boot a driver can see ETXTBSY when it tries to load a binary from initramfs as fput() is still pending on that binary. This patch makes sure that fput() is completed after unpacking initramfs. Signed-off-by: Lokesh Vutla --- - Reproduced on TI K2HK EVM. K2HK Queue Manager subsystem driver[1] tries to load a firmware from initramfs during boot. Sometimes loading of this firmware fails with error ETXTBSY. Digging a bit more observed that deny_write_access() is returning ETXTBSY as inode->i_writecount is > 0 for that file. This is because Unpacking initramfs does a get_write_access(from open) but hasn't done put_write_access(from fput) as it hasn't been scheduled yet. [1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/soc/ti/knav_qmss_queue.c init/initramfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/init/initramfs.c b/init/initramfs.c index b32ad7d97ac9..c42c69b48a4b 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -18,6 +18,7 @@ #include #include #include +#include static ssize_t __init xwrite(int fd, const char *p, size_t count) { @@ -652,6 +653,7 @@ static int __init populate_rootfs(void) * us a chance to load before device_initcalls. */ load_default_modules(); + flush_delayed_fput(); } return 0; } -- 2.11.0