From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755780AbbINNtq (ORCPT ); Mon, 14 Sep 2015 09:49:46 -0400 Received: from mail-yk0-f170.google.com ([209.85.160.170]:35408 "EHLO mail-yk0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753868AbbINNqE (ORCPT ); Mon, 14 Sep 2015 09:46:04 -0400 From: Jeff Layton X-Google-Original-From: Jeff Layton To: Al Viro Cc: bfields@fieldses.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/4] fs: add a kerneldoc header to fput Date: Mon, 14 Sep 2015 09:45:53 -0400 Message-Id: <1442238355-8203-3-git-send-email-jeff.layton@primarydata.com> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1442238355-8203-1-git-send-email-jeff.layton@primarydata.com> References: <1442238355-8203-1-git-send-email-jeff.layton@primarydata.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ...and move its EXPORT_SYMBOL just below the function. Signed-off-by: Jeff Layton --- fs/file_table.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/fs/file_table.c b/fs/file_table.c index f4833af62eae..d63f4a399d39 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -260,6 +260,21 @@ void flush_delayed_fput(void) flush_delayed_work(&delayed_fput_work); } +/** + * fput - put a struct file reference + * @file: file of which to put the reference + * + * This function decrements the reference count for the struct file reference, + * and queues it up for destruction if the count goes to zero. In the case of + * most tasks we queue it to the task_work infrastructure, which will be run + * just before the task returns back to userspace. kthreads however never + * return to userspace, so for those we add them to a global list and schedule + * a delayed workqueue job to do the work of putting them. + * + * Why not just do it synchronously? __fput can be quite stack intensive, so + * doing a final fput has the possibility of blowing up if we don't take steps + * to ensure that we have enough stack space to make it work. + */ void fput(struct file *file) { if (atomic_long_dec_and_test(&file->f_count)) { @@ -280,6 +295,7 @@ void fput(struct file *file) schedule_delayed_work(&delayed_fput_work, 1); } } +EXPORT_SYMBOL(fput); /* * synchronous analog of fput(); for kernel threads that might be needed @@ -298,7 +314,6 @@ void __fput_sync(struct file *file) } } -EXPORT_SYMBOL(fput); void put_filp(struct file *file) { -- 2.4.3