From mboxrd@z Thu Jan 1 00:00:00 1970 From: Artem Bityutskiy Subject: Re: [PATCH] UBIFS: kill BKL Date: Mon, 20 Jul 2009 13:26:11 +0300 Message-ID: <1248085571.6140.11.camel@localhost> References: <1248000922-4065-1-git-send-email-dedekind1@gmail.com> <4A640BBF.10106@nokia.com> Reply-To: dedekind1@gmail.com Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: "linux-fsdevel@vger.kernel.org" , "Bityutskiy Artem (Nokia-D/Helsinki)" To: Adrian Hunter Return-path: Received: from smtp.nokia.com ([192.100.105.134]:36310 "EHLO mgw-mx09.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751499AbZGTK24 (ORCPT ); Mon, 20 Jul 2009 06:28:56 -0400 Received: from esebh105.NOE.Nokia.com (esebh105.ntc.nokia.com [172.21.138.211]) by mgw-mx09.nokia.com (Switch-3.3.3/Switch-3.3.3) with ESMTP id n6KASS6H015121 for ; Mon, 20 Jul 2009 05:28:48 -0500 In-Reply-To: <4A640BBF.10106@nokia.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Mon, 2009-07-20 at 09:16 +0300, Adrian Hunter wrote: > Artem Bityutskiy wrote: > > From: Artem Bityutskiy > > > > The BKL was pushed down from VFS to the file-systems. It used > > to serialize mount/unmount/remount. UBIFS must be safe if several > > file-systems are mounted/unmounted/re-mounted at the same time, > > so kill kick the BKL out of UBIFS. > > > > Signed-off-by: Artem Bityutskiy > > --- > > Looks like protection is always provided by sb->s_umount Not for 2 or more instances of fs mounted/umounted/remounted at the same time, which I meant in my comment. But I've fixed the comment. > Missing {} below, btw. New version is below. >>From 347a38db88429400f0f479dc4d7de2b673999433 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Sun, 19 Jul 2009 13:51:04 +0300 Subject: [PATCH] UBIFS: kill BKL The BKL was pushed down from VFS to the file-systems. It used to serialize mount/unmount/remount and prevented more than one instance of the same file-system from doing mount/umount/remount at the same time. But it is OK for UBIFS and it does not need any additional locking for these cases. Thus, kick the BKL out of UBIFS. Signed-off-by: Artem Bityutskiy --- Changelog: fixed parentheses remove #include fs/ubifs/super.c | 13 +------------ 1 files changed, 1 insertions(+), 12 deletions(-) diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index 26d2e0d..13e7ed4 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -36,7 +36,6 @@ #include #include #include -#include #include "ubifs.h" /* @@ -1726,8 +1725,6 @@ static void ubifs_put_super(struct super_block *sb) ubifs_msg("un-mount UBI device %d, volume %d", c->vi.ubi_num, c->vi.vol_id); - lock_kernel(); - /* * The following asserts are only valid if there has not been a failure * of the media. For example, there will be dirty inodes if we failed @@ -1792,8 +1789,6 @@ static void ubifs_put_super(struct super_block *sb) ubi_close_volume(c->ubi); mutex_unlock(&c->umount_mutex); kfree(c); - - unlock_kernel(); } static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data) @@ -1809,22 +1804,17 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data) return err; } - lock_kernel(); if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) { if (c->ro_media) { ubifs_msg("cannot re-mount due to prior errors"); - unlock_kernel(); return -EROFS; } err = ubifs_remount_rw(c); - if (err) { - unlock_kernel(); + if (err) return err; - } } else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY)) { if (c->ro_media) { ubifs_msg("cannot re-mount due to prior errors"); - unlock_kernel(); return -EROFS; } ubifs_remount_ro(c); @@ -1839,7 +1829,6 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data) } ubifs_assert(c->lst.taken_empty_lebs > 0); - unlock_kernel(); return 0; } -- 1.6.0.6