Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756834Ab2FFPzp (ORCPT ); Wed, 6 Jun 2012 11:55:45 -0400 Received: from mga11.intel.com ([192.55.52.93]:47640 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756248Ab2FFPzn (ORCPT ); Wed, 6 Jun 2012 11:55:43 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="161755263" From: Artem Bityutskiy To: Al Viro , Jan Kara Cc: Linux FS Maling List , Linux Kernel Maling List Subject: [PATCH v2 1/7] affs: stop setting bm_flags Date: Wed, 6 Jun 2012 18:56:51 +0300 Message-Id: <1338998217-5010-2-git-send-email-dedekind1@gmail.com> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1338998217-5010-1-git-send-email-dedekind1@gmail.com> References: <1338998217-5010-1-git-send-email-dedekind1@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3250 Lines: 88 From: Artem Bityutskiy AFFS stores values '1' and '2' in 'bm_flags', and I fail to see any logic when it prefers one or another. AFFS writes '1' only from '->put_super()', while '->sync_fs()' and '->write_super()' store value '2'. So on the first glance, it looks like we want to have '1' if we unmount. However, this does not really happen in these cases: 1. superblock is written via 'write_super()' then we unmount; 2. we re-mount R/O, then unmount. which are quite typical. I could not find good documentation describing this field, except of one random piece of documentation in the internet which says that -1 means that the root block is valid, which is not consistent with what we have in the Linux AFFS driver. Jan Kara commented on this: "I have some vague recollection that on Amiga boolean was usually encoded as: 0 == false, ~0 == -1 == true. But it has been ages..." Thus, my conclusion is that value of '1' is as good as value of '2' and we can just always use '2'. An Jan Kara suggested to go further: "generally bm_flags handling looks strange. If they are 0, we mount fs read only and thus cannot change them. If they are != 0, we write 2 there. So IMHO if you just removed bm_flags setting, nothing will really happen." So this patch removes the bm_flags setting completely. This makes the "clean" argument of the 'affs_commit_super()' function unneeded, so it is also removed. Signed-off-by: Artem Bityutskiy --- fs/affs/super.c | 9 ++++----- 1 files changed, 4 insertions(+), 5 deletions(-) diff --git a/fs/affs/super.c b/fs/affs/super.c index 0782653..1d42e46 100644 --- a/fs/affs/super.c +++ b/fs/affs/super.c @@ -25,13 +25,12 @@ static int affs_statfs(struct dentry *dentry, struct kstatfs *buf); static int affs_remount (struct super_block *sb, int *flags, char *data); static void -affs_commit_super(struct super_block *sb, int wait, int clean) +affs_commit_super(struct super_block *sb, int wait) { struct affs_sb_info *sbi = AFFS_SB(sb); struct buffer_head *bh = sbi->s_root_bh; struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh); - tail->bm_flag = cpu_to_be32(clean); secs_to_datestamp(get_seconds(), &tail->disk_change); affs_fix_checksum(sb, bh); mark_buffer_dirty(bh); @@ -46,7 +45,7 @@ affs_put_super(struct super_block *sb) pr_debug("AFFS: put_super()\n"); if (!(sb->s_flags & MS_RDONLY) && sb->s_dirt) - affs_commit_super(sb, 1, 1); + affs_commit_super(sb, 1); kfree(sbi->s_prefix); affs_free_bitmap(sb); @@ -60,7 +59,7 @@ affs_write_super(struct super_block *sb) { lock_super(sb); if (!(sb->s_flags & MS_RDONLY)) - affs_commit_super(sb, 1, 2); + affs_commit_super(sb, 1); sb->s_dirt = 0; unlock_super(sb); @@ -71,7 +70,7 @@ static int affs_sync_fs(struct super_block *sb, int wait) { lock_super(sb); - affs_commit_super(sb, wait, 2); + affs_commit_super(sb, wait); sb->s_dirt = 0; unlock_super(sb); return 0; -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/