From: Alexander Viro <viro@math.psu.edu>
To: Matthew Wilcox <matthew@wil.cx>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Linus Torvalds <torvalds@transmeta.com>
Subject: Re: [Final call for testers][PATCH] superblock handling changes (2.4.6-pre3)
Date: Fri, 15 Jun 2001 12:34:41 -0400 (EDT) [thread overview]
Message-ID: <Pine.GSO.4.21.0106151221190.8909-100000@weyl.math.psu.edu> (raw)
In-Reply-To: <20010615171632.C9522@parcelfarce.linux.theplanet.co.uk>
On Fri, 15 Jun 2001, Matthew Wilcox wrote:
> > + while (sb != sb_entry(&super_blocks))
> > + if (sb->s_dirt) {
> > + sb->s_count++;
^^^^^^^^^^^^^^
> > + spin_unlock(&sb_lock);
> > + down_read(&sb->s_umount);
> > + write_super(sb);
> > + drop_super(sb);
> > + goto restart;
> > + } else
> > + sb = sb_entry(sb->s_list.next);
> > + spin_unlock(&sb_lock);
>
> I think this could be clearer.
>
> struct list_head *tmp;
> restart:
> spin_lock(&sb_lock);
> list_for_each(tmp, super_blocks) {
> struct super_block *sb = sb_entry(tmp);
> if (!sb->s_dirt)
> continue;
> spin_unlock(&sb_lock);
> down_read(&sb->s_umount);
> write_super(sb);
> drop_super(sb);
> goto restart;
> }
> spin_unlock(&sb_lock);
Aside of the missing ->s_count++ - no arguments.
> > @@ -773,16 +810,16 @@
> > void *data, int silent)
> > {
> > struct super_block * s;
> > - s = get_empty_super();
> > + s = alloc_super();
> > if (!s)
> > goto out;
> > s->s_dev = dev;
> > s->s_bdev = bdev;
> > s->s_flags = flags;
> > - s->s_dirt = 0;
> > s->s_type = type;
> > - s->s_dquot.flags = 0;
> > - s->s_maxbytes = MAX_NON_LFS;
> > + spin_lock(&sb_lock);
> > + list_add (&s->s_list, super_blocks.prev);
>
> I'd use list_add_tail(&s->s_list, super_blocks);
Umm... Why? I've no problems with either variant, but I really see no
clear win (or loss) in list_add_tail here. If there is some code that
relies on the order in that list it's badly broken - remember, we used
to reuse unmounted superblocks, so order might be almost arbitrary.
Not even "root is first", whatever value that might have - FS_SINGLE
filesystems ended up before the root.
next prev parent reply other threads:[~2001-06-15 16:35 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-06-12 4:29 [CFT][PATCH] superblock handling changes Alexander Viro
2001-06-12 3:22 ` Marcelo Tosatti
2001-06-12 5:17 ` Alexander Viro
2001-06-12 6:38 ` George Bonser
2001-06-13 4:50 ` [CFT][PATCH] superblock handling changes (2.4.6-pre3) Alexander Viro
2001-06-15 5:10 ` [Final call for testers][PATCH] " Alexander Viro
2001-06-15 16:16 ` Matthew Wilcox
2001-06-15 16:34 ` Alexander Viro [this message]
2001-06-15 16:41 ` Alexander Viro
2001-06-15 16:49 ` Matthew Wilcox
2001-06-15 19:12 ` Linus Torvalds
2001-06-15 19:18 ` Alexander Viro
2001-06-15 17:02 ` Jonathan Lundell
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