Re: [Ext2-devel] [RFC 0/13] extents and 48bit ext3

Andrew Morton
2006-06-09T18:02:52Z

On Fri, 9 Jun 2006 09:25:57 -0700 (PDT)
Linus Torvalds <torvalds@osdl.org> wrote:

> (buffer heads! In 2006!)

We should be able to make the vast majority of those go away, btw.

We already have `-o data=writeback,nobh'. That gives us writeback-mode
with no buffer_heads on the pagecache.

On top of that we can implement nobh ordered-mode by adding an inode walk
which calls do_sync_file_range() into the appropriate place in commit.

The tricky part is the inode walk - at present super_block.s_list is a
list_head and it's not trivial to walk that without missing some inodes.

Probably it could be done via a new fs-private dirty-inode list which we
hande carefully, or via a walk of an i_ino-ordered radix-tree, which
doesn't miss things.

I floated this a year or so ago, but no little fishies bit.