Re: [patch 3/5] fs: introduce new truncate sequence

[Nick Piggin <npiggin@suse.de>]

On Mon, Aug 17, 2009 at 08:06:12PM +0200, Christoph Hellwig wrote:
> On Mon, Aug 17, 2009 at 06:41:44PM +0200, Nick Piggin wrote:
> > Just wonder what you think of this for an updated patch. Main changes
> > since last time are changelog changed, more comments, and addition of 
> > simple_setattr and inode_set_attributes. I was going to leave
> > simple_setattr for later, but now I found when converting the simple
> > filesystem ramfs that we basically need it anyway.
> > 
> > inode_set_attributes is also following your suggestion and if we use
> > it then we don't have to do that masking away ATTR_SIZE then calling
> > inode_setattr that you didn't like (and I agree with).
> 
> I like this a lot.  But please change the inode_set_attributes name,
> it's awkward and totally falls out of the scheme.  It defintively should
> be <something>_setattr.  Not sure about what to use for the <something>.
> Maybe just generic_setattr, mirroring generic_getattr?

Yeah I agree the name wasn't so good. I guess generic_setattr is better
yes. I will call it that and we can feel free to change it if there is
a better idea before it is merged into Linus.

 
> Btw, one idea on how to avoid having to touch all the
> begin_write/end_write/direct_IO instances:  What about passing another
> callback to them, in addition to the get_blocks also a trim_blocks
> which we call to trim blocks over i_size.  That would be the old
> ->truncate minus the block_truncate_page.

I guess it doesn't fit into non-block filesystems, but it could just
be `cleanup` or something. But on the other hand, I think it is a
bit filesystem specific (eg. what to do in case of error) and it
isn't much problem to add them to write_begin/end functions.

But this is a good question if any fs developers have a strong
preference one way or the other. I think I will just leave it as is
for now because I have done a few conversions already, but we can
always change it later.