Hi,

> This is overdue, sorry. Got a little complicated, and I've been away from
> my filesystem test setup so I didn't want ot send it (lucky, coz I found
> a bug after more substantial testing).
> 
> Anyway, RFC?
  Hmm, maybe one comment/question:

> Index: linux-2.6/fs/buffer.c
> ===================================================================
> --- linux-2.6.orig/fs/buffer.c        2007-10-08 14:09:35.000000000 +1000
> +++ linux-2.6/fs/buffer.c     2007-10-08 16:45:28.000000000 +1000
...

> -/*
> - * Make sure any changes to nobh_commit_write() are reflected in
> - * nobh_truncate_page(), since it doesn't call commit_write().
> - */
> -int nobh_commit_write(struct file *file, struct page *page,
> -             unsigned from, unsigned to)
> +int nobh_write_end(struct file *file, struct address_space *mapping,
> +                     loff_t pos, unsigned len, unsigned copied,
> +                     struct page *page, void *fsdata)
>  {
>       struct inode *inode = page->mapping->host;
> -     loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
> +     struct buffer_head *head = NULL;
> +     struct buffer_head *bh;
>  
> -     if (page_has_buffers(page))
> -             return generic_commit_write(file, page, from, to);
> +     if (!PageMappedToDisk(page)) {
> +             if (unlikely(copied < len) && !page_has_buffers(page))
> +                     attach_nobh_buffers(page, head);
> +             if (page_has_buffers(page))
> +                     return generic_write_end(file, mapping, pos, len, 
> copied, page, fsdata);
> +     }
  So we can have a page with attached buffers but we decide to not call
generic_write_end()...

>       SetPageUptodate(page);
>       set_page_dirty(page);
  And we just set the page dirty but we leave buffers clean. So cannot
subsequent try_to_free_buffers() come, mark page as clean (as buffers
are clean) and discard the data?

                                                                Honza
-- 
Jan Kara <[EMAIL PROTECTED]>
SuSE CR Labs
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