Re: [PATCH v7 2/4] xfs: Introduce a helper routine to probe data or hole offset from page cache

[Mark Tinguely <tinguely@xxxxxxx>]

On 08/13/12 08:07, Jeff Liu wrote:
> helper routine to lookup data or hole offset from page cache for unwritten 
> extents.
>
> Signed-off-by: Jie Liu<jeff.liu@xxxxxxxxxx>
>
> ---
>   fs/xfs/xfs_file.c |  213 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>   1 files changed, 213 insertions(+), 0 deletions(-)
> +STATIC bool
> +xfs_find_get_desired_pgoff(
> +       struct inode            *inode,
> +       struct xfs_bmbt_irec    *map,
> +       unsigned int            type,
> +       loff_t                  *offset)
> +{
...

> +               for (i = 0; i<  nr_pages; i++) {
> +                       struct page     *page = pvec.pages[i];
> +                       loff_t          b_offset;
> +
> +                       /*
> +                        * Page index is out of range, searching done.
> +                        * If the current offset is not reaches the end
> +                        * of the specified search range, there should
> +                        * be a hole between them.
> +                        */
> +                       if (page->index>  end) {
Shouldn't this sample of the index also be locked?

> +                               if (type == HOLE_OFF&&  lastoff<  endoff) {
> +                                       *offset = lastoff;
> +                                       found = true;
> +                               }
> +                               goto out;
> +                       }
> +
> +                       lock_page(page);
--Mark.