FS-Cache: Recruit a page flags for cache management

Recruit a page flag to aid in cache management.  The following extra flag is
defined:

 (1) PG_fscache (PG_private_2)

     The marked page is backed by a local cache and is pinning resources in the
     cache driver.

If PG_fscache is set, then things that checked for PG_private will now also
check for that.  This includes things like truncation and page invalidation.
The function page_has_private() had been added to make the checks for both
PG_private and PG_private_2 at the same time.

Signed-off-by: David Howells <[email protected]>
Acked-by: Steve Dickson <[email protected]>
Acked-by: Trond Myklebust <[email protected]>
Acked-by: Rik van Riel <[email protected]>
Acked-by: Al Viro <[email protected]>
Tested-by: Daire Byrne <[email protected]>
This commit is contained in:
David Howells 2009-04-03 16:42:36 +01:00
commit 266cf658ef
8 changed files with 58 additions and 25 deletions

View file

@ -59,7 +59,8 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
*/
wait_on_page_writeback(page);
if (PagePrivate(page) && !try_to_release_page(page, GFP_KERNEL))
if (page_has_private(page) &&
!try_to_release_page(page, GFP_KERNEL))
goto out_unlock;
/*