mm: truncate: change remove_from_page_cache

mm: truncate: change remove_from_page_cache

This patch series changes remove_from_page_cache()'s page ref counting
rule.  Page cache ref count is decreased in delete_from_page_cache().  So
we don't need to decrease the page reference in callers.

Signed-off-by: Minchan Kim <[email protected]>
Cc: Dan Magenheimer <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: Al Viro <[email protected]>
Acked-by: Hugh Dickins <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Reviewed-by: KAMEZAWA Hiroyuki <[email protected]>
Reviewed-by: Johannes Weiner <[email protected]>
Reviewed-by: KOSAKI Motohiro <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>