export remove_from_page_cache() to modules

Issue

Lustre developers requested the upstream commit a52116aba5b3eed0ee41f70b794cc1937acd5cb8 to be considered for RHEL6.2

It will allow them to use remove_from_page_cache() in Lustre, which is apparently a better long-term fix that the workaround we're using now.

commit a52116aba5b3eed0ee41f70b794cc1937acd5cb8
Author: Miklos Szeredi <mszeredi@suse.cz>
Date: Tue May 25 15:06:06 2010 +0200

 mm: export remove_from_page_cache() to modules

 This is needed to enable moving pages into the page cache in fuse with
 splice(..., SPLICE_F_MOVE).

 Signed-off-by: Miklos Szeredi <<a href="mailto:mszeredi@suse.cz" class="make_room_for_kcs">mszeredi@suse.cz</a>>

diff --git a/mm/filemap.c b/mm/filemap.c
index 140ebda..09a91a9 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -151,6 +151,7 @@ void remove_from_page_cache(struct page *page)
spin_unlock_irq(&mapping->tree_lock);
mem_cgroup_uncharge_cache_page(page);
}
+EXPORT_SYMBOL(remove_from_page_cache);

static int sync_page(void *word)
{