mmap: handle mlocked pages during map, remap, unmap

Originally by Nick Piggin <npiggin@suse.de>

Remove mlocked pages from the LRU using "unevictable infrastructure"
during mmap(), munmap(), mremap() and truncate().  Try to move back to
normal LRU lists on munmap() when last mlocked mapping removed.  Remove
PageMlocked() status when page truncated from file.

[akpm@linux-foundation.org: cleanup]
[kamezawa.hiroyu@jp.fujitsu.com: fix double unlock_page()]
[kosaki.motohiro@jp.fujitsu.com: split LRU: munlock rework]
[lee.schermerhorn@hp.com: mlock: fix __mlock_vma_pages_range comment block]
[akpm@linux-foundation.org: remove bogus kerneldoc token]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamewzawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/mm/truncate.c b/mm/truncate.c
index e83e4b114ef1..1229211104f8 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -18,6 +18,7 @@
 #include <linux/task_io_accounting_ops.h>
 #include <linux/buffer_head.h>  /* grr. try_to_release_page,
                                    do_invalidatepage */
+#include "internal.h"
 
 
 /**
@@ -103,6 +104,7 @@ truncate_complete_page(struct address_space *mapping, struct page *page)
 
         cancel_dirty_page(page, PAGE_CACHE_SIZE);
 
+        clear_page_mlock(page);
         remove_from_page_cache(page);
         ClearPageMappedToDisk(page);
         page_cache_release(page);       /* pagecache ref */
@@ -127,6 +129,7 @@ invalidate_complete_page(struct address_space *mapping, struct page *page)
         if (PagePrivate(page) && !try_to_release_page(page, 0))
                 return 0;
 
+        clear_page_mlock(page);
         ret = remove_mapping(mapping, page);
 
         return ret;
@@ -352,6 +355,7 @@ invalidate_complete_page2(struct address_space *mapping, struct page *page)
         if (PageDirty(page))
                 goto failed;
 
+        clear_page_mlock(page);
         BUG_ON(PagePrivate(page));
         __remove_from_page_cache(page);
         spin_unlock_irq(&mapping->tree_lock);