Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

[GitHub/LineageOS/android_kernel_samsung_universal7580.git] / mm / filemap.c

diff --git a/mm/filemap.c b/mm/filemap.c
index dd51c68e2b868adbb403b5967c4e7c6be357e722..6c84e598b4a9f7a0c2901387f32307c4e96ebaae 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -58,7 +58,7 @@
 /*
  * Lock ordering:
  *
- *  ->i_mmap_lock              (vmtruncate)
+ *  ->i_mmap_lock              (truncate_pagecache)
  *    ->private_lock           (__free_pte->__set_page_dirty_buffers)
  *      ->swap_lock            (exclusive_swap_page, others)
  *        ->mapping->tree_lock
@@ -104,6 +104,10 @@
  *
  *  ->task->proc_lock
  *    ->dcache_lock            (proc_pid_lookup)
+ *
+ *  (code doesn't rely on that order, so you could switch it around)
+ *  ->tasklist_lock             (memory_failure, collect_procs_ao)
+ *    ->i_mmap_lock
  */
 
 /*
@@ -119,6 +123,8 @@ void __remove_from_page_cache(struct page *page)
        page->mapping = NULL;
        mapping->nrpages--;
        __dec_zone_page_state(page, NR_FILE_PAGES);
+       if (PageSwapBacked(page))
+               __dec_zone_page_state(page, NR_SHMEM);
        BUG_ON(page_mapped(page));
 
        /*
@@ -431,6 +437,8 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
                if (likely(!error)) {
                        mapping->nrpages++;
                        __inc_zone_page_state(page, NR_FILE_PAGES);
+                       if (PageSwapBacked(page))
+                               __inc_zone_page_state(page, NR_SHMEM);
                        spin_unlock_irq(&mapping->tree_lock);
                } else {
                        page->mapping = NULL;