1 files changed, 15 insertions, 45 deletions

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 1245df7141aa..64f950925151 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -113,51 +113,6 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
 extern void remove_from_page_cache(struct page *page);
 extern void __remove_from_page_cache(struct page *page);
 
-extern atomic_t nr_pagecache;
-
-#ifdef CONFIG_SMP
-
-#define PAGECACHE_ACCT_THRESHOLD        max(16, NR_CPUS * 2)
-DECLARE_PER_CPU(long, nr_pagecache_local);
-
-/*
- * pagecache_acct implements approximate accounting for pagecache.
- * vm_enough_memory() do not need high accuracy. Writers will keep
- * an offset in their per-cpu arena and will spill that into the
- * global count whenever the absolute value of the local count
- * exceeds the counter's threshold.
- *
- * MUST be protected from preemption.
- * current protection is mapping->page_lock.
- */
-static inline void pagecache_acct(int count)
-{
-        long *local;
-
-        local = &__get_cpu_var(nr_pagecache_local);
-        *local += count;
-        if (*local > PAGECACHE_ACCT_THRESHOLD || *local < -PAGECACHE_ACCT_THRESHOLD) {
-                atomic_add(*local, &nr_pagecache);
-                *local = 0;
-        }
-}
-
-#else
-
-static inline void pagecache_acct(int count)
-{
-        atomic_add(count, &nr_pagecache);
-}
-#endif
-
-static inline unsigned long get_page_cache_size(void)
-{
-        int ret = atomic_read(&nr_pagecache);
-        if (unlikely(ret < 0))
-                ret = 0;
-        return ret;
-}
-
 /*
  * Return byte-offset into filesystem object for page.
  */
@@ -175,14 +130,29 @@ static inline pgoff_t linear_page_index(struct vm_area_struct *vma,
 }
 
 extern void FASTCALL(__lock_page(struct page *page));
+extern void FASTCALL(__lock_page_nosync(struct page *page));
 extern void FASTCALL(unlock_page(struct page *page));
 
+/*
+ * lock_page may only be called if we have the page's inode pinned.
+ */
 static inline void lock_page(struct page *page)
 {
         might_sleep();
         if (TestSetPageLocked(page))
                 __lock_page(page);
 }
+
+/*
+ * lock_page_nosync should only be used if we can't pin the page's inode.
+ * Doesn't play quite so well with block device plugging.
+ */
+static inline void lock_page_nosync(struct page *page)
+{
+        might_sleep();
+        if (TestSetPageLocked(page))
+                __lock_page_nosync(page);
+}
         
 /*
  * This is exported only for wait_on_page_locked/wait_on_page_writeback.