Merge branch 'master' into upstream

[sfrench/cifs-2.6.git] / include / linux / pagemap.h

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 9539efd4f7e676fc350571cb4cd51c4b9ef9977c..64f95092515120a517ba53c97a606c600a66e40c 100644 (file)
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -78,6 +78,8 @@ extern struct page * find_or_create_page(struct address_space *mapping,
                                unsigned long index, gfp_t gfp_mask);
 unsigned find_get_pages(struct address_space *mapping, pgoff_t start,
                        unsigned int nr_pages, struct page **pages);
+unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start,
+                              unsigned int nr_pages, struct page **pages);
 unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index,
                        int tag, unsigned int nr_pages, struct page **pages);
 
@@ -97,6 +99,13 @@ extern struct page * read_cache_page(struct address_space *mapping,
 extern int read_cache_pages(struct address_space *mapping,
                struct list_head *pages, filler_t *filler, void *data);
 
+static inline struct page *read_mapping_page(struct address_space *mapping,
+                                            unsigned long index, void *data)
+{
+       filler_t *filler = (filler_t *)mapping->a_ops->readpage;
+       return read_cache_page(mapping, index, filler, data);
+}
+
 int add_to_page_cache(struct page *page, struct address_space *mapping,
                                unsigned long index, gfp_t gfp_mask);
 int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
@@ -104,51 +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.
  */
@@ -166,14 +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.