1 files changed, 40 insertions, 15 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index e630188ccc40..488b7088557c 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -23,6 +23,7 @@
 #include <linux/backing-dev.h>
 #include <linux/blkdev.h>
 #include <linux/mpage.h>
+#include <linux/rmap.h>
 #include <linux/percpu.h>
 #include <linux/notifier.h>
 #include <linux/smp.h>
@@ -45,7 +46,6 @@
  */
 static long ratelimit_pages = 32;
 
-static long total_pages;        /* The total number of pages in the machine. */
 static int dirty_exceeded __cacheline_aligned_in_smp;   /* Dirty mem may be over limit */
 
 /*
@@ -125,7 +125,7 @@ get_dirty_limits(long *pbackground, long *pdirty,
         int unmapped_ratio;
         long background;
         long dirty;
-        unsigned long available_memory = total_pages;
+        unsigned long available_memory = vm_total_pages;
         struct task_struct *tsk;
 
 #ifdef CONFIG_HIGHMEM
@@ -140,7 +140,7 @@ get_dirty_limits(long *pbackground, long *pdirty,
 
         unmapped_ratio = 100 - ((global_page_state(NR_FILE_MAPPED) +
                                 global_page_state(NR_ANON_PAGES)) * 100) /
-                                        total_pages;
+                                        vm_total_pages;
 
         dirty_ratio = vm_dirty_ratio;
         if (dirty_ratio > unmapped_ratio / 2)
@@ -243,6 +243,16 @@ static void balance_dirty_pages(struct address_space *mapping)
                 pdflush_operation(background_writeout, 0);
 }
 
+void set_page_dirty_balance(struct page *page)
+{
+        if (set_page_dirty(page)) {
+                struct address_space *mapping = page_mapping(page);
+
+                if (mapping)
+                        balance_dirty_pages_ratelimited(mapping);
+        }
+}
+
 /**
  * balance_dirty_pages_ratelimited_nr - balance dirty memory state
  * @mapping: address_space which was dirtied
@@ -491,9 +501,9 @@ void laptop_sync_completion(void)
  * will write six megabyte chunks, max.
  */
 
-static void set_ratelimit(void)
+void writeback_set_ratelimit(void)
 {
-        ratelimit_pages = total_pages / (num_online_cpus() * 32);
+        ratelimit_pages = vm_total_pages / (num_online_cpus() * 32);
         if (ratelimit_pages < 16)
                 ratelimit_pages = 16;
         if (ratelimit_pages * PAGE_CACHE_SIZE > 4096 * 1024)
@@ -503,7 +513,7 @@ static void set_ratelimit(void)
 static int __cpuinit
 ratelimit_handler(struct notifier_block *self, unsigned long u, void *v)
 {
-        set_ratelimit();
+        writeback_set_ratelimit();
         return 0;
 }
 
@@ -522,9 +532,7 @@ void __init page_writeback_init(void)
         long buffer_pages = nr_free_buffer_pages();
         long correction;
 
-        total_pages = nr_free_pagecache_pages();
-
-        correction = (100 * 4 * buffer_pages) / total_pages;
+        correction = (100 * 4 * buffer_pages) / vm_total_pages;
 
         if (correction < 100) {
                 dirty_background_ratio *= correction;
@@ -538,7 +546,7 @@ void __init page_writeback_init(void)
                         vm_dirty_ratio = 1;
         }
         mod_timer(&wb_timer, jiffies + dirty_writeback_interval);
-        set_ratelimit();
+        writeback_set_ratelimit();
         register_cpu_notifier(&ratelimit_nb);
 }
 
@@ -550,7 +558,7 @@ int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
                 return 0;
         wbc->for_writepages = 1;
         if (mapping->a_ops->writepages)
-                ret =  mapping->a_ops->writepages(mapping, wbc);
+                ret = mapping->a_ops->writepages(mapping, wbc);
         else
                 ret = generic_writepages(mapping, wbc);
         wbc->for_writepages = 0;
@@ -690,7 +698,7 @@ int set_page_dirty_lock(struct page *page)
 {
         int ret;
 
-        lock_page(page);
+        lock_page_nosync(page);
         ret = set_page_dirty(page);
         unlock_page(page);
         return ret;
@@ -712,9 +720,15 @@ int test_clear_page_dirty(struct page *page)
                         radix_tree_tag_clear(&mapping->page_tree,
                                                 page_index(page),
                                                 PAGECACHE_TAG_DIRTY);
-                        if (mapping_cap_account_dirty(mapping))
-                                __dec_zone_page_state(page, NR_FILE_DIRTY);
                         write_unlock_irqrestore(&mapping->tree_lock, flags);
+                        /*
+                         * We can continue to use `mapping' here because the
+                         * page is locked, which pins the address_space
+                         */
+                        if (mapping_cap_account_dirty(mapping)) {
+                                page_mkclean(page);
+                                dec_zone_page_state(page, NR_FILE_DIRTY);
+                        }
                         return 1;
                 }
                 write_unlock_irqrestore(&mapping->tree_lock, flags);
@@ -744,8 +758,10 @@ int clear_page_dirty_for_io(struct page *page)
 
         if (mapping) {
                 if (TestClearPageDirty(page)) {
-                        if (mapping_cap_account_dirty(mapping))
+                        if (mapping_cap_account_dirty(mapping)) {
+                                page_mkclean(page);
                                 dec_zone_page_state(page, NR_FILE_DIRTY);
+                        }
                         return 1;
                 }
                 return 0;
@@ -803,6 +819,15 @@ int test_set_page_writeback(struct page *page)
 EXPORT_SYMBOL(test_set_page_writeback);
 
 /*
+ * Wakes up tasks that are being throttled due to writeback congestion
+ */
+void writeback_congestion_end(void)
+{
+        blk_congestion_end(WRITE);
+}
+EXPORT_SYMBOL(writeback_congestion_end);
+
+/*
  * Return true if any of the pages in the mapping are marged with the
  * passed tag.
  */