7 files changed, 30 insertions, 31 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index feb8448d8618..2ed8b0389c51 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -109,7 +109,7 @@
 /*
  * Remove a page from the page cache and free it. Caller has to make
  * sure the page is locked and that nobody else uses it - or that usage
- * is safe.  The caller must hold a write_lock on the mapping's tree_lock.
+ * is safe.  The caller must hold the mapping's tree_lock.
  */
 void __remove_from_page_cache(struct page *page)
 {
@@ -141,9 +141,9 @@ void remove_from_page_cache(struct page *page)
 
         BUG_ON(!PageLocked(page));
 
-        write_lock_irq(&mapping->tree_lock);
+        spin_lock_irq(&mapping->tree_lock);
         __remove_from_page_cache(page);
-        write_unlock_irq(&mapping->tree_lock);
+        spin_unlock_irq(&mapping->tree_lock);
 }
 
 static int sync_page(void *word)
@@ -469,7 +469,7 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
                 page->mapping = mapping;
                 page->index = offset;
 
-                write_lock_irq(&mapping->tree_lock);
+                spin_lock_irq(&mapping->tree_lock);
                 error = radix_tree_insert(&mapping->page_tree, offset, page);
                 if (likely(!error)) {
                         mapping->nrpages++;
@@ -480,7 +480,7 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
                         page_cache_release(page);
                 }
 
-                write_unlock_irq(&mapping->tree_lock);
+                spin_unlock_irq(&mapping->tree_lock);
                 radix_tree_preload_end();
         } else
                 mem_cgroup_uncharge_cache_page(page);
diff --git a/mm/migrate.c b/mm/migrate.c
index 3ca6392e82cc..153572fb60b8 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -323,7 +323,7 @@ static int migrate_page_move_mapping(struct address_space *mapping,
                 return 0;
         }
 
-        write_lock_irq(&mapping->tree_lock);
+        spin_lock_irq(&mapping->tree_lock);
 
         pslot = radix_tree_lookup_slot(&mapping->page_tree,
                                         page_index(page));
@@ -331,12 +331,12 @@ static int migrate_page_move_mapping(struct address_space *mapping,
         expected_count = 2 + !!PagePrivate(page);
         if (page_count(page) != expected_count ||
                         (struct page *)radix_tree_deref_slot(pslot) != page) {
-                write_unlock_irq(&mapping->tree_lock);
+                spin_unlock_irq(&mapping->tree_lock);
                 return -EAGAIN;
         }
 
         if (!page_freeze_refs(page, expected_count)) {
-                write_unlock_irq(&mapping->tree_lock);
+                spin_unlock_irq(&mapping->tree_lock);
                 return -EAGAIN;
         }
 
@@ -373,10 +373,9 @@ static int migrate_page_move_mapping(struct address_space *mapping,
         __dec_zone_page_state(page, NR_FILE_PAGES);
         __inc_zone_page_state(newpage, NR_FILE_PAGES);
 
-        write_unlock_irq(&mapping->tree_lock);
-        if (!PageSwapCache(newpage)) {
+        spin_unlock_irq(&mapping->tree_lock);
+        if (!PageSwapCache(newpage))
                 mem_cgroup_uncharge_cache_page(page);
-        }
 
         return 0;
 }
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 94c6d8988ab3..24de8b65fdbd 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1088,7 +1088,7 @@ int __set_page_dirty_nobuffers(struct page *page)
                 if (!mapping)
                         return 1;
 
-                write_lock_irq(&mapping->tree_lock);
+                spin_lock_irq(&mapping->tree_lock);
                 mapping2 = page_mapping(page);
                 if (mapping2) { /* Race with truncate? */
                         BUG_ON(mapping2 != mapping);
@@ -1102,7 +1102,7 @@ int __set_page_dirty_nobuffers(struct page *page)
                         radix_tree_tag_set(&mapping->page_tree,
                                 page_index(page), PAGECACHE_TAG_DIRTY);
                 }
-                write_unlock_irq(&mapping->tree_lock);
+                spin_unlock_irq(&mapping->tree_lock);
                 if (mapping->host) {
                         /* !PageAnon && !swapper_space */
                         __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
@@ -1258,7 +1258,7 @@ int test_clear_page_writeback(struct page *page)
                 struct backing_dev_info *bdi = mapping->backing_dev_info;
                 unsigned long flags;
 
-                write_lock_irqsave(&mapping->tree_lock, flags);
+                spin_lock_irqsave(&mapping->tree_lock, flags);
                 ret = TestClearPageWriteback(page);
                 if (ret) {
                         radix_tree_tag_clear(&mapping->page_tree,
@@ -1269,7 +1269,7 @@ int test_clear_page_writeback(struct page *page)
                                 __bdi_writeout_inc(bdi);
                         }
                 }
-                write_unlock_irqrestore(&mapping->tree_lock, flags);
+                spin_unlock_irqrestore(&mapping->tree_lock, flags);
         } else {
                 ret = TestClearPageWriteback(page);
         }
@@ -1287,7 +1287,7 @@ int test_set_page_writeback(struct page *page)
                 struct backing_dev_info *bdi = mapping->backing_dev_info;
                 unsigned long flags;
 
-                write_lock_irqsave(&mapping->tree_lock, flags);
+                spin_lock_irqsave(&mapping->tree_lock, flags);
                 ret = TestSetPageWriteback(page);
                 if (!ret) {
                         radix_tree_tag_set(&mapping->page_tree,
@@ -1300,7 +1300,7 @@ int test_set_page_writeback(struct page *page)
                         radix_tree_tag_clear(&mapping->page_tree,
                                                 page_index(page),
                                                 PAGECACHE_TAG_DIRTY);
-                write_unlock_irqrestore(&mapping->tree_lock, flags);
+                spin_unlock_irqrestore(&mapping->tree_lock, flags);
         } else {
                 ret = TestSetPageWriteback(page);
         }
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 3e3381d6c7ee..2c217e33d497 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -39,7 +39,7 @@ static struct backing_dev_info swap_backing_dev_info = {
 
 struct address_space swapper_space = {
         .page_tree      = RADIX_TREE_INIT(GFP_ATOMIC|__GFP_NOWARN),
-        .tree_lock      = __RW_LOCK_UNLOCKED(swapper_space.tree_lock),
+        .tree_lock      = __SPIN_LOCK_UNLOCKED(swapper_space.tree_lock),
         .a_ops          = &swap_aops,
         .i_mmap_nonlinear = LIST_HEAD_INIT(swapper_space.i_mmap_nonlinear),
         .backing_dev_info = &swap_backing_dev_info,
@@ -80,7 +80,7 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
                 SetPageSwapCache(page);
                 set_page_private(page, entry.val);
 
-                write_lock_irq(&swapper_space.tree_lock);
+                spin_lock_irq(&swapper_space.tree_lock);
                 error = radix_tree_insert(&swapper_space.page_tree,
                                                 entry.val, page);
                 if (likely(!error)) {
@@ -88,7 +88,7 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
                         __inc_zone_page_state(page, NR_FILE_PAGES);
                         INC_CACHE_INFO(add_total);
                 }
-                write_unlock_irq(&swapper_space.tree_lock);
+                spin_unlock_irq(&swapper_space.tree_lock);
                 radix_tree_preload_end();
 
                 if (unlikely(error)) {
@@ -182,9 +182,9 @@ void delete_from_swap_cache(struct page *page)
 
         entry.val = page_private(page);
 
-        write_lock_irq(&swapper_space.tree_lock);
+        spin_lock_irq(&swapper_space.tree_lock);
         __delete_from_swap_cache(page);
-        write_unlock_irq(&swapper_space.tree_lock);
+        spin_unlock_irq(&swapper_space.tree_lock);
 
         swap_free(entry);
         page_cache_release(page);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 2f33edb8bee9..af283933c14e 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -369,13 +369,13 @@ int remove_exclusive_swap_page(struct page *page)
         retval = 0;
         if (p->swap_map[swp_offset(entry)] == 1) {
                 /* Recheck the page count with the swapcache lock held.. */
-                write_lock_irq(&swapper_space.tree_lock);
+                spin_lock_irq(&swapper_space.tree_lock);
                 if ((page_count(page) == 2) && !PageWriteback(page)) {
                         __delete_from_swap_cache(page);
                         SetPageDirty(page);
                         retval = 1;
                 }
-                write_unlock_irq(&swapper_space.tree_lock);
+                spin_unlock_irq(&swapper_space.tree_lock);
         }
         spin_unlock(&swap_lock);
 
diff --git a/mm/truncate.c b/mm/truncate.c
index b8961cb63414..e68443d74567 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -349,18 +349,18 @@ invalidate_complete_page2(struct address_space *mapping, struct page *page)
         if (PagePrivate(page) && !try_to_release_page(page, GFP_KERNEL))
                 return 0;
 
-        write_lock_irq(&mapping->tree_lock);
+        spin_lock_irq(&mapping->tree_lock);
         if (PageDirty(page))
                 goto failed;
 
         BUG_ON(PagePrivate(page));
         __remove_from_page_cache(page);
-        write_unlock_irq(&mapping->tree_lock);
+        spin_unlock_irq(&mapping->tree_lock);
         ClearPageUptodate(page);
         page_cache_release(page);       /* pagecache ref */
         return 1;
 failed:
-        write_unlock_irq(&mapping->tree_lock);
+        spin_unlock_irq(&mapping->tree_lock);
         return 0;
 }
 
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 0075eac1cd04..8f71761bc4b7 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -399,7 +399,7 @@ static int __remove_mapping(struct address_space *mapping, struct page *page)
         BUG_ON(!PageLocked(page));
         BUG_ON(mapping != page_mapping(page));
 
-        write_lock_irq(&mapping->tree_lock);
+        spin_lock_irq(&mapping->tree_lock);
         /*
          * The non racy check for a busy page.
          *
@@ -436,17 +436,17 @@ static int __remove_mapping(struct address_space *mapping, struct page *page)
         if (PageSwapCache(page)) {
                 swp_entry_t swap = { .val = page_private(page) };
                 __delete_from_swap_cache(page);
-                write_unlock_irq(&mapping->tree_lock);
+                spin_unlock_irq(&mapping->tree_lock);
                 swap_free(swap);
         } else {
                 __remove_from_page_cache(page);
-                write_unlock_irq(&mapping->tree_lock);
+                spin_unlock_irq(&mapping->tree_lock);
         }
 
         return 1;
 
 cannot_free:
-        write_unlock_irq(&mapping->tree_lock);
+        spin_unlock_irq(&mapping->tree_lock);
         return 0;
 }