mm/rmap: share the i_mmap_rwsem

[cascardo/linux.git] / mm / rmap.c

diff --git a/mm/rmap.c b/mm/rmap.c
index 3e4c721..14ad2b3 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -23,7 +23,7 @@
  * inode->i_mutex      (while writing or truncating, not reading or faulting)
  *   mm->mmap_sem
  *     page->flags PG_locked (lock_page)
- *       mapping->i_mmap_mutex
+ *       mapping->i_mmap_rwsem
  *         anon_vma->rwsem
  *           mm->page_table_lock or pte_lock
  *             zone->lru_lock (in mark_page_accessed, isolate_lru_page)
@@ -1053,7 +1053,7 @@ void page_add_file_rmap(struct page *page)
                __inc_zone_page_state(page, NR_FILE_MAPPED);
                mem_cgroup_inc_page_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED);
        }
-       mem_cgroup_end_page_stat(memcg, locked, flags);
+       mem_cgroup_end_page_stat(memcg, &locked, &flags);
 }
 
 static void page_remove_file_rmap(struct page *page)
@@ -1083,7 +1083,7 @@ static void page_remove_file_rmap(struct page *page)
        if (unlikely(PageMlocked(page)))
                clear_page_mlock(page);
 out:
-       mem_cgroup_end_page_stat(memcg, locked, flags);
+       mem_cgroup_end_page_stat(memcg, &locked, &flags);
 }
 
 /**
@@ -1260,7 +1260,7 @@ out_mlock:
        /*
         * We need mmap_sem locking, Otherwise VM_LOCKED check makes
         * unstable result and race. Plus, We can't wait here because
-        * we now hold anon_vma->rwsem or mapping->i_mmap_mutex.
+        * we now hold anon_vma->rwsem or mapping->i_mmap_rwsem.
         * if trylock failed, the page remain in evictable lru and later
         * vmscan could retry to move the page to unevictable lru if the
         * page is actually mlocked.
@@ -1684,13 +1684,14 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
         * The page lock not only makes sure that page->mapping cannot
         * suddenly be NULLified by truncation, it makes sure that the
         * structure at mapping cannot be freed and reused yet,
-        * so we can safely take mapping->i_mmap_mutex.
+        * so we can safely take mapping->i_mmap_rwsem.
         */
        VM_BUG_ON_PAGE(!PageLocked(page), page);
 
        if (!mapping)
                return ret;
-       mutex_lock(&mapping->i_mmap_mutex);
+
+       i_mmap_lock_read(mapping);
        vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
                unsigned long address = vma_address(page, vma);
 
@@ -1711,9 +1712,8 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
                goto done;
 
        ret = rwc->file_nonlinear(page, mapping, rwc->arg);
-
 done:
-       mutex_unlock(&mapping->i_mmap_mutex);
+       i_mmap_unlock_read(mapping);
        return ret;
 }