1 files changed, 10 insertions, 8 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 45eba36fd673..c52f43a69eea 100644
--- 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)
@@ -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.
@@ -1635,7 +1635,7 @@ static struct anon_vma *rmap_walk_anon_lock(struct page *page,
 static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
 {
         struct anon_vma *anon_vma;
-        pgoff_t pgoff = page_to_pgoff(page);
+        pgoff_t pgoff;
         struct anon_vma_chain *avc;
         int ret = SWAP_AGAIN;
 
@@ -1643,6 +1643,7 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
         if (!anon_vma)
                 return ret;
 
+        pgoff = page_to_pgoff(page);
         anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) {
                 struct vm_area_struct *vma = avc->vma;
                 unsigned long address = vma_address(page, vma);
@@ -1676,7 +1677,7 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
 static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
 {
         struct address_space *mapping = page->mapping;
-        pgoff_t pgoff = page_to_pgoff(page);
+        pgoff_t pgoff;
         struct vm_area_struct *vma;
         int ret = SWAP_AGAIN;
 
@@ -1684,13 +1685,15 @@ 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);
+
+        pgoff = page_to_pgoff(page);
+        i_mmap_lock_read(mapping);
         vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
                 unsigned long address = vma_address(page, vma);
 
@@ -1711,9 +1714,8 @@ 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;
 }