mm/hugetlb: don't crash when HPAGE_SHIFT is 0

[linux-2.6] / fs / gfs2 / ops_address.c

diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index 2b556dd034bb6c35a64f7822da3aeeb06a23f22c..e64a1b04117ad5b27bb5fc1efd98ffe6295056a8 100644 (file)
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -499,31 +499,34 @@ static int __gfs2_readpage(void *file, struct page *page)
  * @file: The file to read
  * @page: The page of the file
  *
- * This deals with the locking required. We use a trylock in order to
- * avoid the page lock / glock ordering problems returning AOP_TRUNCATED_PAGE
- * in the event that we are unable to get the lock.
+ * This deals with the locking required. We have to unlock and
+ * relock the page in order to get the locking in the right
+ * order.
  */
 
 static int gfs2_readpage(struct file *file, struct page *page)
 {
-       struct gfs2_inode *ip = GFS2_I(page->mapping->host);
+       struct address_space *mapping = page->mapping;
+       struct gfs2_inode *ip = GFS2_I(mapping->host);
        struct gfs2_holder gh;
        int error;
 
-       gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|LM_FLAG_TRY_1CB, &gh);
+       unlock_page(page);
+       gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
        error = gfs2_glock_nq_atime(&gh);
-       if (unlikely(error)) {
-               unlock_page(page);
+       if (unlikely(error))
                goto out;
-       }
-       error = __gfs2_readpage(file, page);
+       error = AOP_TRUNCATED_PAGE;
+       lock_page(page);
+       if (page->mapping == mapping && !PageUptodate(page))
+               error = __gfs2_readpage(file, page);
+       else
+               unlock_page(page);
        gfs2_glock_dq(&gh);
 out:
        gfs2_holder_uninit(&gh);
-       if (error == GLR_TRYFAILED) {
-               yield();
-               return AOP_TRUNCATED_PAGE;
-       }
+       if (error && error != AOP_TRUNCATED_PAGE)
+               lock_page(page);
        return error;
 }