Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw

* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw:
  [GFS2] Fix GFS2's use of do_div() in its quota calculations
  [GFS2] Remove unused declaration
  [GFS2] Remove support for unused and pointless flag
  [GFS2] Replace rgrp "recent list" with mru list
  [GFS2] Allow local DF locks when holding a cached EX glock
  [GFS2] Fix delayed demote race
  [GFS2] don't call permission()
  [GFS2] Fix module building
  [GFS2] Glock documentation
  [GFS2] Remove all_list from lock_dlm
  [GFS2] Remove obsolete conversion deadlock avoidance code
  [GFS2] Remove remote lock dropping code
  [GFS2] kernel panic mounting volume
  [GFS2] Revise readpage locking
  [GFS2] Fix ordering of args for list_add
  [GFS2] trivial sparse lock annotations
  [GFS2] No lock_nolock
  [GFS2] Fix ordering bug in lock_dlm
  [GFS2] Clean up the glock core

1 files changed, 20 insertions, 20 deletions

diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index f55394e57cb..e64a1b04117 100644
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -499,34 +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 gfs2_holder *gh;
+	struct address_space *mapping = page->mapping;
+	struct gfs2_inode *ip = GFS2_I(mapping->host);
+	struct gfs2_holder gh;
 	int error;
 
-	gh = gfs2_glock_is_locked_by_me(ip->i_gl);
-	if (!gh) {
-		gh = kmalloc(sizeof(struct gfs2_holder), GFP_NOFS);
-		if (!gh)
-			return -ENOBUFS;
-		gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, 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))
+		goto out;
+	error = AOP_TRUNCATED_PAGE;
+	lock_page(page);
+	if (page->mapping == mapping && !PageUptodate(page))
+		error = __gfs2_readpage(file, page);
+	else
 		unlock_page(page);
-		error = gfs2_glock_nq_atime(gh);
-		if (likely(error != 0))
-			goto out;
-		return AOP_TRUNCATED_PAGE;
-	}
-	error = __gfs2_readpage(file, page);
-	gfs2_glock_dq(gh);
+	gfs2_glock_dq(&gh);
 out:
-	gfs2_holder_uninit(gh);
-	kfree(gh);
+	gfs2_holder_uninit(&gh);
+	if (error && error != AOP_TRUNCATED_PAGE)
+		lock_page(page);
 	return error;
 }