[GFS2] Fix ordering of page disposal vs. glock_dq

In case of unlinked files with dirty pages GFS2 wasn't clearing
the pages in quite the right order. This patch clears the pages
earlier (before the qlock_dq) to avoid the situation that the
release of the glock results in attempting to write back data that
has already been deallocated.

This fixes Red Hat bugzilla: #220117

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/gfs2/ops_super.c b/fs/gfs2/ops_super.c
index b2837839eed..c22738cdbf2 100644
--- a/fs/gfs2/ops_super.c
+++ b/fs/gfs2/ops_super.c
@@ -429,6 +429,12 @@ static void gfs2_delete_inode(struct inode *inode)
         }
 
         error = gfs2_dinode_dealloc(ip);
+        /*
+         * Must do this before unlock to avoid trying to write back
+         * potentially dirty data now that inode no longer exists
+         * on disk.
+         */
+        truncate_inode_pages(&inode->i_data, 0);
 
 out_unlock:
         gfs2_glock_dq(&ip->i_iopen_gh);