1 files changed, 18 insertions, 3 deletions

diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index b3b7e8475359..30c15622174f 100644
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -197,7 +197,19 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
         void *kaddr;
         int error;
 
-        BUG_ON(page->index);
+        /*
+         * Due to the order of unstuffing files and ->nopage(), we can be
+         * asked for a zero page in the case of a stuffed file being extended,
+         * so we need to supply one here. It doesn't happen often.
+         */
+        if (unlikely(page->index)) {
+                kaddr = kmap_atomic(page, KM_USER0);
+                memset(kaddr, 0, PAGE_CACHE_SIZE);
+                kunmap_atomic(kaddr, KM_USER0);
+                flush_dcache_page(page);
+                SetPageUptodate(page);
+                return 0;
+        }
 
         error = gfs2_meta_inode_buffer(ip, &dibh);
         if (error)
@@ -208,9 +220,8 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
                ip->i_di.di_size);
         memset(kaddr + ip->i_di.di_size, 0, PAGE_CACHE_SIZE - ip->i_di.di_size);
         kunmap_atomic(kaddr, KM_USER0);
-
+        flush_dcache_page(page);
         brelse(dibh);
-
         SetPageUptodate(page);
 
         return 0;
@@ -507,7 +518,9 @@ static int gfs2_commit_write(struct file *file, struct page *page,
                 gfs2_quota_unlock(ip);
                 gfs2_alloc_put(ip);
         }
+        unlock_page(page);
         gfs2_glock_dq_m(1, &ip->i_gh);
+        lock_page(page);
         gfs2_holder_uninit(&ip->i_gh);
         return 0;
 
@@ -520,7 +533,9 @@ fail_endtrans:
                 gfs2_quota_unlock(ip);
                 gfs2_alloc_put(ip);
         }
+        unlock_page(page);
         gfs2_glock_dq_m(1, &ip->i_gh);
+        lock_page(page);
         gfs2_holder_uninit(&ip->i_gh);
 fail_nounlock:
         ClearPageUptodate(page);