[PATCH] ocfs2: fix oops in mmap_truncate testing

[pandora-kernel.git] / fs / ocfs2 / aops.c

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 17964c0..1db0801 100644 (file)
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -174,10 +174,17 @@ static int ocfs2_get_block(struct inode *inode, sector_t iblock,
         * need to use BH_New is when we're extending i_size on a file
         * system which doesn't support holes, in which case BH_New
         * allows block_prepare_write() to zero.
+        *
+        * If we see this on a sparse file system, then a truncate has
+        * raced us and removed the cluster. In this case, we clear
+        * the buffers dirty and uptodate bits and let the buffer code
+        * ignore it as a hole.
         */
-       mlog_bug_on_msg(create && p_blkno == 0 && ocfs2_sparse_alloc(osb),
-                       "ino %lu, iblock %llu\n", inode->i_ino,
-                       (unsigned long long)iblock);
+       if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) {
+               clear_buffer_dirty(bh_result);
+               clear_buffer_uptodate(bh_result);
+               goto bail;
+       }
 
        /* Treat the unwritten extent as a hole for zeroing purposes. */
        if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))