1 files changed, 22 insertions, 3 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 0c9a5ee3e106..4241d0cff062 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -637,13 +637,29 @@ found:
                 }
 
                 /*
+                 * We have to zeroout blocks before inserting them into extent
+                 * status tree. Otherwise someone could look them up there and
+                 * use them before they are really zeroed.
+                 */
+                if (flags & EXT4_GET_BLOCKS_ZERO &&
+                    map->m_flags & EXT4_MAP_MAPPED &&
+                    map->m_flags & EXT4_MAP_NEW) {
+                        ret = ext4_issue_zeroout(inode, map->m_lblk,
+                                                 map->m_pblk, map->m_len);
+                        if (ret) {
+                                retval = ret;
+                                goto out_sem;
+                        }
+                }
+
+                /*
                  * If the extent has been zeroed out, we don't need to update
                  * extent status tree.
                  */
                 if ((flags & EXT4_GET_BLOCKS_PRE_IO) &&
                     ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
                         if (ext4_es_is_written(&es))
-                                goto has_zeroout;
+                                goto out_sem;
                 }
                 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
                                 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
@@ -654,11 +670,13 @@ found:
                         status |= EXTENT_STATUS_DELAYED;
                 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
                                             map->m_pblk, status);
-                if (ret < 0)
+                if (ret < 0) {
                         retval = ret;
+                        goto out_sem;
+                }
         }
 
-has_zeroout:
+out_sem:
         up_write((&EXT4_I(inode)->i_data_sem));
         if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
                 ret = check_block_validity(inode, map);
@@ -3083,6 +3101,7 @@ int ext4_get_block_dax(struct inode *inode, sector_t iblock,
                    struct buffer_head *bh_result, int create)
 {
         int flags = EXT4_GET_BLOCKS_PRE_IO | EXT4_GET_BLOCKS_UNWRIT_EXT;
+
         if (create)
                 flags |= EXT4_GET_BLOCKS_CREATE;
         ext4_debug("ext4_get_block_dax: inode %lu, create flag %d\n",