1 files changed, 87 insertions, 11 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index c8c687b5d9a..1d456b2ac37 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3298,15 +3298,19 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 	ext4_fsblk_t newblock = 0;
 	int err = 0, depth, ret;
 	unsigned int allocated = 0;
+	unsigned int punched_out = 0;
+	unsigned int result = 0;
 	struct ext4_allocation_request ar;
 	ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
+	struct ext4_map_blocks punch_map;
 
 	ext_debug("blocks %u/%u requested for inode %lu\n",
 		  map->m_lblk, map->m_len, inode->i_ino);
 	trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
 
 	/* check in cache */
-	if (ext4_ext_in_cache(inode, map->m_lblk, &newex)) {
+	if (ext4_ext_in_cache(inode, map->m_lblk, &newex) &&
+		((flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) == 0)) {
 		if (!newex.ee_start_lo && !newex.ee_start_hi) {
 			if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
 				/*
@@ -3371,16 +3375,84 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 			ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
 				  ee_block, ee_len, newblock);
 
-			/* Do not put uninitialized extent in the cache */
-			if (!ext4_ext_is_uninitialized(ex)) {
-				ext4_ext_put_in_cache(inode, ee_block,
-							ee_len, ee_start);
-				goto out;
+			if ((flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) == 0) {
+				/*
+				 * Do not put uninitialized extent
+				 * in the cache
+				 */
+				if (!ext4_ext_is_uninitialized(ex)) {
+					ext4_ext_put_in_cache(inode, ee_block,
+						ee_len, ee_start);
+					goto out;
+				}
+				ret = ext4_ext_handle_uninitialized_extents(
+					handle, inode, map, path, flags,
+					allocated, newblock);
+				return ret;
 			}
-			ret = ext4_ext_handle_uninitialized_extents(handle,
-					inode, map, path, flags, allocated,
-					newblock);
-			return ret;
+
+			/*
+			 * Punch out the map length, but only to the
+			 * end of the extent
+			 */
+			punched_out = allocated < map->m_len ?
+				allocated : map->m_len;
+
+			/*
+			 * Sense extents need to be converted to
+			 * uninitialized, they must fit in an
+			 * uninitialized extent
+			 */
+			if (punched_out > EXT_UNINIT_MAX_LEN)
+				punched_out = EXT_UNINIT_MAX_LEN;
+
+			punch_map.m_lblk = map->m_lblk;
+			punch_map.m_pblk = newblock;
+			punch_map.m_len = punched_out;
+			punch_map.m_flags = 0;
+
+			/* Check to see if the extent needs to be split */
+			if (punch_map.m_len != ee_len ||
+				punch_map.m_lblk != ee_block) {
+
+				ret = ext4_split_extent(handle, inode,
+				path, &punch_map, 0,
+				EXT4_GET_BLOCKS_PUNCH_OUT_EXT |
+				EXT4_GET_BLOCKS_PRE_IO);
+
+				if (ret < 0) {
+					err = ret;
+					goto out2;
+				}
+				/*
+				 * find extent for the block at
+				 * the start of the hole
+				 */
+				ext4_ext_drop_refs(path);
+				kfree(path);
+
+				path = ext4_ext_find_extent(inode,
+				map->m_lblk, NULL);
+				if (IS_ERR(path)) {
+					err = PTR_ERR(path);
+					path = NULL;
+					goto out2;
+				}
+
+				depth = ext_depth(inode);
+				ex = path[depth].p_ext;
+				ee_len = ext4_ext_get_actual_len(ex);
+				ee_block = le32_to_cpu(ex->ee_block);
+				ee_start = ext4_ext_pblock(ex);
+
+			}
+
+			ext4_ext_mark_uninitialized(ex);
+
+			err = ext4_ext_remove_space(inode, map->m_lblk,
+				map->m_lblk + punched_out);
+
+			goto out2;
 		}
 	}
 
@@ -3525,7 +3597,11 @@ out2:
 	}
 	trace_ext4_ext_map_blocks_exit(inode, map->m_lblk,
 		newblock, map->m_len, err ? err : allocated);
-	return err ? err : allocated;
+
+	result = (flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) ?
+			punched_out : allocated;
+
+	return err ? err : result;
 }
 
 void ext4_ext_truncate(struct inode *inode)