---

yaml
---
r: 273097
b: refs/heads/master
c: ba06208
h: refs/heads/master
i:
  273095: 278922c
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4e96b2dbbf1d7e81f22047a50f862555a6cb87cb
+refs/heads/master: ba06208a1315ab2d2217e09c79582b886c9f629e

trunk/fs/ext4/extents.c

@@ -4162,17 +4162,14 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
 	struct address_space *mapping = inode->i_mapping;
 	struct ext4_map_blocks map;
 	handle_t *handle;
-	loff_t first_block_offset, last_block_offset, block_len;
-	loff_t first_page, last_page, first_page_offset, last_page_offset;
+	loff_t first_page, last_page, page_len;
+	loff_t first_page_offset, last_page_offset;
 	int ret, credits, blocks_released, err = 0;
 
 	first_block = (offset + sb->s_blocksize - 1) >>
 		EXT4_BLOCK_SIZE_BITS(sb);
 	last_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
 
-	first_block_offset = first_block << EXT4_BLOCK_SIZE_BITS(sb);
-	last_block_offset = last_block << EXT4_BLOCK_SIZE_BITS(sb);
-
 	first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 	last_page = (offset + length) >> PAGE_CACHE_SHIFT;
 
@@ -4211,24 +4208,44 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
 		goto out;
 
 	/*
-	 * Now we need to zero out the un block aligned data.
-	 * If the file is smaller than a block, just
-	 * zero out the middle
+	 * Now we need to zero out the non-page-aligned data in the
+	 * pages at the start and tail of the hole, and unmap the buffer
+	 * heads for the block aligned regions of the page that were
+	 * completely zeroed.
 	 */
-	if (first_block > last_block)
-		ext4_block_zero_page_range(handle, mapping, offset, length);
-	else {
-		/* zero out the head of the hole before the first block */
-		block_len  = first_block_offset - offset;
-		if (block_len > 0)
-			ext4_block_zero_page_range(handle, mapping,
-						   offset, block_len);
-
-		/* zero out the tail of the hole after the last block */
-		block_len = offset + length - last_block_offset;
-		if (block_len > 0) {
-			ext4_block_zero_page_range(handle, mapping,
-					last_block_offset, block_len);
+	if (first_page > last_page) {
+		/*
+		 * If the file space being truncated is contained within a page
+		 * just zero out and unmap the middle of that page
+		 */
+		err = ext4_discard_partial_page_buffers(handle,
+			mapping, offset, length, 0);
+
+		if (err)
+			goto out;
+	} else {
+		/*
+		 * zero out and unmap the partial page that contains
+		 * the start of the hole
+		 */
+		page_len  = first_page_offset - offset;
+		if (page_len > 0) {
+			err = ext4_discard_partial_page_buffers(handle, mapping,
+						   offset, page_len, 0);
+			if (err)
+				goto out;
+		}
+
+		/*
+		 * zero out and unmap the partial page that contains
+		 * the end of the hole
+		 */
+		page_len = offset + length - last_page_offset;
+		if (page_len > 0) {
+			err = ext4_discard_partial_page_buffers(handle, mapping,
+					last_page_offset, page_len, 0);
+			if (err)
+				goto out;
 		}
 	}