diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index dba6dd2..4c5e9f7 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1154,6 +1154,18 @@ static int do_journal_get_write_access(handle_t *handle,
  * transaction must include the content of the newly allocated blocks.
  * This content is expected to be set to zeroes by block_prepare_write().
  * 2006/10/14  SAW
+ * What we can do if some blocks was allocated?
+ * a) Stop transaction and do retry if possible, but what happend if
+ *    reboot comes after journal_force_commit, but before we exhaust
+ *    all retry attempts and caller call trancate?
+ *    We may get allocated blocks outside i_size. Witch is bad.
+ * b) Commit newly allocated blocks. And if reboot comes, user will be
+ *    surprised that i_size increased but blocks are zero filed. Witch is
+ *    also bad.
+ * c) Just return as match bytes as we can deal with rigth now back to
+ *    caller, and if reboot comes trunsaction was't closed so it will
+ *    be droped while journal replay.
+ * Only (c) tend to garantie attomic data operation.
  */
 static int ext3_prepare_failure(struct file *file, struct page *page,
 				unsigned from, unsigned to)
@@ -1186,7 +1198,7 @@ skip:
 			block_start = to;
 			break;
 		}
-		if (!buffer_mapped(bh))
+		if (!buffer_mapped(bh) || !buffer_uptodate(bh))
 		/* prepare_write failed on this bh */
 			break;
 		if (ext3_should_journal_data(mapping->host)) {
@@ -1204,8 +1216,8 @@ skip:
 	if (block_start <= from)
 		goto skip;
 
-	/* commit allocated and zeroed buffers */
-	return mapping->a_ops->commit_write(file, page, from, block_start);
+	/* return number of bytes till last mapped && uptodate block */
+	return block_start - from;
 }
 
 static int ext3_prepare_write(struct file *file, struct page *page,
@@ -1239,7 +1251,8 @@ retry:
 
 failure:
 	ret2 = ext3_prepare_failure(file, page, from, to);
-	if (ret2 < 0)
+	if (ret2)
+	/* ready to partial write, or fatal error */
 		return ret2;
 	if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
 		goto retry;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 806eee1..da39f80 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1153,6 +1153,18 @@ static int do_journal_get_write_access(handle_t *handle,
  * transaction must include the content of the newly allocated blocks.
  * This content is expected to be set to zeroes by block_prepare_write().
  * 2006/10/14  SAW
+ * What we can do if some blocks was allocated?
+ * a) Stop transaction and do retry if possible, but what happend if
+ *    reboot comes after journal_force_commit, but before we exhaust
+ *    all retry attempts and caller call trancate?
+ *    We may get allocated blocks outside i_size. Witch is bad.
+ * b) Commit newly allocated blocks. And if reboot comes, user will be
+ *    surprised that i_size increased but blocks are zero filed. Witch is
+ *    also bad.
+ * c) Just return as match bytes as we can deal with rigth now back to
+ *    caller, and if reboot comes trunsaction was't closed so it will
+ *    be droped while journal replay.
+ * Only (c) tend to garantie attomic data operation.
  */
 static int ext4_prepare_failure(struct file *file, struct page *page,
 				unsigned from, unsigned to)
@@ -1185,7 +1197,7 @@ skip:
 			block_start = to;
 			break;
 		}
-		if (!buffer_mapped(bh))
+		if (!buffer_mapped(bh) || !buffer_uptodate(bh))
 		/* prepare_write failed on this bh */
 			break;
 		if (ext4_should_journal_data(mapping->host)) {
@@ -1203,8 +1215,8 @@ skip:
 	if (block_start <= from)
 		goto skip;
 
-	/* commit allocated and zeroed buffers */
-	return mapping->a_ops->commit_write(file, page, from, block_start);
+	/* return number of bytes till last mapped && uptodate block */
+	return block_start - from;
 }
 
 static int ext4_prepare_write(struct file *file, struct page *page,
@@ -1238,7 +1250,8 @@ retry:
 
 failure:
 	ret2 = ext4_prepare_failure(file, page, from, to);
-	if (ret2 < 0)
+	if (ret2)
+	/* ready to partial write, or fatal error */
 		return ret2;
 	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
 		goto retry;