[12/12] Btrfs: Fix file clone when source offset is not 0

Commit Message

Li Zefan Jan. 27, 2011, 8:46 a.m. UTC

None

Patch

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index f87552a..1b61dab 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1788,7 +1788,10 @@  static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 
 			memcpy(&new_key, &key, sizeof(new_key));
 			new_key.objectid = inode->i_ino;
-			new_key.offset = key.offset + destoff - off;
+			if (off <= key.offset)
+				new_key.offset = key.offset + destoff - off;
+			else
+				new_key.offset = destoff;
 
 			trans = btrfs_start_transaction(root, 1);
 			if (IS_ERR(trans)) {