From 4d728ec7aefdca5419d2ebfb28c147e81a4b59f4 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 26 Jan 2011 14:10:43 +0800 Subject: [PATCH] Btrfs: Fix file clone when source offset is not 0 Suppose: - the source extent is: [0, 100] - the src offset is 10 - the clone length is 90 - the dest offset is 0 This statement: new_key.offset = key.offset + destoff - off will produce such an extent for the dest file: [ino, BTRFS_EXTENT_DATA_KEY, -10] , which is obviously wrong. Signed-off-by: Li Zefan --- fs/btrfs/ioctl.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index f87552a1d7ea..1b61dab64062 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)) { -- 2.30.2