From: Li Zefan <lizf@cn.fujitsu.com>
Date: Sun, 11 Sep 2011 14:52:25 +0000 (-0400)
Subject: Btrfs: add dummy extent if dst offset excceeds file end in
X-Git-Tag: v3.12-rc1~4691^2~8
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d525e8ab022cb000e6e31a515ba8c3cf0d9c6130;p=kernel%2Fkernel-generic.git

Btrfs: add dummy extent if dst offset excceeds file end in

You can see there's no file extent with range [0, 4096]. Check this by
btrfsck:

 # btrfsck /dev/sda7
 root 5 inode 258 errors 100
 ...

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
---

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 028a4b8..63b4de1 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2228,6 +2228,12 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 	    !IS_ALIGNED(destoff, bs))
 		goto out_unlock;
 
+	if (destoff > inode->i_size) {
+		ret = btrfs_cont_expand(inode, inode->i_size, destoff);
+		if (ret)
+			goto out_unlock;
+	}
+
 	/* do any pending delalloc/csum calc on src, one way or
 	   another, and lock file content */
 	while (1) {