1 files changed, 15 insertions, 5 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4dbaf89b1337..9254b3d58dbe 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1458,7 +1458,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
          */
 
         /* the destination must be opened for writing */
-        if (!(file->f_mode & FMODE_WRITE))
+        if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
                 return -EINVAL;
 
         ret = mnt_want_write(file->f_path.mnt);
@@ -1511,7 +1511,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 
         /* determine range to clone */
         ret = -EINVAL;
-        if (off >= src->i_size || off + len > src->i_size)
+        if (off + len > src->i_size || off + len < off)
                 goto out_unlock;
         if (len == 0)
                 olen = len = src->i_size - off;
@@ -1578,6 +1578,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
                         u64 disko = 0, diskl = 0;
                         u64 datao = 0, datal = 0;
                         u8 comp;
+                        u64 endoff;
 
                         size = btrfs_item_size_nr(leaf, slot);
                         read_extent_buffer(leaf, buf,
@@ -1712,9 +1713,18 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
                         btrfs_release_path(root, path);
 
                         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-                        if (new_key.offset + datal > inode->i_size)
-                                btrfs_i_size_write(inode,
-                                                   new_key.offset + datal);
+
+                        /*
+                         * we round up to the block size at eof when
+                         * determining which extents to clone above,
+                         * but shouldn't round up the file size
+                         */
+                        endoff = new_key.offset + datal;
+                        if (endoff > off+olen)
+                                endoff = off+olen;
+                        if (endoff > inode->i_size)
+                                btrfs_i_size_write(inode, endoff);
+
                         BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
                         ret = btrfs_update_inode(trans, root, inode);
                         BUG_ON(ret);