1 files changed, 31 insertions, 9 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 970977aab224..538f65a79ec5 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2177,6 +2177,11 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
         if (!(src_file->f_mode & FMODE_READ))
                 goto out_fput;
 
+        /* don't make the dst file partly checksummed */
+        if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
+            (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
+                goto out_fput;
+
         ret = -EISDIR;
         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
                 goto out_fput;
@@ -2220,6 +2225,16 @@ 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;
+        }
+
+        /* truncate page cache pages from target inode range */
+        truncate_inode_pages_range(&inode->i_data, destoff,
+                                   PAGE_CACHE_ALIGN(destoff + len) - 1);
+
         /* do any pending delalloc/csum calc on src, one way or
            another, and lock file content */
         while (1) {
@@ -2236,10 +2251,6 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
                 btrfs_wait_ordered_range(src, off, len);
         }
 
-        /* truncate page cache pages from target inode range */
-        truncate_inode_pages_range(&inode->i_data, off,
-                                   ALIGN(off + len, PAGE_CACHE_SIZE) - 1);
-
         /* clone data */
         key.objectid = btrfs_ino(src);
         key.type = BTRFS_EXTENT_DATA_KEY;
@@ -2317,7 +2328,12 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
                         else
                                 new_key.offset = destoff;
 
-                        trans = btrfs_start_transaction(root, 1);
+                        /*
+                         * 1 - adjusting old extent (we may have to split it)
+                         * 1 - add new extent
+                         * 1 - inode update
+                         */
+                        trans = btrfs_start_transaction(root, 3);
                         if (IS_ERR(trans)) {
                                 ret = PTR_ERR(trans);
                                 goto out;
@@ -2325,14 +2341,21 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 
                         if (type == BTRFS_FILE_EXTENT_REG ||
                             type == BTRFS_FILE_EXTENT_PREALLOC) {
+                                /*
+                                 *    a  | --- range to clone ---|  b
+                                 * | ------------- extent ------------- |
+                                 */
+
+                                /* substract range b */
+                                if (key.offset + datal > off + len)
+                                        datal = off + len - key.offset;
+
+                                /* substract range a */
                                 if (off > key.offset) {
                                         datao += off - key.offset;
                                         datal -= off - key.offset;
                                 }
 
-                                if (key.offset + datal > off + len)
-                                        datal = off + len - key.offset;
-
                                 ret = btrfs_drop_extents(trans, inode,
                                                          new_key.offset,
                                                          new_key.offset + datal,
@@ -2429,7 +2452,6 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
                         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);
                         btrfs_end_transaction(trans, root);