3 files changed, 14 insertions, 10 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 38fde4e11714..7d42ab8fe6e1 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -928,14 +928,11 @@ xfs_file_remap_range(
         loff_t          len,
         unsigned int    remap_flags)
 {
-        int             ret;
-
         if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
                 return -EINVAL;
 
-        ret = xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out,
+        return xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out,
                         len, remap_flags);
-        return ret < 0 ? ret : len;
 }
 
 STATIC int
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 79dec457f7fb..4abb2aea8f31 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1122,13 +1122,15 @@ xfs_reflink_remap_blocks(
         loff_t                  pos_in,
         struct xfs_inode        *dest,
         loff_t                  pos_out,
-        loff_t                  remap_len)
+        loff_t                  remap_len,
+        loff_t                  *remapped)
 {
         struct xfs_bmbt_irec    imap;
         xfs_fileoff_t           srcoff;
         xfs_fileoff_t           destoff;
         xfs_filblks_t           len;
         xfs_filblks_t           range_len;
+        xfs_filblks_t           remapped_len = 0;
         xfs_off_t               new_isize = pos_out + remap_len;
         int                     nimaps;
         int                     error = 0;
@@ -1175,10 +1177,13 @@ xfs_reflink_remap_blocks(
                 srcoff += range_len;
                 destoff += range_len;
                 len -= range_len;
+                remapped_len += range_len;
         }
 
         if (error)
                 trace_xfs_reflink_remap_blocks_error(dest, error, _RET_IP_);
+        *remapped = min_t(loff_t, remap_len,
+                          XFS_FSB_TO_B(src->i_mount, remapped_len));
         return error;
 }
 
@@ -1387,7 +1392,7 @@ out_unlock:
 /*
  * Link a range of blocks from one file to another.
  */
-int
+loff_t
 xfs_reflink_remap_range(
         struct file             *file_in,
         loff_t                  pos_in,
@@ -1401,8 +1406,9 @@ xfs_reflink_remap_range(
         struct inode            *inode_out = file_inode(file_out);
         struct xfs_inode        *dest = XFS_I(inode_out);
         struct xfs_mount        *mp = src->i_mount;
+        loff_t                  remapped = 0;
         xfs_extlen_t            cowextsize;
-        ssize_t                 ret;
+        int                     ret;
 
         if (!xfs_sb_version_hasreflink(&mp->m_sb))
                 return -EOPNOTSUPP;
@@ -1418,7 +1424,8 @@ xfs_reflink_remap_range(
 
         trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);
 
-        ret = xfs_reflink_remap_blocks(src, pos_in, dest, pos_out, len);
+        ret = xfs_reflink_remap_blocks(src, pos_in, dest, pos_out, len,
+                        &remapped);
         if (ret)
                 goto out_unlock;
 
@@ -1441,7 +1448,7 @@ out_unlock:
         xfs_reflink_remap_unlock(file_in, file_out);
         if (ret)
                 trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_);
-        return ret;
+        return remapped > 0 ? remapped : ret;
 }
 
 /*
diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h
index c3c46c276fe1..cbc26ff79a8f 100644
--- a/fs/xfs/xfs_reflink.h
+++ b/fs/xfs/xfs_reflink.h
@@ -27,7 +27,7 @@ extern int xfs_reflink_cancel_cow_range(struct xfs_inode *ip, xfs_off_t offset,
 extern int xfs_reflink_end_cow(struct xfs_inode *ip, xfs_off_t offset,
                 xfs_off_t count);
 extern int xfs_reflink_recover_cow(struct xfs_mount *mp);
-extern int xfs_reflink_remap_range(struct file *file_in, loff_t pos_in,
+extern loff_t xfs_reflink_remap_range(struct file *file_in, loff_t pos_in,
                 struct file *file_out, loff_t pos_out, loff_t len,
                 unsigned int remap_flags);
 extern int xfs_reflink_inode_has_shared_extents(struct xfs_trans *tp,