exportfs: Return the minimum required handle size

The exportfs encode handle function should return the minimum required
handle size. This helps user to find out the handle size by passing 0
handle size in the first step and then redoing to the call again with
the returned handle size value.

Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 6 insertions, 2 deletions

diff --git a/fs/ocfs2/export.c b/fs/ocfs2/export.c
index 5dbc3062b4fd..254652a9b542 100644
--- a/fs/ocfs2/export.c
+++ b/fs/ocfs2/export.c
@@ -197,8 +197,12 @@ static int ocfs2_encode_fh(struct dentry *dentry, u32 *fh_in, int *max_len,
                    dentry->d_name.len, dentry->d_name.name,
                    fh, len, connectable);
 
-        if (len < 3 || (connectable && len < 6)) {
-                mlog(ML_ERROR, "fh buffer is too small for encoding\n");
+        if (connectable && (len < 6)) {
+                *max_len = 6;
+                type = 255;
+                goto bail;
+        } else if (len < 3) {
+                *max_len = 3;
                 type = 255;
                 goto bail;
         }