[GFS2] Add a comment in ops_export.c

Ass a comment explaining the slightly odd construct used to
pass error values back.

Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/ops_export.c b/fs/gfs2/ops_export.c
index 4b8c6a9..470e882 100644 (file)
--- a/fs/gfs2/ops_export.c
+++ b/fs/gfs2/ops_export.c
@@ -182,6 +182,10 @@ static struct dentry *gfs2_get_parent(struct dentry *child)
 
        if (!inode)
                return ERR_PTR(-ENOENT);
+       /*
+        * In case of an error, @inode carries the error value, and we
+        * have to return that as a(n invalid) pointer to dentry.
+        */
        if (IS_ERR(inode))
                return ERR_PTR(PTR_ERR(inode));