From cfa37548ebc880580782b245f2d233ed540e7a01 Mon Sep 17 00:00:00 2001
From: Chris Siebenmann <cks.github@cs.toronto.edu>
Date: Wed, 5 Sep 2018 01:26:56 -0400
Subject: [PATCH] Correctly handle errors from kern_path

As a regular kernel function, kern_path() returns errors as negative
errnos, such as -ELOOP. zfsctl_snapdir_vget() must convert these into
the positive errnos used throughout the ZFS code when it returns them
to other ZFS functions so that the ZFS code properly sees them as
errors.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Siebenmann <cks.git01@cs.toronto.edu>
Closes #7764
Closes #7864
---
 module/zfs/zfs_ctldir.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/module/zfs/zfs_ctldir.c b/module/zfs/zfs_ctldir.c
index 8a35c99471..f5cfdb55d7 100644
--- a/module/zfs/zfs_ctldir.c
+++ b/module/zfs/zfs_ctldir.c
@@ -1177,7 +1177,7 @@ zfsctl_snapdir_vget(struct super_block *sb, uint64_t objsetid, int gen,
 		goto out;
 
 	/* Trigger automount */
-	error = kern_path(mnt, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &path);
+	error = -kern_path(mnt, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &path);
 	if (error)
 		goto out;