From: Brian Behlendorf <behlendorf1@llnl.gov>
Date: Tue, 14 Jun 2011 23:25:29 +0000 (-0700)
Subject: Handle /etc/mtab -> /proc/mounts symlink
X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=commitdiff_plain;h=e130330a874f4dec6628c094455180d4113c6aa1;hp=2e08aedba456dccddf6418908a55014e56cad226;p=zfs.git

Handle /etc/mtab -> /proc/mounts symlink

Under Fedora 15 /etc/mtab is now a symlink to /proc/mounts by
default.  When /etc/mtab is a symlink the mount.zfs helper
should not update it.   There was code in place to handle this
case but it used stat() which traverses the link and then issues
the stat on /proc/mounts.  We need to use lstat() to prevent the
link traversal and instead stat /etc/mtab.

Closes #270
---

diff --git a/cmd/mount_zfs/mount_zfs.c b/cmd/mount_zfs/mount_zfs.c
index e97b2b8..7173f56 100644
--- a/cmd/mount_zfs/mount_zfs.c
+++ b/cmd/mount_zfs/mount_zfs.c
@@ -252,7 +252,7 @@ mtab_is_writeable(void)
 	struct stat st;
 	int error, fd;
 
-	error = stat(MNTTAB, &st);
+	error = lstat(MNTTAB, &st);
 	if (error || S_ISLNK(st.st_mode))
 		return (0);