+++ This bug was initially created as a clone of Bug #1093093 +++

+++ This bug was initially created as a clone of Bug #1043558 +++

Description of problem:

when chown a file on nfsv4 mount it seems to not respect NFSv4 no_root_squash option:

NFS server export:
[root@nfs ~]# cat /etc/exports
/scratch *(rw,fsid=0,async,insecure,no_root_squash)

[root@nfs ~]# exportfs -rv
exporting *:/scratch

NFS Client:
[root@client ~]# mount -t nfs  -o vers=4 nfs.example.org:/ /mnt/rhel6/

[root@client ~]# cat /proc/mounts
rootfs / rootfs rw 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,relatime 0 0
devtmpfs /dev devtmpfs rw,relatime,size=500204k,nr_inodes=125051,mode=755 0 0
devpts /dev/pts devpts rw,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /dev/shm tmpfs rw,relatime 0 0
/dev/mapper/myvg-rootvol / ext4 rw,relatime,barrier=1,data=ordered 0 0
/proc/bus/usb /proc/bus/usb usbfs rw,relatime 0 0
/dev/vda1 /boot ext3 rw,relatime,errors=continue,user_xattr,acl,barrier=1,data=ordered 0 0
none /proc/sys/fs/binfmt_misc binfmt_misc rw,relatime 0 0
sunrpc /var/lib/nfs/rpc_pipefs rpc_pipefs rw,relatime 0 0
nfs.example.org:/ /mnt/rhel6 nfs4 rw,relatime,vers=4,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=10.33.20.36,minorversion=0,local_lock=none,addr=10.33.20.128 0 0


Create a file:
[root@client ~]# touch /mnt/rhel6/testfile_root
[root@client ~]# ll /mnt/rhel6/testfile_root
-rw-r--r-- 1 root root 0 Dec 16  2013 /mnt/rhel6/testfile_root

Chown the file:
[root@client ~]# chown root:root /mnt/rhel6/testfile_root
[root@client ~]# ll /mnt/rhel6/testfile_root
-rw-r--r-- 1 nobody nobody 0 Dec 16  2013 /mnt/rhel6/testfile_root

Doing the same for a "normal" user works as expected:
[root@client ~]# su - test

Create a file:
[test@client ~]$ touch /mnt/rhel6/testfile_test
[test@client ~]$ ll /mnt/rhel6/testfile_test
-rw-rw-r-- 1 test test 0 Dec 16  2013 /mnt/rhel6/testfile_test

Chown the file:
[test@client ~]$ chown test:test /mnt/rhel6/testfile_test
[test@client ~]$ ll /mnt/rhel6/testfile_test
-rw-rw-r-- 1 test test 0 Dec 16  2013 /mnt/rhel6/testfile_test


How reproducible:
always

Steps to Reproduce:
1. cat /etc/exports 
/scratch *(rw,fsid=0,async,insecure,no_root_squash)

2. # mount -t nfs  -o vers=4 nfs.example.org:/ /mnt/rhel6/

3. # touch /mnt/rhel6/testfile_root
=> check file perms:
-rw-r--r-- 1 root root 0 Dec 16  2013 /mnt/rhel6/testfile_root

4. # chown root:root /mnt/rhel6/testfile_root
=> check file perms:
-rw-r--r-- 1 nobody nobody 0 Dec 16  2013 /mnt/rhel6/testfile_root

Actual results:
chown to root:root results in nobody:nobody

Expected results:
chown to root:root results in root:root



--- Additional comment from Martin Schuppert on 2013-12-16 11:29:55 EST ---

It works when setting nfs4_disable_idmapping=n

[root@client ~]# cat /etc/modprobe.d/nfs.conf 
options nfs nfs4_disable_idmapping=n


[root@client ~]# mount -t nfs  -o vers=4 nfs.example.org:/ /mnt/rhel6/
[root@client ~]# touch /mnt/rhel6/testfile_rootttt
[root@client ~]# ll /mnt/rhel6/testfile_rootttt
-rw-r--r-- 1 root root 0 Dec 16  2013 /mnt/rhel6/testfile_rootttt

[root@client ~]# chown root:root /mnt/rhel6/testfile_rootttt
[root@client ~]# ll /mnt/rhel6/testfile_rootttt
-rw-r--r-- 1 root root 0 Dec 16  2013 /mnt/rhel6/testfile_rootttt
..

--- Additional comment from Steve Dickson on 2014-04-30 10:55:30 EDT ---

This is the needed fix  for libnfsidmap 

diff -up ./libnfsidmap.c.orig ./libnfsidmap.c
--- ./libnfsidmap.c.orig	2014-04-30 10:19:28.000000000 -0400
+++ ./libnfsidmap.c	2014-04-30 10:49:05.000000000 -0400
@@ -99,8 +99,12 @@ static char * toupper_str(char *s)
 static int id_as_chars(char *name, int *id)
 {
 	long int value = strtol(name, NULL, 10);
-	if (value == 0)
-		return 0;
+
+	if (value == 0) {
+		/* check for zero id values */
+		if (strcmp(name, "0") != 0)
+			return 0;
+	}
 	*id = (int)value;
 	return 1;
 }

--- Additional comment from Steve Dickson on 2014-04-30 10:56:31 EDT ---

Looking for a QE ack...