Bug 991300

Summary: nfs: mount using symlink of a dir fails
Product: [Red Hat Storage] Red Hat Gluster Storage Reporter: Saurabh <saujain>
Component: gluster-nfsAssignee: Jiffin <jthottan>
Status: CLOSED ERRATA QA Contact: Saurabh <saujain>
Severity: high Docs Contact:
Priority: medium    
Version: 2.1CC: amainkar, divya, jthottan, mzywusko, ndevos, rhs-bugs, sharne, vagarwal, vbellur
Target Milestone: ---Keywords: Patch, ZStream
Target Release: RHGS 3.0.3Flags: jthottan: needinfo+
Hardware: x86_64   
OS: All   
Whiteboard:
Fixed In Version: glusterfs-3.6.0.33-1 Doc Type: Bug Fix
Doc Text:
Previously, Gluster-NFS did not resolve symbolic links into directory handle and mount failed. With this fix, if a symbolic link is consistent throughout the volume then the subdirectory mounts for symbolic link works.
 Story Points: ---
Clone Of: Environment:
Last Closed: 2015-01-15 13:36:45 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1157223    
Bug Blocks: 1162694    

Description Saurabh 2013-08-02 05:54:09 UTC 
Description of problem:
trying to do a mount, while providing path as symlink to a dir and it fails.
whereas for kernel nfs it works well.

Version-Release number of selected component (if applicable):
[root@nfs1 ~]# rpm -qa | grep glusterfs
glusterfs-fuse-3.4.0.13rhs-1.el6rhs.x86_64
glusterfs-3.4.0.13rhs-1.el6rhs.x86_64
glusterfs-server-3.4.0.13rhs-1.el6rhs.x86_64

How reproducible:
always

Steps to Reproduce:
1. create a volume, start it
2. mount the volume over nfs.
3. create a dir inside and symlink to this dir.

[root@rhsauto030 nfs-test2]# file symdir
symdir: symbolic link to `dir'
[root@rhsauto030 nfs-test2]# pwd
/mnt/nfs-test2
[root@rhsauto030 nfs-test2]# mount | grep nfs-test2
10.70.37.123:/dist-rep2 on /mnt/nfs-test2 type nfs (rw,addr=10.70.37.123)
[root@rhsauto030 nfs-test2]# 

4. try to do a mount, using symlink created in step 3.

[root@rhsauto030 nfs-test2]# mount -t nfs -o vers=3 10.70.37.123:/dist-rep2/symdir /mnt/nfs-test-dir/
mount.nfs: an incorrect mount option was specified

Actual results:
mount fails to hapen, 
packet trace while mount is tried out,
 73   1.482975   10.70.37.5 -> 10.70.37.123 NFS V3 NULL Call
 75   1.483534 10.70.37.123 -> 10.70.37.5   NFS V3 NULL Reply (Call In 73)
 95   1.488580   10.70.37.5 -> 10.70.37.123 MOUNT V3 NULL Call
 97   1.490332 10.70.37.123 -> 10.70.37.5   MOUNT V3 NULL Reply (Call In 95)
105   1.493355   10.70.37.5 -> 10.70.37.123 MOUNT V3 NULL Call
107   1.495088 10.70.37.123 -> 10.70.37.5   MOUNT V3 NULL Reply (Call In 105)
109   1.495406   10.70.37.5 -> 10.70.37.123 MOUNT V3 MNT Call /dist-rep2/symdir
110   1.498474 10.70.37.123 -> 10.70.37.5   MOUNT V3 MNT Reply (Call In 109)
117   1.500338   10.70.37.5 -> 10.70.37.123 NFS V3 FSINFO Call, FH:0xf36fddf6
118   1.501397 10.70.37.123 -> 10.70.37.5   NFS V3 FSINFO Reply (Call In 117)
119   1.501591   10.70.37.5 -> 10.70.37.123 NFS V3 PATHCONF Call, FH:0xf36fddf6
120   1.502558 10.70.37.123 -> 10.70.37.5   NFS V3 PATHCONF Reply (Call In 119)
122   1.509865   10.70.37.5 -> 10.70.37.123 NFS V3 FSINFO Call, FH:0xf36fddf6
123   1.511058 10.70.37.123 -> 10.70.37.5   NFS V3 FSINFO Reply (Call In 122)

Expected results:
our implementation should work similarly to kernel nfs implementation

Additional info:

similar stuff works for kernel works,

 [root@rhsauto030 saurabh]# file symdir
symdir: symbolic link to `dir/'


[root@rhsauto030 saurabh]# mount -t nfs -o vers=3 rhsqe-repo.lab.eng.blr.redhat.com:/opt/qa/saurabh/symdir /mnt/nfs-test-dir

[root@rhsauto030 saurabh]# pwd
/opt/qa/saurabh

162   5.035347   10.70.37.5 -> 10.70.34.52  NFS V3 NULL Call
164   5.035825  10.70.34.52 -> 10.70.37.5   NFS V3 NULL Reply (Call In 162)
171   5.037502   10.70.37.5 -> 10.70.34.52  MOUNT V3 NULL Call
172   5.038393  10.70.34.52 -> 10.70.37.5   MOUNT V3 NULL Reply (Call In 171)
173   5.038997   10.70.37.5 -> 10.70.34.52  MOUNT V3 NULL Call
174   5.039452  10.70.34.52 -> 10.70.37.5   MOUNT V3 NULL Reply (Call In 173)
175   5.039578   10.70.37.5 -> 10.70.34.52  MOUNT V3 MNT Call /opt/qa/saurabh/symdir
176   5.041213  10.70.34.52 -> 10.70.37.5   MOUNT V3 MNT Reply (Call In 175)
180   5.042339   10.70.37.5 -> 10.70.34.52  NFS V3 FSINFO Call, FH:0xfc4facec
181   5.042735  10.70.34.52 -> 10.70.37.5   NFS V3 FSINFO Reply (Call In 180)
182   5.042910   10.70.37.5 -> 10.70.34.52  NFS V3 PATHCONF Call, FH:0xfc4facec
183   5.043385  10.70.34.52 -> 10.70.37.5   NFS V3 PATHCONF Reply (Call In 182)
184   5.043507   10.70.37.5 -> 10.70.34.52  NFS V3 GETATTR Call, FH:0xfc4facec
185   5.044022  10.70.34.52 -> 10.70.37.5   NFS V3 GETATTR Reply (Call In 184)  Directory mode:0755 uid:1000 gid:1000
186   5.047614   10.70.37.5 -> 10.70.34.52  NFS V3 FSINFO Call, FH:0xfc4facec
187   5.048020  10.70.34.52 -> 10.70.37.5   NFS V3 FSINFO Reply (Call In 186)
188   5.048199   10.70.37.5 -> 10.70.34.52  NFS V3 GETATTR Call, FH:0xfc4facec
189   5.048627  10.70.34.52 -> 10.70.37.5   NFS V3 GETATTR Reply (Call In 188)  Directory mode:0755 uid:1000 gid:1000
Comment 3 Niels de Vos 2014-11-14 15:40:50 UTC 
Patch posted by Jiffin: https://code.engineering.redhat.com/gerrit/36702
Comment 4 Saurabh 2014-11-20 10:57:02 UTC 
Test done to verify this fix with these steps,

1. create a volume of 6x2 type, start it
2. mount the volume over nfs
3. create a directory inside mount-point, say dir1
4. create symlink for this directory.
5. mount with symlink.
6. execute some I/O say iozone.


So mount in step 5 and I/O in step6 were successful

Although, two BZs have been filed based on the case executed. 
BZ 1166051
BZ 1166060
Comment 5 Divya 2014-12-30 15:31:39 UTC 
Jiffin,

Please review the edited doc text and sign-off.
Comment 6 Jiffin 2015-01-12 12:55:21 UTC 
Divya,

The doc looks fine too me.
Comment 8 errata-xmlrpc 2015-01-15 13:36:45 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2015-0038.html