Ticket #2959: Autofs and MOUNT_UNDER_SCRATCH do not mix

The MOUNT_UNDER_SCRATCH feature comes with one drawback - automount in Linux doesn't understand namespaces. Hence, when automount triggers, it will mount the filesystem in the parent namespace and it's not available in the job.

You end up with an error message like this when mixing autofs and MOUNT_UNDER_SCRATCH:

[bbockelm@rcf-bockelman condor]$ condor_run ls /cvmfs/cms.cern.ch
ls: cannot open directory /cvmfs/cms.cern.ch: Too many levels of symbolic links

While this is technically a problem with automount, I think it'll be quite awhile before a fixed version is widely available. Hence, we should provide a workaround, such as upgrading autofs mountpoints to shared-subtrees.

[Append remarks]

Remarks:

2012-May-10 19:12:44 by bbockelm:
Crap. Missed a hunk from this patch. If only we had pull requests...

diff --git a/build/cmake/CondorConfigure.cmake b/build/cmake/CondorConfigure.cmake
index 2b120b5..213426a 100644
--- a/build/cmake/CondorConfigure.cmake
+++ b/build/cmake/CondorConfigure.cmake
@@ -146,6 +146,7 @@ if( NOT WINDOWS)
        check_library_exists(dl dlopen "" HAVE_DLOPEN)
        check_symbol_exists(res_init "sys/types.h;netinet/in.h;arpa/nameser.h;resolv.h" HAVE_DECL_RES_INIT)
        check_symbol_exists(MS_PRIVATE "sys/mount.h" HAVE_MS_PRIVATE)
+       check_symbol_exists(MS_SHARED  "sys/mount.h" HAVE_MS_SHARED)

        check_function_exists("access" HAVE_ACCESS)
        check_function_exists("clone" HAVE_CLONE)

2012-Aug-23 14:09:08 by zmiller:
Bulk change of target version from v070802 to v070803 using ./ticket-target-mover.
[Append remarks]

Properties:

Type: defect           Last Change: 2012-Aug-23 14:09
Status: resolved          Created: 2012-Apr-26 20:43
Fixed Version: v070803           Broken Version: v070705 
Priority:          Subsystem: Libs 
Assigned To: gthain           Derived From:  
Creator: bbockelm  Rust:  
Customer Group: cms  Visibility: public 
Notify:   Due Date:  

Related Check-ins:

2012-May-11 07:57   Check-in [32023]: Additional symbol check for Autofs && MOUNT_UNDER_SCRATCH ===GT:Fixed=== #2959 (By Timothy St. Clair )
2012-Apr-27 13:40   Check-in [31843]: bbockelms modification to handle autofs and mount_under_scratch ===GT:Fixed=== #2959 ===VersionHistory:None=== (By Timothy St. Clair )

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