Support off-line files on SAM-QFS for Samba in Solaris [PSARC/2009/381 FastTrack timeout 07/13/2009]

[Garrett D'Amore]

Is the supporting code for this coming from upstream, or is this a new 
invention at Sun?  (Specifically, are there compatibility concerns for 
the samfs share configuration directive?)

    - Garrett

Daniel Hain wrote:
> I'm submitting this fasttrack for Jiri Sasek. This proposal seeks patch binding
> and will timeout on 07/13/2009.
>
> The listed imported interfaces from libsam.so are currently classified as Stable
> by the last approved PSARC case (PSARC/2001/599/ SAM_FS and QFS 4.0). The case 
> for SAM-QFS 5.0  (PSARC/2007/588) lists them as Unstable, but that case has not
> been approved. Discussion with the SAM-QFS team indicates that they feel the 
> classification of these interfaces is still Stable.
>
> -Dan
>
>
> Template Version: @(#)sac_nextcase 1.68 02/23/09 SMI
> This information is Copyright 2009 Sun Microsystems
> 1. Introduction
>     1.1. Project/Component Working Name:
> 	 Support off-line files on SAM-QFS for Samba in Solaris
>     1.2. Name of Document Author/Supplier:
> 	 Author:  Jiri Sasek
>     1.3  Date of This Document:
> 	06 July, 2009
> 4. Technical Description
> Proposal:
>
>         Support off-line files on SAM-QFS for Samba in Solaris.
>
> Detail:
>
> 	Samba is CIFS volume and printing server.
>
> 	The current version of Samba (3.0.34) integrated in Solaris
>         does not support off-line file attribute for files stored on
>         a SAM-FS volume when located on an off-line storage (a tape).
>
> 	Such situation has the following consequences on MS Windows
>         clients:
>
> 	 - Client's attempt to acces an off-line file will fail on 
>            timeout which is set too short to access a file stored
>            on a tape or any other external (off-line) storage.
>
> 	 - If MS Windows Eplorer's curent directory is set to
> 	   a directory full of off-lined files it causes a "storm"
> 	   of the tape changer arms when thumbnails are being generated.
>
>         The solution is to let Samba use libsam.so library, [4], which
>         provides the off-line information for files stored on a
>         off-line storage (a tape).  Since this library is optional
>         on Solaris then it is necessary to use lazy binding option for
>         linking this library with Samba.  The lazy binding option makes
>         sure that "smbd" (Samba daemon) will run even if libsamfs.so is
> 	not present on the system.
>
> 	When "samfs share = yes" configuration option is set in smb.conf
> 	(Samba configuration file) and libsamfs.so is not present on the
> 	system then calling the lazy linked library-call will not complete
> 	the dlopen(2) call successfuly and the standard message from the
> 	run-time linker notifying about is redirected from the stderr
> 	output to the "smbd" log file appropriate to the CIFS session
> 	serviced by this "smbd" daemon. Samba log files can be configured
> 	as described in smb.conf(4). In the standard distribution such log
> 	file is located on the "/var/samba/log/log.<hostname|IP>" path.
>
>         SAM-FS library libsamfs.so is delivered by optional packages
> 	SUNWsamfsr SUNWsamfsu and should be installed from the external
> 	source.
>      
> Exported Interfaces: (uncommited)
>
>    ---------------------------------------------------------------------
>    FILE_ATTRIBUTE_OFFLINE flag (0x00001000) in "Attributes" of
>    SMB_QUERY_FILE_BASIC_INFO response CIFS message will indicate the
>    off/on-line file status of files located on SAM-QFS share
>
>    ---------------------------------------------------------------------
>    smb.conf option "samfs share = yes|no" (default: no)
>
> Imported Interfaces:
>
>    The following functions from libsamfs.so are used:
>
>    ---------------------------------------------------------------------
>    sam_stat()		| File status calls available from libsam library
>    sam_segment_stat()	| returning the "struct sam_stat"
>
> References:
>
> [1] http://samba.org/
>     Author(s) of Samba: Andrew Tridgel, Jeremy Alisson, Michael Adam...
>     please check Samba.org to obtain the full list of the core team members
>     please also check the source code for external contributors
> [2] Common Internet File System (CIFS) Technical Reference (Revision: 1.0)
>     http://snia.org/
> [3] 6737005 samba should handle samfs WORM and offline files gracefully
> [4] http://www.opensolaris.org/os/project/samqfs/sourcecode/
>
>
>
> 6. Resources and Schedule
>     6.4. Steering Committee requested information
>    	6.4.1. Consolidation C-team Name:
> 		ON
>     6.5. ARC review type: FastTrack
>     6.6. ARC Exposure: open
>
>