Messages in this thread | | | Date | Mon, 14 Sep 2009 22:50:38 +0400 | From | Vladislav Bolkhovitin <> | Subject | Re: [RFC PATCH 0/19] A kernel-level configfs enabled generic target engine for Linux v2.6.32 |
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Nicholas A. Bellinger, on 09/12/2009 05:55 AM wrote: > Greetings all, > > This is my humble request for review and inclusion of > Target_Core_Mod/ConfigFS v3.2 from lio-core-2.6.git code into mainline > v2.6.32. With TCM v3.2, the two major SPC-4 SCSI target mode fabric > features that have now been completed: Persistent Reservation APTPL and > implict/explict ALUA are the first all optional SPC4 defined feature > implementation of PR and ALUA in the Linux OSS target theatre using an > upstream user-driven virtual filesystem directory hierarchy structure > based on configfs that can be configured in realtime in combination with > interpreted userspace code. > > Both of these new features are now being used to provide Persistent Reservations > across target power loss and asymmetric multipath I/O to both Linux and non-Linux > clients. There is also an optional ALUA transition delay logic that has been > included to futher debug and improve existing upstream client side Linux kernel code > using TCM v3.2. These patches have been diffed against v2.6.31, and tested on x86 > 32-bit HVM, x86_64 KVM, and powerpc. > > There is cleanup work continuing to make the TCM code to use dprintk(), > and some include cleanups, and other minor fixes. The code has also > been run through checkpatch again since the posting in April, and all > errors have been removed, with the exception of one ConfigFS macro > define triggering a checkpatch false positive. > > As with the posting of the TCM v3.0 code earlier in April, I have > decided to break up the submissions into the generic target_core_mod > piece (this patch series) and then a seperate one that will be appearing > in the next days for v3.2 of the LIO-Target iSCSI fabric module. > > More Information about Target_Core_Mod/ConfigFS, and PR and ALUA: > > http://www.linux-iscsi.org/index.php/Target_Core_Mod/ConfigFS > http://www.linux-iscsi.org/index.php/Persistent_Reservations > http://www.linux-iscsi.org/index.php/ALUA > > The complete v3.x TCM CLI operations set can be found here: > > http://www.linux-iscsi.org/index.php/Lio-utils#v3.1_TCM_CLI_operations > > Instructions and examples for getting setup: > > http://linux-iscsi.org/builds/docs/LIO-3.0-Users_Reference_Manual.pdf > http://www.linux-iscsi.org/index.php/Howto#Start_target_core_mod
Some questions among many I have:
1. Where and how TCM is better over the existing mainline target framework STGT to justify such a move as adding a new piece of code doing the same job?
2. On the linux-iscsi.org main page (BTW, the comparison on that page isn't fully correct about STGT and SCST) you claim that TCM is a generic target engine. But how can you prove (and test) that if there are no hardware target drivers for TCM?
Also patch 7 implements MIBs through procfs. Procfs is for long time forbidden for adding anything like that, so you can't push it in the mainline.
Vlad
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