Dell H310, JBOD mode "hard error"

[Doug Ambrisko]

On Tue, Aug 13, 2013 at 07:46:56PM -0700, Sean Bruno wrote:
| On Sun, 2013-07-14 at 10:23 -0700, Sean Bruno wrote:
| > Not sure what to make of this.  I've tested a lot of svn revisions of
| > the thunderbolt code, but nothing looks obvious.  
| > 
| > When I use a single drive in "SYSPD" mode on a Dell H310 (falcon or
| > skinny drake) I get a /dev/mfisyspd0 device.  The JBOD mode *seems* to
| > work just fine as long as I don't do multiple things at once to it, e.g.
| > single user fsck works, but multiuser things die.
| > 
| > I get a failure case that emits errors such as:
| > 
| > g_vfs_done():error 27 in callback
| > mfisyspd0p2[READ(offset=7176192, length=425984)]mfisyspd0: hard error
| > error = 5
| > cmd=read 15360-16383
| > error 27 in callback
| > g_vfs_done():mfisyspd0: hard error mfisyspd0p2[READ(offset=7602176,
| > length=524288)]cmd=read error = 5
| > 16384-17407
| > error 27 in callback
| > g_vfs_done():mfisyspd0: hard error mfisyspd0p2[READ(offset=8126464,
| > length=524288)]cmd=read error = 5
| > 14560-15359
| > error 27 in callback
| > g_vfs_done():mfisyspd0: hard error mfisyspd0p2[READ(offset=7192576,
| > length=409600)]cmd=read error = 5
| > 15360-16383
| > 
| > 
| > Sean
| 
| Ah, I see something that Yahoo! does that FreeBSD does not finally.  We
| tune MAXPHYS *up* to (512 * 1024) because of performance and available
| memory.
| 
| mfi(4) set's its own (MFI_MAXPHYS) to (128 * 1024) instead of using the
| value from sys/param.h  (btw, I don't quite get why, but whatever).
| 
| Without a min() check in mfi_syspd.c that mimics the one in mfi_disk.c,
| Yahoo code falls over in "SYSPD" mode (mfi(4) real jbod mode).
| 
| Patch:
| 
| Index: mfi_syspd.c
| ===================================================================
| --- mfi_syspd.c	(revision 254313)
| +++ mfi_syspd.c	(working copy)
| @@ -128,7 +128,9 @@
|  	sc->pd_disk->d_drv1 = sc;
|  	sc->pd_disk->d_maxsize = sc->pd_controller->mfi_max_io * secsize;
|  	sc->pd_disk->d_name = "mfisyspd";
| -	sc->pd_disk->d_open = mfi_syspd_open;
| +	sc->pd_disk->d_maxsize = min(sc->pd_controller->mfi_max_io * secsize,
| +		(sc->pd_controller->mfi_max_sge - 1) * PAGE_SIZE);
| +
|  	sc->pd_disk->d_close = mfi_syspd_close;
|  	sc->pd_disk->d_strategy = mfi_syspd_strategy;
|  	sc->pd_disk->d_dump = mfi_syspd_dump;


That change for d_maxsize looks okay but do you really want to get
rid of d_open?  I assume this is a cut-n-paste type error and the patch
(hand editted) should be:

Index: mfi_syspd.c
===================================================================
--- mfi_syspd.c	(revision 254313)
+++ mfi_syspd.c	(working copy)
@@ -128,7 +128,8 @@
 	sc->pd_disk->d_drv1 = sc;
- 	sc->pd_disk->d_maxsize = sc->pd_controller->mfi_max_io * secsize;
+	sc->pd_disk->d_maxsize = min(sc->pd_controller->mfi_max_io * secsize,
+		(sc->pd_controller->mfi_max_sge - 1) * PAGE_SIZE);
 	sc->pd_disk->d_name = "mfisyspd";
	sc->pd_disk->d_open = mfi_syspd_open;
 	sc->pd_disk->d_close = mfi_syspd_close;
 	sc->pd_disk->d_strategy = mfi_syspd_strategy;
 	sc->pd_disk->d_dump = mfi_syspd_dump;

BTW, has mfiutil been updated to create real JBODs versus the RAID per
drive?  I know someone was talking about doing that.  A note on implementing
it, it also requires JBOD to be enabled in the controller.  I'm not sure
if all controllers support it.  I forget when I was playing with it.  I've
always wondering if we should change the name for the syspd disk node
but I left it for compatibility with LSI.  We could do an alias.  It is
good in away that it doesn't create /dev/mfid* nodes so that it is easier
to track bugs.

Thanks,

Doug A.