SCSI issue with 2.6.14-rc1

SCSI issue with 2.6.14-rc1

[Burton Windle]

Dell Poweredge 1300, MegaRAID SCSI with hardware RAID1. With 2.6.13, 
system was fine, but on 2.6.14-rc1, it sees the RAID array as a 0mb drive 
with 1 512-byte sector, and seems to have a bit of a problem mounting /

2.6.13:
megaraid: found 0x8086:0x1960:bus 0:slot 13:func 1
scsi0:Found MegaRAID controller at 0xf8802000, IRQ:185
megaraid: [1.06:1p00] detected 1 logical drives.
megaraid: channel[0] is raid.
megaraid: channel[1] is raid.
scsi0 : LSI Logic MegaRAID 1.06 254 commands 16 targs 5 chans 7 luns
scsi0: scanning scsi channel 0 for logical drives.
   Vendor: MegaRAID  Model: LD0 RAID1  8568R  Rev: 1.06
   Type:   Direct-Access                      ANSI SCSI revision: 02
scsi0: scanning scsi channel 4 [P0] for physical devices.
scsi0: scanning scsi channel 5 [P1] for physical devices.
st: Version 20050501, fixed bufsize 32768, s/g segs 256
SCSI device sda: 17547264 512-byte hdwr sectors (8984 MB)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
sda: asking for cache data failed
sda: assuming drive cache: write through
SCSI device sda: 17547264 512-byte hdwr sectors (8984 MB)
sda: asking for cache data failed
sda: assuming drive cache: write through
  sda: sda1
Attached scsi disk sda at scsi0, channel 0, id 0, lun 0

2.6.14-rc1:
megaraid: found 0x8086:0x1960:bus 0:slot 13:func 1
scsi0:Found MegaRAID controller at 0xf8802000, IRQ:185
megaraid: [1.06:1p00] detected 1 logical drives.
megaraid: channel[0] is raid.
megaraid: channel[1] is raid.
scsi0 : LSI Logic MegaRAID 1.06 254 commands 16 targs 5 chans 7 luns
scsi0: scanning scsi channel 0 for logical drives.
   Vendor: MegaRAID  Model: LD0 RAID1  8568R  Rev: 1.06
   Type:   Direct-Access                      ANSI SCSI revision: 02
scsi0: scanning scsi channel 4 [P0] for physical devices.
scsi0: scanning scsi channel 5 [P1] for physical devices.
st: Version 20050830, fixed bufsize 32768, s/g segs 256
sda : sector size 0 reported, assuming 512.
SCSI device sda: 1 512-byte hdwr sectors (0 MB)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
sda: asking for cache data failed
sda: assuming drive cache: write through
sda : sector size 0 reported, assuming 512.
SCSI device sda: 1 512-byte hdwr sectors (0 MB)
sda: asking for cache data failed
sda: assuming drive cache: write through
  sda: sda1
Attached scsi disk sda at scsi0, channel 0, id 0, lun 0



Linux RTIX-NM-003 2.6.13 #8 SMP Wed Aug 31 16:38:12 EDT 2005 i686 
GNU/Linux

Gnu C                  2.95.4
Gnu make               3.80
binutils               2.16.1
util-linux             2.12p
mount                  2.12p
module-init-tools      3.2-pre1
e2fsprogs              1.37
reiserfsprogs          line
reiser4progs           line
Linux C Library        2.3.5
Dynamic linker (ldd)   2.3.5
Procps                 3.2.5
Net-tools              1.60
Console-tools          0.2.3
Sh-utils               5.2.1

CONFIG_SCSI=y
CONFIG_SCSI_PROC_FS=y
CONFIG_BLK_DEV_SD=y
CONFIG_CHR_DEV_ST=y
CONFIG_SCSI_MULTI_LUN=y
CONFIG_SCSI_LOGGING=y
CONFIG_MEGARAID_LEGACY=y


-- 
Burton Windle                           bwindle@fint.org

Re: SCSI issue with 2.6.14-rc1

[Peter Chubb]

>>>>> "Burton" == Burton Windle <bwindle@fint.org> writes:

Burton> Dell Poweredge 1300, MegaRAID SCSI with hardware RAID1. With
Burton> 2.6.13, system was fine, but on 2.6.14-rc1, it sees the RAID
Burton> array as a 0mb drive with 1 512-byte sector, and seems to have
Burton> a bit of a problem mounting /

This sounds like the same problem I saw with the IA64 simscsi driver
--- the READ_CAPACITY scsi command now generates a scatterlist, and
some drivers don't cope.

I don't know whether the right fix is to change all the drivers to
understand a scatterlist, or to change sd_read_capacity() to not use 
scsi_execute_command().

--
Dr Peter Chubb  http://www.gelato.unsw.edu.au  peterc AT gelato.unsw.edu.au
The technical we do immediately,  the political takes *forever*

Re: SCSI issue with 2.6.14-rc1

[James Bottomley]

On Wed, 2005-09-14 at 07:55 +1000, Peter Chubb wrote:
> Burton> Dell Poweredge 1300, MegaRAID SCSI with hardware RAID1. With
> Burton> 2.6.13, system was fine, but on 2.6.14-rc1, it sees the RAID
> Burton> array as a 0mb drive with 1 512-byte sector, and seems to have
> Burton> a bit of a problem mounting /
> 
> This sounds like the same problem I saw with the IA64 simscsi driver
> --- the READ_CAPACITY scsi command now generates a scatterlist, and
> some drivers don't cope.
> 
> I don't know whether the right fix is to change all the drivers to
> understand a scatterlist, or to change sd_read_capacity() to not use 
> scsi_execute_command().

There's a fix for the megaraid issue floating around on this list.

The correct solution is for all drivers to understand scatterlists.
This is actually true of most of them; there are just a few scsi
emulators that didn't for certain commands.  These emulators are already
broken, since if these commands came via SG_IO, they'd be scatterlist
based, so the correct fix is in the emulators.

James