2.6.23-rc9 fails to boot for me; 2.6.22.9 works fine.
System is a Dell Poweredge with PERC 2/DC with RAID1 volume.
From 2.6.23-rc9:
Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2

ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx

PIIX4: IDE controller at PCI slot 0000:00:07.1

eth1: Optical link UP (Full Duplex, Flow Control: )

PIIX4: chipset revision 1

PIIX4: not 100% native mode: will probe irqs later

     ide1: BM-DMA at 0xffa8-0xffaf, BIOS settings: hdc:DMA, hdd:pio

hdc: SAMSUNG SC-140B, ATAPI CD/DVD-ROM drive

ide1 at 0x170-0x177,0x376 on irq 15

hdc: ATAPI 40X CD-ROM drive, 128kB Cache, UDMA(33)

Uniform CD-ROM driver Revision: 3.20

ide-floppy driver 0.99.newide

ACPI: PCI Interrupt 0000:00:0d.1[A] -> GSI 17 (level, low) -> IRQ 18

megaraid: found 0x8086:0x1960:bus 0:slot 13:func 1

scsi0:Found MegaRAID controller at 0xf8812000, IRQ:18

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.

scsi 0:0:0:0: Direct-Access     MegaRAID LD0 RAID1  8568R 1.06 PQ: 0 ANSI: 2

scsi0: scanning scsi channel 4 [P0] for physical devices.

scsi0: scanning scsi channel 5 [P1] for physical devices.

st: Version 20070203, fixed bufsize 32768, s/g segs 256

sd 0:0:0:0: [sda] Sector size 0 reported, assuming 512.

sd 0:0:0:0: [sda] 1 512-byte hardware sectors (0 MB)

sd 0:0:0:0: [sda] Write Protect is off

sd 0:0:0:0: [sda] Asking for cache data failed

sd 0:0:0:0: [sda] Assuming drive cache: write through

sd 0:0:0:0: [sda] Sector size 0 reported, assuming 512.

sd 0:0:0:0: [sda] 1 512-byte hardware sectors (0 MB)

sd 0:0:0:0: [sda] Write Protect is off

sd 0:0:0:0: [sda] Asking for cache data failed

sd 0:0:0:0: [sda] Assuming drive cache: write through

  sda: sda1

  sda: p1 exceeds device capacity

sd 0:0:0:0: [sda] Attached SCSI disk

PNP: PS/2 Controller [PNP0303:KBD,PNP0f13:MOU] at 0x60,...
[ message continues ]

Cc's added, the complete bug report is at

  http://lkml.org/lkml/2007/10/2/243
Thanks for your report.
Diff'ing the dmesg's shows:
<--  snip  -->
 scsi0: scanning scsi channel 4 [P0] for physical devices.

 scsi0: scanning scsi channel 5 [P1] for physical devices.

 st: Version 20070203, fixed bufsize 32768, s/g segs 256

-sd 0:0:0:0: [sda] 17547264 512-byte hardware sectors (8984 MB)

+sd 0:0:0:0: [sda] Sector size 0 reported, assuming 512.

+sd 0:0:0:0: [sda] 1 512-byte hardware sectors (0 MB)

 sd 0:0:0:0: [sda] Write Protect is off

 sd 0:0:0:0: [sda] Asking for cache data failed

 sd 0:0:0:0: [sda] Assuming drive cache: write through

-sd 0:0:0:0: [sda] 17547264 512-byte hardware sectors (8984 MB)

+sd 0:0:0:0: [sda] Sector size 0 reported, assuming 512.

+sd 0:0:0:0: [sda] 1 512-byte hardware sectors (0 MB)

 sd 0:0:0:0: [sda] Write Protect is off

 sd 0:0:0:0: [sda] Asking for cache data failed

 sd 0:0:0:0: [sda] Assuming drive cache: write through

  sda: sda1

+ sda: p1 exceeds device capacity
<--  snip  -->
Does reverting the commit below fix the problem?
cu

Adrian
commit 3f6270ef76f2ce5c134615a470685d6c2a66c07e

Author: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

Date:   Mon May 14 20:17:27 2007 +0900
    [SCSI] megaraid_old: convert to use the data buffer accessors
    - remove the unnecessary map_single path.
    - convert to use the new accessors for the sg lists and the

    parameters.
    Jens Axboe <jens.axboe@oracle.com> did the for_each_sg cleanup.
    Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

    Acked-by: Sumant Patro <sumant.patro@lsi.com>

    Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/megaraid.c b/drivers/scsi/megaraid.c

index 40ee07d..3907f67 100644

--- a/drivers/scsi/megaraid.c

+++ b/drivers/scsi/megaraid.c

@@ -523,10 +523,8 @@ mega_build_cmd(adapter_t *adapter, Scsi_Cmnd *cmd, int *busy)

 	/*

 	 * filter...
[ message continues ]

This is the problem piece I think.  We've reintroduced a very old bug:
commit 51c928c34fa7cff38df584ad01de988805877dba

Author: James Bottomley <James.Bottomley@SteelEye.com>

Date:   Sat Oct 1 09:38:05 2005 -0500
    [SCSI] Legacy MegaRAID: Fix READ CAPACITY
    Some Legacy megaraid cards can't actually cope with the scatter/gather

    version of the READ CAPACITY command (which is what we now send them

    since altering all SCSI internal I/O to go via the block layer).  Fix

    this (and a few other broken megaraid driver assumptions) by sending

    the non-sg version of the command if the sg list only has a single

    element.
    Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
So what we have to do is put back the check for use_sg == 1 and send

that as a bulk transfer command.
James
-

On Tue, 02 Oct 2007 15:38:13 -0500
Sorry about this. Can this fix the problem?
Thanks,
diff --git a/drivers/scsi/megaraid.c b/drivers/scsi/megaraid.c

index 3907f67..da56163 100644

--- a/drivers/scsi/megaraid.c

+++ b/drivers/scsi/megaraid.c

@@ -1753,6 +1753,14 @@ mega_build_sglist(adapter_t *adapter, scb_t *scb, u32 *buf, u32 *len)
 	*len = 0;
+	if (scsi_sg_count(cmd) == 1 && !adapter->has_64bit_addr) {

+		sg = scsi_sglist(cmd);

+		scb->dma_h_bulkdata = sg_dma_address(sg);

+		*buf = (u32)scb->dma_h_bulkdata;

+		*len = sg_dma_len(sg);

+		return 0;

+	}

+

 	scsi_for_each_sg(cmd, sg, sgcnt, idx) {

 		if (adapter->has_64bit_addr) {

 			scb->sgl64[idx].address = sg_dma_address(sg);

-

With this patch I see the correct logical disk size reported.

Thanks.
Sumant

-

On Wed, 3 Oct 2007 17:32:55 -0600
Great, thanks for testing!
Can you try the following patch instead of the above patch?
http://marc.info/?l=linux-scsi&m=119137033016550&w=2
I know the changes are pretty trivial and it should work...

-

Tomo, this is the patch I added.
--

Jens Axboe
-

Please excuse my comment in case this was already clear:
You are aware that this bug is a regression in 2.6.23-rc and the patch 
cu

Adrian
-- 
       "Is there not promise of rain?" Ling Tan asked suddenly out

        of the darkness. There had been need of rain for many days.

       "Only a promise," Lao Er said.

                                       Pearl S. Buck - Dragon Seed
-

On Thu, 4 Oct 2007 12:48:58 +0200
Oops, you are right. This should go via scsi-rc-fixes tree ASAP.

-

Irk, the scsi accessor stuff is already in, I forgot and thought it was

pending for 2.6.24. So rush the patch upstream please!
--

Jens Axboe
-

On Thu, 4 Oct 2007 09:28:34 +0200
Thanks. I thought that it will be sent via scsi-misc because the scsi

accessor patch introduced this bug. But either is ok with me.
BTW, please add my sign-off.
-

[SCSI] megaraid_old: fix scatter/gather for legacy megaraid cards
Some legacy megaraid cards (!has_64bit_addr case) can't cope with the

catter/gather version of the READ CAPACITY command. We need to send

the non-sg version of the command if the sg list only as a single

element.
commit 3f6270ef76f2ce5c134615a470685d6c2a66c07e reintroduced this bug,

which was fixed long ago (commit 51c928c34fa7cff38df584ad01de988805877dba).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

-

If it only affects the driver _after_ the scsi accessor patch and as

such doesn't screw over git-block, then I'll drop it for sure.
--

Jens Axboe
-

No, this is a release critical fix ... I'll roll it up and send it in

for 2.6.23.
James
-

On Tue, 02 Oct 2007 15:38:13 -0500
Sorry again. Needs to check sg count before dma mapping.
diff --git a/drivers/scsi/megaraid.c b/drivers/scsi/megaraid.c

index 3907f67..ae0b220 100644

--- a/drivers/scsi/megaraid.c

+++ b/drivers/scsi/megaraid.c

@@ -1737,9 +1737,12 @@ mega_build_sglist(adapter_t *adapter, scb_t *scb, u32 *buf, u32 *len)

 	Scsi_Cmnd	*cmd;

 	int	sgcnt;

 	int	idx;

+	int bulkdata;
 	cmd = scb->cmd;
+	bulkdata = (scsi_sg_count(cmd) == 1) ? 1 : 0;

+

 	/*

 	 * Copy Scatter-Gather list info into controller structure.

 	 *

@@ -1753,6 +1756,14 @@ mega_build_sglist(adapter_t *adapter, scb_t *scb, u32 *buf, u32 *len)
 	*len = 0;
+	if (bulkdata && !adapter->has_64bit_addr) {

+		sg = scsi_sglist(cmd);

+		scb->dma_h_bulkdata = sg_dma_address(sg);

+		*buf = (u32)scb->dma_h_bulkdata;

+		*len = sg_dma_len(sg);

+		return 0;

+	}

+

 	scsi_for_each_sg(cmd, sg, sgcnt, idx) {

 		if (adapter->has_64bit_addr) {

 			scb->sgl64[idx].address = sg_dma_address(sg);

-

Confirmed; reverting the above (snipped) patch does fix the issue.
--

Burton Windle                           bwindle@fint.org
-

I've created a bugzilla entry for your report at:
http://bugzilla.kernel.org/show_bug.cgi?id=9113
Please add a summary of your observations in there.
Greetings,

Rafael

-