Re: [PATCH v2] block: Increase BLK_DEF_MAX_SECTORS_CAP

[Keith Busch <kbusch@kernel.org>]

On Thu, Apr 02, 2026 at 05:02:22AM +0900, Damien Le Moal wrote:
> On 4/1/26 19:32, Mira Limbeck wrote:
> > 
> > Apr 01 11:41:19 pve-test-hba kernel: sd 9:2:2:0: [sdc] tag#3962 page boundary curr_buff: 0x00000000f4d7cfce
> > Apr 01 11:41:19 pve-test-hba kernel: BUG: unable to handle page fault for address: ff3a241243d70000
> > Apr 01 11:41:19 pve-test-hba kernel: #PF: supervisor write access in kernel mode
> > Apr 01 11:41:19 pve-test-hba kernel: #PF: error_code(0x0002) - not-present page
> > Apr 01 11:41:19 pve-test-hba kernel: PGD 100010067 P4D 10066d067 PUD 10066e067 PMD 11f0fa067 PTE 0
> > Apr 01 11:41:19 pve-test-hba kernel: Oops: Oops: 0002 [#3] SMP NOPTI
> > Apr 01 11:41:19 pve-test-hba kernel: CPU: 15 UID: 0 PID: 6695 Comm: vgs Tainted: G      D W   E       7.0.0-rc6 #19 PREEMPT(full)
> > Apr 01 11:41:19 pve-test-hba kernel: Tainted: [D]=DIE, [W]=WARN, [E]=UNSIGNED_MODULE
> > Apr 01 11:41:19 pve-test-hba kernel: Hardware name: <snip>
> > Apr 01 11:41:19 pve-test-hba kernel: RIP: 0010:_base_build_sg_scmd_ieee+0x478/0x590 [mpt3sas]
> 
> There may be an issue with the mpt3sas driver with large commands.
> 
> However, I am using that driver all day long and doing lots of testing with
> gigantic read/write commands all the time. I have never seen any issues.
> The difference is that I am using the SAS-SATA FW for the Broadcom HBA, so no
> NVMe support, and my target devices are SAS or SATA HDDs, not SSDs.

It's only the NVMe attached ones that use base_make_prp_nvme, and it
looks like the ioc->pcie_sgl_dma_pool that provides the buffer for the
entries is too small for a transfer larger than 2MB. So it's overrunning
the allocated buffer.