scsi: mpt3sas: Force request partial completion alignment

The firmware or device, possibly under a heavy I/O load, can return on a
partial unaligned boundary. Scsi-ml expects these requests to be
completed on an alignment boundary. Scsi-ml blindly requeues the I/O
without checking the alignment boundary of the I/O request for the
remaining bytes. This leads to errors, since devices cannot perform
non-aligned read/write operations.

This patch fixes the issue in the driver. It aligns unaligned
completions of FS requests, by truncating them to the nearest alignment
boundary.

[mkp: simplified if statement]

Reported-by: Mauricio Faria De Oliveira <mauricfo@linux.vnet.ibm.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Acked-by: Sreekanth Reddy <Sreekanth.Reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Ram Pai 2017-01-26 16:37:01 -02:00 committed by Martin K. Petersen
parent 2780f3c8f0
commit f2e767bb5d

View File

@ -4657,6 +4657,7 @@ _scsih_io_done(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 msix_index, u32 reply)
struct MPT3SAS_DEVICE *sas_device_priv_data;
u32 response_code = 0;
unsigned long flags;
unsigned int sector_sz;
mpi_reply = mpt3sas_base_get_reply_virt_addr(ioc, reply);
scmd = _scsih_scsi_lookup_get_clear(ioc, smid);
@ -4715,6 +4716,20 @@ _scsih_io_done(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 msix_index, u32 reply)
}
xfer_cnt = le32_to_cpu(mpi_reply->TransferCount);
/* In case of bogus fw or device, we could end up having
* unaligned partial completion. We can force alignment here,
* then scsi-ml does not need to handle this misbehavior.
*/
sector_sz = scmd->device->sector_size;
if (unlikely(scmd->request->cmd_type == REQ_TYPE_FS && sector_sz &&
xfer_cnt % sector_sz)) {
sdev_printk(KERN_INFO, scmd->device,
"unaligned partial completion avoided (xfer_cnt=%u, sector_sz=%u)\n",
xfer_cnt, sector_sz);
xfer_cnt = round_down(xfer_cnt, sector_sz);
}
scsi_set_resid(scmd, scsi_bufflen(scmd) - xfer_cnt);
if (ioc_status & MPI2_IOCSTATUS_FLAG_LOG_INFO_AVAILABLE)
log_info = le32_to_cpu(mpi_reply->IOCLogInfo);