From: Ram Pai <linux...@us.ibm.com> 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. Reported-by: Mauricio Faria De Oliveira <mauri...@linux.vnet.ibm.com> Signed-off-by: Guilherme G. Piccoli <gpicc...@linux.vnet.ibm.com> Signed-off-by: Ram Pai <linux...@us.ibm.com> Acked-by: Sreekanth Reddy <sreekanth.re...@broadcom.com> --- v2->v3: * Changed division to round_down() [suggestion by Martin]. drivers/scsi/mpt3sas/mpt3sas_scsih.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c index 75f3fce..a6b6f58 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c +++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c @@ -4657,6 +4657,8 @@ _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; + struct request *req; mpi_reply = mpt3sas_base_get_reply_virt_addr(ioc, reply); scmd = _scsih_scsi_lookup_get_clear(ioc, smid); @@ -4715,6 +4717,21 @@ _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; + req = scmd->request; + if (unlikely(sector_sz && req && (req->cmd_type == REQ_TYPE_FS) && + (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); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html