From f2e767bb5d6ee0d988cb7d4e54b0b21175802b6b Mon Sep 17 00:00:00 2001 From: Ram Pai Date: Thu, 26 Jan 2017 16:37:01 -0200 Subject: [PATCH] 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 Signed-off-by: Guilherme G. Piccoli Signed-off-by: Ram Pai Acked-by: Sreekanth Reddy Signed-off-by: Martin K. Petersen --- drivers/scsi/mpt3sas/mpt3sas_scsih.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c index 75f3fce1c867..268103182d34 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c +++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c @@ -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); -- 2.20.1