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>
---
drivers/scsi/mpt3sas/mpt3sas_scsih.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index b5c966e..55332a3 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -4644,6 +4644,8 @@ _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);
@@ -4703,6 +4705,20 @@ _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;
+ 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\n");
+ xfer_cnt = (xfer_cnt / sector_sz) * 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
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