[PATCH AUTOSEL for 4.14 32/97] scsi: mpt3sas: Proper handling of set/clear of "ATA command pending" flag.

Sasha Levin
2018-03-19T15:55:47Z

From: Chaitra P B <chaitra.basappa@broadcom.com>

[ Upstream commit f49d4aed1315a7b766d855f1367142e682b0cc87 ]

1. In IO path, setting of "ATA command pending" flag early before device
removal, invalid device handle etc., checks causes any new commands
to be always returned with SAM_STAT_BUSY and when the driver removes
the drive the SML issues SYNC Cache command and that command is
always returned with SAM_STAT_BUSY and thus making SYNC Cache command
to requeued.

2. If the driver gets an ATA PT command for a SATA drive then the driver
set "ATA command pending" flag in device specific data structure not
to allow any further commands until the ATA PT command is completed.
However, after setting the flag if the driver decides to return the
command back to upper layers without actually issuing to the firmware
(i.e., returns from qcmd failure return paths) then the corresponding
flag is not cleared and this prevents the driver from sending any new
commands to the drive.

This patch fixes above two issues by setting of "ATA command pending"
flag after checking for whether device deleted, invalid device handle,
device busy with task management. And by setting "ATA command pending"
flag to false in all of the qcmd failure return paths after setting the
flag.

Signed-off-by: Chaitra P B <chaitra.basappa@broadcom.com>
Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
drivers/scsi/mpt3sas/mpt3sas_scsih.c | 28 +++++++++++++++-------------
1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index 33ff691878e2..5b953aee19c2 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -4103,19 +4103,6 @@ scsih_qcmd(struct Scsi_Host *shost, struct scsi_cmnd *scmd)
return 0;
}

- /*
- * Bug work around for firmware SATL handling. The loop
- * is based on atomic operations and ensures consistency
- * since we're lockless at this point
- */
- do {
- if (test_bit(0, &sas_device_priv_data->ata_command_pending)) {
- scmd->result = SAM_STAT_BUSY;
- scmd->scsi_done(scmd);
- return 0;
- }
- } while (_scsih_set_satl_pending(scmd, true));
-
sas_target_priv_data = sas_device_priv_data->sas_target;

/* invalid device handle */
@@ -4141,6 +4128,19 @@ scsih_qcmd(struct Scsi_Host *shost, struct scsi_cmnd *scmd)
sas_device_priv_data->block)
return SCSI_MLQUEUE_DEVICE_BUSY;

+ /*
+ * Bug work around for firmware SATL handling. The loop
+ * is based on atomic operations and ensures consistency
+ * since we're lockless at this point
+ */
+ do {
+ if (test_bit(0, &sas_device_priv_data->ata_command_pending)) {
+ scmd->result = SAM_STAT_BUSY;
+ scmd->scsi_done(scmd);
+ return 0;
+ }
+ } while (_scsih_set_satl_pending(scmd, true));
+
if (scmd->sc_data_direction == DMA_FROM_DEVICE)
mpi_control = MPI2_SCSIIO_CONTROL_READ;
else if (scmd->sc_data_direction == DMA_TO_DEVICE)
@@ -4167,6 +4167,7 @@ scsih_qcmd(struct Scsi_Host *shost, struct scsi_cmnd *scmd)
if (!smid) {
pr_err(MPT3SAS_FMT "%s: failed obtaining a smid\n",
ioc->name, __func__);
+ _scsih_set_satl_pending(scmd, false);
goto out;
}
mpi_request = mpt3sas_base_get_msg_frame(ioc, smid);
@@ -4197,6 +4198,7 @@ scsih_qcmd(struct Scsi_Host *shost, struct scsi_cmnd *scmd)
if (mpi_request->DataLength) {
if (ioc->build_sg_scmd(ioc, scmd, smid)) {
mpt3sas_base_free_smid(ioc, smid);
+ _scsih_set_satl_pending(scmd, false);
goto out;
}
} else
--
2.14.1