[PATCH 35/47] fnic: use dedicated device reset command

Hannes Reinecke
2017-06-28T08:33:26Z

Use a dedicated command to send a device reset instead of relying
on using the command which triggered the device failure.

Signed-off-by: Hannes Reinecke <hare@suse.com>
---
drivers/scsi/fnic/fnic_main.c | 2 ++
drivers/scsi/fnic/fnic_scsi.c | 78 +++++++++++++------------------------------
2 files changed, 26 insertions(+), 54 deletions(-)

diff --git a/drivers/scsi/fnic/fnic_main.c b/drivers/scsi/fnic/fnic_main.c
index aacadbf..22fd37c 100644
--- a/drivers/scsi/fnic/fnic_main.c
+++ b/drivers/scsi/fnic/fnic_main.c
@@ -706,6 +706,8 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
fnic->config.io_throttle_count));
}
fnic->fnic_max_tag_id = host->can_queue;
+ /* Reserve the last tag for device reset */
+ host->can_queue--;

host->max_lun = fnic->config.luns_per_tgt;
host->max_id = FNIC_MAX_FCP_TARGET;
diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c
index 731ec87..acf7d1d 100644
--- a/drivers/scsi/fnic/fnic_scsi.c
+++ b/drivers/scsi/fnic/fnic_scsi.c
@@ -2106,9 +2106,7 @@ static inline int fnic_queue_dr_io_req(struct fnic *fnic,
* successfully aborted, 1 otherwise
*/
static int fnic_clean_pending_aborts(struct fnic *fnic,
- struct scsi_cmnd *lr_sc,
- bool new_sc)
-
+ struct scsi_cmnd *lr_sc)
{
int tag, abt_tag;
struct fnic_io_req *io_req;
@@ -2129,7 +2127,7 @@ static int fnic_clean_pending_aborts(struct fnic *fnic,
* ignore this lun reset cmd if issued using new SC
* or cmds that do not belong to this lun
*/
- if (!sc || ((sc == lr_sc) && new_sc) || sc->device != lun_dev) {
+ if (!sc || sc == lr_sc || sc->device != lun_dev) {
spin_unlock_irqrestore(io_lock, flags);
continue;
}
@@ -2334,6 +2332,7 @@ static int fnic_clean_pending_aborts(struct fnic *fnic,
*/
int fnic_device_reset(struct scsi_cmnd *sc)
{
+ struct scsi_device *sdev = sc->device;
struct fc_lport *lp;
struct fnic *fnic;
struct fnic_io_req *io_req = NULL;
@@ -2348,18 +2347,16 @@ int fnic_device_reset(struct scsi_cmnd *sc)
struct reset_stats *reset_stats;
int tag = 0;
DECLARE_COMPLETION_ONSTACK(tm_done);
- int tag_gen_flag = 0; /*to track tags allocated by fnic driver*/
- bool new_sc = 0;

/* Wait for rport to unblock */
- rport = starget_to_rport(scsi_target(sc->device));
+ rport = starget_to_rport(scsi_target(sdev));
ret = fc_block_scsi_eh(rport);
if (ret)
return ret;

ret = FAILED;
/* Get local-port, check ready and link up */
- lp = shost_priv(sc->device->host);
+ lp = shost_priv(sdev->host);

fnic = lport_priv(lp);
fnic_stats = &fnic->fnic_stats;
@@ -2368,8 +2365,8 @@ int fnic_device_reset(struct scsi_cmnd *sc)
atomic64_inc(&reset_stats->device_resets);

FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
- "Device reset called FCID 0x%x, LUN 0x%llx sc 0x%p\n",
- rport->port_id, sc->device->lun, sc);
+ "Device reset called FCID 0x%x, LUN 0x%llx\n",
+ rport->port_id, sdev->lun);

if (lp->state != LPORT_ST_READY || !(lp->link_up))
goto fnic_device_reset_end;
@@ -2379,51 +2376,28 @@ int fnic_device_reset(struct scsi_cmnd *sc)
atomic64_inc(&fnic_stats->misc_stats.rport_not_ready);
goto fnic_device_reset_end;
}
-
- CMD_FLAGS(sc) = FNIC_DEVICE_RESET;
- /* Allocate tag if not present */
-
- tag = sc->request->tag;
- if (unlikely(tag < 0)) {
+ /* The last tag is reserved for device reset */
+ sc = scsi_host_find_tag(sdev->host, fnic->fnic_max_tag_id - 1);
+ io_lock = fnic_io_lock_hash(fnic, sc);
+ spin_lock_irqsave(io_lock, flags);
+ if (CMD_SP(sc)) {
/*
- * XXX(hch): current the midlayer fakes up a struct
- * request for the explicit reset ioctls, and those
- * don't have a tag allocated to them. The below
- * code pokes into midlayer structures to paper over
- * this design issue, but that won't work for blk-mq.
- *
- * Either someone who can actually test the hardware
- * will have to come up with a similar hack for the
- * blk-mq case, or we'll have to bite the bullet and
- * fix the way the EH ioctls work for real, but until
- * that happens we fail these explicit requests here.
+ * Reset tag busy
*/
-
- tag = fnic_scsi_host_start_tag(fnic, sc);
- if (unlikely(tag == SCSI_NO_TAG))
- goto fnic_device_reset_end;
- tag_gen_flag = 1;
- new_sc = 1;
+ spin_unlock_irqrestore(io_lock, flags);
+ goto fnic_device_reset_end;
}
- io_lock = fnic_io_lock_hash(fnic, sc);
- spin_lock_irqsave(io_lock, flags);
- io_req = (struct fnic_io_req *)CMD_SP(sc);
-
- /*
- * If there is a io_req attached to this command, then use it,
- * else allocate a new one.
- */
+ io_req = mempool_alloc(fnic->io_req_pool, GFP_ATOMIC);
if (!io_req) {
- io_req = mempool_alloc(fnic->io_req_pool, GFP_ATOMIC);
- if (!io_req) {
- spin_unlock_irqrestore(io_lock, flags);
- goto fnic_device_reset_end;
- }
- memset(io_req, 0, sizeof(*io_req));
- io_req->port_id = rport->port_id;
- CMD_SP(sc) = (char *)io_req;
+ spin_unlock_irqrestore(io_lock, flags);
+ goto fnic_device_reset_end;
}
+ memset(io_req, 0, sizeof(*io_req));
+ io_req->port_id = rport->port_id;
+ CMD_SP(sc) = (char *)io_req;
io_req->dr_done = &tm_done;
+
+ CMD_FLAGS(sc) = FNIC_DEVICE_RESET;
CMD_STATE(sc) = FNIC_IOREQ_CMD_PENDING;
CMD_LR_STATUS(sc) = FCPIO_INVALID_CODE;
spin_unlock_irqrestore(io_lock, flags);
@@ -2538,7 +2512,7 @@ int fnic_device_reset(struct scsi_cmnd *sc)
* the lun reset cmd. If all cmds get cleaned, the lun reset
* succeeds
*/
- if (fnic_clean_pending_aborts(fnic, sc, new_sc)) {
+ if (fnic_clean_pending_aborts(fnic, sc)) {
spin_lock_irqsave(io_lock, flags);
io_req = (struct fnic_io_req *)CMD_SP(sc);
FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
@@ -2575,10 +2549,6 @@ int fnic_device_reset(struct scsi_cmnd *sc)
(u64)sc->cmnd[4] << 8 | sc->cmnd[5]),
(((u64)CMD_FLAGS(sc) << 32) | CMD_STATE(sc)));

- /* free tag if it is allocated */
- if (unlikely(tag_gen_flag))
- fnic_scsi_host_end_tag(fnic, sc);
-
FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
"Returning from device reset %s\n",
(ret == SUCCESS) ?
--
1.8.5.6