[PATCH RFC v2 09/24] fnic: use reserved commands

John Garry
2020-03-10T16:30:53Z

From: Hannes Reinecke <hare@suse.com>

Remove hack to get tag for the reset command by using reserved
commands.

Signed-off-by: Hannes Reinecke <hare@suse.com>
---
drivers/scsi/fnic/fnic_scsi.c | 377 ++++++++++++++++------------------
1 file changed, 172 insertions(+), 205 deletions(-)

diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c
index b60795893994..e96c4bbf2374 100644
--- a/drivers/scsi/fnic/fnic_scsi.c
+++ b/drivers/scsi/fnic/fnic_scsi.c
@@ -2118,165 +2118,174 @@ static inline int fnic_queue_dr_io_req(struct fnic *fnic,
return ret;
}

-/*
- * Clean up any pending aborts on the lun
- * For each outstanding IO on this lun, whose abort is not completed by fw,
- * issue a local abort. Wait for abort to complete. Return 0 if all commands
- * successfully aborted, 1 otherwise
- */
-static int fnic_clean_pending_aborts(struct fnic *fnic,
- struct scsi_cmnd *lr_sc,
- bool new_sc)
+struct fnic_pending_aborts_iter_data {
+ struct fnic *fnic;
+ struct scsi_device *lun_dev;
+ int ret;
+};

+static bool fnic_pending_aborts_iter(struct scsi_cmnd *sc,
+ void *data, bool reserved)
{
- int tag, abt_tag;
+ struct fnic_pending_aborts_iter_data *iter_data = data;
+ struct fnic *fnic = iter_data->fnic;
+ struct scsi_device *lun_dev = iter_data->lun_dev;
+ int abt_tag = sc->request->tag;
struct fnic_io_req *io_req;
spinlock_t *io_lock;
unsigned long flags;
- int ret = 0;
- struct scsi_cmnd *sc;
struct scsi_lun fc_lun;
- struct scsi_device *lun_dev = lr_sc->device;
DECLARE_COMPLETION_ONSTACK(tm_done);
enum fnic_ioreq_state old_ioreq_state;

- for (tag = 0; tag < fnic->fnic_max_tag_id; tag++) {
- io_lock = fnic_io_lock_tag(fnic, tag);
- spin_lock_irqsave(io_lock, flags);
- sc = scsi_host_find_tag(fnic->lport->host, tag);
- /*
- * 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) {
- spin_unlock_irqrestore(io_lock, flags);
- continue;
- }
-
- io_req = (struct fnic_io_req *)CMD_SP(sc);
+ if (sc->device != lun_dev)
+ return true;
+ if (reserved)
+ return true;

- if (!io_req || sc->device != lun_dev) {
- spin_unlock_irqrestore(io_lock, flags);
- continue;
- }
-
- /*
- * Found IO that is still pending with firmware and
- * belongs to the LUN that we are resetting
- */
- FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
- "Found IO in %s on lun\n",
- fnic_ioreq_state_to_str(CMD_STATE(sc)));
-
- if (CMD_STATE(sc) == FNIC_IOREQ_ABTS_PENDING) {
- spin_unlock_irqrestore(io_lock, flags);
- continue;
- }
- if ((CMD_FLAGS(sc) & FNIC_DEVICE_RESET) &&
- (!(CMD_FLAGS(sc) & FNIC_DEV_RST_ISSUED))) {
- FNIC_SCSI_DBG(KERN_INFO, fnic->lport->host,
- "%s dev rst not pending sc 0x%p\n", __func__,
- sc);
- spin_unlock_irqrestore(io_lock, flags);
- continue;
- }
+ io_lock = fnic_io_lock_tag(fnic, abt_tag);
+ spin_lock_irqsave(io_lock, flags);
+ io_req = (struct fnic_io_req *)CMD_SP(sc);
+ if (!io_req) {
+ spin_unlock_irqrestore(io_lock, flags);
+ return true;
+ }

- if (io_req->abts_done)
- shost_printk(KERN_ERR, fnic->lport->host,
- "%s: io_req->abts_done is set state is %s\n",
- __func__, fnic_ioreq_state_to_str(CMD_STATE(sc)));
- old_ioreq_state = CMD_STATE(sc);
- /*
- * Any pending IO issued prior to reset is expected to be
- * in abts pending state, if not we need to set
- * FNIC_IOREQ_ABTS_PENDING to indicate the IO is abort pending.
- * When IO is completed, the IO will be handed over and
- * handled in this function.
- */
- CMD_STATE(sc) = FNIC_IOREQ_ABTS_PENDING;
+ /*
+ * Found IO that is still pending with firmware and
+ * belongs to the LUN that we are resetting
+ */
+ FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
+ "Found IO in %s on lun\n",
+ fnic_ioreq_state_to_str(CMD_STATE(sc)));

- BUG_ON(io_req->abts_done);
+ if (CMD_STATE(sc) == FNIC_IOREQ_ABTS_PENDING) {
+ spin_unlock_irqrestore(io_lock, flags);
+ return true;
+ }
+ if ((CMD_FLAGS(sc) & FNIC_DEVICE_RESET) &&
+ (!(CMD_FLAGS(sc) & FNIC_DEV_RST_ISSUED))) {
+ FNIC_SCSI_DBG(KERN_INFO, fnic->lport->host,
+ "%s dev rst not pending sc 0x%p\n", __func__,
+ sc);
+ spin_unlock_irqrestore(io_lock, flags);
+ return true;
+ }

- abt_tag = tag;
- if (CMD_FLAGS(sc) & FNIC_DEVICE_RESET) {
- abt_tag |= FNIC_TAG_DEV_RST;
- FNIC_SCSI_DBG(KERN_INFO, fnic->lport->host,
- "%s: dev rst sc 0x%p\n", __func__, sc);
- }
+ if (io_req->abts_done)
+ shost_printk(KERN_ERR, fnic->lport->host,
+ "%s: io_req->abts_done is set state is %s\n",
+ __func__, fnic_ioreq_state_to_str(CMD_STATE(sc)));
+ old_ioreq_state = CMD_STATE(sc);
+ /*
+ * Any pending IO issued prior to reset is expected to be
+ * in abts pending state, if not we need to set
+ * FNIC_IOREQ_ABTS_PENDING to indicate the IO is abort pending.
+ * When IO is completed, the IO will be handed over and
+ * handled in this function.
+ */
+ CMD_STATE(sc) = FNIC_IOREQ_ABTS_PENDING;

- CMD_ABTS_STATUS(sc) = FCPIO_INVALID_CODE;
- io_req->abts_done = &tm_done;
- spin_unlock_irqrestore(io_lock, flags);
+ BUG_ON(io_req->abts_done);

- /* Now queue the abort command to firmware */
- int_to_scsilun(sc->device->lun, &fc_lun);
+ if (CMD_FLAGS(sc) & FNIC_DEVICE_RESET) {
+ abt_tag |= FNIC_TAG_DEV_RST;
+ FNIC_SCSI_DBG(KERN_INFO, fnic->lport->host,
+ "%s: dev rst sc 0x%p\n", __func__, sc);
+ }

- if (fnic_queue_abort_io_req(fnic, abt_tag,
- FCPIO_ITMF_ABT_TASK_TERM,
- fc_lun.scsi_lun, io_req)) {
- spin_lock_irqsave(io_lock, flags);
- io_req = (struct fnic_io_req *)CMD_SP(sc);
- if (io_req)
- io_req->abts_done = NULL;
- if (CMD_STATE(sc) == FNIC_IOREQ_ABTS_PENDING)
- CMD_STATE(sc) = old_ioreq_state;
- spin_unlock_irqrestore(io_lock, flags);
- ret = 1;
- goto clean_pending_aborts_end;
- } else {
- spin_lock_irqsave(io_lock, flags);
- if (CMD_FLAGS(sc) & FNIC_DEVICE_RESET)
- CMD_FLAGS(sc) |= FNIC_DEV_RST_TERM_ISSUED;
- spin_unlock_irqrestore(io_lock, flags);
- }
- CMD_FLAGS(sc) |= FNIC_IO_INTERNAL_TERM_ISSUED;
+ CMD_ABTS_STATUS(sc) = FCPIO_INVALID_CODE;
+ io_req->abts_done = &tm_done;
+ spin_unlock_irqrestore(io_lock, flags);

- wait_for_completion_timeout(&tm_done,
- msecs_to_jiffies
- (fnic->config.ed_tov));
+ /* Now queue the abort command to firmware */
+ int_to_scsilun(sc->device->lun, &fc_lun);

- /* Recheck cmd state to check if it is now aborted */
+ if (fnic_queue_abort_io_req(fnic, abt_tag,
+ FCPIO_ITMF_ABT_TASK_TERM,
+ fc_lun.scsi_lun, io_req)) {
spin_lock_irqsave(io_lock, flags);
io_req = (struct fnic_io_req *)CMD_SP(sc);
- if (!io_req) {
- spin_unlock_irqrestore(io_lock, flags);
- CMD_FLAGS(sc) |= FNIC_IO_ABT_TERM_REQ_NULL;
- continue;
- }
+ if (io_req)
+ io_req->abts_done = NULL;
+ if (CMD_STATE(sc) == FNIC_IOREQ_ABTS_PENDING)
+ CMD_STATE(sc) = old_ioreq_state;
+ spin_unlock_irqrestore(io_lock, flags);
+ return false;
+ } else {
+ spin_lock_irqsave(io_lock, flags);
+ if (CMD_FLAGS(sc) & FNIC_DEVICE_RESET)
+ CMD_FLAGS(sc) |= FNIC_DEV_RST_TERM_ISSUED;
+ spin_unlock_irqrestore(io_lock, flags);
+ }
+ CMD_FLAGS(sc) |= FNIC_IO_INTERNAL_TERM_ISSUED;

- io_req->abts_done = NULL;
+ wait_for_completion_timeout(&tm_done, msecs_to_jiffies
+ (fnic->config.ed_tov));

- /* if abort is still pending with fw, fail */
- if (CMD_ABTS_STATUS(sc) == FCPIO_INVALID_CODE) {
- spin_unlock_irqrestore(io_lock, flags);
- CMD_FLAGS(sc) |= FNIC_IO_ABT_TERM_DONE;
- ret = 1;
- goto clean_pending_aborts_end;
- }
- CMD_STATE(sc) = FNIC_IOREQ_ABTS_COMPLETE;
+ /* Recheck cmd state to check if it is now aborted */
+ spin_lock_irqsave(io_lock, flags);
+ io_req = (struct fnic_io_req *)CMD_SP(sc);
+ if (!io_req) {
+ spin_unlock_irqrestore(io_lock, flags);
+ CMD_FLAGS(sc) |= FNIC_IO_ABT_TERM_REQ_NULL;
+ return true;
+ }

- /* original sc used for lr is handled by dev reset code */
- if (sc != lr_sc)
- CMD_SP(sc) = NULL;
+ io_req->abts_done = NULL;
+
+ /* if abort is still pending with fw, fail */
+ if (CMD_ABTS_STATUS(sc) == FCPIO_INVALID_CODE) {
spin_unlock_irqrestore(io_lock, flags);
+ CMD_FLAGS(sc) |= FNIC_IO_ABT_TERM_DONE;
+ iter_data->ret = FAILED;
+ return false;
+ }
+ CMD_STATE(sc) = FNIC_IOREQ_ABTS_COMPLETE;

- /* original sc used for lr is handled by dev reset code */
- if (sc != lr_sc) {
- fnic_release_ioreq_buf(fnic, io_req, sc);
- mempool_free(io_req, fnic->io_req_pool);
- }
+ /* original sc used for lr is handled by dev reset code */
+ CMD_SP(sc) = NULL;
+ spin_unlock_irqrestore(io_lock, flags);

- /*
- * Any IO is returned during reset, it needs to call scsi_done
- * to return the scsi_cmnd to upper layer.
- */
- if (sc->scsi_done) {
- /* Set result to let upper SCSI layer retry */
- sc->result = DID_RESET << 16;
- sc->scsi_done(sc);
- }
+ /* original sc used for lr is handled by dev reset code */
+ fnic_release_ioreq_buf(fnic, io_req, sc);
+ mempool_free(io_req, fnic->io_req_pool);
+
+ /*
+ * Any IO is returned during reset, it needs to call scsi_done
+ * to return the scsi_cmnd to upper layer.
+ */
+ if (sc->scsi_done) {
+ /* Set result to let upper SCSI layer retry */
+ sc->result = DID_RESET << 16;
+ sc->scsi_done(sc);
}
+ return true;
+}
+
+/*
+ * Clean up any pending aborts on the lun
+ * For each outstanding IO on this lun, whose abort is not completed by fw,
+ * issue a local abort. Wait for abort to complete. Return 0 if all commands
+ * successfully aborted, 1 otherwise
+ */
+static int fnic_clean_pending_aborts(struct fnic *fnic,
+ struct scsi_cmnd *lr_sc)

+{
+ int ret = SUCCESS;
+ struct fnic_pending_aborts_iter_data iter_data = {
+ .fnic = fnic,
+ .lun_dev = lr_sc->device,
+ .ret = SUCCESS,
+ };
+
+ scsi_host_tagset_busy_iter(fnic->lport->host,
+ fnic_pending_aborts_iter, &iter_data);
+ if (iter_data.ret == FAILED) {
+ ret = iter_data.ret;
+ goto clean_pending_aborts_end;
+ }
schedule_timeout(msecs_to_jiffies(2 * fnic->config.ed_tov));

/* walk again to check, if IOs are still pending in fw */
@@ -2287,38 +2296,6 @@ static int fnic_clean_pending_aborts(struct fnic *fnic,
return ret;
}

-/**
- * fnic_scsi_host_start_tag
- * Allocates tagid from host's tag list
- **/
-static inline int
-fnic_scsi_host_start_tag(struct fnic *fnic, struct scsi_cmnd *sc)
-{
- struct request_queue *q = sc->request->q;
- struct request *dummy;
-
- dummy = blk_mq_alloc_request(q, REQ_OP_WRITE, BLK_MQ_REQ_NOWAIT);
- if (IS_ERR(dummy))
- return SCSI_NO_TAG;
-
- sc->tag = sc->request->tag = dummy->tag;
- sc->host_scribble = (unsigned char *)dummy;
-
- return dummy->tag;
-}
-
-/**
- * fnic_scsi_host_end_tag
- * frees tag allocated by fnic_scsi_host_start_tag.
- **/
-static inline void
-fnic_scsi_host_end_tag(struct fnic *fnic, struct scsi_cmnd *sc)
-{
- struct request *dummy = (struct request *)sc->host_scribble;
-
- blk_mq_free_request(dummy);
-}
-
/*
* SCSI Eh thread issues a Lun Reset when one or more commands on a LUN
* fail to get aborted. It calls driver's eh_device_reset with a SCSI command
@@ -2340,8 +2317,8 @@ 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;
+ struct scsi_cmnd *reset_sc = NULL;
+ struct Scsi_Host *shost = sc->device->host;

/* Wait for rport to unblock */
fc_block_scsi_eh(sc);
@@ -2369,24 +2346,15 @@ int fnic_device_reset(struct scsi_cmnd *sc)
goto fnic_device_reset_end;
}

- CMD_FLAGS(sc) = FNIC_DEVICE_RESET;
- /* Allocate tag if not present */
+ reset_sc = scsi_get_reserved_cmd(shost);
+ if (unlikely(!reset_sc))
+ goto fnic_device_reset_end;

- tag = sc->request->tag;
- if (unlikely(tag < 0)) {
- /*
- * Really should fix the midlayer to pass in a proper
- * request for ioctls...
- */
- 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;
- }
- io_lock = fnic_io_lock_hash(fnic, sc);
+ CMD_FLAGS(reset_sc) = FNIC_DEVICE_RESET;
+ tag = reset_sc->request->tag;
+ io_lock = fnic_io_lock_hash(fnic, reset_sc);
spin_lock_irqsave(io_lock, flags);
- io_req = (struct fnic_io_req *)CMD_SP(sc);
+ io_req = (struct fnic_io_req *)CMD_SP(reset_sc);

/*
* If there is a io_req attached to this command, then use it,
@@ -2400,11 +2368,11 @@ int fnic_device_reset(struct scsi_cmnd *sc)
}
memset(io_req, 0, sizeof(*io_req));
io_req->port_id = rport->port_id;
- CMD_SP(sc) = (char *)io_req;
+ CMD_SP(reset_sc) = (char *)io_req;
}
io_req->dr_done = &tm_done;
- CMD_STATE(sc) = FNIC_IOREQ_CMD_PENDING;
- CMD_LR_STATUS(sc) = FCPIO_INVALID_CODE;
+ CMD_STATE(reset_sc) = FNIC_IOREQ_CMD_PENDING;
+ CMD_LR_STATUS(reset_sc) = FCPIO_INVALID_CODE;
spin_unlock_irqrestore(io_lock, flags);

FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host, "TAG %x\n", tag);
@@ -2413,15 +2381,15 @@ int fnic_device_reset(struct scsi_cmnd *sc)
* issue the device reset, if enqueue failed, clean up the ioreq
* and break assoc with scsi cmd
*/
- if (fnic_queue_dr_io_req(fnic, sc, io_req)) {
+ if (fnic_queue_dr_io_req(fnic, reset_sc, io_req)) {
spin_lock_irqsave(io_lock, flags);
- io_req = (struct fnic_io_req *)CMD_SP(sc);
+ io_req = (struct fnic_io_req *)CMD_SP(reset_sc);
if (io_req)
io_req->dr_done = NULL;
goto fnic_device_reset_clean;
}
spin_lock_irqsave(io_lock, flags);
- CMD_FLAGS(sc) |= FNIC_DEV_RST_ISSUED;
+ CMD_FLAGS(reset_sc) |= FNIC_DEV_RST_ISSUED;
spin_unlock_irqrestore(io_lock, flags);

/*
@@ -2432,16 +2400,16 @@ int fnic_device_reset(struct scsi_cmnd *sc)
msecs_to_jiffies(FNIC_LUN_RESET_TIMEOUT));

spin_lock_irqsave(io_lock, flags);
- io_req = (struct fnic_io_req *)CMD_SP(sc);
+ io_req = (struct fnic_io_req *)CMD_SP(reset_sc);
if (!io_req) {
spin_unlock_irqrestore(io_lock, flags);
FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
- "io_req is null tag 0x%x sc 0x%p\n", tag, sc);
+ "io_req is null tag 0x%x sc 0x%p\n", tag, reset_sc);
goto fnic_device_reset_end;
}
io_req->dr_done = NULL;

- status = CMD_LR_STATUS(sc);
+ status = CMD_LR_STATUS(reset_sc);

/*
* If lun reset not completed, bail out with failed. io_req
@@ -2451,7 +2419,7 @@ int fnic_device_reset(struct scsi_cmnd *sc)
atomic64_inc(&reset_stats->device_reset_timeouts);
FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
"Device reset timed out\n");
- CMD_FLAGS(sc) |= FNIC_DEV_RST_TIMED_OUT;
+ CMD_FLAGS(reset_sc) |= FNIC_DEV_RST_TIMED_OUT;
spin_unlock_irqrestore(io_lock, flags);
int_to_scsilun(sc->device->lun, &fc_lun);
/*
@@ -2460,7 +2428,7 @@ int fnic_device_reset(struct scsi_cmnd *sc)
*/
while (1) {
spin_lock_irqsave(io_lock, flags);
- if (CMD_FLAGS(sc) & FNIC_DEV_RST_TERM_ISSUED) {
+ if (CMD_FLAGS(reset_sc) & FNIC_DEV_RST_TERM_ISSUED) {
spin_unlock_irqrestore(io_lock, flags);
break;
}
@@ -2473,8 +2441,8 @@ int fnic_device_reset(struct scsi_cmnd *sc)
msecs_to_jiffies(FNIC_ABT_TERM_DELAY_TIMEOUT));
} else {
spin_lock_irqsave(io_lock, flags);
- CMD_FLAGS(sc) |= FNIC_DEV_RST_TERM_ISSUED;
- CMD_STATE(sc) = FNIC_IOREQ_ABTS_PENDING;
+ CMD_FLAGS(reset_sc) |= FNIC_DEV_RST_TERM_ISSUED;
+ CMD_STATE(reset_sc) = FNIC_IOREQ_ABTS_PENDING;
io_req->abts_done = &tm_done;
spin_unlock_irqrestore(io_lock, flags);
FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
@@ -2491,7 +2459,7 @@ int fnic_device_reset(struct scsi_cmnd *sc)
msecs_to_jiffies(FNIC_LUN_RESET_TIMEOUT));
break;
} else {
- io_req = (struct fnic_io_req *)CMD_SP(sc);
+ io_req = (struct fnic_io_req *)CMD_SP(reset_sc);
io_req->abts_done = NULL;
goto fnic_device_reset_clean;
}
@@ -2506,7 +2474,7 @@ int fnic_device_reset(struct scsi_cmnd *sc)
FNIC_SCSI_DBG(KERN_DEBUG,
fnic->lport->host,
"Device reset completed - failed\n");
- io_req = (struct fnic_io_req *)CMD_SP(sc);
+ io_req = (struct fnic_io_req *)CMD_SP(reset_sc);
goto fnic_device_reset_clean;
}

@@ -2517,7 +2485,7 @@ 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, reset_sc)) {
spin_lock_irqsave(io_lock, flags);
io_req = (struct fnic_io_req *)CMD_SP(sc);
FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
@@ -2528,35 +2496,34 @@ int fnic_device_reset(struct scsi_cmnd *sc)

/* Clean lun reset command */
spin_lock_irqsave(io_lock, flags);
- io_req = (struct fnic_io_req *)CMD_SP(sc);
+ io_req = (struct fnic_io_req *)CMD_SP(reset_sc);
if (io_req)
/* Completed, and successful */
ret = SUCCESS;

fnic_device_reset_clean:
if (io_req)
- CMD_SP(sc) = NULL;
+ CMD_SP(reset_sc) = NULL;

spin_unlock_irqrestore(io_lock, flags);

if (io_req) {
start_time = io_req->start_time;
- fnic_release_ioreq_buf(fnic, io_req, sc);
+ fnic_release_ioreq_buf(fnic, io_req, reset_sc);
mempool_free(io_req, fnic->io_req_pool);
}

fnic_device_reset_end:
- FNIC_TRACE(fnic_device_reset, sc->device->host->host_no,
- sc->request->tag, sc,
+ FNIC_TRACE(fnic_device_reset, reset_sc->device->host->host_no,
+ reset_sc->request->tag, reset_sc,
jiffies_to_msecs(jiffies - start_time),
- 0, ((u64)sc->cmnd[0] << 32 |
+ 0, ((u64)reset_sc->cmnd[0] << 32 |
(u64)sc->cmnd[2] << 24 | (u64)sc->cmnd[3] << 16 |
(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);
+ scsi_put_reserved_cmd(reset_sc);

FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
"Returning from device reset %s\n",
--
2.17.1