Hi Hannes,
Thank you for reviewing the patch. Please find responses inline.
I will incorporate the comments and suggestions in next patch submittal.
On 25/03/15 4:31 pm, "Hannes Reinecke" <hare@xxxxxxx> wrote:
>Hi Narsimhulu,
>
>On 03/11/2015 06:01 PM, Narsimhulu Musini wrote:
>> snic_scsi.c contains scsi handling, includes queuing io, abort, lun
>>reset,
>> and host reset. Also it handles asynchronous event notifications from
>>FW.
>>
>> v2
>> Changed queuecommand to lock-free version.
>> Converted custom error codes to standard error codes.
>>
>> Signed-off-by: Narsimhulu Musini <nmusini@xxxxxxxxx>
>> Signed-off-by: Sesidhar Baddela <sebaddel@xxxxxxxxx>
>> ---
>> drivers/scsi/snic/snic_scsi.c | 2631
>>+++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 2631 insertions(+)
>> create mode 100644 drivers/scsi/snic/snic_scsi.c
>>
>> diff --git a/drivers/scsi/snic/snic_scsi.c
>>b/drivers/scsi/snic/snic_scsi.c
>> new file mode 100644
>> index 0000000..f82ff02
>> --- /dev/null
>> +++ b/drivers/scsi/snic/snic_scsi.c
>> @@ -0,0 +1,2631 @@
>> +/*
>> + * Copyright 2014 Cisco Systems, Inc. All rights reserved.
>> + *
>> + * This program is free software; you may redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; version 2 of the License.
>> + *
>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
>> + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
>> + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
>> + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
>> + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
>> + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
>> + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
>> + * SOFTWARE.
>> + */
>> +
>> +#include <linux/mempool.h>
>> +#include <linux/errno.h>
>> +#include <linux/init.h>
>> +#include <linux/workqueue.h>
>> +#include <linux/pci.h>
>> +#include <linux/spinlock.h>
>> +#include <linux/delay.h>
>> +#include <linux/gfp.h>
>> +#include <scsi/scsi.h>
>> +#include <scsi/scsi_host.h>
>> +#include <scsi/scsi_device.h>
>> +#include <scsi/scsi_cmnd.h>
>> +#include <scsi/scsi_tcq.h>
>> +#include <scsi/scsi_dbg.h>
>> +
>> +#include "snic_io.h"
>> +#include "snic.h"
>> +#include "snic_os.h"
>> +
>> +const char *snic_state_str[] = {
>> + [SNIC_INIT] = "SNIC_INIT",
>> + [SNIC_ERROR] = "SNIC_ERROR",
>> + [SNIC_ONLINE] = "SNIC_ONLINE",
>> + [SNIC_OFFLINE] = "SNIC_OFFLINE",
>> + [SNIC_FWRESET] = "SNIC_FWRESET",
>> +};
>> +
>> +static const char * const snic_req_state_str[] = {
>> + [SNIC_IOREQ_NOT_INITED] = "SNIC_IOREQ_NOT_INITED",
>> + [SNIC_IOREQ_PENDING] = "SNIC_IOREQ_PENDING",
>> + [SNIC_IOREQ_ABTS_PENDING] = "SNIC_IOREQ_ABTS_PENDING",
>> + [SNIC_IOREQ_ABTS_COMPLETE] = "SNIC_IOREQ_ABTS_COMPELTE",
>> + [SNIC_IOREQ_LR_PENDING] = "SNIC_IOREQ_LR_PENDING",
>> + [SNIC_IOREQ_LR_COMPLETE] = "SNIC_IOREQ_LR_COMPELTE",
>> + [SNIC_IOREQ_COMPLETE] = "SNIC_IOREQ_CMD_COMPELTE",
>> +};
>> +
>> +/* snic cmd status strings */
>> +static const char * const snic_io_status_str[] = {
>> + [SNIC_STAT_IO_SUCCESS] = "SNIC_STAT_IO_SUCCESS", /* 0x0 */
>> + [SNIC_STAT_INVALID_HDR] = "SNIC_STAT_INVALID_HDR",
>> + [SNIC_STAT_OUT_OF_RES] = "SNIC_STAT_OUT_OF_RES",
>> + [SNIC_STAT_INVALID_PARM] = "SNIC_STAT_INVALID_PARM",
>> + [SNIC_STAT_REQ_NOT_SUP] = "SNIC_STAT_REQ_NOT_SUP",
>> + [SNIC_STAT_IO_NOT_FOUND] = "SNIC_STAT_IO_NOT_FOUND",
>> + [SNIC_STAT_ABORTED] = "SNIC_STAT_ABORTED",
>> + [SNIC_STAT_TIMEOUT] = "SNIC_STAT_TIMEOUT",
>> + [SNIC_STAT_SGL_INVALID] = "SNIC_STAT_SGL_INVALID",
>> + [SNIC_STAT_DATA_CNT_MISMATCH] = "SNIC_STAT_DATA_CNT_MISMATCH",
>> + [SNIC_STAT_FW_ERR] = "SNIC_STAT_FW_ERR",
>> + [SNIC_STAT_ITMF_REJECT] = "SNIC_STAT_ITMF_REJECT",
>> + [SNIC_STAT_ITMF_FAIL] = "SNIC_STAT_ITMF_FAIL",
>> + [SNIC_STAT_ITMF_INCORRECT_LUN] = "SNIC_STAT_ITMF_INCORRECT_LUN",
>> + [SNIC_STAT_CMND_REJECT] = "SNIC_STAT_CMND_REJECT",
>> + [SNIC_STAT_DEV_OFFLINE] = "SNIC_STAT_DEV_OFFLINE",
>> + [SNIC_STAT_NO_BOOTLUN] = "SNIC_STAT_NO_BOOTLUN",
>> + [SNIC_STAT_SCSI_ERR] = "SNIC_STAT_SCSI_ERR",
>> + [SNIC_STAT_NOT_READY] = "SNIC_STAT_NOT_READY",
>> + [SNIC_STAT_FATAL_ERROR] = "SNIC_STAT_FATAL_ERROR",
>> +};
>> +
>> +static void snic_scsi_cleanup(struct snic *, int);
>> +
>> +const char *
>> +snic_state_to_str(unsigned int state)
>> +{
>> + if (state >= ARRAY_SIZE(snic_state_str) || !snic_state_str[state])
>> + return "Unknown";
>> +
>> + return snic_state_str[state];
>> +}
>> +
>> +static const char *
>> +snic_io_status_to_str(unsigned int state)
>> +{
>> + if ((state >= ARRAY_SIZE(snic_io_status_str)) ||
>> + (!snic_io_status_str[state]))
>> + return "Unknown";
>> +
>> + return snic_io_status_str[state];
>> +}
>> +
>> +static const char *
>> +snic_ioreq_state_to_str(unsigned int state)
>> +{
>> + if (state >= ARRAY_SIZE(snic_req_state_str) ||
>> + !snic_req_state_str[state])
>> + return "Unknown";
>> +
>> + return snic_req_state_str[state];
>> +}
>> +
>> +static inline spinlock_t *
>> +snic_io_lock_hash(struct snic *snic, struct scsi_cmnd *sc)
>> +{
>> + u32 hash = snic_cmd_tag(sc) & (SNIC_IO_LOCKS - 1);
>> +
>> + return &snic->io_req_lock[hash];
>> +}
>> +
>> +static inline spinlock_t *
>> +snic_io_lock_tag(struct snic *snic, int tag)
>> +{
>> + return &snic->io_req_lock[tag & (SNIC_IO_LOCKS - 1)];
>> +}
>> +
>> +/* snic_release_req_buf : Releases snic_req_info */
>> +static void
>> +snic_release_req_buf(struct snic *snic,
>> + struct snic_req_info *rqi,
>> + struct scsi_cmnd *sc)
>> +{
>> + struct snic_host_req *req = rqi_to_req(rqi);
>> +
>> + /* Freeing cmd without marking completion, not okay */
>> + SNIC_BUG_ON(!((CMD_STATE(sc) == SNIC_IOREQ_COMPLETE) ||
>> + (CMD_STATE(sc) == SNIC_IOREQ_ABTS_COMPLETE) ||
>> + (CMD_FLAGS(sc) & SNIC_DEV_RST_NOTSUP) ||
>> + (CMD_FLAGS(sc) & SNIC_IO_INTERNAL_TERM_ISSUED) ||
>> + (CMD_FLAGS(sc) & SNIC_DEV_RST_TERM_ISSUED) ||
>> + (CMD_FLAGS(sc) & SNIC_SCSI_CLEANUP) ||
>> + (CMD_STATE(sc) == SNIC_IOREQ_LR_COMPLETE)));
>> +
>> + SNIC_SCSI_DBG(snic->shost,
>> + "Rel_req:sc %p:tag %x:rqi %p:ioreq %p:abt %p:dr %p: state
>>%s:flags 0x%x\n",
>> + sc, snic_cmd_tag(sc), rqi, rqi->req, rqi->abort_req,
>> + rqi->dr_req, snic_ioreq_state_to_str(CMD_STATE(sc)),
>> + CMD_FLAGS(sc));
>> +
>> + if (req->u.icmnd.sense_addr)
>> + pci_unmap_single(snic->pdev,
>> + req->u.icmnd.sense_addr,
>> + SCSI_SENSE_BUFFERSIZE,
>> + PCI_DMA_FROMDEVICE);
>> +
>> + scsi_dma_unmap(sc);
>> +
>> + snic_req_free(snic, rqi);
>> +} /* end of snic_release_req_buf */
>> +
>> +/*
>> + * snic_queue_icmnd_req : Queues snic_icmnd request
>> + */
>> +static int
>> +snic_queue_icmnd_req(struct snic *snic,
>> + struct snic_req_info *rqi,
>> + struct scsi_cmnd *sc,
>> + int sg_cnt)
>> +{
>> + struct scatterlist *sg;
>> + struct snic_sg_desc *sgd;
>> + dma_addr_t pa = 0;
>> + struct scsi_lun lun;
>> + int flags = 0;
>> + int ret = 0;
>> + unsigned int i;
>> +
>> + if (sg_cnt) {
>> + flags = SNIC_ICMND_ESGL;
>> + sgd = (struct snic_sg_desc *) req_to_sgl(rqi->req);
>> +
>> + for_each_sg(scsi_sglist(sc), sg, sg_cnt, i) {
>> + sgd->addr = cpu_to_le64(sg_dma_address(sg));
>> + sgd->len = cpu_to_le32(sg_dma_len(sg));
>> + sgd->_resvd = 0;
>> + sgd++;
>> + }
>> + }
>> +
>> + pa = pci_map_single(snic->pdev,
>> + sc->sense_buffer,
>> + SCSI_SENSE_BUFFERSIZE,
>> + PCI_DMA_FROMDEVICE);
>> +
>> + if (pci_dma_mapping_error(snic->pdev, pa)) {
>> + SNIC_HOST_ERR(snic->shost,
>> + "QIcmnd:PCI Map Failed for sns buf %p tag %x\n",
>> + sc->sense_buffer, snic_cmd_tag(sc));
>> + ret = -ENOMEM;
>> +
>> + return ret;
>> + }
>> +
>> + int_to_scsilun(sc->device->lun, &lun);
>> + if (sc->sc_data_direction == DMA_FROM_DEVICE)
>> + flags |= SNIC_ICMND_RD;
>> + if (sc->sc_data_direction == DMA_TO_DEVICE)
>> + flags |= SNIC_ICMND_WR;
>> +
>> + /* Initialize icmnd */
>> + snic_icmnd_init(rqi->req,
>> + snic_cmd_tag(sc),
>> + snic->config.hid, /* hid */
>> + (u64)rqi,
>> + flags, /* command flags */
>> + rqi->tgt_id,
>> + lun.scsi_lun,
>> + sc->cmnd,
>> + sc->cmd_len,
>> + scsi_bufflen(sc),
>> + sg_cnt,
>> + (u64)req_to_sgl(rqi->req),
>> + pa, /* sense buffer pa */
>> + SCSI_SENSE_BUFFERSIZE);
>> +
>> + ret = snic_queue_wq_desc(snic, rqi->req, rqi->req_len);
>> + if (ret)
>> + SNIC_HOST_ERR(snic->shost,
>> + "QIcmnd: Queuing Icmnd Failed. ret = %d\n",
>> + ret);
>> +
>> + return ret;
>> +} /* end of snic_queue_icmnd_req */
>> +
>> +/*
>> + * snic_issue_scsi_req : Prepares IO request and Issues to FW.
>> + */
>> +static int
>> +snic_issue_scsi_req(struct snic *snic,
>> + struct snic_tgt *tgt,
>> + struct scsi_cmnd *sc)
>> +{
>> + struct snic_req_info *rqi = NULL;
>> + int sg_cnt = 0;
>> + int ret = 0;
>> + u32 tag = snic_cmd_tag(sc);
>> + u64 cmd_trc = 0, cmd_st_flags = 0;
>> + spinlock_t *io_lock = NULL;
>> + unsigned long flags;
>> +
>> + CMD_STATE(sc) = SNIC_IOREQ_NOT_INITED;
>> + CMD_FLAGS(sc) = SNIC_NO_FLAGS;
>> + sg_cnt = scsi_dma_map(sc);
>> + if (sg_cnt < 0) {
>> + SNIC_TRC((u16)snic->shost->host_no, tag, (u64)sc, 0,
>> + sc->cmnd[0], sg_cnt, CMD_STATE(sc));
>> +
>> + SNIC_HOST_ERR(snic->shost, "issue_sc:Failed to map SG List.\n");
>> + ret = -ENOMEM;
>> +
>> + goto issue_sc_end;
>> + }
>> +
>> + rqi = snic_req_init(snic, sg_cnt);
>> + if (!rqi) {
>> + scsi_dma_unmap(sc);
>> + ret = -ENOMEM;
>> +
>> + goto issue_sc_end;
>> + }
>> +
>> + rqi->tgt_id = tgt->id;
>> + rqi->sc = sc;
>> +
>> + CMD_STATE(sc) = SNIC_IOREQ_PENDING;
>> + CMD_SP(sc) = (char *) rqi;
>> + cmd_trc = SNIC_TRC_CMD(sc);
>> + CMD_FLAGS(sc) |= (SNIC_IO_INITIALIZED | SNIC_IO_ISSUED);
>> + cmd_st_flags = SNIC_TRC_CMD_STATE_FLAGS(sc);
>> + io_lock = snic_io_lock_hash(snic, sc);
>> +
>> + /* create wq desc and enqueue it */
>> + ret = snic_queue_icmnd_req(snic, rqi, sc, sg_cnt);
>> + if (ret) {
>> + SNIC_HOST_ERR(snic->shost,
>> + "issue_sc: icmnd qing Failed for sc %p, err %d\n",
>> + sc, ret);
>> +
>> + spin_lock_irqsave(io_lock, flags);
>> + rqi = (struct snic_req_info *) CMD_SP(sc);
>> + CMD_SP(sc) = NULL;
>> + CMD_STATE(sc) = SNIC_IOREQ_COMPLETE;
>> + CMD_FLAGS(sc) &= ~SNIC_IO_ISSUED; /* turn off the flag */
>> + spin_unlock_irqrestore(io_lock, flags);
>> +
>> + if (rqi)
>> + snic_release_req_buf(snic, rqi, sc);
>> +
>> + SNIC_TRC(snic->shost->host_no, tag, (u64)sc, 0, 0, 0,
>> + SNIC_TRC_CMD_STATE_FLAGS(sc));
>> + } else {
>> + u32 io_sz = scsi_bufflen(sc) >> 9;
>> + u32 qtime = jiffies - rqi->start_time;
>> + struct snic_io_stats *iostats = &snic->s_stats.io;
>> +
>> + if (io_sz > atomic64_read(&iostats->max_io_sz))
>> + atomic64_set(&iostats->max_io_sz, io_sz);
>> +
>> + if (qtime > atomic64_read(&iostats->max_qtime))
>> + atomic64_set(&iostats->max_qtime, qtime);
>> +
>> + SNIC_SCSI_DBG(snic->shost,
>> + "issue_sc:sc %p, tag %d queued to WQ.\n",
>> + sc, tag);
>> +
>> + SNIC_TRC(snic->shost->host_no, tag, (u64)sc, (u64)rqi, sg_cnt,
>> + cmd_trc, cmd_st_flags);
>> + }
>> +
>> +issue_sc_end:
>> +
>> + return ret;
>> +} /* end of snic_issue_scsi_req */
>> +
>> +
>> +/*
>> + * snic_queuecommand
>> + * Routine to send a scsi cdb to LLD
>> + * Called with host_lock held and interrupts disabled
>> + */
>> +int
>> +snic_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *sc)
>> +{
>> + struct snic_tgt *tgt = NULL;
>> + struct snic *snic = shost_priv(shost);
>> + int ret;
>> +
>> + tgt = starget_to_tgt(scsi_target(sc->device));
>> + ret = snic_tgt_chkready(tgt);
>> + if (ret) {
>> + SNIC_HOST_ERR(shost, "Tgt %p id %d Not Ready.\n", tgt, tgt->id);
>> + atomic64_inc(&snic->s_stats.misc.tgt_not_rdy);
>> + sc->result = ret;
>> + sc->scsi_done(sc);
>> +
>> + return 0;
>> + }
>> +
>> + if (snic_get_state(snic) != SNIC_ONLINE) {
>> + SNIC_HOST_ERR(shost, "snic state is %s\n",
>> + snic_state_str[snic_get_state(snic)]);
>> +
>> + return SCSI_MLQUEUE_HOST_BUSY;
>> + }
>> + atomic_inc(&snic->ios_inflight);
>> +
>> + SNIC_SCSI_DBG(shost, "sc %p Tag %d (sc %0x) lun %lld in snic_qcmd\n",
>> + sc, snic_cmd_tag(sc), sc->cmnd[0], sc->device->lun);
>> +
>> +#ifdef SNIC_DEBUG
>> + scsi_print_command(sc);
>> +#endif
>> +
>> + ret = snic_issue_scsi_req(snic, tgt, sc);
>> + if (ret) {
>> + SNIC_HOST_ERR(shost, "Failed to Q, Scsi Req w/ err %d.\n", ret);
>> + ret = SCSI_MLQUEUE_HOST_BUSY;
>> + } else
>> + snic_stats_update_active_ios(&snic->s_stats);
>> +
>> + atomic_dec(&snic->ios_inflight);
>> +
>> + return ret;
>> +} /* end of snic_queuecommand */
>> +
>> +/*
>> + * snic_process_abts_pending_state:
>> + * caller should hold IO lock
>> + */
>> +static void
>> +snic_proc_tmreq_pending_state(struct snic *snic,
>> + struct scsi_cmnd *sc,
>> + u8 cmpl_status)
>> +{
>> + int state = CMD_STATE(sc);
>> +
>> + if (state == SNIC_IOREQ_ABTS_PENDING)
>> + CMD_FLAGS(sc) |= SNIC_IO_ABTS_PENDING;
>> + else if (state == SNIC_IOREQ_LR_PENDING)
>> + CMD_FLAGS(sc) |= SNIC_DEV_RST_PENDING;
>> + else
>> + SNIC_BUG_ON(1);
>> +
>> + switch (cmpl_status) {
>> + case SNIC_STAT_IO_SUCCESS:
>> + CMD_FLAGS(sc) |= SNIC_IO_DONE;
>> + break;
>> +
>> + case SNIC_STAT_ABORTED:
>> + CMD_FLAGS(sc) |= SNIC_IO_ABORTED;
>> + break;
>> +
>> + default:
>> + SNIC_BUG_ON(1);
>> + }
>> +}
>> +
>> +/*
>> + * snic_process_io_failed_state:
>> + * Processes IO's error states
>> + */
>> +static void
>> +snic_process_io_failed_state(struct snic *snic,
>> + struct snic_icmnd_cmpl *icmnd_cmpl,
>> + struct scsi_cmnd *sc,
>> + u8 cmpl_stat)
>> +{
>> + int res = 0;
>> +
>> + switch (cmpl_stat) {
>> + case SNIC_STAT_TIMEOUT: /* Req was timedout */
>> + atomic64_inc(&snic->s_stats.misc.io_tmo);
>> + res = DID_TIME_OUT;
>> + break;
>> +
>> + case SNIC_STAT_ABORTED: /* Req was aborted */
>> + atomic64_inc(&snic->s_stats.misc.io_aborted);
>> + res = DID_ERROR;
>> + break;
>> +
>> + case SNIC_STAT_DATA_CNT_MISMATCH:/* Recv/Sent more/less data than exp
>>*/
>> + atomic64_inc(&snic->s_stats.misc.data_cnt_mismat);
>> + scsi_set_resid(sc, icmnd_cmpl->resid);
>> + res = DID_ERROR;
>> + break;
>> +
>> + case SNIC_STAT_OUT_OF_RES: /* Out of resources to complete request */
>> + atomic64_inc(&snic->s_stats.fw.out_of_res);
>> + res = DID_REQUEUE;
>> + break;
>> +
>> + case SNIC_STAT_IO_NOT_FOUND: /* Requested I/O was not found */
>> + atomic64_inc(&snic->s_stats.io.io_not_found);
>> + res = DID_ERROR;
>> + break;
>> +
>> + case SNIC_STAT_SGL_INVALID: /* Req was aborted to due to sgl error*/
>> + atomic64_inc(&snic->s_stats.misc.sgl_inval);
>> + res = DID_ERROR;
>> + break;
>> +
>> + case SNIC_STAT_FW_ERR: /* Req terminated due to FW Error */
>> + atomic64_inc(&snic->s_stats.fw.io_errs);
>> + res = DID_ERROR;
>> + break;
>> +
>> + case SNIC_STAT_SCSI_ERR: /* FW hits SCSI Error */
>> + atomic64_inc(&snic->s_stats.fw.scsi_errs);
>> + res = DID_ERROR;
>> + break;
>> +
>> + case SNIC_STAT_INVALID_HDR: /* Hdr contains invalid data */
>> + case SNIC_STAT_INVALID_PARM: /* Some param in req is invalid */
>> + case SNIC_STAT_REQ_NOT_SUP: /* Req type is not supported */
>> + case SNIC_STAT_CMND_REJECT: /* Req rejected */
>> + case SNIC_STAT_DEV_OFFLINE: /* Device offline */
>> + case SNIC_STAT_NOT_READY: /* XPT yet to initialize */
>> + case SNIC_STAT_FATAL_ERROR: /* XPT Error */
>> + default:
>> + SNIC_SCSI_DBG(snic->shost,
>> + "Invalid Hdr/Param or Req Not Supported or Cmnd Rejected or
>>Device Offline. or Unknown\n");
>> + res = DID_ERROR;
>> + break;
>> + }
>> +
>> + SNIC_HOST_ERR(snic->shost, "fw returns failed status %s flags 0x%x\n",
>> + snic_io_status_to_str(cmpl_stat), CMD_FLAGS(sc));
>> +
>> + /* Set sc->result */
>> + sc->result = (res << 16) | icmnd_cmpl->scsi_status;
>> +} /* end of snic_process_io_failed_state */
>> +
>> +/*
>> + * snic_tmreq_pending : is task management in progress.
>> + */
>> +static int
>> +snic_tmreq_pending(struct scsi_cmnd *sc)
>> +{
>> + int state = CMD_STATE(sc);
>> +
>> + return ((state == SNIC_IOREQ_ABTS_PENDING) ||
>> + (state == SNIC_IOREQ_LR_PENDING));
>> +}
>> +
>> +/*
>> + * snic_process_icmnd_cmpl_status:
>> + * Caller should hold io_lock
>> + */
>> +static int
>> +snic_process_icmnd_cmpl_status(struct snic *snic,
>> + struct snic_icmnd_cmpl *icmnd_cmpl,
>> + u8 cmpl_stat,
>> + struct scsi_cmnd *sc)
>> +{
>> + u8 scsi_stat = icmnd_cmpl->scsi_status;
>> + u64 xfer_len = 0;
>> + int ret = 0;
>> +
>> + /* Mark the IO as complete */
>> + CMD_STATE(sc) = SNIC_IOREQ_COMPLETE;
>> +
>> + if (likely(cmpl_stat == SNIC_STAT_IO_SUCCESS)) {
>> + sc->result = (DID_OK << 16) | scsi_stat;
>> +
>> + xfer_len = scsi_bufflen(sc);
>> +
>> + /* Update SCSI Cmd with resid value */
>> + scsi_set_resid(sc, icmnd_cmpl->resid);
>> +
>> + if (icmnd_cmpl->flags & SNIC_ICMND_CMPL_UNDR_RUN) {
>> + xfer_len -= icmnd_cmpl->resid;
>> + atomic64_inc(&snic->s_stats.misc.io_under_run);
>> + }
>> +
>> + if (icmnd_cmpl->scsi_status == SAM_STAT_TASK_SET_FULL)
>> + atomic64_inc(&snic->s_stats.misc.qfull);
>> +
>> + ret = 0;
>> + } else {
>> + snic_process_io_failed_state(snic, icmnd_cmpl, sc, cmpl_stat);
>> + atomic64_inc(&snic->s_stats.io.fail);
>> + SNIC_HOST_ERR(snic->shost,
>> + "icmnd_cmpl: IO Failed : Hdr Status %s flags 0x%x\n",
>> + snic_io_status_to_str(cmpl_stat), CMD_FLAGS(sc));
>> + ret = 1;
>> + }
>> +
>> + return ret;
>> +} /* end of snic_process_icmnd_cmpl_status */
>> +
>> +
>> +/*
>> + * snic_icmnd_cmpl_handler
>> + * Routine to handle icmnd completions
>> + */
>> +static void
>> +snic_icmnd_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
>> +{
>> + u8 typ, hdr_stat;
>> + u32 cmnd_id, hid;
>> + u64 ctx;
>> + struct scsi_cmnd *sc = NULL;
>> + struct snic_icmnd_cmpl *icmnd_cmpl = NULL;
>> + struct snic_host_req *req = NULL;
>> + struct snic_req_info *rqi = NULL;
>> + unsigned long flags, start_time;
>> + spinlock_t *io_lock;
>> + u8 sc_stat = 0;
>> +
>> + snic_io_hdr_dec(&fwreq->hdr, &typ, &hdr_stat, &cmnd_id, &hid, &ctx);
>> + icmnd_cmpl = &fwreq->u.icmnd_cmpl;
>> + sc_stat = icmnd_cmpl->scsi_status;
>> +
>> + SNIC_SCSI_DBG(snic->shost,
>> + "Icmnd_cmpl: type = %x, hdr_stat = %x, cmnd_id = %x, hid =
>>%x,i ctx = %llx\n",
>> + typ, hdr_stat, cmnd_id, hid, ctx);
>> +
>> + if (cmnd_id >= snic->max_tag_id) {
>> + SNIC_HOST_ERR(snic->shost,
>> + "Icmnd_cmpl:Tag Error:Out of Range Tag %d, hdr status = %s\n",
>> + cmnd_id, snic_io_status_to_str(hdr_stat));
>> + return;
>> + }
>> +
>> + sc = scsi_host_find_tag(snic->shost, cmnd_id);
>> + WARN_ON_ONCE(!sc);
>> +
>> + if (!sc) {
>> + atomic64_inc(&snic->s_stats.io.sc_null);
>> + SNIC_HOST_ERR(snic->shost,
>> + "Icmnd_cmpl: Scsi Cmnd Not found, sc = NULL Hdr Status = %s
>>tag = 0x%x fwreq = 0x%p\n",
>> + snic_io_status_to_str(hdr_stat),
>> + cmnd_id,
>> + fwreq);
>> +
>> + SNIC_TRC(snic->shost->host_no, cmnd_id, 0,
>> + ((u64)hdr_stat << 16 |
>> + (u64)sc_stat << 8 | (u64)icmnd_cmpl->flags),
>> + fwreq, icmnd_cmpl->resid, ctx);
>> +
>> + return;
>> + }
>> +
>> +
>> +#ifdef SNIC_DEBUG
>> + scsi_print_result(sc);
>> +#endif
>> +
>> + io_lock = snic_io_lock_hash(snic, sc);
>> +
>> + spin_lock_irqsave(io_lock, flags);
>> + rqi = (struct snic_req_info *) CMD_SP(sc);
>> + SNIC_SCSI_DBG(snic->shost,
>> + "Icmnd_cmpl:lun %lld sc %p cmd %xtag %d flags %xrqi %p\n",
>> + sc->device->lun, sc, sc->cmnd[0], snic_cmd_tag(sc),
>> + CMD_FLAGS(sc), rqi);
>> +
>> + SNIC_BUG_ON(rqi != (struct snic_req_info *)ctx);
>> + WARN_ON_ONCE(req);
>
>Now that is curious.
>'ctx' already points to the 'snic_req_info', so why do we need to
>have this double lookup here?
>'scsi_host_find_tag' above already will tell us if the command is
>valid; the tag map is managed by the driver, after all, so the
>driver will guarantee that a busy tag will not be reused.
>
>Why can't we do away with the 'CMD_SP' reference and get the
>scsi command via tag lookup?
>That would simplify the code by quite a bit ...
Yes, tag look up is more preferred way. The additional lookup is added to
catch driver and firmware synchronisation issues if there are any.
>
>> + if (!rqi) {
>> + atomic64_inc(&snic->s_stats.io.req_null);
>> + CMD_FLAGS(sc) |= SNIC_IO_REQ_NULL;
>> + spin_unlock_irqrestore(io_lock, flags);
>> +
>> + SNIC_HOST_ERR(snic->shost,
>> + "Icmnd_cmpl:Host Req Not Found(null), Hdr Status %s, Tag
>>0x%x, sc 0x%p flags 0x%x\n",
>> + snic_io_status_to_str(hdr_stat),
>> + cmnd_id, sc, CMD_FLAGS(sc));
>> + return;
>> + }
>> +
>> + rqi = (struct snic_req_info *) ctx;
>> + start_time = rqi->start_time;
>> +
>> + /* firmware completed the io */
>> + rqi->io_cmpl = 1;
>> +
>> + /*
>> + * if SCSI-ML has already issued abort on this command,
>> + * ignore completion of the IO. The abts path will clean it up
>> + */
>> + if (unlikely(snic_tmreq_pending(sc))) {
>> + snic_proc_tmreq_pending_state(snic, sc, hdr_stat);
>> + spin_unlock_irqrestore(io_lock, flags);
>> +
>> + snic_stats_update_io_cmpl(&snic->s_stats);
>> +
>> + /* Expected value is SNIC_STAT_ABORTED */
>> + if (likely(hdr_stat == SNIC_STAT_ABORTED))
>> + return;
>> +
>> + SNIC_SCSI_DBG(snic->shost,
>> + "icmnd_cmpl:TM Req Pending(%s), Hdr Status %s sc 0x%p scsi
>>status %x resid %d flags 0x%x\n",
>> + snic_ioreq_state_to_str(CMD_STATE(sc)),
>> + snic_io_status_to_str(hdr_stat),
>> + sc, sc_stat, icmnd_cmpl->resid, CMD_FLAGS(sc));
>> +
>> + SNIC_TRC(snic->shost->host_no, cmnd_id, sc,
>> + jiffies_to_msecs(jiffies - start_time), fwreq,
>> + SNIC_TRC_CMD(sc), SNIC_TRC_CMD_STATE_FLAGS(sc));
>> +
>> + return;
>> + }
>> +
>> + if (snic_process_icmnd_cmpl_status(snic, icmnd_cmpl, hdr_stat, sc)) {
>> +#ifdef SNIC_DEBUG
>> + scsi_print_command(sc);
>> +#endif
>> + SNIC_HOST_ERR(snic->shost,
>> + "icmnd_cmpl:IO Failed, sc 0x%p Tag %d Cmd %x Hdr Status %s
>>flags 0x%x\n",
>> + sc, sc->cmnd[0], cmnd_id,
>> + snic_io_status_to_str(hdr_stat), CMD_FLAGS(sc));
>> + }
>> +
>> + /* Break link with the SCSI Command */
>> + CMD_SP(sc) = NULL;
>> + CMD_FLAGS(sc) |= SNIC_IO_DONE;
>> +
>
>And then we wouldn't have to modify the CMD_SP() here ...
>
>> + spin_unlock_irqrestore(io_lock, flags);
>> +
>> + /* For now, consider only successful IO. */
>> + snic_calc_io_process_time(snic, rqi);
>> +
>> + snic_release_req_buf(snic, rqi, sc);
>> +
>> + SNIC_TRC(snic->shost->host_no, cmnd_id, (u64)sc,
>> + jiffies_to_msecs(jiffies - start_time), (u64)fwreq,
>> + SNIC_TRC_CMD(sc), SNIC_TRC_CMD_STATE_FLAGS(sc));
>> +
>> +
>> + if (sc->scsi_done)
>> + sc->scsi_done(sc);
>> +
>> + snic_stats_update_io_cmpl(&snic->s_stats);
>> +} /* end of snic_icmnd_cmpl_handler */
>> +
>> +static void
>> +snic_proc_dr_cmpl_locked(struct snic *snic,
>> + struct snic_fw_req *fwreq,
>> + u8 cmpl_stat,
>> + u32 cmnd_id,
>> + struct scsi_cmnd *sc)
>> +{
>> + struct snic_req_info *rqi = (struct snic_req_info *) CMD_SP(sc);
>> + u32 start_time = rqi->start_time;
>> +
>> + CMD_LR_STATUS(sc) = cmpl_stat;
>> +
>> + SNIC_SCSI_DBG(snic->shost, "itmf_cmpl: Cmd State = %s\n",
>> + snic_ioreq_state_to_str(CMD_STATE(sc)));
>> +
>> + if (CMD_STATE(sc) == SNIC_IOREQ_ABTS_PENDING) {
>> + CMD_FLAGS(sc) |= SNIC_DEV_RST_ABTS_PENDING;
>> +
>> + SNIC_TRC(snic->shost->host_no, cmnd_id, sc,
>> + jiffies_to_msecs(jiffies - start_time),
>> + fwreq, 0, SNIC_TRC_CMD_STATE_FLAGS(sc));
>> +
>> + SNIC_SCSI_DBG(snic->shost,
>> + "itmf_cmpl: Terminate Pending Dev Reset Cmpl Recvd.id %x,
>>status %s flags 0x%x\n",
>> + (int)(cmnd_id & SNIC_TAG_MASK),
>> + snic_io_status_to_str(cmpl_stat),
>> + CMD_FLAGS(sc));
>> +
>> + return;
>> + }
>> +
>> +
>> + if (CMD_FLAGS(sc) & SNIC_DEV_RST_TIMEDOUT) {
>> + SNIC_TRC(snic->shost->host_no, cmnd_id, sc,
>> + jiffies_to_msecs(jiffies - start_time),
>> + fwreq, 0, SNIC_TRC_CMD_STATE_FLAGS(sc));
>> +
>> + SNIC_SCSI_DBG(snic->shost,
>> + "itmf_cmpl:Dev Reset Completion Received after timeout. id %d
>>cmpl status %s flags 0x%x\n",
>> + (int)(cmnd_id & SNIC_TAG_MASK),
>> + snic_io_status_to_str(cmpl_stat),
>> + CMD_FLAGS(sc));
>> +
>> + return;
>> + }
>> +
>> + CMD_STATE(sc) = SNIC_IOREQ_LR_COMPLETE;
>> + CMD_FLAGS(sc) |= SNIC_DEV_RST_DONE;
>> +
>> + SNIC_SCSI_DBG(snic->shost,
>> + "itmf_cmpl:Dev Reset Cmpl Recvd id %d cmpl status %s flags
>>0x%x\n",
>> + (int)(cmnd_id & SNIC_TAG_MASK),
>> + snic_io_status_to_str(cmpl_stat),
>> + CMD_FLAGS(sc));
>> +
>> + if (rqi->dr_done)
>> + complete(rqi->dr_done);
>> +} /* end of snic_proc_dr_cmpl_locked */
>> +
>> +/*
>> + * snic_update_abort_stats : Updates abort stats based on completion
>>status.
>> + */
>> +static void
>> +snic_update_abort_stats(struct snic *snic, u8 cmpl_stat)
>> +{
>> + struct snic_abort_stats *abt_stats = &snic->s_stats.abts;
>> +
>> + SNIC_SCSI_DBG(snic->shost, "Updating Abort stats.\n");
>> +
>> + switch (cmpl_stat) {
>> + case SNIC_STAT_IO_SUCCESS:
>> + break;
>> +
>> + case SNIC_STAT_TIMEOUT:
>> + atomic64_inc(&abt_stats->fw_tmo);
>> + break;
>> +
>> + case SNIC_STAT_IO_NOT_FOUND:
>> + atomic64_inc(&abt_stats->io_not_found);
>> + break;
>> +
>> + default:
>> + atomic64_inc(&abt_stats->fail);
>> + break;
>> + }
>> +}
>> +
>> +static int
>> +snic_process_itmf_cmpl(struct snic *snic,
>> + struct snic_fw_req *fwreq,
>> + u32 cmnd_id,
>> + u8 cmpl_stat,
>> + struct scsi_cmnd *sc)
>> +{
>> + struct snic_req_info *rqi = NULL;
>> + u32 tm_tags = 0;
>> + spinlock_t *io_lock = NULL;
>> + unsigned long flags;
>> + u32 start_time = 0;
>> + int ret = 0;
>> +
>> + io_lock = snic_io_lock_hash(snic, sc);
>> + spin_lock_irqsave(io_lock, flags);
>> + rqi = (struct snic_req_info *) CMD_SP(sc);
>> + WARN_ON_ONCE(!rqi);
>> +
>> + if (!rqi) {
>> + atomic64_inc(&snic->s_stats.io.req_null);
>> + spin_unlock_irqrestore(io_lock, flags);
>> + CMD_FLAGS(sc) |= SNIC_IO_ABTS_TERM_REQ_NULL;
>> + SNIC_HOST_ERR(snic->shost,
>> + "itmf_cmpl: rqi is null,Hdr stat = %s Tag = 0x%x sc = 0x%p
>>flags 0x%x\n",
>> + snic_io_status_to_str(cmpl_stat), cmnd_id, sc,
>> + CMD_FLAGS(sc));
>> +
>> + return ret;
>> + }
>> +
>> + /* Extract task management flags */
>> + tm_tags = cmnd_id & ~(SNIC_TAG_MASK);
>> +
>> + start_time = rqi->start_time;
>> + cmnd_id &= (SNIC_TAG_MASK);
>> +
>> + switch (tm_tags) {
>> + case SNIC_TAG_ABORT:
>> + /* Abort only issued on cmd */
>> + snic_update_abort_stats(snic, cmpl_stat);
>> +
>> + if (CMD_STATE(sc) != SNIC_IOREQ_ABTS_PENDING) {
>> + /* This is a late completion. Ignore it. */
>> + ret = -1;
>> + spin_unlock_irqrestore(io_lock, flags);
>> + break;
>> + }
>> +
>> + CMD_STATE(sc) = SNIC_IOREQ_ABTS_COMPLETE;
>> + CMD_ABTS_STATUS(sc) = cmpl_stat;
>> + CMD_FLAGS(sc) |= SNIC_IO_ABTS_TERM_DONE;
>> +
>> + SNIC_SCSI_DBG(snic->shost,
>> + "itmf_cmpl:Abort Cmpl Recvd.Tag 0x%x Status %s flags 0x%x\n",
>> + cmnd_id,
>> + snic_io_status_to_str(cmpl_stat),
>> + CMD_FLAGS(sc));
>> +
>> + /*
>> + * If scsi_eh thread is blocked waiting for abts complete,
>> + * signal completion to it. IO will be cleaned in the thread,
>> + * else clean it in this context.
>> + */
>> + if (rqi->abts_done) {
>> + complete(rqi->abts_done);
>> + spin_unlock_irqrestore(io_lock, flags);
>> +
>> + break; /* jump out */
>> + }
>> +
>> + CMD_SP(sc) = NULL;
>> + sc->result = (DID_ERROR << 16);
>> + SNIC_SCSI_DBG(snic->shost,
>> + "itmf_cmpl: Completing IO. sc %p flags 0x%x\n",
>> + sc, CMD_FLAGS(sc));
>> +
>> + spin_unlock_irqrestore(io_lock, flags);
>> +
>> + snic_release_req_buf(snic, rqi, sc);
>> +
>> + if (sc->scsi_done) {
>> + SNIC_TRC(snic->shost->host_no, cmnd_id, sc,
>> + jiffies_to_msecs(jiffies - start_time),
>> + fwreq,
>> + SNIC_TRC_CMD(sc),
>> + SNIC_TRC_CMD_STATE_FLAGS(sc));
>> +
>> + sc->scsi_done(sc);
>> + }
>> +
>> + break;
>> +
>> + case SNIC_TAG_DEV_RST:
>> + case SNIC_TAG_DEV_RST | SNIC_TAG_IOCTL_DEV_RST:
>> + snic_proc_dr_cmpl_locked(snic, fwreq, cmpl_stat, cmnd_id, sc);
>> + spin_unlock_irqrestore(io_lock, flags);
>> + ret = 0;
>> +
>> + break;
>> +
>> + case SNIC_TAG_ABORT | SNIC_TAG_DEV_RST:
>> + /* Abort and terminate completion of device reset req */
>> +
>> + CMD_STATE(sc) = SNIC_IOREQ_ABTS_COMPLETE;
>> + CMD_ABTS_STATUS(sc) = cmpl_stat;
>> + CMD_FLAGS(sc) |= SNIC_DEV_RST_DONE;
>> +
>> + SNIC_SCSI_DBG(snic->shost,
>> + "itmf_cmpl:dev reset abts cmpl recvd. id %d status %s flags
>>0x%x\n",
>> + cmnd_id, snic_io_status_to_str(cmpl_stat),
>> + CMD_FLAGS(sc));
>> +
>> + if (rqi->abts_done)
>> + complete(rqi->abts_done);
>> +
>> + spin_unlock_irqrestore(io_lock, flags);
>> +
>> + break;
>> +
>> + default:
>> + spin_unlock_irqrestore(io_lock, flags);
>> + SNIC_HOST_ERR(snic->shost,
>> + "itmf_cmpl: Unknown TM tag bit 0x%x\n", tm_tags);
>> +
>> + SNIC_HOST_ERR(snic->shost,
>> + "itmf_cmpl:Unexpected itmf io stat %s Tag = 0x%x flags
>>0x%x\n",
>> + snic_ioreq_state_to_str(CMD_STATE(sc)),
>> + cmnd_id,
>> + CMD_FLAGS(sc));
>> + ret = -1;
>> + SNIC_BUG_ON(1);
>> +
>> + break;
>> + }
>> +
>> + return ret;
>> +} /* end of snic_process_itmf_cmpl_status */
>> +
>> +/*
>> + * snic_itmf_cmpl_handler.
>> + * Routine to handle itmf completions.
>> + */
>> +static void
>> +snic_itmf_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
>> +{
>> + struct scsi_cmnd *sc = NULL;
>> + struct snic_req_info *rqi = NULL;
>> + struct snic_itmf_cmpl *itmf_cmpl = NULL;
>> + u64 ctx;
>> + u32 cmnd_id;
>> + u32 hid;
>> + u8 typ;
>> + u8 hdr_stat;
>> +
>> + snic_io_hdr_dec(&fwreq->hdr, &typ, &hdr_stat, &cmnd_id, &hid, &ctx);
>> + SNIC_SCSI_DBG(snic->shost,
>> + "Itmf_cmpl: %s: type = %x, hdr_stat = %x, cmnd_id = %x, hid =
>>%x,ctx = %llx\n",
>> + __func__, typ, hdr_stat, cmnd_id, hid, ctx);
>> +
>> + itmf_cmpl = &fwreq->u.itmf_cmpl;
>> + SNIC_SCSI_DBG(snic->shost,
>> + "Itmf_cmpl: nterm %u , flags 0x%x\n",
>> + itmf_cmpl->nterminated, itmf_cmpl->flags);
>> +
>> + /* spl case, dev reset issued through ioctl */
>> + if (cmnd_id & SNIC_TAG_IOCTL_DEV_RST) {
>> + rqi = (struct snic_req_info *) ctx;
>> + sc = rqi->sc;
>> +
>> + goto ioctl_dev_rst;
>> + }
>> +
>> + if ((cmnd_id & SNIC_TAG_MASK) >= snic->max_tag_id) {
>> + SNIC_HOST_ERR(snic->shost,
>> + "Itmf_cmpl: Tag 0x%x out of Range,HdrStat %s\n",
>> + cmnd_id, snic_io_status_to_str(hdr_stat));
>> + SNIC_BUG_ON(1);
>> +
>> + return;
>> + }
>> +
>> + sc = scsi_host_find_tag(snic->shost, cmnd_id & SNIC_TAG_MASK);
>> + WARN_ON_ONCE(!sc);
>> +
>Same issue here.
>Why can't you rely on the tag to get the command?
>Then you wouldn't have to to the triple indirection
>
>rqi->sc->rpi
>
>_and_ you would be insulated against command timeouts, where
>'sc' might become invalid ...
Yes, all the time driver relies on tag to get scsi command. But there are
few instances, where scsi command is not associated with a tag. For
example lun reset or host reset are issued through ioctl. In the
exceptional case, where scsi command is not associated with a valid tag,
then driver uses this triple redirection. It is common code to handle
tagged and untagged commands.
>
>> +ioctl_dev_rst:
>> + if (!sc) {
>> + atomic64_inc(&snic->s_stats.io.sc_null);
>> + SNIC_HOST_ERR(snic->shost,
>> + "Itmf_cmpl: sc is NULL - Hdr Stat %s Tag 0x%x\n",
>> + snic_io_status_to_str(hdr_stat), cmnd_id);
>> +
>> + return;
>> + }
>> +
>> + snic_process_itmf_cmpl(snic, fwreq, cmnd_id, hdr_stat, sc);
>> +} /* end of snic_itmf_cmpl_handler */
>> +
>> +
>> +
>> +static void
>> +snic_hba_reset_scsi_cleanup(struct snic *snic, struct scsi_cmnd *sc)
>> +{
>> + struct snic_stats *st = &snic->s_stats;
>> + long act_ios = 0, act_fwreqs = 0;
>> +
>> + SNIC_SCSI_DBG(snic->shost, "HBA Reset scsi cleanup.\n");
>> + snic_scsi_cleanup(snic, snic_cmd_tag(sc));
>> +
>> + /* Update stats on pending IOs */
>> + act_ios = atomic64_read(&st->io.active);
>> + atomic64_add(act_ios, &st->io.compl);
>> + atomic64_sub(act_ios, &st->io.active);
>> +
>> + act_fwreqs = atomic64_read(&st->fw.actv_reqs);
>> + atomic64_sub(act_fwreqs, &st->fw.actv_reqs);
>> +}
>> +
>> +/*
>> + * snic_hba_reset_cmpl_handler :
>> + *
>> + * Notes :
>> + * 1. Cleanup all the scsi cmds, release all snic specific cmds
>> + * 2. Issue Report Targets in case of SAN targets
>> + */
>> +static int
>> +snic_hba_reset_cmpl_handler(struct snic *snic, struct snic_fw_req
>>*fwreq)
>> +{
>> + u64 ctx;
>> + u32 cmnd_id;
>> + u32 hid;
>> + u8 typ;
>> + u8 hdr_stat;
>> + struct scsi_cmnd *sc = NULL;
>> + struct snic_req_info *rqi = NULL;
>> + spinlock_t *io_lock = NULL;
>> + unsigned long flags, gflags;
>> + int ret = 0;
>> +
>> + SNIC_HOST_INFO(snic->shost,
>> + "reset_cmpl:HBA Reset Completion received.\n");
>> +
>> + snic_io_hdr_dec(&fwreq->hdr, &typ, &hdr_stat, &cmnd_id, &hid, &ctx);
>> + SNIC_SCSI_DBG(snic->shost,
>> + "reset_cmpl: type = %x, hdr_stat = %x, cmnd_id = %x, hid = %x,
>>ctx = %llx\n",
>> + typ, hdr_stat, cmnd_id, hid, ctx);
>> +
>> + /* spl case, host reset issued through ioctl */
>> + if (cmnd_id == SCSI_NO_TAG) {
>> + rqi = (struct snic_req_info *) ctx;
>> + sc = rqi->sc;
>> +
>> + goto ioctl_hba_rst;
>> + }
>> +
>> + if (cmnd_id >= snic->max_tag_id) {
>> + SNIC_HOST_ERR(snic->shost,
>> + "reset_cmpl: Tag 0x%x out of Range,HdrStat %s\n",
>> + cmnd_id, snic_io_status_to_str(hdr_stat));
>> + SNIC_BUG_ON(1);
>> +
>> + return 1;
>> + }
>> +
>> + sc = scsi_host_find_tag(snic->shost, cmnd_id);
>> +ioctl_hba_rst:
>> + if (!sc) {
>> + atomic64_inc(&snic->s_stats.io.sc_null);
>> + SNIC_HOST_ERR(snic->shost,
>> + "reset_cmpl: sc is NULL - Hdr Stat %s Tag 0x%x\n",
>> + snic_io_status_to_str(hdr_stat), cmnd_id);
>> + ret = 1;
>> +
>> + return ret;
>> + }
>> +
>> + io_lock = snic_io_lock_hash(snic, sc);
>> + spin_lock_irqsave(io_lock, flags);
>> +
>> + if (!snic->remove_wait) {
>> + spin_unlock_irqrestore(io_lock, flags);
>> + SNIC_HOST_ERR(snic->shost,
>> + "reset_cmpl:host reset completed after timout\n");
>> + ret = 1;
>> +
>> + return ret;
>> + }
>> +
>> + rqi = (struct snic_req_info *) CMD_SP(sc);
>> + WARN_ON_ONCE(!rqi);
>> +
>See above.
>
>If possible I would avoid keeping direct references to the scsi
>command in the firmware request structure; the scsi command might
>timeout while the firmware request is in flight, leaving the
>firmware request with a stale pointer.
>I would rather use the tag in the firmware request and use
>the tag lookup to get to the command.
You are correct. But there are few instances, where scsi command is not
associated with a tag. For example lun reset or host reset are issued
through ioctl. In the exceptional case, where scsi command is not
associated with a valid tag, driver accesses the scsi command directly.
>
>Cheers,
>
>Hannes
>--
>Dr. Hannes Reinecke zSeries & Storage
>hare@xxxxxxx +49 911 74053 688
>SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
>GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
>HRB 21284 (AG Nürnberg)
Thanks
Narsimhulu
>
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