NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain --- drivers/scsi/NCR5380.c | 194 +++++++++++++++++++--------------- drivers/scsi/NCR5380.h | 2 drivers/scsi/atari_NCR5380.c | 239 ++++++++++++++++++++++++------------------- 3 files changed, 249 insertions(+), 186 deletions(-) Index: linux/drivers/scsi/NCR5380.h =================================================================== --- linux.orig/drivers/scsi/NCR5380.h 2015-11-18 19:34:20.000000000 +1100 +++ linux/drivers/scsi/NCR5380.h 2015-11-18 19:34:24.000000000 +1100 @@ -257,10 +257,12 @@ struct NCR5380_hostdata { unsigned char last_message; /* last message OUT */ struct scsi_cmnd *connected; /* currently connected cmnd */ struct list_head unissued; /* waiting to be issued */ + struct list_head autosense; /* priority issue queue */ struct list_head disconnected; /* waiting for reconnect */ spinlock_t lock; /* protects this struct */ int flags; struct scsi_eh_save ses; + struct scsi_cmnd *sensing; char info[256]; int read_overruns; /* number of bytes to cut from a * transfer to handle chip overruns */ Index: linux/drivers/scsi/atari_NCR5380.c =================================================================== --- linux.orig/drivers/scsi/atari_NCR5380.c 2015-11-18 19:34:23.000000000 +1100 +++ linux/drivers/scsi/atari_NCR5380.c 2015-11-18 19:34:24.000000000 +1100 @@ -418,6 +418,9 @@ static inline void initialize_SCp(struct cmd->SCp.ptr = NULL; cmd->SCp.this_residual = 0; } + + cmd->SCp.Status = 0; + cmd->SCp.Message = 0; } /** @@ -672,6 +675,8 @@ static int __init NCR5380_init(struct Sc #endif spin_lock_init(&hostdata->lock); hostdata->connected = NULL; + hostdata->sensing = NULL; + INIT_LIST_HEAD(&hostdata->autosense); INIT_LIST_HEAD(&hostdata->unissued); INIT_LIST_HEAD(&hostdata->disconnected); @@ -774,6 +779,16 @@ static void complete_cmd(struct Scsi_Hos dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd); + if (hostdata->sensing == cmd) { + /* Autosense processing ends here */ + if ((cmd->result & 0xff) != SAM_STAT_GOOD) { + scsi_eh_restore_cmnd(cmd, &hostdata->ses); + set_host_byte(cmd, DID_ERROR); + } else + scsi_eh_restore_cmnd(cmd, &hostdata->ses); + hostdata->sensing = NULL; + } + #ifdef SUPPORT_TAGS cmd_free_tag(cmd); #else @@ -865,12 +880,77 @@ static inline void maybe_release_dma_irq /* Caller does the locking needed to set & test these data atomically */ if (list_empty(&hostdata->disconnected) && list_empty(&hostdata->unissued) && + list_empty(&hostdata->autosense) && !hostdata->connected && !hostdata->retain_dma_intr) NCR5380_release_dma_irq(instance); } /** + * dequeue_next_cmd - dequeue a command for processing + * @instance: the scsi host instance + * + * Priority is given to commands on the autosense queue. These commands + * need autosense because of a CHECK CONDITION result. + * + * Returns a command pointer if a command is found for a target that is + * not already busy. Otherwise returns NULL. + */ + +static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance) +{ + struct NCR5380_hostdata *hostdata = shost_priv(instance); + struct NCR5380_cmd *ncmd; + struct scsi_cmnd *cmd; + + if (list_empty(&hostdata->autosense)) { + list_for_each_entry(ncmd, &hostdata->unissued, list) { + cmd = NCR5380_to_scmd(ncmd); + dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n", + cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun); + + if ( +#ifdef SUPPORT_TAGS + !is_lun_busy(cmd, 1) +#else + !(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun)) +#endif + ) { + list_del(&ncmd->list); + dsprintk(NDEBUG_QUEUES, instance, + "dequeue: removed %p from issue queue\n", cmd); + return cmd; + } + } + } else { + /* Autosense processing begins here */ + ncmd = list_first_entry(&hostdata->autosense, + struct NCR5380_cmd, list); + list_del(&ncmd->list); + cmd = NCR5380_to_scmd(ncmd); + dsprintk(NDEBUG_QUEUES, instance, + "dequeue: removed %p from autosense queue\n", cmd); + scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0); + hostdata->sensing = cmd; + return cmd; + } + return NULL; +} + +static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd) +{ + struct NCR5380_hostdata *hostdata = shost_priv(instance); + struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd); + + if (hostdata->sensing) { + scsi_eh_restore_cmnd(cmd, &hostdata->ses); + list_add(&ncmd->list, &hostdata->autosense); + hostdata->sensing = NULL; + } else + list_add(&ncmd->list, &hostdata->unissued); +} + +/** * NCR5380_main - NCR state machines * * NCR5380_main is a coroutine that runs as long as more work can @@ -886,7 +966,7 @@ static void NCR5380_main(struct work_str struct NCR5380_hostdata *hostdata = container_of(work, struct NCR5380_hostdata, main_task); struct Scsi_Host *instance = hostdata->host; - struct NCR5380_cmd *ncmd, *n; + struct scsi_cmnd *cmd; int done; /* @@ -899,75 +979,46 @@ static void NCR5380_main(struct work_str do { done = 1; - if (!hostdata->connected) { - dprintk(NDEBUG_MAIN, "scsi%d: not connected\n", HOSTNO); - /* - * Search through the issue_queue for a command destined - * for a target that's not busy. - */ - list_for_each_entry_safe(ncmd, n, &hostdata->unissued, - list) { - struct scsi_cmnd *tmp = NCR5380_to_scmd(ncmd); - u8 lun = tmp->device->lun; - - dsprintk(NDEBUG_QUEUES, instance, "main: tmp=%p target=%d busy=%d lun=%d\n", - tmp, scmd_id(tmp), hostdata->busy[scmd_id(tmp)], lun); - /* When we find one, remove it from the issue queue. */ - if ( -#ifdef SUPPORT_TAGS - !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE) -#else - !(hostdata->busy[tmp->device->id] & (1 << lun)) -#endif - ) { - list_del(&ncmd->list); - dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, - instance, "main: removed %p from issue queue\n", - tmp); + while (!hostdata->connected && + (cmd = dequeue_next_cmd(instance))) { - hostdata->retain_dma_intr++; + dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd); - /* - * Attempt to establish an I_T_L nexus here. - * On success, instance->hostdata->connected is set. - * On failure, we must add the command back to the - * issue queue so we can keep trying. - */ - /* - * REQUEST SENSE commands are issued without tagged - * queueing, even on SCSI-II devices because the - * contingent allegiance condition exists for the - * entire unit. - */ - /* ++roman: ...and the standard also requires that - * REQUEST SENSE command are untagged. - */ + /* + * Attempt to establish an I_T_L nexus here. + * On success, instance->hostdata->connected is set. + * On failure, we must add the command back to the + * issue queue so we can keep trying. + */ + /* + * REQUEST SENSE commands are issued without tagged + * queueing, even on SCSI-II devices because the + * contingent allegiance condition exists for the + * entire unit. + */ + /* ++roman: ...and the standard also requires that + * REQUEST SENSE command are untagged. + */ #ifdef SUPPORT_TAGS - cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE); + cmd_get_tag(cmd, cmd->cmnd[0] != REQUEST_SENSE); #endif - if (!NCR5380_select(instance, tmp)) { - /* OK or bad target */ - hostdata->retain_dma_intr--; - maybe_release_dma_irq(instance); - } else { - /* Need to retry */ - list_add(&ncmd->list, &hostdata->unissued); - dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, - instance, "main: select() failed, %p returned to issue queue\n", - tmp); + hostdata->retain_dma_intr++; + if (!NCR5380_select(instance, cmd)) { + dsprintk(NDEBUG_MAIN, instance, "main: selected target %d for command %p\n", + scmd_id(cmd), cmd); + hostdata->retain_dma_intr--; + maybe_release_dma_irq(instance); + } else { + hostdata->retain_dma_intr--; + dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance, + "main: select failed, returning %p to queue\n", cmd); + requeue_cmd(instance, cmd); #ifdef SUPPORT_TAGS - cmd_free_tag(tmp); + cmd_free_tag(cmd); #endif - hostdata->retain_dma_intr--; - done = 0; - } - if (hostdata->connected) - break; - } /* if target/lun/target queue is not busy */ - } /* for issue_queue */ - } /* if (!hostdata->connected) */ - + } + } if (hostdata->connected #ifdef REAL_DMA && !hostdata->dma_len @@ -2011,48 +2062,21 @@ static void NCR5380_information_transfer } #endif - /* - * I'm not sure what the correct thing to do here is : - * - * If the command that just executed is NOT a request - * sense, the obvious thing to do is to set the result - * code to the values of the stored parameters. - * - * If it was a REQUEST SENSE command, we need some way to - * differentiate between the failure code of the original - * and the failure code of the REQUEST sense - the obvious - * case is success, where we fall through and leave the - * result code unchanged. - * - * The non-obvious place is where the REQUEST SENSE failed - */ + cmd->result &= ~0xffff; + cmd->result |= cmd->SCp.Status; + cmd->result |= cmd->SCp.Message << 8; - if (cmd->cmnd[0] != REQUEST_SENSE) - cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8); - else if (status_byte(cmd->SCp.Status) != GOOD) - cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16); - - if ((cmd->cmnd[0] == REQUEST_SENSE) && - hostdata->ses.cmd_len) { - scsi_eh_restore_cmnd(cmd, &hostdata->ses); - hostdata->ses.cmd_len = 0 ; - } - - if ((cmd->cmnd[0] != REQUEST_SENSE) && - (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) { - scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0); - - list_add(&ncmd->list, &hostdata->unissued); - dsprintk(NDEBUG_AUTOSENSE | NDEBUG_QUEUES, - instance, "REQUEST SENSE cmd %p added to head of issue queue\n", - cmd); -#ifdef SUPPORT_TAGS - cmd_free_tag(cmd); -#else - hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun); -#endif - } else { + if (cmd->cmnd[0] == REQUEST_SENSE) complete_cmd(instance, cmd); + else { + if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION || + cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) { + dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n", + cmd); + list_add_tail(&ncmd->list, + &hostdata->autosense); + } else + complete_cmd(instance, cmd); } /* @@ -2542,6 +2566,15 @@ static int NCR5380_bus_reset(struct scsi dsprintk(NDEBUG_ABORT, instance, "reset aborted a connected command\n"); hostdata->connected = NULL; + if (hostdata->sensing) { + complete_cmd(instance, hostdata->sensing); + hostdata->sensing = NULL; + } + + if (!list_empty(&hostdata->autosense)) + dsprintk(NDEBUG_ABORT, instance, "reset aborted autosense list\n"); + INIT_LIST_HEAD(&hostdata->autosense); + if (!list_empty(&hostdata->unissued)) dsprintk(NDEBUG_ABORT, instance, "reset aborted unissued list\n"); INIT_LIST_HEAD(&hostdata->unissued); Index: linux/drivers/scsi/NCR5380.c =================================================================== --- linux.orig/drivers/scsi/NCR5380.c 2015-11-18 19:34:23.000000000 +1100 +++ linux/drivers/scsi/NCR5380.c 2015-11-18 19:34:24.000000000 +1100 @@ -244,6 +244,9 @@ static inline void initialize_SCp(struct cmd->SCp.ptr = NULL; cmd->SCp.this_residual = 0; } + + cmd->SCp.Status = 0; + cmd->SCp.Message = 0; } /** @@ -633,6 +636,8 @@ static int NCR5380_init(struct Scsi_Host #endif spin_lock_init(&hostdata->lock); hostdata->connected = NULL; + hostdata->sensing = NULL; + INIT_LIST_HEAD(&hostdata->autosense); INIT_LIST_HEAD(&hostdata->unissued); INIT_LIST_HEAD(&hostdata->disconnected); @@ -734,6 +739,16 @@ static void complete_cmd(struct Scsi_Hos dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd); + if (hostdata->sensing == cmd) { + /* Autosense processing ends here */ + if ((cmd->result & 0xff) != SAM_STAT_GOOD) { + scsi_eh_restore_cmnd(cmd, &hostdata->ses); + set_host_byte(cmd, DID_ERROR); + } else + scsi_eh_restore_cmnd(cmd, &hostdata->ses); + hostdata->sensing = NULL; + } + hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun); cmd->scsi_done(cmd); @@ -794,6 +809,64 @@ static int NCR5380_queue_command(struct } /** + * dequeue_next_cmd - dequeue a command for processing + * @instance: the scsi host instance + * + * Priority is given to commands on the autosense queue. These commands + * need autosense because of a CHECK CONDITION result. + * + * Returns a command pointer if a command is found for a target that is + * not already busy. Otherwise returns NULL. + */ + +static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance) +{ + struct NCR5380_hostdata *hostdata = shost_priv(instance); + struct NCR5380_cmd *ncmd; + struct scsi_cmnd *cmd; + + if (list_empty(&hostdata->autosense)) { + list_for_each_entry(ncmd, &hostdata->unissued, list) { + cmd = NCR5380_to_scmd(ncmd); + dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n", + cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun); + + if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) { + list_del(&ncmd->list); + dsprintk(NDEBUG_QUEUES, instance, + "dequeue: removed %p from issue queue\n", cmd); + return cmd; + } + } + } else { + /* Autosense processing begins here */ + ncmd = list_first_entry(&hostdata->autosense, + struct NCR5380_cmd, list); + list_del(&ncmd->list); + cmd = NCR5380_to_scmd(ncmd); + dsprintk(NDEBUG_QUEUES, instance, + "dequeue: removed %p from autosense queue\n", cmd); + scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0); + hostdata->sensing = cmd; + return cmd; + } + return NULL; +} + +static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd) +{ + struct NCR5380_hostdata *hostdata = shost_priv(instance); + struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd); + + if (hostdata->sensing) { + scsi_eh_restore_cmnd(cmd, &hostdata->ses); + list_add(&ncmd->list, &hostdata->autosense); + hostdata->sensing = NULL; + } else + list_add(&ncmd->list, &hostdata->unissued); +} + +/** * NCR5380_main - NCR state machines * * NCR5380_main is a coroutine that runs as long as more work can @@ -810,63 +883,40 @@ static void NCR5380_main(struct work_str struct NCR5380_hostdata *hostdata = container_of(work, struct NCR5380_hostdata, main_task); struct Scsi_Host *instance = hostdata->host; - struct NCR5380_cmd *ncmd, *n; + struct scsi_cmnd *cmd; int done; spin_lock_irq(&hostdata->lock); do { done = 1; - if (!hostdata->connected) { - dprintk(NDEBUG_MAIN, "scsi%d : not connected\n", instance->host_no); + while (!hostdata->connected && + (cmd = dequeue_next_cmd(instance))) { + + dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd); + /* - * Search through the issue_queue for a command destined - * for a target that's not busy. + * Attempt to establish an I_T_L nexus here. + * On success, instance->hostdata->connected is set. + * On failure, we must add the command back to the + * issue queue so we can keep trying. + */ + /* + * REQUEST SENSE commands are issued without tagged + * queueing, even on SCSI-II devices because the + * contingent allegiance condition exists for the + * entire unit. */ - list_for_each_entry_safe(ncmd, n, &hostdata->unissued, - list) { - struct scsi_cmnd *tmp = NCR5380_to_scmd(ncmd); - - dsprintk(NDEBUG_QUEUES, instance, "main: tmp=%p target=%d busy=%d lun=%llu\n", - tmp, scmd_id(tmp), hostdata->busy[scmd_id(tmp)], - tmp->device->lun); - /* When we find one, remove it from the issue queue. */ - if (!(hostdata->busy[tmp->device->id] & - (1 << (u8)(tmp->device->lun & 0xff)))) { - list_del(&ncmd->list); - dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, - instance, "main: removed %p from issue queue\n", - tmp); - - /* - * Attempt to establish an I_T_L nexus here. - * On success, instance->hostdata->connected is set. - * On failure, we must add the command back to the - * issue queue so we can keep trying. - */ - /* - * REQUEST SENSE commands are issued without tagged - * queueing, even on SCSI-II devices because the - * contingent allegiance condition exists for the - * entire unit. - */ - - if (!NCR5380_select(instance, tmp)) { - /* OK or bad target */ - } else { - /* Need to retry */ - list_add(&ncmd->list, &hostdata->unissued); - dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, - instance, "main: select() failed, %p returned to issue queue\n", - tmp); - done = 0; - } - if (hostdata->connected) - break; - } /* if target/lun is not busy */ - } /* for */ - } /* if (!hostdata->connected) */ + if (!NCR5380_select(instance, cmd)) { + dsprintk(NDEBUG_MAIN, instance, "main: selected target %d for command %p\n", + scmd_id(cmd), cmd); + } else { + dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance, + "main: select failed, returning %p to queue\n", cmd); + requeue_cmd(instance, cmd); + } + } if (hostdata->connected #ifdef REAL_DMA && !hostdata->dmalen @@ -1860,43 +1910,21 @@ static void NCR5380_information_transfer hostdata->connected = NULL; - /* - * I'm not sure what the correct thing to do here is : - * - * If the command that just executed is NOT a request - * sense, the obvious thing to do is to set the result - * code to the values of the stored parameters. - * - * If it was a REQUEST SENSE command, we need some way - * to differentiate between the failure code of the original - * and the failure code of the REQUEST sense - the obvious - * case is success, where we fall through and leave the result - * code unchanged. - * - * The non-obvious place is where the REQUEST SENSE failed - */ - - if (cmd->cmnd[0] != REQUEST_SENSE) - cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8); - else if (status_byte(cmd->SCp.Status) != GOOD) - cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16); - - if ((cmd->cmnd[0] == REQUEST_SENSE) && - hostdata->ses.cmd_len) { - scsi_eh_restore_cmnd(cmd, &hostdata->ses); - hostdata->ses.cmd_len = 0 ; - } - - if ((cmd->cmnd[0] != REQUEST_SENSE) && (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) { - scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0); + cmd->result &= ~0xffff; + cmd->result |= cmd->SCp.Status; + cmd->result |= cmd->SCp.Message << 8; - list_add(&ncmd->list, &hostdata->unissued); - dsprintk(NDEBUG_AUTOSENSE | NDEBUG_QUEUES, - instance, "REQUEST SENSE cmd %p added to head of issue queue\n", - cmd); - hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xFF)); - } else { + if (cmd->cmnd[0] == REQUEST_SENSE) complete_cmd(instance, cmd); + else { + if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION || + cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) { + dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n", + cmd); + list_add_tail(&ncmd->list, + &hostdata->autosense); + } else + complete_cmd(instance, cmd); } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/