diff options
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r-- | drivers/scsi/scsi_lib.c | 165 |
1 files changed, 127 insertions, 38 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 50a6e1ac8d9c..7e3d954c9cac 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -22,6 +22,7 @@ #include <linux/hardirq.h> #include <linux/scatterlist.h> #include <linux/blk-mq.h> +#include <linux/ratelimit.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> @@ -47,7 +48,7 @@ struct scsi_host_sg_pool { mempool_t *pool; }; -#define SP(x) { x, "sgpool-" __stringify(x) } +#define SP(x) { .size = x, "sgpool-" __stringify(x) } #if (SCSI_MAX_SG_SEGMENTS < 32) #error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater) #endif @@ -542,17 +543,6 @@ static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) put_device(&sdev->sdev_gendev); } -void scsi_next_command(struct scsi_cmnd *cmd) -{ - struct scsi_device *sdev = cmd->device; - struct request_queue *q = sdev->request_queue; - - scsi_put_command(cmd); - scsi_run_queue(q); - - put_device(&sdev->sdev_gendev); -} - void scsi_run_host_queues(struct Scsi_Host *shost) { struct scsi_device *sdev; @@ -598,10 +588,10 @@ static void scsi_free_sgtable(struct scsi_data_buffer *sdb, bool mq) __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, mq, scsi_sg_free); } -static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, - gfp_t gfp_mask, bool mq) +static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, bool mq) { struct scatterlist *first_chunk = NULL; + gfp_t gfp_mask = mq ? GFP_NOIO : GFP_ATOMIC; int ret; BUG_ON(!nents); @@ -730,8 +720,6 @@ static bool scsi_end_request(struct request *req, int error, kblockd_schedule_work(&sdev->requeue_work); else blk_mq_start_stopped_hw_queues(q, true); - - put_device(&sdev->sdev_gendev); } else { unsigned long flags; @@ -743,9 +731,12 @@ static bool scsi_end_request(struct request *req, int error, spin_unlock_irqrestore(q->queue_lock, flags); scsi_release_buffers(cmd); - scsi_next_command(cmd); + + scsi_put_command(cmd); + scsi_run_queue(q); } + put_device(&sdev->sdev_gendev); return false; } @@ -831,8 +822,8 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) struct request *req = cmd->request; int error = 0; struct scsi_sense_hdr sshdr; - int sense_valid = 0; - int sense_deferred = 0; + bool sense_valid = false; + int sense_deferred = 0, level = 0; enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, ACTION_DELAYED_RETRY} action; unsigned long wait_for = (cmd->allowed + 1) * req->timeout; @@ -912,7 +903,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) ; else if (!(req->cmd_flags & REQ_QUIET)) - scsi_print_sense("", cmd); + scsi_print_sense(cmd); result = 0; /* BLOCK_PC may have set error */ error = 0; @@ -1039,10 +1030,24 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) case ACTION_FAIL: /* Give up and fail the remainder of the request */ if (!(req->cmd_flags & REQ_QUIET)) { - scsi_print_result(cmd); - if (driver_byte(result) & DRIVER_SENSE) - scsi_print_sense("", cmd); - scsi_print_command(cmd); + static DEFINE_RATELIMIT_STATE(_rs, + DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + + if (unlikely(scsi_logging_level)) + level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, + SCSI_LOG_MLCOMPLETE_BITS); + + /* + * if logging is enabled the failure will be printed + * in scsi_log_completion(), so avoid duplicate messages + */ + if (!level && __ratelimit(&_rs)) { + scsi_print_result(cmd, NULL, FAILED); + if (driver_byte(result) & DRIVER_SENSE) + scsi_print_sense(cmd); + scsi_print_command(cmd); + } } if (!scsi_end_request(req, error, blk_rq_err_bytes(req), 0)) return; @@ -1072,8 +1077,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) } } -static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, - gfp_t gfp_mask) +static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb) { int count; @@ -1081,7 +1085,7 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, * If sg table allocation fails, requeue request later. */ if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments, - gfp_mask, req->mq_ctx != NULL))) + req->mq_ctx != NULL))) return BLKPREP_DEFER; /* @@ -1106,7 +1110,7 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, * BLKPREP_DEFER if the failure is retryable * BLKPREP_KILL if the failure is fatal */ -int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) +int scsi_init_io(struct scsi_cmnd *cmd) { struct scsi_device *sdev = cmd->device; struct request *rq = cmd->request; @@ -1115,7 +1119,7 @@ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) BUG_ON(!rq->nr_phys_segments); - error = scsi_init_sgtable(rq, &cmd->sdb, gfp_mask); + error = scsi_init_sgtable(rq, &cmd->sdb); if (error) goto err_exit; @@ -1131,8 +1135,7 @@ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) rq->next_rq->special = bidi_sdb; } - error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special, - GFP_ATOMIC); + error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special); if (error) goto err_exit; } @@ -1144,7 +1147,7 @@ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) BUG_ON(prot_sdb == NULL); ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); - if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask, is_mq)) { + if (scsi_alloc_sgtable(prot_sdb, ivecs, is_mq)) { error = BLKPREP_DEFER; goto err_exit; } @@ -1213,7 +1216,7 @@ static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) * submit a request without an attached bio. */ if (req->bio) { - int ret = scsi_init_io(cmd, GFP_ATOMIC); + int ret = scsi_init_io(cmd); if (unlikely(ret)) return ret; } else { @@ -1638,6 +1641,87 @@ static void scsi_softirq_done(struct request *rq) } /** + * scsi_dispatch_command - Dispatch a command to the low-level driver. + * @cmd: command block we are dispatching. + * + * Return: nonzero return request was rejected and device's queue needs to be + * plugged. + */ +static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) +{ + struct Scsi_Host *host = cmd->device->host; + int rtn = 0; + + atomic_inc(&cmd->device->iorequest_cnt); + + /* check if the device is still usable */ + if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { + /* in SDEV_DEL we error all commands. DID_NO_CONNECT + * returns an immediate error upwards, and signals + * that the device is no longer present */ + cmd->result = DID_NO_CONNECT << 16; + goto done; + } + + /* Check to see if the scsi lld made this device blocked. */ + if (unlikely(scsi_device_blocked(cmd->device))) { + /* + * in blocked state, the command is just put back on + * the device queue. The suspend state has already + * blocked the queue so future requests should not + * occur until the device transitions out of the + * suspend state. + */ + SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, + "queuecommand : device blocked\n")); + return SCSI_MLQUEUE_DEVICE_BUSY; + } + + /* Store the LUN value in cmnd, if needed. */ + if (cmd->device->lun_in_cdb) + cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | + (cmd->device->lun << 5 & 0xe0); + + scsi_log_send(cmd); + + /* + * Before we queue this command, check if the command + * length exceeds what the host adapter can handle. + */ + if (cmd->cmd_len > cmd->device->host->max_cmd_len) { + SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, + "queuecommand : command too long. " + "cdb_size=%d host->max_cmd_len=%d\n", + cmd->cmd_len, cmd->device->host->max_cmd_len)); + cmd->result = (DID_ABORT << 16); + goto done; + } + + if (unlikely(host->shost_state == SHOST_DEL)) { + cmd->result = (DID_NO_CONNECT << 16); + goto done; + + } + + trace_scsi_dispatch_cmd_start(cmd); + rtn = host->hostt->queuecommand(host, cmd); + if (rtn) { + trace_scsi_dispatch_cmd_error(cmd, rtn); + if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && + rtn != SCSI_MLQUEUE_TARGET_BUSY) + rtn = SCSI_MLQUEUE_HOST_BUSY; + + SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, + "queuecommand : request rejected\n")); + } + + return rtn; + done: + cmd->scsi_done(cmd); + return 0; +} + +/** * scsi_done - Invoke completion on finished SCSI command. * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives * ownership back to SCSI Core -- i.e. the LLDD has finished with it. @@ -1725,7 +1809,7 @@ static void scsi_request_fn(struct request_queue *q) * we add the dev to the starved list so it eventually gets * a run when a tag is freed. */ - if (blk_queue_tagged(q) && !blk_rq_tagged(req)) { + if (blk_queue_tagged(q) && !(req->cmd_flags & REQ_QUEUED)) { spin_lock_irq(shost->host_lock); if (list_empty(&sdev->starved_entry)) list_add_tail(&sdev->starved_entry, @@ -1739,6 +1823,11 @@ static void scsi_request_fn(struct request_queue *q) if (!scsi_host_queue_ready(q, shost, sdev)) goto host_not_ready; + + if (sdev->simple_tags) + cmd->flags |= SCMD_TAGGED; + else + cmd->flags &= ~SCMD_TAGGED; /* * Finally, initialize any error handling parameters, and set up @@ -1893,10 +1982,10 @@ static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req, blk_mq_start_request(req); } - if (blk_queue_tagged(q)) - req->cmd_flags |= REQ_QUEUED; + if (sdev->simple_tags) + cmd->flags |= SCMD_TAGGED; else - req->cmd_flags &= ~REQ_QUEUED; + cmd->flags &= ~SCMD_TAGGED; scsi_init_cmd_errh(cmd); cmd->scsi_done = scsi_mq_done; @@ -2091,7 +2180,7 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost) memset(&shost->tag_set, 0, sizeof(shost->tag_set)); shost->tag_set.ops = &scsi_mq_ops; - shost->tag_set.nr_hw_queues = 1; + shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1; shost->tag_set.queue_depth = shost->can_queue; shost->tag_set.cmd_size = cmd_size; shost->tag_set.numa_node = NUMA_NO_NODE; |