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path: root/drivers/scsi/scsi_lib.c
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Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c164
1 files changed, 129 insertions, 35 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 9eff8a375132..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
@@ -1893,6 +1982,11 @@ static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req,
blk_mq_start_request(req);
}
+ if (sdev->simple_tags)
+ cmd->flags |= SCMD_TAGGED;
+ else
+ cmd->flags &= ~SCMD_TAGGED;
+
scsi_init_cmd_errh(cmd);
cmd->scsi_done = scsi_mq_done;
@@ -2086,7 +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;