Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 159 insertions, 204 deletions

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index c47ff7f59e5..a9b4eeefe9f 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -44,138 +44,12 @@
 /* Local pointer to allocated TCM configfs fabric module */
 static struct target_fabric_configfs *tcm_loop_fabric_configfs;
 
+static struct workqueue_struct *tcm_loop_workqueue;
 static struct kmem_cache *tcm_loop_cmd_cache;
 
 static int tcm_loop_hba_no_cnt;
 
-/*
- * Allocate a tcm_loop cmd descriptor from target_core_mod code
- *
- * Can be called from interrupt context in tcm_loop_queuecommand() below
- */
-static struct se_cmd *tcm_loop_allocate_core_cmd(
-	struct tcm_loop_hba *tl_hba,
-	struct se_portal_group *se_tpg,
-	struct scsi_cmnd *sc)
-{
-	struct se_cmd *se_cmd;
-	struct se_session *se_sess;
-	struct tcm_loop_nexus *tl_nexus = tl_hba->tl_nexus;
-	struct tcm_loop_cmd *tl_cmd;
-	int sam_task_attr;
-
-	if (!tl_nexus) {
-		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
-				" does not exist\n");
-		set_host_byte(sc, DID_ERROR);
-		return NULL;
-	}
-	se_sess = tl_nexus->se_sess;
-
-	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
-	if (!tl_cmd) {
-		pr_err("Unable to allocate struct tcm_loop_cmd\n");
-		set_host_byte(sc, DID_ERROR);
-		return NULL;
-	}
-	se_cmd = &tl_cmd->tl_se_cmd;
-	/*
-	 * Save the pointer to struct scsi_cmnd *sc
-	 */
-	tl_cmd->sc = sc;
-	/*
-	 * Locate the SAM Task Attr from struct scsi_cmnd *
-	 */
-	if (sc->device->tagged_supported) {
-		switch (sc->tag) {
-		case HEAD_OF_QUEUE_TAG:
-			sam_task_attr = MSG_HEAD_TAG;
-			break;
-		case ORDERED_QUEUE_TAG:
-			sam_task_attr = MSG_ORDERED_TAG;
-			break;
-		default:
-			sam_task_attr = MSG_SIMPLE_TAG;
-			break;
-		}
-	} else
-		sam_task_attr = MSG_SIMPLE_TAG;
-
-	/*
-	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
-	 */
-	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
-			scsi_bufflen(sc), sc->sc_data_direction, sam_task_attr,
-			&tl_cmd->tl_sense_buf[0]);
-
-	if (scsi_bidi_cmnd(sc))
-		se_cmd->se_cmd_flags |= SCF_BIDI;
-
-	/*
-	 * Locate the struct se_lun pointer and attach it to struct se_cmd
-	 */
-	if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
-		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
-		set_host_byte(sc, DID_NO_CONNECT);
-		return NULL;
-	}
-
-	return se_cmd;
-}
-
-/*
- * Called by struct target_core_fabric_ops->new_cmd_map()
- *
- * Always called in process context.  A non zero return value
- * here will signal to handle an exception based on the return code.
- */
-static int tcm_loop_new_cmd_map(struct se_cmd *se_cmd)
-{
-	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
-				struct tcm_loop_cmd, tl_se_cmd);
-	struct scsi_cmnd *sc = tl_cmd->sc;
-	struct scatterlist *sgl_bidi = NULL;
-	u32 sgl_bidi_count = 0;
-	int ret;
-	/*
-	 * Allocate the necessary tasks to complete the received CDB+data
-	 */
-	ret = transport_generic_allocate_tasks(se_cmd, sc->cmnd);
-	if (ret != 0)
-		return ret;
-	/*
-	 * For BIDI commands, pass in the extra READ buffer
-	 * to transport_generic_map_mem_to_cmd() below..
-	 */
-	if (se_cmd->se_cmd_flags & SCF_BIDI) {
-		struct scsi_data_buffer *sdb = scsi_in(sc);
-
-		sgl_bidi = sdb->table.sgl;
-		sgl_bidi_count = sdb->table.nents;
-	}
-	/*
-	 * Because some userspace code via scsi-generic do not memset their
-	 * associated read buffers, go ahead and do that here for type
-	 * SCF_SCSI_CONTROL_SG_IO_CDB.  Also note that this is currently
-	 * guaranteed to be a single SGL for SCF_SCSI_CONTROL_SG_IO_CDB
-	 * by target core in transport_generic_allocate_tasks() ->
-	 * transport_generic_cmd_sequencer().
-	 */
-	if (se_cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB &&
-	    se_cmd->data_direction == DMA_FROM_DEVICE) {
-		struct scatterlist *sg = scsi_sglist(sc);
-		unsigned char *buf = kmap(sg_page(sg)) + sg->offset;
-
-		if (buf != NULL) {
-			memset(buf, 0, sg->length);
-			kunmap(sg_page(sg));
-		}
-	}
-
-	/* Tell the core about our preallocated memory */
-	return transport_generic_map_mem_to_cmd(se_cmd, scsi_sglist(sc),
-			scsi_sg_count(sc), sgl_bidi, sgl_bidi_count);
-}
+static int tcm_loop_queue_status(struct se_cmd *se_cmd);
 
 /*
  * Called from struct target_core_fabric_ops->check_stop_free()
@@ -187,7 +61,7 @@ static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
 	 * pointer.  These will be released directly in tcm_loop_device_reset()
 	 * with transport_generic_free_cmd().
 	 */
-	if (se_cmd->se_tmr_req)
+	if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
 		return 0;
 	/*
 	 * Release the struct se_cmd, which will make a callback to release
@@ -263,50 +137,152 @@ static int tcm_loop_change_queue_depth(
 }
 
 /*
- * Main entry point from struct scsi_host_template for incoming SCSI CDB+Data
- * from Linux/SCSI subsystem for SCSI low level device drivers (LLDs)
+ * Locate the SAM Task Attr from struct scsi_cmnd *
  */
-static int tcm_loop_queuecommand(
-	struct Scsi_Host *sh,
-	struct scsi_cmnd *sc)
+static int tcm_loop_sam_attr(struct scsi_cmnd *sc)
 {
-	struct se_cmd *se_cmd;
-	struct se_portal_group *se_tpg;
+	if (sc->device->tagged_supported) {
+		switch (sc->tag) {
+		case HEAD_OF_QUEUE_TAG:
+			return MSG_HEAD_TAG;
+		case ORDERED_QUEUE_TAG:
+			return MSG_ORDERED_TAG;
+		default:
+			break;
+		}
+	}
+
+	return MSG_SIMPLE_TAG;
+}
+
+static void tcm_loop_submission_work(struct work_struct *work)
+{
+	struct tcm_loop_cmd *tl_cmd =
+		container_of(work, struct tcm_loop_cmd, work);
+	struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
+	struct scsi_cmnd *sc = tl_cmd->sc;
+	struct tcm_loop_nexus *tl_nexus;
 	struct tcm_loop_hba *tl_hba;
 	struct tcm_loop_tpg *tl_tpg;
+	struct scatterlist *sgl_bidi = NULL;
+	u32 sgl_bidi_count = 0;
+	int ret;
 
-	pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
-		" scsi_buf_len: %u\n", sc->device->host->host_no,
-		sc->device->id, sc->device->channel, sc->device->lun,
-		sc->cmnd[0], scsi_bufflen(sc));
-	/*
-	 * Locate the tcm_loop_hba_t pointer
-	 */
 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
+
 	/*
 	 * Ensure that this tl_tpg reference from the incoming sc->device->id
 	 * has already been configured via tcm_loop_make_naa_tpg().
 	 */
 	if (!tl_tpg->tl_hba) {
 		set_host_byte(sc, DID_NO_CONNECT);
-		sc->scsi_done(sc);
-		return 0;
+		goto out_done;
 	}
-	se_tpg = &tl_tpg->tl_se_tpg;
+
+	tl_nexus = tl_hba->tl_nexus;
+	if (!tl_nexus) {
+		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
+				" does not exist\n");
+		set_host_byte(sc, DID_ERROR);
+		goto out_done;
+	}
+
+	transport_init_se_cmd(se_cmd, tl_tpg->tl_se_tpg.se_tpg_tfo,
+			tl_nexus->se_sess,
+			scsi_bufflen(sc), sc->sc_data_direction,
+			tcm_loop_sam_attr(sc), &tl_cmd->tl_sense_buf[0]);
+
+	if (scsi_bidi_cmnd(sc)) {
+		struct scsi_data_buffer *sdb = scsi_in(sc);
+
+		sgl_bidi = sdb->table.sgl;
+		sgl_bidi_count = sdb->table.nents;
+		se_cmd->se_cmd_flags |= SCF_BIDI;
+
+	}
+
+	if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
+		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
+		set_host_byte(sc, DID_NO_CONNECT);
+		goto out_done;
+	}
+
 	/*
-	 * Determine the SAM Task Attribute and allocate tl_cmd and
-	 * tl_cmd->tl_se_cmd from TCM infrastructure
+	 * Because some userspace code via scsi-generic do not memset their
+	 * associated read buffers, go ahead and do that here for type
+	 * SCF_SCSI_CONTROL_SG_IO_CDB.  Also note that this is currently
+	 * guaranteed to be a single SGL for SCF_SCSI_CONTROL_SG_IO_CDB
+	 * by target core in transport_generic_allocate_tasks() ->
+	 * transport_generic_cmd_sequencer().
 	 */
-	se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc);
-	if (!se_cmd) {
+	if (se_cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB &&
+	    se_cmd->data_direction == DMA_FROM_DEVICE) {
+		struct scatterlist *sg = scsi_sglist(sc);
+		unsigned char *buf = kmap(sg_page(sg)) + sg->offset;
+
+		if (buf != NULL) {
+			memset(buf, 0, sg->length);
+			kunmap(sg_page(sg));
+		}
+	}
+
+	ret = transport_generic_allocate_tasks(se_cmd, sc->cmnd);
+	if (ret == -ENOMEM) {
+		transport_send_check_condition_and_sense(se_cmd,
+				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
+		transport_generic_free_cmd(se_cmd, 0);
+		return;
+	} else if (ret < 0) {
+		if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
+			tcm_loop_queue_status(se_cmd);
+		else
+			transport_send_check_condition_and_sense(se_cmd,
+					se_cmd->scsi_sense_reason, 0);
+		transport_generic_free_cmd(se_cmd, 0);
+		return;
+	}
+
+	ret = transport_generic_map_mem_to_cmd(se_cmd, scsi_sglist(sc),
+			scsi_sg_count(sc), sgl_bidi, sgl_bidi_count);
+	if (ret) {
+		transport_send_check_condition_and_sense(se_cmd,
+					se_cmd->scsi_sense_reason, 0);
+		transport_generic_free_cmd(se_cmd, 0);
+		return;
+	}
+	transport_handle_cdb_direct(se_cmd);
+	return;
+
+out_done:
+	sc->scsi_done(sc);
+	return;
+}
+
+/*
+ * ->queuecommand can be and usually is called from interrupt context, so
+ * defer the actual submission to a workqueue.
+ */
+static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
+{
+	struct tcm_loop_cmd *tl_cmd;
+
+	pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
+		" scsi_buf_len: %u\n", sc->device->host->host_no,
+		sc->device->id, sc->device->channel, sc->device->lun,
+		sc->cmnd[0], scsi_bufflen(sc));
+
+	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
+	if (!tl_cmd) {
+		pr_err("Unable to allocate struct tcm_loop_cmd\n");
+		set_host_byte(sc, DID_ERROR);
 		sc->scsi_done(sc);
 		return 0;
 	}
-	/*
-	 * Queue up the newly allocated to be processed in TCM thread context.
-	*/
-	transport_generic_handle_cdb_map(se_cmd);
+
+	tl_cmd->sc = sc;
+	INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
+	queue_work(tcm_loop_workqueue, &tl_cmd->work);
 	return 0;
 }
 
@@ -324,7 +300,7 @@ static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 	struct tcm_loop_nexus *tl_nexus;
 	struct tcm_loop_tmr *tl_tmr = NULL;
 	struct tcm_loop_tpg *tl_tpg;
-	int ret = FAILED;
+	int ret = FAILED, rc;
 	/*
 	 * Locate the tcm_loop_hba_t pointer
 	 */
@@ -365,12 +341,9 @@ static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
 				DMA_NONE, MSG_SIMPLE_TAG,
 				&tl_cmd->tl_sense_buf[0]);
-	/*
-	 * Allocate the LUN_RESET TMR
-	 */
-	se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd, tl_tmr,
-						TMR_LUN_RESET, GFP_KERNEL);
-	if (IS_ERR(se_cmd->se_tmr_req))
+
+	rc = core_tmr_alloc_req(se_cmd, tl_tmr, TMR_LUN_RESET, GFP_KERNEL);
+	if (rc < 0)
 		goto release;
 	/*
 	 * Locate the underlying TCM struct se_lun from sc->device->lun
@@ -762,22 +735,6 @@ static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
 	return 1;
 }
 
-static int tcm_loop_is_state_remove(struct se_cmd *se_cmd)
-{
-	/*
-	 * Assume struct scsi_cmnd is not in remove state..
-	 */
-	return 0;
-}
-
-static int tcm_loop_sess_logged_in(struct se_session *se_sess)
-{
-	/*
-	 * Assume that TL Nexus is always active
-	 */
-	return 1;
-}
-
 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
 {
 	return 1;
@@ -811,19 +768,6 @@ static void tcm_loop_close_session(struct se_session *se_sess)
 	return;
 };
 
-static void tcm_loop_stop_session(
-	struct se_session *se_sess,
-	int sess_sleep,
-	int conn_sleep)
-{
-	return;
-}
-
-static void tcm_loop_fall_back_to_erl0(struct se_session *se_sess)
-{
-	return;
-}
-
 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
 {
 	/*
@@ -855,6 +799,9 @@ static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
 
 	sc->result = SAM_STAT_GOOD;
 	set_host_byte(sc, DID_OK);
+	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
+	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
+		scsi_set_resid(sc, se_cmd->residual_count);
 	sc->scsi_done(sc);
 	return 0;
 }
@@ -880,6 +827,9 @@ static int tcm_loop_queue_status(struct se_cmd *se_cmd)
 		sc->result = se_cmd->scsi_status;
 
 	set_host_byte(sc, DID_OK);
+	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
+	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
+		scsi_set_resid(sc, se_cmd->residual_count);
 	sc->scsi_done(sc);
 	return 0;
 }
@@ -1361,7 +1311,6 @@ static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
 static int tcm_loop_register_configfs(void)
 {
 	struct target_fabric_configfs *fabric;
-	struct config_group *tf_cg;
 	int ret;
 	/*
 	 * Set the TCM Loop HBA counter to zero
@@ -1407,14 +1356,10 @@ static int tcm_loop_register_configfs(void)
 	/*
 	 * Used for setting up remaining TCM resources in process context
 	 */
-	fabric->tf_ops.new_cmd_map = &tcm_loop_new_cmd_map;
 	fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
 	fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
 	fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
 	fabric->tf_ops.close_session = &tcm_loop_close_session;
-	fabric->tf_ops.stop_session = &tcm_loop_stop_session;
-	fabric->tf_ops.fall_back_to_erl0 = &tcm_loop_fall_back_to_erl0;
-	fabric->tf_ops.sess_logged_in = &tcm_loop_sess_logged_in;
 	fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
 	fabric->tf_ops.sess_get_initiator_sid = NULL;
 	fabric->tf_ops.write_pending = &tcm_loop_write_pending;
@@ -1431,9 +1376,7 @@ static int tcm_loop_register_configfs(void)
 	fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
 	fabric->tf_ops.set_fabric_sense_len = &tcm_loop_set_fabric_sense_len;
 	fabric->tf_ops.get_fabric_sense_len = &tcm_loop_get_fabric_sense_len;
-	fabric->tf_ops.is_state_remove = &tcm_loop_is_state_remove;
 
-	tf_cg = &fabric->tf_group;
 	/*
 	 * Setup function pointers for generic logic in target_core_fabric_configfs.c
 	 */
@@ -1490,7 +1433,11 @@ static void tcm_loop_deregister_configfs(void)
 
 static int __init tcm_loop_fabric_init(void)
 {
-	int ret;
+	int ret = -ENOMEM;
+
+	tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
+	if (!tcm_loop_workqueue)
+		goto out;
 
 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
 				sizeof(struct tcm_loop_cmd),
@@ -1499,20 +1446,27 @@ static int __init tcm_loop_fabric_init(void)
 	if (!tcm_loop_cmd_cache) {
 		pr_debug("kmem_cache_create() for"
 			" tcm_loop_cmd_cache failed\n");
-		return -ENOMEM;
+		goto out_destroy_workqueue;
 	}
 
 	ret = tcm_loop_alloc_core_bus();
 	if (ret)
-		return ret;
+		goto out_destroy_cache;
 
 	ret = tcm_loop_register_configfs();
-	if (ret) {
-		tcm_loop_release_core_bus();
-		return ret;
-	}
+	if (ret)
+		goto out_release_core_bus;
 
 	return 0;
+
+out_release_core_bus:
+	tcm_loop_release_core_bus();
+out_destroy_cache:
+	kmem_cache_destroy(tcm_loop_cmd_cache);
+out_destroy_workqueue:
+	destroy_workqueue(tcm_loop_workqueue);
+out:
+	return ret;
 }
 
 static void __exit tcm_loop_fabric_exit(void)
@@ -1520,6 +1474,7 @@ static void __exit tcm_loop_fabric_exit(void)
 	tcm_loop_deregister_configfs();
 	tcm_loop_release_core_bus();
 	kmem_cache_destroy(tcm_loop_cmd_cache);
+	destroy_workqueue(tcm_loop_workqueue);
 }
 
 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");