From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch converts the TCM_Loop virtual SCSI LLD fabric module to use
the new struct target_core_fabrics_ops->new_cmd_map() caller added in
commit f3b8d9dfe00. This allows TCM_Loop to do second stage setup of new
struct se_cmd descriptors directly within TCM processing thread context,
and allows us to drop it's internal per struct tcm_loop_hba->tl_hba_qobj and
->tl_kthread members.
This means that tcm_loop_processing_thread() processing of seperate
TCM_Loop HBA queue in kthreads now goes away, and the original
tcm_loop_execute_core_cmd() now becomes the TFO->new_cmd_map() caller at
tcm_loop_new_cmd_map(). This function is called directly from TCM backstore
processing thread context after se_cmd->transport_add_cmd_to_queue(se_cmd,
TRANSPORT_NEW_CMD_MAP) is invoked by tcm_loop_queuecommand() from within
interrupt context.
This has been tested so far in KVM guest v2.6.36-rc3 with TCM/FILEIO backstores
Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/tcm_loop/tcm_loop_configfs.c | 35 +-------
drivers/target/tcm_loop/tcm_loop_core.h | 2 -
drivers/target/tcm_loop/tcm_loop_fabric.c | 61 --------------
drivers/target/tcm_loop/tcm_loop_fabric.h | 2 -
drivers/target/tcm_loop/tcm_loop_fabric_scsi.c | 100 +++++++-----------------
drivers/target/tcm_loop/tcm_loop_fabric_scsi.h | 2 +-
6 files changed, 34 insertions(+), 168 deletions(-)
diff --git a/drivers/target/tcm_loop/tcm_loop_configfs.c b/drivers/target/tcm_loop/tcm_loop_configfs.c
index fa4d82a..dd60cbf 100644
--- a/drivers/target/tcm_loop/tcm_loop_configfs.c
+++ b/drivers/target/tcm_loop/tcm_loop_configfs.c
@@ -449,17 +449,6 @@ check_len:
snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
/*
- * Setup the tl_hba->tl_hba_qobj
- */
- tl_hba->tl_hba_qobj = kzalloc(sizeof(struct se_queue_obj), GFP_KERNEL);
- if (!(tl_hba->tl_hba_qobj)) {
- kfree(tl_hba);
- printk("Unable to allocate tl_hba->tl_hba_qobj\n");
- return ERR_PTR(-ENOMEM);
- }
- transport_init_queue_obj(tl_hba->tl_hba_qobj);
-
- /*
* Call device_register(tl_hba->dev) to register the emulated
* Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
* device_register() callbacks in tcm_loop_driver_probe()
@@ -469,19 +458,6 @@ check_len:
goto out;
sh = tl_hba->sh;
- /*
- * Start up the per struct Scsi_Host tcm_loop processing thread
- */
- tl_hba->tl_kthread = kthread_run(tcm_loop_processing_thread,
- (void *)tl_hba, "tcm_loop_%d", sh->host_no);
- if (IS_ERR(tl_hba->tl_kthread)) {
- printk(KERN_ERR "Unable to start tcm_loop kthread\n");
- device_unregister(&tl_hba->dev);
- ret = -ENOMEM;
- goto out;
- }
- wait_for_completion(&tl_hba->tl_hba_qobj->thread_create_comp);
-
tcm_loop_hba_no_cnt++;
printk(KERN_INFO "TCM_Loop_ConfigFS: Allocated emulated Target"
" %s Address: %s at Linux/SCSI Host ID: %d\n",
@@ -489,7 +465,6 @@ check_len:
return &tl_hba->tl_hba_wwn;
out:
- kfree(tl_hba->tl_hba_qobj);
kfree(tl_hba);
return ERR_PTR(ret);
}
@@ -500,12 +475,6 @@ void tcm_loop_drop_scsi_hba(
struct tcm_loop_hba *tl_hba = container_of(wwn,
struct tcm_loop_hba, tl_hba_wwn);
int host_no = tl_hba->sh->host_no;
-
- /*
- * Shutdown the per HBA tcm_loop processing kthread
- */
- kthread_stop(tl_hba->tl_kthread);
- wait_for_completion(&tl_hba->tl_hba_qobj->thread_done_comp);
/*
* Call device_unregister() on the original tl_hba->dev.
* tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
@@ -590,6 +559,10 @@ int tcm_loop_register_configfs(void)
* virtual memory address mappings
*/
fabric->tf_ops.alloc_cmd_iovecs = NULL;
+ /*
+ * 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_to_pool = &tcm_loop_deallocate_core_cmd;
fabric->tf_ops.release_cmd_direct = &tcm_loop_deallocate_core_cmd;
diff --git a/drivers/target/tcm_loop/tcm_loop_core.h b/drivers/target/tcm_loop/tcm_loop_core.h
index eaebe89..69906b7 100644
--- a/drivers/target/tcm_loop/tcm_loop_core.h
+++ b/drivers/target/tcm_loop/tcm_loop_core.h
@@ -69,8 +69,6 @@ struct tcm_loop_hba {
struct se_lun *tl_hba_lun;
struct se_port *tl_hba_lun_sep;
struct se_device_s *se_dev_hba_ptr;
- struct se_queue_obj *tl_hba_qobj;
- struct task_struct *tl_kthread;
struct tcm_loop_nexus *tl_nexus;
struct device dev;
struct Scsi_Host *sh;
diff --git a/drivers/target/tcm_loop/tcm_loop_fabric.c b/drivers/target/tcm_loop/tcm_loop_fabric.c
index ef23f07..abd643d 100644
--- a/drivers/target/tcm_loop/tcm_loop_fabric.c
+++ b/drivers/target/tcm_loop/tcm_loop_fabric.c
@@ -455,67 +455,6 @@ u64 tcm_loop_pack_lun(unsigned int lun)
return cpu_to_le64(result);
}
-static struct se_queue_req *tcm_loop_get_qr_from_queue(struct se_queue_obj *qobj)
-{
- struct se_queue_req *qr;
- unsigned long flags;
-
- spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
- if (list_empty(&qobj->qobj_list)) {
- spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
- return NULL;
- }
-
- qr = list_first_entry(&qobj->qobj_list, struct se_queue_req, qr_list);
- list_del(&qr->qr_list);
- atomic_dec(&qobj->queue_cnt);
- spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
-
- return qr;
-}
-
-int tcm_loop_processing_thread(void *p)
-{
- struct scsi_cmnd *sc;
- struct tcm_loop_cmd *tl_cmd;
- struct tcm_loop_hba *tl_hba = (struct tcm_loop_hba *)p;
- struct se_queue_obj *qobj = tl_hba->tl_hba_qobj;
- struct se_queue_req *qr;
- int ret;
-
- current->policy = SCHED_NORMAL;
- set_user_nice(current, -20);
- spin_lock_irq(¤t->sighand->siglock);
- siginitsetinv(¤t->blocked, SHUTDOWN_SIGS);
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
-
- complete(&qobj->thread_create_comp);
-
- while (!(kthread_should_stop())) {
- ret = wait_event_interruptible(qobj->thread_wq,
- atomic_read(&qobj->queue_cnt) || kthread_should_stop());
- if (ret < 0)
- goto out;
-
- qr = tcm_loop_get_qr_from_queue(qobj);
- if (!(qr))
- continue;
-
- tl_cmd = (struct tcm_loop_cmd *)qr->cmd;
- sc = tl_cmd->sc;
- kfree(qr);
-
- TL_CDB_DEBUG("processing_thread, calling tcm_loop_execute"
- "_core_cmd() for tl_cmd: %p, sc: %p\n", tl_cmd, sc);
- tcm_loop_execute_core_cmd(tl_cmd, sc);
- }
-
-out:
- complete(&qobj->thread_done_comp);
- return 0;
-}
-
static int __init tcm_loop_fabric_init(void)
{
int ret;
diff --git a/drivers/target/tcm_loop/tcm_loop_fabric.h b/drivers/target/tcm_loop/tcm_loop_fabric.h
index dde23c5..eef5165 100644
--- a/drivers/target/tcm_loop/tcm_loop_fabric.h
+++ b/drivers/target/tcm_loop/tcm_loop_fabric.h
@@ -41,5 +41,3 @@ extern int tcm_loop_queue_tm_rsp(struct se_cmd *);
extern u16 tcm_loop_set_fabric_sense_len(struct se_cmd *, u32);
extern u16 tcm_loop_get_fabric_sense_len(void);
extern u64 tcm_loop_pack_lun(unsigned int);
-
-extern int tcm_loop_processing_thread(void *);
diff --git a/drivers/target/tcm_loop/tcm_loop_fabric_scsi.c b/drivers/target/tcm_loop/tcm_loop_fabric_scsi.c
index 126f311..78476bc 100644
--- a/drivers/target/tcm_loop/tcm_loop_fabric_scsi.c
+++ b/drivers/target/tcm_loop/tcm_loop_fabric_scsi.c
@@ -54,12 +54,13 @@
*
* Can be called from interrupt context in tcm_loop_queuecommand() below
*/
-static struct tcm_loop_cmd *tcm_loop_allocate_core_cmd(
+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,
int data_direction)
{
+ 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;
@@ -109,62 +110,37 @@ static struct tcm_loop_cmd *tcm_loop_allocate_core_cmd(
kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
return NULL;
}
-
- return tl_cmd;
-}
-
-/*
- * Queue up the newly allocated struct tcm_loop_cmd to be processed by
- * tcm_loop_fabri.c:tcm_loop_processing_thread()
- *
- * Can be called from interrupt context in tcm_loop_queuecommand() below
- */
-static int tcm_loop_queue_core_cmd(
- struct se_queue_obj *qobj,
- struct tcm_loop_cmd *tl_cmd)
-{
- struct se_queue_req *qr;
- unsigned long flags;
-
- qr = kzalloc(sizeof(struct se_queue_req), GFP_ATOMIC);
- if (!(qr)) {
- printk(KERN_ERR "Unable to allocate memory for"
- " struct se_queue_req\n");
- return -1;
+ se_cmd = tl_cmd->tl_se_cmd;
+ /*
+ * Locate the struct se_lun pointer and attach it to struct se_cmd
+ */
+ if (transport_get_lun_for_cmd(se_cmd, NULL,
+ tl_cmd->sc->device->lun) < 0) {
+ /* NON_EXISTENT_LUN */
+ transport_send_check_condition_and_sense(se_cmd,
+ se_cmd->scsi_sense_reason, 0);
+ return 0;
}
- INIT_LIST_HEAD(&qr->qr_list);
-
- qr->cmd = (void *)tl_cmd;
- spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
- list_add_tail(&qr->qr_list, &qobj->qobj_list);
- spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
+ /*
+ * Make early call to setup se_cmd->transport_add_cmd_to_queue() pointer
+ */
+ transport_device_setup_cmd(se_cmd);
- atomic_inc(&qobj->queue_cnt);
- wake_up_interruptible(&qobj->thread_wq);
- return 0;
+ return se_cmd;
}
/*
- * Called by tcm_loop_processing_thread() in tcm_loop_fabric.c
+ * Called by struct target_core_fabric_ops->new_cmd_map()
*
* Always called in process context
*/
-int tcm_loop_execute_core_cmd(struct tcm_loop_cmd *tl_cmd, struct scsi_cmnd *sc)
+int tcm_loop_new_cmd_map(struct se_cmd *se_cmd)
{
- struct se_cmd *se_cmd = tl_cmd->tl_se_cmd;
+ struct tcm_loop_cmd *tl_cmd = se_cmd->se_fabric_cmd_ptr;
+ struct scsi_cmnd *sc = tl_cmd->sc;
void *mem_ptr;
int ret;
/*
- * Locate the struct se_lun pointer and attach it to struct se_cmd
- */
- if (transport_get_lun_for_cmd(se_cmd, NULL,
- tl_cmd->sc->device->lun) < 0) {
- /* NON_EXISTENT_LUN */
- transport_send_check_condition_and_sense(se_cmd,
- se_cmd->scsi_sense_reason, 0);
- return 0;
- }
- /*
* Allocate the necessary tasks to complete the received CDB+data
*/
ret = transport_generic_allocate_tasks(se_cmd, tl_cmd->sc->cmnd);
@@ -213,11 +189,8 @@ int tcm_loop_execute_core_cmd(struct tcm_loop_cmd *tl_cmd, struct scsi_cmnd *sc)
TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
return 0;
}
- /*
- * Queue up the struct se_cmd + tasks to be processed by the
- * TCM storage object.
- */
- return transport_generic_handle_cdb(se_cmd);
+
+ return 0;
}
/*
@@ -333,9 +306,9 @@ static int tcm_loop_queuecommand(
struct scsi_cmnd *sc,
void (*done)(struct scsi_cmnd *))
{
+ struct se_cmd *se_cmd;
struct se_portal_group *se_tpg;
struct Scsi_Host *host = sc->device->host;
- struct tcm_loop_cmd *tl_cmd;
struct tcm_loop_hba *tl_hba;
struct tcm_loop_tpg *tl_tpg;
int data_direction;
@@ -380,31 +353,17 @@ static int tcm_loop_queuecommand(
* Determine the SAM Task Attribute and allocate tl_cmd and
* tl_cmd->tl_se_cmd from TCM infrastructure
*/
- tl_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc, data_direction);
- if (!(tl_cmd)) {
+ se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc, data_direction);
+ if (!(se_cmd)) {
spin_lock_irq(host->host_lock);
sc->result = host_byte(DID_ERROR);
(*done)(sc);
return 0;
}
/*
- * Queue the tl_cmd to be executed in process context by the
- * tcm_loop kernel thread
- */
- if (tcm_loop_queue_core_cmd(tl_hba->tl_hba_qobj, tl_cmd) < 0) {
- /*
- * Will free both struct tcm_loop_cmd and struct se_cmd
- */
- transport_release_cmd_to_pool(tl_cmd->tl_se_cmd);
- /*
- * Reaquire the struct scsi_host->host_lock, and
- * complete the struct scsi_cmnd
- */
- spin_lock_irq(host->host_lock);
- sc->result = host_byte(DID_ERROR);
- (*done)(sc);
- return 0;
- }
+ * Queue up the newly allocated to be processed in TCM thread context.
+ */
+ se_cmd->transport_add_cmd_to_queue(se_cmd, TRANSPORT_NEW_CMD_MAP);
/*
* Reaquire the the struct scsi_host->host_lock before returning
*/
@@ -585,7 +544,6 @@ static void tcm_loop_release_adapter(struct device *dev)
{
struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
- kfree(tl_hba->tl_hba_qobj);
kfree(tl_hba);
}
diff --git a/drivers/target/tcm_loop/tcm_loop_fabric_scsi.h b/drivers/target/tcm_loop/tcm_loop_fabric_scsi.h
index c93e610..bcba89b 100644
--- a/drivers/target/tcm_loop/tcm_loop_fabric_scsi.h
+++ b/drivers/target/tcm_loop/tcm_loop_fabric_scsi.h
@@ -1,6 +1,6 @@
extern struct kmem_cache *tcm_loop_cmd_cache;
-extern int tcm_loop_execute_core_cmd(struct tcm_loop_cmd *, struct scsi_cmnd *);
+extern int tcm_loop_new_cmd_map(struct se_cmd *);
extern void tcm_loop_check_stop_free(struct se_cmd *);
extern void tcm_loop_deallocate_core_cmd(struct se_cmd *);
extern void tcm_loop_scsi_forget_host(struct Scsi_Host *);
--
1.5.6.5
--
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