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authorNicholas Bellinger2011-11-30 10:25:21 +0100
committerNicholas Bellinger2011-12-14 12:42:13 +0100
commit65586d51e0986be574118286c3d0007e903a2add (patch)
tree0684f76d53e666ffe2a2c77f8e3947d263fa1b75 /drivers/target/target_core_transport.c
parenttarget: Fix possible NULL pointer with __transport_execute_tasks (diff)
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target: Drop se_device TCQ queue_depth usage from I/O path
Historically, pSCSI devices have been the ones that required target-core to enforce a per se_device->depth_left. This patch changes target-core to no longer (by default) enforce a per se_device->depth_left or sleep in transport_tcq_window_closed() when we out of queue slots for all backend export cases. Cc: Christoph Hellwig <hch@lst.de> Cc: Roland Dreier <roland@purestorage.com> Cc: Joern Engel <joern@logfs.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/target_core_transport.c')
-rw-r--r--drivers/target/target_core_transport.c39
1 files changed, 2 insertions, 37 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 1cc7e920ab0b..7c2def7e2593 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -691,12 +691,6 @@ void transport_complete_task(struct se_task *task, int success)
struct se_cmd *cmd = task->task_se_cmd;
struct se_device *dev = cmd->se_dev;
unsigned long flags;
-#if 0
- pr_debug("task: %p CDB: 0x%02x obj_ptr: %p\n", task,
- cmd->t_task_cdb[0], dev);
-#endif
- if (dev)
- atomic_inc(&dev->depth_left);
spin_lock_irqsave(&cmd->t_state_lock, flags);
task->task_flags &= ~TF_ACTIVE;
@@ -971,9 +965,8 @@ void transport_dump_dev_state(
break;
}
- *bl += sprintf(b + *bl, " Execute/Left/Max Queue Depth: %d/%d/%d",
- atomic_read(&dev->execute_tasks), atomic_read(&dev->depth_left),
- dev->queue_depth);
+ *bl += sprintf(b + *bl, " Execute/Max Queue Depth: %d/%d",
+ atomic_read(&dev->execute_tasks), dev->queue_depth);
*bl += sprintf(b + *bl, " SectorSize: %u MaxSectors: %u\n",
dev->se_sub_dev->se_dev_attrib.block_size, dev->se_sub_dev->se_dev_attrib.max_sectors);
*bl += sprintf(b + *bl, " ");
@@ -1328,9 +1321,6 @@ struct se_device *transport_add_device_to_core_hba(
spin_lock_init(&dev->se_port_lock);
spin_lock_init(&dev->se_tmr_lock);
spin_lock_init(&dev->qf_cmd_lock);
-
- dev->queue_depth = dev_limits->queue_depth;
- atomic_set(&dev->depth_left, dev->queue_depth);
atomic_set(&dev->dev_ordered_id, 0);
se_dev_set_default_attribs(dev, dev_limits);
@@ -1982,18 +1972,6 @@ static void transport_set_supported_SAM_opcode(struct se_cmd *se_cmd)
spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
}
-static inline int transport_tcq_window_closed(struct se_device *dev)
-{
- if (dev->dev_tcq_window_closed++ <
- PYX_TRANSPORT_WINDOW_CLOSED_THRESHOLD) {
- msleep(PYX_TRANSPORT_WINDOW_CLOSED_WAIT_SHORT);
- } else
- msleep(PYX_TRANSPORT_WINDOW_CLOSED_WAIT_LONG);
-
- wake_up_interruptible(&dev->dev_queue_obj.thread_wq);
- return 0;
-}
-
/*
* Called from Fabric Module context from transport_execute_tasks()
*
@@ -2126,16 +2104,7 @@ static int __transport_execute_tasks(struct se_device *dev)
struct se_task *task = NULL;
unsigned long flags;
- /*
- * Check if there is enough room in the device and HBA queue to send
- * struct se_tasks to the selected transport.
- */
check_depth:
- if (!atomic_read(&dev->depth_left))
- return transport_tcq_window_closed(dev);
-
- dev->dev_tcq_window_closed = 0;
-
spin_lock_irq(&dev->execute_task_lock);
if (list_empty(&dev->execute_task_list)) {
spin_unlock_irq(&dev->execute_task_lock);
@@ -2146,10 +2115,7 @@ check_depth:
__transport_remove_task_from_execute_queue(task, dev);
spin_unlock_irq(&dev->execute_task_lock);
- atomic_dec(&dev->depth_left);
-
cmd = task->task_se_cmd;
-
spin_lock_irqsave(&cmd->t_state_lock, flags);
task->task_flags |= (TF_ACTIVE | TF_SENT);
atomic_inc(&cmd->t_task_cdbs_sent);
@@ -2170,7 +2136,6 @@ check_depth:
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
atomic_set(&cmd->t_transport_sent, 0);
transport_stop_tasks_for_cmd(cmd);
- atomic_inc(&dev->depth_left);
transport_generic_request_failure(cmd);
}