修改4g拨号为QMI,需要在系统里后台执行quectel-CM

hc

2024-10-22 8ac6c7a54ed1b98d142dce24b11c6de6a1e239a5

 kernel/block/blk-ioc.c
..
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@@ -9,7 +9,6 @@
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 #include <linux/blkdev.h>
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 #include <linux/slab.h>
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 #include <linux/sched/task.h>
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-#include <linux/delay.h>
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 #include "blk.h"
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14
 
..
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@@ -29,7 +28,6 @@
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 	BUG_ON(atomic_long_read(&ioc->refcount) <= 0);
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 	atomic_long_inc(&ioc->refcount);
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 }
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-EXPORT_SYMBOL(get_io_context);
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31
 
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 static void icq_free_icq_rcu(struct rcu_head *head)
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 {
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@@ -49,10 +47,8 @@
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 	if (icq->flags & ICQ_EXITED)
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 		return;
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-	if (et->uses_mq && et->ops.mq.exit_icq)
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-		et->ops.mq.exit_icq(icq);
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-	else if (!et->uses_mq && et->ops.sq.elevator_exit_icq_fn)
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-		et->ops.sq.elevator_exit_icq_fn(icq);
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+	if (et->ops.exit_icq)
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+		et->ops.exit_icq(icq);
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52
 
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 	icq->flags |= ICQ_EXITED;
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 }
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@@ -100,32 +96,38 @@
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 {
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 	struct io_context *ioc = container_of(work, struct io_context,
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 					      release_work);
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-	unsigned long flags;
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-
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-	/*
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-	 * Exiting icq may call into put_io_context() through elevator
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-	 * which will trigger lockdep warning.  The ioc's are guaranteed to
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-	 * be different, use a different locking subclass here.  Use
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-	 * irqsave variant as there's no spin_lock_irq_nested().
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-	 */
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-	spin_lock_irqsave_nested(&ioc->lock, flags, 1);
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+	spin_lock_irq(&ioc->lock);
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 	while (!hlist_empty(&ioc->icq_list)) {
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 		struct io_cq *icq = hlist_entry(ioc->icq_list.first,
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 						struct io_cq, ioc_node);
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 		struct request_queue *q = icq->q;
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-		if (spin_trylock(q->queue_lock)) {
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+		if (spin_trylock(&q->queue_lock)) {
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 			ioc_destroy_icq(icq);
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-			spin_unlock(q->queue_lock);
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+			spin_unlock(&q->queue_lock);
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 		} else {
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-			spin_unlock_irqrestore(&ioc->lock, flags);
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-			cpu_chill();
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-			spin_lock_irqsave_nested(&ioc->lock, flags, 1);
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+			/* Make sure q and icq cannot be freed. */
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+			rcu_read_lock();
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+
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+			/* Re-acquire the locks in the correct order. */
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+			spin_unlock(&ioc->lock);
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+			spin_lock(&q->queue_lock);
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+			spin_lock(&ioc->lock);
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+
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+			/*
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+			 * The icq may have been destroyed when the ioc lock
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+			 * was released.
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+			 */
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+			if (!(icq->flags & ICQ_DESTROYED))
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+				ioc_destroy_icq(icq);
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+
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+			spin_unlock(&q->queue_lock);
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+			rcu_read_unlock();
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 		}
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 	}
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-	spin_unlock_irqrestore(&ioc->lock, flags);
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+	spin_unlock_irq(&ioc->lock);
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 	kmem_cache_free(iocontext_cachep, ioc);
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 }
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@@ -164,7 +166,6 @@
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 	if (free_ioc)
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 		kmem_cache_free(iocontext_cachep, ioc);
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 }
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-EXPORT_SYMBOL(put_io_context);
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 /**
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  * put_io_context_active - put active reference on ioc
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@@ -175,8 +176,6 @@
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  */
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 void put_io_context_active(struct io_context *ioc)
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 {
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-	struct elevator_type *et;
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-	unsigned long flags;
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 	struct io_cq *icq;
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 	if (!atomic_dec_and_test(&ioc->active_ref)) {
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@@ -184,32 +183,14 @@
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 		return;
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 	}
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-	/*
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-	 * Need ioc lock to walk icq_list and q lock to exit icq.  Perform
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-	 * reverse double locking.  Read comment in ioc_release_fn() for
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-	 * explanation on the nested locking annotation.
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-	 */
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-retry:
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-	spin_lock_irqsave_nested(&ioc->lock, flags, 1);
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+	spin_lock_irq(&ioc->lock);
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 	hlist_for_each_entry(icq, &ioc->icq_list, ioc_node) {
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 		if (icq->flags & ICQ_EXITED)
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 			continue;
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-		et = icq->q->elevator->type;
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-		if (et->uses_mq) {
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-			ioc_exit_icq(icq);
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-		} else {
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-			if (spin_trylock(icq->q->queue_lock)) {
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-				ioc_exit_icq(icq);
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-				spin_unlock(icq->q->queue_lock);
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-			} else {
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-				spin_unlock_irqrestore(&ioc->lock, flags);
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-				cpu_chill();
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-				goto retry;
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-			}
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-		}
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+		ioc_exit_icq(icq);
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 	}
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-	spin_unlock_irqrestore(&ioc->lock, flags);
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+	spin_unlock_irq(&ioc->lock);
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 	put_io_context(ioc);
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 }
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@@ -235,7 +216,7 @@
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 	rcu_read_lock();
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 	while (!list_empty(icq_list)) {
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 		struct io_cq *icq = list_entry(icq_list->next,
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-					       struct io_cq, q_node);
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+						struct io_cq, q_node);
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 		struct io_context *ioc = icq->ioc;
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 		spin_lock_irqsave(&ioc->lock, flags);
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@@ -259,16 +240,11 @@
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 {
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 	LIST_HEAD(icq_list);
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-	spin_lock_irq(q->queue_lock);
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+	spin_lock_irq(&q->queue_lock);
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 	list_splice_init(&q->icq_list, &icq_list);
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+	spin_unlock_irq(&q->queue_lock);
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-	if (q->mq_ops) {
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-		spin_unlock_irq(q->queue_lock);
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-		__ioc_clear_queue(&icq_list);
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-	} else {
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-		__ioc_clear_queue(&icq_list);
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-		spin_unlock_irq(q->queue_lock);
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-	}
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+	__ioc_clear_queue(&icq_list);
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 }
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 int create_task_io_context(struct task_struct *task, gfp_t gfp_flags, int node)
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@@ -344,7 +320,6 @@
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 	return NULL;
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 }
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-EXPORT_SYMBOL(get_task_io_context);
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 /**
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  * ioc_lookup_icq - lookup io_cq from ioc
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@@ -358,7 +333,7 @@
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 {
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 	struct io_cq *icq;
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-	lockdep_assert_held(q->queue_lock);
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+	lockdep_assert_held(&q->queue_lock);
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 	/*
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 	 * icq's are indexed from @ioc using radix tree and hint pointer,
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@@ -417,16 +392,14 @@
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 	INIT_HLIST_NODE(&icq->ioc_node);
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 	/* lock both q and ioc and try to link @icq */
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-	spin_lock_irq(q->queue_lock);
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+	spin_lock_irq(&q->queue_lock);
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 	spin_lock(&ioc->lock);
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 	if (likely(!radix_tree_insert(&ioc->icq_tree, q->id, icq))) {
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 		hlist_add_head(&icq->ioc_node, &ioc->icq_list);
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 		list_add(&icq->q_node, &q->icq_list);
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-		if (et->uses_mq && et->ops.mq.init_icq)
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-			et->ops.mq.init_icq(icq);
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-		else if (!et->uses_mq && et->ops.sq.elevator_init_icq_fn)
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-			et->ops.sq.elevator_init_icq_fn(icq);
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+		if (et->ops.init_icq)
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+			et->ops.init_icq(icq);
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 	} else {
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 		kmem_cache_free(et->icq_cache, icq);
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 		icq = ioc_lookup_icq(ioc, q);
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@@ -435,7 +408,7 @@
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 	}
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 	spin_unlock(&ioc->lock);
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-	spin_unlock_irq(q->queue_lock);
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+	spin_unlock_irq(&q->queue_lock);
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 	radix_tree_preload_end();
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 	return icq;
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 }