10 files changed, 81 insertions, 49 deletions

diff --git a/drivers/block/Kconfig.iosched b/drivers/block/Kconfig.iosched
index 6070a480600b..5b90d2fa63b8 100644
--- a/drivers/block/Kconfig.iosched
+++ b/drivers/block/Kconfig.iosched
@@ -38,4 +38,32 @@ config IOSCHED_CFQ
 	  among all processes in the system. It should provide a fair
 	  working environment, suitable for desktop systems.
 
+choice
+	prompt "Default I/O scheduler"
+	default DEFAULT_AS
+	help
+	  Select the I/O scheduler which will be used by default for all
+	  block devices.
+
+	config DEFAULT_AS
+		bool "Anticipatory" if IOSCHED_AS
+
+	config DEFAULT_DEADLINE
+		bool "Deadline" if IOSCHED_DEADLINE
+
+	config DEFAULT_CFQ
+		bool "CFQ" if IOSCHED_CFQ
+
+	config DEFAULT_NOOP
+		bool "No-op"
+
+endchoice
+
+config DEFAULT_IOSCHED
+	string
+	default "anticipatory" if DEFAULT_AS
+	default "deadline" if DEFAULT_DEADLINE
+	default "cfq" if DEFAULT_CFQ
+	default "noop" if DEFAULT_NOOP
+
 endmenu
diff --git a/drivers/block/as-iosched.c b/drivers/block/as-iosched.c
index 4081c36c8c19..c6744ff38294 100644
--- a/drivers/block/as-iosched.c
+++ b/drivers/block/as-iosched.c
@@ -1344,6 +1344,7 @@ as_add_aliased_request(struct as_data *ad, struct as_rq *arq, struct as_rq *alia
 	 * Don't want to have to handle merges.
 	 */
 	as_del_arq_hash(arq);
+	arq->request->flags |= REQ_NOMERGE;
 }
 
 /*
@@ -1972,8 +1973,8 @@ static int __init as_init(void)
 
 static void __exit as_exit(void)
 {
-	kmem_cache_destroy(arq_pool);
 	elv_unregister(&iosched_as);
+	kmem_cache_destroy(arq_pool);
 }
 
 module_init(as_init);
diff --git a/drivers/block/cciss_scsi.c b/drivers/block/cciss_scsi.c
index e183a3ef7839..ec27976a57da 100644
--- a/drivers/block/cciss_scsi.c
+++ b/drivers/block/cciss_scsi.c
@@ -28,13 +28,17 @@
    through the array controller.  Note in particular, neither 
    physical nor logical disks are presented through the scsi layer. */
 
+#include <linux/timer.h>
+#include <linux/completion.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include <asm/atomic.h>
+
 #include <scsi/scsi.h> 
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_host.h> 
-#include <asm/atomic.h>
-#include <linux/timer.h>
-#include <linux/completion.h>
 
 #include "cciss_scsi.h"
 
diff --git a/drivers/block/cfq-iosched.c b/drivers/block/cfq-iosched.c
index 94690e4d41e0..5281f8e70510 100644
--- a/drivers/block/cfq-iosched.c
+++ b/drivers/block/cfq-iosched.c
@@ -2418,28 +2418,8 @@ static int __init cfq_init(void)
 
 static void __exit cfq_exit(void)
 {
-	struct task_struct *g, *p;
-	unsigned long flags;
-
-	read_lock_irqsave(&tasklist_lock, flags);
-
-	/*
-	 * iterate each process in the system, removing our io_context
-	 */
-	do_each_thread(g, p) {
-		struct io_context *ioc = p->io_context;
-
-		if (ioc && ioc->cic) {
-			ioc->cic->exit(ioc->cic);
-			cfq_free_io_context(ioc->cic);
-			ioc->cic = NULL;
-		}
-	} while_each_thread(g, p);
-
-	read_unlock_irqrestore(&tasklist_lock, flags);
-
-	cfq_slab_kill();
 	elv_unregister(&iosched_cfq);
+	cfq_slab_kill();
 }
 
 module_init(cfq_init);
diff --git a/drivers/block/elevator.c b/drivers/block/elevator.c
index 55621d5c5774..36f1057084b0 100644
--- a/drivers/block/elevator.c
+++ b/drivers/block/elevator.c
@@ -147,24 +147,17 @@ static void elevator_setup_default(void)
 	struct elevator_type *e;
 
 	/*
-	 * check if default is set and exists
+	 * If default has not been set, use the compiled-in selection.
 	 */
-	if (chosen_elevator[0] && (e = elevator_get(chosen_elevator))) {
-		elevator_put(e);
-		return;
-	}
+	if (!chosen_elevator[0])
+		strcpy(chosen_elevator, CONFIG_DEFAULT_IOSCHED);
 
-#if defined(CONFIG_IOSCHED_AS)
-	strcpy(chosen_elevator, "anticipatory");
-#elif defined(CONFIG_IOSCHED_DEADLINE)
-	strcpy(chosen_elevator, "deadline");
-#elif defined(CONFIG_IOSCHED_CFQ)
-	strcpy(chosen_elevator, "cfq");
-#elif defined(CONFIG_IOSCHED_NOOP)
-	strcpy(chosen_elevator, "noop");
-#else
-#error "You must build at least 1 IO scheduler into the kernel"
-#endif
+ 	/*
+ 	 * If the given scheduler is not available, fall back to no-op.
+ 	 */
+ 	if (!(e = elevator_find(chosen_elevator)))
+ 		strcpy(chosen_elevator, "noop");
+	elevator_put(e);
 }
 
 static int __init elevator_setup(char *str)
@@ -642,6 +635,27 @@ EXPORT_SYMBOL_GPL(elv_register);
 
 void elv_unregister(struct elevator_type *e)
 {
+	struct task_struct *g, *p;
+
+	/*
+	 * Iterate every thread in the process to remove the io contexts.
+	 */
+	read_lock(&tasklist_lock);
+	do_each_thread(g, p) {
+		struct io_context *ioc = p->io_context;
+		if (ioc && ioc->cic) {
+			ioc->cic->exit(ioc->cic);
+			ioc->cic->dtor(ioc->cic);
+			ioc->cic = NULL;
+		}
+		if (ioc && ioc->aic) {
+			ioc->aic->exit(ioc->aic);
+			ioc->aic->dtor(ioc->aic);
+			ioc->aic = NULL;
+		}
+	} while_each_thread(g, p);
+	read_unlock(&tasklist_lock);
+
 	spin_lock_irq(&elv_list_lock);
 	list_del_init(&e->list);
 	spin_unlock_irq(&elv_list_lock);
@@ -739,8 +753,10 @@ ssize_t elv_iosched_store(request_queue_t *q, const char *name, size_t count)
 		return -EINVAL;
 	}
 
-	if (!strcmp(elevator_name, q->elevator->elevator_type->elevator_name))
+	if (!strcmp(elevator_name, q->elevator->elevator_type->elevator_name)) {
+		elevator_put(e);
 		return count;
+	}
 
 	elevator_switch(q, e);
 	return count;
diff --git a/drivers/block/paride/paride.c b/drivers/block/paride/paride.c
index 1fef136c0e41..ce94aa11f6a7 100644
--- a/drivers/block/paride/paride.c
+++ b/drivers/block/paride/paride.c
@@ -29,6 +29,7 @@
 #include <linux/string.h>
 #include <linux/spinlock.h>
 #include <linux/wait.h>
+#include <linux/sched.h>	/* TASK_* */
 
 #ifdef CONFIG_PARPORT_MODULE
 #define CONFIG_PARPORT
diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c
index 94af920465b5..e9746af29b9f 100644
--- a/drivers/block/paride/pf.c
+++ b/drivers/block/paride/pf.c
@@ -807,10 +807,6 @@ static int pf_next_buf(void)
 		return 1;
 	spin_lock_irqsave(&pf_spin_lock, saved_flags);
 	pf_end_request(1);
-	if (pf_req) {
-		pf_count = pf_req->current_nr_sectors;
-		pf_buf = pf_req->buffer;
-	}
 	spin_unlock_irqrestore(&pf_spin_lock, saved_flags);
 	return 1;
 }
diff --git a/drivers/block/paride/pg.c b/drivers/block/paride/pg.c
index 82f2d6d2eeef..6f5df0fad703 100644
--- a/drivers/block/paride/pg.c
+++ b/drivers/block/paride/pg.c
@@ -162,6 +162,8 @@ enum {D_PRT, D_PRO, D_UNI, D_MOD, D_SLV, D_DLY};
 #include <linux/mtio.h>
 #include <linux/pg.h>
 #include <linux/device.h>
+#include <linux/sched.h>	/* current, TASK_* */
+#include <linux/jiffies.h>
 
 #include <asm/uaccess.h>
 
diff --git a/drivers/block/paride/pt.c b/drivers/block/paride/pt.c
index 686c95573452..715ae5dc88fb 100644
--- a/drivers/block/paride/pt.c
+++ b/drivers/block/paride/pt.c
@@ -146,6 +146,7 @@ static int (*drives[4])[6] = {&drive0, &drive1, &drive2, &drive3};
 #include <linux/slab.h>
 #include <linux/mtio.h>
 #include <linux/device.h>
+#include <linux/sched.h>	/* current, TASK_*, schedule_timeout() */
 
 #include <asm/uaccess.h>
 
diff --git a/drivers/block/viodasd.c b/drivers/block/viodasd.c
index e46ecd23b3ac..709f809f79f1 100644
--- a/drivers/block/viodasd.c
+++ b/drivers/block/viodasd.c
@@ -778,13 +778,16 @@ static struct vio_device_id viodasd_device_table[] __devinitdata = {
 	{ "viodasd", "" },
 	{ "", "" }
 };
-
 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
+
 static struct vio_driver viodasd_driver = {
-	.name = "viodasd",
 	.id_table = viodasd_device_table,
 	.probe = viodasd_probe,
-	.remove = viodasd_remove
+	.remove = viodasd_remove,
+	.driver = {
+		.name = "viodasd",
+		.owner = THIS_MODULE,
+	}
 };
 
 /*