10 files changed, 80 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 564172234819..c6744ff38294 100644
--- a/drivers/block/as-iosched.c
+++ b/drivers/block/as-iosched.c
@@ -1973,8 +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,
+        }
 };
 
 /*