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authorTejun Heo <tj@kernel.org>2012-03-05 13:14:57 -0800
committerJens Axboe <axboe@kernel.dk>2012-03-06 21:27:21 +0100
commitb2fab5acd28ead6f0dd6c3996ba23f0ef1772f15 (patch)
treeb0b96984e1a4d9c856edc9ddfc36e427951c5a86
parent5a5bafdc396b1da7570f84fb96a0f8a288970c5e (diff)
elevator: make elevator_init_fn() return 0/-errno
elevator_ops->elevator_init_fn() has a weird return value. It returns a void * which the caller should assign to q->elevator->elevator_data and %NULL return denotes init failure. Update such that it returns integer 0/-errno and sets elevator_data directly as necessary. This makes the interface more conventional and eases further cleanup. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/cfq-iosched.c9
-rw-r--r--block/deadline-iosched.c8
-rw-r--r--block/elevator.c12
-rw-r--r--block/noop-iosched.c8
-rw-r--r--include/linux/elevator.h2
5 files changed, 18 insertions, 21 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 388fe01de18e..72680a6715fc 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3656,7 +3656,7 @@ static void cfq_exit_queue(struct elevator_queue *e)
kfree(cfqd);
}
-static void *cfq_init_queue(struct request_queue *q)
+static int cfq_init_queue(struct request_queue *q)
{
struct cfq_data *cfqd;
int i, j;
@@ -3665,7 +3665,7 @@ static void *cfq_init_queue(struct request_queue *q)
cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node);
if (!cfqd)
- return NULL;
+ return -ENOMEM;
/* Init root service tree */
cfqd->grp_service_tree = CFQ_RB_ROOT;
@@ -3692,7 +3692,7 @@ static void *cfq_init_queue(struct request_queue *q)
if (blkio_alloc_blkg_stats(&cfqg->blkg)) {
kfree(cfqg);
kfree(cfqd);
- return NULL;
+ return -ENOMEM;
}
rcu_read_lock();
@@ -3723,6 +3723,7 @@ static void *cfq_init_queue(struct request_queue *q)
cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group);
cfqd->queue = q;
+ q->elevator->elevator_data = cfqd;
init_timer(&cfqd->idle_slice_timer);
cfqd->idle_slice_timer.function = cfq_idle_slice_timer;
@@ -3747,7 +3748,7 @@ static void *cfq_init_queue(struct request_queue *q)
* second, in order to have larger depth for async operations.
*/
cfqd->last_delayed_sync = jiffies - HZ;
- return cfqd;
+ return 0;
}
/*
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index 7bf12d793fcd..599b12e5380f 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -337,13 +337,13 @@ static void deadline_exit_queue(struct elevator_queue *e)
/*
* initialize elevator private data (deadline_data).
*/
-static void *deadline_init_queue(struct request_queue *q)
+static int deadline_init_queue(struct request_queue *q)
{
struct deadline_data *dd;
dd = kmalloc_node(sizeof(*dd), GFP_KERNEL | __GFP_ZERO, q->node);
if (!dd)
- return NULL;
+ return -ENOMEM;
INIT_LIST_HEAD(&dd->fifo_list[READ]);
INIT_LIST_HEAD(&dd->fifo_list[WRITE]);
@@ -354,7 +354,9 @@ static void *deadline_init_queue(struct request_queue *q)
dd->writes_starved = writes_starved;
dd->front_merges = 1;
dd->fifo_batch = fifo_batch;
- return dd;
+
+ q->elevator->elevator_data = dd;
+ return 0;
}
/*
diff --git a/block/elevator.c b/block/elevator.c
index f8c08e1bff2b..f81c061dad15 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -121,14 +121,6 @@ static struct elevator_type *elevator_get(const char *name)
return e;
}
-static int elevator_init_queue(struct request_queue *q)
-{
- q->elevator->elevator_data = q->elevator->type->ops.elevator_init_fn(q);
- if (q->elevator->elevator_data)
- return 0;
- return -ENOMEM;
-}
-
static char chosen_elevator[ELV_NAME_MAX];
static int __init elevator_setup(char *str)
@@ -224,7 +216,7 @@ int elevator_init(struct request_queue *q, char *name)
if (!q->elevator)
return -ENOMEM;
- err = elevator_init_queue(q);
+ err = e->ops.elevator_init_fn(q);
if (err) {
kobject_put(&q->elevator->kobj);
return err;
@@ -927,7 +919,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
if (!q->elevator)
goto fail_init;
- err = elevator_init_queue(q);
+ err = new_e->ops.elevator_init_fn(q);
if (err) {
kobject_put(&q->elevator->kobj);
goto fail_init;
diff --git a/block/noop-iosched.c b/block/noop-iosched.c
index 413a0b1d788c..5d1bf70e33d5 100644
--- a/block/noop-iosched.c
+++ b/block/noop-iosched.c
@@ -59,15 +59,17 @@ noop_latter_request(struct request_queue *q, struct request *rq)
return list_entry(rq->queuelist.next, struct request, queuelist);
}
-static void *noop_init_queue(struct request_queue *q)
+static int noop_init_queue(struct request_queue *q)
{
struct noop_data *nd;
nd = kmalloc_node(sizeof(*nd), GFP_KERNEL, q->node);
if (!nd)
- return NULL;
+ return -ENOMEM;
+
INIT_LIST_HEAD(&nd->queue);
- return nd;
+ q->elevator->elevator_data = nd;
+ return 0;
}
static void noop_exit_queue(struct elevator_queue *e)
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index 7d4e0356f329..97fb2557a18c 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -33,7 +33,7 @@ typedef void (elevator_put_req_fn) (struct request *);
typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *);
typedef void (elevator_deactivate_req_fn) (struct request_queue *, struct request *);
-typedef void *(elevator_init_fn) (struct request_queue *);
+typedef int (elevator_init_fn) (struct request_queue *);
typedef void (elevator_exit_fn) (struct elevator_queue *);
struct elevator_ops