path: root/block/as-iosched.c
diff options
authorDavid Howells <dhowells@redhat.com>2006-11-22 14:55:48 +0000
committerDavid Howells <dhowells@redhat.com>2006-11-22 14:55:48 +0000
commit65f27f38446e1976cc98fd3004b110fedcddd189 (patch)
tree68f8be93feae31dfa018c22db392a05546b63ee1 /block/as-iosched.c
parent365970a1ea76d81cb1ad2f652acb605f06dae256 (diff)
WorkStruct: Pass the work_struct pointer instead of context data
Pass the work_struct pointer to the work function rather than context data. The work function can use container_of() to work out the data. For the cases where the container of the work_struct may go away the moment the pending bit is cleared, it is made possible to defer the release of the structure by deferring the clearing of the pending bit. To make this work, an extra flag is introduced into the management side of the work_struct. This governs auto-release of the structure upon execution. Ordinarily, the work queue executor would release the work_struct for further scheduling or deallocation by clearing the pending bit prior to jumping to the work function. This means that, unless the driver makes some guarantee itself that the work_struct won't go away, the work function may not access anything else in the work_struct or its container lest they be deallocated.. This is a problem if the auxiliary data is taken away (as done by the last patch). However, if the pending bit is *not* cleared before jumping to the work function, then the work function *may* access the work_struct and its container with no problems. But then the work function must itself release the work_struct by calling work_release(). In most cases, automatic release is fine, so this is the default. Special initiators exist for the non-auto-release case (ending in _NAR). Signed-Off-By: David Howells <dhowells@redhat.com>
Diffstat (limited to 'block/as-iosched.c')
1 files changed, 4 insertions, 3 deletions
diff --git a/block/as-iosched.c b/block/as-iosched.c
index 50b95e4c142..f371c935999 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -1274,9 +1274,10 @@ static void as_merged_requests(request_queue_t *q, struct request *req,
* FIXME! dispatch queue is not a queue at all!
-static void as_work_handler(void *data)
+static void as_work_handler(struct work_struct *work)
- struct request_queue *q = data;
+ struct as_data *ad = container_of(work, struct as_data, antic_work);
+ struct request_queue *q = ad->q;
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
@@ -1332,7 +1333,7 @@ static void *as_init_queue(request_queue_t *q, elevator_t *e)
ad->antic_timer.function = as_antic_timeout;
ad->antic_timer.data = (unsigned long)q;
- INIT_WORK(&ad->antic_work, as_work_handler, q);
+ INIT_WORK(&ad->antic_work, as_work_handler);