path: root/block/ll_rw_blk.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/ll_rw_blk.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/ll_rw_blk.c')
1 files changed, 4 insertions, 4 deletions
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 9eaee664053..eb4cf6df737 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -34,7 +34,7 @@
#include <scsi/scsi_cmnd.h>
-static void blk_unplug_work(void *data);
+static void blk_unplug_work(struct work_struct *work);
static void blk_unplug_timeout(unsigned long data);
static void drive_stat_acct(struct request *rq, int nr_sectors, int new_io);
static void init_request_from_bio(struct request *req, struct bio *bio);
@@ -227,7 +227,7 @@ void blk_queue_make_request(request_queue_t * q, make_request_fn * mfn)
if (q->unplug_delay == 0)
q->unplug_delay = 1;
- INIT_WORK(&q->unplug_work, blk_unplug_work, q);
+ INIT_WORK(&q->unplug_work, blk_unplug_work);
q->unplug_timer.function = blk_unplug_timeout;
q->unplug_timer.data = (unsigned long)q;
@@ -1631,9 +1631,9 @@ static void blk_backing_dev_unplug(struct backing_dev_info *bdi,
-static void blk_unplug_work(void *data)
+static void blk_unplug_work(struct work_struct *work)
- request_queue_t *q = data;
+ request_queue_t *q = container_of(work, request_queue_t, unplug_work);
blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL,
q->rq.count[READ] + q->rq.count[WRITE]);