[PATCH 41/49] writeback: add wb_writeback_work->auto_free

Tejun Heo
2015-04-06T20:00:42Z

Currently, a wb_writeback_work is freed automatically on completion if
it doesn't have ->done set. Add wb_writeback_work->auto_free to make
the switch explicit. This will help cgroup writeback support where
waiting for completion and whether to free automatically don't
necessarily move together.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
---
fs/fs-writeback.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index d30bcd8..306229a 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -47,6 +47,7 @@ struct wb_writeback_work {
unsigned int range_cyclic:1;
unsigned int for_background:1;
unsigned int for_sync:1; /* sync(2) WB_SYNC_ALL writeback */
+ unsigned int auto_free:1; /* free on completion */
enum wb_reason reason; /* why was writeback initiated? */

struct list_head list; /* pending work list */
@@ -246,6 +247,7 @@ void wb_start_writeback(struct bdi_writeback *wb, long nr_pages,
work->nr_pages = nr_pages;
work->range_cyclic = range_cyclic;
work->reason = reason;
+ work->auto_free = 1;

wb_queue_work(wb, work);
}
@@ -1123,19 +1125,16 @@ static long wb_do_writeback(struct bdi_writeback *wb)

set_bit(WB_writeback_running, &wb->state);
while ((work = get_next_work_item(wb)) != NULL) {
+ struct completion *done = work->done;

trace_writeback_exec(wb->bdi, work);

wrote += wb_writeback(wb, work);

- /*
- * Notify the caller of completion if this is a synchronous
- * work item, otherwise just free it.
- */
- if (work->done)
- complete(work->done);
- else
+ if (work->auto_free)
kfree(work);
+ if (done)
+ complete(done);
}

/*
--
2.1.0