[PATCH 7/9] afs: don't use PREPARE_WORK

From: Tejun Heo
Date: Thu Feb 20 2014 - 15:46:48 EST


PREPARE_[DELAYED_]WORK() are being phased out. They have few users
and a nasty surprise in terms of reentrancy guarantee as workqueue
considers work items to be different if they don't have the same work
function.

afs_call->async_work is multiplexed with multiple work functions.
Introduce afs_async_workfn() which invokes afs_call->async_workfn and
always use it as the work function and update the users to set the
->async_workfn field instead of overriding the work function using
PREPARE_WORK().

It would probably be best to route this with other related updates
through the workqueue tree.

Compile tested.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: linux-afs@xxxxxxxxxxxxxxxxxxx
---
fs/afs/internal.h | 1 +
fs/afs/rxrpc.c | 12 ++++++++++--
2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 6621f80..be75b50 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -75,6 +75,7 @@ struct afs_call {
const struct afs_call_type *type; /* type of call */
const struct afs_wait_mode *wait_mode; /* completion wait mode */
wait_queue_head_t waitq; /* processes awaiting completion */
+ work_func_t async_workfn;
struct work_struct async_work; /* asynchronous work processor */
struct work_struct work; /* actual work processor */
struct sk_buff_head rx_queue; /* received packets */
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 8ad8c2a..ef943df 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -644,7 +644,7 @@ static void afs_process_async_call(struct work_struct *work)

/* we can't just delete the call because the work item may be
* queued */
- PREPARE_WORK(&call->async_work, afs_delete_async_call);
+ call->async_workfn = afs_delete_async_call;
queue_work(afs_async_calls, &call->async_work);
}

@@ -663,6 +663,13 @@ void afs_transfer_reply(struct afs_call *call, struct sk_buff *skb)
call->reply_size += len;
}

+static void afs_async_workfn(struct work_struct *work)
+{
+ struct afs_call *call = container_of(work, struct afs_call, async_work);
+
+ call->async_workfn(work);
+}
+
/*
* accept the backlog of incoming calls
*/
@@ -685,7 +692,8 @@ static void afs_collect_incoming_call(struct work_struct *work)
return;
}

- INIT_WORK(&call->async_work, afs_process_async_call);
+ call->async_workfn = afs_process_async_call;
+ INIT_WORK(&call->async_work, afs_async_workfn);
call->wait_mode = &afs_async_incoming_call;
call->type = &afs_RXCMxxxx;
init_waitqueue_head(&call->waitq);
--
1.8.5.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/