netfs: Set the request work function upon allocation

Set the work function in the netfs_io_request work_struct when we allocate
the request rather than doing this later.  This reduces the number of
places we need to set it in future code.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20240814203850.2240469-11-dhowells@redhat.com/ # v2
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs/netfs/internal.h

@@ -29,6 +29,7 @@ int netfs_prefetch_for_write(struct file *file, struct folio *folio,
 /*
  * io.c
  */
+void netfs_rreq_work(struct work_struct *work);
 int netfs_begin_read(struct netfs_io_request *rreq, bool sync);
 
 /*

fs/netfs/io.c

@@ -426,7 +426,7 @@ static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
 	netfs_rreq_completed(rreq, was_async);
 }
 
-static void netfs_rreq_work(struct work_struct *work)
+void netfs_rreq_work(struct work_struct *work)
 {
 	struct netfs_io_request *rreq =
 		container_of(work, struct netfs_io_request, work);
@@ -739,8 +739,6 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
 	// TODO: Use bounce buffer if requested
 	rreq->io_iter = rreq->iter;
 
-	INIT_WORK(&rreq->work, netfs_rreq_work);
-
 	/* Chop the read into slices according to what the cache and the netfs
 	 * want and submit each one.
 	 */

fs/netfs/objects.c

@@ -48,9 +48,16 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 	INIT_LIST_HEAD(&rreq->io_streams[0].subrequests);
 	INIT_LIST_HEAD(&rreq->io_streams[1].subrequests);
 	INIT_LIST_HEAD(&rreq->subrequests);
-	INIT_WORK(&rreq->work, NULL);
 	refcount_set(&rreq->ref, 1);
 
+	if (origin == NETFS_READAHEAD ||
+	    origin == NETFS_READPAGE ||
+	    origin == NETFS_READ_FOR_WRITE ||
+	    origin == NETFS_DIO_READ)
+		INIT_WORK(&rreq->work, netfs_rreq_work);
+	else
+		INIT_WORK(&rreq->work, netfs_write_collection_worker);
+
 	__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
 	if (file && file->f_flags & O_NONBLOCK)
 		__set_bit(NETFS_RREQ_NONBLOCK, &rreq->flags);

fs/netfs/write_issue.c

@@ -109,7 +109,6 @@ struct netfs_io_request *netfs_create_write_req(struct address_space *mapping,
 
 	wreq->contiguity = wreq->start;
 	wreq->cleaned_to = wreq->start;
-	INIT_WORK(&wreq->work, netfs_write_collection_worker);
 
 	wreq->io_streams[0].stream_nr		= 0;
 	wreq->io_streams[0].source		= NETFS_UPLOAD_TO_SERVER;