Looking at "ceph: add a dedicated private data for netfs rreq" you might find
the attached patch useful. It's in my list of netfs patches to push once I
get away from splice.
David
---
netfs: Allow the netfs to make the io (sub)request alloc larger
Allow the network filesystem to specify extra space to be allocated on the
end of the io (sub)request. This allows cifs, for example, to use this
space rather than allocating its own cifs_readdata struct.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
fs/netfs/objects.c | 7 +++++--
include/linux/netfs.h | 2 ++
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index e41f9fc9bdd2..2f1865ff7cce 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -22,7 +22,8 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
struct netfs_io_request *rreq;
int ret;
- rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL);
+ rreq = kzalloc(ctx->ops->io_request_size ?: sizeof(struct netfs_io_request),
+ GFP_KERNEL);
if (!rreq)
return ERR_PTR(-ENOMEM);
@@ -116,7 +117,9 @@ struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq
{
struct netfs_io_subrequest *subreq;
- subreq = kzalloc(sizeof(struct netfs_io_subrequest), GFP_KERNEL);
+ subreq = kzalloc(rreq->netfs_ops->io_subrequest_size ?:
+ sizeof(struct netfs_io_subrequest),
+ GFP_KERNEL);
if (subreq) {
INIT_LIST_HEAD(&subreq->rreq_link);
refcount_set(&subreq->ref, 2);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index b76a1548d311..442b88e39945 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -214,6 +214,8 @@ struct netfs_io_request {
* Operations the network filesystem can/must provide to the helpers.
*/
struct netfs_request_ops {
+ unsigned int io_request_size; /* Alloc size for netfs_io_request struct */
+ unsigned int io_subrequest_size; /* Alloc size for netfs_io_subrequest struct */
int (*init_request)(struct netfs_io_request *rreq, struct file *file);
void (*free_request)(struct netfs_io_request *rreq);
int (*begin_cache_operation)(struct netfs_io_request *rreq);
