NFS: Add an iocounter wait function for async RPC tasks

By sleeping on a new NFS Unlock-On-Close waitqueue, rpc tasks may wait for
a lock context's iocounter to reach zero.  The rpc waitqueue is only woken
when the open_context has the NFS_CONTEXT_UNLOCK flag set in order to
mitigate spurious wake-ups for any iocounter reaching zero.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Benjamin Coddington
2017-04-11 12:50:10 -04:00
committed by Trond Myklebust
parent 50f2112cf7
commit 7d6ddf88c4
5 changed files with 37 additions and 1 deletions

View File

@@ -141,6 +141,7 @@ extern int nfs_page_group_lock(struct nfs_page *, bool);
extern void nfs_page_group_lock_wait(struct nfs_page *);
extern void nfs_page_group_unlock(struct nfs_page *);
extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);
extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *);
/*
* Lock the page of an asynchronous request