nfsd4: Move callback setup to callback queue
Instead of creating the new rpc client from a regular server thread,
set a flag, kick off a null call, and allow the null call to do the work
of setting up the client on the callback workqueue.
Use a spinlock to ensure the callback work gets a consistent view of the
callback parameters.
This allows, for example, changing the callback from contexts where
sleeping is not allowed. I hope it will also keep the locking simple as
we add more session and trunking features, by serializing most of the
callback-specific work.
This also closes a small race where the the new cb_ident could be used
with an old connection (or vice-versa).
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 2f464fb..d3f12dc 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -207,7 +207,6 @@
{
struct nfs4_delegation *dp;
struct nfs4_file *fp = stp->st_file;
- struct nfs4_cb_conn *conn = &stp->st_stateowner->so_client->cl_cb_conn;
dprintk("NFSD alloc_init_deleg\n");
/*
@@ -234,7 +233,6 @@
nfs4_file_get_access(fp, O_RDONLY);
dp->dl_flock = NULL;
dp->dl_type = type;
- dp->dl_ident = conn->cb_ident;
dp->dl_stateid.si_boot = boot_time;
dp->dl_stateid.si_stateownerid = current_delegid++;
dp->dl_stateid.si_fileid = 0;
@@ -875,7 +873,7 @@
sop = list_entry(clp->cl_openowners.next, struct nfs4_stateowner, so_perclient);
release_openowner(sop);
}
- nfsd4_set_callback_client(clp, NULL);
+ nfsd4_shutdown_callback(clp);
if (clp->cl_cb_conn.cb_xprt)
svc_xprt_put(clp->cl_cb_conn.cb_xprt);
list_del(&clp->cl_idhash);
@@ -978,6 +976,7 @@
INIT_LIST_HEAD(&clp->cl_delegations);
INIT_LIST_HEAD(&clp->cl_sessions);
INIT_LIST_HEAD(&clp->cl_lru);
+ spin_lock_init(&clp->cl_lock);
INIT_WORK(&clp->cl_cb_null.cb_work, nfsd4_do_callback_rpc);
clp->cl_time = get_seconds();
clear_bit(0, &clp->cl_cb_slot_busy);
@@ -1547,7 +1546,7 @@
nfs4_lock_state();
/* wait for callbacks */
- nfsd4_set_callback_client(ses->se_client, NULL);
+ nfsd4_shutdown_callback(ses->se_client);
nfs4_unlock_state();
nfsd4_put_session(ses);
status = nfs_ok;