nfsd: make nfsd4_run_cb a bool return function

queue_work can return false and not queue anything, if the work is
already queued. If that happens in the case of a CB_RECALL, we'll have
taken an extra reference to the stid that will never be put. Ensure we
throw a warning in that case.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 4ce3282..f0e69ed 100644 (file)
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -1371,11 +1371,21 @@ void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
        cb->cb_holds_slot = false;
 }
 
-void nfsd4_run_cb(struct nfsd4_callback *cb)
+/**
+ * nfsd4_run_cb - queue up a callback job to run
+ * @cb: callback to queue
+ *
+ * Kick off a callback to do its thing. Returns false if it was already
+ * on a queue, true otherwise.
+ */
+bool nfsd4_run_cb(struct nfsd4_callback *cb)
 {
        struct nfs4_client *clp = cb->cb_clp;
+       bool queued;
 
        nfsd41_cb_inflight_begin(clp);
-       if (!nfsd4_queue_cb(cb))
+       queued = nfsd4_queue_cb(cb);
+       if (!queued)
                nfsd41_cb_inflight_end(clp);
+       return queued;
 }

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index e116f50..c78c322 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4859,14 +4859,13 @@ static void nfsd_break_one_deleg(struct nfs4_delegation *dp)
         * we know it's safe to take a reference.
         */
        refcount_inc(&dp->dl_stid.sc_count);
-       nfsd4_run_cb(&dp->dl_recall);
+       WARN_ON_ONCE(!nfsd4_run_cb(&dp->dl_recall));
 }
 
 /* Called from break_lease() with flc_lock held. */
 static bool
 nfsd_break_deleg_cb(struct file_lock *fl)
 {
-       bool ret = false;
        struct nfs4_delegation *dp = (struct nfs4_delegation *)fl->fl_owner;
        struct nfs4_file *fp = dp->dl_stid.sc_file;
        struct nfs4_client *clp = dp->dl_stid.sc_client;
@@ -4892,7 +4891,7 @@ nfsd_break_deleg_cb(struct file_lock *fl)
        fp->fi_had_conflict = true;
        nfsd_break_one_deleg(dp);
        spin_unlock(&fp->fi_lock);
-       return ret;
+       return false;
 }
 
 /**

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index b347708..e2daef3 100644 (file)
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -692,7 +692,7 @@ extern void nfsd4_probe_callback_sync(struct nfs4_client *clp);
 extern void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *);
 extern void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
                const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op);
-extern void nfsd4_run_cb(struct nfsd4_callback *cb);
+extern bool nfsd4_run_cb(struct nfsd4_callback *cb);
 extern int nfsd4_create_callback_queue(void);
 extern void nfsd4_destroy_callback_queue(void);
 extern void nfsd4_shutdown_callback(struct nfs4_client *);