afs: Trace afs_server usage

Add a tracepoint (afs_server) to track the afs_server object usage count.

Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index d66cd03..6cdd704 100644 (file)
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -48,7 +48,7 @@ static struct afs_cb_interest *afs_create_interest(struct afs_server *server,
        refcount_set(&new->usage, 1);
        new->sb = vnode->vfs_inode.i_sb;
        new->vid = vnode->volume->vid;
-       new->server = afs_get_server(server);
+       new->server = afs_get_server(server, afs_server_trace_get_new_cbi);
        INIT_HLIST_NODE(&new->cb_vlink);
 
        write_lock(&server->cb_break_lock);
@@ -195,7 +195,7 @@ void afs_put_cb_interest(struct afs_net *net, struct afs_cb_interest *cbi)
                        write_unlock(&cbi->server->cb_break_lock);
                        if (vi)
                                kfree_rcu(vi, rcu);
-                       afs_put_server(net, cbi->server);
+                       afs_put_server(net, cbi->server, afs_server_trace_put_cbi);
                }
                kfree_rcu(cbi, rcu);
        }

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 01437cf..e114d6b 100644 (file)
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -260,8 +260,11 @@ static void SRXAFSCB_CallBack(struct work_struct *work)
         * server holds up change visibility till it receives our reply so as
         * to maintain cache coherency.
         */
-       if (call->server)
+       if (call->server) {
+               trace_afs_server(call->server, atomic_read(&call->server->usage),
+                                afs_server_trace_callback);
                afs_break_callbacks(call->server, call->count, call->request);
+       }
 
        afs_send_empty_reply(call);
        afs_put_call(call);

diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 4829840..8274e2e 100644 (file)
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -1915,7 +1915,7 @@ struct afs_call *afs_fs_get_capabilities(struct afs_net *net,
                return ERR_PTR(-ENOMEM);
 
        call->key = key;
-       call->server = afs_get_server(server);
+       call->server = afs_get_server(server, afs_server_trace_get_caps);
        call->server_index = server_index;
        call->upgrade = true;
        call->async = true;

diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 4d9b3e9..b03f321 100644 (file)
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -518,6 +518,7 @@ struct afs_server {
        atomic_t                usage;
        u32                     addr_version;   /* Address list version */
        u32                     cm_epoch;       /* Server RxRPC epoch */
+       unsigned int            debug_id;       /* Debugging ID for traces */
 
        /* file service access */
        rwlock_t                fs_lock;        /* access lock */
@@ -1244,17 +1245,12 @@ extern void __exit afs_clean_up_permit_cache(void);
  */
 extern spinlock_t afs_server_peer_lock;
 
-static inline struct afs_server *afs_get_server(struct afs_server *server)
-{
-       atomic_inc(&server->usage);
-       return server;
-}
-
 extern struct afs_server *afs_find_server(struct afs_net *,
                                          const struct sockaddr_rxrpc *);
 extern struct afs_server *afs_find_server_by_uuid(struct afs_net *, const uuid_t *);
 extern struct afs_server *afs_lookup_server(struct afs_cell *, struct key *, const uuid_t *);
-extern void afs_put_server(struct afs_net *, struct afs_server *);
+extern struct afs_server *afs_get_server(struct afs_server *, enum afs_server_trace);
+extern void afs_put_server(struct afs_net *, struct afs_server *, enum afs_server_trace);
 extern void afs_manage_servers(struct work_struct *);
 extern void afs_servers_timer(struct timer_list *);
 extern void __net_exit afs_purge_servers(struct afs_net *);

diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 4fa5ce9..32d1721 100644 (file)
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -188,7 +188,7 @@ void afs_put_call(struct afs_call *call)
                if (call->type->destructor)
                        call->type->destructor(call);
 
-               afs_put_server(call->net, call->server);
+               afs_put_server(call->net, call->server, afs_server_trace_put_call);
                afs_put_cb_interest(call->net, call->cbi);
                afs_put_addrlist(call->alist);
                kfree(call->request);

diff --git a/fs/afs/server.c b/fs/afs/server.c
index 52c170b..b69571b 100644 (file)
--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -17,6 +17,7 @@
 
 static unsigned afs_server_gc_delay = 10;      /* Server record timeout in seconds */
 static unsigned afs_server_update_delay = 30;  /* Time till VLDB recheck in secs */
+static atomic_t afs_server_debug_id;
 
 static void afs_inc_servers_outstanding(struct afs_net *net)
 {
@@ -51,7 +52,7 @@ struct afs_server *afs_find_server(struct afs_net *net,
 
        do {
                if (server)
-                       afs_put_server(net, server);
+                       afs_put_server(net, server, afs_server_trace_put_find_rsq);
                server = NULL;
                read_seqbegin_or_lock(&net->fs_addr_lock, &seq);
 
@@ -116,7 +117,7 @@ struct afs_server *afs_find_server_by_uuid(struct afs_net *net, const uuid_t *uu
                 * changes.
                 */
                if (server)
-                       afs_put_server(net, server);
+                       afs_put_server(net, server, afs_server_trace_put_uuid_rsq);
                server = NULL;
 
                read_seqbegin_or_lock(&net->fs_lock, &seq);
@@ -131,7 +132,7 @@ struct afs_server *afs_find_server_by_uuid(struct afs_net *net, const uuid_t *uu
                        } else if (diff > 0) {
                                p = p->rb_right;
                        } else {
-                               afs_get_server(server);
+                               afs_get_server(server, afs_server_trace_get_by_uuid);
                                break;
                        }
 
@@ -202,7 +203,7 @@ static struct afs_server *afs_install_server(struct afs_net *net,
        ret = 0;
 
 exists:
-       afs_get_server(server);
+       afs_get_server(server, afs_server_trace_get_install);
        write_sequnlock(&net->fs_lock);
        return server;
 }
@@ -223,6 +224,7 @@ static struct afs_server *afs_alloc_server(struct afs_net *net,
                goto enomem;
 
        atomic_set(&server->usage, 1);
+       server->debug_id = atomic_inc_return(&afs_server_debug_id);
        RCU_INIT_POINTER(server->addresses, alist);
        server->addr_version = alist->version;
        server->uuid = *uuid;
@@ -234,6 +236,7 @@ static struct afs_server *afs_alloc_server(struct afs_net *net,
        spin_lock_init(&server->probe_lock);
 
        afs_inc_servers_outstanding(net);
+       trace_afs_server(server, 1, afs_server_trace_alloc);
        _leave(" = %p", server);
        return server;
 
@@ -329,9 +332,22 @@ void afs_servers_timer(struct timer_list *timer)
 }
 
 /*
+ * Get a reference on a server object.
+ */
+struct afs_server *afs_get_server(struct afs_server *server,
+                                 enum afs_server_trace reason)
+{
+       unsigned int u = atomic_inc_return(&server->usage);
+
+       trace_afs_server(server, u, reason);
+       return server;
+}
+
+/*
  * Release a reference on a server record.
  */
-void afs_put_server(struct afs_net *net, struct afs_server *server)
+void afs_put_server(struct afs_net *net, struct afs_server *server,
+                   enum afs_server_trace reason)
 {
        unsigned int usage;
 
@@ -342,7 +358,7 @@ void afs_put_server(struct afs_net *net, struct afs_server *server)
 
        usage = atomic_dec_return(&server->usage);
 
-       _enter("{%u}", usage);
+       trace_afs_server(server, usage, reason);
 
        if (likely(usage > 0))
                return;
@@ -354,6 +370,8 @@ static void afs_server_rcu(struct rcu_head *rcu)
 {
        struct afs_server *server = container_of(rcu, struct afs_server, rcu);
 
+       trace_afs_server(server, atomic_read(&server->usage),
+                        afs_server_trace_free);
        afs_put_addrlist(rcu_access_pointer(server->addresses));
        kfree(server);
 }
@@ -369,7 +387,9 @@ static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
                .index  = alist->preferred,
                .error  = 0,
        };
-       _enter("%p", server);
+
+       trace_afs_server(server, atomic_read(&server->usage),
+                        afs_server_trace_give_up_cb);
 
        if (test_bit(AFS_SERVER_FL_MAY_HAVE_CB, &server->flags))
                afs_fs_give_up_all_callbacks(net, server, &ac, NULL);
@@ -377,6 +397,8 @@ static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
        wait_var_event(&server->probe_outstanding,
                       atomic_read(&server->probe_outstanding) == 0);
 
+       trace_afs_server(server, atomic_read(&server->usage),
+                        afs_server_trace_destroy);
        call_rcu(&server->rcu, afs_server_rcu);
        afs_dec_servers_outstanding(net);
 }
@@ -396,6 +418,7 @@ static void afs_gc_servers(struct afs_net *net, struct afs_server *gc_list)
                write_seqlock(&net->fs_lock);
                usage = 1;
                deleted = atomic_try_cmpxchg(&server->usage, &usage, 0);
+               trace_afs_server(server, usage, afs_server_trace_gc);
                if (deleted) {
                        rb_erase(&server->uuid_rb, &net->fs_servers);
                        hlist_del_rcu(&server->proc_link);
@@ -518,6 +541,8 @@ static noinline bool afs_update_server_record(struct afs_fs_cursor *fc, struct a
 
        _enter("");
 
+       trace_afs_server(server, atomic_read(&server->usage), afs_server_trace_update);
+
        alist = afs_vl_lookup_addrs(fc->vnode->volume->cell, fc->key,
                                    &server->uuid);
        if (IS_ERR(alist)) {

diff --git a/fs/afs/server_list.c b/fs/afs/server_list.c
index 155dc14..f5c7860 100644 (file)
--- a/fs/afs/server_list.c
+++ b/fs/afs/server_list.c
@@ -20,7 +20,8 @@ void afs_put_serverlist(struct afs_net *net, struct afs_server_list *slist)
        if (slist && refcount_dec_and_test(&slist->usage)) {
                for (i = 0; i < slist->nr_servers; i++) {
                        afs_put_cb_interest(net, slist->servers[i].cb_interest);
-                       afs_put_server(net, slist->servers[i].server);
+                       afs_put_server(net, slist->servers[i].server,
+                                      afs_server_trace_put_slist);
                }
                kfree(slist);
        }
@@ -71,7 +72,8 @@ struct afs_server_list *afs_alloc_server_list(struct afs_cell *cell,
                                break;
                if (j < slist->nr_servers) {
                        if (slist->servers[j].server == server) {
-                               afs_put_server(cell->net, server);
+                               afs_put_server(cell->net, server,
+                                              afs_server_trace_put_slist_isort);
                                continue;
                        }
 

diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index 34628e2..29815dc 100644 (file)
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -31,6 +31,26 @@ enum afs_call_trace {
        afs_call_trace_work,
 };
 
+enum afs_server_trace {
+       afs_server_trace_alloc,
+       afs_server_trace_callback,
+       afs_server_trace_destroy,
+       afs_server_trace_free,
+       afs_server_trace_gc,
+       afs_server_trace_get_by_uuid,
+       afs_server_trace_get_caps,
+       afs_server_trace_get_install,
+       afs_server_trace_get_new_cbi,
+       afs_server_trace_give_up_cb,
+       afs_server_trace_put_call,
+       afs_server_trace_put_cbi,
+       afs_server_trace_put_find_rsq,
+       afs_server_trace_put_slist,
+       afs_server_trace_put_slist_isort,
+       afs_server_trace_put_uuid_rsq,
+       afs_server_trace_update,
+};
+
 enum afs_fs_operation {
        afs_FS_FetchData                = 130,  /* AFS Fetch file data */
        afs_FS_FetchACL                 = 131,  /* AFS Fetch file ACL */
@@ -219,6 +239,25 @@ enum afs_cb_break_reason {
        EM(afs_call_trace_wake,                 "WAKE ") \
        E_(afs_call_trace_work,                 "WORK ")
 
+#define afs_server_traces \
+       EM(afs_server_trace_alloc,              "ALLOC    ") \
+       EM(afs_server_trace_callback,           "CALLBACK ") \
+       EM(afs_server_trace_destroy,            "DESTROY  ") \
+       EM(afs_server_trace_free,               "FREE     ") \
+       EM(afs_server_trace_gc,                 "GC       ") \
+       EM(afs_server_trace_get_by_uuid,        "GET uuid ") \
+       EM(afs_server_trace_get_caps,           "GET caps ") \
+       EM(afs_server_trace_get_install,        "GET inst ") \
+       EM(afs_server_trace_get_new_cbi,        "GET cbi  ") \
+       EM(afs_server_trace_give_up_cb,         "giveup-cb") \
+       EM(afs_server_trace_put_call,           "PUT call ") \
+       EM(afs_server_trace_put_cbi,            "PUT cbi  ") \
+       EM(afs_server_trace_put_find_rsq,       "PUT f-rsq") \
+       EM(afs_server_trace_put_slist,          "PUT slist") \
+       EM(afs_server_trace_put_slist_isort,    "PUT isort") \
+       EM(afs_server_trace_put_uuid_rsq,       "PUT u-req") \
+       E_(afs_server_trace_update,             "UPDATE")
+
 #define afs_fs_operations \
        EM(afs_FS_FetchData,                    "FS.FetchData") \
        EM(afs_FS_FetchStatus,                  "FS.FetchStatus") \
@@ -404,6 +443,7 @@ enum afs_cb_break_reason {
 #define E_(a, b) TRACE_DEFINE_ENUM(a);
 
 afs_call_traces;
+afs_server_traces;
 afs_fs_operations;
 afs_vl_operations;
 afs_edit_dir_ops;
@@ -1240,6 +1280,29 @@ TRACE_EVENT(afs_cb_miss,
                      __print_symbolic(__entry->reason, afs_cb_break_reasons))
            );
 
+TRACE_EVENT(afs_server,
+           TP_PROTO(struct afs_server *server, int usage, enum afs_server_trace reason),
+
+           TP_ARGS(server, usage, reason),
+
+           TP_STRUCT__entry(
+                   __field(unsigned int,               server          )
+                   __field(int,                        usage           )
+                   __field(int,                        reason          )
+                            ),
+
+           TP_fast_assign(
+                   __entry->server = server->debug_id;
+                   __entry->usage = usage;
+                   __entry->reason = reason;
+                          ),
+
+           TP_printk("s=%08x %s u=%d",
+                     __entry->server,
+                     __print_symbolic(__entry->reason, afs_server_traces),
+                     __entry->usage)
+           );
+
 #endif /* _TRACE_AFS_H */
 
 /* This part must be outside protection */