From 452181936931f0f08923aba5e04e1e9ef58c389f Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 20 Jun 2019 18:12:17 +0100 Subject: afs: Trace afs_server usage Add a tracepoint (afs_server) to track the afs_server object usage count. Signed-off-by: David Howells --- fs/afs/server.c | 39 ++++++++++++++++++++++++++++++++------- 1 file changed, 32 insertions(+), 7 deletions(-) (limited to 'fs/afs/server.c') diff --git a/fs/afs/server.c b/fs/afs/server.c index 52c170b59cfd..b69571bb9d37 100644 --- 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; @@ -328,10 +331,23 @@ void afs_servers_timer(struct timer_list *timer) afs_dec_servers_outstanding(net); } +/* + * 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)) { -- cgit v1.2.3