diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 8dcc09cf0adbeb5b20e6c06731b6e0680a4e594d..89b5464ca8ef43186569af8a1a4d8b29d24968ae 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -100,6 +100,7 @@ struct afs_call { wait_queue_head_t waitq; /* processes awaiting completion */ struct work_struct async_work; /* async I/O processor */ struct work_struct work; /* actual work processor */ + struct work_struct free_work; /* Deferred free processor */ struct rxrpc_call *rxcall; /* RxRPC call handle */ struct key *key; /* security for this call */ struct afs_net *net; /* The network namespace */ @@ -1275,6 +1276,7 @@ extern int __net_init afs_open_socket(struct afs_net *); extern void __net_exit afs_close_socket(struct afs_net *); extern void afs_charge_preallocation(struct work_struct *); extern void afs_put_call(struct afs_call *); +void afs_deferred_put_call(struct afs_call *call); extern void afs_make_call(struct afs_addr_cursor *, struct afs_call *, gfp_t); extern long afs_wait_for_call_to_complete(struct afs_call *, struct afs_addr_cursor *); extern struct afs_call *afs_alloc_flat_call(struct afs_net *, diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c index d642d06a453be75b40663ef2a1594dc696085e77..0a68460fe9dff450e713cac9fcaeb1067760d9f7 100644 --- a/fs/afs/rxrpc.c +++ b/fs/afs/rxrpc.c @@ -18,6 +18,7 @@ struct workqueue_struct *afs_async_calls; +static void afs_deferred_free_worker(struct work_struct *work); static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long); static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long); static void afs_process_async_call(struct work_struct *); @@ -149,6 +150,7 @@ static struct afs_call *afs_alloc_call(struct afs_net *net, call->debug_id = atomic_inc_return(&rxrpc_debug_id); refcount_set(&call->ref, 1); INIT_WORK(&call->async_work, afs_process_async_call); + INIT_WORK(&call->free_work, afs_deferred_free_worker); init_waitqueue_head(&call->waitq); spin_lock_init(&call->state_lock); call->iter = &call->def_iter; @@ -159,6 +161,35 @@ static struct afs_call *afs_alloc_call(struct afs_net *net, return call; } +static void afs_free_call(struct afs_call *call) +{ + struct afs_net *net = call->net; + int o; + + ASSERT(!work_pending(&call->async_work)); + + if (call->rxcall) { + rxrpc_kernel_shutdown_call(net->socket, call->rxcall); + rxrpc_kernel_put_call(net->socket, call->rxcall); + call->rxcall = NULL; + } + if (call->type->destructor) + call->type->destructor(call); + + afs_unuse_server_notime(call->net, call->server, afs_server_trace_put_call); + afs_put_addrlist(call->alist); + kfree(call->request); + + o = atomic_read(&net->nr_outstanding_calls); + trace_afs_call(call->debug_id, afs_call_trace_free, 0, o, + __builtin_return_address(0)); + kfree(call); + + o = atomic_dec_return(&net->nr_outstanding_calls); + if (o == 0) + wake_up_var(&net->nr_outstanding_calls); +} + /* * Dispose of a reference on a call. */ @@ -173,31 +204,34 @@ void afs_put_call(struct afs_call *call) o = atomic_read(&net->nr_outstanding_calls); trace_afs_call(debug_id, afs_call_trace_put, r - 1, o, __builtin_return_address(0)); + if (zero) + afs_free_call(call); +} - if (zero) { - ASSERT(!work_pending(&call->async_work)); - ASSERT(call->type->name != NULL); - - if (call->rxcall) { - rxrpc_kernel_shutdown_call(net->socket, call->rxcall); - rxrpc_kernel_put_call(net->socket, call->rxcall); - call->rxcall = NULL; - } - if (call->type->destructor) - call->type->destructor(call); +static void afs_deferred_free_worker(struct work_struct *work) +{ + struct afs_call *call = container_of(work, struct afs_call, free_work); - afs_unuse_server_notime(call->net, call->server, afs_server_trace_put_call); - afs_put_addrlist(call->alist); - kfree(call->request); + afs_free_call(call); +} - trace_afs_call(call->debug_id, afs_call_trace_free, 0, o, - __builtin_return_address(0)); - kfree(call); +/* + * Dispose of a reference on a call, deferring the cleanup to a workqueue + * to avoid lock recursion. + */ +void afs_deferred_put_call(struct afs_call *call) +{ + struct afs_net *net = call->net; + unsigned int debug_id = call->debug_id; + bool zero; + int r, o; - o = atomic_dec_return(&net->nr_outstanding_calls); - if (o == 0) - wake_up_var(&net->nr_outstanding_calls); - } + zero = __refcount_dec_and_test(&call->ref, &r); + o = atomic_read(&net->nr_outstanding_calls); + trace_afs_call(debug_id, afs_call_trace_put, r - 1, o, + __builtin_return_address(0)); + if (zero) + schedule_work(&call->free_work); } static struct afs_call *afs_get_call(struct afs_call *call, @@ -665,7 +699,8 @@ static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall, } /* - * wake up an asynchronous call + * Wake up an asynchronous call. The caller is holding the call notify + * spinlock around this, so we can't call afs_put_call(). */ static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall, unsigned long call_user_ID) @@ -682,7 +717,7 @@ static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall, __builtin_return_address(0)); if (!queue_work(afs_async_calls, &call->async_work)) - afs_put_call(call); + afs_deferred_put_call(call); } }