6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Howells dhowells@redhat.com
[ Upstream commit 9750be93b2be12b6d92323b97d7c055099d279e6 ]
If we manage to begin an async call, but fail to transmit any data on it due to a signal, we then abort it which causes a race between the notification of call completion from rxrpc and our attempt to cancel the notification. The notification will be necessary, however, for async FetchData to terminate the netfs subrequest.
However, since we get a notification from rxrpc upon completion of a call (aborted or otherwise), we can just leave it to that.
This leads to calls not getting cleaned up, but appearing in /proc/net/rxrpc/calls as being aborted with code 6.
Fix this by making the "error_do_abort:" case of afs_make_call() abort the call and then abandon it to the notification handler.
Fixes: 34fa47612bfe ("afs: Fix race in async call refcounting") Reported-by: Marc Dionne marc.dionne@auristor.com Signed-off-by: David Howells dhowells@redhat.com Link: https://lore.kernel.org/r/20241216204124.3752367-25-dhowells@redhat.com cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/afs/internal.h | 9 +++++++++ fs/afs/rxrpc.c | 12 +++++++++--- include/trace/events/afs.h | 2 ++ 3 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 8dcc09cf0adbe..2f135d19545b1 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -1286,6 +1286,15 @@ extern void afs_send_simple_reply(struct afs_call *, const void *, size_t); extern int afs_extract_data(struct afs_call *, bool); extern int afs_protocol_error(struct afs_call *, enum afs_eproto_cause);
+static inline void afs_see_call(struct afs_call *call, enum afs_call_trace why) +{ + int r = refcount_read(&call->ref); + + trace_afs_call(call->debug_id, why, r, + atomic_read(&call->net->nr_outstanding_calls), + __builtin_return_address(0)); +} + static inline void afs_make_op_call(struct afs_operation *op, struct afs_call *call, gfp_t gfp) { diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c index d642d06a453be..43154c70366ae 100644 --- a/fs/afs/rxrpc.c +++ b/fs/afs/rxrpc.c @@ -396,11 +396,16 @@ void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp) return;
error_do_abort: - if (ret != -ECONNABORTED) { + if (ret != -ECONNABORTED) rxrpc_kernel_abort_call(call->net->socket, rxcall, RX_USER_ABORT, ret, afs_abort_send_data_error); - } else { + if (call->async) { + afs_see_call(call, afs_call_trace_async_abort); + return; + } + + if (ret == -ECONNABORTED) { len = 0; iov_iter_kvec(&msg.msg_iter, ITER_DEST, NULL, 0, 0); rxrpc_kernel_recv_data(call->net->socket, rxcall, @@ -412,6 +417,8 @@ void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp) call->error = ret; trace_afs_call_done(call); error_kill_call: + if (call->async) + afs_see_call(call, afs_call_trace_async_kill); if (call->type->done) call->type->done(call);
@@ -566,7 +573,6 @@ static void afs_deliver_to_call(struct afs_call *call) abort_code = 0; call_complete: afs_set_call_complete(call, ret, remote_abort); - state = AFS_CALL_COMPLETE; goto done; }
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h index d1ee4272d1cb8..ceb0146ffc7cd 100644 --- a/include/trace/events/afs.h +++ b/include/trace/events/afs.h @@ -118,6 +118,8 @@ enum yfs_cm_operation { */ #define afs_call_traces \ EM(afs_call_trace_alloc, "ALLOC") \ + EM(afs_call_trace_async_abort, "ASYAB") \ + EM(afs_call_trace_async_kill, "ASYKL") \ EM(afs_call_trace_free, "FREE ") \ EM(afs_call_trace_get, "GET ") \ EM(afs_call_trace_put, "PUT ") \