kernel/include/net/af_rxrpc.h, branch linux-5.1.y

rxrpc: Make rxrpc_kernel_check_life() indicate if call completed

2019-04-12T23:57:23Z

Make rxrpc_kernel_check_life() pass back the life counter through the argument list and return true if the call has not yet completed. Suggested-by: Marc Dionne Signed-off-by: David Howells Signed-off-by: David S. Miller

Revert "rxrpc: Allow failed client calls to be retried"

2019-01-16T05:33:36Z

The changes introduced to allow rxrpc calls to be retried creates an issue when it comes to refcounting afs_call structs. The problem is that when rxrpc_send_data() queues the last packet for an asynchronous call, the following sequence can occur: (1) The notify_end_tx callback is invoked which causes the state in the afs_call to be changed from AFS_CALL_CL_REQUESTING or AFS_CALL_SV_REPLYING. (2) afs_deliver_to_call() can then process event notifications from rxrpc on the async_work queue. (3) Delivery of events, such as an abort from the server, can cause the afs_call state to be changed to AFS_CALL_COMPLETE on async_work. (4) For an asynchronous call, afs_process_async_call() notes that the call is complete and tried to clean up all the refs on async_work. (5) rxrpc_send_data() might return the amount of data transferred (success) or an error - which could in turn reflect a local error or a received error. Synchronising the clean up after rxrpc_kernel_send_data() returns an error with the asynchronous cleanup is then tricky to get right. Mostly revert commit c038a58ccfd6704d4d7d60ed3d6a0fca13cf13a4. The two API functions the original commit added aren't currently used. This makes rxrpc_kernel_send_data() always return successfully if it queued the data it was given. Note that this doesn't affect synchronous calls since their Rx notification function merely pokes a wait queue and does not refcounting. The asynchronous call notification function *has* to do refcounting and pass a ref over the work item to avoid the need to sync the workqueue in call cleanup. Signed-off-by: David Howells Signed-off-by: David S. Miller

rxrpc: Fix life check

2018-11-15T19:35:40Z

The life-checking function, which is used by kAFS to make sure that a call is still live in the event of a pending signal, only samples the received packet serial number counter; it doesn't actually provoke a change in the counter, rather relying on the server to happen to give us a packet in the time window. Fix this by adding a function to force a ping to be transmitted. kAFS then keeps track of whether there's been a stall, and if so, uses the new function to ping the server, resetting the timeout to allow the reply to come back. If there's a stall, a ping and the call is *still* stalled in the same place after another period, then the call will be aborted. Fixes: bc5e3a546d55 ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals") Fixes: f4d15fb6f99a ("rxrpc: Provide functions for allowing cleaner handling of signals") Signed-off-by: David Howells Signed-off-by: David S. Miller

rxrpc: Allow the reply time to be obtained on a client call

2018-10-04T08:54:29Z

Allow the epoch value to be queried on a server connection. This is in the rxrpc header of every packet for use in routing and is derived from the client's state. It's also not supposed to change unless the client gets restarted. AFS can make use of this information to deduce whether a fileserver has been restarted because the fileserver makes client calls to the filesystem driver's cache manager to send notifications (ie. callback breaks) about conflicting changes from other clients. These convey the fileserver's own epoch value back to the filesystem. Signed-off-by: David Howells

rxrpc: Allow the reply time to be obtained on a client call

2018-10-04T08:42:29Z

Allow the timestamp on the sk_buff holding the first DATA packet of a reply to be queried. This can then be used as a base for the expiry time calculation on the callback promise duration indicated by an operation result. Signed-off-by: David Howells

rxrpc: Push iov_iter up from rxrpc_kernel_recv_data() to caller

2018-08-03T19:46:20Z

Push iov_iter up from rxrpc_kernel_recv_data() to its caller to allow non-contiguous iovs to be passed down, thereby permitting file reading to be simplified in the AFS filesystem in a future patch. Signed-off-by: David Howells Signed-off-by: David S. Miller

rxrpc, afs: Use debug_ids rather than pointers in traces

2018-03-27T22:03:00Z

In rxrpc and afs, use the debug_ids that are monotonically allocated to various objects as they're allocated rather than pointers as kernel pointers are now hashed making them less useful. Further, the debug ids aren't reused anywhere nearly as quickly. In addition, allow kernel services that use rxrpc, such as afs, to take numbers from the rxrpc counter, assign them to their own call struct and pass them in to rxrpc for both client and service calls so that the trace lines for each will have the same ID tag. Signed-off-by: David Howells

rxrpc: Provide functions for allowing cleaner handling of signals

2017-10-18T10:42:48Z

Provide a couple of functions to allow cleaner handling of signals in a kernel service. They are: (1) rxrpc_kernel_get_rtt() This allows the kernel service to find out the RTT time for a call, so as to better judge how large a timeout to employ. Note, though, that whilst this returns a value in nanoseconds, the timeouts can only actually be in jiffies. (2) rxrpc_kernel_check_life() This returns a number that is updated when ACKs are received from the peer (notably including PING RESPONSE ACKs which we can elicit by sending PING ACKs to see if the call still exists on the server). The caller should compare the numbers of two calls to see if the call is still alive. These can be used to provide an extending timeout rather than returning immediately in the case that a signal occurs that would otherwise abort an RPC operation. The timeout would be extended if the server is still responsive and the call is still apparently alive on the server. For most operations this isn't that necessary - but for FS.StoreData it is: OpenAFS writes the data to storage as it comes in without making a backup, so if we immediately abort it when partially complete on a CTRL+C, say, we have no idea of the state of the file after the abort. Signed-off-by: David Howells

rxrpc: Support service upgrade from a kernel service

2017-10-18T10:37:20Z

Provide support for a kernel service to make use of the service upgrade facility. This involves: (1) Pass an upgrade request flag to rxrpc_kernel_begin_call(). (2) Make rxrpc_kernel_recv_data() return the call's current service ID so that the caller can detect service upgrade and see what the service was upgraded to. Signed-off-by: David Howells

rxrpc: Allow failed client calls to be retried

2017-08-29T09:55:20Z

Allow a client call that failed on network error to be retried, provided that the Tx queue still holds DATA packet 1. This allows an operation to be submitted to another server or another address for the same server without having to repackage and re-encrypt the data so far processed. Two new functions are provided: (1) rxrpc_kernel_check_call() - This is used to find out the completion state of a call to guess whether it can be retried and whether it should be retried. (2) rxrpc_kernel_retry_call() - Disconnect the call from its current connection, reset the state and submit it as a new client call to a new address. The new address need not match the previous address. A call may be retried even if all the data hasn't been loaded into it yet; a partially constructed will be retained at the same point it was at when an error condition was detected. msg_data_left() can be used to find out how much data was packaged before the error occurred. Signed-off-by: David Howells