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* rxrpc: Cache the congestion window settingDavid Howells2017-06-141-0/+6
| | | | | | | | | | | | | Cache the congestion window setting that was determined during a call's transmission phase when it finishes so that it can be used by the next call to the same peer, thereby shortcutting the slow-start algorithm. The value is stored in the rxrpc_peer struct and is accessed without locking. Each call takes the value that happens to be there when it starts and just overwrites the value when it finishes. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* rxrpc: Add service upgrade support for client connectionsDavid Howells2017-06-051-8/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make it possible for a client to use AuriStor's service upgrade facility. The client does this by adding an RXRPC_UPGRADE_SERVICE control message to the first sendmsg() of a call. This takes no parameters. When recvmsg() starts returning data from the call, the service ID field in the returned msg_name will reflect the result of the upgrade attempt. If the upgrade was ignored, srx_service will match what was set in the sendmsg(); if the upgrade happened the srx_service will be altered to indicate the service the server upgraded to. Note that: (1) The choice of upgrade service is up to the server (2) Further client calls to the same server that would share a connection are blocked if an upgrade probe is in progress. (3) This should only be used to probe the service. Clients should then use the returned service ID in all subsequent communications with that server (and not set the upgrade). Note that the kernel will not retain this information should the connection expire from its cache. (4) If a server that supports upgrading is replaced by one that doesn't, whilst a connection is live, and if the replacement is running, say, OpenAFS 1.6.4 or older or an older IBM AFS, then the replacement server will not respond to packets sent to the upgraded connection. At this point, calls will time out and the server must be reprobed. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Separate the connection's protocol service ID from the lookup IDDavid Howells2017-06-051-0/+4
| | | | | | | | | | | | | | | | | | Keep the rxrpc_connection struct's idea of the service ID that is exposed in the protocol separate from the service ID that's used as a lookup key. This allows the protocol service ID on a client connection to get upgraded without making the connection unfindable for other client calls that also would like to use the upgraded connection. The connection's actual service ID is then returned through recvmsg() by way of msg_name. Whilst we're at it, we get rid of the last_service_id field from each channel. The service ID is per-connection, not per-call and an entire connection is upgraded in one go. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Support network namespacingDavid Howells2017-05-251-78/+75
| | | | | | | | | | | | | | | | | | | | | | | | | Support network namespacing in AF_RXRPC with the following changes: (1) All the local endpoint, peer and call lists, locks, counters, etc. are moved into the per-namespace record. (2) All the connection tracking is moved into the per-namespace record with the exception of the client connection ID tree, which is kept global so that connection IDs are kept unique per-machine. (3) Each namespace gets its own epoch. This allows each network namespace to pretend to be a separate client machine. (4) The /proc/net/rxrpc_xxx files are now called /proc/net/rxrpc/xxx and the contents reflect the namespace. fs/afs/ should be okay with this patch as it explicitly requires the current net namespace to be init_net to permit a mount to proceed at the moment. It will, however, need updating so that cells, IP addresses and DNS records are per-namespace also. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* rxrpc: Trace client call connectionDavid Howells2017-04-061-0/+1
| | | | | | | | Add a tracepoint (rxrpc_connect_call) to log the combination of rxrpc_call pointer, afs_call pointer/user data and wire call parameters to make it easier to match the tracebuffer contents to captured network packets. Signed-off-by: David Howells <dhowells@redhat.com>
* sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar2017-03-021-0/+2
| | | | | | | | | | | | | <linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* rxrpc: Fix handling of enums-to-string translation in tracingDavid Howells2017-01-051-8/+0
| | | | | | | | | | | | | | | | | Fix the way enum values are translated into strings in AF_RXRPC tracepoints. The problem with just doing a lookup in a normal flat array of strings or chars is that external tracing infrastructure can't find it. Rather, TRACE_DEFINE_ENUM must be used. Also sort the enums and string tables to make it easier to keep them in order so that a future patch to __print_symbolic() can be optimised to try a direct lookup into the table first before iterating over it. A couple of _proto() macro calls are removed because they refered to tables that got moved to the tracing infrastructure. The relevant data can be found by way of tracing. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: abstract away knowledge of IDR internalsMatthew Wilcox2016-12-141-2/+2
| | | | | | | | | | | | | | | Add idr_get_cursor() / idr_set_cursor() APIs, and remove the reference to IDR_SIZE. Link: http://lkml.kernel.org/r/1480369871-5271-65-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: David Howells <dhowells@redhat.com> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rxrpc: When activating client conn channels, do state check inside lockDavid Howells2016-09-291-11/+25
| | | | | | | | | | | | | | | | | | | | In rxrpc_activate_channels(), the connection cache state is checked outside of the lock, which means it can change whilst we're waking calls up, thereby changing whether or not we're allowed to wake calls up. Fix this by moving the check inside the locked region. The check to see if all the channels are currently busy can stay outside of the locked region. Whilst we're at it: (1) Split the locked section out into its own function so that we can call it from other places in a later patch. (2) Determine the mask of channels dependent on the state as we're going to add another state in a later patch that will restrict the number of simultaneous calls to 1 on a connection. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix exclusive client connectionsDavid Howells2016-09-291-1/+1
| | | | | | | | | | | Exclusive connections are currently reusable (which they shouldn't be) because rxrpc_alloc_client_connection() checks the exclusive flag in the rxrpc_connection struct before it's initialised from the function parameters. This means that the DONT_REUSE flag doesn't get set. Fix this by checking the function parameters for the exclusive flag. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add connection tracepoint and client conn state tracepointDavid Howells2016-09-171-25/+57
| | | | | | | Add a pair of tracepoints, one to track rxrpc_connection struct ref counting and the other to track the client connection cache state. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix unexposed client conn releaseDavid Howells2016-09-171-1/+0
| | | | | | | | | | | | | | | | | | | | If the last call on a client connection is release after the connection has had a bunch of calls allocated but before any DATA packets are sent (so that it's not yet marked RXRPC_CONN_EXPOSED), an assertion will happen in rxrpc_disconnect_client_call(). af_rxrpc: Assertion failed - 1(0x1) >= 2(0x2) is false ------------[ cut here ]------------ kernel BUG at ../net/rxrpc/conn_client.c:753! This is because it's expecting the conn to have been exposed and to have 2 or more refs - but this isn't necessarily the case. Simply remove the assertion. This allows the conn to be moved into the inactive state and deleted if it isn't resurrected before the final put is called. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix the putting of client connectionsDavid Howells2016-09-171-15/+13
| | | | | | | | | | | | | | | | | | | In rxrpc_put_one_client_conn(), if a connection has RXRPC_CONN_COUNTED set on it, then it's accounted for in rxrpc_nr_client_conns and may be on various lists - and this is cleaned up correctly. However, if the connection doesn't have RXRPC_CONN_COUNTED set on it, then the put routine returns rather than just skipping the extra bit of cleanup. Fix this by making the extra bit of clean up conditional instead and always killing off the connection. This manifests itself as connections with a zero usage count hanging around in /proc/net/rxrpc_conns because the connection allocated, but discarded, due to a race with another process that set up a parallel connection, which was then shared instead. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Cache the security index in the rxrpc_call structDavid Howells2016-09-071-0/+3
| | | | | | | | Cache the security index in the rxrpc_call struct so that we can get at it even when the call has been disconnected and the connection pointer cleared. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Don't change the epochDavid Howells2016-09-041-24/+8
| | | | | | | It seems the local epoch should only be changed on boot, so remove the code that changes it for client connections. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: The client call state must be changed before attachment to connDavid Howells2016-09-041-0/+4
| | | | | | | | | | We must set the client call state to RXRPC_CALL_CLIENT_SEND_REQUEST before attaching the call to the connection struct, not after, as it's liable to receive errors and conn aborts as soon as the assignment is made - and these will cause its state to be changed outside of the initiating thread's control. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Trace rxrpc_call usageDavid Howells2016-08-301-0/+1
| | | | | | Add a trace event for debuging rxrpc_call struct usage. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Calls should only have one terminal stateDavid Howells2016-08-301-1/+1
| | | | | | | | | | | Condense the terminal states of a call state machine to a single state, plus a separate completion type value. The value is then set, along with error and abort code values, only when the call is transitioned to the completion state. Helpers are provided to simplify this. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Improve management and caching of client connection objectsDavid Howells2016-08-241-115/+795
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Improve the management and caching of client rxrpc connection objects. From this point, client connections will be managed separately from service connections because AF_RXRPC controls the creation and re-use of client connections but doesn't have that luxury with service connections. Further, there will be limits on the numbers of client connections that may be live on a machine. No direct restriction will be placed on the number of client calls, excepting that each client connection can support a maximum of four concurrent calls. Note that, for a number of reasons, we don't want to simply discard a client connection as soon as the last call is apparently finished: (1) Security is negotiated per-connection and the context is then shared between all calls on that connection. The context can be negotiated again if the connection lapses, but that involves holding up calls whilst at least two packets are exchanged and various crypto bits are performed - so we'd ideally like to cache it for a little while at least. (2) If a packet goes astray, we will need to retransmit a final ACK or ABORT packet. To make this work, we need to keep around the connection details for a little while. (3) The locally held structures represent some amount of setup time, to be weighed against their occupation of memory when idle. To this end, the client connection cache is managed by a state machine on each connection. There are five states: (1) INACTIVE - The connection is not held in any list and may not have been exposed to the world. If it has been previously exposed, it was discarded from the idle list after expiring. (2) WAITING - The connection is waiting for the number of client conns to drop below the maximum capacity. Calls may be in progress upon it from when it was active and got culled. The connection is on the rxrpc_waiting_client_conns list which is kept in to-be-granted order. Culled conns with waiters go to the back of the queue just like new conns. (3) ACTIVE - The connection has at least one call in progress upon it, it may freely grant available channels to new calls and calls may be waiting on it for channels to become available. The connection is on the rxrpc_active_client_conns list which is kept in activation order for culling purposes. (4) CULLED - The connection got summarily culled to try and free up capacity. Calls currently in progress on the connection are allowed to continue, but new calls will have to wait. There can be no waiters in this state - the conn would have to go to the WAITING state instead. (5) IDLE - The connection has no calls in progress upon it and must have been exposed to the world (ie. the EXPOSED flag must be set). When it expires, the EXPOSED flag is cleared and the connection transitions to the INACTIVE state. The connection is on the rxrpc_idle_client_conns list which is kept in order of how soon they'll expire. A connection in the ACTIVE or CULLED state must have at least one active call upon it; if in the WAITING state it may have active calls upon it; other states may not have active calls. As long as a connection remains active and doesn't get culled, it may continue to process calls - even if there are connections on the wait queue. This simplifies things a bit and reduces the amount of checking we need do. There are a couple flags of relevance to the cache: (1) EXPOSED - The connection ID got exposed to the world. If this flag is set, an extra ref is added to the connection preventing it from being reaped when it has no calls outstanding. This flag is cleared and the ref dropped when a conn is discarded from the idle list. (2) DONT_REUSE - The connection should be discarded as soon as possible and should not be reused. This commit also provides a number of new settings: (*) /proc/net/rxrpc/max_client_conns The maximum number of live client connections. Above this number, new connections get added to the wait list and must wait for an active conn to be culled. Culled connections can be reused, but they will go to the back of the wait list and have to wait. (*) /proc/net/rxrpc/reap_client_conns If the number of desired connections exceeds the maximum above, the active connection list will be culled until there are only this many left in it. (*) /proc/net/rxrpc/idle_conn_expiry The normal expiry time for a client connection, provided there are fewer than reap_client_conns of them around. (*) /proc/net/rxrpc/idle_conn_fast_expiry The expedited expiry time, used when there are more than reap_client_conns of them around. Note that I combined the Tx wait queue with the channel grant wait queue to save space as only one of these should be in use at once. Note also that, for the moment, the service connection cache still uses the old connection management code. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Dup the main conn list for the proc interfaceDavid Howells2016-08-241-0/+1
| | | | | | | | | | | | | | | | | The main connection list is used for two independent purposes: primarily it is used to find connections to reap and secondarily it is used to list connections in procfs. Split the procfs list out from the reap list. This allows us to stop using the reap list for client connections when they acquire a separate management strategy from service collections. The client connections will not be on a management single list, and sometimes won't be on a management list at all. This doesn't leave them floating, however, as they will also be on an rb-tree rooted on the socket so that the socket can find them to dispatch calls. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Make /proc/net/rxrpc_calls saferDavid Howells2016-08-241-0/+1
| | | | | | | | | | Make /proc/net/rxrpc_calls safer by stashing a copy of the peer pointer in the rxrpc_call struct and checking in the show routine that the peer pointer, the socket pointer and the local pointer obtained from the socket pointer aren't NULL before we use them. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Drop channel number field from rxrpc_call structDavid Howells2016-08-231-1/+0
| | | | | | | | | Drop the channel number (channel) field from the rxrpc_call struct to reduce the size of the call struct. The field is redundant: if the call is attached to a connection, the channel can be obtained from there by AND'ing with RXRPC_CHANNELMASK. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Tidy up the rxrpc_call struct a bitDavid Howells2016-08-231-1/+0
| | | | | | | | | | | | | | | | | | Do a little tidying of the rxrpc_call struct: (1) in_clientflag is no longer compared against the value that's in the packet, so keeping it in this form isn't necessary. Use a flag in flags instead and provide a pair of wrapper functions. (2) We don't read the epoch value, so that can go. (3) Move what remains of the data that were used for hashing up in the struct to be with the channel number. (4) Get rid of the local pointer. We can get at this via the socket struct and we only use this in the procfs viewer. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Use RCU to access a peer's service connection treeDavid Howells2016-07-061-2/+0
| | | | | | | | | | | | | | | | | | | | Move to using RCU access to a peer's service connection tree when routing an incoming packet. This is done using a seqlock to trigger retrying of the tree walk if a change happened. Further, we no longer get a ref on the connection looked up in the data_ready handler unless we queue the connection's work item - and then only if the refcount > 0. Note that I'm avoiding the use of a hash table for service connections because each service connection is addressed by a 62-bit number (constructed from epoch and connection ID >> 2) that would allow the client to engage in bucket stuffing, given knowledge of the hash algorithm. Peers, however, are hashed as the network address is less controllable by the client. The total number of peers will also be limited in a future commit. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Prune the contents of the rxrpc_conn_proto structDavid Howells2016-07-061-11/+0
| | | | | | | Prune the contents of the rxrpc_conn_proto struct. Most of the fields aren't used anymore. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Maintain an extra ref on a conn for the cache listDavid Howells2016-07-061-8/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Overhaul the usage count accounting for the rxrpc_connection struct to make it easier to implement RCU access from the data_ready handler. The problem is that currently we're using a lock to prevent the garbage collector from trying to clean up a connection that we're contemplating unidling. We could just stick incoming packets on the connection we find, but we've then got a problem that we may race when dispatching a work item to process it as we need to give that a ref to prevent the rxrpc_connection struct from disappearing in the meantime. Further, incoming packets may get discarded if attached to an rxrpc_connection struct that is going away. Whilst this is not a total disaster - the client will presumably resend - it would delay processing of the call. This would affect the AFS client filesystem's service manager operation. To this end: (1) We now maintain an extra count on the connection usage count whilst it is on the connection list. This mean it is not in use when its refcount is 1. (2) When trying to reuse an old connection, we only increment the refcount if it is greater than 0. If it is 0, we replace it in the tree with a new candidate connection. (3) Two connection flags are added to indicate whether or not a connection is in the local's client connection tree (used by sendmsg) or the peer's service connection tree (used by data_ready). This makes sure that we don't try and remove a connection if it got replaced. The flags are tested under lock with the removal operation to prevent the reaper from killing the rxrpc_connection struct whilst someone else is trying to effect a replacement. This could probably be alleviated by using memory barriers between the flag set/test and the rb_tree ops. The rb_tree op would still need to be under the lock, however. (4) When trying to reap an old connection, we try to flip the usage count from 1 to 0. If it's not 1 at that point, then it must've come back to life temporarily and we ignore it. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Split client connection code out into its own fileDavid Howells2016-07-061-1/+247
| | | | | | | | Split the client-specific connection code out into its own file. It will behave somewhat differently from the service-specific connection code, so it makes sense to separate them. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Check that the client conns cache is empty before module removalDavid Howells2016-07-061-0/+19
| | | | | | | | | Check that the client conns cache is empty before module removal and bug if not, listing any offending connections that are still present. Unfortunately, if there are connections still around, then the transport socket is still unexpectedly open and active, so we can't just unallocate the connections. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Kill the client connection bundle conceptDavid Howells2016-06-221-6/+1
| | | | | | | | | | | | Kill off the concept of maintaining a bundle of connections to a particular target service to increase the number of call slots available for any beyond four for that service (there are four call slots per connection). This will make cleaning up the connection handling code easier and facilitate removal of the rxrpc_transport struct. Bundling can be reintroduced later if necessary. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Use IDR to allocate client conn IDs on a machine-wide basisDavid Howells2016-06-221-0/+99
Use the IDR facility to allocate client connection IDs on a machine-wide basis so that each client connection has a unique identifier. When the connection ID space wraps, we advance the epoch by 1, thereby effectively having a 62-bit ID space. The IDR facility is then used to look up client connections during incoming packet routing instead of using an rbtree rooted on the transport. This change allows for the removal of the transport in the future and also means that client connections can be looked up directly in the data-ready handler by connection ID. The ID management code is placed in a new file, conn-client.c, to which all the client connection-specific code will eventually move. Note that the IDR tree gets very expensive on memory if the connection IDs are widely scattered throughout the number space, so we shall need to retire connections that have, say, an ID more than four times the maximum number of client conns away from the current allocation point to try and keep the IDs concentrated. We will also need to retire connections from an old epoch. Also note that, for the moment, a pointer to the transport has to be passed through into the ID allocation function so that we can take a BH lock to prevent a locking issue against in-BH lookup of client connections. This will go away later when RCU is used for server connections also. Signed-off-by: David Howells <dhowells@redhat.com>