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path: root/fs/afs/rxrpc.c
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2016-10-13afs: call->operation_ID sometimes used as __be32 sometimes as u32David Howells
call->operation_ID is sometimes being used as __be32 sometimes is being used as u32. Be consistent and settle on using as u32. Signed-off-by: David Howells <dhowells@redhat.com.
2016-10-06afs: Check for fatal error when in waiting for ack stateDavid Howells
When it's in the waiting-for-ACK state, the AFS filesystem needs to check the result of rxrpc_kernel_recv_data() any time it is notified to see if it is indicating a fatal error. If this is the case, it needs to mark the call completed otherwise the call just sits there and never goes away. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08rxrpc: Rewrite the data and ack handling codeDavid Howells
Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08rxrpc: Preallocate peers, conns and calls for incoming service requestsDavid Howells
Make it possible for the data_ready handler called from the UDP transport socket to completely instantiate an rxrpc_call structure and make it immediately live by preallocating all the memory it might need. The idea is to cut out the background thread usage as much as possible. [Note that the preallocated structs are not actually used in this patch - that will be done in a future patch.] If insufficient resources are available in the preallocation buffers, it will be possible to discard the DATA packet in the data_ready handler or schedule a BUSY packet without the need to schedule an attempt at allocation in a background thread. To this end: (1) Preallocate rxrpc_peer, rxrpc_connection and rxrpc_call structs to a maximum number each of the listen backlog size. The backlog size is limited to a maxmimum of 32. Only this many of each can be in the preallocation buffer. (2) For userspace sockets, the preallocation is charged initially by listen() and will be recharged by accepting or rejecting pending new incoming calls. (3) For kernel services {,re,dis}charging of the preallocation buffers is handled manually. Two notifier callbacks have to be provided before kernel_listen() is invoked: (a) An indication that a new call has been instantiated. This can be used to trigger background recharging. (b) An indication that a call is being discarded. This is used when the socket is being released. A function, rxrpc_kernel_charge_accept() is called by the kernel service to preallocate a single call. It should be passed the user ID to be used for that call and a callback to associate the rxrpc call with the kernel service's side of the ID. (4) Discard the preallocation when the socket is closed. (5) Temporarily bump the refcount on the call allocated in rxrpc_incoming_call() so that rxrpc_release_call() can ditch the preallocation ref on service calls unconditionally. This will no longer be necessary once the preallocation is used. Note that this does not yet control the number of active service calls on a client - that will come in a later patch. A future development would be to provide a setsockopt() call that allows a userspace server to manually charge the preallocation buffer. This would allow user call IDs to be provided in advance and the awkward manual accept stage to be bypassed. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-07rxrpc: Add tracepoint for working out where aborts happenDavid Howells
Add a tracepoint for working out where local aborts happen. Each tracepoint call is labelled with a 3-letter code so that they can be distinguished - and the DATA sequence number is added too where available. rxrpc_kernel_abort_call() also takes a 3-letter code so that AFS can indicate the circumstances when it aborts a call. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-04fs/afs/rxrpc: Remove deprecated create_singlethread_workqueueBhaktipriya Shridhar
The workqueue "afs_async_calls" queues work item &call->async_work per afs_call. Since there could be multiple calls and since these calls can be run concurrently, alloc_workqueue has been used to replace the deprecated create_singlethread_workqueue instance. The WQ_MEM_RECLAIM flag has been set to ensure forward progress under memory pressure because the workqueue is being used on a memory reclaim path. Since there are fixed number of work items, explicit concurrency limit is unnecessary here. Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-01rxrpc: Don't expose skbs to in-kernel users [ver #2]David Howells
Don't expose skbs to in-kernel users, such as the AFS filesystem, but instead provide a notification hook the indicates that a call needs attention and another that indicates that there's a new call to be collected. This makes the following possibilities more achievable: (1) Call refcounting can be made simpler if skbs don't hold refs to calls. (2) skbs referring to non-data events will be able to be freed much sooner rather than being queued for AFS to pick up as rxrpc_kernel_recv_data will be able to consult the call state. (3) We can shortcut the receive phase when a call is remotely aborted because we don't have to go through all the packets to get to the one cancelling the operation. (4) It makes it easier to do encryption/decryption directly between AFS's buffers and sk_buffs. (5) Encryption/decryption can more easily be done in the AFS's thread contexts - usually that of the userspace process that issued a syscall - rather than in one of rxrpc's background threads on a workqueue. (6) AFS will be able to wait synchronously on a call inside AF_RXRPC. To make this work, the following interface function has been added: int rxrpc_kernel_recv_data( struct socket *sock, struct rxrpc_call *call, void *buffer, size_t bufsize, size_t *_offset, bool want_more, u32 *_abort_code); This is the recvmsg equivalent. It allows the caller to find out about the state of a specific call and to transfer received data into a buffer piecemeal. afs_extract_data() and rxrpc_kernel_recv_data() now do all the extraction logic between them. They don't wait synchronously yet because the socket lock needs to be dealt with. Five interface functions have been removed: rxrpc_kernel_is_data_last() rxrpc_kernel_get_abort_code() rxrpc_kernel_get_error_number() rxrpc_kernel_free_skb() rxrpc_kernel_data_consumed() As a temporary hack, sk_buffs going to an in-kernel call are queued on the rxrpc_call struct (->knlrecv_queue) rather than being handed over to the in-kernel user. To process the queue internally, a temporary function, temp_deliver_data() has been added. This will be replaced with common code between the rxrpc_recvmsg() path and the kernel_rxrpc_recv_data() path in a future patch. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-30rxrpc: Pass struct socket * to more rxrpc kernel interface functionsDavid Howells
Pass struct socket * to more rxrpc kernel interface functions. They should be starting from this rather than the socket pointer in the rxrpc_call struct if they need to access the socket. I have left: rxrpc_kernel_is_data_last() rxrpc_kernel_get_abort_code() rxrpc_kernel_get_error_number() rxrpc_kernel_free_skb() rxrpc_kernel_data_consumed() unmodified as they're all about to be removed (and, in any case, don't touch the socket). Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-30rxrpc: Provide a way for AFS to ask for the peer address of a callDavid Howells
Provide a function so that kernel users, such as AFS, can ask for the peer address of a call: void rxrpc_kernel_get_peer(struct rxrpc_call *call, struct sockaddr_rxrpc *_srx); In the future the kernel service won't get sk_buffs to look inside. Further, this allows us to hide any canonicalisation inside AF_RXRPC for when IPv6 support is added. Also propagate this through to afs_find_server() and issue a warning if we can't handle the address family yet. Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-06rxrpc: Fix races between skb free, ACK generation and replyingDavid Howells
Inside the kafs filesystem it is possible to occasionally have a call processed and terminated before we've had a chance to check whether we need to clean up the rx queue for that call because afs_send_simple_reply() ends the call when it is done, but this is done in a workqueue item that might happen to run to completion before afs_deliver_to_call() completes. Further, it is possible for rxrpc_kernel_send_data() to be called to send a reply before the last request-phase data skb is released. The rxrpc skb destructor is where the ACK processing is done and the call state is advanced upon release of the last skb. ACK generation is also deferred to a work item because it's possible that the skb destructor is not called in a context where kernel_sendmsg() can be invoked. To this end, the following changes are made: (1) kernel_rxrpc_data_consumed() is added. This should be called whenever an skb is emptied so as to crank the ACK and call states. This does not release the skb, however. kernel_rxrpc_free_skb() must now be called to achieve that. These together replace rxrpc_kernel_data_delivered(). (2) kernel_rxrpc_data_consumed() is wrapped by afs_data_consumed(). This makes afs_deliver_to_call() easier to work as the skb can simply be discarded unconditionally here without trying to work out what the return value of the ->deliver() function means. The ->deliver() functions can, via afs_data_complete(), afs_transfer_reply() and afs_extract_data() mark that an skb has been consumed (thereby cranking the state) without the need to conditionally free the skb to make sure the state is correct on an incoming call for when the call processor tries to send the reply. (3) rxrpc_recvmsg() now has to call kernel_rxrpc_data_consumed() when it has finished with a packet and MSG_PEEK isn't set. (4) rxrpc_packet_destructor() no longer calls rxrpc_hard_ACK_data(). Because of this, we no longer need to clear the destructor and put the call before we free the skb in cases where we don't want the ACK/call state to be cranked. (5) The ->deliver() call-type callbacks are made to return -EAGAIN rather than 0 if they expect more data (afs_extract_data() returns -EAGAIN to the delivery function already), and the caller is now responsible for producing an abort if that was the last packet. (6) There are many bits of unmarshalling code where: ret = afs_extract_data(call, skb, last, ...); switch (ret) { case 0: break; case -EAGAIN: return 0; default: return ret; } is to be found. As -EAGAIN can now be passed back to the caller, we now just return if ret < 0: ret = afs_extract_data(call, skb, last, ...); if (ret < 0) return ret; (7) Checks for trailing data and empty final data packets has been consolidated as afs_data_complete(). So: if (skb->len > 0) return -EBADMSG; if (!last) return 0; becomes: ret = afs_data_complete(call, skb, last); if (ret < 0) return ret; (8) afs_transfer_reply() now checks the amount of data it has against the amount of data desired and the amount of data in the skb and returns an error to induce an abort if we don't get exactly what we want. Without these changes, the following oops can occasionally be observed, particularly if some printks are inserted into the delivery path: general protection fault: 0000 [#1] SMP Modules linked in: kafs(E) af_rxrpc(E) [last unloaded: af_rxrpc] CPU: 0 PID: 1305 Comm: kworker/u8:3 Tainted: G E 4.7.0-fsdevel+ #1303 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 Workqueue: kafsd afs_async_workfn [kafs] task: ffff88040be041c0 ti: ffff88040c070000 task.ti: ffff88040c070000 RIP: 0010:[<ffffffff8108fd3c>] [<ffffffff8108fd3c>] __lock_acquire+0xcf/0x15a1 RSP: 0018:ffff88040c073bc0 EFLAGS: 00010002 RAX: 6b6b6b6b6b6b6b6b RBX: 0000000000000000 RCX: ffff88040d29a710 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88040d29a710 RBP: ffff88040c073c70 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88040be041c0 R15: ffffffff814c928f FS: 0000000000000000(0000) GS:ffff88041fa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa4595f4750 CR3: 0000000001c14000 CR4: 00000000001406f0 Stack: 0000000000000006 000000000be04930 0000000000000000 ffff880400000000 ffff880400000000 ffffffff8108f847 ffff88040be041c0 ffffffff81050446 ffff8803fc08a920 ffff8803fc08a958 ffff88040be041c0 ffff88040c073c38 Call Trace: [<ffffffff8108f847>] ? mark_held_locks+0x5e/0x74 [<ffffffff81050446>] ? __local_bh_enable_ip+0x9b/0xa1 [<ffffffff8108f9ca>] ? trace_hardirqs_on_caller+0x16d/0x189 [<ffffffff810915f4>] lock_acquire+0x122/0x1b6 [<ffffffff810915f4>] ? lock_acquire+0x122/0x1b6 [<ffffffff814c928f>] ? skb_dequeue+0x18/0x61 [<ffffffff81609dbf>] _raw_spin_lock_irqsave+0x35/0x49 [<ffffffff814c928f>] ? skb_dequeue+0x18/0x61 [<ffffffff814c928f>] skb_dequeue+0x18/0x61 [<ffffffffa009aa92>] afs_deliver_to_call+0x344/0x39d [kafs] [<ffffffffa009ab37>] afs_process_async_call+0x4c/0xd5 [kafs] [<ffffffffa0099e9c>] afs_async_workfn+0xe/0x10 [kafs] [<ffffffff81063a3a>] process_one_work+0x29d/0x57c [<ffffffff81064ac2>] worker_thread+0x24a/0x385 [<ffffffff81064878>] ? rescuer_thread+0x2d0/0x2d0 [<ffffffff810696f5>] kthread+0xf3/0xfb [<ffffffff8160a6ff>] ret_from_fork+0x1f/0x40 [<ffffffff81069602>] ? kthread_create_on_node+0x1cf/0x1cf Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10rxrpc: Limit the listening backlogDavid Howells
Limit the socket incoming call backlog queue size so that a remote client can't pump in sufficient new calls that the server runs out of memory. Note that this is partially theoretical at the moment since whilst the number of calls is limited, the number of packets trying to set up new calls is not. This will be addressed in a later patch. If the caller of listen() specifies a backlog INT_MAX, then they get the current maximum; anything else greater than max_backlog or anything negative incurs EINVAL. The limit on the maximum queue size can be set by: echo N >/proc/sys/net/rxrpc/max_backlog where 4<=N<=32. Further, set the default backlog to 0, requiring listen() to be called before we start actually queueing new calls. Whilst this kind of is a change in the UAPI, the caller can't actually *accept* new calls anyway unless they've first called listen() to put the socket into the LISTENING state - thus the aforementioned new calls would otherwise just sit there, eating up kernel memory. (Note that sockets that don't have a non-zero service ID bound don't get incoming calls anyway.) Given that the default backlog is now 0, make the AFS filesystem call kernel_listen() to set the maximum backlog for itself. Possible improvements include: (1) Trimming a too-large backlog to max_backlog when listen is called. (2) Trimming the backlog value whenever the value is used so that changes to max_backlog are applied to an open socket automatically. Note that the AFS filesystem opens one socket and keeps it open for extended periods, so would miss out on changes to max_backlog. (3) Having a separate setting for the AFS filesystem. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11rxrpc: Differentiate local and remote abort codes in structsDavid Howells
In the rxrpc_connection and rxrpc_call structs, there's one field to hold the abort code, no matter whether that value was generated locally to be sent or was received from the peer via an abort packet. Split the abort code fields in two for cleanliness sake and add an error field to hold the Linux error number to the rxrpc_call struct too (sometimes this is generated in a context where we can't return it to userspace directly). Furthermore, add a skb mark to indicate a packet that caused a local abort to be generated so that recvmsg() can pick up the correct abort code. A future addition will need to be to indicate to userspace the difference between aborts via a control message. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11afs: Wait for outstanding async calls before closing rxrpc socketDavid Howells
The afs filesystem needs to wait for any outstanding asynchronous calls (such as FS.GiveUpCallBacks cleaning up the callbacks lodged with a server) to complete before closing the AF_RXRPC socket when unloading the module. This may occur if the module is removed too quickly after unmounting all filesystems. This will produce an error report that looks like: AFS: Assertion failed 1 == 0 is false 0x1 == 0x0 is false ------------[ cut here ]------------ kernel BUG at ../fs/afs/rxrpc.c:135! ... RIP: 0010:[<ffffffffa004111c>] afs_close_socket+0xec/0x107 [kafs] ... Call Trace: [<ffffffffa004a160>] afs_exit+0x1f/0x57 [kafs] [<ffffffff810c30a0>] SyS_delete_module+0xec/0x17d [<ffffffff81610417>] entry_SYSCALL_64_fastpath+0x12/0x6b Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11net: Add a struct net parameter to sock_create_kernEric W. Biederman
This is long overdue, and is part of cleaning up how we allocate kernel sockets that don't reference count struct net. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-01AFS: afs_send_empty_reply() doesn't require an iovec arrayDavid Howells
afs_send_empty_reply() doesn't require an iovec array with which to initialise the msghdr, but can pass NULL instead. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com>
2015-02-04rxrpc: make the users of rxrpc_kernel_send_data() set kvec-backed msg_iter ↵Al Viro
properly Use iov_iter_kvec() there, get rid of set_fs() games - now that rxrpc_send_data() uses iov_iter primitives, it'll handle ITER_KVEC just fine. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-09put iov_iter into msghdrAl Viro
Note that the code _using_ ->msg_iter at that point will be very unhappy with anything other than unshifted iovec-backed iov_iter. We still need to convert users to proper primitives. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-23AFS: Pass an afs_call* to call->async_workfn() instead of a work_struct*David Howells
call->async_workfn() can take an afs_call* arg rather than a work_struct* as the functions assigned there are now called from afs_async_workfn() which has to call container_of() anyway. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Nathaniel Wesley Filardo <nwf@cs.jhu.edu> Reviewed-by: Tejun Heo <tj@kernel.org>
2014-05-23AFS: Fix kafs module unloadingNathaniel Wesley Filardo
At present, it is not possible to successfully unload the kafs module if there are outstanding async outgoing calls (those made with afs_make_call()). This appears to be due to the changes introduced by: commit 059499453a9abd1857d442b44da8b4c126dc72a8 Author: Tejun Heo <tj@kernel.org> Date: Fri Mar 7 10:24:50 2014 -0500 Subject: afs: don't use PREPARE_WORK which didn't go far enough. The problem is due to: (1) The aforementioned commit introduced a separate handler function pointer in the call, call->async_workfn, in addition to the original workqueue item, call->async_work, for asynchronous operations because workqueues subsystem cannot handle the workqueue item pointer being changed whilst the item is queued or being processed. (2) afs_async_workfn() was introduced in that commit to be the callback for call->async_work. Its sole purpose is to run whatever call->async_workfn points to. (3) call->async_workfn is only used from afs_async_workfn(), which is only set on async_work by afs_collect_incoming_call() - ie. for incoming calls. (4) call->async_workfn is *not* set by afs_make_call() when outgoing calls are made, and call->async_work is set afs_process_async_call() - and not afs_async_workfn(). (5) afs_process_async_call() now changes call->async_workfn rather than call->async_work to point to afs_delete_async_call() to clean up, but this is only effective for incoming calls because call->async_work does not point to afs_async_workfn() for outgoing calls. (6) Because, for incoming calls, call->async_work remains pointing to afs_process_async_call() this results in an infinite loop. Instead, make the workqueue uniformly vector through call->async_workfn, via afs_async_workfn() and simply initialise call->async_workfn to point to afs_process_async_call() in afs_make_call(). Signed-off-by: Nathaniel Wesley Filardo <nwf@cs.jhu.edu> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Tejun Heo <tj@kernel.org>
2014-05-23AFS: Part of afs_end_call() is identical to code elsewhere, so split itNathaniel Wesley Filardo
Split afs_end_call() into two pieces, one of which is identical to code in afs_process_async_call(). Replace the latter with a call to the first part of afs_end_call(). Signed-off-by: Nathaniel Wesley Filardo <nwf@cs.jhu.edu> Signed-off-by: David Howells <dhowells@redhat.com>
2014-05-21AFS: Fix cache manager service handlersDavid Howells
Fix the cache manager RPC service handlers. The afs_send_empty_reply() and afs_send_simple_reply() functions: (a) Kill the call and free up the buffers associated with it if they fail. (b) Return with call intact if it they succeed. However, none of the callers actually check the result or clean up if successful - and may use the now non-existent data if it fails. This was detected by Dan Carpenter using a static checker: The patch 08e0e7c82eea: "[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC." from Apr 26, 2007, leads to the following static checker warning: "fs/afs/cmservice.c:155 SRXAFSCB_CallBack() warn: 'call' was already freed." Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David Howells <dhowells@redhat.com>
2014-03-07afs: don't use PREPARE_WORKTejun Heo
PREPARE_[DELAYED_]WORK() are being phased out. They have few users and a nasty surprise in terms of reentrancy guarantee as workqueue considers work items to be different if they don't have the same work function. afs_call->async_work is multiplexed with multiple work functions. Introduce afs_async_workfn() which invokes afs_call->async_workfn and always use it as the work function and update the users to set the ->async_workfn field instead of overriding the work function using PREPARE_WORK(). It would probably be best to route this with other related updates through the workqueue tree. Compile tested. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: linux-afs@lists.infradead.org
2012-03-16afs: Remote abort can cause BUG in rxrpc codeAnton Blanchard
When writing files to afs I sometimes hit a BUG: kernel BUG at fs/afs/rxrpc.c:179! With a backtrace of: afs_free_call afs_make_call afs_fs_store_data afs_vnode_store_data afs_write_back_from_locked_page afs_writepages_region afs_writepages The cause is: ASSERT(skb_queue_empty(&call->rx_queue)); Looking at a tcpdump of the session the abort happens because we are exceeding our disk quota: rx abort fs reply store-data error diskquota exceeded (32) So the abort error is valid. We hit the BUG because we haven't freed all the resources for the call. By freeing any skbs in call->rx_queue before calling afs_free_call we avoid hitting leaking memory and avoid hitting the BUG. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: David Howells <dhowells@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-14afs: add afs_wq and use it instead of the system workqueueTejun Heo
flush_scheduled_work() is going away. afs needs to make sure all the works it has queued have finished before being unloaded and there can be arbitrary number of pending works. Add afs_wq and use it as the flush domain instead of the system workqueue. Also, convert cancel_delayed_work() + flush_scheduled_work() to cancel_delayed_work_sync() in afs_mntpt_kill_timer(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: David Howells <dhowells@redhat.com> Cc: linux-afs@lists.infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-11afs: destroy work queue on init failureDan Carpenter
We can clean up the work queue on this error path. This function is called from afs_init(). Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2007-10-17fs/afs/: possible cleanupsAdrian Bunk
This patch contains the following possible cleanups: - make the following needlessly global functions static: - rxrpc.c: afs_send_pages() - vlocation.c: afs_vlocation_queue_for_updates() - write.c: afs_writepages_region() - make the following needlessly global variables static: - mntpt.c: afs_mntpt_expiry_timeout - proc.c: afs_vlocation_states[] - server.c: afs_server_timeout - vlocation.c: afs_vlocation_timeout - vlocation.c: afs_vlocation_update_timeout - #if 0 the following unused function: - cell.c: afs_get_cell_maybe() - #if 0 the following unused variables: - callback.c: afs_vnode_update_timeout - cmservice.c: struct afs_cm_workqueue Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20AFS: Use patched rxrpc_kernel_send_data() correctlyDavid Howells
Fix afs_send_simple_reply() to accept a greater-than-zero return value from rxrpc_kernel_send_data() as being a successful return rather than thinking it an error and aborting the call. rxrpc_kernel_send_data() previously returned zero incorrectly when it worked successfully, but has been patched to return the number of bytes it transmitted. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10AFS: further write support fixesDavid Howells
Further fixes for AFS write support: (1) The afs_send_pages() outer loop must do an extra iteration if it ends with 'first == last' because 'last' is inclusive in the page set otherwise it fails to send the last page and complete the RxRPC op under some circumstances. (2) Similarly, the outer loop in afs_pages_written_back() must also do an extra iteration if it ends with 'first == last', otherwise it fails to clear PG_writeback on the last page under some circumstances. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09AFS: implement basic file write supportDavid Howells
Implement support for writing to regular AFS files, including: (1) write (2) truncate (3) fsync, fdatasync (4) chmod, chown, chgrp, utime. AFS writeback attempts to batch writes into as chunks as large as it can manage up to the point that it writes back 65535 pages in one chunk or it meets a locked page. Furthermore, if a page has been written to using a particular key, then should another write to that page use some other key, the first write will be flushed before the second is allowed to take place. If the first write fails due to a security error, then the page will be scrapped and reread before the second write takes place. If a page is dirty and the callback on it is broken by the server, then the dirty data is not discarded (same behaviour as NFS). Shared-writable mappings are not supported by this patch. [akpm@linux-foundation.org: fix a bunch of warnings] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-27[AF_RXRPC/AFS]: Arch-specific fixes.David Howells
Fixes for various arch compilation problems: (*) Missing module exports. (*) Variable name collision when rxkad and af_rxrpc both built in (rxrpc_debug). (*) Large constant representation problem (AFS_UUID_TO_UNIX_TIME). (*) Configuration dependencies. (*) printk() format warnings. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26[AFS]: Add support for the CB.GetCapabilities operation.David Howells
Add support for the CB.GetCapabilities operation with which the fileserver can ask the client for the following information: (1) The list of network interfaces it has available as IPv4 address + netmask plus the MTUs. (2) The client's UUID. (3) The extended capabilities of the client, for which the only current one is unified error mapping (abort code interpretation). To support this, the patch adds the following routines to AFS: (1) A function to iterate through all the network interfaces using RTNETLINK to extract IPv4 addresses and MTUs. (2) A function to iterate through all the network interfaces using RTNETLINK to pull out the MAC address of the lowest index interface to use in UUID construction. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26[AFS]: Add security support.David Howells
Add security support to the AFS filesystem. Kerberos IV tickets are added as RxRPC keys are added to the session keyring with the klog program. open() and other VFS operations then find this ticket with request_key() and either use it immediately (eg: mkdir, unlink) or attach it to a file descriptor (open). Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC.David Howells
Make the in-kernel AFS filesystem use AF_RXRPC instead of the old RxRPC code. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>