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path: root/fs/dlm/lowcomms.c
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2022-11-21fs: dlm: don't put dlm_local_addrs on heapAlexander Aring
This patch removes to allocate the dlm_local_addr[] pointers on the heap. Instead we directly store the type of "struct sockaddr_storage". This removes function deinit_local() because it was freeing memory only. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-11-21fs: dlm: cleanup listen sock handlingAlexander Aring
This patch removes save_listen_callbacks() and add_listen_sock() as they are only used once in lowcomms functionality. For shutdown lowcomms it's not necessary to whole flush the workqueues to synchronize with restoring the old sk_data_ready() callback. Only the listen con receive work need to be cancelled. For each individual node shutdown we should be sure that last ack was been transmitted which is done by flushing per connection swork worker. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-11-21fs: dlm: remove socket shutdown handlingAlexander Aring
Since commit 489d8e559c65 ("fs: dlm: add reliable connection if reconnect") we have functionality like TCP offers for half-closed sockets on dlm application protocol layer. This feature is required because the cluster manager events about leaving resource memberships can be locally already occurred but other cluster nodes having a pending leaving membership over the cluster manager protocol happening. In this time the local dlm node already shutdown it's connection and don't transmit anymore any new dlm messages, but however it still needs to be able to accept dlm messages because the pending leave membership request of the cluster manager protocol which the dlm kernel implementation has no control about it. We have this functionality on the application for two reasons, the main reason is that SCTP does not support such functionality on socket layer. But we can do it inside application layer. Another small issue is that this feature is broken in the TCP world because some NAT devices does not implement such functionality correctly. This is the same reason why the reliable connection session layer in DLM exists. We give up on middle devices in the networking which sends e.g. TCP resets out. In DLM we cannot have any message dropping and we ensure it over a session layer that it can't happen. Back to the half-closed grace shutdown handling. It's not necessary anymore to do it on socket layer (which is only support for TCP sockets) because we do it on application layer. This patch removes this handling, if there are still issues then we have a problem on the application layer for such handling. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-11-21fs: dlm: use listen sock as dlm running indicatorAlexander Aring
This patch will switch from dlm_allow_conn to check if dlm lowcomms is running or not to if we actually have a listen socket set or not. The list socket will be set and unset in lowcomms start and shutdown functionality. To synchronize with data_ready() callback we will set the socket callback to NULL while socket lock is held. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-11-21fs: dlm: use list_first_entry_or_nullAlexander Aring
Instead of check on list_empty() we can do the same with list_first_entry_or_null() and return NULL if the returned value is NULL. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-11-21fs: dlm: remove twice INIT_WORKAlexander Aring
This patch removed a twice INIT_WORK() functionality. We already doing this inside of dlm_lowcomms_init() functionality which is called only once dlm is loaded. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-11-21fs: dlm: add midcomms init/start functionsAlexander Aring
This patch introduces leftovers of init, start, stop and exit functionality. The dlm application layer should always call the midcomms layer which getting aware of such event and redirect it to the lowcomms layer. Some functionality which is currently handled inside the start functionality of midcomms and lowcomms should be handled in the init functionality as it only need to be initialized once when dlm is loaded. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-11-08fs: dlm: relax sending to allow receivingAlexander Aring
This patch drops additionally the sock_mutex when there is a sending message burst. Since we have acknowledge handling we free sending buffers only when we receive an ack back, but if we are stuck in send_to_sock() looping because dlm sends a lot of messages and we never leave the loop the sending buffer fill up very quickly. We can't receive during this iteration because the sock_mutex is held. This patch will unlock the sock_mutex so it should be possible to receive messages when a burst of sending messages happens. This will allow to free up memory because acks which are already received can be processed. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-11-08fs: dlm: retry accept() until -EAGAIN or error returnsAlexander Aring
This patch fixes a race if we get two times an socket data ready event while the listen connection worker is queued. Currently it will be served only once but we need to do it (in this case twice) until we hit -EAGAIN which tells us there is no pending accept going on. This patch wraps an do while loop until we receive a return value which is different than 0 as it was done before commit d11ccd451b65 ("fs: dlm: listen socket out of connection hash"). Cc: stable@vger.kernel.org Fixes: d11ccd451b65 ("fs: dlm: listen socket out of connection hash") Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-11-08fs: dlm: fix sock release if listen failsAlexander Aring
This patch fixes a double sock_release() call when the listen() is called for the dlm lowcomms listen socket. The caller of dlm_listen_for_all should never care about releasing the socket if dlm_listen_for_all() fails, it's done now only once if listen() fails. Cc: stable@vger.kernel.org Fixes: 2dc6b1158c28 ("fs: dlm: introduce generic listen") Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-08-23fs: dlm: fix race in lowcommsAlexander Aring
This patch fixes a race between queue_work() in _dlm_lowcomms_commit_msg() and srcu_read_unlock(). The queue_work() can take the final reference of a dlm_msg and so msg->idx can contain garbage which is signaled by the following warning: [ 676.237050] ------------[ cut here ]------------ [ 676.237052] WARNING: CPU: 0 PID: 1060 at include/linux/srcu.h:189 dlm_lowcomms_commit_msg+0x41/0x50 [ 676.238945] Modules linked in: dlm_locktorture torture rpcsec_gss_krb5 intel_rapl_msr intel_rapl_common iTCO_wdt iTCO_vendor_support qxl kvm_intel drm_ttm_helper vmw_vsock_virtio_transport kvm vmw_vsock_virtio_transport_common ttm irqbypass crc32_pclmul joydev crc32c_intel serio_raw drm_kms_helper vsock virtio_scsi virtio_console virtio_balloon snd_pcm drm syscopyarea sysfillrect sysimgblt snd_timer fb_sys_fops i2c_i801 lpc_ich snd i2c_smbus soundcore pcspkr [ 676.244227] CPU: 0 PID: 1060 Comm: lock_torture_wr Not tainted 5.19.0-rc3+ #1546 [ 676.245216] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.16.0-2.module+el8.7.0+15506+033991b0 04/01/2014 [ 676.246460] RIP: 0010:dlm_lowcomms_commit_msg+0x41/0x50 [ 676.247132] Code: fe ff ff ff 75 24 48 c7 c6 bd 0f 49 bb 48 c7 c7 38 7c 01 bd e8 00 e7 ca ff 89 de 48 c7 c7 60 78 01 bd e8 42 3d cd ff 5b 5d c3 <0f> 0b eb d8 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 [ 676.249253] RSP: 0018:ffffa401c18ffc68 EFLAGS: 00010282 [ 676.249855] RAX: 0000000000000001 RBX: 00000000ffff8b76 RCX: 0000000000000006 [ 676.250713] RDX: 0000000000000000 RSI: ffffffffbccf3a10 RDI: ffffffffbcc7b62e [ 676.251610] RBP: ffffa401c18ffc70 R08: 0000000000000001 R09: 0000000000000001 [ 676.252481] R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000005 [ 676.253421] R13: ffff8b76786ec370 R14: ffff8b76786ec370 R15: ffff8b76786ec480 [ 676.254257] FS: 0000000000000000(0000) GS:ffff8b7777800000(0000) knlGS:0000000000000000 [ 676.255239] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 676.255897] CR2: 00005590205d88b8 CR3: 000000017656c003 CR4: 0000000000770ee0 [ 676.256734] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 676.257567] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 676.258397] PKRU: 55555554 [ 676.258729] Call Trace: [ 676.259063] <TASK> [ 676.259354] dlm_midcomms_commit_mhandle+0xcc/0x110 [ 676.259964] queue_bast+0x8b/0xb0 [ 676.260423] grant_pending_locks+0x166/0x1b0 [ 676.261007] _unlock_lock+0x75/0x90 [ 676.261469] unlock_lock.isra.57+0x62/0xa0 [ 676.262009] dlm_unlock+0x21e/0x330 [ 676.262457] ? lock_torture_stats+0x80/0x80 [dlm_locktorture] [ 676.263183] torture_unlock+0x5a/0x90 [dlm_locktorture] [ 676.263815] ? preempt_count_sub+0xba/0x100 [ 676.264361] ? complete+0x1d/0x60 [ 676.264777] lock_torture_writer+0xb8/0x150 [dlm_locktorture] [ 676.265555] kthread+0x10a/0x130 [ 676.266007] ? kthread_complete_and_exit+0x20/0x20 [ 676.266616] ret_from_fork+0x22/0x30 [ 676.267097] </TASK> [ 676.267381] irq event stamp: 9579855 [ 676.267824] hardirqs last enabled at (9579863): [<ffffffffbb14e6f8>] __up_console_sem+0x58/0x60 [ 676.268896] hardirqs last disabled at (9579872): [<ffffffffbb14e6dd>] __up_console_sem+0x3d/0x60 [ 676.270008] softirqs last enabled at (9579798): [<ffffffffbc200349>] __do_softirq+0x349/0x4c7 [ 676.271438] softirqs last disabled at (9579897): [<ffffffffbb0d54c0>] irq_exit_rcu+0xb0/0xf0 [ 676.272796] ---[ end trace 0000000000000000 ]--- I reproduced this warning with dlm_locktorture test which is currently not upstream. However this patch fix the issue by make a additional refcount between dlm_lowcomms_new_msg() and dlm_lowcomms_commit_msg(). In case of the race the kref_put() in dlm_lowcomms_commit_msg() will be the final put. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-06-24fs: dlm: fix grammar in lowcomms outputAlexander Aring
This patch fixes some grammar output in lowcomms implementation by removing the "successful" word which should be "successfully" but it can never be unsuccessfully so we remove it. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: add __CHECKER__ for false positivesAlexander Aring
This patch will adds #ifndef __CHECKER__ for false positives warnings about an imbalance lock/unlock srcu handling. Which are shown by running sparse checks: fs/dlm/midcomms.c:1065:20: warning: context imbalance in 'dlm_midcomms_get_mhandle' - wrong count at exit Using __CHECKER__ will tell sparse to ignore these sections. Those imbalances are false positive because from upper layer it is always required to call a function in sequence, e.g. if dlm_midcomms_get_mhandle() is successful there must be a dlm_midcomms_commit_mhandle() call afterwards. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: uninitialized variable on error in dlm_listen_for_all()Dan Carpenter
The "sock" variable is not initialized on this error path. Cc: stable@vger.kernel.org Fixes: 2dc6b1158c28 ("fs: dlm: introduce generic listen") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-01-04fs: dlm: print cluster addr if non-cluster node connectsAlexander Aring
This patch prints the cluster node address if a non-cluster node (according to the dlm config setting) tries to connect. The current hexdump call will print in a different loglevel and only available if dynamic debug is enabled. Additional we using the ip address format strings to print an IETF ip4/6 string represenation. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-12-07fs: dlm: memory cache for lowcomms hotpathAlexander Aring
This patch introduces a kmem cache for dlm_msg handles which are used always if dlm sends a message out. Even if their are covered by midcomms layer or not. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-12-07fs: dlm: memory cache for writequeue_entryAlexander Aring
This patch introduces a kmem cache for writequeue entry. A writequeue entry get quite a lot allocated if dlm transmit messages. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-12-07fs: dlm: remove wq_alloc mutexAlexander Aring
This patch cleanups the code for allocating a new buffer in the dlm writequeue mechanism. There was a possible tuneup to allow scheduling while a new writequeue entry needs to be allocated because either no sending page is available or are full. To avoid multiple concurrent users checking at the same time if an entry is available or full alloc_wq was introduce that those are waiting if there is currently a new writequeue entry in process to be queued so possible further users will check on the new allocated writequeue entry if it's full. To simplify the code we just remove this mutex and switch that the already introduced spin lock will be held during writequeue check, allocation and queueing. So other users can never check on available writequeues while there is a new one in process but not queued yet. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-12-07fs: dlm: check for pending users filling buffersAlexander Aring
Currently we don't care if the DLM application stack is filling buffers (not committed yet) while we transmit some already committed buffers. By checking on active writequeue users before dequeue a writequeue entry we know there is coming more data and do nothing. We wait until the send worker will be triggered again if the writequeue entry users hit zero. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-17fs: dlm: fix build with CONFIG_IPV6 disabledAlexander Aring
This patch will surround the AF_INET6 case in sk_error_report() of dlm with a #if IS_ENABLED(CONFIG_IPV6). The field sk->sk_v6_daddr is not defined when CONFIG_IPV6 is disabled. If CONFIG_IPV6 is disabled, the socket creation with AF_INET6 should already fail because a runtime check if AF_INET6 is registered. However if there is the possibility that AF_INET6 is set as sk_family the sk_error_report() callback will print then an invalid family type error. Reported-by: kernel test robot <lkp@intel.com> Fixes: 4c3d90570bcc ("fs: dlm: don't call kernel_getpeername() in error_report()") Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-15fs: dlm: replace use of socket sk_callback_lock with sock_lockAlexander Aring
This patch will replace the use of socket sk_callback_lock lock and uses socket lock instead. Some users like sunrpc, see commit ea9afca88bbe ("SUNRPC: Replace use of socket sk_callback_lock with sock_lock") moving from sk_callback_lock to sock_lock which seems to be held when the socket callbacks are called. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-15fs: dlm: don't call kernel_getpeername() in error_report()Alexander Aring
In some cases kernel_getpeername() will held the socket lock which is already held when the socket layer calls error_report() callback. Since commit 9dfc685e0262 ("inet: remove races in inet{6}_getname()") this problem becomes more likely because the socket lock will be held always. You will see something like: bob9-u5 login: [ 562.316860] BUG: spinlock recursion on CPU#7, swapper/7/0 [ 562.318562] lock: 0xffff8f2284720088, .magic: dead4ead, .owner: swapper/7/0, .owner_cpu: 7 [ 562.319522] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 5.15.0+ #135 [ 562.320346] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014 [ 562.321277] Call Trace: [ 562.321529] <IRQ> [ 562.321734] dump_stack_lvl+0x33/0x42 [ 562.322282] do_raw_spin_lock+0x8b/0xc0 [ 562.322674] lock_sock_nested+0x1e/0x50 [ 562.323057] inet_getname+0x39/0x110 [ 562.323425] ? sock_def_readable+0x80/0x80 [ 562.323838] lowcomms_error_report+0x63/0x260 [dlm] [ 562.324338] ? wait_for_completion_interruptible_timeout+0xd2/0x120 [ 562.324949] ? lock_timer_base+0x67/0x80 [ 562.325330] ? do_raw_spin_unlock+0x49/0xc0 [ 562.325735] ? _raw_spin_unlock_irqrestore+0x1e/0x40 [ 562.326218] ? del_timer+0x54/0x80 [ 562.326549] sk_error_report+0x12/0x70 [ 562.326919] tcp_validate_incoming+0x3c8/0x530 [ 562.327347] ? kvm_clock_read+0x14/0x30 [ 562.327718] ? ktime_get+0x3b/0xa0 [ 562.328055] tcp_rcv_established+0x121/0x660 [ 562.328466] tcp_v4_do_rcv+0x132/0x260 [ 562.328835] tcp_v4_rcv+0xcea/0xe20 [ 562.329173] ip_protocol_deliver_rcu+0x35/0x1f0 [ 562.329615] ip_local_deliver_finish+0x54/0x60 [ 562.330050] ip_local_deliver+0xf7/0x110 [ 562.330431] ? inet_rtm_getroute+0x211/0x840 [ 562.330848] ? ip_protocol_deliver_rcu+0x1f0/0x1f0 [ 562.331310] ip_rcv+0xe1/0xf0 [ 562.331603] ? ip_local_deliver+0x110/0x110 [ 562.332011] __netif_receive_skb_core+0x46a/0x1040 [ 562.332476] ? inet_gro_receive+0x263/0x2e0 [ 562.332885] __netif_receive_skb_list_core+0x13b/0x2c0 [ 562.333383] netif_receive_skb_list_internal+0x1c8/0x2f0 [ 562.333896] ? update_load_avg+0x7e/0x5e0 [ 562.334285] gro_normal_list.part.149+0x19/0x40 [ 562.334722] napi_complete_done+0x67/0x160 [ 562.335134] virtnet_poll+0x2ad/0x408 [virtio_net] [ 562.335644] __napi_poll+0x28/0x140 [ 562.336012] net_rx_action+0x23d/0x300 [ 562.336414] __do_softirq+0xf2/0x2ea [ 562.336803] irq_exit_rcu+0xc1/0xf0 [ 562.337173] common_interrupt+0xb9/0xd0 It is and was always forbidden to call kernel_getpeername() in context of error_report(). To get rid of the problem we access the destination address for the peer over the socket structure. While on it we fix to print out the destination port of the inet socket. Fixes: 1a31833d085a ("DLM: Replace nodeid_to_addr with kernel_getpeername") Reported-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-03fs: dlm: remove double list_first_entry callAlexander Aring
This patch removes a list_first_entry() call which is already done by the previous con_next_wq() call. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-02fs: dlm: let handle callback data as voidAlexander Aring
This patch changes the dlm_lowcomms_new_msg() function pointer private data from "struct mhandle *" to "void *" to provide different structures than just "struct mhandle". Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-02fs: dlm: trace socket handlingAlexander Aring
This patch adds tracepoints for dlm socket receive and send functionality. We can use it to track how much data was send or received to or from a specific nodeid. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-02fs: dlm: remove check SCTP is loaded messageAlexander Aring
Since commit 764ff4011424 ("fs: dlm: auto load sctp module") we try load the sctp module before we try to create a sctp kernel socket. That a socket creation fails now has more likely other reasons. This patch removes the part of error to load the sctp module and instead printout the error code. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-08-19fs: dlm: implement delayed ack handlingAlexander Aring
This patch changes that we don't ack each message. Lowcomms will take care about to send an ack back after a bulk of messages was processed. Currently it's only when the whole receive buffer was processed, there might better positions to send an ack back but only the lowcomms implementation know when there are more data to receive. This patch has also disadvantages that we might retransmit more on errors, however this is a very rare case. Tested with make_panic on gfs2 with three nodes by running: trace-cmd record -p function -l 'dlm_send_ack' sleep 100 and trace-cmd report | wc -l Before patch: - 20548 - 21376 - 21398 After patch: - 18338 - 20679 - 19949 Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-07-19fs: dlm: move receive loop into receive handlerAlexander Aring
This patch moves the kernel_recvmsg() loop call into the receive_from_sock() function instead of doing the loop outside the function and abort the loop over it's return value. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-07-19fs: dlm: fix multiple empty writequeue allocAlexander Aring
This patch will add a mutex that a connection can allocate a writequeue entry buffer only at a sleepable context at one time. If multiple caller waits at the writequeue spinlock and the spinlock gets release it could be that multiple new writequeue page buffers were allocated instead of allocate one writequeue page buffer and other waiters will use remaining buffer of it. It will only be the case for sleepable context which is the common case. In non-sleepable contexts like retransmission we just don't care about such behaviour. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-07-19fs: dlm: generic connect funcAlexander Aring
This patch adds a generic connect function for TCP and SCTP. If the connect functionality differs from each other additional callbacks in dlm_proto_ops were added. The sockopts callback handling will guarantee that sockets created by connect() will use the same options as sockets created by accept(). Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-07-19fs: dlm: auto load sctp moduleAlexander Aring
This patch adds a "for now" better handling of missing SCTP support in the kernel and try to load the sctp module if SCTP is set. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-07-19fs: dlm: introduce generic listenAlexander Aring
This patch combines each transport layer listen functionality into one listen function. Per transport layer differences are provided by additional callbacks in dlm_proto_ops. This patch drops silently sock_set_keepalive() for listen tcp sockets only. This socket option is not set at connecting sockets, I also don't see the sense of set keepalive for sockets which are created by accept() only. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-07-19fs: dlm: move to static proto opsAlexander Aring
This patch moves the per transport socket callbacks to a static const array. We can support only one transport socket for the init namespace which will be determinted by reading the dlm config at lowcomms_start(). Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-07-19fs: dlm: introduce con_next_wq helperAlexander Aring
This patch introduce a function to determine if something is ready to being send in the writequeue. It's not just that the writequeue is not empty additional the first entry need to have a valid length field. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-07-19fs: dlm: clear CF_APP_LIMITED on closeAlexander Aring
If send_to_sock() sets CF_APP_LIMITED limited bit and it has not been cleared by a waiting lowcomms_write_space() yet and a close_connection() apprears we should clear the CF_APP_LIMITED bit again because the connection starts from a new state again at reconnect. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-07-19fs: dlm: use sk->sk_socket instead of con->sockAlexander Aring
Instead of dereference "con->sock" we can get the socket structure over "sk->sk_socket" as well. This patch will switch to this behaviour. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-06-02fs: dlm: rename socket and app buffer definesAlexander Aring
This patch renames DEFAULT_BUFFER_SIZE to DLM_MAX_SOCKET_BUFSIZE and LOWCOMMS_MAX_TX_BUFFER_LEN to DLM_MAX_APP_BUFSIZE as they are proper names to define what's behind those values. The DLM_MAX_SOCKET_BUFSIZE defines the maximum size of buffer which can be handled on socket layer, the DLM_MAX_APP_BUFSIZE defines the maximum size of buffer which can be handled by the DLM application layer. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-06-02fs: dlm: introduce proto valuesAlexander Aring
Currently the dlm protocol values are that TCP is 0 and everything else is SCTP. This makes it difficult to introduce possible other transport layers. The only one user space tool dlm_controld, which I am aware of, handles the protocol value 1 for SCTP. We change it now to handle SCTP as 1, this will break user space API but it will fix it so we can add possible other transport layers. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-06-02fs: dlm: move dlm allow connAlexander Aring
This patch checks if possible allowing new connections is allowed before queueing the listen socket to accept new connections. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-06-02fs: dlm: use alloc_ordered_workqueueAlexander Aring
The proper way to allocate ordered workqueues is to use alloc_ordered_workqueue() function. The current way implies an ordered workqueue which is also required by dlm. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-06-02fs: dlm: fix lowcomms_start error caseAlexander Aring
This patch fixes the error path handling in lowcomms_start(). We need to cleanup some static allocated data structure and cleanup possible workqueue if these have started. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-05-25fs: dlm: don't allow half transmitted messagesAlexander Aring
This patch will clean a dirty page buffer if a reconnect occurs. If a page buffer was half transmitted we cannot start inside the middle of a dlm message if a node connects again. I observed invalid length receptions errors and was guessing that this behaviour occurs, after this patch I never saw an invalid message length again. This patch might drops more messages for dlm version 3.1 but 3.1 can't deal with half messages as well, for 3.2 it might trigger more re-transmissions but will not leave dlm in a broken state. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-05-25fs: dlm: add reliable connection if reconnectAlexander Aring
This patch introduce to make a tcp lowcomms connection reliable even if reconnects occurs. This is done by an application layer re-transmission handling and sequence numbers in dlm protocols. There are three new dlm commands: DLM_OPTS: This will encapsulate an existing dlm message (and rcom message if they don't have an own application side re-transmission handling). As optional handling additional tlv's (type length fields) can be appended. This can be for example a sequence number field. However because in DLM_OPTS the lockspace field is unused and a sequence number is a mandatory field it isn't made as a tlv and we put the sequence number inside the lockspace id. The possibility to add optional options are still there for future purposes. DLM_ACK: Just a dlm header to acknowledge the receive of a DLM_OPTS message to it's sender. DLM_FIN: This provides a 4 way handshake for connection termination inclusive support for half-closed connections. It's provided on application layer because SCTP doesn't support half-closed sockets, the shutdown() call can interrupted by e.g. TCP resets itself and a hard logic to implement it because the othercon paradigm in lowcomms. The 4-way termination handshake also solve problems to synchronize peer EOF arrival and that the cluster manager removes the peer in the node membership handling of DLM. In some cases messages can be still transmitted in this time and we need to wait for the node membership event. To provide a reliable connection the node will retransmit all unacknowledges message to it's peer on reconnect. The receiver will then filtering out the next received message and drop all messages which are duplicates. As RCOM_STATUS and RCOM_NAMES messages are the first messages which are exchanged and they have they own re-transmission handling, there exists logic that these messages must be first. If these messages arrives we store the dlm version field. This handling is on DLM 3.1 and after this patch 3.2 the same. A backwards compatibility handling has been added which seems to work on tests without tcpkill, however it's not recommended to use DLM 3.1 and 3.2 at the same time, because DLM 3.2 tries to fix long term bugs in the DLM protocol. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-05-25fs: dlm: move out some hash functionalityAlexander Aring
This patch moves out some lowcomms hash functionality into lowcomms header to provide them to other layers like midcomms as well. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-05-25fs: dlm: add functionality to re-transmit a messageAlexander Aring
This patch introduces a retransmit functionality for a lowcomms message handle. It's just allocates a new buffer and transmit it again, no special handling about prioritize it because keeping bytestream in order. To avoid another connection look some refactor was done to make a new buffer allocation with a preexisting connection pointer. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-05-25fs: dlm: make buffer handling per msgAlexander Aring
This patch makes the void pointer handle for lowcomms functionality per message and not per page allocation entry. A refcount handling for the handle was added to keep the message alive until the user doesn't need it anymore. There exists now a per message callback which will be called when allocating a new buffer. This callback will be guaranteed to be called according the order of the sending buffer, which can be used that the caller increments a sequence number for the dlm message handle. For transition process we cast the dlm_mhandle to dlm_msg and vice versa until the midcomms layer will implement a specific dlm_mhandle structure. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-05-25fs: dlm: fix connection tcp EOF handlingAlexander Aring
This patch fixes the EOF handling for TCP that if and EOF is received we will close the socket next time the writequeue runs empty. This is a half-closed socket functionality which doesn't exists in SCTP. The midcomms layer will do a half closed socket functionality on DLM side to solve this problem for the SCTP case. However there is still the last ack flying around but other reset functionality will take care of it if it got lost. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-05-25fs: dlm: cancel work sync otherconAlexander Aring
These rx tx flags arguments are for signaling close_connection() from which worker they are called. Obviously the receive worker cannot cancel itself and vice versa for swork. For the othercon the receive worker should only be used, however to avoid deadlocks we should pass the same flags as the original close_connection() was called. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-05-25fs: dlm: reconnect if socket error report occursAlexander Aring
This patch will change the reconnect handling that if an error occurs if a socket error callback is occurred. This will also handle reconnects in a non blocking connecting case which is currently missing. If error ECONNREFUSED is reported we delay the reconnect by one second. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-05-25fs: dlm: set is othercon flagAlexander Aring
There is a is othercon flag which is never used, this patch will set it and printout a warning if the othercon ever sends a dlm message which should never be the case. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>