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path: root/net/smc/smc_core.c
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2020-09-03net/smc: set rx_off for SMCR explicitlyUrsula Braun
SMC tries to make use of SMCD first. If a problem shows up, it tries to switch to SMCR. If the SMCD initializing problem shows up after the SMCD connection has already been initialized, field rx_off keeps the wrong SMCD value for SMCR, which results in corrupted data at the receiver. This patch adds an explicit (re-)setting of field rx_off to zero if the connection uses SMCR. Fixes: be244f28d22f ("net/smc: add SMC-D support in data transfer") Reviewed-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-27net/smc: unique reason code for exceeded max dmb countKarsten Graul
When the maximum dmb buffer limit for an ism device is reached no more dmb buffers can be registered. When this happens the reason code is set to SMC_CLC_DECL_MEM indicating out-of-memory. This is the same reason code that is used when no memory could be allocated for the new dmb buffer. This is confusing for users when they see this error but there is more memory available. To solve this set a separate new reason code when the maximum dmb limit exceeded. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-20net/smc: fix dmb buffer shortageKarsten Graul
There is a current limit of 1920 registered dmb buffers per ISM device for smc-d. One link group can contain 255 connections, each connection is using one dmb buffer. When the connection is closed then the registered buffer is held in a queue and is reused by the next connection. When a link group is 'full' then another link group is created and uses an own buffer pool. The link groups are added to a list using list_add() which puts a new link group to the first position in the list. In the situation that many connections are opened (>1920) and a few of them stay open while others are closed quickly we end up with at least 8 link groups. For a new connection a matching link group is looked up, iterating over the list of link groups. The trailing 7 link groups all have registered dmb buffers which could be reused, while the first link group has only a few dmb buffers and then hit the 1920 limit. Because the first link group is not full (255 connection limit not reached) it is chosen and finally the connection falls back to TCP because there is no dmb buffer available in this link group. There are multiple ways to fix that: using list_add_tail() allows to scan older link groups first for free buffers which ensures that buffers are reused first. This fixes the problem for smc-r link groups as well. For smc-d there is an even better way to address this problem because smc-d does not have the 255 connections per link group limit. So fix the problem for smc-d by allowing large link groups. Fixes: c6ba7c9ba43d ("net/smc: add base infrastructure for SMC-D and ISM") Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: remove freed buffer from listKarsten Graul
Two buffers are allocated for each SMC connection. Each buffer is added to a buffer list after creation. When the second buffer allocation fails, the first buffer is freed but not deleted from the list. This might result in crashes when another connection picks up the freed buffer later and starts to work with it. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: 6511aad3f039 ("net/smc: change smc_buf_free function parameters") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: do not call dma sync for unmapped memoryKarsten Graul
The dma related ...sync_sg... functions check the link state before the dma function is actually called. But the check in smc_link_usable() allows links in ACTIVATING state which are not yet mapped to dma memory. Under high load it may happen that the sync_sg functions are called for such a link which results in an debug output like DMA-API: mlx5_core 0002:00:00.0: device driver tries to sync DMA memory it has not allocated [device address=0x0000000103370000] [size=65536 bytes] To fix that introduce a helper to check for the link state ACTIVE and use it where appropriate. And move the link state update to ACTIVATING to the end of smcr_link_init() when most initial setup is done. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: d854fcbfaeda ("net/smc: add new link state and related helpers") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: move add link processing for new device into llc layerKarsten Graul
When a new ib device is up smc will send an add link invitation to the peer if needed. This is currently done with rudimentary flow control. Under high workload these add link invitations can disturb other llc flows because they arrive unexpected. Fix this by integrating the invitations into the normal llc event flow and handle them as a flow. While at it, check for already assigned requests in the flow before the new add link request is assigned. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: 1f90a05d9ff9 ("net/smc: add smcr_port_add() and smcr_link_up() processing") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: clear link during SMC client link down processingKarsten Graul
In a link-down condition we notify the SMC server and expect that the server will finally trigger the link clear processing on the client side. This could fail when anything along this notification path goes wrong. Clear the link as part of SMC client link-down processing to prevent dangling links. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: 541afa10c126 ("net/smc: add smcr_port_err() and smcr_link_down() processing") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-08net/smc: switch smcd_dev_list spinlock to mutexUrsula Braun
The similar smc_ib_devices spinlock has been converted to a mutex. Protecting the smcd_dev_list by a mutex is possible as well. This patch converts the smcd_dev_list spinlock to a mutex. Fixes: c6ba7c9ba43d ("net/smc: add base infrastructure for SMC-D and ISM") Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-08net/smc: fix sleep bug in smc_pnet_find_roce_resource()Ursula Braun
Tests showed this BUG: [572555.252867] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935 [572555.252876] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 131031, name: smcapp [572555.252879] INFO: lockdep is turned off. [572555.252883] CPU: 1 PID: 131031 Comm: smcapp Tainted: G O 5.7.0-rc3uschi+ #356 [572555.252885] Hardware name: IBM 3906 M03 703 (LPAR) [572555.252887] Call Trace: [572555.252896] [<00000000ac364554>] show_stack+0x94/0xe8 [572555.252901] [<00000000aca1f400>] dump_stack+0xa0/0xe0 [572555.252906] [<00000000ac3c8c10>] ___might_sleep+0x260/0x280 [572555.252910] [<00000000acdc0c98>] __mutex_lock+0x48/0x940 [572555.252912] [<00000000acdc15c2>] mutex_lock_nested+0x32/0x40 [572555.252975] [<000003ff801762d0>] mlx5_lag_get_roce_netdev+0x30/0xc0 [mlx5_core] [572555.252996] [<000003ff801fb3aa>] mlx5_ib_get_netdev+0x3a/0xe0 [mlx5_ib] [572555.253007] [<000003ff80063848>] smc_pnet_find_roce_resource+0x1d8/0x310 [smc] [572555.253011] [<000003ff800602f0>] __smc_connect+0x1f0/0x3e0 [smc] [572555.253015] [<000003ff80060634>] smc_connect+0x154/0x190 [smc] [572555.253022] [<00000000acbed8d4>] __sys_connect+0x94/0xd0 [572555.253025] [<00000000acbef620>] __s390x_sys_socketcall+0x170/0x360 [572555.253028] [<00000000acdc6800>] system_call+0x298/0x2b8 [572555.253030] INFO: lockdep is turned off. Function smc_pnet_find_rdma_dev() might be called from smc_pnet_find_roce_resource(). It holds the smc_ib_devices list spinlock while calling infiniband op get_netdev(). At least for mlx5 the get_netdev operation wants mutex serialization, which conflicts with the smc_ib_devices spinlock. This patch switches the smc_ib_devices spinlock into a mutex to allow sleeping when calling get_netdev(). Fixes: a4cf0443c414 ("smc: introduce SMC as an IB-client") Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-08net/smc: separate LLC wait queues for flow and messagesKarsten Graul
There might be races in scenarios where both SMC link groups are on the same system. Prevent that by creating separate wait queues for LLC flows and messages. Switch to non-interruptable versions of wait_event() and wake_up() for the llc flow waiter to make sure the waiters get control sequentially. Fine tune the llc_flow_lock to include the assignment of the message. Write to system log when an unexpected message was dropped. And remove an extra indirection and use the existing local variable lgr in smc_llc_enqueue(). Fixes: 555da9af827d ("net/smc: add event-based llc_flow framework") Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-30net/smc: pre-fetch send buffer outside of send_lockKarsten Graul
Pre-fetch send buffer for the CDC validation message before entering the send_lock. Without that the send call might fail with -EBUSY because there are no free buffers and waiting for buffers is not possible under send_lock. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-05net/smc: log important pnetid and state change eventsKarsten Graul
Print to system log when SMC links are available or go down, link group state changes or pnetids are applied to and removed from devices. The log entries are triggered by either user configuration actions or adapter activation/deactivation events and are not expected to happen often. The entries help SMC users to keep track of the SMC link group status and to detect when actions are needed (like to add replacements for failed adapters). Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: create improved SMC-R link_uidKarsten Graul
The link_uid of an SMC-R link is exchanged between SMC peers and its value can be used for debugging purposes. Create a unique link_uid during link initialization and use it in communication with SMC-R peers. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: improve termination processingKarsten Graul
Add helper smcr_lgr_link_deactivate_all() and eliminate duplicate code. In smc_lgr_free(), clear the smc-r links before smc_lgr_free_bufs() is called so buffers are already prepared for free. The usage of the soft parameter in __smc_lgr_terminate() is no longer needed, smc_lgr_free() can be called directly. smc_lgr_terminate_sched() and smc_smcd_terminate() set lgr->freeing to indicate that the link group will be freed soon to avoid unnecessary schedules of the free worker. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: add termination reason and handle LLC protocol violationKarsten Graul
Allow to set the reason code for the link group termination, and set meaningful values before termination processing is triggered. This reason code is sent to the peer in the final delete link message. When the LLC request or response layer receives a message type that was not handled, drop a warning and terminate the link group. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: asymmetric link taggingKarsten Graul
New connections must not be assigned to asymmetric links. Add asymmetric link tagging using new link variable link_is_asym. The new helpers smcr_lgr_set_type() and smcr_lgr_set_type_asym() are called to set the state of the link group, and tag all links accordingly. smcr_lgr_conn_assign_link() respects the link tagging and will not assign new connections to links tagged as asymmetric link. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: assign link to a new connectionKarsten Graul
For new connections, assign a link from the link group, using some simple load balancing. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: send DELETE_LINK, ALL message and wait for send to completeKarsten Graul
Add smc_llc_send_message_wait() which uses smc_wr_tx_send_wait() to send an LLC message and waits for the message send to complete. smc_llc_send_link_delete_all() calls the new function to send an DELETE_LINK,ALL LLC message. The RFC states that the sender of this type of message needs to wait for the completion event of the message transmission and can terminate the link afterwards. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: handle incoming CDC validation messageKarsten Graul
Call smc_cdc_msg_validate() when a CDC message with the failover validation bit enabled was received. Validate that the sequence number sent with the message is one we already have received. If not, messages were lost and the connection is terminated using a new abort_work. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: send failover validation messageKarsten Graul
When a connection is switched to a new link then a link validation message must be sent to the peer over the new link, containing the sequence number of the last CDC message that was sent over the old link. The peer will validate if this sequence number is the same or lower then the number he received, and abort the connection if messages were lost. Add smcr_cdc_msg_send_validation() to send the message validation message and call it when a connection was switched in smc_switch_cursor(). Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: switch connections to alternate linkKarsten Graul
Add smc_switch_conns() to switch all connections from a link that is going down. Find an other link to switch the connections to, and switch each connection to the new link. smc_switch_cursor() updates the cursors of a connection to the state of the last successfully sent CDC message. When there is no link to switch to, terminate the link group. Call smc_switch_conns() when a link is going down. And with the possibility that links of connections can switch adapt CDC and TX functions to detect and handle link switches. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: enqueue local LLC messagesKarsten Graul
As SMC server, when a second link was deleted, trigger the setup of an asymmetric link. Do this by enqueueing a local ADD_LINK message which is processed by the LLC layer as if it were received from peer. Do the same when a new IB port became active and a new link could be created. smc_llc_srv_add_link_local() enqueues a local ADD_LINK message. And smc_llc_srv_delete_link_local() is used the same way to enqueue a local DELETE_LINK message. This is used when an IB port is no longer active. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: llc_del_link_work and use the LLC flow for delete linkKarsten Graul
Introduce a work that is scheduled when a new DELETE_LINK LLC request is received. The work will call either the SMC client or SMC server DELETE_LINK processing. And use the LLC flow framework to process incoming DELETE_LINK LLC messages, scheduling the llc_del_link_work for those events. With these changes smc_lgr_forget() is only called by one function and can be migrated into smc_lgr_cleanup_early(). Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: first part of add link processing as SMC clientKarsten Graul
First set of functions to process an ADD_LINK LLC request as an SMC client. Find an alternate IB device, determine the new link group type and get the index for the new link. Then ready the link, map the buffers and send an ADD_LINK LLC response. If any error occurs, send a reject LLC message and terminate the processing. Add smc_llc_alloc_alt_link() to find a free link index for a new link, depending on the new link group type. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01net/smc: remove DELETE LINK processing from smc_core.cKarsten Graul
Support for multiple links makes the former DELETE LINK processing obsolete which sent one DELETE_LINK LLC message for each single link. Remove this processing from smc_core.c. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01net/smc: take link down instead of terminating the link groupKarsten Graul
Use the introduced link down processing in all places where the link group is terminated and take down the affected link only. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01net/smc: add smcr_port_err() and smcr_link_down() processingKarsten Graul
Call smcr_port_err() when an IB event reports an inactive IB device. smcr_port_err() calls smcr_link_down() for all affected links. smcr_link_down() either triggers the local DELETE_LINK processing, or sends an DELETE_LINK LLC message to the SMC server to initiate the processing. The old handler function smc_port_terminate() is removed. Add helper smcr_link_down_cond() to take a link down conditionally, and smcr_link_down_cond_sched() to schedule the link_down processing to a work. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01net/smc: add smcr_port_add() and smcr_link_up() processingKarsten Graul
Call smcr_port_add() when an IB event reports a new active IB device. smcr_port_add() will start a work which either triggers the local ADD_LINK processing, or send an ADD_LINK LLC message to the SMC server to initiate the processing. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01net/smc: remember PNETID of IB device for later device matchingKarsten Graul
The PNETID is needed to find an alternate link for a link group. Save the PNETID of the link that is used to create the link group for later device matching. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01net/smc: mutex to protect the lgr against parallel reconfigurationsKarsten Graul
Introduce llc_conf_mutex in the link group which is used to protect the buffers and lgr states against parallel link reconfiguration. This ensures that new connections do not start to register buffers with the links of a link group when link creation or termination is running. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01net/smc: extend smc_llc_send_add_link() and smc_llc_send_delete_link()Karsten Graul
All LLC sends are done from worker context only, so remove the prep functions which were used to build the message before it was sent, and add the function content into the respective send function smc_llc_send_add_link() and smc_llc_send_delete_link(). Extend smc_llc_send_add_link() to include the qp_mtu value in the LLC message, which is needed to establish a link after the initial link was created. Extend smc_llc_send_delete_link() to contain a link_id and a reason code for the link deletion in the LLC message, which is needed when a specific link should be deleted. And add the list of existing DELETE_LINK reason codes. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01net/smc: map and register buffers for a new linkKarsten Graul
Introduce support to map and register all current buffers for a new link. smcr_buf_map_lgr() will map used buffers for a new link and smcr_buf_reg_lgr() can be called to register used buffers on the IB device of the new link. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01net/smc: unmapping of buffers to support multiple linksKarsten Graul
With the support of multiple links that are created and cleared there is a need to unmap one link from all current buffers. Add unmapping by link and by rmb. And make smcr_link_clear() available to be called from the LLC layer. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01net/smc: multiple link support for rmb buffer registrationKarsten Graul
The CONFIRM_RKEY LLC processing handles all links in one LLC message. Move the call to this processing out of smcr_link_reg_rmb() which does processing per link, into smcr_lgr_reg_rmbs() which is responsible for link group level processing. Move smcr_link_reg_rmb() into module smc_core.c. >From af_smc.c now call smcr_lgr_reg_rmbs() to register new rmbs on all available links. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30net/smc: remove obsolete link state DELETINGKarsten Graul
The connection layer in af_smc.c is now using the new LLC flow framework, which made the link state DELETING obsolete. Remove the state and the respective helpers. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30net/smc: new smc_rtoken_set functions for multiple link supportKarsten Graul
Introduce smc_rtoken_set() to set the rtoken for a new link to an existing rmb whose rtoken is given, and smc_rtoken_set2() to set an rtoken for a new link whose link_id is given. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30net/smc: multiple link support and LLC flow for smc_llc_do_delete_rkeyKarsten Graul
Adapt smc_llc_do_delete_rkey() to use the LLC flow and support multiple links when deleting the rkeys for rmb buffers at the peer. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30net/smc: add event-based llc_flow frameworkKarsten Graul
The new framework allows to start specific types of LLC control flows, protects active flows and makes it possible to wait for flows to finish before starting a new flow. This mechanism is used for the LLC control layer to model flows like 'add link' or 'delete link' which need to send/receive several LLC messages and are not allowed to get interrupted by the wrong type of messages. 'Add link' or 'Delete link' messages arriving in the middle of a flow are delayed and processed when the current flow finished. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29net/smc: move llc layer related init and clear into smc_llc.cKarsten Graul
Introduce smc_llc_lgr_init() and smc_llc_lgr_clear() to implement all llc layer specific initialization and cleanup in module smc_llc.c. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29net/smc: use mutex instead of rwlock_t to protect buffersKarsten Graul
The locks for sndbufs and rmbs are never used from atomic context. Using a mutex for these locks will allow to nest locks with other mutexes. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29net/smc: use worker to process incoming llc messagesKarsten Graul
Incoming llc messages are processed in irq tasklet context, and a worker is used to send outgoing messages. The worker is needed because getting a send buffer could result in a wait for a free buffer. To make sure all incoming llc messages are processed in a serialized way introduce an event queue and create a new queue entry for each message which is queued to this event queue. A new worker processes the event queue entries in order. And remove the use of a separate worker to send outgoing llc messages because the messages are processed in worker context already. With this event queue the serialized llc_wq work queue is obsolete, remove it. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29net/smc: simplify link deactivationKarsten Graul
Cancel the testlink worker during link clear processing and remove the extra function smc_llc_link_inactive(). Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29net/smc: add new link state and related helpersKarsten Graul
Before a link can be reused it must have been cleared. Lowest current link state is INACTIVE, which does not mean that the link is already cleared. Add a new state UNUSED that is set when the link is cleared and can be reused. Add helper smc_llc_usable_link() to find an active link in a link group, and smc_link_usable() to determine if a link is usable. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29net/smc: multi-link support for smc_rmb_rtoken_handling()Karsten Graul
Extend smc_rmb_rtoken_handling() and smc_rtoken_delete() to support multiple links. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29net/smc: convert static link ID instances to support multiple linksKarsten Graul
As a preparation for the support of multiple links remove the usage of a static link id (SMC_SINGLE_LINK) and allow dynamic link ids. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29net/smc: convert static link ID to dynamic referencesKarsten Graul
As a preparation for the support of multiple links remove the usage of a static link id (SMC_SINGLE_LINK) and allow dynamic link ids. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29net/smc: introduce link_idx for link group arrayKarsten Graul
The link_id is the index of the link in the array of the link group. When a link in the array is reused for a new link, a different unique link_id should be used, otherwise the index in the array could collide with the previous link at this array position. Use a new variable link_idx as array index, and make link_id an increasing unique id value. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29net/smc: separate function for link initializationKarsten Graul
Move the initialization of a new link into its own function, separate from smc_lgr_create, to allow more than one link per link group. Do an extra check if the IB device initialization was successful, and reset the link state if any error occurs during smcr_link_init(). And rename two existing functions to use the prefix smcr_ to indicate that they belong to the SMC-R code path. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
The mptcp conflict was overlapping additions. The SMC conflict was an additional and removal happening at the same time. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-26net/smc: fix cleanup for linkgroup setup failuresUrsula Braun
If an SMC connection to a certain peer is setup the first time, a new linkgroup is created. In case of setup failures, such a linkgroup is unusable and should disappear. As a first step the linkgroup is removed from the linkgroup list in smc_lgr_forget(). There are 2 problems: smc_listen_decline() might be called before linkgroup creation resulting in a crash due to calling smc_lgr_forget() with parameter NULL. If a setup failure occurs after linkgroup creation, the connection is never unregistered from the linkgroup, preventing linkgroup freeing. This patch introduces an enhanced smc_lgr_cleanup_early() function which * contains a linkgroup check for early smc_listen_decline() invocations * invokes smc_conn_free() to guarantee unregistering of the connection. * schedules fast linkgroup removal of the unusable linkgroup And the unused function smcd_conn_free() is removed from smc_core.h. Fixes: 3b2dec2603d5b ("net/smc: restructure client and server code in af_smc") Fixes: 2a0674fffb6bc ("net/smc: improve abnormal termination of link groups") Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>