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path: root/drivers/connector/connector.c
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2009-02-02connector: create connector workqueue only while needed onceFrederic Weisbecker
The netlink connector uses its own workqueue to relay the datas sent from userspace to the appropriate callback. If you launch the test from Documentation/connector and change it a bit to send a high flow of data, you will see thousands of events coming to the "cqueue" workqueue by looking at the workqueue tracer. This flow of events can be sent very quickly. So, to not encumber the kevent workqueue and delay other jobs, the "cqueue" workqueue should remain. But this workqueue is pointless most of the time, it will always be created (assuming you have built it of course) although only developpers with specific needs will use it. So avoid this "most of the time useless task", this patch proposes to create this workqueue only when needed once. The first jobs to be sent to connector callbacks will be sent to kevent while the "cqueue" thread creation will be scheduled to kevent too. The following jobs will continue to be scheduled to keventd until the cqueue workqueue is created, and then the rest of the jobs will continue to perform as usual, through this dedicated workqueue. Each time I tested this patch, only the first event was sent to keventd, the rest has been sent to cqueue which have been created quickly. Also, this patch fixes some trailing whitespaces on the connector files. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-27CONNECTOR: add a proc entry to list connectorsLi Zefan
I got a problem when I wanted to check if the kernel supports process event connector, and It seems there's no way to do this check. At best I can check if the kernel supports connector or not, by looking into /proc/net/netlink, or maybe checking the return value of bind() to see if it's ENOENT. So it would be useful to add /proc/net/connector to list all supported connectors: # cat /proc/net/connector Name ID connector 4294967295:4294967295 cn_proc 1:1 w1 3:1 Changelog: - fix memory leak: s/seq_release/single_release - use spin_lock_bh instead of spin_lock_irqsave Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-02-26CONNECTOR: make cn_already_initialized staticLi Zefan
It is used in connector.c only, so make it static. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NETNS]: Consolidate kernel netlink socket destruction.Denis V. Lunev
Create a specific helper for netlink kernel socket disposal. This just let the code look better and provides a ground for proper disposal inside a namespace. Signed-off-by: Denis V. Lunev <den@openvz.org> Tested-by: Alexey Dobriyan <adobriyan@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[CONNECTOR]: clean up {,__}cn_rx_skb()Li Zefan
- __cn_rx_skb() does nothing but calls cn_call_callback(), it doesn't check skb and msg sizes as the comment suggests, but cn_rx_skb() checks those sizes. - In cn_rx_skb() Local variable 'len' is not used. 'len' is probably intended to be passed to skb_pull(), but here skb_pull() is not needed, instead skb_free() is called. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[CONNECTOR]: add a missing break in cn_netlink_send()Li Zefan
Each entry in the list has a unique id, so just break out of the loop if the matched id is found. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-04[CONNECTOR]: Return proper error code in cn_call_callback()Li Zefan
Error code should be set to EINVAL instead of ENODEV if !queue_work(). There's another call of queue_work() which may set err to EINVAL. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-30[CONNECTOR]: Fix a spurious kfree_skb() callMichal Januszewski
Remove a spurious call to kfree_skb() in the connector rx_skb handler. This fixes a regression introduced by the '[NET]: make netlink user -> kernel interface synchronious' patch (cd40b7d3983c708aabe3d3008ec64ffce56d33b0) Signed-off-by: Michal Januszewski <spock@gentoo.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NET]: make netlink user -> kernel interface synchroniousDenis V. Lunev
This patch make processing netlink user -> kernel messages synchronious. This change was inspired by the talk with Alexey Kuznetsov about current netlink messages processing. He says that he was badly wrong when introduced asynchronious user -> kernel communication. The call netlink_unicast is the only path to send message to the kernel netlink socket. But, unfortunately, it is also used to send data to the user. Before this change the user message has been attached to the socket queue and sk->sk_data_ready was called. The process has been blocked until all pending messages were processed. The bad thing is that this processing may occur in the arbitrary process context. This patch changes nlk->data_ready callback to get 1 skb and force packet processing right in the netlink_unicast. Kernel -> user path in netlink_unicast remains untouched. EINTR processing for in netlink_run_queue was changed. It forces rtnl_lock drop, but the process remains in the cycle until the message will be fully processed. So, there is no need to use this kludges now. Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NET]: Support multiple network namespaces with netlinkEric W. Biederman
Each netlink socket will live in exactly one network namespace, this includes the controlling kernel sockets. This patch updates all of the existing netlink protocols to only support the initial network namespace. Request by clients in other namespaces will get -ECONREFUSED. As they would if the kernel did not have the support for that netlink protocol compiled in. As each netlink protocol is updated to be multiple network namespace safe it can register multiple kernel sockets to acquire a presence in the rest of the network namespaces. The implementation in af_netlink is a simple filter implementation at hash table insertion and hash table look up time. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[NETLINK]: Switch cb_lock spinlock to mutex and allow to override itPatrick McHardy
Switch cb_lock to mutex and allow netlink kernel users to override it with a subsystem specific mutex for consistent locking in dump callbacks. All netlink_dump_start users have been audited not to rely on any side-effects of the previously used spinlock. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[NETLINK]: Introduce nlmsg_hdr() helperArnaldo Carvalho de Melo
For the common "(struct nlmsghdr *)skb->data" sequence, so that we reduce the number of direct accesses to skb->data and for consistency with all the other cast skb member helpers. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-03-07[CONNECTOR]: Bugfix for cn_call_callback()Philipp Reisner
When system under heavy stress and must allocate new work instead of reusing old one, new work must use correct completion callback. Patch is based on Philipp's and Lars' work. I only cleaned small stuff (and removed spaces instead of tabs). Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-18[CONNECTOR]: Replace delayed work with usual work queue.Evgeniy Polyakov
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-17[CONNECTOR]: Fix compilation breakage introduced recently.Evgeniy Polyakov
Linus has changed work queue structure and has not tested it with connector compiled in, his changes break the build. Attached patch fixes compilation error. Patch is against commit 99f5e9718185f07458ae70c2282c2153a2256c91. Thanks to Toralf Förster for pointing this out. Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-11-22WorkStruct: make allyesconfigDavid Howells
Fix up for make allyesconfig. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-06-23[PATCH] connector-exportsAndrew Morton
Put the connector exports at the functions so people can see them in context. Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-19[CONNECTOR]: Initialize subsystem earlier.Evgeniy Polyakov
Attached patch declares connector init function as subsys_init() and returns -EAGAIN in case connector is not initialized yet. Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-23[PATCH] sem2mutex: drivers: raw, connector, dcdbas, ppp_genericArjan van de Ven
Semaphore to mutex conversion. The conversion was generated via scripts, and the result was validated automatically via a script as well. Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-20[CONNECTOR]: Use netlink_has_listeners() to avoind unnecessary allocations.Evgeniy Polyakov
Return -ESRCH from cn_netlink_send() when there are not listeners, just as it could be done by netlink_broadcast(). Propagate netlink_broadcast() error back to the caller. Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-08[PATCH] gfp flags annotations - part 1Al Viro
- added typedef unsigned int __nocast gfp_t; - replaced __nocast uses for gfp flags with gfp_t - it gives exactly the same warnings as far as sparse is concerned, doesn't change generated code (from gcc point of view we replaced unsigned int with typedef) and documents what's going on far better. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-04[CONNECTOR]: fix sparse gfp nocast warningsRandy Dunlap
Fix implicit nocast warnings in connector code: drivers/connector/connector.c:102:24: warning: implicit cast to nocast type drivers/connector/connector.c:114:45: warning: implicit cast to nocast type Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-26[CONNECTOR]: async connector mode.Evgeniy Polyakov
If input message rate from userspace is too high, do not drop them, but try to deliver using work queue allocation. Failing there is some kind of congestion control. It also removes warn_on on this condition, which scares people. Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-11[NET]: Add netlink connector.Evgeniy Polyakov
Kernel connector - new userspace <-> kernel space easy to use communication module which implements easy to use bidirectional message bus using netlink as it's backend. Connector was created to eliminate complex skb handling both in send and receive message bus direction. Connector driver adds possibility to connect various agents using as one of it's backends netlink based network. One must register callback and identifier. When driver receives special netlink message with appropriate identifier, appropriate callback will be called. From the userspace point of view it's quite straightforward: socket(); bind(); send(); recv(); But if kernelspace want to use full power of such connections, driver writer must create special sockets, must know about struct sk_buff handling... Connector allows any kernelspace agents to use netlink based networking for inter-process communication in a significantly easier way: int cn_add_callback(struct cb_id *id, char *name, void (*callback) (void *)); void cn_netlink_send(struct cn_msg *msg, u32 __groups, int gfp_mask); struct cb_id { __u32 idx; __u32 val; }; idx and val are unique identifiers which must be registered in connector.h for in-kernel usage. void (*callback) (void *) - is a callback function which will be called when message with above idx.val will be received by connector core. Using connector completely hides low-level transport layer from it's users. Connector uses new netlink ability to have many groups in one socket. [ Incorporating many cleanups and fixes by myself and Andrew Morton -DaveM ] Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>