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2010-01-22Merge branch 'master' of /home/davem/src/GIT/linux-2.6/David S. Miller
2010-01-19dccp: fix dccp rmmod when kernel configured to use slubNeil Horman
Hey all- I was tinkering with dccp recently and noticed that I BUG halted the kernel when I rmmod-ed the dccp module. The bug halt occured because the page that I passed to kfree failed the PageCompound and PageSlab test in the slub implementation of kfree. I tracked the problem down to the following set of events: 1) dccp, unlike all other uses of kmem_cache_create, allocates a string dynamically when registering a slab cache. This allocated string is freed when the cache is destroyed. 2) Normally, (1) is not an issue, but when Slub is in use, it is possible that caches are 'merged'. This process causes multiple caches of simmilar configuration to use the same cache data structure. When this happens, the new name of the cache is effectively dropped. 3) (2) results in kmem_cache_name returning an ambigous value (i.e. ccid_kmem_cache_destroy, which uses this fuction to retrieve the name pointer for freeing), is no longer guaranteed that the string it assigned is what is returned. 4) If such merge event occurs, ccid_kmem_cache_destroy frees the wrong pointer, which trips over the BUG in the slub implementation of kfree (since its likely not a slab allocation, but rather a pointer into the static string table section. So, what to do about this. At first blush this is pretty clearly a leak in the information that slub owns, and as such a slub bug. Unfortunately, theres no really good way to fix it, without exposing slub specific implementation details to the generic slab interface. Also, even if we could fix this in slub cleanly, I think the RCU free option would force us to do lots of string duplication, not only in slub, but in every slab allocator. As such, I'd like to propose this solution. Basically, I just move the storage for the kmem cache name to the ccid_operations structure. In so doing, we don't have to do the kstrdup or kfree when we allocate/free the various caches for dccp, and so we avoid the problem, by storing names with static memory, rather than heap, the way all other calls to kmem_cache_create do. I've tested this out myself here, and it solves the problem quite well. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-01-15dccp_probe: Fix module load dependencies between dccp and dccp_probeNeil Horman
This was just recently reported to me. When built as modules, the dccp_probe module has a silent dependency on the dccp module. This stems from the fact that the module_init routine of dccp_probe registers a jprobe on the dccp_sendmsg symbol. Since the symbol is only referenced as a text string (the .symbol_name field in the jprobe struct) rather than the address of the symbol itself, depmod never picks this dependency up, and so if you load the dccp_probe module without the dccp module loaded, the register_jprobe call fails with an -EINVAL, and the whole module load fails. The fix is pretty easy, we can just wrap the register_jprobe call in a try_then_request_module call, which forces the dependency to get satisfied prior to the probe registration. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-22kfifo: rename kfifo_put... into kfifo_in... and kfifo_get... into kfifo_out...Stefani Seibold
rename kfifo_put... into kfifo_in... to prevent miss use of old non in kernel-tree drivers ditto for kfifo_get... -> kfifo_out... Improve the prototypes of kfifo_in and kfifo_out to make the kerneldoc annotations more readable. Add mini "howto porting to the new API" in kfifo.h Signed-off-by: Stefani Seibold <stefani@seibold.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> Acked-by: Andi Kleen <ak@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22kfifo: cleanup namespaceStefani Seibold
change name of __kfifo_* functions to kfifo_*, because the prefix __kfifo should be reserved for internal functions only. Signed-off-by: Stefani Seibold <stefani@seibold.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> Acked-by: Andi Kleen <ak@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22kfifo: move out spinlockStefani Seibold
Move the pointer to the spinlock out of struct kfifo. Most users in tree do not actually use a spinlock, so the few exceptions now have to call kfifo_{get,put}_locked, which takes an extra argument to a spinlock. Signed-off-by: Stefani Seibold <stefani@seibold.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> Acked-by: Andi Kleen <ak@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22kfifo: move struct kfifo in placeStefani Seibold
This is a new generic kernel FIFO implementation. The current kernel fifo API is not very widely used, because it has to many constrains. Only 17 files in the current 2.6.31-rc5 used it. FIFO's are like list's a very basic thing and a kfifo API which handles the most use case would save a lot of development time and memory resources. I think this are the reasons why kfifo is not in use: - The API is to simple, important functions are missing - A fifo can be only allocated dynamically - There is a requirement of a spinlock whether you need it or not - There is no support for data records inside a fifo So I decided to extend the kfifo in a more generic way without blowing up the API to much. The new API has the following benefits: - Generic usage: For kernel internal use and/or device driver. - Provide an API for the most use case. - Slim API: The whole API provides 25 functions. - Linux style habit. - DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros - Direct copy_to_user from the fifo and copy_from_user into the fifo. - The kfifo itself is an in place member of the using data structure, this save an indirection access and does not waste the kernel allocator. - Lockless access: if only one reader and one writer is active on the fifo, which is the common use case, no additional locking is necessary. - Remove spinlock - give the user the freedom of choice what kind of locking to use if one is required. - Ability to handle records. Three type of records are supported: - Variable length records between 0-255 bytes, with a record size field of 1 bytes. - Variable length records between 0-65535 bytes, with a record size field of 2 bytes. - Fixed size records, which no record size field. - Preserve memory resource. - Performance! - Easy to use! This patch: Since most users want to have the kfifo as part of another object, reorganize the code to allow including struct kfifo in another data structure. This requires changing the kfifo_alloc and kfifo_init prototypes so that we pass an existing kfifo pointer into them. This patch changes the implementation and all existing users. [akpm@linux-foundation.org: fix warning] Signed-off-by: Stefani Seibold <stefani@seibold.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> Acked-by: Andi Kleen <ak@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-08tcp: Fix a connect() race with timewait socketsEric Dumazet
First patch changes __inet_hash_nolisten() and __inet6_hash() to get a timewait parameter to be able to unhash it from ehash at same time the new socket is inserted in hash. This makes sure timewait socket wont be found by a concurrent writer in __inet_check_established() Reported-by: kapil dakhane <kdakhane@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1815 commits) mac80211: fix reorder buffer release iwmc3200wifi: Enable wimax core through module parameter iwmc3200wifi: Add wifi-wimax coexistence mode as a module parameter iwmc3200wifi: Coex table command does not expect a response iwmc3200wifi: Update wiwi priority table iwlwifi: driver version track kernel version iwlwifi: indicate uCode type when fail dump error/event log iwl3945: remove duplicated event logging code b43: fix two warnings ipw2100: fix rebooting hang with driver loaded cfg80211: indent regulatory messages with spaces iwmc3200wifi: fix NULL pointer dereference in pmkid update mac80211: Fix TX status reporting for injected data frames ath9k: enable 2GHz band only if the device supports it airo: Fix integer overflow warning rt2x00: Fix padding bug on L2PAD devices. WE: Fix set events not propagated b43legacy: avoid PPC fault during resume b43: avoid PPC fault during resume tcp: fix a timewait refcnt race ... Fix up conflicts due to sysctl cleanups (dead sysctl_check code and CTL_UNNUMBERED removed) in kernel/sysctl_check.c net/ipv4/sysctl_net_ipv4.c net/ipv6/addrconf.c net/sctp/sysctl.c
2009-12-02TCPCT part 1a: add request_values parameter for sending SYNACKWilliam Allen Simpson
Add optional function parameters associated with sending SYNACK. These parameters are not needed after sending SYNACK, and are not used for retransmission. Avoids extending struct tcp_request_sock, and avoids allocating kernel memory. Also affects DCCP as it uses common struct request_sock_ops, but this parameter is currently reserved for future use. Signed-off-by: William.Allen.Simpson@gmail.com Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-12sysctl net: Remove unused binary sysctl codeEric W. Biederman
Now that sys_sysctl is a compatiblity wrapper around /proc/sys all sysctl strategy routines, and all ctl_name and strategy entries in the sysctl tables are unused, and can be revmoed. In addition neigh_sysctl_register has been modified to no longer take a strategy argument and it's callers have been modified not to pass one. Cc: "David Miller" <davem@davemloft.net> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: netdev@vger.kernel.org Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-05net: drop capability from protocol definitionsEric Paris
struct can_proto had a capability field which wasn't ever used. It is dropped entirely. struct inet_protosw had a capability field which can be more clearly expressed in the code by just checking if sock->type = SOCK_RAW. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-20net: Fix for dst_negative_adviceKrishna Kumar
dst_negative_advice() should check for changed dst and reset sk_tx_queue_mapping accordingly. Pass sock to the callers of dst_negative_advice. (sk_reset_txq is defined just for use by dst_negative_advice. The only way I could find to get around this is to move dst_negative_() from dst.h to dst.c, include sock.h in dst.c, etc) Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-18inet: rename some inet_sock fieldsEric Dumazet
In order to have better cache layouts of struct sock (separate zones for rx/tx paths), we need this preliminary patch. Goal is to transfert fields used at lookup time in the first read-mostly cache line (inside struct sock_common) and move sk_refcnt to a separate cache line (only written by rx path) This patch adds inet_ prefix to daddr, rcv_saddr, dport, num, saddr, sport and id fields. This allows a future patch to define these fields as macros, like sk_refcnt, without name clashes. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-13tcp: replace ehash_size by ehash_maskEric Dumazet
Storing the mask (size - 1) instead of the size allows fast path to be a bit faster. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-07IPv6: use ipv6_addr_set_v4mapped()Brian Haley
Might as well use the ipv6_addr_set_v4mapped() inline we created last year. Signed-off-by: Brian Haley <brian.haley@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-07dccp ccid-3: Remove CCID naming redundancy 2/2Gerrit Renker
This continues the previous patch, by applying the same change to CCID-3. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-07dccp ccid-2: Remove CCID naming redundancy 1/2Gerrit Renker
This removes a redundancy in the CCID half-connection (hc) naming scheme: * instead of 'hctx->tx_...', write 'hc->tx_...'; * instead of 'hcrx->rx_...', write 'hc->rx_...'; which works because the 'type' of the half-connection is encoded in the 'rx_' / 'tx_' prefixes. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-07dccp ccid-3: Overhaul CCID naming convention 2/2Gerrit Renker
This implements the new naming scheme also for CCID-3. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-07dccp ccid-2: Overhaul CCID naming convention 1/2Gerrit Renker
This patch starts a less problematic naming convention for CCID structs. The old naming convention used 'hc{tx,rx}->ccid?hc{tx,rx}->...' as recurring prefixes, which made the code * hard to write (not easy to fit into 80 characters); * hard to read (most of the space is occupied by prefixes). The new naming scheme: * struct entries for the TX socket are prefixed by 'tx_'; * and those for the RX socket are prefixed by 'rx_'. The identifiers then remain distinguishable when grep-ing through the tree: (a) RX/TX sockets are distinguished by the naming scheme, (b) individual CCIDs are distinguished by filename (ccid{2,3,4}.{c,h}). This first patch implements the scheme for CCID-2. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-30net: Make setsockopt() optlen be unsigned.David S. Miller
This provides safety against negative optlen at the type level instead of depending upon (sometimes non-trivial) checks against this sprinkled all over the the place, in each and every implementation. Based upon work done by Arjan van de Ven and feedback from Linus Torvalds. Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-22mm: replace various uses of num_physpages by totalram_pagesJan Beulich
Sizing of memory allocations shouldn't depend on the number of physical pages found in a system, as that generally includes (perhaps a huge amount of) non-RAM pages. The amount of what actually is usable as storage should instead be used as a basis here. Some of the calculations (i.e. those not intending to use high memory) should likely even use (totalram_pages - totalhigh_pages). Signed-off-by: Jan Beulich <jbeulich@novell.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Dave Airlie <airlied@linux.ie> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: "David S. Miller" <davem@davemloft.net> Cc: Patrick McHardy <kaber@trash.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-14net: constify remaining proto_opsAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-14net: constify struct inet6_protocolAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-14net: constify struct net_protocolAlexey Dobriyan
Remove long removed "inet_protocol_base" declaration. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-14net-next-2.6 [PATCH 1/1] dccp: ccids whitespace-cleanup / CodingStyleGerrit Renker
No code change, cosmetical changes only: * whitespace cleanup via scripts/cleanfile, * remove self-references to filename at top of files, * fix coding style (extraneous brackets), * fix documentation style (kernel-doc-nano-HOWTO). Thanks are due to Ivo Augusto Calado who raised these issues by submitting good-quality patches. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-02inet: inet_connection_sock_af_ops constStephen Hemminger
The function block inet_connect_sock_af_ops contains no data make it constant. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-12Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: arch/microblaze/include/asm/socket.h
2009-08-09Merge branch 'master' of /home/davem/src/GIT/linux-2.6/David S. Miller
2009-08-05net: mark read-only arrays as constJan Engelhardt
String literals are constant, and usually, we can also tag the array of pointers const too, moving it to the .rodata section. Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-05dccp: missing destroy of percpu counter variable while unload moduleWei Yongjun
percpu counter dccp_orphan_count is init in dccp_init() by percpu_counter_init() while dccp module is loaded, but the destroy of it is missing while dccp module is unloaded. We can get the kernel WARNING about this. Reproduct by the following commands: $ modprobe dccp $ rmmod dccp $ modprobe dccp WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c() Hardware name: VMware Virtual Platform list_add corruption. next->prev should be prev (c080c0c4), but was (null). (next =ca7188cc). Modules linked in: dccp(+) nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc Pid: 1956, comm: modprobe Not tainted 2.6.31-rc5 #55 Call Trace: [<c042f8fa>] warn_slowpath_common+0x6a/0x81 [<c053a6cb>] ? __list_add+0x27/0x5c [<c042f94f>] warn_slowpath_fmt+0x29/0x2c [<c053a6cb>] __list_add+0x27/0x5c [<c053c9b3>] __percpu_counter_init+0x4d/0x5d [<ca9c90c7>] dccp_init+0x19/0x2ed [dccp] [<c0401141>] do_one_initcall+0x4f/0x111 [<ca9c90ae>] ? dccp_init+0x0/0x2ed [dccp] [<c06971b5>] ? notifier_call_chain+0x26/0x48 [<c0444943>] ? __blocking_notifier_call_chain+0x45/0x51 [<c04516f7>] sys_init_module+0xac/0x1bd [<c04028e4>] sysenter_do_call+0x12/0x22 Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-29net-dccp: suppress warning about large allocations from DCCPMel Gorman
The DCCP protocol tries to allocate some large hash tables during initialisation using the largest size possible. This can be larger than what the page allocator can provide so it prints a warning. However, the caller is able to handle the situation so this patch suppresses the warning. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-09net: adding memory barrier to the poll and receive callbacksJiri Olsa
Adding memory barrier after the poll_wait function, paired with receive callbacks. Adding fuctions sock_poll_wait and sk_has_sleeper to wrap the memory barrier. Without the memory barrier, following race can happen. The race fires, when following code paths meet, and the tp->rcv_nxt and __add_wait_queue updates stay in CPU caches. CPU1 CPU2 sys_select receive packet ... ... __add_wait_queue update tp->rcv_nxt ... ... tp->rcv_nxt check sock_def_readable ... { schedule ... if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) wake_up_interruptible(sk->sk_sleep) ... } If there was no cache the code would work ok, since the wait_queue and rcv_nxt are opposit to each other. Meaning that once tp->rcv_nxt is updated by CPU2, the CPU1 either already passed the tp->rcv_nxt check and sleeps, or will get the new value for tp->rcv_nxt and will return with new data mask. In both cases the process (CPU1) is being added to the wait queue, so the waitqueue_active (CPU2) call cannot miss and will wake up CPU1. The bad case is when the __add_wait_queue changes done by CPU1 stay in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 will then endup calling schedule and sleep forever if there are no more data on the socket. Calls to poll_wait in following modules were ommited: net/bluetooth/af_bluetooth.c net/irda/af_irda.c net/irda/irnet/irnet_ppp.c net/mac80211/rc80211_pid_debugfs.c net/phonet/socket.c net/rds/af_rds.c net/rfkill/core.c net/sunrpc/cache.c net/sunrpc/rpc_pipe.c net/tipc/socket.c Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-23ipv6: Use correct data types for ICMPv6 type and codeBrian Haley
Change all the code that deals directly with ICMPv6 type and code values to use u8 instead of a signed int as that's the actual data type. Signed-off-by: Brian Haley <brian.haley@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-03net: skb->dst accessorsEric Dumazet
Define three accessors to get/set dst attached to a skb struct dst_entry *skb_dst(const struct sk_buff *skb) void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) void skb_dst_drop(struct sk_buff *skb) This one should replace occurrences of : dst_release(skb->dst) skb->dst = NULL; Delete skb->dst field Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-03net: skb->rtable accessorEric Dumazet
Define skb_rtable(const struct sk_buff *skb) accessor to get rtable from skb Delete skb->rtable field Setting rtable is not allowed, just set dst instead as rtable is an alias. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02dccp: Do not let initial option overhead shrink the MPSGerrit Renker
This fixes a problem caused by the overlap of the connection-setup and established-state phases of DCCP connections. During connection setup, the client retransmits Confirm Feature-Negotiation options until a response from the server signals that it can move from the half-established PARTOPEN into the OPEN state, whereupon the connection is fully established on both ends (RFC 4340, 8.1.5). However, since the client may already send data while it is in the PARTOPEN state, consequences arise for the Maximum Packet Size: the problem is that the initial option overhead is much higher than for the subsequent established phase, as it involves potentially many variable-length list-type options (server-priority options, RFC 4340, 6.4). Applying the standard MPS is insufficient here: especially with larger payloads this can lead to annoying, counter-intuitive EMSGSIZE errors. On the other hand, reducing the MPS available for the established phase by the added initial overhead is highly wasteful and inefficient. The solution chosen therefore is a two-phase strategy: If the payload length of the DataAck in PARTOPEN is too large, an Ack is sent to carry the options, and the feature-negotiation list is then flushed. This means that the server gets two Acks for one Response. If both Acks get lost, it is probably better to restart the connection anyway and devising yet another special-case does not seem worth the extra complexity. The result is a higher utilisation of the available packet space for the data transmission phase (established state) of a connection. The patch (over-)estimates the initial overhead to be 32*4 bytes -- commonly seen values were around 90 bytes for initial feature-negotiation options. It uses sizeof(u32) to mean "aligned units of 4 bytes". For consistency, another use of 4-byte alignment is adapted. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02dccp: Minimise header option overhead in setting the MPSGerrit Renker
This patch resolves a long-standing FIXME to dynamically update the Maximum Packet Size depending on actual options usage. It uses the flags set by the feature-negotiation infrastructure to compute the required header option size. Most options are fixed-size, a notable exception are Ack Vectors (required currently only by CCID-2). These can have any length between 3 and 1020 bytes. As a result of testing, 16 bytes (2 bytes for type/length plus 14 Ack Vector cells) have been found to be sufficient for loss-free situations. There are currently no CCID-specific header options which may appear on data packets, thus it is not necessary to define a corresponding CCID field as suggested in the old comment. Further changes: ---------------- Adjusted the type of 'cur_mps' to match the unsigned return type of the function. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-21dccp: Debugging functions for feature negotiationGerrit Renker
Since all feature-negotiation processing now takes place in feat.c, functions for producing verbose debugging output are concentrated there. New functions to print out values, entry records, and options are provided, and also a macro is defined to not always have the function name in the output line. Thanks a lot to Wei Yongjun and Giuseppe Galeota for help and discussion with an earlier revision of this patch. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-21dccp: Initialisation and type-checking of feature sysctlsGerrit Renker
This patch takes care of initialising and type-checking sysctls related to feature negotiation. Type checking is important since some of the sysctls now directly impact the feature-negotiation process. The sysctls are initialised with the known default values for each feature. For the type-checking the value constraints from RFC 4340 are used: * Sequence Window uses the specified Wmin=32, the maximum is ulong (4 bytes), tested and confirmed that it works up to 4294967295 - for Gbps speed; * Ack Ratio is between 0 .. 0xffff (2-byte unsigned integer); * CCIDs are between 0 .. 255; * request_retries, retries1, retries2 also between 0..255 for good measure; * tx_qlen is checked to be non-negative; * sync_ratelimit remains as before. Notes: ------ 1. Die s@sysctl_dccp_feat@sysctl_dccp@g since the sysctls are now in feat.c. 2. As pointed out by Arnaldo, the pattern of type-checking repeats itself in other places, sometimes with exactly the same kind of definitions (e.g. "static int zero;"). It may be a good idea (kernel janitors?) to consolidate type checking. For the sake of keeping the changeset small and in order not to affect other subsystems, I have not strived to generalise here. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-21dccp: Implement both feature-local and feature-remote Sequence Window featureGerrit Renker
This adds full support for local/remote Sequence Window feature, from which the * sequence-number-validity (W) and * acknowledgment-number-validity (W') windows derive as specified in RFC 4340, 7.5.3. Specifically, the following is contained in this patch: * integrated new socket fields into dccp_sk; * updated the update_gsr/gss routines with regard to these fields; * updated handler code: the Sequence Window feature is located at the TX side, so the local feature is meant if the handler-rx flag is false; * the initialisation of `rcv_wnd' in reqsk is removed, since - rcv_wnd is not used by the code anywhere; - sequence number checks are not done in the LISTEN state (cf. 7.5.3); - dccp_check_req checks the Ack number validity more rigorously; * the `struct dccp_minisock' became empty and is now removed. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-21dccp: Initialisation framework for feature negotiationGerrit Renker
This initialises feature negotiation from two tables, which are in turn are initialised from sysctls. As a novel feature, specifics of the implementation (e.g. that short seqnos and ECN are not yet available) are advertised for robustness. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-11dccp ccid-3: Fix RFC referenceGerrit Renker
Thanks to Wei and Arnaldo for pointing out the correct new reference for CCID-3. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-11net: fix section mismatch warnings in dccp/ccids/lib/tfrc.cLeonardo Potenza
Removed the __exit annotation of tfrc_lib_exit(), in order to suppress the following section mismatch messages: WARNING: net/dccp/dccp.o(.text+0xd9): Section mismatch in reference from the function ccid_cleanup_builtins() to the function .exit.text:tfrc_lib_exit() The function ccid_cleanup_builtins() references a function in an exit section. Often the function tfrc_lib_exit() has valid usage outside the exit section and the fix is to remove the __exit annotation of tfrc_lib_exit. WARNING: net/dccp/dccp.o(.init.text+0x48): Section mismatch in reference from the function ccid_initialize_builtins() to the function .exit.text:tfrc_lib_exit() The function __init ccid_initialize_builtins() references a function __exit tfrc_lib_exit(). This is often seen when error handling in the init function uses functionality in the exit path. The fix is often to remove the __exit annotation of tfrc_lib_exit() so it may be used outside an exit section. Signed-off-by: Leonardo Potenza <lpotenza@inwind.it> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-04dccp: Integrate the TFRC library with DCCPGerrit Renker
This patch integrates the TFRC library, which is a dependency of CCID-3 (and CCID-4), with the new use of CCIDs in the DCCP module. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-04dccp: Clean up ccid.c after integration of CCID pluginsGerrit Renker
This patch cleans up after integrating the CCID modules and, in addition, * moves the if/else cases from ccid_delete() into ccid_hc_{tx,rx}_delete(); * removes the 'gfp' argument to ccid_new() - since it is always gfp_any(). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-04dccp: Lockless integration of CCID congestion-control pluginsGerrit Renker
Based on Arnaldo's earlier patch, this patch integrates the standardised CCID congestion control plugins (CCID-2 and CCID-3) of DCCP with dccp.ko: * enables a faster connection path by eliminating the need to always go through the CCID registration lock; * updates the implementation to use only a single array whose size equals the number of configured CCIDs instead of the maximum (256); * since the CCIDs are now fixed array elements, synchronization is no longer needed, simplifying use and implementation. CCID-2 is suggested as minimum for a basic DCCP implementation (RFC 4340, 10); CCID-3 is a standards-track CCID supported by RFC 4342 and RFC 5348. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-29net: Fix percpu counters deadlockHerbert Xu
When we converted the protocol atomic counters such as the orphan count and the total socket count deadlocks were introduced due to the mismatch in BH status of the spots that used the percpu counter operations. Based on the diagnosis and patch by Peter Zijlstra, this patch fixes these issues by disabling BH where we may be in process context. Reported-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-17dccp_diag: LISTEN sockets don't have CCIDsArnaldo Carvalho de Melo
And thus when we try to use 'ss -danemi' on these sockets that have no ccid blocks (data collected using systemtap after I fixed the problem): dccp_diag_get_info sk=0xffff8801220a3100, dp->dccps_hc_rx_ccid=0x0000000000000000, dp->dccps_hc_tx_ccid=0x0000000000000000 We get an OOPS: mica.ghostprotocols.net login: BUG: unable to handle kernel NULL pointer dereferenc0 IP: [<ffffffffa0136082>] dccp_diag_get_info+0x82/0xc0 [dccp_diag] PGD 12106f067 PUD 122488067 PMD 0 Oops: 0000 [#1] PREEMPT Fix is trivial, and 'ss -d' is working again: [root@mica ~]# ss -danemi State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 0 *:5001 *:* ino:7288 sk:220a3100ffff8801 mem:(r0,w0,f0,t0) cwnd:0 ssthresh:0 [root@mica ~]# Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-08dccp ccid-2: Phase out the use of boolean Ack Vector sysctlGerrit Renker
This removes the use of the sysctl and the minisock variable for the Send Ack Vector feature, as it now is handled fully dynamically via feature negotiation (i.e. when CCID-2 is enabled, Ack Vectors are automatically enabled as per RFC 4341, 4.). Using a sysctl in parallel to this implementation would open the door to crashes, since much of the code relies on tests of the boolean minisock / sysctl variable. Thus, this patch replaces all tests of type if (dccp_msk(sk)->dccpms_send_ack_vector) /* ... */ with if (dp->dccps_hc_rx_ackvec != NULL) /* ... */ The dccps_hc_rx_ackvec is allocated by the dccp_hdlr_ackvec() when feature negotiation concluded that Ack Vectors are to be used on the half-connection. Otherwise, it is NULL (due to dccp_init_sock/dccp_create_openreq_child), so that the test is a valid one. The activation handler for Ack Vectors is called as soon as the feature negotiation has concluded at the * server when the Ack marking the transition RESPOND => OPEN arrives; * client after it has sent its ACK, marking the transition REQUEST => PARTOPEN. Adding the sequence number of the Response packet to the Ack Vector has been removed, since (a) connection establishment implies that the Response has been received; (b) the CCIDs only look at packets received in the (PART)OPEN state, i.e. this entry will always be ignored; (c) it can not be used for anything useful - to detect loss for instance, only packets received after the loss can serve as pseudo-dupacks. There was a FIXME to change the error code when dccp_ackvec_add() fails. I removed this after finding out that: * the check whether ackno < ISN is already made earlier, * this Response is likely the 1st packet with an Ackno that the client gets, * so when dccp_ackvec_add() fails, the reason is likely not a packet error. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>