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2015-11-24RDS: fix race condition when sending a message on unbound socketQuentin Casasnovas
Sasha's found a NULL pointer dereference in the RDS connection code when sending a message to an apparently unbound socket. The problem is caused by the code checking if the socket is bound in rds_sendmsg(), which checks the rs_bound_addr field without taking a lock on the socket. This opens a race where rs_bound_addr is temporarily set but where the transport is not in rds_bind(), leading to a NULL pointer dereference when trying to dereference 'trans' in __rds_conn_create(). Vegard wrote a reproducer for this issue, so kindly ask him to share if you're interested. I cannot reproduce the NULL pointer dereference using Vegard's reproducer with this patch, whereas I could without. Complete earlier incomplete fix to CVE-2015-6937: 74e98eb08588 ("RDS: verify the underlying transport exists before creating a connection") Cc: David S. Miller <davem@davemloft.net> Cc: stable@vger.kernel.org Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Reviewed-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-18RDS: fix rds-ping deadlock over TCP transportsantosh.shilimkar@oracle.com
Sowmini found hang with rds-ping while testing RDS over TCP. Its a corner case and doesn't happen always. The issue is not reproducible with IB transport. Its clear from below dump why we see it with RDS TCP. [<ffffffff8153b7e5>] do_tcp_setsockopt+0xb5/0x740 [<ffffffff8153bec4>] tcp_setsockopt+0x24/0x30 [<ffffffff814d57d4>] sock_common_setsockopt+0x14/0x20 [<ffffffffa096071d>] rds_tcp_xmit_prepare+0x5d/0x70 [rds_tcp] [<ffffffffa093b5f7>] rds_send_xmit+0xd7/0x740 [rds] [<ffffffffa093bda2>] rds_send_pong+0x142/0x180 [rds] [<ffffffffa0939d34>] rds_recv_incoming+0x274/0x330 [rds] [<ffffffff810815ae>] ? ttwu_queue+0x11e/0x130 [<ffffffff814dcacd>] ? skb_copy_bits+0x6d/0x2c0 [<ffffffffa0960350>] rds_tcp_data_recv+0x2f0/0x3d0 [rds_tcp] [<ffffffff8153d836>] tcp_read_sock+0x96/0x1c0 [<ffffffffa0960060>] ? rds_tcp_recv_init+0x40/0x40 [rds_tcp] [<ffffffff814d6a90>] ? sock_def_write_space+0xa0/0xa0 [<ffffffffa09604d1>] rds_tcp_data_ready+0xa1/0xf0 [rds_tcp] [<ffffffff81545249>] tcp_data_queue+0x379/0x5b0 [<ffffffffa0960cdb>] ? rds_tcp_write_space+0xbb/0x110 [rds_tcp] [<ffffffff81547fd2>] tcp_rcv_established+0x2e2/0x6e0 [<ffffffff81552602>] tcp_v4_do_rcv+0x122/0x220 [<ffffffff81553627>] tcp_v4_rcv+0x867/0x880 [<ffffffff8152e0b3>] ip_local_deliver_finish+0xa3/0x220 This happens because rds_send_xmit() chain wants to take sock_lock which is already taken by tcp_v4_rcv() on its way to rds_tcp_data_ready(). Commit db6526dcb51b ("RDS: use rds_send_xmit() state instead of RDS_LL_SEND_FULL") which was trying to opportunistically finish the send request in same thread context. But because of above recursive lock hang with RDS TCP, the send work from rds_send_pong() needs to deferred to worker to avoid lock up. Given RDS ping is more of connectivity test than performance critical path, its should be ok even for transport like IB. Reported-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Acked-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Acked-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-05RDS: IB: split send completion handling and do batch ackSantosh Shilimkar
Similar to what we did with receive CQ completion handling, we split the transmit completion handler so that it lets us implement batched work completion handling. We re-use the cq_poll routine and makes use of RDS_IB_SEND_OP to identify the send vs receive completion event handler invocation. Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
2015-10-05RDS: use rds_send_xmit() state instead of RDS_LL_SEND_FULLSantosh Shilimkar
In Transport indepedent rds_sendmsg(), we shouldn't make decisions based on RDS_LL_SEND_FULL which is used to manage the ring for RDMA based transports. We can safely issue rds_send_xmit() and the using its return value take decision on deferred work. This will also fix the scenario where at times we are seeing connections stuck with the LL_SEND_FULL bit getting set and never cleared. We kick krdsd after any time we see -ENOMEM or -EAGAIN from the ring allocation code. Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
2015-10-05RDS: defer the over_batch work to send workerSantosh Shilimkar
Current process gives up if its send work over the batch limit. The work queue will get kicked to finish off any other requests. This fixes remainder condition from commit 443be0e5affe ("RDS: make sure not to loop forever inside rds_send_xmit"). The restart condition is only for the case where we reached to over_batch code for some other reason so just retrying again before giving up. While at it, make sure we use already available 'send_batch_count' parameter instead of magic value. The batch count threshold value of 1024 came via commit 443be0e5affe ("RDS: make sure not to loop forever inside rds_send_xmit"). The idea is to process as big a batch as we can but at the same time we don't hold other waiting processes for send. Hence back-off after the send_batch_count limit (1024) to avoid soft-lock ups. Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
2015-08-25RDS: return EMSGSIZE for oversize requests before processing/queueingMukesh Kacker
rds_send_queue_rm() allows for the "current datagram" being queued to exceed SO_SNDBUF thresholds by checking bytes queued without counting in length of current datagram. (Since sk_sndbuf is set to twice requested SO_SNDBUF value as a kernel heuristic this is usually fine!) If this "current datagram" squeezing past the threshold is itself many times the size of the sk_sndbuf threshold itself then even twice the SO_SNDBUF does not save us and it gets queued but cannot be transmitted. Threads block and deadlock and device becomes unusable. The check for this datagram not exceeding SNDBUF thresholds (EMSGSIZE) is not done on this datagram as that check is only done if queueing attempt fails. (Datagrams that follow this datagram fail queueing attempts, go through the check and eventually trip EMSGSIZE error but zero length datagrams silently fail!) This fix moves the check for datagrams exceeding SNDBUF limits before any processing or queueing is attempted and returns EMSGSIZE early in the rds_sndmsg() code. This change also ensures that all datagrams get checked for exceeding SNDBUF/sk_sndbuf size limits and the large datagrams that exceed those limits do not get to rds_send_queue_rm() code for processing. Signed-off-by: Mukesh Kacker <mukesh.kacker@oracle.com> Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-25RDS: make sure rds_send_drop_to properly takes the m_rs_locksantosh.shilimkar@oracle.com
rds_send_drop_to() is used during socket tear down to find all the messages on the socket and flush them . It can race with the acking code unless it takes the m_rs_lock on each and every message. This plugs a hole where we didn't take m_rs_lock on any message that didn't have the RDS_MSG_ON_CONN set. Taking m_rs_lock avoids double frees and other memory corruptions as the ack code trusts the message m_rs pointer on a socket that had actually been freed. We must take m_rs_lock to access m_rs. Because of lock nesting and rs access, we also need to acquire rs_lock. Reviewed-by: Ajaykumar Hotchandani <ajaykumar.hotchandani@oracle.com> Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-25RDS: Mark message mapped before transmitsantosh.shilimkar@oracle.com
rds_send_xmit() marks the rds message map flag after xmit_[rdma/atomic]() which is clearly wrong. We need to maintain the ownership between transport and rds. Also take care of error path. Reviewed-by: Ajaykumar Hotchandani <ajaykumar.hotchandani@oracle.com> Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-25RDS: check for congestion updates during rds_send_xmitsantosh.shilimkar@oracle.com
Ensure we don't keep sending the data if the link is congested. Reviewed-by: Ajaykumar Hotchandani <ajaykumar.hotchandani@oracle.com> Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-07RDS-TCP: Make RDS-TCP work correctly when it is set up in a netns other than ↵Sowmini Varadhan
init_net Open the sockets calling sock_create_kern() with the correct struct net pointer, and use that struct net pointer when verifying the address passed to rds_bind(). Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
The dwmac-socfpga.c conflict was a case of a bug fix overlapping changes in net-next to handle an error pointer differently. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-08RDS: make sure not to loop forever inside rds_send_xmitSowmini Varadhan
If a determined set of concurrent senders keep the send queue full, we can loop forever inside rds_send_xmit. This fix has two parts. First we are dropping out of the while(1) loop after we've processed a large batch of messages. Second we add a generation number that gets bumped each time the xmit bit lock is acquired. If someone else has jumped in and made progress in the queue, we skip our goto restart. Original patch by Chris Mason. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-02net: Remove iocb argument from sendmsg and recvmsgYing Xue
After TIPC doesn't depend on iocb argument in its internal implementations of sendmsg() and recvmsg() hooks defined in proto structure, no any user is using iocb argument in them at all now. Then we can drop the redundant iocb argument completely from kinds of implementations of both sendmsg() and recvmsg() in the entire networking stack. Cc: Christoph Hellwig <hch@lst.de> Suggested-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-10net: introduce helper macro for_each_cmsghdrGu Zheng
Introduce helper macro for_each_cmsghdr as a wrapper of the enumerating cmsghdr from msghdr, just cleanup. Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-09put iov_iter into msghdrAl Viro
Note that the code _using_ ->msg_iter at that point will be very unhappy with anything other than unshifted iovec-backed iov_iter. We still need to convert users to proper primitives. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-24rds: switch rds_message_copy_from_user() to iov_iterAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-03net/rds: fix possible double free on sock tear downHerton R. Krzesinski
I got a report of a double free happening at RDS slab cache. One suspicion was that may be somewhere we were doing a sock_hold/sock_put on an already freed sock. Thus after providing a kernel with the following change: static inline void sock_hold(struct sock *sk) { - atomic_inc(&sk->sk_refcnt); + if (!atomic_inc_not_zero(&sk->sk_refcnt)) + WARN(1, "Trying to hold sock already gone: %p (family: %hd)\n", + sk, sk->sk_family); } The warning successfuly triggered: Trying to hold sock already gone: ffff81f6dda61280 (family: 21) WARNING: at include/net/sock.h:350 sock_hold() Call Trace: <IRQ> [<ffffffff8adac135>] :rds:rds_send_remove_from_sock+0xf0/0x21b [<ffffffff8adad35c>] :rds:rds_send_drop_acked+0xbf/0xcf [<ffffffff8addf546>] :rds_rdma:rds_ib_recv_tasklet_fn+0x256/0x2dc [<ffffffff8009899a>] tasklet_action+0x8f/0x12b [<ffffffff800125a2>] __do_softirq+0x89/0x133 [<ffffffff8005f30c>] call_softirq+0x1c/0x28 [<ffffffff8006e644>] do_softirq+0x2c/0x7d [<ffffffff8006e4d4>] do_IRQ+0xee/0xf7 [<ffffffff8005e625>] ret_from_intr+0x0/0xa <EOI> Looking at the call chain above, the only way I think this would be possible is if somewhere we already released the same socket->sock which is assigned to the rds_message at rds_send_remove_from_sock. Which seems only possible to happen after the tear down done on rds_release. rds_release properly calls rds_send_drop_to to drop the socket from any rds_message, and some proper synchronization is in place to avoid race with rds_send_drop_acked/rds_send_remove_from_sock. However, I still see a very narrow window where it may be possible we touch a sock already released: when rds_release races with rds_send_drop_acked, we check RDS_MSG_ON_CONN to avoid cleanup on the same rds_message, but in this specific case we don't clear rm->m_rs. In this case, it seems we could then go on at rds_send_drop_to and after it returns, the sock is freed by last sock_put on rds_release, with concurrently we being at rds_send_remove_from_sock; then at some point in the loop at rds_send_remove_from_sock we process an rds_message which didn't have rm->m_rs unset for a freed sock, and a possible sock_hold on an sock already gone at rds_release happens. This hopefully address the described condition above and avoids a double free on "second last" sock_put. In addition, I removed the comment about socket destruction on top of rds_send_drop_acked: we call rds_send_drop_to in rds_release and we should have things properly serialized there, thus I can't see the comment being accurate there. Signed-off-by: Herton R. Krzesinski <herton@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-18arch: Mass conversion of smp_mb__*()Peter Zijlstra
Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-18net: add build-time checks for msg->msg_name sizeSteffen Hurrle
This is a follow-up patch to f3d3342602f8bc ("net: rework recvmsg handler msg_name and msg_namelen logic"). DECLARE_SOCKADDR validates that the structure we use for writing the name information to is not larger than the buffer which is reserved for msg->msg_name (which is 128 bytes). Also use DECLARE_SOCKADDR consistently in sendmsg code paths. Signed-off-by: Steffen Hurrle <steffen@hurrle.net> Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-09RDS: fix rds-ping spinlock recursionjeff.liu
This is the revised patch for fixing rds-ping spinlock recursion according to Venkat's suggestions. RDS ping/pong over TCP feature has been broken for years(2.6.39 to 3.6.0) since we have to set TCP cork and call kernel_sendmsg() between ping/pong which both need to lock "struct sock *sk". However, this lock has already been hold before rds_tcp_data_ready() callback is triggerred. As a result, we always facing spinlock resursion which would resulting in system panic. Given that RDS ping is only used to test the connectivity and not for serious performance measurements, we can queue the pong transmit to rds_wq as a delayed response. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> CC: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com> CC: David S. Miller <davem@davemloft.net> CC: James Morris <james.l.morris@oracle.com> Signed-off-by: Jie Liu <jeff.liu@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-20Remove printk from rds_sendmsgDave Jones
no socket layer outputs a message for this error and neither should rds. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-31net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modulesPaul Gortmaker
These files are non modular, but need to export symbols using the macros now living in export.h -- call out the include so that things won't break when we remove the implicit presence of module.h from everywhere. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31net: add moduleparam.h for users of module_param/MODULE_PARM_DESCPaul Gortmaker
These files were getting access to these two via the implicit presence of module.h everywhere. They aren't modules, so they don't need the full module.h inclusion though. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-06-17net/rds: use prink_ratelimited() instead of printk_ratelimit()Manuel Zerpies
Since printk_ratelimit() shouldn't be used anymore (see comment in include/linux/printk.h), replace it with printk_ratelimited() Signed-off-by: Manuel Zerpies <manuel.f.zerpies@ww.stud.uni-erlangen.de> Signed-off-by: David S. Miller <davem@conan.davemloft.net>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2010-10-30RDS: Let rds_message_alloc_sgs() return NULLAndy Grover
Even with the previous fix, we still are reading the iovecs once to determine SGs needed, and then again later on. Preallocating space for sg lists as part of rds_message seemed like a good idea but it might be better to not do this. While working to redo that code, this patch attempts to protect against userspace rewriting the rds_iovec array between the first and second accesses. The consequences of this would be either a too-small or too-large sg list array. Too large is not an issue. This patch changes all callers of message_alloc_sgs to handle running out of preallocated sgs, and fail gracefully. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21rds: make local functions/variables staticstephen hemminger
The RDS protocol has lots of functions that should be declared static. rds_message_get/add_version_extension is removed since it defined but never used. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-08RDS: Implement masked atomic operationsAndy Grover
Add two CMSGs for masked versions of cswp and fadd. args struct modified to use a union for different atomic op type's arguments. Change IB to do masked atomic ops. Atomic op type in rds_message similarly unionized. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08rds: fix rds_send_xmit() serializationZach Brown
rds_send_xmit() was changed to hold an interrupt masking spinlock instead of a mutex so that it could be called from the IB receive tasklet path. This broke the TCP transport because its xmit method can block and masks and unmasks interrupts. This patch serializes callers to rds_send_xmit() with a simple bit instead of the current spinlock or previous mutex. This enables rds_send_xmit() to be called from any context and to call functions which block. Getting rid of the c_send_lock exposes the bare c_lock acquisitions which are changed to block interrupts. A waitqueue is added so that rds_conn_shutdown() can wait for callers to leave rds_send_xmit() before tearing down partial send state. This lets us get rid of c_senders. rds_send_xmit() is changed to check the conn state after acquiring the RDS_IN_XMIT bit to resolve races with the shutdown path. Previously both worked with the conn state and then the lock in the same order, allowing them to race and execute the paths concurrently. rds_send_reset() isn't racing with rds_send_xmit() now that rds_conn_shutdown() properly ensures that rds_send_xmit() can't start once the conn state has been changed. We can remove its previous use of the spinlock. Finally, c_send_generation is redundant. Callers can race to test the c_flags bit by simply retrying instead of racing to test the c_send_generation atomic. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08rds: remove unused rds_send_acked_before()Zach Brown
rds_send_acked_before() wasn't blocking interrupts when acquiring c_lock from user context but nothing calls it. Rather than fix its use of c_lock we just remove the function. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: introduce rds_conn_connect_if_down()Zach Brown
A few paths had the same block of code to queue a connection's connect work if it was in the right state. Let's move this in to a helper function. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08rds: Fix reference counting on the for xmit_atomic and xmit_rdmaChris Mason
This makes sure we have the proper number of references in rds_ib_xmit_atomic and rds_ib_xmit_rdma. We also consistently drop references the same way for all message types as the IOs end. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08rds: Fix RDMA message reference countingChris Mason
The RDS send_xmit code was trying to get fancy with message counting and was dropping the final reference on the RDMA messages too early. This resulted in memory corruption and oopsen. The fix here is to always add a ref as the parts of the message passes through rds_send_xmit, and always drop a ref as the parts of the message go through completion handling. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08rds: don't let RDS shutdown a connection while senders are presentChris Mason
This is the first in a long line of patches that tries to fix races between RDS connection shutdown and RDS traffic. Here we are maintaining a count of active senders to make sure the connection doesn't go away while they are using it. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08RDS: Update comments in rds_send_xmit()Andy Grover
Update comments to reflect changes in previous commit. Keeping as separate commits due to different authorship. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Use a generation counter to avoid rds_send_xmit loopChris Mason
rds_send_xmit is required to loop around after it releases the lock because someone else could done a trylock, found someone working on the list and backed off. But, once we drop our lock, it is possible that someone else does come in and make progress on the list. We should detect this and not loop around if another process is actually working on the list. This patch adds a generation counter that is bumped every time we get the lock and do some send work. If the retry notices someone else has bumped the generation counter, it does not need to loop around and continue working. Signed-off-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Get pong working againAndy Grover
Call send_xmit() directly from pong() Set pongs as op_active Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Remove send_quota from send_xmit()Andy Grover
The purpose of the send quota was really to give fairness when different connections were all using the same workq thread to send backlogged msgs -- they could only send so many before another connection could make progress. Now that each connection is pushing the backlog from its completion handler, they are all guaranteed to make progress and the quota isn't needed any longer. A thread *will* have to send all previously queued data, as well as any further msgs placed on the queue while while c_send_lock was held. In a pathological case a single process can get roped into doing this for long periods while other threads get off free. But, since it can only do this until the transport reports full, this is a bounded scenario. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Fix locking in send on m_rs_lockAndy Grover
Do not nest m_rs_lock under c_lock Disable interrupts in {rdma,atomic}_send_complete Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Call rds_send_xmit() directly from sendmsg()Andy Grover
rds_sendmsg() is calling the send worker function to send the just-queued datagrams, presumably because it wants the behavior where anything not sent will re-call the send worker. We now ensure all queued datagrams are sent by retrying from the send completion handler, so this isn't needed any more. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: rds_send_xmit() locking/irq fixesAndy Grover
rds_message_put() cannot be called with irqs off, so move it after irqs are re-enabled. Spinlocks throughout the function do not to use _irqsave because the lock of c_send_lock at top already disabled irqs. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Change send lock from a mutex to a spinlockAndy Grover
This change allows us to call rds_send_xmit() from a tasklet, which is crucial to our new operating model. * Change c_send_lock to a spinlock * Update stats fields "sem_" to "_lock" * Remove unneeded rds_conn_is_sending() About locking between shutdown and send -- send checks if the connection is up. Shutdown puts the connection into DISCONNECTING. After this, all threads entering send will exit immediately. However, a thread could be *in* send_xmit(), so shutdown acquires the c_send_lock to ensure everyone is out before proceeding with connection shutdown. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Stop supporting old cong map sending methodAndy Grover
We now ask the transport to give us a rm for the congestion map, and then we handle it normally. Previously, the transport defined a function that we would call to send a congestion map. Convert TCP and loop transports to new cong map method. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Perform unmapping ops in stagesAndy Grover
Previously, RDS would wait until the final send WR had completed and then handle cleanup. With silent ops, we do not know if an atomic, rdma, or data op will be last. This patch handles any of these cases by keeping a pointer to the last op in the message in m_last_op. When the TX completion event fires, rds dispatches to per-op-type cleanup functions, and then does whole-message cleanup, if the last op equalled m_last_op. This patch also moves towards having op-specific functions take the op struct, instead of the overall rm struct. rds_ib_connection has a pointer to keep track of a a partially- completed data send operation. This patch changes it from an rds_message pointer to the narrower rm_data_op pointer, and modifies places that use this pointer as needed. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Make sure cmsgs aren't used in improper waysAndy Grover
It hasn't cropped up in the field, but this code ensures it is impossible to issue operations that pass an rdma cookie (DEST, MAP) in the same sendmsg call that's actually initiating rdma or atomic ops. Disallowing this perverse-but-technically-allowed usage makes silent RDMA heuristics slightly easier. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Add flag for silent ops. Do atomic op before RDMAAndy Grover
Add a flag to the API so users can indicate they want silent operations. This is needed because silent ops cannot be used with USE_ONCE MRs, so we can't just assume silent. Also, change send_xmit to do atomic op before rdma op if both are present, and centralize the hairy logic to determine if we want to attempt silent, or not. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: queue failure notifications for dropped atomic opsAndy Grover
When dropping ops in the send queue, we notify the client of failed rdma ops they asked for notifications on, but not atomic ops. It should be for both. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Do not set op_active in r_m_copy_from_user().Andy Grover
Do not allocate sgs for data for 0-length datagrams Set data.op_active in rds_sendmsg() instead of rds_message_copy_from_user(). Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Rewrite rds_send_xmitAndy Grover
Simplify rds_send_xmit(). Send a congestion map (via xmit_cong_map) without decrementing send_quota. Move resetting of conn xmit variables to end of loop. Update comments. Implement a special case to turn off sending an rds header when there is an atomic op and no other data. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Rename data op members prefix from m_ to op_Andy Grover
For consistency. Signed-off-by: Andy Grover <andy.grover@oracle.com>