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2010-09-09tunnels: missing rcu_assign_pointer()Eric Dumazet2-2/+2
xfrm4_tunnel_register() & xfrm6_tunnel_register() should use rcu_assign_pointer() to make sure previous writes (to handler->next) are committed to memory before chain insertion. deregister functions dont need a particular barrier. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-09net/core: add lock context change annotations in net/core/sock.cNamhyung Kim1-0/+4
__lock_sock() and __release_sock() releases and regrabs lock but were missing proper annotations. Add it. This removes following warning from sparse. (Currently __lock_sock() does not emit any warning about it but I think it is better to add also.) net/core/sock.c:1580:17: warning: context imbalance in '__release_sock' - unexpected unlock Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-09net/core: remove address space warnings on verify_iovec()Namhyung Kim1-2/+4
move_addr_to_kernel() and copy_from_user() requires their argument as __user pointer but were missing proper markups. Add it. This removes following warnings from sparse. net/core/iovec.c:44:52: warning: incorrect type in argument 1 (different address spaces) net/core/iovec.c:44:52: expected void [noderef] <asn:1>*uaddr net/core/iovec.c:44:52: got void *msg_name net/core/iovec.c:55:34: warning: incorrect type in argument 2 (different address spaces) net/core/iovec.c:55:34: expected void const [noderef] <asn:1>*from net/core/iovec.c:55:34: got struct iovec *msg_iov Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-09Merge branch 'for-davem' of git://oss.oracle.com/git/agrover/linux-2.6David S. Miller42-1613/+2614
2010-09-08atlx: make strings constStephen Hemminger1-3/+3
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Acked-by: Chris Snook <chris.snook@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-08net: inet_add_protocol() can use cmpxchg()Eric Dumazet2-54/+9
Use cmpxchg() to get rid of spinlocks in inet_add_protocol() and friends. inet_protos[] & inet6_protos[] are moved to read_mostly section Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-08cxacru: ignore cx82310_eth devicesOndrej Zary1-1/+17
Ignore ADSL routers, which can have the same vendor and product IDs as ADSL modems but should be handled by the cx82310_eth driver. This intentionally ignores device IDs that aren't currently handled by cx82310_eth. There may be other device IDs that perhaps shouldn't be claimed by cxacru. Signed-off-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-08RDS: Remove dead struct from rds.hAndy Grover1-8/+0
flows are an obsolete date type. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: rds.h: Replace u_int[size]_t with uint[size]_tAndy Grover1-29/+29
Replace e.g. u_int32_t types with the more common uint32_t. Reported-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Add rds.h to exported headers listAndy Grover2-6/+7
Also, a number of changes were made based on the assumption that rds.h wasn't exported, so roll these back. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Implement masked atomic operationsAndy Grover5-13/+64
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/IB: print string constants in more placesZach Brown7-21/+97
This prints the constant identifier for work completion status and rdma cm event types, like we already do for IB event types. A core string array helper is added that each string type uses. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: cancel connection work structs as we shut downZach Brown1-0/+4
Nothing was canceling the send and receive work that might have been queued as a conn was being destroyed. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: don't call rds_conn_shutdown() from rds_conn_destroy()Zach Brown1-2/+7
rds_conn_shutdown() can return before the connection is shut down when it encounters an existing state that it doesn't understand. This lets rds_conn_destroy() then start tearing down the conn from under paths that are still using it. It's more reliable the shutdown work and wait for krdsd to complete the shutdown callback. This stopped some hangs I was seeing where krdsd was trying to shut down a freed conn. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: have sockets get transport module referencesZach Brown4-6/+21
Right now there's nothing to stop the various paths that use rs->rs_transport from racing with rmmod and executing freed transport code. The simple fix is to have binding to a transport also hold a reference to the transport's module, removing this class of races. We already had an unused t_owner field which was set for the modular transports and which wasn't set for the built-in loop transport. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: remove old rs_transport commentZach Brown1-6/+0
rs_transport is now also used by the rdma paths once the socket is bound. We don't need this stale comment to tell us what cscope can. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: lock rds_conn_count decrement in rds_conn_destroy()Zach Brown1-0/+3
rds_conn_destroy() can race with all other modifications of the rds_conn_count but it was modifying the count without locking. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS/IB: protect the list of IB devicesZach Brown3-10/+26
The RDS IB device list wasn't protected by any locking. Traversal in both the get_mr and FMR flushing paths could race with additon and removal. List manipulation is done with RCU primatives and is protected by the write side of a rwsem. The list traversal in the get_mr fast path is protected by a rcu read critical section. The FMR list traversal is more problematic because it can block while traversing the list. We protect this with the read side of the rwsem. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS/IB: print IB event strings as well as their numberZach Brown1-4/+39
It's nice to not have to go digging in the code to see which event occurred. It's easy to throw together a quick array that maps the ib event enums to their strings. I didn't see anything in the stack that does this translation for us, but I also didn't look very hard. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: flush fmrs before allocating new onesChris Mason1-2/+5
Flushing FMRs is somewhat expensive, and is currently kicked off when the interrupt handler notices that we are getting low. The result of this is that FMR flushing only happens from the interrupt cpus. This spreads the load more effectively by triggering flushes just before we allocate a new FMR. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08RDS: properly use sg_init_tableChris Mason1-0/+1
This is only needed to keep debugging code from bugging. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08RDS/IB: track signaled sendsZach Brown3-8/+54
We're seeing bugs today where IB connection shutdown clears the send ring while the tasklet is processing completed sends. Implementation details cause this to dereference a null pointer. Shutdown needs to wait for send completion to stop before tearing down the connection. We can't simply wait for the ring to empty because it may contain unsignaled sends that will never be processed. This patch tracks the number of signaled sends that we've posted and waits for them to complete. It also makes sure that the tasklet has finished executing. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: remove __init and __exit annotationZach Brown20-35/+35
The trivial amount of memory saved isn't worth the cost of dealing with section mismatches. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS/IB: Use SLAB_HWCACHE_ALIGN flag for kmem_cache_create()Andy Grover1-2/+2
We are *definitely* counting cycles as closely as DaveM, so ensure hwcache alignment for our recv ring control structs. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS/IB: always process recv completionsZach Brown1-8/+12
The recv refill path was leaking fragments because the recv event handler had marked a ring element as free without freeing its frag. This was happening because it wasn't processing receives when the conn wasn't marked up or connecting, as can be the case if it races with rmmod. Two observations support always processing receives in the callback. First, buildup should only post receives, thus triggering recv event handler calls, once it has built up all the state to handle them. Teardown should destroy the CQ and drain the ring before tearing down the state needed to process recvs. Both appear to be true today. Second, this test was fundamentally racy. There is nothing to stop rmmod and connection destruction from swooping in the moment after the conn state was sampled but before real receive procesing starts. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: return to a single-threaded krdsdZach Brown1-1/+1
We were seeing very nasty bugs due to fundamental assumption the current code makes about concurrent work struct processing. The code simpy isn't able to handle concurrent connection shutdown work function execution today, for example, which is very much possible once a multi-threaded krdsd was introduced. The problem compounds as additional work structs are added to the mix. krdsd is no longer perforance critical now that send and receive posting and FMR flushing are done elsewhere, so the safest fix is to move back to the single threaded krdsd that the current code was built around. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS/IB: create a work queue for FMR flushingZach Brown3-3/+33
This patch moves the FMR flushing work in to its own mult-threaded work queue. This is to maintain performance in preparation for returning the main krdsd work queue back to a single threaded work queue to avoid deep-rooted concurrency bugs. This is also good because it further separates FMRs, which might be removed some day, from the rest of the code base. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS/IB: destroy connections on rmmodZach Brown3-15/+6
IB connections were not being destroyed during rmmod. First, recently IB device removal callback was changed to disconnect connections that used the removing device rather than destroying them. So connections with devices during rmmod were not being destroyed. Second, rds_ib_destroy_nodev_conns() was being called before connections are disassociated with devices. It would almost never find connections in the nodev list. We first get rid of rds_ib_destroy_conns(), which is no longer called, and refactor the existing caller into the main body of the function and get rid of the list and lock wrappers. Then we call rds_ib_destroy_nodev_conns() *after* ib_unregister_client() has removed the IB device from all the conns and put the conns on the nodev list. The result is that IB connections are destroyed by rmmod. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS/IB: wait for IB dev freeing work to finish during rmmodZach Brown1-2/+9
The RDS IB client removal callback can queue work to drop the final reference to an IB device. We have to make sure that this function has returned before we complete rmmod or the work threads can try to execute freed code. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS/IB: Make ib_recv_refill return voidAndy Grover2-6/+2
Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Remove unused XLIST_PTR_TAIL and xlist_protect()Andy Grover1-42/+12
Not used. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: whitespaceAndy Grover2-2/+0
2010-09-08RDS: use delayed work for the FMR flushesChris Mason1-6/+6
Using a delayed work queue helps us make sure a healthy number of FMRs have queued up over the limit. It makes for a large improvement in RDMA iops. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08rds: more FMRs are fasterChris Mason1-1/+1
When we add more FMRs, we flush them less often and so we go faster. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08rds: recycle FMRs through lockless listsChris Mason2-42/+282
FRM allocation and recycling is performance critical and fairly lock intensive. The current code has a per connection lock that all processes bang on and it becomes a major bottleneck on large systems. This changes things to use a number of cmpxchg based lists instead, allowing us to go through the whole FMR lifecycle without locking inside RDS. Zach Brown pointed out that our usage of cmpxchg for xlist removal is racey if someone manages to remove and add back an FMR struct into the list while another CPU can see the FMR's address at the head of the list. The second CPU might assume the list hasn't changed when in fact any number of operations might have happened in between the deletion and reinsertion. This commit maintains a per cpu count of CPUs that are currently in xlist removal, and establishes a grace period to make sure that nobody can see an entry we have just removed from the list. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08rds: fix rds_send_xmit() serializationZach Brown5-58/+52
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: block ints when acquiring c_lock in rds_conn_message_info()Zach Brown1-2/+3
conn->c_lock is acquired in interrupt context. rds_conn_message_info() is called from user context and was acquiring c_lock without blocking interrupts, leading to possible deadlocks. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08rds: remove unused rds_send_acked_before()Zach Brown2-30/+0
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: use friendly gfp masks for prefillChris Mason1-9/+18
When prefilling the rds frags, we end up doing a lot of allocations. We're not in atomic context here, and so there's no reason to dip into atomic reserves. This changes the prefills to use masks that allow waiting. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08RDS/IB: Add caching of frags and incsChris Mason3-52/+297
This patch is based heavily on an initial patch by Chris Mason. Instead of freeing slab memory and pages, it keeps them, and funnels them back to be reused. The lock minimization strategy uses xchg and cmpxchg atomic ops for manipulation of pointers to list heads. We anchor the lists with a pointer to a list_head struct instead of a static list_head struct. We just have to carefully use the existing primitives with the difference between a pointer and a static head struct. For example, 'list_empty()' means that our anchor pointer points to a list with a single item instead of meaning that our static head element doesn't point to any list items. Original patch by Chris, with significant mods and fixes by Andy and Zach. Signed-off-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS/IB: Remove ib_recv_unmap_page()Andy Grover1-20/+2
All it does is call unmap_sg(), so just call that directly. The comment above unmap_page also may be incorrect, so we shouldn't hold on to it, either. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Assume recv->r_frag is always NULL in refill_one()Andy Grover1-13/+16
refill_one() should never be called on a recv struct that doesn't need a new r_frag allocated. Add a WARN and remove conditional around r_frag alloc code. Also, add a comment to explain why r_ibinc may or may not need refilling. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Use page_remainder_alloc() for recv bufsAndy Grover3-73/+29
Instead of splitting up a page into RDS_FRAG_SIZE chunks ourselves, ask rds_page_remainder_alloc() to do it. While it is possible PAGE_SIZE > FRAG_SIZE, on x86en it isn't, so having duplicate "carve up a page into buffers" code seems excessive. The other modification this spawns is the use of a single struct scatterlist in rds_page_frag instead of a bare page ptr. This causes verbosity to increase in some places, and decrease in others. Finally, I decided to unify the lifetimes and alloc/free of rds_page_frag and its page. This is a nice simplification in itself, but will be extra-nice once we come to adding cmason's recycling patch. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS/IB: disconnect when IB devices are removedZach Brown1-1/+24
Currently IB device removal destroys connections which are associated with the device. This prevents connections from being re-established when replacement devices are added. Instead we'll queue shutdown work on the connections as their devices are removed. When we see that devices are added we triger connection attempts on all connections that don't currently have a device. The result is that RDS sockets can resume device-independent work (bcopy, not RDMA) across IB device removal and restoration. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: introduce rds_conn_connect_if_down()Zach Brown3-14/+15
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/IB: add refcount tracking to struct rds_ib_deviceZach Brown4-55/+125
The RDS IB client .remove callback used to free the rds_ibdev for the given device unconditionally. This could race other users of the struct. This patch adds refcounting so that we only free the rds_ibdev once all of its users are done. Many rds_ibdev users are tied to connections. We give the connection a reference and change these users to reference the device in the connection instead of looking it up in the IB client data. The only user of the IB client data remaining is the first lookup of the device as connections are built up. Incrementing the reference count of a device found in the IB client data could race with final freeing so we use an RCU grace period to make sure that freeing won't happen until those lookups are done. MRs need the rds_ibdev to get at the pool that they're freed in to. They exist outside a connection and many MRs can reference different devices from one socket, so it was natural to have each MR hold a reference. MR refs can be dropped from interrupt handlers and final device teardown can block so we push it off to a work struct. Pool teardown had to be fixed to cancel its pending work instead of deadlocking waiting for all queued work, including itself, to finish. MRs get their reference from the global device list, which gets a reference. It is left unprotected by locks and remains racy. A simple global lock would be a significant bottleneck. More scalable (complicated) locking should be done carefully in a later patch. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS/IB: get the xmit max_sge from the RDS IB device on the connectionZach Brown1-7/+5
rds_ib_xmit_rdma() was calling ib_get_client_data() to get at the rds_ibdevice just to get the max_sge for the transmit. This patch instead has it get it directly off the rds_ibdev which is stored on the connection. The current code won't free the rds_ibdev until all the IB connections that use it are freed. So it's safe to reference the rds_ibdev this way. In the future it also makes it easier to support proper reference counting of the rds_ibdev struct. As an additional bonus, this gets rid of the performance hit of calling in to the IB stack to look up the rds_ibdev. The current implementation in the IB stack acquires an interrupt blocking spinlock to protect the registration of client callback data. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS/IB: rds_ib_cm_handle_connect() forgot to unlock c_cm_lockZach Brown1-9/+6
rds_ib_cm_handle_connect() could return without unlocking the c_conn_lock if rds_setup_qp() failed. Rather than adding another imbalanced mutex_unlock() to this error path we only unlock the mutex once as we exit the function, reducing the likelyhood of making this same mistake in the future. We remove the previous mulitple return sites, leaving one unambigious return path. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08rds: Fix reference counting on the for xmit_atomic and xmit_rdmaChris Mason2-9/+11
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: use RCU to protect the connection hashChris Mason1-22/+22
The connection hash was almost entirely RCU ready, this just makes the final couple of changes to use RCU instead of spinlocks for everything. Signed-off-by: Chris Mason <chris.mason@oracle.com>