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path: root/drivers/infiniband/ulp/ipoib/ipoib_multicast.c (follow)
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2015-04-15IB/ipoib: Remove IPOIB_MCAST_RUN bitErez Shitrit1-4/+2
After Doug Ledford's changes there is no need in that bit, it's semantic becomes subset of the IPOIB_FLAG_OPER_UP bit. Signed-off-by: Erez Shitrit <erezsh@mellanox.com> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-04-15IB/ipoib: Update broadcast record values after each successful join requestErez Shitrit1-1/+17
Update the cached broadcast record in the priv object after every new join of this broadcast domain group. These values are needed for the port configuration (MTU size) and to all the new multicast (non-broadcast) join requests initial parameters. For example, SM starts with 2K MTU for all the fabric, and after that it restarts (or handover to new SM) with new port configuration of 4K MTU. Without using the new values, the driver will keep its old configuration of 2K and will not apply the new configuration of 4K. Signed-off-by: Erez Shitrit <erezsh@mellanox.com> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-04-15IB/ipoib: drop mcast_mutex usageDoug Ledford1-38/+32
We needed the mcast_mutex when we had to prevent the join completion callback from having the value it stored in mcast->mc overwritten by a delayed return from ib_sa_join_multicast. By storing the return of ib_sa_join_multicast in an intermediate variable, we prevent a delayed return from ib_sa_join_multicast overwriting the valid contents of mcast->mc, and we no longer need a mutex to force the join callback to run after the return of ib_sa_join_multicast. This allows us to do away with the mutex entirely and protect our critical sections with a just a spinlock instead. This is highly desirable as there were some places where we couldn't use a mutex because the code was not allowed to sleep, and so we were currently using a mix of mutex and spinlock to protect what we needed to protect. Now we only have a spin lock and the locking complexity is greatly reduced. Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-04-15IB/ipoib: deserialize multicast joinsDoug Ledford1-168/+82
Allow the ipoib layer to attempt to join all outstanding multicast groups at once. The ib_sa layer will serialize multiple attempts to join the same group, but will process attempts to join different groups in parallel. Take advantage of that. In order to make this happen, change the mcast_join_thread to loop through all needed joins, sending a join request for each one that we still need to join. There are a few special cases we handle though: 1) Don't attempt to join anything but the broadcast group until the join of the broadcast group has succeeded. 2) No longer restart the join task at the end of completion handling. If we completed successfully, we are done. The join task now needs kicked either by mcast_send or mcast_restart_task or mcast_start_thread, but should not need started anytime else except when scheduling a backoff attempt to rejoin. 3) No longer use separate join/completion routines for regular and sendonly joins, pass them all through the same routine and just do the right thing based on the SENDONLY join flag. 4) Only try to join a SENDONLY join twice, then drop the packets and quit trying. We leave the mcast group in the list so that if we get a new packet, all that we have to do is queue up the packet and restart the join task and it will automatically try to join twice and then either send or flush the queue again. Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-04-15IB/ipoib: fix MCAST_FLAG_BUSY usageDoug Ledford1-126/+229
Commit a9c8ba5884 ("IPoIB: Fix usage of uninitialized multicast objects") added a new flag MCAST_JOIN_STARTED, but was not very strict in how it was used. We didn't always initialize the completion struct before we set the flag, and we didn't always call complete on the completion struct from all paths that complete it. And when we did complete it, sometimes we continued to touch the mcast entry after the completion, opening us up to possible use after free issues. This made it less than totally effective, and certainly made its use confusing. And in the flush function we would use the presence of this flag to signal that we should wait on the completion struct, but we never cleared this flag, ever. In order to make things clearer and aid in resolving the rtnl deadlock bug I've been chasing, I cleaned this up a bit. 1) Remove the MCAST_JOIN_STARTED flag entirely 2) Change MCAST_FLAG_BUSY so it now only means a join is in-flight 3) Test mcast->mc directly to see if we have completed ib_sa_join_multicast (using IS_ERR_OR_NULL) 4) Make sure that before setting MCAST_FLAG_BUSY we always initialize the mcast->done completion struct 5) Make sure that before calling complete(&mcast->done), we always clear the MCAST_FLAG_BUSY bit 6) Take the mcast_mutex before we call ib_sa_multicast_join and also take the mutex in our join callback. This forces ib_sa_multicast_join to return and set mcast->mc before we process the callback. This way, our callback can safely clear mcast->mc if there is an error on the join and we will do the right thing as a result in mcast_dev_flush. 7) Because we need the mutex to synchronize mcast->mc, we can no longer call mcast_sendonly_join directly from mcast_send and instead must add sendonly join processing to the mcast_join_task 8) Make MCAST_RUN mean that we have a working mcast subsystem, not that we have a running task. We know when we need to reschedule our join task thread and don't need a flag to tell us. 9) Add a helper for rescheduling the join task thread A number of different races are resolved with these changes. These races existed with the old MCAST_FLAG_BUSY usage, the MCAST_JOIN_STARTED flag was an attempt to address them, and while it helped, a determined effort could still trip things up. One race looks something like this: Thread 1 Thread 2 ib_sa_join_multicast (as part of running restart mcast task) alloc member call callback ifconfig ib0 down wait_for_completion callback call completes wait_for_completion in mcast_dev_flush completes mcast->mc is PTR_ERR_OR_NULL so we skip ib_sa_leave_multicast return from callback return from ib_sa_join_multicast set mcast->mc = return from ib_sa_multicast We now have a permanently unbalanced join/leave issue that trips up the refcounting in core/multicast.c Another like this: Thread 1 Thread 2 Thread 3 ib_sa_multicast_join ifconfig ib0 down priv->broadcast = NULL join_complete wait_for_completion mcast->mc is not yet set, so don't clear return from ib_sa_join_multicast and set mcast->mc complete return -EAGAIN (making mcast->mc invalid) call ib_sa_multicast_leave on invalid mcast->mc, hang forever By holding the mutex around ib_sa_multicast_join and taking the mutex early in the callback, we force mcast->mc to be valid at the time we run the callback. This allows us to clear mcast->mc if there is an error and the join is going to fail. We do this before we complete the mcast. In this way, mcast_dev_flush always sees consistent state in regards to mcast->mc membership at the time that the wait_for_completion() returns. Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-04-15IB/ipoib: No longer use flush as a parameterDoug Ledford1-4/+14
Various places in the IPoIB code had a deadlock related to flushing the ipoib workqueue. Now that we have per device workqueues and a specific flush workqueue, there is no longer a deadlock issue with flushing the device specific workqueues and we can do so unilaterally. Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-04-15IB/ipoib: Use dedicated workqueues per interfaceDoug Ledford1-11/+9
During my recent work on the rtnl lock deadlock in the IPoIB driver, I saw that even once I fixed the apparent races for a single device, as soon as that device had any children, new races popped up. It turns out that this is because no matter how well we protect against races on a single device, the fact that all devices use the same workqueue, and flush_workqueue() flushes *everything* from that workqueue means that we would also have to prevent all races between different devices (for instance, ipoib_mcast_restart_task on interface ib0 can race with ipoib_mcast_flush_dev on interface ib0.8002, resulting in a deadlock on the rtnl_lock). There are several possible solutions to this problem: Make carrier_on_task and mcast_restart_task try to take the rtnl for some set period of time and if they fail, then bail. This runs the real risk of dropping work on the floor, which can end up being its own separate kind of deadlock. Set some global flag in the driver that says some device is in the middle of going down, letting all tasks know to bail. Again, this can drop work on the floor. Or the method this patch attempts to use, which is when we bring an interface up, create a workqueue specifically for that interface, so that when we take it back down, we are flushing only those tasks associated with our interface. In addition, keep the global workqueue, but now limit it to only flush tasks. In this way, the flush tasks can always flush the device specific work queues without having deadlock issues. Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-04-15IB/ipoib: Make the carrier_on_task race awareDoug Ledford1-8/+17
We blindly assume that we can just take the rtnl lock and that will prevent races with downing this interface. Unfortunately, that's not the case. In ipoib_mcast_stop_thread() we will call flush_workqueue() in an attempt to clear out all remaining instances of ipoib_join_task. But, since this task is put on the same workqueue as the join task, the flush_workqueue waits on this thread too. But this thread is deadlocked on the rtnl lock. The better thing here is to use trylock and loop on that until we either get the lock or we see that FLAG_OPER_UP has been cleared, in which case we don't need to do anything anyway and we just return. While investigating which flag should be used, FLAG_ADMIN_UP or FLAG_OPER_UP, it was determined that FLAG_OPER_UP was the more appropriate flag to use. However, there was a mix of these two flags in use in the existing code. So while we check for that flag here as part of this race fix, also cleanup the two places that had used the less appropriate flag for their tests. Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-04-15IB/ipoib: Consolidate rtnl_lock tasks in workqueueDoug Ledford1-6/+2
The ipoib_mcast_flush_dev routine is called with the rtnl_lock held and needs to keep it held. It also needs to call flush_workqueue() to flush out any outstanding work. In the past, we've had to try and make sure that we didn't flush out any outstanding join completions because they also wanted to grab rtnl_lock() and that would deadlock. It turns out that the only thing in the join completion handler that needs this lock can be safely moved to our carrier_on_task, thereby reducing the potential for the join completion code and the flush code to deadlock against each other. Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-01-30Revert "IPoIB: Consolidate rtnl_lock tasks in workqueue"Roland Dreier1-2/+6
This reverts commit afe1de664ef3cb756e70938d99417dcbc6b1379a. The series of IPoIB bug fixes that went into 3.19-rc1 introduce regressions, and after trying to sort things out, we decided to revert to 3.18's IPoIB driver and get things right for 3.20. Signed-off-by: Roland Dreier <roland@purestorage.com>
2015-01-30Revert "IPoIB: Make the carrier_on_task race aware"Roland Dreier1-15/+6
This reverts commit 67d7209e1f481cbaed37f9a224a328a3f83d0482. The series of IPoIB bug fixes that went into 3.19-rc1 introduce regressions, and after trying to sort things out, we decided to revert to 3.18's IPoIB driver and get things right for 3.20. Signed-off-by: Roland Dreier <roland@purestorage.com>
2015-01-30Revert "IPoIB: fix MCAST_FLAG_BUSY usage"Roland Dreier1-93/+55
This reverts commit 016d9fb25cd9817ea9c723f4f7ecd978636b4489. The series of IPoIB bug fixes that went into 3.19-rc1 introduce regressions, and after trying to sort things out, we decided to revert to 3.18's IPoIB driver and get things right for 3.20. Signed-off-by: Roland Dreier <roland@purestorage.com>
2015-01-30Revert "IPoIB: fix mcast_dev_flush/mcast_restart_task race"Roland Dreier1-32/+5
This reverts commit e5d1dcf1b0951f4ba00d93653942dda6196109d8. The series of IPoIB bug fixes that went into 3.19-rc1 introduce regressions, and after trying to sort things out, we decided to revert to 3.18's IPoIB driver and get things right for 3.20. Signed-off-by: Roland Dreier <roland@purestorage.com>
2015-01-30Revert "IPoIB: Use dedicated workqueues per interface"Roland Dreier1-12/+14
This reverts commit 5141861cd5e17eac9676ff49c5abfafbea2b0e98. The series of IPoIB bug fixes that went into 3.19-rc1 introduce regressions, and after trying to sort things out, we decided to revert to 3.18's IPoIB driver and get things right for 3.20. Signed-off-by: Roland Dreier <roland@purestorage.com>
2015-01-30Revert "IPoIB: Make ipoib_mcast_stop_thread flush the workqueue"Roland Dreier1-9/+12
This reverts commit bb42a6dd02fb2901a69dbec2358810735b14b186. The series of IPoIB bug fixes that went into 3.19-rc1 introduce regressions, and after trying to sort things out, we decided to revert to 3.18's IPoIB driver and get things right for 3.20. Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-12-15IPoIB: Make ipoib_mcast_stop_thread flush the workqueueDoug Ledford1-12/+9
We used to pass a flush variable to mcast_stop_thread to indicate if we should flush the workqueue or not. This was due to some code trying to flush a workqueue that it was currently running on which is a no-no. Now that we have per-device work queues, and now that ipoib_mcast_restart_task has taken the fact that it is queued on a single thread workqueue with all of the ipoib_mcast_join_task's and therefore has no need to stop the join task while it runs, we can do away with the flush parameter and unilaterally flush always. Signed-off-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-12-15IPoIB: Use dedicated workqueues per interfaceDoug Ledford1-14/+12
During my recent work on the rtnl lock deadlock in the IPoIB driver, I saw that even once I fixed the apparent races for a single device, as soon as that device had any children, new races popped up. It turns out that this is because no matter how well we protect against races on a single device, the fact that all devices use the same workqueue, and flush_workqueue() flushes *everything* from that workqueue, we can have one device in the middle of a down and holding the rtnl lock and another totally unrelated device needing to run mcast_restart_task, which wants the rtnl lock and will loop trying to take it unless is sees its own FLAG_ADMIN_UP flag go away. Because the unrelated interface will never see its own ADMIN_UP flag drop, the interface going down will deadlock trying to flush the queue. There are several possible solutions to this problem: Make carrier_on_task and mcast_restart_task try to take the rtnl for some set period of time and if they fail, then bail. This runs the real risk of dropping work on the floor, which can end up being its own separate kind of deadlock. Set some global flag in the driver that says some device is in the middle of going down, letting all tasks know to bail. Again, this can drop work on the floor. I suppose if our own ADMIN_UP flag doesn't go away, then maybe after a few tries on the rtnl lock we can queue our own task back up as a delayed work and return and avoid dropping work on the floor that way. But I'm not 100% convinced that we won't cause other problems. Or the method this patch attempts to use, which is when we bring an interface up, create a workqueue specifically for that interface, so that when we take it back down, we are flushing only those tasks associated with our interface. In addition, keep the global workqueue, but now limit it to only flush tasks. In this way, the flush tasks can always flush the device specific work queues without having deadlock issues. Signed-off-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-12-15IPoIB: fix mcast_dev_flush/mcast_restart_task raceDoug Ledford1-5/+32
Our mcast_dev_flush routine and our mcast_restart_task can race against each other. In particular, they both hold the priv->lock while manipulating the rbtree and while removing mcast entries from the multicast_list and while adding entries to the remove_list, but they also both drop their locks prior to doing the actual removes. The mcast_dev_flush routine is run entirely under the rtnl lock and so has at least some locking. The actual race condition is like this: Thread 1 Thread 2 ifconfig ib0 up start multicast join for broadcast multicast join completes for broadcast start to add more multicast joins call mcast_restart_task to add new entries ifconfig ib0 down mcast_dev_flush mcast_leave(mcast A) mcast_leave(mcast A) As mcast_leave calls ib_sa_multicast_leave, and as member in core/multicast.c is ref counted, we run into an unbalanced refcount issue. To avoid stomping on each others removes, take the rtnl lock specifically when we are deleting the entries from the remove list. Signed-off-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-12-15IPoIB: fix MCAST_FLAG_BUSY usageDoug Ledford1-55/+93
Commit a9c8ba5884 ("IPoIB: Fix usage of uninitialized multicast objects") added a new flag MCAST_JOIN_STARTED, but was not very strict in how it was used. We didn't always initialize the completion struct before we set the flag, and we didn't always call complete on the completion struct from all paths that complete it. This made it less than totally effective, and certainly made its use confusing. And in the flush function we would use the presence of this flag to signal that we should wait on the completion struct, but we never cleared this flag, ever. This is further muddied by the fact that we overload the MCAST_FLAG_BUSY flag to mean two different things: we have a join in flight, and we have succeeded in getting an ib_sa_join_multicast. In order to make things clearer and aid in resolving the rtnl deadlock bug I've been chasing, I cleaned this up a bit. 1) Remove the MCAST_JOIN_STARTED flag entirely 2) Un-overload MCAST_FLAG_BUSY so it now only means a join is in-flight 3) Test on mcast->mc directly to see if we have completed ib_sa_join_multicast (using IS_ERR_OR_NULL) 4) Make sure that before setting MCAST_FLAG_BUSY we always initialize the mcast->done completion struct 5) Make sure that before calling complete(&mcast->done), we always clear the MCAST_FLAG_BUSY bit 6) Take the mcast_mutex before we call ib_sa_multicast_join and also take the mutex in our join callback. This forces ib_sa_multicast_join to return and set mcast->mc before we process the callback. This way, our callback can safely clear mcast->mc if there is an error on the join and we will do the right thing as a result in mcast_dev_flush. 7) Because we need the mutex to synchronize mcast->mc, we can no longer call mcast_sendonly_join directly from mcast_send and instead must add sendonly join processing to the mcast_join_task A number of different races are resolved with these changes. These races existed with the old MCAST_FLAG_BUSY usage, the MCAST_JOIN_STARTED flag was an attempt to address them, and while it helped, a determined effort could still trip things up. One race looks something like this: Thread 1 Thread 2 ib_sa_join_multicast (as part of running restart mcast task) alloc member call callback ifconfig ib0 down wait_for_completion callback call completes wait_for_completion in mcast_dev_flush completes mcast->mc is PTR_ERR_OR_NULL so we skip ib_sa_leave_multicast return from callback return from ib_sa_join_multicast set mcast->mc = return from ib_sa_multicast We now have a permanently unbalanced join/leave issue that trips up the refcounting in core/multicast.c Another like this: Thread 1 Thread 2 Thread 3 ib_sa_multicast_join ifconfig ib0 down priv->broadcast = NULL join_complete wait_for_completion mcast->mc is not yet set, so don't clear return from ib_sa_join_multicast and set mcast->mc complete return -EAGAIN (making mcast->mc invalid) call ib_sa_multicast_leave on invalid mcast->mc, hang forever By holding the mutex around ib_sa_multicast_join and taking the mutex early in the callback, we force mcast->mc to be valid at the time we run the callback. This allows us to clear mcast->mc if there is an error and the join is going to fail. We do this before we complete the mcast. In this way, mcast_dev_flush always sees consistent state in regards to mcast->mc membership at the time that the wait_for_completion() returns. Signed-off-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-12-15IPoIB: Make the carrier_on_task race awareDoug Ledford1-6/+15
We blindly assume that we can just take the rtnl lock and that will prevent races with downing this interface. Unfortunately, that's not the case. In ipoib_mcast_stop_thread() we will call flush_workqueue() in an attempt to clear out all remaining instances of ipoib_join_task. But, since this task is put on the same workqueue as the join task, the flush_workqueue waits on this thread too. But this thread is deadlocked on the rtnl lock. The better thing here is to use trylock and loop on that until we either get the lock or we see that FLAG_ADMIN_UP has been cleared, in which case we don't need to do anything anyway and we just return. Signed-off-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-12-15IPoIB: Consolidate rtnl_lock tasks in workqueueDoug Ledford1-6/+2
Setting the MTU can safely be moved to the carrier_on_task, which keeps us from needing to take the rtnl lock in the join_finish section. Signed-off-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-09-19IPoIB: Remove unnecessary port queryAlex Estrin1-9/+1
There are two queries for port attributes one after another. A second call is not needed since port_attr structure already holds the data. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Alex Estrin <alex.estrin@intel.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IPoIB: Start multicast join process only on active portsErez Shitrit1-0/+8
The driver starts the mcast_join task whenever the netdev interface is UP without relation to the underlying IB port state. Until the port state is ACTIVE all the join requests are irrelevant, and the IB core returns -EINVAL. So the user will see errors such as: "multicast join failed for ff12:401b:... , status -22". Instead, have ipoib_mcast_join_task() return when the port is not active. It will be called again when the port state is changed and the low-level driver triggers the IB_EVENT_PORT_ACTIVE event or the IB_EVENT_CLIENT_REREGISTER event. Signed-off-by: Erez Shitrit <erezsh@mellanox.com> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IPoIB: Fix usage of uninitialized multicast objectsErez Shitrit1-4/+17
The driver should avoid calling ib_sa_free_multicast on the mcast->mc object until it finishes its initialization state. Otherwise we can crash when ipoib_mcast_dev_flush() attempts to use the uninitialized multicast object. Instead, only call wait_for_completion() for multicast entries that started the join process, meaning that ib_sa_join_multicast() finished. Signed-off-by: Erez Shitrit <erezsh@mellanox.com> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-09-30IPoIB: Fix use-after-free of multicast objectPatrick McHardy1-9/+10
Fix a crash in ipoib_mcast_join_task(). (with help from Or Gerlitz) Commit c8c2afe360b7 ("IPoIB: Use rtnl lock/unlock when changing device flags") added a call to rtnl_lock() in ipoib_mcast_join_task(), which is run from the ipoib_workqueue, and hence the workqueue can't be flushed from the context of ipoib_stop(). In the current code, ipoib_stop() (which doesn't flush the workqueue) calls ipoib_mcast_dev_flush(), which goes and deletes all the multicast entries. This takes place without any synchronization with a possible running instance of ipoib_mcast_join_task() for the same ipoib device, leading to a crash due to NULL pointer dereference. Fix this by making sure that the workqueue is flushed before ipoib_mcast_dev_flush() is called. To make that possible, we move the RTNL-lock wrapped code to ipoib_mcast_join_finish(). Signed-off-by: Patrick McHardy <kaber@trash.net> Cc: <stable@vger.kernel.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-09-12IPoIB: Fix AB-BA deadlock when deleting neighboursShlomo Pongratz1-2/+0
Lockdep points out a circular locking dependency betwwen the ipoib device priv spinlock (priv->lock) and the neighbour table rwlock (ntbl->rwlock). In the normal path, ie neigbour garbage collection task, the neigh table rwlock is taken first and then if the neighbour needs to be deleted, priv->lock is taken. However in some error paths, such as in ipoib_cm_handle_tx_wc(), priv->lock is taken first and then ipoib_neigh_free routine is called which in turn takes the neighbour table ntbl->rwlock. The solution is to get rid the neigh table rwlock completely and use only priv->lock. Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-07-30IPoIB: Use a private hash table for path lookup in xmit pathShlomo Pongratz1-38/+19
Dave Miller <davem@davemloft.net> provided a detailed description of why the way IPoIB is using neighbours for its own ipoib_neigh struct is buggy: Any time an ipoib_neigh is changed, a sequence like the following is made: spin_lock_irqsave(&priv->lock, flags); /* * It's safe to call ipoib_put_ah() inside * priv->lock here, because we know that * path->ah will always hold one more reference, * so ipoib_put_ah() will never do more than * decrement the ref count. */ if (neigh->ah) ipoib_put_ah(neigh->ah); list_del(&neigh->list); ipoib_neigh_free(dev, neigh); spin_unlock_irqrestore(&priv->lock, flags); ipoib_path_lookup(skb, n, dev); This doesn't work, because you're leaving a stale pointer to the freed up ipoib_neigh in the special neigh->ha pointer cookie. Yes, it even fails with all the locking done to protect _changes_ to *ipoib_neigh(n), and with the code in ipoib_neigh_free() that NULLs out the pointer. The core issue is that read side calls to *to_ipoib_neigh(n) are not being synchronized at all, they are performed without any locking. So whether we hold the lock or not when making changes to *ipoib_neigh(n) you still can have threads see references to freed up ipoib_neigh objects. cpu 1 cpu 2 n = *ipoib_neigh() *ipoib_neigh() = NULL kfree(n) n->foo == OOPS [..] Perhaps the ipoib code can have a private path database it manages entirely itself, which holds all the necessary information and is looked up by some generic key which is available easily at transmit time and does not involve generic neighbour entries. See <http://marc.info/?l=linux-rdma&m=132812793105624&w=2> and <http://marc.info/?l=linux-rdma&w=2&r=1&s=allows+references+to+freed+memory&q=b> for the full discussion. This patch aims to solve the race conditions found in the IPoIB driver. The patch removes the connection between the core networking neighbour structure and the ipoib_neigh structure. In addition to avoiding the race described above, it allows us to handle SKBs carrying IP packets that don't have any associated neighbour. We add an ipoib_neigh hash table with N buckets where the key is the destination hardware address. The ipoib_neigh is fetched from the hash table and instead of the stashed location in the neighbour structure. The hash table uses both RCU and reference counting to guarantee that no ipoib_neigh instance is ever deleted while in use. Fetching the ipoib_neigh structure instance from the hash also makes the special code in ipoib_start_xmit that handles remote and local bonding failover redundant. Aged ipoib_neigh instances are deleted by a garbage collection task that runs every M seconds and deletes every ipoib_neigh instance that was idle for at least 2*M seconds. The deletion is safe since the ipoib_neigh instances are protected using RCU and reference count mechanisms. The number of buckets (N) and frequency of running the GC thread (M), are taken from the exported arb_tbl. Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-07-05ipoib: Need to do dst_neigh_lookup_skb() outside of priv->lock.David S. Miller1-7/+8
Otherwise local_bh_enable() complains. Reported-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05ipoib: Convert over to dev_lookup_neigh_skb().David S. Miller1-9/+13
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-08IPoIB: Stop lying about hard_header_len and use skb->cb to stash LL addressesRoland Dreier1-9/+1
Commit a0417fa3a18a ("net: Make qdisc_skb_cb upper size bound explicit.") made it possible for a netdev driver to use skb->cb between its header_ops.create method and its .ndo_start_xmit method. Use this in ipoib_hard_header() to stash away the LL address (GID + QPN), instead of the "ipoib_pseudoheader" hack. This allows IPoIB to stop lying about its hard_header_len, which will let us fix the L2 check for GRO. Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-05net: Rename dst_get_neighbour{, _raw} to dst_get_neighbour_noref{, _raw}.David Miller1-2/+2
To reflect the fact that a refrence is not obtained to the resulting neighbour entry. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Roland Dreier <roland@purestorage.com>
2011-11-29Merge branches 'cxgb4', 'ipoib', 'misc' and 'qib' into for-nextRoland Dreier1-4/+9
2011-11-29IB: Fix RCU lockdep splatsEric Dumazet1-2/+4
Commit f2c31e32b37 ("net: fix NULL dereferences in check_peer_redir()") forgot to take care of infiniband uses of dst neighbours. Many thanks to Marc Aurele who provided a nice bug report and feedback. Reported-by: Marc Aurele La France <tsi@ualberta.ca> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Miller <davem@davemloft.net> Cc: <stable@kernel.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2011-11-29IB/ipoib: Prevent hung task or softlockup processing multicast responseMike Marciniszyn1-2/+5
This following can occur with ipoib when processing a multicast reponse: BUG: soft lockup - CPU#0 stuck for 67s! [ib_mad1:982] Modules linked in: ... CPU 0: Modules linked in: ... Pid: 982, comm: ib_mad1 Not tainted 2.6.32-131.0.15.el6.x86_64 #1 ProLiant DL160 G5 RIP: 0010:[<ffffffff814ddb27>] [<ffffffff814ddb27>] _spin_unlock_irqrestore+0x17/0x20 RSP: 0018:ffff8802119ed860 EFLAGS: 00000246 0000000000000004 RBX: ffff8802119ed860 RCX: 000000000000a299 RDX: ffff88021086c700 RSI: 0000000000000246 RDI: 0000000000000246 RBP: ffffffff8100bc8e R08: ffff880210ac229c R09: 0000000000000000 R10: ffff88021278aab8 R11: 0000000000000000 R12: ffff8802119ed860 R13: ffffffff8100be6e R14: 0000000000000001 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff880028200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b CR2: 00000000006d4840 CR3: 0000000209aa5000 CR4: 00000000000406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: [<ffffffffa032c247>] ? ipoib_mcast_send+0x157/0x480 [ib_ipoib] [<ffffffff8100bc8e>] ? apic_timer_interrupt+0xe/0x20 [<ffffffff8100bc8e>] ? apic_timer_interrupt+0xe/0x20 [<ffffffffa03283d4>] ? ipoib_path_lookup+0x124/0x2d0 [ib_ipoib] [<ffffffffa03286fc>] ? ipoib_start_xmit+0x17c/0x430 [ib_ipoib] [<ffffffff8141e758>] ? dev_hard_start_xmit+0x2c8/0x3f0 [<ffffffff81439d0a>] ? sch_direct_xmit+0x15a/0x1c0 [<ffffffff81423098>] ? dev_queue_xmit+0x388/0x4d0 [<ffffffffa032d6b7>] ? ipoib_mcast_join_finish+0x2c7/0x510 [ib_ipoib] [<ffffffffa032dab8>] ? ipoib_mcast_sendonly_join_complete+0x1b8/0x1f0 [ib_ipoib] [<ffffffffa02a0946>] ? mcast_work_handler+0x1a6/0x710 [ib_sa] [<ffffffffa015f01e>] ? ib_send_mad+0xfe/0x3c0 [ib_mad] [<ffffffffa00f6c93>] ? ib_get_cached_lmc+0xa3/0xb0 [ib_core] [<ffffffffa02a0f9b>] ? join_handler+0xeb/0x200 [ib_sa] [<ffffffffa029e4fc>] ? ib_sa_mcmember_rec_callback+0x5c/0xa0 [ib_sa] [<ffffffffa029e79c>] ? recv_handler+0x3c/0x70 [ib_sa] [<ffffffffa01603a4>] ? ib_mad_completion_handler+0x844/0x9d0 [ib_mad] [<ffffffffa015fb60>] ? ib_mad_completion_handler+0x0/0x9d0 [ib_mad] [<ffffffff81088830>] ? worker_thread+0x170/0x2a0 [<ffffffff8108e160>] ? autoremove_wake_function+0x0/0x40 [<ffffffff810886c0>] ? worker_thread+0x0/0x2a0 [<ffffffff8108ddf6>] ? kthread+0x96/0xa0 [<ffffffff8100c1ca>] ? child_rip+0xa/0x20 Coinciding with stack trace is the following message: ib0: ib_address_create failed The code below in ipoib_mcast_join_finish() will note the above failure in the address handle but otherwise continue: ah = ipoib_create_ah(dev, priv->pd, &av); if (!ah) { ipoib_warn(priv, "ib_address_create failed\n"); } else { The while loop at the bottom of ipoib_mcast_join_finish() will attempt to send queued multicast packets in mcast->pkt_queue and eventually end up in ipoib_mcast_send(): if (!mcast->ah) { if (skb_queue_len(&mcast->pkt_queue) < IPOIB_MAX_MCAST_QUEUE) skb_queue_tail(&mcast->pkt_queue, skb); else { ++dev->stats.tx_dropped; dev_kfree_skb_any(skb); } My read is that the code will requeue the packet and return to the ipoib_mcast_join_finish() while loop and the stage is set for the "hung" task diagnostic as the while loop never sees a non-NULL ah, and will do nothing to resolve. There are GFP_ATOMIC allocates in the provider routines, so this is possible and should be dealt with. The test that induced the failure is associated with a host SM on the same server during a shutdown. This patch causes ipoib_mcast_join_finish() to exit with an error which will flush the queued mcast packets. Nothing is done to unwind the QP attached state so that subsequent sends from above will retry the join. Reviewed-by: Ram Vepa <ram.vepa@qlogic.com> Reviewed-by: Gary Leshner <gary.leshner@qlogic.com> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2011-10-31infiniband: add moduleparam.h to drivers/infiniband as requiredPaul Gortmaker1-0/+1
These files were getting the moduleparam infrastructure from the implicit presence of module.h being everywhere, but that is going away soon. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-07-17net: Abstract dst->neighbour accesses behind helpers.David S. Miller1-7/+13
dst_{get,set}_neighbour() Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-11Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6David S. Miller1-0/+1
Conflicts: drivers/net/stmmac/stmmac_main.c drivers/net/wireless/wl12xx/wl1271_cmd.c drivers/net/wireless/wl12xx/wl1271_main.c drivers/net/wireless/wl12xx/wl1271_spi.c net/core/ethtool.c net/mac80211/scan.c
2010-04-03net: convert multicast list to list_headJiri Pirko1-5/+4
Converts the list and the core manipulating with it to be the same as uc_list. +uses two functions for adding/removing mc address (normal and "global" variant) instead of a function parameter. +removes dev_mcast.c completely. +exposes netdev_hw_addr_list_* macros along with __hw_addr_* functions for manipulation with lists on a sandbox (used in bonding and 80211 drivers) Signed-off-by: Jiri Pirko <jpirko@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.hTejun Heo1-0/+1
percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-22ipoib: remove addrlen check for mc addressesJiri Pirko1-5/+1
Finally this bit can be removed. Currently, after the bonding driver is changed/fixed (32a806c194ea112cfab00f558482dd97bee5e44e net-next-2.6), that's not possible for an addr with different length than dev->addr_len to be present in list. Removing this check as in new mc_list there will be no addrlen in the record. Signed-off-by: Jiri Pirko <jpirko@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-28ipoib: returned back addrlen check for mc addressesJiri Pirko1-1/+5
Apparently bogus mc address can break IPOIB multicast processing. Therefore returning the check for addrlen back until this is resolved in bonding (I don't see any other point from where mc address with non-dev->addr_len length can came from). Signed-off-by: Jiri Pirko <jpirko@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-26infiniband: convert to use netdev_for_each_mc_addrJiri Pirko1-6/+2
Due to the loop complexicity in nes_nic.c, I'm using char* to copy mc addresses to it. Signed-off-by: Jiri Pirko <jpirko@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-24IPoIB: Don't turn on carrier for a non-active portMoni Shoua1-0/+7
Multicast joins can succeed even if the IB port is down. This happens when the SM runs on the same port with the requesting port. However, IPoIB calls netif_carrier_on() when the join of the broadcast group succeeds, without caring about the state of the IB port. The result is an IPoIB interface in RUNNING state but without an active IB port to support it. If a bonding interface uses this IPoIB interface as a slave it might not detect that this slave is almost useless and failover functionality will be damaged. The fix checks the state of the IB port in the carrier_task before calling netif_carrier_on(). Adresses: https://bugs.openfabrics.org/show_bug.cgi?id=1726 Signed-off-by: Moni Shoua <monis@voltaire.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2009-09-05IPoIB: Check multicast address formatJason Gunthorpe1-0/+19
Check that the format of multicast link addresses is correct before taking them from dev->mc_list to priv->multicast_list. This way we never try to send a bogus address to the SA, which prevents badness from erronous 'ip maddr addr add', broken bonding drivers, etc. Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2009-09-05IPoIB: Drop priv->lock before calling ipoib_send()Roland Dreier1-0/+2
IPoIB currently must use irqsave locking for priv->lock, since it is taken from interrupt context in one path. However, ipoib_send() does skb_orphan(), and the network stack locking is not IRQ-safe. Therefore we need to make sure we don't hold priv->lock when calling ipoib_send() to avoid lockdep warnings (the code was almost certainly safe in practice, since the only code path that takes priv->lock from interrupt context would never call into the network stack). Addresses: http://bugzilla.kernel.org/show_bug.cgi?id=13757 Reported-by: Bart Van Assche <bart.vanassche@gmail.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2009-06-03net: skb->dst accessorsEric Dumazet1-5/+5
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>
2009-01-16IPoIB: Do not print error messages for multicast join retriesYossi Etigin1-1/+1
When IPoIB tries to join a multicast group, and the SA module's SM address handle is NULL (because of an SM change, etc), the join returns with -EAGAIN status. In that case, don't print an error message unless multicast debugging is enabled. Signed-off-by: Yossi Etigin <yosefe@voltaire.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2009-01-12IPoIB: Do not join broadcast group if interface is brought downYossi Etigin1-0/+3
Because the ipoib_workqueue is not flushed when ipoib interface is brought down, ipoib_mcast_join() may trigger a join to the broadcast group after priv->broadcast was set to NULL (during cleanup). This will cause the system to be a member of the broadcast group when interface is down. As a side effect, this breaks the optimization of setting the Q_key only when joining the broadcast group. Signed-off-by: Yossi Etigin <yosefe@voltaire.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-10-29net: replace %p6 with %pI6Harvey Harrison1-15/+15
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-28infiniband: ipoib replace IPOIB_GID_FMT with %p6Harvey Harrison1-41/+29
Replace all uses of IPOIB_GID_FMT, IPOIB_GID_RAW_ARG() and IPOIB_GID_ARG() Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>