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path: root/net/rds/connection.c
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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>
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>
2010-09-09RDS: cancel connection work structs as we shut downZach Brown
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>
2010-09-09RDS: don't call rds_conn_shutdown() from rds_conn_destroy()Zach Brown
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>
2010-09-09RDS: have sockets get transport module referencesZach Brown
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>
2010-09-09RDS: lock rds_conn_count decrement in rds_conn_destroy()Zach Brown
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>
2010-09-09RDS: remove __init and __exit annotationZach Brown
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>
2010-09-09RDS: whitespaceAndy Grover
2010-09-09rds: 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>
2010-09-09rds: block ints when acquiring c_lock in rds_conn_message_info()Zach Brown
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>
2010-09-09RDS: 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>
2010-09-09rds: use RCU to protect the connection hashChris Mason
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>
2010-09-09RDS: use locking on the connection hash listChris Mason
rds_conn_destroy really needs locking while it changes the connection hash. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-09rds: 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>
2010-09-09RDS: 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>
2010-09-09RDS: 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>
2010-09-09RDS: fold rdma.h into rds.hAndy Grover
RDMA is now an intrinsic part of RDS, so it's easier to just have a single header. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-09RDS: cleanup: remove "== NULL"s and "!= NULL"s in ptr comparisonsAndy Grover
Favor "if (foo)" style over "if (foo != NULL)". Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-09RDS: move rds_shutdown_worker impl. to rds_conn_shutdownAndy Grover
This fits better in connection.c, rather than threads.c. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h 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>
2009-11-30net: Move && and || to end of previous lineJoe Perches
Not including net/atm/ Compiled tested x86 allyesconfig only Added a > 80 column line or two, which I ignored. Existing checkpatch plaints willfully, cheerfully ignored. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-24RDS: Export symbols from core RDSAndy Grover
Now that rdma and tcp transports will be modularized, we need to export a number of functions so they can call them. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20RDS: Refactor end of __conn_create for readabilityAndy Grover
Add a comment for what's going on. Remove negative logic. I find this much easier to understand quickly, although there are a few lines duplicated. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20RDS: Don't set c_version in __rds_conn_create()Andy Grover
Protocol negotiation is logically a property of the transports, so rds core need not set it. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-10rds: use kmem_cache_zalloc instead of kmem_cache_alloc/memsetWei Yongjun
Use kmem_cache_zalloc instead of kmem_cache_alloc/memset. Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-27RDS: Connection handlingAndy Grover
While arguably the fact that the underlying transport needs a connection to convey RDS's datagrame reliably is not important to rds proper, the transports implemented so far (IB and TCP) have both been connection-oriented, and so the connection state machine-related code is in the common rds code. This patch also includes several work items, to handle connecting, sending, receiving, and shutdown. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>