kernel.git/fs/dlm/lock.c, branch linux-2.6.32.y

dlm: send reply before bast

2010-08-13T20:20:21Z

commit cf6620acc0f6fac57968aafef79ab372bdcf6157 upstream. When the lock master processes a successful operation (request, convert, cancel, or unlock), it will process the effects of the change before sending the reply for the operation. The "effects" of the operation are: - blocking callbacks (basts) for any newly granted locks - waiting or converting locks that can now be granted The cast is queued on the local node when the reply from the lock master is received. This means that a lock holder can receive a bast for a lock mode that is doesn't yet know has been granted. Signed-off-by: David Teigland Signed-off-by: Greg Kroah-Hartman

dlm: fix ordering of bast and cast

2010-08-13T20:20:20Z

commit 7fe2b3190b8b299409f13cf3a6f85c2bd371f8bb upstream. When both blocking and completion callbacks are queued for lock, the dlm would always deliver the completion callback (cast) first. In some cases the blocking callback (bast) is queued before the cast, though, and should be delivered first. This patch keeps track of the order in which they were queued and delivers them in that order. This patch also keeps track of the granted mode in the last cast and eliminates the following bast if the bast mode is compatible with the preceding cast mode. This happens when a remotely mastered lock is demoted, e.g. EX->NL, in which case the local node queues a cast immediately after sending the demote message. In this way a cast can be queued for a mode, e.g. NL, that makes an in-transit bast extraneous. Signed-off-by: David Teigland Signed-off-by: Greg Kroah-Hartman

dlm: always use GFP_NOFS

2010-08-13T20:20:20Z

commit 573c24c4af6664ffcd9aa7ba617a35fde2b95534 upstream. Replace all GFP_KERNEL and ls_allocation with GFP_NOFS. ls_allocation would be GFP_KERNEL for userland lockspaces and GFP_NOFS for file system lockspaces. It was discovered that any lockspaces on the system can affect all others by triggering memory reclaim in the file system which could in turn call back into the dlm to acquire locks, deadlocking dlm threads that were shared by all lockspaces, like dlm_recv. Signed-off-by: David Teigland Signed-off-by: Greg Kroah-Hartman

dlm: Fix uninitialised variable warning in lock.c

2009-06-17T16:31:32Z

CC [M] fs/dlm/lock.o fs/dlm/lock.c: In function ‘find_rsb’: fs/dlm/lock.c:438: warning: ‘r’ may be used uninitialized in this function Since r is used on the error path to set r_ret, set it to NULL. Signed-off-by: Steven Whitehouse Signed-off-by: David Teigland

dlm: ignore cancel on granted lock

2009-03-11T17:23:58Z

Return immediately from dlm_unlock(CANCEL) if the lock is granted and not being converted; there's nothing to cancel. Signed-off-by: David Teigland

dlm: clear defunct cancel state

2009-03-11T17:23:39Z

When a conversion completes successfully and finds that a cancel of the convert is still in progress (which is now a moot point), preemptively clear the state associated with outstanding cancel. That state could cause a subsequent conversion to be ignored. Also, improve the consistency and content of error and debug messages in this area. Signed-off-by: David Teigland

dlm: change rsbtbl rwlock to spinlock

2009-01-08T21:12:39Z

The rwlock is almost always used in write mode, so there's no reason to not use a spinlock instead. Signed-off-by: David Teigland

dlm: add time stamp of blocking callback

2008-12-23T16:18:34Z

Record the time the latest blocking callback was queued for a lock. This will be used for debugging in combination with lock queue timestamp changes in the previous patch. Signed-off-by: David Teigland

dlm: change lock time stamping

2008-12-23T16:18:17Z

Use ktime instead of jiffies for timestamping lkb's. Also stamp the time on every lkb whenever it's added to a resource queue, instead of just stamping locks subject to timeouts. This will allow us to use timestamps more widely for debugging all locks. Signed-off-by: David Teigland

dlm: improve how bast mode handling

2008-12-23T16:16:46Z

The lkb bastmode value is set in the context of processing the lock, and read by the dlm_astd thread. Because it's accessed in these two separate contexts, the writing/reading ought to be done under a lock. This is simple to do by setting it and reading it when the lkb is added to and removed from dlm_astd's callback list which is properly locked. Signed-off-by: David Teigland