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2011-07-19dlm: don't limit active work itemsDavid Teigland
Allow multiple workqueue items (locks with callbacks) to be processed concurrently. There should be no reason not to take advantage of this workqueue feature. Signed-off-by: David Teigland <teigland@redhat.com>
2011-07-15dlm: use workqueue for callbacksDavid Teigland
Instead of creating our own kthread (dlm_astd) to deliver callbacks for all lockspaces, use a per-lockspace workqueue to deliver the callbacks. This eliminates complications and slowdowns from many lockspaces sharing the same thread. Signed-off-by: David Teigland <teigland@redhat.com>
2011-03-10dlm: record full callback stateDavid Teigland
Change how callbacks are recorded for locks. Previously, information about multiple callbacks was combined into a couple of variables that indicated what the end result should be. In some situations, we could not tell from this combined state what the exact sequence of callbacks were, and would end up either delivering the callbacks in the wrong order, or suppress redundant callbacks incorrectly. This new approach records all the data for each callback, leaving no uncertainty about what needs to be delivered. Signed-off-by: David Teigland <teigland@redhat.com>
2010-02-24dlm: fix ordering of bast and castDavid Teigland
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 <teigland@redhat.com>
2008-12-23dlm: fs/dlm/ast.c: fix warningAndrew Morton
fs/dlm/ast.c: In function 'dlm_astd': fs/dlm/ast.c:64: warning: 'bastmode' may be used uninitialized in this function Cleans code up. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Teigland <teigland@redhat.com>
2008-12-23dlm: improve how bast mode handlingDavid Teigland
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 <teigland@redhat.com>
2008-12-23dlm: remove extra blocking callback checkDavid Teigland
Just before delivering a blocking callback (bast), the dlm_astd thread checks again that the granted mode of the lkb actually blocks the mode requested by the bast. The idea behind this was originally that the granted mode may have changed since the bast was queued, making the callback now unnecessary. Reasons for removing this extra check are: - dlm_astd doesn't lock the rsb before reading the lkb grmode, so it's not technically safe (this removes the long standing FIXME) - after running some tests, it doesn't appear the check ever actually eliminates a bast - delivering an unnecessary blocking callback isn't a bad thing and can happen anyway Signed-off-by: David Teigland <teigland@redhat.com>
2008-12-23dlm: replace schedule with cond_reschedSteven Whitehouse
This is a one-liner to use cond_resched() rather than schedule() in the ast delivery loop. It should not be necessary to schedule every time, so this will save some cpu time while continuing to allow scheduling when required. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2008-02-06dlm: proper types for asts and bastsDavid Teigland
Use proper types for ast and bast functions, and use consistent type for ast param. Signed-off-by: David Teigland <teigland@redhat.com>
2007-05-01[DLM] fs/dlm/ast.c should #include "ast.h"Adrian Bunk
Every file should include the headers containing the prototypes for it's global functions. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-08-23[DLM] down conversion clearing flagsDavid Teigland
The down-conversion optimization was resulting in the lkb flags being cleared because the stub message reply had no flags value set. Copy the current flags into the stub message so they'll be copied back into the lkb as part of processing the fake reply. Also add an assertion to catch this error more directly if it exists elsewhere. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-07-13[DLM] dlm: user locksDavid Teigland
This changes the way the dlm handles user locks. The core dlm is now aware of user locks so they can be dealt with more efficiently. There is no more dlm_device module which previously managed its own duplicate copy of every user lock. Signed-off-by: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-01-20[DLM] Update DLM to the latest patch levelDavid Teigland
Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>
2006-01-18[DLM] The core of the DLM for GFS2/CLVMDavid Teigland
This is the core of the distributed lock manager which is required to use GFS2 as a cluster filesystem. It is also used by CLVM and can be used as a standalone lock manager independantly of either of these two projects. It implements VAX-style locking modes. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>