Commit graph

16 commits

Author SHA1 Message Date
David Teigland
6ad2291624 dlm: fix uninitialized spinlock
Use DEFINE_SPINLOCK for global dlm_cb_seq_spin.

Signed-off-by: David Teigland <teigland@redhat.com>
2012-08-08 11:33:43 -05:00
David Teigland
4875647a08 dlm: fixes for nodir mode
The "nodir" mode (statically assign master nodes instead
of using the resource directory) has always been highly
experimental, and never seriously used.  This commit
fixes a number of problems, making nodir much more usable.

- Major change to recovery: recover all locks and restart
  all in-progress operations after recovery.  In some
  cases it's not possible to know which in-progess locks
  to recover, so recover all.  (Most require recovery
  in nodir mode anyway since rehashing changes most
  master nodes.)

- Change the way nodir mode is enabled, from a command
  line mount arg passed through gfs2, into a sysfs
  file managed by dlm_controld, consistent with the
  other config settings.

- Allow recovering MSTCPY locks on an rsb that has not
  yet been turned into a master copy.

- Ignore RCOM_LOCK and RCOM_LOCK_REPLY recovery messages
  from a previous, aborted recovery cycle.  Base this
  on the local recovery status not being in the state
  where any nodes should be sending LOCK messages for the
  current recovery cycle.

- Hold rsb lock around dlm_purge_mstcpy_locks() because it
  may run concurrently with dlm_recover_master_copy().

- Maintain highbast on process-copy lkb's (in addition to
  the master as is usual), because the lkb can switch
  back and forth between being a master and being a
  process copy as the master node changes in recovery.

- When recovering MSTCPY locks, flag rsb's that have
  non-empty convert or waiting queues for granting
  at the end of recovery.  (Rename flag from LOCKS_PURGED
  to RECOVER_GRANT and similar for the recovery function,
  because it's not only resources with purged locks
  that need grant a grant attempt.)

- Replace a couple of unnecessary assertion panics with
  error messages.

Signed-off-by: David Teigland <teigland@redhat.com>
2012-05-02 14:15:27 -05:00
David Teigland
10d1459faf dlm: don't limit active work items
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>
2011-07-19 14:22:32 -05:00
David Teigland
23e8e1aaac dlm: use workqueue for callbacks
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>
2011-07-15 12:30:43 -05:00
David Teigland
8304d6f24c dlm: record full callback state
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>
2011-03-10 10:40:00 -06:00
David Teigland
7fe2b3190b dlm: fix ordering of bast and cast
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>
2010-02-24 11:46:53 -06:00
Andrew Morton
722d74219e dlm: fs/dlm/ast.c: fix warning
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>
2008-12-23 10:22:56 -06:00
David Teigland
fd22a51bcc dlm: improve how bast mode handling
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>
2008-12-23 10:16:46 -06:00
David Teigland
0333969631 dlm: remove extra blocking callback check
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>
2008-12-23 10:16:32 -06:00
Steven Whitehouse
d61e9aac96 dlm: replace schedule with cond_resched
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>
2008-12-23 10:16:13 -06:00
David Teigland
e5dae548b0 dlm: proper types for asts and basts
Use proper types for ast and bast functions, and use
consistent type for ast param.

Signed-off-by: David Teigland <teigland@redhat.com>
2008-02-06 00:35:45 -06:00
Adrian Bunk
8fa1de386f [DLM] fs/dlm/ast.c should #include "ast.h"
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>
2007-05-01 09:11:25 +01:00
David Teigland
32f105a123 [DLM] down conversion clearing flags
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>
2006-08-23 16:07:31 -04:00
David Teigland
597d0cae0f [DLM] dlm: user locks
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>
2006-07-13 09:25:34 -04:00
David Teigland
901359256b [DLM] Update DLM to the latest patch level
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>
2006-01-20 08:47:07 +00:00
David Teigland
e7fd41792f [DLM] The core of the DLM for GFS2/CLVM
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>
2006-01-18 09:30:29 +00:00