Commit Graph

59 Commits

Author SHA1 Message Date
David Teigland
ef0c2bb05f [DLM] overlapping cancel and unlock
Full cancel and force-unlock support.  In the past, cancel and force-unlock
wouldn't work if there was another operation in progress on the lock.  Now,
both cancel and unlock-force can overlap an operation on a lock, meaning there
may be 2 or 3 operations in progress on a lock in parallel.  This support is
important not only because cancel and force-unlock are explicit operations
that an app can use, but both are used implicitly when a process exits while
holding locks.

Summary of changes:

- add-to and remove-from waiters functions were rewritten to handle situations
  with more than one remote operation outstanding on a lock

- validate_unlock_args detects when an overlapping cancel/unlock-force
  can be sent and when it needs to be delayed until a request/lookup
  reply is received

- processing request/lookup replies detects when cancel/unlock-force
  occured during the op, and carries out the delayed cancel/unlock-force

- manipulation of the "waiters" (remote operation) state of a lock moved under
  the standard rsb mutex that protects all the other lock state

- the two recovery routines related to locks on the waiters list changed
  according to the way lkb's are now locked before accessing waiters state

- waiters recovery detects when lkb's being recovered have overlapping
  cancel/unlock-force, and may not recover such locks

- revert_lock (cancel) returns a value to distinguish cases where it did
  nothing vs cases where it actually did a cancel; the cancel completion ast
  should only be done when cancel did something

- orphaned locks put on new list so they can be found later for purging

- cancel must be called on a lock when making it an orphan

- flag user locks (ENDOFLIFE) at the end of their useful life (to the
  application) so we can return an error for any further cancel/unlock-force

- we weren't setting COMP/BAST ast flags if one was already set, so we'd lose
  either a completion or blocking ast

- clear an unread bast on a lock that's become unlocked

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01 09:11:00 +01:00
Patrick Caulfield
254da030df [DLM] Don't delete misc device if lockspace removal fails
Currently if the lockspace removal fails the misc device associated with a
lockspace is left deleted. After that there is no way to access the orphaned
lockspace from userland.

This patch recreates the misc device if th dlm_release_lockspace fails. I
believe this is better than attempting to remove the lockspace first because
that leaves an unattached device lying around. The potential gap in which there
is no access to the lockspace between removing the misc device and recreating it
is acceptable ... after all the application is trying to remove it, and only new
users of the lockspace will be affected.

Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01 09:10:44 +01:00
Adrian Bunk
84c6e8cd35 [DLM] fs/dlm/user.c should #include "user.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: Steven Whitehouse <swhiteho@redhat.com>
2007-03-07 13:58:21 -05:00
Arjan van de Ven
00977a59b9 [PATCH] mark struct file_operations const 6
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:45 -08:00
David Teigland
a1bc86e6bd [DLM] fix user unlocking
When a user process exits, we clear all the locks it holds.  There is a
problem, though, with locks that the process had begun unlocking before it
exited.  We couldn't find the lkb's that were in the process of being
unlocked remotely, to flag that they are DEAD.  To solve this, we move
lkb's being unlocked onto a new list in the per-process structure that
tracks what locks the process is holding.  We can then go through this
list to flag the necessary lkb's when clearing locks for a process when it
exits.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:36:55 -05:00
David Teigland
c6e6f0ba8f [DLM] force removal of user lockspace
Check if the FORCEFREE flag has been provided from user space.  If so, set
the force option to dlm_release_lockspace() so that any remaining locks
will be freed.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-08-31 12:15:37 -04:00
David Teigland
3609819818 [DLM] fix whitespace damage
My previous dlm patch added trailing whitespace damage, fix that.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-07-21 01:55:41 -04:00
David Teigland
34e22bed19 [DLM] fix leaking user locks
User NOQUEUE lock requests to a remote node that failed with -EAGAIN were
never being removed from a process's list of locks.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-07-20 00:11:15 -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