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linux/fs/dlm/ast.h

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193 Based on 1 normalized pattern(s): this copyrighted material is made available to anyone wishing to use modify copy or redistribute it subject to the terms and conditions of the gnu general public license v 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 45 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528170027.342746075@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-28 16:57:20 +00:00
/* SPDX-License-Identifier: GPL-2.0-only */
[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
/******************************************************************************
*******************************************************************************
**
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 17:08:18 +00:00
** Copyright (C) 2005-2010 Red Hat, Inc. All rights reserved.
[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
**
**
*******************************************************************************
******************************************************************************/
#ifndef __ASTD_DOT_H__
#define __ASTD_DOT_H__
fs: dlm: use a non-static queue for callbacks This patch will introducde a queue implementation for callbacks by using the Linux lists. The current callback queue handling is implemented by a static limit of 6 entries, see DLM_CALLBACKS_SIZE. The sequence number inside the callback structure was used to see if the entries inside the static entry is valid or not. We don't need any sequence numbers anymore with a dynamic datastructure with grows and shrinks during runtime to offer such functionality. We assume that every callback will be delivered to the DLM user if once queued. Therefore the callback flag DLM_CB_SKIP was dropped and the check for skipping bast was moved before worker handling and not skip while the callback worker executes. This will reduce unnecessary queues of the callback worker. All last callback saves are pointers now and don't need to copied over. There is a reference counter for callback structures which will care about to free the callback structures at the right time if they are not referenced anymore. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-10-27 20:45:21 +00:00
#define DLM_ENQUEUE_CALLBACK_NEED_SCHED 1
#define DLM_ENQUEUE_CALLBACK_SUCCESS 0
#define DLM_ENQUEUE_CALLBACK_FAILURE -1
dlm: fix race between final callback and remove This patch fixes the following issue: node 1 is dir node 2 is master node 3 is other 1->2: unlock 2: put final lkb, rsb moved to toss 2->1: unlock_reply 1: queue lkb callback with EUNLOCK 2->1: remove 1: receive_remove ignored (rsb on keep because of queued lkb callback) 1: complete lkb callback, put_lkb, move rsb to toss 3->1: lookup 1->3: lookup_reply master=2 3->2: request 2->3: request_reply EBADR In summary: An unexpected lkb reference causes the rsb to remain on the wrong list. The rsb being on the wrong list causes receive_remove to be ignored. An ignored receive_remove causes inconsistent dir and master state. This sequence requires an unusually long delay in delivering the unlock callback, because the remove message from 2->1 usually happens after some seconds. So, it's not known exactly how frequently this sequence occurs in pratice. It's possible that the same end result could also have another unknown cause. The solution for this issue is to further separate callback state from the lkb, so that an lkb reference (and from that, an rsb ref) are not held while a callback remains queued. Then, within the unlock_reply, the lkb will be freed and the rsb moved to the toss list. So, the receive_remove will not be ignored. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2024-03-28 15:48:41 +00:00
int dlm_queue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
int status, uint32_t sbflags,
struct dlm_callback **cb);
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>
2011-04-05 18:16:24 +00:00
void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
uint32_t sbflags);
[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
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>
2011-04-05 18:16:24 +00:00
int dlm_callback_start(struct dlm_ls *ls);
void dlm_callback_stop(struct dlm_ls *ls);
void dlm_callback_suspend(struct dlm_ls *ls);
void dlm_callback_resume(struct dlm_ls *ls);
[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
#endif
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>
2011-04-05 18:16:24 +00:00
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