linux/fs/ocfs2/dlm/dlmlock.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * dlmlock.c
 *
 * underlying calls for lock creation
 *
 * Copyright (C) 2004 Oracle.  All rights reserved.
 */


#include <linux/module.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/random.h>
#include <linux/blkdev.h>
#include <linux/socket.h>
#include <linux/inet.h>
#include <linux/spinlock.h>
#include <linux/delay.h>


#include "../cluster/heartbeat.h"
#include "../cluster/nodemanager.h"
#include "../cluster/tcp.h"

#include "dlmapi.h"
#include "dlmcommon.h"

#include "dlmconvert.h"

#define MLOG_MASK_PREFIX …
#include "../cluster/masklog.h"

static struct kmem_cache *dlm_lock_cache;

static DEFINE_SPINLOCK(dlm_cookie_lock);
static u64 dlm_next_cookie = …;

static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
					       struct dlm_lock_resource *res,
					       struct dlm_lock *lock, int flags);
static void dlm_init_lock(struct dlm_lock *newlock, int type,
			  u8 node, u64 cookie);
static void dlm_lock_release(struct kref *kref);
static void dlm_lock_detach_lockres(struct dlm_lock *lock);

int dlm_init_lock_cache(void)
{ … }

void dlm_destroy_lock_cache(void)
{ … }

/* Tell us whether we can grant a new lock request.
 * locking:
 *   caller needs:  res->spinlock
 *   taken:         none
 *   held on exit:  none
 * returns: 1 if the lock can be granted, 0 otherwise.
 */
static int dlm_can_grant_new_lock(struct dlm_lock_resource *res,
				  struct dlm_lock *lock)
{ … }

/* performs lock creation at the lockres master site
 * locking:
 *   caller needs:  none
 *   taken:         takes and drops res->spinlock
 *   held on exit:  none
 * returns: DLM_NORMAL, DLM_NOTQUEUED
 */
static enum dlm_status dlmlock_master(struct dlm_ctxt *dlm,
				      struct dlm_lock_resource *res,
				      struct dlm_lock *lock, int flags)
{ … }

void dlm_revert_pending_lock(struct dlm_lock_resource *res,
			     struct dlm_lock *lock)
{ … }


/*
 * locking:
 *   caller needs:  none
 *   taken:         takes and drops res->spinlock
 *   held on exit:  none
 * returns: DLM_DENIED, DLM_RECOVERING, or net status
 */
static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
				      struct dlm_lock_resource *res,
				      struct dlm_lock *lock, int flags)
{ … }


/* for remote lock creation.
 * locking:
 *   caller needs:  none, but need res->state & DLM_LOCK_RES_IN_PROGRESS
 *   taken:         none
 *   held on exit:  none
 * returns: DLM_NOLOCKMGR, or net status
 */
static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
					       struct dlm_lock_resource *res,
					       struct dlm_lock *lock, int flags)
{ … }

void dlm_lock_get(struct dlm_lock *lock)
{ … }

void dlm_lock_put(struct dlm_lock *lock)
{ … }

static void dlm_lock_release(struct kref *kref)
{ … }

/* associate a lock with it's lockres, getting a ref on the lockres */
void dlm_lock_attach_lockres(struct dlm_lock *lock,
			     struct dlm_lock_resource *res)
{ … }

/* drop ref on lockres, if there is still one associated with lock */
static void dlm_lock_detach_lockres(struct dlm_lock *lock)
{ … }

static void dlm_init_lock(struct dlm_lock *newlock, int type,
			  u8 node, u64 cookie)
{ … }

struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
			       struct dlm_lockstatus *lksb)
{ … }

/* handler for lock creation net message
 * locking:
 *   caller needs:  none
 *   taken:         takes and drops res->spinlock
 *   held on exit:  none
 * returns: DLM_NORMAL, DLM_SYSERR, DLM_IVLOCKID, DLM_NOTQUEUED
 */
int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data,
			    void **ret_data)
{ … }


/* fetch next node-local (u8 nodenum + u56 cookie) into u64 */
static inline void dlm_get_next_cookie(u8 node_num, u64 *cookie)
{ … }

enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode,
			struct dlm_lockstatus *lksb, int flags,
			const char *name, int namelen, dlm_astlockfunc_t *ast,
			void *data, dlm_bastlockfunc_t *bast)
{ … }
EXPORT_SYMBOL_GPL(…);