dlm.h

Go to the documentation of this file.

/******************************************************************************
*******************************************************************************
**
**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
**  Copyright (C) 2004-2011 Red Hat, Inc.  All rights reserved.
**
**  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.
**
*******************************************************************************
******************************************************************************/

#ifndef _UAPI__DLM_DOT_H__
#define _UAPI__DLM_DOT_H__

/*
 * Interface to Distributed Lock Manager (DLM)
 * routines and structures to use DLM lockspaces
 */

/* Lock levels and flags are here */
#include <linux/dlmconstants.h>
#include <linux/types.h>

typedef void dlm_lockspace_t;

/*
 * Lock status block
 *
 * Use this structure to specify the contents of the lock value block.  For a
 * conversion request, this structure is used to specify the lock ID of the
 * lock.  DLM writes the status of the lock request and the lock ID assigned
 * to the request in the lock status block.
 *
 * sb_lkid: the returned lock ID.  It is set on new (non-conversion) requests.
 * It is available when dlm_lock returns.
 *
 * sb_lvbptr: saves or returns the contents of the lock's LVB according to rules
 * shown for the DLM_LKF_VALBLK flag.
 *
 * sb_flags: DLM_SBF_DEMOTED is returned if in the process of promoting a lock,
 * it was first demoted to NL to avoid conversion deadlock.
 * DLM_SBF_VALNOTVALID is returned if the resource's LVB is marked invalid.
 *
 * sb_status: the returned status of the lock request set prior to AST
 * execution.  Possible return values:
 *
 * 0 if lock request was successful
 * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE
 * -DLM_EUNLOCK if unlock request was successful
 * -DLM_ECANCEL if a cancel completed successfully
 * -EDEADLK if a deadlock was detected
 * -ETIMEDOUT if the lock request was canceled due to a timeout
 */

#define DLM_SBF_DEMOTED     0x01
#define DLM_SBF_VALNOTVALID 0x02
#define DLM_SBF_ALTMODE     0x04

struct dlm_lksb {
    int      sb_status;
    __u32    sb_lkid;
    char     sb_flags;
    char *   sb_lvbptr;
};

/* dlm_new_lockspace() flags */

#define DLM_LSFL_TIMEWARN   0x00000002
#define DLM_LSFL_FS         0x00000004
#define DLM_LSFL_NEWEXCL        0x00000008


#endif /* _UAPI__DLM_DOT_H__ */