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/******************************************************************************

*******************************************************************************

**

**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.

**  Copyright (C) 2004-2007 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 __DLM_DOT_H__

#define __DLM_DOT_H__

/*

 * Interface to Distributed Lock Manager (DLM)

 * routines and structures to use DLM lockspaces

 */

/*

 * Lock Modes

 */

#define DLM_LOCK_IV             -1      /* invalid */

#define DLM_LOCK_NL             0        /* null */

#define DLM_LOCK_CR             1       /* concurrent read */

#define DLM_LOCK_CW             2       /* concurrent write */

#define DLM_LOCK_PR             3       /* protected read */

#define DLM_LOCK_PW             4       /* protected write */

#define DLM_LOCK_EX             5       /* exclusive */

/*

 * Maximum size in bytes of a dlm_lock name

 */

#define DLM_RESNAME_MAXLEN      64

/*

 * Flags to dlm_lock

 *

 * DLM_LKF_NOQUEUE

 *

 * Do not queue the lock request on the wait queue if it cannot be granted

 * immediately.  If the lock cannot be granted because of this flag, DLM will

 * either return -EAGAIN from the dlm_lock call or will return 0 from

 * dlm_lock and -EAGAIN in the lock status block when the AST is executed.

 *

 * DLM_LKF_CANCEL

 *

 * Used to cancel a pending lock request or conversion.  A converting lock is

 * returned to its previously granted mode.

 *

 * DLM_LKF_CONVERT

 *

 * Indicates a lock conversion request.  For conversions the name and namelen

 * are ignored and the lock ID in the LKSB is used to identify the lock.

 *

 * DLM_LKF_VALBLK

 *

 * Requests DLM to return the current contents of the lock value block in the

 * lock status block.  When this flag is set in a lock conversion from PW or EX

 * modes, DLM assigns the value specified in the lock status block to the lock

 * value block of the lock resource.  The LVB is a DLM_LVB_LEN size array

 * containing application-specific information.

 *

 * DLM_LKF_QUECVT

 *

 * Force a conversion request to be queued, even if it is compatible with

 * the granted modes of other locks on the same resource.

 *

 * DLM_LKF_IVVALBLK

 *

 * Invalidate the lock value block.

 *

 * DLM_LKF_CONVDEADLK

 *

 * Allows the dlm to resolve conversion deadlocks internally by demoting the

 * granted mode of a converting lock to NL.  The DLM_SBF_DEMOTED flag is

 * returned for a conversion that's been effected by this.

 *

 * DLM_LKF_PERSISTENT

 *

 * Only relevant to locks originating in userspace.  A persistent lock will not

 * be removed if the process holding the lock exits.

 *

 * DLM_LKF_NODLCKWT

 *

 * Do not cancel the lock if it gets into conversion deadlock.

 * Exclude this lock from being monitored due to DLM_LSFL_TIMEWARN.

 *

 * DLM_LKF_NODLCKBLK

 *

 * net yet implemented

 *

 * DLM_LKF_EXPEDITE

 *

 * Used only with new requests for NL mode locks.  Tells the lock manager

 * to grant the lock, ignoring other locks in convert and wait queues.

 *

 * DLM_LKF_NOQUEUEBAST

 *

 * Send blocking AST's before returning -EAGAIN to the caller.  It is only

 * used along with the NOQUEUE flag.  Blocking AST's are not sent for failed

 * NOQUEUE requests otherwise.

 *

 * DLM_LKF_HEADQUE

 *

 * Add a lock to the head of the convert or wait queue rather than the tail.

 *

 * DLM_LKF_NOORDER

 *

 * Disregard the standard grant order rules and grant a lock as soon as it

 * is compatible with other granted locks.

 *

 * DLM_LKF_ORPHAN

 *

 * not yet implemented

 *

 * DLM_LKF_ALTPR

 *

 * If the requested mode cannot be granted immediately, try to grant the lock

 * in PR mode instead.  If this alternate mode is granted instead of the

 * requested mode, DLM_SBF_ALTMODE is returned in the lksb.

 *

 * DLM_LKF_ALTCW

 *

 * The same as ALTPR, but the alternate mode is CW.

 *

 * DLM_LKF_FORCEUNLOCK

 *

 * Unlock the lock even if it is converting or waiting or has sublocks.

 * Only really for use by the userland device.c code.

 *

 */

#define DLM_LKF_NOQUEUE         0x00000001

#define DLM_LKF_CANCEL          0x00000002

#define DLM_LKF_CONVERT         0x00000004

#define DLM_LKF_VALBLK          0x00000008

#define DLM_LKF_QUECVT          0x00000010

#define DLM_LKF_IVVALBLK        0x00000020

#define DLM_LKF_CONVDEADLK      0x00000040

#define DLM_LKF_PERSISTENT      0x00000080

#define DLM_LKF_NODLCKWT        0x00000100

#define DLM_LKF_NODLCKBLK       0x00000200

#define DLM_LKF_EXPEDITE        0x00000400

#define DLM_LKF_NOQUEUEBAST     0x00000800

#define DLM_LKF_HEADQUE         0x00001000

#define DLM_LKF_NOORDER         0x00002000

#define DLM_LKF_ORPHAN          0x00004000

#define DLM_LKF_ALTPR           0x00008000

#define DLM_LKF_ALTCW           0x00010000

#define DLM_LKF_FORCEUNLOCK     0x00020000

#define DLM_LKF_TIMEOUT         0x00040000

/*

 * Some return codes that are not in errno.h

 */

#define DLM_ECANCEL             0x10001

#define DLM_EUNLOCK             0x10002

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

 * -ENOMEM if there is no memory to process request

 * -EINVAL if there are invalid parameters

 * -DLM_EUNLOCK if unlock request was successful

 * -DLM_ECANCEL if a cancel completed successfully

 */

#define DLM_SBF_DEMOTED         0x01

#define DLM_SBF_VALNOTVALID     0x02

#define DLM_SBF_ALTMODE         0x04

struct dlm_lksb {

        int      sb_status;

        uint32_t sb_lkid;

        char     sb_flags;

        char *   sb_lvbptr;

};

#define DLM_LSFL_NODIR          0x00000001

#define DLM_LSFL_TIMEWARN       0x00000002

#define DLM_LSFL_FS             0x00000004

#ifdef __KERNEL__

/*

 * dlm_new_lockspace

 *

 * Starts a lockspace with the given name.  If the named lockspace exists in

 * the cluster, the calling node joins it.

 */

int dlm_new_lockspace(char *name, int namelen, dlm_lockspace_t **lockspace,

                      uint32_t flags, int lvblen);

/*

 * dlm_release_lockspace

 *

 * Stop a lockspace.

 */

int dlm_release_lockspace(dlm_lockspace_t *lockspace, int force);

/*

 * dlm_lock

 *

 * Make an asyncronous request to acquire or convert a lock on a named

 * resource.

 *

 * lockspace: context for the request

 * mode: the requested mode of the lock (DLM_LOCK_)

 * lksb: lock status block for input and async return values

 * flags: input flags (DLM_LKF_)

 * name: name of the resource to lock, can be binary

 * namelen: the length in bytes of the resource name (MAX_RESNAME_LEN)

 * parent: the lock ID of a parent lock or 0 if none

 * lockast: function DLM executes when it completes processing the request

 * astarg: argument passed to lockast and bast functions

 * bast: function DLM executes when this lock later blocks another request

 *

 * Returns:

 * 0 if request is successfully queued for processing

 * -EINVAL if any input parameters are invalid

 * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE

 * -ENOMEM if there is no memory to process request

 * -ENOTCONN if there is a communication error

 *

 * If the call to dlm_lock returns an error then the operation has failed and

 * the AST routine will not be called.  If dlm_lock returns 0 it is still

 * possible that the lock operation will fail. The AST routine will be called

 * when the locking is complete and the status is returned in the lksb.

 *

 * If the AST routines or parameter are passed to a conversion operation then

 * they will overwrite those values that were passed to a previous dlm_lock

 * call.

 *

 * AST routines should not block (at least not for long), but may make

 * any locking calls they please.

 */

int dlm_lock(dlm_lockspace_t *lockspace,

             int mode,

             struct dlm_lksb *lksb,

             uint32_t flags,

             void *name,

             unsigned int namelen,

             uint32_t parent_lkid,

             void (*lockast) (void *astarg),

             void *astarg,

             void (*bast) (void *astarg, int mode));

/*

 * dlm_unlock

 *

 * Asynchronously release a lock on a resource.  The AST routine is called

 * when the resource is successfully unlocked.

 *

 * lockspace: context for the request

 * lkid: the lock ID as returned in the lksb

 * flags: input flags (DLM_LKF_)

 * lksb: if NULL the lksb parameter passed to last lock request is used

 * astarg: the arg used with the completion ast for the unlock

 *

 * Returns:

 * 0 if request is successfully queued for processing

 * -EINVAL if any input parameters are invalid

 * -ENOTEMPTY if the lock still has sublocks

 * -EBUSY if the lock is waiting for a remote lock operation

 * -ENOTCONN if there is a communication error

 */

int dlm_unlock(dlm_lockspace_t *lockspace,

               uint32_t lkid,

               uint32_t flags,

               struct dlm_lksb *lksb,

               void *astarg);

#endif                          /* __KERNEL__ */

#endif                          /* __DLM_DOT_H__ */