/******************************************************************************
*******************************************************************************
**
** 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 __DLM_DOT_H__
#define __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_NODIR 0x00000001
#define DLM_LSFL_TIMEWARN 0x00000002
#define DLM_LSFL_FS 0x00000004
#define DLM_LSFL_NEWEXCL 0x00000008
#ifdef __KERNEL__
struct dlm_slot {
int nodeid; /* 1 to MAX_INT */
int slot; /* 1 to MAX_INT */
};
/*
* recover_prep: called before the dlm begins lock recovery.
* Notfies lockspace user that locks from failed members will be granted.
* recover_slot: called after recover_prep and before recover_done.
* Identifies a failed lockspace member.
* recover_done: called after the dlm completes lock recovery.
* Identifies lockspace members and lockspace generation number.
*/
struct dlm_lockspace_ops {
void (*recover_prep) (void *ops_arg);
void (*recover_slot) (void *ops_arg, struct dlm_slot *slot);
void (*recover_done) (void *ops_arg, struct dlm_slot *slots,
int num_slots, int our_slot, uint32_t generation);
};
/*
* dlm_new_lockspace
*
* Create/join a lockspace.
*
* name: lockspace name, null terminated, up to DLM_LOCKSPACE_LEN (not
* including terminating null).
*
* cluster: cluster name, null terminated, up to DLM_LOCKSPACE_LEN (not
* including terminating null). Optional. When cluster is null, it
* is not used. When set, dlm_new_lockspace() returns -EBADR if cluster
* is not equal to the dlm cluster name.
*
* flags:
* DLM_LSFL_NODIR
* The dlm should not use a resource directory, but statically assign
* resource mastery to nodes based on the name hash that is otherwise
* used to select the directory node. Must be the same on all nodes.
* DLM_LSFL_TIMEWARN
* The dlm should emit netlink messages if locks have been waiting
* for a configurable amount of time. (Unused.)
* DLM_LSFL_FS
* The lockspace user is in the kernel (i.e. filesystem). Enables
* direct bast/cast callbacks.
* DLM_LSFL_NEWEXCL
* dlm_new_lockspace() should return -EEXIST if the lockspace exists.
*
* lvblen: length of lvb in bytes. Must be multiple of 8.
* dlm_new_lockspace() returns an error if this does not match
* what other nodes are using.
*
* ops: callbacks that indicate lockspace recovery points so the
* caller can coordinate its recovery and know lockspace members.
* This is only used by the initial dlm_new_lockspace() call.
* Optional.
*
* ops_arg: arg for ops callbacks.
*
* ops_result: tells caller if the ops callbacks (if provided) will
* be used or not. 0: will be used, -EXXX will not be used.
* -EOPNOTSUPP: the dlm does not have recovery_callbacks enabled.
*
* lockspace: handle for dlm functions
*/
int dlm_new_lockspace(const char *name, const char *cluster,
uint32_t flags, int lvblen,
const struct dlm_lockspace_ops *ops, void *ops_arg,
int *ops_result, dlm_lockspace_t **lockspace);
/*
* 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__ */
