/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 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 version 2.
*/
#ifndef __LM_INTERFACE_DOT_H__
#define __LM_INTERFACE_DOT_H__
/*
* Opaque handles represent the lock module's lockspace structure, the lock
* module's lock structures, and GFS's file system (superblock) structure.
*/
typedef void lm_lockspace_t;
typedef void lm_lock_t;
struct gfs2_sbd;
typedef void (*lm_callback_t) (struct gfs2_sbd *sdp, unsigned int type, void *data);
/*
* lm_mount() flags
*
* LM_MFLAG_SPECTATOR
* GFS is asking to join the filesystem's lockspace, but it doesn't want to
* modify the filesystem. The lock module shouldn't assign a journal to the FS
* mount. It shouldn't send recovery callbacks to the FS mount. If the node
* dies or withdraws, all locks can be wiped immediately.
*/
#define LM_MFLAG_SPECTATOR 0x00000001
/*
* lm_lockstruct flags
*
* LM_LSFLAG_LOCAL
* The lock_nolock module returns LM_LSFLAG_LOCAL to GFS, indicating that GFS
* can make single-node optimizations.
*/
#define LM_LSFLAG_LOCAL 0x00000001
/*
* lm_lockname types
*/
#define LM_TYPE_RESERVED 0x00
#define LM_TYPE_NONDISK 0x01
#define LM_TYPE_INODE 0x02
#define LM_TYPE_RGRP 0x03
#define LM_TYPE_META 0x04
#define LM_TYPE_IOPEN 0x05
#define LM_TYPE_FLOCK 0x06
#define LM_TYPE_PLOCK 0x07
#define LM_TYPE_QUOTA 0x08
#define LM_TYPE_JOURNAL 0x09
/*
* lm_lock() states
*
* SHARED is compatible with SHARED, not with DEFERRED or EX.
* DEFERRED is compatible with DEFERRED, not with SHARED or EX.
*/
#define LM_ST_UNLOCKED 0
#define LM_ST_EXCLUSIVE 1
#define LM_ST_DEFERRED 2
#define LM_ST_SHARED 3
/*
* lm_lock() flags
*
* LM_FLAG_TRY
* Don't wait to acquire the lock if it can't be granted immediately.
*
* LM_FLAG_TRY_1CB
* Send one blocking callback if TRY is set and the lock is not granted.
*
* LM_FLAG_NOEXP
* GFS sets this flag on lock requests it makes while doing journal recovery.
* These special requests should not be blocked due to the recovery like
* ordinary locks would be.
*
* LM_FLAG_ANY
* A SHARED request may also be granted in DEFERRED, or a DEFERRED request may
* also be granted in SHARED. The preferred state is whichever is compatible
* with other granted locks, or the specified state if no other locks exist.
*
* LM_FLAG_PRIORITY
* Override fairness considerations. Suppose a lock is held in a shared state
* and there is a pending request for the deferred state. A shared lock
* request with the priority flag would be allowed to bypass the deferred
* request and directly join the other shared lock. A shared lock request
* without the priority flag might be forced to wait until the deferred
* requested had acquired and released the lock.
*/
#define LM_FLAG_TRY 0x00000001
#define LM_FLAG_TRY_1CB 0x00000002
#define LM_FLAG_NOEXP 0x00000004
#define LM_FLAG_ANY 0x00000008
#define LM_FLAG_PRIORITY 0x00000010
/*
* lm_lock() and lm_async_cb return flags
*
* LM_OUT_ST_MASK
* Masks the lower two bits of lock state in the returned value.
*
* LM_OUT_CACHEABLE
* The lock hasn't been released so GFS can continue to cache data for it.
*
* LM_OUT_CANCELED
* The lock request was canceled.
*
* LM_OUT_ASYNC
* The result of the request will be returned in an LM_CB_ASYNC callback.
*/
#define LM_OUT_ST_MASK 0x00000003
#define LM_OUT_CACHEABLE 0x00000004
#define LM_OUT_CANCELED 0x00000008
#define LM_OUT_ASYNC 0x00000080
#define LM_OUT_ERROR 0x00000100
/*
* lm_callback_t types
*
* LM_CB_NEED_E LM_CB_NEED_D LM_CB_NEED_S
* Blocking callback, a remote node is requesting the given lock in
* EXCLUSIVE, DEFERRED, or SHARED.
*
* LM_CB_NEED_RECOVERY
* The given journal needs to be recovered.
*
* LM_CB_DROPLOCKS
* Reduce the number of cached locks.
*
* LM_CB_ASYNC
* The given lock has been granted.
*/
#define LM_CB_NEED_E 257
#define LM_CB_NEED_D 258
#define LM_CB_NEED_S 259
#define LM_CB_NEED_RECOVERY 260
#define LM_CB_DROPLOCKS 261
#define LM_CB_ASYNC 262
/*
* lm_recovery_done() messages
*/
#define LM_RD_GAVEUP 308
#define LM_RD_SUCCESS 309
struct lm_lockname {
u64 ln_number;
unsigned int ln_type;
};
#define lm_name_equal(name1, name2) \
(((name1)->ln_number == (name2)->ln_number) && \
((name1)->ln_type == (name2)->ln_type)) \
struct lm_async_cb {
struct lm_lockname lc_name;
int lc_ret;
};
struct lm_lockstruct;
struct lm_lockops {
char lm_proto_name[256];
/*
* Mount/Unmount
*/
int (*lm_mount) (char *table_name, char *host_data,
lm_callback_t cb, struct gfs2_sbd *sdp,
unsigned int min_lvb_size, int flags,
struct lm_lockstruct *lockstruct,
struct kobject *fskobj);
void (*lm_others_may_mount) (lm_lockspace_t *lockspace);
void (*lm_unmount) (lm_lockspace_t *lockspace);
void (*lm_withdraw) (lm_lockspace_t *lockspace);
/*
* Lock oriented operations
*/
int (*lm_get_lock) (lm_lockspace_t *lockspace,
struct lm_lockname *name, lm_lock_t **lockp);
void (*lm_put_lock) (lm_lock_t *lock);
unsigned int (*lm_lock) (lm_lock_t *lock, unsigned int cur_state,
unsigned int req_state, unsigned int flags);
unsigned int (*lm_unlock) (lm_lock_t *lock, unsigned int cur_state);
void (*lm_cancel) (lm_lock_t *lock);
int (*lm_hold_lvb) (lm_lock_t *lock, char **lvbp);
void (*lm_unhold_lvb) (lm_lock_t *lock, char *lvb);
void (*lm_sync_lvb) (lm_lock_t *lock, char *lvb);
/*
* Posix Lock oriented operations
*/
int (*lm_plock_get) (lm_lockspace_t *lockspace,
struct lm_lockname *name,
struct file *file, struct file_lock *fl);
int (*lm_plock) (lm_lockspace_t *lockspace,
struct lm_lockname *name,
struct file *file, int cmd, struct file_lock *fl);
int (*lm_punlock) (lm_lockspace_t *lockspace,
struct lm_lockname *name,
struct file *file, struct file_lock *fl);
/*
* Client oriented operations
*/
void (*lm_recovery_done) (lm_lockspace_t *lockspace, unsigned int jid,
unsigned int message);
struct module *lm_owner;
};
/*
* lm_mount() return values
*
* ls_jid - the journal ID this node should use
* ls_first - this node is the first to mount the file system
* ls_lvb_size - size in bytes of lock value blocks
* ls_lockspace - lock module's context for this file system
* ls_ops - lock module's functions
* ls_flags - lock module features
*/
struct lm_lockstruct {
unsigned int ls_jid;
unsigned int ls_first;
unsigned int ls_lvb_size;
lm_lockspace_t *ls_lockspace;
struct lm_lockops *ls_ops;
int ls_flags;
};
/*
* Lock module bottom interface. A lock module makes itself available to GFS
* with these functions.
*/
int gfs2_register_lockproto(struct lm_lockops *proto);
void gfs2_unregister_lockproto(struct lm_lockops *proto);
/*
* Lock module top interface. GFS calls these functions when mounting or
* unmounting a file system.
*/
int gfs2_mount_lockproto(char *proto_name, char *table_name, char *host_data,
lm_callback_t cb, struct gfs2_sbd *sdp,
unsigned int min_lvb_size, int flags,
struct lm_lockstruct *lockstruct,
struct kobject *fskobj);
void gfs2_unmount_lockproto(struct lm_lockstruct *lockstruct);
void gfs2_withdraw_lockproto(struct lm_lockstruct *lockstruct);
#endif /* __LM_INTERFACE_DOT_H__ */
