kernel-ark/include/linux/lm_interface.h
Benjamin Marzinski 58e9fee13e [GFS2] Invalidate cache at correct point
GFS2 wasn't invalidating its cache before it called into the lock manager
with a request that could potentially drop a lock.  This was leaving a
window where the lock could be actually be held by another node, but the
file's page cache would still appear valid, causing coherency problems.
This patch moves the cache invalidation to before the lock manager call
when dropping a lock. It also adds the option to the lock_dlm lock
manager to not use conversion mode deadlock avoidance, which, on a
conversion from shared to exclusive, could internally drop the lock, and
then reacquire in. GFS2 now asks lock_dlm to not do this.  Instead, GFS2
manually drops the lock and reacquires it.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:41:44 +01:00

284 lines
7.3 KiB
C

/*
* 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__
typedef void (*lm_callback_t) (void *ptr, 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.
*
* LM_MFLAG_CONV_NODROP
* Do not allow the dlm to internally resolve conversion deadlocks by demoting
* the lock to unlocked and then reacquiring it in the requested mode. Instead,
* it should cancel the request and return LM_OUT_CONV_DEADLK.
*/
#define LM_MFLAG_SPECTATOR 0x00000001
#define LM_MFLAG_CONV_NODROP 0x00000002
/*
* 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.
*
* LM_OUT_CONV_DEADLK
* The lock request was canceled do to a conversion deadlock.
*/
#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
#define LM_OUT_CONV_DEADLK 0x00000200
/*
* 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 {
const char *lm_proto_name;
/*
* Mount/Unmount
*/
int (*lm_mount) (char *table_name, char *host_data,
lm_callback_t cb, void *cb_data,
unsigned int min_lvb_size, int flags,
struct lm_lockstruct *lockstruct,
struct kobject *fskobj);
void (*lm_others_may_mount) (void *lockspace);
void (*lm_unmount) (void *lockspace);
void (*lm_withdraw) (void *lockspace);
/*
* Lock oriented operations
*/
int (*lm_get_lock) (void *lockspace, struct lm_lockname *name, void **lockp);
void (*lm_put_lock) (void *lock);
unsigned int (*lm_lock) (void *lock, unsigned int cur_state,
unsigned int req_state, unsigned int flags);
unsigned int (*lm_unlock) (void *lock, unsigned int cur_state);
void (*lm_cancel) (void *lock);
int (*lm_hold_lvb) (void *lock, char **lvbp);
void (*lm_unhold_lvb) (void *lock, char *lvb);
/*
* Posix Lock oriented operations
*/
int (*lm_plock_get) (void *lockspace, struct lm_lockname *name,
struct file *file, struct file_lock *fl);
int (*lm_plock) (void *lockspace, struct lm_lockname *name,
struct file *file, int cmd, struct file_lock *fl);
int (*lm_punlock) (void *lockspace, struct lm_lockname *name,
struct file *file, struct file_lock *fl);
/*
* Client oriented operations
*/
void (*lm_recovery_done) (void *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;
void *ls_lockspace;
const 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(const struct lm_lockops *proto);
void gfs2_unregister_lockproto(const 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, void *cb_data,
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__ */