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Diffstat (limited to 'fs/gfs2/lm_interface.h')
| -rw-r--r-- | fs/gfs2/lm_interface.h | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/fs/gfs2/lm_interface.h b/fs/gfs2/lm_interface.h new file mode 100644 index 000000000000..378432f17f27 --- /dev/null +++ b/fs/gfs2/lm_interface.h @@ -0,0 +1,295 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2005 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 __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; +typedef void lm_fsdata_t; + +typedef void (*lm_callback_t) (lm_fsdata_t *fsdata, 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 { + uint64_t 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, lm_fsdata_t *fsdata, + 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; +}; + +void __init gfs2_init_lmh(void); + +/* + * Lock module bottom interface. A lock module makes itself available to GFS + * with these functions. + * + * For the time being, we copy the gfs1 lock module bottom interface so the + * same lock modules can be used with both gfs1 and gfs2 (it won't be possible + * to load both gfs1 and gfs2 at once.) Eventually the lock modules will fork + * for gfs1/gfs2 and this API can change to the gfs2_ prefix. + */ + +int gfs_register_lockproto(struct lm_lockops *proto); + +void gfs_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, lm_fsdata_t *fsdata, + 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__ */ + |
