David Teigland | b3b94fa | 2006-01-16 16:50:04 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. |
Steven Whitehouse | 3a8a9a1 | 2006-05-18 15:09:15 -0400 | [diff] [blame] | 3 | * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. |
David Teigland | b3b94fa | 2006-01-16 16:50:04 +0000 | [diff] [blame] | 4 | * |
| 5 | * This copyrighted material is made available to anyone wishing to use, |
| 6 | * modify, copy, or redistribute it subject to the terms and conditions |
| 7 | * of the GNU General Public License v.2. |
| 8 | */ |
| 9 | |
| 10 | #ifndef __LM_INTERFACE_DOT_H__ |
| 11 | #define __LM_INTERFACE_DOT_H__ |
| 12 | |
| 13 | /* |
| 14 | * Opaque handles represent the lock module's lockspace structure, the lock |
| 15 | * module's lock structures, and GFS's file system (superblock) structure. |
| 16 | */ |
| 17 | |
| 18 | typedef void lm_lockspace_t; |
| 19 | typedef void lm_lock_t; |
| 20 | typedef void lm_fsdata_t; |
| 21 | |
| 22 | typedef void (*lm_callback_t) (lm_fsdata_t *fsdata, unsigned int type, |
| 23 | void *data); |
| 24 | |
| 25 | /* |
| 26 | * lm_mount() flags |
| 27 | * |
| 28 | * LM_MFLAG_SPECTATOR |
| 29 | * GFS is asking to join the filesystem's lockspace, but it doesn't want to |
| 30 | * modify the filesystem. The lock module shouldn't assign a journal to the FS |
| 31 | * mount. It shouldn't send recovery callbacks to the FS mount. If the node |
| 32 | * dies or withdraws, all locks can be wiped immediately. |
| 33 | */ |
| 34 | |
| 35 | #define LM_MFLAG_SPECTATOR 0x00000001 |
| 36 | |
| 37 | /* |
| 38 | * lm_lockstruct flags |
| 39 | * |
| 40 | * LM_LSFLAG_LOCAL |
| 41 | * The lock_nolock module returns LM_LSFLAG_LOCAL to GFS, indicating that GFS |
| 42 | * can make single-node optimizations. |
| 43 | */ |
| 44 | |
| 45 | #define LM_LSFLAG_LOCAL 0x00000001 |
| 46 | |
| 47 | /* |
| 48 | * lm_lockname types |
| 49 | */ |
| 50 | |
| 51 | #define LM_TYPE_RESERVED 0x00 |
| 52 | #define LM_TYPE_NONDISK 0x01 |
| 53 | #define LM_TYPE_INODE 0x02 |
| 54 | #define LM_TYPE_RGRP 0x03 |
| 55 | #define LM_TYPE_META 0x04 |
| 56 | #define LM_TYPE_IOPEN 0x05 |
| 57 | #define LM_TYPE_FLOCK 0x06 |
| 58 | #define LM_TYPE_PLOCK 0x07 |
| 59 | #define LM_TYPE_QUOTA 0x08 |
| 60 | #define LM_TYPE_JOURNAL 0x09 |
| 61 | |
| 62 | /* |
| 63 | * lm_lock() states |
| 64 | * |
| 65 | * SHARED is compatible with SHARED, not with DEFERRED or EX. |
| 66 | * DEFERRED is compatible with DEFERRED, not with SHARED or EX. |
| 67 | */ |
| 68 | |
| 69 | #define LM_ST_UNLOCKED 0 |
| 70 | #define LM_ST_EXCLUSIVE 1 |
| 71 | #define LM_ST_DEFERRED 2 |
| 72 | #define LM_ST_SHARED 3 |
| 73 | |
| 74 | /* |
| 75 | * lm_lock() flags |
| 76 | * |
| 77 | * LM_FLAG_TRY |
| 78 | * Don't wait to acquire the lock if it can't be granted immediately. |
| 79 | * |
| 80 | * LM_FLAG_TRY_1CB |
| 81 | * Send one blocking callback if TRY is set and the lock is not granted. |
| 82 | * |
| 83 | * LM_FLAG_NOEXP |
| 84 | * GFS sets this flag on lock requests it makes while doing journal recovery. |
| 85 | * These special requests should not be blocked due to the recovery like |
| 86 | * ordinary locks would be. |
| 87 | * |
| 88 | * LM_FLAG_ANY |
| 89 | * A SHARED request may also be granted in DEFERRED, or a DEFERRED request may |
| 90 | * also be granted in SHARED. The preferred state is whichever is compatible |
| 91 | * with other granted locks, or the specified state if no other locks exist. |
| 92 | * |
| 93 | * LM_FLAG_PRIORITY |
| 94 | * Override fairness considerations. Suppose a lock is held in a shared state |
| 95 | * and there is a pending request for the deferred state. A shared lock |
| 96 | * request with the priority flag would be allowed to bypass the deferred |
| 97 | * request and directly join the other shared lock. A shared lock request |
| 98 | * without the priority flag might be forced to wait until the deferred |
| 99 | * requested had acquired and released the lock. |
| 100 | */ |
| 101 | |
| 102 | #define LM_FLAG_TRY 0x00000001 |
| 103 | #define LM_FLAG_TRY_1CB 0x00000002 |
| 104 | #define LM_FLAG_NOEXP 0x00000004 |
| 105 | #define LM_FLAG_ANY 0x00000008 |
| 106 | #define LM_FLAG_PRIORITY 0x00000010 |
| 107 | |
| 108 | /* |
| 109 | * lm_lock() and lm_async_cb return flags |
| 110 | * |
| 111 | * LM_OUT_ST_MASK |
| 112 | * Masks the lower two bits of lock state in the returned value. |
| 113 | * |
| 114 | * LM_OUT_CACHEABLE |
| 115 | * The lock hasn't been released so GFS can continue to cache data for it. |
| 116 | * |
| 117 | * LM_OUT_CANCELED |
| 118 | * The lock request was canceled. |
| 119 | * |
| 120 | * LM_OUT_ASYNC |
| 121 | * The result of the request will be returned in an LM_CB_ASYNC callback. |
| 122 | */ |
| 123 | |
| 124 | #define LM_OUT_ST_MASK 0x00000003 |
| 125 | #define LM_OUT_CACHEABLE 0x00000004 |
| 126 | #define LM_OUT_CANCELED 0x00000008 |
| 127 | #define LM_OUT_ASYNC 0x00000080 |
| 128 | #define LM_OUT_ERROR 0x00000100 |
| 129 | |
| 130 | /* |
| 131 | * lm_callback_t types |
| 132 | * |
| 133 | * LM_CB_NEED_E LM_CB_NEED_D LM_CB_NEED_S |
| 134 | * Blocking callback, a remote node is requesting the given lock in |
| 135 | * EXCLUSIVE, DEFERRED, or SHARED. |
| 136 | * |
| 137 | * LM_CB_NEED_RECOVERY |
| 138 | * The given journal needs to be recovered. |
| 139 | * |
| 140 | * LM_CB_DROPLOCKS |
| 141 | * Reduce the number of cached locks. |
| 142 | * |
| 143 | * LM_CB_ASYNC |
| 144 | * The given lock has been granted. |
| 145 | */ |
| 146 | |
| 147 | #define LM_CB_NEED_E 257 |
| 148 | #define LM_CB_NEED_D 258 |
| 149 | #define LM_CB_NEED_S 259 |
| 150 | #define LM_CB_NEED_RECOVERY 260 |
| 151 | #define LM_CB_DROPLOCKS 261 |
| 152 | #define LM_CB_ASYNC 262 |
| 153 | |
| 154 | /* |
| 155 | * lm_recovery_done() messages |
| 156 | */ |
| 157 | |
| 158 | #define LM_RD_GAVEUP 308 |
| 159 | #define LM_RD_SUCCESS 309 |
| 160 | |
| 161 | |
| 162 | struct lm_lockname { |
| 163 | uint64_t ln_number; |
| 164 | unsigned int ln_type; |
| 165 | }; |
| 166 | |
| 167 | #define lm_name_equal(name1, name2) \ |
| 168 | (((name1)->ln_number == (name2)->ln_number) && \ |
| 169 | ((name1)->ln_type == (name2)->ln_type)) \ |
| 170 | |
| 171 | struct lm_async_cb { |
| 172 | struct lm_lockname lc_name; |
| 173 | int lc_ret; |
| 174 | }; |
| 175 | |
| 176 | struct lm_lockstruct; |
| 177 | |
| 178 | struct lm_lockops { |
| 179 | char lm_proto_name[256]; |
| 180 | |
| 181 | /* |
| 182 | * Mount/Unmount |
| 183 | */ |
| 184 | |
| 185 | int (*lm_mount) (char *table_name, char *host_data, |
| 186 | lm_callback_t cb, lm_fsdata_t *fsdata, |
| 187 | unsigned int min_lvb_size, int flags, |
| 188 | struct lm_lockstruct *lockstruct, |
| 189 | struct kobject *fskobj); |
| 190 | |
| 191 | void (*lm_others_may_mount) (lm_lockspace_t *lockspace); |
| 192 | |
| 193 | void (*lm_unmount) (lm_lockspace_t *lockspace); |
| 194 | |
| 195 | void (*lm_withdraw) (lm_lockspace_t *lockspace); |
| 196 | |
| 197 | /* |
| 198 | * Lock oriented operations |
| 199 | */ |
| 200 | |
| 201 | int (*lm_get_lock) (lm_lockspace_t *lockspace, |
| 202 | struct lm_lockname *name, lm_lock_t **lockp); |
| 203 | |
| 204 | void (*lm_put_lock) (lm_lock_t *lock); |
| 205 | |
| 206 | unsigned int (*lm_lock) (lm_lock_t *lock, unsigned int cur_state, |
| 207 | unsigned int req_state, unsigned int flags); |
| 208 | |
| 209 | unsigned int (*lm_unlock) (lm_lock_t *lock, unsigned int cur_state); |
| 210 | |
| 211 | void (*lm_cancel) (lm_lock_t *lock); |
| 212 | |
| 213 | int (*lm_hold_lvb) (lm_lock_t *lock, char **lvbp); |
| 214 | void (*lm_unhold_lvb) (lm_lock_t *lock, char *lvb); |
| 215 | void (*lm_sync_lvb) (lm_lock_t *lock, char *lvb); |
| 216 | |
| 217 | /* |
| 218 | * Posix Lock oriented operations |
| 219 | */ |
| 220 | |
| 221 | int (*lm_plock_get) (lm_lockspace_t *lockspace, |
| 222 | struct lm_lockname *name, |
| 223 | struct file *file, struct file_lock *fl); |
| 224 | |
| 225 | int (*lm_plock) (lm_lockspace_t *lockspace, |
| 226 | struct lm_lockname *name, |
| 227 | struct file *file, int cmd, struct file_lock *fl); |
| 228 | |
| 229 | int (*lm_punlock) (lm_lockspace_t *lockspace, |
| 230 | struct lm_lockname *name, |
| 231 | struct file *file, struct file_lock *fl); |
| 232 | |
| 233 | /* |
| 234 | * Client oriented operations |
| 235 | */ |
| 236 | |
| 237 | void (*lm_recovery_done) (lm_lockspace_t *lockspace, unsigned int jid, |
| 238 | unsigned int message); |
| 239 | |
| 240 | struct module *lm_owner; |
| 241 | }; |
| 242 | |
| 243 | /* |
| 244 | * lm_mount() return values |
| 245 | * |
| 246 | * ls_jid - the journal ID this node should use |
| 247 | * ls_first - this node is the first to mount the file system |
| 248 | * ls_lvb_size - size in bytes of lock value blocks |
| 249 | * ls_lockspace - lock module's context for this file system |
| 250 | * ls_ops - lock module's functions |
| 251 | * ls_flags - lock module features |
| 252 | */ |
| 253 | |
| 254 | struct lm_lockstruct { |
| 255 | unsigned int ls_jid; |
| 256 | unsigned int ls_first; |
| 257 | unsigned int ls_lvb_size; |
| 258 | lm_lockspace_t *ls_lockspace; |
| 259 | struct lm_lockops *ls_ops; |
| 260 | int ls_flags; |
| 261 | }; |
| 262 | |
| 263 | void __init gfs2_init_lmh(void); |
| 264 | |
| 265 | /* |
| 266 | * Lock module bottom interface. A lock module makes itself available to GFS |
| 267 | * with these functions. |
| 268 | * |
| 269 | * For the time being, we copy the gfs1 lock module bottom interface so the |
| 270 | * same lock modules can be used with both gfs1 and gfs2 (it won't be possible |
| 271 | * to load both gfs1 and gfs2 at once.) Eventually the lock modules will fork |
| 272 | * for gfs1/gfs2 and this API can change to the gfs2_ prefix. |
| 273 | */ |
| 274 | |
| 275 | int gfs_register_lockproto(struct lm_lockops *proto); |
| 276 | |
| 277 | void gfs_unregister_lockproto(struct lm_lockops *proto); |
| 278 | |
| 279 | /* |
| 280 | * Lock module top interface. GFS calls these functions when mounting or |
| 281 | * unmounting a file system. |
| 282 | */ |
| 283 | |
| 284 | int gfs2_mount_lockproto(char *proto_name, char *table_name, char *host_data, |
| 285 | lm_callback_t cb, lm_fsdata_t *fsdata, |
| 286 | unsigned int min_lvb_size, int flags, |
| 287 | struct lm_lockstruct *lockstruct, |
| 288 | struct kobject *fskobj); |
| 289 | |
| 290 | void gfs2_unmount_lockproto(struct lm_lockstruct *lockstruct); |
| 291 | |
| 292 | void gfs2_withdraw_lockproto(struct lm_lockstruct *lockstruct); |
| 293 | |
| 294 | #endif /* __LM_INTERFACE_DOT_H__ */ |
| 295 | |