lm_interface.h 6.9 KB

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  1. /*
  2. * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
  3. * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
  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 version 2.
  8. */
  9. #ifndef __LM_INTERFACE_DOT_H__
  10. #define __LM_INTERFACE_DOT_H__
  11. typedef void (*lm_callback_t) (void *ptr, unsigned int type, void *data);
  12. /*
  13. * lm_mount() flags
  14. *
  15. * LM_MFLAG_SPECTATOR
  16. * GFS is asking to join the filesystem's lockspace, but it doesn't want to
  17. * modify the filesystem. The lock module shouldn't assign a journal to the FS
  18. * mount. It shouldn't send recovery callbacks to the FS mount. If the node
  19. * dies or withdraws, all locks can be wiped immediately.
  20. */
  21. #define LM_MFLAG_SPECTATOR 0x00000001
  22. /*
  23. * lm_lockstruct flags
  24. *
  25. * LM_LSFLAG_LOCAL
  26. * The lock_nolock module returns LM_LSFLAG_LOCAL to GFS, indicating that GFS
  27. * can make single-node optimizations.
  28. */
  29. #define LM_LSFLAG_LOCAL 0x00000001
  30. /*
  31. * lm_lockname types
  32. */
  33. #define LM_TYPE_RESERVED 0x00
  34. #define LM_TYPE_NONDISK 0x01
  35. #define LM_TYPE_INODE 0x02
  36. #define LM_TYPE_RGRP 0x03
  37. #define LM_TYPE_META 0x04
  38. #define LM_TYPE_IOPEN 0x05
  39. #define LM_TYPE_FLOCK 0x06
  40. #define LM_TYPE_PLOCK 0x07
  41. #define LM_TYPE_QUOTA 0x08
  42. #define LM_TYPE_JOURNAL 0x09
  43. /*
  44. * lm_lock() states
  45. *
  46. * SHARED is compatible with SHARED, not with DEFERRED or EX.
  47. * DEFERRED is compatible with DEFERRED, not with SHARED or EX.
  48. */
  49. #define LM_ST_UNLOCKED 0
  50. #define LM_ST_EXCLUSIVE 1
  51. #define LM_ST_DEFERRED 2
  52. #define LM_ST_SHARED 3
  53. /*
  54. * lm_lock() flags
  55. *
  56. * LM_FLAG_TRY
  57. * Don't wait to acquire the lock if it can't be granted immediately.
  58. *
  59. * LM_FLAG_TRY_1CB
  60. * Send one blocking callback if TRY is set and the lock is not granted.
  61. *
  62. * LM_FLAG_NOEXP
  63. * GFS sets this flag on lock requests it makes while doing journal recovery.
  64. * These special requests should not be blocked due to the recovery like
  65. * ordinary locks would be.
  66. *
  67. * LM_FLAG_ANY
  68. * A SHARED request may also be granted in DEFERRED, or a DEFERRED request may
  69. * also be granted in SHARED. The preferred state is whichever is compatible
  70. * with other granted locks, or the specified state if no other locks exist.
  71. *
  72. * LM_FLAG_PRIORITY
  73. * Override fairness considerations. Suppose a lock is held in a shared state
  74. * and there is a pending request for the deferred state. A shared lock
  75. * request with the priority flag would be allowed to bypass the deferred
  76. * request and directly join the other shared lock. A shared lock request
  77. * without the priority flag might be forced to wait until the deferred
  78. * requested had acquired and released the lock.
  79. */
  80. #define LM_FLAG_TRY 0x00000001
  81. #define LM_FLAG_TRY_1CB 0x00000002
  82. #define LM_FLAG_NOEXP 0x00000004
  83. #define LM_FLAG_ANY 0x00000008
  84. #define LM_FLAG_PRIORITY 0x00000010
  85. /*
  86. * lm_lock() and lm_async_cb return flags
  87. *
  88. * LM_OUT_ST_MASK
  89. * Masks the lower two bits of lock state in the returned value.
  90. *
  91. * LM_OUT_CACHEABLE
  92. * The lock hasn't been released so GFS can continue to cache data for it.
  93. *
  94. * LM_OUT_CANCELED
  95. * The lock request was canceled.
  96. *
  97. * LM_OUT_ASYNC
  98. * The result of the request will be returned in an LM_CB_ASYNC callback.
  99. */
  100. #define LM_OUT_ST_MASK 0x00000003
  101. #define LM_OUT_CACHEABLE 0x00000004
  102. #define LM_OUT_CANCELED 0x00000008
  103. #define LM_OUT_ASYNC 0x00000080
  104. #define LM_OUT_ERROR 0x00000100
  105. /*
  106. * lm_callback_t types
  107. *
  108. * LM_CB_NEED_E LM_CB_NEED_D LM_CB_NEED_S
  109. * Blocking callback, a remote node is requesting the given lock in
  110. * EXCLUSIVE, DEFERRED, or SHARED.
  111. *
  112. * LM_CB_NEED_RECOVERY
  113. * The given journal needs to be recovered.
  114. *
  115. * LM_CB_DROPLOCKS
  116. * Reduce the number of cached locks.
  117. *
  118. * LM_CB_ASYNC
  119. * The given lock has been granted.
  120. */
  121. #define LM_CB_NEED_E 257
  122. #define LM_CB_NEED_D 258
  123. #define LM_CB_NEED_S 259
  124. #define LM_CB_NEED_RECOVERY 260
  125. #define LM_CB_DROPLOCKS 261
  126. #define LM_CB_ASYNC 262
  127. /*
  128. * lm_recovery_done() messages
  129. */
  130. #define LM_RD_GAVEUP 308
  131. #define LM_RD_SUCCESS 309
  132. struct lm_lockname {
  133. u64 ln_number;
  134. unsigned int ln_type;
  135. };
  136. #define lm_name_equal(name1, name2) \
  137. (((name1)->ln_number == (name2)->ln_number) && \
  138. ((name1)->ln_type == (name2)->ln_type)) \
  139. struct lm_async_cb {
  140. struct lm_lockname lc_name;
  141. int lc_ret;
  142. };
  143. struct lm_lockstruct;
  144. struct lm_lockops {
  145. const char *lm_proto_name;
  146. /*
  147. * Mount/Unmount
  148. */
  149. int (*lm_mount) (char *table_name, char *host_data,
  150. lm_callback_t cb, void *cb_data,
  151. unsigned int min_lvb_size, int flags,
  152. struct lm_lockstruct *lockstruct,
  153. struct kobject *fskobj);
  154. void (*lm_others_may_mount) (void *lockspace);
  155. void (*lm_unmount) (void *lockspace);
  156. void (*lm_withdraw) (void *lockspace);
  157. /*
  158. * Lock oriented operations
  159. */
  160. int (*lm_get_lock) (void *lockspace, struct lm_lockname *name, void **lockp);
  161. void (*lm_put_lock) (void *lock);
  162. unsigned int (*lm_lock) (void *lock, unsigned int cur_state,
  163. unsigned int req_state, unsigned int flags);
  164. unsigned int (*lm_unlock) (void *lock, unsigned int cur_state);
  165. void (*lm_cancel) (void *lock);
  166. int (*lm_hold_lvb) (void *lock, char **lvbp);
  167. void (*lm_unhold_lvb) (void *lock, char *lvb);
  168. /*
  169. * Posix Lock oriented operations
  170. */
  171. int (*lm_plock_get) (void *lockspace, struct lm_lockname *name,
  172. struct file *file, struct file_lock *fl);
  173. int (*lm_plock) (void *lockspace, struct lm_lockname *name,
  174. struct file *file, int cmd, struct file_lock *fl);
  175. int (*lm_punlock) (void *lockspace, struct lm_lockname *name,
  176. struct file *file, struct file_lock *fl);
  177. /*
  178. * Client oriented operations
  179. */
  180. void (*lm_recovery_done) (void *lockspace, unsigned int jid,
  181. unsigned int message);
  182. struct module *lm_owner;
  183. };
  184. /*
  185. * lm_mount() return values
  186. *
  187. * ls_jid - the journal ID this node should use
  188. * ls_first - this node is the first to mount the file system
  189. * ls_lvb_size - size in bytes of lock value blocks
  190. * ls_lockspace - lock module's context for this file system
  191. * ls_ops - lock module's functions
  192. * ls_flags - lock module features
  193. */
  194. struct lm_lockstruct {
  195. unsigned int ls_jid;
  196. unsigned int ls_first;
  197. unsigned int ls_lvb_size;
  198. void *ls_lockspace;
  199. const struct lm_lockops *ls_ops;
  200. int ls_flags;
  201. };
  202. /*
  203. * Lock module bottom interface. A lock module makes itself available to GFS
  204. * with these functions.
  205. */
  206. int gfs2_register_lockproto(const struct lm_lockops *proto);
  207. void gfs2_unregister_lockproto(const struct lm_lockops *proto);
  208. /*
  209. * Lock module top interface. GFS calls these functions when mounting or
  210. * unmounting a file system.
  211. */
  212. int gfs2_mount_lockproto(char *proto_name, char *table_name, char *host_data,
  213. lm_callback_t cb, void *cb_data,
  214. unsigned int min_lvb_size, int flags,
  215. struct lm_lockstruct *lockstruct,
  216. struct kobject *fskobj);
  217. void gfs2_unmount_lockproto(struct lm_lockstruct *lockstruct);
  218. void gfs2_withdraw_lockproto(struct lm_lockstruct *lockstruct);
  219. #endif /* __LM_INTERFACE_DOT_H__ */