1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 4 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. 5 */ 6 7 #ifndef __GLOCK_DOT_H__ 8 #define __GLOCK_DOT_H__ 9 10 #include <linux/sched.h> 11 #include <linux/parser.h> 12 #include "incore.h" 13 #include "util.h" 14 15 /* Options for hostdata parser */ 16 17 enum { 18 Opt_jid, 19 Opt_id, 20 Opt_first, 21 Opt_nodir, 22 Opt_err, 23 }; 24 25 /* 26 * lm_lockname types 27 */ 28 29 #define LM_TYPE_RESERVED 0x00 30 #define LM_TYPE_NONDISK 0x01 31 #define LM_TYPE_INODE 0x02 32 #define LM_TYPE_RGRP 0x03 33 #define LM_TYPE_META 0x04 34 #define LM_TYPE_IOPEN 0x05 35 #define LM_TYPE_FLOCK 0x06 36 #define LM_TYPE_PLOCK 0x07 37 #define LM_TYPE_QUOTA 0x08 38 #define LM_TYPE_JOURNAL 0x09 39 40 /* 41 * lm_lock() states 42 * 43 * SHARED is compatible with SHARED, not with DEFERRED or EX. 44 * DEFERRED is compatible with DEFERRED, not with SHARED or EX. 45 */ 46 47 #define LM_ST_UNLOCKED 0 48 #define LM_ST_EXCLUSIVE 1 49 #define LM_ST_DEFERRED 2 50 #define LM_ST_SHARED 3 51 52 /* 53 * lm_lock() flags 54 * 55 * LM_FLAG_TRY 56 * Don't wait to acquire the lock if it can't be granted immediately. 57 * 58 * LM_FLAG_TRY_1CB 59 * Send one blocking callback if TRY is set and the lock is not granted. 60 * 61 * LM_FLAG_NOEXP 62 * GFS sets this flag on lock requests it makes while doing journal recovery. 63 * These special requests should not be blocked due to the recovery like 64 * ordinary locks would be. 65 * 66 * LM_FLAG_ANY 67 * A SHARED request may also be granted in DEFERRED, or a DEFERRED request may 68 * also be granted in SHARED. The preferred state is whichever is compatible 69 * with other granted locks, or the specified state if no other locks exist. 70 * 71 * LM_FLAG_PRIORITY 72 * Override fairness considerations. Suppose a lock is held in a shared state 73 * and there is a pending request for the deferred state. A shared lock 74 * request with the priority flag would be allowed to bypass the deferred 75 * request and directly join the other shared lock. A shared lock request 76 * without the priority flag might be forced to wait until the deferred 77 * requested had acquired and released the lock. 78 * 79 * LM_FLAG_NODE_SCOPE 80 * This holder agrees to share the lock within this node. In other words, 81 * the glock is held in EX mode according to DLM, but local holders on the 82 * same node can share it. 83 */ 84 85 #define LM_FLAG_TRY 0x0001 86 #define LM_FLAG_TRY_1CB 0x0002 87 #define LM_FLAG_NOEXP 0x0004 88 #define LM_FLAG_ANY 0x0008 89 #define LM_FLAG_PRIORITY 0x0010 90 #define LM_FLAG_NODE_SCOPE 0x0020 91 #define GL_ASYNC 0x0040 92 #define GL_EXACT 0x0080 93 #define GL_SKIP 0x0100 94 #define GL_NOCACHE 0x0400 95 96 /* 97 * lm_async_cb return flags 98 * 99 * LM_OUT_ST_MASK 100 * Masks the lower two bits of lock state in the returned value. 101 * 102 * LM_OUT_CANCELED 103 * The lock request was canceled. 104 * 105 */ 106 107 #define LM_OUT_ST_MASK 0x00000003 108 #define LM_OUT_CANCELED 0x00000008 109 #define LM_OUT_ERROR 0x00000004 110 111 /* 112 * lm_recovery_done() messages 113 */ 114 115 #define LM_RD_GAVEUP 308 116 #define LM_RD_SUCCESS 309 117 118 #define GLR_TRYFAILED 13 119 120 #define GL_GLOCK_MAX_HOLD (long)(HZ / 5) 121 #define GL_GLOCK_DFT_HOLD (long)(HZ / 5) 122 #define GL_GLOCK_MIN_HOLD (long)(10) 123 #define GL_GLOCK_HOLD_INCR (long)(HZ / 20) 124 #define GL_GLOCK_HOLD_DECR (long)(HZ / 40) 125 126 struct lm_lockops { 127 const char *lm_proto_name; 128 int (*lm_mount) (struct gfs2_sbd *sdp, const char *table); 129 void (*lm_first_done) (struct gfs2_sbd *sdp); 130 void (*lm_recovery_result) (struct gfs2_sbd *sdp, unsigned int jid, 131 unsigned int result); 132 void (*lm_unmount) (struct gfs2_sbd *sdp); 133 void (*lm_withdraw) (struct gfs2_sbd *sdp); 134 void (*lm_put_lock) (struct gfs2_glock *gl); 135 int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state, 136 unsigned int flags); 137 void (*lm_cancel) (struct gfs2_glock *gl); 138 const match_table_t *lm_tokens; 139 }; 140 141 extern struct workqueue_struct *gfs2_delete_workqueue; 142 static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl) 143 { 144 struct gfs2_holder *gh; 145 struct pid *pid; 146 147 /* Look in glock's list of holders for one with current task as owner */ 148 spin_lock(&gl->gl_lockref.lock); 149 pid = task_pid(current); 150 list_for_each_entry(gh, &gl->gl_holders, gh_list) { 151 if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) 152 break; 153 if (gh->gh_owner_pid == pid) 154 goto out; 155 } 156 gh = NULL; 157 out: 158 spin_unlock(&gl->gl_lockref.lock); 159 160 return gh; 161 } 162 163 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl) 164 { 165 return gl->gl_state == LM_ST_EXCLUSIVE; 166 } 167 168 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl) 169 { 170 return gl->gl_state == LM_ST_DEFERRED; 171 } 172 173 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl) 174 { 175 return gl->gl_state == LM_ST_SHARED; 176 } 177 178 static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl) 179 { 180 if (gl->gl_ops->go_flags & GLOF_ASPACE) 181 return (struct address_space *)(gl + 1); 182 return NULL; 183 } 184 185 extern int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, 186 const struct gfs2_glock_operations *glops, 187 int create, struct gfs2_glock **glp); 188 extern void gfs2_glock_hold(struct gfs2_glock *gl); 189 extern void gfs2_glock_put(struct gfs2_glock *gl); 190 extern void gfs2_glock_queue_put(struct gfs2_glock *gl); 191 extern void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, 192 u16 flags, struct gfs2_holder *gh); 193 extern void gfs2_holder_reinit(unsigned int state, u16 flags, 194 struct gfs2_holder *gh); 195 extern void gfs2_holder_uninit(struct gfs2_holder *gh); 196 extern int gfs2_glock_nq(struct gfs2_holder *gh); 197 extern int gfs2_glock_poll(struct gfs2_holder *gh); 198 extern int gfs2_glock_wait(struct gfs2_holder *gh); 199 extern int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs); 200 extern void gfs2_glock_dq(struct gfs2_holder *gh); 201 extern void gfs2_glock_dq_wait(struct gfs2_holder *gh); 202 extern void gfs2_glock_dq_uninit(struct gfs2_holder *gh); 203 extern int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, 204 const struct gfs2_glock_operations *glops, 205 unsigned int state, u16 flags, 206 struct gfs2_holder *gh); 207 extern int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs); 208 extern void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs); 209 extern void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl, 210 bool fsid); 211 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { \ 212 gfs2_dump_glock(NULL, gl, true); \ 213 BUG(); } } while(0) 214 #define gfs2_glock_assert_warn(gl, x) do { if (unlikely(!(x))) { \ 215 gfs2_dump_glock(NULL, gl, true); \ 216 gfs2_assert_warn((gl)->gl_name.ln_sbd, (x)); } } \ 217 while (0) 218 #define gfs2_glock_assert_withdraw(gl, x) do { if (unlikely(!(x))) { \ 219 gfs2_dump_glock(NULL, gl, true); \ 220 gfs2_assert_withdraw((gl)->gl_name.ln_sbd, (x)); } } \ 221 while (0) 222 223 extern __printf(2, 3) 224 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...); 225 226 /** 227 * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock 228 * @gl: the glock 229 * @state: the state we're requesting 230 * @flags: the modifier flags 231 * @gh: the holder structure 232 * 233 * Returns: 0, GLR_*, or errno 234 */ 235 236 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl, 237 unsigned int state, u16 flags, 238 struct gfs2_holder *gh) 239 { 240 int error; 241 242 gfs2_holder_init(gl, state, flags, gh); 243 244 error = gfs2_glock_nq(gh); 245 if (error) 246 gfs2_holder_uninit(gh); 247 248 return error; 249 } 250 251 extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state); 252 extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret); 253 extern bool gfs2_queue_delete_work(struct gfs2_glock *gl, unsigned long delay); 254 extern void gfs2_cancel_delete_work(struct gfs2_glock *gl); 255 extern bool gfs2_delete_work_queued(const struct gfs2_glock *gl); 256 extern void gfs2_flush_delete_work(struct gfs2_sbd *sdp); 257 extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp); 258 extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip); 259 extern void gfs2_glock_thaw(struct gfs2_sbd *sdp); 260 extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl); 261 extern void gfs2_glock_free(struct gfs2_glock *gl); 262 263 extern int __init gfs2_glock_init(void); 264 extern void gfs2_glock_exit(void); 265 266 extern void gfs2_create_debugfs_file(struct gfs2_sbd *sdp); 267 extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp); 268 extern void gfs2_register_debugfs(void); 269 extern void gfs2_unregister_debugfs(void); 270 271 extern const struct lm_lockops gfs2_dlm_ops; 272 273 static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh) 274 { 275 gh->gh_gl = NULL; 276 } 277 278 static inline bool gfs2_holder_initialized(struct gfs2_holder *gh) 279 { 280 return gh->gh_gl; 281 } 282 283 static inline bool gfs2_holder_queued(struct gfs2_holder *gh) 284 { 285 return !list_empty(&gh->gh_list); 286 } 287 288 /** 289 * glock_set_object - set the gl_object field of a glock 290 * @gl: the glock 291 * @object: the object 292 */ 293 static inline void glock_set_object(struct gfs2_glock *gl, void *object) 294 { 295 spin_lock(&gl->gl_lockref.lock); 296 if (gfs2_assert_warn(gl->gl_name.ln_sbd, gl->gl_object == NULL)) 297 gfs2_dump_glock(NULL, gl, true); 298 gl->gl_object = object; 299 spin_unlock(&gl->gl_lockref.lock); 300 } 301 302 /** 303 * glock_clear_object - clear the gl_object field of a glock 304 * @gl: the glock 305 * @object: the object 306 * 307 * I'd love to similarly add this: 308 * else if (gfs2_assert_warn(gl->gl_sbd, gl->gl_object == object)) 309 * gfs2_dump_glock(NULL, gl, true); 310 * Unfortunately, that's not possible because as soon as gfs2_delete_inode 311 * frees the block in the rgrp, another process can reassign it for an I_NEW 312 * inode in gfs2_create_inode because that calls new_inode, not gfs2_iget. 313 * That means gfs2_delete_inode may subsequently try to call this function 314 * for a glock that's already pointing to a brand new inode. If we clear the 315 * new inode's gl_object, we'll introduce metadata corruption. Function 316 * gfs2_delete_inode calls clear_inode which calls gfs2_clear_inode which also 317 * tries to clear gl_object, so it's more than just gfs2_delete_inode. 318 * 319 */ 320 static inline void glock_clear_object(struct gfs2_glock *gl, void *object) 321 { 322 spin_lock(&gl->gl_lockref.lock); 323 if (gl->gl_object == object) 324 gl->gl_object = NULL; 325 spin_unlock(&gl->gl_lockref.lock); 326 } 327 328 extern void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation); 329 extern bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation); 330 331 #endif /* __GLOCK_DOT_H__ */ 332