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 80 #define LM_FLAG_TRY 0x0001 81 #define LM_FLAG_TRY_1CB 0x0002 82 #define LM_FLAG_NOEXP 0x0004 83 #define LM_FLAG_ANY 0x0008 84 #define LM_FLAG_PRIORITY 0x0010 85 #define GL_ASYNC 0x0040 86 #define GL_EXACT 0x0080 87 #define GL_SKIP 0x0100 88 #define GL_NOCACHE 0x0400 89 90 /* 91 * lm_async_cb return flags 92 * 93 * LM_OUT_ST_MASK 94 * Masks the lower two bits of lock state in the returned value. 95 * 96 * LM_OUT_CANCELED 97 * The lock request was canceled. 98 * 99 */ 100 101 #define LM_OUT_ST_MASK 0x00000003 102 #define LM_OUT_CANCELED 0x00000008 103 #define LM_OUT_ERROR 0x00000004 104 105 /* 106 * lm_recovery_done() messages 107 */ 108 109 #define LM_RD_GAVEUP 308 110 #define LM_RD_SUCCESS 309 111 112 #define GLR_TRYFAILED 13 113 114 #define GL_GLOCK_MAX_HOLD (long)(HZ / 5) 115 #define GL_GLOCK_DFT_HOLD (long)(HZ / 5) 116 #define GL_GLOCK_MIN_HOLD (long)(10) 117 #define GL_GLOCK_HOLD_INCR (long)(HZ / 20) 118 #define GL_GLOCK_HOLD_DECR (long)(HZ / 40) 119 120 struct lm_lockops { 121 const char *lm_proto_name; 122 int (*lm_mount) (struct gfs2_sbd *sdp, const char *table); 123 void (*lm_first_done) (struct gfs2_sbd *sdp); 124 void (*lm_recovery_result) (struct gfs2_sbd *sdp, unsigned int jid, 125 unsigned int result); 126 void (*lm_unmount) (struct gfs2_sbd *sdp); 127 void (*lm_withdraw) (struct gfs2_sbd *sdp); 128 void (*lm_put_lock) (struct gfs2_glock *gl); 129 int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state, 130 unsigned int flags); 131 void (*lm_cancel) (struct gfs2_glock *gl); 132 const match_table_t *lm_tokens; 133 }; 134 135 extern struct workqueue_struct *gfs2_delete_workqueue; 136 static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl) 137 { 138 struct gfs2_holder *gh; 139 struct pid *pid; 140 141 /* Look in glock's list of holders for one with current task as owner */ 142 spin_lock(&gl->gl_lockref.lock); 143 pid = task_pid(current); 144 list_for_each_entry(gh, &gl->gl_holders, gh_list) { 145 if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) 146 break; 147 if (gh->gh_owner_pid == pid) 148 goto out; 149 } 150 gh = NULL; 151 out: 152 spin_unlock(&gl->gl_lockref.lock); 153 154 return gh; 155 } 156 157 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl) 158 { 159 return gl->gl_state == LM_ST_EXCLUSIVE; 160 } 161 162 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl) 163 { 164 return gl->gl_state == LM_ST_DEFERRED; 165 } 166 167 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl) 168 { 169 return gl->gl_state == LM_ST_SHARED; 170 } 171 172 static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl) 173 { 174 if (gl->gl_ops->go_flags & GLOF_ASPACE) 175 return (struct address_space *)(gl + 1); 176 return NULL; 177 } 178 179 extern int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, 180 const struct gfs2_glock_operations *glops, 181 int create, struct gfs2_glock **glp); 182 extern void gfs2_glock_hold(struct gfs2_glock *gl); 183 extern void gfs2_glock_put(struct gfs2_glock *gl); 184 extern void gfs2_glock_queue_put(struct gfs2_glock *gl); 185 extern void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, 186 u16 flags, struct gfs2_holder *gh); 187 extern void gfs2_holder_reinit(unsigned int state, u16 flags, 188 struct gfs2_holder *gh); 189 extern void gfs2_holder_uninit(struct gfs2_holder *gh); 190 extern int gfs2_glock_nq(struct gfs2_holder *gh); 191 extern int gfs2_glock_poll(struct gfs2_holder *gh); 192 extern int gfs2_glock_wait(struct gfs2_holder *gh); 193 extern int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs); 194 extern void gfs2_glock_dq(struct gfs2_holder *gh); 195 extern void gfs2_glock_dq_wait(struct gfs2_holder *gh); 196 extern void gfs2_glock_dq_uninit(struct gfs2_holder *gh); 197 extern int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, 198 const struct gfs2_glock_operations *glops, 199 unsigned int state, u16 flags, 200 struct gfs2_holder *gh); 201 extern int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs); 202 extern void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs); 203 extern void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl, 204 bool fsid); 205 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { \ 206 gfs2_dump_glock(NULL, gl, true); \ 207 BUG(); } } while(0) 208 extern __printf(2, 3) 209 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...); 210 211 /** 212 * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock 213 * @gl: the glock 214 * @state: the state we're requesting 215 * @flags: the modifier flags 216 * @gh: the holder structure 217 * 218 * Returns: 0, GLR_*, or errno 219 */ 220 221 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl, 222 unsigned int state, u16 flags, 223 struct gfs2_holder *gh) 224 { 225 int error; 226 227 gfs2_holder_init(gl, state, flags, gh); 228 229 error = gfs2_glock_nq(gh); 230 if (error) 231 gfs2_holder_uninit(gh); 232 233 return error; 234 } 235 236 extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state); 237 extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret); 238 extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp); 239 extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip); 240 extern void gfs2_glock_thaw(struct gfs2_sbd *sdp); 241 extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl); 242 extern void gfs2_glock_free(struct gfs2_glock *gl); 243 244 extern int __init gfs2_glock_init(void); 245 extern void gfs2_glock_exit(void); 246 247 extern void gfs2_create_debugfs_file(struct gfs2_sbd *sdp); 248 extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp); 249 extern void gfs2_register_debugfs(void); 250 extern void gfs2_unregister_debugfs(void); 251 252 extern const struct lm_lockops gfs2_dlm_ops; 253 254 static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh) 255 { 256 gh->gh_gl = NULL; 257 } 258 259 static inline bool gfs2_holder_initialized(struct gfs2_holder *gh) 260 { 261 return gh->gh_gl; 262 } 263 264 static inline bool gfs2_holder_queued(struct gfs2_holder *gh) 265 { 266 return !list_empty(&gh->gh_list); 267 } 268 269 /** 270 * glock_set_object - set the gl_object field of a glock 271 * @gl: the glock 272 * @object: the object 273 */ 274 static inline void glock_set_object(struct gfs2_glock *gl, void *object) 275 { 276 spin_lock(&gl->gl_lockref.lock); 277 if (gfs2_assert_warn(gl->gl_name.ln_sbd, gl->gl_object == NULL)) 278 gfs2_dump_glock(NULL, gl, true); 279 gl->gl_object = object; 280 spin_unlock(&gl->gl_lockref.lock); 281 } 282 283 /** 284 * glock_clear_object - clear the gl_object field of a glock 285 * @gl: the glock 286 * @object: the object 287 * 288 * I'd love to similarly add this: 289 * else if (gfs2_assert_warn(gl->gl_sbd, gl->gl_object == object)) 290 * gfs2_dump_glock(NULL, gl, true); 291 * Unfortunately, that's not possible because as soon as gfs2_delete_inode 292 * frees the block in the rgrp, another process can reassign it for an I_NEW 293 * inode in gfs2_create_inode because that calls new_inode, not gfs2_iget. 294 * That means gfs2_delete_inode may subsequently try to call this function 295 * for a glock that's already pointing to a brand new inode. If we clear the 296 * new inode's gl_object, we'll introduce metadata corruption. Function 297 * gfs2_delete_inode calls clear_inode which calls gfs2_clear_inode which also 298 * tries to clear gl_object, so it's more than just gfs2_delete_inode. 299 * 300 */ 301 static inline void glock_clear_object(struct gfs2_glock *gl, void *object) 302 { 303 spin_lock(&gl->gl_lockref.lock); 304 if (gl->gl_object == object) 305 gl->gl_object = NULL; 306 spin_unlock(&gl->gl_lockref.lock); 307 } 308 309 #endif /* __GLOCK_DOT_H__ */ 310