fs/gfs2/glock.h

   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_NODE_SCOPE
  72  * This holder agrees to share the lock within this node. In other words,
  73  * the glock is held in EX mode according to DLM, but local holders on the
  74  * same node can share it.
  75  */
  76
  77 #define LM_FLAG_TRY             0x0001
  78 #define LM_FLAG_TRY_1CB         0x0002
  79 #define LM_FLAG_NOEXP           0x0004
  80 #define LM_FLAG_ANY             0x0008
  81 #define LM_FLAG_NODE_SCOPE      0x0020
  82 #define GL_ASYNC                0x0040
  83 #define GL_EXACT                0x0080
  84 #define GL_SKIP                 0x0100
  85 #define GL_NOPID                0x0200
  86 #define GL_NOCACHE              0x0400
  87 #define GL_NOBLOCK              0x0800
  88
  89 /*
  90  * lm_async_cb return flags
  91  *
  92  * LM_OUT_ST_MASK
  93  * Masks the lower two bits of lock state in the returned value.
  94  *
  95  * LM_OUT_CANCELED
  96  * The lock request was canceled.
  97  *
  98  */
  99
 100 #define LM_OUT_ST_MASK          0x00000003
 101 #define LM_OUT_CANCELED         0x00000008
 102 #define LM_OUT_ERROR            0x00000004
 103
 104 /*
 105  * lm_recovery_done() messages
 106  */
 107
 108 #define LM_RD_GAVEUP            308
 109 #define LM_RD_SUCCESS           309
 110
 111 #define GLR_TRYFAILED           13
 112
 113 #define GL_GLOCK_MAX_HOLD        (long)(HZ / 5)
 114 #define GL_GLOCK_DFT_HOLD        (long)(HZ / 5)
 115 #define GL_GLOCK_MIN_HOLD        (long)(10)
 116 #define GL_GLOCK_HOLD_INCR       (long)(HZ / 20)
 117 #define GL_GLOCK_HOLD_DECR       (long)(HZ / 40)
 118
 119 struct lm_lockops {
 120         const char *lm_proto_name;
 121         int (*lm_mount) (struct gfs2_sbd *sdp, const char *table);
 122         void (*lm_first_done) (struct gfs2_sbd *sdp);
 123         void (*lm_recovery_result) (struct gfs2_sbd *sdp, unsigned int jid,
 124                                     unsigned int result);
 125         void (*lm_unmount) (struct gfs2_sbd *sdp);
 126         void (*lm_withdraw) (struct gfs2_sbd *sdp);
 127         void (*lm_put_lock) (struct gfs2_glock *gl);
 128         int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state,
 129                         unsigned int flags);
 130         void (*lm_cancel) (struct gfs2_glock *gl);
 131         const match_table_t *lm_tokens;
 132 };
 133
 134 struct gfs2_glock_aspace {
 135         struct gfs2_glock glock;
 136         struct address_space mapping;
 137 };
 138
 139 static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
 140 {
 141         struct gfs2_holder *gh;
 142         struct pid *pid;
 143
 144         /* Look in glock's list of holders for one with current task as owner */
 145         spin_lock(&gl->gl_lockref.lock);
 146         pid = task_pid(current);
 147         list_for_each_entry(gh, &gl->gl_holders, gh_list) {
 148                 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
 149                         break;
 150                 if (gh->gh_owner_pid == pid)
 151                         goto out;
 152         }
 153         gh = NULL;
 154 out:
 155         spin_unlock(&gl->gl_lockref.lock);
 156
 157         return gh;
 158 }
 159
 160 static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
 161 {
 162         if (gl->gl_ops->go_flags & GLOF_ASPACE) {
 163                 struct gfs2_glock_aspace *gla =
 164                         container_of(gl, struct gfs2_glock_aspace, glock);
 165                 return &gla->mapping;
 166         }
 167         return NULL;
 168 }
 169
 170 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
 171                    const struct gfs2_glock_operations *glops,
 172                    int create, struct gfs2_glock **glp);
 173 struct gfs2_glock *gfs2_glock_hold(struct gfs2_glock *gl);
 174 void gfs2_glock_put(struct gfs2_glock *gl);
 175 void gfs2_glock_put_async(struct gfs2_glock *gl);
 176
 177 void __gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
 178                         u16 flags, struct gfs2_holder *gh,
 179                         unsigned long ip);
 180 static inline void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
 181                                     u16 flags, struct gfs2_holder *gh) {
 182         __gfs2_holder_init(gl, state, flags, gh, _RET_IP_);
 183 }
 184
 185 void gfs2_holder_reinit(unsigned int state, u16 flags,
 186                         struct gfs2_holder *gh);
 187 void gfs2_holder_uninit(struct gfs2_holder *gh);
 188 int gfs2_glock_nq(struct gfs2_holder *gh);
 189 int gfs2_glock_poll(struct gfs2_holder *gh);
 190 int gfs2_instantiate(struct gfs2_holder *gh);
 191 int gfs2_glock_holder_ready(struct gfs2_holder *gh);
 192 int gfs2_glock_wait(struct gfs2_holder *gh);
 193 int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs);
 194 void gfs2_glock_dq(struct gfs2_holder *gh);
 195 void gfs2_glock_dq_wait(struct gfs2_holder *gh);
 196 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
 197 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 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
 202 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
 203 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 #define gfs2_glock_assert_warn(gl, x) do { if (unlikely(!(x))) {        \
 209                         gfs2_dump_glock(NULL, gl, true);                \
 210                         gfs2_assert_warn((gl)->gl_name.ln_sbd, (x)); } } \
 211         while (0)
 212 #define gfs2_glock_assert_withdraw(gl, x) do { if (unlikely(!(x))) {    \
 213                         gfs2_dump_glock(NULL, gl, true);                \
 214                         gfs2_assert_withdraw((gl)->gl_name.ln_sbd, (x)); } } \
 215         while (0)
 216
 217 __printf(2, 3)
 218 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
 219
 220 /**
 221  * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
 222  * @gl: the glock
 223  * @state: the state we're requesting
 224  * @flags: the modifier flags
 225  * @gh: the holder structure
 226  *
 227  * Returns: 0, GLR_*, or errno
 228  */
 229
 230 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
 231                                      unsigned int state, u16 flags,
 232                                      struct gfs2_holder *gh)
 233 {
 234         int error;
 235
 236         __gfs2_holder_init(gl, state, flags, gh, _RET_IP_);
 237
 238         error = gfs2_glock_nq(gh);
 239         if (error)
 240                 gfs2_holder_uninit(gh);
 241
 242         return error;
 243 }
 244
 245 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
 246 void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
 247 bool gfs2_queue_try_to_evict(struct gfs2_glock *gl);
 248 bool gfs2_queue_verify_delete(struct gfs2_glock *gl, bool later);
 249 void gfs2_cancel_delete_work(struct gfs2_glock *gl);
 250 void gfs2_flush_delete_work(struct gfs2_sbd *sdp);
 251 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
 252 void gfs2_gl_dq_holders(struct gfs2_sbd *sdp);
 253 void gfs2_glock_thaw(struct gfs2_sbd *sdp);
 254 void gfs2_glock_free(struct gfs2_glock *gl);
 255 void gfs2_glock_free_later(struct gfs2_glock *gl);
 256
 257 int __init gfs2_glock_init(void);
 258 void gfs2_glock_exit(void);
 259
 260 void gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
 261 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
 262 void gfs2_register_debugfs(void);
 263 void gfs2_unregister_debugfs(void);
 264
 265 void glock_set_object(struct gfs2_glock *gl, void *object);
 266 void glock_clear_object(struct gfs2_glock *gl, void *object);
 267
 268 extern const struct lm_lockops gfs2_dlm_ops;
 269
 270 static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh)
 271 {
 272         gh->gh_gl = NULL;
 273 }
 274
 275 static inline bool gfs2_holder_initialized(struct gfs2_holder *gh)
 276 {
 277         return gh->gh_gl;
 278 }
 279
 280 static inline bool gfs2_holder_queued(struct gfs2_holder *gh)
 281 {
 282         return !list_empty(&gh->gh_list);
 283 }
 284
 285 void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation);
 286 bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation);
 287
 288 static inline bool glock_needs_demote(struct gfs2_glock *gl)
 289 {
 290         return (test_bit(GLF_DEMOTE, &gl->gl_flags) ||
 291                 test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags));
 292 }
 293
 294 #endif /* __GLOCK_DOT_H__ */