| 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /****************************************************************************** |
| 3 | ******************************************************************************* |
| 4 | ** |
| 5 | ** Copyright (C) 2005-2010 Red Hat, Inc. All rights reserved. |
| 6 | ** |
| 7 | ** |
| 8 | ******************************************************************************* |
| 9 | ******************************************************************************/ |
| 10 | |
| 11 | /* Central locking logic has four stages: |
| 12 | |
| 13 | dlm_lock() |
| 14 | dlm_unlock() |
| 15 | |
| 16 | request_lock(ls, lkb) |
| 17 | convert_lock(ls, lkb) |
| 18 | unlock_lock(ls, lkb) |
| 19 | cancel_lock(ls, lkb) |
| 20 | |
| 21 | _request_lock(r, lkb) |
| 22 | _convert_lock(r, lkb) |
| 23 | _unlock_lock(r, lkb) |
| 24 | _cancel_lock(r, lkb) |
| 25 | |
| 26 | do_request(r, lkb) |
| 27 | do_convert(r, lkb) |
| 28 | do_unlock(r, lkb) |
| 29 | do_cancel(r, lkb) |
| 30 | |
| 31 | Stage 1 (lock, unlock) is mainly about checking input args and |
| 32 | splitting into one of the four main operations: |
| 33 | |
| 34 | dlm_lock = request_lock |
| 35 | dlm_lock+CONVERT = convert_lock |
| 36 | dlm_unlock = unlock_lock |
| 37 | dlm_unlock+CANCEL = cancel_lock |
| 38 | |
| 39 | Stage 2, xxxx_lock(), just finds and locks the relevant rsb which is |
| 40 | provided to the next stage. |
| 41 | |
| 42 | Stage 3, _xxxx_lock(), determines if the operation is local or remote. |
| 43 | When remote, it calls send_xxxx(), when local it calls do_xxxx(). |
| 44 | |
| 45 | Stage 4, do_xxxx(), is the guts of the operation. It manipulates the |
| 46 | given rsb and lkb and queues callbacks. |
| 47 | |
| 48 | For remote operations, send_xxxx() results in the corresponding do_xxxx() |
| 49 | function being executed on the remote node. The connecting send/receive |
| 50 | calls on local (L) and remote (R) nodes: |
| 51 | |
| 52 | L: send_xxxx() -> R: receive_xxxx() |
| 53 | R: do_xxxx() |
| 54 | L: receive_xxxx_reply() <- R: send_xxxx_reply() |
| 55 | */ |
| 56 | #include <trace/events/dlm.h> |
| 57 | |
| 58 | #include <linux/types.h> |
| 59 | #include <linux/rbtree.h> |
| 60 | #include <linux/slab.h> |
| 61 | #include "dlm_internal.h" |
| 62 | #include <linux/dlm_device.h> |
| 63 | #include "memory.h" |
| 64 | #include "midcomms.h" |
| 65 | #include "requestqueue.h" |
| 66 | #include "util.h" |
| 67 | #include "dir.h" |
| 68 | #include "member.h" |
| 69 | #include "lockspace.h" |
| 70 | #include "ast.h" |
| 71 | #include "lock.h" |
| 72 | #include "rcom.h" |
| 73 | #include "recover.h" |
| 74 | #include "lvb_table.h" |
| 75 | #include "user.h" |
| 76 | #include "config.h" |
| 77 | |
| 78 | static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb); |
| 79 | static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb); |
| 80 | static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb); |
| 81 | static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb); |
| 82 | static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb); |
| 83 | static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode); |
| 84 | static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb); |
| 85 | static int send_remove(struct dlm_rsb *r); |
| 86 | static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb); |
| 87 | static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb); |
| 88 | static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, |
| 89 | const struct dlm_message *ms, bool local); |
| 90 | static int receive_extralen(const struct dlm_message *ms); |
| 91 | static void do_purge(struct dlm_ls *ls, int nodeid, int pid); |
| 92 | static void deactivate_rsb(struct kref *kref); |
| 93 | |
| 94 | /* |
| 95 | * Lock compatibilty matrix - thanks Steve |
| 96 | * UN = Unlocked state. Not really a state, used as a flag |
| 97 | * PD = Padding. Used to make the matrix a nice power of two in size |
| 98 | * Other states are the same as the VMS DLM. |
| 99 | * Usage: matrix[grmode+1][rqmode+1] (although m[rq+1][gr+1] is the same) |
| 100 | */ |
| 101 | |
| 102 | static const int __dlm_compat_matrix[8][8] = { |
| 103 | /* UN NL CR CW PR PW EX PD */ |
| 104 | {1, 1, 1, 1, 1, 1, 1, 0}, /* UN */ |
| 105 | {1, 1, 1, 1, 1, 1, 1, 0}, /* NL */ |
| 106 | {1, 1, 1, 1, 1, 1, 0, 0}, /* CR */ |
| 107 | {1, 1, 1, 1, 0, 0, 0, 0}, /* CW */ |
| 108 | {1, 1, 1, 0, 1, 0, 0, 0}, /* PR */ |
| 109 | {1, 1, 1, 0, 0, 0, 0, 0}, /* PW */ |
| 110 | {1, 1, 0, 0, 0, 0, 0, 0}, /* EX */ |
| 111 | {0, 0, 0, 0, 0, 0, 0, 0} /* PD */ |
| 112 | }; |
| 113 | |
| 114 | /* |
| 115 | * This defines the direction of transfer of LVB data. |
| 116 | * Granted mode is the row; requested mode is the column. |
| 117 | * Usage: matrix[grmode+1][rqmode+1] |
| 118 | * 1 = LVB is returned to the caller |
| 119 | * 0 = LVB is written to the resource |
| 120 | * -1 = nothing happens to the LVB |
| 121 | */ |
| 122 | |
| 123 | const int dlm_lvb_operations[8][8] = { |
| 124 | /* UN NL CR CW PR PW EX PD*/ |
| 125 | { -1, 1, 1, 1, 1, 1, 1, -1 }, /* UN */ |
| 126 | { -1, 1, 1, 1, 1, 1, 1, 0 }, /* NL */ |
| 127 | { -1, -1, 1, 1, 1, 1, 1, 0 }, /* CR */ |
| 128 | { -1, -1, -1, 1, 1, 1, 1, 0 }, /* CW */ |
| 129 | { -1, -1, -1, -1, 1, 1, 1, 0 }, /* PR */ |
| 130 | { -1, 0, 0, 0, 0, 0, 1, 0 }, /* PW */ |
| 131 | { -1, 0, 0, 0, 0, 0, 0, 0 }, /* EX */ |
| 132 | { -1, 0, 0, 0, 0, 0, 0, 0 } /* PD */ |
| 133 | }; |
| 134 | |
| 135 | #define modes_compat(gr, rq) \ |
| 136 | __dlm_compat_matrix[(gr)->lkb_grmode + 1][(rq)->lkb_rqmode + 1] |
| 137 | |
| 138 | int dlm_modes_compat(int mode1, int mode2) |
| 139 | { |
| 140 | return __dlm_compat_matrix[mode1 + 1][mode2 + 1]; |
| 141 | } |
| 142 | |
| 143 | /* |
| 144 | * Compatibility matrix for conversions with QUECVT set. |
| 145 | * Granted mode is the row; requested mode is the column. |
| 146 | * Usage: matrix[grmode+1][rqmode+1] |
| 147 | */ |
| 148 | |
| 149 | static const int __quecvt_compat_matrix[8][8] = { |
| 150 | /* UN NL CR CW PR PW EX PD */ |
| 151 | {0, 0, 0, 0, 0, 0, 0, 0}, /* UN */ |
| 152 | {0, 0, 1, 1, 1, 1, 1, 0}, /* NL */ |
| 153 | {0, 0, 0, 1, 1, 1, 1, 0}, /* CR */ |
| 154 | {0, 0, 0, 0, 1, 1, 1, 0}, /* CW */ |
| 155 | {0, 0, 0, 1, 0, 1, 1, 0}, /* PR */ |
| 156 | {0, 0, 0, 0, 0, 0, 1, 0}, /* PW */ |
| 157 | {0, 0, 0, 0, 0, 0, 0, 0}, /* EX */ |
| 158 | {0, 0, 0, 0, 0, 0, 0, 0} /* PD */ |
| 159 | }; |
| 160 | |
| 161 | void dlm_print_lkb(struct dlm_lkb *lkb) |
| 162 | { |
| 163 | printk(KERN_ERR "lkb: nodeid %d id %x remid %x exflags %x flags %x " |
| 164 | "sts %d rq %d gr %d wait_type %d wait_nodeid %d seq %llu\n", |
| 165 | lkb->lkb_nodeid, lkb->lkb_id, lkb->lkb_remid, lkb->lkb_exflags, |
| 166 | dlm_iflags_val(lkb), lkb->lkb_status, lkb->lkb_rqmode, |
| 167 | lkb->lkb_grmode, lkb->lkb_wait_type, lkb->lkb_wait_nodeid, |
| 168 | (unsigned long long)lkb->lkb_recover_seq); |
| 169 | } |
| 170 | |
| 171 | static void dlm_print_rsb(struct dlm_rsb *r) |
| 172 | { |
| 173 | printk(KERN_ERR "rsb: nodeid %d master %d dir %d flags %lx first %x " |
| 174 | "rlc %d name %s\n", |
| 175 | r->res_nodeid, r->res_master_nodeid, r->res_dir_nodeid, |
| 176 | r->res_flags, r->res_first_lkid, r->res_recover_locks_count, |
| 177 | r->res_name); |
| 178 | } |
| 179 | |
| 180 | void dlm_dump_rsb(struct dlm_rsb *r) |
| 181 | { |
| 182 | struct dlm_lkb *lkb; |
| 183 | |
| 184 | dlm_print_rsb(r); |
| 185 | |
| 186 | printk(KERN_ERR "rsb: root_list empty %d recover_list empty %d\n", |
| 187 | list_empty(&r->res_root_list), list_empty(&r->res_recover_list)); |
| 188 | printk(KERN_ERR "rsb lookup list\n"); |
| 189 | list_for_each_entry(lkb, &r->res_lookup, lkb_rsb_lookup) |
| 190 | dlm_print_lkb(lkb); |
| 191 | printk(KERN_ERR "rsb grant queue:\n"); |
| 192 | list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) |
| 193 | dlm_print_lkb(lkb); |
| 194 | printk(KERN_ERR "rsb convert queue:\n"); |
| 195 | list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) |
| 196 | dlm_print_lkb(lkb); |
| 197 | printk(KERN_ERR "rsb wait queue:\n"); |
| 198 | list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue) |
| 199 | dlm_print_lkb(lkb); |
| 200 | } |
| 201 | |
| 202 | /* Threads cannot use the lockspace while it's being recovered */ |
| 203 | |
| 204 | void dlm_lock_recovery(struct dlm_ls *ls) |
| 205 | { |
| 206 | down_read(&ls->ls_in_recovery); |
| 207 | } |
| 208 | |
| 209 | void dlm_unlock_recovery(struct dlm_ls *ls) |
| 210 | { |
| 211 | up_read(&ls->ls_in_recovery); |
| 212 | } |
| 213 | |
| 214 | int dlm_lock_recovery_try(struct dlm_ls *ls) |
| 215 | { |
| 216 | return down_read_trylock(&ls->ls_in_recovery); |
| 217 | } |
| 218 | |
| 219 | static inline int can_be_queued(struct dlm_lkb *lkb) |
| 220 | { |
| 221 | return !(lkb->lkb_exflags & DLM_LKF_NOQUEUE); |
| 222 | } |
| 223 | |
| 224 | static inline int force_blocking_asts(struct dlm_lkb *lkb) |
| 225 | { |
| 226 | return (lkb->lkb_exflags & DLM_LKF_NOQUEUEBAST); |
| 227 | } |
| 228 | |
| 229 | static inline int is_demoted(struct dlm_lkb *lkb) |
| 230 | { |
| 231 | return test_bit(DLM_SBF_DEMOTED_BIT, &lkb->lkb_sbflags); |
| 232 | } |
| 233 | |
| 234 | static inline int is_altmode(struct dlm_lkb *lkb) |
| 235 | { |
| 236 | return test_bit(DLM_SBF_ALTMODE_BIT, &lkb->lkb_sbflags); |
| 237 | } |
| 238 | |
| 239 | static inline int is_granted(struct dlm_lkb *lkb) |
| 240 | { |
| 241 | return (lkb->lkb_status == DLM_LKSTS_GRANTED); |
| 242 | } |
| 243 | |
| 244 | static inline int is_remote(struct dlm_rsb *r) |
| 245 | { |
| 246 | DLM_ASSERT(r->res_nodeid >= 0, dlm_print_rsb(r);); |
| 247 | return !!r->res_nodeid; |
| 248 | } |
| 249 | |
| 250 | static inline int is_process_copy(struct dlm_lkb *lkb) |
| 251 | { |
| 252 | return lkb->lkb_nodeid && |
| 253 | !test_bit(DLM_IFL_MSTCPY_BIT, &lkb->lkb_iflags); |
| 254 | } |
| 255 | |
| 256 | static inline int is_master_copy(struct dlm_lkb *lkb) |
| 257 | { |
| 258 | return test_bit(DLM_IFL_MSTCPY_BIT, &lkb->lkb_iflags); |
| 259 | } |
| 260 | |
| 261 | static inline int middle_conversion(struct dlm_lkb *lkb) |
| 262 | { |
| 263 | if ((lkb->lkb_grmode==DLM_LOCK_PR && lkb->lkb_rqmode==DLM_LOCK_CW) || |
| 264 | (lkb->lkb_rqmode==DLM_LOCK_PR && lkb->lkb_grmode==DLM_LOCK_CW)) |
| 265 | return 1; |
| 266 | return 0; |
| 267 | } |
| 268 | |
| 269 | static inline int down_conversion(struct dlm_lkb *lkb) |
| 270 | { |
| 271 | return (!middle_conversion(lkb) && lkb->lkb_rqmode < lkb->lkb_grmode); |
| 272 | } |
| 273 | |
| 274 | static inline int is_overlap_unlock(struct dlm_lkb *lkb) |
| 275 | { |
| 276 | return test_bit(DLM_IFL_OVERLAP_UNLOCK_BIT, &lkb->lkb_iflags); |
| 277 | } |
| 278 | |
| 279 | static inline int is_overlap_cancel(struct dlm_lkb *lkb) |
| 280 | { |
| 281 | return test_bit(DLM_IFL_OVERLAP_CANCEL_BIT, &lkb->lkb_iflags); |
| 282 | } |
| 283 | |
| 284 | static inline int is_overlap(struct dlm_lkb *lkb) |
| 285 | { |
| 286 | return test_bit(DLM_IFL_OVERLAP_UNLOCK_BIT, &lkb->lkb_iflags) || |
| 287 | test_bit(DLM_IFL_OVERLAP_CANCEL_BIT, &lkb->lkb_iflags); |
| 288 | } |
| 289 | |
| 290 | static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) |
| 291 | { |
| 292 | if (is_master_copy(lkb)) |
| 293 | return; |
| 294 | |
| 295 | DLM_ASSERT(lkb->lkb_lksb, dlm_print_lkb(lkb);); |
| 296 | |
| 297 | if (rv == -DLM_ECANCEL && |
| 298 | test_and_clear_bit(DLM_IFL_DEADLOCK_CANCEL_BIT, &lkb->lkb_iflags)) |
| 299 | rv = -EDEADLK; |
| 300 | |
| 301 | dlm_add_cb(lkb, DLM_CB_CAST, lkb->lkb_grmode, rv, dlm_sbflags_val(lkb)); |
| 302 | } |
| 303 | |
| 304 | static inline void queue_cast_overlap(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 305 | { |
| 306 | queue_cast(r, lkb, |
| 307 | is_overlap_unlock(lkb) ? -DLM_EUNLOCK : -DLM_ECANCEL); |
| 308 | } |
| 309 | |
| 310 | static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode) |
| 311 | { |
| 312 | if (is_master_copy(lkb)) { |
| 313 | send_bast(r, lkb, rqmode); |
| 314 | } else { |
| 315 | dlm_add_cb(lkb, DLM_CB_BAST, rqmode, 0, 0); |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | /* |
| 320 | * Basic operations on rsb's and lkb's |
| 321 | */ |
| 322 | |
| 323 | static inline unsigned long rsb_toss_jiffies(void) |
| 324 | { |
| 325 | return jiffies + (READ_ONCE(dlm_config.ci_toss_secs) * HZ); |
| 326 | } |
| 327 | |
| 328 | /* This is only called to add a reference when the code already holds |
| 329 | a valid reference to the rsb, so there's no need for locking. */ |
| 330 | |
| 331 | static inline void hold_rsb(struct dlm_rsb *r) |
| 332 | { |
| 333 | /* inactive rsbs are not ref counted */ |
| 334 | WARN_ON(rsb_flag(r, RSB_INACTIVE)); |
| 335 | kref_get(&r->res_ref); |
| 336 | } |
| 337 | |
| 338 | void dlm_hold_rsb(struct dlm_rsb *r) |
| 339 | { |
| 340 | hold_rsb(r); |
| 341 | } |
| 342 | |
| 343 | /* TODO move this to lib/refcount.c */ |
| 344 | static __must_check bool |
| 345 | dlm_refcount_dec_and_write_lock_bh(refcount_t *r, rwlock_t *lock) |
| 346 | __cond_acquires(lock) |
| 347 | { |
| 348 | if (refcount_dec_not_one(r)) |
| 349 | return false; |
| 350 | |
| 351 | write_lock_bh(lock); |
| 352 | if (!refcount_dec_and_test(r)) { |
| 353 | write_unlock_bh(lock); |
| 354 | return false; |
| 355 | } |
| 356 | |
| 357 | return true; |
| 358 | } |
| 359 | |
| 360 | /* TODO move this to include/linux/kref.h */ |
| 361 | static inline int dlm_kref_put_write_lock_bh(struct kref *kref, |
| 362 | void (*release)(struct kref *kref), |
| 363 | rwlock_t *lock) |
| 364 | { |
| 365 | if (dlm_refcount_dec_and_write_lock_bh(&kref->refcount, lock)) { |
| 366 | release(kref); |
| 367 | return 1; |
| 368 | } |
| 369 | |
| 370 | return 0; |
| 371 | } |
| 372 | |
| 373 | static void put_rsb(struct dlm_rsb *r) |
| 374 | { |
| 375 | struct dlm_ls *ls = r->res_ls; |
| 376 | int rv; |
| 377 | |
| 378 | rv = dlm_kref_put_write_lock_bh(&r->res_ref, deactivate_rsb, |
| 379 | &ls->ls_rsbtbl_lock); |
| 380 | if (rv) |
| 381 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 382 | } |
| 383 | |
| 384 | void dlm_put_rsb(struct dlm_rsb *r) |
| 385 | { |
| 386 | put_rsb(r); |
| 387 | } |
| 388 | |
| 389 | /* connected with timer_delete_sync() in dlm_ls_stop() to stop |
| 390 | * new timers when recovery is triggered and don't run them |
| 391 | * again until a resume_scan_timer() tries it again. |
| 392 | */ |
| 393 | static void enable_scan_timer(struct dlm_ls *ls, unsigned long jiffies) |
| 394 | { |
| 395 | if (!dlm_locking_stopped(ls)) |
| 396 | mod_timer(&ls->ls_scan_timer, jiffies); |
| 397 | } |
| 398 | |
| 399 | /* This function tries to resume the timer callback if a rsb |
| 400 | * is on the scan list and no timer is pending. It might that |
| 401 | * the first entry is on currently executed as timer callback |
| 402 | * but we don't care if a timer queued up again and does |
| 403 | * nothing. Should be a rare case. |
| 404 | */ |
| 405 | void resume_scan_timer(struct dlm_ls *ls) |
| 406 | { |
| 407 | struct dlm_rsb *r; |
| 408 | |
| 409 | spin_lock_bh(&ls->ls_scan_lock); |
| 410 | r = list_first_entry_or_null(&ls->ls_scan_list, struct dlm_rsb, |
| 411 | res_scan_list); |
| 412 | if (r && !timer_pending(&ls->ls_scan_timer)) |
| 413 | enable_scan_timer(ls, r->res_toss_time); |
| 414 | spin_unlock_bh(&ls->ls_scan_lock); |
| 415 | } |
| 416 | |
| 417 | /* ls_rsbtbl_lock must be held */ |
| 418 | |
| 419 | static void del_scan(struct dlm_ls *ls, struct dlm_rsb *r) |
| 420 | { |
| 421 | struct dlm_rsb *first; |
| 422 | |
| 423 | /* active rsbs should never be on the scan list */ |
| 424 | WARN_ON(!rsb_flag(r, RSB_INACTIVE)); |
| 425 | |
| 426 | spin_lock_bh(&ls->ls_scan_lock); |
| 427 | r->res_toss_time = 0; |
| 428 | |
| 429 | /* if the rsb is not queued do nothing */ |
| 430 | if (list_empty(&r->res_scan_list)) |
| 431 | goto out; |
| 432 | |
| 433 | /* get the first element before delete */ |
| 434 | first = list_first_entry(&ls->ls_scan_list, struct dlm_rsb, |
| 435 | res_scan_list); |
| 436 | list_del_init(&r->res_scan_list); |
| 437 | /* check if the first element was the rsb we deleted */ |
| 438 | if (first == r) { |
| 439 | /* try to get the new first element, if the list |
| 440 | * is empty now try to delete the timer, if we are |
| 441 | * too late we don't care. |
| 442 | * |
| 443 | * if the list isn't empty and a new first element got |
| 444 | * in place, set the new timer expire time. |
| 445 | */ |
| 446 | first = list_first_entry_or_null(&ls->ls_scan_list, struct dlm_rsb, |
| 447 | res_scan_list); |
| 448 | if (!first) |
| 449 | timer_delete(&ls->ls_scan_timer); |
| 450 | else |
| 451 | enable_scan_timer(ls, first->res_toss_time); |
| 452 | } |
| 453 | |
| 454 | out: |
| 455 | spin_unlock_bh(&ls->ls_scan_lock); |
| 456 | } |
| 457 | |
| 458 | static void add_scan(struct dlm_ls *ls, struct dlm_rsb *r) |
| 459 | { |
| 460 | int our_nodeid = dlm_our_nodeid(); |
| 461 | struct dlm_rsb *first; |
| 462 | |
| 463 | /* A dir record for a remote master rsb should never be on the scan list. */ |
| 464 | WARN_ON(!dlm_no_directory(ls) && |
| 465 | (r->res_master_nodeid != our_nodeid) && |
| 466 | (dlm_dir_nodeid(r) == our_nodeid)); |
| 467 | |
| 468 | /* An active rsb should never be on the scan list. */ |
| 469 | WARN_ON(!rsb_flag(r, RSB_INACTIVE)); |
| 470 | |
| 471 | /* An rsb should not already be on the scan list. */ |
| 472 | WARN_ON(!list_empty(&r->res_scan_list)); |
| 473 | |
| 474 | spin_lock_bh(&ls->ls_scan_lock); |
| 475 | /* set the new rsb absolute expire time in the rsb */ |
| 476 | r->res_toss_time = rsb_toss_jiffies(); |
| 477 | if (list_empty(&ls->ls_scan_list)) { |
| 478 | /* if the queue is empty add the element and it's |
| 479 | * our new expire time |
| 480 | */ |
| 481 | list_add_tail(&r->res_scan_list, &ls->ls_scan_list); |
| 482 | enable_scan_timer(ls, r->res_toss_time); |
| 483 | } else { |
| 484 | /* try to get the maybe new first element and then add |
| 485 | * to this rsb with the oldest expire time to the end |
| 486 | * of the queue. If the list was empty before this |
| 487 | * rsb expire time is our next expiration if it wasn't |
| 488 | * the now new first elemet is our new expiration time |
| 489 | */ |
| 490 | first = list_first_entry_or_null(&ls->ls_scan_list, struct dlm_rsb, |
| 491 | res_scan_list); |
| 492 | list_add_tail(&r->res_scan_list, &ls->ls_scan_list); |
| 493 | if (!first) |
| 494 | enable_scan_timer(ls, r->res_toss_time); |
| 495 | else |
| 496 | enable_scan_timer(ls, first->res_toss_time); |
| 497 | } |
| 498 | spin_unlock_bh(&ls->ls_scan_lock); |
| 499 | } |
| 500 | |
| 501 | /* if we hit contention we do in 250 ms a retry to trylock. |
| 502 | * if there is any other mod_timer in between we don't care |
| 503 | * about that it expires earlier again this is only for the |
| 504 | * unlikely case nothing happened in this time. |
| 505 | */ |
| 506 | #define DLM_TOSS_TIMER_RETRY (jiffies + msecs_to_jiffies(250)) |
| 507 | |
| 508 | /* Called by lockspace scan_timer to free unused rsb's. */ |
| 509 | |
| 510 | void dlm_rsb_scan(struct timer_list *timer) |
| 511 | { |
| 512 | struct dlm_ls *ls = from_timer(ls, timer, ls_scan_timer); |
| 513 | int our_nodeid = dlm_our_nodeid(); |
| 514 | struct dlm_rsb *r; |
| 515 | int rv; |
| 516 | |
| 517 | while (1) { |
| 518 | /* interrupting point to leave iteration when |
| 519 | * recovery waits for timer_delete_sync(), recovery |
| 520 | * will take care to delete everything in scan list. |
| 521 | */ |
| 522 | if (dlm_locking_stopped(ls)) |
| 523 | break; |
| 524 | |
| 525 | rv = spin_trylock(&ls->ls_scan_lock); |
| 526 | if (!rv) { |
| 527 | /* rearm again try timer */ |
| 528 | enable_scan_timer(ls, DLM_TOSS_TIMER_RETRY); |
| 529 | break; |
| 530 | } |
| 531 | |
| 532 | r = list_first_entry_or_null(&ls->ls_scan_list, struct dlm_rsb, |
| 533 | res_scan_list); |
| 534 | if (!r) { |
| 535 | /* the next add_scan will enable the timer again */ |
| 536 | spin_unlock(&ls->ls_scan_lock); |
| 537 | break; |
| 538 | } |
| 539 | |
| 540 | /* |
| 541 | * If the first rsb is not yet expired, then stop because the |
| 542 | * list is sorted with nearest expiration first. |
| 543 | */ |
| 544 | if (time_before(jiffies, r->res_toss_time)) { |
| 545 | /* rearm with the next rsb to expire in the future */ |
| 546 | enable_scan_timer(ls, r->res_toss_time); |
| 547 | spin_unlock(&ls->ls_scan_lock); |
| 548 | break; |
| 549 | } |
| 550 | |
| 551 | /* in find_rsb_dir/nodir there is a reverse order of this |
| 552 | * lock, however this is only a trylock if we hit some |
| 553 | * possible contention we try it again. |
| 554 | */ |
| 555 | rv = write_trylock(&ls->ls_rsbtbl_lock); |
| 556 | if (!rv) { |
| 557 | spin_unlock(&ls->ls_scan_lock); |
| 558 | /* rearm again try timer */ |
| 559 | enable_scan_timer(ls, DLM_TOSS_TIMER_RETRY); |
| 560 | break; |
| 561 | } |
| 562 | |
| 563 | list_del(&r->res_slow_list); |
| 564 | rhashtable_remove_fast(&ls->ls_rsbtbl, &r->res_node, |
| 565 | dlm_rhash_rsb_params); |
| 566 | rsb_clear_flag(r, RSB_HASHED); |
| 567 | |
| 568 | /* ls_rsbtbl_lock is not needed when calling send_remove() */ |
| 569 | write_unlock(&ls->ls_rsbtbl_lock); |
| 570 | |
| 571 | list_del_init(&r->res_scan_list); |
| 572 | spin_unlock(&ls->ls_scan_lock); |
| 573 | |
| 574 | /* An rsb that is a dir record for a remote master rsb |
| 575 | * cannot be removed, and should not have a timer enabled. |
| 576 | */ |
| 577 | WARN_ON(!dlm_no_directory(ls) && |
| 578 | (r->res_master_nodeid != our_nodeid) && |
| 579 | (dlm_dir_nodeid(r) == our_nodeid)); |
| 580 | |
| 581 | /* We're the master of this rsb but we're not |
| 582 | * the directory record, so we need to tell the |
| 583 | * dir node to remove the dir record |
| 584 | */ |
| 585 | if (!dlm_no_directory(ls) && |
| 586 | (r->res_master_nodeid == our_nodeid) && |
| 587 | (dlm_dir_nodeid(r) != our_nodeid)) |
| 588 | send_remove(r); |
| 589 | |
| 590 | free_inactive_rsb(r); |
| 591 | } |
| 592 | } |
| 593 | |
| 594 | /* If ls->ls_new_rsb is empty, return -EAGAIN, so the caller can |
| 595 | unlock any spinlocks, go back and call pre_rsb_struct again. |
| 596 | Otherwise, take an rsb off the list and return it. */ |
| 597 | |
| 598 | static int get_rsb_struct(struct dlm_ls *ls, const void *name, int len, |
| 599 | struct dlm_rsb **r_ret) |
| 600 | { |
| 601 | struct dlm_rsb *r; |
| 602 | |
| 603 | r = dlm_allocate_rsb(); |
| 604 | if (!r) |
| 605 | return -ENOMEM; |
| 606 | |
| 607 | r->res_ls = ls; |
| 608 | r->res_length = len; |
| 609 | memcpy(r->res_name, name, len); |
| 610 | spin_lock_init(&r->res_lock); |
| 611 | |
| 612 | INIT_LIST_HEAD(&r->res_lookup); |
| 613 | INIT_LIST_HEAD(&r->res_grantqueue); |
| 614 | INIT_LIST_HEAD(&r->res_convertqueue); |
| 615 | INIT_LIST_HEAD(&r->res_waitqueue); |
| 616 | INIT_LIST_HEAD(&r->res_root_list); |
| 617 | INIT_LIST_HEAD(&r->res_scan_list); |
| 618 | INIT_LIST_HEAD(&r->res_recover_list); |
| 619 | INIT_LIST_HEAD(&r->res_masters_list); |
| 620 | |
| 621 | *r_ret = r; |
| 622 | return 0; |
| 623 | } |
| 624 | |
| 625 | int dlm_search_rsb_tree(struct rhashtable *rhash, const void *name, int len, |
| 626 | struct dlm_rsb **r_ret) |
| 627 | { |
| 628 | char key[DLM_RESNAME_MAXLEN] = {}; |
| 629 | |
| 630 | memcpy(key, name, len); |
| 631 | *r_ret = rhashtable_lookup_fast(rhash, &key, dlm_rhash_rsb_params); |
| 632 | if (*r_ret) |
| 633 | return 0; |
| 634 | |
| 635 | return -EBADR; |
| 636 | } |
| 637 | |
| 638 | static int rsb_insert(struct dlm_rsb *rsb, struct rhashtable *rhash) |
| 639 | { |
| 640 | int rv; |
| 641 | |
| 642 | rv = rhashtable_insert_fast(rhash, &rsb->res_node, |
| 643 | dlm_rhash_rsb_params); |
| 644 | if (!rv) |
| 645 | rsb_set_flag(rsb, RSB_HASHED); |
| 646 | |
| 647 | return rv; |
| 648 | } |
| 649 | |
| 650 | /* |
| 651 | * Find rsb in rsbtbl and potentially create/add one |
| 652 | * |
| 653 | * Delaying the release of rsb's has a similar benefit to applications keeping |
| 654 | * NL locks on an rsb, but without the guarantee that the cached master value |
| 655 | * will still be valid when the rsb is reused. Apps aren't always smart enough |
| 656 | * to keep NL locks on an rsb that they may lock again shortly; this can lead |
| 657 | * to excessive master lookups and removals if we don't delay the release. |
| 658 | * |
| 659 | * Searching for an rsb means looking through both the normal list and toss |
| 660 | * list. When found on the toss list the rsb is moved to the normal list with |
| 661 | * ref count of 1; when found on normal list the ref count is incremented. |
| 662 | * |
| 663 | * rsb's on the keep list are being used locally and refcounted. |
| 664 | * rsb's on the toss list are not being used locally, and are not refcounted. |
| 665 | * |
| 666 | * The toss list rsb's were either |
| 667 | * - previously used locally but not any more (were on keep list, then |
| 668 | * moved to toss list when last refcount dropped) |
| 669 | * - created and put on toss list as a directory record for a lookup |
| 670 | * (we are the dir node for the res, but are not using the res right now, |
| 671 | * but some other node is) |
| 672 | * |
| 673 | * The purpose of find_rsb() is to return a refcounted rsb for local use. |
| 674 | * So, if the given rsb is on the toss list, it is moved to the keep list |
| 675 | * before being returned. |
| 676 | * |
| 677 | * deactivate_rsb() happens when all local usage of the rsb is done, i.e. no |
| 678 | * more refcounts exist, so the rsb is moved from the keep list to the |
| 679 | * toss list. |
| 680 | * |
| 681 | * rsb's on both keep and toss lists are used for doing a name to master |
| 682 | * lookups. rsb's that are in use locally (and being refcounted) are on |
| 683 | * the keep list, rsb's that are not in use locally (not refcounted) and |
| 684 | * only exist for name/master lookups are on the toss list. |
| 685 | * |
| 686 | * rsb's on the toss list who's dir_nodeid is not local can have stale |
| 687 | * name/master mappings. So, remote requests on such rsb's can potentially |
| 688 | * return with an error, which means the mapping is stale and needs to |
| 689 | * be updated with a new lookup. (The idea behind MASTER UNCERTAIN and |
| 690 | * first_lkid is to keep only a single outstanding request on an rsb |
| 691 | * while that rsb has a potentially stale master.) |
| 692 | */ |
| 693 | |
| 694 | static int find_rsb_dir(struct dlm_ls *ls, const void *name, int len, |
| 695 | uint32_t hash, int dir_nodeid, int from_nodeid, |
| 696 | unsigned int flags, struct dlm_rsb **r_ret) |
| 697 | { |
| 698 | struct dlm_rsb *r = NULL; |
| 699 | int our_nodeid = dlm_our_nodeid(); |
| 700 | int from_local = 0; |
| 701 | int from_other = 0; |
| 702 | int from_dir = 0; |
| 703 | int create = 0; |
| 704 | int error; |
| 705 | |
| 706 | if (flags & R_RECEIVE_REQUEST) { |
| 707 | if (from_nodeid == dir_nodeid) |
| 708 | from_dir = 1; |
| 709 | else |
| 710 | from_other = 1; |
| 711 | } else if (flags & R_REQUEST) { |
| 712 | from_local = 1; |
| 713 | } |
| 714 | |
| 715 | /* |
| 716 | * flags & R_RECEIVE_RECOVER is from dlm_recover_master_copy, so |
| 717 | * from_nodeid has sent us a lock in dlm_recover_locks, believing |
| 718 | * we're the new master. Our local recovery may not have set |
| 719 | * res_master_nodeid to our_nodeid yet, so allow either. Don't |
| 720 | * create the rsb; dlm_recover_process_copy() will handle EBADR |
| 721 | * by resending. |
| 722 | * |
| 723 | * If someone sends us a request, we are the dir node, and we do |
| 724 | * not find the rsb anywhere, then recreate it. This happens if |
| 725 | * someone sends us a request after we have removed/freed an rsb. |
| 726 | * (They sent a request instead of lookup because they are using |
| 727 | * an rsb taken from their scan list.) |
| 728 | */ |
| 729 | |
| 730 | if (from_local || from_dir || |
| 731 | (from_other && (dir_nodeid == our_nodeid))) { |
| 732 | create = 1; |
| 733 | } |
| 734 | |
| 735 | retry: |
| 736 | error = dlm_search_rsb_tree(&ls->ls_rsbtbl, name, len, &r); |
| 737 | if (error) |
| 738 | goto do_new; |
| 739 | |
| 740 | /* check if the rsb is active under read lock - likely path */ |
| 741 | read_lock_bh(&ls->ls_rsbtbl_lock); |
| 742 | if (!rsb_flag(r, RSB_HASHED)) { |
| 743 | read_unlock_bh(&ls->ls_rsbtbl_lock); |
| 744 | goto do_new; |
| 745 | } |
| 746 | |
| 747 | /* |
| 748 | * rsb is active, so we can't check master_nodeid without lock_rsb. |
| 749 | */ |
| 750 | |
| 751 | if (rsb_flag(r, RSB_INACTIVE)) { |
| 752 | read_unlock_bh(&ls->ls_rsbtbl_lock); |
| 753 | goto do_inactive; |
| 754 | } |
| 755 | |
| 756 | kref_get(&r->res_ref); |
| 757 | read_unlock_bh(&ls->ls_rsbtbl_lock); |
| 758 | goto out; |
| 759 | |
| 760 | |
| 761 | do_inactive: |
| 762 | write_lock_bh(&ls->ls_rsbtbl_lock); |
| 763 | |
| 764 | /* |
| 765 | * The expectation here is that the rsb will have HASHED and |
| 766 | * INACTIVE flags set, and that the rsb can be moved from |
| 767 | * inactive back to active again. However, between releasing |
| 768 | * the read lock and acquiring the write lock, this rsb could |
| 769 | * have been removed from rsbtbl, and had HASHED cleared, to |
| 770 | * be freed. To deal with this case, we would normally need |
| 771 | * to repeat dlm_search_rsb_tree while holding the write lock, |
| 772 | * but rcu allows us to simply check the HASHED flag, because |
| 773 | * the rcu read lock means the rsb will not be freed yet. |
| 774 | * If the HASHED flag is not set, then the rsb is being freed, |
| 775 | * so we add a new rsb struct. If the HASHED flag is set, |
| 776 | * and INACTIVE is not set, it means another thread has |
| 777 | * made the rsb active, as we're expecting to do here, and |
| 778 | * we just repeat the lookup (this will be very unlikely.) |
| 779 | */ |
| 780 | if (rsb_flag(r, RSB_HASHED)) { |
| 781 | if (!rsb_flag(r, RSB_INACTIVE)) { |
| 782 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 783 | goto retry; |
| 784 | } |
| 785 | } else { |
| 786 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 787 | goto do_new; |
| 788 | } |
| 789 | |
| 790 | /* |
| 791 | * rsb found inactive (master_nodeid may be out of date unless |
| 792 | * we are the dir_nodeid or were the master) No other thread |
| 793 | * is using this rsb because it's inactive, so we can |
| 794 | * look at or update res_master_nodeid without lock_rsb. |
| 795 | */ |
| 796 | |
| 797 | if ((r->res_master_nodeid != our_nodeid) && from_other) { |
| 798 | /* our rsb was not master, and another node (not the dir node) |
| 799 | has sent us a request */ |
| 800 | log_debug(ls, "find_rsb inactive from_other %d master %d dir %d %s", |
| 801 | from_nodeid, r->res_master_nodeid, dir_nodeid, |
| 802 | r->res_name); |
| 803 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 804 | error = -ENOTBLK; |
| 805 | goto out; |
| 806 | } |
| 807 | |
| 808 | if ((r->res_master_nodeid != our_nodeid) && from_dir) { |
| 809 | /* don't think this should ever happen */ |
| 810 | log_error(ls, "find_rsb inactive from_dir %d master %d", |
| 811 | from_nodeid, r->res_master_nodeid); |
| 812 | dlm_print_rsb(r); |
| 813 | /* fix it and go on */ |
| 814 | r->res_master_nodeid = our_nodeid; |
| 815 | r->res_nodeid = 0; |
| 816 | rsb_clear_flag(r, RSB_MASTER_UNCERTAIN); |
| 817 | r->res_first_lkid = 0; |
| 818 | } |
| 819 | |
| 820 | if (from_local && (r->res_master_nodeid != our_nodeid)) { |
| 821 | /* Because we have held no locks on this rsb, |
| 822 | res_master_nodeid could have become stale. */ |
| 823 | rsb_set_flag(r, RSB_MASTER_UNCERTAIN); |
| 824 | r->res_first_lkid = 0; |
| 825 | } |
| 826 | |
| 827 | /* A dir record will not be on the scan list. */ |
| 828 | if (r->res_dir_nodeid != our_nodeid) |
| 829 | del_scan(ls, r); |
| 830 | list_move(&r->res_slow_list, &ls->ls_slow_active); |
| 831 | rsb_clear_flag(r, RSB_INACTIVE); |
| 832 | kref_init(&r->res_ref); /* ref is now used in active state */ |
| 833 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 834 | |
| 835 | goto out; |
| 836 | |
| 837 | |
| 838 | do_new: |
| 839 | /* |
| 840 | * rsb not found |
| 841 | */ |
| 842 | |
| 843 | if (error == -EBADR && !create) |
| 844 | goto out; |
| 845 | |
| 846 | error = get_rsb_struct(ls, name, len, &r); |
| 847 | if (WARN_ON_ONCE(error)) |
| 848 | goto out; |
| 849 | |
| 850 | r->res_hash = hash; |
| 851 | r->res_dir_nodeid = dir_nodeid; |
| 852 | kref_init(&r->res_ref); |
| 853 | |
| 854 | if (from_dir) { |
| 855 | /* want to see how often this happens */ |
| 856 | log_debug(ls, "find_rsb new from_dir %d recreate %s", |
| 857 | from_nodeid, r->res_name); |
| 858 | r->res_master_nodeid = our_nodeid; |
| 859 | r->res_nodeid = 0; |
| 860 | goto out_add; |
| 861 | } |
| 862 | |
| 863 | if (from_other && (dir_nodeid != our_nodeid)) { |
| 864 | /* should never happen */ |
| 865 | log_error(ls, "find_rsb new from_other %d dir %d our %d %s", |
| 866 | from_nodeid, dir_nodeid, our_nodeid, r->res_name); |
| 867 | dlm_free_rsb(r); |
| 868 | r = NULL; |
| 869 | error = -ENOTBLK; |
| 870 | goto out; |
| 871 | } |
| 872 | |
| 873 | if (from_other) { |
| 874 | log_debug(ls, "find_rsb new from_other %d dir %d %s", |
| 875 | from_nodeid, dir_nodeid, r->res_name); |
| 876 | } |
| 877 | |
| 878 | if (dir_nodeid == our_nodeid) { |
| 879 | /* When we are the dir nodeid, we can set the master |
| 880 | node immediately */ |
| 881 | r->res_master_nodeid = our_nodeid; |
| 882 | r->res_nodeid = 0; |
| 883 | } else { |
| 884 | /* set_master will send_lookup to dir_nodeid */ |
| 885 | r->res_master_nodeid = 0; |
| 886 | r->res_nodeid = -1; |
| 887 | } |
| 888 | |
| 889 | out_add: |
| 890 | |
| 891 | write_lock_bh(&ls->ls_rsbtbl_lock); |
| 892 | error = rsb_insert(r, &ls->ls_rsbtbl); |
| 893 | if (error == -EEXIST) { |
| 894 | /* somebody else was faster and it seems the |
| 895 | * rsb exists now, we do a whole relookup |
| 896 | */ |
| 897 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 898 | dlm_free_rsb(r); |
| 899 | goto retry; |
| 900 | } else if (!error) { |
| 901 | list_add(&r->res_slow_list, &ls->ls_slow_active); |
| 902 | } |
| 903 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 904 | out: |
| 905 | *r_ret = r; |
| 906 | return error; |
| 907 | } |
| 908 | |
| 909 | /* During recovery, other nodes can send us new MSTCPY locks (from |
| 910 | dlm_recover_locks) before we've made ourself master (in |
| 911 | dlm_recover_masters). */ |
| 912 | |
| 913 | static int find_rsb_nodir(struct dlm_ls *ls, const void *name, int len, |
| 914 | uint32_t hash, int dir_nodeid, int from_nodeid, |
| 915 | unsigned int flags, struct dlm_rsb **r_ret) |
| 916 | { |
| 917 | struct dlm_rsb *r = NULL; |
| 918 | int our_nodeid = dlm_our_nodeid(); |
| 919 | int recover = (flags & R_RECEIVE_RECOVER); |
| 920 | int error; |
| 921 | |
| 922 | retry: |
| 923 | error = dlm_search_rsb_tree(&ls->ls_rsbtbl, name, len, &r); |
| 924 | if (error) |
| 925 | goto do_new; |
| 926 | |
| 927 | /* check if the rsb is in active state under read lock - likely path */ |
| 928 | read_lock_bh(&ls->ls_rsbtbl_lock); |
| 929 | if (!rsb_flag(r, RSB_HASHED)) { |
| 930 | read_unlock_bh(&ls->ls_rsbtbl_lock); |
| 931 | goto do_new; |
| 932 | } |
| 933 | |
| 934 | if (rsb_flag(r, RSB_INACTIVE)) { |
| 935 | read_unlock_bh(&ls->ls_rsbtbl_lock); |
| 936 | goto do_inactive; |
| 937 | } |
| 938 | |
| 939 | /* |
| 940 | * rsb is active, so we can't check master_nodeid without lock_rsb. |
| 941 | */ |
| 942 | |
| 943 | kref_get(&r->res_ref); |
| 944 | read_unlock_bh(&ls->ls_rsbtbl_lock); |
| 945 | |
| 946 | goto out; |
| 947 | |
| 948 | |
| 949 | do_inactive: |
| 950 | write_lock_bh(&ls->ls_rsbtbl_lock); |
| 951 | |
| 952 | /* See comment in find_rsb_dir. */ |
| 953 | if (rsb_flag(r, RSB_HASHED)) { |
| 954 | if (!rsb_flag(r, RSB_INACTIVE)) { |
| 955 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 956 | goto retry; |
| 957 | } |
| 958 | } else { |
| 959 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 960 | goto do_new; |
| 961 | } |
| 962 | |
| 963 | |
| 964 | /* |
| 965 | * rsb found inactive. No other thread is using this rsb because |
| 966 | * it's inactive, so we can look at or update res_master_nodeid |
| 967 | * without lock_rsb. |
| 968 | */ |
| 969 | |
| 970 | if (!recover && (r->res_master_nodeid != our_nodeid) && from_nodeid) { |
| 971 | /* our rsb is not master, and another node has sent us a |
| 972 | request; this should never happen */ |
| 973 | log_error(ls, "find_rsb inactive from_nodeid %d master %d dir %d", |
| 974 | from_nodeid, r->res_master_nodeid, dir_nodeid); |
| 975 | dlm_print_rsb(r); |
| 976 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 977 | error = -ENOTBLK; |
| 978 | goto out; |
| 979 | } |
| 980 | |
| 981 | if (!recover && (r->res_master_nodeid != our_nodeid) && |
| 982 | (dir_nodeid == our_nodeid)) { |
| 983 | /* our rsb is not master, and we are dir; may as well fix it; |
| 984 | this should never happen */ |
| 985 | log_error(ls, "find_rsb inactive our %d master %d dir %d", |
| 986 | our_nodeid, r->res_master_nodeid, dir_nodeid); |
| 987 | dlm_print_rsb(r); |
| 988 | r->res_master_nodeid = our_nodeid; |
| 989 | r->res_nodeid = 0; |
| 990 | } |
| 991 | |
| 992 | list_move(&r->res_slow_list, &ls->ls_slow_active); |
| 993 | rsb_clear_flag(r, RSB_INACTIVE); |
| 994 | kref_init(&r->res_ref); |
| 995 | del_scan(ls, r); |
| 996 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 997 | |
| 998 | goto out; |
| 999 | |
| 1000 | |
| 1001 | do_new: |
| 1002 | /* |
| 1003 | * rsb not found |
| 1004 | */ |
| 1005 | |
| 1006 | error = get_rsb_struct(ls, name, len, &r); |
| 1007 | if (WARN_ON_ONCE(error)) |
| 1008 | goto out; |
| 1009 | |
| 1010 | r->res_hash = hash; |
| 1011 | r->res_dir_nodeid = dir_nodeid; |
| 1012 | r->res_master_nodeid = dir_nodeid; |
| 1013 | r->res_nodeid = (dir_nodeid == our_nodeid) ? 0 : dir_nodeid; |
| 1014 | kref_init(&r->res_ref); |
| 1015 | |
| 1016 | write_lock_bh(&ls->ls_rsbtbl_lock); |
| 1017 | error = rsb_insert(r, &ls->ls_rsbtbl); |
| 1018 | if (error == -EEXIST) { |
| 1019 | /* somebody else was faster and it seems the |
| 1020 | * rsb exists now, we do a whole relookup |
| 1021 | */ |
| 1022 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 1023 | dlm_free_rsb(r); |
| 1024 | goto retry; |
| 1025 | } else if (!error) { |
| 1026 | list_add(&r->res_slow_list, &ls->ls_slow_active); |
| 1027 | } |
| 1028 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 1029 | |
| 1030 | out: |
| 1031 | *r_ret = r; |
| 1032 | return error; |
| 1033 | } |
| 1034 | |
| 1035 | /* |
| 1036 | * rsb rcu usage |
| 1037 | * |
| 1038 | * While rcu read lock is held, the rsb cannot be freed, |
| 1039 | * which allows a lookup optimization. |
| 1040 | * |
| 1041 | * Two threads are accessing the same rsb concurrently, |
| 1042 | * the first (A) is trying to use the rsb, the second (B) |
| 1043 | * is trying to free the rsb. |
| 1044 | * |
| 1045 | * thread A thread B |
| 1046 | * (trying to use rsb) (trying to free rsb) |
| 1047 | * |
| 1048 | * A1. rcu read lock |
| 1049 | * A2. rsbtbl read lock |
| 1050 | * A3. look up rsb in rsbtbl |
| 1051 | * A4. rsbtbl read unlock |
| 1052 | * B1. rsbtbl write lock |
| 1053 | * B2. look up rsb in rsbtbl |
| 1054 | * B3. remove rsb from rsbtbl |
| 1055 | * B4. clear rsb HASHED flag |
| 1056 | * B5. rsbtbl write unlock |
| 1057 | * B6. begin freeing rsb using rcu... |
| 1058 | * |
| 1059 | * (rsb is inactive, so try to make it active again) |
| 1060 | * A5. read rsb HASHED flag (safe because rsb is not freed yet) |
| 1061 | * A6. the rsb HASHED flag is not set, which it means the rsb |
| 1062 | * is being removed from rsbtbl and freed, so don't use it. |
| 1063 | * A7. rcu read unlock |
| 1064 | * |
| 1065 | * B7. ...finish freeing rsb using rcu |
| 1066 | * A8. create a new rsb |
| 1067 | * |
| 1068 | * Without the rcu optimization, steps A5-8 would need to do |
| 1069 | * an extra rsbtbl lookup: |
| 1070 | * A5. rsbtbl write lock |
| 1071 | * A6. look up rsb in rsbtbl, not found |
| 1072 | * A7. rsbtbl write unlock |
| 1073 | * A8. create a new rsb |
| 1074 | */ |
| 1075 | |
| 1076 | static int find_rsb(struct dlm_ls *ls, const void *name, int len, |
| 1077 | int from_nodeid, unsigned int flags, |
| 1078 | struct dlm_rsb **r_ret) |
| 1079 | { |
| 1080 | int dir_nodeid; |
| 1081 | uint32_t hash; |
| 1082 | int rv; |
| 1083 | |
| 1084 | if (len > DLM_RESNAME_MAXLEN) |
| 1085 | return -EINVAL; |
| 1086 | |
| 1087 | hash = jhash(name, len, 0); |
| 1088 | dir_nodeid = dlm_hash2nodeid(ls, hash); |
| 1089 | |
| 1090 | rcu_read_lock(); |
| 1091 | if (dlm_no_directory(ls)) |
| 1092 | rv = find_rsb_nodir(ls, name, len, hash, dir_nodeid, |
| 1093 | from_nodeid, flags, r_ret); |
| 1094 | else |
| 1095 | rv = find_rsb_dir(ls, name, len, hash, dir_nodeid, |
| 1096 | from_nodeid, flags, r_ret); |
| 1097 | rcu_read_unlock(); |
| 1098 | return rv; |
| 1099 | } |
| 1100 | |
| 1101 | /* we have received a request and found that res_master_nodeid != our_nodeid, |
| 1102 | so we need to return an error or make ourself the master */ |
| 1103 | |
| 1104 | static int validate_master_nodeid(struct dlm_ls *ls, struct dlm_rsb *r, |
| 1105 | int from_nodeid) |
| 1106 | { |
| 1107 | if (dlm_no_directory(ls)) { |
| 1108 | log_error(ls, "find_rsb keep from_nodeid %d master %d dir %d", |
| 1109 | from_nodeid, r->res_master_nodeid, |
| 1110 | r->res_dir_nodeid); |
| 1111 | dlm_print_rsb(r); |
| 1112 | return -ENOTBLK; |
| 1113 | } |
| 1114 | |
| 1115 | if (from_nodeid != r->res_dir_nodeid) { |
| 1116 | /* our rsb is not master, and another node (not the dir node) |
| 1117 | has sent us a request. this is much more common when our |
| 1118 | master_nodeid is zero, so limit debug to non-zero. */ |
| 1119 | |
| 1120 | if (r->res_master_nodeid) { |
| 1121 | log_debug(ls, "validate master from_other %d master %d " |
| 1122 | "dir %d first %x %s", from_nodeid, |
| 1123 | r->res_master_nodeid, r->res_dir_nodeid, |
| 1124 | r->res_first_lkid, r->res_name); |
| 1125 | } |
| 1126 | return -ENOTBLK; |
| 1127 | } else { |
| 1128 | /* our rsb is not master, but the dir nodeid has sent us a |
| 1129 | request; this could happen with master 0 / res_nodeid -1 */ |
| 1130 | |
| 1131 | if (r->res_master_nodeid) { |
| 1132 | log_error(ls, "validate master from_dir %d master %d " |
| 1133 | "first %x %s", |
| 1134 | from_nodeid, r->res_master_nodeid, |
| 1135 | r->res_first_lkid, r->res_name); |
| 1136 | } |
| 1137 | |
| 1138 | r->res_master_nodeid = dlm_our_nodeid(); |
| 1139 | r->res_nodeid = 0; |
| 1140 | return 0; |
| 1141 | } |
| 1142 | } |
| 1143 | |
| 1144 | static void __dlm_master_lookup(struct dlm_ls *ls, struct dlm_rsb *r, int our_nodeid, |
| 1145 | int from_nodeid, bool is_inactive, unsigned int flags, |
| 1146 | int *r_nodeid, int *result) |
| 1147 | { |
| 1148 | int fix_master = (flags & DLM_LU_RECOVER_MASTER); |
| 1149 | int from_master = (flags & DLM_LU_RECOVER_DIR); |
| 1150 | |
| 1151 | if (r->res_dir_nodeid != our_nodeid) { |
| 1152 | /* should not happen, but may as well fix it and carry on */ |
| 1153 | log_error(ls, "%s res_dir %d our %d %s", __func__, |
| 1154 | r->res_dir_nodeid, our_nodeid, r->res_name); |
| 1155 | r->res_dir_nodeid = our_nodeid; |
| 1156 | } |
| 1157 | |
| 1158 | if (fix_master && r->res_master_nodeid && dlm_is_removed(ls, r->res_master_nodeid)) { |
| 1159 | /* Recovery uses this function to set a new master when |
| 1160 | * the previous master failed. Setting NEW_MASTER will |
| 1161 | * force dlm_recover_masters to call recover_master on this |
| 1162 | * rsb even though the res_nodeid is no longer removed. |
| 1163 | */ |
| 1164 | |
| 1165 | r->res_master_nodeid = from_nodeid; |
| 1166 | r->res_nodeid = from_nodeid; |
| 1167 | rsb_set_flag(r, RSB_NEW_MASTER); |
| 1168 | |
| 1169 | if (is_inactive) { |
| 1170 | /* I don't think we should ever find it inactive. */ |
| 1171 | log_error(ls, "%s fix_master inactive", __func__); |
| 1172 | dlm_dump_rsb(r); |
| 1173 | } |
| 1174 | } |
| 1175 | |
| 1176 | if (from_master && (r->res_master_nodeid != from_nodeid)) { |
| 1177 | /* this will happen if from_nodeid became master during |
| 1178 | * a previous recovery cycle, and we aborted the previous |
| 1179 | * cycle before recovering this master value |
| 1180 | */ |
| 1181 | |
| 1182 | log_limit(ls, "%s from_master %d master_nodeid %d res_nodeid %d first %x %s", |
| 1183 | __func__, from_nodeid, r->res_master_nodeid, |
| 1184 | r->res_nodeid, r->res_first_lkid, r->res_name); |
| 1185 | |
| 1186 | if (r->res_master_nodeid == our_nodeid) { |
| 1187 | log_error(ls, "from_master %d our_master", from_nodeid); |
| 1188 | dlm_dump_rsb(r); |
| 1189 | goto ret_assign; |
| 1190 | } |
| 1191 | |
| 1192 | r->res_master_nodeid = from_nodeid; |
| 1193 | r->res_nodeid = from_nodeid; |
| 1194 | rsb_set_flag(r, RSB_NEW_MASTER); |
| 1195 | } |
| 1196 | |
| 1197 | if (!r->res_master_nodeid) { |
| 1198 | /* this will happen if recovery happens while we're looking |
| 1199 | * up the master for this rsb |
| 1200 | */ |
| 1201 | |
| 1202 | log_debug(ls, "%s master 0 to %d first %x %s", __func__, |
| 1203 | from_nodeid, r->res_first_lkid, r->res_name); |
| 1204 | r->res_master_nodeid = from_nodeid; |
| 1205 | r->res_nodeid = from_nodeid; |
| 1206 | } |
| 1207 | |
| 1208 | if (!from_master && !fix_master && |
| 1209 | (r->res_master_nodeid == from_nodeid)) { |
| 1210 | /* this can happen when the master sends remove, the dir node |
| 1211 | * finds the rsb on the active list and ignores the remove, |
| 1212 | * and the former master sends a lookup |
| 1213 | */ |
| 1214 | |
| 1215 | log_limit(ls, "%s from master %d flags %x first %x %s", |
| 1216 | __func__, from_nodeid, flags, r->res_first_lkid, |
| 1217 | r->res_name); |
| 1218 | } |
| 1219 | |
| 1220 | ret_assign: |
| 1221 | *r_nodeid = r->res_master_nodeid; |
| 1222 | if (result) |
| 1223 | *result = DLM_LU_MATCH; |
| 1224 | } |
| 1225 | |
| 1226 | /* |
| 1227 | * We're the dir node for this res and another node wants to know the |
| 1228 | * master nodeid. During normal operation (non recovery) this is only |
| 1229 | * called from receive_lookup(); master lookups when the local node is |
| 1230 | * the dir node are done by find_rsb(). |
| 1231 | * |
| 1232 | * normal operation, we are the dir node for a resource |
| 1233 | * . _request_lock |
| 1234 | * . set_master |
| 1235 | * . send_lookup |
| 1236 | * . receive_lookup |
| 1237 | * . dlm_master_lookup flags 0 |
| 1238 | * |
| 1239 | * recover directory, we are rebuilding dir for all resources |
| 1240 | * . dlm_recover_directory |
| 1241 | * . dlm_rcom_names |
| 1242 | * remote node sends back the rsb names it is master of and we are dir of |
| 1243 | * . dlm_master_lookup RECOVER_DIR (fix_master 0, from_master 1) |
| 1244 | * we either create new rsb setting remote node as master, or find existing |
| 1245 | * rsb and set master to be the remote node. |
| 1246 | * |
| 1247 | * recover masters, we are finding the new master for resources |
| 1248 | * . dlm_recover_masters |
| 1249 | * . recover_master |
| 1250 | * . dlm_send_rcom_lookup |
| 1251 | * . receive_rcom_lookup |
| 1252 | * . dlm_master_lookup RECOVER_MASTER (fix_master 1, from_master 0) |
| 1253 | */ |
| 1254 | |
| 1255 | static int _dlm_master_lookup(struct dlm_ls *ls, int from_nodeid, const char *name, |
| 1256 | int len, unsigned int flags, int *r_nodeid, int *result) |
| 1257 | { |
| 1258 | struct dlm_rsb *r = NULL; |
| 1259 | uint32_t hash; |
| 1260 | int our_nodeid = dlm_our_nodeid(); |
| 1261 | int dir_nodeid, error; |
| 1262 | |
| 1263 | if (len > DLM_RESNAME_MAXLEN) |
| 1264 | return -EINVAL; |
| 1265 | |
| 1266 | if (from_nodeid == our_nodeid) { |
| 1267 | log_error(ls, "dlm_master_lookup from our_nodeid %d flags %x", |
| 1268 | our_nodeid, flags); |
| 1269 | return -EINVAL; |
| 1270 | } |
| 1271 | |
| 1272 | hash = jhash(name, len, 0); |
| 1273 | dir_nodeid = dlm_hash2nodeid(ls, hash); |
| 1274 | if (dir_nodeid != our_nodeid) { |
| 1275 | log_error(ls, "dlm_master_lookup from %d dir %d our %d h %x %d", |
| 1276 | from_nodeid, dir_nodeid, our_nodeid, hash, |
| 1277 | ls->ls_num_nodes); |
| 1278 | *r_nodeid = -1; |
| 1279 | return -EINVAL; |
| 1280 | } |
| 1281 | |
| 1282 | retry: |
| 1283 | error = dlm_search_rsb_tree(&ls->ls_rsbtbl, name, len, &r); |
| 1284 | if (error) |
| 1285 | goto not_found; |
| 1286 | |
| 1287 | /* check if the rsb is active under read lock - likely path */ |
| 1288 | read_lock_bh(&ls->ls_rsbtbl_lock); |
| 1289 | if (!rsb_flag(r, RSB_HASHED)) { |
| 1290 | read_unlock_bh(&ls->ls_rsbtbl_lock); |
| 1291 | goto not_found; |
| 1292 | } |
| 1293 | |
| 1294 | if (rsb_flag(r, RSB_INACTIVE)) { |
| 1295 | read_unlock_bh(&ls->ls_rsbtbl_lock); |
| 1296 | goto do_inactive; |
| 1297 | } |
| 1298 | |
| 1299 | /* because the rsb is active, we need to lock_rsb before |
| 1300 | * checking/changing re_master_nodeid |
| 1301 | */ |
| 1302 | |
| 1303 | hold_rsb(r); |
| 1304 | read_unlock_bh(&ls->ls_rsbtbl_lock); |
| 1305 | lock_rsb(r); |
| 1306 | |
| 1307 | __dlm_master_lookup(ls, r, our_nodeid, from_nodeid, false, |
| 1308 | flags, r_nodeid, result); |
| 1309 | |
| 1310 | /* the rsb was active */ |
| 1311 | unlock_rsb(r); |
| 1312 | put_rsb(r); |
| 1313 | |
| 1314 | return 0; |
| 1315 | |
| 1316 | do_inactive: |
| 1317 | /* unlikely path - check if still part of ls_rsbtbl */ |
| 1318 | write_lock_bh(&ls->ls_rsbtbl_lock); |
| 1319 | |
| 1320 | /* see comment in find_rsb_dir */ |
| 1321 | if (rsb_flag(r, RSB_HASHED)) { |
| 1322 | if (!rsb_flag(r, RSB_INACTIVE)) { |
| 1323 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 1324 | /* something as changed, very unlikely but |
| 1325 | * try again |
| 1326 | */ |
| 1327 | goto retry; |
| 1328 | } |
| 1329 | } else { |
| 1330 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 1331 | goto not_found; |
| 1332 | } |
| 1333 | |
| 1334 | /* because the rsb is inactive, it's not refcounted and lock_rsb |
| 1335 | is not used, but is protected by the rsbtbl lock */ |
| 1336 | |
| 1337 | __dlm_master_lookup(ls, r, our_nodeid, from_nodeid, true, flags, |
| 1338 | r_nodeid, result); |
| 1339 | |
| 1340 | /* A dir record rsb should never be on scan list. */ |
| 1341 | /* Try to fix this with del_scan? */ |
| 1342 | WARN_ON(!list_empty(&r->res_scan_list)); |
| 1343 | |
| 1344 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 1345 | |
| 1346 | return 0; |
| 1347 | |
| 1348 | not_found: |
| 1349 | error = get_rsb_struct(ls, name, len, &r); |
| 1350 | if (WARN_ON_ONCE(error)) |
| 1351 | goto out; |
| 1352 | |
| 1353 | r->res_hash = hash; |
| 1354 | r->res_dir_nodeid = our_nodeid; |
| 1355 | r->res_master_nodeid = from_nodeid; |
| 1356 | r->res_nodeid = from_nodeid; |
| 1357 | rsb_set_flag(r, RSB_INACTIVE); |
| 1358 | |
| 1359 | write_lock_bh(&ls->ls_rsbtbl_lock); |
| 1360 | error = rsb_insert(r, &ls->ls_rsbtbl); |
| 1361 | if (error == -EEXIST) { |
| 1362 | /* somebody else was faster and it seems the |
| 1363 | * rsb exists now, we do a whole relookup |
| 1364 | */ |
| 1365 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 1366 | dlm_free_rsb(r); |
| 1367 | goto retry; |
| 1368 | } else if (error) { |
| 1369 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 1370 | /* should never happen */ |
| 1371 | dlm_free_rsb(r); |
| 1372 | goto retry; |
| 1373 | } |
| 1374 | |
| 1375 | list_add(&r->res_slow_list, &ls->ls_slow_inactive); |
| 1376 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 1377 | |
| 1378 | if (result) |
| 1379 | *result = DLM_LU_ADD; |
| 1380 | *r_nodeid = from_nodeid; |
| 1381 | out: |
| 1382 | return error; |
| 1383 | } |
| 1384 | |
| 1385 | int dlm_master_lookup(struct dlm_ls *ls, int from_nodeid, const char *name, |
| 1386 | int len, unsigned int flags, int *r_nodeid, int *result) |
| 1387 | { |
| 1388 | int rv; |
| 1389 | rcu_read_lock(); |
| 1390 | rv = _dlm_master_lookup(ls, from_nodeid, name, len, flags, r_nodeid, result); |
| 1391 | rcu_read_unlock(); |
| 1392 | return rv; |
| 1393 | } |
| 1394 | |
| 1395 | static void dlm_dump_rsb_hash(struct dlm_ls *ls, uint32_t hash) |
| 1396 | { |
| 1397 | struct dlm_rsb *r; |
| 1398 | |
| 1399 | read_lock_bh(&ls->ls_rsbtbl_lock); |
| 1400 | list_for_each_entry(r, &ls->ls_slow_active, res_slow_list) { |
| 1401 | if (r->res_hash == hash) |
| 1402 | dlm_dump_rsb(r); |
| 1403 | } |
| 1404 | read_unlock_bh(&ls->ls_rsbtbl_lock); |
| 1405 | } |
| 1406 | |
| 1407 | void dlm_dump_rsb_name(struct dlm_ls *ls, const char *name, int len) |
| 1408 | { |
| 1409 | struct dlm_rsb *r = NULL; |
| 1410 | int error; |
| 1411 | |
| 1412 | rcu_read_lock(); |
| 1413 | error = dlm_search_rsb_tree(&ls->ls_rsbtbl, name, len, &r); |
| 1414 | if (!error) |
| 1415 | goto out; |
| 1416 | |
| 1417 | dlm_dump_rsb(r); |
| 1418 | out: |
| 1419 | rcu_read_unlock(); |
| 1420 | } |
| 1421 | |
| 1422 | static void deactivate_rsb(struct kref *kref) |
| 1423 | { |
| 1424 | struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref); |
| 1425 | struct dlm_ls *ls = r->res_ls; |
| 1426 | int our_nodeid = dlm_our_nodeid(); |
| 1427 | |
| 1428 | DLM_ASSERT(list_empty(&r->res_root_list), dlm_print_rsb(r);); |
| 1429 | rsb_set_flag(r, RSB_INACTIVE); |
| 1430 | list_move(&r->res_slow_list, &ls->ls_slow_inactive); |
| 1431 | |
| 1432 | /* |
| 1433 | * When the rsb becomes unused: |
| 1434 | * - If it's not a dir record for a remote master rsb, |
| 1435 | * then it is put on the scan list to be freed. |
| 1436 | * - If it's a dir record for a remote master rsb, |
| 1437 | * then it is kept in the inactive state until |
| 1438 | * receive_remove() from the master node. |
| 1439 | */ |
| 1440 | if (!dlm_no_directory(ls) && |
| 1441 | (r->res_master_nodeid != our_nodeid) && |
| 1442 | (dlm_dir_nodeid(r) != our_nodeid)) |
| 1443 | add_scan(ls, r); |
| 1444 | |
| 1445 | if (r->res_lvbptr) { |
| 1446 | dlm_free_lvb(r->res_lvbptr); |
| 1447 | r->res_lvbptr = NULL; |
| 1448 | } |
| 1449 | } |
| 1450 | |
| 1451 | void free_inactive_rsb(struct dlm_rsb *r) |
| 1452 | { |
| 1453 | WARN_ON_ONCE(!rsb_flag(r, RSB_INACTIVE)); |
| 1454 | |
| 1455 | DLM_ASSERT(list_empty(&r->res_lookup), dlm_dump_rsb(r);); |
| 1456 | DLM_ASSERT(list_empty(&r->res_grantqueue), dlm_dump_rsb(r);); |
| 1457 | DLM_ASSERT(list_empty(&r->res_convertqueue), dlm_dump_rsb(r);); |
| 1458 | DLM_ASSERT(list_empty(&r->res_waitqueue), dlm_dump_rsb(r);); |
| 1459 | DLM_ASSERT(list_empty(&r->res_root_list), dlm_dump_rsb(r);); |
| 1460 | DLM_ASSERT(list_empty(&r->res_scan_list), dlm_dump_rsb(r);); |
| 1461 | DLM_ASSERT(list_empty(&r->res_recover_list), dlm_dump_rsb(r);); |
| 1462 | DLM_ASSERT(list_empty(&r->res_masters_list), dlm_dump_rsb(r);); |
| 1463 | |
| 1464 | dlm_free_rsb(r); |
| 1465 | } |
| 1466 | |
| 1467 | /* Attaching/detaching lkb's from rsb's is for rsb reference counting. |
| 1468 | The rsb must exist as long as any lkb's for it do. */ |
| 1469 | |
| 1470 | static void attach_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 1471 | { |
| 1472 | hold_rsb(r); |
| 1473 | lkb->lkb_resource = r; |
| 1474 | } |
| 1475 | |
| 1476 | static void detach_lkb(struct dlm_lkb *lkb) |
| 1477 | { |
| 1478 | if (lkb->lkb_resource) { |
| 1479 | put_rsb(lkb->lkb_resource); |
| 1480 | lkb->lkb_resource = NULL; |
| 1481 | } |
| 1482 | } |
| 1483 | |
| 1484 | static int _create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret, |
| 1485 | unsigned long start, unsigned long end) |
| 1486 | { |
| 1487 | struct xa_limit limit; |
| 1488 | struct dlm_lkb *lkb; |
| 1489 | int rv; |
| 1490 | |
| 1491 | limit.max = end; |
| 1492 | limit.min = start; |
| 1493 | |
| 1494 | lkb = dlm_allocate_lkb(); |
| 1495 | if (!lkb) |
| 1496 | return -ENOMEM; |
| 1497 | |
| 1498 | lkb->lkb_last_bast_cb_mode = DLM_LOCK_IV; |
| 1499 | lkb->lkb_last_cast_cb_mode = DLM_LOCK_IV; |
| 1500 | lkb->lkb_last_cb_mode = DLM_LOCK_IV; |
| 1501 | lkb->lkb_nodeid = -1; |
| 1502 | lkb->lkb_grmode = DLM_LOCK_IV; |
| 1503 | kref_init(&lkb->lkb_ref); |
| 1504 | INIT_LIST_HEAD(&lkb->lkb_ownqueue); |
| 1505 | INIT_LIST_HEAD(&lkb->lkb_rsb_lookup); |
| 1506 | |
| 1507 | write_lock_bh(&ls->ls_lkbxa_lock); |
| 1508 | rv = xa_alloc(&ls->ls_lkbxa, &lkb->lkb_id, lkb, limit, GFP_ATOMIC); |
| 1509 | write_unlock_bh(&ls->ls_lkbxa_lock); |
| 1510 | |
| 1511 | if (rv < 0) { |
| 1512 | log_error(ls, "create_lkb xa error %d", rv); |
| 1513 | dlm_free_lkb(lkb); |
| 1514 | return rv; |
| 1515 | } |
| 1516 | |
| 1517 | *lkb_ret = lkb; |
| 1518 | return 0; |
| 1519 | } |
| 1520 | |
| 1521 | static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret) |
| 1522 | { |
| 1523 | return _create_lkb(ls, lkb_ret, 1, ULONG_MAX); |
| 1524 | } |
| 1525 | |
| 1526 | static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret) |
| 1527 | { |
| 1528 | struct dlm_lkb *lkb; |
| 1529 | |
| 1530 | rcu_read_lock(); |
| 1531 | lkb = xa_load(&ls->ls_lkbxa, lkid); |
| 1532 | if (lkb) { |
| 1533 | /* check if lkb is still part of lkbxa under lkbxa_lock as |
| 1534 | * the lkb_ref is tight to the lkbxa data structure, see |
| 1535 | * __put_lkb(). |
| 1536 | */ |
| 1537 | read_lock_bh(&ls->ls_lkbxa_lock); |
| 1538 | if (kref_read(&lkb->lkb_ref)) |
| 1539 | kref_get(&lkb->lkb_ref); |
| 1540 | else |
| 1541 | lkb = NULL; |
| 1542 | read_unlock_bh(&ls->ls_lkbxa_lock); |
| 1543 | } |
| 1544 | rcu_read_unlock(); |
| 1545 | |
| 1546 | *lkb_ret = lkb; |
| 1547 | return lkb ? 0 : -ENOENT; |
| 1548 | } |
| 1549 | |
| 1550 | static void kill_lkb(struct kref *kref) |
| 1551 | { |
| 1552 | struct dlm_lkb *lkb = container_of(kref, struct dlm_lkb, lkb_ref); |
| 1553 | |
| 1554 | /* All work is done after the return from kref_put() so we |
| 1555 | can release the write_lock before the detach_lkb */ |
| 1556 | |
| 1557 | DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb);); |
| 1558 | } |
| 1559 | |
| 1560 | /* __put_lkb() is used when an lkb may not have an rsb attached to |
| 1561 | it so we need to provide the lockspace explicitly */ |
| 1562 | |
| 1563 | static int __put_lkb(struct dlm_ls *ls, struct dlm_lkb *lkb) |
| 1564 | { |
| 1565 | uint32_t lkid = lkb->lkb_id; |
| 1566 | int rv; |
| 1567 | |
| 1568 | rv = dlm_kref_put_write_lock_bh(&lkb->lkb_ref, kill_lkb, |
| 1569 | &ls->ls_lkbxa_lock); |
| 1570 | if (rv) { |
| 1571 | xa_erase(&ls->ls_lkbxa, lkid); |
| 1572 | write_unlock_bh(&ls->ls_lkbxa_lock); |
| 1573 | |
| 1574 | detach_lkb(lkb); |
| 1575 | |
| 1576 | /* for local/process lkbs, lvbptr points to caller's lksb */ |
| 1577 | if (lkb->lkb_lvbptr && is_master_copy(lkb)) |
| 1578 | dlm_free_lvb(lkb->lkb_lvbptr); |
| 1579 | dlm_free_lkb(lkb); |
| 1580 | } |
| 1581 | |
| 1582 | return rv; |
| 1583 | } |
| 1584 | |
| 1585 | int dlm_put_lkb(struct dlm_lkb *lkb) |
| 1586 | { |
| 1587 | struct dlm_ls *ls; |
| 1588 | |
| 1589 | DLM_ASSERT(lkb->lkb_resource, dlm_print_lkb(lkb);); |
| 1590 | DLM_ASSERT(lkb->lkb_resource->res_ls, dlm_print_lkb(lkb);); |
| 1591 | |
| 1592 | ls = lkb->lkb_resource->res_ls; |
| 1593 | return __put_lkb(ls, lkb); |
| 1594 | } |
| 1595 | |
| 1596 | /* This is only called to add a reference when the code already holds |
| 1597 | a valid reference to the lkb, so there's no need for locking. */ |
| 1598 | |
| 1599 | static inline void hold_lkb(struct dlm_lkb *lkb) |
| 1600 | { |
| 1601 | kref_get(&lkb->lkb_ref); |
| 1602 | } |
| 1603 | |
| 1604 | static void unhold_lkb_assert(struct kref *kref) |
| 1605 | { |
| 1606 | struct dlm_lkb *lkb = container_of(kref, struct dlm_lkb, lkb_ref); |
| 1607 | |
| 1608 | DLM_ASSERT(false, dlm_print_lkb(lkb);); |
| 1609 | } |
| 1610 | |
| 1611 | /* This is called when we need to remove a reference and are certain |
| 1612 | it's not the last ref. e.g. del_lkb is always called between a |
| 1613 | find_lkb/put_lkb and is always the inverse of a previous add_lkb. |
| 1614 | put_lkb would work fine, but would involve unnecessary locking */ |
| 1615 | |
| 1616 | static inline void unhold_lkb(struct dlm_lkb *lkb) |
| 1617 | { |
| 1618 | kref_put(&lkb->lkb_ref, unhold_lkb_assert); |
| 1619 | } |
| 1620 | |
| 1621 | static void lkb_add_ordered(struct list_head *new, struct list_head *head, |
| 1622 | int mode) |
| 1623 | { |
| 1624 | struct dlm_lkb *lkb = NULL, *iter; |
| 1625 | |
| 1626 | list_for_each_entry(iter, head, lkb_statequeue) |
| 1627 | if (iter->lkb_rqmode < mode) { |
| 1628 | lkb = iter; |
| 1629 | list_add_tail(new, &iter->lkb_statequeue); |
| 1630 | break; |
| 1631 | } |
| 1632 | |
| 1633 | if (!lkb) |
| 1634 | list_add_tail(new, head); |
| 1635 | } |
| 1636 | |
| 1637 | /* add/remove lkb to rsb's grant/convert/wait queue */ |
| 1638 | |
| 1639 | static void add_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int status) |
| 1640 | { |
| 1641 | kref_get(&lkb->lkb_ref); |
| 1642 | |
| 1643 | DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb);); |
| 1644 | |
| 1645 | lkb->lkb_timestamp = ktime_get(); |
| 1646 | |
| 1647 | lkb->lkb_status = status; |
| 1648 | |
| 1649 | switch (status) { |
| 1650 | case DLM_LKSTS_WAITING: |
| 1651 | if (lkb->lkb_exflags & DLM_LKF_HEADQUE) |
| 1652 | list_add(&lkb->lkb_statequeue, &r->res_waitqueue); |
| 1653 | else |
| 1654 | list_add_tail(&lkb->lkb_statequeue, &r->res_waitqueue); |
| 1655 | break; |
| 1656 | case DLM_LKSTS_GRANTED: |
| 1657 | /* convention says granted locks kept in order of grmode */ |
| 1658 | lkb_add_ordered(&lkb->lkb_statequeue, &r->res_grantqueue, |
| 1659 | lkb->lkb_grmode); |
| 1660 | break; |
| 1661 | case DLM_LKSTS_CONVERT: |
| 1662 | if (lkb->lkb_exflags & DLM_LKF_HEADQUE) |
| 1663 | list_add(&lkb->lkb_statequeue, &r->res_convertqueue); |
| 1664 | else |
| 1665 | list_add_tail(&lkb->lkb_statequeue, |
| 1666 | &r->res_convertqueue); |
| 1667 | break; |
| 1668 | default: |
| 1669 | DLM_ASSERT(0, dlm_print_lkb(lkb); printk("sts=%d\n", status);); |
| 1670 | } |
| 1671 | } |
| 1672 | |
| 1673 | static void del_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 1674 | { |
| 1675 | lkb->lkb_status = 0; |
| 1676 | list_del(&lkb->lkb_statequeue); |
| 1677 | unhold_lkb(lkb); |
| 1678 | } |
| 1679 | |
| 1680 | static void move_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int sts) |
| 1681 | { |
| 1682 | del_lkb(r, lkb); |
| 1683 | add_lkb(r, lkb, sts); |
| 1684 | } |
| 1685 | |
| 1686 | static int msg_reply_type(int mstype) |
| 1687 | { |
| 1688 | switch (mstype) { |
| 1689 | case DLM_MSG_REQUEST: |
| 1690 | return DLM_MSG_REQUEST_REPLY; |
| 1691 | case DLM_MSG_CONVERT: |
| 1692 | return DLM_MSG_CONVERT_REPLY; |
| 1693 | case DLM_MSG_UNLOCK: |
| 1694 | return DLM_MSG_UNLOCK_REPLY; |
| 1695 | case DLM_MSG_CANCEL: |
| 1696 | return DLM_MSG_CANCEL_REPLY; |
| 1697 | case DLM_MSG_LOOKUP: |
| 1698 | return DLM_MSG_LOOKUP_REPLY; |
| 1699 | } |
| 1700 | return -1; |
| 1701 | } |
| 1702 | |
| 1703 | /* add/remove lkb from global waiters list of lkb's waiting for |
| 1704 | a reply from a remote node */ |
| 1705 | |
| 1706 | static int add_to_waiters(struct dlm_lkb *lkb, int mstype, int to_nodeid) |
| 1707 | { |
| 1708 | struct dlm_ls *ls = lkb->lkb_resource->res_ls; |
| 1709 | int error = 0; |
| 1710 | |
| 1711 | spin_lock_bh(&ls->ls_waiters_lock); |
| 1712 | |
| 1713 | if (is_overlap_unlock(lkb) || |
| 1714 | (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL))) { |
| 1715 | error = -EINVAL; |
| 1716 | goto out; |
| 1717 | } |
| 1718 | |
| 1719 | if (lkb->lkb_wait_type || is_overlap_cancel(lkb)) { |
| 1720 | switch (mstype) { |
| 1721 | case DLM_MSG_UNLOCK: |
| 1722 | set_bit(DLM_IFL_OVERLAP_UNLOCK_BIT, &lkb->lkb_iflags); |
| 1723 | break; |
| 1724 | case DLM_MSG_CANCEL: |
| 1725 | set_bit(DLM_IFL_OVERLAP_CANCEL_BIT, &lkb->lkb_iflags); |
| 1726 | break; |
| 1727 | default: |
| 1728 | error = -EBUSY; |
| 1729 | goto out; |
| 1730 | } |
| 1731 | lkb->lkb_wait_count++; |
| 1732 | hold_lkb(lkb); |
| 1733 | |
| 1734 | log_debug(ls, "addwait %x cur %d overlap %d count %d f %x", |
| 1735 | lkb->lkb_id, lkb->lkb_wait_type, mstype, |
| 1736 | lkb->lkb_wait_count, dlm_iflags_val(lkb)); |
| 1737 | goto out; |
| 1738 | } |
| 1739 | |
| 1740 | DLM_ASSERT(!lkb->lkb_wait_count, |
| 1741 | dlm_print_lkb(lkb); |
| 1742 | printk("wait_count %d\n", lkb->lkb_wait_count);); |
| 1743 | |
| 1744 | lkb->lkb_wait_count++; |
| 1745 | lkb->lkb_wait_type = mstype; |
| 1746 | lkb->lkb_wait_nodeid = to_nodeid; /* for debugging */ |
| 1747 | hold_lkb(lkb); |
| 1748 | list_add(&lkb->lkb_wait_reply, &ls->ls_waiters); |
| 1749 | out: |
| 1750 | if (error) |
| 1751 | log_error(ls, "addwait error %x %d flags %x %d %d %s", |
| 1752 | lkb->lkb_id, error, dlm_iflags_val(lkb), mstype, |
| 1753 | lkb->lkb_wait_type, lkb->lkb_resource->res_name); |
| 1754 | spin_unlock_bh(&ls->ls_waiters_lock); |
| 1755 | return error; |
| 1756 | } |
| 1757 | |
| 1758 | /* We clear the RESEND flag because we might be taking an lkb off the waiters |
| 1759 | list as part of process_requestqueue (e.g. a lookup that has an optimized |
| 1760 | request reply on the requestqueue) between dlm_recover_waiters_pre() which |
| 1761 | set RESEND and dlm_recover_waiters_post() */ |
| 1762 | |
| 1763 | static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype, |
| 1764 | const struct dlm_message *ms) |
| 1765 | { |
| 1766 | struct dlm_ls *ls = lkb->lkb_resource->res_ls; |
| 1767 | int overlap_done = 0; |
| 1768 | |
| 1769 | if (mstype == DLM_MSG_UNLOCK_REPLY && |
| 1770 | test_and_clear_bit(DLM_IFL_OVERLAP_UNLOCK_BIT, &lkb->lkb_iflags)) { |
| 1771 | log_debug(ls, "remwait %x unlock_reply overlap", lkb->lkb_id); |
| 1772 | overlap_done = 1; |
| 1773 | goto out_del; |
| 1774 | } |
| 1775 | |
| 1776 | if (mstype == DLM_MSG_CANCEL_REPLY && |
| 1777 | test_and_clear_bit(DLM_IFL_OVERLAP_CANCEL_BIT, &lkb->lkb_iflags)) { |
| 1778 | log_debug(ls, "remwait %x cancel_reply overlap", lkb->lkb_id); |
| 1779 | overlap_done = 1; |
| 1780 | goto out_del; |
| 1781 | } |
| 1782 | |
| 1783 | /* Cancel state was preemptively cleared by a successful convert, |
| 1784 | see next comment, nothing to do. */ |
| 1785 | |
| 1786 | if ((mstype == DLM_MSG_CANCEL_REPLY) && |
| 1787 | (lkb->lkb_wait_type != DLM_MSG_CANCEL)) { |
| 1788 | log_debug(ls, "remwait %x cancel_reply wait_type %d", |
| 1789 | lkb->lkb_id, lkb->lkb_wait_type); |
| 1790 | return -1; |
| 1791 | } |
| 1792 | |
| 1793 | /* Remove for the convert reply, and premptively remove for the |
| 1794 | cancel reply. A convert has been granted while there's still |
| 1795 | an outstanding cancel on it (the cancel is moot and the result |
| 1796 | in the cancel reply should be 0). We preempt the cancel reply |
| 1797 | because the app gets the convert result and then can follow up |
| 1798 | with another op, like convert. This subsequent op would see the |
| 1799 | lingering state of the cancel and fail with -EBUSY. */ |
| 1800 | |
| 1801 | if ((mstype == DLM_MSG_CONVERT_REPLY) && |
| 1802 | (lkb->lkb_wait_type == DLM_MSG_CONVERT) && ms && !ms->m_result && |
| 1803 | test_and_clear_bit(DLM_IFL_OVERLAP_CANCEL_BIT, &lkb->lkb_iflags)) { |
| 1804 | log_debug(ls, "remwait %x convert_reply zap overlap_cancel", |
| 1805 | lkb->lkb_id); |
| 1806 | lkb->lkb_wait_type = 0; |
| 1807 | lkb->lkb_wait_count--; |
| 1808 | unhold_lkb(lkb); |
| 1809 | goto out_del; |
| 1810 | } |
| 1811 | |
| 1812 | /* N.B. type of reply may not always correspond to type of original |
| 1813 | msg due to lookup->request optimization, verify others? */ |
| 1814 | |
| 1815 | if (lkb->lkb_wait_type) { |
| 1816 | lkb->lkb_wait_type = 0; |
| 1817 | goto out_del; |
| 1818 | } |
| 1819 | |
| 1820 | log_error(ls, "remwait error %x remote %d %x msg %d flags %x no wait", |
| 1821 | lkb->lkb_id, ms ? le32_to_cpu(ms->m_header.h_nodeid) : 0, |
| 1822 | lkb->lkb_remid, mstype, dlm_iflags_val(lkb)); |
| 1823 | return -1; |
| 1824 | |
| 1825 | out_del: |
| 1826 | /* the force-unlock/cancel has completed and we haven't recvd a reply |
| 1827 | to the op that was in progress prior to the unlock/cancel; we |
| 1828 | give up on any reply to the earlier op. FIXME: not sure when/how |
| 1829 | this would happen */ |
| 1830 | |
| 1831 | if (overlap_done && lkb->lkb_wait_type) { |
| 1832 | log_error(ls, "remwait error %x reply %d wait_type %d overlap", |
| 1833 | lkb->lkb_id, mstype, lkb->lkb_wait_type); |
| 1834 | lkb->lkb_wait_count--; |
| 1835 | unhold_lkb(lkb); |
| 1836 | lkb->lkb_wait_type = 0; |
| 1837 | } |
| 1838 | |
| 1839 | DLM_ASSERT(lkb->lkb_wait_count, dlm_print_lkb(lkb);); |
| 1840 | |
| 1841 | clear_bit(DLM_IFL_RESEND_BIT, &lkb->lkb_iflags); |
| 1842 | lkb->lkb_wait_count--; |
| 1843 | if (!lkb->lkb_wait_count) |
| 1844 | list_del_init(&lkb->lkb_wait_reply); |
| 1845 | unhold_lkb(lkb); |
| 1846 | return 0; |
| 1847 | } |
| 1848 | |
| 1849 | static int remove_from_waiters(struct dlm_lkb *lkb, int mstype) |
| 1850 | { |
| 1851 | struct dlm_ls *ls = lkb->lkb_resource->res_ls; |
| 1852 | int error; |
| 1853 | |
| 1854 | spin_lock_bh(&ls->ls_waiters_lock); |
| 1855 | error = _remove_from_waiters(lkb, mstype, NULL); |
| 1856 | spin_unlock_bh(&ls->ls_waiters_lock); |
| 1857 | return error; |
| 1858 | } |
| 1859 | |
| 1860 | /* Handles situations where we might be processing a "fake" or "local" reply in |
| 1861 | * the recovery context which stops any locking activity. Only debugfs might |
| 1862 | * change the lockspace waiters but they will held the recovery lock to ensure |
| 1863 | * remove_from_waiters_ms() in local case will be the only user manipulating the |
| 1864 | * lockspace waiters in recovery context. |
| 1865 | */ |
| 1866 | |
| 1867 | static int remove_from_waiters_ms(struct dlm_lkb *lkb, |
| 1868 | const struct dlm_message *ms, bool local) |
| 1869 | { |
| 1870 | struct dlm_ls *ls = lkb->lkb_resource->res_ls; |
| 1871 | int error; |
| 1872 | |
| 1873 | if (!local) |
| 1874 | spin_lock_bh(&ls->ls_waiters_lock); |
| 1875 | else |
| 1876 | WARN_ON_ONCE(!rwsem_is_locked(&ls->ls_in_recovery) || |
| 1877 | !dlm_locking_stopped(ls)); |
| 1878 | error = _remove_from_waiters(lkb, le32_to_cpu(ms->m_type), ms); |
| 1879 | if (!local) |
| 1880 | spin_unlock_bh(&ls->ls_waiters_lock); |
| 1881 | return error; |
| 1882 | } |
| 1883 | |
| 1884 | /* lkb is master or local copy */ |
| 1885 | |
| 1886 | static void set_lvb_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 1887 | { |
| 1888 | int b, len = r->res_ls->ls_lvblen; |
| 1889 | |
| 1890 | /* b=1 lvb returned to caller |
| 1891 | b=0 lvb written to rsb or invalidated |
| 1892 | b=-1 do nothing */ |
| 1893 | |
| 1894 | b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1]; |
| 1895 | |
| 1896 | if (b == 1) { |
| 1897 | if (!lkb->lkb_lvbptr) |
| 1898 | return; |
| 1899 | |
| 1900 | if (!(lkb->lkb_exflags & DLM_LKF_VALBLK)) |
| 1901 | return; |
| 1902 | |
| 1903 | if (!r->res_lvbptr) |
| 1904 | return; |
| 1905 | |
| 1906 | memcpy(lkb->lkb_lvbptr, r->res_lvbptr, len); |
| 1907 | lkb->lkb_lvbseq = r->res_lvbseq; |
| 1908 | |
| 1909 | } else if (b == 0) { |
| 1910 | if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) { |
| 1911 | rsb_set_flag(r, RSB_VALNOTVALID); |
| 1912 | return; |
| 1913 | } |
| 1914 | |
| 1915 | if (!lkb->lkb_lvbptr) |
| 1916 | return; |
| 1917 | |
| 1918 | if (!(lkb->lkb_exflags & DLM_LKF_VALBLK)) |
| 1919 | return; |
| 1920 | |
| 1921 | if (!r->res_lvbptr) |
| 1922 | r->res_lvbptr = dlm_allocate_lvb(r->res_ls); |
| 1923 | |
| 1924 | if (!r->res_lvbptr) |
| 1925 | return; |
| 1926 | |
| 1927 | memcpy(r->res_lvbptr, lkb->lkb_lvbptr, len); |
| 1928 | r->res_lvbseq++; |
| 1929 | lkb->lkb_lvbseq = r->res_lvbseq; |
| 1930 | rsb_clear_flag(r, RSB_VALNOTVALID); |
| 1931 | } |
| 1932 | |
| 1933 | if (rsb_flag(r, RSB_VALNOTVALID)) |
| 1934 | set_bit(DLM_SBF_VALNOTVALID_BIT, &lkb->lkb_sbflags); |
| 1935 | } |
| 1936 | |
| 1937 | static void set_lvb_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 1938 | { |
| 1939 | if (lkb->lkb_grmode < DLM_LOCK_PW) |
| 1940 | return; |
| 1941 | |
| 1942 | if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) { |
| 1943 | rsb_set_flag(r, RSB_VALNOTVALID); |
| 1944 | return; |
| 1945 | } |
| 1946 | |
| 1947 | if (!lkb->lkb_lvbptr) |
| 1948 | return; |
| 1949 | |
| 1950 | if (!(lkb->lkb_exflags & DLM_LKF_VALBLK)) |
| 1951 | return; |
| 1952 | |
| 1953 | if (!r->res_lvbptr) |
| 1954 | r->res_lvbptr = dlm_allocate_lvb(r->res_ls); |
| 1955 | |
| 1956 | if (!r->res_lvbptr) |
| 1957 | return; |
| 1958 | |
| 1959 | memcpy(r->res_lvbptr, lkb->lkb_lvbptr, r->res_ls->ls_lvblen); |
| 1960 | r->res_lvbseq++; |
| 1961 | rsb_clear_flag(r, RSB_VALNOTVALID); |
| 1962 | } |
| 1963 | |
| 1964 | /* lkb is process copy (pc) */ |
| 1965 | |
| 1966 | static void set_lvb_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb, |
| 1967 | const struct dlm_message *ms) |
| 1968 | { |
| 1969 | int b; |
| 1970 | |
| 1971 | if (!lkb->lkb_lvbptr) |
| 1972 | return; |
| 1973 | |
| 1974 | if (!(lkb->lkb_exflags & DLM_LKF_VALBLK)) |
| 1975 | return; |
| 1976 | |
| 1977 | b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1]; |
| 1978 | if (b == 1) { |
| 1979 | int len = receive_extralen(ms); |
| 1980 | if (len > r->res_ls->ls_lvblen) |
| 1981 | len = r->res_ls->ls_lvblen; |
| 1982 | memcpy(lkb->lkb_lvbptr, ms->m_extra, len); |
| 1983 | lkb->lkb_lvbseq = le32_to_cpu(ms->m_lvbseq); |
| 1984 | } |
| 1985 | } |
| 1986 | |
| 1987 | /* Manipulate lkb's on rsb's convert/granted/waiting queues |
| 1988 | remove_lock -- used for unlock, removes lkb from granted |
| 1989 | revert_lock -- used for cancel, moves lkb from convert to granted |
| 1990 | grant_lock -- used for request and convert, adds lkb to granted or |
| 1991 | moves lkb from convert or waiting to granted |
| 1992 | |
| 1993 | Each of these is used for master or local copy lkb's. There is |
| 1994 | also a _pc() variation used to make the corresponding change on |
| 1995 | a process copy (pc) lkb. */ |
| 1996 | |
| 1997 | static void _remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 1998 | { |
| 1999 | del_lkb(r, lkb); |
| 2000 | lkb->lkb_grmode = DLM_LOCK_IV; |
| 2001 | /* this unhold undoes the original ref from create_lkb() |
| 2002 | so this leads to the lkb being freed */ |
| 2003 | unhold_lkb(lkb); |
| 2004 | } |
| 2005 | |
| 2006 | static void remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 2007 | { |
| 2008 | set_lvb_unlock(r, lkb); |
| 2009 | _remove_lock(r, lkb); |
| 2010 | } |
| 2011 | |
| 2012 | static void remove_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 2013 | { |
| 2014 | _remove_lock(r, lkb); |
| 2015 | } |
| 2016 | |
| 2017 | /* returns: 0 did nothing |
| 2018 | 1 moved lock to granted |
| 2019 | -1 removed lock */ |
| 2020 | |
| 2021 | static int revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 2022 | { |
| 2023 | int rv = 0; |
| 2024 | |
| 2025 | lkb->lkb_rqmode = DLM_LOCK_IV; |
| 2026 | |
| 2027 | switch (lkb->lkb_status) { |
| 2028 | case DLM_LKSTS_GRANTED: |
| 2029 | break; |
| 2030 | case DLM_LKSTS_CONVERT: |
| 2031 | move_lkb(r, lkb, DLM_LKSTS_GRANTED); |
| 2032 | rv = 1; |
| 2033 | break; |
| 2034 | case DLM_LKSTS_WAITING: |
| 2035 | del_lkb(r, lkb); |
| 2036 | lkb->lkb_grmode = DLM_LOCK_IV; |
| 2037 | /* this unhold undoes the original ref from create_lkb() |
| 2038 | so this leads to the lkb being freed */ |
| 2039 | unhold_lkb(lkb); |
| 2040 | rv = -1; |
| 2041 | break; |
| 2042 | default: |
| 2043 | log_print("invalid status for revert %d", lkb->lkb_status); |
| 2044 | } |
| 2045 | return rv; |
| 2046 | } |
| 2047 | |
| 2048 | static int revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 2049 | { |
| 2050 | return revert_lock(r, lkb); |
| 2051 | } |
| 2052 | |
| 2053 | static void _grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 2054 | { |
| 2055 | if (lkb->lkb_grmode != lkb->lkb_rqmode) { |
| 2056 | lkb->lkb_grmode = lkb->lkb_rqmode; |
| 2057 | if (lkb->lkb_status) |
| 2058 | move_lkb(r, lkb, DLM_LKSTS_GRANTED); |
| 2059 | else |
| 2060 | add_lkb(r, lkb, DLM_LKSTS_GRANTED); |
| 2061 | } |
| 2062 | |
| 2063 | lkb->lkb_rqmode = DLM_LOCK_IV; |
| 2064 | lkb->lkb_highbast = 0; |
| 2065 | } |
| 2066 | |
| 2067 | static void grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 2068 | { |
| 2069 | set_lvb_lock(r, lkb); |
| 2070 | _grant_lock(r, lkb); |
| 2071 | } |
| 2072 | |
| 2073 | static void grant_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb, |
| 2074 | const struct dlm_message *ms) |
| 2075 | { |
| 2076 | set_lvb_lock_pc(r, lkb, ms); |
| 2077 | _grant_lock(r, lkb); |
| 2078 | } |
| 2079 | |
| 2080 | /* called by grant_pending_locks() which means an async grant message must |
| 2081 | be sent to the requesting node in addition to granting the lock if the |
| 2082 | lkb belongs to a remote node. */ |
| 2083 | |
| 2084 | static void grant_lock_pending(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 2085 | { |
| 2086 | grant_lock(r, lkb); |
| 2087 | if (is_master_copy(lkb)) |
| 2088 | send_grant(r, lkb); |
| 2089 | else |
| 2090 | queue_cast(r, lkb, 0); |
| 2091 | } |
| 2092 | |
| 2093 | /* The special CONVDEADLK, ALTPR and ALTCW flags allow the master to |
| 2094 | change the granted/requested modes. We're munging things accordingly in |
| 2095 | the process copy. |
| 2096 | CONVDEADLK: our grmode may have been forced down to NL to resolve a |
| 2097 | conversion deadlock |
| 2098 | ALTPR/ALTCW: our rqmode may have been changed to PR or CW to become |
| 2099 | compatible with other granted locks */ |
| 2100 | |
| 2101 | static void munge_demoted(struct dlm_lkb *lkb) |
| 2102 | { |
| 2103 | if (lkb->lkb_rqmode == DLM_LOCK_IV || lkb->lkb_grmode == DLM_LOCK_IV) { |
| 2104 | log_print("munge_demoted %x invalid modes gr %d rq %d", |
| 2105 | lkb->lkb_id, lkb->lkb_grmode, lkb->lkb_rqmode); |
| 2106 | return; |
| 2107 | } |
| 2108 | |
| 2109 | lkb->lkb_grmode = DLM_LOCK_NL; |
| 2110 | } |
| 2111 | |
| 2112 | static void munge_altmode(struct dlm_lkb *lkb, const struct dlm_message *ms) |
| 2113 | { |
| 2114 | if (ms->m_type != cpu_to_le32(DLM_MSG_REQUEST_REPLY) && |
| 2115 | ms->m_type != cpu_to_le32(DLM_MSG_GRANT)) { |
| 2116 | log_print("munge_altmode %x invalid reply type %d", |
| 2117 | lkb->lkb_id, le32_to_cpu(ms->m_type)); |
| 2118 | return; |
| 2119 | } |
| 2120 | |
| 2121 | if (lkb->lkb_exflags & DLM_LKF_ALTPR) |
| 2122 | lkb->lkb_rqmode = DLM_LOCK_PR; |
| 2123 | else if (lkb->lkb_exflags & DLM_LKF_ALTCW) |
| 2124 | lkb->lkb_rqmode = DLM_LOCK_CW; |
| 2125 | else { |
| 2126 | log_print("munge_altmode invalid exflags %x", lkb->lkb_exflags); |
| 2127 | dlm_print_lkb(lkb); |
| 2128 | } |
| 2129 | } |
| 2130 | |
| 2131 | static inline int first_in_list(struct dlm_lkb *lkb, struct list_head *head) |
| 2132 | { |
| 2133 | struct dlm_lkb *first = list_entry(head->next, struct dlm_lkb, |
| 2134 | lkb_statequeue); |
| 2135 | if (lkb->lkb_id == first->lkb_id) |
| 2136 | return 1; |
| 2137 | |
| 2138 | return 0; |
| 2139 | } |
| 2140 | |
| 2141 | /* Check if the given lkb conflicts with another lkb on the queue. */ |
| 2142 | |
| 2143 | static int queue_conflict(struct list_head *head, struct dlm_lkb *lkb) |
| 2144 | { |
| 2145 | struct dlm_lkb *this; |
| 2146 | |
| 2147 | list_for_each_entry(this, head, lkb_statequeue) { |
| 2148 | if (this == lkb) |
| 2149 | continue; |
| 2150 | if (!modes_compat(this, lkb)) |
| 2151 | return 1; |
| 2152 | } |
| 2153 | return 0; |
| 2154 | } |
| 2155 | |
| 2156 | /* |
| 2157 | * "A conversion deadlock arises with a pair of lock requests in the converting |
| 2158 | * queue for one resource. The granted mode of each lock blocks the requested |
| 2159 | * mode of the other lock." |
| 2160 | * |
| 2161 | * Part 2: if the granted mode of lkb is preventing an earlier lkb in the |
| 2162 | * convert queue from being granted, then deadlk/demote lkb. |
| 2163 | * |
| 2164 | * Example: |
| 2165 | * Granted Queue: empty |
| 2166 | * Convert Queue: NL->EX (first lock) |
| 2167 | * PR->EX (second lock) |
| 2168 | * |
| 2169 | * The first lock can't be granted because of the granted mode of the second |
| 2170 | * lock and the second lock can't be granted because it's not first in the |
| 2171 | * list. We either cancel lkb's conversion (PR->EX) and return EDEADLK, or we |
| 2172 | * demote the granted mode of lkb (from PR to NL) if it has the CONVDEADLK |
| 2173 | * flag set and return DEMOTED in the lksb flags. |
| 2174 | * |
| 2175 | * Originally, this function detected conv-deadlk in a more limited scope: |
| 2176 | * - if !modes_compat(lkb1, lkb2) && !modes_compat(lkb2, lkb1), or |
| 2177 | * - if lkb1 was the first entry in the queue (not just earlier), and was |
| 2178 | * blocked by the granted mode of lkb2, and there was nothing on the |
| 2179 | * granted queue preventing lkb1 from being granted immediately, i.e. |
| 2180 | * lkb2 was the only thing preventing lkb1 from being granted. |
| 2181 | * |
| 2182 | * That second condition meant we'd only say there was conv-deadlk if |
| 2183 | * resolving it (by demotion) would lead to the first lock on the convert |
| 2184 | * queue being granted right away. It allowed conversion deadlocks to exist |
| 2185 | * between locks on the convert queue while they couldn't be granted anyway. |
| 2186 | * |
| 2187 | * Now, we detect and take action on conversion deadlocks immediately when |
| 2188 | * they're created, even if they may not be immediately consequential. If |
| 2189 | * lkb1 exists anywhere in the convert queue and lkb2 comes in with a granted |
| 2190 | * mode that would prevent lkb1's conversion from being granted, we do a |
| 2191 | * deadlk/demote on lkb2 right away and don't let it onto the convert queue. |
| 2192 | * I think this means that the lkb_is_ahead condition below should always |
| 2193 | * be zero, i.e. there will never be conv-deadlk between two locks that are |
| 2194 | * both already on the convert queue. |
| 2195 | */ |
| 2196 | |
| 2197 | static int conversion_deadlock_detect(struct dlm_rsb *r, struct dlm_lkb *lkb2) |
| 2198 | { |
| 2199 | struct dlm_lkb *lkb1; |
| 2200 | int lkb_is_ahead = 0; |
| 2201 | |
| 2202 | list_for_each_entry(lkb1, &r->res_convertqueue, lkb_statequeue) { |
| 2203 | if (lkb1 == lkb2) { |
| 2204 | lkb_is_ahead = 1; |
| 2205 | continue; |
| 2206 | } |
| 2207 | |
| 2208 | if (!lkb_is_ahead) { |
| 2209 | if (!modes_compat(lkb2, lkb1)) |
| 2210 | return 1; |
| 2211 | } else { |
| 2212 | if (!modes_compat(lkb2, lkb1) && |
| 2213 | !modes_compat(lkb1, lkb2)) |
| 2214 | return 1; |
| 2215 | } |
| 2216 | } |
| 2217 | return 0; |
| 2218 | } |
| 2219 | |
| 2220 | /* |
| 2221 | * Return 1 if the lock can be granted, 0 otherwise. |
| 2222 | * Also detect and resolve conversion deadlocks. |
| 2223 | * |
| 2224 | * lkb is the lock to be granted |
| 2225 | * |
| 2226 | * now is 1 if the function is being called in the context of the |
| 2227 | * immediate request, it is 0 if called later, after the lock has been |
| 2228 | * queued. |
| 2229 | * |
| 2230 | * recover is 1 if dlm_recover_grant() is trying to grant conversions |
| 2231 | * after recovery. |
| 2232 | * |
| 2233 | * References are from chapter 6 of "VAXcluster Principles" by Roy Davis |
| 2234 | */ |
| 2235 | |
| 2236 | static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now, |
| 2237 | int recover) |
| 2238 | { |
| 2239 | int8_t conv = (lkb->lkb_grmode != DLM_LOCK_IV); |
| 2240 | |
| 2241 | /* |
| 2242 | * 6-10: Version 5.4 introduced an option to address the phenomenon of |
| 2243 | * a new request for a NL mode lock being blocked. |
| 2244 | * |
| 2245 | * 6-11: If the optional EXPEDITE flag is used with the new NL mode |
| 2246 | * request, then it would be granted. In essence, the use of this flag |
| 2247 | * tells the Lock Manager to expedite theis request by not considering |
| 2248 | * what may be in the CONVERTING or WAITING queues... As of this |
| 2249 | * writing, the EXPEDITE flag can be used only with new requests for NL |
| 2250 | * mode locks. This flag is not valid for conversion requests. |
| 2251 | * |
| 2252 | * A shortcut. Earlier checks return an error if EXPEDITE is used in a |
| 2253 | * conversion or used with a non-NL requested mode. We also know an |
| 2254 | * EXPEDITE request is always granted immediately, so now must always |
| 2255 | * be 1. The full condition to grant an expedite request: (now && |
| 2256 | * !conv && lkb->rqmode == DLM_LOCK_NL && (flags & EXPEDITE)) can |
| 2257 | * therefore be shortened to just checking the flag. |
| 2258 | */ |
| 2259 | |
| 2260 | if (lkb->lkb_exflags & DLM_LKF_EXPEDITE) |
| 2261 | return 1; |
| 2262 | |
| 2263 | /* |
| 2264 | * A shortcut. Without this, !queue_conflict(grantqueue, lkb) would be |
| 2265 | * added to the remaining conditions. |
| 2266 | */ |
| 2267 | |
| 2268 | if (queue_conflict(&r->res_grantqueue, lkb)) |
| 2269 | return 0; |
| 2270 | |
| 2271 | /* |
| 2272 | * 6-3: By default, a conversion request is immediately granted if the |
| 2273 | * requested mode is compatible with the modes of all other granted |
| 2274 | * locks |
| 2275 | */ |
| 2276 | |
| 2277 | if (queue_conflict(&r->res_convertqueue, lkb)) |
| 2278 | return 0; |
| 2279 | |
| 2280 | /* |
| 2281 | * The RECOVER_GRANT flag means dlm_recover_grant() is granting |
| 2282 | * locks for a recovered rsb, on which lkb's have been rebuilt. |
| 2283 | * The lkb's may have been rebuilt on the queues in a different |
| 2284 | * order than they were in on the previous master. So, granting |
| 2285 | * queued conversions in order after recovery doesn't make sense |
| 2286 | * since the order hasn't been preserved anyway. The new order |
| 2287 | * could also have created a new "in place" conversion deadlock. |
| 2288 | * (e.g. old, failed master held granted EX, with PR->EX, NL->EX. |
| 2289 | * After recovery, there would be no granted locks, and possibly |
| 2290 | * NL->EX, PR->EX, an in-place conversion deadlock.) So, after |
| 2291 | * recovery, grant conversions without considering order. |
| 2292 | */ |
| 2293 | |
| 2294 | if (conv && recover) |
| 2295 | return 1; |
| 2296 | |
| 2297 | /* |
| 2298 | * 6-5: But the default algorithm for deciding whether to grant or |
| 2299 | * queue conversion requests does not by itself guarantee that such |
| 2300 | * requests are serviced on a "first come first serve" basis. This, in |
| 2301 | * turn, can lead to a phenomenon known as "indefinate postponement". |
| 2302 | * |
| 2303 | * 6-7: This issue is dealt with by using the optional QUECVT flag with |
| 2304 | * the system service employed to request a lock conversion. This flag |
| 2305 | * forces certain conversion requests to be queued, even if they are |
| 2306 | * compatible with the granted modes of other locks on the same |
| 2307 | * resource. Thus, the use of this flag results in conversion requests |
| 2308 | * being ordered on a "first come first servce" basis. |
| 2309 | * |
| 2310 | * DCT: This condition is all about new conversions being able to occur |
| 2311 | * "in place" while the lock remains on the granted queue (assuming |
| 2312 | * nothing else conflicts.) IOW if QUECVT isn't set, a conversion |
| 2313 | * doesn't _have_ to go onto the convert queue where it's processed in |
| 2314 | * order. The "now" variable is necessary to distinguish converts |
| 2315 | * being received and processed for the first time now, because once a |
| 2316 | * convert is moved to the conversion queue the condition below applies |
| 2317 | * requiring fifo granting. |
| 2318 | */ |
| 2319 | |
| 2320 | if (now && conv && !(lkb->lkb_exflags & DLM_LKF_QUECVT)) |
| 2321 | return 1; |
| 2322 | |
| 2323 | /* |
| 2324 | * Even if the convert is compat with all granted locks, |
| 2325 | * QUECVT forces it behind other locks on the convert queue. |
| 2326 | */ |
| 2327 | |
| 2328 | if (now && conv && (lkb->lkb_exflags & DLM_LKF_QUECVT)) { |
| 2329 | if (list_empty(&r->res_convertqueue)) |
| 2330 | return 1; |
| 2331 | else |
| 2332 | return 0; |
| 2333 | } |
| 2334 | |
| 2335 | /* |
| 2336 | * The NOORDER flag is set to avoid the standard vms rules on grant |
| 2337 | * order. |
| 2338 | */ |
| 2339 | |
| 2340 | if (lkb->lkb_exflags & DLM_LKF_NOORDER) |
| 2341 | return 1; |
| 2342 | |
| 2343 | /* |
| 2344 | * 6-3: Once in that queue [CONVERTING], a conversion request cannot be |
| 2345 | * granted until all other conversion requests ahead of it are granted |
| 2346 | * and/or canceled. |
| 2347 | */ |
| 2348 | |
| 2349 | if (!now && conv && first_in_list(lkb, &r->res_convertqueue)) |
| 2350 | return 1; |
| 2351 | |
| 2352 | /* |
| 2353 | * 6-4: By default, a new request is immediately granted only if all |
| 2354 | * three of the following conditions are satisfied when the request is |
| 2355 | * issued: |
| 2356 | * - The queue of ungranted conversion requests for the resource is |
| 2357 | * empty. |
| 2358 | * - The queue of ungranted new requests for the resource is empty. |
| 2359 | * - The mode of the new request is compatible with the most |
| 2360 | * restrictive mode of all granted locks on the resource. |
| 2361 | */ |
| 2362 | |
| 2363 | if (now && !conv && list_empty(&r->res_convertqueue) && |
| 2364 | list_empty(&r->res_waitqueue)) |
| 2365 | return 1; |
| 2366 | |
| 2367 | /* |
| 2368 | * 6-4: Once a lock request is in the queue of ungranted new requests, |
| 2369 | * it cannot be granted until the queue of ungranted conversion |
| 2370 | * requests is empty, all ungranted new requests ahead of it are |
| 2371 | * granted and/or canceled, and it is compatible with the granted mode |
| 2372 | * of the most restrictive lock granted on the resource. |
| 2373 | */ |
| 2374 | |
| 2375 | if (!now && !conv && list_empty(&r->res_convertqueue) && |
| 2376 | first_in_list(lkb, &r->res_waitqueue)) |
| 2377 | return 1; |
| 2378 | |
| 2379 | return 0; |
| 2380 | } |
| 2381 | |
| 2382 | static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now, |
| 2383 | int recover, int *err) |
| 2384 | { |
| 2385 | int rv; |
| 2386 | int8_t alt = 0, rqmode = lkb->lkb_rqmode; |
| 2387 | int8_t is_convert = (lkb->lkb_grmode != DLM_LOCK_IV); |
| 2388 | |
| 2389 | if (err) |
| 2390 | *err = 0; |
| 2391 | |
| 2392 | rv = _can_be_granted(r, lkb, now, recover); |
| 2393 | if (rv) |
| 2394 | goto out; |
| 2395 | |
| 2396 | /* |
| 2397 | * The CONVDEADLK flag is non-standard and tells the dlm to resolve |
| 2398 | * conversion deadlocks by demoting grmode to NL, otherwise the dlm |
| 2399 | * cancels one of the locks. |
| 2400 | */ |
| 2401 | |
| 2402 | if (is_convert && can_be_queued(lkb) && |
| 2403 | conversion_deadlock_detect(r, lkb)) { |
| 2404 | if (lkb->lkb_exflags & DLM_LKF_CONVDEADLK) { |
| 2405 | lkb->lkb_grmode = DLM_LOCK_NL; |
| 2406 | set_bit(DLM_SBF_DEMOTED_BIT, &lkb->lkb_sbflags); |
| 2407 | } else if (err) { |
| 2408 | *err = -EDEADLK; |
| 2409 | } else { |
| 2410 | log_print("can_be_granted deadlock %x now %d", |
| 2411 | lkb->lkb_id, now); |
| 2412 | dlm_dump_rsb(r); |
| 2413 | } |
| 2414 | goto out; |
| 2415 | } |
| 2416 | |
| 2417 | /* |
| 2418 | * The ALTPR and ALTCW flags are non-standard and tell the dlm to try |
| 2419 | * to grant a request in a mode other than the normal rqmode. It's a |
| 2420 | * simple way to provide a big optimization to applications that can |
| 2421 | * use them. |
| 2422 | */ |
| 2423 | |
| 2424 | if (rqmode != DLM_LOCK_PR && (lkb->lkb_exflags & DLM_LKF_ALTPR)) |
| 2425 | alt = DLM_LOCK_PR; |
| 2426 | else if (rqmode != DLM_LOCK_CW && (lkb->lkb_exflags & DLM_LKF_ALTCW)) |
| 2427 | alt = DLM_LOCK_CW; |
| 2428 | |
| 2429 | if (alt) { |
| 2430 | lkb->lkb_rqmode = alt; |
| 2431 | rv = _can_be_granted(r, lkb, now, 0); |
| 2432 | if (rv) |
| 2433 | set_bit(DLM_SBF_ALTMODE_BIT, &lkb->lkb_sbflags); |
| 2434 | else |
| 2435 | lkb->lkb_rqmode = rqmode; |
| 2436 | } |
| 2437 | out: |
| 2438 | return rv; |
| 2439 | } |
| 2440 | |
| 2441 | /* Returns the highest requested mode of all blocked conversions; sets |
| 2442 | cw if there's a blocked conversion to DLM_LOCK_CW. */ |
| 2443 | |
| 2444 | static int grant_pending_convert(struct dlm_rsb *r, int high, int *cw, |
| 2445 | unsigned int *count) |
| 2446 | { |
| 2447 | struct dlm_lkb *lkb, *s; |
| 2448 | int recover = rsb_flag(r, RSB_RECOVER_GRANT); |
| 2449 | int hi, demoted, quit, grant_restart, demote_restart; |
| 2450 | int deadlk; |
| 2451 | |
| 2452 | quit = 0; |
| 2453 | restart: |
| 2454 | grant_restart = 0; |
| 2455 | demote_restart = 0; |
| 2456 | hi = DLM_LOCK_IV; |
| 2457 | |
| 2458 | list_for_each_entry_safe(lkb, s, &r->res_convertqueue, lkb_statequeue) { |
| 2459 | demoted = is_demoted(lkb); |
| 2460 | deadlk = 0; |
| 2461 | |
| 2462 | if (can_be_granted(r, lkb, 0, recover, &deadlk)) { |
| 2463 | grant_lock_pending(r, lkb); |
| 2464 | grant_restart = 1; |
| 2465 | if (count) |
| 2466 | (*count)++; |
| 2467 | continue; |
| 2468 | } |
| 2469 | |
| 2470 | if (!demoted && is_demoted(lkb)) { |
| 2471 | log_print("WARN: pending demoted %x node %d %s", |
| 2472 | lkb->lkb_id, lkb->lkb_nodeid, r->res_name); |
| 2473 | demote_restart = 1; |
| 2474 | continue; |
| 2475 | } |
| 2476 | |
| 2477 | if (deadlk) { |
| 2478 | /* |
| 2479 | * If DLM_LKB_NODLKWT flag is set and conversion |
| 2480 | * deadlock is detected, we request blocking AST and |
| 2481 | * down (or cancel) conversion. |
| 2482 | */ |
| 2483 | if (lkb->lkb_exflags & DLM_LKF_NODLCKWT) { |
| 2484 | if (lkb->lkb_highbast < lkb->lkb_rqmode) { |
| 2485 | queue_bast(r, lkb, lkb->lkb_rqmode); |
| 2486 | lkb->lkb_highbast = lkb->lkb_rqmode; |
| 2487 | } |
| 2488 | } else { |
| 2489 | log_print("WARN: pending deadlock %x node %d %s", |
| 2490 | lkb->lkb_id, lkb->lkb_nodeid, |
| 2491 | r->res_name); |
| 2492 | dlm_dump_rsb(r); |
| 2493 | } |
| 2494 | continue; |
| 2495 | } |
| 2496 | |
| 2497 | hi = max_t(int, lkb->lkb_rqmode, hi); |
| 2498 | |
| 2499 | if (cw && lkb->lkb_rqmode == DLM_LOCK_CW) |
| 2500 | *cw = 1; |
| 2501 | } |
| 2502 | |
| 2503 | if (grant_restart) |
| 2504 | goto restart; |
| 2505 | if (demote_restart && !quit) { |
| 2506 | quit = 1; |
| 2507 | goto restart; |
| 2508 | } |
| 2509 | |
| 2510 | return max_t(int, high, hi); |
| 2511 | } |
| 2512 | |
| 2513 | static int grant_pending_wait(struct dlm_rsb *r, int high, int *cw, |
| 2514 | unsigned int *count) |
| 2515 | { |
| 2516 | struct dlm_lkb *lkb, *s; |
| 2517 | |
| 2518 | list_for_each_entry_safe(lkb, s, &r->res_waitqueue, lkb_statequeue) { |
| 2519 | if (can_be_granted(r, lkb, 0, 0, NULL)) { |
| 2520 | grant_lock_pending(r, lkb); |
| 2521 | if (count) |
| 2522 | (*count)++; |
| 2523 | } else { |
| 2524 | high = max_t(int, lkb->lkb_rqmode, high); |
| 2525 | if (lkb->lkb_rqmode == DLM_LOCK_CW) |
| 2526 | *cw = 1; |
| 2527 | } |
| 2528 | } |
| 2529 | |
| 2530 | return high; |
| 2531 | } |
| 2532 | |
| 2533 | /* cw of 1 means there's a lock with a rqmode of DLM_LOCK_CW that's blocked |
| 2534 | on either the convert or waiting queue. |
| 2535 | high is the largest rqmode of all locks blocked on the convert or |
| 2536 | waiting queue. */ |
| 2537 | |
| 2538 | static int lock_requires_bast(struct dlm_lkb *gr, int high, int cw) |
| 2539 | { |
| 2540 | if (gr->lkb_grmode == DLM_LOCK_PR && cw) { |
| 2541 | if (gr->lkb_highbast < DLM_LOCK_EX) |
| 2542 | return 1; |
| 2543 | return 0; |
| 2544 | } |
| 2545 | |
| 2546 | if (gr->lkb_highbast < high && |
| 2547 | !__dlm_compat_matrix[gr->lkb_grmode+1][high+1]) |
| 2548 | return 1; |
| 2549 | return 0; |
| 2550 | } |
| 2551 | |
| 2552 | static void grant_pending_locks(struct dlm_rsb *r, unsigned int *count) |
| 2553 | { |
| 2554 | struct dlm_lkb *lkb, *s; |
| 2555 | int high = DLM_LOCK_IV; |
| 2556 | int cw = 0; |
| 2557 | |
| 2558 | if (!is_master(r)) { |
| 2559 | log_print("grant_pending_locks r nodeid %d", r->res_nodeid); |
| 2560 | dlm_dump_rsb(r); |
| 2561 | return; |
| 2562 | } |
| 2563 | |
| 2564 | high = grant_pending_convert(r, high, &cw, count); |
| 2565 | high = grant_pending_wait(r, high, &cw, count); |
| 2566 | |
| 2567 | if (high == DLM_LOCK_IV) |
| 2568 | return; |
| 2569 | |
| 2570 | /* |
| 2571 | * If there are locks left on the wait/convert queue then send blocking |
| 2572 | * ASTs to granted locks based on the largest requested mode (high) |
| 2573 | * found above. |
| 2574 | */ |
| 2575 | |
| 2576 | list_for_each_entry_safe(lkb, s, &r->res_grantqueue, lkb_statequeue) { |
| 2577 | if (lkb->lkb_bastfn && lock_requires_bast(lkb, high, cw)) { |
| 2578 | if (cw && high == DLM_LOCK_PR && |
| 2579 | lkb->lkb_grmode == DLM_LOCK_PR) |
| 2580 | queue_bast(r, lkb, DLM_LOCK_CW); |
| 2581 | else |
| 2582 | queue_bast(r, lkb, high); |
| 2583 | lkb->lkb_highbast = high; |
| 2584 | } |
| 2585 | } |
| 2586 | } |
| 2587 | |
| 2588 | static int modes_require_bast(struct dlm_lkb *gr, struct dlm_lkb *rq) |
| 2589 | { |
| 2590 | if ((gr->lkb_grmode == DLM_LOCK_PR && rq->lkb_rqmode == DLM_LOCK_CW) || |
| 2591 | (gr->lkb_grmode == DLM_LOCK_CW && rq->lkb_rqmode == DLM_LOCK_PR)) { |
| 2592 | if (gr->lkb_highbast < DLM_LOCK_EX) |
| 2593 | return 1; |
| 2594 | return 0; |
| 2595 | } |
| 2596 | |
| 2597 | if (gr->lkb_highbast < rq->lkb_rqmode && !modes_compat(gr, rq)) |
| 2598 | return 1; |
| 2599 | return 0; |
| 2600 | } |
| 2601 | |
| 2602 | static void send_bast_queue(struct dlm_rsb *r, struct list_head *head, |
| 2603 | struct dlm_lkb *lkb) |
| 2604 | { |
| 2605 | struct dlm_lkb *gr; |
| 2606 | |
| 2607 | list_for_each_entry(gr, head, lkb_statequeue) { |
| 2608 | /* skip self when sending basts to convertqueue */ |
| 2609 | if (gr == lkb) |
| 2610 | continue; |
| 2611 | if (gr->lkb_bastfn && modes_require_bast(gr, lkb)) { |
| 2612 | queue_bast(r, gr, lkb->lkb_rqmode); |
| 2613 | gr->lkb_highbast = lkb->lkb_rqmode; |
| 2614 | } |
| 2615 | } |
| 2616 | } |
| 2617 | |
| 2618 | static void send_blocking_asts(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 2619 | { |
| 2620 | send_bast_queue(r, &r->res_grantqueue, lkb); |
| 2621 | } |
| 2622 | |
| 2623 | static void send_blocking_asts_all(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 2624 | { |
| 2625 | send_bast_queue(r, &r->res_grantqueue, lkb); |
| 2626 | send_bast_queue(r, &r->res_convertqueue, lkb); |
| 2627 | } |
| 2628 | |
| 2629 | /* set_master(r, lkb) -- set the master nodeid of a resource |
| 2630 | |
| 2631 | The purpose of this function is to set the nodeid field in the given |
| 2632 | lkb using the nodeid field in the given rsb. If the rsb's nodeid is |
| 2633 | known, it can just be copied to the lkb and the function will return |
| 2634 | 0. If the rsb's nodeid is _not_ known, it needs to be looked up |
| 2635 | before it can be copied to the lkb. |
| 2636 | |
| 2637 | When the rsb nodeid is being looked up remotely, the initial lkb |
| 2638 | causing the lookup is kept on the ls_waiters list waiting for the |
| 2639 | lookup reply. Other lkb's waiting for the same rsb lookup are kept |
| 2640 | on the rsb's res_lookup list until the master is verified. |
| 2641 | |
| 2642 | Return values: |
| 2643 | 0: nodeid is set in rsb/lkb and the caller should go ahead and use it |
| 2644 | 1: the rsb master is not available and the lkb has been placed on |
| 2645 | a wait queue |
| 2646 | */ |
| 2647 | |
| 2648 | static int set_master(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 2649 | { |
| 2650 | int our_nodeid = dlm_our_nodeid(); |
| 2651 | |
| 2652 | if (rsb_flag(r, RSB_MASTER_UNCERTAIN)) { |
| 2653 | rsb_clear_flag(r, RSB_MASTER_UNCERTAIN); |
| 2654 | r->res_first_lkid = lkb->lkb_id; |
| 2655 | lkb->lkb_nodeid = r->res_nodeid; |
| 2656 | return 0; |
| 2657 | } |
| 2658 | |
| 2659 | if (r->res_first_lkid && r->res_first_lkid != lkb->lkb_id) { |
| 2660 | list_add_tail(&lkb->lkb_rsb_lookup, &r->res_lookup); |
| 2661 | return 1; |
| 2662 | } |
| 2663 | |
| 2664 | if (r->res_master_nodeid == our_nodeid) { |
| 2665 | lkb->lkb_nodeid = 0; |
| 2666 | return 0; |
| 2667 | } |
| 2668 | |
| 2669 | if (r->res_master_nodeid) { |
| 2670 | lkb->lkb_nodeid = r->res_master_nodeid; |
| 2671 | return 0; |
| 2672 | } |
| 2673 | |
| 2674 | if (dlm_dir_nodeid(r) == our_nodeid) { |
| 2675 | /* This is a somewhat unusual case; find_rsb will usually |
| 2676 | have set res_master_nodeid when dir nodeid is local, but |
| 2677 | there are cases where we become the dir node after we've |
| 2678 | past find_rsb and go through _request_lock again. |
| 2679 | confirm_master() or process_lookup_list() needs to be |
| 2680 | called after this. */ |
| 2681 | log_debug(r->res_ls, "set_master %x self master %d dir %d %s", |
| 2682 | lkb->lkb_id, r->res_master_nodeid, r->res_dir_nodeid, |
| 2683 | r->res_name); |
| 2684 | r->res_master_nodeid = our_nodeid; |
| 2685 | r->res_nodeid = 0; |
| 2686 | lkb->lkb_nodeid = 0; |
| 2687 | return 0; |
| 2688 | } |
| 2689 | |
| 2690 | r->res_first_lkid = lkb->lkb_id; |
| 2691 | send_lookup(r, lkb); |
| 2692 | return 1; |
| 2693 | } |
| 2694 | |
| 2695 | static void process_lookup_list(struct dlm_rsb *r) |
| 2696 | { |
| 2697 | struct dlm_lkb *lkb, *safe; |
| 2698 | |
| 2699 | list_for_each_entry_safe(lkb, safe, &r->res_lookup, lkb_rsb_lookup) { |
| 2700 | list_del_init(&lkb->lkb_rsb_lookup); |
| 2701 | _request_lock(r, lkb); |
| 2702 | } |
| 2703 | } |
| 2704 | |
| 2705 | /* confirm_master -- confirm (or deny) an rsb's master nodeid */ |
| 2706 | |
| 2707 | static void confirm_master(struct dlm_rsb *r, int error) |
| 2708 | { |
| 2709 | struct dlm_lkb *lkb; |
| 2710 | |
| 2711 | if (!r->res_first_lkid) |
| 2712 | return; |
| 2713 | |
| 2714 | switch (error) { |
| 2715 | case 0: |
| 2716 | case -EINPROGRESS: |
| 2717 | r->res_first_lkid = 0; |
| 2718 | process_lookup_list(r); |
| 2719 | break; |
| 2720 | |
| 2721 | case -EAGAIN: |
| 2722 | case -EBADR: |
| 2723 | case -ENOTBLK: |
| 2724 | /* the remote request failed and won't be retried (it was |
| 2725 | a NOQUEUE, or has been canceled/unlocked); make a waiting |
| 2726 | lkb the first_lkid */ |
| 2727 | |
| 2728 | r->res_first_lkid = 0; |
| 2729 | |
| 2730 | if (!list_empty(&r->res_lookup)) { |
| 2731 | lkb = list_entry(r->res_lookup.next, struct dlm_lkb, |
| 2732 | lkb_rsb_lookup); |
| 2733 | list_del_init(&lkb->lkb_rsb_lookup); |
| 2734 | r->res_first_lkid = lkb->lkb_id; |
| 2735 | _request_lock(r, lkb); |
| 2736 | } |
| 2737 | break; |
| 2738 | |
| 2739 | default: |
| 2740 | log_error(r->res_ls, "confirm_master unknown error %d", error); |
| 2741 | } |
| 2742 | } |
| 2743 | |
| 2744 | static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags, |
| 2745 | int namelen, void (*ast)(void *astparam), |
| 2746 | void *astparam, |
| 2747 | void (*bast)(void *astparam, int mode), |
| 2748 | struct dlm_args *args) |
| 2749 | { |
| 2750 | int rv = -EINVAL; |
| 2751 | |
| 2752 | /* check for invalid arg usage */ |
| 2753 | |
| 2754 | if (mode < 0 || mode > DLM_LOCK_EX) |
| 2755 | goto out; |
| 2756 | |
| 2757 | if (!(flags & DLM_LKF_CONVERT) && (namelen > DLM_RESNAME_MAXLEN)) |
| 2758 | goto out; |
| 2759 | |
| 2760 | if (flags & DLM_LKF_CANCEL) |
| 2761 | goto out; |
| 2762 | |
| 2763 | if (flags & DLM_LKF_QUECVT && !(flags & DLM_LKF_CONVERT)) |
| 2764 | goto out; |
| 2765 | |
| 2766 | if (flags & DLM_LKF_CONVDEADLK && !(flags & DLM_LKF_CONVERT)) |
| 2767 | goto out; |
| 2768 | |
| 2769 | if (flags & DLM_LKF_CONVDEADLK && flags & DLM_LKF_NOQUEUE) |
| 2770 | goto out; |
| 2771 | |
| 2772 | if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_CONVERT) |
| 2773 | goto out; |
| 2774 | |
| 2775 | if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_QUECVT) |
| 2776 | goto out; |
| 2777 | |
| 2778 | if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_NOQUEUE) |
| 2779 | goto out; |
| 2780 | |
| 2781 | if (flags & DLM_LKF_EXPEDITE && mode != DLM_LOCK_NL) |
| 2782 | goto out; |
| 2783 | |
| 2784 | if (!ast || !lksb) |
| 2785 | goto out; |
| 2786 | |
| 2787 | if (flags & DLM_LKF_VALBLK && !lksb->sb_lvbptr) |
| 2788 | goto out; |
| 2789 | |
| 2790 | if (flags & DLM_LKF_CONVERT && !lksb->sb_lkid) |
| 2791 | goto out; |
| 2792 | |
| 2793 | /* these args will be copied to the lkb in validate_lock_args, |
| 2794 | it cannot be done now because when converting locks, fields in |
| 2795 | an active lkb cannot be modified before locking the rsb */ |
| 2796 | |
| 2797 | args->flags = flags; |
| 2798 | args->astfn = ast; |
| 2799 | args->astparam = astparam; |
| 2800 | args->bastfn = bast; |
| 2801 | args->mode = mode; |
| 2802 | args->lksb = lksb; |
| 2803 | rv = 0; |
| 2804 | out: |
| 2805 | return rv; |
| 2806 | } |
| 2807 | |
| 2808 | static int set_unlock_args(uint32_t flags, void *astarg, struct dlm_args *args) |
| 2809 | { |
| 2810 | if (flags & ~(DLM_LKF_CANCEL | DLM_LKF_VALBLK | DLM_LKF_IVVALBLK | |
| 2811 | DLM_LKF_FORCEUNLOCK)) |
| 2812 | return -EINVAL; |
| 2813 | |
| 2814 | if (flags & DLM_LKF_CANCEL && flags & DLM_LKF_FORCEUNLOCK) |
| 2815 | return -EINVAL; |
| 2816 | |
| 2817 | args->flags = flags; |
| 2818 | args->astparam = astarg; |
| 2819 | return 0; |
| 2820 | } |
| 2821 | |
| 2822 | static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb, |
| 2823 | struct dlm_args *args) |
| 2824 | { |
| 2825 | int rv = -EBUSY; |
| 2826 | |
| 2827 | if (args->flags & DLM_LKF_CONVERT) { |
| 2828 | if (lkb->lkb_status != DLM_LKSTS_GRANTED) |
| 2829 | goto out; |
| 2830 | |
| 2831 | /* lock not allowed if there's any op in progress */ |
| 2832 | if (lkb->lkb_wait_type || lkb->lkb_wait_count) |
| 2833 | goto out; |
| 2834 | |
| 2835 | if (is_overlap(lkb)) |
| 2836 | goto out; |
| 2837 | |
| 2838 | rv = -EINVAL; |
| 2839 | if (test_bit(DLM_IFL_MSTCPY_BIT, &lkb->lkb_iflags)) |
| 2840 | goto out; |
| 2841 | |
| 2842 | if (args->flags & DLM_LKF_QUECVT && |
| 2843 | !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1]) |
| 2844 | goto out; |
| 2845 | } |
| 2846 | |
| 2847 | lkb->lkb_exflags = args->flags; |
| 2848 | dlm_set_sbflags_val(lkb, 0); |
| 2849 | lkb->lkb_astfn = args->astfn; |
| 2850 | lkb->lkb_astparam = args->astparam; |
| 2851 | lkb->lkb_bastfn = args->bastfn; |
| 2852 | lkb->lkb_rqmode = args->mode; |
| 2853 | lkb->lkb_lksb = args->lksb; |
| 2854 | lkb->lkb_lvbptr = args->lksb->sb_lvbptr; |
| 2855 | lkb->lkb_ownpid = (int) current->pid; |
| 2856 | rv = 0; |
| 2857 | out: |
| 2858 | switch (rv) { |
| 2859 | case 0: |
| 2860 | break; |
| 2861 | case -EINVAL: |
| 2862 | /* annoy the user because dlm usage is wrong */ |
| 2863 | WARN_ON(1); |
| 2864 | log_error(ls, "%s %d %x %x %x %d %d %s", __func__, |
| 2865 | rv, lkb->lkb_id, dlm_iflags_val(lkb), args->flags, |
| 2866 | lkb->lkb_status, lkb->lkb_wait_type, |
| 2867 | lkb->lkb_resource->res_name); |
| 2868 | break; |
| 2869 | default: |
| 2870 | log_debug(ls, "%s %d %x %x %x %d %d %s", __func__, |
| 2871 | rv, lkb->lkb_id, dlm_iflags_val(lkb), args->flags, |
| 2872 | lkb->lkb_status, lkb->lkb_wait_type, |
| 2873 | lkb->lkb_resource->res_name); |
| 2874 | break; |
| 2875 | } |
| 2876 | |
| 2877 | return rv; |
| 2878 | } |
| 2879 | |
| 2880 | /* when dlm_unlock() sees -EBUSY with CANCEL/FORCEUNLOCK it returns 0 |
| 2881 | for success */ |
| 2882 | |
| 2883 | /* note: it's valid for lkb_nodeid/res_nodeid to be -1 when we get here |
| 2884 | because there may be a lookup in progress and it's valid to do |
| 2885 | cancel/unlockf on it */ |
| 2886 | |
| 2887 | static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args) |
| 2888 | { |
| 2889 | struct dlm_ls *ls = lkb->lkb_resource->res_ls; |
| 2890 | int rv = -EBUSY; |
| 2891 | |
| 2892 | /* normal unlock not allowed if there's any op in progress */ |
| 2893 | if (!(args->flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)) && |
| 2894 | (lkb->lkb_wait_type || lkb->lkb_wait_count)) |
| 2895 | goto out; |
| 2896 | |
| 2897 | /* an lkb may be waiting for an rsb lookup to complete where the |
| 2898 | lookup was initiated by another lock */ |
| 2899 | |
| 2900 | if (!list_empty(&lkb->lkb_rsb_lookup)) { |
| 2901 | if (args->flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)) { |
| 2902 | log_debug(ls, "unlock on rsb_lookup %x", lkb->lkb_id); |
| 2903 | list_del_init(&lkb->lkb_rsb_lookup); |
| 2904 | queue_cast(lkb->lkb_resource, lkb, |
| 2905 | args->flags & DLM_LKF_CANCEL ? |
| 2906 | -DLM_ECANCEL : -DLM_EUNLOCK); |
| 2907 | unhold_lkb(lkb); /* undoes create_lkb() */ |
| 2908 | } |
| 2909 | /* caller changes -EBUSY to 0 for CANCEL and FORCEUNLOCK */ |
| 2910 | goto out; |
| 2911 | } |
| 2912 | |
| 2913 | rv = -EINVAL; |
| 2914 | if (test_bit(DLM_IFL_MSTCPY_BIT, &lkb->lkb_iflags)) { |
| 2915 | log_error(ls, "unlock on MSTCPY %x", lkb->lkb_id); |
| 2916 | dlm_print_lkb(lkb); |
| 2917 | goto out; |
| 2918 | } |
| 2919 | |
| 2920 | /* an lkb may still exist even though the lock is EOL'ed due to a |
| 2921 | * cancel, unlock or failed noqueue request; an app can't use these |
| 2922 | * locks; return same error as if the lkid had not been found at all |
| 2923 | */ |
| 2924 | |
| 2925 | if (test_bit(DLM_IFL_ENDOFLIFE_BIT, &lkb->lkb_iflags)) { |
| 2926 | log_debug(ls, "unlock on ENDOFLIFE %x", lkb->lkb_id); |
| 2927 | rv = -ENOENT; |
| 2928 | goto out; |
| 2929 | } |
| 2930 | |
| 2931 | /* cancel not allowed with another cancel/unlock in progress */ |
| 2932 | |
| 2933 | if (args->flags & DLM_LKF_CANCEL) { |
| 2934 | if (lkb->lkb_exflags & DLM_LKF_CANCEL) |
| 2935 | goto out; |
| 2936 | |
| 2937 | if (is_overlap(lkb)) |
| 2938 | goto out; |
| 2939 | |
| 2940 | if (test_bit(DLM_IFL_RESEND_BIT, &lkb->lkb_iflags)) { |
| 2941 | set_bit(DLM_IFL_OVERLAP_CANCEL_BIT, &lkb->lkb_iflags); |
| 2942 | rv = -EBUSY; |
| 2943 | goto out; |
| 2944 | } |
| 2945 | |
| 2946 | /* there's nothing to cancel */ |
| 2947 | if (lkb->lkb_status == DLM_LKSTS_GRANTED && |
| 2948 | !lkb->lkb_wait_type) { |
| 2949 | rv = -EBUSY; |
| 2950 | goto out; |
| 2951 | } |
| 2952 | |
| 2953 | switch (lkb->lkb_wait_type) { |
| 2954 | case DLM_MSG_LOOKUP: |
| 2955 | case DLM_MSG_REQUEST: |
| 2956 | set_bit(DLM_IFL_OVERLAP_CANCEL_BIT, &lkb->lkb_iflags); |
| 2957 | rv = -EBUSY; |
| 2958 | goto out; |
| 2959 | case DLM_MSG_UNLOCK: |
| 2960 | case DLM_MSG_CANCEL: |
| 2961 | goto out; |
| 2962 | } |
| 2963 | /* add_to_waiters() will set OVERLAP_CANCEL */ |
| 2964 | goto out_ok; |
| 2965 | } |
| 2966 | |
| 2967 | /* do we need to allow a force-unlock if there's a normal unlock |
| 2968 | already in progress? in what conditions could the normal unlock |
| 2969 | fail such that we'd want to send a force-unlock to be sure? */ |
| 2970 | |
| 2971 | if (args->flags & DLM_LKF_FORCEUNLOCK) { |
| 2972 | if (lkb->lkb_exflags & DLM_LKF_FORCEUNLOCK) |
| 2973 | goto out; |
| 2974 | |
| 2975 | if (is_overlap_unlock(lkb)) |
| 2976 | goto out; |
| 2977 | |
| 2978 | if (test_bit(DLM_IFL_RESEND_BIT, &lkb->lkb_iflags)) { |
| 2979 | set_bit(DLM_IFL_OVERLAP_UNLOCK_BIT, &lkb->lkb_iflags); |
| 2980 | rv = -EBUSY; |
| 2981 | goto out; |
| 2982 | } |
| 2983 | |
| 2984 | switch (lkb->lkb_wait_type) { |
| 2985 | case DLM_MSG_LOOKUP: |
| 2986 | case DLM_MSG_REQUEST: |
| 2987 | set_bit(DLM_IFL_OVERLAP_UNLOCK_BIT, &lkb->lkb_iflags); |
| 2988 | rv = -EBUSY; |
| 2989 | goto out; |
| 2990 | case DLM_MSG_UNLOCK: |
| 2991 | goto out; |
| 2992 | } |
| 2993 | /* add_to_waiters() will set OVERLAP_UNLOCK */ |
| 2994 | } |
| 2995 | |
| 2996 | out_ok: |
| 2997 | /* an overlapping op shouldn't blow away exflags from other op */ |
| 2998 | lkb->lkb_exflags |= args->flags; |
| 2999 | dlm_set_sbflags_val(lkb, 0); |
| 3000 | lkb->lkb_astparam = args->astparam; |
| 3001 | rv = 0; |
| 3002 | out: |
| 3003 | switch (rv) { |
| 3004 | case 0: |
| 3005 | break; |
| 3006 | case -EINVAL: |
| 3007 | /* annoy the user because dlm usage is wrong */ |
| 3008 | WARN_ON(1); |
| 3009 | log_error(ls, "%s %d %x %x %x %x %d %s", __func__, rv, |
| 3010 | lkb->lkb_id, dlm_iflags_val(lkb), lkb->lkb_exflags, |
| 3011 | args->flags, lkb->lkb_wait_type, |
| 3012 | lkb->lkb_resource->res_name); |
| 3013 | break; |
| 3014 | default: |
| 3015 | log_debug(ls, "%s %d %x %x %x %x %d %s", __func__, rv, |
| 3016 | lkb->lkb_id, dlm_iflags_val(lkb), lkb->lkb_exflags, |
| 3017 | args->flags, lkb->lkb_wait_type, |
| 3018 | lkb->lkb_resource->res_name); |
| 3019 | break; |
| 3020 | } |
| 3021 | |
| 3022 | return rv; |
| 3023 | } |
| 3024 | |
| 3025 | /* |
| 3026 | * Four stage 4 varieties: |
| 3027 | * do_request(), do_convert(), do_unlock(), do_cancel() |
| 3028 | * These are called on the master node for the given lock and |
| 3029 | * from the central locking logic. |
| 3030 | */ |
| 3031 | |
| 3032 | static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3033 | { |
| 3034 | int error = 0; |
| 3035 | |
| 3036 | if (can_be_granted(r, lkb, 1, 0, NULL)) { |
| 3037 | grant_lock(r, lkb); |
| 3038 | queue_cast(r, lkb, 0); |
| 3039 | goto out; |
| 3040 | } |
| 3041 | |
| 3042 | if (can_be_queued(lkb)) { |
| 3043 | error = -EINPROGRESS; |
| 3044 | add_lkb(r, lkb, DLM_LKSTS_WAITING); |
| 3045 | goto out; |
| 3046 | } |
| 3047 | |
| 3048 | error = -EAGAIN; |
| 3049 | queue_cast(r, lkb, -EAGAIN); |
| 3050 | out: |
| 3051 | return error; |
| 3052 | } |
| 3053 | |
| 3054 | static void do_request_effects(struct dlm_rsb *r, struct dlm_lkb *lkb, |
| 3055 | int error) |
| 3056 | { |
| 3057 | switch (error) { |
| 3058 | case -EAGAIN: |
| 3059 | if (force_blocking_asts(lkb)) |
| 3060 | send_blocking_asts_all(r, lkb); |
| 3061 | break; |
| 3062 | case -EINPROGRESS: |
| 3063 | send_blocking_asts(r, lkb); |
| 3064 | break; |
| 3065 | } |
| 3066 | } |
| 3067 | |
| 3068 | static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3069 | { |
| 3070 | int error = 0; |
| 3071 | int deadlk = 0; |
| 3072 | |
| 3073 | /* changing an existing lock may allow others to be granted */ |
| 3074 | |
| 3075 | if (can_be_granted(r, lkb, 1, 0, &deadlk)) { |
| 3076 | grant_lock(r, lkb); |
| 3077 | queue_cast(r, lkb, 0); |
| 3078 | goto out; |
| 3079 | } |
| 3080 | |
| 3081 | /* can_be_granted() detected that this lock would block in a conversion |
| 3082 | deadlock, so we leave it on the granted queue and return EDEADLK in |
| 3083 | the ast for the convert. */ |
| 3084 | |
| 3085 | if (deadlk && !(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) { |
| 3086 | /* it's left on the granted queue */ |
| 3087 | revert_lock(r, lkb); |
| 3088 | queue_cast(r, lkb, -EDEADLK); |
| 3089 | error = -EDEADLK; |
| 3090 | goto out; |
| 3091 | } |
| 3092 | |
| 3093 | /* is_demoted() means the can_be_granted() above set the grmode |
| 3094 | to NL, and left us on the granted queue. This auto-demotion |
| 3095 | (due to CONVDEADLK) might mean other locks, and/or this lock, are |
| 3096 | now grantable. We have to try to grant other converting locks |
| 3097 | before we try again to grant this one. */ |
| 3098 | |
| 3099 | if (is_demoted(lkb)) { |
| 3100 | grant_pending_convert(r, DLM_LOCK_IV, NULL, NULL); |
| 3101 | if (_can_be_granted(r, lkb, 1, 0)) { |
| 3102 | grant_lock(r, lkb); |
| 3103 | queue_cast(r, lkb, 0); |
| 3104 | goto out; |
| 3105 | } |
| 3106 | /* else fall through and move to convert queue */ |
| 3107 | } |
| 3108 | |
| 3109 | if (can_be_queued(lkb)) { |
| 3110 | error = -EINPROGRESS; |
| 3111 | del_lkb(r, lkb); |
| 3112 | add_lkb(r, lkb, DLM_LKSTS_CONVERT); |
| 3113 | goto out; |
| 3114 | } |
| 3115 | |
| 3116 | error = -EAGAIN; |
| 3117 | queue_cast(r, lkb, -EAGAIN); |
| 3118 | out: |
| 3119 | return error; |
| 3120 | } |
| 3121 | |
| 3122 | static void do_convert_effects(struct dlm_rsb *r, struct dlm_lkb *lkb, |
| 3123 | int error) |
| 3124 | { |
| 3125 | switch (error) { |
| 3126 | case 0: |
| 3127 | grant_pending_locks(r, NULL); |
| 3128 | /* grant_pending_locks also sends basts */ |
| 3129 | break; |
| 3130 | case -EAGAIN: |
| 3131 | if (force_blocking_asts(lkb)) |
| 3132 | send_blocking_asts_all(r, lkb); |
| 3133 | break; |
| 3134 | case -EINPROGRESS: |
| 3135 | send_blocking_asts(r, lkb); |
| 3136 | break; |
| 3137 | } |
| 3138 | } |
| 3139 | |
| 3140 | static int do_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3141 | { |
| 3142 | remove_lock(r, lkb); |
| 3143 | queue_cast(r, lkb, -DLM_EUNLOCK); |
| 3144 | return -DLM_EUNLOCK; |
| 3145 | } |
| 3146 | |
| 3147 | static void do_unlock_effects(struct dlm_rsb *r, struct dlm_lkb *lkb, |
| 3148 | int error) |
| 3149 | { |
| 3150 | grant_pending_locks(r, NULL); |
| 3151 | } |
| 3152 | |
| 3153 | /* returns: 0 did nothing, -DLM_ECANCEL canceled lock */ |
| 3154 | |
| 3155 | static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3156 | { |
| 3157 | int error; |
| 3158 | |
| 3159 | error = revert_lock(r, lkb); |
| 3160 | if (error) { |
| 3161 | queue_cast(r, lkb, -DLM_ECANCEL); |
| 3162 | return -DLM_ECANCEL; |
| 3163 | } |
| 3164 | return 0; |
| 3165 | } |
| 3166 | |
| 3167 | static void do_cancel_effects(struct dlm_rsb *r, struct dlm_lkb *lkb, |
| 3168 | int error) |
| 3169 | { |
| 3170 | if (error) |
| 3171 | grant_pending_locks(r, NULL); |
| 3172 | } |
| 3173 | |
| 3174 | /* |
| 3175 | * Four stage 3 varieties: |
| 3176 | * _request_lock(), _convert_lock(), _unlock_lock(), _cancel_lock() |
| 3177 | */ |
| 3178 | |
| 3179 | /* add a new lkb to a possibly new rsb, called by requesting process */ |
| 3180 | |
| 3181 | static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3182 | { |
| 3183 | int error; |
| 3184 | |
| 3185 | /* set_master: sets lkb nodeid from r */ |
| 3186 | |
| 3187 | error = set_master(r, lkb); |
| 3188 | if (error < 0) |
| 3189 | goto out; |
| 3190 | if (error) { |
| 3191 | error = 0; |
| 3192 | goto out; |
| 3193 | } |
| 3194 | |
| 3195 | if (is_remote(r)) { |
| 3196 | /* receive_request() calls do_request() on remote node */ |
| 3197 | error = send_request(r, lkb); |
| 3198 | } else { |
| 3199 | error = do_request(r, lkb); |
| 3200 | /* for remote locks the request_reply is sent |
| 3201 | between do_request and do_request_effects */ |
| 3202 | do_request_effects(r, lkb, error); |
| 3203 | } |
| 3204 | out: |
| 3205 | return error; |
| 3206 | } |
| 3207 | |
| 3208 | /* change some property of an existing lkb, e.g. mode */ |
| 3209 | |
| 3210 | static int _convert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3211 | { |
| 3212 | int error; |
| 3213 | |
| 3214 | if (is_remote(r)) { |
| 3215 | /* receive_convert() calls do_convert() on remote node */ |
| 3216 | error = send_convert(r, lkb); |
| 3217 | } else { |
| 3218 | error = do_convert(r, lkb); |
| 3219 | /* for remote locks the convert_reply is sent |
| 3220 | between do_convert and do_convert_effects */ |
| 3221 | do_convert_effects(r, lkb, error); |
| 3222 | } |
| 3223 | |
| 3224 | return error; |
| 3225 | } |
| 3226 | |
| 3227 | /* remove an existing lkb from the granted queue */ |
| 3228 | |
| 3229 | static int _unlock_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3230 | { |
| 3231 | int error; |
| 3232 | |
| 3233 | if (is_remote(r)) { |
| 3234 | /* receive_unlock() calls do_unlock() on remote node */ |
| 3235 | error = send_unlock(r, lkb); |
| 3236 | } else { |
| 3237 | error = do_unlock(r, lkb); |
| 3238 | /* for remote locks the unlock_reply is sent |
| 3239 | between do_unlock and do_unlock_effects */ |
| 3240 | do_unlock_effects(r, lkb, error); |
| 3241 | } |
| 3242 | |
| 3243 | return error; |
| 3244 | } |
| 3245 | |
| 3246 | /* remove an existing lkb from the convert or wait queue */ |
| 3247 | |
| 3248 | static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3249 | { |
| 3250 | int error; |
| 3251 | |
| 3252 | if (is_remote(r)) { |
| 3253 | /* receive_cancel() calls do_cancel() on remote node */ |
| 3254 | error = send_cancel(r, lkb); |
| 3255 | } else { |
| 3256 | error = do_cancel(r, lkb); |
| 3257 | /* for remote locks the cancel_reply is sent |
| 3258 | between do_cancel and do_cancel_effects */ |
| 3259 | do_cancel_effects(r, lkb, error); |
| 3260 | } |
| 3261 | |
| 3262 | return error; |
| 3263 | } |
| 3264 | |
| 3265 | /* |
| 3266 | * Four stage 2 varieties: |
| 3267 | * request_lock(), convert_lock(), unlock_lock(), cancel_lock() |
| 3268 | */ |
| 3269 | |
| 3270 | static int request_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, |
| 3271 | const void *name, int len, |
| 3272 | struct dlm_args *args) |
| 3273 | { |
| 3274 | struct dlm_rsb *r; |
| 3275 | int error; |
| 3276 | |
| 3277 | error = validate_lock_args(ls, lkb, args); |
| 3278 | if (error) |
| 3279 | return error; |
| 3280 | |
| 3281 | error = find_rsb(ls, name, len, 0, R_REQUEST, &r); |
| 3282 | if (error) |
| 3283 | return error; |
| 3284 | |
| 3285 | lock_rsb(r); |
| 3286 | |
| 3287 | attach_lkb(r, lkb); |
| 3288 | lkb->lkb_lksb->sb_lkid = lkb->lkb_id; |
| 3289 | |
| 3290 | error = _request_lock(r, lkb); |
| 3291 | |
| 3292 | unlock_rsb(r); |
| 3293 | put_rsb(r); |
| 3294 | return error; |
| 3295 | } |
| 3296 | |
| 3297 | static int convert_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, |
| 3298 | struct dlm_args *args) |
| 3299 | { |
| 3300 | struct dlm_rsb *r; |
| 3301 | int error; |
| 3302 | |
| 3303 | r = lkb->lkb_resource; |
| 3304 | |
| 3305 | hold_rsb(r); |
| 3306 | lock_rsb(r); |
| 3307 | |
| 3308 | error = validate_lock_args(ls, lkb, args); |
| 3309 | if (error) |
| 3310 | goto out; |
| 3311 | |
| 3312 | error = _convert_lock(r, lkb); |
| 3313 | out: |
| 3314 | unlock_rsb(r); |
| 3315 | put_rsb(r); |
| 3316 | return error; |
| 3317 | } |
| 3318 | |
| 3319 | static int unlock_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, |
| 3320 | struct dlm_args *args) |
| 3321 | { |
| 3322 | struct dlm_rsb *r; |
| 3323 | int error; |
| 3324 | |
| 3325 | r = lkb->lkb_resource; |
| 3326 | |
| 3327 | hold_rsb(r); |
| 3328 | lock_rsb(r); |
| 3329 | |
| 3330 | error = validate_unlock_args(lkb, args); |
| 3331 | if (error) |
| 3332 | goto out; |
| 3333 | |
| 3334 | error = _unlock_lock(r, lkb); |
| 3335 | out: |
| 3336 | unlock_rsb(r); |
| 3337 | put_rsb(r); |
| 3338 | return error; |
| 3339 | } |
| 3340 | |
| 3341 | static int cancel_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, |
| 3342 | struct dlm_args *args) |
| 3343 | { |
| 3344 | struct dlm_rsb *r; |
| 3345 | int error; |
| 3346 | |
| 3347 | r = lkb->lkb_resource; |
| 3348 | |
| 3349 | hold_rsb(r); |
| 3350 | lock_rsb(r); |
| 3351 | |
| 3352 | error = validate_unlock_args(lkb, args); |
| 3353 | if (error) |
| 3354 | goto out; |
| 3355 | |
| 3356 | error = _cancel_lock(r, lkb); |
| 3357 | out: |
| 3358 | unlock_rsb(r); |
| 3359 | put_rsb(r); |
| 3360 | return error; |
| 3361 | } |
| 3362 | |
| 3363 | /* |
| 3364 | * Two stage 1 varieties: dlm_lock() and dlm_unlock() |
| 3365 | */ |
| 3366 | |
| 3367 | int dlm_lock(dlm_lockspace_t *lockspace, |
| 3368 | int mode, |
| 3369 | struct dlm_lksb *lksb, |
| 3370 | uint32_t flags, |
| 3371 | const void *name, |
| 3372 | unsigned int namelen, |
| 3373 | uint32_t parent_lkid, |
| 3374 | void (*ast) (void *astarg), |
| 3375 | void *astarg, |
| 3376 | void (*bast) (void *astarg, int mode)) |
| 3377 | { |
| 3378 | struct dlm_ls *ls; |
| 3379 | struct dlm_lkb *lkb; |
| 3380 | struct dlm_args args; |
| 3381 | int error, convert = flags & DLM_LKF_CONVERT; |
| 3382 | |
| 3383 | ls = dlm_find_lockspace_local(lockspace); |
| 3384 | if (!ls) |
| 3385 | return -EINVAL; |
| 3386 | |
| 3387 | dlm_lock_recovery(ls); |
| 3388 | |
| 3389 | if (convert) |
| 3390 | error = find_lkb(ls, lksb->sb_lkid, &lkb); |
| 3391 | else |
| 3392 | error = create_lkb(ls, &lkb); |
| 3393 | |
| 3394 | if (error) |
| 3395 | goto out; |
| 3396 | |
| 3397 | trace_dlm_lock_start(ls, lkb, name, namelen, mode, flags); |
| 3398 | |
| 3399 | error = set_lock_args(mode, lksb, flags, namelen, ast, astarg, bast, |
| 3400 | &args); |
| 3401 | if (error) |
| 3402 | goto out_put; |
| 3403 | |
| 3404 | if (convert) |
| 3405 | error = convert_lock(ls, lkb, &args); |
| 3406 | else |
| 3407 | error = request_lock(ls, lkb, name, namelen, &args); |
| 3408 | |
| 3409 | if (error == -EINPROGRESS) |
| 3410 | error = 0; |
| 3411 | out_put: |
| 3412 | trace_dlm_lock_end(ls, lkb, name, namelen, mode, flags, error, true); |
| 3413 | |
| 3414 | if (convert || error) |
| 3415 | __put_lkb(ls, lkb); |
| 3416 | if (error == -EAGAIN || error == -EDEADLK) |
| 3417 | error = 0; |
| 3418 | out: |
| 3419 | dlm_unlock_recovery(ls); |
| 3420 | dlm_put_lockspace(ls); |
| 3421 | return error; |
| 3422 | } |
| 3423 | |
| 3424 | int dlm_unlock(dlm_lockspace_t *lockspace, |
| 3425 | uint32_t lkid, |
| 3426 | uint32_t flags, |
| 3427 | struct dlm_lksb *lksb, |
| 3428 | void *astarg) |
| 3429 | { |
| 3430 | struct dlm_ls *ls; |
| 3431 | struct dlm_lkb *lkb; |
| 3432 | struct dlm_args args; |
| 3433 | int error; |
| 3434 | |
| 3435 | ls = dlm_find_lockspace_local(lockspace); |
| 3436 | if (!ls) |
| 3437 | return -EINVAL; |
| 3438 | |
| 3439 | dlm_lock_recovery(ls); |
| 3440 | |
| 3441 | error = find_lkb(ls, lkid, &lkb); |
| 3442 | if (error) |
| 3443 | goto out; |
| 3444 | |
| 3445 | trace_dlm_unlock_start(ls, lkb, flags); |
| 3446 | |
| 3447 | error = set_unlock_args(flags, astarg, &args); |
| 3448 | if (error) |
| 3449 | goto out_put; |
| 3450 | |
| 3451 | if (flags & DLM_LKF_CANCEL) |
| 3452 | error = cancel_lock(ls, lkb, &args); |
| 3453 | else |
| 3454 | error = unlock_lock(ls, lkb, &args); |
| 3455 | |
| 3456 | if (error == -DLM_EUNLOCK || error == -DLM_ECANCEL) |
| 3457 | error = 0; |
| 3458 | if (error == -EBUSY && (flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK))) |
| 3459 | error = 0; |
| 3460 | out_put: |
| 3461 | trace_dlm_unlock_end(ls, lkb, flags, error); |
| 3462 | |
| 3463 | dlm_put_lkb(lkb); |
| 3464 | out: |
| 3465 | dlm_unlock_recovery(ls); |
| 3466 | dlm_put_lockspace(ls); |
| 3467 | return error; |
| 3468 | } |
| 3469 | |
| 3470 | /* |
| 3471 | * send/receive routines for remote operations and replies |
| 3472 | * |
| 3473 | * send_args |
| 3474 | * send_common |
| 3475 | * send_request receive_request |
| 3476 | * send_convert receive_convert |
| 3477 | * send_unlock receive_unlock |
| 3478 | * send_cancel receive_cancel |
| 3479 | * send_grant receive_grant |
| 3480 | * send_bast receive_bast |
| 3481 | * send_lookup receive_lookup |
| 3482 | * send_remove receive_remove |
| 3483 | * |
| 3484 | * send_common_reply |
| 3485 | * receive_request_reply send_request_reply |
| 3486 | * receive_convert_reply send_convert_reply |
| 3487 | * receive_unlock_reply send_unlock_reply |
| 3488 | * receive_cancel_reply send_cancel_reply |
| 3489 | * receive_lookup_reply send_lookup_reply |
| 3490 | */ |
| 3491 | |
| 3492 | static int _create_message(struct dlm_ls *ls, int mb_len, |
| 3493 | int to_nodeid, int mstype, |
| 3494 | struct dlm_message **ms_ret, |
| 3495 | struct dlm_mhandle **mh_ret) |
| 3496 | { |
| 3497 | struct dlm_message *ms; |
| 3498 | struct dlm_mhandle *mh; |
| 3499 | char *mb; |
| 3500 | |
| 3501 | /* get_buffer gives us a message handle (mh) that we need to |
| 3502 | pass into midcomms_commit and a message buffer (mb) that we |
| 3503 | write our data into */ |
| 3504 | |
| 3505 | mh = dlm_midcomms_get_mhandle(to_nodeid, mb_len, &mb); |
| 3506 | if (!mh) |
| 3507 | return -ENOBUFS; |
| 3508 | |
| 3509 | ms = (struct dlm_message *) mb; |
| 3510 | |
| 3511 | ms->m_header.h_version = cpu_to_le32(DLM_HEADER_MAJOR | DLM_HEADER_MINOR); |
| 3512 | ms->m_header.u.h_lockspace = cpu_to_le32(ls->ls_global_id); |
| 3513 | ms->m_header.h_nodeid = cpu_to_le32(dlm_our_nodeid()); |
| 3514 | ms->m_header.h_length = cpu_to_le16(mb_len); |
| 3515 | ms->m_header.h_cmd = DLM_MSG; |
| 3516 | |
| 3517 | ms->m_type = cpu_to_le32(mstype); |
| 3518 | |
| 3519 | *mh_ret = mh; |
| 3520 | *ms_ret = ms; |
| 3521 | return 0; |
| 3522 | } |
| 3523 | |
| 3524 | static int create_message(struct dlm_rsb *r, struct dlm_lkb *lkb, |
| 3525 | int to_nodeid, int mstype, |
| 3526 | struct dlm_message **ms_ret, |
| 3527 | struct dlm_mhandle **mh_ret) |
| 3528 | { |
| 3529 | int mb_len = sizeof(struct dlm_message); |
| 3530 | |
| 3531 | switch (mstype) { |
| 3532 | case DLM_MSG_REQUEST: |
| 3533 | case DLM_MSG_LOOKUP: |
| 3534 | case DLM_MSG_REMOVE: |
| 3535 | mb_len += r->res_length; |
| 3536 | break; |
| 3537 | case DLM_MSG_CONVERT: |
| 3538 | case DLM_MSG_UNLOCK: |
| 3539 | case DLM_MSG_REQUEST_REPLY: |
| 3540 | case DLM_MSG_CONVERT_REPLY: |
| 3541 | case DLM_MSG_GRANT: |
| 3542 | if (lkb && lkb->lkb_lvbptr && (lkb->lkb_exflags & DLM_LKF_VALBLK)) |
| 3543 | mb_len += r->res_ls->ls_lvblen; |
| 3544 | break; |
| 3545 | } |
| 3546 | |
| 3547 | return _create_message(r->res_ls, mb_len, to_nodeid, mstype, |
| 3548 | ms_ret, mh_ret); |
| 3549 | } |
| 3550 | |
| 3551 | /* further lowcomms enhancements or alternate implementations may make |
| 3552 | the return value from this function useful at some point */ |
| 3553 | |
| 3554 | static int send_message(struct dlm_mhandle *mh, struct dlm_message *ms, |
| 3555 | const void *name, int namelen) |
| 3556 | { |
| 3557 | dlm_midcomms_commit_mhandle(mh, name, namelen); |
| 3558 | return 0; |
| 3559 | } |
| 3560 | |
| 3561 | static void send_args(struct dlm_rsb *r, struct dlm_lkb *lkb, |
| 3562 | struct dlm_message *ms) |
| 3563 | { |
| 3564 | ms->m_nodeid = cpu_to_le32(lkb->lkb_nodeid); |
| 3565 | ms->m_pid = cpu_to_le32(lkb->lkb_ownpid); |
| 3566 | ms->m_lkid = cpu_to_le32(lkb->lkb_id); |
| 3567 | ms->m_remid = cpu_to_le32(lkb->lkb_remid); |
| 3568 | ms->m_exflags = cpu_to_le32(lkb->lkb_exflags); |
| 3569 | ms->m_sbflags = cpu_to_le32(dlm_sbflags_val(lkb)); |
| 3570 | ms->m_flags = cpu_to_le32(dlm_dflags_val(lkb)); |
| 3571 | ms->m_lvbseq = cpu_to_le32(lkb->lkb_lvbseq); |
| 3572 | ms->m_status = cpu_to_le32(lkb->lkb_status); |
| 3573 | ms->m_grmode = cpu_to_le32(lkb->lkb_grmode); |
| 3574 | ms->m_rqmode = cpu_to_le32(lkb->lkb_rqmode); |
| 3575 | ms->m_hash = cpu_to_le32(r->res_hash); |
| 3576 | |
| 3577 | /* m_result and m_bastmode are set from function args, |
| 3578 | not from lkb fields */ |
| 3579 | |
| 3580 | if (lkb->lkb_bastfn) |
| 3581 | ms->m_asts |= cpu_to_le32(DLM_CB_BAST); |
| 3582 | if (lkb->lkb_astfn) |
| 3583 | ms->m_asts |= cpu_to_le32(DLM_CB_CAST); |
| 3584 | |
| 3585 | /* compare with switch in create_message; send_remove() doesn't |
| 3586 | use send_args() */ |
| 3587 | |
| 3588 | switch (ms->m_type) { |
| 3589 | case cpu_to_le32(DLM_MSG_REQUEST): |
| 3590 | case cpu_to_le32(DLM_MSG_LOOKUP): |
| 3591 | memcpy(ms->m_extra, r->res_name, r->res_length); |
| 3592 | break; |
| 3593 | case cpu_to_le32(DLM_MSG_CONVERT): |
| 3594 | case cpu_to_le32(DLM_MSG_UNLOCK): |
| 3595 | case cpu_to_le32(DLM_MSG_REQUEST_REPLY): |
| 3596 | case cpu_to_le32(DLM_MSG_CONVERT_REPLY): |
| 3597 | case cpu_to_le32(DLM_MSG_GRANT): |
| 3598 | if (!lkb->lkb_lvbptr || !(lkb->lkb_exflags & DLM_LKF_VALBLK)) |
| 3599 | break; |
| 3600 | memcpy(ms->m_extra, lkb->lkb_lvbptr, r->res_ls->ls_lvblen); |
| 3601 | break; |
| 3602 | } |
| 3603 | } |
| 3604 | |
| 3605 | static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype) |
| 3606 | { |
| 3607 | struct dlm_message *ms; |
| 3608 | struct dlm_mhandle *mh; |
| 3609 | int to_nodeid, error; |
| 3610 | |
| 3611 | to_nodeid = r->res_nodeid; |
| 3612 | |
| 3613 | error = add_to_waiters(lkb, mstype, to_nodeid); |
| 3614 | if (error) |
| 3615 | return error; |
| 3616 | |
| 3617 | error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh); |
| 3618 | if (error) |
| 3619 | goto fail; |
| 3620 | |
| 3621 | send_args(r, lkb, ms); |
| 3622 | |
| 3623 | error = send_message(mh, ms, r->res_name, r->res_length); |
| 3624 | if (error) |
| 3625 | goto fail; |
| 3626 | return 0; |
| 3627 | |
| 3628 | fail: |
| 3629 | remove_from_waiters(lkb, msg_reply_type(mstype)); |
| 3630 | return error; |
| 3631 | } |
| 3632 | |
| 3633 | static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3634 | { |
| 3635 | return send_common(r, lkb, DLM_MSG_REQUEST); |
| 3636 | } |
| 3637 | |
| 3638 | static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3639 | { |
| 3640 | int error; |
| 3641 | |
| 3642 | error = send_common(r, lkb, DLM_MSG_CONVERT); |
| 3643 | |
| 3644 | /* down conversions go without a reply from the master */ |
| 3645 | if (!error && down_conversion(lkb)) { |
| 3646 | remove_from_waiters(lkb, DLM_MSG_CONVERT_REPLY); |
| 3647 | r->res_ls->ls_local_ms.m_type = cpu_to_le32(DLM_MSG_CONVERT_REPLY); |
| 3648 | r->res_ls->ls_local_ms.m_result = 0; |
| 3649 | __receive_convert_reply(r, lkb, &r->res_ls->ls_local_ms, true); |
| 3650 | } |
| 3651 | |
| 3652 | return error; |
| 3653 | } |
| 3654 | |
| 3655 | /* FIXME: if this lkb is the only lock we hold on the rsb, then set |
| 3656 | MASTER_UNCERTAIN to force the next request on the rsb to confirm |
| 3657 | that the master is still correct. */ |
| 3658 | |
| 3659 | static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3660 | { |
| 3661 | return send_common(r, lkb, DLM_MSG_UNLOCK); |
| 3662 | } |
| 3663 | |
| 3664 | static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3665 | { |
| 3666 | return send_common(r, lkb, DLM_MSG_CANCEL); |
| 3667 | } |
| 3668 | |
| 3669 | static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3670 | { |
| 3671 | struct dlm_message *ms; |
| 3672 | struct dlm_mhandle *mh; |
| 3673 | int to_nodeid, error; |
| 3674 | |
| 3675 | to_nodeid = lkb->lkb_nodeid; |
| 3676 | |
| 3677 | error = create_message(r, lkb, to_nodeid, DLM_MSG_GRANT, &ms, &mh); |
| 3678 | if (error) |
| 3679 | goto out; |
| 3680 | |
| 3681 | send_args(r, lkb, ms); |
| 3682 | |
| 3683 | ms->m_result = 0; |
| 3684 | |
| 3685 | error = send_message(mh, ms, r->res_name, r->res_length); |
| 3686 | out: |
| 3687 | return error; |
| 3688 | } |
| 3689 | |
| 3690 | static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode) |
| 3691 | { |
| 3692 | struct dlm_message *ms; |
| 3693 | struct dlm_mhandle *mh; |
| 3694 | int to_nodeid, error; |
| 3695 | |
| 3696 | to_nodeid = lkb->lkb_nodeid; |
| 3697 | |
| 3698 | error = create_message(r, NULL, to_nodeid, DLM_MSG_BAST, &ms, &mh); |
| 3699 | if (error) |
| 3700 | goto out; |
| 3701 | |
| 3702 | send_args(r, lkb, ms); |
| 3703 | |
| 3704 | ms->m_bastmode = cpu_to_le32(mode); |
| 3705 | |
| 3706 | error = send_message(mh, ms, r->res_name, r->res_length); |
| 3707 | out: |
| 3708 | return error; |
| 3709 | } |
| 3710 | |
| 3711 | static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb) |
| 3712 | { |
| 3713 | struct dlm_message *ms; |
| 3714 | struct dlm_mhandle *mh; |
| 3715 | int to_nodeid, error; |
| 3716 | |
| 3717 | to_nodeid = dlm_dir_nodeid(r); |
| 3718 | |
| 3719 | error = add_to_waiters(lkb, DLM_MSG_LOOKUP, to_nodeid); |
| 3720 | if (error) |
| 3721 | return error; |
| 3722 | |
| 3723 | error = create_message(r, NULL, to_nodeid, DLM_MSG_LOOKUP, &ms, &mh); |
| 3724 | if (error) |
| 3725 | goto fail; |
| 3726 | |
| 3727 | send_args(r, lkb, ms); |
| 3728 | |
| 3729 | error = send_message(mh, ms, r->res_name, r->res_length); |
| 3730 | if (error) |
| 3731 | goto fail; |
| 3732 | return 0; |
| 3733 | |
| 3734 | fail: |
| 3735 | remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY); |
| 3736 | return error; |
| 3737 | } |
| 3738 | |
| 3739 | static int send_remove(struct dlm_rsb *r) |
| 3740 | { |
| 3741 | struct dlm_message *ms; |
| 3742 | struct dlm_mhandle *mh; |
| 3743 | int to_nodeid, error; |
| 3744 | |
| 3745 | to_nodeid = dlm_dir_nodeid(r); |
| 3746 | |
| 3747 | error = create_message(r, NULL, to_nodeid, DLM_MSG_REMOVE, &ms, &mh); |
| 3748 | if (error) |
| 3749 | goto out; |
| 3750 | |
| 3751 | memcpy(ms->m_extra, r->res_name, r->res_length); |
| 3752 | ms->m_hash = cpu_to_le32(r->res_hash); |
| 3753 | |
| 3754 | error = send_message(mh, ms, r->res_name, r->res_length); |
| 3755 | out: |
| 3756 | return error; |
| 3757 | } |
| 3758 | |
| 3759 | static int send_common_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, |
| 3760 | int mstype, int rv) |
| 3761 | { |
| 3762 | struct dlm_message *ms; |
| 3763 | struct dlm_mhandle *mh; |
| 3764 | int to_nodeid, error; |
| 3765 | |
| 3766 | to_nodeid = lkb->lkb_nodeid; |
| 3767 | |
| 3768 | error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh); |
| 3769 | if (error) |
| 3770 | goto out; |
| 3771 | |
| 3772 | send_args(r, lkb, ms); |
| 3773 | |
| 3774 | ms->m_result = cpu_to_le32(to_dlm_errno(rv)); |
| 3775 | |
| 3776 | error = send_message(mh, ms, r->res_name, r->res_length); |
| 3777 | out: |
| 3778 | return error; |
| 3779 | } |
| 3780 | |
| 3781 | static int send_request_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) |
| 3782 | { |
| 3783 | return send_common_reply(r, lkb, DLM_MSG_REQUEST_REPLY, rv); |
| 3784 | } |
| 3785 | |
| 3786 | static int send_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) |
| 3787 | { |
| 3788 | return send_common_reply(r, lkb, DLM_MSG_CONVERT_REPLY, rv); |
| 3789 | } |
| 3790 | |
| 3791 | static int send_unlock_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) |
| 3792 | { |
| 3793 | return send_common_reply(r, lkb, DLM_MSG_UNLOCK_REPLY, rv); |
| 3794 | } |
| 3795 | |
| 3796 | static int send_cancel_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) |
| 3797 | { |
| 3798 | return send_common_reply(r, lkb, DLM_MSG_CANCEL_REPLY, rv); |
| 3799 | } |
| 3800 | |
| 3801 | static int send_lookup_reply(struct dlm_ls *ls, |
| 3802 | const struct dlm_message *ms_in, int ret_nodeid, |
| 3803 | int rv) |
| 3804 | { |
| 3805 | struct dlm_rsb *r = &ls->ls_local_rsb; |
| 3806 | struct dlm_message *ms; |
| 3807 | struct dlm_mhandle *mh; |
| 3808 | int error, nodeid = le32_to_cpu(ms_in->m_header.h_nodeid); |
| 3809 | |
| 3810 | error = create_message(r, NULL, nodeid, DLM_MSG_LOOKUP_REPLY, &ms, &mh); |
| 3811 | if (error) |
| 3812 | goto out; |
| 3813 | |
| 3814 | ms->m_lkid = ms_in->m_lkid; |
| 3815 | ms->m_result = cpu_to_le32(to_dlm_errno(rv)); |
| 3816 | ms->m_nodeid = cpu_to_le32(ret_nodeid); |
| 3817 | |
| 3818 | error = send_message(mh, ms, ms_in->m_extra, receive_extralen(ms_in)); |
| 3819 | out: |
| 3820 | return error; |
| 3821 | } |
| 3822 | |
| 3823 | /* which args we save from a received message depends heavily on the type |
| 3824 | of message, unlike the send side where we can safely send everything about |
| 3825 | the lkb for any type of message */ |
| 3826 | |
| 3827 | static void receive_flags(struct dlm_lkb *lkb, const struct dlm_message *ms) |
| 3828 | { |
| 3829 | lkb->lkb_exflags = le32_to_cpu(ms->m_exflags); |
| 3830 | dlm_set_sbflags_val(lkb, le32_to_cpu(ms->m_sbflags)); |
| 3831 | dlm_set_dflags_val(lkb, le32_to_cpu(ms->m_flags)); |
| 3832 | } |
| 3833 | |
| 3834 | static void receive_flags_reply(struct dlm_lkb *lkb, |
| 3835 | const struct dlm_message *ms, |
| 3836 | bool local) |
| 3837 | { |
| 3838 | if (local) |
| 3839 | return; |
| 3840 | |
| 3841 | dlm_set_sbflags_val(lkb, le32_to_cpu(ms->m_sbflags)); |
| 3842 | dlm_set_dflags_val(lkb, le32_to_cpu(ms->m_flags)); |
| 3843 | } |
| 3844 | |
| 3845 | static int receive_extralen(const struct dlm_message *ms) |
| 3846 | { |
| 3847 | return (le16_to_cpu(ms->m_header.h_length) - |
| 3848 | sizeof(struct dlm_message)); |
| 3849 | } |
| 3850 | |
| 3851 | static int receive_lvb(struct dlm_ls *ls, struct dlm_lkb *lkb, |
| 3852 | const struct dlm_message *ms) |
| 3853 | { |
| 3854 | int len; |
| 3855 | |
| 3856 | if (lkb->lkb_exflags & DLM_LKF_VALBLK) { |
| 3857 | if (!lkb->lkb_lvbptr) |
| 3858 | lkb->lkb_lvbptr = dlm_allocate_lvb(ls); |
| 3859 | if (!lkb->lkb_lvbptr) |
| 3860 | return -ENOMEM; |
| 3861 | len = receive_extralen(ms); |
| 3862 | if (len > ls->ls_lvblen) |
| 3863 | len = ls->ls_lvblen; |
| 3864 | memcpy(lkb->lkb_lvbptr, ms->m_extra, len); |
| 3865 | } |
| 3866 | return 0; |
| 3867 | } |
| 3868 | |
| 3869 | static void fake_bastfn(void *astparam, int mode) |
| 3870 | { |
| 3871 | log_print("fake_bastfn should not be called"); |
| 3872 | } |
| 3873 | |
| 3874 | static void fake_astfn(void *astparam) |
| 3875 | { |
| 3876 | log_print("fake_astfn should not be called"); |
| 3877 | } |
| 3878 | |
| 3879 | static int receive_request_args(struct dlm_ls *ls, struct dlm_lkb *lkb, |
| 3880 | const struct dlm_message *ms) |
| 3881 | { |
| 3882 | lkb->lkb_nodeid = le32_to_cpu(ms->m_header.h_nodeid); |
| 3883 | lkb->lkb_ownpid = le32_to_cpu(ms->m_pid); |
| 3884 | lkb->lkb_remid = le32_to_cpu(ms->m_lkid); |
| 3885 | lkb->lkb_grmode = DLM_LOCK_IV; |
| 3886 | lkb->lkb_rqmode = le32_to_cpu(ms->m_rqmode); |
| 3887 | |
| 3888 | lkb->lkb_bastfn = (ms->m_asts & cpu_to_le32(DLM_CB_BAST)) ? &fake_bastfn : NULL; |
| 3889 | lkb->lkb_astfn = (ms->m_asts & cpu_to_le32(DLM_CB_CAST)) ? &fake_astfn : NULL; |
| 3890 | |
| 3891 | if (lkb->lkb_exflags & DLM_LKF_VALBLK) { |
| 3892 | /* lkb was just created so there won't be an lvb yet */ |
| 3893 | lkb->lkb_lvbptr = dlm_allocate_lvb(ls); |
| 3894 | if (!lkb->lkb_lvbptr) |
| 3895 | return -ENOMEM; |
| 3896 | } |
| 3897 | |
| 3898 | return 0; |
| 3899 | } |
| 3900 | |
| 3901 | static int receive_convert_args(struct dlm_ls *ls, struct dlm_lkb *lkb, |
| 3902 | const struct dlm_message *ms) |
| 3903 | { |
| 3904 | if (lkb->lkb_status != DLM_LKSTS_GRANTED) |
| 3905 | return -EBUSY; |
| 3906 | |
| 3907 | if (receive_lvb(ls, lkb, ms)) |
| 3908 | return -ENOMEM; |
| 3909 | |
| 3910 | lkb->lkb_rqmode = le32_to_cpu(ms->m_rqmode); |
| 3911 | lkb->lkb_lvbseq = le32_to_cpu(ms->m_lvbseq); |
| 3912 | |
| 3913 | return 0; |
| 3914 | } |
| 3915 | |
| 3916 | static int receive_unlock_args(struct dlm_ls *ls, struct dlm_lkb *lkb, |
| 3917 | const struct dlm_message *ms) |
| 3918 | { |
| 3919 | if (receive_lvb(ls, lkb, ms)) |
| 3920 | return -ENOMEM; |
| 3921 | return 0; |
| 3922 | } |
| 3923 | |
| 3924 | /* We fill in the local-lkb fields with the info that send_xxxx_reply() |
| 3925 | uses to send a reply and that the remote end uses to process the reply. */ |
| 3926 | |
| 3927 | static void setup_local_lkb(struct dlm_ls *ls, const struct dlm_message *ms) |
| 3928 | { |
| 3929 | struct dlm_lkb *lkb = &ls->ls_local_lkb; |
| 3930 | lkb->lkb_nodeid = le32_to_cpu(ms->m_header.h_nodeid); |
| 3931 | lkb->lkb_remid = le32_to_cpu(ms->m_lkid); |
| 3932 | } |
| 3933 | |
| 3934 | /* This is called after the rsb is locked so that we can safely inspect |
| 3935 | fields in the lkb. */ |
| 3936 | |
| 3937 | static int validate_message(struct dlm_lkb *lkb, const struct dlm_message *ms) |
| 3938 | { |
| 3939 | int from = le32_to_cpu(ms->m_header.h_nodeid); |
| 3940 | int error = 0; |
| 3941 | |
| 3942 | /* currently mixing of user/kernel locks are not supported */ |
| 3943 | if (ms->m_flags & cpu_to_le32(BIT(DLM_DFL_USER_BIT)) && |
| 3944 | !test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) { |
| 3945 | log_error(lkb->lkb_resource->res_ls, |
| 3946 | "got user dlm message for a kernel lock"); |
| 3947 | error = -EINVAL; |
| 3948 | goto out; |
| 3949 | } |
| 3950 | |
| 3951 | switch (ms->m_type) { |
| 3952 | case cpu_to_le32(DLM_MSG_CONVERT): |
| 3953 | case cpu_to_le32(DLM_MSG_UNLOCK): |
| 3954 | case cpu_to_le32(DLM_MSG_CANCEL): |
| 3955 | if (!is_master_copy(lkb) || lkb->lkb_nodeid != from) |
| 3956 | error = -EINVAL; |
| 3957 | break; |
| 3958 | |
| 3959 | case cpu_to_le32(DLM_MSG_CONVERT_REPLY): |
| 3960 | case cpu_to_le32(DLM_MSG_UNLOCK_REPLY): |
| 3961 | case cpu_to_le32(DLM_MSG_CANCEL_REPLY): |
| 3962 | case cpu_to_le32(DLM_MSG_GRANT): |
| 3963 | case cpu_to_le32(DLM_MSG_BAST): |
| 3964 | if (!is_process_copy(lkb) || lkb->lkb_nodeid != from) |
| 3965 | error = -EINVAL; |
| 3966 | break; |
| 3967 | |
| 3968 | case cpu_to_le32(DLM_MSG_REQUEST_REPLY): |
| 3969 | if (!is_process_copy(lkb)) |
| 3970 | error = -EINVAL; |
| 3971 | else if (lkb->lkb_nodeid != -1 && lkb->lkb_nodeid != from) |
| 3972 | error = -EINVAL; |
| 3973 | break; |
| 3974 | |
| 3975 | default: |
| 3976 | error = -EINVAL; |
| 3977 | } |
| 3978 | |
| 3979 | out: |
| 3980 | if (error) |
| 3981 | log_error(lkb->lkb_resource->res_ls, |
| 3982 | "ignore invalid message %d from %d %x %x %x %d", |
| 3983 | le32_to_cpu(ms->m_type), from, lkb->lkb_id, |
| 3984 | lkb->lkb_remid, dlm_iflags_val(lkb), |
| 3985 | lkb->lkb_nodeid); |
| 3986 | return error; |
| 3987 | } |
| 3988 | |
| 3989 | static int receive_request(struct dlm_ls *ls, const struct dlm_message *ms) |
| 3990 | { |
| 3991 | struct dlm_lkb *lkb; |
| 3992 | struct dlm_rsb *r; |
| 3993 | int from_nodeid; |
| 3994 | int error, namelen = 0; |
| 3995 | |
| 3996 | from_nodeid = le32_to_cpu(ms->m_header.h_nodeid); |
| 3997 | |
| 3998 | error = create_lkb(ls, &lkb); |
| 3999 | if (error) |
| 4000 | goto fail; |
| 4001 | |
| 4002 | receive_flags(lkb, ms); |
| 4003 | set_bit(DLM_IFL_MSTCPY_BIT, &lkb->lkb_iflags); |
| 4004 | error = receive_request_args(ls, lkb, ms); |
| 4005 | if (error) { |
| 4006 | __put_lkb(ls, lkb); |
| 4007 | goto fail; |
| 4008 | } |
| 4009 | |
| 4010 | /* The dir node is the authority on whether we are the master |
| 4011 | for this rsb or not, so if the master sends us a request, we should |
| 4012 | recreate the rsb if we've destroyed it. This race happens when we |
| 4013 | send a remove message to the dir node at the same time that the dir |
| 4014 | node sends us a request for the rsb. */ |
| 4015 | |
| 4016 | namelen = receive_extralen(ms); |
| 4017 | |
| 4018 | error = find_rsb(ls, ms->m_extra, namelen, from_nodeid, |
| 4019 | R_RECEIVE_REQUEST, &r); |
| 4020 | if (error) { |
| 4021 | __put_lkb(ls, lkb); |
| 4022 | goto fail; |
| 4023 | } |
| 4024 | |
| 4025 | lock_rsb(r); |
| 4026 | |
| 4027 | if (r->res_master_nodeid != dlm_our_nodeid()) { |
| 4028 | error = validate_master_nodeid(ls, r, from_nodeid); |
| 4029 | if (error) { |
| 4030 | unlock_rsb(r); |
| 4031 | put_rsb(r); |
| 4032 | __put_lkb(ls, lkb); |
| 4033 | goto fail; |
| 4034 | } |
| 4035 | } |
| 4036 | |
| 4037 | attach_lkb(r, lkb); |
| 4038 | error = do_request(r, lkb); |
| 4039 | send_request_reply(r, lkb, error); |
| 4040 | do_request_effects(r, lkb, error); |
| 4041 | |
| 4042 | unlock_rsb(r); |
| 4043 | put_rsb(r); |
| 4044 | |
| 4045 | if (error == -EINPROGRESS) |
| 4046 | error = 0; |
| 4047 | if (error) |
| 4048 | dlm_put_lkb(lkb); |
| 4049 | return 0; |
| 4050 | |
| 4051 | fail: |
| 4052 | /* TODO: instead of returning ENOTBLK, add the lkb to res_lookup |
| 4053 | and do this receive_request again from process_lookup_list once |
| 4054 | we get the lookup reply. This would avoid a many repeated |
| 4055 | ENOTBLK request failures when the lookup reply designating us |
| 4056 | as master is delayed. */ |
| 4057 | |
| 4058 | if (error != -ENOTBLK) { |
| 4059 | log_limit(ls, "receive_request %x from %d %d", |
| 4060 | le32_to_cpu(ms->m_lkid), from_nodeid, error); |
| 4061 | } |
| 4062 | |
| 4063 | setup_local_lkb(ls, ms); |
| 4064 | send_request_reply(&ls->ls_local_rsb, &ls->ls_local_lkb, error); |
| 4065 | return error; |
| 4066 | } |
| 4067 | |
| 4068 | static int receive_convert(struct dlm_ls *ls, const struct dlm_message *ms) |
| 4069 | { |
| 4070 | struct dlm_lkb *lkb; |
| 4071 | struct dlm_rsb *r; |
| 4072 | int error, reply = 1; |
| 4073 | |
| 4074 | error = find_lkb(ls, le32_to_cpu(ms->m_remid), &lkb); |
| 4075 | if (error) |
| 4076 | goto fail; |
| 4077 | |
| 4078 | if (lkb->lkb_remid != le32_to_cpu(ms->m_lkid)) { |
| 4079 | log_error(ls, "receive_convert %x remid %x recover_seq %llu " |
| 4080 | "remote %d %x", lkb->lkb_id, lkb->lkb_remid, |
| 4081 | (unsigned long long)lkb->lkb_recover_seq, |
| 4082 | le32_to_cpu(ms->m_header.h_nodeid), |
| 4083 | le32_to_cpu(ms->m_lkid)); |
| 4084 | error = -ENOENT; |
| 4085 | dlm_put_lkb(lkb); |
| 4086 | goto fail; |
| 4087 | } |
| 4088 | |
| 4089 | r = lkb->lkb_resource; |
| 4090 | |
| 4091 | hold_rsb(r); |
| 4092 | lock_rsb(r); |
| 4093 | |
| 4094 | error = validate_message(lkb, ms); |
| 4095 | if (error) |
| 4096 | goto out; |
| 4097 | |
| 4098 | receive_flags(lkb, ms); |
| 4099 | |
| 4100 | error = receive_convert_args(ls, lkb, ms); |
| 4101 | if (error) { |
| 4102 | send_convert_reply(r, lkb, error); |
| 4103 | goto out; |
| 4104 | } |
| 4105 | |
| 4106 | reply = !down_conversion(lkb); |
| 4107 | |
| 4108 | error = do_convert(r, lkb); |
| 4109 | if (reply) |
| 4110 | send_convert_reply(r, lkb, error); |
| 4111 | do_convert_effects(r, lkb, error); |
| 4112 | out: |
| 4113 | unlock_rsb(r); |
| 4114 | put_rsb(r); |
| 4115 | dlm_put_lkb(lkb); |
| 4116 | return 0; |
| 4117 | |
| 4118 | fail: |
| 4119 | setup_local_lkb(ls, ms); |
| 4120 | send_convert_reply(&ls->ls_local_rsb, &ls->ls_local_lkb, error); |
| 4121 | return error; |
| 4122 | } |
| 4123 | |
| 4124 | static int receive_unlock(struct dlm_ls *ls, const struct dlm_message *ms) |
| 4125 | { |
| 4126 | struct dlm_lkb *lkb; |
| 4127 | struct dlm_rsb *r; |
| 4128 | int error; |
| 4129 | |
| 4130 | error = find_lkb(ls, le32_to_cpu(ms->m_remid), &lkb); |
| 4131 | if (error) |
| 4132 | goto fail; |
| 4133 | |
| 4134 | if (lkb->lkb_remid != le32_to_cpu(ms->m_lkid)) { |
| 4135 | log_error(ls, "receive_unlock %x remid %x remote %d %x", |
| 4136 | lkb->lkb_id, lkb->lkb_remid, |
| 4137 | le32_to_cpu(ms->m_header.h_nodeid), |
| 4138 | le32_to_cpu(ms->m_lkid)); |
| 4139 | error = -ENOENT; |
| 4140 | dlm_put_lkb(lkb); |
| 4141 | goto fail; |
| 4142 | } |
| 4143 | |
| 4144 | r = lkb->lkb_resource; |
| 4145 | |
| 4146 | hold_rsb(r); |
| 4147 | lock_rsb(r); |
| 4148 | |
| 4149 | error = validate_message(lkb, ms); |
| 4150 | if (error) |
| 4151 | goto out; |
| 4152 | |
| 4153 | receive_flags(lkb, ms); |
| 4154 | |
| 4155 | error = receive_unlock_args(ls, lkb, ms); |
| 4156 | if (error) { |
| 4157 | send_unlock_reply(r, lkb, error); |
| 4158 | goto out; |
| 4159 | } |
| 4160 | |
| 4161 | error = do_unlock(r, lkb); |
| 4162 | send_unlock_reply(r, lkb, error); |
| 4163 | do_unlock_effects(r, lkb, error); |
| 4164 | out: |
| 4165 | unlock_rsb(r); |
| 4166 | put_rsb(r); |
| 4167 | dlm_put_lkb(lkb); |
| 4168 | return 0; |
| 4169 | |
| 4170 | fail: |
| 4171 | setup_local_lkb(ls, ms); |
| 4172 | send_unlock_reply(&ls->ls_local_rsb, &ls->ls_local_lkb, error); |
| 4173 | return error; |
| 4174 | } |
| 4175 | |
| 4176 | static int receive_cancel(struct dlm_ls *ls, const struct dlm_message *ms) |
| 4177 | { |
| 4178 | struct dlm_lkb *lkb; |
| 4179 | struct dlm_rsb *r; |
| 4180 | int error; |
| 4181 | |
| 4182 | error = find_lkb(ls, le32_to_cpu(ms->m_remid), &lkb); |
| 4183 | if (error) |
| 4184 | goto fail; |
| 4185 | |
| 4186 | receive_flags(lkb, ms); |
| 4187 | |
| 4188 | r = lkb->lkb_resource; |
| 4189 | |
| 4190 | hold_rsb(r); |
| 4191 | lock_rsb(r); |
| 4192 | |
| 4193 | error = validate_message(lkb, ms); |
| 4194 | if (error) |
| 4195 | goto out; |
| 4196 | |
| 4197 | error = do_cancel(r, lkb); |
| 4198 | send_cancel_reply(r, lkb, error); |
| 4199 | do_cancel_effects(r, lkb, error); |
| 4200 | out: |
| 4201 | unlock_rsb(r); |
| 4202 | put_rsb(r); |
| 4203 | dlm_put_lkb(lkb); |
| 4204 | return 0; |
| 4205 | |
| 4206 | fail: |
| 4207 | setup_local_lkb(ls, ms); |
| 4208 | send_cancel_reply(&ls->ls_local_rsb, &ls->ls_local_lkb, error); |
| 4209 | return error; |
| 4210 | } |
| 4211 | |
| 4212 | static int receive_grant(struct dlm_ls *ls, const struct dlm_message *ms) |
| 4213 | { |
| 4214 | struct dlm_lkb *lkb; |
| 4215 | struct dlm_rsb *r; |
| 4216 | int error; |
| 4217 | |
| 4218 | error = find_lkb(ls, le32_to_cpu(ms->m_remid), &lkb); |
| 4219 | if (error) |
| 4220 | return error; |
| 4221 | |
| 4222 | r = lkb->lkb_resource; |
| 4223 | |
| 4224 | hold_rsb(r); |
| 4225 | lock_rsb(r); |
| 4226 | |
| 4227 | error = validate_message(lkb, ms); |
| 4228 | if (error) |
| 4229 | goto out; |
| 4230 | |
| 4231 | receive_flags_reply(lkb, ms, false); |
| 4232 | if (is_altmode(lkb)) |
| 4233 | munge_altmode(lkb, ms); |
| 4234 | grant_lock_pc(r, lkb, ms); |
| 4235 | queue_cast(r, lkb, 0); |
| 4236 | out: |
| 4237 | unlock_rsb(r); |
| 4238 | put_rsb(r); |
| 4239 | dlm_put_lkb(lkb); |
| 4240 | return 0; |
| 4241 | } |
| 4242 | |
| 4243 | static int receive_bast(struct dlm_ls *ls, const struct dlm_message *ms) |
| 4244 | { |
| 4245 | struct dlm_lkb *lkb; |
| 4246 | struct dlm_rsb *r; |
| 4247 | int error; |
| 4248 | |
| 4249 | error = find_lkb(ls, le32_to_cpu(ms->m_remid), &lkb); |
| 4250 | if (error) |
| 4251 | return error; |
| 4252 | |
| 4253 | r = lkb->lkb_resource; |
| 4254 | |
| 4255 | hold_rsb(r); |
| 4256 | lock_rsb(r); |
| 4257 | |
| 4258 | error = validate_message(lkb, ms); |
| 4259 | if (error) |
| 4260 | goto out; |
| 4261 | |
| 4262 | queue_bast(r, lkb, le32_to_cpu(ms->m_bastmode)); |
| 4263 | lkb->lkb_highbast = le32_to_cpu(ms->m_bastmode); |
| 4264 | out: |
| 4265 | unlock_rsb(r); |
| 4266 | put_rsb(r); |
| 4267 | dlm_put_lkb(lkb); |
| 4268 | return 0; |
| 4269 | } |
| 4270 | |
| 4271 | static void receive_lookup(struct dlm_ls *ls, const struct dlm_message *ms) |
| 4272 | { |
| 4273 | int len, error, ret_nodeid, from_nodeid, our_nodeid; |
| 4274 | |
| 4275 | from_nodeid = le32_to_cpu(ms->m_header.h_nodeid); |
| 4276 | our_nodeid = dlm_our_nodeid(); |
| 4277 | |
| 4278 | len = receive_extralen(ms); |
| 4279 | |
| 4280 | error = dlm_master_lookup(ls, from_nodeid, ms->m_extra, len, 0, |
| 4281 | &ret_nodeid, NULL); |
| 4282 | |
| 4283 | /* Optimization: we're master so treat lookup as a request */ |
| 4284 | if (!error && ret_nodeid == our_nodeid) { |
| 4285 | receive_request(ls, ms); |
| 4286 | return; |
| 4287 | } |
| 4288 | send_lookup_reply(ls, ms, ret_nodeid, error); |
| 4289 | } |
| 4290 | |
| 4291 | static void receive_remove(struct dlm_ls *ls, const struct dlm_message *ms) |
| 4292 | { |
| 4293 | char name[DLM_RESNAME_MAXLEN+1]; |
| 4294 | struct dlm_rsb *r; |
| 4295 | int rv, len, dir_nodeid, from_nodeid; |
| 4296 | |
| 4297 | from_nodeid = le32_to_cpu(ms->m_header.h_nodeid); |
| 4298 | |
| 4299 | len = receive_extralen(ms); |
| 4300 | |
| 4301 | if (len > DLM_RESNAME_MAXLEN) { |
| 4302 | log_error(ls, "receive_remove from %d bad len %d", |
| 4303 | from_nodeid, len); |
| 4304 | return; |
| 4305 | } |
| 4306 | |
| 4307 | dir_nodeid = dlm_hash2nodeid(ls, le32_to_cpu(ms->m_hash)); |
| 4308 | if (dir_nodeid != dlm_our_nodeid()) { |
| 4309 | log_error(ls, "receive_remove from %d bad nodeid %d", |
| 4310 | from_nodeid, dir_nodeid); |
| 4311 | return; |
| 4312 | } |
| 4313 | |
| 4314 | /* |
| 4315 | * Look for inactive rsb, if it's there, free it. |
| 4316 | * If the rsb is active, it's being used, and we should ignore this |
| 4317 | * message. This is an expected race between the dir node sending a |
| 4318 | * request to the master node at the same time as the master node sends |
| 4319 | * a remove to the dir node. The resolution to that race is for the |
| 4320 | * dir node to ignore the remove message, and the master node to |
| 4321 | * recreate the master rsb when it gets a request from the dir node for |
| 4322 | * an rsb it doesn't have. |
| 4323 | */ |
| 4324 | |
| 4325 | memset(name, 0, sizeof(name)); |
| 4326 | memcpy(name, ms->m_extra, len); |
| 4327 | |
| 4328 | rcu_read_lock(); |
| 4329 | rv = dlm_search_rsb_tree(&ls->ls_rsbtbl, name, len, &r); |
| 4330 | if (rv) { |
| 4331 | rcu_read_unlock(); |
| 4332 | /* should not happen */ |
| 4333 | log_error(ls, "%s from %d not found %s", __func__, |
| 4334 | from_nodeid, name); |
| 4335 | return; |
| 4336 | } |
| 4337 | |
| 4338 | write_lock_bh(&ls->ls_rsbtbl_lock); |
| 4339 | if (!rsb_flag(r, RSB_HASHED)) { |
| 4340 | rcu_read_unlock(); |
| 4341 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 4342 | /* should not happen */ |
| 4343 | log_error(ls, "%s from %d got removed during removal %s", |
| 4344 | __func__, from_nodeid, name); |
| 4345 | return; |
| 4346 | } |
| 4347 | /* at this stage the rsb can only being freed here */ |
| 4348 | rcu_read_unlock(); |
| 4349 | |
| 4350 | if (!rsb_flag(r, RSB_INACTIVE)) { |
| 4351 | if (r->res_master_nodeid != from_nodeid) { |
| 4352 | /* should not happen */ |
| 4353 | log_error(ls, "receive_remove on active rsb from %d master %d", |
| 4354 | from_nodeid, r->res_master_nodeid); |
| 4355 | dlm_print_rsb(r); |
| 4356 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 4357 | return; |
| 4358 | } |
| 4359 | |
| 4360 | /* Ignore the remove message, see race comment above. */ |
| 4361 | |
| 4362 | log_debug(ls, "receive_remove from %d master %d first %x %s", |
| 4363 | from_nodeid, r->res_master_nodeid, r->res_first_lkid, |
| 4364 | name); |
| 4365 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 4366 | return; |
| 4367 | } |
| 4368 | |
| 4369 | if (r->res_master_nodeid != from_nodeid) { |
| 4370 | log_error(ls, "receive_remove inactive from %d master %d", |
| 4371 | from_nodeid, r->res_master_nodeid); |
| 4372 | dlm_print_rsb(r); |
| 4373 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 4374 | return; |
| 4375 | } |
| 4376 | |
| 4377 | list_del(&r->res_slow_list); |
| 4378 | rhashtable_remove_fast(&ls->ls_rsbtbl, &r->res_node, |
| 4379 | dlm_rhash_rsb_params); |
| 4380 | rsb_clear_flag(r, RSB_HASHED); |
| 4381 | write_unlock_bh(&ls->ls_rsbtbl_lock); |
| 4382 | |
| 4383 | free_inactive_rsb(r); |
| 4384 | } |
| 4385 | |
| 4386 | static void receive_purge(struct dlm_ls *ls, const struct dlm_message *ms) |
| 4387 | { |
| 4388 | do_purge(ls, le32_to_cpu(ms->m_nodeid), le32_to_cpu(ms->m_pid)); |
| 4389 | } |
| 4390 | |
| 4391 | static int receive_request_reply(struct dlm_ls *ls, |
| 4392 | const struct dlm_message *ms) |
| 4393 | { |
| 4394 | struct dlm_lkb *lkb; |
| 4395 | struct dlm_rsb *r; |
| 4396 | int error, mstype, result; |
| 4397 | int from_nodeid = le32_to_cpu(ms->m_header.h_nodeid); |
| 4398 | |
| 4399 | error = find_lkb(ls, le32_to_cpu(ms->m_remid), &lkb); |
| 4400 | if (error) |
| 4401 | return error; |
| 4402 | |
| 4403 | r = lkb->lkb_resource; |
| 4404 | hold_rsb(r); |
| 4405 | lock_rsb(r); |
| 4406 | |
| 4407 | error = validate_message(lkb, ms); |
| 4408 | if (error) |
| 4409 | goto out; |
| 4410 | |
| 4411 | mstype = lkb->lkb_wait_type; |
| 4412 | error = remove_from_waiters(lkb, DLM_MSG_REQUEST_REPLY); |
| 4413 | if (error) { |
| 4414 | log_error(ls, "receive_request_reply %x remote %d %x result %d", |
| 4415 | lkb->lkb_id, from_nodeid, le32_to_cpu(ms->m_lkid), |
| 4416 | from_dlm_errno(le32_to_cpu(ms->m_result))); |
| 4417 | dlm_dump_rsb(r); |
| 4418 | goto out; |
| 4419 | } |
| 4420 | |
| 4421 | /* Optimization: the dir node was also the master, so it took our |
| 4422 | lookup as a request and sent request reply instead of lookup reply */ |
| 4423 | if (mstype == DLM_MSG_LOOKUP) { |
| 4424 | r->res_master_nodeid = from_nodeid; |
| 4425 | r->res_nodeid = from_nodeid; |
| 4426 | lkb->lkb_nodeid = from_nodeid; |
| 4427 | } |
| 4428 | |
| 4429 | /* this is the value returned from do_request() on the master */ |
| 4430 | result = from_dlm_errno(le32_to_cpu(ms->m_result)); |
| 4431 | |
| 4432 | switch (result) { |
| 4433 | case -EAGAIN: |
| 4434 | /* request would block (be queued) on remote master */ |
| 4435 | queue_cast(r, lkb, -EAGAIN); |
| 4436 | confirm_master(r, -EAGAIN); |
| 4437 | unhold_lkb(lkb); /* undoes create_lkb() */ |
| 4438 | break; |
| 4439 | |
| 4440 | case -EINPROGRESS: |
| 4441 | case 0: |
| 4442 | /* request was queued or granted on remote master */ |
| 4443 | receive_flags_reply(lkb, ms, false); |
| 4444 | lkb->lkb_remid = le32_to_cpu(ms->m_lkid); |
| 4445 | if (is_altmode(lkb)) |
| 4446 | munge_altmode(lkb, ms); |
| 4447 | if (result) { |
| 4448 | add_lkb(r, lkb, DLM_LKSTS_WAITING); |
| 4449 | } else { |
| 4450 | grant_lock_pc(r, lkb, ms); |
| 4451 | queue_cast(r, lkb, 0); |
| 4452 | } |
| 4453 | confirm_master(r, result); |
| 4454 | break; |
| 4455 | |
| 4456 | case -EBADR: |
| 4457 | case -ENOTBLK: |
| 4458 | /* find_rsb failed to find rsb or rsb wasn't master */ |
| 4459 | log_limit(ls, "receive_request_reply %x from %d %d " |
| 4460 | "master %d dir %d first %x %s", lkb->lkb_id, |
| 4461 | from_nodeid, result, r->res_master_nodeid, |
| 4462 | r->res_dir_nodeid, r->res_first_lkid, r->res_name); |
| 4463 | |
| 4464 | if (r->res_dir_nodeid != dlm_our_nodeid() && |
| 4465 | r->res_master_nodeid != dlm_our_nodeid()) { |
| 4466 | /* cause _request_lock->set_master->send_lookup */ |
| 4467 | r->res_master_nodeid = 0; |
| 4468 | r->res_nodeid = -1; |
| 4469 | lkb->lkb_nodeid = -1; |
| 4470 | } |
| 4471 | |
| 4472 | if (is_overlap(lkb)) { |
| 4473 | /* we'll ignore error in cancel/unlock reply */ |
| 4474 | queue_cast_overlap(r, lkb); |
| 4475 | confirm_master(r, result); |
| 4476 | unhold_lkb(lkb); /* undoes create_lkb() */ |
| 4477 | } else { |
| 4478 | _request_lock(r, lkb); |
| 4479 | |
| 4480 | if (r->res_master_nodeid == dlm_our_nodeid()) |
| 4481 | confirm_master(r, 0); |
| 4482 | } |
| 4483 | break; |
| 4484 | |
| 4485 | default: |
| 4486 | log_error(ls, "receive_request_reply %x error %d", |
| 4487 | lkb->lkb_id, result); |
| 4488 | } |
| 4489 | |
| 4490 | if ((result == 0 || result == -EINPROGRESS) && |
| 4491 | test_and_clear_bit(DLM_IFL_OVERLAP_UNLOCK_BIT, &lkb->lkb_iflags)) { |
| 4492 | log_debug(ls, "receive_request_reply %x result %d unlock", |
| 4493 | lkb->lkb_id, result); |
| 4494 | clear_bit(DLM_IFL_OVERLAP_CANCEL_BIT, &lkb->lkb_iflags); |
| 4495 | send_unlock(r, lkb); |
| 4496 | } else if ((result == -EINPROGRESS) && |
| 4497 | test_and_clear_bit(DLM_IFL_OVERLAP_CANCEL_BIT, |
| 4498 | &lkb->lkb_iflags)) { |
| 4499 | log_debug(ls, "receive_request_reply %x cancel", lkb->lkb_id); |
| 4500 | clear_bit(DLM_IFL_OVERLAP_UNLOCK_BIT, &lkb->lkb_iflags); |
| 4501 | send_cancel(r, lkb); |
| 4502 | } else { |
| 4503 | clear_bit(DLM_IFL_OVERLAP_CANCEL_BIT, &lkb->lkb_iflags); |
| 4504 | clear_bit(DLM_IFL_OVERLAP_UNLOCK_BIT, &lkb->lkb_iflags); |
| 4505 | } |
| 4506 | out: |
| 4507 | unlock_rsb(r); |
| 4508 | put_rsb(r); |
| 4509 | dlm_put_lkb(lkb); |
| 4510 | return 0; |
| 4511 | } |
| 4512 | |
| 4513 | static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, |
| 4514 | const struct dlm_message *ms, bool local) |
| 4515 | { |
| 4516 | /* this is the value returned from do_convert() on the master */ |
| 4517 | switch (from_dlm_errno(le32_to_cpu(ms->m_result))) { |
| 4518 | case -EAGAIN: |
| 4519 | /* convert would block (be queued) on remote master */ |
| 4520 | queue_cast(r, lkb, -EAGAIN); |
| 4521 | break; |
| 4522 | |
| 4523 | case -EDEADLK: |
| 4524 | receive_flags_reply(lkb, ms, local); |
| 4525 | revert_lock_pc(r, lkb); |
| 4526 | queue_cast(r, lkb, -EDEADLK); |
| 4527 | break; |
| 4528 | |
| 4529 | case -EINPROGRESS: |
| 4530 | /* convert was queued on remote master */ |
| 4531 | receive_flags_reply(lkb, ms, local); |
| 4532 | if (is_demoted(lkb)) |
| 4533 | munge_demoted(lkb); |
| 4534 | del_lkb(r, lkb); |
| 4535 | add_lkb(r, lkb, DLM_LKSTS_CONVERT); |
| 4536 | break; |
| 4537 | |
| 4538 | case 0: |
| 4539 | /* convert was granted on remote master */ |
| 4540 | receive_flags_reply(lkb, ms, local); |
| 4541 | if (is_demoted(lkb)) |
| 4542 | munge_demoted(lkb); |
| 4543 | grant_lock_pc(r, lkb, ms); |
| 4544 | queue_cast(r, lkb, 0); |
| 4545 | break; |
| 4546 | |
| 4547 | default: |
| 4548 | log_error(r->res_ls, "receive_convert_reply %x remote %d %x %d", |
| 4549 | lkb->lkb_id, le32_to_cpu(ms->m_header.h_nodeid), |
| 4550 | le32_to_cpu(ms->m_lkid), |
| 4551 | from_dlm_errno(le32_to_cpu(ms->m_result))); |
| 4552 | dlm_print_rsb(r); |
| 4553 | dlm_print_lkb(lkb); |
| 4554 | } |
| 4555 | } |
| 4556 | |
| 4557 | static void _receive_convert_reply(struct dlm_lkb *lkb, |
| 4558 | const struct dlm_message *ms, bool local) |
| 4559 | { |
| 4560 | struct dlm_rsb *r = lkb->lkb_resource; |
| 4561 | int error; |
| 4562 | |
| 4563 | hold_rsb(r); |
| 4564 | lock_rsb(r); |
| 4565 | |
| 4566 | error = validate_message(lkb, ms); |
| 4567 | if (error) |
| 4568 | goto out; |
| 4569 | |
| 4570 | error = remove_from_waiters_ms(lkb, ms, local); |
| 4571 | if (error) |
| 4572 | goto out; |
| 4573 | |
| 4574 | __receive_convert_reply(r, lkb, ms, local); |
| 4575 | out: |
| 4576 | unlock_rsb(r); |
| 4577 | put_rsb(r); |
| 4578 | } |
| 4579 | |
| 4580 | static int receive_convert_reply(struct dlm_ls *ls, |
| 4581 | const struct dlm_message *ms) |
| 4582 | { |
| 4583 | struct dlm_lkb *lkb; |
| 4584 | int error; |
| 4585 | |
| 4586 | error = find_lkb(ls, le32_to_cpu(ms->m_remid), &lkb); |
| 4587 | if (error) |
| 4588 | return error; |
| 4589 | |
| 4590 | _receive_convert_reply(lkb, ms, false); |
| 4591 | dlm_put_lkb(lkb); |
| 4592 | return 0; |
| 4593 | } |
| 4594 | |
| 4595 | static void _receive_unlock_reply(struct dlm_lkb *lkb, |
| 4596 | const struct dlm_message *ms, bool local) |
| 4597 | { |
| 4598 | struct dlm_rsb *r = lkb->lkb_resource; |
| 4599 | int error; |
| 4600 | |
| 4601 | hold_rsb(r); |
| 4602 | lock_rsb(r); |
| 4603 | |
| 4604 | error = validate_message(lkb, ms); |
| 4605 | if (error) |
| 4606 | goto out; |
| 4607 | |
| 4608 | error = remove_from_waiters_ms(lkb, ms, local); |
| 4609 | if (error) |
| 4610 | goto out; |
| 4611 | |
| 4612 | /* this is the value returned from do_unlock() on the master */ |
| 4613 | |
| 4614 | switch (from_dlm_errno(le32_to_cpu(ms->m_result))) { |
| 4615 | case -DLM_EUNLOCK: |
| 4616 | receive_flags_reply(lkb, ms, local); |
| 4617 | remove_lock_pc(r, lkb); |
| 4618 | queue_cast(r, lkb, -DLM_EUNLOCK); |
| 4619 | break; |
| 4620 | case -ENOENT: |
| 4621 | break; |
| 4622 | default: |
| 4623 | log_error(r->res_ls, "receive_unlock_reply %x error %d", |
| 4624 | lkb->lkb_id, from_dlm_errno(le32_to_cpu(ms->m_result))); |
| 4625 | } |
| 4626 | out: |
| 4627 | unlock_rsb(r); |
| 4628 | put_rsb(r); |
| 4629 | } |
| 4630 | |
| 4631 | static int receive_unlock_reply(struct dlm_ls *ls, |
| 4632 | const struct dlm_message *ms) |
| 4633 | { |
| 4634 | struct dlm_lkb *lkb; |
| 4635 | int error; |
| 4636 | |
| 4637 | error = find_lkb(ls, le32_to_cpu(ms->m_remid), &lkb); |
| 4638 | if (error) |
| 4639 | return error; |
| 4640 | |
| 4641 | _receive_unlock_reply(lkb, ms, false); |
| 4642 | dlm_put_lkb(lkb); |
| 4643 | return 0; |
| 4644 | } |
| 4645 | |
| 4646 | static void _receive_cancel_reply(struct dlm_lkb *lkb, |
| 4647 | const struct dlm_message *ms, bool local) |
| 4648 | { |
| 4649 | struct dlm_rsb *r = lkb->lkb_resource; |
| 4650 | int error; |
| 4651 | |
| 4652 | hold_rsb(r); |
| 4653 | lock_rsb(r); |
| 4654 | |
| 4655 | error = validate_message(lkb, ms); |
| 4656 | if (error) |
| 4657 | goto out; |
| 4658 | |
| 4659 | error = remove_from_waiters_ms(lkb, ms, local); |
| 4660 | if (error) |
| 4661 | goto out; |
| 4662 | |
| 4663 | /* this is the value returned from do_cancel() on the master */ |
| 4664 | |
| 4665 | switch (from_dlm_errno(le32_to_cpu(ms->m_result))) { |
| 4666 | case -DLM_ECANCEL: |
| 4667 | receive_flags_reply(lkb, ms, local); |
| 4668 | revert_lock_pc(r, lkb); |
| 4669 | queue_cast(r, lkb, -DLM_ECANCEL); |
| 4670 | break; |
| 4671 | case 0: |
| 4672 | break; |
| 4673 | default: |
| 4674 | log_error(r->res_ls, "receive_cancel_reply %x error %d", |
| 4675 | lkb->lkb_id, |
| 4676 | from_dlm_errno(le32_to_cpu(ms->m_result))); |
| 4677 | } |
| 4678 | out: |
| 4679 | unlock_rsb(r); |
| 4680 | put_rsb(r); |
| 4681 | } |
| 4682 | |
| 4683 | static int receive_cancel_reply(struct dlm_ls *ls, |
| 4684 | const struct dlm_message *ms) |
| 4685 | { |
| 4686 | struct dlm_lkb *lkb; |
| 4687 | int error; |
| 4688 | |
| 4689 | error = find_lkb(ls, le32_to_cpu(ms->m_remid), &lkb); |
| 4690 | if (error) |
| 4691 | return error; |
| 4692 | |
| 4693 | _receive_cancel_reply(lkb, ms, false); |
| 4694 | dlm_put_lkb(lkb); |
| 4695 | return 0; |
| 4696 | } |
| 4697 | |
| 4698 | static void receive_lookup_reply(struct dlm_ls *ls, |
| 4699 | const struct dlm_message *ms) |
| 4700 | { |
| 4701 | struct dlm_lkb *lkb; |
| 4702 | struct dlm_rsb *r; |
| 4703 | int error, ret_nodeid; |
| 4704 | int do_lookup_list = 0; |
| 4705 | |
| 4706 | error = find_lkb(ls, le32_to_cpu(ms->m_lkid), &lkb); |
| 4707 | if (error) { |
| 4708 | log_error(ls, "%s no lkid %x", __func__, |
| 4709 | le32_to_cpu(ms->m_lkid)); |
| 4710 | return; |
| 4711 | } |
| 4712 | |
| 4713 | /* ms->m_result is the value returned by dlm_master_lookup on dir node |
| 4714 | FIXME: will a non-zero error ever be returned? */ |
| 4715 | |
| 4716 | r = lkb->lkb_resource; |
| 4717 | hold_rsb(r); |
| 4718 | lock_rsb(r); |
| 4719 | |
| 4720 | error = remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY); |
| 4721 | if (error) |
| 4722 | goto out; |
| 4723 | |
| 4724 | ret_nodeid = le32_to_cpu(ms->m_nodeid); |
| 4725 | |
| 4726 | /* We sometimes receive a request from the dir node for this |
| 4727 | rsb before we've received the dir node's loookup_reply for it. |
| 4728 | The request from the dir node implies we're the master, so we set |
| 4729 | ourself as master in receive_request_reply, and verify here that |
| 4730 | we are indeed the master. */ |
| 4731 | |
| 4732 | if (r->res_master_nodeid && (r->res_master_nodeid != ret_nodeid)) { |
| 4733 | /* This should never happen */ |
| 4734 | log_error(ls, "receive_lookup_reply %x from %d ret %d " |
| 4735 | "master %d dir %d our %d first %x %s", |
| 4736 | lkb->lkb_id, le32_to_cpu(ms->m_header.h_nodeid), |
| 4737 | ret_nodeid, r->res_master_nodeid, r->res_dir_nodeid, |
| 4738 | dlm_our_nodeid(), r->res_first_lkid, r->res_name); |
| 4739 | } |
| 4740 | |
| 4741 | if (ret_nodeid == dlm_our_nodeid()) { |
| 4742 | r->res_master_nodeid = ret_nodeid; |
| 4743 | r->res_nodeid = 0; |
| 4744 | do_lookup_list = 1; |
| 4745 | r->res_first_lkid = 0; |
| 4746 | } else if (ret_nodeid == -1) { |
| 4747 | /* the remote node doesn't believe it's the dir node */ |
| 4748 | log_error(ls, "receive_lookup_reply %x from %d bad ret_nodeid", |
| 4749 | lkb->lkb_id, le32_to_cpu(ms->m_header.h_nodeid)); |
| 4750 | r->res_master_nodeid = 0; |
| 4751 | r->res_nodeid = -1; |
| 4752 | lkb->lkb_nodeid = -1; |
| 4753 | } else { |
| 4754 | /* set_master() will set lkb_nodeid from r */ |
| 4755 | r->res_master_nodeid = ret_nodeid; |
| 4756 | r->res_nodeid = ret_nodeid; |
| 4757 | } |
| 4758 | |
| 4759 | if (is_overlap(lkb)) { |
| 4760 | log_debug(ls, "receive_lookup_reply %x unlock %x", |
| 4761 | lkb->lkb_id, dlm_iflags_val(lkb)); |
| 4762 | queue_cast_overlap(r, lkb); |
| 4763 | unhold_lkb(lkb); /* undoes create_lkb() */ |
| 4764 | goto out_list; |
| 4765 | } |
| 4766 | |
| 4767 | _request_lock(r, lkb); |
| 4768 | |
| 4769 | out_list: |
| 4770 | if (do_lookup_list) |
| 4771 | process_lookup_list(r); |
| 4772 | out: |
| 4773 | unlock_rsb(r); |
| 4774 | put_rsb(r); |
| 4775 | dlm_put_lkb(lkb); |
| 4776 | } |
| 4777 | |
| 4778 | static void _receive_message(struct dlm_ls *ls, const struct dlm_message *ms, |
| 4779 | uint32_t saved_seq) |
| 4780 | { |
| 4781 | int error = 0, noent = 0; |
| 4782 | |
| 4783 | if (WARN_ON_ONCE(!dlm_is_member(ls, le32_to_cpu(ms->m_header.h_nodeid)))) { |
| 4784 | log_limit(ls, "receive %d from non-member %d %x %x %d", |
| 4785 | le32_to_cpu(ms->m_type), |
| 4786 | le32_to_cpu(ms->m_header.h_nodeid), |
| 4787 | le32_to_cpu(ms->m_lkid), le32_to_cpu(ms->m_remid), |
| 4788 | from_dlm_errno(le32_to_cpu(ms->m_result))); |
| 4789 | return; |
| 4790 | } |
| 4791 | |
| 4792 | switch (ms->m_type) { |
| 4793 | |
| 4794 | /* messages sent to a master node */ |
| 4795 | |
| 4796 | case cpu_to_le32(DLM_MSG_REQUEST): |
| 4797 | error = receive_request(ls, ms); |
| 4798 | break; |
| 4799 | |
| 4800 | case cpu_to_le32(DLM_MSG_CONVERT): |
| 4801 | error = receive_convert(ls, ms); |
| 4802 | break; |
| 4803 | |
| 4804 | case cpu_to_le32(DLM_MSG_UNLOCK): |
| 4805 | error = receive_unlock(ls, ms); |
| 4806 | break; |
| 4807 | |
| 4808 | case cpu_to_le32(DLM_MSG_CANCEL): |
| 4809 | noent = 1; |
| 4810 | error = receive_cancel(ls, ms); |
| 4811 | break; |
| 4812 | |
| 4813 | /* messages sent from a master node (replies to above) */ |
| 4814 | |
| 4815 | case cpu_to_le32(DLM_MSG_REQUEST_REPLY): |
| 4816 | error = receive_request_reply(ls, ms); |
| 4817 | break; |
| 4818 | |
| 4819 | case cpu_to_le32(DLM_MSG_CONVERT_REPLY): |
| 4820 | error = receive_convert_reply(ls, ms); |
| 4821 | break; |
| 4822 | |
| 4823 | case cpu_to_le32(DLM_MSG_UNLOCK_REPLY): |
| 4824 | error = receive_unlock_reply(ls, ms); |
| 4825 | break; |
| 4826 | |
| 4827 | case cpu_to_le32(DLM_MSG_CANCEL_REPLY): |
| 4828 | error = receive_cancel_reply(ls, ms); |
| 4829 | break; |
| 4830 | |
| 4831 | /* messages sent from a master node (only two types of async msg) */ |
| 4832 | |
| 4833 | case cpu_to_le32(DLM_MSG_GRANT): |
| 4834 | noent = 1; |
| 4835 | error = receive_grant(ls, ms); |
| 4836 | break; |
| 4837 | |
| 4838 | case cpu_to_le32(DLM_MSG_BAST): |
| 4839 | noent = 1; |
| 4840 | error = receive_bast(ls, ms); |
| 4841 | break; |
| 4842 | |
| 4843 | /* messages sent to a dir node */ |
| 4844 | |
| 4845 | case cpu_to_le32(DLM_MSG_LOOKUP): |
| 4846 | receive_lookup(ls, ms); |
| 4847 | break; |
| 4848 | |
| 4849 | case cpu_to_le32(DLM_MSG_REMOVE): |
| 4850 | receive_remove(ls, ms); |
| 4851 | break; |
| 4852 | |
| 4853 | /* messages sent from a dir node (remove has no reply) */ |
| 4854 | |
| 4855 | case cpu_to_le32(DLM_MSG_LOOKUP_REPLY): |
| 4856 | receive_lookup_reply(ls, ms); |
| 4857 | break; |
| 4858 | |
| 4859 | /* other messages */ |
| 4860 | |
| 4861 | case cpu_to_le32(DLM_MSG_PURGE): |
| 4862 | receive_purge(ls, ms); |
| 4863 | break; |
| 4864 | |
| 4865 | default: |
| 4866 | log_error(ls, "unknown message type %d", |
| 4867 | le32_to_cpu(ms->m_type)); |
| 4868 | } |
| 4869 | |
| 4870 | /* |
| 4871 | * When checking for ENOENT, we're checking the result of |
| 4872 | * find_lkb(m_remid): |
| 4873 | * |
| 4874 | * The lock id referenced in the message wasn't found. This may |
| 4875 | * happen in normal usage for the async messages and cancel, so |
| 4876 | * only use log_debug for them. |
| 4877 | * |
| 4878 | * Some errors are expected and normal. |
| 4879 | */ |
| 4880 | |
| 4881 | if (error == -ENOENT && noent) { |
| 4882 | log_debug(ls, "receive %d no %x remote %d %x saved_seq %u", |
| 4883 | le32_to_cpu(ms->m_type), le32_to_cpu(ms->m_remid), |
| 4884 | le32_to_cpu(ms->m_header.h_nodeid), |
| 4885 | le32_to_cpu(ms->m_lkid), saved_seq); |
| 4886 | } else if (error == -ENOENT) { |
| 4887 | log_error(ls, "receive %d no %x remote %d %x saved_seq %u", |
| 4888 | le32_to_cpu(ms->m_type), le32_to_cpu(ms->m_remid), |
| 4889 | le32_to_cpu(ms->m_header.h_nodeid), |
| 4890 | le32_to_cpu(ms->m_lkid), saved_seq); |
| 4891 | |
| 4892 | if (ms->m_type == cpu_to_le32(DLM_MSG_CONVERT)) |
| 4893 | dlm_dump_rsb_hash(ls, le32_to_cpu(ms->m_hash)); |
| 4894 | } |
| 4895 | |
| 4896 | if (error == -EINVAL) { |
| 4897 | log_error(ls, "receive %d inval from %d lkid %x remid %x " |
| 4898 | "saved_seq %u", |
| 4899 | le32_to_cpu(ms->m_type), |
| 4900 | le32_to_cpu(ms->m_header.h_nodeid), |
| 4901 | le32_to_cpu(ms->m_lkid), le32_to_cpu(ms->m_remid), |
| 4902 | saved_seq); |
| 4903 | } |
| 4904 | } |
| 4905 | |
| 4906 | /* If the lockspace is in recovery mode (locking stopped), then normal |
| 4907 | messages are saved on the requestqueue for processing after recovery is |
| 4908 | done. When not in recovery mode, we wait for dlm_recoverd to drain saved |
| 4909 | messages off the requestqueue before we process new ones. This occurs right |
| 4910 | after recovery completes when we transition from saving all messages on |
| 4911 | requestqueue, to processing all the saved messages, to processing new |
| 4912 | messages as they arrive. */ |
| 4913 | |
| 4914 | static void dlm_receive_message(struct dlm_ls *ls, const struct dlm_message *ms, |
| 4915 | int nodeid) |
| 4916 | { |
| 4917 | try_again: |
| 4918 | read_lock_bh(&ls->ls_requestqueue_lock); |
| 4919 | if (test_bit(LSFL_RECV_MSG_BLOCKED, &ls->ls_flags)) { |
| 4920 | /* If we were a member of this lockspace, left, and rejoined, |
| 4921 | other nodes may still be sending us messages from the |
| 4922 | lockspace generation before we left. */ |
| 4923 | if (WARN_ON_ONCE(!ls->ls_generation)) { |
| 4924 | read_unlock_bh(&ls->ls_requestqueue_lock); |
| 4925 | log_limit(ls, "receive %d from %d ignore old gen", |
| 4926 | le32_to_cpu(ms->m_type), nodeid); |
| 4927 | return; |
| 4928 | } |
| 4929 | |
| 4930 | read_unlock_bh(&ls->ls_requestqueue_lock); |
| 4931 | write_lock_bh(&ls->ls_requestqueue_lock); |
| 4932 | /* recheck because we hold writelock now */ |
| 4933 | if (!test_bit(LSFL_RECV_MSG_BLOCKED, &ls->ls_flags)) { |
| 4934 | write_unlock_bh(&ls->ls_requestqueue_lock); |
| 4935 | goto try_again; |
| 4936 | } |
| 4937 | |
| 4938 | dlm_add_requestqueue(ls, nodeid, ms); |
| 4939 | write_unlock_bh(&ls->ls_requestqueue_lock); |
| 4940 | } else { |
| 4941 | _receive_message(ls, ms, 0); |
| 4942 | read_unlock_bh(&ls->ls_requestqueue_lock); |
| 4943 | } |
| 4944 | } |
| 4945 | |
| 4946 | /* This is called by dlm_recoverd to process messages that were saved on |
| 4947 | the requestqueue. */ |
| 4948 | |
| 4949 | void dlm_receive_message_saved(struct dlm_ls *ls, const struct dlm_message *ms, |
| 4950 | uint32_t saved_seq) |
| 4951 | { |
| 4952 | _receive_message(ls, ms, saved_seq); |
| 4953 | } |
| 4954 | |
| 4955 | /* This is called by the midcomms layer when something is received for |
| 4956 | the lockspace. It could be either a MSG (normal message sent as part of |
| 4957 | standard locking activity) or an RCOM (recovery message sent as part of |
| 4958 | lockspace recovery). */ |
| 4959 | |
| 4960 | void dlm_receive_buffer(const union dlm_packet *p, int nodeid) |
| 4961 | { |
| 4962 | const struct dlm_header *hd = &p->header; |
| 4963 | struct dlm_ls *ls; |
| 4964 | int type = 0; |
| 4965 | |
| 4966 | switch (hd->h_cmd) { |
| 4967 | case DLM_MSG: |
| 4968 | type = le32_to_cpu(p->message.m_type); |
| 4969 | break; |
| 4970 | case DLM_RCOM: |
| 4971 | type = le32_to_cpu(p->rcom.rc_type); |
| 4972 | break; |
| 4973 | default: |
| 4974 | log_print("invalid h_cmd %d from %u", hd->h_cmd, nodeid); |
| 4975 | return; |
| 4976 | } |
| 4977 | |
| 4978 | if (le32_to_cpu(hd->h_nodeid) != nodeid) { |
| 4979 | log_print("invalid h_nodeid %d from %d lockspace %x", |
| 4980 | le32_to_cpu(hd->h_nodeid), nodeid, |
| 4981 | le32_to_cpu(hd->u.h_lockspace)); |
| 4982 | return; |
| 4983 | } |
| 4984 | |
| 4985 | ls = dlm_find_lockspace_global(le32_to_cpu(hd->u.h_lockspace)); |
| 4986 | if (!ls) { |
| 4987 | if (dlm_config.ci_log_debug) { |
| 4988 | printk_ratelimited(KERN_DEBUG "dlm: invalid lockspace " |
| 4989 | "%u from %d cmd %d type %d\n", |
| 4990 | le32_to_cpu(hd->u.h_lockspace), nodeid, |
| 4991 | hd->h_cmd, type); |
| 4992 | } |
| 4993 | |
| 4994 | if (hd->h_cmd == DLM_RCOM && type == DLM_RCOM_STATUS) |
| 4995 | dlm_send_ls_not_ready(nodeid, &p->rcom); |
| 4996 | return; |
| 4997 | } |
| 4998 | |
| 4999 | /* this rwsem allows dlm_ls_stop() to wait for all dlm_recv threads to |
| 5000 | be inactive (in this ls) before transitioning to recovery mode */ |
| 5001 | |
| 5002 | read_lock_bh(&ls->ls_recv_active); |
| 5003 | if (hd->h_cmd == DLM_MSG) |
| 5004 | dlm_receive_message(ls, &p->message, nodeid); |
| 5005 | else if (hd->h_cmd == DLM_RCOM) |
| 5006 | dlm_receive_rcom(ls, &p->rcom, nodeid); |
| 5007 | else |
| 5008 | log_error(ls, "invalid h_cmd %d from %d lockspace %x", |
| 5009 | hd->h_cmd, nodeid, le32_to_cpu(hd->u.h_lockspace)); |
| 5010 | read_unlock_bh(&ls->ls_recv_active); |
| 5011 | |
| 5012 | dlm_put_lockspace(ls); |
| 5013 | } |
| 5014 | |
| 5015 | static void recover_convert_waiter(struct dlm_ls *ls, struct dlm_lkb *lkb, |
| 5016 | struct dlm_message *ms_local) |
| 5017 | { |
| 5018 | if (middle_conversion(lkb)) { |
| 5019 | hold_lkb(lkb); |
| 5020 | memset(ms_local, 0, sizeof(struct dlm_message)); |
| 5021 | ms_local->m_type = cpu_to_le32(DLM_MSG_CONVERT_REPLY); |
| 5022 | ms_local->m_result = cpu_to_le32(to_dlm_errno(-EINPROGRESS)); |
| 5023 | ms_local->m_header.h_nodeid = cpu_to_le32(lkb->lkb_nodeid); |
| 5024 | _receive_convert_reply(lkb, ms_local, true); |
| 5025 | |
| 5026 | /* Same special case as in receive_rcom_lock_args() */ |
| 5027 | lkb->lkb_grmode = DLM_LOCK_IV; |
| 5028 | rsb_set_flag(lkb->lkb_resource, RSB_RECOVER_CONVERT); |
| 5029 | unhold_lkb(lkb); |
| 5030 | |
| 5031 | } else if (lkb->lkb_rqmode >= lkb->lkb_grmode) { |
| 5032 | set_bit(DLM_IFL_RESEND_BIT, &lkb->lkb_iflags); |
| 5033 | } |
| 5034 | |
| 5035 | /* lkb->lkb_rqmode < lkb->lkb_grmode shouldn't happen since down |
| 5036 | conversions are async; there's no reply from the remote master */ |
| 5037 | } |
| 5038 | |
| 5039 | /* A waiting lkb needs recovery if the master node has failed, or |
| 5040 | the master node is changing (only when no directory is used) */ |
| 5041 | |
| 5042 | static int waiter_needs_recovery(struct dlm_ls *ls, struct dlm_lkb *lkb, |
| 5043 | int dir_nodeid) |
| 5044 | { |
| 5045 | if (dlm_no_directory(ls)) |
| 5046 | return 1; |
| 5047 | |
| 5048 | if (dlm_is_removed(ls, lkb->lkb_wait_nodeid)) |
| 5049 | return 1; |
| 5050 | |
| 5051 | return 0; |
| 5052 | } |
| 5053 | |
| 5054 | /* Recovery for locks that are waiting for replies from nodes that are now |
| 5055 | gone. We can just complete unlocks and cancels by faking a reply from the |
| 5056 | dead node. Requests and up-conversions we flag to be resent after |
| 5057 | recovery. Down-conversions can just be completed with a fake reply like |
| 5058 | unlocks. Conversions between PR and CW need special attention. */ |
| 5059 | |
| 5060 | void dlm_recover_waiters_pre(struct dlm_ls *ls) |
| 5061 | { |
| 5062 | struct dlm_lkb *lkb, *safe; |
| 5063 | struct dlm_message *ms_local; |
| 5064 | int wait_type, local_unlock_result, local_cancel_result; |
| 5065 | int dir_nodeid; |
| 5066 | |
| 5067 | ms_local = kmalloc(sizeof(*ms_local), GFP_KERNEL); |
| 5068 | if (!ms_local) |
| 5069 | return; |
| 5070 | |
| 5071 | list_for_each_entry_safe(lkb, safe, &ls->ls_waiters, lkb_wait_reply) { |
| 5072 | |
| 5073 | dir_nodeid = dlm_dir_nodeid(lkb->lkb_resource); |
| 5074 | |
| 5075 | /* exclude debug messages about unlocks because there can be so |
| 5076 | many and they aren't very interesting */ |
| 5077 | |
| 5078 | if (lkb->lkb_wait_type != DLM_MSG_UNLOCK) { |
| 5079 | log_debug(ls, "waiter %x remote %x msg %d r_nodeid %d " |
| 5080 | "lkb_nodeid %d wait_nodeid %d dir_nodeid %d", |
| 5081 | lkb->lkb_id, |
| 5082 | lkb->lkb_remid, |
| 5083 | lkb->lkb_wait_type, |
| 5084 | lkb->lkb_resource->res_nodeid, |
| 5085 | lkb->lkb_nodeid, |
| 5086 | lkb->lkb_wait_nodeid, |
| 5087 | dir_nodeid); |
| 5088 | } |
| 5089 | |
| 5090 | /* all outstanding lookups, regardless of destination will be |
| 5091 | resent after recovery is done */ |
| 5092 | |
| 5093 | if (lkb->lkb_wait_type == DLM_MSG_LOOKUP) { |
| 5094 | set_bit(DLM_IFL_RESEND_BIT, &lkb->lkb_iflags); |
| 5095 | continue; |
| 5096 | } |
| 5097 | |
| 5098 | if (!waiter_needs_recovery(ls, lkb, dir_nodeid)) |
| 5099 | continue; |
| 5100 | |
| 5101 | wait_type = lkb->lkb_wait_type; |
| 5102 | local_unlock_result = -DLM_EUNLOCK; |
| 5103 | local_cancel_result = -DLM_ECANCEL; |
| 5104 | |
| 5105 | /* Main reply may have been received leaving a zero wait_type, |
| 5106 | but a reply for the overlapping op may not have been |
| 5107 | received. In that case we need to fake the appropriate |
| 5108 | reply for the overlap op. */ |
| 5109 | |
| 5110 | if (!wait_type) { |
| 5111 | if (is_overlap_cancel(lkb)) { |
| 5112 | wait_type = DLM_MSG_CANCEL; |
| 5113 | if (lkb->lkb_grmode == DLM_LOCK_IV) |
| 5114 | local_cancel_result = 0; |
| 5115 | } |
| 5116 | if (is_overlap_unlock(lkb)) { |
| 5117 | wait_type = DLM_MSG_UNLOCK; |
| 5118 | if (lkb->lkb_grmode == DLM_LOCK_IV) |
| 5119 | local_unlock_result = -ENOENT; |
| 5120 | } |
| 5121 | |
| 5122 | log_debug(ls, "rwpre overlap %x %x %d %d %d", |
| 5123 | lkb->lkb_id, dlm_iflags_val(lkb), wait_type, |
| 5124 | local_cancel_result, local_unlock_result); |
| 5125 | } |
| 5126 | |
| 5127 | switch (wait_type) { |
| 5128 | |
| 5129 | case DLM_MSG_REQUEST: |
| 5130 | set_bit(DLM_IFL_RESEND_BIT, &lkb->lkb_iflags); |
| 5131 | break; |
| 5132 | |
| 5133 | case DLM_MSG_CONVERT: |
| 5134 | recover_convert_waiter(ls, lkb, ms_local); |
| 5135 | break; |
| 5136 | |
| 5137 | case DLM_MSG_UNLOCK: |
| 5138 | hold_lkb(lkb); |
| 5139 | memset(ms_local, 0, sizeof(struct dlm_message)); |
| 5140 | ms_local->m_type = cpu_to_le32(DLM_MSG_UNLOCK_REPLY); |
| 5141 | ms_local->m_result = cpu_to_le32(to_dlm_errno(local_unlock_result)); |
| 5142 | ms_local->m_header.h_nodeid = cpu_to_le32(lkb->lkb_nodeid); |
| 5143 | _receive_unlock_reply(lkb, ms_local, true); |
| 5144 | dlm_put_lkb(lkb); |
| 5145 | break; |
| 5146 | |
| 5147 | case DLM_MSG_CANCEL: |
| 5148 | hold_lkb(lkb); |
| 5149 | memset(ms_local, 0, sizeof(struct dlm_message)); |
| 5150 | ms_local->m_type = cpu_to_le32(DLM_MSG_CANCEL_REPLY); |
| 5151 | ms_local->m_result = cpu_to_le32(to_dlm_errno(local_cancel_result)); |
| 5152 | ms_local->m_header.h_nodeid = cpu_to_le32(lkb->lkb_nodeid); |
| 5153 | _receive_cancel_reply(lkb, ms_local, true); |
| 5154 | dlm_put_lkb(lkb); |
| 5155 | break; |
| 5156 | |
| 5157 | default: |
| 5158 | log_error(ls, "invalid lkb wait_type %d %d", |
| 5159 | lkb->lkb_wait_type, wait_type); |
| 5160 | } |
| 5161 | schedule(); |
| 5162 | } |
| 5163 | kfree(ms_local); |
| 5164 | } |
| 5165 | |
| 5166 | static struct dlm_lkb *find_resend_waiter(struct dlm_ls *ls) |
| 5167 | { |
| 5168 | struct dlm_lkb *lkb = NULL, *iter; |
| 5169 | |
| 5170 | spin_lock_bh(&ls->ls_waiters_lock); |
| 5171 | list_for_each_entry(iter, &ls->ls_waiters, lkb_wait_reply) { |
| 5172 | if (test_bit(DLM_IFL_RESEND_BIT, &iter->lkb_iflags)) { |
| 5173 | hold_lkb(iter); |
| 5174 | lkb = iter; |
| 5175 | break; |
| 5176 | } |
| 5177 | } |
| 5178 | spin_unlock_bh(&ls->ls_waiters_lock); |
| 5179 | |
| 5180 | return lkb; |
| 5181 | } |
| 5182 | |
| 5183 | /* |
| 5184 | * Forced state reset for locks that were in the middle of remote operations |
| 5185 | * when recovery happened (i.e. lkbs that were on the waiters list, waiting |
| 5186 | * for a reply from a remote operation.) The lkbs remaining on the waiters |
| 5187 | * list need to be reevaluated; some may need resending to a different node |
| 5188 | * than previously, and some may now need local handling rather than remote. |
| 5189 | * |
| 5190 | * First, the lkb state for the voided remote operation is forcibly reset, |
| 5191 | * equivalent to what remove_from_waiters() would normally do: |
| 5192 | * . lkb removed from ls_waiters list |
| 5193 | * . lkb wait_type cleared |
| 5194 | * . lkb waiters_count cleared |
| 5195 | * . lkb ref count decremented for each waiters_count (almost always 1, |
| 5196 | * but possibly 2 in case of cancel/unlock overlapping, which means |
| 5197 | * two remote replies were being expected for the lkb.) |
| 5198 | * |
| 5199 | * Second, the lkb is reprocessed like an original operation would be, |
| 5200 | * by passing it to _request_lock or _convert_lock, which will either |
| 5201 | * process the lkb operation locally, or send it to a remote node again |
| 5202 | * and put the lkb back onto the waiters list. |
| 5203 | * |
| 5204 | * When reprocessing the lkb, we may find that it's flagged for an overlapping |
| 5205 | * force-unlock or cancel, either from before recovery began, or after recovery |
| 5206 | * finished. If this is the case, the unlock/cancel is done directly, and the |
| 5207 | * original operation is not initiated again (no _request_lock/_convert_lock.) |
| 5208 | */ |
| 5209 | |
| 5210 | int dlm_recover_waiters_post(struct dlm_ls *ls) |
| 5211 | { |
| 5212 | struct dlm_lkb *lkb; |
| 5213 | struct dlm_rsb *r; |
| 5214 | int error = 0, mstype, err, oc, ou; |
| 5215 | |
| 5216 | while (1) { |
| 5217 | if (dlm_locking_stopped(ls)) { |
| 5218 | log_debug(ls, "recover_waiters_post aborted"); |
| 5219 | error = -EINTR; |
| 5220 | break; |
| 5221 | } |
| 5222 | |
| 5223 | /* |
| 5224 | * Find an lkb from the waiters list that's been affected by |
| 5225 | * recovery node changes, and needs to be reprocessed. Does |
| 5226 | * hold_lkb(), adding a refcount. |
| 5227 | */ |
| 5228 | lkb = find_resend_waiter(ls); |
| 5229 | if (!lkb) |
| 5230 | break; |
| 5231 | |
| 5232 | r = lkb->lkb_resource; |
| 5233 | hold_rsb(r); |
| 5234 | lock_rsb(r); |
| 5235 | |
| 5236 | /* |
| 5237 | * If the lkb has been flagged for a force unlock or cancel, |
| 5238 | * then the reprocessing below will be replaced by just doing |
| 5239 | * the unlock/cancel directly. |
| 5240 | */ |
| 5241 | mstype = lkb->lkb_wait_type; |
| 5242 | oc = test_and_clear_bit(DLM_IFL_OVERLAP_CANCEL_BIT, |
| 5243 | &lkb->lkb_iflags); |
| 5244 | ou = test_and_clear_bit(DLM_IFL_OVERLAP_UNLOCK_BIT, |
| 5245 | &lkb->lkb_iflags); |
| 5246 | err = 0; |
| 5247 | |
| 5248 | log_debug(ls, "waiter %x remote %x msg %d r_nodeid %d " |
| 5249 | "lkb_nodeid %d wait_nodeid %d dir_nodeid %d " |
| 5250 | "overlap %d %d", lkb->lkb_id, lkb->lkb_remid, mstype, |
| 5251 | r->res_nodeid, lkb->lkb_nodeid, lkb->lkb_wait_nodeid, |
| 5252 | dlm_dir_nodeid(r), oc, ou); |
| 5253 | |
| 5254 | /* |
| 5255 | * No reply to the pre-recovery operation will now be received, |
| 5256 | * so a forced equivalent of remove_from_waiters() is needed to |
| 5257 | * reset the waiters state that was in place before recovery. |
| 5258 | */ |
| 5259 | |
| 5260 | clear_bit(DLM_IFL_RESEND_BIT, &lkb->lkb_iflags); |
| 5261 | |
| 5262 | /* Forcibly clear wait_type */ |
| 5263 | lkb->lkb_wait_type = 0; |
| 5264 | |
| 5265 | /* |
| 5266 | * Forcibly reset wait_count and associated refcount. The |
| 5267 | * wait_count will almost always be 1, but in case of an |
| 5268 | * overlapping unlock/cancel it could be 2: see where |
| 5269 | * add_to_waiters() finds the lkb is already on the waiters |
| 5270 | * list and does lkb_wait_count++; hold_lkb(). |
| 5271 | */ |
| 5272 | while (lkb->lkb_wait_count) { |
| 5273 | lkb->lkb_wait_count--; |
| 5274 | unhold_lkb(lkb); |
| 5275 | } |
| 5276 | |
| 5277 | /* Forcibly remove from waiters list */ |
| 5278 | spin_lock_bh(&ls->ls_waiters_lock); |
| 5279 | list_del_init(&lkb->lkb_wait_reply); |
| 5280 | spin_unlock_bh(&ls->ls_waiters_lock); |
| 5281 | |
| 5282 | /* |
| 5283 | * The lkb is now clear of all prior waiters state and can be |
| 5284 | * processed locally, or sent to remote node again, or directly |
| 5285 | * cancelled/unlocked. |
| 5286 | */ |
| 5287 | |
| 5288 | if (oc || ou) { |
| 5289 | /* do an unlock or cancel instead of resending */ |
| 5290 | switch (mstype) { |
| 5291 | case DLM_MSG_LOOKUP: |
| 5292 | case DLM_MSG_REQUEST: |
| 5293 | queue_cast(r, lkb, ou ? -DLM_EUNLOCK : |
| 5294 | -DLM_ECANCEL); |
| 5295 | unhold_lkb(lkb); /* undoes create_lkb() */ |
| 5296 | break; |
| 5297 | case DLM_MSG_CONVERT: |
| 5298 | if (oc) { |
| 5299 | queue_cast(r, lkb, -DLM_ECANCEL); |
| 5300 | } else { |
| 5301 | lkb->lkb_exflags |= DLM_LKF_FORCEUNLOCK; |
| 5302 | _unlock_lock(r, lkb); |
| 5303 | } |
| 5304 | break; |
| 5305 | default: |
| 5306 | err = 1; |
| 5307 | } |
| 5308 | } else { |
| 5309 | switch (mstype) { |
| 5310 | case DLM_MSG_LOOKUP: |
| 5311 | case DLM_MSG_REQUEST: |
| 5312 | _request_lock(r, lkb); |
| 5313 | if (r->res_nodeid != -1 && is_master(r)) |
| 5314 | confirm_master(r, 0); |
| 5315 | break; |
| 5316 | case DLM_MSG_CONVERT: |
| 5317 | _convert_lock(r, lkb); |
| 5318 | break; |
| 5319 | default: |
| 5320 | err = 1; |
| 5321 | } |
| 5322 | } |
| 5323 | |
| 5324 | if (err) { |
| 5325 | log_error(ls, "waiter %x msg %d r_nodeid %d " |
| 5326 | "dir_nodeid %d overlap %d %d", |
| 5327 | lkb->lkb_id, mstype, r->res_nodeid, |
| 5328 | dlm_dir_nodeid(r), oc, ou); |
| 5329 | } |
| 5330 | unlock_rsb(r); |
| 5331 | put_rsb(r); |
| 5332 | dlm_put_lkb(lkb); |
| 5333 | } |
| 5334 | |
| 5335 | return error; |
| 5336 | } |
| 5337 | |
| 5338 | static void purge_mstcpy_list(struct dlm_ls *ls, struct dlm_rsb *r, |
| 5339 | struct list_head *list) |
| 5340 | { |
| 5341 | struct dlm_lkb *lkb, *safe; |
| 5342 | |
| 5343 | list_for_each_entry_safe(lkb, safe, list, lkb_statequeue) { |
| 5344 | if (!is_master_copy(lkb)) |
| 5345 | continue; |
| 5346 | |
| 5347 | /* don't purge lkbs we've added in recover_master_copy for |
| 5348 | the current recovery seq */ |
| 5349 | |
| 5350 | if (lkb->lkb_recover_seq == ls->ls_recover_seq) |
| 5351 | continue; |
| 5352 | |
| 5353 | del_lkb(r, lkb); |
| 5354 | |
| 5355 | /* this put should free the lkb */ |
| 5356 | if (!dlm_put_lkb(lkb)) |
| 5357 | log_error(ls, "purged mstcpy lkb not released"); |
| 5358 | } |
| 5359 | } |
| 5360 | |
| 5361 | void dlm_purge_mstcpy_locks(struct dlm_rsb *r) |
| 5362 | { |
| 5363 | struct dlm_ls *ls = r->res_ls; |
| 5364 | |
| 5365 | purge_mstcpy_list(ls, r, &r->res_grantqueue); |
| 5366 | purge_mstcpy_list(ls, r, &r->res_convertqueue); |
| 5367 | purge_mstcpy_list(ls, r, &r->res_waitqueue); |
| 5368 | } |
| 5369 | |
| 5370 | static void purge_dead_list(struct dlm_ls *ls, struct dlm_rsb *r, |
| 5371 | struct list_head *list, |
| 5372 | int nodeid_gone, unsigned int *count) |
| 5373 | { |
| 5374 | struct dlm_lkb *lkb, *safe; |
| 5375 | |
| 5376 | list_for_each_entry_safe(lkb, safe, list, lkb_statequeue) { |
| 5377 | if (!is_master_copy(lkb)) |
| 5378 | continue; |
| 5379 | |
| 5380 | if ((lkb->lkb_nodeid == nodeid_gone) || |
| 5381 | dlm_is_removed(ls, lkb->lkb_nodeid)) { |
| 5382 | |
| 5383 | /* tell recover_lvb to invalidate the lvb |
| 5384 | because a node holding EX/PW failed */ |
| 5385 | if ((lkb->lkb_exflags & DLM_LKF_VALBLK) && |
| 5386 | (lkb->lkb_grmode >= DLM_LOCK_PW)) { |
| 5387 | rsb_set_flag(r, RSB_RECOVER_LVB_INVAL); |
| 5388 | } |
| 5389 | |
| 5390 | del_lkb(r, lkb); |
| 5391 | |
| 5392 | /* this put should free the lkb */ |
| 5393 | if (!dlm_put_lkb(lkb)) |
| 5394 | log_error(ls, "purged dead lkb not released"); |
| 5395 | |
| 5396 | rsb_set_flag(r, RSB_RECOVER_GRANT); |
| 5397 | |
| 5398 | (*count)++; |
| 5399 | } |
| 5400 | } |
| 5401 | } |
| 5402 | |
| 5403 | /* Get rid of locks held by nodes that are gone. */ |
| 5404 | |
| 5405 | void dlm_recover_purge(struct dlm_ls *ls, const struct list_head *root_list) |
| 5406 | { |
| 5407 | struct dlm_rsb *r; |
| 5408 | struct dlm_member *memb; |
| 5409 | int nodes_count = 0; |
| 5410 | int nodeid_gone = 0; |
| 5411 | unsigned int lkb_count = 0; |
| 5412 | |
| 5413 | /* cache one removed nodeid to optimize the common |
| 5414 | case of a single node removed */ |
| 5415 | |
| 5416 | list_for_each_entry(memb, &ls->ls_nodes_gone, list) { |
| 5417 | nodes_count++; |
| 5418 | nodeid_gone = memb->nodeid; |
| 5419 | } |
| 5420 | |
| 5421 | if (!nodes_count) |
| 5422 | return; |
| 5423 | |
| 5424 | list_for_each_entry(r, root_list, res_root_list) { |
| 5425 | lock_rsb(r); |
| 5426 | if (r->res_nodeid != -1 && is_master(r)) { |
| 5427 | purge_dead_list(ls, r, &r->res_grantqueue, |
| 5428 | nodeid_gone, &lkb_count); |
| 5429 | purge_dead_list(ls, r, &r->res_convertqueue, |
| 5430 | nodeid_gone, &lkb_count); |
| 5431 | purge_dead_list(ls, r, &r->res_waitqueue, |
| 5432 | nodeid_gone, &lkb_count); |
| 5433 | } |
| 5434 | unlock_rsb(r); |
| 5435 | |
| 5436 | cond_resched(); |
| 5437 | } |
| 5438 | |
| 5439 | if (lkb_count) |
| 5440 | log_rinfo(ls, "dlm_recover_purge %u locks for %u nodes", |
| 5441 | lkb_count, nodes_count); |
| 5442 | } |
| 5443 | |
| 5444 | static struct dlm_rsb *find_grant_rsb(struct dlm_ls *ls) |
| 5445 | { |
| 5446 | struct dlm_rsb *r; |
| 5447 | |
| 5448 | read_lock_bh(&ls->ls_rsbtbl_lock); |
| 5449 | list_for_each_entry(r, &ls->ls_slow_active, res_slow_list) { |
| 5450 | if (!rsb_flag(r, RSB_RECOVER_GRANT)) |
| 5451 | continue; |
| 5452 | if (!is_master(r)) { |
| 5453 | rsb_clear_flag(r, RSB_RECOVER_GRANT); |
| 5454 | continue; |
| 5455 | } |
| 5456 | hold_rsb(r); |
| 5457 | read_unlock_bh(&ls->ls_rsbtbl_lock); |
| 5458 | return r; |
| 5459 | } |
| 5460 | read_unlock_bh(&ls->ls_rsbtbl_lock); |
| 5461 | return NULL; |
| 5462 | } |
| 5463 | |
| 5464 | /* |
| 5465 | * Attempt to grant locks on resources that we are the master of. |
| 5466 | * Locks may have become grantable during recovery because locks |
| 5467 | * from departed nodes have been purged (or not rebuilt), allowing |
| 5468 | * previously blocked locks to now be granted. The subset of rsb's |
| 5469 | * we are interested in are those with lkb's on either the convert or |
| 5470 | * waiting queues. |
| 5471 | * |
| 5472 | * Simplest would be to go through each master rsb and check for non-empty |
| 5473 | * convert or waiting queues, and attempt to grant on those rsbs. |
| 5474 | * Checking the queues requires lock_rsb, though, for which we'd need |
| 5475 | * to release the rsbtbl lock. This would make iterating through all |
| 5476 | * rsb's very inefficient. So, we rely on earlier recovery routines |
| 5477 | * to set RECOVER_GRANT on any rsb's that we should attempt to grant |
| 5478 | * locks for. |
| 5479 | */ |
| 5480 | |
| 5481 | void dlm_recover_grant(struct dlm_ls *ls) |
| 5482 | { |
| 5483 | struct dlm_rsb *r; |
| 5484 | unsigned int count = 0; |
| 5485 | unsigned int rsb_count = 0; |
| 5486 | unsigned int lkb_count = 0; |
| 5487 | |
| 5488 | while (1) { |
| 5489 | r = find_grant_rsb(ls); |
| 5490 | if (!r) |
| 5491 | break; |
| 5492 | |
| 5493 | rsb_count++; |
| 5494 | count = 0; |
| 5495 | lock_rsb(r); |
| 5496 | /* the RECOVER_GRANT flag is checked in the grant path */ |
| 5497 | grant_pending_locks(r, &count); |
| 5498 | rsb_clear_flag(r, RSB_RECOVER_GRANT); |
| 5499 | lkb_count += count; |
| 5500 | confirm_master(r, 0); |
| 5501 | unlock_rsb(r); |
| 5502 | put_rsb(r); |
| 5503 | cond_resched(); |
| 5504 | } |
| 5505 | |
| 5506 | if (lkb_count) |
| 5507 | log_rinfo(ls, "dlm_recover_grant %u locks on %u resources", |
| 5508 | lkb_count, rsb_count); |
| 5509 | } |
| 5510 | |
| 5511 | static struct dlm_lkb *search_remid_list(struct list_head *head, int nodeid, |
| 5512 | uint32_t remid) |
| 5513 | { |
| 5514 | struct dlm_lkb *lkb; |
| 5515 | |
| 5516 | list_for_each_entry(lkb, head, lkb_statequeue) { |
| 5517 | if (lkb->lkb_nodeid == nodeid && lkb->lkb_remid == remid) |
| 5518 | return lkb; |
| 5519 | } |
| 5520 | return NULL; |
| 5521 | } |
| 5522 | |
| 5523 | static struct dlm_lkb *search_remid(struct dlm_rsb *r, int nodeid, |
| 5524 | uint32_t remid) |
| 5525 | { |
| 5526 | struct dlm_lkb *lkb; |
| 5527 | |
| 5528 | lkb = search_remid_list(&r->res_grantqueue, nodeid, remid); |
| 5529 | if (lkb) |
| 5530 | return lkb; |
| 5531 | lkb = search_remid_list(&r->res_convertqueue, nodeid, remid); |
| 5532 | if (lkb) |
| 5533 | return lkb; |
| 5534 | lkb = search_remid_list(&r->res_waitqueue, nodeid, remid); |
| 5535 | if (lkb) |
| 5536 | return lkb; |
| 5537 | return NULL; |
| 5538 | } |
| 5539 | |
| 5540 | /* needs at least dlm_rcom + rcom_lock */ |
| 5541 | static int receive_rcom_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb, |
| 5542 | struct dlm_rsb *r, const struct dlm_rcom *rc) |
| 5543 | { |
| 5544 | struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf; |
| 5545 | |
| 5546 | lkb->lkb_nodeid = le32_to_cpu(rc->rc_header.h_nodeid); |
| 5547 | lkb->lkb_ownpid = le32_to_cpu(rl->rl_ownpid); |
| 5548 | lkb->lkb_remid = le32_to_cpu(rl->rl_lkid); |
| 5549 | lkb->lkb_exflags = le32_to_cpu(rl->rl_exflags); |
| 5550 | dlm_set_dflags_val(lkb, le32_to_cpu(rl->rl_flags)); |
| 5551 | set_bit(DLM_IFL_MSTCPY_BIT, &lkb->lkb_iflags); |
| 5552 | lkb->lkb_lvbseq = le32_to_cpu(rl->rl_lvbseq); |
| 5553 | lkb->lkb_rqmode = rl->rl_rqmode; |
| 5554 | lkb->lkb_grmode = rl->rl_grmode; |
| 5555 | /* don't set lkb_status because add_lkb wants to itself */ |
| 5556 | |
| 5557 | lkb->lkb_bastfn = (rl->rl_asts & DLM_CB_BAST) ? &fake_bastfn : NULL; |
| 5558 | lkb->lkb_astfn = (rl->rl_asts & DLM_CB_CAST) ? &fake_astfn : NULL; |
| 5559 | |
| 5560 | if (lkb->lkb_exflags & DLM_LKF_VALBLK) { |
| 5561 | int lvblen = le16_to_cpu(rc->rc_header.h_length) - |
| 5562 | sizeof(struct dlm_rcom) - sizeof(struct rcom_lock); |
| 5563 | if (lvblen > ls->ls_lvblen) |
| 5564 | return -EINVAL; |
| 5565 | lkb->lkb_lvbptr = dlm_allocate_lvb(ls); |
| 5566 | if (!lkb->lkb_lvbptr) |
| 5567 | return -ENOMEM; |
| 5568 | memcpy(lkb->lkb_lvbptr, rl->rl_lvb, lvblen); |
| 5569 | } |
| 5570 | |
| 5571 | /* Conversions between PR and CW (middle modes) need special handling. |
| 5572 | The real granted mode of these converting locks cannot be determined |
| 5573 | until all locks have been rebuilt on the rsb (recover_conversion) */ |
| 5574 | |
| 5575 | if (rl->rl_wait_type == cpu_to_le16(DLM_MSG_CONVERT) && |
| 5576 | middle_conversion(lkb)) { |
| 5577 | rl->rl_status = DLM_LKSTS_CONVERT; |
| 5578 | lkb->lkb_grmode = DLM_LOCK_IV; |
| 5579 | rsb_set_flag(r, RSB_RECOVER_CONVERT); |
| 5580 | } |
| 5581 | |
| 5582 | return 0; |
| 5583 | } |
| 5584 | |
| 5585 | /* This lkb may have been recovered in a previous aborted recovery so we need |
| 5586 | to check if the rsb already has an lkb with the given remote nodeid/lkid. |
| 5587 | If so we just send back a standard reply. If not, we create a new lkb with |
| 5588 | the given values and send back our lkid. We send back our lkid by sending |
| 5589 | back the rcom_lock struct we got but with the remid field filled in. */ |
| 5590 | |
| 5591 | /* needs at least dlm_rcom + rcom_lock */ |
| 5592 | int dlm_recover_master_copy(struct dlm_ls *ls, const struct dlm_rcom *rc, |
| 5593 | __le32 *rl_remid, __le32 *rl_result) |
| 5594 | { |
| 5595 | struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf; |
| 5596 | struct dlm_rsb *r; |
| 5597 | struct dlm_lkb *lkb; |
| 5598 | uint32_t remid = 0; |
| 5599 | int from_nodeid = le32_to_cpu(rc->rc_header.h_nodeid); |
| 5600 | int error; |
| 5601 | |
| 5602 | /* init rl_remid with rcom lock rl_remid */ |
| 5603 | *rl_remid = rl->rl_remid; |
| 5604 | |
| 5605 | if (rl->rl_parent_lkid) { |
| 5606 | error = -EOPNOTSUPP; |
| 5607 | goto out; |
| 5608 | } |
| 5609 | |
| 5610 | remid = le32_to_cpu(rl->rl_lkid); |
| 5611 | |
| 5612 | /* In general we expect the rsb returned to be R_MASTER, but we don't |
| 5613 | have to require it. Recovery of masters on one node can overlap |
| 5614 | recovery of locks on another node, so one node can send us MSTCPY |
| 5615 | locks before we've made ourselves master of this rsb. We can still |
| 5616 | add new MSTCPY locks that we receive here without any harm; when |
| 5617 | we make ourselves master, dlm_recover_masters() won't touch the |
| 5618 | MSTCPY locks we've received early. */ |
| 5619 | |
| 5620 | error = find_rsb(ls, rl->rl_name, le16_to_cpu(rl->rl_namelen), |
| 5621 | from_nodeid, R_RECEIVE_RECOVER, &r); |
| 5622 | if (error) |
| 5623 | goto out; |
| 5624 | |
| 5625 | lock_rsb(r); |
| 5626 | |
| 5627 | if (dlm_no_directory(ls) && (dlm_dir_nodeid(r) != dlm_our_nodeid())) { |
| 5628 | log_error(ls, "dlm_recover_master_copy remote %d %x not dir", |
| 5629 | from_nodeid, remid); |
| 5630 | error = -EBADR; |
| 5631 | goto out_unlock; |
| 5632 | } |
| 5633 | |
| 5634 | lkb = search_remid(r, from_nodeid, remid); |
| 5635 | if (lkb) { |
| 5636 | error = -EEXIST; |
| 5637 | goto out_remid; |
| 5638 | } |
| 5639 | |
| 5640 | error = create_lkb(ls, &lkb); |
| 5641 | if (error) |
| 5642 | goto out_unlock; |
| 5643 | |
| 5644 | error = receive_rcom_lock_args(ls, lkb, r, rc); |
| 5645 | if (error) { |
| 5646 | __put_lkb(ls, lkb); |
| 5647 | goto out_unlock; |
| 5648 | } |
| 5649 | |
| 5650 | attach_lkb(r, lkb); |
| 5651 | add_lkb(r, lkb, rl->rl_status); |
| 5652 | ls->ls_recover_locks_in++; |
| 5653 | |
| 5654 | if (!list_empty(&r->res_waitqueue) || !list_empty(&r->res_convertqueue)) |
| 5655 | rsb_set_flag(r, RSB_RECOVER_GRANT); |
| 5656 | |
| 5657 | out_remid: |
| 5658 | /* this is the new value returned to the lock holder for |
| 5659 | saving in its process-copy lkb */ |
| 5660 | *rl_remid = cpu_to_le32(lkb->lkb_id); |
| 5661 | |
| 5662 | lkb->lkb_recover_seq = ls->ls_recover_seq; |
| 5663 | |
| 5664 | out_unlock: |
| 5665 | unlock_rsb(r); |
| 5666 | put_rsb(r); |
| 5667 | out: |
| 5668 | if (error && error != -EEXIST) |
| 5669 | log_rinfo(ls, "dlm_recover_master_copy remote %d %x error %d", |
| 5670 | from_nodeid, remid, error); |
| 5671 | *rl_result = cpu_to_le32(error); |
| 5672 | return error; |
| 5673 | } |
| 5674 | |
| 5675 | /* needs at least dlm_rcom + rcom_lock */ |
| 5676 | int dlm_recover_process_copy(struct dlm_ls *ls, const struct dlm_rcom *rc, |
| 5677 | uint64_t seq) |
| 5678 | { |
| 5679 | struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf; |
| 5680 | struct dlm_rsb *r; |
| 5681 | struct dlm_lkb *lkb; |
| 5682 | uint32_t lkid, remid; |
| 5683 | int error, result; |
| 5684 | |
| 5685 | lkid = le32_to_cpu(rl->rl_lkid); |
| 5686 | remid = le32_to_cpu(rl->rl_remid); |
| 5687 | result = le32_to_cpu(rl->rl_result); |
| 5688 | |
| 5689 | error = find_lkb(ls, lkid, &lkb); |
| 5690 | if (error) { |
| 5691 | log_error(ls, "dlm_recover_process_copy no %x remote %d %x %d", |
| 5692 | lkid, le32_to_cpu(rc->rc_header.h_nodeid), remid, |
| 5693 | result); |
| 5694 | return error; |
| 5695 | } |
| 5696 | |
| 5697 | r = lkb->lkb_resource; |
| 5698 | hold_rsb(r); |
| 5699 | lock_rsb(r); |
| 5700 | |
| 5701 | if (!is_process_copy(lkb)) { |
| 5702 | log_error(ls, "dlm_recover_process_copy bad %x remote %d %x %d", |
| 5703 | lkid, le32_to_cpu(rc->rc_header.h_nodeid), remid, |
| 5704 | result); |
| 5705 | dlm_dump_rsb(r); |
| 5706 | unlock_rsb(r); |
| 5707 | put_rsb(r); |
| 5708 | dlm_put_lkb(lkb); |
| 5709 | return -EINVAL; |
| 5710 | } |
| 5711 | |
| 5712 | switch (result) { |
| 5713 | case -EBADR: |
| 5714 | /* There's a chance the new master received our lock before |
| 5715 | dlm_recover_master_reply(), this wouldn't happen if we did |
| 5716 | a barrier between recover_masters and recover_locks. */ |
| 5717 | |
| 5718 | log_debug(ls, "dlm_recover_process_copy %x remote %d %x %d", |
| 5719 | lkid, le32_to_cpu(rc->rc_header.h_nodeid), remid, |
| 5720 | result); |
| 5721 | |
| 5722 | dlm_send_rcom_lock(r, lkb, seq); |
| 5723 | goto out; |
| 5724 | case -EEXIST: |
| 5725 | case 0: |
| 5726 | lkb->lkb_remid = remid; |
| 5727 | break; |
| 5728 | default: |
| 5729 | log_error(ls, "dlm_recover_process_copy %x remote %d %x %d unk", |
| 5730 | lkid, le32_to_cpu(rc->rc_header.h_nodeid), remid, |
| 5731 | result); |
| 5732 | } |
| 5733 | |
| 5734 | /* an ack for dlm_recover_locks() which waits for replies from |
| 5735 | all the locks it sends to new masters */ |
| 5736 | dlm_recovered_lock(r); |
| 5737 | out: |
| 5738 | unlock_rsb(r); |
| 5739 | put_rsb(r); |
| 5740 | dlm_put_lkb(lkb); |
| 5741 | |
| 5742 | return 0; |
| 5743 | } |
| 5744 | |
| 5745 | int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua, |
| 5746 | int mode, uint32_t flags, void *name, unsigned int namelen) |
| 5747 | { |
| 5748 | struct dlm_lkb *lkb; |
| 5749 | struct dlm_args args; |
| 5750 | bool do_put = true; |
| 5751 | int error; |
| 5752 | |
| 5753 | dlm_lock_recovery(ls); |
| 5754 | |
| 5755 | error = create_lkb(ls, &lkb); |
| 5756 | if (error) { |
| 5757 | kfree(ua); |
| 5758 | goto out; |
| 5759 | } |
| 5760 | |
| 5761 | trace_dlm_lock_start(ls, lkb, name, namelen, mode, flags); |
| 5762 | |
| 5763 | if (flags & DLM_LKF_VALBLK) { |
| 5764 | ua->lksb.sb_lvbptr = kzalloc(DLM_USER_LVB_LEN, GFP_NOFS); |
| 5765 | if (!ua->lksb.sb_lvbptr) { |
| 5766 | kfree(ua); |
| 5767 | error = -ENOMEM; |
| 5768 | goto out_put; |
| 5769 | } |
| 5770 | } |
| 5771 | error = set_lock_args(mode, &ua->lksb, flags, namelen, fake_astfn, ua, |
| 5772 | fake_bastfn, &args); |
| 5773 | if (error) { |
| 5774 | kfree(ua->lksb.sb_lvbptr); |
| 5775 | ua->lksb.sb_lvbptr = NULL; |
| 5776 | kfree(ua); |
| 5777 | goto out_put; |
| 5778 | } |
| 5779 | |
| 5780 | /* After ua is attached to lkb it will be freed by dlm_free_lkb(). |
| 5781 | When DLM_DFL_USER_BIT is set, the dlm knows that this is a userspace |
| 5782 | lock and that lkb_astparam is the dlm_user_args structure. */ |
| 5783 | set_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags); |
| 5784 | error = request_lock(ls, lkb, name, namelen, &args); |
| 5785 | |
| 5786 | switch (error) { |
| 5787 | case 0: |
| 5788 | break; |
| 5789 | case -EINPROGRESS: |
| 5790 | error = 0; |
| 5791 | break; |
| 5792 | case -EAGAIN: |
| 5793 | error = 0; |
| 5794 | fallthrough; |
| 5795 | default: |
| 5796 | goto out_put; |
| 5797 | } |
| 5798 | |
| 5799 | /* add this new lkb to the per-process list of locks */ |
| 5800 | spin_lock_bh(&ua->proc->locks_spin); |
| 5801 | hold_lkb(lkb); |
| 5802 | list_add_tail(&lkb->lkb_ownqueue, &ua->proc->locks); |
| 5803 | spin_unlock_bh(&ua->proc->locks_spin); |
| 5804 | do_put = false; |
| 5805 | out_put: |
| 5806 | trace_dlm_lock_end(ls, lkb, name, namelen, mode, flags, error, false); |
| 5807 | if (do_put) |
| 5808 | __put_lkb(ls, lkb); |
| 5809 | out: |
| 5810 | dlm_unlock_recovery(ls); |
| 5811 | return error; |
| 5812 | } |
| 5813 | |
| 5814 | int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, |
| 5815 | int mode, uint32_t flags, uint32_t lkid, char *lvb_in) |
| 5816 | { |
| 5817 | struct dlm_lkb *lkb; |
| 5818 | struct dlm_args args; |
| 5819 | struct dlm_user_args *ua; |
| 5820 | int error; |
| 5821 | |
| 5822 | dlm_lock_recovery(ls); |
| 5823 | |
| 5824 | error = find_lkb(ls, lkid, &lkb); |
| 5825 | if (error) |
| 5826 | goto out; |
| 5827 | |
| 5828 | trace_dlm_lock_start(ls, lkb, NULL, 0, mode, flags); |
| 5829 | |
| 5830 | /* user can change the params on its lock when it converts it, or |
| 5831 | add an lvb that didn't exist before */ |
| 5832 | |
| 5833 | ua = lkb->lkb_ua; |
| 5834 | |
| 5835 | if (flags & DLM_LKF_VALBLK && !ua->lksb.sb_lvbptr) { |
| 5836 | ua->lksb.sb_lvbptr = kzalloc(DLM_USER_LVB_LEN, GFP_NOFS); |
| 5837 | if (!ua->lksb.sb_lvbptr) { |
| 5838 | error = -ENOMEM; |
| 5839 | goto out_put; |
| 5840 | } |
| 5841 | } |
| 5842 | if (lvb_in && ua->lksb.sb_lvbptr) |
| 5843 | memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN); |
| 5844 | |
| 5845 | ua->xid = ua_tmp->xid; |
| 5846 | ua->castparam = ua_tmp->castparam; |
| 5847 | ua->castaddr = ua_tmp->castaddr; |
| 5848 | ua->bastparam = ua_tmp->bastparam; |
| 5849 | ua->bastaddr = ua_tmp->bastaddr; |
| 5850 | ua->user_lksb = ua_tmp->user_lksb; |
| 5851 | |
| 5852 | error = set_lock_args(mode, &ua->lksb, flags, 0, fake_astfn, ua, |
| 5853 | fake_bastfn, &args); |
| 5854 | if (error) |
| 5855 | goto out_put; |
| 5856 | |
| 5857 | error = convert_lock(ls, lkb, &args); |
| 5858 | |
| 5859 | if (error == -EINPROGRESS || error == -EAGAIN || error == -EDEADLK) |
| 5860 | error = 0; |
| 5861 | out_put: |
| 5862 | trace_dlm_lock_end(ls, lkb, NULL, 0, mode, flags, error, false); |
| 5863 | dlm_put_lkb(lkb); |
| 5864 | out: |
| 5865 | dlm_unlock_recovery(ls); |
| 5866 | kfree(ua_tmp); |
| 5867 | return error; |
| 5868 | } |
| 5869 | |
| 5870 | /* |
| 5871 | * The caller asks for an orphan lock on a given resource with a given mode. |
| 5872 | * If a matching lock exists, it's moved to the owner's list of locks and |
| 5873 | * the lkid is returned. |
| 5874 | */ |
| 5875 | |
| 5876 | int dlm_user_adopt_orphan(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, |
| 5877 | int mode, uint32_t flags, void *name, unsigned int namelen, |
| 5878 | uint32_t *lkid) |
| 5879 | { |
| 5880 | struct dlm_lkb *lkb = NULL, *iter; |
| 5881 | struct dlm_user_args *ua; |
| 5882 | int found_other_mode = 0; |
| 5883 | int rv = 0; |
| 5884 | |
| 5885 | spin_lock_bh(&ls->ls_orphans_lock); |
| 5886 | list_for_each_entry(iter, &ls->ls_orphans, lkb_ownqueue) { |
| 5887 | if (iter->lkb_resource->res_length != namelen) |
| 5888 | continue; |
| 5889 | if (memcmp(iter->lkb_resource->res_name, name, namelen)) |
| 5890 | continue; |
| 5891 | if (iter->lkb_grmode != mode) { |
| 5892 | found_other_mode = 1; |
| 5893 | continue; |
| 5894 | } |
| 5895 | |
| 5896 | lkb = iter; |
| 5897 | list_del_init(&iter->lkb_ownqueue); |
| 5898 | clear_bit(DLM_DFL_ORPHAN_BIT, &iter->lkb_dflags); |
| 5899 | *lkid = iter->lkb_id; |
| 5900 | break; |
| 5901 | } |
| 5902 | spin_unlock_bh(&ls->ls_orphans_lock); |
| 5903 | |
| 5904 | if (!lkb && found_other_mode) { |
| 5905 | rv = -EAGAIN; |
| 5906 | goto out; |
| 5907 | } |
| 5908 | |
| 5909 | if (!lkb) { |
| 5910 | rv = -ENOENT; |
| 5911 | goto out; |
| 5912 | } |
| 5913 | |
| 5914 | lkb->lkb_exflags = flags; |
| 5915 | lkb->lkb_ownpid = (int) current->pid; |
| 5916 | |
| 5917 | ua = lkb->lkb_ua; |
| 5918 | |
| 5919 | ua->proc = ua_tmp->proc; |
| 5920 | ua->xid = ua_tmp->xid; |
| 5921 | ua->castparam = ua_tmp->castparam; |
| 5922 | ua->castaddr = ua_tmp->castaddr; |
| 5923 | ua->bastparam = ua_tmp->bastparam; |
| 5924 | ua->bastaddr = ua_tmp->bastaddr; |
| 5925 | ua->user_lksb = ua_tmp->user_lksb; |
| 5926 | |
| 5927 | /* |
| 5928 | * The lkb reference from the ls_orphans list was not |
| 5929 | * removed above, and is now considered the reference |
| 5930 | * for the proc locks list. |
| 5931 | */ |
| 5932 | |
| 5933 | spin_lock_bh(&ua->proc->locks_spin); |
| 5934 | list_add_tail(&lkb->lkb_ownqueue, &ua->proc->locks); |
| 5935 | spin_unlock_bh(&ua->proc->locks_spin); |
| 5936 | out: |
| 5937 | kfree(ua_tmp); |
| 5938 | return rv; |
| 5939 | } |
| 5940 | |
| 5941 | int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, |
| 5942 | uint32_t flags, uint32_t lkid, char *lvb_in) |
| 5943 | { |
| 5944 | struct dlm_lkb *lkb; |
| 5945 | struct dlm_args args; |
| 5946 | struct dlm_user_args *ua; |
| 5947 | int error; |
| 5948 | |
| 5949 | dlm_lock_recovery(ls); |
| 5950 | |
| 5951 | error = find_lkb(ls, lkid, &lkb); |
| 5952 | if (error) |
| 5953 | goto out; |
| 5954 | |
| 5955 | trace_dlm_unlock_start(ls, lkb, flags); |
| 5956 | |
| 5957 | ua = lkb->lkb_ua; |
| 5958 | |
| 5959 | if (lvb_in && ua->lksb.sb_lvbptr) |
| 5960 | memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN); |
| 5961 | if (ua_tmp->castparam) |
| 5962 | ua->castparam = ua_tmp->castparam; |
| 5963 | ua->user_lksb = ua_tmp->user_lksb; |
| 5964 | |
| 5965 | error = set_unlock_args(flags, ua, &args); |
| 5966 | if (error) |
| 5967 | goto out_put; |
| 5968 | |
| 5969 | error = unlock_lock(ls, lkb, &args); |
| 5970 | |
| 5971 | if (error == -DLM_EUNLOCK) |
| 5972 | error = 0; |
| 5973 | /* from validate_unlock_args() */ |
| 5974 | if (error == -EBUSY && (flags & DLM_LKF_FORCEUNLOCK)) |
| 5975 | error = 0; |
| 5976 | if (error) |
| 5977 | goto out_put; |
| 5978 | |
| 5979 | spin_lock_bh(&ua->proc->locks_spin); |
| 5980 | /* dlm_user_add_cb() may have already taken lkb off the proc list */ |
| 5981 | if (!list_empty(&lkb->lkb_ownqueue)) |
| 5982 | list_move(&lkb->lkb_ownqueue, &ua->proc->unlocking); |
| 5983 | spin_unlock_bh(&ua->proc->locks_spin); |
| 5984 | out_put: |
| 5985 | trace_dlm_unlock_end(ls, lkb, flags, error); |
| 5986 | dlm_put_lkb(lkb); |
| 5987 | out: |
| 5988 | dlm_unlock_recovery(ls); |
| 5989 | kfree(ua_tmp); |
| 5990 | return error; |
| 5991 | } |
| 5992 | |
| 5993 | int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, |
| 5994 | uint32_t flags, uint32_t lkid) |
| 5995 | { |
| 5996 | struct dlm_lkb *lkb; |
| 5997 | struct dlm_args args; |
| 5998 | struct dlm_user_args *ua; |
| 5999 | int error; |
| 6000 | |
| 6001 | dlm_lock_recovery(ls); |
| 6002 | |
| 6003 | error = find_lkb(ls, lkid, &lkb); |
| 6004 | if (error) |
| 6005 | goto out; |
| 6006 | |
| 6007 | trace_dlm_unlock_start(ls, lkb, flags); |
| 6008 | |
| 6009 | ua = lkb->lkb_ua; |
| 6010 | if (ua_tmp->castparam) |
| 6011 | ua->castparam = ua_tmp->castparam; |
| 6012 | ua->user_lksb = ua_tmp->user_lksb; |
| 6013 | |
| 6014 | error = set_unlock_args(flags, ua, &args); |
| 6015 | if (error) |
| 6016 | goto out_put; |
| 6017 | |
| 6018 | error = cancel_lock(ls, lkb, &args); |
| 6019 | |
| 6020 | if (error == -DLM_ECANCEL) |
| 6021 | error = 0; |
| 6022 | /* from validate_unlock_args() */ |
| 6023 | if (error == -EBUSY) |
| 6024 | error = 0; |
| 6025 | out_put: |
| 6026 | trace_dlm_unlock_end(ls, lkb, flags, error); |
| 6027 | dlm_put_lkb(lkb); |
| 6028 | out: |
| 6029 | dlm_unlock_recovery(ls); |
| 6030 | kfree(ua_tmp); |
| 6031 | return error; |
| 6032 | } |
| 6033 | |
| 6034 | int dlm_user_deadlock(struct dlm_ls *ls, uint32_t flags, uint32_t lkid) |
| 6035 | { |
| 6036 | struct dlm_lkb *lkb; |
| 6037 | struct dlm_args args; |
| 6038 | struct dlm_user_args *ua; |
| 6039 | struct dlm_rsb *r; |
| 6040 | int error; |
| 6041 | |
| 6042 | dlm_lock_recovery(ls); |
| 6043 | |
| 6044 | error = find_lkb(ls, lkid, &lkb); |
| 6045 | if (error) |
| 6046 | goto out; |
| 6047 | |
| 6048 | trace_dlm_unlock_start(ls, lkb, flags); |
| 6049 | |
| 6050 | ua = lkb->lkb_ua; |
| 6051 | |
| 6052 | error = set_unlock_args(flags, ua, &args); |
| 6053 | if (error) |
| 6054 | goto out_put; |
| 6055 | |
| 6056 | /* same as cancel_lock(), but set DEADLOCK_CANCEL after lock_rsb */ |
| 6057 | |
| 6058 | r = lkb->lkb_resource; |
| 6059 | hold_rsb(r); |
| 6060 | lock_rsb(r); |
| 6061 | |
| 6062 | error = validate_unlock_args(lkb, &args); |
| 6063 | if (error) |
| 6064 | goto out_r; |
| 6065 | set_bit(DLM_IFL_DEADLOCK_CANCEL_BIT, &lkb->lkb_iflags); |
| 6066 | |
| 6067 | error = _cancel_lock(r, lkb); |
| 6068 | out_r: |
| 6069 | unlock_rsb(r); |
| 6070 | put_rsb(r); |
| 6071 | |
| 6072 | if (error == -DLM_ECANCEL) |
| 6073 | error = 0; |
| 6074 | /* from validate_unlock_args() */ |
| 6075 | if (error == -EBUSY) |
| 6076 | error = 0; |
| 6077 | out_put: |
| 6078 | trace_dlm_unlock_end(ls, lkb, flags, error); |
| 6079 | dlm_put_lkb(lkb); |
| 6080 | out: |
| 6081 | dlm_unlock_recovery(ls); |
| 6082 | return error; |
| 6083 | } |
| 6084 | |
| 6085 | /* lkb's that are removed from the waiters list by revert are just left on the |
| 6086 | orphans list with the granted orphan locks, to be freed by purge */ |
| 6087 | |
| 6088 | static int orphan_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb) |
| 6089 | { |
| 6090 | struct dlm_args args; |
| 6091 | int error; |
| 6092 | |
| 6093 | hold_lkb(lkb); /* reference for the ls_orphans list */ |
| 6094 | spin_lock_bh(&ls->ls_orphans_lock); |
| 6095 | list_add_tail(&lkb->lkb_ownqueue, &ls->ls_orphans); |
| 6096 | spin_unlock_bh(&ls->ls_orphans_lock); |
| 6097 | |
| 6098 | set_unlock_args(0, lkb->lkb_ua, &args); |
| 6099 | |
| 6100 | error = cancel_lock(ls, lkb, &args); |
| 6101 | if (error == -DLM_ECANCEL) |
| 6102 | error = 0; |
| 6103 | return error; |
| 6104 | } |
| 6105 | |
| 6106 | /* The FORCEUNLOCK flag allows the unlock to go ahead even if the lkb isn't |
| 6107 | granted. Regardless of what rsb queue the lock is on, it's removed and |
| 6108 | freed. The IVVALBLK flag causes the lvb on the resource to be invalidated |
| 6109 | if our lock is PW/EX (it's ignored if our granted mode is smaller.) */ |
| 6110 | |
| 6111 | static int unlock_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb) |
| 6112 | { |
| 6113 | struct dlm_args args; |
| 6114 | int error; |
| 6115 | |
| 6116 | set_unlock_args(DLM_LKF_FORCEUNLOCK | DLM_LKF_IVVALBLK, |
| 6117 | lkb->lkb_ua, &args); |
| 6118 | |
| 6119 | error = unlock_lock(ls, lkb, &args); |
| 6120 | if (error == -DLM_EUNLOCK) |
| 6121 | error = 0; |
| 6122 | return error; |
| 6123 | } |
| 6124 | |
| 6125 | /* We have to release clear_proc_locks mutex before calling unlock_proc_lock() |
| 6126 | (which does lock_rsb) due to deadlock with receiving a message that does |
| 6127 | lock_rsb followed by dlm_user_add_cb() */ |
| 6128 | |
| 6129 | static struct dlm_lkb *del_proc_lock(struct dlm_ls *ls, |
| 6130 | struct dlm_user_proc *proc) |
| 6131 | { |
| 6132 | struct dlm_lkb *lkb = NULL; |
| 6133 | |
| 6134 | spin_lock_bh(&ls->ls_clear_proc_locks); |
| 6135 | if (list_empty(&proc->locks)) |
| 6136 | goto out; |
| 6137 | |
| 6138 | lkb = list_entry(proc->locks.next, struct dlm_lkb, lkb_ownqueue); |
| 6139 | list_del_init(&lkb->lkb_ownqueue); |
| 6140 | |
| 6141 | if (lkb->lkb_exflags & DLM_LKF_PERSISTENT) |
| 6142 | set_bit(DLM_DFL_ORPHAN_BIT, &lkb->lkb_dflags); |
| 6143 | else |
| 6144 | set_bit(DLM_IFL_DEAD_BIT, &lkb->lkb_iflags); |
| 6145 | out: |
| 6146 | spin_unlock_bh(&ls->ls_clear_proc_locks); |
| 6147 | return lkb; |
| 6148 | } |
| 6149 | |
| 6150 | /* The ls_clear_proc_locks mutex protects against dlm_user_add_cb() which |
| 6151 | 1) references lkb->ua which we free here and 2) adds lkbs to proc->asts, |
| 6152 | which we clear here. */ |
| 6153 | |
| 6154 | /* proc CLOSING flag is set so no more device_reads should look at proc->asts |
| 6155 | list, and no more device_writes should add lkb's to proc->locks list; so we |
| 6156 | shouldn't need to take asts_spin or locks_spin here. this assumes that |
| 6157 | device reads/writes/closes are serialized -- FIXME: we may need to serialize |
| 6158 | them ourself. */ |
| 6159 | |
| 6160 | void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc) |
| 6161 | { |
| 6162 | struct dlm_callback *cb, *cb_safe; |
| 6163 | struct dlm_lkb *lkb, *safe; |
| 6164 | |
| 6165 | dlm_lock_recovery(ls); |
| 6166 | |
| 6167 | while (1) { |
| 6168 | lkb = del_proc_lock(ls, proc); |
| 6169 | if (!lkb) |
| 6170 | break; |
| 6171 | if (lkb->lkb_exflags & DLM_LKF_PERSISTENT) |
| 6172 | orphan_proc_lock(ls, lkb); |
| 6173 | else |
| 6174 | unlock_proc_lock(ls, lkb); |
| 6175 | |
| 6176 | /* this removes the reference for the proc->locks list |
| 6177 | added by dlm_user_request, it may result in the lkb |
| 6178 | being freed */ |
| 6179 | |
| 6180 | dlm_put_lkb(lkb); |
| 6181 | } |
| 6182 | |
| 6183 | spin_lock_bh(&ls->ls_clear_proc_locks); |
| 6184 | |
| 6185 | /* in-progress unlocks */ |
| 6186 | list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) { |
| 6187 | list_del_init(&lkb->lkb_ownqueue); |
| 6188 | set_bit(DLM_IFL_DEAD_BIT, &lkb->lkb_iflags); |
| 6189 | dlm_put_lkb(lkb); |
| 6190 | } |
| 6191 | |
| 6192 | list_for_each_entry_safe(cb, cb_safe, &proc->asts, list) { |
| 6193 | list_del(&cb->list); |
| 6194 | dlm_free_cb(cb); |
| 6195 | } |
| 6196 | |
| 6197 | spin_unlock_bh(&ls->ls_clear_proc_locks); |
| 6198 | dlm_unlock_recovery(ls); |
| 6199 | } |
| 6200 | |
| 6201 | static void purge_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc) |
| 6202 | { |
| 6203 | struct dlm_callback *cb, *cb_safe; |
| 6204 | struct dlm_lkb *lkb, *safe; |
| 6205 | |
| 6206 | while (1) { |
| 6207 | lkb = NULL; |
| 6208 | spin_lock_bh(&proc->locks_spin); |
| 6209 | if (!list_empty(&proc->locks)) { |
| 6210 | lkb = list_entry(proc->locks.next, struct dlm_lkb, |
| 6211 | lkb_ownqueue); |
| 6212 | list_del_init(&lkb->lkb_ownqueue); |
| 6213 | } |
| 6214 | spin_unlock_bh(&proc->locks_spin); |
| 6215 | |
| 6216 | if (!lkb) |
| 6217 | break; |
| 6218 | |
| 6219 | set_bit(DLM_IFL_DEAD_BIT, &lkb->lkb_iflags); |
| 6220 | unlock_proc_lock(ls, lkb); |
| 6221 | dlm_put_lkb(lkb); /* ref from proc->locks list */ |
| 6222 | } |
| 6223 | |
| 6224 | spin_lock_bh(&proc->locks_spin); |
| 6225 | list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) { |
| 6226 | list_del_init(&lkb->lkb_ownqueue); |
| 6227 | set_bit(DLM_IFL_DEAD_BIT, &lkb->lkb_iflags); |
| 6228 | dlm_put_lkb(lkb); |
| 6229 | } |
| 6230 | spin_unlock_bh(&proc->locks_spin); |
| 6231 | |
| 6232 | spin_lock_bh(&proc->asts_spin); |
| 6233 | list_for_each_entry_safe(cb, cb_safe, &proc->asts, list) { |
| 6234 | list_del(&cb->list); |
| 6235 | dlm_free_cb(cb); |
| 6236 | } |
| 6237 | spin_unlock_bh(&proc->asts_spin); |
| 6238 | } |
| 6239 | |
| 6240 | /* pid of 0 means purge all orphans */ |
| 6241 | |
| 6242 | static void do_purge(struct dlm_ls *ls, int nodeid, int pid) |
| 6243 | { |
| 6244 | struct dlm_lkb *lkb, *safe; |
| 6245 | |
| 6246 | spin_lock_bh(&ls->ls_orphans_lock); |
| 6247 | list_for_each_entry_safe(lkb, safe, &ls->ls_orphans, lkb_ownqueue) { |
| 6248 | if (pid && lkb->lkb_ownpid != pid) |
| 6249 | continue; |
| 6250 | unlock_proc_lock(ls, lkb); |
| 6251 | list_del_init(&lkb->lkb_ownqueue); |
| 6252 | dlm_put_lkb(lkb); |
| 6253 | } |
| 6254 | spin_unlock_bh(&ls->ls_orphans_lock); |
| 6255 | } |
| 6256 | |
| 6257 | static int send_purge(struct dlm_ls *ls, int nodeid, int pid) |
| 6258 | { |
| 6259 | struct dlm_message *ms; |
| 6260 | struct dlm_mhandle *mh; |
| 6261 | int error; |
| 6262 | |
| 6263 | error = _create_message(ls, sizeof(struct dlm_message), nodeid, |
| 6264 | DLM_MSG_PURGE, &ms, &mh); |
| 6265 | if (error) |
| 6266 | return error; |
| 6267 | ms->m_nodeid = cpu_to_le32(nodeid); |
| 6268 | ms->m_pid = cpu_to_le32(pid); |
| 6269 | |
| 6270 | return send_message(mh, ms, NULL, 0); |
| 6271 | } |
| 6272 | |
| 6273 | int dlm_user_purge(struct dlm_ls *ls, struct dlm_user_proc *proc, |
| 6274 | int nodeid, int pid) |
| 6275 | { |
| 6276 | int error = 0; |
| 6277 | |
| 6278 | if (nodeid && (nodeid != dlm_our_nodeid())) { |
| 6279 | error = send_purge(ls, nodeid, pid); |
| 6280 | } else { |
| 6281 | dlm_lock_recovery(ls); |
| 6282 | if (pid == current->pid) |
| 6283 | purge_proc_locks(ls, proc); |
| 6284 | else |
| 6285 | do_purge(ls, nodeid, pid); |
| 6286 | dlm_unlock_recovery(ls); |
| 6287 | } |
| 6288 | return error; |
| 6289 | } |
| 6290 | |
| 6291 | /* debug functionality */ |
| 6292 | int dlm_debug_add_lkb(struct dlm_ls *ls, uint32_t lkb_id, char *name, int len, |
| 6293 | int lkb_nodeid, unsigned int lkb_dflags, int lkb_status) |
| 6294 | { |
| 6295 | struct dlm_lksb *lksb; |
| 6296 | struct dlm_lkb *lkb; |
| 6297 | struct dlm_rsb *r; |
| 6298 | int error; |
| 6299 | |
| 6300 | /* we currently can't set a valid user lock */ |
| 6301 | if (lkb_dflags & BIT(DLM_DFL_USER_BIT)) |
| 6302 | return -EOPNOTSUPP; |
| 6303 | |
| 6304 | lksb = kzalloc(sizeof(*lksb), GFP_NOFS); |
| 6305 | if (!lksb) |
| 6306 | return -ENOMEM; |
| 6307 | |
| 6308 | error = _create_lkb(ls, &lkb, lkb_id, lkb_id + 1); |
| 6309 | if (error) { |
| 6310 | kfree(lksb); |
| 6311 | return error; |
| 6312 | } |
| 6313 | |
| 6314 | dlm_set_dflags_val(lkb, lkb_dflags); |
| 6315 | lkb->lkb_nodeid = lkb_nodeid; |
| 6316 | lkb->lkb_lksb = lksb; |
| 6317 | /* user specific pointer, just don't have it NULL for kernel locks */ |
| 6318 | if (~lkb_dflags & BIT(DLM_DFL_USER_BIT)) |
| 6319 | lkb->lkb_astparam = (void *)0xDEADBEEF; |
| 6320 | |
| 6321 | error = find_rsb(ls, name, len, 0, R_REQUEST, &r); |
| 6322 | if (error) { |
| 6323 | kfree(lksb); |
| 6324 | __put_lkb(ls, lkb); |
| 6325 | return error; |
| 6326 | } |
| 6327 | |
| 6328 | lock_rsb(r); |
| 6329 | attach_lkb(r, lkb); |
| 6330 | add_lkb(r, lkb, lkb_status); |
| 6331 | unlock_rsb(r); |
| 6332 | put_rsb(r); |
| 6333 | |
| 6334 | return 0; |
| 6335 | } |
| 6336 | |
| 6337 | int dlm_debug_add_lkb_to_waiters(struct dlm_ls *ls, uint32_t lkb_id, |
| 6338 | int mstype, int to_nodeid) |
| 6339 | { |
| 6340 | struct dlm_lkb *lkb; |
| 6341 | int error; |
| 6342 | |
| 6343 | error = find_lkb(ls, lkb_id, &lkb); |
| 6344 | if (error) |
| 6345 | return error; |
| 6346 | |
| 6347 | error = add_to_waiters(lkb, mstype, to_nodeid); |
| 6348 | dlm_put_lkb(lkb); |
| 6349 | return error; |
| 6350 | } |
| 6351 | |