1/******************************************************************************
   2*******************************************************************************
   3**
   4**  Copyright (C) 2005-2010 Red Hat, Inc.  All rights reserved.
   5**
   6**  This copyrighted material is made available to anyone wishing to use,
   7**  modify, copy, or redistribute it subject to the terms and conditions
   8**  of the GNU General Public License v.2.
   9**
  10*******************************************************************************
  11******************************************************************************/
  12
  13/* Central locking logic has four stages:
  14
  15   dlm_lock()
  16   dlm_unlock()
  17
  18   request_lock(ls, lkb)
  19   convert_lock(ls, lkb)
  20   unlock_lock(ls, lkb)
  21   cancel_lock(ls, lkb)
  22
  23   _request_lock(r, lkb)
  24   _convert_lock(r, lkb)
  25   _unlock_lock(r, lkb)
  26   _cancel_lock(r, lkb)
  27
  28   do_request(r, lkb)
  29   do_convert(r, lkb)
  30   do_unlock(r, lkb)
  31   do_cancel(r, lkb)
  32
  33   Stage 1 (lock, unlock) is mainly about checking input args and
  34   splitting into one of the four main operations:
  35
  36       dlm_lock          = request_lock
  37       dlm_lock+CONVERT  = convert_lock
  38       dlm_unlock        = unlock_lock
  39       dlm_unlock+CANCEL = cancel_lock
  40
  41   Stage 2, xxxx_lock(), just finds and locks the relevant rsb which is
  42   provided to the next stage.
  43
  44   Stage 3, _xxxx_lock(), determines if the operation is local or remote.
  45   When remote, it calls send_xxxx(), when local it calls do_xxxx().
  46
  47   Stage 4, do_xxxx(), is the guts of the operation.  It manipulates the
  48   given rsb and lkb and queues callbacks.
  49
  50   For remote operations, send_xxxx() results in the corresponding do_xxxx()
  51   function being executed on the remote node.  The connecting send/receive
  52   calls on local (L) and remote (R) nodes:
  53
  54   L: send_xxxx()              ->  R: receive_xxxx()
  55                                   R: do_xxxx()
  56   L: receive_xxxx_reply()     <-  R: send_xxxx_reply()
  57*/
  58#include <linux/types.h>
 
  59#include <linux/slab.h>
  60#include "dlm_internal.h"
  61#include <linux/dlm_device.h>
  62#include "memory.h"
  63#include "lowcomms.h"
  64#include "requestqueue.h"
  65#include "util.h"
  66#include "dir.h"
  67#include "member.h"
  68#include "lockspace.h"
  69#include "ast.h"
  70#include "lock.h"
  71#include "rcom.h"
  72#include "recover.h"
  73#include "lvb_table.h"
  74#include "user.h"
  75#include "config.h"
  76
  77static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb);
  78static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb);
  79static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb);
  80static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb);
  81static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb);
  82static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode);
  83static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb);
  84static int send_remove(struct dlm_rsb *r);
  85static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
  86static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
  87static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
  88				    struct dlm_message *ms);
  89static int receive_extralen(struct dlm_message *ms);
  90static void do_purge(struct dlm_ls *ls, int nodeid, int pid);
  91static void del_timeout(struct dlm_lkb *lkb);
 
  92
  93/*
  94 * Lock compatibilty matrix - thanks Steve
  95 * UN = Unlocked state. Not really a state, used as a flag
  96 * PD = Padding. Used to make the matrix a nice power of two in size
  97 * Other states are the same as the VMS DLM.
  98 * Usage: matrix[grmode+1][rqmode+1]  (although m[rq+1][gr+1] is the same)
  99 */
 100
 101static const int __dlm_compat_matrix[8][8] = {
 102      /* UN NL CR CW PR PW EX PD */
 103        {1, 1, 1, 1, 1, 1, 1, 0},       /* UN */
 104        {1, 1, 1, 1, 1, 1, 1, 0},       /* NL */
 105        {1, 1, 1, 1, 1, 1, 0, 0},       /* CR */
 106        {1, 1, 1, 1, 0, 0, 0, 0},       /* CW */
 107        {1, 1, 1, 0, 1, 0, 0, 0},       /* PR */
 108        {1, 1, 1, 0, 0, 0, 0, 0},       /* PW */
 109        {1, 1, 0, 0, 0, 0, 0, 0},       /* EX */
 110        {0, 0, 0, 0, 0, 0, 0, 0}        /* PD */
 111};
 112
 113/*
 114 * This defines the direction of transfer of LVB data.
 115 * Granted mode is the row; requested mode is the column.
 116 * Usage: matrix[grmode+1][rqmode+1]
 117 * 1 = LVB is returned to the caller
 118 * 0 = LVB is written to the resource
 119 * -1 = nothing happens to the LVB
 120 */
 121
 122const int dlm_lvb_operations[8][8] = {
 123        /* UN   NL  CR  CW  PR  PW  EX  PD*/
 124        {  -1,  1,  1,  1,  1,  1,  1, -1 }, /* UN */
 125        {  -1,  1,  1,  1,  1,  1,  1,  0 }, /* NL */
 126        {  -1, -1,  1,  1,  1,  1,  1,  0 }, /* CR */
 127        {  -1, -1, -1,  1,  1,  1,  1,  0 }, /* CW */
 128        {  -1, -1, -1, -1,  1,  1,  1,  0 }, /* PR */
 129        {  -1,  0,  0,  0,  0,  0,  1,  0 }, /* PW */
 130        {  -1,  0,  0,  0,  0,  0,  0,  0 }, /* EX */
 131        {  -1,  0,  0,  0,  0,  0,  0,  0 }  /* PD */
 132};
 133
 134#define modes_compat(gr, rq) \
 135	__dlm_compat_matrix[(gr)->lkb_grmode + 1][(rq)->lkb_rqmode + 1]
 136
 137int dlm_modes_compat(int mode1, int mode2)
 138{
 139	return __dlm_compat_matrix[mode1 + 1][mode2 + 1];
 140}
 141
 142/*
 143 * Compatibility matrix for conversions with QUECVT set.
 144 * Granted mode is the row; requested mode is the column.
 145 * Usage: matrix[grmode+1][rqmode+1]
 146 */
 147
 148static const int __quecvt_compat_matrix[8][8] = {
 149      /* UN NL CR CW PR PW EX PD */
 150        {0, 0, 0, 0, 0, 0, 0, 0},       /* UN */
 151        {0, 0, 1, 1, 1, 1, 1, 0},       /* NL */
 152        {0, 0, 0, 1, 1, 1, 1, 0},       /* CR */
 153        {0, 0, 0, 0, 1, 1, 1, 0},       /* CW */
 154        {0, 0, 0, 1, 0, 1, 1, 0},       /* PR */
 155        {0, 0, 0, 0, 0, 0, 1, 0},       /* PW */
 156        {0, 0, 0, 0, 0, 0, 0, 0},       /* EX */
 157        {0, 0, 0, 0, 0, 0, 0, 0}        /* PD */
 158};
 159
 160void dlm_print_lkb(struct dlm_lkb *lkb)
 161{
 162	printk(KERN_ERR "lkb: nodeid %d id %x remid %x exflags %x flags %x\n"
 163	       "     status %d rqmode %d grmode %d wait_type %d\n",
 164	       lkb->lkb_nodeid, lkb->lkb_id, lkb->lkb_remid, lkb->lkb_exflags,
 165	       lkb->lkb_flags, lkb->lkb_status, lkb->lkb_rqmode,
 166	       lkb->lkb_grmode, lkb->lkb_wait_type);
 
 167}
 168
 169static void dlm_print_rsb(struct dlm_rsb *r)
 170{
 171	printk(KERN_ERR "rsb: nodeid %d flags %lx first %x rlc %d name %s\n",
 172	       r->res_nodeid, r->res_flags, r->res_first_lkid,
 173	       r->res_recover_locks_count, r->res_name);
 
 
 174}
 175
 176void dlm_dump_rsb(struct dlm_rsb *r)
 177{
 178	struct dlm_lkb *lkb;
 179
 180	dlm_print_rsb(r);
 181
 182	printk(KERN_ERR "rsb: root_list empty %d recover_list empty %d\n",
 183	       list_empty(&r->res_root_list), list_empty(&r->res_recover_list));
 184	printk(KERN_ERR "rsb lookup list\n");
 185	list_for_each_entry(lkb, &r->res_lookup, lkb_rsb_lookup)
 186		dlm_print_lkb(lkb);
 187	printk(KERN_ERR "rsb grant queue:\n");
 188	list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue)
 189		dlm_print_lkb(lkb);
 190	printk(KERN_ERR "rsb convert queue:\n");
 191	list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue)
 192		dlm_print_lkb(lkb);
 193	printk(KERN_ERR "rsb wait queue:\n");
 194	list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue)
 195		dlm_print_lkb(lkb);
 196}
 197
 198/* Threads cannot use the lockspace while it's being recovered */
 199
 200static inline void dlm_lock_recovery(struct dlm_ls *ls)
 201{
 202	down_read(&ls->ls_in_recovery);
 203}
 204
 205void dlm_unlock_recovery(struct dlm_ls *ls)
 206{
 207	up_read(&ls->ls_in_recovery);
 208}
 209
 210int dlm_lock_recovery_try(struct dlm_ls *ls)
 211{
 212	return down_read_trylock(&ls->ls_in_recovery);
 213}
 214
 215static inline int can_be_queued(struct dlm_lkb *lkb)
 216{
 217	return !(lkb->lkb_exflags & DLM_LKF_NOQUEUE);
 218}
 219
 220static inline int force_blocking_asts(struct dlm_lkb *lkb)
 221{
 222	return (lkb->lkb_exflags & DLM_LKF_NOQUEUEBAST);
 223}
 224
 225static inline int is_demoted(struct dlm_lkb *lkb)
 226{
 227	return (lkb->lkb_sbflags & DLM_SBF_DEMOTED);
 228}
 229
 230static inline int is_altmode(struct dlm_lkb *lkb)
 231{
 232	return (lkb->lkb_sbflags & DLM_SBF_ALTMODE);
 233}
 234
 235static inline int is_granted(struct dlm_lkb *lkb)
 236{
 237	return (lkb->lkb_status == DLM_LKSTS_GRANTED);
 238}
 239
 240static inline int is_remote(struct dlm_rsb *r)
 241{
 242	DLM_ASSERT(r->res_nodeid >= 0, dlm_print_rsb(r););
 243	return !!r->res_nodeid;
 244}
 245
 246static inline int is_process_copy(struct dlm_lkb *lkb)
 247{
 248	return (lkb->lkb_nodeid && !(lkb->lkb_flags & DLM_IFL_MSTCPY));
 249}
 250
 251static inline int is_master_copy(struct dlm_lkb *lkb)
 252{
 253	if (lkb->lkb_flags & DLM_IFL_MSTCPY)
 254		DLM_ASSERT(lkb->lkb_nodeid, dlm_print_lkb(lkb););
 255	return (lkb->lkb_flags & DLM_IFL_MSTCPY) ? 1 : 0;
 256}
 257
 258static inline int middle_conversion(struct dlm_lkb *lkb)
 259{
 260	if ((lkb->lkb_grmode==DLM_LOCK_PR && lkb->lkb_rqmode==DLM_LOCK_CW) ||
 261	    (lkb->lkb_rqmode==DLM_LOCK_PR && lkb->lkb_grmode==DLM_LOCK_CW))
 262		return 1;
 263	return 0;
 264}
 265
 266static inline int down_conversion(struct dlm_lkb *lkb)
 267{
 268	return (!middle_conversion(lkb) && lkb->lkb_rqmode < lkb->lkb_grmode);
 269}
 270
 271static inline int is_overlap_unlock(struct dlm_lkb *lkb)
 272{
 273	return lkb->lkb_flags & DLM_IFL_OVERLAP_UNLOCK;
 274}
 275
 276static inline int is_overlap_cancel(struct dlm_lkb *lkb)
 277{
 278	return lkb->lkb_flags & DLM_IFL_OVERLAP_CANCEL;
 279}
 280
 281static inline int is_overlap(struct dlm_lkb *lkb)
 282{
 283	return (lkb->lkb_flags & (DLM_IFL_OVERLAP_UNLOCK |
 284				  DLM_IFL_OVERLAP_CANCEL));
 285}
 286
 287static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
 288{
 289	if (is_master_copy(lkb))
 290		return;
 291
 292	del_timeout(lkb);
 293
 294	DLM_ASSERT(lkb->lkb_lksb, dlm_print_lkb(lkb););
 295
 296	/* if the operation was a cancel, then return -DLM_ECANCEL, if a
 297	   timeout caused the cancel then return -ETIMEDOUT */
 298	if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_TIMEOUT_CANCEL)) {
 299		lkb->lkb_flags &= ~DLM_IFL_TIMEOUT_CANCEL;
 300		rv = -ETIMEDOUT;
 301	}
 302
 303	if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_DEADLOCK_CANCEL)) {
 304		lkb->lkb_flags &= ~DLM_IFL_DEADLOCK_CANCEL;
 305		rv = -EDEADLK;
 306	}
 307
 308	dlm_add_cb(lkb, DLM_CB_CAST, lkb->lkb_grmode, rv, lkb->lkb_sbflags);
 309}
 310
 311static inline void queue_cast_overlap(struct dlm_rsb *r, struct dlm_lkb *lkb)
 312{
 313	queue_cast(r, lkb,
 314		   is_overlap_unlock(lkb) ? -DLM_EUNLOCK : -DLM_ECANCEL);
 315}
 316
 317static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode)
 318{
 319	if (is_master_copy(lkb)) {
 320		send_bast(r, lkb, rqmode);
 321	} else {
 322		dlm_add_cb(lkb, DLM_CB_BAST, rqmode, 0, 0);
 323	}
 324}
 325
 326/*
 327 * Basic operations on rsb's and lkb's
 328 */
 329
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 330static int pre_rsb_struct(struct dlm_ls *ls)
 331{
 332	struct dlm_rsb *r1, *r2;
 333	int count = 0;
 334
 335	spin_lock(&ls->ls_new_rsb_spin);
 336	if (ls->ls_new_rsb_count > dlm_config.ci_new_rsb_count / 2) {
 337		spin_unlock(&ls->ls_new_rsb_spin);
 338		return 0;
 339	}
 340	spin_unlock(&ls->ls_new_rsb_spin);
 341
 342	r1 = dlm_allocate_rsb(ls);
 343	r2 = dlm_allocate_rsb(ls);
 344
 345	spin_lock(&ls->ls_new_rsb_spin);
 346	if (r1) {
 347		list_add(&r1->res_hashchain, &ls->ls_new_rsb);
 348		ls->ls_new_rsb_count++;
 349	}
 350	if (r2) {
 351		list_add(&r2->res_hashchain, &ls->ls_new_rsb);
 352		ls->ls_new_rsb_count++;
 353	}
 354	count = ls->ls_new_rsb_count;
 355	spin_unlock(&ls->ls_new_rsb_spin);
 356
 357	if (!count)
 358		return -ENOMEM;
 359	return 0;
 360}
 361
 362/* If ls->ls_new_rsb is empty, return -EAGAIN, so the caller can
 363   unlock any spinlocks, go back and call pre_rsb_struct again.
 364   Otherwise, take an rsb off the list and return it. */
 365
 366static int get_rsb_struct(struct dlm_ls *ls, char *name, int len,
 367			  struct dlm_rsb **r_ret)
 368{
 369	struct dlm_rsb *r;
 370	int count;
 371
 372	spin_lock(&ls->ls_new_rsb_spin);
 373	if (list_empty(&ls->ls_new_rsb)) {
 374		count = ls->ls_new_rsb_count;
 375		spin_unlock(&ls->ls_new_rsb_spin);
 376		log_debug(ls, "find_rsb retry %d %d %s",
 377			  count, dlm_config.ci_new_rsb_count, name);
 378		return -EAGAIN;
 379	}
 380
 381	r = list_first_entry(&ls->ls_new_rsb, struct dlm_rsb, res_hashchain);
 382	list_del(&r->res_hashchain);
 
 
 383	ls->ls_new_rsb_count--;
 384	spin_unlock(&ls->ls_new_rsb_spin);
 385
 386	r->res_ls = ls;
 387	r->res_length = len;
 388	memcpy(r->res_name, name, len);
 389	mutex_init(&r->res_mutex);
 390
 391	INIT_LIST_HEAD(&r->res_hashchain);
 392	INIT_LIST_HEAD(&r->res_lookup);
 393	INIT_LIST_HEAD(&r->res_grantqueue);
 394	INIT_LIST_HEAD(&r->res_convertqueue);
 395	INIT_LIST_HEAD(&r->res_waitqueue);
 396	INIT_LIST_HEAD(&r->res_root_list);
 397	INIT_LIST_HEAD(&r->res_recover_list);
 398
 399	*r_ret = r;
 400	return 0;
 401}
 402
 403static int search_rsb_list(struct list_head *head, char *name, int len,
 404			   unsigned int flags, struct dlm_rsb **r_ret)
 
 
 
 
 
 
 
 
 
 405{
 
 406	struct dlm_rsb *r;
 407	int error = 0;
 408
 409	list_for_each_entry(r, head, res_hashchain) {
 410		if (len == r->res_length && !memcmp(name, r->res_name, len))
 
 
 
 
 
 
 411			goto found;
 412	}
 413	*r_ret = NULL;
 414	return -EBADR;
 415
 416 found:
 417	if (r->res_nodeid && (flags & R_MASTER))
 418		error = -ENOTBLK;
 419	*r_ret = r;
 420	return error;
 421}
 422
 423static int _search_rsb(struct dlm_ls *ls, char *name, int len, int b,
 424		       unsigned int flags, struct dlm_rsb **r_ret)
 425{
 426	struct dlm_rsb *r;
 427	int error;
 428
 429	error = search_rsb_list(&ls->ls_rsbtbl[b].list, name, len, flags, &r);
 430	if (!error) {
 431		kref_get(&r->res_ref);
 432		goto out;
 
 
 
 
 
 
 
 
 
 
 
 
 
 433	}
 434	error = search_rsb_list(&ls->ls_rsbtbl[b].toss, name, len, flags, &r);
 435	if (error)
 436		goto out;
 437
 438	list_move(&r->res_hashchain, &ls->ls_rsbtbl[b].list);
 439
 440	if (dlm_no_directory(ls))
 441		goto out;
 442
 443	if (r->res_nodeid == -1) {
 444		rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
 445		r->res_first_lkid = 0;
 446	} else if (r->res_nodeid > 0) {
 447		rsb_set_flag(r, RSB_MASTER_UNCERTAIN);
 448		r->res_first_lkid = 0;
 449	} else {
 450		DLM_ASSERT(r->res_nodeid == 0, dlm_print_rsb(r););
 451		DLM_ASSERT(!rsb_flag(r, RSB_MASTER_UNCERTAIN),);
 452	}
 453 out:
 454	*r_ret = r;
 455	return error;
 456}
 457
 458/*
 459 * Find rsb in rsbtbl and potentially create/add one
 460 *
 461 * Delaying the release of rsb's has a similar benefit to applications keeping
 462 * NL locks on an rsb, but without the guarantee that the cached master value
 463 * will still be valid when the rsb is reused.  Apps aren't always smart enough
 464 * to keep NL locks on an rsb that they may lock again shortly; this can lead
 465 * to excessive master lookups and removals if we don't delay the release.
 466 *
 467 * Searching for an rsb means looking through both the normal list and toss
 468 * list.  When found on the toss list the rsb is moved to the normal list with
 469 * ref count of 1; when found on normal list the ref count is incremented.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 470 */
 471
 472static int find_rsb(struct dlm_ls *ls, char *name, int namelen,
 473		    unsigned int flags, struct dlm_rsb **r_ret)
 
 
 474{
 475	struct dlm_rsb *r = NULL;
 476	uint32_t hash, bucket;
 
 
 
 
 477	int error;
 478
 479	if (namelen > DLM_RESNAME_MAXLEN) {
 480		error = -EINVAL;
 481		goto out;
 
 
 
 
 482	}
 483
 484	if (dlm_no_directory(ls))
 485		flags |= R_CREATE;
 
 
 
 
 
 
 
 
 
 
 
 
 486
 487	hash = jhash(name, namelen, 0);
 488	bucket = hash & (ls->ls_rsbtbl_size - 1);
 
 
 489
 490 retry:
 491	if (flags & R_CREATE) {
 492		error = pre_rsb_struct(ls);
 493		if (error < 0)
 494			goto out;
 495	}
 496
 497	spin_lock(&ls->ls_rsbtbl[bucket].lock);
 
 
 
 
 
 
 
 
 
 
 
 
 498
 499	error = _search_rsb(ls, name, namelen, bucket, flags, &r);
 500	if (!error)
 501		goto out_unlock;
 502
 503	if (error == -EBADR && !(flags & R_CREATE))
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 504		goto out_unlock;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 505
 506	/* the rsb was found but wasn't a master copy */
 507	if (error == -ENOTBLK)
 
 
 
 
 508		goto out_unlock;
 509
 510	error = get_rsb_struct(ls, name, namelen, &r);
 511	if (error == -EAGAIN) {
 512		spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 513		goto retry;
 514	}
 515	if (error)
 516		goto out_unlock;
 517
 518	r->res_hash = hash;
 519	r->res_bucket = bucket;
 520	r->res_nodeid = -1;
 521	kref_init(&r->res_ref);
 522
 523	/* With no directory, the master can be set immediately */
 524	if (dlm_no_directory(ls)) {
 525		int nodeid = dlm_dir_nodeid(r);
 526		if (nodeid == dlm_our_nodeid())
 527			nodeid = 0;
 528		r->res_nodeid = nodeid;
 
 529	}
 530	list_add(&r->res_hashchain, &ls->ls_rsbtbl[bucket].list);
 531	error = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 532 out_unlock:
 533	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 534 out:
 535	*r_ret = r;
 536	return error;
 537}
 538
 539/* This is only called to add a reference when the code already holds
 540   a valid reference to the rsb, so there's no need for locking. */
 541
 542static inline void hold_rsb(struct dlm_rsb *r)
 
 
 
 
 543{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 544	kref_get(&r->res_ref);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 545}
 546
 547void dlm_hold_rsb(struct dlm_rsb *r)
 
 548{
 549	hold_rsb(r);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 550}
 551
 552static void toss_rsb(struct kref *kref)
 
 
 
 
 553{
 554	struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
 555	struct dlm_ls *ls = r->res_ls;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 556
 557	DLM_ASSERT(list_empty(&r->res_root_list), dlm_print_rsb(r););
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 558	kref_init(&r->res_ref);
 559	list_move(&r->res_hashchain, &ls->ls_rsbtbl[r->res_bucket].toss);
 560	r->res_toss_time = jiffies;
 561	if (r->res_lvbptr) {
 562		dlm_free_lvb(r->res_lvbptr);
 563		r->res_lvbptr = NULL;
 
 
 
 
 564	}
 
 
 
 
 
 
 
 
 565}
 566
 567/* When all references to the rsb are gone it's transferred to
 568   the tossed list for later disposal. */
 
 
 
 569
 570static void put_rsb(struct dlm_rsb *r)
 
 
 
 
 
 
 
 
 
 
 
 571{
 572	struct dlm_ls *ls = r->res_ls;
 573	uint32_t bucket = r->res_bucket;
 
 574
 575	spin_lock(&ls->ls_rsbtbl[bucket].lock);
 576	kref_put(&r->res_ref, toss_rsb);
 577	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 
 
 
 
 
 
 
 
 
 
 
 
 578}
 579
 580void dlm_put_rsb(struct dlm_rsb *r)
 581{
 582	put_rsb(r);
 
 
 
 
 
 
 
 
 
 
 
 
 583}
 584
 585/* See comment for unhold_lkb */
 586
 587static void unhold_rsb(struct dlm_rsb *r)
 588{
 589	int rv;
 590	rv = kref_put(&r->res_ref, toss_rsb);
 591	DLM_ASSERT(!rv, dlm_dump_rsb(r););
 592}
 593
 594static void kill_rsb(struct kref *kref)
 595{
 596	struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
 597
 598	/* All work is done after the return from kref_put() so we
 599	   can release the write_lock before the remove and free. */
 600
 601	DLM_ASSERT(list_empty(&r->res_lookup), dlm_dump_rsb(r););
 602	DLM_ASSERT(list_empty(&r->res_grantqueue), dlm_dump_rsb(r););
 603	DLM_ASSERT(list_empty(&r->res_convertqueue), dlm_dump_rsb(r););
 604	DLM_ASSERT(list_empty(&r->res_waitqueue), dlm_dump_rsb(r););
 605	DLM_ASSERT(list_empty(&r->res_root_list), dlm_dump_rsb(r););
 606	DLM_ASSERT(list_empty(&r->res_recover_list), dlm_dump_rsb(r););
 607}
 608
 609/* Attaching/detaching lkb's from rsb's is for rsb reference counting.
 610   The rsb must exist as long as any lkb's for it do. */
 611
 612static void attach_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
 613{
 614	hold_rsb(r);
 615	lkb->lkb_resource = r;
 616}
 617
 618static void detach_lkb(struct dlm_lkb *lkb)
 619{
 620	if (lkb->lkb_resource) {
 621		put_rsb(lkb->lkb_resource);
 622		lkb->lkb_resource = NULL;
 623	}
 624}
 625
 626static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
 627{
 628	struct dlm_lkb *lkb;
 629	int rv, id;
 630
 631	lkb = dlm_allocate_lkb(ls);
 632	if (!lkb)
 633		return -ENOMEM;
 634
 635	lkb->lkb_nodeid = -1;
 636	lkb->lkb_grmode = DLM_LOCK_IV;
 637	kref_init(&lkb->lkb_ref);
 638	INIT_LIST_HEAD(&lkb->lkb_ownqueue);
 639	INIT_LIST_HEAD(&lkb->lkb_rsb_lookup);
 640	INIT_LIST_HEAD(&lkb->lkb_time_list);
 641	INIT_LIST_HEAD(&lkb->lkb_cb_list);
 642	mutex_init(&lkb->lkb_cb_mutex);
 643	INIT_WORK(&lkb->lkb_cb_work, dlm_callback_work);
 644
 645 retry:
 646	rv = idr_pre_get(&ls->ls_lkbidr, GFP_NOFS);
 647	if (!rv)
 648		return -ENOMEM;
 649
 650	spin_lock(&ls->ls_lkbidr_spin);
 651	rv = idr_get_new_above(&ls->ls_lkbidr, lkb, 1, &id);
 652	if (!rv)
 653		lkb->lkb_id = id;
 654	spin_unlock(&ls->ls_lkbidr_spin);
 655
 656	if (rv == -EAGAIN)
 657		goto retry;
 658
 659	if (rv < 0) {
 660		log_error(ls, "create_lkb idr error %d", rv);
 
 661		return rv;
 662	}
 663
 664	*lkb_ret = lkb;
 665	return 0;
 666}
 667
 668static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret)
 669{
 670	struct dlm_lkb *lkb;
 671
 672	spin_lock(&ls->ls_lkbidr_spin);
 673	lkb = idr_find(&ls->ls_lkbidr, lkid);
 674	if (lkb)
 675		kref_get(&lkb->lkb_ref);
 676	spin_unlock(&ls->ls_lkbidr_spin);
 677
 678	*lkb_ret = lkb;
 679	return lkb ? 0 : -ENOENT;
 680}
 681
 682static void kill_lkb(struct kref *kref)
 683{
 684	struct dlm_lkb *lkb = container_of(kref, struct dlm_lkb, lkb_ref);
 685
 686	/* All work is done after the return from kref_put() so we
 687	   can release the write_lock before the detach_lkb */
 688
 689	DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
 690}
 691
 692/* __put_lkb() is used when an lkb may not have an rsb attached to
 693   it so we need to provide the lockspace explicitly */
 694
 695static int __put_lkb(struct dlm_ls *ls, struct dlm_lkb *lkb)
 696{
 697	uint32_t lkid = lkb->lkb_id;
 698
 699	spin_lock(&ls->ls_lkbidr_spin);
 700	if (kref_put(&lkb->lkb_ref, kill_lkb)) {
 701		idr_remove(&ls->ls_lkbidr, lkid);
 702		spin_unlock(&ls->ls_lkbidr_spin);
 703
 704		detach_lkb(lkb);
 705
 706		/* for local/process lkbs, lvbptr points to caller's lksb */
 707		if (lkb->lkb_lvbptr && is_master_copy(lkb))
 708			dlm_free_lvb(lkb->lkb_lvbptr);
 709		dlm_free_lkb(lkb);
 710		return 1;
 711	} else {
 712		spin_unlock(&ls->ls_lkbidr_spin);
 713		return 0;
 714	}
 715}
 716
 717int dlm_put_lkb(struct dlm_lkb *lkb)
 718{
 719	struct dlm_ls *ls;
 720
 721	DLM_ASSERT(lkb->lkb_resource, dlm_print_lkb(lkb););
 722	DLM_ASSERT(lkb->lkb_resource->res_ls, dlm_print_lkb(lkb););
 723
 724	ls = lkb->lkb_resource->res_ls;
 725	return __put_lkb(ls, lkb);
 726}
 727
 728/* This is only called to add a reference when the code already holds
 729   a valid reference to the lkb, so there's no need for locking. */
 730
 731static inline void hold_lkb(struct dlm_lkb *lkb)
 732{
 733	kref_get(&lkb->lkb_ref);
 734}
 735
 736/* This is called when we need to remove a reference and are certain
 737   it's not the last ref.  e.g. del_lkb is always called between a
 738   find_lkb/put_lkb and is always the inverse of a previous add_lkb.
 739   put_lkb would work fine, but would involve unnecessary locking */
 740
 741static inline void unhold_lkb(struct dlm_lkb *lkb)
 742{
 743	int rv;
 744	rv = kref_put(&lkb->lkb_ref, kill_lkb);
 745	DLM_ASSERT(!rv, dlm_print_lkb(lkb););
 746}
 747
 748static void lkb_add_ordered(struct list_head *new, struct list_head *head,
 749			    int mode)
 750{
 751	struct dlm_lkb *lkb = NULL;
 752
 753	list_for_each_entry(lkb, head, lkb_statequeue)
 754		if (lkb->lkb_rqmode < mode)
 755			break;
 756
 757	__list_add(new, lkb->lkb_statequeue.prev, &lkb->lkb_statequeue);
 758}
 759
 760/* add/remove lkb to rsb's grant/convert/wait queue */
 761
 762static void add_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int status)
 763{
 764	kref_get(&lkb->lkb_ref);
 765
 766	DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
 767
 768	lkb->lkb_timestamp = ktime_get();
 769
 770	lkb->lkb_status = status;
 771
 772	switch (status) {
 773	case DLM_LKSTS_WAITING:
 774		if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
 775			list_add(&lkb->lkb_statequeue, &r->res_waitqueue);
 776		else
 777			list_add_tail(&lkb->lkb_statequeue, &r->res_waitqueue);
 778		break;
 779	case DLM_LKSTS_GRANTED:
 780		/* convention says granted locks kept in order of grmode */
 781		lkb_add_ordered(&lkb->lkb_statequeue, &r->res_grantqueue,
 782				lkb->lkb_grmode);
 783		break;
 784	case DLM_LKSTS_CONVERT:
 785		if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
 786			list_add(&lkb->lkb_statequeue, &r->res_convertqueue);
 787		else
 788			list_add_tail(&lkb->lkb_statequeue,
 789				      &r->res_convertqueue);
 790		break;
 791	default:
 792		DLM_ASSERT(0, dlm_print_lkb(lkb); printk("sts=%d\n", status););
 793	}
 794}
 795
 796static void del_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
 797{
 798	lkb->lkb_status = 0;
 799	list_del(&lkb->lkb_statequeue);
 800	unhold_lkb(lkb);
 801}
 802
 803static void move_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int sts)
 804{
 805	hold_lkb(lkb);
 806	del_lkb(r, lkb);
 807	add_lkb(r, lkb, sts);
 808	unhold_lkb(lkb);
 809}
 810
 811static int msg_reply_type(int mstype)
 812{
 813	switch (mstype) {
 814	case DLM_MSG_REQUEST:
 815		return DLM_MSG_REQUEST_REPLY;
 816	case DLM_MSG_CONVERT:
 817		return DLM_MSG_CONVERT_REPLY;
 818	case DLM_MSG_UNLOCK:
 819		return DLM_MSG_UNLOCK_REPLY;
 820	case DLM_MSG_CANCEL:
 821		return DLM_MSG_CANCEL_REPLY;
 822	case DLM_MSG_LOOKUP:
 823		return DLM_MSG_LOOKUP_REPLY;
 824	}
 825	return -1;
 826}
 827
 828static int nodeid_warned(int nodeid, int num_nodes, int *warned)
 829{
 830	int i;
 831
 832	for (i = 0; i < num_nodes; i++) {
 833		if (!warned[i]) {
 834			warned[i] = nodeid;
 835			return 0;
 836		}
 837		if (warned[i] == nodeid)
 838			return 1;
 839	}
 840	return 0;
 841}
 842
 843void dlm_scan_waiters(struct dlm_ls *ls)
 844{
 845	struct dlm_lkb *lkb;
 846	ktime_t zero = ktime_set(0, 0);
 847	s64 us;
 848	s64 debug_maxus = 0;
 849	u32 debug_scanned = 0;
 850	u32 debug_expired = 0;
 851	int num_nodes = 0;
 852	int *warned = NULL;
 853
 854	if (!dlm_config.ci_waitwarn_us)
 855		return;
 856
 857	mutex_lock(&ls->ls_waiters_mutex);
 858
 859	list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
 860		if (ktime_equal(lkb->lkb_wait_time, zero))
 861			continue;
 862
 863		debug_scanned++;
 864
 865		us = ktime_to_us(ktime_sub(ktime_get(), lkb->lkb_wait_time));
 866
 867		if (us < dlm_config.ci_waitwarn_us)
 868			continue;
 869
 870		lkb->lkb_wait_time = zero;
 871
 872		debug_expired++;
 873		if (us > debug_maxus)
 874			debug_maxus = us;
 875
 876		if (!num_nodes) {
 877			num_nodes = ls->ls_num_nodes;
 878			warned = kzalloc(num_nodes * sizeof(int), GFP_KERNEL);
 879		}
 880		if (!warned)
 881			continue;
 882		if (nodeid_warned(lkb->lkb_wait_nodeid, num_nodes, warned))
 883			continue;
 884
 885		log_error(ls, "waitwarn %x %lld %d us check connection to "
 886			  "node %d", lkb->lkb_id, (long long)us,
 887			  dlm_config.ci_waitwarn_us, lkb->lkb_wait_nodeid);
 888	}
 889	mutex_unlock(&ls->ls_waiters_mutex);
 890	kfree(warned);
 891
 892	if (debug_expired)
 893		log_debug(ls, "scan_waiters %u warn %u over %d us max %lld us",
 894			  debug_scanned, debug_expired,
 895			  dlm_config.ci_waitwarn_us, (long long)debug_maxus);
 896}
 897
 898/* add/remove lkb from global waiters list of lkb's waiting for
 899   a reply from a remote node */
 900
 901static int add_to_waiters(struct dlm_lkb *lkb, int mstype, int to_nodeid)
 902{
 903	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
 904	int error = 0;
 905
 906	mutex_lock(&ls->ls_waiters_mutex);
 907
 908	if (is_overlap_unlock(lkb) ||
 909	    (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL))) {
 910		error = -EINVAL;
 911		goto out;
 912	}
 913
 914	if (lkb->lkb_wait_type || is_overlap_cancel(lkb)) {
 915		switch (mstype) {
 916		case DLM_MSG_UNLOCK:
 917			lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
 918			break;
 919		case DLM_MSG_CANCEL:
 920			lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
 921			break;
 922		default:
 923			error = -EBUSY;
 924			goto out;
 925		}
 926		lkb->lkb_wait_count++;
 927		hold_lkb(lkb);
 928
 929		log_debug(ls, "addwait %x cur %d overlap %d count %d f %x",
 930			  lkb->lkb_id, lkb->lkb_wait_type, mstype,
 931			  lkb->lkb_wait_count, lkb->lkb_flags);
 932		goto out;
 933	}
 934
 935	DLM_ASSERT(!lkb->lkb_wait_count,
 936		   dlm_print_lkb(lkb);
 937		   printk("wait_count %d\n", lkb->lkb_wait_count););
 938
 939	lkb->lkb_wait_count++;
 940	lkb->lkb_wait_type = mstype;
 941	lkb->lkb_wait_time = ktime_get();
 942	lkb->lkb_wait_nodeid = to_nodeid; /* for debugging */
 943	hold_lkb(lkb);
 944	list_add(&lkb->lkb_wait_reply, &ls->ls_waiters);
 945 out:
 946	if (error)
 947		log_error(ls, "addwait error %x %d flags %x %d %d %s",
 948			  lkb->lkb_id, error, lkb->lkb_flags, mstype,
 949			  lkb->lkb_wait_type, lkb->lkb_resource->res_name);
 950	mutex_unlock(&ls->ls_waiters_mutex);
 951	return error;
 952}
 953
 954/* We clear the RESEND flag because we might be taking an lkb off the waiters
 955   list as part of process_requestqueue (e.g. a lookup that has an optimized
 956   request reply on the requestqueue) between dlm_recover_waiters_pre() which
 957   set RESEND and dlm_recover_waiters_post() */
 958
 959static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype,
 960				struct dlm_message *ms)
 961{
 962	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
 963	int overlap_done = 0;
 964
 965	if (is_overlap_unlock(lkb) && (mstype == DLM_MSG_UNLOCK_REPLY)) {
 966		log_debug(ls, "remwait %x unlock_reply overlap", lkb->lkb_id);
 967		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
 968		overlap_done = 1;
 969		goto out_del;
 970	}
 971
 972	if (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL_REPLY)) {
 973		log_debug(ls, "remwait %x cancel_reply overlap", lkb->lkb_id);
 974		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
 975		overlap_done = 1;
 976		goto out_del;
 977	}
 978
 979	/* Cancel state was preemptively cleared by a successful convert,
 980	   see next comment, nothing to do. */
 981
 982	if ((mstype == DLM_MSG_CANCEL_REPLY) &&
 983	    (lkb->lkb_wait_type != DLM_MSG_CANCEL)) {
 984		log_debug(ls, "remwait %x cancel_reply wait_type %d",
 985			  lkb->lkb_id, lkb->lkb_wait_type);
 986		return -1;
 987	}
 988
 989	/* Remove for the convert reply, and premptively remove for the
 990	   cancel reply.  A convert has been granted while there's still
 991	   an outstanding cancel on it (the cancel is moot and the result
 992	   in the cancel reply should be 0).  We preempt the cancel reply
 993	   because the app gets the convert result and then can follow up
 994	   with another op, like convert.  This subsequent op would see the
 995	   lingering state of the cancel and fail with -EBUSY. */
 996
 997	if ((mstype == DLM_MSG_CONVERT_REPLY) &&
 998	    (lkb->lkb_wait_type == DLM_MSG_CONVERT) &&
 999	    is_overlap_cancel(lkb) && ms && !ms->m_result) {
1000		log_debug(ls, "remwait %x convert_reply zap overlap_cancel",
1001			  lkb->lkb_id);
1002		lkb->lkb_wait_type = 0;
1003		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
1004		lkb->lkb_wait_count--;
1005		goto out_del;
1006	}
1007
1008	/* N.B. type of reply may not always correspond to type of original
1009	   msg due to lookup->request optimization, verify others? */
1010
1011	if (lkb->lkb_wait_type) {
1012		lkb->lkb_wait_type = 0;
1013		goto out_del;
1014	}
1015
1016	log_error(ls, "remwait error %x reply %d flags %x no wait_type",
1017		  lkb->lkb_id, mstype, lkb->lkb_flags);
 
1018	return -1;
1019
1020 out_del:
1021	/* the force-unlock/cancel has completed and we haven't recvd a reply
1022	   to the op that was in progress prior to the unlock/cancel; we
1023	   give up on any reply to the earlier op.  FIXME: not sure when/how
1024	   this would happen */
1025
1026	if (overlap_done && lkb->lkb_wait_type) {
1027		log_error(ls, "remwait error %x reply %d wait_type %d overlap",
1028			  lkb->lkb_id, mstype, lkb->lkb_wait_type);
1029		lkb->lkb_wait_count--;
1030		lkb->lkb_wait_type = 0;
1031	}
1032
1033	DLM_ASSERT(lkb->lkb_wait_count, dlm_print_lkb(lkb););
1034
1035	lkb->lkb_flags &= ~DLM_IFL_RESEND;
1036	lkb->lkb_wait_count--;
1037	if (!lkb->lkb_wait_count)
1038		list_del_init(&lkb->lkb_wait_reply);
1039	unhold_lkb(lkb);
1040	return 0;
1041}
1042
1043static int remove_from_waiters(struct dlm_lkb *lkb, int mstype)
1044{
1045	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1046	int error;
1047
1048	mutex_lock(&ls->ls_waiters_mutex);
1049	error = _remove_from_waiters(lkb, mstype, NULL);
1050	mutex_unlock(&ls->ls_waiters_mutex);
1051	return error;
1052}
1053
1054/* Handles situations where we might be processing a "fake" or "stub" reply in
1055   which we can't try to take waiters_mutex again. */
1056
1057static int remove_from_waiters_ms(struct dlm_lkb *lkb, struct dlm_message *ms)
1058{
1059	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1060	int error;
1061
1062	if (ms->m_flags != DLM_IFL_STUB_MS)
1063		mutex_lock(&ls->ls_waiters_mutex);
1064	error = _remove_from_waiters(lkb, ms->m_type, ms);
1065	if (ms->m_flags != DLM_IFL_STUB_MS)
1066		mutex_unlock(&ls->ls_waiters_mutex);
1067	return error;
1068}
1069
1070static void dir_remove(struct dlm_rsb *r)
 
 
 
 
 
1071{
1072	int to_nodeid;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1073
1074	if (dlm_no_directory(r->res_ls))
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1075		return;
 
1076
1077	to_nodeid = dlm_dir_nodeid(r);
1078	if (to_nodeid != dlm_our_nodeid())
1079		send_remove(r);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1080	else
1081		dlm_dir_remove_entry(r->res_ls, to_nodeid,
1082				     r->res_name, r->res_length);
1083}
1084
1085/* FIXME: shouldn't this be able to exit as soon as one non-due rsb is
1086   found since they are in order of newest to oldest? */
 
 
 
 
 
 
 
 
 
 
 
1087
1088static int shrink_bucket(struct dlm_ls *ls, int b)
1089{
1090	struct dlm_rsb *r;
1091	int count = 0, found;
1092
1093	for (;;) {
1094		found = 0;
1095		spin_lock(&ls->ls_rsbtbl[b].lock);
1096		list_for_each_entry_reverse(r, &ls->ls_rsbtbl[b].toss,
1097					    res_hashchain) {
1098			if (!time_after_eq(jiffies, r->res_toss_time +
1099					   dlm_config.ci_toss_secs * HZ))
1100				continue;
1101			found = 1;
1102			break;
1103		}
1104
1105		if (!found) {
1106			spin_unlock(&ls->ls_rsbtbl[b].lock);
1107			break;
 
 
 
1108		}
1109
1110		if (kref_put(&r->res_ref, kill_rsb)) {
1111			list_del(&r->res_hashchain);
1112			spin_unlock(&ls->ls_rsbtbl[b].lock);
 
 
 
 
 
1113
1114			if (is_master(r))
1115				dir_remove(r);
1116			dlm_free_rsb(r);
1117			count++;
1118		} else {
1119			spin_unlock(&ls->ls_rsbtbl[b].lock);
1120			log_error(ls, "tossed rsb in use %s", r->res_name);
 
 
1121		}
1122	}
1123
1124	return count;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1125}
1126
1127void dlm_scan_rsbs(struct dlm_ls *ls)
1128{
1129	int i;
1130
1131	for (i = 0; i < ls->ls_rsbtbl_size; i++) {
1132		shrink_bucket(ls, i);
1133		if (dlm_locking_stopped(ls))
1134			break;
1135		cond_resched();
1136	}
1137}
1138
1139static void add_timeout(struct dlm_lkb *lkb)
1140{
1141	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1142
1143	if (is_master_copy(lkb))
1144		return;
1145
1146	if (test_bit(LSFL_TIMEWARN, &ls->ls_flags) &&
1147	    !(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
1148		lkb->lkb_flags |= DLM_IFL_WATCH_TIMEWARN;
1149		goto add_it;
1150	}
1151	if (lkb->lkb_exflags & DLM_LKF_TIMEOUT)
1152		goto add_it;
1153	return;
1154
1155 add_it:
1156	DLM_ASSERT(list_empty(&lkb->lkb_time_list), dlm_print_lkb(lkb););
1157	mutex_lock(&ls->ls_timeout_mutex);
1158	hold_lkb(lkb);
1159	list_add_tail(&lkb->lkb_time_list, &ls->ls_timeout);
1160	mutex_unlock(&ls->ls_timeout_mutex);
1161}
1162
1163static void del_timeout(struct dlm_lkb *lkb)
1164{
1165	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1166
1167	mutex_lock(&ls->ls_timeout_mutex);
1168	if (!list_empty(&lkb->lkb_time_list)) {
1169		list_del_init(&lkb->lkb_time_list);
1170		unhold_lkb(lkb);
1171	}
1172	mutex_unlock(&ls->ls_timeout_mutex);
1173}
1174
1175/* FIXME: is it safe to look at lkb_exflags, lkb_flags, lkb_timestamp, and
1176   lkb_lksb_timeout without lock_rsb?  Note: we can't lock timeout_mutex
1177   and then lock rsb because of lock ordering in add_timeout.  We may need
1178   to specify some special timeout-related bits in the lkb that are just to
1179   be accessed under the timeout_mutex. */
1180
1181void dlm_scan_timeout(struct dlm_ls *ls)
1182{
1183	struct dlm_rsb *r;
1184	struct dlm_lkb *lkb;
1185	int do_cancel, do_warn;
1186	s64 wait_us;
1187
1188	for (;;) {
1189		if (dlm_locking_stopped(ls))
1190			break;
1191
1192		do_cancel = 0;
1193		do_warn = 0;
1194		mutex_lock(&ls->ls_timeout_mutex);
1195		list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list) {
1196
1197			wait_us = ktime_to_us(ktime_sub(ktime_get(),
1198					      		lkb->lkb_timestamp));
1199
1200			if ((lkb->lkb_exflags & DLM_LKF_TIMEOUT) &&
1201			    wait_us >= (lkb->lkb_timeout_cs * 10000))
1202				do_cancel = 1;
1203
1204			if ((lkb->lkb_flags & DLM_IFL_WATCH_TIMEWARN) &&
1205			    wait_us >= dlm_config.ci_timewarn_cs * 10000)
1206				do_warn = 1;
1207
1208			if (!do_cancel && !do_warn)
1209				continue;
1210			hold_lkb(lkb);
1211			break;
1212		}
1213		mutex_unlock(&ls->ls_timeout_mutex);
1214
1215		if (!do_cancel && !do_warn)
1216			break;
1217
1218		r = lkb->lkb_resource;
1219		hold_rsb(r);
1220		lock_rsb(r);
1221
1222		if (do_warn) {
1223			/* clear flag so we only warn once */
1224			lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
1225			if (!(lkb->lkb_exflags & DLM_LKF_TIMEOUT))
1226				del_timeout(lkb);
1227			dlm_timeout_warn(lkb);
1228		}
1229
1230		if (do_cancel) {
1231			log_debug(ls, "timeout cancel %x node %d %s",
1232				  lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
1233			lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
1234			lkb->lkb_flags |= DLM_IFL_TIMEOUT_CANCEL;
1235			del_timeout(lkb);
1236			_cancel_lock(r, lkb);
1237		}
1238
1239		unlock_rsb(r);
1240		unhold_rsb(r);
1241		dlm_put_lkb(lkb);
1242	}
1243}
1244
1245/* This is only called by dlm_recoverd, and we rely on dlm_ls_stop() stopping
1246   dlm_recoverd before checking/setting ls_recover_begin. */
1247
1248void dlm_adjust_timeouts(struct dlm_ls *ls)
1249{
1250	struct dlm_lkb *lkb;
1251	u64 adj_us = jiffies_to_usecs(jiffies - ls->ls_recover_begin);
1252
1253	ls->ls_recover_begin = 0;
1254	mutex_lock(&ls->ls_timeout_mutex);
1255	list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list)
1256		lkb->lkb_timestamp = ktime_add_us(lkb->lkb_timestamp, adj_us);
1257	mutex_unlock(&ls->ls_timeout_mutex);
1258
1259	if (!dlm_config.ci_waitwarn_us)
1260		return;
1261
1262	mutex_lock(&ls->ls_waiters_mutex);
1263	list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
1264		if (ktime_to_us(lkb->lkb_wait_time))
1265			lkb->lkb_wait_time = ktime_get();
1266	}
1267	mutex_unlock(&ls->ls_waiters_mutex);
1268}
1269
1270/* lkb is master or local copy */
1271
1272static void set_lvb_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1273{
1274	int b, len = r->res_ls->ls_lvblen;
1275
1276	/* b=1 lvb returned to caller
1277	   b=0 lvb written to rsb or invalidated
1278	   b=-1 do nothing */
1279
1280	b =  dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
1281
1282	if (b == 1) {
1283		if (!lkb->lkb_lvbptr)
1284			return;
1285
1286		if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1287			return;
1288
1289		if (!r->res_lvbptr)
1290			return;
1291
1292		memcpy(lkb->lkb_lvbptr, r->res_lvbptr, len);
1293		lkb->lkb_lvbseq = r->res_lvbseq;
1294
1295	} else if (b == 0) {
1296		if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
1297			rsb_set_flag(r, RSB_VALNOTVALID);
1298			return;
1299		}
1300
1301		if (!lkb->lkb_lvbptr)
1302			return;
1303
1304		if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1305			return;
1306
1307		if (!r->res_lvbptr)
1308			r->res_lvbptr = dlm_allocate_lvb(r->res_ls);
1309
1310		if (!r->res_lvbptr)
1311			return;
1312
1313		memcpy(r->res_lvbptr, lkb->lkb_lvbptr, len);
1314		r->res_lvbseq++;
1315		lkb->lkb_lvbseq = r->res_lvbseq;
1316		rsb_clear_flag(r, RSB_VALNOTVALID);
1317	}
1318
1319	if (rsb_flag(r, RSB_VALNOTVALID))
1320		lkb->lkb_sbflags |= DLM_SBF_VALNOTVALID;
1321}
1322
1323static void set_lvb_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1324{
1325	if (lkb->lkb_grmode < DLM_LOCK_PW)
1326		return;
1327
1328	if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
1329		rsb_set_flag(r, RSB_VALNOTVALID);
1330		return;
1331	}
1332
1333	if (!lkb->lkb_lvbptr)
1334		return;
1335
1336	if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1337		return;
1338
1339	if (!r->res_lvbptr)
1340		r->res_lvbptr = dlm_allocate_lvb(r->res_ls);
1341
1342	if (!r->res_lvbptr)
1343		return;
1344
1345	memcpy(r->res_lvbptr, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
1346	r->res_lvbseq++;
1347	rsb_clear_flag(r, RSB_VALNOTVALID);
1348}
1349
1350/* lkb is process copy (pc) */
1351
1352static void set_lvb_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
1353			    struct dlm_message *ms)
1354{
1355	int b;
1356
1357	if (!lkb->lkb_lvbptr)
1358		return;
1359
1360	if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1361		return;
1362
1363	b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
1364	if (b == 1) {
1365		int len = receive_extralen(ms);
1366		if (len > DLM_RESNAME_MAXLEN)
1367			len = DLM_RESNAME_MAXLEN;
1368		memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
1369		lkb->lkb_lvbseq = ms->m_lvbseq;
1370	}
1371}
1372
1373/* Manipulate lkb's on rsb's convert/granted/waiting queues
1374   remove_lock -- used for unlock, removes lkb from granted
1375   revert_lock -- used for cancel, moves lkb from convert to granted
1376   grant_lock  -- used for request and convert, adds lkb to granted or
1377                  moves lkb from convert or waiting to granted
1378
1379   Each of these is used for master or local copy lkb's.  There is
1380   also a _pc() variation used to make the corresponding change on
1381   a process copy (pc) lkb. */
1382
1383static void _remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1384{
1385	del_lkb(r, lkb);
1386	lkb->lkb_grmode = DLM_LOCK_IV;
1387	/* this unhold undoes the original ref from create_lkb()
1388	   so this leads to the lkb being freed */
1389	unhold_lkb(lkb);
1390}
1391
1392static void remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1393{
1394	set_lvb_unlock(r, lkb);
1395	_remove_lock(r, lkb);
1396}
1397
1398static void remove_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
1399{
1400	_remove_lock(r, lkb);
1401}
1402
1403/* returns: 0 did nothing
1404	    1 moved lock to granted
1405	   -1 removed lock */
1406
1407static int revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1408{
1409	int rv = 0;
1410
1411	lkb->lkb_rqmode = DLM_LOCK_IV;
1412
1413	switch (lkb->lkb_status) {
1414	case DLM_LKSTS_GRANTED:
1415		break;
1416	case DLM_LKSTS_CONVERT:
1417		move_lkb(r, lkb, DLM_LKSTS_GRANTED);
1418		rv = 1;
1419		break;
1420	case DLM_LKSTS_WAITING:
1421		del_lkb(r, lkb);
1422		lkb->lkb_grmode = DLM_LOCK_IV;
1423		/* this unhold undoes the original ref from create_lkb()
1424		   so this leads to the lkb being freed */
1425		unhold_lkb(lkb);
1426		rv = -1;
1427		break;
1428	default:
1429		log_print("invalid status for revert %d", lkb->lkb_status);
1430	}
1431	return rv;
1432}
1433
1434static int revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
1435{
1436	return revert_lock(r, lkb);
1437}
1438
1439static void _grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1440{
1441	if (lkb->lkb_grmode != lkb->lkb_rqmode) {
1442		lkb->lkb_grmode = lkb->lkb_rqmode;
1443		if (lkb->lkb_status)
1444			move_lkb(r, lkb, DLM_LKSTS_GRANTED);
1445		else
1446			add_lkb(r, lkb, DLM_LKSTS_GRANTED);
1447	}
1448
1449	lkb->lkb_rqmode = DLM_LOCK_IV;
 
1450}
1451
1452static void grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1453{
1454	set_lvb_lock(r, lkb);
1455	_grant_lock(r, lkb);
1456	lkb->lkb_highbast = 0;
1457}
1458
1459static void grant_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
1460			  struct dlm_message *ms)
1461{
1462	set_lvb_lock_pc(r, lkb, ms);
1463	_grant_lock(r, lkb);
1464}
1465
1466/* called by grant_pending_locks() which means an async grant message must
1467   be sent to the requesting node in addition to granting the lock if the
1468   lkb belongs to a remote node. */
1469
1470static void grant_lock_pending(struct dlm_rsb *r, struct dlm_lkb *lkb)
1471{
1472	grant_lock(r, lkb);
1473	if (is_master_copy(lkb))
1474		send_grant(r, lkb);
1475	else
1476		queue_cast(r, lkb, 0);
1477}
1478
1479/* The special CONVDEADLK, ALTPR and ALTCW flags allow the master to
1480   change the granted/requested modes.  We're munging things accordingly in
1481   the process copy.
1482   CONVDEADLK: our grmode may have been forced down to NL to resolve a
1483   conversion deadlock
1484   ALTPR/ALTCW: our rqmode may have been changed to PR or CW to become
1485   compatible with other granted locks */
1486
1487static void munge_demoted(struct dlm_lkb *lkb)
1488{
1489	if (lkb->lkb_rqmode == DLM_LOCK_IV || lkb->lkb_grmode == DLM_LOCK_IV) {
1490		log_print("munge_demoted %x invalid modes gr %d rq %d",
1491			  lkb->lkb_id, lkb->lkb_grmode, lkb->lkb_rqmode);
1492		return;
1493	}
1494
1495	lkb->lkb_grmode = DLM_LOCK_NL;
1496}
1497
1498static void munge_altmode(struct dlm_lkb *lkb, struct dlm_message *ms)
1499{
1500	if (ms->m_type != DLM_MSG_REQUEST_REPLY &&
1501	    ms->m_type != DLM_MSG_GRANT) {
1502		log_print("munge_altmode %x invalid reply type %d",
1503			  lkb->lkb_id, ms->m_type);
1504		return;
1505	}
1506
1507	if (lkb->lkb_exflags & DLM_LKF_ALTPR)
1508		lkb->lkb_rqmode = DLM_LOCK_PR;
1509	else if (lkb->lkb_exflags & DLM_LKF_ALTCW)
1510		lkb->lkb_rqmode = DLM_LOCK_CW;
1511	else {
1512		log_print("munge_altmode invalid exflags %x", lkb->lkb_exflags);
1513		dlm_print_lkb(lkb);
1514	}
1515}
1516
1517static inline int first_in_list(struct dlm_lkb *lkb, struct list_head *head)
1518{
1519	struct dlm_lkb *first = list_entry(head->next, struct dlm_lkb,
1520					   lkb_statequeue);
1521	if (lkb->lkb_id == first->lkb_id)
1522		return 1;
1523
1524	return 0;
1525}
1526
1527/* Check if the given lkb conflicts with another lkb on the queue. */
1528
1529static int queue_conflict(struct list_head *head, struct dlm_lkb *lkb)
1530{
1531	struct dlm_lkb *this;
1532
1533	list_for_each_entry(this, head, lkb_statequeue) {
1534		if (this == lkb)
1535			continue;
1536		if (!modes_compat(this, lkb))
1537			return 1;
1538	}
1539	return 0;
1540}
1541
1542/*
1543 * "A conversion deadlock arises with a pair of lock requests in the converting
1544 * queue for one resource.  The granted mode of each lock blocks the requested
1545 * mode of the other lock."
1546 *
1547 * Part 2: if the granted mode of lkb is preventing an earlier lkb in the
1548 * convert queue from being granted, then deadlk/demote lkb.
1549 *
1550 * Example:
1551 * Granted Queue: empty
1552 * Convert Queue: NL->EX (first lock)
1553 *                PR->EX (second lock)
1554 *
1555 * The first lock can't be granted because of the granted mode of the second
1556 * lock and the second lock can't be granted because it's not first in the
1557 * list.  We either cancel lkb's conversion (PR->EX) and return EDEADLK, or we
1558 * demote the granted mode of lkb (from PR to NL) if it has the CONVDEADLK
1559 * flag set and return DEMOTED in the lksb flags.
1560 *
1561 * Originally, this function detected conv-deadlk in a more limited scope:
1562 * - if !modes_compat(lkb1, lkb2) && !modes_compat(lkb2, lkb1), or
1563 * - if lkb1 was the first entry in the queue (not just earlier), and was
1564 *   blocked by the granted mode of lkb2, and there was nothing on the
1565 *   granted queue preventing lkb1 from being granted immediately, i.e.
1566 *   lkb2 was the only thing preventing lkb1 from being granted.
1567 *
1568 * That second condition meant we'd only say there was conv-deadlk if
1569 * resolving it (by demotion) would lead to the first lock on the convert
1570 * queue being granted right away.  It allowed conversion deadlocks to exist
1571 * between locks on the convert queue while they couldn't be granted anyway.
1572 *
1573 * Now, we detect and take action on conversion deadlocks immediately when
1574 * they're created, even if they may not be immediately consequential.  If
1575 * lkb1 exists anywhere in the convert queue and lkb2 comes in with a granted
1576 * mode that would prevent lkb1's conversion from being granted, we do a
1577 * deadlk/demote on lkb2 right away and don't let it onto the convert queue.
1578 * I think this means that the lkb_is_ahead condition below should always
1579 * be zero, i.e. there will never be conv-deadlk between two locks that are
1580 * both already on the convert queue.
1581 */
1582
1583static int conversion_deadlock_detect(struct dlm_rsb *r, struct dlm_lkb *lkb2)
1584{
1585	struct dlm_lkb *lkb1;
1586	int lkb_is_ahead = 0;
1587
1588	list_for_each_entry(lkb1, &r->res_convertqueue, lkb_statequeue) {
1589		if (lkb1 == lkb2) {
1590			lkb_is_ahead = 1;
1591			continue;
1592		}
1593
1594		if (!lkb_is_ahead) {
1595			if (!modes_compat(lkb2, lkb1))
1596				return 1;
1597		} else {
1598			if (!modes_compat(lkb2, lkb1) &&
1599			    !modes_compat(lkb1, lkb2))
1600				return 1;
1601		}
1602	}
1603	return 0;
1604}
1605
1606/*
1607 * Return 1 if the lock can be granted, 0 otherwise.
1608 * Also detect and resolve conversion deadlocks.
1609 *
1610 * lkb is the lock to be granted
1611 *
1612 * now is 1 if the function is being called in the context of the
1613 * immediate request, it is 0 if called later, after the lock has been
1614 * queued.
1615 *
 
 
 
1616 * References are from chapter 6 of "VAXcluster Principles" by Roy Davis
1617 */
1618
1619static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now)
 
1620{
1621	int8_t conv = (lkb->lkb_grmode != DLM_LOCK_IV);
1622
1623	/*
1624	 * 6-10: Version 5.4 introduced an option to address the phenomenon of
1625	 * a new request for a NL mode lock being blocked.
1626	 *
1627	 * 6-11: If the optional EXPEDITE flag is used with the new NL mode
1628	 * request, then it would be granted.  In essence, the use of this flag
1629	 * tells the Lock Manager to expedite theis request by not considering
1630	 * what may be in the CONVERTING or WAITING queues...  As of this
1631	 * writing, the EXPEDITE flag can be used only with new requests for NL
1632	 * mode locks.  This flag is not valid for conversion requests.
1633	 *
1634	 * A shortcut.  Earlier checks return an error if EXPEDITE is used in a
1635	 * conversion or used with a non-NL requested mode.  We also know an
1636	 * EXPEDITE request is always granted immediately, so now must always
1637	 * be 1.  The full condition to grant an expedite request: (now &&
1638	 * !conv && lkb->rqmode == DLM_LOCK_NL && (flags & EXPEDITE)) can
1639	 * therefore be shortened to just checking the flag.
1640	 */
1641
1642	if (lkb->lkb_exflags & DLM_LKF_EXPEDITE)
1643		return 1;
1644
1645	/*
1646	 * A shortcut. Without this, !queue_conflict(grantqueue, lkb) would be
1647	 * added to the remaining conditions.
1648	 */
1649
1650	if (queue_conflict(&r->res_grantqueue, lkb))
1651		goto out;
1652
1653	/*
1654	 * 6-3: By default, a conversion request is immediately granted if the
1655	 * requested mode is compatible with the modes of all other granted
1656	 * locks
1657	 */
1658
1659	if (queue_conflict(&r->res_convertqueue, lkb))
1660		goto out;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1661
1662	/*
1663	 * 6-5: But the default algorithm for deciding whether to grant or
1664	 * queue conversion requests does not by itself guarantee that such
1665	 * requests are serviced on a "first come first serve" basis.  This, in
1666	 * turn, can lead to a phenomenon known as "indefinate postponement".
1667	 *
1668	 * 6-7: This issue is dealt with by using the optional QUECVT flag with
1669	 * the system service employed to request a lock conversion.  This flag
1670	 * forces certain conversion requests to be queued, even if they are
1671	 * compatible with the granted modes of other locks on the same
1672	 * resource.  Thus, the use of this flag results in conversion requests
1673	 * being ordered on a "first come first servce" basis.
1674	 *
1675	 * DCT: This condition is all about new conversions being able to occur
1676	 * "in place" while the lock remains on the granted queue (assuming
1677	 * nothing else conflicts.)  IOW if QUECVT isn't set, a conversion
1678	 * doesn't _have_ to go onto the convert queue where it's processed in
1679	 * order.  The "now" variable is necessary to distinguish converts
1680	 * being received and processed for the first time now, because once a
1681	 * convert is moved to the conversion queue the condition below applies
1682	 * requiring fifo granting.
1683	 */
1684
1685	if (now && conv && !(lkb->lkb_exflags & DLM_LKF_QUECVT))
1686		return 1;
1687
1688	/*
 
 
 
 
 
 
 
 
 
 
 
 
1689	 * The NOORDER flag is set to avoid the standard vms rules on grant
1690	 * order.
1691	 */
1692
1693	if (lkb->lkb_exflags & DLM_LKF_NOORDER)
1694		return 1;
1695
1696	/*
1697	 * 6-3: Once in that queue [CONVERTING], a conversion request cannot be
1698	 * granted until all other conversion requests ahead of it are granted
1699	 * and/or canceled.
1700	 */
1701
1702	if (!now && conv && first_in_list(lkb, &r->res_convertqueue))
1703		return 1;
1704
1705	/*
1706	 * 6-4: By default, a new request is immediately granted only if all
1707	 * three of the following conditions are satisfied when the request is
1708	 * issued:
1709	 * - The queue of ungranted conversion requests for the resource is
1710	 *   empty.
1711	 * - The queue of ungranted new requests for the resource is empty.
1712	 * - The mode of the new request is compatible with the most
1713	 *   restrictive mode of all granted locks on the resource.
1714	 */
1715
1716	if (now && !conv && list_empty(&r->res_convertqueue) &&
1717	    list_empty(&r->res_waitqueue))
1718		return 1;
1719
1720	/*
1721	 * 6-4: Once a lock request is in the queue of ungranted new requests,
1722	 * it cannot be granted until the queue of ungranted conversion
1723	 * requests is empty, all ungranted new requests ahead of it are
1724	 * granted and/or canceled, and it is compatible with the granted mode
1725	 * of the most restrictive lock granted on the resource.
1726	 */
1727
1728	if (!now && !conv && list_empty(&r->res_convertqueue) &&
1729	    first_in_list(lkb, &r->res_waitqueue))
1730		return 1;
1731 out:
1732	return 0;
1733}
1734
1735static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now,
1736			  int *err)
1737{
1738	int rv;
1739	int8_t alt = 0, rqmode = lkb->lkb_rqmode;
1740	int8_t is_convert = (lkb->lkb_grmode != DLM_LOCK_IV);
1741
1742	if (err)
1743		*err = 0;
1744
1745	rv = _can_be_granted(r, lkb, now);
1746	if (rv)
1747		goto out;
1748
1749	/*
1750	 * The CONVDEADLK flag is non-standard and tells the dlm to resolve
1751	 * conversion deadlocks by demoting grmode to NL, otherwise the dlm
1752	 * cancels one of the locks.
1753	 */
1754
1755	if (is_convert && can_be_queued(lkb) &&
1756	    conversion_deadlock_detect(r, lkb)) {
1757		if (lkb->lkb_exflags & DLM_LKF_CONVDEADLK) {
1758			lkb->lkb_grmode = DLM_LOCK_NL;
1759			lkb->lkb_sbflags |= DLM_SBF_DEMOTED;
1760		} else if (!(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
1761			if (err)
1762				*err = -EDEADLK;
1763			else {
1764				log_print("can_be_granted deadlock %x now %d",
1765					  lkb->lkb_id, now);
1766				dlm_dump_rsb(r);
1767			}
1768		}
1769		goto out;
1770	}
1771
1772	/*
1773	 * The ALTPR and ALTCW flags are non-standard and tell the dlm to try
1774	 * to grant a request in a mode other than the normal rqmode.  It's a
1775	 * simple way to provide a big optimization to applications that can
1776	 * use them.
1777	 */
1778
1779	if (rqmode != DLM_LOCK_PR && (lkb->lkb_exflags & DLM_LKF_ALTPR))
1780		alt = DLM_LOCK_PR;
1781	else if (rqmode != DLM_LOCK_CW && (lkb->lkb_exflags & DLM_LKF_ALTCW))
1782		alt = DLM_LOCK_CW;
1783
1784	if (alt) {
1785		lkb->lkb_rqmode = alt;
1786		rv = _can_be_granted(r, lkb, now);
1787		if (rv)
1788			lkb->lkb_sbflags |= DLM_SBF_ALTMODE;
1789		else
1790			lkb->lkb_rqmode = rqmode;
1791	}
1792 out:
1793	return rv;
1794}
1795
1796/* FIXME: I don't think that can_be_granted() can/will demote or find deadlock
1797   for locks pending on the convert list.  Once verified (watch for these
1798   log_prints), we should be able to just call _can_be_granted() and not
1799   bother with the demote/deadlk cases here (and there's no easy way to deal
1800   with a deadlk here, we'd have to generate something like grant_lock with
1801   the deadlk error.) */
1802
1803/* Returns the highest requested mode of all blocked conversions; sets
1804   cw if there's a blocked conversion to DLM_LOCK_CW. */
1805
1806static int grant_pending_convert(struct dlm_rsb *r, int high, int *cw)
 
1807{
1808	struct dlm_lkb *lkb, *s;
 
1809	int hi, demoted, quit, grant_restart, demote_restart;
1810	int deadlk;
1811
1812	quit = 0;
1813 restart:
1814	grant_restart = 0;
1815	demote_restart = 0;
1816	hi = DLM_LOCK_IV;
1817
1818	list_for_each_entry_safe(lkb, s, &r->res_convertqueue, lkb_statequeue) {
1819		demoted = is_demoted(lkb);
1820		deadlk = 0;
1821
1822		if (can_be_granted(r, lkb, 0, &deadlk)) {
1823			grant_lock_pending(r, lkb);
1824			grant_restart = 1;
 
 
1825			continue;
1826		}
1827
1828		if (!demoted && is_demoted(lkb)) {
1829			log_print("WARN: pending demoted %x node %d %s",
1830				  lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
1831			demote_restart = 1;
1832			continue;
1833		}
1834
1835		if (deadlk) {
1836			log_print("WARN: pending deadlock %x node %d %s",
1837				  lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
1838			dlm_dump_rsb(r);
 
 
 
 
 
 
 
 
 
 
 
 
 
1839			continue;
1840		}
1841
1842		hi = max_t(int, lkb->lkb_rqmode, hi);
1843
1844		if (cw && lkb->lkb_rqmode == DLM_LOCK_CW)
1845			*cw = 1;
1846	}
1847
1848	if (grant_restart)
1849		goto restart;
1850	if (demote_restart && !quit) {
1851		quit = 1;
1852		goto restart;
1853	}
1854
1855	return max_t(int, high, hi);
1856}
1857
1858static int grant_pending_wait(struct dlm_rsb *r, int high, int *cw)
 
1859{
1860	struct dlm_lkb *lkb, *s;
1861
1862	list_for_each_entry_safe(lkb, s, &r->res_waitqueue, lkb_statequeue) {
1863		if (can_be_granted(r, lkb, 0, NULL))
1864			grant_lock_pending(r, lkb);
1865                else {
 
 
1866			high = max_t(int, lkb->lkb_rqmode, high);
1867			if (lkb->lkb_rqmode == DLM_LOCK_CW)
1868				*cw = 1;
1869		}
1870	}
1871
1872	return high;
1873}
1874
1875/* cw of 1 means there's a lock with a rqmode of DLM_LOCK_CW that's blocked
1876   on either the convert or waiting queue.
1877   high is the largest rqmode of all locks blocked on the convert or
1878   waiting queue. */
1879
1880static int lock_requires_bast(struct dlm_lkb *gr, int high, int cw)
1881{
1882	if (gr->lkb_grmode == DLM_LOCK_PR && cw) {
1883		if (gr->lkb_highbast < DLM_LOCK_EX)
1884			return 1;
1885		return 0;
1886	}
1887
1888	if (gr->lkb_highbast < high &&
1889	    !__dlm_compat_matrix[gr->lkb_grmode+1][high+1])
1890		return 1;
1891	return 0;
1892}
1893
1894static void grant_pending_locks(struct dlm_rsb *r)
1895{
1896	struct dlm_lkb *lkb, *s;
1897	int high = DLM_LOCK_IV;
1898	int cw = 0;
1899
1900	DLM_ASSERT(is_master(r), dlm_dump_rsb(r););
 
 
 
 
1901
1902	high = grant_pending_convert(r, high, &cw);
1903	high = grant_pending_wait(r, high, &cw);
1904
1905	if (high == DLM_LOCK_IV)
1906		return;
1907
1908	/*
1909	 * If there are locks left on the wait/convert queue then send blocking
1910	 * ASTs to granted locks based on the largest requested mode (high)
1911	 * found above.
1912	 */
1913
1914	list_for_each_entry_safe(lkb, s, &r->res_grantqueue, lkb_statequeue) {
1915		if (lkb->lkb_bastfn && lock_requires_bast(lkb, high, cw)) {
1916			if (cw && high == DLM_LOCK_PR &&
1917			    lkb->lkb_grmode == DLM_LOCK_PR)
1918				queue_bast(r, lkb, DLM_LOCK_CW);
1919			else
1920				queue_bast(r, lkb, high);
1921			lkb->lkb_highbast = high;
1922		}
1923	}
1924}
1925
1926static int modes_require_bast(struct dlm_lkb *gr, struct dlm_lkb *rq)
1927{
1928	if ((gr->lkb_grmode == DLM_LOCK_PR && rq->lkb_rqmode == DLM_LOCK_CW) ||
1929	    (gr->lkb_grmode == DLM_LOCK_CW && rq->lkb_rqmode == DLM_LOCK_PR)) {
1930		if (gr->lkb_highbast < DLM_LOCK_EX)
1931			return 1;
1932		return 0;
1933	}
1934
1935	if (gr->lkb_highbast < rq->lkb_rqmode && !modes_compat(gr, rq))
1936		return 1;
1937	return 0;
1938}
1939
1940static void send_bast_queue(struct dlm_rsb *r, struct list_head *head,
1941			    struct dlm_lkb *lkb)
1942{
1943	struct dlm_lkb *gr;
1944
1945	list_for_each_entry(gr, head, lkb_statequeue) {
1946		/* skip self when sending basts to convertqueue */
1947		if (gr == lkb)
1948			continue;
1949		if (gr->lkb_bastfn && modes_require_bast(gr, lkb)) {
1950			queue_bast(r, gr, lkb->lkb_rqmode);
1951			gr->lkb_highbast = lkb->lkb_rqmode;
1952		}
1953	}
1954}
1955
1956static void send_blocking_asts(struct dlm_rsb *r, struct dlm_lkb *lkb)
1957{
1958	send_bast_queue(r, &r->res_grantqueue, lkb);
1959}
1960
1961static void send_blocking_asts_all(struct dlm_rsb *r, struct dlm_lkb *lkb)
1962{
1963	send_bast_queue(r, &r->res_grantqueue, lkb);
1964	send_bast_queue(r, &r->res_convertqueue, lkb);
1965}
1966
1967/* set_master(r, lkb) -- set the master nodeid of a resource
1968
1969   The purpose of this function is to set the nodeid field in the given
1970   lkb using the nodeid field in the given rsb.  If the rsb's nodeid is
1971   known, it can just be copied to the lkb and the function will return
1972   0.  If the rsb's nodeid is _not_ known, it needs to be looked up
1973   before it can be copied to the lkb.
1974
1975   When the rsb nodeid is being looked up remotely, the initial lkb
1976   causing the lookup is kept on the ls_waiters list waiting for the
1977   lookup reply.  Other lkb's waiting for the same rsb lookup are kept
1978   on the rsb's res_lookup list until the master is verified.
1979
1980   Return values:
1981   0: nodeid is set in rsb/lkb and the caller should go ahead and use it
1982   1: the rsb master is not available and the lkb has been placed on
1983      a wait queue
1984*/
1985
1986static int set_master(struct dlm_rsb *r, struct dlm_lkb *lkb)
1987{
1988	struct dlm_ls *ls = r->res_ls;
1989	int i, error, dir_nodeid, ret_nodeid, our_nodeid = dlm_our_nodeid();
1990
1991	if (rsb_flag(r, RSB_MASTER_UNCERTAIN)) {
1992		rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
1993		r->res_first_lkid = lkb->lkb_id;
1994		lkb->lkb_nodeid = r->res_nodeid;
1995		return 0;
1996	}
1997
1998	if (r->res_first_lkid && r->res_first_lkid != lkb->lkb_id) {
1999		list_add_tail(&lkb->lkb_rsb_lookup, &r->res_lookup);
2000		return 1;
2001	}
2002
2003	if (r->res_nodeid == 0) {
2004		lkb->lkb_nodeid = 0;
2005		return 0;
2006	}
2007
2008	if (r->res_nodeid > 0) {
2009		lkb->lkb_nodeid = r->res_nodeid;
2010		return 0;
2011	}
2012
2013	DLM_ASSERT(r->res_nodeid == -1, dlm_dump_rsb(r););
2014
2015	dir_nodeid = dlm_dir_nodeid(r);
2016
2017	if (dir_nodeid != our_nodeid) {
2018		r->res_first_lkid = lkb->lkb_id;
2019		send_lookup(r, lkb);
2020		return 1;
2021	}
2022
2023	for (i = 0; i < 2; i++) {
2024		/* It's possible for dlm_scand to remove an old rsb for
2025		   this same resource from the toss list, us to create
2026		   a new one, look up the master locally, and find it
2027		   already exists just before dlm_scand does the
2028		   dir_remove() on the previous rsb. */
2029
2030		error = dlm_dir_lookup(ls, our_nodeid, r->res_name,
2031				       r->res_length, &ret_nodeid);
2032		if (!error)
2033			break;
2034		log_debug(ls, "dir_lookup error %d %s", error, r->res_name);
2035		schedule();
2036	}
2037	if (error && error != -EEXIST)
2038		return error;
2039
2040	if (ret_nodeid == our_nodeid) {
2041		r->res_first_lkid = 0;
2042		r->res_nodeid = 0;
2043		lkb->lkb_nodeid = 0;
2044	} else {
2045		r->res_first_lkid = lkb->lkb_id;
2046		r->res_nodeid = ret_nodeid;
2047		lkb->lkb_nodeid = ret_nodeid;
2048	}
2049	return 0;
 
 
 
 
 
2050}
2051
2052static void process_lookup_list(struct dlm_rsb *r)
2053{
2054	struct dlm_lkb *lkb, *safe;
2055
2056	list_for_each_entry_safe(lkb, safe, &r->res_lookup, lkb_rsb_lookup) {
2057		list_del_init(&lkb->lkb_rsb_lookup);
2058		_request_lock(r, lkb);
2059		schedule();
2060	}
2061}
2062
2063/* confirm_master -- confirm (or deny) an rsb's master nodeid */
2064
2065static void confirm_master(struct dlm_rsb *r, int error)
2066{
2067	struct dlm_lkb *lkb;
2068
2069	if (!r->res_first_lkid)
2070		return;
2071
2072	switch (error) {
2073	case 0:
2074	case -EINPROGRESS:
2075		r->res_first_lkid = 0;
2076		process_lookup_list(r);
2077		break;
2078
2079	case -EAGAIN:
2080	case -EBADR:
2081	case -ENOTBLK:
2082		/* the remote request failed and won't be retried (it was
2083		   a NOQUEUE, or has been canceled/unlocked); make a waiting
2084		   lkb the first_lkid */
2085
2086		r->res_first_lkid = 0;
2087
2088		if (!list_empty(&r->res_lookup)) {
2089			lkb = list_entry(r->res_lookup.next, struct dlm_lkb,
2090					 lkb_rsb_lookup);
2091			list_del_init(&lkb->lkb_rsb_lookup);
2092			r->res_first_lkid = lkb->lkb_id;
2093			_request_lock(r, lkb);
2094		}
2095		break;
2096
2097	default:
2098		log_error(r->res_ls, "confirm_master unknown error %d", error);
2099	}
2100}
2101
2102static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags,
2103			 int namelen, unsigned long timeout_cs,
2104			 void (*ast) (void *astparam),
2105			 void *astparam,
2106			 void (*bast) (void *astparam, int mode),
2107			 struct dlm_args *args)
2108{
2109	int rv = -EINVAL;
2110
2111	/* check for invalid arg usage */
2112
2113	if (mode < 0 || mode > DLM_LOCK_EX)
2114		goto out;
2115
2116	if (!(flags & DLM_LKF_CONVERT) && (namelen > DLM_RESNAME_MAXLEN))
2117		goto out;
2118
2119	if (flags & DLM_LKF_CANCEL)
2120		goto out;
2121
2122	if (flags & DLM_LKF_QUECVT && !(flags & DLM_LKF_CONVERT))
2123		goto out;
2124
2125	if (flags & DLM_LKF_CONVDEADLK && !(flags & DLM_LKF_CONVERT))
2126		goto out;
2127
2128	if (flags & DLM_LKF_CONVDEADLK && flags & DLM_LKF_NOQUEUE)
2129		goto out;
2130
2131	if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_CONVERT)
2132		goto out;
2133
2134	if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_QUECVT)
2135		goto out;
2136
2137	if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_NOQUEUE)
2138		goto out;
2139
2140	if (flags & DLM_LKF_EXPEDITE && mode != DLM_LOCK_NL)
2141		goto out;
2142
2143	if (!ast || !lksb)
2144		goto out;
2145
2146	if (flags & DLM_LKF_VALBLK && !lksb->sb_lvbptr)
2147		goto out;
2148
2149	if (flags & DLM_LKF_CONVERT && !lksb->sb_lkid)
2150		goto out;
2151
2152	/* these args will be copied to the lkb in validate_lock_args,
2153	   it cannot be done now because when converting locks, fields in
2154	   an active lkb cannot be modified before locking the rsb */
2155
2156	args->flags = flags;
2157	args->astfn = ast;
2158	args->astparam = astparam;
2159	args->bastfn = bast;
2160	args->timeout = timeout_cs;
2161	args->mode = mode;
2162	args->lksb = lksb;
2163	rv = 0;
2164 out:
2165	return rv;
2166}
2167
2168static int set_unlock_args(uint32_t flags, void *astarg, struct dlm_args *args)
2169{
2170	if (flags & ~(DLM_LKF_CANCEL | DLM_LKF_VALBLK | DLM_LKF_IVVALBLK |
2171 		      DLM_LKF_FORCEUNLOCK))
2172		return -EINVAL;
2173
2174	if (flags & DLM_LKF_CANCEL && flags & DLM_LKF_FORCEUNLOCK)
2175		return -EINVAL;
2176
2177	args->flags = flags;
2178	args->astparam = astarg;
2179	return 0;
2180}
2181
2182static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
2183			      struct dlm_args *args)
2184{
2185	int rv = -EINVAL;
2186
2187	if (args->flags & DLM_LKF_CONVERT) {
2188		if (lkb->lkb_flags & DLM_IFL_MSTCPY)
2189			goto out;
2190
2191		if (args->flags & DLM_LKF_QUECVT &&
2192		    !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1])
2193			goto out;
2194
2195		rv = -EBUSY;
2196		if (lkb->lkb_status != DLM_LKSTS_GRANTED)
2197			goto out;
2198
2199		if (lkb->lkb_wait_type)
2200			goto out;
2201
2202		if (is_overlap(lkb))
2203			goto out;
2204	}
2205
2206	lkb->lkb_exflags = args->flags;
2207	lkb->lkb_sbflags = 0;
2208	lkb->lkb_astfn = args->astfn;
2209	lkb->lkb_astparam = args->astparam;
2210	lkb->lkb_bastfn = args->bastfn;
2211	lkb->lkb_rqmode = args->mode;
2212	lkb->lkb_lksb = args->lksb;
2213	lkb->lkb_lvbptr = args->lksb->sb_lvbptr;
2214	lkb->lkb_ownpid = (int) current->pid;
2215	lkb->lkb_timeout_cs = args->timeout;
2216	rv = 0;
2217 out:
2218	if (rv)
2219		log_debug(ls, "validate_lock_args %d %x %x %x %d %d %s",
2220			  rv, lkb->lkb_id, lkb->lkb_flags, args->flags,
2221			  lkb->lkb_status, lkb->lkb_wait_type,
2222			  lkb->lkb_resource->res_name);
2223	return rv;
2224}
2225
2226/* when dlm_unlock() sees -EBUSY with CANCEL/FORCEUNLOCK it returns 0
2227   for success */
2228
2229/* note: it's valid for lkb_nodeid/res_nodeid to be -1 when we get here
2230   because there may be a lookup in progress and it's valid to do
2231   cancel/unlockf on it */
2232
2233static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args)
2234{
2235	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
2236	int rv = -EINVAL;
2237
2238	if (lkb->lkb_flags & DLM_IFL_MSTCPY) {
2239		log_error(ls, "unlock on MSTCPY %x", lkb->lkb_id);
2240		dlm_print_lkb(lkb);
2241		goto out;
2242	}
2243
2244	/* an lkb may still exist even though the lock is EOL'ed due to a
2245	   cancel, unlock or failed noqueue request; an app can't use these
2246	   locks; return same error as if the lkid had not been found at all */
2247
2248	if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) {
2249		log_debug(ls, "unlock on ENDOFLIFE %x", lkb->lkb_id);
2250		rv = -ENOENT;
2251		goto out;
2252	}
2253
2254	/* an lkb may be waiting for an rsb lookup to complete where the
2255	   lookup was initiated by another lock */
2256
2257	if (!list_empty(&lkb->lkb_rsb_lookup)) {
2258		if (args->flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)) {
2259			log_debug(ls, "unlock on rsb_lookup %x", lkb->lkb_id);
2260			list_del_init(&lkb->lkb_rsb_lookup);
2261			queue_cast(lkb->lkb_resource, lkb,
2262				   args->flags & DLM_LKF_CANCEL ?
2263				   -DLM_ECANCEL : -DLM_EUNLOCK);
2264			unhold_lkb(lkb); /* undoes create_lkb() */
2265		}
2266		/* caller changes -EBUSY to 0 for CANCEL and FORCEUNLOCK */
2267		rv = -EBUSY;
2268		goto out;
2269	}
2270
2271	/* cancel not allowed with another cancel/unlock in progress */
2272
2273	if (args->flags & DLM_LKF_CANCEL) {
2274		if (lkb->lkb_exflags & DLM_LKF_CANCEL)
2275			goto out;
2276
2277		if (is_overlap(lkb))
2278			goto out;
2279
2280		/* don't let scand try to do a cancel */
2281		del_timeout(lkb);
2282
2283		if (lkb->lkb_flags & DLM_IFL_RESEND) {
2284			lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
2285			rv = -EBUSY;
2286			goto out;
2287		}
2288
2289		/* there's nothing to cancel */
2290		if (lkb->lkb_status == DLM_LKSTS_GRANTED &&
2291		    !lkb->lkb_wait_type) {
2292			rv = -EBUSY;
2293			goto out;
2294		}
2295
2296		switch (lkb->lkb_wait_type) {
2297		case DLM_MSG_LOOKUP:
2298		case DLM_MSG_REQUEST:
2299			lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
2300			rv = -EBUSY;
2301			goto out;
2302		case DLM_MSG_UNLOCK:
2303		case DLM_MSG_CANCEL:
2304			goto out;
2305		}
2306		/* add_to_waiters() will set OVERLAP_CANCEL */
2307		goto out_ok;
2308	}
2309
2310	/* do we need to allow a force-unlock if there's a normal unlock
2311	   already in progress?  in what conditions could the normal unlock
2312	   fail such that we'd want to send a force-unlock to be sure? */
2313
2314	if (args->flags & DLM_LKF_FORCEUNLOCK) {
2315		if (lkb->lkb_exflags & DLM_LKF_FORCEUNLOCK)
2316			goto out;
2317
2318		if (is_overlap_unlock(lkb))
2319			goto out;
2320
2321		/* don't let scand try to do a cancel */
2322		del_timeout(lkb);
2323
2324		if (lkb->lkb_flags & DLM_IFL_RESEND) {
2325			lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
2326			rv = -EBUSY;
2327			goto out;
2328		}
2329
2330		switch (lkb->lkb_wait_type) {
2331		case DLM_MSG_LOOKUP:
2332		case DLM_MSG_REQUEST:
2333			lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
2334			rv = -EBUSY;
2335			goto out;
2336		case DLM_MSG_UNLOCK:
2337			goto out;
2338		}
2339		/* add_to_waiters() will set OVERLAP_UNLOCK */
2340		goto out_ok;
2341	}
2342
2343	/* normal unlock not allowed if there's any op in progress */
2344	rv = -EBUSY;
2345	if (lkb->lkb_wait_type || lkb->lkb_wait_count)
2346		goto out;
2347
2348 out_ok:
2349	/* an overlapping op shouldn't blow away exflags from other op */
2350	lkb->lkb_exflags |= args->flags;
2351	lkb->lkb_sbflags = 0;
2352	lkb->lkb_astparam = args->astparam;
2353	rv = 0;
2354 out:
2355	if (rv)
2356		log_debug(ls, "validate_unlock_args %d %x %x %x %x %d %s", rv,
2357			  lkb->lkb_id, lkb->lkb_flags, lkb->lkb_exflags,
2358			  args->flags, lkb->lkb_wait_type,
2359			  lkb->lkb_resource->res_name);
2360	return rv;
2361}
2362
2363/*
2364 * Four stage 4 varieties:
2365 * do_request(), do_convert(), do_unlock(), do_cancel()
2366 * These are called on the master node for the given lock and
2367 * from the central locking logic.
2368 */
2369
2370static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
2371{
2372	int error = 0;
2373
2374	if (can_be_granted(r, lkb, 1, NULL)) {
2375		grant_lock(r, lkb);
2376		queue_cast(r, lkb, 0);
2377		goto out;
2378	}
2379
2380	if (can_be_queued(lkb)) {
2381		error = -EINPROGRESS;
2382		add_lkb(r, lkb, DLM_LKSTS_WAITING);
2383		add_timeout(lkb);
2384		goto out;
2385	}
2386
2387	error = -EAGAIN;
2388	queue_cast(r, lkb, -EAGAIN);
2389 out:
2390	return error;
2391}
2392
2393static void do_request_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
2394			       int error)
2395{
2396	switch (error) {
2397	case -EAGAIN:
2398		if (force_blocking_asts(lkb))
2399			send_blocking_asts_all(r, lkb);
2400		break;
2401	case -EINPROGRESS:
2402		send_blocking_asts(r, lkb);
2403		break;
2404	}
2405}
2406
2407static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
2408{
2409	int error = 0;
2410	int deadlk = 0;
2411
2412	/* changing an existing lock may allow others to be granted */
2413
2414	if (can_be_granted(r, lkb, 1, &deadlk)) {
2415		grant_lock(r, lkb);
2416		queue_cast(r, lkb, 0);
2417		goto out;
2418	}
2419
2420	/* can_be_granted() detected that this lock would block in a conversion
2421	   deadlock, so we leave it on the granted queue and return EDEADLK in
2422	   the ast for the convert. */
2423
2424	if (deadlk) {
2425		/* it's left on the granted queue */
2426		revert_lock(r, lkb);
2427		queue_cast(r, lkb, -EDEADLK);
2428		error = -EDEADLK;
2429		goto out;
2430	}
2431
2432	/* is_demoted() means the can_be_granted() above set the grmode
2433	   to NL, and left us on the granted queue.  This auto-demotion
2434	   (due to CONVDEADLK) might mean other locks, and/or this lock, are
2435	   now grantable.  We have to try to grant other converting locks
2436	   before we try again to grant this one. */
2437
2438	if (is_demoted(lkb)) {
2439		grant_pending_convert(r, DLM_LOCK_IV, NULL);
2440		if (_can_be_granted(r, lkb, 1)) {
2441			grant_lock(r, lkb);
2442			queue_cast(r, lkb, 0);
2443			goto out;
2444		}
2445		/* else fall through and move to convert queue */
2446	}
2447
2448	if (can_be_queued(lkb)) {
2449		error = -EINPROGRESS;
2450		del_lkb(r, lkb);
2451		add_lkb(r, lkb, DLM_LKSTS_CONVERT);
2452		add_timeout(lkb);
2453		goto out;
2454	}
2455
2456	error = -EAGAIN;
2457	queue_cast(r, lkb, -EAGAIN);
2458 out:
2459	return error;
2460}
2461
2462static void do_convert_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
2463			       int error)
2464{
2465	switch (error) {
2466	case 0:
2467		grant_pending_locks(r);
2468		/* grant_pending_locks also sends basts */
2469		break;
2470	case -EAGAIN:
2471		if (force_blocking_asts(lkb))
2472			send_blocking_asts_all(r, lkb);
2473		break;
2474	case -EINPROGRESS:
2475		send_blocking_asts(r, lkb);
2476		break;
2477	}
2478}
2479
2480static int do_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2481{
2482	remove_lock(r, lkb);
2483	queue_cast(r, lkb, -DLM_EUNLOCK);
2484	return -DLM_EUNLOCK;
2485}
2486
2487static void do_unlock_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
2488			      int error)
2489{
2490	grant_pending_locks(r);
2491}
2492
2493/* returns: 0 did nothing, -DLM_ECANCEL canceled lock */
2494 
2495static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
2496{
2497	int error;
2498
2499	error = revert_lock(r, lkb);
2500	if (error) {
2501		queue_cast(r, lkb, -DLM_ECANCEL);
2502		return -DLM_ECANCEL;
2503	}
2504	return 0;
2505}
2506
2507static void do_cancel_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
2508			      int error)
2509{
2510	if (error)
2511		grant_pending_locks(r);
2512}
2513
2514/*
2515 * Four stage 3 varieties:
2516 * _request_lock(), _convert_lock(), _unlock_lock(), _cancel_lock()
2517 */
2518
2519/* add a new lkb to a possibly new rsb, called by requesting process */
2520
2521static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2522{
2523	int error;
2524
2525	/* set_master: sets lkb nodeid from r */
2526
2527	error = set_master(r, lkb);
2528	if (error < 0)
2529		goto out;
2530	if (error) {
2531		error = 0;
2532		goto out;
2533	}
2534
2535	if (is_remote(r)) {
2536		/* receive_request() calls do_request() on remote node */
2537		error = send_request(r, lkb);
2538	} else {
2539		error = do_request(r, lkb);
2540		/* for remote locks the request_reply is sent
2541		   between do_request and do_request_effects */
2542		do_request_effects(r, lkb, error);
2543	}
2544 out:
2545	return error;
2546}
2547
2548/* change some property of an existing lkb, e.g. mode */
2549
2550static int _convert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2551{
2552	int error;
2553
2554	if (is_remote(r)) {
2555		/* receive_convert() calls do_convert() on remote node */
2556		error = send_convert(r, lkb);
2557	} else {
2558		error = do_convert(r, lkb);
2559		/* for remote locks the convert_reply is sent
2560		   between do_convert and do_convert_effects */
2561		do_convert_effects(r, lkb, error);
2562	}
2563
2564	return error;
2565}
2566
2567/* remove an existing lkb from the granted queue */
2568
2569static int _unlock_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2570{
2571	int error;
2572
2573	if (is_remote(r)) {
2574		/* receive_unlock() calls do_unlock() on remote node */
2575		error = send_unlock(r, lkb);
2576	} else {
2577		error = do_unlock(r, lkb);
2578		/* for remote locks the unlock_reply is sent
2579		   between do_unlock and do_unlock_effects */
2580		do_unlock_effects(r, lkb, error);
2581	}
2582
2583	return error;
2584}
2585
2586/* remove an existing lkb from the convert or wait queue */
2587
2588static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2589{
2590	int error;
2591
2592	if (is_remote(r)) {
2593		/* receive_cancel() calls do_cancel() on remote node */
2594		error = send_cancel(r, lkb);
2595	} else {
2596		error = do_cancel(r, lkb);
2597		/* for remote locks the cancel_reply is sent
2598		   between do_cancel and do_cancel_effects */
2599		do_cancel_effects(r, lkb, error);
2600	}
2601
2602	return error;
2603}
2604
2605/*
2606 * Four stage 2 varieties:
2607 * request_lock(), convert_lock(), unlock_lock(), cancel_lock()
2608 */
2609
2610static int request_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, char *name,
2611			int len, struct dlm_args *args)
2612{
2613	struct dlm_rsb *r;
2614	int error;
2615
2616	error = validate_lock_args(ls, lkb, args);
2617	if (error)
2618		goto out;
2619
2620	error = find_rsb(ls, name, len, R_CREATE, &r);
2621	if (error)
2622		goto out;
2623
2624	lock_rsb(r);
2625
2626	attach_lkb(r, lkb);
2627	lkb->lkb_lksb->sb_lkid = lkb->lkb_id;
2628
2629	error = _request_lock(r, lkb);
2630
2631	unlock_rsb(r);
2632	put_rsb(r);
2633
2634 out:
2635	return error;
2636}
2637
2638static int convert_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
2639			struct dlm_args *args)
2640{
2641	struct dlm_rsb *r;
2642	int error;
2643
2644	r = lkb->lkb_resource;
2645
2646	hold_rsb(r);
2647	lock_rsb(r);
2648
2649	error = validate_lock_args(ls, lkb, args);
2650	if (error)
2651		goto out;
2652
2653	error = _convert_lock(r, lkb);
2654 out:
2655	unlock_rsb(r);
2656	put_rsb(r);
2657	return error;
2658}
2659
2660static int unlock_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
2661		       struct dlm_args *args)
2662{
2663	struct dlm_rsb *r;
2664	int error;
2665
2666	r = lkb->lkb_resource;
2667
2668	hold_rsb(r);
2669	lock_rsb(r);
2670
2671	error = validate_unlock_args(lkb, args);
2672	if (error)
2673		goto out;
2674
2675	error = _unlock_lock(r, lkb);
2676 out:
2677	unlock_rsb(r);
2678	put_rsb(r);
2679	return error;
2680}
2681
2682static int cancel_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
2683		       struct dlm_args *args)
2684{
2685	struct dlm_rsb *r;
2686	int error;
2687
2688	r = lkb->lkb_resource;
2689
2690	hold_rsb(r);
2691	lock_rsb(r);
2692
2693	error = validate_unlock_args(lkb, args);
2694	if (error)
2695		goto out;
2696
2697	error = _cancel_lock(r, lkb);
2698 out:
2699	unlock_rsb(r);
2700	put_rsb(r);
2701	return error;
2702}
2703
2704/*
2705 * Two stage 1 varieties:  dlm_lock() and dlm_unlock()
2706 */
2707
2708int dlm_lock(dlm_lockspace_t *lockspace,
2709	     int mode,
2710	     struct dlm_lksb *lksb,
2711	     uint32_t flags,
2712	     void *name,
2713	     unsigned int namelen,
2714	     uint32_t parent_lkid,
2715	     void (*ast) (void *astarg),
2716	     void *astarg,
2717	     void (*bast) (void *astarg, int mode))
2718{
2719	struct dlm_ls *ls;
2720	struct dlm_lkb *lkb;
2721	struct dlm_args args;
2722	int error, convert = flags & DLM_LKF_CONVERT;
2723
2724	ls = dlm_find_lockspace_local(lockspace);
2725	if (!ls)
2726		return -EINVAL;
2727
2728	dlm_lock_recovery(ls);
2729
2730	if (convert)
2731		error = find_lkb(ls, lksb->sb_lkid, &lkb);
2732	else
2733		error = create_lkb(ls, &lkb);
2734
2735	if (error)
2736		goto out;
2737
2738	error = set_lock_args(mode, lksb, flags, namelen, 0, ast,
2739			      astarg, bast, &args);
2740	if (error)
2741		goto out_put;
2742
2743	if (convert)
2744		error = convert_lock(ls, lkb, &args);
2745	else
2746		error = request_lock(ls, lkb, name, namelen, &args);
2747
2748	if (error == -EINPROGRESS)
2749		error = 0;
2750 out_put:
2751	if (convert || error)
2752		__put_lkb(ls, lkb);
2753	if (error == -EAGAIN || error == -EDEADLK)
2754		error = 0;
2755 out:
2756	dlm_unlock_recovery(ls);
2757	dlm_put_lockspace(ls);
2758	return error;
2759}
2760
2761int dlm_unlock(dlm_lockspace_t *lockspace,
2762	       uint32_t lkid,
2763	       uint32_t flags,
2764	       struct dlm_lksb *lksb,
2765	       void *astarg)
2766{
2767	struct dlm_ls *ls;
2768	struct dlm_lkb *lkb;
2769	struct dlm_args args;
2770	int error;
2771
2772	ls = dlm_find_lockspace_local(lockspace);
2773	if (!ls)
2774		return -EINVAL;
2775
2776	dlm_lock_recovery(ls);
2777
2778	error = find_lkb(ls, lkid, &lkb);
2779	if (error)
2780		goto out;
2781
2782	error = set_unlock_args(flags, astarg, &args);
2783	if (error)
2784		goto out_put;
2785
2786	if (flags & DLM_LKF_CANCEL)
2787		error = cancel_lock(ls, lkb, &args);
2788	else
2789		error = unlock_lock(ls, lkb, &args);
2790
2791	if (error == -DLM_EUNLOCK || error == -DLM_ECANCEL)
2792		error = 0;
2793	if (error == -EBUSY && (flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)))
2794		error = 0;
2795 out_put:
2796	dlm_put_lkb(lkb);
2797 out:
2798	dlm_unlock_recovery(ls);
2799	dlm_put_lockspace(ls);
2800	return error;
2801}
2802
2803/*
2804 * send/receive routines for remote operations and replies
2805 *
2806 * send_args
2807 * send_common
2808 * send_request			receive_request
2809 * send_convert			receive_convert
2810 * send_unlock			receive_unlock
2811 * send_cancel			receive_cancel
2812 * send_grant			receive_grant
2813 * send_bast			receive_bast
2814 * send_lookup			receive_lookup
2815 * send_remove			receive_remove
2816 *
2817 * 				send_common_reply
2818 * receive_request_reply	send_request_reply
2819 * receive_convert_reply	send_convert_reply
2820 * receive_unlock_reply		send_unlock_reply
2821 * receive_cancel_reply		send_cancel_reply
2822 * receive_lookup_reply		send_lookup_reply
2823 */
2824
2825static int _create_message(struct dlm_ls *ls, int mb_len,
2826			   int to_nodeid, int mstype,
2827			   struct dlm_message **ms_ret,
2828			   struct dlm_mhandle **mh_ret)
2829{
2830	struct dlm_message *ms;
2831	struct dlm_mhandle *mh;
2832	char *mb;
2833
2834	/* get_buffer gives us a message handle (mh) that we need to
2835	   pass into lowcomms_commit and a message buffer (mb) that we
2836	   write our data into */
2837
2838	mh = dlm_lowcomms_get_buffer(to_nodeid, mb_len, GFP_NOFS, &mb);
2839	if (!mh)
2840		return -ENOBUFS;
2841
2842	memset(mb, 0, mb_len);
2843
2844	ms = (struct dlm_message *) mb;
2845
2846	ms->m_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
2847	ms->m_header.h_lockspace = ls->ls_global_id;
2848	ms->m_header.h_nodeid = dlm_our_nodeid();
2849	ms->m_header.h_length = mb_len;
2850	ms->m_header.h_cmd = DLM_MSG;
2851
2852	ms->m_type = mstype;
2853
2854	*mh_ret = mh;
2855	*ms_ret = ms;
2856	return 0;
2857}
2858
2859static int create_message(struct dlm_rsb *r, struct dlm_lkb *lkb,
2860			  int to_nodeid, int mstype,
2861			  struct dlm_message **ms_ret,
2862			  struct dlm_mhandle **mh_ret)
2863{
2864	int mb_len = sizeof(struct dlm_message);
2865
2866	switch (mstype) {
2867	case DLM_MSG_REQUEST:
2868	case DLM_MSG_LOOKUP:
2869	case DLM_MSG_REMOVE:
2870		mb_len += r->res_length;
2871		break;
2872	case DLM_MSG_CONVERT:
2873	case DLM_MSG_UNLOCK:
2874	case DLM_MSG_REQUEST_REPLY:
2875	case DLM_MSG_CONVERT_REPLY:
2876	case DLM_MSG_GRANT:
2877		if (lkb && lkb->lkb_lvbptr)
2878			mb_len += r->res_ls->ls_lvblen;
2879		break;
2880	}
2881
2882	return _create_message(r->res_ls, mb_len, to_nodeid, mstype,
2883			       ms_ret, mh_ret);
2884}
2885
2886/* further lowcomms enhancements or alternate implementations may make
2887   the return value from this function useful at some point */
2888
2889static int send_message(struct dlm_mhandle *mh, struct dlm_message *ms)
2890{
2891	dlm_message_out(ms);
2892	dlm_lowcomms_commit_buffer(mh);
2893	return 0;
2894}
2895
2896static void send_args(struct dlm_rsb *r, struct dlm_lkb *lkb,
2897		      struct dlm_message *ms)
2898{
2899	ms->m_nodeid   = lkb->lkb_nodeid;
2900	ms->m_pid      = lkb->lkb_ownpid;
2901	ms->m_lkid     = lkb->lkb_id;
2902	ms->m_remid    = lkb->lkb_remid;
2903	ms->m_exflags  = lkb->lkb_exflags;
2904	ms->m_sbflags  = lkb->lkb_sbflags;
2905	ms->m_flags    = lkb->lkb_flags;
2906	ms->m_lvbseq   = lkb->lkb_lvbseq;
2907	ms->m_status   = lkb->lkb_status;
2908	ms->m_grmode   = lkb->lkb_grmode;
2909	ms->m_rqmode   = lkb->lkb_rqmode;
2910	ms->m_hash     = r->res_hash;
2911
2912	/* m_result and m_bastmode are set from function args,
2913	   not from lkb fields */
2914
2915	if (lkb->lkb_bastfn)
2916		ms->m_asts |= DLM_CB_BAST;
2917	if (lkb->lkb_astfn)
2918		ms->m_asts |= DLM_CB_CAST;
2919
2920	/* compare with switch in create_message; send_remove() doesn't
2921	   use send_args() */
2922
2923	switch (ms->m_type) {
2924	case DLM_MSG_REQUEST:
2925	case DLM_MSG_LOOKUP:
2926		memcpy(ms->m_extra, r->res_name, r->res_length);
2927		break;
2928	case DLM_MSG_CONVERT:
2929	case DLM_MSG_UNLOCK:
2930	case DLM_MSG_REQUEST_REPLY:
2931	case DLM_MSG_CONVERT_REPLY:
2932	case DLM_MSG_GRANT:
2933		if (!lkb->lkb_lvbptr)
2934			break;
2935		memcpy(ms->m_extra, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
2936		break;
2937	}
2938}
2939
2940static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype)
2941{
2942	struct dlm_message *ms;
2943	struct dlm_mhandle *mh;
2944	int to_nodeid, error;
2945
2946	to_nodeid = r->res_nodeid;
2947
2948	error = add_to_waiters(lkb, mstype, to_nodeid);
2949	if (error)
2950		return error;
2951
2952	error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
2953	if (error)
2954		goto fail;
2955
2956	send_args(r, lkb, ms);
2957
2958	error = send_message(mh, ms);
2959	if (error)
2960		goto fail;
2961	return 0;
2962
2963 fail:
2964	remove_from_waiters(lkb, msg_reply_type(mstype));
2965	return error;
2966}
2967
2968static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
2969{
2970	return send_common(r, lkb, DLM_MSG_REQUEST);
2971}
2972
2973static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
2974{
2975	int error;
2976
2977	error = send_common(r, lkb, DLM_MSG_CONVERT);
2978
2979	/* down conversions go without a reply from the master */
2980	if (!error && down_conversion(lkb)) {
2981		remove_from_waiters(lkb, DLM_MSG_CONVERT_REPLY);
2982		r->res_ls->ls_stub_ms.m_flags = DLM_IFL_STUB_MS;
2983		r->res_ls->ls_stub_ms.m_type = DLM_MSG_CONVERT_REPLY;
2984		r->res_ls->ls_stub_ms.m_result = 0;
2985		__receive_convert_reply(r, lkb, &r->res_ls->ls_stub_ms);
2986	}
2987
2988	return error;
2989}
2990
2991/* FIXME: if this lkb is the only lock we hold on the rsb, then set
2992   MASTER_UNCERTAIN to force the next request on the rsb to confirm
2993   that the master is still correct. */
2994
2995static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2996{
2997	return send_common(r, lkb, DLM_MSG_UNLOCK);
2998}
2999
3000static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
3001{
3002	return send_common(r, lkb, DLM_MSG_CANCEL);
3003}
3004
3005static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb)
3006{
3007	struct dlm_message *ms;
3008	struct dlm_mhandle *mh;
3009	int to_nodeid, error;
3010
3011	to_nodeid = lkb->lkb_nodeid;
3012
3013	error = create_message(r, lkb, to_nodeid, DLM_MSG_GRANT, &ms, &mh);
3014	if (error)
3015		goto out;
3016
3017	send_args(r, lkb, ms);
3018
3019	ms->m_result = 0;
3020
3021	error = send_message(mh, ms);
3022 out:
3023	return error;
3024}
3025
3026static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode)
3027{
3028	struct dlm_message *ms;
3029	struct dlm_mhandle *mh;
3030	int to_nodeid, error;
3031
3032	to_nodeid = lkb->lkb_nodeid;
3033
3034	error = create_message(r, NULL, to_nodeid, DLM_MSG_BAST, &ms, &mh);
3035	if (error)
3036		goto out;
3037
3038	send_args(r, lkb, ms);
3039
3040	ms->m_bastmode = mode;
3041
3042	error = send_message(mh, ms);
3043 out:
3044	return error;
3045}
3046
3047static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb)
3048{
3049	struct dlm_message *ms;
3050	struct dlm_mhandle *mh;
3051	int to_nodeid, error;
3052
3053	to_nodeid = dlm_dir_nodeid(r);
3054
3055	error = add_to_waiters(lkb, DLM_MSG_LOOKUP, to_nodeid);
3056	if (error)
3057		return error;
3058
3059	error = create_message(r, NULL, to_nodeid, DLM_MSG_LOOKUP, &ms, &mh);
3060	if (error)
3061		goto fail;
3062
3063	send_args(r, lkb, ms);
3064
3065	error = send_message(mh, ms);
3066	if (error)
3067		goto fail;
3068	return 0;
3069
3070 fail:
3071	remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY);
3072	return error;
3073}
3074
3075static int send_remove(struct dlm_rsb *r)
3076{
3077	struct dlm_message *ms;
3078	struct dlm_mhandle *mh;
3079	int to_nodeid, error;
3080
3081	to_nodeid = dlm_dir_nodeid(r);
3082
3083	error = create_message(r, NULL, to_nodeid, DLM_MSG_REMOVE, &ms, &mh);
3084	if (error)
3085		goto out;
3086
3087	memcpy(ms->m_extra, r->res_name, r->res_length);
3088	ms->m_hash = r->res_hash;
3089
3090	error = send_message(mh, ms);
3091 out:
3092	return error;
3093}
3094
3095static int send_common_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
3096			     int mstype, int rv)
3097{
3098	struct dlm_message *ms;
3099	struct dlm_mhandle *mh;
3100	int to_nodeid, error;
3101
3102	to_nodeid = lkb->lkb_nodeid;
3103
3104	error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
3105	if (error)
3106		goto out;
3107
3108	send_args(r, lkb, ms);
3109
3110	ms->m_result = rv;
3111
3112	error = send_message(mh, ms);
3113 out:
3114	return error;
3115}
3116
3117static int send_request_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3118{
3119	return send_common_reply(r, lkb, DLM_MSG_REQUEST_REPLY, rv);
3120}
3121
3122static int send_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3123{
3124	return send_common_reply(r, lkb, DLM_MSG_CONVERT_REPLY, rv);
3125}
3126
3127static int send_unlock_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3128{
3129	return send_common_reply(r, lkb, DLM_MSG_UNLOCK_REPLY, rv);
3130}
3131
3132static int send_cancel_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3133{
3134	return send_common_reply(r, lkb, DLM_MSG_CANCEL_REPLY, rv);
3135}
3136
3137static int send_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms_in,
3138			     int ret_nodeid, int rv)
3139{
3140	struct dlm_rsb *r = &ls->ls_stub_rsb;
3141	struct dlm_message *ms;
3142	struct dlm_mhandle *mh;
3143	int error, nodeid = ms_in->m_header.h_nodeid;
3144
3145	error = create_message(r, NULL, nodeid, DLM_MSG_LOOKUP_REPLY, &ms, &mh);
3146	if (error)
3147		goto out;
3148
3149	ms->m_lkid = ms_in->m_lkid;
3150	ms->m_result = rv;
3151	ms->m_nodeid = ret_nodeid;
3152
3153	error = send_message(mh, ms);
3154 out:
3155	return error;
3156}
3157
3158/* which args we save from a received message depends heavily on the type
3159   of message, unlike the send side where we can safely send everything about
3160   the lkb for any type of message */
3161
3162static void receive_flags(struct dlm_lkb *lkb, struct dlm_message *ms)
3163{
3164	lkb->lkb_exflags = ms->m_exflags;
3165	lkb->lkb_sbflags = ms->m_sbflags;
3166	lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
3167		         (ms->m_flags & 0x0000FFFF);
3168}
3169
3170static void receive_flags_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3171{
3172	if (ms->m_flags == DLM_IFL_STUB_MS)
3173		return;
3174
3175	lkb->lkb_sbflags = ms->m_sbflags;
3176	lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
3177		         (ms->m_flags & 0x0000FFFF);
3178}
3179
3180static int receive_extralen(struct dlm_message *ms)
3181{
3182	return (ms->m_header.h_length - sizeof(struct dlm_message));
3183}
3184
3185static int receive_lvb(struct dlm_ls *ls, struct dlm_lkb *lkb,
3186		       struct dlm_message *ms)
3187{
3188	int len;
3189
3190	if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
3191		if (!lkb->lkb_lvbptr)
3192			lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
3193		if (!lkb->lkb_lvbptr)
3194			return -ENOMEM;
3195		len = receive_extralen(ms);
3196		if (len > DLM_RESNAME_MAXLEN)
3197			len = DLM_RESNAME_MAXLEN;
3198		memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
3199	}
3200	return 0;
3201}
3202
3203static void fake_bastfn(void *astparam, int mode)
3204{
3205	log_print("fake_bastfn should not be called");
3206}
3207
3208static void fake_astfn(void *astparam)
3209{
3210	log_print("fake_astfn should not be called");
3211}
3212
3213static int receive_request_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3214				struct dlm_message *ms)
3215{
3216	lkb->lkb_nodeid = ms->m_header.h_nodeid;
3217	lkb->lkb_ownpid = ms->m_pid;
3218	lkb->lkb_remid = ms->m_lkid;
3219	lkb->lkb_grmode = DLM_LOCK_IV;
3220	lkb->lkb_rqmode = ms->m_rqmode;
3221
3222	lkb->lkb_bastfn = (ms->m_asts & DLM_CB_BAST) ? &fake_bastfn : NULL;
3223	lkb->lkb_astfn = (ms->m_asts & DLM_CB_CAST) ? &fake_astfn : NULL;
3224
3225	if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
3226		/* lkb was just created so there won't be an lvb yet */
3227		lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
3228		if (!lkb->lkb_lvbptr)
3229			return -ENOMEM;
3230	}
3231
3232	return 0;
3233}
3234
3235static int receive_convert_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3236				struct dlm_message *ms)
3237{
3238	if (lkb->lkb_status != DLM_LKSTS_GRANTED)
3239		return -EBUSY;
3240
3241	if (receive_lvb(ls, lkb, ms))
3242		return -ENOMEM;
3243
3244	lkb->lkb_rqmode = ms->m_rqmode;
3245	lkb->lkb_lvbseq = ms->m_lvbseq;
3246
3247	return 0;
3248}
3249
3250static int receive_unlock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3251			       struct dlm_message *ms)
3252{
3253	if (receive_lvb(ls, lkb, ms))
3254		return -ENOMEM;
3255	return 0;
3256}
3257
3258/* We fill in the stub-lkb fields with the info that send_xxxx_reply()
3259   uses to send a reply and that the remote end uses to process the reply. */
3260
3261static void setup_stub_lkb(struct dlm_ls *ls, struct dlm_message *ms)
3262{
3263	struct dlm_lkb *lkb = &ls->ls_stub_lkb;
3264	lkb->lkb_nodeid = ms->m_header.h_nodeid;
3265	lkb->lkb_remid = ms->m_lkid;
3266}
3267
3268/* This is called after the rsb is locked so that we can safely inspect
3269   fields in the lkb. */
3270
3271static int validate_message(struct dlm_lkb *lkb, struct dlm_message *ms)
3272{
3273	int from = ms->m_header.h_nodeid;
3274	int error = 0;
3275
3276	switch (ms->m_type) {
3277	case DLM_MSG_CONVERT:
3278	case DLM_MSG_UNLOCK:
3279	case DLM_MSG_CANCEL:
3280		if (!is_master_copy(lkb) || lkb->lkb_nodeid != from)
3281			error = -EINVAL;
3282		break;
3283
3284	case DLM_MSG_CONVERT_REPLY:
3285	case DLM_MSG_UNLOCK_REPLY:
3286	case DLM_MSG_CANCEL_REPLY:
3287	case DLM_MSG_GRANT:
3288	case DLM_MSG_BAST:
3289		if (!is_process_copy(lkb) || lkb->lkb_nodeid != from)
3290			error = -EINVAL;
3291		break;
3292
3293	case DLM_MSG_REQUEST_REPLY:
3294		if (!is_process_copy(lkb))
3295			error = -EINVAL;
3296		else if (lkb->lkb_nodeid != -1 && lkb->lkb_nodeid != from)
3297			error = -EINVAL;
3298		break;
3299
3300	default:
3301		error = -EINVAL;
3302	}
3303
3304	if (error)
3305		log_error(lkb->lkb_resource->res_ls,
3306			  "ignore invalid message %d from %d %x %x %x %d",
3307			  ms->m_type, from, lkb->lkb_id, lkb->lkb_remid,
3308			  lkb->lkb_flags, lkb->lkb_nodeid);
3309	return error;
3310}
3311
3312static void receive_request(struct dlm_ls *ls, struct dlm_message *ms)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3313{
3314	struct dlm_lkb *lkb;
3315	struct dlm_rsb *r;
3316	int error, namelen;
 
 
 
3317
3318	error = create_lkb(ls, &lkb);
3319	if (error)
3320		goto fail;
3321
3322	receive_flags(lkb, ms);
3323	lkb->lkb_flags |= DLM_IFL_MSTCPY;
3324	error = receive_request_args(ls, lkb, ms);
3325	if (error) {
3326		__put_lkb(ls, lkb);
3327		goto fail;
3328	}
3329
 
 
 
 
 
 
3330	namelen = receive_extralen(ms);
3331
3332	error = find_rsb(ls, ms->m_extra, namelen, R_MASTER, &r);
 
3333	if (error) {
3334		__put_lkb(ls, lkb);
3335		goto fail;
3336	}
3337
3338	lock_rsb(r);
3339
 
 
 
 
 
 
 
 
 
 
3340	attach_lkb(r, lkb);
3341	error = do_request(r, lkb);
3342	send_request_reply(r, lkb, error);
3343	do_request_effects(r, lkb, error);
3344
3345	unlock_rsb(r);
3346	put_rsb(r);
3347
3348	if (error == -EINPROGRESS)
3349		error = 0;
3350	if (error)
3351		dlm_put_lkb(lkb);
3352	return;
3353
3354 fail:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3355	setup_stub_lkb(ls, ms);
3356	send_request_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
 
3357}
3358
3359static void receive_convert(struct dlm_ls *ls, struct dlm_message *ms)
3360{
3361	struct dlm_lkb *lkb;
3362	struct dlm_rsb *r;
3363	int error, reply = 1;
3364
3365	error = find_lkb(ls, ms->m_remid, &lkb);
3366	if (error)
3367		goto fail;
3368
 
 
 
 
 
 
 
 
 
 
3369	r = lkb->lkb_resource;
3370
3371	hold_rsb(r);
3372	lock_rsb(r);
3373
3374	error = validate_message(lkb, ms);
3375	if (error)
3376		goto out;
3377
3378	receive_flags(lkb, ms);
3379
3380	error = receive_convert_args(ls, lkb, ms);
3381	if (error) {
3382		send_convert_reply(r, lkb, error);
3383		goto out;
3384	}
3385
3386	reply = !down_conversion(lkb);
3387
3388	error = do_convert(r, lkb);
3389	if (reply)
3390		send_convert_reply(r, lkb, error);
3391	do_convert_effects(r, lkb, error);
3392 out:
3393	unlock_rsb(r);
3394	put_rsb(r);
3395	dlm_put_lkb(lkb);
3396	return;
3397
3398 fail:
3399	setup_stub_lkb(ls, ms);
3400	send_convert_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
 
3401}
3402
3403static void receive_unlock(struct dlm_ls *ls, struct dlm_message *ms)
3404{
3405	struct dlm_lkb *lkb;
3406	struct dlm_rsb *r;
3407	int error;
3408
3409	error = find_lkb(ls, ms->m_remid, &lkb);
3410	if (error)
3411		goto fail;
3412
 
 
 
 
 
 
 
 
 
3413	r = lkb->lkb_resource;
3414
3415	hold_rsb(r);
3416	lock_rsb(r);
3417
3418	error = validate_message(lkb, ms);
3419	if (error)
3420		goto out;
3421
3422	receive_flags(lkb, ms);
3423
3424	error = receive_unlock_args(ls, lkb, ms);
3425	if (error) {
3426		send_unlock_reply(r, lkb, error);
3427		goto out;
3428	}
3429
3430	error = do_unlock(r, lkb);
3431	send_unlock_reply(r, lkb, error);
3432	do_unlock_effects(r, lkb, error);
3433 out:
3434	unlock_rsb(r);
3435	put_rsb(r);
3436	dlm_put_lkb(lkb);
3437	return;
3438
3439 fail:
3440	setup_stub_lkb(ls, ms);
3441	send_unlock_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
 
3442}
3443
3444static void receive_cancel(struct dlm_ls *ls, struct dlm_message *ms)
3445{
3446	struct dlm_lkb *lkb;
3447	struct dlm_rsb *r;
3448	int error;
3449
3450	error = find_lkb(ls, ms->m_remid, &lkb);
3451	if (error)
3452		goto fail;
3453
3454	receive_flags(lkb, ms);
3455
3456	r = lkb->lkb_resource;
3457
3458	hold_rsb(r);
3459	lock_rsb(r);
3460
3461	error = validate_message(lkb, ms);
3462	if (error)
3463		goto out;
3464
3465	error = do_cancel(r, lkb);
3466	send_cancel_reply(r, lkb, error);
3467	do_cancel_effects(r, lkb, error);
3468 out:
3469	unlock_rsb(r);
3470	put_rsb(r);
3471	dlm_put_lkb(lkb);
3472	return;
3473
3474 fail:
3475	setup_stub_lkb(ls, ms);
3476	send_cancel_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
 
3477}
3478
3479static void receive_grant(struct dlm_ls *ls, struct dlm_message *ms)
3480{
3481	struct dlm_lkb *lkb;
3482	struct dlm_rsb *r;
3483	int error;
3484
3485	error = find_lkb(ls, ms->m_remid, &lkb);
3486	if (error) {
3487		log_debug(ls, "receive_grant from %d no lkb %x",
3488			  ms->m_header.h_nodeid, ms->m_remid);
3489		return;
3490	}
3491
3492	r = lkb->lkb_resource;
3493
3494	hold_rsb(r);
3495	lock_rsb(r);
3496
3497	error = validate_message(lkb, ms);
3498	if (error)
3499		goto out;
3500
3501	receive_flags_reply(lkb, ms);
3502	if (is_altmode(lkb))
3503		munge_altmode(lkb, ms);
3504	grant_lock_pc(r, lkb, ms);
3505	queue_cast(r, lkb, 0);
3506 out:
3507	unlock_rsb(r);
3508	put_rsb(r);
3509	dlm_put_lkb(lkb);
 
3510}
3511
3512static void receive_bast(struct dlm_ls *ls, struct dlm_message *ms)
3513{
3514	struct dlm_lkb *lkb;
3515	struct dlm_rsb *r;
3516	int error;
3517
3518	error = find_lkb(ls, ms->m_remid, &lkb);
3519	if (error) {
3520		log_debug(ls, "receive_bast from %d no lkb %x",
3521			  ms->m_header.h_nodeid, ms->m_remid);
3522		return;
3523	}
3524
3525	r = lkb->lkb_resource;
3526
3527	hold_rsb(r);
3528	lock_rsb(r);
3529
3530	error = validate_message(lkb, ms);
3531	if (error)
3532		goto out;
3533
3534	queue_bast(r, lkb, ms->m_bastmode);
 
3535 out:
3536	unlock_rsb(r);
3537	put_rsb(r);
3538	dlm_put_lkb(lkb);
 
3539}
3540
3541static void receive_lookup(struct dlm_ls *ls, struct dlm_message *ms)
3542{
3543	int len, error, ret_nodeid, dir_nodeid, from_nodeid, our_nodeid;
3544
3545	from_nodeid = ms->m_header.h_nodeid;
3546	our_nodeid = dlm_our_nodeid();
3547
3548	len = receive_extralen(ms);
3549
3550	dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
3551	if (dir_nodeid != our_nodeid) {
3552		log_error(ls, "lookup dir_nodeid %d from %d",
3553			  dir_nodeid, from_nodeid);
3554		error = -EINVAL;
3555		ret_nodeid = -1;
3556		goto out;
3557	}
3558
3559	error = dlm_dir_lookup(ls, from_nodeid, ms->m_extra, len, &ret_nodeid);
3560
3561	/* Optimization: we're master so treat lookup as a request */
3562	if (!error && ret_nodeid == our_nodeid) {
3563		receive_request(ls, ms);
3564		return;
3565	}
3566 out:
3567	send_lookup_reply(ls, ms, ret_nodeid, error);
3568}
3569
3570static void receive_remove(struct dlm_ls *ls, struct dlm_message *ms)
3571{
3572	int len, dir_nodeid, from_nodeid;
 
 
 
3573
3574	from_nodeid = ms->m_header.h_nodeid;
3575
3576	len = receive_extralen(ms);
3577
 
 
 
 
 
 
3578	dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
3579	if (dir_nodeid != dlm_our_nodeid()) {
3580		log_error(ls, "remove dir entry dir_nodeid %d from %d",
3581			  dir_nodeid, from_nodeid);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3582		return;
3583	}
3584
3585	dlm_dir_remove_entry(ls, from_nodeid, ms->m_extra, len);
 
 
 
 
 
 
 
 
 
3586}
3587
3588static void receive_purge(struct dlm_ls *ls, struct dlm_message *ms)
3589{
3590	do_purge(ls, ms->m_nodeid, ms->m_pid);
3591}
3592
3593static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms)
3594{
3595	struct dlm_lkb *lkb;
3596	struct dlm_rsb *r;
3597	int error, mstype, result;
 
3598
3599	error = find_lkb(ls, ms->m_remid, &lkb);
3600	if (error) {
3601		log_debug(ls, "receive_request_reply from %d no lkb %x",
3602			  ms->m_header.h_nodeid, ms->m_remid);
3603		return;
3604	}
3605
3606	r = lkb->lkb_resource;
3607	hold_rsb(r);
3608	lock_rsb(r);
3609
3610	error = validate_message(lkb, ms);
3611	if (error)
3612		goto out;
3613
3614	mstype = lkb->lkb_wait_type;
3615	error = remove_from_waiters(lkb, DLM_MSG_REQUEST_REPLY);
3616	if (error)
 
 
 
3617		goto out;
 
3618
3619	/* Optimization: the dir node was also the master, so it took our
3620	   lookup as a request and sent request reply instead of lookup reply */
3621	if (mstype == DLM_MSG_LOOKUP) {
3622		r->res_nodeid = ms->m_header.h_nodeid;
3623		lkb->lkb_nodeid = r->res_nodeid;
 
3624	}
3625
3626	/* this is the value returned from do_request() on the master */
3627	result = ms->m_result;
3628
3629	switch (result) {
3630	case -EAGAIN:
3631		/* request would block (be queued) on remote master */
3632		queue_cast(r, lkb, -EAGAIN);
3633		confirm_master(r, -EAGAIN);
3634		unhold_lkb(lkb); /* undoes create_lkb() */
3635		break;
3636
3637	case -EINPROGRESS:
3638	case 0:
3639		/* request was queued or granted on remote master */
3640		receive_flags_reply(lkb, ms);
3641		lkb->lkb_remid = ms->m_lkid;
3642		if (is_altmode(lkb))
3643			munge_altmode(lkb, ms);
3644		if (result) {
3645			add_lkb(r, lkb, DLM_LKSTS_WAITING);
3646			add_timeout(lkb);
3647		} else {
3648			grant_lock_pc(r, lkb, ms);
3649			queue_cast(r, lkb, 0);
3650		}
3651		confirm_master(r, result);
3652		break;
3653
3654	case -EBADR:
3655	case -ENOTBLK:
3656		/* find_rsb failed to find rsb or rsb wasn't master */
3657		log_debug(ls, "receive_request_reply %x %x master diff %d %d",
3658			  lkb->lkb_id, lkb->lkb_flags, r->res_nodeid, result);
3659		r->res_nodeid = -1;
3660		lkb->lkb_nodeid = -1;
 
 
 
 
 
 
 
 
3661
3662		if (is_overlap(lkb)) {
3663			/* we'll ignore error in cancel/unlock reply */
3664			queue_cast_overlap(r, lkb);
3665			confirm_master(r, result);
3666			unhold_lkb(lkb); /* undoes create_lkb() */
3667		} else
3668			_request_lock(r, lkb);
 
 
 
 
3669		break;
3670
3671	default:
3672		log_error(ls, "receive_request_reply %x error %d",
3673			  lkb->lkb_id, result);
3674	}
3675
3676	if (is_overlap_unlock(lkb) && (result == 0 || result == -EINPROGRESS)) {
3677		log_debug(ls, "receive_request_reply %x result %d unlock",
3678			  lkb->lkb_id, result);
3679		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
3680		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
3681		send_unlock(r, lkb);
3682	} else if (is_overlap_cancel(lkb) && (result == -EINPROGRESS)) {
3683		log_debug(ls, "receive_request_reply %x cancel", lkb->lkb_id);
3684		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
3685		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
3686		send_cancel(r, lkb);
3687	} else {
3688		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
3689		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
3690	}
3691 out:
3692	unlock_rsb(r);
3693	put_rsb(r);
3694	dlm_put_lkb(lkb);
 
3695}
3696
3697static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
3698				    struct dlm_message *ms)
3699{
3700	/* this is the value returned from do_convert() on the master */
3701	switch (ms->m_result) {
3702	case -EAGAIN:
3703		/* convert would block (be queued) on remote master */
3704		queue_cast(r, lkb, -EAGAIN);
3705		break;
3706
3707	case -EDEADLK:
3708		receive_flags_reply(lkb, ms);
3709		revert_lock_pc(r, lkb);
3710		queue_cast(r, lkb, -EDEADLK);
3711		break;
3712
3713	case -EINPROGRESS:
3714		/* convert was queued on remote master */
3715		receive_flags_reply(lkb, ms);
3716		if (is_demoted(lkb))
3717			munge_demoted(lkb);
3718		del_lkb(r, lkb);
3719		add_lkb(r, lkb, DLM_LKSTS_CONVERT);
3720		add_timeout(lkb);
3721		break;
3722
3723	case 0:
3724		/* convert was granted on remote master */
3725		receive_flags_reply(lkb, ms);
3726		if (is_demoted(lkb))
3727			munge_demoted(lkb);
3728		grant_lock_pc(r, lkb, ms);
3729		queue_cast(r, lkb, 0);
3730		break;
3731
3732	default:
3733		log_error(r->res_ls, "receive_convert_reply %x error %d",
3734			  lkb->lkb_id, ms->m_result);
 
 
 
3735	}
3736}
3737
3738static void _receive_convert_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3739{
3740	struct dlm_rsb *r = lkb->lkb_resource;
3741	int error;
3742
3743	hold_rsb(r);
3744	lock_rsb(r);
3745
3746	error = validate_message(lkb, ms);
3747	if (error)
3748		goto out;
3749
3750	/* stub reply can happen with waiters_mutex held */
3751	error = remove_from_waiters_ms(lkb, ms);
3752	if (error)
3753		goto out;
3754
3755	__receive_convert_reply(r, lkb, ms);
3756 out:
3757	unlock_rsb(r);
3758	put_rsb(r);
3759}
3760
3761static void receive_convert_reply(struct dlm_ls *ls, struct dlm_message *ms)
3762{
3763	struct dlm_lkb *lkb;
3764	int error;
3765
3766	error = find_lkb(ls, ms->m_remid, &lkb);
3767	if (error) {
3768		log_debug(ls, "receive_convert_reply from %d no lkb %x",
3769			  ms->m_header.h_nodeid, ms->m_remid);
3770		return;
3771	}
3772
3773	_receive_convert_reply(lkb, ms);
3774	dlm_put_lkb(lkb);
 
3775}
3776
3777static void _receive_unlock_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3778{
3779	struct dlm_rsb *r = lkb->lkb_resource;
3780	int error;
3781
3782	hold_rsb(r);
3783	lock_rsb(r);
3784
3785	error = validate_message(lkb, ms);
3786	if (error)
3787		goto out;
3788
3789	/* stub reply can happen with waiters_mutex held */
3790	error = remove_from_waiters_ms(lkb, ms);
3791	if (error)
3792		goto out;
3793
3794	/* this is the value returned from do_unlock() on the master */
3795
3796	switch (ms->m_result) {
3797	case -DLM_EUNLOCK:
3798		receive_flags_reply(lkb, ms);
3799		remove_lock_pc(r, lkb);
3800		queue_cast(r, lkb, -DLM_EUNLOCK);
3801		break;
3802	case -ENOENT:
3803		break;
3804	default:
3805		log_error(r->res_ls, "receive_unlock_reply %x error %d",
3806			  lkb->lkb_id, ms->m_result);
3807	}
3808 out:
3809	unlock_rsb(r);
3810	put_rsb(r);
3811}
3812
3813static void receive_unlock_reply(struct dlm_ls *ls, struct dlm_message *ms)
3814{
3815	struct dlm_lkb *lkb;
3816	int error;
3817
3818	error = find_lkb(ls, ms->m_remid, &lkb);
3819	if (error) {
3820		log_debug(ls, "receive_unlock_reply from %d no lkb %x",
3821			  ms->m_header.h_nodeid, ms->m_remid);
3822		return;
3823	}
3824
3825	_receive_unlock_reply(lkb, ms);
3826	dlm_put_lkb(lkb);
 
3827}
3828
3829static void _receive_cancel_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3830{
3831	struct dlm_rsb *r = lkb->lkb_resource;
3832	int error;
3833
3834	hold_rsb(r);
3835	lock_rsb(r);
3836
3837	error = validate_message(lkb, ms);
3838	if (error)
3839		goto out;
3840
3841	/* stub reply can happen with waiters_mutex held */
3842	error = remove_from_waiters_ms(lkb, ms);
3843	if (error)
3844		goto out;
3845
3846	/* this is the value returned from do_cancel() on the master */
3847
3848	switch (ms->m_result) {
3849	case -DLM_ECANCEL:
3850		receive_flags_reply(lkb, ms);
3851		revert_lock_pc(r, lkb);
3852		queue_cast(r, lkb, -DLM_ECANCEL);
3853		break;
3854	case 0:
3855		break;
3856	default:
3857		log_error(r->res_ls, "receive_cancel_reply %x error %d",
3858			  lkb->lkb_id, ms->m_result);
3859	}
3860 out:
3861	unlock_rsb(r);
3862	put_rsb(r);
3863}
3864
3865static void receive_cancel_reply(struct dlm_ls *ls, struct dlm_message *ms)
3866{
3867	struct dlm_lkb *lkb;
3868	int error;
3869
3870	error = find_lkb(ls, ms->m_remid, &lkb);
3871	if (error) {
3872		log_debug(ls, "receive_cancel_reply from %d no lkb %x",
3873			  ms->m_header.h_nodeid, ms->m_remid);
3874		return;
3875	}
3876
3877	_receive_cancel_reply(lkb, ms);
3878	dlm_put_lkb(lkb);
 
3879}
3880
3881static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms)
3882{
3883	struct dlm_lkb *lkb;
3884	struct dlm_rsb *r;
3885	int error, ret_nodeid;
 
3886
3887	error = find_lkb(ls, ms->m_lkid, &lkb);
3888	if (error) {
3889		log_error(ls, "receive_lookup_reply no lkb");
3890		return;
3891	}
3892
3893	/* ms->m_result is the value returned by dlm_dir_lookup on dir node
3894	   FIXME: will a non-zero error ever be returned? */
3895
3896	r = lkb->lkb_resource;
3897	hold_rsb(r);
3898	lock_rsb(r);
3899
3900	error = remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY);
3901	if (error)
3902		goto out;
3903
3904	ret_nodeid = ms->m_nodeid;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3905	if (ret_nodeid == dlm_our_nodeid()) {
 
3906		r->res_nodeid = 0;
3907		ret_nodeid = 0;
3908		r->res_first_lkid = 0;
 
 
 
 
 
 
 
3909	} else {
3910		/* set_master() will copy res_nodeid to lkb_nodeid */
 
3911		r->res_nodeid = ret_nodeid;
3912	}
3913
3914	if (is_overlap(lkb)) {
3915		log_debug(ls, "receive_lookup_reply %x unlock %x",
3916			  lkb->lkb_id, lkb->lkb_flags);
3917		queue_cast_overlap(r, lkb);
3918		unhold_lkb(lkb); /* undoes create_lkb() */
3919		goto out_list;
3920	}
3921
3922	_request_lock(r, lkb);
3923
3924 out_list:
3925	if (!ret_nodeid)
3926		process_lookup_list(r);
3927 out:
3928	unlock_rsb(r);
3929	put_rsb(r);
3930	dlm_put_lkb(lkb);
3931}
3932
3933static void _receive_message(struct dlm_ls *ls, struct dlm_message *ms)
 
3934{
 
 
3935	if (!dlm_is_member(ls, ms->m_header.h_nodeid)) {
3936		log_debug(ls, "ignore non-member message %d from %d %x %x %d",
3937			  ms->m_type, ms->m_header.h_nodeid, ms->m_lkid,
3938			  ms->m_remid, ms->m_result);
3939		return;
3940	}
3941
3942	switch (ms->m_type) {
3943
3944	/* messages sent to a master node */
3945
3946	case DLM_MSG_REQUEST:
3947		receive_request(ls, ms);
3948		break;
3949
3950	case DLM_MSG_CONVERT:
3951		receive_convert(ls, ms);
3952		break;
3953
3954	case DLM_MSG_UNLOCK:
3955		receive_unlock(ls, ms);
3956		break;
3957
3958	case DLM_MSG_CANCEL:
3959		receive_cancel(ls, ms);
 
3960		break;
3961
3962	/* messages sent from a master node (replies to above) */
3963
3964	case DLM_MSG_REQUEST_REPLY:
3965		receive_request_reply(ls, ms);
3966		break;
3967
3968	case DLM_MSG_CONVERT_REPLY:
3969		receive_convert_reply(ls, ms);
3970		break;
3971
3972	case DLM_MSG_UNLOCK_REPLY:
3973		receive_unlock_reply(ls, ms);
3974		break;
3975
3976	case DLM_MSG_CANCEL_REPLY:
3977		receive_cancel_reply(ls, ms);
3978		break;
3979
3980	/* messages sent from a master node (only two types of async msg) */
3981
3982	case DLM_MSG_GRANT:
3983		receive_grant(ls, ms);
 
3984		break;
3985
3986	case DLM_MSG_BAST:
3987		receive_bast(ls, ms);
 
3988		break;
3989
3990	/* messages sent to a dir node */
3991
3992	case DLM_MSG_LOOKUP:
3993		receive_lookup(ls, ms);
3994		break;
3995
3996	case DLM_MSG_REMOVE:
3997		receive_remove(ls, ms);
3998		break;
3999
4000	/* messages sent from a dir node (remove has no reply) */
4001
4002	case DLM_MSG_LOOKUP_REPLY:
4003		receive_lookup_reply(ls, ms);
4004		break;
4005
4006	/* other messages */
4007
4008	case DLM_MSG_PURGE:
4009		receive_purge(ls, ms);
4010		break;
4011
4012	default:
4013		log_error(ls, "unknown message type %d", ms->m_type);
4014	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4015}
4016
4017/* If the lockspace is in recovery mode (locking stopped), then normal
4018   messages are saved on the requestqueue for processing after recovery is
4019   done.  When not in recovery mode, we wait for dlm_recoverd to drain saved
4020   messages off the requestqueue before we process new ones. This occurs right
4021   after recovery completes when we transition from saving all messages on
4022   requestqueue, to processing all the saved messages, to processing new
4023   messages as they arrive. */
4024
4025static void dlm_receive_message(struct dlm_ls *ls, struct dlm_message *ms,
4026				int nodeid)
4027{
4028	if (dlm_locking_stopped(ls)) {
 
 
 
 
 
 
 
 
 
4029		dlm_add_requestqueue(ls, nodeid, ms);
4030	} else {
4031		dlm_wait_requestqueue(ls);
4032		_receive_message(ls, ms);
4033	}
4034}
4035
4036/* This is called by dlm_recoverd to process messages that were saved on
4037   the requestqueue. */
4038
4039void dlm_receive_message_saved(struct dlm_ls *ls, struct dlm_message *ms)
 
4040{
4041	_receive_message(ls, ms);
4042}
4043
4044/* This is called by the midcomms layer when something is received for
4045   the lockspace.  It could be either a MSG (normal message sent as part of
4046   standard locking activity) or an RCOM (recovery message sent as part of
4047   lockspace recovery). */
4048
4049void dlm_receive_buffer(union dlm_packet *p, int nodeid)
4050{
4051	struct dlm_header *hd = &p->header;
4052	struct dlm_ls *ls;
4053	int type = 0;
4054
4055	switch (hd->h_cmd) {
4056	case DLM_MSG:
4057		dlm_message_in(&p->message);
4058		type = p->message.m_type;
4059		break;
4060	case DLM_RCOM:
4061		dlm_rcom_in(&p->rcom);
4062		type = p->rcom.rc_type;
4063		break;
4064	default:
4065		log_print("invalid h_cmd %d from %u", hd->h_cmd, nodeid);
4066		return;
4067	}
4068
4069	if (hd->h_nodeid != nodeid) {
4070		log_print("invalid h_nodeid %d from %d lockspace %x",
4071			  hd->h_nodeid, nodeid, hd->h_lockspace);
4072		return;
4073	}
4074
4075	ls = dlm_find_lockspace_global(hd->h_lockspace);
4076	if (!ls) {
4077		if (dlm_config.ci_log_debug)
4078			log_print("invalid lockspace %x from %d cmd %d type %d",
4079				  hd->h_lockspace, nodeid, hd->h_cmd, type);
 
 
4080
4081		if (hd->h_cmd == DLM_RCOM && type == DLM_RCOM_STATUS)
4082			dlm_send_ls_not_ready(nodeid, &p->rcom);
4083		return;
4084	}
4085
4086	/* this rwsem allows dlm_ls_stop() to wait for all dlm_recv threads to
4087	   be inactive (in this ls) before transitioning to recovery mode */
4088
4089	down_read(&ls->ls_recv_active);
4090	if (hd->h_cmd == DLM_MSG)
4091		dlm_receive_message(ls, &p->message, nodeid);
4092	else
4093		dlm_receive_rcom(ls, &p->rcom, nodeid);
4094	up_read(&ls->ls_recv_active);
4095
4096	dlm_put_lockspace(ls);
4097}
4098
4099static void recover_convert_waiter(struct dlm_ls *ls, struct dlm_lkb *lkb,
4100				   struct dlm_message *ms_stub)
4101{
4102	if (middle_conversion(lkb)) {
4103		hold_lkb(lkb);
4104		memset(ms_stub, 0, sizeof(struct dlm_message));
4105		ms_stub->m_flags = DLM_IFL_STUB_MS;
4106		ms_stub->m_type = DLM_MSG_CONVERT_REPLY;
4107		ms_stub->m_result = -EINPROGRESS;
4108		ms_stub->m_header.h_nodeid = lkb->lkb_nodeid;
4109		_receive_convert_reply(lkb, ms_stub);
4110
4111		/* Same special case as in receive_rcom_lock_args() */
4112		lkb->lkb_grmode = DLM_LOCK_IV;
4113		rsb_set_flag(lkb->lkb_resource, RSB_RECOVER_CONVERT);
4114		unhold_lkb(lkb);
4115
4116	} else if (lkb->lkb_rqmode >= lkb->lkb_grmode) {
4117		lkb->lkb_flags |= DLM_IFL_RESEND;
4118	}
4119
4120	/* lkb->lkb_rqmode < lkb->lkb_grmode shouldn't happen since down
4121	   conversions are async; there's no reply from the remote master */
4122}
4123
4124/* A waiting lkb needs recovery if the master node has failed, or
4125   the master node is changing (only when no directory is used) */
4126
4127static int waiter_needs_recovery(struct dlm_ls *ls, struct dlm_lkb *lkb)
 
4128{
4129	if (dlm_is_removed(ls, lkb->lkb_nodeid))
4130		return 1;
4131
4132	if (!dlm_no_directory(ls))
4133		return 0;
4134
4135	if (dlm_dir_nodeid(lkb->lkb_resource) != lkb->lkb_nodeid)
4136		return 1;
4137
4138	return 0;
4139}
4140
4141/* Recovery for locks that are waiting for replies from nodes that are now
4142   gone.  We can just complete unlocks and cancels by faking a reply from the
4143   dead node.  Requests and up-conversions we flag to be resent after
4144   recovery.  Down-conversions can just be completed with a fake reply like
4145   unlocks.  Conversions between PR and CW need special attention. */
4146
4147void dlm_recover_waiters_pre(struct dlm_ls *ls)
4148{
4149	struct dlm_lkb *lkb, *safe;
4150	struct dlm_message *ms_stub;
4151	int wait_type, stub_unlock_result, stub_cancel_result;
 
4152
4153	ms_stub = kmalloc(sizeof(struct dlm_message), GFP_KERNEL);
4154	if (!ms_stub) {
4155		log_error(ls, "dlm_recover_waiters_pre no mem");
4156		return;
4157	}
4158
4159	mutex_lock(&ls->ls_waiters_mutex);
4160
4161	list_for_each_entry_safe(lkb, safe, &ls->ls_waiters, lkb_wait_reply) {
4162
 
 
4163		/* exclude debug messages about unlocks because there can be so
4164		   many and they aren't very interesting */
4165
4166		if (lkb->lkb_wait_type != DLM_MSG_UNLOCK) {
4167			log_debug(ls, "recover_waiter %x nodeid %d "
4168				  "msg %d to %d", lkb->lkb_id, lkb->lkb_nodeid,
4169				  lkb->lkb_wait_type, lkb->lkb_wait_nodeid);
 
 
 
 
 
 
4170		}
4171
4172		/* all outstanding lookups, regardless of destination  will be
4173		   resent after recovery is done */
4174
4175		if (lkb->lkb_wait_type == DLM_MSG_LOOKUP) {
4176			lkb->lkb_flags |= DLM_IFL_RESEND;
4177			continue;
4178		}
4179
4180		if (!waiter_needs_recovery(ls, lkb))
4181			continue;
4182
4183		wait_type = lkb->lkb_wait_type;
4184		stub_unlock_result = -DLM_EUNLOCK;
4185		stub_cancel_result = -DLM_ECANCEL;
4186
4187		/* Main reply may have been received leaving a zero wait_type,
4188		   but a reply for the overlapping op may not have been
4189		   received.  In that case we need to fake the appropriate
4190		   reply for the overlap op. */
4191
4192		if (!wait_type) {
4193			if (is_overlap_cancel(lkb)) {
4194				wait_type = DLM_MSG_CANCEL;
4195				if (lkb->lkb_grmode == DLM_LOCK_IV)
4196					stub_cancel_result = 0;
4197			}
4198			if (is_overlap_unlock(lkb)) {
4199				wait_type = DLM_MSG_UNLOCK;
4200				if (lkb->lkb_grmode == DLM_LOCK_IV)
4201					stub_unlock_result = -ENOENT;
4202			}
4203
4204			log_debug(ls, "rwpre overlap %x %x %d %d %d",
4205				  lkb->lkb_id, lkb->lkb_flags, wait_type,
4206				  stub_cancel_result, stub_unlock_result);
4207		}
4208
4209		switch (wait_type) {
4210
4211		case DLM_MSG_REQUEST:
4212			lkb->lkb_flags |= DLM_IFL_RESEND;
4213			break;
4214
4215		case DLM_MSG_CONVERT:
4216			recover_convert_waiter(ls, lkb, ms_stub);
4217			break;
4218
4219		case DLM_MSG_UNLOCK:
4220			hold_lkb(lkb);
4221			memset(ms_stub, 0, sizeof(struct dlm_message));
4222			ms_stub->m_flags = DLM_IFL_STUB_MS;
4223			ms_stub->m_type = DLM_MSG_UNLOCK_REPLY;
4224			ms_stub->m_result = stub_unlock_result;
4225			ms_stub->m_header.h_nodeid = lkb->lkb_nodeid;
4226			_receive_unlock_reply(lkb, ms_stub);
4227			dlm_put_lkb(lkb);
4228			break;
4229
4230		case DLM_MSG_CANCEL:
4231			hold_lkb(lkb);
4232			memset(ms_stub, 0, sizeof(struct dlm_message));
4233			ms_stub->m_flags = DLM_IFL_STUB_MS;
4234			ms_stub->m_type = DLM_MSG_CANCEL_REPLY;
4235			ms_stub->m_result = stub_cancel_result;
4236			ms_stub->m_header.h_nodeid = lkb->lkb_nodeid;
4237			_receive_cancel_reply(lkb, ms_stub);
4238			dlm_put_lkb(lkb);
4239			break;
4240
4241		default:
4242			log_error(ls, "invalid lkb wait_type %d %d",
4243				  lkb->lkb_wait_type, wait_type);
4244		}
4245		schedule();
4246	}
4247	mutex_unlock(&ls->ls_waiters_mutex);
4248	kfree(ms_stub);
4249}
4250
4251static struct dlm_lkb *find_resend_waiter(struct dlm_ls *ls)
4252{
4253	struct dlm_lkb *lkb;
4254	int found = 0;
4255
4256	mutex_lock(&ls->ls_waiters_mutex);
4257	list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
4258		if (lkb->lkb_flags & DLM_IFL_RESEND) {
4259			hold_lkb(lkb);
4260			found = 1;
4261			break;
4262		}
4263	}
4264	mutex_unlock(&ls->ls_waiters_mutex);
4265
4266	if (!found)
4267		lkb = NULL;
4268	return lkb;
4269}
4270
4271/* Deal with lookups and lkb's marked RESEND from _pre.  We may now be the
4272   master or dir-node for r.  Processing the lkb may result in it being placed
4273   back on waiters. */
4274
4275/* We do this after normal locking has been enabled and any saved messages
4276   (in requestqueue) have been processed.  We should be confident that at
4277   this point we won't get or process a reply to any of these waiting
4278   operations.  But, new ops may be coming in on the rsbs/locks here from
4279   userspace or remotely. */
4280
4281/* there may have been an overlap unlock/cancel prior to recovery or after
4282   recovery.  if before, the lkb may still have a pos wait_count; if after, the
4283   overlap flag would just have been set and nothing new sent.  we can be
4284   confident here than any replies to either the initial op or overlap ops
4285   prior to recovery have been received. */
4286
4287int dlm_recover_waiters_post(struct dlm_ls *ls)
4288{
4289	struct dlm_lkb *lkb;
4290	struct dlm_rsb *r;
4291	int error = 0, mstype, err, oc, ou;
4292
4293	while (1) {
4294		if (dlm_locking_stopped(ls)) {
4295			log_debug(ls, "recover_waiters_post aborted");
4296			error = -EINTR;
4297			break;
4298		}
4299
4300		lkb = find_resend_waiter(ls);
4301		if (!lkb)
4302			break;
4303
4304		r = lkb->lkb_resource;
4305		hold_rsb(r);
4306		lock_rsb(r);
4307
4308		mstype = lkb->lkb_wait_type;
4309		oc = is_overlap_cancel(lkb);
4310		ou = is_overlap_unlock(lkb);
4311		err = 0;
4312
4313		log_debug(ls, "recover_waiter %x nodeid %d msg %d r_nodeid %d",
4314			  lkb->lkb_id, lkb->lkb_nodeid, mstype, r->res_nodeid);
 
 
 
4315
4316		/* At this point we assume that we won't get a reply to any
4317		   previous op or overlap op on this lock.  First, do a big
4318		   remove_from_waiters() for all previous ops. */
4319
4320		lkb->lkb_flags &= ~DLM_IFL_RESEND;
4321		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
4322		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
4323		lkb->lkb_wait_type = 0;
4324		lkb->lkb_wait_count = 0;
4325		mutex_lock(&ls->ls_waiters_mutex);
4326		list_del_init(&lkb->lkb_wait_reply);
4327		mutex_unlock(&ls->ls_waiters_mutex);
4328		unhold_lkb(lkb); /* for waiters list */
4329
4330		if (oc || ou) {
4331			/* do an unlock or cancel instead of resending */
4332			switch (mstype) {
4333			case DLM_MSG_LOOKUP:
4334			case DLM_MSG_REQUEST:
4335				queue_cast(r, lkb, ou ? -DLM_EUNLOCK :
4336							-DLM_ECANCEL);
4337				unhold_lkb(lkb); /* undoes create_lkb() */
4338				break;
4339			case DLM_MSG_CONVERT:
4340				if (oc) {
4341					queue_cast(r, lkb, -DLM_ECANCEL);
4342				} else {
4343					lkb->lkb_exflags |= DLM_LKF_FORCEUNLOCK;
4344					_unlock_lock(r, lkb);
4345				}
4346				break;
4347			default:
4348				err = 1;
4349			}
4350		} else {
4351			switch (mstype) {
4352			case DLM_MSG_LOOKUP:
4353			case DLM_MSG_REQUEST:
4354				_request_lock(r, lkb);
4355				if (is_master(r))
4356					confirm_master(r, 0);
4357				break;
4358			case DLM_MSG_CONVERT:
4359				_convert_lock(r, lkb);
4360				break;
4361			default:
4362				err = 1;
4363			}
4364		}
4365
4366		if (err)
4367			log_error(ls, "recover_waiters_post %x %d %x %d %d",
4368			  	  lkb->lkb_id, mstype, lkb->lkb_flags, oc, ou);
 
 
 
4369		unlock_rsb(r);
4370		put_rsb(r);
4371		dlm_put_lkb(lkb);
4372	}
4373
4374	return error;
4375}
4376
4377static void purge_queue(struct dlm_rsb *r, struct list_head *queue,
4378			int (*test)(struct dlm_ls *ls, struct dlm_lkb *lkb))
4379{
4380	struct dlm_ls *ls = r->res_ls;
4381	struct dlm_lkb *lkb, *safe;
4382
4383	list_for_each_entry_safe(lkb, safe, queue, lkb_statequeue) {
4384		if (test(ls, lkb)) {
4385			rsb_set_flag(r, RSB_LOCKS_PURGED);
4386			del_lkb(r, lkb);
4387			/* this put should free the lkb */
4388			if (!dlm_put_lkb(lkb))
4389				log_error(ls, "purged lkb not released");
4390		}
 
 
 
 
 
 
 
4391	}
4392}
4393
4394static int purge_dead_test(struct dlm_ls *ls, struct dlm_lkb *lkb)
4395{
4396	return (is_master_copy(lkb) && dlm_is_removed(ls, lkb->lkb_nodeid));
4397}
4398
4399static int purge_mstcpy_test(struct dlm_ls *ls, struct dlm_lkb *lkb)
4400{
4401	return is_master_copy(lkb);
4402}
4403
4404static void purge_dead_locks(struct dlm_rsb *r)
 
 
4405{
4406	purge_queue(r, &r->res_grantqueue, &purge_dead_test);
4407	purge_queue(r, &r->res_convertqueue, &purge_dead_test);
4408	purge_queue(r, &r->res_waitqueue, &purge_dead_test);
4409}
4410
4411void dlm_purge_mstcpy_locks(struct dlm_rsb *r)
4412{
4413	purge_queue(r, &r->res_grantqueue, &purge_mstcpy_test);
4414	purge_queue(r, &r->res_convertqueue, &purge_mstcpy_test);
4415	purge_queue(r, &r->res_waitqueue, &purge_mstcpy_test);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4416}
4417
4418/* Get rid of locks held by nodes that are gone. */
4419
4420int dlm_purge_locks(struct dlm_ls *ls)
4421{
4422	struct dlm_rsb *r;
 
 
 
 
 
 
 
 
 
 
 
 
4423
4424	log_debug(ls, "dlm_purge_locks");
 
4425
4426	down_write(&ls->ls_root_sem);
4427	list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
4428		hold_rsb(r);
4429		lock_rsb(r);
4430		if (is_master(r))
4431			purge_dead_locks(r);
 
 
 
 
 
 
4432		unlock_rsb(r);
4433		unhold_rsb(r);
4434
4435		schedule();
4436	}
4437	up_write(&ls->ls_root_sem);
4438
4439	return 0;
 
 
4440}
4441
4442static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket)
4443{
4444	struct dlm_rsb *r, *r_ret = NULL;
 
4445
4446	spin_lock(&ls->ls_rsbtbl[bucket].lock);
4447	list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list, res_hashchain) {
4448		if (!rsb_flag(r, RSB_LOCKS_PURGED))
 
 
 
 
 
4449			continue;
 
4450		hold_rsb(r);
4451		rsb_clear_flag(r, RSB_LOCKS_PURGED);
4452		r_ret = r;
4453		break;
4454	}
4455	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
4456	return r_ret;
4457}
4458
4459void dlm_grant_after_purge(struct dlm_ls *ls)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4460{
4461	struct dlm_rsb *r;
4462	int bucket = 0;
 
 
 
4463
4464	while (1) {
4465		r = find_purged_rsb(ls, bucket);
4466		if (!r) {
4467			if (bucket == ls->ls_rsbtbl_size - 1)
4468				break;
4469			bucket++;
4470			continue;
4471		}
 
 
4472		lock_rsb(r);
4473		if (is_master(r)) {
4474			grant_pending_locks(r);
4475			confirm_master(r, 0);
4476		}
 
4477		unlock_rsb(r);
4478		put_rsb(r);
4479		schedule();
4480	}
 
 
 
 
4481}
4482
4483static struct dlm_lkb *search_remid_list(struct list_head *head, int nodeid,
4484					 uint32_t remid)
4485{
4486	struct dlm_lkb *lkb;
4487
4488	list_for_each_entry(lkb, head, lkb_statequeue) {
4489		if (lkb->lkb_nodeid == nodeid && lkb->lkb_remid == remid)
4490			return lkb;
4491	}
4492	return NULL;
4493}
4494
4495static struct dlm_lkb *search_remid(struct dlm_rsb *r, int nodeid,
4496				    uint32_t remid)
4497{
4498	struct dlm_lkb *lkb;
4499
4500	lkb = search_remid_list(&r->res_grantqueue, nodeid, remid);
4501	if (lkb)
4502		return lkb;
4503	lkb = search_remid_list(&r->res_convertqueue, nodeid, remid);
4504	if (lkb)
4505		return lkb;
4506	lkb = search_remid_list(&r->res_waitqueue, nodeid, remid);
4507	if (lkb)
4508		return lkb;
4509	return NULL;
4510}
4511
4512/* needs at least dlm_rcom + rcom_lock */
4513static int receive_rcom_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
4514				  struct dlm_rsb *r, struct dlm_rcom *rc)
4515{
4516	struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
4517
4518	lkb->lkb_nodeid = rc->rc_header.h_nodeid;
4519	lkb->lkb_ownpid = le32_to_cpu(rl->rl_ownpid);
4520	lkb->lkb_remid = le32_to_cpu(rl->rl_lkid);
4521	lkb->lkb_exflags = le32_to_cpu(rl->rl_exflags);
4522	lkb->lkb_flags = le32_to_cpu(rl->rl_flags) & 0x0000FFFF;
4523	lkb->lkb_flags |= DLM_IFL_MSTCPY;
4524	lkb->lkb_lvbseq = le32_to_cpu(rl->rl_lvbseq);
4525	lkb->lkb_rqmode = rl->rl_rqmode;
4526	lkb->lkb_grmode = rl->rl_grmode;
4527	/* don't set lkb_status because add_lkb wants to itself */
4528
4529	lkb->lkb_bastfn = (rl->rl_asts & DLM_CB_BAST) ? &fake_bastfn : NULL;
4530	lkb->lkb_astfn = (rl->rl_asts & DLM_CB_CAST) ? &fake_astfn : NULL;
4531
4532	if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
4533		int lvblen = rc->rc_header.h_length - sizeof(struct dlm_rcom) -
4534			 sizeof(struct rcom_lock);
4535		if (lvblen > ls->ls_lvblen)
4536			return -EINVAL;
4537		lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
4538		if (!lkb->lkb_lvbptr)
4539			return -ENOMEM;
4540		memcpy(lkb->lkb_lvbptr, rl->rl_lvb, lvblen);
4541	}
4542
4543	/* Conversions between PR and CW (middle modes) need special handling.
4544	   The real granted mode of these converting locks cannot be determined
4545	   until all locks have been rebuilt on the rsb (recover_conversion) */
4546
4547	if (rl->rl_wait_type == cpu_to_le16(DLM_MSG_CONVERT) &&
4548	    middle_conversion(lkb)) {
4549		rl->rl_status = DLM_LKSTS_CONVERT;
4550		lkb->lkb_grmode = DLM_LOCK_IV;
4551		rsb_set_flag(r, RSB_RECOVER_CONVERT);
4552	}
4553
4554	return 0;
4555}
4556
4557/* This lkb may have been recovered in a previous aborted recovery so we need
4558   to check if the rsb already has an lkb with the given remote nodeid/lkid.
4559   If so we just send back a standard reply.  If not, we create a new lkb with
4560   the given values and send back our lkid.  We send back our lkid by sending
4561   back the rcom_lock struct we got but with the remid field filled in. */
4562
4563/* needs at least dlm_rcom + rcom_lock */
4564int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
4565{
4566	struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
4567	struct dlm_rsb *r;
4568	struct dlm_lkb *lkb;
 
 
4569	int error;
4570
4571	if (rl->rl_parent_lkid) {
4572		error = -EOPNOTSUPP;
4573		goto out;
4574	}
4575
 
 
 
 
 
 
 
 
 
 
4576	error = find_rsb(ls, rl->rl_name, le16_to_cpu(rl->rl_namelen),
4577			 R_MASTER, &r);
4578	if (error)
4579		goto out;
4580
4581	lock_rsb(r);
4582
4583	lkb = search_remid(r, rc->rc_header.h_nodeid, le32_to_cpu(rl->rl_lkid));
 
 
 
 
 
 
 
4584	if (lkb) {
4585		error = -EEXIST;
4586		goto out_remid;
4587	}
4588
4589	error = create_lkb(ls, &lkb);
4590	if (error)
4591		goto out_unlock;
4592
4593	error = receive_rcom_lock_args(ls, lkb, r, rc);
4594	if (error) {
4595		__put_lkb(ls, lkb);
4596		goto out_unlock;
4597	}
4598
4599	attach_lkb(r, lkb);
4600	add_lkb(r, lkb, rl->rl_status);
4601	error = 0;
 
 
 
 
4602
4603 out_remid:
4604	/* this is the new value returned to the lock holder for
4605	   saving in its process-copy lkb */
4606	rl->rl_remid = cpu_to_le32(lkb->lkb_id);
4607
 
 
4608 out_unlock:
4609	unlock_rsb(r);
4610	put_rsb(r);
4611 out:
4612	if (error)
4613		log_debug(ls, "recover_master_copy %d %x", error,
4614			  le32_to_cpu(rl->rl_lkid));
4615	rl->rl_result = cpu_to_le32(error);
4616	return error;
4617}
4618
4619/* needs at least dlm_rcom + rcom_lock */
4620int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
4621{
4622	struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
4623	struct dlm_rsb *r;
4624	struct dlm_lkb *lkb;
4625	int error;
 
 
 
 
 
4626
4627	error = find_lkb(ls, le32_to_cpu(rl->rl_lkid), &lkb);
4628	if (error) {
4629		log_error(ls, "recover_process_copy no lkid %x",
4630				le32_to_cpu(rl->rl_lkid));
4631		return error;
4632	}
4633
4634	DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
4635
4636	error = le32_to_cpu(rl->rl_result);
4637
4638	r = lkb->lkb_resource;
4639	hold_rsb(r);
4640	lock_rsb(r);
4641
4642	switch (error) {
 
 
 
 
 
 
 
 
 
 
4643	case -EBADR:
4644		/* There's a chance the new master received our lock before
4645		   dlm_recover_master_reply(), this wouldn't happen if we did
4646		   a barrier between recover_masters and recover_locks. */
4647		log_debug(ls, "master copy not ready %x r %lx %s", lkb->lkb_id,
4648			  (unsigned long)r, r->res_name);
 
 
4649		dlm_send_rcom_lock(r, lkb);
4650		goto out;
4651	case -EEXIST:
4652		log_debug(ls, "master copy exists %x", lkb->lkb_id);
4653		/* fall through */
4654	case 0:
4655		lkb->lkb_remid = le32_to_cpu(rl->rl_remid);
4656		break;
4657	default:
4658		log_error(ls, "dlm_recover_process_copy unknown error %d %x",
4659			  error, lkb->lkb_id);
4660	}
4661
4662	/* an ack for dlm_recover_locks() which waits for replies from
4663	   all the locks it sends to new masters */
4664	dlm_recovered_lock(r);
4665 out:
4666	unlock_rsb(r);
4667	put_rsb(r);
4668	dlm_put_lkb(lkb);
4669
4670	return 0;
4671}
4672
4673int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua,
4674		     int mode, uint32_t flags, void *name, unsigned int namelen,
4675		     unsigned long timeout_cs)
4676{
4677	struct dlm_lkb *lkb;
4678	struct dlm_args args;
4679	int error;
4680
4681	dlm_lock_recovery(ls);
4682
4683	error = create_lkb(ls, &lkb);
4684	if (error) {
4685		kfree(ua);
4686		goto out;
4687	}
4688
4689	if (flags & DLM_LKF_VALBLK) {
4690		ua->lksb.sb_lvbptr = kzalloc(DLM_USER_LVB_LEN, GFP_NOFS);
4691		if (!ua->lksb.sb_lvbptr) {
4692			kfree(ua);
4693			__put_lkb(ls, lkb);
4694			error = -ENOMEM;
4695			goto out;
4696		}
4697	}
4698
4699	/* After ua is attached to lkb it will be freed by dlm_free_lkb().
4700	   When DLM_IFL_USER is set, the dlm knows that this is a userspace
4701	   lock and that lkb_astparam is the dlm_user_args structure. */
4702
4703	error = set_lock_args(mode, &ua->lksb, flags, namelen, timeout_cs,
4704			      fake_astfn, ua, fake_bastfn, &args);
4705	lkb->lkb_flags |= DLM_IFL_USER;
4706
4707	if (error) {
 
 
 
4708		__put_lkb(ls, lkb);
4709		goto out;
4710	}
4711
 
 
 
 
4712	error = request_lock(ls, lkb, name, namelen, &args);
4713
4714	switch (error) {
4715	case 0:
4716		break;
4717	case -EINPROGRESS:
4718		error = 0;
4719		break;
4720	case -EAGAIN:
4721		error = 0;
4722		/* fall through */
4723	default:
4724		__put_lkb(ls, lkb);
4725		goto out;
4726	}
4727
4728	/* add this new lkb to the per-process list of locks */
4729	spin_lock(&ua->proc->locks_spin);
4730	hold_lkb(lkb);
4731	list_add_tail(&lkb->lkb_ownqueue, &ua->proc->locks);
4732	spin_unlock(&ua->proc->locks_spin);
4733 out:
4734	dlm_unlock_recovery(ls);
4735	return error;
4736}
4737
4738int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
4739		     int mode, uint32_t flags, uint32_t lkid, char *lvb_in,
4740		     unsigned long timeout_cs)
4741{
4742	struct dlm_lkb *lkb;
4743	struct dlm_args args;
4744	struct dlm_user_args *ua;
4745	int error;
4746
4747	dlm_lock_recovery(ls);
4748
4749	error = find_lkb(ls, lkid, &lkb);
4750	if (error)
4751		goto out;
4752
4753	/* user can change the params on its lock when it converts it, or
4754	   add an lvb that didn't exist before */
4755
4756	ua = lkb->lkb_ua;
4757
4758	if (flags & DLM_LKF_VALBLK && !ua->lksb.sb_lvbptr) {
4759		ua->lksb.sb_lvbptr = kzalloc(DLM_USER_LVB_LEN, GFP_NOFS);
4760		if (!ua->lksb.sb_lvbptr) {
4761			error = -ENOMEM;
4762			goto out_put;
4763		}
4764	}
4765	if (lvb_in && ua->lksb.sb_lvbptr)
4766		memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);
4767
4768	ua->xid = ua_tmp->xid;
4769	ua->castparam = ua_tmp->castparam;
4770	ua->castaddr = ua_tmp->castaddr;
4771	ua->bastparam = ua_tmp->bastparam;
4772	ua->bastaddr = ua_tmp->bastaddr;
4773	ua->user_lksb = ua_tmp->user_lksb;
4774
4775	error = set_lock_args(mode, &ua->lksb, flags, 0, timeout_cs,
4776			      fake_astfn, ua, fake_bastfn, &args);
4777	if (error)
4778		goto out_put;
4779
4780	error = convert_lock(ls, lkb, &args);
4781
4782	if (error == -EINPROGRESS || error == -EAGAIN || error == -EDEADLK)
4783		error = 0;
4784 out_put:
4785	dlm_put_lkb(lkb);
4786 out:
4787	dlm_unlock_recovery(ls);
4788	kfree(ua_tmp);
4789	return error;
4790}
4791
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4792int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
4793		    uint32_t flags, uint32_t lkid, char *lvb_in)
4794{
4795	struct dlm_lkb *lkb;
4796	struct dlm_args args;
4797	struct dlm_user_args *ua;
4798	int error;
4799
4800	dlm_lock_recovery(ls);
4801
4802	error = find_lkb(ls, lkid, &lkb);
4803	if (error)
4804		goto out;
4805
4806	ua = lkb->lkb_ua;
4807
4808	if (lvb_in && ua->lksb.sb_lvbptr)
4809		memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);
4810	if (ua_tmp->castparam)
4811		ua->castparam = ua_tmp->castparam;
4812	ua->user_lksb = ua_tmp->user_lksb;
4813
4814	error = set_unlock_args(flags, ua, &args);
4815	if (error)
4816		goto out_put;
4817
4818	error = unlock_lock(ls, lkb, &args);
4819
4820	if (error == -DLM_EUNLOCK)
4821		error = 0;
4822	/* from validate_unlock_args() */
4823	if (error == -EBUSY && (flags & DLM_LKF_FORCEUNLOCK))
4824		error = 0;
4825	if (error)
4826		goto out_put;
4827
4828	spin_lock(&ua->proc->locks_spin);
4829	/* dlm_user_add_cb() may have already taken lkb off the proc list */
4830	if (!list_empty(&lkb->lkb_ownqueue))
4831		list_move(&lkb->lkb_ownqueue, &ua->proc->unlocking);
4832	spin_unlock(&ua->proc->locks_spin);
4833 out_put:
4834	dlm_put_lkb(lkb);
4835 out:
4836	dlm_unlock_recovery(ls);
4837	kfree(ua_tmp);
4838	return error;
4839}
4840
4841int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
4842		    uint32_t flags, uint32_t lkid)
4843{
4844	struct dlm_lkb *lkb;
4845	struct dlm_args args;
4846	struct dlm_user_args *ua;
4847	int error;
4848
4849	dlm_lock_recovery(ls);
4850
4851	error = find_lkb(ls, lkid, &lkb);
4852	if (error)
4853		goto out;
4854
4855	ua = lkb->lkb_ua;
4856	if (ua_tmp->castparam)
4857		ua->castparam = ua_tmp->castparam;
4858	ua->user_lksb = ua_tmp->user_lksb;
4859
4860	error = set_unlock_args(flags, ua, &args);
4861	if (error)
4862		goto out_put;
4863
4864	error = cancel_lock(ls, lkb, &args);
4865
4866	if (error == -DLM_ECANCEL)
4867		error = 0;
4868	/* from validate_unlock_args() */
4869	if (error == -EBUSY)
4870		error = 0;
4871 out_put:
4872	dlm_put_lkb(lkb);
4873 out:
4874	dlm_unlock_recovery(ls);
4875	kfree(ua_tmp);
4876	return error;
4877}
4878
4879int dlm_user_deadlock(struct dlm_ls *ls, uint32_t flags, uint32_t lkid)
4880{
4881	struct dlm_lkb *lkb;
4882	struct dlm_args args;
4883	struct dlm_user_args *ua;
4884	struct dlm_rsb *r;
4885	int error;
4886
4887	dlm_lock_recovery(ls);
4888
4889	error = find_lkb(ls, lkid, &lkb);
4890	if (error)
4891		goto out;
4892
4893	ua = lkb->lkb_ua;
4894
4895	error = set_unlock_args(flags, ua, &args);
4896	if (error)
4897		goto out_put;
4898
4899	/* same as cancel_lock(), but set DEADLOCK_CANCEL after lock_rsb */
4900
4901	r = lkb->lkb_resource;
4902	hold_rsb(r);
4903	lock_rsb(r);
4904
4905	error = validate_unlock_args(lkb, &args);
4906	if (error)
4907		goto out_r;
4908	lkb->lkb_flags |= DLM_IFL_DEADLOCK_CANCEL;
4909
4910	error = _cancel_lock(r, lkb);
4911 out_r:
4912	unlock_rsb(r);
4913	put_rsb(r);
4914
4915	if (error == -DLM_ECANCEL)
4916		error = 0;
4917	/* from validate_unlock_args() */
4918	if (error == -EBUSY)
4919		error = 0;
4920 out_put:
4921	dlm_put_lkb(lkb);
4922 out:
4923	dlm_unlock_recovery(ls);
4924	return error;
4925}
4926
4927/* lkb's that are removed from the waiters list by revert are just left on the
4928   orphans list with the granted orphan locks, to be freed by purge */
4929
4930static int orphan_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
4931{
4932	struct dlm_args args;
4933	int error;
4934
4935	hold_lkb(lkb);
4936	mutex_lock(&ls->ls_orphans_mutex);
4937	list_add_tail(&lkb->lkb_ownqueue, &ls->ls_orphans);
4938	mutex_unlock(&ls->ls_orphans_mutex);
4939
4940	set_unlock_args(0, lkb->lkb_ua, &args);
4941
4942	error = cancel_lock(ls, lkb, &args);
4943	if (error == -DLM_ECANCEL)
4944		error = 0;
4945	return error;
4946}
4947
4948/* The force flag allows the unlock to go ahead even if the lkb isn't granted.
4949   Regardless of what rsb queue the lock is on, it's removed and freed. */
 
 
4950
4951static int unlock_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
4952{
4953	struct dlm_args args;
4954	int error;
4955
4956	set_unlock_args(DLM_LKF_FORCEUNLOCK, lkb->lkb_ua, &args);
 
4957
4958	error = unlock_lock(ls, lkb, &args);
4959	if (error == -DLM_EUNLOCK)
4960		error = 0;
4961	return error;
4962}
4963
4964/* We have to release clear_proc_locks mutex before calling unlock_proc_lock()
4965   (which does lock_rsb) due to deadlock with receiving a message that does
4966   lock_rsb followed by dlm_user_add_cb() */
4967
4968static struct dlm_lkb *del_proc_lock(struct dlm_ls *ls,
4969				     struct dlm_user_proc *proc)
4970{
4971	struct dlm_lkb *lkb = NULL;
4972
4973	mutex_lock(&ls->ls_clear_proc_locks);
4974	if (list_empty(&proc->locks))
4975		goto out;
4976
4977	lkb = list_entry(proc->locks.next, struct dlm_lkb, lkb_ownqueue);
4978	list_del_init(&lkb->lkb_ownqueue);
4979
4980	if (lkb->lkb_exflags & DLM_LKF_PERSISTENT)
4981		lkb->lkb_flags |= DLM_IFL_ORPHAN;
4982	else
4983		lkb->lkb_flags |= DLM_IFL_DEAD;
4984 out:
4985	mutex_unlock(&ls->ls_clear_proc_locks);
4986	return lkb;
4987}
4988
4989/* The ls_clear_proc_locks mutex protects against dlm_user_add_cb() which
4990   1) references lkb->ua which we free here and 2) adds lkbs to proc->asts,
4991   which we clear here. */
4992
4993/* proc CLOSING flag is set so no more device_reads should look at proc->asts
4994   list, and no more device_writes should add lkb's to proc->locks list; so we
4995   shouldn't need to take asts_spin or locks_spin here.  this assumes that
4996   device reads/writes/closes are serialized -- FIXME: we may need to serialize
4997   them ourself. */
4998
4999void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc)
5000{
5001	struct dlm_lkb *lkb, *safe;
5002
5003	dlm_lock_recovery(ls);
5004
5005	while (1) {
5006		lkb = del_proc_lock(ls, proc);
5007		if (!lkb)
5008			break;
5009		del_timeout(lkb);
5010		if (lkb->lkb_exflags & DLM_LKF_PERSISTENT)
5011			orphan_proc_lock(ls, lkb);
5012		else
5013			unlock_proc_lock(ls, lkb);
5014
5015		/* this removes the reference for the proc->locks list
5016		   added by dlm_user_request, it may result in the lkb
5017		   being freed */
5018
5019		dlm_put_lkb(lkb);
5020	}
5021
5022	mutex_lock(&ls->ls_clear_proc_locks);
5023
5024	/* in-progress unlocks */
5025	list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) {
5026		list_del_init(&lkb->lkb_ownqueue);
5027		lkb->lkb_flags |= DLM_IFL_DEAD;
5028		dlm_put_lkb(lkb);
5029	}
5030
5031	list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_cb_list) {
5032		memset(&lkb->lkb_callbacks, 0,
5033		       sizeof(struct dlm_callback) * DLM_CALLBACKS_SIZE);
5034		list_del_init(&lkb->lkb_cb_list);
5035		dlm_put_lkb(lkb);
5036	}
5037
5038	mutex_unlock(&ls->ls_clear_proc_locks);
5039	dlm_unlock_recovery(ls);
5040}
5041
5042static void purge_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc)
5043{
5044	struct dlm_lkb *lkb, *safe;
5045
5046	while (1) {
5047		lkb = NULL;
5048		spin_lock(&proc->locks_spin);
5049		if (!list_empty(&proc->locks)) {
5050			lkb = list_entry(proc->locks.next, struct dlm_lkb,
5051					 lkb_ownqueue);
5052			list_del_init(&lkb->lkb_ownqueue);
5053		}
5054		spin_unlock(&proc->locks_spin);
5055
5056		if (!lkb)
5057			break;
5058
5059		lkb->lkb_flags |= DLM_IFL_DEAD;
5060		unlock_proc_lock(ls, lkb);
5061		dlm_put_lkb(lkb); /* ref from proc->locks list */
5062	}
5063
5064	spin_lock(&proc->locks_spin);
5065	list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) {
5066		list_del_init(&lkb->lkb_ownqueue);
5067		lkb->lkb_flags |= DLM_IFL_DEAD;
5068		dlm_put_lkb(lkb);
5069	}
5070	spin_unlock(&proc->locks_spin);
5071
5072	spin_lock(&proc->asts_spin);
5073	list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_cb_list) {
5074		memset(&lkb->lkb_callbacks, 0,
5075		       sizeof(struct dlm_callback) * DLM_CALLBACKS_SIZE);
5076		list_del_init(&lkb->lkb_cb_list);
5077		dlm_put_lkb(lkb);
5078	}
5079	spin_unlock(&proc->asts_spin);
5080}
5081
5082/* pid of 0 means purge all orphans */
5083
5084static void do_purge(struct dlm_ls *ls, int nodeid, int pid)
5085{
5086	struct dlm_lkb *lkb, *safe;
5087
5088	mutex_lock(&ls->ls_orphans_mutex);
5089	list_for_each_entry_safe(lkb, safe, &ls->ls_orphans, lkb_ownqueue) {
5090		if (pid && lkb->lkb_ownpid != pid)
5091			continue;
5092		unlock_proc_lock(ls, lkb);
5093		list_del_init(&lkb->lkb_ownqueue);
5094		dlm_put_lkb(lkb);
5095	}
5096	mutex_unlock(&ls->ls_orphans_mutex);
5097}
5098
5099static int send_purge(struct dlm_ls *ls, int nodeid, int pid)
5100{
5101	struct dlm_message *ms;
5102	struct dlm_mhandle *mh;
5103	int error;
5104
5105	error = _create_message(ls, sizeof(struct dlm_message), nodeid,
5106				DLM_MSG_PURGE, &ms, &mh);
5107	if (error)
5108		return error;
5109	ms->m_nodeid = nodeid;
5110	ms->m_pid = pid;
5111
5112	return send_message(mh, ms);
5113}
5114
5115int dlm_user_purge(struct dlm_ls *ls, struct dlm_user_proc *proc,
5116		   int nodeid, int pid)
5117{
5118	int error = 0;
5119
5120	if (nodeid != dlm_our_nodeid()) {
5121		error = send_purge(ls, nodeid, pid);
5122	} else {
5123		dlm_lock_recovery(ls);
5124		if (pid == current->pid)
5125			purge_proc_locks(ls, proc);
5126		else
5127			do_purge(ls, nodeid, pid);
5128		dlm_unlock_recovery(ls);
5129	}
5130	return error;
5131}
5132