dlmglue.c 83 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * dlmglue.c
 *
 * Code which implements an OCFS2 specific interface to our DLM.
 *
 * Copyright (C) 2003, 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/crc32.h>
#include <linux/kthread.h>
#include <linux/pagemap.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>

#include <cluster/heartbeat.h>
#include <cluster/nodemanager.h>
#include <cluster/tcp.h>

#include <dlm/dlmapi.h>

#define MLOG_MASK_PREFIX ML_DLM_GLUE
#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
49
#include "dcache.h"
50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72
#include "dlmglue.h"
#include "extent_map.h"
#include "heartbeat.h"
#include "inode.h"
#include "journal.h"
#include "slot_map.h"
#include "super.h"
#include "uptodate.h"
#include "vote.h"

#include "buffer_head_io.h"

struct ocfs2_mask_waiter {
	struct list_head	mw_item;
	int			mw_status;
	struct completion	mw_complete;
	unsigned long		mw_mask;
	unsigned long		mw_goal;
};

static void ocfs2_inode_ast_func(void *opaque);
static void ocfs2_inode_bast_func(void *opaque,
				  int level);
73 74 75
static void ocfs2_dentry_ast_func(void *opaque);
static void ocfs2_dentry_bast_func(void *opaque,
				  int level);
76 77 78 79 80 81 82
static void ocfs2_super_ast_func(void *opaque);
static void ocfs2_super_bast_func(void *opaque,
				  int level);
static void ocfs2_rename_ast_func(void *opaque);
static void ocfs2_rename_bast_func(void *opaque,
				   int level);

83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102
/*
 * Return value from ocfs2_convert_worker_t functions.
 *
 * These control the precise actions of ocfs2_generic_unblock_lock()
 * and ocfs2_process_blocked_lock()
 *
 */
enum ocfs2_unblock_action {
	UNBLOCK_CONTINUE	= 0, /* Continue downconvert */
	UNBLOCK_CONTINUE_POST	= 1, /* Continue downconvert, fire
				      * ->post_unlock callback */
	UNBLOCK_STOP_POST	= 2, /* Do not downconvert, fire
				      * ->post_unlock() callback. */
};

struct ocfs2_unblock_ctl {
	int requeue;
	enum ocfs2_unblock_action unblock_action;
};

103 104 105 106
/* so far, all locks have gotten along with the same unlock ast */
static void ocfs2_unlock_ast_func(void *opaque,
				  enum dlm_status status);
static int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres,
107
			      struct ocfs2_unblock_ctl *ctl);
108
static int ocfs2_unblock_data(struct ocfs2_lock_res *lockres,
109
			      struct ocfs2_unblock_ctl *ctl);
110
static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres,
111 112 113
				    struct ocfs2_unblock_ctl *ctl);
static int ocfs2_unblock_dentry_lock(struct ocfs2_lock_res *lockres,
				     struct ocfs2_unblock_ctl *ctl);
114
static int ocfs2_unblock_osb_lock(struct ocfs2_lock_res *lockres,
115 116 117 118
				  struct ocfs2_unblock_ctl *ctl);

static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
				     struct ocfs2_lock_res *lockres);
119 120 121 122 123

struct ocfs2_lock_res_ops {
	void (*ast)(void *);
	void (*bast)(void *, int);
	void (*unlock_ast)(void *, enum dlm_status);
124 125
	int  (*unblock)(struct ocfs2_lock_res *, struct ocfs2_unblock_ctl *);
	void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *);
126 127
};

128 129 130 131 132 133
typedef int (ocfs2_convert_worker_t)(struct ocfs2_lock_res *, int);
static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb,
				      struct ocfs2_lock_res *lockres,
				      struct ocfs2_unblock_ctl *ctl,
				      ocfs2_convert_worker_t *worker);

134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168
static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
	.ast		= ocfs2_inode_ast_func,
	.bast		= ocfs2_inode_bast_func,
	.unlock_ast	= ocfs2_unlock_ast_func,
	.unblock	= ocfs2_unblock_inode_lock,
};

static struct ocfs2_lock_res_ops ocfs2_inode_meta_lops = {
	.ast		= ocfs2_inode_ast_func,
	.bast		= ocfs2_inode_bast_func,
	.unlock_ast	= ocfs2_unlock_ast_func,
	.unblock	= ocfs2_unblock_meta,
};

static struct ocfs2_lock_res_ops ocfs2_inode_data_lops = {
	.ast		= ocfs2_inode_ast_func,
	.bast		= ocfs2_inode_bast_func,
	.unlock_ast	= ocfs2_unlock_ast_func,
	.unblock	= ocfs2_unblock_data,
};

static struct ocfs2_lock_res_ops ocfs2_super_lops = {
	.ast		= ocfs2_super_ast_func,
	.bast		= ocfs2_super_bast_func,
	.unlock_ast	= ocfs2_unlock_ast_func,
	.unblock	= ocfs2_unblock_osb_lock,
};

static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
	.ast		= ocfs2_rename_ast_func,
	.bast		= ocfs2_rename_bast_func,
	.unlock_ast	= ocfs2_unlock_ast_func,
	.unblock	= ocfs2_unblock_osb_lock,
};

169 170 171 172 173 174 175 176
static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
	.ast		= ocfs2_dentry_ast_func,
	.bast		= ocfs2_dentry_bast_func,
	.unlock_ast	= ocfs2_unlock_ast_func,
	.unblock	= ocfs2_unblock_dentry_lock,
	.post_unlock	= ocfs2_dentry_post_unlock,
};

177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208
static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
{
	return lockres->l_type == OCFS2_LOCK_TYPE_META ||
		lockres->l_type == OCFS2_LOCK_TYPE_DATA ||
		lockres->l_type == OCFS2_LOCK_TYPE_RW;
}

static inline int ocfs2_is_super_lock(struct ocfs2_lock_res *lockres)
{
	return lockres->l_type == OCFS2_LOCK_TYPE_SUPER;
}

static inline int ocfs2_is_rename_lock(struct ocfs2_lock_res *lockres)
{
	return lockres->l_type == OCFS2_LOCK_TYPE_RENAME;
}

static inline struct ocfs2_super *ocfs2_lock_res_super(struct ocfs2_lock_res *lockres)
{
	BUG_ON(!ocfs2_is_super_lock(lockres)
	       && !ocfs2_is_rename_lock(lockres));

	return (struct ocfs2_super *) lockres->l_priv;
}

static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
{
	BUG_ON(!ocfs2_is_inode_lock(lockres));

	return (struct inode *) lockres->l_priv;
}

209 210 211 212 213 214 215
static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres)
{
	BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY);

	return (struct ocfs2_dentry_lock *)lockres->l_priv;
}

216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258
static int ocfs2_lock_create(struct ocfs2_super *osb,
			     struct ocfs2_lock_res *lockres,
			     int level,
			     int dlm_flags);
static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
						     int wanted);
static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
				 struct ocfs2_lock_res *lockres,
				 int level);
static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres);
static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres);
static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres);
static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level);
static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
					struct ocfs2_lock_res *lockres);
static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
						int convert);
#define ocfs2_log_dlm_error(_func, _stat, _lockres) do {	\
	mlog(ML_ERROR, "Dlm error \"%s\" while calling %s on "	\
		"resource %s: %s\n", dlm_errname(_stat), _func,	\
		_lockres->l_name, dlm_errmsg(_stat));		\
} while (0)
static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
				 struct ocfs2_lock_res *lockres);
static int ocfs2_meta_lock_update(struct inode *inode,
				  struct buffer_head **bh);
static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
static inline int ocfs2_highest_compat_lock_level(int level);
static inline int ocfs2_can_downconvert_meta_lock(struct inode *inode,
						  struct ocfs2_lock_res *lockres,
						  int new_level);

static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
				  u64 blkno,
				  u32 generation,
				  char *name)
{
	int len;

	mlog_entry_void();

	BUG_ON(type >= OCFS2_NUM_LOCK_TYPES);

259 260 261
	len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016llx%08x",
		       ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD,
		       (long long)blkno, generation);
262 263 264 265 266 267 268 269

	BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1));

	mlog(0, "built lock resource with name: %s\n", name);

	mlog_exit_void();
}

270
static DEFINE_SPINLOCK(ocfs2_dlm_tracking_lock);
271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342

static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res,
				       struct ocfs2_dlm_debug *dlm_debug)
{
	mlog(0, "Add tracking for lockres %s\n", res->l_name);

	spin_lock(&ocfs2_dlm_tracking_lock);
	list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking);
	spin_unlock(&ocfs2_dlm_tracking_lock);
}

static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res)
{
	spin_lock(&ocfs2_dlm_tracking_lock);
	if (!list_empty(&res->l_debug_list))
		list_del_init(&res->l_debug_list);
	spin_unlock(&ocfs2_dlm_tracking_lock);
}

static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
				       struct ocfs2_lock_res *res,
				       enum ocfs2_lock_type type,
				       struct ocfs2_lock_res_ops *ops,
				       void *priv)
{
	res->l_type          = type;
	res->l_ops           = ops;
	res->l_priv          = priv;

	res->l_level         = LKM_IVMODE;
	res->l_requested     = LKM_IVMODE;
	res->l_blocking      = LKM_IVMODE;
	res->l_action        = OCFS2_AST_INVALID;
	res->l_unlock_action = OCFS2_UNLOCK_INVALID;

	res->l_flags         = OCFS2_LOCK_INITIALIZED;

	ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug);
}

void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res)
{
	/* This also clears out the lock status block */
	memset(res, 0, sizeof(struct ocfs2_lock_res));
	spin_lock_init(&res->l_lock);
	init_waitqueue_head(&res->l_event);
	INIT_LIST_HEAD(&res->l_blocked_list);
	INIT_LIST_HEAD(&res->l_mask_waiters);
}

void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
			       enum ocfs2_lock_type type,
			       struct inode *inode)
{
	struct ocfs2_lock_res_ops *ops;

	switch(type) {
		case OCFS2_LOCK_TYPE_RW:
			ops = &ocfs2_inode_rw_lops;
			break;
		case OCFS2_LOCK_TYPE_META:
			ops = &ocfs2_inode_meta_lops;
			break;
		case OCFS2_LOCK_TYPE_DATA:
			ops = &ocfs2_inode_data_lops;
			break;
		default:
			mlog_bug_on_msg(1, "type: %d\n", type);
			ops = NULL; /* thanks, gcc */
			break;
	};

343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395
	ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno,
			      inode->i_generation, res->l_name);
	ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode);
}

static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres)
{
	__be64 inode_blkno_be;

	memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START],
	       sizeof(__be64));

	return be64_to_cpu(inode_blkno_be);
}

void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl,
				u64 parent, struct inode *inode)
{
	int len;
	u64 inode_blkno = OCFS2_I(inode)->ip_blkno;
	__be64 inode_blkno_be = cpu_to_be64(inode_blkno);
	struct ocfs2_lock_res *lockres = &dl->dl_lockres;

	ocfs2_lock_res_init_once(lockres);

	/*
	 * Unfortunately, the standard lock naming scheme won't work
	 * here because we have two 16 byte values to use. Instead,
	 * we'll stuff the inode number as a binary value. We still
	 * want error prints to show something without garbling the
	 * display, so drop a null byte in there before the inode
	 * number. A future version of OCFS2 will likely use all
	 * binary lock names. The stringified names have been a
	 * tremendous aid in debugging, but now that the debugfs
	 * interface exists, we can mangle things there if need be.
	 *
	 * NOTE: We also drop the standard "pad" value (the total lock
	 * name size stays the same though - the last part is all
	 * zeros due to the memset in ocfs2_lock_res_init_once()
	 */
	len = snprintf(lockres->l_name, OCFS2_DENTRY_LOCK_INO_START,
		       "%c%016llx",
		       ocfs2_lock_type_char(OCFS2_LOCK_TYPE_DENTRY),
		       (long long)parent);

	BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1));

	memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be,
	       sizeof(__be64));

	ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
				   OCFS2_LOCK_TYPE_DENTRY, &ocfs2_dentry_lops,
				   dl);
396 397 398 399 400 401 402 403
}

static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res,
				      struct ocfs2_super *osb)
{
	/* Superblock lockres doesn't come from a slab so we call init
	 * once on it manually.  */
	ocfs2_lock_res_init_once(res);
404 405
	ocfs2_build_lock_name(OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO,
			      0, res->l_name);
406 407 408 409 410 411 412 413 414 415
	ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER,
				   &ocfs2_super_lops, osb);
}

static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
				       struct ocfs2_super *osb)
{
	/* Rename lockres doesn't come from a slab so we call init
	 * once on it manually.  */
	ocfs2_lock_res_init_once(res);
416 417
	ocfs2_build_lock_name(OCFS2_LOCK_TYPE_RENAME, 0, 0, res->l_name);
	ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME,
418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608
				   &ocfs2_rename_lops, osb);
}

void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
{
	mlog_entry_void();

	if (!(res->l_flags & OCFS2_LOCK_INITIALIZED))
		return;

	ocfs2_remove_lockres_tracking(res);

	mlog_bug_on_msg(!list_empty(&res->l_blocked_list),
			"Lockres %s is on the blocked list\n",
			res->l_name);
	mlog_bug_on_msg(!list_empty(&res->l_mask_waiters),
			"Lockres %s has mask waiters pending\n",
			res->l_name);
	mlog_bug_on_msg(spin_is_locked(&res->l_lock),
			"Lockres %s is locked\n",
			res->l_name);
	mlog_bug_on_msg(res->l_ro_holders,
			"Lockres %s has %u ro holders\n",
			res->l_name, res->l_ro_holders);
	mlog_bug_on_msg(res->l_ex_holders,
			"Lockres %s has %u ex holders\n",
			res->l_name, res->l_ex_holders);

	/* Need to clear out the lock status block for the dlm */
	memset(&res->l_lksb, 0, sizeof(res->l_lksb));

	res->l_flags = 0UL;
	mlog_exit_void();
}

static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres,
				     int level)
{
	mlog_entry_void();

	BUG_ON(!lockres);

	switch(level) {
	case LKM_EXMODE:
		lockres->l_ex_holders++;
		break;
	case LKM_PRMODE:
		lockres->l_ro_holders++;
		break;
	default:
		BUG();
	}

	mlog_exit_void();
}

static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres,
				     int level)
{
	mlog_entry_void();

	BUG_ON(!lockres);

	switch(level) {
	case LKM_EXMODE:
		BUG_ON(!lockres->l_ex_holders);
		lockres->l_ex_holders--;
		break;
	case LKM_PRMODE:
		BUG_ON(!lockres->l_ro_holders);
		lockres->l_ro_holders--;
		break;
	default:
		BUG();
	}
	mlog_exit_void();
}

/* WARNING: This function lives in a world where the only three lock
 * levels are EX, PR, and NL. It *will* have to be adjusted when more
 * lock types are added. */
static inline int ocfs2_highest_compat_lock_level(int level)
{
	int new_level = LKM_EXMODE;

	if (level == LKM_EXMODE)
		new_level = LKM_NLMODE;
	else if (level == LKM_PRMODE)
		new_level = LKM_PRMODE;
	return new_level;
}

static void lockres_set_flags(struct ocfs2_lock_res *lockres,
			      unsigned long newflags)
{
	struct list_head *pos, *tmp;
	struct ocfs2_mask_waiter *mw;

 	assert_spin_locked(&lockres->l_lock);

	lockres->l_flags = newflags;

	list_for_each_safe(pos, tmp, &lockres->l_mask_waiters) {
		mw = list_entry(pos, struct ocfs2_mask_waiter, mw_item);
		if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
			continue;

		list_del_init(&mw->mw_item);
		mw->mw_status = 0;
		complete(&mw->mw_complete);
	}
}
static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or)
{
	lockres_set_flags(lockres, lockres->l_flags | or);
}
static void lockres_clear_flags(struct ocfs2_lock_res *lockres,
				unsigned long clear)
{
	lockres_set_flags(lockres, lockres->l_flags & ~clear);
}

static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres)
{
	mlog_entry_void();

	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
	BUG_ON(lockres->l_blocking <= LKM_NLMODE);

	lockres->l_level = lockres->l_requested;
	if (lockres->l_level <=
	    ocfs2_highest_compat_lock_level(lockres->l_blocking)) {
		lockres->l_blocking = LKM_NLMODE;
		lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
	}
	lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);

	mlog_exit_void();
}

static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres)
{
	mlog_entry_void();

	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));

	/* Convert from RO to EX doesn't really need anything as our
	 * information is already up to data. Convert from NL to
	 * *anything* however should mark ourselves as needing an
	 * update */
	if (lockres->l_level == LKM_NLMODE)
		lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);

	lockres->l_level = lockres->l_requested;
	lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);

	mlog_exit_void();
}

static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres)
{
	mlog_entry_void();

	BUG_ON((!lockres->l_flags & OCFS2_LOCK_BUSY));
	BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);

	if (lockres->l_requested > LKM_NLMODE &&
	    !(lockres->l_flags & OCFS2_LOCK_LOCAL))
		lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);

	lockres->l_level = lockres->l_requested;
	lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED);
	lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);

	mlog_exit_void();
}

static void ocfs2_inode_ast_func(void *opaque)
{
	struct ocfs2_lock_res *lockres = opaque;
	struct inode *inode;
	struct dlm_lockstatus *lksb;
	unsigned long flags;

	mlog_entry_void();

	inode = ocfs2_lock_res_inode(lockres);

609 610
	mlog(0, "AST fired for inode %llu, l_action = %u, type = %s\n",
	     (unsigned long long)OCFS2_I(inode)->ip_blkno, lockres->l_action,
611 612 613 614 615 616 617 618 619
	     ocfs2_lock_type_string(lockres->l_type));

	BUG_ON(!ocfs2_is_inode_lock(lockres));

	spin_lock_irqsave(&lockres->l_lock, flags);

	lksb = &(lockres->l_lksb);
	if (lksb->status != DLM_NORMAL) {
		mlog(ML_ERROR, "ocfs2_inode_ast_func: lksb status value of %u "
620 621
		     "on inode %llu\n", lksb->status,
		     (unsigned long long)OCFS2_I(inode)->ip_blkno);
622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702
		spin_unlock_irqrestore(&lockres->l_lock, flags);
		mlog_exit_void();
		return;
	}

	switch(lockres->l_action) {
	case OCFS2_AST_ATTACH:
		ocfs2_generic_handle_attach_action(lockres);
		lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL);
		break;
	case OCFS2_AST_CONVERT:
		ocfs2_generic_handle_convert_action(lockres);
		break;
	case OCFS2_AST_DOWNCONVERT:
		ocfs2_generic_handle_downconvert_action(lockres);
		break;
	default:
		mlog(ML_ERROR, "lockres %s: ast fired with invalid action: %u "
		     "lockres flags = 0x%lx, unlock action: %u\n",
		     lockres->l_name, lockres->l_action, lockres->l_flags,
		     lockres->l_unlock_action);

		BUG();
	}

	/* data and rw locking ignores refresh flag for now. */
	if (lockres->l_type != OCFS2_LOCK_TYPE_META)
		lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);

	/* set it to something invalid so if we get called again we
	 * can catch it. */
	lockres->l_action = OCFS2_AST_INVALID;
	spin_unlock_irqrestore(&lockres->l_lock, flags);
	wake_up(&lockres->l_event);

	mlog_exit_void();
}

static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
				     int level)
{
	int needs_downconvert = 0;
	mlog_entry_void();

	assert_spin_locked(&lockres->l_lock);

	lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);

	if (level > lockres->l_blocking) {
		/* only schedule a downconvert if we haven't already scheduled
		 * one that goes low enough to satisfy the level we're
		 * blocking.  this also catches the case where we get
		 * duplicate BASTs */
		if (ocfs2_highest_compat_lock_level(level) <
		    ocfs2_highest_compat_lock_level(lockres->l_blocking))
			needs_downconvert = 1;

		lockres->l_blocking = level;
	}

	mlog_exit(needs_downconvert);
	return needs_downconvert;
}

static void ocfs2_generic_bast_func(struct ocfs2_super *osb,
				    struct ocfs2_lock_res *lockres,
				    int level)
{
	int needs_downconvert;
	unsigned long flags;

	mlog_entry_void();

	BUG_ON(level <= LKM_NLMODE);

	spin_lock_irqsave(&lockres->l_lock, flags);
	needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
	if (needs_downconvert)
		ocfs2_schedule_blocked_lock(osb, lockres);
	spin_unlock_irqrestore(&lockres->l_lock, flags);

703 704
	wake_up(&lockres->l_event);

705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722
	ocfs2_kick_vote_thread(osb);

	mlog_exit_void();
}

static void ocfs2_inode_bast_func(void *opaque, int level)
{
	struct ocfs2_lock_res *lockres = opaque;
	struct inode *inode;
	struct ocfs2_super *osb;

	mlog_entry_void();

	BUG_ON(!ocfs2_is_inode_lock(lockres));

	inode = ocfs2_lock_res_inode(lockres);
	osb = OCFS2_SB(inode->i_sb);

723 724 725
	mlog(0, "BAST fired for inode %llu, blocking %d, level %d type %s\n",
	     (unsigned long long)OCFS2_I(inode)->ip_blkno, level,
	     lockres->l_level, ocfs2_lock_type_string(lockres->l_type));
726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768

	ocfs2_generic_bast_func(osb, lockres, level);

	mlog_exit_void();
}

static void ocfs2_generic_ast_func(struct ocfs2_lock_res *lockres,
				   int ignore_refresh)
{
	struct dlm_lockstatus *lksb = &lockres->l_lksb;
	unsigned long flags;

	spin_lock_irqsave(&lockres->l_lock, flags);

	if (lksb->status != DLM_NORMAL) {
		mlog(ML_ERROR, "lockres %s: lksb status value of %u!\n",
		     lockres->l_name, lksb->status);
		spin_unlock_irqrestore(&lockres->l_lock, flags);
		return;
	}

	switch(lockres->l_action) {
	case OCFS2_AST_ATTACH:
		ocfs2_generic_handle_attach_action(lockres);
		break;
	case OCFS2_AST_CONVERT:
		ocfs2_generic_handle_convert_action(lockres);
		break;
	case OCFS2_AST_DOWNCONVERT:
		ocfs2_generic_handle_downconvert_action(lockres);
		break;
	default:
		BUG();
	}

	if (ignore_refresh)
		lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);

	/* set it to something invalid so if we get called again we
	 * can catch it. */
	lockres->l_action = OCFS2_AST_INVALID;

	wake_up(&lockres->l_event);
769
	spin_unlock_irqrestore(&lockres->l_lock, flags);
770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833
}

static void ocfs2_super_ast_func(void *opaque)
{
	struct ocfs2_lock_res *lockres = opaque;

	mlog_entry_void();
	mlog(0, "Superblock AST fired\n");

	BUG_ON(!ocfs2_is_super_lock(lockres));
	ocfs2_generic_ast_func(lockres, 0);

	mlog_exit_void();
}

static void ocfs2_super_bast_func(void *opaque,
				  int level)
{
	struct ocfs2_lock_res *lockres = opaque;
	struct ocfs2_super *osb;

	mlog_entry_void();
	mlog(0, "Superblock BAST fired\n");

	BUG_ON(!ocfs2_is_super_lock(lockres));
       	osb = ocfs2_lock_res_super(lockres);
	ocfs2_generic_bast_func(osb, lockres, level);

	mlog_exit_void();
}

static void ocfs2_rename_ast_func(void *opaque)
{
	struct ocfs2_lock_res *lockres = opaque;

	mlog_entry_void();

	mlog(0, "Rename AST fired\n");

	BUG_ON(!ocfs2_is_rename_lock(lockres));

	ocfs2_generic_ast_func(lockres, 1);

	mlog_exit_void();
}

static void ocfs2_rename_bast_func(void *opaque,
				   int level)
{
	struct ocfs2_lock_res *lockres = opaque;
	struct ocfs2_super *osb;

	mlog_entry_void();

	mlog(0, "Rename BAST fired\n");

	BUG_ON(!ocfs2_is_rename_lock(lockres));

	osb = ocfs2_lock_res_super(lockres);
	ocfs2_generic_bast_func(osb, lockres, level);

	mlog_exit_void();
}

834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854
static void ocfs2_dentry_ast_func(void *opaque)
{
	struct ocfs2_lock_res *lockres = opaque;

	BUG_ON(!lockres);

	ocfs2_generic_ast_func(lockres, 1);
}

static void ocfs2_dentry_bast_func(void *opaque, int level)
{
	struct ocfs2_lock_res *lockres = opaque;
	struct ocfs2_dentry_lock *dl = lockres->l_priv;
	struct ocfs2_super *osb = OCFS2_SB(dl->dl_inode->i_sb);

	mlog(0, "Dentry bast: level: %d, name: %s\n", level,
	     lockres->l_name);

	ocfs2_generic_bast_func(osb, lockres, level);
}

855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907
static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
						int convert)
{
	unsigned long flags;

	mlog_entry_void();
	spin_lock_irqsave(&lockres->l_lock, flags);
	lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
	if (convert)
		lockres->l_action = OCFS2_AST_INVALID;
	else
		lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
	spin_unlock_irqrestore(&lockres->l_lock, flags);

	wake_up(&lockres->l_event);
	mlog_exit_void();
}

/* Note: If we detect another process working on the lock (i.e.,
 * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller
 * to do the right thing in that case.
 */
static int ocfs2_lock_create(struct ocfs2_super *osb,
			     struct ocfs2_lock_res *lockres,
			     int level,
			     int dlm_flags)
{
	int ret = 0;
	enum dlm_status status;
	unsigned long flags;

	mlog_entry_void();

	mlog(0, "lock %s, level = %d, flags = %d\n", lockres->l_name, level,
	     dlm_flags);

	spin_lock_irqsave(&lockres->l_lock, flags);
	if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) ||
	    (lockres->l_flags & OCFS2_LOCK_BUSY)) {
		spin_unlock_irqrestore(&lockres->l_lock, flags);
		goto bail;
	}

	lockres->l_action = OCFS2_AST_ATTACH;
	lockres->l_requested = level;
	lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
	spin_unlock_irqrestore(&lockres->l_lock, flags);

	status = dlmlock(osb->dlm,
			 level,
			 &lockres->l_lksb,
			 dlm_flags,
			 lockres->l_name,
908
			 OCFS2_LOCK_ID_MAX_LEN - 1,
909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097
			 lockres->l_ops->ast,
			 lockres,
			 lockres->l_ops->bast);
	if (status != DLM_NORMAL) {
		ocfs2_log_dlm_error("dlmlock", status, lockres);
		ret = -EINVAL;
		ocfs2_recover_from_dlm_error(lockres, 1);
	}

	mlog(0, "lock %s, successfull return from dlmlock\n", lockres->l_name);

bail:
	mlog_exit(ret);
	return ret;
}

static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres,
					int flag)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&lockres->l_lock, flags);
	ret = lockres->l_flags & flag;
	spin_unlock_irqrestore(&lockres->l_lock, flags);

	return ret;
}

static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres)

{
	wait_event(lockres->l_event,
		   !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY));
}

static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres)

{
	wait_event(lockres->l_event,
		   !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING));
}

/* predict what lock level we'll be dropping down to on behalf
 * of another node, and return true if the currently wanted
 * level will be compatible with it. */
static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
						     int wanted)
{
	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));

	return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking);
}

static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw)
{
	INIT_LIST_HEAD(&mw->mw_item);
	init_completion(&mw->mw_complete);
}

static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw)
{
	wait_for_completion(&mw->mw_complete);
	/* Re-arm the completion in case we want to wait on it again */
	INIT_COMPLETION(mw->mw_complete);
	return mw->mw_status;
}

static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres,
				    struct ocfs2_mask_waiter *mw,
				    unsigned long mask,
				    unsigned long goal)
{
	BUG_ON(!list_empty(&mw->mw_item));

	assert_spin_locked(&lockres->l_lock);

	list_add_tail(&mw->mw_item, &lockres->l_mask_waiters);
	mw->mw_mask = mask;
	mw->mw_goal = goal;
}

/* returns 0 if the mw that was removed was already satisfied, -EBUSY
 * if the mask still hadn't reached its goal */
static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
				      struct ocfs2_mask_waiter *mw)
{
	unsigned long flags;
	int ret = 0;

	spin_lock_irqsave(&lockres->l_lock, flags);
	if (!list_empty(&mw->mw_item)) {
		if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
			ret = -EBUSY;

		list_del_init(&mw->mw_item);
		init_completion(&mw->mw_complete);
	}
	spin_unlock_irqrestore(&lockres->l_lock, flags);

	return ret;

}

static int ocfs2_cluster_lock(struct ocfs2_super *osb,
			      struct ocfs2_lock_res *lockres,
			      int level,
			      int lkm_flags,
			      int arg_flags)
{
	struct ocfs2_mask_waiter mw;
	enum dlm_status status;
	int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR);
	int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */
	unsigned long flags;

	mlog_entry_void();

	ocfs2_init_mask_waiter(&mw);

again:
	wait = 0;

	if (catch_signals && signal_pending(current)) {
		ret = -ERESTARTSYS;
		goto out;
	}

	spin_lock_irqsave(&lockres->l_lock, flags);

	mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING,
			"Cluster lock called on freeing lockres %s! flags "
			"0x%lx\n", lockres->l_name, lockres->l_flags);

	/* We only compare against the currently granted level
	 * here. If the lock is blocked waiting on a downconvert,
	 * we'll get caught below. */
	if (lockres->l_flags & OCFS2_LOCK_BUSY &&
	    level > lockres->l_level) {
		/* is someone sitting in dlm_lock? If so, wait on
		 * them. */
		lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
		wait = 1;
		goto unlock;
	}

	if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
		/* lock has not been created yet. */
		spin_unlock_irqrestore(&lockres->l_lock, flags);

		ret = ocfs2_lock_create(osb, lockres, LKM_NLMODE, 0);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
		goto again;
	}

	if (lockres->l_flags & OCFS2_LOCK_BLOCKED &&
	    !ocfs2_may_continue_on_blocked_lock(lockres, level)) {
		/* is the lock is currently blocked on behalf of
		 * another node */
		lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0);
		wait = 1;
		goto unlock;
	}

	if (level > lockres->l_level) {
		if (lockres->l_action != OCFS2_AST_INVALID)
			mlog(ML_ERROR, "lockres %s has action %u pending\n",
			     lockres->l_name, lockres->l_action);

		lockres->l_action = OCFS2_AST_CONVERT;
		lockres->l_requested = level;
		lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
		spin_unlock_irqrestore(&lockres->l_lock, flags);

		BUG_ON(level == LKM_IVMODE);
		BUG_ON(level == LKM_NLMODE);

		mlog(0, "lock %s, convert from %d to level = %d\n",
		     lockres->l_name, lockres->l_level, level);

		/* call dlm_lock to upgrade lock now */
		status = dlmlock(osb->dlm,
				 level,
				 &lockres->l_lksb,
				 lkm_flags|LKM_CONVERT|LKM_VALBLK,
				 lockres->l_name,
1098
				 OCFS2_LOCK_ID_MAX_LEN - 1,
1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173
				 lockres->l_ops->ast,
				 lockres,
				 lockres->l_ops->bast);
		if (status != DLM_NORMAL) {
			if ((lkm_flags & LKM_NOQUEUE) &&
			    (status == DLM_NOTQUEUED))
				ret = -EAGAIN;
			else {
				ocfs2_log_dlm_error("dlmlock", status,
						    lockres);
				ret = -EINVAL;
			}
			ocfs2_recover_from_dlm_error(lockres, 1);
			goto out;
		}

		mlog(0, "lock %s, successfull return from dlmlock\n",
		     lockres->l_name);

		/* At this point we've gone inside the dlm and need to
		 * complete our work regardless. */
		catch_signals = 0;

		/* wait for busy to clear and carry on */
		goto again;
	}

	/* Ok, if we get here then we're good to go. */
	ocfs2_inc_holders(lockres, level);

	ret = 0;
unlock:
	spin_unlock_irqrestore(&lockres->l_lock, flags);
out:
	/*
	 * This is helping work around a lock inversion between the page lock
	 * and dlm locks.  One path holds the page lock while calling aops
	 * which block acquiring dlm locks.  The voting thread holds dlm
	 * locks while acquiring page locks while down converting data locks.
	 * This block is helping an aop path notice the inversion and back
	 * off to unlock its page lock before trying the dlm lock again.
	 */
	if (wait && arg_flags & OCFS2_LOCK_NONBLOCK &&
	    mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) {
		wait = 0;
		if (lockres_remove_mask_waiter(lockres, &mw))
			ret = -EAGAIN;
		else
			goto again;
	}
	if (wait) {
		ret = ocfs2_wait_for_mask(&mw);
		if (ret == 0)
			goto again;
		mlog_errno(ret);
	}

	mlog_exit(ret);
	return ret;
}

static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
				 struct ocfs2_lock_res *lockres,
				 int level)
{
	unsigned long flags;

	mlog_entry_void();
	spin_lock_irqsave(&lockres->l_lock, flags);
	ocfs2_dec_holders(lockres, level);
	ocfs2_vote_on_unlock(osb, lockres);
	spin_unlock_irqrestore(&lockres->l_lock, flags);
	mlog_exit_void();
}

1174 1175 1176
int ocfs2_create_new_lock(struct ocfs2_super *osb,
			  struct ocfs2_lock_res *lockres,
			  int ex)
1177
{
1178
	int level =  ex ? LKM_EXMODE : LKM_PRMODE;
1179 1180 1181 1182 1183 1184 1185
	unsigned long flags;

	spin_lock_irqsave(&lockres->l_lock, flags);
	BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
	lockres_or_flags(lockres, OCFS2_LOCK_LOCAL);
	spin_unlock_irqrestore(&lockres->l_lock, flags);

1186
	return ocfs2_lock_create(osb, lockres, level, LKM_LOCAL);
1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197
}

/* Grants us an EX lock on the data and metadata resources, skipping
 * the normal cluster directory lookup. Use this ONLY on newly created
 * inodes which other nodes can't possibly see, and which haven't been
 * hashed in the inode hash yet. This can give us a good performance
 * increase as it'll skip the network broadcast normally associated
 * with creating a new lock resource. */
int ocfs2_create_new_inode_locks(struct inode *inode)
{
	int ret;
1198
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1199 1200 1201 1202 1203 1204

	BUG_ON(!inode);
	BUG_ON(!ocfs2_inode_is_new(inode));

	mlog_entry_void();

1205
	mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno);
1206 1207 1208 1209 1210 1211 1212 1213 1214

	/* NOTE: That we don't increment any of the holder counts, nor
	 * do we add anything to a journal handle. Since this is
	 * supposed to be a new inode which the cluster doesn't know
	 * about yet, there is no need to.  As far as the LVB handling
	 * is concerned, this is basically like acquiring an EX lock
	 * on a resource which has an invalid one -- we'll set it
	 * valid when we release the EX. */

1215
	ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1);
1216 1217 1218 1219 1220
	if (ret) {
		mlog_errno(ret);
		goto bail;
	}

1221
	ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1);
1222 1223 1224 1225 1226
	if (ret) {
		mlog_errno(ret);
		goto bail;
	}

1227
	ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1);
1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246
	if (ret) {
		mlog_errno(ret);
		goto bail;
	}

bail:
	mlog_exit(ret);
	return ret;
}

int ocfs2_rw_lock(struct inode *inode, int write)
{
	int status, level;
	struct ocfs2_lock_res *lockres;

	BUG_ON(!inode);

	mlog_entry_void();

1247 1248
	mlog(0, "inode %llu take %s RW lock\n",
	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270
	     write ? "EXMODE" : "PRMODE");

	lockres = &OCFS2_I(inode)->ip_rw_lockres;

	level = write ? LKM_EXMODE : LKM_PRMODE;

	status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, 0,
				    0);
	if (status < 0)
		mlog_errno(status);

	mlog_exit(status);
	return status;
}

void ocfs2_rw_unlock(struct inode *inode, int write)
{
	int level = write ? LKM_EXMODE : LKM_PRMODE;
	struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres;

	mlog_entry_void();

1271 1272
	mlog(0, "inode %llu drop %s RW lock\n",
	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290
	     write ? "EXMODE" : "PRMODE");

	ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);

	mlog_exit_void();
}

int ocfs2_data_lock_full(struct inode *inode,
			 int write,
			 int arg_flags)
{
	int status = 0, level;
	struct ocfs2_lock_res *lockres;

	BUG_ON(!inode);

	mlog_entry_void();

1291 1292
	mlog(0, "inode %llu take %s DATA lock\n",
	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375
	     write ? "EXMODE" : "PRMODE");

	/* We'll allow faking a readonly data lock for
	 * rodevices. */
	if (ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb))) {
		if (write) {
			status = -EROFS;
			mlog_errno(status);
		}
		goto out;
	}

	lockres = &OCFS2_I(inode)->ip_data_lockres;

	level = write ? LKM_EXMODE : LKM_PRMODE;

	status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level,
				    0, arg_flags);
	if (status < 0 && status != -EAGAIN)
		mlog_errno(status);

out:
	mlog_exit(status);
	return status;
}

/* see ocfs2_meta_lock_with_page() */
int ocfs2_data_lock_with_page(struct inode *inode,
			      int write,
			      struct page *page)
{
	int ret;

	ret = ocfs2_data_lock_full(inode, write, OCFS2_LOCK_NONBLOCK);
	if (ret == -EAGAIN) {
		unlock_page(page);
		if (ocfs2_data_lock(inode, write) == 0)
			ocfs2_data_unlock(inode, write);
		ret = AOP_TRUNCATED_PAGE;
	}

	return ret;
}

static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
				 struct ocfs2_lock_res *lockres)
{
	int kick = 0;

	mlog_entry_void();

	/* If we know that another node is waiting on our lock, kick
	 * the vote thread * pre-emptively when we reach a release
	 * condition. */
	if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
		switch(lockres->l_blocking) {
		case LKM_EXMODE:
			if (!lockres->l_ex_holders && !lockres->l_ro_holders)
				kick = 1;
			break;
		case LKM_PRMODE:
			if (!lockres->l_ex_holders)
				kick = 1;
			break;
		default:
			BUG();
		}
	}

	if (kick)
		ocfs2_kick_vote_thread(osb);

	mlog_exit_void();
}

void ocfs2_data_unlock(struct inode *inode,
		       int write)
{
	int level = write ? LKM_EXMODE : LKM_PRMODE;
	struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_data_lockres;

	mlog_entry_void();

1376 1377
	mlog(0, "inode %llu drop %s DATA lock\n",
	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415
	     write ? "EXMODE" : "PRMODE");

	if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)))
		ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);

	mlog_exit_void();
}

#define OCFS2_SEC_BITS   34
#define OCFS2_SEC_SHIFT  (64 - 34)
#define OCFS2_NSEC_MASK  ((1ULL << OCFS2_SEC_SHIFT) - 1)

/* LVB only has room for 64 bits of time here so we pack it for
 * now. */
static u64 ocfs2_pack_timespec(struct timespec *spec)
{
	u64 res;
	u64 sec = spec->tv_sec;
	u32 nsec = spec->tv_nsec;

	res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK);

	return res;
}

/* Call this with the lockres locked. I am reasonably sure we don't
 * need ip_lock in this function as anyone who would be changing those
 * values is supposed to be blocked in ocfs2_meta_lock right now. */
static void __ocfs2_stuff_meta_lvb(struct inode *inode)
{
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
	struct ocfs2_meta_lvb *lvb;

	mlog_entry_void();

	lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;

1416
	lvb->lvb_version   = OCFS2_LVB_VERSION;
1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428
	lvb->lvb_isize	   = cpu_to_be64(i_size_read(inode));
	lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters);
	lvb->lvb_iuid      = cpu_to_be32(inode->i_uid);
	lvb->lvb_igid      = cpu_to_be32(inode->i_gid);
	lvb->lvb_imode     = cpu_to_be16(inode->i_mode);
	lvb->lvb_inlink    = cpu_to_be16(inode->i_nlink);
	lvb->lvb_iatime_packed  =
		cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime));
	lvb->lvb_ictime_packed =
		cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime));
	lvb->lvb_imtime_packed =
		cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime));
Herbert Poetzl's avatar
Herbert Poetzl committed
1429
	lvb->lvb_iattr    = cpu_to_be32(oi->ip_attr);
1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459

	mlog_meta_lvb(0, lockres);

	mlog_exit_void();
}

static void ocfs2_unpack_timespec(struct timespec *spec,
				  u64 packed_time)
{
	spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT;
	spec->tv_nsec = packed_time & OCFS2_NSEC_MASK;
}

static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
{
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
	struct ocfs2_meta_lvb *lvb;

	mlog_entry_void();

	mlog_meta_lvb(0, lockres);

	lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;

	/* We're safe here without the lockres lock... */
	spin_lock(&oi->ip_lock);
	oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters);
	i_size_write(inode, be64_to_cpu(lvb->lvb_isize));

Herbert Poetzl's avatar
Herbert Poetzl committed
1460 1461 1462
	oi->ip_attr = be32_to_cpu(lvb->lvb_iattr);
	ocfs2_set_inode_flags(inode);

1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488
	/* fast-symlinks are a special case */
	if (S_ISLNK(inode->i_mode) && !oi->ip_clusters)
		inode->i_blocks = 0;
	else
		inode->i_blocks =
			ocfs2_align_bytes_to_sectors(i_size_read(inode));

	inode->i_uid     = be32_to_cpu(lvb->lvb_iuid);
	inode->i_gid     = be32_to_cpu(lvb->lvb_igid);
	inode->i_mode    = be16_to_cpu(lvb->lvb_imode);
	inode->i_nlink   = be16_to_cpu(lvb->lvb_inlink);
	ocfs2_unpack_timespec(&inode->i_atime,
			      be64_to_cpu(lvb->lvb_iatime_packed));
	ocfs2_unpack_timespec(&inode->i_mtime,
			      be64_to_cpu(lvb->lvb_imtime_packed));
	ocfs2_unpack_timespec(&inode->i_ctime,
			      be64_to_cpu(lvb->lvb_ictime_packed));
	spin_unlock(&oi->ip_lock);

	mlog_exit_void();
}

static inline int ocfs2_meta_lvb_is_trustable(struct ocfs2_lock_res *lockres)
{
	struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;

1489
	if (lvb->lvb_version == OCFS2_LVB_VERSION)
1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563
		return 1;
	return 0;
}

/* Determine whether a lock resource needs to be refreshed, and
 * arbitrate who gets to refresh it.
 *
 *   0 means no refresh needed.
 *
 *   > 0 means you need to refresh this and you MUST call
 *   ocfs2_complete_lock_res_refresh afterwards. */
static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres)
{
	unsigned long flags;
	int status = 0;

	mlog_entry_void();

refresh_check:
	spin_lock_irqsave(&lockres->l_lock, flags);
	if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
		spin_unlock_irqrestore(&lockres->l_lock, flags);
		goto bail;
	}

	if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
		spin_unlock_irqrestore(&lockres->l_lock, flags);

		ocfs2_wait_on_refreshing_lock(lockres);
		goto refresh_check;
	}

	/* Ok, I'll be the one to refresh this lock. */
	lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING);
	spin_unlock_irqrestore(&lockres->l_lock, flags);

	status = 1;
bail:
	mlog_exit(status);
	return status;
}

/* If status is non zero, I'll mark it as not being in refresh
 * anymroe, but i won't clear the needs refresh flag. */
static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres,
						   int status)
{
	unsigned long flags;
	mlog_entry_void();

	spin_lock_irqsave(&lockres->l_lock, flags);
	lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING);
	if (!status)
		lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
	spin_unlock_irqrestore(&lockres->l_lock, flags);

	wake_up(&lockres->l_event);

	mlog_exit_void();
}

/* may or may not return a bh if it went to disk. */
static int ocfs2_meta_lock_update(struct inode *inode,
				  struct buffer_head **bh)
{
	int status = 0;
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_lock_res *lockres;
	struct ocfs2_dinode *fe;

	mlog_entry_void();

	spin_lock(&oi->ip_lock);
	if (oi->ip_flags & OCFS2_INODE_DELETED) {
1564
		mlog(0, "Orphaned inode %llu was deleted while we "
1565
		     "were waiting on a lock. ip_flags = 0x%x\n",
1566
		     (unsigned long long)oi->ip_blkno, oi->ip_flags);
1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586
		spin_unlock(&oi->ip_lock);
		status = -ENOENT;
		goto bail;
	}
	spin_unlock(&oi->ip_lock);

	lockres = &oi->ip_meta_lockres;

	if (!ocfs2_should_refresh_lock_res(lockres))
		goto bail;

	/* This will discard any caching information we might have had
	 * for the inode metadata. */
	ocfs2_metadata_cache_purge(inode);

	/* will do nothing for inode types that don't use the extent
	 * map (directories, bitmap files, etc) */
	ocfs2_extent_map_trunc(inode, 0);

	if (ocfs2_meta_lvb_is_trustable(lockres)) {
1587 1588
		mlog(0, "Trusting LVB on inode %llu\n",
		     (unsigned long long)oi->ip_blkno);
1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615
		ocfs2_refresh_inode_from_lvb(inode);
	} else {
		/* Boo, we have to go to disk. */
		/* read bh, cast, ocfs2_refresh_inode */
		status = ocfs2_read_block(OCFS2_SB(inode->i_sb), oi->ip_blkno,
					  bh, OCFS2_BH_CACHED, inode);
		if (status < 0) {
			mlog_errno(status);
			goto bail_refresh;
		}
		fe = (struct ocfs2_dinode *) (*bh)->b_data;

		/* This is a good chance to make sure we're not
		 * locking an invalid object.
		 *
		 * We bug on a stale inode here because we checked
		 * above whether it was wiped from disk. The wiping
		 * node provides a guarantee that we receive that
		 * message and can mark the inode before dropping any
		 * locks associated with it. */
		if (!OCFS2_IS_VALID_DINODE(fe)) {
			OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe);
			status = -EIO;
			goto bail_refresh;
		}
		mlog_bug_on_msg(inode->i_generation !=
				le32_to_cpu(fe->i_generation),
1616
				"Invalid dinode %llu disk generation: %u "
1617
				"inode->i_generation: %u\n",
1618 1619
				(unsigned long long)oi->ip_blkno,
				le32_to_cpu(fe->i_generation),
1620 1621 1622
				inode->i_generation);
		mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) ||
				!(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)),
1623 1624 1625
				"Stale dinode %llu dtime: %llu flags: 0x%x\n",
				(unsigned long long)oi->ip_blkno,
				(unsigned long long)le64_to_cpu(fe->i_dtime),
1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683
				le32_to_cpu(fe->i_flags));

		ocfs2_refresh_inode(inode, fe);
	}

	status = 0;
bail_refresh:
	ocfs2_complete_lock_res_refresh(lockres, status);
bail:
	mlog_exit(status);
	return status;
}

static int ocfs2_assign_bh(struct inode *inode,
			   struct buffer_head **ret_bh,
			   struct buffer_head *passed_bh)
{
	int status;

	if (passed_bh) {
		/* Ok, the update went to disk for us, use the
		 * returned bh. */
		*ret_bh = passed_bh;
		get_bh(*ret_bh);

		return 0;
	}

	status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
				  OCFS2_I(inode)->ip_blkno,
				  ret_bh,
				  OCFS2_BH_CACHED,
				  inode);
	if (status < 0)
		mlog_errno(status);

	return status;
}

/*
 * returns < 0 error if the callback will never be called, otherwise
 * the result of the lock will be communicated via the callback.
 */
int ocfs2_meta_lock_full(struct inode *inode,
			 struct ocfs2_journal_handle *handle,
			 struct buffer_head **ret_bh,
			 int ex,
			 int arg_flags)
{
	int status, level, dlm_flags, acquired;
	struct ocfs2_lock_res *lockres;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct buffer_head *local_bh = NULL;

	BUG_ON(!inode);

	mlog_entry_void();

1684 1685
	mlog(0, "inode %llu, take %s META lock\n",
	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818
	     ex ? "EXMODE" : "PRMODE");

	status = 0;
	acquired = 0;
	/* We'll allow faking a readonly metadata lock for
	 * rodevices. */
	if (ocfs2_is_hard_readonly(osb)) {
		if (ex)
			status = -EROFS;
		goto bail;
	}

	if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
		wait_event(osb->recovery_event,
			   ocfs2_node_map_is_empty(osb, &osb->recovery_map));

	acquired = 0;
	lockres = &OCFS2_I(inode)->ip_meta_lockres;
	level = ex ? LKM_EXMODE : LKM_PRMODE;
	dlm_flags = 0;
	if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
		dlm_flags |= LKM_NOQUEUE;

	status = ocfs2_cluster_lock(osb, lockres, level, dlm_flags, arg_flags);
	if (status < 0) {
		if (status != -EAGAIN && status != -EIOCBRETRY)
			mlog_errno(status);
		goto bail;
	}

	/* Notify the error cleanup path to drop the cluster lock. */
	acquired = 1;

	/* We wait twice because a node may have died while we were in
	 * the lower dlm layers. The second time though, we've
	 * committed to owning this lock so we don't allow signals to
	 * abort the operation. */
	if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
		wait_event(osb->recovery_event,
			   ocfs2_node_map_is_empty(osb, &osb->recovery_map));

	/* This is fun. The caller may want a bh back, or it may
	 * not. ocfs2_meta_lock_update definitely wants one in, but
	 * may or may not read one, depending on what's in the
	 * LVB. The result of all of this is that we've *only* gone to
	 * disk if we have to, so the complexity is worthwhile. */
	status = ocfs2_meta_lock_update(inode, &local_bh);
	if (status < 0) {
		if (status != -ENOENT)
			mlog_errno(status);
		goto bail;
	}

	if (ret_bh) {
		status = ocfs2_assign_bh(inode, ret_bh, local_bh);
		if (status < 0) {
			mlog_errno(status);
			goto bail;
		}
	}

	if (handle) {
		status = ocfs2_handle_add_lock(handle, inode);
		if (status < 0)
			mlog_errno(status);
	}

bail:
	if (status < 0) {
		if (ret_bh && (*ret_bh)) {
			brelse(*ret_bh);
			*ret_bh = NULL;
		}
		if (acquired)
			ocfs2_meta_unlock(inode, ex);
	}

	if (local_bh)
		brelse(local_bh);

	mlog_exit(status);
	return status;
}

/*
 * This is working around a lock inversion between tasks acquiring DLM locks
 * while holding a page lock and the vote thread which blocks dlm lock acquiry
 * while acquiring page locks.
 *
 * ** These _with_page variantes are only intended to be called from aop
 * methods that hold page locks and return a very specific *positive* error
 * code that aop methods pass up to the VFS -- test for errors with != 0. **
 *
 * The DLM is called such that it returns -EAGAIN if it would have blocked
 * waiting for the vote thread.  In that case we unlock our page so the vote
 * thread can make progress.  Once we've done this we have to return
 * AOP_TRUNCATED_PAGE so the aop method that called us can bubble that back up
 * into the VFS who will then immediately retry the aop call.
 *
 * We do a blocking lock and immediate unlock before returning, though, so that
 * the lock has a great chance of being cached on this node by the time the VFS
 * calls back to retry the aop.    This has a potential to livelock as nodes
 * ping locks back and forth, but that's a risk we're willing to take to avoid
 * the lock inversion simply.
 */
int ocfs2_meta_lock_with_page(struct inode *inode,
			      struct ocfs2_journal_handle *handle,
			      struct buffer_head **ret_bh,
			      int ex,
			      struct page *page)
{
	int ret;

	ret = ocfs2_meta_lock_full(inode, handle, ret_bh, ex,
				   OCFS2_LOCK_NONBLOCK);
	if (ret == -EAGAIN) {
		unlock_page(page);
		if (ocfs2_meta_lock(inode, handle, ret_bh, ex) == 0)
			ocfs2_meta_unlock(inode, ex);
		ret = AOP_TRUNCATED_PAGE;
	}

	return ret;
}

void ocfs2_meta_unlock(struct inode *inode,
		       int ex)
{
	int level = ex ? LKM_EXMODE : LKM_PRMODE;
	struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_meta_lockres;

	mlog_entry_void();

1819 1820
	mlog(0, "inode %llu drop %s META lock\n",
	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905
	     ex ? "EXMODE" : "PRMODE");

	if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)))
		ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);

	mlog_exit_void();
}

int ocfs2_super_lock(struct ocfs2_super *osb,
		     int ex)
{
	int status;
	int level = ex ? LKM_EXMODE : LKM_PRMODE;
	struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
	struct buffer_head *bh;
	struct ocfs2_slot_info *si = osb->slot_info;

	mlog_entry_void();

	if (ocfs2_is_hard_readonly(osb))
		return -EROFS;

	status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	/* The super block lock path is really in the best position to
	 * know when resources covered by the lock need to be
	 * refreshed, so we do it here. Of course, making sense of
	 * everything is up to the caller :) */
	status = ocfs2_should_refresh_lock_res(lockres);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}
	if (status) {
		bh = si->si_bh;
		status = ocfs2_read_block(osb, bh->b_blocknr, &bh, 0,
					  si->si_inode);
		if (status == 0)
			ocfs2_update_slot_info(si);

		ocfs2_complete_lock_res_refresh(lockres, status);

		if (status < 0)
			mlog_errno(status);
	}
bail:
	mlog_exit(status);
	return status;
}

void ocfs2_super_unlock(struct ocfs2_super *osb,
			int ex)
{
	int level = ex ? LKM_EXMODE : LKM_PRMODE;
	struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;

	ocfs2_cluster_unlock(osb, lockres, level);
}

int ocfs2_rename_lock(struct ocfs2_super *osb)
{
	int status;
	struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;

	if (ocfs2_is_hard_readonly(osb))
		return -EROFS;

	status = ocfs2_cluster_lock(osb, lockres, LKM_EXMODE, 0, 0);
	if (status < 0)
		mlog_errno(status);

	return status;
}

void ocfs2_rename_unlock(struct ocfs2_super *osb)
{
	struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;

	ocfs2_cluster_unlock(osb, lockres, LKM_EXMODE);
}

1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933
int ocfs2_dentry_lock(struct dentry *dentry, int ex)
{
	int ret;
	int level = ex ? LKM_EXMODE : LKM_PRMODE;
	struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
	struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);

	BUG_ON(!dl);

	if (ocfs2_is_hard_readonly(osb))
		return -EROFS;

	ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0);
	if (ret < 0)
		mlog_errno(ret);

	return ret;
}

void ocfs2_dentry_unlock(struct dentry *dentry, int ex)
{
	int level = ex ? LKM_EXMODE : LKM_PRMODE;
	struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
	struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);

	ocfs2_cluster_unlock(osb, &dl->dl_lockres, level);
}

1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063
/* Reference counting of the dlm debug structure. We want this because
 * open references on the debug inodes can live on after a mount, so
 * we can't rely on the ocfs2_super to always exist. */
static void ocfs2_dlm_debug_free(struct kref *kref)
{
	struct ocfs2_dlm_debug *dlm_debug;

	dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt);

	kfree(dlm_debug);
}

void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug)
{
	if (dlm_debug)
		kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free);
}

static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug)
{
	kref_get(&debug->d_refcnt);
}

struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
{
	struct ocfs2_dlm_debug *dlm_debug;

	dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL);
	if (!dlm_debug) {
		mlog_errno(-ENOMEM);
		goto out;
	}

	kref_init(&dlm_debug->d_refcnt);
	INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
	dlm_debug->d_locking_state = NULL;
out:
	return dlm_debug;
}

/* Access to this is arbitrated for us via seq_file->sem. */
struct ocfs2_dlm_seq_priv {
	struct ocfs2_dlm_debug *p_dlm_debug;
	struct ocfs2_lock_res p_iter_res;
	struct ocfs2_lock_res p_tmp_res;
};

static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start,
						 struct ocfs2_dlm_seq_priv *priv)
{
	struct ocfs2_lock_res *iter, *ret = NULL;
	struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug;

	assert_spin_locked(&ocfs2_dlm_tracking_lock);

	list_for_each_entry(iter, &start->l_debug_list, l_debug_list) {
		/* discover the head of the list */
		if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) {
			mlog(0, "End of list found, %p\n", ret);
			break;
		}

		/* We track our "dummy" iteration lockres' by a NULL
		 * l_ops field. */
		if (iter->l_ops != NULL) {
			ret = iter;
			break;
		}
	}

	return ret;
}

static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos)
{
	struct ocfs2_dlm_seq_priv *priv = m->private;
	struct ocfs2_lock_res *iter;

	spin_lock(&ocfs2_dlm_tracking_lock);
	iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv);
	if (iter) {
		/* Since lockres' have the lifetime of their container
		 * (which can be inodes, ocfs2_supers, etc) we want to
		 * copy this out to a temporary lockres while still
		 * under the spinlock. Obviously after this we can't
		 * trust any pointers on the copy returned, but that's
		 * ok as the information we want isn't typically held
		 * in them. */
		priv->p_tmp_res = *iter;
		iter = &priv->p_tmp_res;
	}
	spin_unlock(&ocfs2_dlm_tracking_lock);

	return iter;
}

static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v)
{
}

static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct ocfs2_dlm_seq_priv *priv = m->private;
	struct ocfs2_lock_res *iter = v;
	struct ocfs2_lock_res *dummy = &priv->p_iter_res;

	spin_lock(&ocfs2_dlm_tracking_lock);
	iter = ocfs2_dlm_next_res(iter, priv);
	list_del_init(&dummy->l_debug_list);
	if (iter) {
		list_add(&dummy->l_debug_list, &iter->l_debug_list);
		priv->p_tmp_res = *iter;
		iter = &priv->p_tmp_res;
	}
	spin_unlock(&ocfs2_dlm_tracking_lock);

	return iter;
}

/* So that debugfs.ocfs2 can determine which format is being used */
#define OCFS2_DLM_DEBUG_STR_VERSION 1
static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
{
	int i;
	char *lvb;
	struct ocfs2_lock_res *lockres = v;

	if (!lockres)
		return -EINVAL;

2064 2065 2066 2067 2068 2069 2070 2071 2072 2073
	seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION);

	if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY)
		seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1,
			   lockres->l_name,
			   (unsigned int)ocfs2_get_dentry_lock_ino(lockres));
	else
		seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name);

	seq_printf(m, "%d\t"
2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152
		   "0x%lx\t"
		   "0x%x\t"
		   "0x%x\t"
		   "%u\t"
		   "%u\t"
		   "%d\t"
		   "%d\t",
		   lockres->l_level,
		   lockres->l_flags,
		   lockres->l_action,
		   lockres->l_unlock_action,
		   lockres->l_ro_holders,
		   lockres->l_ex_holders,
		   lockres->l_requested,
		   lockres->l_blocking);

	/* Dump the raw LVB */
	lvb = lockres->l_lksb.lvb;
	for(i = 0; i < DLM_LVB_LEN; i++)
		seq_printf(m, "0x%x\t", lvb[i]);

	/* End the line */
	seq_printf(m, "\n");
	return 0;
}

static struct seq_operations ocfs2_dlm_seq_ops = {
	.start =	ocfs2_dlm_seq_start,
	.stop =		ocfs2_dlm_seq_stop,
	.next =		ocfs2_dlm_seq_next,
	.show =		ocfs2_dlm_seq_show,
};

static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file)
{
	struct seq_file *seq = (struct seq_file *) file->private_data;
	struct ocfs2_dlm_seq_priv *priv = seq->private;
	struct ocfs2_lock_res *res = &priv->p_iter_res;

	ocfs2_remove_lockres_tracking(res);
	ocfs2_put_dlm_debug(priv->p_dlm_debug);
	return seq_release_private(inode, file);
}

static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file)
{
	int ret;
	struct ocfs2_dlm_seq_priv *priv;
	struct seq_file *seq;
	struct ocfs2_super *osb;

	priv = kzalloc(sizeof(struct ocfs2_dlm_seq_priv), GFP_KERNEL);
	if (!priv) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}
	osb = (struct ocfs2_super *) inode->u.generic_ip;
	ocfs2_get_dlm_debug(osb->osb_dlm_debug);
	priv->p_dlm_debug = osb->osb_dlm_debug;
	INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list);

	ret = seq_open(file, &ocfs2_dlm_seq_ops);
	if (ret) {
		kfree(priv);
		mlog_errno(ret);
		goto out;
	}

	seq = (struct seq_file *) file->private_data;
	seq->private = priv;

	ocfs2_add_lockres_tracking(&priv->p_iter_res,
				   priv->p_dlm_debug);

out:
	return ret;
}

2153
static const struct file_operations ocfs2_dlm_debug_fops = {
2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206
	.open =		ocfs2_dlm_debug_open,
	.release =	ocfs2_dlm_debug_release,
	.read =		seq_read,
	.llseek =	seq_lseek,
};

static int ocfs2_dlm_init_debug(struct ocfs2_super *osb)
{
	int ret = 0;
	struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;

	dlm_debug->d_locking_state = debugfs_create_file("locking_state",
							 S_IFREG|S_IRUSR,
							 osb->osb_debug_root,
							 osb,
							 &ocfs2_dlm_debug_fops);
	if (!dlm_debug->d_locking_state) {
		ret = -EINVAL;
		mlog(ML_ERROR,
		     "Unable to create locking state debugfs file.\n");
		goto out;
	}

	ocfs2_get_dlm_debug(dlm_debug);
out:
	return ret;
}

static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
{
	struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;

	if (dlm_debug) {
		debugfs_remove(dlm_debug->d_locking_state);
		ocfs2_put_dlm_debug(dlm_debug);
	}
}

int ocfs2_dlm_init(struct ocfs2_super *osb)
{
	int status;
	u32 dlm_key;
	struct dlm_ctxt *dlm;

	mlog_entry_void();

	status = ocfs2_dlm_init_debug(osb);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	/* launch vote thread */
2207
	osb->vote_task = kthread_run(ocfs2_vote_thread, osb, "ocfs2vote");
2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440
	if (IS_ERR(osb->vote_task)) {
		status = PTR_ERR(osb->vote_task);
		osb->vote_task = NULL;
		mlog_errno(status);
		goto bail;
	}

	/* used by the dlm code to make message headers unique, each
	 * node in this domain must agree on this. */
	dlm_key = crc32_le(0, osb->uuid_str, strlen(osb->uuid_str));

	/* for now, uuid == domain */
	dlm = dlm_register_domain(osb->uuid_str, dlm_key);
	if (IS_ERR(dlm)) {
		status = PTR_ERR(dlm);
		mlog_errno(status);
		goto bail;
	}

	ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
	ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);

	dlm_register_eviction_cb(dlm, &osb->osb_eviction_cb);

	osb->dlm = dlm;

	status = 0;
bail:
	if (status < 0) {
		ocfs2_dlm_shutdown_debug(osb);
		if (osb->vote_task)
			kthread_stop(osb->vote_task);
	}

	mlog_exit(status);
	return status;
}

void ocfs2_dlm_shutdown(struct ocfs2_super *osb)
{
	mlog_entry_void();

	dlm_unregister_eviction_cb(&osb->osb_eviction_cb);

	ocfs2_drop_osb_locks(osb);

	if (osb->vote_task) {
		kthread_stop(osb->vote_task);
		osb->vote_task = NULL;
	}

	ocfs2_lock_res_free(&osb->osb_super_lockres);
	ocfs2_lock_res_free(&osb->osb_rename_lockres);

	dlm_unregister_domain(osb->dlm);
	osb->dlm = NULL;

	ocfs2_dlm_shutdown_debug(osb);

	mlog_exit_void();
}

static void ocfs2_unlock_ast_func(void *opaque, enum dlm_status status)
{
	struct ocfs2_lock_res *lockres = opaque;
	unsigned long flags;

	mlog_entry_void();

	mlog(0, "UNLOCK AST called on lock %s, action = %d\n", lockres->l_name,
	     lockres->l_unlock_action);

	spin_lock_irqsave(&lockres->l_lock, flags);
	/* We tried to cancel a convert request, but it was already
	 * granted. All we want to do here is clear our unlock
	 * state. The wake_up call done at the bottom is redundant
	 * (ocfs2_prepare_cancel_convert doesn't sleep on this) but doesn't
	 * hurt anything anyway */
	if (status == DLM_CANCELGRANT &&
	    lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
		mlog(0, "Got cancelgrant for %s\n", lockres->l_name);

		/* We don't clear the busy flag in this case as it
		 * should have been cleared by the ast which the dlm
		 * has called. */
		goto complete_unlock;
	}

	if (status != DLM_NORMAL) {
		mlog(ML_ERROR, "Dlm passes status %d for lock %s, "
		     "unlock_action %d\n", status, lockres->l_name,
		     lockres->l_unlock_action);
		spin_unlock_irqrestore(&lockres->l_lock, flags);
		return;
	}

	switch(lockres->l_unlock_action) {
	case OCFS2_UNLOCK_CANCEL_CONVERT:
		mlog(0, "Cancel convert success for %s\n", lockres->l_name);
		lockres->l_action = OCFS2_AST_INVALID;
		break;
	case OCFS2_UNLOCK_DROP_LOCK:
		lockres->l_level = LKM_IVMODE;
		break;
	default:
		BUG();
	}

	lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
complete_unlock:
	lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
	spin_unlock_irqrestore(&lockres->l_lock, flags);

	wake_up(&lockres->l_event);

	mlog_exit_void();
}

typedef void (ocfs2_pre_drop_cb_t)(struct ocfs2_lock_res *, void *);

struct drop_lock_cb {
	ocfs2_pre_drop_cb_t	*drop_func;
	void			*drop_data;
};

static int ocfs2_drop_lock(struct ocfs2_super *osb,
			   struct ocfs2_lock_res *lockres,
			   struct drop_lock_cb *dcb)
{
	enum dlm_status status;
	unsigned long flags;

	/* We didn't get anywhere near actually using this lockres. */
	if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
		goto out;

	spin_lock_irqsave(&lockres->l_lock, flags);

	mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING),
			"lockres %s, flags 0x%lx\n",
			lockres->l_name, lockres->l_flags);

	while (lockres->l_flags & OCFS2_LOCK_BUSY) {
		mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = "
		     "%u, unlock_action = %u\n",
		     lockres->l_name, lockres->l_flags, lockres->l_action,
		     lockres->l_unlock_action);

		spin_unlock_irqrestore(&lockres->l_lock, flags);

		/* XXX: Today we just wait on any busy
		 * locks... Perhaps we need to cancel converts in the
		 * future? */
		ocfs2_wait_on_busy_lock(lockres);

		spin_lock_irqsave(&lockres->l_lock, flags);
	}

	if (dcb)
		dcb->drop_func(lockres, dcb->drop_data);

	if (lockres->l_flags & OCFS2_LOCK_BUSY)
		mlog(ML_ERROR, "destroying busy lock: \"%s\"\n",
		     lockres->l_name);
	if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
		mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name);

	if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
		spin_unlock_irqrestore(&lockres->l_lock, flags);
		goto out;
	}

	lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED);

	/* make sure we never get here while waiting for an ast to
	 * fire. */
	BUG_ON(lockres->l_action != OCFS2_AST_INVALID);

	/* is this necessary? */
	lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
	lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK;
	spin_unlock_irqrestore(&lockres->l_lock, flags);

	mlog(0, "lock %s\n", lockres->l_name);

	status = dlmunlock(osb->dlm, &lockres->l_lksb, LKM_VALBLK,
			   lockres->l_ops->unlock_ast, lockres);
	if (status != DLM_NORMAL) {
		ocfs2_log_dlm_error("dlmunlock", status, lockres);
		mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
		dlm_print_one_lock(lockres->l_lksb.lockid);
		BUG();
	}
	mlog(0, "lock %s, successfull return from dlmunlock\n",
	     lockres->l_name);

	ocfs2_wait_on_busy_lock(lockres);
out:
	mlog_exit(0);
	return 0;
}

/* Mark the lockres as being dropped. It will no longer be
 * queued if blocking, but we still may have to wait on it
 * being dequeued from the vote thread before we can consider
 * it safe to drop. 
 *
 * You can *not* attempt to call cluster_lock on this lockres anymore. */
void ocfs2_mark_lockres_freeing(struct ocfs2_lock_res *lockres)
{
	int status;
	struct ocfs2_mask_waiter mw;
	unsigned long flags;

	ocfs2_init_mask_waiter(&mw);

	spin_lock_irqsave(&lockres->l_lock, flags);
	lockres->l_flags |= OCFS2_LOCK_FREEING;
	while (lockres->l_flags & OCFS2_LOCK_QUEUED) {
		lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0);
		spin_unlock_irqrestore(&lockres->l_lock, flags);

		mlog(0, "Waiting on lockres %s\n", lockres->l_name);

		status = ocfs2_wait_for_mask(&mw);
		if (status)
			mlog_errno(status);

		spin_lock_irqsave(&lockres->l_lock, flags);
	}
	spin_unlock_irqrestore(&lockres->l_lock, flags);
}

2441 2442
void ocfs2_simple_drop_lockres(struct ocfs2_super *osb,
			       struct ocfs2_lock_res *lockres)
2443
{
2444
	int ret;
2445

2446 2447 2448 2449 2450
	ocfs2_mark_lockres_freeing(lockres);
	ret = ocfs2_drop_lock(osb, lockres, NULL);
	if (ret)
		mlog_errno(ret);
}
2451

2452 2453 2454 2455
static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
{
	ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres);
	ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546
}

static void ocfs2_meta_pre_drop(struct ocfs2_lock_res *lockres, void *data)
{
	struct inode *inode = data;

	/* the metadata lock requires a bit more work as we have an
	 * LVB to worry about. */
	if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
	    lockres->l_level == LKM_EXMODE &&
	    !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
		__ocfs2_stuff_meta_lvb(inode);
}

int ocfs2_drop_inode_locks(struct inode *inode)
{
	int status, err;
	struct drop_lock_cb meta_dcb = { ocfs2_meta_pre_drop, inode, };

	mlog_entry_void();

	/* No need to call ocfs2_mark_lockres_freeing here -
	 * ocfs2_clear_inode has done it for us. */

	err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
			      &OCFS2_I(inode)->ip_data_lockres,
			      NULL);
	if (err < 0)
		mlog_errno(err);

	status = err;

	err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
			      &OCFS2_I(inode)->ip_meta_lockres,
			      &meta_dcb);
	if (err < 0)
		mlog_errno(err);
	if (err < 0 && !status)
		status = err;

	err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
			      &OCFS2_I(inode)->ip_rw_lockres,
			      NULL);
	if (err < 0)
		mlog_errno(err);
	if (err < 0 && !status)
		status = err;

	mlog_exit(status);
	return status;
}

static void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
				      int new_level)
{
	assert_spin_locked(&lockres->l_lock);

	BUG_ON(lockres->l_blocking <= LKM_NLMODE);

	if (lockres->l_level <= new_level) {
		mlog(ML_ERROR, "lockres->l_level (%u) <= new_level (%u)\n",
		     lockres->l_level, new_level);
		BUG();
	}

	mlog(0, "lock %s, new_level = %d, l_blocking = %d\n",
	     lockres->l_name, new_level, lockres->l_blocking);

	lockres->l_action = OCFS2_AST_DOWNCONVERT;
	lockres->l_requested = new_level;
	lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
}

static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
				  struct ocfs2_lock_res *lockres,
				  int new_level,
				  int lvb)
{
	int ret, dlm_flags = LKM_CONVERT;
	enum dlm_status status;

	mlog_entry_void();

	if (lvb)
		dlm_flags |= LKM_VALBLK;

	status = dlmlock(osb->dlm,
			 new_level,
			 &lockres->l_lksb,
			 dlm_flags,
			 lockres->l_name,
2547
			 OCFS2_LOCK_ID_MAX_LEN - 1,
2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724
			 lockres->l_ops->ast,
			 lockres,
			 lockres->l_ops->bast);
	if (status != DLM_NORMAL) {
		ocfs2_log_dlm_error("dlmlock", status, lockres);
		ret = -EINVAL;
		ocfs2_recover_from_dlm_error(lockres, 1);
		goto bail;
	}

	ret = 0;
bail:
	mlog_exit(ret);
	return ret;
}

/* returns 1 when the caller should unlock and call dlmunlock */
static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
				        struct ocfs2_lock_res *lockres)
{
	assert_spin_locked(&lockres->l_lock);

	mlog_entry_void();
	mlog(0, "lock %s\n", lockres->l_name);

	if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
		/* If we're already trying to cancel a lock conversion
		 * then just drop the spinlock and allow the caller to
		 * requeue this lock. */

		mlog(0, "Lockres %s, skip convert\n", lockres->l_name);
		return 0;
	}

	/* were we in a convert when we got the bast fire? */
	BUG_ON(lockres->l_action != OCFS2_AST_CONVERT &&
	       lockres->l_action != OCFS2_AST_DOWNCONVERT);
	/* set things up for the unlockast to know to just
	 * clear out the ast_action and unset busy, etc. */
	lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT;

	mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY),
			"lock %s, invalid flags: 0x%lx\n",
			lockres->l_name, lockres->l_flags);

	return 1;
}

static int ocfs2_cancel_convert(struct ocfs2_super *osb,
				struct ocfs2_lock_res *lockres)
{
	int ret;
	enum dlm_status status;

	mlog_entry_void();
	mlog(0, "lock %s\n", lockres->l_name);

	ret = 0;
	status = dlmunlock(osb->dlm,
			   &lockres->l_lksb,
			   LKM_CANCEL,
			   lockres->l_ops->unlock_ast,
			   lockres);
	if (status != DLM_NORMAL) {
		ocfs2_log_dlm_error("dlmunlock", status, lockres);
		ret = -EINVAL;
		ocfs2_recover_from_dlm_error(lockres, 0);
	}

	mlog(0, "lock %s return from dlmunlock\n", lockres->l_name);

	mlog_exit(ret);
	return ret;
}

static inline int ocfs2_can_downconvert_meta_lock(struct inode *inode,
						  struct ocfs2_lock_res *lockres,
						  int new_level)
{
	int ret;

	mlog_entry_void();

	BUG_ON(new_level != LKM_NLMODE && new_level != LKM_PRMODE);

	if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
		ret = 0;
		mlog(0, "lockres %s currently being refreshed -- backing "
		     "off!\n", lockres->l_name);
	} else if (new_level == LKM_PRMODE)
		ret = !lockres->l_ex_holders &&
			ocfs2_inode_fully_checkpointed(inode);
	else /* Must be NLMODE we're converting to. */
		ret = !lockres->l_ro_holders && !lockres->l_ex_holders &&
			ocfs2_inode_fully_checkpointed(inode);

	mlog_exit(ret);
	return ret;
}

static int ocfs2_do_unblock_meta(struct inode *inode,
				 int *requeue)
{
	int new_level;
	int set_lvb = 0;
	int ret = 0;
	struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_meta_lockres;
	unsigned long flags;

	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	mlog_entry_void();

	spin_lock_irqsave(&lockres->l_lock, flags);

	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));

	mlog(0, "l_level=%d, l_blocking=%d\n", lockres->l_level,
	     lockres->l_blocking);

	BUG_ON(lockres->l_level != LKM_EXMODE &&
	       lockres->l_level != LKM_PRMODE);

	if (lockres->l_flags & OCFS2_LOCK_BUSY) {
		*requeue = 1;
		ret = ocfs2_prepare_cancel_convert(osb, lockres);
		spin_unlock_irqrestore(&lockres->l_lock, flags);
		if (ret) {
			ret = ocfs2_cancel_convert(osb, lockres);
			if (ret < 0)
				mlog_errno(ret);
		}
		goto leave;
	}

	new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);

	mlog(0, "l_level=%d, l_blocking=%d, new_level=%d\n",
	     lockres->l_level, lockres->l_blocking, new_level);

	if (ocfs2_can_downconvert_meta_lock(inode, lockres, new_level)) {
		if (lockres->l_level == LKM_EXMODE)
			set_lvb = 1;

		/* If the lock hasn't been refreshed yet (rare), then
		 * our memory inode values are old and we skip
		 * stuffing the lvb. There's no need to actually clear
		 * out the lvb here as it's value is still valid. */
		if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
			if (set_lvb)
				__ocfs2_stuff_meta_lvb(inode);
		} else
			mlog(0, "lockres %s: downconverting stale lock!\n",
			     lockres->l_name);

		mlog(0, "calling ocfs2_downconvert_lock with l_level=%d, "
		     "l_blocking=%d, new_level=%d\n",
		     lockres->l_level, lockres->l_blocking, new_level);

		ocfs2_prepare_downconvert(lockres, new_level);
		spin_unlock_irqrestore(&lockres->l_lock, flags);
		ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb);
		goto leave;
	}
	if (!ocfs2_inode_fully_checkpointed(inode))
		ocfs2_start_checkpoint(osb);

	*requeue = 1;
	spin_unlock_irqrestore(&lockres->l_lock, flags);
	ret = 0;
leave:
	mlog_exit(ret);
	return ret;
}

static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb,
				      struct ocfs2_lock_res *lockres,
2725
				      struct ocfs2_unblock_ctl *ctl,
2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740
				      ocfs2_convert_worker_t *worker)
{
	unsigned long flags;
	int blocking;
	int new_level;
	int ret = 0;

	mlog_entry_void();

	spin_lock_irqsave(&lockres->l_lock, flags);

	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));

recheck:
	if (lockres->l_flags & OCFS2_LOCK_BUSY) {
2741
		ctl->requeue = 1;
2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756
		ret = ocfs2_prepare_cancel_convert(osb, lockres);
		spin_unlock_irqrestore(&lockres->l_lock, flags);
		if (ret) {
			ret = ocfs2_cancel_convert(osb, lockres);
			if (ret < 0)
				mlog_errno(ret);
		}
		goto leave;
	}

	/* if we're blocking an exclusive and we have *any* holders,
	 * then requeue. */
	if ((lockres->l_blocking == LKM_EXMODE)
	    && (lockres->l_ex_holders || lockres->l_ro_holders)) {
		spin_unlock_irqrestore(&lockres->l_lock, flags);
2757
		ctl->requeue = 1;
2758 2759 2760 2761 2762 2763 2764 2765 2766
		ret = 0;
		goto leave;
	}

	/* If it's a PR we're blocking, then only
	 * requeue if we've got any EX holders */
	if (lockres->l_blocking == LKM_PRMODE &&
	    lockres->l_ex_holders) {
		spin_unlock_irqrestore(&lockres->l_lock, flags);
2767
		ctl->requeue = 1;
2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784
		ret = 0;
		goto leave;
	}

	/* If we get here, then we know that there are no more
	 * incompatible holders (and anyone asking for an incompatible
	 * lock is blocked). We can now downconvert the lock */
	if (!worker)
		goto downconvert;

	/* Some lockres types want to do a bit of work before
	 * downconverting a lock. Allow that here. The worker function
	 * may sleep, so we save off a copy of what we're blocking as
	 * it may change while we're not holding the spin lock. */
	blocking = lockres->l_blocking;
	spin_unlock_irqrestore(&lockres->l_lock, flags);

2785 2786 2787 2788
	ctl->unblock_action = worker(lockres, blocking);

	if (ctl->unblock_action == UNBLOCK_STOP_POST)
		goto leave;
2789 2790 2791 2792 2793 2794 2795 2796 2797

	spin_lock_irqsave(&lockres->l_lock, flags);
	if (blocking != lockres->l_blocking) {
		/* If this changed underneath us, then we can't drop
		 * it just yet. */
		goto recheck;
	}

downconvert:
2798
	ctl->requeue = 0;
2799 2800 2801 2802 2803 2804 2805 2806 2807 2808
	new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);

	ocfs2_prepare_downconvert(lockres, new_level);
	spin_unlock_irqrestore(&lockres->l_lock, flags);
	ret = ocfs2_downconvert_lock(osb, lockres, new_level, 0);
leave:
	mlog_exit(ret);
	return ret;
}

2809 2810
static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
				     int blocking)
2811 2812 2813 2814 2815 2816 2817 2818
{
	struct inode *inode;
	struct address_space *mapping;

       	inode = ocfs2_lock_res_inode(lockres);
	mapping = inode->i_mapping;

	if (filemap_fdatawrite(mapping)) {
2819 2820
		mlog(ML_ERROR, "Could not sync inode %llu for downconvert!",
		     (unsigned long long)OCFS2_I(inode)->ip_blkno);
2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834
	}
	sync_mapping_buffers(mapping);
	if (blocking == LKM_EXMODE) {
		truncate_inode_pages(mapping, 0);
		unmap_mapping_range(mapping, 0, 0, 0);
	} else {
		/* We only need to wait on the I/O if we're not also
		 * truncating pages because truncate_inode_pages waits
		 * for us above. We don't truncate pages if we're
		 * blocking anything < EXMODE because we want to keep
		 * them around in that case. */
		filemap_fdatawait(mapping);
	}

2835
	return UNBLOCK_CONTINUE;
2836 2837 2838
}

int ocfs2_unblock_data(struct ocfs2_lock_res *lockres,
2839
		       struct ocfs2_unblock_ctl *ctl)
2840 2841 2842 2843 2844 2845 2846 2847 2848 2849
{
	int status;
	struct inode *inode;
	struct ocfs2_super *osb;

	mlog_entry_void();

	inode = ocfs2_lock_res_inode(lockres);
	osb = OCFS2_SB(inode->i_sb);

2850 2851
	mlog(0, "unblock inode %llu\n",
	     (unsigned long long)OCFS2_I(inode)->ip_blkno);
2852

2853
	status = ocfs2_generic_unblock_lock(osb, lockres, ctl,
2854 2855 2856 2857
					    ocfs2_data_convert_worker);
	if (status < 0)
		mlog_errno(status);

2858
	mlog(0, "inode %llu, requeue = %d\n",
2859
	     (unsigned long long)OCFS2_I(inode)->ip_blkno, ctl->requeue);
2860 2861 2862 2863 2864 2865

	mlog_exit(status);
	return status;
}

static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres,
2866
				    struct ocfs2_unblock_ctl *ctl)
2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877
{
	int status;
	struct inode *inode;

	mlog_entry_void();

	mlog(0, "Unblock lockres %s\n", lockres->l_name);

	inode  = ocfs2_lock_res_inode(lockres);

	status = ocfs2_generic_unblock_lock(OCFS2_SB(inode->i_sb),
2878
					    lockres, ctl, NULL);
2879 2880 2881 2882 2883 2884 2885
	if (status < 0)
		mlog_errno(status);

	mlog_exit(status);
	return status;
}

2886 2887
static int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres,
			      struct ocfs2_unblock_ctl *ctl)
2888 2889 2890 2891 2892 2893 2894 2895
{
	int status;
	struct inode *inode;

	mlog_entry_void();

       	inode = ocfs2_lock_res_inode(lockres);

2896 2897
	mlog(0, "unblock inode %llu\n",
	     (unsigned long long)OCFS2_I(inode)->ip_blkno);
2898

2899
	status = ocfs2_do_unblock_meta(inode, &ctl->requeue);
2900 2901 2902
	if (status < 0)
		mlog_errno(status);

2903
	mlog(0, "inode %llu, requeue = %d\n",
2904
	     (unsigned long long)OCFS2_I(inode)->ip_blkno, ctl->requeue);
2905 2906 2907 2908 2909

	mlog_exit(status);
	return status;
}

2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053
/*
 * Does the final reference drop on our dentry lock. Right now this
 * happens in the vote thread, but we could choose to simplify the
 * dlmglue API and push these off to the ocfs2_wq in the future.
 */
static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
				     struct ocfs2_lock_res *lockres)
{
	struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
	ocfs2_dentry_lock_put(osb, dl);
}

/*
 * d_delete() matching dentries before the lock downconvert.
 *
 * At this point, any process waiting to destroy the
 * dentry_lock due to last ref count is stopped by the
 * OCFS2_LOCK_QUEUED flag.
 *
 * We have two potential problems
 *
 * 1) If we do the last reference drop on our dentry_lock (via dput)
 *    we'll wind up in ocfs2_release_dentry_lock(), waiting on
 *    the downconvert to finish. Instead we take an elevated
 *    reference and push the drop until after we've completed our
 *    unblock processing.
 *
 * 2) There might be another process with a final reference,
 *    waiting on us to finish processing. If this is the case, we
 *    detect it and exit out - there's no more dentries anyway.
 */
static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
				       int blocking)
{
	struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
	struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode);
	struct dentry *dentry;
	unsigned long flags;
	int extra_ref = 0;

	/*
	 * This node is blocking another node from getting a read
	 * lock. This happens when we've renamed within a
	 * directory. We've forced the other nodes to d_delete(), but
	 * we never actually dropped our lock because it's still
	 * valid. The downconvert code will retain a PR for this node,
	 * so there's no further work to do.
	 */
	if (blocking == LKM_PRMODE)
		return UNBLOCK_CONTINUE;

	/*
	 * Mark this inode as potentially orphaned. The code in
	 * ocfs2_delete_inode() will figure out whether it actually
	 * needs to be freed or not.
	 */
	spin_lock(&oi->ip_lock);
	oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED;
	spin_unlock(&oi->ip_lock);

	/*
	 * Yuck. We need to make sure however that the check of
	 * OCFS2_LOCK_FREEING and the extra reference are atomic with
	 * respect to a reference decrement or the setting of that
	 * flag.
	 */
	spin_lock_irqsave(&lockres->l_lock, flags);
	spin_lock(&dentry_attach_lock);
	if (!(lockres->l_flags & OCFS2_LOCK_FREEING)
	    && dl->dl_count) {
		dl->dl_count++;
		extra_ref = 1;
	}
	spin_unlock(&dentry_attach_lock);
	spin_unlock_irqrestore(&lockres->l_lock, flags);

	mlog(0, "extra_ref = %d\n", extra_ref);

	/*
	 * We have a process waiting on us in ocfs2_dentry_iput(),
	 * which means we can't have any more outstanding
	 * aliases. There's no need to do any more work.
	 */
	if (!extra_ref)
		return UNBLOCK_CONTINUE;

	spin_lock(&dentry_attach_lock);
	while (1) {
		dentry = ocfs2_find_local_alias(dl->dl_inode,
						dl->dl_parent_blkno, 1);
		if (!dentry)
			break;
		spin_unlock(&dentry_attach_lock);

		mlog(0, "d_delete(%.*s);\n", dentry->d_name.len,
		     dentry->d_name.name);

		/*
		 * The following dcache calls may do an
		 * iput(). Normally we don't want that from the
		 * downconverting thread, but in this case it's ok
		 * because the requesting node already has an
		 * exclusive lock on the inode, so it can't be queued
		 * for a downconvert.
		 */
		d_delete(dentry);
		dput(dentry);

		spin_lock(&dentry_attach_lock);
	}
	spin_unlock(&dentry_attach_lock);

	/*
	 * If we are the last holder of this dentry lock, there is no
	 * reason to downconvert so skip straight to the unlock.
	 */
	if (dl->dl_count == 1)
		return UNBLOCK_STOP_POST;

	return UNBLOCK_CONTINUE_POST;
}

static int ocfs2_unblock_dentry_lock(struct ocfs2_lock_res *lockres,
				     struct ocfs2_unblock_ctl *ctl)
{
	int ret;
	struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
	struct ocfs2_super *osb = OCFS2_SB(dl->dl_inode->i_sb);

	mlog(0, "unblock dentry lock: %llu\n",
	     (unsigned long long)OCFS2_I(dl->dl_inode)->ip_blkno);

	ret = ocfs2_generic_unblock_lock(osb,
					 lockres,
					 ctl,
					 ocfs2_dentry_convert_worker);
	if (ret < 0)
		mlog_errno(ret);

	mlog(0, "requeue = %d, post = %d\n", ctl->requeue, ctl->unblock_action);

	return ret;
}

3054 3055 3056
/* Generic unblock function for any lockres whose private data is an
 * ocfs2_super pointer. */
static int ocfs2_unblock_osb_lock(struct ocfs2_lock_res *lockres,
3057
				  struct ocfs2_unblock_ctl *ctl)
3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069
{
	int status;
	struct ocfs2_super *osb;

	mlog_entry_void();

	mlog(0, "Unblock lockres %s\n", lockres->l_name);

	osb = ocfs2_lock_res_super(lockres);

	status = ocfs2_generic_unblock_lock(osb,
					    lockres,
3070
					    ctl,
3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082
					    NULL);
	if (status < 0)
		mlog_errno(status);

	mlog_exit(status);
	return status;
}

void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
				struct ocfs2_lock_res *lockres)
{
	int status;
3083
	struct ocfs2_unblock_ctl ctl = {0, 0,};
3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107
	unsigned long flags;

	/* Our reference to the lockres in this function can be
	 * considered valid until we remove the OCFS2_LOCK_QUEUED
	 * flag. */

	mlog_entry_void();

	BUG_ON(!lockres);
	BUG_ON(!lockres->l_ops);
	BUG_ON(!lockres->l_ops->unblock);

	mlog(0, "lockres %s blocked.\n", lockres->l_name);

	/* Detect whether a lock has been marked as going away while
	 * the vote thread was processing other things. A lock can
	 * still be marked with OCFS2_LOCK_FREEING after this check,
	 * but short circuiting here will still save us some
	 * performance. */
	spin_lock_irqsave(&lockres->l_lock, flags);
	if (lockres->l_flags & OCFS2_LOCK_FREEING)
		goto unqueue;
	spin_unlock_irqrestore(&lockres->l_lock, flags);

3108
	status = lockres->l_ops->unblock(lockres, &ctl);
3109 3110 3111 3112 3113
	if (status < 0)
		mlog_errno(status);

	spin_lock_irqsave(&lockres->l_lock, flags);
unqueue:
3114
	if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) {
3115 3116 3117 3118 3119
		lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED);
	} else
		ocfs2_schedule_blocked_lock(osb, lockres);

	mlog(0, "lockres %s, requeue = %s.\n", lockres->l_name,
3120
	     ctl.requeue ? "yes" : "no");
3121 3122
	spin_unlock_irqrestore(&lockres->l_lock, flags);

3123 3124 3125 3126
	if (ctl.unblock_action != UNBLOCK_CONTINUE
	    && lockres->l_ops->post_unlock)
		lockres->l_ops->post_unlock(osb, lockres);

3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169
	mlog_exit_void();
}

static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
					struct ocfs2_lock_res *lockres)
{
	mlog_entry_void();

	assert_spin_locked(&lockres->l_lock);

	if (lockres->l_flags & OCFS2_LOCK_FREEING) {
		/* Do not schedule a lock for downconvert when it's on
		 * the way to destruction - any nodes wanting access
		 * to the resource will get it soon. */
		mlog(0, "Lockres %s won't be scheduled: flags 0x%lx\n",
		     lockres->l_name, lockres->l_flags);
		return;
	}

	lockres_or_flags(lockres, OCFS2_LOCK_QUEUED);

	spin_lock(&osb->vote_task_lock);
	if (list_empty(&lockres->l_blocked_list)) {
		list_add_tail(&lockres->l_blocked_list,
			      &osb->blocked_lock_list);
		osb->blocked_lock_count++;
	}
	spin_unlock(&osb->vote_task_lock);

	mlog_exit_void();
}

/* This aids in debugging situations where a bad LVB might be involved. */
void ocfs2_dump_meta_lvb_info(u64 level,
			      const char *function,
			      unsigned int line,
			      struct ocfs2_lock_res *lockres)
{
	struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;

	mlog(level, "LVB information for %s (called from %s:%u):\n",
	     lockres->l_name, function, line);
	mlog(level, "version: %u, clusters: %u\n",
3170
	     lvb->lvb_version, be32_to_cpu(lvb->lvb_iclusters));
3171 3172 3173 3174 3175
	mlog(level, "size: %llu, uid %u, gid %u, mode 0x%x\n",
	     (unsigned long long)be64_to_cpu(lvb->lvb_isize),
	     be32_to_cpu(lvb->lvb_iuid), be32_to_cpu(lvb->lvb_igid),
	     be16_to_cpu(lvb->lvb_imode));
	mlog(level, "nlink %u, atime_packed 0x%llx, ctime_packed 0x%llx, "
Herbert Poetzl's avatar
Herbert Poetzl committed
3176
	     "mtime_packed 0x%llx iattr 0x%x\n", be16_to_cpu(lvb->lvb_inlink),
3177 3178
	     (long long)be64_to_cpu(lvb->lvb_iatime_packed),
	     (long long)be64_to_cpu(lvb->lvb_ictime_packed),
Herbert Poetzl's avatar
Herbert Poetzl committed
3179 3180
	     (long long)be64_to_cpu(lvb->lvb_imtime_packed),
	     be32_to_cpu(lvb->lvb_iattr));
3181
}