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v4.17
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2007 Oracle.  All rights reserved.
   4 */
   5
   6#include <linux/slab.h>
   7#include <linux/blkdev.h>
   8#include <linux/writeback.h>
   9#include <linux/pagevec.h>
 
  10#include "ctree.h"
  11#include "transaction.h"
  12#include "btrfs_inode.h"
  13#include "extent_io.h"
  14#include "disk-io.h"
  15#include "compression.h"
 
 
 
  16
  17static struct kmem_cache *btrfs_ordered_extent_cache;
  18
  19static u64 entry_end(struct btrfs_ordered_extent *entry)
  20{
  21	if (entry->file_offset + entry->len < entry->file_offset)
  22		return (u64)-1;
  23	return entry->file_offset + entry->len;
  24}
  25
  26/* returns NULL if the insertion worked, or it returns the node it did find
  27 * in the tree
  28 */
  29static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
  30				   struct rb_node *node)
  31{
  32	struct rb_node **p = &root->rb_node;
  33	struct rb_node *parent = NULL;
  34	struct btrfs_ordered_extent *entry;
  35
  36	while (*p) {
  37		parent = *p;
  38		entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
  39
  40		if (file_offset < entry->file_offset)
  41			p = &(*p)->rb_left;
  42		else if (file_offset >= entry_end(entry))
  43			p = &(*p)->rb_right;
  44		else
  45			return parent;
  46	}
  47
  48	rb_link_node(node, parent, p);
  49	rb_insert_color(node, root);
  50	return NULL;
  51}
  52
  53static void ordered_data_tree_panic(struct inode *inode, int errno,
  54					       u64 offset)
  55{
  56	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
  57	btrfs_panic(fs_info, errno,
  58		    "Inconsistency in ordered tree at offset %llu", offset);
  59}
  60
  61/*
  62 * look for a given offset in the tree, and if it can't be found return the
  63 * first lesser offset
  64 */
  65static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
  66				     struct rb_node **prev_ret)
  67{
  68	struct rb_node *n = root->rb_node;
  69	struct rb_node *prev = NULL;
  70	struct rb_node *test;
  71	struct btrfs_ordered_extent *entry;
  72	struct btrfs_ordered_extent *prev_entry = NULL;
  73
  74	while (n) {
  75		entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
  76		prev = n;
  77		prev_entry = entry;
  78
  79		if (file_offset < entry->file_offset)
  80			n = n->rb_left;
  81		else if (file_offset >= entry_end(entry))
  82			n = n->rb_right;
  83		else
  84			return n;
  85	}
  86	if (!prev_ret)
  87		return NULL;
  88
  89	while (prev && file_offset >= entry_end(prev_entry)) {
  90		test = rb_next(prev);
  91		if (!test)
  92			break;
  93		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
  94				      rb_node);
  95		if (file_offset < entry_end(prev_entry))
  96			break;
  97
  98		prev = test;
  99	}
 100	if (prev)
 101		prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
 102				      rb_node);
 103	while (prev && file_offset < entry_end(prev_entry)) {
 104		test = rb_prev(prev);
 105		if (!test)
 106			break;
 107		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 108				      rb_node);
 109		prev = test;
 110	}
 111	*prev_ret = prev;
 112	return NULL;
 113}
 114
 115/*
 116 * helper to check if a given offset is inside a given entry
 117 */
 118static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
 119{
 120	if (file_offset < entry->file_offset ||
 121	    entry->file_offset + entry->len <= file_offset)
 122		return 0;
 123	return 1;
 124}
 125
 126static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
 127			  u64 len)
 128{
 129	if (file_offset + len <= entry->file_offset ||
 130	    entry->file_offset + entry->len <= file_offset)
 131		return 0;
 132	return 1;
 133}
 134
 135/*
 136 * look find the first ordered struct that has this offset, otherwise
 137 * the first one less than this offset
 138 */
 139static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
 140					  u64 file_offset)
 141{
 142	struct rb_root *root = &tree->tree;
 143	struct rb_node *prev = NULL;
 144	struct rb_node *ret;
 145	struct btrfs_ordered_extent *entry;
 146
 147	if (tree->last) {
 148		entry = rb_entry(tree->last, struct btrfs_ordered_extent,
 149				 rb_node);
 150		if (offset_in_entry(entry, file_offset))
 151			return tree->last;
 152	}
 153	ret = __tree_search(root, file_offset, &prev);
 154	if (!ret)
 155		ret = prev;
 156	if (ret)
 157		tree->last = ret;
 158	return ret;
 159}
 160
 161/* allocate and add a new ordered_extent into the per-inode tree.
 162 * file_offset is the logical offset in the file
 163 *
 164 * start is the disk block number of an extent already reserved in the
 165 * extent allocation tree
 166 *
 167 * len is the length of the extent
 168 *
 169 * The tree is given a single reference on the ordered extent that was
 170 * inserted.
 171 */
 172static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 173				      u64 start, u64 len, u64 disk_len,
 174				      int type, int dio, int compress_type)
 
 175{
 176	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 177	struct btrfs_root *root = BTRFS_I(inode)->root;
 178	struct btrfs_ordered_inode_tree *tree;
 179	struct rb_node *node;
 180	struct btrfs_ordered_extent *entry;
 
 181
 182	tree = &BTRFS_I(inode)->ordered_tree;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 183	entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 184	if (!entry)
 185		return -ENOMEM;
 186
 187	entry->file_offset = file_offset;
 188	entry->start = start;
 189	entry->len = len;
 190	entry->disk_len = disk_len;
 191	entry->bytes_left = len;
 192	entry->inode = igrab(inode);
 193	entry->compress_type = compress_type;
 194	entry->truncated_len = (u64)-1;
 195	if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
 196		set_bit(type, &entry->flags);
 
 
 
 
 
 
 
 
 
 197
 198	if (dio)
 199		set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
 200
 201	/* one ref for the tree */
 202	refcount_set(&entry->refs, 1);
 203	init_waitqueue_head(&entry->wait);
 204	INIT_LIST_HEAD(&entry->list);
 
 205	INIT_LIST_HEAD(&entry->root_extent_list);
 206	INIT_LIST_HEAD(&entry->work_list);
 207	init_completion(&entry->completion);
 208	INIT_LIST_HEAD(&entry->log_list);
 209	INIT_LIST_HEAD(&entry->trans_list);
 210
 211	trace_btrfs_ordered_extent_add(inode, entry);
 212
 213	spin_lock_irq(&tree->lock);
 214	node = tree_insert(&tree->tree, file_offset,
 215			   &entry->rb_node);
 216	if (node)
 217		ordered_data_tree_panic(inode, -EEXIST, file_offset);
 
 
 218	spin_unlock_irq(&tree->lock);
 219
 220	spin_lock(&root->ordered_extent_lock);
 221	list_add_tail(&entry->root_extent_list,
 222		      &root->ordered_extents);
 223	root->nr_ordered_extents++;
 224	if (root->nr_ordered_extents == 1) {
 225		spin_lock(&fs_info->ordered_root_lock);
 226		BUG_ON(!list_empty(&root->ordered_root));
 227		list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 228		spin_unlock(&fs_info->ordered_root_lock);
 229	}
 230	spin_unlock(&root->ordered_extent_lock);
 231
 232	/*
 233	 * We don't need the count_max_extents here, we can assume that all of
 234	 * that work has been done at higher layers, so this is truly the
 235	 * smallest the extent is going to get.
 236	 */
 237	spin_lock(&BTRFS_I(inode)->lock);
 238	btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
 239	spin_unlock(&BTRFS_I(inode)->lock);
 240
 241	return 0;
 242}
 243
 244int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 245			     u64 start, u64 len, u64 disk_len, int type)
 246{
 247	return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 248					  disk_len, type, 0,
 
 
 
 
 249					  BTRFS_COMPRESS_NONE);
 250}
 251
 252int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
 253				 u64 start, u64 len, u64 disk_len, int type)
 254{
 255	return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 256					  disk_len, type, 1,
 
 
 
 
 257					  BTRFS_COMPRESS_NONE);
 258}
 259
 260int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
 261				      u64 start, u64 len, u64 disk_len,
 262				      int type, int compress_type)
 263{
 264	return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 265					  disk_len, type, 0,
 
 
 266					  compress_type);
 267}
 268
 269/*
 270 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 271 * when an ordered extent is finished.  If the list covers more than one
 272 * ordered extent, it is split across multiples.
 273 */
 274void btrfs_add_ordered_sum(struct inode *inode,
 275			   struct btrfs_ordered_extent *entry,
 276			   struct btrfs_ordered_sum *sum)
 277{
 278	struct btrfs_ordered_inode_tree *tree;
 279
 280	tree = &BTRFS_I(inode)->ordered_tree;
 281	spin_lock_irq(&tree->lock);
 282	list_add_tail(&sum->list, &entry->list);
 283	spin_unlock_irq(&tree->lock);
 284}
 285
 286/*
 287 * this is used to account for finished IO across a given range
 288 * of the file.  The IO may span ordered extents.  If
 289 * a given ordered_extent is completely done, 1 is returned, otherwise
 290 * 0.
 291 *
 292 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
 293 * to make sure this function only returns 1 once for a given ordered extent.
 
 
 
 
 
 
 294 *
 295 * file_offset is updated to one byte past the range that is recorded as
 296 * complete.  This allows you to walk forward in the file.
 297 */
 298int btrfs_dec_test_first_ordered_pending(struct inode *inode,
 299				   struct btrfs_ordered_extent **cached,
 300				   u64 *file_offset, u64 io_size, int uptodate)
 301{
 302	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 303	struct btrfs_ordered_inode_tree *tree;
 
 
 304	struct rb_node *node;
 305	struct btrfs_ordered_extent *entry = NULL;
 306	int ret;
 307	unsigned long flags;
 308	u64 dec_end;
 309	u64 dec_start;
 310	u64 to_dec;
 
 
 
 
 
 
 
 311
 312	tree = &BTRFS_I(inode)->ordered_tree;
 313	spin_lock_irqsave(&tree->lock, flags);
 314	node = tree_search(tree, *file_offset);
 315	if (!node) {
 316		ret = 1;
 317		goto out;
 318	}
 319
 320	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 321	if (!offset_in_entry(entry, *file_offset)) {
 322		ret = 1;
 323		goto out;
 324	}
 325
 326	dec_start = max(*file_offset, entry->file_offset);
 327	dec_end = min(*file_offset + io_size, entry->file_offset +
 328		      entry->len);
 329	*file_offset = dec_end;
 330	if (dec_start > dec_end) {
 331		btrfs_crit(fs_info, "bad ordering dec_start %llu end %llu",
 332			   dec_start, dec_end);
 333	}
 334	to_dec = dec_end - dec_start;
 335	if (to_dec > entry->bytes_left) {
 336		btrfs_crit(fs_info,
 337			   "bad ordered accounting left %llu size %llu",
 338			   entry->bytes_left, to_dec);
 339	}
 340	entry->bytes_left -= to_dec;
 341	if (!uptodate)
 342		set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 343
 344	if (entry->bytes_left == 0) {
 345		ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 
 
 346		/*
 347		 * Implicit memory barrier after test_and_set_bit
 
 
 348		 */
 349		if (waitqueue_active(&entry->wait))
 350			wake_up(&entry->wait);
 351	} else {
 352		ret = 1;
 353	}
 354out:
 355	if (!ret && cached && entry) {
 356		*cached = entry;
 357		refcount_inc(&entry->refs);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 358	}
 359	spin_unlock_irqrestore(&tree->lock, flags);
 360	return ret == 0;
 361}
 362
 363/*
 364 * this is used to account for finished IO across a given range
 365 * of the file.  The IO should not span ordered extents.  If
 366 * a given ordered_extent is completely done, 1 is returned, otherwise
 367 * 0.
 
 
 
 
 
 368 *
 369 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
 370 * to make sure this function only returns 1 once for a given ordered extent.
 
 
 
 
 371 */
 372int btrfs_dec_test_ordered_pending(struct inode *inode,
 373				   struct btrfs_ordered_extent **cached,
 374				   u64 file_offset, u64 io_size, int uptodate)
 375{
 376	struct btrfs_ordered_inode_tree *tree;
 377	struct rb_node *node;
 378	struct btrfs_ordered_extent *entry = NULL;
 379	unsigned long flags;
 380	int ret;
 381
 382	tree = &BTRFS_I(inode)->ordered_tree;
 383	spin_lock_irqsave(&tree->lock, flags);
 384	if (cached && *cached) {
 385		entry = *cached;
 386		goto have_entry;
 387	}
 388
 389	node = tree_search(tree, file_offset);
 390	if (!node) {
 391		ret = 1;
 392		goto out;
 393	}
 394
 395	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 396have_entry:
 397	if (!offset_in_entry(entry, file_offset)) {
 398		ret = 1;
 399		goto out;
 400	}
 401
 402	if (io_size > entry->bytes_left) {
 403		btrfs_crit(BTRFS_I(inode)->root->fs_info,
 404			   "bad ordered accounting left %llu size %llu",
 405		       entry->bytes_left, io_size);
 406	}
 407	entry->bytes_left -= io_size;
 408	if (!uptodate)
 409		set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 410
 411	if (entry->bytes_left == 0) {
 412		ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 413		/*
 414		 * Implicit memory barrier after test_and_set_bit
 
 415		 */
 416		if (waitqueue_active(&entry->wait))
 417			wake_up(&entry->wait);
 418	} else {
 419		ret = 1;
 420	}
 421out:
 422	if (!ret && cached && entry) {
 423		*cached = entry;
 424		refcount_inc(&entry->refs);
 425	}
 426	spin_unlock_irqrestore(&tree->lock, flags);
 427	return ret == 0;
 428}
 429
 430/* Needs to either be called under a log transaction or the log_mutex */
 431void btrfs_get_logged_extents(struct btrfs_inode *inode,
 432			      struct list_head *logged_list,
 433			      const loff_t start,
 434			      const loff_t end)
 435{
 436	struct btrfs_ordered_inode_tree *tree;
 437	struct btrfs_ordered_extent *ordered;
 438	struct rb_node *n;
 439	struct rb_node *prev;
 440
 441	tree = &inode->ordered_tree;
 442	spin_lock_irq(&tree->lock);
 443	n = __tree_search(&tree->tree, end, &prev);
 444	if (!n)
 445		n = prev;
 446	for (; n; n = rb_prev(n)) {
 447		ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 448		if (ordered->file_offset > end)
 449			continue;
 450		if (entry_end(ordered) <= start)
 451			break;
 452		if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 453			continue;
 454		list_add(&ordered->log_list, logged_list);
 455		refcount_inc(&ordered->refs);
 456	}
 457	spin_unlock_irq(&tree->lock);
 458}
 459
 460void btrfs_put_logged_extents(struct list_head *logged_list)
 461{
 462	struct btrfs_ordered_extent *ordered;
 463
 464	while (!list_empty(logged_list)) {
 465		ordered = list_first_entry(logged_list,
 466					   struct btrfs_ordered_extent,
 467					   log_list);
 468		list_del_init(&ordered->log_list);
 469		btrfs_put_ordered_extent(ordered);
 470	}
 471}
 472
 473void btrfs_submit_logged_extents(struct list_head *logged_list,
 474				 struct btrfs_root *log)
 475{
 476	int index = log->log_transid % 2;
 477
 478	spin_lock_irq(&log->log_extents_lock[index]);
 479	list_splice_tail(logged_list, &log->logged_list[index]);
 480	spin_unlock_irq(&log->log_extents_lock[index]);
 481}
 482
 483void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,
 484			       struct btrfs_root *log, u64 transid)
 485{
 486	struct btrfs_ordered_extent *ordered;
 487	int index = transid % 2;
 488
 489	spin_lock_irq(&log->log_extents_lock[index]);
 490	while (!list_empty(&log->logged_list[index])) {
 491		struct inode *inode;
 492		ordered = list_first_entry(&log->logged_list[index],
 493					   struct btrfs_ordered_extent,
 494					   log_list);
 495		list_del_init(&ordered->log_list);
 496		inode = ordered->inode;
 497		spin_unlock_irq(&log->log_extents_lock[index]);
 498
 499		if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
 500		    !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
 501			u64 start = ordered->file_offset;
 502			u64 end = ordered->file_offset + ordered->len - 1;
 503
 504			WARN_ON(!inode);
 505			filemap_fdatawrite_range(inode->i_mapping, start, end);
 506		}
 507		wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE,
 508						   &ordered->flags));
 509
 510		/*
 511		 * In order to keep us from losing our ordered extent
 512		 * information when committing the transaction we have to make
 513		 * sure that any logged extents are completed when we go to
 514		 * commit the transaction.  To do this we simply increase the
 515		 * current transactions pending_ordered counter and decrement it
 516		 * when the ordered extent completes.
 517		 */
 518		if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
 519			struct btrfs_ordered_inode_tree *tree;
 520
 521			tree = &BTRFS_I(inode)->ordered_tree;
 522			spin_lock_irq(&tree->lock);
 523			if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
 524				set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
 525				atomic_inc(&trans->transaction->pending_ordered);
 526			}
 527			spin_unlock_irq(&tree->lock);
 528		}
 529		btrfs_put_ordered_extent(ordered);
 530		spin_lock_irq(&log->log_extents_lock[index]);
 531	}
 532	spin_unlock_irq(&log->log_extents_lock[index]);
 533}
 534
 535void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid)
 536{
 537	struct btrfs_ordered_extent *ordered;
 538	int index = transid % 2;
 539
 540	spin_lock_irq(&log->log_extents_lock[index]);
 541	while (!list_empty(&log->logged_list[index])) {
 542		ordered = list_first_entry(&log->logged_list[index],
 543					   struct btrfs_ordered_extent,
 544					   log_list);
 545		list_del_init(&ordered->log_list);
 546		spin_unlock_irq(&log->log_extents_lock[index]);
 547		btrfs_put_ordered_extent(ordered);
 548		spin_lock_irq(&log->log_extents_lock[index]);
 549	}
 550	spin_unlock_irq(&log->log_extents_lock[index]);
 551}
 552
 553/*
 554 * used to drop a reference on an ordered extent.  This will free
 555 * the extent if the last reference is dropped
 556 */
 557void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 558{
 559	struct list_head *cur;
 560	struct btrfs_ordered_sum *sum;
 561
 562	trace_btrfs_ordered_extent_put(entry->inode, entry);
 563
 564	if (refcount_dec_and_test(&entry->refs)) {
 565		ASSERT(list_empty(&entry->log_list));
 566		ASSERT(list_empty(&entry->trans_list));
 567		ASSERT(list_empty(&entry->root_extent_list));
 
 568		ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 569		if (entry->inode)
 570			btrfs_add_delayed_iput(entry->inode);
 571		while (!list_empty(&entry->list)) {
 572			cur = entry->list.next;
 573			sum = list_entry(cur, struct btrfs_ordered_sum, list);
 574			list_del(&sum->list);
 575			kfree(sum);
 576		}
 577		kmem_cache_free(btrfs_ordered_extent_cache, entry);
 578	}
 579}
 580
 581/*
 582 * remove an ordered extent from the tree.  No references are dropped
 583 * and waiters are woken up.
 584 */
 585void btrfs_remove_ordered_extent(struct inode *inode,
 586				 struct btrfs_ordered_extent *entry)
 587{
 588	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 589	struct btrfs_ordered_inode_tree *tree;
 590	struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
 591	struct btrfs_root *root = btrfs_inode->root;
 
 592	struct rb_node *node;
 593	bool dec_pending_ordered = false;
 594
 595	/* This is paired with btrfs_add_ordered_extent. */
 596	spin_lock(&btrfs_inode->lock);
 597	btrfs_mod_outstanding_extents(btrfs_inode, -1);
 598	spin_unlock(&btrfs_inode->lock);
 599	if (root != fs_info->tree_root)
 600		btrfs_delalloc_release_metadata(btrfs_inode, entry->len, false);
 
 
 
 
 601
 602	tree = &btrfs_inode->ordered_tree;
 603	spin_lock_irq(&tree->lock);
 604	node = &entry->rb_node;
 605	rb_erase(node, &tree->tree);
 606	RB_CLEAR_NODE(node);
 607	if (tree->last == node)
 608		tree->last = NULL;
 609	set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 610	if (test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags))
 611		dec_pending_ordered = true;
 612	spin_unlock_irq(&tree->lock);
 613
 614	/*
 615	 * The current running transaction is waiting on us, we need to let it
 616	 * know that we're complete and wake it up.
 617	 */
 618	if (dec_pending_ordered) {
 619		struct btrfs_transaction *trans;
 620
 621		/*
 622		 * The checks for trans are just a formality, it should be set,
 623		 * but if it isn't we don't want to deref/assert under the spin
 624		 * lock, so be nice and check if trans is set, but ASSERT() so
 625		 * if it isn't set a developer will notice.
 626		 */
 627		spin_lock(&fs_info->trans_lock);
 628		trans = fs_info->running_transaction;
 629		if (trans)
 630			refcount_inc(&trans->use_count);
 631		spin_unlock(&fs_info->trans_lock);
 632
 633		ASSERT(trans);
 634		if (trans) {
 635			if (atomic_dec_and_test(&trans->pending_ordered))
 636				wake_up(&trans->pending_wait);
 637			btrfs_put_transaction(trans);
 638		}
 639	}
 640
 641	spin_lock(&root->ordered_extent_lock);
 642	list_del_init(&entry->root_extent_list);
 643	root->nr_ordered_extents--;
 644
 645	trace_btrfs_ordered_extent_remove(inode, entry);
 646
 647	if (!root->nr_ordered_extents) {
 648		spin_lock(&fs_info->ordered_root_lock);
 649		BUG_ON(list_empty(&root->ordered_root));
 650		list_del_init(&root->ordered_root);
 651		spin_unlock(&fs_info->ordered_root_lock);
 652	}
 653	spin_unlock(&root->ordered_extent_lock);
 654	wake_up(&entry->wait);
 655}
 656
 657static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 658{
 659	struct btrfs_ordered_extent *ordered;
 660
 661	ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 662	btrfs_start_ordered_extent(ordered->inode, ordered, 1);
 663	complete(&ordered->completion);
 664}
 665
 666/*
 667 * wait for all the ordered extents in a root.  This is done when balancing
 668 * space between drives.
 669 */
 670u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 671			       const u64 range_start, const u64 range_len)
 672{
 673	struct btrfs_fs_info *fs_info = root->fs_info;
 674	LIST_HEAD(splice);
 675	LIST_HEAD(skipped);
 676	LIST_HEAD(works);
 677	struct btrfs_ordered_extent *ordered, *next;
 678	u64 count = 0;
 679	const u64 range_end = range_start + range_len;
 680
 681	mutex_lock(&root->ordered_extent_mutex);
 682	spin_lock(&root->ordered_extent_lock);
 683	list_splice_init(&root->ordered_extents, &splice);
 684	while (!list_empty(&splice) && nr) {
 685		ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 686					   root_extent_list);
 687
 688		if (range_end <= ordered->start ||
 689		    ordered->start + ordered->disk_len <= range_start) {
 690			list_move_tail(&ordered->root_extent_list, &skipped);
 691			cond_resched_lock(&root->ordered_extent_lock);
 692			continue;
 693		}
 694
 695		list_move_tail(&ordered->root_extent_list,
 696			       &root->ordered_extents);
 697		refcount_inc(&ordered->refs);
 698		spin_unlock(&root->ordered_extent_lock);
 699
 700		btrfs_init_work(&ordered->flush_work,
 701				btrfs_flush_delalloc_helper,
 702				btrfs_run_ordered_extent_work, NULL, NULL);
 703		list_add_tail(&ordered->work_list, &works);
 704		btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 705
 706		cond_resched();
 707		spin_lock(&root->ordered_extent_lock);
 708		if (nr != U64_MAX)
 709			nr--;
 710		count++;
 711	}
 712	list_splice_tail(&skipped, &root->ordered_extents);
 713	list_splice_tail(&splice, &root->ordered_extents);
 714	spin_unlock(&root->ordered_extent_lock);
 715
 716	list_for_each_entry_safe(ordered, next, &works, work_list) {
 717		list_del_init(&ordered->work_list);
 718		wait_for_completion(&ordered->completion);
 719		btrfs_put_ordered_extent(ordered);
 720		cond_resched();
 721	}
 722	mutex_unlock(&root->ordered_extent_mutex);
 723
 724	return count;
 725}
 726
 727u64 btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 728			     const u64 range_start, const u64 range_len)
 729{
 730	struct btrfs_root *root;
 731	struct list_head splice;
 732	u64 total_done = 0;
 733	u64 done;
 734
 735	INIT_LIST_HEAD(&splice);
 736
 737	mutex_lock(&fs_info->ordered_operations_mutex);
 738	spin_lock(&fs_info->ordered_root_lock);
 739	list_splice_init(&fs_info->ordered_roots, &splice);
 740	while (!list_empty(&splice) && nr) {
 741		root = list_first_entry(&splice, struct btrfs_root,
 742					ordered_root);
 743		root = btrfs_grab_fs_root(root);
 744		BUG_ON(!root);
 745		list_move_tail(&root->ordered_root,
 746			       &fs_info->ordered_roots);
 747		spin_unlock(&fs_info->ordered_root_lock);
 748
 749		done = btrfs_wait_ordered_extents(root, nr,
 750						  range_start, range_len);
 751		btrfs_put_fs_root(root);
 752		total_done += done;
 753
 754		spin_lock(&fs_info->ordered_root_lock);
 755		if (nr != U64_MAX) {
 756			nr -= done;
 757		}
 758	}
 759	list_splice_tail(&splice, &fs_info->ordered_roots);
 760	spin_unlock(&fs_info->ordered_root_lock);
 761	mutex_unlock(&fs_info->ordered_operations_mutex);
 762
 763	return total_done;
 764}
 765
 766/*
 767 * Used to start IO or wait for a given ordered extent to finish.
 768 *
 769 * If wait is one, this effectively waits on page writeback for all the pages
 770 * in the extent, and it waits on the io completion code to insert
 771 * metadata into the btree corresponding to the extent
 772 */
 773void btrfs_start_ordered_extent(struct inode *inode,
 774				       struct btrfs_ordered_extent *entry,
 775				       int wait)
 776{
 777	u64 start = entry->file_offset;
 778	u64 end = start + entry->len - 1;
 
 779
 780	trace_btrfs_ordered_extent_start(inode, entry);
 781
 782	/*
 783	 * pages in the range can be dirty, clean or writeback.  We
 784	 * start IO on any dirty ones so the wait doesn't stall waiting
 785	 * for the flusher thread to find them
 786	 */
 787	if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 788		filemap_fdatawrite_range(inode->i_mapping, start, end);
 789	if (wait) {
 790		wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 791						 &entry->flags));
 792	}
 793}
 794
 795/*
 796 * Used to wait on ordered extents across a large range of bytes.
 797 */
 798int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 799{
 800	int ret = 0;
 801	int ret_wb = 0;
 802	u64 end;
 803	u64 orig_end;
 804	struct btrfs_ordered_extent *ordered;
 805
 806	if (start + len < start) {
 807		orig_end = INT_LIMIT(loff_t);
 808	} else {
 809		orig_end = start + len - 1;
 810		if (orig_end > INT_LIMIT(loff_t))
 811			orig_end = INT_LIMIT(loff_t);
 812	}
 813
 814	/* start IO across the range first to instantiate any delalloc
 815	 * extents
 816	 */
 817	ret = btrfs_fdatawrite_range(inode, start, orig_end);
 818	if (ret)
 819		return ret;
 820
 821	/*
 822	 * If we have a writeback error don't return immediately. Wait first
 823	 * for any ordered extents that haven't completed yet. This is to make
 824	 * sure no one can dirty the same page ranges and call writepages()
 825	 * before the ordered extents complete - to avoid failures (-EEXIST)
 826	 * when adding the new ordered extents to the ordered tree.
 827	 */
 828	ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 829
 830	end = orig_end;
 831	while (1) {
 832		ordered = btrfs_lookup_first_ordered_extent(inode, end);
 833		if (!ordered)
 834			break;
 835		if (ordered->file_offset > orig_end) {
 836			btrfs_put_ordered_extent(ordered);
 837			break;
 838		}
 839		if (ordered->file_offset + ordered->len <= start) {
 840			btrfs_put_ordered_extent(ordered);
 841			break;
 842		}
 843		btrfs_start_ordered_extent(inode, ordered, 1);
 844		end = ordered->file_offset;
 
 
 
 
 
 845		if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 846			ret = -EIO;
 847		btrfs_put_ordered_extent(ordered);
 848		if (ret || end == 0 || end == start)
 849			break;
 850		end--;
 851	}
 852	return ret_wb ? ret_wb : ret;
 853}
 854
 855/*
 856 * find an ordered extent corresponding to file_offset.  return NULL if
 857 * nothing is found, otherwise take a reference on the extent and return it
 858 */
 859struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 860							 u64 file_offset)
 861{
 862	struct btrfs_ordered_inode_tree *tree;
 863	struct rb_node *node;
 864	struct btrfs_ordered_extent *entry = NULL;
 
 865
 866	tree = &BTRFS_I(inode)->ordered_tree;
 867	spin_lock_irq(&tree->lock);
 868	node = tree_search(tree, file_offset);
 869	if (!node)
 870		goto out;
 871
 872	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 873	if (!offset_in_entry(entry, file_offset))
 874		entry = NULL;
 875	if (entry)
 876		refcount_inc(&entry->refs);
 877out:
 878	spin_unlock_irq(&tree->lock);
 879	return entry;
 880}
 881
 882/* Since the DIO code tries to lock a wide area we need to look for any ordered
 883 * extents that exist in the range, rather than just the start of the range.
 884 */
 885struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 886		struct btrfs_inode *inode, u64 file_offset, u64 len)
 887{
 888	struct btrfs_ordered_inode_tree *tree;
 889	struct rb_node *node;
 890	struct btrfs_ordered_extent *entry = NULL;
 891
 892	tree = &inode->ordered_tree;
 893	spin_lock_irq(&tree->lock);
 894	node = tree_search(tree, file_offset);
 895	if (!node) {
 896		node = tree_search(tree, file_offset + len);
 897		if (!node)
 898			goto out;
 899	}
 900
 901	while (1) {
 902		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 903		if (range_overlaps(entry, file_offset, len))
 904			break;
 905
 906		if (entry->file_offset >= file_offset + len) {
 907			entry = NULL;
 908			break;
 909		}
 910		entry = NULL;
 911		node = rb_next(node);
 912		if (!node)
 913			break;
 914	}
 915out:
 916	if (entry)
 917		refcount_inc(&entry->refs);
 918	spin_unlock_irq(&tree->lock);
 919	return entry;
 920}
 921
 922bool btrfs_have_ordered_extents_in_range(struct inode *inode,
 923					 u64 file_offset,
 924					 u64 len)
 925{
 926	struct btrfs_ordered_extent *oe;
 927
 928	oe = btrfs_lookup_ordered_range(BTRFS_I(inode), file_offset, len);
 929	if (oe) {
 930		btrfs_put_ordered_extent(oe);
 931		return true;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 932	}
 933	return false;
 934}
 935
 936/*
 937 * lookup and return any extent before 'file_offset'.  NULL is returned
 938 * if none is found
 939 */
 940struct btrfs_ordered_extent *
 941btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
 942{
 943	struct btrfs_ordered_inode_tree *tree;
 944	struct rb_node *node;
 945	struct btrfs_ordered_extent *entry = NULL;
 946
 947	tree = &BTRFS_I(inode)->ordered_tree;
 948	spin_lock_irq(&tree->lock);
 949	node = tree_search(tree, file_offset);
 950	if (!node)
 951		goto out;
 952
 953	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 954	refcount_inc(&entry->refs);
 955out:
 956	spin_unlock_irq(&tree->lock);
 957	return entry;
 958}
 959
 960/*
 961 * After an extent is done, call this to conditionally update the on disk
 962 * i_size.  i_size is updated to cover any fully written part of the file.
 
 
 
 
 
 963 */
 964int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 965				struct btrfs_ordered_extent *ordered)
 966{
 967	struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 968	u64 disk_i_size;
 969	u64 new_i_size;
 970	u64 i_size = i_size_read(inode);
 971	struct rb_node *node;
 972	struct rb_node *prev = NULL;
 973	struct btrfs_ordered_extent *test;
 974	int ret = 1;
 975	u64 orig_offset = offset;
 976
 977	spin_lock_irq(&tree->lock);
 978	if (ordered) {
 979		offset = entry_end(ordered);
 980		if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
 981			offset = min(offset,
 982				     ordered->file_offset +
 983				     ordered->truncated_len);
 984	} else {
 985		offset = ALIGN(offset, btrfs_inode_sectorsize(inode));
 986	}
 987	disk_i_size = BTRFS_I(inode)->disk_i_size;
 988
 989	/*
 990	 * truncate file.
 991	 * If ordered is not NULL, then this is called from endio and
 992	 * disk_i_size will be updated by either truncate itself or any
 993	 * in-flight IOs which are inside the disk_i_size.
 994	 *
 995	 * Because btrfs_setsize() may set i_size with disk_i_size if truncate
 996	 * fails somehow, we need to make sure we have a precise disk_i_size by
 997	 * updating it as usual.
 998	 *
 999	 */
1000	if (!ordered && disk_i_size > i_size) {
1001		BTRFS_I(inode)->disk_i_size = orig_offset;
1002		ret = 0;
1003		goto out;
1004	}
1005
1006	/*
1007	 * if the disk i_size is already at the inode->i_size, or
1008	 * this ordered extent is inside the disk i_size, we're done
1009	 */
1010	if (disk_i_size == i_size)
1011		goto out;
1012
1013	/*
1014	 * We still need to update disk_i_size if outstanding_isize is greater
1015	 * than disk_i_size.
1016	 */
1017	if (offset <= disk_i_size &&
1018	    (!ordered || ordered->outstanding_isize <= disk_i_size))
 
 
 
 
 
 
 
 
1019		goto out;
 
1020
1021	/*
1022	 * walk backward from this ordered extent to disk_i_size.
1023	 * if we find an ordered extent then we can't update disk i_size
1024	 * yet
1025	 */
1026	if (ordered) {
1027		node = rb_prev(&ordered->rb_node);
1028	} else {
1029		prev = tree_search(tree, offset);
1030		/*
1031		 * we insert file extents without involving ordered struct,
1032		 * so there should be no ordered struct cover this offset
1033		 */
1034		if (prev) {
1035			test = rb_entry(prev, struct btrfs_ordered_extent,
1036					rb_node);
1037			BUG_ON(offset_in_entry(test, offset));
1038		}
1039		node = prev;
1040	}
1041	for (; node; node = rb_prev(node)) {
1042		test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1043
1044		/* We treat this entry as if it doesn't exist */
1045		if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
1046			continue;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1047
1048		if (entry_end(test) <= disk_i_size)
1049			break;
1050		if (test->file_offset >= i_size)
1051			break;
1052
1053		/*
1054		 * We don't update disk_i_size now, so record this undealt
1055		 * i_size. Or we will not know the real i_size.
1056		 */
1057		if (test->outstanding_isize < offset)
1058			test->outstanding_isize = offset;
1059		if (ordered &&
1060		    ordered->outstanding_isize > test->outstanding_isize)
1061			test->outstanding_isize = ordered->outstanding_isize;
1062		goto out;
 
 
 
 
 
 
 
1063	}
1064	new_i_size = min_t(u64, offset, i_size);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1065
1066	/*
1067	 * Some ordered extents may completed before the current one, and
1068	 * we hold the real i_size in ->outstanding_isize.
1069	 */
1070	if (ordered && ordered->outstanding_isize > new_i_size)
1071		new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
1072	BTRFS_I(inode)->disk_i_size = new_i_size;
1073	ret = 0;
1074out:
1075	/*
1076	 * We need to do this because we can't remove ordered extents until
1077	 * after the i_disk_size has been updated and then the inode has been
1078	 * updated to reflect the change, so we need to tell anybody who finds
1079	 * this ordered extent that we've already done all the real work, we
1080	 * just haven't completed all the other work.
1081	 */
1082	if (ordered)
1083		set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
1084	spin_unlock_irq(&tree->lock);
 
 
 
 
 
 
 
 
 
 
 
 
1085	return ret;
1086}
1087
1088/*
1089 * search the ordered extents for one corresponding to 'offset' and
1090 * try to find a checksum.  This is used because we allow pages to
1091 * be reclaimed before their checksum is actually put into the btree
1092 */
1093int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
1094			   u32 *sum, int len)
1095{
1096	struct btrfs_ordered_sum *ordered_sum;
1097	struct btrfs_ordered_extent *ordered;
1098	struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1099	unsigned long num_sectors;
1100	unsigned long i;
1101	u32 sectorsize = btrfs_inode_sectorsize(inode);
1102	int index = 0;
1103
1104	ordered = btrfs_lookup_ordered_extent(inode, offset);
1105	if (!ordered)
1106		return 0;
1107
1108	spin_lock_irq(&tree->lock);
1109	list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
1110		if (disk_bytenr >= ordered_sum->bytenr &&
1111		    disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
1112			i = (disk_bytenr - ordered_sum->bytenr) >>
1113			    inode->i_sb->s_blocksize_bits;
1114			num_sectors = ordered_sum->len >>
1115				      inode->i_sb->s_blocksize_bits;
1116			num_sectors = min_t(int, len - index, num_sectors - i);
1117			memcpy(sum + index, ordered_sum->sums + i,
1118			       num_sectors);
1119
1120			index += (int)num_sectors;
1121			if (index == len)
1122				goto out;
1123			disk_bytenr += num_sectors * sectorsize;
1124		}
1125	}
1126out:
 
 
1127	spin_unlock_irq(&tree->lock);
1128	btrfs_put_ordered_extent(ordered);
1129	return index;
 
 
 
 
 
 
1130}
1131
1132int __init ordered_data_init(void)
1133{
1134	btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1135				     sizeof(struct btrfs_ordered_extent), 0,
1136				     SLAB_MEM_SPREAD,
1137				     NULL);
1138	if (!btrfs_ordered_extent_cache)
1139		return -ENOMEM;
1140
1141	return 0;
1142}
1143
1144void __cold ordered_data_exit(void)
1145{
1146	kmem_cache_destroy(btrfs_ordered_extent_cache);
1147}
v5.14.15
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2007 Oracle.  All rights reserved.
   4 */
   5
   6#include <linux/slab.h>
   7#include <linux/blkdev.h>
   8#include <linux/writeback.h>
   9#include <linux/sched/mm.h>
  10#include "misc.h"
  11#include "ctree.h"
  12#include "transaction.h"
  13#include "btrfs_inode.h"
  14#include "extent_io.h"
  15#include "disk-io.h"
  16#include "compression.h"
  17#include "delalloc-space.h"
  18#include "qgroup.h"
  19#include "subpage.h"
  20
  21static struct kmem_cache *btrfs_ordered_extent_cache;
  22
  23static u64 entry_end(struct btrfs_ordered_extent *entry)
  24{
  25	if (entry->file_offset + entry->num_bytes < entry->file_offset)
  26		return (u64)-1;
  27	return entry->file_offset + entry->num_bytes;
  28}
  29
  30/* returns NULL if the insertion worked, or it returns the node it did find
  31 * in the tree
  32 */
  33static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
  34				   struct rb_node *node)
  35{
  36	struct rb_node **p = &root->rb_node;
  37	struct rb_node *parent = NULL;
  38	struct btrfs_ordered_extent *entry;
  39
  40	while (*p) {
  41		parent = *p;
  42		entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
  43
  44		if (file_offset < entry->file_offset)
  45			p = &(*p)->rb_left;
  46		else if (file_offset >= entry_end(entry))
  47			p = &(*p)->rb_right;
  48		else
  49			return parent;
  50	}
  51
  52	rb_link_node(node, parent, p);
  53	rb_insert_color(node, root);
  54	return NULL;
  55}
  56
 
 
 
 
 
 
 
 
  57/*
  58 * look for a given offset in the tree, and if it can't be found return the
  59 * first lesser offset
  60 */
  61static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
  62				     struct rb_node **prev_ret)
  63{
  64	struct rb_node *n = root->rb_node;
  65	struct rb_node *prev = NULL;
  66	struct rb_node *test;
  67	struct btrfs_ordered_extent *entry;
  68	struct btrfs_ordered_extent *prev_entry = NULL;
  69
  70	while (n) {
  71		entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
  72		prev = n;
  73		prev_entry = entry;
  74
  75		if (file_offset < entry->file_offset)
  76			n = n->rb_left;
  77		else if (file_offset >= entry_end(entry))
  78			n = n->rb_right;
  79		else
  80			return n;
  81	}
  82	if (!prev_ret)
  83		return NULL;
  84
  85	while (prev && file_offset >= entry_end(prev_entry)) {
  86		test = rb_next(prev);
  87		if (!test)
  88			break;
  89		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
  90				      rb_node);
  91		if (file_offset < entry_end(prev_entry))
  92			break;
  93
  94		prev = test;
  95	}
  96	if (prev)
  97		prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
  98				      rb_node);
  99	while (prev && file_offset < entry_end(prev_entry)) {
 100		test = rb_prev(prev);
 101		if (!test)
 102			break;
 103		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 104				      rb_node);
 105		prev = test;
 106	}
 107	*prev_ret = prev;
 108	return NULL;
 109}
 110
 
 
 
 
 
 
 
 
 
 
 
 111static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
 112			  u64 len)
 113{
 114	if (file_offset + len <= entry->file_offset ||
 115	    entry->file_offset + entry->num_bytes <= file_offset)
 116		return 0;
 117	return 1;
 118}
 119
 120/*
 121 * look find the first ordered struct that has this offset, otherwise
 122 * the first one less than this offset
 123 */
 124static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
 125					  u64 file_offset)
 126{
 127	struct rb_root *root = &tree->tree;
 128	struct rb_node *prev = NULL;
 129	struct rb_node *ret;
 130	struct btrfs_ordered_extent *entry;
 131
 132	if (tree->last) {
 133		entry = rb_entry(tree->last, struct btrfs_ordered_extent,
 134				 rb_node);
 135		if (in_range(file_offset, entry->file_offset, entry->num_bytes))
 136			return tree->last;
 137	}
 138	ret = __tree_search(root, file_offset, &prev);
 139	if (!ret)
 140		ret = prev;
 141	if (ret)
 142		tree->last = ret;
 143	return ret;
 144}
 145
 146/*
 147 * Allocate and add a new ordered_extent into the per-inode tree.
 
 
 
 
 
 148 *
 149 * The tree is given a single reference on the ordered extent that was
 150 * inserted.
 151 */
 152static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
 153				      u64 disk_bytenr, u64 num_bytes,
 154				      u64 disk_num_bytes, int type, int dio,
 155				      int compress_type)
 156{
 157	struct btrfs_root *root = inode->root;
 158	struct btrfs_fs_info *fs_info = root->fs_info;
 159	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 160	struct rb_node *node;
 161	struct btrfs_ordered_extent *entry;
 162	int ret;
 163
 164	if (type == BTRFS_ORDERED_NOCOW || type == BTRFS_ORDERED_PREALLOC) {
 165		/* For nocow write, we can release the qgroup rsv right now */
 166		ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
 167		if (ret < 0)
 168			return ret;
 169		ret = 0;
 170	} else {
 171		/*
 172		 * The ordered extent has reserved qgroup space, release now
 173		 * and pass the reserved number for qgroup_record to free.
 174		 */
 175		ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes);
 176		if (ret < 0)
 177			return ret;
 178	}
 179	entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 180	if (!entry)
 181		return -ENOMEM;
 182
 183	entry->file_offset = file_offset;
 184	entry->disk_bytenr = disk_bytenr;
 185	entry->num_bytes = num_bytes;
 186	entry->disk_num_bytes = disk_num_bytes;
 187	entry->bytes_left = num_bytes;
 188	entry->inode = igrab(&inode->vfs_inode);
 189	entry->compress_type = compress_type;
 190	entry->truncated_len = (u64)-1;
 191	entry->qgroup_rsv = ret;
 192	entry->physical = (u64)-1;
 193
 194	ASSERT(type == BTRFS_ORDERED_REGULAR ||
 195	       type == BTRFS_ORDERED_NOCOW ||
 196	       type == BTRFS_ORDERED_PREALLOC ||
 197	       type == BTRFS_ORDERED_COMPRESSED);
 198	set_bit(type, &entry->flags);
 199
 200	percpu_counter_add_batch(&fs_info->ordered_bytes, num_bytes,
 201				 fs_info->delalloc_batch);
 202
 203	if (dio)
 204		set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
 205
 206	/* one ref for the tree */
 207	refcount_set(&entry->refs, 1);
 208	init_waitqueue_head(&entry->wait);
 209	INIT_LIST_HEAD(&entry->list);
 210	INIT_LIST_HEAD(&entry->log_list);
 211	INIT_LIST_HEAD(&entry->root_extent_list);
 212	INIT_LIST_HEAD(&entry->work_list);
 213	init_completion(&entry->completion);
 
 
 214
 215	trace_btrfs_ordered_extent_add(inode, entry);
 216
 217	spin_lock_irq(&tree->lock);
 218	node = tree_insert(&tree->tree, file_offset,
 219			   &entry->rb_node);
 220	if (node)
 221		btrfs_panic(fs_info, -EEXIST,
 222				"inconsistency in ordered tree at offset %llu",
 223				file_offset);
 224	spin_unlock_irq(&tree->lock);
 225
 226	spin_lock(&root->ordered_extent_lock);
 227	list_add_tail(&entry->root_extent_list,
 228		      &root->ordered_extents);
 229	root->nr_ordered_extents++;
 230	if (root->nr_ordered_extents == 1) {
 231		spin_lock(&fs_info->ordered_root_lock);
 232		BUG_ON(!list_empty(&root->ordered_root));
 233		list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 234		spin_unlock(&fs_info->ordered_root_lock);
 235	}
 236	spin_unlock(&root->ordered_extent_lock);
 237
 238	/*
 239	 * We don't need the count_max_extents here, we can assume that all of
 240	 * that work has been done at higher layers, so this is truly the
 241	 * smallest the extent is going to get.
 242	 */
 243	spin_lock(&inode->lock);
 244	btrfs_mod_outstanding_extents(inode, 1);
 245	spin_unlock(&inode->lock);
 246
 247	return 0;
 248}
 249
 250int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
 251			     u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
 252			     int type)
 253{
 254	ASSERT(type == BTRFS_ORDERED_REGULAR ||
 255	       type == BTRFS_ORDERED_NOCOW ||
 256	       type == BTRFS_ORDERED_PREALLOC);
 257	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
 258					  num_bytes, disk_num_bytes, type, 0,
 259					  BTRFS_COMPRESS_NONE);
 260}
 261
 262int btrfs_add_ordered_extent_dio(struct btrfs_inode *inode, u64 file_offset,
 263				 u64 disk_bytenr, u64 num_bytes,
 264				 u64 disk_num_bytes, int type)
 265{
 266	ASSERT(type == BTRFS_ORDERED_REGULAR ||
 267	       type == BTRFS_ORDERED_NOCOW ||
 268	       type == BTRFS_ORDERED_PREALLOC);
 269	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
 270					  num_bytes, disk_num_bytes, type, 1,
 271					  BTRFS_COMPRESS_NONE);
 272}
 273
 274int btrfs_add_ordered_extent_compress(struct btrfs_inode *inode, u64 file_offset,
 275				      u64 disk_bytenr, u64 num_bytes,
 276				      u64 disk_num_bytes, int compress_type)
 277{
 278	ASSERT(compress_type != BTRFS_COMPRESS_NONE);
 279	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
 280					  num_bytes, disk_num_bytes,
 281					  BTRFS_ORDERED_COMPRESSED, 0,
 282					  compress_type);
 283}
 284
 285/*
 286 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 287 * when an ordered extent is finished.  If the list covers more than one
 288 * ordered extent, it is split across multiples.
 289 */
 290void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 
 291			   struct btrfs_ordered_sum *sum)
 292{
 293	struct btrfs_ordered_inode_tree *tree;
 294
 295	tree = &BTRFS_I(entry->inode)->ordered_tree;
 296	spin_lock_irq(&tree->lock);
 297	list_add_tail(&sum->list, &entry->list);
 298	spin_unlock_irq(&tree->lock);
 299}
 300
 301/*
 302 * Mark all ordered extents io inside the specified range finished.
 
 
 
 303 *
 304 * @page:	 The invovled page for the opeartion.
 305 *		 For uncompressed buffered IO, the page status also needs to be
 306 *		 updated to indicate whether the pending ordered io is finished.
 307 *		 Can be NULL for direct IO and compressed write.
 308 *		 For these cases, callers are ensured they won't execute the
 309 *		 endio function twice.
 310 * @finish_func: The function to be executed when all the IO of an ordered
 311 *		 extent are finished.
 312 *
 313 * This function is called for endio, thus the range must have ordered
 314 * extent(s) coveri it.
 315 */
 316void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
 317				struct page *page, u64 file_offset,
 318				u64 num_bytes, btrfs_func_t finish_func,
 319				bool uptodate)
 320{
 321	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 322	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 323	struct btrfs_workqueue *wq;
 324	struct rb_node *node;
 325	struct btrfs_ordered_extent *entry = NULL;
 
 326	unsigned long flags;
 327	u64 cur = file_offset;
 328
 329	if (btrfs_is_free_space_inode(inode))
 330		wq = fs_info->endio_freespace_worker;
 331	else
 332		wq = fs_info->endio_write_workers;
 333
 334	if (page)
 335		ASSERT(page->mapping && page_offset(page) <= file_offset &&
 336		       file_offset + num_bytes <= page_offset(page) + PAGE_SIZE);
 337
 
 338	spin_lock_irqsave(&tree->lock, flags);
 339	while (cur < file_offset + num_bytes) {
 340		u64 entry_end;
 341		u64 end;
 342		u32 len;
 
 343
 344		node = tree_search(tree, cur);
 345		/* No ordered extents at all */
 346		if (!node)
 347			break;
 
 348
 349		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 350		entry_end = entry->file_offset + entry->num_bytes;
 351		/*
 352		 * |<-- OE --->|  |
 353		 *		  cur
 354		 * Go to next OE.
 355		 */
 356		if (cur >= entry_end) {
 357			node = rb_next(node);
 358			/* No more ordered extents, exit */
 359			if (!node)
 360				break;
 361			entry = rb_entry(node, struct btrfs_ordered_extent,
 362					 rb_node);
 
 
 
 363
 364			/* Go to next ordered extent and continue */
 365			cur = entry->file_offset;
 366			continue;
 367		}
 368		/*
 369		 * |	|<--- OE --->|
 370		 * cur
 371		 * Go to the start of OE.
 372		 */
 373		if (cur < entry->file_offset) {
 374			cur = entry->file_offset;
 375			continue;
 376		}
 377
 378		/*
 379		 * Now we are definitely inside one ordered extent.
 380		 *
 381		 * |<--- OE --->|
 382		 *	|
 383		 *	cur
 384		 */
 385		end = min(entry->file_offset + entry->num_bytes,
 386			  file_offset + num_bytes) - 1;
 387		ASSERT(end + 1 - cur < U32_MAX);
 388		len = end + 1 - cur;
 389
 390		if (page) {
 391			/*
 392			 * Ordered (Private2) bit indicates whether we still
 393			 * have pending io unfinished for the ordered extent.
 394			 *
 395			 * If there's no such bit, we need to skip to next range.
 396			 */
 397			if (!btrfs_page_test_ordered(fs_info, page, cur, len)) {
 398				cur += len;
 399				continue;
 400			}
 401			btrfs_page_clear_ordered(fs_info, page, cur, len);
 402		}
 403
 404		/* Now we're fine to update the accounting */
 405		if (unlikely(len > entry->bytes_left)) {
 406			WARN_ON(1);
 407			btrfs_crit(fs_info,
 408"bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%u left=%llu",
 409				   inode->root->root_key.objectid,
 410				   btrfs_ino(inode),
 411				   entry->file_offset,
 412				   entry->num_bytes,
 413				   len, entry->bytes_left);
 414			entry->bytes_left = 0;
 415		} else {
 416			entry->bytes_left -= len;
 417		}
 418
 419		if (!uptodate)
 420			set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 421
 422		/*
 423		 * All the IO of the ordered extent is finished, we need to queue
 424		 * the finish_func to be executed.
 425		 */
 426		if (entry->bytes_left == 0) {
 427			set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 428			cond_wake_up(&entry->wait);
 429			refcount_inc(&entry->refs);
 430			spin_unlock_irqrestore(&tree->lock, flags);
 431			btrfs_init_work(&entry->work, finish_func, NULL, NULL);
 432			btrfs_queue_work(wq, &entry->work);
 433			spin_lock_irqsave(&tree->lock, flags);
 434		}
 435		cur += len;
 436	}
 437	spin_unlock_irqrestore(&tree->lock, flags);
 
 438}
 439
 440/*
 441 * Finish IO for one ordered extent across a given range.  The range can only
 442 * contain one ordered extent.
 443 *
 444 * @cached:	 The cached ordered extent. If not NULL, we can skip the tree
 445 *               search and use the ordered extent directly.
 446 * 		 Will be also used to store the finished ordered extent.
 447 * @file_offset: File offset for the finished IO
 448 * @io_size:	 Length of the finish IO range
 449 * @uptodate:	 If the IO finishes without problem
 450 *
 451 * Return true if the ordered extent is finished in the range, and update
 452 * @cached.
 453 * Return false otherwise.
 454 *
 455 * NOTE: The range can NOT cross multiple ordered extents.
 456 * Thus caller should ensure the range doesn't cross ordered extents.
 457 */
 458bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 459				    struct btrfs_ordered_extent **cached,
 460				    u64 file_offset, u64 io_size, int uptodate)
 461{
 462	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 463	struct rb_node *node;
 464	struct btrfs_ordered_extent *entry = NULL;
 465	unsigned long flags;
 466	bool finished = false;
 467
 
 468	spin_lock_irqsave(&tree->lock, flags);
 469	if (cached && *cached) {
 470		entry = *cached;
 471		goto have_entry;
 472	}
 473
 474	node = tree_search(tree, file_offset);
 475	if (!node)
 
 476		goto out;
 
 477
 478	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 479have_entry:
 480	if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 
 481		goto out;
 
 482
 483	if (io_size > entry->bytes_left)
 484		btrfs_crit(inode->root->fs_info,
 485			   "bad ordered accounting left %llu size %llu",
 486		       entry->bytes_left, io_size);
 487
 488	entry->bytes_left -= io_size;
 489	if (!uptodate)
 490		set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 491
 492	if (entry->bytes_left == 0) {
 
 493		/*
 494		 * Ensure only one caller can set the flag and finished_ret
 495		 * accordingly
 496		 */
 497		finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 498		/* test_and_set_bit implies a barrier */
 499		cond_wake_up_nomb(&entry->wait);
 
 500	}
 501out:
 502	if (finished && cached && entry) {
 503		*cached = entry;
 504		refcount_inc(&entry->refs);
 505	}
 506	spin_unlock_irqrestore(&tree->lock, flags);
 507	return finished;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 508}
 509
 510/*
 511 * used to drop a reference on an ordered extent.  This will free
 512 * the extent if the last reference is dropped
 513 */
 514void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 515{
 516	struct list_head *cur;
 517	struct btrfs_ordered_sum *sum;
 518
 519	trace_btrfs_ordered_extent_put(BTRFS_I(entry->inode), entry);
 520
 521	if (refcount_dec_and_test(&entry->refs)) {
 
 
 522		ASSERT(list_empty(&entry->root_extent_list));
 523		ASSERT(list_empty(&entry->log_list));
 524		ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 525		if (entry->inode)
 526			btrfs_add_delayed_iput(entry->inode);
 527		while (!list_empty(&entry->list)) {
 528			cur = entry->list.next;
 529			sum = list_entry(cur, struct btrfs_ordered_sum, list);
 530			list_del(&sum->list);
 531			kvfree(sum);
 532		}
 533		kmem_cache_free(btrfs_ordered_extent_cache, entry);
 534	}
 535}
 536
 537/*
 538 * remove an ordered extent from the tree.  No references are dropped
 539 * and waiters are woken up.
 540 */
 541void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
 542				 struct btrfs_ordered_extent *entry)
 543{
 
 544	struct btrfs_ordered_inode_tree *tree;
 
 545	struct btrfs_root *root = btrfs_inode->root;
 546	struct btrfs_fs_info *fs_info = root->fs_info;
 547	struct rb_node *node;
 548	bool pending;
 549
 550	/* This is paired with btrfs_add_ordered_extent. */
 551	spin_lock(&btrfs_inode->lock);
 552	btrfs_mod_outstanding_extents(btrfs_inode, -1);
 553	spin_unlock(&btrfs_inode->lock);
 554	if (root != fs_info->tree_root)
 555		btrfs_delalloc_release_metadata(btrfs_inode, entry->num_bytes,
 556						false);
 557
 558	percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
 559				 fs_info->delalloc_batch);
 560
 561	tree = &btrfs_inode->ordered_tree;
 562	spin_lock_irq(&tree->lock);
 563	node = &entry->rb_node;
 564	rb_erase(node, &tree->tree);
 565	RB_CLEAR_NODE(node);
 566	if (tree->last == node)
 567		tree->last = NULL;
 568	set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 569	pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
 
 570	spin_unlock_irq(&tree->lock);
 571
 572	/*
 573	 * The current running transaction is waiting on us, we need to let it
 574	 * know that we're complete and wake it up.
 575	 */
 576	if (pending) {
 577		struct btrfs_transaction *trans;
 578
 579		/*
 580		 * The checks for trans are just a formality, it should be set,
 581		 * but if it isn't we don't want to deref/assert under the spin
 582		 * lock, so be nice and check if trans is set, but ASSERT() so
 583		 * if it isn't set a developer will notice.
 584		 */
 585		spin_lock(&fs_info->trans_lock);
 586		trans = fs_info->running_transaction;
 587		if (trans)
 588			refcount_inc(&trans->use_count);
 589		spin_unlock(&fs_info->trans_lock);
 590
 591		ASSERT(trans);
 592		if (trans) {
 593			if (atomic_dec_and_test(&trans->pending_ordered))
 594				wake_up(&trans->pending_wait);
 595			btrfs_put_transaction(trans);
 596		}
 597	}
 598
 599	spin_lock(&root->ordered_extent_lock);
 600	list_del_init(&entry->root_extent_list);
 601	root->nr_ordered_extents--;
 602
 603	trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
 604
 605	if (!root->nr_ordered_extents) {
 606		spin_lock(&fs_info->ordered_root_lock);
 607		BUG_ON(list_empty(&root->ordered_root));
 608		list_del_init(&root->ordered_root);
 609		spin_unlock(&fs_info->ordered_root_lock);
 610	}
 611	spin_unlock(&root->ordered_extent_lock);
 612	wake_up(&entry->wait);
 613}
 614
 615static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 616{
 617	struct btrfs_ordered_extent *ordered;
 618
 619	ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 620	btrfs_start_ordered_extent(ordered, 1);
 621	complete(&ordered->completion);
 622}
 623
 624/*
 625 * wait for all the ordered extents in a root.  This is done when balancing
 626 * space between drives.
 627 */
 628u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 629			       const u64 range_start, const u64 range_len)
 630{
 631	struct btrfs_fs_info *fs_info = root->fs_info;
 632	LIST_HEAD(splice);
 633	LIST_HEAD(skipped);
 634	LIST_HEAD(works);
 635	struct btrfs_ordered_extent *ordered, *next;
 636	u64 count = 0;
 637	const u64 range_end = range_start + range_len;
 638
 639	mutex_lock(&root->ordered_extent_mutex);
 640	spin_lock(&root->ordered_extent_lock);
 641	list_splice_init(&root->ordered_extents, &splice);
 642	while (!list_empty(&splice) && nr) {
 643		ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 644					   root_extent_list);
 645
 646		if (range_end <= ordered->disk_bytenr ||
 647		    ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
 648			list_move_tail(&ordered->root_extent_list, &skipped);
 649			cond_resched_lock(&root->ordered_extent_lock);
 650			continue;
 651		}
 652
 653		list_move_tail(&ordered->root_extent_list,
 654			       &root->ordered_extents);
 655		refcount_inc(&ordered->refs);
 656		spin_unlock(&root->ordered_extent_lock);
 657
 658		btrfs_init_work(&ordered->flush_work,
 
 659				btrfs_run_ordered_extent_work, NULL, NULL);
 660		list_add_tail(&ordered->work_list, &works);
 661		btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 662
 663		cond_resched();
 664		spin_lock(&root->ordered_extent_lock);
 665		if (nr != U64_MAX)
 666			nr--;
 667		count++;
 668	}
 669	list_splice_tail(&skipped, &root->ordered_extents);
 670	list_splice_tail(&splice, &root->ordered_extents);
 671	spin_unlock(&root->ordered_extent_lock);
 672
 673	list_for_each_entry_safe(ordered, next, &works, work_list) {
 674		list_del_init(&ordered->work_list);
 675		wait_for_completion(&ordered->completion);
 676		btrfs_put_ordered_extent(ordered);
 677		cond_resched();
 678	}
 679	mutex_unlock(&root->ordered_extent_mutex);
 680
 681	return count;
 682}
 683
 684void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 685			     const u64 range_start, const u64 range_len)
 686{
 687	struct btrfs_root *root;
 688	struct list_head splice;
 
 689	u64 done;
 690
 691	INIT_LIST_HEAD(&splice);
 692
 693	mutex_lock(&fs_info->ordered_operations_mutex);
 694	spin_lock(&fs_info->ordered_root_lock);
 695	list_splice_init(&fs_info->ordered_roots, &splice);
 696	while (!list_empty(&splice) && nr) {
 697		root = list_first_entry(&splice, struct btrfs_root,
 698					ordered_root);
 699		root = btrfs_grab_root(root);
 700		BUG_ON(!root);
 701		list_move_tail(&root->ordered_root,
 702			       &fs_info->ordered_roots);
 703		spin_unlock(&fs_info->ordered_root_lock);
 704
 705		done = btrfs_wait_ordered_extents(root, nr,
 706						  range_start, range_len);
 707		btrfs_put_root(root);
 
 708
 709		spin_lock(&fs_info->ordered_root_lock);
 710		if (nr != U64_MAX) {
 711			nr -= done;
 712		}
 713	}
 714	list_splice_tail(&splice, &fs_info->ordered_roots);
 715	spin_unlock(&fs_info->ordered_root_lock);
 716	mutex_unlock(&fs_info->ordered_operations_mutex);
 
 
 717}
 718
 719/*
 720 * Used to start IO or wait for a given ordered extent to finish.
 721 *
 722 * If wait is one, this effectively waits on page writeback for all the pages
 723 * in the extent, and it waits on the io completion code to insert
 724 * metadata into the btree corresponding to the extent
 725 */
 726void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry, int wait)
 
 
 727{
 728	u64 start = entry->file_offset;
 729	u64 end = start + entry->num_bytes - 1;
 730	struct btrfs_inode *inode = BTRFS_I(entry->inode);
 731
 732	trace_btrfs_ordered_extent_start(inode, entry);
 733
 734	/*
 735	 * pages in the range can be dirty, clean or writeback.  We
 736	 * start IO on any dirty ones so the wait doesn't stall waiting
 737	 * for the flusher thread to find them
 738	 */
 739	if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 740		filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
 741	if (wait) {
 742		wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 743						 &entry->flags));
 744	}
 745}
 746
 747/*
 748 * Used to wait on ordered extents across a large range of bytes.
 749 */
 750int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 751{
 752	int ret = 0;
 753	int ret_wb = 0;
 754	u64 end;
 755	u64 orig_end;
 756	struct btrfs_ordered_extent *ordered;
 757
 758	if (start + len < start) {
 759		orig_end = INT_LIMIT(loff_t);
 760	} else {
 761		orig_end = start + len - 1;
 762		if (orig_end > INT_LIMIT(loff_t))
 763			orig_end = INT_LIMIT(loff_t);
 764	}
 765
 766	/* start IO across the range first to instantiate any delalloc
 767	 * extents
 768	 */
 769	ret = btrfs_fdatawrite_range(inode, start, orig_end);
 770	if (ret)
 771		return ret;
 772
 773	/*
 774	 * If we have a writeback error don't return immediately. Wait first
 775	 * for any ordered extents that haven't completed yet. This is to make
 776	 * sure no one can dirty the same page ranges and call writepages()
 777	 * before the ordered extents complete - to avoid failures (-EEXIST)
 778	 * when adding the new ordered extents to the ordered tree.
 779	 */
 780	ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 781
 782	end = orig_end;
 783	while (1) {
 784		ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode), end);
 785		if (!ordered)
 786			break;
 787		if (ordered->file_offset > orig_end) {
 788			btrfs_put_ordered_extent(ordered);
 789			break;
 790		}
 791		if (ordered->file_offset + ordered->num_bytes <= start) {
 792			btrfs_put_ordered_extent(ordered);
 793			break;
 794		}
 795		btrfs_start_ordered_extent(ordered, 1);
 796		end = ordered->file_offset;
 797		/*
 798		 * If the ordered extent had an error save the error but don't
 799		 * exit without waiting first for all other ordered extents in
 800		 * the range to complete.
 801		 */
 802		if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 803			ret = -EIO;
 804		btrfs_put_ordered_extent(ordered);
 805		if (end == 0 || end == start)
 806			break;
 807		end--;
 808	}
 809	return ret_wb ? ret_wb : ret;
 810}
 811
 812/*
 813 * find an ordered extent corresponding to file_offset.  return NULL if
 814 * nothing is found, otherwise take a reference on the extent and return it
 815 */
 816struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
 817							 u64 file_offset)
 818{
 819	struct btrfs_ordered_inode_tree *tree;
 820	struct rb_node *node;
 821	struct btrfs_ordered_extent *entry = NULL;
 822	unsigned long flags;
 823
 824	tree = &inode->ordered_tree;
 825	spin_lock_irqsave(&tree->lock, flags);
 826	node = tree_search(tree, file_offset);
 827	if (!node)
 828		goto out;
 829
 830	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 831	if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 832		entry = NULL;
 833	if (entry)
 834		refcount_inc(&entry->refs);
 835out:
 836	spin_unlock_irqrestore(&tree->lock, flags);
 837	return entry;
 838}
 839
 840/* Since the DIO code tries to lock a wide area we need to look for any ordered
 841 * extents that exist in the range, rather than just the start of the range.
 842 */
 843struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 844		struct btrfs_inode *inode, u64 file_offset, u64 len)
 845{
 846	struct btrfs_ordered_inode_tree *tree;
 847	struct rb_node *node;
 848	struct btrfs_ordered_extent *entry = NULL;
 849
 850	tree = &inode->ordered_tree;
 851	spin_lock_irq(&tree->lock);
 852	node = tree_search(tree, file_offset);
 853	if (!node) {
 854		node = tree_search(tree, file_offset + len);
 855		if (!node)
 856			goto out;
 857	}
 858
 859	while (1) {
 860		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 861		if (range_overlaps(entry, file_offset, len))
 862			break;
 863
 864		if (entry->file_offset >= file_offset + len) {
 865			entry = NULL;
 866			break;
 867		}
 868		entry = NULL;
 869		node = rb_next(node);
 870		if (!node)
 871			break;
 872	}
 873out:
 874	if (entry)
 875		refcount_inc(&entry->refs);
 876	spin_unlock_irq(&tree->lock);
 877	return entry;
 878}
 879
 880/*
 881 * Adds all ordered extents to the given list. The list ends up sorted by the
 882 * file_offset of the ordered extents.
 883 */
 884void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
 885					   struct list_head *list)
 886{
 887	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 888	struct rb_node *n;
 889
 890	ASSERT(inode_is_locked(&inode->vfs_inode));
 891
 892	spin_lock_irq(&tree->lock);
 893	for (n = rb_first(&tree->tree); n; n = rb_next(n)) {
 894		struct btrfs_ordered_extent *ordered;
 895
 896		ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 897
 898		if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 899			continue;
 900
 901		ASSERT(list_empty(&ordered->log_list));
 902		list_add_tail(&ordered->log_list, list);
 903		refcount_inc(&ordered->refs);
 904	}
 905	spin_unlock_irq(&tree->lock);
 906}
 907
 908/*
 909 * lookup and return any extent before 'file_offset'.  NULL is returned
 910 * if none is found
 911 */
 912struct btrfs_ordered_extent *
 913btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
 914{
 915	struct btrfs_ordered_inode_tree *tree;
 916	struct rb_node *node;
 917	struct btrfs_ordered_extent *entry = NULL;
 918
 919	tree = &inode->ordered_tree;
 920	spin_lock_irq(&tree->lock);
 921	node = tree_search(tree, file_offset);
 922	if (!node)
 923		goto out;
 924
 925	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 926	refcount_inc(&entry->refs);
 927out:
 928	spin_unlock_irq(&tree->lock);
 929	return entry;
 930}
 931
 932/*
 933 * Lookup the first ordered extent that overlaps the range
 934 * [@file_offset, @file_offset + @len).
 935 *
 936 * The difference between this and btrfs_lookup_first_ordered_extent() is
 937 * that this one won't return any ordered extent that does not overlap the range.
 938 * And the difference against btrfs_lookup_ordered_extent() is, this function
 939 * ensures the first ordered extent gets returned.
 940 */
 941struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
 942			struct btrfs_inode *inode, u64 file_offset, u64 len)
 943{
 944	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 
 
 
 945	struct rb_node *node;
 946	struct rb_node *cur;
 947	struct rb_node *prev;
 948	struct rb_node *next;
 949	struct btrfs_ordered_extent *entry = NULL;
 950
 951	spin_lock_irq(&tree->lock);
 952	node = tree->tree.rb_node;
 
 
 
 
 
 
 
 
 
 
 953	/*
 954	 * Here we don't want to use tree_search() which will use tree->last
 955	 * and screw up the search order.
 956	 * And __tree_search() can't return the adjacent ordered extents
 957	 * either, thus here we do our own search.
 
 
 
 
 
 958	 */
 959	while (node) {
 960		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 
 
 
 
 
 
 
 
 
 
 961
 962		if (file_offset < entry->file_offset) {
 963			node = node->rb_left;
 964		} else if (file_offset >= entry_end(entry)) {
 965			node = node->rb_right;
 966		} else {
 967			/*
 968			 * Direct hit, got an ordered extent that starts at
 969			 * @file_offset
 970			 */
 971			goto out;
 972		}
 973	}
 974	if (!entry) {
 975		/* Empty tree */
 976		goto out;
 977	}
 978
 979	cur = &entry->rb_node;
 980	/* We got an entry around @file_offset, check adjacent entries */
 981	if (entry->file_offset < file_offset) {
 982		prev = cur;
 983		next = rb_next(cur);
 
 
 984	} else {
 985		prev = rb_prev(cur);
 986		next = cur;
 
 
 
 
 
 
 
 
 
 987	}
 988	if (prev) {
 989		entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
 990		if (range_overlaps(entry, file_offset, len))
 991			goto out;
 992	}
 993	if (next) {
 994		entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
 995		if (range_overlaps(entry, file_offset, len))
 996			goto out;
 997	}
 998	/* No ordered extent in the range */
 999	entry = NULL;
1000out:
1001	if (entry)
1002		refcount_inc(&entry->refs);
1003	spin_unlock_irq(&tree->lock);
1004	return entry;
1005}
1006
1007/*
1008 * btrfs_flush_ordered_range - Lock the passed range and ensures all pending
1009 * ordered extents in it are run to completion.
1010 *
1011 * @inode:        Inode whose ordered tree is to be searched
1012 * @start:        Beginning of range to flush
1013 * @end:          Last byte of range to lock
1014 * @cached_state: If passed, will return the extent state responsible for the
1015 * locked range. It's the caller's responsibility to free the cached state.
1016 *
1017 * This function always returns with the given range locked, ensuring after it's
1018 * called no order extent can be pending.
1019 */
1020void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
1021					u64 end,
1022					struct extent_state **cached_state)
1023{
1024	struct btrfs_ordered_extent *ordered;
1025	struct extent_state *cache = NULL;
1026	struct extent_state **cachedp = &cache;
1027
1028	if (cached_state)
1029		cachedp = cached_state;
 
 
1030
1031	while (1) {
1032		lock_extent_bits(&inode->io_tree, start, end, cachedp);
1033		ordered = btrfs_lookup_ordered_range(inode, start,
1034						     end - start + 1);
1035		if (!ordered) {
1036			/*
1037			 * If no external cached_state has been passed then
1038			 * decrement the extra ref taken for cachedp since we
1039			 * aren't exposing it outside of this function
1040			 */
1041			if (!cached_state)
1042				refcount_dec(&cache->refs);
1043			break;
1044		}
1045		unlock_extent_cached(&inode->io_tree, start, end, cachedp);
1046		btrfs_start_ordered_extent(ordered, 1);
1047		btrfs_put_ordered_extent(ordered);
1048	}
1049}
1050
1051static int clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
1052				u64 len)
1053{
1054	struct inode *inode = ordered->inode;
1055	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1056	u64 file_offset = ordered->file_offset + pos;
1057	u64 disk_bytenr = ordered->disk_bytenr + pos;
1058	u64 num_bytes = len;
1059	u64 disk_num_bytes = len;
1060	int type;
1061	unsigned long flags_masked = ordered->flags & ~(1 << BTRFS_ORDERED_DIRECT);
1062	int compress_type = ordered->compress_type;
1063	unsigned long weight;
1064	int ret;
1065
1066	weight = hweight_long(flags_masked);
1067	WARN_ON_ONCE(weight > 1);
1068	if (!weight)
1069		type = 0;
1070	else
1071		type = __ffs(flags_masked);
1072
1073	/*
1074	 * The splitting extent is already counted and will be added again
1075	 * in btrfs_add_ordered_extent_*(). Subtract num_bytes to avoid
1076	 * double counting.
 
 
 
 
 
 
 
 
 
 
 
1077	 */
1078	percpu_counter_add_batch(&fs_info->ordered_bytes, -num_bytes,
1079				 fs_info->delalloc_batch);
1080	if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered->flags)) {
1081		WARN_ON_ONCE(1);
1082		ret = btrfs_add_ordered_extent_compress(BTRFS_I(inode),
1083				file_offset, disk_bytenr, num_bytes,
1084				disk_num_bytes, compress_type);
1085	} else if (test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
1086		ret = btrfs_add_ordered_extent_dio(BTRFS_I(inode), file_offset,
1087				disk_bytenr, num_bytes, disk_num_bytes, type);
1088	} else {
1089		ret = btrfs_add_ordered_extent(BTRFS_I(inode), file_offset,
1090				disk_bytenr, num_bytes, disk_num_bytes, type);
1091	}
1092
1093	return ret;
1094}
1095
1096int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pre,
1097				u64 post)
 
 
 
 
 
1098{
1099	struct inode *inode = ordered->inode;
 
1100	struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1101	struct rb_node *node;
1102	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1103	int ret = 0;
 
 
 
 
 
1104
1105	spin_lock_irq(&tree->lock);
1106	/* Remove from tree once */
1107	node = &ordered->rb_node;
1108	rb_erase(node, &tree->tree);
1109	RB_CLEAR_NODE(node);
1110	if (tree->last == node)
1111		tree->last = NULL;
1112
1113	ordered->file_offset += pre;
1114	ordered->disk_bytenr += pre;
1115	ordered->num_bytes -= (pre + post);
1116	ordered->disk_num_bytes -= (pre + post);
1117	ordered->bytes_left -= (pre + post);
1118
1119	/* Re-insert the node */
1120	node = tree_insert(&tree->tree, ordered->file_offset, &ordered->rb_node);
1121	if (node)
1122		btrfs_panic(fs_info, -EEXIST,
1123			"zoned: inconsistency in ordered tree at offset %llu",
1124			    ordered->file_offset);
1125
1126	spin_unlock_irq(&tree->lock);
1127
1128	if (pre)
1129		ret = clone_ordered_extent(ordered, 0, pre);
1130	if (ret == 0 && post)
1131		ret = clone_ordered_extent(ordered, pre + ordered->disk_num_bytes,
1132					   post);
1133
1134	return ret;
1135}
1136
1137int __init ordered_data_init(void)
1138{
1139	btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1140				     sizeof(struct btrfs_ordered_extent), 0,
1141				     SLAB_MEM_SPREAD,
1142				     NULL);
1143	if (!btrfs_ordered_extent_cache)
1144		return -ENOMEM;
1145
1146	return 0;
1147}
1148
1149void __cold ordered_data_exit(void)
1150{
1151	kmem_cache_destroy(btrfs_ordered_extent_cache);
1152}