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v6.8
   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 "messages.h"
  11#include "misc.h"
  12#include "ctree.h"
  13#include "transaction.h"
  14#include "btrfs_inode.h"
  15#include "extent_io.h"
  16#include "disk-io.h"
  17#include "compression.h"
  18#include "delalloc-space.h"
  19#include "qgroup.h"
  20#include "subpage.h"
  21#include "file.h"
  22#include "super.h"
  23
  24static struct kmem_cache *btrfs_ordered_extent_cache;
  25
  26static u64 entry_end(struct btrfs_ordered_extent *entry)
  27{
  28	if (entry->file_offset + entry->num_bytes < entry->file_offset)
  29		return (u64)-1;
  30	return entry->file_offset + entry->num_bytes;
  31}
  32
  33/* returns NULL if the insertion worked, or it returns the node it did find
  34 * in the tree
  35 */
  36static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
  37				   struct rb_node *node)
  38{
  39	struct rb_node **p = &root->rb_node;
  40	struct rb_node *parent = NULL;
  41	struct btrfs_ordered_extent *entry;
  42
  43	while (*p) {
  44		parent = *p;
  45		entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
  46
  47		if (file_offset < entry->file_offset)
  48			p = &(*p)->rb_left;
  49		else if (file_offset >= entry_end(entry))
  50			p = &(*p)->rb_right;
  51		else
  52			return parent;
  53	}
  54
  55	rb_link_node(node, parent, p);
  56	rb_insert_color(node, root);
  57	return NULL;
  58}
  59
  60/*
  61 * look for a given offset in the tree, and if it can't be found return the
  62 * first lesser offset
  63 */
  64static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
  65				     struct rb_node **prev_ret)
  66{
  67	struct rb_node *n = root->rb_node;
  68	struct rb_node *prev = NULL;
  69	struct rb_node *test;
  70	struct btrfs_ordered_extent *entry;
  71	struct btrfs_ordered_extent *prev_entry = NULL;
  72
  73	while (n) {
  74		entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
  75		prev = n;
  76		prev_entry = entry;
  77
  78		if (file_offset < entry->file_offset)
  79			n = n->rb_left;
  80		else if (file_offset >= entry_end(entry))
  81			n = n->rb_right;
  82		else
  83			return n;
  84	}
  85	if (!prev_ret)
  86		return NULL;
  87
  88	while (prev && file_offset >= entry_end(prev_entry)) {
  89		test = rb_next(prev);
  90		if (!test)
  91			break;
  92		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
  93				      rb_node);
  94		if (file_offset < entry_end(prev_entry))
  95			break;
  96
  97		prev = test;
  98	}
  99	if (prev)
 100		prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
 101				      rb_node);
 102	while (prev && file_offset < entry_end(prev_entry)) {
 103		test = rb_prev(prev);
 104		if (!test)
 105			break;
 106		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 107				      rb_node);
 108		prev = test;
 109	}
 110	*prev_ret = prev;
 111	return NULL;
 112}
 113
 114static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
 115			  u64 len)
 116{
 117	if (file_offset + len <= entry->file_offset ||
 118	    entry->file_offset + entry->num_bytes <= file_offset)
 119		return 0;
 120	return 1;
 121}
 122
 123/*
 124 * look find the first ordered struct that has this offset, otherwise
 125 * the first one less than this offset
 126 */
 127static inline struct rb_node *ordered_tree_search(struct btrfs_inode *inode,
 128						  u64 file_offset)
 129{
 130	struct rb_node *prev = NULL;
 131	struct rb_node *ret;
 132	struct btrfs_ordered_extent *entry;
 133
 134	if (inode->ordered_tree_last) {
 135		entry = rb_entry(inode->ordered_tree_last, struct btrfs_ordered_extent,
 136				 rb_node);
 137		if (in_range(file_offset, entry->file_offset, entry->num_bytes))
 138			return inode->ordered_tree_last;
 139	}
 140	ret = __tree_search(&inode->ordered_tree, file_offset, &prev);
 141	if (!ret)
 142		ret = prev;
 143	if (ret)
 144		inode->ordered_tree_last = ret;
 145	return ret;
 146}
 147
 148static struct btrfs_ordered_extent *alloc_ordered_extent(
 149			struct btrfs_inode *inode, u64 file_offset, u64 num_bytes,
 150			u64 ram_bytes, u64 disk_bytenr, u64 disk_num_bytes,
 151			u64 offset, unsigned long flags, int compress_type)
 152{
 153	struct btrfs_ordered_extent *entry;
 154	int ret;
 155	u64 qgroup_rsv = 0;
 156
 157	if (flags &
 158	    ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
 159		/* For nocow write, we can release the qgroup rsv right now */
 160		ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes, &qgroup_rsv);
 161		if (ret < 0)
 162			return ERR_PTR(ret);
 163	} else {
 164		/*
 165		 * The ordered extent has reserved qgroup space, release now
 166		 * and pass the reserved number for qgroup_record to free.
 167		 */
 168		ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes, &qgroup_rsv);
 169		if (ret < 0)
 170			return ERR_PTR(ret);
 171	}
 172	entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 173	if (!entry)
 174		return ERR_PTR(-ENOMEM);
 175
 176	entry->file_offset = file_offset;
 177	entry->num_bytes = num_bytes;
 178	entry->ram_bytes = ram_bytes;
 179	entry->disk_bytenr = disk_bytenr;
 180	entry->disk_num_bytes = disk_num_bytes;
 181	entry->offset = offset;
 182	entry->bytes_left = num_bytes;
 183	entry->inode = igrab(&inode->vfs_inode);
 184	entry->compress_type = compress_type;
 185	entry->truncated_len = (u64)-1;
 186	entry->qgroup_rsv = qgroup_rsv;
 187	entry->flags = flags;
 188	refcount_set(&entry->refs, 1);
 189	init_waitqueue_head(&entry->wait);
 190	INIT_LIST_HEAD(&entry->list);
 191	INIT_LIST_HEAD(&entry->log_list);
 192	INIT_LIST_HEAD(&entry->root_extent_list);
 193	INIT_LIST_HEAD(&entry->work_list);
 194	INIT_LIST_HEAD(&entry->bioc_list);
 195	init_completion(&entry->completion);
 196
 197	/*
 198	 * We don't need the count_max_extents here, we can assume that all of
 199	 * that work has been done at higher layers, so this is truly the
 200	 * smallest the extent is going to get.
 201	 */
 202	spin_lock(&inode->lock);
 203	btrfs_mod_outstanding_extents(inode, 1);
 204	spin_unlock(&inode->lock);
 205
 206	return entry;
 207}
 208
 209static void insert_ordered_extent(struct btrfs_ordered_extent *entry)
 210{
 211	struct btrfs_inode *inode = BTRFS_I(entry->inode);
 212	struct btrfs_root *root = inode->root;
 213	struct btrfs_fs_info *fs_info = root->fs_info;
 214	struct rb_node *node;
 215
 216	trace_btrfs_ordered_extent_add(inode, entry);
 217
 218	percpu_counter_add_batch(&fs_info->ordered_bytes, entry->num_bytes,
 219				 fs_info->delalloc_batch);
 220
 221	/* One ref for the tree. */
 222	refcount_inc(&entry->refs);
 223
 224	spin_lock_irq(&inode->ordered_tree_lock);
 225	node = tree_insert(&inode->ordered_tree, entry->file_offset,
 226			   &entry->rb_node);
 227	if (node)
 228		btrfs_panic(fs_info, -EEXIST,
 229				"inconsistency in ordered tree at offset %llu",
 230				entry->file_offset);
 231	spin_unlock_irq(&inode->ordered_tree_lock);
 232
 233	spin_lock(&root->ordered_extent_lock);
 234	list_add_tail(&entry->root_extent_list,
 235		      &root->ordered_extents);
 236	root->nr_ordered_extents++;
 237	if (root->nr_ordered_extents == 1) {
 238		spin_lock(&fs_info->ordered_root_lock);
 239		BUG_ON(!list_empty(&root->ordered_root));
 240		list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 241		spin_unlock(&fs_info->ordered_root_lock);
 242	}
 243	spin_unlock(&root->ordered_extent_lock);
 244}
 245
 246/*
 247 * Add an ordered extent to the per-inode tree.
 248 *
 249 * @inode:           Inode that this extent is for.
 250 * @file_offset:     Logical offset in file where the extent starts.
 251 * @num_bytes:       Logical length of extent in file.
 252 * @ram_bytes:       Full length of unencoded data.
 253 * @disk_bytenr:     Offset of extent on disk.
 254 * @disk_num_bytes:  Size of extent on disk.
 255 * @offset:          Offset into unencoded data where file data starts.
 256 * @flags:           Flags specifying type of extent (1 << BTRFS_ORDERED_*).
 257 * @compress_type:   Compression algorithm used for data.
 258 *
 259 * Most of these parameters correspond to &struct btrfs_file_extent_item. The
 260 * tree is given a single reference on the ordered extent that was inserted, and
 261 * the returned pointer is given a second reference.
 262 *
 263 * Return: the new ordered extent or error pointer.
 264 */
 265struct btrfs_ordered_extent *btrfs_alloc_ordered_extent(
 266			struct btrfs_inode *inode, u64 file_offset,
 267			u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
 268			u64 disk_num_bytes, u64 offset, unsigned long flags,
 269			int compress_type)
 270{
 271	struct btrfs_ordered_extent *entry;
 272
 273	ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
 274
 275	entry = alloc_ordered_extent(inode, file_offset, num_bytes, ram_bytes,
 276				     disk_bytenr, disk_num_bytes, offset, flags,
 277				     compress_type);
 278	if (!IS_ERR(entry))
 279		insert_ordered_extent(entry);
 280	return entry;
 281}
 282
 283/*
 284 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 285 * when an ordered extent is finished.  If the list covers more than one
 286 * ordered extent, it is split across multiples.
 287 */
 288void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 289			   struct btrfs_ordered_sum *sum)
 290{
 291	struct btrfs_inode *inode = BTRFS_I(entry->inode);
 292
 293	spin_lock_irq(&inode->ordered_tree_lock);
 294	list_add_tail(&sum->list, &entry->list);
 295	spin_unlock_irq(&inode->ordered_tree_lock);
 296}
 297
 298static void finish_ordered_fn(struct btrfs_work *work)
 299{
 300	struct btrfs_ordered_extent *ordered_extent;
 301
 302	ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
 303	btrfs_finish_ordered_io(ordered_extent);
 304}
 305
 306static bool can_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
 307				      struct page *page, u64 file_offset,
 308				      u64 len, bool uptodate)
 309{
 310	struct btrfs_inode *inode = BTRFS_I(ordered->inode);
 311	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 312
 313	lockdep_assert_held(&inode->ordered_tree_lock);
 314
 315	if (page) {
 316		ASSERT(page->mapping);
 317		ASSERT(page_offset(page) <= file_offset);
 318		ASSERT(file_offset + len <= page_offset(page) + PAGE_SIZE);
 319
 320		/*
 321		 * Ordered (Private2) bit indicates whether we still have
 322		 * pending io unfinished for the ordered extent.
 323		 *
 324		 * If there's no such bit, we need to skip to next range.
 325		 */
 326		if (!btrfs_folio_test_ordered(fs_info, page_folio(page),
 327					      file_offset, len))
 328			return false;
 329		btrfs_folio_clear_ordered(fs_info, page_folio(page), file_offset, len);
 330	}
 331
 332	/* Now we're fine to update the accounting. */
 333	if (WARN_ON_ONCE(len > ordered->bytes_left)) {
 334		btrfs_crit(fs_info,
 335"bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%llu left=%llu",
 336			   inode->root->root_key.objectid, btrfs_ino(inode),
 337			   ordered->file_offset, ordered->num_bytes,
 338			   len, ordered->bytes_left);
 339		ordered->bytes_left = 0;
 340	} else {
 341		ordered->bytes_left -= len;
 342	}
 343
 344	if (!uptodate)
 345		set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
 346
 347	if (ordered->bytes_left)
 348		return false;
 349
 350	/*
 351	 * All the IO of the ordered extent is finished, we need to queue
 352	 * the finish_func to be executed.
 353	 */
 354	set_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags);
 355	cond_wake_up(&ordered->wait);
 356	refcount_inc(&ordered->refs);
 357	trace_btrfs_ordered_extent_mark_finished(inode, ordered);
 358	return true;
 359}
 360
 361static void btrfs_queue_ordered_fn(struct btrfs_ordered_extent *ordered)
 362{
 363	struct btrfs_inode *inode = BTRFS_I(ordered->inode);
 364	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 365	struct btrfs_workqueue *wq = btrfs_is_free_space_inode(inode) ?
 366		fs_info->endio_freespace_worker : fs_info->endio_write_workers;
 367
 368	btrfs_init_work(&ordered->work, finish_ordered_fn, NULL);
 369	btrfs_queue_work(wq, &ordered->work);
 370}
 371
 372bool btrfs_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
 373				 struct page *page, u64 file_offset, u64 len,
 374				 bool uptodate)
 375{
 376	struct btrfs_inode *inode = BTRFS_I(ordered->inode);
 377	unsigned long flags;
 378	bool ret;
 379
 380	trace_btrfs_finish_ordered_extent(inode, file_offset, len, uptodate);
 381
 382	spin_lock_irqsave(&inode->ordered_tree_lock, flags);
 383	ret = can_finish_ordered_extent(ordered, page, file_offset, len, uptodate);
 384	spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
 385
 386	if (ret)
 387		btrfs_queue_ordered_fn(ordered);
 388	return ret;
 389}
 390
 391/*
 392 * Mark all ordered extents io inside the specified range finished.
 393 *
 394 * @page:	 The involved page for the operation.
 395 *		 For uncompressed buffered IO, the page status also needs to be
 396 *		 updated to indicate whether the pending ordered io is finished.
 397 *		 Can be NULL for direct IO and compressed write.
 398 *		 For these cases, callers are ensured they won't execute the
 399 *		 endio function twice.
 400 *
 401 * This function is called for endio, thus the range must have ordered
 402 * extent(s) covering it.
 403 */
 404void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
 405				    struct page *page, u64 file_offset,
 406				    u64 num_bytes, bool uptodate)
 407{
 408	struct rb_node *node;
 409	struct btrfs_ordered_extent *entry = NULL;
 410	unsigned long flags;
 411	u64 cur = file_offset;
 412
 413	trace_btrfs_writepage_end_io_hook(inode, file_offset,
 414					  file_offset + num_bytes - 1,
 415					  uptodate);
 416
 417	spin_lock_irqsave(&inode->ordered_tree_lock, flags);
 418	while (cur < file_offset + num_bytes) {
 419		u64 entry_end;
 420		u64 end;
 421		u32 len;
 422
 423		node = ordered_tree_search(inode, cur);
 424		/* No ordered extents at all */
 425		if (!node)
 426			break;
 427
 428		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 429		entry_end = entry->file_offset + entry->num_bytes;
 430		/*
 431		 * |<-- OE --->|  |
 432		 *		  cur
 433		 * Go to next OE.
 434		 */
 435		if (cur >= entry_end) {
 436			node = rb_next(node);
 437			/* No more ordered extents, exit */
 438			if (!node)
 439				break;
 440			entry = rb_entry(node, struct btrfs_ordered_extent,
 441					 rb_node);
 442
 443			/* Go to next ordered extent and continue */
 444			cur = entry->file_offset;
 445			continue;
 446		}
 447		/*
 448		 * |	|<--- OE --->|
 449		 * cur
 450		 * Go to the start of OE.
 451		 */
 452		if (cur < entry->file_offset) {
 453			cur = entry->file_offset;
 454			continue;
 455		}
 456
 457		/*
 458		 * Now we are definitely inside one ordered extent.
 459		 *
 460		 * |<--- OE --->|
 461		 *	|
 462		 *	cur
 463		 */
 464		end = min(entry->file_offset + entry->num_bytes,
 465			  file_offset + num_bytes) - 1;
 466		ASSERT(end + 1 - cur < U32_MAX);
 467		len = end + 1 - cur;
 468
 469		if (can_finish_ordered_extent(entry, page, cur, len, uptodate)) {
 470			spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
 471			btrfs_queue_ordered_fn(entry);
 472			spin_lock_irqsave(&inode->ordered_tree_lock, flags);
 473		}
 474		cur += len;
 475	}
 476	spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
 477}
 478
 479/*
 480 * Finish IO for one ordered extent across a given range.  The range can only
 481 * contain one ordered extent.
 482 *
 483 * @cached:	 The cached ordered extent. If not NULL, we can skip the tree
 484 *               search and use the ordered extent directly.
 485 * 		 Will be also used to store the finished ordered extent.
 486 * @file_offset: File offset for the finished IO
 487 * @io_size:	 Length of the finish IO range
 488 *
 489 * Return true if the ordered extent is finished in the range, and update
 490 * @cached.
 491 * Return false otherwise.
 492 *
 493 * NOTE: The range can NOT cross multiple ordered extents.
 494 * Thus caller should ensure the range doesn't cross ordered extents.
 495 */
 496bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 497				    struct btrfs_ordered_extent **cached,
 498				    u64 file_offset, u64 io_size)
 499{
 500	struct rb_node *node;
 501	struct btrfs_ordered_extent *entry = NULL;
 502	unsigned long flags;
 503	bool finished = false;
 504
 505	spin_lock_irqsave(&inode->ordered_tree_lock, flags);
 506	if (cached && *cached) {
 507		entry = *cached;
 508		goto have_entry;
 509	}
 510
 511	node = ordered_tree_search(inode, file_offset);
 512	if (!node)
 513		goto out;
 514
 515	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 516have_entry:
 517	if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 518		goto out;
 519
 520	if (io_size > entry->bytes_left)
 521		btrfs_crit(inode->root->fs_info,
 522			   "bad ordered accounting left %llu size %llu",
 523		       entry->bytes_left, io_size);
 524
 525	entry->bytes_left -= io_size;
 526
 527	if (entry->bytes_left == 0) {
 528		/*
 529		 * Ensure only one caller can set the flag and finished_ret
 530		 * accordingly
 531		 */
 532		finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 533		/* test_and_set_bit implies a barrier */
 534		cond_wake_up_nomb(&entry->wait);
 535	}
 536out:
 537	if (finished && cached && entry) {
 538		*cached = entry;
 539		refcount_inc(&entry->refs);
 540		trace_btrfs_ordered_extent_dec_test_pending(inode, entry);
 541	}
 542	spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
 543	return finished;
 544}
 545
 546/*
 547 * used to drop a reference on an ordered extent.  This will free
 548 * the extent if the last reference is dropped
 549 */
 550void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 551{
 552	struct list_head *cur;
 553	struct btrfs_ordered_sum *sum;
 554
 555	trace_btrfs_ordered_extent_put(BTRFS_I(entry->inode), entry);
 556
 557	if (refcount_dec_and_test(&entry->refs)) {
 558		ASSERT(list_empty(&entry->root_extent_list));
 559		ASSERT(list_empty(&entry->log_list));
 560		ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 561		if (entry->inode)
 562			btrfs_add_delayed_iput(BTRFS_I(entry->inode));
 563		while (!list_empty(&entry->list)) {
 564			cur = entry->list.next;
 565			sum = list_entry(cur, struct btrfs_ordered_sum, list);
 566			list_del(&sum->list);
 567			kvfree(sum);
 568		}
 569		kmem_cache_free(btrfs_ordered_extent_cache, entry);
 570	}
 571}
 572
 573/*
 574 * remove an ordered extent from the tree.  No references are dropped
 575 * and waiters are woken up.
 576 */
 577void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
 578				 struct btrfs_ordered_extent *entry)
 579{
 580	struct btrfs_root *root = btrfs_inode->root;
 581	struct btrfs_fs_info *fs_info = root->fs_info;
 582	struct rb_node *node;
 583	bool pending;
 584	bool freespace_inode;
 585
 586	/*
 587	 * If this is a free space inode the thread has not acquired the ordered
 588	 * extents lockdep map.
 589	 */
 590	freespace_inode = btrfs_is_free_space_inode(btrfs_inode);
 591
 592	btrfs_lockdep_acquire(fs_info, btrfs_trans_pending_ordered);
 593	/* This is paired with btrfs_alloc_ordered_extent. */
 594	spin_lock(&btrfs_inode->lock);
 595	btrfs_mod_outstanding_extents(btrfs_inode, -1);
 596	spin_unlock(&btrfs_inode->lock);
 597	if (root != fs_info->tree_root) {
 598		u64 release;
 599
 600		if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
 601			release = entry->disk_num_bytes;
 602		else
 603			release = entry->num_bytes;
 604		btrfs_delalloc_release_metadata(btrfs_inode, release,
 605						test_bit(BTRFS_ORDERED_IOERR,
 606							 &entry->flags));
 607	}
 608
 609	percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
 610				 fs_info->delalloc_batch);
 611
 612	spin_lock_irq(&btrfs_inode->ordered_tree_lock);
 613	node = &entry->rb_node;
 614	rb_erase(node, &btrfs_inode->ordered_tree);
 615	RB_CLEAR_NODE(node);
 616	if (btrfs_inode->ordered_tree_last == node)
 617		btrfs_inode->ordered_tree_last = NULL;
 618	set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 619	pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
 620	spin_unlock_irq(&btrfs_inode->ordered_tree_lock);
 621
 622	/*
 623	 * The current running transaction is waiting on us, we need to let it
 624	 * know that we're complete and wake it up.
 625	 */
 626	if (pending) {
 627		struct btrfs_transaction *trans;
 628
 629		/*
 630		 * The checks for trans are just a formality, it should be set,
 631		 * but if it isn't we don't want to deref/assert under the spin
 632		 * lock, so be nice and check if trans is set, but ASSERT() so
 633		 * if it isn't set a developer will notice.
 634		 */
 635		spin_lock(&fs_info->trans_lock);
 636		trans = fs_info->running_transaction;
 637		if (trans)
 638			refcount_inc(&trans->use_count);
 639		spin_unlock(&fs_info->trans_lock);
 640
 641		ASSERT(trans || BTRFS_FS_ERROR(fs_info));
 642		if (trans) {
 643			if (atomic_dec_and_test(&trans->pending_ordered))
 644				wake_up(&trans->pending_wait);
 645			btrfs_put_transaction(trans);
 646		}
 647	}
 648
 649	btrfs_lockdep_release(fs_info, btrfs_trans_pending_ordered);
 650
 651	spin_lock(&root->ordered_extent_lock);
 652	list_del_init(&entry->root_extent_list);
 653	root->nr_ordered_extents--;
 654
 655	trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
 656
 657	if (!root->nr_ordered_extents) {
 658		spin_lock(&fs_info->ordered_root_lock);
 659		BUG_ON(list_empty(&root->ordered_root));
 660		list_del_init(&root->ordered_root);
 661		spin_unlock(&fs_info->ordered_root_lock);
 662	}
 663	spin_unlock(&root->ordered_extent_lock);
 664	wake_up(&entry->wait);
 665	if (!freespace_inode)
 666		btrfs_lockdep_release(fs_info, btrfs_ordered_extent);
 667}
 668
 669static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 670{
 671	struct btrfs_ordered_extent *ordered;
 672
 673	ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 674	btrfs_start_ordered_extent(ordered);
 675	complete(&ordered->completion);
 676}
 677
 678/*
 679 * wait for all the ordered extents in a root.  This is done when balancing
 680 * space between drives.
 681 */
 682u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 683			       const u64 range_start, const u64 range_len)
 684{
 685	struct btrfs_fs_info *fs_info = root->fs_info;
 686	LIST_HEAD(splice);
 687	LIST_HEAD(skipped);
 688	LIST_HEAD(works);
 689	struct btrfs_ordered_extent *ordered, *next;
 690	u64 count = 0;
 691	const u64 range_end = range_start + range_len;
 692
 693	mutex_lock(&root->ordered_extent_mutex);
 694	spin_lock(&root->ordered_extent_lock);
 695	list_splice_init(&root->ordered_extents, &splice);
 696	while (!list_empty(&splice) && nr) {
 697		ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 698					   root_extent_list);
 699
 700		if (range_end <= ordered->disk_bytenr ||
 701		    ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
 702			list_move_tail(&ordered->root_extent_list, &skipped);
 703			cond_resched_lock(&root->ordered_extent_lock);
 704			continue;
 705		}
 706
 707		list_move_tail(&ordered->root_extent_list,
 708			       &root->ordered_extents);
 709		refcount_inc(&ordered->refs);
 710		spin_unlock(&root->ordered_extent_lock);
 711
 712		btrfs_init_work(&ordered->flush_work,
 713				btrfs_run_ordered_extent_work, NULL);
 714		list_add_tail(&ordered->work_list, &works);
 715		btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 716
 717		cond_resched();
 718		spin_lock(&root->ordered_extent_lock);
 719		if (nr != U64_MAX)
 720			nr--;
 721		count++;
 722	}
 723	list_splice_tail(&skipped, &root->ordered_extents);
 724	list_splice_tail(&splice, &root->ordered_extents);
 725	spin_unlock(&root->ordered_extent_lock);
 726
 727	list_for_each_entry_safe(ordered, next, &works, work_list) {
 728		list_del_init(&ordered->work_list);
 729		wait_for_completion(&ordered->completion);
 730		btrfs_put_ordered_extent(ordered);
 731		cond_resched();
 732	}
 733	mutex_unlock(&root->ordered_extent_mutex);
 734
 735	return count;
 736}
 737
 738void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 739			     const u64 range_start, const u64 range_len)
 740{
 741	struct btrfs_root *root;
 742	LIST_HEAD(splice);
 743	u64 done;
 744
 745	mutex_lock(&fs_info->ordered_operations_mutex);
 746	spin_lock(&fs_info->ordered_root_lock);
 747	list_splice_init(&fs_info->ordered_roots, &splice);
 748	while (!list_empty(&splice) && nr) {
 749		root = list_first_entry(&splice, struct btrfs_root,
 750					ordered_root);
 751		root = btrfs_grab_root(root);
 752		BUG_ON(!root);
 753		list_move_tail(&root->ordered_root,
 754			       &fs_info->ordered_roots);
 755		spin_unlock(&fs_info->ordered_root_lock);
 756
 757		done = btrfs_wait_ordered_extents(root, nr,
 758						  range_start, range_len);
 759		btrfs_put_root(root);
 760
 761		spin_lock(&fs_info->ordered_root_lock);
 762		if (nr != U64_MAX) {
 763			nr -= done;
 764		}
 765	}
 766	list_splice_tail(&splice, &fs_info->ordered_roots);
 767	spin_unlock(&fs_info->ordered_root_lock);
 768	mutex_unlock(&fs_info->ordered_operations_mutex);
 769}
 770
 771/*
 772 * Start IO and wait for a given ordered extent to finish.
 773 *
 774 * Wait on page writeback for all the pages in the extent and the IO completion
 775 * code to insert metadata into the btree corresponding to the extent.
 776 */
 777void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry)
 778{
 779	u64 start = entry->file_offset;
 780	u64 end = start + entry->num_bytes - 1;
 781	struct btrfs_inode *inode = BTRFS_I(entry->inode);
 782	bool freespace_inode;
 783
 784	trace_btrfs_ordered_extent_start(inode, entry);
 785
 786	/*
 787	 * If this is a free space inode do not take the ordered extents lockdep
 788	 * map.
 789	 */
 790	freespace_inode = btrfs_is_free_space_inode(inode);
 791
 792	/*
 793	 * pages in the range can be dirty, clean or writeback.  We
 794	 * start IO on any dirty ones so the wait doesn't stall waiting
 795	 * for the flusher thread to find them
 796	 */
 797	if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 798		filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
 799
 800	if (!freespace_inode)
 801		btrfs_might_wait_for_event(inode->root->fs_info, btrfs_ordered_extent);
 802	wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE, &entry->flags));
 803}
 804
 805/*
 806 * Used to wait on ordered extents across a large range of bytes.
 807 */
 808int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 809{
 810	int ret = 0;
 811	int ret_wb = 0;
 812	u64 end;
 813	u64 orig_end;
 814	struct btrfs_ordered_extent *ordered;
 815
 816	if (start + len < start) {
 817		orig_end = OFFSET_MAX;
 818	} else {
 819		orig_end = start + len - 1;
 820		if (orig_end > OFFSET_MAX)
 821			orig_end = OFFSET_MAX;
 822	}
 823
 824	/* start IO across the range first to instantiate any delalloc
 825	 * extents
 826	 */
 827	ret = btrfs_fdatawrite_range(inode, start, orig_end);
 828	if (ret)
 829		return ret;
 830
 831	/*
 832	 * If we have a writeback error don't return immediately. Wait first
 833	 * for any ordered extents that haven't completed yet. This is to make
 834	 * sure no one can dirty the same page ranges and call writepages()
 835	 * before the ordered extents complete - to avoid failures (-EEXIST)
 836	 * when adding the new ordered extents to the ordered tree.
 837	 */
 838	ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 839
 840	end = orig_end;
 841	while (1) {
 842		ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode), end);
 843		if (!ordered)
 844			break;
 845		if (ordered->file_offset > orig_end) {
 846			btrfs_put_ordered_extent(ordered);
 847			break;
 848		}
 849		if (ordered->file_offset + ordered->num_bytes <= start) {
 850			btrfs_put_ordered_extent(ordered);
 851			break;
 852		}
 853		btrfs_start_ordered_extent(ordered);
 854		end = ordered->file_offset;
 855		/*
 856		 * If the ordered extent had an error save the error but don't
 857		 * exit without waiting first for all other ordered extents in
 858		 * the range to complete.
 859		 */
 860		if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 861			ret = -EIO;
 862		btrfs_put_ordered_extent(ordered);
 863		if (end == 0 || end == start)
 864			break;
 865		end--;
 866	}
 867	return ret_wb ? ret_wb : ret;
 868}
 869
 870/*
 871 * find an ordered extent corresponding to file_offset.  return NULL if
 872 * nothing is found, otherwise take a reference on the extent and return it
 873 */
 874struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
 875							 u64 file_offset)
 876{
 877	struct rb_node *node;
 878	struct btrfs_ordered_extent *entry = NULL;
 879	unsigned long flags;
 880
 881	spin_lock_irqsave(&inode->ordered_tree_lock, flags);
 882	node = ordered_tree_search(inode, file_offset);
 883	if (!node)
 884		goto out;
 885
 886	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 887	if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 888		entry = NULL;
 889	if (entry) {
 890		refcount_inc(&entry->refs);
 891		trace_btrfs_ordered_extent_lookup(inode, entry);
 892	}
 893out:
 894	spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
 895	return entry;
 896}
 897
 898/* Since the DIO code tries to lock a wide area we need to look for any ordered
 899 * extents that exist in the range, rather than just the start of the range.
 900 */
 901struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 902		struct btrfs_inode *inode, u64 file_offset, u64 len)
 903{
 904	struct rb_node *node;
 905	struct btrfs_ordered_extent *entry = NULL;
 906
 907	spin_lock_irq(&inode->ordered_tree_lock);
 908	node = ordered_tree_search(inode, file_offset);
 909	if (!node) {
 910		node = ordered_tree_search(inode, file_offset + len);
 911		if (!node)
 912			goto out;
 913	}
 914
 915	while (1) {
 916		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 917		if (range_overlaps(entry, file_offset, len))
 918			break;
 919
 920		if (entry->file_offset >= file_offset + len) {
 921			entry = NULL;
 922			break;
 923		}
 924		entry = NULL;
 925		node = rb_next(node);
 926		if (!node)
 927			break;
 928	}
 929out:
 930	if (entry) {
 931		refcount_inc(&entry->refs);
 932		trace_btrfs_ordered_extent_lookup_range(inode, entry);
 933	}
 934	spin_unlock_irq(&inode->ordered_tree_lock);
 935	return entry;
 936}
 937
 938/*
 939 * Adds all ordered extents to the given list. The list ends up sorted by the
 940 * file_offset of the ordered extents.
 941 */
 942void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
 943					   struct list_head *list)
 944{
 945	struct rb_node *n;
 946
 947	ASSERT(inode_is_locked(&inode->vfs_inode));
 948
 949	spin_lock_irq(&inode->ordered_tree_lock);
 950	for (n = rb_first(&inode->ordered_tree); n; n = rb_next(n)) {
 951		struct btrfs_ordered_extent *ordered;
 952
 953		ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 954
 955		if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 956			continue;
 957
 958		ASSERT(list_empty(&ordered->log_list));
 959		list_add_tail(&ordered->log_list, list);
 960		refcount_inc(&ordered->refs);
 961		trace_btrfs_ordered_extent_lookup_for_logging(inode, ordered);
 962	}
 963	spin_unlock_irq(&inode->ordered_tree_lock);
 964}
 965
 966/*
 967 * lookup and return any extent before 'file_offset'.  NULL is returned
 968 * if none is found
 969 */
 970struct btrfs_ordered_extent *
 971btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
 972{
 973	struct rb_node *node;
 974	struct btrfs_ordered_extent *entry = NULL;
 975
 976	spin_lock_irq(&inode->ordered_tree_lock);
 977	node = ordered_tree_search(inode, file_offset);
 978	if (!node)
 979		goto out;
 980
 981	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 982	refcount_inc(&entry->refs);
 983	trace_btrfs_ordered_extent_lookup_first(inode, entry);
 984out:
 985	spin_unlock_irq(&inode->ordered_tree_lock);
 986	return entry;
 987}
 988
 989/*
 990 * Lookup the first ordered extent that overlaps the range
 991 * [@file_offset, @file_offset + @len).
 992 *
 993 * The difference between this and btrfs_lookup_first_ordered_extent() is
 994 * that this one won't return any ordered extent that does not overlap the range.
 995 * And the difference against btrfs_lookup_ordered_extent() is, this function
 996 * ensures the first ordered extent gets returned.
 997 */
 998struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
 999			struct btrfs_inode *inode, u64 file_offset, u64 len)
1000{
1001	struct rb_node *node;
1002	struct rb_node *cur;
1003	struct rb_node *prev;
1004	struct rb_node *next;
1005	struct btrfs_ordered_extent *entry = NULL;
1006
1007	spin_lock_irq(&inode->ordered_tree_lock);
1008	node = inode->ordered_tree.rb_node;
1009	/*
1010	 * Here we don't want to use tree_search() which will use tree->last
1011	 * and screw up the search order.
1012	 * And __tree_search() can't return the adjacent ordered extents
1013	 * either, thus here we do our own search.
1014	 */
1015	while (node) {
1016		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
1017
1018		if (file_offset < entry->file_offset) {
1019			node = node->rb_left;
1020		} else if (file_offset >= entry_end(entry)) {
1021			node = node->rb_right;
1022		} else {
1023			/*
1024			 * Direct hit, got an ordered extent that starts at
1025			 * @file_offset
1026			 */
1027			goto out;
1028		}
1029	}
1030	if (!entry) {
1031		/* Empty tree */
1032		goto out;
1033	}
1034
1035	cur = &entry->rb_node;
1036	/* We got an entry around @file_offset, check adjacent entries */
1037	if (entry->file_offset < file_offset) {
1038		prev = cur;
1039		next = rb_next(cur);
1040	} else {
1041		prev = rb_prev(cur);
1042		next = cur;
1043	}
1044	if (prev) {
1045		entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
1046		if (range_overlaps(entry, file_offset, len))
1047			goto out;
1048	}
1049	if (next) {
1050		entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
1051		if (range_overlaps(entry, file_offset, len))
1052			goto out;
1053	}
1054	/* No ordered extent in the range */
1055	entry = NULL;
1056out:
1057	if (entry) {
1058		refcount_inc(&entry->refs);
1059		trace_btrfs_ordered_extent_lookup_first_range(inode, entry);
1060	}
1061
1062	spin_unlock_irq(&inode->ordered_tree_lock);
1063	return entry;
1064}
1065
1066/*
1067 * Lock the passed range and ensures all pending ordered extents in it are run
1068 * to completion.
1069 *
1070 * @inode:        Inode whose ordered tree is to be searched
1071 * @start:        Beginning of range to flush
1072 * @end:          Last byte of range to lock
1073 * @cached_state: If passed, will return the extent state responsible for the
1074 *                locked range. It's the caller's responsibility to free the
1075 *                cached state.
1076 *
1077 * Always return with the given range locked, ensuring after it's called no
1078 * order extent can be pending.
1079 */
1080void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
1081					u64 end,
1082					struct extent_state **cached_state)
1083{
1084	struct btrfs_ordered_extent *ordered;
1085	struct extent_state *cache = NULL;
1086	struct extent_state **cachedp = &cache;
1087
1088	if (cached_state)
1089		cachedp = cached_state;
1090
1091	while (1) {
1092		lock_extent(&inode->io_tree, start, end, cachedp);
1093		ordered = btrfs_lookup_ordered_range(inode, start,
1094						     end - start + 1);
1095		if (!ordered) {
1096			/*
1097			 * If no external cached_state has been passed then
1098			 * decrement the extra ref taken for cachedp since we
1099			 * aren't exposing it outside of this function
1100			 */
1101			if (!cached_state)
1102				refcount_dec(&cache->refs);
1103			break;
1104		}
1105		unlock_extent(&inode->io_tree, start, end, cachedp);
1106		btrfs_start_ordered_extent(ordered);
1107		btrfs_put_ordered_extent(ordered);
1108	}
1109}
1110
1111/*
1112 * Lock the passed range and ensure all pending ordered extents in it are run
1113 * to completion in nowait mode.
1114 *
1115 * Return true if btrfs_lock_ordered_range does not return any extents,
1116 * otherwise false.
1117 */
1118bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
1119				  struct extent_state **cached_state)
1120{
1121	struct btrfs_ordered_extent *ordered;
1122
1123	if (!try_lock_extent(&inode->io_tree, start, end, cached_state))
1124		return false;
1125
1126	ordered = btrfs_lookup_ordered_range(inode, start, end - start + 1);
1127	if (!ordered)
1128		return true;
1129
1130	btrfs_put_ordered_extent(ordered);
1131	unlock_extent(&inode->io_tree, start, end, cached_state);
1132
1133	return false;
1134}
1135
1136/* Split out a new ordered extent for this first @len bytes of @ordered. */
1137struct btrfs_ordered_extent *btrfs_split_ordered_extent(
1138			struct btrfs_ordered_extent *ordered, u64 len)
1139{
1140	struct btrfs_inode *inode = BTRFS_I(ordered->inode);
1141	struct btrfs_root *root = inode->root;
1142	struct btrfs_fs_info *fs_info = root->fs_info;
1143	u64 file_offset = ordered->file_offset;
1144	u64 disk_bytenr = ordered->disk_bytenr;
1145	unsigned long flags = ordered->flags;
1146	struct btrfs_ordered_sum *sum, *tmpsum;
1147	struct btrfs_ordered_extent *new;
1148	struct rb_node *node;
1149	u64 offset = 0;
1150
1151	trace_btrfs_ordered_extent_split(inode, ordered);
1152
1153	ASSERT(!(flags & (1U << BTRFS_ORDERED_COMPRESSED)));
1154
1155	/*
1156	 * The entire bio must be covered by the ordered extent, but we can't
1157	 * reduce the original extent to a zero length either.
1158	 */
1159	if (WARN_ON_ONCE(len >= ordered->num_bytes))
1160		return ERR_PTR(-EINVAL);
1161	/* We cannot split partially completed ordered extents. */
1162	if (ordered->bytes_left) {
1163		ASSERT(!(flags & ~BTRFS_ORDERED_TYPE_FLAGS));
1164		if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes))
1165			return ERR_PTR(-EINVAL);
1166	}
1167	/* We cannot split a compressed ordered extent. */
1168	if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes))
1169		return ERR_PTR(-EINVAL);
1170
1171	new = alloc_ordered_extent(inode, file_offset, len, len, disk_bytenr,
1172				   len, 0, flags, ordered->compress_type);
1173	if (IS_ERR(new))
1174		return new;
1175
1176	/* One ref for the tree. */
1177	refcount_inc(&new->refs);
1178
1179	spin_lock_irq(&root->ordered_extent_lock);
1180	spin_lock(&inode->ordered_tree_lock);
1181	/* Remove from tree once */
1182	node = &ordered->rb_node;
1183	rb_erase(node, &inode->ordered_tree);
1184	RB_CLEAR_NODE(node);
1185	if (inode->ordered_tree_last == node)
1186		inode->ordered_tree_last = NULL;
1187
1188	ordered->file_offset += len;
1189	ordered->disk_bytenr += len;
1190	ordered->num_bytes -= len;
1191	ordered->disk_num_bytes -= len;
 
1192
1193	if (test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags)) {
1194		ASSERT(ordered->bytes_left == 0);
1195		new->bytes_left = 0;
1196	} else {
1197		ordered->bytes_left -= len;
1198	}
1199
1200	if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags)) {
1201		if (ordered->truncated_len > len) {
1202			ordered->truncated_len -= len;
1203		} else {
1204			new->truncated_len = ordered->truncated_len;
1205			ordered->truncated_len = 0;
1206		}
1207	}
1208
1209	list_for_each_entry_safe(sum, tmpsum, &ordered->list, list) {
1210		if (offset == len)
1211			break;
1212		list_move_tail(&sum->list, &new->list);
1213		offset += sum->len;
1214	}
1215
1216	/* Re-insert the node */
1217	node = tree_insert(&inode->ordered_tree, ordered->file_offset,
1218			   &ordered->rb_node);
1219	if (node)
1220		btrfs_panic(fs_info, -EEXIST,
1221			"zoned: inconsistency in ordered tree at offset %llu",
1222			ordered->file_offset);
1223
1224	node = tree_insert(&inode->ordered_tree, new->file_offset, &new->rb_node);
1225	if (node)
1226		btrfs_panic(fs_info, -EEXIST,
1227			"zoned: inconsistency in ordered tree at offset %llu",
1228			new->file_offset);
1229	spin_unlock(&inode->ordered_tree_lock);
1230
1231	list_add_tail(&new->root_extent_list, &root->ordered_extents);
1232	root->nr_ordered_extents++;
1233	spin_unlock_irq(&root->ordered_extent_lock);
1234	return new;
1235}
1236
1237int __init ordered_data_init(void)
1238{
1239	btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1240				     sizeof(struct btrfs_ordered_extent), 0,
1241				     SLAB_MEM_SPREAD,
1242				     NULL);
1243	if (!btrfs_ordered_extent_cache)
1244		return -ENOMEM;
1245
1246	return 0;
1247}
1248
1249void __cold ordered_data_exit(void)
1250{
1251	kmem_cache_destroy(btrfs_ordered_extent_cache);
1252}
v6.9.4
   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 "messages.h"
  11#include "misc.h"
  12#include "ctree.h"
  13#include "transaction.h"
  14#include "btrfs_inode.h"
  15#include "extent_io.h"
  16#include "disk-io.h"
  17#include "compression.h"
  18#include "delalloc-space.h"
  19#include "qgroup.h"
  20#include "subpage.h"
  21#include "file.h"
 
  22
  23static struct kmem_cache *btrfs_ordered_extent_cache;
  24
  25static u64 entry_end(struct btrfs_ordered_extent *entry)
  26{
  27	if (entry->file_offset + entry->num_bytes < entry->file_offset)
  28		return (u64)-1;
  29	return entry->file_offset + entry->num_bytes;
  30}
  31
  32/* returns NULL if the insertion worked, or it returns the node it did find
  33 * in the tree
  34 */
  35static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
  36				   struct rb_node *node)
  37{
  38	struct rb_node **p = &root->rb_node;
  39	struct rb_node *parent = NULL;
  40	struct btrfs_ordered_extent *entry;
  41
  42	while (*p) {
  43		parent = *p;
  44		entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
  45
  46		if (file_offset < entry->file_offset)
  47			p = &(*p)->rb_left;
  48		else if (file_offset >= entry_end(entry))
  49			p = &(*p)->rb_right;
  50		else
  51			return parent;
  52	}
  53
  54	rb_link_node(node, parent, p);
  55	rb_insert_color(node, root);
  56	return NULL;
  57}
  58
  59/*
  60 * look for a given offset in the tree, and if it can't be found return the
  61 * first lesser offset
  62 */
  63static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
  64				     struct rb_node **prev_ret)
  65{
  66	struct rb_node *n = root->rb_node;
  67	struct rb_node *prev = NULL;
  68	struct rb_node *test;
  69	struct btrfs_ordered_extent *entry;
  70	struct btrfs_ordered_extent *prev_entry = NULL;
  71
  72	while (n) {
  73		entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
  74		prev = n;
  75		prev_entry = entry;
  76
  77		if (file_offset < entry->file_offset)
  78			n = n->rb_left;
  79		else if (file_offset >= entry_end(entry))
  80			n = n->rb_right;
  81		else
  82			return n;
  83	}
  84	if (!prev_ret)
  85		return NULL;
  86
  87	while (prev && file_offset >= entry_end(prev_entry)) {
  88		test = rb_next(prev);
  89		if (!test)
  90			break;
  91		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
  92				      rb_node);
  93		if (file_offset < entry_end(prev_entry))
  94			break;
  95
  96		prev = test;
  97	}
  98	if (prev)
  99		prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
 100				      rb_node);
 101	while (prev && file_offset < entry_end(prev_entry)) {
 102		test = rb_prev(prev);
 103		if (!test)
 104			break;
 105		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 106				      rb_node);
 107		prev = test;
 108	}
 109	*prev_ret = prev;
 110	return NULL;
 111}
 112
 113static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
 114			  u64 len)
 115{
 116	if (file_offset + len <= entry->file_offset ||
 117	    entry->file_offset + entry->num_bytes <= file_offset)
 118		return 0;
 119	return 1;
 120}
 121
 122/*
 123 * look find the first ordered struct that has this offset, otherwise
 124 * the first one less than this offset
 125 */
 126static inline struct rb_node *ordered_tree_search(struct btrfs_inode *inode,
 127						  u64 file_offset)
 128{
 129	struct rb_node *prev = NULL;
 130	struct rb_node *ret;
 131	struct btrfs_ordered_extent *entry;
 132
 133	if (inode->ordered_tree_last) {
 134		entry = rb_entry(inode->ordered_tree_last, struct btrfs_ordered_extent,
 135				 rb_node);
 136		if (in_range(file_offset, entry->file_offset, entry->num_bytes))
 137			return inode->ordered_tree_last;
 138	}
 139	ret = __tree_search(&inode->ordered_tree, file_offset, &prev);
 140	if (!ret)
 141		ret = prev;
 142	if (ret)
 143		inode->ordered_tree_last = ret;
 144	return ret;
 145}
 146
 147static struct btrfs_ordered_extent *alloc_ordered_extent(
 148			struct btrfs_inode *inode, u64 file_offset, u64 num_bytes,
 149			u64 ram_bytes, u64 disk_bytenr, u64 disk_num_bytes,
 150			u64 offset, unsigned long flags, int compress_type)
 151{
 152	struct btrfs_ordered_extent *entry;
 153	int ret;
 154	u64 qgroup_rsv = 0;
 155
 156	if (flags &
 157	    ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
 158		/* For nocow write, we can release the qgroup rsv right now */
 159		ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes, &qgroup_rsv);
 160		if (ret < 0)
 161			return ERR_PTR(ret);
 162	} else {
 163		/*
 164		 * The ordered extent has reserved qgroup space, release now
 165		 * and pass the reserved number for qgroup_record to free.
 166		 */
 167		ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes, &qgroup_rsv);
 168		if (ret < 0)
 169			return ERR_PTR(ret);
 170	}
 171	entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 172	if (!entry)
 173		return ERR_PTR(-ENOMEM);
 174
 175	entry->file_offset = file_offset;
 176	entry->num_bytes = num_bytes;
 177	entry->ram_bytes = ram_bytes;
 178	entry->disk_bytenr = disk_bytenr;
 179	entry->disk_num_bytes = disk_num_bytes;
 180	entry->offset = offset;
 181	entry->bytes_left = num_bytes;
 182	entry->inode = igrab(&inode->vfs_inode);
 183	entry->compress_type = compress_type;
 184	entry->truncated_len = (u64)-1;
 185	entry->qgroup_rsv = qgroup_rsv;
 186	entry->flags = flags;
 187	refcount_set(&entry->refs, 1);
 188	init_waitqueue_head(&entry->wait);
 189	INIT_LIST_HEAD(&entry->list);
 190	INIT_LIST_HEAD(&entry->log_list);
 191	INIT_LIST_HEAD(&entry->root_extent_list);
 192	INIT_LIST_HEAD(&entry->work_list);
 193	INIT_LIST_HEAD(&entry->bioc_list);
 194	init_completion(&entry->completion);
 195
 196	/*
 197	 * We don't need the count_max_extents here, we can assume that all of
 198	 * that work has been done at higher layers, so this is truly the
 199	 * smallest the extent is going to get.
 200	 */
 201	spin_lock(&inode->lock);
 202	btrfs_mod_outstanding_extents(inode, 1);
 203	spin_unlock(&inode->lock);
 204
 205	return entry;
 206}
 207
 208static void insert_ordered_extent(struct btrfs_ordered_extent *entry)
 209{
 210	struct btrfs_inode *inode = BTRFS_I(entry->inode);
 211	struct btrfs_root *root = inode->root;
 212	struct btrfs_fs_info *fs_info = root->fs_info;
 213	struct rb_node *node;
 214
 215	trace_btrfs_ordered_extent_add(inode, entry);
 216
 217	percpu_counter_add_batch(&fs_info->ordered_bytes, entry->num_bytes,
 218				 fs_info->delalloc_batch);
 219
 220	/* One ref for the tree. */
 221	refcount_inc(&entry->refs);
 222
 223	spin_lock_irq(&inode->ordered_tree_lock);
 224	node = tree_insert(&inode->ordered_tree, entry->file_offset,
 225			   &entry->rb_node);
 226	if (node)
 227		btrfs_panic(fs_info, -EEXIST,
 228				"inconsistency in ordered tree at offset %llu",
 229				entry->file_offset);
 230	spin_unlock_irq(&inode->ordered_tree_lock);
 231
 232	spin_lock(&root->ordered_extent_lock);
 233	list_add_tail(&entry->root_extent_list,
 234		      &root->ordered_extents);
 235	root->nr_ordered_extents++;
 236	if (root->nr_ordered_extents == 1) {
 237		spin_lock(&fs_info->ordered_root_lock);
 238		BUG_ON(!list_empty(&root->ordered_root));
 239		list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 240		spin_unlock(&fs_info->ordered_root_lock);
 241	}
 242	spin_unlock(&root->ordered_extent_lock);
 243}
 244
 245/*
 246 * Add an ordered extent to the per-inode tree.
 247 *
 248 * @inode:           Inode that this extent is for.
 249 * @file_offset:     Logical offset in file where the extent starts.
 250 * @num_bytes:       Logical length of extent in file.
 251 * @ram_bytes:       Full length of unencoded data.
 252 * @disk_bytenr:     Offset of extent on disk.
 253 * @disk_num_bytes:  Size of extent on disk.
 254 * @offset:          Offset into unencoded data where file data starts.
 255 * @flags:           Flags specifying type of extent (1 << BTRFS_ORDERED_*).
 256 * @compress_type:   Compression algorithm used for data.
 257 *
 258 * Most of these parameters correspond to &struct btrfs_file_extent_item. The
 259 * tree is given a single reference on the ordered extent that was inserted, and
 260 * the returned pointer is given a second reference.
 261 *
 262 * Return: the new ordered extent or error pointer.
 263 */
 264struct btrfs_ordered_extent *btrfs_alloc_ordered_extent(
 265			struct btrfs_inode *inode, u64 file_offset,
 266			u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
 267			u64 disk_num_bytes, u64 offset, unsigned long flags,
 268			int compress_type)
 269{
 270	struct btrfs_ordered_extent *entry;
 271
 272	ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
 273
 274	entry = alloc_ordered_extent(inode, file_offset, num_bytes, ram_bytes,
 275				     disk_bytenr, disk_num_bytes, offset, flags,
 276				     compress_type);
 277	if (!IS_ERR(entry))
 278		insert_ordered_extent(entry);
 279	return entry;
 280}
 281
 282/*
 283 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 284 * when an ordered extent is finished.  If the list covers more than one
 285 * ordered extent, it is split across multiples.
 286 */
 287void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 288			   struct btrfs_ordered_sum *sum)
 289{
 290	struct btrfs_inode *inode = BTRFS_I(entry->inode);
 291
 292	spin_lock_irq(&inode->ordered_tree_lock);
 293	list_add_tail(&sum->list, &entry->list);
 294	spin_unlock_irq(&inode->ordered_tree_lock);
 295}
 296
 297static void finish_ordered_fn(struct btrfs_work *work)
 298{
 299	struct btrfs_ordered_extent *ordered_extent;
 300
 301	ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
 302	btrfs_finish_ordered_io(ordered_extent);
 303}
 304
 305static bool can_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
 306				      struct page *page, u64 file_offset,
 307				      u64 len, bool uptodate)
 308{
 309	struct btrfs_inode *inode = BTRFS_I(ordered->inode);
 310	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 311
 312	lockdep_assert_held(&inode->ordered_tree_lock);
 313
 314	if (page) {
 315		ASSERT(page->mapping);
 316		ASSERT(page_offset(page) <= file_offset);
 317		ASSERT(file_offset + len <= page_offset(page) + PAGE_SIZE);
 318
 319		/*
 320		 * Ordered (Private2) bit indicates whether we still have
 321		 * pending io unfinished for the ordered extent.
 322		 *
 323		 * If there's no such bit, we need to skip to next range.
 324		 */
 325		if (!btrfs_folio_test_ordered(fs_info, page_folio(page),
 326					      file_offset, len))
 327			return false;
 328		btrfs_folio_clear_ordered(fs_info, page_folio(page), file_offset, len);
 329	}
 330
 331	/* Now we're fine to update the accounting. */
 332	if (WARN_ON_ONCE(len > ordered->bytes_left)) {
 333		btrfs_crit(fs_info,
 334"bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%llu left=%llu",
 335			   inode->root->root_key.objectid, btrfs_ino(inode),
 336			   ordered->file_offset, ordered->num_bytes,
 337			   len, ordered->bytes_left);
 338		ordered->bytes_left = 0;
 339	} else {
 340		ordered->bytes_left -= len;
 341	}
 342
 343	if (!uptodate)
 344		set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
 345
 346	if (ordered->bytes_left)
 347		return false;
 348
 349	/*
 350	 * All the IO of the ordered extent is finished, we need to queue
 351	 * the finish_func to be executed.
 352	 */
 353	set_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags);
 354	cond_wake_up(&ordered->wait);
 355	refcount_inc(&ordered->refs);
 356	trace_btrfs_ordered_extent_mark_finished(inode, ordered);
 357	return true;
 358}
 359
 360static void btrfs_queue_ordered_fn(struct btrfs_ordered_extent *ordered)
 361{
 362	struct btrfs_inode *inode = BTRFS_I(ordered->inode);
 363	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 364	struct btrfs_workqueue *wq = btrfs_is_free_space_inode(inode) ?
 365		fs_info->endio_freespace_worker : fs_info->endio_write_workers;
 366
 367	btrfs_init_work(&ordered->work, finish_ordered_fn, NULL);
 368	btrfs_queue_work(wq, &ordered->work);
 369}
 370
 371bool btrfs_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
 372				 struct page *page, u64 file_offset, u64 len,
 373				 bool uptodate)
 374{
 375	struct btrfs_inode *inode = BTRFS_I(ordered->inode);
 376	unsigned long flags;
 377	bool ret;
 378
 379	trace_btrfs_finish_ordered_extent(inode, file_offset, len, uptodate);
 380
 381	spin_lock_irqsave(&inode->ordered_tree_lock, flags);
 382	ret = can_finish_ordered_extent(ordered, page, file_offset, len, uptodate);
 383	spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
 384
 385	if (ret)
 386		btrfs_queue_ordered_fn(ordered);
 387	return ret;
 388}
 389
 390/*
 391 * Mark all ordered extents io inside the specified range finished.
 392 *
 393 * @page:	 The involved page for the operation.
 394 *		 For uncompressed buffered IO, the page status also needs to be
 395 *		 updated to indicate whether the pending ordered io is finished.
 396 *		 Can be NULL for direct IO and compressed write.
 397 *		 For these cases, callers are ensured they won't execute the
 398 *		 endio function twice.
 399 *
 400 * This function is called for endio, thus the range must have ordered
 401 * extent(s) covering it.
 402 */
 403void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
 404				    struct page *page, u64 file_offset,
 405				    u64 num_bytes, bool uptodate)
 406{
 407	struct rb_node *node;
 408	struct btrfs_ordered_extent *entry = NULL;
 409	unsigned long flags;
 410	u64 cur = file_offset;
 411
 412	trace_btrfs_writepage_end_io_hook(inode, file_offset,
 413					  file_offset + num_bytes - 1,
 414					  uptodate);
 415
 416	spin_lock_irqsave(&inode->ordered_tree_lock, flags);
 417	while (cur < file_offset + num_bytes) {
 418		u64 entry_end;
 419		u64 end;
 420		u32 len;
 421
 422		node = ordered_tree_search(inode, cur);
 423		/* No ordered extents at all */
 424		if (!node)
 425			break;
 426
 427		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 428		entry_end = entry->file_offset + entry->num_bytes;
 429		/*
 430		 * |<-- OE --->|  |
 431		 *		  cur
 432		 * Go to next OE.
 433		 */
 434		if (cur >= entry_end) {
 435			node = rb_next(node);
 436			/* No more ordered extents, exit */
 437			if (!node)
 438				break;
 439			entry = rb_entry(node, struct btrfs_ordered_extent,
 440					 rb_node);
 441
 442			/* Go to next ordered extent and continue */
 443			cur = entry->file_offset;
 444			continue;
 445		}
 446		/*
 447		 * |	|<--- OE --->|
 448		 * cur
 449		 * Go to the start of OE.
 450		 */
 451		if (cur < entry->file_offset) {
 452			cur = entry->file_offset;
 453			continue;
 454		}
 455
 456		/*
 457		 * Now we are definitely inside one ordered extent.
 458		 *
 459		 * |<--- OE --->|
 460		 *	|
 461		 *	cur
 462		 */
 463		end = min(entry->file_offset + entry->num_bytes,
 464			  file_offset + num_bytes) - 1;
 465		ASSERT(end + 1 - cur < U32_MAX);
 466		len = end + 1 - cur;
 467
 468		if (can_finish_ordered_extent(entry, page, cur, len, uptodate)) {
 469			spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
 470			btrfs_queue_ordered_fn(entry);
 471			spin_lock_irqsave(&inode->ordered_tree_lock, flags);
 472		}
 473		cur += len;
 474	}
 475	spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
 476}
 477
 478/*
 479 * Finish IO for one ordered extent across a given range.  The range can only
 480 * contain one ordered extent.
 481 *
 482 * @cached:	 The cached ordered extent. If not NULL, we can skip the tree
 483 *               search and use the ordered extent directly.
 484 * 		 Will be also used to store the finished ordered extent.
 485 * @file_offset: File offset for the finished IO
 486 * @io_size:	 Length of the finish IO range
 487 *
 488 * Return true if the ordered extent is finished in the range, and update
 489 * @cached.
 490 * Return false otherwise.
 491 *
 492 * NOTE: The range can NOT cross multiple ordered extents.
 493 * Thus caller should ensure the range doesn't cross ordered extents.
 494 */
 495bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 496				    struct btrfs_ordered_extent **cached,
 497				    u64 file_offset, u64 io_size)
 498{
 499	struct rb_node *node;
 500	struct btrfs_ordered_extent *entry = NULL;
 501	unsigned long flags;
 502	bool finished = false;
 503
 504	spin_lock_irqsave(&inode->ordered_tree_lock, flags);
 505	if (cached && *cached) {
 506		entry = *cached;
 507		goto have_entry;
 508	}
 509
 510	node = ordered_tree_search(inode, file_offset);
 511	if (!node)
 512		goto out;
 513
 514	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 515have_entry:
 516	if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 517		goto out;
 518
 519	if (io_size > entry->bytes_left)
 520		btrfs_crit(inode->root->fs_info,
 521			   "bad ordered accounting left %llu size %llu",
 522		       entry->bytes_left, io_size);
 523
 524	entry->bytes_left -= io_size;
 525
 526	if (entry->bytes_left == 0) {
 527		/*
 528		 * Ensure only one caller can set the flag and finished_ret
 529		 * accordingly
 530		 */
 531		finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 532		/* test_and_set_bit implies a barrier */
 533		cond_wake_up_nomb(&entry->wait);
 534	}
 535out:
 536	if (finished && cached && entry) {
 537		*cached = entry;
 538		refcount_inc(&entry->refs);
 539		trace_btrfs_ordered_extent_dec_test_pending(inode, entry);
 540	}
 541	spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
 542	return finished;
 543}
 544
 545/*
 546 * used to drop a reference on an ordered extent.  This will free
 547 * the extent if the last reference is dropped
 548 */
 549void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 550{
 551	struct list_head *cur;
 552	struct btrfs_ordered_sum *sum;
 553
 554	trace_btrfs_ordered_extent_put(BTRFS_I(entry->inode), entry);
 555
 556	if (refcount_dec_and_test(&entry->refs)) {
 557		ASSERT(list_empty(&entry->root_extent_list));
 558		ASSERT(list_empty(&entry->log_list));
 559		ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 560		if (entry->inode)
 561			btrfs_add_delayed_iput(BTRFS_I(entry->inode));
 562		while (!list_empty(&entry->list)) {
 563			cur = entry->list.next;
 564			sum = list_entry(cur, struct btrfs_ordered_sum, list);
 565			list_del(&sum->list);
 566			kvfree(sum);
 567		}
 568		kmem_cache_free(btrfs_ordered_extent_cache, entry);
 569	}
 570}
 571
 572/*
 573 * remove an ordered extent from the tree.  No references are dropped
 574 * and waiters are woken up.
 575 */
 576void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
 577				 struct btrfs_ordered_extent *entry)
 578{
 579	struct btrfs_root *root = btrfs_inode->root;
 580	struct btrfs_fs_info *fs_info = root->fs_info;
 581	struct rb_node *node;
 582	bool pending;
 583	bool freespace_inode;
 584
 585	/*
 586	 * If this is a free space inode the thread has not acquired the ordered
 587	 * extents lockdep map.
 588	 */
 589	freespace_inode = btrfs_is_free_space_inode(btrfs_inode);
 590
 591	btrfs_lockdep_acquire(fs_info, btrfs_trans_pending_ordered);
 592	/* This is paired with btrfs_alloc_ordered_extent. */
 593	spin_lock(&btrfs_inode->lock);
 594	btrfs_mod_outstanding_extents(btrfs_inode, -1);
 595	spin_unlock(&btrfs_inode->lock);
 596	if (root != fs_info->tree_root) {
 597		u64 release;
 598
 599		if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
 600			release = entry->disk_num_bytes;
 601		else
 602			release = entry->num_bytes;
 603		btrfs_delalloc_release_metadata(btrfs_inode, release,
 604						test_bit(BTRFS_ORDERED_IOERR,
 605							 &entry->flags));
 606	}
 607
 608	percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
 609				 fs_info->delalloc_batch);
 610
 611	spin_lock_irq(&btrfs_inode->ordered_tree_lock);
 612	node = &entry->rb_node;
 613	rb_erase(node, &btrfs_inode->ordered_tree);
 614	RB_CLEAR_NODE(node);
 615	if (btrfs_inode->ordered_tree_last == node)
 616		btrfs_inode->ordered_tree_last = NULL;
 617	set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 618	pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
 619	spin_unlock_irq(&btrfs_inode->ordered_tree_lock);
 620
 621	/*
 622	 * The current running transaction is waiting on us, we need to let it
 623	 * know that we're complete and wake it up.
 624	 */
 625	if (pending) {
 626		struct btrfs_transaction *trans;
 627
 628		/*
 629		 * The checks for trans are just a formality, it should be set,
 630		 * but if it isn't we don't want to deref/assert under the spin
 631		 * lock, so be nice and check if trans is set, but ASSERT() so
 632		 * if it isn't set a developer will notice.
 633		 */
 634		spin_lock(&fs_info->trans_lock);
 635		trans = fs_info->running_transaction;
 636		if (trans)
 637			refcount_inc(&trans->use_count);
 638		spin_unlock(&fs_info->trans_lock);
 639
 640		ASSERT(trans || BTRFS_FS_ERROR(fs_info));
 641		if (trans) {
 642			if (atomic_dec_and_test(&trans->pending_ordered))
 643				wake_up(&trans->pending_wait);
 644			btrfs_put_transaction(trans);
 645		}
 646	}
 647
 648	btrfs_lockdep_release(fs_info, btrfs_trans_pending_ordered);
 649
 650	spin_lock(&root->ordered_extent_lock);
 651	list_del_init(&entry->root_extent_list);
 652	root->nr_ordered_extents--;
 653
 654	trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
 655
 656	if (!root->nr_ordered_extents) {
 657		spin_lock(&fs_info->ordered_root_lock);
 658		BUG_ON(list_empty(&root->ordered_root));
 659		list_del_init(&root->ordered_root);
 660		spin_unlock(&fs_info->ordered_root_lock);
 661	}
 662	spin_unlock(&root->ordered_extent_lock);
 663	wake_up(&entry->wait);
 664	if (!freespace_inode)
 665		btrfs_lockdep_release(fs_info, btrfs_ordered_extent);
 666}
 667
 668static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 669{
 670	struct btrfs_ordered_extent *ordered;
 671
 672	ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 673	btrfs_start_ordered_extent(ordered);
 674	complete(&ordered->completion);
 675}
 676
 677/*
 678 * wait for all the ordered extents in a root.  This is done when balancing
 679 * space between drives.
 680 */
 681u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 682			       const u64 range_start, const u64 range_len)
 683{
 684	struct btrfs_fs_info *fs_info = root->fs_info;
 685	LIST_HEAD(splice);
 686	LIST_HEAD(skipped);
 687	LIST_HEAD(works);
 688	struct btrfs_ordered_extent *ordered, *next;
 689	u64 count = 0;
 690	const u64 range_end = range_start + range_len;
 691
 692	mutex_lock(&root->ordered_extent_mutex);
 693	spin_lock(&root->ordered_extent_lock);
 694	list_splice_init(&root->ordered_extents, &splice);
 695	while (!list_empty(&splice) && nr) {
 696		ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 697					   root_extent_list);
 698
 699		if (range_end <= ordered->disk_bytenr ||
 700		    ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
 701			list_move_tail(&ordered->root_extent_list, &skipped);
 702			cond_resched_lock(&root->ordered_extent_lock);
 703			continue;
 704		}
 705
 706		list_move_tail(&ordered->root_extent_list,
 707			       &root->ordered_extents);
 708		refcount_inc(&ordered->refs);
 709		spin_unlock(&root->ordered_extent_lock);
 710
 711		btrfs_init_work(&ordered->flush_work,
 712				btrfs_run_ordered_extent_work, NULL);
 713		list_add_tail(&ordered->work_list, &works);
 714		btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 715
 716		cond_resched();
 717		spin_lock(&root->ordered_extent_lock);
 718		if (nr != U64_MAX)
 719			nr--;
 720		count++;
 721	}
 722	list_splice_tail(&skipped, &root->ordered_extents);
 723	list_splice_tail(&splice, &root->ordered_extents);
 724	spin_unlock(&root->ordered_extent_lock);
 725
 726	list_for_each_entry_safe(ordered, next, &works, work_list) {
 727		list_del_init(&ordered->work_list);
 728		wait_for_completion(&ordered->completion);
 729		btrfs_put_ordered_extent(ordered);
 730		cond_resched();
 731	}
 732	mutex_unlock(&root->ordered_extent_mutex);
 733
 734	return count;
 735}
 736
 737void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 738			     const u64 range_start, const u64 range_len)
 739{
 740	struct btrfs_root *root;
 741	LIST_HEAD(splice);
 742	u64 done;
 743
 744	mutex_lock(&fs_info->ordered_operations_mutex);
 745	spin_lock(&fs_info->ordered_root_lock);
 746	list_splice_init(&fs_info->ordered_roots, &splice);
 747	while (!list_empty(&splice) && nr) {
 748		root = list_first_entry(&splice, struct btrfs_root,
 749					ordered_root);
 750		root = btrfs_grab_root(root);
 751		BUG_ON(!root);
 752		list_move_tail(&root->ordered_root,
 753			       &fs_info->ordered_roots);
 754		spin_unlock(&fs_info->ordered_root_lock);
 755
 756		done = btrfs_wait_ordered_extents(root, nr,
 757						  range_start, range_len);
 758		btrfs_put_root(root);
 759
 760		spin_lock(&fs_info->ordered_root_lock);
 761		if (nr != U64_MAX) {
 762			nr -= done;
 763		}
 764	}
 765	list_splice_tail(&splice, &fs_info->ordered_roots);
 766	spin_unlock(&fs_info->ordered_root_lock);
 767	mutex_unlock(&fs_info->ordered_operations_mutex);
 768}
 769
 770/*
 771 * Start IO and wait for a given ordered extent to finish.
 772 *
 773 * Wait on page writeback for all the pages in the extent and the IO completion
 774 * code to insert metadata into the btree corresponding to the extent.
 775 */
 776void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry)
 777{
 778	u64 start = entry->file_offset;
 779	u64 end = start + entry->num_bytes - 1;
 780	struct btrfs_inode *inode = BTRFS_I(entry->inode);
 781	bool freespace_inode;
 782
 783	trace_btrfs_ordered_extent_start(inode, entry);
 784
 785	/*
 786	 * If this is a free space inode do not take the ordered extents lockdep
 787	 * map.
 788	 */
 789	freespace_inode = btrfs_is_free_space_inode(inode);
 790
 791	/*
 792	 * pages in the range can be dirty, clean or writeback.  We
 793	 * start IO on any dirty ones so the wait doesn't stall waiting
 794	 * for the flusher thread to find them
 795	 */
 796	if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 797		filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
 798
 799	if (!freespace_inode)
 800		btrfs_might_wait_for_event(inode->root->fs_info, btrfs_ordered_extent);
 801	wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE, &entry->flags));
 802}
 803
 804/*
 805 * Used to wait on ordered extents across a large range of bytes.
 806 */
 807int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 808{
 809	int ret = 0;
 810	int ret_wb = 0;
 811	u64 end;
 812	u64 orig_end;
 813	struct btrfs_ordered_extent *ordered;
 814
 815	if (start + len < start) {
 816		orig_end = OFFSET_MAX;
 817	} else {
 818		orig_end = start + len - 1;
 819		if (orig_end > OFFSET_MAX)
 820			orig_end = OFFSET_MAX;
 821	}
 822
 823	/* start IO across the range first to instantiate any delalloc
 824	 * extents
 825	 */
 826	ret = btrfs_fdatawrite_range(inode, start, orig_end);
 827	if (ret)
 828		return ret;
 829
 830	/*
 831	 * If we have a writeback error don't return immediately. Wait first
 832	 * for any ordered extents that haven't completed yet. This is to make
 833	 * sure no one can dirty the same page ranges and call writepages()
 834	 * before the ordered extents complete - to avoid failures (-EEXIST)
 835	 * when adding the new ordered extents to the ordered tree.
 836	 */
 837	ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 838
 839	end = orig_end;
 840	while (1) {
 841		ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode), end);
 842		if (!ordered)
 843			break;
 844		if (ordered->file_offset > orig_end) {
 845			btrfs_put_ordered_extent(ordered);
 846			break;
 847		}
 848		if (ordered->file_offset + ordered->num_bytes <= start) {
 849			btrfs_put_ordered_extent(ordered);
 850			break;
 851		}
 852		btrfs_start_ordered_extent(ordered);
 853		end = ordered->file_offset;
 854		/*
 855		 * If the ordered extent had an error save the error but don't
 856		 * exit without waiting first for all other ordered extents in
 857		 * the range to complete.
 858		 */
 859		if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 860			ret = -EIO;
 861		btrfs_put_ordered_extent(ordered);
 862		if (end == 0 || end == start)
 863			break;
 864		end--;
 865	}
 866	return ret_wb ? ret_wb : ret;
 867}
 868
 869/*
 870 * find an ordered extent corresponding to file_offset.  return NULL if
 871 * nothing is found, otherwise take a reference on the extent and return it
 872 */
 873struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
 874							 u64 file_offset)
 875{
 876	struct rb_node *node;
 877	struct btrfs_ordered_extent *entry = NULL;
 878	unsigned long flags;
 879
 880	spin_lock_irqsave(&inode->ordered_tree_lock, flags);
 881	node = ordered_tree_search(inode, file_offset);
 882	if (!node)
 883		goto out;
 884
 885	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 886	if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 887		entry = NULL;
 888	if (entry) {
 889		refcount_inc(&entry->refs);
 890		trace_btrfs_ordered_extent_lookup(inode, entry);
 891	}
 892out:
 893	spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
 894	return entry;
 895}
 896
 897/* Since the DIO code tries to lock a wide area we need to look for any ordered
 898 * extents that exist in the range, rather than just the start of the range.
 899 */
 900struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 901		struct btrfs_inode *inode, u64 file_offset, u64 len)
 902{
 903	struct rb_node *node;
 904	struct btrfs_ordered_extent *entry = NULL;
 905
 906	spin_lock_irq(&inode->ordered_tree_lock);
 907	node = ordered_tree_search(inode, file_offset);
 908	if (!node) {
 909		node = ordered_tree_search(inode, file_offset + len);
 910		if (!node)
 911			goto out;
 912	}
 913
 914	while (1) {
 915		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 916		if (range_overlaps(entry, file_offset, len))
 917			break;
 918
 919		if (entry->file_offset >= file_offset + len) {
 920			entry = NULL;
 921			break;
 922		}
 923		entry = NULL;
 924		node = rb_next(node);
 925		if (!node)
 926			break;
 927	}
 928out:
 929	if (entry) {
 930		refcount_inc(&entry->refs);
 931		trace_btrfs_ordered_extent_lookup_range(inode, entry);
 932	}
 933	spin_unlock_irq(&inode->ordered_tree_lock);
 934	return entry;
 935}
 936
 937/*
 938 * Adds all ordered extents to the given list. The list ends up sorted by the
 939 * file_offset of the ordered extents.
 940 */
 941void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
 942					   struct list_head *list)
 943{
 944	struct rb_node *n;
 945
 946	ASSERT(inode_is_locked(&inode->vfs_inode));
 947
 948	spin_lock_irq(&inode->ordered_tree_lock);
 949	for (n = rb_first(&inode->ordered_tree); n; n = rb_next(n)) {
 950		struct btrfs_ordered_extent *ordered;
 951
 952		ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 953
 954		if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 955			continue;
 956
 957		ASSERT(list_empty(&ordered->log_list));
 958		list_add_tail(&ordered->log_list, list);
 959		refcount_inc(&ordered->refs);
 960		trace_btrfs_ordered_extent_lookup_for_logging(inode, ordered);
 961	}
 962	spin_unlock_irq(&inode->ordered_tree_lock);
 963}
 964
 965/*
 966 * lookup and return any extent before 'file_offset'.  NULL is returned
 967 * if none is found
 968 */
 969struct btrfs_ordered_extent *
 970btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
 971{
 972	struct rb_node *node;
 973	struct btrfs_ordered_extent *entry = NULL;
 974
 975	spin_lock_irq(&inode->ordered_tree_lock);
 976	node = ordered_tree_search(inode, file_offset);
 977	if (!node)
 978		goto out;
 979
 980	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 981	refcount_inc(&entry->refs);
 982	trace_btrfs_ordered_extent_lookup_first(inode, entry);
 983out:
 984	spin_unlock_irq(&inode->ordered_tree_lock);
 985	return entry;
 986}
 987
 988/*
 989 * Lookup the first ordered extent that overlaps the range
 990 * [@file_offset, @file_offset + @len).
 991 *
 992 * The difference between this and btrfs_lookup_first_ordered_extent() is
 993 * that this one won't return any ordered extent that does not overlap the range.
 994 * And the difference against btrfs_lookup_ordered_extent() is, this function
 995 * ensures the first ordered extent gets returned.
 996 */
 997struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
 998			struct btrfs_inode *inode, u64 file_offset, u64 len)
 999{
1000	struct rb_node *node;
1001	struct rb_node *cur;
1002	struct rb_node *prev;
1003	struct rb_node *next;
1004	struct btrfs_ordered_extent *entry = NULL;
1005
1006	spin_lock_irq(&inode->ordered_tree_lock);
1007	node = inode->ordered_tree.rb_node;
1008	/*
1009	 * Here we don't want to use tree_search() which will use tree->last
1010	 * and screw up the search order.
1011	 * And __tree_search() can't return the adjacent ordered extents
1012	 * either, thus here we do our own search.
1013	 */
1014	while (node) {
1015		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
1016
1017		if (file_offset < entry->file_offset) {
1018			node = node->rb_left;
1019		} else if (file_offset >= entry_end(entry)) {
1020			node = node->rb_right;
1021		} else {
1022			/*
1023			 * Direct hit, got an ordered extent that starts at
1024			 * @file_offset
1025			 */
1026			goto out;
1027		}
1028	}
1029	if (!entry) {
1030		/* Empty tree */
1031		goto out;
1032	}
1033
1034	cur = &entry->rb_node;
1035	/* We got an entry around @file_offset, check adjacent entries */
1036	if (entry->file_offset < file_offset) {
1037		prev = cur;
1038		next = rb_next(cur);
1039	} else {
1040		prev = rb_prev(cur);
1041		next = cur;
1042	}
1043	if (prev) {
1044		entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
1045		if (range_overlaps(entry, file_offset, len))
1046			goto out;
1047	}
1048	if (next) {
1049		entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
1050		if (range_overlaps(entry, file_offset, len))
1051			goto out;
1052	}
1053	/* No ordered extent in the range */
1054	entry = NULL;
1055out:
1056	if (entry) {
1057		refcount_inc(&entry->refs);
1058		trace_btrfs_ordered_extent_lookup_first_range(inode, entry);
1059	}
1060
1061	spin_unlock_irq(&inode->ordered_tree_lock);
1062	return entry;
1063}
1064
1065/*
1066 * Lock the passed range and ensures all pending ordered extents in it are run
1067 * to completion.
1068 *
1069 * @inode:        Inode whose ordered tree is to be searched
1070 * @start:        Beginning of range to flush
1071 * @end:          Last byte of range to lock
1072 * @cached_state: If passed, will return the extent state responsible for the
1073 *                locked range. It's the caller's responsibility to free the
1074 *                cached state.
1075 *
1076 * Always return with the given range locked, ensuring after it's called no
1077 * order extent can be pending.
1078 */
1079void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
1080					u64 end,
1081					struct extent_state **cached_state)
1082{
1083	struct btrfs_ordered_extent *ordered;
1084	struct extent_state *cache = NULL;
1085	struct extent_state **cachedp = &cache;
1086
1087	if (cached_state)
1088		cachedp = cached_state;
1089
1090	while (1) {
1091		lock_extent(&inode->io_tree, start, end, cachedp);
1092		ordered = btrfs_lookup_ordered_range(inode, start,
1093						     end - start + 1);
1094		if (!ordered) {
1095			/*
1096			 * If no external cached_state has been passed then
1097			 * decrement the extra ref taken for cachedp since we
1098			 * aren't exposing it outside of this function
1099			 */
1100			if (!cached_state)
1101				refcount_dec(&cache->refs);
1102			break;
1103		}
1104		unlock_extent(&inode->io_tree, start, end, cachedp);
1105		btrfs_start_ordered_extent(ordered);
1106		btrfs_put_ordered_extent(ordered);
1107	}
1108}
1109
1110/*
1111 * Lock the passed range and ensure all pending ordered extents in it are run
1112 * to completion in nowait mode.
1113 *
1114 * Return true if btrfs_lock_ordered_range does not return any extents,
1115 * otherwise false.
1116 */
1117bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
1118				  struct extent_state **cached_state)
1119{
1120	struct btrfs_ordered_extent *ordered;
1121
1122	if (!try_lock_extent(&inode->io_tree, start, end, cached_state))
1123		return false;
1124
1125	ordered = btrfs_lookup_ordered_range(inode, start, end - start + 1);
1126	if (!ordered)
1127		return true;
1128
1129	btrfs_put_ordered_extent(ordered);
1130	unlock_extent(&inode->io_tree, start, end, cached_state);
1131
1132	return false;
1133}
1134
1135/* Split out a new ordered extent for this first @len bytes of @ordered. */
1136struct btrfs_ordered_extent *btrfs_split_ordered_extent(
1137			struct btrfs_ordered_extent *ordered, u64 len)
1138{
1139	struct btrfs_inode *inode = BTRFS_I(ordered->inode);
1140	struct btrfs_root *root = inode->root;
1141	struct btrfs_fs_info *fs_info = root->fs_info;
1142	u64 file_offset = ordered->file_offset;
1143	u64 disk_bytenr = ordered->disk_bytenr;
1144	unsigned long flags = ordered->flags;
1145	struct btrfs_ordered_sum *sum, *tmpsum;
1146	struct btrfs_ordered_extent *new;
1147	struct rb_node *node;
1148	u64 offset = 0;
1149
1150	trace_btrfs_ordered_extent_split(inode, ordered);
1151
1152	ASSERT(!(flags & (1U << BTRFS_ORDERED_COMPRESSED)));
1153
1154	/*
1155	 * The entire bio must be covered by the ordered extent, but we can't
1156	 * reduce the original extent to a zero length either.
1157	 */
1158	if (WARN_ON_ONCE(len >= ordered->num_bytes))
1159		return ERR_PTR(-EINVAL);
1160	/* We cannot split partially completed ordered extents. */
1161	if (ordered->bytes_left) {
1162		ASSERT(!(flags & ~BTRFS_ORDERED_TYPE_FLAGS));
1163		if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes))
1164			return ERR_PTR(-EINVAL);
1165	}
1166	/* We cannot split a compressed ordered extent. */
1167	if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes))
1168		return ERR_PTR(-EINVAL);
1169
1170	new = alloc_ordered_extent(inode, file_offset, len, len, disk_bytenr,
1171				   len, 0, flags, ordered->compress_type);
1172	if (IS_ERR(new))
1173		return new;
1174
1175	/* One ref for the tree. */
1176	refcount_inc(&new->refs);
1177
1178	spin_lock_irq(&root->ordered_extent_lock);
1179	spin_lock(&inode->ordered_tree_lock);
1180	/* Remove from tree once */
1181	node = &ordered->rb_node;
1182	rb_erase(node, &inode->ordered_tree);
1183	RB_CLEAR_NODE(node);
1184	if (inode->ordered_tree_last == node)
1185		inode->ordered_tree_last = NULL;
1186
1187	ordered->file_offset += len;
1188	ordered->disk_bytenr += len;
1189	ordered->num_bytes -= len;
1190	ordered->disk_num_bytes -= len;
1191	ordered->ram_bytes -= len;
1192
1193	if (test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags)) {
1194		ASSERT(ordered->bytes_left == 0);
1195		new->bytes_left = 0;
1196	} else {
1197		ordered->bytes_left -= len;
1198	}
1199
1200	if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags)) {
1201		if (ordered->truncated_len > len) {
1202			ordered->truncated_len -= len;
1203		} else {
1204			new->truncated_len = ordered->truncated_len;
1205			ordered->truncated_len = 0;
1206		}
1207	}
1208
1209	list_for_each_entry_safe(sum, tmpsum, &ordered->list, list) {
1210		if (offset == len)
1211			break;
1212		list_move_tail(&sum->list, &new->list);
1213		offset += sum->len;
1214	}
1215
1216	/* Re-insert the node */
1217	node = tree_insert(&inode->ordered_tree, ordered->file_offset,
1218			   &ordered->rb_node);
1219	if (node)
1220		btrfs_panic(fs_info, -EEXIST,
1221			"zoned: inconsistency in ordered tree at offset %llu",
1222			ordered->file_offset);
1223
1224	node = tree_insert(&inode->ordered_tree, new->file_offset, &new->rb_node);
1225	if (node)
1226		btrfs_panic(fs_info, -EEXIST,
1227			"zoned: inconsistency in ordered tree at offset %llu",
1228			new->file_offset);
1229	spin_unlock(&inode->ordered_tree_lock);
1230
1231	list_add_tail(&new->root_extent_list, &root->ordered_extents);
1232	root->nr_ordered_extents++;
1233	spin_unlock_irq(&root->ordered_extent_lock);
1234	return new;
1235}
1236
1237int __init ordered_data_init(void)
1238{
1239	btrfs_ordered_extent_cache = KMEM_CACHE(btrfs_ordered_extent, 0);
 
 
 
1240	if (!btrfs_ordered_extent_cache)
1241		return -ENOMEM;
1242
1243	return 0;
1244}
1245
1246void __cold ordered_data_exit(void)
1247{
1248	kmem_cache_destroy(btrfs_ordered_extent_cache);
1249}