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v6.2
   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 *tree_search(struct btrfs_ordered_inode_tree *tree,
 128					  u64 file_offset)
 129{
 130	struct rb_root *root = &tree->tree;
 131	struct rb_node *prev = NULL;
 132	struct rb_node *ret;
 133	struct btrfs_ordered_extent *entry;
 134
 135	if (tree->last) {
 136		entry = rb_entry(tree->last, struct btrfs_ordered_extent,
 137				 rb_node);
 138		if (in_range(file_offset, entry->file_offset, entry->num_bytes))
 139			return tree->last;
 140	}
 141	ret = __tree_search(root, file_offset, &prev);
 142	if (!ret)
 143		ret = prev;
 144	if (ret)
 145		tree->last = ret;
 146	return ret;
 147}
 148
 149/*
 150 * Add an ordered extent to the per-inode tree.
 151 *
 152 * @inode:           Inode that this extent is for.
 153 * @file_offset:     Logical offset in file where the extent starts.
 154 * @num_bytes:       Logical length of extent in file.
 155 * @ram_bytes:       Full length of unencoded data.
 156 * @disk_bytenr:     Offset of extent on disk.
 157 * @disk_num_bytes:  Size of extent on disk.
 158 * @offset:          Offset into unencoded data where file data starts.
 159 * @flags:           Flags specifying type of extent (1 << BTRFS_ORDERED_*).
 160 * @compress_type:   Compression algorithm used for data.
 161 *
 162 * Most of these parameters correspond to &struct btrfs_file_extent_item. The
 163 * tree is given a single reference on the ordered extent that was inserted.
 164 *
 165 * Return: 0 or -ENOMEM.
 166 */
 167int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
 168			     u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
 169			     u64 disk_num_bytes, u64 offset, unsigned flags,
 170			     int compress_type)
 171{
 172	struct btrfs_root *root = inode->root;
 173	struct btrfs_fs_info *fs_info = root->fs_info;
 174	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 175	struct rb_node *node;
 176	struct btrfs_ordered_extent *entry;
 177	int ret;
 178
 179	if (flags &
 180	    ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
 181		/* For nocow write, we can release the qgroup rsv right now */
 182		ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
 183		if (ret < 0)
 184			return ret;
 185		ret = 0;
 186	} else {
 187		/*
 188		 * The ordered extent has reserved qgroup space, release now
 189		 * and pass the reserved number for qgroup_record to free.
 190		 */
 191		ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes);
 192		if (ret < 0)
 193			return ret;
 194	}
 195	entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 196	if (!entry)
 197		return -ENOMEM;
 198
 199	entry->file_offset = file_offset;
 200	entry->num_bytes = num_bytes;
 201	entry->ram_bytes = ram_bytes;
 202	entry->disk_bytenr = disk_bytenr;
 
 203	entry->disk_num_bytes = disk_num_bytes;
 204	entry->offset = offset;
 205	entry->bytes_left = num_bytes;
 206	entry->inode = igrab(&inode->vfs_inode);
 207	entry->compress_type = compress_type;
 208	entry->truncated_len = (u64)-1;
 209	entry->qgroup_rsv = ret;
 210	entry->physical = (u64)-1;
 211
 212	ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
 213	entry->flags = flags;
 214
 215	percpu_counter_add_batch(&fs_info->ordered_bytes, num_bytes,
 216				 fs_info->delalloc_batch);
 
 
 
 217
 218	/* one ref for the tree */
 219	refcount_set(&entry->refs, 1);
 220	init_waitqueue_head(&entry->wait);
 221	INIT_LIST_HEAD(&entry->list);
 222	INIT_LIST_HEAD(&entry->log_list);
 223	INIT_LIST_HEAD(&entry->root_extent_list);
 224	INIT_LIST_HEAD(&entry->work_list);
 225	init_completion(&entry->completion);
 226
 227	trace_btrfs_ordered_extent_add(inode, entry);
 228
 229	spin_lock_irq(&tree->lock);
 230	node = tree_insert(&tree->tree, file_offset,
 231			   &entry->rb_node);
 232	if (node)
 233		btrfs_panic(fs_info, -EEXIST,
 234				"inconsistency in ordered tree at offset %llu",
 235				file_offset);
 236	spin_unlock_irq(&tree->lock);
 237
 238	spin_lock(&root->ordered_extent_lock);
 239	list_add_tail(&entry->root_extent_list,
 240		      &root->ordered_extents);
 241	root->nr_ordered_extents++;
 242	if (root->nr_ordered_extents == 1) {
 243		spin_lock(&fs_info->ordered_root_lock);
 244		BUG_ON(!list_empty(&root->ordered_root));
 245		list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 246		spin_unlock(&fs_info->ordered_root_lock);
 247	}
 248	spin_unlock(&root->ordered_extent_lock);
 249
 250	/*
 251	 * We don't need the count_max_extents here, we can assume that all of
 252	 * that work has been done at higher layers, so this is truly the
 253	 * smallest the extent is going to get.
 254	 */
 255	spin_lock(&inode->lock);
 256	btrfs_mod_outstanding_extents(inode, 1);
 257	spin_unlock(&inode->lock);
 258
 259	return 0;
 260}
 261
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 262/*
 263 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 264 * when an ordered extent is finished.  If the list covers more than one
 265 * ordered extent, it is split across multiples.
 266 */
 267void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 268			   struct btrfs_ordered_sum *sum)
 269{
 270	struct btrfs_ordered_inode_tree *tree;
 271
 272	tree = &BTRFS_I(entry->inode)->ordered_tree;
 273	spin_lock_irq(&tree->lock);
 274	list_add_tail(&sum->list, &entry->list);
 275	spin_unlock_irq(&tree->lock);
 276}
 277
 278static void finish_ordered_fn(struct btrfs_work *work)
 279{
 280	struct btrfs_ordered_extent *ordered_extent;
 281
 282	ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
 283	btrfs_finish_ordered_io(ordered_extent);
 284}
 285
 286/*
 287 * Mark all ordered extents io inside the specified range finished.
 288 *
 289 * @page:	 The involved page for the operation.
 290 *		 For uncompressed buffered IO, the page status also needs to be
 291 *		 updated to indicate whether the pending ordered io is finished.
 292 *		 Can be NULL for direct IO and compressed write.
 293 *		 For these cases, callers are ensured they won't execute the
 294 *		 endio function twice.
 295 *
 296 * This function is called for endio, thus the range must have ordered
 297 * extent(s) covering it.
 298 */
 299void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
 300				    struct page *page, u64 file_offset,
 301				    u64 num_bytes, bool uptodate)
 302{
 303	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 304	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 305	struct btrfs_workqueue *wq;
 306	struct rb_node *node;
 307	struct btrfs_ordered_extent *entry = NULL;
 
 308	unsigned long flags;
 309	u64 cur = file_offset;
 310
 311	if (btrfs_is_free_space_inode(inode))
 312		wq = fs_info->endio_freespace_worker;
 313	else
 314		wq = fs_info->endio_write_workers;
 315
 316	if (page)
 317		ASSERT(page->mapping && page_offset(page) <= file_offset &&
 318		       file_offset + num_bytes <= page_offset(page) + PAGE_SIZE);
 319
 320	spin_lock_irqsave(&tree->lock, flags);
 321	while (cur < file_offset + num_bytes) {
 322		u64 entry_end;
 323		u64 end;
 324		u32 len;
 325
 326		node = tree_search(tree, cur);
 327		/* No ordered extents at all */
 328		if (!node)
 329			break;
 330
 331		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 332		entry_end = entry->file_offset + entry->num_bytes;
 333		/*
 334		 * |<-- OE --->|  |
 335		 *		  cur
 336		 * Go to next OE.
 337		 */
 338		if (cur >= entry_end) {
 339			node = rb_next(node);
 340			/* No more ordered extents, exit */
 341			if (!node)
 342				break;
 343			entry = rb_entry(node, struct btrfs_ordered_extent,
 344					 rb_node);
 345
 346			/* Go to next ordered extent and continue */
 347			cur = entry->file_offset;
 348			continue;
 349		}
 350		/*
 351		 * |	|<--- OE --->|
 352		 * cur
 353		 * Go to the start of OE.
 354		 */
 355		if (cur < entry->file_offset) {
 356			cur = entry->file_offset;
 357			continue;
 358		}
 359
 360		/*
 361		 * Now we are definitely inside one ordered extent.
 362		 *
 363		 * |<--- OE --->|
 364		 *	|
 365		 *	cur
 366		 */
 367		end = min(entry->file_offset + entry->num_bytes,
 368			  file_offset + num_bytes) - 1;
 369		ASSERT(end + 1 - cur < U32_MAX);
 370		len = end + 1 - cur;
 371
 372		if (page) {
 373			/*
 374			 * Ordered (Private2) bit indicates whether we still
 375			 * have pending io unfinished for the ordered extent.
 376			 *
 377			 * If there's no such bit, we need to skip to next range.
 378			 */
 379			if (!btrfs_page_test_ordered(fs_info, page, cur, len)) {
 380				cur += len;
 381				continue;
 382			}
 383			btrfs_page_clear_ordered(fs_info, page, cur, len);
 384		}
 385
 386		/* Now we're fine to update the accounting */
 387		if (unlikely(len > entry->bytes_left)) {
 388			WARN_ON(1);
 389			btrfs_crit(fs_info,
 390"bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%u left=%llu",
 391				   inode->root->root_key.objectid,
 392				   btrfs_ino(inode),
 393				   entry->file_offset,
 394				   entry->num_bytes,
 395				   len, entry->bytes_left);
 396			entry->bytes_left = 0;
 397		} else {
 398			entry->bytes_left -= len;
 399		}
 400
 401		if (!uptodate)
 402			set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 403
 404		/*
 405		 * All the IO of the ordered extent is finished, we need to queue
 406		 * the finish_func to be executed.
 407		 */
 408		if (entry->bytes_left == 0) {
 409			set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 410			cond_wake_up(&entry->wait);
 411			refcount_inc(&entry->refs);
 412			trace_btrfs_ordered_extent_mark_finished(inode, entry);
 413			spin_unlock_irqrestore(&tree->lock, flags);
 414			btrfs_init_work(&entry->work, finish_ordered_fn, NULL, NULL);
 415			btrfs_queue_work(wq, &entry->work);
 416			spin_lock_irqsave(&tree->lock, flags);
 417		}
 418		cur += len;
 419	}
 420	spin_unlock_irqrestore(&tree->lock, flags);
 
 421}
 422
 423/*
 424 * Finish IO for one ordered extent across a given range.  The range can only
 425 * contain one ordered extent.
 
 
 426 *
 427 * @cached:	 The cached ordered extent. If not NULL, we can skip the tree
 428 *               search and use the ordered extent directly.
 429 * 		 Will be also used to store the finished ordered extent.
 430 * @file_offset: File offset for the finished IO
 431 * @io_size:	 Length of the finish IO range
 432 *
 433 * Return true if the ordered extent is finished in the range, and update
 434 * @cached.
 435 * Return false otherwise.
 436 *
 437 * NOTE: The range can NOT cross multiple ordered extents.
 438 * Thus caller should ensure the range doesn't cross ordered extents.
 439 */
 440bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 441				    struct btrfs_ordered_extent **cached,
 442				    u64 file_offset, u64 io_size)
 443{
 444	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 445	struct rb_node *node;
 446	struct btrfs_ordered_extent *entry = NULL;
 447	unsigned long flags;
 448	bool finished = false;
 449
 
 450	spin_lock_irqsave(&tree->lock, flags);
 451	if (cached && *cached) {
 452		entry = *cached;
 453		goto have_entry;
 454	}
 455
 456	node = tree_search(tree, file_offset);
 457	if (!node)
 
 458		goto out;
 
 459
 460	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 461have_entry:
 462	if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 
 463		goto out;
 
 464
 465	if (io_size > entry->bytes_left)
 466		btrfs_crit(inode->root->fs_info,
 467			   "bad ordered accounting left %llu size %llu",
 468		       entry->bytes_left, io_size);
 469
 470	entry->bytes_left -= io_size;
 
 
 471
 472	if (entry->bytes_left == 0) {
 473		/*
 474		 * Ensure only one caller can set the flag and finished_ret
 475		 * accordingly
 476		 */
 477		finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 478		/* test_and_set_bit implies a barrier */
 479		cond_wake_up_nomb(&entry->wait);
 
 
 480	}
 481out:
 482	if (finished && cached && entry) {
 483		*cached = entry;
 484		refcount_inc(&entry->refs);
 485		trace_btrfs_ordered_extent_dec_test_pending(inode, entry);
 486	}
 487	spin_unlock_irqrestore(&tree->lock, flags);
 488	return finished;
 489}
 490
 491/*
 492 * used to drop a reference on an ordered extent.  This will free
 493 * the extent if the last reference is dropped
 494 */
 495void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 496{
 497	struct list_head *cur;
 498	struct btrfs_ordered_sum *sum;
 499
 500	trace_btrfs_ordered_extent_put(BTRFS_I(entry->inode), entry);
 501
 502	if (refcount_dec_and_test(&entry->refs)) {
 503		ASSERT(list_empty(&entry->root_extent_list));
 504		ASSERT(list_empty(&entry->log_list));
 505		ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 506		if (entry->inode)
 507			btrfs_add_delayed_iput(BTRFS_I(entry->inode));
 508		while (!list_empty(&entry->list)) {
 509			cur = entry->list.next;
 510			sum = list_entry(cur, struct btrfs_ordered_sum, list);
 511			list_del(&sum->list);
 512			kvfree(sum);
 513		}
 514		kmem_cache_free(btrfs_ordered_extent_cache, entry);
 515	}
 516}
 517
 518/*
 519 * remove an ordered extent from the tree.  No references are dropped
 520 * and waiters are woken up.
 521 */
 522void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
 523				 struct btrfs_ordered_extent *entry)
 524{
 
 525	struct btrfs_ordered_inode_tree *tree;
 
 526	struct btrfs_root *root = btrfs_inode->root;
 527	struct btrfs_fs_info *fs_info = root->fs_info;
 528	struct rb_node *node;
 529	bool pending;
 530	bool freespace_inode;
 531
 532	/*
 533	 * If this is a free space inode the thread has not acquired the ordered
 534	 * extents lockdep map.
 535	 */
 536	freespace_inode = btrfs_is_free_space_inode(btrfs_inode);
 537
 538	btrfs_lockdep_acquire(fs_info, btrfs_trans_pending_ordered);
 539	/* This is paired with btrfs_add_ordered_extent. */
 540	spin_lock(&btrfs_inode->lock);
 541	btrfs_mod_outstanding_extents(btrfs_inode, -1);
 542	spin_unlock(&btrfs_inode->lock);
 543	if (root != fs_info->tree_root) {
 544		u64 release;
 545
 546		if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
 547			release = entry->disk_num_bytes;
 548		else
 549			release = entry->num_bytes;
 550		btrfs_delalloc_release_metadata(btrfs_inode, release, false);
 551	}
 552
 553	percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
 554				 fs_info->delalloc_batch);
 555
 556	tree = &btrfs_inode->ordered_tree;
 557	spin_lock_irq(&tree->lock);
 558	node = &entry->rb_node;
 559	rb_erase(node, &tree->tree);
 560	RB_CLEAR_NODE(node);
 561	if (tree->last == node)
 562		tree->last = NULL;
 563	set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 564	pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
 565	spin_unlock_irq(&tree->lock);
 566
 567	/*
 568	 * The current running transaction is waiting on us, we need to let it
 569	 * know that we're complete and wake it up.
 570	 */
 571	if (pending) {
 572		struct btrfs_transaction *trans;
 573
 574		/*
 575		 * The checks for trans are just a formality, it should be set,
 576		 * but if it isn't we don't want to deref/assert under the spin
 577		 * lock, so be nice and check if trans is set, but ASSERT() so
 578		 * if it isn't set a developer will notice.
 579		 */
 580		spin_lock(&fs_info->trans_lock);
 581		trans = fs_info->running_transaction;
 582		if (trans)
 583			refcount_inc(&trans->use_count);
 584		spin_unlock(&fs_info->trans_lock);
 585
 586		ASSERT(trans);
 587		if (trans) {
 588			if (atomic_dec_and_test(&trans->pending_ordered))
 589				wake_up(&trans->pending_wait);
 590			btrfs_put_transaction(trans);
 591		}
 592	}
 593
 594	btrfs_lockdep_release(fs_info, btrfs_trans_pending_ordered);
 595
 596	spin_lock(&root->ordered_extent_lock);
 597	list_del_init(&entry->root_extent_list);
 598	root->nr_ordered_extents--;
 599
 600	trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
 601
 602	if (!root->nr_ordered_extents) {
 603		spin_lock(&fs_info->ordered_root_lock);
 604		BUG_ON(list_empty(&root->ordered_root));
 605		list_del_init(&root->ordered_root);
 606		spin_unlock(&fs_info->ordered_root_lock);
 607	}
 608	spin_unlock(&root->ordered_extent_lock);
 609	wake_up(&entry->wait);
 610	if (!freespace_inode)
 611		btrfs_lockdep_release(fs_info, btrfs_ordered_extent);
 612}
 613
 614static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 615{
 616	struct btrfs_ordered_extent *ordered;
 617
 618	ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 619	btrfs_start_ordered_extent(ordered, 1);
 620	complete(&ordered->completion);
 621}
 622
 623/*
 624 * wait for all the ordered extents in a root.  This is done when balancing
 625 * space between drives.
 626 */
 627u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 628			       const u64 range_start, const u64 range_len)
 629{
 630	struct btrfs_fs_info *fs_info = root->fs_info;
 631	LIST_HEAD(splice);
 632	LIST_HEAD(skipped);
 633	LIST_HEAD(works);
 634	struct btrfs_ordered_extent *ordered, *next;
 635	u64 count = 0;
 636	const u64 range_end = range_start + range_len;
 637
 638	mutex_lock(&root->ordered_extent_mutex);
 639	spin_lock(&root->ordered_extent_lock);
 640	list_splice_init(&root->ordered_extents, &splice);
 641	while (!list_empty(&splice) && nr) {
 642		ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 643					   root_extent_list);
 644
 645		if (range_end <= ordered->disk_bytenr ||
 646		    ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
 647			list_move_tail(&ordered->root_extent_list, &skipped);
 648			cond_resched_lock(&root->ordered_extent_lock);
 649			continue;
 650		}
 651
 652		list_move_tail(&ordered->root_extent_list,
 653			       &root->ordered_extents);
 654		refcount_inc(&ordered->refs);
 655		spin_unlock(&root->ordered_extent_lock);
 656
 657		btrfs_init_work(&ordered->flush_work,
 658				btrfs_run_ordered_extent_work, NULL, NULL);
 659		list_add_tail(&ordered->work_list, &works);
 660		btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 661
 662		cond_resched();
 663		spin_lock(&root->ordered_extent_lock);
 664		if (nr != U64_MAX)
 665			nr--;
 666		count++;
 667	}
 668	list_splice_tail(&skipped, &root->ordered_extents);
 669	list_splice_tail(&splice, &root->ordered_extents);
 670	spin_unlock(&root->ordered_extent_lock);
 671
 672	list_for_each_entry_safe(ordered, next, &works, work_list) {
 673		list_del_init(&ordered->work_list);
 674		wait_for_completion(&ordered->completion);
 675		btrfs_put_ordered_extent(ordered);
 676		cond_resched();
 677	}
 678	mutex_unlock(&root->ordered_extent_mutex);
 679
 680	return count;
 681}
 682
 683void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 684			     const u64 range_start, const u64 range_len)
 685{
 686	struct btrfs_root *root;
 687	struct list_head splice;
 688	u64 done;
 689
 690	INIT_LIST_HEAD(&splice);
 691
 692	mutex_lock(&fs_info->ordered_operations_mutex);
 693	spin_lock(&fs_info->ordered_root_lock);
 694	list_splice_init(&fs_info->ordered_roots, &splice);
 695	while (!list_empty(&splice) && nr) {
 696		root = list_first_entry(&splice, struct btrfs_root,
 697					ordered_root);
 698		root = btrfs_grab_root(root);
 699		BUG_ON(!root);
 700		list_move_tail(&root->ordered_root,
 701			       &fs_info->ordered_roots);
 702		spin_unlock(&fs_info->ordered_root_lock);
 703
 704		done = btrfs_wait_ordered_extents(root, nr,
 705						  range_start, range_len);
 706		btrfs_put_root(root);
 707
 708		spin_lock(&fs_info->ordered_root_lock);
 709		if (nr != U64_MAX) {
 710			nr -= done;
 711		}
 712	}
 713	list_splice_tail(&splice, &fs_info->ordered_roots);
 714	spin_unlock(&fs_info->ordered_root_lock);
 715	mutex_unlock(&fs_info->ordered_operations_mutex);
 716}
 717
 718/*
 719 * Used to start IO or wait for a given ordered extent to finish.
 720 *
 721 * If wait is one, this effectively waits on page writeback for all the pages
 722 * in the extent, and it waits on the io completion code to insert
 723 * metadata into the btree corresponding to the extent
 724 */
 725void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry, int wait)
 
 
 726{
 727	u64 start = entry->file_offset;
 728	u64 end = start + entry->num_bytes - 1;
 729	struct btrfs_inode *inode = BTRFS_I(entry->inode);
 730	bool freespace_inode;
 731
 732	trace_btrfs_ordered_extent_start(inode, entry);
 733
 734	/*
 735	 * If this is a free space inode do not take the ordered extents lockdep
 736	 * map.
 737	 */
 738	freespace_inode = btrfs_is_free_space_inode(inode);
 739
 740	/*
 741	 * pages in the range can be dirty, clean or writeback.  We
 742	 * start IO on any dirty ones so the wait doesn't stall waiting
 743	 * for the flusher thread to find them
 744	 */
 745	if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 746		filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
 747	if (wait) {
 748		if (!freespace_inode)
 749			btrfs_might_wait_for_event(inode->root->fs_info, btrfs_ordered_extent);
 750		wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 751						 &entry->flags));
 752	}
 753}
 754
 755/*
 756 * Used to wait on ordered extents across a large range of bytes.
 757 */
 758int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 759{
 760	int ret = 0;
 761	int ret_wb = 0;
 762	u64 end;
 763	u64 orig_end;
 764	struct btrfs_ordered_extent *ordered;
 765
 766	if (start + len < start) {
 767		orig_end = OFFSET_MAX;
 768	} else {
 769		orig_end = start + len - 1;
 770		if (orig_end > OFFSET_MAX)
 771			orig_end = OFFSET_MAX;
 772	}
 773
 774	/* start IO across the range first to instantiate any delalloc
 775	 * extents
 776	 */
 777	ret = btrfs_fdatawrite_range(inode, start, orig_end);
 778	if (ret)
 779		return ret;
 780
 781	/*
 782	 * If we have a writeback error don't return immediately. Wait first
 783	 * for any ordered extents that haven't completed yet. This is to make
 784	 * sure no one can dirty the same page ranges and call writepages()
 785	 * before the ordered extents complete - to avoid failures (-EEXIST)
 786	 * when adding the new ordered extents to the ordered tree.
 787	 */
 788	ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 789
 790	end = orig_end;
 791	while (1) {
 792		ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode), end);
 793		if (!ordered)
 794			break;
 795		if (ordered->file_offset > orig_end) {
 796			btrfs_put_ordered_extent(ordered);
 797			break;
 798		}
 799		if (ordered->file_offset + ordered->num_bytes <= start) {
 800			btrfs_put_ordered_extent(ordered);
 801			break;
 802		}
 803		btrfs_start_ordered_extent(ordered, 1);
 804		end = ordered->file_offset;
 805		/*
 806		 * If the ordered extent had an error save the error but don't
 807		 * exit without waiting first for all other ordered extents in
 808		 * the range to complete.
 809		 */
 810		if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 811			ret = -EIO;
 812		btrfs_put_ordered_extent(ordered);
 813		if (end == 0 || end == start)
 814			break;
 815		end--;
 816	}
 817	return ret_wb ? ret_wb : ret;
 818}
 819
 820/*
 821 * find an ordered extent corresponding to file_offset.  return NULL if
 822 * nothing is found, otherwise take a reference on the extent and return it
 823 */
 824struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
 825							 u64 file_offset)
 826{
 827	struct btrfs_ordered_inode_tree *tree;
 828	struct rb_node *node;
 829	struct btrfs_ordered_extent *entry = NULL;
 830	unsigned long flags;
 831
 832	tree = &inode->ordered_tree;
 833	spin_lock_irqsave(&tree->lock, flags);
 834	node = tree_search(tree, file_offset);
 835	if (!node)
 836		goto out;
 837
 838	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 839	if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 840		entry = NULL;
 841	if (entry) {
 842		refcount_inc(&entry->refs);
 843		trace_btrfs_ordered_extent_lookup(inode, entry);
 844	}
 845out:
 846	spin_unlock_irqrestore(&tree->lock, flags);
 847	return entry;
 848}
 849
 850/* Since the DIO code tries to lock a wide area we need to look for any ordered
 851 * extents that exist in the range, rather than just the start of the range.
 852 */
 853struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 854		struct btrfs_inode *inode, u64 file_offset, u64 len)
 855{
 856	struct btrfs_ordered_inode_tree *tree;
 857	struct rb_node *node;
 858	struct btrfs_ordered_extent *entry = NULL;
 859
 860	tree = &inode->ordered_tree;
 861	spin_lock_irq(&tree->lock);
 862	node = tree_search(tree, file_offset);
 863	if (!node) {
 864		node = tree_search(tree, file_offset + len);
 865		if (!node)
 866			goto out;
 867	}
 868
 869	while (1) {
 870		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 871		if (range_overlaps(entry, file_offset, len))
 872			break;
 873
 874		if (entry->file_offset >= file_offset + len) {
 875			entry = NULL;
 876			break;
 877		}
 878		entry = NULL;
 879		node = rb_next(node);
 880		if (!node)
 881			break;
 882	}
 883out:
 884	if (entry) {
 885		refcount_inc(&entry->refs);
 886		trace_btrfs_ordered_extent_lookup_range(inode, entry);
 887	}
 888	spin_unlock_irq(&tree->lock);
 889	return entry;
 890}
 891
 892/*
 893 * Adds all ordered extents to the given list. The list ends up sorted by the
 894 * file_offset of the ordered extents.
 895 */
 896void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
 897					   struct list_head *list)
 898{
 899	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 900	struct rb_node *n;
 901
 902	ASSERT(inode_is_locked(&inode->vfs_inode));
 903
 904	spin_lock_irq(&tree->lock);
 905	for (n = rb_first(&tree->tree); n; n = rb_next(n)) {
 906		struct btrfs_ordered_extent *ordered;
 907
 908		ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 909
 910		if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 911			continue;
 912
 913		ASSERT(list_empty(&ordered->log_list));
 914		list_add_tail(&ordered->log_list, list);
 915		refcount_inc(&ordered->refs);
 916		trace_btrfs_ordered_extent_lookup_for_logging(inode, ordered);
 917	}
 918	spin_unlock_irq(&tree->lock);
 919}
 920
 921/*
 922 * lookup and return any extent before 'file_offset'.  NULL is returned
 923 * if none is found
 924 */
 925struct btrfs_ordered_extent *
 926btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
 927{
 928	struct btrfs_ordered_inode_tree *tree;
 929	struct rb_node *node;
 930	struct btrfs_ordered_extent *entry = NULL;
 931
 932	tree = &inode->ordered_tree;
 933	spin_lock_irq(&tree->lock);
 934	node = tree_search(tree, file_offset);
 935	if (!node)
 936		goto out;
 937
 938	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 939	refcount_inc(&entry->refs);
 940	trace_btrfs_ordered_extent_lookup_first(inode, entry);
 941out:
 942	spin_unlock_irq(&tree->lock);
 943	return entry;
 944}
 945
 946/*
 947 * Lookup the first ordered extent that overlaps the range
 948 * [@file_offset, @file_offset + @len).
 949 *
 950 * The difference between this and btrfs_lookup_first_ordered_extent() is
 951 * that this one won't return any ordered extent that does not overlap the range.
 952 * And the difference against btrfs_lookup_ordered_extent() is, this function
 953 * ensures the first ordered extent gets returned.
 954 */
 955struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
 956			struct btrfs_inode *inode, u64 file_offset, u64 len)
 957{
 958	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 959	struct rb_node *node;
 960	struct rb_node *cur;
 961	struct rb_node *prev;
 962	struct rb_node *next;
 963	struct btrfs_ordered_extent *entry = NULL;
 
 
 
 964
 965	spin_lock_irq(&tree->lock);
 966	node = tree->tree.rb_node;
 967	/*
 968	 * Here we don't want to use tree_search() which will use tree->last
 969	 * and screw up the search order.
 970	 * And __tree_search() can't return the adjacent ordered extents
 971	 * either, thus here we do our own search.
 972	 */
 973	while (node) {
 974		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 975
 976		if (file_offset < entry->file_offset) {
 977			node = node->rb_left;
 978		} else if (file_offset >= entry_end(entry)) {
 979			node = node->rb_right;
 980		} else {
 981			/*
 982			 * Direct hit, got an ordered extent that starts at
 983			 * @file_offset
 984			 */
 985			goto out;
 
 
 
 
 
 
 986		}
 987	}
 988	if (!entry) {
 989		/* Empty tree */
 990		goto out;
 991	}
 992
 993	cur = &entry->rb_node;
 994	/* We got an entry around @file_offset, check adjacent entries */
 995	if (entry->file_offset < file_offset) {
 996		prev = cur;
 997		next = rb_next(cur);
 998	} else {
 999		prev = rb_prev(cur);
1000		next = cur;
1001	}
1002	if (prev) {
1003		entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
1004		if (range_overlaps(entry, file_offset, len))
1005			goto out;
1006	}
1007	if (next) {
1008		entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
1009		if (range_overlaps(entry, file_offset, len))
1010			goto out;
1011	}
1012	/* No ordered extent in the range */
1013	entry = NULL;
1014out:
1015	if (entry) {
1016		refcount_inc(&entry->refs);
1017		trace_btrfs_ordered_extent_lookup_first_range(inode, entry);
1018	}
1019
1020	spin_unlock_irq(&tree->lock);
1021	return entry;
 
1022}
1023
1024/*
1025 * Lock the passed range and ensures all pending ordered extents in it are run
1026 * to completion.
1027 *
1028 * @inode:        Inode whose ordered tree is to be searched
1029 * @start:        Beginning of range to flush
1030 * @end:          Last byte of range to lock
1031 * @cached_state: If passed, will return the extent state responsible for the
1032 *                locked range. It's the caller's responsibility to free the
1033 *                cached state.
1034 *
1035 * Always return with the given range locked, ensuring after it's called no
1036 * order extent can be pending.
1037 */
1038void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
1039					u64 end,
1040					struct extent_state **cached_state)
1041{
1042	struct btrfs_ordered_extent *ordered;
1043	struct extent_state *cache = NULL;
1044	struct extent_state **cachedp = &cache;
1045
1046	if (cached_state)
1047		cachedp = cached_state;
1048
1049	while (1) {
1050		lock_extent(&inode->io_tree, start, end, cachedp);
1051		ordered = btrfs_lookup_ordered_range(inode, start,
1052						     end - start + 1);
1053		if (!ordered) {
1054			/*
1055			 * If no external cached_state has been passed then
1056			 * decrement the extra ref taken for cachedp since we
1057			 * aren't exposing it outside of this function
1058			 */
1059			if (!cached_state)
1060				refcount_dec(&cache->refs);
1061			break;
1062		}
1063		unlock_extent(&inode->io_tree, start, end, cachedp);
1064		btrfs_start_ordered_extent(ordered, 1);
1065		btrfs_put_ordered_extent(ordered);
1066	}
1067}
1068
1069/*
1070 * Lock the passed range and ensure all pending ordered extents in it are run
1071 * to completion in nowait mode.
1072 *
1073 * Return true if btrfs_lock_ordered_range does not return any extents,
1074 * otherwise false.
1075 */
1076bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
1077				  struct extent_state **cached_state)
1078{
1079	struct btrfs_ordered_extent *ordered;
1080
1081	if (!try_lock_extent(&inode->io_tree, start, end, cached_state))
1082		return false;
1083
1084	ordered = btrfs_lookup_ordered_range(inode, start, end - start + 1);
1085	if (!ordered)
1086		return true;
1087
1088	btrfs_put_ordered_extent(ordered);
1089	unlock_extent(&inode->io_tree, start, end, cached_state);
1090
1091	return false;
1092}
1093
1094
1095static int clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
1096				u64 len)
1097{
1098	struct inode *inode = ordered->inode;
1099	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1100	u64 file_offset = ordered->file_offset + pos;
1101	u64 disk_bytenr = ordered->disk_bytenr + pos;
1102	unsigned long flags = ordered->flags & BTRFS_ORDERED_TYPE_FLAGS;
1103
1104	/*
1105	 * The splitting extent is already counted and will be added again in
1106	 * btrfs_add_ordered_extent_*(). Subtract len to avoid double counting.
1107	 */
1108	percpu_counter_add_batch(&fs_info->ordered_bytes, -len,
1109				 fs_info->delalloc_batch);
1110	WARN_ON_ONCE(flags & (1 << BTRFS_ORDERED_COMPRESSED));
1111	return btrfs_add_ordered_extent(BTRFS_I(inode), file_offset, len, len,
1112					disk_bytenr, len, 0, flags,
1113					ordered->compress_type);
1114}
1115
1116int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pre,
1117				u64 post)
1118{
1119	struct inode *inode = ordered->inode;
1120	struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1121	struct rb_node *node;
1122	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1123	int ret = 0;
1124
1125	trace_btrfs_ordered_extent_split(BTRFS_I(inode), ordered);
1126
1127	spin_lock_irq(&tree->lock);
1128	/* Remove from tree once */
1129	node = &ordered->rb_node;
1130	rb_erase(node, &tree->tree);
1131	RB_CLEAR_NODE(node);
1132	if (tree->last == node)
1133		tree->last = NULL;
1134
1135	ordered->file_offset += pre;
1136	ordered->disk_bytenr += pre;
1137	ordered->num_bytes -= (pre + post);
1138	ordered->disk_num_bytes -= (pre + post);
1139	ordered->bytes_left -= (pre + post);
1140
1141	/* Re-insert the node */
1142	node = tree_insert(&tree->tree, ordered->file_offset, &ordered->rb_node);
1143	if (node)
1144		btrfs_panic(fs_info, -EEXIST,
1145			"zoned: inconsistency in ordered tree at offset %llu",
1146			    ordered->file_offset);
1147
1148	spin_unlock_irq(&tree->lock);
1149
1150	if (pre)
1151		ret = clone_ordered_extent(ordered, 0, pre);
1152	if (ret == 0 && post)
1153		ret = clone_ordered_extent(ordered, pre + ordered->disk_num_bytes,
1154					   post);
1155
1156	return ret;
1157}
1158
1159int __init ordered_data_init(void)
1160{
1161	btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1162				     sizeof(struct btrfs_ordered_extent), 0,
1163				     SLAB_MEM_SPREAD,
1164				     NULL);
1165	if (!btrfs_ordered_extent_cache)
1166		return -ENOMEM;
1167
1168	return 0;
1169}
1170
1171void __cold ordered_data_exit(void)
1172{
1173	kmem_cache_destroy(btrfs_ordered_extent_cache);
1174}
v5.9
  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
 20static struct kmem_cache *btrfs_ordered_extent_cache;
 21
 22static u64 entry_end(struct btrfs_ordered_extent *entry)
 23{
 24	if (entry->file_offset + entry->num_bytes < entry->file_offset)
 25		return (u64)-1;
 26	return entry->file_offset + entry->num_bytes;
 27}
 28
 29/* returns NULL if the insertion worked, or it returns the node it did find
 30 * in the tree
 31 */
 32static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
 33				   struct rb_node *node)
 34{
 35	struct rb_node **p = &root->rb_node;
 36	struct rb_node *parent = NULL;
 37	struct btrfs_ordered_extent *entry;
 38
 39	while (*p) {
 40		parent = *p;
 41		entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
 42
 43		if (file_offset < entry->file_offset)
 44			p = &(*p)->rb_left;
 45		else if (file_offset >= entry_end(entry))
 46			p = &(*p)->rb_right;
 47		else
 48			return parent;
 49	}
 50
 51	rb_link_node(node, parent, p);
 52	rb_insert_color(node, root);
 53	return NULL;
 54}
 55
 56/*
 57 * look for a given offset in the tree, and if it can't be found return the
 58 * first lesser offset
 59 */
 60static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
 61				     struct rb_node **prev_ret)
 62{
 63	struct rb_node *n = root->rb_node;
 64	struct rb_node *prev = NULL;
 65	struct rb_node *test;
 66	struct btrfs_ordered_extent *entry;
 67	struct btrfs_ordered_extent *prev_entry = NULL;
 68
 69	while (n) {
 70		entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 71		prev = n;
 72		prev_entry = entry;
 73
 74		if (file_offset < entry->file_offset)
 75			n = n->rb_left;
 76		else if (file_offset >= entry_end(entry))
 77			n = n->rb_right;
 78		else
 79			return n;
 80	}
 81	if (!prev_ret)
 82		return NULL;
 83
 84	while (prev && file_offset >= entry_end(prev_entry)) {
 85		test = rb_next(prev);
 86		if (!test)
 87			break;
 88		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 89				      rb_node);
 90		if (file_offset < entry_end(prev_entry))
 91			break;
 92
 93		prev = test;
 94	}
 95	if (prev)
 96		prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
 97				      rb_node);
 98	while (prev && file_offset < entry_end(prev_entry)) {
 99		test = rb_prev(prev);
100		if (!test)
101			break;
102		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
103				      rb_node);
104		prev = test;
105	}
106	*prev_ret = prev;
107	return NULL;
108}
109
110/*
111 * helper to check if a given offset is inside a given entry
112 */
113static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
114{
115	if (file_offset < entry->file_offset ||
116	    entry->file_offset + entry->num_bytes <= file_offset)
117		return 0;
118	return 1;
119}
120
121static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
122			  u64 len)
123{
124	if (file_offset + len <= entry->file_offset ||
125	    entry->file_offset + entry->num_bytes <= file_offset)
126		return 0;
127	return 1;
128}
129
130/*
131 * look find the first ordered struct that has this offset, otherwise
132 * the first one less than this offset
133 */
134static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
135					  u64 file_offset)
136{
137	struct rb_root *root = &tree->tree;
138	struct rb_node *prev = NULL;
139	struct rb_node *ret;
140	struct btrfs_ordered_extent *entry;
141
142	if (tree->last) {
143		entry = rb_entry(tree->last, struct btrfs_ordered_extent,
144				 rb_node);
145		if (offset_in_entry(entry, file_offset))
146			return tree->last;
147	}
148	ret = __tree_search(root, file_offset, &prev);
149	if (!ret)
150		ret = prev;
151	if (ret)
152		tree->last = ret;
153	return ret;
154}
155
156/*
157 * Allocate and add a new ordered_extent into the per-inode tree.
 
 
 
 
 
 
 
 
 
 
158 *
159 * The tree is given a single reference on the ordered extent that was
160 * inserted.
 
 
161 */
162static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
163				      u64 disk_bytenr, u64 num_bytes,
164				      u64 disk_num_bytes, int type, int dio,
165				      int compress_type)
166{
167	struct btrfs_root *root = inode->root;
168	struct btrfs_fs_info *fs_info = root->fs_info;
169	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
170	struct rb_node *node;
171	struct btrfs_ordered_extent *entry;
172	int ret;
173
174	if (type == BTRFS_ORDERED_NOCOW || type == BTRFS_ORDERED_PREALLOC) {
 
175		/* For nocow write, we can release the qgroup rsv right now */
176		ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
177		if (ret < 0)
178			return ret;
179		ret = 0;
180	} else {
181		/*
182		 * The ordered extent has reserved qgroup space, release now
183		 * and pass the reserved number for qgroup_record to free.
184		 */
185		ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes);
186		if (ret < 0)
187			return ret;
188	}
189	entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
190	if (!entry)
191		return -ENOMEM;
192
193	entry->file_offset = file_offset;
 
 
194	entry->disk_bytenr = disk_bytenr;
195	entry->num_bytes = num_bytes;
196	entry->disk_num_bytes = disk_num_bytes;
 
197	entry->bytes_left = num_bytes;
198	entry->inode = igrab(&inode->vfs_inode);
199	entry->compress_type = compress_type;
200	entry->truncated_len = (u64)-1;
201	entry->qgroup_rsv = ret;
202	if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
203		set_bit(type, &entry->flags);
 
 
204
205	if (dio) {
206		percpu_counter_add_batch(&fs_info->dio_bytes, num_bytes,
207					 fs_info->delalloc_batch);
208		set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
209	}
210
211	/* one ref for the tree */
212	refcount_set(&entry->refs, 1);
213	init_waitqueue_head(&entry->wait);
214	INIT_LIST_HEAD(&entry->list);
 
215	INIT_LIST_HEAD(&entry->root_extent_list);
216	INIT_LIST_HEAD(&entry->work_list);
217	init_completion(&entry->completion);
218
219	trace_btrfs_ordered_extent_add(&inode->vfs_inode, entry);
220
221	spin_lock_irq(&tree->lock);
222	node = tree_insert(&tree->tree, file_offset,
223			   &entry->rb_node);
224	if (node)
225		btrfs_panic(fs_info, -EEXIST,
226				"inconsistency in ordered tree at offset %llu",
227				file_offset);
228	spin_unlock_irq(&tree->lock);
229
230	spin_lock(&root->ordered_extent_lock);
231	list_add_tail(&entry->root_extent_list,
232		      &root->ordered_extents);
233	root->nr_ordered_extents++;
234	if (root->nr_ordered_extents == 1) {
235		spin_lock(&fs_info->ordered_root_lock);
236		BUG_ON(!list_empty(&root->ordered_root));
237		list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
238		spin_unlock(&fs_info->ordered_root_lock);
239	}
240	spin_unlock(&root->ordered_extent_lock);
241
242	/*
243	 * We don't need the count_max_extents here, we can assume that all of
244	 * that work has been done at higher layers, so this is truly the
245	 * smallest the extent is going to get.
246	 */
247	spin_lock(&inode->lock);
248	btrfs_mod_outstanding_extents(inode, 1);
249	spin_unlock(&inode->lock);
250
251	return 0;
252}
253
254int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
255			     u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
256			     int type)
257{
258	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
259					  num_bytes, disk_num_bytes, type, 0,
260					  BTRFS_COMPRESS_NONE);
261}
262
263int btrfs_add_ordered_extent_dio(struct btrfs_inode *inode, u64 file_offset,
264				 u64 disk_bytenr, u64 num_bytes,
265				 u64 disk_num_bytes, int type)
266{
267	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
268					  num_bytes, disk_num_bytes, type, 1,
269					  BTRFS_COMPRESS_NONE);
270}
271
272int btrfs_add_ordered_extent_compress(struct btrfs_inode *inode, u64 file_offset,
273				      u64 disk_bytenr, u64 num_bytes,
274				      u64 disk_num_bytes, int type,
275				      int compress_type)
276{
277	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
278					  num_bytes, disk_num_bytes, type, 0,
279					  compress_type);
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_ordered_inode_tree *tree;
291
292	tree = &BTRFS_I(entry->inode)->ordered_tree;
293	spin_lock_irq(&tree->lock);
294	list_add_tail(&sum->list, &entry->list);
295	spin_unlock_irq(&tree->lock);
296}
297
 
 
 
 
 
 
 
 
298/*
299 * this is used to account for finished IO across a given range
300 * of the file.  The IO may span ordered extents.  If
301 * a given ordered_extent is completely done, 1 is returned, otherwise
302 * 0.
303 *
304 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
305 * to make sure this function only returns 1 once for a given ordered extent.
306 *
307 * file_offset is updated to one byte past the range that is recorded as
308 * complete.  This allows you to walk forward in the file.
309 */
310int btrfs_dec_test_first_ordered_pending(struct btrfs_inode *inode,
311				   struct btrfs_ordered_extent **cached,
312				   u64 *file_offset, u64 io_size, int uptodate)
 
313{
 
314	struct btrfs_fs_info *fs_info = inode->root->fs_info;
315	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
316	struct rb_node *node;
317	struct btrfs_ordered_extent *entry = NULL;
318	int ret;
319	unsigned long flags;
320	u64 dec_end;
321	u64 dec_start;
322	u64 to_dec;
 
 
 
 
 
 
 
323
324	spin_lock_irqsave(&tree->lock, flags);
325	node = tree_search(tree, *file_offset);
326	if (!node) {
327		ret = 1;
328		goto out;
329	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
330
331	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
332	if (!offset_in_entry(entry, *file_offset)) {
333		ret = 1;
334		goto out;
335	}
 
 
 
 
 
 
 
 
 
336
337	dec_start = max(*file_offset, entry->file_offset);
338	dec_end = min(*file_offset + io_size,
339		      entry->file_offset + entry->num_bytes);
340	*file_offset = dec_end;
341	if (dec_start > dec_end) {
342		btrfs_crit(fs_info, "bad ordering dec_start %llu end %llu",
343			   dec_start, dec_end);
344	}
345	to_dec = dec_end - dec_start;
346	if (to_dec > entry->bytes_left) {
347		btrfs_crit(fs_info,
348			   "bad ordered accounting left %llu size %llu",
349			   entry->bytes_left, to_dec);
350	}
351	entry->bytes_left -= to_dec;
352	if (!uptodate)
353		set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
354
355	if (entry->bytes_left == 0) {
356		ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
357		/* test_and_set_bit implies a barrier */
358		cond_wake_up_nomb(&entry->wait);
359	} else {
360		ret = 1;
361	}
362out:
363	if (!ret && cached && entry) {
364		*cached = entry;
365		refcount_inc(&entry->refs);
 
 
 
 
366	}
367	spin_unlock_irqrestore(&tree->lock, flags);
368	return ret == 0;
369}
370
371/*
372 * this is used to account for finished IO across a given range
373 * of the file.  The IO should not span ordered extents.  If
374 * a given ordered_extent is completely done, 1 is returned, otherwise
375 * 0.
376 *
377 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
378 * to make sure this function only returns 1 once for a given ordered extent.
 
 
 
 
 
 
 
 
 
 
379 */
380int btrfs_dec_test_ordered_pending(struct inode *inode,
381				   struct btrfs_ordered_extent **cached,
382				   u64 file_offset, u64 io_size, int uptodate)
383{
384	struct btrfs_ordered_inode_tree *tree;
385	struct rb_node *node;
386	struct btrfs_ordered_extent *entry = NULL;
387	unsigned long flags;
388	int ret;
389
390	tree = &BTRFS_I(inode)->ordered_tree;
391	spin_lock_irqsave(&tree->lock, flags);
392	if (cached && *cached) {
393		entry = *cached;
394		goto have_entry;
395	}
396
397	node = tree_search(tree, file_offset);
398	if (!node) {
399		ret = 1;
400		goto out;
401	}
402
403	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
404have_entry:
405	if (!offset_in_entry(entry, file_offset)) {
406		ret = 1;
407		goto out;
408	}
409
410	if (io_size > entry->bytes_left) {
411		btrfs_crit(BTRFS_I(inode)->root->fs_info,
412			   "bad ordered accounting left %llu size %llu",
413		       entry->bytes_left, io_size);
414	}
415	entry->bytes_left -= io_size;
416	if (!uptodate)
417		set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
418
419	if (entry->bytes_left == 0) {
420		ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 
 
 
 
421		/* test_and_set_bit implies a barrier */
422		cond_wake_up_nomb(&entry->wait);
423	} else {
424		ret = 1;
425	}
426out:
427	if (!ret && cached && entry) {
428		*cached = entry;
429		refcount_inc(&entry->refs);
 
430	}
431	spin_unlock_irqrestore(&tree->lock, flags);
432	return ret == 0;
433}
434
435/*
436 * used to drop a reference on an ordered extent.  This will free
437 * the extent if the last reference is dropped
438 */
439void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
440{
441	struct list_head *cur;
442	struct btrfs_ordered_sum *sum;
443
444	trace_btrfs_ordered_extent_put(entry->inode, entry);
445
446	if (refcount_dec_and_test(&entry->refs)) {
447		ASSERT(list_empty(&entry->root_extent_list));
 
448		ASSERT(RB_EMPTY_NODE(&entry->rb_node));
449		if (entry->inode)
450			btrfs_add_delayed_iput(entry->inode);
451		while (!list_empty(&entry->list)) {
452			cur = entry->list.next;
453			sum = list_entry(cur, struct btrfs_ordered_sum, list);
454			list_del(&sum->list);
455			kvfree(sum);
456		}
457		kmem_cache_free(btrfs_ordered_extent_cache, entry);
458	}
459}
460
461/*
462 * remove an ordered extent from the tree.  No references are dropped
463 * and waiters are woken up.
464 */
465void btrfs_remove_ordered_extent(struct inode *inode,
466				 struct btrfs_ordered_extent *entry)
467{
468	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
469	struct btrfs_ordered_inode_tree *tree;
470	struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
471	struct btrfs_root *root = btrfs_inode->root;
 
472	struct rb_node *node;
 
 
473
 
 
 
 
 
 
 
474	/* This is paired with btrfs_add_ordered_extent. */
475	spin_lock(&btrfs_inode->lock);
476	btrfs_mod_outstanding_extents(btrfs_inode, -1);
477	spin_unlock(&btrfs_inode->lock);
478	if (root != fs_info->tree_root)
479		btrfs_delalloc_release_metadata(btrfs_inode, entry->num_bytes,
480						false);
481
482	if (test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
483		percpu_counter_add_batch(&fs_info->dio_bytes, -entry->num_bytes,
484					 fs_info->delalloc_batch);
 
 
 
 
 
485
486	tree = &btrfs_inode->ordered_tree;
487	spin_lock_irq(&tree->lock);
488	node = &entry->rb_node;
489	rb_erase(node, &tree->tree);
490	RB_CLEAR_NODE(node);
491	if (tree->last == node)
492		tree->last = NULL;
493	set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 
494	spin_unlock_irq(&tree->lock);
495
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
496	spin_lock(&root->ordered_extent_lock);
497	list_del_init(&entry->root_extent_list);
498	root->nr_ordered_extents--;
499
500	trace_btrfs_ordered_extent_remove(inode, entry);
501
502	if (!root->nr_ordered_extents) {
503		spin_lock(&fs_info->ordered_root_lock);
504		BUG_ON(list_empty(&root->ordered_root));
505		list_del_init(&root->ordered_root);
506		spin_unlock(&fs_info->ordered_root_lock);
507	}
508	spin_unlock(&root->ordered_extent_lock);
509	wake_up(&entry->wait);
 
 
510}
511
512static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
513{
514	struct btrfs_ordered_extent *ordered;
515
516	ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
517	btrfs_start_ordered_extent(ordered->inode, ordered, 1);
518	complete(&ordered->completion);
519}
520
521/*
522 * wait for all the ordered extents in a root.  This is done when balancing
523 * space between drives.
524 */
525u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
526			       const u64 range_start, const u64 range_len)
527{
528	struct btrfs_fs_info *fs_info = root->fs_info;
529	LIST_HEAD(splice);
530	LIST_HEAD(skipped);
531	LIST_HEAD(works);
532	struct btrfs_ordered_extent *ordered, *next;
533	u64 count = 0;
534	const u64 range_end = range_start + range_len;
535
536	mutex_lock(&root->ordered_extent_mutex);
537	spin_lock(&root->ordered_extent_lock);
538	list_splice_init(&root->ordered_extents, &splice);
539	while (!list_empty(&splice) && nr) {
540		ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
541					   root_extent_list);
542
543		if (range_end <= ordered->disk_bytenr ||
544		    ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
545			list_move_tail(&ordered->root_extent_list, &skipped);
546			cond_resched_lock(&root->ordered_extent_lock);
547			continue;
548		}
549
550		list_move_tail(&ordered->root_extent_list,
551			       &root->ordered_extents);
552		refcount_inc(&ordered->refs);
553		spin_unlock(&root->ordered_extent_lock);
554
555		btrfs_init_work(&ordered->flush_work,
556				btrfs_run_ordered_extent_work, NULL, NULL);
557		list_add_tail(&ordered->work_list, &works);
558		btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
559
560		cond_resched();
561		spin_lock(&root->ordered_extent_lock);
562		if (nr != U64_MAX)
563			nr--;
564		count++;
565	}
566	list_splice_tail(&skipped, &root->ordered_extents);
567	list_splice_tail(&splice, &root->ordered_extents);
568	spin_unlock(&root->ordered_extent_lock);
569
570	list_for_each_entry_safe(ordered, next, &works, work_list) {
571		list_del_init(&ordered->work_list);
572		wait_for_completion(&ordered->completion);
573		btrfs_put_ordered_extent(ordered);
574		cond_resched();
575	}
576	mutex_unlock(&root->ordered_extent_mutex);
577
578	return count;
579}
580
581void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
582			     const u64 range_start, const u64 range_len)
583{
584	struct btrfs_root *root;
585	struct list_head splice;
586	u64 done;
587
588	INIT_LIST_HEAD(&splice);
589
590	mutex_lock(&fs_info->ordered_operations_mutex);
591	spin_lock(&fs_info->ordered_root_lock);
592	list_splice_init(&fs_info->ordered_roots, &splice);
593	while (!list_empty(&splice) && nr) {
594		root = list_first_entry(&splice, struct btrfs_root,
595					ordered_root);
596		root = btrfs_grab_root(root);
597		BUG_ON(!root);
598		list_move_tail(&root->ordered_root,
599			       &fs_info->ordered_roots);
600		spin_unlock(&fs_info->ordered_root_lock);
601
602		done = btrfs_wait_ordered_extents(root, nr,
603						  range_start, range_len);
604		btrfs_put_root(root);
605
606		spin_lock(&fs_info->ordered_root_lock);
607		if (nr != U64_MAX) {
608			nr -= done;
609		}
610	}
611	list_splice_tail(&splice, &fs_info->ordered_roots);
612	spin_unlock(&fs_info->ordered_root_lock);
613	mutex_unlock(&fs_info->ordered_operations_mutex);
614}
615
616/*
617 * Used to start IO or wait for a given ordered extent to finish.
618 *
619 * If wait is one, this effectively waits on page writeback for all the pages
620 * in the extent, and it waits on the io completion code to insert
621 * metadata into the btree corresponding to the extent
622 */
623void btrfs_start_ordered_extent(struct inode *inode,
624				       struct btrfs_ordered_extent *entry,
625				       int wait)
626{
627	u64 start = entry->file_offset;
628	u64 end = start + entry->num_bytes - 1;
 
 
629
630	trace_btrfs_ordered_extent_start(inode, entry);
631
632	/*
 
 
 
 
 
 
633	 * pages in the range can be dirty, clean or writeback.  We
634	 * start IO on any dirty ones so the wait doesn't stall waiting
635	 * for the flusher thread to find them
636	 */
637	if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
638		filemap_fdatawrite_range(inode->i_mapping, start, end);
639	if (wait) {
 
 
640		wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
641						 &entry->flags));
642	}
643}
644
645/*
646 * Used to wait on ordered extents across a large range of bytes.
647 */
648int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
649{
650	int ret = 0;
651	int ret_wb = 0;
652	u64 end;
653	u64 orig_end;
654	struct btrfs_ordered_extent *ordered;
655
656	if (start + len < start) {
657		orig_end = INT_LIMIT(loff_t);
658	} else {
659		orig_end = start + len - 1;
660		if (orig_end > INT_LIMIT(loff_t))
661			orig_end = INT_LIMIT(loff_t);
662	}
663
664	/* start IO across the range first to instantiate any delalloc
665	 * extents
666	 */
667	ret = btrfs_fdatawrite_range(inode, start, orig_end);
668	if (ret)
669		return ret;
670
671	/*
672	 * If we have a writeback error don't return immediately. Wait first
673	 * for any ordered extents that haven't completed yet. This is to make
674	 * sure no one can dirty the same page ranges and call writepages()
675	 * before the ordered extents complete - to avoid failures (-EEXIST)
676	 * when adding the new ordered extents to the ordered tree.
677	 */
678	ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
679
680	end = orig_end;
681	while (1) {
682		ordered = btrfs_lookup_first_ordered_extent(inode, end);
683		if (!ordered)
684			break;
685		if (ordered->file_offset > orig_end) {
686			btrfs_put_ordered_extent(ordered);
687			break;
688		}
689		if (ordered->file_offset + ordered->num_bytes <= start) {
690			btrfs_put_ordered_extent(ordered);
691			break;
692		}
693		btrfs_start_ordered_extent(inode, ordered, 1);
694		end = ordered->file_offset;
695		/*
696		 * If the ordered extent had an error save the error but don't
697		 * exit without waiting first for all other ordered extents in
698		 * the range to complete.
699		 */
700		if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
701			ret = -EIO;
702		btrfs_put_ordered_extent(ordered);
703		if (end == 0 || end == start)
704			break;
705		end--;
706	}
707	return ret_wb ? ret_wb : ret;
708}
709
710/*
711 * find an ordered extent corresponding to file_offset.  return NULL if
712 * nothing is found, otherwise take a reference on the extent and return it
713 */
714struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
715							 u64 file_offset)
716{
717	struct btrfs_ordered_inode_tree *tree;
718	struct rb_node *node;
719	struct btrfs_ordered_extent *entry = NULL;
 
720
721	tree = &inode->ordered_tree;
722	spin_lock_irq(&tree->lock);
723	node = tree_search(tree, file_offset);
724	if (!node)
725		goto out;
726
727	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
728	if (!offset_in_entry(entry, file_offset))
729		entry = NULL;
730	if (entry)
731		refcount_inc(&entry->refs);
 
 
732out:
733	spin_unlock_irq(&tree->lock);
734	return entry;
735}
736
737/* Since the DIO code tries to lock a wide area we need to look for any ordered
738 * extents that exist in the range, rather than just the start of the range.
739 */
740struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
741		struct btrfs_inode *inode, u64 file_offset, u64 len)
742{
743	struct btrfs_ordered_inode_tree *tree;
744	struct rb_node *node;
745	struct btrfs_ordered_extent *entry = NULL;
746
747	tree = &inode->ordered_tree;
748	spin_lock_irq(&tree->lock);
749	node = tree_search(tree, file_offset);
750	if (!node) {
751		node = tree_search(tree, file_offset + len);
752		if (!node)
753			goto out;
754	}
755
756	while (1) {
757		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
758		if (range_overlaps(entry, file_offset, len))
759			break;
760
761		if (entry->file_offset >= file_offset + len) {
762			entry = NULL;
763			break;
764		}
765		entry = NULL;
766		node = rb_next(node);
767		if (!node)
768			break;
769	}
770out:
771	if (entry)
772		refcount_inc(&entry->refs);
 
 
773	spin_unlock_irq(&tree->lock);
774	return entry;
775}
776
777/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
778 * lookup and return any extent before 'file_offset'.  NULL is returned
779 * if none is found
780 */
781struct btrfs_ordered_extent *
782btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
783{
784	struct btrfs_ordered_inode_tree *tree;
785	struct rb_node *node;
786	struct btrfs_ordered_extent *entry = NULL;
787
788	tree = &BTRFS_I(inode)->ordered_tree;
789	spin_lock_irq(&tree->lock);
790	node = tree_search(tree, file_offset);
791	if (!node)
792		goto out;
793
794	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
795	refcount_inc(&entry->refs);
 
796out:
797	spin_unlock_irq(&tree->lock);
798	return entry;
799}
800
801/*
802 * search the ordered extents for one corresponding to 'offset' and
803 * try to find a checksum.  This is used because we allow pages to
804 * be reclaimed before their checksum is actually put into the btree
 
 
 
 
805 */
806int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
807			   u8 *sum, int len)
808{
809	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
810	struct btrfs_ordered_sum *ordered_sum;
811	struct btrfs_ordered_extent *ordered;
812	struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
813	unsigned long num_sectors;
814	unsigned long i;
815	u32 sectorsize = btrfs_inode_sectorsize(inode);
816	const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
817	int index = 0;
818
819	ordered = btrfs_lookup_ordered_extent(BTRFS_I(inode), offset);
820	if (!ordered)
821		return 0;
 
 
 
 
 
 
 
822
823	spin_lock_irq(&tree->lock);
824	list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
825		if (disk_bytenr >= ordered_sum->bytenr &&
826		    disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
827			i = (disk_bytenr - ordered_sum->bytenr) >>
828			    inode->i_sb->s_blocksize_bits;
829			num_sectors = ordered_sum->len >>
830				      inode->i_sb->s_blocksize_bits;
831			num_sectors = min_t(int, len - index, num_sectors - i);
832			memcpy(sum + index, ordered_sum->sums + i * csum_size,
833			       num_sectors * csum_size);
834
835			index += (int)num_sectors * csum_size;
836			if (index == len)
837				goto out;
838			disk_bytenr += num_sectors * sectorsize;
839		}
840	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
841out:
 
 
 
 
 
842	spin_unlock_irq(&tree->lock);
843	btrfs_put_ordered_extent(ordered);
844	return index;
845}
846
847/*
848 * btrfs_flush_ordered_range - Lock the passed range and ensures all pending
849 * ordered extents in it are run to completion.
850 *
851 * @inode:        Inode whose ordered tree is to be searched
852 * @start:        Beginning of range to flush
853 * @end:          Last byte of range to lock
854 * @cached_state: If passed, will return the extent state responsible for the
855 * locked range. It's the caller's responsibility to free the cached state.
 
856 *
857 * This function always returns with the given range locked, ensuring after it's
858 * called no order extent can be pending.
859 */
860void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
861					u64 end,
862					struct extent_state **cached_state)
863{
864	struct btrfs_ordered_extent *ordered;
865	struct extent_state *cache = NULL;
866	struct extent_state **cachedp = &cache;
867
868	if (cached_state)
869		cachedp = cached_state;
870
871	while (1) {
872		lock_extent_bits(&inode->io_tree, start, end, cachedp);
873		ordered = btrfs_lookup_ordered_range(inode, start,
874						     end - start + 1);
875		if (!ordered) {
876			/*
877			 * If no external cached_state has been passed then
878			 * decrement the extra ref taken for cachedp since we
879			 * aren't exposing it outside of this function
880			 */
881			if (!cached_state)
882				refcount_dec(&cache->refs);
883			break;
884		}
885		unlock_extent_cached(&inode->io_tree, start, end, cachedp);
886		btrfs_start_ordered_extent(&inode->vfs_inode, ordered, 1);
887		btrfs_put_ordered_extent(ordered);
888	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
889}
890
891int __init ordered_data_init(void)
892{
893	btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
894				     sizeof(struct btrfs_ordered_extent), 0,
895				     SLAB_MEM_SPREAD,
896				     NULL);
897	if (!btrfs_ordered_extent_cache)
898		return -ENOMEM;
899
900	return 0;
901}
902
903void __cold ordered_data_exit(void)
904{
905	kmem_cache_destroy(btrfs_ordered_extent_cache);
906}