extent_io.c 90.2 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/bio.h>
#include <linux/mm.h>
#include <linux/gfp.h>
#include <linux/pagemap.h>
#include <linux/page-flags.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/blkdev.h>
#include <linux/swap.h>
#include <linux/version.h>
#include <linux/writeback.h>
#include <linux/pagevec.h>
#include "extent_io.h"
#include "extent_map.h"
17
#include "compat.h"
18 19
#include "ctree.h"
#include "btrfs_inode.h"
20 21 22 23 24 25 26 27 28 29 30 31

/* temporary define until extent_map moves out of btrfs */
struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
				       unsigned long extra_flags,
				       void (*ctor)(void *, struct kmem_cache *,
						    unsigned long));

static struct kmem_cache *extent_state_cache;
static struct kmem_cache *extent_buffer_cache;

static LIST_HEAD(buffers);
static LIST_HEAD(states);
C
Chris Mason 已提交
32

C
Chris Mason 已提交
33
#define LEAK_DEBUG 1
C
Chris Mason 已提交
34
#ifdef LEAK_DEBUG
35
static spinlock_t leak_lock = SPIN_LOCK_UNLOCKED;
C
Chris Mason 已提交
36
#endif
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74

#define BUFFER_LRU_MAX 64

struct tree_entry {
	u64 start;
	u64 end;
	struct rb_node rb_node;
};

struct extent_page_data {
	struct bio *bio;
	struct extent_io_tree *tree;
	get_extent_t *get_extent;
};

int __init extent_io_init(void)
{
	extent_state_cache = btrfs_cache_create("extent_state",
					    sizeof(struct extent_state), 0,
					    NULL);
	if (!extent_state_cache)
		return -ENOMEM;

	extent_buffer_cache = btrfs_cache_create("extent_buffers",
					    sizeof(struct extent_buffer), 0,
					    NULL);
	if (!extent_buffer_cache)
		goto free_state_cache;
	return 0;

free_state_cache:
	kmem_cache_destroy(extent_state_cache);
	return -ENOMEM;
}

void extent_io_exit(void)
{
	struct extent_state *state;
75
	struct extent_buffer *eb;
76 77

	while (!list_empty(&states)) {
78
		state = list_entry(states.next, struct extent_state, leak_list);
79
		printk("state leak: start %Lu end %Lu state %lu in tree %p refs %d\n", state->start, state->end, state->state, state->tree, atomic_read(&state->refs));
80
		list_del(&state->leak_list);
81 82 83 84
		kmem_cache_free(extent_state_cache, state);

	}

85 86 87 88 89 90
	while (!list_empty(&buffers)) {
		eb = list_entry(buffers.next, struct extent_buffer, leak_list);
		printk("buffer leak start %Lu len %lu refs %d\n", eb->start, eb->len, atomic_read(&eb->refs));
		list_del(&eb->leak_list);
		kmem_cache_free(extent_buffer_cache, eb);
	}
91 92 93 94 95 96 97 98 99 100
	if (extent_state_cache)
		kmem_cache_destroy(extent_state_cache);
	if (extent_buffer_cache)
		kmem_cache_destroy(extent_buffer_cache);
}

void extent_io_tree_init(struct extent_io_tree *tree,
			  struct address_space *mapping, gfp_t mask)
{
	tree->state.rb_node = NULL;
101
	tree->buffer.rb_node = NULL;
102 103
	tree->ops = NULL;
	tree->dirty_bytes = 0;
104
	spin_lock_init(&tree->lock);
105
	spin_lock_init(&tree->buffer_lock);
106 107 108 109 110 111 112
	tree->mapping = mapping;
}
EXPORT_SYMBOL(extent_io_tree_init);

struct extent_state *alloc_extent_state(gfp_t mask)
{
	struct extent_state *state;
C
Chris Mason 已提交
113
#ifdef LEAK_DEBUG
114
	unsigned long flags;
C
Chris Mason 已提交
115
#endif
116 117

	state = kmem_cache_alloc(extent_state_cache, mask);
118
	if (!state)
119 120 121
		return state;
	state->state = 0;
	state->private = 0;
122
	state->tree = NULL;
C
Chris Mason 已提交
123
#ifdef LEAK_DEBUG
124 125 126
	spin_lock_irqsave(&leak_lock, flags);
	list_add(&state->leak_list, &states);
	spin_unlock_irqrestore(&leak_lock, flags);
C
Chris Mason 已提交
127
#endif
128 129 130 131 132 133 134 135 136 137 138
	atomic_set(&state->refs, 1);
	init_waitqueue_head(&state->wq);
	return state;
}
EXPORT_SYMBOL(alloc_extent_state);

void free_extent_state(struct extent_state *state)
{
	if (!state)
		return;
	if (atomic_dec_and_test(&state->refs)) {
C
Chris Mason 已提交
139
#ifdef LEAK_DEBUG
140
		unsigned long flags;
C
Chris Mason 已提交
141
#endif
142
		WARN_ON(state->tree);
C
Chris Mason 已提交
143
#ifdef LEAK_DEBUG
144 145 146
		spin_lock_irqsave(&leak_lock, flags);
		list_del(&state->leak_list);
		spin_unlock_irqrestore(&leak_lock, flags);
C
Chris Mason 已提交
147
#endif
148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177
		kmem_cache_free(extent_state_cache, state);
	}
}
EXPORT_SYMBOL(free_extent_state);

static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
				   struct rb_node *node)
{
	struct rb_node ** p = &root->rb_node;
	struct rb_node * parent = NULL;
	struct tree_entry *entry;

	while(*p) {
		parent = *p;
		entry = rb_entry(parent, struct tree_entry, rb_node);

		if (offset < entry->start)
			p = &(*p)->rb_left;
		else if (offset > entry->end)
			p = &(*p)->rb_right;
		else
			return parent;
	}

	entry = rb_entry(node, struct tree_entry, rb_node);
	rb_link_node(node, parent, p);
	rb_insert_color(node, root);
	return NULL;
}

178
static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
179 180 181
				     struct rb_node **prev_ret,
				     struct rb_node **next_ret)
{
182
	struct rb_root *root = &tree->state;
183 184 185 186 187 188 189 190 191 192 193 194 195 196 197
	struct rb_node * n = root->rb_node;
	struct rb_node *prev = NULL;
	struct rb_node *orig_prev = NULL;
	struct tree_entry *entry;
	struct tree_entry *prev_entry = NULL;

	while(n) {
		entry = rb_entry(n, struct tree_entry, rb_node);
		prev = n;
		prev_entry = entry;

		if (offset < entry->start)
			n = n->rb_left;
		else if (offset > entry->end)
			n = n->rb_right;
198
		else {
199
			return n;
200
		}
201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223
	}

	if (prev_ret) {
		orig_prev = prev;
		while(prev && offset > prev_entry->end) {
			prev = rb_next(prev);
			prev_entry = rb_entry(prev, struct tree_entry, rb_node);
		}
		*prev_ret = prev;
		prev = orig_prev;
	}

	if (next_ret) {
		prev_entry = rb_entry(prev, struct tree_entry, rb_node);
		while(prev && offset < prev_entry->start) {
			prev = rb_prev(prev);
			prev_entry = rb_entry(prev, struct tree_entry, rb_node);
		}
		*next_ret = prev;
	}
	return NULL;
}

224 225
static inline struct rb_node *tree_search(struct extent_io_tree *tree,
					  u64 offset)
226
{
227
	struct rb_node *prev = NULL;
228
	struct rb_node *ret;
229

230 231
	ret = __etree_search(tree, offset, &prev, NULL);
	if (!ret) {
232
		return prev;
233
	}
234 235 236
	return ret;
}

237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280
static struct extent_buffer *buffer_tree_insert(struct extent_io_tree *tree,
					  u64 offset, struct rb_node *node)
{
	struct rb_root *root = &tree->buffer;
	struct rb_node ** p = &root->rb_node;
	struct rb_node * parent = NULL;
	struct extent_buffer *eb;

	while(*p) {
		parent = *p;
		eb = rb_entry(parent, struct extent_buffer, rb_node);

		if (offset < eb->start)
			p = &(*p)->rb_left;
		else if (offset > eb->start)
			p = &(*p)->rb_right;
		else
			return eb;
	}

	rb_link_node(node, parent, p);
	rb_insert_color(node, root);
	return NULL;
}

static struct extent_buffer *buffer_search(struct extent_io_tree *tree,
					   u64 offset)
{
	struct rb_root *root = &tree->buffer;
	struct rb_node * n = root->rb_node;
	struct extent_buffer *eb;

	while(n) {
		eb = rb_entry(n, struct extent_buffer, rb_node);
		if (offset < eb->start)
			n = n->rb_left;
		else if (offset > eb->start)
			n = n->rb_right;
		else
			return eb;
	}
	return NULL;
}

281 282 283 284 285 286 287 288 289 290 291 292 293 294 295
/*
 * utility function to look for merge candidates inside a given range.
 * Any extents with matching state are merged together into a single
 * extent in the tree.  Extents with EXTENT_IO in their state field
 * are not merged because the end_io handlers need to be able to do
 * operations on them without sleeping (or doing allocations/splits).
 *
 * This should be called with the tree lock held.
 */
static int merge_state(struct extent_io_tree *tree,
		       struct extent_state *state)
{
	struct extent_state *other;
	struct rb_node *other_node;

296
	if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
297 298 299 300 301 302 303 304
		return 0;

	other_node = rb_prev(&state->rb_node);
	if (other_node) {
		other = rb_entry(other_node, struct extent_state, rb_node);
		if (other->end == state->start - 1 &&
		    other->state == state->state) {
			state->start = other->start;
305
			other->tree = NULL;
306 307 308 309 310 311 312 313 314 315
			rb_erase(&other->rb_node, &tree->state);
			free_extent_state(other);
		}
	}
	other_node = rb_next(&state->rb_node);
	if (other_node) {
		other = rb_entry(other_node, struct extent_state, rb_node);
		if (other->start == state->end + 1 &&
		    other->state == state->state) {
			other->start = state->start;
316
			state->tree = NULL;
317 318 319 320 321 322 323
			rb_erase(&state->rb_node, &tree->state);
			free_extent_state(state);
		}
	}
	return 0;
}

324 325 326 327 328 329
static void set_state_cb(struct extent_io_tree *tree,
			 struct extent_state *state,
			 unsigned long bits)
{
	if (tree->ops && tree->ops->set_bit_hook) {
		tree->ops->set_bit_hook(tree->mapping->host, state->start,
C
Chris Mason 已提交
330
					state->end, state->state, bits);
331 332 333 334 335 336 337 338 339
	}
}

static void clear_state_cb(struct extent_io_tree *tree,
			   struct extent_state *state,
			   unsigned long bits)
{
	if (tree->ops && tree->ops->set_bit_hook) {
		tree->ops->clear_bit_hook(tree->mapping->host, state->start,
C
Chris Mason 已提交
340
					  state->end, state->state, bits);
341 342 343
	}
}

344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365
/*
 * insert an extent_state struct into the tree.  'bits' are set on the
 * struct before it is inserted.
 *
 * This may return -EEXIST if the extent is already there, in which case the
 * state struct is freed.
 *
 * The tree lock is not taken internally.  This is a utility function and
 * probably isn't what you want to call (see set/clear_extent_bit).
 */
static int insert_state(struct extent_io_tree *tree,
			struct extent_state *state, u64 start, u64 end,
			int bits)
{
	struct rb_node *node;

	if (end < start) {
		printk("end < start %Lu %Lu\n", end, start);
		WARN_ON(1);
	}
	if (bits & EXTENT_DIRTY)
		tree->dirty_bytes += end - start + 1;
C
Chris Mason 已提交
366
	set_state_cb(tree, state, bits);
367 368 369 370 371 372 373 374 375 376 377
	state->state |= bits;
	state->start = start;
	state->end = end;
	node = tree_insert(&tree->state, end, &state->rb_node);
	if (node) {
		struct extent_state *found;
		found = rb_entry(node, struct extent_state, rb_node);
		printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end);
		free_extent_state(state);
		return -EEXIST;
	}
378
	state->tree = tree;
379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413
	merge_state(tree, state);
	return 0;
}

/*
 * split a given extent state struct in two, inserting the preallocated
 * struct 'prealloc' as the newly created second half.  'split' indicates an
 * offset inside 'orig' where it should be split.
 *
 * Before calling,
 * the tree has 'orig' at [orig->start, orig->end].  After calling, there
 * are two extent state structs in the tree:
 * prealloc: [orig->start, split - 1]
 * orig: [ split, orig->end ]
 *
 * The tree locks are not taken by this function. They need to be held
 * by the caller.
 */
static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
		       struct extent_state *prealloc, u64 split)
{
	struct rb_node *node;
	prealloc->start = orig->start;
	prealloc->end = split - 1;
	prealloc->state = orig->state;
	orig->start = split;

	node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
	if (node) {
		struct extent_state *found;
		found = rb_entry(node, struct extent_state, rb_node);
		printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end);
		free_extent_state(prealloc);
		return -EEXIST;
	}
414
	prealloc->tree = tree;
415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436
	return 0;
}

/*
 * utility function to clear some bits in an extent state struct.
 * it will optionally wake up any one waiting on this state (wake == 1), or
 * forcibly remove the state from the tree (delete == 1).
 *
 * If no bits are set on the state struct after clearing things, the
 * struct is freed and removed from the tree
 */
static int clear_state_bit(struct extent_io_tree *tree,
			    struct extent_state *state, int bits, int wake,
			    int delete)
{
	int ret = state->state & bits;

	if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
		u64 range = state->end - state->start + 1;
		WARN_ON(range > tree->dirty_bytes);
		tree->dirty_bytes -= range;
	}
437
	clear_state_cb(tree, state, bits);
C
Chris Mason 已提交
438
	state->state &= ~bits;
439 440 441
	if (wake)
		wake_up(&state->wq);
	if (delete || state->state == 0) {
442
		if (state->tree) {
443
			clear_state_cb(tree, state, state->state);
444
			rb_erase(&state->rb_node, &tree->state);
445
			state->tree = NULL;
446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485
			free_extent_state(state);
		} else {
			WARN_ON(1);
		}
	} else {
		merge_state(tree, state);
	}
	return ret;
}

/*
 * clear some bits on a range in the tree.  This may require splitting
 * or inserting elements in the tree, so the gfp mask is used to
 * indicate which allocations or sleeping are allowed.
 *
 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
 * the given range from the tree regardless of state (ie for truncate).
 *
 * the range [start, end] is inclusive.
 *
 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
 * bits were already set, or zero if none of the bits were already set.
 */
int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
		     int bits, int wake, int delete, gfp_t mask)
{
	struct extent_state *state;
	struct extent_state *prealloc = NULL;
	struct rb_node *node;
	unsigned long flags;
	int err;
	int set = 0;

again:
	if (!prealloc && (mask & __GFP_WAIT)) {
		prealloc = alloc_extent_state(mask);
		if (!prealloc)
			return -ENOMEM;
	}

486
	spin_lock_irqsave(&tree->lock, flags);
487 488 489 490
	/*
	 * this search will find the extents that end after
	 * our range starts
	 */
491
	node = tree_search(tree, start);
492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515
	if (!node)
		goto out;
	state = rb_entry(node, struct extent_state, rb_node);
	if (state->start > end)
		goto out;
	WARN_ON(state->end < start);

	/*
	 *     | ---- desired range ---- |
	 *  | state | or
	 *  | ------------- state -------------- |
	 *
	 * We need to split the extent we found, and may flip
	 * bits on second half.
	 *
	 * If the extent we found extends past our range, we
	 * just split and search again.  It'll get split again
	 * the next time though.
	 *
	 * If the extent we found is inside our range, we clear
	 * the desired bit on it.
	 */

	if (state->start < start) {
516 517
		if (!prealloc)
			prealloc = alloc_extent_state(GFP_ATOMIC);
518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538
		err = split_state(tree, state, prealloc, start);
		BUG_ON(err == -EEXIST);
		prealloc = NULL;
		if (err)
			goto out;
		if (state->end <= end) {
			start = state->end + 1;
			set |= clear_state_bit(tree, state, bits,
					wake, delete);
		} else {
			start = state->start;
		}
		goto search_again;
	}
	/*
	 * | ---- desired range ---- |
	 *                        | state |
	 * We need to split the extent, and clear the bit
	 * on the first half
	 */
	if (state->start <= end && state->end > end) {
539 540
		if (!prealloc)
			prealloc = alloc_extent_state(GFP_ATOMIC);
541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556
		err = split_state(tree, state, prealloc, end + 1);
		BUG_ON(err == -EEXIST);

		if (wake)
			wake_up(&state->wq);
		set |= clear_state_bit(tree, prealloc, bits,
				       wake, delete);
		prealloc = NULL;
		goto out;
	}

	start = state->end + 1;
	set |= clear_state_bit(tree, state, bits, wake, delete);
	goto search_again;

out:
557
	spin_unlock_irqrestore(&tree->lock, flags);
558 559 560 561 562 563 564 565
	if (prealloc)
		free_extent_state(prealloc);

	return set;

search_again:
	if (start > end)
		goto out;
566
	spin_unlock_irqrestore(&tree->lock, flags);
567 568 569 570 571 572 573 574 575 576 577
	if (mask & __GFP_WAIT)
		cond_resched();
	goto again;
}
EXPORT_SYMBOL(clear_extent_bit);

static int wait_on_state(struct extent_io_tree *tree,
			 struct extent_state *state)
{
	DEFINE_WAIT(wait);
	prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
578
	spin_unlock_irq(&tree->lock);
579
	schedule();
580
	spin_lock_irq(&tree->lock);
581 582 583 584 585 586 587 588 589 590 591 592 593 594
	finish_wait(&state->wq, &wait);
	return 0;
}

/*
 * waits for one or more bits to clear on a range in the state tree.
 * The range [start, end] is inclusive.
 * The tree lock is taken by this function
 */
int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
{
	struct extent_state *state;
	struct rb_node *node;

595
	spin_lock_irq(&tree->lock);
596 597 598 599 600 601
again:
	while (1) {
		/*
		 * this search will find all the extents that end after
		 * our range starts
		 */
602
		node = tree_search(tree, start);
603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623
		if (!node)
			break;

		state = rb_entry(node, struct extent_state, rb_node);

		if (state->start > end)
			goto out;

		if (state->state & bits) {
			start = state->start;
			atomic_inc(&state->refs);
			wait_on_state(tree, state);
			free_extent_state(state);
			goto again;
		}
		start = state->end + 1;

		if (start > end)
			break;

		if (need_resched()) {
624
			spin_unlock_irq(&tree->lock);
625
			cond_resched();
626
			spin_lock_irq(&tree->lock);
627 628 629
		}
	}
out:
630
	spin_unlock_irq(&tree->lock);
631 632 633 634 635 636 637 638 639 640 641 642
	return 0;
}
EXPORT_SYMBOL(wait_extent_bit);

static void set_state_bits(struct extent_io_tree *tree,
			   struct extent_state *state,
			   int bits)
{
	if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
		u64 range = state->end - state->start + 1;
		tree->dirty_bytes += range;
	}
643
	set_state_cb(tree, state, bits);
C
Chris Mason 已提交
644
	state->state |= bits;
645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675
}

/*
 * set some bits on a range in the tree.  This may require allocations
 * or sleeping, so the gfp mask is used to indicate what is allowed.
 *
 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the
 * range already has the desired bits set.  The start of the existing
 * range is returned in failed_start in this case.
 *
 * [start, end] is inclusive
 * This takes the tree lock.
 */
int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits,
		   int exclusive, u64 *failed_start, gfp_t mask)
{
	struct extent_state *state;
	struct extent_state *prealloc = NULL;
	struct rb_node *node;
	unsigned long flags;
	int err = 0;
	int set;
	u64 last_start;
	u64 last_end;
again:
	if (!prealloc && (mask & __GFP_WAIT)) {
		prealloc = alloc_extent_state(mask);
		if (!prealloc)
			return -ENOMEM;
	}

676
	spin_lock_irqsave(&tree->lock, flags);
677 678 679 680
	/*
	 * this search will find all the extents that end after
	 * our range starts.
	 */
681
	node = tree_search(tree, start);
682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795
	if (!node) {
		err = insert_state(tree, prealloc, start, end, bits);
		prealloc = NULL;
		BUG_ON(err == -EEXIST);
		goto out;
	}

	state = rb_entry(node, struct extent_state, rb_node);
	last_start = state->start;
	last_end = state->end;

	/*
	 * | ---- desired range ---- |
	 * | state |
	 *
	 * Just lock what we found and keep going
	 */
	if (state->start == start && state->end <= end) {
		set = state->state & bits;
		if (set && exclusive) {
			*failed_start = state->start;
			err = -EEXIST;
			goto out;
		}
		set_state_bits(tree, state, bits);
		start = state->end + 1;
		merge_state(tree, state);
		goto search_again;
	}

	/*
	 *     | ---- desired range ---- |
	 * | state |
	 *   or
	 * | ------------- state -------------- |
	 *
	 * We need to split the extent we found, and may flip bits on
	 * second half.
	 *
	 * If the extent we found extends past our
	 * range, we just split and search again.  It'll get split
	 * again the next time though.
	 *
	 * If the extent we found is inside our range, we set the
	 * desired bit on it.
	 */
	if (state->start < start) {
		set = state->state & bits;
		if (exclusive && set) {
			*failed_start = start;
			err = -EEXIST;
			goto out;
		}
		err = split_state(tree, state, prealloc, start);
		BUG_ON(err == -EEXIST);
		prealloc = NULL;
		if (err)
			goto out;
		if (state->end <= end) {
			set_state_bits(tree, state, bits);
			start = state->end + 1;
			merge_state(tree, state);
		} else {
			start = state->start;
		}
		goto search_again;
	}
	/*
	 * | ---- desired range ---- |
	 *     | state | or               | state |
	 *
	 * There's a hole, we need to insert something in it and
	 * ignore the extent we found.
	 */
	if (state->start > start) {
		u64 this_end;
		if (end < last_start)
			this_end = end;
		else
			this_end = last_start -1;
		err = insert_state(tree, prealloc, start, this_end,
				   bits);
		prealloc = NULL;
		BUG_ON(err == -EEXIST);
		if (err)
			goto out;
		start = this_end + 1;
		goto search_again;
	}
	/*
	 * | ---- desired range ---- |
	 *                        | state |
	 * We need to split the extent, and set the bit
	 * on the first half
	 */
	if (state->start <= end && state->end > end) {
		set = state->state & bits;
		if (exclusive && set) {
			*failed_start = start;
			err = -EEXIST;
			goto out;
		}
		err = split_state(tree, state, prealloc, end + 1);
		BUG_ON(err == -EEXIST);

		set_state_bits(tree, prealloc, bits);
		merge_state(tree, prealloc);
		prealloc = NULL;
		goto out;
	}

	goto search_again;

out:
796
	spin_unlock_irqrestore(&tree->lock, flags);
797 798 799 800 801 802 803 804
	if (prealloc)
		free_extent_state(prealloc);

	return err;

search_again:
	if (start > end)
		goto out;
805
	spin_unlock_irqrestore(&tree->lock, flags);
806 807 808 809 810 811 812 813 814 815 816 817 818 819 820
	if (mask & __GFP_WAIT)
		cond_resched();
	goto again;
}
EXPORT_SYMBOL(set_extent_bit);

/* wrappers around set/clear extent bit */
int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
		     gfp_t mask)
{
	return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
			      mask);
}
EXPORT_SYMBOL(set_extent_dirty);

821 822 823 824 825 826 827
int set_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
		       gfp_t mask)
{
	return set_extent_bit(tree, start, end, EXTENT_ORDERED, 0, NULL, mask);
}
EXPORT_SYMBOL(set_extent_ordered);

828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846
int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
		    int bits, gfp_t mask)
{
	return set_extent_bit(tree, start, end, bits, 0, NULL,
			      mask);
}
EXPORT_SYMBOL(set_extent_bits);

int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
		      int bits, gfp_t mask)
{
	return clear_extent_bit(tree, start, end, bits, 0, 0, mask);
}
EXPORT_SYMBOL(clear_extent_bits);

int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
		     gfp_t mask)
{
	return set_extent_bit(tree, start, end,
847 848
			      EXTENT_DELALLOC | EXTENT_DIRTY,
			      0, NULL, mask);
849 850 851 852 853 854 855 856 857 858 859
}
EXPORT_SYMBOL(set_extent_delalloc);

int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
		       gfp_t mask)
{
	return clear_extent_bit(tree, start, end,
				EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask);
}
EXPORT_SYMBOL(clear_extent_dirty);

860 861 862 863 864 865 866
int clear_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
			 gfp_t mask)
{
	return clear_extent_bit(tree, start, end, EXTENT_ORDERED, 1, 0, mask);
}
EXPORT_SYMBOL(clear_extent_ordered);

867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917
int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
		     gfp_t mask)
{
	return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
			      mask);
}
EXPORT_SYMBOL(set_extent_new);

int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
		       gfp_t mask)
{
	return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask);
}
EXPORT_SYMBOL(clear_extent_new);

int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
			gfp_t mask)
{
	return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
			      mask);
}
EXPORT_SYMBOL(set_extent_uptodate);

int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
			  gfp_t mask)
{
	return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask);
}
EXPORT_SYMBOL(clear_extent_uptodate);

int set_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
			 gfp_t mask)
{
	return set_extent_bit(tree, start, end, EXTENT_WRITEBACK,
			      0, NULL, mask);
}
EXPORT_SYMBOL(set_extent_writeback);

int clear_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
			   gfp_t mask)
{
	return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask);
}
EXPORT_SYMBOL(clear_extent_writeback);

int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end)
{
	return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
}
EXPORT_SYMBOL(wait_on_extent_writeback);

C
Chris Mason 已提交
918 919 920 921
/*
 * either insert or lock state struct between start and end use mask to tell
 * us if waiting is desired.
 */
922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940
int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
{
	int err;
	u64 failed_start;
	while (1) {
		err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
				     &failed_start, mask);
		if (err == -EEXIST && (mask & __GFP_WAIT)) {
			wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
			start = failed_start;
		} else {
			break;
		}
		WARN_ON(start > end);
	}
	return err;
}
EXPORT_SYMBOL(lock_extent);

941 942 943 944 945 946 947 948 949 950 951 952 953 954
int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
		    gfp_t mask)
{
	int err;
	u64 failed_start;

	err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
			     &failed_start, mask);
	if (err == -EEXIST)
		return 0;
	return 1;
}
EXPORT_SYMBOL(try_lock_extent);

955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003
int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
		  gfp_t mask)
{
	return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask);
}
EXPORT_SYMBOL(unlock_extent);

/*
 * helper function to set pages and extents in the tree dirty
 */
int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end)
{
	unsigned long index = start >> PAGE_CACHE_SHIFT;
	unsigned long end_index = end >> PAGE_CACHE_SHIFT;
	struct page *page;

	while (index <= end_index) {
		page = find_get_page(tree->mapping, index);
		BUG_ON(!page);
		__set_page_dirty_nobuffers(page);
		page_cache_release(page);
		index++;
	}
	set_extent_dirty(tree, start, end, GFP_NOFS);
	return 0;
}
EXPORT_SYMBOL(set_range_dirty);

/*
 * helper function to set both pages and extents in the tree writeback
 */
int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
{
	unsigned long index = start >> PAGE_CACHE_SHIFT;
	unsigned long end_index = end >> PAGE_CACHE_SHIFT;
	struct page *page;

	while (index <= end_index) {
		page = find_get_page(tree->mapping, index);
		BUG_ON(!page);
		set_page_writeback(page);
		page_cache_release(page);
		index++;
	}
	set_extent_writeback(tree, start, end, GFP_NOFS);
	return 0;
}
EXPORT_SYMBOL(set_range_writeback);

C
Chris Mason 已提交
1004 1005 1006 1007 1008 1009 1010
/*
 * find the first offset in the io tree with 'bits' set. zero is
 * returned if we find something, and *start_ret and *end_ret are
 * set to reflect the state struct that was found.
 *
 * If nothing was found, 1 is returned, < 0 on error
 */
1011 1012 1013 1014 1015 1016 1017
int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
			  u64 *start_ret, u64 *end_ret, int bits)
{
	struct rb_node *node;
	struct extent_state *state;
	int ret = 1;

1018
	spin_lock_irq(&tree->lock);
1019 1020 1021 1022
	/*
	 * this search will find all the extents that end after
	 * our range starts.
	 */
1023
	node = tree_search(tree, start);
1024
	if (!node) {
1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040
		goto out;
	}

	while(1) {
		state = rb_entry(node, struct extent_state, rb_node);
		if (state->end >= start && (state->state & bits)) {
			*start_ret = state->start;
			*end_ret = state->end;
			ret = 0;
			break;
		}
		node = rb_next(node);
		if (!node)
			break;
	}
out:
1041
	spin_unlock_irq(&tree->lock);
1042 1043 1044 1045
	return ret;
}
EXPORT_SYMBOL(find_first_extent_bit);

C
Chris Mason 已提交
1046 1047 1048 1049
/* find the first state struct with 'bits' set after 'start', and
 * return it.  tree->lock must be held.  NULL will returned if
 * nothing was found after 'start'
 */
C
Chris Mason 已提交
1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060
struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
						 u64 start, int bits)
{
	struct rb_node *node;
	struct extent_state *state;

	/*
	 * this search will find all the extents that end after
	 * our range starts.
	 */
	node = tree_search(tree, start);
1061
	if (!node) {
C
Chris Mason 已提交
1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078
		goto out;
	}

	while(1) {
		state = rb_entry(node, struct extent_state, rb_node);
		if (state->end >= start && (state->state & bits)) {
			return state;
		}
		node = rb_next(node);
		if (!node)
			break;
	}
out:
	return NULL;
}
EXPORT_SYMBOL(find_first_extent_bit_state);

C
Chris Mason 已提交
1079 1080 1081 1082 1083 1084
/*
 * find a contiguous range of bytes in the file marked as delalloc, not
 * more than 'max_bytes'.  start and end are used to return the range,
 *
 * 1 is returned if we find something, 0 if nothing was in the tree
 */
C
Chris Mason 已提交
1085 1086
static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
					u64 *start, u64 *end, u64 max_bytes)
1087 1088 1089 1090 1091 1092 1093
{
	struct rb_node *node;
	struct extent_state *state;
	u64 cur_start = *start;
	u64 found = 0;
	u64 total_bytes = 0;

1094
	spin_lock_irq(&tree->lock);
C
Chris Mason 已提交
1095

1096 1097 1098 1099
	/*
	 * this search will find all the extents that end after
	 * our range starts.
	 */
1100
	node = tree_search(tree, cur_start);
1101
	if (!node) {
1102 1103
		if (!found)
			*end = (u64)-1;
1104 1105 1106 1107 1108
		goto out;
	}

	while(1) {
		state = rb_entry(node, struct extent_state, rb_node);
1109 1110
		if (found && (state->start != cur_start ||
			      (state->state & EXTENT_BOUNDARY))) {
1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130
			goto out;
		}
		if (!(state->state & EXTENT_DELALLOC)) {
			if (!found)
				*end = state->end;
			goto out;
		}
		if (!found)
			*start = state->start;
		found++;
		*end = state->end;
		cur_start = state->end + 1;
		node = rb_next(node);
		if (!node)
			break;
		total_bytes += state->end - state->start + 1;
		if (total_bytes >= max_bytes)
			break;
	}
out:
1131
	spin_unlock_irq(&tree->lock);
1132 1133 1134
	return found;
}

C
Chris Mason 已提交
1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336
static noinline int __unlock_for_delalloc(struct inode *inode,
					  struct page *locked_page,
					  u64 start, u64 end)
{
	int ret;
	struct page *pages[16];
	unsigned long index = start >> PAGE_CACHE_SHIFT;
	unsigned long end_index = end >> PAGE_CACHE_SHIFT;
	unsigned long nr_pages = end_index - index + 1;
	int i;

	if (index == locked_page->index && end_index == index)
		return 0;

	while(nr_pages > 0) {
		ret = find_get_pages_contig(inode->i_mapping, index,
				     min(nr_pages, ARRAY_SIZE(pages)), pages);
		for (i = 0; i < ret; i++) {
			if (pages[i] != locked_page)
				unlock_page(pages[i]);
			page_cache_release(pages[i]);
		}
		nr_pages -= ret;
		index += ret;
		cond_resched();
	}
	return 0;
}

static noinline int lock_delalloc_pages(struct inode *inode,
					struct page *locked_page,
					u64 delalloc_start,
					u64 delalloc_end)
{
	unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
	unsigned long start_index = index;
	unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
	unsigned long pages_locked = 0;
	struct page *pages[16];
	unsigned long nrpages;
	int ret;
	int i;

	/* the caller is responsible for locking the start index */
	if (index == locked_page->index && index == end_index)
		return 0;

	/* skip the page at the start index */
	nrpages = end_index - index + 1;
	while(nrpages > 0) {
		ret = find_get_pages_contig(inode->i_mapping, index,
				     min(nrpages, ARRAY_SIZE(pages)), pages);
		if (ret == 0) {
			ret = -EAGAIN;
			goto done;
		}
		/* now we have an array of pages, lock them all */
		for (i = 0; i < ret; i++) {
			/*
			 * the caller is taking responsibility for
			 * locked_page
			 */
			if (pages[i] != locked_page)
				lock_page(pages[i]);
			page_cache_release(pages[i]);
		}
		pages_locked += ret;
		nrpages -= ret;
		index += ret;
		cond_resched();
	}
	ret = 0;
done:
	if (ret && pages_locked) {
		__unlock_for_delalloc(inode, locked_page,
			      delalloc_start,
			      ((u64)(start_index + pages_locked - 1)) <<
			      PAGE_CACHE_SHIFT);
	}
	return ret;
}

/*
 * find a contiguous range of bytes in the file marked as delalloc, not
 * more than 'max_bytes'.  start and end are used to return the range,
 *
 * 1 is returned if we find something, 0 if nothing was in the tree
 */
static noinline u64 find_lock_delalloc_range(struct inode *inode,
					     struct extent_io_tree *tree,
					     struct page *locked_page,
					     u64 *start, u64 *end,
					     u64 max_bytes)
{
	u64 delalloc_start;
	u64 delalloc_end;
	u64 found;
	int ret;
	int loops = 0;

again:
	/* step one, find a bunch of delalloc bytes starting at start */
	delalloc_start = *start;
	delalloc_end = 0;
	found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
				    max_bytes);
	if (!found) {
		*start = delalloc_start;
		*end = delalloc_end;
		return found;
	}

	/*
	 * make sure to limit the number of pages we try to lock down
	 * if we're looping.
	 */
	if (delalloc_end + 1 - delalloc_start > max_bytes && loops) {
		delalloc_end = (delalloc_start + PAGE_CACHE_SIZE - 1) &
			~((u64)PAGE_CACHE_SIZE - 1);
	}
	/* step two, lock all the pages after the page that has start */
	ret = lock_delalloc_pages(inode, locked_page,
				  delalloc_start, delalloc_end);
	if (ret == -EAGAIN) {
		/* some of the pages are gone, lets avoid looping by
		 * shortening the size of the delalloc range we're searching
		 */
		if (!loops) {
			unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
			max_bytes = PAGE_CACHE_SIZE - offset;
			loops = 1;
			goto again;
		} else {
			found = 0;
			goto out_failed;
		}
	}
	BUG_ON(ret);

	/* step three, lock the state bits for the whole range */
	lock_extent(tree, delalloc_start, delalloc_end, GFP_NOFS);

	/* then test to make sure it is all still delalloc */
	ret = test_range_bit(tree, delalloc_start, delalloc_end,
			     EXTENT_DELALLOC, 1);
	if (!ret) {
		unlock_extent(tree, delalloc_start, delalloc_end, GFP_NOFS);
		__unlock_for_delalloc(inode, locked_page,
			      delalloc_start, delalloc_end);
		cond_resched();
		goto again;
	}
	*start = delalloc_start;
	*end = delalloc_end;
out_failed:
	return found;
}

int extent_clear_unlock_delalloc(struct inode *inode,
				struct extent_io_tree *tree,
				u64 start, u64 end, struct page *locked_page,
				int clear_dirty, int set_writeback,
				int end_writeback)
{
	int ret;
	struct page *pages[16];
	unsigned long index = start >> PAGE_CACHE_SHIFT;
	unsigned long end_index = end >> PAGE_CACHE_SHIFT;
	unsigned long nr_pages = end_index - index + 1;
	int i;
	int clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC;

	if (clear_dirty)
		clear_bits |= EXTENT_DIRTY;

	clear_extent_bit(tree, start, end, clear_bits, 1, 0, GFP_NOFS);

	while(nr_pages > 0) {
		ret = find_get_pages_contig(inode->i_mapping, index,
				     min(nr_pages, ARRAY_SIZE(pages)), pages);
		for (i = 0; i < ret; i++) {
			if (pages[i] == locked_page) {
				page_cache_release(pages[i]);
				continue;
			}
			if (clear_dirty)
				clear_page_dirty_for_io(pages[i]);
			if (set_writeback)
				set_page_writeback(pages[i]);
			if (end_writeback)
				end_page_writeback(pages[i]);
			unlock_page(pages[i]);
			page_cache_release(pages[i]);
		}
		nr_pages -= ret;
		index += ret;
		cond_resched();
	}
	return 0;
}
EXPORT_SYMBOL(extent_clear_unlock_delalloc);

C
Chris Mason 已提交
1337 1338 1339 1340 1341
/*
 * count the number of bytes in the tree that have a given bit(s)
 * set.  This can be fairly slow, except for EXTENT_DIRTY which is
 * cached.  The total number found is returned.
 */
1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357
u64 count_range_bits(struct extent_io_tree *tree,
		     u64 *start, u64 search_end, u64 max_bytes,
		     unsigned long bits)
{
	struct rb_node *node;
	struct extent_state *state;
	u64 cur_start = *start;
	u64 total_bytes = 0;
	int found = 0;

	if (search_end <= cur_start) {
		printk("search_end %Lu start %Lu\n", search_end, cur_start);
		WARN_ON(1);
		return 0;
	}

1358
	spin_lock_irq(&tree->lock);
1359 1360 1361 1362 1363 1364 1365 1366
	if (cur_start == 0 && bits == EXTENT_DIRTY) {
		total_bytes = tree->dirty_bytes;
		goto out;
	}
	/*
	 * this search will find all the extents that end after
	 * our range starts.
	 */
1367
	node = tree_search(tree, cur_start);
1368
	if (!node) {
1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390
		goto out;
	}

	while(1) {
		state = rb_entry(node, struct extent_state, rb_node);
		if (state->start > search_end)
			break;
		if (state->end >= cur_start && (state->state & bits)) {
			total_bytes += min(search_end, state->end) + 1 -
				       max(cur_start, state->start);
			if (total_bytes >= max_bytes)
				break;
			if (!found) {
				*start = state->start;
				found = 1;
			}
		}
		node = rb_next(node);
		if (!node)
			break;
	}
out:
1391
	spin_unlock_irq(&tree->lock);
1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456
	return total_bytes;
}
/*
 * helper function to lock both pages and extents in the tree.
 * pages must be locked first.
 */
int lock_range(struct extent_io_tree *tree, u64 start, u64 end)
{
	unsigned long index = start >> PAGE_CACHE_SHIFT;
	unsigned long end_index = end >> PAGE_CACHE_SHIFT;
	struct page *page;
	int err;

	while (index <= end_index) {
		page = grab_cache_page(tree->mapping, index);
		if (!page) {
			err = -ENOMEM;
			goto failed;
		}
		if (IS_ERR(page)) {
			err = PTR_ERR(page);
			goto failed;
		}
		index++;
	}
	lock_extent(tree, start, end, GFP_NOFS);
	return 0;

failed:
	/*
	 * we failed above in getting the page at 'index', so we undo here
	 * up to but not including the page at 'index'
	 */
	end_index = index;
	index = start >> PAGE_CACHE_SHIFT;
	while (index < end_index) {
		page = find_get_page(tree->mapping, index);
		unlock_page(page);
		page_cache_release(page);
		index++;
	}
	return err;
}
EXPORT_SYMBOL(lock_range);

/*
 * helper function to unlock both pages and extents in the tree.
 */
int unlock_range(struct extent_io_tree *tree, u64 start, u64 end)
{
	unsigned long index = start >> PAGE_CACHE_SHIFT;
	unsigned long end_index = end >> PAGE_CACHE_SHIFT;
	struct page *page;

	while (index <= end_index) {
		page = find_get_page(tree->mapping, index);
		unlock_page(page);
		page_cache_release(page);
		index++;
	}
	unlock_extent(tree, start, end, GFP_NOFS);
	return 0;
}
EXPORT_SYMBOL(unlock_range);

C
Chris Mason 已提交
1457 1458 1459 1460
/*
 * set the private field for a given byte offset in the tree.  If there isn't
 * an extent_state there already, this does nothing.
 */
1461 1462 1463 1464 1465 1466
int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
{
	struct rb_node *node;
	struct extent_state *state;
	int ret = 0;

1467
	spin_lock_irq(&tree->lock);
1468 1469 1470 1471
	/*
	 * this search will find all the extents that end after
	 * our range starts.
	 */
1472
	node = tree_search(tree, start);
1473
	if (!node) {
1474 1475 1476 1477 1478 1479 1480 1481 1482 1483
		ret = -ENOENT;
		goto out;
	}
	state = rb_entry(node, struct extent_state, rb_node);
	if (state->start != start) {
		ret = -ENOENT;
		goto out;
	}
	state->private = private;
out:
1484
	spin_unlock_irq(&tree->lock);
1485 1486 1487 1488 1489 1490 1491 1492 1493
	return ret;
}

int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
{
	struct rb_node *node;
	struct extent_state *state;
	int ret = 0;

1494
	spin_lock_irq(&tree->lock);
1495 1496 1497 1498
	/*
	 * this search will find all the extents that end after
	 * our range starts.
	 */
1499
	node = tree_search(tree, start);
1500
	if (!node) {
1501 1502 1503 1504 1505 1506 1507 1508 1509 1510
		ret = -ENOENT;
		goto out;
	}
	state = rb_entry(node, struct extent_state, rb_node);
	if (state->start != start) {
		ret = -ENOENT;
		goto out;
	}
	*private = state->private;
out:
1511
	spin_unlock_irq(&tree->lock);
1512 1513 1514 1515 1516
	return ret;
}

/*
 * searches a range in the state tree for a given mask.
1517
 * If 'filled' == 1, this returns 1 only if every extent in the tree
1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528
 * has the bits set.  Otherwise, 1 is returned if any bit in the
 * range is found set.
 */
int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
		   int bits, int filled)
{
	struct extent_state *state = NULL;
	struct rb_node *node;
	int bitset = 0;
	unsigned long flags;

1529
	spin_lock_irqsave(&tree->lock, flags);
1530
	node = tree_search(tree, start);
1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559
	while (node && start <= end) {
		state = rb_entry(node, struct extent_state, rb_node);

		if (filled && state->start > start) {
			bitset = 0;
			break;
		}

		if (state->start > end)
			break;

		if (state->state & bits) {
			bitset = 1;
			if (!filled)
				break;
		} else if (filled) {
			bitset = 0;
			break;
		}
		start = state->end + 1;
		if (start > end)
			break;
		node = rb_next(node);
		if (!node) {
			if (filled)
				bitset = 0;
			break;
		}
	}
1560
	spin_unlock_irqrestore(&tree->lock, flags);
1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619
	return bitset;
}
EXPORT_SYMBOL(test_range_bit);

/*
 * helper function to set a given page up to date if all the
 * extents in the tree for that page are up to date
 */
static int check_page_uptodate(struct extent_io_tree *tree,
			       struct page *page)
{
	u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
	u64 end = start + PAGE_CACHE_SIZE - 1;
	if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1))
		SetPageUptodate(page);
	return 0;
}

/*
 * helper function to unlock a page if all the extents in the tree
 * for that page are unlocked
 */
static int check_page_locked(struct extent_io_tree *tree,
			     struct page *page)
{
	u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
	u64 end = start + PAGE_CACHE_SIZE - 1;
	if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0))
		unlock_page(page);
	return 0;
}

/*
 * helper function to end page writeback if all the extents
 * in the tree for that page are done with writeback
 */
static int check_page_writeback(struct extent_io_tree *tree,
			     struct page *page)
{
	u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
	u64 end = start + PAGE_CACHE_SIZE - 1;
	if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0))
		end_page_writeback(page);
	return 0;
}

/* lots and lots of room for performance fixes in the end_bio funcs */

/*
 * after a writepage IO is done, we need to:
 * clear the uptodate bits on error
 * clear the writeback bits in the extent tree for this IO
 * end_page_writeback if the page has no more pending IO
 *
 * Scheduling is not allowed, so the extent state tree is expected
 * to have one and only one object corresponding to this IO.
 */
static void end_bio_extent_writepage(struct bio *bio, int err)
{
1620
	int uptodate = err == 0;
1621
	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1622
	struct extent_io_tree *tree;
1623 1624 1625
	u64 start;
	u64 end;
	int whole_page;
1626
	int ret;
1627 1628 1629

	do {
		struct page *page = bvec->bv_page;
1630 1631
		tree = &BTRFS_I(page->mapping->host)->io_tree;

1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642
		start = ((u64)page->index << PAGE_CACHE_SHIFT) +
			 bvec->bv_offset;
		end = start + bvec->bv_len - 1;

		if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
			whole_page = 1;
		else
			whole_page = 0;

		if (--bvec >= bio->bi_io_vec)
			prefetchw(&bvec->bv_page->flags);
1643 1644
		if (tree->ops && tree->ops->writepage_end_io_hook) {
			ret = tree->ops->writepage_end_io_hook(page, start,
1645
						       end, NULL, uptodate);
1646 1647 1648 1649 1650 1651 1652
			if (ret)
				uptodate = 0;
		}

		if (!uptodate && tree->ops &&
		    tree->ops->writepage_io_failed_hook) {
			ret = tree->ops->writepage_io_failed_hook(bio, page,
1653
							 start, end, NULL);
1654 1655 1656 1657 1658 1659
			if (ret == 0) {
				uptodate = (err == 0);
				continue;
			}
		}

1660 1661 1662 1663 1664
		if (!uptodate) {
			clear_extent_uptodate(tree, start, end, GFP_ATOMIC);
			ClearPageUptodate(page);
			SetPageError(page);
		}
1665

1666
		clear_extent_writeback(tree, start, end, GFP_ATOMIC);
1667 1668 1669 1670 1671 1672

		if (whole_page)
			end_page_writeback(page);
		else
			check_page_writeback(tree, page);
	} while (bvec >= bio->bi_io_vec);
1673

1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691
	bio_put(bio);
}

/*
 * after a readpage IO is done, we need to:
 * clear the uptodate bits on error
 * set the uptodate bits if things worked
 * set the page up to date if all extents in the tree are uptodate
 * clear the lock bit in the extent tree
 * unlock the page if there are no other extents locked for it
 *
 * Scheduling is not allowed, so the extent state tree is expected
 * to have one and only one object corresponding to this IO.
 */
static void end_bio_extent_readpage(struct bio *bio, int err)
{
	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1692
	struct extent_io_tree *tree;
1693 1694 1695 1696 1697 1698 1699
	u64 start;
	u64 end;
	int whole_page;
	int ret;

	do {
		struct page *page = bvec->bv_page;
1700 1701
		tree = &BTRFS_I(page->mapping->host)->io_tree;

1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714
		start = ((u64)page->index << PAGE_CACHE_SHIFT) +
			bvec->bv_offset;
		end = start + bvec->bv_len - 1;

		if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
			whole_page = 1;
		else
			whole_page = 0;

		if (--bvec >= bio->bi_io_vec)
			prefetchw(&bvec->bv_page->flags);

		if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
1715
			ret = tree->ops->readpage_end_io_hook(page, start, end,
1716
							      NULL);
1717 1718 1719
			if (ret)
				uptodate = 0;
		}
1720 1721 1722
		if (!uptodate && tree->ops &&
		    tree->ops->readpage_io_failed_hook) {
			ret = tree->ops->readpage_io_failed_hook(bio, page,
1723
							 start, end, NULL);
1724
			if (ret == 0) {
1725 1726
				uptodate =
					test_bit(BIO_UPTODATE, &bio->bi_flags);
1727 1728 1729
				continue;
			}
		}
1730

1731 1732 1733 1734
		if (uptodate)
			set_extent_uptodate(tree, start, end,
					    GFP_ATOMIC);
		unlock_extent(tree, start, end, GFP_ATOMIC);
1735

1736 1737 1738 1739 1740 1741 1742
		if (whole_page) {
			if (uptodate) {
				SetPageUptodate(page);
			} else {
				ClearPageUptodate(page);
				SetPageError(page);
			}
1743
			unlock_page(page);
1744 1745 1746 1747 1748 1749 1750
		} else {
			if (uptodate) {
				check_page_uptodate(tree, page);
			} else {
				ClearPageUptodate(page);
				SetPageError(page);
			}
1751
			check_page_locked(tree, page);
1752
		}
1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766
	} while (bvec >= bio->bi_io_vec);

	bio_put(bio);
}

/*
 * IO done from prepare_write is pretty simple, we just unlock
 * the structs in the extent tree when done, and set the uptodate bits
 * as appropriate.
 */
static void end_bio_extent_preparewrite(struct bio *bio, int err)
{
	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1767
	struct extent_io_tree *tree;
1768 1769 1770 1771 1772
	u64 start;
	u64 end;

	do {
		struct page *page = bvec->bv_page;
1773 1774
		tree = &BTRFS_I(page->mapping->host)->io_tree;

1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809
		start = ((u64)page->index << PAGE_CACHE_SHIFT) +
			bvec->bv_offset;
		end = start + bvec->bv_len - 1;

		if (--bvec >= bio->bi_io_vec)
			prefetchw(&bvec->bv_page->flags);

		if (uptodate) {
			set_extent_uptodate(tree, start, end, GFP_ATOMIC);
		} else {
			ClearPageUptodate(page);
			SetPageError(page);
		}

		unlock_extent(tree, start, end, GFP_ATOMIC);

	} while (bvec >= bio->bi_io_vec);

	bio_put(bio);
}

static struct bio *
extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
		 gfp_t gfp_flags)
{
	struct bio *bio;

	bio = bio_alloc(gfp_flags, nr_vecs);

	if (bio == NULL && (current->flags & PF_MEMALLOC)) {
		while (!bio && (nr_vecs /= 2))
			bio = bio_alloc(gfp_flags, nr_vecs);
	}

	if (bio) {
1810
		bio->bi_size = 0;
1811 1812 1813 1814 1815 1816
		bio->bi_bdev = bdev;
		bio->bi_sector = first_sector;
	}
	return bio;
}

C
Chris Mason 已提交
1817 1818
static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
			  unsigned long bio_flags)
1819 1820
{
	int ret = 0;
1821 1822 1823 1824 1825 1826 1827 1828 1829
	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
	struct page *page = bvec->bv_page;
	struct extent_io_tree *tree = bio->bi_private;
	u64 start;
	u64 end;

	start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
	end = start + bvec->bv_len - 1;

1830
	bio->bi_private = NULL;
1831 1832 1833

	bio_get(bio);

1834
	if (tree->ops && tree->ops->submit_bio_hook)
1835
		tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
C
Chris Mason 已提交
1836
					   mirror_num, bio_flags);
1837 1838
	else
		submit_bio(rw, bio);
1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850
	if (bio_flagged(bio, BIO_EOPNOTSUPP))
		ret = -EOPNOTSUPP;
	bio_put(bio);
	return ret;
}

static int submit_extent_page(int rw, struct extent_io_tree *tree,
			      struct page *page, sector_t sector,
			      size_t size, unsigned long offset,
			      struct block_device *bdev,
			      struct bio **bio_ret,
			      unsigned long max_pages,
1851
			      bio_end_io_t end_io_func,
C
Chris Mason 已提交
1852 1853 1854
			      int mirror_num,
			      unsigned long prev_bio_flags,
			      unsigned long bio_flags)
1855 1856 1857 1858
{
	int ret = 0;
	struct bio *bio;
	int nr;
C
Chris Mason 已提交
1859 1860 1861 1862
	int contig = 0;
	int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
	int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
	size_t page_size = min(size, PAGE_CACHE_SIZE);
1863 1864 1865

	if (bio_ret && *bio_ret) {
		bio = *bio_ret;
C
Chris Mason 已提交
1866 1867 1868 1869 1870 1871 1872
		if (old_compressed)
			contig = bio->bi_sector == sector;
		else
			contig = bio->bi_sector + (bio->bi_size >> 9) ==
				sector;

		if (prev_bio_flags != bio_flags || !contig ||
1873
		    (tree->ops && tree->ops->merge_bio_hook &&
C
Chris Mason 已提交
1874 1875 1876 1877 1878
		     tree->ops->merge_bio_hook(page, offset, page_size, bio,
					       bio_flags)) ||
		    bio_add_page(bio, page, page_size, offset) < page_size) {
			ret = submit_one_bio(rw, bio, mirror_num,
					     prev_bio_flags);
1879 1880 1881 1882 1883
			bio = NULL;
		} else {
			return 0;
		}
	}
C
Chris Mason 已提交
1884 1885 1886 1887 1888
	if (this_compressed)
		nr = BIO_MAX_PAGES;
	else
		nr = bio_get_nr_vecs(bdev);

1889 1890 1891 1892
	bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
	if (!bio) {
		printk("failed to allocate bio nr %d\n", nr);
	}
1893

C
Chris Mason 已提交
1894
	bio_add_page(bio, page, page_size, offset);
1895 1896
	bio->bi_end_io = end_io_func;
	bio->bi_private = tree;
1897

1898 1899 1900
	if (bio_ret) {
		*bio_ret = bio;
	} else {
C
Chris Mason 已提交
1901
		ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
1902 1903 1904 1905 1906 1907 1908 1909 1910 1911
	}

	return ret;
}

void set_page_extent_mapped(struct page *page)
{
	if (!PagePrivate(page)) {
		SetPagePrivate(page);
		page_cache_get(page);
1912
		set_page_private(page, EXTENT_PAGE_PRIVATE);
1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928
	}
}

void set_page_extent_head(struct page *page, unsigned long len)
{
	set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
}

/*
 * basic readpage implementation.  Locked extent state structs are inserted
 * into the tree that are removed when the IO is done (by the end_io
 * handlers)
 */
static int __extent_read_full_page(struct extent_io_tree *tree,
				   struct page *page,
				   get_extent_t *get_extent,
C
Chris Mason 已提交
1929 1930
				   struct bio **bio, int mirror_num,
				   unsigned long *bio_flags)
1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947
{
	struct inode *inode = page->mapping->host;
	u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
	u64 page_end = start + PAGE_CACHE_SIZE - 1;
	u64 end;
	u64 cur = start;
	u64 extent_offset;
	u64 last_byte = i_size_read(inode);
	u64 block_start;
	u64 cur_end;
	sector_t sector;
	struct extent_map *em;
	struct block_device *bdev;
	int ret;
	int nr = 0;
	size_t page_offset = 0;
	size_t iosize;
C
Chris Mason 已提交
1948
	size_t disk_io_size;
1949
	size_t blocksize = inode->i_sb->s_blocksize;
C
Chris Mason 已提交
1950
	unsigned long this_bio_flag = 0;
1951 1952 1953 1954 1955 1956

	set_page_extent_mapped(page);

	end = page_end;
	lock_extent(tree, start, end, GFP_NOFS);

C
Chris Mason 已提交
1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968
	if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
		char *userpage;
		size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);

		if (zero_offset) {
			iosize = PAGE_CACHE_SIZE - zero_offset;
			userpage = kmap_atomic(page, KM_USER0);
			memset(userpage + zero_offset, 0, iosize);
			flush_dcache_page(page);
			kunmap_atomic(userpage, KM_USER0);
		}
	}
1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989
	while (cur <= end) {
		if (cur >= last_byte) {
			char *userpage;
			iosize = PAGE_CACHE_SIZE - page_offset;
			userpage = kmap_atomic(page, KM_USER0);
			memset(userpage + page_offset, 0, iosize);
			flush_dcache_page(page);
			kunmap_atomic(userpage, KM_USER0);
			set_extent_uptodate(tree, cur, cur + iosize - 1,
					    GFP_NOFS);
			unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
			break;
		}
		em = get_extent(inode, page, page_offset, cur,
				end - cur + 1, 0);
		if (IS_ERR(em) || !em) {
			SetPageError(page);
			unlock_extent(tree, cur, end, GFP_NOFS);
			break;
		}
		extent_offset = cur - em->start;
1990 1991 1992
		if (extent_map_end(em) <= cur) {
printk("bad mapping em [%Lu %Lu] cur %Lu\n", em->start, extent_map_end(em), cur);
		}
1993
		BUG_ON(extent_map_end(em) <= cur);
1994 1995 1996
		if (end < cur) {
printk("2bad mapping end %Lu cur %Lu\n", end, cur);
		}
1997 1998
		BUG_ON(end < cur);

C
Chris Mason 已提交
1999 2000 2001
		if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
			this_bio_flag = EXTENT_BIO_COMPRESSED;

2002 2003 2004
		iosize = min(extent_map_end(em) - cur, end - cur + 1);
		cur_end = min(extent_map_end(em) - 1, end);
		iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
C
Chris Mason 已提交
2005 2006 2007 2008 2009 2010 2011
		if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
			disk_io_size = em->block_len;
			sector = em->block_start >> 9;
		} else {
			sector = (em->block_start + extent_offset) >> 9;
			disk_io_size = iosize;
		}
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033
		bdev = em->bdev;
		block_start = em->block_start;
		free_extent_map(em);
		em = NULL;

		/* we've found a hole, just zero and go on */
		if (block_start == EXTENT_MAP_HOLE) {
			char *userpage;
			userpage = kmap_atomic(page, KM_USER0);
			memset(userpage + page_offset, 0, iosize);
			flush_dcache_page(page);
			kunmap_atomic(userpage, KM_USER0);

			set_extent_uptodate(tree, cur, cur + iosize - 1,
					    GFP_NOFS);
			unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
			cur = cur + iosize;
			page_offset += iosize;
			continue;
		}
		/* the get_extent function already copied into the page */
		if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) {
2034
			check_page_uptodate(tree, page);
2035 2036 2037 2038 2039
			unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
			cur = cur + iosize;
			page_offset += iosize;
			continue;
		}
2040 2041 2042 2043 2044 2045 2046 2047 2048 2049
		/* we have an inline extent but it didn't get marked up
		 * to date.  Error out
		 */
		if (block_start == EXTENT_MAP_INLINE) {
			SetPageError(page);
			unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
			cur = cur + iosize;
			page_offset += iosize;
			continue;
		}
2050 2051 2052 2053 2054 2055 2056

		ret = 0;
		if (tree->ops && tree->ops->readpage_io_hook) {
			ret = tree->ops->readpage_io_hook(page, cur,
							  cur + iosize - 1);
		}
		if (!ret) {
2057 2058
			unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
			pnr -= page->index;
2059
			ret = submit_extent_page(READ, tree, page,
C
Chris Mason 已提交
2060
					 sector, disk_io_size, page_offset,
2061
					 bdev, bio, pnr,
C
Chris Mason 已提交
2062 2063 2064
					 end_bio_extent_readpage, mirror_num,
					 *bio_flags,
					 this_bio_flag);
2065
			nr++;
C
Chris Mason 已提交
2066
			*bio_flags = this_bio_flag;
2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084
		}
		if (ret)
			SetPageError(page);
		cur = cur + iosize;
		page_offset += iosize;
	}
	if (!nr) {
		if (!PageError(page))
			SetPageUptodate(page);
		unlock_page(page);
	}
	return 0;
}

int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
			    get_extent_t *get_extent)
{
	struct bio *bio = NULL;
C
Chris Mason 已提交
2085
	unsigned long bio_flags = 0;
2086 2087
	int ret;

C
Chris Mason 已提交
2088 2089
	ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
				      &bio_flags);
2090
	if (bio)
C
Chris Mason 已提交
2091
		submit_one_bio(READ, bio, 0, bio_flags);
2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116
	return ret;
}
EXPORT_SYMBOL(extent_read_full_page);

/*
 * the writepage semantics are similar to regular writepage.  extent
 * records are inserted to lock ranges in the tree, and as dirty areas
 * are found, they are marked writeback.  Then the lock bits are removed
 * and the end_io handler clears the writeback ranges
 */
static int __extent_writepage(struct page *page, struct writeback_control *wbc,
			      void *data)
{
	struct inode *inode = page->mapping->host;
	struct extent_page_data *epd = data;
	struct extent_io_tree *tree = epd->tree;
	u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
	u64 delalloc_start;
	u64 page_end = start + PAGE_CACHE_SIZE - 1;
	u64 end;
	u64 cur = start;
	u64 extent_offset;
	u64 last_byte = i_size_read(inode);
	u64 block_start;
	u64 iosize;
2117
	u64 unlock_start;
2118 2119 2120 2121 2122
	sector_t sector;
	struct extent_map *em;
	struct block_device *bdev;
	int ret;
	int nr = 0;
2123
	size_t pg_offset = 0;
2124 2125 2126 2127 2128
	size_t blocksize;
	loff_t i_size = i_size_read(inode);
	unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
	u64 nr_delalloc;
	u64 delalloc_end;
C
Chris Mason 已提交
2129 2130
	int page_started;
	int compressed;
2131 2132

	WARN_ON(!PageLocked(page));
2133
	pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2134
	if (page->index > end_index ||
2135
	   (page->index == end_index && !pg_offset)) {
2136
		page->mapping->a_ops->invalidatepage(page, 0);
2137 2138 2139 2140 2141 2142 2143 2144
		unlock_page(page);
		return 0;
	}

	if (page->index == end_index) {
		char *userpage;

		userpage = kmap_atomic(page, KM_USER0);
2145 2146
		memset(userpage + pg_offset, 0,
		       PAGE_CACHE_SIZE - pg_offset);
2147
		kunmap_atomic(userpage, KM_USER0);
2148
		flush_dcache_page(page);
2149
	}
2150
	pg_offset = 0;
2151 2152 2153 2154 2155

	set_page_extent_mapped(page);

	delalloc_start = start;
	delalloc_end = 0;
C
Chris Mason 已提交
2156
	page_started = 0;
2157
	while(delalloc_end < page_end) {
C
Chris Mason 已提交
2158 2159 2160
		nr_delalloc = find_lock_delalloc_range(inode, tree,
						       page,
						       &delalloc_start,
2161 2162 2163 2164 2165 2166
						       &delalloc_end,
						       128 * 1024 * 1024);
		if (nr_delalloc == 0) {
			delalloc_start = delalloc_end + 1;
			continue;
		}
C
Chris Mason 已提交
2167 2168
		tree->ops->fill_delalloc(inode, page, delalloc_start,
					 delalloc_end, &page_started);
2169 2170
		delalloc_start = delalloc_end + 1;
	}
C
Chris Mason 已提交
2171 2172 2173 2174 2175 2176

	/* did the fill delalloc function already unlock and start the IO? */
	if (page_started) {
		return 0;
	}

2177
	lock_extent(tree, start, page_end, GFP_NOFS);
2178
	unlock_start = start;
2179

2180
	if (tree->ops && tree->ops->writepage_start_hook) {
C
Chris Mason 已提交
2181 2182
		ret = tree->ops->writepage_start_hook(page, start,
						      page_end);
2183 2184 2185 2186 2187 2188 2189 2190
		if (ret == -EAGAIN) {
			unlock_extent(tree, start, page_end, GFP_NOFS);
			redirty_page_for_writepage(wbc, page);
			unlock_page(page);
			return 0;
		}
	}

2191 2192 2193 2194 2195 2196 2197
	end = page_end;
	if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
		printk("found delalloc bits after lock_extent\n");
	}

	if (last_byte <= start) {
		clear_extent_dirty(tree, start, page_end, GFP_NOFS);
2198 2199 2200 2201 2202
		unlock_extent(tree, start, page_end, GFP_NOFS);
		if (tree->ops && tree->ops->writepage_end_io_hook)
			tree->ops->writepage_end_io_hook(page, start,
							 page_end, NULL, 1);
		unlock_start = page_end + 1;
2203 2204 2205 2206 2207 2208 2209 2210 2211
		goto done;
	}

	set_extent_uptodate(tree, start, page_end, GFP_NOFS);
	blocksize = inode->i_sb->s_blocksize;

	while (cur <= end) {
		if (cur >= last_byte) {
			clear_extent_dirty(tree, cur, page_end, GFP_NOFS);
2212 2213 2214 2215 2216
			unlock_extent(tree, unlock_start, page_end, GFP_NOFS);
			if (tree->ops && tree->ops->writepage_end_io_hook)
				tree->ops->writepage_end_io_hook(page, cur,
							 page_end, NULL, 1);
			unlock_start = page_end + 1;
2217 2218
			break;
		}
2219
		em = epd->get_extent(inode, page, pg_offset, cur,
2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233
				     end - cur + 1, 1);
		if (IS_ERR(em) || !em) {
			SetPageError(page);
			break;
		}

		extent_offset = cur - em->start;
		BUG_ON(extent_map_end(em) <= cur);
		BUG_ON(end < cur);
		iosize = min(extent_map_end(em) - cur, end - cur + 1);
		iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
		sector = (em->block_start + extent_offset) >> 9;
		bdev = em->bdev;
		block_start = em->block_start;
C
Chris Mason 已提交
2234
		compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2235 2236 2237
		free_extent_map(em);
		em = NULL;

C
Chris Mason 已提交
2238 2239 2240 2241 2242
		/*
		 * compressed and inline extents are written through other
		 * paths in the FS
		 */
		if (compressed || block_start == EXTENT_MAP_HOLE ||
2243 2244 2245
		    block_start == EXTENT_MAP_INLINE) {
			clear_extent_dirty(tree, cur,
					   cur + iosize - 1, GFP_NOFS);
2246 2247 2248

			unlock_extent(tree, unlock_start, cur + iosize -1,
				      GFP_NOFS);
2249

C
Chris Mason 已提交
2250 2251 2252 2253 2254 2255
			/*
			 * end_io notification does not happen here for
			 * compressed extents
			 */
			if (!compressed && tree->ops &&
			    tree->ops->writepage_end_io_hook)
2256 2257 2258
				tree->ops->writepage_end_io_hook(page, cur,
							 cur + iosize - 1,
							 NULL, 1);
C
Chris Mason 已提交
2259 2260 2261 2262 2263 2264 2265 2266 2267
			else if (compressed) {
				/* we don't want to end_page_writeback on
				 * a compressed extent.  this happens
				 * elsewhere
				 */
				nr++;
			}

			cur += iosize;
2268
			pg_offset += iosize;
2269
			unlock_start = cur;
2270 2271 2272 2273 2274 2275
			continue;
		}
		/* leave this out until we have a page_mkwrite call */
		if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
				   EXTENT_DIRTY, 0)) {
			cur = cur + iosize;
2276
			pg_offset += iosize;
2277 2278
			continue;
		}
C
Chris Mason 已提交
2279

2280 2281 2282 2283 2284 2285 2286
		clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS);
		if (tree->ops && tree->ops->writepage_io_hook) {
			ret = tree->ops->writepage_io_hook(page, cur,
						cur + iosize - 1);
		} else {
			ret = 0;
		}
2287
		if (ret) {
2288
			SetPageError(page);
2289
		} else {
2290
			unsigned long max_nr = end_index + 1;
2291

2292 2293 2294 2295 2296 2297 2298 2299 2300
			set_range_writeback(tree, cur, cur + iosize - 1);
			if (!PageWriteback(page)) {
				printk("warning page %lu not writeback, "
				       "cur %llu end %llu\n", page->index,
				       (unsigned long long)cur,
				       (unsigned long long)end);
			}

			ret = submit_extent_page(WRITE, tree, page, sector,
2301
						 iosize, pg_offset, bdev,
2302
						 &epd->bio, max_nr,
C
Chris Mason 已提交
2303 2304
						 end_bio_extent_writepage,
						 0, 0, 0);
2305 2306 2307 2308
			if (ret)
				SetPageError(page);
		}
		cur = cur + iosize;
2309
		pg_offset += iosize;
2310 2311 2312 2313 2314 2315 2316 2317
		nr++;
	}
done:
	if (nr == 0) {
		/* make sure the mapping tag for page dirty gets cleared */
		set_page_writeback(page);
		end_page_writeback(page);
	}
2318 2319
	if (unlock_start <= page_end)
		unlock_extent(tree, unlock_start, page_end, GFP_NOFS);
2320 2321 2322 2323 2324
	unlock_page(page);
	return 0;
}

/**
C
Chris Mason 已提交
2325
 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338
 * @mapping: address space structure to write
 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
 * @writepage: function called for each page
 * @data: data passed to writepage function
 *
 * If a page is already under I/O, write_cache_pages() skips it, even
 * if it's dirty.  This is desirable behaviour for memory-cleaning writeback,
 * but it is INCORRECT for data-integrity system calls such as fsync().  fsync()
 * and msync() need to guarantee that all the data which was dirty at the time
 * the call was made get new I/O started against them.  If wbc->sync_mode is
 * WB_SYNC_ALL then we were called for data integrity and we must wait for
 * existing IO to complete.
 */
C
Chris Mason 已提交
2339 2340 2341 2342
int extent_write_cache_pages(struct extent_io_tree *tree,
			     struct address_space *mapping,
			     struct writeback_control *wbc,
			     writepage_t writepage, void *data)
2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387
{
	struct backing_dev_info *bdi = mapping->backing_dev_info;
	int ret = 0;
	int done = 0;
	struct pagevec pvec;
	int nr_pages;
	pgoff_t index;
	pgoff_t end;		/* Inclusive */
	int scanned = 0;
	int range_whole = 0;

	if (wbc->nonblocking && bdi_write_congested(bdi)) {
		wbc->encountered_congestion = 1;
		return 0;
	}

	pagevec_init(&pvec, 0);
	if (wbc->range_cyclic) {
		index = mapping->writeback_index; /* Start from prev offset */
		end = -1;
	} else {
		index = wbc->range_start >> PAGE_CACHE_SHIFT;
		end = wbc->range_end >> PAGE_CACHE_SHIFT;
		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
			range_whole = 1;
		scanned = 1;
	}
retry:
	while (!done && (index <= end) &&
	       (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
					      PAGECACHE_TAG_DIRTY,
					      min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
		unsigned i;

		scanned = 1;
		for (i = 0; i < nr_pages; i++) {
			struct page *page = pvec.pages[i];

			/*
			 * At this point we hold neither mapping->tree_lock nor
			 * lock on the page itself: the page may be truncated or
			 * invalidated (changing page->mapping to NULL), or even
			 * swizzled back from swapper_space to tmpfs file
			 * mapping
			 */
C
Chris Mason 已提交
2388 2389 2390 2391
			if (tree->ops && tree->ops->write_cache_pages_lock_hook)
				tree->ops->write_cache_pages_lock_hook(page);
			else
				lock_page(page);
2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439

			if (unlikely(page->mapping != mapping)) {
				unlock_page(page);
				continue;
			}

			if (!wbc->range_cyclic && page->index > end) {
				done = 1;
				unlock_page(page);
				continue;
			}

			if (wbc->sync_mode != WB_SYNC_NONE)
				wait_on_page_writeback(page);

			if (PageWriteback(page) ||
			    !clear_page_dirty_for_io(page)) {
				unlock_page(page);
				continue;
			}

			ret = (*writepage)(page, wbc, data);

			if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
				unlock_page(page);
				ret = 0;
			}
			if (ret || (--(wbc->nr_to_write) <= 0))
				done = 1;
			if (wbc->nonblocking && bdi_write_congested(bdi)) {
				wbc->encountered_congestion = 1;
				done = 1;
			}
		}
		pagevec_release(&pvec);
		cond_resched();
	}
	if (!scanned && !done) {
		/*
		 * We hit the last page and there is more work to be done: wrap
		 * back to the start of the file
		 */
		scanned = 1;
		index = 0;
		goto retry;
	}
	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
		mapping->writeback_index = index;
2440

C
Chris Mason 已提交
2441 2442
	if (wbc->range_cont)
		wbc->range_start = index << PAGE_CACHE_SHIFT;
2443 2444
	return ret;
}
C
Chris Mason 已提交
2445
EXPORT_SYMBOL(extent_write_cache_pages);
2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469

int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
			  get_extent_t *get_extent,
			  struct writeback_control *wbc)
{
	int ret;
	struct address_space *mapping = page->mapping;
	struct extent_page_data epd = {
		.bio = NULL,
		.tree = tree,
		.get_extent = get_extent,
	};
	struct writeback_control wbc_writepages = {
		.bdi		= wbc->bdi,
		.sync_mode	= WB_SYNC_NONE,
		.older_than_this = NULL,
		.nr_to_write	= 64,
		.range_start	= page_offset(page) + PAGE_CACHE_SIZE,
		.range_end	= (loff_t)-1,
	};


	ret = __extent_writepage(page, wbc, &epd);

C
Chris Mason 已提交
2470 2471
	extent_write_cache_pages(tree, mapping, &wbc_writepages,
				 __extent_writepage, &epd);
2472
	if (epd.bio) {
C
Chris Mason 已提交
2473
		submit_one_bio(WRITE, epd.bio, 0, 0);
2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491
	}
	return ret;
}
EXPORT_SYMBOL(extent_write_full_page);


int extent_writepages(struct extent_io_tree *tree,
		      struct address_space *mapping,
		      get_extent_t *get_extent,
		      struct writeback_control *wbc)
{
	int ret = 0;
	struct extent_page_data epd = {
		.bio = NULL,
		.tree = tree,
		.get_extent = get_extent,
	};

C
Chris Mason 已提交
2492 2493
	ret = extent_write_cache_pages(tree, mapping, wbc,
				       __extent_writepage, &epd);
2494
	if (epd.bio) {
C
Chris Mason 已提交
2495
		submit_one_bio(WRITE, epd.bio, 0, 0);
2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508
	}
	return ret;
}
EXPORT_SYMBOL(extent_writepages);

int extent_readpages(struct extent_io_tree *tree,
		     struct address_space *mapping,
		     struct list_head *pages, unsigned nr_pages,
		     get_extent_t get_extent)
{
	struct bio *bio = NULL;
	unsigned page_idx;
	struct pagevec pvec;
C
Chris Mason 已提交
2509
	unsigned long bio_flags = 0;
2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527

	pagevec_init(&pvec, 0);
	for (page_idx = 0; page_idx < nr_pages; page_idx++) {
		struct page *page = list_entry(pages->prev, struct page, lru);

		prefetchw(&page->flags);
		list_del(&page->lru);
		/*
		 * what we want to do here is call add_to_page_cache_lru,
		 * but that isn't exported, so we reproduce it here
		 */
		if (!add_to_page_cache(page, mapping,
					page->index, GFP_KERNEL)) {

			/* open coding of lru_cache_add, also not exported */
			page_cache_get(page);
			if (!pagevec_add(&pvec, page))
				__pagevec_lru_add(&pvec);
2528
			__extent_read_full_page(tree, page, get_extent,
C
Chris Mason 已提交
2529
						&bio, 0, &bio_flags);
2530 2531 2532 2533 2534 2535 2536
		}
		page_cache_release(page);
	}
	if (pagevec_count(&pvec))
		__pagevec_lru_add(&pvec);
	BUG_ON(!list_empty(pages));
	if (bio)
C
Chris Mason 已提交
2537
		submit_one_bio(READ, bio, 0, bio_flags);
2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661
	return 0;
}
EXPORT_SYMBOL(extent_readpages);

/*
 * basic invalidatepage code, this waits on any locked or writeback
 * ranges corresponding to the page, and then deletes any extent state
 * records from the tree
 */
int extent_invalidatepage(struct extent_io_tree *tree,
			  struct page *page, unsigned long offset)
{
	u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
	u64 end = start + PAGE_CACHE_SIZE - 1;
	size_t blocksize = page->mapping->host->i_sb->s_blocksize;

	start += (offset + blocksize -1) & ~(blocksize - 1);
	if (start > end)
		return 0;

	lock_extent(tree, start, end, GFP_NOFS);
	wait_on_extent_writeback(tree, start, end);
	clear_extent_bit(tree, start, end,
			 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC,
			 1, 1, GFP_NOFS);
	return 0;
}
EXPORT_SYMBOL(extent_invalidatepage);

/*
 * simple commit_write call, set_range_dirty is used to mark both
 * the pages and the extent records as dirty
 */
int extent_commit_write(struct extent_io_tree *tree,
			struct inode *inode, struct page *page,
			unsigned from, unsigned to)
{
	loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;

	set_page_extent_mapped(page);
	set_page_dirty(page);

	if (pos > inode->i_size) {
		i_size_write(inode, pos);
		mark_inode_dirty(inode);
	}
	return 0;
}
EXPORT_SYMBOL(extent_commit_write);

int extent_prepare_write(struct extent_io_tree *tree,
			 struct inode *inode, struct page *page,
			 unsigned from, unsigned to, get_extent_t *get_extent)
{
	u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
	u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
	u64 block_start;
	u64 orig_block_start;
	u64 block_end;
	u64 cur_end;
	struct extent_map *em;
	unsigned blocksize = 1 << inode->i_blkbits;
	size_t page_offset = 0;
	size_t block_off_start;
	size_t block_off_end;
	int err = 0;
	int iocount = 0;
	int ret = 0;
	int isnew;

	set_page_extent_mapped(page);

	block_start = (page_start + from) & ~((u64)blocksize - 1);
	block_end = (page_start + to - 1) | (blocksize - 1);
	orig_block_start = block_start;

	lock_extent(tree, page_start, page_end, GFP_NOFS);
	while(block_start <= block_end) {
		em = get_extent(inode, page, page_offset, block_start,
				block_end - block_start + 1, 1);
		if (IS_ERR(em) || !em) {
			goto err;
		}
		cur_end = min(block_end, extent_map_end(em) - 1);
		block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
		block_off_end = block_off_start + blocksize;
		isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);

		if (!PageUptodate(page) && isnew &&
		    (block_off_end > to || block_off_start < from)) {
			void *kaddr;

			kaddr = kmap_atomic(page, KM_USER0);
			if (block_off_end > to)
				memset(kaddr + to, 0, block_off_end - to);
			if (block_off_start < from)
				memset(kaddr + block_off_start, 0,
				       from - block_off_start);
			flush_dcache_page(page);
			kunmap_atomic(kaddr, KM_USER0);
		}
		if ((em->block_start != EXTENT_MAP_HOLE &&
		     em->block_start != EXTENT_MAP_INLINE) &&
		    !isnew && !PageUptodate(page) &&
		    (block_off_end > to || block_off_start < from) &&
		    !test_range_bit(tree, block_start, cur_end,
				    EXTENT_UPTODATE, 1)) {
			u64 sector;
			u64 extent_offset = block_start - em->start;
			size_t iosize;
			sector = (em->block_start + extent_offset) >> 9;
			iosize = (cur_end - block_start + blocksize) &
				~((u64)blocksize - 1);
			/*
			 * we've already got the extent locked, but we
			 * need to split the state such that our end_bio
			 * handler can clear the lock.
			 */
			set_extent_bit(tree, block_start,
				       block_start + iosize - 1,
				       EXTENT_LOCKED, 0, NULL, GFP_NOFS);
			ret = submit_extent_page(READ, tree, page,
					 sector, iosize, page_offset, em->bdev,
					 NULL, 1,
C
Chris Mason 已提交
2662 2663
					 end_bio_extent_preparewrite, 0,
					 0, 0);
2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685
			iocount++;
			block_start = block_start + iosize;
		} else {
			set_extent_uptodate(tree, block_start, cur_end,
					    GFP_NOFS);
			unlock_extent(tree, block_start, cur_end, GFP_NOFS);
			block_start = cur_end + 1;
		}
		page_offset = block_start & (PAGE_CACHE_SIZE - 1);
		free_extent_map(em);
	}
	if (iocount) {
		wait_extent_bit(tree, orig_block_start,
				block_end, EXTENT_LOCKED);
	}
	check_page_uptodate(tree, page);
err:
	/* FIXME, zero out newly allocated blocks on error */
	return err;
}
EXPORT_SYMBOL(extent_prepare_write);

2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698
/*
 * a helper for releasepage, this tests for areas of the page that
 * are locked or under IO and drops the related state bits if it is safe
 * to drop the page.
 */
int try_release_extent_state(struct extent_map_tree *map,
			     struct extent_io_tree *tree, struct page *page,
			     gfp_t mask)
{
	u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
	u64 end = start + PAGE_CACHE_SIZE - 1;
	int ret = 1;

2699 2700
	if (test_range_bit(tree, start, end,
			   EXTENT_IOBITS | EXTENT_ORDERED, 0))
2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711
		ret = 0;
	else {
		if ((mask & GFP_NOFS) == GFP_NOFS)
			mask = GFP_NOFS;
		clear_extent_bit(tree, start, end, EXTENT_UPTODATE,
				 1, 1, mask);
	}
	return ret;
}
EXPORT_SYMBOL(try_release_extent_state);

2712 2713 2714 2715 2716 2717
/*
 * a helper for releasepage.  As long as there are no locked extents
 * in the range corresponding to the page, both state records and extent
 * map records are removed
 */
int try_release_extent_mapping(struct extent_map_tree *map,
2718 2719
			       struct extent_io_tree *tree, struct page *page,
			       gfp_t mask)
2720 2721 2722 2723
{
	struct extent_map *em;
	u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
	u64 end = start + PAGE_CACHE_SIZE - 1;
2724

2725 2726
	if ((mask & __GFP_WAIT) &&
	    page->mapping->host->i_size > 16 * 1024 * 1024) {
2727
		u64 len;
2728
		while (start <= end) {
2729
			len = end - start + 1;
2730
			spin_lock(&map->lock);
2731
			em = lookup_extent_mapping(map, start, len);
2732 2733 2734 2735
			if (!em || IS_ERR(em)) {
				spin_unlock(&map->lock);
				break;
			}
2736 2737
			if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
			    em->start != start) {
2738 2739 2740 2741 2742 2743
				spin_unlock(&map->lock);
				free_extent_map(em);
				break;
			}
			if (!test_range_bit(tree, em->start,
					    extent_map_end(em) - 1,
C
Chris Mason 已提交
2744 2745 2746
					    EXTENT_LOCKED | EXTENT_WRITEBACK |
					    EXTENT_ORDERED,
					    0)) {
2747 2748 2749 2750 2751
				remove_extent_mapping(map, em);
				/* once for the rb tree */
				free_extent_map(em);
			}
			start = extent_map_end(em);
2752
			spin_unlock(&map->lock);
2753 2754

			/* once for us */
2755 2756 2757
			free_extent_map(em);
		}
	}
2758
	return try_release_extent_state(map, tree, page, mask);
2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793
}
EXPORT_SYMBOL(try_release_extent_mapping);

sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
		get_extent_t *get_extent)
{
	struct inode *inode = mapping->host;
	u64 start = iblock << inode->i_blkbits;
	sector_t sector = 0;
	struct extent_map *em;

	em = get_extent(inode, NULL, 0, start, (1 << inode->i_blkbits), 0);
	if (!em || IS_ERR(em))
		return 0;

	if (em->block_start == EXTENT_MAP_INLINE ||
	    em->block_start == EXTENT_MAP_HOLE)
		goto out;

	sector = (em->block_start + start - em->start) >> inode->i_blkbits;
out:
	free_extent_map(em);
	return sector;
}

static inline struct page *extent_buffer_page(struct extent_buffer *eb,
					      unsigned long i)
{
	struct page *p;
	struct address_space *mapping;

	if (i == 0)
		return eb->first_page;
	i += eb->start >> PAGE_CACHE_SHIFT;
	mapping = eb->first_page->mapping;
C
Chris Mason 已提交
2794 2795
	if (!mapping)
		return NULL;
2796 2797 2798 2799 2800 2801 2802

	/*
	 * extent_buffer_page is only called after pinning the page
	 * by increasing the reference count.  So we know the page must
	 * be in the radix tree.
	 */
	rcu_read_lock();
2803
	p = radix_tree_lookup(&mapping->page_tree, i);
2804
	rcu_read_unlock();
2805

2806 2807 2808
	return p;
}

2809
static inline unsigned long num_extent_pages(u64 start, u64 len)
2810
{
2811 2812
	return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
		(start >> PAGE_CACHE_SHIFT);
2813 2814
}

2815 2816 2817 2818 2819 2820
static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
						   u64 start,
						   unsigned long len,
						   gfp_t mask)
{
	struct extent_buffer *eb = NULL;
C
Chris Mason 已提交
2821
#ifdef LEAK_DEBUG
2822
	unsigned long flags;
C
Chris Mason 已提交
2823
#endif
2824 2825 2826 2827

	eb = kmem_cache_zalloc(extent_buffer_cache, mask);
	eb->start = start;
	eb->len = len;
2828
	mutex_init(&eb->mutex);
C
Chris Mason 已提交
2829
#ifdef LEAK_DEBUG
2830 2831 2832
	spin_lock_irqsave(&leak_lock, flags);
	list_add(&eb->leak_list, &buffers);
	spin_unlock_irqrestore(&leak_lock, flags);
C
Chris Mason 已提交
2833
#endif
2834 2835 2836 2837 2838 2839 2840
	atomic_set(&eb->refs, 1);

	return eb;
}

static void __free_extent_buffer(struct extent_buffer *eb)
{
C
Chris Mason 已提交
2841
#ifdef LEAK_DEBUG
2842 2843 2844 2845
	unsigned long flags;
	spin_lock_irqsave(&leak_lock, flags);
	list_del(&eb->leak_list);
	spin_unlock_irqrestore(&leak_lock, flags);
C
Chris Mason 已提交
2846
#endif
2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858
	kmem_cache_free(extent_buffer_cache, eb);
}

struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
					  u64 start, unsigned long len,
					  struct page *page0,
					  gfp_t mask)
{
	unsigned long num_pages = num_extent_pages(start, len);
	unsigned long i;
	unsigned long index = start >> PAGE_CACHE_SHIFT;
	struct extent_buffer *eb;
2859
	struct extent_buffer *exists = NULL;
2860 2861 2862 2863
	struct page *p;
	struct address_space *mapping = tree->mapping;
	int uptodate = 1;

2864 2865 2866 2867 2868
	spin_lock(&tree->buffer_lock);
	eb = buffer_search(tree, start);
	if (eb) {
		atomic_inc(&eb->refs);
		spin_unlock(&tree->buffer_lock);
J
Josef Bacik 已提交
2869
		mark_page_accessed(eb->first_page);
2870 2871 2872 2873
		return eb;
	}
	spin_unlock(&tree->buffer_lock);

2874
	eb = __alloc_extent_buffer(tree, start, len, mask);
2875
	if (!eb)
2876 2877 2878 2879 2880 2881 2882 2883 2884 2885
		return NULL;

	if (page0) {
		eb->first_page = page0;
		i = 1;
		index++;
		page_cache_get(page0);
		mark_page_accessed(page0);
		set_page_extent_mapped(page0);
		set_page_extent_head(page0, len);
2886
		uptodate = PageUptodate(page0);
2887 2888 2889 2890 2891 2892 2893
	} else {
		i = 0;
	}
	for (; i < num_pages; i++, index++) {
		p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
		if (!p) {
			WARN_ON(1);
2894
			goto free_eb;
2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911
		}
		set_page_extent_mapped(p);
		mark_page_accessed(p);
		if (i == 0) {
			eb->first_page = p;
			set_page_extent_head(p, len);
		} else {
			set_page_private(p, EXTENT_PAGE_PRIVATE);
		}
		if (!PageUptodate(p))
			uptodate = 0;
		unlock_page(p);
	}
	if (uptodate)
		eb->flags |= EXTENT_UPTODATE;
	eb->flags |= EXTENT_BUFFER_FILLED;

2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923
	spin_lock(&tree->buffer_lock);
	exists = buffer_tree_insert(tree, start, &eb->rb_node);
	if (exists) {
		/* add one reference for the caller */
		atomic_inc(&exists->refs);
		spin_unlock(&tree->buffer_lock);
		goto free_eb;
	}
	spin_unlock(&tree->buffer_lock);

	/* add one reference for the tree */
	atomic_inc(&eb->refs);
2924 2925
	return eb;

2926
free_eb:
2927
	if (!atomic_dec_and_test(&eb->refs))
2928 2929
		return exists;
	for (index = 1; index < i; index++)
2930
		page_cache_release(extent_buffer_page(eb, index));
2931
	page_cache_release(extent_buffer_page(eb, 0));
2932
	__free_extent_buffer(eb);
2933
	return exists;
2934 2935 2936 2937 2938 2939 2940 2941 2942
}
EXPORT_SYMBOL(alloc_extent_buffer);

struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
					 u64 start, unsigned long len,
					  gfp_t mask)
{
	struct extent_buffer *eb;

2943 2944 2945 2946 2947
	spin_lock(&tree->buffer_lock);
	eb = buffer_search(tree, start);
	if (eb)
		atomic_inc(&eb->refs);
	spin_unlock(&tree->buffer_lock);
2948

J
Josef Bacik 已提交
2949 2950 2951
	if (eb)
		mark_page_accessed(eb->first_page);

2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963
	return eb;
}
EXPORT_SYMBOL(find_extent_buffer);

void free_extent_buffer(struct extent_buffer *eb)
{
	if (!eb)
		return;

	if (!atomic_dec_and_test(&eb->refs))
		return;

2964
	WARN_ON(1);
2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983
}
EXPORT_SYMBOL(free_extent_buffer);

int clear_extent_buffer_dirty(struct extent_io_tree *tree,
			      struct extent_buffer *eb)
{
	int set;
	unsigned long i;
	unsigned long num_pages;
	struct page *page;

	u64 start = eb->start;
	u64 end = start + eb->len - 1;

	set = clear_extent_dirty(tree, start, end, GFP_NOFS);
	num_pages = num_extent_pages(eb->start, eb->len);

	for (i = 0; i < num_pages; i++) {
		page = extent_buffer_page(eb, i);
2984
		lock_page(page);
2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001
		if (i == 0)
			set_page_extent_head(page, eb->len);
		else
			set_page_private(page, EXTENT_PAGE_PRIVATE);

		/*
		 * if we're on the last page or the first page and the
		 * block isn't aligned on a page boundary, do extra checks
		 * to make sure we don't clean page that is partially dirty
		 */
		if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
		    ((i == num_pages - 1) &&
		     ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
			start = (u64)page->index << PAGE_CACHE_SHIFT;
			end  = start + PAGE_CACHE_SIZE - 1;
			if (test_range_bit(tree, start, end,
					   EXTENT_DIRTY, 0)) {
3002
				unlock_page(page);
3003 3004 3005 3006
				continue;
			}
		}
		clear_page_dirty_for_io(page);
3007
		spin_lock_irq(&page->mapping->tree_lock);
3008 3009 3010 3011 3012
		if (!PageDirty(page)) {
			radix_tree_tag_clear(&page->mapping->page_tree,
						page_index(page),
						PAGECACHE_TAG_DIRTY);
		}
3013
		spin_unlock_irq(&page->mapping->tree_lock);
3014
		unlock_page(page);
3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041
	}
	return 0;
}
EXPORT_SYMBOL(clear_extent_buffer_dirty);

int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
				    struct extent_buffer *eb)
{
	return wait_on_extent_writeback(tree, eb->start,
					eb->start + eb->len - 1);
}
EXPORT_SYMBOL(wait_on_extent_buffer_writeback);

int set_extent_buffer_dirty(struct extent_io_tree *tree,
			     struct extent_buffer *eb)
{
	unsigned long i;
	unsigned long num_pages;

	num_pages = num_extent_pages(eb->start, eb->len);
	for (i = 0; i < num_pages; i++) {
		struct page *page = extent_buffer_page(eb, i);
		/* writepage may need to do something special for the
		 * first page, we have to make sure page->private is
		 * properly set.  releasepage may drop page->private
		 * on us if the page isn't already dirty.
		 */
3042
		lock_page(page);
3043 3044 3045 3046 3047 3048 3049
		if (i == 0) {
			set_page_extent_head(page, eb->len);
		} else if (PagePrivate(page) &&
			   page->private != EXTENT_PAGE_PRIVATE) {
			set_page_extent_mapped(page);
		}
		__set_page_dirty_nobuffers(extent_buffer_page(eb, i));
3050 3051 3052 3053
		set_extent_dirty(tree, page_offset(page),
				 page_offset(page) + PAGE_CACHE_SIZE -1,
				 GFP_NOFS);
		unlock_page(page);
3054
	}
3055
	return 0;
3056 3057 3058
}
EXPORT_SYMBOL(set_extent_buffer_dirty);

3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072
int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
				struct extent_buffer *eb)
{
	unsigned long i;
	struct page *page;
	unsigned long num_pages;

	num_pages = num_extent_pages(eb->start, eb->len);
	eb->flags &= ~EXTENT_UPTODATE;

	clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
			      GFP_NOFS);
	for (i = 0; i < num_pages; i++) {
		page = extent_buffer_page(eb, i);
C
Chris Mason 已提交
3073 3074
		if (page)
			ClearPageUptodate(page);
3075 3076 3077 3078
	}
	return 0;
}

3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103
int set_extent_buffer_uptodate(struct extent_io_tree *tree,
				struct extent_buffer *eb)
{
	unsigned long i;
	struct page *page;
	unsigned long num_pages;

	num_pages = num_extent_pages(eb->start, eb->len);

	set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
			    GFP_NOFS);
	for (i = 0; i < num_pages; i++) {
		page = extent_buffer_page(eb, i);
		if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
		    ((i == num_pages - 1) &&
		     ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
			check_page_uptodate(tree, page);
			continue;
		}
		SetPageUptodate(page);
	}
	return 0;
}
EXPORT_SYMBOL(set_extent_buffer_uptodate);

3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129
int extent_range_uptodate(struct extent_io_tree *tree,
			  u64 start, u64 end)
{
	struct page *page;
	int ret;
	int pg_uptodate = 1;
	int uptodate;
	unsigned long index;

	ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1);
	if (ret)
		return 1;
	while(start <= end) {
		index = start >> PAGE_CACHE_SHIFT;
		page = find_get_page(tree->mapping, index);
		uptodate = PageUptodate(page);
		page_cache_release(page);
		if (!uptodate) {
			pg_uptodate = 0;
			break;
		}
		start += PAGE_CACHE_SIZE;
	}
	return pg_uptodate;
}

3130
int extent_buffer_uptodate(struct extent_io_tree *tree,
3131
			   struct extent_buffer *eb)
3132
{
3133
	int ret = 0;
3134 3135
	unsigned long num_pages;
	unsigned long i;
3136 3137 3138
	struct page *page;
	int pg_uptodate = 1;

3139
	if (eb->flags & EXTENT_UPTODATE)
C
Chris Mason 已提交
3140
		return 1;
3141

C
Chris Mason 已提交
3142
	ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3143
			   EXTENT_UPTODATE, 1);
C
Chris Mason 已提交
3144 3145
	if (ret)
		return ret;
3146 3147 3148 3149 3150 3151 3152 3153 3154

	num_pages = num_extent_pages(eb->start, eb->len);
	for (i = 0; i < num_pages; i++) {
		page = extent_buffer_page(eb, i);
		if (!PageUptodate(page)) {
			pg_uptodate = 0;
			break;
		}
	}
C
Chris Mason 已提交
3155
	return pg_uptodate;
3156 3157 3158 3159 3160
}
EXPORT_SYMBOL(extent_buffer_uptodate);

int read_extent_buffer_pages(struct extent_io_tree *tree,
			     struct extent_buffer *eb,
3161
			     u64 start, int wait,
3162
			     get_extent_t *get_extent, int mirror_num)
3163 3164 3165 3166 3167 3168
{
	unsigned long i;
	unsigned long start_i;
	struct page *page;
	int err;
	int ret = 0;
3169 3170 3171
	int locked_pages = 0;
	int all_uptodate = 1;
	int inc_all_pages = 0;
3172
	unsigned long num_pages;
3173
	struct bio *bio = NULL;
C
Chris Mason 已提交
3174
	unsigned long bio_flags = 0;
3175

3176 3177 3178
	if (eb->flags & EXTENT_UPTODATE)
		return 0;

3179
	if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195
			   EXTENT_UPTODATE, 1)) {
		return 0;
	}

	if (start) {
		WARN_ON(start < eb->start);
		start_i = (start >> PAGE_CACHE_SHIFT) -
			(eb->start >> PAGE_CACHE_SHIFT);
	} else {
		start_i = 0;
	}

	num_pages = num_extent_pages(eb->start, eb->len);
	for (i = start_i; i < num_pages; i++) {
		page = extent_buffer_page(eb, i);
		if (!wait) {
3196
			if (!trylock_page(page))
3197
				goto unlock_exit;
3198 3199 3200
		} else {
			lock_page(page);
		}
3201
		locked_pages++;
3202
		if (!PageUptodate(page)) {
3203 3204 3205 3206 3207 3208
			all_uptodate = 0;
		}
	}
	if (all_uptodate) {
		if (start_i == 0)
			eb->flags |= EXTENT_UPTODATE;
3209 3210 3211
		if (ret) {
			printk("all up to date but ret is %d\n", ret);
		}
3212 3213 3214 3215 3216 3217 3218 3219 3220 3221
		goto unlock_exit;
	}

	for (i = start_i; i < num_pages; i++) {
		page = extent_buffer_page(eb, i);
		if (inc_all_pages)
			page_cache_get(page);
		if (!PageUptodate(page)) {
			if (start_i == 0)
				inc_all_pages = 1;
3222
			ClearPageError(page);
3223
			err = __extent_read_full_page(tree, page,
3224
						      get_extent, &bio,
C
Chris Mason 已提交
3225
						      mirror_num, &bio_flags);
3226 3227
			if (err) {
				ret = err;
3228
				printk("err %d from __extent_read_full_page\n", ret);
3229 3230 3231 3232 3233 3234
			}
		} else {
			unlock_page(page);
		}
	}

3235
	if (bio)
C
Chris Mason 已提交
3236
		submit_one_bio(READ, bio, mirror_num, bio_flags);
3237

3238
	if (ret || !wait) {
3239 3240
		if (ret)
			printk("ret %d wait %d returning\n", ret, wait);
3241 3242 3243 3244 3245 3246
		return ret;
	}
	for (i = start_i; i < num_pages; i++) {
		page = extent_buffer_page(eb, i);
		wait_on_page_locked(page);
		if (!PageUptodate(page)) {
3247
			printk("page not uptodate after wait_on_page_locked\n");
3248 3249 3250 3251 3252 3253
			ret = -EIO;
		}
	}
	if (!ret)
		eb->flags |= EXTENT_UPTODATE;
	return ret;
3254 3255 3256 3257 3258 3259 3260 3261 3262 3263

unlock_exit:
	i = start_i;
	while(locked_pages > 0) {
		page = extent_buffer_page(eb, i);
		i++;
		unlock_page(page);
		locked_pages--;
	}
	return ret;
3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636
}
EXPORT_SYMBOL(read_extent_buffer_pages);

void read_extent_buffer(struct extent_buffer *eb, void *dstv,
			unsigned long start,
			unsigned long len)
{
	size_t cur;
	size_t offset;
	struct page *page;
	char *kaddr;
	char *dst = (char *)dstv;
	size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
	unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;

	WARN_ON(start > eb->len);
	WARN_ON(start + len > eb->start + eb->len);

	offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);

	while(len > 0) {
		page = extent_buffer_page(eb, i);

		cur = min(len, (PAGE_CACHE_SIZE - offset));
		kaddr = kmap_atomic(page, KM_USER1);
		memcpy(dst, kaddr + offset, cur);
		kunmap_atomic(kaddr, KM_USER1);

		dst += cur;
		len -= cur;
		offset = 0;
		i++;
	}
}
EXPORT_SYMBOL(read_extent_buffer);

int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
			       unsigned long min_len, char **token, char **map,
			       unsigned long *map_start,
			       unsigned long *map_len, int km)
{
	size_t offset = start & (PAGE_CACHE_SIZE - 1);
	char *kaddr;
	struct page *p;
	size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
	unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
	unsigned long end_i = (start_offset + start + min_len - 1) >>
		PAGE_CACHE_SHIFT;

	if (i != end_i)
		return -EINVAL;

	if (i == 0) {
		offset = start_offset;
		*map_start = 0;
	} else {
		offset = 0;
		*map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
	}
	if (start + min_len > eb->len) {
printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len);
		WARN_ON(1);
	}

	p = extent_buffer_page(eb, i);
	kaddr = kmap_atomic(p, km);
	*token = kaddr;
	*map = kaddr + offset;
	*map_len = PAGE_CACHE_SIZE - offset;
	return 0;
}
EXPORT_SYMBOL(map_private_extent_buffer);

int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
		      unsigned long min_len,
		      char **token, char **map,
		      unsigned long *map_start,
		      unsigned long *map_len, int km)
{
	int err;
	int save = 0;
	if (eb->map_token) {
		unmap_extent_buffer(eb, eb->map_token, km);
		eb->map_token = NULL;
		save = 1;
	}
	err = map_private_extent_buffer(eb, start, min_len, token, map,
				       map_start, map_len, km);
	if (!err && save) {
		eb->map_token = *token;
		eb->kaddr = *map;
		eb->map_start = *map_start;
		eb->map_len = *map_len;
	}
	return err;
}
EXPORT_SYMBOL(map_extent_buffer);

void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
{
	kunmap_atomic(token, km);
}
EXPORT_SYMBOL(unmap_extent_buffer);

int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
			  unsigned long start,
			  unsigned long len)
{
	size_t cur;
	size_t offset;
	struct page *page;
	char *kaddr;
	char *ptr = (char *)ptrv;
	size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
	unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
	int ret = 0;

	WARN_ON(start > eb->len);
	WARN_ON(start + len > eb->start + eb->len);

	offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);

	while(len > 0) {
		page = extent_buffer_page(eb, i);

		cur = min(len, (PAGE_CACHE_SIZE - offset));

		kaddr = kmap_atomic(page, KM_USER0);
		ret = memcmp(ptr, kaddr + offset, cur);
		kunmap_atomic(kaddr, KM_USER0);
		if (ret)
			break;

		ptr += cur;
		len -= cur;
		offset = 0;
		i++;
	}
	return ret;
}
EXPORT_SYMBOL(memcmp_extent_buffer);

void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
			 unsigned long start, unsigned long len)
{
	size_t cur;
	size_t offset;
	struct page *page;
	char *kaddr;
	char *src = (char *)srcv;
	size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
	unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;

	WARN_ON(start > eb->len);
	WARN_ON(start + len > eb->start + eb->len);

	offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);

	while(len > 0) {
		page = extent_buffer_page(eb, i);
		WARN_ON(!PageUptodate(page));

		cur = min(len, PAGE_CACHE_SIZE - offset);
		kaddr = kmap_atomic(page, KM_USER1);
		memcpy(kaddr + offset, src, cur);
		kunmap_atomic(kaddr, KM_USER1);

		src += cur;
		len -= cur;
		offset = 0;
		i++;
	}
}
EXPORT_SYMBOL(write_extent_buffer);

void memset_extent_buffer(struct extent_buffer *eb, char c,
			  unsigned long start, unsigned long len)
{
	size_t cur;
	size_t offset;
	struct page *page;
	char *kaddr;
	size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
	unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;

	WARN_ON(start > eb->len);
	WARN_ON(start + len > eb->start + eb->len);

	offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);

	while(len > 0) {
		page = extent_buffer_page(eb, i);
		WARN_ON(!PageUptodate(page));

		cur = min(len, PAGE_CACHE_SIZE - offset);
		kaddr = kmap_atomic(page, KM_USER0);
		memset(kaddr + offset, c, cur);
		kunmap_atomic(kaddr, KM_USER0);

		len -= cur;
		offset = 0;
		i++;
	}
}
EXPORT_SYMBOL(memset_extent_buffer);

void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
			unsigned long dst_offset, unsigned long src_offset,
			unsigned long len)
{
	u64 dst_len = dst->len;
	size_t cur;
	size_t offset;
	struct page *page;
	char *kaddr;
	size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
	unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;

	WARN_ON(src->len != dst_len);

	offset = (start_offset + dst_offset) &
		((unsigned long)PAGE_CACHE_SIZE - 1);

	while(len > 0) {
		page = extent_buffer_page(dst, i);
		WARN_ON(!PageUptodate(page));

		cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));

		kaddr = kmap_atomic(page, KM_USER0);
		read_extent_buffer(src, kaddr + offset, src_offset, cur);
		kunmap_atomic(kaddr, KM_USER0);

		src_offset += cur;
		len -= cur;
		offset = 0;
		i++;
	}
}
EXPORT_SYMBOL(copy_extent_buffer);

static void move_pages(struct page *dst_page, struct page *src_page,
		       unsigned long dst_off, unsigned long src_off,
		       unsigned long len)
{
	char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
	if (dst_page == src_page) {
		memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
	} else {
		char *src_kaddr = kmap_atomic(src_page, KM_USER1);
		char *p = dst_kaddr + dst_off + len;
		char *s = src_kaddr + src_off + len;

		while (len--)
			*--p = *--s;

		kunmap_atomic(src_kaddr, KM_USER1);
	}
	kunmap_atomic(dst_kaddr, KM_USER0);
}

static void copy_pages(struct page *dst_page, struct page *src_page,
		       unsigned long dst_off, unsigned long src_off,
		       unsigned long len)
{
	char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
	char *src_kaddr;

	if (dst_page != src_page)
		src_kaddr = kmap_atomic(src_page, KM_USER1);
	else
		src_kaddr = dst_kaddr;

	memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
	kunmap_atomic(dst_kaddr, KM_USER0);
	if (dst_page != src_page)
		kunmap_atomic(src_kaddr, KM_USER1);
}

void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
			   unsigned long src_offset, unsigned long len)
{
	size_t cur;
	size_t dst_off_in_page;
	size_t src_off_in_page;
	size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
	unsigned long dst_i;
	unsigned long src_i;

	if (src_offset + len > dst->len) {
		printk("memmove bogus src_offset %lu move len %lu len %lu\n",
		       src_offset, len, dst->len);
		BUG_ON(1);
	}
	if (dst_offset + len > dst->len) {
		printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
		       dst_offset, len, dst->len);
		BUG_ON(1);
	}

	while(len > 0) {
		dst_off_in_page = (start_offset + dst_offset) &
			((unsigned long)PAGE_CACHE_SIZE - 1);
		src_off_in_page = (start_offset + src_offset) &
			((unsigned long)PAGE_CACHE_SIZE - 1);

		dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
		src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;

		cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
					       src_off_in_page));
		cur = min_t(unsigned long, cur,
			(unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));

		copy_pages(extent_buffer_page(dst, dst_i),
			   extent_buffer_page(dst, src_i),
			   dst_off_in_page, src_off_in_page, cur);

		src_offset += cur;
		dst_offset += cur;
		len -= cur;
	}
}
EXPORT_SYMBOL(memcpy_extent_buffer);

void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
			   unsigned long src_offset, unsigned long len)
{
	size_t cur;
	size_t dst_off_in_page;
	size_t src_off_in_page;
	unsigned long dst_end = dst_offset + len - 1;
	unsigned long src_end = src_offset + len - 1;
	size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
	unsigned long dst_i;
	unsigned long src_i;

	if (src_offset + len > dst->len) {
		printk("memmove bogus src_offset %lu move len %lu len %lu\n",
		       src_offset, len, dst->len);
		BUG_ON(1);
	}
	if (dst_offset + len > dst->len) {
		printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
		       dst_offset, len, dst->len);
		BUG_ON(1);
	}
	if (dst_offset < src_offset) {
		memcpy_extent_buffer(dst, dst_offset, src_offset, len);
		return;
	}
	while(len > 0) {
		dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
		src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;

		dst_off_in_page = (start_offset + dst_end) &
			((unsigned long)PAGE_CACHE_SIZE - 1);
		src_off_in_page = (start_offset + src_end) &
			((unsigned long)PAGE_CACHE_SIZE - 1);

		cur = min_t(unsigned long, len, src_off_in_page + 1);
		cur = min(cur, dst_off_in_page + 1);
		move_pages(extent_buffer_page(dst, dst_i),
			   extent_buffer_page(dst, src_i),
			   dst_off_in_page - cur + 1,
			   src_off_in_page - cur + 1, cur);

		dst_end -= cur;
		src_end -= cur;
		len -= cur;
	}
}
EXPORT_SYMBOL(memmove_extent_buffer);
3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656

int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
{
	u64 start = page_offset(page);
	struct extent_buffer *eb;
	int ret = 1;
	unsigned long i;
	unsigned long num_pages;

	spin_lock(&tree->buffer_lock);
	eb = buffer_search(tree, start);
	if (!eb)
		goto out;

	if (atomic_read(&eb->refs) > 1) {
		ret = 0;
		goto out;
	}
	/* at this point we can safely release the extent buffer */
	num_pages = num_extent_pages(eb->start, eb->len);
C
Christoph Hellwig 已提交
3657 3658
	for (i = 0; i < num_pages; i++)
		page_cache_release(extent_buffer_page(eb, i));
3659 3660 3661 3662 3663 3664 3665
	rb_erase(&eb->rb_node, &tree->buffer);
	__free_extent_buffer(eb);
out:
	spin_unlock(&tree->buffer_lock);
	return ret;
}
EXPORT_SYMBOL(try_release_extent_buffer);