extent_io.c 94.8 KB
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#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/bio.h>
#include <linux/mm.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/writeback.h>
#include <linux/pagevec.h>
#include "extent_io.h"
#include "extent_map.h"
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#include "compat.h"
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#include "ctree.h"
#include "btrfs_inode.h"
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static struct kmem_cache *extent_state_cache;
static struct kmem_cache *extent_buffer_cache;

static LIST_HEAD(buffers);
static LIST_HEAD(states);
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#define LEAK_DEBUG 0
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#if LEAK_DEBUG
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static DEFINE_SPINLOCK(leak_lock);
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#endif
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#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;
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	/* tells writepage not to lock the state bits for this range
	 * it still does the unlocking
	 */
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	unsigned int extent_locked:1;

	/* tells the submit_bio code to use a WRITE_SYNC */
	unsigned int sync_io:1;
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};

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

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	extent_buffer_cache = kmem_cache_create("extent_buffers",
			sizeof(struct extent_buffer), 0,
			SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
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	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;
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	struct extent_buffer *eb;
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	while (!list_empty(&states)) {
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		state = list_entry(states.next, struct extent_state, leak_list);
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		printk(KERN_ERR "btrfs state leak: start %llu end %llu "
		       "state %lu in tree %p refs %d\n",
		       (unsigned long long)state->start,
		       (unsigned long long)state->end,
		       state->state, state->tree, atomic_read(&state->refs));
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		list_del(&state->leak_list);
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		kmem_cache_free(extent_state_cache, state);

	}

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	while (!list_empty(&buffers)) {
		eb = list_entry(buffers.next, struct extent_buffer, leak_list);
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		printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
		       "refs %d\n", (unsigned long long)eb->start,
		       eb->len, atomic_read(&eb->refs));
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		list_del(&eb->leak_list);
		kmem_cache_free(extent_buffer_cache, eb);
	}
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	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)
{
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	tree->state = RB_ROOT;
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	INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
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	tree->ops = NULL;
	tree->dirty_bytes = 0;
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	spin_lock_init(&tree->lock);
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	spin_lock_init(&tree->buffer_lock);
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	tree->mapping = mapping;
}

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static struct extent_state *alloc_extent_state(gfp_t mask)
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{
	struct extent_state *state;
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#if LEAK_DEBUG
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	unsigned long flags;
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#endif
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	state = kmem_cache_alloc(extent_state_cache, mask);
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	if (!state)
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		return state;
	state->state = 0;
	state->private = 0;
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	state->tree = NULL;
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#if LEAK_DEBUG
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	spin_lock_irqsave(&leak_lock, flags);
	list_add(&state->leak_list, &states);
	spin_unlock_irqrestore(&leak_lock, flags);
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#endif
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	atomic_set(&state->refs, 1);
	init_waitqueue_head(&state->wq);
	return state;
}

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void free_extent_state(struct extent_state *state)
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{
	if (!state)
		return;
	if (atomic_dec_and_test(&state->refs)) {
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#if LEAK_DEBUG
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		unsigned long flags;
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#endif
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		WARN_ON(state->tree);
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#if LEAK_DEBUG
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		spin_lock_irqsave(&leak_lock, flags);
		list_del(&state->leak_list);
		spin_unlock_irqrestore(&leak_lock, flags);
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#endif
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		kmem_cache_free(extent_state_cache, state);
	}
}

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

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	while (*p) {
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		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;
}

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static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
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				     struct rb_node **prev_ret,
				     struct rb_node **next_ret)
{
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	struct rb_root *root = &tree->state;
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	struct rb_node *n = root->rb_node;
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	struct rb_node *prev = NULL;
	struct rb_node *orig_prev = NULL;
	struct tree_entry *entry;
	struct tree_entry *prev_entry = NULL;

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	while (n) {
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		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;
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		else
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			return n;
	}

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

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static inline struct rb_node *tree_search(struct extent_io_tree *tree,
					  u64 offset)
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{
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	struct rb_node *prev = NULL;
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	struct rb_node *ret;
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	ret = __etree_search(tree, offset, &prev, NULL);
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	if (!ret)
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		return prev;
	return ret;
}

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static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
		     struct extent_state *other)
{
	if (tree->ops && tree->ops->merge_extent_hook)
		tree->ops->merge_extent_hook(tree->mapping->host, new,
					     other);
}

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/*
 * 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;

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	if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
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		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) {
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			merge_cb(tree, state, other);
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			state->start = other->start;
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			other->tree = NULL;
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			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) {
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			merge_cb(tree, state, other);
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			other->start = state->start;
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			state->tree = NULL;
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			rb_erase(&state->rb_node, &tree->state);
			free_extent_state(state);
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			state = NULL;
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		}
	}
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	return 0;
}

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static int set_state_cb(struct extent_io_tree *tree,
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			 struct extent_state *state, int *bits)
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{
	if (tree->ops && tree->ops->set_bit_hook) {
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		return tree->ops->set_bit_hook(tree->mapping->host,
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					       state, bits);
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	}
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	return 0;
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}

static void clear_state_cb(struct extent_io_tree *tree,
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			   struct extent_state *state, int *bits)
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{
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	if (tree->ops && tree->ops->clear_bit_hook)
		tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
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}

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/*
 * 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,
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			int *bits)
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{
	struct rb_node *node;
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	int bits_to_set = *bits & ~EXTENT_CTLBITS;
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	int ret;
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	if (end < start) {
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		printk(KERN_ERR "btrfs end < start %llu %llu\n",
		       (unsigned long long)end,
		       (unsigned long long)start);
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		WARN_ON(1);
	}
	state->start = start;
	state->end = end;
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	ret = set_state_cb(tree, state, bits);
	if (ret)
		return ret;

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	if (bits_to_set & EXTENT_DIRTY)
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		tree->dirty_bytes += end - start + 1;
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	state->state |= bits_to_set;
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	node = tree_insert(&tree->state, end, &state->rb_node);
	if (node) {
		struct extent_state *found;
		found = rb_entry(node, struct extent_state, rb_node);
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		printk(KERN_ERR "btrfs found node %llu %llu on insert of "
		       "%llu %llu\n", (unsigned long long)found->start,
		       (unsigned long long)found->end,
		       (unsigned long long)start, (unsigned long long)end);
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		free_extent_state(state);
		return -EEXIST;
	}
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	state->tree = tree;
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	merge_state(tree, state);
	return 0;
}

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static int split_cb(struct extent_io_tree *tree, struct extent_state *orig,
		     u64 split)
{
	if (tree->ops && tree->ops->split_extent_hook)
		return tree->ops->split_extent_hook(tree->mapping->host,
						    orig, split);
	return 0;
}

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/*
 * 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;
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	split_cb(tree, orig, split);

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	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) {
		free_extent_state(prealloc);
		return -EEXIST;
	}
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	prealloc->tree = tree;
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	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,
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			    struct extent_state *state,
			    int *bits, int wake)
415
{
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	int bits_to_clear = *bits & ~EXTENT_CTLBITS;
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	int ret = state->state & bits_to_clear;
418

419
	if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
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		u64 range = state->end - state->start + 1;
		WARN_ON(range > tree->dirty_bytes);
		tree->dirty_bytes -= range;
	}
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	clear_state_cb(tree, state, bits);
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	state->state &= ~bits_to_clear;
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	if (wake)
		wake_up(&state->wq);
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	if (state->state == 0) {
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		if (state->tree) {
430
			rb_erase(&state->rb_node, &tree->state);
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			state->tree = NULL;
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			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,
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		     int bits, int wake, int delete,
		     struct extent_state **cached_state,
		     gfp_t mask)
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{
	struct extent_state *state;
461
	struct extent_state *cached;
462
	struct extent_state *prealloc = NULL;
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	struct rb_node *next_node;
464
	struct rb_node *node;
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	u64 last_end;
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	int err;
	int set = 0;
468
	int clear = 0;
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	if (delete)
		bits |= ~EXTENT_CTLBITS;
	bits |= EXTENT_FIRST_DELALLOC;

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	if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
		clear = 1;
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again:
	if (!prealloc && (mask & __GFP_WAIT)) {
		prealloc = alloc_extent_state(mask);
		if (!prealloc)
			return -ENOMEM;
	}

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	spin_lock(&tree->lock);
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	if (cached_state) {
		cached = *cached_state;
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		if (clear) {
			*cached_state = NULL;
			cached_state = NULL;
		}

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		if (cached && cached->tree && cached->start == start) {
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			if (clear)
				atomic_dec(&cached->refs);
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			state = cached;
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			goto hit_next;
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		}
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		if (clear)
			free_extent_state(cached);
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	}
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	/*
	 * this search will find the extents that end after
	 * our range starts
	 */
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	node = tree_search(tree, start);
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	if (!node)
		goto out;
	state = rb_entry(node, struct extent_state, rb_node);
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hit_next:
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	if (state->start > end)
		goto out;
	WARN_ON(state->end < start);
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	last_end = state->end;
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	/*
	 *     | ---- 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) {
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		if (!prealloc)
			prealloc = alloc_extent_state(GFP_ATOMIC);
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		err = split_state(tree, state, prealloc, start);
		BUG_ON(err == -EEXIST);
		prealloc = NULL;
		if (err)
			goto out;
		if (state->end <= end) {
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			set |= clear_state_bit(tree, state, &bits, wake);
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			if (last_end == (u64)-1)
				goto out;
			start = last_end + 1;
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		}
		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) {
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		if (!prealloc)
			prealloc = alloc_extent_state(GFP_ATOMIC);
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		err = split_state(tree, state, prealloc, end + 1);
		BUG_ON(err == -EEXIST);
		if (wake)
			wake_up(&state->wq);
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561
		set |= clear_state_bit(tree, prealloc, &bits, wake);
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		prealloc = NULL;
		goto out;
	}
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	if (state->end < end && prealloc && !need_resched())
		next_node = rb_next(&state->rb_node);
	else
		next_node = NULL;
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572
	set |= clear_state_bit(tree, state, &bits, wake);
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	if (last_end == (u64)-1)
		goto out;
	start = last_end + 1;
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	if (start <= end && next_node) {
		state = rb_entry(next_node, struct extent_state,
				 rb_node);
		if (state->start == start)
			goto hit_next;
	}
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	goto search_again;

out:
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	spin_unlock(&tree->lock);
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	if (prealloc)
		free_extent_state(prealloc);

	return set;

search_again:
	if (start > end)
		goto out;
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	spin_unlock(&tree->lock);
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	if (mask & __GFP_WAIT)
		cond_resched();
	goto again;
}

static int wait_on_state(struct extent_io_tree *tree,
			 struct extent_state *state)
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		__releases(tree->lock)
		__acquires(tree->lock)
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{
	DEFINE_WAIT(wait);
	prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
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	spin_unlock(&tree->lock);
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	schedule();
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	spin_lock(&tree->lock);
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	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;

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	spin_lock(&tree->lock);
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again:
	while (1) {
		/*
		 * this search will find all the extents that end after
		 * our range starts
		 */
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		node = tree_search(tree, start);
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		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()) {
653
			spin_unlock(&tree->lock);
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			cond_resched();
655
			spin_lock(&tree->lock);
656 657 658
		}
	}
out:
659
	spin_unlock(&tree->lock);
660 661 662
	return 0;
}

J
Josef Bacik 已提交
663
static int set_state_bits(struct extent_io_tree *tree,
664
			   struct extent_state *state,
665
			   int *bits)
666
{
J
Josef Bacik 已提交
667
	int ret;
668
	int bits_to_set = *bits & ~EXTENT_CTLBITS;
J
Josef Bacik 已提交
669 670 671 672

	ret = set_state_cb(tree, state, bits);
	if (ret)
		return ret;
673
	if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
674 675 676
		u64 range = state->end - state->start + 1;
		tree->dirty_bytes += range;
	}
677
	state->state |= bits_to_set;
J
Josef Bacik 已提交
678 679

	return 0;
680 681
}

682 683 684 685 686 687 688 689 690 691 692
static void cache_state(struct extent_state *state,
			struct extent_state **cached_ptr)
{
	if (cached_ptr && !(*cached_ptr)) {
		if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
			*cached_ptr = state;
			atomic_inc(&state->refs);
		}
	}
}

693
/*
694 695
 * 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.
696
 *
697 698 699
 * If any of the exclusive bits are set, 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.
700
 *
701
 * [start, end] is inclusive This takes the tree lock.
702
 */
703

704 705 706
int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
		   int bits, int exclusive_bits, u64 *failed_start,
		   struct extent_state **cached_state, gfp_t mask)
707 708 709 710 711 712 713
{
	struct extent_state *state;
	struct extent_state *prealloc = NULL;
	struct rb_node *node;
	int err = 0;
	u64 last_start;
	u64 last_end;
714

715
	bits |= EXTENT_FIRST_DELALLOC;
716 717 718 719 720 721 722
again:
	if (!prealloc && (mask & __GFP_WAIT)) {
		prealloc = alloc_extent_state(mask);
		if (!prealloc)
			return -ENOMEM;
	}

723
	spin_lock(&tree->lock);
724 725 726 727 728 729 730
	if (cached_state && *cached_state) {
		state = *cached_state;
		if (state->start == start && state->tree) {
			node = &state->rb_node;
			goto hit_next;
		}
	}
731 732 733 734
	/*
	 * this search will find all the extents that end after
	 * our range starts.
	 */
735
	node = tree_search(tree, start);
736
	if (!node) {
737
		err = insert_state(tree, prealloc, start, end, &bits);
738 739 740 741 742
		prealloc = NULL;
		BUG_ON(err == -EEXIST);
		goto out;
	}
	state = rb_entry(node, struct extent_state, rb_node);
C
Chris Mason 已提交
743
hit_next:
744 745 746 747 748 749 750 751 752 753
	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) {
C
Chris Mason 已提交
754
		struct rb_node *next_node;
755
		if (state->state & exclusive_bits) {
756 757 758 759
			*failed_start = state->start;
			err = -EEXIST;
			goto out;
		}
760

761
		err = set_state_bits(tree, state, &bits);
J
Josef Bacik 已提交
762 763 764
		if (err)
			goto out;

765
		cache_state(state, cached_state);
766
		merge_state(tree, state);
767 768
		if (last_end == (u64)-1)
			goto out;
C
Chris Mason 已提交
769

770
		start = last_end + 1;
C
Chris Mason 已提交
771 772 773 774 775 776 777 778 779
		if (start < end && prealloc && !need_resched()) {
			next_node = rb_next(node);
			if (next_node) {
				state = rb_entry(next_node, struct extent_state,
						 rb_node);
				if (state->start == start)
					goto hit_next;
			}
		}
780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799
		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) {
800
		if (state->state & exclusive_bits) {
801 802 803 804 805 806 807 808 809 810
			*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) {
811
			err = set_state_bits(tree, state, &bits);
J
Josef Bacik 已提交
812 813
			if (err)
				goto out;
814
			cache_state(state, cached_state);
815
			merge_state(tree, state);
816 817 818
			if (last_end == (u64)-1)
				goto out;
			start = last_end + 1;
819 820 821 822 823 824 825 826 827 828 829 830 831 832 833
		}
		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
C
Chris Mason 已提交
834
			this_end = last_start - 1;
835
		err = insert_state(tree, prealloc, start, this_end,
836
				   &bits);
837
		BUG_ON(err == -EEXIST);
J
Josef Bacik 已提交
838 839
		if (err) {
			prealloc = NULL;
840
			goto out;
J
Josef Bacik 已提交
841 842 843
		}
		cache_state(prealloc, cached_state);
		prealloc = NULL;
844 845 846 847 848 849 850 851 852 853
		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) {
854
		if (state->state & exclusive_bits) {
855 856 857 858 859 860 861
			*failed_start = start;
			err = -EEXIST;
			goto out;
		}
		err = split_state(tree, state, prealloc, end + 1);
		BUG_ON(err == -EEXIST);

862
		err = set_state_bits(tree, prealloc, &bits);
J
Josef Bacik 已提交
863 864 865 866
		if (err) {
			prealloc = NULL;
			goto out;
		}
867
		cache_state(prealloc, cached_state);
868 869 870 871 872 873 874 875
		merge_state(tree, prealloc);
		prealloc = NULL;
		goto out;
	}

	goto search_again;

out:
876
	spin_unlock(&tree->lock);
877 878 879 880 881 882 883 884
	if (prealloc)
		free_extent_state(prealloc);

	return err;

search_again:
	if (start > end)
		goto out;
885
	spin_unlock(&tree->lock);
886 887 888 889 890 891 892 893 894 895
	if (mask & __GFP_WAIT)
		cond_resched();
	goto again;
}

/* 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,
896
			      NULL, mask);
897 898 899 900 901 902
}

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,
903
			      NULL, mask);
904 905 906 907 908
}

int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
		      int bits, gfp_t mask)
{
909
	return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
910 911 912
}

int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
913
			struct extent_state **cached_state, gfp_t mask)
914 915
{
	return set_extent_bit(tree, start, end,
C
Chris Mason 已提交
916
			      EXTENT_DELALLOC | EXTENT_DIRTY | EXTENT_UPTODATE,
917
			      0, NULL, cached_state, mask);
918 919 920 921 922 923
}

int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
		       gfp_t mask)
{
	return clear_extent_bit(tree, start, end,
924
				EXTENT_DIRTY | EXTENT_DELALLOC |
925
				EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
926 927 928 929 930 931
}

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,
932
			      NULL, mask);
933 934
}

935
static int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
936 937
		       gfp_t mask)
{
938 939
	return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0,
				NULL, mask);
940 941 942 943 944 945
}

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,
946
			      NULL, mask);
947 948
}

C
Chris Mason 已提交
949
static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
950 951
				 u64 end, struct extent_state **cached_state,
				 gfp_t mask)
952
{
953
	return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
954
				cached_state, mask);
955 956 957 958 959 960 961
}

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

C
Chris Mason 已提交
962 963 964 965
/*
 * either insert or lock state struct between start and end use mask to tell
 * us if waiting is desired.
 */
966
int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
967
		     int bits, struct extent_state **cached_state, gfp_t mask)
968 969 970 971
{
	int err;
	u64 failed_start;
	while (1) {
972
		err = set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
973 974
				     EXTENT_LOCKED, &failed_start,
				     cached_state, mask);
975 976 977 978 979 980 981 982 983 984 985
		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;
}

986 987
int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
{
988
	return lock_extent_bits(tree, start, end, 0, NULL, mask);
989 990
}

991 992 993 994 995 996
int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
		    gfp_t mask)
{
	int err;
	u64 failed_start;

997 998
	err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
			     &failed_start, NULL, mask);
Y
Yan Zheng 已提交
999 1000 1001
	if (err == -EEXIST) {
		if (failed_start > start)
			clear_extent_bit(tree, start, failed_start - 1,
1002
					 EXTENT_LOCKED, 1, 0, NULL, mask);
1003
		return 0;
Y
Yan Zheng 已提交
1004
	}
1005 1006 1007
	return 1;
}

1008 1009 1010 1011 1012 1013 1014
int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
			 struct extent_state **cached, gfp_t mask)
{
	return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
				mask);
}

1015 1016 1017
int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
		  gfp_t mask)
{
1018 1019
	return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
				mask);
1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043
}

/*
 * 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++;
	}
	return 0;
}

/*
 * helper function to set both pages and extents in the tree writeback
 */
1044
static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059
{
	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++;
	}
	return 0;
}

C
Chris Mason 已提交
1060 1061 1062 1063 1064 1065 1066
/*
 * 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
 */
1067 1068 1069 1070 1071 1072 1073
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;

1074
	spin_lock(&tree->lock);
1075 1076 1077 1078
	/*
	 * this search will find all the extents that end after
	 * our range starts.
	 */
1079
	node = tree_search(tree, start);
C
Chris Mason 已提交
1080
	if (!node)
1081 1082
		goto out;

C
Chris Mason 已提交
1083
	while (1) {
1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095
		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:
1096
	spin_unlock(&tree->lock);
1097 1098 1099
	return ret;
}

C
Chris Mason 已提交
1100 1101 1102 1103
/* 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
1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114
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);
C
Chris Mason 已提交
1115
	if (!node)
C
Chris Mason 已提交
1116 1117
		goto out;

C
Chris Mason 已提交
1118
	while (1) {
C
Chris Mason 已提交
1119
		state = rb_entry(node, struct extent_state, rb_node);
C
Chris Mason 已提交
1120
		if (state->end >= start && (state->state & bits))
C
Chris Mason 已提交
1121
			return state;
C
Chris Mason 已提交
1122

C
Chris Mason 已提交
1123 1124 1125 1126 1127 1128 1129 1130
		node = rb_next(node);
		if (!node)
			break;
	}
out:
	return NULL;
}

C
Chris Mason 已提交
1131 1132 1133 1134 1135 1136
/*
 * 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
1137
static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1138 1139
					u64 *start, u64 *end, u64 max_bytes,
					struct extent_state **cached_state)
1140 1141 1142 1143 1144 1145 1146
{
	struct rb_node *node;
	struct extent_state *state;
	u64 cur_start = *start;
	u64 found = 0;
	u64 total_bytes = 0;

1147
	spin_lock(&tree->lock);
C
Chris Mason 已提交
1148

1149 1150 1151 1152
	/*
	 * this search will find all the extents that end after
	 * our range starts.
	 */
1153
	node = tree_search(tree, cur_start);
1154
	if (!node) {
1155 1156
		if (!found)
			*end = (u64)-1;
1157 1158 1159
		goto out;
	}

C
Chris Mason 已提交
1160
	while (1) {
1161
		state = rb_entry(node, struct extent_state, rb_node);
1162 1163
		if (found && (state->start != cur_start ||
			      (state->state & EXTENT_BOUNDARY))) {
1164 1165 1166 1167 1168 1169 1170
			goto out;
		}
		if (!(state->state & EXTENT_DELALLOC)) {
			if (!found)
				*end = state->end;
			goto out;
		}
1171
		if (!found) {
1172
			*start = state->start;
1173 1174 1175
			*cached_state = state;
			atomic_inc(&state->refs);
		}
1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186
		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:
1187
	spin_unlock(&tree->lock);
1188 1189 1190
	return found;
}

C
Chris Mason 已提交
1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204
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;

C
Chris Mason 已提交
1205
	while (nr_pages > 0) {
C
Chris Mason 已提交
1206
		ret = find_get_pages_contig(inode->i_mapping, index,
1207 1208
				     min_t(unsigned long, nr_pages,
				     ARRAY_SIZE(pages)), pages);
C
Chris Mason 已提交
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
		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;
C
Chris Mason 已提交
1241
	while (nrpages > 0) {
C
Chris Mason 已提交
1242
		ret = find_get_pages_contig(inode->i_mapping, index,
1243 1244
				     min_t(unsigned long,
				     nrpages, ARRAY_SIZE(pages)), pages);
C
Chris Mason 已提交
1245 1246 1247 1248 1249 1250 1251 1252 1253 1254
		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
			 */
1255
			if (pages[i] != locked_page) {
C
Chris Mason 已提交
1256
				lock_page(pages[i]);
1257 1258
				if (!PageDirty(pages[i]) ||
				    pages[i]->mapping != inode->i_mapping) {
1259 1260 1261 1262 1263 1264
					ret = -EAGAIN;
					unlock_page(pages[i]);
					page_cache_release(pages[i]);
					goto done;
				}
			}
C
Chris Mason 已提交
1265
			page_cache_release(pages[i]);
1266
			pages_locked++;
C
Chris Mason 已提交
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
		}
		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;
1298
	struct extent_state *cached_state = NULL;
C
Chris Mason 已提交
1299 1300 1301 1302 1303 1304 1305 1306
	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,
1307
				    max_bytes, &cached_state);
C
Chris Mason 已提交
1308
	if (!found || delalloc_end <= *start) {
C
Chris Mason 已提交
1309 1310
		*start = delalloc_start;
		*end = delalloc_end;
1311
		free_extent_state(cached_state);
C
Chris Mason 已提交
1312 1313 1314
		return found;
	}

C
Chris Mason 已提交
1315 1316 1317 1318 1319
	/*
	 * start comes from the offset of locked_page.  We have to lock
	 * pages in order, so we can't process delalloc bytes before
	 * locked_page
	 */
C
Chris Mason 已提交
1320
	if (delalloc_start < *start)
C
Chris Mason 已提交
1321 1322
		delalloc_start = *start;

C
Chris Mason 已提交
1323 1324 1325 1326
	/*
	 * make sure to limit the number of pages we try to lock down
	 * if we're looping.
	 */
C
Chris Mason 已提交
1327
	if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1328
		delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
C
Chris Mason 已提交
1329

C
Chris Mason 已提交
1330 1331 1332 1333 1334 1335 1336
	/* 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
		 */
1337
		free_extent_state(cached_state);
C
Chris Mason 已提交
1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350
		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 */
1351 1352
	lock_extent_bits(tree, delalloc_start, delalloc_end,
			 0, &cached_state, GFP_NOFS);
C
Chris Mason 已提交
1353 1354 1355

	/* then test to make sure it is all still delalloc */
	ret = test_range_bit(tree, delalloc_start, delalloc_end,
1356
			     EXTENT_DELALLOC, 1, cached_state);
C
Chris Mason 已提交
1357
	if (!ret) {
1358 1359
		unlock_extent_cached(tree, delalloc_start, delalloc_end,
				     &cached_state, GFP_NOFS);
C
Chris Mason 已提交
1360 1361 1362 1363 1364
		__unlock_for_delalloc(inode, locked_page,
			      delalloc_start, delalloc_end);
		cond_resched();
		goto again;
	}
1365
	free_extent_state(cached_state);
C
Chris Mason 已提交
1366 1367 1368 1369 1370 1371 1372 1373 1374
	*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,
1375
				unsigned long op)
C
Chris Mason 已提交
1376 1377 1378 1379 1380 1381 1382
{
	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;
1383
	int clear_bits = 0;
C
Chris Mason 已提交
1384

1385
	if (op & EXTENT_CLEAR_UNLOCK)
1386
		clear_bits |= EXTENT_LOCKED;
1387
	if (op & EXTENT_CLEAR_DIRTY)
C
Chris Mason 已提交
1388 1389
		clear_bits |= EXTENT_DIRTY;

1390
	if (op & EXTENT_CLEAR_DELALLOC)
1391 1392
		clear_bits |= EXTENT_DELALLOC;

1393
	clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1394 1395 1396
	if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
		    EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
		    EXTENT_SET_PRIVATE2)))
1397
		return 0;
C
Chris Mason 已提交
1398

C
Chris Mason 已提交
1399
	while (nr_pages > 0) {
C
Chris Mason 已提交
1400
		ret = find_get_pages_contig(inode->i_mapping, index,
1401 1402
				     min_t(unsigned long,
				     nr_pages, ARRAY_SIZE(pages)), pages);
C
Chris Mason 已提交
1403
		for (i = 0; i < ret; i++) {
1404

1405
			if (op & EXTENT_SET_PRIVATE2)
1406 1407
				SetPagePrivate2(pages[i]);

C
Chris Mason 已提交
1408 1409 1410 1411
			if (pages[i] == locked_page) {
				page_cache_release(pages[i]);
				continue;
			}
1412
			if (op & EXTENT_CLEAR_DIRTY)
C
Chris Mason 已提交
1413
				clear_page_dirty_for_io(pages[i]);
1414
			if (op & EXTENT_SET_WRITEBACK)
C
Chris Mason 已提交
1415
				set_page_writeback(pages[i]);
1416
			if (op & EXTENT_END_WRITEBACK)
C
Chris Mason 已提交
1417
				end_page_writeback(pages[i]);
1418
			if (op & EXTENT_CLEAR_UNLOCK_PAGE)
1419
				unlock_page(pages[i]);
C
Chris Mason 已提交
1420 1421 1422 1423 1424 1425 1426 1427 1428
			page_cache_release(pages[i]);
		}
		nr_pages -= ret;
		index += ret;
		cond_resched();
	}
	return 0;
}

C
Chris Mason 已提交
1429 1430 1431 1432 1433
/*
 * 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.
 */
1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448
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) {
		WARN_ON(1);
		return 0;
	}

1449
	spin_lock(&tree->lock);
1450 1451 1452 1453 1454 1455 1456 1457
	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.
	 */
1458
	node = tree_search(tree, cur_start);
C
Chris Mason 已提交
1459
	if (!node)
1460 1461
		goto out;

C
Chris Mason 已提交
1462
	while (1) {
1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480
		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:
1481
	spin_unlock(&tree->lock);
1482 1483
	return total_bytes;
}
1484

C
Chris Mason 已提交
1485 1486 1487 1488
/*
 * set the private field for a given byte offset in the tree.  If there isn't
 * an extent_state there already, this does nothing.
 */
1489 1490 1491 1492 1493 1494
int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
{
	struct rb_node *node;
	struct extent_state *state;
	int ret = 0;

1495
	spin_lock(&tree->lock);
1496 1497 1498 1499
	/*
	 * this search will find all the extents that end after
	 * our range starts.
	 */
1500
	node = tree_search(tree, start);
1501
	if (!node) {
1502 1503 1504 1505 1506 1507 1508 1509 1510 1511
		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:
1512
	spin_unlock(&tree->lock);
1513 1514 1515 1516 1517 1518 1519 1520 1521
	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;

1522
	spin_lock(&tree->lock);
1523 1524 1525 1526
	/*
	 * this search will find all the extents that end after
	 * our range starts.
	 */
1527
	node = tree_search(tree, start);
1528
	if (!node) {
1529 1530 1531 1532 1533 1534 1535 1536 1537 1538
		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:
1539
	spin_unlock(&tree->lock);
1540 1541 1542 1543 1544
	return ret;
}

/*
 * searches a range in the state tree for a given mask.
1545
 * If 'filled' == 1, this returns 1 only if every extent in the tree
1546 1547 1548 1549
 * 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,
1550
		   int bits, int filled, struct extent_state *cached)
1551 1552 1553 1554 1555
{
	struct extent_state *state = NULL;
	struct rb_node *node;
	int bitset = 0;

1556
	spin_lock(&tree->lock);
1557 1558 1559 1560
	if (cached && cached->tree && cached->start == start)
		node = &cached->rb_node;
	else
		node = tree_search(tree, start);
1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579
	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;
		}
1580 1581 1582 1583

		if (state->end == (u64)-1)
			break;

1584 1585 1586 1587 1588 1589 1590 1591 1592 1593
		start = state->end + 1;
		if (start > end)
			break;
		node = rb_next(node);
		if (!node) {
			if (filled)
				bitset = 0;
			break;
		}
	}
1594
	spin_unlock(&tree->lock);
1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606
	return bitset;
}

/*
 * 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;
1607
	if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620
		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;
1621
	if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632
		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)
{
1633
	end_page_writeback(page);
1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649
	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)
{
1650
	int uptodate = err == 0;
1651
	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1652
	struct extent_io_tree *tree;
1653 1654 1655
	u64 start;
	u64 end;
	int whole_page;
1656
	int ret;
1657 1658 1659

	do {
		struct page *page = bvec->bv_page;
1660 1661
		tree = &BTRFS_I(page->mapping->host)->io_tree;

1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672
		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);
1673 1674
		if (tree->ops && tree->ops->writepage_end_io_hook) {
			ret = tree->ops->writepage_end_io_hook(page, start,
1675
						       end, NULL, uptodate);
1676 1677 1678 1679 1680 1681 1682
			if (ret)
				uptodate = 0;
		}

		if (!uptodate && tree->ops &&
		    tree->ops->writepage_io_failed_hook) {
			ret = tree->ops->writepage_io_failed_hook(bio, page,
1683
							 start, end, NULL);
1684 1685 1686 1687 1688 1689
			if (ret == 0) {
				uptodate = (err == 0);
				continue;
			}
		}

1690
		if (!uptodate) {
1691
			clear_extent_uptodate(tree, start, end, NULL, GFP_NOFS);
1692 1693 1694
			ClearPageUptodate(page);
			SetPageError(page);
		}
1695

1696 1697 1698 1699 1700
		if (whole_page)
			end_page_writeback(page);
		else
			check_page_writeback(tree, page);
	} while (bvec >= bio->bi_io_vec);
1701

1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718
	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);
1719 1720
	struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
	struct bio_vec *bvec = bio->bi_io_vec;
1721
	struct extent_io_tree *tree;
1722 1723 1724 1725 1726
	u64 start;
	u64 end;
	int whole_page;
	int ret;

1727 1728 1729
	if (err)
		uptodate = 0;

1730 1731
	do {
		struct page *page = bvec->bv_page;
1732 1733
		tree = &BTRFS_I(page->mapping->host)->io_tree;

1734 1735 1736 1737 1738 1739 1740 1741 1742
		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;

1743
		if (++bvec <= bvec_end)
1744 1745 1746
			prefetchw(&bvec->bv_page->flags);

		if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
1747
			ret = tree->ops->readpage_end_io_hook(page, start, end,
1748
							      NULL);
1749 1750 1751
			if (ret)
				uptodate = 0;
		}
1752 1753 1754
		if (!uptodate && tree->ops &&
		    tree->ops->readpage_io_failed_hook) {
			ret = tree->ops->readpage_io_failed_hook(bio, page,
1755
							 start, end, NULL);
1756
			if (ret == 0) {
1757 1758
				uptodate =
					test_bit(BIO_UPTODATE, &bio->bi_flags);
1759 1760
				if (err)
					uptodate = 0;
1761 1762 1763
				continue;
			}
		}
1764

1765
		if (uptodate) {
1766 1767
			set_extent_uptodate(tree, start, end,
					    GFP_ATOMIC);
1768
		}
1769
		unlock_extent(tree, start, end, GFP_ATOMIC);
1770

1771 1772 1773 1774 1775 1776 1777
		if (whole_page) {
			if (uptodate) {
				SetPageUptodate(page);
			} else {
				ClearPageUptodate(page);
				SetPageError(page);
			}
1778
			unlock_page(page);
1779 1780 1781 1782 1783 1784 1785
		} else {
			if (uptodate) {
				check_page_uptodate(tree, page);
			} else {
				ClearPageUptodate(page);
				SetPageError(page);
			}
1786
			check_page_locked(tree, page);
1787
		}
1788
	} while (bvec <= bvec_end);
1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801

	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;
1802
	struct extent_io_tree *tree;
1803 1804 1805 1806 1807
	u64 start;
	u64 end;

	do {
		struct page *page = bvec->bv_page;
1808 1809
		tree = &BTRFS_I(page->mapping->host)->io_tree;

1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830
		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);
}

1831 1832 1833
struct bio *
btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
		gfp_t gfp_flags)
1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844
{
	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) {
1845
		bio->bi_size = 0;
1846 1847 1848 1849 1850 1851
		bio->bi_bdev = bdev;
		bio->bi_sector = first_sector;
	}
	return bio;
}

C
Chris Mason 已提交
1852 1853
static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
			  unsigned long bio_flags)
1854 1855
{
	int ret = 0;
1856 1857 1858 1859 1860 1861 1862
	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;

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

1863
	bio->bi_private = NULL;
1864 1865 1866

	bio_get(bio);

1867
	if (tree->ops && tree->ops->submit_bio_hook)
1868
		tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
1869
					   mirror_num, bio_flags, start);
1870 1871
	else
		submit_bio(rw, bio);
1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883
	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,
1884
			      bio_end_io_t end_io_func,
C
Chris Mason 已提交
1885 1886 1887
			      int mirror_num,
			      unsigned long prev_bio_flags,
			      unsigned long bio_flags)
1888 1889 1890 1891
{
	int ret = 0;
	struct bio *bio;
	int nr;
C
Chris Mason 已提交
1892 1893 1894
	int contig = 0;
	int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
	int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
1895
	size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
1896 1897 1898

	if (bio_ret && *bio_ret) {
		bio = *bio_ret;
C
Chris Mason 已提交
1899 1900 1901 1902 1903 1904 1905
		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 ||
1906
		    (tree->ops && tree->ops->merge_bio_hook &&
C
Chris Mason 已提交
1907 1908 1909 1910 1911
		     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);
1912 1913 1914 1915 1916
			bio = NULL;
		} else {
			return 0;
		}
	}
C
Chris Mason 已提交
1917 1918 1919 1920 1921
	if (this_compressed)
		nr = BIO_MAX_PAGES;
	else
		nr = bio_get_nr_vecs(bdev);

1922
	bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
1923

C
Chris Mason 已提交
1924
	bio_add_page(bio, page, page_size, offset);
1925 1926
	bio->bi_end_io = end_io_func;
	bio->bi_private = tree;
1927

C
Chris Mason 已提交
1928
	if (bio_ret)
1929
		*bio_ret = bio;
C
Chris Mason 已提交
1930
	else
C
Chris Mason 已提交
1931
		ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
1932 1933 1934 1935 1936 1937 1938 1939 1940

	return ret;
}

void set_page_extent_mapped(struct page *page)
{
	if (!PagePrivate(page)) {
		SetPagePrivate(page);
		page_cache_get(page);
1941
		set_page_private(page, EXTENT_PAGE_PRIVATE);
1942 1943 1944
	}
}

1945
static void set_page_extent_head(struct page *page, unsigned long len)
1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957
{
	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
1958 1959
				   struct bio **bio, int mirror_num,
				   unsigned long *bio_flags)
1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972
{
	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;
1973
	struct btrfs_ordered_extent *ordered;
1974 1975 1976 1977
	int ret;
	int nr = 0;
	size_t page_offset = 0;
	size_t iosize;
C
Chris Mason 已提交
1978
	size_t disk_io_size;
1979
	size_t blocksize = inode->i_sb->s_blocksize;
C
Chris Mason 已提交
1980
	unsigned long this_bio_flag = 0;
1981 1982 1983 1984

	set_page_extent_mapped(page);

	end = page_end;
1985 1986 1987 1988 1989 1990 1991 1992 1993
	while (1) {
		lock_extent(tree, start, end, GFP_NOFS);
		ordered = btrfs_lookup_ordered_extent(inode, start);
		if (!ordered)
			break;
		unlock_extent(tree, start, end, GFP_NOFS);
		btrfs_start_ordered_extent(inode, ordered, 1);
		btrfs_put_ordered_extent(ordered);
	}
1994

C
Chris Mason 已提交
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
	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);
		}
	}
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
	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;
		BUG_ON(extent_map_end(em) <= cur);
		BUG_ON(end < cur);

2031
		if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
C
Chris Mason 已提交
2032
			this_bio_flag = EXTENT_BIO_COMPRESSED;
2033 2034 2035
			extent_set_compress_type(&this_bio_flag,
						 em->compress_type);
		}
C
Chris Mason 已提交
2036

2037 2038 2039
		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
2040 2041 2042 2043 2044 2045 2046
		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;
		}
2047 2048
		bdev = em->bdev;
		block_start = em->block_start;
Y
Yan Zheng 已提交
2049 2050
		if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
			block_start = EXTENT_MAP_HOLE;
2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069
		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 */
2070 2071
		if (test_range_bit(tree, cur, cur_end,
				   EXTENT_UPTODATE, 1, NULL)) {
2072
			check_page_uptodate(tree, page);
2073 2074 2075 2076 2077
			unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
			cur = cur + iosize;
			page_offset += iosize;
			continue;
		}
2078 2079 2080 2081 2082 2083 2084 2085 2086 2087
		/* 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;
		}
2088 2089 2090 2091 2092 2093 2094

		ret = 0;
		if (tree->ops && tree->ops->readpage_io_hook) {
			ret = tree->ops->readpage_io_hook(page, cur,
							  cur + iosize - 1);
		}
		if (!ret) {
2095 2096
			unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
			pnr -= page->index;
2097
			ret = submit_extent_page(READ, tree, page,
C
Chris Mason 已提交
2098
					 sector, disk_io_size, page_offset,
2099
					 bdev, bio, pnr,
C
Chris Mason 已提交
2100 2101 2102
					 end_bio_extent_readpage, mirror_num,
					 *bio_flags,
					 this_bio_flag);
2103
			nr++;
C
Chris Mason 已提交
2104
			*bio_flags = this_bio_flag;
2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122
		}
		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
2123
	unsigned long bio_flags = 0;
2124 2125
	int ret;

C
Chris Mason 已提交
2126 2127
	ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
				      &bio_flags);
2128
	if (bio)
C
Chris Mason 已提交
2129
		submit_one_bio(READ, bio, 0, bio_flags);
2130 2131 2132
	return ret;
}

2133 2134 2135 2136 2137 2138 2139 2140 2141 2142
static noinline void update_nr_written(struct page *page,
				      struct writeback_control *wbc,
				      unsigned long nr_written)
{
	wbc->nr_to_write -= nr_written;
	if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
	    wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
		page->mapping->writeback_index = page->index + nr_written;
}

2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164
/*
 * 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;
	sector_t sector;
2165
	struct extent_state *cached_state = NULL;
2166 2167 2168 2169
	struct extent_map *em;
	struct block_device *bdev;
	int ret;
	int nr = 0;
2170
	size_t pg_offset = 0;
2171 2172 2173 2174 2175
	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
2176 2177
	int page_started;
	int compressed;
2178
	int write_flags;
2179
	unsigned long nr_written = 0;
2180

2181 2182 2183 2184 2185
	if (wbc->sync_mode == WB_SYNC_ALL)
		write_flags = WRITE_SYNC_PLUG;
	else
		write_flags = WRITE;

2186
	WARN_ON(!PageLocked(page));
2187
	pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2188
	if (page->index > end_index ||
2189
	   (page->index == end_index && !pg_offset)) {
2190
		page->mapping->a_ops->invalidatepage(page, 0);
2191 2192 2193 2194 2195 2196 2197 2198
		unlock_page(page);
		return 0;
	}

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

		userpage = kmap_atomic(page, KM_USER0);
2199 2200
		memset(userpage + pg_offset, 0,
		       PAGE_CACHE_SIZE - pg_offset);
2201
		kunmap_atomic(userpage, KM_USER0);
2202
		flush_dcache_page(page);
2203
	}
2204
	pg_offset = 0;
2205 2206 2207 2208 2209

	set_page_extent_mapped(page);

	delalloc_start = start;
	delalloc_end = 0;
C
Chris Mason 已提交
2210
	page_started = 0;
2211
	if (!epd->extent_locked) {
2212
		u64 delalloc_to_write = 0;
2213 2214 2215 2216 2217 2218
		/*
		 * make sure the wbc mapping index is at least updated
		 * to this page.
		 */
		update_nr_written(page, wbc, 0);

C
Chris Mason 已提交
2219
		while (delalloc_end < page_end) {
2220
			nr_delalloc = find_lock_delalloc_range(inode, tree,
C
Chris Mason 已提交
2221 2222
						       page,
						       &delalloc_start,
2223 2224
						       &delalloc_end,
						       128 * 1024 * 1024);
2225 2226 2227 2228 2229 2230 2231
			if (nr_delalloc == 0) {
				delalloc_start = delalloc_end + 1;
				continue;
			}
			tree->ops->fill_delalloc(inode, page, delalloc_start,
						 delalloc_end, &page_started,
						 &nr_written);
2232 2233 2234 2235 2236 2237 2238 2239
			/*
			 * delalloc_end is already one less than the total
			 * length, so we don't subtract one from
			 * PAGE_CACHE_SIZE
			 */
			delalloc_to_write += (delalloc_end - delalloc_start +
					      PAGE_CACHE_SIZE) >>
					      PAGE_CACHE_SHIFT;
2240 2241
			delalloc_start = delalloc_end + 1;
		}
2242 2243 2244 2245 2246 2247 2248 2249
		if (wbc->nr_to_write < delalloc_to_write) {
			int thresh = 8192;

			if (delalloc_to_write < thresh * 2)
				thresh = delalloc_to_write;
			wbc->nr_to_write = min_t(u64, delalloc_to_write,
						 thresh);
		}
C
Chris Mason 已提交
2250

2251 2252 2253 2254 2255
		/* did the fill delalloc function already unlock and start
		 * the IO?
		 */
		if (page_started) {
			ret = 0;
2256 2257 2258 2259 2260 2261 2262
			/*
			 * we've unlocked the page, so we can't update
			 * the mapping's writeback index, just update
			 * nr_to_write.
			 */
			wbc->nr_to_write -= nr_written;
			goto done_unlocked;
2263
		}
C
Chris Mason 已提交
2264
	}
2265
	if (tree->ops && tree->ops->writepage_start_hook) {
C
Chris Mason 已提交
2266 2267
		ret = tree->ops->writepage_start_hook(page, start,
						      page_end);
2268 2269
		if (ret == -EAGAIN) {
			redirty_page_for_writepage(wbc, page);
2270
			update_nr_written(page, wbc, nr_written);
2271
			unlock_page(page);
2272
			ret = 0;
2273
			goto done_unlocked;
2274 2275 2276
		}
	}

2277 2278 2279 2280 2281
	/*
	 * we don't want to touch the inode after unlocking the page,
	 * so we update the mapping writeback index now
	 */
	update_nr_written(page, wbc, nr_written + 1);
2282

2283 2284
	end = page_end;
	if (last_byte <= start) {
2285 2286 2287
		if (tree->ops && tree->ops->writepage_end_io_hook)
			tree->ops->writepage_end_io_hook(page, start,
							 page_end, NULL, 1);
2288 2289 2290 2291 2292 2293 2294
		goto done;
	}

	blocksize = inode->i_sb->s_blocksize;

	while (cur <= end) {
		if (cur >= last_byte) {
2295 2296 2297
			if (tree->ops && tree->ops->writepage_end_io_hook)
				tree->ops->writepage_end_io_hook(page, cur,
							 page_end, NULL, 1);
2298 2299
			break;
		}
2300
		em = epd->get_extent(inode, page, pg_offset, cur,
2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314
				     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
2315
		compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2316 2317 2318
		free_extent_map(em);
		em = NULL;

C
Chris Mason 已提交
2319 2320 2321 2322 2323
		/*
		 * compressed and inline extents are written through other
		 * paths in the FS
		 */
		if (compressed || block_start == EXTENT_MAP_HOLE ||
2324
		    block_start == EXTENT_MAP_INLINE) {
C
Chris Mason 已提交
2325 2326 2327 2328 2329 2330
			/*
			 * end_io notification does not happen here for
			 * compressed extents
			 */
			if (!compressed && tree->ops &&
			    tree->ops->writepage_end_io_hook)
2331 2332 2333
				tree->ops->writepage_end_io_hook(page, cur,
							 cur + iosize - 1,
							 NULL, 1);
C
Chris Mason 已提交
2334 2335 2336 2337 2338 2339 2340 2341 2342
			else if (compressed) {
				/* we don't want to end_page_writeback on
				 * a compressed extent.  this happens
				 * elsewhere
				 */
				nr++;
			}

			cur += iosize;
2343
			pg_offset += iosize;
2344 2345 2346 2347
			continue;
		}
		/* leave this out until we have a page_mkwrite call */
		if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
2348
				   EXTENT_DIRTY, 0, NULL)) {
2349
			cur = cur + iosize;
2350
			pg_offset += iosize;
2351 2352
			continue;
		}
C
Chris Mason 已提交
2353

2354 2355 2356 2357 2358 2359
		if (tree->ops && tree->ops->writepage_io_hook) {
			ret = tree->ops->writepage_io_hook(page, cur,
						cur + iosize - 1);
		} else {
			ret = 0;
		}
2360
		if (ret) {
2361
			SetPageError(page);
2362
		} else {
2363
			unsigned long max_nr = end_index + 1;
2364

2365 2366
			set_range_writeback(tree, cur, cur + iosize - 1);
			if (!PageWriteback(page)) {
C
Chris Mason 已提交
2367 2368 2369
				printk(KERN_ERR "btrfs warning page %lu not "
				       "writeback, cur %llu end %llu\n",
				       page->index, (unsigned long long)cur,
2370 2371 2372
				       (unsigned long long)end);
			}

2373 2374 2375
			ret = submit_extent_page(write_flags, tree, page,
						 sector, iosize, pg_offset,
						 bdev, &epd->bio, max_nr,
C
Chris Mason 已提交
2376 2377
						 end_bio_extent_writepage,
						 0, 0, 0);
2378 2379 2380 2381
			if (ret)
				SetPageError(page);
		}
		cur = cur + iosize;
2382
		pg_offset += iosize;
2383 2384 2385 2386 2387 2388 2389 2390 2391
		nr++;
	}
done:
	if (nr == 0) {
		/* make sure the mapping tag for page dirty gets cleared */
		set_page_writeback(page);
		end_page_writeback(page);
	}
	unlock_page(page);
2392

2393 2394
done_unlocked:

2395 2396
	/* drop our reference on any cached states */
	free_extent_state(cached_state);
2397 2398 2399 2400
	return 0;
}

/**
C
Chris Mason 已提交
2401
 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414
 * @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.
 */
2415
static int extent_write_cache_pages(struct extent_io_tree *tree,
C
Chris Mason 已提交
2416 2417
			     struct address_space *mapping,
			     struct writeback_control *wbc,
C
Chris Mason 已提交
2418 2419
			     writepage_t writepage, void *data,
			     void (*flush_fn)(void *))
2420 2421 2422
{
	int ret = 0;
	int done = 0;
2423
	int nr_to_write_done = 0;
2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439
	struct pagevec pvec;
	int nr_pages;
	pgoff_t index;
	pgoff_t end;		/* Inclusive */
	int scanned = 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;
		scanned = 1;
	}
retry:
2440
	while (!done && !nr_to_write_done && (index <= end) &&
2441
	       (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
C
Chris Mason 已提交
2442 2443
			      PAGECACHE_TAG_DIRTY, min(end - index,
				  (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456
		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
2457 2458 2459 2460
			if (tree->ops && tree->ops->write_cache_pages_lock_hook)
				tree->ops->write_cache_pages_lock_hook(page);
			else
				lock_page(page);
2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472

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

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

C
Chris Mason 已提交
2473
			if (wbc->sync_mode != WB_SYNC_NONE) {
2474 2475
				if (PageWriteback(page))
					flush_fn(data);
2476
				wait_on_page_writeback(page);
C
Chris Mason 已提交
2477
			}
2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490

			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;
			}
2491
			if (ret)
2492
				done = 1;
2493 2494 2495 2496 2497 2498 2499

			/*
			 * the filesystem may choose to bump up nr_to_write.
			 * We have to make sure to honor the new nr_to_write
			 * at any time
			 */
			nr_to_write_done = wbc->nr_to_write <= 0;
2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515
		}
		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;
	}
	return ret;
}

2516
static void flush_epd_write_bio(struct extent_page_data *epd)
C
Chris Mason 已提交
2517 2518
{
	if (epd->bio) {
2519 2520 2521 2522
		if (epd->sync_io)
			submit_one_bio(WRITE_SYNC, epd->bio, 0, 0);
		else
			submit_one_bio(WRITE, epd->bio, 0, 0);
C
Chris Mason 已提交
2523 2524 2525 2526
		epd->bio = NULL;
	}
}

2527 2528 2529 2530 2531 2532
static noinline void flush_write_bio(void *data)
{
	struct extent_page_data *epd = data;
	flush_epd_write_bio(epd);
}

2533 2534 2535 2536 2537 2538 2539 2540 2541 2542
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,
2543
		.extent_locked = 0,
2544
		.sync_io = wbc->sync_mode == WB_SYNC_ALL,
2545 2546
	};
	struct writeback_control wbc_writepages = {
2547
		.sync_mode	= wbc->sync_mode,
2548 2549 2550 2551 2552 2553 2554 2555
		.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
2556
	extent_write_cache_pages(tree, mapping, &wbc_writepages,
C
Chris Mason 已提交
2557
				 __extent_writepage, &epd, flush_write_bio);
2558
	flush_epd_write_bio(&epd);
2559 2560 2561
	return ret;
}

2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576
int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
			      u64 start, u64 end, get_extent_t *get_extent,
			      int mode)
{
	int ret = 0;
	struct address_space *mapping = inode->i_mapping;
	struct page *page;
	unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
		PAGE_CACHE_SHIFT;

	struct extent_page_data epd = {
		.bio = NULL,
		.tree = tree,
		.get_extent = get_extent,
		.extent_locked = 1,
2577
		.sync_io = mode == WB_SYNC_ALL,
2578 2579 2580 2581 2582 2583 2584 2585 2586
	};
	struct writeback_control wbc_writepages = {
		.sync_mode	= mode,
		.older_than_this = NULL,
		.nr_to_write	= nr_pages * 2,
		.range_start	= start,
		.range_end	= end + 1,
	};

C
Chris Mason 已提交
2587
	while (start <= end) {
2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601
		page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
		if (clear_page_dirty_for_io(page))
			ret = __extent_writepage(page, &wbc_writepages, &epd);
		else {
			if (tree->ops && tree->ops->writepage_end_io_hook)
				tree->ops->writepage_end_io_hook(page, start,
						 start + PAGE_CACHE_SIZE - 1,
						 NULL, 1);
			unlock_page(page);
		}
		page_cache_release(page);
		start += PAGE_CACHE_SIZE;
	}

2602
	flush_epd_write_bio(&epd);
2603 2604
	return ret;
}
2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615

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,
2616
		.extent_locked = 0,
2617
		.sync_io = wbc->sync_mode == WB_SYNC_ALL,
2618 2619
	};

C
Chris Mason 已提交
2620
	ret = extent_write_cache_pages(tree, mapping, wbc,
C
Chris Mason 已提交
2621 2622
				       __extent_writepage, &epd,
				       flush_write_bio);
2623
	flush_epd_write_bio(&epd);
2624 2625 2626 2627 2628 2629 2630 2631 2632 2633
	return ret;
}

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;
C
Chris Mason 已提交
2634
	unsigned long bio_flags = 0;
2635 2636 2637 2638 2639 2640

	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);
2641
		if (!add_to_page_cache_lru(page, mapping,
2642
					page->index, GFP_KERNEL)) {
2643
			__extent_read_full_page(tree, page, get_extent,
C
Chris Mason 已提交
2644
						&bio, 0, &bio_flags);
2645 2646 2647 2648 2649
		}
		page_cache_release(page);
	}
	BUG_ON(!list_empty(pages));
	if (bio)
C
Chris Mason 已提交
2650
		submit_one_bio(READ, bio, 0, bio_flags);
2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661
	return 0;
}

/*
 * 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)
{
2662
	struct extent_state *cached_state = NULL;
2663 2664 2665 2666
	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;

C
Chris Mason 已提交
2667
	start += (offset + blocksize - 1) & ~(blocksize - 1);
2668 2669 2670
	if (start > end)
		return 0;

2671
	lock_extent_bits(tree, start, end, 0, &cached_state, GFP_NOFS);
2672
	wait_on_page_writeback(page);
2673
	clear_extent_bit(tree, start, end,
2674 2675
			 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
			 EXTENT_DO_ACCOUNTING,
2676
			 1, 1, &cached_state, GFP_NOFS);
2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726
	return 0;
}

/*
 * 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;
}

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);
C
Chris Mason 已提交
2727
	while (block_start <= block_end) {
2728 2729
		em = get_extent(inode, page, page_offset, block_start,
				block_end - block_start + 1, 1);
C
Chris Mason 已提交
2730
		if (IS_ERR(em) || !em)
2731
			goto err;
C
Chris Mason 已提交
2732

2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755
		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,
2756
				    EXTENT_UPTODATE, 1, NULL)) {
2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769
			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,
2770
				       EXTENT_LOCKED, 0, NULL, NULL, GFP_NOFS);
2771 2772 2773
			ret = submit_extent_page(READ, tree, page,
					 sector, iosize, page_offset, em->bdev,
					 NULL, 1,
C
Chris Mason 已提交
2774 2775
					 end_bio_extent_preparewrite, 0,
					 0, 0);
2776 2777
			if (ret && !err)
				err = ret;
2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798
			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;
}

2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811
/*
 * 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;

2812
	if (test_range_bit(tree, start, end,
2813
			   EXTENT_IOBITS, 0, NULL))
2814 2815 2816 2817
		ret = 0;
	else {
		if ((mask & GFP_NOFS) == GFP_NOFS)
			mask = GFP_NOFS;
2818 2819 2820 2821 2822 2823 2824
		/*
		 * at this point we can safely clear everything except the
		 * locked bit and the nodatasum bit
		 */
		clear_extent_bit(tree, start, end,
				 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
				 0, 0, NULL, mask);
2825 2826 2827 2828
	}
	return ret;
}

2829 2830 2831 2832 2833 2834
/*
 * 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,
2835 2836
			       struct extent_io_tree *tree, struct page *page,
			       gfp_t mask)
2837 2838 2839 2840
{
	struct extent_map *em;
	u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
	u64 end = start + PAGE_CACHE_SIZE - 1;
2841

2842 2843
	if ((mask & __GFP_WAIT) &&
	    page->mapping->host->i_size > 16 * 1024 * 1024) {
2844
		u64 len;
2845
		while (start <= end) {
2846
			len = end - start + 1;
2847
			write_lock(&map->lock);
2848
			em = lookup_extent_mapping(map, start, len);
2849
			if (!em || IS_ERR(em)) {
2850
				write_unlock(&map->lock);
2851 2852
				break;
			}
2853 2854
			if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
			    em->start != start) {
2855
				write_unlock(&map->lock);
2856 2857 2858 2859 2860
				free_extent_map(em);
				break;
			}
			if (!test_range_bit(tree, em->start,
					    extent_map_end(em) - 1,
2861
					    EXTENT_LOCKED | EXTENT_WRITEBACK,
2862
					    0, NULL)) {
2863 2864 2865 2866 2867
				remove_extent_mapping(map, em);
				/* once for the rb tree */
				free_extent_map(em);
			}
			start = extent_map_end(em);
2868
			write_unlock(&map->lock);
2869 2870

			/* once for us */
2871 2872 2873
			free_extent_map(em);
		}
	}
2874
	return try_release_extent_state(map, tree, page, mask);
2875 2876 2877 2878 2879 2880
}

sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
		get_extent_t *get_extent)
{
	struct inode *inode = mapping->host;
2881
	struct extent_state *cached_state = NULL;
2882 2883
	u64 start = iblock << inode->i_blkbits;
	sector_t sector = 0;
Y
Yan Zheng 已提交
2884
	size_t blksize = (1 << inode->i_blkbits);
2885 2886
	struct extent_map *em;

2887 2888
	lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
			 0, &cached_state, GFP_NOFS);
Y
Yan Zheng 已提交
2889
	em = get_extent(inode, NULL, 0, start, blksize, 0);
2890 2891
	unlock_extent_cached(&BTRFS_I(inode)->io_tree, start,
			     start + blksize - 1, &cached_state, GFP_NOFS);
2892 2893 2894
	if (!em || IS_ERR(em))
		return 0;

Y
Yan Zheng 已提交
2895
	if (em->block_start > EXTENT_MAP_LAST_BYTE)
2896 2897 2898 2899 2900 2901 2902 2903
		goto out;

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

Y
Yehuda Sadeh 已提交
2904 2905 2906
int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
		__u64 start, __u64 len, get_extent_t *get_extent)
{
J
Josef Bacik 已提交
2907
	int ret = 0;
Y
Yehuda Sadeh 已提交
2908 2909 2910
	u64 off = start;
	u64 max = start + len;
	u32 flags = 0;
J
Josef Bacik 已提交
2911 2912
	u32 found_type;
	u64 last;
Y
Yehuda Sadeh 已提交
2913
	u64 disko = 0;
J
Josef Bacik 已提交
2914
	struct btrfs_key found_key;
Y
Yehuda Sadeh 已提交
2915
	struct extent_map *em = NULL;
2916
	struct extent_state *cached_state = NULL;
J
Josef Bacik 已提交
2917 2918
	struct btrfs_path *path;
	struct btrfs_file_extent_item *item;
Y
Yehuda Sadeh 已提交
2919 2920 2921
	int end = 0;
	u64 em_start = 0, em_len = 0;
	unsigned long emflags;
J
Josef Bacik 已提交
2922
	int hole = 0;
Y
Yehuda Sadeh 已提交
2923 2924 2925 2926

	if (len == 0)
		return -EINVAL;

J
Josef Bacik 已提交
2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953
	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
	path->leave_spinning = 1;

	ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
				       path, inode->i_ino, -1, 0);
	if (ret < 0) {
		btrfs_free_path(path);
		return ret;
	}
	WARN_ON(!ret);
	path->slots[0]--;
	item = btrfs_item_ptr(path->nodes[0], path->slots[0],
			      struct btrfs_file_extent_item);
	btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
	found_type = btrfs_key_type(&found_key);

	/* No extents, just return */
	if (found_key.objectid != inode->i_ino ||
	    found_type != BTRFS_EXTENT_DATA_KEY) {
		btrfs_free_path(path);
		return 0;
	}
	last = found_key.offset;
	btrfs_free_path(path);

2954 2955
	lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
			 &cached_state, GFP_NOFS);
Y
Yehuda Sadeh 已提交
2956 2957 2958 2959 2960 2961 2962
	em = get_extent(inode, NULL, 0, off, max - off, 0);
	if (!em)
		goto out;
	if (IS_ERR(em)) {
		ret = PTR_ERR(em);
		goto out;
	}
J
Josef Bacik 已提交
2963

Y
Yehuda Sadeh 已提交
2964
	while (!end) {
J
Josef Bacik 已提交
2965
		hole = 0;
Y
Yehuda Sadeh 已提交
2966 2967 2968 2969
		off = em->start + em->len;
		if (off >= max)
			end = 1;

J
Josef Bacik 已提交
2970 2971 2972 2973 2974
		if (em->block_start == EXTENT_MAP_HOLE) {
			hole = 1;
			goto next;
		}

Y
Yehuda Sadeh 已提交
2975 2976 2977 2978 2979 2980
		em_start = em->start;
		em_len = em->len;

		disko = 0;
		flags = 0;

2981
		if (em->block_start == EXTENT_MAP_LAST_BYTE) {
Y
Yehuda Sadeh 已提交
2982 2983
			end = 1;
			flags |= FIEMAP_EXTENT_LAST;
2984
		} else if (em->block_start == EXTENT_MAP_INLINE) {
Y
Yehuda Sadeh 已提交
2985 2986
			flags |= (FIEMAP_EXTENT_DATA_INLINE |
				  FIEMAP_EXTENT_NOT_ALIGNED);
2987
		} else if (em->block_start == EXTENT_MAP_DELALLOC) {
Y
Yehuda Sadeh 已提交
2988 2989
			flags |= (FIEMAP_EXTENT_DELALLOC |
				  FIEMAP_EXTENT_UNKNOWN);
2990
		} else {
Y
Yehuda Sadeh 已提交
2991 2992 2993 2994 2995
			disko = em->block_start;
		}
		if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
			flags |= FIEMAP_EXTENT_ENCODED;

J
Josef Bacik 已提交
2996
next:
Y
Yehuda Sadeh 已提交
2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009
		emflags = em->flags;
		free_extent_map(em);
		em = NULL;
		if (!end) {
			em = get_extent(inode, NULL, 0, off, max - off, 0);
			if (!em)
				goto out;
			if (IS_ERR(em)) {
				ret = PTR_ERR(em);
				goto out;
			}
			emflags = em->flags;
		}
J
Josef Bacik 已提交
3010

Y
Yehuda Sadeh 已提交
3011 3012 3013 3014 3015
		if (test_bit(EXTENT_FLAG_VACANCY, &emflags)) {
			flags |= FIEMAP_EXTENT_LAST;
			end = 1;
		}

J
Josef Bacik 已提交
3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026
		if (em_start == last) {
			flags |= FIEMAP_EXTENT_LAST;
			end = 1;
		}

		if (!hole) {
			ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
						em_len, flags);
			if (ret)
				goto out_free;
		}
Y
Yehuda Sadeh 已提交
3027 3028 3029 3030
	}
out_free:
	free_extent_map(em);
out:
3031 3032
	unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len,
			     &cached_state, GFP_NOFS);
Y
Yehuda Sadeh 已提交
3033 3034 3035
	return ret;
}

3036 3037 3038 3039 3040 3041 3042 3043 3044 3045
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
3046 3047
	if (!mapping)
		return NULL;
3048 3049 3050 3051 3052 3053 3054

	/*
	 * 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();
3055
	p = radix_tree_lookup(&mapping->page_tree, i);
3056
	rcu_read_unlock();
3057

3058 3059 3060
	return p;
}

3061
static inline unsigned long num_extent_pages(u64 start, u64 len)
3062
{
3063 3064
	return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
		(start >> PAGE_CACHE_SHIFT);
3065 3066
}

3067 3068 3069 3070 3071 3072
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;
3073
#if LEAK_DEBUG
3074
	unsigned long flags;
C
Chris Mason 已提交
3075
#endif
3076 3077

	eb = kmem_cache_zalloc(extent_buffer_cache, mask);
T
Tsutomu Itoh 已提交
3078 3079
	if (eb == NULL)
		return NULL;
3080 3081
	eb->start = start;
	eb->len = len;
3082 3083
	spin_lock_init(&eb->lock);
	init_waitqueue_head(&eb->lock_wq);
3084
	INIT_RCU_HEAD(&eb->rcu_head);
3085

3086
#if LEAK_DEBUG
3087 3088 3089
	spin_lock_irqsave(&leak_lock, flags);
	list_add(&eb->leak_list, &buffers);
	spin_unlock_irqrestore(&leak_lock, flags);
C
Chris Mason 已提交
3090
#endif
3091 3092 3093 3094 3095 3096 3097
	atomic_set(&eb->refs, 1);

	return eb;
}

static void __free_extent_buffer(struct extent_buffer *eb)
{
3098
#if LEAK_DEBUG
3099 3100 3101 3102
	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
3103
#endif
3104 3105 3106
	kmem_cache_free(extent_buffer_cache, eb);
}

3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139
/*
 * Helper for releasing extent buffer page.
 */
static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
						unsigned long start_idx)
{
	unsigned long index;
	struct page *page;

	if (!eb->first_page)
		return;

	index = num_extent_pages(eb->start, eb->len);
	if (start_idx >= index)
		return;

	do {
		index--;
		page = extent_buffer_page(eb, index);
		if (page)
			page_cache_release(page);
	} while (index != start_idx);
}

/*
 * Helper for releasing the extent buffer.
 */
static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
{
	btrfs_release_extent_buffer_page(eb, 0);
	__free_extent_buffer(eb);
}

3140 3141 3142 3143 3144 3145 3146 3147 3148
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;
3149
	struct extent_buffer *exists = NULL;
3150 3151 3152
	struct page *p;
	struct address_space *mapping = tree->mapping;
	int uptodate = 1;
3153
	int ret;
3154

3155 3156 3157 3158
	rcu_read_lock();
	eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
	if (eb && atomic_inc_not_zero(&eb->refs)) {
		rcu_read_unlock();
J
Josef Bacik 已提交
3159
		mark_page_accessed(eb->first_page);
3160 3161
		return eb;
	}
3162
	rcu_read_unlock();
3163

3164
	eb = __alloc_extent_buffer(tree, start, len, mask);
3165
	if (!eb)
3166 3167 3168 3169 3170 3171 3172 3173 3174 3175
		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);
3176
		uptodate = PageUptodate(page0);
3177 3178 3179 3180 3181 3182 3183
	} else {
		i = 0;
	}
	for (; i < num_pages; i++, index++) {
		p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
		if (!p) {
			WARN_ON(1);
3184
			goto free_eb;
3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198
		}
		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)
3199
		set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3200

3201 3202 3203 3204
	ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
	if (ret)
		goto free_eb;

3205
	spin_lock(&tree->buffer_lock);
3206 3207 3208 3209
	ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
	if (ret == -EEXIST) {
		exists = radix_tree_lookup(&tree->buffer,
						start >> PAGE_CACHE_SHIFT);
3210 3211 3212
		/* add one reference for the caller */
		atomic_inc(&exists->refs);
		spin_unlock(&tree->buffer_lock);
3213
		radix_tree_preload_end();
3214 3215 3216 3217
		goto free_eb;
	}
	/* add one reference for the tree */
	atomic_inc(&eb->refs);
3218
	spin_unlock(&tree->buffer_lock);
3219
	radix_tree_preload_end();
3220 3221
	return eb;

3222
free_eb:
3223
	if (!atomic_dec_and_test(&eb->refs))
3224
		return exists;
3225
	btrfs_release_extent_buffer(eb);
3226
	return exists;
3227 3228 3229 3230 3231 3232 3233 3234
}

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

3235 3236 3237 3238
	rcu_read_lock();
	eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
	if (eb && atomic_inc_not_zero(&eb->refs)) {
		rcu_read_unlock();
J
Josef Bacik 已提交
3239
		mark_page_accessed(eb->first_page);
3240 3241 3242
		return eb;
	}
	rcu_read_unlock();
J
Josef Bacik 已提交
3243

3244
	return NULL;
3245 3246 3247 3248 3249 3250 3251 3252 3253 3254
}

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

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

3255
	WARN_ON(1);
3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268
}

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

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

	for (i = 0; i < num_pages; i++) {
		page = extent_buffer_page(eb, i);
3269
		if (!PageDirty(page))
C
Chris Mason 已提交
3270 3271
			continue;

3272
		lock_page(page);
3273 3274 3275 3276 3277 3278
		if (i == 0)
			set_page_extent_head(page, eb->len);
		else
			set_page_private(page, EXTENT_PAGE_PRIVATE);

		clear_page_dirty_for_io(page);
3279
		spin_lock_irq(&page->mapping->tree_lock);
3280 3281 3282 3283 3284
		if (!PageDirty(page)) {
			radix_tree_tag_clear(&page->mapping->page_tree,
						page_index(page),
						PAGECACHE_TAG_DIRTY);
		}
3285
		spin_unlock_irq(&page->mapping->tree_lock);
3286
		unlock_page(page);
3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302
	}
	return 0;
}

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);
}

int set_extent_buffer_dirty(struct extent_io_tree *tree,
			     struct extent_buffer *eb)
{
	unsigned long i;
	unsigned long num_pages;
3303
	int was_dirty = 0;
3304

3305
	was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
3306
	num_pages = num_extent_pages(eb->start, eb->len);
3307
	for (i = 0; i < num_pages; i++)
3308
		__set_page_dirty_nobuffers(extent_buffer_page(eb, i));
3309
	return was_dirty;
3310 3311
}

3312
int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
3313 3314
				struct extent_buffer *eb,
				struct extent_state **cached_state)
3315 3316 3317 3318 3319 3320
{
	unsigned long i;
	struct page *page;
	unsigned long num_pages;

	num_pages = num_extent_pages(eb->start, eb->len);
3321
	clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3322 3323

	clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3324
			      cached_state, GFP_NOFS);
3325 3326
	for (i = 0; i < num_pages; i++) {
		page = extent_buffer_page(eb, i);
C
Chris Mason 已提交
3327 3328
		if (page)
			ClearPageUptodate(page);
3329 3330 3331 3332
	}
	return 0;
}

3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356
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;
}

3357 3358 3359 3360 3361 3362 3363 3364 3365
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;

3366
	ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL);
3367 3368
	if (ret)
		return 1;
C
Chris Mason 已提交
3369
	while (start <= end) {
3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382
		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;
}

3383
int extent_buffer_uptodate(struct extent_io_tree *tree,
3384 3385
			   struct extent_buffer *eb,
			   struct extent_state *cached_state)
3386
{
3387
	int ret = 0;
3388 3389
	unsigned long num_pages;
	unsigned long i;
3390 3391 3392
	struct page *page;
	int pg_uptodate = 1;

3393
	if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
C
Chris Mason 已提交
3394
		return 1;
3395

C
Chris Mason 已提交
3396
	ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3397
			   EXTENT_UPTODATE, 1, cached_state);
C
Chris Mason 已提交
3398 3399
	if (ret)
		return ret;
3400 3401 3402 3403 3404 3405 3406 3407 3408

	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
3409
	return pg_uptodate;
3410 3411 3412 3413
}

int read_extent_buffer_pages(struct extent_io_tree *tree,
			     struct extent_buffer *eb,
3414
			     u64 start, int wait,
3415
			     get_extent_t *get_extent, int mirror_num)
3416 3417 3418 3419 3420 3421
{
	unsigned long i;
	unsigned long start_i;
	struct page *page;
	int err;
	int ret = 0;
3422 3423 3424
	int locked_pages = 0;
	int all_uptodate = 1;
	int inc_all_pages = 0;
3425
	unsigned long num_pages;
3426
	struct bio *bio = NULL;
C
Chris Mason 已提交
3427
	unsigned long bio_flags = 0;
3428

3429
	if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3430 3431
		return 0;

3432
	if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3433
			   EXTENT_UPTODATE, 1, NULL)) {
3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448
		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) {
3449
			if (!trylock_page(page))
3450
				goto unlock_exit;
3451 3452 3453
		} else {
			lock_page(page);
		}
3454
		locked_pages++;
C
Chris Mason 已提交
3455
		if (!PageUptodate(page))
3456 3457 3458 3459
			all_uptodate = 0;
	}
	if (all_uptodate) {
		if (start_i == 0)
3460
			set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3461 3462 3463 3464 3465 3466 3467 3468 3469 3470
		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;
3471
			ClearPageError(page);
3472
			err = __extent_read_full_page(tree, page,
3473
						      get_extent, &bio,
C
Chris Mason 已提交
3474
						      mirror_num, &bio_flags);
C
Chris Mason 已提交
3475
			if (err)
3476 3477 3478 3479 3480 3481
				ret = err;
		} else {
			unlock_page(page);
		}
	}

3482
	if (bio)
C
Chris Mason 已提交
3483
		submit_one_bio(READ, bio, mirror_num, bio_flags);
3484

C
Chris Mason 已提交
3485
	if (ret || !wait)
3486
		return ret;
C
Chris Mason 已提交
3487

3488 3489 3490
	for (i = start_i; i < num_pages; i++) {
		page = extent_buffer_page(eb, i);
		wait_on_page_locked(page);
C
Chris Mason 已提交
3491
		if (!PageUptodate(page))
3492 3493
			ret = -EIO;
	}
C
Chris Mason 已提交
3494

3495
	if (!ret)
3496
		set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3497
	return ret;
3498 3499 3500

unlock_exit:
	i = start_i;
C
Chris Mason 已提交
3501
	while (locked_pages > 0) {
3502 3503 3504 3505 3506 3507
		page = extent_buffer_page(eb, i);
		i++;
		unlock_page(page);
		locked_pages--;
	}
	return ret;
3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526
}

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);

C
Chris Mason 已提交
3527
	while (len > 0) {
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
		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++;
	}
}

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;
	}
C
Chris Mason 已提交
3565

3566
	if (start + min_len > eb->len) {
C
Chris Mason 已提交
3567 3568 3569
		printk(KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
		       "wanted %lu %lu\n", (unsigned long long)eb->start,
		       eb->len, start, min_len);
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
		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;
}

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;
}

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

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);

C
Chris Mason 已提交
3628
	while (len > 0) {
3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662
		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;
}

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);

C
Chris Mason 已提交
3663
	while (len > 0) {
3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693
		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++;
	}
}

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);

C
Chris Mason 已提交
3694
	while (len > 0) {
3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725
		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++;
	}
}

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);

C
Chris Mason 已提交
3726
	while (len > 0) {
3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791
		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++;
	}
}

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) {
C
Chris Mason 已提交
3792 3793
		printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
		       "len %lu dst len %lu\n", src_offset, len, dst->len);
3794 3795 3796
		BUG_ON(1);
	}
	if (dst_offset + len > dst->len) {
C
Chris Mason 已提交
3797 3798
		printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
		       "len %lu dst len %lu\n", dst_offset, len, dst->len);
3799 3800 3801
		BUG_ON(1);
	}

C
Chris Mason 已提交
3802
	while (len > 0) {
3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838
		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;
	}
}

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) {
C
Chris Mason 已提交
3839 3840
		printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
		       "len %lu len %lu\n", src_offset, len, dst->len);
3841 3842 3843
		BUG_ON(1);
	}
	if (dst_offset + len > dst->len) {
C
Chris Mason 已提交
3844 3845
		printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
		       "len %lu len %lu\n", dst_offset, len, dst->len);
3846 3847 3848 3849 3850 3851
		BUG_ON(1);
	}
	if (dst_offset < src_offset) {
		memcpy_extent_buffer(dst, dst_offset, src_offset, len);
		return;
	}
C
Chris Mason 已提交
3852
	while (len > 0) {
3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872
		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;
	}
}
3873

3874 3875 3876 3877 3878 3879 3880 3881
static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
{
	struct extent_buffer *eb =
			container_of(head, struct extent_buffer, rcu_head);

	btrfs_release_extent_buffer(eb);
}

3882 3883 3884 3885 3886 3887 3888
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;

	spin_lock(&tree->buffer_lock);
3889
	eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3890 3891 3892 3893
	if (!eb) {
		spin_unlock(&tree->buffer_lock);
		return ret;
	}
3894

3895
	if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3896 3897 3898
		ret = 0;
		goto out;
	}
3899 3900 3901 3902 3903 3904

	/*
	 * set @eb->refs to 0 if it is already 1, and then release the @eb.
	 * Or go back.
	 */
	if (atomic_cmpxchg(&eb->refs, 1, 0) != 1) {
3905 3906 3907
		ret = 0;
		goto out;
	}
3908

3909
	radix_tree_delete(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3910 3911
out:
	spin_unlock(&tree->buffer_lock);
3912 3913 3914 3915

	/* at this point we can safely release the extent buffer */
	if (atomic_read(&eb->refs) == 0)
		call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
3916 3917
	return ret;
}