Commit 80ea96b1 authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Add a lookup cache to the extent state tree 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 4529ba49

fs/btrfs/extent_io.c

+40 −17
Original line number Diff line number Diff line
@@ -90,6 +90,7 @@ void extent_io_tree_init(struct extent_io_tree *tree, 
	tree->mapping = mapping;

	INIT_LIST_HEAD(&tree->buffer_lru);

	tree->lru_size = 0;

	tree->last = NULL;

}

EXPORT_SYMBOL(extent_io_tree_init);
@@ -158,16 +159,23 @@ static struct rb_node *tree_insert(struct rb_root *root, u64 offset, 
	return NULL;

}



static struct rb_node *__tree_search(struct rb_root *root, u64 offset,

static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,

				     struct rb_node **prev_ret,

				     struct rb_node **next_ret)

{

	struct rb_root *root = &tree->state;

	struct rb_node * n = root->rb_node;

	struct rb_node *prev = NULL;

	struct rb_node *orig_prev = NULL;

	struct tree_entry *entry;

	struct tree_entry *prev_entry = NULL;



	if (tree->last) {

		struct extent_state *state;

		state = tree->last;

		if (state->start <= offset && offset <= state->end)

			return &tree->last->rb_node;

	}

	while(n) {

		entry = rb_entry(n, struct tree_entry, rb_node);

		prev = n;
@@ -177,9 +185,11 @@ static struct rb_node *__tree_search(struct rb_root *root, u64 offset, 
			n = n->rb_left;

		else if (offset > entry->end)

			n = n->rb_right;

		else

		else {

			tree->last = rb_entry(n, struct extent_state, rb_node);

			return n;

		}

	}



	if (prev_ret) {

		orig_prev = prev;
@@ -202,14 +212,20 @@ static struct rb_node *__tree_search(struct rb_root *root, u64 offset, 
	return NULL;

}



static inline struct rb_node *tree_search(struct rb_root *root, u64 offset)

static inline struct rb_node *tree_search(struct extent_io_tree *tree,

					  u64 offset)

{

	struct rb_node *prev = NULL;

	struct rb_node *ret;



	ret = __tree_search(root, offset, &prev, NULL);

	if (!ret)

	ret = __etree_search(tree, offset, &prev, NULL);

	if (!ret) {

		if (prev) {

			tree->last = rb_entry(prev, struct extent_state,

					      rb_node);

		}

		return prev;

	}

	return ret;

}
@@ -238,6 +254,8 @@ static int merge_state(struct extent_io_tree *tree, 
		    other->state == state->state) {

			state->start = other->start;

			other->tree = NULL;

			if (tree->last == other)

				tree->last = NULL;

			rb_erase(&other->rb_node, &tree->state);

			free_extent_state(other);

		}
@@ -249,6 +267,8 @@ static int merge_state(struct extent_io_tree *tree, 
		    other->state == state->state) {

			other->start = state->start;

			state->tree = NULL;

			if (tree->last == state)

				tree->last = NULL;

			rb_erase(&state->rb_node, &tree->state);

			free_extent_state(state);

		}
@@ -311,6 +331,7 @@ static int insert_state(struct extent_io_tree *tree, 
		return -EEXIST;

	}

	state->tree = tree;

	tree->last = state;

	merge_state(tree, state);

	return 0;

}
@@ -375,6 +396,8 @@ static int clear_state_bit(struct extent_io_tree *tree, 
		wake_up(&state->wq);

	if (delete || state->state == 0) {

		if (state->tree) {

			if (tree->last == state)

				tree->last = NULL;

			rb_erase(&state->rb_node, &tree->state);

			state->tree = NULL;

			free_extent_state(state);
@@ -422,7 +445,7 @@ again: 
	 * this search will find the extents that end after

	 * our range starts

	 */

	node = tree_search(&tree->state, start);

	node = tree_search(tree, start);

	if (!node)

		goto out;

	state = rb_entry(node, struct extent_state, rb_node);
@@ -533,7 +556,7 @@ again: 
		 * this search will find all the extents that end after

		 * our range starts

		 */

		node = tree_search(&tree->state, start);

		node = tree_search(tree, start);

		if (!node)

			break;
@@ -612,7 +635,7 @@ again: 
	 * this search will find all the extents that end after

	 * our range starts.

	 */

	node = tree_search(&tree->state, start);

	node = tree_search(tree, start);

	if (!node) {

		err = insert_state(tree, prealloc, start, end, bits);

		prealloc = NULL;
@@ -915,7 +938,7 @@ int find_first_extent_bit(struct extent_io_tree *tree, u64 start, 
	 * this search will find all the extents that end after

	 * our range starts.

	 */

	node = tree_search(&tree->state, start);

	node = tree_search(tree, start);

	if (!node || IS_ERR(node)) {

		goto out;

	}
@@ -953,7 +976,7 @@ u64 find_lock_delalloc_range(struct extent_io_tree *tree, 
	 * our range starts.

	 */

search_again:

	node = tree_search(&tree->state, cur_start);

	node = tree_search(tree, cur_start);

	if (!node || IS_ERR(node)) {

		*end = (u64)-1;

		goto out;
@@ -1041,7 +1064,7 @@ u64 count_range_bits(struct extent_io_tree *tree, 
	 * this search will find all the extents that end after

	 * our range starts.

	 */

	node = tree_search(&tree->state, cur_start);

	node = tree_search(tree, cur_start);

	if (!node || IS_ERR(node)) {

		goto out;

	}
@@ -1142,7 +1165,7 @@ int set_state_private(struct extent_io_tree *tree, u64 start, u64 private) 
	 * this search will find all the extents that end after

	 * our range starts.

	 */

	node = tree_search(&tree->state, start);

	node = tree_search(tree, start);

	if (!node || IS_ERR(node)) {

		ret = -ENOENT;

		goto out;
@@ -1169,7 +1192,7 @@ int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private) 
	 * this search will find all the extents that end after

	 * our range starts.

	 */

	node = tree_search(&tree->state, start);

	node = tree_search(tree, start);

	if (!node || IS_ERR(node)) {

		ret = -ENOENT;

		goto out;
@@ -1200,7 +1223,7 @@ int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, 
	unsigned long flags;



	spin_lock_irqsave(&tree->lock, flags);

	node = tree_search(&tree->state, start);

	node = tree_search(tree, start);

	while (node && start <= end) {

		state = rb_entry(node, struct extent_state, rb_node);
@@ -1348,7 +1371,7 @@ static int end_bio_extent_writepage(struct bio *bio, 
		spin_lock_irqsave(&tree->lock, flags);

		if (!state || state->end != end) {

			state = NULL;

			node = __tree_search(&tree->state, start, NULL, NULL);

			node = __etree_search(tree, start, NULL, NULL);

			if (node) {

				state = rb_entry(node, struct extent_state,

						 rb_node);
@@ -1468,7 +1491,7 @@ static int end_bio_extent_readpage(struct bio *bio, 
		spin_lock_irqsave(&tree->lock, flags);

		if (!state || state->end != end) {

			state = NULL;

			node = __tree_search(&tree->state, start, NULL, NULL);

			node = __etree_search(tree, start, NULL, NULL);

			if (node) {

				state = rb_entry(node, struct extent_state,

						 rb_node);
@@ -1631,7 +1654,7 @@ static int submit_one_bio(int rw, struct bio *bio) 
	end = start + bvec->bv_len - 1;



	spin_lock_irq(&tree->lock);

	node = __tree_search(&tree->state, start, NULL, NULL);

	node = __etree_search(tree, start, NULL, NULL);

	BUG_ON(!node);

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

	while(state->end < end) {

fs/btrfs/extent_io.h

+1 −0
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ struct extent_io_tree { 
	spinlock_t lru_lock;

	struct list_head buffer_lru;

	int lru_size;

	struct extent_state *last;

};



struct extent_state {

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