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Commit 8ef97622 authored by Chris Mason's avatar Chris Mason Committed by David Woodhouse
Browse files

Btrfs: add a radix back bit tree 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent f7922033

fs/btrfs/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -3,7 +3,8 @@ ifneq ($(KERNELRELEASE),) 


obj-m  := btrfs.o

btrfs-y := super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \

	   hash.o file-item.o inode-item.o inode-map.o disk-io.o transaction.o

	   hash.o file-item.o inode-item.o inode-map.o disk-io.o \

	   transaction.o bit-radix.o



#btrfs-y := ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \

#	  root-tree.o dir-item.o hash.o file-item.o inode-item.o \

fs/btrfs/bit-radix.c

0 → 100644
+107 −0
Original line number Diff line number Diff line 
#include <linux/module.h>

#include "bit-radix.h"



#define BIT_ARRAY_BYTES 256

#define BIT_RADIX_BITS_PER_ARRAY ((BIT_ARRAY_BYTES - sizeof(unsigned long)) * 8)



int set_radix_bit(struct radix_tree_root *radix, unsigned long bit)

{

	unsigned long *bits;

	unsigned long slot;

	int bit_slot;

	int ret;



	slot = bit / BIT_RADIX_BITS_PER_ARRAY;

	bit_slot = bit % BIT_RADIX_BITS_PER_ARRAY;



	bits = radix_tree_lookup(radix, slot);

	if (!bits) {

		bits = kmalloc(BIT_ARRAY_BYTES, GFP_NOIO);

		if (!bits)

			return -ENOMEM;

		memset(bits + 1, 0, BIT_ARRAY_BYTES - sizeof(unsigned long));

		bits[0] = slot;

		ret = radix_tree_insert(radix, slot, bits);

		if (ret)

			return ret;

	}

	set_bit(bit_slot, bits + 1);

	return 0;

}



int test_radix_bit(struct radix_tree_root *radix, unsigned long bit)

{

	unsigned long *bits;

	unsigned long slot;

	int bit_slot;



	slot = bit / BIT_RADIX_BITS_PER_ARRAY;

	bit_slot = bit % BIT_RADIX_BITS_PER_ARRAY;



	bits = radix_tree_lookup(radix, slot);

	if (!bits)

		return 0;

	return test_bit(bit_slot, bits + 1);

}



int clear_radix_bit(struct radix_tree_root *radix, unsigned long bit)

{

	unsigned long *bits;

	unsigned long slot;

	int bit_slot;

	int i;

	int empty = 1;



	slot = bit / BIT_RADIX_BITS_PER_ARRAY;

	bit_slot = bit % BIT_RADIX_BITS_PER_ARRAY;



	bits = radix_tree_lookup(radix, slot);

	if (!bits)

		return 0;

	clear_bit(bit_slot, bits + 1);



	for (i = 1; i < BIT_ARRAY_BYTES / sizeof(unsigned long); i++) {

		if (bits[i]) {

			empty = 0;

			break;

		}

	}



	if (empty) {

		bits = radix_tree_delete(radix, slot);

		BUG_ON(!bits);

	}

	return 0;

}



int find_first_radix_bit(struct radix_tree_root *radix, unsigned long *retbits,

			 int nr)

{

	unsigned long *bits;

	unsigned long *gang[4];

	int found;

	int ret;

	int i;

	int total_found = 0;



	ret = radix_tree_gang_lookup(radix, (void *)&gang, 0, ARRAY_SIZE(gang));

	for (i = 0; i < ret && nr > 0; i++) {

		found = 0;

		bits = gang[i];

		while(nr > 0) {

			found = find_next_bit(bits + 1,

					      BIT_RADIX_BITS_PER_ARRAY,

					      found);

			if (found < BIT_RADIX_BITS_PER_ARRAY) {

				*retbits = bits[0] *

					BIT_RADIX_BITS_PER_ARRAY + found;

				retbits++;

				nr--;

				total_found++;

				found++;

			} else

				break;

		}

	}

	return total_found;

}

fs/btrfs/bit-radix.h

0 → 100644
+15 −0
Original line number Diff line number Diff line 
#ifndef __BIT_RADIX__

#define __BIT_RADIX__

#include <linux/radix-tree.h>



int set_radix_bit(struct radix_tree_root *radix, unsigned long bit);

int test_radix_bit(struct radix_tree_root *radix, unsigned long bit);

int clear_radix_bit(struct radix_tree_root *radix, unsigned long bit);

int find_first_radix_bit(struct radix_tree_root *radix, unsigned long *retbits,

			 int nr);



static inline void init_bit_radix(struct radix_tree_root *radix)

{

	INIT_RADIX_TREE(radix, GFP_NOFS);

}

#endif

fs/btrfs/ctree.h

+2 −1
Original line number Diff line number Diff line 
#ifndef __BTRFS__

#define __BTRFS__



#include <linux/radix-tree.h>

#include <linux/fs.h>

#include "bit-radix.h"



struct btrfs_trans_handle;

struct btrfs_transaction;
@@ -222,6 +222,7 @@ struct btrfs_fs_info { 
	struct btrfs_root *inode_root;

	struct btrfs_key current_insert;

	struct btrfs_key last_insert;

	struct radix_tree_root pending_del_radix;

	struct radix_tree_root pinned_radix;

	u64 last_inode_alloc;

	u64 last_inode_alloc_dirid;

fs/btrfs/disk-io.c

+2 −1
Original line number Diff line number Diff line
@@ -104,7 +104,8 @@ struct btrfs_root *open_ctree(struct super_block *sb, 
	/* FIXME: don't be stupid */

	if (!btrfs_super_root(disk_super))

		return NULL;

	INIT_RADIX_TREE(&fs_info->pinned_radix, GFP_KERNEL);

	init_bit_radix(&fs_info->pinned_radix);

	init_bit_radix(&fs_info->pending_del_radix);

	fs_info->running_transaction = NULL;

	fs_info->fs_root = root;

	fs_info->tree_root = tree_root;