[linux-2.6-block.git] / fs / btrfs / disk-io.c

#define _XOPEN_SOURCE 500
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "kerncompat.h"
#include "radix-tree.h"
#include "ctree.h"
#include "disk-io.h"

static int allocated_blocks = 0;
int cache_size = 0;
int cache_max = 10000;

static int check_tree_block(struct ctree_root *root, struct tree_buffer *buf)
{
	if (buf->blocknr != buf->node.header.blocknr)
		BUG();
	if (root->node && buf->node.header.parentid != root->node->node.header.parentid)
		BUG();
	return 0;
}

static int free_some_buffers(struct ctree_root *root)
{
	struct list_head *node, *next;
	struct tree_buffer *b;
	if (root->cache_size < cache_max)
		return 0;
	list_for_each_safe(node, next, &root->cache) {
		b = list_entry(node, struct tree_buffer, cache);
		if (b->count == 1) {
			BUG_ON(!list_empty(&b->dirty));
			list_del_init(&b->cache);
			tree_block_release(root, b);
			if (root->cache_size < cache_max)
				return 0;
		}
	}
	return 0;
}

struct tree_buffer *alloc_tree_block(struct ctree_root *root, u64 blocknr)
{
	struct tree_buffer *buf;
	int ret;
	buf = malloc(sizeof(struct tree_buffer));
	if (!buf)
		return buf;
	allocated_blocks++;
	buf->blocknr = blocknr;
	buf->count = 2;
	INIT_LIST_HEAD(&buf->dirty);
	free_some_buffers(root);
	radix_tree_preload(GFP_KERNEL);
	ret = radix_tree_insert(&root->cache_radix, blocknr, buf);
	radix_tree_preload_end();
	list_add_tail(&buf->cache, &root->cache);
	root->cache_size++;
	if (ret) {
		free(buf);
		return NULL;
	}
	return buf;
}

struct tree_buffer *find_tree_block(struct ctree_root *root, u64 blocknr)
{
	struct tree_buffer *buf;
	buf = radix_tree_lookup(&root->cache_radix, blocknr);
	if (buf) {
		buf->count++;
	} else {
		buf = alloc_tree_block(root, blocknr);
		if (!buf) {
			BUG();
			return NULL;
		}
	}
	return buf;
}

struct tree_buffer *read_tree_block(struct ctree_root *root, u64 blocknr)
{
	loff_t offset = blocknr * CTREE_BLOCKSIZE;
	struct tree_buffer *buf;
	int ret;

	buf = radix_tree_lookup(&root->cache_radix, blocknr);
	if (buf) {
		buf->count++;
	} else {
		buf = alloc_tree_block(root, blocknr);
		if (!buf)
			return NULL;
		ret = pread(root->fp, &buf->node, CTREE_BLOCKSIZE, offset);
		if (ret != CTREE_BLOCKSIZE) {
			free(buf);
			return NULL;
		}
	}
	if (check_tree_block(root, buf))
		BUG();
	return buf;
}

int dirty_tree_block(struct ctree_root *root, struct tree_buffer *buf)
{
	if (!list_empty(&buf->dirty))
		return 0;
	list_add_tail(&buf->dirty, &root->trans);
	buf->count++;
	return 0;
}

int clean_tree_block(struct ctree_root *root, struct tree_buffer *buf)
{
	if (!list_empty(&buf->dirty)) {
		list_del_init(&buf->dirty);
		tree_block_release(root, buf);
	}
	return 0;
}

int write_tree_block(struct ctree_root *root, struct tree_buffer *buf)
{
	u64 blocknr = buf->blocknr;
	loff_t offset = blocknr * CTREE_BLOCKSIZE;
	int ret;

	if (buf->blocknr != buf->node.header.blocknr)
		BUG();
	ret = pwrite(root->fp, &buf->node, CTREE_BLOCKSIZE, offset);
	if (ret != CTREE_BLOCKSIZE)
		return ret;
	return 0;
}

static int __commit_transaction(struct ctree_root *root)
{
	struct tree_buffer *b;
	int ret = 0;
	int wret;
	while(!list_empty(&root->trans)) {
		b = list_entry(root->trans.next, struct tree_buffer, dirty);
		list_del_init(&b->dirty);
		wret = write_tree_block(root, b);
		if (wret)
			ret = wret;
		tree_block_release(root, b);
	}
	return ret;
}

int commit_transaction(struct ctree_root *root)
{
	int ret;
	ret = __commit_transaction(root);
	if (!ret && root != root->extent_root)
		ret = __commit_transaction(root->extent_root);
	BUG_ON(ret);
	return ret;
}

static int __setup_root(struct ctree_root *root, struct ctree_root *extent_root,
			struct ctree_root_info *info, int fp)
{
	INIT_LIST_HEAD(&root->trans);
	INIT_LIST_HEAD(&root->cache);
	root->fp = fp;
	root->node = NULL;
	root->node = read_tree_block(root, info->tree_root);
	root->extent_root = extent_root;
	return 0;
}

struct ctree_root *open_ctree(char *filename, struct ctree_super_block *super)
{
	struct ctree_root *root = malloc(sizeof(struct ctree_root));
	struct ctree_root *extent_root = malloc(sizeof(struct ctree_root));
	int fp;
	int ret;

	fp = open(filename, O_CREAT | O_RDWR, 0600);
	if (fp < 0) {
		free(root);
		return NULL;
	}
	INIT_RADIX_TREE(&root->cache_radix, GFP_KERNEL);
	INIT_RADIX_TREE(&extent_root->cache_radix, GFP_KERNEL);
	ret = pread(fp, super, sizeof(struct ctree_super_block),
		     CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
	if (ret == 0 || super->root_info.tree_root == 0) {
		printf("making new FS!\n");
		ret = mkfs(fp);
		if (ret)
			return NULL;
		ret = pread(fp, super, sizeof(struct ctree_super_block),
			     CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
		if (ret != sizeof(struct ctree_super_block))
			return NULL;
	}
	BUG_ON(ret < 0);
	__setup_root(root, extent_root, &super->root_info, fp);
	__setup_root(extent_root, extent_root, &super->extent_info, fp);
	return root;
}

static int __update_root(struct ctree_root *root, struct ctree_root_info *info)
{
	info->tree_root = root->node->blocknr;
	return 0;
}

int write_ctree_super(struct ctree_root *root, struct ctree_super_block *s)
{
	int ret;
	__update_root(root, &s->root_info);
	__update_root(root->extent_root, &s->extent_info);
	ret = pwrite(root->fp, s, sizeof(*s), CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
	if (ret != sizeof(*s)) {
		fprintf(stderr, "failed to write new super block err %d\n", ret);
		return ret;
	}
	return 0;
}

static int drop_cache(struct ctree_root *root)
{
	while(!list_empty(&root->cache)) {
		struct tree_buffer *b = list_entry(root->cache.next,
						   struct tree_buffer, cache);
		list_del_init(&b->cache);
		tree_block_release(root, b);
	}
	return 0;
}
int close_ctree(struct ctree_root *root)
{
	commit_transaction(root);
	drop_cache(root->extent_root);
	drop_cache(root);
	BUG_ON(!list_empty(&root->trans));
	BUG_ON(!list_empty(&root->extent_root->trans));

	close(root->fp);
	if (root->node)
		tree_block_release(root, root->node);
	if (root->extent_root->node)
		tree_block_release(root->extent_root, root->extent_root->node);
	free(root);
	printf("on close %d blocks are allocated\n", allocated_blocks);
	return 0;
}

void tree_block_release(struct ctree_root *root, struct tree_buffer *buf)
{
	buf->count--;
	if (buf->count < 0)
		BUG();
	if (buf->count == 0) {
		if (!radix_tree_lookup(&root->cache_radix, buf->blocknr))
			BUG();
		radix_tree_delete(&root->cache_radix, buf->blocknr);
		memset(buf, 0, sizeof(*buf));
		free(buf);
		BUG_ON(allocated_blocks == 0);
		allocated_blocks--;
		BUG_ON(root->cache_size == 0);
		root->cache_size--;
	}
}
Commit	Line	Data
eb60ceac CM	1	#define _XOPEN_SOURCE 500
	2	#include <stdio.h>
	3	#include <stdlib.h>
	4	#include <sys/types.h>
	5	#include <sys/stat.h>
	6	#include <fcntl.h>
	7	#include <unistd.h>
	8	#include "kerncompat.h"
	9	#include "radix-tree.h"
	10	#include "ctree.h"
	11	#include "disk-io.h"
	12
	13	static int allocated_blocks = 0;
ed2ff2cb CM	14	int cache_size = 0;
ed2ff2cb CM	15	int cache_max = 10000;
eb60ceac	16
9a8dd150	17	static int check_tree_block(struct ctree_root root, struct tree_buffer buf)
eb60ceac	18	{
9a8dd150 CM	19	if (buf->blocknr != buf->node.header.blocknr)
	20	BUG();
	21	if (root->node && buf->node.header.parentid != root->node->node.header.parentid)
	22	BUG();
	23	return 0;
eb60ceac CM	24	}
eb60ceac CM	25
ed2ff2cb CM	26	static int free_some_buffers(struct ctree_root *root)
	27	{
	28	struct list_head node, next;
	29	struct tree_buffer *b;
	30	if (root->cache_size < cache_max)
	31	return 0;
	32	list_for_each_safe(node, next, &root->cache) {
	33	b = list_entry(node, struct tree_buffer, cache);
	34	if (b->count == 1) {
	35	BUG_ON(!list_empty(&b->dirty));
	36	list_del_init(&b->cache);
	37	tree_block_release(root, b);
	38	if (root->cache_size < cache_max)
	39	return 0;
	40	}
	41	}
	42	return 0;
	43	}
	44
eb60ceac CM	45	struct tree_buffer alloc_tree_block(struct ctree_root root, u64 blocknr)
	46	{
	47	struct tree_buffer *buf;
	48	int ret;
	49	buf = malloc(sizeof(struct tree_buffer));
	50	if (!buf)
	51	return buf;
	52	allocated_blocks++;
	53	buf->blocknr = blocknr;
ed2ff2cb CM	54	buf->count = 2;
	55	INIT_LIST_HEAD(&buf->dirty);
	56	free_some_buffers(root);
eb60ceac CM	57	radix_tree_preload(GFP_KERNEL);
	58	ret = radix_tree_insert(&root->cache_radix, blocknr, buf);
	59	radix_tree_preload_end();
ed2ff2cb CM	60	list_add_tail(&buf->cache, &root->cache);
ed2ff2cb CM	61	root->cache_size++;
eb60ceac CM	62	if (ret) {
	63	free(buf);
	64	return NULL;
	65	}
	66	return buf;
	67	}
	68
9a8dd150	69	struct tree_buffer find_tree_block(struct ctree_root root, u64 blocknr)
eb60ceac	70	{
9a8dd150 CM	71	struct tree_buffer *buf;
	72	buf = radix_tree_lookup(&root->cache_radix, blocknr);
	73	if (buf) {
	74	buf->count++;
	75	} else {
	76	buf = alloc_tree_block(root, blocknr);
	77	if (!buf) {
	78	BUG();
	79	return NULL;
	80	}
eb60ceac	81	}
eb60ceac CM	82	return buf;
	83	}
	84
	85	struct tree_buffer read_tree_block(struct ctree_root root, u64 blocknr)
	86	{
d97e63b6	87	loff_t offset = blocknr * CTREE_BLOCKSIZE;
eb60ceac CM	88	struct tree_buffer *buf;
	89	int ret;
	90
	91	buf = radix_tree_lookup(&root->cache_radix, blocknr);
	92	if (buf) {
	93	buf->count++;
9a8dd150 CM	94	} else {
	95	buf = alloc_tree_block(root, blocknr);
	96	if (!buf)
	97	return NULL;
	98	ret = pread(root->fp, &buf->node, CTREE_BLOCKSIZE, offset);
	99	if (ret != CTREE_BLOCKSIZE) {
	100	free(buf);
	101	return NULL;
	102	}
eb60ceac	103	}
9a8dd150	104	if (check_tree_block(root, buf))
cfaa7295	105	BUG();
eb60ceac CM	106	return buf;
	107	}
	108
ed2ff2cb CM	109	int dirty_tree_block(struct ctree_root root, struct tree_buffer buf)
	110	{
	111	if (!list_empty(&buf->dirty))
	112	return 0;
	113	list_add_tail(&buf->dirty, &root->trans);
	114	buf->count++;
	115	return 0;
	116	}
	117
	118	int clean_tree_block(struct ctree_root root, struct tree_buffer buf)
	119	{
	120	if (!list_empty(&buf->dirty)) {
	121	list_del_init(&buf->dirty);
	122	tree_block_release(root, buf);
	123	}
	124	return 0;
	125	}
	126
eb60ceac CM	127	int write_tree_block(struct ctree_root root, struct tree_buffer buf)
	128	{
	129	u64 blocknr = buf->blocknr;
d97e63b6	130	loff_t offset = blocknr * CTREE_BLOCKSIZE;
eb60ceac CM	131	int ret;
	132
	133	if (buf->blocknr != buf->node.header.blocknr)
	134	BUG();
	135	ret = pwrite(root->fp, &buf->node, CTREE_BLOCKSIZE, offset);
	136	if (ret != CTREE_BLOCKSIZE)
	137	return ret;
eb60ceac CM	138	return 0;
	139	}
	140
ed2ff2cb CM	141	static int __commit_transaction(struct ctree_root *root)
	142	{
	143	struct tree_buffer *b;
	144	int ret = 0;
	145	int wret;
	146	while(!list_empty(&root->trans)) {
	147	b = list_entry(root->trans.next, struct tree_buffer, dirty);
	148	list_del_init(&b->dirty);
	149	wret = write_tree_block(root, b);
	150	if (wret)
	151	ret = wret;
	152	tree_block_release(root, b);
	153	}
	154	return ret;
	155	}
	156
	157	int commit_transaction(struct ctree_root *root)
	158	{
	159	int ret;
	160	ret = __commit_transaction(root);
	161	if (!ret && root != root->extent_root)
	162	ret = __commit_transaction(root->extent_root);
	163	BUG_ON(ret);
	164	return ret;
	165	}
	166
d97e63b6 CM	167	static int __setup_root(struct ctree_root root, struct ctree_root extent_root,
	168	struct ctree_root_info *info, int fp)
	169	{
ed2ff2cb CM	170	INIT_LIST_HEAD(&root->trans);
ed2ff2cb CM	171	INIT_LIST_HEAD(&root->cache);
d97e63b6	172	root->fp = fp;
cfaa7295	173	root->node = NULL;
d97e63b6 CM	174	root->node = read_tree_block(root, info->tree_root);
d97e63b6 CM	175	root->extent_root = extent_root;
d97e63b6 CM	176	return 0;
	177	}
	178
cfaa7295	179	struct ctree_root open_ctree(char filename, struct ctree_super_block *super)
eb60ceac CM	180	{
eb60ceac CM	181	struct ctree_root *root = malloc(sizeof(struct ctree_root));
d97e63b6	182	struct ctree_root *extent_root = malloc(sizeof(struct ctree_root));
eb60ceac	183	int fp;
eb60ceac CM	184	int ret;
eb60ceac CM	185
c673024a	186	fp = open(filename, O_CREAT \| O_RDWR, 0600);
eb60ceac CM	187	if (fp < 0) {
	188	free(root);
	189	return NULL;
	190	}
9a8dd150 CM	191	INIT_RADIX_TREE(&root->cache_radix, GFP_KERNEL);
9a8dd150 CM	192	INIT_RADIX_TREE(&extent_root->cache_radix, GFP_KERNEL);
cfaa7295	193	ret = pread(fp, super, sizeof(struct ctree_super_block),
d97e63b6	194	CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
5c680ed6 CM	195	if (ret == 0 \|\| super->root_info.tree_root == 0) {
5c680ed6 CM	196	printf("making new FS!\n");
d97e63b6 CM	197	ret = mkfs(fp);
	198	if (ret)
	199	return NULL;
cfaa7295	200	ret = pread(fp, super, sizeof(struct ctree_super_block),
d97e63b6 CM	201	CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
	202	if (ret != sizeof(struct ctree_super_block))
	203	return NULL;
	204	}
	205	BUG_ON(ret < 0);
cfaa7295 CM	206	__setup_root(root, extent_root, &super->root_info, fp);
cfaa7295 CM	207	__setup_root(extent_root, extent_root, &super->extent_info, fp);
eb60ceac CM	208	return root;
	209	}
	210
cfaa7295	211	static int __update_root(struct ctree_root root, struct ctree_root_info info)
eb60ceac	212	{
cfaa7295	213	info->tree_root = root->node->blocknr;
eb60ceac CM	214	return 0;
	215	}
	216
cfaa7295	217	int write_ctree_super(struct ctree_root root, struct ctree_super_block s)
eb60ceac CM	218	{
eb60ceac CM	219	int ret;
cfaa7295 CM	220	__update_root(root, &s->root_info);
	221	__update_root(root->extent_root, &s->extent_info);
	222	ret = pwrite(root->fp, s, sizeof(*s), CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
	223	if (ret != sizeof(*s)) {
	224	fprintf(stderr, "failed to write new super block err %d\n", ret);
eb60ceac	225	return ret;
cfaa7295 CM	226	}
	227	return 0;
	228	}
	229
ed2ff2cb CM	230	static int drop_cache(struct ctree_root *root)
	231	{
	232	while(!list_empty(&root->cache)) {
	233	struct tree_buffer *b = list_entry(root->cache.next,
	234	struct tree_buffer, cache);
	235	list_del_init(&b->cache);
	236	tree_block_release(root, b);
	237	}
	238	return 0;
	239	}
cfaa7295 CM	240	int close_ctree(struct ctree_root *root)
cfaa7295 CM	241	{
f0930a37	242	commit_transaction(root);
ed2ff2cb CM	243	drop_cache(root->extent_root);
	244	drop_cache(root);
	245	BUG_ON(!list_empty(&root->trans));
	246	BUG_ON(!list_empty(&root->extent_root->trans));
	247
cfaa7295 CM	248	close(root->fp);
	249	if (root->node)
	250	tree_block_release(root, root->node);
	251	if (root->extent_root->node)
	252	tree_block_release(root->extent_root, root->extent_root->node);
	253	free(root);
	254	printf("on close %d blocks are allocated\n", allocated_blocks);
eb60ceac CM	255	return 0;
	256	}
	257
	258	void tree_block_release(struct ctree_root root, struct tree_buffer buf)
	259	{
	260	buf->count--;
cfaa7295 CM	261	if (buf->count < 0)
cfaa7295 CM	262	BUG();
eb60ceac CM	263	if (buf->count == 0) {
	264	if (!radix_tree_lookup(&root->cache_radix, buf->blocknr))
	265	BUG();
	266	radix_tree_delete(&root->cache_radix, buf->blocknr);
	267	memset(buf, 0, sizeof(*buf));
	268	free(buf);
	269	BUG_ON(allocated_blocks == 0);
	270	allocated_blocks--;
ed2ff2cb CM	271	BUG_ON(root->cache_size == 0);
ed2ff2cb CM	272	root->cache_size--;
eb60ceac CM	273	}
	274	}
	275