[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_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)
				break;
		}
	}
	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) {
		BUG_ON(!list_empty(&buf->cache));
		BUG_ON(!list_empty(&buf->dirty));
		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	14	int cache_max = 10000;
eb60ceac	15
9a8dd150	16	static int check_tree_block(struct ctree_root root, struct tree_buffer buf)
eb60ceac	17	{
9a8dd150 CM	18	if (buf->blocknr != buf->node.header.blocknr)
	19	BUG();
	20	if (root->node && buf->node.header.parentid != root->node->node.header.parentid)
	21	BUG();
	22	return 0;
eb60ceac CM	23	}
eb60ceac CM	24
ed2ff2cb CM	25	static int free_some_buffers(struct ctree_root *root)
	26	{
	27	struct list_head node, next;
	28	struct tree_buffer *b;
	29	if (root->cache_size < cache_max)
	30	return 0;
	31	list_for_each_safe(node, next, &root->cache) {
	32	b = list_entry(node, struct tree_buffer, cache);
	33	if (b->count == 1) {
	34	BUG_ON(!list_empty(&b->dirty));
	35	list_del_init(&b->cache);
	36	tree_block_release(root, b);
	37	if (root->cache_size < cache_max)
77ce6846	38	break;
ed2ff2cb CM	39	}
	40	}
	41	return 0;
	42	}
	43
eb60ceac CM	44	struct tree_buffer alloc_tree_block(struct ctree_root root, u64 blocknr)
	45	{
	46	struct tree_buffer *buf;
	47	int ret;
	48	buf = malloc(sizeof(struct tree_buffer));
	49	if (!buf)
	50	return buf;
	51	allocated_blocks++;
	52	buf->blocknr = blocknr;
ed2ff2cb CM	53	buf->count = 2;
	54	INIT_LIST_HEAD(&buf->dirty);
	55	free_some_buffers(root);
eb60ceac CM	56	radix_tree_preload(GFP_KERNEL);
	57	ret = radix_tree_insert(&root->cache_radix, blocknr, buf);
	58	radix_tree_preload_end();
ed2ff2cb CM	59	list_add_tail(&buf->cache, &root->cache);
ed2ff2cb CM	60	root->cache_size++;
eb60ceac CM	61	if (ret) {
	62	free(buf);
	63	return NULL;
	64	}
	65	return buf;
	66	}
	67
9a8dd150	68	struct tree_buffer find_tree_block(struct ctree_root root, u64 blocknr)
eb60ceac	69	{
9a8dd150 CM	70	struct tree_buffer *buf;
	71	buf = radix_tree_lookup(&root->cache_radix, blocknr);
	72	if (buf) {
	73	buf->count++;
	74	} else {
	75	buf = alloc_tree_block(root, blocknr);
	76	if (!buf) {
	77	BUG();
	78	return NULL;
	79	}
eb60ceac	80	}
eb60ceac CM	81	return buf;
	82	}
	83
	84	struct tree_buffer read_tree_block(struct ctree_root root, u64 blocknr)
	85	{
d97e63b6	86	loff_t offset = blocknr * CTREE_BLOCKSIZE;
eb60ceac CM	87	struct tree_buffer *buf;
	88	int ret;
	89
	90	buf = radix_tree_lookup(&root->cache_radix, blocknr);
	91	if (buf) {
	92	buf->count++;
9a8dd150 CM	93	} else {
	94	buf = alloc_tree_block(root, blocknr);
	95	if (!buf)
	96	return NULL;
	97	ret = pread(root->fp, &buf->node, CTREE_BLOCKSIZE, offset);
	98	if (ret != CTREE_BLOCKSIZE) {
	99	free(buf);
	100	return NULL;
	101	}
eb60ceac	102	}
9a8dd150	103	if (check_tree_block(root, buf))
cfaa7295	104	BUG();
eb60ceac CM	105	return buf;
	106	}
	107
ed2ff2cb CM	108	int dirty_tree_block(struct ctree_root root, struct tree_buffer buf)
	109	{
	110	if (!list_empty(&buf->dirty))
	111	return 0;
	112	list_add_tail(&buf->dirty, &root->trans);
	113	buf->count++;
	114	return 0;
	115	}
	116
	117	int clean_tree_block(struct ctree_root root, struct tree_buffer buf)
	118	{
	119	if (!list_empty(&buf->dirty)) {
	120	list_del_init(&buf->dirty);
	121	tree_block_release(root, buf);
	122	}
	123	return 0;
	124	}
	125
eb60ceac CM	126	int write_tree_block(struct ctree_root root, struct tree_buffer buf)
	127	{
	128	u64 blocknr = buf->blocknr;
d97e63b6	129	loff_t offset = blocknr * CTREE_BLOCKSIZE;
eb60ceac CM	130	int ret;
	131
	132	if (buf->blocknr != buf->node.header.blocknr)
	133	BUG();
	134	ret = pwrite(root->fp, &buf->node, CTREE_BLOCKSIZE, offset);
	135	if (ret != CTREE_BLOCKSIZE)
	136	return ret;
eb60ceac CM	137	return 0;
	138	}
	139
ed2ff2cb CM	140	static int __commit_transaction(struct ctree_root *root)
	141	{
	142	struct tree_buffer *b;
	143	int ret = 0;
	144	int wret;
	145	while(!list_empty(&root->trans)) {
	146	b = list_entry(root->trans.next, struct tree_buffer, dirty);
	147	list_del_init(&b->dirty);
	148	wret = write_tree_block(root, b);
	149	if (wret)
	150	ret = wret;
	151	tree_block_release(root, b);
	152	}
	153	return ret;
	154	}
	155
	156	int commit_transaction(struct ctree_root *root)
	157	{
	158	int ret;
	159	ret = __commit_transaction(root);
	160	if (!ret && root != root->extent_root)
	161	ret = __commit_transaction(root->extent_root);
	162	BUG_ON(ret);
	163	return ret;
	164	}
	165
d97e63b6 CM	166	static int __setup_root(struct ctree_root root, struct ctree_root extent_root,
	167	struct ctree_root_info *info, int fp)
	168	{
ed2ff2cb CM	169	INIT_LIST_HEAD(&root->trans);
ed2ff2cb CM	170	INIT_LIST_HEAD(&root->cache);
d97e63b6	171	root->fp = fp;
cfaa7295	172	root->node = NULL;
d97e63b6 CM	173	root->node = read_tree_block(root, info->tree_root);
d97e63b6 CM	174	root->extent_root = extent_root;
d97e63b6 CM	175	return 0;
	176	}
	177
cfaa7295	178	struct ctree_root open_ctree(char filename, struct ctree_super_block *super)
eb60ceac CM	179	{
eb60ceac CM	180	struct ctree_root *root = malloc(sizeof(struct ctree_root));
d97e63b6	181	struct ctree_root *extent_root = malloc(sizeof(struct ctree_root));
eb60ceac	182	int fp;
eb60ceac CM	183	int ret;
eb60ceac CM	184
c673024a	185	fp = open(filename, O_CREAT \| O_RDWR, 0600);
eb60ceac CM	186	if (fp < 0) {
	187	free(root);
	188	return NULL;
	189	}
9a8dd150 CM	190	INIT_RADIX_TREE(&root->cache_radix, GFP_KERNEL);
9a8dd150 CM	191	INIT_RADIX_TREE(&extent_root->cache_radix, GFP_KERNEL);
cfaa7295	192	ret = pread(fp, super, sizeof(struct ctree_super_block),
d97e63b6	193	CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
5c680ed6 CM	194	if (ret == 0 \|\| super->root_info.tree_root == 0) {
5c680ed6 CM	195	printf("making new FS!\n");
d97e63b6 CM	196	ret = mkfs(fp);
	197	if (ret)
	198	return NULL;
cfaa7295	199	ret = pread(fp, super, sizeof(struct ctree_super_block),
d97e63b6 CM	200	CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
	201	if (ret != sizeof(struct ctree_super_block))
	202	return NULL;
	203	}
	204	BUG_ON(ret < 0);
cfaa7295 CM	205	__setup_root(root, extent_root, &super->root_info, fp);
cfaa7295 CM	206	__setup_root(extent_root, extent_root, &super->extent_info, fp);
eb60ceac CM	207	return root;
	208	}
	209
cfaa7295	210	static int __update_root(struct ctree_root root, struct ctree_root_info info)
eb60ceac	211	{
cfaa7295	212	info->tree_root = root->node->blocknr;
eb60ceac CM	213	return 0;
	214	}
	215
cfaa7295	216	int write_ctree_super(struct ctree_root root, struct ctree_super_block s)
eb60ceac CM	217	{
eb60ceac CM	218	int ret;
cfaa7295 CM	219	__update_root(root, &s->root_info);
	220	__update_root(root->extent_root, &s->extent_info);
	221	ret = pwrite(root->fp, s, sizeof(*s), CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
	222	if (ret != sizeof(*s)) {
	223	fprintf(stderr, "failed to write new super block err %d\n", ret);
eb60ceac	224	return ret;
cfaa7295 CM	225	}
	226	return 0;
	227	}
	228
ed2ff2cb CM	229	static int drop_cache(struct ctree_root *root)
	230	{
	231	while(!list_empty(&root->cache)) {
	232	struct tree_buffer *b = list_entry(root->cache.next,
	233	struct tree_buffer, cache);
	234	list_del_init(&b->cache);
	235	tree_block_release(root, b);
	236	}
	237	return 0;
	238	}
cfaa7295 CM	239	int close_ctree(struct ctree_root *root)
cfaa7295 CM	240	{
f0930a37	241	commit_transaction(root);
ed2ff2cb CM	242	drop_cache(root->extent_root);
	243	drop_cache(root);
	244	BUG_ON(!list_empty(&root->trans));
	245	BUG_ON(!list_empty(&root->extent_root->trans));
	246
cfaa7295 CM	247	close(root->fp);
	248	if (root->node)
	249	tree_block_release(root, root->node);
	250	if (root->extent_root->node)
	251	tree_block_release(root->extent_root, root->extent_root->node);
	252	free(root);
	253	printf("on close %d blocks are allocated\n", allocated_blocks);
eb60ceac CM	254	return 0;
	255	}
	256
	257	void tree_block_release(struct ctree_root root, struct tree_buffer buf)
	258	{
	259	buf->count--;
cfaa7295 CM	260	if (buf->count < 0)
cfaa7295 CM	261	BUG();
eb60ceac	262	if (buf->count == 0) {
02217ed2 CM	263	BUG_ON(!list_empty(&buf->cache));
02217ed2 CM	264	BUG_ON(!list_empty(&buf->dirty));
eb60ceac CM	265	if (!radix_tree_lookup(&root->cache_radix, buf->blocknr))
	266	BUG();
	267	radix_tree_delete(&root->cache_radix, buf->blocknr);
	268	memset(buf, 0, sizeof(*buf));
	269	free(buf);
	270	BUG_ON(allocated_blocks == 0);
	271	allocated_blocks--;
ed2ff2cb CM	272	BUG_ON(root->cache_size == 0);
ed2ff2cb CM	273	root->cache_size--;
eb60ceac CM	274	}
	275	}
	276