[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 != btrfs_header_blocknr(&buf->node.header))
		BUG();
	if (root->node && btrfs_header_parentid(&buf->node.header) !=
	    btrfs_header_parentid(&root->node->node.header))
		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 != btrfs_header_blocknr(&buf->node.header))
		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, struct ctree_super_block *s)
{
	int ret = 0;

	ret = __commit_transaction(root);
	if (!ret && root != root->extent_root)
		ret = __commit_transaction(root->extent_root);
	BUG_ON(ret);
	if (root->commit_root != root->node) {
		struct tree_buffer *snap = root->commit_root;
		root->commit_root = root->node;
		root->node->count++;
		ret = btrfs_drop_snapshot(root, snap);
		BUG_ON(ret);
		// tree_block_release(root, snap);
	}
        write_ctree_super(root, s);
	btrfs_finish_extent_commit(root);
	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->cache_size = 0;
	root->fp = fp;
	root->node = NULL;
	root->extent_root = extent_root;
	root->commit_root = NULL;
	root->node = read_tree_block(root, info->tree_root);
	memset(&root->current_insert, 0, sizeof(root->current_insert));
	memset(&root->last_insert, 0, sizeof(root->last_insert));
	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(&root->pinned_radix, GFP_KERNEL);
	INIT_RADIX_TREE(&extent_root->pinned_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);
	root->commit_root = root->node;
	root->node->count++;
	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, struct ctree_super_block *s)
{
	commit_transaction(root, s);
	__commit_transaction(root->extent_root);
	write_ctree_super(root, s);
	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);
	tree_block_release(root, root->commit_root);
	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	{
7518a238	18	if (buf->blocknr != btrfs_header_blocknr(&buf->node.header))
9a8dd150	19	BUG();
7518a238 CM	20	if (root->node && btrfs_header_parentid(&buf->node.header) !=
7518a238 CM	21	btrfs_header_parentid(&root->node->node.header))
9a8dd150 CM	22	BUG();
9a8dd150 CM	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)
77ce6846	39	break;
ed2ff2cb CM	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;
eb60ceac CM	132
7518a238	133	if (buf->blocknr != btrfs_header_blocknr(&buf->node.header))
eb60ceac CM	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
a28ec197	157	int commit_transaction(struct ctree_root root, struct ctree_super_block s)
ed2ff2cb	158	{
a28ec197 CM	159	int ret = 0;
a28ec197 CM	160
ed2ff2cb CM	161	ret = __commit_transaction(root);
	162	if (!ret && root != root->extent_root)
	163	ret = __commit_transaction(root->extent_root);
	164	BUG_ON(ret);
a28ec197 CM	165	if (root->commit_root != root->node) {
	166	struct tree_buffer *snap = root->commit_root;
	167	root->commit_root = root->node;
	168	root->node->count++;
	169	ret = btrfs_drop_snapshot(root, snap);
	170	BUG_ON(ret);
83e15a28	171	// tree_block_release(root, snap);
a28ec197 CM	172	}
	173	write_ctree_super(root, s);
	174	btrfs_finish_extent_commit(root);
ed2ff2cb CM	175	return ret;
	176	}
	177
d97e63b6 CM	178	static int __setup_root(struct ctree_root root, struct ctree_root extent_root,
	179	struct ctree_root_info *info, int fp)
	180	{
ed2ff2cb CM	181	INIT_LIST_HEAD(&root->trans);
ed2ff2cb CM	182	INIT_LIST_HEAD(&root->cache);
a28ec197	183	root->cache_size = 0;
d97e63b6	184	root->fp = fp;
cfaa7295	185	root->node = NULL;
d97e63b6	186	root->extent_root = extent_root;
a28ec197 CM	187	root->commit_root = NULL;
	188	root->node = read_tree_block(root, info->tree_root);
	189	memset(&root->current_insert, 0, sizeof(root->current_insert));
0579da42	190	memset(&root->last_insert, 0, sizeof(root->last_insert));
d97e63b6 CM	191	return 0;
	192	}
	193
cfaa7295	194	struct ctree_root open_ctree(char filename, struct ctree_super_block *super)
eb60ceac CM	195	{
eb60ceac CM	196	struct ctree_root *root = malloc(sizeof(struct ctree_root));
d97e63b6	197	struct ctree_root *extent_root = malloc(sizeof(struct ctree_root));
eb60ceac	198	int fp;
eb60ceac CM	199	int ret;
eb60ceac CM	200
c673024a	201	fp = open(filename, O_CREAT \| O_RDWR, 0600);
eb60ceac CM	202	if (fp < 0) {
	203	free(root);
	204	return NULL;
	205	}
9a8dd150	206	INIT_RADIX_TREE(&root->cache_radix, GFP_KERNEL);
a28ec197 CM	207	INIT_RADIX_TREE(&root->pinned_radix, GFP_KERNEL);
a28ec197 CM	208	INIT_RADIX_TREE(&extent_root->pinned_radix, GFP_KERNEL);
9a8dd150	209	INIT_RADIX_TREE(&extent_root->cache_radix, GFP_KERNEL);
cfaa7295	210	ret = pread(fp, super, sizeof(struct ctree_super_block),
d97e63b6	211	CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
5c680ed6 CM	212	if (ret == 0 \|\| super->root_info.tree_root == 0) {
5c680ed6 CM	213	printf("making new FS!\n");
d97e63b6 CM	214	ret = mkfs(fp);
	215	if (ret)
	216	return NULL;
cfaa7295	217	ret = pread(fp, super, sizeof(struct ctree_super_block),
d97e63b6 CM	218	CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
	219	if (ret != sizeof(struct ctree_super_block))
	220	return NULL;
	221	}
	222	BUG_ON(ret < 0);
cfaa7295 CM	223	__setup_root(root, extent_root, &super->root_info, fp);
cfaa7295 CM	224	__setup_root(extent_root, extent_root, &super->extent_info, fp);
a28ec197 CM	225	root->commit_root = root->node;
a28ec197 CM	226	root->node->count++;
eb60ceac CM	227	return root;
	228	}
	229
cfaa7295	230	static int __update_root(struct ctree_root root, struct ctree_root_info info)
eb60ceac	231	{
cfaa7295	232	info->tree_root = root->node->blocknr;
eb60ceac CM	233	return 0;
	234	}
	235
cfaa7295	236	int write_ctree_super(struct ctree_root root, struct ctree_super_block s)
eb60ceac CM	237	{
eb60ceac CM	238	int ret;
cfaa7295 CM	239	__update_root(root, &s->root_info);
	240	__update_root(root->extent_root, &s->extent_info);
	241	ret = pwrite(root->fp, s, sizeof(*s), CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
	242	if (ret != sizeof(*s)) {
	243	fprintf(stderr, "failed to write new super block err %d\n", ret);
eb60ceac	244	return ret;
cfaa7295 CM	245	}
	246	return 0;
	247	}
	248
ed2ff2cb CM	249	static int drop_cache(struct ctree_root *root)
	250	{
	251	while(!list_empty(&root->cache)) {
	252	struct tree_buffer *b = list_entry(root->cache.next,
	253	struct tree_buffer, cache);
	254	list_del_init(&b->cache);
	255	tree_block_release(root, b);
	256	}
	257	return 0;
	258	}
a28ec197	259	int close_ctree(struct ctree_root root, struct ctree_super_block s)
cfaa7295	260	{
a28ec197 CM	261	commit_transaction(root, s);
	262	__commit_transaction(root->extent_root);
	263	write_ctree_super(root, s);
ed2ff2cb CM	264	drop_cache(root->extent_root);
	265	drop_cache(root);
	266	BUG_ON(!list_empty(&root->trans));
	267	BUG_ON(!list_empty(&root->extent_root->trans));
	268
cfaa7295 CM	269	close(root->fp);
	270	if (root->node)
	271	tree_block_release(root, root->node);
	272	if (root->extent_root->node)
	273	tree_block_release(root->extent_root, root->extent_root->node);
a28ec197	274	tree_block_release(root, root->commit_root);
cfaa7295 CM	275	free(root);
cfaa7295 CM	276	printf("on close %d blocks are allocated\n", allocated_blocks);
eb60ceac CM	277	return 0;
	278	}
	279
	280	void tree_block_release(struct ctree_root root, struct tree_buffer buf)
	281	{
	282	buf->count--;
cfaa7295 CM	283	if (buf->count < 0)
cfaa7295 CM	284	BUG();
eb60ceac	285	if (buf->count == 0) {
02217ed2 CM	286	BUG_ON(!list_empty(&buf->cache));
02217ed2 CM	287	BUG_ON(!list_empty(&buf->dirty));
eb60ceac CM	288	if (!radix_tree_lookup(&root->cache_radix, buf->blocknr))
	289	BUG();
	290	radix_tree_delete(&root->cache_radix, buf->blocknr);
	291	memset(buf, 0, sizeof(*buf));
	292	free(buf);
	293	BUG_ON(allocated_blocks == 0);
	294	allocated_blocks--;
ed2ff2cb CM	295	BUG_ON(root->cache_size == 0);
ed2ff2cb CM	296	root->cache_size--;
eb60ceac CM	297	}
	298	}
	299