[deliverable/linux.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, 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));
	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	{
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
a28ec197	156	int commit_transaction(struct ctree_root root, struct ctree_super_block s)
ed2ff2cb	157	{
a28ec197 CM	158	int ret = 0;
a28ec197 CM	159
ed2ff2cb CM	160	ret = __commit_transaction(root);
	161	if (!ret && root != root->extent_root)
	162	ret = __commit_transaction(root->extent_root);
	163	BUG_ON(ret);
a28ec197 CM	164	if (root->commit_root != root->node) {
	165	struct tree_buffer *snap = root->commit_root;
	166	root->commit_root = root->node;
	167	root->node->count++;
	168	ret = btrfs_drop_snapshot(root, snap);
	169	BUG_ON(ret);
	170	tree_block_release(root, snap);
	171	}
	172	write_ctree_super(root, s);
	173	btrfs_finish_extent_commit(root);
ed2ff2cb CM	174	return ret;
	175	}
	176
d97e63b6 CM	177	static int __setup_root(struct ctree_root root, struct ctree_root extent_root,
	178	struct ctree_root_info *info, int fp)
	179	{
ed2ff2cb CM	180	INIT_LIST_HEAD(&root->trans);
ed2ff2cb CM	181	INIT_LIST_HEAD(&root->cache);
a28ec197	182	root->cache_size = 0;
d97e63b6	183	root->fp = fp;
cfaa7295	184	root->node = NULL;
d97e63b6	185	root->extent_root = extent_root;
a28ec197 CM	186	root->commit_root = NULL;
	187	root->node = read_tree_block(root, info->tree_root);
	188	memset(&root->current_insert, 0, sizeof(root->current_insert));
d97e63b6 CM	189	return 0;
	190	}
	191
cfaa7295	192	struct ctree_root open_ctree(char filename, struct ctree_super_block *super)
eb60ceac CM	193	{
eb60ceac CM	194	struct ctree_root *root = malloc(sizeof(struct ctree_root));
d97e63b6	195	struct ctree_root *extent_root = malloc(sizeof(struct ctree_root));
eb60ceac	196	int fp;
eb60ceac CM	197	int ret;
eb60ceac CM	198
c673024a	199	fp = open(filename, O_CREAT \| O_RDWR, 0600);
eb60ceac CM	200	if (fp < 0) {
	201	free(root);
	202	return NULL;
	203	}
9a8dd150	204	INIT_RADIX_TREE(&root->cache_radix, GFP_KERNEL);
a28ec197 CM	205	INIT_RADIX_TREE(&root->pinned_radix, GFP_KERNEL);
a28ec197 CM	206	INIT_RADIX_TREE(&extent_root->pinned_radix, GFP_KERNEL);
9a8dd150	207	INIT_RADIX_TREE(&extent_root->cache_radix, GFP_KERNEL);
cfaa7295	208	ret = pread(fp, super, sizeof(struct ctree_super_block),
d97e63b6	209	CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
5c680ed6 CM	210	if (ret == 0 \|\| super->root_info.tree_root == 0) {
5c680ed6 CM	211	printf("making new FS!\n");
d97e63b6 CM	212	ret = mkfs(fp);
	213	if (ret)
	214	return NULL;
cfaa7295	215	ret = pread(fp, super, sizeof(struct ctree_super_block),
d97e63b6 CM	216	CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
	217	if (ret != sizeof(struct ctree_super_block))
	218	return NULL;
	219	}
	220	BUG_ON(ret < 0);
cfaa7295 CM	221	__setup_root(root, extent_root, &super->root_info, fp);
cfaa7295 CM	222	__setup_root(extent_root, extent_root, &super->extent_info, fp);
a28ec197 CM	223	root->commit_root = root->node;
a28ec197 CM	224	root->node->count++;
eb60ceac CM	225	return root;
	226	}
	227
cfaa7295	228	static int __update_root(struct ctree_root root, struct ctree_root_info info)
eb60ceac	229	{
cfaa7295	230	info->tree_root = root->node->blocknr;
eb60ceac CM	231	return 0;
	232	}
	233
cfaa7295	234	int write_ctree_super(struct ctree_root root, struct ctree_super_block s)
eb60ceac CM	235	{
eb60ceac CM	236	int ret;
cfaa7295 CM	237	__update_root(root, &s->root_info);
	238	__update_root(root->extent_root, &s->extent_info);
	239	ret = pwrite(root->fp, s, sizeof(*s), CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
	240	if (ret != sizeof(*s)) {
	241	fprintf(stderr, "failed to write new super block err %d\n", ret);
eb60ceac	242	return ret;
cfaa7295 CM	243	}
	244	return 0;
	245	}
	246
ed2ff2cb CM	247	static int drop_cache(struct ctree_root *root)
	248	{
	249	while(!list_empty(&root->cache)) {
	250	struct tree_buffer *b = list_entry(root->cache.next,
	251	struct tree_buffer, cache);
	252	list_del_init(&b->cache);
	253	tree_block_release(root, b);
	254	}
	255	return 0;
	256	}
a28ec197	257	int close_ctree(struct ctree_root root, struct ctree_super_block s)
cfaa7295	258	{
a28ec197 CM	259	commit_transaction(root, s);
	260	__commit_transaction(root->extent_root);
	261	write_ctree_super(root, s);
ed2ff2cb CM	262	drop_cache(root->extent_root);
	263	drop_cache(root);
	264	BUG_ON(!list_empty(&root->trans));
	265	BUG_ON(!list_empty(&root->extent_root->trans));
	266
cfaa7295 CM	267	close(root->fp);
	268	if (root->node)
	269	tree_block_release(root, root->node);
	270	if (root->extent_root->node)
	271	tree_block_release(root->extent_root, root->extent_root->node);
a28ec197	272	tree_block_release(root, root->commit_root);
cfaa7295 CM	273	free(root);
cfaa7295 CM	274	printf("on close %d blocks are allocated\n", allocated_blocks);
eb60ceac CM	275	return 0;
	276	}
	277
	278	void tree_block_release(struct ctree_root root, struct tree_buffer buf)
	279	{
	280	buf->count--;
cfaa7295 CM	281	if (buf->count < 0)
cfaa7295 CM	282	BUG();
eb60ceac	283	if (buf->count == 0) {
02217ed2 CM	284	BUG_ON(!list_empty(&buf->cache));
02217ed2 CM	285	BUG_ON(!list_empty(&buf->dirty));
eb60ceac CM	286	if (!radix_tree_lookup(&root->cache_radix, buf->blocknr))
	287	BUG();
	288	radix_tree_delete(&root->cache_radix, buf->blocknr);
	289	memset(buf, 0, sizeof(*buf));
	290	free(buf);
	291	BUG_ON(allocated_blocks == 0);
	292	allocated_blocks--;
ed2ff2cb CM	293	BUG_ON(root->cache_size == 0);
ed2ff2cb CM	294	root->cache_size--;
eb60ceac CM	295	}
	296	}
	297