[deliverable/linux.git] / fs / btrfs / file-item.c

#include <linux/module.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"

#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
				 sizeof(struct btrfs_item)) / \
				sizeof(struct btrfs_csum_item)) - 1))
int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
			       struct btrfs_root *root,
			       u64 objectid, u64 pos,
			       u64 offset, u64 num_blocks)
{
	int ret = 0;
	struct btrfs_file_extent_item *item;
	struct btrfs_key file_key;
	struct btrfs_path *path;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	btrfs_init_path(path);
	/*
	ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block,
				 (u64)-1, &ins);
				 */
	BUG_ON(ret);
	file_key.objectid = objectid;
	file_key.offset = pos;
	file_key.flags = 0;
	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);

	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
				      sizeof(*item));
	BUG_ON(ret);
	item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
			      struct btrfs_file_extent_item);
	btrfs_set_file_extent_disk_blocknr(item, offset);
	btrfs_set_file_extent_disk_num_blocks(item, num_blocks);
	btrfs_set_file_extent_offset(item, 0);
	btrfs_set_file_extent_num_blocks(item, num_blocks);
	btrfs_set_file_extent_generation(item, trans->transid);
	btrfs_mark_buffer_dirty(path->nodes[0]);
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	return 0;
}

struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
					  struct btrfs_root *root,
					  struct btrfs_path *path,
					  u64 objectid, u64 offset,
					  int cow)
{
	int ret;
	struct btrfs_key file_key;
	struct btrfs_key found_key;
	struct btrfs_csum_item *item;
	struct btrfs_leaf *leaf;
	u64 csum_offset = 0;

	file_key.objectid = objectid;
	file_key.offset = offset;
	file_key.flags = 0;
	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
	ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
	if (ret < 0)
		goto fail;
	leaf = btrfs_buffer_leaf(path->nodes[0]);
	if (ret > 0) {
		ret = 1;
		if (path->slots[0] == 0)
			goto fail;
		path->slots[0]--;
		btrfs_disk_key_to_cpu(&found_key,
				      &leaf->items[path->slots[0]].key);
		if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
		    found_key.objectid != objectid) {
			goto fail;
		}
		csum_offset = (offset - found_key.offset) >>
				root->fs_info->sb->s_blocksize_bits;
		if (csum_offset >=
		    btrfs_item_size(leaf->items + path->slots[0]) /
		    sizeof(struct btrfs_csum_item)) {
			goto fail;
		}
	}
	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
	item += csum_offset;
	return item;
fail:
	if (ret > 0)
		ret = -ENOENT;
	return ERR_PTR(ret);
}


int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
			     struct btrfs_root *root,
			     struct btrfs_path *path, u64 objectid,
			     u64 offset, int mod)
{
	int ret;
	struct btrfs_key file_key;
	int ins_len = mod < 0 ? -1 : 0;
	int cow = mod != 0;

	file_key.objectid = objectid;
	file_key.offset = offset;
	file_key.flags = 0;
	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
	ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
	return ret;
}

int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
			  struct btrfs_root *root,
			  u64 objectid, u64 offset,
			  char *data, size_t len)
{
	int ret;
	struct btrfs_key file_key;
	struct btrfs_key found_key;
	struct btrfs_path *path;
	struct btrfs_csum_item *item;
	struct btrfs_leaf *leaf;
	u64 csum_offset;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	btrfs_init_path(path);

	item = btrfs_lookup_csum(trans, root, path, objectid, offset, 0);
	if (!IS_ERR(item))
		goto found;
	btrfs_release_path(root, path);
	file_key.objectid = objectid;
	file_key.offset = offset;
	file_key.flags = 0;
	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
	ret = btrfs_search_slot(trans, root, &file_key, path,
				sizeof(struct btrfs_csum_item), 1);
	if (ret < 0)
		goto fail;
	if (ret == 0) {
		BUG();
	}
	if (path->slots[0] == 0) {
		btrfs_release_path(root, path);
		goto insert;
	}
	path->slots[0]--;
	leaf = btrfs_buffer_leaf(path->nodes[0]);
	btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
	csum_offset = (offset - found_key.offset) >>
			root->fs_info->sb->s_blocksize_bits;
	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
	    found_key.objectid != objectid ||
	    csum_offset >= MAX_CSUM_ITEMS(root)) {
		btrfs_release_path(root, path);
		goto insert;
	}
	if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
	    sizeof(struct btrfs_csum_item)) {
		ret = btrfs_extend_item(trans, root, path,
					sizeof(struct btrfs_csum_item));
		BUG_ON(ret);
		goto csum;
	}

insert:
	csum_offset = 0;
	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
				      sizeof(struct btrfs_csum_item));
	if (ret != 0 && ret != -EEXIST)
		goto fail;
csum:
	item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
			      struct btrfs_csum_item);
	ret = 0;
	item += csum_offset;
found:
	ret = btrfs_csum_data(root, data, len, item->csum);
	btrfs_mark_buffer_dirty(path->nodes[0]);
fail:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	return ret;
}

int btrfs_csum_verify_file_block(struct btrfs_root *root,
				 u64 objectid, u64 offset,
				 char *data, size_t len)
{
	int ret;
	struct btrfs_key file_key;
	struct btrfs_path *path;
	struct btrfs_csum_item *item;
	char result[BTRFS_CSUM_SIZE];

	path = btrfs_alloc_path();
	BUG_ON(!path);
	btrfs_init_path(path);
	file_key.objectid = objectid;
	file_key.offset = offset;
	file_key.flags = 0;
	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
	mutex_lock(&root->fs_info->fs_mutex);

	item = btrfs_lookup_csum(NULL, root, path, objectid, offset, 0);
	if (IS_ERR(item)) {
		ret = PTR_ERR(item);
		goto fail;
	}

	ret = btrfs_csum_data(root, data, len, result);
	WARN_ON(ret);
	if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))
		ret = 1;
fail:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	mutex_unlock(&root->fs_info->fs_mutex);
	return ret;
}
Commit	Line	Data
	1	#include <linux/module.h>
	2	#include "ctree.h"
	3	#include "disk-io.h"
	4	#include "transaction.h"
	5
	6	#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
	7	sizeof(struct btrfs_item)) / \
	8	sizeof(struct btrfs_csum_item)) - 1))
	9	int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
	10	struct btrfs_root *root,
	11	u64 objectid, u64 pos,
	12	u64 offset, u64 num_blocks)
	13	{
	14	int ret = 0;
	15	struct btrfs_file_extent_item *item;
	16	struct btrfs_key file_key;
	17	struct btrfs_path *path;
	18
	19	path = btrfs_alloc_path();
	20	BUG_ON(!path);
	21	btrfs_init_path(path);
	22	/*
	23	ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block,
	24	(u64)-1, &ins);
	25	*/
	26	BUG_ON(ret);
	27	file_key.objectid = objectid;
	28	file_key.offset = pos;
	29	file_key.flags = 0;
	30	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
	31
	32	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
	33	sizeof(*item));
	34	BUG_ON(ret);
	35	item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
	36	struct btrfs_file_extent_item);
	37	btrfs_set_file_extent_disk_blocknr(item, offset);
	38	btrfs_set_file_extent_disk_num_blocks(item, num_blocks);
	39	btrfs_set_file_extent_offset(item, 0);
	40	btrfs_set_file_extent_num_blocks(item, num_blocks);
	41	btrfs_set_file_extent_generation(item, trans->transid);
	42	btrfs_mark_buffer_dirty(path->nodes[0]);
	43	btrfs_release_path(root, path);
	44	btrfs_free_path(path);
	45	return 0;
	46	}
	47
	48	struct btrfs_csum_item btrfs_lookup_csum(struct btrfs_trans_handle trans,
	49	struct btrfs_root *root,
	50	struct btrfs_path *path,
	51	u64 objectid, u64 offset,
	52	int cow)
	53	{
	54	int ret;
	55	struct btrfs_key file_key;
	56	struct btrfs_key found_key;
	57	struct btrfs_csum_item *item;
	58	struct btrfs_leaf *leaf;
	59	u64 csum_offset = 0;
	60
	61	file_key.objectid = objectid;
	62	file_key.offset = offset;
	63	file_key.flags = 0;
	64	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
	65	ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
	66	if (ret < 0)
	67	goto fail;
	68	leaf = btrfs_buffer_leaf(path->nodes[0]);
	69	if (ret > 0) {
	70	ret = 1;
	71	if (path->slots[0] == 0)
	72	goto fail;
	73	path->slots[0]--;
	74	btrfs_disk_key_to_cpu(&found_key,
	75	&leaf->items[path->slots[0]].key);
	76	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY \|\|
	77	found_key.objectid != objectid) {
	78	goto fail;
	79	}
	80	csum_offset = (offset - found_key.offset) >>
	81	root->fs_info->sb->s_blocksize_bits;
	82	if (csum_offset >=
	83	btrfs_item_size(leaf->items + path->slots[0]) /
	84	sizeof(struct btrfs_csum_item)) {
	85	goto fail;
	86	}
	87	}
	88	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
	89	item += csum_offset;
	90	return item;
	91	fail:
	92	if (ret > 0)
	93	ret = -ENOENT;
	94	return ERR_PTR(ret);
	95	}
	96
	97
	98	int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
	99	struct btrfs_root *root,
	100	struct btrfs_path *path, u64 objectid,
	101	u64 offset, int mod)
	102	{
	103	int ret;
	104	struct btrfs_key file_key;
	105	int ins_len = mod < 0 ? -1 : 0;
	106	int cow = mod != 0;
	107
	108	file_key.objectid = objectid;
	109	file_key.offset = offset;
	110	file_key.flags = 0;
	111	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
	112	ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
	113	return ret;
	114	}
	115
	116	int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
	117	struct btrfs_root *root,
	118	u64 objectid, u64 offset,
	119	char *data, size_t len)
	120	{
	121	int ret;
	122	struct btrfs_key file_key;
	123	struct btrfs_key found_key;
	124	struct btrfs_path *path;
	125	struct btrfs_csum_item *item;
	126	struct btrfs_leaf *leaf;
	127	u64 csum_offset;
	128
	129	path = btrfs_alloc_path();
	130	BUG_ON(!path);
	131	btrfs_init_path(path);
	132
	133	item = btrfs_lookup_csum(trans, root, path, objectid, offset, 0);
	134	if (!IS_ERR(item))
	135	goto found;
	136	btrfs_release_path(root, path);
	137	file_key.objectid = objectid;
	138	file_key.offset = offset;
	139	file_key.flags = 0;
	140	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
	141	ret = btrfs_search_slot(trans, root, &file_key, path,
	142	sizeof(struct btrfs_csum_item), 1);
	143	if (ret < 0)
	144	goto fail;
	145	if (ret == 0) {
	146	BUG();
	147	}
	148	if (path->slots[0] == 0) {
	149	btrfs_release_path(root, path);
	150	goto insert;
	151	}
	152	path->slots[0]--;
	153	leaf = btrfs_buffer_leaf(path->nodes[0]);
	154	btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
	155	csum_offset = (offset - found_key.offset) >>
	156	root->fs_info->sb->s_blocksize_bits;
	157	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY \|\|
	158	found_key.objectid != objectid \|\|
	159	csum_offset >= MAX_CSUM_ITEMS(root)) {
	160	btrfs_release_path(root, path);
	161	goto insert;
	162	}
	163	if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
	164	sizeof(struct btrfs_csum_item)) {
	165	ret = btrfs_extend_item(trans, root, path,
	166	sizeof(struct btrfs_csum_item));
	167	BUG_ON(ret);
	168	goto csum;
	169	}
	170
	171	insert:
	172	csum_offset = 0;
	173	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
	174	sizeof(struct btrfs_csum_item));
	175	if (ret != 0 && ret != -EEXIST)
	176	goto fail;
	177	csum:
	178	item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
	179	struct btrfs_csum_item);
	180	ret = 0;
	181	item += csum_offset;
	182	found:
	183	ret = btrfs_csum_data(root, data, len, item->csum);
	184	btrfs_mark_buffer_dirty(path->nodes[0]);
	185	fail:
	186	btrfs_release_path(root, path);
	187	btrfs_free_path(path);
	188	return ret;
	189	}
	190
	191	int btrfs_csum_verify_file_block(struct btrfs_root *root,
	192	u64 objectid, u64 offset,
	193	char *data, size_t len)
	194	{
	195	int ret;
	196	struct btrfs_key file_key;
	197	struct btrfs_path *path;
	198	struct btrfs_csum_item *item;
	199	char result[BTRFS_CSUM_SIZE];
	200
	201	path = btrfs_alloc_path();
	202	BUG_ON(!path);
	203	btrfs_init_path(path);
	204	file_key.objectid = objectid;
	205	file_key.offset = offset;
	206	file_key.flags = 0;
	207	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
	208	mutex_lock(&root->fs_info->fs_mutex);
	209
	210	item = btrfs_lookup_csum(NULL, root, path, objectid, offset, 0);
	211	if (IS_ERR(item)) {
	212	ret = PTR_ERR(item);
	213	goto fail;
	214	}
	215
	216	ret = btrfs_csum_data(root, data, len, result);
	217	WARN_ON(ret);
	218	if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))
	219	ret = 1;
	220	fail:
	221	btrfs_release_path(root, path);
	222	btrfs_free_path(path);
	223	mutex_unlock(&root->fs_info->fs_mutex);
	224	return ret;
	225	}
	226