[GitHub/mt8127/android_kernel_alcatel_ttab.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_alloc_file_extent(struct btrfs_trans_handle *trans,
			       struct btrfs_root *root,
			       u64 objectid, u64 offset,
			       u64 num_blocks, u64 hint_block,
			       u64 *result)
{
	struct btrfs_key ins;
	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 = offset;
	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, ins.objectid);
	btrfs_set_file_extent_disk_num_blocks(item, ins.offset);
	btrfs_set_file_extent_offset(item, 0);
	btrfs_set_file_extent_num_blocks(item, ins.offset);
	btrfs_set_file_extent_generation(item, trans->transid);
	btrfs_mark_buffer_dirty(path->nodes[0]);
	*result = ins.objectid;
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	return 0;
}

static struct btrfs_csum_item *__lookup_csum_item(struct btrfs_root *root,
						  struct btrfs_path *path,
						  u64 objectid, u64 offset)
{
	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(NULL, root, &file_key, path, 0, 0);
	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 = -EIO;
	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;
	struct btrfs_csum_item *csum_item;

	csum_item = __lookup_csum_item(root, path, objectid, offset);
	if (IS_ERR(csum_item))
		return PTR_ERR(csum_item);
	file_key.objectid = objectid;
	file_key.offset = btrfs_csum_extent_offset(csum_item);
	file_key.flags = 0;
	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
	btrfs_release_path(root, path);
	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,
			  u64 extent_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);
	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) {
		csum_offset = 0;
		goto csum;
	}
	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;
	ret = btrfs_csum_data(root, data, len, item->csum);
	btrfs_set_csum_extent_offset(item, extent_offset);
	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 = __lookup_csum_item(root, path, objectid, offset);
	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
2e635a27	1	#include <linux/module.h>
1e1d2701	2	#include "ctree.h"
dee26a9f	3	#include "disk-io.h"
9f5fae2f	4	#include "transaction.h"
1e1d2701	5
6567e837 CM	6	#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
	7	sizeof(struct btrfs_item)) / \
	8	sizeof(struct btrfs_csum_item)) - 1))
dee26a9f CM	9	int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
	10	struct btrfs_root *root,
	11	u64 objectid, u64 offset,
	12	u64 num_blocks, u64 hint_block,
	13	u64 *result)
9f5fae2f	14	{
dee26a9f CM	15	struct btrfs_key ins;
	16	int ret = 0;
	17	struct btrfs_file_extent_item *item;
	18	struct btrfs_key file_key;
5caf2a00	19	struct btrfs_path *path;
dee26a9f	20
5caf2a00 CM	21	path = btrfs_alloc_path();
	22	BUG_ON(!path);
	23	btrfs_init_path(path);
dee26a9f	24	ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block,
d0dbc624	25	(u64)-1, &ins);
dee26a9f CM	26	BUG_ON(ret);
	27	file_key.objectid = objectid;
	28	file_key.offset = offset;
	29	file_key.flags = 0;
	30	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
	31
5caf2a00	32	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
dee26a9f	33	sizeof(*item));
9773a788	34	BUG_ON(ret);
5caf2a00	35	item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
dee26a9f CM	36	struct btrfs_file_extent_item);
	37	btrfs_set_file_extent_disk_blocknr(item, ins.objectid);
	38	btrfs_set_file_extent_disk_num_blocks(item, ins.offset);
	39	btrfs_set_file_extent_offset(item, 0);
	40	btrfs_set_file_extent_num_blocks(item, ins.offset);
71951f35	41	btrfs_set_file_extent_generation(item, trans->transid);
5caf2a00	42	btrfs_mark_buffer_dirty(path->nodes[0]);
dee26a9f	43	*result = ins.objectid;
5caf2a00 CM	44	btrfs_release_path(root, path);
5caf2a00 CM	45	btrfs_free_path(path);
9f5fae2f CM	46	return 0;
9f5fae2f CM	47	}
dee26a9f	48
6567e837 CM	49	static struct btrfs_csum_item __lookup_csum_item(struct btrfs_root root,
	50	struct btrfs_path *path,
	51	u64 objectid, u64 offset)
	52	{
	53	int ret;
	54	struct btrfs_key file_key;
	55	struct btrfs_key found_key;
	56	struct btrfs_csum_item *item;
	57	struct btrfs_leaf *leaf;
	58	u64 csum_offset = 0;
	59
	60	file_key.objectid = objectid;
	61	file_key.offset = offset;
	62	file_key.flags = 0;
	63	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
	64	ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0);
	65	if (ret < 0)
	66	goto fail;
	67	leaf = btrfs_buffer_leaf(path->nodes[0]);
	68	if (ret > 0) {
	69	ret = 1;
	70	if (path->slots[0] == 0)
	71	goto fail;
	72	path->slots[0]--;
	73	btrfs_disk_key_to_cpu(&found_key,
	74	&leaf->items[path->slots[0]].key);
	75	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY \|\|
	76	found_key.objectid != objectid) {
	77	goto fail;
	78	}
	79	csum_offset = (offset - found_key.offset) >>
	80	root->fs_info->sb->s_blocksize_bits;
	81	if (csum_offset >=
	82	btrfs_item_size(leaf->items + path->slots[0]) /
	83	sizeof(struct btrfs_csum_item)) {
	84	goto fail;
	85	}
	86	}
	87	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
	88	item += csum_offset;
	89	return item;
	90	fail:
	91	if (ret > 0)
	92	ret = -EIO;
	93	return ERR_PTR(ret);
	94	}
	95
	96
dee26a9f CM	97	int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
	98	struct btrfs_root *root,
	99	struct btrfs_path *path, u64 objectid,
9773a788	100	u64 offset, int mod)
dee26a9f CM	101	{
	102	int ret;
	103	struct btrfs_key file_key;
	104	int ins_len = mod < 0 ? -1 : 0;
	105	int cow = mod != 0;
6567e837	106	struct btrfs_csum_item *csum_item;
dee26a9f	107
6567e837 CM	108	csum_item = __lookup_csum_item(root, path, objectid, offset);
	109	if (IS_ERR(csum_item))
	110	return PTR_ERR(csum_item);
dee26a9f	111	file_key.objectid = objectid;
6567e837	112	file_key.offset = btrfs_csum_extent_offset(csum_item);
dee26a9f CM	113	file_key.flags = 0;
dee26a9f CM	114	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
6567e837	115	btrfs_release_path(root, path);
dee26a9f CM	116	ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
	117	return ret;
	118	}
f254e52c CM	119
	120	int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
	121	struct btrfs_root *root,
	122	u64 objectid, u64 offset,
6567e837	123	u64 extent_offset,
f254e52c CM	124	char *data, size_t len)
	125	{
	126	int ret;
	127	struct btrfs_key file_key;
6567e837	128	struct btrfs_key found_key;
5caf2a00	129	struct btrfs_path *path;
f254e52c	130	struct btrfs_csum_item *item;
6567e837 CM	131	struct btrfs_leaf *leaf;
6567e837 CM	132	u64 csum_offset;
f254e52c	133
5caf2a00 CM	134	path = btrfs_alloc_path();
	135	BUG_ON(!path);
	136	btrfs_init_path(path);
f254e52c CM	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);
6567e837 CM	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	csum_offset = 0;
	147	goto csum;
	148	}
	149	if (path->slots[0] == 0) {
	150	btrfs_release_path(root, path);
	151	goto insert;
	152	}
	153	path->slots[0]--;
	154	leaf = btrfs_buffer_leaf(path->nodes[0]);
	155	btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
	156	csum_offset = (offset - found_key.offset) >>
	157	root->fs_info->sb->s_blocksize_bits;
	158	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY \|\|
	159	found_key.objectid != objectid \|\|
	160	csum_offset >= MAX_CSUM_ITEMS(root)) {
	161	btrfs_release_path(root, path);
	162	goto insert;
	163	}
	164	if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
	165	sizeof(struct btrfs_csum_item)) {
	166	ret = btrfs_extend_item(trans, root, path,
	167	sizeof(struct btrfs_csum_item));
	168	BUG_ON(ret);
	169	goto csum;
	170	}
	171
	172	insert:
	173	csum_offset = 0;
5caf2a00	174	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
6567e837	175	sizeof(struct btrfs_csum_item));
f254e52c CM	176	if (ret != 0 && ret != -EEXIST)
f254e52c CM	177	goto fail;
6567e837	178	csum:
5caf2a00	179	item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
f254e52c CM	180	struct btrfs_csum_item);
f254e52c CM	181	ret = 0;
6567e837	182	item += csum_offset;
f254e52c	183	ret = btrfs_csum_data(root, data, len, item->csum);
6567e837	184	btrfs_set_csum_extent_offset(item, extent_offset);
5caf2a00	185	btrfs_mark_buffer_dirty(path->nodes[0]);
f254e52c	186	fail:
5caf2a00 CM	187	btrfs_release_path(root, path);
5caf2a00 CM	188	btrfs_free_path(path);
f254e52c CM	189	return ret;
	190	}
	191
	192	int btrfs_csum_verify_file_block(struct btrfs_root *root,
	193	u64 objectid, u64 offset,
	194	char *data, size_t len)
	195	{
	196	int ret;
	197	struct btrfs_key file_key;
5caf2a00	198	struct btrfs_path *path;
f254e52c CM	199	struct btrfs_csum_item *item;
	200	char result[BTRFS_CSUM_SIZE];
	201
5caf2a00 CM	202	path = btrfs_alloc_path();
	203	BUG_ON(!path);
	204	btrfs_init_path(path);
f254e52c CM	205	file_key.objectid = objectid;
	206	file_key.offset = offset;
	207	file_key.flags = 0;
	208	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
2da566ed	209	mutex_lock(&root->fs_info->fs_mutex);
6567e837 CM	210
	211	item = __lookup_csum_item(root, path, objectid, offset);
	212	if (IS_ERR(item)) {
	213	ret = PTR_ERR(item);
f254e52c	214	goto fail;
6567e837 CM	215	}
6567e837 CM	216
f254e52c CM	217	ret = btrfs_csum_data(root, data, len, result);
	218	WARN_ON(ret);
	219	if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))
	220	ret = 1;
	221	fail:
5caf2a00 CM	222	btrfs_release_path(root, path);
5caf2a00 CM	223	btrfs_free_path(path);
2da566ed	224	mutex_unlock(&root->fs_info->fs_mutex);
f254e52c CM	225	return ret;
	226	}
	227