[linux-2.6-block.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) * 2) / \
			       BTRFS_CRC32_SIZE) - 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);
	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_set_file_extent_type(item, BTRFS_FILE_EXTENT_REG);
	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;
	int csums_in_item;

	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;
		csums_in_item = btrfs_item_size(leaf->items + path->slots[0]);
		csums_in_item /= BTRFS_CRC32_SIZE;

		if (csum_offset >= csums_in_item) {
			ret = -EFBIG;
			goto fail;
		}
	}
	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
	item = (struct btrfs_csum_item *)((unsigned char *)item +
					  csum_offset * BTRFS_CRC32_SIZE);
	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);

	file_key.objectid = objectid;
	file_key.offset = offset;
	file_key.flags = 0;
	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);

	item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
	if (!IS_ERR(item))
		goto found;
	ret = PTR_ERR(item);
	if (ret == -EFBIG) {
		u32 item_size;
		/* we found one, but it isn't big enough yet */
		leaf = btrfs_buffer_leaf(path->nodes[0]);
		item_size = btrfs_item_size(leaf->items + path->slots[0]);
		if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
			/* already at max size, make a new one */
			goto insert;
		}
	} else {
		/* we didn't find a csum item, insert one */
		goto insert;
	}

	/*
	 * at this point, we know the tree has an item, but it isn't big
	 * enough yet to put our csum in.  Grow it
	 */
	btrfs_release_path(root, path);
	ret = btrfs_search_slot(trans, root, &file_key, path,
				BTRFS_CRC32_SIZE, 1);
	if (ret < 0)
		goto fail;
	if (ret == 0) {
		BUG();
	}
	if (path->slots[0] == 0) {
		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)) {
		WARN_ON(1);
		goto insert;
	}
	if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
	    BTRFS_CRC32_SIZE) {
		u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
		diff = diff - btrfs_item_size(leaf->items + path->slots[0]);
		WARN_ON(diff != BTRFS_CRC32_SIZE);
		ret = btrfs_extend_item(trans, root, path, diff);
		BUG_ON(ret);
		goto csum;
	}

insert:
	btrfs_release_path(root, path);
	csum_offset = 0;
	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
				      BTRFS_CRC32_SIZE);
	if (ret != 0) {
		printk("at insert for %Lu %u %Lu ret is %d\n", file_key.objectid, file_key.flags, file_key.offset, ret);
		WARN_ON(1);
		goto fail;
	}
csum:
	item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
			      struct btrfs_csum_item);
	ret = 0;
	item = (struct btrfs_csum_item *)((unsigned char *)item +
					  csum_offset * BTRFS_CRC32_SIZE);
found:
	btrfs_check_bounds(&item->csum, BTRFS_CRC32_SIZE,
			   path->nodes[0]->b_data,
			   root->fs_info->sb->s_blocksize);
	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_CRC32_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);
		/* a csum that isn't present is a preallocated region. */
		if (ret == -ENOENT || ret == -EFBIG)
			ret = 1;
		goto fail;
	}

	ret = btrfs_csum_data(root, data, len, result);
	WARN_ON(ret);
	if (memcmp(result, &item->csum, BTRFS_CRC32_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	6	#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
509659cd CM	7	sizeof(struct btrfs_item) * 2) / \
509659cd CM	8	BTRFS_CRC32_SIZE) - 1))
b18c6685	9	int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
dee26a9f	10	struct btrfs_root *root,
b18c6685 CM	11	u64 objectid, u64 pos,
b18c6685 CM	12	u64 offset, u64 num_blocks)
9f5fae2f	13	{
dee26a9f CM	14	int ret = 0;
	15	struct btrfs_file_extent_item *item;
	16	struct btrfs_key file_key;
5caf2a00	17	struct btrfs_path *path;
dee26a9f	18
5caf2a00 CM	19	path = btrfs_alloc_path();
	20	BUG_ON(!path);
	21	btrfs_init_path(path);
dee26a9f	22	file_key.objectid = objectid;
b18c6685	23	file_key.offset = pos;
dee26a9f CM	24	file_key.flags = 0;
	25	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
	26
5caf2a00	27	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
dee26a9f	28	sizeof(*item));
9773a788	29	BUG_ON(ret);
5caf2a00	30	item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
dee26a9f	31	struct btrfs_file_extent_item);
b18c6685 CM	32	btrfs_set_file_extent_disk_blocknr(item, offset);
b18c6685 CM	33	btrfs_set_file_extent_disk_num_blocks(item, num_blocks);
dee26a9f	34	btrfs_set_file_extent_offset(item, 0);
b18c6685	35	btrfs_set_file_extent_num_blocks(item, num_blocks);
71951f35	36	btrfs_set_file_extent_generation(item, trans->transid);
236454df	37	btrfs_set_file_extent_type(item, BTRFS_FILE_EXTENT_REG);
5caf2a00	38	btrfs_mark_buffer_dirty(path->nodes[0]);
a429e513	39
5caf2a00 CM	40	btrfs_release_path(root, path);
5caf2a00 CM	41	btrfs_free_path(path);
9f5fae2f CM	42	return 0;
9f5fae2f CM	43	}
dee26a9f	44
b18c6685 CM	45	struct btrfs_csum_item btrfs_lookup_csum(struct btrfs_trans_handle trans,
	46	struct btrfs_root *root,
	47	struct btrfs_path *path,
	48	u64 objectid, u64 offset,
	49	int cow)
6567e837 CM	50	{
	51	int ret;
	52	struct btrfs_key file_key;
	53	struct btrfs_key found_key;
	54	struct btrfs_csum_item *item;
	55	struct btrfs_leaf *leaf;
	56	u64 csum_offset = 0;
a429e513	57	int csums_in_item;
6567e837 CM	58
	59	file_key.objectid = objectid;
	60	file_key.offset = offset;
	61	file_key.flags = 0;
	62	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
b18c6685	63	ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
6567e837 CM	64	if (ret < 0)
	65	goto fail;
	66	leaf = btrfs_buffer_leaf(path->nodes[0]);
	67	if (ret > 0) {
	68	ret = 1;
70b2befd	69	if (path->slots[0] == 0)
6567e837 CM	70	goto fail;
	71	path->slots[0]--;
	72	btrfs_disk_key_to_cpu(&found_key,
	73	&leaf->items[path->slots[0]].key);
	74	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY \|\|
	75	found_key.objectid != objectid) {
	76	goto fail;
	77	}
	78	csum_offset = (offset - found_key.offset) >>
	79	root->fs_info->sb->s_blocksize_bits;
a429e513	80	csums_in_item = btrfs_item_size(leaf->items + path->slots[0]);
509659cd	81	csums_in_item /= BTRFS_CRC32_SIZE;
a429e513 CM	82
	83	if (csum_offset >= csums_in_item) {
	84	ret = -EFBIG;
6567e837 CM	85	goto fail;
	86	}
	87	}
	88	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
509659cd CM	89	item = (struct btrfs_csum_item )((unsigned char )item +
509659cd CM	90	csum_offset * BTRFS_CRC32_SIZE);
6567e837 CM	91	return item;
	92	fail:
	93	if (ret > 0)
b18c6685	94	ret = -ENOENT;
6567e837 CM	95	return ERR_PTR(ret);
	96	}
	97
	98
dee26a9f CM	99	int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
	100	struct btrfs_root *root,
	101	struct btrfs_path *path, u64 objectid,
9773a788	102	u64 offset, int mod)
dee26a9f CM	103	{
	104	int ret;
	105	struct btrfs_key file_key;
	106	int ins_len = mod < 0 ? -1 : 0;
	107	int cow = mod != 0;
	108
	109	file_key.objectid = objectid;
70b2befd	110	file_key.offset = offset;
dee26a9f CM	111	file_key.flags = 0;
	112	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
	113	ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
	114	return ret;
	115	}
f254e52c CM	116
	117	int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
	118	struct btrfs_root *root,
	119	u64 objectid, u64 offset,
	120	char *data, size_t len)
	121	{
	122	int ret;
	123	struct btrfs_key file_key;
6567e837	124	struct btrfs_key found_key;
5caf2a00	125	struct btrfs_path *path;
f254e52c	126	struct btrfs_csum_item *item;
6567e837 CM	127	struct btrfs_leaf *leaf;
6567e837 CM	128	u64 csum_offset;
f254e52c	129
5caf2a00 CM	130	path = btrfs_alloc_path();
5caf2a00 CM	131	BUG_ON(!path);
b18c6685	132
f254e52c CM	133	file_key.objectid = objectid;
	134	file_key.offset = offset;
	135	file_key.flags = 0;
	136	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
a429e513 CM	137
	138	item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
	139	if (!IS_ERR(item))
	140	goto found;
	141	ret = PTR_ERR(item);
	142	if (ret == -EFBIG) {
	143	u32 item_size;
	144	/* we found one, but it isn't big enough yet */
	145	leaf = btrfs_buffer_leaf(path->nodes[0]);
	146	item_size = btrfs_item_size(leaf->items + path->slots[0]);
509659cd	147	if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
a429e513 CM	148	/* already at max size, make a new one */
	149	goto insert;
	150	}
	151	} else {
	152	/* we didn't find a csum item, insert one */
	153	goto insert;
	154	}
	155
	156	/*
	157	* at this point, we know the tree has an item, but it isn't big
	158	* enough yet to put our csum in. Grow it
	159	*/
	160	btrfs_release_path(root, path);
6567e837	161	ret = btrfs_search_slot(trans, root, &file_key, path,
509659cd	162	BTRFS_CRC32_SIZE, 1);
6567e837 CM	163	if (ret < 0)
	164	goto fail;
	165	if (ret == 0) {
b18c6685	166	BUG();
6567e837 CM	167	}
6567e837 CM	168	if (path->slots[0] == 0) {
6567e837 CM	169	goto insert;
	170	}
	171	path->slots[0]--;
	172	leaf = btrfs_buffer_leaf(path->nodes[0]);
	173	btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
	174	csum_offset = (offset - found_key.offset) >>
	175	root->fs_info->sb->s_blocksize_bits;
	176	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY \|\|
	177	found_key.objectid != objectid \|\|
	178	csum_offset >= MAX_CSUM_ITEMS(root)) {
a429e513	179	WARN_ON(1);
6567e837 CM	180	goto insert;
	181	}
	182	if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
509659cd CM	183	BTRFS_CRC32_SIZE) {
509659cd CM	184	u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
a429e513	185	diff = diff - btrfs_item_size(leaf->items + path->slots[0]);
509659cd	186	WARN_ON(diff != BTRFS_CRC32_SIZE);
a429e513	187	ret = btrfs_extend_item(trans, root, path, diff);
6567e837 CM	188	BUG_ON(ret);
	189	goto csum;
	190	}
	191
	192	insert:
a429e513	193	btrfs_release_path(root, path);
6567e837	194	csum_offset = 0;
5caf2a00	195	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
509659cd	196	BTRFS_CRC32_SIZE);
a429e513 CM	197	if (ret != 0) {
	198	printk("at insert for %Lu %u %Lu ret is %d\n", file_key.objectid, file_key.flags, file_key.offset, ret);
	199	WARN_ON(1);
f254e52c	200	goto fail;
a429e513	201	}
6567e837	202	csum:
5caf2a00	203	item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
f254e52c CM	204	struct btrfs_csum_item);
f254e52c CM	205	ret = 0;
509659cd CM	206	item = (struct btrfs_csum_item )((unsigned char )item +
509659cd CM	207	csum_offset * BTRFS_CRC32_SIZE);
b18c6685	208	found:
509659cd CM	209	btrfs_check_bounds(&item->csum, BTRFS_CRC32_SIZE,
	210	path->nodes[0]->b_data,
	211	root->fs_info->sb->s_blocksize);
	212	ret = btrfs_csum_data(root, data, len, &item->csum);
5caf2a00	213	btrfs_mark_buffer_dirty(path->nodes[0]);
f254e52c	214	fail:
5caf2a00 CM	215	btrfs_release_path(root, path);
5caf2a00 CM	216	btrfs_free_path(path);
f254e52c CM	217	return ret;
	218	}
	219
	220	int btrfs_csum_verify_file_block(struct btrfs_root *root,
	221	u64 objectid, u64 offset,
	222	char *data, size_t len)
	223	{
	224	int ret;
	225	struct btrfs_key file_key;
5caf2a00	226	struct btrfs_path *path;
f254e52c	227	struct btrfs_csum_item *item;
509659cd	228	char result[BTRFS_CRC32_SIZE];
f254e52c	229
5caf2a00 CM	230	path = btrfs_alloc_path();
	231	BUG_ON(!path);
	232	btrfs_init_path(path);
f254e52c CM	233	file_key.objectid = objectid;
	234	file_key.offset = offset;
	235	file_key.flags = 0;
	236	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
2da566ed	237	mutex_lock(&root->fs_info->fs_mutex);
6567e837	238
b18c6685	239	item = btrfs_lookup_csum(NULL, root, path, objectid, offset, 0);
6567e837 CM	240	if (IS_ERR(item)) {
6567e837 CM	241	ret = PTR_ERR(item);
a429e513 CM	242	/* a csum that isn't present is a preallocated region. */
	243	if (ret == -ENOENT \|\| ret == -EFBIG)
	244	ret = 1;
f254e52c	245	goto fail;
6567e837 CM	246	}
6567e837 CM	247
f254e52c CM	248	ret = btrfs_csum_data(root, data, len, result);
f254e52c CM	249	WARN_ON(ret);
509659cd	250	if (memcmp(result, &item->csum, BTRFS_CRC32_SIZE))
f254e52c CM	251	ret = 1;
f254e52c CM	252	fail:
5caf2a00 CM	253	btrfs_release_path(root, path);
5caf2a00 CM	254	btrfs_free_path(path);
2da566ed	255	mutex_unlock(&root->fs_info->fs_mutex);
f254e52c CM	256	return ret;
	257	}
	258