[mirror_ubuntu-artful-kernel.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) / \
				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);
	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;
	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 /= sizeof(struct btrfs_csum_item);

		if (csum_offset >= csums_in_item) {
			ret = -EFBIG;
			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);

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