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

/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/bio.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "print-tree.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 disk_offset, u64 disk_num_bytes,
			     u64 num_bytes, u64 offset)
{
	int ret = 0;
	struct btrfs_file_extent_item *item;
	struct btrfs_key file_key;
	struct btrfs_path *path;
	struct extent_buffer *leaf;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	file_key.objectid = objectid;
	file_key.offset = pos;
	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);

	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
				      sizeof(*item));
	if (ret < 0)
		goto out;
	BUG_ON(ret);
	leaf = path->nodes[0];
	item = btrfs_item_ptr(leaf, path->slots[0],
			      struct btrfs_file_extent_item);
	btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
	btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
	btrfs_set_file_extent_offset(leaf, item, offset);
	btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
	btrfs_set_file_extent_generation(leaf, item, trans->transid);
	btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
	btrfs_mark_buffer_dirty(leaf);
out:
	btrfs_free_path(path);
	return ret;
}

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 extent_buffer *leaf;
	u64 csum_offset = 0;
	int csums_in_item;

	file_key.objectid = objectid;
	file_key.offset = offset;
	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 = path->nodes[0];
	if (ret > 0) {
		ret = 1;
		if (path->slots[0] == 0)
			goto fail;
		path->slots[0]--;
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
		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_nr(leaf, 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;
	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_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
			  struct bio *bio)
{
	u32 sum;
	struct bio_vec *bvec = bio->bi_io_vec;
	int bio_index = 0;
	u64 offset;
	u64 item_start_offset = 0;
	u64 item_last_offset = 0;
	u32 diff;
	int ret;
	struct btrfs_path *path;
	struct btrfs_csum_item *item = NULL;
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;

	path = btrfs_alloc_path();

	WARN_ON(bio->bi_vcnt <= 0);

	while(bio_index < bio->bi_vcnt) {
		offset = page_offset(bvec->bv_page) + bvec->bv_offset;
		ret = btrfs_find_ordered_sum(inode, offset, &sum);
		if (ret == 0)
			goto found;

		if (!item || offset < item_start_offset ||
		    offset >= item_last_offset) {
			struct btrfs_key found_key;
			u32 item_size;

			if (item)
				btrfs_release_path(root, path);
			item = btrfs_lookup_csum(NULL, root, path,
						 inode->i_ino, offset, 0);
			if (IS_ERR(item)) {
				ret = PTR_ERR(item);
				if (ret == -ENOENT || ret == -EFBIG)
					ret = 0;
				sum = 0;
				printk("no csum found for inode %lu start "
				       "%llu\n", inode->i_ino,
				       (unsigned long long)offset);
				item = NULL;
				goto found;
			}
			btrfs_item_key_to_cpu(path->nodes[0], &found_key,
					      path->slots[0]);

			item_start_offset = found_key.offset;
			item_size = btrfs_item_size_nr(path->nodes[0],
						       path->slots[0]);
			item_last_offset = item_start_offset +
				(item_size / BTRFS_CRC32_SIZE) *
				root->sectorsize;
			item = btrfs_item_ptr(path->nodes[0], path->slots[0],
					      struct btrfs_csum_item);
		}
		/*
		 * this byte range must be able to fit inside
		 * a single leaf so it will also fit inside a u32
		 */
		diff = offset - item_start_offset;
		diff = diff / root->sectorsize;
		diff = diff * BTRFS_CRC32_SIZE;

		read_extent_buffer(path->nodes[0], &sum,
				   (unsigned long)item + diff,
				   BTRFS_CRC32_SIZE);
found:
		set_state_private(io_tree, offset, sum);
		bio_index++;
		bvec++;
	}
	btrfs_free_path(path);
	return 0;
}

int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
		       struct bio *bio)
{
	struct btrfs_ordered_sum *sums;
	struct btrfs_sector_sum *sector_sum;
	struct btrfs_ordered_extent *ordered;
	char *data;
	struct bio_vec *bvec = bio->bi_io_vec;
	int bio_index = 0;
	unsigned long total_bytes = 0;
	unsigned long this_sum_bytes = 0;
	u64 offset;

	WARN_ON(bio->bi_vcnt <= 0);
	sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
	if (!sums)
		return -ENOMEM;

	sector_sum = sums->sums;
	sums->file_offset = page_offset(bvec->bv_page) + bvec->bv_offset;
	sums->len = bio->bi_size;
	INIT_LIST_HEAD(&sums->list);
	ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
	BUG_ON(!ordered);

	while(bio_index < bio->bi_vcnt) {
		offset = page_offset(bvec->bv_page) + bvec->bv_offset;
		if (offset >= ordered->file_offset + ordered->len ||
		    offset < ordered->file_offset) {
			unsigned long bytes_left;
			sums->len = this_sum_bytes;
			this_sum_bytes = 0;
			btrfs_add_ordered_sum(inode, ordered, sums);
			btrfs_put_ordered_extent(ordered);

			bytes_left = bio->bi_size - total_bytes;

			sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
				       GFP_NOFS);
			BUG_ON(!sums);
			sector_sum = sums->sums;
			sums->len = bytes_left;
			sums->file_offset = offset;
			ordered = btrfs_lookup_ordered_extent(inode,
						      sums->file_offset);
			BUG_ON(!ordered);
		}

		data = kmap_atomic(bvec->bv_page, KM_USER0);
		sector_sum->sum = ~(u32)0;
		sector_sum->sum = btrfs_csum_data(root,
						  data + bvec->bv_offset,
						  sector_sum->sum,
						  bvec->bv_len);
		kunmap_atomic(data, KM_USER0);
		btrfs_csum_final(sector_sum->sum,
				 (char *)&sector_sum->sum);
		sector_sum->offset = page_offset(bvec->bv_page) +
			bvec->bv_offset;

		sector_sum++;
		bio_index++;
		total_bytes += bvec->bv_len;
		this_sum_bytes += bvec->bv_len;
		bvec++;
	}
	this_sum_bytes = 0;
	btrfs_add_ordered_sum(inode, ordered, sums);
	btrfs_put_ordered_extent(ordered);
	return 0;
}

int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
			   struct btrfs_root *root, struct inode *inode,
			   struct btrfs_ordered_sum *sums)
{
	u64 objectid = inode->i_ino;
	u64 offset;
	int ret;
	struct btrfs_key file_key;
	struct btrfs_key found_key;
	u64 next_offset;
	u64 total_bytes = 0;
	int found_next;
	struct btrfs_path *path;
	struct btrfs_csum_item *item;
	struct btrfs_csum_item *item_end;
	struct extent_buffer *leaf = NULL;
	u64 csum_offset;
	struct btrfs_sector_sum *sector_sum;
	u32 nritems;
	u32 ins_size;
	char *eb_map;
	char *eb_token;
	unsigned long map_len;
	unsigned long map_start;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	sector_sum = sums->sums;
again:
	next_offset = (u64)-1;
	found_next = 0;
	offset = sector_sum->offset;
	file_key.objectid = objectid;
	file_key.offset = offset;
	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);

	item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
	if (!IS_ERR(item)) {
		leaf = path->nodes[0];
		goto found;
	}
	ret = PTR_ERR(item);
	if (ret == -EFBIG) {
		u32 item_size;
		/* we found one, but it isn't big enough yet */
		leaf = path->nodes[0];
		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
		if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
			/* already at max size, make a new one */
			goto insert;
		}
	} else {
		int slot = path->slots[0] + 1;
		/* we didn't find a csum item, insert one */
		nritems = btrfs_header_nritems(path->nodes[0]);
		if (path->slots[0] >= nritems - 1) {
			ret = btrfs_next_leaf(root, path);
			if (ret == 1)
				found_next = 1;
			if (ret != 0)
				goto insert;
			slot = 0;
		}
		btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
		if (found_key.objectid != objectid ||
		    found_key.type != BTRFS_CSUM_ITEM_KEY) {
			found_next = 1;
			goto insert;
		}
		next_offset = found_key.offset;
		found_next = 1;
		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 = path->nodes[0];
	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
	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)) {
		goto insert;
	}
	if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
	    BTRFS_CRC32_SIZE) {
		u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
		diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
		if (diff != BTRFS_CRC32_SIZE)
			goto insert;
		ret = btrfs_extend_item(trans, root, path, diff);
		BUG_ON(ret);
		goto csum;
	}

insert:
	btrfs_release_path(root, path);
	csum_offset = 0;
	if (found_next) {
		u64 tmp = min((u64)i_size_read(inode), next_offset);
		tmp -= offset & ~((u64)root->sectorsize -1);
		tmp >>= root->fs_info->sb->s_blocksize_bits;
		tmp = max((u64)1, tmp);
		tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root));
		ins_size = BTRFS_CRC32_SIZE * tmp;
	} else {
		ins_size = BTRFS_CRC32_SIZE;
	}
	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
				      ins_size);
	if (ret < 0)
		goto fail;
	if (ret != 0) {
		WARN_ON(1);
		goto fail;
	}
csum:
	leaf = path->nodes[0];
	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
	ret = 0;
	item = (struct btrfs_csum_item *)((unsigned char *)item +
					  csum_offset * BTRFS_CRC32_SIZE);
found:
	item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
	item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
				      btrfs_item_size_nr(leaf, path->slots[0]));
	eb_token = NULL;
next_sector:

	if (!eb_token ||
	   (unsigned long)item  + BTRFS_CRC32_SIZE >= map_start + map_len) {
		int err;

		if (eb_token)
			unmap_extent_buffer(leaf, eb_token, KM_USER1);
		eb_token = NULL;
		err = map_private_extent_buffer(leaf, (unsigned long)item,
						BTRFS_CRC32_SIZE,
						&eb_token, &eb_map,
						&map_start, &map_len, KM_USER1);
		if (err)
			eb_token = NULL;
	}
	if (eb_token) {
		memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
		       &sector_sum->sum, BTRFS_CRC32_SIZE);
	} else {
		write_extent_buffer(leaf, &sector_sum->sum,
				    (unsigned long)item, BTRFS_CRC32_SIZE);
	}

	total_bytes += root->sectorsize;
	sector_sum++;
	if (total_bytes < sums->len) {
		item = (struct btrfs_csum_item *)((char *)item +
						  BTRFS_CRC32_SIZE);
		if (item < item_end && offset + PAGE_CACHE_SIZE ==
		    sector_sum->offset) {
			    offset = sector_sum->offset;
			goto next_sector;
		}
	}
	if (eb_token) {
		unmap_extent_buffer(leaf, eb_token, KM_USER1);
		eb_token = NULL;
	}
	btrfs_mark_buffer_dirty(path->nodes[0]);
	if (total_bytes < sums->len) {
		btrfs_release_path(root, path);
		goto again;
	}
fail:
	btrfs_free_path(path);
	return ret;
}

int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
			struct btrfs_root *root, struct btrfs_path *path,
			u64 isize)
{
	struct btrfs_key key;
	struct extent_buffer *leaf = path->nodes[0];
	int slot = path->slots[0];
	int ret;
	u32 new_item_size;
	u64 new_item_span;
	u64 blocks;

	btrfs_item_key_to_cpu(leaf, &key, slot);
	if (isize <= key.offset)
		return 0;
	new_item_span = isize - key.offset;
	blocks = (new_item_span + root->sectorsize - 1) >>
		root->fs_info->sb->s_blocksize_bits;
	new_item_size = blocks * BTRFS_CRC32_SIZE;
	if (new_item_size >= btrfs_item_size_nr(leaf, slot))
		return 0;
	ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);
	BUG_ON(ret);
	return ret;
}
Commit	Line	Data
6cbd5570 CM	1	/*
	2	* Copyright (C) 2007 Oracle. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public
	6	* License v2 as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU General Public
	14	* License along with this program; if not, write to the
	15	* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	16	* Boston, MA 021110-1307, USA.
	17	*/
	18
065631f6 CM	19	#include <linux/bio.h>
	20	#include <linux/pagemap.h>
	21	#include <linux/highmem.h>
1e1d2701	22	#include "ctree.h"
dee26a9f	23	#include "disk-io.h"
9f5fae2f	24	#include "transaction.h"
1de037a4	25	#include "print-tree.h"
1e1d2701	26
6567e837	27	#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
509659cd CM	28	sizeof(struct btrfs_item) * 2) / \
509659cd CM	29	BTRFS_CRC32_SIZE) - 1))
b18c6685	30	int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
f2eb0a24 SW	31	struct btrfs_root *root,
	32	u64 objectid, u64 pos,
	33	u64 disk_offset, u64 disk_num_bytes,
	34	u64 num_bytes, u64 offset)
9f5fae2f	35	{
dee26a9f CM	36	int ret = 0;
	37	struct btrfs_file_extent_item *item;
	38	struct btrfs_key file_key;
5caf2a00	39	struct btrfs_path *path;
5f39d397	40	struct extent_buffer *leaf;
dee26a9f	41
5caf2a00 CM	42	path = btrfs_alloc_path();
5caf2a00 CM	43	BUG_ON(!path);
dee26a9f	44	file_key.objectid = objectid;
b18c6685	45	file_key.offset = pos;
dee26a9f CM	46	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
dee26a9f CM	47
5caf2a00	48	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
dee26a9f	49	sizeof(*item));
54aa1f4d CM	50	if (ret < 0)
54aa1f4d CM	51	goto out;
9773a788	52	BUG_ON(ret);
5f39d397 CM	53	leaf = path->nodes[0];
5f39d397 CM	54	item = btrfs_item_ptr(leaf, path->slots[0],
dee26a9f	55	struct btrfs_file_extent_item);
f2eb0a24	56	btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
db94535d	57	btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
f2eb0a24	58	btrfs_set_file_extent_offset(leaf, item, offset);
db94535d	59	btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
5f39d397 CM	60	btrfs_set_file_extent_generation(leaf, item, trans->transid);
	61	btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
	62	btrfs_mark_buffer_dirty(leaf);
54aa1f4d	63	out:
5caf2a00	64	btrfs_free_path(path);
54aa1f4d	65	return ret;
9f5fae2f	66	}
dee26a9f	67
b18c6685 CM	68	struct btrfs_csum_item btrfs_lookup_csum(struct btrfs_trans_handle trans,
	69	struct btrfs_root *root,
	70	struct btrfs_path *path,
	71	u64 objectid, u64 offset,
	72	int cow)
6567e837 CM	73	{
	74	int ret;
	75	struct btrfs_key file_key;
	76	struct btrfs_key found_key;
	77	struct btrfs_csum_item *item;
5f39d397	78	struct extent_buffer *leaf;
6567e837	79	u64 csum_offset = 0;
a429e513	80	int csums_in_item;
6567e837 CM	81
	82	file_key.objectid = objectid;
	83	file_key.offset = offset;
6567e837	84	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
b18c6685	85	ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
6567e837 CM	86	if (ret < 0)
6567e837 CM	87	goto fail;
5f39d397	88	leaf = path->nodes[0];
6567e837 CM	89	if (ret > 0) {
6567e837 CM	90	ret = 1;
70b2befd	91	if (path->slots[0] == 0)
6567e837 CM	92	goto fail;
6567e837 CM	93	path->slots[0]--;
5f39d397	94	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6567e837 CM	95	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY \|\|
	96	found_key.objectid != objectid) {
	97	goto fail;
	98	}
	99	csum_offset = (offset - found_key.offset) >>
	100	root->fs_info->sb->s_blocksize_bits;
5f39d397	101	csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
509659cd	102	csums_in_item /= BTRFS_CRC32_SIZE;
a429e513 CM	103
	104	if (csum_offset >= csums_in_item) {
	105	ret = -EFBIG;
6567e837 CM	106	goto fail;
	107	}
	108	}
	109	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
509659cd CM	110	item = (struct btrfs_csum_item )((unsigned char )item +
509659cd CM	111	csum_offset * BTRFS_CRC32_SIZE);
6567e837 CM	112	return item;
	113	fail:
	114	if (ret > 0)
b18c6685	115	ret = -ENOENT;
6567e837 CM	116	return ERR_PTR(ret);
	117	}
	118
	119
dee26a9f CM	120	int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
	121	struct btrfs_root *root,
	122	struct btrfs_path *path, u64 objectid,
9773a788	123	u64 offset, int mod)
dee26a9f CM	124	{
	125	int ret;
	126	struct btrfs_key file_key;
	127	int ins_len = mod < 0 ? -1 : 0;
	128	int cow = mod != 0;
	129
	130	file_key.objectid = objectid;
70b2befd	131	file_key.offset = offset;
dee26a9f CM	132	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
	133	ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
	134	return ret;
	135	}
f254e52c	136
61b49440 CM	137	int btrfs_lookup_bio_sums(struct btrfs_root root, struct inode inode,
	138	struct bio *bio)
	139	{
	140	u32 sum;
	141	struct bio_vec *bvec = bio->bi_io_vec;
	142	int bio_index = 0;
	143	u64 offset;
	144	u64 item_start_offset = 0;
	145	u64 item_last_offset = 0;
	146	u32 diff;
	147	int ret;
	148	struct btrfs_path *path;
	149	struct btrfs_csum_item *item = NULL;
	150	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
	151
	152	path = btrfs_alloc_path();
61b49440 CM	153
	154	WARN_ON(bio->bi_vcnt <= 0);
	155
	156	while(bio_index < bio->bi_vcnt) {
	157	offset = page_offset(bvec->bv_page) + bvec->bv_offset;
	158	ret = btrfs_find_ordered_sum(inode, offset, &sum);
	159	if (ret == 0)
	160	goto found;
	161
	162	if (!item \|\| offset < item_start_offset \|\|
	163	offset >= item_last_offset) {
	164	struct btrfs_key found_key;
	165	u32 item_size;
	166
	167	if (item)
	168	btrfs_release_path(root, path);
	169	item = btrfs_lookup_csum(NULL, root, path,
	170	inode->i_ino, offset, 0);
	171	if (IS_ERR(item)) {
	172	ret = PTR_ERR(item);
	173	if (ret == -ENOENT \|\| ret == -EFBIG)
	174	ret = 0;
	175	sum = 0;
	176	printk("no csum found for inode %lu start "
	177	"%llu\n", inode->i_ino,
	178	(unsigned long long)offset);
6dab8157	179	item = NULL;
61b49440 CM	180	goto found;
	181	}
	182	btrfs_item_key_to_cpu(path->nodes[0], &found_key,
	183	path->slots[0]);
	184
	185	item_start_offset = found_key.offset;
	186	item_size = btrfs_item_size_nr(path->nodes[0],
	187	path->slots[0]);
	188	item_last_offset = item_start_offset +
	189	(item_size / BTRFS_CRC32_SIZE) *
	190	root->sectorsize;
	191	item = btrfs_item_ptr(path->nodes[0], path->slots[0],
	192	struct btrfs_csum_item);
	193	}
	194	/*
	195	* this byte range must be able to fit inside
	196	* a single leaf so it will also fit inside a u32
	197	*/
	198	diff = offset - item_start_offset;
	199	diff = diff / root->sectorsize;
	200	diff = diff * BTRFS_CRC32_SIZE;
	201
	202	read_extent_buffer(path->nodes[0], &sum,
	203	(unsigned long)item + diff,
	204	BTRFS_CRC32_SIZE);
	205	found:
	206	set_state_private(io_tree, offset, sum);
	207	bio_index++;
	208	bvec++;
	209	}
	210	btrfs_free_path(path);
	211	return 0;
	212	}
	213
3edf7d33 CM	214	int btrfs_csum_one_bio(struct btrfs_root root, struct inode inode,
3edf7d33 CM	215	struct bio *bio)
e015640f	216	{
e6dcd2dc CM	217	struct btrfs_ordered_sum *sums;
e6dcd2dc CM	218	struct btrfs_sector_sum *sector_sum;
3edf7d33	219	struct btrfs_ordered_extent *ordered;
e015640f CM	220	char *data;
	221	struct bio_vec *bvec = bio->bi_io_vec;
	222	int bio_index = 0;
3edf7d33 CM	223	unsigned long total_bytes = 0;
	224	unsigned long this_sum_bytes = 0;
	225	u64 offset;
e015640f	226
e6dcd2dc CM	227	WARN_ON(bio->bi_vcnt <= 0);
e6dcd2dc CM	228	sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
e015640f CM	229	if (!sums)
e015640f CM	230	return -ENOMEM;
3edf7d33	231
ed98b56a	232	sector_sum = sums->sums;
3edf7d33	233	sums->file_offset = page_offset(bvec->bv_page) + bvec->bv_offset;
e6dcd2dc CM	234	sums->len = bio->bi_size;
e6dcd2dc CM	235	INIT_LIST_HEAD(&sums->list);
3edf7d33 CM	236	ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
3edf7d33 CM	237	BUG_ON(!ordered);
e015640f CM	238
e015640f CM	239	while(bio_index < bio->bi_vcnt) {
3edf7d33	240	offset = page_offset(bvec->bv_page) + bvec->bv_offset;
e5a2217e CM	241	if (offset >= ordered->file_offset + ordered->len \|\|
e5a2217e CM	242	offset < ordered->file_offset) {
3edf7d33 CM	243	unsigned long bytes_left;
	244	sums->len = this_sum_bytes;
	245	this_sum_bytes = 0;
	246	btrfs_add_ordered_sum(inode, ordered, sums);
	247	btrfs_put_ordered_extent(ordered);
	248
	249	bytes_left = bio->bi_size - total_bytes;
	250
	251	sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
	252	GFP_NOFS);
	253	BUG_ON(!sums);
ed98b56a	254	sector_sum = sums->sums;
3edf7d33 CM	255	sums->len = bytes_left;
	256	sums->file_offset = offset;
	257	ordered = btrfs_lookup_ordered_extent(inode,
	258	sums->file_offset);
	259	BUG_ON(!ordered);
	260	}
	261
e015640f	262	data = kmap_atomic(bvec->bv_page, KM_USER0);
e6dcd2dc CM	263	sector_sum->sum = ~(u32)0;
	264	sector_sum->sum = btrfs_csum_data(root,
	265	data + bvec->bv_offset,
	266	sector_sum->sum,
	267	bvec->bv_len);
e015640f	268	kunmap_atomic(data, KM_USER0);
e6dcd2dc CM	269	btrfs_csum_final(sector_sum->sum,
	270	(char *)&sector_sum->sum);
	271	sector_sum->offset = page_offset(bvec->bv_page) +
	272	bvec->bv_offset;
ed98b56a	273
e6dcd2dc	274	sector_sum++;
e015640f	275	bio_index++;
3edf7d33 CM	276	total_bytes += bvec->bv_len;
3edf7d33 CM	277	this_sum_bytes += bvec->bv_len;
e015640f CM	278	bvec++;
e015640f CM	279	}
ed98b56a	280	this_sum_bytes = 0;
3edf7d33 CM	281	btrfs_add_ordered_sum(inode, ordered, sums);
3edf7d33 CM	282	btrfs_put_ordered_extent(ordered);
e015640f CM	283	return 0;
	284	}
	285
065631f6 CM	286	int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
065631f6 CM	287	struct btrfs_root root, struct inode inode,
e6dcd2dc	288	struct btrfs_ordered_sum *sums)
f254e52c	289	{
065631f6 CM	290	u64 objectid = inode->i_ino;
065631f6 CM	291	u64 offset;
f254e52c CM	292	int ret;
f254e52c CM	293	struct btrfs_key file_key;
6567e837	294	struct btrfs_key found_key;
065631f6	295	u64 next_offset;
e6dcd2dc	296	u64 total_bytes = 0;
065631f6	297	int found_next;
5caf2a00	298	struct btrfs_path *path;
f254e52c	299	struct btrfs_csum_item *item;
065631f6	300	struct btrfs_csum_item *item_end;
ff79f819	301	struct extent_buffer *leaf = NULL;
6567e837	302	u64 csum_offset;
e6dcd2dc	303	struct btrfs_sector_sum *sector_sum;
f578d4bd CM	304	u32 nritems;
f578d4bd CM	305	u32 ins_size;
6e92f5e6 CM	306	char *eb_map;
	307	char *eb_token;
	308	unsigned long map_len;
	309	unsigned long map_start;
	310
5caf2a00 CM	311	path = btrfs_alloc_path();
5caf2a00 CM	312	BUG_ON(!path);
ed98b56a	313	sector_sum = sums->sums;
065631f6 CM	314	again:
	315	next_offset = (u64)-1;
	316	found_next = 0;
e6dcd2dc	317	offset = sector_sum->offset;
f254e52c CM	318	file_key.objectid = objectid;
f254e52c CM	319	file_key.offset = offset;
f254e52c	320	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
a429e513 CM	321
a429e513 CM	322	item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
ff79f819 CM	323	if (!IS_ERR(item)) {
ff79f819 CM	324	leaf = path->nodes[0];
a429e513	325	goto found;
ff79f819	326	}
a429e513 CM	327	ret = PTR_ERR(item);
	328	if (ret == -EFBIG) {
	329	u32 item_size;
	330	/* we found one, but it isn't big enough yet */
5f39d397 CM	331	leaf = path->nodes[0];
5f39d397 CM	332	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
509659cd	333	if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
a429e513 CM	334	/* already at max size, make a new one */
	335	goto insert;
	336	}
	337	} else {
f578d4bd	338	int slot = path->slots[0] + 1;
a429e513	339	/* we didn't find a csum item, insert one */
f578d4bd CM	340	nritems = btrfs_header_nritems(path->nodes[0]);
	341	if (path->slots[0] >= nritems - 1) {
	342	ret = btrfs_next_leaf(root, path);
b56baf5b	343	if (ret == 1)
f578d4bd	344	found_next = 1;
b56baf5b	345	if (ret != 0)
f578d4bd	346	goto insert;
b56baf5b	347	slot = 0;
f578d4bd CM	348	}
	349	btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
	350	if (found_key.objectid != objectid \|\|
	351	found_key.type != BTRFS_CSUM_ITEM_KEY) {
	352	found_next = 1;
	353	goto insert;
	354	}
	355	next_offset = found_key.offset;
	356	found_next = 1;
a429e513 CM	357	goto insert;
	358	}
	359
	360	/*
	361	* at this point, we know the tree has an item, but it isn't big
	362	* enough yet to put our csum in. Grow it
	363	*/
	364	btrfs_release_path(root, path);
6567e837	365	ret = btrfs_search_slot(trans, root, &file_key, path,
509659cd	366	BTRFS_CRC32_SIZE, 1);
6567e837 CM	367	if (ret < 0)
	368	goto fail;
	369	if (ret == 0) {
b18c6685	370	BUG();
6567e837 CM	371	}
6567e837 CM	372	if (path->slots[0] == 0) {
6567e837 CM	373	goto insert;
	374	}
	375	path->slots[0]--;
5f39d397 CM	376	leaf = path->nodes[0];
5f39d397 CM	377	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6567e837 CM	378	csum_offset = (offset - found_key.offset) >>
	379	root->fs_info->sb->s_blocksize_bits;
	380	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY \|\|
	381	found_key.objectid != objectid \|\|
	382	csum_offset >= MAX_CSUM_ITEMS(root)) {
6567e837 CM	383	goto insert;
6567e837 CM	384	}
5f39d397	385	if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
509659cd CM	386	BTRFS_CRC32_SIZE) {
509659cd CM	387	u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
5f39d397	388	diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
3a686375 CM	389	if (diff != BTRFS_CRC32_SIZE)
3a686375 CM	390	goto insert;
a429e513	391	ret = btrfs_extend_item(trans, root, path, diff);
6567e837 CM	392	BUG_ON(ret);
	393	goto csum;
	394	}
	395
	396	insert:
a429e513	397	btrfs_release_path(root, path);
6567e837	398	csum_offset = 0;
f578d4bd CM	399	if (found_next) {
f578d4bd CM	400	u64 tmp = min((u64)i_size_read(inode), next_offset);
b56baf5b	401	tmp -= offset & ~((u64)root->sectorsize -1);
f578d4bd CM	402	tmp >>= root->fs_info->sb->s_blocksize_bits;
	403	tmp = max((u64)1, tmp);
	404	tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root));
	405	ins_size = BTRFS_CRC32_SIZE * tmp;
	406	} else {
	407	ins_size = BTRFS_CRC32_SIZE;
	408	}
5caf2a00	409	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
f578d4bd	410	ins_size);
54aa1f4d CM	411	if (ret < 0)
54aa1f4d CM	412	goto fail;
a429e513	413	if (ret != 0) {
a429e513	414	WARN_ON(1);
f254e52c	415	goto fail;
a429e513	416	}
6567e837	417	csum:
5f39d397 CM	418	leaf = path->nodes[0];
5f39d397 CM	419	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
f254e52c	420	ret = 0;
509659cd CM	421	item = (struct btrfs_csum_item )((unsigned char )item +
509659cd CM	422	csum_offset * BTRFS_CRC32_SIZE);
b18c6685	423	found:
065631f6 CM	424	item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
	425	item_end = (struct btrfs_csum_item )((unsigned char )item_end +
	426	btrfs_item_size_nr(leaf, path->slots[0]));
6e92f5e6	427	eb_token = NULL;
e6dcd2dc	428	next_sector:
aadfeb6e	429
6e92f5e6 CM	430	if (!eb_token \|\|
	431	(unsigned long)item + BTRFS_CRC32_SIZE >= map_start + map_len) {
	432	int err;
	433
	434	if (eb_token)
eb20978f	435	unmap_extent_buffer(leaf, eb_token, KM_USER1);
6e92f5e6 CM	436	eb_token = NULL;
	437	err = map_private_extent_buffer(leaf, (unsigned long)item,
	438	BTRFS_CRC32_SIZE,
	439	&eb_token, &eb_map,
eb20978f	440	&map_start, &map_len, KM_USER1);
6e92f5e6 CM	441	if (err)
	442	eb_token = NULL;
	443	}
	444	if (eb_token) {
	445	memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
e6dcd2dc	446	&sector_sum->sum, BTRFS_CRC32_SIZE);
6e92f5e6	447	} else {
e6dcd2dc CM	448	write_extent_buffer(leaf, &sector_sum->sum,
e6dcd2dc CM	449	(unsigned long)item, BTRFS_CRC32_SIZE);
6e92f5e6	450	}
7f3c74fb	451
e6dcd2dc CM	452	total_bytes += root->sectorsize;
	453	sector_sum++;
	454	if (total_bytes < sums->len) {
6e92f5e6 CM	455	item = (struct btrfs_csum_item )((char )item +
6e92f5e6 CM	456	BTRFS_CRC32_SIZE);
2e1a992e	457	if (item < item_end && offset + PAGE_CACHE_SIZE ==
e6dcd2dc CM	458	sector_sum->offset) {
	459	offset = sector_sum->offset;
	460	goto next_sector;
2e1a992e	461	}
065631f6	462	}
6e92f5e6	463	if (eb_token) {
eb20978f	464	unmap_extent_buffer(leaf, eb_token, KM_USER1);
6e92f5e6 CM	465	eb_token = NULL;
6e92f5e6 CM	466	}
5caf2a00	467	btrfs_mark_buffer_dirty(path->nodes[0]);
e6dcd2dc	468	if (total_bytes < sums->len) {
065631f6 CM	469	btrfs_release_path(root, path);
	470	goto again;
	471	}
f254e52c	472	fail:
5caf2a00	473	btrfs_free_path(path);
f254e52c CM	474	return ret;
	475	}
	476
1de037a4 CM	477	int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
	478	struct btrfs_root root, struct btrfs_path path,
	479	u64 isize)
	480	{
	481	struct btrfs_key key;
5f39d397	482	struct extent_buffer *leaf = path->nodes[0];
1de037a4 CM	483	int slot = path->slots[0];
	484	int ret;
	485	u32 new_item_size;
	486	u64 new_item_span;
	487	u64 blocks;
	488
5f39d397	489	btrfs_item_key_to_cpu(leaf, &key, slot);
1de037a4 CM	490	if (isize <= key.offset)
	491	return 0;
	492	new_item_span = isize - key.offset;
5f39d397	493	blocks = (new_item_span + root->sectorsize - 1) >>
84f54cfa	494	root->fs_info->sb->s_blocksize_bits;
1de037a4	495	new_item_size = blocks * BTRFS_CRC32_SIZE;
5f39d397	496	if (new_item_size >= btrfs_item_size_nr(leaf, slot))
1de037a4	497	return 0;
179e29e4	498	ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);
1de037a4 CM	499	BUG_ON(ret);
	500	return ret;
	501	}