[linux-2.6-block.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, u64 ram_bytes,
			     u8 compression, u8 encryption, u16 other_encoding)
{
	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_ram_bytes(leaf, item, ram_bytes);
	btrfs_set_file_extent_generation(leaf, item, trans->transid);
	btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
	btrfs_set_file_extent_compression(leaf, item, compression);
	btrfs_set_file_extent_encryption(leaf, item, encryption);
	btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);

	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();
	if (bio->bi_size > PAGE_CACHE_SIZE * 8)
		path->reada = 2;

	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_file_bytes(struct btrfs_root *root, struct inode *inode,
			  u64 start, unsigned long len)
{
	struct btrfs_ordered_sum *sums;
	struct btrfs_sector_sum *sector_sum;
	struct btrfs_ordered_extent *ordered;
	char *data;
	struct page *page;
	unsigned long total_bytes = 0;
	unsigned long this_sum_bytes = 0;

	sums = kzalloc(btrfs_ordered_sum_size(root, len), GFP_NOFS);
	if (!sums)
		return -ENOMEM;

	sector_sum = sums->sums;
	sums->file_offset = start;
	sums->len = len;
	INIT_LIST_HEAD(&sums->list);
	ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
	BUG_ON(!ordered);

	while(len > 0) {
		if (start >= ordered->file_offset + ordered->len ||
		    start < ordered->file_offset) {
			sums->len = this_sum_bytes;
			this_sum_bytes = 0;
			btrfs_add_ordered_sum(inode, ordered, sums);
			btrfs_put_ordered_extent(ordered);

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

		page = find_get_page(inode->i_mapping,
				     start >> PAGE_CACHE_SHIFT);

		data = kmap_atomic(page, KM_USER0);
		sector_sum->sum = ~(u32)0;
		sector_sum->sum = btrfs_csum_data(root, data, sector_sum->sum,
						  PAGE_CACHE_SIZE);
		kunmap_atomic(data, KM_USER0);
		btrfs_csum_final(sector_sum->sum,
				 (char *)&sector_sum->sum);
		sector_sum->offset = page_offset(page);
		page_cache_release(page);

		sector_sum++;
		total_bytes += PAGE_CACHE_SIZE;
		this_sum_bytes += PAGE_CACHE_SIZE;
		start += PAGE_CACHE_SIZE;

		WARN_ON(len < PAGE_CACHE_SIZE);
		len -= PAGE_CACHE_SIZE;
	}
	btrfs_add_ordered_sum(inode, ordered, sums);
	btrfs_put_ordered_extent(ordered);
	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);

	mutex_lock(&BTRFS_I(inode)->csum_mutex);
	item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
	if (!IS_ERR(item)) {
		leaf = path->nodes[0];
		ret = 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_unlock;
	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_unlock;
	if (ret != 0) {
		WARN_ON(1);
		goto fail_unlock;
	}
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;
	mutex_unlock(&BTRFS_I(inode)->csum_mutex);
	cond_resched();
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]);
	cond_resched();
	if (total_bytes < sums->len) {
		btrfs_release_path(root, path);
		goto again;
	}
out:
	btrfs_free_path(path);
	return ret;

fail_unlock:
	mutex_unlock(&BTRFS_I(inode)->csum_mutex);
	goto out;
}

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,
c8b97818 CM	34	u64 num_bytes, u64 offset, u64 ram_bytes,
c8b97818 CM	35	u8 compression, u8 encryption, u16 other_encoding)
9f5fae2f	36	{
dee26a9f CM	37	int ret = 0;
	38	struct btrfs_file_extent_item *item;
	39	struct btrfs_key file_key;
5caf2a00	40	struct btrfs_path *path;
5f39d397	41	struct extent_buffer *leaf;
dee26a9f	42
5caf2a00 CM	43	path = btrfs_alloc_path();
5caf2a00 CM	44	BUG_ON(!path);
dee26a9f	45	file_key.objectid = objectid;
b18c6685	46	file_key.offset = pos;
dee26a9f CM	47	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
dee26a9f CM	48
5caf2a00	49	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
dee26a9f	50	sizeof(*item));
54aa1f4d CM	51	if (ret < 0)
54aa1f4d CM	52	goto out;
9773a788	53	BUG_ON(ret);
5f39d397 CM	54	leaf = path->nodes[0];
5f39d397 CM	55	item = btrfs_item_ptr(leaf, path->slots[0],
dee26a9f	56	struct btrfs_file_extent_item);
f2eb0a24	57	btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
db94535d	58	btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
f2eb0a24	59	btrfs_set_file_extent_offset(leaf, item, offset);
db94535d	60	btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
c8b97818	61	btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
5f39d397 CM	62	btrfs_set_file_extent_generation(leaf, item, trans->transid);
5f39d397 CM	63	btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
c8b97818 CM	64	btrfs_set_file_extent_compression(leaf, item, compression);
	65	btrfs_set_file_extent_encryption(leaf, item, encryption);
	66	btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
	67
5f39d397	68	btrfs_mark_buffer_dirty(leaf);
54aa1f4d	69	out:
5caf2a00	70	btrfs_free_path(path);
54aa1f4d	71	return ret;
9f5fae2f	72	}
dee26a9f	73
b18c6685 CM	74	struct btrfs_csum_item btrfs_lookup_csum(struct btrfs_trans_handle trans,
	75	struct btrfs_root *root,
	76	struct btrfs_path *path,
	77	u64 objectid, u64 offset,
	78	int cow)
6567e837 CM	79	{
	80	int ret;
	81	struct btrfs_key file_key;
	82	struct btrfs_key found_key;
	83	struct btrfs_csum_item *item;
5f39d397	84	struct extent_buffer *leaf;
6567e837	85	u64 csum_offset = 0;
a429e513	86	int csums_in_item;
6567e837 CM	87
	88	file_key.objectid = objectid;
	89	file_key.offset = offset;
6567e837	90	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
b18c6685	91	ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
6567e837 CM	92	if (ret < 0)
6567e837 CM	93	goto fail;
5f39d397	94	leaf = path->nodes[0];
6567e837 CM	95	if (ret > 0) {
6567e837 CM	96	ret = 1;
70b2befd	97	if (path->slots[0] == 0)
6567e837 CM	98	goto fail;
6567e837 CM	99	path->slots[0]--;
5f39d397	100	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6567e837 CM	101	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY \|\|
	102	found_key.objectid != objectid) {
	103	goto fail;
	104	}
	105	csum_offset = (offset - found_key.offset) >>
	106	root->fs_info->sb->s_blocksize_bits;
5f39d397	107	csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
509659cd	108	csums_in_item /= BTRFS_CRC32_SIZE;
a429e513 CM	109
	110	if (csum_offset >= csums_in_item) {
	111	ret = -EFBIG;
6567e837 CM	112	goto fail;
	113	}
	114	}
	115	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
509659cd CM	116	item = (struct btrfs_csum_item )((unsigned char )item +
509659cd CM	117	csum_offset * BTRFS_CRC32_SIZE);
6567e837 CM	118	return item;
	119	fail:
	120	if (ret > 0)
b18c6685	121	ret = -ENOENT;
6567e837 CM	122	return ERR_PTR(ret);
	123	}
	124
	125
dee26a9f CM	126	int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
	127	struct btrfs_root *root,
	128	struct btrfs_path *path, u64 objectid,
9773a788	129	u64 offset, int mod)
dee26a9f CM	130	{
	131	int ret;
	132	struct btrfs_key file_key;
	133	int ins_len = mod < 0 ? -1 : 0;
	134	int cow = mod != 0;
	135
	136	file_key.objectid = objectid;
70b2befd	137	file_key.offset = offset;
dee26a9f CM	138	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
	139	ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
	140	return ret;
	141	}
f254e52c	142
61b49440 CM	143	int btrfs_lookup_bio_sums(struct btrfs_root root, struct inode inode,
	144	struct bio *bio)
	145	{
	146	u32 sum;
	147	struct bio_vec *bvec = bio->bi_io_vec;
	148	int bio_index = 0;
	149	u64 offset;
	150	u64 item_start_offset = 0;
	151	u64 item_last_offset = 0;
	152	u32 diff;
	153	int ret;
	154	struct btrfs_path *path;
	155	struct btrfs_csum_item *item = NULL;
	156	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
	157
	158	path = btrfs_alloc_path();
4d1b5fb4 CM	159	if (bio->bi_size > PAGE_CACHE_SIZE * 8)
4d1b5fb4 CM	160	path->reada = 2;
61b49440 CM	161
	162	WARN_ON(bio->bi_vcnt <= 0);
	163
	164	while(bio_index < bio->bi_vcnt) {
	165	offset = page_offset(bvec->bv_page) + bvec->bv_offset;
	166	ret = btrfs_find_ordered_sum(inode, offset, &sum);
	167	if (ret == 0)
	168	goto found;
	169
	170	if (!item \|\| offset < item_start_offset \|\|
	171	offset >= item_last_offset) {
	172	struct btrfs_key found_key;
	173	u32 item_size;
	174
	175	if (item)
	176	btrfs_release_path(root, path);
	177	item = btrfs_lookup_csum(NULL, root, path,
	178	inode->i_ino, offset, 0);
	179	if (IS_ERR(item)) {
	180	ret = PTR_ERR(item);
	181	if (ret == -ENOENT \|\| ret == -EFBIG)
	182	ret = 0;
	183	sum = 0;
	184	printk("no csum found for inode %lu start "
	185	"%llu\n", inode->i_ino,
	186	(unsigned long long)offset);
6dab8157	187	item = NULL;
61b49440 CM	188	goto found;
	189	}
	190	btrfs_item_key_to_cpu(path->nodes[0], &found_key,
	191	path->slots[0]);
	192
	193	item_start_offset = found_key.offset;
	194	item_size = btrfs_item_size_nr(path->nodes[0],
	195	path->slots[0]);
	196	item_last_offset = item_start_offset +
	197	(item_size / BTRFS_CRC32_SIZE) *
	198	root->sectorsize;
	199	item = btrfs_item_ptr(path->nodes[0], path->slots[0],
	200	struct btrfs_csum_item);
	201	}
	202	/*
	203	* this byte range must be able to fit inside
	204	* a single leaf so it will also fit inside a u32
	205	*/
	206	diff = offset - item_start_offset;
	207	diff = diff / root->sectorsize;
	208	diff = diff * BTRFS_CRC32_SIZE;
	209
	210	read_extent_buffer(path->nodes[0], &sum,
3de9d6b6	211	((unsigned long)item) + diff,
61b49440 CM	212	BTRFS_CRC32_SIZE);
	213	found:
	214	set_state_private(io_tree, offset, sum);
	215	bio_index++;
	216	bvec++;
	217	}
	218	btrfs_free_path(path);
	219	return 0;
	220	}
	221
c8b97818 CM	222	int btrfs_csum_file_bytes(struct btrfs_root root, struct inode inode,
	223	u64 start, unsigned long len)
	224	{
	225	struct btrfs_ordered_sum *sums;
	226	struct btrfs_sector_sum *sector_sum;
	227	struct btrfs_ordered_extent *ordered;
	228	char *data;
	229	struct page *page;
	230	unsigned long total_bytes = 0;
	231	unsigned long this_sum_bytes = 0;
	232
	233	sums = kzalloc(btrfs_ordered_sum_size(root, len), GFP_NOFS);
	234	if (!sums)
	235	return -ENOMEM;
	236
	237	sector_sum = sums->sums;
	238	sums->file_offset = start;
	239	sums->len = len;
	240	INIT_LIST_HEAD(&sums->list);
	241	ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
	242	BUG_ON(!ordered);
	243
	244	while(len > 0) {
	245	if (start >= ordered->file_offset + ordered->len \|\|
	246	start < ordered->file_offset) {
	247	sums->len = this_sum_bytes;
	248	this_sum_bytes = 0;
	249	btrfs_add_ordered_sum(inode, ordered, sums);
	250	btrfs_put_ordered_extent(ordered);
	251
	252	sums = kzalloc(btrfs_ordered_sum_size(root, len),
	253	GFP_NOFS);
	254	BUG_ON(!sums);
	255	sector_sum = sums->sums;
	256	sums->len = len;
	257	sums->file_offset = start;
	258	ordered = btrfs_lookup_ordered_extent(inode,
	259	sums->file_offset);
	260	BUG_ON(!ordered);
	261	}
	262
	263	page = find_get_page(inode->i_mapping,
	264	start >> PAGE_CACHE_SHIFT);
	265
	266	data = kmap_atomic(page, KM_USER0);
	267	sector_sum->sum = ~(u32)0;
	268	sector_sum->sum = btrfs_csum_data(root, data, sector_sum->sum,
	269	PAGE_CACHE_SIZE);
	270	kunmap_atomic(data, KM_USER0);
	271	btrfs_csum_final(sector_sum->sum,
	272	(char *)&sector_sum->sum);
	273	sector_sum->offset = page_offset(page);
	274	page_cache_release(page);
	275
	276	sector_sum++;
	277	total_bytes += PAGE_CACHE_SIZE;
	278	this_sum_bytes += PAGE_CACHE_SIZE;
	279	start += PAGE_CACHE_SIZE;
	280
	281	WARN_ON(len < PAGE_CACHE_SIZE);
	282	len -= PAGE_CACHE_SIZE;
	283	}
	284	btrfs_add_ordered_sum(inode, ordered, sums);
	285	btrfs_put_ordered_extent(ordered);
286	return 0;
287	}
288
3edf7d33 CM	289	int btrfs_csum_one_bio(struct btrfs_root root, struct inode inode,
3edf7d33 CM	290	struct bio *bio)
e015640f	291	{
e6dcd2dc CM	292	struct btrfs_ordered_sum *sums;
e6dcd2dc CM	293	struct btrfs_sector_sum *sector_sum;
3edf7d33	294	struct btrfs_ordered_extent *ordered;
e015640f CM	295	char *data;
	296	struct bio_vec *bvec = bio->bi_io_vec;
	297	int bio_index = 0;
3edf7d33 CM	298	unsigned long total_bytes = 0;
	299	unsigned long this_sum_bytes = 0;
	300	u64 offset;
e015640f	301
e6dcd2dc CM	302	WARN_ON(bio->bi_vcnt <= 0);
e6dcd2dc CM	303	sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
e015640f CM	304	if (!sums)
e015640f CM	305	return -ENOMEM;
3edf7d33	306
ed98b56a	307	sector_sum = sums->sums;
3edf7d33	308	sums->file_offset = page_offset(bvec->bv_page) + bvec->bv_offset;
e6dcd2dc CM	309	sums->len = bio->bi_size;
e6dcd2dc CM	310	INIT_LIST_HEAD(&sums->list);
3edf7d33 CM	311	ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
3edf7d33 CM	312	BUG_ON(!ordered);
e015640f CM	313
e015640f CM	314	while(bio_index < bio->bi_vcnt) {
3edf7d33	315	offset = page_offset(bvec->bv_page) + bvec->bv_offset;
e5a2217e CM	316	if (offset >= ordered->file_offset + ordered->len \|\|
e5a2217e CM	317	offset < ordered->file_offset) {
3edf7d33 CM	318	unsigned long bytes_left;
	319	sums->len = this_sum_bytes;
	320	this_sum_bytes = 0;
	321	btrfs_add_ordered_sum(inode, ordered, sums);
	322	btrfs_put_ordered_extent(ordered);
	323
	324	bytes_left = bio->bi_size - total_bytes;
	325
	326	sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
	327	GFP_NOFS);
	328	BUG_ON(!sums);
ed98b56a	329	sector_sum = sums->sums;
3edf7d33 CM	330	sums->len = bytes_left;
	331	sums->file_offset = offset;
	332	ordered = btrfs_lookup_ordered_extent(inode,
	333	sums->file_offset);
	334	BUG_ON(!ordered);
	335	}
	336
e015640f	337	data = kmap_atomic(bvec->bv_page, KM_USER0);
e6dcd2dc CM	338	sector_sum->sum = ~(u32)0;
	339	sector_sum->sum = btrfs_csum_data(root,
	340	data + bvec->bv_offset,
	341	sector_sum->sum,
	342	bvec->bv_len);
e015640f	343	kunmap_atomic(data, KM_USER0);
e6dcd2dc CM	344	btrfs_csum_final(sector_sum->sum,
	345	(char *)&sector_sum->sum);
	346	sector_sum->offset = page_offset(bvec->bv_page) +
	347	bvec->bv_offset;
ed98b56a	348
e6dcd2dc	349	sector_sum++;
e015640f	350	bio_index++;
3edf7d33 CM	351	total_bytes += bvec->bv_len;
3edf7d33 CM	352	this_sum_bytes += bvec->bv_len;
e015640f CM	353	bvec++;
e015640f CM	354	}
ed98b56a	355	this_sum_bytes = 0;
3edf7d33 CM	356	btrfs_add_ordered_sum(inode, ordered, sums);
3edf7d33 CM	357	btrfs_put_ordered_extent(ordered);
e015640f CM	358	return 0;
	359	}
	360
065631f6 CM	361	int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
065631f6 CM	362	struct btrfs_root root, struct inode inode,
e6dcd2dc	363	struct btrfs_ordered_sum *sums)
f254e52c	364	{
065631f6 CM	365	u64 objectid = inode->i_ino;
065631f6 CM	366	u64 offset;
f254e52c CM	367	int ret;
f254e52c CM	368	struct btrfs_key file_key;
6567e837	369	struct btrfs_key found_key;
065631f6	370	u64 next_offset;
e6dcd2dc	371	u64 total_bytes = 0;
065631f6	372	int found_next;
5caf2a00	373	struct btrfs_path *path;
f254e52c	374	struct btrfs_csum_item *item;
065631f6	375	struct btrfs_csum_item *item_end;
ff79f819	376	struct extent_buffer *leaf = NULL;
6567e837	377	u64 csum_offset;
e6dcd2dc	378	struct btrfs_sector_sum *sector_sum;
f578d4bd CM	379	u32 nritems;
f578d4bd CM	380	u32 ins_size;
6e92f5e6 CM	381	char *eb_map;
	382	char *eb_token;
	383	unsigned long map_len;
	384	unsigned long map_start;
	385
5caf2a00 CM	386	path = btrfs_alloc_path();
5caf2a00 CM	387	BUG_ON(!path);
ed98b56a	388	sector_sum = sums->sums;
065631f6 CM	389	again:
	390	next_offset = (u64)-1;
	391	found_next = 0;
e6dcd2dc	392	offset = sector_sum->offset;
f254e52c CM	393	file_key.objectid = objectid;
f254e52c CM	394	file_key.offset = offset;
f254e52c	395	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
a429e513	396
53863232	397	mutex_lock(&BTRFS_I(inode)->csum_mutex);
a429e513	398	item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
ff79f819 CM	399	if (!IS_ERR(item)) {
ff79f819 CM	400	leaf = path->nodes[0];
639cb586	401	ret = 0;
a429e513	402	goto found;
ff79f819	403	}
a429e513 CM	404	ret = PTR_ERR(item);
	405	if (ret == -EFBIG) {
	406	u32 item_size;
	407	/* we found one, but it isn't big enough yet */
5f39d397 CM	408	leaf = path->nodes[0];
5f39d397 CM	409	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
509659cd	410	if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
a429e513 CM	411	/* already at max size, make a new one */
	412	goto insert;
	413	}
	414	} else {
f578d4bd	415	int slot = path->slots[0] + 1;
a429e513	416	/* we didn't find a csum item, insert one */
f578d4bd CM	417	nritems = btrfs_header_nritems(path->nodes[0]);
	418	if (path->slots[0] >= nritems - 1) {
	419	ret = btrfs_next_leaf(root, path);
b56baf5b	420	if (ret == 1)
f578d4bd	421	found_next = 1;
b56baf5b	422	if (ret != 0)
f578d4bd	423	goto insert;
b56baf5b	424	slot = 0;
f578d4bd CM	425	}
	426	btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
	427	if (found_key.objectid != objectid \|\|
	428	found_key.type != BTRFS_CSUM_ITEM_KEY) {
	429	found_next = 1;
	430	goto insert;
	431	}
	432	next_offset = found_key.offset;
	433	found_next = 1;
a429e513 CM	434	goto insert;
	435	}
	436
	437	/*
	438	* at this point, we know the tree has an item, but it isn't big
	439	* enough yet to put our csum in. Grow it
	440	*/
	441	btrfs_release_path(root, path);
6567e837	442	ret = btrfs_search_slot(trans, root, &file_key, path,
509659cd	443	BTRFS_CRC32_SIZE, 1);
6567e837	444	if (ret < 0)
53863232	445	goto fail_unlock;
6567e837	446	if (ret == 0) {
b18c6685	447	BUG();
6567e837 CM	448	}
6567e837 CM	449	if (path->slots[0] == 0) {
6567e837 CM	450	goto insert;
	451	}
	452	path->slots[0]--;
5f39d397 CM	453	leaf = path->nodes[0];
5f39d397 CM	454	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6567e837 CM	455	csum_offset = (offset - found_key.offset) >>
	456	root->fs_info->sb->s_blocksize_bits;
	457	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY \|\|
	458	found_key.objectid != objectid \|\|
	459	csum_offset >= MAX_CSUM_ITEMS(root)) {
6567e837 CM	460	goto insert;
6567e837 CM	461	}
5f39d397	462	if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
509659cd CM	463	BTRFS_CRC32_SIZE) {
509659cd CM	464	u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
5f39d397	465	diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
3a686375 CM	466	if (diff != BTRFS_CRC32_SIZE)
3a686375 CM	467	goto insert;
a429e513	468	ret = btrfs_extend_item(trans, root, path, diff);
6567e837 CM	469	BUG_ON(ret);
	470	goto csum;
	471	}
	472
	473	insert:
a429e513	474	btrfs_release_path(root, path);
6567e837	475	csum_offset = 0;
f578d4bd CM	476	if (found_next) {
f578d4bd CM	477	u64 tmp = min((u64)i_size_read(inode), next_offset);
b56baf5b	478	tmp -= offset & ~((u64)root->sectorsize -1);
f578d4bd CM	479	tmp >>= root->fs_info->sb->s_blocksize_bits;
	480	tmp = max((u64)1, tmp);
	481	tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root));
	482	ins_size = BTRFS_CRC32_SIZE * tmp;
	483	} else {
	484	ins_size = BTRFS_CRC32_SIZE;
	485	}
5caf2a00	486	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
f578d4bd	487	ins_size);
54aa1f4d	488	if (ret < 0)
53863232	489	goto fail_unlock;
a429e513	490	if (ret != 0) {
a429e513	491	WARN_ON(1);
53863232	492	goto fail_unlock;
a429e513	493	}
6567e837	494	csum:
5f39d397 CM	495	leaf = path->nodes[0];
5f39d397 CM	496	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
f254e52c	497	ret = 0;
509659cd CM	498	item = (struct btrfs_csum_item )((unsigned char )item +
509659cd CM	499	csum_offset * BTRFS_CRC32_SIZE);
b18c6685	500	found:
065631f6 CM	501	item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
	502	item_end = (struct btrfs_csum_item )((unsigned char )item_end +
	503	btrfs_item_size_nr(leaf, path->slots[0]));
6e92f5e6	504	eb_token = NULL;
53863232 CM	505	mutex_unlock(&BTRFS_I(inode)->csum_mutex);
53863232 CM	506	cond_resched();
e6dcd2dc	507	next_sector:
aadfeb6e	508
6e92f5e6 CM	509	if (!eb_token \|\|
	510	(unsigned long)item + BTRFS_CRC32_SIZE >= map_start + map_len) {
	511	int err;
	512
	513	if (eb_token)
eb20978f	514	unmap_extent_buffer(leaf, eb_token, KM_USER1);
6e92f5e6 CM	515	eb_token = NULL;
	516	err = map_private_extent_buffer(leaf, (unsigned long)item,
	517	BTRFS_CRC32_SIZE,
	518	&eb_token, &eb_map,
eb20978f	519	&map_start, &map_len, KM_USER1);
6e92f5e6 CM	520	if (err)
	521	eb_token = NULL;
	522	}
	523	if (eb_token) {
	524	memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
e6dcd2dc	525	&sector_sum->sum, BTRFS_CRC32_SIZE);
6e92f5e6	526	} else {
e6dcd2dc CM	527	write_extent_buffer(leaf, &sector_sum->sum,
e6dcd2dc CM	528	(unsigned long)item, BTRFS_CRC32_SIZE);
6e92f5e6	529	}
7f3c74fb	530
e6dcd2dc CM	531	total_bytes += root->sectorsize;
	532	sector_sum++;
	533	if (total_bytes < sums->len) {
6e92f5e6 CM	534	item = (struct btrfs_csum_item )((char )item +
6e92f5e6 CM	535	BTRFS_CRC32_SIZE);
2e1a992e	536	if (item < item_end && offset + PAGE_CACHE_SIZE ==
e6dcd2dc CM	537	sector_sum->offset) {
	538	offset = sector_sum->offset;
	539	goto next_sector;
2e1a992e	540	}
065631f6	541	}
6e92f5e6	542	if (eb_token) {
eb20978f	543	unmap_extent_buffer(leaf, eb_token, KM_USER1);
6e92f5e6 CM	544	eb_token = NULL;
6e92f5e6 CM	545	}
5caf2a00	546	btrfs_mark_buffer_dirty(path->nodes[0]);
53863232	547	cond_resched();
e6dcd2dc	548	if (total_bytes < sums->len) {
065631f6 CM	549	btrfs_release_path(root, path);
	550	goto again;
	551	}
53863232	552	out:
5caf2a00	553	btrfs_free_path(path);
f254e52c	554	return ret;
53863232 CM	555
	556	fail_unlock:
	557	mutex_unlock(&BTRFS_I(inode)->csum_mutex);
	558	goto out;
f254e52c CM	559	}
f254e52c CM	560
1de037a4 CM	561	int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
	562	struct btrfs_root root, struct btrfs_path path,
	563	u64 isize)
	564	{
	565	struct btrfs_key key;
5f39d397	566	struct extent_buffer *leaf = path->nodes[0];
1de037a4 CM	567	int slot = path->slots[0];
	568	int ret;
	569	u32 new_item_size;
	570	u64 new_item_span;
	571	u64 blocks;
	572
5f39d397	573	btrfs_item_key_to_cpu(leaf, &key, slot);
1de037a4 CM	574	if (isize <= key.offset)
	575	return 0;
	576	new_item_span = isize - key.offset;
5f39d397	577	blocks = (new_item_span + root->sectorsize - 1) >>
84f54cfa	578	root->fs_info->sb->s_blocksize_bits;
1de037a4	579	new_item_size = blocks * BTRFS_CRC32_SIZE;
5f39d397	580	if (new_item_size >= btrfs_item_size_nr(leaf, slot))
1de037a4	581	return 0;
179e29e4	582	ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);
1de037a4 CM	583	BUG_ON(ret);
	584	return ret;
	585	}