[GitHub/mt8127/android_kernel_alcatel_ttab.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,size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
				   sizeof(struct btrfs_item) * 2) / \
				  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;
	u16 csum_size =
		btrfs_super_csum_size(&root->fs_info->super_copy);
	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 /= csum_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 * csum_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;
	u16 csum_size =
		btrfs_super_csum_size(&root->fs_info->super_copy);
	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;
				btrfs_release_path(root, path);
				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 / csum_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 * csum_size;

		read_extent_buffer(path->nodes[0], &sum,
				   ((unsigned long)item) + diff,
				   csum_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;
	u16 csum_size =
		btrfs_super_csum_size(&root->fs_info->super_copy);

	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 / csum_size) >=
		    MAX_CSUM_ITEMS(root, csum_size)) {
			/* 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,
				csum_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, csum_size)) {
		goto insert;
	}
	if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
	    csum_size) {
		u32 diff = (csum_offset + 1) * csum_size;
		diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
		if (diff != csum_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, csum_size));
		ins_size = csum_size * tmp;
	} else {
		ins_size = csum_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 * csum_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 + csum_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,
						csum_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, csum_size);
	} else {
		write_extent_buffer(leaf, &sector_sum->sum,
				    (unsigned long)item, csum_size);
	}

	total_bytes += root->sectorsize;
	sector_sum++;
	if (total_bytes < sums->len) {
		item = (struct btrfs_csum_item *)((char *)item +
						  csum_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_super_csum_size(&root->fs_info->super_copy);
	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
607d432d JB	27	#define MAX_CSUM_ITEMS(r,size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
	28	sizeof(struct btrfs_item) * 2) / \
	29	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;
607d432d JB	86	u16 csum_size =
607d432d JB	87	btrfs_super_csum_size(&root->fs_info->super_copy);
a429e513	88	int csums_in_item;
6567e837 CM	89
	90	file_key.objectid = objectid;
	91	file_key.offset = offset;
6567e837	92	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
b18c6685	93	ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
6567e837 CM	94	if (ret < 0)
6567e837 CM	95	goto fail;
5f39d397	96	leaf = path->nodes[0];
6567e837 CM	97	if (ret > 0) {
6567e837 CM	98	ret = 1;
70b2befd	99	if (path->slots[0] == 0)
6567e837 CM	100	goto fail;
6567e837 CM	101	path->slots[0]--;
5f39d397	102	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6567e837 CM	103	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY \|\|
	104	found_key.objectid != objectid) {
	105	goto fail;
	106	}
	107	csum_offset = (offset - found_key.offset) >>
	108	root->fs_info->sb->s_blocksize_bits;
5f39d397	109	csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
607d432d	110	csums_in_item /= csum_size;
a429e513 CM	111
	112	if (csum_offset >= csums_in_item) {
	113	ret = -EFBIG;
6567e837 CM	114	goto fail;
	115	}
	116	}
	117	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
509659cd	118	item = (struct btrfs_csum_item )((unsigned char )item +
607d432d	119	csum_offset * csum_size);
6567e837 CM	120	return item;
	121	fail:
	122	if (ret > 0)
b18c6685	123	ret = -ENOENT;
6567e837 CM	124	return ERR_PTR(ret);
	125	}
	126
	127
dee26a9f CM	128	int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
	129	struct btrfs_root *root,
	130	struct btrfs_path *path, u64 objectid,
9773a788	131	u64 offset, int mod)
dee26a9f CM	132	{
	133	int ret;
	134	struct btrfs_key file_key;
	135	int ins_len = mod < 0 ? -1 : 0;
	136	int cow = mod != 0;
	137
	138	file_key.objectid = objectid;
70b2befd	139	file_key.offset = offset;
dee26a9f CM	140	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
	141	ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
	142	return ret;
	143	}
f254e52c	144
61b49440 CM	145	int btrfs_lookup_bio_sums(struct btrfs_root root, struct inode inode,
	146	struct bio *bio)
	147	{
	148	u32 sum;
	149	struct bio_vec *bvec = bio->bi_io_vec;
	150	int bio_index = 0;
	151	u64 offset;
	152	u64 item_start_offset = 0;
	153	u64 item_last_offset = 0;
	154	u32 diff;
607d432d JB	155	u16 csum_size =
607d432d JB	156	btrfs_super_csum_size(&root->fs_info->super_copy);
61b49440 CM	157	int ret;
	158	struct btrfs_path *path;
	159	struct btrfs_csum_item *item = NULL;
	160	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
	161
	162	path = btrfs_alloc_path();
4d1b5fb4 CM	163	if (bio->bi_size > PAGE_CACHE_SIZE * 8)
4d1b5fb4 CM	164	path->reada = 2;
61b49440 CM	165
	166	WARN_ON(bio->bi_vcnt <= 0);
	167
	168	while(bio_index < bio->bi_vcnt) {
	169	offset = page_offset(bvec->bv_page) + bvec->bv_offset;
	170	ret = btrfs_find_ordered_sum(inode, offset, &sum);
	171	if (ret == 0)
	172	goto found;
	173
	174	if (!item \|\| offset < item_start_offset \|\|
	175	offset >= item_last_offset) {
	176	struct btrfs_key found_key;
	177	u32 item_size;
	178
	179	if (item)
	180	btrfs_release_path(root, path);
	181	item = btrfs_lookup_csum(NULL, root, path,
	182	inode->i_ino, offset, 0);
	183	if (IS_ERR(item)) {
	184	ret = PTR_ERR(item);
	185	if (ret == -ENOENT \|\| ret == -EFBIG)
	186	ret = 0;
	187	sum = 0;
	188	printk("no csum found for inode %lu start "
	189	"%llu\n", inode->i_ino,
	190	(unsigned long long)offset);
6dab8157	191	item = NULL;
39be25cd	192	btrfs_release_path(root, path);
61b49440 CM	193	goto found;
	194	}
	195	btrfs_item_key_to_cpu(path->nodes[0], &found_key,
	196	path->slots[0]);
	197
	198	item_start_offset = found_key.offset;
	199	item_size = btrfs_item_size_nr(path->nodes[0],
	200	path->slots[0]);
	201	item_last_offset = item_start_offset +
607d432d	202	(item_size / csum_size) *
61b49440 CM	203	root->sectorsize;
	204	item = btrfs_item_ptr(path->nodes[0], path->slots[0],
	205	struct btrfs_csum_item);
	206	}
	207	/*
	208	* this byte range must be able to fit inside
	209	* a single leaf so it will also fit inside a u32
	210	*/
	211	diff = offset - item_start_offset;
	212	diff = diff / root->sectorsize;
607d432d	213	diff = diff * csum_size;
61b49440 CM	214
61b49440 CM	215	read_extent_buffer(path->nodes[0], &sum,
3de9d6b6	216	((unsigned long)item) + diff,
607d432d	217	csum_size);
61b49440 CM	218	found:
	219	set_state_private(io_tree, offset, sum);
	220	bio_index++;
	221	bvec++;
	222	}
	223	btrfs_free_path(path);
	224	return 0;
	225	}
	226
c8b97818 CM	227	int btrfs_csum_file_bytes(struct btrfs_root root, struct inode inode,
	228	u64 start, unsigned long len)
	229	{
	230	struct btrfs_ordered_sum *sums;
	231	struct btrfs_sector_sum *sector_sum;
	232	struct btrfs_ordered_extent *ordered;
	233	char *data;
	234	struct page *page;
	235	unsigned long total_bytes = 0;
	236	unsigned long this_sum_bytes = 0;
	237
	238	sums = kzalloc(btrfs_ordered_sum_size(root, len), GFP_NOFS);
	239	if (!sums)
	240	return -ENOMEM;
	241
	242	sector_sum = sums->sums;
	243	sums->file_offset = start;
	244	sums->len = len;
	245	INIT_LIST_HEAD(&sums->list);
	246	ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
	247	BUG_ON(!ordered);
	248
	249	while(len > 0) {
	250	if (start >= ordered->file_offset + ordered->len \|\|
	251	start < ordered->file_offset) {
	252	sums->len = this_sum_bytes;
	253	this_sum_bytes = 0;
	254	btrfs_add_ordered_sum(inode, ordered, sums);
	255	btrfs_put_ordered_extent(ordered);
	256
	257	sums = kzalloc(btrfs_ordered_sum_size(root, len),
	258	GFP_NOFS);
	259	BUG_ON(!sums);
	260	sector_sum = sums->sums;
	261	sums->len = len;
	262	sums->file_offset = start;
	263	ordered = btrfs_lookup_ordered_extent(inode,
	264	sums->file_offset);
	265	BUG_ON(!ordered);
	266	}
	267
	268	page = find_get_page(inode->i_mapping,
	269	start >> PAGE_CACHE_SHIFT);
	270
	271	data = kmap_atomic(page, KM_USER0);
	272	sector_sum->sum = ~(u32)0;
	273	sector_sum->sum = btrfs_csum_data(root, data, sector_sum->sum,
	274	PAGE_CACHE_SIZE);
	275	kunmap_atomic(data, KM_USER0);
	276	btrfs_csum_final(sector_sum->sum,
	277	(char *)&sector_sum->sum);
	278	sector_sum->offset = page_offset(page);
	279	page_cache_release(page);
	280
	281	sector_sum++;
	282	total_bytes += PAGE_CACHE_SIZE;
	283	this_sum_bytes += PAGE_CACHE_SIZE;
	284	start += PAGE_CACHE_SIZE;
	285
	286	WARN_ON(len < PAGE_CACHE_SIZE);
	287	len -= PAGE_CACHE_SIZE;
	288	}
	289	btrfs_add_ordered_sum(inode, ordered, sums);
	290	btrfs_put_ordered_extent(ordered);
291	return 0;
292	}
293
3edf7d33 CM	294	int btrfs_csum_one_bio(struct btrfs_root root, struct inode inode,
3edf7d33 CM	295	struct bio *bio)
e015640f	296	{
e6dcd2dc CM	297	struct btrfs_ordered_sum *sums;
e6dcd2dc CM	298	struct btrfs_sector_sum *sector_sum;
3edf7d33	299	struct btrfs_ordered_extent *ordered;
e015640f CM	300	char *data;
	301	struct bio_vec *bvec = bio->bi_io_vec;
	302	int bio_index = 0;
3edf7d33 CM	303	unsigned long total_bytes = 0;
	304	unsigned long this_sum_bytes = 0;
	305	u64 offset;
e015640f	306
e6dcd2dc CM	307	WARN_ON(bio->bi_vcnt <= 0);
e6dcd2dc CM	308	sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
e015640f CM	309	if (!sums)
e015640f CM	310	return -ENOMEM;
3edf7d33	311
ed98b56a	312	sector_sum = sums->sums;
3edf7d33	313	sums->file_offset = page_offset(bvec->bv_page) + bvec->bv_offset;
e6dcd2dc CM	314	sums->len = bio->bi_size;
e6dcd2dc CM	315	INIT_LIST_HEAD(&sums->list);
3edf7d33 CM	316	ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
3edf7d33 CM	317	BUG_ON(!ordered);
e015640f CM	318
e015640f CM	319	while(bio_index < bio->bi_vcnt) {
3edf7d33	320	offset = page_offset(bvec->bv_page) + bvec->bv_offset;
e5a2217e CM	321	if (offset >= ordered->file_offset + ordered->len \|\|
e5a2217e CM	322	offset < ordered->file_offset) {
3edf7d33 CM	323	unsigned long bytes_left;
	324	sums->len = this_sum_bytes;
	325	this_sum_bytes = 0;
	326	btrfs_add_ordered_sum(inode, ordered, sums);
	327	btrfs_put_ordered_extent(ordered);
	328
	329	bytes_left = bio->bi_size - total_bytes;
	330
	331	sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
	332	GFP_NOFS);
	333	BUG_ON(!sums);
ed98b56a	334	sector_sum = sums->sums;
3edf7d33 CM	335	sums->len = bytes_left;
	336	sums->file_offset = offset;
	337	ordered = btrfs_lookup_ordered_extent(inode,
	338	sums->file_offset);
	339	BUG_ON(!ordered);
	340	}
	341
e015640f	342	data = kmap_atomic(bvec->bv_page, KM_USER0);
e6dcd2dc CM	343	sector_sum->sum = ~(u32)0;
	344	sector_sum->sum = btrfs_csum_data(root,
	345	data + bvec->bv_offset,
	346	sector_sum->sum,
	347	bvec->bv_len);
e015640f	348	kunmap_atomic(data, KM_USER0);
e6dcd2dc CM	349	btrfs_csum_final(sector_sum->sum,
	350	(char *)&sector_sum->sum);
	351	sector_sum->offset = page_offset(bvec->bv_page) +
	352	bvec->bv_offset;
ed98b56a	353
e6dcd2dc	354	sector_sum++;
e015640f	355	bio_index++;
3edf7d33 CM	356	total_bytes += bvec->bv_len;
3edf7d33 CM	357	this_sum_bytes += bvec->bv_len;
e015640f CM	358	bvec++;
e015640f CM	359	}
ed98b56a	360	this_sum_bytes = 0;
3edf7d33 CM	361	btrfs_add_ordered_sum(inode, ordered, sums);
3edf7d33 CM	362	btrfs_put_ordered_extent(ordered);
e015640f CM	363	return 0;
	364	}
	365
065631f6 CM	366	int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
065631f6 CM	367	struct btrfs_root root, struct inode inode,
e6dcd2dc	368	struct btrfs_ordered_sum *sums)
f254e52c	369	{
065631f6 CM	370	u64 objectid = inode->i_ino;
065631f6 CM	371	u64 offset;
f254e52c CM	372	int ret;
f254e52c CM	373	struct btrfs_key file_key;
6567e837	374	struct btrfs_key found_key;
065631f6	375	u64 next_offset;
e6dcd2dc	376	u64 total_bytes = 0;
065631f6	377	int found_next;
5caf2a00	378	struct btrfs_path *path;
f254e52c	379	struct btrfs_csum_item *item;
065631f6	380	struct btrfs_csum_item *item_end;
ff79f819	381	struct extent_buffer *leaf = NULL;
6567e837	382	u64 csum_offset;
e6dcd2dc	383	struct btrfs_sector_sum *sector_sum;
f578d4bd CM	384	u32 nritems;
f578d4bd CM	385	u32 ins_size;
6e92f5e6 CM	386	char *eb_map;
	387	char *eb_token;
	388	unsigned long map_len;
	389	unsigned long map_start;
607d432d JB	390	u16 csum_size =
607d432d JB	391	btrfs_super_csum_size(&root->fs_info->super_copy);
6e92f5e6	392
5caf2a00 CM	393	path = btrfs_alloc_path();
5caf2a00 CM	394	BUG_ON(!path);
ed98b56a	395	sector_sum = sums->sums;
065631f6 CM	396	again:
	397	next_offset = (u64)-1;
	398	found_next = 0;
e6dcd2dc	399	offset = sector_sum->offset;
f254e52c CM	400	file_key.objectid = objectid;
f254e52c CM	401	file_key.offset = offset;
f254e52c	402	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
a429e513	403
53863232	404	mutex_lock(&BTRFS_I(inode)->csum_mutex);
a429e513	405	item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
ff79f819 CM	406	if (!IS_ERR(item)) {
ff79f819 CM	407	leaf = path->nodes[0];
639cb586	408	ret = 0;
a429e513	409	goto found;
ff79f819	410	}
a429e513 CM	411	ret = PTR_ERR(item);
	412	if (ret == -EFBIG) {
	413	u32 item_size;
	414	/* we found one, but it isn't big enough yet */
5f39d397 CM	415	leaf = path->nodes[0];
5f39d397 CM	416	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
607d432d JB	417	if ((item_size / csum_size) >=
607d432d JB	418	MAX_CSUM_ITEMS(root, csum_size)) {
a429e513 CM	419	/* already at max size, make a new one */
	420	goto insert;
	421	}
	422	} else {
f578d4bd	423	int slot = path->slots[0] + 1;
a429e513	424	/* we didn't find a csum item, insert one */
f578d4bd CM	425	nritems = btrfs_header_nritems(path->nodes[0]);
	426	if (path->slots[0] >= nritems - 1) {
	427	ret = btrfs_next_leaf(root, path);
b56baf5b	428	if (ret == 1)
f578d4bd	429	found_next = 1;
b56baf5b	430	if (ret != 0)
f578d4bd	431	goto insert;
b56baf5b	432	slot = 0;
f578d4bd CM	433	}
	434	btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
	435	if (found_key.objectid != objectid \|\|
	436	found_key.type != BTRFS_CSUM_ITEM_KEY) {
	437	found_next = 1;
	438	goto insert;
	439	}
	440	next_offset = found_key.offset;
	441	found_next = 1;
a429e513 CM	442	goto insert;
	443	}
	444
	445	/*
	446	* at this point, we know the tree has an item, but it isn't big
	447	* enough yet to put our csum in. Grow it
	448	*/
	449	btrfs_release_path(root, path);
6567e837	450	ret = btrfs_search_slot(trans, root, &file_key, path,
607d432d	451	csum_size, 1);
6567e837	452	if (ret < 0)
53863232	453	goto fail_unlock;
6567e837	454	if (ret == 0) {
b18c6685	455	BUG();
6567e837 CM	456	}
6567e837 CM	457	if (path->slots[0] == 0) {
6567e837 CM	458	goto insert;
	459	}
	460	path->slots[0]--;
5f39d397 CM	461	leaf = path->nodes[0];
5f39d397 CM	462	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6567e837 CM	463	csum_offset = (offset - found_key.offset) >>
	464	root->fs_info->sb->s_blocksize_bits;
	465	if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY \|\|
	466	found_key.objectid != objectid \|\|
607d432d	467	csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
6567e837 CM	468	goto insert;
6567e837 CM	469	}
5f39d397	470	if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
607d432d JB	471	csum_size) {
607d432d JB	472	u32 diff = (csum_offset + 1) * csum_size;
5f39d397	473	diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
607d432d	474	if (diff != csum_size)
3a686375	475	goto insert;
a429e513	476	ret = btrfs_extend_item(trans, root, path, diff);
6567e837 CM	477	BUG_ON(ret);
	478	goto csum;
	479	}
	480
	481	insert:
a429e513	482	btrfs_release_path(root, path);
6567e837	483	csum_offset = 0;
f578d4bd CM	484	if (found_next) {
f578d4bd CM	485	u64 tmp = min((u64)i_size_read(inode), next_offset);
b56baf5b	486	tmp -= offset & ~((u64)root->sectorsize -1);
f578d4bd CM	487	tmp >>= root->fs_info->sb->s_blocksize_bits;
f578d4bd CM	488	tmp = max((u64)1, tmp);
607d432d JB	489	tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
607d432d JB	490	ins_size = csum_size * tmp;
f578d4bd	491	} else {
607d432d	492	ins_size = csum_size;
f578d4bd	493	}
5caf2a00	494	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
f578d4bd	495	ins_size);
54aa1f4d	496	if (ret < 0)
53863232	497	goto fail_unlock;
a429e513	498	if (ret != 0) {
a429e513	499	WARN_ON(1);
53863232	500	goto fail_unlock;
a429e513	501	}
6567e837	502	csum:
5f39d397 CM	503	leaf = path->nodes[0];
5f39d397 CM	504	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
f254e52c	505	ret = 0;
509659cd	506	item = (struct btrfs_csum_item )((unsigned char )item +
607d432d	507	csum_offset * csum_size);
b18c6685	508	found:
065631f6 CM	509	item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
	510	item_end = (struct btrfs_csum_item )((unsigned char )item_end +
	511	btrfs_item_size_nr(leaf, path->slots[0]));
6e92f5e6	512	eb_token = NULL;
53863232 CM	513	mutex_unlock(&BTRFS_I(inode)->csum_mutex);
53863232 CM	514	cond_resched();
e6dcd2dc	515	next_sector:
aadfeb6e	516
6e92f5e6	517	if (!eb_token \|\|
607d432d	518	(unsigned long)item + csum_size >= map_start + map_len) {
6e92f5e6 CM	519	int err;
	520
	521	if (eb_token)
eb20978f	522	unmap_extent_buffer(leaf, eb_token, KM_USER1);
6e92f5e6 CM	523	eb_token = NULL;
6e92f5e6 CM	524	err = map_private_extent_buffer(leaf, (unsigned long)item,
607d432d	525	csum_size,
6e92f5e6	526	&eb_token, &eb_map,
eb20978f	527	&map_start, &map_len, KM_USER1);
6e92f5e6 CM	528	if (err)
	529	eb_token = NULL;
	530	}
	531	if (eb_token) {
	532	memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
607d432d	533	&sector_sum->sum, csum_size);
6e92f5e6	534	} else {
e6dcd2dc	535	write_extent_buffer(leaf, &sector_sum->sum,
607d432d	536	(unsigned long)item, csum_size);
6e92f5e6	537	}
7f3c74fb	538
e6dcd2dc CM	539	total_bytes += root->sectorsize;
	540	sector_sum++;
	541	if (total_bytes < sums->len) {
6e92f5e6	542	item = (struct btrfs_csum_item )((char )item +
607d432d	543	csum_size);
2e1a992e	544	if (item < item_end && offset + PAGE_CACHE_SIZE ==
e6dcd2dc CM	545	sector_sum->offset) {
	546	offset = sector_sum->offset;
	547	goto next_sector;
2e1a992e	548	}
065631f6	549	}
6e92f5e6	550	if (eb_token) {
eb20978f	551	unmap_extent_buffer(leaf, eb_token, KM_USER1);
6e92f5e6 CM	552	eb_token = NULL;
6e92f5e6 CM	553	}
5caf2a00	554	btrfs_mark_buffer_dirty(path->nodes[0]);
53863232	555	cond_resched();
e6dcd2dc	556	if (total_bytes < sums->len) {
065631f6 CM	557	btrfs_release_path(root, path);
	558	goto again;
	559	}
53863232	560	out:
5caf2a00	561	btrfs_free_path(path);
f254e52c	562	return ret;
53863232 CM	563
	564	fail_unlock:
	565	mutex_unlock(&BTRFS_I(inode)->csum_mutex);
	566	goto out;
f254e52c CM	567	}
f254e52c CM	568
1de037a4 CM	569	int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
	570	struct btrfs_root root, struct btrfs_path path,
	571	u64 isize)
	572	{
	573	struct btrfs_key key;
5f39d397	574	struct extent_buffer *leaf = path->nodes[0];
1de037a4 CM	575	int slot = path->slots[0];
	576	int ret;
	577	u32 new_item_size;
	578	u64 new_item_span;
	579	u64 blocks;
	580
5f39d397	581	btrfs_item_key_to_cpu(leaf, &key, slot);
1de037a4 CM	582	if (isize <= key.offset)
	583	return 0;
	584	new_item_span = isize - key.offset;
5f39d397	585	blocks = (new_item_span + root->sectorsize - 1) >>
84f54cfa	586	root->fs_info->sb->s_blocksize_bits;
607d432d JB	587	new_item_size = blocks *
607d432d JB	588	btrfs_super_csum_size(&root->fs_info->super_copy);
5f39d397	589	if (new_item_size >= btrfs_item_size_nr(leaf, slot))
1de037a4	590	return 0;
179e29e4	591	ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);
1de037a4 CM	592	BUG_ON(ret);
	593	return ret;
	594	}