![Josef Bacik](/assets/img/avatar_default.png)
Got a report of a box panicing because we got a NULL eb in read_extent_buffer. His fs was borked and btrfs_search_path returned EIO, but we don't check for errors so the box paniced. Yes I know this will just make something higher up the stack panic, but that's a problem for future Josef. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
861 lines
23 KiB
C
861 lines
23 KiB
C
/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#include <linux/bio.h>
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#include <linux/slab.h>
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#include <linux/pagemap.h>
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#include <linux/highmem.h>
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#include "ctree.h"
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#include "disk-io.h"
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#include "transaction.h"
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#include "print-tree.h"
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#define MAX_CSUM_ITEMS(r, size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
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sizeof(struct btrfs_item) * 2) / \
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size) - 1))
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#define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
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sizeof(struct btrfs_ordered_sum)) / \
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sizeof(struct btrfs_sector_sum) * \
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(r)->sectorsize - (r)->sectorsize)
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int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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u64 objectid, u64 pos,
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u64 disk_offset, u64 disk_num_bytes,
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u64 num_bytes, u64 offset, u64 ram_bytes,
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u8 compression, u8 encryption, u16 other_encoding)
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{
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int ret = 0;
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struct btrfs_file_extent_item *item;
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struct btrfs_key file_key;
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struct btrfs_path *path;
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struct extent_buffer *leaf;
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path = btrfs_alloc_path();
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BUG_ON(!path);
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file_key.objectid = objectid;
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file_key.offset = pos;
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btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
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path->leave_spinning = 1;
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ret = btrfs_insert_empty_item(trans, root, path, &file_key,
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sizeof(*item));
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if (ret < 0)
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goto out;
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BUG_ON(ret);
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leaf = path->nodes[0];
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item = btrfs_item_ptr(leaf, path->slots[0],
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struct btrfs_file_extent_item);
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btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
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btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
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btrfs_set_file_extent_offset(leaf, item, offset);
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btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
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btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
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btrfs_set_file_extent_generation(leaf, item, trans->transid);
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btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
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btrfs_set_file_extent_compression(leaf, item, compression);
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btrfs_set_file_extent_encryption(leaf, item, encryption);
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btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
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btrfs_mark_buffer_dirty(leaf);
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out:
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btrfs_free_path(path);
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return ret;
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}
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struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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struct btrfs_path *path,
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u64 bytenr, int cow)
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{
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int ret;
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struct btrfs_key file_key;
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struct btrfs_key found_key;
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struct btrfs_csum_item *item;
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struct extent_buffer *leaf;
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u64 csum_offset = 0;
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u16 csum_size =
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btrfs_super_csum_size(&root->fs_info->super_copy);
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int csums_in_item;
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file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
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file_key.offset = bytenr;
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btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
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ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
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if (ret < 0)
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goto fail;
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leaf = path->nodes[0];
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if (ret > 0) {
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ret = 1;
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if (path->slots[0] == 0)
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goto fail;
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path->slots[0]--;
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btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
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if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
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goto fail;
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csum_offset = (bytenr - found_key.offset) >>
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root->fs_info->sb->s_blocksize_bits;
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csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
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csums_in_item /= csum_size;
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if (csum_offset >= csums_in_item) {
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ret = -EFBIG;
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goto fail;
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}
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}
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item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
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item = (struct btrfs_csum_item *)((unsigned char *)item +
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csum_offset * csum_size);
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return item;
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fail:
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if (ret > 0)
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ret = -ENOENT;
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return ERR_PTR(ret);
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}
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int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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struct btrfs_path *path, u64 objectid,
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u64 offset, int mod)
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{
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int ret;
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struct btrfs_key file_key;
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int ins_len = mod < 0 ? -1 : 0;
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int cow = mod != 0;
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file_key.objectid = objectid;
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file_key.offset = offset;
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btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
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ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
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return ret;
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}
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static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
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struct inode *inode, struct bio *bio,
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u64 logical_offset, u32 *dst, int dio)
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{
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u32 sum;
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struct bio_vec *bvec = bio->bi_io_vec;
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int bio_index = 0;
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u64 offset = 0;
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u64 item_start_offset = 0;
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u64 item_last_offset = 0;
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u64 disk_bytenr;
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u32 diff;
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u16 csum_size =
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btrfs_super_csum_size(&root->fs_info->super_copy);
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int ret;
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struct btrfs_path *path;
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struct btrfs_csum_item *item = NULL;
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struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
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path = btrfs_alloc_path();
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if (bio->bi_size > PAGE_CACHE_SIZE * 8)
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path->reada = 2;
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WARN_ON(bio->bi_vcnt <= 0);
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disk_bytenr = (u64)bio->bi_sector << 9;
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if (dio)
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offset = logical_offset;
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while (bio_index < bio->bi_vcnt) {
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if (!dio)
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offset = page_offset(bvec->bv_page) + bvec->bv_offset;
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ret = btrfs_find_ordered_sum(inode, offset, disk_bytenr, &sum);
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if (ret == 0)
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goto found;
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if (!item || disk_bytenr < item_start_offset ||
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disk_bytenr >= item_last_offset) {
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struct btrfs_key found_key;
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u32 item_size;
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if (item)
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btrfs_release_path(root, path);
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item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
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path, disk_bytenr, 0);
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if (IS_ERR(item)) {
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ret = PTR_ERR(item);
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if (ret == -ENOENT || ret == -EFBIG)
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ret = 0;
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sum = 0;
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if (BTRFS_I(inode)->root->root_key.objectid ==
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BTRFS_DATA_RELOC_TREE_OBJECTID) {
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set_extent_bits(io_tree, offset,
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offset + bvec->bv_len - 1,
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EXTENT_NODATASUM, GFP_NOFS);
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} else {
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printk(KERN_INFO "btrfs no csum found "
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"for inode %lu start %llu\n",
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inode->i_ino,
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(unsigned long long)offset);
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}
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item = NULL;
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btrfs_release_path(root, path);
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goto found;
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}
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btrfs_item_key_to_cpu(path->nodes[0], &found_key,
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path->slots[0]);
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item_start_offset = found_key.offset;
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item_size = btrfs_item_size_nr(path->nodes[0],
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path->slots[0]);
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item_last_offset = item_start_offset +
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(item_size / csum_size) *
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root->sectorsize;
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item = btrfs_item_ptr(path->nodes[0], path->slots[0],
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struct btrfs_csum_item);
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}
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/*
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* this byte range must be able to fit inside
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* a single leaf so it will also fit inside a u32
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*/
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diff = disk_bytenr - item_start_offset;
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diff = diff / root->sectorsize;
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diff = diff * csum_size;
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read_extent_buffer(path->nodes[0], &sum,
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((unsigned long)item) + diff,
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csum_size);
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found:
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if (dst)
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*dst++ = sum;
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else
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set_state_private(io_tree, offset, sum);
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disk_bytenr += bvec->bv_len;
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offset += bvec->bv_len;
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bio_index++;
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bvec++;
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}
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btrfs_free_path(path);
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return 0;
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}
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int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
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struct bio *bio, u32 *dst)
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{
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return __btrfs_lookup_bio_sums(root, inode, bio, 0, dst, 0);
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}
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int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
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struct bio *bio, u64 offset, u32 *dst)
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{
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return __btrfs_lookup_bio_sums(root, inode, bio, offset, dst, 1);
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}
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int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
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struct list_head *list)
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{
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struct btrfs_key key;
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struct btrfs_path *path;
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struct extent_buffer *leaf;
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struct btrfs_ordered_sum *sums;
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struct btrfs_sector_sum *sector_sum;
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struct btrfs_csum_item *item;
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unsigned long offset;
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int ret;
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size_t size;
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u64 csum_end;
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u16 csum_size = btrfs_super_csum_size(&root->fs_info->super_copy);
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path = btrfs_alloc_path();
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BUG_ON(!path);
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key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
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key.offset = start;
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key.type = BTRFS_EXTENT_CSUM_KEY;
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ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
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if (ret < 0)
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goto fail;
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if (ret > 0 && path->slots[0] > 0) {
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leaf = path->nodes[0];
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btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
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if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
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key.type == BTRFS_EXTENT_CSUM_KEY) {
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offset = (start - key.offset) >>
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root->fs_info->sb->s_blocksize_bits;
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if (offset * csum_size <
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btrfs_item_size_nr(leaf, path->slots[0] - 1))
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path->slots[0]--;
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}
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}
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while (start <= end) {
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leaf = path->nodes[0];
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if (path->slots[0] >= btrfs_header_nritems(leaf)) {
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ret = btrfs_next_leaf(root, path);
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if (ret < 0)
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goto fail;
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if (ret > 0)
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break;
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leaf = path->nodes[0];
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}
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btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
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if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
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key.type != BTRFS_EXTENT_CSUM_KEY)
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break;
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btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
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if (key.offset > end)
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break;
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if (key.offset > start)
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start = key.offset;
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size = btrfs_item_size_nr(leaf, path->slots[0]);
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csum_end = key.offset + (size / csum_size) * root->sectorsize;
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if (csum_end <= start) {
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path->slots[0]++;
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continue;
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}
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csum_end = min(csum_end, end + 1);
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item = btrfs_item_ptr(path->nodes[0], path->slots[0],
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struct btrfs_csum_item);
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while (start < csum_end) {
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size = min_t(size_t, csum_end - start,
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MAX_ORDERED_SUM_BYTES(root));
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sums = kzalloc(btrfs_ordered_sum_size(root, size),
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GFP_NOFS);
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BUG_ON(!sums);
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sector_sum = sums->sums;
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sums->bytenr = start;
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sums->len = size;
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offset = (start - key.offset) >>
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root->fs_info->sb->s_blocksize_bits;
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offset *= csum_size;
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while (size > 0) {
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read_extent_buffer(path->nodes[0],
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§or_sum->sum,
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((unsigned long)item) +
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offset, csum_size);
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sector_sum->bytenr = start;
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size -= root->sectorsize;
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start += root->sectorsize;
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offset += csum_size;
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sector_sum++;
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}
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list_add_tail(&sums->list, list);
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}
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path->slots[0]++;
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}
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ret = 0;
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fail:
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btrfs_free_path(path);
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return ret;
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}
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int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
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struct bio *bio, u64 file_start, int contig)
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{
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struct btrfs_ordered_sum *sums;
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struct btrfs_sector_sum *sector_sum;
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struct btrfs_ordered_extent *ordered;
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char *data;
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struct bio_vec *bvec = bio->bi_io_vec;
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int bio_index = 0;
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unsigned long total_bytes = 0;
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unsigned long this_sum_bytes = 0;
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u64 offset;
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u64 disk_bytenr;
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WARN_ON(bio->bi_vcnt <= 0);
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sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
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if (!sums)
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return -ENOMEM;
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sector_sum = sums->sums;
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disk_bytenr = (u64)bio->bi_sector << 9;
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sums->len = bio->bi_size;
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INIT_LIST_HEAD(&sums->list);
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if (contig)
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offset = file_start;
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else
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offset = page_offset(bvec->bv_page) + bvec->bv_offset;
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ordered = btrfs_lookup_ordered_extent(inode, offset);
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BUG_ON(!ordered);
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sums->bytenr = ordered->start;
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while (bio_index < bio->bi_vcnt) {
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if (!contig)
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offset = page_offset(bvec->bv_page) + bvec->bv_offset;
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if (!contig && (offset >= ordered->file_offset + ordered->len ||
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offset < ordered->file_offset)) {
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unsigned long bytes_left;
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sums->len = this_sum_bytes;
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this_sum_bytes = 0;
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btrfs_add_ordered_sum(inode, ordered, sums);
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btrfs_put_ordered_extent(ordered);
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bytes_left = bio->bi_size - total_bytes;
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sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
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GFP_NOFS);
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BUG_ON(!sums);
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sector_sum = sums->sums;
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sums->len = bytes_left;
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ordered = btrfs_lookup_ordered_extent(inode, offset);
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BUG_ON(!ordered);
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sums->bytenr = ordered->start;
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}
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data = kmap_atomic(bvec->bv_page, KM_USER0);
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sector_sum->sum = ~(u32)0;
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sector_sum->sum = btrfs_csum_data(root,
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data + bvec->bv_offset,
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sector_sum->sum,
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bvec->bv_len);
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kunmap_atomic(data, KM_USER0);
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btrfs_csum_final(sector_sum->sum,
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(char *)§or_sum->sum);
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sector_sum->bytenr = disk_bytenr;
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sector_sum++;
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bio_index++;
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total_bytes += bvec->bv_len;
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this_sum_bytes += bvec->bv_len;
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disk_bytenr += bvec->bv_len;
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offset += bvec->bv_len;
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bvec++;
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}
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this_sum_bytes = 0;
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btrfs_add_ordered_sum(inode, ordered, sums);
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btrfs_put_ordered_extent(ordered);
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return 0;
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}
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/*
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* helper function for csum removal, this expects the
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* key to describe the csum pointed to by the path, and it expects
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* the csum to overlap the range [bytenr, len]
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*
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* The csum should not be entirely contained in the range and the
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* range should not be entirely contained in the csum.
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*
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* This calls btrfs_truncate_item with the correct args based on the
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* overlap, and fixes up the key as required.
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*/
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static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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struct btrfs_path *path,
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struct btrfs_key *key,
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u64 bytenr, u64 len)
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{
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struct extent_buffer *leaf;
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u16 csum_size =
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btrfs_super_csum_size(&root->fs_info->super_copy);
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u64 csum_end;
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u64 end_byte = bytenr + len;
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u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
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int ret;
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leaf = path->nodes[0];
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csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
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csum_end <<= root->fs_info->sb->s_blocksize_bits;
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csum_end += key->offset;
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if (key->offset < bytenr && csum_end <= end_byte) {
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/*
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* [ bytenr - len ]
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* [ ]
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* [csum ]
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* A simple truncate off the end of the item
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*/
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u32 new_size = (bytenr - key->offset) >> blocksize_bits;
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new_size *= csum_size;
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ret = btrfs_truncate_item(trans, root, path, new_size, 1);
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BUG_ON(ret);
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} else if (key->offset >= bytenr && csum_end > end_byte &&
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end_byte > key->offset) {
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/*
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* [ bytenr - len ]
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* [ ]
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* [csum ]
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* we need to truncate from the beginning of the csum
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*/
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u32 new_size = (csum_end - end_byte) >> blocksize_bits;
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new_size *= csum_size;
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ret = btrfs_truncate_item(trans, root, path, new_size, 0);
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BUG_ON(ret);
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key->offset = end_byte;
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ret = btrfs_set_item_key_safe(trans, root, path, key);
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BUG_ON(ret);
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} else {
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BUG();
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}
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return 0;
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}
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/*
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* deletes the csum items from the csum tree for a given
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* range of bytes.
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*/
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int btrfs_del_csums(struct btrfs_trans_handle *trans,
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struct btrfs_root *root, u64 bytenr, u64 len)
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{
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struct btrfs_path *path;
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struct btrfs_key key;
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u64 end_byte = bytenr + len;
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u64 csum_end;
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struct extent_buffer *leaf;
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int ret;
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u16 csum_size =
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btrfs_super_csum_size(&root->fs_info->super_copy);
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int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
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root = root->fs_info->csum_root;
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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while (1) {
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key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
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key.offset = end_byte - 1;
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key.type = BTRFS_EXTENT_CSUM_KEY;
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path->leave_spinning = 1;
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ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
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if (ret > 0) {
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if (path->slots[0] == 0)
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goto out;
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path->slots[0]--;
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} else if (ret < 0) {
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goto out;
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}
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leaf = path->nodes[0];
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btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
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if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
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key.type != BTRFS_EXTENT_CSUM_KEY) {
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break;
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}
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if (key.offset >= end_byte)
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break;
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csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
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csum_end <<= blocksize_bits;
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csum_end += key.offset;
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/* this csum ends before we start, we're done */
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if (csum_end <= bytenr)
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break;
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/* delete the entire item, it is inside our range */
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if (key.offset >= bytenr && csum_end <= end_byte) {
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ret = btrfs_del_item(trans, root, path);
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BUG_ON(ret);
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if (key.offset == bytenr)
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break;
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} else if (key.offset < bytenr && csum_end > end_byte) {
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unsigned long offset;
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unsigned long shift_len;
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unsigned long item_offset;
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/*
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* [ bytenr - len ]
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* [csum ]
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*
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* Our bytes are in the middle of the csum,
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* we need to split this item and insert a new one.
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*
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* But we can't drop the path because the
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* csum could change, get removed, extended etc.
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*
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* The trick here is the max size of a csum item leaves
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* enough room in the tree block for a single
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* item header. So, we split the item in place,
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* adding a new header pointing to the existing
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* bytes. Then we loop around again and we have
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* a nicely formed csum item that we can neatly
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* truncate.
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*/
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offset = (bytenr - key.offset) >> blocksize_bits;
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offset *= csum_size;
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shift_len = (len >> blocksize_bits) * csum_size;
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item_offset = btrfs_item_ptr_offset(leaf,
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path->slots[0]);
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memset_extent_buffer(leaf, 0, item_offset + offset,
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shift_len);
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key.offset = bytenr;
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/*
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* btrfs_split_item returns -EAGAIN when the
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* item changed size or key
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*/
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ret = btrfs_split_item(trans, root, path, &key, offset);
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BUG_ON(ret && ret != -EAGAIN);
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key.offset = end_byte - 1;
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} else {
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ret = truncate_one_csum(trans, root, path,
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&key, bytenr, len);
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BUG_ON(ret);
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if (key.offset < bytenr)
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break;
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}
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btrfs_release_path(root, path);
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}
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out:
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btrfs_free_path(path);
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return 0;
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}
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int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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struct btrfs_ordered_sum *sums)
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{
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u64 bytenr;
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int ret;
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struct btrfs_key file_key;
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struct btrfs_key found_key;
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u64 next_offset;
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u64 total_bytes = 0;
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int found_next;
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struct btrfs_path *path;
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struct btrfs_csum_item *item;
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struct btrfs_csum_item *item_end;
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struct extent_buffer *leaf = NULL;
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u64 csum_offset;
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struct btrfs_sector_sum *sector_sum;
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u32 nritems;
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u32 ins_size;
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char *eb_map;
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char *eb_token;
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unsigned long map_len;
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unsigned long map_start;
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u16 csum_size =
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btrfs_super_csum_size(&root->fs_info->super_copy);
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path = btrfs_alloc_path();
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BUG_ON(!path);
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sector_sum = sums->sums;
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again:
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next_offset = (u64)-1;
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found_next = 0;
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file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
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file_key.offset = sector_sum->bytenr;
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bytenr = sector_sum->bytenr;
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btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
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item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1);
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if (!IS_ERR(item)) {
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leaf = path->nodes[0];
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ret = 0;
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goto found;
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}
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ret = PTR_ERR(item);
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if (ret != -EFBIG && ret != -ENOENT)
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goto fail_unlock;
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if (ret == -EFBIG) {
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u32 item_size;
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/* we found one, but it isn't big enough yet */
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leaf = path->nodes[0];
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item_size = btrfs_item_size_nr(leaf, path->slots[0]);
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if ((item_size / csum_size) >=
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MAX_CSUM_ITEMS(root, csum_size)) {
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/* already at max size, make a new one */
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goto insert;
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}
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} else {
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int slot = path->slots[0] + 1;
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/* we didn't find a csum item, insert one */
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nritems = btrfs_header_nritems(path->nodes[0]);
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if (path->slots[0] >= nritems - 1) {
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ret = btrfs_next_leaf(root, path);
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if (ret == 1)
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found_next = 1;
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if (ret != 0)
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goto insert;
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slot = 0;
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}
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btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
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if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
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found_key.type != BTRFS_EXTENT_CSUM_KEY) {
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found_next = 1;
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goto insert;
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}
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next_offset = found_key.offset;
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found_next = 1;
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goto insert;
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}
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/*
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* at this point, we know the tree has an item, but it isn't big
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* enough yet to put our csum in. Grow it
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*/
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btrfs_release_path(root, path);
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ret = btrfs_search_slot(trans, root, &file_key, path,
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csum_size, 1);
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if (ret < 0)
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goto fail_unlock;
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if (ret > 0) {
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if (path->slots[0] == 0)
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goto insert;
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path->slots[0]--;
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}
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leaf = path->nodes[0];
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btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
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csum_offset = (bytenr - found_key.offset) >>
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root->fs_info->sb->s_blocksize_bits;
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if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY ||
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found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
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csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
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goto insert;
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}
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if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
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csum_size) {
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u32 diff = (csum_offset + 1) * csum_size;
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/*
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* is the item big enough already? we dropped our lock
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* before and need to recheck
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*/
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if (diff < btrfs_item_size_nr(leaf, path->slots[0]))
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goto csum;
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diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
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if (diff != csum_size)
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goto insert;
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ret = btrfs_extend_item(trans, root, path, diff);
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BUG_ON(ret);
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goto csum;
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}
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insert:
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btrfs_release_path(root, path);
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csum_offset = 0;
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if (found_next) {
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u64 tmp = total_bytes + root->sectorsize;
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u64 next_sector = sector_sum->bytenr;
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struct btrfs_sector_sum *next = sector_sum + 1;
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while (tmp < sums->len) {
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if (next_sector + root->sectorsize != next->bytenr)
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break;
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tmp += root->sectorsize;
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next_sector = next->bytenr;
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next++;
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}
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tmp = min(tmp, next_offset - file_key.offset);
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tmp >>= root->fs_info->sb->s_blocksize_bits;
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tmp = max((u64)1, tmp);
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tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
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ins_size = csum_size * tmp;
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} else {
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ins_size = csum_size;
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}
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path->leave_spinning = 1;
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ret = btrfs_insert_empty_item(trans, root, path, &file_key,
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ins_size);
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path->leave_spinning = 0;
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if (ret < 0)
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goto fail_unlock;
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if (ret != 0) {
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WARN_ON(1);
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goto fail_unlock;
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}
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csum:
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leaf = path->nodes[0];
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item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
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ret = 0;
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item = (struct btrfs_csum_item *)((unsigned char *)item +
|
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csum_offset * csum_size);
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found:
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item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
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item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
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btrfs_item_size_nr(leaf, path->slots[0]));
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eb_token = NULL;
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next_sector:
|
|
|
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if (!eb_token ||
|
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(unsigned long)item + csum_size >= map_start + map_len) {
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int err;
|
|
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if (eb_token)
|
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unmap_extent_buffer(leaf, eb_token, KM_USER1);
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eb_token = NULL;
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err = map_private_extent_buffer(leaf, (unsigned long)item,
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csum_size,
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&eb_token, &eb_map,
|
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&map_start, &map_len, KM_USER1);
|
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if (err)
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eb_token = NULL;
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}
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if (eb_token) {
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memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
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§or_sum->sum, csum_size);
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} else {
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write_extent_buffer(leaf, §or_sum->sum,
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(unsigned long)item, csum_size);
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}
|
|
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total_bytes += root->sectorsize;
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sector_sum++;
|
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if (total_bytes < sums->len) {
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item = (struct btrfs_csum_item *)((char *)item +
|
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csum_size);
|
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if (item < item_end && bytenr + PAGE_CACHE_SIZE ==
|
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sector_sum->bytenr) {
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bytenr = sector_sum->bytenr;
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goto next_sector;
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}
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}
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if (eb_token) {
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unmap_extent_buffer(leaf, eb_token, KM_USER1);
|
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eb_token = NULL;
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}
|
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btrfs_mark_buffer_dirty(path->nodes[0]);
|
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if (total_bytes < sums->len) {
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btrfs_release_path(root, path);
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cond_resched();
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goto again;
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}
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out:
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btrfs_free_path(path);
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return ret;
|
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|
|
fail_unlock:
|
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goto out;
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|
}
|