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![Qu Wenruo](/assets/img/avatar_default.png)
This cleans up the now unneeded code from the old btrfs implementation. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Marek Behún <marek.behun@nic.cz>
743 lines
18 KiB
C
743 lines
18 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* BTRFS filesystem implementation for U-Boot
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*
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* 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
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*/
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#include <linux/kernel.h>
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#include <log.h>
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#include <malloc.h>
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#include <memalign.h>
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#include "btrfs.h"
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#include "disk-io.h"
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static const struct btrfs_csum {
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u16 size;
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const char name[14];
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} btrfs_csums[] = {
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[BTRFS_CSUM_TYPE_CRC32] = { 4, "crc32c" },
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[BTRFS_CSUM_TYPE_XXHASH] = { 8, "xxhash64" },
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[BTRFS_CSUM_TYPE_SHA256] = { 32, "sha256" },
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[BTRFS_CSUM_TYPE_BLAKE2] = { 32, "blake2" },
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};
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u16 btrfs_super_csum_size(const struct btrfs_super_block *sb)
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{
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const u16 csum_type = btrfs_super_csum_type(sb);
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return btrfs_csums[csum_type].size;
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}
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const char *btrfs_super_csum_name(u16 csum_type)
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{
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return btrfs_csums[csum_type].name;
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}
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size_t btrfs_super_num_csums(void)
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{
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return ARRAY_SIZE(btrfs_csums);
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}
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u16 btrfs_csum_type_size(u16 csum_type)
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{
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return btrfs_csums[csum_type].size;
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}
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struct btrfs_path *btrfs_alloc_path(void)
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{
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struct btrfs_path *path;
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path = kzalloc(sizeof(struct btrfs_path), GFP_NOFS);
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return path;
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}
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void btrfs_free_path(struct btrfs_path *p)
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{
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if (!p)
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return;
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btrfs_release_path(p);
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kfree(p);
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}
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void btrfs_release_path(struct btrfs_path *p)
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{
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int i;
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for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
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if (!p->nodes[i])
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continue;
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free_extent_buffer(p->nodes[i]);
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}
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memset(p, 0, sizeof(*p));
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}
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int btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2)
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{
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if (k1->objectid > k2->objectid)
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return 1;
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if (k1->objectid < k2->objectid)
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return -1;
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if (k1->type > k2->type)
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return 1;
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if (k1->type < k2->type)
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return -1;
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if (k1->offset > k2->offset)
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return 1;
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if (k1->offset < k2->offset)
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return -1;
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return 0;
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}
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static int btrfs_comp_keys(struct btrfs_disk_key *disk,
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const struct btrfs_key *k2)
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{
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struct btrfs_key k1;
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btrfs_disk_key_to_cpu(&k1, disk);
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return btrfs_comp_cpu_keys(&k1, k2);
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}
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enum btrfs_tree_block_status
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btrfs_check_node(struct btrfs_fs_info *fs_info,
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struct btrfs_disk_key *parent_key, struct extent_buffer *buf)
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{
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int i;
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struct btrfs_key cpukey;
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struct btrfs_disk_key key;
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u32 nritems = btrfs_header_nritems(buf);
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enum btrfs_tree_block_status ret = BTRFS_TREE_BLOCK_INVALID_NRITEMS;
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if (nritems == 0 || nritems > BTRFS_NODEPTRS_PER_BLOCK(fs_info))
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goto fail;
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ret = BTRFS_TREE_BLOCK_INVALID_PARENT_KEY;
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if (parent_key && parent_key->type) {
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btrfs_node_key(buf, &key, 0);
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if (memcmp(parent_key, &key, sizeof(key)))
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goto fail;
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}
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ret = BTRFS_TREE_BLOCK_BAD_KEY_ORDER;
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for (i = 0; nritems > 1 && i < nritems - 2; i++) {
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btrfs_node_key(buf, &key, i);
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btrfs_node_key_to_cpu(buf, &cpukey, i + 1);
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if (btrfs_comp_keys(&key, &cpukey) >= 0)
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goto fail;
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}
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return BTRFS_TREE_BLOCK_CLEAN;
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fail:
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return ret;
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}
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enum btrfs_tree_block_status
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btrfs_check_leaf(struct btrfs_fs_info *fs_info,
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struct btrfs_disk_key *parent_key, struct extent_buffer *buf)
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{
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int i;
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struct btrfs_key cpukey;
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struct btrfs_disk_key key;
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u32 nritems = btrfs_header_nritems(buf);
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enum btrfs_tree_block_status ret = BTRFS_TREE_BLOCK_INVALID_NRITEMS;
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if (nritems * sizeof(struct btrfs_item) > buf->len) {
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fprintf(stderr, "invalid number of items %llu\n",
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(unsigned long long)buf->start);
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goto fail;
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}
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if (btrfs_header_level(buf) != 0) {
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ret = BTRFS_TREE_BLOCK_INVALID_LEVEL;
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fprintf(stderr, "leaf is not a leaf %llu\n",
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(unsigned long long)btrfs_header_bytenr(buf));
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goto fail;
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}
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if (btrfs_leaf_free_space(buf) < 0) {
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ret = BTRFS_TREE_BLOCK_INVALID_FREE_SPACE;
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fprintf(stderr, "leaf free space incorrect %llu %d\n",
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(unsigned long long)btrfs_header_bytenr(buf),
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btrfs_leaf_free_space(buf));
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goto fail;
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}
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if (nritems == 0)
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return BTRFS_TREE_BLOCK_CLEAN;
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btrfs_item_key(buf, &key, 0);
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if (parent_key && parent_key->type &&
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memcmp(parent_key, &key, sizeof(key))) {
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ret = BTRFS_TREE_BLOCK_INVALID_PARENT_KEY;
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fprintf(stderr, "leaf parent key incorrect %llu\n",
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(unsigned long long)btrfs_header_bytenr(buf));
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goto fail;
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}
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for (i = 0; nritems > 1 && i < nritems - 1; i++) {
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btrfs_item_key(buf, &key, i);
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btrfs_item_key_to_cpu(buf, &cpukey, i + 1);
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if (btrfs_comp_keys(&key, &cpukey) >= 0) {
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ret = BTRFS_TREE_BLOCK_BAD_KEY_ORDER;
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fprintf(stderr, "bad key ordering %d %d\n", i, i+1);
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goto fail;
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}
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if (btrfs_item_offset_nr(buf, i) !=
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btrfs_item_end_nr(buf, i + 1)) {
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ret = BTRFS_TREE_BLOCK_INVALID_OFFSETS;
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fprintf(stderr, "incorrect offsets %u %u\n",
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btrfs_item_offset_nr(buf, i),
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btrfs_item_end_nr(buf, i + 1));
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goto fail;
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}
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if (i == 0 && btrfs_item_end_nr(buf, i) !=
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BTRFS_LEAF_DATA_SIZE(fs_info)) {
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ret = BTRFS_TREE_BLOCK_INVALID_OFFSETS;
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fprintf(stderr, "bad item end %u wanted %u\n",
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btrfs_item_end_nr(buf, i),
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(unsigned)BTRFS_LEAF_DATA_SIZE(fs_info));
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goto fail;
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}
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}
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for (i = 0; i < nritems; i++) {
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if (btrfs_item_end_nr(buf, i) >
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BTRFS_LEAF_DATA_SIZE(fs_info)) {
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btrfs_item_key(buf, &key, 0);
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ret = BTRFS_TREE_BLOCK_INVALID_OFFSETS;
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fprintf(stderr, "slot end outside of leaf %llu > %llu\n",
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(unsigned long long)btrfs_item_end_nr(buf, i),
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(unsigned long long)BTRFS_LEAF_DATA_SIZE(
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fs_info));
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goto fail;
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}
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}
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return BTRFS_TREE_BLOCK_CLEAN;
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fail:
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return ret;
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}
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static int noinline check_block(struct btrfs_fs_info *fs_info,
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struct btrfs_path *path, int level)
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{
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struct btrfs_disk_key key;
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struct btrfs_disk_key *key_ptr = NULL;
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struct extent_buffer *parent;
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enum btrfs_tree_block_status ret;
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if (path->nodes[level + 1]) {
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parent = path->nodes[level + 1];
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btrfs_node_key(parent, &key, path->slots[level + 1]);
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key_ptr = &key;
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}
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if (level == 0)
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ret = btrfs_check_leaf(fs_info, key_ptr, path->nodes[0]);
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else
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ret = btrfs_check_node(fs_info, key_ptr, path->nodes[level]);
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if (ret == BTRFS_TREE_BLOCK_CLEAN)
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return 0;
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return -EIO;
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}
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/*
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* search for key in the extent_buffer. The items start at offset p,
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* and they are item_size apart. There are 'max' items in p.
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*
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* the slot in the array is returned via slot, and it points to
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* the place where you would insert key if it is not found in
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* the array.
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*
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* slot may point to max if the key is bigger than all of the keys
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*/
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static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
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int item_size, const struct btrfs_key *key,
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int max, int *slot)
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{
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int low = 0;
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int high = max;
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int mid;
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int ret;
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unsigned long offset;
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struct btrfs_disk_key *tmp;
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while(low < high) {
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mid = (low + high) / 2;
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offset = p + mid * item_size;
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tmp = (struct btrfs_disk_key *)(eb->data + offset);
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ret = btrfs_comp_keys(tmp, key);
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if (ret < 0)
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low = mid + 1;
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else if (ret > 0)
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high = mid;
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else {
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*slot = mid;
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return 0;
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}
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}
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*slot = low;
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return 1;
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}
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/*
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* simple bin_search frontend that does the right thing for
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* leaves vs nodes
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*/
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int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
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int *slot)
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{
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if (btrfs_header_level(eb) == 0)
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return generic_bin_search(eb,
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offsetof(struct btrfs_leaf, items),
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sizeof(struct btrfs_item),
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key, btrfs_header_nritems(eb),
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slot);
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else
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return generic_bin_search(eb,
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offsetof(struct btrfs_node, ptrs),
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sizeof(struct btrfs_key_ptr),
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key, btrfs_header_nritems(eb),
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slot);
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}
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struct extent_buffer *read_node_slot(struct btrfs_fs_info *fs_info,
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struct extent_buffer *parent, int slot)
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{
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struct extent_buffer *ret;
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int level = btrfs_header_level(parent);
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if (slot < 0)
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return NULL;
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if (slot >= btrfs_header_nritems(parent))
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return NULL;
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if (level == 0)
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return NULL;
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ret = read_tree_block(fs_info, btrfs_node_blockptr(parent, slot),
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btrfs_node_ptr_generation(parent, slot));
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if (!extent_buffer_uptodate(ret))
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return ERR_PTR(-EIO);
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if (btrfs_header_level(ret) != level - 1) {
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error("child eb corrupted: parent bytenr=%llu item=%d parent level=%d child level=%d",
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btrfs_header_bytenr(parent), slot,
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btrfs_header_level(parent), btrfs_header_level(ret));
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free_extent_buffer(ret);
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return ERR_PTR(-EIO);
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}
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return ret;
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}
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int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *found_path,
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u64 iobjectid, u64 ioff, u8 key_type,
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struct btrfs_key *found_key)
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{
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int ret;
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struct btrfs_key key;
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struct extent_buffer *eb;
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struct btrfs_path *path;
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key.type = key_type;
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key.objectid = iobjectid;
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key.offset = ioff;
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if (found_path == NULL) {
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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} else
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path = found_path;
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ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
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if ((ret < 0) || (found_key == NULL))
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goto out;
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eb = path->nodes[0];
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if (ret && path->slots[0] >= btrfs_header_nritems(eb)) {
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ret = btrfs_next_leaf(fs_root, path);
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if (ret)
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goto out;
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eb = path->nodes[0];
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}
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btrfs_item_key_to_cpu(eb, found_key, path->slots[0]);
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if (found_key->type != key.type ||
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found_key->objectid != key.objectid) {
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ret = 1;
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goto out;
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}
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out:
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if (path != found_path)
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btrfs_free_path(path);
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return ret;
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}
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/*
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* look for key in the tree. path is filled in with nodes along the way
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* if key is found, we return zero and you can find the item in the leaf
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* level of the path (level 0)
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*
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* If the key isn't found, the path points to the slot where it should
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* be inserted, and 1 is returned. If there are other errors during the
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* search a negative error number is returned.
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*
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* if ins_len > 0, nodes and leaves will be split as we walk down the
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* tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
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* possible)
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*
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* NOTE: This version has no COW ability, thus we expect trans == NULL,
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* ins_len == 0 and cow == 0.
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*/
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int btrfs_search_slot(struct btrfs_trans_handle *trans,
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struct btrfs_root *root, const struct btrfs_key *key,
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struct btrfs_path *p, int ins_len, int cow)
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{
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struct extent_buffer *b;
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int slot;
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int ret;
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int level;
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struct btrfs_fs_info *fs_info = root->fs_info;
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u8 lowest_level = 0;
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assert(trans == NULL && ins_len == 0 && cow == 0);
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lowest_level = p->lowest_level;
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WARN_ON(lowest_level && ins_len > 0);
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WARN_ON(p->nodes[0] != NULL);
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b = root->node;
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extent_buffer_get(b);
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while (b) {
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level = btrfs_header_level(b);
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/*
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if (cow) {
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int wret;
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wret = btrfs_cow_block(trans, root, b,
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p->nodes[level + 1],
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p->slots[level + 1],
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&b);
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if (wret) {
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free_extent_buffer(b);
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return wret;
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}
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}
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*/
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BUG_ON(!cow && ins_len);
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if (level != btrfs_header_level(b))
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WARN_ON(1);
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level = btrfs_header_level(b);
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p->nodes[level] = b;
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ret = check_block(fs_info, p, level);
|
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if (ret)
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return -1;
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ret = btrfs_bin_search(b, key, &slot);
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if (level != 0) {
|
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if (ret && slot > 0)
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slot -= 1;
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p->slots[level] = slot;
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/*
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if ((p->search_for_split || ins_len > 0) &&
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btrfs_header_nritems(b) >=
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BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) {
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int sret = split_node(trans, root, p, level);
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BUG_ON(sret > 0);
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if (sret)
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return sret;
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b = p->nodes[level];
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slot = p->slots[level];
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} else if (ins_len < 0) {
|
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int sret = balance_level(trans, root, p,
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level);
|
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if (sret)
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return sret;
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b = p->nodes[level];
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if (!b) {
|
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btrfs_release_path(p);
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goto again;
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}
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slot = p->slots[level];
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BUG_ON(btrfs_header_nritems(b) == 1);
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}
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*/
|
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/* this is only true while dropping a snapshot */
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if (level == lowest_level)
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break;
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b = read_node_slot(fs_info, b, slot);
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if (!extent_buffer_uptodate(b))
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return -EIO;
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} else {
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p->slots[level] = slot;
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/*
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if (ins_len > 0 &&
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ins_len > btrfs_leaf_free_space(b)) {
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int sret = split_leaf(trans, root, key,
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p, ins_len, ret == 0);
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BUG_ON(sret > 0);
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if (sret)
|
|
return sret;
|
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}
|
|
*/
|
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return ret;
|
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}
|
|
}
|
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return 1;
|
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}
|
|
|
|
/*
|
|
* Helper to use instead of search slot if no exact match is needed but
|
|
* instead the next or previous item should be returned.
|
|
* When find_higher is true, the next higher item is returned, the next lower
|
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* otherwise.
|
|
* When return_any and find_higher are both true, and no higher item is found,
|
|
* return the next lower instead.
|
|
* When return_any is true and find_higher is false, and no lower item is found,
|
|
* return the next higher instead.
|
|
* It returns 0 if any item is found, 1 if none is found (tree empty), and
|
|
* < 0 on error
|
|
*/
|
|
int btrfs_search_slot_for_read(struct btrfs_root *root,
|
|
const struct btrfs_key *key,
|
|
struct btrfs_path *p, int find_higher,
|
|
int return_any)
|
|
{
|
|
int ret;
|
|
struct extent_buffer *leaf;
|
|
|
|
again:
|
|
ret = btrfs_search_slot(NULL, root, key, p, 0, 0);
|
|
if (ret <= 0)
|
|
return ret;
|
|
/*
|
|
* A return value of 1 means the path is at the position where the item
|
|
* should be inserted. Normally this is the next bigger item, but in
|
|
* case the previous item is the last in a leaf, path points to the
|
|
* first free slot in the previous leaf, i.e. at an invalid item.
|
|
*/
|
|
leaf = p->nodes[0];
|
|
|
|
if (find_higher) {
|
|
if (p->slots[0] >= btrfs_header_nritems(leaf)) {
|
|
ret = btrfs_next_leaf(root, p);
|
|
if (ret <= 0)
|
|
return ret;
|
|
if (!return_any)
|
|
return 1;
|
|
/*
|
|
* No higher item found, return the next lower instead
|
|
*/
|
|
return_any = 0;
|
|
find_higher = 0;
|
|
btrfs_release_path(p);
|
|
goto again;
|
|
}
|
|
} else {
|
|
if (p->slots[0] == 0) {
|
|
ret = btrfs_prev_leaf(root, p);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (!ret) {
|
|
leaf = p->nodes[0];
|
|
if (p->slots[0] == btrfs_header_nritems(leaf))
|
|
p->slots[0]--;
|
|
return 0;
|
|
}
|
|
if (!return_any)
|
|
return 1;
|
|
/*
|
|
* No lower item found, return the next higher instead
|
|
*/
|
|
return_any = 0;
|
|
find_higher = 1;
|
|
btrfs_release_path(p);
|
|
goto again;
|
|
} else {
|
|
--p->slots[0];
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* how many bytes are required to store the items in a leaf. start
|
|
* and nr indicate which items in the leaf to check. This totals up the
|
|
* space used both by the item structs and the item data
|
|
*/
|
|
static int leaf_space_used(struct extent_buffer *l, int start, int nr)
|
|
{
|
|
int data_len;
|
|
int nritems = btrfs_header_nritems(l);
|
|
int end = min(nritems, start + nr) - 1;
|
|
|
|
if (!nr)
|
|
return 0;
|
|
data_len = btrfs_item_end_nr(l, start);
|
|
data_len = data_len - btrfs_item_offset_nr(l, end);
|
|
data_len += sizeof(struct btrfs_item) * nr;
|
|
WARN_ON(data_len < 0);
|
|
return data_len;
|
|
}
|
|
|
|
/*
|
|
* The space between the end of the leaf items and
|
|
* the start of the leaf data. IOW, how much room
|
|
* the leaf has left for both items and data
|
|
*/
|
|
int btrfs_leaf_free_space(struct extent_buffer *leaf)
|
|
{
|
|
int nritems = btrfs_header_nritems(leaf);
|
|
u32 leaf_data_size;
|
|
int ret;
|
|
|
|
BUG_ON(leaf->fs_info && leaf->fs_info->nodesize != leaf->len);
|
|
leaf_data_size = __BTRFS_LEAF_DATA_SIZE(leaf->len);
|
|
ret = leaf_data_size - leaf_space_used(leaf, 0 ,nritems);
|
|
if (ret < 0) {
|
|
printk("leaf free space ret %d, leaf data size %u, used %d nritems %d\n",
|
|
ret, leaf_data_size, leaf_space_used(leaf, 0, nritems),
|
|
nritems);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* walk up the tree as far as required to find the previous leaf.
|
|
* returns 0 if it found something or 1 if there are no lesser leaves.
|
|
* returns < 0 on io errors.
|
|
*/
|
|
int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
|
|
{
|
|
int slot;
|
|
int level = 1;
|
|
struct extent_buffer *c;
|
|
struct extent_buffer *next = NULL;
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
|
|
while(level < BTRFS_MAX_LEVEL) {
|
|
if (!path->nodes[level])
|
|
return 1;
|
|
|
|
slot = path->slots[level];
|
|
c = path->nodes[level];
|
|
if (slot == 0) {
|
|
level++;
|
|
if (level == BTRFS_MAX_LEVEL)
|
|
return 1;
|
|
continue;
|
|
}
|
|
slot--;
|
|
|
|
next = read_node_slot(fs_info, c, slot);
|
|
if (!extent_buffer_uptodate(next)) {
|
|
if (IS_ERR(next))
|
|
return PTR_ERR(next);
|
|
return -EIO;
|
|
}
|
|
break;
|
|
}
|
|
path->slots[level] = slot;
|
|
while(1) {
|
|
level--;
|
|
c = path->nodes[level];
|
|
free_extent_buffer(c);
|
|
slot = btrfs_header_nritems(next);
|
|
if (slot != 0)
|
|
slot--;
|
|
path->nodes[level] = next;
|
|
path->slots[level] = slot;
|
|
if (!level)
|
|
break;
|
|
next = read_node_slot(fs_info, next, slot);
|
|
if (!extent_buffer_uptodate(next)) {
|
|
if (IS_ERR(next))
|
|
return PTR_ERR(next);
|
|
return -EIO;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Walk up the tree as far as necessary to find the next sibling tree block.
|
|
* More generic version of btrfs_next_leaf(), as it could find sibling nodes
|
|
* if @path->lowest_level is not 0.
|
|
*
|
|
* returns 0 if it found something or 1 if there are no greater leaves.
|
|
* returns < 0 on io errors.
|
|
*/
|
|
int btrfs_next_sibling_tree_block(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_path *path)
|
|
{
|
|
int slot;
|
|
int level = path->lowest_level + 1;
|
|
struct extent_buffer *c;
|
|
struct extent_buffer *next = NULL;
|
|
|
|
BUG_ON(path->lowest_level + 1 >= BTRFS_MAX_LEVEL);
|
|
do {
|
|
if (!path->nodes[level])
|
|
return 1;
|
|
|
|
slot = path->slots[level] + 1;
|
|
c = path->nodes[level];
|
|
if (slot >= btrfs_header_nritems(c)) {
|
|
level++;
|
|
if (level == BTRFS_MAX_LEVEL)
|
|
return 1;
|
|
continue;
|
|
}
|
|
|
|
next = read_node_slot(fs_info, c, slot);
|
|
if (!extent_buffer_uptodate(next))
|
|
return -EIO;
|
|
break;
|
|
} while (level < BTRFS_MAX_LEVEL);
|
|
path->slots[level] = slot;
|
|
while(1) {
|
|
level--;
|
|
c = path->nodes[level];
|
|
free_extent_buffer(c);
|
|
path->nodes[level] = next;
|
|
path->slots[level] = 0;
|
|
if (level == path->lowest_level)
|
|
break;
|
|
next = read_node_slot(fs_info, next, 0);
|
|
if (!extent_buffer_uptodate(next))
|
|
return -EIO;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int btrfs_previous_item(struct btrfs_root *root,
|
|
struct btrfs_path *path, u64 min_objectid,
|
|
int type)
|
|
{
|
|
struct btrfs_key found_key;
|
|
struct extent_buffer *leaf;
|
|
u32 nritems;
|
|
int ret;
|
|
|
|
while(1) {
|
|
if (path->slots[0] == 0) {
|
|
ret = btrfs_prev_leaf(root, path);
|
|
if (ret != 0)
|
|
return ret;
|
|
} else {
|
|
path->slots[0]--;
|
|
}
|
|
leaf = path->nodes[0];
|
|
nritems = btrfs_header_nritems(leaf);
|
|
if (nritems == 0)
|
|
return 1;
|
|
if (path->slots[0] == nritems)
|
|
path->slots[0]--;
|
|
|
|
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
|
|
if (found_key.objectid < min_objectid)
|
|
break;
|
|
if (found_key.type == type)
|
|
return 0;
|
|
if (found_key.objectid == min_objectid &&
|
|
found_key.type < type)
|
|
break;
|
|
}
|
|
return 1;
|
|
}
|