96 lines
2.4 KiB
C
96 lines
2.4 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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#include "ctree.h"
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#include "block-group.h"
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/*
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* This will return the block group at or after bytenr if contains is 0, else
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* it will return the block group that contains the bytenr
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*/
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static struct btrfs_block_group_cache *block_group_cache_tree_search(
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struct btrfs_fs_info *info, u64 bytenr, int contains)
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{
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struct btrfs_block_group_cache *cache, *ret = NULL;
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struct rb_node *n;
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u64 end, start;
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spin_lock(&info->block_group_cache_lock);
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n = info->block_group_cache_tree.rb_node;
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while (n) {
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cache = rb_entry(n, struct btrfs_block_group_cache,
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cache_node);
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end = cache->key.objectid + cache->key.offset - 1;
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start = cache->key.objectid;
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if (bytenr < start) {
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if (!contains && (!ret || start < ret->key.objectid))
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ret = cache;
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n = n->rb_left;
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} else if (bytenr > start) {
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if (contains && bytenr <= end) {
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ret = cache;
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break;
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}
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n = n->rb_right;
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} else {
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ret = cache;
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break;
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}
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}
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if (ret) {
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btrfs_get_block_group(ret);
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if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
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info->first_logical_byte = ret->key.objectid;
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}
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spin_unlock(&info->block_group_cache_lock);
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return ret;
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}
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/*
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* Return the block group that starts at or after bytenr
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*/
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struct btrfs_block_group_cache *btrfs_lookup_first_block_group(
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struct btrfs_fs_info *info, u64 bytenr)
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{
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return block_group_cache_tree_search(info, bytenr, 0);
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}
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/*
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* Return the block group that contains the given bytenr
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*/
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struct btrfs_block_group_cache *btrfs_lookup_block_group(
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struct btrfs_fs_info *info, u64 bytenr)
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{
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return block_group_cache_tree_search(info, bytenr, 1);
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}
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struct btrfs_block_group_cache *btrfs_next_block_group(
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struct btrfs_block_group_cache *cache)
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{
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struct btrfs_fs_info *fs_info = cache->fs_info;
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struct rb_node *node;
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spin_lock(&fs_info->block_group_cache_lock);
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/* If our block group was removed, we need a full search. */
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if (RB_EMPTY_NODE(&cache->cache_node)) {
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const u64 next_bytenr = cache->key.objectid + cache->key.offset;
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spin_unlock(&fs_info->block_group_cache_lock);
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btrfs_put_block_group(cache);
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cache = btrfs_lookup_first_block_group(fs_info, next_bytenr); return cache;
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}
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node = rb_next(&cache->cache_node);
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btrfs_put_block_group(cache);
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if (node) {
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cache = rb_entry(node, struct btrfs_block_group_cache,
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cache_node);
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btrfs_get_block_group(cache);
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} else
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cache = NULL;
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spin_unlock(&fs_info->block_group_cache_lock);
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return cache;
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}
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