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aa5d3003dd
Move these out of ctree.h into orphan.h to cut down on code in ctree.h. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
550 lines
14 KiB
C
550 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*/
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#include <linux/err.h>
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#include <linux/uuid.h>
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#include "ctree.h"
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#include "fs.h"
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#include "messages.h"
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#include "transaction.h"
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#include "disk-io.h"
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#include "print-tree.h"
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#include "qgroup.h"
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#include "space-info.h"
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#include "accessors.h"
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#include "root-tree.h"
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#include "orphan.h"
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/*
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* Read a root item from the tree. In case we detect a root item smaller then
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* sizeof(root_item), we know it's an old version of the root structure and
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* initialize all new fields to zero. The same happens if we detect mismatching
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* generation numbers as then we know the root was once mounted with an older
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* kernel that was not aware of the root item structure change.
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*/
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static void btrfs_read_root_item(struct extent_buffer *eb, int slot,
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struct btrfs_root_item *item)
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{
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u32 len;
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int need_reset = 0;
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len = btrfs_item_size(eb, slot);
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read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot),
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min_t(u32, len, sizeof(*item)));
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if (len < sizeof(*item))
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need_reset = 1;
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if (!need_reset && btrfs_root_generation(item)
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!= btrfs_root_generation_v2(item)) {
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if (btrfs_root_generation_v2(item) != 0) {
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btrfs_warn(eb->fs_info,
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"mismatching generation and generation_v2 found in root item. This root was probably mounted with an older kernel. Resetting all new fields.");
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}
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need_reset = 1;
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}
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if (need_reset) {
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/* Clear all members from generation_v2 onwards. */
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memset_startat(item, 0, generation_v2);
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generate_random_guid(item->uuid);
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}
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}
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/*
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* btrfs_find_root - lookup the root by the key.
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* root: the root of the root tree
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* search_key: the key to search
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* path: the path we search
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* root_item: the root item of the tree we look for
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* root_key: the root key of the tree we look for
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*
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* If ->offset of 'search_key' is -1ULL, it means we are not sure the offset
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* of the search key, just lookup the root with the highest offset for a
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* given objectid.
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*
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* If we find something return 0, otherwise > 0, < 0 on error.
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*/
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int btrfs_find_root(struct btrfs_root *root, const struct btrfs_key *search_key,
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struct btrfs_path *path, struct btrfs_root_item *root_item,
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struct btrfs_key *root_key)
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{
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struct btrfs_key found_key;
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struct extent_buffer *l;
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int ret;
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int slot;
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ret = btrfs_search_slot(NULL, root, search_key, path, 0, 0);
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if (ret < 0)
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return ret;
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if (search_key->offset != -1ULL) { /* the search key is exact */
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if (ret > 0)
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goto out;
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} else {
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BUG_ON(ret == 0); /* Logical error */
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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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ret = 0;
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}
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l = path->nodes[0];
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slot = path->slots[0];
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btrfs_item_key_to_cpu(l, &found_key, slot);
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if (found_key.objectid != search_key->objectid ||
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found_key.type != BTRFS_ROOT_ITEM_KEY) {
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ret = 1;
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goto out;
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}
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if (root_item)
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btrfs_read_root_item(l, slot, root_item);
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if (root_key)
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memcpy(root_key, &found_key, sizeof(found_key));
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out:
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btrfs_release_path(path);
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return ret;
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}
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void btrfs_set_root_node(struct btrfs_root_item *item,
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struct extent_buffer *node)
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{
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btrfs_set_root_bytenr(item, node->start);
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btrfs_set_root_level(item, btrfs_header_level(node));
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btrfs_set_root_generation(item, btrfs_header_generation(node));
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}
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/*
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* copy the data in 'item' into the btree
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*/
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int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
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*root, struct btrfs_key *key, struct btrfs_root_item
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*item)
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{
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struct btrfs_fs_info *fs_info = root->fs_info;
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struct btrfs_path *path;
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struct extent_buffer *l;
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int ret;
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int slot;
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unsigned long ptr;
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u32 old_len;
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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ret = btrfs_search_slot(trans, root, key, path, 0, 1);
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if (ret < 0)
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goto out;
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if (ret > 0) {
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btrfs_crit(fs_info,
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"unable to find root key (%llu %u %llu) in tree %llu",
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key->objectid, key->type, key->offset,
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root->root_key.objectid);
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ret = -EUCLEAN;
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btrfs_abort_transaction(trans, ret);
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goto out;
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}
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l = path->nodes[0];
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slot = path->slots[0];
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ptr = btrfs_item_ptr_offset(l, slot);
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old_len = btrfs_item_size(l, slot);
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/*
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* If this is the first time we update the root item which originated
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* from an older kernel, we need to enlarge the item size to make room
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* for the added fields.
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*/
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if (old_len < sizeof(*item)) {
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btrfs_release_path(path);
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ret = btrfs_search_slot(trans, root, key, path,
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-1, 1);
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if (ret < 0) {
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btrfs_abort_transaction(trans, ret);
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goto out;
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}
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ret = btrfs_del_item(trans, root, path);
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if (ret < 0) {
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btrfs_abort_transaction(trans, ret);
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goto out;
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}
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btrfs_release_path(path);
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ret = btrfs_insert_empty_item(trans, root, path,
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key, sizeof(*item));
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if (ret < 0) {
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btrfs_abort_transaction(trans, ret);
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goto out;
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}
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l = path->nodes[0];
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slot = path->slots[0];
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ptr = btrfs_item_ptr_offset(l, slot);
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}
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/*
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* Update generation_v2 so at the next mount we know the new root
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* fields are valid.
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*/
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btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
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write_extent_buffer(l, item, ptr, sizeof(*item));
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btrfs_mark_buffer_dirty(path->nodes[0]);
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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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int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
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const struct btrfs_key *key, struct btrfs_root_item *item)
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{
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/*
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* Make sure generation v1 and v2 match. See update_root for details.
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*/
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btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
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return btrfs_insert_item(trans, root, key, item, sizeof(*item));
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}
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int btrfs_find_orphan_roots(struct btrfs_fs_info *fs_info)
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{
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struct btrfs_root *tree_root = fs_info->tree_root;
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struct extent_buffer *leaf;
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struct btrfs_path *path;
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struct btrfs_key key;
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struct btrfs_root *root;
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int err = 0;
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int ret;
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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key.objectid = BTRFS_ORPHAN_OBJECTID;
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key.type = BTRFS_ORPHAN_ITEM_KEY;
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key.offset = 0;
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while (1) {
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u64 root_objectid;
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ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
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if (ret < 0) {
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err = ret;
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break;
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}
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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(tree_root, path);
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if (ret < 0)
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err = ret;
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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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btrfs_release_path(path);
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if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
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key.type != BTRFS_ORPHAN_ITEM_KEY)
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break;
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root_objectid = key.offset;
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key.offset++;
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root = btrfs_get_fs_root(fs_info, root_objectid, false);
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err = PTR_ERR_OR_ZERO(root);
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if (err && err != -ENOENT) {
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break;
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} else if (err == -ENOENT) {
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struct btrfs_trans_handle *trans;
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btrfs_release_path(path);
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trans = btrfs_join_transaction(tree_root);
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if (IS_ERR(trans)) {
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err = PTR_ERR(trans);
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btrfs_handle_fs_error(fs_info, err,
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"Failed to start trans to delete orphan item");
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break;
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}
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err = btrfs_del_orphan_item(trans, tree_root,
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root_objectid);
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btrfs_end_transaction(trans);
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if (err) {
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btrfs_handle_fs_error(fs_info, err,
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"Failed to delete root orphan item");
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break;
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}
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continue;
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}
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WARN_ON(!test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state));
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if (btrfs_root_refs(&root->root_item) == 0) {
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struct btrfs_key drop_key;
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btrfs_disk_key_to_cpu(&drop_key, &root->root_item.drop_progress);
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/*
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* If we have a non-zero drop_progress then we know we
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* made it partly through deleting this snapshot, and
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* thus we need to make sure we block any balance from
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* happening until this snapshot is completely dropped.
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*/
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if (drop_key.objectid != 0 || drop_key.type != 0 ||
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drop_key.offset != 0) {
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set_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags);
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set_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state);
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}
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set_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
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btrfs_add_dead_root(root);
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}
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btrfs_put_root(root);
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}
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btrfs_free_path(path);
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return err;
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}
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/* drop the root item for 'key' from the tree root */
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int btrfs_del_root(struct btrfs_trans_handle *trans,
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const struct btrfs_key *key)
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{
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struct btrfs_root *root = trans->fs_info->tree_root;
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struct btrfs_path *path;
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int ret;
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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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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goto out;
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BUG_ON(ret != 0);
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ret = btrfs_del_item(trans, root, path);
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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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int btrfs_del_root_ref(struct btrfs_trans_handle *trans, u64 root_id,
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u64 ref_id, u64 dirid, u64 *sequence,
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const struct fscrypt_str *name)
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{
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struct btrfs_root *tree_root = trans->fs_info->tree_root;
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struct btrfs_path *path;
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struct btrfs_root_ref *ref;
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struct extent_buffer *leaf;
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struct btrfs_key key;
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unsigned long ptr;
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int ret;
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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key.objectid = root_id;
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key.type = BTRFS_ROOT_BACKREF_KEY;
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key.offset = ref_id;
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again:
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ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
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if (ret < 0) {
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goto out;
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} else if (ret == 0) {
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leaf = path->nodes[0];
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ref = btrfs_item_ptr(leaf, path->slots[0],
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struct btrfs_root_ref);
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ptr = (unsigned long)(ref + 1);
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if ((btrfs_root_ref_dirid(leaf, ref) != dirid) ||
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(btrfs_root_ref_name_len(leaf, ref) != name->len) ||
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memcmp_extent_buffer(leaf, name->name, ptr, name->len)) {
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ret = -ENOENT;
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goto out;
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}
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*sequence = btrfs_root_ref_sequence(leaf, ref);
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ret = btrfs_del_item(trans, tree_root, path);
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if (ret)
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goto out;
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} else {
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ret = -ENOENT;
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goto out;
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}
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if (key.type == BTRFS_ROOT_BACKREF_KEY) {
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btrfs_release_path(path);
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key.objectid = ref_id;
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key.type = BTRFS_ROOT_REF_KEY;
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key.offset = root_id;
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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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}
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/*
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* add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
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* or BTRFS_ROOT_BACKREF_KEY.
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*
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* The dirid, sequence, name and name_len refer to the directory entry
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* that is referencing the root.
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*
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* For a forward ref, the root_id is the id of the tree referencing
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* the root and ref_id is the id of the subvol or snapshot.
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*
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* For a back ref the root_id is the id of the subvol or snapshot and
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* ref_id is the id of the tree referencing it.
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*
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* Will return 0, -ENOMEM, or anything from the CoW path
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*/
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int btrfs_add_root_ref(struct btrfs_trans_handle *trans, u64 root_id,
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u64 ref_id, u64 dirid, u64 sequence,
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const struct fscrypt_str *name)
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{
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struct btrfs_root *tree_root = trans->fs_info->tree_root;
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struct btrfs_key key;
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int ret;
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struct btrfs_path *path;
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struct btrfs_root_ref *ref;
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struct extent_buffer *leaf;
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unsigned long ptr;
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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key.objectid = root_id;
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key.type = BTRFS_ROOT_BACKREF_KEY;
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key.offset = ref_id;
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again:
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ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
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sizeof(*ref) + name->len);
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if (ret) {
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btrfs_abort_transaction(trans, ret);
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btrfs_free_path(path);
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return ret;
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}
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leaf = path->nodes[0];
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ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
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btrfs_set_root_ref_dirid(leaf, ref, dirid);
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btrfs_set_root_ref_sequence(leaf, ref, sequence);
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btrfs_set_root_ref_name_len(leaf, ref, name->len);
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ptr = (unsigned long)(ref + 1);
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write_extent_buffer(leaf, name->name, ptr, name->len);
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btrfs_mark_buffer_dirty(leaf);
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if (key.type == BTRFS_ROOT_BACKREF_KEY) {
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btrfs_release_path(path);
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key.objectid = ref_id;
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key.type = BTRFS_ROOT_REF_KEY;
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key.offset = root_id;
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goto again;
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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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/*
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* Old btrfs forgets to init root_item->flags and root_item->byte_limit
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* for subvolumes. To work around this problem, we steal a bit from
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* root_item->inode_item->flags, and use it to indicate if those fields
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* have been properly initialized.
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*/
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void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item)
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{
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u64 inode_flags = btrfs_stack_inode_flags(&root_item->inode);
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if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) {
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inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT;
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btrfs_set_stack_inode_flags(&root_item->inode, inode_flags);
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btrfs_set_root_flags(root_item, 0);
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btrfs_set_root_limit(root_item, 0);
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}
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}
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void btrfs_update_root_times(struct btrfs_trans_handle *trans,
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struct btrfs_root *root)
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{
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struct btrfs_root_item *item = &root->root_item;
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struct timespec64 ct;
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ktime_get_real_ts64(&ct);
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spin_lock(&root->root_item_lock);
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btrfs_set_root_ctransid(item, trans->transid);
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btrfs_set_stack_timespec_sec(&item->ctime, ct.tv_sec);
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btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec);
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spin_unlock(&root->root_item_lock);
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}
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/*
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* btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
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* root: the root of the parent directory
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* rsv: block reservation
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* items: the number of items that we need do reservation
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* use_global_rsv: allow fallback to the global block reservation
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*
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* This function is used to reserve the space for snapshot/subvolume
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* creation and deletion. Those operations are different with the
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* common file/directory operations, they change two fs/file trees
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* and root tree, the number of items that the qgroup reserves is
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* different with the free space reservation. So we can not use
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* the space reservation mechanism in start_transaction().
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*/
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int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
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struct btrfs_block_rsv *rsv, int items,
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bool use_global_rsv)
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{
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u64 qgroup_num_bytes = 0;
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u64 num_bytes;
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int ret;
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struct btrfs_fs_info *fs_info = root->fs_info;
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struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
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if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
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/* One for parent inode, two for dir entries */
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qgroup_num_bytes = 3 * fs_info->nodesize;
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ret = btrfs_qgroup_reserve_meta_prealloc(root,
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qgroup_num_bytes, true,
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false);
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if (ret)
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return ret;
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}
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num_bytes = btrfs_calc_insert_metadata_size(fs_info, items);
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rsv->space_info = btrfs_find_space_info(fs_info,
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BTRFS_BLOCK_GROUP_METADATA);
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ret = btrfs_block_rsv_add(fs_info, rsv, num_bytes,
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BTRFS_RESERVE_FLUSH_ALL);
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if (ret == -ENOSPC && use_global_rsv)
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ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes, true);
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if (ret && qgroup_num_bytes)
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btrfs_qgroup_free_meta_prealloc(root, qgroup_num_bytes);
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if (!ret) {
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spin_lock(&rsv->lock);
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rsv->qgroup_rsv_reserved += qgroup_num_bytes;
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spin_unlock(&rsv->lock);
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}
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return ret;
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}
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void btrfs_subvolume_release_metadata(struct btrfs_root *root,
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struct btrfs_block_rsv *rsv)
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{
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struct btrfs_fs_info *fs_info = root->fs_info;
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u64 qgroup_to_release;
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btrfs_block_rsv_release(fs_info, rsv, (u64)-1, &qgroup_to_release);
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btrfs_qgroup_convert_reserved_meta(root, qgroup_to_release);
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}
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