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531 lines
14 KiB
531 lines
14 KiB
// 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 "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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|
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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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|
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len = btrfs_item_size_nr(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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memset(&item->generation_v2, 0, |
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sizeof(*item) - offsetof(struct btrfs_root_item, |
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generation_v2)); |
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|
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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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/* |
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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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|
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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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|
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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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|
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l = path->nodes[0]; |
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slot = path->slots[0]; |
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|
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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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|
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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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|
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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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/* |
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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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|
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path = btrfs_alloc_path(); |
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if (!path) |
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return -ENOMEM; |
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|
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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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|
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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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|
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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_nr(l, slot); |
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|
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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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|
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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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/* |
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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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|
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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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|
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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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|
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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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|
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path = btrfs_alloc_path(); |
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if (!path) |
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return -ENOMEM; |
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|
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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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|
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while (1) { |
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u64 root_objectid; |
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|
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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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|
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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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|
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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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|
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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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|
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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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|
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btrfs_release_path(path); |
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|
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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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|
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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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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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|
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btrfs_free_path(path); |
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return err; |
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} |
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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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|
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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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|
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BUG_ON(ret != 0); |
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|
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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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|
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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, const char *name, |
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int name_len) |
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|
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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 err = 0; |
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int ret; |
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|
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path = btrfs_alloc_path(); |
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if (!path) |
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return -ENOMEM; |
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|
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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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BUG_ON(ret < 0); |
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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, ptr, name_len)) { |
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err = -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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err = ret; |
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goto out; |
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} |
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} else |
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err = -ENOENT; |
|
|
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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 err; |
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} |
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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, const char *name, |
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int name_len) |
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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, 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; |
|
key.type = BTRFS_ROOT_REF_KEY; |
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key.offset = root_id; |
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goto again; |
|
} |
|
|
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btrfs_free_path(path); |
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return 0; |
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} |
|
|
|
/* |
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* Old btrfs forgets to init root_item->flags and root_item->byte_limit |
|
* for subvolumes. To work around this problem, we steal a bit from |
|
* root_item->inode_item->flags, and use it to indicate if those fields |
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* have been properly initialized. |
|
*/ |
|
void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item) |
|
{ |
|
u64 inode_flags = btrfs_stack_inode_flags(&root_item->inode); |
|
|
|
if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) { |
|
inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT; |
|
btrfs_set_stack_inode_flags(&root_item->inode, inode_flags); |
|
btrfs_set_root_flags(root_item, 0); |
|
btrfs_set_root_limit(root_item, 0); |
|
} |
|
} |
|
|
|
void btrfs_update_root_times(struct btrfs_trans_handle *trans, |
|
struct btrfs_root *root) |
|
{ |
|
struct btrfs_root_item *item = &root->root_item; |
|
struct timespec64 ct; |
|
|
|
ktime_get_real_ts64(&ct); |
|
spin_lock(&root->root_item_lock); |
|
btrfs_set_root_ctransid(item, trans->transid); |
|
btrfs_set_stack_timespec_sec(&item->ctime, ct.tv_sec); |
|
btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec); |
|
spin_unlock(&root->root_item_lock); |
|
} |
|
|
|
/* |
|
* btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation |
|
* root: the root of the parent directory |
|
* rsv: block reservation |
|
* items: the number of items that we need do reservation |
|
* use_global_rsv: allow fallback to the global block reservation |
|
* |
|
* This function is used to reserve the space for snapshot/subvolume |
|
* creation and deletion. Those operations are different with the |
|
* common file/directory operations, they change two fs/file trees |
|
* and root tree, the number of items that the qgroup reserves is |
|
* different with the free space reservation. So we can not use |
|
* the space reservation mechanism in start_transaction(). |
|
*/ |
|
int btrfs_subvolume_reserve_metadata(struct btrfs_root *root, |
|
struct btrfs_block_rsv *rsv, int items, |
|
bool use_global_rsv) |
|
{ |
|
u64 qgroup_num_bytes = 0; |
|
u64 num_bytes; |
|
int ret; |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; |
|
|
|
if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) { |
|
/* One for parent inode, two for dir entries */ |
|
qgroup_num_bytes = 3 * fs_info->nodesize; |
|
ret = btrfs_qgroup_reserve_meta_prealloc(root, |
|
qgroup_num_bytes, true); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
num_bytes = btrfs_calc_insert_metadata_size(fs_info, items); |
|
rsv->space_info = btrfs_find_space_info(fs_info, |
|
BTRFS_BLOCK_GROUP_METADATA); |
|
ret = btrfs_block_rsv_add(root, rsv, num_bytes, |
|
BTRFS_RESERVE_FLUSH_ALL); |
|
|
|
if (ret == -ENOSPC && use_global_rsv) |
|
ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes, true); |
|
|
|
if (ret && qgroup_num_bytes) |
|
btrfs_qgroup_free_meta_prealloc(root, qgroup_num_bytes); |
|
|
|
if (!ret) { |
|
spin_lock(&rsv->lock); |
|
rsv->qgroup_rsv_reserved += qgroup_num_bytes; |
|
spin_unlock(&rsv->lock); |
|
} |
|
return ret; |
|
} |
|
|
|
void btrfs_subvolume_release_metadata(struct btrfs_root *root, |
|
struct btrfs_block_rsv *rsv) |
|
{ |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
u64 qgroup_to_release; |
|
|
|
btrfs_block_rsv_release(fs_info, rsv, (u64)-1, &qgroup_to_release); |
|
btrfs_qgroup_convert_reserved_meta(root, qgroup_to_release); |
|
}
|
|
|