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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * BTRFS filesystem implementation for U-Boot
- *
- * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
- */
- #include <malloc.h>
- #include "ctree.h"
- #include "btrfs.h"
- #include "disk-io.h"
- /*
- * Resolve the path of ino inside subvolume @root into @path_ret.
- *
- * @path_ret must be at least PATH_MAX size.
- */
- static int get_path_in_subvol(struct btrfs_root *root, u64 ino, char *path_ret)
- {
- struct btrfs_path path;
- struct btrfs_key key;
- char *tmp;
- u64 cur = ino;
- int ret = 0;
- tmp = malloc(PATH_MAX);
- if (!tmp)
- return -ENOMEM;
- tmp[0] = '\0';
- btrfs_init_path(&path);
- while (cur != BTRFS_FIRST_FREE_OBJECTID) {
- struct btrfs_inode_ref *iref;
- int name_len;
- btrfs_release_path(&path);
- key.objectid = cur;
- key.type = BTRFS_INODE_REF_KEY;
- key.offset = (u64)-1;
- ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
- /* Impossible */
- if (ret == 0)
- ret = -EUCLEAN;
- if (ret < 0)
- goto out;
- ret = btrfs_previous_item(root, &path, cur,
- BTRFS_INODE_REF_KEY);
- if (ret > 0)
- ret = -ENOENT;
- if (ret < 0)
- goto out;
- strncpy(tmp, path_ret, PATH_MAX);
- iref = btrfs_item_ptr(path.nodes[0], path.slots[0],
- struct btrfs_inode_ref);
- name_len = btrfs_inode_ref_name_len(path.nodes[0],
- iref);
- if (name_len > BTRFS_NAME_LEN) {
- ret = -ENAMETOOLONG;
- goto out;
- }
- read_extent_buffer(path.nodes[0], path_ret,
- (unsigned long)(iref + 1), name_len);
- path_ret[name_len] = '/';
- path_ret[name_len + 1] = '\0';
- strncat(path_ret, tmp, PATH_MAX);
- btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
- cur = key.offset;
- }
- out:
- btrfs_release_path(&path);
- free(tmp);
- return ret;
- }
- static int list_one_subvol(struct btrfs_root *root, char *path_ret)
- {
- struct btrfs_fs_info *fs_info = root->fs_info;
- struct btrfs_root *tree_root = fs_info->tree_root;
- struct btrfs_path path;
- struct btrfs_key key;
- char *tmp;
- u64 cur = root->root_key.objectid;
- int ret = 0;
- tmp = malloc(PATH_MAX);
- if (!tmp)
- return -ENOMEM;
- tmp[0] = '\0';
- path_ret[0] = '\0';
- btrfs_init_path(&path);
- while (cur != BTRFS_FS_TREE_OBJECTID) {
- struct btrfs_root_ref *rr;
- struct btrfs_key location;
- int name_len;
- u64 ino;
- key.objectid = cur;
- key.type = BTRFS_ROOT_BACKREF_KEY;
- key.offset = (u64)-1;
- btrfs_release_path(&path);
- ret = btrfs_search_slot(NULL, tree_root, &key, &path, 0, 0);
- if (ret == 0)
- ret = -EUCLEAN;
- if (ret < 0)
- goto out;
- ret = btrfs_previous_item(tree_root, &path, cur,
- BTRFS_ROOT_BACKREF_KEY);
- if (ret > 0)
- ret = -ENOENT;
- if (ret < 0)
- goto out;
- /* Get the subvolume name */
- rr = btrfs_item_ptr(path.nodes[0], path.slots[0],
- struct btrfs_root_ref);
- strncpy(tmp, path_ret, PATH_MAX);
- name_len = btrfs_root_ref_name_len(path.nodes[0], rr);
- if (name_len > BTRFS_NAME_LEN) {
- ret = -ENAMETOOLONG;
- goto out;
- }
- ino = btrfs_root_ref_dirid(path.nodes[0], rr);
- read_extent_buffer(path.nodes[0], path_ret,
- (unsigned long)(rr + 1), name_len);
- path_ret[name_len] = '/';
- path_ret[name_len + 1] = '\0';
- strncat(path_ret, tmp, PATH_MAX);
- /* Get the path inside the parent subvolume */
- btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
- location.objectid = key.offset;
- location.type = BTRFS_ROOT_ITEM_KEY;
- location.offset = (u64)-1;
- root = btrfs_read_fs_root(fs_info, &location);
- if (IS_ERR(root)) {
- ret = PTR_ERR(root);
- goto out;
- }
- ret = get_path_in_subvol(root, ino, path_ret);
- if (ret < 0)
- goto out;
- cur = key.offset;
- }
- /* Add the leading '/' */
- strncpy(tmp, path_ret, PATH_MAX);
- strncpy(path_ret, "/", PATH_MAX);
- strncat(path_ret, tmp, PATH_MAX);
- out:
- btrfs_release_path(&path);
- free(tmp);
- return ret;
- }
- static int list_subvolums(struct btrfs_fs_info *fs_info)
- {
- struct btrfs_root *tree_root = fs_info->tree_root;
- struct btrfs_root *root;
- struct btrfs_path path;
- struct btrfs_key key;
- char *result;
- int ret = 0;
- result = malloc(PATH_MAX);
- if (!result)
- return -ENOMEM;
- ret = list_one_subvol(fs_info->fs_root, result);
- if (ret < 0)
- goto out;
- root = fs_info->fs_root;
- printf("ID %llu gen %llu path %.*s\n",
- root->root_key.objectid, btrfs_root_generation(&root->root_item),
- PATH_MAX, result);
- key.objectid = BTRFS_FIRST_FREE_OBJECTID;
- key.type = BTRFS_ROOT_ITEM_KEY;
- key.offset = 0;
- btrfs_init_path(&path);
- ret = btrfs_search_slot(NULL, tree_root, &key, &path, 0, 0);
- if (ret < 0)
- goto out;
- while (1) {
- if (path.slots[0] >= btrfs_header_nritems(path.nodes[0]))
- goto next;
- btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
- if (key.objectid > BTRFS_LAST_FREE_OBJECTID)
- break;
- if (key.objectid < BTRFS_FIRST_FREE_OBJECTID ||
- key.type != BTRFS_ROOT_ITEM_KEY)
- goto next;
- key.offset = (u64)-1;
- root = btrfs_read_fs_root(fs_info, &key);
- if (IS_ERR(root)) {
- ret = PTR_ERR(root);
- if (ret == -ENOENT)
- goto next;
- }
- ret = list_one_subvol(root, result);
- if (ret < 0)
- goto out;
- printf("ID %llu gen %llu path %.*s\n",
- root->root_key.objectid,
- btrfs_root_generation(&root->root_item),
- PATH_MAX, result);
- next:
- ret = btrfs_next_item(tree_root, &path);
- if (ret < 0)
- goto out;
- if (ret > 0) {
- ret = 0;
- break;
- }
- }
- out:
- free(result);
- return ret;
- }
- void btrfs_list_subvols(void)
- {
- struct btrfs_fs_info *fs_info = current_fs_info;
- int ret;
- if (!fs_info)
- return;
- ret = list_subvolums(fs_info);
- if (ret < 0)
- error("failed to list subvolume: %d", ret);
- }
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