Btrfs-progs: fix wrong leaf when checking the trees relationship

[platform/upstream/btrfs-progs.git] / btrfs-list.c

diff --git a/btrfs-list.c b/btrfs-list.c
index 44a73de..c53d016 100644 (file)
--- a/btrfs-list.c
+++ b/btrfs-list.c
@@ -183,6 +183,8 @@ static int add_root(struct root_lookup *root_lookup,
        ri->root_id = root_id;
        ri->ref_tree = ref_tree;
        strncpy(ri->name, name, name_len);
+       if (name_len > 0)
+               ri->name[name_len] = 0;
 
        ret = tree_insert(&root_lookup->root, root_id, ref_tree, &ri->rb_node);
        if (ret) {
@@ -200,7 +202,7 @@ static int add_root(struct root_lookup *root_lookup,
  * in by lookup_ino_path
  */
 static int resolve_root(struct root_lookup *rl, struct root_info *ri,
-                       u64 *root_id, u64 *parent_id, u64 *top_id, char **path)
+                       u64 *parent_id, u64 *top_id, char **path)
 {
        char *full_path = NULL;
        int len = 0;
@@ -254,7 +256,6 @@ static int resolve_root(struct root_lookup *rl, struct root_info *ri,
                }
        }
 
-       *root_id = ri->root_id;
        *path = full_path;
 
        return 0;
@@ -553,6 +554,60 @@ build:
        return full;
 }
 
+static int get_default_subvolid(int fd, u64 *default_id)
+{
+       struct btrfs_ioctl_search_args args;
+       struct btrfs_ioctl_search_key *sk = &args.key;
+       struct btrfs_ioctl_search_header *sh;
+       u64 found = 0;
+       int ret;
+
+       memset(&args, 0, sizeof(args));
+
+       /*
+        * search for a dir item with a name 'default' in the tree of
+        * tree roots, it should point us to a default root
+        */
+       sk->tree_id = 1;
+
+       /* don't worry about ancient format and request only one item */
+       sk->nr_items = 1;
+
+       sk->max_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID;
+       sk->min_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID;
+       sk->max_type = BTRFS_DIR_ITEM_KEY;
+       sk->min_type = BTRFS_DIR_ITEM_KEY;
+       sk->max_offset = (u64)-1;
+       sk->max_transid = (u64)-1;
+
+       ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+       if (ret < 0)
+               return ret;
+
+       /* the ioctl returns the number of items it found in nr_items */
+       if (sk->nr_items == 0)
+               goto out;
+
+       sh = (struct btrfs_ioctl_search_header *)args.buf;
+
+       if (sh->type == BTRFS_DIR_ITEM_KEY) {
+               struct btrfs_dir_item *di;
+               int name_len;
+               char *name;
+
+               di = (struct btrfs_dir_item *)(sh + 1);
+               name_len = btrfs_stack_dir_name_len(di);
+               name = (char *)(di + 1);
+
+               if (!strncmp("default", name, name_len))
+                       found = btrfs_disk_key_objectid(&di->location);
+       }
+
+out:
+       *default_id = found;
+       return 0;
+}
+
 static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
 {
        int ret;
@@ -664,12 +719,32 @@ static int __list_subvol_fill_paths(int fd, struct root_lookup *root_lookup)
        return 0;
 }
 
-int list_subvols(int fd, int print_parent)
+int list_subvols(int fd, int print_parent, int get_default)
 {
        struct root_lookup root_lookup;
        struct rb_node *n;
+       u64 default_id;
        int ret;
 
+       if (get_default) {
+               ret = get_default_subvolid(fd, &default_id);
+               if (ret) {
+                       fprintf(stderr, "ERROR: can't perform the search - %s\n",
+                               strerror(errno));
+                       return ret;
+               }
+               if (default_id == 0) {
+                       fprintf(stderr, "ERROR: 'default' dir item not found\n");
+                       return ret;
+               }
+
+               /* no need to resolve roots if FS_TREE is default */
+               if (default_id == BTRFS_FS_TREE_OBJECTID) {
+                       printf("ID 5 (FS_TREE)\n");
+                       return ret;
+               }
+       }
+
        ret = __list_subvol_search(fd, &root_lookup);
        if (ret) {
                fprintf(stderr, "ERROR: can't perform the search - %s\n",
@@ -692,23 +767,28 @@ int list_subvols(int fd, int print_parent)
        n = rb_last(&root_lookup.root);
        while (n) {
                struct root_info *entry;
-               u64 root_id;
                u64 level;
                u64 parent_id;
                char *path;
+
                entry = rb_entry(n, struct root_info, rb_node);
-               resolve_root(&root_lookup, entry, &root_id, &parent_id,
-                               &level, &path);
+               if (get_default && entry->root_id != default_id) {
+                       n = rb_prev(n);
+                       continue;
+               }
+
+               resolve_root(&root_lookup, entry, &parent_id, &level, &path);
                if (print_parent) {
                        printf("ID %llu parent %llu top level %llu path %s\n",
-                               (unsigned long long)root_id,
+                               (unsigned long long)entry->root_id,
                                (unsigned long long)parent_id,
                                (unsigned long long)level, path);
                } else {
                        printf("ID %llu top level %llu path %s\n",
-                               (unsigned long long)root_id,
+                               (unsigned long long)entry->root_id,
                                (unsigned long long)level, path);
                }
+
                free(path);
                n = rb_prev(n);
        }
@@ -914,17 +994,17 @@ char *path_for_root(int fd, u64 root)
        n = rb_last(&root_lookup.root);
        while (n) {
                struct root_info *entry;
-               u64 root_id;
                u64 parent_id;
                u64 level;
                char *path;
+
                entry = rb_entry(n, struct root_info, rb_node);
-               resolve_root(&root_lookup, entry, &root_id, &parent_id, &level,
-                               &path);
-               if (root_id == root)
+               resolve_root(&root_lookup, entry, &parent_id, &level, &path);
+               if (entry->root_id == root)
                        ret_path = path;
                else
                        free(path);
+
                n = rb_prev(n);
        }