return 0;
}
+static struct rb_node *tree_insert(struct rb_root *root,
+ struct subvol_info *si,
+ enum subvol_search_type type)
+{
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
+ struct subvol_info *entry;
+ __s64 comp;
+
+ while (*p) {
+ parent = *p;
+ if (type == subvol_search_by_received_uuid) {
+ entry = rb_entry(parent, struct subvol_info,
+ rb_received_node);
+
+ comp = memcmp(entry->received_uuid, si->received_uuid,
+ BTRFS_UUID_SIZE);
+ if (!comp) {
+ if (entry->stransid < si->stransid)
+ comp = -1;
+ else if (entry->stransid > si->stransid)
+ comp = 1;
+ else
+ comp = 0;
+ }
+ } else if (type == subvol_search_by_uuid) {
+ entry = rb_entry(parent, struct subvol_info,
+ rb_local_node);
+ comp = memcmp(entry->uuid, si->uuid, BTRFS_UUID_SIZE);
+ } else if (type == subvol_search_by_root_id) {
+ entry = rb_entry(parent, struct subvol_info,
+ rb_root_id_node);
+ comp = entry->root_id - si->root_id;
+ } else if (type == subvol_search_by_path) {
+ entry = rb_entry(parent, struct subvol_info,
+ rb_path_node);
+ comp = strcmp(entry->path, si->path);
+ } else {
+ BUG();
+ }
+
+ if (comp < 0)
+ p = &(*p)->rb_left;
+ else if (comp > 0)
+ p = &(*p)->rb_right;
+ else
+ return parent;
+ }
+
+ if (type == subvol_search_by_received_uuid) {
+ rb_link_node(&si->rb_received_node, parent, p);
+ rb_insert_color(&si->rb_received_node, root);
+ } else if (type == subvol_search_by_uuid) {
+ rb_link_node(&si->rb_local_node, parent, p);
+ rb_insert_color(&si->rb_local_node, root);
+ } else if (type == subvol_search_by_root_id) {
+ rb_link_node(&si->rb_root_id_node, parent, p);
+ rb_insert_color(&si->rb_root_id_node, root);
+ } else if (type == subvol_search_by_path) {
+ rb_link_node(&si->rb_path_node, parent, p);
+ rb_insert_color(&si->rb_path_node, root);
+ }
+ return NULL;
+}
+
int btrfs_subvolid_resolve(int fd, char *path, size_t path_len, u64 subvol_id)
{
if (path_len < 1)
return 0;
}
+static int count_bytes(void *buf, int len, char b)
+{
+ int cnt = 0;
+ int i;
+
+ for (i = 0; i < len; i++) {
+ if (((char *)buf)[i] == b)
+ cnt++;
+ }
+ return cnt;
+}
+
void subvol_uuid_search_add(struct subvol_uuid_search *s,
struct subvol_info *si)
{
- if (si) {
- free(si->path);
- free(si);
+ int cnt;
+
+ tree_insert(&s->root_id_subvols, si, subvol_search_by_root_id);
+ tree_insert(&s->path_subvols, si, subvol_search_by_path);
+
+ cnt = count_bytes(si->uuid, BTRFS_UUID_SIZE, 0);
+ if (cnt != BTRFS_UUID_SIZE)
+ tree_insert(&s->local_subvols, si, subvol_search_by_uuid);
+ cnt = count_bytes(si->received_uuid, BTRFS_UUID_SIZE, 0);
+ if (cnt != BTRFS_UUID_SIZE)
+ tree_insert(&s->received_subvols, si,
+ subvol_search_by_received_uuid);
+}
+
+static struct subvol_info *tree_search(struct rb_root *root,
+ u64 root_id, const u8 *uuid,
+ u64 stransid, const char *path,
+ enum subvol_search_type type)
+{
+ struct rb_node *n = root->rb_node;
+ struct subvol_info *entry;
+ __s64 comp;
+
+ while (n) {
+ if (type == subvol_search_by_received_uuid) {
+ entry = rb_entry(n, struct subvol_info,
+ rb_received_node);
+ comp = memcmp(entry->received_uuid, uuid,
+ BTRFS_UUID_SIZE);
+ if (!comp) {
+ if (entry->stransid < stransid)
+ comp = -1;
+ else if (entry->stransid > stransid)
+ comp = 1;
+ else
+ comp = 0;
+ }
+ } else if (type == subvol_search_by_uuid) {
+ entry = rb_entry(n, struct subvol_info, rb_local_node);
+ comp = memcmp(entry->uuid, uuid, BTRFS_UUID_SIZE);
+ } else if (type == subvol_search_by_root_id) {
+ entry = rb_entry(n, struct subvol_info,
+ rb_root_id_node);
+ comp = entry->root_id - root_id;
+ } else if (type == subvol_search_by_path) {
+ entry = rb_entry(n, struct subvol_info, rb_path_node);
+ comp = strcmp(entry->path, path);
+ } else {
+ BUG();
+ }
+ if (comp < 0)
+ n = n->rb_left;
+ else if (comp > 0)
+ n = n->rb_right;
+ else
+ return entry;
}
+ return NULL;
+}
+
+/*
+ * this function will be only called if kernel dosen't support uuid tree.
+ */
+static struct subvol_info *subvol_uuid_search_old(struct subvol_uuid_search *s,
+ u64 root_id, const u8 *uuid, u64 transid,
+ const char *path,
+ enum subvol_search_type type)
+{
+ struct rb_root *root;
+ if (type == subvol_search_by_received_uuid)
+ root = &s->received_subvols;
+ else if (type == subvol_search_by_uuid)
+ root = &s->local_subvols;
+ else if (type == subvol_search_by_root_id)
+ root = &s->root_id_subvols;
+ else if (type == subvol_search_by_path)
+ root = &s->path_subvols;
+ else
+ return NULL;
+ return tree_search(root, root_id, uuid, transid, path, type);
}
struct subvol_info *subvol_uuid_search(struct subvol_uuid_search *s,
struct btrfs_root_item root_item;
struct subvol_info *info = NULL;
+ if (!s->uuid_tree_existed)
+ return subvol_uuid_search_old(s, root_id, uuid, transid,
+ path, type);
switch (type) {
case subvol_search_by_received_uuid:
ret = btrfs_lookup_uuid_received_subvol_item(s->mnt_fd, uuid,
return info;
}
+static int is_uuid_tree_supported(int fd)
+{
+ int ret;
+ struct btrfs_ioctl_search_args args;
+ struct btrfs_ioctl_search_key *sk = &args.key;
+
+ memset(&args, 0, sizeof(args));
+
+ sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
+
+ sk->min_objectid = BTRFS_UUID_TREE_OBJECTID;
+ sk->max_objectid = BTRFS_UUID_TREE_OBJECTID;
+ sk->max_type = BTRFS_ROOT_ITEM_KEY;
+ sk->min_type = BTRFS_ROOT_ITEM_KEY;
+ sk->max_offset = (u64)-1;
+ sk->max_transid = (u64)-1;
+ sk->nr_items = 1;
+
+ ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+ if (ret < 0)
+ return ret;
+
+ /* the ioctl returns the number of item it found in nr_items */
+ if (sk->nr_items == 0)
+ return 0;
+
+ return 1;
+}
+
+/*
+ * this function is mainly used to read all root items
+ * it will be only used when we use older kernel which uuid
+ * tree is not supported yet
+ */
int subvol_uuid_search_init(int mnt_fd, struct subvol_uuid_search *s)
{
+ int ret;
+ struct btrfs_ioctl_search_args args;
+ struct btrfs_ioctl_search_key *sk = &args.key;
+ struct btrfs_ioctl_search_header *sh;
+ struct btrfs_root_item *root_item_ptr;
+ struct btrfs_root_item root_item;
+ struct subvol_info *si = NULL;
+ int root_item_valid = 0;
+ unsigned long off = 0;
+ int i;
+ int e;
+ char *path;
+
s->mnt_fd = mnt_fd;
- return 0;
+ s->root_id_subvols = RB_ROOT;
+ s->local_subvols = RB_ROOT;
+ s->received_subvols = RB_ROOT;
+ s->path_subvols = RB_ROOT;
+
+ ret = is_uuid_tree_supported(mnt_fd);
+ if (ret < 0) {
+ fprintf(stderr,
+ "ERROR: check if we support uuid tree fails- %s\n",
+ strerror(errno));
+ return ret;
+ } else if (ret) {
+ /* uuid tree is supported */
+ s->uuid_tree_existed = 1;
+ return 0;
+ }
+ memset(&args, 0, sizeof(args));
+
+ sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
+
+ sk->max_objectid = (u64)-1;
+ sk->max_offset = (u64)-1;
+ sk->max_transid = (u64)-1;
+ sk->min_type = BTRFS_ROOT_ITEM_KEY;
+ sk->max_type = BTRFS_ROOT_BACKREF_KEY;
+ sk->nr_items = 4096;
+
+ while (1) {
+ ret = ioctl(mnt_fd, BTRFS_IOC_TREE_SEARCH, &args);
+ e = errno;
+ if (ret < 0) {
+ fprintf(stderr, "ERROR: can't perform the search- %s\n",
+ strerror(e));
+ return ret;
+ }
+ if (sk->nr_items == 0)
+ break;
+
+ off = 0;
+
+ for (i = 0; i < sk->nr_items; i++) {
+ sh = (struct btrfs_ioctl_search_header *)(args.buf +
+ off);
+ off += sizeof(*sh);
+
+ if ((sh->objectid != 5 &&
+ sh->objectid < BTRFS_FIRST_FREE_OBJECTID) ||
+ sh->objectid > BTRFS_LAST_FREE_OBJECTID)
+ goto skip;
+
+ if (sh->type == BTRFS_ROOT_ITEM_KEY) {
+ /* older kernels don't have uuids+times */
+ if (sh->len < sizeof(root_item)) {
+ root_item_valid = 0;
+ goto skip;
+ }
+ root_item_ptr = (struct btrfs_root_item *)
+ (args.buf + off);
+ memcpy(&root_item, root_item_ptr,
+ sizeof(root_item));
+ root_item_valid = 1;
+ } else if (sh->type == BTRFS_ROOT_BACKREF_KEY ||
+ root_item_valid) {
+ if (!root_item_valid)
+ goto skip;
+
+ path = btrfs_list_path_for_root(mnt_fd,
+ sh->objectid);
+ if (!path)
+ path = strdup("");
+ if (IS_ERR(path)) {
+ ret = PTR_ERR(path);
+ fprintf(stderr, "ERROR: unable to "
+ "resolve path "
+ "for root %llu\n",
+ sh->objectid);
+ goto out;
+ }
+
+ si = calloc(1, sizeof(*si));
+ si->root_id = sh->objectid;
+ memcpy(si->uuid, root_item.uuid,
+ BTRFS_UUID_SIZE);
+ memcpy(si->parent_uuid, root_item.parent_uuid,
+ BTRFS_UUID_SIZE);
+ memcpy(si->received_uuid,
+ root_item.received_uuid,
+ BTRFS_UUID_SIZE);
+ si->ctransid = btrfs_root_ctransid(&root_item);
+ si->otransid = btrfs_root_otransid(&root_item);
+ si->stransid = btrfs_root_stransid(&root_item);
+ si->rtransid = btrfs_root_rtransid(&root_item);
+ si->path = path;
+ subvol_uuid_search_add(s, si);
+ root_item_valid = 0;
+ } else {
+ goto skip;
+ }
+
+skip:
+ off += sh->len;
+
+ /*
+ * record the mins in sk so we can make sure the
+ * next search doesn't repeat this root
+ */
+ sk->min_objectid = sh->objectid;
+ sk->min_offset = sh->offset;
+ sk->min_type = sh->type;
+ }
+ sk->nr_items = 4096;
+ if (sk->min_offset < (u64)-1)
+ sk->min_offset++;
+ else if (sk->min_objectid < (u64)-1) {
+ sk->min_objectid++;
+ sk->min_offset = 0;
+ sk->min_type = 0;
+ } else
+ break;
+ }
+
+out:
+ return ret;
}
void subvol_uuid_search_finit(struct subvol_uuid_search *s)
{
+ struct rb_root *root = &s->root_id_subvols;
+ struct rb_node *node;
+
+ if (!s->uuid_tree_existed)
+ return;
+
+ while ((node = rb_first(root))) {
+ struct subvol_info *entry =
+ rb_entry(node, struct subvol_info, rb_root_id_node);
+
+ free(entry->path);
+ rb_erase(node, root);
+ free(entry);
+ }
+
+ s->root_id_subvols = RB_ROOT;
+ s->local_subvols = RB_ROOT;
+ s->received_subvols = RB_ROOT;
+ s->path_subvols = RB_ROOT;
}
char *path_cat(const char *p1, const char *p2)