* Boston, MA 021110-1307, USA.
*/
+#include <unistd.h>
+#include <fcntl.h>
#include <sys/ioctl.h>
+#include <uuid/uuid.h>
#include "ctree.h"
#include "send-utils.h"
#include "ioctl.h"
#include "btrfs-list.h"
+static int btrfs_subvolid_resolve_sub(int fd, char *path, size_t *path_len,
+ u64 subvol_id);
+
+static int btrfs_get_root_id_by_sub_path(int mnt_fd, const char *sub_path,
+ u64 *root_id)
+{
+ int ret;
+ int subvol_fd;
+
+ subvol_fd = openat(mnt_fd, sub_path, O_RDONLY);
+ if (subvol_fd < 0) {
+ ret = -errno;
+ fprintf(stderr, "ERROR: open %s failed. %s\n", sub_path,
+ strerror(-ret));
+ return ret;
+ }
+
+ ret = btrfs_list_get_path_rootid(subvol_fd, root_id);
+ close(subvol_fd);
+ return ret;
+}
+
+static int btrfs_read_root_item_raw(int mnt_fd, u64 root_id, size_t buf_len,
+ u32 *read_len, void *buf)
+{
+ int ret;
+ struct btrfs_ioctl_search_args args;
+ struct btrfs_ioctl_search_key *sk = &args.key;
+ struct btrfs_ioctl_search_header *sh;
+ unsigned long off = 0;
+ int found = 0;
+ int i;
+
+ *read_len = 0;
+ memset(&args, 0, sizeof(args));
+
+ sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
+
+ /*
+ * there may be more than one ROOT_ITEM key if there are
+ * snapshots pending deletion, we have to loop through
+ * them.
+ */
+ sk->min_objectid = root_id;
+ sk->max_objectid = root_id;
+ 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 = 4096;
+
+ while (1) {
+ ret = ioctl(mnt_fd, BTRFS_IOC_TREE_SEARCH, &args);
+ if (ret < 0) {
+ fprintf(stderr,
+ "ERROR: can't perform the search - %s\n",
+ strerror(errno));
+ return 0;
+ }
+ /* the ioctl returns the number of item it found in nr_items */
+ if (sk->nr_items == 0)
+ break;
+
+ off = 0;
+ for (i = 0; i < sk->nr_items; i++) {
+ struct btrfs_root_item *item;
+ sh = (struct btrfs_ioctl_search_header *)(args.buf +
+ off);
+
+ off += sizeof(*sh);
+ item = (struct btrfs_root_item *)(args.buf + off);
+ off += sh->len;
+
+ sk->min_objectid = sh->objectid;
+ sk->min_type = sh->type;
+ sk->min_offset = sh->offset;
+
+ if (sh->objectid > root_id)
+ break;
+
+ if (sh->objectid == root_id &&
+ sh->type == BTRFS_ROOT_ITEM_KEY) {
+ if (sh->len > buf_len) {
+ /* btrfs-progs is too old for kernel */
+ fprintf(stderr,
+ "ERROR: buf for read_root_item_raw() is too small, get newer btrfs tools!\n");
+ return -EOVERFLOW;
+ }
+ memcpy(buf, item, sh->len);
+ *read_len = sh->len;
+ found = 1;
+ }
+ }
+ if (sk->min_offset < (u64)-1)
+ sk->min_offset++;
+ else
+ break;
+
+ if (sk->min_type != BTRFS_ROOT_ITEM_KEY ||
+ sk->min_objectid != root_id)
+ break;
+ }
+
+ return found ? 0 : -ENOENT;
+}
+
+/*
+ * Read a root item from the tree. In case we detect a root item smaller then
+ * sizeof(root_item), we know it's an old version of the root structure and
+ * initialize all new fields to zero. The same happens if we detect mismatching
+ * generation numbers as then we know the root was once mounted with an older
+ * kernel that was not aware of the root item structure change.
+ */
+static int btrfs_read_root_item(int mnt_fd, u64 root_id,
+ struct btrfs_root_item *item)
+{
+ int ret;
+ u32 read_len;
+
+ ret = btrfs_read_root_item_raw(mnt_fd, root_id, sizeof(*item),
+ &read_len, item);
+ if (ret)
+ return ret;
+
+ if (read_len < sizeof(*item) ||
+ btrfs_root_generation(item) != btrfs_root_generation_v2(item))
+ memset(&item->generation_v2, 0,
+ sizeof(*item) - offsetof(struct btrfs_root_item,
+ generation_v2));
+
+ return 0;
+}
+
+#ifdef BTRFS_COMPAT_SEND_NO_UUID_TREE
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 rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
struct subvol_info *entry;
__s64 comp;
- while(*p) {
+ while (*p) {
parent = *p;
if (type == subvol_search_by_received_uuid) {
entry = rb_entry(parent, struct subvol_info,
}
return NULL;
}
+#endif
+
+int btrfs_subvolid_resolve(int fd, char *path, size_t path_len, u64 subvol_id)
+{
+ if (path_len < 1)
+ return -EOVERFLOW;
+ path[0] = '\0';
+ path_len--;
+ path[path_len] = '\0';
+ return btrfs_subvolid_resolve_sub(fd, path, &path_len, subvol_id);
+}
+
+static int btrfs_subvolid_resolve_sub(int fd, char *path, size_t *path_len,
+ u64 subvol_id)
+{
+ int ret;
+ struct btrfs_ioctl_search_args search_arg;
+ struct btrfs_ioctl_ino_lookup_args ino_lookup_arg;
+ struct btrfs_ioctl_search_header *search_header;
+ struct btrfs_root_ref *backref_item;
+
+ if (subvol_id == BTRFS_FS_TREE_OBJECTID) {
+ if (*path_len < 1)
+ return -EOVERFLOW;
+ *path = '\0';
+ (*path_len)--;
+ return 0;
+ }
+
+ memset(&search_arg, 0, sizeof(search_arg));
+ search_arg.key.tree_id = BTRFS_ROOT_TREE_OBJECTID;
+ search_arg.key.min_objectid = subvol_id;
+ search_arg.key.max_objectid = subvol_id;
+ search_arg.key.min_type = BTRFS_ROOT_BACKREF_KEY;
+ search_arg.key.max_type = BTRFS_ROOT_BACKREF_KEY;
+ search_arg.key.max_offset = (u64)-1;
+ search_arg.key.max_transid = (u64)-1;
+ search_arg.key.nr_items = 1;
+ ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search_arg);
+ if (ret) {
+ fprintf(stderr,
+ "ioctl(BTRFS_IOC_TREE_SEARCH, subvol_id %llu) ret=%d, error: %s\n",
+ (unsigned long long)subvol_id, ret, strerror(errno));
+ return ret;
+ }
+
+ if (search_arg.key.nr_items < 1) {
+ fprintf(stderr,
+ "failed to lookup subvol_id %llu!\n",
+ (unsigned long long)subvol_id);
+ return -ENOENT;
+ }
+ search_header = (struct btrfs_ioctl_search_header *)search_arg.buf;
+ backref_item = (struct btrfs_root_ref *)(search_header + 1);
+ if (search_header->offset != BTRFS_FS_TREE_OBJECTID) {
+ int sub_ret;
+
+ sub_ret = btrfs_subvolid_resolve_sub(fd, path, path_len,
+ search_header->offset);
+ if (sub_ret)
+ return sub_ret;
+ if (*path_len < 1)
+ return -EOVERFLOW;
+ strcat(path, "/");
+ (*path_len)--;
+ }
+
+ if (btrfs_stack_root_ref_dirid(backref_item) !=
+ BTRFS_FIRST_FREE_OBJECTID) {
+ int len;
+
+ memset(&ino_lookup_arg, 0, sizeof(ino_lookup_arg));
+ ino_lookup_arg.treeid = search_header->offset;
+ ino_lookup_arg.objectid =
+ btrfs_stack_root_ref_dirid(backref_item);
+ ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &ino_lookup_arg);
+ if (ret) {
+ fprintf(stderr,
+ "ioctl(BTRFS_IOC_INO_LOOKUP) ret=%d, error: %s\n",
+ ret, strerror(errno));
+ return ret;
+ }
+
+ len = strlen(ino_lookup_arg.name);
+ if (*path_len < len)
+ return -EOVERFLOW;
+ strcat(path, ino_lookup_arg.name);
+ (*path_len) -= len;
+ }
+
+ if (*path_len < btrfs_stack_root_ref_name_len(backref_item))
+ return -EOVERFLOW;
+ strncat(path, (char *)(backref_item + 1),
+ btrfs_stack_root_ref_name_len(backref_item));
+ (*path_len) -= btrfs_stack_root_ref_name_len(backref_item);
+ return 0;
+}
+
+#ifdef BTRFS_COMPAT_SEND_NO_UUID_TREE
+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)
+{
+ 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 rb_node *n = root->rb_node;
struct subvol_info *entry;
__s64 comp;
- while(n) {
+ while (n) {
if (type == subvol_search_by_received_uuid) {
entry = rb_entry(n, struct subvol_info,
rb_received_node);
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);
+ 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);
return NULL;
}
-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)
-{
- 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);
-}
-
-struct subvol_info *subvol_uuid_search(struct subvol_uuid_search *s,
+/*
+ * 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)
return NULL;
return tree_search(root, root_id, uuid, transid, path, type);
}
+#else
+void subvol_uuid_search_add(struct subvol_uuid_search *s,
+ struct subvol_info *si)
+{
+ if (si) {
+ free(si->path);
+ free(si);
+ }
+}
+#endif
+struct subvol_info *subvol_uuid_search(struct subvol_uuid_search *s,
+ u64 root_id, const u8 *uuid, u64 transid,
+ const char *path,
+ enum subvol_search_type type)
+{
+ int ret = 0;
+ struct btrfs_root_item root_item;
+ struct subvol_info *info = NULL;
+
+#ifdef BTRFS_COMPAT_SEND_NO_UUID_TREE
+ if (!s->uuid_tree_existed)
+ return subvol_uuid_search_old(s, root_id, uuid, transid,
+ path, type);
+#endif
+ switch (type) {
+ case subvol_search_by_received_uuid:
+ ret = btrfs_lookup_uuid_received_subvol_item(s->mnt_fd, uuid,
+ &root_id);
+ break;
+ case subvol_search_by_uuid:
+ ret = btrfs_lookup_uuid_subvol_item(s->mnt_fd, uuid, &root_id);
+ break;
+ case subvol_search_by_root_id:
+ break;
+ case subvol_search_by_path:
+ ret = btrfs_get_root_id_by_sub_path(s->mnt_fd, path, &root_id);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ if (ret)
+ goto out;
+
+ ret = btrfs_read_root_item(s->mnt_fd, root_id, &root_item);
+ if (ret)
+ goto out;
+
+ info = calloc(1, sizeof(*info));
+ info->root_id = root_id;
+ memcpy(info->uuid, root_item.uuid, BTRFS_UUID_SIZE);
+ memcpy(info->received_uuid, root_item.received_uuid, BTRFS_UUID_SIZE);
+ memcpy(info->parent_uuid, root_item.parent_uuid, BTRFS_UUID_SIZE);
+ info->ctransid = btrfs_root_ctransid(&root_item);
+ info->otransid = btrfs_root_otransid(&root_item);
+ info->stransid = btrfs_root_stransid(&root_item);
+ info->rtransid = btrfs_root_rtransid(&root_item);
+ if (type == subvol_search_by_path) {
+ info->path = strdup(path);
+ } else {
+ info->path = malloc(BTRFS_PATH_NAME_MAX);
+ ret = btrfs_subvolid_resolve(s->mnt_fd, info->path,
+ BTRFS_PATH_NAME_MAX, root_id);
+ }
+
+out:
+ if (ret && info) {
+ free(info->path);
+ free(info);
+ info = NULL;
+ }
+
+ return info;
+}
+
+#ifdef BTRFS_COMPAT_SEND_NO_UUID_TREE
+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_key *sk = &args.key;
struct btrfs_ioctl_search_header *sh;
struct btrfs_root_item *root_item_ptr;
- struct btrfs_root_item root_item;
+ struct btrfs_root_item root_item = {};
struct subvol_info *si = NULL;
int root_item_valid = 0;
unsigned long off = 0;
int e;
char *path;
+ s->mnt_fd = mnt_fd;
+
+ 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_type = BTRFS_ROOT_BACKREF_KEY;
sk->nr_items = 4096;
- while(1) {
+ while (1) {
ret = ioctl(mnt_fd, BTRFS_IOC_TREE_SEARCH, &args);
e = errno;
if (ret < 0) {
if ((sh->objectid != 5 &&
sh->objectid < BTRFS_FIRST_FREE_OBJECTID) ||
- sh->objectid == BTRFS_FREE_INO_OBJECTID)
+ sh->objectid > BTRFS_LAST_FREE_OBJECTID)
goto skip;
if (sh->type == BTRFS_ROOT_ITEM_KEY) {
memcpy(&root_item, root_item_ptr,
sizeof(root_item));
root_item_valid = 1;
- } else if (sh->type == BTRFS_ROOT_BACKREF_KEY) {
+ } else if (sh->type == BTRFS_ROOT_BACKREF_KEY ||
+ root_item_valid) {
if (!root_item_valid)
goto skip;
- path = path_for_root(mnt_fd, sh->objectid);
+ path = btrfs_list_path_for_root(mnt_fd,
+ sh->objectid);
if (!path)
path = strdup("");
if (IS_ERR(path)) {
subvol_uuid_search_add(s, si);
root_item_valid = 0;
} else {
- root_item_valid = 0;
goto skip;
}
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;
+}
+#else
+int subvol_uuid_search_init(int mnt_fd, struct subvol_uuid_search *s)
+{
+ s->mnt_fd = mnt_fd;
+
+ return 0;
+}
+
+void subvol_uuid_search_finit(struct subvol_uuid_search *s)
+{
+}
+#endif
char *path_cat(const char *p1, const char *p2)
{
int p1_len = strlen(p1);
int p2_len = strlen(p2);
- char *new = malloc(p1_len + p2_len + 3);
+ char *new = malloc(p1_len + p2_len + 2);
if (p1_len && p1[p1_len - 1] == '/')
p1_len--;
return new;
}
-
char *path_cat3(const char *p1, const char *p2, const char *p3)
{
int p1_len = strlen(p1);
int p2_len = strlen(p2);
int p3_len = strlen(p3);
- char *new = malloc(p1_len + p2_len + p3_len + 4);
+ char *new = malloc(p1_len + p2_len + p3_len + 3);
if (p1_len && p1[p1_len - 1] == '/')
p1_len--;
sprintf(new, "%.*s/%.*s/%.*s", p1_len, p1, p2_len, p2, p3_len, p3);
return new;
}
-