| /* |
| * Copyright (C) 2012 Alexander Block. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License v2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| |
| #include <sys/ioctl.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); |
| |
| 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; |
| } |
| |
| 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; |
| } |
| |
| 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; |
| } |
| |
| 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, |
| 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); |
| } |
| |
| 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; |
| |
| 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; |
| } |
| |
| /* |
| * It's safe to call this function even without the subvol_uuid_search_init() |
| * call before as long as the subvol_uuid_search structure is all-zero. |
| */ |
| void subvol_uuid_search_finit(struct subvol_uuid_search *s) |
| { |
| struct rb_root *root = &s->root_id_subvols; |
| struct rb_node *node; |
| |
| 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) |
| { |
| int p1_len = strlen(p1); |
| int p2_len = strlen(p2); |
| char *new = malloc(p1_len + p2_len + 2); |
| |
| if (p1_len && p1[p1_len - 1] == '/') |
| p1_len--; |
| if (p2_len && p2[p2_len - 1] == '/') |
| p2_len--; |
| sprintf(new, "%.*s/%.*s", p1_len, p1, p2_len, p2); |
| 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 + 3); |
| |
| if (p1_len && p1[p1_len - 1] == '/') |
| p1_len--; |
| if (p2_len && p2[p2_len - 1] == '/') |
| p2_len--; |
| if (p3_len && p3[p3_len - 1] == '/') |
| p3_len--; |
| sprintf(new, "%.*s/%.*s/%.*s", p1_len, p1, p2_len, p2, p3_len, p3); |
| return new; |
| } |
| |