From f1c24cd80dfd037407cdee85181646adca6dd5bb Mon Sep 17 00:00:00 2001 From: Alexander Block Date: Wed, 25 Jul 2012 23:08:25 +0200 Subject: Btrfs-progs: add btrfs send/receive commands Add user space commands for btrfs send/receive. Signed-off-by: Alexander Block Reviewed-by: David Sterba Reviewed-by: Arne Jansen Reviewed-by: Jan Schmidt Reviewed-by: Alex Lyakas --- send-utils.c | 337 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 337 insertions(+) create mode 100644 send-utils.c (limited to 'send-utils.c') diff --git a/send-utils.c b/send-utils.c new file mode 100644 index 0000000..059efd3 --- /dev/null +++ b/send-utils.c @@ -0,0 +1,337 @@ +/* + * 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 + +#include "ctree.h" +#include "send-utils.h" +#include "ioctl.h" + +/* btrfs-list.c */ +char *path_for_root(int fd, u64 root); + +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); + } + + 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); + } + 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_FREE_INO_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) { + if (!root_item_valid) + goto skip; + + path = 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 { + root_item_valid = 0; + 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; +} + + +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); + + 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 + 4); + + 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; +} + -- cgit v1.2.1