Merge branch 'baserock/tiagogomes/btrfs2' into baserock/morphbaserock/morph

1 files changed, 461 insertions, 0 deletions

diff --git a/send-utils.c b/send-utils.c
new file mode 100644
index 0000000..bacd47e
--- /dev/null
+++ b/send-utils.c
@@ -0,0 +1,461 @@
+/*
+ * 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;
+}
+