This commit adds UUID tree lookup methods that make use of the search
ioctl. The code is based on the kernel code.
Signed-off-by: Stefan Behrens <sbehr...@giantdisaster.de>
---
Makefile | 5 +--
ctree.h | 5 +++
uuid-tree.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 112 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
index 398ef52..511ba6d 100644
--- a/Makefile
+++ b/Makefile
@@ -6,12 +6,13 @@ CFLAGS = -g -O1
objects = ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
root-tree.o dir-item.o file-item.o inode-item.o inode-map.o \
extent-cache.o extent_io.o volumes.o utils.o repair.o \
- qgroup.o raid6.o free-space-cache.o
+ qgroup.o raid6.o free-space-cache.o uuid-tree.o
cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \
cmds-inspect.o cmds-balance.o cmds-send.o cmds-receive.o \
cmds-quota.o cmds-qgroup.o cmds-replace.o cmds-check.o \
cmds-restore.o
-libbtrfs_objects = send-stream.o send-utils.o rbtree.o btrfs-list.o crc32c.o
+libbtrfs_objects = send-stream.o send-utils.o rbtree.o btrfs-list.o crc32c.o \
+ uuid-tree.o
libbtrfs_headers = send-stream.h send-utils.h send.h rbtree.h btrfs-list.h \
crc32c.h list.h kerncompat.h radix-tree.h extent-cache.h \
extent_io.h ioctl.h ctree.h
diff --git a/ctree.h b/ctree.h
index f959573..e4bca8f 100644
--- a/ctree.h
+++ b/ctree.h
@@ -2346,4 +2346,9 @@ struct btrfs_csum_item *btrfs_lookup_csum(struct
btrfs_trans_handle *trans,
int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_path *path,
u64 isize);
+
+/* uuid-tree.c */
+int btrfs_lookup_uuid_subvol_item(int fd, const u8 *uuid, u64 *subvol_id);
+int btrfs_lookup_uuid_received_subvol_item(int fd, const u8 *uuid,
+ u64 *subvol_id);
#endif
diff --git a/uuid-tree.c b/uuid-tree.c
new file mode 100644
index 0000000..3a4c48e
--- /dev/null
+++ b/uuid-tree.c
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) STRATO AG 2013. 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 <stdio.h>
+#include <stdlib.h>
+#include <uuid/uuid.h>
+#include <sys/ioctl.h>
+#include "ctree.h"
+#include "transaction.h"
+#include "disk-io.h"
+#include "print-tree.h"
+
+
+static void btrfs_uuid_to_key(const u8 *uuid, u64 *key_objectid,
+ u64 *key_offset)
+{
+ *key_objectid = get_unaligned_le64(uuid);
+ *key_offset = get_unaligned_le64(uuid + sizeof(u64));
+}
+
+
+/* return -ENOENT for !found, < 0 for errors, or 0 if an item was found */
+static int btrfs_uuid_tree_lookup_any(int fd, const u8 *uuid, u8 type,
+ u64 *subid)
+{
+ int ret;
+ u64 key_objectid = 0;
+ u64 key_offset;
+ struct btrfs_ioctl_search_args search_arg;
+ struct btrfs_ioctl_search_header *search_header;
+ u32 item_size;
+
+ btrfs_uuid_to_key(uuid, &key_objectid, &key_offset);
+
+ memset(&search_arg, 0, sizeof(search_arg));
+ search_arg.key.tree_id = BTRFS_UUID_TREE_OBJECTID;
+ search_arg.key.min_objectid = key_objectid;
+ search_arg.key.max_objectid = key_objectid;
+ search_arg.key.min_type = type;
+ search_arg.key.max_type = type;
+ search_arg.key.min_offset = key_offset;
+ search_arg.key.max_offset = key_offset;
+ search_arg.key.max_transid = (u64)-1;
+ search_arg.key.nr_items = 1;
+ ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search_arg);
+ if (ret < 0) {
+ fprintf(stderr,
+ "ioctl(BTRFS_IOC_TREE_SEARCH, uuid, key %016llx,
UUID_KEY, %016llx) ret=%d, error: %s\n",
+ (unsigned long long)key_objectid,
+ (unsigned long long)key_offset, ret, strerror(errno));
+ ret = -ENOENT;
+ goto out;
+ }
+
+ if (search_arg.key.nr_items < 1) {
+ ret = -ENOENT;
+ goto out;
+ }
+ search_header = (struct btrfs_ioctl_search_header *)(search_arg.buf);
+ item_size = search_header->len;
+ if ((item_size & (sizeof(u64) - 1)) || item_size == 0) {
+ printf("btrfs: uuid item with illegal size %lu!\n",
+ (unsigned long)item_size);
+ ret = -ENOENT;
+ goto out;
+ } else {
+ ret = 0;
+ }
+
+ /* return first stored id */
+ memcpy(subid, search_header + 1, sizeof(*subid));
+ *subid = le64_to_cpu(*subid);
+
+out:
+ return ret;
+}
+
+int btrfs_lookup_uuid_subvol_item(int fd, const u8 *uuid, u64 *subvol_id)
+{
+ return btrfs_uuid_tree_lookup_any(fd, uuid, BTRFS_UUID_KEY_SUBVOL,
+ subvol_id);
+}
+
+int btrfs_lookup_uuid_received_subvol_item(int fd, const u8 *uuid,
+ u64 *subvol_id)
+{
+ return btrfs_uuid_tree_lookup_any(fd, uuid,
+ BTRFS_UUID_KEY_RECEIVED_SUBVOL,
+ subvol_id);
+}
--
1.8.3
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