For multi-disk btrfs image recovered to single disk, the dev tree would
look like:
item 2 key (1 DEV_EXTENT 22020096)
dev extent chunk_tree 3
chunk_objectid 256 chunk_offset 22020096 length 8388608
item 3 key (1 DEV_EXTENT 30408704)
dev extent chunk_tree 3
chunk_objectid 256 chunk_offset 30408704 length 1073741824
item 4 key (1 DEV_EXTENT 1104150528)
dev extent chunk_tree 3
chunk_objectid 256 chunk_offset 1104150528 length 536870912
item 5 key (2 DEV_EXTENT 1048576)
dev extent chunk_tree 3
chunk_objectid 256 chunk_offset 22020096 length 8388608
item 6 key (2 DEV_EXTENT 9437184)
dev extent chunk_tree 3
chunk_objectid 256 chunk_offset 30408704 length 1073741824
item 7 key (2 DEV_EXTENT 1083179008)
dev extent chunk_tree 3
chunk_objectid 256 chunk_offset 1104150528 length 536870912
However in chunk tree, we only use devid 2, thus devid 1 is completely
garbage:
item 0 key (DEV_ITEMS DEV_ITEM 2)
item 1 key (FIRST_CHUNK_TREE CHUNK_ITEM 22020096) itemoff 16105
itemsize 80
length 8388608 owner 2 stripe_len 65536 type SYSTEM
num_stripes 1 sub_stripes 0
stripe 0 devid 2 offset 1048576
item 2 key (FIRST_CHUNK_TREE CHUNK_ITEM 30408704) itemoff 16025
itemsize 80
length 1073741824 owner 2 stripe_len 65536 type METADATA
num_stripes 1 sub_stripes 0
stripe 0 devid 2 offset 9437184
item 3 key (FIRST_CHUNK_TREE CHUNK_ITEM 1104150528) itemoff 15945
itemsize 80
length 1073741824 owner 2 stripe_len 65536 type DATA
num_stripes 1 sub_stripes 0
stripe 0 devid 2 offset 1083179008
To fix the problem, the most straight-forward way is to remove all
existing dev extents, and then re-fill correct dev extents from chunk.
So this patch just follow the straight-forward way to fix it, causing
the final dev extents layout to match with chunk tree, and make btrfs
check happy.
Signed-off-by: Qu Wenruo <w...@suse.com>
---
image/main.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 102 insertions(+)
diff --git a/image/main.c b/image/main.c
index 9187de34f34a..8f756689a1fa 100644
--- a/image/main.c
+++ b/image/main.c
@@ -2209,6 +2209,104 @@ static void fixup_block_groups(struct btrfs_fs_info
*fs_info)
}
}
+static int remove_all_dev_extents(struct btrfs_trans_handle *trans)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ struct btrfs_root *root = fs_info->dev_root;
+ struct btrfs_path path;
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ int slot;
+ int ret;
+
+ key.objectid = 1;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+ key.offset = 0;
+ btrfs_init_path(&path);
+
+ ret = btrfs_search_slot(trans, root, &key, &path, -1, 1);
+ if (ret < 0) {
+ error("failed to search dev tree: %s", strerror(-ret));
+ return ret;
+ }
+
+ while (1) {
+ slot = path.slots[0];
+ leaf = path.nodes[0];
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, &path);
+ if (ret < 0) {
+ error("failed to search dev tree: %s",
+ strerror(-ret));
+ goto out;
+ }
+ if (ret > 0) {
+ ret = 0;
+ goto out;
+ }
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.type != BTRFS_DEV_EXTENT_KEY)
+ break;
+ ret = btrfs_del_item(trans, root, &path);
+ if (ret < 0) {
+ error("failed to delete dev extent %llu, %llu: %s",
+ key.objectid, key.offset, strerror(-ret));
+ goto out;
+ }
+ }
+out:
+ btrfs_release_path(&path);
+ return ret;
+}
+
+static int fixup_dev_extents(struct btrfs_trans_handle *trans)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
+ struct btrfs_device *dev;
+ struct cache_extent *ce;
+ struct map_lookup *map;
+ u64 devid = btrfs_stack_device_id(&fs_info->super_copy->dev_item);
+ int i;
+ int ret;
+
+ ret = remove_all_dev_extents(trans);
+ if (ret < 0)
+ error("failed to remove all existing dev extents: %s",
+ strerror(-ret));
+
+ dev = btrfs_find_device(fs_info, devid, NULL, NULL);
+ if (!dev) {
+ error("faild to find devid %llu", devid);
+ return -ENODEV;
+ }
+
+ /* Rebuild all dev extents using chunk maps */
+ for (ce = search_cache_extent(&map_tree->cache_tree, 0); ce;
+ ce = next_cache_extent(ce)) {
+ u64 stripe_len;
+
+ map = container_of(ce, struct map_lookup, ce);
+ stripe_len = calc_stripe_length(map->type, ce->size,
+ map->num_stripes);
+ for (i = 0; i < map->num_stripes; i++) {
+ ret = btrfs_insert_dev_extent(trans, dev, ce->start,
+ stripe_len, map->stripes[i].physical);
+ if (ret < 0) {
+ error(
+ "failed to insert dev extent %llu %llu: %s",
+ devid, map->stripes[i].physical,
+ strerror(-ret));
+ goto out;
+ }
+ }
+ }
+out:
+ return ret;
+}
+
static int fixup_chunks_and_devices(struct btrfs_fs_info *fs_info,
struct mdrestore_struct *mdres, off_t dev_size)
{
@@ -2226,6 +2324,10 @@ static int fixup_chunks_and_devices(struct btrfs_fs_info
*fs_info,
}
fixup_block_groups(fs_info);
+ ret = fixup_dev_extents(trans);
+ if (ret < 0)
+ goto error;
+
ret = fixup_device_size(trans, mdres, dev_size);
if (ret < 0)
goto error;
--
2.19.2
