[PATCH 3/5] btrfs-progs: image: Remove all existing dev extents for later rebuild

[Qu Wenruo]

This patch will remove all existing dev extents for later rebuild.

Signed-off-by: Qu Wenruo <w...@suse.com>
---
 image/main.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/image/main.c b/image/main.c
index 9060f6b1b665..707568f22e01 100644
--- a/image/main.c
+++ b/image/main.c
@@ -2210,6 +2210,70 @@ static void fixup_block_groups(struct btrfs_trans_handle 
*trans,
        }
 }
 
+static int remove_all_dev_extents(struct btrfs_trans_handle *trans,
+                                 struct btrfs_fs_info *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)
+{
+       int ret;
+
+       ret = remove_all_dev_extents(trans, fs_info);
+       if (ret < 0)
+               error("failed to remove all existing dev extents: %s",
+                       strerror(-ret));
+       return ret;
+}
+
 static int fixup_chunks_and_devices(struct btrfs_fs_info *fs_info,
                         struct mdrestore_struct *mdres, off_t dev_size)
 {
@@ -2227,6 +2291,10 @@ static int fixup_chunks_and_devices(struct btrfs_fs_info 
*fs_info,
        }
 
        fixup_block_groups(trans, fs_info);
+       ret = fixup_dev_extents(trans, fs_info);
+       if (ret < 0)
+               goto error;
+
        ret = fixup_device_size(trans, fs_info, mdres, dev_size);
        if (ret < 0)
                goto error;
-- 
2.19.2