Useful for later 'mkfs.btrfs --rootdir' shrink support.
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
---
mkfs/rootdir.c | 43 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
diff --git a/mkfs/rootdir.c b/mkfs/rootdir.c
index 99022afaa030..1ca37996a3b3 100644
--- a/mkfs/rootdir.c
+++ b/mkfs/rootdir.c
@@ -26,6 +26,7 @@
#include <fcntl.h>
#include <ftw.h>
#include "ctree.h"
+#include "volumes.h"
#include "internal.h"
#include "disk-io.h"
#include "messages.h"
@@ -778,3 +779,45 @@ u64 btrfs_mkfs_size_dir(const char *dir_name, u32 sectorsize, u64 min_dev_size,
total_size = data_chunk_size + meta_chunk_size + min_dev_size;
return total_size;
}
+
+/*
+ * Get the end position of the last device extent for given @devid;
+ * @size_ret is exclsuive (means it should be aligned to sectorsize)
+ */
+static int get_device_extent_end(struct btrfs_fs_info *fs_info,
+ u64 devid, u64 *size_ret)
+{
+ struct btrfs_root *dev_root = fs_info->dev_root;
+ struct btrfs_key key;
+ struct btrfs_path path;
+ struct btrfs_dev_extent *de;
+ int ret;
+
+ key.objectid = devid;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+ key.offset = (u64)-1;
+
+ btrfs_init_path(&path);
+ ret = btrfs_search_slot(NULL, dev_root, &key, &path, 0, 0);
+ /* Not really possible */
+ BUG_ON(ret == 0);
+
+ ret = btrfs_previous_item(dev_root, &path, devid, BTRFS_DEV_EXTENT_KEY);
+ if (ret < 0)
+ goto out;
+
+ /* No dev_extent at all, not really possible for rootdir case*/
+ if (ret > 0) {
+ *size_ret = 0;
+ ret = -EUCLEAN;
+ goto out;
+ }
+
+ btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
+ de = btrfs_item_ptr(path.nodes[0], path.slots[0],
+ struct btrfs_dev_extent);
+ *size_ret = key.offset + btrfs_dev_extent_length(path.nodes[0], de);
+out:
+ btrfs_release_path(&path);
+ return ret;
+}
--
2.14.2
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