[v2,03/10] btrfs-progs: Add new btrfs_open_ctree_flags CHUNK_ONLY.

Commit Message

Qu Wenruo Jan. 19, 2015, 6:45 a.m. UTC

Add new flag CHUNK_ONLY and internal used only flag __RETURN_CHUNK.

CHUNK_ONLY will imply __RETURN_CHUNK, SUPPRESS_ERROR and PARTIAL, which
will allow the fs to be opened with only chunk tree OK.

This will improve the usability for btrfs-find-root.

Signed-off-by: Qu Wenruo <[e-mail]>
---
 disk-io.c | 6 +++++-
 disk-io.h | 9 +++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

Patch

diff --git a/disk-io.c b/disk-io.c
index f08f612..71ca31f 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -1167,7 +1167,7 @@  static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
 			   BTRFS_UUID_SIZE);
 
 	ret = btrfs_setup_all_roots(fs_info, root_tree_bytenr, flags);
-	if (ret)
+	if (ret && !(flags & __RETURN_CHUNK_ROOT))
 		goto out_chunk;
 
 	return fs_info;
@@ -1212,6 +1212,8 @@  struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr,
 	info = open_ctree_fs_info(filename, sb_bytenr, 0, flags);
 	if (!info)
 		return NULL;
+	if (flags & __RETURN_CHUNK_ROOT)
+		return info->chunk_root;
 	return info->fs_root;
 }
 
@@ -1222,6 +1224,8 @@  struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
 	info = __open_ctree_fd(fp, path, sb_bytenr, 0, flags);
 	if (!info)
 		return NULL;
+	if (flags & __RETURN_CHUNK_ROOT)
+		return info->chunk_root;
 	return info->fs_root;
 }
 
diff --git a/disk-io.h b/disk-io.h
index 90ede6b..2d23cc3 100644
--- a/disk-io.h
+++ b/disk-io.h
@@ -34,6 +34,15 @@  enum btrfs_open_ctree_flags {
 	OPEN_CTREE_NO_BLOCK_GROUPS	= (1 << 5),
 	OPEN_CTREE_EXCLUSIVE		= (1 << 6),
 	OPEN_CTREE_SUPPRESS_ERROR	= (1 << 7), /* Suppress csum error */
+	__RETURN_CHUNK_ROOT		= (1 << 8), /* Return chunk root */
+	OPEN_CTREE_CHUNK_ONLY		= OPEN_CTREE_PARTIAL +
+					  OPEN_CTREE_SUPPRESS_ERROR +
+					  __RETURN_CHUNK_ROOT,
+	/*
+	 * TODO: cleanup: Split the open_ctree_flags into more indepent
+	 * tree bits.
+	 * Like split PARTIAL into SKIP_CSUM/SKIP_EXTENT
+	 */
 };
 
 static inline u64 btrfs_sb_offset(int mirror)