diff mbox series

[v2,7/9] btrfs-progs: use a unified btrfs_make_subvol() implementation

Message ID ba9e53b1f4f17c50b0e57c1c9e5ca95e4199649c.1697754500.git.wqu@suse.com (mailing list archive)
State New, archived
Headers show
Series btrfs-progs: mkfs: introduce an experimental --subvol option | expand

Commit Message

Qu Wenruo Oct. 19, 2023, 10:30 p.m. UTC 
To create a subvolume there are several different helpers:

- create_subvol() from convert/main.c
  This relies one using an empty fs_root tree to copy its root item.
  But otherwise has a pretty well wrapper btrfs_ake_root_dir() helper to
  handle the inode item/ref insertion.

- create_data_reloc_tree() from mkfs/main.c
  This is already pretty usable for generic subvolume creation, the only
  bad code is the open-coded rootdir setup.

So here this patch introduce a better version with all the benefit from
the above implementations:

- Move btrfs_make_root_dir() into common/inode.[ch]

- Implement a unified btrfs_make_subvol() to replace above two implementations
  It would go with btrfs_create_root(), and btrfs_make_root_dir() to
  remove duplicated code, and return a btrfs_root pointer for caller
  to utilize.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 Makefile       |  1 +
 check/main.c   |  1 +
 common/inode.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++++
 common/inode.h | 16 +++++++++
 convert/main.c | 56 +++++++------------------------
 mkfs/common.c  | 39 ----------------------
 mkfs/common.h  |  2 --
 mkfs/main.c    | 79 ++++----------------------------------------
 8 files changed, 127 insertions(+), 157 deletions(-)
 create mode 100644 common/inode.c
 create mode 100644 common/inode.h
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index 273a1f0e3b7c..e3534be600fd 100644
--- a/Makefile
+++ b/Makefile
@@ -209,6 +209,7 @@  objects = \
 	common/fsfeatures.o	\
 	common/help.o	\
 	common/inject-error.o	\
+	common/inode.o		\
 	common/messages.o	\
 	common/open-utils.o	\
 	common/parse-utils.o	\
diff --git a/check/main.c b/check/main.c
index 4a88cc8f8708..8c884a9332f8 100644
--- a/check/main.c
+++ b/check/main.c
@@ -48,6 +48,7 @@ 
 #include "kernel-shared/file-item.h"
 #include "kernel-shared/tree-checker.h"
 #include "common/defs.h"
+#include "common/inode.h"
 #include "common/extent-cache.h"
 #include "common/internal.h"
 #include "common/messages.h"
diff --git a/common/inode.c b/common/inode.c
new file mode 100644
index 000000000000..712d50d6e1a9
--- /dev/null
+++ b/common/inode.c
@@ -0,0 +1,90 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <time.h>
+#include "kernel-shared/transaction.h"
+#include "kernel-shared/disk-io.h"
+#include "common/inode.h"
+#include "common/messages.h"
+
+int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
+			struct btrfs_root *root, u64 objectid)
+{
+	int ret;
+	struct btrfs_inode_item inode_item;
+	time_t now = time(NULL);
+
+	memset(&inode_item, 0, sizeof(inode_item));
+	btrfs_set_stack_inode_generation(&inode_item, trans->transid);
+	btrfs_set_stack_inode_size(&inode_item, 0);
+	btrfs_set_stack_inode_nlink(&inode_item, 1);
+	btrfs_set_stack_inode_nbytes(&inode_item, root->fs_info->nodesize);
+	btrfs_set_stack_inode_mode(&inode_item, S_IFDIR | 0755);
+	btrfs_set_stack_timespec_sec(&inode_item.atime, now);
+	btrfs_set_stack_timespec_nsec(&inode_item.atime, 0);
+	btrfs_set_stack_timespec_sec(&inode_item.ctime, now);
+	btrfs_set_stack_timespec_nsec(&inode_item.ctime, 0);
+	btrfs_set_stack_timespec_sec(&inode_item.mtime, now);
+	btrfs_set_stack_timespec_nsec(&inode_item.mtime, 0);
+	btrfs_set_stack_timespec_sec(&inode_item.otime, now);
+	btrfs_set_stack_timespec_nsec(&inode_item.otime, 0);
+
+	if (root->fs_info->tree_root == root)
+		btrfs_set_super_root_dir(root->fs_info->super_copy, objectid);
+
+	ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
+	if (ret)
+		goto error;
+
+	ret = btrfs_insert_inode_ref(trans, root, "..", 2, objectid, objectid, 0);
+	if (ret)
+		goto error;
+
+	btrfs_set_root_dirid(&root->root_item, objectid);
+	ret = 0;
+error:
+	return ret;
+}
+
+struct btrfs_root *btrfs_create_subvol(struct btrfs_trans_handle *trans,
+				       u64 objectid)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_root *root;
+	struct btrfs_key key;
+	int ret;
+
+	ret = btrfs_create_root(trans, objectid);
+	if (ret < 0) {
+		errno = -ret;
+		error("failed to create root %lld: %m", objectid);
+		return ERR_PTR(ret);
+	}
+	key.objectid = objectid;
+	key.type = BTRFS_ROOT_ITEM_KEY;
+	key.offset = 0;
+
+	root = btrfs_read_fs_root(fs_info, &key);
+	if (IS_ERR(root)) {
+		ret = PTR_ERR(root);
+		errno = -ret;
+		error("failed to read created subvolume %lld: %m", objectid);
+		return ERR_PTR(ret);
+	}
+
+	ret = btrfs_make_root_dir(trans, root, BTRFS_FIRST_FREE_OBJECTID);
+	if (ret < 0) {
+		errno = -ret;
+		error("failed to update root dir for root %llu",
+		      root->root_key.objectid);
+		return ERR_PTR(ret);
+	}
+	ret = btrfs_update_root(trans, trans->fs_info->tree_root,
+				&root->root_key, &root->root_item);
+	if (ret < 0) {
+		errno = -ret;
+		error("failed to update root %llu",
+		      root->root_key.objectid);
+		return ERR_PTR(ret);
+	}
+	return root;
+}
diff --git a/common/inode.h b/common/inode.h
new file mode 100644
index 000000000000..912caf1f7904
--- /dev/null
+++ b/common/inode.h
@@ -0,0 +1,16 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * This is the btrfs-progs specific inode related helpers, which is different
+ * from kernel code.
+ */
+#ifndef __BTRFS_INODE_H__
+#define __BTRFS_INODE_H__
+
+#include "kernel-shared/ctree.h"
+
+int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
+			struct btrfs_root *root, u64 objectid);
+struct btrfs_root *btrfs_create_subvol(struct btrfs_trans_handle *trans,
+				       u64 objectid);
+#endif
diff --git a/convert/main.c b/convert/main.c
index bcd310228fcd..991e45556c04 100644
--- a/convert/main.c
+++ b/convert/main.c
@@ -107,6 +107,7 @@ 
 #include "kernel-shared/ctree.h"
 #include "crypto/hash.h"
 #include "common/defs.h"
+#include "common/inode.h"
 #include "common/extent-cache.h"
 #include "common/internal.h"
 #include "common/cpu-utils.h"
@@ -916,44 +917,6 @@  out:
 	return ret;
 }
 
-static int create_subvol(struct btrfs_trans_handle *trans,
-			 struct btrfs_root *root, u64 root_objectid)
-{
-	struct extent_buffer *tmp;
-	struct btrfs_root *new_root;
-	struct btrfs_key key;
-	struct btrfs_root_item root_item;
-	int ret;
-
-	ret = btrfs_copy_root(trans, root, root->node, &tmp,
-			      root_objectid);
-	if (ret)
-		return ret;
-
-	memcpy(&root_item, &root->root_item, sizeof(root_item));
-	btrfs_set_root_bytenr(&root_item, tmp->start);
-	btrfs_set_root_level(&root_item, btrfs_header_level(tmp));
-	btrfs_set_root_generation(&root_item, trans->transid);
-	free_extent_buffer(tmp);
-
-	key.objectid = root_objectid;
-	key.type = BTRFS_ROOT_ITEM_KEY;
-	key.offset = trans->transid;
-	ret = btrfs_insert_root(trans, root->fs_info->tree_root,
-				&key, &root_item);
-
-	key.offset = (u64)-1;
-	new_root = btrfs_read_fs_root(root->fs_info, &key);
-	if (!new_root || IS_ERR(new_root)) {
-		error("unable to fs read root: %lu", PTR_ERR(new_root));
-		return PTR_ERR(new_root);
-	}
-
-	ret = btrfs_make_root_dir(trans, new_root, BTRFS_FIRST_FREE_OBJECTID);
-
-	return ret;
-}
-
 /*
  * New make_btrfs() has handle system and meta chunks quite well.
  * So only need to add remaining data chunks.
@@ -1013,6 +976,7 @@  static int make_convert_data_block_groups(struct btrfs_trans_handle *trans,
 static int init_btrfs(struct btrfs_mkfs_config *cfg, struct btrfs_root *root,
 			 struct btrfs_convert_context *cctx, u32 convert_flags)
 {
+	struct btrfs_root *created_root;
 	struct btrfs_key location;
 	struct btrfs_trans_handle *trans;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -1058,15 +1022,19 @@  static int init_btrfs(struct btrfs_mkfs_config *cfg, struct btrfs_root *root,
 			     BTRFS_FIRST_FREE_OBJECTID);
 
 	/* subvol for fs image file */
-	ret = create_subvol(trans, root, CONV_IMAGE_SUBVOL_OBJECTID);
-	if (ret < 0) {
-		error("failed to create subvolume image root: %d", ret);
+	created_root = btrfs_create_subvol(trans, CONV_IMAGE_SUBVOL_OBJECTID);
+	if (IS_ERR(created_root)) {
+		ret = PTR_ERR(created_root);
+		errno = -ret;
+		error("failed to create subvolume image root: %m");
 		goto err;
 	}
 	/* subvol for data relocation tree */
-	ret = create_subvol(trans, root, BTRFS_DATA_RELOC_TREE_OBJECTID);
-	if (ret < 0) {
-		error("failed to create DATA_RELOC root: %d", ret);
+	created_root = btrfs_create_subvol(trans, BTRFS_DATA_RELOC_TREE_OBJECTID);
+	if (IS_ERR(created_root)) {
+		ret = PTR_ERR(created_root);
+		errno = -ret;
+		error("failed to create DATA_RELOC root: %m");
 		goto err;
 	}
 
diff --git a/mkfs/common.c b/mkfs/common.c
index 5e56b33dda6d..de370a86fd97 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -757,45 +757,6 @@  out:
 	return ret;
 }
 
-int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
-			struct btrfs_root *root, u64 objectid)
-{
-	int ret;
-	struct btrfs_inode_item inode_item;
-	time_t now = time(NULL);
-
-	memset(&inode_item, 0, sizeof(inode_item));
-	btrfs_set_stack_inode_generation(&inode_item, trans->transid);
-	btrfs_set_stack_inode_size(&inode_item, 0);
-	btrfs_set_stack_inode_nlink(&inode_item, 1);
-	btrfs_set_stack_inode_nbytes(&inode_item, root->fs_info->nodesize);
-	btrfs_set_stack_inode_mode(&inode_item, S_IFDIR | 0755);
-	btrfs_set_stack_timespec_sec(&inode_item.atime, now);
-	btrfs_set_stack_timespec_nsec(&inode_item.atime, 0);
-	btrfs_set_stack_timespec_sec(&inode_item.ctime, now);
-	btrfs_set_stack_timespec_nsec(&inode_item.ctime, 0);
-	btrfs_set_stack_timespec_sec(&inode_item.mtime, now);
-	btrfs_set_stack_timespec_nsec(&inode_item.mtime, 0);
-	btrfs_set_stack_timespec_sec(&inode_item.otime, now);
-	btrfs_set_stack_timespec_nsec(&inode_item.otime, 0);
-
-	if (root->fs_info->tree_root == root)
-		btrfs_set_super_root_dir(root->fs_info->super_copy, objectid);
-
-	ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
-	if (ret)
-		goto error;
-
-	ret = btrfs_insert_inode_ref(trans, root, "..", 2, objectid, objectid, 0);
-	if (ret)
-		goto error;
-
-	btrfs_set_root_dirid(&root->root_item, objectid);
-	ret = 0;
-error:
-	return ret;
-}
-
 /*
  * Btrfs minimum size calculation is complicated, it should include at least:
  * 1. system group size
diff --git a/mkfs/common.h b/mkfs/common.h
index d9183c997bb2..d1c0eec80e1e 100644
--- a/mkfs/common.h
+++ b/mkfs/common.h
@@ -103,8 +103,6 @@  struct btrfs_mkfs_config {
 };
 
 int make_btrfs(int fd, struct btrfs_mkfs_config *cfg);
-int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
-			struct btrfs_root *root, u64 objectid);
 u64 btrfs_min_dev_size(u32 nodesize, int mixed, u64 meta_profile,
 		       u64 data_profile);
 int test_minimum_size(const char *file, u64 min_dev_size);
diff --git a/mkfs/main.c b/mkfs/main.c
index cf8922999b31..e5201fbc9c31 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -44,6 +44,7 @@ 
 #include "crypto/hash.h"
 #include "common/defs.h"
 #include "common/internal.h"
+#include "common/inode.h"
 #include "common/messages.h"
 #include "common/cpu-utils.h"
 #include "common/utils.h"
@@ -706,75 +707,6 @@  static void update_chunk_allocation(struct btrfs_fs_info *fs_info,
 	}
 }
 
-static int create_data_reloc_tree(struct btrfs_trans_handle *trans)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_inode_item *inode;
-	struct btrfs_root *root;
-	struct btrfs_path path = { 0 };
-	struct btrfs_key key = {
-		.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID,
-		.type = BTRFS_ROOT_ITEM_KEY,
-	};
-	u64 ino = BTRFS_FIRST_FREE_OBJECTID;
-	char *name = "..";
-	int ret;
-
-	root = btrfs_create_tree(trans, fs_info, &key);
-	if (IS_ERR(root)) {
-		ret = PTR_ERR(root);
-		goto out;
-	}
-	/* Update dirid as created tree has default dirid 0 */
-	btrfs_set_root_dirid(&root->root_item, ino);
-	ret = btrfs_update_root(trans, fs_info->tree_root, &root->root_key,
-				&root->root_item);
-	if (ret < 0)
-		goto out;
-
-	/* Cache this tree so it can be cleaned up at close_ctree() */
-	ret = rb_insert(&fs_info->fs_root_tree, &root->rb_node,
-			btrfs_fs_roots_compare_roots);
-	if (ret < 0)
-		goto out;
-
-	/* Insert INODE_ITEM */
-	ret = btrfs_new_inode(trans, root, ino, 0755 | S_IFDIR);
-	if (ret < 0)
-		goto out;
-
-	/* then INODE_REF */
-	ret = btrfs_insert_inode_ref(trans, root, name, strlen(name), ino, ino,
-				     0);
-	if (ret < 0)
-		goto out;
-
-	/* Update nlink of that inode item */
-	key.objectid = ino;
-	key.type = BTRFS_INODE_ITEM_KEY;
-	key.offset = 0;
-
-	ret = btrfs_search_slot(trans, root, &key, &path, 0, 1);
-	if (ret > 0) {
-		ret = -ENOENT;
-		btrfs_release_path(&path);
-		goto out;
-	}
-	if (ret < 0) {
-		btrfs_release_path(&path);
-		goto out;
-	}
-	inode = btrfs_item_ptr(path.nodes[0], path.slots[0],
-			       struct btrfs_inode_item);
-	btrfs_set_inode_nlink(path.nodes[0], inode, 1);
-	btrfs_mark_buffer_dirty(path.nodes[0]);
-	btrfs_release_path(&path);
-	return 0;
-out:
-	btrfs_abort_transaction(trans, ret);
-	return ret;
-}
-
 static int btrfs_uuid_tree_add(struct btrfs_trans_handle *trans, u8 *uuid,
 			       u8 type, u64 subvol_id_cpu)
 {
@@ -1139,6 +1071,7 @@  int BOX_MAIN(mkfs)(int argc, char **argv)
 {
 	char *file;
 	struct btrfs_root *root;
+	struct btrfs_root *data_reloc_root;
 	struct btrfs_fs_info *fs_info;
 	struct btrfs_trans_handle *trans;
 	struct open_ctree_args oca = { 0 };
@@ -1915,9 +1848,11 @@  raid_groups:
 		goto out;
 	}
 
-	ret = create_data_reloc_tree(trans);
-	if (ret) {
-		error("unable to create data reloc tree: %d", ret);
+	data_reloc_root = btrfs_create_subvol(trans, BTRFS_DATA_RELOC_TREE_OBJECTID);
+	if (IS_ERR(data_reloc_root)) {
+		ret = PTR_ERR(data_reloc_root);
+		errno = -ret;
+		error("unable to create data reloc tree: %m");
 		goto out;
 	}