From 3c555beabfaa417ae8c156d54a39ee5eb87ea7ce Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 2 Jul 2024 17:06:25 +0930 Subject: [PATCH] btrfs-progs: introduce btrfs_make_subvolume() There are two different subvolume/data reloc tree creation routines: - create_subvol() from convert/main.c * calls btrfs_copy_root() to create an empty root This is not safe, as it relies on the source root to be empty. * calls btrfs_read_fs_root() to add it to the cache and trace it properly * calls btrfs_make_root_dir() to initialize the empty new root - create_data_reloc_tree() from mkfs/main.c * calls btrfs_create_tree() to create an empty root * Manually add the root to fs_root cache This is only safe for data reloc tree as it's never updated inside btrfs-progs. But not safe for other subvolume trees. * manually setup the root dir Both have their good and bad aspects, so here we introduce a new helper, btrfs_make_subvolume(): - Calls btrfs_create_tree() to create an empty root - Calls btrfs_read_fs_root() to setup the cache and tracking properly - Calls btrfs_make_root_dir() to initialize the root dir - Calls btrfs_update_root() to reflect the rootdir change So this new helper can replace both create_subvol() and create_data_reloc_tree(). Signed-off-by: Qu Wenruo --- Makefile | 1 + check/main.c | 1 + common/root-tree-utils.c | 107 +++++++++++++++++++++++++++++++++++++++ common/root-tree-utils.h | 26 ++++++++++ convert/main.c | 43 ++-------------- mkfs/common.c | 39 -------------- mkfs/common.h | 2 - mkfs/main.c | 72 +------------------------- 8 files changed, 140 insertions(+), 151 deletions(-) create mode 100644 common/root-tree-utils.c create mode 100644 common/root-tree-utils.h diff --git a/Makefile b/Makefile index 82dfb1b4..c0428c57 100644 --- a/Makefile +++ b/Makefile @@ -221,6 +221,7 @@ objects = \ common/device-utils.o \ common/extent-cache.o \ common/extent-tree-utils.o \ + common/root-tree-utils.o \ common/filesystem-utils.o \ common/format-output.o \ common/fsfeatures.o \ diff --git a/check/main.c b/check/main.c index 693f77c3..8a572c22 100644 --- a/check/main.c +++ b/check/main.c @@ -59,6 +59,7 @@ #include "common/open-utils.h" #include "common/string-utils.h" #include "common/clear-cache.h" +#include "common/root-tree-utils.h" #include "cmds/commands.h" #include "mkfs/common.h" #include "check/common.h" diff --git a/common/root-tree-utils.c b/common/root-tree-utils.c new file mode 100644 index 00000000..a85475aa --- /dev/null +++ b/common/root-tree-utils.c @@ -0,0 +1,107 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include +#include "common/root-tree-utils.h" +#include "common/messages.h" +#include "kernel-shared/disk-io.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; +} + +/* + * Create a subvolume and initialize its content with the top inode. + * + * The created tree root would have its root_ref as 1. + * Thus for subvolumes caller needs to properly add ROOT_BACKREF items. + */ +int btrfs_make_subvolume(struct btrfs_trans_handle *trans, u64 objectid) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *root; + struct btrfs_key key = { + .objectid = objectid, + .type = BTRFS_ROOT_ITEM_KEY, + }; + int ret; + + /* FSTREE is different and can not be created by this function. */ + UASSERT(objectid != BTRFS_FS_TREE_OBJECTID); + UASSERT(is_fstree(objectid) || objectid == BTRFS_DATA_RELOC_TREE_OBJECTID); + + root = btrfs_create_tree(trans, &key); + if (IS_ERR(root)) { + ret = PTR_ERR(root); + goto error; + } + /* + * Free it for now, and re-read it from disk to setup cache and + * tracking. + */ + btrfs_free_fs_root(root); + root = btrfs_read_fs_root(fs_info, &key); + if (IS_ERR(root)) { + ret = PTR_ERR(root); + goto error; + } + ret = btrfs_make_root_dir(trans, root, BTRFS_FIRST_FREE_OBJECTID); + if (ret < 0) + goto error; + ret = btrfs_update_root(trans, fs_info->tree_root, &root->root_key, + &root->root_item); + if (ret < 0) + goto error; + return 0; +error: + btrfs_abort_transaction(trans, ret); + return ret; +} diff --git a/common/root-tree-utils.h b/common/root-tree-utils.h new file mode 100644 index 00000000..5f03aa4e --- /dev/null +++ b/common/root-tree-utils.h @@ -0,0 +1,26 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#ifndef __ROOT_TREE_UTILS_H__ +#define __ROOT_TREE_UTILS_H__ + +#include "kernel-shared/transaction.h" + +int btrfs_make_root_dir(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 objectid); +int btrfs_make_subvolume(struct btrfs_trans_handle *trans, u64 objectid); + +#endif diff --git a/convert/main.c b/convert/main.c index 8e73aa25..31fa146c 100644 --- a/convert/main.c +++ b/convert/main.c @@ -120,6 +120,7 @@ #include "common/box.h" #include "common/open-utils.h" #include "common/extent-tree-utils.h" +#include "common/root-tree-utils.h" #include "common/clear-cache.h" #include "cmds/commands.h" #include "check/repair.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. @@ -1059,13 +1022,13 @@ 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); + ret = btrfs_make_subvolume(trans, CONV_IMAGE_SUBVOL_OBJECTID); if (ret < 0) { error("failed to create subvolume image root: %d", ret); goto err; } /* subvol for data relocation tree */ - ret = create_subvol(trans, root, BTRFS_DATA_RELOC_TREE_OBJECTID); + ret = btrfs_make_subvolume(trans, BTRFS_DATA_RELOC_TREE_OBJECTID); if (ret < 0) { error("failed to create DATA_RELOC root: %d", ret); goto err; diff --git a/mkfs/common.c b/mkfs/common.c index 5de3e0b6..e28b1e82 100644 --- a/mkfs/common.c +++ b/mkfs/common.c @@ -758,45 +758,6 @@ 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 de0ff57b..c600c166 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, bool mixed, u64 zone_size, 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 077da1e3..cf5cae45 100644 --- a/mkfs/main.c +++ b/mkfs/main.c @@ -58,6 +58,7 @@ #include "common/units.h" #include "common/string-utils.h" #include "common/string-table.h" +#include "common/root-tree-utils.h" #include "cmds/commands.h" #include "check/qgroup-verify.h" #include "mkfs/common.h" @@ -734,75 +735,6 @@ 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, &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) { @@ -1939,7 +1871,7 @@ raid_groups: goto out; } - ret = create_data_reloc_tree(trans); + ret = btrfs_make_subvolume(trans, BTRFS_DATA_RELOC_TREE_OBJECTID); if (ret) { error("unable to create data reloc tree: %d", ret); goto out;