On 2018/12/27 下午7:28, Su Yue wrote:
>
>
> On 2018/12/27 3:13 PM, Qu Wenruo wrote:
>> Commit 2a496a5b8b74 ("btrfs-progs: mkfs: precreate the uuid tree")
>> creates uuid tree at mkfs time.
>>
>> However it doesn't populate uuid tree correctly nor just create an empty
>> root.
>> It uses create_tree(), which just copies the content of fs root,
>> containing meaningless INODE_ITEM:
>>
>> v4.15 mkfs (no uuid tree creation) + kernel mount:
>> uuid tree key (UUID_TREE ROOT_ITEM 0)
>> leaf 30572544 items 1 free space 16250 generation 7 owner UUID_TREE
>> leaf 30572544 flags 0x1(WRITTEN) backref revision 1
>> fs uuid 33ecddef-fc86-481a-93ce-846b01c11376
>> chunk uuid 9e58f646-b0da-43ca-9c7d-8bbe3e120246
>> item 0 key (0x92457c59d31491be UUID_KEY_SUBVOL 0xef908b5e79aa76a1)
>> itemoff 16275 itemsize 8
>> subvol_id 5
>>
>> v4.19.1 mkfs (incorrect one), no kernel mount:
>> uuid tree key (UUID_TREE ROOT_ITEM 0)
>> leaf 30507008 items 2 free space 16061 generation 4 owner UUID_TREE
>> leaf 30507008 flags 0x1(WRITTEN) backref revision 1
>> fs uuid 162f5333-9b5d-4217-877c-ddaeaa79398e
>> chunk uuid 7bc2c5c6-a6d2-4eec-a513-142b549c6541
>> item 0 key (256 INODE_ITEM 0) itemoff 16123 itemsize 160
>> generation 3 transid 0 size 0 nbytes 16384
>> block group 0 mode 40755 links 1 uid 0 gid 0 rdev 0
>> sequence 0 flags 0x0(none)
>> item 1 key (256 INODE_REF 256) itemoff 16111 itemsize 12
>> index 0 namelen 2 name: ..
>>
>> This patchset will fix it by populuating uuid tree properly:
>> (NOTE: due to tree-checker, kernel doesn't accept empty uuid tree, so we
>> can only fix it by populating uuid tree correctly)
>>
>> w/ this patchset, no kernel mount:
>> uuid tree key (UUID_TREE ROOT_ITEM 0)
>> leaf 30507008 items 1 free space 16250 generation 4 owner UUID_TREE
>> leaf 30507008 flags 0x1(WRITTEN) backref revision 1
>> fs uuid ae53079e-dbbc-409b-a565-5326c7b27731
>> chunk uuid b5fb1bea-f20d-4af1-80f8-6ca3f0038d67
>> item 0 key (0x334ba6b032d89c07 UUID_KEY_SUBVOL 0x86cde09cb78bcca0)
>> itemoff 16275 itemsize 8
>> subvol_id 5
>>
>> For kernel, except tree-checker needs an non-empty uuid tree, both all
>> above behavior won't cause problem, but it's always better to keep a
>> good standardized behavior.
>>
>> Furthermore, to avoid such problem from happening again, rename the
>> function create_tree() to create_empty_tree() and create_inode_tree(),
>> without an @root parameter to avoid such problem.
>>
>> Fixes: 2a496a5b8b74 ("btrfs-progs: mkfs: precreate the uuid tree")
>> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
>> ---
>> disk-io.c | 4 ++
>> mkfs/common.c | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++
>> mkfs/common.h | 3 ++
>> mkfs/main.c | 36 +-----------------
>> 4 files changed, 112 insertions(+), 34 deletions(-)
>>
>> diff --git a/disk-io.c b/disk-io.c
>> index 5fafa144c0d3..2cb7f2097fc9 100644
>> --- a/disk-io.c
>> +++ b/disk-io.c
>> @@ -694,6 +694,8 @@ void btrfs_free_fs_info(struct btrfs_fs_info
>> *fs_info)
>> {
>> if (fs_info->quota_root)
>> free(fs_info->quota_root);
>> + if (fs_info->uuid_root)
>> + free(fs_info->uuid_root);
>> free(fs_info->tree_root);
>> free(fs_info->extent_root);
>> @@ -964,6 +966,8 @@ void btrfs_release_all_roots(struct btrfs_fs_info
>> *fs_info)
>> free_extent_buffer(fs_info->log_root_tree->node);
>> if (fs_info->chunk_root)
>> free_extent_buffer(fs_info->chunk_root->node);
>> + if (fs_info->uuid_root)
>> + free_extent_buffer(fs_info->uuid_root->node);
>> }
>> static void free_map_lookup(struct cache_extent *ce)
>> diff --git a/mkfs/common.c b/mkfs/common.c
>> index f7e3badcf2b9..1f5e1d03a6e3 100644
>> --- a/mkfs/common.c
>> +++ b/mkfs/common.c
>> @@ -23,6 +23,7 @@
>> #include "disk-io.h"
>> #include "volumes.h"
>> #include "utils.h"
>> +#include "transaction.h"
>> #include "mkfs/common.h"
>> static u64 reference_root_table[] = {
>> @@ -822,4 +823,106 @@ int test_minimum_size(const char *file, u64
>> min_dev_size)
>> return 0;
>> }
>> +/*
>> + * Create a tree with all its content copied from @source
>> + *
>> + * Caller must ensure @source only has one leaf.
>> + */
>> +static int __create_tree(struct btrfs_trans_handle *trans,
>> + struct btrfs_root *root, u64 objectid)
>> +{
>> + struct btrfs_fs_info *fs_info = trans->fs_info;
>> + struct btrfs_key location;
>> + struct btrfs_root_item root_item;
>> + struct extent_buffer *tmp;
>> + u8 uuid[BTRFS_UUID_SIZE] = {0};
>> + int ret;
>> +
>> + ASSERT(btrfs_header_level(root->node) == 0);
>> +
>> + ret = btrfs_copy_root(trans, root, root->node, &tmp, 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);
>> + /* clear uuid and o/ctime of source tree */
>> + memcpy(root_item.uuid, uuid, BTRFS_UUID_SIZE);
>> + btrfs_set_stack_timespec_sec(&root_item.otime, 0);
>> + btrfs_set_stack_timespec_sec(&root_item.ctime, 0);
>> + free_extent_buffer(tmp);
>> +
>> + location.objectid = objectid;
>> + location.type = BTRFS_ROOT_ITEM_KEY;
>> + location.offset = 0;
>> + ret = btrfs_insert_root(trans, fs_info->tree_root,
>> + &location, &root_item);
>> +
>> + return ret;
>> +}
>> +
>> +/*
>> + * Create an *EMPTY* tree
>> + *
>> + * Caller must ensure at the time of calling, csum tree is still empty
>> + */
>> +static int create_empty_tree(struct btrfs_trans_handle *trans, u64
>> objectid)
>> +{
>> + struct btrfs_root *csum_root = trans->fs_info->csum_root;
>> +
>> + ASSERT(btrfs_header_level(csum_root->node) == 0 &&
>> + btrfs_header_nritems(csum_root->node) == 0);
>> + return __create_tree(trans, csum_root, objectid);
>> +}
>> +/*
>> + * Create a tree containing an root inode
>> + *
>> + * Caller must ensure at the time of calling, fs tree only contains 2
>> items
>> + * (one for INODE_ITEM and one for INODE_REF)
>> + */
>> +int create_inode_tree(struct btrfs_trans_handle *trans, u64 objectid)
>> +{
>> + struct btrfs_root *fs_root = trans->fs_info->fs_root;
>> +
>> + ASSERT(btrfs_header_level(fs_root->node) == 0 &&
>> + btrfs_header_nritems(fs_root->node) == 2);
>> + return __create_tree(trans, fs_root, objectid);
>> +}
>> +
>> +int create_uuid_tree(struct btrfs_trans_handle *trans)
>> +{
>> + struct btrfs_fs_info *fs_info = trans->fs_info;
>> + struct btrfs_root *uuid_root = fs_info->uuid_root;
>> + struct btrfs_key key;
>> + int ret;
>> +
>> + if (!uuid_root) {
>> + ret = create_empty_tree(trans, BTRFS_UUID_TREE_OBJECTID);
>> + if (ret < 0) {
>> + errno = -ret;
>> + error("failed to create uuid root: %m");
>
> In personal taste, I don't like such assignment.
> Let the community say.
That's the new trend. I'm not a big fan either but it at least saves
some strerr(-ret) calls.
Thanks,
Qu
>
> Others look nice to me.
>
> Thanks,
> Su
>
>> + return ret;
>> + }
>> + key.objectid = BTRFS_UUID_TREE_OBJECTID;
>> + key.type = BTRFS_ROOT_ITEM_KEY;
>> + key.offset = 0;
>> + uuid_root = btrfs_read_fs_root_no_cache(fs_info, &key);
>> + if (IS_ERR(uuid_root)) {
>> + errno = -PTR_ERR(uuid_root);
>> + error("failed to read uuid root: %m");
>> + return PTR_ERR(uuid_root);
>> + }
>> + fs_info->uuid_root = uuid_root;
>> + }
>> + ret = btrfs_uuid_tree_add(trans, fs_info->fs_root->root_item.uuid,
>> + BTRFS_UUID_KEY_SUBVOL,
>> + fs_info->fs_root->root_key.objectid);
>> + if (ret < 0) {
>> + errno = -ret;
>> + error("failed to add uuid tree entry for fs root: %m");
>> + }
>> + return ret;
>> +}
>> diff --git a/mkfs/common.h b/mkfs/common.h
>> index 28912906d0a9..adb5d561c38d 100644
>> --- a/mkfs/common.h
>> +++ b/mkfs/common.h
>> @@ -75,4 +75,7 @@ int test_num_disk_vs_raid(u64 metadata_profile, u64
>> data_profile,
>> int test_status_for_mkfs(const char *file, bool force_overwrite);
>> int test_dev_for_mkfs(const char *file, int force_overwrite);
>> +int create_uuid_tree(struct btrfs_trans_handle *trans);
>> +int create_inode_tree(struct btrfs_trans_handle *trans, u64 objectid);
>> +
>> #endif
>> diff --git a/mkfs/main.c b/mkfs/main.c
>> index b6748f7fe853..ea3d1ae80e5e 100644
>> --- a/mkfs/main.c
>> +++ b/mkfs/main.c
>> @@ -309,38 +309,6 @@ static int create_raid_groups(struct
>> btrfs_trans_handle *trans,
>> return ret;
>> }
>> -static int create_tree(struct btrfs_trans_handle *trans,
>> - struct btrfs_root *root, u64 objectid)
>> -{
>> - struct btrfs_key location;
>> - struct btrfs_root_item root_item;
>> - struct extent_buffer *tmp;
>> - u8 uuid[BTRFS_UUID_SIZE] = {0};
>> - int ret;
>> -
>> - ret = btrfs_copy_root(trans, root, root->node, &tmp, 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);
>> - /* clear uuid and o/ctime of source tree */
>> - memcpy(root_item.uuid, uuid, BTRFS_UUID_SIZE);
>> - btrfs_set_stack_timespec_sec(&root_item.otime, 0);
>> - btrfs_set_stack_timespec_sec(&root_item.ctime, 0);
>> - free_extent_buffer(tmp);
>> -
>> - location.objectid = objectid;
>> - location.type = BTRFS_ROOT_ITEM_KEY;
>> - location.offset = 0;
>> - ret = btrfs_insert_root(trans, root->fs_info->tree_root,
>> - &location, &root_item);
>> -
>> - return ret;
>> -}
>> -
>> static void print_usage(int ret)
>> {
>> printf("Usage: mkfs.btrfs [options] dev [ dev ... ]\n");
>> @@ -1203,13 +1171,13 @@ raid_groups:
>> goto out;
>> }
>> - ret = create_tree(trans, root, BTRFS_DATA_RELOC_TREE_OBJECTID);
>> + ret = create_inode_tree(trans, BTRFS_DATA_RELOC_TREE_OBJECTID);
>> if (ret) {
>> error("unable to create data reloc tree: %d", ret);
>> goto out;
>> }
>> - ret = create_tree(trans, root, BTRFS_UUID_TREE_OBJECTID);
>> + ret = create_uuid_tree(trans);
>> if (ret)
>> warning(
>> "unable to create uuid tree, will be created after mount: %d",
>> ret);
>>
>
Attachment:
signature.asc
Description: OpenPGP digital signature
