On 2018年03月27日 15:06, Lu Fengqi wrote:
> The function is used to determine whether the subvolume is intact.
>
> Signed-off-by: Lu Fengqi <lufq.fnst@xxxxxxxxxxxxxx>
> ---
> Makefile | 3 ++-
> undelete-subvol.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> undelete-subvol.h | 17 +++++++++++++++++
> 3 files changed, 72 insertions(+), 1 deletion(-)
> create mode 100644 undelete-subvol.c
> create mode 100644 undelete-subvol.h
>
> diff --git a/Makefile b/Makefile
> index 6065522a615f..cb38984c7386 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -116,7 +116,8 @@ objects = ctree.o disk-io.o kernel-lib/radix-tree.o extent-tree.o print-tree.o \
> qgroup.o free-space-cache.o kernel-lib/list_sort.o props.o \
> kernel-shared/ulist.o qgroup-verify.o backref.o string-table.o task-utils.o \
> inode.o file.o find-root.o free-space-tree.o help.o send-dump.o \
> - fsfeatures.o kernel-lib/tables.o kernel-lib/raid56.o transaction.o
> + fsfeatures.o kernel-lib/tables.o kernel-lib/raid56.o transaction.o \
> + undelete-subvol.o
> cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \
> cmds-inspect.o cmds-balance.o cmds-send.o cmds-receive.o \
> cmds-quota.o cmds-qgroup.o cmds-replace.o check/main.o \
> diff --git a/undelete-subvol.c b/undelete-subvol.c
> new file mode 100644
> index 000000000000..00fcc4895778
> --- /dev/null
> +++ b/undelete-subvol.c
> @@ -0,0 +1,53 @@
> +/*
> + * Copyright (C) 2018 Fujitsu. All rights reserved.
IIRC David will remove all such copy right line.
Is there some principle about this, David?
> + *
> + * 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.
> + */
> +
> +#include "ctree.h"
> +
> +/*
> + * Determines whether the subvolume is intact, according to the drop_progress
> + * of the root item specified by subvol_id.
> + *
> + * Return true if the subvolume is intact, otherwise return false.
> + */
> +static bool is_subvol_intact(struct btrfs_root *root, u64 subvol_id)
Here we have 2 parameters which can represent a root, so please explain
the meaning of each parameter.
And after looking into the code, @root should be tree root, and in that
case, I prefer passing @fs_info here to get rid of any confusion.
> +{
> + struct btrfs_path path;
> + struct btrfs_key key;
> + struct extent_buffer *leaf;
> + struct btrfs_root_item root_item;
> + u64 offset;
> + int ret;
> +
> + key.objectid = subvol_id;
> + key.type = BTRFS_ROOT_ITEM_KEY;
> + key.offset = 0;
> +
> + btrfs_init_path(&path);
> + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
Instead of setting up keys and search manually, what about using
btrfs_read_fs_root()?
> + if (ret) {
> + ret = false;
> + goto out;
> + }
> +
> + leaf = path.nodes[0];
> + offset = btrfs_item_ptr_offset(leaf, path.slots[0]);
> +
> + read_extent_buffer(leaf, &root_item, offset, sizeof(root_item));
> +
> + /* the subvolume is intact if the objectid of drop_progress == 0 */
> + ret = btrfs_disk_key_objectid(&root_item.drop_progress) ? false : true;
> +
> +out:
> + btrfs_release_path(&path);
> + return ret;
> +}
> diff --git a/undelete-subvol.h b/undelete-subvol.h
> new file mode 100644
> index 000000000000..7cfd100cce37
> --- /dev/null
> +++ b/undelete-subvol.h
> @@ -0,0 +1,17 @@
> +/*
> + * Copyright (C) 2018 Fujitsu. All rights reserved.
> + *
> + * 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.
> + */
> +
> +#ifndef __BTRFS_UNDELETE_SUBVOLUME_H__
I think the empty header is not really needed here.
What about introducing it when we have something here?
Thanks,
Qu
> +#define __BTRFS_UNDELETE_SUBVOLUME_H__
> +
> +#endif
>
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