From 406a4cdea443f75676ff7f072fa7bbb77a97f840 Mon Sep 17 00:00:00 2001 From: Lu Fengqi Date: Sun, 24 Apr 2016 14:41:41 +0800 Subject: [PATCH] btrfs-progs: check: introduce function to check block group item Introduce function check_block_group_item() to check a block group item. It will check the referencer chunk and the used space accounting with extent tree. Signed-off-by: Lu Fengqi Signed-off-by: Qu Wenruo Reviewed-by: Josef Bacik Signed-off-by: David Sterba --- cmds-check.c | 125 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 125 insertions(+) diff --git a/cmds-check.c b/cmds-check.c index ba1d964..305fb03 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -449,6 +449,7 @@ struct root_item_info { #define ITEM_SIZE_MISMATCH (1 << 5) /* Bad item size */ #define UNKNOWN_TYPE (1 << 6) /* Unknown type */ #define ACCOUNTING_MISMATCH (1 << 7) /* Used space accounting error */ +#define CHUNK_TYPE_MISMATCH (1 << 8) static void *print_status_check(void *p) { @@ -9465,6 +9466,130 @@ next: return 0; } +/* + * Check a block group item with its referener (chunk) and its used space + * with extent/metadata item + */ +static int check_block_group_item(struct btrfs_fs_info *fs_info, + struct extent_buffer *eb, int slot) +{ + struct btrfs_root *extent_root = fs_info->extent_root; + struct btrfs_root *chunk_root = fs_info->chunk_root; + struct btrfs_block_group_item *bi; + struct btrfs_block_group_item bg_item; + struct btrfs_path path; + struct btrfs_key bg_key; + struct btrfs_key chunk_key; + struct btrfs_key extent_key; + struct btrfs_chunk *chunk; + struct extent_buffer *leaf; + struct btrfs_extent_item *ei; + u32 nodesize = btrfs_super_nodesize(fs_info->super_copy); + u64 flags; + u64 bg_flags; + u64 used; + u64 total = 0; + int ret; + int err = 0; + + btrfs_item_key_to_cpu(eb, &bg_key, slot); + bi = btrfs_item_ptr(eb, slot, struct btrfs_block_group_item); + read_extent_buffer(eb, &bg_item, (unsigned long)bi, sizeof(bg_item)); + used = btrfs_block_group_used(&bg_item); + bg_flags = btrfs_block_group_flags(&bg_item); + + chunk_key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; + chunk_key.type = BTRFS_CHUNK_ITEM_KEY; + chunk_key.offset = bg_key.objectid; + + btrfs_init_path(&path); + /* Search for the referencer chunk */ + ret = btrfs_search_slot(NULL, chunk_root, &chunk_key, &path, 0, 0); + if (ret) { + error( + "block group[%llu %llu] did not find the related chunk item", + bg_key.objectid, bg_key.offset); + err |= REFERENCER_MISSING; + } else { + chunk = btrfs_item_ptr(path.nodes[0], path.slots[0], + struct btrfs_chunk); + if (btrfs_chunk_length(path.nodes[0], chunk) != + bg_key.offset) { + error( + "block group[%llu %llu] related chunk item length does not match", + bg_key.objectid, bg_key.offset); + err |= REFERENCER_MISMATCH; + } + } + btrfs_release_path(&path); + + /* Search from the block group bytenr */ + extent_key.objectid = bg_key.objectid; + extent_key.type = 0; + extent_key.offset = 0; + + btrfs_init_path(&path); + ret = btrfs_search_slot(NULL, extent_root, &extent_key, &path, 0, 0); + if (ret < 0) + goto out; + + /* Iterate extent tree to account used space */ + while (1) { + leaf = path.nodes[0]; + btrfs_item_key_to_cpu(leaf, &extent_key, path.slots[0]); + if (extent_key.objectid >= bg_key.objectid + bg_key.offset) + break; + + if (extent_key.type != BTRFS_METADATA_ITEM_KEY && + extent_key.type != BTRFS_EXTENT_ITEM_KEY) + goto next; + if (extent_key.objectid < bg_key.objectid) + goto next; + + if (extent_key.type == BTRFS_METADATA_ITEM_KEY) + total += nodesize; + else + total += extent_key.offset; + + ei = btrfs_item_ptr(leaf, path.slots[0], + struct btrfs_extent_item); + flags = btrfs_extent_flags(leaf, ei); + if (flags & BTRFS_EXTENT_FLAG_DATA) { + if (!(bg_flags & BTRFS_BLOCK_GROUP_DATA)) { + error( + "bad extent[%llu, %llu) type mismatch with chunk", + extent_key.objectid, + extent_key.objectid + extent_key.offset); + err |= CHUNK_TYPE_MISMATCH; + } + } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { + if (!(bg_flags & (BTRFS_BLOCK_GROUP_SYSTEM | + BTRFS_BLOCK_GROUP_METADATA))) { + error( + "bad extent[%llu, %llu) type mismatch with chunk", + extent_key.objectid, + extent_key.objectid + nodesize); + err |= CHUNK_TYPE_MISMATCH; + } + } +next: + ret = btrfs_next_item(extent_root, &path); + if (ret) + break; + } + +out: + btrfs_release_path(&path); + + if (total != used) { + error( + "block group[%llu %llu] used %llu but extent items used %llu", + bg_key.objectid, bg_key.offset, used, total); + err |= ACCOUNTING_MISMATCH; + } + return err; +} + static int btrfs_fsck_reinit_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, int overwrite) { -- 2.7.4