On 2019/3/25 下午10:36, Su Yue wrote:
>
>
> On 2019/3/25 4:22 PM, Qu Wenruo wrote:
>> Unlike inodes in fs roots, we don't really check the inode items in root
>> tree, in fact we just skip everything other than ROOT_ITEM and ROOT_REF.
>>
>> This makes invalid inode items sneak into root tree.
>> For example:
>> item 9 key (256 INODE_ITEM 0) itemoff 13702 itemsize 160
>> generation 30 transid 30 size 65536 nbytes 1507328
>> block group 0 mode 0 links 1 uid 0 gid 0 rdev 0
>> ^ Should be 100600
>> sequence 23 flags
>> 0x1b(NODATASUM|NODATACOW|NOCOMPRESS|PREALLOC)
>> atime 0.0 (1970-01-01 08:00:00)
>> ctime 1553491158.189771625 (2019-03-25 13:19:18)
>> mtime 0.0 (1970-01-01 08:00:00)
>> otime 0.0 (1970-01-01 08:00:00)
>>
>> There is a report of such problem in the mail list.
>>
>> This patch will check and repair inode items of free space cache
>> inodes in
>> lowmem mode.
>>
>> Since free space cache inodes doesn't have INODE_REF but still has 1
>> link, we can't use check_inode_item() directly.
>> Instead we only check the inode mode, as that's the important part.
>>
>> The check and repair function: check_repair_free_space_inode() is also
>> exported for original mode.
>>
>> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
>> ---
>> check/mode-common.h | 1 +
>> check/mode-lowmem.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
>> check/mode-lowmem.h | 2 ++
>> 3 files changed, 48 insertions(+)
>>
>> diff --git a/check/mode-common.h b/check/mode-common.h
>> index 8895747adf1d..855f83617854 100644
>> --- a/check/mode-common.h
>> +++ b/check/mode-common.h
>> @@ -24,6 +24,7 @@
>> #include <sys/stat.h>
>> #include "ctree.h"
>>
>> +#define FREE_SPACE_CACHE_INODE_MODE (0100600)
>> /*
>> * Use for tree walk to walk through trees whose leaves/nodes can be
>> shared
>> * between different trees. (Namely subvolume/fs trees)
>> diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c
>> index f37c3b42e6b6..cdb9b66a63a3 100644
>> --- a/check/mode-lowmem.c
>> +++ b/check/mode-lowmem.c
>> @@ -5091,6 +5091,40 @@ out:
>> return err;
>> }
>>
>> +/*
>> + * For free space inodes, we can't call check_inode_item() as free space
>> + * cache inode doesn't have INODE_REF.
>> + * We just check its inode mode.
>> + */
>> +int check_repair_free_space_inode(struct btrfs_fs_info *fs_info,
>> + struct btrfs_path *path)
>> +{
>
>
> In personal taste, I prefer check_free_space_inode() to
> follow existed code.
>
>> + struct btrfs_inode_item *iitem;
>> + struct btrfs_key key;
>> + u32 mode;
>> + int ret = 0;
>> +
>> + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
>> + ASSERT(key.type == BTRFS_INODE_ITEM_KEY && is_fstree(key.objectid));
>> + iitem = btrfs_item_ptr(path->nodes[0], path->slots[0],
>> + struct btrfs_inode_item);
>> + mode = btrfs_inode_mode(path->nodes[0], iitem);
>> + if (mode != FREE_SPACE_CACHE_INODE_MODE) {
>> + error(
>> + "free space cache inode %llu has invalid mode: has 0%o expect 0%o",
>> + key.objectid, mode, FREE_SPACE_CACHE_INODE_MODE);
>> + ret = -EUCLEAN;
>> + if (repair) {
>> + ret = repair_imode_lowmem(fs_info->tree_root,
>> + path);
>> + if (ret < 0)
>> + return ret;
>> + return ret;
>> + }
>> + }
>> + return ret;
>> +}
>> +
>> /*
>> * Check all fs/file tree in low_memory mode.
>> *
>> @@ -5130,6 +5164,17 @@ int check_fs_roots_lowmem(struct btrfs_fs_info
>> *fs_info)
>> btrfs_item_key_to_cpu(node, &key, slot);
>> if (key.objectid > BTRFS_LAST_FREE_OBJECTID)
>> goto out;
>> + if (key.type == BTRFS_INODE_ITEM_KEY &&
>> + is_fstree(key.objectid)) {
>> + ret = check_repair_free_space_inode(fs_info, &path);
>> + /* Check if we still have a valid path to continue */
>
> 'path.nodes[0]' is quite interesting :).
> What about the situation btrfs_search_slot() succeed but failed to
> commit a transaction?
As long as path.nodes[0] exists, we still have a valid path of root
tree, check can continue going.
For that valid path but failed commit case, I believe the most possible
problem would be a corrupted extent tree. And in that case, we can still
continue checking fs tree.
Thanks,
Qu
>
>
> ---
> Su
>> + if (ret < 0 && path.nodes[0]) {
>> + err |= ret;
>> + goto next;
>> + }
>> + if (ret < 0 && !path.nodes[0])
>> + goto out;
>> + }
>> if (key.type == BTRFS_ROOT_ITEM_KEY &&
>> fs_root_objectid(key.objectid)) {
>> if (key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
>> diff --git a/check/mode-lowmem.h b/check/mode-lowmem.h
>> index e0ab30b770d5..d2983fd12eb4 100644
>> --- a/check/mode-lowmem.h
>> +++ b/check/mode-lowmem.h
>> @@ -67,5 +67,7 @@
>>
>> int check_fs_roots_lowmem(struct btrfs_fs_info *fs_info);
>> int check_chunks_and_extents_lowmem(struct btrfs_fs_info *fs_info);
>> +int check_repair_free_space_inode(struct btrfs_fs_info *fs_info,
>> + struct btrfs_path *path);
>>
>> #endif
>>
>
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