Re: [PATCH v3 6/7] btrfs-progs: check: update inline extent length checking

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

在 2026/7/8 14:30, Daniel Vacek 写道:
> On Wed, 8 Jul 2026 at 00:43, Qu Wenruo <wqu@suse.com> wrote:
>> 在 2026/7/7 23:57, Daniel Vacek 写道:
>>> From: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
>>>
>>> As part of the encryption changes, encrypted inline file extents record
>>> their actual data length in ram_bytes, like compressed inline file
>>> extents, while the item's length records the actual size. As such,
>>> encrypted inline extents must be treated like compressed ones for
>>> inode length consistency checking.
>>>
>>> Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
>>> Signed-off-by: Daniel Vacek <neelx@suse.com>
>>> ---
>>>    check/main.c | 31 +++++++++++++++++--------------
>>>    1 file changed, 17 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/check/main.c b/check/main.c
>>> index 9447b01e..cadcfef0 100644
>>> --- a/check/main.c
>>> +++ b/check/main.c
>>> @@ -1720,9 +1720,7 @@ static int process_file_extent(struct btrfs_root *root,
>>>        u64 disk_bytenr = 0;
>>>        u64 extent_offset = 0;
>>>        u64 mask = gfs_info->sectorsize - 1;
>>> -     u32 max_inline_size = min_t(u32, mask,
>>> -                             BTRFS_MAX_INLINE_DATA_SIZE(gfs_info));
>>> -     u8 compression;
>>> +     u8 compression, encryption;
>>>        int extent_type;
>>>        int ret;
>>>
>>> @@ -1747,25 +1745,30 @@ static int process_file_extent(struct btrfs_root *root,
>>>        fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
>>>        extent_type = btrfs_file_extent_type(eb, fi);
>>>        compression = btrfs_file_extent_compression(eb, fi);
>>> +     encryption  = btrfs_file_extent_encryption(eb, fi);
>>>
>>>        if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
>>> -             num_bytes = btrfs_file_extent_ram_bytes(eb, fi);
>>> -             if (num_bytes == 0)
>>> +             u32 max_inline_size = min_t(u32, mask,
>>> +                                     BTRFS_MAX_INLINE_DATA_SIZE(gfs_info));
>>> +             u64 num_disk_bytes = btrfs_file_extent_inline_item_len(eb, slot);
>>> +             u64 num_decoded_bytes = btrfs_file_extent_ram_bytes(eb, fi);
>>> +             if (num_decoded_bytes == 0)
>>>                        rec->errors |= I_ERR_BAD_FILE_EXTENT;
>>> -             if (compression) {
>>> -                     if (btrfs_file_extent_inline_item_len(eb, slot) >
>>> -                         max_inline_size ||
>>> -                         num_bytes > gfs_info->sectorsize)
>>> +             if (compression || encryption) {
>>> +                     if (encryption)
>>> +                             max_inline_size = min_t(u32, gfs_info->sectorsize,
>>> +                                     BTRFS_MAX_INLINE_DATA_SIZE(gfs_info));
>>
>> The change looks good to me now.
>>
>> However I'm just curious, is it possible to limit the encrypted data
>> size to sectorsize-1?
>>
>> Or it is some fscrypt limit internal requiring a power-of-2 size or just
>> lack of interface?
> 
> The encrypted data has the granularity of the cipher block size. With
> AES, it's 16 bytes. Hence why.
> Eventually the best we could do would be sectorsize-16. But then, if
> the cipher changed in the future...

Thanks a lot, that explains the reason why we can not follow the old 
sectorsize - 1 limit.

Thanks,
Qu

> 
> --nX
> 
>> Anyway I won't object this new change.
>>
>> Thanks,
>> Qu
>>
>>> +                     if (num_disk_bytes > max_inline_size ||
>>> +                         num_decoded_bytes > gfs_info->sectorsize)
>>>                                rec->errors |= I_ERR_FILE_EXTENT_TOO_LARGE;
>>>                } else {
>>> -                     if (num_bytes > max_inline_size)
>>> +                     if (num_decoded_bytes > max_inline_size)
>>>                                rec->errors |= I_ERR_FILE_EXTENT_TOO_LARGE;
>>> -                     if (btrfs_file_extent_inline_item_len(eb, slot) !=
>>> -                         num_bytes)
>>> +                     if (num_disk_bytes != num_decoded_bytes)
>>>                                rec->errors |= I_ERR_INLINE_RAM_BYTES_WRONG;
>>>                }
>>> -             rec->found_size += num_bytes;
>>> -             num_bytes = (num_bytes + mask) & ~mask;
>>> +             rec->found_size += num_decoded_bytes;
>>> +             num_bytes = (num_decoded_bytes + mask) & ~mask;
>>>        } else if (extent_type == BTRFS_FILE_EXTENT_REG ||
>>>                   extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
>>>                num_bytes = btrfs_file_extent_num_bytes(eb, fi);
>>
>