Re: [PATCH v2 4/7] btrfs-progs: check/original mode: Check inline extent size

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

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On 2018年03月13日 16:40, Nikolay Borisov wrote:
> 
> 
> On 13.03.2018 03:56, Qu Wenruo wrote:
>> For inline compressed file extent, kernel doesn't allow inline extent
>> ram size larger than sector size and on-disk inline extent size should
>> not exceed BTRFS_MAX_INLINE_DATA_SIZE().
>>
>> For inline uncompressed file extent, kernel doesn't allow inline extent
>> ram and on-disk size larger than either BTRFS_MAX_INLINE_DATA_SIZE() or
>> sector size.
>>
>> Check it in original mode.
>>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>> ---
>>  check/main.c          | 16 ++++++++++++++++
>>  check/mode-original.h |  1 +
>>  2 files changed, 17 insertions(+)
>>
>> diff --git a/check/main.c b/check/main.c
>> index 97baae583f04..7821faa929a3 100644
>> --- a/check/main.c
>> +++ b/check/main.c
>> @@ -560,6 +560,8 @@ static void print_inode_error(struct btrfs_root *root, struct inode_record *rec)
>>  		fprintf(stderr, ", bad file extent");
>>  	if (errors & I_ERR_FILE_EXTENT_OVERLAP)
>>  		fprintf(stderr, ", file extent overlap");
>> +	if (errors & I_ERR_FILE_EXTENT_TOO_LARGE)
>> +		fprintf(stderr, ", inline file extent too large");
> 
> offtopic:
> 
> So in lowmem mode when the error is printed the user is informed what is
> the maximum expected size, but in normal mode this is not case? Why is
> that? I can see other error messages also don't print out expected values?

The difference is in how different mode handles error.

For normal mode, we use bitmap to indicate error, which can only tell us
what's wrong, but without extra info.

In lowmem mode, we just output the error when we found it, so we have
extra info.

I'm not sure the difference makes sense or not, but at least lowmem mode
is a little more friendly for developer. (For end user, I don't know if
such detailed output would help)


Thanks,
Qu

> 
>>  	if (errors & I_ERR_FILE_EXTENT_DISCOUNT)
>>  		fprintf(stderr, ", file extent discount");
>>  	if (errors & I_ERR_DIR_ISIZE_WRONG)
>> @@ -1433,6 +1435,8 @@ static int process_file_extent(struct btrfs_root *root,
>>  	u64 disk_bytenr = 0;
>>  	u64 extent_offset = 0;
>>  	u64 mask = root->fs_info->sectorsize - 1;
>> +	u32 max_inline_size = min_t(u32, mask,
>> +				BTRFS_MAX_INLINE_DATA_SIZE(root->fs_info));
>>  	int extent_type;
>>  	int ret;
>>  
>> @@ -1458,9 +1462,21 @@ static int process_file_extent(struct btrfs_root *root,
>>  	extent_type = btrfs_file_extent_type(eb, fi);
>>  
>>  	if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
>> +		u8 compression = btrfs_file_extent_compression(eb, fi);
>> +		struct btrfs_item *item = btrfs_item_nr(slot);
>> +
>>  		num_bytes = btrfs_file_extent_inline_len(eb, slot, fi);
>>  		if (num_bytes == 0)
>>  			rec->errors |= I_ERR_BAD_FILE_EXTENT;
>> +		if (compression) {
>> +			if (btrfs_file_extent_inline_item_len(eb, item) >
>> +			    max_inline_size ||
>> +			    num_bytes > root->fs_info->sectorsize)
>> +				rec->errors |= I_ERR_FILE_EXTENT_TOO_LARGE;
>> +		} else {
>> +			if (num_bytes > max_inline_size)
>> +				rec->errors |= I_ERR_FILE_EXTENT_TOO_LARGE;
>> +		}
>>  		rec->found_size += num_bytes;
>>  		num_bytes = (num_bytes + mask) & ~mask;
>>  	} else if (extent_type == BTRFS_FILE_EXTENT_REG ||
>> diff --git a/check/mode-original.h b/check/mode-original.h
>> index f859af478f0f..368de692fdd1 100644
>> --- a/check/mode-original.h
>> +++ b/check/mode-original.h
>> @@ -185,6 +185,7 @@ struct file_extent_hole {
>>  #define I_ERR_SOME_CSUM_MISSING		(1 << 12)
>>  #define I_ERR_LINK_COUNT_WRONG		(1 << 13)
>>  #define I_ERR_FILE_EXTENT_ORPHAN	(1 << 14)
>> +#define I_ERR_FILE_EXTENT_TOO_LARGE	(1 << 15)
>>  
>>  struct inode_record {
>>  	struct list_head backrefs;
>>
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