Re: [PATCH v2 02/10] btrfs-progs: Add support to suppress tree block csum error output.

[Qu Wenruo <quwenruo@cn.fujitsu.com>]

-------- Original Message --------
Subject: Re: [PATCH v2 02/10] btrfs-progs: Add support to suppress tree 
block csum error output.
From: David Sterba <dsterba@suse.cz>
To: Qu Wenruo <quwenruo@cn.fujitsu.com>
Date: 2015年01月29日 02:16
> On Mon, Jan 19, 2015 at 02:45:04PM +0800, Qu Wenruo wrote:
>> Add new open ctree flag OPEN_CTREE_SUPPRESS_ERROR to suppress tree block
>> csum error output.
>>
>> @@ -996,6 +996,7 @@ struct btrfs_fs_info {
>>   	unsigned int on_restoring:1;
>>   	unsigned int is_chunk_recover:1;
>>   	unsigned int quota_enabled:1;
>> +	unsigned int suppress_error:1;
> This is confusing, it suppresses only csum errors.
Indeed, what about suprress_csum_err?
>
>> --- a/disk-io.c
>> +++ b/disk-io.c
>> @@ -42,7 +42,8 @@ static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
>>   	struct btrfs_fs_devices *fs_devices;
>>   	int ret = 1;
>>   
>> -	if (buf->start != btrfs_header_bytenr(buf)) {
>> +	if (buf->start != btrfs_header_bytenr(buf) &&
>> +	    !root->fs_info->suppress_error) {
> Though here it's used to skip block start mismatch error. But looking at
> the rest of the code, it's better to put this check to the caller and
> keep check_tree_block as is.
Did you mean move the bytenr check out of check_tree_block() and caller 
do the bytenr check?
If so, I'll change it soon.

Thanks,
Qu
>
>>   		printk("Check tree block failed, want=%Lu, have=%Lu\n",
>>   		       buf->start, btrfs_header_bytenr(buf));
>>   		return ret;
>> @@ -118,6 +119,8 @@ int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
>>   {
>>   	u16 csum_size =
>>   		btrfs_super_csum_size(root->fs_info->super_copy);
>> +	if (verify && root->fs_info->suppress_error)
>> +		return verify_tree_block_csum_silent(buf, csum_size);
>>   	return csum_tree_block_size(buf, csum_size, verify);
>>   }
>>   
>> @@ -282,10 +285,13 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
>>   			return eb;
>>   		}
>>   		if (ignore) {
>> -			if (check_tree_block(root, eb))
>> -				printk("read block failed check_tree_block\n");
>> -			else
>> -				printk("Csum didn't match\n");
>> +			if (check_tree_block(root, eb)) {
>> +				if (!root->fs_info->suppress_error)
>> +					printk("read block failed check_tree_block\n");
>> +			} else {
>> +				if (!root->fs_info->suppress_error)
>> +					printk("Csum didn't match\n");
>> +			}
>>   			break;
>>   		}
>>   		num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
>> @@ -1112,6 +1118,8 @@ static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
>>   	}
>>   	if (flags & OPEN_CTREE_RESTORE)
>>   		fs_info->on_restoring = 1;
>> +	if (flags & OPEN_CTREE_SUPPRESS_ERROR)
>> +		fs_info->suppress_error = 1;
>>   
>>   	ret = btrfs_scan_fs_devices(fp, path, &fs_devices, sb_bytenr,
>>   				    (flags & OPEN_CTREE_RECOVER_SUPER));
>> diff --git a/disk-io.h b/disk-io.h
>> index e12870e..90ede6b 100644
>> --- a/disk-io.h
>> +++ b/disk-io.h
>> @@ -33,6 +33,7 @@ enum btrfs_open_ctree_flags {
>>   	OPEN_CTREE_RESTORE		= (1 << 4),
>>   	OPEN_CTREE_NO_BLOCK_GROUPS	= (1 << 5),
>>   	OPEN_CTREE_EXCLUSIVE		= (1 << 6),
>> +	OPEN_CTREE_SUPPRESS_ERROR	= (1 << 7), /* Suppress csum error */
>>   };
>>   
>>   static inline u64 btrfs_sb_offset(int mirror)