[PATCH] erofs-utils: fix `--blobdev=X`

[Gao Xiang]

Hi Hongbo,

On 2025/4/27 10:49, Hongbo Li wrote:
> 
> 
> On 2025/4/27 10:15, Gao Xiang wrote:
>> Create one if the file doesn't exist.
>>
>> Fixes: b6b741d8daaf ("erofs-utils: lib: get rid of tmpfile()")
> 
> I think the real fixes should be Fixes: bbeec3c93076 ("erofs-utils: mkfs: add extra blob device support").

Prior to b6b741d8daaf, the functionality is ok since
fopen(..,"wb") will create the file too.

>> Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>
>> ---
>>   lib/blobchunk.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/lib/blobchunk.c b/lib/blobchunk.c
>> index e6386d6..301f46a 100644
>> --- a/lib/blobchunk.c
>> +++ b/lib/blobchunk.c
>> @@ -627,7 +627,8 @@ int erofs_blob_init(const char *blobfile_path, erofs_off_t chunksize)
>>           blobfile = erofs_tmpfile();
>>           multidev = false;
>>       } else {
>> -        blobfile = open(blobfile_path, O_WRONLY | O_BINARY);
>> +        blobfile = open(blobfile_path, O_WRONLY | O_CREAT |
>> +                        O_TRUNC | O_BINARY, 0666);
> To maintain consistency, is it better to set the default permission to 0644?

I tend to switch all modes to 0666 around the codebase
in the future, since umask(022) will mask them into 0644.

Thanks,
Gao Xiang