[PATCH] erofs: [PATCH v2] Prevent entering an infinite loop when i is 0

[Gao Xiang]

On 2024/8/23 11:05, liujinbao1 wrote:
> From: liujinbao1 <liujinbao1 at xiaomi.com>
> 
> When i=0 and err is not equal to 0,
> the while(-1) loop will enter into an
> infinite loop. This patch avoids this issue.
> 
> Signed-off-by: liujinbao1 <liujinbao1 at xiaomi.com>
> ---
>   fs/erofs/decompressor.c | 8 +++-----
>   1 file changed, 3 insertions(+), 5 deletions(-)
> 
>> Hi,

The patch is corrupted and the patch subject
line is also broken.

I think it should be:
[PATCH v2] erofs: prevent entering an infinite loop when i is 0

>>
>> On 2024/8/22 14:27, liujinbao1 wrote:
>>> From: liujinbao1 <liujinbao1 at xiaomi.com>
>>>
>>> When i=0 and err is not equal to 0,
>>> the while(-1) loop will enter into an
>>> infinite loop. This patch avoids this issue.
>>
>> Missing your Signed-off-by here.
>>
>>> ---
>>>   fs/erofs/decompressor.c | 2 ++
>>>   1 file changed, 2 insertions(+)
>>>
>>> diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index
>>> c2253b6a5416..1b2b8cc7911c 100644
>>> --- a/fs/erofs/decompressor.c
>>> +++ b/fs/erofs/decompressor.c
>>> @@ -539,6 +539,8 @@ int __init z_erofs_init_decompressor(void)
>>>       for (i = 0; i < Z_EROFS_COMPRESSION_MAX; ++i) {
>>>               err = z_erofs_decomp[i] ? z_erofs_decomp[i]->init() : 0;
>>>               if (err) {
>>> +                    if (!i)
>>> +                            return err;
>>>                       while (--i)
>>>                               if (z_erofs_decomp[i])
>>>                                       z_erofs_decomp[i]->exit();
>>
>>
>> Thanks for catching this, how about the following diff (space-demaged).
>>
>> If it looks good to you, could you please send another version?
> 
>> diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index c2253b6a5416..c9b2bc1309d2 100644
>> --- a/fs/erofs/decompressor.c
>> +++ b/fs/erofs/decompressor.c
>> @@ -534,18 +534,16 @@ int z_erofs_parse_cfgs(struct super_block *sb, struct erofs_super_block *dsb)
>>
>> int __init z_erofs_init_decompressor(void)
>> {
>> -      int i, err;
>> +      int i, err = 0;
>>
>>         for (i = 0; i < Z_EROFS_COMPRESSION_MAX; ++i) {
>>                 err = z_erofs_decomp[i] ? z_erofs_decomp[i]->init() : 0;
>> -              if (err) {
>> +              if (err && i)
>>                         while (--i)
>>                                 if (z_erofs_decomp[i])
>>                                         z_erofs_decomp[i]->exit();
>> -                      return err;
> +						break;
>> -              }
>>         }
>> -      return 0;
>> +      return err;
>> }
>>
> missing break?

Why needing a break?

Thanks,
Gao Xiang