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

[liujinbao1 <jinbaoliu365@gmail.com>]

From: liujinbao1 <liujinbao1@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@xiaomi.com>
---
 fs/erofs/decompressor.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

>Hi,
> 
>On 2024/8/22 14:27, liujinbao1 wrote:
>> From: liujinbao1 <liujinbao1@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?
-- 
2.25.1