diff mbox series

Fix logically dead code

Message ID 20241004103051.43862-1-advaitdhamorikar@gmail.com (mailing list archive)
State New, archived
Headers show
Series Fix logically dead code | expand

Commit Message

Advait Dhamorikar Oct. 4, 2024, 10:30 a.m. UTC
The if condition in collect_sample: can never be satisfied
because of a logical contradiction.

Fixes: 94ae8c3fee94 ("smb: client: compress: LZ77 code improvements cleanup")
Signed-off-by: Advait Dhamorikar <advaitdhamorikar@gmail.com>
---
 fs/smb/client/compress.c | 4 ----
 1 file changed, 4 deletions(-)

Comments

Shuah Khan Oct. 4, 2024, 6 p.m. UTC | #1
On 10/4/24 04:30, Advait Dhamorikar wrote:
> The if condition in collect_sample: can never be satisfied
> because of a logical contradiction.

Add a better change log explaining how you found the problem.

Also your short log is missing subsystem information.
Check submitting patches document for details on how
to write shot logs and change logs.

> 
> Fixes: 94ae8c3fee94 ("smb: client: compress: LZ77 code improvements cleanup")
> Signed-off-by: Advait Dhamorikar <advaitdhamorikar@gmail.com>
> ---
>   fs/smb/client/compress.c | 4 ----
>   1 file changed, 4 deletions(-)
> 
> diff --git a/fs/smb/client/compress.c b/fs/smb/client/compress.c
> index 63b5a55b7a57..766b4de13da7 100644
> --- a/fs/smb/client/compress.c
> +++ b/fs/smb/client/compress.c
> @@ -166,7 +166,6 @@ static int collect_sample(const struct iov_iter *iter, ssize_t max, u8 *sample)
>   	loff_t start = iter->xarray_start + iter->iov_offset;
>   	pgoff_t last, index = start / PAGE_SIZE;
>   	size_t len, off, foff;
> -	ssize_t ret = 0;
>   	void *p;
>   	int s = 0;
>   
> @@ -193,9 +192,6 @@ static int collect_sample(const struct iov_iter *iter, ssize_t max, u8 *sample)
>   				memcpy(&sample[s], p, len2);
>   				kunmap_local(p);
>   
> -				if (ret < 0)
> -					return ret;
> -

The change itself looks good to me - unless the intent is to
check the return from kunmap_local() and take action based on
it instead of removing the conditional that checks the ret value.

>   				s += len2;
>   
>   				if (len2 < SZ_2K || s >= max - SZ_2K)

thanks,
-- Shuah
Christophe JAILLET Oct. 4, 2024, 6:12 p.m. UTC | #2
Le 04/10/2024 à 20:00, Shuah Khan a écrit :
> On 10/4/24 04:30, Advait Dhamorikar wrote:
>> The if condition in collect_sample: can never be satisfied
>> because of a logical contradiction.
> 
> Add a better change log explaining how you found the problem.
> 
> Also your short log is missing subsystem information.
> Check submitting patches document for details on how
> to write shot logs and change logs.
> 
>>
>> Fixes: 94ae8c3fee94 ("smb: client: compress: LZ77 code improvements 
>> cleanup")
>> Signed-off-by: Advait Dhamorikar <advaitdhamorikar@gmail.com>
>> ---
>>   fs/smb/client/compress.c | 4 ----
>>   1 file changed, 4 deletions(-)
>>
>> diff --git a/fs/smb/client/compress.c b/fs/smb/client/compress.c
>> index 63b5a55b7a57..766b4de13da7 100644
>> --- a/fs/smb/client/compress.c
>> +++ b/fs/smb/client/compress.c
>> @@ -166,7 +166,6 @@ static int collect_sample(const struct iov_iter 
>> *iter, ssize_t max, u8 *sample)
>>       loff_t start = iter->xarray_start + iter->iov_offset;
>>       pgoff_t last, index = start / PAGE_SIZE;
>>       size_t len, off, foff;
>> -    ssize_t ret = 0;
>>       void *p;
>>       int s = 0;
>> @@ -193,9 +192,6 @@ static int collect_sample(const struct iov_iter 
>> *iter, ssize_t max, u8 *sample)
>>                   memcpy(&sample[s], p, len2);
>>                   kunmap_local(p);
>> -                if (ret < 0)
>> -                    return ret;
>> -
> 
> The change itself looks good to me - unless the intent is to
> check the return from kunmap_local() and take action based on
> it instead of removing the conditional that checks the ret value.

IIUC, kunmap_local() does not return anything.

CJ

> 
>>                   s += len2;
>>                   if (len2 < SZ_2K || s >= max - SZ_2K)
> 
> thanks,
> -- Shuah
> 
>
David Howells Oct. 5, 2024, 8:19 p.m. UTC | #3
Can you tag your subject with some sort of subsystem ID so that we know what
it affects?  Something like "cifs:" or "smb:" in this case.

Thanks,
David
diff mbox series

Patch

diff --git a/fs/smb/client/compress.c b/fs/smb/client/compress.c
index 63b5a55b7a57..766b4de13da7 100644
--- a/fs/smb/client/compress.c
+++ b/fs/smb/client/compress.c
@@ -166,7 +166,6 @@  static int collect_sample(const struct iov_iter *iter, ssize_t max, u8 *sample)
 	loff_t start = iter->xarray_start + iter->iov_offset;
 	pgoff_t last, index = start / PAGE_SIZE;
 	size_t len, off, foff;
-	ssize_t ret = 0;
 	void *p;
 	int s = 0;
 
@@ -193,9 +192,6 @@  static int collect_sample(const struct iov_iter *iter, ssize_t max, u8 *sample)
 				memcpy(&sample[s], p, len2);
 				kunmap_local(p);
 
-				if (ret < 0)
-					return ret;
-
 				s += len2;
 
 				if (len2 < SZ_2K || s >= max - SZ_2K)