[U-Boot] [PATCH] fix: fw_env: Prevent writing error message on special files, which don't support fsync

[Łukasz Majewski]

Hi Michael,

> Hi Lukasz,
>
> Am Sonntag, 27. August 2017, 13:46:22 CEST schrieb Lukasz Majewski:
>> According to fsync specification [1] some special files (e.g., a pipe, FIFO,
>> or socket) don't support synchronization and return either EROFS or EINVAL.
>>
>> On the linux side the sys_fsync -> do_fsync() checks if the requested file
>> has f_op->fsync defined. If not it returns EINVAL [2].
>>
>> This commit prevents writing error messages for files (devices), which
>> do not support fsync().
>>
>> [1] - http://man7.org/linux/man-pages/man2/fsync.2.html
>> [2] - http://elixir.free-electrons.com/linux/v4.13-rc6/source/fs/sync.c#L183
>>
>> Signed-off-by: Lukasz Majewski <lukma at denx.de>
>> ---
>>  tools/env/fw_env.c | 6 ++++--
>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c
>> index c9c79e0..ab7d85b 100644
>> --- a/tools/env/fw_env.c
>> +++ b/tools/env/fw_env.c
>> @@ -1088,14 +1088,16 @@ static int flash_io (int mode)
>>
>>  		rc = flash_write (fd_current, fd_target, dev_target);
>>
>> -		if (fsync (fd_current)) {
>> +		if (fsync(fd_current) &&
>
> nitpick: current coding style seems to be a single whitespace before
> the opening bracket

I've run the patch through the ./scripts/checkpatch.pl and it was 
complaining about this space, so I've corrected it.

Does the fw_env.c use another coding style (not from the Linux kernel)?

>
>> +		    !(errno == EINVAL || errno == EROFS)) {
>>  			fprintf (stderr,
>>  				 "fsync failed on %s: %s\n",
>>  				 DEVNAME (dev_current), strerror (errno));
>>  		}
>>
>>  		if (HaveRedundEnv) {
>> -			if (fsync (fd_target)) {
>> +			if (fsync(fd_target) &&
>
> dito
>
>> +			    !(errno == EINVAL || errno == EROFS)) {
>>  				fprintf (stderr,
>>  					 "fsync failed on %s: %s\n",
>>  					 DEVNAME (dev_current), strerror (errno));
>
> Other than this nitpick:
>
> Acked-by: Michael Heimpold <mhei at heimpold.de>

Thanks :-)

>
> Regards,
> Michael
>
>


-- 
Best regards,

Lukasz Majewski

--

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