From: Ashish Sangwan <ashishsangwan2@gmail.com>
Subject: Re: [PATCH] ext4: add error handling when discard cmd is fail in FITRIM
Date: Wed, 1 Aug 2012 12:17:43 +0530
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Cc: Namjae Jeon <linkinjeon@gmail.com>, tytso@mit.edu,
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>> How about instead of propagating the error to user and breaking out of
>> the discard, just print a warning message like:
>> ext4_warning(sb, "error %d while trimming group block from %d to
>> %d\n",ret, start, next);
>
> That's what I said. I think that those errors should be logged, but
> I am not sure that doing it on fs level is such a good idea. Do you
> see any errors in the logs when the discard command fails ?
>
Ok, I understand your point. Discard errors should be logged at block
layer. Reasonable too.
This is already happening. In case of discard error:
#> ./fitrim_test
end_request: I/O error, dev mmcblk0, sector 27232
#>
#> echo $?
0
Even though error happend during discard, the return value is success.
I think this is little confusing.

Thanks,
Ashish