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Subject: Re: [PATCH v5] mm: cma: support sysfs
From:   Dmitry Osipenko <digetx@gmail.com>
To:     Minchan Kim <minchan@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     linux-mm <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>,
        gregkh@linuxfoundation.org, surenb@google.com, joaodias@google.com,
        jhubbard@nvidia.com, willy@infradead.org
References: <20210323195050.2577017-1-minchan@kernel.org>
 <bff2b424-91f7-5748-fa27-54cc75667548@gmail.com>
Message-ID: <dfa57d3c-6aa0-d771-8c78-91ec0c42c7b5@gmail.com>
Date:   Wed, 24 Mar 2021 00:29:09 +0300
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24.03.2021 00:19, Dmitry Osipenko пишет:
>> +		if (!kobj)
>> +			goto out;
>> +
>> +		kobj->cma = cma;
>> +		cma->kobj = kobj;
>> +		if (kobject_init_and_add(&cma->kobj->kobj, &cma_ktype,
>> +					 cma_kobj_root, "%s", cma->name)) {
>> +			kobject_put(&cma->kobj->kobj);
>> +			goto out;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +out:
>> +	kobject_put(cma_kobj_root);
>> +
>> +	return -ENOMEM;
> kobject_init_and_add returns a error code, it could be different from
> ENOMEM. Won't hurt to propagate the proper error code.
> 

I think it will be cleaner to write it like this:

		cma_kobj = kzalloc(sizeof(*cma_kobj), GFP_KERNEL);
		if (!cma_kobj) {
			kobject_put(cma_kobj_root);
			return -ENOMEM;
		}

		cma_kobj->cma = cma;

		err = kobject_init_and_add(&cma_kobj->kobj, &cma_ktype,
					   cma_kobj_root, "%s", cma->name);		   
		if (err) {
			kobject_put(&cma_kobj->kobj);
			kobject_put(cma_kobj_root);
			return err;
		}
	}

	return 0;
}