[PATCH] mtd: partitions: Handle add_mtd_device() failures gracefully
Marek Vasut
marek.vasut at gmail.com
Tue Apr 10 07:37:40 PDT 2018
On 04/10/2018 03:26 PM, Geert Uytterhoeven wrote:
> Hi Marek,
>
> On Mon, Apr 9, 2018 at 11:59 PM, Marek Vasut <marek.vasut at gmail.com> wrote:
>> On 04/09/2018 02:25 PM, Geert Uytterhoeven wrote:
>>> Currently add_mtd_device() failures are plainly ignored, which may lead
>>> to kernel crashes later.
>
>>> Fix this by ignoring and freeing partitions that failed to add in
>>> add_mtd_partitions(). The same issue is present in mtd_add_partition(),
>>> so fix that as well.
>>>
>>> Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
>>> ---
>>> I don't know if it is worthwhile factoring out the common handling.
>>>
>>> Should allocate_partition() fail instead? There's a comment saying
>>> "let's register it anyway to preserve ordering".
>
>>> --- a/drivers/mtd/mtdpart.c
>>> +++ b/drivers/mtd/mtdpart.c
>
>>> @@ -746,7 +753,15 @@ int add_mtd_partitions(struct mtd_info *master,
>>> list_add(&slave->list, &mtd_partitions);
>>> mutex_unlock(&mtd_partitions_mutex);
>>>
>>> - add_mtd_device(&slave->mtd);
>>> + ret = add_mtd_device(&slave->mtd);
>>> + if (ret) {
>>> + mutex_lock(&mtd_partitions_mutex);
>>> + list_del(&slave->list);
>>> + mutex_unlock(&mtd_partitions_mutex);
>>> + free_partition(slave);
>>> + continue;
>>> + }
>>
>> Why is the partition even in the list in the first place ? Can we avoid
>> adding it rather than adding and removing it ?
>
> Hence my question "Should allocate_partition() fail instead?".
> Note that if we go that route, it should be a "soft" failure, as we
> probably don't
> want to drop all other partitions on the device.
Is the number of partitions ie. in /proc/mtdparts an ABI ?
--
Best regards,
Marek Vasut
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