On 2/3/22 12:24 AM, Hannes Reinecke wrote:
> On 2/3/22 07:52, Song Liu wrote:
>> CC linux-block (it was a typo in the original email)
>>
>> On Wed, Feb 2, 2022 at 10:40 PM Song Liu <song@xxxxxxxxxx> wrote:
>>>
>>> Currently, drivers reports BLK_STS_IOERR for devices that are not full
>>> online or being removed. This behavior could cause confusion for users,
>>> as they are not really I/O errors from the device.
>>>
>>> Solve this issue with a new state BLK_STS_OFFLINE, which reports "device
>>> offline error" in dmesg instead of "I/O error".
>>>
>>> Signed-off-by: Song Liu <song@xxxxxxxxxx>
>>> ---
>>> block/blk-core.c | 1 +
>>> include/linux/blk_types.h | 7 +++++++
>>> 2 files changed, 8 insertions(+)
>>>
>>> diff --git a/block/blk-core.c b/block/blk-core.c
>>> index 61f6a0dc4511..24035dd2eef1 100644
>>> --- a/block/blk-core.c
>>> +++ b/block/blk-core.c
>>> @@ -164,6 +164,7 @@ static const struct {
>>> [BLK_STS_RESOURCE] = { -ENOMEM, "kernel resource" },
>>> [BLK_STS_DEV_RESOURCE] = { -EBUSY, "device resource" },
>>> [BLK_STS_AGAIN] = { -EAGAIN, "nonblocking retry" },
>>> + [BLK_STS_OFFLINE] = { -EIO, "device offline" },
>>>
>>> /* device mapper special case, should not leak out: */
>>> [BLK_STS_DM_REQUEUE] = { -EREMCHG, "dm internal retry" },
>>> diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
>>> index fe065c394fff..5561e58d158a 100644
>>> --- a/include/linux/blk_types.h
>>> +++ b/include/linux/blk_types.h
>>> @@ -153,6 +153,13 @@ typedef u8 __bitwise blk_status_t;
>>> */
>>> #define BLK_STS_ZONE_ACTIVE_RESOURCE ((__force blk_status_t)16)
>>>
>>> +/*
>>> + * BLK_STS_OFFLINE is returned from the driver when the target device is offline
>>> + * or is being taken offline. This could help differentiate the case where a
>>> + * device is intentionally being shut down from a real I/O error.
>>> + */
>>> +#define BLK_STS_OFFLINE ((__force blk_status_t)17)
>>> +
>>> /**
>>> * blk_path_error - returns true if error may be path related
>>> * @error: status the request was completed with
>>> --
>>> 2.30.2
>>>
> Please do not overload EIO here.
> EIO already is a catch-all error if we don't know any better, but for
> the 'device offline' case we do (or rather should).
> Please map it onto 'ENODEV' or 'ENXIO'.
It's deliberately EIO as not to force a change in behavior. I don't mind
using something else, but that should be a separate change then.
--
Jens Axboe
