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From:   Damien Le Moal <Damien.LeMoal@wdc.com>
To:     Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
        Bart Van Assche <bvanassche@acm.org>,
        =?iso-8859-1?Q?Matias_Bj=F8rling?= <mb@lightnvm.io>,
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        Ajay Joshi <Ajay.Joshi@wdc.com>,
        Aravind Ramesh <Aravind.Ramesh@wdc.com>,
        "martin.petersen@oracle.com" <martin.petersen@oracle.com>,
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        <James.Bottomley@HansenPartnership.com>,
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        Matias Bjorling <Matias.Bjorling@wdc.com>
Subject: Re: [PATCH 1/4] block: add zone open, close and finish support
Thread-Topic: [PATCH 1/4] block: add zone open, close and finish support
Thread-Index: AQHVKDJPztuCEJ+OF0q7RsgYaqLWMQ==
Date:   Wed, 26 Jun 2019 00:44:34 +0000
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On 2019/06/26 1:51, Chaitanya Kulkarni wrote:=0A=
> On 06/25/2019 08:56 AM, Bart Van Assche wrote:=0A=
>> On 6/25/19 3:35 AM, Matias Bj=F8rling wrote:=0A=
>>> On 6/25/19 12:27 AM, Chaitanya Kulkarni wrote:=0A=
>>>> On 6/24/19 12:43 PM, Bart Van Assche wrote:=0A=
>>>>> static inline bool op_is_write(unsigned int op)=0A=
>>>>> {=0A=
>>>>>      return (op & 1);=0A=
>>>>> }=0A=
>>>>>=0A=
>>>>=0A=
>>>=0A=
>>> The zone mgmt commands are neither write nor reads commands. I guess,=
=0A=
>>> one could characterize them as write commands, but they don't write any=
=0A=
>>> data, they update a state of a zone on a drive. One should keep it as=
=0A=
>>> is? and make sure the zone mgmt commands don't get categorized as eithe=
r=0A=
>>> read/write.=0A=
>>=0A=
>> Since the open, close and finish operations support modifying zone data=
=0A=
>> I propose to characterize these as write commands. How about the=0A=
>> following additional changes:=0A=
>> - Make bio_check_ro() refuse open/close/flush/reset zone operations for=
=0A=
>                                           ^=0A=
> Since finish also listed above which supports modifying data do we need =
=0A=
> to add finish here with flush in above line ?=0A=
=0A=
There is no "zone flush" operation. I guess Bart made a typo here and meant=
=0A=
"finish". "flush" on a zoned disk is not different from regular disks.=0A=
=0A=
> =0A=
>> read-only partitions (see also commit a32e236eb93e ("Partially revert=0A=
>> "block: fail op_is_write() requests to read-only partitions"") # v4.18).=
=0A=
>> - In submit_bio(), change op_is_write(bio_op(bio)) ? "WRITE" : "READ"=0A=
>> into something that uses blk_op_str().=0A=
> Good idea, I've a patch for blk_op_str() and debugfs just waiting for =0A=
> this to merge. Does it make sense to add that patch in this series ?=0A=
>> - Add open/close/flush zone support be added in blk_partition_remap().=
=0A=
> same here for finish ?=0A=
>>=0A=
>> Thanks,=0A=
>>=0A=
>> Bart.=0A=
>>=0A=
> =0A=
> =0A=
=0A=
=0A=
-- =0A=
Damien Le Moal=0A=
Western Digital Research=0A=