From: Jinpu Wang <jinpu.wang@cloud.ionos.com>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Jack Wang <jinpuwang@gmail.com>,
linux-block@vger.kernel.org, linux-rdma@vger.kernel.org,
Jens Axboe <axboe@kernel.dk>,
Christoph Hellwig <hch@infradead.org>,
Sagi Grimberg <sagi@grimberg.me>,
Jason Gunthorpe <jgg@mellanox.com>,
Doug Ledford <dledford@redhat.com>,
Danil Kipnis <danil.kipnis@cloud.ionos.com>,
rpenyaev@suse.de, Roman Pen <roman.penyaev@profitbricks.com>
Subject: Re: [PATCH v4 15/25] ibnbd: private headers with IBNBD protocol structs and helpers
Date: Sun, 15 Sep 2019 16:30:04 +0200 [thread overview]
Message-ID: <CAMGffEnVFHpmDCiazHFX1jwi4=p401T9goSkes3j1AttV0t1Ng@mail.gmail.com> (raw)
In-Reply-To: <4fbad80b-f551-131e-9a5c-a24f1fa98fea@acm.org>
Thanks Bart for detailed review, reply inline.
On Sat, Sep 14, 2019 at 12:10 AM Bart Van Assche <bvanassche@acm.org> wrote:
>
> On 6/20/19 8:03 AM, Jack Wang wrote:
> > +#define ibnbd_log(fn, dev, fmt, ...) ({ \
> > + __builtin_choose_expr( \
> > + __builtin_types_compatible_p( \
> > + typeof(dev), struct ibnbd_clt_dev *), \
> > + fn("<%s@%s> " fmt, (dev)->pathname, \
> > + (dev)->sess->sessname, \
> > + ##__VA_ARGS__), \
> > + __builtin_choose_expr( \
> > + __builtin_types_compatible_p(typeof(dev), \
> > + struct ibnbd_srv_sess_dev *), \
> > + fn("<%s@%s>: " fmt, (dev)->pathname, \
> > + (dev)->sess->sessname, ##__VA_ARGS__), \
> > + unknown_type())); \
> > +})
>
> Please remove the __builtin_choose_expr() /
> __builtin_types_compatible_p() construct and split this macro into two
> macros or inline functions: one for struct ibnbd_clt_dev and another one
> for struct ibnbd_srv_sess_dev.
Ok, will split to two macros.
>
> > +#define IBNBD_PROTO_VER_MAJOR 2
> > +#define IBNBD_PROTO_VER_MINOR 0
> > +
> > +#define IBNBD_PROTO_VER_STRING __stringify(IBNBD_PROTO_VER_MAJOR) "." \
> > + __stringify(IBNBD_PROTO_VER_MINOR)
> > +
> > +#ifndef IBNBD_VER_STRING
> > +#define IBNBD_VER_STRING __stringify(IBNBD_PROTO_VER_MAJOR) "." \
> > + __stringify(IBNBD_PROTO_VER_MINOR)
>
> Upstream code should not have a version number.
IBNBD_VER_STRING can be removed together with MODULE_VERSION.
>
> > +/* TODO: should be configurable */
> > +#define IBTRS_PORT 1234
>
> How about converting this macro into a kernel module parameter?
Sounds good, will do.
>
> > +enum ibnbd_access_mode {
> > + IBNBD_ACCESS_RO,
> > + IBNBD_ACCESS_RW,
> > + IBNBD_ACCESS_MIGRATION,
> > +};
>
> Some more information about what IBNBD_ACCESS_MIGRATION represents would
> be welcome.
This is a special mode to allow temporarily RW access mode during VM
migration, will add comments next round.
>
> > +#define _IBNBD_FILEIO 0
> > +#define _IBNBD_BLOCKIO 1
> > +#define _IBNBD_AUTOIO 2
> >
> > +enum ibnbd_io_mode {
> > + IBNBD_FILEIO = _IBNBD_FILEIO,
> > + IBNBD_BLOCKIO = _IBNBD_BLOCKIO,
> > + IBNBD_AUTOIO = _IBNBD_AUTOIO,
> > +};
>
> Since the IBNBD_* and _IBNBD_* constants have the same numerical value,
> are the former constants really necessary?
Seems we can remove _IBNBD_*.
>
> > +/**
> > + * struct ibnbd_msg_sess_info - initial session info from client to server
> > + * @hdr: message header
> > + * @ver: IBNBD protocol version
> > + */
> > +struct ibnbd_msg_sess_info {
> > + struct ibnbd_msg_hdr hdr;
> > + u8 ver;
> > + u8 reserved[31];
> > +};
>
> Since the wire protocol is versioned, is it really necessary to add 31
> reserved bytes?
You will never know, we prefer to keep the reserved bytes for future extension,
31 bytes is not much, isn't it?
>
> > +struct ibnbd_msg_sess_info_rsp {
> > + struct ibnbd_msg_hdr hdr;
> > + u8 ver;
> > + u8 reserved[31];
> > +};
>
> Same comment here.
Dito.
>
> > +/**
> > + * struct ibnbd_msg_open_rsp - response message to IBNBD_MSG_OPEN
> > + * @hdr: message header
> > + * @nsectors: number of sectors
>
> What is the size of a single sector?
512b, will mention explicitly in the next round.
>
> > + * @device_id: device_id on server side to identify the device
>
> Please use the same order for the members in the kernel-doc header as in
> the structure.
Ok, will fix
>
> > + * @queue_flags: queue_flags of the device on server side
>
> Where is the queue_flags member?
Oh, will remove it, left over.
>
> > + * @discard_granularity: size of the internal discard allocation unit
> > + * @discard_alignment: offset from internal allocation assignment
> > + * @physical_block_size: physical block size device supports
> > + * @logical_block_size: logical block size device supports
>
> What is the unit for these four members?
will update to be more clear.
>
> > + * @max_segments: max segments hardware support in one transfer
>
> Does 'hardware' refer to the RDMA adapter that transfers the IBNBD
> message or to the storage device? In the latter case, I assume that
> transfer refers to a DMA transaction?
"hardware" refers to the storage device on the server-side.
>
> > + * @io_mode: io_mode device is opened.
>
> Should a reference to enum ibnbd_io_mode be added?
sounds good.
>
> > + u8 __padding[10];
>
> Why ten padding bytes? Does alignment really matter for a data structure
> like this one?
It's more a reserved space for future usage, will rename padding to reserved.
>
> > +/**
> > + * struct ibnbd_msg_io_old - message for I/O read/write for
> > + * ver < IBNBD_PROTO_VER_MAJOR
> > + * This structure is there only to know the size of the "old" message format
> > + * @hdr: message header
> > + * @device_id: device_id on server side to find the right device
> > + * @sector: bi_sector attribute from struct bio
> > + * @rw: bitmask, valid values are defined in enum ibnbd_io_flags
> > + * @bi_size: number of bytes for I/O read/write
> > + * @prio: priority
> > + */
> > +struct ibnbd_msg_io_old {
> > + struct ibnbd_msg_hdr hdr;
> > + __le32 device_id;
> > + __le64 sector;
> > + __le32 rw;
> > + __le32 bi_size;
> > +};
>
> Since this is the first version of IBNBD that is being sent upstream, I
> think that ibnbd_msg_io_old should be left out.
>
> > +
> > +/**
> > + * struct ibnbd_msg_io - message for I/O read/write
> > + * @hdr: message header
> > + * @device_id: device_id on server side to find the right device
> > + * @sector: bi_sector attribute from struct bio
> > + * @rw: bitmask, valid values are defined in enum ibnbd_io_flags
>
> enum ibnbd_io_flags doesn't look like a bitmask but rather like a bit
> field (https://en.wikipedia.org/wiki/Bit_field)?
I will remove the "bitmask", I probably will also rename "rw "to "opf".
>
> > +static inline u32 ibnbd_to_bio_flags(u32 ibnbd_flags)
> > +{
> > + u32 bio_flags;
>
> The names ibnbd_flags and bio_flags are confusing since these two
> variables not only contain flags but also an operation. How about
> changing 'flags' into 'opf' or 'op_flags'?
Sounds good, will change to ibnbd_opf and bio_opf.
>
> > +static inline const char *ibnbd_io_mode_str(enum ibnbd_io_mode mode)
> > +{
> > + switch (mode) {
> > + case IBNBD_FILEIO:
> > + return "fileio";
> > + case IBNBD_BLOCKIO:
> > + return "blockio";
> > + case IBNBD_AUTOIO:
> > + return "autoio";
> > + default:
> > + return "unknown";
> > + }
> > +}
> > +
> > +static inline const char *ibnbd_access_mode_str(enum ibnbd_access_mode mode)
> > +{
> > + switch (mode) {
> > + case IBNBD_ACCESS_RO:
> > + return "ro";
> > + case IBNBD_ACCESS_RW:
> > + return "rw";
> > + case IBNBD_ACCESS_MIGRATION:
> > + return "migration";
> > + default:
> > + return "unknown";
> > + }
> > +}
>
> These two functions are not in the hot path and hence should not be
> inline functions.
Sounds reasonable, will remove the inline.
>
> Note: I plan to review the entire patch series but it may take some time
> before I have finished reviewing the entire patch series.
>
That will be great, thanks a lot, Bart
> Bart.
Regards,
--
Jack Wang
Linux Kernel Developer
Platform Engineering Compute (IONOS Cloud)
1&1 IONOS SE | Greifswalder Str. 207 | 10405 Berlin | Germany
Phone: +49 30 57700-8042 | Fax: +49 30 57700-8598
E-mail: jinpu.wang@cloud.ionos.com | Web: www.ionos.de
next prev parent reply other threads:[~2019-09-15 14:30 UTC|newest]
Thread overview: 148+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-20 15:03 [PATCH v4 00/25] InfiniBand Transport (IBTRS) and Network Block Device (IBNBD) Jack Wang
2019-06-20 15:03 ` [PATCH v4 01/25] sysfs: export sysfs_remove_file_self() Jack Wang
2019-09-23 17:21 ` Bart Van Assche
2019-09-25 9:30 ` Danil Kipnis
2019-06-20 15:03 ` [PATCH v4 02/25] ibtrs: public interface header to establish RDMA connections Jack Wang
2019-09-23 17:44 ` Bart Van Assche
2019-09-25 10:20 ` Danil Kipnis
2019-09-25 15:38 ` Bart Van Assche
2019-06-20 15:03 ` [PATCH v4 03/25] ibtrs: private headers with IBTRS protocol structs and helpers Jack Wang
2019-09-23 22:50 ` Bart Van Assche
2019-09-25 21:45 ` Danil Kipnis
2019-09-25 21:57 ` Bart Van Assche
2019-09-27 8:56 ` Jinpu Wang
2019-06-20 15:03 ` [PATCH v4 04/25] ibtrs: core: lib functions shared between client and server modules Jack Wang
2019-09-23 23:03 ` Bart Van Assche
2019-09-27 10:13 ` Jinpu Wang
2019-06-20 15:03 ` [PATCH v4 05/25] ibtrs: client: private header with client structs and functions Jack Wang
2019-09-23 23:05 ` Bart Van Assche
2019-09-27 10:18 ` Jinpu Wang
2019-06-20 15:03 ` [PATCH v4 06/25] ibtrs: client: main functionality Jack Wang
2019-09-23 21:51 ` Bart Van Assche
2019-09-25 17:36 ` Danil Kipnis
2019-09-25 18:55 ` Bart Van Assche
2019-09-25 20:50 ` Danil Kipnis
2019-09-25 21:08 ` Bart Van Assche
2019-09-25 21:16 ` Bart Van Assche
2019-09-25 22:53 ` Danil Kipnis
2019-09-25 23:21 ` Bart Van Assche
2019-09-26 9:16 ` Danil Kipnis
2019-06-20 15:03 ` [PATCH v4 07/25] ibtrs: client: statistics functions Jack Wang
2019-09-23 23:15 ` Bart Van Assche
2019-09-27 12:00 ` Jinpu Wang
2019-06-20 15:03 ` [PATCH v4 08/25] ibtrs: client: sysfs interface functions Jack Wang
2019-06-20 15:03 ` [PATCH v4 09/25] ibtrs: server: private header with server structs and functions Jack Wang
2019-09-23 23:21 ` Bart Van Assche
2019-09-27 12:04 ` Jinpu Wang
2019-06-20 15:03 ` [PATCH v4 10/25] ibtrs: server: main functionality Jack Wang
2019-09-23 23:49 ` Bart Van Assche
2019-09-27 15:03 ` Jinpu Wang
2019-09-27 15:11 ` Bart Van Assche
2019-09-27 15:19 ` Jinpu Wang
2019-06-20 15:03 ` [PATCH v4 11/25] ibtrs: server: statistics functions Jack Wang
2019-09-23 23:56 ` Bart Van Assche
2019-10-02 15:15 ` Jinpu Wang
2019-10-02 15:42 ` Leon Romanovsky
2019-10-02 15:45 ` Jinpu Wang
2019-10-02 16:00 ` Leon Romanovsky
2019-06-20 15:03 ` [PATCH v4 12/25] ibtrs: server: sysfs interface functions Jack Wang
2019-09-24 0:00 ` Bart Van Assche
2019-10-02 15:11 ` Jinpu Wang
2019-06-20 15:03 ` [PATCH v4 13/25] ibtrs: include client and server modules into kernel compilation Jack Wang
2019-06-20 15:03 ` [PATCH v4 14/25] ibtrs: a bit of documentation Jack Wang
2019-06-20 15:03 ` [PATCH v4 15/25] ibnbd: private headers with IBNBD protocol structs and helpers Jack Wang
2019-09-13 22:10 ` Bart Van Assche
2019-09-15 14:30 ` Jinpu Wang [this message]
2019-09-16 5:27 ` Leon Romanovsky
2019-09-16 13:45 ` Bart Van Assche
2019-09-17 15:41 ` Leon Romanovsky
2019-09-17 15:52 ` Jinpu Wang
2019-09-16 7:08 ` Danil Kipnis
2019-09-16 14:57 ` Jinpu Wang
2019-09-16 17:25 ` Bart Van Assche
2019-09-17 12:27 ` Jinpu Wang
2019-09-16 15:39 ` Jinpu Wang
2019-09-18 15:26 ` Bart Van Assche
2019-09-18 16:11 ` Jinpu Wang
2019-06-20 15:03 ` [PATCH v4 16/25] ibnbd: client: private header with client structs and functions Jack Wang
2019-09-13 22:25 ` Bart Van Assche
2019-09-17 16:36 ` Jinpu Wang
2019-09-25 23:43 ` Danil Kipnis
2019-09-26 10:00 ` Jinpu Wang
2019-06-20 15:03 ` [PATCH v4 17/25] ibnbd: client: main functionality Jack Wang
2019-09-13 23:46 ` Bart Van Assche
2019-09-16 14:17 ` Danil Kipnis
2019-09-16 16:46 ` Bart Van Assche
2019-09-17 11:39 ` Danil Kipnis
2019-09-18 7:14 ` Danil Kipnis
2019-09-18 15:47 ` Bart Van Assche
2019-09-20 8:29 ` Danil Kipnis
2019-09-25 22:26 ` Danil Kipnis
2019-09-26 9:55 ` Roman Penyaev
2019-09-26 15:01 ` Bart Van Assche
2019-09-27 8:52 ` Roman Penyaev
2019-09-27 9:32 ` Danil Kipnis
2019-09-27 12:18 ` Danil Kipnis
2019-09-27 16:37 ` Bart Van Assche
2019-09-27 16:50 ` Roman Penyaev
2019-09-27 17:16 ` Bart Van Assche
2019-09-17 13:09 ` Jinpu Wang
2019-09-17 16:46 ` Bart Van Assche
2019-09-18 12:02 ` Jinpu Wang
2019-09-18 16:05 ` Jinpu Wang
2019-09-14 0:00 ` Bart Van Assche
2019-06-20 15:03 ` [PATCH v4 18/25] ibnbd: client: sysfs interface functions Jack Wang
2019-09-18 16:28 ` Bart Van Assche
2019-09-19 15:55 ` Jinpu Wang
2019-06-20 15:03 ` [PATCH v4 19/25] ibnbd: server: private header with server structs and functions Jack Wang
2019-06-20 15:03 ` [PATCH v4 20/25] ibnbd: server: main functionality Jack Wang
2019-09-18 17:41 ` Bart Van Assche
2019-09-20 7:36 ` Danil Kipnis
2019-09-20 15:42 ` Bart Van Assche
2019-09-23 15:19 ` Danil Kipnis
2019-06-20 15:03 ` [PATCH v4 21/25] ibnbd: server: functionality for IO submission to file or block dev Jack Wang
2019-09-18 21:46 ` Bart Van Assche
2019-09-26 14:04 ` Jinpu Wang
2019-09-26 15:11 ` Bart Van Assche
2019-09-26 15:25 ` Danil Kipnis
2019-09-26 15:29 ` Bart Van Assche
2019-09-26 15:38 ` Danil Kipnis
2019-09-26 15:42 ` Jinpu Wang
2019-06-20 15:03 ` [PATCH v4 22/25] ibnbd: server: sysfs interface functions Jack Wang
2019-06-20 15:03 ` [PATCH v4 23/25] ibnbd: include client and server modules into kernel compilation Jack Wang
2019-06-20 15:03 ` [PATCH v4 24/25] ibnbd: a bit of documentation Jack Wang
2019-09-13 23:58 ` Bart Van Assche
2019-09-18 12:22 ` Jinpu Wang
2019-06-20 15:03 ` [PATCH v4 25/25] MAINTAINERS: Add maintainer for IBNBD/IBTRS modules Jack Wang
2019-07-09 15:10 ` Leon Romanovsky
2019-07-09 15:18 ` Jinpu Wang
2019-07-09 15:51 ` Leon Romanovsky
2019-09-13 23:56 ` Bart Van Assche
2019-09-19 10:30 ` Jinpu Wang
2019-07-09 9:55 ` [PATCH v4 00/25] InfiniBand Transport (IBTRS) and Network Block Device (IBNBD) Danil Kipnis
2019-07-09 11:00 ` Leon Romanovsky
2019-07-09 11:17 ` Greg KH
2019-07-09 11:57 ` Jinpu Wang
2019-07-09 13:32 ` Leon Romanovsky
2019-07-09 15:39 ` Bart Van Assche
2019-07-09 11:37 ` Jinpu Wang
2019-07-09 12:06 ` Jason Gunthorpe
2019-07-09 13:15 ` Jinpu Wang
2019-07-09 13:19 ` Jason Gunthorpe
2019-07-09 14:17 ` Jinpu Wang
2019-07-09 21:27 ` Sagi Grimberg
2019-07-19 13:12 ` Danil Kipnis
2019-07-10 14:55 ` Danil Kipnis
2019-07-09 12:04 ` Jason Gunthorpe
2019-07-09 19:45 ` Sagi Grimberg
2019-07-10 13:55 ` Jason Gunthorpe
2019-07-10 16:25 ` Sagi Grimberg
2019-07-10 17:25 ` Jason Gunthorpe
2019-07-10 19:11 ` Sagi Grimberg
2019-07-11 7:27 ` Danil Kipnis
2019-07-11 8:54 ` Danil Kipnis
2019-07-12 0:22 ` Sagi Grimberg
2019-07-12 7:57 ` Jinpu Wang
2019-07-12 19:40 ` Sagi Grimberg
2019-07-15 11:21 ` Jinpu Wang
2019-07-12 10:58 ` Danil Kipnis
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