Re: [PATCH] block: add command line partition parser

2013-08-15 Thread Brian Norris

On 08/15/2013 12:45 AM, Caizhiyong wrote:

-Original Message-
From: Brian Norris [mailto:computersforpe...@gmail.com]

...

On Thu, Aug 15, 2013 at 06:16:04AM +, Caizhiyong wrote:

I want to use the MTD command line partition method on block devices (eMMC).
It is very suitable for embedded systems. I think, in embedded system partition

method,

if somebody need some feature on MTD device, he may be also need it on block 
device.
so I fully functional reference MTD command line partition.


I agree.

I'm curious: have you seen any need for a similar arrangement via
device-tree? See, for example, drivers/mtd/ofpart.c.


So far, I have no seen. We mainly use ARM. For ARM, device-tree is a new thing.


But device-tree is *the* thing for ARM going forward, and the kernel 
command line can get unwieldy (and beyond its limits) pretty quickly 
like this.



I hope extend the flexibility to block device.


Sure. I'll try to review the full patch soon and test out integrating
it with MTD.


If there is no problem, I will send my next patch, mtd cmdline parts use 
cmdline-parser lib.


We will get some reviews on this soon (no time for me tonight). Do you 
already have a mtd patch? If so, you might as well post it for review as 
well.


Thanks,
Brian
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RE: [PATCH] block: add command line partition parser

2013-08-15 Thread Caizhiyong
> -Original Message-
> From: Brian Norris [mailto:computersforpe...@gmail.com]
> Sent: Thursday, August 15, 2013 3:10 PM
> To: Caizhiyong
> Cc: Andrew Morton; Karel Zak; linux-...@lists.infradead.org;
> linux-kernel@vger.kernel.org; Wanglin (Albert); Artem Bityutskiy; Shmulik 
> Ladkani;
> Huang Shijie
> Subject: Re: [PATCH] block: add command line partition parser
> 
> On Thu, Aug 15, 2013 at 06:16:04AM +, Caizhiyong wrote:
> > > -Original Message-
> > > From: Brian Norris [mailto:computersforpe...@gmail.com]
> > > Sent: Thursday, August 15, 2013 1:00 PM
> > > To: Caizhiyong
> > > Cc: Andrew Morton; Karel Zak; linux-...@lists.infradead.org;
> > > linux-kernel@vger.kernel.org; Wanglin (Albert); Artem Bityutskiy; Shmulik
> Ladkani;
> > > Huang Shijie
> > > Subject: Re: [PATCH] block: add command line partition parser
> > >
> > > On Thu, Aug 15, 2013 at 03:38:47AM +, Caizhiyong wrote:
> > > > > -Original Message-
> > > > > From: Brian Norris [mailto:computersforpe...@gmail.com]
> > > > > Sent: Thursday, August 15, 2013 8:12 AM
> > > > > To: Andrew Morton
> > > > > Cc: Caizhiyong; Karel Zak; linux-...@lists.infradead.org;
> > > > > linux-kernel@vger.kernel.org; Wanglin (Albert); Artem Bityutskiy; 
> > > > > Shmulik
> > > Ladkani;
> > > > > Huang Shijie
> > > > > Subject: Re: [PATCH] block: add command line partition parser
> > > > >
> > > > > On Wed, Aug 14, 2013 at 3:57 PM, Andrew Morton
> > > > >  wrote:
> > > > > > On Tue, 13 Aug 2013 06:02:17 + Caizhiyong 
> > > > > > 
> wrote:
> > > > > >
> > > > > >> move the command line parser to a separate module, and change it 
> > > > > >> into
> > > > > >> library-style code.
> > > > > >>
> > > > > >> reference: https://lkml.org/lkml/2013/8/6/550
> > > > >
> > > > > The most recent patch is an addendum to this linked patch then?
> > > > >
> > > > > > Well OK.  But to prove the library's usefulness and to generally 
> > > > > > clean
> > > > > > up the kernel, someone needs to sign up to the task of converting
> > > > > > drivers/mtd/cmdlinepart.c to use this code.
> > > > > >
> > > > > > I've been hopefully cc'ing various MTD people but am not being
> > > > > > overwhelmed with waves of enthusiasm ;)
> > > > >
> > > > > "I've been" implies that you have done so prior to this email. And
> > > > > "people" implies more than one person. I see that you CC'd David
> > > > > Woodhouse over a week ago, but he's fairly silent these days on MTD
> > > > > things. It's Artem or me who handle most of the day-to-day of MTD. And
> > > > > this is the first time I've seen this! (BTW, please include
> > > > > linux-...@lists.infradead.org for anything involving MTD.)
> > > > >
> > > > > This seems reasonable, and I'd be willing to work with this proposal.
> > > > >
> > > > > Caizhiyong, can you submit a clear single patch (or series of
> > > > > patches), CC'd to linux-mtd at least? Then we can see about supporting
> > > > > it in MTD. It doesn't look too difficult, but I need to check that it
> > > > > faithfully mimics the capability we currently rely on. There have been
> > > > > previous discussions on changing it, but this was rejected in favor of
> > > > > allowing more flexibility. Here's part of one such conversation:
> > > > >
> > > > > http://lists.infradead.org/pipermail/linux-mtd/2012-August/043599.html
> > > > >
> http://lists.infradead.org/pipermail/linux-mtd/2012-September/043825.html
> > > > > http://lists.infradead.org/pipermail/linux-mtd/2012-December/045322.html
> > > > >
> > > > > So I would recommend:
> > > > > (1) consider carefully the implications of your command-line format
> > > > > now, rather than later
> > > > > (2) if you want MTD to use it, it needs to support the features we 
> > > > > use now
> > > >
> > > > It is fully functional reference MTD, :-).
> > >
> > >

Re: [PATCH] block: add command line partition parser

2013-08-15 Thread Brian Norris
On Thu, Aug 15, 2013 at 06:16:04AM +, Caizhiyong wrote:
> > -Original Message-
> > From: Brian Norris [mailto:computersforpe...@gmail.com]
> > Sent: Thursday, August 15, 2013 1:00 PM
> > To: Caizhiyong
> > Cc: Andrew Morton; Karel Zak; linux-...@lists.infradead.org;
> > linux-kernel@vger.kernel.org; Wanglin (Albert); Artem Bityutskiy; Shmulik 
> > Ladkani;
> > Huang Shijie
> > Subject: Re: [PATCH] block: add command line partition parser
> > 
> > On Thu, Aug 15, 2013 at 03:38:47AM +, Caizhiyong wrote:
> > > > -Original Message-
> > > > From: Brian Norris [mailto:computersforpe...@gmail.com]
> > > > Sent: Thursday, August 15, 2013 8:12 AM
> > > > To: Andrew Morton
> > > > Cc: Caizhiyong; Karel Zak; linux-...@lists.infradead.org;
> > > > linux-kernel@vger.kernel.org; Wanglin (Albert); Artem Bityutskiy; 
> > > > Shmulik
> > Ladkani;
> > > > Huang Shijie
> > > > Subject: Re: [PATCH] block: add command line partition parser
> > > >
> > > > On Wed, Aug 14, 2013 at 3:57 PM, Andrew Morton
> > > >  wrote:
> > > > > On Tue, 13 Aug 2013 06:02:17 + Caizhiyong  
> > > > > wrote:
> > > > >
> > > > >> move the command line parser to a separate module, and change it into
> > > > >> library-style code.
> > > > >>
> > > > >> reference: https://lkml.org/lkml/2013/8/6/550
> > > >
> > > > The most recent patch is an addendum to this linked patch then?
> > > >
> > > > > Well OK.  But to prove the library's usefulness and to generally clean
> > > > > up the kernel, someone needs to sign up to the task of converting
> > > > > drivers/mtd/cmdlinepart.c to use this code.
> > > > >
> > > > > I've been hopefully cc'ing various MTD people but am not being
> > > > > overwhelmed with waves of enthusiasm ;)
> > > >
> > > > "I've been" implies that you have done so prior to this email. And
> > > > "people" implies more than one person. I see that you CC'd David
> > > > Woodhouse over a week ago, but he's fairly silent these days on MTD
> > > > things. It's Artem or me who handle most of the day-to-day of MTD. And
> > > > this is the first time I've seen this! (BTW, please include
> > > > linux-...@lists.infradead.org for anything involving MTD.)
> > > >
> > > > This seems reasonable, and I'd be willing to work with this proposal.
> > > >
> > > > Caizhiyong, can you submit a clear single patch (or series of
> > > > patches), CC'd to linux-mtd at least? Then we can see about supporting
> > > > it in MTD. It doesn't look too difficult, but I need to check that it
> > > > faithfully mimics the capability we currently rely on. There have been
> > > > previous discussions on changing it, but this was rejected in favor of
> > > > allowing more flexibility. Here's part of one such conversation:
> > > >
> > > > http://lists.infradead.org/pipermail/linux-mtd/2012-August/043599.html
> > > > http://lists.infradead.org/pipermail/linux-mtd/2012-September/043825.html
> > > > http://lists.infradead.org/pipermail/linux-mtd/2012-December/045322.html
> > > >
> > > > So I would recommend:
> > > > (1) consider carefully the implications of your command-line format
> > > > now, rather than later
> > > > (2) if you want MTD to use it, it needs to support the features we use 
> > > > now
> > >
> > > It is fully functional reference MTD, :-).
> > 
> > I realize that. I just want to be clear that we have to reconcile (1)
> > and (2). IOW, if block device requirements stray too far from MTD
> > requirements, then we might as well drop the idea of integration now.
> > But if they agree, then we can move forward.
> > 
> > > > Some particular cases to consider: overlapping partitions (how do
> > > > block devices handle overlapping partitions?), out-of-order
> > > > specification, zero sized partitions, mixed syntax (some specified
> > > > with an offset, some not), multiple '-' partitions.
> > >
> > > I think the 'offset' just is used to hide some MTD space.
> > 
> > No, it specifies offset as a distance from the beginning of the flash,
> > so parti

RE: [PATCH] block: add command line partition parser

2013-08-14 Thread Caizhiyong
> -Original Message-
> From: Brian Norris [mailto:computersforpe...@gmail.com]
> Sent: Thursday, August 15, 2013 1:00 PM
> To: Caizhiyong
> Cc: Andrew Morton; Karel Zak; linux-...@lists.infradead.org;
> linux-kernel@vger.kernel.org; Wanglin (Albert); Artem Bityutskiy; Shmulik 
> Ladkani;
> Huang Shijie
> Subject: Re: [PATCH] block: add command line partition parser
> 
> On Thu, Aug 15, 2013 at 03:38:47AM +, Caizhiyong wrote:
> > > -Original Message-
> > > From: Brian Norris [mailto:computersforpe...@gmail.com]
> > > Sent: Thursday, August 15, 2013 8:12 AM
> > > To: Andrew Morton
> > > Cc: Caizhiyong; Karel Zak; linux-...@lists.infradead.org;
> > > linux-kernel@vger.kernel.org; Wanglin (Albert); Artem Bityutskiy; Shmulik
> Ladkani;
> > > Huang Shijie
> > > Subject: Re: [PATCH] block: add command line partition parser
> > >
> > > On Wed, Aug 14, 2013 at 3:57 PM, Andrew Morton
> > >  wrote:
> > > > On Tue, 13 Aug 2013 06:02:17 + Caizhiyong  
> > > > wrote:
> > > >
> > > >> move the command line parser to a separate module, and change it into
> > > >> library-style code.
> > > >>
> > > >> reference: https://lkml.org/lkml/2013/8/6/550
> > >
> > > The most recent patch is an addendum to this linked patch then?
> > >
> > > > Well OK.  But to prove the library's usefulness and to generally clean
> > > > up the kernel, someone needs to sign up to the task of converting
> > > > drivers/mtd/cmdlinepart.c to use this code.
> > > >
> > > > I've been hopefully cc'ing various MTD people but am not being
> > > > overwhelmed with waves of enthusiasm ;)
> > >
> > > "I've been" implies that you have done so prior to this email. And
> > > "people" implies more than one person. I see that you CC'd David
> > > Woodhouse over a week ago, but he's fairly silent these days on MTD
> > > things. It's Artem or me who handle most of the day-to-day of MTD. And
> > > this is the first time I've seen this! (BTW, please include
> > > linux-...@lists.infradead.org for anything involving MTD.)
> > >
> > > This seems reasonable, and I'd be willing to work with this proposal.
> > >
> > > Caizhiyong, can you submit a clear single patch (or series of
> > > patches), CC'd to linux-mtd at least? Then we can see about supporting
> > > it in MTD. It doesn't look too difficult, but I need to check that it
> > > faithfully mimics the capability we currently rely on. There have been
> > > previous discussions on changing it, but this was rejected in favor of
> > > allowing more flexibility. Here's part of one such conversation:
> > >
> > > http://lists.infradead.org/pipermail/linux-mtd/2012-August/043599.html
> > > http://lists.infradead.org/pipermail/linux-mtd/2012-September/043825.html
> > > http://lists.infradead.org/pipermail/linux-mtd/2012-December/045322.html
> > >
> > > So I would recommend:
> > > (1) consider carefully the implications of your command-line format
> > > now, rather than later
> > > (2) if you want MTD to use it, it needs to support the features we use now
> >
> > It is fully functional reference MTD, :-).
> 
> I realize that. I just want to be clear that we have to reconcile (1)
> and (2). IOW, if block device requirements stray too far from MTD
> requirements, then we might as well drop the idea of integration now.
> But if they agree, then we can move forward.
> 
> > > Some particular cases to consider: overlapping partitions (how do
> > > block devices handle overlapping partitions?), out-of-order
> > > specification, zero sized partitions, mixed syntax (some specified
> > > with an offset, some not), multiple '-' partitions.
> >
> > I think the 'offset' just is used to hide some MTD space.
> 
> No, it specifies offset as a distance from the beginning of the flash,
> so partitions can be numbered out of order. This is intentionally
> utilized by some users, for example, to ensure that a particular
> partition is always /dev/mtd0, even if it is not the first partition
> physically.
> 
> > There are two way:
> > 1) redefine the 'offset' as a gap between forward partition and next 
> > partition.
> > 2) add code forbid command line partitions overlapping and out-of-order.
> >
> > I recommend 1), it seems to solve th

Re: [PATCH] block: add command line partition parser

2013-08-14 Thread Brian Norris
On Thu, Aug 15, 2013 at 03:38:47AM +, Caizhiyong wrote:
> > -Original Message-
> > From: Brian Norris [mailto:computersforpe...@gmail.com]
> > Sent: Thursday, August 15, 2013 8:12 AM
> > To: Andrew Morton
> > Cc: Caizhiyong; Karel Zak; linux-...@lists.infradead.org;
> > linux-kernel@vger.kernel.org; Wanglin (Albert); Artem Bityutskiy; Shmulik 
> > Ladkani;
> > Huang Shijie
> > Subject: Re: [PATCH] block: add command line partition parser
> > 
> > On Wed, Aug 14, 2013 at 3:57 PM, Andrew Morton
> >  wrote:
> > > On Tue, 13 Aug 2013 06:02:17 + Caizhiyong  
> > > wrote:
> > >
> > >> move the command line parser to a separate module, and change it into
> > >> library-style code.
> > >>
> > >> reference: https://lkml.org/lkml/2013/8/6/550
> > 
> > The most recent patch is an addendum to this linked patch then?
> > 
> > > Well OK.  But to prove the library's usefulness and to generally clean
> > > up the kernel, someone needs to sign up to the task of converting
> > > drivers/mtd/cmdlinepart.c to use this code.
> > >
> > > I've been hopefully cc'ing various MTD people but am not being
> > > overwhelmed with waves of enthusiasm ;)
> > 
> > "I've been" implies that you have done so prior to this email. And
> > "people" implies more than one person. I see that you CC'd David
> > Woodhouse over a week ago, but he's fairly silent these days on MTD
> > things. It's Artem or me who handle most of the day-to-day of MTD. And
> > this is the first time I've seen this! (BTW, please include
> > linux-...@lists.infradead.org for anything involving MTD.)
> > 
> > This seems reasonable, and I'd be willing to work with this proposal.
> > 
> > Caizhiyong, can you submit a clear single patch (or series of
> > patches), CC'd to linux-mtd at least? Then we can see about supporting
> > it in MTD. It doesn't look too difficult, but I need to check that it
> > faithfully mimics the capability we currently rely on. There have been
> > previous discussions on changing it, but this was rejected in favor of
> > allowing more flexibility. Here's part of one such conversation:
> > 
> > http://lists.infradead.org/pipermail/linux-mtd/2012-August/043599.html
> > http://lists.infradead.org/pipermail/linux-mtd/2012-September/043825.html
> > http://lists.infradead.org/pipermail/linux-mtd/2012-December/045322.html
> > 
> > So I would recommend:
> > (1) consider carefully the implications of your command-line format
> > now, rather than later
> > (2) if you want MTD to use it, it needs to support the features we use now
> 
> It is fully functional reference MTD, :-).

I realize that. I just want to be clear that we have to reconcile (1)
and (2). IOW, if block device requirements stray too far from MTD
requirements, then we might as well drop the idea of integration now.
But if they agree, then we can move forward.

> > Some particular cases to consider: overlapping partitions (how do
> > block devices handle overlapping partitions?), out-of-order
> > specification, zero sized partitions, mixed syntax (some specified
> > with an offset, some not), multiple '-' partitions.
> 
> I think the 'offset' just is used to hide some MTD space.

No, it specifies offset as a distance from the beginning of the flash,
so partitions can be numbered out of order. This is intentionally
utilized by some users, for example, to ensure that a particular
partition is always /dev/mtd0, even if it is not the first partition
physically.

> There are two way:
> 1) redefine the 'offset' as a gap between forward partition and next 
> partition.
> 2) add code forbid command line partitions overlapping and out-of-order.
> 
> I recommend 1), it seems to solve those problem(overlapping and 
> out-of-order), but it will affect habit.

The linked discussion is where MTD settled on retaining old practice. I
brought it up not so that we change it here, but so that you would
understand what you are agreeing to if you adopt a common MTD and block
device parsing infrastructure.

[Note that I am much less familiar with block device mechanics than with
MTD.] Are any of the problem areas I mentioned actually forbidden on
block devices? I know, for instance, that an MBR partition table can
specify partitions out of order. And I've googled around and seen some
posts about people (unintentionally) ending up with overlapping hard
disk partitions.

So from my primitive knowledge, it sounds like a block devices parser
could agree with the same principle put forward by Shmulik in that
second URL:

 "So far, mtdparts commandline parsing has been very lenient and liberal.
  I think we should keep this approach; give the user the flexibility,
  he'll be responsible to provide meaningful cmdline parts for his
  system."

Brian
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To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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More majordomo info at  http://vger.kernel.org/majordomo-info.html
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RE: [PATCH] block: add command line partition parser

2013-08-14 Thread Caizhiyong
> -Original Message-
> From: Brian Norris [mailto:computersforpe...@gmail.com]
> Sent: Thursday, August 15, 2013 8:12 AM
> To: Andrew Morton
> Cc: Caizhiyong; Karel Zak; linux-...@lists.infradead.org;
> linux-kernel@vger.kernel.org; Wanglin (Albert); Artem Bityutskiy; Shmulik 
> Ladkani;
> Huang Shijie
> Subject: Re: [PATCH] block: add command line partition parser
> 
> On Wed, Aug 14, 2013 at 3:57 PM, Andrew Morton
>  wrote:
> > On Tue, 13 Aug 2013 06:02:17 + Caizhiyong  wrote:
> >
> >> move the command line parser to a separate module, and change it into
> >> library-style code.
> >>
> >> reference: https://lkml.org/lkml/2013/8/6/550
> 
> The most recent patch is an addendum to this linked patch then?
> 
> > Well OK.  But to prove the library's usefulness and to generally clean
> > up the kernel, someone needs to sign up to the task of converting
> > drivers/mtd/cmdlinepart.c to use this code.
> >
> > I've been hopefully cc'ing various MTD people but am not being
> > overwhelmed with waves of enthusiasm ;)
> 
> "I've been" implies that you have done so prior to this email. And
> "people" implies more than one person. I see that you CC'd David
> Woodhouse over a week ago, but he's fairly silent these days on MTD
> things. It's Artem or me who handle most of the day-to-day of MTD. And
> this is the first time I've seen this! (BTW, please include
> linux-...@lists.infradead.org for anything involving MTD.)
> 
> This seems reasonable, and I'd be willing to work with this proposal.
> 
> Caizhiyong, can you submit a clear single patch (or series of
> patches), CC'd to linux-mtd at least? Then we can see about supporting
> it in MTD. It doesn't look too difficult, but I need to check that it
> faithfully mimics the capability we currently rely on. There have been
> previous discussions on changing it, but this was rejected in favor of
> allowing more flexibility. Here's part of one such conversation:
> 
> http://lists.infradead.org/pipermail/linux-mtd/2012-August/043599.html
> http://lists.infradead.org/pipermail/linux-mtd/2012-September/043825.html
> http://lists.infradead.org/pipermail/linux-mtd/2012-December/045322.html
> 
> So I would recommend:
> (1) consider carefully the implications of your command-line format
> now, rather than later
> (2) if you want MTD to use it, it needs to support the features we use now

It is fully functional reference MTD, :-).

> 
> Some particular cases to consider: overlapping partitions (how do
> block devices handle overlapping partitions?), out-of-order
> specification, zero sized partitions, mixed syntax (some specified
> with an offset, some not), multiple '-' partitions.

I think the 'offset' just is used to hide some MTD space.
There are two way:
1) redefine the 'offset' as a gap between forward partition and next partition.
2) add code forbid command line partitions overlapping and out-of-order.

I recommend 1), it seems to solve those problem(overlapping and out-of-order), 
but it will affect habit.

> 
> Anyway, if you resend, we can review.
> 
> Thanks,
> Brian
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: [PATCH] block: add command line partition parser

2013-08-14 Thread Andrew Morton
On Wed, 14 Aug 2013 17:11:51 -0700 Brian Norris  
wrote:

> On Wed, Aug 14, 2013 at 3:57 PM, Andrew Morton
>  wrote:
> > On Tue, 13 Aug 2013 06:02:17 + Caizhiyong  wrote:
> >
> >> move the command line parser to a separate module, and change it into
> >> library-style code.
> >>
> >> reference: https://lkml.org/lkml/2013/8/6/550
> 
> The most recent patch is an addendum to this linked patch then?

The unifed latest version is appended.

> > Well OK.  But to prove the library's usefulness and to generally clean
> > up the kernel, someone needs to sign up to the task of converting
> > drivers/mtd/cmdlinepart.c to use this code.
> >
> > I've been hopefully cc'ing various MTD people but am not being
> > overwhelmed with waves of enthusiasm ;)
> 
> "I've been" implies that you have done so prior to this email. And
> "people" implies more than one person. I see that you CC'd David
> Woodhouse over a week ago, but he's fairly silent these days on MTD
> things. It's Artem or me who handle most of the day-to-day of MTD. And
> this is the first time I've seen this! (BTW, please include
> linux-...@lists.infradead.org for anything involving MTD.)
> 
> This seems reasonable, and I'd be willing to work with this proposal.

Thanks.

> Caizhiyong, can you submit a clear single patch (or series of
> patches), CC'd to linux-mtd at least? Then we can see about supporting
> it in MTD. It doesn't look too difficult, but I need to check that it
> faithfully mimics the capability we currently rely on. There have been
> previous discussions on changing it, but this was rejected in favor of
> allowing more flexibility. Here's part of one such conversation:
> 
> http://lists.infradead.org/pipermail/linux-mtd/2012-August/043599.html
> http://lists.infradead.org/pipermail/linux-mtd/2012-September/043825.html
> http://lists.infradead.org/pipermail/linux-mtd/2012-December/045322.html
> 
> So I would recommend:
> (1) consider carefully the implications of your command-line format
> now, rather than later
> (2) if you want MTD to use it, it needs to support the features we use now
> 
> Some particular cases to consider: overlapping partitions (how do
> block devices handle overlapping partitions?), out-of-order
> specification, zero sized partitions, mixed syntax (some specified
> with an offset, some not), multiple '-' partitions.

This patch is still at the review-and-under-test stage so now is a fine
time to make changes.

> Anyway, if you resend, we can review.

From: Cai Zhiyong 
Subject: block: support embedded device command line partition

Read block device partition table from command line.  The partition used
for fixed block device (eMMC) embedded device.  It is no MBR, save storage
space.  Bootloader can be easily accessed by absolute address of data on
the block device.  Users can easily change the partition.

This code reference MTD partition, source "drivers/mtd/cmdlinepart.c"
About the partition verbose reference
"Documentation/block/cmdline-partition.txt"

[a...@linux-foundation.org: fix printk text]
Signed-off-by: Cai Zhiyong 
Cc: Karel Zak 
Cc: "Wanglin (Albert)" 
Cc: Marius Groeger 
Cc: David Woodhouse 
Cc: Jens Axboe 
Cc: Brian Norris 
Cc: Artem Bityutskiy 
Signed-off-by: Andrew Morton 
---

 Documentation/block/cmdline-partition.txt |   40 +++
 block/Kconfig |6 
 block/Makefile|1 
 block/cmdline-parser.c|  249 
 block/partitions/Kconfig  |7 
 block/partitions/Makefile |1 
 block/partitions/check.c  |4 
 block/partitions/cmdline.c|   99 +++
 block/partitions/cmdline.h|2 
 include/linux/cmdline-parser.h|   43 +++
 10 files changed, 452 insertions(+)

diff -puN /dev/null Documentation/block/cmdline-partition.txt
--- /dev/null
+++ a/Documentation/block/cmdline-partition.txt
@@ -0,0 +1,40 @@
+Embedded device command line partition
+=
+
+Read block device partition table from command line.
+The partition used for fixed block device (eMMC) embedded device.
+It is no MBR, save storage space. Bootloader can be easily accessed
+by absolute address of data on the block device.
+Users can easily change the partition.
+
+The format for the command line is just like mtdparts:
+
+blkdevparts=[;]
+   := :[,]
+ := [@](part-name)
+
+
+block device disk name, embedded device used fixed block device,
+it's disk name also fixed. such as: mmcblk0, mmcblk1, mmcblk0boot0.
+
+
+partition size, in bytes, such as: 512, 1m, 1G.
+
+
+partition start address, in bytes.
+
+(part-name)
+partition name, kernel send uevent with "PARTNAME". application can create
+a link to block device partition with the name "PARTNAME".
+user space application can access partition by partition name.
+
+Example:
+eMMC disk name is "mmcblk0" and "mm

Re: [PATCH] block: add command line partition parser

2013-08-14 Thread Brian Norris
On Wed, Aug 14, 2013 at 3:57 PM, Andrew Morton
 wrote:
> On Tue, 13 Aug 2013 06:02:17 + Caizhiyong  wrote:
>
>> move the command line parser to a separate module, and change it into
>> library-style code.
>>
>> reference: https://lkml.org/lkml/2013/8/6/550

The most recent patch is an addendum to this linked patch then?

> Well OK.  But to prove the library's usefulness and to generally clean
> up the kernel, someone needs to sign up to the task of converting
> drivers/mtd/cmdlinepart.c to use this code.
>
> I've been hopefully cc'ing various MTD people but am not being
> overwhelmed with waves of enthusiasm ;)

"I've been" implies that you have done so prior to this email. And
"people" implies more than one person. I see that you CC'd David
Woodhouse over a week ago, but he's fairly silent these days on MTD
things. It's Artem or me who handle most of the day-to-day of MTD. And
this is the first time I've seen this! (BTW, please include
linux-...@lists.infradead.org for anything involving MTD.)

This seems reasonable, and I'd be willing to work with this proposal.

Caizhiyong, can you submit a clear single patch (or series of
patches), CC'd to linux-mtd at least? Then we can see about supporting
it in MTD. It doesn't look too difficult, but I need to check that it
faithfully mimics the capability we currently rely on. There have been
previous discussions on changing it, but this was rejected in favor of
allowing more flexibility. Here's part of one such conversation:

http://lists.infradead.org/pipermail/linux-mtd/2012-August/043599.html
http://lists.infradead.org/pipermail/linux-mtd/2012-September/043825.html
http://lists.infradead.org/pipermail/linux-mtd/2012-December/045322.html

So I would recommend:
(1) consider carefully the implications of your command-line format
now, rather than later
(2) if you want MTD to use it, it needs to support the features we use now

Some particular cases to consider: overlapping partitions (how do
block devices handle overlapping partitions?), out-of-order
specification, zero sized partitions, mixed syntax (some specified
with an offset, some not), multiple '-' partitions.

Anyway, if you resend, we can review.

Thanks,
Brian
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Re: [PATCH] block: add command line partition parser

2013-08-14 Thread Andrew Morton
On Tue, 13 Aug 2013 06:02:17 + Caizhiyong  wrote:

> move the command line parser to a separate module, and change it into
> library-style code.
> 
> reference: https://lkml.org/lkml/2013/8/6/550

Well OK.  But to prove the library's usefulness and to generally clean
up the kernel, someone needs to sign up to the task of converting
drivers/mtd/cmdlinepart.c to use this code.

I've been hopefully cc'ing various MTD people but am not being
overwhelmed with waves of enthusiasm ;)


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