Re: [PATCH] register_blkdev

Re: [PATCH] register_blkdev

[Andries.Brouwer]

> IMHO that's a bad change, (un)register_blkdev should just go away
> completly.

Yes, it would be best if the kernel became perfect at once.
But the patch is rather large. Better go in small steps.

Did you read the patch?

+/* Can be merged with blk_probe or deleted altogether. Later. */
+static struct blk_major_name {

Andries


[You often do general cleanup. My purpose is not to do
general cleanup, although this is a cleanup. My purpose
is to give us a 32-bit dev_t. After this patch the last
occurrence of MAX_BLKDEV is in raw.c. If Linus takes it,
the next patch will eliminate MAX_BLKDEV.]

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Fri, Mar 07, 2003 at 08:32:01PM +0100, Andries.Brouwer@cwi.nl wrote:
> > IMHO that's a bad change, (un)register_blkdev should just go away
> > completly.
> 
> Yes, it would be best if the kernel became perfect at once.
> But the patch is rather large. Better go in small steps.
> 
> Did you read the patch?

Yes, I did.  What I object to is the prototype changes you did which
make absolutely no sense to get into 2.5 now when the functions will
disappear before 2.6.  Feel free to change the actual implementation,
I couldn't care less on you wasting your time on that :)

Re: [PATCH] register_blkdev

[Andrew Morton]

Christoph Hellwig <hch@infradead.org> wrote:
>
> On Fri, Mar 07, 2003 at 08:32:01PM +0100, Andries.Brouwer@cwi.nl wrote:
> > > IMHO that's a bad change, (un)register_blkdev should just go away
> > > completly.
> > 
> > Yes, it would be best if the kernel became perfect at once.
> > But the patch is rather large. Better go in small steps.
> > 
> > Did you read the patch?
> 
> Yes, I did.  What I object to is the prototype changes you did which
> make absolutely no sense to get into 2.5 now when the functions will
> disappear before 2.6.  Feel free to change the actual implementation,
> I couldn't care less on you wasting your time on that :)

32-bit dev_t is an important (and very late!) thing to get into the 2.5
stream.  Can we put this ahead of cleanup stuff?

Re: [PATCH] register_blkdev

[Greg KH]

On Fri, Mar 07, 2003 at 12:30:29PM -0800, Andrew Morton wrote:
> 
> 32-bit dev_t is an important (and very late!) thing to get into the 2.5
> stream.  Can we put this ahead of cleanup stuff?

Can we get people to agree that this will even go into 2.5, due to the
lateness of it?  I didn't think it was going to happen.

But if it is, a lot of character drivers need to be audited...

thanks,

greg k-h

Re: [PATCH] register_blkdev

[Andrew Morton]

Greg KH <greg@kroah.com> wrote:
>
> On Fri, Mar 07, 2003 at 12:30:29PM -0800, Andrew Morton wrote:
> > 
> > 32-bit dev_t is an important (and very late!) thing to get into the 2.5
> > stream.  Can we put this ahead of cleanup stuff?
> 
> Can we get people to agree that this will even go into 2.5, due to the
> lateness of it?  I didn't think it was going to happen.

I've never seen the patches so I cannot say.  But I'd at least like to get
the whole thing under test so we can make that evaulation.

> But if it is, a lot of character drivers need to be audited...

What has to be done there?

Re: [PATCH] register_blkdev

[Greg KH]

On Fri, Mar 07, 2003 at 02:33:19PM -0800, Andrew Morton wrote:
> Greg KH <greg@kroah.com> wrote:
> >
> > On Fri, Mar 07, 2003 at 12:30:29PM -0800, Andrew Morton wrote:
> > > 
> > > 32-bit dev_t is an important (and very late!) thing to get into the 2.5
> > > stream.  Can we put this ahead of cleanup stuff?
> > 
> > Can we get people to agree that this will even go into 2.5, due to the
> > lateness of it?  I didn't think it was going to happen.
> 
> I've never seen the patches so I cannot say.  But I'd at least like to get
> the whole thing under test so we can make that evaulation.

I would too.  Andries's patches look like the right thing to do, so far
as I've seen.  But there are larger, social issues, that probably need
to be answered first (like convincing Linus and others that this is
really needed).

> > But if it is, a lot of character drivers need to be audited...
> 
> What has to be done there?

I haven't seen a patch yet, to really know what will be necessary.  But
for one, a lot of drivers have static arrays where they just "know" that
there can't be more than 256 minors under their control.

As a small example, look at all of the static arrays of struct
tty_struct * for all of the tty drivers :(

thanks,

greg k-h

Re: [PATCH] register_blkdev

[Alan Cox]

On Fri, 2003-03-07 at 23:45, Greg KH wrote:
> I would too.  Andries's patches look like the right thing to do, so far
> as I've seen.  But there are larger, social issues, that probably need
> to be answered first (like convincing Linus and others that this is
> really needed).
> 
> > > But if it is, a lot of character drivers need to be audited...
> > 
> > What has to be done there?
> 
> I haven't seen a patch yet, to really know what will be necessary.  But
> for one, a lot of drivers have static arrays where they just "know" that
> there can't be more than 256 minors under their control.

So we need a maxminors flag in the register for 2.6 I guess ?

Re: [PATCH] register_blkdev

[Greg KH]

On Sat, Mar 08, 2003 at 01:14:23AM +0000, Alan Cox wrote:
> On Fri, 2003-03-07 at 23:45, Greg KH wrote:
> > I would too.  Andries's patches look like the right thing to do, so far
> > as I've seen.  But there are larger, social issues, that probably need
> > to be answered first (like convincing Linus and others that this is
> > really needed).
> > 
> > > > But if it is, a lot of character drivers need to be audited...
> > > 
> > > What has to be done there?
> > 
> > I haven't seen a patch yet, to really know what will be necessary.  But
> > for one, a lot of drivers have static arrays where they just "know" that
> > there can't be more than 256 minors under their control.
> 
> So we need a maxminors flag in the register for 2.6 I guess ?

Do you mean to only increase the number of majors, and not minors then?

greg k-h

Re: [PATCH] register_blkdev

[Andrew Morton]

Greg KH <greg@kroah.com> wrote:
>
> On Sat, Mar 08, 2003 at 01:14:23AM +0000, Alan Cox wrote:
> > On Fri, 2003-03-07 at 23:45, Greg KH wrote:
> > > I would too.  Andries's patches look like the right thing to do, so far
> > > as I've seen.  But there are larger, social issues, that probably need
> > > to be answered first (like convincing Linus and others that this is
> > > really needed).
> > > 
> > > > > But if it is, a lot of character drivers need to be audited...
> > > > 
> > > > What has to be done there?
> > > 
> > > I haven't seen a patch yet, to really know what will be necessary.  But
> > > for one, a lot of drivers have static arrays where they just "know" that
> > > there can't be more than 256 minors under their control.
> > 
> > So we need a maxminors flag in the register for 2.6 I guess ?
> 
> Do you mean to only increase the number of majors, and not minors then?
> 

Some time back Linus expressed a preference for a 2^20 major / 2^12 minor split.

Re: [PATCH] register_blkdev

[Greg KH]

On Fri, Mar 07, 2003 at 05:05:20PM -0800, Andrew Morton wrote:
> 
> Some time back Linus expressed a preference for a 2^20 major / 2^12 minor split.

I remember that too. That's still increasing the number of minors, hence
my original reservation about auditing drivers.

thanks,

greg k-h

Re: [PATCH] register_blkdev

[Linus Torvalds]

On Fri, 7 Mar 2003, Andrew Morton wrote:
> 
> Some time back Linus expressed a preference for a 2^20 major / 2^12 minor split.

Other way around. 12 bits for major, 20 bits for minor.

Minor numbers tend to get used up more quickly, as shown by the current 
state of affairs, and also as trivially shown by things like pty-like 
virtual devices that pretty much scale arbitrarily with memory and users.

I don't much care personally. I think the devil is in the details, and 
making sure we don't have legacy code that just knows about the fact that 
it can index a 256-entry array with the minor number.

Also, I have to say that over time I've become convinced that it's just a
painful mistake to mix up minor and major numbers, so it might well be
sensible for people who actually care about them to always keep them
separate. That would actually imply that 32+32 is the right thing to do
internally after all, and any other limits (whether they be 8+8, 12+20 or
16+16) would be limited by things like over-the-wire or on-the-disk
representations.

			Linus

Re: [PATCH] register_blkdev

[Alan Cox]

On Sat, 2003-03-08 at 01:13, Linus Torvalds wrote:
> On Fri, 7 Mar 2003, Andrew Morton wrote:
> > 
> > Some time back Linus expressed a preference for a 2^20 major / 2^12 minor split.
> 
> Other way around. 12 bits for major, 20 bits for minor.
> 
> Minor numbers tend to get used up more quickly, as shown by the current 
> state of affairs, and also as trivially shown by things like pty-like 
> virtual devices that pretty much scale arbitrarily with memory and users.

20:12 is easier for the current behaviour. 12:20 with the ability to hand out
sections of space has great potential for lumping things like "disks", 
"serial ports" and so on together in more logical ways. 12:20 also makes the
compatibility logic easier since all of the legacy space falls in "major 0"
which becomes the remangler.

Is there any reason for not using CIDR like schemes as Al Viro proposed a long
time back (I think it was Al anyway). That also sorts out the auditing problem

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Sat, Mar 08, 2003 at 03:09:37PM +0000, Alan Cox wrote:
> Is there any reason for not using CIDR like schemes as Al Viro proposed a long
> time back (I think it was Al anyway). That also sorts out the auditing problem

Al did implement it for block devices, it's already in 2.5.

Re: [PATCH] register_blkdev

[Chris Wedgwood]

On Sat, Mar 08, 2003 at 03:09:37PM +0000, Alan Cox wrote:

> Is there any reason for not using CIDR like schemes as Al Viro
> proposed a long time back (I think it was Al anyway). That also
> sorts out the auditing problem

Some of of CIDR approach seems extremely elegant and reasonable
scalable to me...  look how far the (relatively) poorly managed
Internet-address space has gotten with similar ideas...


  --cw

Re: [PATCH] register_blkdev

[Oliver Xymoron]

On Sat, Mar 08, 2003 at 03:09:37PM +0000, Alan Cox wrote:
> On Sat, 2003-03-08 at 01:13, Linus Torvalds wrote:
> > On Fri, 7 Mar 2003, Andrew Morton wrote:
> > > 
> > > Some time back Linus expressed a preference for a 2^20 major / 2^12 minor split.
> > 
> > Other way around. 12 bits for major, 20 bits for minor.
> > 
> > Minor numbers tend to get used up more quickly, as shown by the current 
> > state of affairs, and also as trivially shown by things like pty-like 
> > virtual devices that pretty much scale arbitrarily with memory and users.
> 
> 20:12 is easier for the current behaviour. 12:20 with the ability to hand out
> sections of space has great potential for lumping things like "disks", 
> "serial ports" and so on together in more logical ways. 12:20 also makes the
> compatibility logic easier since all of the legacy space falls in "major 0"
> which becomes the remangler.
> 
> Is there any reason for not using CIDR like schemes as Al Viro proposed a long
> time back (I think it was Al anyway). That also sorts out the auditing problem

I think it was actually me, arguing with Viro. I was building a device
number registration layer on top of the new resource tree structure at
the time (now 3 years ago!). And in retrospect, I think 32:32
internally with an 8:8 legacy mangler is probably the sanest way to
go.

-- 
 "Love the dolphins," she advised him. "Write by W.A.S.T.E.." 

Re: [PATCH] register_blkdev

[Alan Cox]

On Sat, 2003-03-08 at 00:50, Greg KH wrote:
> > So we need a maxminors flag in the register for 2.6 I guess ?
> 
> Do you mean to only increase the number of majors, and not minors then?

How about an interface that looks like

	register_chr_device(blah. blah, MY_MAX_MINOR);

and we can delete all the if < 0 || >= MAX return logic from the drivers
as we go. Right now each driver checks and several in the past had off 
by one errors.

Re: [PATCH] register_blkdev

[Greg KH]

On Sat, Mar 08, 2003 at 03:11:42PM +0000, Alan Cox wrote:
> On Sat, 2003-03-08 at 00:50, Greg KH wrote:
> > > So we need a maxminors flag in the register for 2.6 I guess ?
> > 
> > Do you mean to only increase the number of majors, and not minors then?
> 
> How about an interface that looks like
> 
> 	register_chr_device(blah. blah, MY_MAX_MINOR);
> 
> and we can delete all the if < 0 || >= MAX return logic from the drivers
> as we go. Right now each driver checks and several in the past had off 
> by one errors.

That's a good start, but why not change that to a simple,
HOW_MANY_MINORS_I_WANT, which will work the same way now, but allow us
to change to a pure dynamic major/minor allocation scheme in the future
by only modifying the register_chr_device() code.  Same thing for
register_blkdev().

Although if we increase the width of dev_t then a need for dynamic
major/minors is pretty much gone...

thanks,

greg k-h

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Sat, Mar 08, 2003 at 11:37:22AM -0800, Greg KH wrote:
> That's a good start, but why not change that to a simple,
> HOW_MANY_MINORS_I_WANT, which will work the same way now, but allow us
> to change to a pure dynamic major/minor allocation scheme in the future
> by only modifying the register_chr_device() code.  Same thing for
> register_blkdev().

register_blkdev() _IS_ totally meaningless in 2.5.  I said this about three
times in this thread already, when will people actually take a look at
the code they look at?

Re: [PATCH] register_blkdev

[Greg KH]

On Sat, Mar 08, 2003 at 07:50:28PM +0000, Christoph Hellwig wrote:
> On Sat, Mar 08, 2003 at 11:37:22AM -0800, Greg KH wrote:
> > That's a good start, but why not change that to a simple,
> > HOW_MANY_MINORS_I_WANT, which will work the same way now, but allow us
> > to change to a pure dynamic major/minor allocation scheme in the future
> > by only modifying the register_chr_device() code.  Same thing for
> > register_blkdev().
> 
> register_blkdev() _IS_ totally meaningless in 2.5.  I said this about three
> times in this thread already, when will people actually take a look at
> the code they look at?

I've looked at it, and right now it keeps drivers from registering the
same major number, and provides a pretty string for the requested major,
when the kernel wants to print it out.

Yes, most of the old code and logic is now gone, but can you just remove
the call altogether now?  If so, great :)

greg k-h

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Sat, Mar 08, 2003 at 12:00:16PM -0800, Greg KH wrote:
> I've looked at it, and right now it keeps drivers from registering the
> same major number,

No.  Because it doesn't actually register the number anymore.  It's perfectly
valid to have a 2.5 block driver that never calls register_blkdev().

> Yes, most of the old code and logic is now gone, but can you just remove
> the call altogether now?  If so, great :)

We can get rid of it if people have no problem with __bdevname printing
less pretty strings and /proc/devices going away for block devices (which
is buggy now anyway).  I'm all in favour of it.

Re: [PATCH] register_blkdev

[Joel Becker]

On Fri, Mar 07, 2003 at 02:12:17PM -0800, Greg KH wrote:
> On Fri, Mar 07, 2003 at 12:30:29PM -0800, Andrew Morton wrote:
> > 32-bit dev_t is an important (and very late!) thing to get into the 2.5
> > stream.  Can we put this ahead of cleanup stuff?
> 
> Can we get people to agree that this will even go into 2.5, due to the
> lateness of it?  I didn't think it was going to happen.

	This is essential.  There are installations using >1000 disks
today (on other OSes, generally).  It can't wait another 2.5 years.

Joel

-- 

Life's Little Instruction Book #237

	"Seek out the good in people."

Joel Becker
Senior Member of Technical Staff
Oracle Corporation
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Fri, Mar 07, 2003 at 02:55:18PM -0800, Joel Becker wrote:
> On Fri, Mar 07, 2003 at 02:12:17PM -0800, Greg KH wrote:
> > On Fri, Mar 07, 2003 at 12:30:29PM -0800, Andrew Morton wrote:
> > > 32-bit dev_t is an important (and very late!) thing to get into the 2.5
> > > stream.  Can we put this ahead of cleanup stuff?
> > 
> > Can we get people to agree that this will even go into 2.5, due to the
> > lateness of it?  I didn't think it was going to happen.
> 
> 	This is essential.  There are installations using >1000 disks

and?  we still have tons of free block majors..

Re: [PATCH] register_blkdev

[Randy.Dunlap]

On Fri, 7 Mar 2003 22:57:10 +0000 Christoph Hellwig <hch@infradead.org> wrote:

| On Fri, Mar 07, 2003 at 02:55:18PM -0800, Joel Becker wrote:
| > On Fri, Mar 07, 2003 at 02:12:17PM -0800, Greg KH wrote:
| > > On Fri, Mar 07, 2003 at 12:30:29PM -0800, Andrew Morton wrote:
| > > > 32-bit dev_t is an important (and very late!) thing to get into the 2.5
| > > > stream.  Can we put this ahead of cleanup stuff?
| > > 
| > > Can we get people to agree that this will even go into 2.5, due to the
| > > lateness of it?  I didn't think it was going to happen.

Yes from this side of the street.

| > 	This is essential.  There are installations using >1000 disks
| 
| and?  we still have tons of free block majors..

What has to be done to uses those?  Just grab unassigned majors from devices.txt
and run with them, or something else?  (as well as mknod's of course)
Or use devfs?

--
~Randy

Re: [PATCH] register_blkdev

[John Cherry]

On Fri, 2003-03-07 at 15:17, Randy.Dunlap wrote:
> On Fri, 7 Mar 2003 22:57:10 +0000 Christoph Hellwig <hch@infradead.org> wrote:
> 
> | On Fri, Mar 07, 2003 at 02:55:18PM -0800, Joel Becker wrote:
> | > On Fri, Mar 07, 2003 at 02:12:17PM -0800, Greg KH wrote:
> | > > On Fri, Mar 07, 2003 at 12:30:29PM -0800, Andrew Morton wrote:
> | > > > 32-bit dev_t is an important (and very late!) thing to get into the 2.5
> | > > > stream.  Can we put this ahead of cleanup stuff?
> | > > 
> | > > Can we get people to agree that this will even go into 2.5, due to the
> | > > lateness of it?  I didn't think it was going to happen.
> 
> Yes from this side of the street.
> 
> | > 	This is essential.  There are installations using >1000 disks
> | 
> | and?  we still have tons of free block majors..
> 
> What has to be done to uses those?  Just grab unassigned majors from devices.txt
> and run with them, or something else?  (as well as mknod's of course)
> Or use devfs?

Sure. You could grab unassigned majors...if that is what you want to
do.  There are a number of ways to "get around" the lack of minor
numbers.  None of them follow conventional thinking with regards to
major/minor usage.

John

> 
> --
> ~Randy
> -
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Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Fri, Mar 07, 2003 at 03:38:18PM -0800, John Cherry wrote:
> Sure. You could grab unassigned majors...if that is what you want to
> do.  There are a number of ways to "get around" the lack of minor
> numbers.  None of them follow conventional thinking with regards to
> major/minor usage.

If you actually looked at the block layer code instead of just talking
along you'd see that the major/minor split has absolutely zero meaning
for the actual driver interface in 2.5.  The only major numbers have
any meanting to is pretty printing (/proc/devices and __bdevname).

Re: [PATCH] register_blkdev

[Andrew Morton]

Christoph Hellwig <hch@infradead.org> wrote:
>
> If you actually looked at the block layer code instead of just talking
> along you'd see that the major/minor split has absolutely zero meaning
> for the actual driver interface in 2.5.  The only major numbers have
> any meanting to is pretty printing (/proc/devices and __bdevname).
> 

Christoph, it would help this discussion very much if you could tell everyone
how we should set about solving the many-disks problem.  In detail.

Thanks.

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Fri, Mar 07, 2003 at 03:46:24PM -0800, Andrew Morton wrote:
> Christoph, it would help this discussion very much if you could tell everyone
> how we should set about solving the many-disks problem.  In detail.

Just use blk_register_region() to claim the region you want, you
don't have to care for any major/minor binary.  There is not much of
the dev_t space used for block devices at all so there's no problem.

Actually coordinating those allocations with LANANA might help to not
step other people on their feet, but your return value will tell that
anyway.

Re: [PATCH] register_blkdev

[Joel Becker]

On Fri, Mar 07, 2003 at 11:54:54PM +0000, Christoph Hellwig wrote:
> On Fri, Mar 07, 2003 at 03:46:24PM -0800, Andrew Morton wrote:
> > Christoph, it would help this discussion very much if you could tell everyone
> > how we should set about solving the many-disks problem.  In detail.
> 
> Just use blk_register_region() to claim the region you want, you
> don't have to care for any major/minor binary.  There is not much of
> the dev_t space used for block devices at all so there's no problem.

	There are a couple issues with this.  I wasn't aware there were
enough free majors to cover systems with 4000 disks.  Those systems
exist today.  They're only going to grow.
	If you are dynamically building majors, how do you populate
/dev?

Joel

-- 

Life's Little Instruction Book #24

	"Drink champagne for no reason at all."

Joel Becker
Senior Member of Technical Staff
Oracle Corporation
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127

Re: [PATCH] register_blkdev

[Greg KH]

On Fri, Mar 07, 2003 at 05:49:11PM -0800, Joel Becker wrote:
> 
> 	There are a couple issues with this.  I wasn't aware there were
> enough free majors to cover systems with 4000 disks.  Those systems
> exist today.  They're only going to grow.
> 	If you are dynamically building majors, how do you populate
> /dev?

<shameless plug>

http://www.linuxsymposium.org/2003/view_abstract.php?talk=94

greg k-h

Re: [PATCH] register_blkdev

[Joel Becker]

On Fri, Mar 07, 2003 at 05:58:06PM -0800, Greg KH wrote:
> <shameless plug>
> 
> http://www.linuxsymposium.org/2003/view_abstract.php?talk=94

	I personally think that /dev population should exist in
userspace as well.  I *hope* you mean to populate a regular filesystem
with device nodes that your system manages.
	That said, however /dev is populated, we need the dev_t space to
represent the devices :-)

Joel

-- 

"Anything that is too stupid to be spoken is sung."  
        - Voltaire

Joel Becker
Senior Member of Technical Staff
Oracle Corporation
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127

Re: [PATCH] register_blkdev

[Linus Torvalds]

On Fri, 7 Mar 2003, Joel Becker wrote:
> 
> 	That said, however /dev is populated, we need the dev_t space to
> represent the devices :-)

And realize that these things are often limited by on-disk / wire
representations. Some of which are easier to fix than others (ie, think 
about NFS servers running old versions of Linux).

		Linus

Re: [PATCH] register_blkdev

[Joel Becker]

On Fri, Mar 07, 2003 at 06:18:19PM -0800, Linus Torvalds wrote:
> And realize that these things are often limited by on-disk / wire
> representations. Some of which are easier to fix than others (ie, think 
> about NFS servers running old versions of Linux).

	Yeah, I was chatting with Peter about that last night (he was
advocating 64 bits for dev_t).  For some things (NFSv2) we could merely
truncate the space.  It only really matters if /dev is on NFS, and we
can perhaps say "You need NFSv3 or better if you want the larger dev
space".  That's just one possible way to approach it.  A system big
enough to have 5000 disks attached likely isn't getting /dev from an
NFSv2 server.
	I'm so-so on the 64bit vs 32bit dev_t argument, but I'd bet we
only want to change it once for the internal representation.  How we
handle external representations (on disk, over the wire) is a different
matter.

Joel

-- 

"The one important thing i have learned over the years is the difference
 between taking one's work seriously and taking one's self seriously.  The
 first is imperative and the second is disastrous."
	-Margot Fonteyn

Joel Becker
Senior Member of Technical Staff
Oracle Corporation
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127

Re: [PATCH] register_blkdev

[Greg KH]

On Fri, Mar 07, 2003 at 06:15:05PM -0800, Joel Becker wrote:
> 
> 	I personally think that /dev population should exist in
> userspace as well.  I *hope* you mean to populate a regular filesystem
> with device nodes that your system manages.

Yes, a ramfs partition is the original target.

thanks,

greg k-h

Re: [PATCH] register_blkdev

[Joel Becker]

On Sat, Mar 08, 2003 at 11:31:37AM -0800, Greg KH wrote:
> Yes, a ramfs partition is the original target.

	Using dd(1) to copy the partition to permanent storage between
boots?  You do have to solve the permanence problem.  I was thinking
more along the lines of /dev staying in /, and the userspace system
updating it at boot.

Joel


-- 

"I don't know anything about music. In my line you don't have
 to."
        - Elvis Presley

Joel Becker
Senior Member of Technical Staff
Oracle Corporation
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127

Re: [PATCH] register_blkdev

[Greg KH]

On Sat, Mar 08, 2003 at 01:39:33PM -0800, Joel Becker wrote:
> On Sat, Mar 08, 2003 at 11:31:37AM -0800, Greg KH wrote:
> > Yes, a ramfs partition is the original target.
> 
> 	Using dd(1) to copy the partition to permanent storage between
> boots?  You do have to solve the permanence problem.  I was thinking
> more along the lines of /dev staying in /, and the userspace system
> updating it at boot.

The permanent storage issue will be handled somehow, the details are
still being worked out :)

thanks,

greg k-h

Re: [PATCH] register_blkdev

[Alan Cox]

On Fri, 2003-03-07 at 22:57, Christoph Hellwig wrote:
> > 	This is essential.  There are installations using >1000 disks
> 
> and?  we still have tons of free block majors..

You can throw 65536 volumes onto a single S/390 box. Going to 32bit
dev_t sorts out a lot of the problems people have with major numbering
and allocation of devices sensibly, it means I can finally get the
space to do stuff like supporting session mounting on cd too

Re: [PATCH] register_blkdev

[Horst von Brand]

Joel Becker <Joel.Becker@oracle.com> said:
> On Fri, Mar 07, 2003 at 02:12:17PM -0800, Greg KH wrote:
> > On Fri, Mar 07, 2003 at 12:30:29PM -0800, Andrew Morton wrote:
> > > 32-bit dev_t is an important (and very late!) thing to get into the 2.5
> > > stream.  Can we put this ahead of cleanup stuff?
> > 
> > Can we get people to agree that this will even go into 2.5, due to the
> > lateness of it?  I didn't think it was going to happen.
> 
> 	This is essential.  There are installations using >1000 disks
> today (on other OSes, generally).  It can't wait another 2.5 years.

This kind of changes in the middle of feature freeze are exactly what gets
you to 2.5 years.
-- 
Dr. Horst H. von Brand                   User #22616 counter.li.org
Departamento de Informatica                     Fono: +56 32 654431
Universidad Tecnica Federico Santa Maria              +56 32 654239
Casilla 110-V, Valparaiso, Chile                Fax:  +56 32 797513

Re: [PATCH] register_blkdev

[Valdis.Kletnieks]

[-- Attachment #1: Type: text/plain, Size: 720 bytes --]

On Sun, 09 Mar 2003 00:32:56 -0400, Horst von Brand said:
> This kind of changes in the middle of feature freeze are exactly what gets
> you to 2.5 years.

On Sat, Mar 08, 2003 at 07:43:31PM +0000, Christoph Hellwig wrote:
> So people should have started working on it sooner.  If people really think
> they need a 32bit dev_t for their $BIGNUM of disks (and I still don't buy
> that argument) we should just introduce it and use it only for block devices
> (which already are fixed up for this) and stay with the old 8+8 split for
> character devices.  Note that Linux is about doing stuff right, not fast.

*shrug* In the end, it's Linus's call on how to balance the release date
against the features that make it in.

[-- Attachment #2: Type: application/pgp-signature, Size: 226 bytes --]

Re: [PATCH] register_blkdev

[Andries.Brouwer]

> We need to get rid of the artifical major/minor split completly

I do not disagree with you, but your point of view seems
to be that either we make everything perfect or we do nothing.
I prefer slow progress.

Concerning this split - traces of it occur in a very large
number of places. Let me just mention the raw device that
I did this afternoon. How does one connect a raw device
with a block device? Using a struct raw_config_request
from user space. And look

struct raw_config_request
{
        int     raw_minor;
        __u64   block_major;
        __u64   block_minor;
};

One of the many places that has a built-in major/minor split.
Basically this split is unimportant. A dev_t is just a cookie.
But as soon as you start looking at details this split is
all over the place.

Andries

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Sat, Mar 08, 2003 at 09:59:14PM +0100, Andries.Brouwer@cwi.nl wrote:
> > We need to get rid of the artifical major/minor split completly
> 
> I do not disagree with you, but your point of view seems
> to be that either we make everything perfect or we do nothing.
> I prefer slow progress.

I completly agree with you on the slow steps.  What we seem to
disagree about is the order of steps..

> Concerning this split - traces of it occur in a very large
> number of places.

Yupp.  And getting rid of those one by one is a a good thing
and I'm happy about every single patch you submit to get rid
of one.

> Let me just mention the raw device that
> I did this afternoon. How does one connect a raw device
> with a block device? Using a struct raw_config_request
> from user space. And look
> 
> struct raw_config_request
> {
>         int     raw_minor;
>         __u64   block_major;
>         __u64   block_minor;
> };
> 
> One of the many places that has a built-in major/minor split.
> Basically this split is unimportant. A dev_t is just a cookie.
> But as soon as you start looking at details this split is
> all over the place.

Yes.  And my opinion is that we need to sort these issues out
one for one before moving on to make dev_t bigger, not the other
way around.

Re: [PATCH] register_blkdev

[Andries.Brouwer]

>> That's why the character device code should get a similar massaging

> I agree, I thought this was a 2.7 change, but it's looking like people
> want this change sooner :)

There is no need to do all of that. Going to 32-bit dev_t
is trivial, not a major restructuring.

Three minutes editing of kdev_t.h and posix_types.h and you have it.
Boot the kernel and it runs fine.

However, it can be crashed from userspace, so before we do
the three minutes editing the audit is needed.
Look at the patch for raw.c I posted a few hours ago.
One trivial test.

If we do it as Alan suggested even this one test can be
avoided in most places.

> If people really think they need a 32bit dev_t
> we should just introduce it and use it only for block devices
> and stay with the old 8+8 split for character devices.

Of course discussing the future and how the cake should
be divided once we have it may be of interest - but let
us bake the cake first. The work required is entirely
independent of the size and structure of dev_t.

Andries - curious whether 2.5.65 will show progress


[not that the road isn't long - once the kernel is happy
there are some glibc details - strange enough glibc uses
a gigantic dev_t but simultaneously assumes that major and
minor only have a few bits]

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Sat, Mar 08, 2003 at 09:26:15PM +0100, Andries.Brouwer@cwi.nl wrote:
> There is no need to do all of that. Going to 32-bit dev_t
> is trivial, not a major restructuring.

Doing it _right_ does require major restructuring. 

> However, it can be crashed from userspace, so before we do
> the three minutes editing the audit is needed.
> Look at the patch for raw.c I posted a few hours ago.
> One trivial test.

And probably one of them in at least half of the character drivers.  We need
to get rid of the artifical major/minor split completly instead of just
increasing it, leaving silly assumptions in and increasing the space consumed
by all those arrays by magnitudes.

> > If people really think they need a 32bit dev_t
> > we should just introduce it and use it only for block devices
> > and stay with the old 8+8 split for character devices.
> 
> Of course discussing the future and how the cake should
> be divided once we have it may be of interest

No, the point is that the character devices aren't ready yet for moving
away from the old 8+8 split.

Re: [PATCH] register_blkdev

[Andries.Brouwer]

> register_chrdev() only allocates based on a major

Yes.

[Silly enough. The entire business of registration does not
depend at all on whether one is a character or a block device.
I am really unhappy with the fact that the completely uniform
code that we used to have now has been split into two rather
separate pieces of code.]

But you are quite right that an audit is needed.

[I think I described the amount of work as: two hours to make
the patches, a weekend to do the audit.]

Andries

Re: [PATCH] register_blkdev

[Andries.Brouwer]

> social issues, that probably need to be answered first

Why worry? Why first?

Here are patches that go in the right direction, as
everybody agrees, I think.
So far Linus has taken my recent dev_t related patches
(even though the last two did not appear under my name).

I don't think anybody is willing to commit himself blindly
to unseen patches.

> a lot of drivers have static arrays where they just "know" that
> there can't be more than 256 minors under their control.

That does not matter so much.

There is the matter of correctness and the matter of power.
I worry most about correctness.

So my first job is to make sure that no bad minor is ever used
as array index. Fortunately registration is not by major but
by dev_t interval, so things tend to be correct automatically.

That is the audit-for-correctness part. Then there is the
power part. If a driver wants to handle many minors, it
can register a large range, or several ranges, possibly
dynamically. These changes are done on a driver-by-driver basis,
and need not be done before the type of dev_t is switched.

Andries

Re: [PATCH] register_blkdev

[Greg KH]

On Sat, Mar 08, 2003 at 01:57:00AM +0100, Andries.Brouwer@cwi.nl wrote:
> So my first job is to make sure that no bad minor is ever used
> as array index. Fortunately registration is not by major but
> by dev_t interval, so things tend to be correct automatically.

But register_chrdev() only allocates based on a major.  If a character
driver asks for a major, today it only thinks it has 256 minors, so that
number is usually hard coded in an array.  If a open() happens on a
minor outside that range, the driver will die a horrible death, right?

thanks,

greg k-h

Re: [PATCH] register_blkdev

[Greg KH]

On Sat, Mar 08, 2003 at 07:34:07AM +0000, Christoph Hellwig wrote:
> On Fri, Mar 07, 2003 at 04:53:33PM -0800, Greg KH wrote:
> > driver asks for a major, today it only thinks it has 256 minors, so that
> > number is usually hard coded in an array.  If a open() happens on a
> > minor outside that range, the driver will die a horrible death, right?
> 
> Yes.  That's why the character device code should get a similar massaging
> as the block layer code got in 2.5.  But I don't really see this happen
> in the 2.6 timeframe, especially given that there are a lot more character
> than block drivers.

I agree, I thought this was a 2.7 change, but it's looking like people
want this change sooner :)

greg k-h

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Sat, Mar 08, 2003 at 11:29:08AM -0800, Greg KH wrote:
> I agree, I thought this was a 2.7 change, but it's looking like people
> want this change sooner :)

So people should have started working on it sooner.  If people really think
they need a 32bit dev_t for their $BIGNUM of disks (and I still don't buy
that argument) we should just introduce it and use it only for block devices
(which already are fixed up for this) and stay with the old 8+8 split for
character devices.  Note that Linux is about doing stuff right, not fast.

Re: [PATCH] register_blkdev

[H. Peter Anvin]

Followup to:  <20030308194331.A31291@infradead.org>
By author:    Christoph Hellwig <hch@infradead.org>
In newsgroup: linux.dev.kernel
> 
> So people should have started working on it sooner.  If people really think
> they need a 32bit dev_t for their $BIGNUM of disks (and I still don't buy
> that argument) we should just introduce it and use it only for block devices
> (which already are fixed up for this) and stay with the old 8+8 split for
> character devices.  Note that Linux is about doing stuff right, not fast.
> 

We need it if anything even more for character devices.  Character
devices are under even more allocation pressure, and just look at the
ugly hacks we've already had to play for e.g. tty devices.

	-hpa
-- 
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."
Architectures needed: ia64 m68k mips64 ppc ppc64 s390 s390x sh v850 x86-64

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Sat, Mar 08, 2003 at 01:26:37PM -0800, H. Peter Anvin wrote:
> We need it if anything even more for character devices.  Character
> devices are under even more allocation pressure, and just look at the
> ugly hacks we've already had to play for e.g. tty devices.

Yes.  That's why the work applied to block devices already needs to
be done to character device too and as a side-effect we get an
almost 32bit dev_t clean tree, too.

Re: [PATCH] register_blkdev

[Joel Becker]

On Sat, Mar 08, 2003 at 07:43:31PM +0000, Christoph Hellwig wrote:
> So people should have started working on it sooner.  If people really think
> they need a 32bit dev_t for their $BIGNUM of disks (and I still don't buy
> that argument) we should just introduce it and use it only for block devices
> (which already are fixed up for this) and stay with the old 8+8 split for
> character devices.  Note that Linux is about doing stuff right, not fast.

	Wait, so ugly hacks that steal every remaining major is doing it
'right'?  I've done the math with the current available majors.  I don't
see 4000 disks there, and that is just life as it exists today, not 2-3
years from now when 2.8 finally appears.  Like Andrew asked, please
describe exactly how you'd support it.

Joel


-- 

"Behind every successful man there's a lot of unsuccessful years."
        - Bob Brown

Joel Becker
Senior Member of Technical Staff
Oracle Corporation
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Sat, Mar 08, 2003 at 01:41:30PM -0800, Joel Becker wrote:
> On Sat, Mar 08, 2003 at 07:43:31PM +0000, Christoph Hellwig wrote:
> > So people should have started working on it sooner.  If people really think
> > they need a 32bit dev_t for their $BIGNUM of disks (and I still don't buy
> > that argument) we should just introduce it and use it only for block devices
> > (which already are fixed up for this) and stay with the old 8+8 split for
> > character devices.  Note that Linux is about doing stuff right, not fast.
> 
> 	Wait, so ugly hacks that steal every remaining major

What hack to steal every remaining major?  Remember that Linus already said
that there won't be new static majors anyway.

> I've done the math with the current available majors.  I don't
> see 4000 disks there, and that is just life as it exists today,

were do you get this 4000 disks number from?  Every big system in practice
is attached to some EMC/LSI/IBM/whatever array anyway that virtualizes
away the actual disk.

Calculating with 120 left block major alone (and ignoring the fact that
most of the officially registered space is now free aswell with the new
major/minor less block device registration) this would be about 1900 disks.

Given that no shipping Linux version supports more than 256 (scsi) disks
this is enough for sensible seyups for a few years.

> years from now when 2.8 finally appears.  Like Andrew asked, please
> describe exactly how you'd support it.

I did repson to Andrew, go and read it - and play with the code a bit.

Re: [PATCH] register_blkdev

[Joel Becker]

On Sat, Mar 08, 2003 at 09:52:39PM +0000, Christoph Hellwig wrote:
> What hack to steal every remaining major?  Remember that Linus already said
> that there won't be new static majors anyway.

	Having more than one major for disks is a hack.  Already.

> were do you get this 4000 disks number from?  Every big system in practice
> is attached to some EMC/LSI/IBM/whatever array anyway that virtualizes
> away the actual disk.

	We've already got systems with 4000 disks attached.  Registered
with the system, even.  This isn't hiding behind some big array.  They
are part of the system.  No, it's not on Linux, because Linux can't
handle it.  But if the system wants to go Linux, Linux has to handle it.
And 1900 disks wont' cut it *today*.  Never mind 2 years from now.

Joel

-- 

Life's Little Instruction Book #80

	"Slow dance"

Joel Becker
Senior Member of Technical Staff
Oracle Corporation
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Sat, Mar 08, 2003 at 02:16:51PM -0800, Joel Becker wrote:
> On Sat, Mar 08, 2003 at 09:52:39PM +0000, Christoph Hellwig wrote:
> 	Having more than one major for disks is a hack.  Already.

Damn, to you actually read what I wrote in all previous mails?  THE MAJOR/MINOR
SPLIT IS GONE FOR BLOCK DEVICES.  There are just ranges, the only difference
with a bigger dev_t is that the total amount of claimed space can be bigger.

> 	We've already got systems with 4000 disks attached.  Registered
> with the system, even.  This isn't hiding behind some big array.  They
> are part of the system.  No, it's not on Linux, because Linux can't
> handle it.  But if the system wants to go Linux, Linux has to handle it.
> And 1900 disks wont' cut it *today*.  Never mind 2 years from now.

So if you need so damn lot why don't you start auditing the character drivers
now instead of whining?  

Re: [PATCH] register_blkdev

[Joel Becker]

On Sat, Mar 08, 2003 at 10:21:51PM +0000, Christoph Hellwig wrote:
> Damn, to you actually read what I wrote in all previous mails?  THE MAJOR/MINOR
> SPLIT IS GONE FOR BLOCK DEVICES.  There are just ranges, the only difference
> with a bigger dev_t is that the total amount of claimed space can be bigger.

	I understand what you've read.  I've merely been telling you
that there aren't enough ranges for the number of disks we'd like to
handle.  Never mind that a larger dev_t is significantly clearer, or
that a large minor space can help us move to a single disk major if we
want to go there.

> So if you need so damn lot why don't you start auditing the character drivers
> now instead of whining?  

	I've been in contact with Andreas.  I've been trying to get
stuff tested.  I'm ready to commit resources with tons of disks to
test as soon as the code is capable.  I'm not whining, I'm active.
Please, you're a smart guy, let's keep this civil.

Joel

-- 

"Nothing is wrong with California that a rise in the ocean level
 wouldn't cure."
        - Ross MacDonald

Joel Becker
Senior Member of Technical Staff
Oracle Corporation
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127

Re: [PATCH] register_blkdev

[Alan Cox]

On Sat, 2003-03-08 at 21:52, Christoph Hellwig wrote:
> > 	Wait, so ugly hacks that steal every remaining major
> 
> What hack to steal every remaining major?  Remember that Linus already said
> that there won't be new static majors anyway.

No vendor I have spoken too intends to care what Linus thinks about it.
Linus tried this in 2.4. We all got together to create a numbering
repository instead of letting Linus do it.

Re: [PATCH] register_blkdev

[Linus Torvalds]

On 8 Mar 2003, Alan Cox wrote:
> 
> No vendor I have spoken too intends to care what Linus thinks about it.
> Linus tried this in 2.4. We all got together to create a numbering
> repository instead of letting Linus do it.

I was right, though. Look at how useless the fixed numbers are getting.

I certainly agree that we'll need to open up the number space, but I 
really do think that the way to _manage_ it is something like what Greg 
pointed to - dynamic tols with "rules" on allocation, instead of the 
stupid static manual assignment thing.

We're pretty close to it already. I thought some Linux vendors are already 
starting to pick up on the hotplugging tools, simply because there are no 
real alternatives.

And once you do it that way, the static numbers are meaningless. And good 
riddance.

		Linus

Re: [PATCH] register_blkdev

[Alan Cox]

On Sat, 2003-03-08 at 22:36, Linus Torvalds wrote:
> I certainly agree that we'll need to open up the number space, but I 
> really do think that the way to _manage_ it is something like what Greg 
> pointed to - dynamic tols with "rules" on allocation, instead of the 
> stupid static manual assignment thing.

Greg's tools still have unsolved security holes in them. We still have
unsolved persistence of permissions and reuse problems. I think they are
soluble. The current insoluble dirty great security hole we have is
lack of vhangup for non tty devices (ie BSD revoke). Right now that
allows some quite nasty things to occur if you ever had console access.

> We're pretty close to it already. I thought some Linux vendors are already 
> starting to pick up on the hotplugging tools, simply because there are no 
> real alternatives.

For certain kinds of device yes.

> And once you do it that way, the static numbers are meaningless. And good 
> riddance.

Static naming/permissions management is current simply the best of
available evils for many things. With stuff like modem arrays on serial
ports its also neccessary to know what goes where. I'm all for moving to
setups when possible where things like SCSI volumes carry a volume name
and permission/acl data in the label

Re: [PATCH] register_blkdev

[Gerrit Huizenga]

On Sat, 08 Mar 2003 21:52:39 GMT, Christoph Hellwig wrote:
> What hack to steal every remaining major?  Remember that Linus already said
> that there won't be new static majors anyway.
> 
> > I've done the math with the current available majors.  I don't
> > see 4000 disks there, and that is just life as it exists today,
> 
> were do you get this 4000 disks number from?  Every big system in practice
> is attached to some EMC/LSI/IBM/whatever array anyway that virtualizes
> away the actual disk.

Actually, we have an internal IBM project about to ship that has
requested 5000 physical disks, each multipathed at least once to
each possible node.  They even supposedly have customers ready today.

Yes, they do a lot of virtualization, internal striping, etc. but
they still have done their own math and would like to support 5000
disks on all OS's, including Linux.  Not a problem for most of the
others from what I've heard.

gerrit

Re: [PATCH] register_blkdev

[Steven Dake]

This could easily be supported by removing the requirement that 16 
minors are used per disk.  If instead, partition minors were dynamcially 
allocated and created by userspace policies (or devfs), many thousands 
of disks could be used in the current scheme (assuming they don't have a 
bunch of partitions).  I think it is unlikely anyone would actually use 
more then one partition in a big disk setup, but I could be wrong.   If 
only one minor were used per disk, 10k disks could easily be supported 
by the current dev_t.

Of course, the way block devices that represent disks register with the 
system would have to change, but the current waste of minors by devices 
that never exist is rediculous anyway.

Thanks
-steve

Joel Becker wrote:

>On Sat, Mar 08, 2003 at 07:43:31PM +0000, Christoph Hellwig wrote:
>  
>
>>So people should have started working on it sooner.  If people really think
>>they need a 32bit dev_t for their $BIGNUM of disks (and I still don't buy
>>that argument) we should just introduce it and use it only for block devices
>>(which already are fixed up for this) and stay with the old 8+8 split for
>>character devices.  Note that Linux is about doing stuff right, not fast.
>>    
>>
>
>	Wait, so ugly hacks that steal every remaining major is doing it
>'right'?  I've done the math with the current available majors.  I don't
>see 4000 disks there, and that is just life as it exists today, not 2-3
>years from now when 2.8 finally appears.  Like Andrew asked, please
>describe exactly how you'd support it.
>
>Joel
>
>
>  
>

Re: [PATCH] register_blkdev

[Andries.Brouwer]

> the prototype changes you did which make absolutely no sense
> to get into 2.5 now when the functions will disappear before 2.6.

Maybe you are right.
But as I said, my goal is to give us a 32-bit dev_t.
It is not necessary to eliminate register_blkdev now,
or before 2.6, in order to reach that goal.
I agree completely that it should go away, and I moved it
in front of the function it is going to be merged with.

In fact I started on the patch to remove it, but the patch
got too large. Many places do register_blkdev early and
blk_register_region later. If the region is taken already
then allocated memory must be freed etc. Trivial work,
but a largish patch. Better to divide the work in steps.

Andries

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Fri, Mar 07, 2003 at 08:50:18PM +0100, Andries.Brouwer@cwi.nl wrote:
> > the prototype changes you did which make absolutely no sense
> > to get into 2.5 now when the functions will disappear before 2.6.
> 
> Maybe you are right.
> But as I said, my goal is to give us a 32-bit dev_t.
> It is not necessary to eliminate register_blkdev now,
> or before 2.6, in order to reach that goal.
> I agree completely that it should go away, and I moved it
> in front of the function it is going to be merged with.

Okay, and that part is fine with me, but please just leave the
prototype as-iw now, okay?

[PATCH] register_blkdev

[Andries.Brouwer]

The following patch does the following:

- static const char *blkdevs[MAX_BLKDEV]; disappears
- get_blkdev_list, (un)register_blkdev, __bdevname
  are moved from block_dev.c to genhd.c
- the third "fops" parameter of register_blkdev was unused;
  now removed everywhere
- zillions of places had printk("cannot get major") upon
  error return from register_blkdev; removed all of these
  and inserted a single printk in register_blkdev.

Of course the reason for the patch is that one fixed size
array is eliminated.

Andries

-----
diff -u --recursive --new-file -X /linux/dontdiff a/Documentation/cdrom/cdrom-standard.tex b/Documentation/cdrom/cdrom-standard.tex
--- a/Documentation/cdrom/cdrom-standard.tex	Fri Nov 22 22:40:24 2002
+++ b/Documentation/cdrom/cdrom-standard.tex	Fri Mar  7 19:02:00 2003
@@ -758,11 +758,8 @@
 \subsection{$Struct\ file_operations\ cdrom_fops$}
 
 The contents of this structure were described in section~\ref{cdrom.c}.
-As already stated, this structure should be used to register block
-devices with the kernel:
-$$
-register_blkdev(major, <name>, \&cdrom_fops);
-$$
+A pointer to this structure is assigned to the $fops$ field
+of the $struct gendisk$.
 
 \subsection{$Int\ register_cdrom( struct\ cdrom_device_info\ * cdi)$}
 
diff -u --recursive --new-file -X /linux/dontdiff a/arch/m68k/atari/stram.c b/arch/m68k/atari/stram.c
--- a/arch/m68k/atari/stram.c	Sat Jan 18 23:54:38 2003
+++ b/arch/m68k/atari/stram.c	Fri Mar  7 19:02:00 2003
@@ -1052,8 +1052,7 @@
 	if (!stram_disk)
 		return -ENOMEM;
 
-	if (register_blkdev( STRAM_MAJOR, "stram", &stram_fops)) {
-		printk(KERN_ERR "stram: Unable to get major %d\n", STRAM_MAJOR);
+	if (register_blkdev(STRAM_MAJOR, "stram")) {
 		put_disk(stram_disk);
 		return -ENXIO;
 	}
diff -u --recursive --new-file -X /linux/dontdiff a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
--- a/arch/um/drivers/ubd_kern.c	Tue Feb 11 09:14:17 2003
+++ b/arch/um/drivers/ubd_kern.c	Fri Mar  7 19:02:00 2003
@@ -673,7 +673,7 @@
 static int ubd_mc_init(void)
 {
 	mconsole_register_dev(&ubd_mc);
-	return(0);
+	return 0;
 }
 
 __initcall(ubd_mc_init);
@@ -682,29 +682,24 @@
 {
         int i;
 
-	ubd_dir_handle = devfs_mk_dir (NULL, "ubd", NULL);
-	if(register_blkdev(MAJOR_NR, "ubd", &ubd_blops)){
-		printk(KERN_ERR "ubd: unable to get major %d\n", MAJOR_NR);
+	ubd_dir_handle = devfs_mk_dir(NULL, "ubd", NULL);
+	if (register_blkdev(MAJOR_NR, "ubd"))
 		return -1;
-	}
 
 	blk_init_queue(&ubd_queue, do_ubd_request, &ubd_io_lock);
 	elevator_init(&ubd_queue, &elevator_noop);
 
-	if(fake_major != 0){
+	if (fake_major != 0) {
 		char name[sizeof("ubd_nnn\0")];
 
 		snprintf(name, sizeof(name), "ubd_%d", fake_major);
 		ubd_fake_dir_handle = devfs_mk_dir(NULL, name, NULL);
-		if(register_blkdev(fake_major, "ubd", &ubd_blops)){
-			printk(KERN_ERR "ubd: unable to get major %d\n",
-			       fake_major);
+		if (register_blkdev(fake_major, "ubd"))
 			return -1;
-		}
 	}
-	for(i = 0; i < MAX_DEV; i++) 
+	for (i = 0; i < MAX_DEV; i++) 
 		ubd_add(i);
-	return(0);
+	return 0;
 }
 
 late_initcall(ubd_init);
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/acorn/block/fd1772.c b/drivers/acorn/block/fd1772.c
--- a/drivers/acorn/block/fd1772.c	Wed Mar  5 10:47:19 2003
+++ b/drivers/acorn/block/fd1772.c	Fri Mar  7 19:02:00 2003
@@ -1539,11 +1539,9 @@
 			goto err_disk;
 	}
 
-	err = register_blkdev(MAJOR_NR, "fd", &floppy_fops);
-	if (err) {
-		printk("Unable to get major %d for floppy\n", MAJOR_NR);
+	err = register_blkdev(MAJOR_NR, "fd");
+	if (err)
 		goto err_disk;
-	}
 
 	err = -EBUSY;
 	if (request_dma(FLOPPY_DMA, "fd1772")) {
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/acorn/block/mfmhd.c b/drivers/acorn/block/mfmhd.c
--- a/drivers/acorn/block/mfmhd.c	Wed Mar  5 10:47:19 2003
+++ b/drivers/acorn/block/mfmhd.c	Fri Mar  7 19:02:00 2003
@@ -1267,11 +1267,9 @@
 	if (!request_region (mfm_addr, 10, "mfm"))
 		goto out1;
 
-	ret = register_blkdev(MAJOR_NR, "mfm", &mfm_fops);
-	if (ret) {
-		printk("mfm_init: unable to get major number %d\n", MAJOR_NR);
+	ret = register_blkdev(MAJOR_NR, "mfm");
+	if (ret)
 		goto out2;
-	}
 
 	/* Stuff for the assembler routines to get to */
 	hdc63463_baseaddress	= ioaddr(mfm_addr);
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/DAC960.c b/drivers/block/DAC960.c
--- a/drivers/block/DAC960.c	Sat Feb 15 20:41:56 2003
+++ b/drivers/block/DAC960.c	Fri Mar  7 19:02:00 2003
@@ -13,9 +13,6 @@
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   for complete details.
 
-  The author respectfully requests that any modifications to this software be
-  sent directly to him for evaluation and testing.
-
 */
 
 
@@ -2381,13 +2378,9 @@
   /*
     Register the Block Device Major Number for this DAC960 Controller.
   */
-  if (register_blkdev(MajorNumber, "dac960",
-			    &DAC960_BlockDeviceOperations) < 0)
-    {
-      DAC960_Error("UNABLE TO ACQUIRE MAJOR NUMBER %d - DETACHING\n",
-		   Controller, MajorNumber);
+  if (register_blkdev(MajorNumber, "dac960") < 0)
       return false;
-    }
+
   /*
     Initialize the I/O Request Queue.
   */
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/acsi.c b/drivers/block/acsi.c
--- a/drivers/block/acsi.c	Thu Jan  2 14:32:02 2003
+++ b/drivers/block/acsi.c	Fri Mar  7 19:02:00 2003
@@ -1613,7 +1613,6 @@
 
 
 int acsi_init( void )
-
 {
 	int err = 0;
 	int i, target, lun;
@@ -1623,8 +1622,7 @@
 #endif
 	if (!MACH_IS_ATARI || !ATARIHW_PRESENT(ACSI))
 		return 0;
-	if (register_blkdev( ACSI_MAJOR, "ad", &acsi_fops )) {
-		printk( KERN_ERR "Unable to get major %d for ACSI\n", ACSI_MAJOR );
+	if (register_blkdev(ACSI_MAJOR, "ad")) {
 		err = -EBUSY;
 		goto out1;
 	}
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/amiflop.c b/drivers/block/amiflop.c
--- a/drivers/block/amiflop.c	Thu Jan  2 14:32:02 2003
+++ b/drivers/block/amiflop.c	Fri Mar  7 19:02:00 2003
@@ -1754,10 +1754,9 @@
 	if (!AMIGAHW_PRESENT(AMI_FLOPPY))
 		return -ENXIO;
 
-	if (register_blkdev(FLOPPY_MAJOR,"fd",&floppy_fops)) {
-		printk("fd: Unable to get major %d for floppy\n",FLOPPY_MAJOR);
+	if (register_blkdev(FLOPPY_MAJOR,"fd"))
 		return -EBUSY;
-	}
+
 	/*
 	 *  We request DSKPTR, DSKLEN and DSKDATA only, because the other
 	 *  floppy registers are too spreaded over the custom register space
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/ataflop.c b/drivers/block/ataflop.c
--- a/drivers/block/ataflop.c	Thu Jan  2 14:32:02 2003
+++ b/drivers/block/ataflop.c	Fri Mar  7 19:02:00 2003
@@ -1929,10 +1929,8 @@
 		/* Hades doesn't have Atari-compatible floppy */
 		return -ENXIO;
 
-	if (register_blkdev(FLOPPY_MAJOR,"fd",&floppy_fops)) {
-		printk(KERN_ERR "Unable to get major %d for floppy\n",FLOPPY_MAJOR);
+	if (register_blkdev(FLOPPY_MAJOR,"fd"))
 		return -EBUSY;
-	}
 
 	for (i = 0; i < FD_MAX_UNITS; i++) {
 		unit[i].disk = alloc_disk(1);
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/cciss.c b/drivers/block/cciss.c
--- a/drivers/block/cciss.c	Wed Mar  5 10:47:19 2003
+++ b/drivers/block/cciss.c	Fri Mar  7 19:02:00 2003
@@ -2437,14 +2437,12 @@
 		return -ENODEV;
 	}
 
-	if( register_blkdev(COMPAQ_CISS_MAJOR+i, hba[i]->devname, &cciss_fops))
-	{
-		printk(KERN_ERR "cciss:  Unable to get major number "
-			"%d for %s\n", COMPAQ_CISS_MAJOR+i, hba[i]->devname);
+	if (register_blkdev(COMPAQ_CISS_MAJOR+i, hba[i]->devname)) {
 		release_io_mem(hba[i]);
 		free_hba(i);
-		return(-1);
+		return -1;
 	}
+
 	/* make sure the board interrupts are off */
 	hba[i]->access.set_intr_mask(hba[i], CCISS_INTR_OFF);
 	if( request_irq(hba[i]->intr, do_cciss_intr, 
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/cpqarray.c b/drivers/block/cpqarray.c
--- a/drivers/block/cpqarray.c	Wed Mar  5 10:47:19 2003
+++ b/drivers/block/cpqarray.c	Fri Mar  7 19:02:00 2003
@@ -339,11 +339,9 @@
 	for(i=0; i < nr_ctlr; i++) {
 	  	/* If this successful it should insure that we are the only */
 		/* instance of the driver */	
-		if (register_blkdev(COMPAQ_SMART2_MAJOR+i, hba[i]->devname, &ida_fops)) {
-                        printk(KERN_ERR "cpqarray: Unable to get major number %d for ida\n",
-                                COMPAQ_SMART2_MAJOR+i);
+		if (register_blkdev(COMPAQ_SMART2_MAJOR+i, hba[i]->devname))
                         continue;
-                }
+
 		hba[i]->access.set_intr_mask(hba[i], 0);
 		if (request_irq(hba[i]->intr, do_ida_intr,
 			SA_INTERRUPT|SA_SHIRQ, hba[i]->devname, hba[i])) {
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/floppy.c b/drivers/block/floppy.c
--- a/drivers/block/floppy.c	Mon Feb 24 23:02:47 2003
+++ b/drivers/block/floppy.c	Fri Mar  7 19:02:00 2003
@@ -4232,8 +4232,7 @@
 	}
 
 	devfs_mk_dir (NULL, "floppy", NULL);
-	if (register_blkdev(FLOPPY_MAJOR,"fd",&floppy_fops)) {
-		printk("Unable to get major %d for floppy\n",FLOPPY_MAJOR);
+	if (register_blkdev(FLOPPY_MAJOR,"fd")) {
 		err = -EBUSY;
 		goto out;
 	}
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/genhd.c b/drivers/block/genhd.c
--- a/drivers/block/genhd.c	Wed Mar  5 10:47:19 2003
+++ b/drivers/block/genhd.c	Fri Mar  7 19:13:42 2003
@@ -14,10 +14,16 @@
 #include <linux/slab.h>
 #include <linux/kmod.h>
 
+#define MAX_PROBE_HASH 255	/* random */
 
 static struct subsystem block_subsys;
 
-#define MAX_PROBE_HASH 23	/* random */
+/* Can be merged with blk_probe or deleted altogether. Later. */
+static struct blk_major_name {
+	struct blk_major_name *next;
+	int major;
+	char name[16];
+} *major_names[MAX_PROBE_HASH];
 
 static struct blk_probe {
 	struct blk_probe *next;
@@ -30,9 +36,132 @@
 } *probes[MAX_PROBE_HASH];
 
 /* index in the above - for now: assume no multimajor ranges */
+static inline int major_to_index(int major)
+{
+	return major % MAX_PROBE_HASH;
+}
+
 static inline int dev_to_index(dev_t dev)
 {
-	return MAJOR(dev) % MAX_PROBE_HASH;
+	return major_to_index(MAJOR(dev));
+}
+
+const char *__bdevname(dev_t dev)
+{
+	static char buffer[40];
+	char *name = "unknown-block";
+	unsigned int major = MAJOR(dev);
+	unsigned int minor = MINOR(dev);
+	int index = major_to_index(major);
+	struct blk_major_name *n;
+
+	down_read(&block_subsys.rwsem);
+	for (n = major_names[index]; n; n = n->next)
+		if (n->major == major)
+			break;
+	if (n)
+		name = &(n->name[0]);
+	sprintf(buffer, "%s(%u,%u)", name, major, minor);
+	up_read(&block_subsys.rwsem);
+
+	return buffer;
+}
+
+/* get block device names in somewhat random order */
+int get_blkdev_list(char *p)
+{
+	struct blk_major_name *n;
+	int i, len;
+
+	len = sprintf(p, "\nBlock devices:\n");
+
+	down_read(&block_subsys.rwsem);
+	for (i = 0; i < ARRAY_SIZE(major_names); i++) {
+		for (n = major_names[i]; n; n = n->next)
+			len += sprintf(p+len, "%3d %s\n",
+				       n->major, n->name);
+	}
+	up_read(&block_subsys.rwsem);
+
+	return len;
+}
+
+int register_blkdev(unsigned int major, const char *name)
+{
+	struct blk_major_name **n, *p;
+	int index, ret = 0;
+
+	if (devfs_only())
+		return 0;
+
+	/* temporary */
+	if (major == 0) {
+		down_read(&block_subsys.rwsem);
+		for (index = ARRAY_SIZE(major_names)-1; index > 0; index--)
+			if (major_names[index] == NULL)
+				break;
+		up_read(&block_subsys.rwsem);
+
+		if (index == 0) {
+			printk("register_blkdev: failed to get major for %s\n",
+			       name);
+			return -EBUSY;
+		}
+		ret = major = index;
+	}
+
+	p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
+	if (p == NULL)
+		return -ENOMEM;
+
+	p->major = major;
+	strncpy(p->name, name, sizeof(p->name)-1);
+	p->name[sizeof(p->name)-1] = 0;
+	p->next = 0;
+	index = major_to_index(major);
+
+	down_write(&block_subsys.rwsem);
+	for (n = &major_names[index]; *n; n = &(*n)->next)
+		if ((*n)->major == major)
+			break;
+	if (!*n)
+		*n = p;
+	else
+		ret = -EBUSY;
+	up_write(&block_subsys.rwsem);
+
+	if (ret < 0)
+		printk("register_blkdev: cannot get major %d for %s\n",
+		       major, name);
+
+	return ret;
+}
+
+/* todo: make void - error printk here */
+int unregister_blkdev(unsigned int major, const char *name)
+{
+	struct blk_major_name **n, *p;
+	int index;
+	int ret = 0;
+
+	if (devfs_only())
+		return 0;
+	index = major_to_index(major);
+
+	down_write(&block_subsys.rwsem);
+	for (n = &major_names[index]; *n; n = &(*n)->next)
+		if ((*n)->major == major)
+			break;
+	if (!*n || strcmp((*n)->name, name))
+		ret = -EINVAL;
+	else {
+		p = *n;
+		*n = p->next;
+		kfree(p);
+	}
+	up_write(&block_subsys.rwsem);
+
+	return ret;
 }
 
 /*
@@ -48,6 +177,9 @@
 	struct blk_probe *p = kmalloc(sizeof(struct blk_probe), GFP_KERNEL);
 	struct blk_probe **s;
 
+	if (p == NULL)
+		return;
+
 	p->owner = module;
 	p->get = probe;
 	p->lock = lock;
@@ -98,9 +230,9 @@
 
 /**
  * add_gendisk - add partitioning information to kernel list
- * @gp: per-device partitioning information
+ * @disk: per-device partitioning information
  *
- * This function registers the partitioning information in @gp
+ * This function registers the partitioning information in @disk
  * with the kernel.
  */
 void add_disk(struct gendisk *disk)
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/loop.c b/drivers/block/loop.c
--- a/drivers/block/loop.c	Wed Mar  5 10:47:19 2003
+++ b/drivers/block/loop.c	Fri Mar  7 19:02:00 2003
@@ -1017,11 +1017,8 @@
 		max_loop = 8;
 	}
 
-	if (register_blkdev(LOOP_MAJOR, "loop", &lo_fops)) {
-		printk(KERN_WARNING "Unable to get major number %d for loop"
-				    " device\n", LOOP_MAJOR);
+	if (register_blkdev(LOOP_MAJOR, "loop"))
 		return -EIO;
-	}
 
 	devfs_mk_dir(NULL, "loop", NULL);
 
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/nbd.c b/drivers/block/nbd.c
--- a/drivers/block/nbd.c	Sat Feb 15 20:41:56 2003
+++ b/drivers/block/nbd.c	Fri Mar  7 19:02:00 2003
@@ -564,9 +564,7 @@
 		nbd_dev[i].disk = disk;
 	}
 
-	if (register_blkdev(NBD_MAJOR, "nbd", &nbd_fops)) {
-		printk("Unable to get major number %d for NBD\n",
-		       NBD_MAJOR);
+	if (register_blkdev(NBD_MAJOR, "nbd")) {
 		err = -EIO;
 		goto out;
 	}
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c
--- a/drivers/block/paride/pcd.c	Tue Dec 10 18:42:30 2002
+++ b/drivers/block/paride/pcd.c	Fri Mar  7 19:02:00 2003
@@ -942,8 +942,7 @@
 	/* get the atapi capabilities page */
 	pcd_probe_capabilities();
 
-	if (register_blkdev(major, name, &pcd_bdops)) {
-		printk("pcd: unable to get major number %d\n", major);
+	if (register_blkdev(major, name)) {
 		for (unit = 0, cd = pcd; unit < PCD_UNITS; unit++, cd++)
 			put_disk(cd->disk);
 		return -1;
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c
--- a/drivers/block/paride/pd.c	Tue Dec 10 18:42:30 2002
+++ b/drivers/block/paride/pd.c	Fri Mar  7 19:02:00 2003
@@ -890,10 +890,9 @@
 {
 	if (disable)
 		return -1;
-	if (register_blkdev(major, name, &pd_fops)) {
-		printk("%s: unable to get major number %d\n", name, major);
+	if (register_blkdev(major, name))
 		return -1;
-	}
+
 	blk_init_queue(&pd_queue, do_pd_request, &pd_lock);
 	blk_queue_max_sectors(&pd_queue, cluster);
 
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c
--- a/drivers/block/paride/pf.c	Tue Dec 10 18:42:30 2002
+++ b/drivers/block/paride/pf.c	Fri Mar  7 19:02:00 2003
@@ -957,8 +957,7 @@
 		return -1;
 	pf_busy = 0;
 
-	if (register_blkdev(major, name, &pf_fops)) {
-		printk("pf_init: unable to get major number %d\n", major);
+	if (register_blkdev(major, name)) {
 		for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++)
 			put_disk(pf->disk);
 		return -1;
@@ -969,6 +968,7 @@
 
 	for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++) {
 		struct gendisk *disk = pf->disk;
+
 		if (!pf->present)
 			continue;
 		disk->private_data = pf;
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/ps2esdi.c b/drivers/block/ps2esdi.c
--- a/drivers/block/ps2esdi.c	Tue Dec 10 18:42:30 2002
+++ b/drivers/block/ps2esdi.c	Fri Mar  7 19:02:00 2003
@@ -146,13 +146,10 @@
 
 	int error = 0;
 
-	/* register the device - pass the name, major number and operations
-	   vector .                                                 */
-	if (register_blkdev(PS2ESDI_MAJOR, "ed", &ps2esdi_fops)) {
-		printk("%s: Unable to get major number %d\n", DEVICE_NAME,
-				PS2ESDI_MAJOR);
+	/* register the device - pass the name and major number */
+	if (register_blkdev(PS2ESDI_MAJOR, "ed"))
 		return -1;
-	}
+
 	/* set up some global information - indicating device specific info */
 	blk_init_queue(&ps2esdi_queue, do_ps2esdi_request, &ps2esdi_lock);
 
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/rd.c b/drivers/block/rd.c
--- a/drivers/block/rd.c	Wed Dec 18 12:51:59 2002
+++ b/drivers/block/rd.c	Fri Mar  7 19:02:00 2003
@@ -409,8 +409,7 @@
 			goto out;
 	}
 
-	if (register_blkdev(RAMDISK_MAJOR, "ramdisk", &rd_bd_op)) {
-		printk("RAMDISK: Could not get major %d", RAMDISK_MAJOR);
+	if (register_blkdev(RAMDISK_MAJOR, "ramdisk")) {
 		err = -EIO;
 		goto out;
 	}
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/swim3.c b/drivers/block/swim3.c
--- a/drivers/block/swim3.c	Tue Dec 10 18:42:30 2002
+++ b/drivers/block/swim3.c	Fri Mar  7 19:02:00 2003
@@ -1004,9 +1004,7 @@
 			goto out;
 	}
 
-	if (register_blkdev(FLOPPY_MAJOR, "fd", &floppy_fops)) {
-		printk(KERN_ERR"Unable to get major %d for floppy\n",
-				FLOPPY_MAJOR);
+	if (register_blkdev(FLOPPY_MAJOR, "fd")) {
 		err = -EBUSY;
 		goto out;
 	}
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/swim_iop.c b/drivers/block/swim_iop.c
--- a/drivers/block/swim_iop.c	Thu Jan  2 14:32:02 2003
+++ b/drivers/block/swim_iop.c	Fri Mar  7 19:02:00 2003
@@ -137,13 +137,12 @@
 	current_req = NULL;
 	floppy_count = 0;
 
-	if (!iop_ism_present) return -ENODEV;
+	if (!iop_ism_present)
+		return -ENODEV;
 
-	if (register_blkdev(FLOPPY_MAJOR, "fd", &floppy_fops)) {
-		printk(KERN_ERR "SWIM-IOP: Unable to get major %d for floppy\n",
-		       FLOPPY_MAJOR);
+	if (register_blkdev(FLOPPY_MAJOR, "fd"))
 		return -EBUSY;
-	}
+
 	blk_init_queue(&swim_queue, do_fd_request, &swim_iop_lock);
 	printk("SWIM-IOP: %s by Joshua M. Thompson (funaho@jurai.org)\n",
 		DRIVER_VERSION);
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/umem.c b/drivers/block/umem.c
--- a/drivers/block/umem.c	Sat Jan 18 23:54:28 2003
+++ b/drivers/block/umem.c	Fri Mar  7 19:02:00 2003
@@ -1145,11 +1145,9 @@
 	if (retval)
 		return -ENOMEM;
 
-	err = major_nr = register_blkdev(0, "umem", &mm_fops);
-	if (err < 0) {
-		printk(KERN_ERR "MM: Could not register block device\n");
+	err = major_nr = register_blkdev(0, "umem");
+	if (err < 0)
 		return -EIO;
-	}
 
 	for (i = 0; i < num_cards; i++) {
 		mm_gendisk[i] = alloc_disk(1 << MM_SHIFT);
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/xd.c b/drivers/block/xd.c
--- a/drivers/block/xd.c	Tue Dec 10 18:42:30 2002
+++ b/drivers/block/xd.c	Fri Mar  7 19:02:00 2003
@@ -154,9 +154,9 @@
 
 #ifdef MODULE
 	for (i = 4; i > 0; i--)
-		if(((xd[i] = xd[i-1]) >= 0) && !count)
+		if (((xd[i] = xd[i-1]) >= 0) && !count)
 			count = i;
-	if((xd[0] = count))
+	if ((xd[0] = count))
 		do_xd_setup(xd);
 #endif
 
@@ -170,10 +170,9 @@
 	}
 
 	err = -EBUSY;
-	if (register_blkdev(XT_DISK_MAJOR,"xd",&xd_fops)) {
-		printk("xd: Unable to get major number %d\n",XT_DISK_MAJOR);
+	if (register_blkdev(XT_DISK_MAJOR, "xd"))
 		goto out1;
-	}
+
 	devfs_mk_dir(NULL, "xd", NULL);
 	blk_init_queue(&xd_queue, do_xd_request, &xd_lock);
 	if (xd_detect(&controller,&address)) {
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/z2ram.c b/drivers/block/z2ram.c
--- a/drivers/block/z2ram.c	Thu Jan  2 14:32:02 2003
+++ b/drivers/block/z2ram.c	Fri Mar  7 19:02:00 2003
@@ -331,21 +331,18 @@
 static struct request_queue z2_queue;
 
 int __init 
-z2_init( void )
+z2_init(void)
 {
 
-    if ( !MACH_IS_AMIGA )
+    if (!MACH_IS_AMIGA)
 	return -ENXIO;
 
-    if ( register_blkdev( Z2RAM_MAJOR, DEVICE_NAME, &z2_fops ) )
-    {
-	printk( KERN_ERR DEVICE_NAME ": Unable to get major %d\n",
-	    Z2RAM_MAJOR );
+    if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
 	return -EBUSY;
-    }
+
     z2ram_gendisk = alloc_disk(1);
     if (!z2ram_gendisk) {
-	unregister_blkdev( Z2RAM_MAJOR, DEVICE_NAME );
+	unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
 	return -ENOMEM;
     }
     z2ram_gendisk->major = Z2RAM_MAJOR;
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/cdrom/aztcd.c b/drivers/cdrom/aztcd.c
--- a/drivers/cdrom/aztcd.c	Tue Dec 10 18:42:30 2002
+++ b/drivers/cdrom/aztcd.c	Fri Mar  7 19:02:00 2003
@@ -1910,12 +1910,12 @@
 	azt_disk = alloc_disk(1);
 	if (!azt_disk)
 		goto err_out;
-	if (register_blkdev(MAJOR_NR, "aztcd", &azt_fops) != 0) {
-		printk(KERN_WARNING "aztcd: Unable to get major %d for Aztech"
-		       " CD-ROM\n", MAJOR_NR);
+
+	if (register_blkdev(MAJOR_NR, "aztcd")) {
 		ret = -EIO;
 		goto err_out2;
 	}
+
 	blk_init_queue(&azt_queue, do_aztcd_request, &aztSpin);
 	blk_queue_hardsect_size(&azt_queue, 2048);
 	azt_disk->major = MAJOR_NR;
@@ -1931,7 +1931,7 @@
 	azt_invalidate_buffers();
 	aztPresent = 1;
 	aztCloseDoor();
-	return (0);
+	return 0;
 err_out2:
 	put_disk(azt_disk);
 err_out:
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/cdrom/cdu31a.c b/drivers/cdrom/cdu31a.c
--- a/drivers/cdrom/cdu31a.c	Fri Nov 22 22:40:52 2002
+++ b/drivers/cdrom/cdu31a.c	Fri Mar  7 19:02:00 2003
@@ -3368,11 +3368,8 @@
 	if (!request_region(cdu31a_port, 4, "cdu31a"))
 		goto errout3;
 
-	if (register_blkdev(MAJOR_NR, "cdu31a", &scd_bdops)) {
-		printk("Unable to get major %d for CDU-31a\n",
-		       MAJOR_NR);
+	if (register_blkdev(MAJOR_NR, "cdu31a"))
 		goto errout2;
-	}
 
 	disk = alloc_disk(1);
 	if (!disk)
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/cdrom/cm206.c b/drivers/cdrom/cm206.c
--- a/drivers/cdrom/cm206.c	Fri Nov 22 22:40:59 2002
+++ b/drivers/cdrom/cm206.c	Fri Mar  7 19:02:00 2003
@@ -1489,10 +1489,10 @@
 		goto out_probe;
 	}
 	printk(".\n");
-	if (register_blkdev(MAJOR_NR, "cm206", &cm206_bdops) != 0) {
-		printk(KERN_INFO "Cannot register for major %d!\n", MAJOR_NR);
+
+	if (register_blkdev(MAJOR_NR, "cm206"))
 		goto out_blkdev;
-	}
+
 	disk = alloc_disk(1);
 	if (!disk)
 		goto out_disk;
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/cdrom/gscd.c b/drivers/cdrom/gscd.c
--- a/drivers/cdrom/gscd.c	Tue Dec 10 18:42:30 2002
+++ b/drivers/cdrom/gscd.c	Fri Mar  7 19:02:00 2003
@@ -959,12 +959,11 @@
 	gscd_disk->fops = &gscd_fops;
 	sprintf(gscd_disk->disk_name, "gscd");
 
-	if (register_blkdev(MAJOR_NR, "gscd", &gscd_fops) != 0) {
-		printk(KERN_WARNING "GSCD: Unable to get major %d for GoldStar "
-		       "CD-ROM\n", MAJOR_NR);
+	if (register_blkdev(MAJOR_NR, "gscd")) {
 		ret = -EIO;
 		goto err_out2;
 	}
+
 	devfs_register(NULL, "gscd", DEVFS_FL_DEFAULT, MAJOR_NR, 0,
 		       S_IFBLK | S_IRUGO | S_IWUGO, &gscd_fops, NULL);
 
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/cdrom/mcd.c b/drivers/cdrom/mcd.c
--- a/drivers/cdrom/mcd.c	Fri Nov 22 22:40:49 2002
+++ b/drivers/cdrom/mcd.c	Fri Mar  7 19:02:00 2003
@@ -1068,8 +1068,7 @@
 		put_disk(disk);
 		return -EIO;
 	}
-	if (register_blkdev(MAJOR_NR, "mcd", &mcd_bdops) != 0) {
-		printk(KERN_ERR "mcd: Unable to get major %d for Mitsumi CD-ROM\n", MAJOR_NR);
+	if (register_blkdev(MAJOR_NR, "mcd")) {
 		put_disk(disk);
 		return -EIO;
 	}
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/cdrom/mcdx.c b/drivers/cdrom/mcdx.c
--- a/drivers/cdrom/mcdx.c	Fri Nov 22 22:40:41 2002
+++ b/drivers/cdrom/mcdx.c	Fri Mar  7 19:02:00 2003
@@ -1193,11 +1193,9 @@
 	}
 
 	xtrace(INIT, "init() register blkdev\n");
-	if (register_blkdev(MAJOR_NR, "mcdx", &mcdx_bdops) != 0) {
+	if (register_blkdev(MAJOR_NR, "mcdx")) {
 		release_region((unsigned long) stuffp->wreg_data,
 			       MCDX_IO_SIZE);
-		xwarn("%s=0x%3p,%d: Init failed. Can't get major %d.\n",
-		      MCDX, stuffp->wreg_data, stuffp->irq, MAJOR_NR);
 		kfree(stuffp);
 		put_disk(disk);
 		return 1;
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/cdrom/optcd.c b/drivers/cdrom/optcd.c
--- a/drivers/cdrom/optcd.c	Fri Nov 22 22:40:23 2002
+++ b/drivers/cdrom/optcd.c	Fri Mar  7 19:02:00 2003
@@ -2047,8 +2047,7 @@
 		put_disk(optcd_disk);
 		return -EIO;
 	}
-	if (register_blkdev(MAJOR_NR, "optcd", &opt_fops) != 0) {
-		printk(KERN_ERR "optcd: unable to get major %d\n", MAJOR_NR);
+	if (register_blkdev(MAJOR_NR, "optcd")) {
 		release_region(optcd_port, 4);
 		put_disk(optcd_disk);
 		return -EIO;
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/cdrom/sbpcd.c b/drivers/cdrom/sbpcd.c
--- a/drivers/cdrom/sbpcd.c	Wed Mar  5 10:47:19 2003
+++ b/drivers/cdrom/sbpcd.c	Fri Mar  7 19:02:00 2003
@@ -5795,15 +5795,14 @@
 	OUT(MIXER_data,0xCC); /* one nibble per channel, max. value: 0xFF */
 #endif /* SOUND_BASE */
 
-	if (register_blkdev(MAJOR_NR, major_name, &sbpcd_bdops) != 0)
-	{
-		msg(DBG_INF, "Can't get MAJOR %d for Matsushita CDROM\n", MAJOR_NR);
+	if (register_blkdev(MAJOR_NR, major_name)) {
 #ifdef MODULE
 		return -EIO;
 #else
 		goto init_done;
 #endif /* MODULE */
 	}
+
 	blk_init_queue(&sbpcd_queue, do_sbpcd_request, &sbpcd_lock);
 
 	devfs_mk_dir (NULL, "sbp", NULL);
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/cdrom/sjcd.c b/drivers/cdrom/sjcd.c
--- a/drivers/cdrom/sjcd.c	Fri Nov 22 22:40:51 2002
+++ b/drivers/cdrom/sjcd.c	Fri Mar  7 19:02:00 2003
@@ -1677,11 +1677,8 @@
 	printk("SJCD: sjcd=0x%x: ", sjcd_base);
 #endif
 
-	if (register_blkdev(MAJOR_NR, "sjcd", &sjcd_fops) != 0) {
-		printk("SJCD: Unable to get major %d for Sanyo CD-ROM\n",
-		       MAJOR_NR);
-		return (-EIO);
-	}
+	if (register_blkdev(MAJOR_NR, "sjcd"))
+		return -EIO;
 
 	blk_init_queue(&sjcd_queue, do_sjcd_request, &sjcd_lock);
 	blk_queue_hardsect_size(&sjcd_queue, 2048);
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/cdrom/sonycd535.c b/drivers/cdrom/sonycd535.c
--- a/drivers/cdrom/sonycd535.c	Thu Jan  2 14:32:02 2003
+++ b/drivers/cdrom/sonycd535.c	Fri Mar  7 19:02:00 2003
@@ -1546,9 +1546,7 @@
 		printk("IRQ%d, ", tmp_irq);
 	printk("using %d byte buffer\n", sony_buffer_size);
 
-	if (register_blkdev(MAJOR_NR, CDU535_HANDLE, &cdu_fops)) {
-		printk("Unable to get major %d for %s\n",
-				MAJOR_NR, CDU535_MESSAGE_NAME);
+	if (register_blkdev(MAJOR_NR, CDU535_HANDLE)) {
 		err = -EIO;
 		goto out1;
 	}
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
--- a/drivers/ide/ide-probe.c	Mon Feb 24 23:02:47 2003
+++ b/drivers/ide/ide-probe.c	Fri Mar  7 19:02:00 2003
@@ -1292,11 +1292,8 @@
 	/* we set it back to 1 if all is ok below */	
 	hwif->present = 0;
 
-	if (register_blkdev (hwif->major, hwif->name, ide_fops)) {
-		printk("%s: UNABLE TO GET MAJOR NUMBER %d\n",
-			hwif->name, hwif->major);
+	if (register_blkdev(hwif->major, hwif->name))
 		return 0;
-	}
 
 	if (alloc_disks(hwif) < 0)
 		goto out;
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/ide/legacy/hd.c b/drivers/ide/legacy/hd.c
--- a/drivers/ide/legacy/hd.c	Fri Nov 22 22:40:12 2002
+++ b/drivers/ide/legacy/hd.c	Fri Mar  7 19:02:00 2003
@@ -708,10 +708,10 @@
 static int __init hd_init(void)
 {
 	int drive;
-	if (register_blkdev(MAJOR_NR,"hd",&hd_fops)) {
-		printk("hd: unable to get major %d for hard disk\n",MAJOR_NR);
+
+	if (register_blkdev(MAJOR_NR,"hd"))
 		return -1;
-	}
+
 	blk_init_queue(&hd_queue, do_hd_request, &hd_lock);
 	blk_queue_max_sectors(&hd_queue, 255);
 	init_timer(&device_timer);
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/md/dm.c b/drivers/md/dm.c
--- a/drivers/md/dm.c	Thu Jan  9 18:07:11 2003
+++ b/drivers/md/dm.c	Fri Mar  7 19:02:00 2003
@@ -79,9 +79,8 @@
 		return -ENOMEM;
 
 	_major = major;
-	r = register_blkdev(_major, _name, &dm_blk_dops);
+	r = register_blkdev(_major, _name);
 	if (r < 0) {
-		DMERR("register_blkdev failed");
 		kmem_cache_destroy(_io_cache);
 		return r;
 	}
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/md/md.c b/drivers/md/md.c
--- a/drivers/md/md.c	Wed Mar  5 10:47:21 2003
+++ b/drivers/md/md.c	Fri Mar  7 19:13:00 2003
@@ -3214,11 +3214,10 @@
 			MD_MAJOR_VERSION, MD_MINOR_VERSION,
 			MD_PATCHLEVEL_VERSION, MAX_MD_DEVS, MD_SB_DISKS);
 
-	if (register_blkdev (MAJOR_NR, "md", &md_fops)) {
-		printk(KERN_ALERT "md: Unable to get major %d for md\n", MAJOR_NR);
-		return (-1);
-	}
-	devfs_mk_dir (NULL, "md", NULL);
+	if (register_blkdev(MAJOR_NR, "md"))
+		return -1;
+
+	devfs_mk_dir(NULL, "md", NULL);
 	blk_register_region(MKDEV(MAJOR_NR, 0), MAX_MD_DEVS, THIS_MODULE,
 				md_probe, NULL, NULL);
 	for (minor=0; minor < MAX_MD_DEVS; ++minor) {
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/message/i2o/i2o_block.c b/drivers/message/i2o/i2o_block.c
--- a/drivers/message/i2o/i2o_block.c	Wed Mar  5 10:47:21 2003
+++ b/drivers/message/i2o/i2o_block.c	Fri Mar  7 19:02:00 2003
@@ -1608,12 +1608,8 @@
 	/*
 	 *	Register the block device interfaces
 	 */
-
-	if (register_blkdev(MAJOR_NR, "i2o_block", &i2ob_fops)) {
-		printk(KERN_ERR "Unable to get major number %d for i2o_block\n",
-		       MAJOR_NR);
+	if (register_blkdev(MAJOR_NR, "i2o_block"))
 		return -EIO;
-	}
 
 	for (i = 0; i < MAX_I2OB; i++) {
 		struct gendisk *disk = alloc_disk(16);
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/mtd/ftl.c b/drivers/mtd/ftl.c
--- a/drivers/mtd/ftl.c	Wed Mar  5 10:47:21 2003
+++ b/drivers/mtd/ftl.c	Fri Mar  7 19:02:00 2003
@@ -1281,11 +1281,9 @@
 	static spinlock_t lock = SPIN_LOCK_UNLOCKED;
 	DEBUG(0, "$Id: ftl.c,v 1.39 2001/10/02 15:05:11 dwmw2 Exp $\n");
 
-	if (register_blkdev(FTL_MAJOR, "ftl", &ftl_blk_fops)) {
-		printk(KERN_NOTICE "ftl_cs: unable to grab major "
-		       "device number!\n");
+	if (register_blkdev(FTL_MAJOR, "ftl"))
 		return -EAGAIN;
-	}
+
 	blk_init_queue(&ftl_queue, &do_ftl_request, &lock);
 	register_mtd_user(&ftl_notifier);
 	return 0;
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/mtd/mtdblock.c b/drivers/mtd/mtdblock.c
--- a/drivers/mtd/mtdblock.c	Sat Feb 15 20:41:57 2003
+++ b/drivers/mtd/mtdblock.c	Fri Mar  7 19:02:00 2003
@@ -570,11 +570,10 @@
 int __init init_mtdblock(void)
 {
 	spin_lock_init(&mtdblks_lock);
-	if (register_blkdev(MAJOR_NR,DEVICE_NAME,&mtd_fops)) {
-		printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
-		       MTD_BLOCK_MAJOR);
+
+	if (register_blkdev(MAJOR_NR, DEVICE_NAME))
 		return -EAGAIN;
-	}
+
 #ifdef CONFIG_DEVFS_FS
 	devfs_mk_dir(NULL, DEVICE_NAME, NULL);
 #endif
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/mtd/mtdblock_ro.c b/drivers/mtd/mtdblock_ro.c
--- a/drivers/mtd/mtdblock_ro.c	Fri Nov 22 22:40:42 2002
+++ b/drivers/mtd/mtdblock_ro.c	Fri Mar  7 19:02:00 2003
@@ -240,20 +240,13 @@
 
 int __init init_mtdblock(void)
 {
-	int err;
-
-	if (register_blkdev(MAJOR_NR,DEVICE_NAME,&mtd_fops)) {
-		printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
-		       MTD_BLOCK_MAJOR);
-		err = -EAGAIN;
-		goto out;
-	}
+	if (register_blkdev(MAJOR_NR, DEVICE_NAME))
+		return -EAGAIN;
 
 	blk_init_queue(&mtdro_queue, &mtdblock_request, &mtdro_lock);
 	register_mtd_user(&notifier);
-	err = 0;
- out:
-	return err;
+
+	return 0;
 }
 
 static void __exit cleanup_mtdblock(void)
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/mtd/nftlcore.c b/drivers/mtd/nftlcore.c
--- a/drivers/mtd/nftlcore.c	Wed Mar  5 10:47:21 2003
+++ b/drivers/mtd/nftlcore.c	Fri Mar  7 19:02:00 2003
@@ -928,10 +928,8 @@
 	printk(KERN_INFO "NFTL driver: nftlcore.c $Revision: 1.82 $, nftlmount.c %s\n", nftlmountrev);
 #endif
 
-	if (register_blkdev(MAJOR_NR, "nftl", &nftl_fops)) {
-		printk("unable to register NFTL block device on major %d\n", MAJOR_NR);
+	if (register_blkdev(MAJOR_NR, "nftl"))
 		return -EBUSY;
-	}
 
 	blk_register_region(MKDEV(MAJOR_NR, 0), 256,
 			THIS_MODULE, nftl_probe, NULL, NULL);
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c
--- a/drivers/s390/block/dasd_genhd.c	Tue Dec 10 18:42:33 2002
+++ b/drivers/s390/block/dasd_genhd.c	Fri Mar  7 19:02:00 2003
@@ -60,11 +60,8 @@
 	}
 
 	/* Register block device. */
-	new_major = register_blkdev(major, "dasd", &dasd_device_operations);
+	new_major = register_blkdev(major, "dasd");
 	if (new_major < 0) {
-		MESSAGE(KERN_WARNING,
-			"Cannot register to major no %d, rc = %d",
-			major, new_major);
 		kfree(mi);
 		return new_major;
 	}
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/s390/block/xpram.c b/drivers/s390/block/xpram.c
--- a/drivers/s390/block/xpram.c	Tue Dec 10 18:42:33 2002
+++ b/drivers/s390/block/xpram.c	Fri Mar  7 19:02:00 2003
@@ -430,13 +430,11 @@
 	/*
 	 * Register xpram major.
 	 */
-	rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME, &xpram_devops);
-	if (rc < 0) {
-		PRINT_ERR("Can't get xpram major %d\n", XPRAM_MAJOR);
+	rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME);
+	if (rc < 0)
 		goto out;
-	}
 
-	devfs_mk_dir (NULL, "slram", NULL);
+	devfs_mk_dir(NULL, "slram", NULL);
 
 	/*
 	 * Assign the other needed values: make request function, sizes and
@@ -452,6 +450,7 @@
 	for (i = 0; i < xpram_devs; i++) {
 		struct gendisk *disk = xpram_disks[i];
 		char name[16];
+
 		xpram_devices[i].size = xpram_sizes[i] / 4;
 		xpram_devices[i].offset = offset;
 		offset += xpram_devices[i].size;
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/s390/char/tape_block.c b/drivers/s390/char/tape_block.c
--- a/drivers/s390/char/tape_block.c	Tue Dec 10 18:42:33 2002
+++ b/drivers/s390/char/tape_block.c	Fri Mar  7 19:02:00 2003
@@ -333,12 +333,10 @@
 	int rc;
 
 	/* Register the tape major number to the kernel */
-	rc = register_blkdev(tapeblock_major, "tBLK", &tapeblock_fops);
-	if (rc < 0) {
-		PRINT_ERR("can't get major %d for block device\n",
-			  tapeblock_major);
+	rc = register_blkdev(tapeblock_major, "tBLK");
+	if (rc < 0)
 		return rc;
-	}
+
 	if (tapeblock_major == 0)
 		tapeblock_major = rc;
 	PRINT_INFO("tape gets major %d for block device\n", tapeblock_major);
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/sbus/char/jsflash.c b/drivers/sbus/char/jsflash.c
--- a/drivers/sbus/char/jsflash.c	Fri Nov 22 22:40:41 2002
+++ b/drivers/sbus/char/jsflash.c	Fri Mar  7 19:02:00 2003
@@ -570,9 +570,7 @@
 		jsfd_disk[i] = disk;
 	}
 
-	if (register_blkdev(JSFD_MAJOR, "jsfd", &jsfd_fops)) {
-		printk("jsfd_init: unable to get major number %d\n",
-		    JSFD_MAJOR);
+	if (register_blkdev(JSFD_MAJOR, "jsfd")) {
 		err = -EIO;
 		goto out;
 	}
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/scsi/sd.c b/drivers/scsi/sd.c
--- a/drivers/scsi/sd.c	Wed Mar  5 10:47:26 2003
+++ b/drivers/scsi/sd.c	Fri Mar  7 19:02:00 2003
@@ -1389,14 +1389,9 @@
 
 	SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
 
-	for (i = 0; i < SD_MAJORS; i++) {
-		if (register_blkdev(sd_major(i), "sd", &sd_fops))
-			printk(KERN_NOTICE
-			       "Unable to get major %d for SCSI disk\n",
-			       sd_major(i));
-		else
+	for (i = 0; i < SD_MAJORS; i++)
+		if (register_blkdev(sd_major(i), "sd") == 0)
 			majors++;
-	}
 
 	if (!majors)
 		return -ENODEV;
@@ -1409,7 +1404,7 @@
 }
 
 /**
- *	exit_sd - exit point for this driver (when it is	a module).
+ *	exit_sd - exit point for this driver (when it is a module).
  *
  *	Note: this function unregisters this driver from the scsi mid-level.
  **/
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/scsi/sr.c b/drivers/scsi/sr.c
--- a/drivers/scsi/sr.c	Wed Mar  5 10:47:26 2003
+++ b/drivers/scsi/sr.c	Fri Mar  7 19:02:00 2003
@@ -835,7 +835,7 @@
 {
 	int rc;
 
-	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr", &sr_bdops);
+	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
 	if (rc)
 		return rc;
 	return scsi_register_device(&sr_template);
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/scsi/sym53c8xx_2/sym_hipd.c b/drivers/scsi/sym53c8xx_2/sym_hipd.c
--- a/drivers/scsi/sym53c8xx_2/sym_hipd.c	Wed Mar  5 10:47:26 2003
+++ b/drivers/scsi/sym53c8xx_2/sym_hipd.c	Fri Mar  7 19:02:00 2003
@@ -221,7 +221,7 @@
  */
 static void sym_soft_reset (hcb_p np)
 {
-	u_char istat;
+	u_char istat = 0;
 	int i;
 
 	if (!(np->features & FE_ISTAT1) || !(INB (nc_istat1) & SCRUN))
diff -u --recursive --new-file -X /linux/dontdiff a/fs/block_dev.c b/fs/block_dev.c
--- a/fs/block_dev.c	Sat Jan 18 23:54:40 2003
+++ b/fs/block_dev.c	Fri Mar  7 19:02:00 2003
@@ -436,56 +436,6 @@
 	spin_unlock(&bdev_lock);
 }
 
-static const char *blkdevs[MAX_BLKDEV];
-
-int get_blkdev_list(char * p)
-{
-	int i;
-	int len;
-
-	len = sprintf(p, "\nBlock devices:\n");
-	for (i = 0; i < MAX_BLKDEV ; i++) {
-		if (blkdevs[i])
-			len += sprintf(p+len, "%3d %s\n", i, blkdevs[i]);
-	}
-	return len;
-}
-
-int register_blkdev(unsigned int major, const char * name, struct block_device_operations *bdops)
-{
-	if (devfs_only())
-		return 0;
-	if (major == 0) {
-		for (major = MAX_BLKDEV-1; major > 0; major--) {
-			if (blkdevs[major] == NULL) {
-				blkdevs[major] = name;
-				return major;
-			}
-		}
-		return -EBUSY;
-	}
-	if (major >= MAX_BLKDEV)
-		return -EINVAL;
-	if (blkdevs[major])
-		return -EBUSY;
-	blkdevs[major] = name;
-	return 0;
-}
-
-int unregister_blkdev(unsigned int major, const char * name)
-{
-	if (devfs_only())
-		return 0;
-	if (major >= MAX_BLKDEV)
-		return -EINVAL;
-	if (!blkdevs[major])
-		return -EINVAL;
-	if (strcmp(blkdevs[major], name))
-		return -EINVAL;
-	blkdevs[major] = NULL;
-	return 0;
-}
-
 /*
  * This routine checks whether a removable media has been changed,
  * and invalidates all buffer-cache-entries in that case. This
@@ -786,18 +736,6 @@
 	return res;
 }
 
-const char *__bdevname(dev_t dev)
-{
-	static char buffer[32];
-	const char * name = blkdevs[MAJOR(dev)];
-
-	if (!name)
-		name = "unknown-block";
-
-	sprintf(buffer, "%s(%d,%d)", name, MAJOR(dev), MINOR(dev));
-	return buffer;
-}
-
 /**
  * lookup_bdev  - lookup a struct block_device by name
  *
diff -u --recursive --new-file -X /linux/dontdiff a/include/linux/fs.h b/include/linux/fs.h
--- a/include/linux/fs.h	Wed Mar  5 10:47:30 2003
+++ b/include/linux/fs.h	Fri Mar  7 19:02:00 2003
@@ -1033,7 +1033,7 @@
 #define putname(name)	kmem_cache_free(names_cachep, (void *)(name))
 
 enum {BDEV_FILE, BDEV_SWAP, BDEV_FS, BDEV_RAW};
-extern int register_blkdev(unsigned int, const char *, struct block_device_operations *);
+extern int register_blkdev(unsigned int, const char *);
 extern int unregister_blkdev(unsigned int, const char *);
 extern struct block_device *bdget(dev_t);
 extern int bd_acquire(struct inode *inode);

Re: [PATCH] register_blkdev

[Christoph Hellwig]

On Fri, Mar 07, 2003 at 07:49:40PM +0100, Andries.Brouwer@cwi.nl wrote:
> The following patch does the following:
> 
> - static const char *blkdevs[MAX_BLKDEV]; disappears
> - get_blkdev_list, (un)register_blkdev, __bdevname
>   are moved from block_dev.c to genhd.c
> - the third "fops" parameter of register_blkdev was unused;
>   now removed everywhere
> - zillions of places had printk("cannot get major") upon
>   error return from register_blkdev; removed all of these
>   and inserted a single printk in register_blkdev.

IMHO that's a bad change, (un)register_blkdev should just go away
completly.