stand: stop using varargs for dv_open() implementations

[kevans]

Summary

commit de04d704a98 ("Use the actual struct devdesc at the start [...]")
cleaned up all of the *_devdesc implementations to embed struct devdesc
at the beginning of all of the derivatives, to remove some fragility and
generally clean things up a little bit.

Take it a step further and remove varargs from dv_open(). All of these
can assume that a devdesc, at a minimum, will be passed to them.

[tsoome]

stand/i386/libfirewire/firewire.c

179

we can use __unused there.

stand/libsa/geli/gelidev.c

203

and __unused here?

stand/uboot/uboot_disk.c

176

f is now __unused ?:)

stand/usb/storage/umass_loader.c

124

f is now __unused?

stand/userboot/userboot/host.c

136

also __unused?

stand/userboot/userboot/userboot_disk.c

158

f is now __unused?

[kevans]

sprinkle some __unused

[tsoome]

Hm, it seems, we do not need f in any of those instances? Should we just remove that argument?

stand/common/dev_net.c

120

f is unused

stand/common/md.c

123

f is unused

stand/common/vdisk.c

294

f is unused

stand/efi/libefi/efihttp.c

231

f is unused..

stand/efi/libefi/efipart.c

883

f is unused

stand/i386/libi386/biosdisk.c

839

f is unused...

stand/kboot/hostdisk.c

88

f is __unused

stand/libofw/ofw_disk.c

119

f is __unused

[kevans]

In D34923#791889, @tsoome wrote:

Hm, it seems, we do not need f in any of those instances? Should we just remove that argument?

I'm torn between that and removing the devdesc argument instead. The latter would be more consistent with the other callbacks:

157     int         (*dv_close)(struct open_file *f);                               
158     int         (*dv_ioctl)(struct open_file *f, u_long cmd, void *data);

Since we can derive the devdesc from the open_file, it'd be the most flexible option and consistent with the rest of the interface. We'd have to fix userboot to fake an open_file for a call there, but ubldr was already doing that so there's some precedent.

[kevans]

Remove the devdesc arg to dv_open() entirely. f->f_devdata is always a devdesc
for the initial open(), modulo one instance in userboot that calls dv_open()
manually. Adopt it to the new interface like we do in uboot and just fake a
properly constructed struct open_file to pass in.

This matches the other dv_open() methods which operate on a struct open_file.

[imp]

I think I love the direction
But it's scary how many routines know about disk_open... Even though it looks like it should be a dv_open routine ,it's not :( ... But I've had too much pain with disk.c and part.c of late, so maybe I'm biased.

stand/common/devopen.c

52 ↗

(On Diff #112641)

Love this change.

stand/i386/libfirewire/firewire.c

179

Doesn't need the second argument, right?

stand/i386/libi386/biosdisk.c

865

Not for this commit, but all these casts suggest two things to me:

1. We might want to have a macro to do the conversion.
2. We really should assert in disk_open that dev->d_dev->dv_type == DEVT_DISK

But maybe these are followup work.

stand/kboot/hostdisk.c

91

this will likely cause me a merge conflict, but this change is worth it.

stand/libofw/ofw_disk.c

123

similar comments about an assert here, which is why a wrapper to get the devdesc from f might be useful to have that assert buried in... But more just idle thoughts than a request for you to change this already longer than ideal size patch

stand/libsa/stand.h

139–140

These are OBE sine we declare this 6 lines later.

stand/usb/storage/umass_loader.c

47

drop second arg here, no?

124

second arg 86?

[kevans]

Address new comments, drop in some XXX notes for future work

[imp]

I'd leave out the d_size change at the moment since I'm not 100% sure that that's completely safe yet....

stand/common/dev_net.c

123

might be better to have this first so the variables are in alphabetical order... But this is also super-duper picky and likely doesn't matter if you don't want to change it.

stand/common/disk.c

241 ↗

(On Diff #112646)

I don't know of any place we create a disk_devdesc for a DEVT_DISK, but this is a good signpost for the future.

stand/libsa/stand.h

177

This snuck in...
And I think it's fine now (I fixed how i386_devdesc was declared to use unions), but since we're not yet using it it would be less risky to omit it.

[kevans]

stand/i386/libi386/biosdisk.c

865

Good points- dropping in some comments.

stand/libofw/ofw_disk.c

123

The problem with a macro for that in particular is that we can only rely on f->f_devdata being the devdesc during dv_open(). Most drivers won't replace it with their own devdata, but one or two off in efi/ land will. It's probably OK, it just needs a bit of care.

stand/libsa/stand.h

177

Whoops, sorry, I had screwed up on some squashing and this snuck in from the next commit (D34925) while I was fixing it