[RFC] Patch series to remove devfs [00/22]

[RFC] Patch series to remove devfs [00/22]

[Greg KH]

As everyone knows[1], devfs is going to be removed from the kernel soon.
To accomplish this, here is a series of patches (22 in all) that do just
that.  Surprisingly enough, devfs was almost everywhere in the kernel,
that's why it takes so many patches :)

Anyway, here's the whole series against 2.6.12-rc6-git4.  If some of
them don't make it through to lkml (due to size restrictions, or just
failing on a "taste" filter), you can find them all at:
	http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/gregkh-05-devfs/
along with a quilt series file to apply them with.

Andrew, please do not pick these up for your -mm tree.  Odds are it will
just cause too many conflicts to make it worth your while :)

Comments welcome.

Oh, and the best part?  Here's the summary of the diffstat:

  222 files changed, 112 insertions(+), 8545 deletions(-)

It's nice to remove code from the kernel for a change...

thanks,

greg k-h

[1] What?  You don't know this?  Didn't you get the memo[2]?  Did you
    miss the huge flame war almost a year ago[3]?  Are you living under
    a rock[4]?
[2] http://lxr.linux.no/source/Documentation/feature-removal-schedule.txt
[3] http://thread.gmane.org/gmane.linux.kernel/219278
[4] http://www.balloonplanet.com/shop/images/products/product_1788_small.jpg

Re: [RFC] Patch series to remove devfs [00/22]

[Adrian Bunk]

On Sat, Jun 11, 2005 at 12:43:27AM -0700, Greg KH wrote:
>...
> Comments welcome.
>...

Please don't remove the !CONFIG_DEVFS_FS dummies from devfs_fs_kernel.h.

I'm sure some driver maintainers will want to keep the functions in 
their code because they share their drivers between 2.4 and 2.6 .

Keeping a devfs_fs_kernel.h with dummy functions doesn't hurt, but it 
prevents version #ifdef's in drivers and/or the same dummy functions in 
some subsystem specific headers.

> thanks,
> 
> greg k-h
>...

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [RFC] Patch series to remove devfs [00/22]

[Greg KH]

On Sat, Jun 11, 2005 at 12:21:34PM +0200, Adrian Bunk wrote:
> On Sat, Jun 11, 2005 at 12:43:27AM -0700, Greg KH wrote:
> >...
> > Comments welcome.
> >...
> 
> Please don't remove the !CONFIG_DEVFS_FS dummies from devfs_fs_kernel.h.
> 
> I'm sure some driver maintainers will want to keep the functions in 
> their code because they share their drivers between 2.4 and 2.6 .

All drivers should be in the mainline kernel tree, so why would they
need this?  Remember, out-of-the-tree drivers are on their own...

thanks,

greg k-h

Re: [RFC] Patch series to remove devfs [00/22]

[Adrian Bunk]

On Sat, Jun 11, 2005 at 07:39:04AM -0700, Greg KH wrote:
> On Sat, Jun 11, 2005 at 12:21:34PM +0200, Adrian Bunk wrote:
> > On Sat, Jun 11, 2005 at 12:43:27AM -0700, Greg KH wrote:
> > >...
> > > Comments welcome.
> > >...
> > 
> > Please don't remove the !CONFIG_DEVFS_FS dummies from devfs_fs_kernel.h.
> > 
> > I'm sure some driver maintainers will want to keep the functions in 
> > their code because they share their drivers between 2.4 and 2.6 .
> 
> All drivers should be in the mainline kernel tree, so why would they
> need this?  Remember, out-of-the-tree drivers are on their own...

I'm talking about drivers in the mainline kernel tree.

In some cases the driver author supports both 2.4 and 2.6 and prefers to 
support them in one file. Sometimes he submits the latest version of his 
driver to Marcelo or Linus.

If you remove the global function dummies, you force every driver 
maintainer who works this way to add the function dummies to their 
drivers.

Yes, there are many places where 2.4 and 2.6 are not source compatible 
for good reasons. But if the effort for maintaining compatibility 
between 2.4 and 2.6 in one area is as easy as keeping a header file with 
some dummy funtions it's worth considering.

And keeping the compatibility stuff in one file instead of spreaded 
through the kernel sources makes the cleanup to remove the last 
occurences a few years from now easier.

> thanks,
> 
> greg k-h

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [RFC] Patch series to remove devfs [00/22]

[Christoph Hellwig]

On Sat, Jun 11, 2005 at 05:36:56PM +0200, Adrian Bunk wrote:
> Yes, there are many places where 2.4 and 2.6 are not source compatible 
> for good reasons. But if the effort for maintaining compatibility 
> between 2.4 and 2.6 in one area is as easy as keeping a header file with 
> some dummy funtions it's worth considering.

The devfs calls for 2.4 and 2.6 are totally incompatible.  And there's
a trivial way to support both 2.4 and 2.6 in this area:  don't support
devfs at all, it always was marked either experimental or deprecated
anyway.

Re: [RFC] Patch series to remove devfs [00/22]

[Adrian Bunk]

On Sat, Jun 11, 2005 at 04:41:07PM +0100, Christoph Hellwig wrote:
> On Sat, Jun 11, 2005 at 05:36:56PM +0200, Adrian Bunk wrote:
> > Yes, there are many places where 2.4 and 2.6 are not source compatible 
> > for good reasons. But if the effort for maintaining compatibility 
> > between 2.4 and 2.6 in one area is as easy as keeping a header file with 
> > some dummy funtions it's worth considering.
> 
> The devfs calls for 2.4 and 2.6 are totally incompatible.
>...

OK, it seems I've missed how much devfs changed during 2.5 times...

Simply discard my emails in this thread.

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [RFC] Patch series to remove devfs [00/22]

[Kay Sievers]

On Sat, Jun 11, 2005 at 05:36:56PM +0200, Adrian Bunk wrote:
> On Sat, Jun 11, 2005 at 07:39:04AM -0700, Greg KH wrote:
> > On Sat, Jun 11, 2005 at 12:21:34PM +0200, Adrian Bunk wrote:
> > > On Sat, Jun 11, 2005 at 12:43:27AM -0700, Greg KH wrote:
> > > >...
> > > > Comments welcome.
> > > >...
> > > 
> > > Please don't remove the !CONFIG_DEVFS_FS dummies from devfs_fs_kernel.h.
> > > 
> > > I'm sure some driver maintainers will want to keep the functions in 
> > > their code because they share their drivers between 2.4 and 2.6 .
> > 
> > All drivers should be in the mainline kernel tree, so why would they
> > need this?  Remember, out-of-the-tree drivers are on their own...
> 
> I'm talking about drivers in the mainline kernel tree.
> 
> In some cases the driver author supports both 2.4 and 2.6 and prefers to 
> support them in one file. Sometimes he submits the latest version of his 
> driver to Marcelo or Linus.
> 
> If you remove the global function dummies, you force every driver 
> maintainer who works this way to add the function dummies to their 
> drivers.
> 
> Yes, there are many places where 2.4 and 2.6 are not source compatible 
> for good reasons. But if the effort for maintaining compatibility 
> between 2.4 and 2.6 in one area is as easy as keeping a header file with 
> some dummy funtions it's worth considering.
> 
> And keeping the compatibility stuff in one file instead of spreaded 
> through the kernel sources makes the cleanup to remove the last 
> occurences a few years from now easier.

How do these 2.4+2.6 drivers integrate with sysfs? Without proper
2.6-driver-core integration they will not work anyway.

Kay

[2.6 patch] fix compile errors and warning after devfs removal patches

[Adrian Bunk]

The patch below fixes three compile errors and one compile warning after 
applying the devfs removal patches.

Signed-off-by: Adrian Bunk <bunk@stusta.de>

---

 drivers/ide/ide-tape.c |    1 -
 drivers/md/md.c        |    1 -
 init/do_mounts_md.c    |    2 +-
 init/do_mounts_rd.c    |    4 ++--
 4 files changed, 3 insertions(+), 5 deletions(-)

--- linux-2.6.12-rc6-mm1-full/init/do_mounts_rd.c.old	2005-06-11 20:18:09.000000000 +0200
+++ linux-2.6.12-rc6-mm1-full/init/do_mounts_rd.c	2005-06-11 20:19:14.000000000 +0200
@@ -262,8 +262,8 @@
 {
 	if (rd_prompt)
 		change_floppy("root floppy disk to be loaded into RAM disk");
-	create_dev("/dev/root", ROOT_DEV, root_device_name);
-	create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n), NULL);
+	create_dev("/dev/root", ROOT_DEV);
+	create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n));
 	return rd_load_image("/dev/root");
 }
 
--- linux-2.6.12-rc6-mm1-full/init/do_mounts_md.c.old	2005-06-11 20:20:08.000000000 +0200
+++ linux-2.6.12-rc6-mm1-full/init/do_mounts_md.c	2005-06-11 20:20:17.000000000 +0200
@@ -275,7 +275,7 @@
 
 void __init md_run_setup(void)
 {
-	create_dev("/dev/md0", MKDEV(MD_MAJOR, 0), "md/0");
+	create_dev("/dev/md0", MKDEV(MD_MAJOR, 0));
 	if (raid_noautodetect)
 		printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=noautodetect)\n");
 	else {
--- linux-2.6.12-rc6-mm1-full/drivers/ide/ide-tape.c.old	2005-06-11 20:41:08.000000000 +0200
+++ linux-2.6.12-rc6-mm1-full/drivers/ide/ide-tape.c	2005-06-11 20:42:00.000000000 +0200
@@ -4875,7 +4875,6 @@
 
 	idetape_setup(drive, tape, minor);
 
-	g->number = -1;
 	g->fops = &idetape_block_ops;
 	ide_register_region(g);
 
--- linux-2.6.12-rc6-mm1-full/drivers/md/md.c.old	2005-06-11 20:48:07.000000000 +0200
+++ linux-2.6.12-rc6-mm1-full/drivers/md/md.c	2005-06-11 20:49:16.000000000 +0200
@@ -3947,7 +3947,6 @@
 {
 	mddev_t *mddev;
 	struct list_head *tmp;
-	int i;
 	blk_unregister_region(MKDEV(MAJOR_NR,0), MAX_MD_DEVS);
 	blk_unregister_region(MKDEV(mdp_major,0), MAX_MD_DEVS << MdpMinorShift);
 

Re: [2.6 patch] fix compile errors and warning after devfs removal patches

[Greg KH]

On Sat, Jun 11, 2005 at 10:14:44PM +0200, Adrian Bunk wrote:
> The patch below fixes three compile errors and one compile warning after 
> applying the devfs removal patches.
> 
> Signed-off-by: Adrian Bunk <bunk@stusta.de>

Thanks a lot, I've incorporated these into my patch series.

greg k-h

Re: [RFC] Patch series to remove devfs [00/22]

[J.A. Magallon]

On 06.11, Greg KH wrote:
> As everyone knows[1], devfs is going to be removed from the kernel soon.
> To accomplish this, here is a series of patches (22 in all) that do just
> that.  Surprisingly enough, devfs was almost everywhere in the kernel,
> that's why it takes so many patches :)
> 

You missed this for -mm, do not know if they apply to mainline:

--- linux-2.6.11-jam25/drivers/scsi/ch.c.orig	2005-06-13 00:40:58.000000000 +0200
+++ linux-2.6.11-jam25/drivers/scsi/ch.c	2005-06-13 00:41:16.000000000 +0200
@@ -20,7 +20,6 @@
 #include <linux/interrupt.h>
 #include <linux/blkdev.h>
 #include <linux/completion.h>
-#include <linux/devfs_fs_kernel.h>
 #include <linux/ioctl32.h>
 #include <linux/compat.h>
 #include <linux/chio.h>			/* here are all the ioctls */
@@ -940,8 +939,6 @@
 	if (init)
 		ch_init_elem(ch);
 
-	devfs_mk_cdev(MKDEV(SCSI_CHANGER_MAJOR,ch->minor),
-		      S_IFCHR | S_IRUGO | S_IWUGO, ch->name);
 	class_device_create(ch_sysfs_class,
 			    MKDEV(SCSI_CHANGER_MAJOR,ch->minor),
 			    dev, "s%s", ch->name);
@@ -974,7 +971,6 @@
 
 	class_device_destroy(ch_sysfs_class,
 			     MKDEV(SCSI_CHANGER_MAJOR,ch->minor));
-	devfs_remove(ch->name);
 	kfree(ch->dt);
 	kfree(ch);
 	ch_devcount--;
--- linux-2.6.11-jam25/drivers/scsi/arcmsr/arcmsr.c.orig	2005-06-13 00:40:00.000000000 +0200
+++ linux-2.6.11-jam25/drivers/scsi/arcmsr/arcmsr.c	2005-06-13 00:40:33.000000000 +0200
@@ -101,7 +101,6 @@
 #include <linux/moduleparam.h>
 #include <linux/blkdev.h>
 #include <linux/timer.h>
-#include <linux/devfs_fs_kernel.h>
 #include <linux/mc146818rtc.h>
 #include <linux/reboot.h>
 #include <linux/sched.h>
@@ -1654,7 +1653,6 @@
 **	int                     attached;		            %% # of high level drivers attached to this %%
 **	int                     access_count;	            %% Count of open channels/mounts %%
 **	void                    *hostdata;		            %% available to low-level driver %%
-**	devfs_handle_t          de;                         %% directory for the device %%
 **	char                    type;
 **	char                    scsi_level;
 **	char                    vendor[8], model[16], rev[4];


--
J.A. Magallon <jamagallon()able!es>     \               Software is like sex:
werewolf!able!es                         \         It's better when it's free
Mandriva Linux release 2006.0 (Cooker) for i586
Linux 2.6.11-jam24 (gcc 4.0.0 (4.0.0-3mdk for Mandriva Linux release 2006.0))

Re: [RFC] Patch series to remove devfs [00/22]

[Greg KH]

On Sun, Jun 12, 2005 at 10:44:33PM +0000, J.A. Magallon wrote:
> 
> On 06.11, Greg KH wrote:
> > As everyone knows[1], devfs is going to be removed from the kernel soon.
> > To accomplish this, here is a series of patches (22 in all) that do just
> > that.  Surprisingly enough, devfs was almost everywhere in the kernel,
> > that's why it takes so many patches :)
> > 
> 
> You missed this for -mm, do not know if they apply to mainline:

This patch series was not for -mm, as my comments stated :)

But thanks for the patch anyway.

greg k-h

Re: [RFC] Patch series to remove devfs [00/22]

[J.A. Magallon]

On 06.13, Greg KH wrote:
> On Sun, Jun 12, 2005 at 10:44:33PM +0000, J.A. Magallon wrote:
> > 
> > On 06.11, Greg KH wrote:
> > > As everyone knows[1], devfs is going to be removed from the kernel soon.
> > > To accomplish this, here is a series of patches (22 in all) that do just
> > > that.  Surprisingly enough, devfs was almost everywhere in the kernel,
> > > that's why it takes so many patches :)
> > > 
> > 
> > You missed this for -mm, do not know if they apply to mainline:
> 
> This patch series was not for -mm, as my comments stated :)
> 

I shifted some offsets and am running it now...

--
J.A. Magallon <jamagallon()able!es>     \               Software is like sex:
werewolf!able!es                         \         It's better when it's free
Mandriva Linux release 2006.0 (Cooker) for i586
Linux 2.6.11-jam25 (gcc 4.0.0 (4.0.0-3mdk for Mandriva Linux release 2006.0))