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* Re: 2.6.0-test1 devfs question
@ 2003-07-28  7:13 "Andrey Borzenkov" 
  2003-07-28  7:22 ` Andrew Morton
  0 siblings, 1 reply; 15+ messages in thread
From: "Andrey Borzenkov"  @ 2003-07-28  7:13 UTC (permalink / raw)
  To: "Andrew Morton" ; +Cc: linux-kernel, "Daniele Venzano" 


> 
> The patch is broken - 2.4 does /dev/md/2 as well.
> 
> So what is the bug?  Why are people suddenly having problems with this?
> 

Daniele did some debugging, result is:

=================
Buggy config
------------
GRUB command line: kernel (hd0,1)/testing root=/dev/md2
video=radeonfb:1024x768-32@60
As output there is only (copied by hand):

[...]

raid1: raid set md2 active with 2 out of 2 mirrors
md: ... autorun DONE.
create_dev: name=/dev/root dev=902 dname=md2
VFS: cannot open root device "md2" or md2
please append a correct "root=" boot option
Kernel panic: VFS: unable to mount root fs on md2
<STOP>
==================

the bug is almost for sure in init/do_mount_devfs.c:read_dir; it
allocates static buffer of size at most 2**MAX_ORDER and tries to
read the whole dir at once. md driver creates all minors in md_init
i.e. 256 (2**MINORBITS). MAX_ORDER default is 11 so we have at most
2K which is enough for appr. 200 entries; 256 do not fit :)

Daniel, please, could you change read_dir to just allocate bigger
buffer - 4K should do - and test once more?

I'll see what can be done. Anyone sees reason why normal directory
scan won't work here?

-andrey 


^ permalink raw reply	[flat|nested] 15+ messages in thread
* Re: 2.6.0-test1 devfs question
@ 2003-07-26 19:51 Andrey Borzenkov
  2003-07-26 20:50 ` Andrew Morton
  0 siblings, 1 reply; 15+ messages in thread
From: Andrey Borzenkov @ 2003-07-26 19:51 UTC (permalink / raw)
  To: linux-kernel; +Cc: Andrew Morton

> Is the problem simply that the device has moved from /dev/md1 to /dev/md/1?
> If so, is this change sufficient?
>
> diff -puN drivers/md/md.c~a drivers/md/md.c
> --- 25/drivers/md/md.c~a        2003-07-26 11:24:58.000000000 -0700
> +++ 25-akpm/drivers/md/md.c     2003-07-26 11:25:15.000000000 -0700
> @@ -3505,7 +3505,7 @@ int __init md_init(void)
>         for (minor=0; minor < MAX_MD_DEVS; ++minor) {
>                 devfs_mk_bdev(MKDEV(MAJOR_NR, minor),
>                                 S_IFBLK|S_IRUSR|S_IWUSR,
> -                               "md/%d", minor);
> +                               "md%d", minor);
>         }

should not such things be done by devfsd in user space? This patch makes it 
even more incompatible with 2.4 ...

^ permalink raw reply	[flat|nested] 15+ messages in thread
* Re: 2.6.0-test1 devfs question
@ 2003-07-25 18:53 Balram Adlakha
  2003-07-26 10:45 ` Wiktor Wodecki
  0 siblings, 1 reply; 15+ messages in thread
From: Balram Adlakha @ 2003-07-25 18:53 UTC (permalink / raw)
  To: linux-kernel; +Cc: wodecki

>Hello,

>I'm currently running at 2.6.0-test1-mm2-O8 and I wanted to give devfs a
>shot. I recompiled the kernel with the following settings:
>CONFIG_DEVFS_FS=y
>CONFIG_DEVFS_MOUNT=y
># CONFIG_DEVFS_DEBUG is not set

>As I read through the documentation (btw, devfs=nomount is mentioned in
>configure help but not in Documentation/filesystems/devfs/boot-options)
>I got the understanding that this shouldn't make any difference to the
>system right? After booting with this kernel there were lots of proper
>devfs devices in my dmesg (host0/ide0... scsi0/...) however, the system
>didn't came up (couldn't mount rootfs). It didn't even work when I
>enabled CONFIG_DEVFS_MOUNT.

>I'm not sure whether this is a bug in mount/nomount of devfs or if it's
>somewhere my fault/setup (root on raid1, various lvm2 devices on raid1/0
>devices)

>Any help would be greatly appreciated.


You need to change your /etc/fstab to reflect the new devfs device names,
ex: "/dev/discs/disc0/part1" instead of "/dev/hda1". You can also use devfsd (or some alternative) to make synlinks to the older devices and retain permissions etc... Also, without devfsd you cannot expect module autoloading as modules can't be automatically loaded when theres no device requesting them (in this case the device simply doesn't exist until module is loaded)

^ permalink raw reply	[flat|nested] 15+ messages in thread
* 2.6.0-test1 devfs question
@ 2003-07-25 11:08 Wiktor Wodecki
  2003-07-25 11:18 ` Wiktor Wodecki
  2003-07-26 11:12 ` Daniele Venzano
  0 siblings, 2 replies; 15+ messages in thread
From: Wiktor Wodecki @ 2003-07-25 11:08 UTC (permalink / raw)
  To: rgooch; +Cc: linux-kernel

[-- Attachment #1: Type: text/plain, Size: 916 bytes --]

Hello,

I'm currently running at 2.6.0-test1-mm2-O8 and I wanted to give devfs a
shot. I recompiled the kernel with the following settings:
CONFIG_DEVFS_FS=y
CONFIG_DEVFS_MOUNT=y
# CONFIG_DEVFS_DEBUG is not set

As I read through the documentation (btw, devfs=nomount is mentioned in
configure help but not in Documentation/filesystems/devfs/boot-options)
I got the understanding that this shouldn't make any difference to the
system right? After booting with this kernel there were lots of proper
devfs devices in my dmesg (host0/ide0... scsi0/...) however, the system
didn't came up (couldn't mount rootfs). It didn't even work when I
enabled CONFIG_DEVFS_MOUNT.

I'm not sure whether this is a bug in mount/nomount of devfs or if it's
somewhere my fault/setup (root on raid1, various lvm2 devices on raid1/0
devices)

Any help would be greatly appreciated.

-- 
Regards,

Wiktor Wodecki

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]

^ permalink raw reply	[flat|nested] 15+ messages in thread

end of thread, other threads:[~2003-07-28 15:44 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2003-07-28  7:13 2.6.0-test1 devfs question "Andrey Borzenkov" 
2003-07-28  7:22 ` Andrew Morton
2003-07-28 15:59   ` [BUG SQUISHED] " Daniele Venzano
  -- strict thread matches above, loose matches on Subject: below --
2003-07-26 19:51 Andrey Borzenkov
2003-07-26 20:50 ` Andrew Morton
2003-07-26 22:30   ` Andrey Borzenkov
2003-07-27  8:58     ` Daniele Venzano
2003-07-25 18:53 Balram Adlakha
2003-07-26 10:45 ` Wiktor Wodecki
     [not found]   ` <20030726175214.GA2535@localhost.localdomain>
     [not found]     ` <20030726183750.GB789@gmx.de>
     [not found]       ` <20030726201919.GA5166@localhost.localdomain>
2003-07-26 20:35         ` Wiktor Wodecki
2003-07-25 11:08 Wiktor Wodecki
2003-07-25 11:18 ` Wiktor Wodecki
2003-07-26 11:12 ` Daniele Venzano
2003-07-26 18:25   ` Andrew Morton
2003-07-27 11:17     ` Alan Cox

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