[PATCH] Add option to bring up a device in initramfs

[PATCH] Add option to bring up a device in initramfs

[Dave Young]

Kdump support dump to raw device which could be on top of complex storage
such as multipath and iscsi which are standalone dracut modules.

Add a --device option to dracut which will add the device to host_devs so
dracut can add the dependent modules automaticlly and enable them in initramfs.

Signed-off-by: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Tested-by: Chao Wang <chaowang-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 dracut.8.asc |    3 +++
 dracut.sh    |    3 +++
 2 files changed, 6 insertions(+)

--- dracut.orig/dracut.sh
+++ dracut/dracut.sh
@@ -133,6 +133,7 @@ Creates initial ramdisk images for prelo
   --mount "[DEV] [MP] [FSTYPE] [FSOPTS]"
                         Mount device [DEV] on mountpoint [MP] with filesystem
                         [FSTYPE] and options [FSOPTS] in the initramfs
+  --device "[DEV]"      Bring up [DEV] in initramfs
   -i, --include [SOURCE] [TARGET]
                         Include the files in the SOURCE directory into the
                          Target directory in the final initramfs.
@@ -261,6 +262,7 @@ TEMP=$(unset POSIXLY_CORRECT; getopt \
     --long fscks: \
     --long add-fstab: \
     --long mount: \
+    --long device: \
     --long nofscks: \
     --long ro-mnt \
     --long kmoddir: \
@@ -327,6 +329,7 @@ while :; do
         --fscks)       push fscks_l              "$2"; shift;;
         --add-fstab)   push add_fstab_l          "$2"; shift;;
         --mount)       push fstab_lines          "$2"; shift;;
+        --device)      push host_devs            "$2"; shift;;
         --nofscks)     nofscks_l="yes";;
         --ro-mnt)      ro_mnt_l="yes";;
         -k|--kmoddir)  drivers_dir_l="$2"; shift;;
--- dracut.orig/dracut.8.asc
+++ dracut/dracut.8.asc
@@ -321,6 +321,9 @@ provide a valid _/etc/fstab_.
     Mount _<device>_ on _<mountpoint>_ with _<filesystem type>_ and _<filesystem
     options>_ in the initramfs
 
+**--device** _<device>_ ::
+    Bring up _<device>_ in initramfs
+
 **-i, --include** _<SOURCE>_ _<TARGET>_::
     include the files in the SOURCE directory into the
     TARGET directory in the final initramfs. If SOURCE is a file, it will be

Re: [PATCH] Add option to bring up a device in initramfs

[Vivek Goyal]

On Thu, Aug 09, 2012 at 11:08:48AM +0800, Dave Young wrote:
> 
> Kdump support dump to raw device which could be on top of complex storage
> such as multipath and iscsi which are standalone dracut modules.
> 
> Add a --device option to dracut which will add the device to host_devs so
> dracut can add the dependent modules automaticlly and enable them in initramfs.
> 

You have not specified any format for --device argument? What do you expect
there? Device name, UUID, udev persistent link, or what?

Secondly, do we need some extra code to make sure somebody waits for
this device to come up? Who makes sure that initqueue does not exit
till this device node comes up.

Thanks
Vivek

> Signed-off-by: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> Tested-by: Chao Wang <chaowang-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
>  dracut.8.asc |    3 +++
>  dracut.sh    |    3 +++
>  2 files changed, 6 insertions(+)
> 
> --- dracut.orig/dracut.sh
> +++ dracut/dracut.sh
> @@ -133,6 +133,7 @@ Creates initial ramdisk images for prelo
>    --mount "[DEV] [MP] [FSTYPE] [FSOPTS]"
>                          Mount device [DEV] on mountpoint [MP] with filesystem
>                          [FSTYPE] and options [FSOPTS] in the initramfs
> +  --device "[DEV]"      Bring up [DEV] in initramfs
>    -i, --include [SOURCE] [TARGET]
>                          Include the files in the SOURCE directory into the
>                           Target directory in the final initramfs.
> @@ -261,6 +262,7 @@ TEMP=$(unset POSIXLY_CORRECT; getopt \
>      --long fscks: \
>      --long add-fstab: \
>      --long mount: \
> +    --long device: \
>      --long nofscks: \
>      --long ro-mnt \
>      --long kmoddir: \
> @@ -327,6 +329,7 @@ while :; do
>          --fscks)       push fscks_l              "$2"; shift;;
>          --add-fstab)   push add_fstab_l          "$2"; shift;;
>          --mount)       push fstab_lines          "$2"; shift;;
> +        --device)      push host_devs            "$2"; shift;;
>          --nofscks)     nofscks_l="yes";;
>          --ro-mnt)      ro_mnt_l="yes";;
>          -k|--kmoddir)  drivers_dir_l="$2"; shift;;
> --- dracut.orig/dracut.8.asc
> +++ dracut/dracut.8.asc
> @@ -321,6 +321,9 @@ provide a valid _/etc/fstab_.
>      Mount _<device>_ on _<mountpoint>_ with _<filesystem type>_ and _<filesystem
>      options>_ in the initramfs
>  
> +**--device** _<device>_ ::
> +    Bring up _<device>_ in initramfs
> +
>  **-i, --include** _<SOURCE>_ _<TARGET>_::
>      include the files in the SOURCE directory into the
>      TARGET directory in the final initramfs. If SOURCE is a file, it will be

Re: [PATCH] Add option to bring up a device in initramfs

[Dave Young]

On 08/13/2012 11:10 PM, Vivek Goyal wrote:

> On Thu, Aug 09, 2012 at 11:08:48AM +0800, Dave Young wrote:
>>
>> Kdump support dump to raw device which could be on top of complex storage
>> such as multipath and iscsi which are standalone dracut modules.
>>
>> Add a --device option to dracut which will add the device to host_devs so
>> dracut can add the dependent modules automaticlly and enable them in initramfs.
>>
> 
> You have not specified any format for --device argument? What do you expect
> there? Device name, UUID, udev persistent link, or what?


It's a device name, should metion it in doc as well.

> 
> Secondly, do we need some extra code to make sure somebody waits for
> this device to come up? Who makes sure that initqueue does not exit
> till this device node comes up.


I see there's a wait-mount-dev.sh in 95fstab-sys module which is for
waiting for the mount needed dev.

Currently dracut maintains host_devs and host_fs_types, host_fs_types
are mainly used inst the fs kernel modules. Other than the filesystem
modules we should use host_devs instead, ie. introduce
for_each_host_devs for modules such as multipath and iscsi using.

Another issue is waiting for host_devs should be handled in generic code
instead of 95fstab-sys.

This patch need an update to address these issues IMHO.

> 
> Thanks
> Vivek
> 
>> Signed-off-by: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> Tested-by: Chao Wang <chaowang-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> ---
>>  dracut.8.asc |    3 +++
>>  dracut.sh    |    3 +++
>>  2 files changed, 6 insertions(+)
>>
>> --- dracut.orig/dracut.sh
>> +++ dracut/dracut.sh
>> @@ -133,6 +133,7 @@ Creates initial ramdisk images for prelo
>>    --mount "[DEV] [MP] [FSTYPE] [FSOPTS]"
>>                          Mount device [DEV] on mountpoint [MP] with filesystem
>>                          [FSTYPE] and options [FSOPTS] in the initramfs
>> +  --device "[DEV]"      Bring up [DEV] in initramfs
>>    -i, --include [SOURCE] [TARGET]
>>                          Include the files in the SOURCE directory into the
>>                           Target directory in the final initramfs.
>> @@ -261,6 +262,7 @@ TEMP=$(unset POSIXLY_CORRECT; getopt \
>>      --long fscks: \
>>      --long add-fstab: \
>>      --long mount: \
>> +    --long device: \
>>      --long nofscks: \
>>      --long ro-mnt \
>>      --long kmoddir: \
>> @@ -327,6 +329,7 @@ while :; do
>>          --fscks)       push fscks_l              "$2"; shift;;
>>          --add-fstab)   push add_fstab_l          "$2"; shift;;
>>          --mount)       push fstab_lines          "$2"; shift;;
>> +        --device)      push host_devs            "$2"; shift;;
>>          --nofscks)     nofscks_l="yes";;
>>          --ro-mnt)      ro_mnt_l="yes";;
>>          -k|--kmoddir)  drivers_dir_l="$2"; shift;;
>> --- dracut.orig/dracut.8.asc
>> +++ dracut/dracut.8.asc
>> @@ -321,6 +321,9 @@ provide a valid _/etc/fstab_.
>>      Mount _<device>_ on _<mountpoint>_ with _<filesystem type>_ and _<filesystem
>>      options>_ in the initramfs
>>  
>> +**--device** _<device>_ ::
>> +    Bring up _<device>_ in initramfs
>> +
>>  **-i, --include** _<SOURCE>_ _<TARGET>_::
>>      include the files in the SOURCE directory into the
>>      TARGET directory in the final initramfs. If SOURCE is a file, it will be



-- 
Thanks
Dave

Re: [PATCH] Add option to bring up a device in initramfs

[Vivek Goyal]

On Tue, Aug 14, 2012 at 02:27:27PM +0800, Dave Young wrote:
> On 08/13/2012 11:10 PM, Vivek Goyal wrote:
> 
> > On Thu, Aug 09, 2012 at 11:08:48AM +0800, Dave Young wrote:
> >>
> >> Kdump support dump to raw device which could be on top of complex storage
> >> such as multipath and iscsi which are standalone dracut modules.
> >>
> >> Add a --device option to dracut which will add the device to host_devs so
> >> dracut can add the dependent modules automaticlly and enable them in initramfs.
> >>
> > 
> > You have not specified any format for --device argument? What do you expect
> > there? Device name, UUID, udev persistent link, or what?
> 
> 
> It's a device name, should metion it in doc as well.
> 
> > 
> > Secondly, do we need some extra code to make sure somebody waits for
> > this device to come up? Who makes sure that initqueue does not exit
> > till this device node comes up.
> 
> 
> I see there's a wait-mount-dev.sh in 95fstab-sys module which is for
> waiting for the mount needed dev.
> 
> Currently dracut maintains host_devs and host_fs_types, host_fs_types
> are mainly used inst the fs kernel modules. Other than the filesystem
> modules we should use host_devs instead, ie. introduce
> for_each_host_devs for modules such as multipath and iscsi using.

I see that iscsi is using for_each_host_dev_fs, which has both device
and filesystem info. Same is the case with multipath.

May be add raw device in host_dev_fs with filesystem type as "raw" and
special case "raw" whoever relies on this info. There might be other
better ways to handle this though.

Thanks
Vivek