Btrfs - What to Read and other Questions
Hey Guys, I am reading through the btrfs code and am wondering what files/docs I need to read in order to start helping out with btrfs. In addition when you state size and offset in the page explaining On Disk Format, I am wondering what you mean by offset and size it the tables expanding definitions of certain key values to the disk layout of btrfs , I have an idea but just want to make sure I am understanding it correctly through :). Regards and Thanks, Nick ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: What part of the kernel code maintains /proc/modules
Stab in the dark - at boot, is it picking up a different module version >from an initramfs? > > > > >You a genius, man ! >Will double check but this should be. >Thanks a lot.___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: U64 Ordering in File System Code of Btrfs
On 14-08-28 02:12 AM, anupam kapoor wrote: >> [Thu, 28 Aug 2014 00:54:47 -0400]: "nick" (nick): > ,[ nick ] > | Hey Guys, > | Thanks for the help so far. I am wondering after reading the btrfs > | code for certain functions there seem to > | be a lot of u64 variable and function returns of this type. Is this > | common in file system due to the disk > | being in a certain format and depending on the CPU being big or small > | endian that this needed to not reorder > | the disk parts that are being read into main memory and preserve the data's > ordering? > | Cheers Nick > ` > on disk format is little-endian. > > have a look at https://btrfs.wiki.kernel.org/index.php/Main_Page for > more information. > > kind regards > anupam > Forget to check the wiki and found what I was looking for. In addition, the code docs for the kernel are some of the best I am ever seen, the only three that even compare are the Yocto Project, Arch Wiki and Red Hat docs. Now I understand why you guys state to read the docs first :). Cheers Nick ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Btrfs Issues
On 14-08-28 10:55 AM, valdis.kletni...@vt.edu wrote: > On Wed, 27 Aug 2014 21:30:54 -0700, Manish Katiyar said: > >>> No I just pulled it out and then I get this error. Maybe this is normally >>> when not unmounted? > >> This is expected then. It was middle of a journal transaction when you >> pulled the device out. > > I wonder if we'll get to watch Nick debug problems with btrfs's journal > recovery code next. :) > If you want me to do that it's fine. :) Nick ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: What part of the kernel code maintains /proc/modules
On Thu, 28 Aug 2014 09:41:18 -0700, StephanT said: > As shown above both have the same Version - they were built together on the > same system. If I unload and load back the usb-storage the (F) disappears. > After re-boot the (F) is back. Stab in the dark - at boot, is it picking up a different module version from an initramfs? pgpKLS1_Lzm6w.pgp Description: PGP signature ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: What part of the kernel code maintains /proc/modules
Hi,
Thanks for the answer. Still cannot understand:
-bash-4.1# uname -r
3.10.14-100.146887.clp6.x86_64
-bash-4.1# modinfo usb-storage.ko
filename: usb-storage.ko
license: GPL
description: USB Mass Storage driver for Linux
author: Matthew Dharm
alias: usb:v*p*d*dc*dsc*dp*ic08isc06ip50in*
... lots of aliases ...
alias: usb:v03EBp2002d0100dc*dsc*dp*ic*isc*ip*in*
depends:
intree: Y
vermagic: 3.10.14-100.146887.clp6.x86_64 SMP mod_unload
parm: option_zero_cd:ZeroCD mode (1=Force Modem (default), 2=Allow
CD-Rom (uint)
parm: swi_tru_install:TRU-Install mode (1=Full Logic (def), 2=Force
CD-Rom, 3=Force Modem) (uint)
parm: delay_use:seconds to delay before using a new device (uint)
parm: quirks:supplemental list of device IDs and their quirks (string)
As shown above both have the same Version - they were built together on the
same system. If I unload and load back the usb-storage the (F) disappears.
After re-boot the (F) is back.
Any idea why
Thanks.
On Thursday, August 28, 2014 7:53 AM, "valdis.kletni...@vt.edu"
wrote:
>
>
>On Wed, 27 Aug 2014 16:55:23 -0700, StephanT said:
>
>
>> Just want to know why in /proc/modules some of the modules are marked (F). Li
>ke:
>>
>> usb_storage 56610 0 - Live 0xa005d000 (F)
>
>kernel/modules.c has a function module_flags_taint():
>
>static size_t module_flags_taint(struct module *mod, char *buf)
>{
> size_t l = 0;
>
> if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
> buf[l++] = 'P';
> if (mod->taints & (1 << TAINT_OOT_MODULE))
> buf[l++] = 'O';
> if (mod->taints & (1 << TAINT_FORCED_MODULE))
> buf[l++] = 'F';
> if (mod->taints & (1 << TAINT_CRAP))
> buf[l++] = 'C';
> if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
> buf[l++] = 'E';
> /*
> * TAINT_FORCED_RMMOD: could be added.
> * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
> * apply to modules.
> */
> return l;
>}
>
>Somebody 'modprobe -f' that module into the kernel, and it may or may not
>actually work properly because it wasn't compiled against the kernel that
>is running. Hilarity can result if it's using a different definition for
>some random 'struct foo' than the rest of the kernel...
>
>
>
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Re: Btrfs Issues
On Wed, 27 Aug 2014 21:30:54 -0700, Manish Katiyar said: > > No I just pulled it out and then I get this error. Maybe this is normally > > when not unmounted? > This is expected then. It was middle of a journal transaction when you > pulled the device out. I wonder if we'll get to watch Nick debug problems with btrfs's journal recovery code next. :) pgpw1fUluWNG5.pgp Description: PGP signature ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: What part of the kernel code maintains /proc/modules
On Wed, 27 Aug 2014 16:55:23 -0700, StephanT said:
> Just want to know why in /proc/modules some of the modules are marked (F). Li
ke:
>
> usb_storage 56610 0 - Live 0xa005d000 (F)
kernel/modules.c has a function module_flags_taint():
static size_t module_flags_taint(struct module *mod, char *buf)
{
size_t l = 0;
if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
buf[l++] = 'P';
if (mod->taints & (1 << TAINT_OOT_MODULE))
buf[l++] = 'O';
if (mod->taints & (1 << TAINT_FORCED_MODULE))
buf[l++] = 'F';
if (mod->taints & (1 << TAINT_CRAP))
buf[l++] = 'C';
if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
buf[l++] = 'E';
/*
* TAINT_FORCED_RMMOD: could be added.
* TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
* apply to modules.
*/
return l;
}
Somebody 'modprobe -f' that module into the kernel, and it may or may not
actually work properly because it wasn't compiled against the kernel that
is running. Hilarity can result if it's using a different definition for
some random 'struct foo' than the rest of the kernel...
pgpWknhGCI85Y.pgp
Description: PGP signature
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What part of the kernel code maintains /proc/modules
Hi, Just want to know why in /proc/modules some of the modules are marked (F). Like: usb_storage 56610 0 - Live 0xa005d000 (F) Thanks, Stephan. ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Kernel Programming
On Thu, 28 Aug 2014 15:33:21 +0530, Prudhvee Narasimha Sadha said: > Hi, I have learnt the basic OS concepts and I'm pretty good at c. > Now I need to really work on it. *WHY* do you "need" to work on it? Do you just want something for your resume? Has your boss ordered you to write a specific piece of kernel code or you'll be fired? You have a piece of hardware that isn't supported yet? You just want to give back to the community? (If this, then just build and run linux-next kernels and report any problems. We need good QA and testing more than we need more newbie programmers) pgpLPxKG_P7qy.pgp Description: PGP signature ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Kernel Programming
Start with eudyptula challenge : http://eudyptula-challenge.org/ 2014-08-28 12:03 UTC+02:00, Prudhvee Narasimha Sadha : > Hi, I have learnt the basic OS concepts and I'm pretty good at c. > Now I need to really work on it. Can you please help me with some basic > programs, how to approach and how to work on it. > > Thank you in advance. :) > -- « On ne résout pas un problème avec les modes de pensée qui l’ont engendré. » « You cannot solve current problems with current thinking. Current problems are the result of current thinking » ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Kernel Programming
Hi, I have learnt the basic OS concepts and I'm pretty good at c. Now I need to really work on it. Can you please help me with some basic programs, how to approach and how to work on it. Thank you in advance. :) ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Board and OS suggestion
Sorry will take care of that On Thu, Aug 28, 2014 at 11:56 AM, Kernel Apprentice < kernelapprent...@gmail.com> wrote: > I'm a Kernel noob myself, but you do realise this is the mailing list for > people that are trying to get into Linux Kernel Development and thus > completely unrelated to any other Operating Systems? > > Secure Os means something like tiny os available http://www.tinyos.net/ > or SEL4 http://ssrg.nicta.com/projects/seL4/ > > Any board has wifi connectivity? > > > > On Thu, Aug 28, 2014 at 10:38 AM, Kristofer Hallin < > kristofer.hal...@gmail.com> wrote: > >> What do you mean with a secure OS? What do you need it to do? >> >> (Also, is this related to the kernel?) >> On 28 Aug 2014 07:04, "Robert Clove" wrote: >> >>>Hi All, >>> >>> >>> As much of you will be doing experiments i need your advice. >>> I want to run some secure OS on an embedded platform like raspberry pi >>> or beagle board. >>> Can you suggest me which board is good and any secure OS that you have >>> try'ed? >>> Any board having wi fi connectivity will be an advantage. >>> >>> >>> Regards >>> >>> ___ >>> Kernelnewbies mailing list >>> Kernelnewbies@kernelnewbies.org >>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >>> >>> > > > ___ > Kernelnewbies mailing > listKernelnewbies@kernelnewbies.orghttp://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > > ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
