Hi Vladimir,
We have implemented this code to enable the ieee1275 hint for grub. We
had scenarios (in SLES) like the disk had PReP partition followed by an
LVM and, inside this LVM , the boot partition. So, we implemented this
code to make grub able to generate the hint. Without this code, we were
unable to find the hint for the boot process. And, in some scenarios,
due the amount of disks in the machine, the process could take a lot to
finish.
Shall we limit this function call specific to PowerPC? Something like
this below:
#ifdef __powerpc__
realname = get_slave_from_dm (name_buf);
if (realname)
{
free (name_buf);
name_buf = realname;
}
#endif
Please suggest us.
Thank you so much!
Regards,
Avnish Chouhan
On 2024-06-07 15:05, grub-devel-requ...@gnu.org wrote:
Send Grub-devel mailing list submissions to
grub-devel@gnu.org
------------------------------
Message: 4
Date: Fri, 7 Jun 2024 11:34:45 +0200
From: "Vladimir 'phcoder' Serbinenko" <phco...@gmail.com>
To: avnish <avn...@imap.linux.ibm.com>
Cc: The development of GNU GRUB <grub-devel@gnu.org>, Daniel Kiper
<daniel.ki...@oracle.com>, brk...@linux.ibm.com,
meghanaprak...@in.ibm.com, Diego Domingos <dieg...@br.ibm.com>
Subject: Re: [PATCH v3 2/6] ieee1275/powerpc: enables device mapper
discovery
Message-ID:
<caead8jn1buoycxsep0dqtv7vml6vycnfg3tsurligbrn9uy...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Le ven. 7 juin 2024, 10:34, avnish <avn...@imap.linux.ibm.com> a écrit
:
On 2024-06-06 21:04, Vladimir 'phcoder' Serbinenko wrote:
> 2 problems: * How does dm device ends up on ofpathname? It should be
> handled by grub internal logic in most cases and not end up in
> of-specific paths * Why not use existing devmapper functions already
> present in codebase? Le jeu. 6 juin 2024,
>
> 2 problems:
> * How does dm device ends up on ofpathname? It should be handled by
> grub internal logic in most cases and not end up in of-specific paths
> * Why not use existing devmapper functions already present in
> codebase?
>
Hi Vladimir,
Thank you so much for your response!
We have observed that whenever we are dealing with the devices like
"/dev/dm-*", the ofpath returns null.
It's expected behavior
To resolve this, as no such required functions has been implemented to
handle this kind of case. We have done changes based on the
requirement
that will look into /sys/block/dm-* devices and search slave
devices recursively inside slaves directory to find the root disk.
Installing on e.g. LVM is invalid. Only 3 cases can your approach work:
1) multipath
2) maybe RAID1 as well in some cases
3) if ofw assembles raid somehow
Which one do you have? We need more details.
This patch enables invalid configs like installing on LVM
Regards,
Avnish Chouhan
> Le jeu. 6 juin 2024, 14:40, Avnish Chouhan <avn...@linux.ibm.com> a
> écrit :
>
>> This patch enables the device mapper discovery on ofpath.c.
>> Currently,
>> when we are dealing with a device like /dev/dm-* the ofpath returns
>> null
>> since there is no function implemented to handle this case.
>>
>> This patch implements a function that will look into /sys/block/dm-*
>> devices and search recursively inside slaves directory to find the
>> root
>> disk.
>>
>> Signed-off-by: Diego Domingos <dieg...@br.ibm.com>
>> Signed-off-by: Avnish Chouhan <avn...@linux.ibm.com>
>> ---
>> grub-core/osdep/linux/ofpath.c | 64
>> +++++++++++++++++++++++++++++++++++++++++-
>> 1 file changed, 63 insertions(+), 1 deletion(-)
>>
>> diff --git a/grub-core/osdep/linux/ofpath.c
>> b/grub-core/osdep/linux/ofpath.c
>> index 0f5d54e9f2d..cc849d9c94c 100644
>> --- a/grub-core/osdep/linux/ofpath.c
>> +++ b/grub-core/osdep/linux/ofpath.c
>> @@ -37,6 +37,7 @@
>> #include <fcntl.h>
>> #include <errno.h>
>> #include <ctype.h>
>> +#include <dirent.h>
>>
>> #ifdef __sparc__
>> typedef enum
>> @@ -755,13 +756,74 @@ strip_trailing_digits (const char *p)
>> return new;
>> }
>>
>> +static char *
>> +get_slave_from_dm (const char * device)
>> +{
>> + char *curr_device, *tmp;
>> + char *directory;
>> + char *ret = NULL;
>> + directory = grub_strdup (device);
>> + tmp = get_basename (directory);
>> + curr_device = grub_strdup (tmp);
>> + *tmp = '\0';
>> +
>> + /* Recursively check for slaves devices so we can find the root
>> device */
>> + while ((curr_device[0] == 'd') && (curr_device[1] == 'm') &&
>> (curr_device[2] == '-'))
>> + {
>> + DIR *dp;
>> + struct dirent *ep;
>> + char* device_path;
>> + device_path = grub_xasprintf ("/sys/block/%s/slaves",
>> curr_device);
>> + dp = opendir (device_path);
>> +
>> + if (dp != NULL)
>> + {
>> + ep = readdir (dp);
>> +
>> + while (ep != NULL)
>> + {
>> + /* avoid some system directories */
>> + if (!strcmp(ep->d_name,"."))
>> + goto next_dir;
>> + if (!strcmp(ep->d_name,".."))
>> + goto next_dir;
>> +
>> + free (curr_device);
>> + free (ret);
>> + curr_device = grub_strdup (ep->d_name);
>> + ret = grub_xasprintf ("%s%s", directory,
>> curr_device);
>> + break;
>> +
>> + next_dir:
>> + ep = readdir (dp);
>> + continue;
>> + }
>> + closedir (dp);
>> + }
>> + else
>> + grub_util_warn (_("cannot open directory `%s'"),
>> device_path);
>> + free (device_path);
>> + }
>> + free (directory);
>> + free (curr_device);
>> +
>> + return ret;
>> +}
>> +
>> char *
>> grub_util_devname_to_ofpath (const char *sys_devname)
>> {
>> - char *name_buf, *device, *devnode, *devicenode, *ofpath;
>> + char *name_buf, *device, *devnode, *devicenode, *ofpath,
>> *realname;
>>
>> name_buf = xrealpath (sys_devname);
>>
>> + realname = get_slave_from_dm (name_buf);
>> + if (realname)
>> + {
>> + free (name_buf);
>> + name_buf = realname;
>> + }
>> +
>> device = get_basename (name_buf);
>> devnode = strip_trailing_digits (name_buf);
>> devicenode = strip_trailing_digits (device);
>>
>> _______________________________________________
>> Grub-devel mailing list
>> Grub-devel@gnu.org
>> https://lists.gnu.org/mailman/listinfo/grub-devel
>
>
> Links:
> ------
> [1]
>
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