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,
> ZjQcmQRYFpfptBannerStart
>
> This Message Is From an External Sender
> This message came from outside your organization.
>
> Report Suspicious
>
> ZjQcmQRYFpfptBannerEnd
> 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 <avnish@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 <diegodo@br.ibm.com>
>> Signed-off-by: Avnish Chouhan <avnish@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]
> https://us-phishalarm-ewt.proofpoint.com/EWT/v1/AdhS1Rd-!-XFVHHiYfI50ul9XDgoDMf5HTGn83xsPPR4XT9wPzmu8earnN0GgLmGjgJ1wrY0OEeVCDtYQvZuy51BEuwbJ2Q36rjgqhgETNXQL18Hn2QOfpE6f2H9XOn8Mici5$