[PATCHv3] hurd: Support device entries with @/dev/disk: qualifier

[Samuel Thibault]

Those are used with non-bootstrap disk drivers, for which libstore has to
open /dev/disk before calling device_open on it instead of on the device
master port.  Normally in that case all /dev/ entries also have the @/dev/disk:
qualifier, so we can just drop it.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

Message-Id: <20220223233413.wkk66pxp5p2q2wrf@begin>

---
Difference with v2: formatting, using xmalloc instead of malloc.

Difference with v1: better drop the @/dev/disk: qualifier right from
grub_util_hurd_get_disk_info so it benefits alls the callees and not
only grub_util_part_to_disk.

diff --git a/grub-core/osdep/hurd/getroot.c b/grub-core/osdep/hurd/getroot.c
index c66b206fa..5f0e366d1 100644
--- a/grub-core/osdep/hurd/getroot.c
+++ b/grub-core/osdep/hurd/getroot.c
@@ -112,9 +112,21 @@ grub_util_find_hurd_root_device (const char *path)
   if (strncmp (name, "device:", sizeof ("device:") - 1) == 0)
     {
       char *dev_name = name + sizeof ("device:") - 1;
-      size_t size = sizeof ("/dev/") - 1 + strlen (dev_name) + 1;
+      size_t size;
       char *next;
-      ret = malloc (size);
+
+      if (dev_name[0] == '@')
+        {
+          /* non-bootstrap disk driver, the /dev/ entry is normally set up with
+           * the same @. */
+          char *next_name = strchr (dev_name, ':');
+
+          if (next_name)
+            dev_name = next_name + 1;
+        }
+
+      size = sizeof ("/dev/") - 1 + strlen (dev_name) + 1;
+      ret = xmalloc (size);
       next = stpncpy (ret, "/dev/", size);
       stpncpy (next, dev_name, size - (next - ret));
     }
diff --git a/grub-core/osdep/hurd/hostdisk.c b/grub-core/osdep/hurd/hostdisk.c
index c47b5a5ea..73c442ae5 100644
--- a/grub-core/osdep/hurd/hostdisk.c
+++ b/grub-core/osdep/hurd/hostdisk.c
@@ -87,6 +87,21 @@ grub_util_hurd_get_disk_info (const char *dev, grub_uint32_t 
*secsize, grub_disk
          *parent = xmalloc (len+1);
          memcpy (*parent, data, len);
          (*parent)[len] = '\0';
+
+         if ((*parent)[0] == '@')
+           {
+             /* non-bootstrap disk driver, the /dev/ entry is normally set up 
with
+              * the same @. */
+             char *next_path = strchr (*parent, ':');
+
+             if (next_path)
+               {
+                 char *n = strdup (next_path + 1);
+
+                 free (*parent);
+                 *parent = n;
+               }
+           }
        }
     }
   if (offset)