grub2/0001-grub-install-bailout-root-device-probing.patch

From 58dcf7985b20de876a6fc44a591aa377d0a0302c Mon Sep 17 00:00:00 2001
From: Michael Chang <mchang@suse.com>
Date: Thu, 10 Feb 2022 22:16:58 +0800
Subject: [PATCH] grub-install: bailout root device probing

The root device is probed to test if the filesystem is btrfs in order to setup
boot configs for snapshot booting. However when the root device is a lvm thin
volume, due to lack in grub support, the probing will be errored out and entire
installation process aborts.

Here we call out stat to bailout the situation whenever grub fails to probe
filesystem in it's own right.

  stat -f -c %T /

The command is also used by grub-mkconfig for the same purpose.

Signed-off-by: Michael Chang <mchang@suse.com>
---
 grub-core/osdep/basic/no_platform.c |  5 +++++
 grub-core/osdep/unix/platform.c     | 34 +++++++++++++++++++++++++++++
 grub-core/osdep/windows/platform.c  |  6 +++++
 include/grub/util/install.h         |  3 +++
 util/grub-install.c                 | 31 ++++++++++++++++++--------
 5 files changed, 70 insertions(+), 9 deletions(-)

diff --git a/grub-core/osdep/basic/no_platform.c b/grub-core/osdep/basic/no_platform.c
index a173dafe90..dfbdd58e4e 100644
--- a/grub-core/osdep/basic/no_platform.c
+++ b/grub-core/osdep/basic/no_platform.c
@@ -51,3 +51,8 @@ grub_install_zipl (const char *d, int i, int f)
   grub_util_error ("%s", _("no zIPL routines are available for your platform"));
 }
 
+char *
+grub_install_get_filesystem (const char *path)
+{
+  return NULL;
+}
diff --git a/grub-core/osdep/unix/platform.c b/grub-core/osdep/unix/platform.c
index 4df143671a..68186480b2 100644
--- a/grub-core/osdep/unix/platform.c
+++ b/grub-core/osdep/unix/platform.c
@@ -250,3 +250,37 @@ grub_install_zipl (const char *dest, int install, int force)
 	"-z", dest, NULL }))
     grub_util_error (_("`%s' failed.\n"), PACKAGE"-zipl-setup");
 }
+
+char *
+grub_install_get_filesystem (const char *path)
+{
+  int fd;
+  pid_t pid;
+  FILE *fp;
+  ssize_t len;
+  char *buf = NULL;
+  size_t bufsz = 0;
+
+  pid = grub_util_exec_pipe ((const char * []){ "stat", "-f", "-c", "%T", path, NULL }, &fd);
+  if (!pid)
+    return NULL;
+
+  fp = fdopen (fd, "r");
+  if (!fp)
+    return NULL;
+
+  len = getline (&buf, &bufsz, fp);
+  if (len == -1)
+    {
+      free (buf);
+      fclose (fp);
+      return NULL;
+    }
+
+  fclose (fp);
+
+  if (len > 0 && buf[len - 1] == '\n')
+    buf[len - 1] = '\0';
+
+  return buf;
+}
diff --git a/grub-core/osdep/windows/platform.c b/grub-core/osdep/windows/platform.c
index 733c36d72c..1d2e356e6b 100644
--- a/grub-core/osdep/windows/platform.c
+++ b/grub-core/osdep/windows/platform.c
@@ -430,3 +430,9 @@ grub_install_zipl (const char *d, int i, int f)
 {
   grub_util_error ("%s", _("no zIPL routines are available for your platform"));
 }
+
+char *
+grub_install_get_filesystem (const char *path)
+{
+  return NULL;
+}
diff --git a/include/grub/util/install.h b/include/grub/util/install.h
index 154487b72b..456955c3d7 100644
--- a/include/grub/util/install.h
+++ b/include/grub/util/install.h
@@ -252,6 +252,9 @@ grub_install_sgi_setup (const char *install_device,
 void
 grub_install_zipl (const char *d, int i, int f);
 
+char *
+grub_install_get_filesystem (const char *path);
+
 int 
 grub_install_compress_gzip (const char *src, const char *dest);
 int 
diff --git a/util/grub-install.c b/util/grub-install.c
index 7bc5f84378..213f54a782 100644
--- a/util/grub-install.c
+++ b/util/grub-install.c
@@ -871,7 +871,6 @@ main (int argc, char *argv[])
   const char *efi_file = NULL;
   char **grub_devices;
   grub_fs_t grub_fs;
-  grub_fs_t root_fs;
   grub_device_t grub_dev = NULL;
   enum grub_install_plat platform;
   char *grubdir, *device_map;
@@ -1049,8 +1048,10 @@ main (int argc, char *argv[])
   grub_host_init ();
 
   {
-    char *rootdir_grub_devname;
-    grub_device_t rootdir_grub_dev;
+    grub_device_t rootdir_grub_dev = NULL;
+    char *rootdir_grub_devname = NULL;
+    char *root_fs_name = NULL;
+
     char *t = grub_util_path_concat (2, "/", rootdir);
 
     rootdir_path = grub_canonicalize_file_name (t);
@@ -1071,20 +1072,32 @@ main (int argc, char *argv[])
 		       rootdir_devices[0]);
 
     rootdir_grub_dev = grub_device_open (rootdir_grub_devname);
-    if (! rootdir_grub_dev)
-      grub_util_error ("%s", grub_errmsg);
+    if (!rootdir_grub_dev)
+      {
+	root_fs_name = grub_install_get_filesystem (t);
+	if (root_fs_name)
+	  grub_errno = 0;
+      }
+    else
+      {
+	grub_fs_t root_fs = grub_fs_probe (rootdir_grub_dev);
+	if (root_fs)
+	  root_fs_name = grub_strdup (root_fs->name);
+      }
 
-    root_fs = grub_fs_probe (rootdir_grub_dev);
-    if (!root_fs)
+    if (!root_fs_name)
       grub_util_error ("%s", grub_errmsg);
 
     if (config.is_suse_btrfs_snapshot_enabled
-	&& grub_strncmp(root_fs->name, "btrfs", sizeof ("btrfs") - 1) == 0)
+	&& root_fs_name
+	&& grub_strncmp(root_fs_name, "btrfs", sizeof ("btrfs") - 1) == 0)
       use_relative_path_on_btrfs = 1;
 
+    free (root_fs_name);
     free (t);
     free (rootdir_grub_devname);
-    grub_device_close (rootdir_grub_dev);
+    if (rootdir_grub_dev)
+      grub_device_close (rootdir_grub_dev);
   }
 
   switch (platform)
-- 
2.34.1