From 5bc2a14ea50c1381dd557ff058788aa46c196b80 Mon Sep 17 00:00:00 2001
From: Michael Chang <[email protected]>
Date: Thu, 10 Feb 2022 22:16:58 +0800
Subject: [PATCH 123/272] 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 <[email protected]>
---
 grub-core/osdep/basic/no_platform.c |  6 +++++
 grub-core/osdep/unix/platform.c     | 34 +++++++++++++++++++++++++++++
 grub-core/osdep/windows/platform.c  |  7 ++++++
 include/grub/util/install.h         |  3 +++
 util/grub-install.c                 | 31 ++++++++++++++++++--------
 5 files changed, 72 insertions(+), 9 deletions(-)

diff --git a/grub-core/osdep/basic/no_platform.c b/grub-core/osdep/basic/no_platform.c
index d76c34c14..a9de0597d 100644
--- a/grub-core/osdep/basic/no_platform.c
+++ b/grub-core/osdep/basic/no_platform.c
@@ -44,3 +44,9 @@ grub_install_sgi_setup (const char *install_device,
 {
   grub_util_error ("%s", _("no SGI routines are available for your platform"));
 }
+
+char *
+grub_install_get_filesystem (const char *path)
+{
+  return NULL;
+}
\ No newline at end of file
diff --git a/grub-core/osdep/unix/platform.c b/grub-core/osdep/unix/platform.c
index de712211c..1edca359a 100644
--- a/grub-core/osdep/unix/platform.c
+++ b/grub-core/osdep/unix/platform.c
@@ -239,3 +239,37 @@ grub_install_sgi_setup (const char *install_device,
 	imgfile, destname, NULL });
   grub_util_warn ("%s", _("You will have to set `SystemPartition' and `OSLoader' manually."));
 }
+
+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;
+}
\ No newline at end of file
diff --git a/grub-core/osdep/windows/platform.c b/grub-core/osdep/windows/platform.c
index af04c1a1e..e84c4d897 100644
--- a/grub-core/osdep/windows/platform.c
+++ b/grub-core/osdep/windows/platform.c
@@ -434,3 +434,10 @@ grub_install_sgi_setup (const char *install_device,
 {
   grub_util_error ("%s", _("no SGI routines are available for your platform"));
 }
+
+
+char *
+grub_install_get_filesystem (const char *path)
+{
+  return NULL;
+}
\ No newline at end of file
diff --git a/include/grub/util/install.h b/include/grub/util/install.h
index e0decd784..8732a2494 100644
--- a/include/grub/util/install.h
+++ b/include/grub/util/install.h
@@ -247,6 +247,9 @@ void
 grub_install_sgi_setup (const char *install_device,
 			const char *imgfile, const char *destname);
 
+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 efef6d09e..397592be9 100644
--- a/util/grub-install.c
+++ b/util/grub-install.c
@@ -911,7 +911,6 @@ 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;
@@ -1089,8 +1088,10 @@ 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);
@@ -1111,20 +1112,32 @@ 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)
-- 
2.41.0