From 3f07270d83a48862921fbf83cdb7d5535c51b3aa Mon Sep 17 00:00:00 2001
From: nilusyi <nilusyi@tencent.com>
Date: Mon, 1 Apr 2024 15:52:52 +0800
Subject: [PATCH 030/272] grub-install: force jorunal draining tp emsure data
 integrity

In XFS, the system would end up in unbootable state if an abrupt power
off after grub-install is occuring. It can be easily reproduced with.

  grub-install /dev/vda; reboot -f

The grub error would show many different kinds of corruption in
filesystem and the problem boils down to incompleted journal transaction
which would leave pending writes behind in the on-disk journal. It is
therefore necessary to recover the system via re-mounting the filesystem
from linux system that all pending journal log can be replayed.

On the other hand if journal draining can be enforced by grub-install
then it can bring more resilience to such abrupt power loss. The fsync
is not enough here for XFS, because that only writes in-memory log to
on-disk (ie makes sure broken state can be repaired). Unfortunately
there's no designated system call to serve solely for the journal
draining, so it can only be achieved via fsfreeze system call that the
journal draining can happen as a byproduct during the process.

This patch adds fsfreeze/unfreeze at the end of grub-install to induce
journal draining on journaled file system. However btrfs is excluded
from the list as it is using fsync to drain journal and also is not
desired as reportedly having negative side effect. With this patch
applied, the boot falilure can no longer be reproduced with above
procedure.

v2:
Fix boot failure after kdump due to the content of grub.cfg is not
completed with pending modificaton in xfs journal (bsc#1186975)

Signed-off-by: Michael Chang <mchang@suse.com>
---
 Makefile.util.def                    |  3 ++
 grub-core/osdep/basic/journaled_fs.c | 26 +++++++++++++++
 grub-core/osdep/journaled_fs.c       |  5 +++
 grub-core/osdep/linux/journaled_fs.c | 48 ++++++++++++++++++++++++++++
 include/grub/util/install.h          |  2 ++
 util/grub-install.c                  | 19 +++++++++++
 util/grub-mkconfig.in                | 10 ++++++
 7 files changed, 113 insertions(+)
 create mode 100644 grub-core/osdep/basic/journaled_fs.c
 create mode 100644 grub-core/osdep/journaled_fs.c
 create mode 100644 grub-core/osdep/linux/journaled_fs.c

diff --git a/Makefile.util.def b/Makefile.util.def
index 55a9e7ce7..8a74ae0e7 100644
--- a/Makefile.util.def
+++ b/Makefile.util.def
@@ -667,6 +667,9 @@ program = {
   common = util/resolve.c;
   common = grub-core/kern/emu/argp_common.c;
   common = grub-core/osdep/init.c;
+  common = grub-core/osdep/journaled_fs.c;
+  extra_dist = grub-core/osdep/basic/journaled_fs.c;
+  extra_dist = grub-core/osdep/linux/journaled_fs.c;
 
   ldadd = '$(LIBLZMA)';
   ldadd = libgrubmods.a;
diff --git a/grub-core/osdep/basic/journaled_fs.c b/grub-core/osdep/basic/journaled_fs.c
new file mode 100644
index 000000000..9d8245704
--- /dev/null
+++ b/grub-core/osdep/basic/journaled_fs.c
@@ -0,0 +1,26 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2010,2011,2012,2013  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/util/install.h>
+
+int
+grub_install_sync_fs_journal (const char *path)
+{
+  return 1;
+}
+
diff --git a/grub-core/osdep/journaled_fs.c b/grub-core/osdep/journaled_fs.c
new file mode 100644
index 000000000..fa5d0a199
--- /dev/null
+++ b/grub-core/osdep/journaled_fs.c
@@ -0,0 +1,5 @@
+#ifdef __linux__
+#include "linux/journaled_fs.c"
+#else
+#include "basic/journaled_fs.c"
+#endif
diff --git a/grub-core/osdep/linux/journaled_fs.c b/grub-core/osdep/linux/journaled_fs.c
new file mode 100644
index 000000000..0fa8360b1
--- /dev/null
+++ b/grub-core/osdep/linux/journaled_fs.c
@@ -0,0 +1,48 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2010,2011,2012,2013  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <fcntl.h>
+#include <linux/fs.h>
+#include <sys/ioctl.h>
+#include <errno.h>
+#include <grub/util/install.h>
+
+int
+grub_install_sync_fs_journal (const char *path)
+{
+  int fd, ret;
+
+  fd = open (path, O_RDONLY);
+
+  if (fd == -1)
+    return 1;
+
+  if (ioctl (fd, FIFREEZE, 0) == 0)
+    {
+      ioctl(fd, FITHAW, 0);
+      ret = 1;
+    }
+  else if (errno == EOPNOTSUPP)
+    ret = 1;
+  else
+    ret = 0;
+
+  close (fd);
+  return ret;
+}
+
diff --git a/include/grub/util/install.h b/include/grub/util/install.h
index 35cf17a8d..7c44e3d0d 100644
--- a/include/grub/util/install.h
+++ b/include/grub/util/install.h
@@ -297,4 +297,6 @@ grub_set_install_backup_ponr (void)
 }
 #endif
 
+int
+grub_install_sync_fs_journal (const char *path);
 #endif
diff --git a/util/grub-install.c b/util/grub-install.c
index 7dc5657bb..453e9b18f 100644
--- a/util/grub-install.c
+++ b/util/grub-install.c
@@ -42,6 +42,7 @@
 #include <grub/emu/config.h>
 #include <grub/util/ofpath.h>
 #include <grub/hfsplus.h>
+#include <grub/time.h>
 
 #include <string.h>
 
@@ -2033,6 +2034,24 @@ main (int argc, char *argv[])
       break;
     }
 
+  {
+    const char *journaled_fs[] = {"xfs", "ext2", NULL};
+    int i;
+
+    for (i = 0; journaled_fs[i]; ++i)
+      if (grub_strcmp (grub_fs->name, journaled_fs[i]) == 0)
+	{
+	  int retries = 10;
+
+	  /* If the fs is already frozen at that point, we could generally
+	   * expected that it will be soon unfrozen again (assuming some other
+	   * process has frozen it for snapshotting or something), so we may
+	   * as well retry a few (limited) times in a delay loop. */
+	  while (retries-- && !grub_install_sync_fs_journal (grubdir))
+	    grub_sleep (1);
+	  break;
+	}
+  }
   /*
    * Either there are no platform specific code, or it didn't raise
    * ponr. Raise it here, because usually this is already past point
diff --git a/util/grub-mkconfig.in b/util/grub-mkconfig.in
index b450aff60..22b04d2cc 100644
--- a/util/grub-mkconfig.in
+++ b/util/grub-mkconfig.in
@@ -335,6 +335,15 @@ for i in "${grub_mkconfig_dir}"/* ; do
   esac
 done
 
+sync_fs_journal () {
+  if test "x$GRUB_DEVICE" = "x$GRUB_DEVICE_BOOT" &&
+     test "x$GRUB_FS" = "xxfs" -o "x$GRUB_FS" = "xext2" &&
+     test "x${grub_cfg}" != "x" -a "x`make_system_path_relative_to_its_root $grub_cfg`" = "x/boot/grub2/grub.cfg" &&
+     test -x /usr/sbin/fsfreeze; then
+    /usr/sbin/fsfreeze --freeze / && /usr/sbin/fsfreeze --unfreeze /
+  fi
+} >&2
+
 if test "x${grub_cfg}" != "x" ; then
   if ! ${grub_script_check} ${grub_cfg}.new; then
     # TRANSLATORS: %s is replaced by filename
@@ -351,6 +360,7 @@ and /etc/grub.d/* files or please file a bug report with
     cat ${grub_cfg}.new > ${grub_cfg}
     umask $oldumask
     rm -f ${grub_cfg}.new
+    sync_fs_journal || true
   fi
 fi
 
-- 
2.41.0