From 5537a586e0b92b94910d0170a128ae8a85787713 Mon Sep 17 00:00:00 2001
From: Vladimir Serbinenko <phcoder@gmail.com>
Date: Mon, 16 Feb 2015 21:08:37 +0100
Subject: [PATCH 294/506] ext2: Ignore INCOMPAT_MMP.
It's not really incompatible as long as driver never writes to FS.
---
grub-core/fs/ext2.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/grub-core/fs/ext2.c b/grub-core/fs/ext2.c
index 4d45edc..5199cb0 100644
--- a/grub-core/fs/ext2.c
+++ b/grub-core/fs/ext2.c
@@ -100,6 +100,7 @@ GRUB_MOD_LICENSE ("GPLv3+");
#define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
#define EXT4_FEATURE_INCOMPAT_EXTENTS 0x0040 /* Extents used */
#define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
+#define EXT4_FEATURE_INCOMPAT_MMP 0x0100
#define EXT4_FEATURE_INCOMPAT_FLEX_BG 0x0200
/* The set of back-incompatible features this driver DOES support. Add (OR)
@@ -115,8 +116,13 @@ GRUB_MOD_LICENSE ("GPLv3+");
* journal because they will ignore the journal, but the next
* ext3 driver to mount the volume will find the journal and
* replay it, potentially corrupting the metadata written by
- * the ext2 drivers. Safe to ignore for this RO driver. */
-#define EXT2_DRIVER_IGNORED_INCOMPAT ( EXT3_FEATURE_INCOMPAT_RECOVER )
+ * the ext2 drivers. Safe to ignore for this RO driver.
+ * mmp: Not really back-incompatible - was added as such to
+ * avoid multiple read-write mounts. Safe to ignore for this
+ * RO driver.
+ */
+#define EXT2_DRIVER_IGNORED_INCOMPAT ( EXT3_FEATURE_INCOMPAT_RECOVER \
+ | EXT4_FEATURE_INCOMPAT_MMP)
#define EXT3_JOURNAL_MAGIC_NUMBER 0xc03b3998U
--
2.4.3