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commit 7fd5feff97c4b1f446f8fcf6d37aca0c64e7c763
Author: Javier Martinez Canillas <javierm@redhat.com>
Date:   Fri Jun 11 21:36:16 2021 +0200

    fs/ext2: Ignore checksum seed incompat feature
    
    This incompat feature is used to denote that the filesystem stored its
    metadata checksum seed in the superblock. This is used to allow tune2fs
    changing the UUID on a mounted metdata_csum filesystem without having
    to rewrite all the disk metadata. However, the GRUB doesn't use the
    metadata checksum at all. So, it can just ignore this feature if it
    is enabled. This is consistent with the GRUB filesystem code in general
    which just does a best effort to access the filesystem's data.
    
    The checksum seed incompat feature has to be removed from the ignore
    list if the support for metadata checksum verification is added to the
    GRUB ext2 driver later.
    
    Suggested-by: Eric Sandeen <esandeen@redhat.com>
    Suggested-by: Lukas Czerner <lczerner@redhat.com>
    Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
    Reviewed-by: Lukas Czerner <lczerner@redhat.com>
    Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

diff --git a/grub-core/fs/ext2.c b/grub-core/fs/ext2.c
index e7dd78e66..4953a1591 100644
--- a/grub-core/fs/ext2.c
+++ b/grub-core/fs/ext2.c
@@ -103,6 +103,7 @@ GRUB_MOD_LICENSE ("GPLv3+");
 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
 #define EXT4_FEATURE_INCOMPAT_MMP		0x0100
 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
+#define EXT4_FEATURE_INCOMPAT_CSUM_SEED		0x2000
 #define EXT4_FEATURE_INCOMPAT_ENCRYPT          0x10000
 
 /* The set of back-incompatible features this driver DOES support. Add (OR)
@@ -123,10 +124,15 @@ GRUB_MOD_LICENSE ("GPLv3+");
  * mmp:            Not really back-incompatible - was added as such to
  *                 avoid multiple read-write mounts. Safe to ignore for this
  *                 RO driver.
+ * checksum seed:  Not really back-incompatible - was added to allow tools
+ *                 such as tune2fs to change the UUID on a mounted metadata
+ *                 checksummed filesystem. Safe to ignore for now since the
+ *                 driver doesn't support checksum verification. However, it
+ *                 has to be removed from this list if the support is added later.
  */
 #define EXT2_DRIVER_IGNORED_INCOMPAT ( EXT3_FEATURE_INCOMPAT_RECOVER \
-				     | EXT4_FEATURE_INCOMPAT_MMP)
-
+				     | EXT4_FEATURE_INCOMPAT_MMP \
+				     | EXT4_FEATURE_INCOMPAT_CSUM_SEED)
 
 #define EXT3_JOURNAL_MAGIC_NUMBER	0xc03b3998U