@@ -2332,8 +2332,8 @@ extern int ext4_register_li_request(struct super_block *sb,
static inline int ext4_has_group_desc_csum(struct super_block *sb)
{
return EXT4_HAS_RO_COMPAT_FEATURE(sb,
- EXT4_FEATURE_RO_COMPAT_GDT_CSUM |
- EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM) ||
+ (EXT4_SB(sb)->s_chksum_driver != NULL);
}
static inline int ext4_has_metadata_csum(struct super_block *sb)
@@ -2025,6 +2025,10 @@ static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
}
/* old crc16 code */
+ if (!(sbi->s_es->s_feature_ro_compat &
+ cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
+ return 0;
+
offset = offsetof(struct ext4_group_desc, bg_checksum);
crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
This is a note to let you know that I have just added a patch titled ext4: check s_chksum_driver when looking for bg csum presence to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt1. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From c6243bdb2f0a6a1767e52a6d127f4441ba6b8503 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" <darrick.wong@oracle.com> Date: Tue, 14 Oct 2014 02:35:49 -0400 Subject: ext4: check s_chksum_driver when looking for bg csum presence commit 813d32f91333e4c33d5a19b67167c4bae42dae75 upstream. Convert the ext4_has_group_desc_csum predicate to look for a checksum driver instead of the metadata_csum flag and change the bg checksum calculation function to look for GDT_CSUM before taking the crc16 path. Without this patch, if we mount with ^uninit_bg,^metadata_csum and later metadata_csum gets turned on by accident, the block group checksum functions will incorrectly assume that checksumming is enabled (metadata_csum) but that crc16 should be used (!s_chksum_driver). This is totally wrong, so fix the predicate and the checksum formula selection. (Granted, if the metadata_csum feature bit gets enabled on a live FS then something underhanded is going on, but we could at least avoid writing garbage into the on-disk fields.) Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- fs/ext4/ext4.h | 4 ++-- fs/ext4/super.c | 4 ++++ 2 files changed, 6 insertions(+), 2 deletions(-) -- 2.1.0