As mmp and check_mmp is point to the same data, so there will never detect conflict. To solve this issue just compare to local data. Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx> --- fs/ext4/mmp.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c index 89797f12a815..0fe7b9ac9db6 100644 --- a/fs/ext4/mmp.c +++ b/fs/ext4/mmp.c @@ -154,6 +154,7 @@ static int kmmpd(void *data) unsigned long last_update_time; unsigned long last_check_time; unsigned long diff; + char nodename[64]; int retval = 0; mmp_block = le64_to_cpu(es->s_mmp_block); @@ -169,8 +170,8 @@ static int kmmpd(void *data) BUILD_BUG_ON(sizeof(mmp->mmp_bdevname) < BDEVNAME_SIZE); bdevname(bh->b_bdev, mmp->mmp_bdevname); - memcpy(mmp->mmp_nodename, init_utsname()->nodename, - sizeof(mmp->mmp_nodename)); + memcpy(nodename, init_utsname()->nodename, sizeof(nodename)); + memcpy(mmp->mmp_nodename, nodename, sizeof(mmp->mmp_nodename)); last_update_time = jiffies; while (!kthread_should_stop() && !sb_rdonly(sb)) { @@ -224,8 +225,8 @@ static int kmmpd(void *data) } mmp_check = (struct mmp_struct *)(bh_check->b_data); - if (mmp->mmp_seq != mmp_check->mmp_seq || - memcmp(mmp->mmp_nodename, mmp_check->mmp_nodename, + if (seq != mmp_check->mmp_seq || + memcmp(nodename, mmp_check->mmp_nodename, sizeof(mmp->mmp_nodename))) { dump_mmp_msg(sb, mmp_check, "Error while updating MMP info. " -- 2.31.1