On Tue 19-10-21 14:49:55, Ye Bin wrote: > If two host have the same nodename, and seq start from 0, May cause the > detection mechanism to fail. > So init 'seq' with the value which set in 'ext4_multi_mount_protect' to > accelerate conflict detection. > > Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx> ... > @@ -143,6 +143,7 @@ static int kmmpd(void *data) > mmp_block = le64_to_cpu(es->s_mmp_block); > mmp = (struct mmp_struct *)(bh->b_data); > mmp->mmp_time = cpu_to_le64(ktime_get_real_seconds()); > + seq = le32_to_cpu(mmp->mmp_seq); > /* > * Start with the higher mmp_check_interval and reduce it if > * the MMP block is being updated on time. Thanks for the patch. After discussing what MMP guards against and what it does not protect, I don't think this change is actually needed. Under normal conditions we expect kmmpd() to only write to MMP block, checking of MMP block is done only in ext4_multi_mount_protect(). And for checking there to trigger, using 'seq' starting from 1 in kmmpd is enough... Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
