Hello! On Tue 30-06-20 11:34:49, Costa Sapuntzakis wrote: > > Yes, probably ext4_superblock_csum_set() should use > > > > lock_buffer(EXT4_SB(sb)->s_sbh) > > > > to synchronize updating of superblock checksum. Will you send a patch? > > Yes. I will send a patch. Thanks! > I noticed lock_buffer can sleep. That would seem to imply to me that > lock_buffer can be held across I/Os. > I worry that this will occasionally significantly slow down this code > path compared to what it used to be. Are there any things > about the way ext4 uses buffers that makes this less of a concern? Yes, buffer lock is a sleeping lock but that's the lock we usually use to protect consistency of buffer contents. So I prefer to use that lock unless we have definitive performance data showing we need something more clever... Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
