On Thu, Oct 17, 2019 at 08:29:11AM -0400, Theodore Y. Ts'o wrote: > > + /* > > + * Writes that span EOF might trigger an IO size update on completion, > > + * so consider them to be dirty for the purposes of O_DSYNC even if > > + * there is no other metadata changes being made or are pending here. > > + */ > > iomap->flags = 0; > > - if (ext4_inode_datasync_dirty(inode)) > > + if (ext4_inode_datasync_dirty(inode) || > > + offset + length > i_size_read(inode)) > > iomap->flags |= IOMAP_F_DIRTY; > > + > > iomap->bdev = inode->i_sb->s_bdev; > > iomap->dax_dev = sbi->s_daxdev; > > iomap->offset = (u64)first_block << blkbits; > > Ext4 is not currently using iomap for any kind of writing right now, > so perhaps this should land via Matthew's patchset? It does for DAX, which is one of the consumers of IOMAP_F_DIRTY.