[email protected] (Greg Troxel) writes: >I am somewhat surprised that ccd uses the block device but that's what >the man page says.
Almost everything in the kernel uses the block device as the char device (or rather the physio() function used by it) supports I/O only from userland. An exception is the wedge discovery mechanism. Since there can be only a single opener of a block device, it needs to work around this by: - opening the char device. - determining the corresponding block device. - calling the block device strategy routine for I/O. - closing the char device again. The device handling and arbitrating mechanisms are pretty arcane.
