Block layer discard requests
Posted Aug 15, 2008 23:09 UTC (Fri) by giraffedata
Parent article: Block layer discard requests
there is a new ioctl() call (BLKDISCARD) which creates a discard request.
This is the oft-discussed file punch/clear/freespace system call -- on a block device special file. Why doesn't linux have this yet? Other OSes do. This new ioctl class seems to be actively avoiding it.
Needless to say, applications using this feature should be rare and very carefully written.
No, I don't see it. These would be approximately the same applications that write to block device special files today and their use of the discard ioctl would be no more careful than their use of write().
to post comments)