Jörn Engel wrote: >Question came up before, albeit with a different phrasing. One >possible approach to benefit from this ability would be to create a >"forget" operation. When a filesystem already knows that some data is >unneeded (after a truncate or erase operation), it will ask the device >to forget previously occupied blocks. > >The device then has the _option_ of handling the forget operation. >Further reads on these blocks may return random data. > >And since noone stepped up to implement this yet, you can still get >all the fame and glory yourself! ;) > >
I'm not sure we're talking about the same thing. I'm not suggesting new features in the VFS layer. I want to know if something breaks if I implement this erase feature in the MMC layer. In essence the file system has marked the sectors as "forget" by issuing a write to them. The question is if it is assumed that they are unchanged if the write fails half-way through. I'd have to say that this is a dangerous assumption to make already today since some systems might not be able to tell where it fails if a large chunk of data is given to it, perhaps because of a deep pipeline before it actually reaches the physical storage. Rgds Pierre - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
