Hello! > You mean POSIX compliance is impossible? So what? It is possible to > implement an approximation that is _at least_ as good as samefile(). > One really dumb way is to set st_ino to the 'struct inode' pointer for > example. That will sure as hell fit into 64bits and will give a > unique (alas not stable) identifier for each file. Opening two files, > doing fstat() on them and comparing st_ino will give exactly the same > guarantees as samefile(). Good, ... except that it doesn't work. AFAIK, POSIX mandates inodes to be unique until umount, not until inode cache expires :-) IOW, if you have such implementation of st_ino, you can emulate samefile() with it, but you cannot have it without violating POSIX. > 4 billion files, each with more than one link is pretty far fetched. Not on terabyte scale disk arrays, which are getting quite common these days. > And anyway, filesystems can take steps to prevent collisions, as they > do currently for 32bit st_ino, without serious difficulties > apparently. They currently do that usually by not supporting more than 4G files in a single FS. Have a nice fortnight -- Martin `MJ' Mares <mj@xxxxxx> http://mj.ucw.cz/ Faculty of Math and Physics, Charles University, Prague, Czech Rep., Earth "Oh no, not again!" -- The bowl of petunias - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
