On Tue, 23 Jun 2009, David Howells wrote: > Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > > > Define O_NOACC as 3. On open(..., O_FILESYSTEM | O_NOACC) require no > > privileges on the file. > > It must also work with O_NOFOLLOW, which I think your suggestion will. This does sound like a fairly natural extension of what we already do. We essentially already have O_NOACCESS (3), and use it exactly because we need to do operations on a file descriptor without "real" accesses (notably things like accessing /dev/cdrom without waiting/checking for the disk being present etc). O_FILESYSTEM I don't like as a name (to me, it doesn't say _what_ it is doing - of course an open works on a filesystem!), but the concept of saying "don't follow device nodes - just open the node itself" makes perfect sense. Together with O_NOFOLLOW it also fairly naturally means "give me the actual symlink _node_, don't return error or follow it". And we can trivially test at a higher level that O_FILESYSTEM (with a better name, please), is always paired with O_NOACCESS (not O_NOACC: we do not try to save three letters, there is no shortage). Because the raw node obviously must never really be "accessed" (ie you can't do read/write etc on it). That said, I do _not_ like the notion of > Add a new inode->i_filesystem_fop pointer regardless of whether it's in inode->i_op or wherever. I think we should just handle this in the regular "inode->f_op->open" routine, the same way we handle FMODE_EXCLUSIVE (O_EXCL), FMODE_NDELAY (O_NONBLOCK) and lack of access rights (O_NOACCESS) in the driver open routines that currently handle those specially (O_NDELAY is spe Al? Linus -- 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
