On Fri, 2007-10-26 at 22:24 +0200, Andreas Gruenbacher wrote: > On Friday 26 October 2007 13:30, Miklos Szeredi wrote: > > There's a slight problem (other than HCH not liking it) with this > > approach of passing the open file in iattr: for special files, the > > struct file pointer makes no sense to the filesystem, since it is always > > opened by the generic functions. > > So what do you think where the inodes come from for syscalls like fchmod? Out > of struct file, of course. But your f_op->getattr and f_op->setattr patches > are meant for passing struct file down to filesystems anyway, so that > completely contradicts what you are saying above.
For special files, f_op->fsetattr will be NULL, since init_special_inode() will set up i_fop that way. So the filesystem's fsetattr() will only be called for regular files and/or directories, depending on how it sets up i_fop. With the ia_file thing, the filesystem would receive the struct file pointer in all cases. So the posted patch would break AFS and FUSE, because they unconditionally use ia_file if available and don't check the file type. They could check the file type, but still the interface would be ugly. > > So I think the correct solution (which was suggested by Trond and > > others) is to define an f_op->fsetattr() method, which interested > > filesystems can define. > > That's nothing but a replacement for ATTR_FILE and iattr->ia_file. Except by > removing the ATTR_FILE flag, LSMs will no longer get that information for > distinguishing file descriptor operations from other operations. > > AppArmor needs to know when notify_change is called on a file descriptor, but > it doesn't care about the file descriptor itself. So any way of passing along > that information will be fine. Ah, so if we kept ATTR_FILE and got rid of iattr_file, would that be OK for AppArmor? Thanks, Miklos - 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/
