On Mon, Feb 03, 2014 at 02:29:43AM -0800, Christoph Hellwig wrote: > On Thu, Jan 30, 2014 at 02:01:38PM -0800, Linus Torvalds wrote: > > In the end, all the original call-sites should have a dentry, and none > > of this is "fundamental". But you're right, it looks like an absolute > > nightmare to add the dentry pointer through the whole chain. Damn. > > > > So I'm not thrilled about it, but maybe that "d_find_alias(inode)" to > > find the dentry is good enough in practice. It feels very much > > incorrect (it could find a dentry with a path that you cannot actually > > access on the server, and result in user-visible errors), but I > > definitely see your argument. It may just not be worth the pain for > > this odd ceph case. > > It's not just ceph. 9p fundamentally needs it and I really want to > convert 9p to the new code so that we can get rid of the lower level > interfaces entirely and eventually move ACL dispatching entirely > into the VFS. The same d_find_alias hack should work for 9p as well, > although spreading this even more gets uglier and uglier. Similarly > for CIFS which pretends to understand the Posix ACL xattrs, but doesn't > use any of the infrastructure as it seems to rely on server side > enforcement. 9P is going to be fun to deal with; that's why I've ended up abandoning vfs.git#experimental-xattr last year. We probably want to move FIDs from dentries to inodes there, and rely in ->getxattr() et.al. upon having already done ->d_revalidate() on some dentry for that inode. Another pile of fun is fsnotify_xattr() call in __vfs_setxattr_noperm() and the whole misbegotten IMA/EVM mess ;-/ See #experimental-xattr - a lot of stuff in that direction is sitting there; might turn out to be useful. -- 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
