On 2/21/2017 16:52, houlinfei wrote: > > hi everyone: > I met a problem about subdirectory permission when client mount this subdirectory using nfs4. For example: > the contents of the /etc/exports file is > /root/hh *(ro,sync,insecure,no_subtree_check) > /root/hh/hh1 *(rw,sync,insecure,no_subtree_check) > and the two directory permission is 777. And the parent directory's export permission is read-only, the subdirectory's export permission is read-write. > Then client mount /root/hh/hh1 on /mnt/yy using nfs4. But the /mnt/yy directory only can read.If client mount /root/hh/hh1 on /mnt/yy using nfs3, the /mnt/yy can write. nfs3 gets the filehandle of /root/hh/hh1 from rpc.mountd before really mounting, so that, nfs3 do the later process with the filehandle of /root/hh/hh1, with the second exports entry. But, nfs4 get the filehandle by LOOKUP through nfsd step by step, at first, LOOKUP "/" as the pseudo filesystem with an pseudo exports entry, second, LOOKUP "/root/" also use the pseudo export entry, next, LOOKUP "/root/hh/" will get a new export entry for "/root/" use a pseudo export entry, but at last LOOKUP "/root/hh/hh1", nfsd uses the export entry for "/root/hh/" that isn't a pseudo entry entry. So that, nfsv3 client can write the directory, but nfsv4 client can't. > Who know how to solve this problem about nfs4? Thanks very much~ Without change any codes of rpc.mountd and nfsd, there is a hacker method for it. # chmod -x /root/hh/hh1 # chmod +t /root/hh/hh1 # setfattr -n "trusted.junction.nfs" -v "anything" /root/hh/hh1 Umount the nfs and remount as nfsv4. Cc Bruce, Neil, Steve, Is it needed adding an xattr as "junction.nfs" for fixing this problem? thanks, Kinglong Mee -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
