On Fri, Jul 09, 2021 at 04:10:16PM -0400, Bruce Fields wrote: > On Fri, Jul 9, 2021 at 1:59 PM Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: > > nfs seems to have some issues. > > I'm not sure what the expected behavior is for nfs. All I have for > now is some generic troubleshooting ideas, sorry: > > > - I can set user.foo xattr on symlink and query it back using xattr name. > > > > getfattr -h -n user.foo foo-link.txt > > > > But when I try to dump all xattrs on this file, user.foo is being > > filtered out it looks like. Not sure why. > > Logging into the server and seeing what's set there could help confirm > whether it's the client or server that's at fault. (Or watching the > traffic in wireshark; there are GET/SET/LISTXATTR ops that should be > easy to spot.) > > > - I can't set "user.foo" xattr on a device node on nfs and I get > > "Permission denied". I am assuming nfs server is returning this. > > Wireshark should tell you whether it's the server or client doing that. > > The RFC is https://datatracker.ietf.org/doc/html/rfc8276, and I don't > see any explicit statement about what the server should do in the case > of symlinks or device nodes, but I do see "Any regular file or > directory may have a set of extended attributes", so that was clearly > the assumption. Also, NFS4ERR_WRONG_TYPE is listed as a possible > error return for the xattr ops. But on a quick skim I don't see any > explicit checks in the nfsd code, so I *think* it's just relying on > the vfs for any file type checks. Hi Bruce, Thanks for the response. I am just trying to do set a user.foo xattr on a device node on nfs. setfattr -n "user.foo" -v "bar" /mnt/nfs/test-dev and I get -EACCESS. I put some printk() statements and EACCESS is being returned from here. nfs4_xattr_set_nfs4_user() { if (!nfs_access_get_cached(inode, current_cred(), &cache, true)) { if (!(cache.mask & NFS_ACCESS_XAWRITE)) { return -EACCES; } } } Value of cache.mask=0xd at the time of error. Thanks Vivek
