On Sun, Feb 15, 2015 at 9:46 PM, NeilBrown <neilb@xxxxxxx> wrote: > On Sat, 14 Feb 2015 13:17:00 +0000 Nix <nix@xxxxxxxxxxxxx> wrote: > >> On 10 Feb 2015, J. Bruce Fields outgrape: >> >> > It might be interesting to see output from >> > >> > rpc.debug -m rpc -s cache >> > cat /proc/net/rpc/nfsd.export/content >> > cat /proc/net/rpc/nfsd.fh/content >> > >> > especially after the problem manifests. >> >> So the mount has vanished again. I couldn't make it happen with >> nordirplus in the mount options, so that might provide you with a clue. > > Yup. It does. > > There is definitely something wrong in nfs_prime_dcache. I cannot quite > trace through from cause to effect, but maybe I don't need to. > > Can you try the following patch and see if that makes the problem disappear? > > When you perform a READDIRPLUS request on a directory that contains > mountpoints, the the Linux NFS server doesn't return a file-handle for > those names which are mountpoints (because doing so is a bit tricky). > > nfs3_decode_dirent notices and decodes as a filehandle with zero length. > > The "nfs_same_file()" check in nfs_prime_dcache() determines that isn't > the same as the filehandle it has, and tries to invalidate it and make a new > one. > > The invalidation should fail (probably does). > The creating of a new one ... might succeed. Beyond that, it all gets a bit > hazy. > > Anyway, please try: > > diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c > index 9b0c55cb2a2e..a460669dc395 100644 > --- a/fs/nfs/dir.c > +++ b/fs/nfs/dir.c > @@ -541,7 +541,7 @@ int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *en > > count++; > > - if (desc->plus != 0) > + if (desc->plus != 0 && entry->fh.size) > nfs_prime_dcache(desc->file->f_path.dentry, entry); > > status = nfs_readdir_add_to_array(entry, page); > > > which you might have to apply by hand. Doesn't that check ultimately belong in nfs_fget()? It would seem to apply to all filehandles, irrespective of provenance. Cheers Trond -- Trond Myklebust Linux NFS client maintainer, PrimaryData trond.myklebust@xxxxxxxxxxxxxxx -- 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
