Update and questions.

[Andrew W Elble <aweits@rit.edu>]

I've been busy patching in things to observe what's going on with my
delegation issues.

I implemented a seq_file interface on the server to walk the
file_hashtbl, and some interesting things have popped up:

This is a nfs4_file that has two open stateids allocated to the same client:

file fh: 82369f70 R:2 F:4 FP:ffff881f24286b58 I:ffff881f6f6a91d0 D:ffff881febf08b40 /home/<stuff>
  Deleg: Linux NFSv4.1 <hosta> : 2292335602000000d89e0700 120317
  Deleg: Linux NFSv4.1 <hostb> : 2292335607000000437f0700 148262
  Stateid: Linux NFSv4.1 <hosta> : 2292335602000000d69e0700/1
  Stateid: Linux NFSv4.1 <hosta> : 2292335602000000d79e0700/1

This one has four:

file fh: 6ecdd5f8 R:4 F:4 FP:ffff88083e2974a0 I:ffff881f6c9349d0 D:ffff883f4ad1e780 /home/<stuff>
  Stateid: Linux NFSv4.1 <hosta> : 2292335602000000f1620800/1
  Stateid: Linux NFSv4.1 <hosta> : 2292335602000000f0620800/1
  Stateid: Linux NFSv4.1 <hosta> : 2292335602000000c64c0800/1
  Stateid: Linux NFSv4.1 <hosta> : 2292335602000000c74c0800/1

These are nfs4_files that have elevated fi_ref counts but are
essentially "empty":
(note: fi_had_conflict is seemingly always nonzero on entries like these)

file fh: ee23414c F:1 FP:ffff88087fc52318 I:0000000000000000
file fh: 5a8e8c86 F:2 FP:ffff881f5e872318 I:0000000000000000

======================

for clarity:

+static int nfs4_file_hash_list_show(struct seq_file *seq, void *v)
+{
+       char *name = __getname();
+       char *p;
+       int i;
+       struct dentry *dentry;
+       struct inode *inode = NULL;
+       struct nfs4_delegation *dp;
+       struct nfs4_ol_stateid *stp;
+       if (!name)
+               goto out;
+
+       if (v != SEQ_START_TOKEN) {
+               struct nfs4_file *fp = (struct nfs4_file *) v;
+               spin_lock(&fp->fi_lock);
+               seq_printf(seq, "file fh: %08x",nfsd_fhandle_hash(&fp->fi_fhandle));
+               for (i = 0; i < 3; i++) {
+                       if (fp->fi_fds[i]) {
+                               if (!inode)
+                                       inode = (fp->fi_fds[i])->f_inode;
+                               dentry = (fp->fi_fds[i])->f_path.dentry;
+                               if (dentry)
+                                       break;
+                       }
+               }
+               if (atomic_read(&fp->fi_access[O_RDONLY]) > 0)
+                       seq_printf(seq, " R:%d",
+                               atomic_read(&fp->fi_access[O_RDONLY]));
+               if (atomic_read(&fp->fi_access[O_WRONLY]) > 0)
+                       seq_printf(seq, " W:%d",
+                               atomic_read(&fp->fi_access[O_WRONLY]));
+               seq_printf(seq, " F:%d",
+                       atomic_read(&fp->fi_ref));
+               seq_printf(seq, " FP:%pK", fp);
+               if ((!dentry) && fp->fi_deleg_file)
+                       dentry = fp->fi_deleg_file->f_path.dentry;
+               if ((!inode) && fp->fi_deleg_file)
+                       inode = (fp->fi_deleg_file)->f_inode;
+               seq_printf(seq, " I:%pK", inode);
+               if (dentry) {
+                       p = dentry_path_raw(dentry, name, PATH_MAX);
+                       seq_printf(seq, " D:%pK %s\n", dentry, p);
+               } else {
+                       seq_printf(seq, "\n");
+               }
+               list_for_each_entry(dp, &fp->fi_delegations, dl_perfile) {
+                       seq_printf(seq, "  Deleg: %.*s : %*phN %lu\n",
+                               (int)dp->dl_recall.cb_clp->cl_name.len,
+                               dp->dl_recall.cb_clp->cl_name.data,
+                               12,
+                               &dp->dl_stid.sc_stateid.si_opaque,
+                               get_seconds() - dp->dl_alloctime);
+               }
+               list_for_each_entry(stp, &fp->fi_stateids, st_perfile) {
+                       seq_printf(seq, "  Stateid: %.*s : %*phN/%x\n",
+                               (int)stp->st_stid.sc_client->cl_name.len,
+                               stp->st_stid.sc_client->cl_name.data,
+                               12,
+                               &stp->st_stid.sc_stateid.si_opaque,
+                               stp->st_stid.sc_stateid.si_generation);
+               }
+               spin_unlock(&fp->fi_lock);
+       }
+       __putname(name);
+out:
+       return 0;
+}

Thanks,

Andy

-- 
Andrew W. Elble
aweits@discipline.rit.edu
Infrastructure Engineer, Communications Technical Lead
Rochester Institute of Technology
PGP: BFAD 8461 4CCF DC95 DA2C B0EB 965B 082E 863E C912