Add statistics to /proc/fs/afs/stats for data transfer RPC operations.  New
lines are added that look like:
	file-rd : n=55794 nb=
10252282150
	file-wr : n=9789 nb=
3247763645
where n= indicates the number of ops completed and nb= indicates the number
of bytes successfully transferred.  file-rd is the counts for read/fetch
operations and file-wr the counts for write/store operations.
Note that directory and symlink downloading are included in the file-rd
stats at the moment.
Signed-off-by: David Howells <dhowells@redhat.com>
 
                ret = afs_end_vnode_operation(&fc);
        }
 
+       if (ret == 0) {
+               afs_stat_v(vnode, n_fetches);
+               atomic_long_add(desc->actual_len,
+                               &afs_v2net(vnode)->n_fetch_bytes);
+       }
+
        _leave(" = %d", ret);
        return ret;
 }
 
        atomic_t                n_read_dir;     /* Number of directory pages read */
        atomic_t                n_dir_cr;       /* Number of directory entry creation edits */
        atomic_t                n_dir_rm;       /* Number of directory entry removal edits */
+       atomic_t                n_stores;       /* Number of store ops */
+       atomic_long_t           n_store_bytes;  /* Number of bytes stored */
+       atomic_long_t           n_fetch_bytes;  /* Number of bytes fetched */
+       atomic_t                n_fetches;      /* Number of data fetch ops */
 };
 
 extern const char afs_init_sysname[];
 
        seq_printf(m, "dir-edit: cr=%u rm=%u\n",
                   atomic_read(&net->n_dir_cr),
                   atomic_read(&net->n_dir_rm));
+
+       seq_printf(m, "file-rd : n=%u nb=%lu\n",
+                  atomic_read(&net->n_fetches),
+                  atomic_long_read(&net->n_fetch_bytes));
+       seq_printf(m, "file-wr : n=%u nb=%lu\n",
+                  atomic_read(&net->n_stores),
+                  atomic_long_read(&net->n_store_bytes));
        return 0;
 }
 
 
        }
 
        switch (ret) {
+       case 0:
+               afs_stat_v(vnode, n_stores);
+               atomic_long_add((last * PAGE_SIZE + to) -
+                               (first * PAGE_SIZE + offset),
+                               &afs_v2net(vnode)->n_store_bytes);
+               break;
        case -EACCES:
        case -EPERM:
        case -ENOKEY: