+static int
+ptlrpc_lprocfs_read_req_history_len(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ struct ptlrpc_service *svc = data;
+
+ *eof = 1;
+ return snprintf(page, count, "%d\n", svc->srv_n_history_rqbds);
+}
+
+static int
+ptlrpc_lprocfs_read_req_history_max(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ struct ptlrpc_service *svc = data;
+
+ *eof = 1;
+ return snprintf(page, count, "%d\n", svc->srv_max_history_rqbds);
+}
+
+static int
+ptlrpc_lprocfs_write_req_history_max(struct file *file, const char *buffer,
+ unsigned long count, void *data)
+{
+ struct ptlrpc_service *svc = data;
+ int bufpages;
+ int val;
+ int rc = lprocfs_write_helper(buffer, count, &val);
+
+ if (rc < 0)
+ return rc;
+
+ if (val < 0)
+ return -ERANGE;
+
+ /* This sanity check is more of an insanity check; we can still
+ * hose a kernel by allowing the request history to grow too
+ * far. */
+ bufpages = (svc->srv_buf_size + CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT;
+ if (val > num_physpages/(2 * bufpages))
+ return -ERANGE;
+
+ spin_lock(&svc->srv_lock);
+ svc->srv_max_history_rqbds = val;
+ spin_unlock(&svc->srv_lock);
+
+ return count;
+}
+
+struct ptlrpc_srh_iterator {
+ __u64 srhi_seq;
+ struct ptlrpc_request *srhi_req;
+};
+
+int
+ptlrpc_lprocfs_svc_req_history_seek(struct ptlrpc_service *svc,
+ struct ptlrpc_srh_iterator *srhi,
+ __u64 seq)
+{
+ struct list_head *e;
+ struct ptlrpc_request *req;
+
+ if (srhi->srhi_req != NULL &&
+ srhi->srhi_seq > svc->srv_request_max_cull_seq &&
+ srhi->srhi_seq <= seq) {
+ /* If srhi_req was set previously, hasn't been culled and
+ * we're searching for a seq on or after it (i.e. more
+ * recent), search from it onwards.
+ * Since the service history is LRU (i.e. culled reqs will
+ * be near the head), we shouldn't have to do long
+ * re-scans */
+ LASSERT (srhi->srhi_seq == srhi->srhi_req->rq_history_seq);
+ LASSERT (!list_empty(&svc->srv_request_history));
+ e = &srhi->srhi_req->rq_history_list;
+ } else {
+ /* search from start */
+ e = svc->srv_request_history.next;
+ }
+
+ while (e != &svc->srv_request_history) {
+ req = list_entry(e, struct ptlrpc_request, rq_history_list);
+
+ if (req->rq_history_seq >= seq) {
+ srhi->srhi_seq = req->rq_history_seq;
+ srhi->srhi_req = req;
+ return 0;
+ }
+ e = e->next;
+ }
+
+ return -ENOENT;
+}
+
+static void *
+ptlrpc_lprocfs_svc_req_history_start(struct seq_file *s, loff_t *pos)
+{
+ struct ptlrpc_service *svc = s->private;
+ struct ptlrpc_srh_iterator *srhi;
+ int rc;
+
+ OBD_ALLOC(srhi, sizeof(*srhi));
+ if (srhi == NULL)
+ return NULL;
+
+ srhi->srhi_seq = 0;
+ srhi->srhi_req = NULL;
+
+ spin_lock(&svc->srv_lock);
+ rc = ptlrpc_lprocfs_svc_req_history_seek(svc, srhi, *pos);
+ spin_unlock(&svc->srv_lock);
+
+ if (rc == 0) {
+ *pos = srhi->srhi_seq;
+ return srhi;
+ }
+
+ OBD_FREE(srhi, sizeof(*srhi));
+ return NULL;
+}
+
+static void
+ptlrpc_lprocfs_svc_req_history_stop(struct seq_file *s, void *iter)
+{
+ struct ptlrpc_srh_iterator *srhi = iter;
+
+ if (srhi != NULL)
+ OBD_FREE(srhi, sizeof(*srhi));
+}
+
+static void *
+ptlrpc_lprocfs_svc_req_history_next(struct seq_file *s,
+ void *iter, loff_t *pos)
+{
+ struct ptlrpc_service *svc = s->private;
+ struct ptlrpc_srh_iterator *srhi = iter;
+ int rc;
+
+ spin_lock(&svc->srv_lock);
+ rc = ptlrpc_lprocfs_svc_req_history_seek(svc, srhi, *pos + 1);
+ spin_unlock(&svc->srv_lock);
+
+ if (rc != 0) {
+ OBD_FREE(srhi, sizeof(*srhi));
+ return NULL;
+ }
+
+ *pos = srhi->srhi_seq;
+ return srhi;
+}
+
+static int ptlrpc_lprocfs_svc_req_history_show(struct seq_file *s, void *iter)
+{
+ struct ptlrpc_service *svc = s->private;
+ struct ptlrpc_srh_iterator *srhi = iter;
+ struct ptlrpc_request *req;
+ int rc;
+
+ spin_lock(&svc->srv_lock);
+
+ rc = ptlrpc_lprocfs_svc_req_history_seek(svc, srhi, srhi->srhi_seq);
+
+ if (rc == 0) {
+ req = srhi->srhi_req;
+
+ /* Print common req fields.
+ * CAVEAT EMPTOR: we're racing with the service handler
+ * here. The request could contain any old crap, so you
+ * must be just as careful as the service's request
+ * parser. Currently I only print stuff here I know is OK
+ * to look at coz it was set up in request_in_callback()!!! */
+ seq_printf(s, LPD64":%s:%s:"LPD64":%d:%s ",
+ req->rq_history_seq, libcfs_nid2str(req->rq_self),
+ libcfs_id2str(req->rq_peer), req->rq_xid,
+ req->rq_reqlen,ptlrpc_rqphase2str(req));
+
+ if (svc->srv_request_history_print_fn == NULL)
+ seq_printf(s, "\n");
+ else
+ svc->srv_request_history_print_fn(s, srhi->srhi_req);
+ }
+
+ spin_unlock(&svc->srv_lock);
+
+ return rc;
+}
+
+static int
+ptlrpc_lprocfs_svc_req_history_open(struct inode *inode, struct file *file)
+{
+ static struct seq_operations sops = {
+ .start = ptlrpc_lprocfs_svc_req_history_start,
+ .stop = ptlrpc_lprocfs_svc_req_history_stop,
+ .next = ptlrpc_lprocfs_svc_req_history_next,
+ .show = ptlrpc_lprocfs_svc_req_history_show,
+ };
+ struct proc_dir_entry *dp = PDE(inode);
+ struct seq_file *seqf;
+ int rc;
+
+ LPROCFS_ENTRY_AND_CHECK(dp);
+ rc = seq_open(file, &sops);
+ if (rc) {
+ LPROCFS_EXIT();
+ return rc;
+ }
+
+ seqf = file->private_data;
+ seqf->private = dp->data;
+ return 0;
+}
+