+ struct cfs_trace_cpu_data *tcd = NULL;
+ struct ptldebug_header header = {0};
+ struct cfs_trace_page *tage;
+ /* string_buf is used only if tcd != NULL, and is always set then */
+ char *string_buf = NULL;
+ char *debug_buf;
+ int known_size;
+ int needed = 85; /* seeded with average message length */
+ int max_nob;
+ va_list ap;
+ int retry;
+ int mask = msgdata->msg_mask;
+ char *file = (char *)msgdata->msg_file;
+ struct cfs_debug_limit_state *cdls = msgdata->msg_cdls;
+
+ if (strchr(file, '/'))
+ file = strrchr(file, '/') + 1;
+
+ tcd = cfs_trace_get_tcd();
+
+ /* cfs_trace_get_tcd() grabs a lock, which disables preemption and
+ * pins us to a particular CPU. This avoids an smp_processor_id()
+ * warning on Linux when debugging is enabled.
+ */
+ cfs_set_ptldebug_header(&header, msgdata, CDEBUG_STACK());
+
+ if (!tcd) /* arch may not log in IRQ context */
+ goto console;
+
+ if (tcd->tcd_cur_pages == 0)
+ header.ph_flags |= PH_FLAG_FIRST_RECORD;
+
+ if (tcd->tcd_shutting_down) {
+ cfs_trace_put_tcd(tcd);
+ tcd = NULL;
+ goto console;
+ }
+
+ known_size = strlen(file) + 1;
+ if (msgdata->msg_fn)
+ known_size += strlen(msgdata->msg_fn) + 1;
+
+ if (libcfs_debug_binary)
+ known_size += sizeof(header);
+
+ /*
+ * May perform an additional pass to update 'needed' and increase
+ * tage buffer size to match vsnprintf reported size required
+ * On the second pass (retry=1) use vscnprintf [which returns
+ * number of bytes written not including the terminating nul]
+ * to clarify `needed` is used as number of bytes written
+ * for the remainder of this function
+ */
+ for (retry = 0; retry < 2; retry++) {
+ tage = cfs_trace_get_tage(tcd, needed + known_size + 1);
+ if (!tage) {
+ if (needed + known_size > PAGE_SIZE)
+ mask |= D_ERROR;
+
+ cfs_trace_put_tcd(tcd);
+ tcd = NULL;
+ goto console;
+ }
+
+ string_buf = (char *)page_address(tage->page) +
+ tage->used + known_size;
+
+ max_nob = PAGE_SIZE - tage->used - known_size;
+ if (max_nob <= 0) {
+ pr_emerg("LustreError: negative max_nob: %d\n",
+ max_nob);
+ mask |= D_ERROR;
+ cfs_trace_put_tcd(tcd);
+ tcd = NULL;
+ goto console;
+ }
+
+ va_start(ap, format);
+ if (retry)
+ needed = vscnprintf(string_buf, max_nob, format, ap);
+ else
+ needed = vsnprintf(string_buf, max_nob, format, ap);
+ va_end(ap);
+
+ if (needed < max_nob) /* well. printing ok.. */
+ break;
+ }
+
+ /* `needed` is actual bytes written to string_buf */
+ if (*(string_buf + needed - 1) != '\n') {
+ pr_info("Lustre: format at %s:%d:%s doesn't end in newline\n",
+ file, msgdata->msg_line, msgdata->msg_fn);
+ } else if (mask & D_TTY) {
+ /* TTY needs '\r\n' to move carriage to leftmost position */
+ if (needed < 2 || *(string_buf + needed - 2) != '\r')
+ pr_info("Lustre: format at %s:%d:%s doesn't end in '\\r\\n'\n",
+ file, msgdata->msg_line, msgdata->msg_fn);
+ if (strnchr(string_buf, needed, '%'))
+ pr_info("Lustre: format at %s:%d:%s mustn't contain %%\n",
+ file, msgdata->msg_line, msgdata->msg_fn);
+ }
+
+ header.ph_len = known_size + needed;
+ debug_buf = (char *)page_address(tage->page) + tage->used;
+
+ if (libcfs_debug_binary) {
+ memcpy(debug_buf, &header, sizeof(header));
+ tage->used += sizeof(header);
+ debug_buf += sizeof(header);
+ }
+
+ strlcpy(debug_buf, file, PAGE_SIZE - tage->used);
+ tage->used += strlen(file) + 1;
+ debug_buf += strlen(file) + 1;
+
+ if (msgdata->msg_fn) {
+ strlcpy(debug_buf, msgdata->msg_fn, PAGE_SIZE - tage->used);
+ tage->used += strlen(msgdata->msg_fn) + 1;
+ debug_buf += strlen(msgdata->msg_fn) + 1;
+ }
+
+ __LASSERT(debug_buf == string_buf);
+
+ tage->used += needed;
+ __LASSERT(tage->used <= PAGE_SIZE);
+
+console:
+ if ((mask & libcfs_printk) == 0) {
+ /* no console output requested */
+ if (tcd != NULL)
+ cfs_trace_put_tcd(tcd);
+ return 1;
+ }
+
+ if (cdls != NULL) {
+ if (libcfs_console_ratelimit &&
+ cdls->cdls_next != 0 && /* not first time ever */
+ time_before(jiffies, cdls->cdls_next)) {
+ /* skipping a console message */
+ cdls->cdls_count++;
+ if (tcd != NULL)
+ cfs_trace_put_tcd(tcd);
+ return 1;
+ }
+
+ if (time_after(jiffies, cdls->cdls_next +
+ libcfs_console_max_delay +
+ cfs_time_seconds(10))) {
+ /* last timeout was a long time ago */
+ cdls->cdls_delay /= libcfs_console_backoff * 4;
+ } else {
+ cdls->cdls_delay *= libcfs_console_backoff;
+ }
+
+ if (cdls->cdls_delay < libcfs_console_min_delay)
+ cdls->cdls_delay = libcfs_console_min_delay;
+ else if (cdls->cdls_delay > libcfs_console_max_delay)
+ cdls->cdls_delay = libcfs_console_max_delay;
+
+ /* ensure cdls_next is never zero after it's been seen */
+ cdls->cdls_next = (jiffies + cdls->cdls_delay) | 1;
+ }
+
+ if (tcd) {
+ cfs_print_to_console(&header, mask, file, msgdata->msg_fn,
+ "%s", string_buf);
+ cfs_trace_put_tcd(tcd);
+ } else {
+ struct va_format vaf;
+
+ va_start(ap, format);
+ vaf.fmt = format;
+ vaf.va = ≈
+ cfs_vprint_to_console(&header, mask,
+ &vaf, file, msgdata->msg_fn);
+ va_end(ap);
+ }
+
+ if (cdls != NULL && cdls->cdls_count != 0) {
+ /* Do not allow print this to TTY */
+ cfs_print_to_console(&header, mask & ~D_TTY, file,
+ msgdata->msg_fn,
+ "Skipped %d previous similar message%s\n",
+ cdls->cdls_count,
+ (cdls->cdls_count > 1) ? "s" : "");
+
+ cdls->cdls_count = 0;
+ }
+
+ return 0;