kmem_cache_free(event_cache, event);
}
+/*
+ * We have exclusive access to our metadata buffer (protected by the
+ * sessions_mutex), so we can do racy operations such as looking for
+ * remaining space left in packet and write, since mutual exclusion
+ * protects us from concurrent writes.
+ */
int lttng_metadata_printf(struct ltt_session *session,
const char *fmt, ...)
{
struct ltt_channel *chan = session->metadata;
char *str;
int ret = 0, waitret;
- size_t len;
+ size_t len, reserve_len, pos;
va_list ap;
WARN_ON_ONCE(!ACCESS_ONCE(session->active));
if (!str)
return -ENOMEM;
- len = strlen(str) + 1;
- lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, len, sizeof(char), -1);
- /*
- * We don't care about metadata buffer's records lost count, because we
- * always retry here. Report error if we need to bail out after timeout
- * or being interrupted.
- */
- waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan),
- ({
- ret = chan->ops->event_reserve(&ctx);
- ret != -ENOBUFS || !ret;
- }),
- msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC));
- if (!waitret || waitret == -ERESTARTSYS || ret) {
- printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n",
- waitret == -ERESTARTSYS ? "interrupted" :
- (ret == -ENOBUFS ? "timeout" : "I/O error"));
- printk("waitret %d retval %d\n", waitret, ret);
- if (waitret == -ERESTARTSYS)
- ret = waitret;
- goto end;
+ len = strlen(str);
+ pos = 0;
+
+ for (pos = 0; pos < len; pos += reserve_len) {
+ reserve_len = min_t(size_t,
+ chan->ops->packet_avail_size(chan->chan),
+ len - pos);
+ lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
+ sizeof(char), -1);
+ /*
+ * We don't care about metadata buffer's records lost
+ * count, because we always retry here. Report error if
+ * we need to bail out after timeout or being
+ * interrupted.
+ */
+ waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan),
+ ({
+ ret = chan->ops->event_reserve(&ctx);
+ ret != -ENOBUFS || !ret;
+ }),
+ msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC));
+ if (!waitret || waitret == -ERESTARTSYS || ret) {
+ printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n",
+ waitret == -ERESTARTSYS ? "interrupted" :
+ (ret == -ENOBUFS ? "timeout" : "I/O error"));
+ if (waitret == -ERESTARTSYS)
+ ret = waitret;
+ goto end;
+ }
+ chan->ops->event_write(&ctx, &str[pos], len);
+ chan->ops->event_commit(&ctx);
}
- chan->ops->event_write(&ctx, str, len);
- chan->ops->event_commit(&ctx);
end:
kfree(str);
return ret;
" byte_order = %s;\n"
" packet.header := struct {\n"
" uint32_t magic;\n"
- " uint8_t trace_uuid[16];\n"
+ " uint8_t uuid[16];\n"
" uint32_t stream_id;\n"
" uint64_t timestamp_begin;\n"
" uint64_t timestamp_end;\n"