bcachefs: Better journal tracepoints

Factor out bch2_journal_bufs_to_text(), and use it in the
journal_entry_full() tracepoint; when we can't get a journal reservation
we need to know the outstanding journal entry sizes to know if the
problem is due to excessive flushing.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/journal.c b/fs/bcachefs/journal.c
index 8538ef34f62bc54e8bc570acbe793e4771745247..d71d26e39521e4410a90cb6bf3e21df360e6c201 100644 (file)
--- a/fs/bcachefs/journal.c
+++ b/fs/bcachefs/journal.c
@@ -27,6 +27,47 @@ static const char * const bch2_journal_errors[] = {
        NULL
 };
 
+static void bch2_journal_buf_to_text(struct printbuf *out, struct journal *j, u64 seq)
+{
+       union journal_res_state s = READ_ONCE(j->reservations);
+       unsigned i = seq & JOURNAL_BUF_MASK;
+       struct journal_buf *buf = j->buf + i;
+
+       prt_printf(out, "seq:");
+       prt_tab(out);
+       prt_printf(out, "%llu", seq);
+       prt_newline(out);
+       printbuf_indent_add(out, 2);
+
+       prt_printf(out, "refcount:");
+       prt_tab(out);
+       prt_printf(out, "%u", journal_state_count(s, i));
+       prt_newline(out);
+
+       prt_printf(out, "size:");
+       prt_tab(out);
+       prt_human_readable_u64(out, vstruct_bytes(buf->data));
+       prt_newline(out);
+
+       prt_printf(out, "expires");
+       prt_tab(out);
+       prt_printf(out, "%li jiffies", buf->expires - jiffies);
+       prt_newline(out);
+
+       printbuf_indent_sub(out, 2);
+}
+
+static void bch2_journal_bufs_to_text(struct printbuf *out, struct journal *j)
+{
+       if (!out->nr_tabstops)
+               printbuf_tabstop_push(out, 24);
+
+       for (u64 seq = journal_last_unwritten_seq(j);
+            seq <= journal_cur_seq(j);
+            seq++)
+               bch2_journal_buf_to_text(out, j, seq);
+}
+
 static inline bool journal_seq_unwritten(struct journal *j, u64 seq)
 {
        return seq > j->seq_ondisk;
@@ -156,7 +197,7 @@ void bch2_journal_buf_put_final(struct journal *j, u64 seq, bool write)
  * We don't close a journal_buf until the next journal_buf is finished writing,
  * and can be opened again - this also initializes the next journal_buf:
  */
-static void __journal_entry_close(struct journal *j, unsigned closed_val)
+static void __journal_entry_close(struct journal *j, unsigned closed_val, bool trace)
 {
        struct bch_fs *c = container_of(j, struct bch_fs, journal);
        struct journal_buf *buf = journal_cur_buf(j);
@@ -185,7 +226,17 @@ static void __journal_entry_close(struct journal *j, unsigned closed_val)
        /* Close out old buffer: */
        buf->data->u64s         = cpu_to_le32(old.cur_entry_offset);
 
-       trace_journal_entry_close(c, vstruct_bytes(buf->data));
+       if (trace_journal_entry_close_enabled() && trace) {
+               struct printbuf pbuf = PRINTBUF;
+               pbuf.atomic++;
+
+               prt_str(&pbuf, "entry size: ");
+               prt_human_readable_u64(&pbuf, vstruct_bytes(buf->data));
+               prt_newline(&pbuf);
+               bch2_prt_task_backtrace(&pbuf, current, 1);
+               trace_journal_entry_close(c, pbuf.buf);
+               printbuf_exit(&pbuf);
+       }
 
        sectors = vstruct_blocks_plus(buf->data, c->block_bits,
                                      buf->u64s_reserved) << c->block_bits;
@@ -225,7 +276,7 @@ static void __journal_entry_close(struct journal *j, unsigned closed_val)
 void bch2_journal_halt(struct journal *j)
 {
        spin_lock(&j->lock);
-       __journal_entry_close(j, JOURNAL_ENTRY_ERROR_VAL);
+       __journal_entry_close(j, JOURNAL_ENTRY_ERROR_VAL, true);
        if (!j->err_seq)
                j->err_seq = journal_cur_seq(j);
        journal_wake(j);
@@ -239,7 +290,7 @@ static bool journal_entry_want_write(struct journal *j)
 
        /* Don't close it yet if we already have a write in flight: */
        if (ret)
-               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL);
+               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
        else if (nr_unwritten_journal_entries(j)) {
                struct journal_buf *buf = journal_cur_buf(j);
 
@@ -406,7 +457,7 @@ static void journal_write_work(struct work_struct *work)
        if (delta > 0)
                mod_delayed_work(c->io_complete_wq, &j->write_work, delta);
        else
-               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL);
+               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
 unlock:
        spin_unlock(&j->lock);
 }
@@ -463,13 +514,21 @@ retry:
            buf->buf_size < JOURNAL_ENTRY_SIZE_MAX)
                j->buf_size_want = max(j->buf_size_want, buf->buf_size << 1);
 
-       __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL);
+       __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, false);
        ret = journal_entry_open(j);
 
        if (ret == JOURNAL_ERR_max_in_flight) {
                track_event_change(&c->times[BCH_TIME_blocked_journal_max_in_flight],
                                   &j->max_in_flight_start, true);
-               trace_and_count(c, journal_entry_full, c);
+               if (trace_journal_entry_full_enabled()) {
+                       struct printbuf buf = PRINTBUF;
+                       buf.atomic++;
+
+                       bch2_journal_bufs_to_text(&buf, j);
+                       trace_journal_entry_full(c, buf.buf);
+                       printbuf_exit(&buf);
+               }
+               count_event(c, journal_entry_full);
        }
 unlock:
        can_discard = j->can_discard;
@@ -549,7 +608,7 @@ void bch2_journal_entry_res_resize(struct journal *j,
                /*
                 * Not enough room in current journal entry, have to flush it:
                 */
-               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL);
+               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
        } else {
                journal_cur_buf(j)->u64s_reserved += d;
        }
@@ -606,7 +665,7 @@ recheck_need_open:
                struct journal_res res = { 0 };
 
                if (journal_entry_is_open(j))
-                       __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL);
+                       __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
 
                spin_unlock(&j->lock);
 
@@ -786,7 +845,7 @@ static struct journal_buf *__bch2_next_write_buffer_flush_journal_buf(struct jou
 
                if (buf->need_flush_to_write_buffer) {
                        if (seq == journal_cur_seq(j))
-                               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL);
+                               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
 
                        union journal_res_state s;
                        s.v = atomic64_read_acquire(&j->reservations.counter);
@@ -1339,35 +1398,9 @@ void __bch2_journal_debug_to_text(struct printbuf *out, struct journal *j)
        }
 
        prt_newline(out);
-
-       for (u64 seq = journal_cur_seq(j);
-            seq >= journal_last_unwritten_seq(j);
-            --seq) {
-               unsigned i = seq & JOURNAL_BUF_MASK;
-
-               prt_printf(out, "unwritten entry:");
-               prt_tab(out);
-               prt_printf(out, "%llu", seq);
-               prt_newline(out);
-               printbuf_indent_add(out, 2);
-
-               prt_printf(out, "refcount:");
-               prt_tab(out);
-               prt_printf(out, "%u", journal_state_count(s, i));
-               prt_newline(out);
-
-               prt_printf(out, "sectors:");
-               prt_tab(out);
-               prt_printf(out, "%u", j->buf[i].sectors);
-               prt_newline(out);
-
-               prt_printf(out, "expires");
-               prt_tab(out);
-               prt_printf(out, "%li jiffies", j->buf[i].expires - jiffies);
-               prt_newline(out);
-
-               printbuf_indent_sub(out, 2);
-       }
+       prt_printf(out, "unwritten entries:");
+       prt_newline(out);
+       bch2_journal_bufs_to_text(out, j);
 
        prt_printf(out,
               "replay done:\t\t%i\n",

diff --git a/fs/bcachefs/trace.h b/fs/bcachefs/trace.h
index 8292efc3289ba3b52a2b0ea276926e6b19e24323..ea307ed49424e2d11969a4380ae64c870fd42cf5 100644 (file)
--- a/fs/bcachefs/trace.h
+++ b/fs/bcachefs/trace.h
@@ -46,7 +46,7 @@ DECLARE_EVENT_CLASS(fs_str,
                __assign_str(str, str);
        ),
 
-       TP_printk("%d,%d %s", MAJOR(__entry->dev), MINOR(__entry->dev), __get_str(str))
+       TP_printk("%d,%d\n%s", MAJOR(__entry->dev), MINOR(__entry->dev), __get_str(str))
 );
 
 DECLARE_EVENT_CLASS(trans_str,
@@ -273,28 +273,14 @@ DEFINE_EVENT(bch_fs, journal_full,
        TP_ARGS(c)
 );
 
-DEFINE_EVENT(bch_fs, journal_entry_full,
-       TP_PROTO(struct bch_fs *c),
-       TP_ARGS(c)
+DEFINE_EVENT(fs_str, journal_entry_full,
+       TP_PROTO(struct bch_fs *c, const char *str),
+       TP_ARGS(c, str)
 );
 
-TRACE_EVENT(journal_entry_close,
-       TP_PROTO(struct bch_fs *c, unsigned bytes),
-       TP_ARGS(c, bytes),
-
-       TP_STRUCT__entry(
-               __field(dev_t,          dev                     )
-               __field(u32,            bytes                   )
-       ),
-
-       TP_fast_assign(
-               __entry->dev                    = c->dev;
-               __entry->bytes                  = bytes;
-       ),
-
-       TP_printk("%d,%d entry bytes %u",
-                 MAJOR(__entry->dev), MINOR(__entry->dev),
-                 __entry->bytes)
+DEFINE_EVENT(fs_str, journal_entry_close,
+       TP_PROTO(struct bch_fs *c, const char *str),
+       TP_ARGS(c, str)
 );
 
 DEFINE_EVENT(bio, journal_write,