bcachefs: bch2_journal_log_msg()

This adds bch2_journal_log_msg(), which just logs a message to the
journal, and uses it to mark startup and when journal replay finishes.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

fs/bcachefs/journal.c

@@ -630,31 +630,6 @@ int bch2_journal_flush_seq(struct journal *j, u64 seq)
 	return ret ?: ret2 < 0 ? ret2 : 0;
 }
 
-int bch2_journal_meta(struct journal *j)
-{
-	struct journal_buf *buf;
-	struct journal_res res;
-	int ret;
-
-	memset(&res, 0, sizeof(res));
-
-	ret = bch2_journal_res_get(j, &res, jset_u64s(0), 0);
-	if (ret)
-		return ret;
-
-	buf = j->buf + (res.seq & JOURNAL_BUF_MASK);
-	buf->must_flush = true;
-
-	if (!buf->flush_time) {
-		buf->flush_time	= local_clock() ?: 1;
-		buf->expires = jiffies;
-	}
-
-	bch2_journal_res_put(j, &res);
-
-	return bch2_journal_flush_seq(j, res.seq);
-}
-
 /*
  * bch2_journal_flush_async - if there is an open journal entry, or a journal
  * still being written, write it and wait for the write to complete
@@ -707,6 +682,64 @@ bool bch2_journal_noflush_seq(struct journal *j, u64 seq)
 	return ret;
 }
 
+int bch2_journal_meta(struct journal *j)
+{
+	struct journal_buf *buf;
+	struct journal_res res;
+	int ret;
+
+	memset(&res, 0, sizeof(res));
+
+	ret = bch2_journal_res_get(j, &res, jset_u64s(0), 0);
+	if (ret)
+		return ret;
+
+	buf = j->buf + (res.seq & JOURNAL_BUF_MASK);
+	buf->must_flush = true;
+
+	if (!buf->flush_time) {
+		buf->flush_time	= local_clock() ?: 1;
+		buf->expires = jiffies;
+	}
+
+	bch2_journal_res_put(j, &res);
+
+	return bch2_journal_flush_seq(j, res.seq);
+}
+
+int bch2_journal_log_msg(struct journal *j, const char *fmt, ...)
+{
+	struct jset_entry_log *entry;
+	struct journal_res res = { 0 };
+	unsigned msglen, u64s;
+	va_list args;
+	int ret;
+
+	va_start(args, fmt);
+	msglen = vsnprintf(NULL, 0, fmt, args) + 1;
+	va_end(args);
+
+	u64s = jset_u64s(DIV_ROUND_UP(msglen, sizeof(u64)));
+
+	ret = bch2_journal_res_get(j, &res, u64s, 0);
+	if (ret)
+		return ret;
+
+	entry = container_of(journal_res_entry(j, &res),
+			     struct jset_entry_log, entry);;
+	memset(entry, 0, u64s * sizeof(u64));
+	entry->entry.type = BCH_JSET_ENTRY_log;
+	entry->entry.u64s = u64s - 1;
+
+	va_start(args, fmt);
+	vsnprintf(entry->d, INT_MAX, fmt, args);
+	va_end(args);
+
+	bch2_journal_res_put(j, &res);
+
+	return bch2_journal_flush_seq(j, res.seq);
+}
+
 /* block/unlock the journal: */
 
 void bch2_journal_unblock(struct journal *j)

fs/bcachefs/journal.h

@@ -478,6 +478,7 @@ int bch2_journal_flush_seq(struct journal *, u64);
 int bch2_journal_flush(struct journal *);
 bool bch2_journal_noflush_seq(struct journal *, u64);
 int bch2_journal_meta(struct journal *);
+int bch2_journal_log_msg(struct journal *, const char *, ...);
 
 void bch2_journal_halt(struct journal *);
 

fs/bcachefs/recovery.c

@@ -578,6 +578,9 @@ static int bch2_journal_replay(struct bch_fs *c)
 	bch2_journal_set_replay_done(j);
 	bch2_journal_flush_all_pins(j);
 	ret = bch2_journal_error(j);
+
+	if (keys->nr && !ret)
+		bch2_journal_log_msg(&c->journal, "journal replay finished");
 err:
 	kvfree(keys_sorted);
 	return ret;