[PATCH 6/7] bcachefs: bch2_dev_get_ioref() may now sleep

[Kent Overstreet <kent.overstreet@linux.dev>]

The next patch implementing freezing will change bch2_dev_get_ioref() to
sleep if a device is currently frozen.

Add an annotation and fix the journal code accordingly.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---
 fs/bcachefs/journal_io.c | 5 ++++-
 fs/bcachefs/sb-members.h | 2 ++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/bcachefs/journal_io.c b/fs/bcachefs/journal_io.c
index c12d9f9bd536..a510755a8364 100644
--- a/fs/bcachefs/journal_io.c
+++ b/fs/bcachefs/journal_io.c
@@ -1664,6 +1664,7 @@ static CLOSURE_CALLBACK(journal_write_done)
 	}
 
 	bool completed = false;
+	bool do_discards = false;
 
 	for (seq = journal_last_unwritten_seq(j);
 	     seq <= journal_cur_seq(j);
@@ -1676,7 +1677,6 @@ static CLOSURE_CALLBACK(journal_write_done)
 			j->flushed_seq_ondisk = seq;
 			j->last_seq_ondisk = w->last_seq;
 
-			bch2_do_discards(c);
 			closure_wake_up(&c->freelist_wait);
 			bch2_reset_alloc_cursors(c);
 		}
@@ -1727,6 +1727,9 @@ static CLOSURE_CALLBACK(journal_write_done)
 	 */
 	bch2_journal_do_writes(j);
 	spin_unlock(&j->lock);
+
+	if (do_discards)
+		bch2_do_discards(c);
 }
 
 static void journal_write_endio(struct bio *bio)
diff --git a/fs/bcachefs/sb-members.h b/fs/bcachefs/sb-members.h
index b29b6c6c21dd..df91b02ce575 100644
--- a/fs/bcachefs/sb-members.h
+++ b/fs/bcachefs/sb-members.h
@@ -283,6 +283,8 @@ static inline struct bch_dev *bch2_dev_iterate(struct bch_fs *c, struct bch_dev
 
 static inline struct bch_dev *bch2_dev_get_ioref(struct bch_fs *c, unsigned dev, int rw)
 {
+	might_sleep();
+
 	rcu_read_lock();
 	struct bch_dev *ca = bch2_dev_rcu(c, dev);
 	if (ca && !percpu_ref_tryget(&ca->io_ref))
-- 
2.47.2