bcache: Reduce the number of sparse complaints about lock imbalances

BugLink: https://bugs.launchpad.net/bugs/1784665

Add more annotations for sparse to inform it about which functions do
not have the same number of spin_lock() and spin_unlock() calls.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit 20d3a518)
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/md/bcache/journal.c

@@ -610,6 +610,7 @@ static void journal_write_done(struct closure *cl)
 }
 
 static void journal_write_unlock(struct closure *cl)
+	__releases(&c->journal.lock)
 {
 	struct cache_set *c = container_of(cl, struct cache_set, journal.io);
 
@@ -723,6 +724,7 @@ static void journal_try_write(struct cache_set *c)
 
 static struct journal_write *journal_wait_for_write(struct cache_set *c,
 						    unsigned nkeys)
+	__acquires(&c->journal.lock)
 {
 	size_t sectors;
 	struct closure cl;