Set the last mount time using the realtime clock

This way the last mount time is actually meaningful instead of just being
various times from 1970 (which happens with the monotonic clock).

Also, roundup_pow_of_two() is undefined when passed in 0, so check before
calling it.

2 files changed, 6 insertions, 4 deletions

diff --git a/fs/bcachefs/fifo.h b/fs/bcachefs/fifo.h
index 085d828e6ed1..9715ddbdae56 100644
--- a/fs/bcachefs/fifo.h
+++ b/fs/bcachefs/fifo.h
@@ -12,7 +12,9 @@ struct {								\
 #define DECLARE_FIFO(type, name)	FIFO(type) name
 
 #define fifo_buf_size(fifo)						\
-	(roundup_pow_of_two((fifo)->size) * sizeof((fifo)->data[0]))
+	((fifo)->size							\
+	 ? roundup_pow_of_two((fifo)->size) * sizeof((fifo)->data[0])	\
+	 : 0)
 
 #define init_fifo(fifo, _size, _gfp)					\
 ({									\
diff --git a/fs/bcachefs/super.c b/fs/bcachefs/super.c
index b7a6f5fb88a8..dded527d7d53 100644
--- a/fs/bcachefs/super.c
+++ b/fs/bcachefs/super.c
@@ -686,7 +686,7 @@ const char *bch2_fs_start(struct bch_fs *c)
 	const char *err = "cannot allocate memory";
 	struct bch_sb_field_members *mi;
 	struct bch_dev *ca;
-	time64_t now = ktime_get_seconds();
+	time64_t now = ktime_get_real_seconds();
 	unsigned i;
 	int ret = -EINVAL;
 
@@ -1456,7 +1456,7 @@ have_slot:
 	/* success: */
 
 	mi->members[dev_idx] = dev_mi;
-	mi->members[dev_idx].last_mount = cpu_to_le64(ktime_get_seconds());
+	mi->members[dev_idx].last_mount = cpu_to_le64(ktime_get_real_seconds());
 	c->disk_sb.sb->nr_devices	= nr_devices;
 
 	ca->disk_sb.sb->dev_idx	= dev_idx;
@@ -1532,7 +1532,7 @@ int bch2_dev_online(struct bch_fs *c, const char *path)
 	mi = bch2_sb_get_members(c->disk_sb.sb);
 
 	mi->members[ca->dev_idx].last_mount =
-		cpu_to_le64(ktime_get_seconds());
+		cpu_to_le64(ktime_get_real_seconds());
 
 	bch2_write_super(c);
 	mutex_unlock(&c->sb_lock);