[PATCH 2/9] bdi: move bdi_dev_name out of line

From: Christoph Hellwig
Date: Wed Apr 22 2020 - 03:39:49 EST


bdi_dev_name is not a fast path function, move it out of line. This
prepares for using it from modular callers without having to export
an implementation detail like bdi_unknown_name.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/backing-dev.h | 9 +--------
mm/backing-dev.c | 10 +++++++++-
2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index f88197c1ffc2..c9ad5c3b7b4b 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -505,13 +505,6 @@ static inline int bdi_rw_congested(struct backing_dev_info *bdi)
(1 << WB_async_congested));
}

-extern const char *bdi_unknown_name;
-
-static inline const char *bdi_dev_name(struct backing_dev_info *bdi)
-{
- if (!bdi || !bdi->dev)
- return bdi_unknown_name;
- return dev_name(bdi->dev);
-}
+const char *bdi_dev_name(struct backing_dev_info *bdi);

#endif /* _LINUX_BACKING_DEV_H */
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index c81b4f3a7268..c2c44c89ee5d 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -21,7 +21,7 @@ struct backing_dev_info noop_backing_dev_info = {
EXPORT_SYMBOL_GPL(noop_backing_dev_info);

static struct class *bdi_class;
-const char *bdi_unknown_name = "(unknown)";
+static const char *bdi_unknown_name = "(unknown)";

/*
* bdi_lock protects bdi_tree and updates to bdi_list. bdi_list has RCU
@@ -1043,6 +1043,14 @@ void bdi_put(struct backing_dev_info *bdi)
}
EXPORT_SYMBOL(bdi_put);

+const char *bdi_dev_name(struct backing_dev_info *bdi)
+{
+ if (!bdi || !bdi->dev)
+ return bdi_unknown_name;
+ return dev_name(bdi->dev);
+}
+EXPORT_SYMBOL_GPL(bdi_dev_name);
+
static wait_queue_head_t congestion_wqh[2] = {
__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]),
__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1])
--
2.26.1