[PATCH v5 06/15] md/md-bitmap: add md_bitmap_registered/enabled() helper

[Yu Kuai]

From: Yu Kuai <yuku...@huawei.com>

There are no functional changes, prepare to handle the case that
mddev->bitmap_ops can be NULL, which is possible after introducing
CONFIG_MD_BITMAP.

Signed-off-by: Yu Kuai <yuku...@huawei.com>
---
 drivers/md/md-bitmap.c | 16 ++++------------
 drivers/md/md-bitmap.h | 19 ++++++++++++++++++-
 drivers/md/raid1-10.c  |  2 +-
 3 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index 3f52716ea6f5..da2dcb3d2122 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -232,8 +232,10 @@ static inline char *bmname(struct bitmap *bitmap)
        return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
 }
 
-static bool __bitmap_enabled(struct bitmap *bitmap, bool flush)
+static bool bitmap_enabled(void *data, bool flush)
 {
+       struct bitmap *bitmap = data;
+
        if (!flush)
                return true;
 
@@ -245,16 +247,6 @@ static bool __bitmap_enabled(struct bitmap *bitmap, bool 
flush)
               bitmap->storage.filemap != NULL;
 }
 
-static bool bitmap_enabled(struct mddev *mddev, bool flush)
-{
-       struct bitmap *bitmap = mddev->bitmap;
-
-       if (!bitmap)
-               return false;
-
-       return __bitmap_enabled(bitmap, flush);
-}
-
 /*
  * check a page and, if necessary, allocate it (or hijack it if the alloc 
fails)
  *
@@ -1251,7 +1243,7 @@ static void __bitmap_unplug(struct bitmap *bitmap)
        int dirty, need_write;
        int writing = 0;
 
-       if (!__bitmap_enabled(bitmap, true))
+       if (!bitmap_enabled(bitmap, true))
                return;
 
        /* look at each page to see if there are any set bits that need to be
diff --git a/drivers/md/md-bitmap.h b/drivers/md/md-bitmap.h
index 63d91831655f..a36ed32ec0d5 100644
--- a/drivers/md/md-bitmap.h
+++ b/drivers/md/md-bitmap.h
@@ -62,7 +62,7 @@ struct md_bitmap_stats {
 };
 
 struct bitmap_operations {
-       bool (*enabled)(struct mddev *mddev, bool flush);
+       bool (*enabled)(void *data, bool flush);
        int (*create)(struct mddev *mddev);
        int (*resize)(struct mddev *mddev, sector_t blocks, int chunksize);
 
@@ -107,4 +107,21 @@ struct bitmap_operations {
 /* the bitmap API */
 void mddev_set_bitmap_ops(struct mddev *mddev);
 
+static inline bool md_bitmap_registered(struct mddev *mddev)
+{
+       return mddev->bitmap_ops != NULL;
+}
+
+static inline bool md_bitmap_enabled(struct mddev *mddev, bool flush)
+{
+       /* bitmap_ops must be registered before creating bitmap. */
+       if (!md_bitmap_registered(mddev))
+               return false;
+
+       if (!mddev->bitmap)
+               return false;
+
+       return mddev->bitmap_ops->enabled(mddev->bitmap, flush);
+}
+
 #endif
diff --git a/drivers/md/raid1-10.c b/drivers/md/raid1-10.c
index 4ad051d49cdc..0ad8b28ab7c2 100644
--- a/drivers/md/raid1-10.c
+++ b/drivers/md/raid1-10.c
@@ -140,7 +140,7 @@ static inline bool raid1_add_bio_to_plug(struct mddev 
*mddev, struct bio *bio,
         * If bitmap is not enabled, it's safe to submit the io directly, and
         * this can get optimal performance.
         */
-       if (!mddev->bitmap_ops->enabled(mddev, true)) {
+       if (!md_bitmap_enabled(mddev, true)) {
                raid1_submit_write(bio);
                return true;
        }
-- 
2.39.2