md: cleanup mddev flag clear for takeover

Commit 6995f0b (md: takeover should clear unrelated bits) clear
unrelated bits, but it's quite fragile. To avoid error in the future,
define a macro for unsupported mddev flags for each raid type and use it
to clear unsupported mddev flags. This should be less error-prone.

Suggested-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 14422407e520..7b0f647bcccb 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -42,6 +42,10 @@
 #include "raid1.h"
 #include "bitmap.h"
 
+#define UNSUPPORTED_MDDEV_FLAGS         \
+        ((1L << MD_HAS_JOURNAL) |       \
+         (1L << MD_JOURNAL_CLEAN))
+
 /*
  * Number of guaranteed r1bios in case of extreme VM load:
  */
@@ -3257,8 +3261,8 @@ static void *raid1_takeover(struct mddev *mddev)
                 if (!IS_ERR(conf)) {
                         /* Array must appear to be quiesced */
                         conf->array_frozen = 1;
-                        clear_bit(MD_HAS_JOURNAL, &mddev->flags);
-                        clear_bit(MD_JOURNAL_CLEAN, &mddev->flags);
+                        mddev_clear_unsupported_flags(mddev,
+                                UNSUPPORTED_MDDEV_FLAGS);
                 }
                 return conf;
         }