Commit a042210648ed ("disallow create or grow clustered bitmap with
writemostly set") introduced this bug. We should use 'true' logic not
'== 0' to deny setting up clustered array under WRITEMOSTLY condition.
How to trigger
```
~/mdadm # ./mdadm -Ss && ./mdadm --zero-superblock /dev/sd{a,b}
~/mdadm # ./mdadm -C /dev/md0 -l mirror -b clustered -e 1.2 -n 2 \
/dev/sda /dev/sdb --assume-clean
mdadm: array /dev/md0 started.
~/mdadm # ./mdadm --grow /dev/md0 --bitmap=none
~/mdadm # ./mdadm --grow /dev/md0 --bitmap=clustered
mdadm: /dev/md0 disks marked write-mostly are not supported with clustered bitmap
```
Signed-off-by: Heming Zhao <heming.zhao@xxxxxxxx>
---
Grow.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Grow.c b/Grow.c
index 8f5cf07d10d9..bb5fe45c851c 100644
--- a/Grow.c
+++ b/Grow.c
@@ -429,7 +429,7 @@ int Grow_addbitmap(char *devname, int fd, struct context *c, struct shape *s)
dv = map_dev(disk.major, disk.minor, 1);
if (!dv)
continue;
- if (((disk.state & (1 << MD_DISK_WRITEMOSTLY)) == 0) &&
+ if ((disk.state & (1 << MD_DISK_WRITEMOSTLY)) &&
(strcmp(s->bitmap_file, "clustered") == 0)) {
pr_err("%s disks marked write-mostly are not supported with clustered bitmap\n",devname);
free(mdi);
--
2.39.1
