raid5: journal disk can't be removed
raid5-cache uses journal disk rdev->bdev, rdev->mddev in several places.
Don't allow journal disk disappear magically. On the other hand, we do
need to update superblock for other disks to bump up ->events, so next
time journal disk will be identified as stale.
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 216fa3c..693c000 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -7128,6 +7128,15 @@
struct disk_info *p = conf->disks + number;
print_raid5_conf(conf);
+ if (test_bit(Journal, &rdev->flags)) {
+ /*
+ * journal disk is not removable, but we need give a chance to
+ * update superblock of other disks. Otherwise journal disk
+ * will be considered as 'fresh'
+ */
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ return -EINVAL;
+ }
if (rdev == p->rdev)
rdevp = &p->rdev;
else if (rdev == p->replacement)
@@ -7190,6 +7199,8 @@
int first = 0;
int last = conf->raid_disks - 1;
+ if (test_bit(Journal, &rdev->flags))
+ return -EINVAL;
if (mddev->recovery_disabled == conf->recovery_disabled)
return -EBUSY;