[088/146] md/bitmap: fix saving of events_cleared and other state.

Greg KH
2011-06-01T09:15:34Z

From: NeilBrown <neilb@suse.de>

commit 8258c53208d7a9b7207e7d4dae36d2ea384cb278 upstream.

If a bitmap is found to be 'stale' the events_cleared value
is set to match 'events'.
However if the array is degraded this does not get stored on disk.
This can subsequently lead to incorrect behaviour.

So change bitmap_update_sb to always update events_cleared in the
superblock from the known events_cleared.
For neatness also set ->state from ->flags.
This requires updating ->state whenever we update ->flags, which makes
sense anyway.

This is suitable for any active -stable release.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/md/bitmap.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -493,11 +493,11 @@ void bitmap_update_sb(struct bitmap *bit
spin_unlock_irqrestore(&bitmap->lock, flags);
sb = kmap_atomic(bitmap->sb_page, KM_USER0);
sb->events = cpu_to_le64(bitmap->mddev->events);
- if (bitmap->mddev->events < bitmap->events_cleared) {
+ if (bitmap->mddev->events < bitmap->events_cleared)
/* rocking back to read-only */
bitmap->events_cleared = bitmap->mddev->events;
- sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
- }
+ sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
+ sb->state = cpu_to_le32(bitmap->flags);
/* Just in case these have been changed via sysfs: */
sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
@@ -618,7 +618,7 @@ success:
if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
bitmap->flags |= BITMAP_HOSTENDIAN;
bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
- if (sb->state & cpu_to_le32(BITMAP_STALE))
+ if (bitmap->flags & BITMAP_STALE)
bitmap->events_cleared = bitmap->mddev->events;
err = 0;
out:
@@ -652,9 +652,11 @@ static int bitmap_mask_state(struct bitm
switch (op) {
case MASK_SET:
sb->state |= cpu_to_le32(bits);
+ bitmap->flags |= bits;
break;
case MASK_UNSET:
sb->state &= cpu_to_le32(~bits);
+ bitmap->flags &= ~bits;
break;
default:
BUG();