Since we can enable write-behind mode by write backlog node,
so create wb_info_pool if the mode is just enabled, also call
call md_bitmap_update_sb to make user aware the write-behind
mode is enabled. Conversely, wb_info_pool should be destroyed
when write-behind mode is disabled.
Beside above, it is better to update bitmap sb if we change
the number of max_write_behind.
Reviewed-by: NeilBrown <neilb@xxxxxxxx>
Signed-off-by: Guoqing Jiang <gqjiang@xxxxxxxx>
---
drivers/md/md-bitmap.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index 3a62a46b75c7..e3403092c238 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -2461,12 +2461,26 @@ static ssize_t
backlog_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned long backlog;
+ unsigned long old_mwb = mddev->bitmap_info.max_write_behind;
int rv = kstrtoul(buf, 10, &backlog);
if (rv)
return rv;
if (backlog > COUNTER_MAX)
return -EINVAL;
mddev->bitmap_info.max_write_behind = backlog;
+ if (!backlog && mddev->wb_info_pool) {
+ /* wb_info_pool is not needed if backlog is zero */
+ mempool_destroy(mddev->wb_info_pool);
+ mddev->wb_info_pool = NULL;
+ } else if (backlog && !mddev->wb_info_pool) {
+ /* wb_info_pool is needed since backlog is not zero */
+ struct md_rdev *rdev;
+
+ rdev_for_each(rdev, mddev)
+ mddev_create_wb_pool(mddev, rdev, false);
+ }
+ if (old_mwb != backlog)
+ md_bitmap_update_sb(mddev->bitmap);
return len;
}
--
2.12.3
