From 10c92fca636e40dcb15d85ffe06b1b6843cd28fc Mon Sep 17 00:00:00 2001 From: Guoqing Jiang Date: Fri, 14 Jun 2019 17:10:37 +0800 Subject: [PATCH] md-bitmap: create and destroy wb_info_pool with the change of backlog 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 Signed-off-by: Guoqing Jiang Signed-off-by: Song Liu --- 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 c01d411..15dd817 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -2462,12 +2462,26 @@ 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; } -- 2.7.4