md-bitmap: create and destroy wb_info_pool with the change of backlog (10c92fca) · Commits · 戴 / test

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@suse.com> Signed-off-by:

Guoqing Jiang <gqjiang@suse.com> Signed-off-by:

Song Liu <songliubraving@fb.com>

drivers/md/md-bitmap.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}

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