brd: decrease the number of allocated pages which discarded

The number of allocated pages which discarded will not decrease.
Fix it.

Fixes: 9ead7efc6f3f ("brd: implement discard support")

Signed-off-by: Zhang Xianwei <zhang.xianwei8@zte.com.cn>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241128170056565nPKSz2vsP8K8X2uk2iaDG@zte.com.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 5a95671..292f127 100644 (file)
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -231,8 +231,10 @@ static void brd_do_discard(struct brd_device *brd, sector_t sector, u32 size)
        xa_lock(&brd->brd_pages);
        while (size >= PAGE_SIZE && aligned_sector < rd_size * 2) {
                page = __xa_erase(&brd->brd_pages, aligned_sector >> PAGE_SECTORS_SHIFT);
-               if (page)
+               if (page) {
                        __free_page(page);
+                       brd->brd_nr_pages--;
+               }
                aligned_sector += PAGE_SECTORS;
                size -= PAGE_SIZE;
        }