block: ensure bdi->io_pages is always initialized

commit de1b0ee490eafdf65fac9eef9925391a8369f2dc upstream.

If a driver leaves the limit settings as the defaults, then we don't
initialize bdi->io_pages. This means that file systems may need to
work around bdi->io_pages == 0, which is somewhat messy.

Initialize the default value just like we do for ->ra_pages.

Cc: stable@vger.kernel.org
Fixes: 9491ae4aade6 ("mm: don't cap request size based on read-ahead setting")
Reported-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/block/blk-core.c b/block/blk-core.c
index d5e668ec751b50f8cbdba497108e6f46a4a2409a..ca6b677356864367748a0488a35baa397d008aab 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -502,6 +502,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
                goto fail_stats;
 
        q->backing_dev_info->ra_pages = VM_READAHEAD_PAGES;
+       q->backing_dev_info->io_pages = VM_READAHEAD_PAGES;
        q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK;
        q->backing_dev_info->name = "block";
        q->node = node_id;