From 1046d304900cf9d4b2c730c6860b8e03cc704377 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 26 Jul 2017 15:32:23 +0100 Subject: [PATCH] virtio_blk: fix incorrect message when disk is resized The message printed on disk resize is incorrect. The following is printed when resizing to 2 GiB: $ truncate -s 1G test.img $ qemu -device virtio-blk-pci,logical_block_size=4096,... (qemu) block_resize drive1 2G virtio_blk virtio0: new size: 4194304 4096-byte logical blocks (17.2 GB/16.0 GiB) The virtio_blk capacity config field is in 512-byte sector units regardless of logical_block_size as per the VIRTIO specification. Therefore the message should read: virtio_blk virtio0: new size: 524288 4096-byte logical blocks (2.15 GB/2.0 GiB) Note that this only affects the printed message. Thankfully the actual block device has the correct size because the block layer expects capacity in sectors. Signed-off-by: Stefan Hajnoczi Signed-off-by: Michael S. Tsirkin --- drivers/block/virtio_blk.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 1498b899a593..d3d5523862c2 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -381,6 +381,7 @@ static void virtblk_config_changed_work(struct work_struct *work) struct request_queue *q = vblk->disk->queue; char cap_str_2[10], cap_str_10[10]; char *envp[] = { "RESIZE=1", NULL }; + unsigned long long nblocks; u64 capacity; /* Host must always specify the capacity. */ @@ -393,16 +394,19 @@ static void virtblk_config_changed_work(struct work_struct *work) capacity = (sector_t)-1; } - string_get_size(capacity, queue_logical_block_size(q), + nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); + + string_get_size(nblocks, queue_logical_block_size(q), STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); - string_get_size(capacity, queue_logical_block_size(q), + string_get_size(nblocks, queue_logical_block_size(q), STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); dev_notice(&vdev->dev, - "new size: %llu %d-byte logical blocks (%s/%s)\n", - (unsigned long long)capacity, - queue_logical_block_size(q), - cap_str_10, cap_str_2); + "new size: %llu %d-byte logical blocks (%s/%s)\n", + nblocks, + queue_logical_block_size(q), + cap_str_10, + cap_str_2); set_capacity(vblk->disk, capacity); revalidate_disk(vblk->disk); -- 2.20.1