Add new netlink attributes to allow the userspace nbd-client to control the minimum_io_size and optimal_io_size settings. This is the kernel part of an effort to implement NBD block size constraints. Signed-off-by: Richard W.M. Jones <rjones@xxxxxxxxxx> Link: https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md#block-size-constraints Link: https://lists.debian.org/nbd/2022/06/msg00022.html --- drivers/block/nbd.c | 17 ++++++++++++++++- include/uapi/linux/nbd-netlink.h | 2 ++ 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 07f3c139a3d7..ff51b5c577b2 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -99,6 +99,7 @@ struct nbd_config { wait_queue_head_t recv_wq; unsigned int blksize_bits; loff_t bytesize; + u32 minimum_io_size, optimal_io_size; #if IS_ENABLED(CONFIG_DEBUG_FS) struct dentry *dbg_dir; #endif @@ -338,6 +339,13 @@ static int nbd_set_size(struct nbd_device *nbd, loff_t bytesize, blk_queue_logical_block_size(nbd->disk->queue, blksize); blk_queue_physical_block_size(nbd->disk->queue, blksize); + if (nbd->config->minimum_io_size) + blk_queue_io_min(nbd->disk->queue, + nbd->config->minimum_io_size); + if (nbd->config->optimal_io_size) + blk_queue_io_opt(nbd->disk->queue, + nbd->config->optimal_io_size); + if (max_part) set_bit(GD_NEED_PART_SCAN, &nbd->disk->state); if (!set_capacity_and_notify(nbd->disk, bytesize >> 9)) @@ -1876,6 +1884,8 @@ static const struct nla_policy nbd_attr_policy[NBD_ATTR_MAX + 1] = { [NBD_ATTR_DEAD_CONN_TIMEOUT] = { .type = NLA_U64 }, [NBD_ATTR_DEVICE_LIST] = { .type = NLA_NESTED}, [NBD_ATTR_BACKEND_IDENTIFIER] = { .type = NLA_STRING}, + [NBD_ATTR_BLOCK_SIZE_MIN] = { .type = NLA_U32 }, + [NBD_ATTR_BLOCK_SIZE_OPT] = { .type = NLA_U32 }, }; static const struct nla_policy nbd_sock_policy[NBD_SOCK_MAX + 1] = { @@ -2031,7 +2041,12 @@ static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info) &config->runtime_flags); } } - + if (info->attrs[NBD_ATTR_BLOCK_SIZE_MIN]) + config->minimum_io_size = + nla_get_u32(info->attrs[NBD_ATTR_BLOCK_SIZE_MIN]); + if (info->attrs[NBD_ATTR_BLOCK_SIZE_OPT]) + config->optimal_io_size = + nla_get_u32(info->attrs[NBD_ATTR_BLOCK_SIZE_OPT]); if (info->attrs[NBD_ATTR_SOCKETS]) { struct nlattr *attr; int rem, fd; diff --git a/include/uapi/linux/nbd-netlink.h b/include/uapi/linux/nbd-netlink.h index 2d0b90964227..1d6621487560 100644 --- a/include/uapi/linux/nbd-netlink.h +++ b/include/uapi/linux/nbd-netlink.h @@ -36,6 +36,8 @@ enum { NBD_ATTR_DEAD_CONN_TIMEOUT, NBD_ATTR_DEVICE_LIST, NBD_ATTR_BACKEND_IDENTIFIER, + NBD_ATTR_BLOCK_SIZE_MIN, + NBD_ATTR_BLOCK_SIZE_OPT, __NBD_ATTR_MAX, }; #define NBD_ATTR_MAX (__NBD_ATTR_MAX - 1) -- 2.35.1
