virtio_blk: set the zone write granularitygrafted

virtblk_read_zoned_limits() reads the write granularity that the device
reports in virtio_blk_zoned_characteristics and assigns it to the
physical block size and to io_min, but never to the limit that is named
after it. queue_limits.zone_write_granularity is left at zero, so
blk_validate_zoned_limits() raises it to the logical block size:

	if (lim->zone_write_granularity < lim->logical_block_size)
		lim->zone_write_granularity = lim->logical_block_size;

A device that reports a granularity coarser than its logical block size,
which is what the field exists to express, therefore has it silently
reduced. A 512e host managed disk passed through to a guest reports a
logical block size of 512 and a write granularity of 4096, and the guest
ends up with a zone write granularity of 512.

bio_split_alignment() returns lim->zone_write_granularity if it is non-zero
and bio_split_io_at() may split a bio with as per bio_split_alignment().
This can real to the write getting rejected by the host drive, as the write
is not aligned to the physical block size.

zonefs also takes its block size from bdev_zone_write_granularity(), so it
would incorrectly use 512 on a disk that requires 4096.

sd_zbc_read_zones() sets the limit from the physical block size for the
same reason. NVMe ZNS and null_blk leave it unset, but the fallback
gives the right answer for them, as their write granularity is the
logical block size. virtio carries a separate value that may exceed it.

Set the zone write granularity from the value that the device reports.

Fixes: 95bfec41bd3d ("virtio-blk: add support for zoned block devices")
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Link: https://patch.msgid.link/20260918140641.2031075-2-cassel@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 264 insertions, 0 deletions

diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
new file mode 100644
index 000000000..2bff41aac
--- /dev/null
+++ b/include/net/rtnetlink.h
@@ -0,0 +1,264 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NET_RTNETLINK_H
+#define __NET_RTNETLINK_H
+
+#include <linux/rtnetlink.h>
+#include <linux/srcu.h>
+#include <net/netlink.h>
+
+typedef int (*rtnl_doit_func)(struct sk_buff *, struct nlmsghdr *,
+			      struct netlink_ext_ack *);
+typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *);
+
+enum rtnl_link_flags {
+	RTNL_FLAG_DOIT_UNLOCKED		= BIT(0),
+#define RTNL_FLAG_DOIT_PERNET		RTNL_FLAG_DOIT_UNLOCKED
+#define RTNL_FLAG_DOIT_PERNET_WIP	RTNL_FLAG_DOIT_UNLOCKED
+	RTNL_FLAG_BULK_DEL_SUPPORTED	= BIT(1),
+	RTNL_FLAG_DUMP_UNLOCKED		= BIT(2),
+	RTNL_FLAG_DUMP_SPLIT_NLM_DONE	= BIT(3),	/* legacy behavior */
+};
+
+enum rtnl_kinds {
+	RTNL_KIND_NEW,
+	RTNL_KIND_DEL,
+	RTNL_KIND_GET,
+	RTNL_KIND_SET
+};
+#define RTNL_KIND_MASK 0x3
+
+static inline enum rtnl_kinds rtnl_msgtype_kind(int msgtype)
+{
+	return msgtype & RTNL_KIND_MASK;
+}
+
+/**
+ *	struct rtnl_msg_handler - rtnetlink message type and handlers
+ *
+ *	@owner: NULL for built-in, THIS_MODULE for module
+ *	@protocol: Protocol family or PF_UNSPEC
+ *	@msgtype: rtnetlink message type
+ *	@doit: Function pointer called for each request message
+ *	@dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
+ *	@flags: rtnl_link_flags to modify behaviour of doit/dumpit functions
+ */
+struct rtnl_msg_handler {
+	struct module *owner;
+	int protocol;
+	int msgtype;
+	rtnl_doit_func doit;
+	rtnl_dumpit_func dumpit;
+	int flags;
+};
+
+void rtnl_unregister_all(int protocol);
+
+int __rtnl_register_many(const struct rtnl_msg_handler *handlers, int n);
+void __rtnl_unregister_many(const struct rtnl_msg_handler *handlers, int n);
+
+#define rtnl_register_many(handlers)				\
+	__rtnl_register_many(handlers, ARRAY_SIZE(handlers))
+#define rtnl_unregister_many(handlers)				\
+	__rtnl_unregister_many(handlers, ARRAY_SIZE(handlers))
+
+static inline int rtnl_msg_family(const struct nlmsghdr *nlh)
+{
+	if (nlmsg_len(nlh) >= sizeof(struct rtgenmsg))
+		return ((struct rtgenmsg *) nlmsg_data(nlh))->rtgen_family;
+	else
+		return AF_UNSPEC;
+}
+
+/**
+ * struct rtnl_newlink_params - parameters of rtnl_link_ops::newlink()
+ *
+ * @src_net: Source netns of rtnetlink socket
+ * @link_net: Link netns by IFLA_LINK_NETNSID, NULL if not specified
+ * @peer_net: Peer netns
+ * @tb: IFLA_* attributes
+ * @data: IFLA_INFO_DATA attributes
+ */
+struct rtnl_newlink_params {
+	struct net *src_net;
+	struct net *link_net;
+	struct net *peer_net;
+	struct nlattr **tb;
+	struct nlattr **data;
+};
+
+/* Get effective link netns from newlink params. Generally, this is link_net
+ * and falls back to src_net. But for compatibility, a driver may * choose to
+ * use dev_net(dev) instead.
+ */
+static inline struct net *rtnl_newlink_link_net(struct rtnl_newlink_params *p)
+{
+	return p->link_net ? : p->src_net;
+}
+
+/* Get peer netns from newlink params. Fallback to link netns if peer netns is
+ * not specified explicitly.
+ */
+static inline struct net *rtnl_newlink_peer_net(struct rtnl_newlink_params *p)
+{
+	return p->peer_net ? : rtnl_newlink_link_net(p);
+}
+
+/**
+ *	struct rtnl_link_ops - rtnetlink link operations
+ *
+ *	@list: Used internally, protected by link_ops_mutex and SRCU
+ *	@srcu: Used internally
+ *	@kind: Identifier
+ *	@netns_refund: Physical device, move to init_net on netns exit
+ *	@peer_type: Peer device specific netlink attribute number (e.g. VETH_INFO_PEER)
+ *	@maxtype: Highest device specific netlink attribute number
+ *	@policy: Netlink policy for device specific attribute validation
+ *	@validate: Optional validation function for netlink/changelink parameters
+ *	@alloc: netdev allocation function, can be %NULL and is then used
+ *		in place of alloc_netdev_mqs(), in this case @priv_size
+ *		and @setup are unused. Returns a netdev or ERR_PTR().
+ *	@priv_size: sizeof net_device private space
+ *	@setup: net_device setup function
+ *	@newlink: Function for configuring and registering a new device
+ *	@changelink: Function for changing parameters of an existing device
+ *	@dellink: Function to remove a device
+ *	@get_size: Function to calculate required room for dumping device
+ *		   specific netlink attributes
+ *	@fill_info: Function to dump device specific netlink attributes
+ *	@get_xstats_size: Function to calculate required room for dumping device
+ *			  specific statistics
+ *	@fill_xstats: Function to dump device specific statistics
+ *	@get_num_tx_queues: Function to determine number of transmit queues
+ *			    to create when creating a new device.
+ *	@get_num_rx_queues: Function to determine number of receive queues
+ *			    to create when creating a new device.
+ *	@get_link_net: Function to get the i/o netns of the device
+ *	@get_linkxstats_size: Function to calculate the required room for
+ *			      dumping device-specific extended link stats
+ *	@fill_linkxstats: Function to dump device-specific extended link stats
+ */
+struct rtnl_link_ops {
+	struct list_head	list;
+	struct srcu_struct	srcu;
+
+	const char		*kind;
+
+	size_t			priv_size;
+	struct net_device	*(*alloc)(struct nlattr *tb[],
+					  const char *ifname,
+					  unsigned char name_assign_type,
+					  unsigned int num_tx_queues,
+					  unsigned int num_rx_queues);
+	void			(*setup)(struct net_device *dev);
+
+	bool			netns_refund;
+	const u16		peer_type;
+	unsigned int		maxtype;
+	const struct nla_policy	*policy;
+	int			(*validate)(struct nlattr *tb[],
+					    struct nlattr *data[],
+					    struct netlink_ext_ack *extack);
+
+	int			(*newlink)(struct net_device *dev,
+					   struct rtnl_newlink_params *params,
+					   struct netlink_ext_ack *extack);
+	int			(*changelink)(struct net_device *dev,
+					      struct nlattr *tb[],
+					      struct nlattr *data[],
+					      struct netlink_ext_ack *extack);
+	void			(*dellink)(struct net_device *dev,
+					   struct list_head *head);
+
+	size_t			(*get_size)(const struct net_device *dev);
+	int			(*fill_info)(struct sk_buff *skb,
+					     const struct net_device *dev);
+
+	size_t			(*get_xstats_size)(const struct net_device *dev);
+	int			(*fill_xstats)(struct sk_buff *skb,
+					       const struct net_device *dev);
+	unsigned int		(*get_num_tx_queues)(void);
+	unsigned int		(*get_num_rx_queues)(void);
+
+	unsigned int		slave_maxtype;
+	const struct nla_policy	*slave_policy;
+	int			(*slave_changelink)(struct net_device *dev,
+						    struct net_device *slave_dev,
+						    struct nlattr *tb[],
+						    struct nlattr *data[],
+						    struct netlink_ext_ack *extack);
+	size_t			(*get_slave_size)(const struct net_device *dev,
+						  const struct net_device *slave_dev);
+	int			(*fill_slave_info)(struct sk_buff *skb,
+						   const struct net_device *dev,
+						   const struct net_device *slave_dev);
+	struct net		*(*get_link_net)(const struct net_device *dev);
+	size_t			(*get_linkxstats_size)(const struct net_device *dev,
+						       int attr);
+	int			(*fill_linkxstats)(struct sk_buff *skb,
+						   const struct net_device *dev,
+						   int *prividx, int attr);
+};
+
+int rtnl_link_register(struct rtnl_link_ops *ops);
+void rtnl_link_unregister(struct rtnl_link_ops *ops);
+
+/**
+ * 	struct rtnl_af_ops - rtnetlink address family operations
+ *
+ *	@list: Used internally, protected by RTNL and SRCU
+ *	@srcu: Used internally
+ * 	@family: Address family
+ * 	@fill_link_af: Function to fill IFLA_AF_SPEC with address family
+ * 		       specific netlink attributes.
+ * 	@get_link_af_size: Function to calculate size of address family specific
+ * 			   netlink attributes.
+ *	@validate_link_af: Validate a IFLA_AF_SPEC attribute, must check attr
+ *			   for invalid configuration settings.
+ * 	@set_link_af: Function to parse a IFLA_AF_SPEC attribute and modify
+ *		      net_device accordingly.
+ */
+struct rtnl_af_ops {
+	struct list_head	list;
+	struct srcu_struct	srcu;
+
+	int			family;
+
+	int			(*fill_link_af)(struct sk_buff *skb,
+						const struct net_device *dev,
+						u32 ext_filter_mask);
+	size_t			(*get_link_af_size)(const struct net_device *dev,
+						    u32 ext_filter_mask);
+
+	int			(*validate_link_af)(const struct net_device *dev,
+						    const struct nlattr *attr,
+						    struct netlink_ext_ack *extack);
+	int			(*set_link_af)(struct net_device *dev,
+					       const struct nlattr *attr,
+					       struct netlink_ext_ack *extack);
+	int			(*fill_stats_af)(struct sk_buff *skb,
+						 const struct net_device *dev);
+	size_t			(*get_stats_af_size)(const struct net_device *dev);
+};
+
+int rtnl_af_register(struct rtnl_af_ops *ops);
+void rtnl_af_unregister(struct rtnl_af_ops *ops);
+
+struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[]);
+struct net_device *rtnl_create_link(struct net *net, const char *ifname,
+				    unsigned char name_assign_type,
+				    const struct rtnl_link_ops *ops,
+				    struct nlattr *tb[],
+				    struct netlink_ext_ack *extack);
+int rtnl_delete_link(struct net_device *dev, u32 portid, const struct nlmsghdr *nlh);
+int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm,
+			u32 portid, const struct nlmsghdr *nlh);
+
+int rtnl_nla_parse_ifinfomsg(struct nlattr **tb, const struct nlattr *nla_peer,
+			     struct netlink_ext_ack *exterr);
+struct net *rtnl_get_net_ns_capable(struct sock *sk, int netnsid);
+bool rtnl_dev_link_net_capable(const struct net_device *dev,
+			       const struct net *link_net);
+
+#define MODULE_ALIAS_RTNL_LINK(kind) MODULE_ALIAS("rtnl-link-" kind)
+
+#endif