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, 77 insertions, 0 deletions

diff --git a/include/net/calipso.h b/include/net/calipso.h
new file mode 100644
index 000000000..76b9e08c1
--- /dev/null
+++ b/include/net/calipso.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * CALIPSO - Common Architecture Label IPv6 Security Option
+ *
+ * This is an implementation of the CALIPSO protocol as specified in
+ * RFC 5570.
+ *
+ * Authors: Paul Moore <paul@paul-moore.com>
+ *          Huw Davies <huw@codeweavers.com>
+ */
+
+/*
+ * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
+ * (c) Copyright Huw Davies <huw@codeweavers.com>, 2015
+ */
+
+#ifndef _CALIPSO_H
+#define _CALIPSO_H
+
+#include <linux/types.h>
+#include <linux/rcupdate.h>
+#include <linux/list.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <net/netlabel.h>
+#include <net/request_sock.h>
+#include <linux/refcount.h>
+#include <linux/unaligned.h>
+
+/* known doi values */
+#define CALIPSO_DOI_UNKNOWN          0x00000000
+
+/* doi mapping types */
+#define CALIPSO_MAP_UNKNOWN          0
+#define CALIPSO_MAP_PASS             2
+
+/*
+ * CALIPSO DOI definitions
+ */
+
+/* DOI definition struct */
+struct calipso_doi {
+	u32 doi;
+	u32 type;
+
+	refcount_t refcount;
+	struct list_head list;
+	struct rcu_head rcu;
+};
+
+/*
+ * Sysctl Variables
+ */
+extern int calipso_cache_enabled;
+extern int calipso_cache_bucketsize;
+
+#ifdef CONFIG_NETLABEL
+int __init calipso_init(void);
+void calipso_exit(void);
+bool calipso_validate(const struct sk_buff *skb, const unsigned char *option);
+#else
+static inline int __init calipso_init(void)
+{
+	return 0;
+}
+
+static inline void calipso_exit(void)
+{
+}
+static inline bool calipso_validate(const struct sk_buff *skb,
+				    const unsigned char *option)
+{
+	return true;
+}
+#endif /* CONFIG_NETLABEL */
+
+#endif /* _CALIPSO_H */