Merge patch series "add ioctl to query metadata and protection info capabilities"

Anuj Gupta <anuj20.g@samsung.com> says:

This patch series adds a new ioctl to query metadata and integrity
capability.

* patches from https://lore.kernel.org/20250630090548.3317-1-anuj20.g@samsung.com:
  fs: add ioctl to query metadata and protection info capabilities
  nvme: set pi_offset only when checksum type is not BLK_INTEGRITY_CSUM_NONE
  block: introduce pi_tuple_size field in blk_integrity
  block: rename tuple_size field in blk_integrity to metadata_size

Link: https://lore.kernel.org/20250630090548.3317-1-anuj20.g@samsung.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

1 files changed, 53 insertions, 1 deletions

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index e4e2567061f9..9d9dc9c32083 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -13,6 +13,7 @@
 #include <linux/scatterlist.h>
 #include <linux/export.h>
 #include <linux/slab.h>
+#include <linux/t10-pi.h>
 
 #include "blk.h"
 
@@ -54,6 +55,57 @@ new_segment:
 	return segments;
 }
 
+int blk_get_meta_cap(struct block_device *bdev, unsigned int cmd,
+		     struct logical_block_metadata_cap __user *argp)
+{
+	struct blk_integrity *bi = blk_get_integrity(bdev->bd_disk);
+	struct logical_block_metadata_cap meta_cap = {};
+	size_t usize = _IOC_SIZE(cmd);
+
+	if (!argp)
+		return -EINVAL;
+	if (usize < LBMD_SIZE_VER0)
+		return -EINVAL;
+	if (!bi)
+		goto out;
+
+	if (bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE)
+		meta_cap.lbmd_flags |= LBMD_PI_CAP_INTEGRITY;
+	if (bi->flags & BLK_INTEGRITY_REF_TAG)
+		meta_cap.lbmd_flags |= LBMD_PI_CAP_REFTAG;
+	meta_cap.lbmd_interval = 1 << bi->interval_exp;
+	meta_cap.lbmd_size = bi->metadata_size;
+	meta_cap.lbmd_pi_size = bi->pi_tuple_size;
+	meta_cap.lbmd_pi_offset = bi->pi_offset;
+	meta_cap.lbmd_opaque_size = bi->metadata_size - bi->pi_tuple_size;
+	if (meta_cap.lbmd_opaque_size && !bi->pi_offset)
+		meta_cap.lbmd_opaque_offset = bi->pi_tuple_size;
+
+	meta_cap.lbmd_guard_tag_type = bi->csum_type;
+	if (bi->csum_type != BLK_INTEGRITY_CSUM_NONE)
+		meta_cap.lbmd_app_tag_size = 2;
+
+	if (bi->flags & BLK_INTEGRITY_REF_TAG) {
+		switch (bi->csum_type) {
+		case BLK_INTEGRITY_CSUM_CRC64:
+			meta_cap.lbmd_ref_tag_size =
+				sizeof_field(struct crc64_pi_tuple, ref_tag);
+			break;
+		case BLK_INTEGRITY_CSUM_CRC:
+		case BLK_INTEGRITY_CSUM_IP:
+			meta_cap.lbmd_ref_tag_size =
+				sizeof_field(struct t10_pi_tuple, ref_tag);
+			break;
+		default:
+			break;
+		}
+	}
+
+out:
+	return copy_struct_to_user(argp, usize, &meta_cap, sizeof(meta_cap),
+				   NULL);
+}
+
 /**
  * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
  * @rq:		request to map
@@ -239,7 +291,7 @@ static ssize_t format_show(struct device *dev, struct device_attribute *attr,
 {
 	struct blk_integrity *bi = dev_to_bi(dev);
 
-	if (!bi->tuple_size)
+	if (!bi->metadata_size)
 		return sysfs_emit(page, "none\n");
 	return sysfs_emit(page, "%s\n", blk_integrity_profile_name(bi));
 }