block: add capacity field to zone descriptors

In the zoned storage model, the sectors within a zone are typically all writeable. With the introduction of the Zoned Namespace (ZNS) Command Set in the NVM Express organization, the model was extended to have a specific writeable capacity. Extend the zone descriptor data structure with a zone capacity field to indicate to the user how many sectors in a zone are writeable. Introduce backward compatibility in the zone report ioctl by extending the zone report header data structure with a flags field to indicate if the capacity field is available.

Matias Bjørling committed 6 years ago

Commit 82394db1 parent f5af5774 files · +17 −2Browse files

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include/uapi/linux/blkzoned.h+13−2

 	BLK_ZONE_COND_OFFLINE	= 0xF,
 };
+/**
+ * enum blk_zone_report_flags - Feature flags of reported zone descriptors.
+ *
+ * @BLK_ZONE_REP_CAPACITY: Zone descriptor has capacity field.
+ */
+enum blk_zone_report_flags {
+	BLK_ZONE_REP_CAPACITY	= (1 << 0),
+};
 /**
  * struct blk_zone - Zone descriptor for BLKREPORTZONE ioctl.
  *
 	__u8	cond;		/* Zone condition */
 	__u8	non_seq;	/* Non-sequential write resources active */
 	__u8	reset;		/* Reset write pointer recommended */
-	__u8	reserved[36];
+	__u8	resv[4];
+	__u64	capacity;	/* Zone capacity in number of sectors */
+	__u8	reserved[24];
 };
 /**
 struct blk_zone_report {
 	__u64		sector;
 	__u32		nr_zones;
-	__u8		reserved[4];
+	__u32		flags;
 	struct blk_zone zones[0];
 };