Illumos 4171, 4172

4171 clean up spa_feature_*() interfaces
4172 implement extensible_dataset feature for use by other zpool features

Reviewed by: Max Grossman <[email protected]>
Reviewed by: Christopher Siden <[email protected]>
Reviewed by: George Wilson <[email protected]>
Reviewed by: Jerry Jelinek <[email protected]>
Approved by: Garrett D'Amore <[email protected]>a

References:
  https://www.illumos.org/issues/4171
  https://www.illumos.org/issues/4172
  https://github.com/illumos/illumos-gate/commit/2acef22

Ported-by: Tim Chase <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #2528

1 files changed, 14 insertions, 11 deletions

diff --git a/include/zfeature_common.h b/include/zfeature_common.h
index f4c1088db..084153cb0 100644
--- a/include/zfeature_common.h
+++ b/include/zfeature_common.h
@@ -37,34 +37,37 @@ extern "C" {
 
 struct zfeature_info;
 
+typedef enum spa_feature {
+	SPA_FEATURE_NONE = -1,
+	SPA_FEATURE_ASYNC_DESTROY,
+	SPA_FEATURE_EMPTY_BPOBJ,
+	SPA_FEATURE_LZ4_COMPRESS,
+	SPA_FEATURE_SPACEMAP_HISTOGRAM,
+	SPA_FEATURE_EXTENSIBLE_DATASET,
+	SPA_FEATURES
+} spa_feature_t;
+
 typedef struct zfeature_info {
+	spa_feature_t fi_feature;
 	const char *fi_uname;	/* User-facing feature name */
 	const char *fi_guid;	/* On-disk feature identifier */
 	const char *fi_desc;	/* Feature description */
 	boolean_t fi_can_readonly; /* Can open pool readonly w/o support? */
 	boolean_t fi_mos;	/* Is the feature necessary to read the MOS? */
-	struct zfeature_info **fi_depends; /* array; null terminated */
+	/* array of dependencies, terminated by SPA_FEATURE_NONE */
+	const spa_feature_t *fi_depends;
 } zfeature_info_t;
 
 typedef int (zfeature_func_t)(zfeature_info_t *fi, void *arg);
 
 #define	ZFS_FEATURE_DEBUG
 
-typedef enum spa_feature {
-	SPA_FEATURE_ASYNC_DESTROY,
-	SPA_FEATURE_EMPTY_BPOBJ,
-	SPA_FEATURE_LZ4_COMPRESS,
-	SPA_FEATURE_SPACEMAP_HISTOGRAM,
-	SPA_FEATURES
-} spa_feature_t;
-
 extern zfeature_info_t spa_feature_table[SPA_FEATURES];
 
 extern boolean_t zfeature_is_valid_guid(const char *);
 
 extern boolean_t zfeature_is_supported(const char *);
-extern int zfeature_lookup_guid(const char *, zfeature_info_t **res);
-extern int zfeature_lookup_name(const char *, zfeature_info_t **res);
+extern int zfeature_lookup_name(const char *name, spa_feature_t *res);
 
 extern void zpool_feature_init(void);