openzfs · tonyhutter · Dec 28, 2023
diff --git a/cmd/zpool/zpool_vdev.c b/cmd/zpool/zpool_vdev.c
@@ -480,13 +480,43 @@ is_raidz_draid(replication_level_t *a, replication_level_t *b)
 	return (B_FALSE);
 }
 
+/*
+ * Return true if 'props' contains either:
+ *
+ *     feature@allow_backup_to_pool=disabled
+ *
+ * or
+ *
+ *     backup_alloc_class_to_pool=off
+ */
+static boolean_t
+is_backup_to_pool_disabled_in_props(nvlist_t *props)
+{
+	const char *str = NULL;
+	if (nvlist_lookup_string(props, "feature@allow_backup_to_pool",
+	    &str) == 0) {
+		if ((str != NULL) && strcmp(str, "disabled") == 0) {
+			return (B_TRUE);	/* It is disabled */
+		}
+	}
+
+	if (nvlist_lookup_string(props, "backup_alloc_class_to_pool",
+	    &str) == 0) {
+		if ((str != NULL) && strcmp(str, "off") == 0) {
+			return (B_TRUE);	/* It is disabled */
+		}
+	}
+
+	return (B_FALSE);
+}
+
 /*
  * Given a list of toplevel vdevs, return the current replication level.  If
  * the config is inconsistent, then NULL is returned.  If 'fatal' is set, then
  * an error message will be displayed for each self-inconsistent vdev.
  */
 static replication_level_t *
-get_replication(nvlist_t *nvroot, boolean_t fatal)
+get_replication(nvlist_t *props, nvlist_t *nvroot, boolean_t fatal)
 {
 	nvlist_t **top;
 	uint_t t, toplevels;
@@ -507,6 +537,7 @@ get_replication(nvlist_t *nvroot, boolean_t fatal)
 
 	for (t = 0; t < toplevels; t++) {
 		uint64_t is_log = B_FALSE;
+		const char *str = NULL;
 
 		nv = top[t];
 
@@ -518,6 +549,21 @@ get_replication(nvlist_t *nvroot, boolean_t fatal)
 		if (is_log)
 			continue;
 
+		/*
+		 * By default, all alloc class devices have their backup to pool
+		 * props enabled, so their replication level doesn't matter.
+		 * However, if they're disabled for any reason, then we do need
+		 * to force redundancy.
+		 */
+		(void) nvlist_lookup_string(nv, ZPOOL_CONFIG_ALLOCATION_BIAS,
+		    &str);
+		if (str &&
+		    ((strcmp(str, VDEV_ALLOC_BIAS_SPECIAL) == 0) ||
+		    (strcmp(str, VDEV_ALLOC_BIAS_DEDUP) == 0))) {
+			if (!is_backup_to_pool_disabled_in_props(props))
+				continue; /* We're backed up, skip redundancy */
+		}
+
 		/*
 		 * Ignore holes introduced by removing aux devices, along
 		 * with indirect vdevs introduced by previously removed
@@ -808,7 +854,7 @@ get_replication(nvlist_t *nvroot, boolean_t fatal)
  * report any difference between the two.
  */
 static int
-check_replication(nvlist_t *config, nvlist_t *newroot)
+check_replication(nvlist_t *props, nvlist_t *config, nvlist_t *newroot)
 {
 	nvlist_t **child;
 	uint_t	children;
@@ -825,7 +871,7 @@ check_replication(nvlist_t *config, nvlist_t *newroot)
 
 		verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
 		    &nvroot) == 0);
-		if ((current = get_replication(nvroot, B_FALSE)) == NULL)
+		if ((current = get_replication(props, nvroot, B_FALSE)) == NULL)
 			return (0);
 	}
 	/*
@@ -850,7 +896,7 @@ check_replication(nvlist_t *config, nvlist_t *newroot)
 	 * Get the replication level of the new vdev spec, reporting any
 	 * inconsistencies found.
 	 */
-	if ((new = get_replication(newroot, B_TRUE)) == NULL) {
+	if ((new = get_replication(props, newroot, B_TRUE)) == NULL) {
 		free(current);
 		return (-1);
 	}
@@ -1888,7 +1934,7 @@ make_root_vdev(zpool_handle_t *zhp, nvlist_t *props, int force, int check_rep,
 	 * found.  We include the existing pool spec, if any, as we need to
 	 * catch changes against the existing replication level.
 	 */
-	if (check_rep && check_replication(poolconfig, newroot) != 0) {
+	if (check_rep && check_replication(props, poolconfig, newroot) != 0) {
 		nvlist_free(newroot);
 		return (NULL);
 	}

diff --git a/include/sys/fs/zfs.h b/include/sys/fs/zfs.h
@@ -258,6 +258,7 @@ typedef enum {
 	ZPOOL_PROP_BCLONEUSED,
 	ZPOOL_PROP_BCLONESAVED,
 	ZPOOL_PROP_BCLONERATIO,
+	ZPOOL_PROP_BACKUP_ALLOC_CLASS_TO_POOL,
 	ZPOOL_NUM_PROPS
 } zpool_prop_t;
 
@@ -368,6 +369,7 @@ typedef enum {
 	VDEV_PROP_RAIDZ_EXPANDING,
 	VDEV_PROP_SLOW_IO_N,
 	VDEV_PROP_SLOW_IO_T,
+	VDEV_PROP_BACKUP_TO_POOL,
 	VDEV_NUM_PROPS
 } vdev_prop_t;
 
@@ -845,6 +847,7 @@ typedef struct zpool_load_policy {
 #define	ZPOOL_CONFIG_EXPANSION_TIME	"expansion_time"	/* not stored */
 #define	ZPOOL_CONFIG_REBUILD_STATS	"org.openzfs:rebuild_stats"
 #define	ZPOOL_CONFIG_COMPATIBILITY	"compatibility"
+#define	ZPOOL_CONFIG_BACKUP_TO_POOL	"backup_to_pool"
 
 /*
  * The persistent vdev state is stored as separate values rather than a single
@@ -1604,6 +1607,7 @@ typedef enum {
 	ZFS_ERR_CRYPTO_NOTSUP,
 	ZFS_ERR_RAIDZ_EXPAND_IN_PROGRESS,
 	ZFS_ERR_ASHIFT_MISMATCH,
+	ZFS_ERR_BACKUP_DISABLED_BUT_REQUESTED,
 } zfs_errno_t;
 
 /*

diff --git a/include/sys/spa.h b/include/sys/spa.h
@@ -1113,7 +1113,8 @@ extern boolean_t spa_remap_blkptr(spa_t *spa, blkptr_t *bp,
 extern uint64_t spa_get_last_removal_txg(spa_t *spa);
 extern boolean_t spa_trust_config(spa_t *spa);
 extern uint64_t spa_missing_tvds_allowed(spa_t *spa);
-extern void spa_set_missing_tvds(spa_t *spa, uint64_t missing);
+extern void spa_set_missing_tvds(spa_t *spa, uint64_t missing,
+    uint64_t missing_special);
 extern boolean_t spa_top_vdevs_spacemap_addressable(spa_t *spa);
 extern uint64_t spa_total_metaslabs(spa_t *spa);
 extern boolean_t spa_multihost(spa_t *spa);

diff --git a/include/sys/spa_impl.h b/include/sys/spa_impl.h
@@ -327,6 +327,12 @@ struct spa {
 	uint64_t	spa_missing_tvds;	/* unopenable tvds on load */
 	uint64_t	spa_missing_tvds_allowed; /* allow loading spa? */
 
+	/*
+	 * number of 'spa_missing_tvds' that are alloc class devices
+	 * backed up to the pool, and thus recoverable from errors.
+	 */
+	uint64_t	spa_missing_recovered_tvds;
+
 	uint64_t	spa_nonallocating_dspace;
 	spa_removing_phys_t spa_removing_phys;
 	spa_vdev_removal_t *spa_vdev_removal;
@@ -465,6 +471,9 @@ struct spa {
 	 */
 	spa_config_lock_t spa_config_lock[SCL_LOCKS]; /* config changes */
 	zfs_refcount_t	spa_refcount;		/* number of opens */
+
+	/* Backup special/dedup devices data to the pool */
+	boolean_t	spa_backup_alloc_class;
 };
 
 extern char *spa_config_path;

diff --git a/include/sys/vdev.h b/include/sys/vdev.h
@@ -172,6 +172,24 @@ extern uint32_t vdev_queue_length(vdev_t *vd);
 extern uint64_t vdev_queue_last_offset(vdev_t *vd);
 extern uint64_t vdev_queue_class_length(vdev_t *vq, zio_priority_t p);
 
+typedef enum {
+	/* (special flag) dry-run, get count only */
+	VDEV_ARRAY_COUNT = 1ULL << 0,
+
+	VDEV_ARRAY_ANY_LEAF = 1ULL << 1, /* match any leaf */
+	VDEV_ARRAY_SPECIAL_LEAF = 1ULL << 2, /* match special vdev leaves */
+	VDEV_ARRAY_DEDUP_LEAF = 1ULL << 3, /* match dedup vdev leaves */
+} vdev_array_flag_t;
+
+struct vdev_array
+{
+	vdev_t **vds; /* Array of vdev_t's */
+	int count;
+};
+
+extern struct vdev_array *vdev_array_alloc(vdev_t *rvd, uint64_t flags);
+extern void vdev_array_free(struct vdev_array *vda);
+
 extern void vdev_config_dirty(vdev_t *vd);
 extern void vdev_config_clean(vdev_t *vd);
 extern int vdev_config_sync(vdev_t **svd, int svdcount, uint64_t txg);

diff --git a/include/sys/vdev_impl.h b/include/sys/vdev_impl.h
@@ -284,6 +284,13 @@ struct vdev {
 	uint64_t	vdev_failfast;	/* device failfast setting	*/
 	boolean_t	vdev_rz_expanding; /* raidz is being expanded?	*/
 	boolean_t	vdev_ishole;	/* is a hole in the namespace	*/
+
+	/*
+	 * If this is set to true, then all the data on this vdev is backed up
+	 * to the pool.  This is only used by allocation class devices.
+	 */
+	boolean_t	vdev_backup_to_pool;
+
 	uint64_t	vdev_top_zap;
 	vdev_alloc_bias_t vdev_alloc_bias; /* metaslab allocation bias	*/
 
@@ -641,6 +648,11 @@ extern int vdev_obsolete_counts_are_precise(vdev_t *vd, boolean_t *are_precise);
 int vdev_checkpoint_sm_object(vdev_t *vd, uint64_t *sm_obj);
 void vdev_metaslab_group_create(vdev_t *vd);
 uint64_t vdev_best_ashift(uint64_t logical, uint64_t a, uint64_t b);
+extern boolean_t vdev_is_fully_backed_up(vdev_t *vd);
+extern boolean_t vdev_is_leaf(vdev_t *vd);
+extern boolean_t vdev_is_special(vdev_t *vd);
+extern boolean_t vdev_is_dedup(vdev_t *vd);
+extern boolean_t vdev_is_alloc_class(vdev_t *vd);
 
 /*
  * Vdev ashift optimization tunables

diff --git a/include/zfeature_common.h b/include/zfeature_common.h
@@ -82,6 +82,7 @@ typedef enum spa_feature {
 	SPA_FEATURE_AVZ_V2,
 	SPA_FEATURE_REDACTION_LIST_SPILL,
 	SPA_FEATURE_RAIDZ_EXPANSION,
+	SPA_FEATURE_ALLOW_BACKUP_TO_POOL,
 	SPA_FEATURES
 } spa_feature_t;
 

diff --git a/lib/libnvpair/libnvpair.abi b/lib/libnvpair/libnvpair.abi
@@ -1156,6 +1156,11 @@
       <parameter type-id='80f4b756'/>
       <return type-id='95e97e5e'/>
     </function-decl>
+    <function-decl name='strchr' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='80f4b756'/>
+      <parameter type-id='95e97e5e'/>
+      <return type-id='26a90f95'/>
+    </function-decl>
     <function-decl name='strcspn' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
       <parameter type-id='80f4b756'/>
@@ -2536,11 +2541,6 @@
       <parameter type-id='b59d7dce'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='strchr' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='80f4b756'/>
-      <parameter type-id='95e97e5e'/>
-      <return type-id='26a90f95'/>
-    </function-decl>
     <function-decl name='strlen' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
       <return type-id='b59d7dce'/>

diff --git a/lib/libuutil/libuutil.abi b/lib/libuutil/libuutil.abi
@@ -596,14 +596,11 @@
         <var-decl name='prev' type-id='b03eadb4' visibility='default'/>
       </data-member>
     </class-decl>
-    <class-decl name='list' size-in-bits='256' is-struct='yes' visibility='default' id='e824dae9'>
+    <class-decl name='list' size-in-bits='192' is-struct='yes' visibility='default' id='e824dae9'>
       <data-member access='public' layout-offset-in-bits='0'>
-        <var-decl name='list_size' type-id='b59d7dce' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='64'>
         <var-decl name='list_offset' type-id='b59d7dce' visibility='default'/>
       </data-member>
-      <data-member access='public' layout-offset-in-bits='128'>
+      <data-member access='public' layout-offset-in-bits='64'>
         <var-decl name='list_head' type-id='b0b5e45e' visibility='default'/>
       </data-member>
     </class-decl>
@@ -800,9 +797,16 @@
     <type-decl name='unsigned long int' size-in-bits='64' id='7359adad'/>
   </abi-instr>
   <abi-instr address-size='64' path='lib/libspl/os/linux/getmntany.c' language='LANG_C99'>
+    <array-type-def dimensions='1' type-id='38b51b3c' size-in-bits='832' id='02b72c00'>
+      <subrange length='13' type-id='7359adad' id='487fded1'/>
+    </array-type-def>
     <array-type-def dimensions='1' type-id='03085adc' size-in-bits='192' id='083f8d58'>
       <subrange length='3' type-id='7359adad' id='56f209d2'/>
     </array-type-def>
+    <class-decl name='__locale_data' is-struct='yes' visibility='default' is-declaration-only='yes' id='23de8b96'/>
+    <array-type-def dimensions='1' type-id='80f4b756' size-in-bits='832' id='39e6f84a'>
+      <subrange length='13' type-id='7359adad' id='487fded1'/>
+    </array-type-def>
     <class-decl name='mnttab' size-in-bits='256' is-struct='yes' visibility='default' id='1b055409'>
       <data-member access='public' layout-offset-in-bits='0'>
         <var-decl name='mnt_special' type-id='26a90f95' visibility='default'/>
@@ -912,6 +916,25 @@
     <typedef-decl name='__blksize_t' type-id='bd54fe1a' id='d3f10a7f'/>
     <typedef-decl name='__blkcnt64_t' type-id='bd54fe1a' id='4e711bf1'/>
     <typedef-decl name='__syscall_slong_t' type-id='bd54fe1a' id='03085adc'/>
+    <class-decl name='__locale_struct' size-in-bits='1856' is-struct='yes' visibility='default' id='90cc1ce3'>
+      <data-member access='public' layout-offset-in-bits='0'>
+        <var-decl name='__locales' type-id='02b72c00' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='832'>
+        <var-decl name='__ctype_b' type-id='31347b7a' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='896'>
+        <var-decl name='__ctype_tolower' type-id='6d60f45d' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='960'>
+        <var-decl name='__ctype_toupper' type-id='6d60f45d' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='1024'>
+        <var-decl name='__names' type-id='39e6f84a' visibility='default'/>
+      </data-member>
+    </class-decl>
+    <typedef-decl name='__locale_t' type-id='f01e1813' id='b7ac9b5f'/>
+    <typedef-decl name='locale_t' type-id='b7ac9b5f' id='973a4f8d'/>
     <class-decl name='timespec' size-in-bits='128' is-struct='yes' visibility='default' id='a9c79a1f'>
       <data-member access='public' layout-offset-in-bits='0'>
         <var-decl name='tv_sec' type-id='65eda9c0' visibility='default'/>
@@ -920,12 +943,23 @@
         <var-decl name='tv_nsec' type-id='03085adc' visibility='default'/>
       </data-member>
     </class-decl>
+    <pointer-type-def type-id='23de8b96' size-in-bits='64' id='38b51b3c'/>
+    <pointer-type-def type-id='90cc1ce3' size-in-bits='64' id='f01e1813'/>
+    <qualified-type-def type-id='95e97e5e' const='yes' id='2448a865'/>
+    <pointer-type-def type-id='2448a865' size-in-bits='64' id='6d60f45d'/>
+    <qualified-type-def type-id='8efea9e5' const='yes' id='3beb2af4'/>
+    <pointer-type-def type-id='3beb2af4' size-in-bits='64' id='31347b7a'/>
     <pointer-type-def type-id='0c544dc0' size-in-bits='64' id='394fc496'/>
     <pointer-type-def type-id='56fe4a37' size-in-bits='64' id='b6b61d2f'/>
     <qualified-type-def type-id='b6b61d2f' restrict='yes' id='3cad23cd'/>
     <pointer-type-def type-id='1b055409' size-in-bits='64' id='9d424d31'/>
     <pointer-type-def type-id='0bbec9cd' size-in-bits='64' id='62f7a03d'/>
     <qualified-type-def type-id='62f7a03d' restrict='yes' id='f1cadedf'/>
+    <class-decl name='__locale_data' is-struct='yes' visibility='default' is-declaration-only='yes' id='23de8b96'/>
+    <function-decl name='uselocale' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='973a4f8d'/>
+      <return type-id='973a4f8d'/>
+    </function-decl>
     <function-decl name='getmntent_r' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='e75a27e9'/>
       <parameter type-id='3cad23cd'/>
@@ -937,8 +971,9 @@
       <parameter type-id='822cd80b'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='strerror' visibility='default' binding='global' size-in-bits='64'>
+    <function-decl name='strerror_l' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='95e97e5e'/>
+      <parameter type-id='973a4f8d'/>
       <return type-id='26a90f95'/>
     </function-decl>
     <function-decl name='__fprintf_chk' visibility='default' binding='global' size-in-bits='64'>