Merge branch 'issue-2094'

This patch stack was designed to accomplish the following:

* Cleanly address the pool incompatibility which was accidentally
  introduced post-0.6.2 but pre-0.6.3.  This required adding
  infrastructure which can be used from now on to notify system
  administrators of errata which affect their pool.

* Add additional automated regression testing to ensure this type
  of compatibility issue is caught prior to the change being merged.

Signed-off-by: Brian Behlendorf <[email protected]>
Closes #2094

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "scripts/zfs-images"]
+	path = scripts/zfs-images
+	url = https://github.com/zfsonlinux/zfs-images

cmd/zpool/zpool_main.c

@@ -1608,7 +1608,8 @@ show_import(nvlist_t *config)
 	uint64_t guid;
 	char *msgid;
 	nvlist_t *nvroot;
-	int reason;
+	zpool_status_t reason;
+	zpool_errata_t errata;
 	const char *health;
 	uint_t vsc;
 	int namewidth;
@@ -1627,7 +1628,7 @@ show_import(nvlist_t *config)
 	    (uint64_t **)&vs, &vsc) == 0);
 	health = zpool_state_to_name(vs->vs_state, vs->vs_aux);
 
-	reason = zpool_import_status(config, &msgid);
+	reason = zpool_import_status(config, &msgid, &errata);
 
 	(void) printf(gettext("   pool: %s\n"), name);
 	(void) printf(gettext("     id: %llu\n"), (u_longlong_t)guid);
@@ -1715,6 +1716,11 @@ show_import(nvlist_t *config)
 		    "resilvered.\n"));
 		break;
 
+	case ZPOOL_STATUS_ERRATA:
+		(void) printf(gettext(" status: Errata #%d detected.\n"),
+		    errata);
+		break;
+
 	default:
 		/*
 		 * No other status can be seen when importing pools.
@@ -1736,6 +1742,34 @@ show_import(nvlist_t *config)
 			(void) printf(gettext(" action: The pool can be "
 			    "imported using its name or numeric "
 			    "identifier and\n\tthe '-f' flag.\n"));
+		} else if (reason == ZPOOL_STATUS_ERRATA) {
+			switch (errata) {
+			case ZPOOL_ERRATA_NONE:
+				break;
+
+			case ZPOOL_ERRATA_ZOL_2094_SCRUB:
+				(void) printf(gettext(" action: The pool can "
+				    "be imported using its name or numeric "
+				    "identifier,\n\thowever there is a compat"
+				    "ibility issue which should be corrected"
+				    "\n\tby running 'zpool scrub'\n"));
+				break;
+
+			case ZPOOL_ERRATA_ZOL_2094_ASYNC_DESTROY:
+				(void) printf(gettext(" action: The pool can"
+				    "not be imported with this version of ZFS "
+				    "due to\n\tan active asynchronous destroy. "
+				    "Revert to an earlier version\n\tand "
+				    "allow the destroy to complete before "
+				    "updating.\n"));
+				break;
+
+			default:
+				/*
+				 * All errata must contain an action message.
+				 */
+				assert(0);
+			}
 		} else {
 			(void) printf(gettext(" action: The pool can be "
 			    "imported using its name or numeric "
@@ -4125,13 +4159,14 @@ status_callback(zpool_handle_t *zhp, void *data)
 	status_cbdata_t *cbp = data;
 	nvlist_t *config, *nvroot;
 	char *msgid;
-	int reason;
+	zpool_status_t reason;
+	zpool_errata_t errata;
 	const char *health;
 	uint_t c;
 	vdev_stat_t *vs;
 
 	config = zpool_get_config(zhp, NULL);
-	reason = zpool_get_status(zhp, &msgid);
+	reason = zpool_get_status(zhp, &msgid, &errata);
 
 	cbp->cb_count++;
 
@@ -4349,6 +4384,28 @@ status_callback(zpool_handle_t *zhp, void *data)
 		    "'zpool clear'.\n"));
 		break;
 
+	case ZPOOL_STATUS_ERRATA:
+		(void) printf(gettext("status: Errata #%d detected.\n"),
+		    errata);
+
+		switch (errata) {
+		case ZPOOL_ERRATA_NONE:
+			break;
+
+		case ZPOOL_ERRATA_ZOL_2094_SCRUB:
+			(void) printf(gettext("action: To correct the issue "
+			    "run 'zpool scrub'.\n"));
+			break;
+
+		default:
+			/*
+			 * All errata which allow the pool to be imported
+			 * must contain an action message.
+			 */
+			assert(0);
+		}
+		break;
+
 	default:
 		/*
 		 * The remaining errors can't actually be generated, yet.

include/libzfs.h

@@ -312,6 +312,7 @@ typedef enum {
 	ZPOOL_STATUS_IO_FAILURE_WAIT,	/* failed I/O, failmode 'wait' */
 	ZPOOL_STATUS_IO_FAILURE_CONTINUE, /* failed I/O, failmode 'continue' */
 	ZPOOL_STATUS_BAD_LOG,		/* cannot read log chain(s) */
+	ZPOOL_STATUS_ERRATA,		/* informational errata available */
 
 	/*
 	 * If the pool has unsupported features but can still be opened in
@@ -347,8 +348,10 @@ typedef enum {
 	ZPOOL_STATUS_OK
 } zpool_status_t;
 
-extern zpool_status_t zpool_get_status(zpool_handle_t *, char **);
-extern zpool_status_t zpool_import_status(nvlist_t *, char **);
+extern zpool_status_t zpool_get_status(zpool_handle_t *, char **,
+    zpool_errata_t *);
+extern zpool_status_t zpool_import_status(nvlist_t *, char **,
+    zpool_errata_t *);
 extern void zpool_dump_ddt(const ddt_stat_t *dds, const ddt_histogram_t *ddh);
 
 /*

include/sys/dsl_scan.h

@@ -72,6 +72,8 @@ typedef enum dsl_scan_flags {
 	DSF_VISIT_DS_AGAIN = 1<<0,
 } dsl_scan_flags_t;
 
+#define	DSL_SCAN_FLAGS_MASK (DSF_VISIT_DS_AGAIN)
+
 /*
  * Every pool will have one dsl_scan_t and this structure will contain
  * in-memory information about the scan and a pointer to the on-disk

include/sys/fs/zfs.h

@@ -548,6 +548,7 @@ typedef struct zpool_rewind_policy {
 #define	ZPOOL_CONFIG_CAN_RDONLY		"can_rdonly"	/* not stored on disk */
 #define	ZPOOL_CONFIG_FEATURES_FOR_READ	"features_for_read"
 #define	ZPOOL_CONFIG_FEATURE_STATS	"feature_stats"	/* not stored on disk */
+#define	ZPOOL_CONFIG_ERRATA		"errata"	/* not stored on disk */
 /*
  * The persistent vdev state is stored as separate values rather than a single
  * 'vdev_state' entry.  This is because a device can be in multiple states, such
@@ -704,6 +705,17 @@ typedef enum dsl_scan_state {
 	DSS_NUM_STATES
 } dsl_scan_state_t;
 
+/*
+ * Errata described by http://zfsonlinux.org/msg/ZFS-8000-ER.  The ordering
+ * of this enum must be maintained to ensure the errata identifiers map to
+ * the correct documentation.  New errata may only be appended to the list
+ * and must contain corresponding documentation at the above link.
+ */
+typedef enum zpool_errata {
+	ZPOOL_ERRATA_NONE,
+	ZPOOL_ERRATA_ZOL_2094_SCRUB,
+	ZPOOL_ERRATA_ZOL_2094_ASYNC_DESTROY,
+} zpool_errata_t;
 
 /*
  * Vdev statistics.  Note: all fields should be 64-bit because this

include/sys/spa_impl.h

@@ -236,6 +236,7 @@ struct spa {
 	uint64_t	spa_deadman_calls;	/* number of deadman calls */
 	hrtime_t	spa_sync_starttime;	/* starting time of spa_sync */
 	uint64_t	spa_deadman_synctime;	/* deadman expiration timer */
+	uint64_t	spa_errata;		/* errata issues detected */
 	spa_stats_t	spa_stats;		/* assorted spa statistics */
 
 	/*

include/sys/zio.h

@@ -260,7 +260,6 @@ struct zbookmark {
 	uint64_t	zb_object;
 	int64_t		zb_level;
 	uint64_t	zb_blkid;
-	char *		zb_func;
 };
 
 #define	SET_BOOKMARK(zb, objset, object, level, blkid)  \
@@ -269,7 +268,6 @@ struct zbookmark {
 	(zb)->zb_object = object;                       \
 	(zb)->zb_level = level;                         \
 	(zb)->zb_blkid = blkid;                         \
-	(zb)->zb_func = FTAG;                           \
 }
 
 #define	ZB_DESTROYED_OBJSET	(-1ULL)

lib/libzfs/libzfs_status.c

@@ -67,6 +67,7 @@ static char *zfs_msgid_table[] = {
 	"ZFS-8000-HC",
 	"ZFS-8000-JQ",
 	"ZFS-8000-K4",
+	"ZFS-8000-ER",
 };
 
 #define	NMSGID	(sizeof (zfs_msgid_table) / sizeof (zfs_msgid_table[0]))
@@ -182,7 +183,7 @@ find_vdev_problem(nvlist_t *vdev, int (*func)(uint64_t, uint64_t, uint64_t))
  * only picks the most damaging of all the current errors to report.
  */
 static zpool_status_t
-check_status(nvlist_t *config, boolean_t isimport)
+check_status(nvlist_t *config, boolean_t isimport, zpool_errata_t *erratap)
 {
 	nvlist_t *nvroot;
 	vdev_stat_t *vs;
@@ -193,6 +194,7 @@ check_status(nvlist_t *config, boolean_t isimport)
 	uint64_t stateval;
 	uint64_t suspended;
 	uint64_t hostid = 0;
+	uint64_t errata = 0;
 	unsigned long system_hostid = gethostid() & 0xffffffff;
 
 	verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
@@ -356,13 +358,22 @@ check_status(nvlist_t *config, boolean_t isimport)
 		}
 	}
 
+	/*
+	 * Informational errata available.
+	 */
+	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_ERRATA, &errata);
+	if (errata) {
+		*erratap = errata;
+		return (ZPOOL_STATUS_ERRATA);
+	}
+
 	return (ZPOOL_STATUS_OK);
 }
 
 zpool_status_t
-zpool_get_status(zpool_handle_t *zhp, char **msgid)
+zpool_get_status(zpool_handle_t *zhp, char **msgid, zpool_errata_t *errata)
 {
-	zpool_status_t ret = check_status(zhp->zpool_config, B_FALSE);
+	zpool_status_t ret = check_status(zhp->zpool_config, B_FALSE, errata);
 
 	if (ret >= NMSGID)
 		*msgid = NULL;
@@ -373,9 +384,9 @@ zpool_get_status(zpool_handle_t *zhp, char **msgid)
 }
 
 zpool_status_t
-zpool_import_status(nvlist_t *config, char **msgid)
+zpool_import_status(nvlist_t *config, char **msgid, zpool_errata_t *errata)
 {
-	zpool_status_t ret = check_status(config, B_TRUE);
+	zpool_status_t ret = check_status(config, B_TRUE, errata);
 
 	if (ret >= NMSGID)
 		*msgid = NULL;

module/zfs/dsl_scan.c

@@ -123,6 +123,42 @@ dsl_scan_init(dsl_pool_t *dp, uint64_t txg)
 		err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 		    DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS,
 		    &scn->scn_phys);
+		/*
+		 * Detect if the pool contains the signature of #2094.  If it
+		 * does properly update the scn->scn_phys structure and notify
+		 * the administrator by setting an errata for the pool.
+		 */
+		if (err == EOVERFLOW) {
+			uint64_t zaptmp[SCAN_PHYS_NUMINTS + 1];
+			VERIFY3S(SCAN_PHYS_NUMINTS, ==, 24);
+			VERIFY3S(offsetof(dsl_scan_phys_t, scn_flags), ==,
+			    (23 * sizeof (uint64_t)));
+
+			err = zap_lookup(dp->dp_meta_objset,
+			    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SCAN,
+			    sizeof (uint64_t), SCAN_PHYS_NUMINTS + 1, &zaptmp);
+			if (err == 0) {
+				uint64_t overflow = zaptmp[SCAN_PHYS_NUMINTS];
+
+				if (overflow & ~DSL_SCAN_FLAGS_MASK ||
+				    scn->scn_async_destroying) {
+					spa->spa_errata =
+					    ZPOOL_ERRATA_ZOL_2094_ASYNC_DESTROY;
+					return (EOVERFLOW);
+				}
+
+				bcopy(zaptmp, &scn->scn_phys,
+				    SCAN_PHYS_NUMINTS * sizeof (uint64_t));
+				scn->scn_phys.scn_flags = overflow;
+
+				/* Required scrub already in progress. */
+				if (scn->scn_phys.scn_state == DSS_FINISHED ||
+				    scn->scn_phys.scn_state == DSS_CANCELED)
+					spa->spa_errata =
+					    ZPOOL_ERRATA_ZOL_2094_SCRUB;
+			}
+		}
+
 		if (err == ENOENT)
 			return (0);
 		else if (err)
@@ -319,6 +355,9 @@ dsl_scan_done(dsl_scan_t *scn, boolean_t complete, dmu_tx_t *tx)
 	}
 
 	scn->scn_phys.scn_end_time = gethrestime_sec();
+
+	if (spa->spa_errata == ZPOOL_ERRATA_ZOL_2094_SCRUB)
+		spa->spa_errata = 0;
 }
 
 /* ARGSUSED */

module/zfs/spa.c

@@ -4083,6 +4083,8 @@ spa_tryimport(nvlist_t *tryconfig)
 		    spa->spa_uberblock.ub_timestamp) == 0);
 		VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
 		    spa->spa_load_info) == 0);
+		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_ERRATA,
+		    spa->spa_errata) == 0);
 
 		/*
 		 * If the bootfs property exists on this pool then we

module/zfs/spa_config.c

@@ -365,6 +365,8 @@ spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
 	    txg) == 0);
 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
 	    spa_guid(spa)) == 0);
+	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_ERRATA,
+	    spa->spa_errata) == 0);
 	VERIFY(spa->spa_comment == NULL || nvlist_add_string(config,
 	    ZPOOL_CONFIG_COMMENT, spa->spa_comment) == 0);
 

module/zfs/spa_stats.c

@@ -207,7 +207,6 @@ spa_read_history_add(spa_t *spa, const zbookmark_t *zb, uint32_t aflags)
 		return;
 
 	srh = kmem_zalloc(sizeof (spa_read_history_t), KM_PUSHPAGE);
-	strlcpy(srh->origin, zb->zb_func, sizeof (srh->origin));
 	strlcpy(srh->comm, getcomm(), sizeof (srh->comm));
 	srh->start  = gethrtime();
 	srh->objset = zb->zb_objset;

scripts/Makefile.am

@@ -7,6 +7,7 @@ dist_pkgdata_SCRIPTS = \
 	$(top_builddir)/scripts/common.sh \
 	$(top_srcdir)/scripts/zconfig.sh \
 	$(top_srcdir)/scripts/zfault.sh \
+	$(top_srcdir)/scripts/zimport.sh \
 	$(top_srcdir)/scripts/zfs.sh \
 	$(top_srcdir)/scripts/zpool-create.sh \
 	$(top_srcdir)/scripts/zpios.sh \
@@ -17,6 +18,7 @@ dist_pkgdata_SCRIPTS = \
 ZFS=$(top_builddir)/scripts/zfs.sh
 ZCONFIG=$(top_builddir)/scripts/zconfig.sh
 ZFAULT=$(top_builddir)/scripts/zfault.sh
+ZIMPORT=$(top_builddir)/scripts/zimport.sh
 ZTEST=$(top_builddir)/cmd/ztest/ztest
 ZPIOS_SANITY=$(top_builddir)/scripts/zpios-sanity.sh