Add device rebuild feature

The device_rebuild feature enables sequential reconstruction when
resilvering.  Mirror vdevs can be rebuilt in LBA order which may
more quickly restore redundancy depending on the pools average block
size, overall fragmentation and the performance characteristics
of the devices.  However, block checksums cannot be verified
as part of the rebuild thus a scrub is automatically started after
the sequential resilver completes.

The new '-s' option has been added to the `zpool attach` and
`zpool replace` command to request sequential reconstruction
instead of healing reconstruction when resilvering.

    zpool attach -s <pool> <existing vdev> <new vdev>
    zpool replace -s <pool> <old vdev> <new vdev>

The `zpool status` output has been updated to report the progress
of sequential resilvering in the same way as healing resilvering.
The one notable difference is that multiple sequential resilvers
may be in progress as long as they're operating on different
top-level vdevs.

The `zpool wait -t resilver` command was extended to wait on
sequential resilvers.  From this perspective they are no different
than healing resilvers.

Sequential resilvers cannot be supported for RAIDZ, but are
compatible with the dRAID feature being developed.

As part of this change the resilver_restart_* tests were moved
in to the functional/replacement directory.  Additionally, the
replacement tests were renamed and extended to verify both
resilvering and rebuilding.

Original-patch-by: Isaac Huang <he.huang@intel.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: John Poduska <jpoduska@datto.com>
Co-authored-by: Mark Maybee <mmaybee@cray.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #10349

include/sys/fs/zfs.h

@@ -704,6 +704,7 @@ typedef struct zpool_load_policy {
 #define	ZPOOL_CONFIG_SPLIT_LIST		"guid_list"
 #define	ZPOOL_CONFIG_REMOVING		"removing"
 #define	ZPOOL_CONFIG_RESILVER_TXG	"resilver_txg"
+#define	ZPOOL_CONFIG_REBUILD_TXG	"rebuild_txg"
 #define	ZPOOL_CONFIG_COMMENT		"comment"
 #define	ZPOOL_CONFIG_SUSPENDED		"suspended"	/* not stored on disk */
 #define	ZPOOL_CONFIG_SUSPENDED_REASON	"suspended_reason"	/* not stored */
@@ -730,6 +731,7 @@ typedef struct zpool_load_policy {
 #define	ZPOOL_CONFIG_MMP_HOSTID		"mmp_hostid"	/* not stored on disk */
 #define	ZPOOL_CONFIG_ALLOCATION_BIAS	"alloc_bias"	/* not stored on disk */
 #define	ZPOOL_CONFIG_EXPANSION_TIME	"expansion_time"	/* not stored */
+#define	ZPOOL_CONFIG_REBUILD_STATS	"org.openzfs:rebuild_stats"
 
 /*
  * The persistent vdev state is stored as separate values rather than a single
@@ -778,6 +780,9 @@ typedef struct zpool_load_policy {
 #define	VDEV_TOP_ZAP_MS_UNFLUSHED_PHYS_TXGS \
 	"com.delphix:ms_unflushed_phys_txgs"
 
+#define	VDEV_TOP_ZAP_VDEV_REBUILD_PHYS \
+	"org.openzfs:vdev_rebuild"
+
 #define	VDEV_TOP_ZAP_ALLOCATION_BIAS \
 	"org.zfsonlinux:allocation_bias"
 
@@ -991,6 +996,21 @@ typedef enum dsl_scan_state {
 	DSS_NUM_STATES
 } dsl_scan_state_t;
 
+typedef struct vdev_rebuild_stat {
+	uint64_t vrs_state;		/* vdev_rebuild_state_t */
+	uint64_t vrs_start_time;	/* time_t */
+	uint64_t vrs_end_time;		/* time_t */
+	uint64_t vrs_scan_time_ms;	/* total run time (millisecs) */
+	uint64_t vrs_bytes_scanned;	/* allocated bytes scanned */
+	uint64_t vrs_bytes_issued;	/* read bytes issued */
+	uint64_t vrs_bytes_rebuilt;	/* rebuilt bytes */
+	uint64_t vrs_bytes_est;		/* total bytes to scan */
+	uint64_t vrs_errors;		/* scanning errors */
+	uint64_t vrs_pass_time_ms;	/* pass run time (millisecs) */
+	uint64_t vrs_pass_bytes_scanned; /* bytes scanned since start/resume */
+	uint64_t vrs_pass_bytes_issued;	/* bytes rebuilt since start/resume */
+} vdev_rebuild_stat_t;
+
 /*
  * Errata described by https://zfsonlinux.org/msg/ZFS-8000-ER.  The ordering
  * of this enum must be maintained to ensure the errata identifiers map to
@@ -1047,6 +1067,7 @@ typedef struct vdev_stat {
 	uint64_t	vs_trim_bytes_est;	/* total bytes to trim */
 	uint64_t	vs_trim_state;		/* vdev_trim_state_t */
 	uint64_t	vs_trim_action_time;	/* time_t */
+	uint64_t	vs_rebuild_processed;	/* bytes rebuilt */
 } vdev_stat_t;
 
 /*
@@ -1178,6 +1199,13 @@ typedef enum {
 	VDEV_TRIM_COMPLETE,
 } vdev_trim_state_t;
 
+typedef enum {
+	VDEV_REBUILD_NONE,
+	VDEV_REBUILD_ACTIVE,
+	VDEV_REBUILD_CANCELED,
+	VDEV_REBUILD_COMPLETE,
+} vdev_rebuild_state_t;
+
 /*
  * nvlist name constants. Facilitate restricting snapshot iteration range for
  * the "list next snapshot" ioctl
@@ -1337,6 +1365,8 @@ typedef enum {
 	ZFS_ERR_BOOKMARK_SOURCE_NOT_ANCESTOR,
 	ZFS_ERR_STREAM_TRUNCATED,
 	ZFS_ERR_STREAM_LARGE_BLOCK_MISMATCH,
+	ZFS_ERR_RESILVER_IN_PROGRESS,
+	ZFS_ERR_REBUILD_IN_PROGRESS,
 } zfs_errno_t;
 
 /*
@@ -1478,7 +1508,12 @@ typedef enum {
  * given payloads:
  *
  *	ESC_ZFS_RESILVER_START
- *	ESC_ZFS_RESILVER_END
+ *	ESC_ZFS_RESILVER_FINISH
+ *
+ *		ZFS_EV_POOL_NAME	DATA_TYPE_STRING
+ *		ZFS_EV_POOL_GUID	DATA_TYPE_UINT64
+ *		ZFS_EV_RESILVER_TYPE	DATA_TYPE_STRING
+ *
  *	ESC_ZFS_POOL_DESTROY
  *	ESC_ZFS_POOL_REGUID
  *
@@ -1532,6 +1567,7 @@ typedef enum {
 #define	ZFS_EV_HIST_IOCTL	"history_ioctl"
 #define	ZFS_EV_HIST_DSNAME	"history_dsname"
 #define	ZFS_EV_HIST_DSID	"history_dsid"
+#define	ZFS_EV_RESILVER_TYPE	"resilver_type"
 
 #ifdef	__cplusplus
 }