Add pool state /proc entry, "SUSPENDED" pools

1. Add a proc entry to display the pool's state:

$ cat /proc/spl/kstat/zfs/tank/state
ONLINE

This is done without using the spa config locks, so it will
never hang.

2. Fix 'zpool status' and 'zpool list -o health' output to print
"SUSPENDED" instead of "ONLINE" for suspended pools.

Reviewed-by: Olaf Faaland <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed by: Richard Elling <[email protected]>
Signed-off-by: Tony Hutter <[email protected]>
Closes #7331 
Closes #7563 

3 files changed, 8 insertions, 4 deletions

diff --git a/include/libzfs.h b/include/libzfs.h
index 7ea6d7fa0..b98963158 100644
--- a/include/libzfs.h
+++ b/include/libzfs.h
@@ -301,6 +301,8 @@ int zfs_dev_is_whole_disk(char *dev_name);
 char *zfs_get_underlying_path(char *dev_name);
 char *zfs_get_enclosure_sysfs_path(char *dev_name);
 
+const char *zpool_get_state_str(zpool_handle_t *);
+
 /*
  * Functions to manage pool properties
  */
diff --git a/include/spl/sys/kstat.h b/include/spl/sys/kstat.h
index 9170fe24e..f197ce455 100644
--- a/include/spl/sys/kstat.h
+++ b/include/spl/sys/kstat.h
@@ -69,10 +69,9 @@
 #define	KSTAT_FLAG_WRITABLE	0x04
 #define	KSTAT_FLAG_PERSISTENT	0x08
 #define	KSTAT_FLAG_DORMANT	0x10
-#define	KSTAT_FLAG_UNSUPPORTED	\
-	(KSTAT_FLAG_VAR_SIZE | KSTAT_FLAG_WRITABLE | \
-	KSTAT_FLAG_PERSISTENT | KSTAT_FLAG_DORMANT)
-
+#define	KSTAT_FLAG_INVALID	0x20
+#define	KSTAT_FLAG_LONGSTRINGS	0x40
+#define	KSTAT_FLAG_NO_HEADERS	0x80
 
 #define	KS_MAGIC		0x9d9d9d9d
 
diff --git a/include/sys/spa.h b/include/sys/spa.h
index 8a3938e86..e8578be9a 100644
--- a/include/sys/spa.h
+++ b/include/sys/spa.h
@@ -873,6 +873,7 @@ typedef struct spa_stats {
 	spa_stats_history_t	tx_assign_histogram;
 	spa_stats_history_t	io_history;
 	spa_stats_history_t	mmp_history;
+	spa_stats_history_t	state;		/* pool state */
 } spa_stats_t;
 
 typedef enum txg_state {
@@ -1048,6 +1049,8 @@ extern void spa_history_log_internal_ds(struct dsl_dataset *ds, const char *op,
 extern void spa_history_log_internal_dd(dsl_dir_t *dd, const char *operation,
     dmu_tx_t *tx, const char *fmt, ...);
 
+extern const char *spa_state_to_name(spa_t *spa);
+
 /* error handling */
 struct zbookmark_phys;
 extern void spa_log_error(spa_t *spa, const zbookmark_phys_t *zb);