Illumos #3561, #3116

3561 arc_meta_limit should be exposed via kstats
3116 zpool reguid may log negative guids to internal SPA history
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Gordon Ross <gordon.ross@nexenta.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/3561
  https://www.illumos.org/issues/3116
  illumos/illumos-gate@20128a0826f9c53167caa9215c12f08beee48e30

Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Porting Notes:

1. The spa change was accidentally included in the libzfs_core merge.

2. "Add missing arcstats" (1834f2d8b715d25bafbb0e4a099994f45c3211ae)
   already implemented these kstats a few years ago.

diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index 6ad145bc45f5b1aed482547b7503d7eeffd6175d..0cfcde7ac610a6868eb286a5b344b55b5362bdfb 100644 (file)
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -479,9 +479,9 @@ static arc_state_t  *arc_l2c_only;
 #define        arc_no_grow     ARCSTAT(arcstat_no_grow)
 #define        arc_tempreserve ARCSTAT(arcstat_tempreserve)
 #define        arc_loaned_bytes        ARCSTAT(arcstat_loaned_bytes)
-#define        arc_meta_used   ARCSTAT(arcstat_meta_used)
-#define        arc_meta_limit  ARCSTAT(arcstat_meta_limit)
-#define        arc_meta_max    ARCSTAT(arcstat_meta_max)
+#define        arc_meta_limit  ARCSTAT(arcstat_meta_limit) /* max size for metadata */
+#define        arc_meta_used   ARCSTAT(arcstat_meta_used) /* size of metadata */
+#define        arc_meta_max    ARCSTAT(arcstat_meta_max) /* max size of metadata */
 
 #define        L2ARC_IS_VALID_COMPRESS(_c_) \
        ((_c_) == ZIO_COMPRESS_LZ4 || (_c_) == ZIO_COMPRESS_EMPTY)
@@ -1305,7 +1305,7 @@ arc_space_consume(uint64_t space, arc_space_type_t type)
                break;
        }
 
-       atomic_add_64(&arc_meta_used, space);
+       ARCSTAT_INCR(arcstat_meta_used, space);
        atomic_add_64(&arc_size, space);
 }
 
@@ -1334,7 +1334,7 @@ arc_space_return(uint64_t space, arc_space_type_t type)
        ASSERT(arc_meta_used >= space);
        if (arc_meta_max < arc_meta_used)
                arc_meta_max = arc_meta_used;
-       atomic_add_64(&arc_meta_used, -space);
+       ARCSTAT_INCR(arcstat_meta_used, -space);
        ASSERT(arc_size >= space);
        atomic_add_64(&arc_size, -space);
 }