Don't emit cksum_{actual_expected} in ereport.fs.zfs.checksum events

With anything but fletcher-4, even a tiny change in the input will cause
the checksum value to change completely.  So knowing the actual and
expected checksums doesn't provide much more information than "they
don't match".  The harm in sending them is simply that they bloat the
event.  In particular, on FreeBSD the event must fit into a 1016 byte
buffer.

Fixes #14717 for mirrored pools.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Alan Somers <asomers@gmail.com>
Sponsored-by: Axcient
Closes #14717
Closes #15052

include/sys/fm/fs/zfs.h

@@ -102,8 +102,6 @@ extern "C" {
 #define	FM_EREPORT_PAYLOAD_ZFS_ZIO_TIMESTAMP	"zio_timestamp"
 #define	FM_EREPORT_PAYLOAD_ZFS_ZIO_DELTA	"zio_delta"
 #define	FM_EREPORT_PAYLOAD_ZFS_PREV_STATE	"prev_state"
-#define	FM_EREPORT_PAYLOAD_ZFS_CKSUM_EXPECTED	"cksum_expected"
-#define	FM_EREPORT_PAYLOAD_ZFS_CKSUM_ACTUAL	"cksum_actual"
 #define	FM_EREPORT_PAYLOAD_ZFS_CKSUM_ALGO	"cksum_algorithm"
 #define	FM_EREPORT_PAYLOAD_ZFS_CKSUM_BYTESWAP	"cksum_byteswap"
 #define	FM_EREPORT_PAYLOAD_ZFS_BAD_OFFSET_RANGES "bad_ranges"

include/sys/zio_checksum.h

@@ -94,8 +94,6 @@ typedef const struct zio_checksum_info {
 } zio_checksum_info_t;
 
 typedef struct zio_bad_cksum {
-	zio_cksum_t		zbc_expected;
-	zio_cksum_t		zbc_actual;
 	const char		*zbc_checksum_name;
 	uint8_t			zbc_byteswapped;
 	uint8_t			zbc_injected;

man/man8/zpool-events.8

@@ -305,10 +305,6 @@ The time when a given I/O request was submitted.
 The time required to service a given I/O request.
 .It Sy prev_state
 The previous state of the vdev.
-.It Sy cksum_expected
-The expected checksum value for the block.
-.It Sy cksum_actual
-The actual checksum value for an errant block.
 .It Sy cksum_algorithm
 Checksum algorithm used.
 See

module/zfs/vdev_indirect.c

@@ -1398,7 +1398,7 @@ vdev_indirect_checksum_error(zio_t *zio,
 	vd->vdev_stat.vs_checksum_errors++;
 	mutex_exit(&vd->vdev_stat_lock);
 
-	zio_bad_cksum_t zbc = {{{ 0 }}};
+	zio_bad_cksum_t zbc = { 0 };
 	abd_t *bad_abd = ic->ic_data;
 	abd_t *good_abd = is->is_good_child->ic_data;
 	(void) zfs_ereport_post_checksum(zio->io_spa, vd, NULL, zio,

module/zfs/vdev_raidz.c

@@ -1785,7 +1785,7 @@ vdev_raidz_checksum_error(zio_t *zio, raidz_col_t *rc, abd_t *bad_data)
 static int
 raidz_checksum_verify(zio_t *zio)
 {
-	zio_bad_cksum_t zbc = {{{0}}};
+	zio_bad_cksum_t zbc = {0};
 	raidz_map_t *rm = zio->io_vsd;
 
 	int ret = zio_checksum_error(zio, &zbc);

module/zfs/zfs_fm.c

@@ -914,14 +914,6 @@ annotate_ecksum(nvlist_t *ereport, zio_bad_cksum_t *info,
 
 	if (info != NULL && info->zbc_has_cksum) {
 		fm_payload_set(ereport,
-		    FM_EREPORT_PAYLOAD_ZFS_CKSUM_EXPECTED,
-		    DATA_TYPE_UINT64_ARRAY,
-		    sizeof (info->zbc_expected) / sizeof (uint64_t),
-		    (uint64_t *)&info->zbc_expected,
-		    FM_EREPORT_PAYLOAD_ZFS_CKSUM_ACTUAL,
-		    DATA_TYPE_UINT64_ARRAY,
-		    sizeof (info->zbc_actual) / sizeof (uint64_t),
-		    (uint64_t *)&info->zbc_actual,
 		    FM_EREPORT_PAYLOAD_ZFS_CKSUM_ALGO,
 		    DATA_TYPE_STRING,
 		    info->zbc_checksum_name,

module/zfs/zio_checksum.c

@@ -515,8 +515,6 @@ zio_checksum_error_impl(spa_t *spa, const blkptr_t *bp,
 	}
 
 	if (info != NULL) {
-		info->zbc_expected = expected_cksum;
-		info->zbc_actual = actual_cksum;
 		info->zbc_checksum_name = ci->ci_name;
 		info->zbc_byteswapped = byteswap;
 		info->zbc_injected = 0;