Upstream: Add snapshot and zvol events

For kernel to send snapshot mount/unmount events to zed.

For kernel to send symlink creates/removes on zvol plumbing.
(/dev/run/dsk/zvol/$pool/$zvol -> /dev/diskX)

If zed misses the ENODEV, all errors after are EINVAL. Treat any error
as kernel module failure.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes #12416

include/sys/fm/fs/zfs.h

@@ -110,6 +110,10 @@ extern "C" {
 #define	FM_EREPORT_PAYLOAD_ZFS_BAD_CLEARED_BITS	"bad_cleared_bits"
 #define	FM_EREPORT_PAYLOAD_ZFS_BAD_SET_HISTOGRAM "bad_set_histogram"
 #define	FM_EREPORT_PAYLOAD_ZFS_BAD_CLEARED_HISTOGRAM "bad_cleared_histogram"
+#define	FM_EREPORT_PAYLOAD_ZFS_SNAPSHOT_NAME	"snapshot_name"
+#define	FM_EREPORT_PAYLOAD_ZFS_DEVICE_NAME	"device_name"
+#define	FM_EREPORT_PAYLOAD_ZFS_RAW_DEVICE_NAME	"raw_name"
+#define	FM_EREPORT_PAYLOAD_ZFS_VOLUME	"volume"
 
 #define	FM_EREPORT_FAILMODE_WAIT		"wait"
 #define	FM_EREPORT_FAILMODE_CONTINUE		"continue"
@@ -119,6 +123,11 @@ extern "C" {
 #define	FM_RESOURCE_AUTOREPLACE			"autoreplace"
 #define	FM_RESOURCE_STATECHANGE			"statechange"
 
+#define	FM_RESOURCE_ZFS_SNAPSHOT_MOUNT		"snapshot_mount"
+#define	FM_RESOURCE_ZFS_SNAPSHOT_UNMOUNT		"snapshot_unmount"
+#define	FM_RESOURCE_ZVOL_CREATE_SYMLINK		"zvol_create"
+#define	FM_RESOURCE_ZVOL_REMOVE_SYMLINK		"zvol_remove"
+
 #ifdef	__cplusplus
 }
 #endif

include/sys/spa.h

@@ -1170,6 +1170,8 @@ extern void spa_configfile_set(spa_t *, nvlist_t *, boolean_t);
 /* asynchronous event notification */
 extern void spa_event_notify(spa_t *spa, vdev_t *vdev, nvlist_t *hist_nvl,
     const char *name);
+extern void zfs_ereport_zvol_post(const char *subclass, const char *name,
+    const char *device_name, const char *raw_name);
 
 /* waiting for pool activities to complete */
 extern int spa_wait(const char *pool, zpool_wait_activity_t activity,

include/sys/zio.h

@@ -673,6 +673,8 @@ extern int zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
     struct zio_bad_cksum *info);
 
 void zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr);
+extern void zfs_ereport_snapshot_post(const char *subclass, spa_t *spa,
+    const char *name);
 
 /* Called from spa_sync(), but primarily an injection handler */
 extern void spa_handle_ignored_writes(spa_t *spa);