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

cmd/zed/agents/zfs_retire.c

@@ -41,6 +41,7 @@
 #include <libzutil.h>
 #include <libzfs.h>
 #include <string.h>
+#include <libgen.h>
 
 #include "zfs_agents.h"
 #include "fmd_api.h"

cmd/zed/zed.c

@@ -291,7 +291,7 @@ idle:
 		rv = zed_event_service(&zcp);
 
 		/* ENODEV: When kernel module is unloaded (osx) */
-		if (rv == ENODEV)
+		if (rv != 0)
 			break;
 	}
 

cmd/zed/zed_conf.c

@@ -22,6 +22,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/uio.h>
 #include <unistd.h>

cmd/zed/zed_exec.c

@@ -26,6 +26,8 @@
 #include <time.h>
 #include <unistd.h>
 #include <pthread.h>
+#include <signal.h>
+
 #include "zed_exec.h"
 #include "zed_log.h"
 #include "zed_strings.h"

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);

module/zfs/zfs_fm.c

@@ -1444,6 +1444,58 @@ zfs_ereport_fini(void)
 	mutex_destroy(&recent_events_lock);
 }
 
+void
+zfs_ereport_snapshot_post(const char *subclass, spa_t *spa, const char *name)
+{
+	nvlist_t *aux;
+
+	aux = fm_nvlist_create(NULL);
+	nvlist_add_string(aux, FM_EREPORT_PAYLOAD_ZFS_SNAPSHOT_NAME, name);
+
+	zfs_post_common(spa, NULL, FM_RSRC_CLASS, subclass, aux);
+	fm_nvlist_destroy(aux, FM_NVA_FREE);
+}
+
+/*
+ * Post when a event when a zvol is created or removed
+ *
+ * This is currently only used by macOS, since it uses the event to create
+ * symlinks between the volume name (mypool/myvol) and the actual /dev
+ * device (/dev/disk3).  For example:
+ *
+ * /var/run/zfs/dsk/mypool/myvol -> /dev/disk3
+ *
+ * name: The full name of the zvol ("mypool/myvol")
+ * dev_name: The full /dev name for the zvol ("/dev/disk3")
+ * raw_name: The raw  /dev name for the zvol ("/dev/rdisk3")
+ */
+void
+zfs_ereport_zvol_post(const char *subclass, const char *name,
+    const char *dev_name, const char *raw_name)
+{
+	nvlist_t *aux;
+	char *r;
+
+	boolean_t locked = mutex_owned(&spa_namespace_lock);
+	if (!locked) mutex_enter(&spa_namespace_lock);
+	spa_t *spa = spa_lookup(name);
+	if (!locked) mutex_exit(&spa_namespace_lock);
+
+	if (spa == NULL)
+		return;
+
+	aux = fm_nvlist_create(NULL);
+	nvlist_add_string(aux, FM_EREPORT_PAYLOAD_ZFS_DEVICE_NAME, dev_name);
+	nvlist_add_string(aux, FM_EREPORT_PAYLOAD_ZFS_RAW_DEVICE_NAME,
+	    raw_name);
+	r = strchr(name, '/');
+	if (r && r[1])
+		nvlist_add_string(aux, FM_EREPORT_PAYLOAD_ZFS_VOLUME, &r[1]);
+
+	zfs_post_common(spa, NULL, FM_RSRC_CLASS, subclass, aux);
+	fm_nvlist_destroy(aux, FM_NVA_FREE);
+}
+
 EXPORT_SYMBOL(zfs_ereport_post);
 EXPORT_SYMBOL(zfs_ereport_is_valid);
 EXPORT_SYMBOL(zfs_ereport_post_checksum);