10554 Implemented zpool sync command

illumos/illumos-gate@9c2acf00e275b6b2125a306f33cdddcc58393220
https://github.com/illumos/illumos-gate/commit/9c2acf00e275b6b2125a306f33cdddcc58393220

https://www.illumos.org/issues/10554
  During the port of MMP (illumos bug 10499) from ZoL, I found this
  earlier ZoL project is a prerequisite. Here is the original
  description.  This addition will enable us to sync an open TXG to the
  main pool on demand. The functionality is similar to 'sync(2)' but
  'zpool sync' will return when data has hit the main storage instead of
  potentially just the ZIL as is the case with the 'sync(2)' cmd.

Portions contributed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Author: Alek Pinchuk <apinchuk@datto.com>

4 files changed, 49 insertions, 11 deletions

diff --git a/lib/libzfs/common/libzfs.h b/lib/libzfs/common/libzfs.h
index d296fed59f01..ce3ef0f8a851 100644
--- a/lib/libzfs/common/libzfs.h
+++ b/lib/libzfs/common/libzfs.h
@@ -269,6 +269,8 @@ extern int zpool_clear(zpool_handle_t *, const char *, nvlist_t *);
 extern int zpool_reguid(zpool_handle_t *);
 extern int zpool_reopen(zpool_handle_t *);
 
+extern int zpool_sync_one(zpool_handle_t *, void *);
+
 extern int zpool_vdev_online(zpool_handle_t *, const char *, int,
     vdev_state_t *);
 extern int zpool_vdev_offline(zpool_handle_t *, const char *, boolean_t);
diff --git a/lib/libzfs/common/libzfs_pool.c b/lib/libzfs/common/libzfs_pool.c
index b580772d5817..8504609b5ca2 100644
--- a/lib/libzfs/common/libzfs_pool.c
+++ b/lib/libzfs/common/libzfs_pool.c
@@ -3504,6 +3504,27 @@ zpool_reopen(zpool_handle_t *zhp)
 	return (zpool_standard_error(hdl, errno, msg));
 }
 
+/* call into libzfs_core to execute the sync IOCTL per pool */
+int
+zpool_sync_one(zpool_handle_t *zhp, void *data)
+{
+	int ret;
+	libzfs_handle_t *hdl = zpool_get_handle(zhp);
+	const char *pool_name = zpool_get_name(zhp);
+	boolean_t *force = data;
+	nvlist_t *innvl = fnvlist_alloc();
+
+	fnvlist_add_boolean_value(innvl, "force", *force);
+	if ((ret = lzc_sync(pool_name, innvl, NULL)) != 0) {
+		nvlist_free(innvl);
+		return (zpool_standard_error_fmt(hdl, ret,
+		    dgettext(TEXT_DOMAIN, "sync '%s' failed"), pool_name));
+	}
+	nvlist_free(innvl);
+
+	return (0);
+}
+
 /*
  * Convert from a devid string to a path.
  */
diff --git a/lib/libzfs_core/common/libzfs_core.c b/lib/libzfs_core/common/libzfs_core.c
index 268f1d6a7a45..79e9901bd7e0 100644
--- a/lib/libzfs_core/common/libzfs_core.c
+++ b/lib/libzfs_core/common/libzfs_core.c
@@ -24,6 +24,7 @@
  * Copyright (c) 2013 Steven Hartland. All rights reserved.
  * Copyright (c) 2014 Integros [integros.com]
  * Copyright 2017 RackTop Systems.
+ * Copyright (c) 2017 Datto Inc.
  */
 
 /*
@@ -128,17 +129,20 @@ lzc_ioctl(zfs_ioc_t ioc, const char *name,
 {
 	zfs_cmd_t zc = { 0 };
 	int error = 0;
-	char *packed;
-	size_t size;
+	char *packed = NULL;
+	size_t size = 0;
 
 	ASSERT3S(g_refcount, >, 0);
 	VERIFY3S(g_fd, !=, -1);
 
-	(void) strlcpy(zc.zc_name, name, sizeof (zc.zc_name));
+	if (name != NULL)
+		(void) strlcpy(zc.zc_name, name, sizeof (zc.zc_name));
 
-	packed = fnvlist_pack(source, &size);
-	zc.zc_nvlist_src = (uint64_t)(uintptr_t)packed;
-	zc.zc_nvlist_src_size = size;
+	if (source != NULL) {
+		packed = fnvlist_pack(source, &size);
+		zc.zc_nvlist_src = (uint64_t)(uintptr_t)packed;
+		zc.zc_nvlist_src_size = size;
+	}
 
 	if (resultp != NULL) {
 		*resultp = NULL;
@@ -416,6 +420,18 @@ lzc_exists(const char *dataset)
 }
 
 /*
+ * outnvl is unused.
+ * It was added to preserve the function signature in case it is
+ * needed in the future.
+ */
+/*ARGSUSED*/
+int
+lzc_sync(const char *pool_name, nvlist_t *innvl, nvlist_t **outnvl)
+{
+	return (lzc_ioctl(ZFS_IOC_POOL_SYNC, pool_name, innvl, NULL));
+}
+
+/*
  * Create "user holds" on snapshots.  If there is a hold on a snapshot,
  * the snapshot can not be destroyed.  (However, it can be marked for deletion
  * by lzc_destroy_snaps(defer=B_TRUE).)
@@ -515,11 +531,7 @@ lzc_release(nvlist_t *holds, nvlist_t **errlist)
 int
 lzc_get_holds(const char *snapname, nvlist_t **holdsp)
 {
-	int error;
-	nvlist_t *innvl = fnvlist_alloc();
-	error = lzc_ioctl(ZFS_IOC_GET_HOLDS, snapname, innvl, holdsp);
-	fnvlist_free(innvl);
-	return (error);
+	return (lzc_ioctl(ZFS_IOC_GET_HOLDS, snapname, NULL, holdsp));
 }
 
 /*
diff --git a/lib/libzfs_core/common/libzfs_core.h b/lib/libzfs_core/common/libzfs_core.h
index 7dc618403e6e..cbc0c68af8fc 100644
--- a/lib/libzfs_core/common/libzfs_core.h
+++ b/lib/libzfs_core/common/libzfs_core.h
@@ -23,6 +23,7 @@
  * Copyright (c) 2012, 2016 by Delphix. All rights reserved.
  * Copyright (c) 2014 Integros [integros.com]
  * Copyright 2017 RackTop Systems.
+ * Copyright (c) 2017 Datto Inc.
  */
 
 #ifndef	_LIBZFS_CORE_H
@@ -91,6 +92,8 @@ boolean_t lzc_exists(const char *);
 int lzc_rollback(const char *, char *, int);
 int lzc_rollback_to(const char *, const char *);
 
+int lzc_sync(const char *, nvlist_t *, nvlist_t **);
+
 int lzc_rename(const char *, const char *);
 int lzc_destroy(const char *);