2605 want to resume interrupted zfs send

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Xin Li <delphij@freebsd.org>
Reviewed by: Arne Jansen <sensille@gmx.net>
Approved by: Dan McDonald <danmcd@omniti.com>

3 files changed, 58 insertions, 21 deletions

diff --git a/usr/src/lib/libzfs_core/common/libzfs_core.c b/usr/src/lib/libzfs_core/common/libzfs_core.c
index 22af0f4a7a..d66f338a78 100644
--- a/usr/src/lib/libzfs_core/common/libzfs_core.c
+++ b/usr/src/lib/libzfs_core/common/libzfs_core.c
@@ -468,6 +468,13 @@ int
 lzc_send(const char *snapname, const char *from, int fd,
     enum lzc_send_flags flags)
 {
+	return (lzc_send_resume(snapname, from, fd, flags, 0, 0));
+}
+
+int
+lzc_send_resume(const char *snapname, const char *from, int fd,
+    enum lzc_send_flags flags, uint64_t resumeobj, uint64_t resumeoff)
+{
 	nvlist_t *args;
 	int err;
 
@@ -479,6 +486,10 @@ lzc_send(const char *snapname, const char *from, int fd,
 		fnvlist_add_boolean(args, "largeblockok");
 	if (flags & LZC_SEND_FLAG_EMBED_DATA)
 		fnvlist_add_boolean(args, "embedok");
+	if (resumeobj != 0 || resumeoff != 0) {
+		fnvlist_add_uint64(args, "resume_object", resumeobj);
+		fnvlist_add_uint64(args, "resume_offset", resumeoff);
+	}
 	err = lzc_ioctl(ZFS_IOC_SEND_NEW, snapname, args, NULL);
 	nvlist_free(args);
 	return (err);
@@ -536,22 +547,9 @@ recv_read(int fd, void *buf, int ilen)
 	return (0);
 }
 
-/*
- * The simplest receive case: receive from the specified fd, creating the
- * specified snapshot.  Apply the specified properties a "received" properties
- * (which can be overridden by locally-set properties).  If the stream is a
- * clone, its origin snapshot must be specified by 'origin'.  The 'force'
- * flag will cause the target filesystem to be rolled back or destroyed if
- * necessary to receive.
- *
- * Return 0 on success or an errno on failure.
- *
- * Note: this interface does not work on dedup'd streams
- * (those with DMU_BACKUP_FEATURE_DEDUP).
- */
-int
-lzc_receive(const char *snapname, nvlist_t *props, const char *origin,
-    boolean_t force, int fd)
+static int
+lzc_receive_impl(const char *snapname, nvlist_t *props, const char *origin,
+    boolean_t force, boolean_t resumable, int fd)
 {
 	/*
 	 * The receive ioctl is still legacy, so we need to construct our own
@@ -561,7 +559,6 @@ lzc_receive(const char *snapname, nvlist_t *props, const char *origin,
 	char *atp;
 	char *packed = NULL;
 	size_t size;
-	dmu_replay_record_t drr;
 	int error;
 
 	ASSERT3S(g_refcount, >, 0);
@@ -597,10 +594,9 @@ lzc_receive(const char *snapname, nvlist_t *props, const char *origin,
 		(void) strlcpy(zc.zc_string, origin, sizeof (zc.zc_string));
 
 	/* zc_begin_record is non-byteswapped BEGIN record */
-	error = recv_read(fd, &drr, sizeof (drr));
+	error = recv_read(fd, &zc.zc_begin_record, sizeof (zc.zc_begin_record));
 	if (error != 0)
 		goto out;
-	zc.zc_begin_record = drr.drr_u.drr_begin;
 
 	/* zc_cookie is fd to read from */
 	zc.zc_cookie = fd;
@@ -608,6 +604,8 @@ lzc_receive(const char *snapname, nvlist_t *props, const char *origin,
 	/* zc guid is force flag */
 	zc.zc_guid = force;
 
+	zc.zc_resumable = resumable;
+
 	/* zc_cleanup_fd is unused */
 	zc.zc_cleanup_fd = -1;
 
@@ -623,6 +621,39 @@ out:
 }
 
 /*
+ * The simplest receive case: receive from the specified fd, creating the
+ * specified snapshot.  Apply the specified properties as "received" properties
+ * (which can be overridden by locally-set properties).  If the stream is a
+ * clone, its origin snapshot must be specified by 'origin'.  The 'force'
+ * flag will cause the target filesystem to be rolled back or destroyed if
+ * necessary to receive.
+ *
+ * Return 0 on success or an errno on failure.
+ *
+ * Note: this interface does not work on dedup'd streams
+ * (those with DMU_BACKUP_FEATURE_DEDUP).
+ */
+int
+lzc_receive(const char *snapname, nvlist_t *props, const char *origin,
+    boolean_t force, int fd)
+{
+	return (lzc_receive_impl(snapname, props, origin, force, B_FALSE, fd));
+}
+
+/*
+ * Like lzc_receive, but if the receive fails due to premature stream
+ * termination, the intermediate state will be preserved on disk.  In this
+ * case, ECKSUM will be returned.  The receive may subsequently be resumed
+ * with a resuming send stream generated by lzc_send_resume().
+ */
+int
+lzc_receive_resumable(const char *snapname, nvlist_t *props, const char *origin,
+    boolean_t force, int fd)
+{
+	return (lzc_receive_impl(snapname, props, origin, force, B_TRUE, fd));
+}
+
+/*
  * Roll back this filesystem or volume to its most recent snapshot.
  * If snapnamebuf is not NULL, it will be filled in with the name
  * of the most recent snapshot.
diff --git a/usr/src/lib/libzfs_core/common/libzfs_core.h b/usr/src/lib/libzfs_core/common/libzfs_core.h
index bdd6c951ee..5d3a6fda7d 100644
--- a/usr/src/lib/libzfs_core/common/libzfs_core.h
+++ b/usr/src/lib/libzfs_core/common/libzfs_core.h
@@ -20,7 +20,7 @@
  */
 
 /*
- * Copyright (c) 2013 by Delphix. All rights reserved.
+ * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
  */
 
 #ifndef	_LIBZFS_CORE_H
@@ -58,7 +58,11 @@ enum lzc_send_flags {
 };
 
 int lzc_send(const char *, const char *, int, enum lzc_send_flags);
+int lzc_send_resume(const char *, const char *, int,
+    enum lzc_send_flags, uint64_t, uint64_t);
 int lzc_receive(const char *, nvlist_t *, const char *, boolean_t, int);
+int lzc_receive_resumable(const char *, nvlist_t *, const char *,
+    boolean_t, int);
 int lzc_send_space(const char *, const char *, uint64_t *);
 
 boolean_t lzc_exists(const char *);
diff --git a/usr/src/lib/libzfs_core/common/mapfile-vers b/usr/src/lib/libzfs_core/common/mapfile-vers
index ebed35cfd0..acd4efb07e 100644
--- a/usr/src/lib/libzfs_core/common/mapfile-vers
+++ b/usr/src/lib/libzfs_core/common/mapfile-vers
@@ -19,7 +19,7 @@
 # CDDL HEADER END
 #
 # Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
-# Copyright (c) 2013 by Delphix. All rights reserved.
+# Copyright (c) 2012, 2014 by Delphix. All rights reserved.
 #
 # MAPFILE HEADER START
 #
@@ -51,9 +51,11 @@ SYMBOL_VERSION ILLUMOS_0.1 {
 	lzc_get_holds;
 	lzc_hold;
 	lzc_receive;
+	lzc_receive_resumable;
 	lzc_release;
 	lzc_rollback;
 	lzc_send;
+	lzc_send_resume;
 	lzc_send_space;
 	lzc_snaprange_space;
 	lzc_snapshot;