Allow an option to set the process title during a zfs send.

This code is modified from iXsystem's implementation.

config/user-setproctitle.m4

@@ -0,0 +1,12 @@
+dnl #
+dnl # Check for setproctitle
+dnl # In BSD, this is in libc; in Linux, it tends to be in -lbsd
+dnl #
+AC_DEFUN([ZFS_AC_CONFIG_USER_SETPROCTITLE], [
+	AC_SEARCH_LIBS([setproctitle], [bsd], [
+		AC_DEFINE(HAVE_PROCTITLE, 1,
+			[Define if the system has setproctitle])
+		]
+	)
+
+])

config/user.m4

@@ -8,6 +8,7 @@ AC_DEFUN([ZFS_AC_CONFIG_USER], [
 	ZFS_AC_CONFIG_USER_SYSVINIT
 	ZFS_AC_CONFIG_USER_DRACUT
 	ZFS_AC_CONFIG_USER_ZLIB
+	ZFS_AC_CONFIG_USER_SETPROCTITLE
 	ZFS_AC_CONFIG_USER_LIBUUID
 	ZFS_AC_CONFIG_USER_LIBTIRPC
 	ZFS_AC_CONFIG_USER_LIBBLKID

lib/libzfs/Makefile.am

@@ -61,7 +61,7 @@ libzfs_la_LIBADD = \
 	$(top_builddir)/lib/libzfs_core/libzfs_core.la \
 	$(top_builddir)/lib/libzutil/libzutil.la
 
-libzfs_la_LIBADD += -lm $(LIBSSL)
+libzfs_la_LIBADD += -lm ${BSDLIB} $(LIBSSL)
 libzfs_la_LDFLAGS = -version-info 2:0:0
 
 EXTRA_DIST = $(libzfs_pc_DATA) $(USER_C)

lib/libzfs/libzfs_sendrecv.c

@@ -1223,8 +1223,10 @@ send_progress_thread(void *arg)
 			if (pct > 100)
 				pct = 100;
 
+#ifdef HAVE_PROCTITLE
 			setproctitle("sending %s (%d%%: %llu/%llu)",
 			    zhp->zfs_name, pct, bytes, pa->pa_size);
+#endif /* HAVE_PROCTITLE */
 		} else {
 			if (pa->pa_parsable) {
 				(void) fprintf(stderr, "%02d:%02d:%02d\t%llu\t%s\n",
@@ -1295,6 +1297,7 @@ dump_snapshot(zfs_handle_t *zhp, void *arg)
 	boolean_t isfromsnap, istosnap, fromorigin;
 	boolean_t exclude = B_FALSE;
 	FILE *fout = sdd->std_out ? stdout : stderr;
+	uint64_t size = 0;
 
 	err = 0;
 	thissnap = strchr(zhp->zfs_name, '@') + 1;
@@ -1372,8 +1375,7 @@ dump_snapshot(zfs_handle_t *zhp, void *arg)
 	fromorigin = sdd->prevsnap[0] == '\0' &&
 	    (sdd->fromorigin || sdd->replicate);
 
-	if (sdd->verbose) {
-		uint64_t size = 0;
+	if (sdd->progress && sdd->dryrun) {
 		char fromds[ZFS_MAX_DATASET_NAME_LEN];
 
 		if (sdd->prevsnap[0] != '\0') {
@@ -1384,13 +1386,15 @@ dump_snapshot(zfs_handle_t *zhp, void *arg)
 		if (zfs_send_space(zhp, zhp->zfs_name,
 		    sdd->prevsnap[0] ? fromds : NULL, flags, &size) != 0) {
 			size = 0; /* cannot estimate send space */
-		} else {
-			send_print_verbose(fout, zhp->zfs_name,
-			    sdd->prevsnap[0] ? sdd->prevsnap : NULL,
-			    size, sdd->parsable);
 		}
 		sdd->size += size;
 	}
+
+	if (sdd->verbose) {
+		send_print_verbose(fout, zhp->zfs_name,
+		     sdd->prevsnap[0] ? sdd->prevsnap : NULL,
+		     size, sdd->parsable);
+	}
 
 	if (!sdd->dryrun) {
 		/*
@@ -1776,6 +1780,7 @@ zfs_send_resume(libzfs_handle_t *hdl, sendflags_t *flags, int outfd,
 			pa.pa_zhp = zhp;
 			pa.pa_fd = outfd;
 			pa.pa_parsable = flags->parsable;
+			pa.pa_astitle = flags->progressastitle;
 
 			error = pthread_create(&tid, NULL,
 			    send_progress_thread, &pa);

man/man8/zfs.8

@@ -30,7 +30,7 @@
 .\" Copyright 2018 Nexenta Systems, Inc.
 .\" Copyright 2018 Joyent, Inc.
 .\"
-.Dd Jan 05, 2019
+.Dd Feb 15, 2019
 .Dt ZFS 8 SMM
 .Os Linux
 .Sh NAME
@@ -195,17 +195,17 @@
 .Ar snapshot bookmark
 .Nm
 .Cm send
-.Op Fl DLPRbcenpvw
+.Op Fl DLPRVbcenpvw
 .Op Oo Fl I Ns | Ns Fl i Oc Ar snapshot
 .Ar snapshot
 .Nm
 .Cm send
-.Op Fl LPcenvw
+.Op Fl LPVcenvw
 .Op Fl i Ar snapshot Ns | Ns Ar bookmark
 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot
 .Nm
 .Cm send
-.Op Fl Penv
+.Op Fl PVenv
 .Fl t Ar receive_resume_token
 .Nm
 .Cm receive
@@ -3724,6 +3724,11 @@ and the verbose output goes to standard error
 .It Fl v, -verbose
 Print verbose information about the stream package generated.
 This information includes a per-second report of how much data has been sent.
+.It Fl V
+Set the process title to a per-second report of how much data has been sent.
+(On systems without
+.Fn setproctitle
+support, this option succeeds, but does not change the process title.)
 .El
 .It Xo
 .Nm