Use setproctitle to report progress of zfs send

This allows parsing of zfs send progress by checking the process
title.
Doing so requires some changes to the send code in libzfs_sendrecv.c;
primarily these changes move some of the accounting around, to allow
for the code to be verbose as normal, or set the process title. Unlike
BSD, setproctitle() isn't standard in Linux; thus, borrowed it from
libbsd with slight modifications.

Authored-by: Sean Eric Fagan <sef@FreeBSD.org>
Co-authored-by: Ryan Moeller <ryan@iXsystems.com>
Co-authored-by: Ameer Hamza <ahamza@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes #14376

cmd/zfs/zfs_main.c

@@ -315,14 +315,14 @@ get_usage(zfs_help_t idx)
 	case HELP_ROLLBACK:
 		return (gettext("\trollback [-rRf] <snapshot>\n"));
 	case HELP_SEND:
-		return (gettext("\tsend [-DnPpRvLecwhb] [-[i|I] snapshot] "
+		return (gettext("\tsend [-DnPpRVvLecwhb] [-[i|I] snapshot] "
 		    "<snapshot>\n"
-		    "\tsend [-DnvPLecw] [-i snapshot|bookmark] "
+		    "\tsend [-DnVvPLecw] [-i snapshot|bookmark] "
 		    "<filesystem|volume|snapshot>\n"
-		    "\tsend [-DnPpvLec] [-i bookmark|snapshot] "
+		    "\tsend [-DnPpVvLec] [-i bookmark|snapshot] "
 		    "--redact <bookmark> <snapshot>\n"
-		    "\tsend [-nvPe] -t <receive_resume_token>\n"
+		    "\tsend [-nVvPe] -t <receive_resume_token>\n"
-		    "\tsend [-Pnv] --saved filesystem\n"));
+		    "\tsend [-PnVv] --saved filesystem\n"));
 	case HELP_SET:
 		return (gettext("\tset <property=value> ... "
 		    "<filesystem|volume|snapshot> ...\n"));
@@ -4437,6 +4437,7 @@ zfs_do_send(int argc, char **argv)
 		{"props",	no_argument,		NULL, 'p'},
 		{"parsable",	no_argument,		NULL, 'P'},
 		{"dedup",	no_argument,		NULL, 'D'},
+		{"proctitle",	no_argument,		NULL, 'V'},
 		{"verbose",	no_argument,		NULL, 'v'},
 		{"dryrun",	no_argument,		NULL, 'n'},
 		{"large-block",	no_argument,		NULL, 'L'},
@@ -4451,7 +4452,7 @@ zfs_do_send(int argc, char **argv)
 	};
 
 	/* check options */
-	while ((c = getopt_long(argc, argv, ":i:I:RsDpvnPLeht:cwbd:S",
+	while ((c = getopt_long(argc, argv, ":i:I:RsDpVvnPLeht:cwbd:S",
 	    long_options, NULL)) != -1) {
 		switch (c) {
 		case 'i':
@@ -4486,6 +4487,9 @@ zfs_do_send(int argc, char **argv)
 		case 'P':
 			flags.parsable = B_TRUE;
 			break;
+		case 'V':
+			flags.progressastitle = B_TRUE;
+			break;
 		case 'v':
 			flags.verbosity++;
 			flags.progress = B_TRUE;
@@ -8664,6 +8668,7 @@ main(int argc, char **argv)
 	int i = 0;
 	char *cmdname;
 	char **newargv;
+	extern char **environ;
 
 	(void) setlocale(LC_ALL, "");
 	(void) setlocale(LC_NUMERIC, "C");
@@ -8723,6 +8728,8 @@ main(int argc, char **argv)
 
 	libzfs_print_on_error(g_zfs, B_TRUE);
 
+	zfs_setproctitle_init(argc, argv, environ);
+
 	/*
 	 * Many commands modify input strings for string parsing reasons.
 	 * We create a copy to protect the original argv.

include/libzfs.h

@@ -693,6 +693,9 @@ typedef struct sendflags {
 	/* show progress (ie. -v) */
 	boolean_t progress;
 
+	/* show progress as process title (ie. -V) */
+	boolean_t progressastitle;
+
 	/* large blocks (>128K) are permitted */
 	boolean_t largeblock;
 

include/libzutil.h

@@ -167,6 +167,14 @@ void color_start(const char *color);
 void color_end(void);
 int printf_color(const char *color, char *format, ...);
 
+#ifdef __linux__
+_LIBZUTIL_H void zfs_setproctitle_init(int argc, char *argv[], char *envp[]);
+_LIBZUTIL_H void zfs_setproctitle(const char *fmt, ...);
+#else
+#define	zfs_setproctitle(fmt, ...)	setproctitle(fmt, ##__VA_ARGS__)
+#define	zfs_setproctitle_init(x, y, z)	((void)0)
+#endif
+
 /*
  * These functions are used by the ZFS libraries and cmd/zpool code, but are
  * not exported in the ABI.

lib/libzfs/libzfs.abi

@@ -6104,7 +6104,7 @@
     <array-type-def dimensions='1' type-id='b96825af' size-in-bits='64' id='13339fda'>
       <subrange length='8' type-id='7359adad' id='56e0c0b1'/>
     </array-type-def>
-    <class-decl name='sendflags' size-in-bits='544' is-struct='yes' visibility='default' id='f6aa15be'>
+    <class-decl name='sendflags' size-in-bits='576' is-struct='yes' visibility='default' id='f6aa15be'>
       <data-member access='public' layout-offset-in-bits='0'>
         <var-decl name='verbosity' type-id='95e97e5e' visibility='default'/>
       </data-member>
@@ -6136,24 +6136,27 @@
         <var-decl name='progress' type-id='c19b74c3' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='320'>
-        <var-decl name='largeblock' type-id='c19b74c3' visibility='default'/>
+        <var-decl name='progressastitle' type-id='c19b74c3' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='352'>
-        <var-decl name='embed_data' type-id='c19b74c3' visibility='default'/>
+        <var-decl name='largeblock' type-id='c19b74c3' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='384'>
-        <var-decl name='compress' type-id='c19b74c3' visibility='default'/>
+        <var-decl name='embed_data' type-id='c19b74c3' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='416'>
-        <var-decl name='raw' type-id='c19b74c3' visibility='default'/>
+        <var-decl name='compress' type-id='c19b74c3' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='448'>
-        <var-decl name='backup' type-id='c19b74c3' visibility='default'/>
+        <var-decl name='raw' type-id='c19b74c3' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='480'>
-        <var-decl name='holds' type-id='c19b74c3' visibility='default'/>
+        <var-decl name='backup' type-id='c19b74c3' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='512'>
+        <var-decl name='holds' type-id='c19b74c3' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='544'>
         <var-decl name='saved' type-id='c19b74c3' visibility='default'/>
       </data-member>
     </class-decl>
@@ -6734,6 +6737,11 @@
       <parameter type-id='95e97e5e'/>
       <return type-id='48b5725f'/>
     </function-decl>
+    <function-decl name='zfs_setproctitle' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='80f4b756'/>
+      <parameter is-variadic='yes'/>
+      <return type-id='48b5725f'/>
+    </function-decl>
     <function-decl name='avl_insert' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='a3681dea'/>
       <parameter type-id='eaa32e2f'/>

lib/libzfs/libzfs_sendrecv.c

@@ -83,6 +83,8 @@ typedef struct progress_arg {
 	boolean_t pa_parsable;
 	boolean_t pa_estimate;
 	int pa_verbosity;
+	boolean_t pa_astitle;
+	uint64_t pa_size;
 } progress_arg_t;
 
 static int
@@ -712,6 +714,7 @@ typedef struct send_dump_data {
 	boolean_t seenfrom, seento, replicate, doall, fromorigin;
 	boolean_t dryrun, parsable, progress, embed_data, std_out;
 	boolean_t large_block, compress, raw, holds;
+	boolean_t progressastitle;
 	int outfd;
 	boolean_t err;
 	nvlist_t *fss;
@@ -904,6 +907,7 @@ send_progress_thread(void *arg)
 	zfs_handle_t *zhp = pa->pa_zhp;
 	uint64_t bytes;
 	uint64_t blocks;
+	uint64_t total = pa->pa_size / 100;
 	char buf[16];
 	time_t t;
 	struct tm *tm;
@@ -922,7 +926,7 @@ send_progress_thread(void *arg)
 			return ((void *)(uintptr_t)err);
 		}
 
-		if (firstloop && !pa->pa_parsable) {
+		if (firstloop && !pa->pa_parsable && pa->pa_verbosity != 0) {
 			(void) fprintf(stderr,
 			    "TIME       %s   %sSNAPSHOT %s\n",
 			    pa->pa_estimate ? "BYTES" : " SENT",
@@ -934,6 +938,17 @@ send_progress_thread(void *arg)
 		(void) time(&t);
 		tm = localtime(&t);
 
+		if (pa->pa_astitle) {
+			char buf_bytes[16];
+			char buf_size[16];
+			int pct;
+			zfs_nicenum(bytes, buf_bytes, sizeof (buf_bytes));
+			zfs_nicenum(pa->pa_size, buf_size, sizeof (buf_size));
+			pct = (total > 0) ? bytes / total : 100;
+			zfs_setproctitle("sending %s (%d%%: %s/%s)",
+			    zhp->zfs_name, MIN(pct, 100), buf_bytes, buf_size);
+		}
+
 		if (pa->pa_verbosity >= 2 && pa->pa_parsable) {
 			(void) fprintf(stderr,
 			    "%02d:%02d:%02d\t%llu\t%llu\t%s\n",
@@ -950,7 +965,7 @@ send_progress_thread(void *arg)
 			(void) fprintf(stderr, "%02d:%02d:%02d\t%llu\t%s\n",
 			    tm->tm_hour, tm->tm_min, tm->tm_sec,
 			    (u_longlong_t)bytes, zhp->zfs_name);
-		} else {
+		} else if (pa->pa_verbosity != 0) {
 			zfs_nicebytes(bytes, buf, sizeof (buf));
 			(void) fprintf(stderr, "%02d:%02d:%02d   %5s   %s\n",
 			    tm->tm_hour, tm->tm_min, tm->tm_sec,
@@ -1114,12 +1129,14 @@ dump_snapshot(zfs_handle_t *zhp, void *arg)
 		 * If progress reporting is requested, spawn a new thread to
 		 * poll ZFS_IOC_SEND_PROGRESS at a regular interval.
 		 */
-		if (sdd->progress) {
+		if (sdd->progress || sdd->progressastitle) {
 			pa.pa_zhp = zhp;
 			pa.pa_fd = sdd->outfd;
 			pa.pa_parsable = sdd->parsable;
 			pa.pa_estimate = B_FALSE;
 			pa.pa_verbosity = sdd->verbosity;
+			pa.pa_size = sdd->size;
+			pa.pa_astitle = sdd->progressastitle;
 
 			if ((err = pthread_create(&tid, NULL,
 			    send_progress_thread, &pa)) != 0) {
@@ -1131,7 +1148,7 @@ dump_snapshot(zfs_handle_t *zhp, void *arg)
 		err = dump_ioctl(zhp, sdd->prevsnap, sdd->prevsnap_obj,
 		    fromorigin, sdd->outfd, flags, sdd->debugnv);
 
-		if (sdd->progress) {
+		if (sdd->progress || sdd->progressastitle) {
 			void *status = NULL;
 			(void) pthread_cancel(tid);
 			(void) pthread_join(tid, &status);
@@ -1462,7 +1479,7 @@ lzc_flags_from_sendflags(const sendflags_t *flags)
 static int
 estimate_size(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
     uint64_t resumeobj, uint64_t resumeoff, uint64_t bytes,
-    const char *redactbook, char *errbuf)
+    const char *redactbook, char *errbuf, uint64_t *sizep)
 {
 	uint64_t size;
 	FILE *fout = flags->dryrun ? stdout : stderr;
@@ -1470,7 +1487,7 @@ estimate_size(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 	int err = 0;
 	pthread_t ptid;
 
-	if (flags->progress) {
+	if (flags->progress || flags->progressastitle) {
 		pa.pa_zhp = zhp;
 		pa.pa_fd = fd;
 		pa.pa_parsable = flags->parsable;
@@ -1489,8 +1506,9 @@ estimate_size(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 	err = lzc_send_space_resume_redacted(zhp->zfs_name, from,
 	    lzc_flags_from_sendflags(flags), resumeobj, resumeoff, bytes,
 	    redactbook, fd, &size);
+	*sizep = size;
 
-	if (flags->progress) {
+	if (flags->progress || flags->progressastitle) {
 		void *status = NULL;
 		(void) pthread_cancel(ptid);
 		(void) pthread_join(ptid, &status);
@@ -1505,6 +1523,9 @@ estimate_size(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 		}
 	}
 
+	if (!flags->progress && !flags->parsable)
+		return (err);
+
 	if (err != 0) {
 		zfs_error_aux(zhp->zfs_hdl, "%s", strerror(err));
 		return (zfs_error(zhp->zfs_hdl, EZFS_BADBACKUP,
@@ -1638,6 +1659,7 @@ zfs_send_resume_impl(libzfs_handle_t *hdl, sendflags_t *flags, int outfd,
 	uint64_t *redact_snap_guids = NULL;
 	int num_redact_snaps = 0;
 	char *redact_book = NULL;
+	uint64_t size = 0;
 
 	(void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
 	    "cannot resume send"));
@@ -1731,7 +1753,7 @@ zfs_send_resume_impl(libzfs_handle_t *hdl, sendflags_t *flags, int outfd,
 		}
 	}
 
-	if (flags->verbosity != 0) {
+	if (flags->verbosity != 0 || flags->progressastitle) {
 		/*
 		 * Some of these may have come from the resume token, set them
 		 * here for size estimate purposes.
@@ -1748,7 +1770,7 @@ zfs_send_resume_impl(libzfs_handle_t *hdl, sendflags_t *flags, int outfd,
 		if (lzc_flags & LZC_SEND_FLAG_SAVED)
 			tmpflags.saved = B_TRUE;
 		error = estimate_size(zhp, fromname, outfd, &tmpflags,
-		    resumeobj, resumeoff, bytes, redact_book, errbuf);
+		    resumeobj, resumeoff, bytes, redact_book, errbuf, &size);
 	}
 
 	if (!flags->dryrun) {
@@ -1758,12 +1780,14 @@ zfs_send_resume_impl(libzfs_handle_t *hdl, sendflags_t *flags, int outfd,
 		 * If progress reporting is requested, spawn a new thread to
 		 * poll ZFS_IOC_SEND_PROGRESS at a regular interval.
 		 */
-		if (flags->progress) {
+		if (flags->progress || flags->progressastitle) {
 			pa.pa_zhp = zhp;
 			pa.pa_fd = outfd;
 			pa.pa_parsable = flags->parsable;
 			pa.pa_estimate = B_FALSE;
 			pa.pa_verbosity = flags->verbosity;
+			pa.pa_size = size;
+			pa.pa_astitle = flags->progressastitle;
 
 			error = pthread_create(&tid, NULL,
 			    send_progress_thread, &pa);
@@ -1780,7 +1804,7 @@ zfs_send_resume_impl(libzfs_handle_t *hdl, sendflags_t *flags, int outfd,
 		if (redact_book != NULL)
 			free(redact_book);
 
-		if (flags->progress) {
+		if (flags->progress || flags->progress) {
 			void *status = NULL;
 			(void) pthread_cancel(tid);
 			(void) pthread_join(tid, &status);
@@ -1790,6 +1814,7 @@ zfs_send_resume_impl(libzfs_handle_t *hdl, sendflags_t *flags, int outfd,
 				(void) snprintf(errbuf, sizeof (errbuf),
 				    dgettext(TEXT_DOMAIN,
 				    "progress thread exited nonzero"));
+				zfs_close(zhp);
 				return (zfs_standard_error(hdl, error, errbuf));
 			}
 		}
@@ -2199,6 +2224,7 @@ zfs_send(zfs_handle_t *zhp, const char *fromsnap, const char *tosnap,
 	sdd.verbosity = flags->verbosity;
 	sdd.parsable = flags->parsable;
 	sdd.progress = flags->progress;
+	sdd.progressastitle = flags->progressastitle;
 	sdd.dryrun = flags->dryrun;
 	sdd.large_block = flags->largeblock;
 	sdd.embed_data = flags->embed_data;
@@ -2410,6 +2436,7 @@ zfs_send_one(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 	char *name = zhp->zfs_name;
 	pthread_t ptid;
 	progress_arg_t pa = { 0 };
+	uint64_t size = 0;
 
 	char errbuf[1024];
 	(void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
@@ -2492,9 +2519,9 @@ zfs_send_one(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 	/*
 	 * Perform size estimate if verbose was specified.
 	 */
-	if (flags->verbosity != 0) {
+	if (flags->verbosity != 0 || flags->progressastitle) {
 		err = estimate_size(zhp, from, fd, flags, 0, 0, 0, redactbook,
-		    errbuf);
+		    errbuf, &size);
 		if (err != 0)
 			return (err);
 	}
@@ -2506,12 +2533,14 @@ zfs_send_one(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 	 * If progress reporting is requested, spawn a new thread to poll
 	 * ZFS_IOC_SEND_PROGRESS at a regular interval.
 	 */
-	if (flags->progress) {
+	if (flags->progress || flags->progressastitle) {
 		pa.pa_zhp = zhp;
 		pa.pa_fd = fd;
 		pa.pa_parsable = flags->parsable;
 		pa.pa_estimate = B_FALSE;
 		pa.pa_verbosity = flags->verbosity;
+		pa.pa_size = size;
+		pa.pa_astitle = flags->progressastitle;
 
 		err = pthread_create(&ptid, NULL,
 		    send_progress_thread, &pa);
@@ -2525,7 +2554,7 @@ zfs_send_one(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 	err = lzc_send_redacted(name, from, fd,
 	    lzc_flags_from_sendflags(flags), redactbook);
 
-	if (flags->progress) {
+	if (flags->progress || flags->progressastitle) {
 		void *status = NULL;
 		(void) pthread_cancel(ptid);
 		(void) pthread_join(ptid, &status);

lib/libzfs_core/libzfs_core.abi

@@ -272,6 +272,8 @@
     <elf-symbol name='zfs_niceraw' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_nicetime' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_resolve_shortname' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='zfs_setproctitle' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='zfs_setproctitle_init' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_strcmp_pathname' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_strip_partition' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_strip_path' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
@@ -3340,6 +3342,30 @@
       <return type-id='95e97e5e'/>
     </function-decl>
   </abi-instr>
+  <abi-instr address-size='64' path='os/linux/zutil_setproctitle.c' language='LANG_C99'>
+    <function-decl name='warnx' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='80f4b756'/>
+      <parameter is-variadic='yes'/>
+      <return type-id='48b5725f'/>
+    </function-decl>
+    <function-decl name='setenv' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='80f4b756'/>
+      <parameter type-id='80f4b756'/>
+      <parameter type-id='95e97e5e'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
+    <function-decl name='zfs_setproctitle_init' mangled-name='zfs_setproctitle_init' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zfs_setproctitle_init'>
+      <parameter type-id='95e97e5e' name='argc'/>
+      <parameter type-id='9b23c9ad' name='argv'/>
+      <parameter type-id='9b23c9ad' name='envp'/>
+      <return type-id='48b5725f'/>
+    </function-decl>
+    <function-decl name='zfs_setproctitle' mangled-name='zfs_setproctitle' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zfs_setproctitle'>
+      <parameter type-id='80f4b756' name='fmt'/>
+      <parameter is-variadic='yes'/>
+      <return type-id='48b5725f'/>
+    </function-decl>
+  </abi-instr>
   <abi-instr address-size='64' path='zutil_device_path.c' language='LANG_C99'>
     <qualified-type-def type-id='26a90f95' restrict='yes' id='266fe297'/>
     <qualified-type-def type-id='80f4b756' const='yes' id='b99c00c9'/>

lib/libzutil/Makefile.am

@@ -18,6 +18,7 @@ USER_C = \
 
 if BUILD_LINUX
 USER_C += \
+	os/linux/zutil_setproctitle.c \
 	os/linux/zutil_device_path_os.c \
 	os/linux/zutil_import_os.c \
 	os/linux/zutil_compat.c

lib/libzutil/os/linux/zutil_setproctitle.c

@@ -0,0 +1,299 @@
+/*
+ * Copyright © 2013 Guillem Jover <guillem@hadrons.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <err.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/param.h>
+#include <libzutil.h>
+
+static struct {
+	/* Original value. */
+	const char *arg0;
+
+	/* Title space available. */
+	char *base, *end;
+
+	/* Pointer to original nul character within base. */
+	char *nul;
+
+	boolean_t warned;
+	boolean_t reset;
+	int error;
+} SPT;
+
+#define	LIBBSD_IS_PATHNAME_SEPARATOR(c) ((c) == '/')
+#define	SPT_MAXTITLE 255
+
+extern const char *__progname;
+
+static const char *
+getprogname(void)
+{
+	return (__progname);
+}
+
+static void
+setprogname(const char *progname)
+{
+	size_t i;
+
+	for (i = strlen(progname); i > 0; i--) {
+		if (LIBBSD_IS_PATHNAME_SEPARATOR(progname[i - 1])) {
+			__progname = progname + i;
+			return;
+		}
+	}
+	__progname = progname;
+}
+
+
+static inline size_t
+spt_min(size_t a, size_t b)
+{
+	return ((a < b) ? a : b);
+}
+
+/*
+ * For discussion on the portability of the various methods, see
+ * https://lists.freebsd.org/pipermail/freebsd-stable/2008-June/043136.html
+ */
+static int
+spt_clearenv(void)
+{
+	char **tmp;
+
+	tmp = malloc(sizeof (*tmp));
+	if (tmp == NULL)
+		return (errno);
+
+	tmp[0] = NULL;
+	environ = tmp;
+
+	return (0);
+}
+
+static int
+spt_copyenv(int envc, char *envp[])
+{
+	char **envcopy;
+	char *eq;
+	int envsize;
+	int i, error;
+
+	if (environ != envp)
+		return (0);
+
+	/*
+	 * Make a copy of the old environ array of pointers, in case
+	 * clearenv() or setenv() is implemented to free the internal
+	 * environ array, because we will need to access the old environ
+	 * contents to make the new copy.
+	 */
+	envsize = (envc + 1) * sizeof (char *);
+	envcopy = malloc(envsize);
+	if (envcopy == NULL)
+		return (errno);
+	memcpy(envcopy, envp, envsize);
+
+	error = spt_clearenv();
+	if (error) {
+		environ = envp;
+		free(envcopy);
+		return (error);
+	}
+
+	for (i = 0; envcopy[i]; i++) {
+		eq = strchr(envcopy[i], '=');
+		if (eq == NULL)
+			continue;
+
+		*eq = '\0';
+		if (setenv(envcopy[i], eq + 1, 1) < 0)
+			error = errno;
+		*eq = '=';
+
+		if (error) {
+			environ = envp;
+			free(envcopy);
+			return (error);
+		}
+	}
+
+	/*
+	 * Dispose of the shallow copy, now that we've finished transfering
+	 * the old environment.
+	 */
+	free(envcopy);
+
+	return (0);
+}
+
+static int
+spt_copyargs(int argc, char *argv[])
+{
+	char *tmp;
+	int i;
+
+	for (i = 1; i < argc || (i >= argc && argv[i]); i++) {
+		if (argv[i] == NULL)
+			continue;
+
+		tmp = strdup(argv[i]);
+		if (tmp == NULL)
+			return (errno);
+
+		argv[i] = tmp;
+	}
+
+	return (0);
+}
+
+void
+zfs_setproctitle_init(int argc, char *argv[], char *envp[])
+{
+	char *base, *end, *nul, *tmp;
+	int i, envc, error;
+
+	/* Try to make sure we got called with main() arguments. */
+	if (argc < 0)
+		return;
+
+	base = argv[0];
+	if (base == NULL)
+		return;
+
+	nul = base + strlen(base);
+	end = nul + 1;
+
+	for (i = 0; i < argc || (i >= argc && argv[i]); i++) {
+		if (argv[i] == NULL || argv[i] != end)
+			continue;
+
+		end = argv[i] + strlen(argv[i]) + 1;
+	}
+
+	for (i = 0; envp[i]; i++) {
+		if (envp[i] != end)
+			continue;
+
+		end = envp[i] + strlen(envp[i]) + 1;
+	}
+	envc = i;
+
+	SPT.arg0 = strdup(argv[0]);
+	if (SPT.arg0 == NULL) {
+		SPT.error = errno;
+		return;
+	}
+
+	tmp = strdup(getprogname());
+	if (tmp == NULL) {
+		SPT.error = errno;
+		return;
+	}
+	setprogname(tmp);
+
+	error = spt_copyenv(envc, envp);
+	if (error) {
+		SPT.error = error;
+		return;
+	}
+
+	error = spt_copyargs(argc, argv);
+	if (error) {
+		SPT.error = error;
+		return;
+	}
+
+	SPT.nul  = nul;
+	SPT.base = base;
+	SPT.end  = end;
+}
+
+void
+zfs_setproctitle(const char *fmt, ...)
+{
+	/* Use buffer in case argv[0] is passed. */
+	char buf[SPT_MAXTITLE + 1];
+	va_list ap;
+	char *nul;
+	int len;
+	if (SPT.base == NULL) {
+		if (!SPT.warned) {
+			warnx("setproctitle not initialized, please"
+			    "call zfs_setproctitle_init()");
+			SPT.warned = B_TRUE;
+		}
+		return;
+	}
+
+	if (fmt) {
+		if (fmt[0] == '-') {
+			/* Skip program name prefix. */
+			fmt++;
+			len = 0;
+		} else {
+			/* Print program name heading for grep. */
+			snprintf(buf, sizeof (buf), "%s: ", getprogname());
+			len = strlen(buf);
+		}
+
+		va_start(ap, fmt);
+		len += vsnprintf(buf + len, sizeof (buf) - len, fmt, ap);
+		va_end(ap);
+	} else {
+		len = snprintf(buf, sizeof (buf), "%s", SPT.arg0);
+	}
+
+	if (len <= 0) {
+		SPT.error = errno;
+		return;
+	}
+
+	if (!SPT.reset) {
+		memset(SPT.base, 0, SPT.end - SPT.base);
+		SPT.reset = B_TRUE;
+	} else {
+		memset(SPT.base, 0, spt_min(sizeof (buf), SPT.end - SPT.base));
+	}
+
+	len = spt_min(len, spt_min(sizeof (buf), SPT.end - SPT.base) - 1);
+	memcpy(SPT.base, buf, len);
+	nul = SPT.base + len;
+
+	if (nul < SPT.nul) {
+		*SPT.nul = '.';
+	} else if (nul == SPT.nul && nul + 1 < SPT.end) {
+		*SPT.nul = ' ';
+		*++nul = '\0';
+	}
+}

man/man8/zfs-send.8

@@ -29,7 +29,7 @@
 .\" Copyright 2018 Nexenta Systems, Inc.
 .\" Copyright 2019 Joyent, Inc.
 .\"
-.Dd April 15, 2021
+.Dd January 12, 2023
 .Dt ZFS-SEND 8
 .Os
 .
@@ -39,28 +39,28 @@
 .Sh SYNOPSIS
 .Nm zfs
 .Cm send
-.Op Fl DLPRbcehnpsvw
+.Op Fl DLPVRbcehnpsvw
 .Op Oo Fl I Ns | Ns Fl i Oc Ar snapshot
 .Ar snapshot
 .Nm zfs
 .Cm send
-.Op Fl DLPcensvw
+.Op Fl DLPVcensvw
 .Op Fl i Ar snapshot Ns | Ns Ar bookmark
 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot
 .Nm zfs
 .Cm send
 .Fl -redact Ar redaction_bookmark
-.Op Fl DLPcenpv
+.Op Fl DLPVcenpv
 .Op Fl i Ar snapshot Ns | Ns Ar bookmark
 .Ar snapshot
 .Nm zfs
 .Cm send
-.Op Fl Penv
+.Op Fl PVenv
 .Fl t
 .Ar receive_resume_token
 .Nm zfs
 .Cm send
-.Op Fl Pnv
+.Op Fl PVnv
 .Fl S Ar filesystem
 .Nm zfs
 .Cm redact
@@ -72,7 +72,7 @@
 .It Xo
 .Nm zfs
 .Cm send
-.Op Fl DLPRbcehnpvw
+.Op Fl DLPVRbcehnpvw
 .Op Oo Fl I Ns | Ns Fl i Oc Ar snapshot
 .Ar snapshot
 .Xc
@@ -140,6 +140,8 @@ If the
 flag is used to send encrypted datasets, then
 .Fl w
 must also be specified.
+.It Fl V , -proctitle
+Set the process title to a per-second report of how much data has been sent.
 .It Fl e , -embed
 Generate a more compact stream by using
 .Sy WRITE_EMBEDDED
@@ -285,7 +287,7 @@ You will be able to receive your streams on future versions of ZFS.
 .It Xo
 .Nm zfs
 .Cm send
-.Op Fl DLPcenvw
+.Op Fl DLPVcenvw
 .Op Fl i Ar snapshot Ns | Ns Ar bookmark
 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot
 .Xc
@@ -417,7 +419,7 @@ This information includes a per-second report of how much data has been sent.
 .Nm zfs
 .Cm send
 .Fl -redact Ar redaction_bookmark
-.Op Fl DLPcenpv
+.Op Fl DLPVcenpv
 .Op Fl i Ar snapshot Ns | Ns Ar bookmark
 .Ar snapshot
 .Xc
@@ -511,7 +513,7 @@ raw sends and redacted sends cannot be combined at this time.
 .It Xo
 .Nm zfs
 .Cm send
-.Op Fl Penv
+.Op Fl PVenv
 .Fl t
 .Ar receive_resume_token
 .Xc
@@ -526,7 +528,7 @@ for more details.
 .It Xo
 .Nm zfs
 .Cm send
-.Op Fl Pnv
+.Op Fl PVnv
 .Op Fl i Ar snapshot Ns | Ns Ar bookmark
 .Fl S
 .Ar filesystem

tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_006_pos.ksh

@@ -119,33 +119,33 @@ full_size=$(zfs send $full_snapshot 2>&1 | wc -c)
 incremental_size=$(zfs send $incremental_snapshot 2>&1 | wc -c)
 incremental_send=$(zfs send -i $full_snapshot $incremental_snapshot 2>&1 | wc -c)
 
-log_note "verify zfs send -nv"
+log_note "verify zfs send -nvV"
-options="-nv"
+options="-nvV"
 refer_size=$(get_prop refer $full_snapshot)
 estimate_size=$(get_estimate_size $full_snapshot $options)
 log_must verify_size_estimates $options $full_size
 
-log_note "verify zfs send -Pnv"
+log_note "verify zfs send -PnvV"
-options="-Pnv"
+options="-PnvV"
 
 estimate_size=$(get_estimate_size $full_snapshot $options)
 log_must verify_size_estimates $options $full_size
 
-log_note "verify zfs send -nv for multiple snapshot send"
+log_note "verify zfs send -nvV for multiple snapshot send"
-options="-nv"
+options="-nvV"
 refer_size=$(get_prop refer $incremental_snapshot)
 
 estimate_size=$(get_estimate_size $incremental_snapshot $options)
 log_must verify_size_estimates $options $incremental_size
 
-log_note "verify zfs send -vPn for multiple snapshot send"
+log_note "verify zfs send -vVPn for multiple snapshot send"
-options="-vPn"
+options="-vVPn"
 
 estimate_size=$(get_estimate_size $incremental_snapshot $options)
 log_must verify_size_estimates $options $incremental_size
 
-log_note "verify zfs send -inv for incremental send"
+log_note "verify zfs send -invV for incremental send"
-options="-nvi"
+options="-nvVi"
 refer_size=$(get_prop refer $incremental_snapshot)
 deduct_size=$(get_prop refer $full_snapshot)
 refer_size=$(echo "$refer_size - $deduct_size" | bc)
@@ -155,8 +155,8 @@ log_must verify_size_estimates $options $incremental_send
 estimate_size=$(get_estimate_size $incremental_snapshot $options $full_bookmark)
 log_must verify_size_estimates $options $incremental_send
 
-log_note "verify zfs send -ivPn for incremental send"
+log_note "verify zfs send -ivVPn for incremental send"
-options="-vPni"
+options="-vVPni"
 
 estimate_size=$(get_estimate_size $incremental_snapshot $options $full_snapshot)
 log_must verify_size_estimates $options $incremental_send
@@ -186,16 +186,16 @@ for ds in $datasets; do
         datasetexists $ds@snap64 || log_fail "Create $ds@snap64 snapshot fail."
 done
 recursive_size=$(zfs send -R $full_snapshot 2>&1 | wc -c)
-log_note "verify zfs send -Rnv for recursive send"
+log_note "verify zfs send -RnvV for recursive send"
-options="-Rnv"
+options="-RnvV"
 refer_size=$(get_prop refer $full_snapshot)
 refer_size=$(echo "$refer_size * 3" | bc)
 
 estimate_size=$(get_estimate_size $full_snapshot $options)
 log_must verify_size_estimates $options $recursive_size
 
-log_note "verify zfs send -RvPn for recursive send"
+log_note "verify zfs send -RvVPn for recursive send"
-options="-RvPn"
+options="-RvVPn"
 estimate_size=$(get_estimate_size $full_snapshot $options)
 log_must verify_size_estimates $options $recursive_size