Allow 'zfs holds -r' to recurse over a file system or volume to find holds

Previously, the parameters of 'zfs holds' could only be snapshots

Add -d <depth> flag to limit depth of recursion
Add -p flag to print literal values, rather than interpreted values
Add -H flag to suppress header output and use tabs rather than whitespace

Reviewed by:	mahrens, smh, dteske
Approved by:	bapt (mentor)
MFC after:	3 weeks
Relnotes:	yes
Sponsored by:	ScaleEngine Inc.
Differential Revision:	https://reviews.freebsd.org/D3994

2 files changed, 55 insertions, 28 deletions

diff --git a/cddl/contrib/opensolaris/cmd/zfs/zfs.8 b/cddl/contrib/opensolaris/cmd/zfs/zfs.8
index 5eca00f..418f253 100644
--- a/cddl/contrib/opensolaris/cmd/zfs/zfs.8
+++ b/cddl/contrib/opensolaris/cmd/zfs/zfs.8
@@ -31,7 +31,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd September 14, 2015
+.Dd October 24, 2015
 .Dt ZFS 8
 .Os
 .Sh NAME
@@ -272,8 +272,10 @@
 .Ar tag snapshot Ns ...
 .Nm
 .Cm holds
-.Op Fl r
-.Ar snapshot Ns ...
+.Op Fl Hp
+.Op Fl r Ns | Ns Fl d Ar depth
+.Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot Ns
+.Ns ...
 .Nm
 .Cm release
 .Op Fl r
@@ -3159,15 +3161,26 @@ snapshots of all descendent file systems.
 .It Xo
 .Nm
 .Cm holds
-.Op Fl r
-.Ar snapshot Ns ...
+.Op Fl Hp
+.Op Fl r Ns | Ns Fl d Ar depth
+.Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot Ns
+.Ns ...
 .Xc
 .Pp
-Lists all existing user references for the given snapshot or snapshots.
+Lists all existing user references for the given dataset or datasets.
 .Bl -tag -width indent
+.It Fl H
+Used for scripting mode. Do not print headers and separate fields by a single
+tab instead of arbitrary white space.
+.It Fl p
+Display numbers in parsable (exact) values.
 .It Fl r
-Lists the holds that are set on the named descendent snapshots, in addition to
-listing the holds on the named snapshot.
+Lists the holds that are set on the descendent snapshots of the named datasets
+or snapshots, in addition to listing the holds on the named snapshots, if any.
+.It Fl d Ar depth
+Recursively display any holds on the named snapshots, or descendent snapshots of
+the named datasets or snapshots, limiting the recursion to
+.Ar depth .
 .El
 .It Xo
 .Nm
diff --git a/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c b/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c
index b8466fe..9db2f73 100644
--- a/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c
+++ b/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c
@@ -329,7 +329,8 @@ get_usage(zfs_help_t idx)
 	case HELP_HOLD:
 		return (gettext("\thold [-r] <tag> <snapshot> ...\n"));
 	case HELP_HOLDS:
-		return (gettext("\tholds [-r] <snapshot> ...\n"));
+		return (gettext("\tholds [-Hp] [-r|-d depth] "
+		    "<filesystem|volume|snapshot> ...\n"));
 	case HELP_RELEASE:
 		return (gettext("\trelease [-r] <tag> <snapshot> ...\n"));
 	case HELP_DIFF:
@@ -5543,7 +5544,8 @@ typedef struct holds_cbdata {
  *
  */
 static void
-print_holds(boolean_t scripted, size_t nwidth, size_t tagwidth, nvlist_t *nvl)
+print_holds(boolean_t scripted, boolean_t literal, size_t nwidth,
+    size_t tagwidth, nvlist_t *nvl)
 {
 	int i;
 	nvpair_t *nvp = NULL;
@@ -5576,10 +5578,14 @@ print_holds(boolean_t scripted, size_t nwidth, size_t tagwidth, nvlist_t *nvl)
 			size_t sepnum = scripted ? 1 : 2;
 
 			(void) nvpair_value_uint64(nvp2, &val);
-			time = (time_t)val;
-			(void) localtime_r(&time, &t);
-			(void) strftime(tsbuf, DATETIME_BUF_LEN,
-			    gettext(STRFTIME_FMT_STR), &t);
+			if (literal)
+				snprintf(tsbuf, DATETIME_BUF_LEN, "%llu", val);
+			else {
+				time = (time_t)val;
+				(void) localtime_r(&time, &t);
+				(void) strftime(tsbuf, DATETIME_BUF_LEN,
+				    gettext(STRFTIME_FMT_STR), &t);
+			}
 
 			(void) printf("%-*s%*c%-*s%*c%s\n", nwidth, zname,
 			    sepnum, sep, tagwidth, tagname, sepnum, sep, tsbuf);
@@ -5600,7 +5606,7 @@ holds_callback(zfs_handle_t *zhp, void *data)
 	const char *zname = zfs_get_name(zhp);
 	size_t znamelen = strnlen(zname, ZFS_MAXNAMELEN);
 
-	if (cbp->cb_recursive) {
+	if (cbp->cb_recursive && cbp->cb_snapname != NULL) {
 		const char *snapname;
 		char *delim  = strchr(zname, '@');
 		if (delim == NULL)
@@ -5628,9 +5634,12 @@ holds_callback(zfs_handle_t *zhp, void *data)
 }
 
 /*
- * zfs holds [-r] <snap> ...
+ * zfs holds [-Hp] [-r | -d max] <dataset|snap> ...
  *
- *	-r	Recursively hold
+ *	-H	Suppress header output
+ *	-p	Output literal values
+ *	-r	Recursively search for holds
+ *	-d max	Limit depth of recursive search
  */
 static int
 zfs_do_holds(int argc, char **argv)
@@ -5639,8 +5648,9 @@ zfs_do_holds(int argc, char **argv)
 	int c;
 	int i;
 	boolean_t scripted = B_FALSE;
+	boolean_t literal = B_FALSE;
 	boolean_t recursive = B_FALSE;
-	const char *opts = "rH";
+	const char *opts = "d:rHp";
 	nvlist_t *nvl;
 
 	int types = ZFS_TYPE_SNAPSHOT;
@@ -5653,12 +5663,19 @@ zfs_do_holds(int argc, char **argv)
 	/* check options */
 	while ((c = getopt(argc, argv, opts)) != -1) {
 		switch (c) {
+		case 'd':
+			limit = parse_depth(optarg, &flags);
+			recursive = B_TRUE;
+			break;
 		case 'r':
 			recursive = B_TRUE;
 			break;
 		case 'H':
 			scripted = B_TRUE;
 			break;
+		case 'p':
+			literal = B_TRUE;
+			break;
 		case '?':
 			(void) fprintf(stderr, gettext("invalid option '%c'\n"),
 			    optopt);
@@ -5684,18 +5701,14 @@ zfs_do_holds(int argc, char **argv)
 	for (i = 0; i < argc; ++i) {
 		char *snapshot = argv[i];
 		const char *delim;
-		const char *snapname;
+		const char *snapname = NULL;
 
 		delim = strchr(snapshot, '@');
-		if (delim == NULL) {
-			(void) fprintf(stderr,
-			    gettext("'%s' is not a snapshot\n"), snapshot);
-			++errors;
-			continue;
+		if (delim != NULL) {
+			snapname = delim + 1;
+			if (recursive)
+				snapshot[delim - snapshot] = '\0';
 		}
-		snapname = delim + 1;
-		if (recursive)
-			snapshot[delim - snapshot] = '\0';
 
 		cb.cb_recursive = recursive;
 		cb.cb_snapname = snapname;
@@ -5713,7 +5726,8 @@ zfs_do_holds(int argc, char **argv)
 	/*
 	 *  2. print holds data
 	 */
-	print_holds(scripted, cb.cb_max_namelen, cb.cb_max_taglen, nvl);
+	print_holds(scripted, literal, cb.cb_max_namelen, cb.cb_max_taglen,
+	    nvl);
 
 	if (nvlist_empty(nvl))
 		(void) printf(gettext("no datasets available\n"));