gnop: Introduce requests delay.

This allows to simulated disk that is responding slowly to the IO requests.

Reviewed by:	markj, bcr, pjd (previous version)
Differential Revision:	https://reviews.freebsd.org/D21052

2 files changed, 25 insertions, 5 deletions

diff --git a/lib/geom/nop/geom_nop.c b/lib/geom/nop/geom_nop.c
index 65dc07cf1a3c..12321d2179f2 100644
--- a/lib/geom/nop/geom_nop.c
+++ b/lib/geom/nop/geom_nop.c
@@ -43,29 +43,36 @@ uint32_t version = G_NOP_VERSION;
 struct g_command class_commands[] = {
 	{ "create", G_FLAG_VERBOSE | G_FLAG_LOADKLD, NULL,
 	    {
+		{ 'd', "delaymsec", "-1", G_TYPE_NUMBER },
 		{ 'e', "error", "-1", G_TYPE_NUMBER },
 		{ 'o', "offset", "0", G_TYPE_NUMBER },
 		{ 'p', "stripesize", "0", G_TYPE_NUMBER },
 		{ 'P', "stripeoffset", "0", G_TYPE_NUMBER },
+		{ 'q', "rdelayprob", "-1", G_TYPE_NUMBER },
 		{ 'r', "rfailprob", "-1", G_TYPE_NUMBER },
 		{ 's', "size", "0", G_TYPE_NUMBER },
 		{ 'S', "secsize", "0", G_TYPE_NUMBER },
 		{ 'w', "wfailprob", "-1", G_TYPE_NUMBER },
+		{ 'x', "wdelayprob", "1", G_TYPE_NUMBER },
 		{ 'z', "physpath", G_NOP_PHYSPATH_PASSTHROUGH, G_TYPE_STRING },
 		G_OPT_SENTINEL
 	    },
-	    "[-v] [-e error] [-o offset] [-p stripesize] [-P stripeoffset] "
-	    "[-r rfailprob] [-s size] [-S secsize] [-w wfailprob] "
-	    "[-z physpath] dev ..."
+	    "[-v] [-d delaymsec] [-e error] [-o offset] [-p stripesize] "
+	    "[-P stripeoffset] [-q rdelayprob] [-r rfailprob] [-s size] "
+	    "[-S secsize] [-w wfailprob] [-x wdelayprob] [-z physpath] dev ..."
 	},
 	{ "configure", G_FLAG_VERBOSE, NULL,
 	    {
+		{ 'd', "delaymsec", "-1", G_TYPE_NUMBER },
 		{ 'e', "error", "-1", G_TYPE_NUMBER },
+		{ 'q', "rdelayprob", "-1", G_TYPE_NUMBER },
 		{ 'r', "rfailprob", "-1", G_TYPE_NUMBER },
 		{ 'w', "wfailprob", "-1", G_TYPE_NUMBER },
+		{ 'x', "wdelayprob", "1", G_TYPE_NUMBER },
 		G_OPT_SENTINEL
 	    },
-	    "[-v] [-e error] [-r rfailprob] [-w wfailprob] prov ..."
+	    "[-v] [-d delaymsec] [-e error] [-q rdelayprob] [-r rfailprob] "
+	    "[-w wfailprob] [-x wdelayprob] prov ..."
 	},
 	{ "destroy", G_FLAG_VERBOSE, NULL,
 	    {
diff --git a/lib/geom/nop/gnop.8 b/lib/geom/nop/gnop.8
index f9b3dc2c440e..ef6c44bc5297 100644
--- a/lib/geom/nop/gnop.8
+++ b/lib/geom/nop/gnop.8
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd January 17, 2018
+.Dd July 31, 2019
 .Dt GNOP 8
 .Os
 .Sh NAME
@@ -34,22 +34,28 @@
 .Nm
 .Cm create
 .Op Fl v
+.Op Fl d Ar delaymsec
 .Op Fl e Ar error
 .Op Fl o Ar offset
 .Op Fl p Ar stripesize
 .Op Fl P Ar stripeoffset
+.Op Fl q Ar rdelayprob
 .Op Fl r Ar rfailprob
 .Op Fl s Ar size
 .Op Fl S Ar secsize
 .Op Fl w Ar wfailprob
+.Op Fl x Ar wdelayprob
 .Op Fl z Ar physpath
 .Ar dev ...
 .Nm
 .Cm configure
 .Op Fl v
+.Op Fl d Ar delaymsec
 .Op Fl e Ar error
+.Op Fl q Ar rdelayprob
 .Op Fl r Ar rfailprob
 .Op Fl w Ar wfailprob
+.Op Fl x Ar wdelayprob
 .Ar prov ...
 .Nm
 .Cm destroy
@@ -113,6 +119,9 @@ See
 .Pp
 Additional options:
 .Bl -tag -width ".Fl r Ar rfailprob"
+.It Fl d Ar delaymsec
+Specifies the delay of the requests in milliseconds.
+Note that requests will be delayed before they are sent to the backing device.
 .It Fl e Ar error
 Specifies the error number to return on failure.
 .It Fl f
@@ -123,6 +132,8 @@ Where to begin on the original provider.
 Value of the stripesize property of the transparent provider.
 .It Fl P Ar stripeoffset
 Value of the stripeoffset property of the transparent provider.
+.It Fl q Ar rdelayprob
+Specifies read delay probability in percent.
 .It Fl r Ar rfailprob
 Specifies read failure probability in percent.
 .It Fl s Ar size
@@ -133,6 +144,8 @@ Sector size of the transparent provider.
 Specifies write failure probability in percent.
 .It Fl v
 Be more verbose.
+.It Fl x Ar wdelayprob
+Specifies write delay probability in percent.
 .It Fl z Ar physpath
 Physical path of the transparent provider.
 .El