diff -Nru mdadm-4.1/debian/changelog mdadm-4.1/debian/changelog
--- mdadm-4.1/debian/changelog	2019-12-04 19:44:30.000000000 +0000
+++ mdadm-4.1/debian/changelog	2019-12-10 20:35:16.000000000 +0000
@@ -1,3 +1,9 @@
+mdadm (4.1-1ubuntu1.2) disco; urgency=medium
+
+  * Introduce "broken" state for RAID0/Linear in mdadm (LP: #1847924)
+
+ -- Guilherme G. Piccoli <gpiccoli@canonical.com>  Tue, 10 Dec 2019 20:35:16 +0000
+
 mdadm (4.1-1ubuntu1.1) disco; urgency=medium
 
   * Add support for RAID0 layouts. Released kernels are being updated
diff -Nru mdadm-4.1/debian/patches/lp1847924-Introduce-new-array-state-broken-for-raid0.patch mdadm-4.1/debian/patches/lp1847924-Introduce-new-array-state-broken-for-raid0.patch
--- mdadm-4.1/debian/patches/lp1847924-Introduce-new-array-state-broken-for-raid0.patch	1970-01-01 00:00:00.000000000 +0000
+++ mdadm-4.1/debian/patches/lp1847924-Introduce-new-array-state-broken-for-raid0.patch	2019-12-10 20:35:05.000000000 +0000
@@ -0,0 +1,159 @@
+Subject: Introduce new array state 'broken' for raid0/linear
+
+Currently if a md raid0/linear array gets one or more members removed while
+being mounted, kernel keeps showing state 'clean' in the 'array_state'
+sysfs attribute. Despite udev signaling the member device is gone, 'mdadm'
+cannot issue the STOP_ARRAY ioctl successfully, given the array is mounted.
+
+Nothing else hints that something is wrong (except that the removed devices
+don't show properly in the output of mdadm 'detail' command). There is no
+other property to be checked, and if user is not performing reads/writes
+to the array, even kernel log is quiet and doesn't give a clue about the
+missing member.
+
+This patch is the mdadm counterpart of kernel new array state 'broken'.
+The 'broken' state mimics the state 'clean' in every aspect, being useful
+only to distinguish if an array has some member missing. All necessary
+paths in mdadm were changed to deal with 'broken' state, and in case the
+tool runs in a kernel that is not updated, it'll work normally, i.e., it
+doesn't require the 'broken' state in order to work.
+
+NOTICE that the original version of this patch also changes the way the
+array state is showed in the 'detail' command (for raid0/linear only),
+taking the sysfs attribute 'array_state' into account.
+But ** for SRU purposes ** this specific version keeps the old behavior
+in Bionic / Disco / Eoan, adding just the 'broken' state, otherwise
+always showing 'clean'.
+
+Author: Guilherme G. Piccoli <gpiccoli@canonical.com>
+Origin: upstream,
+git.kernel.org/pub/scm/utils/mdadm/mdadm.git/commit/?id=43ebc9105e9d
+Bug-Ubuntu: https://bugs.launchpad.net/bugs/1847924
+Last-Update: 2019-12-10
+
+diff --git a/Detail.c b/Detail.c
+index ce69796..2a69611 100644
+--- a/Detail.c
++++ b/Detail.c
+@@ -81,6 +81,7 @@ int Detail(char *dev, struct context *c)
+ 	int external;
+ 	int inactive;
+ 	int is_container = 0;
++	char *arrayst;
+ 
+ 	if (fd < 0) {
+ 		pr_err("cannot open %s: %s\n",
+@@ -485,9 +486,25 @@ int Detail(char *dev, struct context *c)
+ 			else
+ 				st = ", degraded";
+ 
++			if (array.state & (1 << MD_SB_CLEAN)) {
++				if ((array.level == 0) ||
++				    (array.level == LEVEL_LINEAR)) {
++					arrayst = map_num(sysfs_array_states,
++							  sra->array_state);
++
++					/* This is to keep output compatibility
++					 * in the SRU for B/D/E - we only change
++					 * the state output in case it's "broken"
++					 */
++					if (strcmp(arrayst, "broken"))
++						arrayst = "clean";
++				} else
++					arrayst = "clean";
++			} else
++				arrayst = "active";
++
+ 			printf("             State : %s%s%s%s%s%s \n",
+-			       (array.state & (1 << MD_SB_CLEAN)) ?
+-			       "clean" : "active", st,
++			       arrayst, st,
+ 			       (!e || (e->percent < 0 &&
+ 				       e->percent != RESYNC_PENDING &&
+ 				       e->percent != RESYNC_DELAYED)) ?
+diff --git a/Monitor.c b/Monitor.c
+index 036103f..b527165 100644
+--- a/Monitor.c
++++ b/Monitor.c
+@@ -1055,8 +1055,11 @@ int Wait(char *dev)
+ 	}
+ }
+ 
++/* The state "broken" is used only for RAID0/LINEAR - it's the same as
++ * "clean", but used in case the array has one or more members missing.
++ */
+ static char *clean_states[] = {
+-	"clear", "inactive", "readonly", "read-auto", "clean", NULL };
++	"clear", "inactive", "readonly", "read-auto", "clean", "broken", NULL };
+ 
+ int WaitClean(char *dev, int verbose)
+ {
+@@ -1116,7 +1119,8 @@ int WaitClean(char *dev, int verbose)
+ 			rv = read(state_fd, buf, sizeof(buf));
+ 			if (rv < 0)
+ 				break;
+-			if (sysfs_match_word(buf, clean_states) <= 4)
++			if (sysfs_match_word(buf, clean_states) <
++			    (int)ARRAY_SIZE(clean_states) - 1)
+ 				break;
+ 			rv = sysfs_wait(state_fd, &delay);
+ 			if (rv < 0 && errno != EINTR)
+diff --git a/maps.c b/maps.c
+index f143552..a4fd279 100644
+--- a/maps.c
++++ b/maps.c
+@@ -162,6 +162,7 @@ mapping_t sysfs_array_states[] = {
+ 	{ "read-auto", ARRAY_READ_AUTO },
+ 	{ "clean", ARRAY_CLEAN },
+ 	{ "write-pending", ARRAY_WRITE_PENDING },
++	{ "broken", ARRAY_BROKEN },
+ 	{ NULL, ARRAY_UNKNOWN_STATE }
+ };
+ 
+diff --git a/mdadm.h b/mdadm.h
+index 8da9170..b23308c 100644
+--- a/mdadm.h
++++ b/mdadm.h
+@@ -345,6 +345,7 @@ struct mdinfo {
+ 		ARRAY_ACTIVE,
+ 		ARRAY_WRITE_PENDING,
+ 		ARRAY_ACTIVE_IDLE,
++		ARRAY_BROKEN,
+ 		ARRAY_UNKNOWN_STATE,
+ 	} array_state;
+ 	struct md_bb bb;
+diff --git a/mdmon.h b/mdmon.h
+index 818367c..b3d72ac 100644
+--- a/mdmon.h
++++ b/mdmon.h
+@@ -21,7 +21,7 @@
+ extern const char Name[];
+ 
+ enum array_state { clear, inactive, suspended, readonly, read_auto,
+-		   clean, active, write_pending, active_idle, bad_word};
++		   clean, active, write_pending, active_idle, broken, bad_word};
+ 
+ enum sync_action { idle, reshape, resync, recover, check, repair, bad_action };
+ 
+diff --git a/monitor.c b/monitor.c
+index 81537ed..e0d3be6 100644
+--- a/monitor.c
++++ b/monitor.c
+@@ -26,7 +26,7 @@
+ 
+ static char *array_states[] = {
+ 	"clear", "inactive", "suspended", "readonly", "read-auto",
+-	"clean", "active", "write-pending", "active-idle", NULL };
++	"clean", "active", "write-pending", "active-idle", "broken", NULL };
+ static char *sync_actions[] = {
+ 	"idle", "reshape", "resync", "recover", "check", "repair", NULL
+ };
+@@ -476,7 +476,7 @@ static int read_and_act(struct active_array *a, fd_set *fds)
+ 		a->next_state = clean;
+ 		ret |= ARRAY_DIRTY;
+ 	}
+-	if (a->curr_state == clean) {
++	if ((a->curr_state == clean) || (a->curr_state == broken)) {
+ 		a->container->ss->set_array_state(a, 1);
+ 	}
+ 	if (a->curr_state == active ||
diff -Nru mdadm-4.1/debian/patches/series mdadm-4.1/debian/patches/series
--- mdadm-4.1/debian/patches/series	2019-12-04 19:41:34.000000000 +0000
+++ mdadm-4.1/debian/patches/series	2019-12-10 20:35:05.000000000 +0000
@@ -16,3 +16,4 @@
 mdmonitor-service-simplify.diff
 0001-Create-add-support-for-RAID0-layouts.patch
 0002-Assemble-add-support-for-RAID0-layouts.patch
+lp1847924-Introduce-new-array-state-broken-for-raid0.patch