[v5,05/22] libmultipath: trigger change uevent on new device creation

Commit Message

Martin Wilck April 13, 2018, 9:59 p.m. UTC

From: Benjamin Marzinski <[e-mail]>

When multipath first sees a path device with find_multipaths
enabled, it can't know if the device should be multipathed. This means
that it will not claim the device in udev.  If the device is eventually
multipathed, multipath should trigger a change uevent to update the udev
database to claim the device.

Signed-off-by: Benjamin Marzinski <[e-mail]>
Reviewed-by: Martin Wilck <[e-mail]>
Signed-off-by: Martin Wilck <[e-mail]>
---
 libmultipath/configure.c | 26 ++++++++++++++++++++++++--
 libmultipath/configure.h |  1 +
 libmultipath/wwids.c     |  2 +-
 multipath/main.c         |  2 +-
 multipathd/main.c        |  3 ++-
 5 files changed, 29 insertions(+), 5 deletions(-)

Comments

Hannes Reinecke April 16, 2018, 6:10 a.m. UTC | #1

On Fri, 13 Apr 2018 23:59:58 +0200
Martin Wilck <[e-mail]> wrote:

> From: Benjamin Marzinski <[e-mail]>
> 
> When multipath first sees a path device with find_multipaths
> enabled, it can't know if the device should be multipathed. This means
> that it will not claim the device in udev.  If the device is
> eventually multipathed, multipath should trigger a change uevent to
> update the udev database to claim the device.
> 
> Signed-off-by: Benjamin Marzinski <[e-mail]>
> Reviewed-by: Martin Wilck <[e-mail]>
> Signed-off-by: Martin Wilck <[e-mail]>
> ---
>  libmultipath/configure.c | 26 ++++++++++++++++++++++++--
>  libmultipath/configure.h |  1 +
>  libmultipath/wwids.c     |  2 +-
>  multipath/main.c         |  2 +-
>  multipathd/main.c        |  3 ++-
>  5 files changed, 29 insertions(+), 5 deletions(-)
> 

Reviewed-by: Hannes Reinecke <[e-mail]>

Cheers,

Hannes

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Patch

diff --git a/libmultipath/configure.c b/libmultipath/configure.c
index 1cd575e4..c56e972f 100644
--- a/libmultipath/configure.c
+++ b/libmultipath/configure.c
@@ -444,6 +444,28 @@  trigger_udev_change(const struct multipath *mpp)
 	udev_device_unref(udd);
 }
 
+void
+trigger_paths_udev_change(const struct multipath *mpp)
+{
+	struct pathgroup *pgp;
+	struct path *pp;
+	int i, j;
+
+	if (!mpp || !mpp->pg)
+		return;
+
+	vector_foreach_slot (mpp->pg, pgp, i) {
+		if (!pgp->paths)
+			continue;
+		vector_foreach_slot(pgp->paths, pp, j) {
+			if (!pp->udev)
+				continue;
+			sysfs_attr_set_value(pp->udev, "uevent", "change",
+					     strlen("change"));
+		}
+	}
+}
+
 static int
 is_mpp_known_to_udev(const struct multipath *mpp)
 {
@@ -842,8 +864,8 @@  int domap(struct multipath *mpp, char *params, int is_daemon)
 		 * succeeded
 		 */
 		mpp->force_udev_reload = 0;
-		if (mpp->action == ACT_CREATE)
-			remember_wwid(mpp->wwid);
+		if (mpp->action == ACT_CREATE && remember_wwid(mpp->wwid) == 1)
+			trigger_paths_udev_change(mpp);
 		if (!is_daemon) {
 			/* multipath client mode */
 			dm_switchgroup(mpp->alias, mpp->bestpg);
diff --git a/libmultipath/configure.h b/libmultipath/configure.h
index 27a7e6f6..545cbc20 100644
--- a/libmultipath/configure.h
+++ b/libmultipath/configure.h
@@ -37,3 +37,4 @@  int get_refwwid (enum mpath_cmds cmd, char * dev, enum devtypes dev_type,
 		 vector pathvec, char **wwid);
 int reload_map(struct vectors *vecs, struct multipath *mpp, int refresh, int is_daemon);
 struct udev_device *get_udev_device(const char *dev, enum devtypes dev_type);
+void trigger_paths_udev_change(const struct multipath *mpp);
diff --git a/libmultipath/wwids.c b/libmultipath/wwids.c
index d0256c2c..28063429 100644
--- a/libmultipath/wwids.c
+++ b/libmultipath/wwids.c
@@ -331,5 +331,5 @@  remember_wwid(char *wwid)
 		condlog(3, "wrote wwid %s to wwids file", wwid);
 	else
 		condlog(4, "wwid %s already in wwids file", wwid);
-	return 0;
+	return ret;
 }
diff --git a/multipath/main.c b/multipath/main.c
index ba837710..686b0372 100644
--- a/multipath/main.c
+++ b/multipath/main.c
@@ -425,7 +425,7 @@  configure (struct config *conf, enum mpath_cmds cmd,
 		}
 		if (cmd == CMD_ADD_WWID) {
 			r = remember_wwid(refwwid);
-			if (r == 0)
+			if (r >= 0)
 				printf("wwid '%s' added\n", refwwid);
 			else
 				printf("failed adding '%s' to wwids file\n",
diff --git a/multipathd/main.c b/multipathd/main.c
index 20b6fe02..10a0ee76 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -2323,7 +2323,8 @@  configure (struct vectors * vecs)
 
 	sync_maps_state(mpvec);
 	vector_foreach_slot(mpvec, mpp, i){
-		remember_wwid(mpp->wwid);
+		if (remember_wwid(mpp->wwid) == 1)
+			trigger_paths_udev_change(mpp);
 		update_map_pr(mpp);
 	}