From 459d931a9bfe4c9adcbbf2e76fdf35fda5b13c61 Mon Sep 17 00:00:00 2001

From: David Teigland <teigland@redhat.com>

Date: Fri, 12 Nov 2021 16:42:51 -0600

Subject: [PATCH 09/23] device_id: match different dm device names

If a devices file entry for a dm device is using the devname

for the device id, then recognize different dm names as matching.

---

 lib/device/device_id.c | 81 +++++++++++++++++++++++++++++++++++-------

 1 file changed, 69 insertions(+), 12 deletions(-)

diff --git a/lib/device/device_id.c b/lib/device/device_id.c

index eb06109ff..dea739fc4 100644

--- a/lib/device/device_id.c

+++ b/lib/device/device_id.c

@@ -1360,6 +1360,10 @@ void device_id_update_vg_uuid(struct cmd_context *cmd, struct volume_group *vg,

 static int _idtype_compatible_with_major_number(struct cmd_context *cmd, int idtype, int major)

 {

+	/* devname can be used with any kind of device */

+	if (idtype == DEV_ID_TYPE_DEVNAME)

+		return 1;

+

 	if (idtype == DEV_ID_TYPE_MPATH_UUID ||

 	    idtype == DEV_ID_TYPE_CRYPT_UUID ||

 	    idtype == DEV_ID_TYPE_LVMLV_UUID)

@@ -1388,6 +1392,43 @@ static int _idtype_compatible_with_major_number(struct cmd_context *cmd, int idt

 	return 1;

 }

+static int _match_dm_devnames(struct cmd_context *cmd, struct device *dev,

+			      struct dev_id *id, struct dev_use *du)

+{

+	struct stat buf;

+

+	if (MAJOR(dev->dev) != cmd->dev_types->device_mapper_major)

+		return 0;

+

+	if (id->idname && du->idname && !strcmp(id->idname, du->idname))

+		return 1;

+

+	if (du->idname && !strcmp(du->idname, dev_name(dev))) {

+		log_debug("Match device_id %s %s to %s: ignoring idname %s",

+			  idtype_to_str(du->idtype), du->idname, dev_name(dev), id->idname ?: ".");

+		return 1;

+	}

+

+	if (!du->idname)

+		return 0;

+

+	/* detect that a du entry is for a dm device */

+

+	if (!strncmp(du->idname, "/dev/dm-", 8) || !strncmp(du->idname, "/dev/mapper/", 12)) {

+		if (stat(du->idname, &buf))

+			return 0;

+

+		if ((MAJOR(buf.st_rdev) == cmd->dev_types->device_mapper_major) &&

+		    (MINOR(buf.st_rdev) == MINOR(dev->dev))) {

+			log_debug("Match device_id %s %s to %s: using other dm name, ignoring %s",

+				  idtype_to_str(du->idtype), du->idname, dev_name(dev), id->idname ?: ".");

+			return 1;

+		}

+	}

+

+	return 0;

+}

+

 /*

  * check for dev->ids entry with du->idtype, if found compare it,

  * if not, system_read of this type and add entry to dev->ids, compare it.

@@ -1408,35 +1449,52 @@ static int _match_du_to_dev(struct cmd_context *cmd, struct dev_use *du, struct

 	 * so we can skip trying to match certain du entries based simply on

 	 * the major number of dev.

 	 */

-	if (!_idtype_compatible_with_major_number(cmd, du->idtype, (int)MAJOR(dev->dev)))

+	if (!_idtype_compatible_with_major_number(cmd, du->idtype, (int)MAJOR(dev->dev))) {

+		/*

+		log_debug("Mismatch device_id %s %s to %s: wrong major",

+			  idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev));

+		*/

 		return 0;

+	}

 	if (!dev_get_partition_number(dev, &part)) {

-		log_debug("compare %s failed to get dev partition", dev_name(dev));

+		/*

+		log_debug("Mismatch device_id %s %s to %s: no partition",

+			  idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev));

+		*/

 		return 0;

 	}

 	if (part != du->part) {

 		/*

-		log_debug("compare mis %s %s part %d to %s part %d",

-			  idtype_to_str(du->idtype), du->idname ?: ".", du->part, dev_name(dev), part);

+		log_debug("Mismatch device_id %s %s to %s: wrong partition %d vs %d",

+			  idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev), du->part, part);

 		*/

 		return 0;

 	}

 	dm_list_iterate_items(id, &dev->ids) {

 		if (id->idtype == du->idtype) {

-			if (id->idname && !strcmp(id->idname, du->idname)) {

+			if ((id->idtype == DEV_ID_TYPE_DEVNAME) && _match_dm_devnames(cmd, dev, id, du)) {

+				/* dm devs can have differing names that we know still match */

+				du->dev = dev;

+				dev->id = id;

+				dev->flags |= DEV_MATCHED_USE_ID;

+				log_debug("Match device_id %s %s to %s: dm names",

+					  idtype_to_str(du->idtype), du->idname, dev_name(dev));

+				return 1;

+

+			} else if (id->idname && !strcmp(id->idname, du->idname)) {

 				du->dev = dev;

 				dev->id = id;

 				dev->flags |= DEV_MATCHED_USE_ID;

 				log_debug("Match device_id %s %s to %s",

 					  idtype_to_str(du->idtype), du->idname, dev_name(dev));

 				return 1;

+

 			} else {

 				/*

-				log_debug("compare mis %s %s to %s %s",

-			  		  idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev),

-					  ((id->idtype != DEV_ID_TYPE_DEVNAME) && id->idname) ? id->idname : "");

+				log_debug("Mismatch device_id %s %s to %s: idname %s",

+			  		  idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev), id->idname ?: ":");

 				*/

 				return 0;

 			}

@@ -1456,7 +1514,7 @@ static int _match_du_to_dev(struct cmd_context *cmd, struct dev_use *du, struct

 		id->dev = dev;

 		dm_list_add(&dev->ids, &id->list);

 		/*

-		log_debug("compare mis %s %s to %s no idtype",

+		log_debug("Mismatch device_id %s %s to %s: no idtype",

 			  idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev));

 		*/

 		return 0;

@@ -1481,9 +1539,8 @@ static int _match_du_to_dev(struct cmd_context *cmd, struct dev_use *du, struct

 	}

 	/*

-	log_debug("compare mis %s %s to %s %s",

-		  idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev),

-		  ((id->idtype != DEV_ID_TYPE_DEVNAME) && id->idname) ? id->idname : "");

+	log_debug("Mismatch device_id %s %s to %s: idname %s",

+		  idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev), idname);

 	*/

 	return 0;

 }

-- 

2.31.1