X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;ds=sidebyside;f=discover%2Fudev.c;h=f4754b1662b89517f159dbfd0dd265a696501d31;hb=515d2f03bae8d5617ee3bce5a46287203f7215c2;hp=537ef10263fa11193f03057d0335de48910abc0a;hpb=45e9e7a53540e87e2129bb11fd853501131fb795;p=petitboot

diff --git a/discover/udev.c b/discover/udev.c
index 537ef10..f4754b1 100644
--- a/discover/udev.c
+++ b/discover/udev.c
@@ -19,6 +19,7 @@
 #include <talloc/talloc.h>
 #include <waiter/waiter.h>
 #include <system/system.h>
+#include <process/process.h>
 
 #include "event.h"
 #include "udev.h"
@@ -70,9 +71,26 @@ static void udev_setup_device_params(struct udev_device *udev,
 				udev_list_entry_get_value(entry));
 }
 
+/*
+ * Search for LVM logical volumes. If any exist they should be recognised
+ * by udev as normal.
+ * Normally this is handled in an init script, but on some platforms
+ * disks are slow enough to come up that we need to check again.
+ */
+static void lvm_vg_search(struct device_handler *handler)
+{
+	if (process_run_simple(handler, pb_system_apps.vgscan, "-qq", NULL))
+		pb_log("%s: Failed to execute vgscan\n", __func__);
+
+	if (process_run_simple(handler, pb_system_apps.vgchange, "-ay", "-qq",
+				NULL))
+		pb_log("%s: Failed to execute vgchange\n", __func__);
+}
+
 static int udev_handle_block_add(struct pb_udev *udev, struct udev_device *dev,
 		const char *name)
 {
+	char *devlinks = NULL, *link, *saveptr = NULL;
 	struct discover_device *ddev;
 	unsigned int i = 0;
 	const char *typestr;
@@ -85,7 +103,6 @@ static int udev_handle_block_add(struct pb_udev *udev, struct udev_device *dev,
 	const char *ignored_types[] = {
 		"linux_raid_member",
 		"swap",
-		"LVM2_member",
 		NULL,
 	};
 	bool cdrom, usb;
@@ -124,10 +141,9 @@ static int udev_handle_block_add(struct pb_udev *udev, struct udev_device *dev,
 		}
 	}
 
-	/* If our environment's udev can recognise them explictly skip any
-	 * device mapper devices we encounter */
+	/* Ignore any device mapper devices that aren't logical volumes */
 	devname = udev_device_get_property_value(dev, "DM_NAME");
-	if (devname) {
+	if (devname && ! udev_device_get_property_value(dev, "DM_LV_NAME")) {
 		pb_debug("SKIP: dm-device %s\n", devname);
 		return 0;
 	}
@@ -146,6 +162,12 @@ static int udev_handle_block_add(struct pb_udev *udev, struct udev_device *dev,
 		i++;
 	}
 
+	/* Search for LVM logical volumes if we see an LVM member */
+	if (strncmp(type, "LVM2_member", strlen("LVM2_member")) == 0) {
+		lvm_vg_search(udev->handler);
+		return 0;
+	}
+
 	/* We may see multipath devices; they'll have the same uuid as an
 	 * existing device, so only parse the first. */
 	uuid = udev_device_get_property_value(dev, "ID_FS_UUID");
@@ -158,9 +180,31 @@ static int udev_handle_block_add(struct pb_udev *udev, struct udev_device *dev,
 		}
 	}
 
-	ddev = discover_device_create(udev->handler, name);
+	/* Use DM_NAME for logical volumes, or the device name otherwise */
+	ddev = discover_device_create(udev->handler, uuid, devname ?: name);
+
+	if (devname) {
+		/*
+		 * For logical volumes udev_device_get_devnode() returns a path
+		 * of the form "/dev/dm-xx". These nodes names are not
+		 * persistent and are opaque to the user. Instead use the more
+		 * recognisable "/dev/mapper/lv-name" node if it is available.
+		 */
+		devlinks = talloc_strdup(ddev,
+				udev_device_get_property_value(dev, "DEVLINKS"));
+		link = devlinks ? strtok_r(devlinks, " ", &saveptr) : NULL;
+		while (link) {
+			if (strncmp(link, "/dev/mapper/",
+					strlen("/dev/mapper/")) == 0) {
+				node = link;
+				break;
+			}
+			link = strtok_r(NULL, " ", &saveptr);
+		}
+	}
 
 	ddev->device_path = talloc_strdup(ddev, node);
+	talloc_free(devlinks);
 
 	if (uuid)
 		ddev->uuid = talloc_strdup(ddev, uuid);
@@ -176,10 +220,9 @@ static int udev_handle_block_add(struct pb_udev *udev, struct udev_device *dev,
 
 	udev_setup_device_params(dev, ddev);
 
-	/* Create a snapshot for all disks, unless it is an assembled RAID array */
+	/* Create a snapshot for all disk devices */
 	if ((ddev->device->type == DEVICE_TYPE_DISK ||
-	     ddev->device->type == DEVICE_TYPE_USB) &&
-	    !udev_device_get_property_value(dev, "MD_LEVEL"))
+	     ddev->device->type == DEVICE_TYPE_USB))
 		devmapper_init_snapshot(udev->handler, ddev);
 
 	device_handler_discover(udev->handler, ddev);
@@ -449,6 +492,7 @@ static int udev_process(void *arg)
 	return 0;
 }
 
+#ifdef UDEV_LOGGING
 static void udev_log_fn(struct udev __attribute__((unused)) *udev,
 	int __attribute__((unused)) priority, const char *file, int line,
 	const char *fn, const char *format, va_list args)
@@ -456,6 +500,7 @@ static void udev_log_fn(struct udev __attribute__((unused)) *udev,
       pb_log("libudev: %s %s:%d: ", fn, file, line);
       vfprintf(pb_log_get_stream(), format, args);
 }
+#endif
 
 struct pb_udev *udev_init(struct device_handler *handler,
 		struct waitset *waitset)
@@ -476,7 +521,9 @@ struct pb_udev *udev_init(struct device_handler *handler,
 
 	udev_set_userdata(udev->udev, udev);
 
+#ifdef UDEV_LOGGING
 	udev_set_log_fn(udev->udev, udev_log_fn);
+#endif
 
 	result = udev_setup_monitor(udev->udev, &udev->monitor);
 	if (result)