pvscan: use alternate device names from DEVLINKS to check filterdev-dct-pvscan-devlinks

The filter may contains a symlink for the device, and that symlink
may not yet be created when our udev rule runs pvscan --cache using
the kernel dev name.  The kernel dev name does not match the symlink
name in the filter, so pvscan will ignore the device.  udev sets
the DEVLINKS env variable to a list of link names for the device
that will be created, so check the filter with that set of names.

3 files changed, 26 insertions, 0 deletions

diff --git a/lib/device/dev-cache.c b/lib/device/dev-cache.c
index 85f9b499a..a8b132d41 100644
--- a/lib/device/dev-cache.c
+++ b/lib/device/dev-cache.c
@@ -52,6 +52,7 @@ static struct {
 	struct dm_regex *preferred_names_matcher;
 	const char *dev_dir;
 
+	int preferred_names_disabled;
 	int has_scanned;
 	long st_dev;
 	struct dm_list dirs;
@@ -166,11 +167,19 @@ void dev_set_preferred_name(struct dm_str_list *sl, struct device *dev)
 	if (_cache.preferred_names_matcher)
 		return;
 
+	if (_cache.preferred_names_disabled)
+		return;
+
 	log_debug_devs("%s: New preferred name", sl->str);
 	dm_list_del(&sl->list);
 	dm_list_add_h(&dev->aliases, &sl->list);
 }
 
+void dev_cache_disable_preferred_names(void)
+{
+	_cache.preferred_names_disabled = 1;
+}
+
 /*
  * Check whether path0 or path1 contains the subpath. The path that
  * *does not* contain the subpath wins (return 0 or 1). If both paths
diff --git a/lib/device/dev-cache.h b/lib/device/dev-cache.h
index 7ffe01152..cee893e6a 100644
--- a/lib/device/dev-cache.h
+++ b/lib/device/dev-cache.h
@@ -61,6 +61,8 @@ struct device *dev_hash_get(const char *name);
 
 void dev_set_preferred_name(struct dm_str_list *sl, struct device *dev);
 
+void dev_cache_disable_preferred_names(void);
+
 /*
  * Object for iterating through the cache.
  */
diff --git a/tools/pvscan.c b/tools/pvscan.c
index 773862227..670b3d381 100644
--- a/tools/pvscan.c
+++ b/tools/pvscan.c
@@ -44,6 +44,8 @@ struct pvscan_aa_params {
  */
 static struct volume_group *saved_vg;
 
+static int _found_filter_symlinks;
+
 static int _pvscan_display_pv(struct cmd_context *cmd,
 				  struct physical_volume *pv,
 				  struct pvscan_params *params)
@@ -930,6 +932,7 @@ static int _get_args_devs(struct cmd_context *cmd, struct dm_list *pvscan_args,
 	if (!cmd->enable_devices_file && !cmd->enable_devices_list &&
 	    (_filter_uses_symlinks(cmd, devices_filter_CFG) ||
 	     _filter_uses_symlinks(cmd, devices_global_filter_CFG))) {
+		_found_filter_symlinks = 1;
 		log_print_pvscan(cmd, "finding all devices for filter symlinks.");
 		dev_cache_scan(cmd);
 	}
@@ -1550,6 +1553,18 @@ static int _pvscan_cache_args(struct cmd_context *cmd, int argc, char **argv,
 
 	cmd->filter_nodata_only = 1;
 
+	if ((dm_list_size(&pvscan_devs) == 1) && _found_filter_symlinks) {
+		char *env_str;
+		struct dm_list *env_aliases;
+		devl = dm_list_item(dm_list_first(&pvscan_devs), struct device_list);
+		if ((env_str = getenv("DEVLINKS"))) {
+			env_aliases = str_to_str_list(cmd->mem, env_str, " ", 0);
+			dm_list_splice(&devl->dev->aliases, env_aliases);
+		}
+		/* A symlink from env may not actually exist so don't try to use it. */
+		dev_cache_disable_preferred_names();
+	}
+
 	dm_list_iterate_items_safe(devl, devl2, &pvscan_devs) {
 		if (!cmd->filter->passes_filter(cmd, cmd->filter, devl->dev, NULL)) {
 			log_print_pvscan(cmd, "%s excluded: %s.",