process_each: explicitly check for existing devicesdev-dct-toollib-scan

For an ordinary command, dev_cache_full_scan is always run
but is called as a side effect of something else.  Instead,
run it explicitly at the start of process_each, rather than
depending on some later side effect to do it.  Some cases,
like lvm shell, do not reliably trigger the dev_cache_full_scan
side effect and do not see that some devices exist.

1 files changed, 15 insertions, 3 deletions

diff --git a/tools/toollib.c b/tools/toollib.c
index 538373480..82fb48ffb 100644
--- a/tools/toollib.c
+++ b/tools/toollib.c
@@ -2137,14 +2137,19 @@ int process_each_vg(struct cmd_context *cmd,
 	}
 
 	/*
+	 * If this were not called here, it would be called as a side effect
+	 * of something else later on.  But sometimes, e.g. lvm shell, that
+	 * side effect cannot be relied on, so make it explicit here.
+	 */
+	dev_cache_full_scan(cmd->full_filter);
+
+	/*
 	 * First rescan for available devices, then force the next
 	 * label scan to be done.  get_vgnameids() will scan labels
 	 * (when not using lvmetad).
 	 */
-	if (cmd->command->flags & REQUIRES_FULL_LABEL_SCAN) {
-		dev_cache_full_scan(cmd->full_filter);
+	if (cmd->command->flags & REQUIRES_FULL_LABEL_SCAN)
 		lvmcache_force_next_label_scan();
-	}
 
 	/*
 	 * A list of all VGs on the system is needed when:
@@ -2754,6 +2759,13 @@ int process_each_lv(struct cmd_context *cmd, int argc, char **argv, uint32_t rea
 	}
 
 	/*
+	 * If this were not called here, it would be called as a side effect
+	 * of something else later on.  But sometimes, e.g. lvm shell, that
+	 * side effect cannot be relied on, so make it explicit here.
+	 */
+	dev_cache_full_scan(cmd->full_filter);
+
+	/*
 	 * A list of all VGs on the system is needed when:
 	 * . processing all VGs on the system
 	 * . A VG name is specified which may refer to one