[Ocfs2-devel] [PATCH] debugfs.ocfs2: Allow dumping dlm locks from a file

[Mark Fasheh]

This way we can review locking state even if all a customer provides us is
the contents of /sys/kernel/debug/o2dlm/locking_state.

Signed-off-by: Mark Fasheh <mfasheh at suse.com>
---
 debugfs.ocfs2/commands.c               |   36 ++++++++++++++++++++++-------
 debugfs.ocfs2/dump_dlm_locks.c         |   38 ++++++++++++++++++++-----------
 debugfs.ocfs2/include/dump_dlm_locks.h |    2 +-
 3 files changed, 52 insertions(+), 24 deletions(-)

diff --git a/debugfs.ocfs2/commands.c b/debugfs.ocfs2/commands.c
index 0e46151..06b6c98 100644
--- a/debugfs.ocfs2/commands.c
+++ b/debugfs.ocfs2/commands.c
@@ -831,7 +831,7 @@ static void do_help (char **args)
 	printf ("controld dump\t\t\tObtain information from ocfs2_controld\n");
 	printf ("curdev\t\t\t\t\tShow current device\n");
 	printf ("decode <lockname#> ...\t\t\tDecode block#(s) from the lockname(s)\n");
-	printf ("dlm_locks [-l] lockname\t\t\tShow live dlm locking state\n");
+	printf ("dlm_locks [-f <file>] [-l] lockname\t\t\tShow live dlm locking state\n");
 	printf ("dump [-p] <filespec> <outfile>\t\tDumps file to outfile on a mounted fs\n");
 	printf ("encode <filespec>\t\t\tShow lock name\n");
 	printf ("extent <block#>\t\t\t\tShow extent block\n");
@@ -1485,26 +1485,44 @@ static void do_dlm_locks(char **args)
 	int dump_lvbs = 0;
 	int i;
 	struct list_head locklist;
-
-	if (check_device_open())
-		return;
+	char *path = NULL, *uuid_str = NULL;
+	int c, argc;
 
 	init_stringlist(&locklist);
 
-	i = 1;
-	if (args[i] && strlen(args[i])) {
-		if (!strcmp("-l", args[i])) {
+	for (argc = 0; (args[argc]); ++argc);
+	optind = 0;
+
+	while ((c = getopt(argc, args, "lf:")) != -1) {
+		switch (c) {
+		case 'l':
 			dump_lvbs = 1;
-			i++;
+			break;
+		case 'f':
+			path = optarg;
+			break;
+		default:
+			break;
 		}
+	}
+	if ((path == NULL)) {
+		/* Only error for a missing device if we're asked to
+		 * read from a live file system. */
+		if (check_device_open())
+			return;
+
+		uuid_str = gbls.fs->uuid_str;
+	}
 
+	i = optind;
+	if (args[i] && strlen(args[i])) {
 		for ( ; args[i] && strlen(args[i]); ++i)
 			if (add_to_stringlist(args[i], &locklist))
 				break;
 	}
 
 	out = open_pager(gbls.interactive);
-	dump_dlm_locks(gbls.fs->uuid_str, out, dump_lvbs, &locklist);
+	dump_dlm_locks(uuid_str, out, path, dump_lvbs, &locklist);
 	close_pager(out);
 
 	free_stringlist(&locklist);
diff --git a/debugfs.ocfs2/dump_dlm_locks.c b/debugfs.ocfs2/dump_dlm_locks.c
index b946821..6344ff1 100644
--- a/debugfs.ocfs2/dump_dlm_locks.c
+++ b/debugfs.ocfs2/dump_dlm_locks.c
@@ -411,7 +411,7 @@ static int get_next_dlm_lockname(FILE *file, char *name, int len)
 	return 0;
 }
 
-void dump_dlm_locks(char *uuid, FILE *out, int dump_lvbs,
+void dump_dlm_locks(char *uuid, FILE *out, char *path, int dump_lvbs,
 		    struct list_head *locklist)
 {
 	errcode_t ret;
@@ -421,20 +421,30 @@ void dump_dlm_locks(char *uuid, FILE *out, int dump_lvbs,
 	struct lockres res;
 	int show_all_locks = 0;
 
-	ret = get_debugfs_path(debugfs_path, sizeof(debugfs_path));
-	if (ret) {
-		fprintf(stderr, "Could not locate debugfs file system. "
-			"Perhaps it is not mounted?\n");
-		return;
-	}
+	if (path == NULL) {
+		ret = get_debugfs_path(debugfs_path, sizeof(debugfs_path));
+		if (ret) {
+			fprintf(stderr, "Could not locate debugfs file system. "
+				"Perhaps it is not mounted?\n");
+			return;
+		}
 
-	ret = open_debugfs_file(debugfs_path, "o2dlm", uuid, "locking_state",
-				&file);
-	if (ret) {
-		fprintf(stderr, "Could not open debug state for \"%s\".\n"
-			"Perhaps that OCFS2 file system is not mounted?\n",
-			uuid);
-		return;
+		ret = open_debugfs_file(debugfs_path, "o2dlm", uuid,
+					"locking_state", &file);
+		if (ret) {
+			fprintf(stderr,
+				"Could not open debug state for \"%s\".\n"
+				"Perhaps that OCFS2 file system is not mounted?\n",
+				uuid);
+			return;
+		}
+	} else {
+		file = fopen(path, "r");
+		if (!file) {
+			fprintf(stderr, "Could not open file at \"%s\"\n",
+				path);
+			return;
+		}
 	}
 
 	show_all_locks = list_empty(locklist);
diff --git a/debugfs.ocfs2/include/dump_dlm_locks.h b/debugfs.ocfs2/include/dump_dlm_locks.h
index 2cbb72a..7bc35ba 100644
--- a/debugfs.ocfs2/include/dump_dlm_locks.h
+++ b/debugfs.ocfs2/include/dump_dlm_locks.h
@@ -74,7 +74,7 @@ struct lock {
 	struct list_head list;
 };
 
-void dump_dlm_locks(char *uuid, FILE *out, int dump_lvbs,
+void dump_dlm_locks(char *uuid, FILE *out, char *path, int dump_lvbs,
 		    struct list_head *locklist);
 
 #endif		/* _DUMP_DLM_LOCKS_H_ */
-- 
1.6.0.2