perf tools: Modify perf routines to use new debugfs routines

modify perf.c get_debugfs_mntpnt() to use the util/debugfs.c
debugfs_find_mountpoint()

modify util/parse-events.c to use debugfs_valid_mountpoint().

Signed-off-by: Clark Williams <williams@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20091101155720.624cc87e@torg>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/perf.c

@@ -14,6 +14,7 @@
 #include "util/run-command.h"
 #include "util/parse-events.h"
 #include "util/string.h"
+#include "util/debugfs.h"
 
 const char perf_usage_string[] =
 	"perf [--version] [--help] COMMAND [ARGS]";
@@ -382,45 +383,12 @@ static int run_argv(int *argcp, const char ***argv)
 /* mini /proc/mounts parser: searching for "^blah /mount/point debugfs" */
 static void get_debugfs_mntpt(void)
 {
-	FILE *file;
-	char fs_type[100];
-	char debugfs[MAXPATHLEN];
+	const char *path = debugfs_find_mountpoint();
 
-	/*
-	 * try the standard location
-	 */
-	if (valid_debugfs_mount("/sys/kernel/debug/") == 0) {
-		strcpy(debugfs_mntpt, "/sys/kernel/debug/");
-		return;
-	}
-
-	/*
-	 * try the sane location
-	 */
-	if (valid_debugfs_mount("/debug/") == 0) {
-		strcpy(debugfs_mntpt, "/debug/");
-		return;
-	}
-
-	/*
-	 * give up and parse /proc/mounts
-	 */
-	file = fopen("/proc/mounts", "r");
-	if (file == NULL)
-		return;
-
-	while (fscanf(file, "%*s %"
-		      STR(MAXPATHLEN)
-		      "s %99s %*s %*d %*d\n",
-		      debugfs, fs_type) == 2) {
-		if (strcmp(fs_type, "debugfs") == 0)
-			break;
-	}
-	fclose(file);
-	if (strcmp(fs_type, "debugfs") == 0) {
-		strncpy(debugfs_mntpt, debugfs, MAXPATHLEN);
-		debugfs_mntpt[MAXPATHLEN - 1] = '\0';
-	}
+	if (path)
+		strncpy(debugfs_mntpt, path, sizeof(debugfs_mntpt));
+	else
+		debugfs_mntpt[0] = '\0';
 }
 
 int main(int argc, const char **argv)

tools/perf/util/parse-events.c

@@ -7,6 +7,7 @@
 #include "string.h"
 #include "cache.h"
 #include "header.h"
+#include "debugfs.h"
 
 int				nr_counters;
 
@@ -149,16 +150,6 @@ static int tp_event_has_id(struct dirent *sys_dir, struct dirent *evt_dir)
 
 #define MAX_EVENT_LENGTH 512
 
-int valid_debugfs_mount(const char *debugfs)
-{
-	struct statfs st_fs;
-
-	if (statfs(debugfs, &st_fs) < 0)
-		return -ENOENT;
-	else if (st_fs.f_type != (long) DEBUGFS_MAGIC)
-		return -ENOENT;
-	return 0;
-}
 
 struct tracepoint_path *tracepoint_id_to_path(u64 config)
 {
@@ -171,7 +162,7 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)
 	char evt_path[MAXPATHLEN];
 	char dir_path[MAXPATHLEN];
 
-	if (valid_debugfs_mount(debugfs_path))
+	if (debugfs_valid_mountpoint(debugfs_path))
 		return NULL;
 
 	sys_dir = opendir(debugfs_path);
@@ -510,7 +501,7 @@ static enum event_result parse_tracepoint_event(const char **strp,
 	char sys_name[MAX_EVENT_LENGTH];
 	unsigned int sys_length, evt_length;
 
-	if (valid_debugfs_mount(debugfs_path))
+	if (debugfs_valid_mountpoint(debugfs_path))
 		return 0;
 
 	evt_name = strchr(*strp, ':');
@@ -788,7 +779,7 @@ static void print_tracepoint_events(void)
 	char evt_path[MAXPATHLEN];
 	char dir_path[MAXPATHLEN];
 
-	if (valid_debugfs_mount(debugfs_path))
+	if (debugfs_valid_mountpoint(debugfs_path))
 		return;
 
 	sys_dir = opendir(debugfs_path);