[PATCH v2 1/3] perf tools: mount debugfs automatically

From: Xiao Guangrong
Date: Mon Dec 28 2009 - 03:49:12 EST


Mount debugfs filesystem under '/sys/kernel/debug' if it's not mounted

Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxx>
---
tools/perf/perf.c | 2 +-
tools/perf/util/debugfs.c | 16 +++++++---------
tools/perf/util/debugfs.h | 2 +-
3 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 873e55f..fc89005 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -388,7 +388,7 @@ 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)
{
- const char *path = debugfs_find_mountpoint();
+ const char *path = debugfs_mount(NULL);

if (path)
strncpy(debugfs_mntpt, path, sizeof(debugfs_mntpt));
diff --git a/tools/perf/util/debugfs.c b/tools/perf/util/debugfs.c
index 06b73ee..1f805fd 100644
--- a/tools/perf/util/debugfs.c
+++ b/tools/perf/util/debugfs.c
@@ -106,16 +106,14 @@ int debugfs_valid_entry(const char *path)
return 0;
}

-/* mount the debugfs somewhere */
+/* mount the debugfs somewhere if it's not mounted */

-int debugfs_mount(const char *mountpoint)
+char *debugfs_mount(const char *mountpoint)
{
- char mountcmd[128];
-
/* see if it's already mounted */
if (debugfs_find_mountpoint()) {
debugfs_premounted = 1;
- return 0;
+ return debugfs_mountpoint;
}

/* if not mounted and no argument */
@@ -127,13 +125,13 @@ int debugfs_mount(const char *mountpoint)
mountpoint = "/sys/kernel/debug";
}

+ if (mount(NULL, mountpoint, "debugfs", 0, NULL) < 0)
+ return NULL;
+
/* save the mountpoint */
strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint));

- /* mount it */
- snprintf(mountcmd, sizeof(mountcmd),
- "/bin/mount -t debugfs debugfs %s", mountpoint);
- return system(mountcmd);
+ return debugfs_mountpoint;
}

/* umount the debugfs */
diff --git a/tools/perf/util/debugfs.h b/tools/perf/util/debugfs.h
index 3cd14f9..83a0287 100644
--- a/tools/perf/util/debugfs.h
+++ b/tools/perf/util/debugfs.h
@@ -15,7 +15,7 @@
extern const char *debugfs_find_mountpoint(void);
extern int debugfs_valid_mountpoint(const char *debugfs);
extern int debugfs_valid_entry(const char *path);
-extern int debugfs_mount(const char *mountpoint);
+extern char *debugfs_mount(const char *mountpoint);
extern int debugfs_umount(void);
extern int debugfs_write(const char *entry, const char *value);
extern int debugfs_read(const char *entry, char *buffer, size_t size);
--
1.6.1.2


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