tools lib api fs: Add FSTYPE__mount() method

Adding FSTYPE__mount (where FSTYPE is, as of now, one of sysfs, procfs,
debugfs, tracefs) method that tries to mount the filesystem in case no
mount of FSTYPE is found.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Raphael Beamonte <raphael.beamonte@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1441180605-24737-12-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c
index ef16d2a83a27626a18d6e07f78ac9074e6f380e9..bc93baf33fffca625f0585e966595ae6ceac9b9d 100644 (file)
--- a/tools/lib/api/fs/fs.c
+++ b/tools/lib/api/fs/fs.c
@@ -9,6 +9,7 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <sys/mount.h>
 
 #include "debugfs.h"
 #include "fs.h"
@@ -215,16 +216,49 @@ static const char *fs__mountpoint(int idx)
        return fs__get_mountpoint(fs);
 }
 
-#define FS__MOUNTPOINT(name, idx)      \
+static const char *mount_overload(struct fs *fs)
+{
+       size_t name_len = strlen(fs->name);
+       /* "PERF_" + name + "_ENVIRONMENT" + '\0' */
+       char upper_name[5 + name_len + 12 + 1];
+
+       snprintf(upper_name, name_len, "PERF_%s_ENVIRONMENT", fs->name);
+       mem_toupper(upper_name, name_len);
+
+       return getenv(upper_name) ?: *fs->mounts;
+}
+
+static const char *fs__mount(int idx)
+{
+       struct fs *fs = &fs__entries[idx];
+       const char *mountpoint;
+
+       if (fs__mountpoint(idx))
+               return (const char *)fs->path;
+
+       mountpoint = mount_overload(fs);
+
+       if (mount(NULL, mountpoint, fs->name, 0, NULL) < 0)
+               return NULL;
+
+       return fs__check_mounts(fs) ? fs->path : NULL;
+}
+
+#define FS(name, idx)                  \
 const char *name##__mountpoint(void)   \
 {                                      \
        return fs__mountpoint(idx);     \
+}                                      \
+                                       \
+const char *name##__mount(void)                \
+{                                      \
+       return fs__mount(idx);          \
 }
 
-FS__MOUNTPOINT(sysfs,   FS__SYSFS);
-FS__MOUNTPOINT(procfs,  FS__PROCFS);
-FS__MOUNTPOINT(debugfs, FS__DEBUGFS);
-FS__MOUNTPOINT(tracefs, FS__TRACEFS);
+FS(sysfs,   FS__SYSFS);
+FS(procfs,  FS__PROCFS);
+FS(debugfs, FS__DEBUGFS);
+FS(tracefs, FS__TRACEFS);
 
 int filename__read_int(const char *filename, int *value)
 {

diff --git a/tools/lib/api/fs/fs.h b/tools/lib/api/fs/fs.h
index 9013227ae0d12b6e537d2b2805f71d952afa86f6..a9627ea5e6ae73753bdc41f9ec84bb331e99c2d9 100644 (file)
--- a/tools/lib/api/fs/fs.h
+++ b/tools/lib/api/fs/fs.h
@@ -9,10 +9,17 @@
 #define PATH_MAX 4096
 #endif
 
-const char *sysfs__mountpoint(void);
-const char *procfs__mountpoint(void);
-const char *debugfs__mountpoint(void);
-const char *tracefs__mountpoint(void);
+#define FS(name)                               \
+       const char *name##__mountpoint(void);   \
+       const char *name##__mount(void);
+
+FS(sysfs)
+FS(procfs)
+FS(debugfs)
+FS(tracefs)
+
+#undef FS
+
 
 int filename__read_int(const char *filename, int *value);
 int sysctl__read_int(const char *sysctl, int *value);