perf tools: Factor sysfs code into generic fs object

Moving sysfs code into generic fs object and preparing it to carry
procfs support.

This should be merged with tools/lib/lk/debugfs.c at some point in the
future.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1383660887-1734-2-git-send-email-jolsa@redhat.com
[ Added fs__ namespace qualifier to some more functions ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

9 files changed, 119 insertions, 72 deletions

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 5b8639025aae..7fc8f179cae7 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -242,7 +242,7 @@ LIB_H += util/cache.h
 LIB_H += util/callchain.h
 LIB_H += util/build-id.h
 LIB_H += util/debug.h
-LIB_H += util/sysfs.h
+LIB_H += util/fs.h
 LIB_H += util/pmu.h
 LIB_H += util/event.h
 LIB_H += util/evsel.h
@@ -304,7 +304,7 @@ LIB_OBJS += $(OUTPUT)util/annotate.o
 LIB_OBJS += $(OUTPUT)util/build-id.o
 LIB_OBJS += $(OUTPUT)util/config.o
 LIB_OBJS += $(OUTPUT)util/ctype.o
-LIB_OBJS += $(OUTPUT)util/sysfs.o
+LIB_OBJS += $(OUTPUT)util/fs.o
 LIB_OBJS += $(OUTPUT)util/pmu.o
 LIB_OBJS += $(OUTPUT)util/environment.o
 LIB_OBJS += $(OUTPUT)util/event.o
diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index 48114d164e9f..f47bf459c3f5 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -2,7 +2,7 @@
 #include "parse-events.h"
 #include "evsel.h"
 #include "evlist.h"
-#include "sysfs.h"
+#include "fs.h"
 #include <lk/debugfs.h>
 #include "tests.h"
 #include <linux/hw_breakpoint.h>
diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index beb8cf9f9976..4af5a23b2423 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -1,5 +1,5 @@
 #include "util.h"
-#include "sysfs.h"
+#include "fs.h"
 #include "../perf.h"
 #include "cpumap.h"
 #include <assert.h>
diff --git a/tools/perf/util/fs.c b/tools/perf/util/fs.c
new file mode 100644
index 000000000000..a2413e842a02
--- /dev/null
+++ b/tools/perf/util/fs.c
@@ -0,0 +1,107 @@
+
+/* TODO merge/factor into tools/lib/lk/debugfs.c */
+
+#include "util.h"
+#include "util/fs.h"
+
+static const char * const sysfs__fs_known_mountpoints[] = {
+        "/sys",
+        0,
+};
+
+struct fs {
+        const char              *name;
+        const char * const      *mounts;
+        char                     path[PATH_MAX + 1];
+        bool                     found;
+        long                     magic;
+};
+
+enum {
+        FS__SYSFS = 0,
+};
+
+static struct fs fs__entries[] = {
+        [FS__SYSFS] = {
+                .name   = "sysfs",
+                .mounts = sysfs__fs_known_mountpoints,
+                .magic  = SYSFS_MAGIC,
+        },
+};
+
+static bool fs__read_mounts(struct fs *fs)
+{
+        bool found = false;
+        char type[100];
+        FILE *fp;
+
+        fp = fopen("/proc/mounts", "r");
+        if (fp == NULL)
+                return NULL;
+
+        while (!found &&
+               fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
+                      fs->path, type) == 2) {
+
+                if (strcmp(type, fs->name) == 0)
+                        found = true;
+        }
+
+        fclose(fp);
+        return fs->found = found;
+}
+
+static int fs__valid_mount(const char *fs, long magic)
+{
+        struct statfs st_fs;
+
+        if (statfs(fs, &st_fs) < 0)
+                return -ENOENT;
+        else if (st_fs.f_type != magic)
+                return -ENOENT;
+
+        return 0;
+}
+
+static bool fs__check_mounts(struct fs *fs)
+{
+        const char * const *ptr;
+
+        ptr = fs->mounts;
+        while (*ptr) {
+                if (fs__valid_mount(*ptr, fs->magic) == 0) {
+                        fs->found = true;
+                        strcpy(fs->path, *ptr);
+                        return true;
+                }
+                ptr++;
+        }
+
+        return false;
+}
+
+static const char *fs__get_mountpoint(struct fs *fs)
+{
+        if (fs__check_mounts(fs))
+                return fs->path;
+
+        return fs__read_mounts(fs) ? fs->path : NULL;
+}
+
+static const char *fs__find_mountpoint(int idx)
+{
+        struct fs *fs = &fs__entries[idx];
+
+        if (fs->found)
+                return (const char *)fs->path;
+
+        return fs__get_mountpoint(fs);
+}
+
+#define FIND_MOUNTPOINT(name, idx)              \
+const char *name##_find_mountpoint(void)        \
+{                                               \
+        return fs__find_mountpoint(idx);        \
+}
+
+FIND_MOUNTPOINT(sysfs, FS__SYSFS);
diff --git a/tools/perf/util/fs.h b/tools/perf/util/fs.h
new file mode 100644
index 000000000000..082edbd2159b
--- /dev/null
+++ b/tools/perf/util/fs.h
@@ -0,0 +1,6 @@
+#ifndef __PERF_FS
+#define __PERF_FS
+
+const char *sysfs_find_mountpoint(void);
+
+#endif /* __PERF_FS */
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 64362fe45b71..45b42dffcd70 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -4,7 +4,7 @@
 #include <unistd.h>
 #include <stdio.h>
 #include <dirent.h>
-#include "sysfs.h"
+#include "fs.h"
 #include "util.h"
 #include "pmu.h"
 #include "parse-events.h"
diff --git a/tools/perf/util/python-ext-sources b/tools/perf/util/python-ext-sources
index f75ae1b9900c..239036fb2b2c 100644
--- a/tools/perf/util/python-ext-sources
+++ b/tools/perf/util/python-ext-sources
@@ -17,5 +17,5 @@ util/xyarray.c
 util/cgroup.c
 util/rblist.c
 util/strlist.c
-util/sysfs.c
+util/fs.c
 ../../lib/rbtree.c
diff --git a/tools/perf/util/sysfs.c b/tools/perf/util/sysfs.c
deleted file mode 100644
index f71e9eafe15a..000000000000
--- a/tools/perf/util/sysfs.c
+++ /dev/null
@@ -1,60 +0,0 @@
-
-#include "util.h"
-#include "sysfs.h"
-
-static const char * const sysfs_known_mountpoints[] = {
-        "/sys",
-        0,
-};
-
-static int sysfs_found;
-char sysfs_mountpoint[PATH_MAX + 1];
-
-static int sysfs_valid_mountpoint(const char *sysfs)
-{
-        struct statfs st_fs;
-
-        if (statfs(sysfs, &st_fs) < 0)
-                return -ENOENT;
-        else if (st_fs.f_type != (long) SYSFS_MAGIC)
-                return -ENOENT;
-
-        return 0;
-}
-
-const char *sysfs_find_mountpoint(void)
-{
-        const char * const *ptr;
-        char type[100];
-        FILE *fp;
-
-        if (sysfs_found)
-                return (const char *) sysfs_mountpoint;
-
-        ptr = sysfs_known_mountpoints;
-        while (*ptr) {
-                if (sysfs_valid_mountpoint(*ptr) == 0) {
-                        sysfs_found = 1;
-                        strcpy(sysfs_mountpoint, *ptr);
-                        return sysfs_mountpoint;
-                }
-                ptr++;
-        }
-
-        /* give up and parse /proc/mounts */
-        fp = fopen("/proc/mounts", "r");
-        if (fp == NULL)
-                return NULL;
-
-        while (!sysfs_found &&
-               fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
-                      sysfs_mountpoint, type) == 2) {
-
-                if (strcmp(type, "sysfs") == 0)
-                        sysfs_found = 1;
-        }
-
-        fclose(fp);
-
-        return sysfs_found ? sysfs_mountpoint : NULL;
-}
diff --git a/tools/perf/util/sysfs.h b/tools/perf/util/sysfs.h
deleted file mode 100644
index a813b7203938..000000000000
--- a/tools/perf/util/sysfs.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef __SYSFS_H__
-#define __SYSFS_H__
-
-const char *sysfs_find_mountpoint(void);
-
-#endif /* __DEBUGFS_H__ */