tools lib api fs: Make tracing_path_strerror_open message generic

Making tracing_path__strerror_open_tp message generic by mentioning both
debugfs/tracefs words in error message plus the tracing_path instead of
debugfs_mountpoint.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
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: Raphael Beamonte <raphael.beamonte@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1441180605-24737-7-git-send-email-jolsa@kernel.org
[ Add comment for the ENOENT case out of this patch discussion thread ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/lib/api/fs/tracing_path.c b/tools/lib/api/fs/tracing_path.c
index 3b3e4f5fc50bd5980e174a863cbcf3b85a147dc7..1e0bb0da5e4f2b4eb1a5345ba27ca50d91846cdf 100644 (file)
--- a/tools/lib/api/fs/tracing_path.c
+++ b/tools/lib/api/fs/tracing_path.c
@@ -90,33 +90,39 @@ static int strerror_open(int err, char *buf, size_t size, const char *filename)
 
        switch (err) {
        case ENOENT:
-               if (debugfs_configured()) {
+               /*
+                * We will get here if we can't find the tracepoint, but one of
+                * debugfs or tracefs is configured, which means you probably
+                * want some tracepoint which wasn't compiled in your kernel.
+                * - jirka
+                */
+               if (debugfs_configured() || tracefs_configured()) {
                        snprintf(buf, size,
                                 "Error:\tFile %s/%s not found.\n"
                                 "Hint:\tPerhaps this kernel misses some CONFIG_ setting to enable this feature?.\n",
-                                debugfs_mountpoint, filename);
+                                tracing_events_path, filename);
                        break;
                }
                snprintf(buf, size, "%s",
-                        "Error:\tUnable to find debugfs\n"
-                        "Hint:\tWas your kernel compiled with debugfs support?\n"
-                        "Hint:\tIs the debugfs filesystem mounted?\n"
+                        "Error:\tUnable to find debugfs/tracefs\n"
+                        "Hint:\tWas your kernel compiled with debugfs/tracefs support?\n"
+                        "Hint:\tIs the debugfs/tracefs filesystem mounted?\n"
                         "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
                break;
        case EACCES: {
-               const char *mountpoint = debugfs_mountpoint;
+               const char *mountpoint = debugfs_find_mountpoint();
 
-               if (!access(debugfs_mountpoint, R_OK) && strncmp(filename, "tracing/", 8) == 0) {
+               if (!access(mountpoint, R_OK) && strncmp(filename, "tracing/", 8) == 0) {
                        const char *tracefs_mntpoint = tracefs_find_mountpoint();
 
                        if (tracefs_mntpoint)
-                               mountpoint = tracefs_mntpoint;
+                               mountpoint = tracefs_find_mountpoint();
                }
 
                snprintf(buf, size,
                         "Error:\tNo permissions to read %s/%s\n"
                         "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
-                        debugfs_mountpoint, filename, mountpoint);
+                        tracing_events_path, filename, mountpoint);
        }
                break;
        default:
@@ -131,7 +137,7 @@ int tracing_path__strerror_open_tp(int err, char *buf, size_t size, const char *
 {
        char path[PATH_MAX];
 
-       snprintf(path, PATH_MAX, "tracing/events/%s/%s", sys, name ?: "*");
+       snprintf(path, PATH_MAX, "%s/%s", sys, name ?: "*");
 
        return strerror_open(err, buf, size, path);
 }