diff options
| -rw-r--r-- | Documentation/ABI/obsolete/automount-tracefs-debugfs | 20 | ||||
| -rw-r--r-- | kernel/trace/Kconfig | 13 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 14 |
3 files changed, 43 insertions, 4 deletions
diff --git a/Documentation/ABI/obsolete/automount-tracefs-debugfs b/Documentation/ABI/obsolete/automount-tracefs-debugfs new file mode 100644 index 000000000000..a5196ec78cb5 --- /dev/null +++ b/Documentation/ABI/obsolete/automount-tracefs-debugfs @@ -0,0 +1,20 @@ +What: /sys/kernel/debug/tracing +Date: May 2008 +KernelVersion: 2.6.27 +Contact: linux-trace-kernel@vger.kernel.org +Description: + + The ftrace was first added to the kernel, its interface was placed + into the debugfs file system under the "tracing" directory. Access + to the files were in /sys/kernel/debug/tracing. As systems wanted + access to the tracing interface without having to enable debugfs, a + new interface was created called "tracefs". This was a stand alone + file system and was usually mounted in /sys/kernel/tracing. + + To allow older tooling to continue to operate, when mounting + debugfs, the tracefs file system would automatically get mounted in + the "tracing" directory of debugfs. The tracefs interface was added + in January 2015 in the v4.1 kernel. + + All tooling should now be using tracefs directly and the "tracing" + directory in debugfs should be removed by January 2030. diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a3f35c7d83b6..93e8e7fc11c0 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -199,6 +199,19 @@ menuconfig FTRACE if FTRACE +config TRACEFS_AUTOMOUNT_DEPRECATED + bool "Automount tracefs on debugfs [DEPRECATED]" + depends on TRACING + default y + help + The tracing interface was moved from /sys/kernel/debug/tracing + to /sys/kernel/tracing in 2015, but the tracing file system + was still automounted in /sys/kernel/debug for backward + compatibility with tooling. + + The new interface has been around for more than 10 years and + the old debug mount will soon be removed. + config BOOTTIME_TRACING bool "Boot-time Tracing support" depends on TRACING diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0dff4298fc0e..06ab5b7a8711 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6296,7 +6296,7 @@ static bool tracer_options_updated; static void add_tracer_options(struct trace_array *tr, struct tracer *t) { /* Only enable if the directory has been created already. */ - if (!tr->dir) + if (!tr->dir && !(tr->flags & TRACE_ARRAY_FL_GLOBAL)) return; /* Only create trace option files after update_tracer_options finish */ @@ -8977,13 +8977,13 @@ static inline __init int register_snapshot_cmd(void) { return 0; } static struct dentry *tracing_get_dentry(struct trace_array *tr) { - if (WARN_ON(!tr->dir)) - return ERR_PTR(-ENODEV); - /* Top directory uses NULL as the parent */ if (tr->flags & TRACE_ARRAY_FL_GLOBAL) return NULL; + if (WARN_ON(!tr->dir)) + return ERR_PTR(-ENODEV); + /* All sub buffers have a descriptor */ return tr->dir; } @@ -10249,6 +10249,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) ftrace_init_tracefs(tr, d_tracer); } +#ifdef CONFIG_TRACEFS_AUTOMOUNT_DEPRECATED static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore) { struct vfsmount *mnt; @@ -10270,6 +10271,8 @@ static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore) if (IS_ERR(fc)) return ERR_CAST(fc); + pr_warn("NOTICE: Automounting of tracing to debugfs is deprecated and will be removed in 2030\n"); + ret = vfs_parse_fs_string(fc, "source", "tracefs", strlen("tracefs")); if (!ret) @@ -10280,6 +10283,7 @@ static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore) put_fs_context(fc); return mnt; } +#endif /** * tracing_init_dentry - initialize top level trace array @@ -10304,6 +10308,7 @@ int tracing_init_dentry(void) if (WARN_ON(!tracefs_initialized())) return -ENODEV; +#ifdef CONFIG_TRACEFS_AUTOMOUNT_DEPRECATED /* * As there may still be users that expect the tracing * files to exist in debugfs/tracing, we must automount @@ -10312,6 +10317,7 @@ int tracing_init_dentry(void) */ tr->dir = debugfs_create_automount("tracing", NULL, trace_automount, NULL); +#endif return 0; } |