lkml.org 
[lkml]   [2009]   [Jul]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH 2/2] tracing/filter: remove empty subsystem and it's directory
    From
    Date
    On Thu, 2009-07-09 at 16:22 +0800, Xiao Guangrong wrote:
    > Remove empty subsystem and it's directory when module unload.
    >
    > Before patch:
    > # rmmod trace-events-sample.ko
    > # ls sample
    > enable filter
    >
    > After patch:
    > # rmmod trace-events-sample.ko
    > # ls sample
    > ls: cannot access sample: No such file or directory
    >
    > Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>

    Looks like it does the trick.

    Acked-by: Tom Zanussi <tzanussi@gmail.com>

    > ---
    > kernel/trace/trace.h | 1 +
    > kernel/trace/trace_events.c | 32 +++++++++++++++++++++++++++++++-
    > 2 files changed, 32 insertions(+), 1 deletions(-)
    >
    > diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
    > index 61b4e94..0e7de4b 100644
    > --- a/kernel/trace/trace.h
    > +++ b/kernel/trace/trace.h
    > @@ -780,6 +780,7 @@ struct event_subsystem {
    > const char *name;
    > struct dentry *entry;
    > void *filter;
    > + int nr_events;
    > };
    >
    > struct filter_pred;
    > diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
    > index fecac13..90cf936 100644
    > --- a/kernel/trace/trace_events.c
    > +++ b/kernel/trace/trace_events.c
    > @@ -851,8 +851,10 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
    >
    > /* First see if we did not already create this dir */
    > list_for_each_entry(system, &event_subsystems, list) {
    > - if (strcmp(system->name, name) == 0)
    > + if (strcmp(system->name, name) == 0) {
    > + system->nr_events++;
    > return system->entry;
    > + }
    > }
    >
    > /* need to create new entry */
    > @@ -871,6 +873,7 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
    > return d_events;
    > }
    >
    > + system->nr_events = 1;
    > system->name = kstrdup(name, GFP_KERNEL);
    > if (!system->name) {
    > debugfs_remove(system->entry);
    > @@ -905,6 +908,32 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
    > return system->entry;
    > }
    >
    > +static void remove_subsystem_dir(const char *name)
    > +{
    > + struct event_subsystem *system;
    > +
    > + if (strcmp(name, TRACE_SYSTEM) == 0)
    > + return;
    > +
    > + list_for_each_entry(system, &event_subsystems, list) {
    > + if (strcmp(system->name, name) == 0) {
    > + if (!--system->nr_events) {
    > + struct event_filter *filter = system->filter;
    > +
    > + debugfs_remove_recursive(system->entry);
    > + list_del(&system->list);
    > + if (filter) {
    > + kfree(filter->filter_string);
    > + kfree(filter);
    > + }
    > + kfree(system->name);
    > + kfree(system);
    > + }
    > + break;
    > + }
    > + }
    > +}
    > +
    > static int
    > event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
    > const struct file_operations *id,
    > @@ -1079,6 +1108,7 @@ static void trace_module_remove_events(struct module *mod)
    > list_del(&call->list);
    > trace_destroy_fields(call);
    > destroy_preds(call);
    > + remove_subsystem_dir(call->system);
    > }
    > }
    >



    \
     
     \ /
      Last update: 2009-07-10 06:09    [W:0.025 / U:0.664 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site