Kill tracing_open_generic_file() and tracing_release_generic_file(), they are racy anyway.
Instead, change event_enable_read() and event_enable_write() to rely on event_mutex and file_inode(filp)->i_private != NULL check. trace_array_get() goes away. NOTE! this is actually wrong until we change instance_delete() path to nullify ->i_private. Signed-off-by: Oleg Nesterov <[email protected]> --- kernel/trace/trace_events.c | 62 ++++++++++++++----------------------------- 1 files changed, 20 insertions(+), 42 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index cefbe85..6401b51 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -410,35 +410,6 @@ static void put_system(struct ftrace_subsystem_dir *dir) } /* - * Open and update trace_array ref count. - * Must have the current trace_array passed to it. - */ -static int tracing_open_generic_file(struct inode *inode, struct file *filp) -{ - struct ftrace_event_file *file = inode->i_private; - struct trace_array *tr = file->tr; - int ret; - - if (trace_array_get(tr) < 0) - return -ENODEV; - - ret = tracing_open_generic(inode, filp); - if (ret < 0) - trace_array_put(tr); - return ret; -} - -static int tracing_release_generic_file(struct inode *inode, struct file *filp) -{ - struct ftrace_event_file *file = inode->i_private; - struct trace_array *tr = file->tr; - - trace_array_put(tr); - - return 0; -} - -/* * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events. */ static int @@ -679,15 +650,25 @@ static ssize_t event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { - struct ftrace_event_file *file = filp->private_data; + struct ftrace_event_file *file; + unsigned long flags; char buf[4] = "0"; - if (file->flags & FTRACE_EVENT_FL_ENABLED && - !(file->flags & FTRACE_EVENT_FL_SOFT_DISABLED)) + mutex_lock(&event_mutex); + file = file_inode(filp)->i_private; + if (likely(file)) + flags = file->flags; + mutex_unlock(&event_mutex); + + if (!file) + return -ENODEV; + + if (flags & FTRACE_EVENT_FL_ENABLED && + !(flags & FTRACE_EVENT_FL_SOFT_DISABLED)) strcpy(buf, "1"); - if (file->flags & FTRACE_EVENT_FL_SOFT_DISABLED || - file->flags & FTRACE_EVENT_FL_SOFT_MODE) + if (flags & FTRACE_EVENT_FL_SOFT_DISABLED || + flags & FTRACE_EVENT_FL_SOFT_MODE) strcat(buf, "*"); strcat(buf, "\n"); @@ -699,13 +680,10 @@ static ssize_t event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - struct ftrace_event_file *file = filp->private_data; + struct ftrace_event_file *file; unsigned long val; int ret; - if (!file) - return -EINVAL; - ret = kstrtoul_from_user(ubuf, cnt, 10, &val); if (ret) return ret; @@ -717,8 +695,11 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, switch (val) { case 0: case 1: + ret = -ENODEV; mutex_lock(&event_mutex); - ret = ftrace_event_enable_disable(file, val); + file = file_inode(filp)->i_private; + if (likely(file)) + ret = ftrace_event_enable_disable(file, val); mutex_unlock(&event_mutex); break; @@ -727,7 +708,6 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, } *ppos += cnt; - return ret ? ret : cnt; } @@ -1242,10 +1222,8 @@ static const struct file_operations ftrace_set_event_fops = { }; static const struct file_operations ftrace_enable_fops = { - .open = tracing_open_generic_file, .read = event_enable_read, .write = event_enable_write, - .release = tracing_release_generic_file, .llseek = default_llseek, }; -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
