[tip:tracing/urgent] tracing: Simplify trace_option_write()

From: tip-bot for Li Zefan
Date: Mon Dec 14 2009 - 04:48:31 EST


Commit-ID: 8d18eaaff5acaa58369be342c86e607643ce10c7
Gitweb: http://git.kernel.org/tip/8d18eaaff5acaa58369be342c86e607643ce10c7
Author: Li Zefan <lizf@xxxxxxxxxxxxxx>
AuthorDate: Tue, 8 Dec 2009 11:17:06 +0800
Committer: Frederic Weisbecker <fweisbec@xxxxxxxxx>
CommitDate: Sun, 13 Dec 2009 18:37:28 +0100

tracing: Simplify trace_option_write()

- remove duplicate code inside trace_options_write()
- extract duplicate code in trace_options_write() and set_tracer_option()

Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
LKML-Reference: <4B1DC532.9010802@xxxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
kernel/trace/trace.c | 85 ++++++++++++++++++-------------------------------
1 files changed, 31 insertions(+), 54 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 898409d..0507600 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2343,38 +2343,39 @@ static int tracing_trace_options_show(struct seq_file *m, void *v)
return 0;
}

+static int __set_tracer_option(struct tracer *trace,
+ struct tracer_flags *tracer_flags,
+ struct tracer_opt *opts, int neg)
+{
+ int ret;
+
+ ret = trace->set_flag(tracer_flags->val, opts->bit, !neg);
+ if (ret)
+ return ret;
+
+ if (neg)
+ tracer_flags->val &= ~opts->bit;
+ else
+ tracer_flags->val |= opts->bit;
+ return 0;
+}
+
/* Try to assign a tracer specific option */
static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
{
struct tracer_flags *tracer_flags = trace->flags;
struct tracer_opt *opts = NULL;
- int ret = 0, i = 0;
- int len;
+ int i;

for (i = 0; tracer_flags->opts[i].name; i++) {
opts = &tracer_flags->opts[i];
- len = strlen(opts->name);

- if (strncmp(cmp, opts->name, len) == 0) {
- ret = trace->set_flag(tracer_flags->val,
- opts->bit, !neg);
- break;
- }
+ if (strcmp(cmp, opts->name) == 0)
+ return __set_tracer_option(trace, trace->flags,
+ opts, neg);
}
- /* Not found */
- if (!tracer_flags->opts[i].name)
- return -EINVAL;

- /* Refused to handle */
- if (ret)
- return ret;
-
- if (neg)
- tracer_flags->val &= ~opts->bit;
- else
- tracer_flags->val |= opts->bit;
-
- return 0;
+ return -EINVAL;
}

static void set_tracer_flags(unsigned int mask, int enabled)
@@ -2394,7 +2395,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[64];
- char *cmp = buf;
+ char *cmp;
int neg = 0;
int ret;
int i;
@@ -2406,16 +2407,15 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
return -EFAULT;

buf[cnt] = 0;
+ cmp = strstrip(buf);

- if (strncmp(buf, "no", 2) == 0) {
+ if (strncmp(cmp, "no", 2) == 0) {
neg = 1;
cmp += 2;
}

for (i = 0; trace_options[i]; i++) {
- int len = strlen(trace_options[i]);
-
- if (strncmp(cmp, trace_options[i], len) == 0) {
+ if (strcmp(cmp, trace_options[i]) == 0) {
set_tracer_flags(1 << i, !neg);
break;
}
@@ -3927,39 +3927,16 @@ trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
if (ret < 0)
return ret;

- ret = 0;
- switch (val) {
- case 0:
- /* do nothing if already cleared */
- if (!(topt->flags->val & topt->opt->bit))
- break;
-
- mutex_lock(&trace_types_lock);
- if (current_trace->set_flag)
- ret = current_trace->set_flag(topt->flags->val,
- topt->opt->bit, 0);
- mutex_unlock(&trace_types_lock);
- if (ret)
- return ret;
- topt->flags->val &= ~topt->opt->bit;
- break;
- case 1:
- /* do nothing if already set */
- if (topt->flags->val & topt->opt->bit)
- break;
+ if (val != 0 && val != 1)
+ return -EINVAL;

+ if (!!(topt->flags->val & topt->opt->bit) != val) {
mutex_lock(&trace_types_lock);
- if (current_trace->set_flag)
- ret = current_trace->set_flag(topt->flags->val,
- topt->opt->bit, 1);
+ ret = __set_tracer_option(current_trace, topt->flags,
+ topt->opt, val);
mutex_unlock(&trace_types_lock);
if (ret)
return ret;
- topt->flags->val |= topt->opt->bit;
- break;
-
- default:
- return -EINVAL;
}

*ppos += cnt;
--
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