[PATCH v2] ASoC: use seq_file to dump the contents of dai_list,platform_list and codec_list

[PATCH v2] ASoC: use seq_file to dump the contents of dai_list,platform_list and codec_list

[Donglin Peng]

Now the debugfs files dais/platforms/codecs have a size limit PAGE_SIZE and
the user can not see the whole contents of dai_list/platform_list/codec_list
when they are larger than this limit.

This patch uses seq_file instead to make sure dais/platforms/codecs show the
full contents of dai_list/platform_list/codec_list.

Signed-off-by: Donglin Peng <dolinux.peng@gmail.com>
---
Changelog
v2
 -fix commit log error

 sound/soc/soc-core.c | 111 +++++++++++++++++----------------------------------
 1 file changed, 37 insertions(+), 74 deletions(-)

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index c0edac80df34..7b582112e3fc 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -349,120 +349,84 @@ static void soc_init_codec_debugfs(struct snd_soc_component *component)
 			"ASoC: Failed to create codec register debugfs file\n");
 }
 
-static ssize_t codec_list_read_file(struct file *file, char __user *user_buf,
-				    size_t count, loff_t *ppos)
+static int codec_list_seq_show(struct seq_file *m, void *v)
 {
-	char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	ssize_t len, ret = 0;
 	struct snd_soc_codec *codec;
 
-	if (!buf)
-		return -ENOMEM;
-
 	mutex_lock(&client_mutex);
 
-	list_for_each_entry(codec, &codec_list, list) {
-		len = snprintf(buf + ret, PAGE_SIZE - ret, "%s\n",
-			       codec->component.name);
-		if (len >= 0)
-			ret += len;
-		if (ret > PAGE_SIZE) {
-			ret = PAGE_SIZE;
-			break;
-		}
-	}
+	list_for_each_entry(codec, &codec_list, list)
+		seq_printf(m, "%s\n", codec->component.name);
 
 	mutex_unlock(&client_mutex);
 
-	if (ret >= 0)
-		ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
-
-	kfree(buf);
+	return 0;
+}
 
-	return ret;
+static int codec_list_seq_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, codec_list_seq_show, NULL);
 }
 
 static const struct file_operations codec_list_fops = {
-	.read = codec_list_read_file,
-	.llseek = default_llseek,/* read accesses f_pos */
+	.open = codec_list_seq_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
 };
 
-static ssize_t dai_list_read_file(struct file *file, char __user *user_buf,
-				  size_t count, loff_t *ppos)
+static int dai_list_seq_show(struct seq_file *m, void *v)
 {
-	char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	ssize_t len, ret = 0;
 	struct snd_soc_component *component;
 	struct snd_soc_dai *dai;
 
-	if (!buf)
-		return -ENOMEM;
-
 	mutex_lock(&client_mutex);
 
-	list_for_each_entry(component, &component_list, list) {
-		list_for_each_entry(dai, &component->dai_list, list) {
-			len = snprintf(buf + ret, PAGE_SIZE - ret, "%s\n",
-				dai->name);
-			if (len >= 0)
-				ret += len;
-			if (ret > PAGE_SIZE) {
-				ret = PAGE_SIZE;
-				break;
-			}
-		}
-	}
+	list_for_each_entry(component, &component_list, list)
+		list_for_each_entry(dai, &component->dai_list, list)
+			seq_printf(m, "%s\n", dai->name);
 
 	mutex_unlock(&client_mutex);
 
-	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
-
-	kfree(buf);
+	return 0;
+}
 
-	return ret;
+static int dai_list_seq_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, dai_list_seq_show, NULL);
 }
 
 static const struct file_operations dai_list_fops = {
-	.read = dai_list_read_file,
-	.llseek = default_llseek,/* read accesses f_pos */
+	.open = dai_list_seq_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
 };
 
-static ssize_t platform_list_read_file(struct file *file,
-				       char __user *user_buf,
-				       size_t count, loff_t *ppos)
+static int platform_list_seq_show(struct seq_file *m, void *v)
 {
-	char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	ssize_t len, ret = 0;
 	struct snd_soc_platform *platform;
 
-	if (!buf)
-		return -ENOMEM;
-
 	mutex_lock(&client_mutex);
 
-	list_for_each_entry(platform, &platform_list, list) {
-		len = snprintf(buf + ret, PAGE_SIZE - ret, "%s\n",
-			       platform->component.name);
-		if (len >= 0)
-			ret += len;
-		if (ret > PAGE_SIZE) {
-			ret = PAGE_SIZE;
-			break;
-		}
-	}
+	list_for_each_entry(platform, &platform_list, list)
+		seq_printf(m, "%s\n", platform->component.name);
 
 	mutex_unlock(&client_mutex);
 
-	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
-
-	kfree(buf);
+	return 0;
+}
 
-	return ret;
+static int platform_list_seq_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, platform_list_seq_show, NULL);
 }
 
 static const struct file_operations platform_list_fops = {
-	.read = platform_list_read_file,
-	.llseek = default_llseek,/* read accesses f_pos */
+	.open = platform_list_seq_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
 };
 
 static void soc_init_card_debugfs(struct snd_soc_card *card)
@@ -491,7 +455,6 @@ static void soc_cleanup_card_debugfs(struct snd_soc_card *card)
 	debugfs_remove_recursive(card->debugfs_card_root);
 }
 
-
 static void snd_soc_debugfs_init(void)
 {
 	snd_soc_debugfs_root = debugfs_create_dir("asoc", NULL);
-- 
2.15.1

Re: [PATCH v2] ASoC: use seq_file to dump the contents of dai_list,platform_list and codec_list

[Andy Shevchenko]

On Thu, Jan 18, 2018 at 7:31 AM, Donglin Peng <dolinux.peng@gmail.com> wrote:
> Now the debugfs files dais/platforms/codecs have a size limit PAGE_SIZE and
> the user can not see the whole contents of dai_list/platform_list/codec_list
> when they are larger than this limit.
>
> This patch uses seq_file instead to make sure dais/platforms/codecs show the
> full contents of dai_list/platform_list/codec_list.

If it's not critical, I would suggest to wait till v4.16-rc1, where I
would like to push [1], and switch to DEFINE_SHOW_ATTRIBUTE() macro.


> +static int codec_list_seq_open(struct inode *inode, struct file *file)
> +{
> +       return single_open(file, codec_list_seq_show, NULL);
>  }
>
>  static const struct file_operations codec_list_fops = {
> +       .open = codec_list_seq_open,
> +       .read = seq_read,
> +       .llseek = seq_lseek,
> +       .release = single_release,
>  };

This will be just

DEFINE_SHOW_ATTRIBUTE(codec_list_seq);

> +static int dai_list_seq_open(struct inode *inode, struct file *file)
> +{
> +       return single_open(file, dai_list_seq_show, NULL);
>  }
>
>  static const struct file_operations dai_list_fops = {
> +       .open = dai_list_seq_open,
> +       .read = seq_read,
> +       .llseek = seq_lseek,
> +       .release = single_release,
>  };

Ditto.

> +static int platform_list_seq_open(struct inode *inode, struct file *file)
> +{
> +       return single_open(file, platform_list_seq_show, NULL);
>  }
>
>  static const struct file_operations platform_list_fops = {
> +       .open = platform_list_seq_open,
> +       .read = seq_read,
> +       .llseek = seq_lseek,
> +       .release = single_release,
>  };

Ditto.

[1]: https://patchwork.kernel.org/patch/10178813/

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2] ASoC: use seq_file to dump the contents of dai_list,platform_list and codec_list

[Mark Brown]

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On Tue, Jan 23, 2018 at 07:08:15PM +0200, Andy Shevchenko wrote:

> If it's not critical, I would suggest to wait till v4.16-rc1, where I
> would like to push [1], and switch to DEFINE_SHOW_ATTRIBUTE() macro.

Too late, I already applied this - a further conversion for the new
macro would be good.

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Re: [PATCH v2] ASoC: use seq_file to dump the contents of dai_list,platform_list and codec_list

[Donglin Peng]

On Wed, Jan 24, 2018 at 1:37 AM, Mark Brown <broonie@kernel.org> wrote:
> On Tue, Jan 23, 2018 at 07:08:15PM +0200, Andy Shevchenko wrote:
>
>> If it's not critical, I would suggest to wait till v4.16-rc1, where I
>> would like to push [1], and switch to DEFINE_SHOW_ATTRIBUTE() macro.
>
> Too late, I already applied this - a further conversion for the new
> macro would be good.
I can send another patch after the following patch is merged:
https://patchwork.kernel.org/patch/10178813/

Re: [PATCH v2] ASoC: use seq_file to dump the contents of dai_list,platform_list and codec_list

[Mark Brown]

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On Fri, Jan 26, 2018 at 03:16:00PM +0800, Donglin Peng wrote:
> On Wed, Jan 24, 2018 at 1:37 AM, Mark Brown <broonie@kernel.org> wrote:

> > Too late, I already applied this - a further conversion for the new
> > macro would be good.

> I can send another patch after the following patch is merged:
> https://patchwork.kernel.org/patch/10178813/

Yes, please - that'd be great!

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Re: [PATCH v2] ASoC: use seq_file to dump the contents of dai_list,platform_list and codec_list

[Andy Shevchenko]

On Fri, Jan 26, 2018 at 1:28 PM, Mark Brown <broonie@kernel.org> wrote:
> On Fri, Jan 26, 2018 at 03:16:00PM +0800, Donglin Peng wrote:
>> On Wed, Jan 24, 2018 at 1:37 AM, Mark Brown <broonie@kernel.org> wrote:
>
>> > Too late, I already applied this - a further conversion for the new
>> > macro would be good.
>
>> I can send another patch after the following patch is merged:
>> https://patchwork.kernel.org/patch/10178813/
>
> Yes, please - that'd be great!

I have sent PR to Linus. If everything goes fine, it will be in
upstream today evening.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2] ASoC: use seq_file to dump the contents of dai_list,platform_list and codec_list

[Andy Shevchenko]

On Fri, Jan 26, 2018 at 9:16 AM, Donglin Peng <dolinux.peng@gmail.com> wrote:
> On Wed, Jan 24, 2018 at 1:37 AM, Mark Brown <broonie@kernel.org> wrote:
>> On Tue, Jan 23, 2018 at 07:08:15PM +0200, Andy Shevchenko wrote:
>>
>>> If it's not critical, I would suggest to wait till v4.16-rc1, where I
>>> would like to push [1], and switch to DEFINE_SHOW_ATTRIBUTE() macro.
>>
>> Too late, I already applied this - a further conversion for the new
>> macro would be good.
> I can send another patch after the following patch is merged:
> https://patchwork.kernel.org/patch/10178813/

It's merged. I think whenever Mark switched his repositories for new
cycle you may be able to submit a patch.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2] ASoC: use seq_file to dump the contents of dai_list,platform_list and codec_list

[Mark Brown]

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On Thu, Feb 08, 2018 at 04:25:10PM +0200, Andy Shevchenko wrote:
> On Fri, Jan 26, 2018 at 9:16 AM, Donglin Peng <dolinux.peng@gmail.com> wrote:

> > I can send another patch after the following patch is merged:
> > https://patchwork.kernel.org/patch/10178813/

> It's merged. I think whenever Mark switched his repositories for new
> cycle you may be able to submit a patch.

Send it any time, I'll just not apply it until after -rc1 comes out.

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Re: [PATCH v2] ASoC: use seq_file to dump the contents of dai_list,platform_list and codec_list

[Donglin Peng]

Okay, I will send it later.

On Thu, Feb 8, 2018 at 11:42 PM, Mark Brown <broonie@kernel.org> wrote:
> On Thu, Feb 08, 2018 at 04:25:10PM +0200, Andy Shevchenko wrote:
>> On Fri, Jan 26, 2018 at 9:16 AM, Donglin Peng <dolinux.peng@gmail.com> wrote:
>
>> > I can send another patch after the following patch is merged:
>> > https://patchwork.kernel.org/patch/10178813/
>
>> It's merged. I think whenever Mark switched his repositories for new
>> cycle you may be able to submit a patch.
>
> Send it any time, I'll just not apply it until after -rc1 comes out.