[PATCH v2] char: misc:use DEFINE_PROC_SHOW_ATTRIBUTE micro to simplify misc proc_fops

[PATCH v2] char: misc:use DEFINE_PROC_SHOW_ATTRIBUTE micro to simplify misc proc_fops

[wujunwen]

DEFINE_PROC_SHOW_ATTRIBUTE is used to simply seq_file flow ,so
we can use it to simplify misc proc_fops.

Signed-off-by: wujunwen <wudaemon@163.com>
---
 drivers/char/misc.c | 41 ++++++++++++++---------------------------
 1 file changed, 14 insertions(+), 27 deletions(-)

diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index ca5141ed5ef3..076b7f08aa7a 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -64,40 +64,23 @@ static DEFINE_MUTEX(misc_mtx);
 static DECLARE_BITMAP(misc_minors, DYNAMIC_MINORS);
 
 #ifdef CONFIG_PROC_FS
-static void *misc_seq_start(struct seq_file *seq, loff_t *pos)
-{
-	mutex_lock(&misc_mtx);
-	return seq_list_start(&misc_list, *pos);
-}
 
-static void *misc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+static int misc_show(struct seq_file *seq, void *v)
 {
-	return seq_list_next(v, &misc_list, pos);
-}
+	const struct miscdevice *p;
 
-static void misc_seq_stop(struct seq_file *seq, void *v)
-{
+	mutex_lock(&misc_mtx);
+	list_for_each_entry(p, &misc_list, list) {
+		seq_printf(seq, "%3i %s\n", p->minor, p->name ? p->name : "");
+	}
 	mutex_unlock(&misc_mtx);
-}
-
-static int misc_seq_show(struct seq_file *seq, void *v)
-{
-	const struct miscdevice *p = list_entry(v, struct miscdevice, list);
-
-	seq_printf(seq, "%3i %s\n", p->minor, p->name ? p->name : "");
 	return 0;
 }
 
-
-static const struct seq_operations misc_seq_ops = {
-	.start = misc_seq_start,
-	.next  = misc_seq_next,
-	.stop  = misc_seq_stop,
-	.show  = misc_seq_show,
-};
+DEFINE_PROC_SHOW_ATTRIBUTE(misc);
 #endif
 
-static int misc_open(struct inode *inode, struct file *file)
+static int misc_fops_open(struct inode *inode, struct file *file)
 {
 	int minor = iminor(inode);
 	struct miscdevice *c;
@@ -148,7 +131,7 @@ static struct class *misc_class;
 
 static const struct file_operations misc_fops = {
 	.owner		= THIS_MODULE,
-	.open		= misc_open,
+	.open		= misc_fops_open,
 	.llseek		= noop_llseek,
 };
 
@@ -266,9 +249,11 @@ static char *misc_devnode(struct device *dev, umode_t *mode)
 static int __init misc_init(void)
 {
 	int err;
+#ifdef CONFIG_PROC_FS
 	struct proc_dir_entry *ret;
 
-	ret = proc_create_seq("misc", 0, NULL, &misc_seq_ops);
+	ret = proc_create("misc", 0, NULL, &misc_proc_ops);
+#endif
 	misc_class = class_create(THIS_MODULE, "misc");
 	err = PTR_ERR(misc_class);
 	if (IS_ERR(misc_class))
@@ -284,8 +269,10 @@ static int __init misc_init(void)
 	pr_err("unable to get major %d for misc devices\n", MISC_MAJOR);
 	class_destroy(misc_class);
 fail_remove:
+#ifdef CONFIG_PROC_FS
 	if (ret)
 		remove_proc_entry("misc", NULL);
+#endif
 	return err;
 }
 subsys_initcall(misc_init);
-- 
2.25.1

Re: [PATCH v2] char: misc:use DEFINE_PROC_SHOW_ATTRIBUTE micro to simplify misc proc_fops

[Greg KH]

On Sun, Mar 27, 2022 at 02:32:54PM +0000, wujunwen wrote:
> DEFINE_PROC_SHOW_ATTRIBUTE is used to simply seq_file flow ,so
> we can use it to simplify misc proc_fops.
> 
> Signed-off-by: wujunwen <wudaemon@163.com>
> ---
>  drivers/char/misc.c | 41 ++++++++++++++---------------------------
>  1 file changed, 14 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/char/misc.c b/drivers/char/misc.c
> index ca5141ed5ef3..076b7f08aa7a 100644
> --- a/drivers/char/misc.c
> +++ b/drivers/char/misc.c
> @@ -64,40 +64,23 @@ static DEFINE_MUTEX(misc_mtx);
>  static DECLARE_BITMAP(misc_minors, DYNAMIC_MINORS);
>  
>  #ifdef CONFIG_PROC_FS
> -static void *misc_seq_start(struct seq_file *seq, loff_t *pos)
> -{
> -	mutex_lock(&misc_mtx);
> -	return seq_list_start(&misc_list, *pos);
> -}
>  
> -static void *misc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
> +static int misc_show(struct seq_file *seq, void *v)
>  {
> -	return seq_list_next(v, &misc_list, pos);
> -}
> +	const struct miscdevice *p;
>  
> -static void misc_seq_stop(struct seq_file *seq, void *v)
> -{
> +	mutex_lock(&misc_mtx);
> +	list_for_each_entry(p, &misc_list, list) {
> +		seq_printf(seq, "%3i %s\n", p->minor, p->name ? p->name : "");
> +	}
>  	mutex_unlock(&misc_mtx);
> -}
> -
> -static int misc_seq_show(struct seq_file *seq, void *v)
> -{
> -	const struct miscdevice *p = list_entry(v, struct miscdevice, list);
> -
> -	seq_printf(seq, "%3i %s\n", p->minor, p->name ? p->name : "");
>  	return 0;
>  }
>  
> -
> -static const struct seq_operations misc_seq_ops = {
> -	.start = misc_seq_start,
> -	.next  = misc_seq_next,
> -	.stop  = misc_seq_stop,
> -	.show  = misc_seq_show,
> -};
> +DEFINE_PROC_SHOW_ATTRIBUTE(misc);
>  #endif
>  
> -static int misc_open(struct inode *inode, struct file *file)
> +static int misc_fops_open(struct inode *inode, struct file *file)
>  {
>  	int minor = iminor(inode);
>  	struct miscdevice *c;
> @@ -148,7 +131,7 @@ static struct class *misc_class;
>  
>  static const struct file_operations misc_fops = {
>  	.owner		= THIS_MODULE,
> -	.open		= misc_open,
> +	.open		= misc_fops_open,
>  	.llseek		= noop_llseek,
>  };
>  
> @@ -266,9 +249,11 @@ static char *misc_devnode(struct device *dev, umode_t *mode)
>  static int __init misc_init(void)
>  {
>  	int err;
> +#ifdef CONFIG_PROC_FS
>  	struct proc_dir_entry *ret;
>  
> -	ret = proc_create_seq("misc", 0, NULL, &misc_seq_ops);
> +	ret = proc_create("misc", 0, NULL, &misc_proc_ops);
> +#endif
>  	misc_class = class_create(THIS_MODULE, "misc");
>  	err = PTR_ERR(misc_class);
>  	if (IS_ERR(misc_class))
> @@ -284,8 +269,10 @@ static int __init misc_init(void)
>  	pr_err("unable to get major %d for misc devices\n", MISC_MAJOR);
>  	class_destroy(misc_class);
>  fail_remove:
> +#ifdef CONFIG_PROC_FS
>  	if (ret)
>  		remove_proc_entry("misc", NULL);
> +#endif
>  	return err;
>  }
>  subsys_initcall(misc_init);
> -- 
> 2.25.1
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- This looks like a new version of a previously submitted patch, but you
  did not list below the --- line any changes from the previous version.
  Please read the section entitled "The canonical patch format" in the
  kernel file, Documentation/SubmittingPatches for what needs to be done
  here to properly describe this.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot

Re: Re: [PATCH v2] char: misc:use DEFINE_PROC_SHOW_ATTRIBUTE micro to simplify misc proc_fops

[Greg KH]

On Wed, Mar 30, 2022 at 11:11:48PM +0800, 吴俊文 wrote:
> Dear Greg:
> It means I should list  the reason  why I ptach a new verson?like this:

I do not know what you are referring to, sorry.  Also, html email is
rejected by the mailing list and out tools, please fix.

thanks,

greg k-h

Re: Re: Re: [PATCH v2] char: misc:use DEFINE_PROC_SHOW_ATTRIBUTE micro to simplify misc proc_fops

[Greg KH]

On Wed, Mar 30, 2022 at 11:44:21PM +0800, 吴俊文 wrote:
> sorry ,I just send a picture not text.It refers I show list  the reason why I patch a newer verson?like this:
> 
>   <commit message>
> 
>   ...
> 
>   Signed-off-by: Author <author@mail>
> 
>   ---
> 
>   V2 -> V3: Removed redundant helper function
> 
>   V1 -> V2: Cleaned up coding style and addressed review comments
> 
> 
> 
> 
>   path/to/file | 5+++--
> 
>   ...
> 

As my bot showed, this is documented in the kernel Documentation/ file
for how to do this.  And yes, that does look correct.

thanks,

greg k-h