Re: [PATCH 16/39] ipmi: simplify procfs code

[Corey Minyard]

On 04/19/2018 07:41 AM, Christoph Hellwig wrote:
> Use remove_proc_subtree to remove the whole subtree on cleanup instead
> of a hand rolled list of proc entries, unwind the registration loop into
> individual calls.  Switch to use proc_create_single to further simplify
> the code.

I'm yanking all the proc code out of the IPMI driver in 3.18. So this 
is probably
not necessary.

Thanks,

-corey

> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
>   drivers/char/ipmi/ipmi_msghandler.c | 150 +++++-----------------------
>   drivers/char/ipmi/ipmi_si_intf.c    |  47 +--------
>   drivers/char/ipmi/ipmi_ssif.c       |  34 +------
>   include/linux/ipmi_smi.h            |   8 +-
>   4 files changed, 33 insertions(+), 206 deletions(-)
>
> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> index 361148938801..c18db313e4c4 100644
> --- a/drivers/char/ipmi/ipmi_msghandler.c
> +++ b/drivers/char/ipmi/ipmi_msghandler.c
> @@ -247,13 +247,6 @@ struct ipmi_my_addrinfo {
>   	unsigned char lun;
>   };
>   
> -#ifdef CONFIG_IPMI_PROC_INTERFACE
> -struct ipmi_proc_entry {
> -	char                   *name;
> -	struct ipmi_proc_entry *next;
> -};
> -#endif
> -
>   /*
>    * Note that the product id, manufacturer id, guid, and device id are
>    * immutable in this structure, so dyn_mutex is not required for
> @@ -430,10 +423,6 @@ struct ipmi_smi {
>   	void                     *send_info;
>   
>   #ifdef CONFIG_IPMI_PROC_INTERFACE
> -	/* A list of proc entries for this interface. */
> -	struct mutex           proc_entry_lock;
> -	struct ipmi_proc_entry *proc_entries;
> -
>   	struct proc_dir_entry *proc_dir;
>   	char                  proc_dir_name[10];
>   #endif
> @@ -2358,18 +2347,6 @@ static int smi_ipmb_proc_show(struct seq_file *m, void *v)
>   	return 0;
>   }
>   
> -static int smi_ipmb_proc_open(struct inode *inode, struct file *file)
> -{
> -	return single_open(file, smi_ipmb_proc_show, PDE_DATA(inode));
> -}
> -
> -static const struct file_operations smi_ipmb_proc_ops = {
> -	.open		= smi_ipmb_proc_open,
> -	.read		= seq_read,
> -	.llseek		= seq_lseek,
> -	.release	= single_release,
> -};
> -
>   static int smi_version_proc_show(struct seq_file *m, void *v)
>   {
>   	ipmi_smi_t intf = m->private;
> @@ -2387,18 +2364,6 @@ static int smi_version_proc_show(struct seq_file *m, void *v)
>   	return 0;
>   }
>   
> -static int smi_version_proc_open(struct inode *inode, struct file *file)
> -{
> -	return single_open(file, smi_version_proc_show, PDE_DATA(inode));
> -}
> -
> -static const struct file_operations smi_version_proc_ops = {
> -	.open		= smi_version_proc_open,
> -	.read		= seq_read,
> -	.llseek		= seq_lseek,
> -	.release	= single_release,
> -};
> -
>   static int smi_stats_proc_show(struct seq_file *m, void *v)
>   {
>   	ipmi_smi_t intf = m->private;
> @@ -2462,95 +2427,45 @@ static int smi_stats_proc_show(struct seq_file *m, void *v)
>   	return 0;
>   }
>   
> -static int smi_stats_proc_open(struct inode *inode, struct file *file)
> -{
> -	return single_open(file, smi_stats_proc_show, PDE_DATA(inode));
> -}
> -
> -static const struct file_operations smi_stats_proc_ops = {
> -	.open		= smi_stats_proc_open,
> -	.read		= seq_read,
> -	.llseek		= seq_lseek,
> -	.release	= single_release,
> -};
> -
>   int ipmi_smi_add_proc_entry(ipmi_smi_t smi, char *name,
> -			    const struct file_operations *proc_ops,
> -			    void *data)
> +		int (*show)(struct seq_file *, void *), void *data)
>   {
> -	int                    rv = 0;
> -	struct proc_dir_entry  *file;
> -	struct ipmi_proc_entry *entry;
> -
> -	/* Create a list element. */
> -	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
> -	if (!entry)
> +	if (!proc_create_single_data(name, 0, smi->proc_dir, show, data))
>   		return -ENOMEM;
> -	entry->name = kstrdup(name, GFP_KERNEL);
> -	if (!entry->name) {
> -		kfree(entry);
> -		return -ENOMEM;
> -	}
> -
> -	file = proc_create_data(name, 0, smi->proc_dir, proc_ops, data);
> -	if (!file) {
> -		kfree(entry->name);
> -		kfree(entry);
> -		rv = -ENOMEM;
> -	} else {
> -		mutex_lock(&smi->proc_entry_lock);
> -		/* Stick it on the list. */
> -		entry->next = smi->proc_entries;
> -		smi->proc_entries = entry;
> -		mutex_unlock(&smi->proc_entry_lock);
> -	}
> -
> -	return rv;
> +	return 0;
>   }
>   EXPORT_SYMBOL(ipmi_smi_add_proc_entry);
>   
>   static int add_proc_entries(ipmi_smi_t smi, int num)
>   {
> -	int rv = 0;
> -
>   	sprintf(smi->proc_dir_name, "%d", num);
>   	smi->proc_dir = proc_mkdir(smi->proc_dir_name, proc_ipmi_root);
>   	if (!smi->proc_dir)
> -		rv = -ENOMEM;
> -
> -	if (rv == 0)
> -		rv = ipmi_smi_add_proc_entry(smi, "stats",
> -					     &smi_stats_proc_ops,
> -					     smi);
> -
> -	if (rv == 0)
> -		rv = ipmi_smi_add_proc_entry(smi, "ipmb",
> -					     &smi_ipmb_proc_ops,
> -					     smi);
> -
> -	if (rv == 0)
> -		rv = ipmi_smi_add_proc_entry(smi, "version",
> -					     &smi_version_proc_ops,
> -					     smi);
> -
> -	return rv;
> +		return -ENOMEM;
> +	if (!proc_create_single_data("stats", 0, smi->proc_dir,
> +			smi_stats_proc_show, smi))
> +		return -ENOMEM;
> +	if (!proc_create_single_data("ipmb", 0, smi->proc_dir,
> +			smi_ipmb_proc_show, smi))
> +		return -ENOMEM;
> +	if (!proc_create_single_data("version", 0, smi->proc_dir,
> +			smi_version_proc_show, smi))
> +		return -ENOMEM;
> +	return 0;
>   }
>   
>   static void remove_proc_entries(ipmi_smi_t smi)
>   {
> -	struct ipmi_proc_entry *entry;
> -
> -	mutex_lock(&smi->proc_entry_lock);
> -	while (smi->proc_entries) {
> -		entry = smi->proc_entries;
> -		smi->proc_entries = entry->next;
> -
> -		remove_proc_entry(entry->name, smi->proc_dir);
> -		kfree(entry->name);
> -		kfree(entry);
> -	}
> -	mutex_unlock(&smi->proc_entry_lock);
> -	remove_proc_entry(smi->proc_dir_name, proc_ipmi_root);
> +	if (smi->proc_dir)
> +		remove_proc_subtree(smi->proc_dir_name, proc_ipmi_root);
> +}
> +#else
> +static int add_proc_entries(ipmi_smi_t smi, int num)
> +{
> +	return 0;
> +}
> +static void remove_proc_entries(ipmi_smi_t smi)
> +{
>   }
>   #endif /* CONFIG_IPMI_PROC_INTERFACE */
>   
> @@ -3386,9 +3301,6 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>   		intf->seq_table[j].seqid = 0;
>   	}
>   	intf->curr_seq = 0;
> -#ifdef CONFIG_IPMI_PROC_INTERFACE
> -	mutex_init(&intf->proc_entry_lock);
> -#endif
>   	spin_lock_init(&intf->waiting_rcv_msgs_lock);
>   	INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
>   	tasklet_init(&intf->recv_tasklet,
> @@ -3410,10 +3322,6 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>   	for (i = 0; i < IPMI_NUM_STATS; i++)
>   		atomic_set(&intf->stats[i], 0);
>   
> -#ifdef CONFIG_IPMI_PROC_INTERFACE
> -	intf->proc_dir = NULL;
> -#endif
> -
>   	mutex_lock(&smi_watchers_mutex);
>   	mutex_lock(&ipmi_interfaces_mutex);
>   	/* Look for a hole in the numbers. */
> @@ -3448,17 +3356,11 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>   	if (rv)
>   		goto out;
>   
> -#ifdef CONFIG_IPMI_PROC_INTERFACE
>   	rv = add_proc_entries(intf, i);
> -#endif
> -
>    out:
>   	if (rv) {
>   		ipmi_bmc_unregister(intf);
> -#ifdef CONFIG_IPMI_PROC_INTERFACE
> -		if (intf->proc_dir)
> -			remove_proc_entries(intf);
> -#endif
> +		remove_proc_entries(intf);
>   		intf->handlers = NULL;
>   		list_del_rcu(&intf->link);
>   		mutex_unlock(&ipmi_interfaces_mutex);
> @@ -3563,9 +3465,7 @@ int ipmi_unregister_smi(ipmi_smi_t intf)
>   	intf->handlers = NULL;
>   	mutex_unlock(&ipmi_interfaces_mutex);
>   
> -#ifdef CONFIG_IPMI_PROC_INTERFACE
>   	remove_proc_entries(intf);
> -#endif
>   	ipmi_bmc_unregister(intf);
>   
>   	/*
> diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
> index ff870aa91cfe..7acc8cbf8d6f 100644
> --- a/drivers/char/ipmi/ipmi_si_intf.c
> +++ b/drivers/char/ipmi/ipmi_si_intf.c
> @@ -1602,18 +1602,6 @@ static int smi_type_proc_show(struct seq_file *m, void *v)
>   	return 0;
>   }
>   
> -static int smi_type_proc_open(struct inode *inode, struct file *file)
> -{
> -	return single_open(file, smi_type_proc_show, PDE_DATA(inode));
> -}
> -
> -static const struct file_operations smi_type_proc_ops = {
> -	.open		= smi_type_proc_open,
> -	.read		= seq_read,
> -	.llseek		= seq_lseek,
> -	.release	= single_release,
> -};
> -
>   static int smi_si_stats_proc_show(struct seq_file *m, void *v)
>   {
>   	struct smi_info *smi = m->private;
> @@ -1645,18 +1633,6 @@ static int smi_si_stats_proc_show(struct seq_file *m, void *v)
>   	return 0;
>   }
>   
> -static int smi_si_stats_proc_open(struct inode *inode, struct file *file)
> -{
> -	return single_open(file, smi_si_stats_proc_show, PDE_DATA(inode));
> -}
> -
> -static const struct file_operations smi_si_stats_proc_ops = {
> -	.open		= smi_si_stats_proc_open,
> -	.read		= seq_read,
> -	.llseek		= seq_lseek,
> -	.release	= single_release,
> -};
> -
>   static int smi_params_proc_show(struct seq_file *m, void *v)
>   {
>   	struct smi_info *smi = m->private;
> @@ -1674,18 +1650,6 @@ static int smi_params_proc_show(struct seq_file *m, void *v)
>   
>   	return 0;
>   }
> -
> -static int smi_params_proc_open(struct inode *inode, struct file *file)
> -{
> -	return single_open(file, smi_params_proc_show, PDE_DATA(inode));
> -}
> -
> -static const struct file_operations smi_params_proc_ops = {
> -	.open		= smi_params_proc_open,
> -	.read		= seq_read,
> -	.llseek		= seq_lseek,
> -	.release	= single_release,
> -};
>   #endif
>   
>   #define IPMI_SI_ATTR(name) \
> @@ -2182,10 +2146,8 @@ static int try_smi_init(struct smi_info *new_smi)
>   		goto out_err;
>   	}
>   
> -#ifdef CONFIG_IPMI_PROC_INTERFACE
>   	rv = ipmi_smi_add_proc_entry(new_smi->intf, "type",
> -				     &smi_type_proc_ops,
> -				     new_smi);
> +				     smi_type_proc_show, new_smi);
>   	if (rv) {
>   		dev_err(new_smi->io.dev,
>   			"Unable to create proc entry: %d\n", rv);
> @@ -2193,8 +2155,7 @@ static int try_smi_init(struct smi_info *new_smi)
>   	}
>   
>   	rv = ipmi_smi_add_proc_entry(new_smi->intf, "si_stats",
> -				     &smi_si_stats_proc_ops,
> -				     new_smi);
> +				     smi_si_stats_proc_show, new_smi);
>   	if (rv) {
>   		dev_err(new_smi->io.dev,
>   			"Unable to create proc entry: %d\n", rv);
> @@ -2202,14 +2163,12 @@ static int try_smi_init(struct smi_info *new_smi)
>   	}
>   
>   	rv = ipmi_smi_add_proc_entry(new_smi->intf, "params",
> -				     &smi_params_proc_ops,
> -				     new_smi);
> +				     smi_params_proc_show, new_smi);
>   	if (rv) {
>   		dev_err(new_smi->io.dev,
>   			"Unable to create proc entry: %d\n", rv);
>   		goto out_err;
>   	}
> -#endif
>   
>   	/* Don't increment till we know we have succeeded. */
>   	smi_num++;
> diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
> index 35a82f4bfd78..57f6116a17b2 100644
> --- a/drivers/char/ipmi/ipmi_ssif.c
> +++ b/drivers/char/ipmi/ipmi_ssif.c
> @@ -1349,18 +1349,6 @@ static int smi_type_proc_show(struct seq_file *m, void *v)
>   	return 0;
>   }
>   
> -static int smi_type_proc_open(struct inode *inode, struct file *file)
> -{
> -	return single_open(file, smi_type_proc_show, inode->i_private);
> -}
> -
> -static const struct file_operations smi_type_proc_ops = {
> -	.open		= smi_type_proc_open,
> -	.read		= seq_read,
> -	.llseek		= seq_lseek,
> -	.release	= single_release,
> -};
> -
>   static int smi_stats_proc_show(struct seq_file *m, void *v)
>   {
>   	struct ssif_info *ssif_info = m->private;
> @@ -1393,18 +1381,6 @@ static int smi_stats_proc_show(struct seq_file *m, void *v)
>   		   ssif_get_stat(ssif_info, alerts));
>   	return 0;
>   }
> -
> -static int smi_stats_proc_open(struct inode *inode, struct file *file)
> -{
> -	return single_open(file, smi_stats_proc_show, PDE_DATA(inode));
> -}
> -
> -static const struct file_operations smi_stats_proc_ops = {
> -	.open		= smi_stats_proc_open,
> -	.read		= seq_read,
> -	.llseek		= seq_lseek,
> -	.release	= single_release,
> -};
>   #endif
>   
>   static int strcmp_nospace(char *s1, char *s2)
> @@ -1740,23 +1716,19 @@ static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
>   		goto out_remove_attr;
>   	}
>   
> -#ifdef CONFIG_IPMI_PROC_INTERFACE
>   	rv = ipmi_smi_add_proc_entry(ssif_info->intf, "type",
> -				     &smi_type_proc_ops,
> -				     ssif_info);
> +				     smi_type_proc_show, ssif_info);
>   	if (rv) {
>   		pr_err(PFX "Unable to create proc entry: %d\n", rv);
>   		goto out_err_unreg;
>   	}
>   
>   	rv = ipmi_smi_add_proc_entry(ssif_info->intf, "ssif_stats",
> -				     &smi_stats_proc_ops,
> -				     ssif_info);
> +				     smi_stats_proc_show, ssif_info);
>   	if (rv) {
>   		pr_err(PFX "Unable to create proc entry: %d\n", rv);
>   		goto out_err_unreg;
>   	}
> -#endif
>   
>    out:
>   	if (rv) {
> @@ -1775,10 +1747,8 @@ static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
>   	kfree(resp);
>   	return rv;
>   
> -#ifdef CONFIG_IPMI_PROC_INTERFACE
>   out_err_unreg:
>   	ipmi_unregister_smi(ssif_info->intf);
> -#endif
>   
>   out_remove_attr:
>   	device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
> diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h
> index af457b5a689e..78d9fd480fe8 100644
> --- a/include/linux/ipmi_smi.h
> +++ b/include/linux/ipmi_smi.h
> @@ -223,12 +223,10 @@ static inline void ipmi_free_smi_msg(struct ipmi_smi_msg *msg)
>   }
>   
>   #ifdef CONFIG_IPMI_PROC_INTERFACE
> -/* Allow the lower layer to add things to the proc filesystem
> -   directory for this interface.  Note that the entry will
> -   automatically be dstroyed when the interface is destroyed. */
>   int ipmi_smi_add_proc_entry(ipmi_smi_t smi, char *name,
> -			    const struct file_operations *proc_ops,
> -			    void *data);
> +		int (*show)(struct seq_file *, void *), void *data);
> +#else
> +#define ipmi_smi_add_proc_entry(smi, name, show, data)	0
>   #endif
>   
>   #endif /* __LINUX_IPMI_SMI_H */