[PATCHv3,1/6] debugfs: add get/set for atomic types
diff mbox series

Message ID 1359409767-30092-2-git-send-email-sjenning@linux.vnet.ibm.com
State New, archived
Headers show
Series
  • zswap: compressed swap caching
Related show

Commit Message

Seth Jennings Jan. 28, 2013, 9:49 p.m. UTC
debugfs currently lack the ability to create attributes
that set/get atomic_t values.

This patch adds support for this through a new
debugfs_create_atomic_t() function.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/debugfs/file.c       |   42 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/debugfs.h |    2 ++
 2 files changed, 44 insertions(+)

Comments

Konrad Rzeszutek Wilk Jan. 29, 2013, 8:35 p.m. UTC | #1
On Mon, Jan 28, 2013 at 03:49:22PM -0600, Seth Jennings wrote:
> debugfs currently lack the ability to create attributes
> that set/get atomic_t values.
> 
> This patch adds support for this through a new
> debugfs_create_atomic_t() function.
> 
> Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
>  fs/debugfs/file.c       |   42 ++++++++++++++++++++++++++++++++++++++++++
>  include/linux/debugfs.h |    2 ++
>  2 files changed, 44 insertions(+)
> 
> diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
> index c5ca6ae..fa26d5b 100644
> --- a/fs/debugfs/file.c
> +++ b/fs/debugfs/file.c
> @@ -21,6 +21,7 @@
>  #include <linux/debugfs.h>
>  #include <linux/io.h>
>  #include <linux/slab.h>
> +#include <linux/atomic.h>
>  
>  static ssize_t default_read_file(struct file *file, char __user *buf,
>  				 size_t count, loff_t *ppos)
> @@ -403,6 +404,47 @@ struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
>  }
>  EXPORT_SYMBOL_GPL(debugfs_create_size_t);
>  
> +static int debugfs_atomic_t_set(void *data, u64 val)

Should the 'data' be 'atomic_t *' just to make sure nobody messes this
up? Or would that bring too much header changes?

> +{
> +	atomic_set((atomic_t *)data, val);
> +	return 0;
> +}
> +static int debugfs_atomic_t_get(void *data, u64 *val)
> +{
> +	*val = atomic_read((atomic_t *)data);
> +	return 0;
> +}
> +DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
> +			debugfs_atomic_t_set, "%llu\n");
> +DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%llu\n");
> +DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%llu\n");
> +
> +/**
> + * debugfs_create_atomic_t - create a debugfs file that is used to read and
> + * write an atomic_t value
> + * @name: a pointer to a string containing the name of the file to create.
> + * @mode: the permission that the file should have
> + * @parent: a pointer to the parent dentry for this file.  This should be a
> + *          directory dentry if set.  If this parameter is %NULL, then the
> + *          file will be created in the root of the debugfs filesystem.
> + * @value: a pointer to the variable that the file should read to and write
> + *         from.
> + */
> +struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
> +				 struct dentry *parent, atomic_t *value)
> +{
> +	/* if there are no write bits set, make read only */
> +	if (!(mode & S_IWUGO))
> +		return debugfs_create_file(name, mode, parent, value,
> +					&fops_atomic_t_ro);
> +	/* if there are no read bits set, make write only */
> +	if (!(mode & S_IRUGO))
> +		return debugfs_create_file(name, mode, parent, value,
> +					&fops_atomic_t_wo);
> +
> +	return debugfs_create_file(name, mode, parent, value, &fops_atomic_t);
> +}
> +EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
>  
>  static ssize_t read_file_bool(struct file *file, char __user *user_buf,
>  			      size_t count, loff_t *ppos)
> diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
> index 66c434f..51fea70 100644
> --- a/include/linux/debugfs.h
> +++ b/include/linux/debugfs.h
> @@ -79,6 +79,8 @@ struct dentry *debugfs_create_x64(const char *name, umode_t mode,
>  				  struct dentry *parent, u64 *value);
>  struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
>  				     struct dentry *parent, size_t *value);
> +struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
> +				     struct dentry *parent, atomic_t *value);
>  struct dentry *debugfs_create_bool(const char *name, umode_t mode,
>  				  struct dentry *parent, u32 *value);
>  
> -- 
> 1.7.9.5
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/
Seth Jennings Jan. 29, 2013, 8:49 p.m. UTC | #2
On 01/29/2013 02:35 PM, Konrad Rzeszutek Wilk wrote:
> On Mon, Jan 28, 2013 at 03:49:22PM -0600, Seth Jennings wrote:
>> debugfs currently lack the ability to create attributes
>> that set/get atomic_t values.
>>
>> This patch adds support for this through a new
>> debugfs_create_atomic_t() function.
>>
>> Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
>> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> ---
>>  fs/debugfs/file.c       |   42 ++++++++++++++++++++++++++++++++++++++++++
>>  include/linux/debugfs.h |    2 ++
>>  2 files changed, 44 insertions(+)
>>
>> diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
>> index c5ca6ae..fa26d5b 100644
>> --- a/fs/debugfs/file.c
>> +++ b/fs/debugfs/file.c
>> @@ -21,6 +21,7 @@
>>  #include <linux/debugfs.h>
>>  #include <linux/io.h>
>>  #include <linux/slab.h>
>> +#include <linux/atomic.h>
>>  
>>  static ssize_t default_read_file(struct file *file, char __user *buf,
>>  				 size_t count, loff_t *ppos)
>> @@ -403,6 +404,47 @@ struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
>>  }
>>  EXPORT_SYMBOL_GPL(debugfs_create_size_t);
>>  
>> +static int debugfs_atomic_t_set(void *data, u64 val)
> 
> Should the 'data' be 'atomic_t *' just to make sure nobody messes this
> up? Or would that bring too much header changes?

DEFINE_SIMPLE_ATTRIBUTE() uses simple_attr_open() whose signature
requires the argument be a void *.  So we can't change it (easily).

Seth

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Patch
diff mbox series

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index c5ca6ae..fa26d5b 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -21,6 +21,7 @@ 
 #include <linux/debugfs.h>
 #include <linux/io.h>
 #include <linux/slab.h>
+#include <linux/atomic.h>
 
 static ssize_t default_read_file(struct file *file, char __user *buf,
 				 size_t count, loff_t *ppos)
@@ -403,6 +404,47 @@  struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
 }
 EXPORT_SYMBOL_GPL(debugfs_create_size_t);
 
+static int debugfs_atomic_t_set(void *data, u64 val)
+{
+	atomic_set((atomic_t *)data, val);
+	return 0;
+}
+static int debugfs_atomic_t_get(void *data, u64 *val)
+{
+	*val = atomic_read((atomic_t *)data);
+	return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
+			debugfs_atomic_t_set, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%llu\n");
+
+/**
+ * debugfs_create_atomic_t - create a debugfs file that is used to read and
+ * write an atomic_t value
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have
+ * @parent: a pointer to the parent dentry for this file.  This should be a
+ *          directory dentry if set.  If this parameter is %NULL, then the
+ *          file will be created in the root of the debugfs filesystem.
+ * @value: a pointer to the variable that the file should read to and write
+ *         from.
+ */
+struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
+				 struct dentry *parent, atomic_t *value)
+{
+	/* if there are no write bits set, make read only */
+	if (!(mode & S_IWUGO))
+		return debugfs_create_file(name, mode, parent, value,
+					&fops_atomic_t_ro);
+	/* if there are no read bits set, make write only */
+	if (!(mode & S_IRUGO))
+		return debugfs_create_file(name, mode, parent, value,
+					&fops_atomic_t_wo);
+
+	return debugfs_create_file(name, mode, parent, value, &fops_atomic_t);
+}
+EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
 
 static ssize_t read_file_bool(struct file *file, char __user *user_buf,
 			      size_t count, loff_t *ppos)
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index 66c434f..51fea70 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -79,6 +79,8 @@  struct dentry *debugfs_create_x64(const char *name, umode_t mode,
 				  struct dentry *parent, u64 *value);
 struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
 				     struct dentry *parent, size_t *value);
+struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
+				     struct dentry *parent, atomic_t *value);
 struct dentry *debugfs_create_bool(const char *name, umode_t mode,
 				  struct dentry *parent, u32 *value);