[PATCH] configsfs buffer: use mutex

Seems copied from sysfs, but I don't see a reason here nor there to use
a semaphore instead of a mutex. Convert.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

diff --git a/fs/configfs/file.c b/fs/configfs/file.c
index 0f4b65e..a3658f9 100644 (file)
--- a/fs/configfs/file.c
+++ b/fs/configfs/file.c
@@ -27,8 +27,8 @@
 #include <linux/fs.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/mutex.h>
 #include <asm/uaccess.h>
-#include <asm/semaphore.h>
 
 #include <linux/configfs.h>
 #include "configfs_internal.h"
@@ -46,7 +46,7 @@ struct configfs_buffer {
        loff_t                  pos;
        char                    * page;
        struct configfs_item_operations * ops;
-       struct semaphore        sem;
+       struct mutex            mutex;
        int                     needs_read_fill;
 };
 
@@ -109,7 +109,7 @@ configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *pp
        struct configfs_buffer * buffer = file->private_data;
        ssize_t retval = 0;
 
-       down(&buffer->sem);
+       mutex_lock(&buffer->mutex);
        if (buffer->needs_read_fill) {
                if ((retval = fill_read_buffer(file->f_path.dentry,buffer)))
                        goto out;
@@ -119,7 +119,7 @@ configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *pp
        retval = simple_read_from_buffer(buf, count, ppos, buffer->page,
                                         buffer->count);
 out:
-       up(&buffer->sem);
+       mutex_unlock(&buffer->mutex);
        return retval;
 }
 
@@ -200,13 +200,13 @@ configfs_write_file(struct file *file, const char __user *buf, size_t count, lof
        struct configfs_buffer * buffer = file->private_data;
        ssize_t len;
 
-       down(&buffer->sem);
+       mutex_lock(&buffer->mutex);
        len = fill_write_buffer(buffer, buf, count);
        if (len > 0)
                len = flush_write_buffer(file->f_path.dentry, buffer, count);
        if (len > 0)
                *ppos += len;
-       up(&buffer->sem);
+       mutex_unlock(&buffer->mutex);
        return len;
 }
 
@@ -260,7 +260,7 @@ static int check_perm(struct inode * inode, struct file * file)
                error = -ENOMEM;
                goto Enomem;
        }
-       init_MUTEX(&buffer->sem);
+       mutex_init(&buffer->mutex);
        buffer->needs_read_fill = 1;
        buffer->ops = ops;
        file->private_data = buffer;
@@ -299,6 +299,7 @@ static int configfs_release(struct inode * inode, struct file * filp)
        if (buffer) {
                if (buffer->page)
                        free_page((unsigned long)buffer->page);
+               mutex_destroy(&buffer->mutex);
                kfree(buffer);
        }
        return 0;