X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=fs%2Fconfigfs%2Ffile.c;h=a3658f9a082c691cc11c22de9177e253edbc5cf9;hb=6d748924b753d63a57dad130fdf11f64c27ff54b;hp=3527c7c6def898cb39d1118738b8d7a89475edc7;hpb=2c4f365ad2361c93c097e958b2b0a7a112750228;p=karo-tx-linux.git

diff --git a/fs/configfs/file.c b/fs/configfs/file.c
index 3527c7c6def8..a3658f9a082c 100644
--- a/fs/configfs/file.c
+++ b/fs/configfs/file.c
@@ -27,19 +27,26 @@
 #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"
 
+/*
+ * A simple attribute can only be 4096 characters.  Why 4k?  Because the
+ * original code limited it to PAGE_SIZE.  That's a bad idea, though,
+ * because an attribute of 16k on ia64 won't work on x86.  So we limit to
+ * 4k, our minimum common page size.
+ */
+#define SIMPLE_ATTR_SIZE 4096
 
 struct configfs_buffer {
 	size_t			count;
 	loff_t			pos;
 	char			* page;
 	struct configfs_item_operations	* ops;
-	struct semaphore	sem;
+	struct mutex		mutex;
 	int			needs_read_fill;
 };
 
@@ -69,7 +76,7 @@ static int fill_read_buffer(struct dentry * dentry, struct configfs_buffer * buf
 
 	count = ops->show_attribute(item,attr,buffer->page);
 	buffer->needs_read_fill = 0;
-	BUG_ON(count > (ssize_t)PAGE_SIZE);
+	BUG_ON(count > (ssize_t)SIMPLE_ATTR_SIZE);
 	if (count >= 0)
 		buffer->count = count;
 	else
@@ -102,7 +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;
@@ -112,7 +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;
 }
 
@@ -137,8 +144,8 @@ fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size
 	if (!buffer->page)
 		return -ENOMEM;
 
-	if (count >= PAGE_SIZE)
-		count = PAGE_SIZE - 1;
+	if (count >= SIMPLE_ATTR_SIZE)
+		count = SIMPLE_ATTR_SIZE - 1;
 	error = copy_from_user(buffer->page,buf,count);
 	buffer->needs_read_fill = 1;
 	/* if buf is assumed to contain a string, terminate it by \0,
@@ -193,13 +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;
 }
 
@@ -253,7 +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;
@@ -292,6 +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;