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-rw-r--r--fs/configfs/file.c28
1 files changed, 18 insertions, 10 deletions
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;