* ERR_PTR(error). In the end of sequence they return %NULL. ->show()
* returns 0 in case of success and negative number in case of error.
*/
-int seq_open(struct file *file, struct seq_operations *op)
+int seq_open(struct file *file, const struct seq_operations *op)
{
- struct seq_file *p = kmalloc(sizeof(*p), GFP_KERNEL);
- if (!p)
- return -ENOMEM;
+ struct seq_file *p = file->private_data;
+
+ if (!p) {
+ p = kmalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+ file->private_data = p;
+ }
memset(p, 0, sizeof(*p));
- sema_init(&p->sem, 1);
+ mutex_init(&p->lock);
p->op = op;
- file->private_data = p;
/*
* Wrappers around seq_open(e.g. swaps_open) need to be
void *p;
int err = 0;
- down(&m->sem);
+ mutex_lock(&m->lock);
/*
* seq_file->op->..m_start/m_stop/m_next may do special actions
* or optimisations based on the file->f_version, so we want to
else
*ppos += copied;
file->f_version = m->version;
- up(&m->sem);
+ mutex_unlock(&m->lock);
return copied;
Enomem:
err = -ENOMEM;
struct seq_file *m = (struct seq_file *)file->private_data;
long long retval = -EINVAL;
- down(&m->sem);
+ mutex_lock(&m->lock);
m->version = file->f_version;
switch (origin) {
case 1:
}
}
}
- up(&m->sem);
+ mutex_unlock(&m->lock);
file->f_version = m->version;
return retval;
}
/**
* seq_release - free the structures associated with sequential file.
* @file: file in question
- * @inode: file->f_dentry->d_inode
+ * @inode: file->f_path.dentry->d_inode
*
* Frees the structures associated with sequential file; can be used
* as ->f_op->release() if you don't have private data to destroy.
int single_release(struct inode *inode, struct file *file)
{
- struct seq_operations *op = ((struct seq_file *)file->private_data)->op;
+ const struct seq_operations *op = ((struct seq_file *)file->private_data)->op;
int res = seq_release(inode, file);
kfree(op);
return res;