*/
int seq_open(struct file *file, 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
/**
* seq_read - ->read() method for sequential files.
- * @file, @buf, @size, @ppos: see file_operations method
+ * @file: the file to read from
+ * @buf: the buffer to read to
+ * @size: the maximum number of bytes to read
+ * @ppos: the current position in the file
*
* Ready-made ->f_op->read()
*/
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;
/**
* seq_lseek - ->llseek() method for sequential files.
- * @file, @offset, @origin: see file_operations method
+ * @file: the file in question
+ * @offset: new position
+ * @origin: 0 for absolute, 1 for relative position
*
* Ready-made ->f_op->llseek()
*/
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;
}