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Diffstat (limited to 'fs/seq_file.c')
-rw-r--r--fs/seq_file.c20
1 files changed, 12 insertions, 8 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c
index d8a0545ad7ea..ce9e39fd5daf 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -48,18 +48,21 @@ static void *seq_buf_alloc(unsigned long size)
* 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.
* Returning SEQ_SKIP means "discard this element and move on".
+ * Note: seq_open() will allocate a struct seq_file and store its
+ * pointer in @file->private_data. This pointer should not be modified.
*/
int seq_open(struct file *file, const struct seq_operations *op)
{
- struct seq_file *p = file->private_data;
+ struct seq_file *p;
+
+ WARN_ON(file->private_data);
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+
+ file->private_data = p;
- if (!p) {
- p = kmalloc(sizeof(*p), GFP_KERNEL);
- if (!p)
- return -ENOMEM;
- file->private_data = p;
- }
- memset(p, 0, sizeof(*p));
mutex_init(&p->lock);
p->op = op;
#ifdef CONFIG_USER_NS
@@ -552,6 +555,7 @@ int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc)
return res;
}
+EXPORT_SYMBOL(seq_dentry);
static void *single_start(struct seq_file *p, loff_t *pos)
{