1 files changed, 45 insertions, 7 deletions

diff --git a/fs/seq_file.c b/fs/seq_file.c
index 0ac22af7afe5..bbb19be260ce 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -177,21 +177,23 @@ EXPORT_SYMBOL(seq_read);
 
 static int traverse(struct seq_file *m, loff_t offset)
 {
-        loff_t pos = 0;
+        loff_t pos = 0, index;
         int error = 0;
         void *p;
 
         m->version = 0;
-        m->index = 0;
+        index = 0;
         m->count = m->from = 0;
-        if (!offset)
+        if (!offset) {
+                m->index = index;
                 return 0;
+        }
         if (!m->buf) {
                 m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL);
                 if (!m->buf)
                         return -ENOMEM;
         }
-        p = m->op->start(m, &m->index);
+        p = m->op->start(m, &index);
         while (p) {
                 error = PTR_ERR(p);
                 if (IS_ERR(p))
@@ -204,15 +206,17 @@ static int traverse(struct seq_file *m, loff_t offset)
                 if (pos + m->count > offset) {
                         m->from = offset - pos;
                         m->count -= m->from;
+                        m->index = index;
                         break;
                 }
                 pos += m->count;
                 m->count = 0;
                 if (pos == offset) {
-                        m->index++;
+                        index++;
+                        m->index = index;
                         break;
                 }
-                p = m->op->next(m, p, &m->index);
+                p = m->op->next(m, p, &index);
         }
         m->op->stop(m, p);
         return error;
@@ -260,8 +264,8 @@ loff_t seq_lseek(struct file *file, loff_t offset, int origin)
                                 }
                         }
         }
-        mutex_unlock(&m->lock);
         file->f_version = m->version;
+        mutex_unlock(&m->lock);
         return retval;
 }
 EXPORT_SYMBOL(seq_lseek);
@@ -447,3 +451,37 @@ int seq_puts(struct seq_file *m, const char *s)
         return -1;
 }
 EXPORT_SYMBOL(seq_puts);
+
+struct list_head *seq_list_start(struct list_head *head, loff_t pos)
+{
+        struct list_head *lh;
+
+        list_for_each(lh, head)
+                if (pos-- == 0)
+                        return lh;
+
+        return NULL;
+}
+
+EXPORT_SYMBOL(seq_list_start);
+
+struct list_head *seq_list_start_head(struct list_head *head, loff_t pos)
+{
+        if (!pos)
+                return head;
+
+        return seq_list_start(head, pos - 1);
+}
+
+EXPORT_SYMBOL(seq_list_start_head);
+
+struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos)
+{
+        struct list_head *lh;
+
+        lh = ((struct list_head *)v)->next;
+        ++*ppos;
+        return lh == head ? NULL : lh;
+}
+
+EXPORT_SYMBOL(seq_list_next);