[PATCH v2] procfs: fix numbering in /proc/locks

[Jerome Marchand <jmarchan@redhat.com>]

The lock number in /proc/locks (first field) is implemented by a counter
(private field of struct seq_file) which is incremented at each call of
locks_show() and reset to 1 in locks_start() whatever the offset is. It
should be reset according to the actual position in the list.

Moreover, locks_show() can be called twice to print a single line thus
skipping a number. The counter should be incremented in locks_next().

Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
---
 locks.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index ab24d49..49d7343 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -2166,19 +2166,19 @@ static int locks_show(struct seq_file *f, void *v)
 	list_for_each_entry(bfl, &fl->fl_block, fl_block)
 		lock_get_status(f, bfl, (long)f->private, " ->");
 
-	f->private++;
 	return 0;
 }
 
 static void *locks_start(struct seq_file *f, loff_t *pos)
 {
 	lock_kernel();
-	f->private = (void *)1;
+	f->private = (void *) (*pos + 1);
 	return seq_list_start(&file_lock_list, *pos);
 }
 
 static void *locks_next(struct seq_file *f, void *v, loff_t *pos)
 {
+	f->private++;
 	return seq_list_next(v, &file_lock_list, pos);
 }