[PATCH] Sort module list - use ppos instead of m->private

Mathieu Desnoyers
2007-08-24T15:39:47Z

Sort modules list - use ppos instead of m->private

When reading the data by small chunks (i.e. byte by byte), the index (ppos) is
incremented by seq_read() directly and no "next" callback is called when going
to the next module.

Therefore, use ppos instead of m->private to deal with the fact that this index
is incremented directly to pass to the next module in seq_read() after the
buffer has been emptied.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
---
fs/seq_file.c | 17 +++++++++--------
include/linux/seq_file.h | 4 ++--
kernel/module.c | 6 ++----
3 files changed, 13 insertions(+), 14 deletions(-)

Index: linux-2.6-lttng/kernel/module.c
===================================================================
--- linux-2.6-lttng.orig/kernel/module.c 2007-08-24 11:34:36.000000000 -0400
+++ linux-2.6-lttng/kernel/module.c 2007-08-24 11:35:40.000000000 -0400
@@ -2418,14 +2418,12 @@ unsigned long module_kallsyms_lookup_nam
static void *m_start(struct seq_file *m, loff_t *pos)
{
mutex_lock(&module_mutex);
- if (!*pos)
- m->private = NULL;
- return seq_sorted_list_start(&modules, m->private);
+ return seq_sorted_list_start(&modules, (void*)(long)pos);
}

static void *m_next(struct seq_file *m, void *p, loff_t *pos)
{
- return seq_sorted_list_next(p, &modules, &m->private);
+ return seq_sorted_list_next(p, &modules, (void**)pos);
}

static void m_stop(struct seq_file *m, void *p)
Index: linux-2.6-lttng/include/linux/seq_file.h
===================================================================
--- linux-2.6-lttng.orig/include/linux/seq_file.h 2007-08-24 11:34:01.000000000 -0400
+++ linux-2.6-lttng/include/linux/seq_file.h 2007-08-24 11:34:59.000000000 -0400
@@ -73,9 +73,9 @@ extern struct list_head *seq_list_next(v
* seq_sorted_list_start_head().
*/
extern struct list_head *seq_sorted_list_start(struct list_head *head,
- void *pos);
+ void **ppos);
extern struct list_head *seq_sorted_list_start_head(struct list_head *head,
- void *pos);
+ void **ppos);
/*
* next must be called with an existing p node
*/
Index: linux-2.6-lttng/fs/seq_file.c
===================================================================
--- linux-2.6-lttng.orig/fs/seq_file.c 2007-08-24 11:34:01.000000000 -0400
+++ linux-2.6-lttng/fs/seq_file.c 2007-08-24 11:34:59.000000000 -0400
@@ -501,27 +501,28 @@ struct list_head *seq_list_next(void *v,

EXPORT_SYMBOL(seq_list_next);

-struct list_head *seq_sorted_list_start(struct list_head *head, void *pos)
+struct list_head *seq_sorted_list_start(struct list_head *head, void **ppos)
{
struct list_head *lh;

list_for_each(lh, head)
- if ((void*)lh >= pos)
- return lh;
+ if ((void*)lh >= *ppos)
+ return *ppos = lh;
return NULL;
}

EXPORT_SYMBOL(seq_sorted_list_start);

-struct list_head *seq_sorted_list_start_head(struct list_head *head, void *pos)
+struct list_head *seq_sorted_list_start_head(struct list_head *head,
+ void **ppos)
{
struct list_head *lh;

- if (!pos)
- return head;
+ if (!ppos)
+ return *ppos = head;
list_for_each(lh, head)
- if ((void*)lh >= pos)
- return lh->prev;
+ if ((void*)lh >= *ppos)
+ return *ppos = lh->prev;
return NULL;