Re: [PATCH 7/15] Make ISDN CAPI use seq_list_xxx helpers

Re: [PATCH 7/15] Make ISDN CAPI use seq_list_xxx helpers

[Karsten Keil]

The similar code exists here and is called capi_driver_get_idx().
Use generic helpers now and remember to convert list_head to
struct capi_driver in .show callback.

Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Pavel Emelianov <xemul@openvz.org>

---

diff --git a/drivers/isdn/capi/kcapi_proc.c b/drivers/isdn/capi/kcapi_proc.c
index 31f4fd8..845a797 100644
--- a/drivers/isdn/capi/kcapi_proc.c
+++ b/drivers/isdn/capi/kcapi_proc.c
@@ -243,36 +243,15 @@ create_seq_entry(char *name, mode_t mode
 
 // ---------------------------------------------------------------------------
 
-
-static __inline__ struct capi_driver *capi_driver_get_idx(loff_t pos)
-{
-	struct capi_driver *drv = NULL;
-	struct list_head *l;
-	loff_t i;
-
-	i = 0;
-	list_for_each(l, &capi_drivers) {
-		drv = list_entry(l, struct capi_driver, list);
-		if (i++ == pos)
-			return drv;
-	}
-	return NULL;
-}
-
 static void *capi_driver_start(struct seq_file *seq, loff_t *pos)
 {
-	struct capi_driver *drv;
 	read_lock(&capi_drivers_list_lock);
-	drv = capi_driver_get_idx(*pos);
-	return drv;
+	return seq_list_start(&capi_drivers, *pos);
 }
 
 static void *capi_driver_next(struct seq_file *seq, void *v, loff_t *pos)
 {
-	struct capi_driver *drv = (struct capi_driver *)v;
-	++*pos;
-	if (drv->list.next == &capi_drivers) return NULL;
-	return list_entry(drv->list.next, struct capi_driver, list);
+	return seq_list_next(v, &capi_drivers, pos);
 }
 
 static void capi_driver_stop(struct seq_file *seq, void *v)
@@ -282,7 +261,8 @@ static void capi_driver_stop(struct seq_
 
 static int capi_driver_show(struct seq_file *seq, void *v)
 {
-	struct capi_driver *drv = (struct capi_driver *)v;
+	struct capi_driver *drv = list_entry(v, struct capi_driver, list);
+
 	seq_printf(seq, "%-32s %s\n", drv->name, drv->revision);
 	return 0;
 }

-- 
Karsten Keil
SuSE Labs
ISDN and VOIP development
SUSE LINUX Products GmbH, Maxfeldstr.5 90409 Nuernberg, GF: Markus Rex, HRB 16746 (AG Nuernberg)

[PATCH 0/15] Make common helpers for seq_files that work with list_head-s (v2)

[Pavel Emelianov]

Many places in kernel use seq_file API to iterate over a regular
list_head. The code for such iteration is identical in all the
places, so it's worth introducing a common helpers.

This makes code about 300 lines smaller:

 block/genhd.c                                         |   40 +++-----
 crypto/proc.c                                         |   17 ---
 drivers/char/misc.c                                   |   18 ----
 drivers/input/input.c                                 |   29 ------
 drivers/isdn/capi/kcapi_proc.c                        |   28 ------
 fs/afs/proc.c                                         |   81 ++----------------
 fs/namespace.c                                        |   14 ---
 fs/nfs/client.c                                       |   54 +-----------
 fs/proc/proc_tty.c                                    |   15 ---
 fs/seq_file.c                                         |   34 +++++++
 include/linux/seq_file.h                              |   11 ++
 kernel/module.c                                       |   17 ---
 mm/slab.c                                             |   28 +-----
 net/atm/br2684.c                                      |   22 ----
 net/core/sock.c                                       |   39 --------
 net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c |   27 ------
 net/netfilter/nf_conntrack_expect.c                   |   27 ------
 net/rxrpc/ar-proc.c                                   |   48 +---------
 18 files changed, 126 insertions(+), 423 deletions(-)

The first version of this patch made the helper functions static inline
in the seq_file.h header. This patch moves them to the fs/seq_file.c as
Andrew proposed. The vmlinux .text section sizes are as follows:

2.6.22-rc1-mm1:              0x001794d5
with the previous version:   0x00179505
with this patch:             0x00179135

The config file used was make allnoconfig with the "y" inclusion of all
the possible options to make the files modified by the patch compile plus
drivers I have on the test node.

[PATCH 7/15] Make ISDN CAPI use seq_list_xxx helpers

[Pavel Emelianov]

The similar code exists here and is called capi_driver_get_idx().
Use generic helpers now and remember to convert list_head to
struct capi_driver in .show callback.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>

---

diff --git a/drivers/isdn/capi/kcapi_proc.c b/drivers/isdn/capi/kcapi_proc.c
index 31f4fd8..845a797 100644
--- a/drivers/isdn/capi/kcapi_proc.c
+++ b/drivers/isdn/capi/kcapi_proc.c
@@ -243,36 +243,15 @@ create_seq_entry(char *name, mode_t mode
 
 // ---------------------------------------------------------------------------
 
-
-static __inline__ struct capi_driver *capi_driver_get_idx(loff_t pos)
-{
-	struct capi_driver *drv = NULL;
-	struct list_head *l;
-	loff_t i;
-
-	i = 0;
-	list_for_each(l, &capi_drivers) {
-		drv = list_entry(l, struct capi_driver, list);
-		if (i++ == pos)
-			return drv;
-	}
-	return NULL;
-}
-
 static void *capi_driver_start(struct seq_file *seq, loff_t *pos)
 {
-	struct capi_driver *drv;
 	read_lock(&capi_drivers_list_lock);
-	drv = capi_driver_get_idx(*pos);
-	return drv;
+	return seq_list_start(&capi_drivers, *pos);
 }
 
 static void *capi_driver_next(struct seq_file *seq, void *v, loff_t *pos)
 {
-	struct capi_driver *drv = (struct capi_driver *)v;
-	++*pos;
-	if (drv->list.next == &capi_drivers) return NULL;
-	return list_entry(drv->list.next, struct capi_driver, list);
+	return seq_list_next(v, &capi_drivers, pos);
 }
 
 static void capi_driver_stop(struct seq_file *seq, void *v)
@@ -282,7 +261,8 @@ static void capi_driver_stop(struct seq_
 
 static int capi_driver_show(struct seq_file *seq, void *v)
 {
-	struct capi_driver *drv = (struct capi_driver *)v;
+	struct capi_driver *drv = list_entry(v, struct capi_driver, list);
+
 	seq_printf(seq, "%-32s %s\n", drv->name, drv->revision);
 	return 0;
 }