[PATCH] Rewrite proc seq operations via seq_list_xxx ones

Pavel Emelyanov
2007-10-10T11:14:29Z

Some time ago I posted a set of patches that consolidated
the seq files, walking the list_head-s. This set was merged
in the mm tree. /proc/diskstats and /proc/partitions files
were included in this set, but a bit later this part was
dropped because of conflicts with some other changes.

Here's the fixed version against the latest git block repo.

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

---

diff --git a/block/genhd.c b/block/genhd.c
index 3af1e7a..27f7061 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -264,39 +264,34 @@ void __init printk_all_partitions(void)

#ifdef CONFIG_PROC_FS
/* iterator */
-static void *part_start(struct seq_file *part, loff_t *pos)
+static void *disk_start(struct seq_file *part, loff_t *pos)
{
- struct list_head *p;
- loff_t l = *pos;
-
mutex_lock(&block_subsys_lock);
- list_for_each(p, &block_subsys.list)
- if (!l--)
- return list_entry(p, struct gendisk, kobj.entry);
- return NULL;
+ return seq_list_start_head(&block_subsys.list, *pos);
}

-static void *part_next(struct seq_file *part, void *v, loff_t *pos)
+static void *disk_next(struct seq_file *part, void *v, loff_t *pos)
{
- struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
- ++*pos;
- return p==&block_subsys.list ? NULL :
- list_entry(p, struct gendisk, kobj.entry);
+ return seq_list_next(v, &block_subsys.list, pos);
}

-static void part_stop(struct seq_file *part, void *v)
+static void disk_stop(struct seq_file *part, void *v)
{
mutex_unlock(&block_subsys_lock);
}

static int show_partition(struct seq_file *part, void *v)
{
- struct gendisk *sgp = v;
+ struct gendisk *sgp;
int n;
char buf[BDEVNAME_SIZE];

- if (&sgp->kobj.entry == block_subsys.list.next)
+ if (v == &block_subsys.list) {
seq_puts(part, "major minor #blocks name\n\n");
+ return 0;
+ }
+
+ sgp = list_entry(v, struct gendisk, kobj.entry);

/* Don't show non-partitionable removeable devices or empty devices */
if (!get_capacity(sgp) ||
@@ -325,9 +320,9 @@ static int show_partition(struct seq_fil
}

struct seq_operations partitions_op = {
- .start =part_start,
- .next = part_next,
- .stop = part_stop,
+ .start =disk_start,
+ .next = disk_next,
+ .stop = disk_stop,
.show = show_partition
};
#endif
@@ -616,44 +611,22 @@ decl_subsys(block, &ktype_block, &block_
*/

/* iterator */
-static void *diskstats_start(struct seq_file *part, loff_t *pos)
-{
- loff_t k = *pos;
- struct list_head *p;
-
- mutex_lock(&block_subsys_lock);
- list_for_each(p, &block_subsys.list)
- if (!k--)
- return list_entry(p, struct gendisk, kobj.entry);
- return NULL;
-}
-
-static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
-{
- struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
- ++*pos;
- return p==&block_subsys.list ? NULL :
- list_entry(p, struct gendisk, kobj.entry);
-}
-
-static void diskstats_stop(struct seq_file *part, void *v)
-{
- mutex_unlock(&block_subsys_lock);
-}
-
static int diskstats_show(struct seq_file *s, void *v)
{
- struct gendisk *gp = v;
+ struct gendisk *gp;
char buf[BDEVNAME_SIZE];
int n = 0;

+ if (v == &block_subsys.list)
/*
- if (&sgp->kobj.entry == block_subsys.kset.list.next)
seq_puts(s, "major minor name"
" rio rmerge rsect ruse wio wmerge "
"wsect wuse running use aveq"
"\n\n");
*/
+ return 0;
+
+ gp = list_entry(v, struct gendisk, kobj.entry);

preempt_disable();
disk_round_stats(gp);
@@ -686,9 +659,9 @@ static int diskstats_show(struct seq_fil
}

struct seq_operations diskstats_op = {
- .start = diskstats_start,
- .next = diskstats_next,
- .stop = diskstats_stop,
+ .start = disk_start,
+ .next = disk_next,
+ .stop = disk_stop,
.show = diskstats_show
};