[PATCH 07/23] kobj_map semaphore to mutex conversion

From: Greg Kroah-Hartman
Date: Mon Mar 20 2006 - 17:01:19 EST

Convert the kobj_map code to use a mutex instead of a semaphore. It
converts the single two users as well, genhd.c and char_dev.c.

Signed-off-by: Jes Sorensen <jes@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---

block/genhd.c | 31 ++++++++++++++++---------------
drivers/base/map.c | 21 +++++++++++----------
fs/char_dev.c | 17 +++++++++--------
include/linux/kobj_map.h | 4 ++--
4 files changed, 38 insertions(+), 35 deletions(-)

58383af629efb07e5a0694e445eda0c65b16e1de
diff --git a/block/genhd.c b/block/genhd.c
index db57546..64510fd 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -15,12 +15,13 @@
#include <linux/kmod.h>
#include <linux/kobj_map.h>
#include <linux/buffer_head.h>
+#include <linux/mutex.h>

#define MAX_PROBE_HASH 255 /* random */

static struct subsystem block_subsys;

-static DECLARE_MUTEX(block_subsys_sem);
+static DEFINE_MUTEX(block_subsys_lock);

/*
* Can be deleted altogether. Later.
@@ -46,7 +47,7 @@ struct blkdev_info {
/*
* iterate over a list of blkdev_info structures. allows
* the major_names array to be iterated over from outside this file
- * must be called with the block_subsys_sem held
+ * must be called with the block_subsys_lock held
*/
void *get_next_blkdev(void *dev)
{
@@ -85,20 +86,20 @@ out:

void *acquire_blkdev_list(void)
{
- down(&block_subsys_sem);
+ mutex_lock(&block_subsys_lock);
return get_next_blkdev(NULL);
}

void release_blkdev_list(void *dev)
{
- up(&block_subsys_sem);
+ mutex_unlock(&block_subsys_lock);
kfree(dev);
}


/*
* Count the number of records in the blkdev_list.
- * must be called with the block_subsys_sem held
+ * must be called with the block_subsys_lock held
*/
int count_blkdev_list(void)
{
@@ -118,7 +119,7 @@ int count_blkdev_list(void)
/*
* extract the major and name values from a blkdev_info struct
* passed in as a void to *dev. Must be called with
- * block_subsys_sem held
+ * block_subsys_lock held
*/
int get_blkdev_info(void *dev, int *major, char **name)
{
@@ -138,7 +139,7 @@ int register_blkdev(unsigned int major,
struct blk_major_name **n, *p;
int index, ret = 0;

- down(&block_subsys_sem);
+ mutex_lock(&block_subsys_lock);

/* temporary */
if (major == 0) {
@@ -183,7 +184,7 @@ int register_blkdev(unsigned int major,
kfree(p);
}
out:
- up(&block_subsys_sem);
+ mutex_unlock(&block_subsys_lock);
return ret;
}

@@ -197,7 +198,7 @@ int unregister_blkdev(unsigned int major
int index = major_to_index(major);
int ret = 0;

- down(&block_subsys_sem);
+ mutex_lock(&block_subsys_lock);
for (n = &major_names[index]; *n; n = &(*n)->next)
if ((*n)->major == major)
break;
@@ -207,7 +208,7 @@ int unregister_blkdev(unsigned int major
p = *n;
*n = p->next;
}
- up(&block_subsys_sem);
+ mutex_unlock(&block_subsys_lock);
kfree(p);

return ret;
@@ -301,7 +302,7 @@ static void *part_start(struct seq_file
struct list_head *p;
loff_t l = *pos;

- down(&block_subsys_sem);
+ mutex_lock(&block_subsys_lock);
list_for_each(p, &block_subsys.kset.list)
if (!l--)
return list_entry(p, struct gendisk, kobj.entry);
@@ -318,7 +319,7 @@ static void *part_next(struct seq_file *

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

static int show_partition(struct seq_file *part, void *v)
@@ -377,7 +378,7 @@ static struct kobject *base_probe(dev_t

static int __init genhd_device_init(void)
{
- bdev_map = kobj_map_init(base_probe, &block_subsys_sem);
+ bdev_map = kobj_map_init(base_probe, &block_subsys_lock);
blk_dev_init();
subsystem_register(&block_subsys);
return 0;
@@ -611,7 +612,7 @@ static void *diskstats_start(struct seq_
loff_t k = *pos;
struct list_head *p;

- down(&block_subsys_sem);
+ mutex_lock(&block_subsys_lock);
list_for_each(p, &block_subsys.kset.list)
if (!k--)
return list_entry(p, struct gendisk, kobj.entry);
@@ -628,7 +629,7 @@ static void *diskstats_next(struct seq_f

static void diskstats_stop(struct seq_file *part, void *v)
{
- up(&block_subsys_sem);
+ mutex_unlock(&block_subsys_lock);
}

static int diskstats_show(struct seq_file *s, void *v)
diff --git a/drivers/base/map.c b/drivers/base/map.c
index b449dae..e87017f 100644
--- a/drivers/base/map.c
+++ b/drivers/base/map.c
@@ -11,6 +11,7 @@

#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/mutex.h>
#include <linux/kdev_t.h>
#include <linux/kobject.h>
#include <linux/kobj_map.h>
@@ -25,7 +26,7 @@ struct kobj_map {
int (*lock)(dev_t, void *);
void *data;
} *probes[255];
- struct semaphore *sem;
+ struct mutex *lock;
};

int kobj_map(struct kobj_map *domain, dev_t dev, unsigned long range,
@@ -53,7 +54,7 @@ int kobj_map(struct kobj_map *domain, de
p->range = range;
p->data = data;
}
- down(domain->sem);
+ mutex_lock(domain->lock);
for (i = 0, p -= n; i < n; i++, p++, index++) {
struct probe **s = &domain->probes[index % 255];
while (*s && (*s)->range < range)
@@ -61,7 +62,7 @@ int kobj_map(struct kobj_map *domain, de
p->next = *s;
*s = p;
}
- up(domain->sem);
+ mutex_unlock(domain->lock);
return 0;
}

@@ -75,7 +76,7 @@ void kobj_unmap(struct kobj_map *domain,
if (n > 255)
n = 255;

- down(domain->sem);
+ mutex_lock(domain->lock);
for (i = 0; i < n; i++, index++) {
struct probe **s;
for (s = &domain->probes[index % 255]; *s; s = &(*s)->next) {
@@ -88,7 +89,7 @@ void kobj_unmap(struct kobj_map *domain,
}
}
}
- up(domain->sem);
+ mutex_unlock(domain->lock);
kfree(found);
}

@@ -99,7 +100,7 @@ struct kobject *kobj_lookup(struct kobj_
unsigned long best = ~0UL;

retry:
- down(domain->sem);
+ mutex_lock(domain->lock);
for (p = domain->probes[MAJOR(dev) % 255]; p; p = p->next) {
struct kobject *(*probe)(dev_t, int *, void *);
struct module *owner;
@@ -120,7 +121,7 @@ retry:
module_put(owner);
continue;
}
- up(domain->sem);
+ mutex_unlock(domain->lock);
kobj = probe(dev, index, data);
/* Currently ->owner protects _only_ ->probe() itself. */
module_put(owner);
@@ -128,11 +129,11 @@ retry:
return kobj;
goto retry;
}
- up(domain->sem);
+ mutex_unlock(domain->lock);
return NULL;
}

-struct kobj_map *kobj_map_init(kobj_probe_t *base_probe, struct semaphore *sem)
+struct kobj_map *kobj_map_init(kobj_probe_t *base_probe, struct mutex *lock)
{
struct kobj_map *p = kmalloc(sizeof(struct kobj_map), GFP_KERNEL);
struct probe *base = kzalloc(sizeof(*base), GFP_KERNEL);
@@ -149,6 +150,6 @@ struct kobj_map *kobj_map_init(kobj_prob
base->get = base_probe;
for (i = 0; i < 255; i++)
p->probes[i] = base;
- p->sem = sem;
+ p->lock = lock;
return p;
}
diff --git a/fs/char_dev.c b/fs/char_dev.c
index 21195c4..5c36345 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -19,6 +19,7 @@
#include <linux/kobject.h>
#include <linux/kobj_map.h>
#include <linux/cdev.h>
+#include <linux/mutex.h>

#ifdef CONFIG_KMOD
#include <linux/kmod.h>
@@ -28,7 +29,7 @@ static struct kobj_map *cdev_map;

#define MAX_PROBE_HASH 255 /* random */

-static DECLARE_MUTEX(chrdevs_lock);
+static DEFINE_MUTEX(chrdevs_lock);

static struct char_device_struct {
struct char_device_struct *next;
@@ -88,13 +89,13 @@ out:

void *acquire_chrdev_list(void)
{
- down(&chrdevs_lock);
+ mutex_lock(&chrdevs_lock);
return get_next_chrdev(NULL);
}

void release_chrdev_list(void *dev)
{
- up(&chrdevs_lock);
+ mutex_unlock(&chrdevs_lock);
kfree(dev);
}

@@ -151,7 +152,7 @@ __register_chrdev_region(unsigned int ma

memset(cd, 0, sizeof(struct char_device_struct));

- down(&chrdevs_lock);
+ mutex_lock(&chrdevs_lock);

/* temporary */
if (major == 0) {
@@ -186,10 +187,10 @@ __register_chrdev_region(unsigned int ma
}
cd->next = *cp;
*cp = cd;
- up(&chrdevs_lock);
+ mutex_unlock(&chrdevs_lock);
return cd;
out:
- up(&chrdevs_lock);
+ mutex_unlock(&chrdevs_lock);
kfree(cd);
return ERR_PTR(ret);
}
@@ -200,7 +201,7 @@ __unregister_chrdev_region(unsigned majo
struct char_device_struct *cd = NULL, **cp;
int i = major_to_index(major);

- down(&chrdevs_lock);
+ mutex_lock(&chrdevs_lock);
for (cp = &chrdevs[i]; *cp; cp = &(*cp)->next)
if ((*cp)->major == major &&
(*cp)->baseminor == baseminor &&
@@ -210,7 +211,7 @@ __unregister_chrdev_region(unsigned majo
cd = *cp;
*cp = cd->next;
}
- up(&chrdevs_lock);
+ mutex_unlock(&chrdevs_lock);
return cd;
}

diff --git a/include/linux/kobj_map.h b/include/linux/kobj_map.h
index cbe7d80..bafe178 100644
--- a/include/linux/kobj_map.h
+++ b/include/linux/kobj_map.h
@@ -1,6 +1,6 @@
#ifdef __KERNEL__

-#include <asm/semaphore.h>
+#include <linux/mutex.h>

typedef struct kobject *kobj_probe_t(dev_t, int *, void *);
struct kobj_map;
@@ -9,6 +9,6 @@ int kobj_map(struct kobj_map *, dev_t, u
kobj_probe_t *, int (*)(dev_t, void *), void *);
void kobj_unmap(struct kobj_map *, dev_t, unsigned long);
struct kobject *kobj_lookup(struct kobj_map *, dev_t, int *);
-struct kobj_map *kobj_map_init(kobj_probe_t *, struct semaphore *);
+struct kobj_map *kobj_map_init(kobj_probe_t *, struct mutex *);

#endif
--
1.2.4


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