[PATCH] kobj_map semaphore to mutex conversion

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@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 38 insertions, 35 deletions

diff --git a/block/genhd.c b/block/genhd.c
index db57546a709d..64510fd88621 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, const char *name)
         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, const char *name)
                 kfree(p);
         }
 out:
-        up(&block_subsys_sem);
+        mutex_unlock(&block_subsys_lock);
         return ret;
 }
 
@@ -197,7 +198,7 @@ int unregister_blkdev(unsigned int major, const char *name)
         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, const char *name)
                 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 *part, loff_t *pos)
         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 *part, void *v, loff_t *pos)
 
 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 dev, int *part, void *data)
 
 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_file *part, loff_t *pos)
         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_file *part, void *v, loff_t *pos)
 
 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 b449dae6f0d3..e87017f36853 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, dev_t dev, unsigned long range,
                 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, dev_t dev, unsigned long range,
                 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, dev_t dev, unsigned long range)
         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, dev_t dev, unsigned long range)
                         }
                 }
         }
-        up(domain->sem);
+        mutex_unlock(domain->lock);
         kfree(found);
 }
 
@@ -99,7 +100,7 @@ struct kobject *kobj_lookup(struct kobj_map *domain, dev_t dev, int *index)
         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_probe_t *base_probe, struct semaphore *sem)
         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 21195c481637..5c36345c9bf7 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 major, unsigned int baseminor,
 
         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 major, unsigned int baseminor,
         }
         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 major, unsigned baseminor, int minorct)
         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 major, unsigned baseminor, int minorct)
                 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 cbe7d8008042..bafe178a381f 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, unsigned long, struct module *,
              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