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Commit 58383af6 authored by Jes Sorensen's avatar Jes Sorensen Committed by Greg Kroah-Hartman
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[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: default avatarJes Sorensen <jes@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 8b5536bb

block/genhd.c

+16 −15
Original line number Diff line number Diff line
@@ -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 @@ void *get_next_blkdev(void *dev) 


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)

drivers/base/map.c

+11 −10
Original line number Diff line number Diff line
@@ -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 @@ struct kobject *kobj_lookup(struct kobj_map *domain, dev_t dev, int *index) 
			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 @@ struct kobject *kobj_lookup(struct kobj_map *domain, dev_t dev, int *index) 
			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;

}

fs/char_dev.c

+9 −8
Original line number Diff line number Diff line
@@ -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 @@ void *get_next_chrdev(void *dev) 


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;

}

include/linux/kobj_map.h

+2 −2
Original line number Diff line number Diff line 
#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