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[SCSI] bsg: use lib/idr.c to find a unique minor number

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This replaces the current linear search for a unique minor number with
lib/idr.c.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This commit is contained in:
FUJITA Tomonori 2007-07-23 09:33:26 +09:00 committed by James Bottomley
parent 4b39c1d983
commit 598443a212
2 changed files with 31 additions and 41 deletions
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71
block/bsg.c
View File

@ -24,6 +24,7 @@
#include <linux/cdev.h>
#include <linux/percpu.h>
#include <linux/uio.h>
#include <linux/idr.h>
#include <linux/bsg.h>
#include <scsi/scsi.h>
@ -70,13 +71,12 @@ enum {
#endif
static DEFINE_MUTEX(bsg_mutex);
static int bsg_device_nr, bsg_minor_idx;
static DEFINE_IDR(bsg_minor_idr);
#define BSG_LIST_ARRAY_SIZE 8
static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
static struct class *bsg_class;
static LIST_HEAD(bsg_class_list);
static int bsg_major;
static struct kmem_cache *bsg_cmd_cachep;
@ -781,23 +781,18 @@ static struct bsg_device *__bsg_get_device(int minor)
static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
{
struct bsg_device *bd = __bsg_get_device(iminor(inode));
struct bsg_class_device *bcd, *__bcd;
struct bsg_device *bd;
struct bsg_class_device *bcd;
bd = __bsg_get_device(iminor(inode));
if (bd)
return bd;
/*
* find the class device
*/
bcd = NULL;
mutex_lock(&bsg_mutex);
list_for_each_entry(__bcd, &bsg_class_list, list) {
if (__bcd->minor == iminor(inode)) {
bcd = __bcd;
break;
}
}
bcd = idr_find(&bsg_minor_idr, iminor(inode));
mutex_unlock(&bsg_mutex);
if (!bcd)
@ -936,13 +931,12 @@ void bsg_unregister_queue(struct request_queue *q)
return;
mutex_lock(&bsg_mutex);
idr_remove(&bsg_minor_idr, bcd->minor);
sysfs_remove_link(&q->kobj, "bsg");
class_device_unregister(bcd->class_dev);
put_device(bcd->dev);
bcd->class_dev = NULL;
bcd->dev = NULL;
list_del_init(&bcd->list);
bsg_device_nr--;
mutex_unlock(&bsg_mutex);
}
EXPORT_SYMBOL_GPL(bsg_unregister_queue);
@ -950,9 +944,9 @@ EXPORT_SYMBOL_GPL(bsg_unregister_queue);
int bsg_register_queue(struct request_queue *q, struct device *gdev,
const char *name)
{
struct bsg_class_device *bcd, *__bcd;
struct bsg_class_device *bcd;
dev_t dev;
int ret = -EMFILE;
int ret, minor;
struct class_device *class_dev = NULL;
const char *devname;
@ -969,28 +963,26 @@ int bsg_register_queue(struct request_queue *q, struct device *gdev,
bcd = &q->bsg_dev;
memset(bcd, 0, sizeof(*bcd));
INIT_LIST_HEAD(&bcd->list);
mutex_lock(&bsg_mutex);
if (bsg_device_nr == BSG_MAX_DEVS) {
ret = idr_pre_get(&bsg_minor_idr, GFP_KERNEL);
if (!ret) {
ret = -ENOMEM;
goto unlock;
}
ret = idr_get_new(&bsg_minor_idr, bcd, &minor);
if (ret < 0)
goto unlock;
if (minor >= BSG_MAX_DEVS) {
printk(KERN_ERR "bsg: too many bsg devices\n");
goto err;
ret = -EINVAL;
goto remove_idr;
}
retry:
list_for_each_entry(__bcd, &bsg_class_list, list) {
if (__bcd->minor == bsg_minor_idx) {
bsg_minor_idx++;
if (bsg_minor_idx == BSG_MAX_DEVS)
bsg_minor_idx = 0;
goto retry;
}
}
bcd->minor = bsg_minor_idx++;
if (bsg_minor_idx == BSG_MAX_DEVS)
bsg_minor_idx = 0;
bcd->minor = minor;
bcd->queue = q;
bcd->dev = get_device(gdev);
dev = MKDEV(bsg_major, bcd->minor);
@ -998,27 +990,26 @@ int bsg_register_queue(struct request_queue *q, struct device *gdev,
devname);
if (IS_ERR(class_dev)) {
ret = PTR_ERR(class_dev);
goto err_put;
goto put_dev;
}
bcd->class_dev = class_dev;
if (q->kobj.sd) {
ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
if (ret)
goto err_unregister;
goto unregister_class_dev;
}
list_add_tail(&bcd->list, &bsg_class_list);
bsg_device_nr++;
mutex_unlock(&bsg_mutex);
return 0;
err_unregister:
unregister_class_dev:
class_device_unregister(class_dev);
err_put:
put_dev:
put_device(gdev);
err:
remove_idr:
idr_remove(&bsg_minor_idr, minor);
unlock:
mutex_unlock(&bsg_mutex);
return ret;
}

1
include/linux/bsg.h
View File

@ -53,7 +53,6 @@ struct bsg_class_device {
struct class_device *class_dev;
struct device *dev;
int minor;
struct list_head list;
struct request_queue *queue;
};