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-rw-r--r--block/bsg.c49
1 files changed, 41 insertions, 8 deletions
diff --git a/block/bsg.c b/block/bsg.c
index cd0221c61bfe..4ef3cc550244 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -58,6 +58,7 @@ enum {
};
#define BSG_DEFAULT_CMDS 64
+#define BSG_MAX_DEVS 32768
#undef BSG_DEBUG
@@ -75,7 +76,7 @@ enum {
#define BSG_MAJOR (240)
static DEFINE_MUTEX(bsg_mutex);
-static int bsg_device_nr;
+static int bsg_device_nr, bsg_minor_idx;
#define BSG_LIST_SIZE (8)
#define bsg_list_idx(minor) ((minor) & (BSG_LIST_SIZE - 1))
@@ -957,14 +958,15 @@ void bsg_unregister_queue(struct request_queue *q)
class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor));
bcd->class_dev = NULL;
list_del_init(&bcd->list);
+ bsg_device_nr--;
mutex_unlock(&bsg_mutex);
}
int bsg_register_queue(struct request_queue *q, char *name)
{
- struct bsg_class_device *bcd;
+ struct bsg_class_device *bcd, *__bcd;
dev_t dev;
- int ret;
+ int ret = -EMFILE;
struct class_device *class_dev = NULL;
/*
@@ -978,10 +980,27 @@ int bsg_register_queue(struct request_queue *q, char *name)
INIT_LIST_HEAD(&bcd->list);
mutex_lock(&bsg_mutex);
- dev = MKDEV(BSG_MAJOR, bsg_device_nr);
- bcd->minor = bsg_device_nr;
- bsg_device_nr++;
+ if (bsg_device_nr == BSG_MAX_DEVS) {
+ printk(KERN_ERR "bsg: too many bsg devices\n");
+ goto err;
+ }
+
+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->queue = q;
+ dev = MKDEV(BSG_MAJOR, bcd->minor);
class_dev = class_device_create(bsg_class, NULL, dev, bcd->dev, "%s", name);
if (IS_ERR(class_dev)) {
ret = PTR_ERR(class_dev);
@@ -996,11 +1015,11 @@ int bsg_register_queue(struct request_queue *q, char *name)
}
list_add_tail(&bcd->list, &bsg_class_list);
+ bsg_device_nr++;
mutex_unlock(&bsg_mutex);
return 0;
err:
- bsg_device_nr--;
if (class_dev)
class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor));
mutex_unlock(&bsg_mutex);
@@ -1030,6 +1049,11 @@ static struct class_interface bsg_intf = {
.remove = bsg_remove,
};
+static struct cdev bsg_cdev = {
+ .kobj = {.name = "bsg", },
+ .owner = THIS_MODULE,
+};
+
static int __init bsg_init(void)
{
int ret, i;
@@ -1050,10 +1074,19 @@ static int __init bsg_init(void)
return PTR_ERR(bsg_class);
}
- ret = register_chrdev(BSG_MAJOR, "bsg", &bsg_fops);
+ ret = register_chrdev_region(MKDEV(BSG_MAJOR, 0), BSG_MAX_DEVS, "bsg");
+ if (ret) {
+ kmem_cache_destroy(bsg_cmd_cachep);
+ class_destroy(bsg_class);
+ return ret;
+ }
+
+ cdev_init(&bsg_cdev, &bsg_fops);
+ ret = cdev_add(&bsg_cdev, MKDEV(BSG_MAJOR, 0), BSG_MAX_DEVS);
if (ret) {
kmem_cache_destroy(bsg_cmd_cachep);
class_destroy(bsg_class);
+ unregister_chrdev_region(MKDEV(BSG_MAJOR, 0), BSG_MAX_DEVS);
return ret;
}