#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
#define BSG_VERSION "0.4"
-#define bsg_dbg(bd, fmt, ...) \
- pr_debug("%s: " fmt, (bd)->name, ##__VA_ARGS__)
-
struct bsg_device {
struct request_queue *queue;
- spinlock_t lock;
- struct hlist_node dev_list;
- refcount_t ref_count;
- char name[20];
+ const struct bsg_ops *ops;
+ struct device device;
+ struct cdev cdev;
int max_queue;
};
+static inline struct bsg_device *to_bsg_device(struct inode *inode)
+{
+ return container_of(inode->i_cdev, struct bsg_device, cdev);
+}
+
#define BSG_DEFAULT_CMDS 64
#define BSG_MAX_DEVS 32768
-static DEFINE_MUTEX(bsg_mutex);
-static DEFINE_IDR(bsg_minor_idr);
-
-#define BSG_LIST_ARRAY_SIZE 8
-static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
-
+static DEFINE_IDA(bsg_minor_ida);
static struct class *bsg_class;
static int bsg_major;
-static inline struct hlist_head *bsg_dev_idx_hash(int index)
-{
- return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
-}
-
#define uptr64(val) ((void __user *)(uintptr_t)(val))
-static int bsg_sg_io(struct request_queue *q, fmode_t mode, void __user *uarg)
+static int bsg_sg_io(struct bsg_device *bd, fmode_t mode, void __user *uarg)
{
struct request *rq;
struct bio *bio;
if (copy_from_user(&hdr, uarg, sizeof(hdr)))
return -EFAULT;
- if (!q->bsg_dev.class_dev)
- return -ENXIO;
-
if (hdr.guard != 'Q')
return -EINVAL;
- ret = q->bsg_dev.ops->check_proto(&hdr);
+ ret = bd->ops->check_proto(&hdr);
if (ret)
return ret;
- rq = blk_get_request(q, hdr.dout_xfer_len ?
+ rq = blk_get_request(bd->queue, hdr.dout_xfer_len ?
REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
if (IS_ERR(rq))
return PTR_ERR(rq);
- ret = q->bsg_dev.ops->fill_hdr(rq, &hdr, mode);
+ ret = bd->ops->fill_hdr(rq, &hdr, mode);
if (ret) {
blk_put_request(rq);
return ret;
rq->timeout = msecs_to_jiffies(hdr.timeout);
if (!rq->timeout)
- rq->timeout = q->sg_timeout;
+ rq->timeout = rq->q->sg_timeout;
if (!rq->timeout)
rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
if (rq->timeout < BLK_MIN_SG_TIMEOUT)
rq->timeout = BLK_MIN_SG_TIMEOUT;
if (hdr.dout_xfer_len) {
- ret = blk_rq_map_user(q, rq, NULL, uptr64(hdr.dout_xferp),
+ ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr.dout_xferp),
hdr.dout_xfer_len, GFP_KERNEL);
} else if (hdr.din_xfer_len) {
- ret = blk_rq_map_user(q, rq, NULL, uptr64(hdr.din_xferp),
+ ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr.din_xferp),
hdr.din_xfer_len, GFP_KERNEL);
}
bio = rq->bio;
blk_execute_rq(NULL, rq, !(hdr.flags & BSG_FLAG_Q_AT_TAIL));
- ret = rq->q->bsg_dev.ops->complete_rq(rq, &hdr);
+ ret = bd->ops->complete_rq(rq, &hdr);
blk_rq_unmap_user(bio);
out_free_rq:
- rq->q->bsg_dev.ops->free_rq(rq);
+ bd->ops->free_rq(rq);
blk_put_request(rq);
if (!ret && copy_to_user(uarg, &hdr, sizeof(hdr)))
return -EFAULT;
return ret;
}
-static struct bsg_device *bsg_alloc_device(void)
-{
- struct bsg_device *bd;
-
- bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
- if (unlikely(!bd))
- return NULL;
-
- spin_lock_init(&bd->lock);
- bd->max_queue = BSG_DEFAULT_CMDS;
- INIT_HLIST_NODE(&bd->dev_list);
- return bd;
-}
-
-static int bsg_put_device(struct bsg_device *bd)
-{
- struct request_queue *q = bd->queue;
-
- mutex_lock(&bsg_mutex);
-
- if (!refcount_dec_and_test(&bd->ref_count)) {
- mutex_unlock(&bsg_mutex);
- return 0;
- }
-
- hlist_del(&bd->dev_list);
- mutex_unlock(&bsg_mutex);
-
- bsg_dbg(bd, "tearing down\n");
-
- /*
- * close can always block
- */
- kfree(bd);
- blk_put_queue(q);
- return 0;
-}
-
-static struct bsg_device *bsg_add_device(struct inode *inode,
- struct request_queue *rq,
- struct file *file)
-{
- struct bsg_device *bd;
- unsigned char buf[32];
-
- lockdep_assert_held(&bsg_mutex);
-
- if (!blk_get_queue(rq))
- return ERR_PTR(-ENXIO);
-
- bd = bsg_alloc_device();
- if (!bd) {
- blk_put_queue(rq);
- return ERR_PTR(-ENOMEM);
- }
-
- bd->queue = rq;
-
- refcount_set(&bd->ref_count, 1);
- hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
-
- strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
- bsg_dbg(bd, "bound to <%s>, max queue %d\n",
- format_dev_t(buf, inode->i_rdev), bd->max_queue);
-
- return bd;
-}
-
-static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
-{
- struct bsg_device *bd;
-
- lockdep_assert_held(&bsg_mutex);
-
- hlist_for_each_entry(bd, bsg_dev_idx_hash(minor), dev_list) {
- if (bd->queue == q) {
- refcount_inc(&bd->ref_count);
- goto found;
- }
- }
- bd = NULL;
-found:
- return bd;
-}
-
-static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
-{
- struct bsg_device *bd;
- struct bsg_class_device *bcd;
-
- /*
- * find the class device
- */
- mutex_lock(&bsg_mutex);
- bcd = idr_find(&bsg_minor_idr, iminor(inode));
-
- if (!bcd) {
- bd = ERR_PTR(-ENODEV);
- goto out_unlock;
- }
-
- bd = __bsg_get_device(iminor(inode), bcd->queue);
- if (!bd)
- bd = bsg_add_device(inode, bcd->queue, file);
-
-out_unlock:
- mutex_unlock(&bsg_mutex);
- return bd;
-}
-
static int bsg_open(struct inode *inode, struct file *file)
{
- struct bsg_device *bd;
-
- bd = bsg_get_device(inode, file);
-
- if (IS_ERR(bd))
- return PTR_ERR(bd);
-
- file->private_data = bd;
+ if (!blk_get_queue(to_bsg_device(inode)->queue))
+ return -ENXIO;
return 0;
}
static int bsg_release(struct inode *inode, struct file *file)
{
- struct bsg_device *bd = file->private_data;
-
- file->private_data = NULL;
- return bsg_put_device(bd);
+ blk_put_queue(to_bsg_device(inode)->queue);
+ return 0;
}
static int bsg_get_command_q(struct bsg_device *bd, int __user *uarg)
{
- return put_user(bd->max_queue, uarg);
+ return put_user(READ_ONCE(bd->max_queue), uarg);
}
static int bsg_set_command_q(struct bsg_device *bd, int __user *uarg)
{
- int queue;
+ int max_queue;
- if (get_user(queue, uarg))
+ if (get_user(max_queue, uarg))
return -EFAULT;
- if (queue < 1)
+ if (max_queue < 1)
return -EINVAL;
-
- spin_lock_irq(&bd->lock);
- bd->max_queue = queue;
- spin_unlock_irq(&bd->lock);
+ WRITE_ONCE(bd->max_queue, max_queue);
return 0;
}
static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
- struct bsg_device *bd = file->private_data;
+ struct bsg_device *bd = to_bsg_device(file_inode(file));
struct request_queue *q = bd->queue;
void __user *uarg = (void __user *) arg;
int __user *intp = uarg;
case SG_EMULATED_HOST:
return put_user(1, intp);
case SG_IO:
- return bsg_sg_io(q, file->f_mode, uarg);
+ return bsg_sg_io(bd, file->f_mode, uarg);
case SCSI_IOCTL_SEND_COMMAND:
pr_warn_ratelimited("%s: calling unsupported SCSI_IOCTL_SEND_COMMAND\n",
current->comm);
.llseek = default_llseek,
};
-void bsg_unregister_queue(struct request_queue *q)
+void bsg_unregister_queue(struct bsg_device *bd)
{
- struct bsg_class_device *bcd = &q->bsg_dev;
-
- if (!bcd->class_dev)
- return;
-
- mutex_lock(&bsg_mutex);
- idr_remove(&bsg_minor_idr, bcd->minor);
- if (q->kobj.sd)
- sysfs_remove_link(&q->kobj, "bsg");
- device_unregister(bcd->class_dev);
- bcd->class_dev = NULL;
- mutex_unlock(&bsg_mutex);
+ if (bd->queue->kobj.sd)
+ sysfs_remove_link(&bd->queue->kobj, "bsg");
+ cdev_device_del(&bd->cdev, &bd->device);
+ ida_simple_remove(&bsg_minor_ida, MINOR(bd->device.devt));
+ kfree(bd);
}
EXPORT_SYMBOL_GPL(bsg_unregister_queue);
-int bsg_register_queue(struct request_queue *q, struct device *parent,
- const char *name, const struct bsg_ops *ops)
+struct bsg_device *bsg_register_queue(struct request_queue *q,
+ struct device *parent, const char *name,
+ const struct bsg_ops *ops)
{
- struct bsg_class_device *bcd;
- dev_t dev;
+ struct bsg_device *bd;
int ret;
- struct device *class_dev = NULL;
-
- /*
- * we need a proper transport to send commands, not a stacked device
- */
- if (!queue_is_mq(q))
- return 0;
- bcd = &q->bsg_dev;
- memset(bcd, 0, sizeof(*bcd));
-
- mutex_lock(&bsg_mutex);
+ bd = kzalloc(sizeof(*bd), GFP_KERNEL);
+ if (!bd)
+ return ERR_PTR(-ENOMEM);
+ bd->max_queue = BSG_DEFAULT_CMDS;
+ bd->queue = q;
+ bd->ops = ops;
- ret = idr_alloc(&bsg_minor_idr, bcd, 0, BSG_MAX_DEVS, GFP_KERNEL);
+ ret = ida_simple_get(&bsg_minor_ida, 0, BSG_MAX_DEVS, GFP_KERNEL);
if (ret < 0) {
- if (ret == -ENOSPC) {
- printk(KERN_ERR "bsg: too many bsg devices\n");
- ret = -EINVAL;
- }
- goto unlock;
- }
-
- bcd->minor = ret;
- bcd->queue = q;
- bcd->ops = ops;
- dev = MKDEV(bsg_major, bcd->minor);
- class_dev = device_create(bsg_class, parent, dev, NULL, "%s", name);
- if (IS_ERR(class_dev)) {
- ret = PTR_ERR(class_dev);
- goto idr_remove;
+ if (ret == -ENOSPC)
+ dev_err(parent, "bsg: too many bsg devices\n");
+ goto out_kfree;
}
- bcd->class_dev = class_dev;
+ bd->device.devt = MKDEV(bsg_major, ret);
+ bd->device.class = bsg_class;
+ bd->device.parent = parent;
+ dev_set_name(&bd->device, "%s", name);
+ device_initialize(&bd->device);
+
+ cdev_init(&bd->cdev, &bsg_fops);
+ bd->cdev.owner = THIS_MODULE;
+ ret = cdev_device_add(&bd->cdev, &bd->device);
+ if (ret)
+ goto out_ida_remove;
if (q->kobj.sd) {
- ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
+ ret = sysfs_create_link(&q->kobj, &bd->device.kobj, "bsg");
if (ret)
- goto unregister_class_dev;
+ goto out_device_del;
}
- mutex_unlock(&bsg_mutex);
- return 0;
+ return bd;
-unregister_class_dev:
- device_unregister(class_dev);
-idr_remove:
- idr_remove(&bsg_minor_idr, bcd->minor);
-unlock:
- mutex_unlock(&bsg_mutex);
- return ret;
+out_device_del:
+ cdev_device_del(&bd->cdev, &bd->device);
+out_ida_remove:
+ ida_simple_remove(&bsg_minor_ida, MINOR(bd->device.devt));
+out_kfree:
+ kfree(bd);
+ return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(bsg_register_queue);
-static struct cdev bsg_cdev;
-
static char *bsg_devnode(struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
static int __init bsg_init(void)
{
- int ret, i;
dev_t devid;
-
- for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
- INIT_HLIST_HEAD(&bsg_device_list[i]);
+ int ret;
bsg_class = class_create(THIS_MODULE, "bsg");
if (IS_ERR(bsg_class))
ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
if (ret)
goto destroy_bsg_class;
-
bsg_major = MAJOR(devid);
- cdev_init(&bsg_cdev, &bsg_fops);
- ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
- if (ret)
- goto unregister_chrdev;
-
printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
" loaded (major %d)\n", bsg_major);
return 0;
-unregister_chrdev:
- unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
+
destroy_bsg_class:
class_destroy(bsg_class);
return ret;
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