diff options
Diffstat (limited to 'block/bsg.c')
-rw-r--r-- | block/bsg.c | 491 |
1 files changed, 124 insertions, 367 deletions
diff --git a/block/bsg.c b/block/bsg.c index d7bae94b64d9..72157a59b788 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -15,339 +15,99 @@ #include <scsi/scsi.h> #include <scsi/scsi_ioctl.h> -#include <scsi/scsi_cmnd.h> -#include <scsi/scsi_device.h> -#include <scsi/scsi_driver.h> #include <scsi/sg.h> #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]; + struct device device; + struct cdev cdev; int max_queue; + unsigned int timeout; + unsigned int reserved_size; + bsg_sg_io_fn *sg_io_fn; }; -#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 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_scsi_check_proto(struct sg_io_v4 *hdr) +static inline struct bsg_device *to_bsg_device(struct inode *inode) { - if (hdr->protocol != BSG_PROTOCOL_SCSI || - hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_CMD) - return -EINVAL; - return 0; + return container_of(inode->i_cdev, struct bsg_device, cdev); } -static int bsg_scsi_fill_hdr(struct request *rq, struct sg_io_v4 *hdr, - fmode_t mode) -{ - struct scsi_request *sreq = scsi_req(rq); - - if (hdr->dout_xfer_len && hdr->din_xfer_len) { - pr_warn_once("BIDI support in bsg has been removed.\n"); - return -EOPNOTSUPP; - } - - sreq->cmd_len = hdr->request_len; - if (sreq->cmd_len > BLK_MAX_CDB) { - sreq->cmd = kzalloc(sreq->cmd_len, GFP_KERNEL); - if (!sreq->cmd) - return -ENOMEM; - } +#define BSG_DEFAULT_CMDS 64 +#define BSG_MAX_DEVS (1 << MINORBITS) - if (copy_from_user(sreq->cmd, uptr64(hdr->request), sreq->cmd_len)) - return -EFAULT; - if (blk_verify_command(sreq->cmd, mode)) - return -EPERM; - return 0; -} +static DEFINE_IDA(bsg_minor_ida); +static const struct class bsg_class; +static int bsg_major; -static int bsg_scsi_complete_rq(struct request *rq, struct sg_io_v4 *hdr) +static unsigned int bsg_timeout(struct bsg_device *bd, struct sg_io_v4 *hdr) { - struct scsi_request *sreq = scsi_req(rq); - int ret = 0; - - /* - * fill in all the output members - */ - hdr->device_status = sreq->result & 0xff; - hdr->transport_status = host_byte(sreq->result); - hdr->driver_status = driver_byte(sreq->result); - hdr->info = 0; - if (hdr->device_status || hdr->transport_status || hdr->driver_status) - hdr->info |= SG_INFO_CHECK; - hdr->response_len = 0; - - if (sreq->sense_len && hdr->response) { - int len = min_t(unsigned int, hdr->max_response_len, - sreq->sense_len); - - if (copy_to_user(uptr64(hdr->response), sreq->sense, len)) - ret = -EFAULT; - else - hdr->response_len = len; - } - - if (rq_data_dir(rq) == READ) - hdr->din_resid = sreq->resid_len; - else - hdr->dout_resid = sreq->resid_len; + unsigned int timeout = BLK_DEFAULT_SG_TIMEOUT; - return ret; -} + if (hdr->timeout) + timeout = msecs_to_jiffies(hdr->timeout); + else if (bd->timeout) + timeout = bd->timeout; -static void bsg_scsi_free_rq(struct request *rq) -{ - scsi_req_free_cmd(scsi_req(rq)); + return max_t(unsigned int, timeout, BLK_MIN_SG_TIMEOUT); } -static const struct bsg_ops bsg_scsi_ops = { - .check_proto = bsg_scsi_check_proto, - .fill_hdr = bsg_scsi_fill_hdr, - .complete_rq = bsg_scsi_complete_rq, - .free_rq = bsg_scsi_free_rq, -}; - -static int bsg_sg_io(struct request_queue *q, fmode_t mode, void __user *uarg) +static int bsg_sg_io(struct bsg_device *bd, bool open_for_write, + void __user *uarg) { - struct request *rq; - struct bio *bio; struct sg_io_v4 hdr; int ret; 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); - if (ret) - return ret; - - rq = blk_get_request(q, hdr.dout_xfer_len ? - REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0); - if (IS_ERR(rq)) - return PTR_ERR(rq); - - ret = q->bsg_dev.ops->fill_hdr(rq, &hdr, mode); - if (ret) - return ret; - - rq->timeout = msecs_to_jiffies(hdr.timeout); - if (!rq->timeout) - rq->timeout = 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), - hdr.dout_xfer_len, GFP_KERNEL); - } else if (hdr.din_xfer_len) { - ret = blk_rq_map_user(q, rq, NULL, uptr64(hdr.din_xferp), - hdr.din_xfer_len, GFP_KERNEL); - } - - if (ret) - goto out_free_rq; - - bio = rq->bio; - - blk_execute_rq(q, NULL, rq, !(hdr.flags & BSG_FLAG_Q_AT_TAIL)); - ret = rq->q->bsg_dev.ops->complete_rq(rq, &hdr); - blk_rq_unmap_user(bio); - -out_free_rq: - rq->q->bsg_dev.ops->free_rq(rq); - blk_put_request(rq); + ret = bd->sg_io_fn(bd->queue, &hdr, open_for_write, + bsg_timeout(bd, &hdr)); 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; + int val; switch (cmd) { /* @@ -362,17 +122,37 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg) * SCSI/sg ioctls */ case SG_GET_VERSION_NUM: + return put_user(30527, intp); case SCSI_IOCTL_GET_IDLUN: + return put_user(0, intp); case SCSI_IOCTL_GET_BUS_NUMBER: + return put_user(0, intp); case SG_SET_TIMEOUT: + if (get_user(val, intp)) + return -EFAULT; + bd->timeout = clock_t_to_jiffies(val); + return 0; case SG_GET_TIMEOUT: + return jiffies_to_clock_t(bd->timeout); case SG_GET_RESERVED_SIZE: + return put_user(min(bd->reserved_size, queue_max_bytes(q)), + intp); case SG_SET_RESERVED_SIZE: + if (get_user(val, intp)) + return -EFAULT; + if (val < 0) + return -EINVAL; + bd->reserved_size = + min_t(unsigned int, val, queue_max_bytes(q)); + return 0; case SG_EMULATED_HOST: - case SCSI_IOCTL_SEND_COMMAND: - return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg); + return put_user(1, intp); case SG_IO: - return bsg_sg_io(bd->queue, file->f_mode, uarg); + return bsg_sg_io(bd, file->f_mode & FMODE_WRITE, uarg); + case SCSI_IOCTL_SEND_COMMAND: + pr_warn_ratelimited("%s: calling unsupported SCSI_IOCTL_SEND_COMMAND\n", + current->comm); + return -EINVAL; default: return -ENOTTY; } @@ -387,129 +167,106 @@ static const struct file_operations bsg_fops = { .llseek = default_llseek, }; -void bsg_unregister_queue(struct request_queue *q) +static void bsg_device_release(struct device *dev) { - 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); + struct bsg_device *bd = container_of(dev, struct bsg_device, device); + + ida_free(&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) +void bsg_unregister_queue(struct bsg_device *bd) { - struct bsg_class_device *bcd; - dev_t dev; - int ret; - struct device *class_dev = NULL; + struct gendisk *disk = bd->queue->disk; - /* - * we need a proper transport to send commands, not a stacked device - */ - if (!queue_is_mq(q)) - return 0; + if (disk && disk->queue_kobj.sd) + sysfs_remove_link(&disk->queue_kobj, "bsg"); + cdev_device_del(&bd->cdev, &bd->device); + put_device(&bd->device); +} +EXPORT_SYMBOL_GPL(bsg_unregister_queue); - bcd = &q->bsg_dev; - memset(bcd, 0, sizeof(*bcd)); +struct bsg_device *bsg_register_queue(struct request_queue *q, + struct device *parent, const char *name, bsg_sg_io_fn *sg_io_fn) +{ + struct bsg_device *bd; + int ret; - mutex_lock(&bsg_mutex); + bd = kzalloc(sizeof(*bd), GFP_KERNEL); + if (!bd) + return ERR_PTR(-ENOMEM); + bd->max_queue = BSG_DEFAULT_CMDS; + bd->reserved_size = INT_MAX; + bd->queue = q; + bd->sg_io_fn = sg_io_fn; - ret = idr_alloc(&bsg_minor_idr, bcd, 0, BSG_MAX_DEVS, GFP_KERNEL); + ret = ida_alloc_max(&bsg_minor_ida, BSG_MAX_DEVS - 1, GFP_KERNEL); if (ret < 0) { - if (ret == -ENOSPC) { - printk(KERN_ERR "bsg: too many bsg devices\n"); - ret = -EINVAL; - } - goto unlock; + if (ret == -ENOSPC) + dev_err(parent, "bsg: too many bsg devices\n"); + kfree(bd); + return ERR_PTR(ret); } + bd->device.devt = MKDEV(bsg_major, ret); + bd->device.class = &bsg_class; + bd->device.parent = parent; + bd->device.release = bsg_device_release; + 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_put_device; - 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; - } - bcd->class_dev = class_dev; - - if (q->kobj.sd) { - ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg"); + if (q->disk && q->disk->queue_kobj.sd) { + ret = sysfs_create_link(&q->disk->queue_kobj, &bd->device.kobj, + "bsg"); if (ret) - goto unregister_class_dev; + goto out_device_del; } - mutex_unlock(&bsg_mutex); - return 0; - -unregister_class_dev: - device_unregister(class_dev); -idr_remove: - idr_remove(&bsg_minor_idr, bcd->minor); -unlock: - mutex_unlock(&bsg_mutex); - return ret; -} - -int bsg_scsi_register_queue(struct request_queue *q, struct device *parent) -{ - if (!blk_queue_scsi_passthrough(q)) { - WARN_ONCE(true, "Attempt to register a non-SCSI queue\n"); - return -EINVAL; - } + return bd; - return bsg_register_queue(q, parent, dev_name(parent), &bsg_scsi_ops); +out_device_del: + cdev_device_del(&bd->cdev, &bd->device); +out_put_device: + put_device(&bd->device); + return ERR_PTR(ret); } -EXPORT_SYMBOL_GPL(bsg_scsi_register_queue); - -static struct cdev bsg_cdev; +EXPORT_SYMBOL_GPL(bsg_register_queue); -static char *bsg_devnode(struct device *dev, umode_t *mode) +static char *bsg_devnode(const struct device *dev, umode_t *mode) { return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev)); } +static const struct class bsg_class = { + .name = "bsg", + .devnode = bsg_devnode, +}; + static int __init bsg_init(void) { - int ret, i; dev_t devid; + int ret; - for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++) - INIT_HLIST_HEAD(&bsg_device_list[i]); - - bsg_class = class_create(THIS_MODULE, "bsg"); - if (IS_ERR(bsg_class)) - return PTR_ERR(bsg_class); - bsg_class->devnode = bsg_devnode; + ret = class_register(&bsg_class); + if (ret) + return ret; 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); + class_unregister(&bsg_class); return ret; } |