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block/bsg.c 23.7 KB
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  /*
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   * bsg.c - block layer implementation of the sg v4 interface
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   *
   * Copyright (C) 2004 Jens Axboe <axboe@suse.de> SUSE Labs
   * Copyright (C) 2004 Peter M. Jones <pjones@redhat.com>
   *
   *  This file is subject to the terms and conditions of the GNU General Public
   *  License version 2.  See the file "COPYING" in the main directory of this
   *  archive for more details.
   *
   */
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  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/file.h>
  #include <linux/blkdev.h>
  #include <linux/poll.h>
  #include <linux/cdev.h>
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  #include <linux/jiffies.h>
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  #include <linux/percpu.h>
  #include <linux/uio.h>
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  #include <linux/idr.h>
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  #include <linux/bsg.h>
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  #include <linux/slab.h>
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  #include <scsi/scsi.h>
  #include <scsi/scsi_ioctl.h>
  #include <scsi/scsi_cmnd.h>
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  #include <scsi/scsi_device.h>
  #include <scsi/scsi_driver.h>
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  #include <scsi/sg.h>
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  #define BSG_DESCRIPTION	"Block layer SCSI generic (bsg) driver"
  #define BSG_VERSION	"0.4"
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  struct bsg_device {
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  	struct request_queue *queue;
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  	spinlock_t lock;
  	struct list_head busy_list;
  	struct list_head done_list;
  	struct hlist_node dev_list;
  	atomic_t ref_count;
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  	int queued_cmds;
  	int done_cmds;
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  	wait_queue_head_t wq_done;
  	wait_queue_head_t wq_free;
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  	char name[20];
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  	int max_queue;
  	unsigned long flags;
  };
  
  enum {
  	BSG_F_BLOCK		= 1,
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  };
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  #define BSG_DEFAULT_CMDS	64
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  #define BSG_MAX_DEVS		32768
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  #undef BSG_DEBUG
  
  #ifdef BSG_DEBUG
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  #define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ##args)
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  #else
  #define dprintk(fmt, args...)
  #endif
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  static DEFINE_MUTEX(bsg_mutex);
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  static DEFINE_IDR(bsg_minor_idr);
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  #define BSG_LIST_ARRAY_SIZE	8
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  static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
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  static struct class *bsg_class;
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  static int bsg_major;
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  static struct kmem_cache *bsg_cmd_cachep;
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  /*
   * our internal command type
   */
  struct bsg_command {
  	struct bsg_device *bd;
  	struct list_head list;
  	struct request *rq;
  	struct bio *bio;
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  	struct bio *bidi_bio;
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  	int err;
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  	struct sg_io_v4 hdr;
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  	char sense[SCSI_SENSE_BUFFERSIZE];
  };
  
  static void bsg_free_command(struct bsg_command *bc)
  {
  	struct bsg_device *bd = bc->bd;
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  	unsigned long flags;
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  	kmem_cache_free(bsg_cmd_cachep, bc);
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  	spin_lock_irqsave(&bd->lock, flags);
  	bd->queued_cmds--;
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  	spin_unlock_irqrestore(&bd->lock, flags);
  
  	wake_up(&bd->wq_free);
  }
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  static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
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  {
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  	struct bsg_command *bc = ERR_PTR(-EINVAL);
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  	spin_lock_irq(&bd->lock);
  
  	if (bd->queued_cmds >= bd->max_queue)
  		goto out;
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  	bd->queued_cmds++;
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  	spin_unlock_irq(&bd->lock);
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  	bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
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  	if (unlikely(!bc)) {
  		spin_lock_irq(&bd->lock);
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  		bd->queued_cmds--;
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  		bc = ERR_PTR(-ENOMEM);
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  		goto out;
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  	}
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  	bc->bd = bd;
  	INIT_LIST_HEAD(&bc->list);
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  	dprintk("%s: returning free cmd %p
  ", bd->name, bc);
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  	return bc;
  out:
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  	spin_unlock_irq(&bd->lock);
  	return bc;
  }
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  static inline struct hlist_head *bsg_dev_idx_hash(int index)
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  {
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  	return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
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  }
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  static int bsg_io_schedule(struct bsg_device *bd)
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  {
  	DEFINE_WAIT(wait);
  	int ret = 0;
  
  	spin_lock_irq(&bd->lock);
  
  	BUG_ON(bd->done_cmds > bd->queued_cmds);
  
  	/*
  	 * -ENOSPC or -ENODATA?  I'm going for -ENODATA, meaning "I have no
  	 * work to do", even though we return -ENOSPC after this same test
  	 * during bsg_write() -- there, it means our buffer can't have more
  	 * bsg_commands added to it, thus has no space left.
  	 */
  	if (bd->done_cmds == bd->queued_cmds) {
  		ret = -ENODATA;
  		goto unlock;
  	}
  
  	if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
  		ret = -EAGAIN;
  		goto unlock;
  	}
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  	prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE);
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  	spin_unlock_irq(&bd->lock);
  	io_schedule();
  	finish_wait(&bd->wq_done, &wait);
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  	return ret;
  unlock:
  	spin_unlock_irq(&bd->lock);
  	return ret;
  }
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  static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
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  				struct sg_io_v4 *hdr, struct bsg_device *bd,
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  				fmode_t has_write_perm)
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  {
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  	if (hdr->request_len > BLK_MAX_CDB) {
  		rq->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
  		if (!rq->cmd)
  			return -ENOMEM;
  	}
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  	if (copy_from_user(rq->cmd, (void __user *)(unsigned long)hdr->request,
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  			   hdr->request_len))
  		return -EFAULT;
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  	if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
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  		if (blk_verify_command(rq->cmd, has_write_perm))
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  			return -EPERM;
  	} else if (!capable(CAP_SYS_RAWIO))
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  		return -EPERM;
  
  	/*
  	 * fill in request structure
  	 */
  	rq->cmd_len = hdr->request_len;
  	rq->cmd_type = REQ_TYPE_BLOCK_PC;
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  	rq->timeout = msecs_to_jiffies(hdr->timeout);
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  	if (!rq->timeout)
  		rq->timeout = q->sg_timeout;
  	if (!rq->timeout)
  		rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
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  	if (rq->timeout < BLK_MIN_SG_TIMEOUT)
  		rq->timeout = BLK_MIN_SG_TIMEOUT;
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  	return 0;
  }
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  /*
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   * Check if sg_io_v4 from user is allowed and valid
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   */
  static int
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  bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw)
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  {
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  	int ret = 0;
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  	if (hdr->guard != 'Q')
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  		return -EINVAL;
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  	switch (hdr->protocol) {
  	case BSG_PROTOCOL_SCSI:
  		switch (hdr->subprotocol) {
  		case BSG_SUB_PROTOCOL_SCSI_CMD:
  		case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
  			break;
  		default:
  			ret = -EINVAL;
  		}
  		break;
  	default:
  		ret = -EINVAL;
  	}
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  	*rw = hdr->dout_xfer_len ? WRITE : READ;
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  	return ret;
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  }
  
  /*
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   * map sg_io_v4 to a request.
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   */
  static struct request *
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  bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
  	    u8 *sense)
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  {
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  	struct request_queue *q = bd->queue;
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  	struct request *rq, *next_rq = NULL;
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  	int ret, rw;
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  	unsigned int dxfer_len;
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  	void __user *dxferp = NULL;
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  	struct bsg_class_device *bcd = &q->bsg_dev;
  
  	/* if the LLD has been removed then the bsg_unregister_queue will
  	 * eventually be called and the class_dev was freed, so we can no
  	 * longer use this request_queue. Return no such address.
  	 */
  	if (!bcd->class_dev)
  		return ERR_PTR(-ENXIO);
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  	dprintk("map hdr %llx/%u %llx/%u
  ", (unsigned long long) hdr->dout_xferp,
  		hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
  		hdr->din_xfer_len);
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  	ret = bsg_validate_sgv4_hdr(q, hdr, &rw);
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  	if (ret)
  		return ERR_PTR(ret);
  
  	/*
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  	 * map scatter-gather elements separately and string them to request
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  	 */
  	rq = blk_get_request(q, rw, GFP_KERNEL);
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  	if (!rq)
  		return ERR_PTR(-ENOMEM);
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  	ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
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  	if (ret)
  		goto out;
  
  	if (rw == WRITE && hdr->din_xfer_len) {
  		if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
  			ret = -EOPNOTSUPP;
  			goto out;
  		}
  
  		next_rq = blk_get_request(q, READ, GFP_KERNEL);
  		if (!next_rq) {
  			ret = -ENOMEM;
  			goto out;
  		}
  		rq->next_rq = next_rq;
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  		next_rq->cmd_type = rq->cmd_type;
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  		dxferp = (void __user *)(unsigned long)hdr->din_xferp;
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  		ret =  blk_rq_map_user(q, next_rq, NULL, dxferp,
  				       hdr->din_xfer_len, GFP_KERNEL);
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  		if (ret)
  			goto out;
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  	}
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  	if (hdr->dout_xfer_len) {
  		dxfer_len = hdr->dout_xfer_len;
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  		dxferp = (void __user *)(unsigned long)hdr->dout_xferp;
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  	} else if (hdr->din_xfer_len) {
  		dxfer_len = hdr->din_xfer_len;
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  		dxferp = (void __user *)(unsigned long)hdr->din_xferp;
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  	} else
  		dxfer_len = 0;
  
  	if (dxfer_len) {
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  		ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
  				      GFP_KERNEL);
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  		if (ret)
  			goto out;
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  	}
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  	rq->sense = sense;
  	rq->sense_len = 0;
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  	return rq;
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  out:
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  	if (rq->cmd != rq->__cmd)
  		kfree(rq->cmd);
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  	blk_put_request(rq);
  	if (next_rq) {
  		blk_rq_unmap_user(next_rq->bio);
  		blk_put_request(next_rq);
  	}
  	return ERR_PTR(ret);
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  }
  
  /*
   * async completion call-back from the block layer, when scsi/ide/whatever
   * calls end_that_request_last() on a request
   */
  static void bsg_rq_end_io(struct request *rq, int uptodate)
  {
  	struct bsg_command *bc = rq->end_io_data;
  	struct bsg_device *bd = bc->bd;
  	unsigned long flags;
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  	dprintk("%s: finished rq %p bc %p, bio %p stat %d
  ",
  		bd->name, rq, bc, bc->bio, uptodate);
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  	bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
  
  	spin_lock_irqsave(&bd->lock, flags);
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  	list_move_tail(&bc->list, &bd->done_list);
  	bd->done_cmds++;
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  	spin_unlock_irqrestore(&bd->lock, flags);
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  	wake_up(&bd->wq_done);
3d6392cfb   Jens Axboe   bsg: support for ...
336
337
338
339
340
341
  }
  
  /*
   * do final setup of a 'bc' and submit the matching 'rq' to the block
   * layer for io
   */
165125e1e   Jens Axboe   [BLOCK] Get rid o...
342
  static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
3d6392cfb   Jens Axboe   bsg: support for ...
343
344
  			    struct bsg_command *bc, struct request *rq)
  {
05378940c   Boaz Harrosh   bsg: add support ...
345
  	int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
3d6392cfb   Jens Axboe   bsg: support for ...
346
347
348
349
350
  	/*
  	 * add bc command to busy queue and submit rq for io
  	 */
  	bc->rq = rq;
  	bc->bio = rq->bio;
2c9ecdf40   FUJITA Tomonori   bsg: add bidi sup...
351
352
  	if (rq->next_rq)
  		bc->bidi_bio = rq->next_rq->bio;
3d6392cfb   Jens Axboe   bsg: support for ...
353
354
355
356
357
358
359
360
361
  	bc->hdr.duration = jiffies;
  	spin_lock_irq(&bd->lock);
  	list_add_tail(&bc->list, &bd->busy_list);
  	spin_unlock_irq(&bd->lock);
  
  	dprintk("%s: queueing rq %p, bc %p
  ", bd->name, rq, bc);
  
  	rq->end_io_data = bc;
05378940c   Boaz Harrosh   bsg: add support ...
362
  	blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
3d6392cfb   Jens Axboe   bsg: support for ...
363
  }
25fd16430   Jens Axboe   bsg: address vari...
364
  static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
3d6392cfb   Jens Axboe   bsg: support for ...
365
366
367
368
369
  {
  	struct bsg_command *bc = NULL;
  
  	spin_lock_irq(&bd->lock);
  	if (bd->done_cmds) {
43ac9e62c   FUJITA Tomonori   [SCSI] bsg: use b...
370
  		bc = list_first_entry(&bd->done_list, struct bsg_command, list);
25fd16430   Jens Axboe   bsg: address vari...
371
372
  		list_del(&bc->list);
  		bd->done_cmds--;
3d6392cfb   Jens Axboe   bsg: support for ...
373
374
375
376
377
378
379
380
381
  	}
  	spin_unlock_irq(&bd->lock);
  
  	return bc;
  }
  
  /*
   * Get a finished command from the done list
   */
e7d721732   FUJITA Tomonori   bsg: fix a blocki...
382
  static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
3d6392cfb   Jens Axboe   bsg: support for ...
383
384
385
386
387
388
389
390
  {
  	struct bsg_command *bc;
  	int ret;
  
  	do {
  		bc = bsg_next_done_cmd(bd);
  		if (bc)
  			break;
e7d721732   FUJITA Tomonori   bsg: fix a blocki...
391
392
393
394
395
396
  		if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
  			bc = ERR_PTR(-EAGAIN);
  			break;
  		}
  
  		ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
3d6392cfb   Jens Axboe   bsg: support for ...
397
  		if (ret) {
e7d721732   FUJITA Tomonori   bsg: fix a blocki...
398
  			bc = ERR_PTR(-ERESTARTSYS);
3d6392cfb   Jens Axboe   bsg: support for ...
399
400
401
402
403
404
405
406
407
  			break;
  		}
  	} while (1);
  
  	dprintk("%s: returning done %p
  ", bd->name, bc);
  
  	return bc;
  }
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
408
  static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
2c9ecdf40   FUJITA Tomonori   bsg: add bidi sup...
409
  				    struct bio *bio, struct bio *bidi_bio)
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
410
411
  {
  	int ret = 0;
c1c201200   Boaz Harrosh   bsg: Fix sense bu...
412
413
  	dprintk("rq %p bio %p 0x%x
  ", rq, bio, rq->errors);
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
414
415
416
  	/*
  	 * fill in all the output members
  	 */
478971600   FUJITA Tomonori   [SCSI] bsg: fix i...
417
  	hdr->device_status = rq->errors & 0xff;
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
418
419
420
421
422
  	hdr->transport_status = host_byte(rq->errors);
  	hdr->driver_status = driver_byte(rq->errors);
  	hdr->info = 0;
  	if (hdr->device_status || hdr->transport_status || hdr->driver_status)
  		hdr->info |= SG_INFO_CHECK;
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
423
424
425
  	hdr->response_len = 0;
  
  	if (rq->sense_len && hdr->response) {
25fd16430   Jens Axboe   bsg: address vari...
426
427
  		int len = min_t(unsigned int, hdr->max_response_len,
  					rq->sense_len);
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
428

2b727c630   Namhyung Kim   bsg: fix address ...
429
  		ret = copy_to_user((void __user *)(unsigned long)hdr->response,
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
430
431
432
433
434
435
  				   rq->sense, len);
  		if (!ret)
  			hdr->response_len = len;
  		else
  			ret = -EFAULT;
  	}
2c9ecdf40   FUJITA Tomonori   bsg: add bidi sup...
436
  	if (rq->next_rq) {
c3a4d78c5   Tejun Heo   block: add rq->re...
437
438
  		hdr->dout_resid = rq->resid_len;
  		hdr->din_resid = rq->next_rq->resid_len;
2c9ecdf40   FUJITA Tomonori   bsg: add bidi sup...
439
440
  		blk_rq_unmap_user(bidi_bio);
  		blk_put_request(rq->next_rq);
0c6a89ba6   FUJITA Tomonori   [SCSI] bsg: updat...
441
  	} else if (rq_data_dir(rq) == READ)
c3a4d78c5   Tejun Heo   block: add rq->re...
442
  		hdr->din_resid = rq->resid_len;
0c6a89ba6   FUJITA Tomonori   [SCSI] bsg: updat...
443
  	else
c3a4d78c5   Tejun Heo   block: add rq->re...
444
  		hdr->dout_resid = rq->resid_len;
2c9ecdf40   FUJITA Tomonori   bsg: add bidi sup...
445

2d507a01d   James Bottomley   [SCSI] libsas, bs...
446
447
448
449
450
451
452
453
  	/*
  	 * If the request generated a negative error number, return it
  	 * (providing we aren't already returning an error); if it's
  	 * just a protocol response (i.e. non negative), that gets
  	 * processed above.
  	 */
  	if (!ret && rq->errors < 0)
  		ret = rq->errors;
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
454
  	blk_rq_unmap_user(bio);
9f5de6b10   FUJITA Tomonori   [SCSI] bsg: add l...
455
456
  	if (rq->cmd != rq->__cmd)
  		kfree(rq->cmd);
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
457
458
459
460
  	blk_put_request(rq);
  
  	return ret;
  }
3d6392cfb   Jens Axboe   bsg: support for ...
461
462
463
464
465
466
467
  static int bsg_complete_all_commands(struct bsg_device *bd)
  {
  	struct bsg_command *bc;
  	int ret, tret;
  
  	dprintk("%s: entered
  ", bd->name);
3d6392cfb   Jens Axboe   bsg: support for ...
468
469
470
471
472
  	/*
  	 * wait for all commands to complete
  	 */
  	ret = 0;
  	do {
25fd16430   Jens Axboe   bsg: address vari...
473
  		ret = bsg_io_schedule(bd);
3d6392cfb   Jens Axboe   bsg: support for ...
474
475
476
477
478
479
480
481
482
483
484
485
486
487
  		/*
  		 * look for -ENODATA specifically -- we'll sometimes get
  		 * -ERESTARTSYS when we've taken a signal, but we can't
  		 * return until we're done freeing the queue, so ignore
  		 * it.  The signal will get handled when we're done freeing
  		 * the bsg_device.
  		 */
  	} while (ret != -ENODATA);
  
  	/*
  	 * discard done commands
  	 */
  	ret = 0;
  	do {
e7d721732   FUJITA Tomonori   bsg: fix a blocki...
488
489
490
  		spin_lock_irq(&bd->lock);
  		if (!bd->queued_cmds) {
  			spin_unlock_irq(&bd->lock);
3d6392cfb   Jens Axboe   bsg: support for ...
491
492
  			break;
  		}
efba1a31f   FUJITA Tomonori   bsg: fix the dead...
493
  		spin_unlock_irq(&bd->lock);
3d6392cfb   Jens Axboe   bsg: support for ...
494

e7d721732   FUJITA Tomonori   bsg: fix a blocki...
495
496
497
  		bc = bsg_get_done_cmd(bd);
  		if (IS_ERR(bc))
  			break;
2c9ecdf40   FUJITA Tomonori   bsg: add bidi sup...
498
499
  		tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
  						bc->bidi_bio);
3d6392cfb   Jens Axboe   bsg: support for ...
500
501
502
503
504
505
506
507
  		if (!ret)
  			ret = tret;
  
  		bsg_free_command(bc);
  	} while (1);
  
  	return ret;
  }
25fd16430   Jens Axboe   bsg: address vari...
508
  static int
e7d721732   FUJITA Tomonori   bsg: fix a blocki...
509
510
  __bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
  	   const struct iovec *iov, ssize_t *bytes_read)
3d6392cfb   Jens Axboe   bsg: support for ...
511
512
513
  {
  	struct bsg_command *bc;
  	int nr_commands, ret;
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
514
  	if (count % sizeof(struct sg_io_v4))
3d6392cfb   Jens Axboe   bsg: support for ...
515
516
517
  		return -EINVAL;
  
  	ret = 0;
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
518
  	nr_commands = count / sizeof(struct sg_io_v4);
3d6392cfb   Jens Axboe   bsg: support for ...
519
  	while (nr_commands) {
e7d721732   FUJITA Tomonori   bsg: fix a blocki...
520
  		bc = bsg_get_done_cmd(bd);
3d6392cfb   Jens Axboe   bsg: support for ...
521
522
523
524
525
526
527
528
529
530
  		if (IS_ERR(bc)) {
  			ret = PTR_ERR(bc);
  			break;
  		}
  
  		/*
  		 * this is the only case where we need to copy data back
  		 * after completing the request. so do that here,
  		 * bsg_complete_work() cannot do that for us
  		 */
2c9ecdf40   FUJITA Tomonori   bsg: add bidi sup...
531
532
  		ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
  					       bc->bidi_bio);
3d6392cfb   Jens Axboe   bsg: support for ...
533

25fd16430   Jens Axboe   bsg: address vari...
534
  		if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
3d6392cfb   Jens Axboe   bsg: support for ...
535
536
537
538
539
540
  			ret = -EFAULT;
  
  		bsg_free_command(bc);
  
  		if (ret)
  			break;
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
541
542
  		buf += sizeof(struct sg_io_v4);
  		*bytes_read += sizeof(struct sg_io_v4);
3d6392cfb   Jens Axboe   bsg: support for ...
543
544
545
546
547
548
549
550
551
552
553
554
555
  		nr_commands--;
  	}
  
  	return ret;
  }
  
  static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
  {
  	if (file->f_flags & O_NONBLOCK)
  		clear_bit(BSG_F_BLOCK, &bd->flags);
  	else
  		set_bit(BSG_F_BLOCK, &bd->flags);
  }
25fd16430   Jens Axboe   bsg: address vari...
556
557
558
  /*
   * Check if the error is a "real" error that we should return.
   */
3d6392cfb   Jens Axboe   bsg: support for ...
559
560
561
562
563
564
565
566
567
568
569
570
571
572
  static inline int err_block_err(int ret)
  {
  	if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
  		return 1;
  
  	return 0;
  }
  
  static ssize_t
  bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
  {
  	struct bsg_device *bd = file->private_data;
  	int ret;
  	ssize_t bytes_read;
9e69fbb53   FUJITA Tomonori   bsg: minor cleanups
573
574
  	dprintk("%s: read %Zd bytes
  ", bd->name, count);
3d6392cfb   Jens Axboe   bsg: support for ...
575
576
  
  	bsg_set_block(bd, file);
0b07de85a   Adel Gadllah   allow userspace t...
577

3d6392cfb   Jens Axboe   bsg: support for ...
578
  	bytes_read = 0;
e7d721732   FUJITA Tomonori   bsg: fix a blocki...
579
  	ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
3d6392cfb   Jens Axboe   bsg: support for ...
580
  	*ppos = bytes_read;
44194e3e8   Namhyung Kim   bsg: remove unnec...
581
  	if (!bytes_read || err_block_err(ret))
3d6392cfb   Jens Axboe   bsg: support for ...
582
583
584
585
  		bytes_read = ret;
  
  	return bytes_read;
  }
25fd16430   Jens Axboe   bsg: address vari...
586
  static int __bsg_write(struct bsg_device *bd, const char __user *buf,
aeb5d7270   Al Viro   [PATCH] introduce...
587
588
  		       size_t count, ssize_t *bytes_written,
  		       fmode_t has_write_perm)
3d6392cfb   Jens Axboe   bsg: support for ...
589
590
591
592
  {
  	struct bsg_command *bc;
  	struct request *rq;
  	int ret, nr_commands;
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
593
  	if (count % sizeof(struct sg_io_v4))
3d6392cfb   Jens Axboe   bsg: support for ...
594
  		return -EINVAL;
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
595
  	nr_commands = count / sizeof(struct sg_io_v4);
3d6392cfb   Jens Axboe   bsg: support for ...
596
597
598
599
  	rq = NULL;
  	bc = NULL;
  	ret = 0;
  	while (nr_commands) {
165125e1e   Jens Axboe   [BLOCK] Get rid o...
600
  		struct request_queue *q = bd->queue;
3d6392cfb   Jens Axboe   bsg: support for ...
601

e7d721732   FUJITA Tomonori   bsg: fix a blocki...
602
  		bc = bsg_alloc_command(bd);
3d6392cfb   Jens Axboe   bsg: support for ...
603
604
605
606
607
  		if (IS_ERR(bc)) {
  			ret = PTR_ERR(bc);
  			bc = NULL;
  			break;
  		}
3d6392cfb   Jens Axboe   bsg: support for ...
608
609
610
611
612
613
614
615
  		if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
  			ret = -EFAULT;
  			break;
  		}
  
  		/*
  		 * get a request, fill in the blanks, and add to request queue
  		 */
c1c201200   Boaz Harrosh   bsg: Fix sense bu...
616
  		rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm, bc->sense);
3d6392cfb   Jens Axboe   bsg: support for ...
617
618
619
620
621
622
623
624
625
626
  		if (IS_ERR(rq)) {
  			ret = PTR_ERR(rq);
  			rq = NULL;
  			break;
  		}
  
  		bsg_add_command(bd, q, bc, rq);
  		bc = NULL;
  		rq = NULL;
  		nr_commands--;
70e36ecea   FUJITA Tomonori   bsg: replace SG v...
627
  		buf += sizeof(struct sg_io_v4);
25fd16430   Jens Axboe   bsg: address vari...
628
  		*bytes_written += sizeof(struct sg_io_v4);
3d6392cfb   Jens Axboe   bsg: support for ...
629
  	}
3d6392cfb   Jens Axboe   bsg: support for ...
630
631
632
633
634
635
636
637
638
639
  	if (bc)
  		bsg_free_command(bc);
  
  	return ret;
  }
  
  static ssize_t
  bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
  {
  	struct bsg_device *bd = file->private_data;
25fd16430   Jens Axboe   bsg: address vari...
640
  	ssize_t bytes_written;
3d6392cfb   Jens Axboe   bsg: support for ...
641
  	int ret;
9e69fbb53   FUJITA Tomonori   bsg: minor cleanups
642
643
  	dprintk("%s: write %Zd bytes
  ", bd->name, count);
3d6392cfb   Jens Axboe   bsg: support for ...
644
645
  
  	bsg_set_block(bd, file);
3d6392cfb   Jens Axboe   bsg: support for ...
646

25fd16430   Jens Axboe   bsg: address vari...
647
  	bytes_written = 0;
abf543937   FUJITA Tomonori   block: move cmdfi...
648
649
  	ret = __bsg_write(bd, buf, count, &bytes_written,
  			  file->f_mode & FMODE_WRITE);
25fd16430   Jens Axboe   bsg: address vari...
650
  	*ppos = bytes_written;
3d6392cfb   Jens Axboe   bsg: support for ...
651
652
653
654
  
  	/*
  	 * return bytes written on non-fatal errors
  	 */
44194e3e8   Namhyung Kim   bsg: remove unnec...
655
  	if (!bytes_written || err_block_err(ret))
25fd16430   Jens Axboe   bsg: address vari...
656
  		bytes_written = ret;
3d6392cfb   Jens Axboe   bsg: support for ...
657

25fd16430   Jens Axboe   bsg: address vari...
658
659
660
  	dprintk("%s: returning %Zd
  ", bd->name, bytes_written);
  	return bytes_written;
3d6392cfb   Jens Axboe   bsg: support for ...
661
  }
3d6392cfb   Jens Axboe   bsg: support for ...
662
663
  static struct bsg_device *bsg_alloc_device(void)
  {
3d6392cfb   Jens Axboe   bsg: support for ...
664
  	struct bsg_device *bd;
3d6392cfb   Jens Axboe   bsg: support for ...
665
666
667
668
669
670
  
  	bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
  	if (unlikely(!bd))
  		return NULL;
  
  	spin_lock_init(&bd->lock);
5309cb38d   Jens Axboe   Add queue resizin...
671
  	bd->max_queue = BSG_DEFAULT_CMDS;
3d6392cfb   Jens Axboe   bsg: support for ...
672
673
674
675
676
677
678
679
  
  	INIT_LIST_HEAD(&bd->busy_list);
  	INIT_LIST_HEAD(&bd->done_list);
  	INIT_HLIST_NODE(&bd->dev_list);
  
  	init_waitqueue_head(&bd->wq_free);
  	init_waitqueue_head(&bd->wq_done);
  	return bd;
3d6392cfb   Jens Axboe   bsg: support for ...
680
  }
97f46ae45   FUJITA Tomonori   [SCSI] bsg: add r...
681
682
683
684
  static void bsg_kref_release_function(struct kref *kref)
  {
  	struct bsg_class_device *bcd =
  		container_of(kref, struct bsg_class_device, ref);
8df5fc042   James Bottomley   [SCSI] bsg: fix o...
685
  	struct device *parent = bcd->parent;
97f46ae45   FUJITA Tomonori   [SCSI] bsg: add r...
686
687
688
  
  	if (bcd->release)
  		bcd->release(bcd->parent);
8df5fc042   James Bottomley   [SCSI] bsg: fix o...
689
  	put_device(parent);
97f46ae45   FUJITA Tomonori   [SCSI] bsg: add r...
690
  }
3d6392cfb   Jens Axboe   bsg: support for ...
691
692
  static int bsg_put_device(struct bsg_device *bd)
  {
97f46ae45   FUJITA Tomonori   [SCSI] bsg: add r...
693
694
  	int ret = 0, do_free;
  	struct request_queue *q = bd->queue;
3d6392cfb   Jens Axboe   bsg: support for ...
695
696
  
  	mutex_lock(&bsg_mutex);
97f46ae45   FUJITA Tomonori   [SCSI] bsg: add r...
697
  	do_free = atomic_dec_and_test(&bd->ref_count);
3f27e3ed1   FUJITA Tomonori   [SCSI] bsg: fix b...
698
699
  	if (!do_free) {
  		mutex_unlock(&bsg_mutex);
3d6392cfb   Jens Axboe   bsg: support for ...
700
  		goto out;
3f27e3ed1   FUJITA Tomonori   [SCSI] bsg: fix b...
701
702
703
704
  	}
  
  	hlist_del(&bd->dev_list);
  	mutex_unlock(&bsg_mutex);
3d6392cfb   Jens Axboe   bsg: support for ...
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
  
  	dprintk("%s: tearing down
  ", bd->name);
  
  	/*
  	 * close can always block
  	 */
  	set_bit(BSG_F_BLOCK, &bd->flags);
  
  	/*
  	 * correct error detection baddies here again. it's the responsibility
  	 * of the app to properly reap commands before close() if it wants
  	 * fool-proof error detection
  	 */
  	ret = bsg_complete_all_commands(bd);
5309cb38d   Jens Axboe   Add queue resizin...
720
  	kfree(bd);
3d6392cfb   Jens Axboe   bsg: support for ...
721
  out:
97f46ae45   FUJITA Tomonori   [SCSI] bsg: add r...
722
723
724
  	kref_put(&q->bsg_dev.ref, bsg_kref_release_function);
  	if (do_free)
  		blk_put_queue(q);
3d6392cfb   Jens Axboe   bsg: support for ...
725
726
727
728
  	return ret;
  }
  
  static struct bsg_device *bsg_add_device(struct inode *inode,
d351af01b   FUJITA Tomonori   bsg: bind bsg to ...
729
  					 struct request_queue *rq,
3d6392cfb   Jens Axboe   bsg: support for ...
730
731
  					 struct file *file)
  {
25fd16430   Jens Axboe   bsg: address vari...
732
  	struct bsg_device *bd;
c3ff1b90d   FUJITA Tomonori   [SCSI] bsg: repla...
733
  	int ret;
3d6392cfb   Jens Axboe   bsg: support for ...
734
735
736
  #ifdef BSG_DEBUG
  	unsigned char buf[32];
  #endif
c3ff1b90d   FUJITA Tomonori   [SCSI] bsg: repla...
737
738
739
  	ret = blk_get_queue(rq);
  	if (ret)
  		return ERR_PTR(-ENXIO);
3d6392cfb   Jens Axboe   bsg: support for ...
740
741
  
  	bd = bsg_alloc_device();
c3ff1b90d   FUJITA Tomonori   [SCSI] bsg: repla...
742
743
  	if (!bd) {
  		blk_put_queue(rq);
3d6392cfb   Jens Axboe   bsg: support for ...
744
  		return ERR_PTR(-ENOMEM);
c3ff1b90d   FUJITA Tomonori   [SCSI] bsg: repla...
745
  	}
3d6392cfb   Jens Axboe   bsg: support for ...
746

d351af01b   FUJITA Tomonori   bsg: bind bsg to ...
747
  	bd->queue = rq;
0b07de85a   Adel Gadllah   allow userspace t...
748

3d6392cfb   Jens Axboe   bsg: support for ...
749
750
751
  	bsg_set_block(bd, file);
  
  	atomic_set(&bd->ref_count, 1);
3d6392cfb   Jens Axboe   bsg: support for ...
752
  	mutex_lock(&bsg_mutex);
842ea771c   FUJITA Tomonori   [SCSI] bsg: remov...
753
  	hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
3d6392cfb   Jens Axboe   bsg: support for ...
754

3ada8b7e9   Kay Sievers   block: struct dev...
755
  	strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
3d6392cfb   Jens Axboe   bsg: support for ...
756
757
  	dprintk("bound to <%s>, max queue %d
  ",
9e69fbb53   FUJITA Tomonori   bsg: minor cleanups
758
  		format_dev_t(buf, inode->i_rdev), bd->max_queue);
3d6392cfb   Jens Axboe   bsg: support for ...
759
760
761
762
  
  	mutex_unlock(&bsg_mutex);
  	return bd;
  }
842ea771c   FUJITA Tomonori   [SCSI] bsg: remov...
763
  static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
3d6392cfb   Jens Axboe   bsg: support for ...
764
  {
43ac9e62c   FUJITA Tomonori   [SCSI] bsg: use b...
765
  	struct bsg_device *bd;
3d6392cfb   Jens Axboe   bsg: support for ...
766
767
768
  	struct hlist_node *entry;
  
  	mutex_lock(&bsg_mutex);
43ac9e62c   FUJITA Tomonori   [SCSI] bsg: use b...
769
  	hlist_for_each_entry(bd, entry, bsg_dev_idx_hash(minor), dev_list) {
842ea771c   FUJITA Tomonori   [SCSI] bsg: remov...
770
  		if (bd->queue == q) {
3d6392cfb   Jens Axboe   bsg: support for ...
771
  			atomic_inc(&bd->ref_count);
43ac9e62c   FUJITA Tomonori   [SCSI] bsg: use b...
772
  			goto found;
3d6392cfb   Jens Axboe   bsg: support for ...
773
  		}
3d6392cfb   Jens Axboe   bsg: support for ...
774
  	}
43ac9e62c   FUJITA Tomonori   [SCSI] bsg: use b...
775
776
  	bd = NULL;
  found:
3d6392cfb   Jens Axboe   bsg: support for ...
777
778
779
780
781
782
  	mutex_unlock(&bsg_mutex);
  	return bd;
  }
  
  static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
  {
598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
783
784
  	struct bsg_device *bd;
  	struct bsg_class_device *bcd;
3d6392cfb   Jens Axboe   bsg: support for ...
785

3d6392cfb   Jens Axboe   bsg: support for ...
786
787
788
  	/*
  	 * find the class device
  	 */
3d6392cfb   Jens Axboe   bsg: support for ...
789
  	mutex_lock(&bsg_mutex);
598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
790
  	bcd = idr_find(&bsg_minor_idr, iminor(inode));
d45ac4fa8   FUJITA Tomonori   [SCSI] bsg: takes...
791
  	if (bcd)
97f46ae45   FUJITA Tomonori   [SCSI] bsg: add r...
792
  		kref_get(&bcd->ref);
3d6392cfb   Jens Axboe   bsg: support for ...
793
794
795
796
  	mutex_unlock(&bsg_mutex);
  
  	if (!bcd)
  		return ERR_PTR(-ENODEV);
842ea771c   FUJITA Tomonori   [SCSI] bsg: remov...
797
  	bd = __bsg_get_device(iminor(inode), bcd->queue);
d45ac4fa8   FUJITA Tomonori   [SCSI] bsg: takes...
798
799
800
801
802
  	if (bd)
  		return bd;
  
  	bd = bsg_add_device(inode, bcd->queue, file);
  	if (IS_ERR(bd))
97f46ae45   FUJITA Tomonori   [SCSI] bsg: add r...
803
  		kref_put(&bcd->ref, bsg_kref_release_function);
d45ac4fa8   FUJITA Tomonori   [SCSI] bsg: takes...
804
805
  
  	return bd;
3d6392cfb   Jens Axboe   bsg: support for ...
806
807
808
809
  }
  
  static int bsg_open(struct inode *inode, struct file *file)
  {
75bd2ef14   Jonathan Corbet   bsg: cdev lock_ke...
810
  	struct bsg_device *bd;
75bd2ef14   Jonathan Corbet   bsg: cdev lock_ke...
811
  	bd = bsg_get_device(inode, file);
3d6392cfb   Jens Axboe   bsg: support for ...
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
  
  	if (IS_ERR(bd))
  		return PTR_ERR(bd);
  
  	file->private_data = bd;
  	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);
  }
  
  static unsigned int bsg_poll(struct file *file, poll_table *wait)
  {
  	struct bsg_device *bd = file->private_data;
  	unsigned int mask = 0;
  
  	poll_wait(file, &bd->wq_done, wait);
  	poll_wait(file, &bd->wq_free, wait);
  
  	spin_lock_irq(&bd->lock);
  	if (!list_empty(&bd->done_list))
  		mask |= POLLIN | POLLRDNORM;
80ceb0571   Namhyung Kim   bsg: fix bsg_poll...
839
  	if (bd->queued_cmds < bd->max_queue)
3d6392cfb   Jens Axboe   bsg: support for ...
840
841
842
843
844
  		mask |= POLLOUT;
  	spin_unlock_irq(&bd->lock);
  
  	return mask;
  }
25fd16430   Jens Axboe   bsg: address vari...
845
  static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3d6392cfb   Jens Axboe   bsg: support for ...
846
847
848
  {
  	struct bsg_device *bd = file->private_data;
  	int __user *uarg = (int __user *) arg;
2d507a01d   James Bottomley   [SCSI] libsas, bs...
849
  	int ret;
3d6392cfb   Jens Axboe   bsg: support for ...
850

3d6392cfb   Jens Axboe   bsg: support for ...
851
852
853
854
855
856
  	switch (cmd) {
  		/*
  		 * our own ioctls
  		 */
  	case SG_GET_COMMAND_Q:
  		return put_user(bd->max_queue, uarg);
5309cb38d   Jens Axboe   Add queue resizin...
857
  	case SG_SET_COMMAND_Q: {
3d6392cfb   Jens Axboe   bsg: support for ...
858
859
860
861
  		int queue;
  
  		if (get_user(queue, uarg))
  			return -EFAULT;
5309cb38d   Jens Axboe   Add queue resizin...
862
  		if (queue < 1)
3d6392cfb   Jens Axboe   bsg: support for ...
863
  			return -EINVAL;
5309cb38d   Jens Axboe   Add queue resizin...
864
  		spin_lock_irq(&bd->lock);
3d6392cfb   Jens Axboe   bsg: support for ...
865
  		bd->max_queue = queue;
5309cb38d   Jens Axboe   Add queue resizin...
866
  		spin_unlock_irq(&bd->lock);
3d6392cfb   Jens Axboe   bsg: support for ...
867
868
869
870
871
872
873
874
875
876
877
878
879
880
  		return 0;
  	}
  
  	/*
  	 * SCSI/sg ioctls
  	 */
  	case SG_GET_VERSION_NUM:
  	case SCSI_IOCTL_GET_IDLUN:
  	case SCSI_IOCTL_GET_BUS_NUMBER:
  	case SG_SET_TIMEOUT:
  	case SG_GET_TIMEOUT:
  	case SG_GET_RESERVED_SIZE:
  	case SG_SET_RESERVED_SIZE:
  	case SG_EMULATED_HOST:
3d6392cfb   Jens Axboe   bsg: support for ...
881
882
  	case SCSI_IOCTL_SEND_COMMAND: {
  		void __user *uarg = (void __user *) arg;
74f3c8aff   Al Viro   [PATCH] switch sc...
883
  		return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
3d6392cfb   Jens Axboe   bsg: support for ...
884
  	}
10e8855b9   FUJITA Tomonori   bsg: add SG_IO to...
885
886
  	case SG_IO: {
  		struct request *rq;
2c9ecdf40   FUJITA Tomonori   bsg: add bidi sup...
887
  		struct bio *bio, *bidi_bio = NULL;
10e8855b9   FUJITA Tomonori   bsg: add SG_IO to...
888
  		struct sg_io_v4 hdr;
05378940c   Boaz Harrosh   bsg: add support ...
889
  		int at_head;
c1c201200   Boaz Harrosh   bsg: Fix sense bu...
890
  		u8 sense[SCSI_SENSE_BUFFERSIZE];
10e8855b9   FUJITA Tomonori   bsg: add SG_IO to...
891
892
893
  
  		if (copy_from_user(&hdr, uarg, sizeof(hdr)))
  			return -EFAULT;
c1c201200   Boaz Harrosh   bsg: Fix sense bu...
894
  		rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE, sense);
10e8855b9   FUJITA Tomonori   bsg: add SG_IO to...
895
896
897
898
  		if (IS_ERR(rq))
  			return PTR_ERR(rq);
  
  		bio = rq->bio;
2c9ecdf40   FUJITA Tomonori   bsg: add bidi sup...
899
900
  		if (rq->next_rq)
  			bidi_bio = rq->next_rq->bio;
05378940c   Boaz Harrosh   bsg: add support ...
901
902
903
  
  		at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
  		blk_execute_rq(bd->queue, NULL, rq, at_head);
2d507a01d   James Bottomley   [SCSI] libsas, bs...
904
  		ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
10e8855b9   FUJITA Tomonori   bsg: add SG_IO to...
905
906
907
  
  		if (copy_to_user(uarg, &hdr, sizeof(hdr)))
  			return -EFAULT;
b711afa69   Jens Axboe   bsg: style cleanup
908

2d507a01d   James Bottomley   [SCSI] libsas, bs...
909
  		return ret;
10e8855b9   FUJITA Tomonori   bsg: add SG_IO to...
910
  	}
3d6392cfb   Jens Axboe   bsg: support for ...
911
912
913
914
915
916
917
918
919
920
921
  	/*
  	 * block device ioctls
  	 */
  	default:
  #if 0
  		return ioctl_by_bdev(bd->bdev, cmd, arg);
  #else
  		return -ENOTTY;
  #endif
  	}
  }
7344be053   Arjan van de Ven   bsg: mark struct ...
922
  static const struct file_operations bsg_fops = {
3d6392cfb   Jens Axboe   bsg: support for ...
923
924
925
926
927
  	.read		=	bsg_read,
  	.write		=	bsg_write,
  	.poll		=	bsg_poll,
  	.open		=	bsg_open,
  	.release	=	bsg_release,
25fd16430   Jens Axboe   bsg: address vari...
928
  	.unlocked_ioctl	=	bsg_ioctl,
3d6392cfb   Jens Axboe   bsg: support for ...
929
  	.owner		=	THIS_MODULE,
6038f373a   Arnd Bergmann   llseek: automatic...
930
  	.llseek		=	default_llseek,
3d6392cfb   Jens Axboe   bsg: support for ...
931
  };
d351af01b   FUJITA Tomonori   bsg: bind bsg to ...
932
  void bsg_unregister_queue(struct request_queue *q)
3d6392cfb   Jens Axboe   bsg: support for ...
933
  {
d351af01b   FUJITA Tomonori   bsg: bind bsg to ...
934
  	struct bsg_class_device *bcd = &q->bsg_dev;
3d6392cfb   Jens Axboe   bsg: support for ...
935

df468820b   FUJITA Tomonori   [SCSI] bsg: fix b...
936
937
  	if (!bcd->class_dev)
  		return;
3d6392cfb   Jens Axboe   bsg: support for ...
938
939
  
  	mutex_lock(&bsg_mutex);
598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
940
  	idr_remove(&bsg_minor_idr, bcd->minor);
d351af01b   FUJITA Tomonori   bsg: bind bsg to ...
941
  	sysfs_remove_link(&q->kobj, "bsg");
ee959b00c   Tony Jones   SCSI: convert str...
942
  	device_unregister(bcd->class_dev);
3d6392cfb   Jens Axboe   bsg: support for ...
943
  	bcd->class_dev = NULL;
97f46ae45   FUJITA Tomonori   [SCSI] bsg: add r...
944
  	kref_put(&bcd->ref, bsg_kref_release_function);
3d6392cfb   Jens Axboe   bsg: support for ...
945
946
  	mutex_unlock(&bsg_mutex);
  }
4cf0723ac   FUJITA Tomonori   bsg: minor bug fixes
947
  EXPORT_SYMBOL_GPL(bsg_unregister_queue);
3d6392cfb   Jens Axboe   bsg: support for ...
948

97f46ae45   FUJITA Tomonori   [SCSI] bsg: add r...
949
950
  int bsg_register_queue(struct request_queue *q, struct device *parent,
  		       const char *name, void (*release)(struct device *))
3d6392cfb   Jens Axboe   bsg: support for ...
951
  {
598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
952
  	struct bsg_class_device *bcd;
3d6392cfb   Jens Axboe   bsg: support for ...
953
  	dev_t dev;
598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
954
  	int ret, minor;
ee959b00c   Tony Jones   SCSI: convert str...
955
  	struct device *class_dev = NULL;
39dca558a   James Bottomley   [SCSI] bsg: make ...
956
957
958
959
960
  	const char *devname;
  
  	if (name)
  		devname = name;
  	else
3ada8b7e9   Kay Sievers   block: struct dev...
961
  		devname = dev_name(parent);
3d6392cfb   Jens Axboe   bsg: support for ...
962
963
964
965
966
967
  
  	/*
  	 * we need a proper transport to send commands, not a stacked device
  	 */
  	if (!q->request_fn)
  		return 0;
d351af01b   FUJITA Tomonori   bsg: bind bsg to ...
968
  	bcd = &q->bsg_dev;
3d6392cfb   Jens Axboe   bsg: support for ...
969
  	memset(bcd, 0, sizeof(*bcd));
3d6392cfb   Jens Axboe   bsg: support for ...
970
971
  
  	mutex_lock(&bsg_mutex);
292b7f271   FUJITA Tomonori   improve bsg devic...
972

598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
973
974
975
976
  	ret = idr_pre_get(&bsg_minor_idr, GFP_KERNEL);
  	if (!ret) {
  		ret = -ENOMEM;
  		goto unlock;
292b7f271   FUJITA Tomonori   improve bsg devic...
977
  	}
598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
978
979
980
  	ret = idr_get_new(&bsg_minor_idr, bcd, &minor);
  	if (ret < 0)
  		goto unlock;
292b7f271   FUJITA Tomonori   improve bsg devic...
981

598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
982
983
984
985
986
987
988
989
  	if (minor >= BSG_MAX_DEVS) {
  		printk(KERN_ERR "bsg: too many bsg devices
  ");
  		ret = -EINVAL;
  		goto remove_idr;
  	}
  
  	bcd->minor = minor;
d351af01b   FUJITA Tomonori   bsg: bind bsg to ...
990
  	bcd->queue = q;
97f46ae45   FUJITA Tomonori   [SCSI] bsg: add r...
991
992
993
  	bcd->parent = get_device(parent);
  	bcd->release = release;
  	kref_init(&bcd->ref);
46f6ef4af   Jens Axboe   bsg: convert to d...
994
  	dev = MKDEV(bsg_major, bcd->minor);
1ff9f542e   Greg Kroah-Hartman   device create: bl...
995
  	class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname);
4e2872d6b   FUJITA Tomonori   bind bsg to all S...
996
997
  	if (IS_ERR(class_dev)) {
  		ret = PTR_ERR(class_dev);
598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
998
  		goto put_dev;
4e2872d6b   FUJITA Tomonori   bind bsg to all S...
999
1000
  	}
  	bcd->class_dev = class_dev;
abce891a1   Linus Torvalds   Fix new generic b...
1001
  	if (q->kobj.sd) {
4e2872d6b   FUJITA Tomonori   bind bsg to all S...
1002
1003
  		ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
  		if (ret)
598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
1004
  			goto unregister_class_dev;
4e2872d6b   FUJITA Tomonori   bind bsg to all S...
1005
  	}
3d6392cfb   Jens Axboe   bsg: support for ...
1006
1007
  	mutex_unlock(&bsg_mutex);
  	return 0;
6826ee4fd   James Bottomley   [SCSI] bsg: fix b...
1008

598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
1009
  unregister_class_dev:
ee959b00c   Tony Jones   SCSI: convert str...
1010
  	device_unregister(class_dev);
598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
1011
  put_dev:
97f46ae45   FUJITA Tomonori   [SCSI] bsg: add r...
1012
  	put_device(parent);
598443a21   FUJITA Tomonori   [SCSI] bsg: use l...
1013
1014
1015
  remove_idr:
  	idr_remove(&bsg_minor_idr, minor);
  unlock:
264a04721   Jens Axboe   bsg: add cheasy e...
1016
  	mutex_unlock(&bsg_mutex);
4e2872d6b   FUJITA Tomonori   bind bsg to all S...
1017
1018
  	return ret;
  }
4cf0723ac   FUJITA Tomonori   bsg: minor bug fixes
1019
  EXPORT_SYMBOL_GPL(bsg_register_queue);
4e2872d6b   FUJITA Tomonori   bind bsg to all S...
1020

7e7654a92   Greg Kroah-Hartman   cdev: remove unne...
1021
  static struct cdev bsg_cdev;
292b7f271   FUJITA Tomonori   improve bsg devic...
1022

e454cea20   Kay Sievers   Driver-Core: exte...
1023
  static char *bsg_devnode(struct device *dev, mode_t *mode)
2bdf91491   Kay Sievers   Driver Core: bsg:...
1024
1025
1026
  {
  	return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
  }
3d6392cfb   Jens Axboe   bsg: support for ...
1027
1028
1029
  static int __init bsg_init(void)
  {
  	int ret, i;
46f6ef4af   Jens Axboe   bsg: convert to d...
1030
  	dev_t devid;
3d6392cfb   Jens Axboe   bsg: support for ...
1031

5309cb38d   Jens Axboe   Add queue resizin...
1032
  	bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
20c2df83d   Paul Mundt   mm: Remove slab d...
1033
  				sizeof(struct bsg_command), 0, 0, NULL);
5309cb38d   Jens Axboe   Add queue resizin...
1034
1035
1036
1037
1038
  	if (!bsg_cmd_cachep) {
  		printk(KERN_ERR "bsg: failed creating slab cache
  ");
  		return -ENOMEM;
  	}
25fd16430   Jens Axboe   bsg: address vari...
1039
  	for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
3d6392cfb   Jens Axboe   bsg: support for ...
1040
1041
1042
  		INIT_HLIST_HEAD(&bsg_device_list[i]);
  
  	bsg_class = class_create(THIS_MODULE, "bsg");
5309cb38d   Jens Axboe   Add queue resizin...
1043
  	if (IS_ERR(bsg_class)) {
9b9f770ce   FUJITA Tomonori   bsg: fix initiali...
1044
1045
  		ret = PTR_ERR(bsg_class);
  		goto destroy_kmemcache;
5309cb38d   Jens Axboe   Add queue resizin...
1046
  	}
e454cea20   Kay Sievers   Driver-Core: exte...
1047
  	bsg_class->devnode = bsg_devnode;
3d6392cfb   Jens Axboe   bsg: support for ...
1048

46f6ef4af   Jens Axboe   bsg: convert to d...
1049
  	ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
9b9f770ce   FUJITA Tomonori   bsg: fix initiali...
1050
1051
  	if (ret)
  		goto destroy_bsg_class;
292b7f271   FUJITA Tomonori   improve bsg devic...
1052

46f6ef4af   Jens Axboe   bsg: convert to d...
1053
  	bsg_major = MAJOR(devid);
292b7f271   FUJITA Tomonori   improve bsg devic...
1054
  	cdev_init(&bsg_cdev, &bsg_fops);
46f6ef4af   Jens Axboe   bsg: convert to d...
1055
  	ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
9b9f770ce   FUJITA Tomonori   bsg: fix initiali...
1056
1057
  	if (ret)
  		goto unregister_chrdev;
3d6392cfb   Jens Axboe   bsg: support for ...
1058

5d3a8cd34   Jens Axboe   bsg: fix missing ...
1059
  	printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
0ed081ce2   FUJITA Tomonori   bsg: minor cleanup
1060
1061
  	       " loaded (major %d)
  ", bsg_major);
3d6392cfb   Jens Axboe   bsg: support for ...
1062
  	return 0;
9b9f770ce   FUJITA Tomonori   bsg: fix initiali...
1063
1064
1065
1066
1067
1068
1069
  unregister_chrdev:
  	unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
  destroy_bsg_class:
  	class_destroy(bsg_class);
  destroy_kmemcache:
  	kmem_cache_destroy(bsg_cmd_cachep);
  	return ret;
3d6392cfb   Jens Axboe   bsg: support for ...
1070
1071
1072
  }
  
  MODULE_AUTHOR("Jens Axboe");
0ed081ce2   FUJITA Tomonori   bsg: minor cleanup
1073
  MODULE_DESCRIPTION(BSG_DESCRIPTION);
3d6392cfb   Jens Axboe   bsg: support for ...
1074
  MODULE_LICENSE("GPL");
4e2872d6b   FUJITA Tomonori   bind bsg to all S...
1075
  device_initcall(bsg_init);