1 files changed, 6 insertions, 454 deletions

diff --git a/block/bsg.c b/block/bsg.c
index 3da540faf673..db588add6ba6 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -13,11 +13,9 @@
 #include <linux/init.h>
 #include <linux/file.h>
 #include <linux/blkdev.h>
-#include <linux/poll.h>
 #include <linux/cdev.h>
 #include <linux/jiffies.h>
 #include <linux/percpu.h>
-#include <linux/uio.h>
 #include <linux/idr.h>
 #include <linux/bsg.h>
 #include <linux/slab.h>
@@ -38,21 +36,10 @@
 struct bsg_device {
 	struct request_queue *queue;
 	spinlock_t lock;
-	struct list_head busy_list;
-	struct list_head done_list;
 	struct hlist_node dev_list;
 	atomic_t ref_count;
-	int queued_cmds;
-	int done_cmds;
-	wait_queue_head_t wq_done;
-	wait_queue_head_t wq_free;
 	char name[20];
 	int max_queue;
-	unsigned long flags;
-};
-
-enum {
-	BSG_F_BLOCK		= 1,
 };
 
 #define BSG_DEFAULT_CMDS	64
@@ -67,64 +54,6 @@ static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
 static struct class *bsg_class;
 static int bsg_major;
 
-static struct kmem_cache *bsg_cmd_cachep;
-
-/*
- * our internal command type
- */
-struct bsg_command {
-	struct bsg_device *bd;
-	struct list_head list;
-	struct request *rq;
-	struct bio *bio;
-	struct bio *bidi_bio;
-	int err;
-	struct sg_io_v4 hdr;
-};
-
-static void bsg_free_command(struct bsg_command *bc)
-{
-	struct bsg_device *bd = bc->bd;
-	unsigned long flags;
-
-	kmem_cache_free(bsg_cmd_cachep, bc);
-
-	spin_lock_irqsave(&bd->lock, flags);
-	bd->queued_cmds--;
-	spin_unlock_irqrestore(&bd->lock, flags);
-
-	wake_up(&bd->wq_free);
-}
-
-static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
-{
-	struct bsg_command *bc = ERR_PTR(-EINVAL);
-
-	spin_lock_irq(&bd->lock);
-
-	if (bd->queued_cmds >= bd->max_queue)
-		goto out;
-
-	bd->queued_cmds++;
-	spin_unlock_irq(&bd->lock);
-
-	bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
-	if (unlikely(!bc)) {
-		spin_lock_irq(&bd->lock);
-		bd->queued_cmds--;
-		bc = ERR_PTR(-ENOMEM);
-		goto out;
-	}
-
-	bc->bd = bd;
-	INIT_LIST_HEAD(&bc->list);
-	bsg_dbg(bd, "returning free cmd %p\n", bc);
-	return bc;
-out:
-	spin_unlock_irq(&bd->lock);
-	return bc;
-}
-
 static inline struct hlist_head *bsg_dev_idx_hash(int index)
 {
 	return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
@@ -285,101 +214,6 @@ out:
 	return ERR_PTR(ret);
 }
 
-/*
- * 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, blk_status_t status)
-{
-	struct bsg_command *bc = rq->end_io_data;
-	struct bsg_device *bd = bc->bd;
-	unsigned long flags;
-
-	bsg_dbg(bd, "finished rq %p bc %p, bio %p\n",
-		rq, bc, bc->bio);
-
-	bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
-
-	spin_lock_irqsave(&bd->lock, flags);
-	list_move_tail(&bc->list, &bd->done_list);
-	bd->done_cmds++;
-	spin_unlock_irqrestore(&bd->lock, flags);
-
-	wake_up(&bd->wq_done);
-}
-
-/*
- * do final setup of a 'bc' and submit the matching 'rq' to the block
- * layer for io
- */
-static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
-			    struct bsg_command *bc, struct request *rq)
-{
-	int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
-
-	/*
-	 * add bc command to busy queue and submit rq for io
-	 */
-	bc->rq = rq;
-	bc->bio = rq->bio;
-	if (rq->next_rq)
-		bc->bidi_bio = rq->next_rq->bio;
-	bc->hdr.duration = jiffies;
-	spin_lock_irq(&bd->lock);
-	list_add_tail(&bc->list, &bd->busy_list);
-	spin_unlock_irq(&bd->lock);
-
-	bsg_dbg(bd, "queueing rq %p, bc %p\n", rq, bc);
-
-	rq->end_io_data = bc;
-	blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
-}
-
-static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
-{
-	struct bsg_command *bc = NULL;
-
-	spin_lock_irq(&bd->lock);
-	if (bd->done_cmds) {
-		bc = list_first_entry(&bd->done_list, struct bsg_command, list);
-		list_del(&bc->list);
-		bd->done_cmds--;
-	}
-	spin_unlock_irq(&bd->lock);
-
-	return bc;
-}
-
-/*
- * Get a finished command from the done list
- */
-static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
-{
-	struct bsg_command *bc;
-	int ret;
-
-	do {
-		bc = bsg_next_done_cmd(bd);
-		if (bc)
-			break;
-
-		if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
-			bc = ERR_PTR(-EAGAIN);
-			break;
-		}
-
-		ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
-		if (ret) {
-			bc = ERR_PTR(-ERESTARTSYS);
-			break;
-		}
-	} while (1);
-
-	bsg_dbg(bd, "returning done %p\n", bc);
-
-	return bc;
-}
-
 static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
 				    struct bio *bio, struct bio *bidi_bio)
 {
@@ -398,234 +232,6 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
 	return ret;
 }
 
-static bool bsg_complete(struct bsg_device *bd)
-{
-	bool ret = false;
-	bool spin;
-
-	do {
-		spin_lock_irq(&bd->lock);
-
-		BUG_ON(bd->done_cmds > bd->queued_cmds);
-
-		/*
-		 * All commands consumed.
-		 */
-		if (bd->done_cmds == bd->queued_cmds)
-			ret = true;
-
-		spin = !test_bit(BSG_F_BLOCK, &bd->flags);
-
-		spin_unlock_irq(&bd->lock);
-	} while (!ret && spin);
-
-	return ret;
-}
-
-static int bsg_complete_all_commands(struct bsg_device *bd)
-{
-	struct bsg_command *bc;
-	int ret, tret;
-
-	bsg_dbg(bd, "entered\n");
-
-	/*
-	 * wait for all commands to complete
-	 */
-	io_wait_event(bd->wq_done, bsg_complete(bd));
-
-	/*
-	 * discard done commands
-	 */
-	ret = 0;
-	do {
-		spin_lock_irq(&bd->lock);
-		if (!bd->queued_cmds) {
-			spin_unlock_irq(&bd->lock);
-			break;
-		}
-		spin_unlock_irq(&bd->lock);
-
-		bc = bsg_get_done_cmd(bd);
-		if (IS_ERR(bc))
-			break;
-
-		tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
-						bc->bidi_bio);
-		if (!ret)
-			ret = tret;
-
-		bsg_free_command(bc);
-	} while (1);
-
-	return ret;
-}
-
-static int
-__bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
-	   const struct iovec *iov, ssize_t *bytes_read)
-{
-	struct bsg_command *bc;
-	int nr_commands, ret;
-
-	if (count % sizeof(struct sg_io_v4))
-		return -EINVAL;
-
-	ret = 0;
-	nr_commands = count / sizeof(struct sg_io_v4);
-	while (nr_commands) {
-		bc = bsg_get_done_cmd(bd);
-		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
-		 */
-		ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
-					       bc->bidi_bio);
-
-		if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
-			ret = -EFAULT;
-
-		bsg_free_command(bc);
-
-		if (ret)
-			break;
-
-		buf += sizeof(struct sg_io_v4);
-		*bytes_read += sizeof(struct sg_io_v4);
-		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);
-}
-
-/*
- * Check if the error is a "real" error that we should return.
- */
-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;
-
-	bsg_dbg(bd, "read %zd bytes\n", count);
-
-	bsg_set_block(bd, file);
-
-	bytes_read = 0;
-	ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
-	*ppos = bytes_read;
-
-	if (!bytes_read || err_block_err(ret))
-		bytes_read = ret;
-
-	return bytes_read;
-}
-
-static int __bsg_write(struct bsg_device *bd, const char __user *buf,
-		       size_t count, ssize_t *bytes_written, fmode_t mode)
-{
-	struct bsg_command *bc;
-	struct request *rq;
-	int ret, nr_commands;
-
-	if (count % sizeof(struct sg_io_v4))
-		return -EINVAL;
-
-	nr_commands = count / sizeof(struct sg_io_v4);
-	rq = NULL;
-	bc = NULL;
-	ret = 0;
-	while (nr_commands) {
-		struct request_queue *q = bd->queue;
-
-		bc = bsg_alloc_command(bd);
-		if (IS_ERR(bc)) {
-			ret = PTR_ERR(bc);
-			bc = NULL;
-			break;
-		}
-
-		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
-		 */
-		rq = bsg_map_hdr(bd->queue, &bc->hdr, mode);
-		if (IS_ERR(rq)) {
-			ret = PTR_ERR(rq);
-			rq = NULL;
-			break;
-		}
-
-		bsg_add_command(bd, q, bc, rq);
-		bc = NULL;
-		rq = NULL;
-		nr_commands--;
-		buf += sizeof(struct sg_io_v4);
-		*bytes_written += sizeof(struct sg_io_v4);
-	}
-
-	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;
-	ssize_t bytes_written;
-	int ret;
-
-	bsg_dbg(bd, "write %zd bytes\n", count);
-
-	if (unlikely(uaccess_kernel()))
-		return -EINVAL;
-
-	bsg_set_block(bd, file);
-
-	bytes_written = 0;
-	ret = __bsg_write(bd, buf, count, &bytes_written, file->f_mode);
-
-	*ppos = bytes_written;
-
-	/*
-	 * return bytes written on non-fatal errors
-	 */
-	if (!bytes_written || err_block_err(ret))
-		bytes_written = ret;
-
-	bsg_dbg(bd, "returning %zd\n", bytes_written);
-	return bytes_written;
-}
-
 static struct bsg_device *bsg_alloc_device(void)
 {
 	struct bsg_device *bd;
@@ -635,29 +241,20 @@ static struct bsg_device *bsg_alloc_device(void)
 		return NULL;
 
 	spin_lock_init(&bd->lock);
-
 	bd->max_queue = BSG_DEFAULT_CMDS;
-
-	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;
 }
 
 static int bsg_put_device(struct bsg_device *bd)
 {
-	int ret = 0, do_free;
 	struct request_queue *q = bd->queue;
 
 	mutex_lock(&bsg_mutex);
 
-	do_free = atomic_dec_and_test(&bd->ref_count);
-	if (!do_free) {
+	if (!atomic_dec_and_test(&bd->ref_count)) {
 		mutex_unlock(&bsg_mutex);
-		goto out;
+		return 0;
 	}
 
 	hlist_del(&bd->dev_list);
@@ -668,20 +265,9 @@ static int bsg_put_device(struct bsg_device *bd)
 	/*
 	 * 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);
-
 	kfree(bd);
-out:
-	if (do_free)
-		blk_put_queue(q);
-	return ret;
+	blk_put_queue(q);
+	return 0;
 }
 
 static struct bsg_device *bsg_add_device(struct inode *inode,
@@ -704,8 +290,6 @@ static struct bsg_device *bsg_add_device(struct inode *inode,
 
 	bd->queue = rq;
 
-	bsg_set_block(bd, file);
-
 	atomic_set(&bd->ref_count, 1);
 	hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
 
@@ -779,24 +363,6 @@ static int bsg_release(struct inode *inode, struct file *file)
 	return bsg_put_device(bd);
 }
 
-static __poll_t bsg_poll(struct file *file, poll_table *wait)
-{
-	struct bsg_device *bd = file->private_data;
-	__poll_t 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 |= EPOLLIN | EPOLLRDNORM;
-	if (bd->queued_cmds < bd->max_queue)
-		mask |= EPOLLOUT;
-	spin_unlock_irq(&bd->lock);
-
-	return mask;
-}
-
 static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct bsg_device *bd = file->private_data;
@@ -870,9 +436,6 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 }
 
 static const struct file_operations bsg_fops = {
-	.read		=	bsg_read,
-	.write		=	bsg_write,
-	.poll		=	bsg_poll,
 	.open		=	bsg_open,
 	.release	=	bsg_release,
 	.unlocked_ioctl	=	bsg_ioctl,
@@ -977,21 +540,12 @@ static int __init bsg_init(void)
 	int ret, i;
 	dev_t devid;
 
-	bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
-				sizeof(struct bsg_command), 0, 0, NULL);
-	if (!bsg_cmd_cachep) {
-		printk(KERN_ERR "bsg: failed creating slab cache\n");
-		return -ENOMEM;
-	}
-
 	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)) {
-		ret = PTR_ERR(bsg_class);
-		goto destroy_kmemcache;
-	}
+	if (IS_ERR(bsg_class))
+		return PTR_ERR(bsg_class);
 	bsg_class->devnode = bsg_devnode;
 
 	ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
@@ -1012,8 +566,6 @@ 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;
 }