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Commit 25fd1643 authored by Jens Axboe's avatar Jens Axboe
Browse files

bsg: address various review comments



This address most of the comments made by Andrew. The two remaining
are conversion to idr, and dynamic major.

Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent a5fcaa21
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+44 −58
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@
#include <scsi/scsi_driver.h>
#include <scsi/sg.h>

static char bsg_version[] = "block layer sg (bsg) 0.4";
const static char bsg_version[] = "block layer sg (bsg) 0.4";

struct bsg_device {
	request_queue_t *queue;
@@ -68,8 +68,6 @@ enum {
#define dprintk(fmt, args...)
#endif

#define list_entry_bc(entry)	list_entry((entry), struct bsg_command, list)

/*
 * just for testing
 */
@@ -78,9 +76,9 @@ enum {
static DEFINE_MUTEX(bsg_mutex);
static int bsg_device_nr, bsg_minor_idx;

#define BSG_LIST_SIZE	(8)
#define bsg_list_idx(minor)	((minor) & (BSG_LIST_SIZE - 1))
static struct hlist_head bsg_device_list[BSG_LIST_SIZE];
#define BSG_LIST_ARRAY_SIZE	8
#define bsg_list_idx(minor)	((minor) & (BSG_LIST_ARRAY_SIZE - 1))
static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];

static struct class *bsg_class;
static LIST_HEAD(bsg_class_list);
@@ -128,7 +126,7 @@ static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
	bd->queued_cmds++;
	spin_unlock_irq(&bd->lock);

	bc = kmem_cache_alloc(bsg_cmd_cachep, GFP_USER);
	bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
	if (unlikely(!bc)) {
		spin_lock_irq(&bd->lock);
		bd->queued_cmds--;
@@ -136,7 +134,6 @@ static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
		goto out;
	}

	memset(bc, 0, sizeof(*bc));
	bc->bd = bd;
	INIT_LIST_HEAD(&bc->list);
	dprintk("%s: returning free cmd %p\n", bd->name, bc);
@@ -146,22 +143,12 @@ out:
	return bc;
}

static inline void
bsg_del_done_cmd(struct bsg_device *bd, struct bsg_command *bc)
{
	bd->done_cmds--;
	list_del(&bc->list);
}

static inline void
bsg_add_done_cmd(struct bsg_device *bd, struct bsg_command *bc)
{
	bd->done_cmds++;
	list_add_tail(&bc->list, &bd->done_list);
	wake_up(&bd->wq_done);
}

static inline int bsg_io_schedule(struct bsg_device *bd, int state)
static int bsg_io_schedule(struct bsg_device *bd)
{
	DEFINE_WAIT(wait);
	int ret = 0;
@@ -186,14 +173,11 @@ static inline int bsg_io_schedule(struct bsg_device *bd, int state)
		goto unlock;
	}

	prepare_to_wait(&bd->wq_done, &wait, state);
	prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE);
	spin_unlock_irq(&bd->lock);
	io_schedule();
	finish_wait(&bd->wq_done, &wait);

	if ((state == TASK_INTERRUPTIBLE) && signal_pending(current))
		ret = -ERESTARTSYS;

	return ret;
unlock:
	spin_unlock_irq(&bd->lock);
@@ -272,7 +256,7 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)
{
	request_queue_t *q = bd->queue;
	struct request *rq, *next_rq = NULL;
	int ret, rw = 0; /* shut up gcc */
	int ret, rw;
	unsigned int dxfer_len;
	void *dxferp = NULL;

@@ -354,9 +338,11 @@ static void bsg_rq_end_io(struct request *rq, int uptodate)
	bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);

	spin_lock_irqsave(&bd->lock, flags);
	list_del(&bc->list);
	bsg_add_done_cmd(bd, bc);
	list_move_tail(&bc->list, &bd->done_list);
	bd->done_cmds++;
	spin_unlock_irqrestore(&bd->lock, flags);

	wake_up(&bd->wq_done);
}

/*
@@ -387,14 +373,15 @@ static void bsg_add_command(struct bsg_device *bd, request_queue_t *q,
	blk_execute_rq_nowait(q, NULL, rq, 1, bsg_rq_end_io);
}

static inline struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
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_entry_bc(bd->done_list.next);
		bsg_del_done_cmd(bd, bc);
		bc = list_entry(bd->done_list.next, struct bsg_command, list);
		list_del(&bc->list);
		bd->done_cmds--;
	}
	spin_unlock_irq(&bd->lock);

@@ -450,7 +437,7 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
	hdr->response_len = 0;

	if (rq->sense_len && hdr->response) {
		int len = min((unsigned int) hdr->max_response_len,
		int len = min_t(unsigned int, hdr->max_response_len,
					rq->sense_len);

		ret = copy_to_user((void*)(unsigned long)hdr->response,
@@ -486,7 +473,7 @@ static int bsg_complete_all_commands(struct bsg_device *bd)
	 */
	ret = 0;
	do {
		ret = bsg_io_schedule(bd, TASK_UNINTERRUPTIBLE);
		ret = bsg_io_schedule(bd);
		/*
		 * look for -ENODATA specifically -- we'll sometimes get
		 * -ERESTARTSYS when we've taken a signal, but we can't
@@ -523,7 +510,7 @@ static int bsg_complete_all_commands(struct bsg_device *bd)
	return ret;
}

static ssize_t
static int
__bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
	   const struct iovec *iov, ssize_t *bytes_read)
{
@@ -550,7 +537,7 @@ __bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
		ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
					       bc->bidi_bio);

		if (copy_to_user(buf, (char *) &bc->hdr, sizeof(bc->hdr)))
		if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
			ret = -EFAULT;

		bsg_free_command(bc);
@@ -582,6 +569,9 @@ static inline void bsg_set_write_perm(struct bsg_device *bd, struct file *file)
		clear_bit(BSG_F_WRITE_PERM, &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)
@@ -610,8 +600,8 @@ bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
	return bytes_read;
}

static ssize_t __bsg_write(struct bsg_device *bd, const char __user *buf,
			   size_t count, ssize_t *bytes_read)
static int __bsg_write(struct bsg_device *bd, const char __user *buf,
		       size_t count, ssize_t *bytes_written)
{
	struct bsg_command *bc;
	struct request *rq;
@@ -655,7 +645,7 @@ static ssize_t __bsg_write(struct bsg_device *bd, const char __user *buf,
		rq = NULL;
		nr_commands--;
		buf += sizeof(struct sg_io_v4);
		*bytes_read += sizeof(struct sg_io_v4);
		*bytes_written += sizeof(struct sg_io_v4);
	}

	if (bc)
@@ -668,7 +658,7 @@ 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_read;
	ssize_t bytes_written;
	int ret;

	dprintk("%s: write %Zd bytes\n", bd->name, count);
@@ -676,18 +666,18 @@ bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
	bsg_set_block(bd, file);
	bsg_set_write_perm(bd, file);

	bytes_read = 0;
	ret = __bsg_write(bd, buf, count, &bytes_read);
	*ppos = bytes_read;
	bytes_written = 0;
	ret = __bsg_write(bd, buf, count, &bytes_written);
	*ppos = bytes_written;

	/*
	 * return bytes written on non-fatal errors
	 */
	if (!bytes_read || (bytes_read && err_block_err(ret)))
		bytes_read = ret;
	if (!bytes_written || (bytes_written && err_block_err(ret)))
		bytes_written = ret;

	dprintk("%s: returning %Zd\n", bd->name, bytes_read);
	return bytes_read;
	dprintk("%s: returning %Zd\n", bd->name, bytes_written);
	return bytes_written;
}

static struct bsg_device *bsg_alloc_device(void)
@@ -746,7 +736,7 @@ static struct bsg_device *bsg_add_device(struct inode *inode,
					 struct request_queue *rq,
					 struct file *file)
{
	struct bsg_device *bd = NULL;
	struct bsg_device *bd;
#ifdef BSG_DEBUG
	unsigned char buf[32];
#endif
@@ -762,7 +752,8 @@ static struct bsg_device *bsg_add_device(struct inode *inode,
	atomic_set(&bd->ref_count, 1);
	bd->minor = iminor(inode);
	mutex_lock(&bsg_mutex);
	hlist_add_head(&bd->dev_list, &bsg_device_list[bsg_list_idx(bd->minor)]);
	hlist_add_head(&bd->dev_list,
		&bsg_device_list[bd->minor & (BSG_LIST_ARRAY_SIZE - 1)]);

	strncpy(bd->name, rq->bsg_dev.class_dev->class_id, sizeof(bd->name) - 1);
	dprintk("bound to <%s>, max queue %d\n",
@@ -774,12 +765,13 @@ static struct bsg_device *bsg_add_device(struct inode *inode,

static struct bsg_device *__bsg_get_device(int minor)
{
	struct hlist_head *list = &bsg_device_list[bsg_list_idx(minor)];
	struct hlist_head *list;
	struct bsg_device *bd = NULL;
	struct hlist_node *entry;

	mutex_lock(&bsg_mutex);

	list = &bsg_device_list[minor & (BSG_LIST_ARRAY_SIZE - 1)];
	hlist_for_each(entry, list) {
		bd = hlist_entry(entry, struct bsg_device, dev_list);
		if (bd->minor == minor) {
@@ -858,16 +850,11 @@ static unsigned int bsg_poll(struct file *file, poll_table *wait)
	return mask;
}

static int
bsg_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
	  unsigned long arg)
static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct bsg_device *bd = file->private_data;
	int __user *uarg = (int __user *) arg;

	if (!bd)
		return -ENXIO;

	switch (cmd) {
		/*
		 * our own ioctls
@@ -944,7 +931,7 @@ static struct file_operations bsg_fops = {
	.poll		=	bsg_poll,
	.open		=	bsg_open,
	.release	=	bsg_release,
	.ioctl		=	bsg_ioctl,
	.unlocked_ioctl	=	bsg_ioctl,
	.owner		=	THIS_MODULE,
};

@@ -952,8 +939,7 @@ void bsg_unregister_queue(struct request_queue *q)
{
	struct bsg_class_device *bcd = &q->bsg_dev;

	if (!bcd->class_dev)
		return;
	WARN_ON(!bcd->class_dev);

	mutex_lock(&bsg_mutex);
	sysfs_remove_link(&q->kobj, "bsg");
@@ -1069,7 +1055,7 @@ static int __init bsg_init(void)
		return -ENOMEM;
	}

	for (i = 0; i < BSG_LIST_SIZE; i++)
	for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
		INIT_HLIST_HEAD(&bsg_device_list[i]);

	bsg_class = class_create(THIS_MODULE, "bsg");