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

block/bsg.c

+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 @@ static struct bsg_command *bsg_alloc_command(struct bsg_device *bd) 
	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");