/*
- * bsg.c - block layer implementation of the sg v3 interface
+ * bsg.c - block layer implementation of the sg v4 interface
*
* Copyright (C) 2004 Jens Axboe <axboe@suse.de> SUSE Labs
* Copyright (C) 2004 Peter M. Jones <pjones@redhat.com>
* archive for more details.
*
*/
-/*
- * TODO
- * - Should this get merged, block/scsi_ioctl.c will be migrated into
- * this file. To keep maintenance down, it's easier to have them
- * seperated right now.
- *
- */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/file.h>
#include <linux/cdev.h>
#include <linux/percpu.h>
#include <linux/uio.h>
+#include <linux/idr.h>
#include <linux/bsg.h>
#include <scsi/scsi.h>
#include <scsi/scsi_driver.h>
#include <scsi/sg.h>
-static char bsg_version[] = "block layer sg (bsg) 0.4";
+#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
+#define BSG_VERSION "0.4"
struct bsg_device {
- request_queue_t *queue;
+ struct request_queue *queue;
spinlock_t lock;
struct list_head busy_list;
struct list_head done_list;
#define dprintk(fmt, args...)
#endif
-#define list_entry_bc(entry) list_entry((entry), struct bsg_command, list)
-
-/*
- * just for testing
- */
-#define BSG_MAJOR (240)
-
static DEFINE_MUTEX(bsg_mutex);
-static int bsg_device_nr, bsg_minor_idx;
+static DEFINE_IDR(bsg_minor_idr);
-#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
+static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
static struct class *bsg_class;
-static LIST_HEAD(bsg_class_list);
+static int bsg_major;
static struct kmem_cache *bsg_cmd_cachep;
struct bio *bidi_bio;
int err;
struct sg_io_v4 hdr;
- struct sg_io_v4 __user *uhdr;
char sense[SCSI_SENSE_BUFFERSIZE];
};
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--;
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);
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)
+static inline struct hlist_head *bsg_dev_idx_hash(int index)
{
- bd->done_cmds++;
- list_add_tail(&bc->list, &bd->done_list);
- wake_up(&bd->wq_done);
+ return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
}
-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;
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);
return ret;
}
-static int blk_fill_sgv4_hdr_rq(request_queue_t *q, struct request *rq,
+static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
struct sg_io_v4 *hdr, int has_write_perm)
{
memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
* Check if sg_io_v4 from user is allowed and valid
*/
static int
-bsg_validate_sgv4_hdr(request_queue_t *q, struct sg_io_v4 *hdr, int *rw)
+bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw)
{
int ret = 0;
static struct request *
bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)
{
- request_queue_t *q = bd->queue;
+ struct request_queue *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;
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);
}
/*
* 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, request_queue_t *q,
+static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
struct bsg_command *bc, struct request *rq)
{
rq->sense = bc->sense;
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);
hdr->info = 0;
if (hdr->device_status || hdr->transport_status || hdr->driver_status)
hdr->info |= SG_INFO_CHECK;
- hdr->din_resid = rq->data_len;
hdr->response_len = 0;
if (rq->sense_len && hdr->response) {
- int len = min((unsigned int) hdr->max_response_len,
- rq->sense_len);
+ int len = min_t(unsigned int, hdr->max_response_len,
+ rq->sense_len);
ret = copy_to_user((void*)(unsigned long)hdr->response,
rq->sense, len);
}
if (rq->next_rq) {
+ hdr->dout_resid = rq->data_len;
+ hdr->din_resid = rq->next_rq->data_len;
blk_rq_unmap_user(bidi_bio);
blk_put_request(rq->next_rq);
- }
+ } else if (rq_data_dir(rq) == READ)
+ hdr->din_resid = rq->data_len;
+ else
+ hdr->dout_resid = rq->data_len;
blk_rq_unmap_user(bio);
blk_put_request(rq);
*/
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
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)
{
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);
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)
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;
bc = NULL;
ret = 0;
while (nr_commands) {
- request_queue_t *q = bd->queue;
+ struct request_queue *q = bd->queue;
bc = bsg_alloc_command(bd);
if (IS_ERR(bc)) {
break;
}
- bc->uhdr = (struct sg_io_v4 __user *) buf;
if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
ret = -EFAULT;
break;
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)
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);
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)
struct request_queue *rq,
struct file *file)
{
- struct bsg_device *bd = NULL;
+ struct bsg_device *bd;
#ifdef BSG_DEBUG
unsigned char buf[32];
#endif
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_dev_idx_hash(bd->minor));
strncpy(bd->name, rq->bsg_dev.class_dev->class_id, sizeof(bd->name) - 1);
dprintk("bound to <%s>, max queue %d\n",
static struct bsg_device *__bsg_get_device(int minor)
{
- struct hlist_head *list = &bsg_device_list[bsg_list_idx(minor)];
struct bsg_device *bd = NULL;
struct hlist_node *entry;
mutex_lock(&bsg_mutex);
- hlist_for_each(entry, list) {
+ hlist_for_each(entry, bsg_dev_idx_hash(minor)) {
bd = hlist_entry(entry, struct bsg_device, dev_list);
if (bd->minor == minor) {
atomic_inc(&bd->ref_count);
static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
{
- struct bsg_device *bd = __bsg_get_device(iminor(inode));
- struct bsg_class_device *bcd, *__bcd;
+ struct bsg_device *bd;
+ struct bsg_class_device *bcd;
+ bd = __bsg_get_device(iminor(inode));
if (bd)
return bd;
/*
* find the class device
*/
- bcd = NULL;
mutex_lock(&bsg_mutex);
- list_for_each_entry(__bcd, &bsg_class_list, list) {
- if (__bcd->minor == iminor(inode)) {
- bcd = __bcd;
- break;
- }
- }
+ bcd = idr_find(&bsg_minor_idr, iminor(inode));
mutex_unlock(&bsg_mutex);
if (!bcd)
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
.poll = bsg_poll,
.open = bsg_open,
.release = bsg_release,
- .ioctl = bsg_ioctl,
+ .unlocked_ioctl = bsg_ioctl,
.owner = THIS_MODULE,
};
return;
mutex_lock(&bsg_mutex);
+ idr_remove(&bsg_minor_idr, bcd->minor);
sysfs_remove_link(&q->kobj, "bsg");
- class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor));
+ class_device_unregister(bcd->class_dev);
+ put_device(bcd->dev);
bcd->class_dev = NULL;
- list_del_init(&bcd->list);
- bsg_device_nr--;
+ bcd->dev = NULL;
mutex_unlock(&bsg_mutex);
}
EXPORT_SYMBOL_GPL(bsg_unregister_queue);
-int bsg_register_queue(struct request_queue *q, const char *name)
+int bsg_register_queue(struct request_queue *q, struct device *gdev,
+ const char *name)
{
- struct bsg_class_device *bcd, *__bcd;
+ struct bsg_class_device *bcd;
dev_t dev;
- int ret = -EMFILE;
+ int ret, minor;
struct class_device *class_dev = NULL;
+ const char *devname;
+
+ if (name)
+ devname = name;
+ else
+ devname = gdev->bus_id;
/*
* we need a proper transport to send commands, not a stacked device
bcd = &q->bsg_dev;
memset(bcd, 0, sizeof(*bcd));
- INIT_LIST_HEAD(&bcd->list);
mutex_lock(&bsg_mutex);
- if (bsg_device_nr == BSG_MAX_DEVS) {
- printk(KERN_ERR "bsg: too many bsg devices\n");
- goto err;
- }
-retry:
- list_for_each_entry(__bcd, &bsg_class_list, list) {
- if (__bcd->minor == bsg_minor_idx) {
- bsg_minor_idx++;
- if (bsg_minor_idx == BSG_MAX_DEVS)
- bsg_minor_idx = 0;
- goto retry;
- }
+ ret = idr_pre_get(&bsg_minor_idr, GFP_KERNEL);
+ if (!ret) {
+ ret = -ENOMEM;
+ goto unlock;
}
- bcd->minor = bsg_minor_idx++;
- if (bsg_minor_idx == BSG_MAX_DEVS)
- bsg_minor_idx = 0;
+ ret = idr_get_new(&bsg_minor_idr, bcd, &minor);
+ if (ret < 0)
+ goto unlock;
+
+ if (minor >= BSG_MAX_DEVS) {
+ printk(KERN_ERR "bsg: too many bsg devices\n");
+ ret = -EINVAL;
+ goto remove_idr;
+ }
+ bcd->minor = minor;
bcd->queue = q;
- dev = MKDEV(BSG_MAJOR, bcd->minor);
- class_dev = class_device_create(bsg_class, NULL, dev, bcd->dev, "%s", name);
+ bcd->dev = get_device(gdev);
+ dev = MKDEV(bsg_major, bcd->minor);
+ class_dev = class_device_create(bsg_class, NULL, dev, gdev, "%s",
+ devname);
if (IS_ERR(class_dev)) {
ret = PTR_ERR(class_dev);
- goto err;
+ goto put_dev;
}
bcd->class_dev = class_dev;
if (q->kobj.sd) {
ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
if (ret)
- goto err;
+ goto unregister_class_dev;
}
- list_add_tail(&bcd->list, &bsg_class_list);
- bsg_device_nr++;
-
mutex_unlock(&bsg_mutex);
return 0;
-err:
- if (class_dev)
- class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor));
+
+unregister_class_dev:
+ class_device_unregister(class_dev);
+put_dev:
+ put_device(gdev);
+remove_idr:
+ idr_remove(&bsg_minor_idr, minor);
+unlock:
mutex_unlock(&bsg_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(bsg_register_queue);
-static int bsg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
-{
- int ret;
- struct scsi_device *sdp = to_scsi_device(cl_dev->dev);
- struct request_queue *rq = sdp->request_queue;
-
- if (rq->kobj.parent)
- ret = bsg_register_queue(rq, kobject_name(rq->kobj.parent));
- else
- ret = bsg_register_queue(rq, kobject_name(&sdp->sdev_gendev.kobj));
- return ret;
-}
-
-static void bsg_remove(struct class_device *cl_dev, struct class_interface *cl_intf)
-{
- bsg_unregister_queue(to_scsi_device(cl_dev->dev)->request_queue);
-}
-
-static struct class_interface bsg_intf = {
- .add = bsg_add,
- .remove = bsg_remove,
-};
-
static struct cdev bsg_cdev = {
.kobj = {.name = "bsg", },
.owner = THIS_MODULE,
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, NULL);
+ 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_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");
if (IS_ERR(bsg_class)) {
- kmem_cache_destroy(bsg_cmd_cachep);
- return PTR_ERR(bsg_class);
+ ret = PTR_ERR(bsg_class);
+ goto destroy_kmemcache;
}
- ret = register_chrdev_region(MKDEV(BSG_MAJOR, 0), BSG_MAX_DEVS, "bsg");
- if (ret) {
- kmem_cache_destroy(bsg_cmd_cachep);
- class_destroy(bsg_class);
- return ret;
- }
+ ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
+ if (ret)
+ goto destroy_bsg_class;
- cdev_init(&bsg_cdev, &bsg_fops);
- ret = cdev_add(&bsg_cdev, MKDEV(BSG_MAJOR, 0), BSG_MAX_DEVS);
- if (ret) {
- kmem_cache_destroy(bsg_cmd_cachep);
- class_destroy(bsg_class);
- unregister_chrdev_region(MKDEV(BSG_MAJOR, 0), BSG_MAX_DEVS);
- return ret;
- }
+ bsg_major = MAJOR(devid);
- ret = scsi_register_interface(&bsg_intf);
- if (ret) {
- printk(KERN_ERR "bsg: failed register scsi interface %d\n", ret);
- kmem_cache_destroy(bsg_cmd_cachep);
- class_destroy(bsg_class);
- unregister_chrdev(BSG_MAJOR, "bsg");
- return ret;
- }
+ 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 "%s loaded\n", bsg_version);
+ 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);
+destroy_kmemcache:
+ kmem_cache_destroy(bsg_cmd_cachep);
+ return ret;
}
MODULE_AUTHOR("Jens Axboe");
-MODULE_DESCRIPTION("Block layer SGSI generic (sg) driver");
+MODULE_DESCRIPTION(BSG_DESCRIPTION);
MODULE_LICENSE("GPL");
device_initcall(bsg_init);
git.samba.org / sfrench / cifs-2.6.git / blobdiff