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-rw-r--r--MAINTAINERS6
-rw-r--r--block/Kconfig13
-rw-r--r--block/bsg.c167
-rw-r--r--include/linux/bsg.h1
4 files changed, 89 insertions, 98 deletions
diff --git a/MAINTAINERS b/MAINTAINERS
index 5abec1435ad8..368a7181fa14 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -913,6 +913,12 @@ M: mchan@broadcom.com
L: netdev@vger.kernel.org
S: Supported
+BSG (block layer generic sg v4 driver)
+P: FUJITA Tomonori
+M: fujita.tomonori@lab.ntt.co.jp
+L: linux-scsi@vger.kernel.org
+S: Supported
+
BTTV VIDEO4LINUX DRIVER
P: Mauro Carvalho Chehab
M: mchehab@infradead.org
diff --git a/block/Kconfig b/block/Kconfig
index 6597b60e8e69..0768741d6813 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -52,11 +52,16 @@ config LSF
endif # BLOCK
config BLK_DEV_BSG
- bool "Block layer SG support"
+ bool "Block layer SG support v4 (EXPERIMENTAL)"
depends on (SCSI=y) && EXPERIMENTAL
- default y
---help---
- Saying Y here will enable generic SG (SCSI generic) v4
- support for any block device.
+ Saying Y here will enable generic SG (SCSI generic) v4 support
+ for any block device.
+
+ Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4
+ can handle complicated SCSI commands: tagged variable length cdbs
+ with bidirectional data transfers and generic request/response
+ protocols (e.g. Task Management Functions and SMP in Serial
+ Attached SCSI).
source block/Kconfig.iosched
diff --git a/block/bsg.c b/block/bsg.c
index 576933fe1860..baa04e7adf19 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -33,7 +33,8 @@
#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;
@@ -68,22 +69,15 @@ enum {
#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;
-#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;
@@ -128,7 +122,7 @@ 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 +130,6 @@ 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 +139,12 @@ 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)
+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;
@@ -186,14 +169,11 @@ 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 +252,7 @@ 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 +334,11 @@ 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 +369,15 @@ 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);
@@ -450,8 +433,8 @@ 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,
- 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);
@@ -486,7 +469,7 @@ 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 +506,7 @@ 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 +533,7 @@ __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 +565,9 @@ 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 +596,8 @@ 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 +641,7 @@ 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 +654,7 @@ 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 +662,18 @@ 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 +732,7 @@ 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 +748,7 @@ 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_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",
@@ -774,13 +760,12 @@ 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 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);
@@ -858,16 +843,11 @@ 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 +924,7 @@ 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,
};
@@ -952,12 +932,11 @@ 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");
- class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor));
+ class_device_destroy(bsg_class, MKDEV(bsg_major, bcd->minor));
bcd->class_dev = NULL;
list_del_init(&bcd->list);
bsg_device_nr--;
@@ -1003,7 +982,7 @@ retry:
bsg_minor_idx = 0;
bcd->queue = q;
- dev = MKDEV(BSG_MAJOR, bcd->minor);
+ dev = MKDEV(bsg_major, bcd->minor);
class_dev = class_device_create(bsg_class, NULL, dev, bcd->dev, "%s", name);
if (IS_ERR(class_dev)) {
ret = PTR_ERR(class_dev);
@@ -1024,7 +1003,7 @@ retry:
return 0;
err:
if (class_dev)
- class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor));
+ class_device_destroy(bsg_class, MKDEV(bsg_major, bcd->minor));
mutex_unlock(&bsg_mutex);
return ret;
}
@@ -1061,6 +1040,7 @@ static struct cdev bsg_cdev = {
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);
@@ -1069,46 +1049,47 @@ 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");
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;
+
+ bsg_major = MAJOR(devid);
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;
- }
+ ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
+ if (ret)
+ goto unregister_chrdev;
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;
- }
+ if (ret)
+ goto remove_cdev;
- printk(KERN_INFO "%s loaded\n", bsg_version);
+ printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
+ " loaded (major %d)\n", bsg_major);
return 0;
+remove_cdev:
+ printk(KERN_ERR "bsg: failed register scsi interface %d\n", ret);
+ cdev_del(&bsg_cdev);
+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);
diff --git a/include/linux/bsg.h b/include/linux/bsg.h
index bd998ca6cb2e..8547b10c388b 100644
--- a/include/linux/bsg.h
+++ b/include/linux/bsg.h
@@ -60,7 +60,6 @@ struct bsg_class_device {
extern int bsg_register_queue(struct request_queue *, const char *);
extern void bsg_unregister_queue(struct request_queue *);
#else
-struct bsg_class_device { };
#define bsg_register_queue(disk, name) (0)
#define bsg_unregister_queue(disk) do { } while (0)
#endif
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.