linux-stable/block/bsg.c
Linus Torvalds a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00

1084 lines
23 KiB
C

/*
* 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>
*
* This file is subject to the terms and conditions of the GNU General Public
* License version 2. See the file "COPYING" in the main directory of this
* archive for more details.
*
*/
#include <linux/module.h>
#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>
#include <scsi/scsi.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/sg.h>
#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
#define BSG_VERSION "0.4"
#define bsg_dbg(bd, fmt, ...) \
pr_debug("%s: " fmt, (bd)->name, ##__VA_ARGS__)
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
#define BSG_MAX_DEVS 32768
static DEFINE_MUTEX(bsg_mutex);
static DEFINE_IDR(bsg_minor_idr);
#define BSG_LIST_ARRAY_SIZE 8
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)];
}
static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
struct sg_io_v4 *hdr, struct bsg_device *bd,
fmode_t mode)
{
struct scsi_request *req = scsi_req(rq);
if (hdr->request_len > BLK_MAX_CDB) {
req->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
if (!req->cmd)
return -ENOMEM;
}
if (copy_from_user(req->cmd, (void __user *)(unsigned long)hdr->request,
hdr->request_len))
return -EFAULT;
if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
if (blk_verify_command(req->cmd, mode))
return -EPERM;
} else if (!capable(CAP_SYS_RAWIO))
return -EPERM;
/*
* fill in request structure
*/
req->cmd_len = hdr->request_len;
rq->timeout = msecs_to_jiffies(hdr->timeout);
if (!rq->timeout)
rq->timeout = q->sg_timeout;
if (!rq->timeout)
rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
if (rq->timeout < BLK_MIN_SG_TIMEOUT)
rq->timeout = BLK_MIN_SG_TIMEOUT;
return 0;
}
/*
* Check if sg_io_v4 from user is allowed and valid
*/
static int
bsg_validate_sgv4_hdr(struct sg_io_v4 *hdr, int *op)
{
int ret = 0;
if (hdr->guard != 'Q')
return -EINVAL;
switch (hdr->protocol) {
case BSG_PROTOCOL_SCSI:
switch (hdr->subprotocol) {
case BSG_SUB_PROTOCOL_SCSI_CMD:
case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
break;
default:
ret = -EINVAL;
}
break;
default:
ret = -EINVAL;
}
*op = hdr->dout_xfer_len ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN;
return ret;
}
/*
* map sg_io_v4 to a request.
*/
static struct request *
bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t mode)
{
struct request_queue *q = bd->queue;
struct request *rq, *next_rq = NULL;
int ret;
unsigned int op, dxfer_len;
void __user *dxferp = NULL;
struct bsg_class_device *bcd = &q->bsg_dev;
/* if the LLD has been removed then the bsg_unregister_queue will
* eventually be called and the class_dev was freed, so we can no
* longer use this request_queue. Return no such address.
*/
if (!bcd->class_dev)
return ERR_PTR(-ENXIO);
bsg_dbg(bd, "map hdr %llx/%u %llx/%u\n",
(unsigned long long) hdr->dout_xferp,
hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
hdr->din_xfer_len);
ret = bsg_validate_sgv4_hdr(hdr, &op);
if (ret)
return ERR_PTR(ret);
/*
* map scatter-gather elements separately and string them to request
*/
rq = blk_get_request(q, op, GFP_KERNEL);
if (IS_ERR(rq))
return rq;
ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, mode);
if (ret)
goto out;
if (op == REQ_OP_SCSI_OUT && hdr->din_xfer_len) {
if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
ret = -EOPNOTSUPP;
goto out;
}
next_rq = blk_get_request(q, REQ_OP_SCSI_IN, GFP_KERNEL);
if (IS_ERR(next_rq)) {
ret = PTR_ERR(next_rq);
next_rq = NULL;
goto out;
}
rq->next_rq = next_rq;
dxferp = (void __user *)(unsigned long)hdr->din_xferp;
ret = blk_rq_map_user(q, next_rq, NULL, dxferp,
hdr->din_xfer_len, GFP_KERNEL);
if (ret)
goto out;
}
if (hdr->dout_xfer_len) {
dxfer_len = hdr->dout_xfer_len;
dxferp = (void __user *)(unsigned long)hdr->dout_xferp;
} else if (hdr->din_xfer_len) {
dxfer_len = hdr->din_xfer_len;
dxferp = (void __user *)(unsigned long)hdr->din_xferp;
} else
dxfer_len = 0;
if (dxfer_len) {
ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
GFP_KERNEL);
if (ret)
goto out;
}
return rq;
out:
scsi_req_free_cmd(scsi_req(rq));
blk_put_request(rq);
if (next_rq) {
blk_rq_unmap_user(next_rq->bio);
blk_put_request(next_rq);
}
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)
{
struct scsi_request *req = scsi_req(rq);
int ret = 0;
pr_debug("rq %p bio %p 0x%x\n", rq, bio, req->result);
/*
* fill in all the output members
*/
hdr->device_status = req->result & 0xff;
hdr->transport_status = host_byte(req->result);
hdr->driver_status = driver_byte(req->result);
hdr->info = 0;
if (hdr->device_status || hdr->transport_status || hdr->driver_status)
hdr->info |= SG_INFO_CHECK;
hdr->response_len = 0;
if (req->sense_len && hdr->response) {
int len = min_t(unsigned int, hdr->max_response_len,
req->sense_len);
ret = copy_to_user((void __user *)(unsigned long)hdr->response,
req->sense, len);
if (!ret)
hdr->response_len = len;
else
ret = -EFAULT;
}
if (rq->next_rq) {
hdr->dout_resid = req->resid_len;
hdr->din_resid = scsi_req(rq->next_rq)->resid_len;
blk_rq_unmap_user(bidi_bio);
blk_put_request(rq->next_rq);
} else if (rq_data_dir(rq) == READ)
hdr->din_resid = req->resid_len;
else
hdr->dout_resid = req->resid_len;
/*
* If the request generated a negative error number, return it
* (providing we aren't already returning an error); if it's
* just a protocol response (i.e. non negative), that gets
* processed above.
*/
if (!ret && req->result < 0)
ret = req->result;
blk_rq_unmap_user(bio);
scsi_req_free_cmd(req);
blk_put_request(rq);
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, &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;
bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
if (unlikely(!bd))
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 void bsg_kref_release_function(struct kref *kref)
{
struct bsg_class_device *bcd =
container_of(kref, struct bsg_class_device, ref);
struct device *parent = bcd->parent;
if (bcd->release)
bcd->release(bcd->parent);
put_device(parent);
}
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) {
mutex_unlock(&bsg_mutex);
goto out;
}
hlist_del(&bd->dev_list);
mutex_unlock(&bsg_mutex);
bsg_dbg(bd, "tearing down\n");
/*
* 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:
kref_put(&q->bsg_dev.ref, bsg_kref_release_function);
if (do_free)
blk_put_queue(q);
return ret;
}
static struct bsg_device *bsg_add_device(struct inode *inode,
struct request_queue *rq,
struct file *file)
{
struct bsg_device *bd;
unsigned char buf[32];
if (!blk_queue_scsi_passthrough(rq)) {
WARN_ONCE(true, "Attempt to register a non-SCSI queue\n");
return ERR_PTR(-EINVAL);
}
if (!blk_get_queue(rq))
return ERR_PTR(-ENXIO);
bd = bsg_alloc_device();
if (!bd) {
blk_put_queue(rq);
return ERR_PTR(-ENOMEM);
}
bd->queue = rq;
bsg_set_block(bd, file);
atomic_set(&bd->ref_count, 1);
mutex_lock(&bsg_mutex);
hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
bsg_dbg(bd, "bound to <%s>, max queue %d\n",
format_dev_t(buf, inode->i_rdev), bd->max_queue);
mutex_unlock(&bsg_mutex);
return bd;
}
static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
{
struct bsg_device *bd;
mutex_lock(&bsg_mutex);
hlist_for_each_entry(bd, bsg_dev_idx_hash(minor), dev_list) {
if (bd->queue == q) {
atomic_inc(&bd->ref_count);
goto found;
}
}
bd = NULL;
found:
mutex_unlock(&bsg_mutex);
return bd;
}
static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
{
struct bsg_device *bd;
struct bsg_class_device *bcd;
/*
* find the class device
*/
mutex_lock(&bsg_mutex);
bcd = idr_find(&bsg_minor_idr, iminor(inode));
if (bcd)
kref_get(&bcd->ref);
mutex_unlock(&bsg_mutex);
if (!bcd)
return ERR_PTR(-ENODEV);
bd = __bsg_get_device(iminor(inode), bcd->queue);
if (bd)
return bd;
bd = bsg_add_device(inode, bcd->queue, file);
if (IS_ERR(bd))
kref_put(&bcd->ref, bsg_kref_release_function);
return bd;
}
static int bsg_open(struct inode *inode, struct file *file)
{
struct bsg_device *bd;
bd = bsg_get_device(inode, file);
if (IS_ERR(bd))
return PTR_ERR(bd);
file->private_data = bd;
return 0;
}
static int bsg_release(struct inode *inode, struct file *file)
{
struct bsg_device *bd = file->private_data;
file->private_data = NULL;
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;
int __user *uarg = (int __user *) arg;
int ret;
switch (cmd) {
/*
* our own ioctls
*/
case SG_GET_COMMAND_Q:
return put_user(bd->max_queue, uarg);
case SG_SET_COMMAND_Q: {
int queue;
if (get_user(queue, uarg))
return -EFAULT;
if (queue < 1)
return -EINVAL;
spin_lock_irq(&bd->lock);
bd->max_queue = queue;
spin_unlock_irq(&bd->lock);
return 0;
}
/*
* SCSI/sg ioctls
*/
case SG_GET_VERSION_NUM:
case SCSI_IOCTL_GET_IDLUN:
case SCSI_IOCTL_GET_BUS_NUMBER:
case SG_SET_TIMEOUT:
case SG_GET_TIMEOUT:
case SG_GET_RESERVED_SIZE:
case SG_SET_RESERVED_SIZE:
case SG_EMULATED_HOST:
case SCSI_IOCTL_SEND_COMMAND: {
void __user *uarg = (void __user *) arg;
return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
}
case SG_IO: {
struct request *rq;
struct bio *bio, *bidi_bio = NULL;
struct sg_io_v4 hdr;
int at_head;
if (copy_from_user(&hdr, uarg, sizeof(hdr)))
return -EFAULT;
rq = bsg_map_hdr(bd, &hdr, file->f_mode);
if (IS_ERR(rq))
return PTR_ERR(rq);
bio = rq->bio;
if (rq->next_rq)
bidi_bio = rq->next_rq->bio;
at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
blk_execute_rq(bd->queue, NULL, rq, at_head);
ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
if (copy_to_user(uarg, &hdr, sizeof(hdr)))
return -EFAULT;
return ret;
}
default:
return -ENOTTY;
}
}
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,
.owner = THIS_MODULE,
.llseek = default_llseek,
};
void bsg_unregister_queue(struct request_queue *q)
{
struct bsg_class_device *bcd = &q->bsg_dev;
if (!bcd->class_dev)
return;
mutex_lock(&bsg_mutex);
idr_remove(&bsg_minor_idr, bcd->minor);
if (q->kobj.sd)
sysfs_remove_link(&q->kobj, "bsg");
device_unregister(bcd->class_dev);
bcd->class_dev = NULL;
kref_put(&bcd->ref, bsg_kref_release_function);
mutex_unlock(&bsg_mutex);
}
EXPORT_SYMBOL_GPL(bsg_unregister_queue);
int bsg_register_queue(struct request_queue *q, struct device *parent,
const char *name, void (*release)(struct device *))
{
struct bsg_class_device *bcd;
dev_t dev;
int ret;
struct device *class_dev = NULL;
const char *devname;
if (name)
devname = name;
else
devname = dev_name(parent);
/*
* we need a proper transport to send commands, not a stacked device
*/
if (!queue_is_rq_based(q))
return 0;
bcd = &q->bsg_dev;
memset(bcd, 0, sizeof(*bcd));
mutex_lock(&bsg_mutex);
ret = idr_alloc(&bsg_minor_idr, bcd, 0, BSG_MAX_DEVS, GFP_KERNEL);
if (ret < 0) {
if (ret == -ENOSPC) {
printk(KERN_ERR "bsg: too many bsg devices\n");
ret = -EINVAL;
}
goto unlock;
}
bcd->minor = ret;
bcd->queue = q;
bcd->parent = get_device(parent);
bcd->release = release;
kref_init(&bcd->ref);
dev = MKDEV(bsg_major, bcd->minor);
class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname);
if (IS_ERR(class_dev)) {
ret = PTR_ERR(class_dev);
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 unregister_class_dev;
}
mutex_unlock(&bsg_mutex);
return 0;
unregister_class_dev:
device_unregister(class_dev);
put_dev:
put_device(parent);
idr_remove(&bsg_minor_idr, bcd->minor);
unlock:
mutex_unlock(&bsg_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(bsg_register_queue);
static struct cdev bsg_cdev;
static char *bsg_devnode(struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
}
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;
}
bsg_class->devnode = bsg_devnode;
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)
goto unregister_chrdev;
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(BSG_DESCRIPTION);
MODULE_LICENSE("GPL");
device_initcall(bsg_init);