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bsg: support for full generic block layer SG v3

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Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe 2007-07-09 12:38:05 +02:00
parent 8f41958bdd
commit 3d6392cfbd
10 changed files with 1171 additions and 79 deletions
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7
block/Kconfig
View File

@ -51,4 +51,11 @@ config LSF
endif # BLOCK
config BLK_DEV_BSG
bool "Block layer SG support"
default y
---help---
Saying Y here will enable generic SG (SCSI generic) v3
support for any block device.
source block/Kconfig.iosched

1
block/Makefile
View File

@ -4,6 +4,7 @@
obj-$(CONFIG_BLOCK) := elevator.o ll_rw_blk.o ioctl.o genhd.o scsi_ioctl.o
obj-$(CONFIG_BLK_DEV_BSG) += bsg.o
obj-$(CONFIG_IOSCHED_NOOP) += noop-iosched.o
obj-$(CONFIG_IOSCHED_AS) += as-iosched.o
obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o

997
block/bsg.c Normal file
View File

@ -0,0 +1,997 @@
/*
* bsg.c - block layer implementation of the sg v3 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.
*
*/
/*
* 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/config.h>
#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/percpu.h>
#include <linux/uio.h>
#include <linux/bsg.h>
#include <scsi/scsi.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/sg.h>
static char bsg_version[] = "block layer sg (bsg) 0.4";
struct bsg_command;
struct bsg_device {
struct gendisk *disk;
request_queue_t *queue;
spinlock_t lock;
struct list_head busy_list;
struct list_head done_list;
struct hlist_node dev_list;
atomic_t ref_count;
int minor;
int queued_cmds;
int done_cmds;
unsigned long *cmd_bitmap;
struct bsg_command *cmd_map;
wait_queue_head_t wq_done;
wait_queue_head_t wq_free;
char name[BDEVNAME_SIZE];
int max_queue;
unsigned long flags;
};
enum {
BSG_F_BLOCK = 1,
BSG_F_WRITE_PERM = 2,
};
/*
* command allocation bitmap defines
*/
#define BSG_CMDS_PAGE_ORDER (1)
#define BSG_CMDS_PER_LONG (sizeof(unsigned long) * 8)
#define BSG_CMDS_MASK (BSG_CMDS_PER_LONG - 1)
#define BSG_CMDS_BYTES (PAGE_SIZE * (1 << BSG_CMDS_PAGE_ORDER))
#define BSG_CMDS (BSG_CMDS_BYTES / sizeof(struct bsg_command))
#undef BSG_DEBUG
#ifdef BSG_DEBUG
#define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __FUNCTION__, ##args)
#else
#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;
#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];
static struct class *bsg_class;
static LIST_HEAD(bsg_class_list);
/*
* our internal command type
*/
struct bsg_command {
struct bsg_device *bd;
struct list_head list;
struct request *rq;
struct bio *bio;
int err;
struct sg_io_hdr hdr;
struct sg_io_hdr __user *uhdr;
char sense[SCSI_SENSE_BUFFERSIZE];
};
static void bsg_free_command(struct bsg_command *bc)
{
struct bsg_device *bd = bc->bd;
unsigned long bitnr = bc - bd->cmd_map;
unsigned long flags;
dprintk("%s: command bit offset %lu\n", bd->name, bitnr);
spin_lock_irqsave(&bd->lock, flags);
bd->queued_cmds--;
__clear_bit(bitnr, bd->cmd_bitmap);
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 = NULL;
unsigned long *map;
int free_nr;
spin_lock_irq(&bd->lock);
if (bd->queued_cmds >= bd->max_queue)
goto out;
for (free_nr = 0, map = bd->cmd_bitmap; *map == ~0UL; map++)
free_nr += BSG_CMDS_PER_LONG;
BUG_ON(*map == ~0UL);
bd->queued_cmds++;
free_nr += ffz(*map);
__set_bit(free_nr, bd->cmd_bitmap);
spin_unlock_irq(&bd->lock);
bc = bd->cmd_map + free_nr;
memset(bc, 0, sizeof(*bc));
bc->bd = bd;
INIT_LIST_HEAD(&bc->list);
dprintk("%s: returning free cmd %p (bit %d)\n", bd->name, bc, free_nr);
return bc;
out:
dprintk("%s: failed (depth %d)\n", bd->name, bd->queued_cmds);
spin_unlock_irq(&bd->lock);
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)
{
DEFINE_WAIT(wait);
int ret = 0;
spin_lock_irq(&bd->lock);
BUG_ON(bd->done_cmds > bd->queued_cmds);
/*
* -ENOSPC or -ENODATA? I'm going for -ENODATA, meaning "I have no
* work to do", even though we return -ENOSPC after this same test
* during bsg_write() -- there, it means our buffer can't have more
* bsg_commands added to it, thus has no space left.
*/
if (bd->done_cmds == bd->queued_cmds) {
ret = -ENODATA;
goto unlock;
}
if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
ret = -EAGAIN;
goto unlock;
}
prepare_to_wait(&bd->wq_done, &wait, state);
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;
}
/*
* get a new free command, blocking if needed and specified
*/
static struct bsg_command *bsg_get_command(struct bsg_device *bd)
{
struct bsg_command *bc;
int ret;
do {
bc = __bsg_alloc_command(bd);
if (bc)
break;
ret = bsg_io_schedule(bd, TASK_INTERRUPTIBLE);
if (ret) {
bc = ERR_PTR(ret);
break;
}
} while (1);
return bc;
}
/*
* Check if sg_io_hdr from user is allowed and valid
*/
static int
bsg_validate_sghdr(request_queue_t *q, struct sg_io_hdr *hdr, int *rw)
{
if (hdr->interface_id != 'S')
return -EINVAL;
if (hdr->cmd_len > BLK_MAX_CDB)
return -EINVAL;
if (hdr->dxfer_len > (q->max_sectors << 9))
return -EIO;
/*
* looks sane, if no data then it should be fine from our POV
*/
if (!hdr->dxfer_len)
return 0;
switch (hdr->dxfer_direction) {
case SG_DXFER_TO_FROM_DEV:
case SG_DXFER_FROM_DEV:
*rw = READ;
break;
case SG_DXFER_TO_DEV:
*rw = WRITE;
break;
default:
return -EINVAL;
}
return 0;
}
/*
* map sg_io_hdr to a request. for scatter-gather sg_io_hdr, we map
* each segment to a bio and string multiple bio's to the request
*/
static struct request *
bsg_map_hdr(struct bsg_device *bd, int rw, struct sg_io_hdr *hdr)
{
request_queue_t *q = bd->queue;
struct sg_iovec iov;
struct sg_iovec __user *u_iov;
struct request *rq;
int ret, i = 0;
dprintk("map hdr %p/%d/%d\n", hdr->dxferp, hdr->dxfer_len,
hdr->iovec_count);
ret = bsg_validate_sghdr(q, hdr, &rw);
if (ret)
return ERR_PTR(ret);
/*
* map scatter-gather elements seperately and string them to request
*/
rq = blk_get_request(q, rw, GFP_KERNEL);
ret = blk_fill_sghdr_rq(q, rq, hdr, test_bit(BSG_F_WRITE_PERM,
&bd->flags));
if (ret) {
blk_put_request(rq);
return ERR_PTR(ret);
}
if (!hdr->iovec_count) {
ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len);
if (ret)
goto out;
}
u_iov = hdr->dxferp;
for (ret = 0, i = 0; i < hdr->iovec_count; i++, u_iov++) {
if (copy_from_user(&iov, u_iov, sizeof(iov))) {
ret = -EFAULT;
break;
}
if (!iov.iov_len || !iov.iov_base) {
ret = -EINVAL;
break;
}
ret = blk_rq_map_user(q, rq, iov.iov_base, iov.iov_len);
if (ret)
break;
}
/*
* bugger, cleanup
*/
if (ret) {
out:
dprintk("failed map at %d: %d\n", i, ret);
blk_unmap_sghdr_rq(rq, hdr);
rq = ERR_PTR(ret);
}
return rq;
}
/*
* 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, int uptodate)
{
struct bsg_command *bc = rq->end_io_data;
struct bsg_device *bd = bc->bd;
unsigned long flags;
dprintk("%s: finished rq %p bio %p, bc %p offset %ld stat %d\n",
bd->name, rq, bc, bc->bio, bc - bd->cmd_map, 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);
spin_unlock_irqrestore(&bd->lock, flags);
}
/*
* 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,
struct bsg_command *bc, struct request *rq)
{
rq->sense = bc->sense;
rq->sense_len = 0;
/*
* add bc command to busy queue and submit rq for io
*/
bc->rq = rq;
bc->bio = rq->bio;
bc->hdr.duration = jiffies;
spin_lock_irq(&bd->lock);
list_add_tail(&bc->list, &bd->busy_list);
spin_unlock_irq(&bd->lock);
dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
rq->end_io_data = bc;
blk_execute_rq_nowait(q, bd->disk, rq, 1, bsg_rq_end_io);
}
static inline 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);
}
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, int state)
{
struct bsg_command *bc;
int ret;
do {
bc = bsg_next_done_cmd(bd);
if (bc)
break;
ret = bsg_io_schedule(bd, state);
if (ret) {
bc = ERR_PTR(ret);
break;
}
} while (1);
dprintk("%s: returning done %p\n", bd->name, bc);
return bc;
}
static struct bsg_command *
bsg_get_done_cmd(struct bsg_device *bd, const struct iovec *iov)
{
return __bsg_get_done_cmd(bd, TASK_INTERRUPTIBLE);
}
static struct bsg_command *
bsg_get_done_cmd_nosignals(struct bsg_device *bd)
{
return __bsg_get_done_cmd(bd, TASK_UNINTERRUPTIBLE);
}
static int bsg_complete_all_commands(struct bsg_device *bd)
{
struct bsg_command *bc;
int ret, tret;
dprintk("%s: entered\n", bd->name);
set_bit(BSG_F_BLOCK, &bd->flags);
/*
* wait for all commands to complete
*/
ret = 0;
do {
ret = bsg_io_schedule(bd, TASK_UNINTERRUPTIBLE);
/*
* look for -ENODATA specifically -- we'll sometimes get
* -ERESTARTSYS when we've taken a signal, but we can't
* return until we're done freeing the queue, so ignore
* it. The signal will get handled when we're done freeing
* the bsg_device.
*/
} while (ret != -ENODATA);
/*
* discard done commands
*/
ret = 0;
do {
bc = bsg_get_done_cmd_nosignals(bd);
/*
* we _must_ complete before restarting, because
* bsg_release can't handle this failing.
*/
if (PTR_ERR(bc) == -ERESTARTSYS)
continue;
if (IS_ERR(bc)) {
ret = PTR_ERR(bc);
break;
}
tret = blk_complete_sghdr_rq(bc->rq, &bc->hdr, bc->bio);
if (!ret)
ret = tret;
bsg_free_command(bc);
} while (1);
return ret;
}
typedef struct bsg_command *(*bsg_command_callback)(struct bsg_device *bd, const struct iovec *iov);
static ssize_t
__bsg_read(char __user *buf, size_t count, bsg_command_callback get_bc,
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_hdr))
return -EINVAL;
ret = 0;
nr_commands = count / sizeof(struct sg_io_hdr);
while (nr_commands) {
bc = get_bc(bd, iov);
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_sghdr_rq(bc->rq, &bc->hdr, bc->bio);
if (copy_to_user(buf, (char *) &bc->hdr, sizeof(bc->hdr)))
ret = -EFAULT;
bsg_free_command(bc);
if (ret)
break;
buf += sizeof(struct sg_io_hdr);
*bytes_read += sizeof(struct sg_io_hdr);
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);
}
static inline void bsg_set_write_perm(struct bsg_device *bd, struct file *file)
{
if (file->f_mode & FMODE_WRITE)
set_bit(BSG_F_WRITE_PERM, &bd->flags);
else
clear_bit(BSG_F_WRITE_PERM, &bd->flags);
}
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;
dprintk("%s: read %lu bytes\n", bd->name, count);
bsg_set_block(bd, file);
bytes_read = 0;
ret = __bsg_read(buf, count, bsg_get_done_cmd,
bd, NULL, &bytes_read);
*ppos = bytes_read;
if (!bytes_read || (bytes_read && err_block_err(ret)))
bytes_read = ret;
return bytes_read;
}
static ssize_t __bsg_write(struct bsg_device *bd, const char __user *buf,
size_t count, ssize_t *bytes_read)
{
struct bsg_command *bc;
struct request *rq;
int ret, nr_commands;
if (count % sizeof(struct sg_io_hdr))
return -EINVAL;
nr_commands = count / sizeof(struct sg_io_hdr);
rq = NULL;
bc = NULL;
ret = 0;
while (nr_commands) {
request_queue_t *q = bd->queue;
int rw = READ;
bc = bsg_get_command(bd);
if (!bc)
break;
if (IS_ERR(bc)) {
ret = PTR_ERR(bc);
bc = NULL;
break;
}
bc->uhdr = (struct sg_io_hdr __user *) buf;
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, rw, &bc->hdr);
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_hdr);
*bytes_read += sizeof(struct sg_io_hdr);
}
if (rq)
blk_unmap_sghdr_rq(rq, &bc->hdr);
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_read;
int ret;
dprintk("%s: write %lu 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;
/*
* return bytes written on non-fatal errors
*/
if (!bytes_read || (bytes_read && err_block_err(ret)))
bytes_read = ret;
dprintk("%s: returning %lu\n", bd->name, bytes_read);
return bytes_read;
}
static void bsg_free_device(struct bsg_device *bd)
{
if (bd->cmd_map)
free_pages((unsigned long) bd->cmd_map, BSG_CMDS_PAGE_ORDER);
kfree(bd->cmd_bitmap);
kfree(bd);
}
static struct bsg_device *bsg_alloc_device(void)
{
struct bsg_command *cmd_map;
unsigned long *cmd_bitmap;
struct bsg_device *bd;
int bits;
bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
if (unlikely(!bd))
return NULL;
spin_lock_init(&bd->lock);
bd->max_queue = BSG_CMDS;
bits = (BSG_CMDS / BSG_CMDS_PER_LONG) + 1;
cmd_bitmap = kzalloc(bits * sizeof(unsigned long), GFP_KERNEL);
if (!cmd_bitmap)
goto out_free_bd;
bd->cmd_bitmap = cmd_bitmap;
cmd_map = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
BSG_CMDS_PAGE_ORDER);
if (!cmd_map)
goto out_free_bitmap;
bd->cmd_map = cmd_map;
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;
out_free_bitmap:
kfree(cmd_bitmap);
out_free_bd:
kfree(bd);
return NULL;
}
static int bsg_put_device(struct bsg_device *bd)
{
int ret = 0;
mutex_lock(&bsg_mutex);
if (!atomic_dec_and_test(&bd->ref_count))
goto out;
dprintk("%s: tearing down\n", bd->name);
/*
* 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);
blk_put_queue(bd->queue);
hlist_del(&bd->dev_list);
bsg_free_device(bd);
out:
mutex_unlock(&bsg_mutex);
return ret;
}
static struct bsg_device *bsg_add_device(struct inode *inode,
struct gendisk *disk,
struct file *file)
{
struct bsg_device *bd = NULL;
#ifdef BSG_DEBUG
unsigned char buf[32];
#endif
bd = bsg_alloc_device();
if (!bd)
return ERR_PTR(-ENOMEM);
bd->disk = disk;
bd->queue = disk->queue;
kobject_get(&disk->queue->kobj);
bsg_set_block(bd, file);
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)]);
strncpy(bd->name, disk->disk_name, sizeof(bd->name) - 1);
dprintk("bound to <%s>, max queue %d\n",
format_dev_t(buf, i->i_rdev), bd->max_queue);
mutex_unlock(&bsg_mutex);
return bd;
}
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) {
bd = hlist_entry(entry, struct bsg_device, dev_list);
if (bd->minor == minor) {
atomic_inc(&bd->ref_count);
break;
}
bd = NULL;
}
mutex_unlock(&bsg_mutex);
return bd;
}
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;
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;
}
}
mutex_unlock(&bsg_mutex);
if (!bcd)
return ERR_PTR(-ENODEV);
return bsg_add_device(inode, bcd->disk, file);
}
static int bsg_open(struct inode *inode, struct file *file)
{
struct bsg_device *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 unsigned int bsg_poll(struct file *file, poll_table *wait)
{
struct bsg_device *bd = file->private_data;
unsigned int 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 |= POLLIN | POLLRDNORM;
if (bd->queued_cmds >= bd->max_queue)
mask |= POLLOUT;
spin_unlock_irq(&bd->lock);
return mask;
}
static int
bsg_ioctl(struct inode *inode, 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
*/
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 > BSG_CMDS || queue < 1)
return -EINVAL;
bd->max_queue = queue;
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 SG_IO:
case SCSI_IOCTL_SEND_COMMAND: {
void __user *uarg = (void __user *) arg;
return scsi_cmd_ioctl(file, bd->disk, cmd, uarg);
}
/*
* block device ioctls
*/
default:
#if 0
return ioctl_by_bdev(bd->bdev, cmd, arg);
#else
return -ENOTTY;
#endif
}
}
static struct file_operations bsg_fops = {
.read = bsg_read,
.write = bsg_write,
.poll = bsg_poll,
.open = bsg_open,
.release = bsg_release,
.ioctl = bsg_ioctl,
.owner = THIS_MODULE,
};
void bsg_unregister_disk(struct gendisk *disk)
{
struct bsg_class_device *bcd = &disk->bsg_dev;
if (!bcd->class_dev)
return;
mutex_lock(&bsg_mutex);
sysfs_remove_link(&bcd->disk->queue->kobj, "bsg");
class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor));
bcd->class_dev = NULL;
list_del_init(&bcd->list);
mutex_unlock(&bsg_mutex);
}
int bsg_register_disk(struct gendisk *disk)
{
request_queue_t *q = disk->queue;
struct bsg_class_device *bcd;
dev_t dev;
/*
* we need a proper transport to send commands, not a stacked device
*/
if (!q->request_fn)
return 0;
bcd = &disk->bsg_dev;
memset(bcd, 0, sizeof(*bcd));
INIT_LIST_HEAD(&bcd->list);
mutex_lock(&bsg_mutex);
dev = MKDEV(BSG_MAJOR, bsg_device_nr);
bcd->minor = bsg_device_nr;
bsg_device_nr++;
bcd->disk = disk;
bcd->class_dev = class_device_create(bsg_class, NULL, dev, bcd->dev, "%s", disk->disk_name);
list_add_tail(&bcd->list, &bsg_class_list);
sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
mutex_unlock(&bsg_mutex);
return 0;
}
static int __init bsg_init(void)
{
int ret, i;
for (i = 0; i < BSG_LIST_SIZE; i++)
INIT_HLIST_HEAD(&bsg_device_list[i]);
bsg_class = class_create(THIS_MODULE, "bsg");
if (IS_ERR(bsg_class))
return PTR_ERR(bsg_class);
ret = register_chrdev(BSG_MAJOR, "bsg", &bsg_fops);
if (ret) {
class_destroy(bsg_class);
return ret;
}
printk(KERN_INFO "%s loaded\n", bsg_version);
return 0;
}
MODULE_AUTHOR("Jens Axboe");
MODULE_DESCRIPTION("Block layer SGSI generic (sg) driver");
MODULE_LICENSE("GPL");
subsys_initcall(bsg_init);

8
block/ll_rw_blk.c
View File

@ -4091,6 +4091,13 @@ int blk_register_queue(struct gendisk *disk)
return ret;
}
ret = bsg_register_disk(disk);
if (ret) {
elv_unregister_queue(q);
kobject_unregister(&q->kobj);
return ret;
}
return 0;
}
@ -4099,6 +4106,7 @@ void blk_unregister_queue(struct gendisk *disk)
request_queue_t *q = disk->queue;
if (q && q->request_fn) {
bsg_unregister_disk(disk);
elv_unregister_queue(q);
kobject_uevent(&q->kobj, KOBJ_REMOVE);

163
block/scsi_ioctl.c
View File

@ -41,8 +41,6 @@ const unsigned char scsi_command_size[8] =
EXPORT_SYMBOL(scsi_command_size);
#define BLK_DEFAULT_TIMEOUT (60 * HZ)
#include <scsi/sg.h>
static int sg_get_version(int __user *p)
@ -114,7 +112,7 @@ static int sg_emulated_host(request_queue_t *q, int __user *p)
#define safe_for_read(cmd) [cmd] = CMD_READ_SAFE
#define safe_for_write(cmd) [cmd] = CMD_WRITE_SAFE
static int verify_command(struct file *file, unsigned char *cmd)
static int verify_command(unsigned char *cmd, int has_write_perm)
{
static unsigned char cmd_type[256] = {
@ -193,18 +191,11 @@ static int verify_command(struct file *file, unsigned char *cmd)
safe_for_write(GPCMD_SET_STREAMING),
};
unsigned char type = cmd_type[cmd[0]];
int has_write_perm = 0;
/* Anybody who can open the device can do a read-safe command */
if (type & CMD_READ_SAFE)
return 0;
/*
* file can be NULL from ioctl_by_bdev()...
*/
if (file)
has_write_perm = file->f_mode & FMODE_WRITE;
/* Write-safe commands just require a writable open.. */
if ((type & CMD_WRITE_SAFE) && has_write_perm)
return 0;
@ -222,24 +213,104 @@ static int verify_command(struct file *file, unsigned char *cmd)
return -EPERM;
}
int blk_fill_sghdr_rq(request_queue_t *q, struct request *rq,
struct sg_io_hdr *hdr, int has_write_perm)
{
memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
if (copy_from_user(rq->cmd, hdr->cmdp, hdr->cmd_len))
return -EFAULT;
if (verify_command(rq->cmd, has_write_perm))
return -EPERM;
/*
* fill in request structure
*/
rq->cmd_len = hdr->cmd_len;
rq->cmd_type = REQ_TYPE_BLOCK_PC;
rq->timeout = (hdr->timeout * HZ) / 1000;
if (!rq->timeout)
rq->timeout = q->sg_timeout;
if (!rq->timeout)
rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
return 0;
}
EXPORT_SYMBOL_GPL(blk_fill_sghdr_rq);
/*
* unmap a request that was previously mapped to this sg_io_hdr. handles
* both sg and non-sg sg_io_hdr.
*/
int blk_unmap_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr)
{
struct bio *bio = rq->bio;
/*
* also releases request
*/
if (!hdr->iovec_count)
return blk_rq_unmap_user(bio, hdr->dxfer_len);
rq_for_each_bio(bio, rq)
bio_unmap_user(bio);
blk_put_request(rq);
return 0;
}
EXPORT_SYMBOL_GPL(blk_unmap_sghdr_rq);
int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
struct bio *bio)
{
int r, ret = 0;
/*
* fill in all the output members
*/
hdr->status = rq->errors & 0xff;
hdr->masked_status = status_byte(rq->errors);
hdr->msg_status = msg_byte(rq->errors);
hdr->host_status = host_byte(rq->errors);
hdr->driver_status = driver_byte(rq->errors);
hdr->info = 0;
if (hdr->masked_status || hdr->host_status || hdr->driver_status)
hdr->info |= SG_INFO_CHECK;
hdr->resid = rq->data_len;
hdr->sb_len_wr = 0;
if (rq->sense_len && hdr->sbp) {
int len = min((unsigned int) hdr->mx_sb_len, rq->sense_len);
if (!copy_to_user(hdr->sbp, rq->sense, len))
hdr->sb_len_wr = len;
else
ret = -EFAULT;
}
rq->bio = bio;
r = blk_unmap_sghdr_rq(rq, hdr);
if (ret)
r = ret;
return r;
}
EXPORT_SYMBOL_GPL(blk_complete_sghdr_rq);
static int sg_io(struct file *file, request_queue_t *q,
struct gendisk *bd_disk, struct sg_io_hdr *hdr)
{
unsigned long start_time, timeout;
int writing = 0, ret = 0;
unsigned long start_time;
int writing = 0, ret = 0, has_write_perm = 0;
struct request *rq;
char sense[SCSI_SENSE_BUFFERSIZE];
unsigned char cmd[BLK_MAX_CDB];
struct bio *bio;
if (hdr->interface_id != 'S')
return -EINVAL;
if (hdr->cmd_len > BLK_MAX_CDB)
return -EINVAL;
if (copy_from_user(cmd, hdr->cmdp, hdr->cmd_len))
return -EFAULT;
if (verify_command(file, cmd))
return -EPERM;
if (hdr->dxfer_len > (q->max_hw_sectors << 9))
return -EIO;
@ -260,25 +331,14 @@ static int sg_io(struct file *file, request_queue_t *q,
if (!rq)
return -ENOMEM;
/*
* fill in request structure
*/
rq->cmd_len = hdr->cmd_len;
memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
memcpy(rq->cmd, cmd, hdr->cmd_len);
if (file)
has_write_perm = file->f_mode & FMODE_WRITE;
memset(sense, 0, sizeof(sense));
rq->sense = sense;
rq->sense_len = 0;
rq->cmd_type = REQ_TYPE_BLOCK_PC;
timeout = msecs_to_jiffies(hdr->timeout);
rq->timeout = (timeout < INT_MAX) ? timeout : INT_MAX;
if (!rq->timeout)
rq->timeout = q->sg_timeout;
if (!rq->timeout)
rq->timeout = BLK_DEFAULT_TIMEOUT;
if (blk_fill_sghdr_rq(q, rq, hdr, has_write_perm)) {
blk_rq_unmap_user(bio, hdr->dxfer_len);
blk_put_request(rq);
return -EFAULT;
}
if (hdr->iovec_count) {
const int size = sizeof(struct sg_iovec) * hdr->iovec_count;
@ -306,6 +366,9 @@ static int sg_io(struct file *file, request_queue_t *q,
goto out;
bio = rq->bio;
memset(sense, 0, sizeof(sense));
rq->sense = sense;
rq->sense_len = 0;
rq->retries = 0;
start_time = jiffies;
@ -316,31 +379,9 @@ static int sg_io(struct file *file, request_queue_t *q,
*/
blk_execute_rq(q, bd_disk, rq, 0);
/* write to all output members */
hdr->status = 0xff & rq->errors;
hdr->masked_status = status_byte(rq->errors);
hdr->msg_status = msg_byte(rq->errors);
hdr->host_status = host_byte(rq->errors);
hdr->driver_status = driver_byte(rq->errors);
hdr->info = 0;
if (hdr->masked_status || hdr->host_status || hdr->driver_status)
hdr->info |= SG_INFO_CHECK;
hdr->resid = rq->data_len;
hdr->duration = ((jiffies - start_time) * 1000) / HZ;
hdr->sb_len_wr = 0;
if (rq->sense_len && hdr->sbp) {
int len = min((unsigned int) hdr->mx_sb_len, rq->sense_len);
if (!copy_to_user(hdr->sbp, rq->sense, len))
hdr->sb_len_wr = len;
}
if (blk_rq_unmap_user(bio))
ret = -EFAULT;
/* may not have succeeded, but output values written to control
* structure (struct sg_io_hdr). */
return blk_complete_sghdr_rq(rq, hdr, bio);
out:
blk_put_request(rq);
return ret;
@ -427,7 +468,7 @@ int sg_scsi_ioctl(struct file *file, struct request_queue *q,
if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
goto error;
err = verify_command(file, rq->cmd);
err = verify_command(rq->cmd, file->f_mode & FMODE_WRITE);
if (err)
goto error;
@ -454,7 +495,7 @@ int sg_scsi_ioctl(struct file *file, struct request_queue *q,
rq->retries = 1;
break;
default:
rq->timeout = BLK_DEFAULT_TIMEOUT;
rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
break;
}
@ -501,7 +542,7 @@ static int __blk_send_generic(request_queue_t *q, struct gendisk *bd_disk, int c
rq->cmd_type = REQ_TYPE_BLOCK_PC;
rq->data = NULL;
rq->data_len = 0;
rq->timeout = BLK_DEFAULT_TIMEOUT;
rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
memset(rq->cmd, 0, sizeof(rq->cmd));
rq->cmd[0] = cmd;
rq->cmd[4] = data;

29
drivers/ide/ide-floppy.c
View File

@ -1258,19 +1258,25 @@ static void idefloppy_create_rw_cmd (idefloppy_floppy_t *floppy, idefloppy_pc_t
set_bit(PC_DMA_RECOMMENDED, &pc->flags);
}
static int
static void
idefloppy_blockpc_cmd(idefloppy_floppy_t *floppy, idefloppy_pc_t *pc, struct request *rq)
{
/*
* just support eject for now, it would not be hard to make the
* REQ_BLOCK_PC support fully-featured
*/
if (rq->cmd[0] != IDEFLOPPY_START_STOP_CMD)
return 1;
idefloppy_init_pc(pc);
pc->callback = &idefloppy_rw_callback;
memcpy(pc->c, rq->cmd, sizeof(pc->c));
return 0;
pc->rq = rq;
pc->b_count = rq->data_len;
if (rq->data_len && rq_data_dir(rq) == WRITE)
set_bit(PC_WRITING, &pc->flags);
pc->buffer = rq->data;
if (rq->bio)
set_bit(PC_DMA_RECOMMENDED, &pc->flags);
/*
* possibly problematic, doesn't look like ide-floppy correctly
* handled scattered requests if dma fails...
*/
pc->request_transfer = pc->buffer_size = rq->data_len;
}
/*
@ -1317,10 +1323,7 @@ static ide_startstop_t idefloppy_do_request (ide_drive_t *drive, struct request
pc = (idefloppy_pc_t *) rq->buffer;
} else if (blk_pc_request(rq)) {
pc = idefloppy_next_pc_storage(drive);
if (idefloppy_blockpc_cmd(floppy, pc, rq)) {
idefloppy_do_end_request(drive, 0, 0);
return ide_stopped;
}
idefloppy_blockpc_cmd(floppy, pc, rq);
} else {
blk_dump_rq_flags(rq,
"ide-floppy: unsupported command in queue");

10
drivers/ide/ide.c
View File

@ -1049,9 +1049,13 @@ int generic_ide_ioctl(ide_drive_t *drive, struct file *file, struct block_device
unsigned long flags;
ide_driver_t *drv;
void __user *p = (void __user *)arg;
int err = 0, (*setfunc)(ide_drive_t *, int);
int err, (*setfunc)(ide_drive_t *, int);
u8 *val;
err = scsi_cmd_ioctl(file, bdev->bd_disk, cmd, p);
if (err != -ENOTTY)
return err;
switch (cmd) {
case HDIO_GET_32BIT: val = &drive->io_32bit; goto read_val;
case HDIO_GET_KEEPSETTINGS: val = &drive->keep_settings; goto read_val;
@ -1171,10 +1175,6 @@ int generic_ide_ioctl(ide_drive_t *drive, struct file *file, struct block_device
return 0;
}
case CDROMEJECT:
case CDROMCLOSETRAY:
return scsi_cmd_ioctl(file, bdev->bd_disk, cmd, p);
case HDIO_GET_BUSSTATE:
if (!capable(CAP_SYS_ADMIN))
return -EACCES;

12
include/linux/blkdev.h
View File

@ -41,6 +41,8 @@ struct elevator_queue;
typedef struct elevator_queue elevator_t;
struct request_pm_state;
struct blk_trace;
struct request;
struct sg_io_hdr;
#define BLKDEV_MIN_RQ 4
#define BLKDEV_MAX_RQ 128 /* Default maximum */
@ -607,6 +609,11 @@ extern unsigned long blk_max_low_pfn, blk_max_pfn;
#define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
/*
* default timeout for SG_IO if none specified
*/
#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
#ifdef CONFIG_MMU
extern int init_emergency_isa_pool(void);
extern void blk_queue_bounce(request_queue_t *q, struct bio **bio);
@ -680,6 +687,11 @@ extern int blk_execute_rq(request_queue_t *, struct gendisk *,
struct request *, int);
extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *,
struct request *, int, rq_end_io_fn *);
extern int blk_fill_sghdr_rq(request_queue_t *, struct request *,
struct sg_io_hdr *, int);
extern int blk_unmap_sghdr_rq(struct request *, struct sg_io_hdr *);
extern int blk_complete_sghdr_rq(struct request *, struct sg_io_hdr *,
struct bio *);
static inline request_queue_t *bdev_get_queue(struct block_device *bdev)
{

21
include/linux/bsg.h Normal file
View File

@ -0,0 +1,21 @@
#ifndef BSG_H
#define BSG_H
#if defined(CONFIG_BLK_DEV_BSG)
struct bsg_class_device {
struct class_device *class_dev;
struct device *dev;
int minor;
struct gendisk *disk;
struct list_head list;
};
extern int bsg_register_disk(struct gendisk *);
extern void bsg_unregister_disk(struct gendisk *);
#else
struct bsg_class_device { };
#define bsg_register_disk(disk) (0)
#define bsg_unregister_disk(disk) do { } while (0)
#endif
#endif

2
include/linux/genhd.h
View File

@ -67,6 +67,7 @@ struct partition {
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/workqueue.h>
#include <linux/bsg.h>
struct partition {
unsigned char boot_ind; /* 0x80 - active */
@ -91,6 +92,7 @@ struct hd_struct {
#ifdef CONFIG_FAIL_MAKE_REQUEST
int make_it_fail;
#endif
struct bsg_class_device bsg_dev;
};
#define GENHD_FL_REMOVABLE 1