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- /*
- * 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"
- 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
- #undef BSG_DEBUG
- #ifdef BSG_DEBUG
- #define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ##args)
- #else
- #define dprintk(fmt, args...)
- #endif
- 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;
- char sense[SCSI_SENSE_BUFFERSIZE];
- };
- 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);
- dprintk("%s: returning free cmd %p\n", bd->name, 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 bsg_io_schedule(struct bsg_device *bd)
- {
- 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, TASK_UNINTERRUPTIBLE);
- spin_unlock_irq(&bd->lock);
- io_schedule();
- finish_wait(&bd->wq_done, &wait);
- return ret;
- unlock:
- spin_unlock_irq(&bd->lock);
- return ret;
- }
- 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 has_write_perm)
- {
- if (hdr->request_len > BLK_MAX_CDB) {
- rq->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
- if (!rq->cmd)
- return -ENOMEM;
- }
- if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request,
- hdr->request_len))
- return -EFAULT;
- if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
- if (blk_verify_command(rq->cmd, has_write_perm))
- return -EPERM;
- } else if (!capable(CAP_SYS_RAWIO))
- return -EPERM;
- /*
- * fill in request structure
- */
- rq->cmd_len = hdr->request_len;
- rq->cmd_type = REQ_TYPE_BLOCK_PC;
- 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 request_queue *q, struct sg_io_v4 *hdr, int *rw)
- {
- 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;
- }
- *rw = hdr->dout_xfer_len ? WRITE : READ;
- 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 has_write_perm,
- u8 *sense)
- {
- struct request_queue *q = bd->queue;
- struct request *rq, *next_rq = NULL;
- int ret, rw;
- unsigned int dxfer_len;
- void *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);
- dprintk("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(q, hdr, &rw);
- if (ret)
- return ERR_PTR(ret);
- /*
- * map scatter-gather elements separately and string them to request
- */
- rq = blk_get_request(q, rw, GFP_KERNEL);
- if (!rq)
- return ERR_PTR(-ENOMEM);
- ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
- if (ret)
- goto out;
- if (rw == WRITE && hdr->din_xfer_len) {
- if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
- ret = -EOPNOTSUPP;
- goto out;
- }
- next_rq = blk_get_request(q, READ, GFP_KERNEL);
- if (!next_rq) {
- ret = -ENOMEM;
- goto out;
- }
- rq->next_rq = next_rq;
- next_rq->cmd_type = rq->cmd_type;
- dxferp = (void*)(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*)(unsigned long)hdr->dout_xferp;
- } else if (hdr->din_xfer_len) {
- dxfer_len = hdr->din_xfer_len;
- dxferp = (void*)(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;
- }
- rq->sense = sense;
- rq->sense_len = 0;
- return rq;
- out:
- if (rq->cmd != rq->__cmd)
- kfree(rq->cmd);
- 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, int uptodate)
- {
- struct bsg_command *bc = rq->end_io_data;
- struct bsg_device *bd = bc->bd;
- unsigned long flags;
- dprintk("%s: finished rq %p bc %p, bio %p stat %d\n",
- bd->name, rq, bc, bc->bio, uptodate);
- 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);
- dprintk("%s: queueing rq %p, bc %p\n", bd->name, 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);
- dprintk("%s: returning done %p\n", bd->name, 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)
- {
- int ret = 0;
- dprintk("rq %p bio %p 0x%x\n", rq, bio, rq->errors);
- /*
- * fill in all the output members
- */
- hdr->device_status = rq->errors & 0xff;
- hdr->transport_status = host_byte(rq->errors);
- hdr->driver_status = driver_byte(rq->errors);
- hdr->info = 0;
- if (hdr->device_status || hdr->transport_status || hdr->driver_status)
- hdr->info |= SG_INFO_CHECK;
- hdr->response_len = 0;
- if (rq->sense_len && hdr->response) {
- 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 (!ret)
- hdr->response_len = len;
- else
- ret = -EFAULT;
- }
- if (rq->next_rq) {
- hdr->dout_resid = rq->resid_len;
- hdr->din_resid = 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 = rq->resid_len;
- else
- hdr->dout_resid = rq->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 && rq->errors < 0)
- ret = rq->errors;
- blk_rq_unmap_user(bio);
- if (rq->cmd != rq->__cmd)
- kfree(rq->cmd);
- blk_put_request(rq);
- return ret;
- }
- static int bsg_complete_all_commands(struct bsg_device *bd)
- {
- struct bsg_command *bc;
- int ret, tret;
- dprintk("%s: entered\n", bd->name);
- /*
- * wait for all commands to complete
- */
- ret = 0;
- do {
- 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 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 {
- 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;
- dprintk("%s: read %Zd bytes\n", bd->name, count);
- bsg_set_block(bd, file);
- bytes_read = 0;
- ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
- *ppos = bytes_read;
- if (!bytes_read || (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 has_write_perm)
- {
- 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, has_write_perm, bc->sense);
- 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;
- dprintk("%s: write %Zd bytes\n", bd->name, count);
- bsg_set_block(bd, file);
- bytes_written = 0;
- ret = __bsg_write(bd, buf, count, &bytes_written,
- file->f_mode & FMODE_WRITE);
- *ppos = bytes_written;
- /*
- * return bytes written on non-fatal errors
- */
- if (!bytes_written || (bytes_written && err_block_err(ret)))
- bytes_written = ret;
- dprintk("%s: returning %Zd\n", bd->name, 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);
- 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);
- 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;
- int ret;
- #ifdef BSG_DEBUG
- unsigned char buf[32];
- #endif
- ret = blk_get_queue(rq);
- if (ret)
- 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);
- dprintk("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;
- struct hlist_node *entry;
- mutex_lock(&bsg_mutex);
- hlist_for_each_entry(bd, entry, 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 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 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;
- u8 sense[SCSI_SENSE_BUFFERSIZE];
- if (copy_from_user(&hdr, uarg, sizeof(hdr)))
- return -EFAULT;
- rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE, sense);
- 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;
- }
- /*
- * block device ioctls
- */
- default:
- #if 0
- return ioctl_by_bdev(bd->bdev, cmd, arg);
- #else
- return -ENOTTY;
- #endif
- }
- }
- 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, minor;
- 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 (!q->request_fn)
- return 0;
- bcd = &q->bsg_dev;
- memset(bcd, 0, sizeof(*bcd));
- mutex_lock(&bsg_mutex);
- ret = idr_pre_get(&bsg_minor_idr, GFP_KERNEL);
- if (!ret) {
- ret = -ENOMEM;
- goto unlock;
- }
- 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;
- 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);
- remove_idr:
- idr_remove(&bsg_minor_idr, 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, mode_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);
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