| /* |
| * 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/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/scsi_device.h> |
| #include <scsi/scsi_driver.h> |
| #include <scsi/sg.h> |
| |
| static char bsg_version[] = "block layer sg (bsg) 0.4"; |
| |
| struct bsg_device { |
| 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; |
| wait_queue_head_t wq_done; |
| wait_queue_head_t wq_free; |
| char name[BUS_ID_SIZE]; |
| int max_queue; |
| unsigned long flags; |
| }; |
| |
| enum { |
| BSG_F_BLOCK = 1, |
| BSG_F_WRITE_PERM = 2, |
| }; |
| |
| #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, __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, 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]; |
| |
| static struct class *bsg_class; |
| static LIST_HEAD(bsg_class_list); |
| |
| 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; |
| int err; |
| struct sg_io_v4 hdr; |
| struct sg_io_v4 __user *uhdr; |
| 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 = NULL; |
| |
| 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_alloc(bsg_cmd_cachep, GFP_USER); |
| if (unlikely(!bc)) { |
| spin_lock_irq(&bd->lock); |
| bd->queued_cmds--; |
| goto out; |
| } |
| |
| memset(bc, 0, sizeof(*bc)); |
| bc->bd = bd; |
| INIT_LIST_HEAD(&bc->list); |
| dprintk("%s: returning free cmd %p\n", bd->name, bc); |
| return bc; |
| out: |
| 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; |
| } |
| |
| static int blk_fill_sgv4_hdr_rq(request_queue_t *q, struct request *rq, |
| struct sg_io_v4 *hdr, int has_write_perm) |
| { |
| memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */ |
| |
| if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request, |
| hdr->request_len)) |
| return -EFAULT; |
| if (blk_verify_command(rq->cmd, has_write_perm)) |
| return -EPERM; |
| |
| /* |
| * fill in request structure |
| */ |
| rq->cmd_len = hdr->request_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; |
| } |
| |
| /* |
| * Check if sg_io_v4 from user is allowed and valid |
| */ |
| static int |
| bsg_validate_sgv4_hdr(request_queue_t *q, struct sg_io_v4 *hdr, int *rw) |
| { |
| if (hdr->guard != 'Q') |
| return -EINVAL; |
| if (hdr->request_len > BLK_MAX_CDB) |
| return -EINVAL; |
| if (hdr->dout_xfer_len > (q->max_sectors << 9) || |
| hdr->din_xfer_len > (q->max_sectors << 9)) |
| return -EIO; |
| |
| /* not supported currently */ |
| if (hdr->protocol || hdr->subprotocol) |
| return -EINVAL; |
| |
| /* |
| * looks sane, if no data then it should be fine from our POV |
| */ |
| if (!hdr->dout_xfer_len && !hdr->din_xfer_len) |
| return 0; |
| |
| /* not supported currently */ |
| if (hdr->dout_xfer_len && hdr->din_xfer_len) |
| return -EINVAL; |
| |
| *rw = hdr->dout_xfer_len ? WRITE : READ; |
| |
| return 0; |
| } |
| |
| /* |
| * map sg_io_v4 to a request. |
| */ |
| static struct request * |
| bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr) |
| { |
| request_queue_t *q = bd->queue; |
| struct request *rq; |
| int ret, rw = 0; /* shut up gcc */ |
| unsigned int dxfer_len; |
| void *dxferp = NULL; |
| |
| 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 seperately and string them to request |
| */ |
| rq = blk_get_request(q, rw, GFP_KERNEL); |
| ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, test_bit(BSG_F_WRITE_PERM, |
| &bd->flags)); |
| if (ret) { |
| blk_put_request(rq); |
| return ERR_PTR(ret); |
| } |
| |
| 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, dxferp, dxfer_len); |
| if (ret) { |
| dprintk("failed map at %d\n", ret); |
| blk_put_request(rq); |
| 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 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_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, NULL, 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 blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr, |
| struct bio *bio) |
| { |
| int ret = 0; |
| |
| dprintk("rq %p bio %p %u\n", rq, bio, rq->errors); |
| /* |
| * fill in all the output members |
| */ |
| hdr->device_status = status_byte(rq->errors); |
| 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->din_resid = rq->data_len; |
| hdr->response_len = 0; |
| |
| if (rq->sense_len && hdr->response) { |
| int len = min((unsigned int) hdr->max_response_len, |
| rq->sense_len); |
| |
| ret = copy_to_user((void*)(unsigned long)hdr->response, |
| rq->sense, len); |
| if (!ret) |
| hdr->response_len = len; |
| else |
| ret = -EFAULT; |
| } |
| |
| blk_rq_unmap_user(bio); |
| 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); |
| |
| 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_sgv4_hdr_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_v4)) |
| return -EINVAL; |
| |
| ret = 0; |
| nr_commands = count / sizeof(struct sg_io_v4); |
| 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_sgv4_hdr_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_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); |
| } |
| |
| 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 %Zd 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_v4)) |
| return -EINVAL; |
| |
| nr_commands = count / sizeof(struct sg_io_v4); |
| rq = NULL; |
| bc = NULL; |
| ret = 0; |
| while (nr_commands) { |
| request_queue_t *q = bd->queue; |
| |
| bc = bsg_get_command(bd); |
| if (!bc) |
| break; |
| if (IS_ERR(bc)) { |
| ret = PTR_ERR(bc); |
| bc = NULL; |
| break; |
| } |
| |
| bc->uhdr = (struct sg_io_v4 __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, &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_v4); |
| *bytes_read += 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_read; |
| int ret; |
| |
| dprintk("%s: write %Zd bytes\n", bd->name, count); |
| |
| bsg_set_block(bd, file); |
| bsg_set_write_perm(bd, file); |
| |
| bytes_read = 0; |
| ret = __bsg_write(bd, buf, count, &bytes_read); |
| *ppos = bytes_read; |
| |
| /* |
| * return bytes written on non-fatal errors |
| */ |
| if (!bytes_read || (bytes_read && err_block_err(ret))) |
| bytes_read = ret; |
| |
| dprintk("%s: returning %Zd\n", bd->name, bytes_read); |
| return bytes_read; |
| } |
| |
| 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 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); |
| kfree(bd); |
| out: |
| mutex_unlock(&bsg_mutex); |
| return ret; |
| } |
| |
| static struct bsg_device *bsg_add_device(struct inode *inode, |
| struct request_queue *rq, |
| 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->queue = rq; |
| kobject_get(&rq->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, rq->bsg_dev.class_dev->class_id, 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 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->queue, 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 < 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(file, bd->queue, NULL, cmd, uarg); |
| } |
| case SG_IO: { |
| struct request *rq; |
| struct bio *bio; |
| struct sg_io_v4 hdr; |
| |
| if (copy_from_user(&hdr, uarg, sizeof(hdr))) |
| return -EFAULT; |
| |
| rq = bsg_map_hdr(bd, &hdr); |
| if (IS_ERR(rq)) |
| return PTR_ERR(rq); |
| |
| bio = rq->bio; |
| blk_execute_rq(bd->queue, NULL, rq, 0); |
| blk_complete_sgv4_hdr_rq(rq, &hdr, bio); |
| |
| if (copy_to_user(uarg, &hdr, sizeof(hdr))) |
| return -EFAULT; |
| |
| return 0; |
| } |
| /* |
| * 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_queue(struct request_queue *q) |
| { |
| struct bsg_class_device *bcd = &q->bsg_dev; |
| |
| if (!bcd->class_dev) |
| return; |
| |
| mutex_lock(&bsg_mutex); |
| sysfs_remove_link(&q->kobj, "bsg"); |
| class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor)); |
| bcd->class_dev = NULL; |
| list_del_init(&bcd->list); |
| bsg_device_nr--; |
| mutex_unlock(&bsg_mutex); |
| } |
| EXPORT_SYMBOL_GPL(bsg_unregister_queue); |
| |
| int bsg_register_queue(struct request_queue *q, const char *name) |
| { |
| struct bsg_class_device *bcd, *__bcd; |
| dev_t dev; |
| int ret = -EMFILE; |
| struct class_device *class_dev = NULL; |
| |
| /* |
| * 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)); |
| INIT_LIST_HEAD(&bcd->list); |
| |
| mutex_lock(&bsg_mutex); |
| if (bsg_device_nr == BSG_MAX_DEVS) { |
| printk(KERN_ERR "bsg: too many bsg devices\n"); |
| goto err; |
| } |
| |
| retry: |
| list_for_each_entry(__bcd, &bsg_class_list, list) { |
| if (__bcd->minor == bsg_minor_idx) { |
| bsg_minor_idx++; |
| if (bsg_minor_idx == BSG_MAX_DEVS) |
| bsg_minor_idx = 0; |
| goto retry; |
| } |
| } |
| |
| bcd->minor = bsg_minor_idx++; |
| if (bsg_minor_idx == BSG_MAX_DEVS) |
| bsg_minor_idx = 0; |
| |
| bcd->queue = q; |
| 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); |
| goto err; |
| } |
| bcd->class_dev = class_dev; |
| |
| if (q->kobj.dentry) { |
| ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg"); |
| if (ret) |
| goto err; |
| } |
| |
| list_add_tail(&bcd->list, &bsg_class_list); |
| bsg_device_nr++; |
| |
| mutex_unlock(&bsg_mutex); |
| return 0; |
| err: |
| if (class_dev) |
| class_device_destroy(bsg_class, MKDEV(BSG_MAJOR, bcd->minor)); |
| mutex_unlock(&bsg_mutex); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(bsg_register_queue); |
| |
| static int bsg_add(struct class_device *cl_dev, struct class_interface *cl_intf) |
| { |
| int ret; |
| struct scsi_device *sdp = to_scsi_device(cl_dev->dev); |
| struct request_queue *rq = sdp->request_queue; |
| |
| if (rq->kobj.parent) |
| ret = bsg_register_queue(rq, kobject_name(rq->kobj.parent)); |
| else |
| ret = bsg_register_queue(rq, kobject_name(&sdp->sdev_gendev.kobj)); |
| return ret; |
| } |
| |
| static void bsg_remove(struct class_device *cl_dev, struct class_interface *cl_intf) |
| { |
| bsg_unregister_queue(to_scsi_device(cl_dev->dev)->request_queue); |
| } |
| |
| static struct class_interface bsg_intf = { |
| .add = bsg_add, |
| .remove = bsg_remove, |
| }; |
| |
| static struct cdev bsg_cdev = { |
| .kobj = {.name = "bsg", }, |
| .owner = THIS_MODULE, |
| }; |
| |
| static int __init bsg_init(void) |
| { |
| int ret, i; |
| |
| bsg_cmd_cachep = kmem_cache_create("bsg_cmd", |
| sizeof(struct bsg_command), 0, 0, NULL, NULL); |
| if (!bsg_cmd_cachep) { |
| printk(KERN_ERR "bsg: failed creating slab cache\n"); |
| return -ENOMEM; |
| } |
| |
| 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)) { |
| kmem_cache_destroy(bsg_cmd_cachep); |
| return PTR_ERR(bsg_class); |
| } |
| |
| 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; |
| } |
| |
| 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 = 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; |
| } |
| |
| 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"); |
| |
| device_initcall(bsg_init); |