| /* |
| * 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; |
| }; |
| |
| 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 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) |
| { |
| 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, has_write_perm)) |
| 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 has_write_perm) |
| { |
| 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); |
| |
| 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(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; |
| scsi_req_init(rq); |
| |
| ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm); |
| 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, 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) |
| { |
| struct scsi_request *req = scsi_req(rq); |
| 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 (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 && rq->errors < 0) |
| ret = rq->errors; |
| |
| 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; |
| |
| dprintk("%s: entered\n", bd->name); |
| |
| /* |
| * 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; |
| |
| 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 || 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); |
| 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); |
| |
| 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 & FMODE_WRITE); |
| |
| *ppos = bytes_written; |
| |
| /* |
| * return bytes written on non-fatal errors |
| */ |
| if (!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; |
| #ifdef BSG_DEBUG |
| unsigned char buf[32]; |
| #endif |
| 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); |
| 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; |
| |
| 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 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; |
| |
| if (copy_from_user(&hdr, uarg, sizeof(hdr))) |
| return -EFAULT; |
| |
| rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE); |
| 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; |
| 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); |