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block/bsg.c
23.5 KB
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/* |
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* bsg.c - block layer implementation of the sg v4 interface |
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* * 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. * */ |
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#include <linux/module.h> #include <linux/init.h> #include <linux/file.h> #include <linux/blkdev.h> #include <linux/poll.h> #include <linux/cdev.h> |
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#include <linux/jiffies.h> |
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#include <linux/percpu.h> #include <linux/uio.h> |
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#include <linux/idr.h> |
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#include <linux/bsg.h> |
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#include <linux/smp_lock.h> |
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#include <linux/slab.h> |
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#include <scsi/scsi.h> #include <scsi/scsi_ioctl.h> #include <scsi/scsi_cmnd.h> |
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#include <scsi/scsi_device.h> #include <scsi/scsi_driver.h> |
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#include <scsi/sg.h> |
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#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver" #define BSG_VERSION "0.4" |
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struct bsg_device { |
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struct request_queue *queue; |
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spinlock_t lock; struct list_head busy_list; struct list_head done_list; struct hlist_node dev_list; atomic_t ref_count; |
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int queued_cmds; int done_cmds; |
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wait_queue_head_t wq_done; wait_queue_head_t wq_free; |
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char name[20]; |
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int max_queue; unsigned long flags; }; enum { BSG_F_BLOCK = 1, |
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}; |
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#define BSG_DEFAULT_CMDS 64 |
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#define BSG_MAX_DEVS 32768 |
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#undef BSG_DEBUG #ifdef BSG_DEBUG |
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#define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ##args) |
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#else #define dprintk(fmt, args...) #endif |
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static DEFINE_MUTEX(bsg_mutex); |
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static DEFINE_IDR(bsg_minor_idr); |
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#define BSG_LIST_ARRAY_SIZE 8 |
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static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE]; |
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static struct class *bsg_class; |
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static int bsg_major; |
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|
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static struct kmem_cache *bsg_cmd_cachep; |
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/* * our internal command type */ struct bsg_command { struct bsg_device *bd; struct list_head list; struct request *rq; struct bio *bio; |
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struct bio *bidi_bio; |
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int err; |
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struct sg_io_v4 hdr; |
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char sense[SCSI_SENSE_BUFFERSIZE]; }; static void bsg_free_command(struct bsg_command *bc) { struct bsg_device *bd = bc->bd; |
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unsigned long flags; |
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kmem_cache_free(bsg_cmd_cachep, bc); |
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spin_lock_irqsave(&bd->lock, flags); bd->queued_cmds--; |
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spin_unlock_irqrestore(&bd->lock, flags); wake_up(&bd->wq_free); } |
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static struct bsg_command *bsg_alloc_command(struct bsg_device *bd) |
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{ |
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struct bsg_command *bc = ERR_PTR(-EINVAL); |
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spin_lock_irq(&bd->lock); if (bd->queued_cmds >= bd->max_queue) goto out; |
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bd->queued_cmds++; |
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spin_unlock_irq(&bd->lock); |
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bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL); |
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if (unlikely(!bc)) { spin_lock_irq(&bd->lock); |
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bd->queued_cmds--; |
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bc = ERR_PTR(-ENOMEM); |
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goto out; |
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} |
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bc->bd = bd; INIT_LIST_HEAD(&bc->list); |
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dprintk("%s: returning free cmd %p ", bd->name, bc); |
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return bc; out: |
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spin_unlock_irq(&bd->lock); return bc; } |
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static inline struct hlist_head *bsg_dev_idx_hash(int index) |
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{ |
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return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)]; |
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} |
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static int bsg_io_schedule(struct bsg_device *bd) |
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{ 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; } |
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prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE); |
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spin_unlock_irq(&bd->lock); io_schedule(); finish_wait(&bd->wq_done, &wait); |
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return ret; unlock: spin_unlock_irq(&bd->lock); return ret; } |
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static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq, |
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struct sg_io_v4 *hdr, struct bsg_device *bd, |
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fmode_t has_write_perm) |
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{ |
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if (hdr->request_len > BLK_MAX_CDB) { rq->cmd = kzalloc(hdr->request_len, GFP_KERNEL); if (!rq->cmd) return -ENOMEM; } |
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if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request, hdr->request_len)) return -EFAULT; |
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if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) { |
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if (blk_verify_command(rq->cmd, has_write_perm)) |
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return -EPERM; } else if (!capable(CAP_SYS_RAWIO)) |
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return -EPERM; /* * fill in request structure */ rq->cmd_len = hdr->request_len; rq->cmd_type = REQ_TYPE_BLOCK_PC; |
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rq->timeout = msecs_to_jiffies(hdr->timeout); |
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if (!rq->timeout) rq->timeout = q->sg_timeout; if (!rq->timeout) rq->timeout = BLK_DEFAULT_SG_TIMEOUT; |
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if (rq->timeout < BLK_MIN_SG_TIMEOUT) rq->timeout = BLK_MIN_SG_TIMEOUT; |
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return 0; } |
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/* |
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* Check if sg_io_v4 from user is allowed and valid |
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*/ static int |
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bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw) |
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{ |
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int ret = 0; |
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if (hdr->guard != 'Q') |
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return -EINVAL; |
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|
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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; } |
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*rw = hdr->dout_xfer_len ? WRITE : READ; |
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return ret; |
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} /* |
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* map sg_io_v4 to a request. |
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*/ static struct request * |
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bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm, u8 *sense) |
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{ |
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struct request_queue *q = bd->queue; |
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struct request *rq, *next_rq = NULL; |
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int ret, rw; |
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unsigned int dxfer_len; void *dxferp = NULL; |
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dprintk("map hdr %llx/%u %llx/%u ", (unsigned long long) hdr->dout_xferp, hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp, hdr->din_xfer_len); |
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ret = bsg_validate_sgv4_hdr(q, hdr, &rw); |
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if (ret) return ERR_PTR(ret); /* |
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* map scatter-gather elements separately and string them to request |
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*/ rq = blk_get_request(q, rw, GFP_KERNEL); |
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if (!rq) return ERR_PTR(-ENOMEM); |
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ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm); |
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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; |
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next_rq->cmd_type = rq->cmd_type; |
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dxferp = (void*)(unsigned long)hdr->din_xferp; |
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ret = blk_rq_map_user(q, next_rq, NULL, dxferp, hdr->din_xfer_len, GFP_KERNEL); |
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if (ret) goto out; |
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} |
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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) { |
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ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len, GFP_KERNEL); |
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if (ret) goto out; |
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} |
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rq->sense = sense; rq->sense_len = 0; |
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return rq; |
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out: |
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if (rq->cmd != rq->__cmd) kfree(rq->cmd); |
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blk_put_request(rq); if (next_rq) { blk_rq_unmap_user(next_rq->bio); blk_put_request(next_rq); } return ERR_PTR(ret); |
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} /* * 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; |
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dprintk("%s: finished rq %p bc %p, bio %p stat %d ", bd->name, rq, bc, bc->bio, uptodate); |
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bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration); spin_lock_irqsave(&bd->lock, flags); |
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list_move_tail(&bc->list, &bd->done_list); bd->done_cmds++; |
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spin_unlock_irqrestore(&bd->lock, flags); |
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wake_up(&bd->wq_done); |
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} /* * do final setup of a 'bc' and submit the matching 'rq' to the block * layer for io */ |
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static void bsg_add_command(struct bsg_device *bd, struct request_queue *q, |
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struct bsg_command *bc, struct request *rq) { |
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int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL)); |
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/* * add bc command to busy queue and submit rq for io */ bc->rq = rq; bc->bio = rq->bio; |
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if (rq->next_rq) bc->bidi_bio = rq->next_rq->bio; |
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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 ", bd->name, rq, bc); rq->end_io_data = bc; |
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blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io); |
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} |
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static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd) |
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{ struct bsg_command *bc = NULL; spin_lock_irq(&bd->lock); if (bd->done_cmds) { |
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bc = list_first_entry(&bd->done_list, struct bsg_command, list); |
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list_del(&bc->list); bd->done_cmds--; |
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} spin_unlock_irq(&bd->lock); return bc; } /* * Get a finished command from the done list */ |
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static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd) |
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{ struct bsg_command *bc; int ret; do { bc = bsg_next_done_cmd(bd); if (bc) break; |
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if (!test_bit(BSG_F_BLOCK, &bd->flags)) { bc = ERR_PTR(-EAGAIN); break; } ret = wait_event_interruptible(bd->wq_done, bd->done_cmds); |
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if (ret) { |
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bc = ERR_PTR(-ERESTARTSYS); |
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break; } } while (1); dprintk("%s: returning done %p ", bd->name, bc); return bc; } |
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static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr, |
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struct bio *bio, struct bio *bidi_bio) |
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{ int ret = 0; |
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dprintk("rq %p bio %p 0x%x ", rq, bio, rq->errors); |
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/* * 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; |
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hdr->response_len = 0; if (rq->sense_len && hdr->response) { |
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int len = min_t(unsigned int, hdr->max_response_len, rq->sense_len); |
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ret = copy_to_user((void*)(unsigned long)hdr->response, rq->sense, len); if (!ret) hdr->response_len = len; else ret = -EFAULT; } |
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if (rq->next_rq) { |
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hdr->dout_resid = rq->resid_len; hdr->din_resid = rq->next_rq->resid_len; |
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blk_rq_unmap_user(bidi_bio); blk_put_request(rq->next_rq); |
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} else if (rq_data_dir(rq) == READ) |
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hdr->din_resid = rq->resid_len; |
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else |
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hdr->dout_resid = rq->resid_len; |
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|
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/* * 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; |
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blk_rq_unmap_user(bio); |
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if (rq->cmd != rq->__cmd) kfree(rq->cmd); |
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blk_put_request(rq); return ret; } |
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static int bsg_complete_all_commands(struct bsg_device *bd) { struct bsg_command *bc; int ret, tret; dprintk("%s: entered ", bd->name); |
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/* * wait for all commands to complete */ ret = 0; do { |
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ret = bsg_io_schedule(bd); |
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/* * 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 { |
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spin_lock_irq(&bd->lock); if (!bd->queued_cmds) { spin_unlock_irq(&bd->lock); |
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break; } |
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spin_unlock_irq(&bd->lock); |
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bc = bsg_get_done_cmd(bd); if (IS_ERR(bc)) break; |
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tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio, bc->bidi_bio); |
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if (!ret) ret = tret; bsg_free_command(bc); } while (1); return ret; } |
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static int |
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__bsg_read(char __user *buf, size_t count, struct bsg_device *bd, const struct iovec *iov, ssize_t *bytes_read) |
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{ struct bsg_command *bc; int nr_commands, ret; |
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if (count % sizeof(struct sg_io_v4)) |
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return -EINVAL; ret = 0; |
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nr_commands = count / sizeof(struct sg_io_v4); |
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while (nr_commands) { |
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bc = bsg_get_done_cmd(bd); |
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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 */ |
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ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio, bc->bidi_bio); |
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if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr))) |
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|
528 529 530 531 532 533 |
ret = -EFAULT; bsg_free_command(bc); if (ret) break; |
70e36ecea
|
534 535 |
buf += sizeof(struct sg_io_v4); *bytes_read += sizeof(struct sg_io_v4); |
3d6392cfb
|
536 537 538 539 540 541 542 543 544 545 546 547 548 |
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); } |
25fd16430
|
549 550 551 |
/* * Check if the error is a "real" error that we should return. */ |
3d6392cfb
|
552 553 554 555 556 557 558 559 560 561 562 563 564 565 |
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; |
9e69fbb53
|
566 567 |
dprintk("%s: read %Zd bytes ", bd->name, count); |
3d6392cfb
|
568 569 |
bsg_set_block(bd, file); |
0b07de85a
|
570 |
|
3d6392cfb
|
571 |
bytes_read = 0; |
e7d721732
|
572 |
ret = __bsg_read(buf, count, bd, NULL, &bytes_read); |
3d6392cfb
|
573 574 575 576 577 578 579 |
*ppos = bytes_read; if (!bytes_read || (bytes_read && err_block_err(ret))) bytes_read = ret; return bytes_read; } |
25fd16430
|
580 |
static int __bsg_write(struct bsg_device *bd, const char __user *buf, |
aeb5d7270
|
581 582 |
size_t count, ssize_t *bytes_written, fmode_t has_write_perm) |
3d6392cfb
|
583 584 585 586 |
{ struct bsg_command *bc; struct request *rq; int ret, nr_commands; |
70e36ecea
|
587 |
if (count % sizeof(struct sg_io_v4)) |
3d6392cfb
|
588 |
return -EINVAL; |
70e36ecea
|
589 |
nr_commands = count / sizeof(struct sg_io_v4); |
3d6392cfb
|
590 591 592 593 |
rq = NULL; bc = NULL; ret = 0; while (nr_commands) { |
165125e1e
|
594 |
struct request_queue *q = bd->queue; |
3d6392cfb
|
595 |
|
e7d721732
|
596 |
bc = bsg_alloc_command(bd); |
3d6392cfb
|
597 598 599 600 601 |
if (IS_ERR(bc)) { ret = PTR_ERR(bc); bc = NULL; break; } |
3d6392cfb
|
602 603 604 605 606 607 608 609 |
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 */ |
c1c201200
|
610 |
rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm, bc->sense); |
3d6392cfb
|
611 612 613 614 615 616 617 618 619 620 |
if (IS_ERR(rq)) { ret = PTR_ERR(rq); rq = NULL; break; } bsg_add_command(bd, q, bc, rq); bc = NULL; rq = NULL; nr_commands--; |
70e36ecea
|
621 |
buf += sizeof(struct sg_io_v4); |
25fd16430
|
622 |
*bytes_written += sizeof(struct sg_io_v4); |
3d6392cfb
|
623 |
} |
3d6392cfb
|
624 625 626 627 628 629 630 631 632 633 |
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; |
25fd16430
|
634 |
ssize_t bytes_written; |
3d6392cfb
|
635 |
int ret; |
9e69fbb53
|
636 637 |
dprintk("%s: write %Zd bytes ", bd->name, count); |
3d6392cfb
|
638 639 |
bsg_set_block(bd, file); |
3d6392cfb
|
640 |
|
25fd16430
|
641 |
bytes_written = 0; |
abf543937
|
642 643 |
ret = __bsg_write(bd, buf, count, &bytes_written, file->f_mode & FMODE_WRITE); |
25fd16430
|
644 |
*ppos = bytes_written; |
3d6392cfb
|
645 646 647 648 |
/* * return bytes written on non-fatal errors */ |
25fd16430
|
649 650 |
if (!bytes_written || (bytes_written && err_block_err(ret))) bytes_written = ret; |
3d6392cfb
|
651 |
|
25fd16430
|
652 653 654 |
dprintk("%s: returning %Zd ", bd->name, bytes_written); return bytes_written; |
3d6392cfb
|
655 |
} |
3d6392cfb
|
656 657 |
static struct bsg_device *bsg_alloc_device(void) { |
3d6392cfb
|
658 |
struct bsg_device *bd; |
3d6392cfb
|
659 660 661 662 663 664 |
bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL); if (unlikely(!bd)) return NULL; spin_lock_init(&bd->lock); |
5309cb38d
|
665 |
bd->max_queue = BSG_DEFAULT_CMDS; |
3d6392cfb
|
666 667 668 669 670 671 672 673 |
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; |
3d6392cfb
|
674 |
} |
97f46ae45
|
675 676 677 678 |
static void bsg_kref_release_function(struct kref *kref) { struct bsg_class_device *bcd = container_of(kref, struct bsg_class_device, ref); |
8df5fc042
|
679 |
struct device *parent = bcd->parent; |
97f46ae45
|
680 681 682 |
if (bcd->release) bcd->release(bcd->parent); |
8df5fc042
|
683 |
put_device(parent); |
97f46ae45
|
684 |
} |
3d6392cfb
|
685 686 |
static int bsg_put_device(struct bsg_device *bd) { |
97f46ae45
|
687 688 |
int ret = 0, do_free; struct request_queue *q = bd->queue; |
3d6392cfb
|
689 690 |
mutex_lock(&bsg_mutex); |
97f46ae45
|
691 |
do_free = atomic_dec_and_test(&bd->ref_count); |
3f27e3ed1
|
692 693 |
if (!do_free) { mutex_unlock(&bsg_mutex); |
3d6392cfb
|
694 |
goto out; |
3f27e3ed1
|
695 696 697 698 |
} hlist_del(&bd->dev_list); mutex_unlock(&bsg_mutex); |
3d6392cfb
|
699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 |
dprintk("%s: tearing down ", 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); |
5309cb38d
|
714 |
kfree(bd); |
3d6392cfb
|
715 |
out: |
97f46ae45
|
716 717 718 |
kref_put(&q->bsg_dev.ref, bsg_kref_release_function); if (do_free) blk_put_queue(q); |
3d6392cfb
|
719 720 721 722 |
return ret; } static struct bsg_device *bsg_add_device(struct inode *inode, |
d351af01b
|
723 |
struct request_queue *rq, |
3d6392cfb
|
724 725 |
struct file *file) { |
25fd16430
|
726 |
struct bsg_device *bd; |
c3ff1b90d
|
727 |
int ret; |
3d6392cfb
|
728 729 730 |
#ifdef BSG_DEBUG unsigned char buf[32]; #endif |
c3ff1b90d
|
731 732 733 |
ret = blk_get_queue(rq); if (ret) return ERR_PTR(-ENXIO); |
3d6392cfb
|
734 735 |
bd = bsg_alloc_device(); |
c3ff1b90d
|
736 737 |
if (!bd) { blk_put_queue(rq); |
3d6392cfb
|
738 |
return ERR_PTR(-ENOMEM); |
c3ff1b90d
|
739 |
} |
3d6392cfb
|
740 |
|
d351af01b
|
741 |
bd->queue = rq; |
0b07de85a
|
742 |
|
3d6392cfb
|
743 744 745 |
bsg_set_block(bd, file); atomic_set(&bd->ref_count, 1); |
3d6392cfb
|
746 |
mutex_lock(&bsg_mutex); |
842ea771c
|
747 |
hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode))); |
3d6392cfb
|
748 |
|
3ada8b7e9
|
749 |
strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1); |
3d6392cfb
|
750 751 |
dprintk("bound to <%s>, max queue %d ", |
9e69fbb53
|
752 |
format_dev_t(buf, inode->i_rdev), bd->max_queue); |
3d6392cfb
|
753 754 755 756 |
mutex_unlock(&bsg_mutex); return bd; } |
842ea771c
|
757 |
static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q) |
3d6392cfb
|
758 |
{ |
43ac9e62c
|
759 |
struct bsg_device *bd; |
3d6392cfb
|
760 761 762 |
struct hlist_node *entry; mutex_lock(&bsg_mutex); |
43ac9e62c
|
763 |
hlist_for_each_entry(bd, entry, bsg_dev_idx_hash(minor), dev_list) { |
842ea771c
|
764 |
if (bd->queue == q) { |
3d6392cfb
|
765 |
atomic_inc(&bd->ref_count); |
43ac9e62c
|
766 |
goto found; |
3d6392cfb
|
767 |
} |
3d6392cfb
|
768 |
} |
43ac9e62c
|
769 770 |
bd = NULL; found: |
3d6392cfb
|
771 772 773 774 775 776 |
mutex_unlock(&bsg_mutex); return bd; } static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file) { |
598443a21
|
777 778 |
struct bsg_device *bd; struct bsg_class_device *bcd; |
3d6392cfb
|
779 |
|
3d6392cfb
|
780 781 782 |
/* * find the class device */ |
3d6392cfb
|
783 |
mutex_lock(&bsg_mutex); |
598443a21
|
784 |
bcd = idr_find(&bsg_minor_idr, iminor(inode)); |
d45ac4fa8
|
785 |
if (bcd) |
97f46ae45
|
786 |
kref_get(&bcd->ref); |
3d6392cfb
|
787 788 789 790 |
mutex_unlock(&bsg_mutex); if (!bcd) return ERR_PTR(-ENODEV); |
842ea771c
|
791 |
bd = __bsg_get_device(iminor(inode), bcd->queue); |
d45ac4fa8
|
792 793 794 795 796 |
if (bd) return bd; bd = bsg_add_device(inode, bcd->queue, file); if (IS_ERR(bd)) |
97f46ae45
|
797 |
kref_put(&bcd->ref, bsg_kref_release_function); |
d45ac4fa8
|
798 799 |
return bd; |
3d6392cfb
|
800 801 802 803 |
} static int bsg_open(struct inode *inode, struct file *file) { |
75bd2ef14
|
804 805 806 807 808 |
struct bsg_device *bd; lock_kernel(); bd = bsg_get_device(inode, file); unlock_kernel(); |
3d6392cfb
|
809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 |
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; } |
25fd16430
|
842 |
static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
3d6392cfb
|
843 844 845 |
{ struct bsg_device *bd = file->private_data; int __user *uarg = (int __user *) arg; |
2d507a01d
|
846 |
int ret; |
3d6392cfb
|
847 |
|
3d6392cfb
|
848 849 850 851 852 853 |
switch (cmd) { /* * our own ioctls */ case SG_GET_COMMAND_Q: return put_user(bd->max_queue, uarg); |
5309cb38d
|
854 |
case SG_SET_COMMAND_Q: { |
3d6392cfb
|
855 856 857 858 |
int queue; if (get_user(queue, uarg)) return -EFAULT; |
5309cb38d
|
859 |
if (queue < 1) |
3d6392cfb
|
860 |
return -EINVAL; |
5309cb38d
|
861 |
spin_lock_irq(&bd->lock); |
3d6392cfb
|
862 |
bd->max_queue = queue; |
5309cb38d
|
863 |
spin_unlock_irq(&bd->lock); |
3d6392cfb
|
864 865 866 867 868 869 870 871 872 873 874 875 876 877 |
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: |
3d6392cfb
|
878 879 |
case SCSI_IOCTL_SEND_COMMAND: { void __user *uarg = (void __user *) arg; |
74f3c8aff
|
880 |
return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg); |
3d6392cfb
|
881 |
} |
10e8855b9
|
882 883 |
case SG_IO: { struct request *rq; |
2c9ecdf40
|
884 |
struct bio *bio, *bidi_bio = NULL; |
10e8855b9
|
885 |
struct sg_io_v4 hdr; |
05378940c
|
886 |
int at_head; |
c1c201200
|
887 |
u8 sense[SCSI_SENSE_BUFFERSIZE]; |
10e8855b9
|
888 889 890 |
if (copy_from_user(&hdr, uarg, sizeof(hdr))) return -EFAULT; |
c1c201200
|
891 |
rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE, sense); |
10e8855b9
|
892 893 894 895 |
if (IS_ERR(rq)) return PTR_ERR(rq); bio = rq->bio; |
2c9ecdf40
|
896 897 |
if (rq->next_rq) bidi_bio = rq->next_rq->bio; |
05378940c
|
898 899 900 |
at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL)); blk_execute_rq(bd->queue, NULL, rq, at_head); |
2d507a01d
|
901 |
ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio); |
10e8855b9
|
902 903 904 |
if (copy_to_user(uarg, &hdr, sizeof(hdr))) return -EFAULT; |
b711afa69
|
905 |
|
2d507a01d
|
906 |
return ret; |
10e8855b9
|
907 |
} |
3d6392cfb
|
908 909 910 911 912 913 914 915 916 917 918 |
/* * block device ioctls */ default: #if 0 return ioctl_by_bdev(bd->bdev, cmd, arg); #else return -ENOTTY; #endif } } |
7344be053
|
919 |
static const struct file_operations bsg_fops = { |
3d6392cfb
|
920 921 922 923 924 |
.read = bsg_read, .write = bsg_write, .poll = bsg_poll, .open = bsg_open, .release = bsg_release, |
25fd16430
|
925 |
.unlocked_ioctl = bsg_ioctl, |
3d6392cfb
|
926 927 |
.owner = THIS_MODULE, }; |
d351af01b
|
928 |
void bsg_unregister_queue(struct request_queue *q) |
3d6392cfb
|
929 |
{ |
d351af01b
|
930 |
struct bsg_class_device *bcd = &q->bsg_dev; |
3d6392cfb
|
931 |
|
df468820b
|
932 933 |
if (!bcd->class_dev) return; |
3d6392cfb
|
934 935 |
mutex_lock(&bsg_mutex); |
598443a21
|
936 |
idr_remove(&bsg_minor_idr, bcd->minor); |
d351af01b
|
937 |
sysfs_remove_link(&q->kobj, "bsg"); |
ee959b00c
|
938 |
device_unregister(bcd->class_dev); |
3d6392cfb
|
939 |
bcd->class_dev = NULL; |
97f46ae45
|
940 |
kref_put(&bcd->ref, bsg_kref_release_function); |
3d6392cfb
|
941 942 |
mutex_unlock(&bsg_mutex); } |
4cf0723ac
|
943 |
EXPORT_SYMBOL_GPL(bsg_unregister_queue); |
3d6392cfb
|
944 |
|
97f46ae45
|
945 946 |
int bsg_register_queue(struct request_queue *q, struct device *parent, const char *name, void (*release)(struct device *)) |
3d6392cfb
|
947 |
{ |
598443a21
|
948 |
struct bsg_class_device *bcd; |
3d6392cfb
|
949 |
dev_t dev; |
598443a21
|
950 |
int ret, minor; |
ee959b00c
|
951 |
struct device *class_dev = NULL; |
39dca558a
|
952 953 954 955 956 |
const char *devname; if (name) devname = name; else |
3ada8b7e9
|
957 |
devname = dev_name(parent); |
3d6392cfb
|
958 959 960 961 962 963 |
/* * we need a proper transport to send commands, not a stacked device */ if (!q->request_fn) return 0; |
d351af01b
|
964 |
bcd = &q->bsg_dev; |
3d6392cfb
|
965 |
memset(bcd, 0, sizeof(*bcd)); |
3d6392cfb
|
966 967 |
mutex_lock(&bsg_mutex); |
292b7f271
|
968 |
|
598443a21
|
969 970 971 972 |
ret = idr_pre_get(&bsg_minor_idr, GFP_KERNEL); if (!ret) { ret = -ENOMEM; goto unlock; |
292b7f271
|
973 |
} |
598443a21
|
974 975 976 |
ret = idr_get_new(&bsg_minor_idr, bcd, &minor); if (ret < 0) goto unlock; |
292b7f271
|
977 |
|
598443a21
|
978 979 980 981 982 983 984 985 |
if (minor >= BSG_MAX_DEVS) { printk(KERN_ERR "bsg: too many bsg devices "); ret = -EINVAL; goto remove_idr; } bcd->minor = minor; |
d351af01b
|
986 |
bcd->queue = q; |
97f46ae45
|
987 988 989 |
bcd->parent = get_device(parent); bcd->release = release; kref_init(&bcd->ref); |
46f6ef4af
|
990 |
dev = MKDEV(bsg_major, bcd->minor); |
1ff9f542e
|
991 |
class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname); |
4e2872d6b
|
992 993 |
if (IS_ERR(class_dev)) { ret = PTR_ERR(class_dev); |
598443a21
|
994 |
goto put_dev; |
4e2872d6b
|
995 996 |
} bcd->class_dev = class_dev; |
abce891a1
|
997 |
if (q->kobj.sd) { |
4e2872d6b
|
998 999 |
ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg"); if (ret) |
598443a21
|
1000 |
goto unregister_class_dev; |
4e2872d6b
|
1001 |
} |
3d6392cfb
|
1002 1003 |
mutex_unlock(&bsg_mutex); return 0; |
6826ee4fd
|
1004 |
|
598443a21
|
1005 |
unregister_class_dev: |
ee959b00c
|
1006 |
device_unregister(class_dev); |
598443a21
|
1007 |
put_dev: |
97f46ae45
|
1008 |
put_device(parent); |
598443a21
|
1009 1010 1011 |
remove_idr: idr_remove(&bsg_minor_idr, minor); unlock: |
264a04721
|
1012 |
mutex_unlock(&bsg_mutex); |
4e2872d6b
|
1013 1014 |
return ret; } |
4cf0723ac
|
1015 |
EXPORT_SYMBOL_GPL(bsg_register_queue); |
4e2872d6b
|
1016 |
|
7e7654a92
|
1017 |
static struct cdev bsg_cdev; |
292b7f271
|
1018 |
|
e454cea20
|
1019 |
static char *bsg_devnode(struct device *dev, mode_t *mode) |
2bdf91491
|
1020 1021 1022 |
{ return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev)); } |
3d6392cfb
|
1023 1024 1025 |
static int __init bsg_init(void) { int ret, i; |
46f6ef4af
|
1026 |
dev_t devid; |
3d6392cfb
|
1027 |
|
5309cb38d
|
1028 |
bsg_cmd_cachep = kmem_cache_create("bsg_cmd", |
20c2df83d
|
1029 |
sizeof(struct bsg_command), 0, 0, NULL); |
5309cb38d
|
1030 1031 1032 1033 1034 |
if (!bsg_cmd_cachep) { printk(KERN_ERR "bsg: failed creating slab cache "); return -ENOMEM; } |
25fd16430
|
1035 |
for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++) |
3d6392cfb
|
1036 1037 1038 |
INIT_HLIST_HEAD(&bsg_device_list[i]); bsg_class = class_create(THIS_MODULE, "bsg"); |
5309cb38d
|
1039 |
if (IS_ERR(bsg_class)) { |
9b9f770ce
|
1040 1041 |
ret = PTR_ERR(bsg_class); goto destroy_kmemcache; |
5309cb38d
|
1042 |
} |
e454cea20
|
1043 |
bsg_class->devnode = bsg_devnode; |
3d6392cfb
|
1044 |
|
46f6ef4af
|
1045 |
ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg"); |
9b9f770ce
|
1046 1047 |
if (ret) goto destroy_bsg_class; |
292b7f271
|
1048 |
|
46f6ef4af
|
1049 |
bsg_major = MAJOR(devid); |
292b7f271
|
1050 |
cdev_init(&bsg_cdev, &bsg_fops); |
46f6ef4af
|
1051 |
ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS); |
9b9f770ce
|
1052 1053 |
if (ret) goto unregister_chrdev; |
3d6392cfb
|
1054 |
|
5d3a8cd34
|
1055 |
printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION |
0ed081ce2
|
1056 1057 |
" loaded (major %d) ", bsg_major); |
3d6392cfb
|
1058 |
return 0; |
9b9f770ce
|
1059 1060 1061 1062 1063 1064 1065 |
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; |
3d6392cfb
|
1066 1067 1068 |
} MODULE_AUTHOR("Jens Axboe"); |
0ed081ce2
|
1069 |
MODULE_DESCRIPTION(BSG_DESCRIPTION); |
3d6392cfb
|
1070 |
MODULE_LICENSE("GPL"); |
4e2872d6b
|
1071 |
device_initcall(bsg_init); |