diff options
Diffstat (limited to 'block/bsg.c')
| -rw-r--r-- | block/bsg.c | 1124 |
1 files changed, 142 insertions, 982 deletions
diff --git a/block/bsg.c b/block/bsg.c index 420a5a9f1b23..72157a59b788 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -1,32 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0 /* * 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" @@ -34,1079 +22,251 @@ 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]; + struct device device; + struct cdev cdev; int max_queue; - unsigned long flags; + unsigned int timeout; + unsigned int reserved_size; + bsg_sg_io_fn *sg_io_fn; }; -enum { - BSG_F_BLOCK = 1, -}; - -#define BSG_DEFAULT_CMDS 64 -#define BSG_MAX_DEVS 32768 - -#undef BSG_DEBUG - -#ifdef BSG_DEBUG -#define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ##args) -#else -#define dprintk(fmt, args...) -#endif - -static DEFINE_MUTEX(bsg_mutex); -static DEFINE_IDR(bsg_minor_idr); - -#define BSG_LIST_ARRAY_SIZE 8 -static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE]; - -static struct class *bsg_class; -static int bsg_major; - -static struct kmem_cache *bsg_cmd_cachep; - -/* - * our internal command type - */ -struct bsg_command { - struct bsg_device *bd; - struct list_head list; - struct request *rq; - struct bio *bio; - struct bio *bidi_bio; - int err; - struct sg_io_v4 hdr; - char sense[SCSI_SENSE_BUFFERSIZE]; -}; - -static void bsg_free_command(struct bsg_command *bc) -{ - struct bsg_device *bd = bc->bd; - unsigned long flags; - - kmem_cache_free(bsg_cmd_cachep, bc); - - spin_lock_irqsave(&bd->lock, flags); - bd->queued_cmds--; - spin_unlock_irqrestore(&bd->lock, flags); - - wake_up(&bd->wq_free); -} - -static struct bsg_command *bsg_alloc_command(struct bsg_device *bd) -{ - struct bsg_command *bc = ERR_PTR(-EINVAL); - - spin_lock_irq(&bd->lock); - - if (bd->queued_cmds >= bd->max_queue) - goto out; - - bd->queued_cmds++; - spin_unlock_irq(&bd->lock); - - bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL); - if (unlikely(!bc)) { - spin_lock_irq(&bd->lock); - bd->queued_cmds--; - bc = ERR_PTR(-ENOMEM); - goto out; - } - - bc->bd = bd; - INIT_LIST_HEAD(&bc->list); - dprintk("%s: returning free cmd %p\n", bd->name, bc); - return bc; -out: - spin_unlock_irq(&bd->lock); - return bc; -} - -static inline struct hlist_head *bsg_dev_idx_hash(int index) -{ - return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)]; -} - -static int bsg_io_schedule(struct bsg_device *bd) -{ - DEFINE_WAIT(wait); - int ret = 0; - - spin_lock_irq(&bd->lock); - - BUG_ON(bd->done_cmds > bd->queued_cmds); - - /* - * -ENOSPC or -ENODATA? I'm going for -ENODATA, meaning "I have no - * work to do", even though we return -ENOSPC after this same test - * during bsg_write() -- there, it means our buffer can't have more - * bsg_commands added to it, thus has no space left. - */ - if (bd->done_cmds == bd->queued_cmds) { - ret = -ENODATA; - goto unlock; - } - - if (!test_bit(BSG_F_BLOCK, &bd->flags)) { - ret = -EAGAIN; - goto unlock; - } - - prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE); - spin_unlock_irq(&bd->lock); - io_schedule(); - finish_wait(&bd->wq_done, &wait); - - return ret; -unlock: - spin_unlock_irq(&bd->lock); - return ret; -} - -static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq, - struct sg_io_v4 *hdr, struct bsg_device *bd, - fmode_t has_write_perm) -{ - if (hdr->request_len > BLK_MAX_CDB) { - rq->cmd = kzalloc(hdr->request_len, GFP_KERNEL); - if (!rq->cmd) - return -ENOMEM; - } - - if (copy_from_user(rq->cmd, (void __user *)(unsigned long)hdr->request, - hdr->request_len)) - return -EFAULT; - - if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) { - if (blk_verify_command(rq->cmd, has_write_perm)) - return -EPERM; - } else if (!capable(CAP_SYS_RAWIO)) - return -EPERM; - - /* - * fill in request structure - */ - rq->cmd_len = hdr->request_len; - rq->cmd_type = REQ_TYPE_BLOCK_PC; - - rq->timeout = msecs_to_jiffies(hdr->timeout); - if (!rq->timeout) - rq->timeout = q->sg_timeout; - if (!rq->timeout) - rq->timeout = BLK_DEFAULT_SG_TIMEOUT; - if (rq->timeout < BLK_MIN_SG_TIMEOUT) - rq->timeout = BLK_MIN_SG_TIMEOUT; - - return 0; -} - -/* - * Check if sg_io_v4 from user is allowed and valid - */ -static int -bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw) -{ - int ret = 0; - - if (hdr->guard != 'Q') - return -EINVAL; - - switch (hdr->protocol) { - case BSG_PROTOCOL_SCSI: - switch (hdr->subprotocol) { - case BSG_SUB_PROTOCOL_SCSI_CMD: - case BSG_SUB_PROTOCOL_SCSI_TRANSPORT: - break; - default: - ret = -EINVAL; - } - break; - default: - ret = -EINVAL; - } - - *rw = hdr->dout_xfer_len ? WRITE : READ; - return ret; -} - -/* - * map sg_io_v4 to a request. - */ -static struct request * -bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm, - u8 *sense) -{ - struct request_queue *q = bd->queue; - struct request *rq, *next_rq = NULL; - int ret, rw; - unsigned int dxfer_len; - void __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(q, hdr, &rw); - if (ret) - return ERR_PTR(ret); - - /* - * map scatter-gather elements separately and string them to request - */ - rq = blk_get_request(q, rw, GFP_KERNEL); - if (!rq) - return ERR_PTR(-ENOMEM); - ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm); - if (ret) - goto out; - - if (rw == WRITE && hdr->din_xfer_len) { - if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) { - ret = -EOPNOTSUPP; - goto out; - } - - next_rq = blk_get_request(q, READ, GFP_KERNEL); - if (!next_rq) { - ret = -ENOMEM; - goto out; - } - rq->next_rq = next_rq; - next_rq->cmd_type = rq->cmd_type; - - dxferp = (void __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; - } - - rq->sense = sense; - rq->sense_len = 0; - - return rq; -out: - if (rq->cmd != rq->__cmd) - kfree(rq->cmd); - blk_put_request(rq); - if (next_rq) { - blk_rq_unmap_user(next_rq->bio); - blk_put_request(next_rq); - } - return ERR_PTR(ret); -} - -/* - * async completion call-back from the block layer, when scsi/ide/whatever - * calls end_that_request_last() on a request - */ -static void bsg_rq_end_io(struct request *rq, int uptodate) +static inline struct bsg_device *to_bsg_device(struct inode *inode) { - 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); + return container_of(inode->i_cdev, struct bsg_device, cdev); } -/* - * 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); +#define BSG_DEFAULT_CMDS 64 +#define BSG_MAX_DEVS (1 << MINORBITS) - rq->end_io_data = bc; - blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io); -} +static DEFINE_IDA(bsg_minor_ida); +static const struct class bsg_class; +static int bsg_major; -static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd) +static unsigned int bsg_timeout(struct bsg_device *bd, struct sg_io_v4 *hdr) { - struct bsg_command *bc = NULL; + unsigned int timeout = BLK_DEFAULT_SG_TIMEOUT; - 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); + if (hdr->timeout) + timeout = msecs_to_jiffies(hdr->timeout); + else if (bd->timeout) + timeout = bd->timeout; - return bc; + return max_t(unsigned int, timeout, BLK_MIN_SG_TIMEOUT); } -/* - * Get a finished command from the done list - */ -static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd) +static int bsg_sg_io(struct bsg_device *bd, bool open_for_write, + void __user *uarg) { - struct bsg_command *bc; + struct sg_io_v4 hdr; int ret; - do { - bc = bsg_next_done_cmd(bd); - if (bc) - break; - - if (!test_bit(BSG_F_BLOCK, &bd->flags)) { - bc = ERR_PTR(-EAGAIN); - break; - } - - ret = wait_event_interruptible(bd->wq_done, bd->done_cmds); - if (ret) { - bc = ERR_PTR(-ERESTARTSYS); - break; - } - } while (1); - - dprintk("%s: returning done %p\n", bd->name, bc); - - return bc; -} - -static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr, - struct bio *bio, struct bio *bidi_bio) -{ - int ret = 0; - - dprintk("rq %p bio %p 0x%x\n", rq, bio, rq->errors); - /* - * fill in all the output members - */ - hdr->device_status = rq->errors & 0xff; - hdr->transport_status = host_byte(rq->errors); - hdr->driver_status = driver_byte(rq->errors); - hdr->info = 0; - if (hdr->device_status || hdr->transport_status || hdr->driver_status) - hdr->info |= SG_INFO_CHECK; - hdr->response_len = 0; - - if (rq->sense_len && hdr->response) { - int len = min_t(unsigned int, hdr->max_response_len, - rq->sense_len); - - ret = copy_to_user((void __user *)(unsigned long)hdr->response, - rq->sense, len); - if (!ret) - hdr->response_len = len; - else - ret = -EFAULT; - } - - if (rq->next_rq) { - hdr->dout_resid = rq->resid_len; - hdr->din_resid = rq->next_rq->resid_len; - blk_rq_unmap_user(bidi_bio); - blk_put_request(rq->next_rq); - } else if (rq_data_dir(rq) == READ) - hdr->din_resid = rq->resid_len; - else - hdr->dout_resid = rq->resid_len; - - /* - * If the request generated a negative error number, return it - * (providing we aren't already returning an error); if it's - * just a protocol response (i.e. non negative), that gets - * processed above. - */ - if (!ret && rq->errors < 0) - ret = rq->errors; - - blk_rq_unmap_user(bio); - if (rq->cmd != rq->__cmd) - kfree(rq->cmd); - blk_put_request(rq); - - return ret; -} - -static int bsg_complete_all_commands(struct bsg_device *bd) -{ - struct bsg_command *bc; - int ret, tret; - - dprintk("%s: entered\n", bd->name); - - /* - * wait for all commands to complete - */ - ret = 0; - do { - ret = bsg_io_schedule(bd); - /* - * look for -ENODATA specifically -- we'll sometimes get - * -ERESTARTSYS when we've taken a signal, but we can't - * return until we're done freeing the queue, so ignore - * it. The signal will get handled when we're done freeing - * the bsg_device. - */ - } while (ret != -ENODATA); - - /* - * discard done commands - */ - ret = 0; - do { - spin_lock_irq(&bd->lock); - if (!bd->queued_cmds) { - spin_unlock_irq(&bd->lock); - break; - } - spin_unlock_irq(&bd->lock); - - bc = bsg_get_done_cmd(bd); - if (IS_ERR(bc)) - break; - - tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio, - bc->bidi_bio); - if (!ret) - ret = tret; - - bsg_free_command(bc); - } while (1); - - return ret; -} - -static int -__bsg_read(char __user *buf, size_t count, struct bsg_device *bd, - const struct iovec *iov, ssize_t *bytes_read) -{ - struct bsg_command *bc; - int nr_commands, ret; - - if (count % sizeof(struct sg_io_v4)) + if (copy_from_user(&hdr, uarg, sizeof(hdr))) + return -EFAULT; + if (hdr.guard != 'Q') 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--; - } - + ret = bd->sg_io_fn(bd->queue, &hdr, open_for_write, + bsg_timeout(bd, &hdr)); + if (!ret && copy_to_user(uarg, &hdr, sizeof(hdr))) + return -EFAULT; return ret; } -static inline void bsg_set_block(struct bsg_device *bd, struct file *file) +static int bsg_open(struct inode *inode, struct file *file) { - if (file->f_flags & O_NONBLOCK) - clear_bit(BSG_F_BLOCK, &bd->flags); - else - set_bit(BSG_F_BLOCK, &bd->flags); + if (!blk_get_queue(to_bsg_device(inode)->queue)) + return -ENXIO; + return 0; } -/* - * Check if the error is a "real" error that we should return. - */ -static inline int err_block_err(int ret) +static int bsg_release(struct inode *inode, struct file *file) { - if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN) - return 1; - + blk_put_queue(to_bsg_device(inode)->queue); return 0; } -static ssize_t -bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) +static int bsg_get_command_q(struct bsg_device *bd, int __user *uarg) { - 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; + return put_user(READ_ONCE(bd->max_queue), uarg); } -static int __bsg_write(struct bsg_device *bd, const char __user *buf, - size_t count, ssize_t *bytes_written, - fmode_t has_write_perm) +static int bsg_set_command_q(struct bsg_device *bd, int __user *uarg) { - struct bsg_command *bc; - struct request *rq; - int ret, nr_commands; + int max_queue; - if (count % sizeof(struct sg_io_v4)) + if (get_user(max_queue, uarg)) + return -EFAULT; + if (max_queue < 1) return -EINVAL; - - nr_commands = count / sizeof(struct sg_io_v4); - rq = NULL; - bc = NULL; - ret = 0; - while (nr_commands) { - struct request_queue *q = bd->queue; - - bc = bsg_alloc_command(bd); - if (IS_ERR(bc)) { - ret = PTR_ERR(bc); - bc = NULL; - break; - } - - if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) { - ret = -EFAULT; - break; - } - - /* - * get a request, fill in the blanks, and add to request queue - */ - rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm, bc->sense); - if (IS_ERR(rq)) { - ret = PTR_ERR(rq); - rq = NULL; - break; - } - - bsg_add_command(bd, q, bc, rq); - bc = NULL; - rq = NULL; - nr_commands--; - buf += sizeof(struct sg_io_v4); - *bytes_written += sizeof(struct sg_io_v4); - } - - if (bc) - bsg_free_command(bc); - - return ret; -} - -static ssize_t -bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) -{ - struct bsg_device *bd = file->private_data; - ssize_t bytes_written; - int ret; - - dprintk("%s: write %Zd bytes\n", bd->name, count); - - bsg_set_block(bd, file); - - bytes_written = 0; - ret = __bsg_write(bd, buf, count, &bytes_written, - file->f_mode & FMODE_WRITE); - - *ppos = bytes_written; - - /* - * return bytes written on non-fatal errors - */ - if (!bytes_written || 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; + WRITE_ONCE(bd->max_queue, max_queue); 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; + struct bsg_device *bd = to_bsg_device(file_inode(file)); + struct request_queue *q = bd->queue; + void __user *uarg = (void __user *) arg; + int __user *intp = uarg; + int val; switch (cmd) { - /* - * our own ioctls - */ + /* + * 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; - } + return bsg_get_command_q(bd, uarg); + case SG_SET_COMMAND_Q: + return bsg_set_command_q(bd, uarg); /* * SCSI/sg ioctls */ case SG_GET_VERSION_NUM: + return put_user(30527, intp); case SCSI_IOCTL_GET_IDLUN: + return put_user(0, intp); case SCSI_IOCTL_GET_BUS_NUMBER: + return put_user(0, intp); case SG_SET_TIMEOUT: + if (get_user(val, intp)) + return -EFAULT; + bd->timeout = clock_t_to_jiffies(val); + return 0; case SG_GET_TIMEOUT: + return jiffies_to_clock_t(bd->timeout); case SG_GET_RESERVED_SIZE: + return put_user(min(bd->reserved_size, queue_max_bytes(q)), + intp); case SG_SET_RESERVED_SIZE: - case SG_EMULATED_HOST: - case SCSI_IOCTL_SEND_COMMAND: { - void __user *uarg = (void __user *) arg; - return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg); - } - case SG_IO: { - struct request *rq; - struct bio *bio, *bidi_bio = NULL; - struct sg_io_v4 hdr; - int at_head; - u8 sense[SCSI_SENSE_BUFFERSIZE]; - - if (copy_from_user(&hdr, uarg, sizeof(hdr))) - return -EFAULT; - - rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE, sense); - if (IS_ERR(rq)) - return PTR_ERR(rq); - - bio = rq->bio; - if (rq->next_rq) - bidi_bio = rq->next_rq->bio; - - at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL)); - blk_execute_rq(bd->queue, NULL, rq, at_head); - ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio); - - if (copy_to_user(uarg, &hdr, sizeof(hdr))) + if (get_user(val, intp)) return -EFAULT; - - return ret; - } - /* - * block device ioctls - */ + if (val < 0) + return -EINVAL; + bd->reserved_size = + min_t(unsigned int, val, queue_max_bytes(q)); + return 0; + case SG_EMULATED_HOST: + return put_user(1, intp); + case SG_IO: + return bsg_sg_io(bd, file->f_mode & FMODE_WRITE, uarg); + case SCSI_IOCTL_SEND_COMMAND: + pr_warn_ratelimited("%s: calling unsupported SCSI_IOCTL_SEND_COMMAND\n", + current->comm); + return -EINVAL; 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, + .compat_ioctl = compat_ptr_ioctl, .owner = THIS_MODULE, .llseek = default_llseek, }; -void bsg_unregister_queue(struct request_queue *q) +static void bsg_device_release(struct device *dev) { - struct bsg_class_device *bcd = &q->bsg_dev; + struct bsg_device *bd = container_of(dev, struct bsg_device, device); - if (!bcd->class_dev) - return; + ida_free(&bsg_minor_ida, MINOR(bd->device.devt)); + kfree(bd); +} - 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); +void bsg_unregister_queue(struct bsg_device *bd) +{ + struct gendisk *disk = bd->queue->disk; + + if (disk && disk->queue_kobj.sd) + sysfs_remove_link(&disk->queue_kobj, "bsg"); + cdev_device_del(&bd->cdev, &bd->device); + put_device(&bd->device); } 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_device *bsg_register_queue(struct request_queue *q, + struct device *parent, const char *name, bsg_sg_io_fn *sg_io_fn) { - struct bsg_class_device *bcd; - dev_t dev; + struct bsg_device *bd; 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 (!q->request_fn) - return 0; - - bcd = &q->bsg_dev; - memset(bcd, 0, sizeof(*bcd)); - - mutex_lock(&bsg_mutex); + bd = kzalloc(sizeof(*bd), GFP_KERNEL); + if (!bd) + return ERR_PTR(-ENOMEM); + bd->max_queue = BSG_DEFAULT_CMDS; + bd->reserved_size = INT_MAX; + bd->queue = q; + bd->sg_io_fn = sg_io_fn; - ret = idr_alloc(&bsg_minor_idr, bcd, 0, BSG_MAX_DEVS, GFP_KERNEL); + ret = ida_alloc_max(&bsg_minor_ida, BSG_MAX_DEVS - 1, 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; + if (ret == -ENOSPC) + dev_err(parent, "bsg: too many bsg devices\n"); + kfree(bd); + return ERR_PTR(ret); } - bcd->class_dev = class_dev; + bd->device.devt = MKDEV(bsg_major, ret); + bd->device.class = &bsg_class; + bd->device.parent = parent; + bd->device.release = bsg_device_release; + dev_set_name(&bd->device, "%s", name); + device_initialize(&bd->device); + + cdev_init(&bd->cdev, &bsg_fops); + bd->cdev.owner = THIS_MODULE; + ret = cdev_device_add(&bd->cdev, &bd->device); + if (ret) + goto out_put_device; - if (q->kobj.sd) { - ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg"); + if (q->disk && q->disk->queue_kobj.sd) { + ret = sysfs_create_link(&q->disk->queue_kobj, &bd->device.kobj, + "bsg"); if (ret) - goto unregister_class_dev; + goto out_device_del; } - mutex_unlock(&bsg_mutex); - return 0; + return bd; -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; +out_device_del: + cdev_device_del(&bd->cdev, &bd->device); +out_put_device: + put_device(&bd->device); + return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(bsg_register_queue); -static struct cdev bsg_cdev; - -static char *bsg_devnode(struct device *dev, umode_t *mode) +static char *bsg_devnode(const struct device *dev, umode_t *mode) { return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev)); } +static const struct class bsg_class = { + .name = "bsg", + .devnode = bsg_devnode, +}; + static int __init bsg_init(void) { - int ret, i; dev_t devid; + int ret; - 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 = class_register(&bsg_class); + if (ret) + return ret; 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); + class_unregister(&bsg_class); return ret; } |