mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-29 23:53:32 +00:00
20c2df83d2
Slab destructors were no longer supported after Christoph's
c59def9f22
change. They've been
BUGs for both slab and slub, and slob never supported them
either.
This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
1095 lines
23 KiB
C
1095 lines
23 KiB
C
/*
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* bsg.c - block layer implementation of the sg v3 interface
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*
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* Copyright (C) 2004 Jens Axboe <axboe@suse.de> SUSE Labs
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* Copyright (C) 2004 Peter M. Jones <pjones@redhat.com>
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License version 2. See the file "COPYING" in the main directory of this
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* archive for more details.
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*
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*/
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/*
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* TODO
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* - Should this get merged, block/scsi_ioctl.c will be migrated into
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* this file. To keep maintenance down, it's easier to have them
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* seperated right now.
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*
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/file.h>
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#include <linux/blkdev.h>
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#include <linux/poll.h>
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#include <linux/cdev.h>
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#include <linux/percpu.h>
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#include <linux/uio.h>
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#include <linux/bsg.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_ioctl.h>
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#include <scsi/scsi_cmnd.h>
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#include <scsi/scsi_device.h>
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#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"
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#define BSG_VERSION "0.4"
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struct bsg_device {
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request_queue_t *queue;
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spinlock_t lock;
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struct list_head busy_list;
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struct list_head done_list;
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struct hlist_node dev_list;
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atomic_t ref_count;
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int minor;
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int queued_cmds;
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int done_cmds;
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wait_queue_head_t wq_done;
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wait_queue_head_t wq_free;
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char name[BUS_ID_SIZE];
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int max_queue;
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unsigned long flags;
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};
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enum {
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BSG_F_BLOCK = 1,
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BSG_F_WRITE_PERM = 2,
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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
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#ifdef BSG_DEBUG
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#define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __FUNCTION__, ##args)
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#else
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#define dprintk(fmt, args...)
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#endif
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static DEFINE_MUTEX(bsg_mutex);
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static int bsg_device_nr, bsg_minor_idx;
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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 LIST_HEAD(bsg_class_list);
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static int bsg_major;
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static struct kmem_cache *bsg_cmd_cachep;
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/*
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* our internal command type
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*/
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struct bsg_command {
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struct bsg_device *bd;
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struct list_head list;
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struct request *rq;
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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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struct sg_io_v4 __user *uhdr;
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char sense[SCSI_SENSE_BUFFERSIZE];
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};
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static void bsg_free_command(struct bsg_command *bc)
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{
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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);
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bd->queued_cmds--;
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spin_unlock_irqrestore(&bd->lock, flags);
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wake_up(&bd->wq_free);
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}
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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);
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if (bd->queued_cmds >= bd->max_queue)
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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)) {
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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;
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INIT_LIST_HEAD(&bc->list);
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dprintk("%s: returning free cmd %p\n", bd->name, bc);
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return bc;
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out:
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spin_unlock_irq(&bd->lock);
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return bc;
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}
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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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{
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DEFINE_WAIT(wait);
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int ret = 0;
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spin_lock_irq(&bd->lock);
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BUG_ON(bd->done_cmds > bd->queued_cmds);
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/*
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* -ENOSPC or -ENODATA? I'm going for -ENODATA, meaning "I have no
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* work to do", even though we return -ENOSPC after this same test
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* during bsg_write() -- there, it means our buffer can't have more
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* bsg_commands added to it, thus has no space left.
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*/
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if (bd->done_cmds == bd->queued_cmds) {
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ret = -ENODATA;
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goto unlock;
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}
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if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
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ret = -EAGAIN;
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goto unlock;
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}
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prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE);
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spin_unlock_irq(&bd->lock);
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io_schedule();
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finish_wait(&bd->wq_done, &wait);
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return ret;
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unlock:
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spin_unlock_irq(&bd->lock);
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return ret;
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}
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static int blk_fill_sgv4_hdr_rq(request_queue_t *q, struct request *rq,
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struct sg_io_v4 *hdr, int has_write_perm)
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{
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memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
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if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request,
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hdr->request_len))
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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;
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} else if (!capable(CAP_SYS_RAWIO))
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return -EPERM;
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/*
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* fill in request structure
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*/
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rq->cmd_len = hdr->request_len;
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rq->cmd_type = REQ_TYPE_BLOCK_PC;
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rq->timeout = (hdr->timeout * HZ) / 1000;
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if (!rq->timeout)
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rq->timeout = q->sg_timeout;
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if (!rq->timeout)
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rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
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return 0;
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}
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/*
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* Check if sg_io_v4 from user is allowed and valid
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*/
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static int
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bsg_validate_sgv4_hdr(request_queue_t *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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if (hdr->request_len > BLK_MAX_CDB)
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return -EINVAL;
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if (hdr->dout_xfer_len > (q->max_sectors << 9) ||
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hdr->din_xfer_len > (q->max_sectors << 9))
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return -EIO;
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switch (hdr->protocol) {
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case BSG_PROTOCOL_SCSI:
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switch (hdr->subprotocol) {
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case BSG_SUB_PROTOCOL_SCSI_CMD:
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case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
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break;
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default:
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ret = -EINVAL;
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}
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break;
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default:
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ret = -EINVAL;
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}
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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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/*
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* map sg_io_v4 to a request.
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*/
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static struct request *
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bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)
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{
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request_queue_t *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;
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void *dxferp = NULL;
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dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp,
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hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
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hdr->din_xfer_len);
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ret = bsg_validate_sgv4_hdr(q, hdr, &rw);
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if (ret)
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return ERR_PTR(ret);
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/*
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* map scatter-gather elements seperately and string them to request
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*/
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rq = blk_get_request(q, rw, GFP_KERNEL);
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if (!rq)
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return ERR_PTR(-ENOMEM);
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ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, test_bit(BSG_F_WRITE_PERM,
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&bd->flags));
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if (ret)
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goto out;
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if (rw == WRITE && hdr->din_xfer_len) {
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if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
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ret = -EOPNOTSUPP;
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goto out;
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}
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next_rq = blk_get_request(q, READ, GFP_KERNEL);
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if (!next_rq) {
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ret = -ENOMEM;
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goto out;
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}
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rq->next_rq = next_rq;
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dxferp = (void*)(unsigned long)hdr->din_xferp;
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ret = blk_rq_map_user(q, next_rq, dxferp, hdr->din_xfer_len);
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if (ret)
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goto out;
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}
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if (hdr->dout_xfer_len) {
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dxfer_len = hdr->dout_xfer_len;
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dxferp = (void*)(unsigned long)hdr->dout_xferp;
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} else if (hdr->din_xfer_len) {
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dxfer_len = hdr->din_xfer_len;
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dxferp = (void*)(unsigned long)hdr->din_xferp;
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} else
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dxfer_len = 0;
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if (dxfer_len) {
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ret = blk_rq_map_user(q, rq, dxferp, dxfer_len);
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if (ret)
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goto out;
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}
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return rq;
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out:
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blk_put_request(rq);
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if (next_rq) {
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blk_rq_unmap_user(next_rq->bio);
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blk_put_request(next_rq);
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}
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return ERR_PTR(ret);
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}
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/*
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* async completion call-back from the block layer, when scsi/ide/whatever
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* calls end_that_request_last() on a request
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*/
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static void bsg_rq_end_io(struct request *rq, int uptodate)
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{
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struct bsg_command *bc = rq->end_io_data;
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struct bsg_device *bd = bc->bd;
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unsigned long flags;
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dprintk("%s: finished rq %p bc %p, bio %p stat %d\n",
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bd->name, rq, bc, bc->bio, uptodate);
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bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
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spin_lock_irqsave(&bd->lock, flags);
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list_move_tail(&bc->list, &bd->done_list);
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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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}
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/*
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* do final setup of a 'bc' and submit the matching 'rq' to the block
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* layer for io
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*/
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static void bsg_add_command(struct bsg_device *bd, request_queue_t *q,
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struct bsg_command *bc, struct request *rq)
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{
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rq->sense = bc->sense;
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rq->sense_len = 0;
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|
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/*
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* add bc command to busy queue and submit rq for io
|
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*/
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bc->rq = rq;
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bc->bio = rq->bio;
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if (rq->next_rq)
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bc->bidi_bio = rq->next_rq->bio;
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bc->hdr.duration = jiffies;
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spin_lock_irq(&bd->lock);
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list_add_tail(&bc->list, &bd->busy_list);
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spin_unlock_irq(&bd->lock);
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dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
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rq->end_io_data = bc;
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blk_execute_rq_nowait(q, NULL, rq, 1, 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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{
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struct bsg_command *bc = NULL;
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spin_lock_irq(&bd->lock);
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if (bd->done_cmds) {
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bc = list_entry(bd->done_list.next, struct bsg_command, list);
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list_del(&bc->list);
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bd->done_cmds--;
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}
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spin_unlock_irq(&bd->lock);
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|
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return bc;
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}
|
|
|
|
/*
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* Get a finished command from the done list
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*/
|
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static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
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{
|
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struct bsg_command *bc;
|
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int ret;
|
|
|
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do {
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bc = bsg_next_done_cmd(bd);
|
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if (bc)
|
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break;
|
|
|
|
if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
|
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bc = ERR_PTR(-EAGAIN);
|
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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;
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}
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} while (1);
|
|
|
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dprintk("%s: returning done %p\n", bd->name, bc);
|
|
|
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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)
|
|
{
|
|
int ret = 0;
|
|
|
|
dprintk("rq %p bio %p %u\n", rq, bio, rq->errors);
|
|
/*
|
|
* fill in all the output members
|
|
*/
|
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hdr->device_status = status_byte(rq->errors);
|
|
hdr->transport_status = host_byte(rq->errors);
|
|
hdr->driver_status = driver_byte(rq->errors);
|
|
hdr->info = 0;
|
|
if (hdr->device_status || hdr->transport_status || hdr->driver_status)
|
|
hdr->info |= SG_INFO_CHECK;
|
|
hdr->din_resid = rq->data_len;
|
|
hdr->response_len = 0;
|
|
|
|
if (rq->sense_len && hdr->response) {
|
|
int len = min_t(unsigned int, hdr->max_response_len,
|
|
rq->sense_len);
|
|
|
|
ret = copy_to_user((void*)(unsigned long)hdr->response,
|
|
rq->sense, len);
|
|
if (!ret)
|
|
hdr->response_len = len;
|
|
else
|
|
ret = -EFAULT;
|
|
}
|
|
|
|
if (rq->next_rq) {
|
|
blk_rq_unmap_user(bidi_bio);
|
|
blk_put_request(rq->next_rq);
|
|
}
|
|
|
|
blk_rq_unmap_user(bio);
|
|
blk_put_request(rq);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int bsg_complete_all_commands(struct bsg_device *bd)
|
|
{
|
|
struct bsg_command *bc;
|
|
int ret, tret;
|
|
|
|
dprintk("%s: entered\n", bd->name);
|
|
|
|
set_bit(BSG_F_BLOCK, &bd->flags);
|
|
|
|
/*
|
|
* wait for all commands to complete
|
|
*/
|
|
ret = 0;
|
|
do {
|
|
ret = bsg_io_schedule(bd);
|
|
/*
|
|
* look for -ENODATA specifically -- we'll sometimes get
|
|
* -ERESTARTSYS when we've taken a signal, but we can't
|
|
* return until we're done freeing the queue, so ignore
|
|
* it. The signal will get handled when we're done freeing
|
|
* the bsg_device.
|
|
*/
|
|
} while (ret != -ENODATA);
|
|
|
|
/*
|
|
* discard done commands
|
|
*/
|
|
ret = 0;
|
|
do {
|
|
spin_lock_irq(&bd->lock);
|
|
if (!bd->queued_cmds) {
|
|
spin_unlock_irq(&bd->lock);
|
|
break;
|
|
}
|
|
spin_unlock_irq(&bd->lock);
|
|
|
|
bc = bsg_get_done_cmd(bd);
|
|
if (IS_ERR(bc))
|
|
break;
|
|
|
|
tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
|
|
bc->bidi_bio);
|
|
if (!ret)
|
|
ret = tret;
|
|
|
|
bsg_free_command(bc);
|
|
} while (1);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
__bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
|
|
const struct iovec *iov, ssize_t *bytes_read)
|
|
{
|
|
struct bsg_command *bc;
|
|
int nr_commands, ret;
|
|
|
|
if (count % sizeof(struct sg_io_v4))
|
|
return -EINVAL;
|
|
|
|
ret = 0;
|
|
nr_commands = count / sizeof(struct sg_io_v4);
|
|
while (nr_commands) {
|
|
bc = bsg_get_done_cmd(bd);
|
|
if (IS_ERR(bc)) {
|
|
ret = PTR_ERR(bc);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* this is the only case where we need to copy data back
|
|
* after completing the request. so do that here,
|
|
* bsg_complete_work() cannot do that for us
|
|
*/
|
|
ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
|
|
bc->bidi_bio);
|
|
|
|
if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
|
|
ret = -EFAULT;
|
|
|
|
bsg_free_command(bc);
|
|
|
|
if (ret)
|
|
break;
|
|
|
|
buf += sizeof(struct sg_io_v4);
|
|
*bytes_read += sizeof(struct sg_io_v4);
|
|
nr_commands--;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
|
|
{
|
|
if (file->f_flags & O_NONBLOCK)
|
|
clear_bit(BSG_F_BLOCK, &bd->flags);
|
|
else
|
|
set_bit(BSG_F_BLOCK, &bd->flags);
|
|
}
|
|
|
|
static inline void bsg_set_write_perm(struct bsg_device *bd, struct file *file)
|
|
{
|
|
if (file->f_mode & FMODE_WRITE)
|
|
set_bit(BSG_F_WRITE_PERM, &bd->flags);
|
|
else
|
|
clear_bit(BSG_F_WRITE_PERM, &bd->flags);
|
|
}
|
|
|
|
/*
|
|
* Check if the error is a "real" error that we should return.
|
|
*/
|
|
static inline int err_block_err(int ret)
|
|
{
|
|
if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t
|
|
bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
|
|
{
|
|
struct bsg_device *bd = file->private_data;
|
|
int ret;
|
|
ssize_t bytes_read;
|
|
|
|
dprintk("%s: read %Zd bytes\n", bd->name, count);
|
|
|
|
bsg_set_block(bd, file);
|
|
bytes_read = 0;
|
|
ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
|
|
*ppos = bytes_read;
|
|
|
|
if (!bytes_read || (bytes_read && err_block_err(ret)))
|
|
bytes_read = ret;
|
|
|
|
return bytes_read;
|
|
}
|
|
|
|
static int __bsg_write(struct bsg_device *bd, const char __user *buf,
|
|
size_t count, ssize_t *bytes_written)
|
|
{
|
|
struct bsg_command *bc;
|
|
struct request *rq;
|
|
int ret, nr_commands;
|
|
|
|
if (count % sizeof(struct sg_io_v4))
|
|
return -EINVAL;
|
|
|
|
nr_commands = count / sizeof(struct sg_io_v4);
|
|
rq = NULL;
|
|
bc = NULL;
|
|
ret = 0;
|
|
while (nr_commands) {
|
|
request_queue_t *q = bd->queue;
|
|
|
|
bc = bsg_alloc_command(bd);
|
|
if (IS_ERR(bc)) {
|
|
ret = PTR_ERR(bc);
|
|
bc = NULL;
|
|
break;
|
|
}
|
|
|
|
bc->uhdr = (struct sg_io_v4 __user *) buf;
|
|
if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* get a request, fill in the blanks, and add to request queue
|
|
*/
|
|
rq = bsg_map_hdr(bd, &bc->hdr);
|
|
if (IS_ERR(rq)) {
|
|
ret = PTR_ERR(rq);
|
|
rq = NULL;
|
|
break;
|
|
}
|
|
|
|
bsg_add_command(bd, q, bc, rq);
|
|
bc = NULL;
|
|
rq = NULL;
|
|
nr_commands--;
|
|
buf += sizeof(struct sg_io_v4);
|
|
*bytes_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);
|
|
bsg_set_write_perm(bd, file);
|
|
|
|
bytes_written = 0;
|
|
ret = __bsg_write(bd, buf, count, &bytes_written);
|
|
*ppos = bytes_written;
|
|
|
|
/*
|
|
* return bytes written on non-fatal errors
|
|
*/
|
|
if (!bytes_written || (bytes_written && err_block_err(ret)))
|
|
bytes_written = ret;
|
|
|
|
dprintk("%s: returning %Zd\n", bd->name, bytes_written);
|
|
return bytes_written;
|
|
}
|
|
|
|
static struct bsg_device *bsg_alloc_device(void)
|
|
{
|
|
struct bsg_device *bd;
|
|
|
|
bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
|
|
if (unlikely(!bd))
|
|
return NULL;
|
|
|
|
spin_lock_init(&bd->lock);
|
|
|
|
bd->max_queue = BSG_DEFAULT_CMDS;
|
|
|
|
INIT_LIST_HEAD(&bd->busy_list);
|
|
INIT_LIST_HEAD(&bd->done_list);
|
|
INIT_HLIST_NODE(&bd->dev_list);
|
|
|
|
init_waitqueue_head(&bd->wq_free);
|
|
init_waitqueue_head(&bd->wq_done);
|
|
return bd;
|
|
}
|
|
|
|
static int bsg_put_device(struct bsg_device *bd)
|
|
{
|
|
int ret = 0;
|
|
|
|
mutex_lock(&bsg_mutex);
|
|
|
|
if (!atomic_dec_and_test(&bd->ref_count))
|
|
goto out;
|
|
|
|
dprintk("%s: tearing down\n", bd->name);
|
|
|
|
/*
|
|
* close can always block
|
|
*/
|
|
set_bit(BSG_F_BLOCK, &bd->flags);
|
|
|
|
/*
|
|
* correct error detection baddies here again. it's the responsibility
|
|
* of the app to properly reap commands before close() if it wants
|
|
* fool-proof error detection
|
|
*/
|
|
ret = bsg_complete_all_commands(bd);
|
|
|
|
blk_put_queue(bd->queue);
|
|
hlist_del(&bd->dev_list);
|
|
kfree(bd);
|
|
out:
|
|
mutex_unlock(&bsg_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static struct bsg_device *bsg_add_device(struct inode *inode,
|
|
struct request_queue *rq,
|
|
struct file *file)
|
|
{
|
|
struct bsg_device *bd;
|
|
#ifdef BSG_DEBUG
|
|
unsigned char buf[32];
|
|
#endif
|
|
|
|
bd = bsg_alloc_device();
|
|
if (!bd)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
bd->queue = rq;
|
|
kobject_get(&rq->kobj);
|
|
bsg_set_block(bd, file);
|
|
|
|
atomic_set(&bd->ref_count, 1);
|
|
bd->minor = iminor(inode);
|
|
mutex_lock(&bsg_mutex);
|
|
hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(bd->minor));
|
|
|
|
strncpy(bd->name, rq->bsg_dev.class_dev->class_id, sizeof(bd->name) - 1);
|
|
dprintk("bound to <%s>, max queue %d\n",
|
|
format_dev_t(buf, inode->i_rdev), bd->max_queue);
|
|
|
|
mutex_unlock(&bsg_mutex);
|
|
return bd;
|
|
}
|
|
|
|
static struct bsg_device *__bsg_get_device(int minor)
|
|
{
|
|
struct bsg_device *bd = NULL;
|
|
struct hlist_node *entry;
|
|
|
|
mutex_lock(&bsg_mutex);
|
|
|
|
hlist_for_each(entry, bsg_dev_idx_hash(minor)) {
|
|
bd = hlist_entry(entry, struct bsg_device, dev_list);
|
|
if (bd->minor == minor) {
|
|
atomic_inc(&bd->ref_count);
|
|
break;
|
|
}
|
|
|
|
bd = NULL;
|
|
}
|
|
|
|
mutex_unlock(&bsg_mutex);
|
|
return bd;
|
|
}
|
|
|
|
static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
|
|
{
|
|
struct bsg_device *bd = __bsg_get_device(iminor(inode));
|
|
struct bsg_class_device *bcd, *__bcd;
|
|
|
|
if (bd)
|
|
return bd;
|
|
|
|
/*
|
|
* find the class device
|
|
*/
|
|
bcd = NULL;
|
|
mutex_lock(&bsg_mutex);
|
|
list_for_each_entry(__bcd, &bsg_class_list, list) {
|
|
if (__bcd->minor == iminor(inode)) {
|
|
bcd = __bcd;
|
|
break;
|
|
}
|
|
}
|
|
mutex_unlock(&bsg_mutex);
|
|
|
|
if (!bcd)
|
|
return ERR_PTR(-ENODEV);
|
|
|
|
return bsg_add_device(inode, bcd->queue, file);
|
|
}
|
|
|
|
static int bsg_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct bsg_device *bd = bsg_get_device(inode, file);
|
|
|
|
if (IS_ERR(bd))
|
|
return PTR_ERR(bd);
|
|
|
|
file->private_data = bd;
|
|
return 0;
|
|
}
|
|
|
|
static int bsg_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct bsg_device *bd = file->private_data;
|
|
|
|
file->private_data = NULL;
|
|
return bsg_put_device(bd);
|
|
}
|
|
|
|
static unsigned int bsg_poll(struct file *file, poll_table *wait)
|
|
{
|
|
struct bsg_device *bd = file->private_data;
|
|
unsigned int mask = 0;
|
|
|
|
poll_wait(file, &bd->wq_done, wait);
|
|
poll_wait(file, &bd->wq_free, wait);
|
|
|
|
spin_lock_irq(&bd->lock);
|
|
if (!list_empty(&bd->done_list))
|
|
mask |= POLLIN | POLLRDNORM;
|
|
if (bd->queued_cmds >= bd->max_queue)
|
|
mask |= POLLOUT;
|
|
spin_unlock_irq(&bd->lock);
|
|
|
|
return mask;
|
|
}
|
|
|
|
static 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;
|
|
|
|
switch (cmd) {
|
|
/*
|
|
* our own ioctls
|
|
*/
|
|
case SG_GET_COMMAND_Q:
|
|
return put_user(bd->max_queue, uarg);
|
|
case SG_SET_COMMAND_Q: {
|
|
int queue;
|
|
|
|
if (get_user(queue, uarg))
|
|
return -EFAULT;
|
|
if (queue < 1)
|
|
return -EINVAL;
|
|
|
|
spin_lock_irq(&bd->lock);
|
|
bd->max_queue = queue;
|
|
spin_unlock_irq(&bd->lock);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* SCSI/sg ioctls
|
|
*/
|
|
case SG_GET_VERSION_NUM:
|
|
case SCSI_IOCTL_GET_IDLUN:
|
|
case SCSI_IOCTL_GET_BUS_NUMBER:
|
|
case SG_SET_TIMEOUT:
|
|
case SG_GET_TIMEOUT:
|
|
case SG_GET_RESERVED_SIZE:
|
|
case SG_SET_RESERVED_SIZE:
|
|
case SG_EMULATED_HOST:
|
|
case SCSI_IOCTL_SEND_COMMAND: {
|
|
void __user *uarg = (void __user *) arg;
|
|
return scsi_cmd_ioctl(file, bd->queue, NULL, cmd, uarg);
|
|
}
|
|
case SG_IO: {
|
|
struct request *rq;
|
|
struct bio *bio, *bidi_bio = NULL;
|
|
struct sg_io_v4 hdr;
|
|
|
|
if (copy_from_user(&hdr, uarg, sizeof(hdr)))
|
|
return -EFAULT;
|
|
|
|
rq = bsg_map_hdr(bd, &hdr);
|
|
if (IS_ERR(rq))
|
|
return PTR_ERR(rq);
|
|
|
|
bio = rq->bio;
|
|
if (rq->next_rq)
|
|
bidi_bio = rq->next_rq->bio;
|
|
blk_execute_rq(bd->queue, NULL, rq, 0);
|
|
blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
|
|
|
|
if (copy_to_user(uarg, &hdr, sizeof(hdr)))
|
|
return -EFAULT;
|
|
|
|
return 0;
|
|
}
|
|
/*
|
|
* block device ioctls
|
|
*/
|
|
default:
|
|
#if 0
|
|
return ioctl_by_bdev(bd->bdev, cmd, arg);
|
|
#else
|
|
return -ENOTTY;
|
|
#endif
|
|
}
|
|
}
|
|
|
|
static struct file_operations bsg_fops = {
|
|
.read = bsg_read,
|
|
.write = bsg_write,
|
|
.poll = bsg_poll,
|
|
.open = bsg_open,
|
|
.release = bsg_release,
|
|
.unlocked_ioctl = bsg_ioctl,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
void bsg_unregister_queue(struct request_queue *q)
|
|
{
|
|
struct bsg_class_device *bcd = &q->bsg_dev;
|
|
|
|
WARN_ON(!bcd->class_dev);
|
|
|
|
mutex_lock(&bsg_mutex);
|
|
sysfs_remove_link(&q->kobj, "bsg");
|
|
class_device_destroy(bsg_class, MKDEV(bsg_major, bcd->minor));
|
|
bcd->class_dev = NULL;
|
|
list_del_init(&bcd->list);
|
|
bsg_device_nr--;
|
|
mutex_unlock(&bsg_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(bsg_unregister_queue);
|
|
|
|
int bsg_register_queue(struct request_queue *q, const char *name)
|
|
{
|
|
struct bsg_class_device *bcd, *__bcd;
|
|
dev_t dev;
|
|
int ret = -EMFILE;
|
|
struct class_device *class_dev = NULL;
|
|
|
|
/*
|
|
* we need a proper transport to send commands, not a stacked device
|
|
*/
|
|
if (!q->request_fn)
|
|
return 0;
|
|
|
|
bcd = &q->bsg_dev;
|
|
memset(bcd, 0, sizeof(*bcd));
|
|
INIT_LIST_HEAD(&bcd->list);
|
|
|
|
mutex_lock(&bsg_mutex);
|
|
if (bsg_device_nr == BSG_MAX_DEVS) {
|
|
printk(KERN_ERR "bsg: too many bsg devices\n");
|
|
goto err;
|
|
}
|
|
|
|
retry:
|
|
list_for_each_entry(__bcd, &bsg_class_list, list) {
|
|
if (__bcd->minor == bsg_minor_idx) {
|
|
bsg_minor_idx++;
|
|
if (bsg_minor_idx == BSG_MAX_DEVS)
|
|
bsg_minor_idx = 0;
|
|
goto retry;
|
|
}
|
|
}
|
|
|
|
bcd->minor = bsg_minor_idx++;
|
|
if (bsg_minor_idx == BSG_MAX_DEVS)
|
|
bsg_minor_idx = 0;
|
|
|
|
bcd->queue = q;
|
|
dev = MKDEV(bsg_major, bcd->minor);
|
|
class_dev = class_device_create(bsg_class, NULL, dev, bcd->dev, "%s", name);
|
|
if (IS_ERR(class_dev)) {
|
|
ret = PTR_ERR(class_dev);
|
|
goto err;
|
|
}
|
|
bcd->class_dev = class_dev;
|
|
|
|
if (q->kobj.sd) {
|
|
ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
|
|
if (ret)
|
|
goto err;
|
|
}
|
|
|
|
list_add_tail(&bcd->list, &bsg_class_list);
|
|
bsg_device_nr++;
|
|
|
|
mutex_unlock(&bsg_mutex);
|
|
return 0;
|
|
err:
|
|
if (class_dev)
|
|
class_device_destroy(bsg_class, MKDEV(bsg_major, bcd->minor));
|
|
mutex_unlock(&bsg_mutex);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(bsg_register_queue);
|
|
|
|
static int bsg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
|
|
{
|
|
int ret;
|
|
struct scsi_device *sdp = to_scsi_device(cl_dev->dev);
|
|
struct request_queue *rq = sdp->request_queue;
|
|
|
|
if (rq->kobj.parent)
|
|
ret = bsg_register_queue(rq, kobject_name(rq->kobj.parent));
|
|
else
|
|
ret = bsg_register_queue(rq, kobject_name(&sdp->sdev_gendev.kobj));
|
|
return ret;
|
|
}
|
|
|
|
static void bsg_remove(struct class_device *cl_dev, struct class_interface *cl_intf)
|
|
{
|
|
bsg_unregister_queue(to_scsi_device(cl_dev->dev)->request_queue);
|
|
}
|
|
|
|
static struct class_interface bsg_intf = {
|
|
.add = bsg_add,
|
|
.remove = bsg_remove,
|
|
};
|
|
|
|
static struct cdev bsg_cdev = {
|
|
.kobj = {.name = "bsg", },
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int __init bsg_init(void)
|
|
{
|
|
int ret, i;
|
|
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;
|
|
}
|
|
|
|
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;
|
|
|
|
ret = scsi_register_interface(&bsg_intf);
|
|
if (ret)
|
|
goto remove_cdev;
|
|
|
|
printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
|
|
" loaded (major %d)\n", bsg_major);
|
|
return 0;
|
|
remove_cdev:
|
|
printk(KERN_ERR "bsg: failed register scsi interface %d\n", ret);
|
|
cdev_del(&bsg_cdev);
|
|
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);
|