Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 2474 insertions, 0 deletions

diff --git a/drivers/block/ub.c b/drivers/block/ub.c
new file mode 100644
index 00000000..fcec0225
--- /dev/null
+++ b/drivers/block/ub.c
@@ -0,0 +1,2474 @@
+/*
+ * The low performance USB storage driver (ub).
+ *
+ * Copyright (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
+ * Copyright (C) 2004 Pete Zaitcev (zaitcev@yahoo.com)
+ *
+ * This work is a part of Linux kernel, is derived from it,
+ * and is not licensed separately. See file COPYING for details.
+ *
+ * TODO (sorted by decreasing priority)
+ *  -- Return sense now that rq allows it (we always auto-sense anyway).
+ *  -- set readonly flag for CDs, set removable flag for CF readers
+ *  -- do inquiry and verify we got a disk and not a tape (for LUN mismatch)
+ *  -- verify the 13 conditions and do bulk resets
+ *  -- highmem
+ *  -- move top_sense and work_bcs into separate allocations (if they survive)
+ *     for cache purists and esoteric architectures.
+ *  -- Allocate structure for LUN 0 before the first ub_sync_tur, avoid NULL. ?
+ *  -- prune comments, they are too volumnous
+ *  -- Resove XXX's
+ *  -- CLEAR, CLR2STS, CLRRS seem to be ripe for refactoring.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/usb_usual.h>
+#include <linux/blkdev.h>
+#include <linux/timer.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <scsi/scsi.h>
+
+#define DRV_NAME "ub"
+
+#define UB_MAJOR 180
+
+/*
+ * The command state machine is the key model for understanding of this driver.
+ *
+ * The general rule is that all transitions are done towards the bottom
+ * of the diagram, thus preventing any loops.
+ *
+ * An exception to that is how the STAT state is handled. A counter allows it
+ * to be re-entered along the path marked with [C].
+ *
+ *       +--------+
+ *       ! INIT   !
+ *       +--------+
+ *           !
+ *        ub_scsi_cmd_start fails ->--------------------------------------\
+ *           !                                                            !
+ *           V                                                            !
+ *       +--------+                                                       !
+ *       ! CMD    !                                                       !
+ *       +--------+                                                       !
+ *           !                                            +--------+      !
+ *         was -EPIPE -->-------------------------------->! CLEAR  !      !
+ *           !                                            +--------+      !
+ *           !                                                !           !
+ *         was error -->------------------------------------- ! --------->\
+ *           !                                                !           !
+ *  /--<-- cmd->dir == NONE ?                                 !           !
+ *  !        !                                                !           !
+ *  !        V                                                !           !
+ *  !    +--------+                                           !           !
+ *  !    ! DATA   !                                           !           !
+ *  !    +--------+                                           !           !
+ *  !        !                           +---------+          !           !
+ *  !      was -EPIPE -->--------------->! CLR2STS !          !           !
+ *  !        !                           +---------+          !           !
+ *  !        !                                !               !           !
+ *  !        !                              was error -->---- ! --------->\
+ *  !      was error -->--------------------- ! ------------- ! --------->\
+ *  !        !                                !               !           !
+ *  !        V                                !               !           !
+ *  \--->+--------+                           !               !           !
+ *       ! STAT   !<--------------------------/               !           !
+ *  /--->+--------+                                           !           !
+ *  !        !                                                !           !
+ * [C]     was -EPIPE -->-----------\                         !           !
+ *  !        !                      !                         !           !
+ *  +<---- len == 0                 !                         !           !
+ *  !        !                      !                         !           !
+ *  !      was error -->--------------------------------------!---------->\
+ *  !        !                      !                         !           !
+ *  +<---- bad CSW                  !                         !           !
+ *  +<---- bad tag                  !                         !           !
+ *  !        !                      V                         !           !
+ *  !        !                 +--------+                     !           !
+ *  !        !                 ! CLRRS  !                     !           !
+ *  !        !                 +--------+                     !           !
+ *  !        !                      !                         !           !
+ *  \------- ! --------------------[C]--------\               !           !
+ *           !                                !               !           !
+ *         cmd->error---\                +--------+           !           !
+ *           !          +--------------->! SENSE  !<----------/           !
+ *         STAT_FAIL----/                +--------+                       !
+ *           !                                !                           V
+ *           !                                V                      +--------+
+ *           \--------------------------------\--------------------->! DONE   !
+ *                                                                   +--------+
+ */
+
+/*
+ * This many LUNs per USB device.
+ * Every one of them takes a host, see UB_MAX_HOSTS.
+ */
+#define UB_MAX_LUNS   9
+
+/*
+ */
+
+#define UB_PARTS_PER_LUN      8
+
+#define UB_MAX_CDB_SIZE      16		/* Corresponds to Bulk */
+
+#define UB_SENSE_SIZE  18
+
+/*
+ */
+struct ub_dev;
+
+#define UB_MAX_REQ_SG	9	/* cdrecord requires 32KB and maybe a header */
+#define UB_MAX_SECTORS 64
+
+/*
+ * A second is more than enough for a 32K transfer (UB_MAX_SECTORS)
+ * even if a webcam hogs the bus, but some devices need time to spin up.
+ */
+#define UB_URB_TIMEOUT	(HZ*2)
+#define UB_DATA_TIMEOUT	(HZ*5)	/* ZIP does spin-ups in the data phase */
+#define UB_STAT_TIMEOUT	(HZ*5)	/* Same spinups and eject for a dataless cmd. */
+#define UB_CTRL_TIMEOUT	(HZ/2)	/* 500ms ought to be enough to clear a stall */
+
+/*
+ * An instance of a SCSI command in transit.
+ */
+#define UB_DIR_NONE	0
+#define UB_DIR_READ	1
+#define UB_DIR_ILLEGAL2	2
+#define UB_DIR_WRITE	3
+
+#define UB_DIR_CHAR(c)  (((c)==UB_DIR_WRITE)? 'w': \
+			 (((c)==UB_DIR_READ)? 'r': 'n'))
+
+enum ub_scsi_cmd_state {
+	UB_CMDST_INIT,			/* Initial state */
+	UB_CMDST_CMD,			/* Command submitted */
+	UB_CMDST_DATA,			/* Data phase */
+	UB_CMDST_CLR2STS,		/* Clearing before requesting status */
+	UB_CMDST_STAT,			/* Status phase */
+	UB_CMDST_CLEAR,			/* Clearing a stall (halt, actually) */
+	UB_CMDST_CLRRS,			/* Clearing before retrying status */
+	UB_CMDST_SENSE,			/* Sending Request Sense */
+	UB_CMDST_DONE			/* Final state */
+};
+
+struct ub_scsi_cmd {
+	unsigned char cdb[UB_MAX_CDB_SIZE];
+	unsigned char cdb_len;
+
+	unsigned char dir;		/* 0 - none, 1 - read, 3 - write. */
+	enum ub_scsi_cmd_state state;
+	unsigned int tag;
+	struct ub_scsi_cmd *next;
+
+	int error;			/* Return code - valid upon done */
+	unsigned int act_len;		/* Return size */
+	unsigned char key, asc, ascq;	/* May be valid if error==-EIO */
+
+	int stat_count;			/* Retries getting status. */
+	unsigned int timeo;		/* jiffies until rq->timeout changes */
+
+	unsigned int len;		/* Requested length */
+	unsigned int current_sg;
+	unsigned int nsg;		/* sgv[nsg] */
+	struct scatterlist sgv[UB_MAX_REQ_SG];
+
+	struct ub_lun *lun;
+	void (*done)(struct ub_dev *, struct ub_scsi_cmd *);
+	void *back;
+};
+
+struct ub_request {
+	struct request *rq;
+	unsigned int current_try;
+	unsigned int nsg;		/* sgv[nsg] */
+	struct scatterlist sgv[UB_MAX_REQ_SG];
+};
+
+/*
+ */
+struct ub_capacity {
+	unsigned long nsec;		/* Linux size - 512 byte sectors */
+	unsigned int bsize;		/* Linux hardsect_size */
+	unsigned int bshift;		/* Shift between 512 and hard sects */
+};
+
+/*
+ * This is a direct take-off from linux/include/completion.h
+ * The difference is that I do not wait on this thing, just poll.
+ * When I want to wait (ub_probe), I just use the stock completion.
+ *
+ * Note that INIT_COMPLETION takes no lock. It is correct. But why
+ * in the bloody hell that thing takes struct instead of pointer to struct
+ * is quite beyond me. I just copied it from the stock completion.
+ */
+struct ub_completion {
+	unsigned int done;
+	spinlock_t lock;
+};
+
+static DEFINE_MUTEX(ub_mutex);
+static inline void ub_init_completion(struct ub_completion *x)
+{
+	x->done = 0;
+	spin_lock_init(&x->lock);
+}
+
+#define UB_INIT_COMPLETION(x)	((x).done = 0)
+
+static void ub_complete(struct ub_completion *x)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&x->lock, flags);
+	x->done++;
+	spin_unlock_irqrestore(&x->lock, flags);
+}
+
+static int ub_is_completed(struct ub_completion *x)
+{
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&x->lock, flags);
+	ret = x->done;
+	spin_unlock_irqrestore(&x->lock, flags);
+	return ret;
+}
+
+/*
+ */
+struct ub_scsi_cmd_queue {
+	int qlen, qmax;
+	struct ub_scsi_cmd *head, *tail;
+};
+
+/*
+ * The block device instance (one per LUN).
+ */
+struct ub_lun {
+	struct ub_dev *udev;
+	struct list_head link;
+	struct gendisk *disk;
+	int id;				/* Host index */
+	int num;			/* LUN number */
+	char name[16];
+
+	int changed;			/* Media was changed */
+	int removable;
+	int readonly;
+
+	struct ub_request urq;
+
+	/* Use Ingo's mempool if or when we have more than one command. */
+	/*
+	 * Currently we never need more than one command for the whole device.
+	 * However, giving every LUN a command is a cheap and automatic way
+	 * to enforce fairness between them.
+	 */
+	int cmda[1];
+	struct ub_scsi_cmd cmdv[1];
+
+	struct ub_capacity capacity; 
+};
+
+/*
+ * The USB device instance.
+ */
+struct ub_dev {
+	spinlock_t *lock;
+	atomic_t poison;		/* The USB device is disconnected */
+	int openc;			/* protected by ub_lock! */
+					/* kref is too implicit for our taste */
+	int reset;			/* Reset is running */
+	int bad_resid;
+	unsigned int tagcnt;
+	char name[12];
+	struct usb_device *dev;
+	struct usb_interface *intf;
+
+	struct list_head luns;
+
+	unsigned int send_bulk_pipe;	/* cached pipe values */
+	unsigned int recv_bulk_pipe;
+	unsigned int send_ctrl_pipe;
+	unsigned int recv_ctrl_pipe;
+
+	struct tasklet_struct tasklet;
+
+	struct ub_scsi_cmd_queue cmd_queue;
+	struct ub_scsi_cmd top_rqs_cmd;	/* REQUEST SENSE */
+	unsigned char top_sense[UB_SENSE_SIZE];
+
+	struct ub_completion work_done;
+	struct urb work_urb;
+	struct timer_list work_timer;
+	int last_pipe;			/* What might need clearing */
+	__le32 signature;		/* Learned signature */
+	struct bulk_cb_wrap work_bcb;
+	struct bulk_cs_wrap work_bcs;
+	struct usb_ctrlrequest work_cr;
+
+	struct work_struct reset_work;
+	wait_queue_head_t reset_wait;
+};
+
+/*
+ */
+static void ub_cleanup(struct ub_dev *sc);
+static int ub_request_fn_1(struct ub_lun *lun, struct request *rq);
+static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_scsi_cmd *cmd, struct ub_request *urq);
+static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_scsi_cmd *cmd, struct ub_request *urq);
+static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
+static void ub_end_rq(struct request *rq, unsigned int status);
+static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_request *urq, struct ub_scsi_cmd *cmd);
+static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
+static void ub_urb_complete(struct urb *urb);
+static void ub_scsi_action(unsigned long _dev);
+static void ub_scsi_dispatch(struct ub_dev *sc);
+static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
+static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
+static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc);
+static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
+static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
+static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
+static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
+static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
+    int stalled_pipe);
+static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd);
+static void ub_reset_enter(struct ub_dev *sc, int try);
+static void ub_reset_task(struct work_struct *work);
+static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun);
+static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_capacity *ret);
+static int ub_sync_reset(struct ub_dev *sc);
+static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe);
+static int ub_probe_lun(struct ub_dev *sc, int lnum);
+
+/*
+ */
+#ifdef CONFIG_USB_LIBUSUAL
+
+#define ub_usb_ids  usb_storage_usb_ids
+#else
+
+static const struct usb_device_id ub_usb_ids[] = {
+	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(usb, ub_usb_ids);
+#endif /* CONFIG_USB_LIBUSUAL */
+
+/*
+ * Find me a way to identify "next free minor" for add_disk(),
+ * and the array disappears the next day. However, the number of
+ * hosts has something to do with the naming and /proc/partitions.
+ * This has to be thought out in detail before changing.
+ * If UB_MAX_HOST was 1000, we'd use a bitmap. Or a better data structure.
+ */
+#define UB_MAX_HOSTS  26
+static char ub_hostv[UB_MAX_HOSTS];
+
+#define UB_QLOCK_NUM 5
+static spinlock_t ub_qlockv[UB_QLOCK_NUM];
+static int ub_qlock_next = 0;
+
+static DEFINE_SPINLOCK(ub_lock);	/* Locks globals and ->openc */
+
+/*
+ * The id allocator.
+ *
+ * This also stores the host for indexing by minor, which is somewhat dirty.
+ */
+static int ub_id_get(void)
+{
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&ub_lock, flags);
+	for (i = 0; i < UB_MAX_HOSTS; i++) {
+		if (ub_hostv[i] == 0) {
+			ub_hostv[i] = 1;
+			spin_unlock_irqrestore(&ub_lock, flags);
+			return i;
+		}
+	}
+	spin_unlock_irqrestore(&ub_lock, flags);
+	return -1;
+}
+
+static void ub_id_put(int id)
+{
+	unsigned long flags;
+
+	if (id < 0 || id >= UB_MAX_HOSTS) {
+		printk(KERN_ERR DRV_NAME ": bad host ID %d\n", id);
+		return;
+	}
+
+	spin_lock_irqsave(&ub_lock, flags);
+	if (ub_hostv[id] == 0) {
+		spin_unlock_irqrestore(&ub_lock, flags);
+		printk(KERN_ERR DRV_NAME ": freeing free host ID %d\n", id);
+		return;
+	}
+	ub_hostv[id] = 0;
+	spin_unlock_irqrestore(&ub_lock, flags);
+}
+
+/*
+ * This is necessitated by the fact that blk_cleanup_queue does not
+ * necesserily destroy the queue. Instead, it may merely decrease q->refcnt.
+ * Since our blk_init_queue() passes a spinlock common with ub_dev,
+ * we have life time issues when ub_cleanup frees ub_dev.
+ */
+static spinlock_t *ub_next_lock(void)
+{
+	unsigned long flags;
+	spinlock_t *ret;
+
+	spin_lock_irqsave(&ub_lock, flags);
+	ret = &ub_qlockv[ub_qlock_next];
+	ub_qlock_next = (ub_qlock_next + 1) % UB_QLOCK_NUM;
+	spin_unlock_irqrestore(&ub_lock, flags);
+	return ret;
+}
+
+/*
+ * Downcount for deallocation. This rides on two assumptions:
+ *  - once something is poisoned, its refcount cannot grow
+ *  - opens cannot happen at this time (del_gendisk was done)
+ * If the above is true, we can drop the lock, which we need for
+ * blk_cleanup_queue(): the silly thing may attempt to sleep.
+ * [Actually, it never needs to sleep for us, but it calls might_sleep()]
+ */
+static void ub_put(struct ub_dev *sc)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ub_lock, flags);
+	--sc->openc;
+	if (sc->openc == 0 && atomic_read(&sc->poison)) {
+		spin_unlock_irqrestore(&ub_lock, flags);
+		ub_cleanup(sc);
+	} else {
+		spin_unlock_irqrestore(&ub_lock, flags);
+	}
+}
+
+/*
+ * Final cleanup and deallocation.
+ */
+static void ub_cleanup(struct ub_dev *sc)
+{
+	struct list_head *p;
+	struct ub_lun *lun;
+	struct request_queue *q;
+
+	while (!list_empty(&sc->luns)) {
+		p = sc->luns.next;
+		lun = list_entry(p, struct ub_lun, link);
+		list_del(p);
+
+		/* I don't think queue can be NULL. But... Stolen from sx8.c */
+		if ((q = lun->disk->queue) != NULL)
+			blk_cleanup_queue(q);
+		/*
+		 * If we zero disk->private_data BEFORE put_disk, we have
+		 * to check for NULL all over the place in open, release,
+		 * check_media and revalidate, because the block level
+		 * semaphore is well inside the put_disk.
+		 * But we cannot zero after the call, because *disk is gone.
+		 * The sd.c is blatantly racy in this area.
+		 */
+		/* disk->private_data = NULL; */
+		put_disk(lun->disk);
+		lun->disk = NULL;
+
+		ub_id_put(lun->id);
+		kfree(lun);
+	}
+
+	usb_set_intfdata(sc->intf, NULL);
+	usb_put_intf(sc->intf);
+	usb_put_dev(sc->dev);
+	kfree(sc);
+}
+
+/*
+ * The "command allocator".
+ */
+static struct ub_scsi_cmd *ub_get_cmd(struct ub_lun *lun)
+{
+	struct ub_scsi_cmd *ret;
+
+	if (lun->cmda[0])
+		return NULL;
+	ret = &lun->cmdv[0];
+	lun->cmda[0] = 1;
+	return ret;
+}
+
+static void ub_put_cmd(struct ub_lun *lun, struct ub_scsi_cmd *cmd)
+{
+	if (cmd != &lun->cmdv[0]) {
+		printk(KERN_WARNING "%s: releasing a foreign cmd %p\n",
+		    lun->name, cmd);
+		return;
+	}
+	if (!lun->cmda[0]) {
+		printk(KERN_WARNING "%s: releasing a free cmd\n", lun->name);
+		return;
+	}
+	lun->cmda[0] = 0;
+}
+
+/*
+ * The command queue.
+ */
+static void ub_cmdq_add(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+	struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
+
+	if (t->qlen++ == 0) {
+		t->head = cmd;
+		t->tail = cmd;
+	} else {
+		t->tail->next = cmd;
+		t->tail = cmd;
+	}
+
+	if (t->qlen > t->qmax)
+		t->qmax = t->qlen;
+}
+
+static void ub_cmdq_insert(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+	struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
+
+	if (t->qlen++ == 0) {
+		t->head = cmd;
+		t->tail = cmd;
+	} else {
+		cmd->next = t->head;
+		t->head = cmd;
+	}
+
+	if (t->qlen > t->qmax)
+		t->qmax = t->qlen;
+}
+
+static struct ub_scsi_cmd *ub_cmdq_pop(struct ub_dev *sc)
+{
+	struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
+	struct ub_scsi_cmd *cmd;
+
+	if (t->qlen == 0)
+		return NULL;
+	if (--t->qlen == 0)
+		t->tail = NULL;
+	cmd = t->head;
+	t->head = cmd->next;
+	cmd->next = NULL;
+	return cmd;
+}
+
+#define ub_cmdq_peek(sc)  ((sc)->cmd_queue.head)
+
+/*
+ * The request function is our main entry point
+ */
+
+static void ub_request_fn(struct request_queue *q)
+{
+	struct ub_lun *lun = q->queuedata;
+	struct request *rq;
+
+	while ((rq = blk_peek_request(q)) != NULL) {
+		if (ub_request_fn_1(lun, rq) != 0) {
+			blk_stop_queue(q);
+			break;
+		}
+	}
+}
+
+static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
+{
+	struct ub_dev *sc = lun->udev;
+	struct ub_scsi_cmd *cmd;
+	struct ub_request *urq;
+	int n_elem;
+
+	if (atomic_read(&sc->poison)) {
+		blk_start_request(rq);
+		ub_end_rq(rq, DID_NO_CONNECT << 16);
+		return 0;
+	}
+
+	if (lun->changed && rq->cmd_type != REQ_TYPE_BLOCK_PC) {
+		blk_start_request(rq);
+		ub_end_rq(rq, SAM_STAT_CHECK_CONDITION);
+		return 0;
+	}
+
+	if (lun->urq.rq != NULL)
+		return -1;
+	if ((cmd = ub_get_cmd(lun)) == NULL)
+		return -1;
+	memset(cmd, 0, sizeof(struct ub_scsi_cmd));
+
+	blk_start_request(rq);
+
+	urq = &lun->urq;
+	memset(urq, 0, sizeof(struct ub_request));
+	urq->rq = rq;
+
+	/*
+	 * get scatterlist from block layer
+	 */
+	sg_init_table(&urq->sgv[0], UB_MAX_REQ_SG);
+	n_elem = blk_rq_map_sg(lun->disk->queue, rq, &urq->sgv[0]);
+	if (n_elem < 0) {
+		/* Impossible, because blk_rq_map_sg should not hit ENOMEM. */
+		printk(KERN_INFO "%s: failed request map (%d)\n",
+		    lun->name, n_elem);
+		goto drop;
+	}
+	if (n_elem > UB_MAX_REQ_SG) {	/* Paranoia */
+		printk(KERN_WARNING "%s: request with %d segments\n",
+		    lun->name, n_elem);
+		goto drop;
+	}
+	urq->nsg = n_elem;
+
+	if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
+		ub_cmd_build_packet(sc, lun, cmd, urq);
+	} else {
+		ub_cmd_build_block(sc, lun, cmd, urq);
+	}
+	cmd->state = UB_CMDST_INIT;
+	cmd->lun = lun;
+	cmd->done = ub_rw_cmd_done;
+	cmd->back = urq;
+
+	cmd->tag = sc->tagcnt++;
+	if (ub_submit_scsi(sc, cmd) != 0)
+		goto drop;
+
+	return 0;
+
+drop:
+	ub_put_cmd(lun, cmd);
+	ub_end_rq(rq, DID_ERROR << 16);
+	return 0;
+}
+
+static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_scsi_cmd *cmd, struct ub_request *urq)
+{
+	struct request *rq = urq->rq;
+	unsigned int block, nblks;
+
+	if (rq_data_dir(rq) == WRITE)
+		cmd->dir = UB_DIR_WRITE;
+	else
+		cmd->dir = UB_DIR_READ;
+
+	cmd->nsg = urq->nsg;
+	memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
+
+	/*
+	 * build the command
+	 *
+	 * The call to blk_queue_logical_block_size() guarantees that request
+	 * is aligned, but it is given in terms of 512 byte units, always.
+	 */
+	block = blk_rq_pos(rq) >> lun->capacity.bshift;
+	nblks = blk_rq_sectors(rq) >> lun->capacity.bshift;
+
+	cmd->cdb[0] = (cmd->dir == UB_DIR_READ)? READ_10: WRITE_10;
+	/* 10-byte uses 4 bytes of LBA: 2147483648KB, 2097152MB, 2048GB */
+	cmd->cdb[2] = block >> 24;
+	cmd->cdb[3] = block >> 16;
+	cmd->cdb[4] = block >> 8;
+	cmd->cdb[5] = block;
+	cmd->cdb[7] = nblks >> 8;
+	cmd->cdb[8] = nblks;
+	cmd->cdb_len = 10;
+
+	cmd->len = blk_rq_bytes(rq);
+}
+
+static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_scsi_cmd *cmd, struct ub_request *urq)
+{
+	struct request *rq = urq->rq;
+
+	if (blk_rq_bytes(rq) == 0) {
+		cmd->dir = UB_DIR_NONE;
+	} else {
+		if (rq_data_dir(rq) == WRITE)
+			cmd->dir = UB_DIR_WRITE;
+		else
+			cmd->dir = UB_DIR_READ;
+	}
+
+	cmd->nsg = urq->nsg;
+	memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
+
+	memcpy(&cmd->cdb, rq->cmd, rq->cmd_len);
+	cmd->cdb_len = rq->cmd_len;
+
+	cmd->len = blk_rq_bytes(rq);
+
+	/*
+	 * To reapply this to every URB is not as incorrect as it looks.
+	 * In return, we avoid any complicated tracking calculations.
+	 */
+	cmd->timeo = rq->timeout;
+}
+
+static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+	struct ub_lun *lun = cmd->lun;
+	struct ub_request *urq = cmd->back;
+	struct request *rq;
+	unsigned int scsi_status;
+
+	rq = urq->rq;
+
+	if (cmd->error == 0) {
+		if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
+			if (cmd->act_len >= rq->resid_len)
+				rq->resid_len = 0;
+			else
+				rq->resid_len -= cmd->act_len;
+			scsi_status = 0;
+		} else {
+			if (cmd->act_len != cmd->len) {
+				scsi_status = SAM_STAT_CHECK_CONDITION;
+			} else {
+				scsi_status = 0;
+			}
+		}
+	} else {
+		if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
+			/* UB_SENSE_SIZE is smaller than SCSI_SENSE_BUFFERSIZE */
+			memcpy(rq->sense, sc->top_sense, UB_SENSE_SIZE);
+			rq->sense_len = UB_SENSE_SIZE;
+			if (sc->top_sense[0] != 0)
+				scsi_status = SAM_STAT_CHECK_CONDITION;
+			else
+				scsi_status = DID_ERROR << 16;
+		} else {
+			if (cmd->error == -EIO &&
+			    (cmd->key == 0 ||
+			     cmd->key == MEDIUM_ERROR ||
+			     cmd->key == UNIT_ATTENTION)) {
+				if (ub_rw_cmd_retry(sc, lun, urq, cmd) == 0)
+					return;
+			}
+			scsi_status = SAM_STAT_CHECK_CONDITION;
+		}
+	}
+
+	urq->rq = NULL;
+
+	ub_put_cmd(lun, cmd);
+	ub_end_rq(rq, scsi_status);
+	blk_start_queue(lun->disk->queue);
+}
+
+static void ub_end_rq(struct request *rq, unsigned int scsi_status)
+{
+	int error;
+
+	if (scsi_status == 0) {
+		error = 0;
+	} else {
+		error = -EIO;
+		rq->errors = scsi_status;
+	}
+	__blk_end_request_all(rq, error);
+}
+
+static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_request *urq, struct ub_scsi_cmd *cmd)
+{
+
+	if (atomic_read(&sc->poison))
+		return -ENXIO;
+
+	ub_reset_enter(sc, urq->current_try);
+
+	if (urq->current_try >= 3)
+		return -EIO;
+	urq->current_try++;
+
+	/* Remove this if anyone complains of flooding. */
+	printk(KERN_DEBUG "%s: dir %c len/act %d/%d "
+	    "[sense %x %02x %02x] retry %d\n",
+	    sc->name, UB_DIR_CHAR(cmd->dir), cmd->len, cmd->act_len,
+	    cmd->key, cmd->asc, cmd->ascq, urq->current_try);
+
+	memset(cmd, 0, sizeof(struct ub_scsi_cmd));
+	ub_cmd_build_block(sc, lun, cmd, urq);
+
+	cmd->state = UB_CMDST_INIT;
+	cmd->lun = lun;
+	cmd->done = ub_rw_cmd_done;
+	cmd->back = urq;
+
+	cmd->tag = sc->tagcnt++;
+
+#if 0 /* Wasteful */
+	return ub_submit_scsi(sc, cmd);
+#else
+	ub_cmdq_add(sc, cmd);
+	return 0;
+#endif
+}
+
+/*
+ * Submit a regular SCSI operation (not an auto-sense).
+ *
+ * The Iron Law of Good Submit Routine is:
+ * Zero return - callback is done, Nonzero return - callback is not done.
+ * No exceptions.
+ *
+ * Host is assumed locked.
+ */
+static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+
+	if (cmd->state != UB_CMDST_INIT ||
+	    (cmd->dir != UB_DIR_NONE && cmd->len == 0)) {
+		return -EINVAL;
+	}
+
+	ub_cmdq_add(sc, cmd);
+	/*
+	 * We can call ub_scsi_dispatch(sc) right away here, but it's a little
+	 * safer to jump to a tasklet, in case upper layers do something silly.
+	 */
+	tasklet_schedule(&sc->tasklet);
+	return 0;
+}
+
+/*
+ * Submit the first URB for the queued command.
+ * This function does not deal with queueing in any way.
+ */
+static int ub_scsi_cmd_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+	struct bulk_cb_wrap *bcb;
+	int rc;
+
+	bcb = &sc->work_bcb;
+
+	/*
+	 * ``If the allocation length is eighteen or greater, and a device
+	 * server returns less than eithteen bytes of data, the application
+	 * client should assume that the bytes not transferred would have been
+	 * zeroes had the device server returned those bytes.''
+	 *
+	 * We zero sense for all commands so that when a packet request
+	 * fails it does not return a stale sense.
+	 */
+	memset(&sc->top_sense, 0, UB_SENSE_SIZE);
+
+	/* set up the command wrapper */
+	bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
+	bcb->Tag = cmd->tag;		/* Endianness is not important */
+	bcb->DataTransferLength = cpu_to_le32(cmd->len);
+	bcb->Flags = (cmd->dir == UB_DIR_READ) ? 0x80 : 0;
+	bcb->Lun = (cmd->lun != NULL) ? cmd->lun->num : 0;
+	bcb->Length = cmd->cdb_len;
+
+	/* copy the command payload */
+	memcpy(bcb->CDB, cmd->cdb, UB_MAX_CDB_SIZE);
+
+	UB_INIT_COMPLETION(sc->work_done);
+
+	sc->last_pipe = sc->send_bulk_pipe;
+	usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->send_bulk_pipe,
+	    bcb, US_BULK_CB_WRAP_LEN, ub_urb_complete, sc);
+
+	if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
+		/* XXX Clear stalls */
+		ub_complete(&sc->work_done);
+		return rc;
+	}
+
+	sc->work_timer.expires = jiffies + UB_URB_TIMEOUT;
+	add_timer(&sc->work_timer);
+
+	cmd->state = UB_CMDST_CMD;
+	return 0;
+}
+
+/*
+ * Timeout handler.
+ */
+static void ub_urb_timeout(unsigned long arg)
+{
+	struct ub_dev *sc = (struct ub_dev *) arg;
+	unsigned long flags;
+
+	spin_lock_irqsave(sc->lock, flags);
+	if (!ub_is_completed(&sc->work_done))
+		usb_unlink_urb(&sc->work_urb);
+	spin_unlock_irqrestore(sc->lock, flags);
+}
+
+/*
+ * Completion routine for the work URB.
+ *
+ * This can be called directly from usb_submit_urb (while we have
+ * the sc->lock taken) and from an interrupt (while we do NOT have
+ * the sc->lock taken). Therefore, bounce this off to a tasklet.
+ */
+static void ub_urb_complete(struct urb *urb)
+{
+	struct ub_dev *sc = urb->context;
+
+	ub_complete(&sc->work_done);
+	tasklet_schedule(&sc->tasklet);
+}
+
+static void ub_scsi_action(unsigned long _dev)
+{
+	struct ub_dev *sc = (struct ub_dev *) _dev;
+	unsigned long flags;
+
+	spin_lock_irqsave(sc->lock, flags);
+	ub_scsi_dispatch(sc);
+	spin_unlock_irqrestore(sc->lock, flags);
+}
+
+static void ub_scsi_dispatch(struct ub_dev *sc)
+{
+	struct ub_scsi_cmd *cmd;
+	int rc;
+
+	while (!sc->reset && (cmd = ub_cmdq_peek(sc)) != NULL) {
+		if (cmd->state == UB_CMDST_DONE) {
+			ub_cmdq_pop(sc);
+			(*cmd->done)(sc, cmd);
+		} else if (cmd->state == UB_CMDST_INIT) {
+			if ((rc = ub_scsi_cmd_start(sc, cmd)) == 0)
+				break;
+			cmd->error = rc;
+			cmd->state = UB_CMDST_DONE;
+		} else {
+			if (!ub_is_completed(&sc->work_done))
+				break;
+			del_timer(&sc->work_timer);
+			ub_scsi_urb_compl(sc, cmd);
+		}
+	}
+}
+
+static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+	struct urb *urb = &sc->work_urb;
+	struct bulk_cs_wrap *bcs;
+	int endp;
+	int len;
+	int rc;
+
+	if (atomic_read(&sc->poison)) {
+		ub_state_done(sc, cmd, -ENODEV);
+		return;
+	}
+
+	endp = usb_pipeendpoint(sc->last_pipe);
+	if (usb_pipein(sc->last_pipe))
+		endp |= USB_DIR_IN;
+
+	if (cmd->state == UB_CMDST_CLEAR) {
+		if (urb->status == -EPIPE) {
+			/*
+			 * STALL while clearning STALL.
+			 * The control pipe clears itself - nothing to do.
+			 */
+			printk(KERN_NOTICE "%s: stall on control pipe\n",
+			    sc->name);
+			goto Bad_End;
+		}
+
+		/*
+		 * We ignore the result for the halt clear.
+		 */
+
+		usb_reset_endpoint(sc->dev, endp);
+
+		ub_state_sense(sc, cmd);
+
+	} else if (cmd->state == UB_CMDST_CLR2STS) {
+		if (urb->status == -EPIPE) {
+			printk(KERN_NOTICE "%s: stall on control pipe\n",
+			    sc->name);
+			goto Bad_End;
+		}
+
+		/*
+		 * We ignore the result for the halt clear.
+		 */
+
+		usb_reset_endpoint(sc->dev, endp);
+
+		ub_state_stat(sc, cmd);
+
+	} else if (cmd->state == UB_CMDST_CLRRS) {
+		if (urb->status == -EPIPE) {
+			printk(KERN_NOTICE "%s: stall on control pipe\n",
+			    sc->name);
+			goto Bad_End;
+		}
+
+		/*
+		 * We ignore the result for the halt clear.
+		 */
+
+		usb_reset_endpoint(sc->dev, endp);
+
+		ub_state_stat_counted(sc, cmd);
+
+	} else if (cmd->state == UB_CMDST_CMD) {
+		switch (urb->status) {
+		case 0:
+			break;
+		case -EOVERFLOW:
+			goto Bad_End;
+		case -EPIPE:
+			rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
+			if (rc != 0) {
+				printk(KERN_NOTICE "%s: "
+				    "unable to submit clear (%d)\n",
+				    sc->name, rc);
+				/*
+				 * This is typically ENOMEM or some other such shit.
+				 * Retrying is pointless. Just do Bad End on it...
+				 */
+				ub_state_done(sc, cmd, rc);
+				return;
+			}
+			cmd->state = UB_CMDST_CLEAR;
+			return;
+		case -ESHUTDOWN:	/* unplug */
+		case -EILSEQ:		/* unplug timeout on uhci */
+			ub_state_done(sc, cmd, -ENODEV);
+			return;
+		default:
+			goto Bad_End;
+		}
+		if (urb->actual_length != US_BULK_CB_WRAP_LEN) {
+			goto Bad_End;
+		}
+
+		if (cmd->dir == UB_DIR_NONE || cmd->nsg < 1) {
+			ub_state_stat(sc, cmd);
+			return;
+		}
+
+		// udelay(125);		// usb-storage has this
+		ub_data_start(sc, cmd);
+
+	} else if (cmd->state == UB_CMDST_DATA) {
+		if (urb->status == -EPIPE) {
+			rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
+			if (rc != 0) {
+				printk(KERN_NOTICE "%s: "
+				    "unable to submit clear (%d)\n",
+				    sc->name, rc);
+				ub_state_done(sc, cmd, rc);
+				return;
+			}
+			cmd->state = UB_CMDST_CLR2STS;
+			return;
+		}
+		if (urb->status == -EOVERFLOW) {
+			/*
+			 * A babble? Failure, but we must transfer CSW now.
+			 */
+			cmd->error = -EOVERFLOW;	/* A cheap trick... */
+			ub_state_stat(sc, cmd);
+			return;
+		}
+
+		if (cmd->dir == UB_DIR_WRITE) {
+			/*
+			 * Do not continue writes in case of a failure.
+			 * Doing so would cause sectors to be mixed up,
+			 * which is worse than sectors lost.
+			 *
+			 * We must try to read the CSW, or many devices
+			 * get confused.
+			 */
+			len = urb->actual_length;
+			if (urb->status != 0 ||
+			    len != cmd->sgv[cmd->current_sg].length) {
+				cmd->act_len += len;
+
+				cmd->error = -EIO;
+				ub_state_stat(sc, cmd);
+				return;
+			}
+
+		} else {
+			/*
+			 * If an error occurs on read, we record it, and
+			 * continue to fetch data in order to avoid bubble.
+			 *
+			 * As a small shortcut, we stop if we detect that
+			 * a CSW mixed into data.
+			 */
+			if (urb->status != 0)
+				cmd->error = -EIO;
+
+			len = urb->actual_length;
+			if (urb->status != 0 ||
+			    len != cmd->sgv[cmd->current_sg].length) {
+				if ((len & 0x1FF) == US_BULK_CS_WRAP_LEN)
+					goto Bad_End;
+			}
+		}
+
+		cmd->act_len += urb->actual_length;
+
+		if (++cmd->current_sg < cmd->nsg) {
+			ub_data_start(sc, cmd);
+			return;
+		}
+		ub_state_stat(sc, cmd);
+
+	} else if (cmd->state == UB_CMDST_STAT) {
+		if (urb->status == -EPIPE) {
+			rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
+			if (rc != 0) {
+				printk(KERN_NOTICE "%s: "
+				    "unable to submit clear (%d)\n",
+				    sc->name, rc);
+				ub_state_done(sc, cmd, rc);
+				return;
+			}
+
+			/*
+			 * Having a stall when getting CSW is an error, so
+			 * make sure uppper levels are not oblivious to it.
+			 */
+			cmd->error = -EIO;		/* A cheap trick... */
+
+			cmd->state = UB_CMDST_CLRRS;
+			return;
+		}
+
+		/* Catch everything, including -EOVERFLOW and other nasties. */
+		if (urb->status != 0)
+			goto Bad_End;
+
+		if (urb->actual_length == 0) {
+			ub_state_stat_counted(sc, cmd);
+			return;
+		}
+
+		/*
+		 * Check the returned Bulk protocol status.
+		 * The status block has to be validated first.
+		 */
+
+		bcs = &sc->work_bcs;
+
+		if (sc->signature == cpu_to_le32(0)) {
+			/*
+			 * This is the first reply, so do not perform the check.
+			 * Instead, remember the signature the device uses
+			 * for future checks. But do not allow a nul.
+			 */
+			sc->signature = bcs->Signature;
+			if (sc->signature == cpu_to_le32(0)) {
+				ub_state_stat_counted(sc, cmd);
+				return;
+			}
+		} else {
+			if (bcs->Signature != sc->signature) {
+				ub_state_stat_counted(sc, cmd);
+				return;
+			}
+		}
+
+		if (bcs->Tag != cmd->tag) {
+			/*
+			 * This usually happens when we disagree with the
+			 * device's microcode about something. For instance,
+			 * a few of them throw this after timeouts. They buffer
+			 * commands and reply at commands we timed out before.
+			 * Without flushing these replies we loop forever.
+			 */
+			ub_state_stat_counted(sc, cmd);
+			return;
+		}
+
+		if (!sc->bad_resid) {
+			len = le32_to_cpu(bcs->Residue);
+			if (len != cmd->len - cmd->act_len) {
+				/*
+				 * Only start ignoring if this cmd ended well.
+				 */
+				if (cmd->len == cmd->act_len) {
+					printk(KERN_NOTICE "%s: "
+					    "bad residual %d of %d, ignoring\n",
+					    sc->name, len, cmd->len);
+					sc->bad_resid = 1;
+				}
+			}
+		}
+
+		switch (bcs->Status) {
+		case US_BULK_STAT_OK:
+			break;
+		case US_BULK_STAT_FAIL:
+			ub_state_sense(sc, cmd);
+			return;
+		case US_BULK_STAT_PHASE:
+			goto Bad_End;
+		default:
+			printk(KERN_INFO "%s: unknown CSW status 0x%x\n",
+			    sc->name, bcs->Status);
+			ub_state_done(sc, cmd, -EINVAL);
+			return;
+		}
+
+		/* Not zeroing error to preserve a babble indicator */
+		if (cmd->error != 0) {
+			ub_state_sense(sc, cmd);
+			return;
+		}
+		cmd->state = UB_CMDST_DONE;
+		ub_cmdq_pop(sc);
+		(*cmd->done)(sc, cmd);
+
+	} else if (cmd->state == UB_CMDST_SENSE) {
+		ub_state_done(sc, cmd, -EIO);
+
+	} else {
+		printk(KERN_WARNING "%s: wrong command state %d\n",
+		    sc->name, cmd->state);
+		ub_state_done(sc, cmd, -EINVAL);
+		return;
+	}
+	return;
+
+Bad_End: /* Little Excel is dead */
+	ub_state_done(sc, cmd, -EIO);
+}
+
+/*
+ * Factorization helper for the command state machine:
+ * Initiate a data segment transfer.
+ */
+static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+	struct scatterlist *sg = &cmd->sgv[cmd->current_sg];
+	int pipe;
+	int rc;
+
+	UB_INIT_COMPLETION(sc->work_done);
+
+	if (cmd->dir == UB_DIR_READ)
+		pipe = sc->recv_bulk_pipe;
+	else
+		pipe = sc->send_bulk_pipe;
+	sc->last_pipe = pipe;
+	usb_fill_bulk_urb(&sc->work_urb, sc->dev, pipe, sg_virt(sg),
+	    sg->length, ub_urb_complete, sc);
+
+	if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
+		/* XXX Clear stalls */
+		ub_complete(&sc->work_done);
+		ub_state_done(sc, cmd, rc);
+		return;
+	}
+
+	if (cmd->timeo)
+		sc->work_timer.expires = jiffies + cmd->timeo;
+	else
+		sc->work_timer.expires = jiffies + UB_DATA_TIMEOUT;
+	add_timer(&sc->work_timer);
+
+	cmd->state = UB_CMDST_DATA;
+}
+
+/*
+ * Factorization helper for the command state machine:
+ * Finish the command.
+ */
+static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc)
+{
+
+	cmd->error = rc;
+	cmd->state = UB_CMDST_DONE;
+	ub_cmdq_pop(sc);
+	(*cmd->done)(sc, cmd);
+}
+
+/*
+ * Factorization helper for the command state machine:
+ * Submit a CSW read.
+ */
+static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+	int rc;
+
+	UB_INIT_COMPLETION(sc->work_done);
+
+	sc->last_pipe = sc->recv_bulk_pipe;
+	usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->recv_bulk_pipe,
+	    &sc->work_bcs, US_BULK_CS_WRAP_LEN, ub_urb_complete, sc);
+
+	if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
+		/* XXX Clear stalls */
+		ub_complete(&sc->work_done);
+		ub_state_done(sc, cmd, rc);
+		return -1;
+	}
+
+	if (cmd->timeo)
+		sc->work_timer.expires = jiffies + cmd->timeo;
+	else
+		sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT;
+	add_timer(&sc->work_timer);
+	return 0;
+}
+
+/*
+ * Factorization helper for the command state machine:
+ * Submit a CSW read and go to STAT state.
+ */
+static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+
+	if (__ub_state_stat(sc, cmd) != 0)
+		return;
+
+	cmd->stat_count = 0;
+	cmd->state = UB_CMDST_STAT;
+}
+
+/*
+ * Factorization helper for the command state machine:
+ * Submit a CSW read and go to STAT state with counter (along [C] path).
+ */
+static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+
+	if (++cmd->stat_count >= 4) {
+		ub_state_sense(sc, cmd);
+		return;
+	}
+
+	if (__ub_state_stat(sc, cmd) != 0)
+		return;
+
+	cmd->state = UB_CMDST_STAT;
+}
+
+/*
+ * Factorization helper for the command state machine:
+ * Submit a REQUEST SENSE and go to SENSE state.
+ */
+static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+	struct ub_scsi_cmd *scmd;
+	struct scatterlist *sg;
+	int rc;
+
+	if (cmd->cdb[0] == REQUEST_SENSE) {
+		rc = -EPIPE;
+		goto error;
+	}
+
+	scmd = &sc->top_rqs_cmd;
+	memset(scmd, 0, sizeof(struct ub_scsi_cmd));
+	scmd->cdb[0] = REQUEST_SENSE;
+	scmd->cdb[4] = UB_SENSE_SIZE;
+	scmd->cdb_len = 6;
+	scmd->dir = UB_DIR_READ;
+	scmd->state = UB_CMDST_INIT;
+	scmd->nsg = 1;
+	sg = &scmd->sgv[0];
+	sg_init_table(sg, UB_MAX_REQ_SG);
+	sg_set_page(sg, virt_to_page(sc->top_sense), UB_SENSE_SIZE,
+			(unsigned long)sc->top_sense & (PAGE_SIZE-1));
+	scmd->len = UB_SENSE_SIZE;
+	scmd->lun = cmd->lun;
+	scmd->done = ub_top_sense_done;
+	scmd->back = cmd;
+
+	scmd->tag = sc->tagcnt++;
+
+	cmd->state = UB_CMDST_SENSE;
+
+	ub_cmdq_insert(sc, scmd);
+	return;
+
+error:
+	ub_state_done(sc, cmd, rc);
+}
+
+/*
+ * A helper for the command's state machine:
+ * Submit a stall clear.
+ */
+static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
+    int stalled_pipe)
+{
+	int endp;
+	struct usb_ctrlrequest *cr;
+	int rc;
+
+	endp = usb_pipeendpoint(stalled_pipe);
+	if (usb_pipein (stalled_pipe))
+		endp |= USB_DIR_IN;
+
+	cr = &sc->work_cr;
+	cr->bRequestType = USB_RECIP_ENDPOINT;
+	cr->bRequest = USB_REQ_CLEAR_FEATURE;
+	cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
+	cr->wIndex = cpu_to_le16(endp);
+	cr->wLength = cpu_to_le16(0);
+
+	UB_INIT_COMPLETION(sc->work_done);
+
+	usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
+	    (unsigned char*) cr, NULL, 0, ub_urb_complete, sc);
+
+	if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
+		ub_complete(&sc->work_done);
+		return rc;
+	}
+
+	sc->work_timer.expires = jiffies + UB_CTRL_TIMEOUT;
+	add_timer(&sc->work_timer);
+	return 0;
+}
+
+/*
+ */
+static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
+{
+	unsigned char *sense = sc->top_sense;
+	struct ub_scsi_cmd *cmd;
+
+	/*
+	 * Find the command which triggered the unit attention or a check,
+	 * save the sense into it, and advance its state machine.
+	 */
+	if ((cmd = ub_cmdq_peek(sc)) == NULL) {
+		printk(KERN_WARNING "%s: sense done while idle\n", sc->name);
+		return;
+	}
+	if (cmd != scmd->back) {
+		printk(KERN_WARNING "%s: "
+		    "sense done for wrong command 0x%x\n",
+		    sc->name, cmd->tag);
+		return;
+	}
+	if (cmd->state != UB_CMDST_SENSE) {
+		printk(KERN_WARNING "%s: sense done with bad cmd state %d\n",
+		    sc->name, cmd->state);
+		return;
+	}
+
+	/*
+	 * Ignoring scmd->act_len, because the buffer was pre-zeroed.
+	 */
+	cmd->key = sense[2] & 0x0F;
+	cmd->asc = sense[12];
+	cmd->ascq = sense[13];
+
+	ub_scsi_urb_compl(sc, cmd);
+}
+
+/*
+ * Reset management
+ */
+
+static void ub_reset_enter(struct ub_dev *sc, int try)
+{
+
+	if (sc->reset) {
+		/* This happens often on multi-LUN devices. */
+		return;
+	}
+	sc->reset = try + 1;
+
+#if 0 /* Not needed because the disconnect waits for us. */
+	unsigned long flags;
+	spin_lock_irqsave(&ub_lock, flags);
+	sc->openc++;
+	spin_unlock_irqrestore(&ub_lock, flags);
+#endif
+
+#if 0 /* We let them stop themselves. */
+	struct ub_lun *lun;
+	list_for_each_entry(lun, &sc->luns, link) {
+		blk_stop_queue(lun->disk->queue);
+	}
+#endif
+
+	schedule_work(&sc->reset_work);
+}
+
+static void ub_reset_task(struct work_struct *work)
+{
+	struct ub_dev *sc = container_of(work, struct ub_dev, reset_work);
+	unsigned long flags;
+	struct ub_lun *lun;
+	int rc;
+
+	if (!sc->reset) {
+		printk(KERN_WARNING "%s: Running reset unrequested\n",
+		    sc->name);
+		return;
+	}
+
+	if (atomic_read(&sc->poison)) {
+		;
+	} else if ((sc->reset & 1) == 0) {
+		ub_sync_reset(sc);
+		msleep(700);	/* usb-storage sleeps 6s (!) */
+		ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
+		ub_probe_clear_stall(sc, sc->send_bulk_pipe);
+	} else if (sc->dev->actconfig->desc.bNumInterfaces != 1) {
+		;
+	} else {
+		rc = usb_lock_device_for_reset(sc->dev, sc->intf);
+		if (rc < 0) {
+			printk(KERN_NOTICE
+			    "%s: usb_lock_device_for_reset failed (%d)\n",
+			    sc->name, rc);
+		} else {
+			rc = usb_reset_device(sc->dev);
+			if (rc < 0) {
+				printk(KERN_NOTICE "%s: "
+				    "usb_lock_device_for_reset failed (%d)\n",
+				    sc->name, rc);
+			}
+			usb_unlock_device(sc->dev);
+		}
+	}
+
+	/*
+	 * In theory, no commands can be running while reset is active,
+	 * so nobody can ask for another reset, and so we do not need any
+	 * queues of resets or anything. We do need a spinlock though,
+	 * to interact with block layer.
+	 */
+	spin_lock_irqsave(sc->lock, flags);
+	sc->reset = 0;
+	tasklet_schedule(&sc->tasklet);
+	list_for_each_entry(lun, &sc->luns, link) {
+		blk_start_queue(lun->disk->queue);
+	}
+	wake_up(&sc->reset_wait);
+	spin_unlock_irqrestore(sc->lock, flags);
+}
+
+/*
+ * XXX Reset brackets are too much hassle to implement, so just stub them
+ * in order to prevent forced unbinding (which deadlocks solid when our
+ * ->disconnect method waits for the reset to complete and this kills keventd).
+ *
+ * XXX Tell Alan to move usb_unlock_device inside of usb_reset_device,
+ * or else the post_reset is invoked, and restats I/O on a locked device.
+ */
+static int ub_pre_reset(struct usb_interface *iface) {
+	return 0;
+}
+
+static int ub_post_reset(struct usb_interface *iface) {
+	return 0;
+}
+
+/*
+ * This is called from a process context.
+ */
+static void ub_revalidate(struct ub_dev *sc, struct ub_lun *lun)
+{
+
+	lun->readonly = 0;	/* XXX Query this from the device */
+
+	lun->capacity.nsec = 0;
+	lun->capacity.bsize = 512;
+	lun->capacity.bshift = 0;
+
+	if (ub_sync_tur(sc, lun) != 0)
+		return;			/* Not ready */
+	lun->changed = 0;
+
+	if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
+		/*
+		 * The retry here means something is wrong, either with the
+		 * device, with the transport, or with our code.
+		 * We keep this because sd.c has retries for capacity.
+		 */
+		if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
+			lun->capacity.nsec = 0;
+			lun->capacity.bsize = 512;
+			lun->capacity.bshift = 0;
+		}
+	}
+}
+
+/*
+ * The open funcion.
+ * This is mostly needed to keep refcounting, but also to support
+ * media checks on removable media drives.
+ */
+static int ub_bd_open(struct block_device *bdev, fmode_t mode)
+{
+	struct ub_lun *lun = bdev->bd_disk->private_data;
+	struct ub_dev *sc = lun->udev;
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(&ub_lock, flags);
+	if (atomic_read(&sc->poison)) {
+		spin_unlock_irqrestore(&ub_lock, flags);
+		return -ENXIO;
+	}
+	sc->openc++;
+	spin_unlock_irqrestore(&ub_lock, flags);
+
+	if (lun->removable || lun->readonly)
+		check_disk_change(bdev);
+
+	/*
+	 * The sd.c considers ->media_present and ->changed not equivalent,
+	 * under some pretty murky conditions (a failure of READ CAPACITY).
+	 * We may need it one day.
+	 */
+	if (lun->removable && lun->changed && !(mode & FMODE_NDELAY)) {
+		rc = -ENOMEDIUM;
+		goto err_open;
+	}
+
+	if (lun->readonly && (mode & FMODE_WRITE)) {
+		rc = -EROFS;
+		goto err_open;
+	}
+
+	return 0;
+
+err_open:
+	ub_put(sc);
+	return rc;
+}
+
+static int ub_bd_unlocked_open(struct block_device *bdev, fmode_t mode)
+{
+	int ret;
+
+	mutex_lock(&ub_mutex);
+	ret = ub_bd_open(bdev, mode);
+	mutex_unlock(&ub_mutex);
+
+	return ret;
+}
+
+
+/*
+ */
+static int ub_bd_release(struct gendisk *disk, fmode_t mode)
+{
+	struct ub_lun *lun = disk->private_data;
+	struct ub_dev *sc = lun->udev;
+
+	mutex_lock(&ub_mutex);
+	ub_put(sc);
+	mutex_unlock(&ub_mutex);
+
+	return 0;
+}
+
+/*
+ * The ioctl interface.
+ */
+static int ub_bd_ioctl(struct block_device *bdev, fmode_t mode,
+    unsigned int cmd, unsigned long arg)
+{
+	void __user *usermem = (void __user *) arg;
+	int ret;
+
+	mutex_lock(&ub_mutex);
+	ret = scsi_cmd_blk_ioctl(bdev, mode, cmd, usermem);
+	mutex_unlock(&ub_mutex);
+
+	return ret;
+}
+
+/*
+ * This is called by check_disk_change if we reported a media change.
+ * The main onjective here is to discover the features of the media such as
+ * the capacity, read-only status, etc. USB storage generally does not
+ * need to be spun up, but if we needed it, this would be the place.
+ *
+ * This call can sleep.
+ *
+ * The return code is not used.
+ */
+static int ub_bd_revalidate(struct gendisk *disk)
+{
+	struct ub_lun *lun = disk->private_data;
+
+	ub_revalidate(lun->udev, lun);
+
+	/* XXX Support sector size switching like in sr.c */
+	blk_queue_logical_block_size(disk->queue, lun->capacity.bsize);
+	set_capacity(disk, lun->capacity.nsec);
+	// set_disk_ro(sdkp->disk, lun->readonly);
+
+	return 0;
+}
+
+/*
+ * The check is called by the block layer to verify if the media
+ * is still available. It is supposed to be harmless, lightweight and
+ * non-intrusive in case the media was not changed.
+ *
+ * This call can sleep.
+ *
+ * The return code is bool!
+ */
+static unsigned int ub_bd_check_events(struct gendisk *disk,
+				       unsigned int clearing)
+{
+	struct ub_lun *lun = disk->private_data;
+
+	if (!lun->removable)
+		return 0;
+
+	/*
+	 * We clean checks always after every command, so this is not
+	 * as dangerous as it looks. If the TEST_UNIT_READY fails here,
+	 * the device is actually not ready with operator or software
+	 * intervention required. One dangerous item might be a drive which
+	 * spins itself down, and come the time to write dirty pages, this
+	 * will fail, then block layer discards the data. Since we never
+	 * spin drives up, such devices simply cannot be used with ub anyway.
+	 */
+	if (ub_sync_tur(lun->udev, lun) != 0) {
+		lun->changed = 1;
+		return DISK_EVENT_MEDIA_CHANGE;
+	}
+
+	return lun->changed ? DISK_EVENT_MEDIA_CHANGE : 0;
+}
+
+static const struct block_device_operations ub_bd_fops = {
+	.owner		= THIS_MODULE,
+	.open		= ub_bd_unlocked_open,
+	.release	= ub_bd_release,
+	.ioctl		= ub_bd_ioctl,
+	.check_events	= ub_bd_check_events,
+	.revalidate_disk = ub_bd_revalidate,
+};
+
+/*
+ * Common ->done routine for commands executed synchronously.
+ */
+static void ub_probe_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+	struct completion *cop = cmd->back;
+	complete(cop);
+}
+
+/*
+ * Test if the device has a check condition on it, synchronously.
+ */
+static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun)
+{
+	struct ub_scsi_cmd *cmd;
+	enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) };
+	unsigned long flags;
+	struct completion compl;
+	int rc;
+
+	init_completion(&compl);
+
+	rc = -ENOMEM;
+	if ((cmd = kzalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
+		goto err_alloc;
+
+	cmd->cdb[0] = TEST_UNIT_READY;
+	cmd->cdb_len = 6;
+	cmd->dir = UB_DIR_NONE;
+	cmd->state = UB_CMDST_INIT;
+	cmd->lun = lun;			/* This may be NULL, but that's ok */
+	cmd->done = ub_probe_done;
+	cmd->back = &compl;
+
+	spin_lock_irqsave(sc->lock, flags);
+	cmd->tag = sc->tagcnt++;
+
+	rc = ub_submit_scsi(sc, cmd);
+	spin_unlock_irqrestore(sc->lock, flags);
+
+	if (rc != 0)
+		goto err_submit;
+
+	wait_for_completion(&compl);
+
+	rc = cmd->error;
+
+	if (rc == -EIO && cmd->key != 0)	/* Retries for benh's key */
+		rc = cmd->key;
+
+err_submit:
+	kfree(cmd);
+err_alloc:
+	return rc;
+}
+
+/*
+ * Read the SCSI capacity synchronously (for probing).
+ */
+static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_capacity *ret)
+{
+	struct ub_scsi_cmd *cmd;
+	struct scatterlist *sg;
+	char *p;
+	enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) + 8 };
+	unsigned long flags;
+	unsigned int bsize, shift;
+	unsigned long nsec;
+	struct completion compl;
+	int rc;
+
+	init_completion(&compl);
+
+	rc = -ENOMEM;
+	if ((cmd = kzalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
+		goto err_alloc;
+	p = (char *)cmd + sizeof(struct ub_scsi_cmd);
+
+	cmd->cdb[0] = 0x25;
+	cmd->cdb_len = 10;
+	cmd->dir = UB_DIR_READ;
+	cmd->state = UB_CMDST_INIT;
+	cmd->nsg = 1;
+	sg = &cmd->sgv[0];
+	sg_init_table(sg, UB_MAX_REQ_SG);
+	sg_set_page(sg, virt_to_page(p), 8, (unsigned long)p & (PAGE_SIZE-1));
+	cmd->len = 8;
+	cmd->lun = lun;
+	cmd->done = ub_probe_done;
+	cmd->back = &compl;
+
+	spin_lock_irqsave(sc->lock, flags);
+	cmd->tag = sc->tagcnt++;
+
+	rc = ub_submit_scsi(sc, cmd);
+	spin_unlock_irqrestore(sc->lock, flags);
+
+	if (rc != 0)
+		goto err_submit;
+
+	wait_for_completion(&compl);
+
+	if (cmd->error != 0) {
+		rc = -EIO;
+		goto err_read;
+	}
+	if (cmd->act_len != 8) {
+		rc = -EIO;
+		goto err_read;
+	}
+
+	/* sd.c special-cases sector size of 0 to mean 512. Needed? Safe? */
+	nsec = be32_to_cpu(*(__be32 *)p) + 1;
+	bsize = be32_to_cpu(*(__be32 *)(p + 4));
+	switch (bsize) {
+	case 512:	shift = 0;	break;
+	case 1024:	shift = 1;	break;
+	case 2048:	shift = 2;	break;
+	case 4096:	shift = 3;	break;
+	default:
+		rc = -EDOM;
+		goto err_inv_bsize;
+	}
+
+	ret->bsize = bsize;
+	ret->bshift = shift;
+	ret->nsec = nsec << shift;
+	rc = 0;
+
+err_inv_bsize:
+err_read:
+err_submit:
+	kfree(cmd);
+err_alloc:
+	return rc;
+}
+
+/*
+ */
+static void ub_probe_urb_complete(struct urb *urb)
+{
+	struct completion *cop = urb->context;
+	complete(cop);
+}
+
+static void ub_probe_timeout(unsigned long arg)
+{
+	struct completion *cop = (struct completion *) arg;
+	complete(cop);
+}
+
+/*
+ * Reset with a Bulk reset.
+ */
+static int ub_sync_reset(struct ub_dev *sc)
+{
+	int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
+	struct usb_ctrlrequest *cr;
+	struct completion compl;
+	struct timer_list timer;
+	int rc;
+
+	init_completion(&compl);
+
+	cr = &sc->work_cr;
+	cr->bRequestType = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
+	cr->bRequest = US_BULK_RESET_REQUEST;
+	cr->wValue = cpu_to_le16(0);
+	cr->wIndex = cpu_to_le16(ifnum);
+	cr->wLength = cpu_to_le16(0);
+
+	usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
+	    (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
+
+	if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
+		printk(KERN_WARNING
+		     "%s: Unable to submit a bulk reset (%d)\n", sc->name, rc);
+		return rc;
+	}
+
+	init_timer(&timer);
+	timer.function = ub_probe_timeout;
+	timer.data = (unsigned long) &compl;
+	timer.expires = jiffies + UB_CTRL_TIMEOUT;
+	add_timer(&timer);
+
+	wait_for_completion(&compl);
+
+	del_timer_sync(&timer);
+	usb_kill_urb(&sc->work_urb);
+
+	return sc->work_urb.status;
+}
+
+/*
+ * Get number of LUNs by the way of Bulk GetMaxLUN command.
+ */
+static int ub_sync_getmaxlun(struct ub_dev *sc)
+{
+	int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
+	unsigned char *p;
+	enum { ALLOC_SIZE = 1 };
+	struct usb_ctrlrequest *cr;
+	struct completion compl;
+	struct timer_list timer;
+	int nluns;
+	int rc;
+
+	init_completion(&compl);
+
+	rc = -ENOMEM;
+	if ((p = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
+		goto err_alloc;
+	*p = 55;
+
+	cr = &sc->work_cr;
+	cr->bRequestType = USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
+	cr->bRequest = US_BULK_GET_MAX_LUN;
+	cr->wValue = cpu_to_le16(0);
+	cr->wIndex = cpu_to_le16(ifnum);
+	cr->wLength = cpu_to_le16(1);
+
+	usb_fill_control_urb(&sc->work_urb, sc->dev, sc->recv_ctrl_pipe,
+	    (unsigned char*) cr, p, 1, ub_probe_urb_complete, &compl);
+
+	if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0)
+		goto err_submit;
+
+	init_timer(&timer);
+	timer.function = ub_probe_timeout;
+	timer.data = (unsigned long) &compl;
+	timer.expires = jiffies + UB_CTRL_TIMEOUT;
+	add_timer(&timer);
+
+	wait_for_completion(&compl);
+
+	del_timer_sync(&timer);
+	usb_kill_urb(&sc->work_urb);
+
+	if ((rc = sc->work_urb.status) < 0)
+		goto err_io;
+
+	if (sc->work_urb.actual_length != 1) {
+		nluns = 0;
+	} else {
+		if ((nluns = *p) == 55) {
+			nluns = 0;
+		} else {
+  			/* GetMaxLUN returns the maximum LUN number */
+			nluns += 1;
+			if (nluns > UB_MAX_LUNS)
+				nluns = UB_MAX_LUNS;
+		}
+	}
+
+	kfree(p);
+	return nluns;
+
+err_io:
+err_submit:
+	kfree(p);
+err_alloc:
+	return rc;
+}
+
+/*
+ * Clear initial stalls.
+ */
+static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe)
+{
+	int endp;
+	struct usb_ctrlrequest *cr;
+	struct completion compl;
+	struct timer_list timer;
+	int rc;
+
+	init_completion(&compl);
+
+	endp = usb_pipeendpoint(stalled_pipe);
+	if (usb_pipein (stalled_pipe))
+		endp |= USB_DIR_IN;
+
+	cr = &sc->work_cr;
+	cr->bRequestType = USB_RECIP_ENDPOINT;
+	cr->bRequest = USB_REQ_CLEAR_FEATURE;
+	cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
+	cr->wIndex = cpu_to_le16(endp);
+	cr->wLength = cpu_to_le16(0);
+
+	usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
+	    (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
+
+	if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
+		printk(KERN_WARNING
+		     "%s: Unable to submit a probe clear (%d)\n", sc->name, rc);
+		return rc;
+	}
+
+	init_timer(&timer);
+	timer.function = ub_probe_timeout;
+	timer.data = (unsigned long) &compl;
+	timer.expires = jiffies + UB_CTRL_TIMEOUT;
+	add_timer(&timer);
+
+	wait_for_completion(&compl);
+
+	del_timer_sync(&timer);
+	usb_kill_urb(&sc->work_urb);
+
+	usb_reset_endpoint(sc->dev, endp);
+
+	return 0;
+}
+
+/*
+ * Get the pipe settings.
+ */
+static int ub_get_pipes(struct ub_dev *sc, struct usb_device *dev,
+    struct usb_interface *intf)
+{
+	struct usb_host_interface *altsetting = intf->cur_altsetting;
+	struct usb_endpoint_descriptor *ep_in = NULL;
+	struct usb_endpoint_descriptor *ep_out = NULL;
+	struct usb_endpoint_descriptor *ep;
+	int i;
+
+	/*
+	 * Find the endpoints we need.
+	 * We are expecting a minimum of 2 endpoints - in and out (bulk).
+	 * We will ignore any others.
+	 */
+	for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
+		ep = &altsetting->endpoint[i].desc;
+
+		/* Is it a BULK endpoint? */
+		if (usb_endpoint_xfer_bulk(ep)) {
+			/* BULK in or out? */
+			if (usb_endpoint_dir_in(ep)) {
+				if (ep_in == NULL)
+					ep_in = ep;
+			} else {
+				if (ep_out == NULL)
+					ep_out = ep;
+			}
+		}
+	}
+
+	if (ep_in == NULL || ep_out == NULL) {
+		printk(KERN_NOTICE "%s: failed endpoint check\n", sc->name);
+		return -ENODEV;
+	}
+
+	/* Calculate and store the pipe values */
+	sc->send_ctrl_pipe = usb_sndctrlpipe(dev, 0);
+	sc->recv_ctrl_pipe = usb_rcvctrlpipe(dev, 0);
+	sc->send_bulk_pipe = usb_sndbulkpipe(dev,
+		usb_endpoint_num(ep_out));
+	sc->recv_bulk_pipe = usb_rcvbulkpipe(dev, 
+		usb_endpoint_num(ep_in));
+
+	return 0;
+}
+
+/*
+ * Probing is done in the process context, which allows us to cheat
+ * and not to build a state machine for the discovery.
+ */
+static int ub_probe(struct usb_interface *intf,
+    const struct usb_device_id *dev_id)
+{
+	struct ub_dev *sc;
+	int nluns;
+	int rc;
+	int i;
+
+	if (usb_usual_check_type(dev_id, USB_US_TYPE_UB))
+		return -ENXIO;
+
+	rc = -ENOMEM;
+	if ((sc = kzalloc(sizeof(struct ub_dev), GFP_KERNEL)) == NULL)
+		goto err_core;
+	sc->lock = ub_next_lock();
+	INIT_LIST_HEAD(&sc->luns);
+	usb_init_urb(&sc->work_urb);
+	tasklet_init(&sc->tasklet, ub_scsi_action, (unsigned long)sc);
+	atomic_set(&sc->poison, 0);
+	INIT_WORK(&sc->reset_work, ub_reset_task);
+	init_waitqueue_head(&sc->reset_wait);
+
+	init_timer(&sc->work_timer);
+	sc->work_timer.data = (unsigned long) sc;
+	sc->work_timer.function = ub_urb_timeout;
+
+	ub_init_completion(&sc->work_done);
+	sc->work_done.done = 1;		/* A little yuk, but oh well... */
+
+	sc->dev = interface_to_usbdev(intf);
+	sc->intf = intf;
+	// sc->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
+	usb_set_intfdata(intf, sc);
+	usb_get_dev(sc->dev);
+	/*
+	 * Since we give the interface struct to the block level through
+	 * disk->driverfs_dev, we have to pin it. Otherwise, block_uevent
+	 * oopses on close after a disconnect (kernels 2.6.16 and up).
+	 */
+	usb_get_intf(sc->intf);
+
+	snprintf(sc->name, 12, DRV_NAME "(%d.%d)",
+	    sc->dev->bus->busnum, sc->dev->devnum);
+
+	/* XXX Verify that we can handle the device (from descriptors) */
+
+	if (ub_get_pipes(sc, sc->dev, intf) != 0)
+		goto err_dev_desc;
+
+	/*
+	 * At this point, all USB initialization is done, do upper layer.
+	 * We really hate halfway initialized structures, so from the
+	 * invariants perspective, this ub_dev is fully constructed at
+	 * this point.
+	 */
+
+	/*
+	 * This is needed to clear toggles. It is a problem only if we do
+	 * `rmmod ub && modprobe ub` without disconnects, but we like that.
+	 */
+#if 0 /* iPod Mini fails if we do this (big white iPod works) */
+	ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
+	ub_probe_clear_stall(sc, sc->send_bulk_pipe);
+#endif
+
+	/*
+	 * The way this is used by the startup code is a little specific.
+	 * A SCSI check causes a USB stall. Our common case code sees it
+	 * and clears the check, after which the device is ready for use.
+	 * But if a check was not present, any command other than
+	 * TEST_UNIT_READY ends with a lockup (including REQUEST_SENSE).
+	 *
+	 * If we neglect to clear the SCSI check, the first real command fails
+	 * (which is the capacity readout). We clear that and retry, but why
+	 * causing spurious retries for no reason.
+	 *
+	 * Revalidation may start with its own TEST_UNIT_READY, but that one
+	 * has to succeed, so we clear checks with an additional one here.
+	 * In any case it's not our business how revaliadation is implemented.
+	 */
+	for (i = 0; i < 3; i++) {  /* Retries for the schwag key from KS'04 */
+		if ((rc = ub_sync_tur(sc, NULL)) <= 0) break;
+		if (rc != 0x6) break;
+		msleep(10);
+	}
+
+	nluns = 1;
+	for (i = 0; i < 3; i++) {
+		if ((rc = ub_sync_getmaxlun(sc)) < 0)
+			break;
+		if (rc != 0) {
+			nluns = rc;
+			break;
+		}
+		msleep(100);
+	}
+
+	for (i = 0; i < nluns; i++) {
+		ub_probe_lun(sc, i);
+	}
+	return 0;
+
+err_dev_desc:
+	usb_set_intfdata(intf, NULL);
+	usb_put_intf(sc->intf);
+	usb_put_dev(sc->dev);
+	kfree(sc);
+err_core:
+	return rc;
+}
+
+static int ub_probe_lun(struct ub_dev *sc, int lnum)
+{
+	struct ub_lun *lun;
+	struct request_queue *q;
+	struct gendisk *disk;
+	int rc;
+
+	rc = -ENOMEM;
+	if ((lun = kzalloc(sizeof(struct ub_lun), GFP_KERNEL)) == NULL)
+		goto err_alloc;
+	lun->num = lnum;
+
+	rc = -ENOSR;
+	if ((lun->id = ub_id_get()) == -1)
+		goto err_id;
+
+	lun->udev = sc;
+
+	snprintf(lun->name, 16, DRV_NAME "%c(%d.%d.%d)",
+	    lun->id + 'a', sc->dev->bus->busnum, sc->dev->devnum, lun->num);
+
+	lun->removable = 1;		/* XXX Query this from the device */
+	lun->changed = 1;		/* ub_revalidate clears only */
+	ub_revalidate(sc, lun);
+
+	rc = -ENOMEM;
+	if ((disk = alloc_disk(UB_PARTS_PER_LUN)) == NULL)
+		goto err_diskalloc;
+
+	sprintf(disk->disk_name, DRV_NAME "%c", lun->id + 'a');
+	disk->major = UB_MAJOR;
+	disk->first_minor = lun->id * UB_PARTS_PER_LUN;
+	disk->fops = &ub_bd_fops;
+	disk->private_data = lun;
+	disk->driverfs_dev = &sc->intf->dev;
+
+	rc = -ENOMEM;
+	if ((q = blk_init_queue(ub_request_fn, sc->lock)) == NULL)
+		goto err_blkqinit;
+
+	disk->queue = q;
+
+	blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
+	blk_queue_max_segments(q, UB_MAX_REQ_SG);
+	blk_queue_segment_boundary(q, 0xffffffff);	/* Dubious. */
+	blk_queue_max_hw_sectors(q, UB_MAX_SECTORS);
+	blk_queue_logical_block_size(q, lun->capacity.bsize);
+
+	lun->disk = disk;
+	q->queuedata = lun;
+	list_add(&lun->link, &sc->luns);
+
+	set_capacity(disk, lun->capacity.nsec);
+	if (lun->removable)
+		disk->flags |= GENHD_FL_REMOVABLE;
+
+	add_disk(disk);
+
+	return 0;
+
+err_blkqinit:
+	put_disk(disk);
+err_diskalloc:
+	ub_id_put(lun->id);
+err_id:
+	kfree(lun);
+err_alloc:
+	return rc;
+}
+
+static void ub_disconnect(struct usb_interface *intf)
+{
+	struct ub_dev *sc = usb_get_intfdata(intf);
+	struct ub_lun *lun;
+	unsigned long flags;
+
+	/*
+	 * Prevent ub_bd_release from pulling the rug from under us.
+	 * XXX This is starting to look like a kref.
+	 * XXX Why not to take this ref at probe time?
+	 */
+	spin_lock_irqsave(&ub_lock, flags);
+	sc->openc++;
+	spin_unlock_irqrestore(&ub_lock, flags);
+
+	/*
+	 * Fence stall clearings, operations triggered by unlinkings and so on.
+	 * We do not attempt to unlink any URBs, because we do not trust the
+	 * unlink paths in HC drivers. Also, we get -84 upon disconnect anyway.
+	 */
+	atomic_set(&sc->poison, 1);
+
+	/*
+	 * Wait for reset to end, if any.
+	 */
+	wait_event(sc->reset_wait, !sc->reset);
+
+	/*
+	 * Blow away queued commands.
+	 *
+	 * Actually, this never works, because before we get here
+	 * the HCD terminates outstanding URB(s). It causes our
+	 * SCSI command queue to advance, commands fail to submit,
+	 * and the whole queue drains. So, we just use this code to
+	 * print warnings.
+	 */
+	spin_lock_irqsave(sc->lock, flags);
+	{
+		struct ub_scsi_cmd *cmd;
+		int cnt = 0;
+		while ((cmd = ub_cmdq_peek(sc)) != NULL) {
+			cmd->error = -ENOTCONN;
+			cmd->state = UB_CMDST_DONE;
+			ub_cmdq_pop(sc);
+			(*cmd->done)(sc, cmd);
+			cnt++;
+		}
+		if (cnt != 0) {
+			printk(KERN_WARNING "%s: "
+			    "%d was queued after shutdown\n", sc->name, cnt);
+		}
+	}
+	spin_unlock_irqrestore(sc->lock, flags);
+
+	/*
+	 * Unregister the upper layer.
+	 */
+	list_for_each_entry(lun, &sc->luns, link) {
+		del_gendisk(lun->disk);
+		/*
+		 * I wish I could do:
+		 *    queue_flag_set(QUEUE_FLAG_DEAD, q);
+		 * As it is, we rely on our internal poisoning and let
+		 * the upper levels to spin furiously failing all the I/O.
+		 */
+	}
+
+	/*
+	 * Testing for -EINPROGRESS is always a bug, so we are bending
+	 * the rules a little.
+	 */
+	spin_lock_irqsave(sc->lock, flags);
+	if (sc->work_urb.status == -EINPROGRESS) {	/* janitors: ignore */
+		printk(KERN_WARNING "%s: "
+		    "URB is active after disconnect\n", sc->name);
+	}
+	spin_unlock_irqrestore(sc->lock, flags);
+
+	/*
+	 * There is virtually no chance that other CPU runs a timeout so long
+	 * after ub_urb_complete should have called del_timer, but only if HCD
+	 * didn't forget to deliver a callback on unlink.
+	 */
+	del_timer_sync(&sc->work_timer);
+
+	/*
+	 * At this point there must be no commands coming from anyone
+	 * and no URBs left in transit.
+	 */
+
+	ub_put(sc);
+}
+
+static struct usb_driver ub_driver = {
+	.name =		"ub",
+	.probe =	ub_probe,
+	.disconnect =	ub_disconnect,
+	.id_table =	ub_usb_ids,
+	.pre_reset =	ub_pre_reset,
+	.post_reset =	ub_post_reset,
+};
+
+static int __init ub_init(void)
+{
+	int rc;
+	int i;
+
+	pr_info("'Low Performance USB Block' driver is deprecated. "
+			"Please switch to usb-storage\n");
+	for (i = 0; i < UB_QLOCK_NUM; i++)
+		spin_lock_init(&ub_qlockv[i]);
+
+	if ((rc = register_blkdev(UB_MAJOR, DRV_NAME)) != 0)
+		goto err_regblkdev;
+
+	if ((rc = usb_register(&ub_driver)) != 0)
+		goto err_register;
+
+	usb_usual_set_present(USB_US_TYPE_UB);
+	return 0;
+
+err_register:
+	unregister_blkdev(UB_MAJOR, DRV_NAME);
+err_regblkdev:
+	return rc;
+}
+
+static void __exit ub_exit(void)
+{
+	usb_deregister(&ub_driver);
+
+	unregister_blkdev(UB_MAJOR, DRV_NAME);
+	usb_usual_clear_present(USB_US_TYPE_UB);
+}
+
+module_init(ub_init);
+module_exit(ub_exit);
+
+MODULE_LICENSE("GPL");