USB: g_mass_storage: most data moved to fsg_common

Most of the data from fsg_dev have been moved to fsg_common
structure.  The fsg_dev structure holds only endpoint dependent
data.  The fsg_common structure has a fsg pointer which points
to active fsg_dev structure -- endpoints are referenced via this
pointer.

This fixes the problem of several threads created when a single
instance of MSF is used in several USB configurations.

Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 648 insertions, 582 deletions

diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index 5eaf22db7fcc..a6cec37768a9 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -312,14 +312,26 @@ static const char fsg_string_interface[] = "Mass Storage";
 
 /*-------------------------------------------------------------------------*/
 
+struct fsg_dev;
+
 
 /* Data shared by all the FSG instances. */
 struct fsg_common {
         struct usb_gadget       *gadget;
+        struct fsg_dev          *fsg;
+        struct fsg_dev          *prev_fsg;
 
         /* filesem protects: backing files in use */
         struct rw_semaphore     filesem;
 
+        /* lock protects: state, all the req_busy's */
+        spinlock_t              lock;
+
+        struct usb_ep           *ep0;           /* Copy of gadget->ep0 */
+        struct usb_request      *ep0req;        /* Copy of cdev->req */
+        unsigned int            ep0_req_tag;
+        const char              *ep0req_name;
+
         struct fsg_buffhd       *next_buffhd_to_fill;
         struct fsg_buffhd       *next_buffhd_to_drain;
         struct fsg_buffhd       buffhds[FSG_NUM_BUFFERS];
@@ -332,10 +344,28 @@ struct fsg_common {
         struct fsg_lun          *luns;
         struct fsg_lun          *curlun;
 
+        unsigned int            bulk_out_maxpacket;
+        enum fsg_state          state;          /* For exception handling */
+        unsigned int            exception_req_tag;
+
+        u8                      config, new_config;
+        enum data_direction     data_dir;
+        u32                     data_size;
+        u32                     data_size_from_cmnd;
+        u32                     tag;
+        u32                     residue;
+        u32                     usb_amount_left;
+
         unsigned int            can_stall:1;
         unsigned int            free_storage_on_release:1;
+        unsigned int            phase_error:1;
+        unsigned int            short_packet_received:1;
+        unsigned int            bad_lun_okay:1;
+        unsigned int            running:1;
 
-        const char              *thread_name;
+        int                     thread_wakeup_needed;
+        struct completion       thread_notifier;
+        struct task_struct      *thread_task;
 
         /* Vendor (8 chars), product (16 chars), release (4
          * hexadecimal digits) and NUL byte */
@@ -367,52 +397,32 @@ struct fsg_config {
 
 struct fsg_dev {
         struct usb_function     function;
-        struct usb_composite_dev *cdev;
         struct usb_gadget       *gadget;        /* Copy of cdev->gadget */
         struct fsg_common       *common;
 
         u16                     interface_number;
 
-        /* lock protects: state, all the req_busy's */
-        spinlock_t              lock;
-
-        struct usb_ep           *ep0;           /* Copy of gadget->ep0 */
-        struct usb_request      *ep0req;        /* Copy of cdev->req */
-        unsigned int            ep0_req_tag;
-        const char              *ep0req_name;
-
-        unsigned int            bulk_out_maxpacket;
-        enum fsg_state          state;          /* For exception handling */
-        unsigned int            exception_req_tag;
-
-        u8                      config, new_config;
-
-        unsigned int            running:1;
         unsigned int            bulk_in_enabled:1;
         unsigned int            bulk_out_enabled:1;
-        unsigned int            phase_error:1;
-        unsigned int            short_packet_received:1;
-        unsigned int            bad_lun_okay:1;
-        unsigned int            can_stall:1;
 
         unsigned long           atomic_bitflags;
-#define REGISTERED              0
-#define IGNORE_BULK_OUT         1
+#define IGNORE_BULK_OUT         0
 
         struct usb_ep           *bulk_in;
         struct usb_ep           *bulk_out;
+};
 
-        int                     thread_wakeup_needed;
-        struct completion       thread_notifier;
-        struct task_struct      *thread_task;
 
-        enum data_direction     data_dir;
-        u32                     data_size;
-        u32                     data_size_from_cmnd;
-        u32                     tag;
-        u32                     residue;
-        u32                     usb_amount_left;
-};
+static inline int __fsg_is_set(struct fsg_common *common,
+                               const char *func, unsigned line)
+{
+        if (common->fsg)
+                return 1;
+        ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
+        return 0;
+}
+
+#define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
 
 
 static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
@@ -423,21 +433,21 @@ static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
 
 typedef void (*fsg_routine_t)(struct fsg_dev *);
 
-static int exception_in_progress(struct fsg_dev *fsg)
+static int exception_in_progress(struct fsg_common *common)
 {
-        return (fsg->state > FSG_STATE_IDLE);
+        return common->state > FSG_STATE_IDLE;
 }
 
 /* Make bulk-out requests be divisible by the maxpacket size */
-static void set_bulk_out_req_length(struct fsg_dev *fsg,
+static void set_bulk_out_req_length(struct fsg_common *common,
                 struct fsg_buffhd *bh, unsigned int length)
 {
         unsigned int    rem;
 
         bh->bulk_out_intended_length = length;
-        rem = length % fsg->bulk_out_maxpacket;
+        rem = length % common->bulk_out_maxpacket;
         if (rem > 0)
-                length += fsg->bulk_out_maxpacket - rem;
+                length += common->bulk_out_maxpacket - rem;
         bh->outreq->length = length;
 }
 
@@ -463,47 +473,46 @@ static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
 /* These routines may be called in process context or in_irq */
 
 /* Caller must hold fsg->lock */
-static void wakeup_thread(struct fsg_dev *fsg)
+static void wakeup_thread(struct fsg_common *common)
 {
         /* Tell the main thread that something has happened */
-        fsg->thread_wakeup_needed = 1;
-        if (fsg->thread_task)
-                wake_up_process(fsg->thread_task);
+        common->thread_wakeup_needed = 1;
+        if (common->thread_task)
+                wake_up_process(common->thread_task);
 }
 
 
-static void raise_exception(struct fsg_dev *fsg, enum fsg_state new_state)
+static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
 {
         unsigned long           flags;
 
         /* Do nothing if a higher-priority exception is already in progress.
          * If a lower-or-equal priority exception is in progress, preempt it
          * and notify the main thread by sending it a signal. */
-        spin_lock_irqsave(&fsg->lock, flags);
-        if (fsg->state <= new_state) {
-                fsg->exception_req_tag = fsg->ep0_req_tag;
-                fsg->state = new_state;
-                if (fsg->thread_task)
+        spin_lock_irqsave(&common->lock, flags);
+        if (common->state <= new_state) {
+                common->exception_req_tag = common->ep0_req_tag;
+                common->state = new_state;
+                if (common->thread_task)
                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
-                                        fsg->thread_task);
+                                      common->thread_task);
         }
-        spin_unlock_irqrestore(&fsg->lock, flags);
+        spin_unlock_irqrestore(&common->lock, flags);
 }
 
 
 /*-------------------------------------------------------------------------*/
 
-static int ep0_queue(struct fsg_dev *fsg)
+static int ep0_queue(struct fsg_common *common)
 {
         int     rc;
 
-        rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC);
-        fsg->ep0->driver_data = fsg;
+        rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
+        common->ep0->driver_data = common;
         if (rc != 0 && rc != -ESHUTDOWN) {
-
                 /* We can't do much more than wait for a reset */
-                WARNING(fsg, "error in submission: %s --> %d\n",
-                                fsg->ep0->name, rc);
+                WARNING(common, "error in submission: %s --> %d\n",
+                        common->ep0->name, rc);
         }
         return rc;
 }
@@ -515,32 +524,32 @@ static int ep0_queue(struct fsg_dev *fsg)
 
 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
 {
-        struct fsg_dev          *fsg = ep->driver_data;
+        struct fsg_common       *common = ep->driver_data;
         struct fsg_buffhd       *bh = req->context;
 
         if (req->status || req->actual != req->length)
-                DBG(fsg, "%s --> %d, %u/%u\n", __func__,
+                DBG(common, "%s --> %d, %u/%u\n", __func__,
                                 req->status, req->actual, req->length);
         if (req->status == -ECONNRESET)         /* Request was cancelled */
                 usb_ep_fifo_flush(ep);
 
         /* Hold the lock while we update the request and buffer states */
         smp_wmb();
-        spin_lock(&fsg->lock);
+        spin_lock(&common->lock);
         bh->inreq_busy = 0;
         bh->state = BUF_STATE_EMPTY;
-        wakeup_thread(fsg);
-        spin_unlock(&fsg->lock);
+        wakeup_thread(common);
+        spin_unlock(&common->lock);
 }
 
 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
 {
-        struct fsg_dev          *fsg = ep->driver_data;
+        struct fsg_common       *common = ep->driver_data;
         struct fsg_buffhd       *bh = req->context;
 
-        dump_msg(fsg, "bulk-out", req->buf, req->actual);
+        dump_msg(common, "bulk-out", req->buf, req->actual);
         if (req->status || req->actual != bh->bulk_out_intended_length)
-                DBG(fsg, "%s --> %d, %u/%u\n", __func__,
+                DBG(common, "%s --> %d, %u/%u\n", __func__,
                                 req->status, req->actual,
                                 bh->bulk_out_intended_length);
         if (req->status == -ECONNRESET)         /* Request was cancelled */
@@ -548,11 +557,11 @@ static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
 
         /* Hold the lock while we update the request and buffer states */
         smp_wmb();
-        spin_lock(&fsg->lock);
+        spin_lock(&common->lock);
         bh->outreq_busy = 0;
         bh->state = BUF_STATE_FULL;
-        wakeup_thread(fsg);
-        spin_unlock(&fsg->lock);
+        wakeup_thread(common);
+        spin_unlock(&common->lock);
 }
 
 
@@ -564,12 +573,12 @@ static int fsg_setup(struct usb_function *f,
                 const struct usb_ctrlrequest *ctrl)
 {
         struct fsg_dev          *fsg = fsg_from_func(f);
-        struct usb_request      *req = fsg->ep0req;
+        struct usb_request      *req = fsg->common->ep0req;
         u16                     w_index = le16_to_cpu(ctrl->wIndex);
         u16                     w_value = le16_to_cpu(ctrl->wValue);
         u16                     w_length = le16_to_cpu(ctrl->wLength);
 
-        if (!fsg->config)
+        if (!fsg->common->config)
                 return -EOPNOTSUPP;
 
         switch (ctrl->bRequest) {
@@ -584,7 +593,7 @@ static int fsg_setup(struct usb_function *f,
                 /* Raise an exception to stop the current operation
                  * and reinitialize our state. */
                 DBG(fsg, "bulk reset request\n");
-                raise_exception(fsg, FSG_STATE_RESET);
+                raise_exception(fsg->common, FSG_STATE_RESET);
                 return DELAYED_STATUS;
 
         case USB_BULK_GET_MAX_LUN_REQUEST:
@@ -622,10 +631,10 @@ static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
         if (ep == fsg->bulk_in)
                 dump_msg(fsg, "bulk-in", req->buf, req->length);
 
-        spin_lock_irq(&fsg->lock);
+        spin_lock_irq(&fsg->common->lock);
         *pbusy = 1;
         *state = BUF_STATE_BUSY;
-        spin_unlock_irq(&fsg->lock);
+        spin_unlock_irq(&fsg->common->lock);
         rc = usb_ep_queue(ep, req, GFP_KERNEL);
         if (rc != 0) {
                 *pbusy = 0;
@@ -642,8 +651,18 @@ static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
         }
 }
 
+#define START_TRANSFER_OR(common, ep_name, req, pbusy, state)           \
+        if (fsg_is_set(common))                                         \
+                start_transfer((common)->fsg, (common)->fsg->ep_name,   \
+                               req, pbusy, state);                      \
+        else
+
+#define START_TRANSFER(common, ep_name, req, pbusy, state)              \
+        START_TRANSFER_OR(common, ep_name, req, pbusy, state) (void)0
+
+
 
-static int sleep_thread(struct fsg_dev *fsg)
+static int sleep_thread(struct fsg_common *common)
 {
         int     rc = 0;
 
@@ -655,21 +674,21 @@ static int sleep_thread(struct fsg_dev *fsg)
                         rc = -EINTR;
                         break;
                 }
-                if (fsg->thread_wakeup_needed)
+                if (common->thread_wakeup_needed)
                         break;
                 schedule();
         }
         __set_current_state(TASK_RUNNING);
-        fsg->thread_wakeup_needed = 0;
+        common->thread_wakeup_needed = 0;
         return rc;
 }
 
 
 /*-------------------------------------------------------------------------*/
 
-static int do_read(struct fsg_dev *fsg)
+static int do_read(struct fsg_common *common)
 {
-        struct fsg_lun          *curlun = fsg->common->curlun;
+        struct fsg_lun          *curlun = common->curlun;
         u32                     lba;
         struct fsg_buffhd       *bh;
         int                     rc;
@@ -681,15 +700,15 @@ static int do_read(struct fsg_dev *fsg)
 
         /* Get the starting Logical Block Address and check that it's
          * not too big */
-        if (fsg->common->cmnd[0] == SC_READ_6)
-                lba = get_unaligned_be24(&fsg->common->cmnd[1]);
+        if (common->cmnd[0] == SC_READ_6)
+                lba = get_unaligned_be24(&common->cmnd[1]);
         else {
-                lba = get_unaligned_be32(&fsg->common->cmnd[2]);
+                lba = get_unaligned_be32(&common->cmnd[2]);
 
                 /* We allow DPO (Disable Page Out = don't save data in the
                  * cache) and FUA (Force Unit Access = don't read from the
                  * cache), but we don't implement them. */
-                if ((fsg->common->cmnd[1] & ~0x18) != 0) {
+                if ((common->cmnd[1] & ~0x18) != 0) {
                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
                         return -EINVAL;
                 }
@@ -701,7 +720,7 @@ static int do_read(struct fsg_dev *fsg)
         file_offset = ((loff_t) lba) << 9;
 
         /* Carry out the file reads */
-        amount_left = fsg->data_size_from_cmnd;
+        amount_left = common->data_size_from_cmnd;
         if (unlikely(amount_left == 0))
                 return -EIO;            /* No default reply */
 
@@ -724,9 +743,9 @@ static int do_read(struct fsg_dev *fsg)
                                         partial_page);
 
                 /* Wait for the next buffer to become available */
-                bh = fsg->common->next_buffhd_to_fill;
+                bh = common->next_buffhd_to_fill;
                 while (bh->state != BUF_STATE_EMPTY) {
-                        rc = sleep_thread(fsg);
+                        rc = sleep_thread(common);
                         if (rc)
                                 return rc;
                 }
@@ -765,7 +784,7 @@ static int do_read(struct fsg_dev *fsg)
                 }
                 file_offset  += nread;
                 amount_left  -= nread;
-                fsg->residue -= nread;
+                common->residue -= nread;
                 bh->inreq->length = nread;
                 bh->state = BUF_STATE_FULL;
 
@@ -782,9 +801,12 @@ static int do_read(struct fsg_dev *fsg)
 
                 /* Send this buffer and go read some more */
                 bh->inreq->zero = 0;
-                start_transfer(fsg, fsg->bulk_in, bh->inreq,
-                                &bh->inreq_busy, &bh->state);
-                fsg->common->next_buffhd_to_fill = bh->next;
+                START_TRANSFER_OR(common, bulk_in, bh->inreq,
+                               &bh->inreq_busy, &bh->state)
+                        /* Don't know what to do if
+                         * common->fsg is NULL */
+                        return -EIO;
+                common->next_buffhd_to_fill = bh->next;
         }
 
         return -EIO;            /* No default reply */
@@ -793,9 +815,9 @@ static int do_read(struct fsg_dev *fsg)
 
 /*-------------------------------------------------------------------------*/
 
-static int do_write(struct fsg_dev *fsg)
+static int do_write(struct fsg_common *common)
 {
-        struct fsg_lun          *curlun = fsg->common->curlun;
+        struct fsg_lun          *curlun = common->curlun;
         u32                     lba;
         struct fsg_buffhd       *bh;
         int                     get_some_more;
@@ -816,20 +838,20 @@ static int do_write(struct fsg_dev *fsg)
 
         /* Get the starting Logical Block Address and check that it's
          * not too big */
-        if (fsg->common->cmnd[0] == SC_WRITE_6)
-                lba = get_unaligned_be24(&fsg->common->cmnd[1]);
+        if (common->cmnd[0] == SC_WRITE_6)
+                lba = get_unaligned_be24(&common->cmnd[1]);
         else {
-                lba = get_unaligned_be32(&fsg->common->cmnd[2]);
+                lba = get_unaligned_be32(&common->cmnd[2]);
 
                 /* We allow DPO (Disable Page Out = don't save data in the
                  * cache) and FUA (Force Unit Access = write directly to the
                  * medium).  We don't implement DPO; we implement FUA by
                  * performing synchronous output. */
-                if ((fsg->common->cmnd[1] & ~0x18) != 0) {
+                if (common->cmnd[1] & ~0x18) {
                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
                         return -EINVAL;
                 }
-                if (fsg->common->cmnd[1] & 0x08) {      /* FUA */
+                if (common->cmnd[1] & 0x08) {   /* FUA */
                         spin_lock(&curlun->filp->f_lock);
                         curlun->filp->f_flags |= O_SYNC;
                         spin_unlock(&curlun->filp->f_lock);
@@ -843,12 +865,13 @@ static int do_write(struct fsg_dev *fsg)
         /* Carry out the file writes */
         get_some_more = 1;
         file_offset = usb_offset = ((loff_t) lba) << 9;
-        amount_left_to_req = amount_left_to_write = fsg->data_size_from_cmnd;
+        amount_left_to_req = common->data_size_from_cmnd;
+        amount_left_to_write = common->data_size_from_cmnd;
 
         while (amount_left_to_write > 0) {
 
                 /* Queue a request for more data from the host */
-                bh = fsg->common->next_buffhd_to_fill;
+                bh = common->next_buffhd_to_fill;
                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
 
                         /* Figure out how much we want to get:
@@ -887,7 +910,7 @@ static int do_write(struct fsg_dev *fsg)
 
                         /* Get the next buffer */
                         usb_offset += amount;
-                        fsg->usb_amount_left -= amount;
+                        common->usb_amount_left -= amount;
                         amount_left_to_req -= amount;
                         if (amount_left_to_req == 0)
                                 get_some_more = 0;
@@ -897,19 +920,22 @@ static int do_write(struct fsg_dev *fsg)
                         bh->outreq->length = amount;
                         bh->bulk_out_intended_length = amount;
                         bh->outreq->short_not_ok = 1;
-                        start_transfer(fsg, fsg->bulk_out, bh->outreq,
-                                        &bh->outreq_busy, &bh->state);
-                        fsg->common->next_buffhd_to_fill = bh->next;
+                        START_TRANSFER_OR(common, bulk_out, bh->outreq,
+                                          &bh->outreq_busy, &bh->state)
+                                /* Don't know what to do if
+                                 * common->fsg is NULL */
+                                return -EIO;
+                        common->next_buffhd_to_fill = bh->next;
                         continue;
                 }
 
                 /* Write the received data to the backing file */
-                bh = fsg->common->next_buffhd_to_drain;
+                bh = common->next_buffhd_to_drain;
                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
                         break;                  /* We stopped early */
                 if (bh->state == BUF_STATE_FULL) {
                         smp_rmb();
-                        fsg->common->next_buffhd_to_drain = bh->next;
+                        common->next_buffhd_to_drain = bh->next;
                         bh->state = BUF_STATE_EMPTY;
 
                         /* Did something go wrong with the transfer? */
@@ -952,7 +978,7 @@ static int do_write(struct fsg_dev *fsg)
                         }
                         file_offset += nwritten;
                         amount_left_to_write -= nwritten;
-                        fsg->residue -= nwritten;
+                        common->residue -= nwritten;
 
                         /* If an error occurred, report it and its position */
                         if (nwritten < amount) {
@@ -964,14 +990,14 @@ static int do_write(struct fsg_dev *fsg)
 
                         /* Did the host decide to stop early? */
                         if (bh->outreq->actual != bh->outreq->length) {
-                                fsg->short_packet_received = 1;
+                                common->short_packet_received = 1;
                                 break;
                         }
                         continue;
                 }
 
                 /* Wait for something to happen */
-                rc = sleep_thread(fsg);
+                rc = sleep_thread(common);
                 if (rc)
                         return rc;
         }
@@ -982,9 +1008,9 @@ static int do_write(struct fsg_dev *fsg)
 
 /*-------------------------------------------------------------------------*/
 
-static int do_synchronize_cache(struct fsg_dev *fsg)
+static int do_synchronize_cache(struct fsg_common *common)
 {
-        struct fsg_lun  *curlun = fsg->common->curlun;
+        struct fsg_lun  *curlun = common->curlun;
         int             rc;
 
         /* We ignore the requested LBA and write out all file's
@@ -1008,12 +1034,12 @@ static void invalidate_sub(struct fsg_lun *curlun)
         VLDBG(curlun, "invalidate_inode_pages -> %ld\n", rc);
 }
 
-static int do_verify(struct fsg_dev *fsg)
+static int do_verify(struct fsg_common *common)
 {
-        struct fsg_lun          *curlun = fsg->common->curlun;
+        struct fsg_lun          *curlun = common->curlun;
         u32                     lba;
         u32                     verification_length;
-        struct fsg_buffhd       *bh = fsg->common->next_buffhd_to_fill;
+        struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
         loff_t                  file_offset, file_offset_tmp;
         u32                     amount_left;
         unsigned int            amount;
@@ -1021,7 +1047,7 @@ static int do_verify(struct fsg_dev *fsg)
 
         /* Get the starting Logical Block Address and check that it's
          * not too big */
-        lba = get_unaligned_be32(&fsg->common->cmnd[2]);
+        lba = get_unaligned_be32(&common->cmnd[2]);
         if (lba >= curlun->num_sectors) {
                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
                 return -EINVAL;
@@ -1029,12 +1055,12 @@ static int do_verify(struct fsg_dev *fsg)
 
         /* We allow DPO (Disable Page Out = don't save data in the
          * cache) but we don't implement it. */
-        if ((fsg->common->cmnd[1] & ~0x10) != 0) {
+        if (common->cmnd[1] & ~0x10) {
                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
                 return -EINVAL;
         }
 
-        verification_length = get_unaligned_be16(&fsg->common->cmnd[7]);
+        verification_length = get_unaligned_be16(&common->cmnd[7]);
         if (unlikely(verification_length == 0))
                 return -EIO;            /* No default reply */
 
@@ -1106,13 +1132,13 @@ static int do_verify(struct fsg_dev *fsg)
 
 /*-------------------------------------------------------------------------*/
 
-static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh)
+static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
 {
-        struct fsg_lun *curlun = fsg->common->curlun;
+        struct fsg_lun *curlun = common->curlun;
         u8      *buf = (u8 *) bh->buf;
 
         if (!curlun) {          /* Unsupported LUNs are okay */
-                fsg->bad_lun_okay = 1;
+                common->bad_lun_okay = 1;
                 memset(buf, 0, 36);
                 buf[0] = 0x7f;          /* Unsupported, no device-type */
                 buf[4] = 31;            /* Additional length */
@@ -1127,15 +1153,14 @@ static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh)
         buf[5] = 0;             /* No special options */
         buf[6] = 0;
         buf[7] = 0;
-        memcpy(buf + 8, fsg->common->inquiry_string,
-               sizeof fsg->common->inquiry_string);
+        memcpy(buf + 8, common->inquiry_string, sizeof common->inquiry_string);
         return 36;
 }
 
 
-static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
+static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
 {
-        struct fsg_lun  *curlun = fsg->common->curlun;
+        struct fsg_lun  *curlun = common->curlun;
         u8              *buf = (u8 *) bh->buf;
         u32             sd, sdinfo;
         int             valid;
@@ -1163,7 +1188,7 @@ static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 #endif
 
         if (!curlun) {          /* Unsupported LUNs are okay */
-                fsg->bad_lun_okay = 1;
+                common->bad_lun_okay = 1;
                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
                 sdinfo = 0;
                 valid = 0;
@@ -1187,11 +1212,11 @@ static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 }
 
 
-static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh)
+static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
 {
-        struct fsg_lun  *curlun = fsg->common->curlun;
-        u32             lba = get_unaligned_be32(&fsg->common->cmnd[2]);
-        int             pmi = fsg->common->cmnd[8];
+        struct fsg_lun  *curlun = common->curlun;
+        u32             lba = get_unaligned_be32(&common->cmnd[2]);
+        int             pmi = common->cmnd[8];
         u8              *buf = (u8 *) bh->buf;
 
         /* Check the PMI and LBA fields */
@@ -1207,14 +1232,14 @@ static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 }
 
 
-static int do_read_header(struct fsg_dev *fsg, struct fsg_buffhd *bh)
+static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
 {
-        struct fsg_lun  *curlun = fsg->common->curlun;
-        int             msf = fsg->common->cmnd[1] & 0x02;
-        u32             lba = get_unaligned_be32(&fsg->common->cmnd[2]);
+        struct fsg_lun  *curlun = common->curlun;
+        int             msf = common->cmnd[1] & 0x02;
+        u32             lba = get_unaligned_be32(&common->cmnd[2]);
         u8              *buf = (u8 *) bh->buf;
 
-        if ((fsg->common->cmnd[1] & ~0x02) != 0) {      /* Mask away MSF */
+        if (common->cmnd[1] & ~0x02) {          /* Mask away MSF */
                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
                 return -EINVAL;
         }
@@ -1230,14 +1255,14 @@ static int do_read_header(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 }
 
 
-static int do_read_toc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
+static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
 {
-        struct fsg_lun  *curlun = fsg->common->curlun;
-        int             msf = fsg->common->cmnd[1] & 0x02;
-        int             start_track = fsg->common->cmnd[6];
+        struct fsg_lun  *curlun = common->curlun;
+        int             msf = common->cmnd[1] & 0x02;
+        int             start_track = common->cmnd[6];
         u8              *buf = (u8 *) bh->buf;
 
-        if ((fsg->common->cmnd[1] & ~0x02) != 0 ||      /* Mask away MSF */
+        if ((common->cmnd[1] & ~0x02) != 0 ||   /* Mask away MSF */
                         start_track > 1) {
                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
                 return -EINVAL;
@@ -1258,10 +1283,10 @@ static int do_read_toc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 }
 
 
-static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
+static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
 {
-        struct fsg_lun  *curlun = fsg->common->curlun;
-        int             mscmnd = fsg->common->cmnd[0];
+        struct fsg_lun  *curlun = common->curlun;
+        int             mscmnd = common->cmnd[0];
         u8              *buf = (u8 *) bh->buf;
         u8              *buf0 = buf;
         int             pc, page_code;
@@ -1269,12 +1294,12 @@ static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
         int             valid_page = 0;
         int             len, limit;
 
-        if ((fsg->common->cmnd[1] & ~0x08) != 0) {      /* Mask away DBD */
+        if ((common->cmnd[1] & ~0x08) != 0) {   /* Mask away DBD */
                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
                 return -EINVAL;
         }
-        pc = fsg->common->cmnd[2] >> 6;
-        page_code = fsg->common->cmnd[2] & 0x3f;
+        pc = common->cmnd[2] >> 6;
+        page_code = common->cmnd[2] & 0x3f;
         if (pc == 3) {
                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
                 return -EINVAL;
@@ -1339,32 +1364,32 @@ static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 }
 
 
-static int do_start_stop(struct fsg_dev *fsg)
+static int do_start_stop(struct fsg_common *common)
 {
-        if (!fsg->common->curlun) {
+        if (!common->curlun) {
                 return -EINVAL;
-        } else if (!fsg->common->curlun->removable) {
-                fsg->common->curlun->sense_data = SS_INVALID_COMMAND;
+        } else if (!common->curlun->removable) {
+                common->curlun->sense_data = SS_INVALID_COMMAND;
                 return -EINVAL;
         }
         return 0;
 }
 
 
-static int do_prevent_allow(struct fsg_dev *fsg)
+static int do_prevent_allow(struct fsg_common *common)
 {
-        struct fsg_lun  *curlun = fsg->common->curlun;
+        struct fsg_lun  *curlun = common->curlun;
         int             prevent;
 
-        if (!fsg->common->curlun) {
+        if (!common->curlun) {
                 return -EINVAL;
-        } else if (!fsg->common->curlun->removable) {
-                fsg->common->curlun->sense_data = SS_INVALID_COMMAND;
+        } else if (!common->curlun->removable) {
+                common->curlun->sense_data = SS_INVALID_COMMAND;
                 return -EINVAL;
         }
 
-        prevent = fsg->common->cmnd[4] & 0x01;
-        if ((fsg->common->cmnd[4] & ~0x01) != 0) {      /* Mask away Prevent */
+        prevent = common->cmnd[4] & 0x01;
+        if ((common->cmnd[4] & ~0x01) != 0) {   /* Mask away Prevent */
                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
                 return -EINVAL;
         }
@@ -1376,10 +1401,10 @@ static int do_prevent_allow(struct fsg_dev *fsg)
 }
 
 
-static int do_read_format_capacities(struct fsg_dev *fsg,
+static int do_read_format_capacities(struct fsg_common *common,
                         struct fsg_buffhd *bh)
 {
-        struct fsg_lun  *curlun = fsg->common->curlun;
+        struct fsg_lun  *curlun = common->curlun;
         u8              *buf = (u8 *) bh->buf;
 
         buf[0] = buf[1] = buf[2] = 0;
@@ -1394,12 +1419,13 @@ static int do_read_format_capacities(struct fsg_dev *fsg,
 }
 
 
-static int do_mode_select(struct fsg_dev *fsg, struct fsg_buffhd *bh)
+static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
 {
-        struct fsg_lun  *curlun = fsg->common->curlun;
+        struct fsg_lun  *curlun = common->curlun;
 
         /* We don't support MODE SELECT */
-        curlun->sense_data = SS_INVALID_COMMAND;
+        if (curlun)
+                curlun->sense_data = SS_INVALID_COMMAND;
         return -EINVAL;
 }
 
@@ -1459,73 +1485,78 @@ static int pad_with_zeros(struct fsg_dev *fsg)
         int                     rc;
 
         bh->state = BUF_STATE_EMPTY;            /* For the first iteration */
-        fsg->usb_amount_left = nkeep + fsg->residue;
-        while (fsg->usb_amount_left > 0) {
+        fsg->common->usb_amount_left = nkeep + fsg->common->residue;
+        while (fsg->common->usb_amount_left > 0) {
 
                 /* Wait for the next buffer to be free */
                 while (bh->state != BUF_STATE_EMPTY) {
-                        rc = sleep_thread(fsg);
+                        rc = sleep_thread(fsg->common);
                         if (rc)
                                 return rc;
                 }
 
-                nsend = min(fsg->usb_amount_left, FSG_BUFLEN);
+                nsend = min(fsg->common->usb_amount_left, FSG_BUFLEN);
                 memset(bh->buf + nkeep, 0, nsend - nkeep);
                 bh->inreq->length = nsend;
                 bh->inreq->zero = 0;
                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
                                 &bh->inreq_busy, &bh->state);
                 bh = fsg->common->next_buffhd_to_fill = bh->next;
-                fsg->usb_amount_left -= nsend;
+                fsg->common->usb_amount_left -= nsend;
                 nkeep = 0;
         }
         return 0;
 }
 
-static int throw_away_data(struct fsg_dev *fsg)
+static int throw_away_data(struct fsg_common *common)
 {
         struct fsg_buffhd       *bh;
         u32                     amount;
         int                     rc;
 
-        for (bh = fsg->common->next_buffhd_to_drain;
-             bh->state != BUF_STATE_EMPTY || fsg->usb_amount_left > 0;
-             bh = fsg->common->next_buffhd_to_drain) {
+        for (bh = common->next_buffhd_to_drain;
+             bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
+             bh = common->next_buffhd_to_drain) {
 
                 /* Throw away the data in a filled buffer */
                 if (bh->state == BUF_STATE_FULL) {
                         smp_rmb();
                         bh->state = BUF_STATE_EMPTY;
-                        fsg->common->next_buffhd_to_drain = bh->next;
+                        common->next_buffhd_to_drain = bh->next;
 
                         /* A short packet or an error ends everything */
                         if (bh->outreq->actual != bh->outreq->length ||
                                         bh->outreq->status != 0) {
-                                raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
+                                raise_exception(common,
+                                                FSG_STATE_ABORT_BULK_OUT);
                                 return -EINTR;
                         }
                         continue;
                 }
 
                 /* Try to submit another request if we need one */
-                bh = fsg->common->next_buffhd_to_fill;
-                if (bh->state == BUF_STATE_EMPTY && fsg->usb_amount_left > 0) {
-                        amount = min(fsg->usb_amount_left, FSG_BUFLEN);
+                bh = common->next_buffhd_to_fill;
+                if (bh->state == BUF_STATE_EMPTY
+                 && common->usb_amount_left > 0) {
+                        amount = min(common->usb_amount_left, FSG_BUFLEN);
 
                         /* amount is always divisible by 512, hence by
                          * the bulk-out maxpacket size */
                         bh->outreq->length = amount;
                         bh->bulk_out_intended_length = amount;
                         bh->outreq->short_not_ok = 1;
-                        start_transfer(fsg, fsg->bulk_out, bh->outreq,
-                                        &bh->outreq_busy, &bh->state);
-                        fsg->common->next_buffhd_to_fill = bh->next;
-                        fsg->usb_amount_left -= amount;
+                        START_TRANSFER_OR(common, bulk_out, bh->outreq,
+                                          &bh->outreq_busy, &bh->state)
+                                /* Don't know what to do if
+                                 * common->fsg is NULL */
+                                return -EIO;
+                        common->next_buffhd_to_fill = bh->next;
+                        common->usb_amount_left -= amount;
                         continue;
                 }
 
                 /* Otherwise wait for something to happen */
-                rc = sleep_thread(fsg);
+                rc = sleep_thread(common);
                 if (rc)
                         return rc;
         }
@@ -1533,12 +1564,12 @@ static int throw_away_data(struct fsg_dev *fsg)
 }
 
 
-static int finish_reply(struct fsg_dev *fsg)
+static int finish_reply(struct fsg_common *common)
 {
-        struct fsg_buffhd       *bh = fsg->common->next_buffhd_to_fill;
+        struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
         int                     rc = 0;
 
-        switch (fsg->data_dir) {
+        switch (common->data_dir) {
         case DATA_DIR_NONE:
                 break;                  /* Nothing to send */
 
@@ -1547,47 +1578,60 @@ static int finish_reply(struct fsg_dev *fsg)
          * try to send or receive any data.  So stall both bulk pipes
          * if we can and wait for a reset. */
         case DATA_DIR_UNKNOWN:
-                if (fsg->can_stall) {
-                        fsg_set_halt(fsg, fsg->bulk_out);
-                        rc = halt_bulk_in_endpoint(fsg);
+                if (!common->can_stall) {
+                        /* Nothing */
+                } else if (fsg_is_set(common)) {
+                        fsg_set_halt(common->fsg, common->fsg->bulk_out);
+                        rc = halt_bulk_in_endpoint(common->fsg);
+                } else {
+                        /* Don't know what to do if common->fsg is NULL */
+                        rc = -EIO;
                 }
                 break;
 
         /* All but the last buffer of data must have already been sent */
         case DATA_DIR_TO_HOST:
-                if (fsg->data_size == 0) {
+                if (common->data_size == 0) {
                         /* Nothing to send */
 
                 /* If there's no residue, simply send the last buffer */
-                } else if (fsg->residue == 0) {
+                } else if (common->residue == 0) {
                         bh->inreq->zero = 0;
-                        start_transfer(fsg, fsg->bulk_in, bh->inreq,
-                                        &bh->inreq_busy, &bh->state);
-                        fsg->common->next_buffhd_to_fill = bh->next;
+                        START_TRANSFER_OR(common, bulk_in, bh->inreq,
+                                          &bh->inreq_busy, &bh->state)
+                                return -EIO;
+                        common->next_buffhd_to_fill = bh->next;
 
                 /* For Bulk-only, if we're allowed to stall then send the
                  * short packet and halt the bulk-in endpoint.  If we can't
                  * stall, pad out the remaining data with 0's. */
-                } else if (fsg->can_stall) {
+                } else if (common->can_stall) {
                         bh->inreq->zero = 1;
-                        start_transfer(fsg, fsg->bulk_in, bh->inreq,
-                                       &bh->inreq_busy, &bh->state);
-                        fsg->common->next_buffhd_to_fill = bh->next;
-                        rc = halt_bulk_in_endpoint(fsg);
+                        START_TRANSFER_OR(common, bulk_in, bh->inreq,
+                                          &bh->inreq_busy, &bh->state)
+                                /* Don't know what to do if
+                                 * common->fsg is NULL */
+                                rc = -EIO;
+                        common->next_buffhd_to_fill = bh->next;
+                        if (common->fsg)
+                                rc = halt_bulk_in_endpoint(common->fsg);
+                } else if (fsg_is_set(common)) {
+                        rc = pad_with_zeros(common->fsg);
                 } else {
-                        rc = pad_with_zeros(fsg);
+                        /* Don't know what to do if common->fsg is NULL */
+                        rc = -EIO;
                 }
                 break;
 
         /* We have processed all we want from the data the host has sent.
          * There may still be outstanding bulk-out requests. */
         case DATA_DIR_FROM_HOST:
-                if (fsg->residue == 0) {
+                if (common->residue == 0) {
                         /* Nothing to receive */
 
                 /* Did the host stop sending unexpectedly early? */
-                } else if (fsg->short_packet_received) {
-                        raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
+                } else if (common->short_packet_received) {
+                        raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
                         rc = -EINTR;
 
                 /* We haven't processed all the incoming data.  Even though
@@ -1597,16 +1641,18 @@ static int finish_reply(struct fsg_dev *fsg)
                  * STALL.  Not realizing the endpoint was halted, it wouldn't
                  * clear the halt -- leading to problems later on. */
 #if 0
-                } else if (fsg->can_stall) {
-                        fsg_set_halt(fsg, fsg->bulk_out);
-                        raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
+                } else if (common->can_stall) {
+                        if (fsg_is_set(common))
+                                fsg_set_halt(common->fsg,
+                                             common->fsg->bulk_out);
+                        raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
                         rc = -EINTR;
 #endif
 
                 /* We can't stall.  Read in the excess data and throw it
                  * all away. */
                 } else {
-                        rc = throw_away_data(fsg);
+                        rc = throw_away_data(common);
                 }
                 break;
         }
@@ -1614,9 +1660,9 @@ static int finish_reply(struct fsg_dev *fsg)
 }
 
 
-static int send_status(struct fsg_dev *fsg)
+static int send_status(struct fsg_common *common)
 {
-        struct fsg_lun          *curlun = fsg->common->curlun;
+        struct fsg_lun          *curlun = common->curlun;
         struct fsg_buffhd       *bh;
         struct bulk_cs_wrap     *csw;
         int                     rc;
@@ -1624,9 +1670,9 @@ static int send_status(struct fsg_dev *fsg)
         u32                     sd, sdinfo = 0;
 
         /* Wait for the next buffer to become available */
-        bh = fsg->common->next_buffhd_to_fill;
+        bh = common->next_buffhd_to_fill;
         while (bh->state != BUF_STATE_EMPTY) {
-                rc = sleep_thread(fsg);
+                rc = sleep_thread(common);
                 if (rc)
                         return rc;
         }
@@ -1634,19 +1680,19 @@ static int send_status(struct fsg_dev *fsg)
         if (curlun) {
                 sd = curlun->sense_data;
                 sdinfo = curlun->sense_data_info;
-        } else if (fsg->bad_lun_okay)
+        } else if (common->bad_lun_okay)
                 sd = SS_NO_SENSE;
         else
                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
 
-        if (fsg->phase_error) {
-                DBG(fsg, "sending phase-error status\n");
+        if (common->phase_error) {
+                DBG(common, "sending phase-error status\n");
                 status = USB_STATUS_PHASE_ERROR;
                 sd = SS_INVALID_COMMAND;
         } else if (sd != SS_NO_SENSE) {
-                DBG(fsg, "sending command-failure status\n");
+                DBG(common, "sending command-failure status\n");
                 status = USB_STATUS_FAIL;
-                VDBG(fsg, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
+                VDBG(common, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
                                 "  info x%x\n",
                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
         }
@@ -1655,16 +1701,18 @@ static int send_status(struct fsg_dev *fsg)
         csw = (void *)bh->buf;
 
         csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
-        csw->Tag = fsg->tag;
-        csw->Residue = cpu_to_le32(fsg->residue);
+        csw->Tag = common->tag;
+        csw->Residue = cpu_to_le32(common->residue);
         csw->Status = status;
 
         bh->inreq->length = USB_BULK_CS_WRAP_LEN;
         bh->inreq->zero = 0;
-        start_transfer(fsg, fsg->bulk_in, bh->inreq,
-                       &bh->inreq_busy, &bh->state);
+        START_TRANSFER_OR(common, bulk_in, bh->inreq,
+                          &bh->inreq_busy, &bh->state)
+                /* Don't know what to do if common->fsg is NULL */
+                return -EIO;
 
-        fsg->common->next_buffhd_to_fill = bh->next;
+        common->next_buffhd_to_fill = bh->next;
         return 0;
 }
 
@@ -1673,52 +1721,47 @@ static int send_status(struct fsg_dev *fsg)
 
 /* Check whether the command is properly formed and whether its data size
  * and direction agree with the values we already have. */
-static int check_command(struct fsg_dev *fsg, int cmnd_size,
+static int check_command(struct fsg_common *common, int cmnd_size,
                 enum data_direction data_dir, unsigned int mask,
                 int needs_medium, const char *name)
 {
         int                     i;
-        int                     lun = fsg->common->cmnd[1] >> 5;
+        int                     lun = common->cmnd[1] >> 5;
         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
         char                    hdlen[20];
         struct fsg_lun          *curlun;
 
         hdlen[0] = 0;
-        if (fsg->data_dir != DATA_DIR_UNKNOWN)
-                sprintf(hdlen, ", H%c=%u", dirletter[(int) fsg->data_dir],
-                                fsg->data_size);
-        VDBG(fsg, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
+        if (common->data_dir != DATA_DIR_UNKNOWN)
+                sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
+                                common->data_size);
+        VDBG(common, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
              name, cmnd_size, dirletter[(int) data_dir],
-             fsg->data_size_from_cmnd, fsg->common->cmnd_size, hdlen);
+             common->data_size_from_cmnd, common->cmnd_size, hdlen);
 
         /* We can't reply at all until we know the correct data direction
          * and size. */
-        if (fsg->data_size_from_cmnd == 0)
+        if (common->data_size_from_cmnd == 0)
                 data_dir = DATA_DIR_NONE;
-        if (fsg->data_dir == DATA_DIR_UNKNOWN) {        /* CB or CBI */
-                fsg->data_dir = data_dir;
-                fsg->data_size = fsg->data_size_from_cmnd;
-
-        } else {                                        /* Bulk-only */
-                if (fsg->data_size < fsg->data_size_from_cmnd) {
-
-                        /* Host data size < Device data size is a phase error.
-                         * Carry out the command, but only transfer as much
-                         * as we are allowed. */
-                        fsg->data_size_from_cmnd = fsg->data_size;
-                        fsg->phase_error = 1;
-                }
+        if (common->data_size < common->data_size_from_cmnd) {
+                /* Host data size < Device data size is a phase error.
+                 * Carry out the command, but only transfer as much as
+                 * we are allowed. */
+                common->data_size_from_cmnd = common->data_size;
+                common->phase_error = 1;
         }
-        fsg->residue = fsg->usb_amount_left = fsg->data_size;
+        common->residue = common->data_size;
+        common->usb_amount_left = common->data_size;
 
         /* Conflicting data directions is a phase error */
-        if (fsg->data_dir != data_dir && fsg->data_size_from_cmnd > 0) {
-                fsg->phase_error = 1;
+        if (common->data_dir != data_dir
+         && common->data_size_from_cmnd > 0) {
+                common->phase_error = 1;
                 return -EINVAL;
         }
 
         /* Verify the length of the command itself */
-        if (cmnd_size != fsg->common->cmnd_size) {
+        if (cmnd_size != common->cmnd_size) {
 
                 /* Special case workaround: There are plenty of buggy SCSI
                  * implementations. Many have issues with cbw->Length
@@ -1732,40 +1775,41 @@ static int check_command(struct fsg_dev *fsg, int cmnd_size,
                  * REQUEST SENSE with cbw->Length == 10 where it should
                  * be 6 as well.
                  */
-                if (cmnd_size <= fsg->common->cmnd_size) {
-                        DBG(fsg, "%s is buggy! Expected length %d "
+                if (cmnd_size <= common->cmnd_size) {
+                        DBG(common, "%s is buggy! Expected length %d "
                             "but we got %d\n", name,
-                            cmnd_size, fsg->common->cmnd_size);
-                        cmnd_size = fsg->common->cmnd_size;
+                            cmnd_size, common->cmnd_size);
+                        cmnd_size = common->cmnd_size;
                 } else {
-                        fsg->phase_error = 1;
+                        common->phase_error = 1;
                         return -EINVAL;
                 }
         }
 
         /* Check that the LUN values are consistent */
-        if (fsg->common->lun != lun)
-                DBG(fsg, "using LUN %d from CBW, not LUN %d from CDB\n",
-                    fsg->common->lun, lun);
+        if (common->lun != lun)
+                DBG(common, "using LUN %d from CBW, not LUN %d from CDB\n",
+                    common->lun, lun);
 
         /* Check the LUN */
-        if (fsg->common->lun >= 0 && fsg->common->lun < fsg->common->nluns) {
-                curlun = &fsg->common->luns[fsg->common->lun];
-                fsg->common->curlun = curlun;
-                if (fsg->common->cmnd[0] != SC_REQUEST_SENSE) {
+        if (common->lun >= 0 && common->lun < common->nluns) {
+                curlun = &common->luns[common->lun];
+                common->curlun = curlun;
+                if (common->cmnd[0] != SC_REQUEST_SENSE) {
                         curlun->sense_data = SS_NO_SENSE;
                         curlun->sense_data_info = 0;
                         curlun->info_valid = 0;
                 }
         } else {
-                fsg->common->curlun = curlun = NULL;
-                fsg->bad_lun_okay = 0;
+                common->curlun = NULL;
+                curlun = NULL;
+                common->bad_lun_okay = 0;
 
                 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
                  * to use unsupported LUNs; all others may not. */
-                if (fsg->common->cmnd[0] != SC_INQUIRY &&
-                    fsg->common->cmnd[0] != SC_REQUEST_SENSE) {
-                        DBG(fsg, "unsupported LUN %d\n", fsg->common->lun);
+                if (common->cmnd[0] != SC_INQUIRY &&
+                    common->cmnd[0] != SC_REQUEST_SENSE) {
+                        DBG(common, "unsupported LUN %d\n", common->lun);
                         return -EINVAL;
                 }
         }
@@ -1773,17 +1817,17 @@ static int check_command(struct fsg_dev *fsg, int cmnd_size,
         /* If a unit attention condition exists, only INQUIRY and
          * REQUEST SENSE commands are allowed; anything else must fail. */
         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
-                        fsg->common->cmnd[0] != SC_INQUIRY &&
-                        fsg->common->cmnd[0] != SC_REQUEST_SENSE) {
+                        common->cmnd[0] != SC_INQUIRY &&
+                        common->cmnd[0] != SC_REQUEST_SENSE) {
                 curlun->sense_data = curlun->unit_attention_data;
                 curlun->unit_attention_data = SS_NO_SENSE;
                 return -EINVAL;
         }
 
         /* Check that only command bytes listed in the mask are non-zero */
-        fsg->common->cmnd[1] &= 0x1f;                   /* Mask away the LUN */
+        common->cmnd[1] &= 0x1f;                        /* Mask away the LUN */
         for (i = 1; i < cmnd_size; ++i) {
-                if (fsg->common->cmnd[i] && !(mask & (1 << i))) {
+                if (common->cmnd[i] && !(mask & (1 << i))) {
                         if (curlun)
                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
                         return -EINVAL;
@@ -1801,7 +1845,7 @@ static int check_command(struct fsg_dev *fsg, int cmnd_size,
 }
 
 
-static int do_scsi_command(struct fsg_dev *fsg)
+static int do_scsi_command(struct fsg_common *common)
 {
         struct fsg_buffhd       *bh;
         int                     rc;
@@ -1809,182 +1853,181 @@ static int do_scsi_command(struct fsg_dev *fsg)
         int                     i;
         static char             unknown[16];
 
-        dump_cdb(fsg->common);
+        dump_cdb(common);
 
         /* Wait for the next buffer to become available for data or status */
-        bh = fsg->common->next_buffhd_to_fill;
-        fsg->common->next_buffhd_to_drain = bh;
+        bh = common->next_buffhd_to_fill;
+        common->next_buffhd_to_drain = bh;
         while (bh->state != BUF_STATE_EMPTY) {
-                rc = sleep_thread(fsg);
+                rc = sleep_thread(common);
                 if (rc)
                         return rc;
         }
-        fsg->phase_error = 0;
-        fsg->short_packet_received = 0;
+        common->phase_error = 0;
+        common->short_packet_received = 0;
 
-        /* We're using the backing file */
-        down_read(&fsg->common->filesem);
-        switch (fsg->common->cmnd[0]) {
+        down_read(&common->filesem);    /* We're using the backing file */
+        switch (common->cmnd[0]) {
 
         case SC_INQUIRY:
-                fsg->data_size_from_cmnd = fsg->common->cmnd[4];
-                reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
+                common->data_size_from_cmnd = common->cmnd[4];
+                reply = check_command(common, 6, DATA_DIR_TO_HOST,
                                       (1<<4), 0,
                                       "INQUIRY");
                 if (reply == 0)
-                        reply = do_inquiry(fsg, bh);
+                        reply = do_inquiry(common, bh);
                 break;
 
         case SC_MODE_SELECT_6:
-                fsg->data_size_from_cmnd = fsg->common->cmnd[4];
-                reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
+                common->data_size_from_cmnd = common->cmnd[4];
+                reply = check_command(common, 6, DATA_DIR_FROM_HOST,
                                       (1<<1) | (1<<4), 0,
                                       "MODE SELECT(6)");
                 if (reply == 0)
-                        reply = do_mode_select(fsg, bh);
+                        reply = do_mode_select(common, bh);
                 break;
 
         case SC_MODE_SELECT_10:
-                fsg->data_size_from_cmnd =
-                        get_unaligned_be16(&fsg->common->cmnd[7]);
-                reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
+                common->data_size_from_cmnd =
+                        get_unaligned_be16(&common->cmnd[7]);
+                reply = check_command(common, 10, DATA_DIR_FROM_HOST,
                                       (1<<1) | (3<<7), 0,
                                       "MODE SELECT(10)");
                 if (reply == 0)
-                        reply = do_mode_select(fsg, bh);
+                        reply = do_mode_select(common, bh);
                 break;
 
         case SC_MODE_SENSE_6:
-                fsg->data_size_from_cmnd = fsg->common->cmnd[4];
-                reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
+                common->data_size_from_cmnd = common->cmnd[4];
+                reply = check_command(common, 6, DATA_DIR_TO_HOST,
                                       (1<<1) | (1<<2) | (1<<4), 0,
                                       "MODE SENSE(6)");
                 if (reply == 0)
-                        reply = do_mode_sense(fsg, bh);
+                        reply = do_mode_sense(common, bh);
                 break;
 
         case SC_MODE_SENSE_10:
-                fsg->data_size_from_cmnd =
-                        get_unaligned_be16(&fsg->common->cmnd[7]);
-                reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
+                common->data_size_from_cmnd =
+                        get_unaligned_be16(&common->cmnd[7]);
+                reply = check_command(common, 10, DATA_DIR_TO_HOST,
                                       (1<<1) | (1<<2) | (3<<7), 0,
                                       "MODE SENSE(10)");
                 if (reply == 0)
-                        reply = do_mode_sense(fsg, bh);
+                        reply = do_mode_sense(common, bh);
                 break;
 
         case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
-                fsg->data_size_from_cmnd = 0;
-                reply = check_command(fsg, 6, DATA_DIR_NONE,
+                common->data_size_from_cmnd = 0;
+                reply = check_command(common, 6, DATA_DIR_NONE,
                                       (1<<4), 0,
                                       "PREVENT-ALLOW MEDIUM REMOVAL");
                 if (reply == 0)
-                        reply = do_prevent_allow(fsg);
+                        reply = do_prevent_allow(common);
                 break;
 
         case SC_READ_6:
-                i = fsg->common->cmnd[4];
-                fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
-                reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
+                i = common->cmnd[4];
+                common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
+                reply = check_command(common, 6, DATA_DIR_TO_HOST,
                                       (7<<1) | (1<<4), 1,
                                       "READ(6)");
                 if (reply == 0)
-                        reply = do_read(fsg);
+                        reply = do_read(common);
                 break;
 
         case SC_READ_10:
-                fsg->data_size_from_cmnd =
-                                get_unaligned_be16(&fsg->common->cmnd[7]) << 9;
-                reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
+                common->data_size_from_cmnd =
+                                get_unaligned_be16(&common->cmnd[7]) << 9;
+                reply = check_command(common, 10, DATA_DIR_TO_HOST,
                                       (1<<1) | (0xf<<2) | (3<<7), 1,
                                       "READ(10)");
                 if (reply == 0)
-                        reply = do_read(fsg);
+                        reply = do_read(common);
                 break;
 
         case SC_READ_12:
-                fsg->data_size_from_cmnd =
-                                get_unaligned_be32(&fsg->common->cmnd[6]) << 9;
-                reply = check_command(fsg, 12, DATA_DIR_TO_HOST,
+                common->data_size_from_cmnd =
+                                get_unaligned_be32(&common->cmnd[6]) << 9;
+                reply = check_command(common, 12, DATA_DIR_TO_HOST,
                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
                                       "READ(12)");
                 if (reply == 0)
-                        reply = do_read(fsg);
+                        reply = do_read(common);
                 break;
 
         case SC_READ_CAPACITY:
-                fsg->data_size_from_cmnd = 8;
-                reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
+                common->data_size_from_cmnd = 8;
+                reply = check_command(common, 10, DATA_DIR_TO_HOST,
                                       (0xf<<2) | (1<<8), 1,
                                       "READ CAPACITY");
                 if (reply == 0)
-                        reply = do_read_capacity(fsg, bh);
+                        reply = do_read_capacity(common, bh);
                 break;
 
         case SC_READ_HEADER:
-                if (!fsg->common->curlun || !fsg->common->curlun->cdrom)
+                if (!common->curlun || !common->curlun->cdrom)
                         goto unknown_cmnd;
-                fsg->data_size_from_cmnd =
-                        get_unaligned_be16(&fsg->common->cmnd[7]);
-                reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
+                common->data_size_from_cmnd =
+                        get_unaligned_be16(&common->cmnd[7]);
+                reply = check_command(common, 10, DATA_DIR_TO_HOST,
                                       (3<<7) | (0x1f<<1), 1,
                                       "READ HEADER");
                 if (reply == 0)
-                        reply = do_read_header(fsg, bh);
+                        reply = do_read_header(common, bh);
                 break;
 
         case SC_READ_TOC:
-                if (!fsg->common->curlun || !fsg->common->curlun->cdrom)
+                if (!common->curlun || !common->curlun->cdrom)
                         goto unknown_cmnd;
-                fsg->data_size_from_cmnd =
-                        get_unaligned_be16(&fsg->common->cmnd[7]);
-                reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
+                common->data_size_from_cmnd =
+                        get_unaligned_be16(&common->cmnd[7]);
+                reply = check_command(common, 10, DATA_DIR_TO_HOST,
                                       (7<<6) | (1<<1), 1,
                                       "READ TOC");
                 if (reply == 0)
-                        reply = do_read_toc(fsg, bh);
+                        reply = do_read_toc(common, bh);
                 break;
 
         case SC_READ_FORMAT_CAPACITIES:
-                fsg->data_size_from_cmnd =
-                        get_unaligned_be16(&fsg->common->cmnd[7]);
-                reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
+                common->data_size_from_cmnd =
+                        get_unaligned_be16(&common->cmnd[7]);
+                reply = check_command(common, 10, DATA_DIR_TO_HOST,
                                       (3<<7), 1,
                                       "READ FORMAT CAPACITIES");
                 if (reply == 0)
-                        reply = do_read_format_capacities(fsg, bh);
+                        reply = do_read_format_capacities(common, bh);
                 break;
 
         case SC_REQUEST_SENSE:
-                fsg->data_size_from_cmnd = fsg->common->cmnd[4];
-                reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
+                common->data_size_from_cmnd = common->cmnd[4];
+                reply = check_command(common, 6, DATA_DIR_TO_HOST,
                                       (1<<4), 0,
                                       "REQUEST SENSE");
                 if (reply == 0)
-                        reply = do_request_sense(fsg, bh);
+                        reply = do_request_sense(common, bh);
                 break;
 
         case SC_START_STOP_UNIT:
-                fsg->data_size_from_cmnd = 0;
-                reply = check_command(fsg, 6, DATA_DIR_NONE,
+                common->data_size_from_cmnd = 0;
+                reply = check_command(common, 6, DATA_DIR_NONE,
                                       (1<<1) | (1<<4), 0,
                                       "START-STOP UNIT");
                 if (reply == 0)
-                        reply = do_start_stop(fsg);
+                        reply = do_start_stop(common);
                 break;
 
         case SC_SYNCHRONIZE_CACHE:
-                fsg->data_size_from_cmnd = 0;
-                reply = check_command(fsg, 10, DATA_DIR_NONE,
+                common->data_size_from_cmnd = 0;
+                reply = check_command(common, 10, DATA_DIR_NONE,
                                       (0xf<<2) | (3<<7), 1,
                                       "SYNCHRONIZE CACHE");
                 if (reply == 0)
-                        reply = do_synchronize_cache(fsg);
+                        reply = do_synchronize_cache(common);
                 break;
 
         case SC_TEST_UNIT_READY:
-                fsg->data_size_from_cmnd = 0;
-                reply = check_command(fsg, 6, DATA_DIR_NONE,
+                common->data_size_from_cmnd = 0;
+                reply = check_command(common, 6, DATA_DIR_NONE,
                                 0, 1,
                                 "TEST UNIT READY");
                 break;
@@ -1992,42 +2035,42 @@ static int do_scsi_command(struct fsg_dev *fsg)
         /* Although optional, this command is used by MS-Windows.  We
          * support a minimal version: BytChk must be 0. */
         case SC_VERIFY:
-                fsg->data_size_from_cmnd = 0;
-                reply = check_command(fsg, 10, DATA_DIR_NONE,
+                common->data_size_from_cmnd = 0;
+                reply = check_command(common, 10, DATA_DIR_NONE,
                                       (1<<1) | (0xf<<2) | (3<<7), 1,
                                       "VERIFY");
                 if (reply == 0)
-                        reply = do_verify(fsg);
+                        reply = do_verify(common);
                 break;
 
         case SC_WRITE_6:
-                i = fsg->common->cmnd[4];
-                fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
-                reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
+                i = common->cmnd[4];
+                common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
+                reply = check_command(common, 6, DATA_DIR_FROM_HOST,
                                       (7<<1) | (1<<4), 1,
                                       "WRITE(6)");
                 if (reply == 0)
-                        reply = do_write(fsg);
+                        reply = do_write(common);
                 break;
 
         case SC_WRITE_10:
-                fsg->data_size_from_cmnd =
-                                get_unaligned_be16(&fsg->common->cmnd[7]) << 9;
-                reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
+                common->data_size_from_cmnd =
+                                get_unaligned_be16(&common->cmnd[7]) << 9;
+                reply = check_command(common, 10, DATA_DIR_FROM_HOST,
                                       (1<<1) | (0xf<<2) | (3<<7), 1,
                                       "WRITE(10)");
                 if (reply == 0)
-                        reply = do_write(fsg);
+                        reply = do_write(common);
                 break;
 
         case SC_WRITE_12:
-                fsg->data_size_from_cmnd =
-                                get_unaligned_be32(&fsg->common->cmnd[6]) << 9;
-                reply = check_command(fsg, 12, DATA_DIR_FROM_HOST,
+                common->data_size_from_cmnd =
+                                get_unaligned_be32(&common->cmnd[6]) << 9;
+                reply = check_command(common, 12, DATA_DIR_FROM_HOST,
                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
                                       "WRITE(12)");
                 if (reply == 0)
-                        reply = do_write(fsg);
+                        reply = do_write(common);
                 break;
 
         /* Some mandatory commands that we recognize but don't implement.
@@ -2042,17 +2085,17 @@ static int do_scsi_command(struct fsg_dev *fsg)
 
         default:
 unknown_cmnd:
-                fsg->data_size_from_cmnd = 0;
-                sprintf(unknown, "Unknown x%02x", fsg->common->cmnd[0]);
-                reply = check_command(fsg, fsg->common->cmnd_size,
+                common->data_size_from_cmnd = 0;
+                sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
+                reply = check_command(common, common->cmnd_size,
                                       DATA_DIR_UNKNOWN, 0xff, 0, unknown);
                 if (reply == 0) {
-                        fsg->common->curlun->sense_data = SS_INVALID_COMMAND;
+                        common->curlun->sense_data = SS_INVALID_COMMAND;
                         reply = -EINVAL;
                 }
                 break;
         }
-        up_read(&fsg->common->filesem);
+        up_read(&common->filesem);
 
         if (reply == -EINTR || signal_pending(current))
                 return -EINTR;
@@ -2060,11 +2103,11 @@ unknown_cmnd:
         /* Set up the single reply buffer for finish_reply() */
         if (reply == -EINVAL)
                 reply = 0;              /* Error reply length */
-        if (reply >= 0 && fsg->data_dir == DATA_DIR_TO_HOST) {
-                reply = min((u32) reply, fsg->data_size_from_cmnd);
+        if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
+                reply = min((u32) reply, common->data_size_from_cmnd);
                 bh->inreq->length = reply;
                 bh->state = BUF_STATE_FULL;
-                fsg->residue -= reply;
+                common->residue -= reply;
         }                               /* Otherwise it's already set */
 
         return 0;
@@ -2075,8 +2118,9 @@ unknown_cmnd:
 
 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 {
-        struct usb_request              *req = bh->outreq;
+        struct usb_request      *req = bh->outreq;
         struct fsg_bulk_cb_wrap *cbw = req->buf;
+        struct fsg_common       *common = fsg->common;
 
         /* Was this a real packet?  Should it be ignored? */
         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
@@ -2113,7 +2157,7 @@ static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 
                 /* We can do anything we want here, so let's stall the
                  * bulk pipes if we are allowed to. */
-                if (fsg->can_stall) {
+                if (common->can_stall) {
                         fsg_set_halt(fsg, fsg->bulk_out);
                         halt_bulk_in_endpoint(fsg);
                 }
@@ -2121,39 +2165,41 @@ static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
         }
 
         /* Save the command for later */
-        fsg->common->cmnd_size = cbw->Length;
-        memcpy(fsg->common->cmnd, cbw->CDB, fsg->common->cmnd_size);
+        common->cmnd_size = cbw->Length;
+        memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
         if (cbw->Flags & USB_BULK_IN_FLAG)
-                fsg->data_dir = DATA_DIR_TO_HOST;
+                common->data_dir = DATA_DIR_TO_HOST;
         else
-                fsg->data_dir = DATA_DIR_FROM_HOST;
-        fsg->data_size = le32_to_cpu(cbw->DataTransferLength);
-        if (fsg->data_size == 0)
-                fsg->data_dir = DATA_DIR_NONE;
-        fsg->common->lun = cbw->Lun;
-        fsg->tag = cbw->Tag;
+                common->data_dir = DATA_DIR_FROM_HOST;
+        common->data_size = le32_to_cpu(cbw->DataTransferLength);
+        if (common->data_size == 0)
+                common->data_dir = DATA_DIR_NONE;
+        common->lun = cbw->Lun;
+        common->tag = cbw->Tag;
         return 0;
 }
 
 
-static int get_next_command(struct fsg_dev *fsg)
+static int get_next_command(struct fsg_common *common)
 {
         struct fsg_buffhd       *bh;
         int                     rc = 0;
 
         /* Wait for the next buffer to become available */
-        bh = fsg->common->next_buffhd_to_fill;
+        bh = common->next_buffhd_to_fill;
         while (bh->state != BUF_STATE_EMPTY) {
-                rc = sleep_thread(fsg);
+                rc = sleep_thread(common);
                 if (rc)
                         return rc;
         }
 
         /* Queue a request to read a Bulk-only CBW */
-        set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN);
+        set_bulk_out_req_length(common, bh, USB_BULK_CB_WRAP_LEN);
         bh->outreq->short_not_ok = 1;
-        start_transfer(fsg, fsg->bulk_out, bh->outreq,
-                       &bh->outreq_busy, &bh->state);
+        START_TRANSFER_OR(common, bulk_out, bh->outreq,
+                          &bh->outreq_busy, &bh->state)
+                /* Don't know what to do if common->fsg is NULL */
+                return -EIO;
 
         /* We will drain the buffer in software, which means we
          * can reuse it for the next filling.  No need to advance
@@ -2161,12 +2207,12 @@ static int get_next_command(struct fsg_dev *fsg)
 
         /* Wait for the CBW to arrive */
         while (bh->state != BUF_STATE_FULL) {
-                rc = sleep_thread(fsg);
+                rc = sleep_thread(common);
                 if (rc)
                         return rc;
         }
         smp_rmb();
-        rc = received_cbw(fsg, bh);
+        rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
         bh->state = BUF_STATE_EMPTY;
 
         return rc;
@@ -2175,25 +2221,25 @@ static int get_next_command(struct fsg_dev *fsg)
 
 /*-------------------------------------------------------------------------*/
 
-static int enable_endpoint(struct fsg_dev *fsg, struct usb_ep *ep,
+static int enable_endpoint(struct fsg_common *common, struct usb_ep *ep,
                 const struct usb_endpoint_descriptor *d)
 {
         int     rc;
 
-        ep->driver_data = fsg;
+        ep->driver_data = common;
         rc = usb_ep_enable(ep, d);
         if (rc)
-                ERROR(fsg, "can't enable %s, result %d\n", ep->name, rc);
+                ERROR(common, "can't enable %s, result %d\n", ep->name, rc);
         return rc;
 }
 
-static int alloc_request(struct fsg_dev *fsg, struct usb_ep *ep,
+static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
                 struct usb_request **preq)
 {
         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
         if (*preq)
                 return 0;
-        ERROR(fsg, "can't allocate request for %s\n", ep->name);
+        ERROR(common, "can't allocate request for %s\n", ep->name);
         return -ENOMEM;
 }
 
@@ -2202,83 +2248,96 @@ static int alloc_request(struct fsg_dev *fsg, struct usb_ep *ep,
  * Call with altsetting < 0 to disable the interface.  The only other
  * available altsetting is 0, which enables the interface.
  */
-static int do_set_interface(struct fsg_dev *fsg, int altsetting)
+static int do_set_interface(struct fsg_common *common, int altsetting)
 {
         int     rc = 0;
         int     i;
         const struct usb_endpoint_descriptor    *d;
 
-        if (fsg->running)
-                DBG(fsg, "reset interface\n");
+        if (common->running)
+                DBG(common, "reset interface\n");
 
 reset:
         /* Deallocate the requests */
-        for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
-                struct fsg_buffhd *bh = &fsg->common->buffhds[i];
+        if (common->prev_fsg) {
+                struct fsg_dev *fsg = common->prev_fsg;
+
+                for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+                        struct fsg_buffhd *bh = &common->buffhds[i];
 
-                if (bh->inreq) {
-                        usb_ep_free_request(fsg->bulk_in, bh->inreq);
-                        bh->inreq = NULL;
+                        if (bh->inreq) {
+                                usb_ep_free_request(fsg->bulk_in, bh->inreq);
+                                bh->inreq = NULL;
+                        }
+                        if (bh->outreq) {
+                                usb_ep_free_request(fsg->bulk_out, bh->outreq);
+                                bh->outreq = NULL;
+                        }
                 }
-                if (bh->outreq) {
-                        usb_ep_free_request(fsg->bulk_out, bh->outreq);
-                        bh->outreq = NULL;
+
+                /* Disable the endpoints */
+                if (fsg->bulk_in_enabled) {
+                        usb_ep_disable(fsg->bulk_in);
+                        fsg->bulk_in_enabled = 0;
+                }
+                if (fsg->bulk_out_enabled) {
+                        usb_ep_disable(fsg->bulk_out);
+                        fsg->bulk_out_enabled = 0;
                 }
-        }
 
-        /* Disable the endpoints */
-        if (fsg->bulk_in_enabled) {
-                usb_ep_disable(fsg->bulk_in);
-                fsg->bulk_in_enabled = 0;
-        }
-        if (fsg->bulk_out_enabled) {
-                usb_ep_disable(fsg->bulk_out);
-                fsg->bulk_out_enabled = 0;
+                common->prev_fsg = 0;
         }
 
-        fsg->running = 0;
+        common->running = 0;
         if (altsetting < 0 || rc != 0)
                 return rc;
 
-        DBG(fsg, "set interface %d\n", altsetting);
-
-        /* Enable the endpoints */
-        d = fsg_ep_desc(fsg->gadget,
-                        &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
-        rc = enable_endpoint(fsg, fsg->bulk_in, d);
-        if (rc != 0)
-                goto reset;
-        fsg->bulk_in_enabled = 1;
-
-        d = fsg_ep_desc(fsg->gadget,
-                        &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
-        rc = enable_endpoint(fsg, fsg->bulk_out, d);
-        if (rc != 0)
-                goto reset;
-        fsg->bulk_out_enabled = 1;
-        fsg->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
-        clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
-
-        /* Allocate the requests */
-        for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
-                struct fsg_buffhd       *bh = &fsg->common->buffhds[i];
+        DBG(common, "set interface %d\n", altsetting);
 
-                rc = alloc_request(fsg, fsg->bulk_in, &bh->inreq);
-                if (rc != 0)
+        if (fsg_is_set(common)) {
+                struct fsg_dev *fsg = common->fsg;
+                common->prev_fsg = common->fsg;
+
+                /* Enable the endpoints */
+                d = fsg_ep_desc(common->gadget,
+                                &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
+                rc = enable_endpoint(common, fsg->bulk_in, d);
+                if (rc)
                         goto reset;
-                rc = alloc_request(fsg, fsg->bulk_out, &bh->outreq);
-                if (rc != 0)
+                fsg->bulk_in_enabled = 1;
+
+                d = fsg_ep_desc(common->gadget,
+                                &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
+                rc = enable_endpoint(common, fsg->bulk_out, d);
+                if (rc)
                         goto reset;
-                bh->inreq->buf = bh->outreq->buf = bh->buf;
-                bh->inreq->context = bh->outreq->context = bh;
-                bh->inreq->complete = bulk_in_complete;
-                bh->outreq->complete = bulk_out_complete;
-        }
+                fsg->bulk_out_enabled = 1;
+                common->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
+                clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
 
-        fsg->running = 1;
-        for (i = 0; i < fsg->common->nluns; ++i)
-                fsg->common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
-        return rc;
+                /* Allocate the requests */
+                for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+                        struct fsg_buffhd       *bh = &common->buffhds[i];
+
+                        rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
+                        if (rc)
+                                goto reset;
+                        rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
+                        if (rc)
+                                goto reset;
+                        bh->inreq->buf = bh->outreq->buf = bh->buf;
+                        bh->inreq->context = bh->outreq->context = bh;
+                        bh->inreq->complete = bulk_in_complete;
+                        bh->outreq->complete = bulk_out_complete;
+                }
+
+                common->running = 1;
+                for (i = 0; i < common->nluns; ++i)
+                        common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
+                return rc;
+        } else {
+                return -EIO;
+        }
 }
 
 
@@ -2290,23 +2349,23 @@ reset:
  * configurations might not work with our current power sources.
  * For now we just assume the gadget is always self-powered.
  */
-static int do_set_config(struct fsg_dev *fsg, u8 new_config)
+static int do_set_config(struct fsg_common *common, u8 new_config)
 {
         int     rc = 0;
 
         /* Disable the single interface */
-        if (fsg->config != 0) {
-                DBG(fsg, "reset config\n");
-                fsg->config = 0;
-                rc = do_set_interface(fsg, -1);
+        if (common->config != 0) {
+                DBG(common, "reset config\n");
+                common->config = 0;
+                rc = do_set_interface(common, -1);
         }
 
         /* Enable the interface */
         if (new_config != 0) {
-                fsg->config = new_config;
-                rc = do_set_interface(fsg, 0);
+                common->config = new_config;
+                rc = do_set_interface(common, 0);
                 if (rc != 0)
-                        fsg->config = 0;        /* Reset on errors */
+                        common->config = 0;     /* Reset on errors */
         }
         return rc;
 }
@@ -2318,22 +2377,26 @@ static int do_set_config(struct fsg_dev *fsg, u8 new_config)
 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 {
         struct fsg_dev *fsg = fsg_from_func(f);
-        fsg->new_config = 1;
-        raise_exception(fsg, FSG_STATE_CONFIG_CHANGE);
+        fsg->common->prev_fsg = fsg->common->fsg;
+        fsg->common->fsg = fsg;
+        fsg->common->new_config = 1;
+        raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
         return 0;
 }
 
 static void fsg_disable(struct usb_function *f)
 {
         struct fsg_dev *fsg = fsg_from_func(f);
-        fsg->new_config = 0;
-        raise_exception(fsg, FSG_STATE_CONFIG_CHANGE);
+        fsg->common->prev_fsg = fsg->common->fsg;
+        fsg->common->fsg = fsg;
+        fsg->common->new_config = 0;
+        raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
 }
 
 
 /*-------------------------------------------------------------------------*/
 
-static void handle_exception(struct fsg_dev *fsg)
+static void handle_exception(struct fsg_common *common)
 {
         siginfo_t               info;
         int                     sig;
@@ -2352,113 +2415,121 @@ static void handle_exception(struct fsg_dev *fsg)
                 if (!sig)
                         break;
                 if (sig != SIGUSR1) {
-                        if (fsg->state < FSG_STATE_EXIT)
-                                DBG(fsg, "Main thread exiting on signal\n");
-                        raise_exception(fsg, FSG_STATE_EXIT);
+                        if (common->state < FSG_STATE_EXIT)
+                                DBG(common, "Main thread exiting on signal\n");
+                        raise_exception(common, FSG_STATE_EXIT);
                 }
         }
 
         /* Cancel all the pending transfers */
-        for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
-                bh = &fsg->common->buffhds[i];
-                if (bh->inreq_busy)
-                        usb_ep_dequeue(fsg->bulk_in, bh->inreq);
-                if (bh->outreq_busy)
-                        usb_ep_dequeue(fsg->bulk_out, bh->outreq);
-        }
-
-        /* Wait until everything is idle */
-        for (;;) {
-                int num_active = 0;
+        if (fsg_is_set(common)) {
                 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
-                        bh = &fsg->common->buffhds[i];
-                        num_active += bh->inreq_busy + bh->outreq_busy;
+                        bh = &common->buffhds[i];
+                        if (bh->inreq_busy)
+                                usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
+                        if (bh->outreq_busy)
+                                usb_ep_dequeue(common->fsg->bulk_out,
+                                               bh->outreq);
                 }
-                if (num_active == 0)
-                        break;
-                if (sleep_thread(fsg))
-                        return;
-        }
 
-        /* Clear out the controller's fifos */
-        if (fsg->bulk_in_enabled)
-                usb_ep_fifo_flush(fsg->bulk_in);
-        if (fsg->bulk_out_enabled)
-                usb_ep_fifo_flush(fsg->bulk_out);
+                /* Wait until everything is idle */
+                for (;;) {
+                        int num_active = 0;
+                        for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+                                bh = &common->buffhds[i];
+                                num_active += bh->inreq_busy + bh->outreq_busy;
+                        }
+                        if (num_active == 0)
+                                break;
+                        if (sleep_thread(common))
+                                return;
+                }
+
+                /* Clear out the controller's fifos */
+                if (common->fsg->bulk_in_enabled)
+                        usb_ep_fifo_flush(common->fsg->bulk_in);
+                if (common->fsg->bulk_out_enabled)
+                        usb_ep_fifo_flush(common->fsg->bulk_out);
+        }
 
         /* Reset the I/O buffer states and pointers, the SCSI
          * state, and the exception.  Then invoke the handler. */
-        spin_lock_irq(&fsg->lock);
+        spin_lock_irq(&common->lock);
 
         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
-                bh = &fsg->common->buffhds[i];
+                bh = &common->buffhds[i];
                 bh->state = BUF_STATE_EMPTY;
         }
-        fsg->common->next_buffhd_to_fill = &fsg->common->buffhds[0];
-        fsg->common->next_buffhd_to_drain = &fsg->common->buffhds[0];
-        exception_req_tag = fsg->exception_req_tag;
-        new_config = fsg->new_config;
-        old_state = fsg->state;
+        common->next_buffhd_to_fill = &common->buffhds[0];
+        common->next_buffhd_to_drain = &common->buffhds[0];
+        exception_req_tag = common->exception_req_tag;
+        new_config = common->new_config;
+        old_state = common->state;
 
         if (old_state == FSG_STATE_ABORT_BULK_OUT)
-                fsg->state = FSG_STATE_STATUS_PHASE;
+                common->state = FSG_STATE_STATUS_PHASE;
         else {
-                for (i = 0; i < fsg->common->nluns; ++i) {
-                        curlun = &fsg->common->luns[i];
+                for (i = 0; i < common->nluns; ++i) {
+                        curlun = &common->luns[i];
                         curlun->prevent_medium_removal = 0;
                         curlun->sense_data = SS_NO_SENSE;
                         curlun->unit_attention_data = SS_NO_SENSE;
                         curlun->sense_data_info = 0;
                         curlun->info_valid = 0;
                 }
-                fsg->state = FSG_STATE_IDLE;
+                common->state = FSG_STATE_IDLE;
         }
-        spin_unlock_irq(&fsg->lock);
+        spin_unlock_irq(&common->lock);
 
         /* Carry out any extra actions required for the exception */
         switch (old_state) {
         case FSG_STATE_ABORT_BULK_OUT:
-                send_status(fsg);
-                spin_lock_irq(&fsg->lock);
-                if (fsg->state == FSG_STATE_STATUS_PHASE)
-                        fsg->state = FSG_STATE_IDLE;
-                spin_unlock_irq(&fsg->lock);
+                send_status(common);
+                spin_lock_irq(&common->lock);
+                if (common->state == FSG_STATE_STATUS_PHASE)
+                        common->state = FSG_STATE_IDLE;
+                spin_unlock_irq(&common->lock);
                 break;
 
         case FSG_STATE_RESET:
                 /* In case we were forced against our will to halt a
                  * bulk endpoint, clear the halt now.  (The SuperH UDC
                  * requires this.) */
-                if (test_and_clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
-                        usb_ep_clear_halt(fsg->bulk_in);
+                if (!fsg_is_set(common))
+                        break;
+                if (test_and_clear_bit(IGNORE_BULK_OUT,
+                                       &common->fsg->atomic_bitflags))
+                        usb_ep_clear_halt(common->fsg->bulk_in);
 
-                if (fsg->ep0_req_tag == exception_req_tag)
-                        ep0_queue(fsg); /* Complete the status stage */
+                if (common->ep0_req_tag == exception_req_tag)
+                        ep0_queue(common);      /* Complete the status stage */
 
                 /* Technically this should go here, but it would only be
                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
                  * CONFIG_CHANGE cases. */
-                /* for (i = 0; i < fsg->common->nluns; ++i) */
-                /*      fsg->common->luns[i].unit_attention_data = */
+                /* for (i = 0; i < common->nluns; ++i) */
+                /*      common->luns[i].unit_attention_data = */
                 /*              SS_RESET_OCCURRED;  */
                 break;
 
         case FSG_STATE_CONFIG_CHANGE:
-                rc = do_set_config(fsg, new_config);
-                if (fsg->ep0_req_tag != exception_req_tag)
+                rc = do_set_config(common, new_config);
+                if (common->ep0_req_tag != exception_req_tag)
                         break;
-                if (rc != 0)                    /* STALL on errors */
-                        fsg_set_halt(fsg, fsg->ep0);
-                else                            /* Complete the status stage */
-                        ep0_queue(fsg);
+                if (rc != 0) {                  /* STALL on errors */
+                        DBG(common, "ep0 set halt\n");
+                        usb_ep_set_halt(common->ep0);
+                } else {                        /* Complete the status stage */
+                        ep0_queue(common);
+                }
                 break;
 
         case FSG_STATE_EXIT:
         case FSG_STATE_TERMINATED:
-                do_set_config(fsg, 0);                  /* Free resources */
-                spin_lock_irq(&fsg->lock);
-                fsg->state = FSG_STATE_TERMINATED;      /* Stop the thread */
-                spin_unlock_irq(&fsg->lock);
+                do_set_config(common, 0);               /* Free resources */
+                spin_lock_irq(&common->lock);
+                common->state = FSG_STATE_TERMINATED;   /* Stop the thread */
+                spin_unlock_irq(&common->lock);
                 break;
 
         case FSG_STATE_INTERFACE_CHANGE:
@@ -2474,9 +2545,9 @@ static void handle_exception(struct fsg_dev *fsg)
 
 /*-------------------------------------------------------------------------*/
 
-static int fsg_main_thread(void *fsg_)
+static int fsg_main_thread(void *common_)
 {
-        struct fsg_dev          *fsg = fsg_;
+        struct fsg_common       *common = common_;
 
         /* Allow the thread to be killed by a signal, but set the signal mask
          * to block everything but INT, TERM, KILL, and USR1. */
@@ -2494,45 +2565,45 @@ static int fsg_main_thread(void *fsg_)
         set_fs(get_ds());
 
         /* The main loop */
-        while (fsg->state != FSG_STATE_TERMINATED) {
-                if (exception_in_progress(fsg) || signal_pending(current)) {
-                        handle_exception(fsg);
+        while (common->state != FSG_STATE_TERMINATED) {
+                if (exception_in_progress(common) || signal_pending(current)) {
+                        handle_exception(common);
                         continue;
                 }
 
-                if (!fsg->running) {
-                        sleep_thread(fsg);
+                if (!common->running) {
+                        sleep_thread(common);
                         continue;
                 }
 
-                if (get_next_command(fsg))
+                if (get_next_command(common))
                         continue;
 
-                spin_lock_irq(&fsg->lock);
-                if (!exception_in_progress(fsg))
-                        fsg->state = FSG_STATE_DATA_PHASE;
-                spin_unlock_irq(&fsg->lock);
+                spin_lock_irq(&common->lock);
+                if (!exception_in_progress(common))
+                        common->state = FSG_STATE_DATA_PHASE;
+                spin_unlock_irq(&common->lock);
 
-                if (do_scsi_command(fsg) || finish_reply(fsg))
+                if (do_scsi_command(common) || finish_reply(common))
                         continue;
 
-                spin_lock_irq(&fsg->lock);
-                if (!exception_in_progress(fsg))
-                        fsg->state = FSG_STATE_STATUS_PHASE;
-                spin_unlock_irq(&fsg->lock);
+                spin_lock_irq(&common->lock);
+                if (!exception_in_progress(common))
+                        common->state = FSG_STATE_STATUS_PHASE;
+                spin_unlock_irq(&common->lock);
 
-                if (send_status(fsg))
+                if (send_status(common))
                         continue;
 
-                spin_lock_irq(&fsg->lock);
-                if (!exception_in_progress(fsg))
-                        fsg->state = FSG_STATE_IDLE;
-                spin_unlock_irq(&fsg->lock);
+                spin_lock_irq(&common->lock);
+                if (!exception_in_progress(common))
+                        common->state = FSG_STATE_IDLE;
+                spin_unlock_irq(&common->lock);
         }
 
-        spin_lock_irq(&fsg->lock);
-        fsg->thread_task = NULL;
-        spin_unlock_irq(&fsg->lock);
+        spin_lock_irq(&common->lock);
+        common->thread_task = NULL;
+        spin_unlock_irq(&common->lock);
 
         /* XXX */
         /* If we are exiting because of a signal, unregister the
@@ -2541,7 +2612,7 @@ static int fsg_main_thread(void *fsg_)
         /*      usb_gadget_unregister_driver(&fsg_driver); */
 
         /* Let the unbind and cleanup routines know the thread has exited */
-        complete_and_exit(&fsg->thread_notifier, 0);
+        complete_and_exit(&common->thread_notifier, 0);
 }
 
 
@@ -2600,7 +2671,21 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
                 memset(common, 0, sizeof common);
                 common->free_storage_on_release = 0;
         }
+
         common->gadget = gadget;
+        common->ep0 = gadget->ep0;
+        common->ep0req = cdev->req;
+
+        /* Maybe allocate device-global string IDs, and patch descriptors */
+        if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
+                rc = usb_string_id(cdev);
+                if (rc < 0) {
+                        kfree(common);
+                        return ERR_PTR(rc);
+                }
+                fsg_strings[FSG_STRING_INTERFACE].id = rc;
+                fsg_intf_desc.iInterface = rc;
+        }
 
         /* Create the LUNs, open their backing files, and register the
          * LUN devices in sysfs. */
@@ -2697,11 +2782,23 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
          * disable stalls.
          */
         common->can_stall = cfg->can_stall &&
-                !(gadget_is_sh(fsg->gadget) || gadget_is_at91(fsg->gadget));
+                !(gadget_is_sh(common->gadget) ||
+                  gadget_is_at91(common->gadget));
 
 
-        common->thread_name = OR(cfg->thread_name, "file-storage");
+        spin_lock_init(&common->lock);
         kref_init(&common->ref);
+
+
+        /* Tell the thread to start working */
+        common->thread_task =
+                kthread_create(fsg_main_thread, common,
+                               OR(cfg->thread_name, "file-storage"));
+        if (IS_ERR(common->thread_task)) {
+                rc = PTR_ERR(common->thread_task);
+                goto error_release;
+        }
+        init_completion(&common->thread_notifier);
 #undef OR
 
 
@@ -2731,15 +2828,21 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
         }
         kfree(pathbuf);
 
+        DBG(common, "I/O thread pid: %d\n", task_pid_nr(common->thread_task));
+
+        wake_up_process(common->thread_task);
+
         return common;
 
 
 error_luns:
         common->nluns = i + 1;
 error_release:
+        common->state = FSG_STATE_TERMINATED;   /* The thread is dead */
         /* Call fsg_common_release() directly, ref might be not
          * initialised */
         fsg_common_release(&common->ref);
+        complete(&common->thread_notifier);
         return ERR_PTR(rc);
 }
 
@@ -2751,6 +2854,15 @@ static void fsg_common_release(struct kref *ref)
         unsigned i = common->nluns;
         struct fsg_lun *lun = common->luns;
 
+        /* If the thread isn't already dead, tell it to exit now */
+        if (common->state != FSG_STATE_TERMINATED) {
+                raise_exception(common, FSG_STATE_EXIT);
+                wait_for_completion(&common->thread_notifier);
+
+                /* The cleanup routine waits for this completion also */
+                complete(&common->thread_notifier);
+        }
+
         /* Beware tempting for -> do-while optimization: when in error
          * recovery nluns may be zero. */
 
@@ -2775,17 +2887,6 @@ static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
         struct fsg_dev          *fsg = fsg_from_func(f);
 
         DBG(fsg, "unbind\n");
-        clear_bit(REGISTERED, &fsg->atomic_bitflags);
-
-        /* If the thread isn't already dead, tell it to exit now */
-        if (fsg->state != FSG_STATE_TERMINATED) {
-                raise_exception(fsg, FSG_STATE_EXIT);
-                wait_for_completion(&fsg->thread_notifier);
-
-                /* The cleanup routine waits for this completion also */
-                complete(&fsg->thread_notifier);
-        }
-
         fsg_common_put(fsg->common);
         kfree(fsg);
 }
@@ -2800,8 +2901,6 @@ static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
         struct usb_ep           *ep;
 
         fsg->gadget = gadget;
-        fsg->ep0 = gadget->ep0;
-        fsg->ep0req = c->cdev->req;
 
         /* New interface */
         i = usb_interface_id(c, f);
@@ -2814,13 +2913,13 @@ static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
         if (!ep)
                 goto autoconf_fail;
-        ep->driver_data = fsg;          /* claim the endpoint */
+        ep->driver_data = fsg->common;  /* claim the endpoint */
         fsg->bulk_in = ep;
 
         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
         if (!ep)
                 goto autoconf_fail;
-        ep->driver_data = fsg;          /* claim the endpoint */
+        ep->driver_data = fsg->common;  /* claim the endpoint */
         fsg->bulk_out = ep;
 
         if (gadget_is_dualspeed(gadget)) {
@@ -2832,40 +2931,12 @@ static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
                 f->hs_descriptors = fsg_hs_function;
         }
 
-
-        /* maybe allocate device-global string IDs, and patch descriptors */
-        if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
-                i = usb_string_id(c->cdev);
-                if (i < 0)
-                        return i;
-                fsg_strings[FSG_STRING_INTERFACE].id = i;
-                fsg_intf_desc.iInterface = i;
-        }
-
-
-        fsg->thread_task = kthread_create(fsg_main_thread, fsg,
-                                          fsg->common->thread_name);
-        if (IS_ERR(fsg->thread_task)) {
-                rc = PTR_ERR(fsg->thread_task);
-                goto out;
-        }
-
-        DBG(fsg, "I/O thread pid: %d\n", task_pid_nr(fsg->thread_task));
-
-        set_bit(REGISTERED, &fsg->atomic_bitflags);
-
-        /* Tell the thread to start working */
-        wake_up_process(fsg->thread_task);
         return 0;
 
 autoconf_fail:
         ERROR(fsg, "unable to autoconfigure all endpoints\n");
         rc = -ENOTSUPP;
-
-out:
-        fsg->state = FSG_STATE_TERMINATED;      /* The thread is dead */
         fsg_unbind(c, f);
-        complete(&fsg->thread_notifier);
         return rc;
 }
 
@@ -2888,10 +2959,6 @@ static int fsg_add(struct usb_composite_dev *cdev,
         if (unlikely(!fsg))
                 return -ENOMEM;
 
-        spin_lock_init(&fsg->lock);
-        init_completion(&fsg->thread_notifier);
-
-        fsg->cdev                 = cdev;
         fsg->function.name        = FSG_DRIVER_DESC;
         fsg->function.strings     = fsg_strings_array;
         fsg->function.descriptors = fsg_fs_function;
@@ -2907,7 +2974,6 @@ static int fsg_add(struct usb_composite_dev *cdev,
          * from this function.  So instead of incrementing counter now
          * and decrement in error recovery we increment it only when
          * call to usb_add_function() was successful. */
-        fsg->can_stall = common->can_stall;
 
         rc = usb_add_function(c, &fsg->function);