drivers/usb/gadget/function/f_mass_storage.c

   1 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
   2 /*
   3  * f_mass_storage.c -- Mass Storage USB Composite Function
   4  *
   5  * Copyright (C) 2003-2008 Alan Stern
   6  * Copyright (C) 2009 Samsung Electronics
   7  *                    Author: Michal Nazarewicz <mina86@mina86.com>
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions, and the following disclaimer,
  15  *    without modification.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. The names of the above-listed copyright holders may not be used
  20  *    to endorse or promote products derived from this software without
  21  *    specific prior written permission.
  22  *
  23  * ALTERNATIVELY, this software may be distributed under the terms of the
  24  * GNU General Public License ("GPL") as published by the Free Software
  25  * Foundation, either version 2 of that License or (at your option) any
  26  * later version.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  29  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  30  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  31  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  32  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  33  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  34  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  35  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  36  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  37  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  38  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  39  */
  40
  41 /*
  42  * The Mass Storage Function acts as a USB Mass Storage device,
  43  * appearing to the host as a disk drive or as a CD-ROM drive.  In
  44  * addition to providing an example of a genuinely useful composite
  45  * function for a USB device, it also illustrates a technique of
  46  * double-buffering for increased throughput.
  47  *
  48  * For more information about MSF and in particular its module
  49  * parameters and sysfs interface read the
  50  * <Documentation/usb/mass-storage.txt> file.
  51  */
  52
  53 /*
  54  * MSF is configured by specifying a fsg_config structure.  It has the
  55  * following fields:
  56  *
  57  *      nluns           Number of LUNs function have (anywhere from 1
  58  *                              to FSG_MAX_LUNS).
  59  *      luns            An array of LUN configuration values.  This
  60  *                              should be filled for each LUN that
  61  *                              function will include (ie. for "nluns"
  62  *                              LUNs).  Each element of the array has
  63  *                              the following fields:
  64  *      ->filename      The path to the backing file for the LUN.
  65  *                              Required if LUN is not marked as
  66  *                              removable.
  67  *      ->ro            Flag specifying access to the LUN shall be
  68  *                              read-only.  This is implied if CD-ROM
  69  *                              emulation is enabled as well as when
  70  *                              it was impossible to open "filename"
  71  *                              in R/W mode.
  72  *      ->removable     Flag specifying that LUN shall be indicated as
  73  *                              being removable.
  74  *      ->cdrom         Flag specifying that LUN shall be reported as
  75  *                              being a CD-ROM.
  76  *      ->nofua         Flag specifying that FUA flag in SCSI WRITE(10,12)
  77  *                              commands for this LUN shall be ignored.
  78  *
  79  *      vendor_name
  80  *      product_name
  81  *      release         Information used as a reply to INQUIRY
  82  *                              request.  To use default set to NULL,
  83  *                              NULL, 0xffff respectively.  The first
  84  *                              field should be 8 and the second 16
  85  *                              characters or less.
  86  *
  87  *      can_stall       Set to permit function to halt bulk endpoints.
  88  *                              Disabled on some USB devices known not
  89  *                              to work correctly.  You should set it
  90  *                              to true.
  91  *
  92  * If "removable" is not set for a LUN then a backing file must be
  93  * specified.  If it is set, then NULL filename means the LUN's medium
  94  * is not loaded (an empty string as "filename" in the fsg_config
  95  * structure causes error).  The CD-ROM emulation includes a single
  96  * data track and no audio tracks; hence there need be only one
  97  * backing file per LUN.
  98  *
  99  * This function is heavily based on "File-backed Storage Gadget" by
 100  * Alan Stern which in turn is heavily based on "Gadget Zero" by David
 101  * Brownell.  The driver's SCSI command interface was based on the
 102  * "Information technology - Small Computer System Interface - 2"
 103  * document from X3T9.2 Project 375D, Revision 10L, 7-SEP-93,
 104  * available at <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.
 105  * The single exception is opcode 0x23 (READ FORMAT CAPACITIES), which
 106  * was based on the "Universal Serial Bus Mass Storage Class UFI
 107  * Command Specification" document, Revision 1.0, December 14, 1998,
 108  * available at
 109  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
 110  */
 111
 112 /*
 113  *                              Driver Design
 114  *
 115  * The MSF is fairly straightforward.  There is a main kernel
 116  * thread that handles most of the work.  Interrupt routines field
 117  * callbacks from the controller driver: bulk- and interrupt-request
 118  * completion notifications, endpoint-0 events, and disconnect events.
 119  * Completion events are passed to the main thread by wakeup calls.  Many
 120  * ep0 requests are handled at interrupt time, but SetInterface,
 121  * SetConfiguration, and device reset requests are forwarded to the
 122  * thread in the form of "exceptions" using SIGUSR1 signals (since they
 123  * should interrupt any ongoing file I/O operations).
 124  *
 125  * The thread's main routine implements the standard command/data/status
 126  * parts of a SCSI interaction.  It and its subroutines are full of tests
 127  * for pending signals/exceptions -- all this polling is necessary since
 128  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
 129  * indication that the driver really wants to be running in userspace.)
 130  * An important point is that so long as the thread is alive it keeps an
 131  * open reference to the backing file.  This will prevent unmounting
 132  * the backing file's underlying filesystem and could cause problems
 133  * during system shutdown, for example.  To prevent such problems, the
 134  * thread catches INT, TERM, and KILL signals and converts them into
 135  * an EXIT exception.
 136  *
 137  * In normal operation the main thread is started during the gadget's
 138  * fsg_bind() callback and stopped during fsg_unbind().  But it can
 139  * also exit when it receives a signal, and there's no point leaving
 140  * the gadget running when the thread is dead.  As of this moment, MSF
 141  * provides no way to deregister the gadget when thread dies -- maybe
 142  * a callback functions is needed.
 143  *
 144  * To provide maximum throughput, the driver uses a circular pipeline of
 145  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
 146  * arbitrarily long; in practice the benefits don't justify having more
 147  * than 2 stages (i.e., double buffering).  But it helps to think of the
 148  * pipeline as being a long one.  Each buffer head contains a bulk-in and
 149  * a bulk-out request pointer (since the buffer can be used for both
 150  * output and input -- directions always are given from the host's
 151  * point of view) as well as a pointer to the buffer and various state
 152  * variables.
 153  *
 154  * Use of the pipeline follows a simple protocol.  There is a variable
 155  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
 156  * At any time that buffer head may still be in use from an earlier
 157  * request, so each buffer head has a state variable indicating whether
 158  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
 159  * buffer head to be EMPTY, filling the buffer either by file I/O or by
 160  * USB I/O (during which the buffer head is BUSY), and marking the buffer
 161  * head FULL when the I/O is complete.  Then the buffer will be emptied
 162  * (again possibly by USB I/O, during which it is marked BUSY) and
 163  * finally marked EMPTY again (possibly by a completion routine).
 164  *
 165  * A module parameter tells the driver to avoid stalling the bulk
 166  * endpoints wherever the transport specification allows.  This is
 167  * necessary for some UDCs like the SuperH, which cannot reliably clear a
 168  * halt on a bulk endpoint.  However, under certain circumstances the
 169  * Bulk-only specification requires a stall.  In such cases the driver
 170  * will halt the endpoint and set a flag indicating that it should clear
 171  * the halt in software during the next device reset.  Hopefully this
 172  * will permit everything to work correctly.  Furthermore, although the
 173  * specification allows the bulk-out endpoint to halt when the host sends
 174  * too much data, implementing this would cause an unavoidable race.
 175  * The driver will always use the "no-stall" approach for OUT transfers.
 176  *
 177  * One subtle point concerns sending status-stage responses for ep0
 178  * requests.  Some of these requests, such as device reset, can involve
 179  * interrupting an ongoing file I/O operation, which might take an
 180  * arbitrarily long time.  During that delay the host might give up on
 181  * the original ep0 request and issue a new one.  When that happens the
 182  * driver should not notify the host about completion of the original
 183  * request, as the host will no longer be waiting for it.  So the driver
 184  * assigns to each ep0 request a unique tag, and it keeps track of the
 185  * tag value of the request associated with a long-running exception
 186  * (device-reset, interface-change, or configuration-change).  When the
 187  * exception handler is finished, the status-stage response is submitted
 188  * only if the current ep0 request tag is equal to the exception request
 189  * tag.  Thus only the most recently received ep0 request will get a
 190  * status-stage response.
 191  *
 192  * Warning: This driver source file is too long.  It ought to be split up
 193  * into a header file plus about 3 separate .c files, to handle the details
 194  * of the Gadget, USB Mass Storage, and SCSI protocols.
 195  */
 196
 197
 198 /* #define VERBOSE_DEBUG */
 199 /* #define DUMP_MSGS */
 200
 201 #include <linux/blkdev.h>
 202 #include <linux/completion.h>
 203 #include <linux/dcache.h>
 204 #include <linux/delay.h>
 205 #include <linux/device.h>
 206 #include <linux/fcntl.h>
 207 #include <linux/file.h>
 208 #include <linux/fs.h>
 209 #include <linux/kthread.h>
 210 #include <linux/sched/signal.h>
 211 #include <linux/limits.h>
 212 #include <linux/rwsem.h>
 213 #include <linux/slab.h>
 214 #include <linux/spinlock.h>
 215 #include <linux/string.h>
 216 #include <linux/freezer.h>
 217 #include <linux/module.h>
 218 #include <linux/uaccess.h>
 219
 220 #include <linux/usb/ch9.h>
 221 #include <linux/usb/gadget.h>
 222 #include <linux/usb/composite.h>
 223
 224 #include <linux/nospec.h>
 225
 226 #include "configfs.h"
 227
 228
 229 /*------------------------------------------------------------------------*/
 230
 231 #define FSG_DRIVER_DESC         "Mass Storage Function"
 232 #define FSG_DRIVER_VERSION      "2009/09/11"
 233
 234 static const char fsg_string_interface[] = "Mass Storage";
 235
 236 #include "storage_common.h"
 237 #include "f_mass_storage.h"
 238
 239 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
 240 static struct usb_string                fsg_strings[] = {
 241         {FSG_STRING_INTERFACE,          fsg_string_interface},
 242         {}
 243 };
 244
 245 static struct usb_gadget_strings        fsg_stringtab = {
 246         .language       = 0x0409,               /* en-us */
 247         .strings        = fsg_strings,
 248 };
 249
 250 static struct usb_gadget_strings *fsg_strings_array[] = {
 251         &fsg_stringtab,
 252         NULL,
 253 };
 254
 255 /*-------------------------------------------------------------------------*/
 256
 257 struct fsg_dev;
 258 struct fsg_common;
 259
 260 /* Data shared by all the FSG instances. */
 261 struct fsg_common {
 262         struct usb_gadget       *gadget;
 263         struct usb_composite_dev *cdev;
 264         struct fsg_dev          *fsg, *new_fsg;
 265         wait_queue_head_t       io_wait;
 266         wait_queue_head_t       fsg_wait;
 267
 268         /* filesem protects: backing files in use */
 269         struct rw_semaphore     filesem;
 270
 271         /* lock protects: state and thread_task */
 272         spinlock_t              lock;
 273
 274         struct usb_ep           *ep0;           /* Copy of gadget->ep0 */
 275         struct usb_request      *ep0req;        /* Copy of cdev->req */
 276         unsigned int            ep0_req_tag;
 277
 278         struct fsg_buffhd       *next_buffhd_to_fill;
 279         struct fsg_buffhd       *next_buffhd_to_drain;
 280         struct fsg_buffhd       *buffhds;
 281         unsigned int            fsg_num_buffers;
 282
 283         int                     cmnd_size;
 284         u8                      cmnd[MAX_COMMAND_SIZE];
 285
 286         unsigned int            lun;
 287         struct fsg_lun          *luns[FSG_MAX_LUNS];
 288         struct fsg_lun          *curlun;
 289
 290         unsigned int            bulk_out_maxpacket;
 291         enum fsg_state          state;          /* For exception handling */
 292         unsigned int            exception_req_tag;
 293
 294         enum data_direction     data_dir;
 295         u32                     data_size;
 296         u32                     data_size_from_cmnd;
 297         u32                     tag;
 298         u32                     residue;
 299         u32                     usb_amount_left;
 300
 301         unsigned int            can_stall:1;
 302         unsigned int            free_storage_on_release:1;
 303         unsigned int            phase_error:1;
 304         unsigned int            short_packet_received:1;
 305         unsigned int            bad_lun_okay:1;
 306         unsigned int            running:1;
 307         unsigned int            sysfs:1;
 308
 309         struct completion       thread_notifier;
 310         struct task_struct      *thread_task;
 311
 312         /* Gadget's private data. */
 313         void                    *private_data;
 314
 315         char inquiry_string[INQUIRY_STRING_LEN];
 316 };
 317
 318 struct fsg_dev {
 319         struct usb_function     function;
 320         struct usb_gadget       *gadget;        /* Copy of cdev->gadget */
 321         struct fsg_common       *common;
 322
 323         u16                     interface_number;
 324
 325         unsigned int            bulk_in_enabled:1;
 326         unsigned int            bulk_out_enabled:1;
 327
 328         unsigned long           atomic_bitflags;
 329 #define IGNORE_BULK_OUT         0
 330
 331         struct usb_ep           *bulk_in;
 332         struct usb_ep           *bulk_out;
 333 };
 334
 335 static inline int __fsg_is_set(struct fsg_common *common,
 336                                const char *func, unsigned line)
 337 {
 338         if (common->fsg)
 339                 return 1;
 340         ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
 341         WARN_ON(1);
 342         return 0;
 343 }
 344
 345 #define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
 346
 347 static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
 348 {
 349         return container_of(f, struct fsg_dev, function);
 350 }
 351
 352 typedef void (*fsg_routine_t)(struct fsg_dev *);
 353
 354 static int exception_in_progress(struct fsg_common *common)
 355 {
 356         return common->state > FSG_STATE_NORMAL;
 357 }
 358
 359 /* Make bulk-out requests be divisible by the maxpacket size */
 360 static void set_bulk_out_req_length(struct fsg_common *common,
 361                                     struct fsg_buffhd *bh, unsigned int length)
 362 {
 363         unsigned int    rem;
 364
 365         bh->bulk_out_intended_length = length;
 366         rem = length % common->bulk_out_maxpacket;
 367         if (rem > 0)
 368                 length += common->bulk_out_maxpacket - rem;
 369         bh->outreq->length = length;
 370 }
 371
 372
 373 /*-------------------------------------------------------------------------*/
 374
 375 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
 376 {
 377         const char      *name;
 378
 379         if (ep == fsg->bulk_in)
 380                 name = "bulk-in";
 381         else if (ep == fsg->bulk_out)
 382                 name = "bulk-out";
 383         else
 384                 name = ep->name;
 385         DBG(fsg, "%s set halt\n", name);
 386         return usb_ep_set_halt(ep);
 387 }
 388
 389
 390 /*-------------------------------------------------------------------------*/
 391
 392 /* These routines may be called in process context or in_irq */
 393
 394 static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
 395 {
 396         unsigned long           flags;
 397
 398         /*
 399          * Do nothing if a higher-priority exception is already in progress.
 400          * If a lower-or-equal priority exception is in progress, preempt it
 401          * and notify the main thread by sending it a signal.
 402          */
 403         spin_lock_irqsave(&common->lock, flags);
 404         if (common->state <= new_state) {
 405                 common->exception_req_tag = common->ep0_req_tag;
 406                 common->state = new_state;
 407                 if (common->thread_task)
 408                         send_sig_info(SIGUSR1, SEND_SIG_PRIV,
 409                                       common->thread_task);
 410         }
 411         spin_unlock_irqrestore(&common->lock, flags);
 412 }
 413
 414
 415 /*-------------------------------------------------------------------------*/
 416
 417 static int ep0_queue(struct fsg_common *common)
 418 {
 419         int     rc;
 420
 421         rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
 422         common->ep0->driver_data = common;
 423         if (rc != 0 && rc != -ESHUTDOWN) {
 424                 /* We can't do much more than wait for a reset */
 425                 WARNING(common, "error in submission: %s --> %d\n",
 426                         common->ep0->name, rc);
 427         }
 428         return rc;
 429 }
 430
 431
 432 /*-------------------------------------------------------------------------*/
 433
 434 /* Completion handlers. These always run in_irq. */
 435
 436 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
 437 {
 438         struct fsg_common       *common = ep->driver_data;
 439         struct fsg_buffhd       *bh = req->context;
 440
 441         if (req->status || req->actual != req->length)
 442                 DBG(common, "%s --> %d, %u/%u\n", __func__,
 443                     req->status, req->actual, req->length);
 444         if (req->status == -ECONNRESET)         /* Request was cancelled */
 445                 usb_ep_fifo_flush(ep);
 446
 447         /* Synchronize with the smp_load_acquire() in sleep_thread() */
 448         smp_store_release(&bh->state, BUF_STATE_EMPTY);
 449         wake_up(&common->io_wait);
 450 }
 451
 452 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
 453 {
 454         struct fsg_common       *common = ep->driver_data;
 455         struct fsg_buffhd       *bh = req->context;
 456
 457         dump_msg(common, "bulk-out", req->buf, req->actual);
 458         if (req->status || req->actual != bh->bulk_out_intended_length)
 459                 DBG(common, "%s --> %d, %u/%u\n", __func__,
 460                     req->status, req->actual, bh->bulk_out_intended_length);
 461         if (req->status == -ECONNRESET)         /* Request was cancelled */
 462                 usb_ep_fifo_flush(ep);
 463
 464         /* Synchronize with the smp_load_acquire() in sleep_thread() */
 465         smp_store_release(&bh->state, BUF_STATE_FULL);
 466         wake_up(&common->io_wait);
 467 }
 468
 469 static int _fsg_common_get_max_lun(struct fsg_common *common)
 470 {
 471         int i = ARRAY_SIZE(common->luns) - 1;
 472
 473         while (i >= 0 && !common->luns[i])
 474                 --i;
 475
 476         return i;
 477 }
 478
 479 static int fsg_setup(struct usb_function *f,
 480                      const struct usb_ctrlrequest *ctrl)
 481 {
 482         struct fsg_dev          *fsg = fsg_from_func(f);
 483         struct usb_request      *req = fsg->common->ep0req;
 484         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 485         u16                     w_value = le16_to_cpu(ctrl->wValue);
 486         u16                     w_length = le16_to_cpu(ctrl->wLength);
 487
 488         if (!fsg_is_set(fsg->common))
 489                 return -EOPNOTSUPP;
 490
 491         ++fsg->common->ep0_req_tag;     /* Record arrival of a new request */
 492         req->context = NULL;
 493         req->length = 0;
 494         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
 495
 496         switch (ctrl->bRequest) {
 497
 498         case US_BULK_RESET_REQUEST:
 499                 if (ctrl->bRequestType !=
 500                     (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 501                         break;
 502                 if (w_index != fsg->interface_number || w_value != 0 ||
 503                                 w_length != 0)
 504                         return -EDOM;
 505
 506                 /*
 507                  * Raise an exception to stop the current operation
 508                  * and reinitialize our state.
 509                  */
 510                 DBG(fsg, "bulk reset request\n");
 511                 raise_exception(fsg->common, FSG_STATE_PROTOCOL_RESET);
 512                 return USB_GADGET_DELAYED_STATUS;
 513
 514         case US_BULK_GET_MAX_LUN:
 515                 if (ctrl->bRequestType !=
 516                     (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 517                         break;
 518                 if (w_index != fsg->interface_number || w_value != 0 ||
 519                                 w_length != 1)
 520                         return -EDOM;
 521                 VDBG(fsg, "get max LUN\n");
 522                 *(u8 *)req->buf = _fsg_common_get_max_lun(fsg->common);
 523
 524                 /* Respond with data/status */
 525                 req->length = min((u16)1, w_length);
 526                 return ep0_queue(fsg->common);
 527         }
 528
 529         VDBG(fsg,
 530              "unknown class-specific control req %02x.%02x v%04x i%04x l%u\n",
 531              ctrl->bRequestType, ctrl->bRequest,
 532              le16_to_cpu(ctrl->wValue), w_index, w_length);
 533         return -EOPNOTSUPP;
 534 }
 535
 536
 537 /*-------------------------------------------------------------------------*/
 538
 539 /* All the following routines run in process context */
 540
 541 /* Use this for bulk or interrupt transfers, not ep0 */
 542 static int start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
 543                            struct usb_request *req)
 544 {
 545         int     rc;
 546
 547         if (ep == fsg->bulk_in)
 548                 dump_msg(fsg, "bulk-in", req->buf, req->length);
 549
 550         rc = usb_ep_queue(ep, req, GFP_KERNEL);
 551         if (rc) {
 552
 553                 /* We can't do much more than wait for a reset */
 554                 req->status = rc;
 555
 556                 /*
 557                  * Note: currently the net2280 driver fails zero-length
 558                  * submissions if DMA is enabled.
 559                  */
 560                 if (rc != -ESHUTDOWN &&
 561                                 !(rc == -EOPNOTSUPP && req->length == 0))
 562                         WARNING(fsg, "error in submission: %s --> %d\n",
 563                                         ep->name, rc);
 564         }
 565         return rc;
 566 }
 567
 568 static bool start_in_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
 569 {
 570         if (!fsg_is_set(common))
 571                 return false;
 572         bh->state = BUF_STATE_SENDING;
 573         if (start_transfer(common->fsg, common->fsg->bulk_in, bh->inreq))
 574                 bh->state = BUF_STATE_EMPTY;
 575         return true;
 576 }
 577
 578 static bool start_out_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
 579 {
 580         if (!fsg_is_set(common))
 581                 return false;
 582         bh->state = BUF_STATE_RECEIVING;
 583         if (start_transfer(common->fsg, common->fsg->bulk_out, bh->outreq))
 584                 bh->state = BUF_STATE_FULL;
 585         return true;
 586 }
 587
 588 static int sleep_thread(struct fsg_common *common, bool can_freeze,
 589                 struct fsg_buffhd *bh)
 590 {
 591         int     rc;
 592
 593         /* Wait until a signal arrives or bh is no longer busy */
 594         if (can_freeze)
 595                 /*
 596                  * synchronize with the smp_store_release(&bh->state) in
 597                  * bulk_in_complete() or bulk_out_complete()
 598                  */
 599                 rc = wait_event_freezable(common->io_wait,
 600                                 bh && smp_load_acquire(&bh->state) >=
 601                                         BUF_STATE_EMPTY);
 602         else
 603                 rc = wait_event_interruptible(common->io_wait,
 604                                 bh && smp_load_acquire(&bh->state) >=
 605                                         BUF_STATE_EMPTY);
 606         return rc ? -EINTR : 0;
 607 }
 608
 609
 610 /*-------------------------------------------------------------------------*/
 611
 612 static int do_read(struct fsg_common *common)
 613 {
 614         struct fsg_lun          *curlun = common->curlun;
 615         u32                     lba;
 616         struct fsg_buffhd       *bh;
 617         int                     rc;
 618         u32                     amount_left;
 619         loff_t                  file_offset, file_offset_tmp;
 620         unsigned int            amount;
 621         ssize_t                 nread;
 622
 623         /*
 624          * Get the starting Logical Block Address and check that it's
 625          * not too big.
 626          */
 627         if (common->cmnd[0] == READ_6)
 628                 lba = get_unaligned_be24(&common->cmnd[1]);
 629         else {
 630                 lba = get_unaligned_be32(&common->cmnd[2]);
 631
 632                 /*
 633                  * We allow DPO (Disable Page Out = don't save data in the
 634                  * cache) and FUA (Force Unit Access = don't read from the
 635                  * cache), but we don't implement them.
 636                  */
 637                 if ((common->cmnd[1] & ~0x18) != 0) {
 638                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
 639                         return -EINVAL;
 640                 }
 641         }
 642         if (lba >= curlun->num_sectors) {
 643                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 644                 return -EINVAL;
 645         }
 646         file_offset = ((loff_t) lba) << curlun->blkbits;
 647
 648         /* Carry out the file reads */
 649         amount_left = common->data_size_from_cmnd;
 650         if (unlikely(amount_left == 0))
 651                 return -EIO;            /* No default reply */
 652
 653         for (;;) {
 654                 /*
 655                  * Figure out how much we need to read:
 656                  * Try to read the remaining amount.
 657                  * But don't read more than the buffer size.
 658                  * And don't try to read past the end of the file.
 659                  */
 660                 amount = min(amount_left, FSG_BUFLEN);
 661                 amount = min((loff_t)amount,
 662                              curlun->file_length - file_offset);
 663
 664                 /* Wait for the next buffer to become available */
 665                 bh = common->next_buffhd_to_fill;
 666                 rc = sleep_thread(common, false, bh);
 667                 if (rc)
 668                         return rc;
 669
 670                 /*
 671                  * If we were asked to read past the end of file,
 672                  * end with an empty buffer.
 673                  */
 674                 if (amount == 0) {
 675                         curlun->sense_data =
 676                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 677                         curlun->sense_data_info =
 678                                         file_offset >> curlun->blkbits;
 679                         curlun->info_valid = 1;
 680                         bh->inreq->length = 0;
 681                         bh->state = BUF_STATE_FULL;
 682                         break;
 683                 }
 684
 685                 /* Perform the read */
 686                 file_offset_tmp = file_offset;
 687                 nread = kernel_read(curlun->filp, bh->buf, amount,
 688                                 &file_offset_tmp);
 689                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
 690                       (unsigned long long)file_offset, (int)nread);
 691                 if (signal_pending(current))
 692                         return -EINTR;
 693
 694                 if (nread < 0) {
 695                         LDBG(curlun, "error in file read: %d\n", (int)nread);
 696                         nread = 0;
 697                 } else if (nread < amount) {
 698                         LDBG(curlun, "partial file read: %d/%u\n",
 699                              (int)nread, amount);
 700                         nread = round_down(nread, curlun->blksize);
 701                 }
 702                 file_offset  += nread;
 703                 amount_left  -= nread;
 704                 common->residue -= nread;
 705
 706                 /*
 707                  * Except at the end of the transfer, nread will be
 708                  * equal to the buffer size, which is divisible by the
 709                  * bulk-in maxpacket size.
 710                  */
 711                 bh->inreq->length = nread;
 712                 bh->state = BUF_STATE_FULL;
 713
 714                 /* If an error occurred, report it and its position */
 715                 if (nread < amount) {
 716                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
 717                         curlun->sense_data_info =
 718                                         file_offset >> curlun->blkbits;
 719                         curlun->info_valid = 1;
 720                         break;
 721                 }
 722
 723                 if (amount_left == 0)
 724                         break;          /* No more left to read */
 725
 726                 /* Send this buffer and go read some more */
 727                 bh->inreq->zero = 0;
 728                 if (!start_in_transfer(common, bh))
 729                         /* Don't know what to do if common->fsg is NULL */
 730                         return -EIO;
 731                 common->next_buffhd_to_fill = bh->next;
 732         }
 733
 734         return -EIO;            /* No default reply */
 735 }
 736
 737
 738 /*-------------------------------------------------------------------------*/
 739
 740 static int do_write(struct fsg_common *common)
 741 {
 742         struct fsg_lun          *curlun = common->curlun;
 743         u32                     lba;
 744         struct fsg_buffhd       *bh;
 745         int                     get_some_more;
 746         u32                     amount_left_to_req, amount_left_to_write;
 747         loff_t                  usb_offset, file_offset, file_offset_tmp;
 748         unsigned int            amount;
 749         ssize_t                 nwritten;
 750         int                     rc;
 751
 752         if (curlun->ro) {
 753                 curlun->sense_data = SS_WRITE_PROTECTED;
 754                 return -EINVAL;
 755         }
 756         spin_lock(&curlun->filp->f_lock);
 757         curlun->filp->f_flags &= ~O_SYNC;       /* Default is not to wait */
 758         spin_unlock(&curlun->filp->f_lock);
 759
 760         /*
 761          * Get the starting Logical Block Address and check that it's
 762          * not too big
 763          */
 764         if (common->cmnd[0] == WRITE_6)
 765                 lba = get_unaligned_be24(&common->cmnd[1]);
 766         else {
 767                 lba = get_unaligned_be32(&common->cmnd[2]);
 768
 769                 /*
 770                  * We allow DPO (Disable Page Out = don't save data in the
 771                  * cache) and FUA (Force Unit Access = write directly to the
 772                  * medium).  We don't implement DPO; we implement FUA by
 773                  * performing synchronous output.
 774                  */
 775                 if (common->cmnd[1] & ~0x18) {
 776                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
 777                         return -EINVAL;
 778                 }
 779                 if (!curlun->nofua && (common->cmnd[1] & 0x08)) { /* FUA */
 780                         spin_lock(&curlun->filp->f_lock);
 781                         curlun->filp->f_flags |= O_SYNC;
 782                         spin_unlock(&curlun->filp->f_lock);
 783                 }
 784         }
 785         if (lba >= curlun->num_sectors) {
 786                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 787                 return -EINVAL;
 788         }
 789
 790         /* Carry out the file writes */
 791         get_some_more = 1;
 792         file_offset = usb_offset = ((loff_t) lba) << curlun->blkbits;
 793         amount_left_to_req = common->data_size_from_cmnd;
 794         amount_left_to_write = common->data_size_from_cmnd;
 795
 796         while (amount_left_to_write > 0) {
 797
 798                 /* Queue a request for more data from the host */
 799                 bh = common->next_buffhd_to_fill;
 800                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
 801
 802                         /*
 803                          * Figure out how much we want to get:
 804                          * Try to get the remaining amount,
 805                          * but not more than the buffer size.
 806                          */
 807                         amount = min(amount_left_to_req, FSG_BUFLEN);
 808
 809                         /* Beyond the end of the backing file? */
 810                         if (usb_offset >= curlun->file_length) {
 811                                 get_some_more = 0;
 812                                 curlun->sense_data =
 813                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 814                                 curlun->sense_data_info =
 815                                         usb_offset >> curlun->blkbits;
 816                                 curlun->info_valid = 1;
 817                                 continue;
 818                         }
 819
 820                         /* Get the next buffer */
 821                         usb_offset += amount;
 822                         common->usb_amount_left -= amount;
 823                         amount_left_to_req -= amount;
 824                         if (amount_left_to_req == 0)
 825                                 get_some_more = 0;
 826
 827                         /*
 828                          * Except at the end of the transfer, amount will be
 829                          * equal to the buffer size, which is divisible by
 830                          * the bulk-out maxpacket size.
 831                          */
 832                         set_bulk_out_req_length(common, bh, amount);
 833                         if (!start_out_transfer(common, bh))
 834                                 /* Dunno what to do if common->fsg is NULL */
 835                                 return -EIO;
 836                         common->next_buffhd_to_fill = bh->next;
 837                         continue;
 838                 }
 839
 840                 /* Write the received data to the backing file */
 841                 bh = common->next_buffhd_to_drain;
 842                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
 843                         break;                  /* We stopped early */
 844
 845                 /* Wait for the data to be received */
 846                 rc = sleep_thread(common, false, bh);
 847                 if (rc)
 848                         return rc;
 849
 850                 common->next_buffhd_to_drain = bh->next;
 851                 bh->state = BUF_STATE_EMPTY;
 852
 853                 /* Did something go wrong with the transfer? */
 854                 if (bh->outreq->status != 0) {
 855                         curlun->sense_data = SS_COMMUNICATION_FAILURE;
 856                         curlun->sense_data_info =
 857                                         file_offset >> curlun->blkbits;
 858                         curlun->info_valid = 1;
 859                         break;
 860                 }
 861
 862                 amount = bh->outreq->actual;
 863                 if (curlun->file_length - file_offset < amount) {
 864                         LERROR(curlun, "write %u @ %llu beyond end %llu\n",
 865                                        amount, (unsigned long long)file_offset,
 866                                        (unsigned long long)curlun->file_length);
 867                         amount = curlun->file_length - file_offset;
 868                 }
 869
 870                 /*
 871                  * Don't accept excess data.  The spec doesn't say
 872                  * what to do in this case.  We'll ignore the error.
 873                  */
 874                 amount = min(amount, bh->bulk_out_intended_length);
 875
 876                 /* Don't write a partial block */
 877                 amount = round_down(amount, curlun->blksize);
 878                 if (amount == 0)
 879                         goto empty_write;
 880
 881                 /* Perform the write */
 882                 file_offset_tmp = file_offset;
 883                 nwritten = kernel_write(curlun->filp, bh->buf, amount,
 884                                 &file_offset_tmp);
 885                 VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
 886                                 (unsigned long long)file_offset, (int)nwritten);
 887                 if (signal_pending(current))
 888                         return -EINTR;          /* Interrupted! */
 889
 890                 if (nwritten < 0) {
 891                         LDBG(curlun, "error in file write: %d\n",
 892                                         (int) nwritten);
 893                         nwritten = 0;
 894                 } else if (nwritten < amount) {
 895                         LDBG(curlun, "partial file write: %d/%u\n",
 896                                         (int) nwritten, amount);
 897                         nwritten = round_down(nwritten, curlun->blksize);
 898                 }
 899                 file_offset += nwritten;
 900                 amount_left_to_write -= nwritten;
 901                 common->residue -= nwritten;
 902
 903                 /* If an error occurred, report it and its position */
 904                 if (nwritten < amount) {
 905                         curlun->sense_data = SS_WRITE_ERROR;
 906                         curlun->sense_data_info =
 907                                         file_offset >> curlun->blkbits;
 908                         curlun->info_valid = 1;
 909                         break;
 910                 }
 911
 912  empty_write:
 913                 /* Did the host decide to stop early? */
 914                 if (bh->outreq->actual < bh->bulk_out_intended_length) {
 915                         common->short_packet_received = 1;
 916                         break;
 917                 }
 918         }
 919
 920         return -EIO;            /* No default reply */
 921 }
 922
 923
 924 /*-------------------------------------------------------------------------*/
 925
 926 static int do_synchronize_cache(struct fsg_common *common)
 927 {
 928         struct fsg_lun  *curlun = common->curlun;
 929         int             rc;
 930
 931         /* We ignore the requested LBA and write out all file's
 932          * dirty data buffers. */
 933         rc = fsg_lun_fsync_sub(curlun);
 934         if (rc)
 935                 curlun->sense_data = SS_WRITE_ERROR;
 936         return 0;
 937 }
 938
 939
 940 /*-------------------------------------------------------------------------*/
 941
 942 static void invalidate_sub(struct fsg_lun *curlun)
 943 {
 944         struct file     *filp = curlun->filp;
 945         struct inode    *inode = file_inode(filp);
 946         unsigned long   rc;
 947
 948         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
 949         VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
 950 }
 951
 952 static int do_verify(struct fsg_common *common)
 953 {
 954         struct fsg_lun          *curlun = common->curlun;
 955         u32                     lba;
 956         u32                     verification_length;
 957         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
 958         loff_t                  file_offset, file_offset_tmp;
 959         u32                     amount_left;
 960         unsigned int            amount;
 961         ssize_t                 nread;
 962
 963         /*
 964          * Get the starting Logical Block Address and check that it's
 965          * not too big.
 966          */
 967         lba = get_unaligned_be32(&common->cmnd[2]);
 968         if (lba >= curlun->num_sectors) {
 969                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 970                 return -EINVAL;
 971         }
 972
 973         /*
 974          * We allow DPO (Disable Page Out = don't save data in the
 975          * cache) but we don't implement it.
 976          */
 977         if (common->cmnd[1] & ~0x10) {
 978                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
 979                 return -EINVAL;
 980         }
 981
 982         verification_length = get_unaligned_be16(&common->cmnd[7]);
 983         if (unlikely(verification_length == 0))
 984                 return -EIO;            /* No default reply */
 985
 986         /* Prepare to carry out the file verify */
 987         amount_left = verification_length << curlun->blkbits;
 988         file_offset = ((loff_t) lba) << curlun->blkbits;
 989
 990         /* Write out all the dirty buffers before invalidating them */
 991         fsg_lun_fsync_sub(curlun);
 992         if (signal_pending(current))
 993                 return -EINTR;
 994
 995         invalidate_sub(curlun);
 996         if (signal_pending(current))
 997                 return -EINTR;
 998
 999         /* Just try to read the requested blocks */
1000         while (amount_left > 0) {
1001                 /*
1002                  * Figure out how much we need to read:
1003                  * Try to read the remaining amount, but not more than
1004                  * the buffer size.
1005                  * And don't try to read past the end of the file.
1006                  */
1007                 amount = min(amount_left, FSG_BUFLEN);
1008                 amount = min((loff_t)amount,
1009                              curlun->file_length - file_offset);
1010                 if (amount == 0) {
1011                         curlun->sense_data =
1012                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1013                         curlun->sense_data_info =
1014                                 file_offset >> curlun->blkbits;
1015                         curlun->info_valid = 1;
1016                         break;
1017                 }
1018
1019                 /* Perform the read */
1020                 file_offset_tmp = file_offset;
1021                 nread = kernel_read(curlun->filp, bh->buf, amount,
1022                                 &file_offset_tmp);
1023                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1024                                 (unsigned long long) file_offset,
1025                                 (int) nread);
1026                 if (signal_pending(current))
1027                         return -EINTR;
1028
1029                 if (nread < 0) {
1030                         LDBG(curlun, "error in file verify: %d\n", (int)nread);
1031                         nread = 0;
1032                 } else if (nread < amount) {
1033                         LDBG(curlun, "partial file verify: %d/%u\n",
1034                              (int)nread, amount);
1035                         nread = round_down(nread, curlun->blksize);
1036                 }
1037                 if (nread == 0) {
1038                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1039                         curlun->sense_data_info =
1040                                 file_offset >> curlun->blkbits;
1041                         curlun->info_valid = 1;
1042                         break;
1043                 }
1044                 file_offset += nread;
1045                 amount_left -= nread;
1046         }
1047         return 0;
1048 }
1049
1050
1051 /*-------------------------------------------------------------------------*/
1052
1053 static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
1054 {
1055         struct fsg_lun *curlun = common->curlun;
1056         u8      *buf = (u8 *) bh->buf;
1057
1058         if (!curlun) {          /* Unsupported LUNs are okay */
1059                 common->bad_lun_okay = 1;
1060                 memset(buf, 0, 36);
1061                 buf[0] = TYPE_NO_LUN;   /* Unsupported, no device-type */
1062                 buf[4] = 31;            /* Additional length */
1063                 return 36;
1064         }
1065
1066         buf[0] = curlun->cdrom ? TYPE_ROM : TYPE_DISK;
1067         buf[1] = curlun->removable ? 0x80 : 0;
1068         buf[2] = 2;             /* ANSI SCSI level 2 */
1069         buf[3] = 2;             /* SCSI-2 INQUIRY data format */
1070         buf[4] = 31;            /* Additional length */
1071         buf[5] = 0;             /* No special options */
1072         buf[6] = 0;
1073         buf[7] = 0;
1074         if (curlun->inquiry_string[0])
1075                 memcpy(buf + 8, curlun->inquiry_string,
1076                        sizeof(curlun->inquiry_string));
1077         else
1078                 memcpy(buf + 8, common->inquiry_string,
1079                        sizeof(common->inquiry_string));
1080         return 36;
1081 }
1082
1083 static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1084 {
1085         struct fsg_lun  *curlun = common->curlun;
1086         u8              *buf = (u8 *) bh->buf;
1087         u32             sd, sdinfo;
1088         int             valid;
1089
1090         /*
1091          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1092          *
1093          * If a REQUEST SENSE command is received from an initiator
1094          * with a pending unit attention condition (before the target
1095          * generates the contingent allegiance condition), then the
1096          * target shall either:
1097          *   a) report any pending sense data and preserve the unit
1098          *      attention condition on the logical unit, or,
1099          *   b) report the unit attention condition, may discard any
1100          *      pending sense data, and clear the unit attention
1101          *      condition on the logical unit for that initiator.
1102          *
1103          * FSG normally uses option a); enable this code to use option b).
1104          */
1105 #if 0
1106         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1107                 curlun->sense_data = curlun->unit_attention_data;
1108                 curlun->unit_attention_data = SS_NO_SENSE;
1109         }
1110 #endif
1111
1112         if (!curlun) {          /* Unsupported LUNs are okay */
1113                 common->bad_lun_okay = 1;
1114                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1115                 sdinfo = 0;
1116                 valid = 0;
1117         } else {
1118                 sd = curlun->sense_data;
1119                 sdinfo = curlun->sense_data_info;
1120                 valid = curlun->info_valid << 7;
1121                 curlun->sense_data = SS_NO_SENSE;
1122                 curlun->sense_data_info = 0;
1123                 curlun->info_valid = 0;
1124         }
1125
1126         memset(buf, 0, 18);
1127         buf[0] = valid | 0x70;                  /* Valid, current error */
1128         buf[2] = SK(sd);
1129         put_unaligned_be32(sdinfo, &buf[3]);    /* Sense information */
1130         buf[7] = 18 - 8;                        /* Additional sense length */
1131         buf[12] = ASC(sd);
1132         buf[13] = ASCQ(sd);
1133         return 18;
1134 }
1135
1136 static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
1137 {
1138         struct fsg_lun  *curlun = common->curlun;
1139         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1140         int             pmi = common->cmnd[8];
1141         u8              *buf = (u8 *)bh->buf;
1142
1143         /* Check the PMI and LBA fields */
1144         if (pmi > 1 || (pmi == 0 && lba != 0)) {
1145                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1146                 return -EINVAL;
1147         }
1148
1149         put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
1150                                                 /* Max logical block */
1151         put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
1152         return 8;
1153 }
1154
1155 static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
1156 {
1157         struct fsg_lun  *curlun = common->curlun;
1158         int             msf = common->cmnd[1] & 0x02;
1159         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1160         u8              *buf = (u8 *)bh->buf;
1161
1162         if (common->cmnd[1] & ~0x02) {          /* Mask away MSF */
1163                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1164                 return -EINVAL;
1165         }
1166         if (lba >= curlun->num_sectors) {
1167                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1168                 return -EINVAL;
1169         }
1170
1171         memset(buf, 0, 8);
1172         buf[0] = 0x01;          /* 2048 bytes of user data, rest is EC */
1173         store_cdrom_address(&buf[4], msf, lba);
1174         return 8;
1175 }
1176
1177 static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
1178 {
1179         struct fsg_lun  *curlun = common->curlun;
1180         int             msf = common->cmnd[1] & 0x02;
1181         int             start_track = common->cmnd[6];
1182         u8              *buf = (u8 *)bh->buf;
1183
1184         if ((common->cmnd[1] & ~0x02) != 0 ||   /* Mask away MSF */
1185                         start_track > 1) {
1186                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1187                 return -EINVAL;
1188         }
1189
1190         memset(buf, 0, 20);
1191         buf[1] = (20-2);                /* TOC data length */
1192         buf[2] = 1;                     /* First track number */
1193         buf[3] = 1;                     /* Last track number */
1194         buf[5] = 0x16;                  /* Data track, copying allowed */
1195         buf[6] = 0x01;                  /* Only track is number 1 */
1196         store_cdrom_address(&buf[8], msf, 0);
1197
1198         buf[13] = 0x16;                 /* Lead-out track is data */
1199         buf[14] = 0xAA;                 /* Lead-out track number */
1200         store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1201         return 20;
1202 }
1203
1204 static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1205 {
1206         struct fsg_lun  *curlun = common->curlun;
1207         int             mscmnd = common->cmnd[0];
1208         u8              *buf = (u8 *) bh->buf;
1209         u8              *buf0 = buf;
1210         int             pc, page_code;
1211         int             changeable_values, all_pages;
1212         int             valid_page = 0;
1213         int             len, limit;
1214
1215         if ((common->cmnd[1] & ~0x08) != 0) {   /* Mask away DBD */
1216                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1217                 return -EINVAL;
1218         }
1219         pc = common->cmnd[2] >> 6;
1220         page_code = common->cmnd[2] & 0x3f;
1221         if (pc == 3) {
1222                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1223                 return -EINVAL;
1224         }
1225         changeable_values = (pc == 1);
1226         all_pages = (page_code == 0x3f);
1227
1228         /*
1229          * Write the mode parameter header.  Fixed values are: default
1230          * medium type, no cache control (DPOFUA), and no block descriptors.
1231          * The only variable value is the WriteProtect bit.  We will fill in
1232          * the mode data length later.
1233          */
1234         memset(buf, 0, 8);
1235         if (mscmnd == MODE_SENSE) {
1236                 buf[2] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1237                 buf += 4;
1238                 limit = 255;
1239         } else {                        /* MODE_SENSE_10 */
1240                 buf[3] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1241                 buf += 8;
1242                 limit = 65535;          /* Should really be FSG_BUFLEN */
1243         }
1244
1245         /* No block descriptors */
1246
1247         /*
1248          * The mode pages, in numerical order.  The only page we support
1249          * is the Caching page.
1250          */
1251         if (page_code == 0x08 || all_pages) {
1252                 valid_page = 1;
1253                 buf[0] = 0x08;          /* Page code */
1254                 buf[1] = 10;            /* Page length */
1255                 memset(buf+2, 0, 10);   /* None of the fields are changeable */
1256
1257                 if (!changeable_values) {
1258                         buf[2] = 0x04;  /* Write cache enable, */
1259                                         /* Read cache not disabled */
1260                                         /* No cache retention priorities */
1261                         put_unaligned_be16(0xffff, &buf[4]);
1262                                         /* Don't disable prefetch */
1263                                         /* Minimum prefetch = 0 */
1264                         put_unaligned_be16(0xffff, &buf[8]);
1265                                         /* Maximum prefetch */
1266                         put_unaligned_be16(0xffff, &buf[10]);
1267                                         /* Maximum prefetch ceiling */
1268                 }
1269                 buf += 12;
1270         }
1271
1272         /*
1273          * Check that a valid page was requested and the mode data length
1274          * isn't too long.
1275          */
1276         len = buf - buf0;
1277         if (!valid_page || len > limit) {
1278                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1279                 return -EINVAL;
1280         }
1281
1282         /*  Store the mode data length */
1283         if (mscmnd == MODE_SENSE)
1284                 buf0[0] = len - 1;
1285         else
1286                 put_unaligned_be16(len - 2, buf0);
1287         return len;
1288 }
1289
1290 static int do_start_stop(struct fsg_common *common)
1291 {
1292         struct fsg_lun  *curlun = common->curlun;
1293         int             loej, start;
1294
1295         if (!curlun) {
1296                 return -EINVAL;
1297         } else if (!curlun->removable) {
1298                 curlun->sense_data = SS_INVALID_COMMAND;
1299                 return -EINVAL;
1300         } else if ((common->cmnd[1] & ~0x01) != 0 || /* Mask away Immed */
1301                    (common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */
1302                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1303                 return -EINVAL;
1304         }
1305
1306         loej  = common->cmnd[4] & 0x02;
1307         start = common->cmnd[4] & 0x01;
1308
1309         /*
1310          * Our emulation doesn't support mounting; the medium is
1311          * available for use as soon as it is loaded.
1312          */
1313         if (start) {
1314                 if (!fsg_lun_is_open(curlun)) {
1315                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1316                         return -EINVAL;
1317                 }
1318                 return 0;
1319         }
1320
1321         /* Are we allowed to unload the media? */
1322         if (curlun->prevent_medium_removal) {
1323                 LDBG(curlun, "unload attempt prevented\n");
1324                 curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
1325                 return -EINVAL;
1326         }
1327
1328         if (!loej)
1329                 return 0;
1330
1331         up_read(&common->filesem);
1332         down_write(&common->filesem);
1333         fsg_lun_close(curlun);
1334         up_write(&common->filesem);
1335         down_read(&common->filesem);
1336
1337         return 0;
1338 }
1339
1340 static int do_prevent_allow(struct fsg_common *common)
1341 {
1342         struct fsg_lun  *curlun = common->curlun;
1343         int             prevent;
1344
1345         if (!common->curlun) {
1346                 return -EINVAL;
1347         } else if (!common->curlun->removable) {
1348                 common->curlun->sense_data = SS_INVALID_COMMAND;
1349                 return -EINVAL;
1350         }
1351
1352         prevent = common->cmnd[4] & 0x01;
1353         if ((common->cmnd[4] & ~0x01) != 0) {   /* Mask away Prevent */
1354                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1355                 return -EINVAL;
1356         }
1357
1358         if (curlun->prevent_medium_removal && !prevent)
1359                 fsg_lun_fsync_sub(curlun);
1360         curlun->prevent_medium_removal = prevent;
1361         return 0;
1362 }
1363
1364 static int do_read_format_capacities(struct fsg_common *common,
1365                         struct fsg_buffhd *bh)
1366 {
1367         struct fsg_lun  *curlun = common->curlun;
1368         u8              *buf = (u8 *) bh->buf;
1369
1370         buf[0] = buf[1] = buf[2] = 0;
1371         buf[3] = 8;     /* Only the Current/Maximum Capacity Descriptor */
1372         buf += 4;
1373
1374         put_unaligned_be32(curlun->num_sectors, &buf[0]);
1375                                                 /* Number of blocks */
1376         put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
1377         buf[4] = 0x02;                          /* Current capacity */
1378         return 12;
1379 }
1380
1381 static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
1382 {
1383         struct fsg_lun  *curlun = common->curlun;
1384
1385         /* We don't support MODE SELECT */
1386         if (curlun)
1387                 curlun->sense_data = SS_INVALID_COMMAND;
1388         return -EINVAL;
1389 }
1390
1391
1392 /*-------------------------------------------------------------------------*/
1393
1394 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1395 {
1396         int     rc;
1397
1398         rc = fsg_set_halt(fsg, fsg->bulk_in);
1399         if (rc == -EAGAIN)
1400                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1401         while (rc != 0) {
1402                 if (rc != -EAGAIN) {
1403                         WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1404                         rc = 0;
1405                         break;
1406                 }
1407
1408                 /* Wait for a short time and then try again */
1409                 if (msleep_interruptible(100) != 0)
1410                         return -EINTR;
1411                 rc = usb_ep_set_halt(fsg->bulk_in);
1412         }
1413         return rc;
1414 }
1415
1416 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1417 {
1418         int     rc;
1419
1420         DBG(fsg, "bulk-in set wedge\n");
1421         rc = usb_ep_set_wedge(fsg->bulk_in);
1422         if (rc == -EAGAIN)
1423                 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1424         while (rc != 0) {
1425                 if (rc != -EAGAIN) {
1426                         WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1427                         rc = 0;
1428                         break;
1429                 }
1430
1431                 /* Wait for a short time and then try again */
1432                 if (msleep_interruptible(100) != 0)
1433                         return -EINTR;
1434                 rc = usb_ep_set_wedge(fsg->bulk_in);
1435         }
1436         return rc;
1437 }
1438
1439 static int throw_away_data(struct fsg_common *common)
1440 {
1441         struct fsg_buffhd       *bh, *bh2;
1442         u32                     amount;
1443         int                     rc;
1444
1445         for (bh = common->next_buffhd_to_drain;
1446              bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
1447              bh = common->next_buffhd_to_drain) {
1448
1449                 /* Try to submit another request if we need one */
1450                 bh2 = common->next_buffhd_to_fill;
1451                 if (bh2->state == BUF_STATE_EMPTY &&
1452                                 common->usb_amount_left > 0) {
1453                         amount = min(common->usb_amount_left, FSG_BUFLEN);
1454
1455                         /*
1456                          * Except at the end of the transfer, amount will be
1457                          * equal to the buffer size, which is divisible by
1458                          * the bulk-out maxpacket size.
1459                          */
1460                         set_bulk_out_req_length(common, bh2, amount);
1461                         if (!start_out_transfer(common, bh2))
1462                                 /* Dunno what to do if common->fsg is NULL */
1463                                 return -EIO;
1464                         common->next_buffhd_to_fill = bh2->next;
1465                         common->usb_amount_left -= amount;
1466                         continue;
1467                 }
1468
1469                 /* Wait for the data to be received */
1470                 rc = sleep_thread(common, false, bh);
1471                 if (rc)
1472                         return rc;
1473
1474                 /* Throw away the data in a filled buffer */
1475                 bh->state = BUF_STATE_EMPTY;
1476                 common->next_buffhd_to_drain = bh->next;
1477
1478                 /* A short packet or an error ends everything */
1479                 if (bh->outreq->actual < bh->bulk_out_intended_length ||
1480                                 bh->outreq->status != 0) {
1481                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1482                         return -EINTR;
1483                 }
1484         }
1485         return 0;
1486 }
1487
1488 static int finish_reply(struct fsg_common *common)
1489 {
1490         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
1491         int                     rc = 0;
1492
1493         switch (common->data_dir) {
1494         case DATA_DIR_NONE:
1495                 break;                  /* Nothing to send */
1496
1497         /*
1498          * If we don't know whether the host wants to read or write,
1499          * this must be CB or CBI with an unknown command.  We mustn't
1500          * try to send or receive any data.  So stall both bulk pipes
1501          * if we can and wait for a reset.
1502          */
1503         case DATA_DIR_UNKNOWN:
1504                 if (!common->can_stall) {
1505                         /* Nothing */
1506                 } else if (fsg_is_set(common)) {
1507                         fsg_set_halt(common->fsg, common->fsg->bulk_out);
1508                         rc = halt_bulk_in_endpoint(common->fsg);
1509                 } else {
1510                         /* Don't know what to do if common->fsg is NULL */
1511                         rc = -EIO;
1512                 }
1513                 break;
1514
1515         /* All but the last buffer of data must have already been sent */
1516         case DATA_DIR_TO_HOST:
1517                 if (common->data_size == 0) {
1518                         /* Nothing to send */
1519
1520                 /* Don't know what to do if common->fsg is NULL */
1521                 } else if (!fsg_is_set(common)) {
1522                         rc = -EIO;
1523
1524                 /* If there's no residue, simply send the last buffer */
1525                 } else if (common->residue == 0) {
1526                         bh->inreq->zero = 0;
1527                         if (!start_in_transfer(common, bh))
1528                                 return -EIO;
1529                         common->next_buffhd_to_fill = bh->next;
1530
1531                 /*
1532                  * For Bulk-only, mark the end of the data with a short
1533                  * packet.  If we are allowed to stall, halt the bulk-in
1534                  * endpoint.  (Note: This violates the Bulk-Only Transport
1535                  * specification, which requires us to pad the data if we
1536                  * don't halt the endpoint.  Presumably nobody will mind.)
1537                  */
1538                 } else {
1539                         bh->inreq->zero = 1;
1540                         if (!start_in_transfer(common, bh))
1541                                 rc = -EIO;
1542                         common->next_buffhd_to_fill = bh->next;
1543                         if (common->can_stall)
1544                                 rc = halt_bulk_in_endpoint(common->fsg);
1545                 }
1546                 break;
1547
1548         /*
1549          * We have processed all we want from the data the host has sent.
1550          * There may still be outstanding bulk-out requests.
1551          */
1552         case DATA_DIR_FROM_HOST:
1553                 if (common->residue == 0) {
1554                         /* Nothing to receive */
1555
1556                 /* Did the host stop sending unexpectedly early? */
1557                 } else if (common->short_packet_received) {
1558                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1559                         rc = -EINTR;
1560
1561                 /*
1562                  * We haven't processed all the incoming data.  Even though
1563                  * we may be allowed to stall, doing so would cause a race.
1564                  * The controller may already have ACK'ed all the remaining
1565                  * bulk-out packets, in which case the host wouldn't see a
1566                  * STALL.  Not realizing the endpoint was halted, it wouldn't
1567                  * clear the halt -- leading to problems later on.
1568                  */
1569 #if 0
1570                 } else if (common->can_stall) {
1571                         if (fsg_is_set(common))
1572                                 fsg_set_halt(common->fsg,
1573                                              common->fsg->bulk_out);
1574                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1575                         rc = -EINTR;
1576 #endif
1577
1578                 /*
1579                  * We can't stall.  Read in the excess data and throw it
1580                  * all away.
1581                  */
1582                 } else {
1583                         rc = throw_away_data(common);
1584                 }
1585                 break;
1586         }
1587         return rc;
1588 }
1589
1590 static void send_status(struct fsg_common *common)
1591 {
1592         struct fsg_lun          *curlun = common->curlun;
1593         struct fsg_buffhd       *bh;
1594         struct bulk_cs_wrap     *csw;
1595         int                     rc;
1596         u8                      status = US_BULK_STAT_OK;
1597         u32                     sd, sdinfo = 0;
1598
1599         /* Wait for the next buffer to become available */
1600         bh = common->next_buffhd_to_fill;
1601         rc = sleep_thread(common, false, bh);
1602         if (rc)
1603                 return;
1604
1605         if (curlun) {
1606                 sd = curlun->sense_data;
1607                 sdinfo = curlun->sense_data_info;
1608         } else if (common->bad_lun_okay)
1609                 sd = SS_NO_SENSE;
1610         else
1611                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1612
1613         if (common->phase_error) {
1614                 DBG(common, "sending phase-error status\n");
1615                 status = US_BULK_STAT_PHASE;
1616                 sd = SS_INVALID_COMMAND;
1617         } else if (sd != SS_NO_SENSE) {
1618                 DBG(common, "sending command-failure status\n");
1619                 status = US_BULK_STAT_FAIL;
1620                 VDBG(common, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
1621                                 "  info x%x\n",
1622                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
1623         }
1624
1625         /* Store and send the Bulk-only CSW */
1626         csw = (void *)bh->buf;
1627
1628         csw->Signature = cpu_to_le32(US_BULK_CS_SIGN);
1629         csw->Tag = common->tag;
1630         csw->Residue = cpu_to_le32(common->residue);
1631         csw->Status = status;
1632
1633         bh->inreq->length = US_BULK_CS_WRAP_LEN;
1634         bh->inreq->zero = 0;
1635         if (!start_in_transfer(common, bh))
1636                 /* Don't know what to do if common->fsg is NULL */
1637                 return;
1638
1639         common->next_buffhd_to_fill = bh->next;
1640         return;
1641 }
1642
1643
1644 /*-------------------------------------------------------------------------*/
1645
1646 /*
1647  * Check whether the command is properly formed and whether its data size
1648  * and direction agree with the values we already have.
1649  */
1650 static int check_command(struct fsg_common *common, int cmnd_size,
1651                          enum data_direction data_dir, unsigned int mask,
1652                          int needs_medium, const char *name)
1653 {
1654         int                     i;
1655         unsigned int            lun = common->cmnd[1] >> 5;
1656         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
1657         char                    hdlen[20];
1658         struct fsg_lun          *curlun;
1659
1660         hdlen[0] = 0;
1661         if (common->data_dir != DATA_DIR_UNKNOWN)
1662                 sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
1663                         common->data_size);
1664         VDBG(common, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
1665              name, cmnd_size, dirletter[(int) data_dir],
1666              common->data_size_from_cmnd, common->cmnd_size, hdlen);
1667
1668         /*
1669          * We can't reply at all until we know the correct data direction
1670          * and size.
1671          */
1672         if (common->data_size_from_cmnd == 0)
1673                 data_dir = DATA_DIR_NONE;
1674         if (common->data_size < common->data_size_from_cmnd) {
1675                 /*
1676                  * Host data size < Device data size is a phase error.
1677                  * Carry out the command, but only transfer as much as
1678                  * we are allowed.
1679                  */
1680                 common->data_size_from_cmnd = common->data_size;
1681                 common->phase_error = 1;
1682         }
1683         common->residue = common->data_size;
1684         common->usb_amount_left = common->data_size;
1685
1686         /* Conflicting data directions is a phase error */
1687         if (common->data_dir != data_dir && common->data_size_from_cmnd > 0) {
1688                 common->phase_error = 1;
1689                 return -EINVAL;
1690         }
1691
1692         /* Verify the length of the command itself */
1693         if (cmnd_size != common->cmnd_size) {
1694
1695                 /*
1696                  * Special case workaround: There are plenty of buggy SCSI
1697                  * implementations. Many have issues with cbw->Length
1698                  * field passing a wrong command size. For those cases we
1699                  * always try to work around the problem by using the length
1700                  * sent by the host side provided it is at least as large
1701                  * as the correct command length.
1702                  * Examples of such cases would be MS-Windows, which issues
1703                  * REQUEST SENSE with cbw->Length == 12 where it should
1704                  * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
1705                  * REQUEST SENSE with cbw->Length == 10 where it should
1706                  * be 6 as well.
1707                  */
1708                 if (cmnd_size <= common->cmnd_size) {
1709                         DBG(common, "%s is buggy! Expected length %d "
1710                             "but we got %d\n", name,
1711                             cmnd_size, common->cmnd_size);
1712                         cmnd_size = common->cmnd_size;
1713                 } else {
1714                         common->phase_error = 1;
1715                         return -EINVAL;
1716                 }
1717         }
1718
1719         /* Check that the LUN values are consistent */
1720         if (common->lun != lun)
1721                 DBG(common, "using LUN %u from CBW, not LUN %u from CDB\n",
1722                     common->lun, lun);
1723
1724         /* Check the LUN */
1725         curlun = common->curlun;
1726         if (curlun) {
1727                 if (common->cmnd[0] != REQUEST_SENSE) {
1728                         curlun->sense_data = SS_NO_SENSE;
1729                         curlun->sense_data_info = 0;
1730                         curlun->info_valid = 0;
1731                 }
1732         } else {
1733                 common->bad_lun_okay = 0;
1734
1735                 /*
1736                  * INQUIRY and REQUEST SENSE commands are explicitly allowed
1737                  * to use unsupported LUNs; all others may not.
1738                  */
1739                 if (common->cmnd[0] != INQUIRY &&
1740                     common->cmnd[0] != REQUEST_SENSE) {
1741                         DBG(common, "unsupported LUN %u\n", common->lun);
1742                         return -EINVAL;
1743                 }
1744         }
1745
1746         /*
1747          * If a unit attention condition exists, only INQUIRY and
1748          * REQUEST SENSE commands are allowed; anything else must fail.
1749          */
1750         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
1751             common->cmnd[0] != INQUIRY &&
1752             common->cmnd[0] != REQUEST_SENSE) {
1753                 curlun->sense_data = curlun->unit_attention_data;
1754                 curlun->unit_attention_data = SS_NO_SENSE;
1755                 return -EINVAL;
1756         }
1757
1758         /* Check that only command bytes listed in the mask are non-zero */
1759         common->cmnd[1] &= 0x1f;                        /* Mask away the LUN */
1760         for (i = 1; i < cmnd_size; ++i) {
1761                 if (common->cmnd[i] && !(mask & (1 << i))) {
1762                         if (curlun)
1763                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1764                         return -EINVAL;
1765                 }
1766         }
1767
1768         /* If the medium isn't mounted and the command needs to access
1769          * it, return an error. */
1770         if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
1771                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1772                 return -EINVAL;
1773         }
1774
1775         return 0;
1776 }
1777
1778 /* wrapper of check_command for data size in blocks handling */
1779 static int check_command_size_in_blocks(struct fsg_common *common,
1780                 int cmnd_size, enum data_direction data_dir,
1781                 unsigned int mask, int needs_medium, const char *name)
1782 {
1783         if (common->curlun)
1784                 common->data_size_from_cmnd <<= common->curlun->blkbits;
1785         return check_command(common, cmnd_size, data_dir,
1786                         mask, needs_medium, name);
1787 }
1788
1789 static int do_scsi_command(struct fsg_common *common)
1790 {
1791         struct fsg_buffhd       *bh;
1792         int                     rc;
1793         int                     reply = -EINVAL;
1794         int                     i;
1795         static char             unknown[16];
1796
1797         dump_cdb(common);
1798
1799         /* Wait for the next buffer to become available for data or status */
1800         bh = common->next_buffhd_to_fill;
1801         common->next_buffhd_to_drain = bh;
1802         rc = sleep_thread(common, false, bh);
1803         if (rc)
1804                 return rc;
1805
1806         common->phase_error = 0;
1807         common->short_packet_received = 0;
1808
1809         down_read(&common->filesem);    /* We're using the backing file */
1810         switch (common->cmnd[0]) {
1811
1812         case INQUIRY:
1813                 common->data_size_from_cmnd = common->cmnd[4];
1814                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1815                                       (1<<4), 0,
1816                                       "INQUIRY");
1817                 if (reply == 0)
1818                         reply = do_inquiry(common, bh);
1819                 break;
1820
1821         case MODE_SELECT:
1822                 common->data_size_from_cmnd = common->cmnd[4];
1823                 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
1824                                       (1<<1) | (1<<4), 0,
1825                                       "MODE SELECT(6)");
1826                 if (reply == 0)
1827                         reply = do_mode_select(common, bh);
1828                 break;
1829
1830         case MODE_SELECT_10:
1831                 common->data_size_from_cmnd =
1832                         get_unaligned_be16(&common->cmnd[7]);
1833                 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
1834                                       (1<<1) | (3<<7), 0,
1835                                       "MODE SELECT(10)");
1836                 if (reply == 0)
1837                         reply = do_mode_select(common, bh);
1838                 break;
1839
1840         case MODE_SENSE:
1841                 common->data_size_from_cmnd = common->cmnd[4];
1842                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1843                                       (1<<1) | (1<<2) | (1<<4), 0,
1844                                       "MODE SENSE(6)");
1845                 if (reply == 0)
1846                         reply = do_mode_sense(common, bh);
1847                 break;
1848
1849         case MODE_SENSE_10:
1850                 common->data_size_from_cmnd =
1851                         get_unaligned_be16(&common->cmnd[7]);
1852                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1853                                       (1<<1) | (1<<2) | (3<<7), 0,
1854                                       "MODE SENSE(10)");
1855                 if (reply == 0)
1856                         reply = do_mode_sense(common, bh);
1857                 break;
1858
1859         case ALLOW_MEDIUM_REMOVAL:
1860                 common->data_size_from_cmnd = 0;
1861                 reply = check_command(common, 6, DATA_DIR_NONE,
1862                                       (1<<4), 0,
1863                                       "PREVENT-ALLOW MEDIUM REMOVAL");
1864                 if (reply == 0)
1865                         reply = do_prevent_allow(common);
1866                 break;
1867
1868         case READ_6:
1869                 i = common->cmnd[4];
1870                 common->data_size_from_cmnd = (i == 0) ? 256 : i;
1871                 reply = check_command_size_in_blocks(common, 6,
1872                                       DATA_DIR_TO_HOST,
1873                                       (7<<1) | (1<<4), 1,
1874                                       "READ(6)");
1875                 if (reply == 0)
1876                         reply = do_read(common);
1877                 break;
1878
1879         case READ_10:
1880                 common->data_size_from_cmnd =
1881                                 get_unaligned_be16(&common->cmnd[7]);
1882                 reply = check_command_size_in_blocks(common, 10,
1883                                       DATA_DIR_TO_HOST,
1884                                       (1<<1) | (0xf<<2) | (3<<7), 1,
1885                                       "READ(10)");
1886                 if (reply == 0)
1887                         reply = do_read(common);
1888                 break;
1889
1890         case READ_12:
1891                 common->data_size_from_cmnd =
1892                                 get_unaligned_be32(&common->cmnd[6]);
1893                 reply = check_command_size_in_blocks(common, 12,
1894                                       DATA_DIR_TO_HOST,
1895                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
1896                                       "READ(12)");
1897                 if (reply == 0)
1898                         reply = do_read(common);
1899                 break;
1900
1901         case READ_CAPACITY:
1902                 common->data_size_from_cmnd = 8;
1903                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1904                                       (0xf<<2) | (1<<8), 1,
1905                                       "READ CAPACITY");
1906                 if (reply == 0)
1907                         reply = do_read_capacity(common, bh);
1908                 break;
1909
1910         case READ_HEADER:
1911                 if (!common->curlun || !common->curlun->cdrom)
1912                         goto unknown_cmnd;
1913                 common->data_size_from_cmnd =
1914                         get_unaligned_be16(&common->cmnd[7]);
1915                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1916                                       (3<<7) | (0x1f<<1), 1,
1917                                       "READ HEADER");
1918                 if (reply == 0)
1919                         reply = do_read_header(common, bh);
1920                 break;
1921
1922         case READ_TOC:
1923                 if (!common->curlun || !common->curlun->cdrom)
1924                         goto unknown_cmnd;
1925                 common->data_size_from_cmnd =
1926                         get_unaligned_be16(&common->cmnd[7]);
1927                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1928                                       (7<<6) | (1<<1), 1,
1929                                       "READ TOC");
1930                 if (reply == 0)
1931                         reply = do_read_toc(common, bh);
1932                 break;
1933
1934         case READ_FORMAT_CAPACITIES:
1935                 common->data_size_from_cmnd =
1936                         get_unaligned_be16(&common->cmnd[7]);
1937                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1938                                       (3<<7), 1,
1939                                       "READ FORMAT CAPACITIES");
1940                 if (reply == 0)
1941                         reply = do_read_format_capacities(common, bh);
1942                 break;
1943
1944         case REQUEST_SENSE:
1945                 common->data_size_from_cmnd = common->cmnd[4];
1946                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1947                                       (1<<4), 0,
1948                                       "REQUEST SENSE");
1949                 if (reply == 0)
1950                         reply = do_request_sense(common, bh);
1951                 break;
1952
1953         case START_STOP:
1954                 common->data_size_from_cmnd = 0;
1955                 reply = check_command(common, 6, DATA_DIR_NONE,
1956                                       (1<<1) | (1<<4), 0,
1957                                       "START-STOP UNIT");
1958                 if (reply == 0)
1959                         reply = do_start_stop(common);
1960                 break;
1961
1962         case SYNCHRONIZE_CACHE:
1963                 common->data_size_from_cmnd = 0;
1964                 reply = check_command(common, 10, DATA_DIR_NONE,
1965                                       (0xf<<2) | (3<<7), 1,
1966                                       "SYNCHRONIZE CACHE");
1967                 if (reply == 0)
1968                         reply = do_synchronize_cache(common);
1969                 break;
1970
1971         case TEST_UNIT_READY:
1972                 common->data_size_from_cmnd = 0;
1973                 reply = check_command(common, 6, DATA_DIR_NONE,
1974                                 0, 1,
1975                                 "TEST UNIT READY");
1976                 break;
1977
1978         /*
1979          * Although optional, this command is used by MS-Windows.  We
1980          * support a minimal version: BytChk must be 0.
1981          */
1982         case VERIFY:
1983                 common->data_size_from_cmnd = 0;
1984                 reply = check_command(common, 10, DATA_DIR_NONE,
1985                                       (1<<1) | (0xf<<2) | (3<<7), 1,
1986                                       "VERIFY");
1987                 if (reply == 0)
1988                         reply = do_verify(common);
1989                 break;
1990
1991         case WRITE_6:
1992                 i = common->cmnd[4];
1993                 common->data_size_from_cmnd = (i == 0) ? 256 : i;
1994                 reply = check_command_size_in_blocks(common, 6,
1995                                       DATA_DIR_FROM_HOST,
1996                                       (7<<1) | (1<<4), 1,
1997                                       "WRITE(6)");
1998                 if (reply == 0)
1999                         reply = do_write(common);
2000                 break;
2001
2002         case WRITE_10:
2003                 common->data_size_from_cmnd =
2004                                 get_unaligned_be16(&common->cmnd[7]);
2005                 reply = check_command_size_in_blocks(common, 10,
2006                                       DATA_DIR_FROM_HOST,
2007                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2008                                       "WRITE(10)");
2009                 if (reply == 0)
2010                         reply = do_write(common);
2011                 break;
2012
2013         case WRITE_12:
2014                 common->data_size_from_cmnd =
2015                                 get_unaligned_be32(&common->cmnd[6]);
2016                 reply = check_command_size_in_blocks(common, 12,
2017                                       DATA_DIR_FROM_HOST,
2018                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
2019                                       "WRITE(12)");
2020                 if (reply == 0)
2021                         reply = do_write(common);
2022                 break;
2023
2024         /*
2025          * Some mandatory commands that we recognize but don't implement.
2026          * They don't mean much in this setting.  It's left as an exercise
2027          * for anyone interested to implement RESERVE and RELEASE in terms
2028          * of Posix locks.
2029          */
2030         case FORMAT_UNIT:
2031         case RELEASE:
2032         case RESERVE:
2033         case SEND_DIAGNOSTIC:
2034                 /* Fall through */
2035
2036         default:
2037 unknown_cmnd:
2038                 common->data_size_from_cmnd = 0;
2039                 sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
2040                 reply = check_command(common, common->cmnd_size,
2041                                       DATA_DIR_UNKNOWN, ~0, 0, unknown);
2042                 if (reply == 0) {
2043                         common->curlun->sense_data = SS_INVALID_COMMAND;
2044                         reply = -EINVAL;
2045                 }
2046                 break;
2047         }
2048         up_read(&common->filesem);
2049
2050         if (reply == -EINTR || signal_pending(current))
2051                 return -EINTR;
2052
2053         /* Set up the single reply buffer for finish_reply() */
2054         if (reply == -EINVAL)
2055                 reply = 0;              /* Error reply length */
2056         if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
2057                 reply = min((u32)reply, common->data_size_from_cmnd);
2058                 bh->inreq->length = reply;
2059                 bh->state = BUF_STATE_FULL;
2060                 common->residue -= reply;
2061         }                               /* Otherwise it's already set */
2062
2063         return 0;
2064 }
2065
2066
2067 /*-------------------------------------------------------------------------*/
2068
2069 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2070 {
2071         struct usb_request      *req = bh->outreq;
2072         struct bulk_cb_wrap     *cbw = req->buf;
2073         struct fsg_common       *common = fsg->common;
2074
2075         /* Was this a real packet?  Should it be ignored? */
2076         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2077                 return -EINVAL;
2078
2079         /* Is the CBW valid? */
2080         if (req->actual != US_BULK_CB_WRAP_LEN ||
2081                         cbw->Signature != cpu_to_le32(
2082                                 US_BULK_CB_SIGN)) {
2083                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2084                                 req->actual,
2085                                 le32_to_cpu(cbw->Signature));
2086
2087                 /*
2088                  * The Bulk-only spec says we MUST stall the IN endpoint
2089                  * (6.6.1), so it's unavoidable.  It also says we must
2090                  * retain this state until the next reset, but there's
2091                  * no way to tell the controller driver it should ignore
2092                  * Clear-Feature(HALT) requests.
2093                  *
2094                  * We aren't required to halt the OUT endpoint; instead
2095                  * we can simply accept and discard any data received
2096                  * until the next reset.
2097                  */
2098                 wedge_bulk_in_endpoint(fsg);
2099                 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2100                 return -EINVAL;
2101         }
2102
2103         /* Is the CBW meaningful? */
2104         if (cbw->Lun >= ARRAY_SIZE(common->luns) ||
2105             cbw->Flags & ~US_BULK_FLAG_IN || cbw->Length <= 0 ||
2106             cbw->Length > MAX_COMMAND_SIZE) {
2107                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2108                                 "cmdlen %u\n",
2109                                 cbw->Lun, cbw->Flags, cbw->Length);
2110
2111                 /*
2112                  * We can do anything we want here, so let's stall the
2113                  * bulk pipes if we are allowed to.
2114                  */
2115                 if (common->can_stall) {
2116                         fsg_set_halt(fsg, fsg->bulk_out);
2117                         halt_bulk_in_endpoint(fsg);
2118                 }
2119                 return -EINVAL;
2120         }
2121
2122         /* Save the command for later */
2123         common->cmnd_size = cbw->Length;
2124         memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
2125         if (cbw->Flags & US_BULK_FLAG_IN)
2126                 common->data_dir = DATA_DIR_TO_HOST;
2127         else
2128                 common->data_dir = DATA_DIR_FROM_HOST;
2129         common->data_size = le32_to_cpu(cbw->DataTransferLength);
2130         if (common->data_size == 0)
2131                 common->data_dir = DATA_DIR_NONE;
2132         common->lun = cbw->Lun;
2133         if (common->lun < ARRAY_SIZE(common->luns))
2134                 common->curlun = common->luns[common->lun];
2135         else
2136                 common->curlun = NULL;
2137         common->tag = cbw->Tag;
2138         return 0;
2139 }
2140
2141 static int get_next_command(struct fsg_common *common)
2142 {
2143         struct fsg_buffhd       *bh;
2144         int                     rc = 0;
2145
2146         /* Wait for the next buffer to become available */
2147         bh = common->next_buffhd_to_fill;
2148         rc = sleep_thread(common, true, bh);
2149         if (rc)
2150                 return rc;
2151
2152         /* Queue a request to read a Bulk-only CBW */
2153         set_bulk_out_req_length(common, bh, US_BULK_CB_WRAP_LEN);
2154         if (!start_out_transfer(common, bh))
2155                 /* Don't know what to do if common->fsg is NULL */
2156                 return -EIO;
2157
2158         /*
2159          * We will drain the buffer in software, which means we
2160          * can reuse it for the next filling.  No need to advance
2161          * next_buffhd_to_fill.
2162          */
2163
2164         /* Wait for the CBW to arrive */
2165         rc = sleep_thread(common, true, bh);
2166         if (rc)
2167                 return rc;
2168
2169         rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
2170         bh->state = BUF_STATE_EMPTY;
2171
2172         return rc;
2173 }
2174
2175
2176 /*-------------------------------------------------------------------------*/
2177
2178 static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
2179                 struct usb_request **preq)
2180 {
2181         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2182         if (*preq)
2183                 return 0;
2184         ERROR(common, "can't allocate request for %s\n", ep->name);
2185         return -ENOMEM;
2186 }
2187
2188 /* Reset interface setting and re-init endpoint state (toggle etc). */
2189 static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
2190 {
2191         struct fsg_dev *fsg;
2192         int i, rc = 0;
2193
2194         if (common->running)
2195                 DBG(common, "reset interface\n");
2196
2197 reset:
2198         /* Deallocate the requests */
2199         if (common->fsg) {
2200                 fsg = common->fsg;
2201
2202                 for (i = 0; i < common->fsg_num_buffers; ++i) {
2203                         struct fsg_buffhd *bh = &common->buffhds[i];
2204
2205                         if (bh->inreq) {
2206                                 usb_ep_free_request(fsg->bulk_in, bh->inreq);
2207                                 bh->inreq = NULL;
2208                         }
2209                         if (bh->outreq) {
2210                                 usb_ep_free_request(fsg->bulk_out, bh->outreq);
2211                                 bh->outreq = NULL;
2212                         }
2213                 }
2214
2215                 /* Disable the endpoints */
2216                 if (fsg->bulk_in_enabled) {
2217                         usb_ep_disable(fsg->bulk_in);
2218                         fsg->bulk_in_enabled = 0;
2219                 }
2220                 if (fsg->bulk_out_enabled) {
2221                         usb_ep_disable(fsg->bulk_out);
2222                         fsg->bulk_out_enabled = 0;
2223                 }
2224
2225                 common->fsg = NULL;
2226                 wake_up(&common->fsg_wait);
2227         }
2228
2229         common->running = 0;
2230         if (!new_fsg || rc)
2231                 return rc;
2232
2233         common->fsg = new_fsg;
2234         fsg = common->fsg;
2235
2236         /* Enable the endpoints */
2237         rc = config_ep_by_speed(common->gadget, &(fsg->function), fsg->bulk_in);
2238         if (rc)
2239                 goto reset;
2240         rc = usb_ep_enable(fsg->bulk_in);
2241         if (rc)
2242                 goto reset;
2243         fsg->bulk_in->driver_data = common;
2244         fsg->bulk_in_enabled = 1;
2245
2246         rc = config_ep_by_speed(common->gadget, &(fsg->function),
2247                                 fsg->bulk_out);
2248         if (rc)
2249                 goto reset;
2250         rc = usb_ep_enable(fsg->bulk_out);
2251         if (rc)
2252                 goto reset;
2253         fsg->bulk_out->driver_data = common;
2254         fsg->bulk_out_enabled = 1;
2255         common->bulk_out_maxpacket = usb_endpoint_maxp(fsg->bulk_out->desc);
2256         clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2257
2258         /* Allocate the requests */
2259         for (i = 0; i < common->fsg_num_buffers; ++i) {
2260                 struct fsg_buffhd       *bh = &common->buffhds[i];
2261
2262                 rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
2263                 if (rc)
2264                         goto reset;
2265                 rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
2266                 if (rc)
2267                         goto reset;
2268                 bh->inreq->buf = bh->outreq->buf = bh->buf;
2269                 bh->inreq->context = bh->outreq->context = bh;
2270                 bh->inreq->complete = bulk_in_complete;
2271                 bh->outreq->complete = bulk_out_complete;
2272         }
2273
2274         common->running = 1;
2275         for (i = 0; i < ARRAY_SIZE(common->luns); ++i)
2276                 if (common->luns[i])
2277                         common->luns[i]->unit_attention_data =
2278                                 SS_RESET_OCCURRED;
2279         return rc;
2280 }
2281
2282
2283 /****************************** ALT CONFIGS ******************************/
2284
2285 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
2286 {
2287         struct fsg_dev *fsg = fsg_from_func(f);
2288         fsg->common->new_fsg = fsg;
2289         raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2290         return USB_GADGET_DELAYED_STATUS;
2291 }
2292
2293 static void fsg_disable(struct usb_function *f)
2294 {
2295         struct fsg_dev *fsg = fsg_from_func(f);
2296         fsg->common->new_fsg = NULL;
2297         raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2298 }
2299
2300
2301 /*-------------------------------------------------------------------------*/
2302
2303 static void handle_exception(struct fsg_common *common)
2304 {
2305         int                     i;
2306         struct fsg_buffhd       *bh;
2307         enum fsg_state          old_state;
2308         struct fsg_lun          *curlun;
2309         unsigned int            exception_req_tag;
2310
2311         /*
2312          * Clear the existing signals.  Anything but SIGUSR1 is converted
2313          * into a high-priority EXIT exception.
2314          */
2315         for (;;) {
2316                 int sig = kernel_dequeue_signal();
2317                 if (!sig)
2318                         break;
2319                 if (sig != SIGUSR1) {
2320                         spin_lock_irq(&common->lock);
2321                         if (common->state < FSG_STATE_EXIT)
2322                                 DBG(common, "Main thread exiting on signal\n");
2323                         common->state = FSG_STATE_EXIT;
2324                         spin_unlock_irq(&common->lock);
2325                 }
2326         }
2327
2328         /* Cancel all the pending transfers */
2329         if (likely(common->fsg)) {
2330                 for (i = 0; i < common->fsg_num_buffers; ++i) {
2331                         bh = &common->buffhds[i];
2332                         if (bh->state == BUF_STATE_SENDING)
2333                                 usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
2334                         if (bh->state == BUF_STATE_RECEIVING)
2335                                 usb_ep_dequeue(common->fsg->bulk_out,
2336                                                bh->outreq);
2337
2338                         /* Wait for a transfer to become idle */
2339                         if (sleep_thread(common, false, bh))
2340                                 return;
2341                 }
2342
2343                 /* Clear out the controller's fifos */
2344                 if (common->fsg->bulk_in_enabled)
2345                         usb_ep_fifo_flush(common->fsg->bulk_in);
2346                 if (common->fsg->bulk_out_enabled)
2347                         usb_ep_fifo_flush(common->fsg->bulk_out);
2348         }
2349
2350         /*
2351          * Reset the I/O buffer states and pointers, the SCSI
2352          * state, and the exception.  Then invoke the handler.
2353          */
2354         spin_lock_irq(&common->lock);
2355
2356         for (i = 0; i < common->fsg_num_buffers; ++i) {
2357                 bh = &common->buffhds[i];
2358                 bh->state = BUF_STATE_EMPTY;
2359         }
2360         common->next_buffhd_to_fill = &common->buffhds[0];
2361         common->next_buffhd_to_drain = &common->buffhds[0];
2362         exception_req_tag = common->exception_req_tag;
2363         old_state = common->state;
2364         common->state = FSG_STATE_NORMAL;
2365
2366         if (old_state != FSG_STATE_ABORT_BULK_OUT) {
2367                 for (i = 0; i < ARRAY_SIZE(common->luns); ++i) {
2368                         curlun = common->luns[i];
2369                         if (!curlun)
2370                                 continue;
2371                         curlun->prevent_medium_removal = 0;
2372                         curlun->sense_data = SS_NO_SENSE;
2373                         curlun->unit_attention_data = SS_NO_SENSE;
2374                         curlun->sense_data_info = 0;
2375                         curlun->info_valid = 0;
2376                 }
2377         }
2378         spin_unlock_irq(&common->lock);
2379
2380         /* Carry out any extra actions required for the exception */
2381         switch (old_state) {
2382         case FSG_STATE_NORMAL:
2383                 break;
2384
2385         case FSG_STATE_ABORT_BULK_OUT:
2386                 send_status(common);
2387                 break;
2388
2389         case FSG_STATE_PROTOCOL_RESET:
2390                 /*
2391                  * In case we were forced against our will to halt a
2392                  * bulk endpoint, clear the halt now.  (The SuperH UDC
2393                  * requires this.)
2394                  */
2395                 if (!fsg_is_set(common))
2396                         break;
2397                 if (test_and_clear_bit(IGNORE_BULK_OUT,
2398                                        &common->fsg->atomic_bitflags))
2399                         usb_ep_clear_halt(common->fsg->bulk_in);
2400
2401                 if (common->ep0_req_tag == exception_req_tag)
2402                         ep0_queue(common);      /* Complete the status stage */
2403
2404                 /*
2405                  * Technically this should go here, but it would only be
2406                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
2407                  * CONFIG_CHANGE cases.
2408                  */
2409                 /* for (i = 0; i < common->ARRAY_SIZE(common->luns); ++i) */
2410                 /*      if (common->luns[i]) */
2411                 /*              common->luns[i]->unit_attention_data = */
2412                 /*                      SS_RESET_OCCURRED;  */
2413                 break;
2414
2415         case FSG_STATE_CONFIG_CHANGE:
2416                 do_set_interface(common, common->new_fsg);
2417                 if (common->new_fsg)
2418                         usb_composite_setup_continue(common->cdev);
2419                 break;
2420
2421         case FSG_STATE_EXIT:
2422                 do_set_interface(common, NULL);         /* Free resources */
2423                 spin_lock_irq(&common->lock);
2424                 common->state = FSG_STATE_TERMINATED;   /* Stop the thread */
2425                 spin_unlock_irq(&common->lock);
2426                 break;
2427
2428         case FSG_STATE_TERMINATED:
2429                 break;
2430         }
2431 }
2432
2433
2434 /*-------------------------------------------------------------------------*/
2435
2436 static int fsg_main_thread(void *common_)
2437 {
2438         struct fsg_common       *common = common_;
2439         int                     i;
2440
2441         /*
2442          * Allow the thread to be killed by a signal, but set the signal mask
2443          * to block everything but INT, TERM, KILL, and USR1.
2444          */
2445         allow_signal(SIGINT);
2446         allow_signal(SIGTERM);
2447         allow_signal(SIGKILL);
2448         allow_signal(SIGUSR1);
2449
2450         /* Allow the thread to be frozen */
2451         set_freezable();
2452
2453         /* The main loop */
2454         while (common->state != FSG_STATE_TERMINATED) {
2455                 if (exception_in_progress(common) || signal_pending(current)) {
2456                         handle_exception(common);
2457                         continue;
2458                 }
2459
2460                 if (!common->running) {
2461                         sleep_thread(common, true, NULL);
2462                         continue;
2463                 }
2464
2465                 if (get_next_command(common) || exception_in_progress(common))
2466                         continue;
2467                 if (do_scsi_command(common) || exception_in_progress(common))
2468                         continue;
2469                 if (finish_reply(common) || exception_in_progress(common))
2470                         continue;
2471                 send_status(common);
2472         }
2473
2474         spin_lock_irq(&common->lock);
2475         common->thread_task = NULL;
2476         spin_unlock_irq(&common->lock);
2477
2478         /* Eject media from all LUNs */
2479
2480         down_write(&common->filesem);
2481         for (i = 0; i < ARRAY_SIZE(common->luns); i++) {
2482                 struct fsg_lun *curlun = common->luns[i];
2483
2484                 if (curlun && fsg_lun_is_open(curlun))
2485                         fsg_lun_close(curlun);
2486         }
2487         up_write(&common->filesem);
2488
2489         /* Let fsg_unbind() know the thread has exited */
2490         complete_and_exit(&common->thread_notifier, 0);
2491 }
2492
2493
2494 /*************************** DEVICE ATTRIBUTES ***************************/
2495
2496 static ssize_t ro_show(struct device *dev, struct device_attribute *attr, char *buf)
2497 {
2498         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2499
2500         return fsg_show_ro(curlun, buf);
2501 }
2502
2503 static ssize_t nofua_show(struct device *dev, struct device_attribute *attr,
2504                           char *buf)
2505 {
2506         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2507
2508         return fsg_show_nofua(curlun, buf);
2509 }
2510
2511 static ssize_t file_show(struct device *dev, struct device_attribute *attr,
2512                          char *buf)
2513 {
2514         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2515         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2516
2517         return fsg_show_file(curlun, filesem, buf);
2518 }
2519
2520 static ssize_t ro_store(struct device *dev, struct device_attribute *attr,
2521                         const char *buf, size_t count)
2522 {
2523         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2524         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2525
2526         return fsg_store_ro(curlun, filesem, buf, count);
2527 }
2528
2529 static ssize_t nofua_store(struct device *dev, struct device_attribute *attr,
2530                            const char *buf, size_t count)
2531 {
2532         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2533
2534         return fsg_store_nofua(curlun, buf, count);
2535 }
2536
2537 static ssize_t file_store(struct device *dev, struct device_attribute *attr,
2538                           const char *buf, size_t count)
2539 {
2540         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2541         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2542
2543         return fsg_store_file(curlun, filesem, buf, count);
2544 }
2545
2546 static DEVICE_ATTR_RW(nofua);
2547 /* mode wil be set in fsg_lun_attr_is_visible() */
2548 static DEVICE_ATTR(ro, 0, ro_show, ro_store);
2549 static DEVICE_ATTR(file, 0, file_show, file_store);
2550
2551 /****************************** FSG COMMON ******************************/
2552
2553 static void fsg_lun_release(struct device *dev)
2554 {
2555         /* Nothing needs to be done */
2556 }
2557
2558 static struct fsg_common *fsg_common_setup(struct fsg_common *common)
2559 {
2560         if (!common) {
2561                 common = kzalloc(sizeof(*common), GFP_KERNEL);
2562                 if (!common)
2563                         return ERR_PTR(-ENOMEM);
2564                 common->free_storage_on_release = 1;
2565         } else {
2566                 common->free_storage_on_release = 0;
2567         }
2568         init_rwsem(&common->filesem);
2569         spin_lock_init(&common->lock);
2570         init_completion(&common->thread_notifier);
2571         init_waitqueue_head(&common->io_wait);
2572         init_waitqueue_head(&common->fsg_wait);
2573         common->state = FSG_STATE_TERMINATED;
2574         memset(common->luns, 0, sizeof(common->luns));
2575
2576         return common;
2577 }
2578
2579 void fsg_common_set_sysfs(struct fsg_common *common, bool sysfs)
2580 {
2581         common->sysfs = sysfs;
2582 }
2583 EXPORT_SYMBOL_GPL(fsg_common_set_sysfs);
2584
2585 static void _fsg_common_free_buffers(struct fsg_buffhd *buffhds, unsigned n)
2586 {
2587         if (buffhds) {
2588                 struct fsg_buffhd *bh = buffhds;
2589                 while (n--) {
2590                         kfree(bh->buf);
2591                         ++bh;
2592                 }
2593                 kfree(buffhds);
2594         }
2595 }
2596
2597 int fsg_common_set_num_buffers(struct fsg_common *common, unsigned int n)
2598 {
2599         struct fsg_buffhd *bh, *buffhds;
2600         int i;
2601
2602         buffhds = kcalloc(n, sizeof(*buffhds), GFP_KERNEL);
2603         if (!buffhds)
2604                 return -ENOMEM;
2605
2606         /* Data buffers cyclic list */
2607         bh = buffhds;
2608         i = n;
2609         goto buffhds_first_it;
2610         do {
2611                 bh->next = bh + 1;
2612                 ++bh;
2613 buffhds_first_it:
2614                 bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
2615                 if (unlikely(!bh->buf))
2616                         goto error_release;
2617         } while (--i);
2618         bh->next = buffhds;
2619
2620         _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);
2621         common->fsg_num_buffers = n;
2622         common->buffhds = buffhds;
2623
2624         return 0;
2625
2626 error_release:
2627         /*
2628          * "buf"s pointed to by heads after n - i are NULL
2629          * so releasing them won't hurt
2630          */
2631         _fsg_common_free_buffers(buffhds, n);
2632
2633         return -ENOMEM;
2634 }
2635 EXPORT_SYMBOL_GPL(fsg_common_set_num_buffers);
2636
2637 void fsg_common_remove_lun(struct fsg_lun *lun)
2638 {
2639         if (device_is_registered(&lun->dev))
2640                 device_unregister(&lun->dev);
2641         fsg_lun_close(lun);
2642         kfree(lun);
2643 }
2644 EXPORT_SYMBOL_GPL(fsg_common_remove_lun);
2645
2646 static void _fsg_common_remove_luns(struct fsg_common *common, int n)
2647 {
2648         int i;
2649
2650         for (i = 0; i < n; ++i)
2651                 if (common->luns[i]) {
2652                         fsg_common_remove_lun(common->luns[i]);
2653                         common->luns[i] = NULL;
2654                 }
2655 }
2656
2657 void fsg_common_remove_luns(struct fsg_common *common)
2658 {
2659         _fsg_common_remove_luns(common, ARRAY_SIZE(common->luns));
2660 }
2661 EXPORT_SYMBOL_GPL(fsg_common_remove_luns);
2662
2663 void fsg_common_free_buffers(struct fsg_common *common)
2664 {
2665         _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);
2666         common->buffhds = NULL;
2667 }
2668 EXPORT_SYMBOL_GPL(fsg_common_free_buffers);
2669
2670 int fsg_common_set_cdev(struct fsg_common *common,
2671                          struct usb_composite_dev *cdev, bool can_stall)
2672 {
2673         struct usb_string *us;
2674
2675         common->gadget = cdev->gadget;
2676         common->ep0 = cdev->gadget->ep0;
2677         common->ep0req = cdev->req;
2678         common->cdev = cdev;
2679
2680         us = usb_gstrings_attach(cdev, fsg_strings_array,
2681                                  ARRAY_SIZE(fsg_strings));
2682         if (IS_ERR(us))
2683                 return PTR_ERR(us);
2684
2685         fsg_intf_desc.iInterface = us[FSG_STRING_INTERFACE].id;
2686
2687         /*
2688          * Some peripheral controllers are known not to be able to
2689          * halt bulk endpoints correctly.  If one of them is present,
2690          * disable stalls.
2691          */
2692         common->can_stall = can_stall &&
2693                         gadget_is_stall_supported(common->gadget);
2694
2695         return 0;
2696 }
2697 EXPORT_SYMBOL_GPL(fsg_common_set_cdev);
2698
2699 static struct attribute *fsg_lun_dev_attrs[] = {
2700         &dev_attr_ro.attr,
2701         &dev_attr_file.attr,
2702         &dev_attr_nofua.attr,
2703         NULL
2704 };
2705
2706 static umode_t fsg_lun_dev_is_visible(struct kobject *kobj,
2707                                       struct attribute *attr, int idx)
2708 {
2709         struct device *dev = kobj_to_dev(kobj);
2710         struct fsg_lun *lun = fsg_lun_from_dev(dev);
2711
2712         if (attr == &dev_attr_ro.attr)
2713                 return lun->cdrom ? S_IRUGO : (S_IWUSR | S_IRUGO);
2714         if (attr == &dev_attr_file.attr)
2715                 return lun->removable ? (S_IWUSR | S_IRUGO) : S_IRUGO;
2716         return attr->mode;
2717 }
2718
2719 static const struct attribute_group fsg_lun_dev_group = {
2720         .attrs = fsg_lun_dev_attrs,
2721         .is_visible = fsg_lun_dev_is_visible,
2722 };
2723
2724 static const struct attribute_group *fsg_lun_dev_groups[] = {
2725         &fsg_lun_dev_group,
2726         NULL
2727 };
2728
2729 int fsg_common_create_lun(struct fsg_common *common, struct fsg_lun_config *cfg,
2730                           unsigned int id, const char *name,
2731                           const char **name_pfx)
2732 {
2733         struct fsg_lun *lun;
2734         char *pathbuf, *p;
2735         int rc = -ENOMEM;
2736
2737         if (id >= ARRAY_SIZE(common->luns))
2738                 return -ENODEV;
2739
2740         if (common->luns[id])
2741                 return -EBUSY;
2742
2743         if (!cfg->filename && !cfg->removable) {
2744                 pr_err("no file given for LUN%d\n", id);
2745                 return -EINVAL;
2746         }
2747
2748         lun = kzalloc(sizeof(*lun), GFP_KERNEL);
2749         if (!lun)
2750                 return -ENOMEM;
2751
2752         lun->name_pfx = name_pfx;
2753
2754         lun->cdrom = !!cfg->cdrom;
2755         lun->ro = cfg->cdrom || cfg->ro;
2756         lun->initially_ro = lun->ro;
2757         lun->removable = !!cfg->removable;
2758
2759         if (!common->sysfs) {
2760                 /* we DON'T own the name!*/
2761                 lun->name = name;
2762         } else {
2763                 lun->dev.release = fsg_lun_release;
2764                 lun->dev.parent = &common->gadget->dev;
2765                 lun->dev.groups = fsg_lun_dev_groups;
2766                 dev_set_drvdata(&lun->dev, &common->filesem);
2767                 dev_set_name(&lun->dev, "%s", name);
2768                 lun->name = dev_name(&lun->dev);
2769
2770                 rc = device_register(&lun->dev);
2771                 if (rc) {
2772                         pr_info("failed to register LUN%d: %d\n", id, rc);
2773                         put_device(&lun->dev);
2774                         goto error_sysfs;
2775                 }
2776         }
2777
2778         common->luns[id] = lun;
2779
2780         if (cfg->filename) {
2781                 rc = fsg_lun_open(lun, cfg->filename);
2782                 if (rc)
2783                         goto error_lun;
2784         }
2785
2786         pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
2787         p = "(no medium)";
2788         if (fsg_lun_is_open(lun)) {
2789                 p = "(error)";
2790                 if (pathbuf) {
2791                         p = file_path(lun->filp, pathbuf, PATH_MAX);
2792                         if (IS_ERR(p))
2793                                 p = "(error)";
2794                 }
2795         }
2796         pr_info("LUN: %s%s%sfile: %s\n",
2797               lun->removable ? "removable " : "",
2798               lun->ro ? "read only " : "",
2799               lun->cdrom ? "CD-ROM " : "",
2800               p);
2801         kfree(pathbuf);
2802
2803         return 0;
2804
2805 error_lun:
2806         if (device_is_registered(&lun->dev))
2807                 device_unregister(&lun->dev);
2808         fsg_lun_close(lun);
2809         common->luns[id] = NULL;
2810 error_sysfs:
2811         kfree(lun);
2812         return rc;
2813 }
2814 EXPORT_SYMBOL_GPL(fsg_common_create_lun);
2815
2816 int fsg_common_create_luns(struct fsg_common *common, struct fsg_config *cfg)
2817 {
2818         char buf[8]; /* enough for 100000000 different numbers, decimal */
2819         int i, rc;
2820
2821         fsg_common_remove_luns(common);
2822
2823         for (i = 0; i < cfg->nluns; ++i) {
2824                 snprintf(buf, sizeof(buf), "lun%d", i);
2825                 rc = fsg_common_create_lun(common, &cfg->luns[i], i, buf, NULL);
2826                 if (rc)
2827                         goto fail;
2828         }
2829
2830         pr_info("Number of LUNs=%d\n", cfg->nluns);
2831
2832         return 0;
2833
2834 fail:
2835         _fsg_common_remove_luns(common, i);
2836         return rc;
2837 }
2838 EXPORT_SYMBOL_GPL(fsg_common_create_luns);
2839
2840 void fsg_common_set_inquiry_string(struct fsg_common *common, const char *vn,
2841                                    const char *pn)
2842 {
2843         int i;
2844
2845         /* Prepare inquiryString */
2846         i = get_default_bcdDevice();
2847         snprintf(common->inquiry_string, sizeof(common->inquiry_string),
2848                  "%-8s%-16s%04x", vn ?: "Linux",
2849                  /* Assume product name dependent on the first LUN */
2850                  pn ?: ((*common->luns)->cdrom
2851                      ? "File-CD Gadget"
2852                      : "File-Stor Gadget"),
2853                  i);
2854 }
2855 EXPORT_SYMBOL_GPL(fsg_common_set_inquiry_string);
2856
2857 static void fsg_common_release(struct fsg_common *common)
2858 {
2859         int i;
2860
2861         /* If the thread isn't already dead, tell it to exit now */
2862         if (common->state != FSG_STATE_TERMINATED) {
2863                 raise_exception(common, FSG_STATE_EXIT);
2864                 wait_for_completion(&common->thread_notifier);
2865         }
2866
2867         for (i = 0; i < ARRAY_SIZE(common->luns); ++i) {
2868                 struct fsg_lun *lun = common->luns[i];
2869                 if (!lun)
2870                         continue;
2871                 fsg_lun_close(lun);
2872                 if (device_is_registered(&lun->dev))
2873                         device_unregister(&lun->dev);
2874                 kfree(lun);
2875         }
2876
2877         _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);
2878         if (common->free_storage_on_release)
2879                 kfree(common);
2880 }
2881
2882
2883 /*-------------------------------------------------------------------------*/
2884
2885 static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
2886 {
2887         struct fsg_dev          *fsg = fsg_from_func(f);
2888         struct fsg_common       *common = fsg->common;
2889         struct usb_gadget       *gadget = c->cdev->gadget;
2890         int                     i;
2891         struct usb_ep           *ep;
2892         unsigned                max_burst;
2893         int                     ret;
2894         struct fsg_opts         *opts;
2895
2896         /* Don't allow to bind if we don't have at least one LUN */
2897         ret = _fsg_common_get_max_lun(common);
2898         if (ret < 0) {
2899                 pr_err("There should be at least one LUN.\n");
2900                 return -EINVAL;
2901         }
2902
2903         opts = fsg_opts_from_func_inst(f->fi);
2904         if (!opts->no_configfs) {
2905                 ret = fsg_common_set_cdev(fsg->common, c->cdev,
2906                                           fsg->common->can_stall);
2907                 if (ret)
2908                         return ret;
2909                 fsg_common_set_inquiry_string(fsg->common, NULL, NULL);
2910         }
2911
2912         if (!common->thread_task) {
2913                 common->state = FSG_STATE_NORMAL;
2914                 common->thread_task =
2915                         kthread_create(fsg_main_thread, common, "file-storage");
2916                 if (IS_ERR(common->thread_task)) {
2917                         ret = PTR_ERR(common->thread_task);
2918                         common->thread_task = NULL;
2919                         common->state = FSG_STATE_TERMINATED;
2920                         return ret;
2921                 }
2922                 DBG(common, "I/O thread pid: %d\n",
2923                     task_pid_nr(common->thread_task));
2924                 wake_up_process(common->thread_task);
2925         }
2926
2927         fsg->gadget = gadget;
2928
2929         /* New interface */
2930         i = usb_interface_id(c, f);
2931         if (i < 0)
2932                 goto fail;
2933         fsg_intf_desc.bInterfaceNumber = i;
2934         fsg->interface_number = i;
2935
2936         /* Find all the endpoints we will use */
2937         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
2938         if (!ep)
2939                 goto autoconf_fail;
2940         fsg->bulk_in = ep;
2941
2942         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
2943         if (!ep)
2944                 goto autoconf_fail;
2945         fsg->bulk_out = ep;
2946
2947         /* Assume endpoint addresses are the same for both speeds */
2948         fsg_hs_bulk_in_desc.bEndpointAddress =
2949                 fsg_fs_bulk_in_desc.bEndpointAddress;
2950         fsg_hs_bulk_out_desc.bEndpointAddress =
2951                 fsg_fs_bulk_out_desc.bEndpointAddress;
2952
2953         /* Calculate bMaxBurst, we know packet size is 1024 */
2954         max_burst = min_t(unsigned, FSG_BUFLEN / 1024, 15);
2955
2956         fsg_ss_bulk_in_desc.bEndpointAddress =
2957                 fsg_fs_bulk_in_desc.bEndpointAddress;
2958         fsg_ss_bulk_in_comp_desc.bMaxBurst = max_burst;
2959
2960         fsg_ss_bulk_out_desc.bEndpointAddress =
2961                 fsg_fs_bulk_out_desc.bEndpointAddress;
2962         fsg_ss_bulk_out_comp_desc.bMaxBurst = max_burst;
2963
2964         ret = usb_assign_descriptors(f, fsg_fs_function, fsg_hs_function,
2965                         fsg_ss_function, fsg_ss_function);
2966         if (ret)
2967                 goto autoconf_fail;
2968
2969         return 0;
2970
2971 autoconf_fail:
2972         ERROR(fsg, "unable to autoconfigure all endpoints\n");
2973         i = -ENOTSUPP;
2974 fail:
2975         /* terminate the thread */
2976         if (fsg->common->state != FSG_STATE_TERMINATED) {
2977                 raise_exception(fsg->common, FSG_STATE_EXIT);
2978                 wait_for_completion(&fsg->common->thread_notifier);
2979         }
2980         return i;
2981 }
2982
2983 /****************************** ALLOCATE FUNCTION *************************/
2984
2985 static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
2986 {
2987         struct fsg_dev          *fsg = fsg_from_func(f);
2988         struct fsg_common       *common = fsg->common;
2989
2990         DBG(fsg, "unbind\n");
2991         if (fsg->common->fsg == fsg) {
2992                 fsg->common->new_fsg = NULL;
2993                 raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2994                 /* FIXME: make interruptible or killable somehow? */
2995                 wait_event(common->fsg_wait, common->fsg != fsg);
2996         }
2997
2998         usb_free_all_descriptors(&fsg->function);
2999 }
3000
3001 static inline struct fsg_lun_opts *to_fsg_lun_opts(struct config_item *item)
3002 {
3003         return container_of(to_config_group(item), struct fsg_lun_opts, group);
3004 }
3005
3006 static inline struct fsg_opts *to_fsg_opts(struct config_item *item)
3007 {
3008         return container_of(to_config_group(item), struct fsg_opts,
3009                             func_inst.group);
3010 }
3011
3012 static void fsg_lun_attr_release(struct config_item *item)
3013 {
3014         struct fsg_lun_opts *lun_opts;
3015
3016         lun_opts = to_fsg_lun_opts(item);
3017         kfree(lun_opts);
3018 }
3019
3020 static struct configfs_item_operations fsg_lun_item_ops = {
3021         .release                = fsg_lun_attr_release,
3022 };
3023
3024 static ssize_t fsg_lun_opts_file_show(struct config_item *item, char *page)
3025 {
3026         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3027         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3028
3029         return fsg_show_file(opts->lun, &fsg_opts->common->filesem, page);
3030 }
3031
3032 static ssize_t fsg_lun_opts_file_store(struct config_item *item,
3033                                        const char *page, size_t len)
3034 {
3035         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3036         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3037
3038         return fsg_store_file(opts->lun, &fsg_opts->common->filesem, page, len);
3039 }
3040
3041 CONFIGFS_ATTR(fsg_lun_opts_, file);
3042
3043 static ssize_t fsg_lun_opts_ro_show(struct config_item *item, char *page)
3044 {
3045         return fsg_show_ro(to_fsg_lun_opts(item)->lun, page);
3046 }
3047
3048 static ssize_t fsg_lun_opts_ro_store(struct config_item *item,
3049                                        const char *page, size_t len)
3050 {
3051         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3052         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3053
3054         return fsg_store_ro(opts->lun, &fsg_opts->common->filesem, page, len);
3055 }
3056
3057 CONFIGFS_ATTR(fsg_lun_opts_, ro);
3058
3059 static ssize_t fsg_lun_opts_removable_show(struct config_item *item,
3060                                            char *page)
3061 {
3062         return fsg_show_removable(to_fsg_lun_opts(item)->lun, page);
3063 }
3064
3065 static ssize_t fsg_lun_opts_removable_store(struct config_item *item,
3066                                        const char *page, size_t len)
3067 {
3068         return fsg_store_removable(to_fsg_lun_opts(item)->lun, page, len);
3069 }
3070
3071 CONFIGFS_ATTR(fsg_lun_opts_, removable);
3072
3073 static ssize_t fsg_lun_opts_cdrom_show(struct config_item *item, char *page)
3074 {
3075         return fsg_show_cdrom(to_fsg_lun_opts(item)->lun, page);
3076 }
3077
3078 static ssize_t fsg_lun_opts_cdrom_store(struct config_item *item,
3079                                        const char *page, size_t len)
3080 {
3081         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3082         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3083
3084         return fsg_store_cdrom(opts->lun, &fsg_opts->common->filesem, page,
3085                                len);
3086 }
3087
3088 CONFIGFS_ATTR(fsg_lun_opts_, cdrom);
3089
3090 static ssize_t fsg_lun_opts_nofua_show(struct config_item *item, char *page)
3091 {
3092         return fsg_show_nofua(to_fsg_lun_opts(item)->lun, page);
3093 }
3094
3095 static ssize_t fsg_lun_opts_nofua_store(struct config_item *item,
3096                                        const char *page, size_t len)
3097 {
3098         return fsg_store_nofua(to_fsg_lun_opts(item)->lun, page, len);
3099 }
3100
3101 CONFIGFS_ATTR(fsg_lun_opts_, nofua);
3102
3103 static ssize_t fsg_lun_opts_inquiry_string_show(struct config_item *item,
3104                                                 char *page)
3105 {
3106         return fsg_show_inquiry_string(to_fsg_lun_opts(item)->lun, page);
3107 }
3108
3109 static ssize_t fsg_lun_opts_inquiry_string_store(struct config_item *item,
3110                                                  const char *page, size_t len)
3111 {
3112         return fsg_store_inquiry_string(to_fsg_lun_opts(item)->lun, page, len);
3113 }
3114
3115 CONFIGFS_ATTR(fsg_lun_opts_, inquiry_string);
3116
3117 static struct configfs_attribute *fsg_lun_attrs[] = {
3118         &fsg_lun_opts_attr_file,
3119         &fsg_lun_opts_attr_ro,
3120         &fsg_lun_opts_attr_removable,
3121         &fsg_lun_opts_attr_cdrom,
3122         &fsg_lun_opts_attr_nofua,
3123         &fsg_lun_opts_attr_inquiry_string,
3124         NULL,
3125 };
3126
3127 static const struct config_item_type fsg_lun_type = {
3128         .ct_item_ops    = &fsg_lun_item_ops,
3129         .ct_attrs       = fsg_lun_attrs,
3130         .ct_owner       = THIS_MODULE,
3131 };
3132
3133 static struct config_group *fsg_lun_make(struct config_group *group,
3134                                          const char *name)
3135 {
3136         struct fsg_lun_opts *opts;
3137         struct fsg_opts *fsg_opts;
3138         struct fsg_lun_config config;
3139         char *num_str;
3140         u8 num;
3141         int ret;
3142
3143         num_str = strchr(name, '.');
3144         if (!num_str) {
3145                 pr_err("Unable to locate . in LUN.NUMBER\n");
3146                 return ERR_PTR(-EINVAL);
3147         }
3148         num_str++;
3149
3150         ret = kstrtou8(num_str, 0, &num);
3151         if (ret)
3152                 return ERR_PTR(ret);
3153
3154         fsg_opts = to_fsg_opts(&group->cg_item);
3155         if (num >= FSG_MAX_LUNS)
3156                 return ERR_PTR(-ERANGE);
3157         num = array_index_nospec(num, FSG_MAX_LUNS);
3158
3159         mutex_lock(&fsg_opts->lock);
3160         if (fsg_opts->refcnt || fsg_opts->common->luns[num]) {
3161                 ret = -EBUSY;
3162                 goto out;
3163         }
3164
3165         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3166         if (!opts) {
3167                 ret = -ENOMEM;
3168                 goto out;
3169         }
3170
3171         memset(&config, 0, sizeof(config));
3172         config.removable = true;
3173
3174         ret = fsg_common_create_lun(fsg_opts->common, &config, num, name,
3175                                     (const char **)&group->cg_item.ci_name);
3176         if (ret) {
3177                 kfree(opts);
3178                 goto out;
3179         }
3180         opts->lun = fsg_opts->common->luns[num];
3181         opts->lun_id = num;
3182         mutex_unlock(&fsg_opts->lock);
3183
3184         config_group_init_type_name(&opts->group, name, &fsg_lun_type);
3185
3186         return &opts->group;
3187 out:
3188         mutex_unlock(&fsg_opts->lock);
3189         return ERR_PTR(ret);
3190 }
3191
3192 static void fsg_lun_drop(struct config_group *group, struct config_item *item)
3193 {
3194         struct fsg_lun_opts *lun_opts;
3195         struct fsg_opts *fsg_opts;
3196
3197         lun_opts = to_fsg_lun_opts(item);
3198         fsg_opts = to_fsg_opts(&group->cg_item);
3199
3200         mutex_lock(&fsg_opts->lock);
3201         if (fsg_opts->refcnt) {
3202                 struct config_item *gadget;
3203
3204                 gadget = group->cg_item.ci_parent->ci_parent;
3205                 unregister_gadget_item(gadget);
3206         }
3207
3208         fsg_common_remove_lun(lun_opts->lun);
3209         fsg_opts->common->luns[lun_opts->lun_id] = NULL;
3210         lun_opts->lun_id = 0;
3211         mutex_unlock(&fsg_opts->lock);
3212
3213         config_item_put(item);
3214 }
3215
3216 static void fsg_attr_release(struct config_item *item)
3217 {
3218         struct fsg_opts *opts = to_fsg_opts(item);
3219
3220         usb_put_function_instance(&opts->func_inst);
3221 }
3222
3223 static struct configfs_item_operations fsg_item_ops = {
3224         .release                = fsg_attr_release,
3225 };
3226
3227 static ssize_t fsg_opts_stall_show(struct config_item *item, char *page)
3228 {
3229         struct fsg_opts *opts = to_fsg_opts(item);
3230         int result;
3231
3232         mutex_lock(&opts->lock);
3233         result = sprintf(page, "%d", opts->common->can_stall);
3234         mutex_unlock(&opts->lock);
3235
3236         return result;
3237 }
3238
3239 static ssize_t fsg_opts_stall_store(struct config_item *item, const char *page,
3240                                     size_t len)
3241 {
3242         struct fsg_opts *opts = to_fsg_opts(item);
3243         int ret;
3244         bool stall;
3245
3246         mutex_lock(&opts->lock);
3247
3248         if (opts->refcnt) {
3249                 mutex_unlock(&opts->lock);
3250                 return -EBUSY;
3251         }
3252
3253         ret = strtobool(page, &stall);
3254         if (!ret) {
3255                 opts->common->can_stall = stall;
3256                 ret = len;
3257         }
3258
3259         mutex_unlock(&opts->lock);
3260
3261         return ret;
3262 }
3263
3264 CONFIGFS_ATTR(fsg_opts_, stall);
3265
3266 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
3267 static ssize_t fsg_opts_num_buffers_show(struct config_item *item, char *page)
3268 {
3269         struct fsg_opts *opts = to_fsg_opts(item);
3270         int result;
3271
3272         mutex_lock(&opts->lock);
3273         result = sprintf(page, "%d", opts->common->fsg_num_buffers);
3274         mutex_unlock(&opts->lock);
3275
3276         return result;
3277 }
3278
3279 static ssize_t fsg_opts_num_buffers_store(struct config_item *item,
3280                                           const char *page, size_t len)
3281 {
3282         struct fsg_opts *opts = to_fsg_opts(item);
3283         int ret;
3284         u8 num;
3285
3286         mutex_lock(&opts->lock);
3287         if (opts->refcnt) {
3288                 ret = -EBUSY;
3289                 goto end;
3290         }
3291         ret = kstrtou8(page, 0, &num);
3292         if (ret)
3293                 goto end;
3294
3295         ret = fsg_common_set_num_buffers(opts->common, num);
3296         if (ret)
3297                 goto end;
3298         ret = len;
3299
3300 end:
3301         mutex_unlock(&opts->lock);
3302         return ret;
3303 }
3304
3305 CONFIGFS_ATTR(fsg_opts_, num_buffers);
3306 #endif
3307
3308 static struct configfs_attribute *fsg_attrs[] = {
3309         &fsg_opts_attr_stall,
3310 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
3311         &fsg_opts_attr_num_buffers,
3312 #endif
3313         NULL,
3314 };
3315
3316 static struct configfs_group_operations fsg_group_ops = {
3317         .make_group     = fsg_lun_make,
3318         .drop_item      = fsg_lun_drop,
3319 };
3320
3321 static const struct config_item_type fsg_func_type = {
3322         .ct_item_ops    = &fsg_item_ops,
3323         .ct_group_ops   = &fsg_group_ops,
3324         .ct_attrs       = fsg_attrs,
3325         .ct_owner       = THIS_MODULE,
3326 };
3327
3328 static void fsg_free_inst(struct usb_function_instance *fi)
3329 {
3330         struct fsg_opts *opts;
3331
3332         opts = fsg_opts_from_func_inst(fi);
3333         fsg_common_release(opts->common);
3334         kfree(opts);
3335 }
3336
3337 static struct usb_function_instance *fsg_alloc_inst(void)
3338 {
3339         struct fsg_opts *opts;
3340         struct fsg_lun_config config;
3341         int rc;
3342
3343         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3344         if (!opts)
3345                 return ERR_PTR(-ENOMEM);
3346         mutex_init(&opts->lock);
3347         opts->func_inst.free_func_inst = fsg_free_inst;
3348         opts->common = fsg_common_setup(opts->common);
3349         if (IS_ERR(opts->common)) {
3350                 rc = PTR_ERR(opts->common);
3351                 goto release_opts;
3352         }
3353
3354         rc = fsg_common_set_num_buffers(opts->common,
3355                                         CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS);
3356         if (rc)
3357                 goto release_common;
3358
3359         pr_info(FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
3360
3361         memset(&config, 0, sizeof(config));
3362         config.removable = true;
3363         rc = fsg_common_create_lun(opts->common, &config, 0, "lun.0",
3364                         (const char **)&opts->func_inst.group.cg_item.ci_name);
3365         if (rc)
3366                 goto release_buffers;
3367
3368         opts->lun0.lun = opts->common->luns[0];
3369         opts->lun0.lun_id = 0;
3370
3371         config_group_init_type_name(&opts->func_inst.group, "", &fsg_func_type);
3372
3373         config_group_init_type_name(&opts->lun0.group, "lun.0", &fsg_lun_type);
3374         configfs_add_default_group(&opts->lun0.group, &opts->func_inst.group);
3375
3376         return &opts->func_inst;
3377
3378 release_buffers:
3379         fsg_common_free_buffers(opts->common);
3380 release_common:
3381         kfree(opts->common);
3382 release_opts:
3383         kfree(opts);
3384         return ERR_PTR(rc);
3385 }
3386
3387 static void fsg_free(struct usb_function *f)
3388 {
3389         struct fsg_dev *fsg;
3390         struct fsg_opts *opts;
3391
3392         fsg = container_of(f, struct fsg_dev, function);
3393         opts = container_of(f->fi, struct fsg_opts, func_inst);
3394
3395         mutex_lock(&opts->lock);
3396         opts->refcnt--;
3397         mutex_unlock(&opts->lock);
3398
3399         kfree(fsg);
3400 }
3401
3402 static struct usb_function *fsg_alloc(struct usb_function_instance *fi)
3403 {
3404         struct fsg_opts *opts = fsg_opts_from_func_inst(fi);
3405         struct fsg_common *common = opts->common;
3406         struct fsg_dev *fsg;
3407
3408         fsg = kzalloc(sizeof(*fsg), GFP_KERNEL);
3409         if (unlikely(!fsg))
3410                 return ERR_PTR(-ENOMEM);
3411
3412         mutex_lock(&opts->lock);
3413         opts->refcnt++;
3414         mutex_unlock(&opts->lock);
3415
3416         fsg->function.name      = FSG_DRIVER_DESC;
3417         fsg->function.bind      = fsg_bind;
3418         fsg->function.unbind    = fsg_unbind;
3419         fsg->function.setup     = fsg_setup;
3420         fsg->function.set_alt   = fsg_set_alt;
3421         fsg->function.disable   = fsg_disable;
3422         fsg->function.free_func = fsg_free;
3423
3424         fsg->common               = common;
3425
3426         return &fsg->function;
3427 }
3428
3429 DECLARE_USB_FUNCTION_INIT(mass_storage, fsg_alloc_inst, fsg_alloc);
3430 MODULE_LICENSE("GPL");
3431 MODULE_AUTHOR("Michal Nazarewicz");
3432
3433 /************************* Module parameters *************************/
3434
3435
3436 void fsg_config_from_params(struct fsg_config *cfg,
3437                        const struct fsg_module_parameters *params,
3438                        unsigned int fsg_num_buffers)
3439 {
3440         struct fsg_lun_config *lun;
3441         unsigned i;
3442
3443         /* Configure LUNs */
3444         cfg->nluns =
3445                 min(params->luns ?: (params->file_count ?: 1u),
3446                     (unsigned)FSG_MAX_LUNS);
3447         for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) {
3448                 lun->ro = !!params->ro[i];
3449                 lun->cdrom = !!params->cdrom[i];
3450                 lun->removable = !!params->removable[i];
3451                 lun->filename =
3452                         params->file_count > i && params->file[i][0]
3453                         ? params->file[i]
3454                         : NULL;
3455         }
3456
3457         /* Let MSF use defaults */
3458         cfg->vendor_name = NULL;
3459         cfg->product_name = NULL;
3460
3461         cfg->ops = NULL;
3462         cfg->private_data = NULL;
3463
3464         /* Finalise */
3465         cfg->can_stall = params->stall;
3466         cfg->fsg_num_buffers = fsg_num_buffers;
3467 }
3468 EXPORT_SYMBOL_GPL(fsg_config_from_params);