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
  11 /*
  12  * The Mass Storage Function acts as a USB Mass Storage device,
  13  * appearing to the host as a disk drive or as a CD-ROM drive.  In
  14  * addition to providing an example of a genuinely useful composite
  15  * function for a USB device, it also illustrates a technique of
  16  * double-buffering for increased throughput.
  17  *
  18  * For more information about MSF and in particular its module
  19  * parameters and sysfs interface read the
  20  * <Documentation/usb/mass-storage.rst> file.
  21  */
  22
  23 /*
  24  * MSF is configured by specifying a fsg_config structure.  It has the
  25  * following fields:
  26  *
  27  *      nluns           Number of LUNs function have (anywhere from 1
  28  *                              to FSG_MAX_LUNS).
  29  *      luns            An array of LUN configuration values.  This
  30  *                              should be filled for each LUN that
  31  *                              function will include (ie. for "nluns"
  32  *                              LUNs).  Each element of the array has
  33  *                              the following fields:
  34  *      ->filename      The path to the backing file for the LUN.
  35  *                              Required if LUN is not marked as
  36  *                              removable.
  37  *      ->ro            Flag specifying access to the LUN shall be
  38  *                              read-only.  This is implied if CD-ROM
  39  *                              emulation is enabled as well as when
  40  *                              it was impossible to open "filename"
  41  *                              in R/W mode.
  42  *      ->removable     Flag specifying that LUN shall be indicated as
  43  *                              being removable.
  44  *      ->cdrom         Flag specifying that LUN shall be reported as
  45  *                              being a CD-ROM.
  46  *      ->nofua         Flag specifying that FUA flag in SCSI WRITE(10,12)
  47  *                              commands for this LUN shall be ignored.
  48  *
  49  *      vendor_name
  50  *      product_name
  51  *      release         Information used as a reply to INQUIRY
  52  *                              request.  To use default set to NULL,
  53  *                              NULL, 0xffff respectively.  The first
  54  *                              field should be 8 and the second 16
  55  *                              characters or less.
  56  *
  57  *      can_stall       Set to permit function to halt bulk endpoints.
  58  *                              Disabled on some USB devices known not
  59  *                              to work correctly.  You should set it
  60  *                              to true.
  61  *
  62  * If "removable" is not set for a LUN then a backing file must be
  63  * specified.  If it is set, then NULL filename means the LUN's medium
  64  * is not loaded (an empty string as "filename" in the fsg_config
  65  * structure causes error).  The CD-ROM emulation includes a single
  66  * data track and no audio tracks; hence there need be only one
  67  * backing file per LUN.
  68  *
  69  * This function is heavily based on "File-backed Storage Gadget" by
  70  * Alan Stern which in turn is heavily based on "Gadget Zero" by David
  71  * Brownell.  The driver's SCSI command interface was based on the
  72  * "Information technology - Small Computer System Interface - 2"
  73  * document from X3T9.2 Project 375D, Revision 10L, 7-SEP-93,
  74  * available at <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.
  75  * The single exception is opcode 0x23 (READ FORMAT CAPACITIES), which
  76  * was based on the "Universal Serial Bus Mass Storage Class UFI
  77  * Command Specification" document, Revision 1.0, December 14, 1998,
  78  * available at
  79  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
  80  */
  81
  82 /*
  83  *                              Driver Design
  84  *
  85  * The MSF is fairly straightforward.  There is a main kernel
  86  * thread that handles most of the work.  Interrupt routines field
  87  * callbacks from the controller driver: bulk- and interrupt-request
  88  * completion notifications, endpoint-0 events, and disconnect events.
  89  * Completion events are passed to the main thread by wakeup calls.  Many
  90  * ep0 requests are handled at interrupt time, but SetInterface,
  91  * SetConfiguration, and device reset requests are forwarded to the
  92  * thread in the form of "exceptions" using SIGUSR1 signals (since they
  93  * should interrupt any ongoing file I/O operations).
  94  *
  95  * The thread's main routine implements the standard command/data/status
  96  * parts of a SCSI interaction.  It and its subroutines are full of tests
  97  * for pending signals/exceptions -- all this polling is necessary since
  98  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
  99  * indication that the driver really wants to be running in userspace.)
 100  * An important point is that so long as the thread is alive it keeps an
 101  * open reference to the backing file.  This will prevent unmounting
 102  * the backing file's underlying filesystem and could cause problems
 103  * during system shutdown, for example.  To prevent such problems, the
 104  * thread catches INT, TERM, and KILL signals and converts them into
 105  * an EXIT exception.
 106  *
 107  * In normal operation the main thread is started during the gadget's
 108  * fsg_bind() callback and stopped during fsg_unbind().  But it can
 109  * also exit when it receives a signal, and there's no point leaving
 110  * the gadget running when the thread is dead.  As of this moment, MSF
 111  * provides no way to deregister the gadget when thread dies -- maybe
 112  * a callback functions is needed.
 113  *
 114  * To provide maximum throughput, the driver uses a circular pipeline of
 115  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
 116  * arbitrarily long; in practice the benefits don't justify having more
 117  * than 2 stages (i.e., double buffering).  But it helps to think of the
 118  * pipeline as being a long one.  Each buffer head contains a bulk-in and
 119  * a bulk-out request pointer (since the buffer can be used for both
 120  * output and input -- directions always are given from the host's
 121  * point of view) as well as a pointer to the buffer and various state
 122  * variables.
 123  *
 124  * Use of the pipeline follows a simple protocol.  There is a variable
 125  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
 126  * At any time that buffer head may still be in use from an earlier
 127  * request, so each buffer head has a state variable indicating whether
 128  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
 129  * buffer head to be EMPTY, filling the buffer either by file I/O or by
 130  * USB I/O (during which the buffer head is BUSY), and marking the buffer
 131  * head FULL when the I/O is complete.  Then the buffer will be emptied
 132  * (again possibly by USB I/O, during which it is marked BUSY) and
 133  * finally marked EMPTY again (possibly by a completion routine).
 134  *
 135  * A module parameter tells the driver to avoid stalling the bulk
 136  * endpoints wherever the transport specification allows.  This is
 137  * necessary for some UDCs like the SuperH, which cannot reliably clear a
 138  * halt on a bulk endpoint.  However, under certain circumstances the
 139  * Bulk-only specification requires a stall.  In such cases the driver
 140  * will halt the endpoint and set a flag indicating that it should clear
 141  * the halt in software during the next device reset.  Hopefully this
 142  * will permit everything to work correctly.  Furthermore, although the
 143  * specification allows the bulk-out endpoint to halt when the host sends
 144  * too much data, implementing this would cause an unavoidable race.
 145  * The driver will always use the "no-stall" approach for OUT transfers.
 146  *
 147  * One subtle point concerns sending status-stage responses for ep0
 148  * requests.  Some of these requests, such as device reset, can involve
 149  * interrupting an ongoing file I/O operation, which might take an
 150  * arbitrarily long time.  During that delay the host might give up on
 151  * the original ep0 request and issue a new one.  When that happens the
 152  * driver should not notify the host about completion of the original
 153  * request, as the host will no longer be waiting for it.  So the driver
 154  * assigns to each ep0 request a unique tag, and it keeps track of the
 155  * tag value of the request associated with a long-running exception
 156  * (device-reset, interface-change, or configuration-change).  When the
 157  * exception handler is finished, the status-stage response is submitted
 158  * only if the current ep0 request tag is equal to the exception request
 159  * tag.  Thus only the most recently received ep0 request will get a
 160  * status-stage response.
 161  *
 162  * Warning: This driver source file is too long.  It ought to be split up
 163  * into a header file plus about 3 separate .c files, to handle the details
 164  * of the Gadget, USB Mass Storage, and SCSI protocols.
 165  */
 166
 167
 168 /* #define VERBOSE_DEBUG */
 169 /* #define DUMP_MSGS */
 170
 171 #include <linux/blkdev.h>
 172 #include <linux/completion.h>
 173 #include <linux/dcache.h>
 174 #include <linux/delay.h>
 175 #include <linux/device.h>
 176 #include <linux/fcntl.h>
 177 #include <linux/file.h>
 178 #include <linux/fs.h>
 179 #include <linux/kstrtox.h>
 180 #include <linux/kthread.h>
 181 #include <linux/sched/signal.h>
 182 #include <linux/limits.h>
 183 #include <linux/pagemap.h>
 184 #include <linux/rwsem.h>
 185 #include <linux/slab.h>
 186 #include <linux/spinlock.h>
 187 #include <linux/string.h>
 188 #include <linux/freezer.h>
 189 #include <linux/module.h>
 190 #include <linux/uaccess.h>
 191 #include <asm/unaligned.h>
 192
 193 #include <linux/usb/ch9.h>
 194 #include <linux/usb/gadget.h>
 195 #include <linux/usb/composite.h>
 196
 197 #include <linux/nospec.h>
 198
 199 #include "configfs.h"
 200
 201
 202 /*------------------------------------------------------------------------*/
 203
 204 #define FSG_DRIVER_DESC         "Mass Storage Function"
 205 #define FSG_DRIVER_VERSION      "2009/09/11"
 206
 207 static const char fsg_string_interface[] = "Mass Storage";
 208
 209 #include "storage_common.h"
 210 #include "f_mass_storage.h"
 211
 212 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
 213 static struct usb_string                fsg_strings[] = {
 214         {FSG_STRING_INTERFACE,          fsg_string_interface},
 215         {}
 216 };
 217
 218 static struct usb_gadget_strings        fsg_stringtab = {
 219         .language       = 0x0409,               /* en-us */
 220         .strings        = fsg_strings,
 221 };
 222
 223 static struct usb_gadget_strings *fsg_strings_array[] = {
 224         &fsg_stringtab,
 225         NULL,
 226 };
 227
 228 /*-------------------------------------------------------------------------*/
 229
 230 struct fsg_dev;
 231 struct fsg_common;
 232
 233 /* Data shared by all the FSG instances. */
 234 struct fsg_common {
 235         struct usb_gadget       *gadget;
 236         struct usb_composite_dev *cdev;
 237         struct fsg_dev          *fsg;
 238         wait_queue_head_t       io_wait;
 239         wait_queue_head_t       fsg_wait;
 240
 241         /* filesem protects: backing files in use */
 242         struct rw_semaphore     filesem;
 243
 244         /* lock protects: state and thread_task */
 245         spinlock_t              lock;
 246
 247         struct usb_ep           *ep0;           /* Copy of gadget->ep0 */
 248         struct usb_request      *ep0req;        /* Copy of cdev->req */
 249         unsigned int            ep0_req_tag;
 250
 251         struct fsg_buffhd       *next_buffhd_to_fill;
 252         struct fsg_buffhd       *next_buffhd_to_drain;
 253         struct fsg_buffhd       *buffhds;
 254         unsigned int            fsg_num_buffers;
 255
 256         int                     cmnd_size;
 257         u8                      cmnd[MAX_COMMAND_SIZE];
 258
 259         unsigned int            lun;
 260         struct fsg_lun          *luns[FSG_MAX_LUNS];
 261         struct fsg_lun          *curlun;
 262
 263         unsigned int            bulk_out_maxpacket;
 264         enum fsg_state          state;          /* For exception handling */
 265         unsigned int            exception_req_tag;
 266         void                    *exception_arg;
 267
 268         enum data_direction     data_dir;
 269         u32                     data_size;
 270         u32                     data_size_from_cmnd;
 271         u32                     tag;
 272         u32                     residue;
 273         u32                     usb_amount_left;
 274
 275         unsigned int            can_stall:1;
 276         unsigned int            free_storage_on_release:1;
 277         unsigned int            phase_error:1;
 278         unsigned int            short_packet_received:1;
 279         unsigned int            bad_lun_okay:1;
 280         unsigned int            running:1;
 281         unsigned int            sysfs:1;
 282
 283         struct completion       thread_notifier;
 284         struct task_struct      *thread_task;
 285
 286         /* Gadget's private data. */
 287         void                    *private_data;
 288
 289         char inquiry_string[INQUIRY_STRING_LEN];
 290 };
 291
 292 struct fsg_dev {
 293         struct usb_function     function;
 294         struct usb_gadget       *gadget;        /* Copy of cdev->gadget */
 295         struct fsg_common       *common;
 296
 297         u16                     interface_number;
 298
 299         unsigned int            bulk_in_enabled:1;
 300         unsigned int            bulk_out_enabled:1;
 301
 302         unsigned long           atomic_bitflags;
 303 #define IGNORE_BULK_OUT         0
 304
 305         struct usb_ep           *bulk_in;
 306         struct usb_ep           *bulk_out;
 307 };
 308
 309 static inline int __fsg_is_set(struct fsg_common *common,
 310                                const char *func, unsigned line)
 311 {
 312         if (common->fsg)
 313                 return 1;
 314         ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
 315         WARN_ON(1);
 316         return 0;
 317 }
 318
 319 #define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
 320
 321 static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
 322 {
 323         return container_of(f, struct fsg_dev, function);
 324 }
 325
 326 static int exception_in_progress(struct fsg_common *common)
 327 {
 328         return common->state > FSG_STATE_NORMAL;
 329 }
 330
 331 /* Make bulk-out requests be divisible by the maxpacket size */
 332 static void set_bulk_out_req_length(struct fsg_common *common,
 333                                     struct fsg_buffhd *bh, unsigned int length)
 334 {
 335         unsigned int    rem;
 336
 337         bh->bulk_out_intended_length = length;
 338         rem = length % common->bulk_out_maxpacket;
 339         if (rem > 0)
 340                 length += common->bulk_out_maxpacket - rem;
 341         bh->outreq->length = length;
 342 }
 343
 344
 345 /*-------------------------------------------------------------------------*/
 346
 347 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
 348 {
 349         const char      *name;
 350
 351         if (ep == fsg->bulk_in)
 352                 name = "bulk-in";
 353         else if (ep == fsg->bulk_out)
 354                 name = "bulk-out";
 355         else
 356                 name = ep->name;
 357         DBG(fsg, "%s set halt\n", name);
 358         return usb_ep_set_halt(ep);
 359 }
 360
 361
 362 /*-------------------------------------------------------------------------*/
 363
 364 /* These routines may be called in process context or in_irq */
 365
 366 static void __raise_exception(struct fsg_common *common, enum fsg_state new_state,
 367                               void *arg)
 368 {
 369         unsigned long           flags;
 370
 371         /*
 372          * Do nothing if a higher-priority exception is already in progress.
 373          * If a lower-or-equal priority exception is in progress, preempt it
 374          * and notify the main thread by sending it a signal.
 375          */
 376         spin_lock_irqsave(&common->lock, flags);
 377         if (common->state <= new_state) {
 378                 common->exception_req_tag = common->ep0_req_tag;
 379                 common->state = new_state;
 380                 common->exception_arg = arg;
 381                 if (common->thread_task)
 382                         send_sig_info(SIGUSR1, SEND_SIG_PRIV,
 383                                       common->thread_task);
 384         }
 385         spin_unlock_irqrestore(&common->lock, flags);
 386 }
 387
 388 static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
 389 {
 390         __raise_exception(common, new_state, NULL);
 391 }
 392
 393 /*-------------------------------------------------------------------------*/
 394
 395 static int ep0_queue(struct fsg_common *common)
 396 {
 397         int     rc;
 398
 399         rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
 400         common->ep0->driver_data = common;
 401         if (rc != 0 && rc != -ESHUTDOWN) {
 402                 /* We can't do much more than wait for a reset */
 403                 WARNING(common, "error in submission: %s --> %d\n",
 404                         common->ep0->name, rc);
 405         }
 406         return rc;
 407 }
 408
 409
 410 /*-------------------------------------------------------------------------*/
 411
 412 /* Completion handlers. These always run in_irq. */
 413
 414 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
 415 {
 416         struct fsg_common       *common = ep->driver_data;
 417         struct fsg_buffhd       *bh = req->context;
 418
 419         if (req->status || req->actual != req->length)
 420                 DBG(common, "%s --> %d, %u/%u\n", __func__,
 421                     req->status, req->actual, req->length);
 422         if (req->status == -ECONNRESET)         /* Request was cancelled */
 423                 usb_ep_fifo_flush(ep);
 424
 425         /* Synchronize with the smp_load_acquire() in sleep_thread() */
 426         smp_store_release(&bh->state, BUF_STATE_EMPTY);
 427         wake_up(&common->io_wait);
 428 }
 429
 430 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
 431 {
 432         struct fsg_common       *common = ep->driver_data;
 433         struct fsg_buffhd       *bh = req->context;
 434
 435         dump_msg(common, "bulk-out", req->buf, req->actual);
 436         if (req->status || req->actual != bh->bulk_out_intended_length)
 437                 DBG(common, "%s --> %d, %u/%u\n", __func__,
 438                     req->status, req->actual, bh->bulk_out_intended_length);
 439         if (req->status == -ECONNRESET)         /* Request was cancelled */
 440                 usb_ep_fifo_flush(ep);
 441
 442         /* Synchronize with the smp_load_acquire() in sleep_thread() */
 443         smp_store_release(&bh->state, BUF_STATE_FULL);
 444         wake_up(&common->io_wait);
 445 }
 446
 447 static int _fsg_common_get_max_lun(struct fsg_common *common)
 448 {
 449         int i = ARRAY_SIZE(common->luns) - 1;
 450
 451         while (i >= 0 && !common->luns[i])
 452                 --i;
 453
 454         return i;
 455 }
 456
 457 static int fsg_setup(struct usb_function *f,
 458                      const struct usb_ctrlrequest *ctrl)
 459 {
 460         struct fsg_dev          *fsg = fsg_from_func(f);
 461         struct usb_request      *req = fsg->common->ep0req;
 462         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 463         u16                     w_value = le16_to_cpu(ctrl->wValue);
 464         u16                     w_length = le16_to_cpu(ctrl->wLength);
 465
 466         if (!fsg_is_set(fsg->common))
 467                 return -EOPNOTSUPP;
 468
 469         ++fsg->common->ep0_req_tag;     /* Record arrival of a new request */
 470         req->context = NULL;
 471         req->length = 0;
 472         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
 473
 474         switch (ctrl->bRequest) {
 475
 476         case US_BULK_RESET_REQUEST:
 477                 if (ctrl->bRequestType !=
 478                     (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 479                         break;
 480                 if (w_index != fsg->interface_number || w_value != 0 ||
 481                                 w_length != 0)
 482                         return -EDOM;
 483
 484                 /*
 485                  * Raise an exception to stop the current operation
 486                  * and reinitialize our state.
 487                  */
 488                 DBG(fsg, "bulk reset request\n");
 489                 raise_exception(fsg->common, FSG_STATE_PROTOCOL_RESET);
 490                 return USB_GADGET_DELAYED_STATUS;
 491
 492         case US_BULK_GET_MAX_LUN:
 493                 if (ctrl->bRequestType !=
 494                     (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 495                         break;
 496                 if (w_index != fsg->interface_number || w_value != 0 ||
 497                                 w_length != 1)
 498                         return -EDOM;
 499                 VDBG(fsg, "get max LUN\n");
 500                 *(u8 *)req->buf = _fsg_common_get_max_lun(fsg->common);
 501
 502                 /* Respond with data/status */
 503                 req->length = min((u16)1, w_length);
 504                 return ep0_queue(fsg->common);
 505         }
 506
 507         VDBG(fsg,
 508              "unknown class-specific control req %02x.%02x v%04x i%04x l%u\n",
 509              ctrl->bRequestType, ctrl->bRequest,
 510              le16_to_cpu(ctrl->wValue), w_index, w_length);
 511         return -EOPNOTSUPP;
 512 }
 513
 514
 515 /*-------------------------------------------------------------------------*/
 516
 517 /* All the following routines run in process context */
 518
 519 /* Use this for bulk or interrupt transfers, not ep0 */
 520 static int start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
 521                            struct usb_request *req)
 522 {
 523         int     rc;
 524
 525         if (ep == fsg->bulk_in)
 526                 dump_msg(fsg, "bulk-in", req->buf, req->length);
 527
 528         rc = usb_ep_queue(ep, req, GFP_KERNEL);
 529         if (rc) {
 530
 531                 /* We can't do much more than wait for a reset */
 532                 req->status = rc;
 533
 534                 /*
 535                  * Note: currently the net2280 driver fails zero-length
 536                  * submissions if DMA is enabled.
 537                  */
 538                 if (rc != -ESHUTDOWN &&
 539                                 !(rc == -EOPNOTSUPP && req->length == 0))
 540                         WARNING(fsg, "error in submission: %s --> %d\n",
 541                                         ep->name, rc);
 542         }
 543         return rc;
 544 }
 545
 546 static bool start_in_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
 547 {
 548         int rc;
 549
 550         if (!fsg_is_set(common))
 551                 return false;
 552         bh->state = BUF_STATE_SENDING;
 553         rc = start_transfer(common->fsg, common->fsg->bulk_in, bh->inreq);
 554         if (rc) {
 555                 bh->state = BUF_STATE_EMPTY;
 556                 if (rc == -ESHUTDOWN) {
 557                         common->running = 0;
 558                         return false;
 559                 }
 560         }
 561         return true;
 562 }
 563
 564 static bool start_out_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
 565 {
 566         int rc;
 567
 568         if (!fsg_is_set(common))
 569                 return false;
 570         bh->state = BUF_STATE_RECEIVING;
 571         rc = start_transfer(common->fsg, common->fsg->bulk_out, bh->outreq);
 572         if (rc) {
 573                 bh->state = BUF_STATE_FULL;
 574                 if (rc == -ESHUTDOWN) {
 575                         common->running = 0;
 576                         return false;
 577                 }
 578         }
 579         return true;
 580 }
 581
 582 static int sleep_thread(struct fsg_common *common, bool can_freeze,
 583                 struct fsg_buffhd *bh)
 584 {
 585         int     rc;
 586
 587         /* Wait until a signal arrives or bh is no longer busy */
 588         if (can_freeze)
 589                 /*
 590                  * synchronize with the smp_store_release(&bh->state) in
 591                  * bulk_in_complete() or bulk_out_complete()
 592                  */
 593                 rc = wait_event_freezable(common->io_wait,
 594                                 bh && smp_load_acquire(&bh->state) >=
 595                                         BUF_STATE_EMPTY);
 596         else
 597                 rc = wait_event_interruptible(common->io_wait,
 598                                 bh && smp_load_acquire(&bh->state) >=
 599                                         BUF_STATE_EMPTY);
 600         return rc ? -EINTR : 0;
 601 }
 602
 603
 604 /*-------------------------------------------------------------------------*/
 605
 606 static int do_read(struct fsg_common *common)
 607 {
 608         struct fsg_lun          *curlun = common->curlun;
 609         u64                     lba;
 610         struct fsg_buffhd       *bh;
 611         int                     rc;
 612         u32                     amount_left;
 613         loff_t                  file_offset, file_offset_tmp;
 614         unsigned int            amount;
 615         ssize_t                 nread;
 616
 617         /*
 618          * Get the starting Logical Block Address and check that it's
 619          * not too big.
 620          */
 621         if (common->cmnd[0] == READ_6)
 622                 lba = get_unaligned_be24(&common->cmnd[1]);
 623         else {
 624                 if (common->cmnd[0] == READ_16)
 625                         lba = get_unaligned_be64(&common->cmnd[2]);
 626                 else            /* READ_10 or READ_12 */
 627                         lba = get_unaligned_be32(&common->cmnd[2]);
 628
 629                 /*
 630                  * We allow DPO (Disable Page Out = don't save data in the
 631                  * cache) and FUA (Force Unit Access = don't read from the
 632                  * cache), but we don't implement them.
 633                  */
 634                 if ((common->cmnd[1] & ~0x18) != 0) {
 635                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
 636                         return -EINVAL;
 637                 }
 638         }
 639         if (lba >= curlun->num_sectors) {
 640                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 641                 return -EINVAL;
 642         }
 643         file_offset = ((loff_t) lba) << curlun->blkbits;
 644
 645         /* Carry out the file reads */
 646         amount_left = common->data_size_from_cmnd;
 647         if (unlikely(amount_left == 0))
 648                 return -EIO;            /* No default reply */
 649
 650         for (;;) {
 651                 /*
 652                  * Figure out how much we need to read:
 653                  * Try to read the remaining amount.
 654                  * But don't read more than the buffer size.
 655                  * And don't try to read past the end of the file.
 656                  */
 657                 amount = min(amount_left, FSG_BUFLEN);
 658                 amount = min((loff_t)amount,
 659                              curlun->file_length - file_offset);
 660
 661                 /* Wait for the next buffer to become available */
 662                 bh = common->next_buffhd_to_fill;
 663                 rc = sleep_thread(common, false, bh);
 664                 if (rc)
 665                         return rc;
 666
 667                 /*
 668                  * If we were asked to read past the end of file,
 669                  * end with an empty buffer.
 670                  */
 671                 if (amount == 0) {
 672                         curlun->sense_data =
 673                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 674                         curlun->sense_data_info =
 675                                         file_offset >> curlun->blkbits;
 676                         curlun->info_valid = 1;
 677                         bh->inreq->length = 0;
 678                         bh->state = BUF_STATE_FULL;
 679                         break;
 680                 }
 681
 682                 /* Perform the read */
 683                 file_offset_tmp = file_offset;
 684                 nread = kernel_read(curlun->filp, bh->buf, amount,
 685                                 &file_offset_tmp);
 686                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
 687                       (unsigned long long)file_offset, (int)nread);
 688                 if (signal_pending(current))
 689                         return -EINTR;
 690
 691                 if (nread < 0) {
 692                         LDBG(curlun, "error in file read: %d\n", (int)nread);
 693                         nread = 0;
 694                 } else if (nread < amount) {
 695                         LDBG(curlun, "partial file read: %d/%u\n",
 696                              (int)nread, amount);
 697                         nread = round_down(nread, curlun->blksize);
 698                 }
 699                 file_offset  += nread;
 700                 amount_left  -= nread;
 701                 common->residue -= nread;
 702
 703                 /*
 704                  * Except at the end of the transfer, nread will be
 705                  * equal to the buffer size, which is divisible by the
 706                  * bulk-in maxpacket size.
 707                  */
 708                 bh->inreq->length = nread;
 709                 bh->state = BUF_STATE_FULL;
 710
 711                 /* If an error occurred, report it and its position */
 712                 if (nread < amount) {
 713                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
 714                         curlun->sense_data_info =
 715                                         file_offset >> curlun->blkbits;
 716                         curlun->info_valid = 1;
 717                         break;
 718                 }
 719
 720                 if (amount_left == 0)
 721                         break;          /* No more left to read */
 722
 723                 /* Send this buffer and go read some more */
 724                 bh->inreq->zero = 0;
 725                 if (!start_in_transfer(common, bh))
 726                         /* Don't know what to do if common->fsg is NULL */
 727                         return -EIO;
 728                 common->next_buffhd_to_fill = bh->next;
 729         }
 730
 731         return -EIO;            /* No default reply */
 732 }
 733
 734
 735 /*-------------------------------------------------------------------------*/
 736
 737 static int do_write(struct fsg_common *common)
 738 {
 739         struct fsg_lun          *curlun = common->curlun;
 740         u64                     lba;
 741         struct fsg_buffhd       *bh;
 742         int                     get_some_more;
 743         u32                     amount_left_to_req, amount_left_to_write;
 744         loff_t                  usb_offset, file_offset, file_offset_tmp;
 745         unsigned int            amount;
 746         ssize_t                 nwritten;
 747         int                     rc;
 748
 749         if (curlun->ro) {
 750                 curlun->sense_data = SS_WRITE_PROTECTED;
 751                 return -EINVAL;
 752         }
 753         spin_lock(&curlun->filp->f_lock);
 754         curlun->filp->f_flags &= ~O_SYNC;       /* Default is not to wait */
 755         spin_unlock(&curlun->filp->f_lock);
 756
 757         /*
 758          * Get the starting Logical Block Address and check that it's
 759          * not too big
 760          */
 761         if (common->cmnd[0] == WRITE_6)
 762                 lba = get_unaligned_be24(&common->cmnd[1]);
 763         else {
 764                 if (common->cmnd[0] == WRITE_16)
 765                         lba = get_unaligned_be64(&common->cmnd[2]);
 766                 else            /* WRITE_10 or WRITE_12 */
 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 __maybe_unused    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         u32             max_lba;
1143
1144         /* Check the PMI and LBA fields */
1145         if (pmi > 1 || (pmi == 0 && lba != 0)) {
1146                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1147                 return -EINVAL;
1148         }
1149
1150         if (curlun->num_sectors < 0x100000000ULL)
1151                 max_lba = curlun->num_sectors - 1;
1152         else
1153                 max_lba = 0xffffffff;
1154         put_unaligned_be32(max_lba, &buf[0]);           /* Max logical block */
1155         put_unaligned_be32(curlun->blksize, &buf[4]);   /* Block length */
1156         return 8;
1157 }
1158
1159 static int do_read_capacity_16(struct fsg_common *common, struct fsg_buffhd *bh)
1160 {
1161         struct fsg_lun  *curlun = common->curlun;
1162         u64             lba = get_unaligned_be64(&common->cmnd[2]);
1163         int             pmi = common->cmnd[14];
1164         u8              *buf = (u8 *)bh->buf;
1165
1166         /* Check the PMI and LBA fields */
1167         if (pmi > 1 || (pmi == 0 && lba != 0)) {
1168                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1169                 return -EINVAL;
1170         }
1171
1172         put_unaligned_be64(curlun->num_sectors - 1, &buf[0]);
1173                                                         /* Max logical block */
1174         put_unaligned_be32(curlun->blksize, &buf[8]);   /* Block length */
1175
1176         /* It is safe to keep other fields zeroed */
1177         memset(&buf[12], 0, 32 - 12);
1178         return 32;
1179 }
1180
1181 static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
1182 {
1183         struct fsg_lun  *curlun = common->curlun;
1184         int             msf = common->cmnd[1] & 0x02;
1185         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1186         u8              *buf = (u8 *)bh->buf;
1187
1188         if (common->cmnd[1] & ~0x02) {          /* Mask away MSF */
1189                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1190                 return -EINVAL;
1191         }
1192         if (lba >= curlun->num_sectors) {
1193                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1194                 return -EINVAL;
1195         }
1196
1197         memset(buf, 0, 8);
1198         buf[0] = 0x01;          /* 2048 bytes of user data, rest is EC */
1199         store_cdrom_address(&buf[4], msf, lba);
1200         return 8;
1201 }
1202
1203 static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
1204 {
1205         struct fsg_lun  *curlun = common->curlun;
1206         int             msf = common->cmnd[1] & 0x02;
1207         int             start_track = common->cmnd[6];
1208         u8              *buf = (u8 *)bh->buf;
1209         u8              format;
1210         int             i, len;
1211
1212         format = common->cmnd[2] & 0xf;
1213
1214         if ((common->cmnd[1] & ~0x02) != 0 ||   /* Mask away MSF */
1215                         (start_track > 1 && format != 0x1)) {
1216                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1217                 return -EINVAL;
1218         }
1219
1220         /*
1221          * Check if CDB is old style SFF-8020i
1222          * i.e. format is in 2 MSBs of byte 9
1223          * Mac OS-X host sends us this.
1224          */
1225         if (format == 0)
1226                 format = (common->cmnd[9] >> 6) & 0x3;
1227
1228         switch (format) {
1229         case 0: /* Formatted TOC */
1230         case 1: /* Multi-session info */
1231                 len = 4 + 2*8;          /* 4 byte header + 2 descriptors */
1232                 memset(buf, 0, len);
1233                 buf[1] = len - 2;       /* TOC Length excludes length field */
1234                 buf[2] = 1;             /* First track number */
1235                 buf[3] = 1;             /* Last track number */
1236                 buf[5] = 0x16;          /* Data track, copying allowed */
1237                 buf[6] = 0x01;          /* Only track is number 1 */
1238                 store_cdrom_address(&buf[8], msf, 0);
1239
1240                 buf[13] = 0x16;         /* Lead-out track is data */
1241                 buf[14] = 0xAA;         /* Lead-out track number */
1242                 store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1243                 return len;
1244
1245         case 2:
1246                 /* Raw TOC */
1247                 len = 4 + 3*11;         /* 4 byte header + 3 descriptors */
1248                 memset(buf, 0, len);    /* Header + A0, A1 & A2 descriptors */
1249                 buf[1] = len - 2;       /* TOC Length excludes length field */
1250                 buf[2] = 1;             /* First complete session */
1251                 buf[3] = 1;             /* Last complete session */
1252
1253                 buf += 4;
1254                 /* fill in A0, A1 and A2 points */
1255                 for (i = 0; i < 3; i++) {
1256                         buf[0] = 1;     /* Session number */
1257                         buf[1] = 0x16;  /* Data track, copying allowed */
1258                         /* 2 - Track number 0 ->  TOC */
1259                         buf[3] = 0xA0 + i; /* A0, A1, A2 point */
1260                         /* 4, 5, 6 - Min, sec, frame is zero */
1261                         buf[8] = 1;     /* Pmin: last track number */
1262                         buf += 11;      /* go to next track descriptor */
1263                 }
1264                 buf -= 11;              /* go back to A2 descriptor */
1265
1266                 /* For A2, 7, 8, 9, 10 - zero, Pmin, Psec, Pframe of Lead out */
1267                 store_cdrom_address(&buf[7], msf, curlun->num_sectors);
1268                 return len;
1269
1270         default:
1271                 /* PMA, ATIP, CD-TEXT not supported/required */
1272                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1273                 return -EINVAL;
1274         }
1275 }
1276
1277 static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1278 {
1279         struct fsg_lun  *curlun = common->curlun;
1280         int             mscmnd = common->cmnd[0];
1281         u8              *buf = (u8 *) bh->buf;
1282         u8              *buf0 = buf;
1283         int             pc, page_code;
1284         int             changeable_values, all_pages;
1285         int             valid_page = 0;
1286         int             len, limit;
1287
1288         if ((common->cmnd[1] & ~0x08) != 0) {   /* Mask away DBD */
1289                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1290                 return -EINVAL;
1291         }
1292         pc = common->cmnd[2] >> 6;
1293         page_code = common->cmnd[2] & 0x3f;
1294         if (pc == 3) {
1295                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1296                 return -EINVAL;
1297         }
1298         changeable_values = (pc == 1);
1299         all_pages = (page_code == 0x3f);
1300
1301         /*
1302          * Write the mode parameter header.  Fixed values are: default
1303          * medium type, no cache control (DPOFUA), and no block descriptors.
1304          * The only variable value is the WriteProtect bit.  We will fill in
1305          * the mode data length later.
1306          */
1307         memset(buf, 0, 8);
1308         if (mscmnd == MODE_SENSE) {
1309                 buf[2] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1310                 buf += 4;
1311                 limit = 255;
1312         } else {                        /* MODE_SENSE_10 */
1313                 buf[3] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1314                 buf += 8;
1315                 limit = 65535;          /* Should really be FSG_BUFLEN */
1316         }
1317
1318         /* No block descriptors */
1319
1320         /*
1321          * The mode pages, in numerical order.  The only page we support
1322          * is the Caching page.
1323          */
1324         if (page_code == 0x08 || all_pages) {
1325                 valid_page = 1;
1326                 buf[0] = 0x08;          /* Page code */
1327                 buf[1] = 10;            /* Page length */
1328                 memset(buf+2, 0, 10);   /* None of the fields are changeable */
1329
1330                 if (!changeable_values) {
1331                         buf[2] = 0x04;  /* Write cache enable, */
1332                                         /* Read cache not disabled */
1333                                         /* No cache retention priorities */
1334                         put_unaligned_be16(0xffff, &buf[4]);
1335                                         /* Don't disable prefetch */
1336                                         /* Minimum prefetch = 0 */
1337                         put_unaligned_be16(0xffff, &buf[8]);
1338                                         /* Maximum prefetch */
1339                         put_unaligned_be16(0xffff, &buf[10]);
1340                                         /* Maximum prefetch ceiling */
1341                 }
1342                 buf += 12;
1343         }
1344
1345         /*
1346          * Check that a valid page was requested and the mode data length
1347          * isn't too long.
1348          */
1349         len = buf - buf0;
1350         if (!valid_page || len > limit) {
1351                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1352                 return -EINVAL;
1353         }
1354
1355         /*  Store the mode data length */
1356         if (mscmnd == MODE_SENSE)
1357                 buf0[0] = len - 1;
1358         else
1359                 put_unaligned_be16(len - 2, buf0);
1360         return len;
1361 }
1362
1363 static int do_start_stop(struct fsg_common *common)
1364 {
1365         struct fsg_lun  *curlun = common->curlun;
1366         int             loej, start;
1367
1368         if (!curlun) {
1369                 return -EINVAL;
1370         } else if (!curlun->removable) {
1371                 curlun->sense_data = SS_INVALID_COMMAND;
1372                 return -EINVAL;
1373         } else if ((common->cmnd[1] & ~0x01) != 0 || /* Mask away Immed */
1374                    (common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */
1375                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1376                 return -EINVAL;
1377         }
1378
1379         loej  = common->cmnd[4] & 0x02;
1380         start = common->cmnd[4] & 0x01;
1381
1382         /*
1383          * Our emulation doesn't support mounting; the medium is
1384          * available for use as soon as it is loaded.
1385          */
1386         if (start) {
1387                 if (!fsg_lun_is_open(curlun)) {
1388                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1389                         return -EINVAL;
1390                 }
1391                 return 0;
1392         }
1393
1394         /* Are we allowed to unload the media? */
1395         if (curlun->prevent_medium_removal) {
1396                 LDBG(curlun, "unload attempt prevented\n");
1397                 curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
1398                 return -EINVAL;
1399         }
1400
1401         if (!loej)
1402                 return 0;
1403
1404         up_read(&common->filesem);
1405         down_write(&common->filesem);
1406         fsg_lun_close(curlun);
1407         up_write(&common->filesem);
1408         down_read(&common->filesem);
1409
1410         return 0;
1411 }
1412
1413 static int do_prevent_allow(struct fsg_common *common)
1414 {
1415         struct fsg_lun  *curlun = common->curlun;
1416         int             prevent;
1417
1418         if (!common->curlun) {
1419                 return -EINVAL;
1420         } else if (!common->curlun->removable) {
1421                 common->curlun->sense_data = SS_INVALID_COMMAND;
1422                 return -EINVAL;
1423         }
1424
1425         prevent = common->cmnd[4] & 0x01;
1426         if ((common->cmnd[4] & ~0x01) != 0) {   /* Mask away Prevent */
1427                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1428                 return -EINVAL;
1429         }
1430
1431         if (curlun->prevent_medium_removal && !prevent)
1432                 fsg_lun_fsync_sub(curlun);
1433         curlun->prevent_medium_removal = prevent;
1434         return 0;
1435 }
1436
1437 static int do_read_format_capacities(struct fsg_common *common,
1438                         struct fsg_buffhd *bh)
1439 {
1440         struct fsg_lun  *curlun = common->curlun;
1441         u8              *buf = (u8 *) bh->buf;
1442
1443         buf[0] = buf[1] = buf[2] = 0;
1444         buf[3] = 8;     /* Only the Current/Maximum Capacity Descriptor */
1445         buf += 4;
1446
1447         put_unaligned_be32(curlun->num_sectors, &buf[0]);
1448                                                 /* Number of blocks */
1449         put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
1450         buf[4] = 0x02;                          /* Current capacity */
1451         return 12;
1452 }
1453
1454 static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
1455 {
1456         struct fsg_lun  *curlun = common->curlun;
1457
1458         /* We don't support MODE SELECT */
1459         if (curlun)
1460                 curlun->sense_data = SS_INVALID_COMMAND;
1461         return -EINVAL;
1462 }
1463
1464
1465 /*-------------------------------------------------------------------------*/
1466
1467 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1468 {
1469         int     rc;
1470
1471         rc = fsg_set_halt(fsg, fsg->bulk_in);
1472         if (rc == -EAGAIN)
1473                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1474         while (rc != 0) {
1475                 if (rc != -EAGAIN) {
1476                         WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1477                         rc = 0;
1478                         break;
1479                 }
1480
1481                 /* Wait for a short time and then try again */
1482                 if (msleep_interruptible(100) != 0)
1483                         return -EINTR;
1484                 rc = usb_ep_set_halt(fsg->bulk_in);
1485         }
1486         return rc;
1487 }
1488
1489 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1490 {
1491         int     rc;
1492
1493         DBG(fsg, "bulk-in set wedge\n");
1494         rc = usb_ep_set_wedge(fsg->bulk_in);
1495         if (rc == -EAGAIN)
1496                 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1497         while (rc != 0) {
1498                 if (rc != -EAGAIN) {
1499                         WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1500                         rc = 0;
1501                         break;
1502                 }
1503
1504                 /* Wait for a short time and then try again */
1505                 if (msleep_interruptible(100) != 0)
1506                         return -EINTR;
1507                 rc = usb_ep_set_wedge(fsg->bulk_in);
1508         }
1509         return rc;
1510 }
1511
1512 static int throw_away_data(struct fsg_common *common)
1513 {
1514         struct fsg_buffhd       *bh, *bh2;
1515         u32                     amount;
1516         int                     rc;
1517
1518         for (bh = common->next_buffhd_to_drain;
1519              bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
1520              bh = common->next_buffhd_to_drain) {
1521
1522                 /* Try to submit another request if we need one */
1523                 bh2 = common->next_buffhd_to_fill;
1524                 if (bh2->state == BUF_STATE_EMPTY &&
1525                                 common->usb_amount_left > 0) {
1526                         amount = min(common->usb_amount_left, FSG_BUFLEN);
1527
1528                         /*
1529                          * Except at the end of the transfer, amount will be
1530                          * equal to the buffer size, which is divisible by
1531                          * the bulk-out maxpacket size.
1532                          */
1533                         set_bulk_out_req_length(common, bh2, amount);
1534                         if (!start_out_transfer(common, bh2))
1535                                 /* Dunno what to do if common->fsg is NULL */
1536                                 return -EIO;
1537                         common->next_buffhd_to_fill = bh2->next;
1538                         common->usb_amount_left -= amount;
1539                         continue;
1540                 }
1541
1542                 /* Wait for the data to be received */
1543                 rc = sleep_thread(common, false, bh);
1544                 if (rc)
1545                         return rc;
1546
1547                 /* Throw away the data in a filled buffer */
1548                 bh->state = BUF_STATE_EMPTY;
1549                 common->next_buffhd_to_drain = bh->next;
1550
1551                 /* A short packet or an error ends everything */
1552                 if (bh->outreq->actual < bh->bulk_out_intended_length ||
1553                                 bh->outreq->status != 0) {
1554                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1555                         return -EINTR;
1556                 }
1557         }
1558         return 0;
1559 }
1560
1561 static int finish_reply(struct fsg_common *common)
1562 {
1563         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
1564         int                     rc = 0;
1565
1566         switch (common->data_dir) {
1567         case DATA_DIR_NONE:
1568                 break;                  /* Nothing to send */
1569
1570         /*
1571          * If we don't know whether the host wants to read or write,
1572          * this must be CB or CBI with an unknown command.  We mustn't
1573          * try to send or receive any data.  So stall both bulk pipes
1574          * if we can and wait for a reset.
1575          */
1576         case DATA_DIR_UNKNOWN:
1577                 if (!common->can_stall) {
1578                         /* Nothing */
1579                 } else if (fsg_is_set(common)) {
1580                         fsg_set_halt(common->fsg, common->fsg->bulk_out);
1581                         rc = halt_bulk_in_endpoint(common->fsg);
1582                 } else {
1583                         /* Don't know what to do if common->fsg is NULL */
1584                         rc = -EIO;
1585                 }
1586                 break;
1587
1588         /* All but the last buffer of data must have already been sent */
1589         case DATA_DIR_TO_HOST:
1590                 if (common->data_size == 0) {
1591                         /* Nothing to send */
1592
1593                 /* Don't know what to do if common->fsg is NULL */
1594                 } else if (!fsg_is_set(common)) {
1595                         rc = -EIO;
1596
1597                 /* If there's no residue, simply send the last buffer */
1598                 } else if (common->residue == 0) {
1599                         bh->inreq->zero = 0;
1600                         if (!start_in_transfer(common, bh))
1601                                 return -EIO;
1602                         common->next_buffhd_to_fill = bh->next;
1603
1604                 /*
1605                  * For Bulk-only, mark the end of the data with a short
1606                  * packet.  If we are allowed to stall, halt the bulk-in
1607                  * endpoint.  (Note: This violates the Bulk-Only Transport
1608                  * specification, which requires us to pad the data if we
1609                  * don't halt the endpoint.  Presumably nobody will mind.)
1610                  */
1611                 } else {
1612                         bh->inreq->zero = 1;
1613                         if (!start_in_transfer(common, bh))
1614                                 rc = -EIO;
1615                         common->next_buffhd_to_fill = bh->next;
1616                         if (common->can_stall)
1617                                 rc = halt_bulk_in_endpoint(common->fsg);
1618                 }
1619                 break;
1620
1621         /*
1622          * We have processed all we want from the data the host has sent.
1623          * There may still be outstanding bulk-out requests.
1624          */
1625         case DATA_DIR_FROM_HOST:
1626                 if (common->residue == 0) {
1627                         /* Nothing to receive */
1628
1629                 /* Did the host stop sending unexpectedly early? */
1630                 } else if (common->short_packet_received) {
1631                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1632                         rc = -EINTR;
1633
1634                 /*
1635                  * We haven't processed all the incoming data.  Even though
1636                  * we may be allowed to stall, doing so would cause a race.
1637                  * The controller may already have ACK'ed all the remaining
1638                  * bulk-out packets, in which case the host wouldn't see a
1639                  * STALL.  Not realizing the endpoint was halted, it wouldn't
1640                  * clear the halt -- leading to problems later on.
1641                  */
1642 #if 0
1643                 } else if (common->can_stall) {
1644                         if (fsg_is_set(common))
1645                                 fsg_set_halt(common->fsg,
1646                                              common->fsg->bulk_out);
1647                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1648                         rc = -EINTR;
1649 #endif
1650
1651                 /*
1652                  * We can't stall.  Read in the excess data and throw it
1653                  * all away.
1654                  */
1655                 } else {
1656                         rc = throw_away_data(common);
1657                 }
1658                 break;
1659         }
1660         return rc;
1661 }
1662
1663 static void send_status(struct fsg_common *common)
1664 {
1665         struct fsg_lun          *curlun = common->curlun;
1666         struct fsg_buffhd       *bh;
1667         struct bulk_cs_wrap     *csw;
1668         int                     rc;
1669         u8                      status = US_BULK_STAT_OK;
1670         u32                     sd, sdinfo = 0;
1671
1672         /* Wait for the next buffer to become available */
1673         bh = common->next_buffhd_to_fill;
1674         rc = sleep_thread(common, false, bh);
1675         if (rc)
1676                 return;
1677
1678         if (curlun) {
1679                 sd = curlun->sense_data;
1680                 sdinfo = curlun->sense_data_info;
1681         } else if (common->bad_lun_okay)
1682                 sd = SS_NO_SENSE;
1683         else
1684                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1685
1686         if (common->phase_error) {
1687                 DBG(common, "sending phase-error status\n");
1688                 status = US_BULK_STAT_PHASE;
1689                 sd = SS_INVALID_COMMAND;
1690         } else if (sd != SS_NO_SENSE) {
1691                 DBG(common, "sending command-failure status\n");
1692                 status = US_BULK_STAT_FAIL;
1693                 VDBG(common, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
1694                                 "  info x%x\n",
1695                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
1696         }
1697
1698         /* Store and send the Bulk-only CSW */
1699         csw = (void *)bh->buf;
1700
1701         csw->Signature = cpu_to_le32(US_BULK_CS_SIGN);
1702         csw->Tag = common->tag;
1703         csw->Residue = cpu_to_le32(common->residue);
1704         csw->Status = status;
1705
1706         bh->inreq->length = US_BULK_CS_WRAP_LEN;
1707         bh->inreq->zero = 0;
1708         if (!start_in_transfer(common, bh))
1709                 /* Don't know what to do if common->fsg is NULL */
1710                 return;
1711
1712         common->next_buffhd_to_fill = bh->next;
1713         return;
1714 }
1715
1716
1717 /*-------------------------------------------------------------------------*/
1718
1719 /*
1720  * Check whether the command is properly formed and whether its data size
1721  * and direction agree with the values we already have.
1722  */
1723 static int check_command(struct fsg_common *common, int cmnd_size,
1724                          enum data_direction data_dir, unsigned int mask,
1725                          int needs_medium, const char *name)
1726 {
1727         int                     i;
1728         unsigned int            lun = common->cmnd[1] >> 5;
1729         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
1730         char                    hdlen[20];
1731         struct fsg_lun          *curlun;
1732
1733         hdlen[0] = 0;
1734         if (common->data_dir != DATA_DIR_UNKNOWN)
1735                 sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
1736                         common->data_size);
1737         VDBG(common, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
1738              name, cmnd_size, dirletter[(int) data_dir],
1739              common->data_size_from_cmnd, common->cmnd_size, hdlen);
1740
1741         /*
1742          * We can't reply at all until we know the correct data direction
1743          * and size.
1744          */
1745         if (common->data_size_from_cmnd == 0)
1746                 data_dir = DATA_DIR_NONE;
1747         if (common->data_size < common->data_size_from_cmnd) {
1748                 /*
1749                  * Host data size < Device data size is a phase error.
1750                  * Carry out the command, but only transfer as much as
1751                  * we are allowed.
1752                  */
1753                 common->data_size_from_cmnd = common->data_size;
1754                 common->phase_error = 1;
1755         }
1756         common->residue = common->data_size;
1757         common->usb_amount_left = common->data_size;
1758
1759         /* Conflicting data directions is a phase error */
1760         if (common->data_dir != data_dir && common->data_size_from_cmnd > 0) {
1761                 common->phase_error = 1;
1762                 return -EINVAL;
1763         }
1764
1765         /* Verify the length of the command itself */
1766         if (cmnd_size != common->cmnd_size) {
1767
1768                 /*
1769                  * Special case workaround: There are plenty of buggy SCSI
1770                  * implementations. Many have issues with cbw->Length
1771                  * field passing a wrong command size. For those cases we
1772                  * always try to work around the problem by using the length
1773                  * sent by the host side provided it is at least as large
1774                  * as the correct command length.
1775                  * Examples of such cases would be MS-Windows, which issues
1776                  * REQUEST SENSE with cbw->Length == 12 where it should
1777                  * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
1778                  * REQUEST SENSE with cbw->Length == 10 where it should
1779                  * be 6 as well.
1780                  */
1781                 if (cmnd_size <= common->cmnd_size) {
1782                         DBG(common, "%s is buggy! Expected length %d "
1783                             "but we got %d\n", name,
1784                             cmnd_size, common->cmnd_size);
1785                         cmnd_size = common->cmnd_size;
1786                 } else {
1787                         common->phase_error = 1;
1788                         return -EINVAL;
1789                 }
1790         }
1791
1792         /* Check that the LUN values are consistent */
1793         if (common->lun != lun)
1794                 DBG(common, "using LUN %u from CBW, not LUN %u from CDB\n",
1795                     common->lun, lun);
1796
1797         /* Check the LUN */
1798         curlun = common->curlun;
1799         if (curlun) {
1800                 if (common->cmnd[0] != REQUEST_SENSE) {
1801                         curlun->sense_data = SS_NO_SENSE;
1802                         curlun->sense_data_info = 0;
1803                         curlun->info_valid = 0;
1804                 }
1805         } else {
1806                 common->bad_lun_okay = 0;
1807
1808                 /*
1809                  * INQUIRY and REQUEST SENSE commands are explicitly allowed
1810                  * to use unsupported LUNs; all others may not.
1811                  */
1812                 if (common->cmnd[0] != INQUIRY &&
1813                     common->cmnd[0] != REQUEST_SENSE) {
1814                         DBG(common, "unsupported LUN %u\n", common->lun);
1815                         return -EINVAL;
1816                 }
1817         }
1818
1819         /*
1820          * If a unit attention condition exists, only INQUIRY and
1821          * REQUEST SENSE commands are allowed; anything else must fail.
1822          */
1823         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
1824             common->cmnd[0] != INQUIRY &&
1825             common->cmnd[0] != REQUEST_SENSE) {
1826                 curlun->sense_data = curlun->unit_attention_data;
1827                 curlun->unit_attention_data = SS_NO_SENSE;
1828                 return -EINVAL;
1829         }
1830
1831         /* Check that only command bytes listed in the mask are non-zero */
1832         common->cmnd[1] &= 0x1f;                        /* Mask away the LUN */
1833         for (i = 1; i < cmnd_size; ++i) {
1834                 if (common->cmnd[i] && !(mask & (1 << i))) {
1835                         if (curlun)
1836                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1837                         return -EINVAL;
1838                 }
1839         }
1840
1841         /* If the medium isn't mounted and the command needs to access
1842          * it, return an error. */
1843         if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
1844                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1845                 return -EINVAL;
1846         }
1847
1848         return 0;
1849 }
1850
1851 /* wrapper of check_command for data size in blocks handling */
1852 static int check_command_size_in_blocks(struct fsg_common *common,
1853                 int cmnd_size, enum data_direction data_dir,
1854                 unsigned int mask, int needs_medium, const char *name)
1855 {
1856         if (common->curlun)
1857                 common->data_size_from_cmnd <<= common->curlun->blkbits;
1858         return check_command(common, cmnd_size, data_dir,
1859                         mask, needs_medium, name);
1860 }
1861
1862 static int do_scsi_command(struct fsg_common *common)
1863 {
1864         struct fsg_buffhd       *bh;
1865         int                     rc;
1866         int                     reply = -EINVAL;
1867         int                     i;
1868         static char             unknown[16];
1869
1870         dump_cdb(common);
1871
1872         /* Wait for the next buffer to become available for data or status */
1873         bh = common->next_buffhd_to_fill;
1874         common->next_buffhd_to_drain = bh;
1875         rc = sleep_thread(common, false, bh);
1876         if (rc)
1877                 return rc;
1878
1879         common->phase_error = 0;
1880         common->short_packet_received = 0;
1881
1882         down_read(&common->filesem);    /* We're using the backing file */
1883         switch (common->cmnd[0]) {
1884
1885         case INQUIRY:
1886                 common->data_size_from_cmnd = common->cmnd[4];
1887                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1888                                       (1<<4), 0,
1889                                       "INQUIRY");
1890                 if (reply == 0)
1891                         reply = do_inquiry(common, bh);
1892                 break;
1893
1894         case MODE_SELECT:
1895                 common->data_size_from_cmnd = common->cmnd[4];
1896                 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
1897                                       (1<<1) | (1<<4), 0,
1898                                       "MODE SELECT(6)");
1899                 if (reply == 0)
1900                         reply = do_mode_select(common, bh);
1901                 break;
1902
1903         case MODE_SELECT_10:
1904                 common->data_size_from_cmnd =
1905                         get_unaligned_be16(&common->cmnd[7]);
1906                 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
1907                                       (1<<1) | (3<<7), 0,
1908                                       "MODE SELECT(10)");
1909                 if (reply == 0)
1910                         reply = do_mode_select(common, bh);
1911                 break;
1912
1913         case MODE_SENSE:
1914                 common->data_size_from_cmnd = common->cmnd[4];
1915                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1916                                       (1<<1) | (1<<2) | (1<<4), 0,
1917                                       "MODE SENSE(6)");
1918                 if (reply == 0)
1919                         reply = do_mode_sense(common, bh);
1920                 break;
1921
1922         case MODE_SENSE_10:
1923                 common->data_size_from_cmnd =
1924                         get_unaligned_be16(&common->cmnd[7]);
1925                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1926                                       (1<<1) | (1<<2) | (3<<7), 0,
1927                                       "MODE SENSE(10)");
1928                 if (reply == 0)
1929                         reply = do_mode_sense(common, bh);
1930                 break;
1931
1932         case ALLOW_MEDIUM_REMOVAL:
1933                 common->data_size_from_cmnd = 0;
1934                 reply = check_command(common, 6, DATA_DIR_NONE,
1935                                       (1<<4), 0,
1936                                       "PREVENT-ALLOW MEDIUM REMOVAL");
1937                 if (reply == 0)
1938                         reply = do_prevent_allow(common);
1939                 break;
1940
1941         case READ_6:
1942                 i = common->cmnd[4];
1943                 common->data_size_from_cmnd = (i == 0) ? 256 : i;
1944                 reply = check_command_size_in_blocks(common, 6,
1945                                       DATA_DIR_TO_HOST,
1946                                       (7<<1) | (1<<4), 1,
1947                                       "READ(6)");
1948                 if (reply == 0)
1949                         reply = do_read(common);
1950                 break;
1951
1952         case READ_10:
1953                 common->data_size_from_cmnd =
1954                                 get_unaligned_be16(&common->cmnd[7]);
1955                 reply = check_command_size_in_blocks(common, 10,
1956                                       DATA_DIR_TO_HOST,
1957                                       (1<<1) | (0xf<<2) | (3<<7), 1,
1958                                       "READ(10)");
1959                 if (reply == 0)
1960                         reply = do_read(common);
1961                 break;
1962
1963         case READ_12:
1964                 common->data_size_from_cmnd =
1965                                 get_unaligned_be32(&common->cmnd[6]);
1966                 reply = check_command_size_in_blocks(common, 12,
1967                                       DATA_DIR_TO_HOST,
1968                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
1969                                       "READ(12)");
1970                 if (reply == 0)
1971                         reply = do_read(common);
1972                 break;
1973
1974         case READ_16:
1975                 common->data_size_from_cmnd =
1976                                 get_unaligned_be32(&common->cmnd[10]);
1977                 reply = check_command_size_in_blocks(common, 16,
1978                                       DATA_DIR_TO_HOST,
1979                                       (1<<1) | (0xff<<2) | (0xf<<10), 1,
1980                                       "READ(16)");
1981                 if (reply == 0)
1982                         reply = do_read(common);
1983                 break;
1984
1985         case READ_CAPACITY:
1986                 common->data_size_from_cmnd = 8;
1987                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1988                                       (0xf<<2) | (1<<8), 1,
1989                                       "READ CAPACITY");
1990                 if (reply == 0)
1991                         reply = do_read_capacity(common, bh);
1992                 break;
1993
1994         case READ_HEADER:
1995                 if (!common->curlun || !common->curlun->cdrom)
1996                         goto unknown_cmnd;
1997                 common->data_size_from_cmnd =
1998                         get_unaligned_be16(&common->cmnd[7]);
1999                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2000                                       (3<<7) | (0x1f<<1), 1,
2001                                       "READ HEADER");
2002                 if (reply == 0)
2003                         reply = do_read_header(common, bh);
2004                 break;
2005
2006         case READ_TOC:
2007                 if (!common->curlun || !common->curlun->cdrom)
2008                         goto unknown_cmnd;
2009                 common->data_size_from_cmnd =
2010                         get_unaligned_be16(&common->cmnd[7]);
2011                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2012                                       (0xf<<6) | (3<<1), 1,
2013                                       "READ TOC");
2014                 if (reply == 0)
2015                         reply = do_read_toc(common, bh);
2016                 break;
2017
2018         case READ_FORMAT_CAPACITIES:
2019                 common->data_size_from_cmnd =
2020                         get_unaligned_be16(&common->cmnd[7]);
2021                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2022                                       (3<<7), 1,
2023                                       "READ FORMAT CAPACITIES");
2024                 if (reply == 0)
2025                         reply = do_read_format_capacities(common, bh);
2026                 break;
2027
2028         case REQUEST_SENSE:
2029                 common->data_size_from_cmnd = common->cmnd[4];
2030                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
2031                                       (1<<4), 0,
2032                                       "REQUEST SENSE");
2033                 if (reply == 0)
2034                         reply = do_request_sense(common, bh);
2035                 break;
2036
2037         case SERVICE_ACTION_IN_16:
2038                 switch (common->cmnd[1] & 0x1f) {
2039
2040                 case SAI_READ_CAPACITY_16:
2041                         common->data_size_from_cmnd =
2042                                 get_unaligned_be32(&common->cmnd[10]);
2043                         reply = check_command(common, 16, DATA_DIR_TO_HOST,
2044                                               (1<<1) | (0xff<<2) | (0xf<<10) |
2045                                               (1<<14), 1,
2046                                               "READ CAPACITY(16)");
2047                         if (reply == 0)
2048                                 reply = do_read_capacity_16(common, bh);
2049                         break;
2050
2051                 default:
2052                         goto unknown_cmnd;
2053                 }
2054                 break;
2055
2056         case START_STOP:
2057                 common->data_size_from_cmnd = 0;
2058                 reply = check_command(common, 6, DATA_DIR_NONE,
2059                                       (1<<1) | (1<<4), 0,
2060                                       "START-STOP UNIT");
2061                 if (reply == 0)
2062                         reply = do_start_stop(common);
2063                 break;
2064
2065         case SYNCHRONIZE_CACHE:
2066                 common->data_size_from_cmnd = 0;
2067                 reply = check_command(common, 10, DATA_DIR_NONE,
2068                                       (0xf<<2) | (3<<7), 1,
2069                                       "SYNCHRONIZE CACHE");
2070                 if (reply == 0)
2071                         reply = do_synchronize_cache(common);
2072                 break;
2073
2074         case TEST_UNIT_READY:
2075                 common->data_size_from_cmnd = 0;
2076                 reply = check_command(common, 6, DATA_DIR_NONE,
2077                                 0, 1,
2078                                 "TEST UNIT READY");
2079                 break;
2080
2081         /*
2082          * Although optional, this command is used by MS-Windows.  We
2083          * support a minimal version: BytChk must be 0.
2084          */
2085         case VERIFY:
2086                 common->data_size_from_cmnd = 0;
2087                 reply = check_command(common, 10, DATA_DIR_NONE,
2088                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2089                                       "VERIFY");
2090                 if (reply == 0)
2091                         reply = do_verify(common);
2092                 break;
2093
2094         case WRITE_6:
2095                 i = common->cmnd[4];
2096                 common->data_size_from_cmnd = (i == 0) ? 256 : i;
2097                 reply = check_command_size_in_blocks(common, 6,
2098                                       DATA_DIR_FROM_HOST,
2099                                       (7<<1) | (1<<4), 1,
2100                                       "WRITE(6)");
2101                 if (reply == 0)
2102                         reply = do_write(common);
2103                 break;
2104
2105         case WRITE_10:
2106                 common->data_size_from_cmnd =
2107                                 get_unaligned_be16(&common->cmnd[7]);
2108                 reply = check_command_size_in_blocks(common, 10,
2109                                       DATA_DIR_FROM_HOST,
2110                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2111                                       "WRITE(10)");
2112                 if (reply == 0)
2113                         reply = do_write(common);
2114                 break;
2115
2116         case WRITE_12:
2117                 common->data_size_from_cmnd =
2118                                 get_unaligned_be32(&common->cmnd[6]);
2119                 reply = check_command_size_in_blocks(common, 12,
2120                                       DATA_DIR_FROM_HOST,
2121                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
2122                                       "WRITE(12)");
2123                 if (reply == 0)
2124                         reply = do_write(common);
2125                 break;
2126
2127         case WRITE_16:
2128                 common->data_size_from_cmnd =
2129                                 get_unaligned_be32(&common->cmnd[10]);
2130                 reply = check_command_size_in_blocks(common, 16,
2131                                       DATA_DIR_FROM_HOST,
2132                                       (1<<1) | (0xff<<2) | (0xf<<10), 1,
2133                                       "WRITE(16)");
2134                 if (reply == 0)
2135                         reply = do_write(common);
2136                 break;
2137
2138         /*
2139          * Some mandatory commands that we recognize but don't implement.
2140          * They don't mean much in this setting.  It's left as an exercise
2141          * for anyone interested to implement RESERVE and RELEASE in terms
2142          * of Posix locks.
2143          */
2144         case FORMAT_UNIT:
2145         case RELEASE:
2146         case RESERVE:
2147         case SEND_DIAGNOSTIC:
2148
2149         default:
2150 unknown_cmnd:
2151                 common->data_size_from_cmnd = 0;
2152                 sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
2153                 reply = check_command(common, common->cmnd_size,
2154                                       DATA_DIR_UNKNOWN, ~0, 0, unknown);
2155                 if (reply == 0) {
2156                         common->curlun->sense_data = SS_INVALID_COMMAND;
2157                         reply = -EINVAL;
2158                 }
2159                 break;
2160         }
2161         up_read(&common->filesem);
2162
2163         if (reply == -EINTR || signal_pending(current))
2164                 return -EINTR;
2165
2166         /* Set up the single reply buffer for finish_reply() */
2167         if (reply == -EINVAL)
2168                 reply = 0;              /* Error reply length */
2169         if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
2170                 reply = min((u32)reply, common->data_size_from_cmnd);
2171                 bh->inreq->length = reply;
2172                 bh->state = BUF_STATE_FULL;
2173                 common->residue -= reply;
2174         }                               /* Otherwise it's already set */
2175
2176         return 0;
2177 }
2178
2179
2180 /*-------------------------------------------------------------------------*/
2181
2182 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2183 {
2184         struct usb_request      *req = bh->outreq;
2185         struct bulk_cb_wrap     *cbw = req->buf;
2186         struct fsg_common       *common = fsg->common;
2187
2188         /* Was this a real packet?  Should it be ignored? */
2189         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2190                 return -EINVAL;
2191
2192         /* Is the CBW valid? */
2193         if (req->actual != US_BULK_CB_WRAP_LEN ||
2194                         cbw->Signature != cpu_to_le32(
2195                                 US_BULK_CB_SIGN)) {
2196                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2197                                 req->actual,
2198                                 le32_to_cpu(cbw->Signature));
2199
2200                 /*
2201                  * The Bulk-only spec says we MUST stall the IN endpoint
2202                  * (6.6.1), so it's unavoidable.  It also says we must
2203                  * retain this state until the next reset, but there's
2204                  * no way to tell the controller driver it should ignore
2205                  * Clear-Feature(HALT) requests.
2206                  *
2207                  * We aren't required to halt the OUT endpoint; instead
2208                  * we can simply accept and discard any data received
2209                  * until the next reset.
2210                  */
2211                 wedge_bulk_in_endpoint(fsg);
2212                 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2213                 return -EINVAL;
2214         }
2215
2216         /* Is the CBW meaningful? */
2217         if (cbw->Lun >= ARRAY_SIZE(common->luns) ||
2218             cbw->Flags & ~US_BULK_FLAG_IN || cbw->Length <= 0 ||
2219             cbw->Length > MAX_COMMAND_SIZE) {
2220                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2221                                 "cmdlen %u\n",
2222                                 cbw->Lun, cbw->Flags, cbw->Length);
2223
2224                 /*
2225                  * We can do anything we want here, so let's stall the
2226                  * bulk pipes if we are allowed to.
2227                  */
2228                 if (common->can_stall) {
2229                         fsg_set_halt(fsg, fsg->bulk_out);
2230                         halt_bulk_in_endpoint(fsg);
2231                 }
2232                 return -EINVAL;
2233         }
2234
2235         /* Save the command for later */
2236         common->cmnd_size = cbw->Length;
2237         memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
2238         if (cbw->Flags & US_BULK_FLAG_IN)
2239                 common->data_dir = DATA_DIR_TO_HOST;
2240         else
2241                 common->data_dir = DATA_DIR_FROM_HOST;
2242         common->data_size = le32_to_cpu(cbw->DataTransferLength);
2243         if (common->data_size == 0)
2244                 common->data_dir = DATA_DIR_NONE;
2245         common->lun = cbw->Lun;
2246         if (common->lun < ARRAY_SIZE(common->luns))
2247                 common->curlun = common->luns[common->lun];
2248         else
2249                 common->curlun = NULL;
2250         common->tag = cbw->Tag;
2251         return 0;
2252 }
2253
2254 static int get_next_command(struct fsg_common *common)
2255 {
2256         struct fsg_buffhd       *bh;
2257         int                     rc = 0;
2258
2259         /* Wait for the next buffer to become available */
2260         bh = common->next_buffhd_to_fill;
2261         rc = sleep_thread(common, true, bh);
2262         if (rc)
2263                 return rc;
2264
2265         /* Queue a request to read a Bulk-only CBW */
2266         set_bulk_out_req_length(common, bh, US_BULK_CB_WRAP_LEN);
2267         if (!start_out_transfer(common, bh))
2268                 /* Don't know what to do if common->fsg is NULL */
2269                 return -EIO;
2270
2271         /*
2272          * We will drain the buffer in software, which means we
2273          * can reuse it for the next filling.  No need to advance
2274          * next_buffhd_to_fill.
2275          */
2276
2277         /* Wait for the CBW to arrive */
2278         rc = sleep_thread(common, true, bh);
2279         if (rc)
2280                 return rc;
2281
2282         rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
2283         bh->state = BUF_STATE_EMPTY;
2284
2285         return rc;
2286 }
2287
2288
2289 /*-------------------------------------------------------------------------*/
2290
2291 static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
2292                 struct usb_request **preq)
2293 {
2294         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2295         if (*preq)
2296                 return 0;
2297         ERROR(common, "can't allocate request for %s\n", ep->name);
2298         return -ENOMEM;
2299 }
2300
2301 /* Reset interface setting and re-init endpoint state (toggle etc). */
2302 static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
2303 {
2304         struct fsg_dev *fsg;
2305         int i, rc = 0;
2306
2307         if (common->running)
2308                 DBG(common, "reset interface\n");
2309
2310 reset:
2311         /* Deallocate the requests */
2312         if (common->fsg) {
2313                 fsg = common->fsg;
2314
2315                 for (i = 0; i < common->fsg_num_buffers; ++i) {
2316                         struct fsg_buffhd *bh = &common->buffhds[i];
2317
2318                         if (bh->inreq) {
2319                                 usb_ep_free_request(fsg->bulk_in, bh->inreq);
2320                                 bh->inreq = NULL;
2321                         }
2322                         if (bh->outreq) {
2323                                 usb_ep_free_request(fsg->bulk_out, bh->outreq);
2324                                 bh->outreq = NULL;
2325                         }
2326                 }
2327
2328                 /* Disable the endpoints */
2329                 if (fsg->bulk_in_enabled) {
2330                         usb_ep_disable(fsg->bulk_in);
2331                         fsg->bulk_in_enabled = 0;
2332                 }
2333                 if (fsg->bulk_out_enabled) {
2334                         usb_ep_disable(fsg->bulk_out);
2335                         fsg->bulk_out_enabled = 0;
2336                 }
2337
2338                 common->fsg = NULL;
2339                 wake_up(&common->fsg_wait);
2340         }
2341
2342         common->running = 0;
2343         if (!new_fsg || rc)
2344                 return rc;
2345
2346         common->fsg = new_fsg;
2347         fsg = common->fsg;
2348
2349         /* Enable the endpoints */
2350         rc = config_ep_by_speed(common->gadget, &(fsg->function), fsg->bulk_in);
2351         if (rc)
2352                 goto reset;
2353         rc = usb_ep_enable(fsg->bulk_in);
2354         if (rc)
2355                 goto reset;
2356         fsg->bulk_in->driver_data = common;
2357         fsg->bulk_in_enabled = 1;
2358
2359         rc = config_ep_by_speed(common->gadget, &(fsg->function),
2360                                 fsg->bulk_out);
2361         if (rc)
2362                 goto reset;
2363         rc = usb_ep_enable(fsg->bulk_out);
2364         if (rc)
2365                 goto reset;
2366         fsg->bulk_out->driver_data = common;
2367         fsg->bulk_out_enabled = 1;
2368         common->bulk_out_maxpacket = usb_endpoint_maxp(fsg->bulk_out->desc);
2369         clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2370
2371         /* Allocate the requests */
2372         for (i = 0; i < common->fsg_num_buffers; ++i) {
2373                 struct fsg_buffhd       *bh = &common->buffhds[i];
2374
2375                 rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
2376                 if (rc)
2377                         goto reset;
2378                 rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
2379                 if (rc)
2380                         goto reset;
2381                 bh->inreq->buf = bh->outreq->buf = bh->buf;
2382                 bh->inreq->context = bh->outreq->context = bh;
2383                 bh->inreq->complete = bulk_in_complete;
2384                 bh->outreq->complete = bulk_out_complete;
2385         }
2386
2387         common->running = 1;
2388         for (i = 0; i < ARRAY_SIZE(common->luns); ++i)
2389                 if (common->luns[i])
2390                         common->luns[i]->unit_attention_data =
2391                                 SS_RESET_OCCURRED;
2392         return rc;
2393 }
2394
2395
2396 /****************************** ALT CONFIGS ******************************/
2397
2398 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
2399 {
2400         struct fsg_dev *fsg = fsg_from_func(f);
2401
2402         __raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE, fsg);
2403         return USB_GADGET_DELAYED_STATUS;
2404 }
2405
2406 static void fsg_disable(struct usb_function *f)
2407 {
2408         struct fsg_dev *fsg = fsg_from_func(f);
2409
2410         /* Disable the endpoints */
2411         if (fsg->bulk_in_enabled) {
2412                 usb_ep_disable(fsg->bulk_in);
2413                 fsg->bulk_in_enabled = 0;
2414         }
2415         if (fsg->bulk_out_enabled) {
2416                 usb_ep_disable(fsg->bulk_out);
2417                 fsg->bulk_out_enabled = 0;
2418         }
2419
2420         __raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE, NULL);
2421 }
2422
2423
2424 /*-------------------------------------------------------------------------*/
2425
2426 static void handle_exception(struct fsg_common *common)
2427 {
2428         int                     i;
2429         struct fsg_buffhd       *bh;
2430         enum fsg_state          old_state;
2431         struct fsg_lun          *curlun;
2432         unsigned int            exception_req_tag;
2433         struct fsg_dev          *new_fsg;
2434
2435         /*
2436          * Clear the existing signals.  Anything but SIGUSR1 is converted
2437          * into a high-priority EXIT exception.
2438          */
2439         for (;;) {
2440                 int sig = kernel_dequeue_signal();
2441                 if (!sig)
2442                         break;
2443                 if (sig != SIGUSR1) {
2444                         spin_lock_irq(&common->lock);
2445                         if (common->state < FSG_STATE_EXIT)
2446                                 DBG(common, "Main thread exiting on signal\n");
2447                         common->state = FSG_STATE_EXIT;
2448                         spin_unlock_irq(&common->lock);
2449                 }
2450         }
2451
2452         /* Cancel all the pending transfers */
2453         if (likely(common->fsg)) {
2454                 for (i = 0; i < common->fsg_num_buffers; ++i) {
2455                         bh = &common->buffhds[i];
2456                         if (bh->state == BUF_STATE_SENDING)
2457                                 usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
2458                         if (bh->state == BUF_STATE_RECEIVING)
2459                                 usb_ep_dequeue(common->fsg->bulk_out,
2460                                                bh->outreq);
2461
2462                         /* Wait for a transfer to become idle */
2463                         if (sleep_thread(common, false, bh))
2464                                 return;
2465                 }
2466
2467                 /* Clear out the controller's fifos */
2468                 if (common->fsg->bulk_in_enabled)
2469                         usb_ep_fifo_flush(common->fsg->bulk_in);
2470                 if (common->fsg->bulk_out_enabled)
2471                         usb_ep_fifo_flush(common->fsg->bulk_out);
2472         }
2473
2474         /*
2475          * Reset the I/O buffer states and pointers, the SCSI
2476          * state, and the exception.  Then invoke the handler.
2477          */
2478         spin_lock_irq(&common->lock);
2479
2480         for (i = 0; i < common->fsg_num_buffers; ++i) {
2481                 bh = &common->buffhds[i];
2482                 bh->state = BUF_STATE_EMPTY;
2483         }
2484         common->next_buffhd_to_fill = &common->buffhds[0];
2485         common->next_buffhd_to_drain = &common->buffhds[0];
2486         exception_req_tag = common->exception_req_tag;
2487         new_fsg = common->exception_arg;
2488         old_state = common->state;
2489         common->state = FSG_STATE_NORMAL;
2490
2491         if (old_state != FSG_STATE_ABORT_BULK_OUT) {
2492                 for (i = 0; i < ARRAY_SIZE(common->luns); ++i) {
2493                         curlun = common->luns[i];
2494                         if (!curlun)
2495                                 continue;
2496                         curlun->prevent_medium_removal = 0;
2497                         curlun->sense_data = SS_NO_SENSE;
2498                         curlun->unit_attention_data = SS_NO_SENSE;
2499                         curlun->sense_data_info = 0;
2500                         curlun->info_valid = 0;
2501                 }
2502         }
2503         spin_unlock_irq(&common->lock);
2504
2505         /* Carry out any extra actions required for the exception */
2506         switch (old_state) {
2507         case FSG_STATE_NORMAL:
2508                 break;
2509
2510         case FSG_STATE_ABORT_BULK_OUT:
2511                 send_status(common);
2512                 break;
2513
2514         case FSG_STATE_PROTOCOL_RESET:
2515                 /*
2516                  * In case we were forced against our will to halt a
2517                  * bulk endpoint, clear the halt now.  (The SuperH UDC
2518                  * requires this.)
2519                  */
2520                 if (!fsg_is_set(common))
2521                         break;
2522                 if (test_and_clear_bit(IGNORE_BULK_OUT,
2523                                        &common->fsg->atomic_bitflags))
2524                         usb_ep_clear_halt(common->fsg->bulk_in);
2525
2526                 if (common->ep0_req_tag == exception_req_tag)
2527                         ep0_queue(common);      /* Complete the status stage */
2528
2529                 /*
2530                  * Technically this should go here, but it would only be
2531                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
2532                  * CONFIG_CHANGE cases.
2533                  */
2534                 /* for (i = 0; i < common->ARRAY_SIZE(common->luns); ++i) */
2535                 /*      if (common->luns[i]) */
2536                 /*              common->luns[i]->unit_attention_data = */
2537                 /*                      SS_RESET_OCCURRED;  */
2538                 break;
2539
2540         case FSG_STATE_CONFIG_CHANGE:
2541                 do_set_interface(common, new_fsg);
2542                 if (new_fsg)
2543                         usb_composite_setup_continue(common->cdev);
2544                 break;
2545
2546         case FSG_STATE_EXIT:
2547                 do_set_interface(common, NULL);         /* Free resources */
2548                 spin_lock_irq(&common->lock);
2549                 common->state = FSG_STATE_TERMINATED;   /* Stop the thread */
2550                 spin_unlock_irq(&common->lock);
2551                 break;
2552
2553         case FSG_STATE_TERMINATED:
2554                 break;
2555         }
2556 }
2557
2558
2559 /*-------------------------------------------------------------------------*/
2560
2561 static int fsg_main_thread(void *common_)
2562 {
2563         struct fsg_common       *common = common_;
2564         int                     i;
2565
2566         /*
2567          * Allow the thread to be killed by a signal, but set the signal mask
2568          * to block everything but INT, TERM, KILL, and USR1.
2569          */
2570         allow_signal(SIGINT);
2571         allow_signal(SIGTERM);
2572         allow_signal(SIGKILL);
2573         allow_signal(SIGUSR1);
2574
2575         /* Allow the thread to be frozen */
2576         set_freezable();
2577
2578         /* The main loop */
2579         while (common->state != FSG_STATE_TERMINATED) {
2580                 if (exception_in_progress(common) || signal_pending(current)) {
2581                         handle_exception(common);
2582                         continue;
2583                 }
2584
2585                 if (!common->running) {
2586                         sleep_thread(common, true, NULL);
2587                         continue;
2588                 }
2589
2590                 if (get_next_command(common) || exception_in_progress(common))
2591                         continue;
2592                 if (do_scsi_command(common) || exception_in_progress(common))
2593                         continue;
2594                 if (finish_reply(common) || exception_in_progress(common))
2595                         continue;
2596                 send_status(common);
2597         }
2598
2599         spin_lock_irq(&common->lock);
2600         common->thread_task = NULL;
2601         spin_unlock_irq(&common->lock);
2602
2603         /* Eject media from all LUNs */
2604
2605         down_write(&common->filesem);
2606         for (i = 0; i < ARRAY_SIZE(common->luns); i++) {
2607                 struct fsg_lun *curlun = common->luns[i];
2608
2609                 if (curlun && fsg_lun_is_open(curlun))
2610                         fsg_lun_close(curlun);
2611         }
2612         up_write(&common->filesem);
2613
2614         /* Let fsg_unbind() know the thread has exited */
2615         kthread_complete_and_exit(&common->thread_notifier, 0);
2616 }
2617
2618
2619 /*************************** DEVICE ATTRIBUTES ***************************/
2620
2621 static ssize_t ro_show(struct device *dev, struct device_attribute *attr, char *buf)
2622 {
2623         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2624
2625         return fsg_show_ro(curlun, buf);
2626 }
2627
2628 static ssize_t nofua_show(struct device *dev, struct device_attribute *attr,
2629                           char *buf)
2630 {
2631         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2632
2633         return fsg_show_nofua(curlun, buf);
2634 }
2635
2636 static ssize_t file_show(struct device *dev, struct device_attribute *attr,
2637                          char *buf)
2638 {
2639         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2640         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2641
2642         return fsg_show_file(curlun, filesem, buf);
2643 }
2644
2645 static ssize_t ro_store(struct device *dev, struct device_attribute *attr,
2646                         const char *buf, size_t count)
2647 {
2648         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2649         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2650
2651         return fsg_store_ro(curlun, filesem, buf, count);
2652 }
2653
2654 static ssize_t nofua_store(struct device *dev, struct device_attribute *attr,
2655                            const char *buf, size_t count)
2656 {
2657         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2658
2659         return fsg_store_nofua(curlun, buf, count);
2660 }
2661
2662 static ssize_t file_store(struct device *dev, struct device_attribute *attr,
2663                           const char *buf, size_t count)
2664 {
2665         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2666         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2667
2668         return fsg_store_file(curlun, filesem, buf, count);
2669 }
2670
2671 static ssize_t forced_eject_store(struct device *dev,
2672                                   struct device_attribute *attr,
2673                                   const char *buf, size_t count)
2674 {
2675         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2676         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2677
2678         return fsg_store_forced_eject(curlun, filesem, buf, count);
2679 }
2680
2681 static DEVICE_ATTR_RW(nofua);
2682 static DEVICE_ATTR_WO(forced_eject);
2683
2684 /*
2685  * Mode of the ro and file attribute files will be overridden in
2686  * fsg_lun_dev_is_visible() depending on if this is a cdrom, or if it is a
2687  * removable device.
2688  */
2689 static DEVICE_ATTR_RW(ro);
2690 static DEVICE_ATTR_RW(file);
2691
2692 /****************************** FSG COMMON ******************************/
2693
2694 static void fsg_lun_release(struct device *dev)
2695 {
2696         /* Nothing needs to be done */
2697 }
2698
2699 static struct fsg_common *fsg_common_setup(struct fsg_common *common)
2700 {
2701         if (!common) {
2702                 common = kzalloc(sizeof(*common), GFP_KERNEL);
2703                 if (!common)
2704                         return ERR_PTR(-ENOMEM);
2705                 common->free_storage_on_release = 1;
2706         } else {
2707                 common->free_storage_on_release = 0;
2708         }
2709         init_rwsem(&common->filesem);
2710         spin_lock_init(&common->lock);
2711         init_completion(&common->thread_notifier);
2712         init_waitqueue_head(&common->io_wait);
2713         init_waitqueue_head(&common->fsg_wait);
2714         common->state = FSG_STATE_TERMINATED;
2715         memset(common->luns, 0, sizeof(common->luns));
2716
2717         return common;
2718 }
2719
2720 void fsg_common_set_sysfs(struct fsg_common *common, bool sysfs)
2721 {
2722         common->sysfs = sysfs;
2723 }
2724 EXPORT_SYMBOL_GPL(fsg_common_set_sysfs);
2725
2726 static void _fsg_common_free_buffers(struct fsg_buffhd *buffhds, unsigned n)
2727 {
2728         if (buffhds) {
2729                 struct fsg_buffhd *bh = buffhds;
2730                 while (n--) {
2731                         kfree(bh->buf);
2732                         ++bh;
2733                 }
2734                 kfree(buffhds);
2735         }
2736 }
2737
2738 int fsg_common_set_num_buffers(struct fsg_common *common, unsigned int n)
2739 {
2740         struct fsg_buffhd *bh, *buffhds;
2741         int i;
2742
2743         buffhds = kcalloc(n, sizeof(*buffhds), GFP_KERNEL);
2744         if (!buffhds)
2745                 return -ENOMEM;
2746
2747         /* Data buffers cyclic list */
2748         bh = buffhds;
2749         i = n;
2750         goto buffhds_first_it;
2751         do {
2752                 bh->next = bh + 1;
2753                 ++bh;
2754 buffhds_first_it:
2755                 bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
2756                 if (unlikely(!bh->buf))
2757                         goto error_release;
2758         } while (--i);
2759         bh->next = buffhds;
2760
2761         _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);
2762         common->fsg_num_buffers = n;
2763         common->buffhds = buffhds;
2764
2765         return 0;
2766
2767 error_release:
2768         /*
2769          * "buf"s pointed to by heads after n - i are NULL
2770          * so releasing them won't hurt
2771          */
2772         _fsg_common_free_buffers(buffhds, n);
2773
2774         return -ENOMEM;
2775 }
2776 EXPORT_SYMBOL_GPL(fsg_common_set_num_buffers);
2777
2778 void fsg_common_remove_lun(struct fsg_lun *lun)
2779 {
2780         if (device_is_registered(&lun->dev))
2781                 device_unregister(&lun->dev);
2782         fsg_lun_close(lun);
2783         kfree(lun);
2784 }
2785 EXPORT_SYMBOL_GPL(fsg_common_remove_lun);
2786
2787 static void _fsg_common_remove_luns(struct fsg_common *common, int n)
2788 {
2789         int i;
2790
2791         for (i = 0; i < n; ++i)
2792                 if (common->luns[i]) {
2793                         fsg_common_remove_lun(common->luns[i]);
2794                         common->luns[i] = NULL;
2795                 }
2796 }
2797
2798 void fsg_common_remove_luns(struct fsg_common *common)
2799 {
2800         _fsg_common_remove_luns(common, ARRAY_SIZE(common->luns));
2801 }
2802 EXPORT_SYMBOL_GPL(fsg_common_remove_luns);
2803
2804 void fsg_common_free_buffers(struct fsg_common *common)
2805 {
2806         _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);
2807         common->buffhds = NULL;
2808 }
2809 EXPORT_SYMBOL_GPL(fsg_common_free_buffers);
2810
2811 int fsg_common_set_cdev(struct fsg_common *common,
2812                          struct usb_composite_dev *cdev, bool can_stall)
2813 {
2814         struct usb_string *us;
2815
2816         common->gadget = cdev->gadget;
2817         common->ep0 = cdev->gadget->ep0;
2818         common->ep0req = cdev->req;
2819         common->cdev = cdev;
2820
2821         us = usb_gstrings_attach(cdev, fsg_strings_array,
2822                                  ARRAY_SIZE(fsg_strings));
2823         if (IS_ERR(us))
2824                 return PTR_ERR(us);
2825
2826         fsg_intf_desc.iInterface = us[FSG_STRING_INTERFACE].id;
2827
2828         /*
2829          * Some peripheral controllers are known not to be able to
2830          * halt bulk endpoints correctly.  If one of them is present,
2831          * disable stalls.
2832          */
2833         common->can_stall = can_stall &&
2834                         gadget_is_stall_supported(common->gadget);
2835
2836         return 0;
2837 }
2838 EXPORT_SYMBOL_GPL(fsg_common_set_cdev);
2839
2840 static struct attribute *fsg_lun_dev_attrs[] = {
2841         &dev_attr_ro.attr,
2842         &dev_attr_file.attr,
2843         &dev_attr_nofua.attr,
2844         &dev_attr_forced_eject.attr,
2845         NULL
2846 };
2847
2848 static umode_t fsg_lun_dev_is_visible(struct kobject *kobj,
2849                                       struct attribute *attr, int idx)
2850 {
2851         struct device *dev = kobj_to_dev(kobj);
2852         struct fsg_lun *lun = fsg_lun_from_dev(dev);
2853
2854         if (attr == &dev_attr_ro.attr)
2855                 return lun->cdrom ? S_IRUGO : (S_IWUSR | S_IRUGO);
2856         if (attr == &dev_attr_file.attr)
2857                 return lun->removable ? (S_IWUSR | S_IRUGO) : S_IRUGO;
2858         return attr->mode;
2859 }
2860
2861 static const struct attribute_group fsg_lun_dev_group = {
2862         .attrs = fsg_lun_dev_attrs,
2863         .is_visible = fsg_lun_dev_is_visible,
2864 };
2865
2866 static const struct attribute_group *fsg_lun_dev_groups[] = {
2867         &fsg_lun_dev_group,
2868         NULL
2869 };
2870
2871 int fsg_common_create_lun(struct fsg_common *common, struct fsg_lun_config *cfg,
2872                           unsigned int id, const char *name,
2873                           const char **name_pfx)
2874 {
2875         struct fsg_lun *lun;
2876         char *pathbuf = NULL, *p = "(no medium)";
2877         int rc = -ENOMEM;
2878
2879         if (id >= ARRAY_SIZE(common->luns))
2880                 return -ENODEV;
2881
2882         if (common->luns[id])
2883                 return -EBUSY;
2884
2885         if (!cfg->filename && !cfg->removable) {
2886                 pr_err("no file given for LUN%d\n", id);
2887                 return -EINVAL;
2888         }
2889
2890         lun = kzalloc(sizeof(*lun), GFP_KERNEL);
2891         if (!lun)
2892                 return -ENOMEM;
2893
2894         lun->name_pfx = name_pfx;
2895
2896         lun->cdrom = !!cfg->cdrom;
2897         lun->ro = cfg->cdrom || cfg->ro;
2898         lun->initially_ro = lun->ro;
2899         lun->removable = !!cfg->removable;
2900
2901         if (!common->sysfs) {
2902                 /* we DON'T own the name!*/
2903                 lun->name = name;
2904         } else {
2905                 lun->dev.release = fsg_lun_release;
2906                 lun->dev.parent = &common->gadget->dev;
2907                 lun->dev.groups = fsg_lun_dev_groups;
2908                 dev_set_drvdata(&lun->dev, &common->filesem);
2909                 dev_set_name(&lun->dev, "%s", name);
2910                 lun->name = dev_name(&lun->dev);
2911
2912                 rc = device_register(&lun->dev);
2913                 if (rc) {
2914                         pr_info("failed to register LUN%d: %d\n", id, rc);
2915                         put_device(&lun->dev);
2916                         goto error_sysfs;
2917                 }
2918         }
2919
2920         common->luns[id] = lun;
2921
2922         if (cfg->filename) {
2923                 rc = fsg_lun_open(lun, cfg->filename);
2924                 if (rc)
2925                         goto error_lun;
2926
2927                 p = "(error)";
2928                 pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
2929                 if (pathbuf) {
2930                         p = file_path(lun->filp, pathbuf, PATH_MAX);
2931                         if (IS_ERR(p))
2932                                 p = "(error)";
2933                 }
2934         }
2935         pr_info("LUN: %s%s%sfile: %s\n",
2936               lun->removable ? "removable " : "",
2937               lun->ro ? "read only " : "",
2938               lun->cdrom ? "CD-ROM " : "",
2939               p);
2940         kfree(pathbuf);
2941
2942         return 0;
2943
2944 error_lun:
2945         if (device_is_registered(&lun->dev))
2946                 device_unregister(&lun->dev);
2947         common->luns[id] = NULL;
2948 error_sysfs:
2949         kfree(lun);
2950         return rc;
2951 }
2952 EXPORT_SYMBOL_GPL(fsg_common_create_lun);
2953
2954 int fsg_common_create_luns(struct fsg_common *common, struct fsg_config *cfg)
2955 {
2956         char buf[8]; /* enough for 100000000 different numbers, decimal */
2957         int i, rc;
2958
2959         fsg_common_remove_luns(common);
2960
2961         for (i = 0; i < cfg->nluns; ++i) {
2962                 snprintf(buf, sizeof(buf), "lun%d", i);
2963                 rc = fsg_common_create_lun(common, &cfg->luns[i], i, buf, NULL);
2964                 if (rc)
2965                         goto fail;
2966         }
2967
2968         pr_info("Number of LUNs=%d\n", cfg->nluns);
2969
2970         return 0;
2971
2972 fail:
2973         _fsg_common_remove_luns(common, i);
2974         return rc;
2975 }
2976 EXPORT_SYMBOL_GPL(fsg_common_create_luns);
2977
2978 void fsg_common_set_inquiry_string(struct fsg_common *common, const char *vn,
2979                                    const char *pn)
2980 {
2981         int i;
2982
2983         /* Prepare inquiryString */
2984         i = get_default_bcdDevice();
2985         snprintf(common->inquiry_string, sizeof(common->inquiry_string),
2986                  "%-8s%-16s%04x", vn ?: "Linux",
2987                  /* Assume product name dependent on the first LUN */
2988                  pn ?: ((*common->luns)->cdrom
2989                      ? "File-CD Gadget"
2990                      : "File-Stor Gadget"),
2991                  i);
2992 }
2993 EXPORT_SYMBOL_GPL(fsg_common_set_inquiry_string);
2994
2995 static void fsg_common_release(struct fsg_common *common)
2996 {
2997         int i;
2998
2999         /* If the thread isn't already dead, tell it to exit now */
3000         if (common->state != FSG_STATE_TERMINATED) {
3001                 raise_exception(common, FSG_STATE_EXIT);
3002                 wait_for_completion(&common->thread_notifier);
3003         }
3004
3005         for (i = 0; i < ARRAY_SIZE(common->luns); ++i) {
3006                 struct fsg_lun *lun = common->luns[i];
3007                 if (!lun)
3008                         continue;
3009                 fsg_lun_close(lun);
3010                 if (device_is_registered(&lun->dev))
3011                         device_unregister(&lun->dev);
3012                 kfree(lun);
3013         }
3014
3015         _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);
3016         if (common->free_storage_on_release)
3017                 kfree(common);
3018 }
3019
3020
3021 /*-------------------------------------------------------------------------*/
3022
3023 static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
3024 {
3025         struct fsg_dev          *fsg = fsg_from_func(f);
3026         struct fsg_common       *common = fsg->common;
3027         struct usb_gadget       *gadget = c->cdev->gadget;
3028         int                     i;
3029         struct usb_ep           *ep;
3030         unsigned                max_burst;
3031         int                     ret;
3032         struct fsg_opts         *opts;
3033
3034         /* Don't allow to bind if we don't have at least one LUN */
3035         ret = _fsg_common_get_max_lun(common);
3036         if (ret < 0) {
3037                 pr_err("There should be at least one LUN.\n");
3038                 return -EINVAL;
3039         }
3040
3041         opts = fsg_opts_from_func_inst(f->fi);
3042         if (!opts->no_configfs) {
3043                 ret = fsg_common_set_cdev(fsg->common, c->cdev,
3044                                           fsg->common->can_stall);
3045                 if (ret)
3046                         return ret;
3047                 fsg_common_set_inquiry_string(fsg->common, NULL, NULL);
3048         }
3049
3050         if (!common->thread_task) {
3051                 common->state = FSG_STATE_NORMAL;
3052                 common->thread_task =
3053                         kthread_create(fsg_main_thread, common, "file-storage");
3054                 if (IS_ERR(common->thread_task)) {
3055                         ret = PTR_ERR(common->thread_task);
3056                         common->thread_task = NULL;
3057                         common->state = FSG_STATE_TERMINATED;
3058                         return ret;
3059                 }
3060                 DBG(common, "I/O thread pid: %d\n",
3061                     task_pid_nr(common->thread_task));
3062                 wake_up_process(common->thread_task);
3063         }
3064
3065         fsg->gadget = gadget;
3066
3067         /* New interface */
3068         i = usb_interface_id(c, f);
3069         if (i < 0)
3070                 goto fail;
3071         fsg_intf_desc.bInterfaceNumber = i;
3072         fsg->interface_number = i;
3073
3074         /* Find all the endpoints we will use */
3075         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
3076         if (!ep)
3077                 goto autoconf_fail;
3078         fsg->bulk_in = ep;
3079
3080         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
3081         if (!ep)
3082                 goto autoconf_fail;
3083         fsg->bulk_out = ep;
3084
3085         /* Assume endpoint addresses are the same for both speeds */
3086         fsg_hs_bulk_in_desc.bEndpointAddress =
3087                 fsg_fs_bulk_in_desc.bEndpointAddress;
3088         fsg_hs_bulk_out_desc.bEndpointAddress =
3089                 fsg_fs_bulk_out_desc.bEndpointAddress;
3090
3091         /* Calculate bMaxBurst, we know packet size is 1024 */
3092         max_burst = min_t(unsigned, FSG_BUFLEN / 1024, 15);
3093
3094         fsg_ss_bulk_in_desc.bEndpointAddress =
3095                 fsg_fs_bulk_in_desc.bEndpointAddress;
3096         fsg_ss_bulk_in_comp_desc.bMaxBurst = max_burst;
3097
3098         fsg_ss_bulk_out_desc.bEndpointAddress =
3099                 fsg_fs_bulk_out_desc.bEndpointAddress;
3100         fsg_ss_bulk_out_comp_desc.bMaxBurst = max_burst;
3101
3102         ret = usb_assign_descriptors(f, fsg_fs_function, fsg_hs_function,
3103                         fsg_ss_function, fsg_ss_function);
3104         if (ret)
3105                 goto autoconf_fail;
3106
3107         return 0;
3108
3109 autoconf_fail:
3110         ERROR(fsg, "unable to autoconfigure all endpoints\n");
3111         i = -ENOTSUPP;
3112 fail:
3113         /* terminate the thread */
3114         if (fsg->common->state != FSG_STATE_TERMINATED) {
3115                 raise_exception(fsg->common, FSG_STATE_EXIT);
3116                 wait_for_completion(&fsg->common->thread_notifier);
3117         }
3118         return i;
3119 }
3120
3121 /****************************** ALLOCATE FUNCTION *************************/
3122
3123 static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
3124 {
3125         struct fsg_dev          *fsg = fsg_from_func(f);
3126         struct fsg_common       *common = fsg->common;
3127
3128         DBG(fsg, "unbind\n");
3129         if (fsg->common->fsg == fsg) {
3130                 __raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE, NULL);
3131                 /* FIXME: make interruptible or killable somehow? */
3132                 wait_event(common->fsg_wait, common->fsg != fsg);
3133         }
3134
3135         usb_free_all_descriptors(&fsg->function);
3136 }
3137
3138 static inline struct fsg_lun_opts *to_fsg_lun_opts(struct config_item *item)
3139 {
3140         return container_of(to_config_group(item), struct fsg_lun_opts, group);
3141 }
3142
3143 static inline struct fsg_opts *to_fsg_opts(struct config_item *item)
3144 {
3145         return container_of(to_config_group(item), struct fsg_opts,
3146                             func_inst.group);
3147 }
3148
3149 static void fsg_lun_attr_release(struct config_item *item)
3150 {
3151         struct fsg_lun_opts *lun_opts;
3152
3153         lun_opts = to_fsg_lun_opts(item);
3154         kfree(lun_opts);
3155 }
3156
3157 static struct configfs_item_operations fsg_lun_item_ops = {
3158         .release                = fsg_lun_attr_release,
3159 };
3160
3161 static ssize_t fsg_lun_opts_file_show(struct config_item *item, char *page)
3162 {
3163         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3164         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3165
3166         return fsg_show_file(opts->lun, &fsg_opts->common->filesem, page);
3167 }
3168
3169 static ssize_t fsg_lun_opts_file_store(struct config_item *item,
3170                                        const char *page, size_t len)
3171 {
3172         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3173         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3174
3175         return fsg_store_file(opts->lun, &fsg_opts->common->filesem, page, len);
3176 }
3177
3178 CONFIGFS_ATTR(fsg_lun_opts_, file);
3179
3180 static ssize_t fsg_lun_opts_ro_show(struct config_item *item, char *page)
3181 {
3182         return fsg_show_ro(to_fsg_lun_opts(item)->lun, page);
3183 }
3184
3185 static ssize_t fsg_lun_opts_ro_store(struct config_item *item,
3186                                        const char *page, size_t len)
3187 {
3188         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3189         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3190
3191         return fsg_store_ro(opts->lun, &fsg_opts->common->filesem, page, len);
3192 }
3193
3194 CONFIGFS_ATTR(fsg_lun_opts_, ro);
3195
3196 static ssize_t fsg_lun_opts_removable_show(struct config_item *item,
3197                                            char *page)
3198 {
3199         return fsg_show_removable(to_fsg_lun_opts(item)->lun, page);
3200 }
3201
3202 static ssize_t fsg_lun_opts_removable_store(struct config_item *item,
3203                                        const char *page, size_t len)
3204 {
3205         return fsg_store_removable(to_fsg_lun_opts(item)->lun, page, len);
3206 }
3207
3208 CONFIGFS_ATTR(fsg_lun_opts_, removable);
3209
3210 static ssize_t fsg_lun_opts_cdrom_show(struct config_item *item, char *page)
3211 {
3212         return fsg_show_cdrom(to_fsg_lun_opts(item)->lun, page);
3213 }
3214
3215 static ssize_t fsg_lun_opts_cdrom_store(struct config_item *item,
3216                                        const char *page, size_t len)
3217 {
3218         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3219         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3220
3221         return fsg_store_cdrom(opts->lun, &fsg_opts->common->filesem, page,
3222                                len);
3223 }
3224
3225 CONFIGFS_ATTR(fsg_lun_opts_, cdrom);
3226
3227 static ssize_t fsg_lun_opts_nofua_show(struct config_item *item, char *page)
3228 {
3229         return fsg_show_nofua(to_fsg_lun_opts(item)->lun, page);
3230 }
3231
3232 static ssize_t fsg_lun_opts_nofua_store(struct config_item *item,
3233                                        const char *page, size_t len)
3234 {
3235         return fsg_store_nofua(to_fsg_lun_opts(item)->lun, page, len);
3236 }
3237
3238 CONFIGFS_ATTR(fsg_lun_opts_, nofua);
3239
3240 static ssize_t fsg_lun_opts_inquiry_string_show(struct config_item *item,
3241                                                 char *page)
3242 {
3243         return fsg_show_inquiry_string(to_fsg_lun_opts(item)->lun, page);
3244 }
3245
3246 static ssize_t fsg_lun_opts_inquiry_string_store(struct config_item *item,
3247                                                  const char *page, size_t len)
3248 {
3249         return fsg_store_inquiry_string(to_fsg_lun_opts(item)->lun, page, len);
3250 }
3251
3252 CONFIGFS_ATTR(fsg_lun_opts_, inquiry_string);
3253
3254 static ssize_t fsg_lun_opts_forced_eject_store(struct config_item *item,
3255                                                const char *page, size_t len)
3256 {
3257         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3258         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3259
3260         return fsg_store_forced_eject(opts->lun, &fsg_opts->common->filesem,
3261                                       page, len);
3262 }
3263
3264 CONFIGFS_ATTR_WO(fsg_lun_opts_, forced_eject);
3265
3266 static struct configfs_attribute *fsg_lun_attrs[] = {
3267         &fsg_lun_opts_attr_file,
3268         &fsg_lun_opts_attr_ro,
3269         &fsg_lun_opts_attr_removable,
3270         &fsg_lun_opts_attr_cdrom,
3271         &fsg_lun_opts_attr_nofua,
3272         &fsg_lun_opts_attr_inquiry_string,
3273         &fsg_lun_opts_attr_forced_eject,
3274         NULL,
3275 };
3276
3277 static const struct config_item_type fsg_lun_type = {
3278         .ct_item_ops    = &fsg_lun_item_ops,
3279         .ct_attrs       = fsg_lun_attrs,
3280         .ct_owner       = THIS_MODULE,
3281 };
3282
3283 static struct config_group *fsg_lun_make(struct config_group *group,
3284                                          const char *name)
3285 {
3286         struct fsg_lun_opts *opts;
3287         struct fsg_opts *fsg_opts;
3288         struct fsg_lun_config config;
3289         char *num_str;
3290         u8 num;
3291         int ret;
3292
3293         num_str = strchr(name, '.');
3294         if (!num_str) {
3295                 pr_err("Unable to locate . in LUN.NUMBER\n");
3296                 return ERR_PTR(-EINVAL);
3297         }
3298         num_str++;
3299
3300         ret = kstrtou8(num_str, 0, &num);
3301         if (ret)
3302                 return ERR_PTR(ret);
3303
3304         fsg_opts = to_fsg_opts(&group->cg_item);
3305         if (num >= FSG_MAX_LUNS)
3306                 return ERR_PTR(-ERANGE);
3307         num = array_index_nospec(num, FSG_MAX_LUNS);
3308
3309         mutex_lock(&fsg_opts->lock);
3310         if (fsg_opts->refcnt || fsg_opts->common->luns[num]) {
3311                 ret = -EBUSY;
3312                 goto out;
3313         }
3314
3315         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3316         if (!opts) {
3317                 ret = -ENOMEM;
3318                 goto out;
3319         }
3320
3321         memset(&config, 0, sizeof(config));
3322         config.removable = true;
3323
3324         ret = fsg_common_create_lun(fsg_opts->common, &config, num, name,
3325                                     (const char **)&group->cg_item.ci_name);
3326         if (ret) {
3327                 kfree(opts);
3328                 goto out;
3329         }
3330         opts->lun = fsg_opts->common->luns[num];
3331         opts->lun_id = num;
3332         mutex_unlock(&fsg_opts->lock);
3333
3334         config_group_init_type_name(&opts->group, name, &fsg_lun_type);
3335
3336         return &opts->group;
3337 out:
3338         mutex_unlock(&fsg_opts->lock);
3339         return ERR_PTR(ret);
3340 }
3341
3342 static void fsg_lun_drop(struct config_group *group, struct config_item *item)
3343 {
3344         struct fsg_lun_opts *lun_opts;
3345         struct fsg_opts *fsg_opts;
3346
3347         lun_opts = to_fsg_lun_opts(item);
3348         fsg_opts = to_fsg_opts(&group->cg_item);
3349
3350         mutex_lock(&fsg_opts->lock);
3351         if (fsg_opts->refcnt) {
3352                 struct config_item *gadget;
3353
3354                 gadget = group->cg_item.ci_parent->ci_parent;
3355                 unregister_gadget_item(gadget);
3356         }
3357
3358         fsg_common_remove_lun(lun_opts->lun);
3359         fsg_opts->common->luns[lun_opts->lun_id] = NULL;
3360         lun_opts->lun_id = 0;
3361         mutex_unlock(&fsg_opts->lock);
3362
3363         config_item_put(item);
3364 }
3365
3366 static void fsg_attr_release(struct config_item *item)
3367 {
3368         struct fsg_opts *opts = to_fsg_opts(item);
3369
3370         usb_put_function_instance(&opts->func_inst);
3371 }
3372
3373 static struct configfs_item_operations fsg_item_ops = {
3374         .release                = fsg_attr_release,
3375 };
3376
3377 static ssize_t fsg_opts_stall_show(struct config_item *item, char *page)
3378 {
3379         struct fsg_opts *opts = to_fsg_opts(item);
3380         int result;
3381
3382         mutex_lock(&opts->lock);
3383         result = sprintf(page, "%d", opts->common->can_stall);
3384         mutex_unlock(&opts->lock);
3385
3386         return result;
3387 }
3388
3389 static ssize_t fsg_opts_stall_store(struct config_item *item, const char *page,
3390                                     size_t len)
3391 {
3392         struct fsg_opts *opts = to_fsg_opts(item);
3393         int ret;
3394         bool stall;
3395
3396         mutex_lock(&opts->lock);
3397
3398         if (opts->refcnt) {
3399                 mutex_unlock(&opts->lock);
3400                 return -EBUSY;
3401         }
3402
3403         ret = kstrtobool(page, &stall);
3404         if (!ret) {
3405                 opts->common->can_stall = stall;
3406                 ret = len;
3407         }
3408
3409         mutex_unlock(&opts->lock);
3410
3411         return ret;
3412 }
3413
3414 CONFIGFS_ATTR(fsg_opts_, stall);
3415
3416 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
3417 static ssize_t fsg_opts_num_buffers_show(struct config_item *item, char *page)
3418 {
3419         struct fsg_opts *opts = to_fsg_opts(item);
3420         int result;
3421
3422         mutex_lock(&opts->lock);
3423         result = sprintf(page, "%d", opts->common->fsg_num_buffers);
3424         mutex_unlock(&opts->lock);
3425
3426         return result;
3427 }
3428
3429 static ssize_t fsg_opts_num_buffers_store(struct config_item *item,
3430                                           const char *page, size_t len)
3431 {
3432         struct fsg_opts *opts = to_fsg_opts(item);
3433         int ret;
3434         u8 num;
3435
3436         mutex_lock(&opts->lock);
3437         if (opts->refcnt) {
3438                 ret = -EBUSY;
3439                 goto end;
3440         }
3441         ret = kstrtou8(page, 0, &num);
3442         if (ret)
3443                 goto end;
3444
3445         ret = fsg_common_set_num_buffers(opts->common, num);
3446         if (ret)
3447                 goto end;
3448         ret = len;
3449
3450 end:
3451         mutex_unlock(&opts->lock);
3452         return ret;
3453 }
3454
3455 CONFIGFS_ATTR(fsg_opts_, num_buffers);
3456 #endif
3457
3458 static struct configfs_attribute *fsg_attrs[] = {
3459         &fsg_opts_attr_stall,
3460 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
3461         &fsg_opts_attr_num_buffers,
3462 #endif
3463         NULL,
3464 };
3465
3466 static struct configfs_group_operations fsg_group_ops = {
3467         .make_group     = fsg_lun_make,
3468         .drop_item      = fsg_lun_drop,
3469 };
3470
3471 static const struct config_item_type fsg_func_type = {
3472         .ct_item_ops    = &fsg_item_ops,
3473         .ct_group_ops   = &fsg_group_ops,
3474         .ct_attrs       = fsg_attrs,
3475         .ct_owner       = THIS_MODULE,
3476 };
3477
3478 static void fsg_free_inst(struct usb_function_instance *fi)
3479 {
3480         struct fsg_opts *opts;
3481
3482         opts = fsg_opts_from_func_inst(fi);
3483         fsg_common_release(opts->common);
3484         kfree(opts);
3485 }
3486
3487 static struct usb_function_instance *fsg_alloc_inst(void)
3488 {
3489         struct fsg_opts *opts;
3490         struct fsg_lun_config config;
3491         int rc;
3492
3493         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3494         if (!opts)
3495                 return ERR_PTR(-ENOMEM);
3496         mutex_init(&opts->lock);
3497         opts->func_inst.free_func_inst = fsg_free_inst;
3498         opts->common = fsg_common_setup(opts->common);
3499         if (IS_ERR(opts->common)) {
3500                 rc = PTR_ERR(opts->common);
3501                 goto release_opts;
3502         }
3503
3504         rc = fsg_common_set_num_buffers(opts->common,
3505                                         CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS);
3506         if (rc)
3507                 goto release_common;
3508
3509         pr_info(FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
3510
3511         memset(&config, 0, sizeof(config));
3512         config.removable = true;
3513         rc = fsg_common_create_lun(opts->common, &config, 0, "lun.0",
3514                         (const char **)&opts->func_inst.group.cg_item.ci_name);
3515         if (rc)
3516                 goto release_buffers;
3517
3518         opts->lun0.lun = opts->common->luns[0];
3519         opts->lun0.lun_id = 0;
3520
3521         config_group_init_type_name(&opts->func_inst.group, "", &fsg_func_type);
3522
3523         config_group_init_type_name(&opts->lun0.group, "lun.0", &fsg_lun_type);
3524         configfs_add_default_group(&opts->lun0.group, &opts->func_inst.group);
3525
3526         return &opts->func_inst;
3527
3528 release_buffers:
3529         fsg_common_free_buffers(opts->common);
3530 release_common:
3531         kfree(opts->common);
3532 release_opts:
3533         kfree(opts);
3534         return ERR_PTR(rc);
3535 }
3536
3537 static void fsg_free(struct usb_function *f)
3538 {
3539         struct fsg_dev *fsg;
3540         struct fsg_opts *opts;
3541
3542         fsg = container_of(f, struct fsg_dev, function);
3543         opts = container_of(f->fi, struct fsg_opts, func_inst);
3544
3545         mutex_lock(&opts->lock);
3546         opts->refcnt--;
3547         mutex_unlock(&opts->lock);
3548
3549         kfree(fsg);
3550 }
3551
3552 static struct usb_function *fsg_alloc(struct usb_function_instance *fi)
3553 {
3554         struct fsg_opts *opts = fsg_opts_from_func_inst(fi);
3555         struct fsg_common *common = opts->common;
3556         struct fsg_dev *fsg;
3557
3558         fsg = kzalloc(sizeof(*fsg), GFP_KERNEL);
3559         if (unlikely(!fsg))
3560                 return ERR_PTR(-ENOMEM);
3561
3562         mutex_lock(&opts->lock);
3563         opts->refcnt++;
3564         mutex_unlock(&opts->lock);
3565
3566         fsg->function.name      = FSG_DRIVER_DESC;
3567         fsg->function.bind      = fsg_bind;
3568         fsg->function.unbind    = fsg_unbind;
3569         fsg->function.setup     = fsg_setup;
3570         fsg->function.set_alt   = fsg_set_alt;
3571         fsg->function.disable   = fsg_disable;
3572         fsg->function.free_func = fsg_free;
3573
3574         fsg->common               = common;
3575
3576         return &fsg->function;
3577 }
3578
3579 DECLARE_USB_FUNCTION_INIT(mass_storage, fsg_alloc_inst, fsg_alloc);
3580 MODULE_LICENSE("GPL");
3581 MODULE_AUTHOR("Michal Nazarewicz");
3582
3583 /************************* Module parameters *************************/
3584
3585
3586 void fsg_config_from_params(struct fsg_config *cfg,
3587                        const struct fsg_module_parameters *params,
3588                        unsigned int fsg_num_buffers)
3589 {
3590         struct fsg_lun_config *lun;
3591         unsigned i;
3592
3593         /* Configure LUNs */
3594         cfg->nluns =
3595                 min(params->luns ?: (params->file_count ?: 1u),
3596                     (unsigned)FSG_MAX_LUNS);
3597         for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) {
3598                 lun->ro = !!params->ro[i];
3599                 lun->cdrom = !!params->cdrom[i];
3600                 lun->removable = !!params->removable[i];
3601                 lun->filename =
3602                         params->file_count > i && params->file[i][0]
3603                         ? params->file[i]
3604                         : NULL;
3605         }
3606
3607         /* Let MSF use defaults */
3608         cfg->vendor_name = NULL;
3609         cfg->product_name = NULL;
3610
3611         cfg->ops = NULL;
3612         cfg->private_data = NULL;
3613
3614         /* Finalise */
3615         cfg->can_stall = params->stall;
3616         cfg->fsg_num_buffers = fsg_num_buffers;
3617 }
3618 EXPORT_SYMBOL_GPL(fsg_config_from_params);