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/kthread.h>
 180 #include <linux/sched/signal.h>
 181 #include <linux/limits.h>
 182 #include <linux/pagemap.h>
 183 #include <linux/rwsem.h>
 184 #include <linux/slab.h>
 185 #include <linux/spinlock.h>
 186 #include <linux/string.h>
 187 #include <linux/freezer.h>
 188 #include <linux/module.h>
 189 #include <linux/uaccess.h>
 190 #include <asm/unaligned.h>
 191
 192 #include <linux/usb/ch9.h>
 193 #include <linux/usb/gadget.h>
 194 #include <linux/usb/composite.h>
 195
 196 #include <linux/nospec.h>
 197
 198 #include "configfs.h"
 199
 200
 201 /*------------------------------------------------------------------------*/
 202
 203 #define FSG_DRIVER_DESC         "Mass Storage Function"
 204 #define FSG_DRIVER_VERSION      "2009/09/11"
 205
 206 static const char fsg_string_interface[] = "Mass Storage";
 207
 208 #include "storage_common.h"
 209 #include "f_mass_storage.h"
 210
 211 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
 212 static struct usb_string                fsg_strings[] = {
 213         {FSG_STRING_INTERFACE,          fsg_string_interface},
 214         {}
 215 };
 216
 217 static struct usb_gadget_strings        fsg_stringtab = {
 218         .language       = 0x0409,               /* en-us */
 219         .strings        = fsg_strings,
 220 };
 221
 222 static struct usb_gadget_strings *fsg_strings_array[] = {
 223         &fsg_stringtab,
 224         NULL,
 225 };
 226
 227 /*-------------------------------------------------------------------------*/
 228
 229 struct fsg_dev;
 230 struct fsg_common;
 231
 232 /* Data shared by all the FSG instances. */
 233 struct fsg_common {
 234         struct usb_gadget       *gadget;
 235         struct usb_composite_dev *cdev;
 236         struct fsg_dev          *fsg;
 237         wait_queue_head_t       io_wait;
 238         wait_queue_head_t       fsg_wait;
 239
 240         /* filesem protects: backing files in use */
 241         struct rw_semaphore     filesem;
 242
 243         /* lock protects: state and thread_task */
 244         spinlock_t              lock;
 245
 246         struct usb_ep           *ep0;           /* Copy of gadget->ep0 */
 247         struct usb_request      *ep0req;        /* Copy of cdev->req */
 248         unsigned int            ep0_req_tag;
 249
 250         struct fsg_buffhd       *next_buffhd_to_fill;
 251         struct fsg_buffhd       *next_buffhd_to_drain;
 252         struct fsg_buffhd       *buffhds;
 253         unsigned int            fsg_num_buffers;
 254
 255         int                     cmnd_size;
 256         u8                      cmnd[MAX_COMMAND_SIZE];
 257
 258         unsigned int            lun;
 259         struct fsg_lun          *luns[FSG_MAX_LUNS];
 260         struct fsg_lun          *curlun;
 261
 262         unsigned int            bulk_out_maxpacket;
 263         enum fsg_state          state;          /* For exception handling */
 264         unsigned int            exception_req_tag;
 265         void                    *exception_arg;
 266
 267         enum data_direction     data_dir;
 268         u32                     data_size;
 269         u32                     data_size_from_cmnd;
 270         u32                     tag;
 271         u32                     residue;
 272         u32                     usb_amount_left;
 273
 274         unsigned int            can_stall:1;
 275         unsigned int            free_storage_on_release:1;
 276         unsigned int            phase_error:1;
 277         unsigned int            short_packet_received:1;
 278         unsigned int            bad_lun_okay:1;
 279         unsigned int            running:1;
 280         unsigned int            sysfs:1;
 281
 282         struct completion       thread_notifier;
 283         struct task_struct      *thread_task;
 284
 285         /* Gadget's private data. */
 286         void                    *private_data;
 287
 288         char inquiry_string[INQUIRY_STRING_LEN];
 289 };
 290
 291 struct fsg_dev {
 292         struct usb_function     function;
 293         struct usb_gadget       *gadget;        /* Copy of cdev->gadget */
 294         struct fsg_common       *common;
 295
 296         u16                     interface_number;
 297
 298         unsigned int            bulk_in_enabled:1;
 299         unsigned int            bulk_out_enabled:1;
 300
 301         unsigned long           atomic_bitflags;
 302 #define IGNORE_BULK_OUT         0
 303
 304         struct usb_ep           *bulk_in;
 305         struct usb_ep           *bulk_out;
 306 };
 307
 308 static inline int __fsg_is_set(struct fsg_common *common,
 309                                const char *func, unsigned line)
 310 {
 311         if (common->fsg)
 312                 return 1;
 313         ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
 314         WARN_ON(1);
 315         return 0;
 316 }
 317
 318 #define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
 319
 320 static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
 321 {
 322         return container_of(f, struct fsg_dev, function);
 323 }
 324
 325 static int exception_in_progress(struct fsg_common *common)
 326 {
 327         return common->state > FSG_STATE_NORMAL;
 328 }
 329
 330 /* Make bulk-out requests be divisible by the maxpacket size */
 331 static void set_bulk_out_req_length(struct fsg_common *common,
 332                                     struct fsg_buffhd *bh, unsigned int length)
 333 {
 334         unsigned int    rem;
 335
 336         bh->bulk_out_intended_length = length;
 337         rem = length % common->bulk_out_maxpacket;
 338         if (rem > 0)
 339                 length += common->bulk_out_maxpacket - rem;
 340         bh->outreq->length = length;
 341 }
 342
 343
 344 /*-------------------------------------------------------------------------*/
 345
 346 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
 347 {
 348         const char      *name;
 349
 350         if (ep == fsg->bulk_in)
 351                 name = "bulk-in";
 352         else if (ep == fsg->bulk_out)
 353                 name = "bulk-out";
 354         else
 355                 name = ep->name;
 356         DBG(fsg, "%s set halt\n", name);
 357         return usb_ep_set_halt(ep);
 358 }
 359
 360
 361 /*-------------------------------------------------------------------------*/
 362
 363 /* These routines may be called in process context or in_irq */
 364
 365 static void __raise_exception(struct fsg_common *common, enum fsg_state new_state,
 366                               void *arg)
 367 {
 368         unsigned long           flags;
 369
 370         /*
 371          * Do nothing if a higher-priority exception is already in progress.
 372          * If a lower-or-equal priority exception is in progress, preempt it
 373          * and notify the main thread by sending it a signal.
 374          */
 375         spin_lock_irqsave(&common->lock, flags);
 376         if (common->state <= new_state) {
 377                 common->exception_req_tag = common->ep0_req_tag;
 378                 common->state = new_state;
 379                 common->exception_arg = arg;
 380                 if (common->thread_task)
 381                         send_sig_info(SIGUSR1, SEND_SIG_PRIV,
 382                                       common->thread_task);
 383         }
 384         spin_unlock_irqrestore(&common->lock, flags);
 385 }
 386
 387 static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
 388 {
 389         __raise_exception(common, new_state, NULL);
 390 }
 391
 392 /*-------------------------------------------------------------------------*/
 393
 394 static int ep0_queue(struct fsg_common *common)
 395 {
 396         int     rc;
 397
 398         rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
 399         common->ep0->driver_data = common;
 400         if (rc != 0 && rc != -ESHUTDOWN) {
 401                 /* We can't do much more than wait for a reset */
 402                 WARNING(common, "error in submission: %s --> %d\n",
 403                         common->ep0->name, rc);
 404         }
 405         return rc;
 406 }
 407
 408
 409 /*-------------------------------------------------------------------------*/
 410
 411 /* Completion handlers. These always run in_irq. */
 412
 413 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
 414 {
 415         struct fsg_common       *common = ep->driver_data;
 416         struct fsg_buffhd       *bh = req->context;
 417
 418         if (req->status || req->actual != req->length)
 419                 DBG(common, "%s --> %d, %u/%u\n", __func__,
 420                     req->status, req->actual, req->length);
 421         if (req->status == -ECONNRESET)         /* Request was cancelled */
 422                 usb_ep_fifo_flush(ep);
 423
 424         /* Synchronize with the smp_load_acquire() in sleep_thread() */
 425         smp_store_release(&bh->state, BUF_STATE_EMPTY);
 426         wake_up(&common->io_wait);
 427 }
 428
 429 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
 430 {
 431         struct fsg_common       *common = ep->driver_data;
 432         struct fsg_buffhd       *bh = req->context;
 433
 434         dump_msg(common, "bulk-out", req->buf, req->actual);
 435         if (req->status || req->actual != bh->bulk_out_intended_length)
 436                 DBG(common, "%s --> %d, %u/%u\n", __func__,
 437                     req->status, req->actual, bh->bulk_out_intended_length);
 438         if (req->status == -ECONNRESET)         /* Request was cancelled */
 439                 usb_ep_fifo_flush(ep);
 440
 441         /* Synchronize with the smp_load_acquire() in sleep_thread() */
 442         smp_store_release(&bh->state, BUF_STATE_FULL);
 443         wake_up(&common->io_wait);
 444 }
 445
 446 static int _fsg_common_get_max_lun(struct fsg_common *common)
 447 {
 448         int i = ARRAY_SIZE(common->luns) - 1;
 449
 450         while (i >= 0 && !common->luns[i])
 451                 --i;
 452
 453         return i;
 454 }
 455
 456 static int fsg_setup(struct usb_function *f,
 457                      const struct usb_ctrlrequest *ctrl)
 458 {
 459         struct fsg_dev          *fsg = fsg_from_func(f);
 460         struct usb_request      *req = fsg->common->ep0req;
 461         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 462         u16                     w_value = le16_to_cpu(ctrl->wValue);
 463         u16                     w_length = le16_to_cpu(ctrl->wLength);
 464
 465         if (!fsg_is_set(fsg->common))
 466                 return -EOPNOTSUPP;
 467
 468         ++fsg->common->ep0_req_tag;     /* Record arrival of a new request */
 469         req->context = NULL;
 470         req->length = 0;
 471         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
 472
 473         switch (ctrl->bRequest) {
 474
 475         case US_BULK_RESET_REQUEST:
 476                 if (ctrl->bRequestType !=
 477                     (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 478                         break;
 479                 if (w_index != fsg->interface_number || w_value != 0 ||
 480                                 w_length != 0)
 481                         return -EDOM;
 482
 483                 /*
 484                  * Raise an exception to stop the current operation
 485                  * and reinitialize our state.
 486                  */
 487                 DBG(fsg, "bulk reset request\n");
 488                 raise_exception(fsg->common, FSG_STATE_PROTOCOL_RESET);
 489                 return USB_GADGET_DELAYED_STATUS;
 490
 491         case US_BULK_GET_MAX_LUN:
 492                 if (ctrl->bRequestType !=
 493                     (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 494                         break;
 495                 if (w_index != fsg->interface_number || w_value != 0 ||
 496                                 w_length != 1)
 497                         return -EDOM;
 498                 VDBG(fsg, "get max LUN\n");
 499                 *(u8 *)req->buf = _fsg_common_get_max_lun(fsg->common);
 500
 501                 /* Respond with data/status */
 502                 req->length = min((u16)1, w_length);
 503                 return ep0_queue(fsg->common);
 504         }
 505
 506         VDBG(fsg,
 507              "unknown class-specific control req %02x.%02x v%04x i%04x l%u\n",
 508              ctrl->bRequestType, ctrl->bRequest,
 509              le16_to_cpu(ctrl->wValue), w_index, w_length);
 510         return -EOPNOTSUPP;
 511 }
 512
 513
 514 /*-------------------------------------------------------------------------*/
 515
 516 /* All the following routines run in process context */
 517
 518 /* Use this for bulk or interrupt transfers, not ep0 */
 519 static int start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
 520                            struct usb_request *req)
 521 {
 522         int     rc;
 523
 524         if (ep == fsg->bulk_in)
 525                 dump_msg(fsg, "bulk-in", req->buf, req->length);
 526
 527         rc = usb_ep_queue(ep, req, GFP_KERNEL);
 528         if (rc) {
 529
 530                 /* We can't do much more than wait for a reset */
 531                 req->status = rc;
 532
 533                 /*
 534                  * Note: currently the net2280 driver fails zero-length
 535                  * submissions if DMA is enabled.
 536                  */
 537                 if (rc != -ESHUTDOWN &&
 538                                 !(rc == -EOPNOTSUPP && req->length == 0))
 539                         WARNING(fsg, "error in submission: %s --> %d\n",
 540                                         ep->name, rc);
 541         }
 542         return rc;
 543 }
 544
 545 static bool start_in_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
 546 {
 547         if (!fsg_is_set(common))
 548                 return false;
 549         bh->state = BUF_STATE_SENDING;
 550         if (start_transfer(common->fsg, common->fsg->bulk_in, bh->inreq))
 551                 bh->state = BUF_STATE_EMPTY;
 552         return true;
 553 }
 554
 555 static bool start_out_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
 556 {
 557         if (!fsg_is_set(common))
 558                 return false;
 559         bh->state = BUF_STATE_RECEIVING;
 560         if (start_transfer(common->fsg, common->fsg->bulk_out, bh->outreq))
 561                 bh->state = BUF_STATE_FULL;
 562         return true;
 563 }
 564
 565 static int sleep_thread(struct fsg_common *common, bool can_freeze,
 566                 struct fsg_buffhd *bh)
 567 {
 568         int     rc;
 569
 570         /* Wait until a signal arrives or bh is no longer busy */
 571         if (can_freeze)
 572                 /*
 573                  * synchronize with the smp_store_release(&bh->state) in
 574                  * bulk_in_complete() or bulk_out_complete()
 575                  */
 576                 rc = wait_event_freezable(common->io_wait,
 577                                 bh && smp_load_acquire(&bh->state) >=
 578                                         BUF_STATE_EMPTY);
 579         else
 580                 rc = wait_event_interruptible(common->io_wait,
 581                                 bh && smp_load_acquire(&bh->state) >=
 582                                         BUF_STATE_EMPTY);
 583         return rc ? -EINTR : 0;
 584 }
 585
 586
 587 /*-------------------------------------------------------------------------*/
 588
 589 static int do_read(struct fsg_common *common)
 590 {
 591         struct fsg_lun          *curlun = common->curlun;
 592         u64                     lba;
 593         struct fsg_buffhd       *bh;
 594         int                     rc;
 595         u32                     amount_left;
 596         loff_t                  file_offset, file_offset_tmp;
 597         unsigned int            amount;
 598         ssize_t                 nread;
 599
 600         /*
 601          * Get the starting Logical Block Address and check that it's
 602          * not too big.
 603          */
 604         if (common->cmnd[0] == READ_6)
 605                 lba = get_unaligned_be24(&common->cmnd[1]);
 606         else {
 607                 if (common->cmnd[0] == READ_16)
 608                         lba = get_unaligned_be64(&common->cmnd[2]);
 609                 else            /* READ_10 or READ_12 */
 610                         lba = get_unaligned_be32(&common->cmnd[2]);
 611
 612                 /*
 613                  * We allow DPO (Disable Page Out = don't save data in the
 614                  * cache) and FUA (Force Unit Access = don't read from the
 615                  * cache), but we don't implement them.
 616                  */
 617                 if ((common->cmnd[1] & ~0x18) != 0) {
 618                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
 619                         return -EINVAL;
 620                 }
 621         }
 622         if (lba >= curlun->num_sectors) {
 623                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 624                 return -EINVAL;
 625         }
 626         file_offset = ((loff_t) lba) << curlun->blkbits;
 627
 628         /* Carry out the file reads */
 629         amount_left = common->data_size_from_cmnd;
 630         if (unlikely(amount_left == 0))
 631                 return -EIO;            /* No default reply */
 632
 633         for (;;) {
 634                 /*
 635                  * Figure out how much we need to read:
 636                  * Try to read the remaining amount.
 637                  * But don't read more than the buffer size.
 638                  * And don't try to read past the end of the file.
 639                  */
 640                 amount = min(amount_left, FSG_BUFLEN);
 641                 amount = min((loff_t)amount,
 642                              curlun->file_length - file_offset);
 643
 644                 /* Wait for the next buffer to become available */
 645                 bh = common->next_buffhd_to_fill;
 646                 rc = sleep_thread(common, false, bh);
 647                 if (rc)
 648                         return rc;
 649
 650                 /*
 651                  * If we were asked to read past the end of file,
 652                  * end with an empty buffer.
 653                  */
 654                 if (amount == 0) {
 655                         curlun->sense_data =
 656                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 657                         curlun->sense_data_info =
 658                                         file_offset >> curlun->blkbits;
 659                         curlun->info_valid = 1;
 660                         bh->inreq->length = 0;
 661                         bh->state = BUF_STATE_FULL;
 662                         break;
 663                 }
 664
 665                 /* Perform the read */
 666                 file_offset_tmp = file_offset;
 667                 nread = kernel_read(curlun->filp, bh->buf, amount,
 668                                 &file_offset_tmp);
 669                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
 670                       (unsigned long long)file_offset, (int)nread);
 671                 if (signal_pending(current))
 672                         return -EINTR;
 673
 674                 if (nread < 0) {
 675                         LDBG(curlun, "error in file read: %d\n", (int)nread);
 676                         nread = 0;
 677                 } else if (nread < amount) {
 678                         LDBG(curlun, "partial file read: %d/%u\n",
 679                              (int)nread, amount);
 680                         nread = round_down(nread, curlun->blksize);
 681                 }
 682                 file_offset  += nread;
 683                 amount_left  -= nread;
 684                 common->residue -= nread;
 685
 686                 /*
 687                  * Except at the end of the transfer, nread will be
 688                  * equal to the buffer size, which is divisible by the
 689                  * bulk-in maxpacket size.
 690                  */
 691                 bh->inreq->length = nread;
 692                 bh->state = BUF_STATE_FULL;
 693
 694                 /* If an error occurred, report it and its position */
 695                 if (nread < amount) {
 696                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
 697                         curlun->sense_data_info =
 698                                         file_offset >> curlun->blkbits;
 699                         curlun->info_valid = 1;
 700                         break;
 701                 }
 702
 703                 if (amount_left == 0)
 704                         break;          /* No more left to read */
 705
 706                 /* Send this buffer and go read some more */
 707                 bh->inreq->zero = 0;
 708                 if (!start_in_transfer(common, bh))
 709                         /* Don't know what to do if common->fsg is NULL */
 710                         return -EIO;
 711                 common->next_buffhd_to_fill = bh->next;
 712         }
 713
 714         return -EIO;            /* No default reply */
 715 }
 716
 717
 718 /*-------------------------------------------------------------------------*/
 719
 720 static int do_write(struct fsg_common *common)
 721 {
 722         struct fsg_lun          *curlun = common->curlun;
 723         u64                     lba;
 724         struct fsg_buffhd       *bh;
 725         int                     get_some_more;
 726         u32                     amount_left_to_req, amount_left_to_write;
 727         loff_t                  usb_offset, file_offset, file_offset_tmp;
 728         unsigned int            amount;
 729         ssize_t                 nwritten;
 730         int                     rc;
 731
 732         if (curlun->ro) {
 733                 curlun->sense_data = SS_WRITE_PROTECTED;
 734                 return -EINVAL;
 735         }
 736         spin_lock(&curlun->filp->f_lock);
 737         curlun->filp->f_flags &= ~O_SYNC;       /* Default is not to wait */
 738         spin_unlock(&curlun->filp->f_lock);
 739
 740         /*
 741          * Get the starting Logical Block Address and check that it's
 742          * not too big
 743          */
 744         if (common->cmnd[0] == WRITE_6)
 745                 lba = get_unaligned_be24(&common->cmnd[1]);
 746         else {
 747                 if (common->cmnd[0] == WRITE_16)
 748                         lba = get_unaligned_be64(&common->cmnd[2]);
 749                 else            /* WRITE_10 or WRITE_12 */
 750                         lba = get_unaligned_be32(&common->cmnd[2]);
 751
 752                 /*
 753                  * We allow DPO (Disable Page Out = don't save data in the
 754                  * cache) and FUA (Force Unit Access = write directly to the
 755                  * medium).  We don't implement DPO; we implement FUA by
 756                  * performing synchronous output.
 757                  */
 758                 if (common->cmnd[1] & ~0x18) {
 759                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
 760                         return -EINVAL;
 761                 }
 762                 if (!curlun->nofua && (common->cmnd[1] & 0x08)) { /* FUA */
 763                         spin_lock(&curlun->filp->f_lock);
 764                         curlun->filp->f_flags |= O_SYNC;
 765                         spin_unlock(&curlun->filp->f_lock);
 766                 }
 767         }
 768         if (lba >= curlun->num_sectors) {
 769                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 770                 return -EINVAL;
 771         }
 772
 773         /* Carry out the file writes */
 774         get_some_more = 1;
 775         file_offset = usb_offset = ((loff_t) lba) << curlun->blkbits;
 776         amount_left_to_req = common->data_size_from_cmnd;
 777         amount_left_to_write = common->data_size_from_cmnd;
 778
 779         while (amount_left_to_write > 0) {
 780
 781                 /* Queue a request for more data from the host */
 782                 bh = common->next_buffhd_to_fill;
 783                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
 784
 785                         /*
 786                          * Figure out how much we want to get:
 787                          * Try to get the remaining amount,
 788                          * but not more than the buffer size.
 789                          */
 790                         amount = min(amount_left_to_req, FSG_BUFLEN);
 791
 792                         /* Beyond the end of the backing file? */
 793                         if (usb_offset >= curlun->file_length) {
 794                                 get_some_more = 0;
 795                                 curlun->sense_data =
 796                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 797                                 curlun->sense_data_info =
 798                                         usb_offset >> curlun->blkbits;
 799                                 curlun->info_valid = 1;
 800                                 continue;
 801                         }
 802
 803                         /* Get the next buffer */
 804                         usb_offset += amount;
 805                         common->usb_amount_left -= amount;
 806                         amount_left_to_req -= amount;
 807                         if (amount_left_to_req == 0)
 808                                 get_some_more = 0;
 809
 810                         /*
 811                          * Except at the end of the transfer, amount will be
 812                          * equal to the buffer size, which is divisible by
 813                          * the bulk-out maxpacket size.
 814                          */
 815                         set_bulk_out_req_length(common, bh, amount);
 816                         if (!start_out_transfer(common, bh))
 817                                 /* Dunno what to do if common->fsg is NULL */
 818                                 return -EIO;
 819                         common->next_buffhd_to_fill = bh->next;
 820                         continue;
 821                 }
 822
 823                 /* Write the received data to the backing file */
 824                 bh = common->next_buffhd_to_drain;
 825                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
 826                         break;                  /* We stopped early */
 827
 828                 /* Wait for the data to be received */
 829                 rc = sleep_thread(common, false, bh);
 830                 if (rc)
 831                         return rc;
 832
 833                 common->next_buffhd_to_drain = bh->next;
 834                 bh->state = BUF_STATE_EMPTY;
 835
 836                 /* Did something go wrong with the transfer? */
 837                 if (bh->outreq->status != 0) {
 838                         curlun->sense_data = SS_COMMUNICATION_FAILURE;
 839                         curlun->sense_data_info =
 840                                         file_offset >> curlun->blkbits;
 841                         curlun->info_valid = 1;
 842                         break;
 843                 }
 844
 845                 amount = bh->outreq->actual;
 846                 if (curlun->file_length - file_offset < amount) {
 847                         LERROR(curlun, "write %u @ %llu beyond end %llu\n",
 848                                        amount, (unsigned long long)file_offset,
 849                                        (unsigned long long)curlun->file_length);
 850                         amount = curlun->file_length - file_offset;
 851                 }
 852
 853                 /*
 854                  * Don't accept excess data.  The spec doesn't say
 855                  * what to do in this case.  We'll ignore the error.
 856                  */
 857                 amount = min(amount, bh->bulk_out_intended_length);
 858
 859                 /* Don't write a partial block */
 860                 amount = round_down(amount, curlun->blksize);
 861                 if (amount == 0)
 862                         goto empty_write;
 863
 864                 /* Perform the write */
 865                 file_offset_tmp = file_offset;
 866                 nwritten = kernel_write(curlun->filp, bh->buf, amount,
 867                                 &file_offset_tmp);
 868                 VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
 869                                 (unsigned long long)file_offset, (int)nwritten);
 870                 if (signal_pending(current))
 871                         return -EINTR;          /* Interrupted! */
 872
 873                 if (nwritten < 0) {
 874                         LDBG(curlun, "error in file write: %d\n",
 875                                         (int) nwritten);
 876                         nwritten = 0;
 877                 } else if (nwritten < amount) {
 878                         LDBG(curlun, "partial file write: %d/%u\n",
 879                                         (int) nwritten, amount);
 880                         nwritten = round_down(nwritten, curlun->blksize);
 881                 }
 882                 file_offset += nwritten;
 883                 amount_left_to_write -= nwritten;
 884                 common->residue -= nwritten;
 885
 886                 /* If an error occurred, report it and its position */
 887                 if (nwritten < amount) {
 888                         curlun->sense_data = SS_WRITE_ERROR;
 889                         curlun->sense_data_info =
 890                                         file_offset >> curlun->blkbits;
 891                         curlun->info_valid = 1;
 892                         break;
 893                 }
 894
 895  empty_write:
 896                 /* Did the host decide to stop early? */
 897                 if (bh->outreq->actual < bh->bulk_out_intended_length) {
 898                         common->short_packet_received = 1;
 899                         break;
 900                 }
 901         }
 902
 903         return -EIO;            /* No default reply */
 904 }
 905
 906
 907 /*-------------------------------------------------------------------------*/
 908
 909 static int do_synchronize_cache(struct fsg_common *common)
 910 {
 911         struct fsg_lun  *curlun = common->curlun;
 912         int             rc;
 913
 914         /* We ignore the requested LBA and write out all file's
 915          * dirty data buffers. */
 916         rc = fsg_lun_fsync_sub(curlun);
 917         if (rc)
 918                 curlun->sense_data = SS_WRITE_ERROR;
 919         return 0;
 920 }
 921
 922
 923 /*-------------------------------------------------------------------------*/
 924
 925 static void invalidate_sub(struct fsg_lun *curlun)
 926 {
 927         struct file     *filp = curlun->filp;
 928         struct inode    *inode = file_inode(filp);
 929         unsigned long   rc;
 930
 931         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
 932         VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
 933 }
 934
 935 static int do_verify(struct fsg_common *common)
 936 {
 937         struct fsg_lun          *curlun = common->curlun;
 938         u32                     lba;
 939         u32                     verification_length;
 940         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
 941         loff_t                  file_offset, file_offset_tmp;
 942         u32                     amount_left;
 943         unsigned int            amount;
 944         ssize_t                 nread;
 945
 946         /*
 947          * Get the starting Logical Block Address and check that it's
 948          * not too big.
 949          */
 950         lba = get_unaligned_be32(&common->cmnd[2]);
 951         if (lba >= curlun->num_sectors) {
 952                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 953                 return -EINVAL;
 954         }
 955
 956         /*
 957          * We allow DPO (Disable Page Out = don't save data in the
 958          * cache) but we don't implement it.
 959          */
 960         if (common->cmnd[1] & ~0x10) {
 961                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
 962                 return -EINVAL;
 963         }
 964
 965         verification_length = get_unaligned_be16(&common->cmnd[7]);
 966         if (unlikely(verification_length == 0))
 967                 return -EIO;            /* No default reply */
 968
 969         /* Prepare to carry out the file verify */
 970         amount_left = verification_length << curlun->blkbits;
 971         file_offset = ((loff_t) lba) << curlun->blkbits;
 972
 973         /* Write out all the dirty buffers before invalidating them */
 974         fsg_lun_fsync_sub(curlun);
 975         if (signal_pending(current))
 976                 return -EINTR;
 977
 978         invalidate_sub(curlun);
 979         if (signal_pending(current))
 980                 return -EINTR;
 981
 982         /* Just try to read the requested blocks */
 983         while (amount_left > 0) {
 984                 /*
 985                  * Figure out how much we need to read:
 986                  * Try to read the remaining amount, but not more than
 987                  * the buffer size.
 988                  * And don't try to read past the end of the file.
 989                  */
 990                 amount = min(amount_left, FSG_BUFLEN);
 991                 amount = min((loff_t)amount,
 992                              curlun->file_length - file_offset);
 993                 if (amount == 0) {
 994                         curlun->sense_data =
 995                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 996                         curlun->sense_data_info =
 997                                 file_offset >> curlun->blkbits;
 998                         curlun->info_valid = 1;
 999                         break;
1000                 }
1001
1002                 /* Perform the read */
1003                 file_offset_tmp = file_offset;
1004                 nread = kernel_read(curlun->filp, bh->buf, amount,
1005                                 &file_offset_tmp);
1006                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1007                                 (unsigned long long) file_offset,
1008                                 (int) nread);
1009                 if (signal_pending(current))
1010                         return -EINTR;
1011
1012                 if (nread < 0) {
1013                         LDBG(curlun, "error in file verify: %d\n", (int)nread);
1014                         nread = 0;
1015                 } else if (nread < amount) {
1016                         LDBG(curlun, "partial file verify: %d/%u\n",
1017                              (int)nread, amount);
1018                         nread = round_down(nread, curlun->blksize);
1019                 }
1020                 if (nread == 0) {
1021                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1022                         curlun->sense_data_info =
1023                                 file_offset >> curlun->blkbits;
1024                         curlun->info_valid = 1;
1025                         break;
1026                 }
1027                 file_offset += nread;
1028                 amount_left -= nread;
1029         }
1030         return 0;
1031 }
1032
1033
1034 /*-------------------------------------------------------------------------*/
1035
1036 static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
1037 {
1038         struct fsg_lun *curlun = common->curlun;
1039         u8      *buf = (u8 *) bh->buf;
1040
1041         if (!curlun) {          /* Unsupported LUNs are okay */
1042                 common->bad_lun_okay = 1;
1043                 memset(buf, 0, 36);
1044                 buf[0] = TYPE_NO_LUN;   /* Unsupported, no device-type */
1045                 buf[4] = 31;            /* Additional length */
1046                 return 36;
1047         }
1048
1049         buf[0] = curlun->cdrom ? TYPE_ROM : TYPE_DISK;
1050         buf[1] = curlun->removable ? 0x80 : 0;
1051         buf[2] = 2;             /* ANSI SCSI level 2 */
1052         buf[3] = 2;             /* SCSI-2 INQUIRY data format */
1053         buf[4] = 31;            /* Additional length */
1054         buf[5] = 0;             /* No special options */
1055         buf[6] = 0;
1056         buf[7] = 0;
1057         if (curlun->inquiry_string[0])
1058                 memcpy(buf + 8, curlun->inquiry_string,
1059                        sizeof(curlun->inquiry_string));
1060         else
1061                 memcpy(buf + 8, common->inquiry_string,
1062                        sizeof(common->inquiry_string));
1063         return 36;
1064 }
1065
1066 static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1067 {
1068         struct fsg_lun  *curlun = common->curlun;
1069         u8              *buf = (u8 *) bh->buf;
1070         u32             sd, sdinfo;
1071         int             valid;
1072
1073         /*
1074          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1075          *
1076          * If a REQUEST SENSE command is received from an initiator
1077          * with a pending unit attention condition (before the target
1078          * generates the contingent allegiance condition), then the
1079          * target shall either:
1080          *   a) report any pending sense data and preserve the unit
1081          *      attention condition on the logical unit, or,
1082          *   b) report the unit attention condition, may discard any
1083          *      pending sense data, and clear the unit attention
1084          *      condition on the logical unit for that initiator.
1085          *
1086          * FSG normally uses option a); enable this code to use option b).
1087          */
1088 #if 0
1089         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1090                 curlun->sense_data = curlun->unit_attention_data;
1091                 curlun->unit_attention_data = SS_NO_SENSE;
1092         }
1093 #endif
1094
1095         if (!curlun) {          /* Unsupported LUNs are okay */
1096                 common->bad_lun_okay = 1;
1097                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1098                 sdinfo = 0;
1099                 valid = 0;
1100         } else {
1101                 sd = curlun->sense_data;
1102                 sdinfo = curlun->sense_data_info;
1103                 valid = curlun->info_valid << 7;
1104                 curlun->sense_data = SS_NO_SENSE;
1105                 curlun->sense_data_info = 0;
1106                 curlun->info_valid = 0;
1107         }
1108
1109         memset(buf, 0, 18);
1110         buf[0] = valid | 0x70;                  /* Valid, current error */
1111         buf[2] = SK(sd);
1112         put_unaligned_be32(sdinfo, &buf[3]);    /* Sense information */
1113         buf[7] = 18 - 8;                        /* Additional sense length */
1114         buf[12] = ASC(sd);
1115         buf[13] = ASCQ(sd);
1116         return 18;
1117 }
1118
1119 static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
1120 {
1121         struct fsg_lun  *curlun = common->curlun;
1122         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1123         int             pmi = common->cmnd[8];
1124         u8              *buf = (u8 *)bh->buf;
1125         u32             max_lba;
1126
1127         /* Check the PMI and LBA fields */
1128         if (pmi > 1 || (pmi == 0 && lba != 0)) {
1129                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1130                 return -EINVAL;
1131         }
1132
1133         if (curlun->num_sectors < 0x100000000ULL)
1134                 max_lba = curlun->num_sectors - 1;
1135         else
1136                 max_lba = 0xffffffff;
1137         put_unaligned_be32(max_lba, &buf[0]);           /* Max logical block */
1138         put_unaligned_be32(curlun->blksize, &buf[4]);   /* Block length */
1139         return 8;
1140 }
1141
1142 static int do_read_capacity_16(struct fsg_common *common, struct fsg_buffhd *bh)
1143 {
1144         struct fsg_lun  *curlun = common->curlun;
1145         u64             lba = get_unaligned_be64(&common->cmnd[2]);
1146         int             pmi = common->cmnd[14];
1147         u8              *buf = (u8 *)bh->buf;
1148
1149         /* Check the PMI and LBA fields */
1150         if (pmi > 1 || (pmi == 0 && lba != 0)) {
1151                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1152                 return -EINVAL;
1153         }
1154
1155         put_unaligned_be64(curlun->num_sectors - 1, &buf[0]);
1156                                                         /* Max logical block */
1157         put_unaligned_be32(curlun->blksize, &buf[8]);   /* Block length */
1158
1159         /* It is safe to keep other fields zeroed */
1160         memset(&buf[12], 0, 32 - 12);
1161         return 32;
1162 }
1163
1164 static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
1165 {
1166         struct fsg_lun  *curlun = common->curlun;
1167         int             msf = common->cmnd[1] & 0x02;
1168         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1169         u8              *buf = (u8 *)bh->buf;
1170
1171         if (common->cmnd[1] & ~0x02) {          /* Mask away MSF */
1172                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1173                 return -EINVAL;
1174         }
1175         if (lba >= curlun->num_sectors) {
1176                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1177                 return -EINVAL;
1178         }
1179
1180         memset(buf, 0, 8);
1181         buf[0] = 0x01;          /* 2048 bytes of user data, rest is EC */
1182         store_cdrom_address(&buf[4], msf, lba);
1183         return 8;
1184 }
1185
1186 static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
1187 {
1188         struct fsg_lun  *curlun = common->curlun;
1189         int             msf = common->cmnd[1] & 0x02;
1190         int             start_track = common->cmnd[6];
1191         u8              *buf = (u8 *)bh->buf;
1192
1193         if ((common->cmnd[1] & ~0x02) != 0 ||   /* Mask away MSF */
1194                         start_track > 1) {
1195                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1196                 return -EINVAL;
1197         }
1198
1199         memset(buf, 0, 20);
1200         buf[1] = (20-2);                /* TOC data length */
1201         buf[2] = 1;                     /* First track number */
1202         buf[3] = 1;                     /* Last track number */
1203         buf[5] = 0x16;                  /* Data track, copying allowed */
1204         buf[6] = 0x01;                  /* Only track is number 1 */
1205         store_cdrom_address(&buf[8], msf, 0);
1206
1207         buf[13] = 0x16;                 /* Lead-out track is data */
1208         buf[14] = 0xAA;                 /* Lead-out track number */
1209         store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1210         return 20;
1211 }
1212
1213 static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1214 {
1215         struct fsg_lun  *curlun = common->curlun;
1216         int             mscmnd = common->cmnd[0];
1217         u8              *buf = (u8 *) bh->buf;
1218         u8              *buf0 = buf;
1219         int             pc, page_code;
1220         int             changeable_values, all_pages;
1221         int             valid_page = 0;
1222         int             len, limit;
1223
1224         if ((common->cmnd[1] & ~0x08) != 0) {   /* Mask away DBD */
1225                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1226                 return -EINVAL;
1227         }
1228         pc = common->cmnd[2] >> 6;
1229         page_code = common->cmnd[2] & 0x3f;
1230         if (pc == 3) {
1231                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1232                 return -EINVAL;
1233         }
1234         changeable_values = (pc == 1);
1235         all_pages = (page_code == 0x3f);
1236
1237         /*
1238          * Write the mode parameter header.  Fixed values are: default
1239          * medium type, no cache control (DPOFUA), and no block descriptors.
1240          * The only variable value is the WriteProtect bit.  We will fill in
1241          * the mode data length later.
1242          */
1243         memset(buf, 0, 8);
1244         if (mscmnd == MODE_SENSE) {
1245                 buf[2] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1246                 buf += 4;
1247                 limit = 255;
1248         } else {                        /* MODE_SENSE_10 */
1249                 buf[3] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1250                 buf += 8;
1251                 limit = 65535;          /* Should really be FSG_BUFLEN */
1252         }
1253
1254         /* No block descriptors */
1255
1256         /*
1257          * The mode pages, in numerical order.  The only page we support
1258          * is the Caching page.
1259          */
1260         if (page_code == 0x08 || all_pages) {
1261                 valid_page = 1;
1262                 buf[0] = 0x08;          /* Page code */
1263                 buf[1] = 10;            /* Page length */
1264                 memset(buf+2, 0, 10);   /* None of the fields are changeable */
1265
1266                 if (!changeable_values) {
1267                         buf[2] = 0x04;  /* Write cache enable, */
1268                                         /* Read cache not disabled */
1269                                         /* No cache retention priorities */
1270                         put_unaligned_be16(0xffff, &buf[4]);
1271                                         /* Don't disable prefetch */
1272                                         /* Minimum prefetch = 0 */
1273                         put_unaligned_be16(0xffff, &buf[8]);
1274                                         /* Maximum prefetch */
1275                         put_unaligned_be16(0xffff, &buf[10]);
1276                                         /* Maximum prefetch ceiling */
1277                 }
1278                 buf += 12;
1279         }
1280
1281         /*
1282          * Check that a valid page was requested and the mode data length
1283          * isn't too long.
1284          */
1285         len = buf - buf0;
1286         if (!valid_page || len > limit) {
1287                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1288                 return -EINVAL;
1289         }
1290
1291         /*  Store the mode data length */
1292         if (mscmnd == MODE_SENSE)
1293                 buf0[0] = len - 1;
1294         else
1295                 put_unaligned_be16(len - 2, buf0);
1296         return len;
1297 }
1298
1299 static int do_start_stop(struct fsg_common *common)
1300 {
1301         struct fsg_lun  *curlun = common->curlun;
1302         int             loej, start;
1303
1304         if (!curlun) {
1305                 return -EINVAL;
1306         } else if (!curlun->removable) {
1307                 curlun->sense_data = SS_INVALID_COMMAND;
1308                 return -EINVAL;
1309         } else if ((common->cmnd[1] & ~0x01) != 0 || /* Mask away Immed */
1310                    (common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */
1311                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1312                 return -EINVAL;
1313         }
1314
1315         loej  = common->cmnd[4] & 0x02;
1316         start = common->cmnd[4] & 0x01;
1317
1318         /*
1319          * Our emulation doesn't support mounting; the medium is
1320          * available for use as soon as it is loaded.
1321          */
1322         if (start) {
1323                 if (!fsg_lun_is_open(curlun)) {
1324                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1325                         return -EINVAL;
1326                 }
1327                 return 0;
1328         }
1329
1330         /* Are we allowed to unload the media? */
1331         if (curlun->prevent_medium_removal) {
1332                 LDBG(curlun, "unload attempt prevented\n");
1333                 curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
1334                 return -EINVAL;
1335         }
1336
1337         if (!loej)
1338                 return 0;
1339
1340         up_read(&common->filesem);
1341         down_write(&common->filesem);
1342         fsg_lun_close(curlun);
1343         up_write(&common->filesem);
1344         down_read(&common->filesem);
1345
1346         return 0;
1347 }
1348
1349 static int do_prevent_allow(struct fsg_common *common)
1350 {
1351         struct fsg_lun  *curlun = common->curlun;
1352         int             prevent;
1353
1354         if (!common->curlun) {
1355                 return -EINVAL;
1356         } else if (!common->curlun->removable) {
1357                 common->curlun->sense_data = SS_INVALID_COMMAND;
1358                 return -EINVAL;
1359         }
1360
1361         prevent = common->cmnd[4] & 0x01;
1362         if ((common->cmnd[4] & ~0x01) != 0) {   /* Mask away Prevent */
1363                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1364                 return -EINVAL;
1365         }
1366
1367         if (curlun->prevent_medium_removal && !prevent)
1368                 fsg_lun_fsync_sub(curlun);
1369         curlun->prevent_medium_removal = prevent;
1370         return 0;
1371 }
1372
1373 static int do_read_format_capacities(struct fsg_common *common,
1374                         struct fsg_buffhd *bh)
1375 {
1376         struct fsg_lun  *curlun = common->curlun;
1377         u8              *buf = (u8 *) bh->buf;
1378
1379         buf[0] = buf[1] = buf[2] = 0;
1380         buf[3] = 8;     /* Only the Current/Maximum Capacity Descriptor */
1381         buf += 4;
1382
1383         put_unaligned_be32(curlun->num_sectors, &buf[0]);
1384                                                 /* Number of blocks */
1385         put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
1386         buf[4] = 0x02;                          /* Current capacity */
1387         return 12;
1388 }
1389
1390 static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
1391 {
1392         struct fsg_lun  *curlun = common->curlun;
1393
1394         /* We don't support MODE SELECT */
1395         if (curlun)
1396                 curlun->sense_data = SS_INVALID_COMMAND;
1397         return -EINVAL;
1398 }
1399
1400
1401 /*-------------------------------------------------------------------------*/
1402
1403 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1404 {
1405         int     rc;
1406
1407         rc = fsg_set_halt(fsg, fsg->bulk_in);
1408         if (rc == -EAGAIN)
1409                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1410         while (rc != 0) {
1411                 if (rc != -EAGAIN) {
1412                         WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1413                         rc = 0;
1414                         break;
1415                 }
1416
1417                 /* Wait for a short time and then try again */
1418                 if (msleep_interruptible(100) != 0)
1419                         return -EINTR;
1420                 rc = usb_ep_set_halt(fsg->bulk_in);
1421         }
1422         return rc;
1423 }
1424
1425 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1426 {
1427         int     rc;
1428
1429         DBG(fsg, "bulk-in set wedge\n");
1430         rc = usb_ep_set_wedge(fsg->bulk_in);
1431         if (rc == -EAGAIN)
1432                 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1433         while (rc != 0) {
1434                 if (rc != -EAGAIN) {
1435                         WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1436                         rc = 0;
1437                         break;
1438                 }
1439
1440                 /* Wait for a short time and then try again */
1441                 if (msleep_interruptible(100) != 0)
1442                         return -EINTR;
1443                 rc = usb_ep_set_wedge(fsg->bulk_in);
1444         }
1445         return rc;
1446 }
1447
1448 static int throw_away_data(struct fsg_common *common)
1449 {
1450         struct fsg_buffhd       *bh, *bh2;
1451         u32                     amount;
1452         int                     rc;
1453
1454         for (bh = common->next_buffhd_to_drain;
1455              bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
1456              bh = common->next_buffhd_to_drain) {
1457
1458                 /* Try to submit another request if we need one */
1459                 bh2 = common->next_buffhd_to_fill;
1460                 if (bh2->state == BUF_STATE_EMPTY &&
1461                                 common->usb_amount_left > 0) {
1462                         amount = min(common->usb_amount_left, FSG_BUFLEN);
1463
1464                         /*
1465                          * Except at the end of the transfer, amount will be
1466                          * equal to the buffer size, which is divisible by
1467                          * the bulk-out maxpacket size.
1468                          */
1469                         set_bulk_out_req_length(common, bh2, amount);
1470                         if (!start_out_transfer(common, bh2))
1471                                 /* Dunno what to do if common->fsg is NULL */
1472                                 return -EIO;
1473                         common->next_buffhd_to_fill = bh2->next;
1474                         common->usb_amount_left -= amount;
1475                         continue;
1476                 }
1477
1478                 /* Wait for the data to be received */
1479                 rc = sleep_thread(common, false, bh);
1480                 if (rc)
1481                         return rc;
1482
1483                 /* Throw away the data in a filled buffer */
1484                 bh->state = BUF_STATE_EMPTY;
1485                 common->next_buffhd_to_drain = bh->next;
1486
1487                 /* A short packet or an error ends everything */
1488                 if (bh->outreq->actual < bh->bulk_out_intended_length ||
1489                                 bh->outreq->status != 0) {
1490                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1491                         return -EINTR;
1492                 }
1493         }
1494         return 0;
1495 }
1496
1497 static int finish_reply(struct fsg_common *common)
1498 {
1499         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
1500         int                     rc = 0;
1501
1502         switch (common->data_dir) {
1503         case DATA_DIR_NONE:
1504                 break;                  /* Nothing to send */
1505
1506         /*
1507          * If we don't know whether the host wants to read or write,
1508          * this must be CB or CBI with an unknown command.  We mustn't
1509          * try to send or receive any data.  So stall both bulk pipes
1510          * if we can and wait for a reset.
1511          */
1512         case DATA_DIR_UNKNOWN:
1513                 if (!common->can_stall) {
1514                         /* Nothing */
1515                 } else if (fsg_is_set(common)) {
1516                         fsg_set_halt(common->fsg, common->fsg->bulk_out);
1517                         rc = halt_bulk_in_endpoint(common->fsg);
1518                 } else {
1519                         /* Don't know what to do if common->fsg is NULL */
1520                         rc = -EIO;
1521                 }
1522                 break;
1523
1524         /* All but the last buffer of data must have already been sent */
1525         case DATA_DIR_TO_HOST:
1526                 if (common->data_size == 0) {
1527                         /* Nothing to send */
1528
1529                 /* Don't know what to do if common->fsg is NULL */
1530                 } else if (!fsg_is_set(common)) {
1531                         rc = -EIO;
1532
1533                 /* If there's no residue, simply send the last buffer */
1534                 } else if (common->residue == 0) {
1535                         bh->inreq->zero = 0;
1536                         if (!start_in_transfer(common, bh))
1537                                 return -EIO;
1538                         common->next_buffhd_to_fill = bh->next;
1539
1540                 /*
1541                  * For Bulk-only, mark the end of the data with a short
1542                  * packet.  If we are allowed to stall, halt the bulk-in
1543                  * endpoint.  (Note: This violates the Bulk-Only Transport
1544                  * specification, which requires us to pad the data if we
1545                  * don't halt the endpoint.  Presumably nobody will mind.)
1546                  */
1547                 } else {
1548                         bh->inreq->zero = 1;
1549                         if (!start_in_transfer(common, bh))
1550                                 rc = -EIO;
1551                         common->next_buffhd_to_fill = bh->next;
1552                         if (common->can_stall)
1553                                 rc = halt_bulk_in_endpoint(common->fsg);
1554                 }
1555                 break;
1556
1557         /*
1558          * We have processed all we want from the data the host has sent.
1559          * There may still be outstanding bulk-out requests.
1560          */
1561         case DATA_DIR_FROM_HOST:
1562                 if (common->residue == 0) {
1563                         /* Nothing to receive */
1564
1565                 /* Did the host stop sending unexpectedly early? */
1566                 } else if (common->short_packet_received) {
1567                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1568                         rc = -EINTR;
1569
1570                 /*
1571                  * We haven't processed all the incoming data.  Even though
1572                  * we may be allowed to stall, doing so would cause a race.
1573                  * The controller may already have ACK'ed all the remaining
1574                  * bulk-out packets, in which case the host wouldn't see a
1575                  * STALL.  Not realizing the endpoint was halted, it wouldn't
1576                  * clear the halt -- leading to problems later on.
1577                  */
1578 #if 0
1579                 } else if (common->can_stall) {
1580                         if (fsg_is_set(common))
1581                                 fsg_set_halt(common->fsg,
1582                                              common->fsg->bulk_out);
1583                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1584                         rc = -EINTR;
1585 #endif
1586
1587                 /*
1588                  * We can't stall.  Read in the excess data and throw it
1589                  * all away.
1590                  */
1591                 } else {
1592                         rc = throw_away_data(common);
1593                 }
1594                 break;
1595         }
1596         return rc;
1597 }
1598
1599 static void send_status(struct fsg_common *common)
1600 {
1601         struct fsg_lun          *curlun = common->curlun;
1602         struct fsg_buffhd       *bh;
1603         struct bulk_cs_wrap     *csw;
1604         int                     rc;
1605         u8                      status = US_BULK_STAT_OK;
1606         u32                     sd, sdinfo = 0;
1607
1608         /* Wait for the next buffer to become available */
1609         bh = common->next_buffhd_to_fill;
1610         rc = sleep_thread(common, false, bh);
1611         if (rc)
1612                 return;
1613
1614         if (curlun) {
1615                 sd = curlun->sense_data;
1616                 sdinfo = curlun->sense_data_info;
1617         } else if (common->bad_lun_okay)
1618                 sd = SS_NO_SENSE;
1619         else
1620                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1621
1622         if (common->phase_error) {
1623                 DBG(common, "sending phase-error status\n");
1624                 status = US_BULK_STAT_PHASE;
1625                 sd = SS_INVALID_COMMAND;
1626         } else if (sd != SS_NO_SENSE) {
1627                 DBG(common, "sending command-failure status\n");
1628                 status = US_BULK_STAT_FAIL;
1629                 VDBG(common, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
1630                                 "  info x%x\n",
1631                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
1632         }
1633
1634         /* Store and send the Bulk-only CSW */
1635         csw = (void *)bh->buf;
1636
1637         csw->Signature = cpu_to_le32(US_BULK_CS_SIGN);
1638         csw->Tag = common->tag;
1639         csw->Residue = cpu_to_le32(common->residue);
1640         csw->Status = status;
1641
1642         bh->inreq->length = US_BULK_CS_WRAP_LEN;
1643         bh->inreq->zero = 0;
1644         if (!start_in_transfer(common, bh))
1645                 /* Don't know what to do if common->fsg is NULL */
1646                 return;
1647
1648         common->next_buffhd_to_fill = bh->next;
1649         return;
1650 }
1651
1652
1653 /*-------------------------------------------------------------------------*/
1654
1655 /*
1656  * Check whether the command is properly formed and whether its data size
1657  * and direction agree with the values we already have.
1658  */
1659 static int check_command(struct fsg_common *common, int cmnd_size,
1660                          enum data_direction data_dir, unsigned int mask,
1661                          int needs_medium, const char *name)
1662 {
1663         int                     i;
1664         unsigned int            lun = common->cmnd[1] >> 5;
1665         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
1666         char                    hdlen[20];
1667         struct fsg_lun          *curlun;
1668
1669         hdlen[0] = 0;
1670         if (common->data_dir != DATA_DIR_UNKNOWN)
1671                 sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
1672                         common->data_size);
1673         VDBG(common, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
1674              name, cmnd_size, dirletter[(int) data_dir],
1675              common->data_size_from_cmnd, common->cmnd_size, hdlen);
1676
1677         /*
1678          * We can't reply at all until we know the correct data direction
1679          * and size.
1680          */
1681         if (common->data_size_from_cmnd == 0)
1682                 data_dir = DATA_DIR_NONE;
1683         if (common->data_size < common->data_size_from_cmnd) {
1684                 /*
1685                  * Host data size < Device data size is a phase error.
1686                  * Carry out the command, but only transfer as much as
1687                  * we are allowed.
1688                  */
1689                 common->data_size_from_cmnd = common->data_size;
1690                 common->phase_error = 1;
1691         }
1692         common->residue = common->data_size;
1693         common->usb_amount_left = common->data_size;
1694
1695         /* Conflicting data directions is a phase error */
1696         if (common->data_dir != data_dir && common->data_size_from_cmnd > 0) {
1697                 common->phase_error = 1;
1698                 return -EINVAL;
1699         }
1700
1701         /* Verify the length of the command itself */
1702         if (cmnd_size != common->cmnd_size) {
1703
1704                 /*
1705                  * Special case workaround: There are plenty of buggy SCSI
1706                  * implementations. Many have issues with cbw->Length
1707                  * field passing a wrong command size. For those cases we
1708                  * always try to work around the problem by using the length
1709                  * sent by the host side provided it is at least as large
1710                  * as the correct command length.
1711                  * Examples of such cases would be MS-Windows, which issues
1712                  * REQUEST SENSE with cbw->Length == 12 where it should
1713                  * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
1714                  * REQUEST SENSE with cbw->Length == 10 where it should
1715                  * be 6 as well.
1716                  */
1717                 if (cmnd_size <= common->cmnd_size) {
1718                         DBG(common, "%s is buggy! Expected length %d "
1719                             "but we got %d\n", name,
1720                             cmnd_size, common->cmnd_size);
1721                         cmnd_size = common->cmnd_size;
1722                 } else {
1723                         common->phase_error = 1;
1724                         return -EINVAL;
1725                 }
1726         }
1727
1728         /* Check that the LUN values are consistent */
1729         if (common->lun != lun)
1730                 DBG(common, "using LUN %u from CBW, not LUN %u from CDB\n",
1731                     common->lun, lun);
1732
1733         /* Check the LUN */
1734         curlun = common->curlun;
1735         if (curlun) {
1736                 if (common->cmnd[0] != REQUEST_SENSE) {
1737                         curlun->sense_data = SS_NO_SENSE;
1738                         curlun->sense_data_info = 0;
1739                         curlun->info_valid = 0;
1740                 }
1741         } else {
1742                 common->bad_lun_okay = 0;
1743
1744                 /*
1745                  * INQUIRY and REQUEST SENSE commands are explicitly allowed
1746                  * to use unsupported LUNs; all others may not.
1747                  */
1748                 if (common->cmnd[0] != INQUIRY &&
1749                     common->cmnd[0] != REQUEST_SENSE) {
1750                         DBG(common, "unsupported LUN %u\n", common->lun);
1751                         return -EINVAL;
1752                 }
1753         }
1754
1755         /*
1756          * If a unit attention condition exists, only INQUIRY and
1757          * REQUEST SENSE commands are allowed; anything else must fail.
1758          */
1759         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
1760             common->cmnd[0] != INQUIRY &&
1761             common->cmnd[0] != REQUEST_SENSE) {
1762                 curlun->sense_data = curlun->unit_attention_data;
1763                 curlun->unit_attention_data = SS_NO_SENSE;
1764                 return -EINVAL;
1765         }
1766
1767         /* Check that only command bytes listed in the mask are non-zero */
1768         common->cmnd[1] &= 0x1f;                        /* Mask away the LUN */
1769         for (i = 1; i < cmnd_size; ++i) {
1770                 if (common->cmnd[i] && !(mask & (1 << i))) {
1771                         if (curlun)
1772                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1773                         return -EINVAL;
1774                 }
1775         }
1776
1777         /* If the medium isn't mounted and the command needs to access
1778          * it, return an error. */
1779         if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
1780                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1781                 return -EINVAL;
1782         }
1783
1784         return 0;
1785 }
1786
1787 /* wrapper of check_command for data size in blocks handling */
1788 static int check_command_size_in_blocks(struct fsg_common *common,
1789                 int cmnd_size, enum data_direction data_dir,
1790                 unsigned int mask, int needs_medium, const char *name)
1791 {
1792         if (common->curlun)
1793                 common->data_size_from_cmnd <<= common->curlun->blkbits;
1794         return check_command(common, cmnd_size, data_dir,
1795                         mask, needs_medium, name);
1796 }
1797
1798 static int do_scsi_command(struct fsg_common *common)
1799 {
1800         struct fsg_buffhd       *bh;
1801         int                     rc;
1802         int                     reply = -EINVAL;
1803         int                     i;
1804         static char             unknown[16];
1805
1806         dump_cdb(common);
1807
1808         /* Wait for the next buffer to become available for data or status */
1809         bh = common->next_buffhd_to_fill;
1810         common->next_buffhd_to_drain = bh;
1811         rc = sleep_thread(common, false, bh);
1812         if (rc)
1813                 return rc;
1814
1815         common->phase_error = 0;
1816         common->short_packet_received = 0;
1817
1818         down_read(&common->filesem);    /* We're using the backing file */
1819         switch (common->cmnd[0]) {
1820
1821         case INQUIRY:
1822                 common->data_size_from_cmnd = common->cmnd[4];
1823                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1824                                       (1<<4), 0,
1825                                       "INQUIRY");
1826                 if (reply == 0)
1827                         reply = do_inquiry(common, bh);
1828                 break;
1829
1830         case MODE_SELECT:
1831                 common->data_size_from_cmnd = common->cmnd[4];
1832                 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
1833                                       (1<<1) | (1<<4), 0,
1834                                       "MODE SELECT(6)");
1835                 if (reply == 0)
1836                         reply = do_mode_select(common, bh);
1837                 break;
1838
1839         case MODE_SELECT_10:
1840                 common->data_size_from_cmnd =
1841                         get_unaligned_be16(&common->cmnd[7]);
1842                 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
1843                                       (1<<1) | (3<<7), 0,
1844                                       "MODE SELECT(10)");
1845                 if (reply == 0)
1846                         reply = do_mode_select(common, bh);
1847                 break;
1848
1849         case MODE_SENSE:
1850                 common->data_size_from_cmnd = common->cmnd[4];
1851                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1852                                       (1<<1) | (1<<2) | (1<<4), 0,
1853                                       "MODE SENSE(6)");
1854                 if (reply == 0)
1855                         reply = do_mode_sense(common, bh);
1856                 break;
1857
1858         case MODE_SENSE_10:
1859                 common->data_size_from_cmnd =
1860                         get_unaligned_be16(&common->cmnd[7]);
1861                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1862                                       (1<<1) | (1<<2) | (3<<7), 0,
1863                                       "MODE SENSE(10)");
1864                 if (reply == 0)
1865                         reply = do_mode_sense(common, bh);
1866                 break;
1867
1868         case ALLOW_MEDIUM_REMOVAL:
1869                 common->data_size_from_cmnd = 0;
1870                 reply = check_command(common, 6, DATA_DIR_NONE,
1871                                       (1<<4), 0,
1872                                       "PREVENT-ALLOW MEDIUM REMOVAL");
1873                 if (reply == 0)
1874                         reply = do_prevent_allow(common);
1875                 break;
1876
1877         case READ_6:
1878                 i = common->cmnd[4];
1879                 common->data_size_from_cmnd = (i == 0) ? 256 : i;
1880                 reply = check_command_size_in_blocks(common, 6,
1881                                       DATA_DIR_TO_HOST,
1882                                       (7<<1) | (1<<4), 1,
1883                                       "READ(6)");
1884                 if (reply == 0)
1885                         reply = do_read(common);
1886                 break;
1887
1888         case READ_10:
1889                 common->data_size_from_cmnd =
1890                                 get_unaligned_be16(&common->cmnd[7]);
1891                 reply = check_command_size_in_blocks(common, 10,
1892                                       DATA_DIR_TO_HOST,
1893                                       (1<<1) | (0xf<<2) | (3<<7), 1,
1894                                       "READ(10)");
1895                 if (reply == 0)
1896                         reply = do_read(common);
1897                 break;
1898
1899         case READ_12:
1900                 common->data_size_from_cmnd =
1901                                 get_unaligned_be32(&common->cmnd[6]);
1902                 reply = check_command_size_in_blocks(common, 12,
1903                                       DATA_DIR_TO_HOST,
1904                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
1905                                       "READ(12)");
1906                 if (reply == 0)
1907                         reply = do_read(common);
1908                 break;
1909
1910         case READ_16:
1911                 common->data_size_from_cmnd =
1912                                 get_unaligned_be32(&common->cmnd[10]);
1913                 reply = check_command_size_in_blocks(common, 16,
1914                                       DATA_DIR_TO_HOST,
1915                                       (1<<1) | (0xff<<2) | (0xf<<10), 1,
1916                                       "READ(16)");
1917                 if (reply == 0)
1918                         reply = do_read(common);
1919                 break;
1920
1921         case READ_CAPACITY:
1922                 common->data_size_from_cmnd = 8;
1923                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1924                                       (0xf<<2) | (1<<8), 1,
1925                                       "READ CAPACITY");
1926                 if (reply == 0)
1927                         reply = do_read_capacity(common, bh);
1928                 break;
1929
1930         case READ_HEADER:
1931                 if (!common->curlun || !common->curlun->cdrom)
1932                         goto unknown_cmnd;
1933                 common->data_size_from_cmnd =
1934                         get_unaligned_be16(&common->cmnd[7]);
1935                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1936                                       (3<<7) | (0x1f<<1), 1,
1937                                       "READ HEADER");
1938                 if (reply == 0)
1939                         reply = do_read_header(common, bh);
1940                 break;
1941
1942         case READ_TOC:
1943                 if (!common->curlun || !common->curlun->cdrom)
1944                         goto unknown_cmnd;
1945                 common->data_size_from_cmnd =
1946                         get_unaligned_be16(&common->cmnd[7]);
1947                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1948                                       (7<<6) | (1<<1), 1,
1949                                       "READ TOC");
1950                 if (reply == 0)
1951                         reply = do_read_toc(common, bh);
1952                 break;
1953
1954         case READ_FORMAT_CAPACITIES:
1955                 common->data_size_from_cmnd =
1956                         get_unaligned_be16(&common->cmnd[7]);
1957                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1958                                       (3<<7), 1,
1959                                       "READ FORMAT CAPACITIES");
1960                 if (reply == 0)
1961                         reply = do_read_format_capacities(common, bh);
1962                 break;
1963
1964         case REQUEST_SENSE:
1965                 common->data_size_from_cmnd = common->cmnd[4];
1966                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1967                                       (1<<4), 0,
1968                                       "REQUEST SENSE");
1969                 if (reply == 0)
1970                         reply = do_request_sense(common, bh);
1971                 break;
1972
1973         case SERVICE_ACTION_IN_16:
1974                 switch (common->cmnd[1] & 0x1f) {
1975
1976                 case SAI_READ_CAPACITY_16:
1977                         common->data_size_from_cmnd =
1978                                 get_unaligned_be32(&common->cmnd[10]);
1979                         reply = check_command(common, 16, DATA_DIR_TO_HOST,
1980                                               (1<<1) | (0xff<<2) | (0xf<<10) |
1981                                               (1<<14), 1,
1982                                               "READ CAPACITY(16)");
1983                         if (reply == 0)
1984                                 reply = do_read_capacity_16(common, bh);
1985                         break;
1986
1987                 default:
1988                         goto unknown_cmnd;
1989                 }
1990                 break;
1991
1992         case START_STOP:
1993                 common->data_size_from_cmnd = 0;
1994                 reply = check_command(common, 6, DATA_DIR_NONE,
1995                                       (1<<1) | (1<<4), 0,
1996                                       "START-STOP UNIT");
1997                 if (reply == 0)
1998                         reply = do_start_stop(common);
1999                 break;
2000
2001         case SYNCHRONIZE_CACHE:
2002                 common->data_size_from_cmnd = 0;
2003                 reply = check_command(common, 10, DATA_DIR_NONE,
2004                                       (0xf<<2) | (3<<7), 1,
2005                                       "SYNCHRONIZE CACHE");
2006                 if (reply == 0)
2007                         reply = do_synchronize_cache(common);
2008                 break;
2009
2010         case TEST_UNIT_READY:
2011                 common->data_size_from_cmnd = 0;
2012                 reply = check_command(common, 6, DATA_DIR_NONE,
2013                                 0, 1,
2014                                 "TEST UNIT READY");
2015                 break;
2016
2017         /*
2018          * Although optional, this command is used by MS-Windows.  We
2019          * support a minimal version: BytChk must be 0.
2020          */
2021         case VERIFY:
2022                 common->data_size_from_cmnd = 0;
2023                 reply = check_command(common, 10, DATA_DIR_NONE,
2024                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2025                                       "VERIFY");
2026                 if (reply == 0)
2027                         reply = do_verify(common);
2028                 break;
2029
2030         case WRITE_6:
2031                 i = common->cmnd[4];
2032                 common->data_size_from_cmnd = (i == 0) ? 256 : i;
2033                 reply = check_command_size_in_blocks(common, 6,
2034                                       DATA_DIR_FROM_HOST,
2035                                       (7<<1) | (1<<4), 1,
2036                                       "WRITE(6)");
2037                 if (reply == 0)
2038                         reply = do_write(common);
2039                 break;
2040
2041         case WRITE_10:
2042                 common->data_size_from_cmnd =
2043                                 get_unaligned_be16(&common->cmnd[7]);
2044                 reply = check_command_size_in_blocks(common, 10,
2045                                       DATA_DIR_FROM_HOST,
2046                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2047                                       "WRITE(10)");
2048                 if (reply == 0)
2049                         reply = do_write(common);
2050                 break;
2051
2052         case WRITE_12:
2053                 common->data_size_from_cmnd =
2054                                 get_unaligned_be32(&common->cmnd[6]);
2055                 reply = check_command_size_in_blocks(common, 12,
2056                                       DATA_DIR_FROM_HOST,
2057                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
2058                                       "WRITE(12)");
2059                 if (reply == 0)
2060                         reply = do_write(common);
2061                 break;
2062
2063         case WRITE_16:
2064                 common->data_size_from_cmnd =
2065                                 get_unaligned_be32(&common->cmnd[10]);
2066                 reply = check_command_size_in_blocks(common, 16,
2067                                       DATA_DIR_FROM_HOST,
2068                                       (1<<1) | (0xff<<2) | (0xf<<10), 1,
2069                                       "WRITE(16)");
2070                 if (reply == 0)
2071                         reply = do_write(common);
2072                 break;
2073
2074         /*
2075          * Some mandatory commands that we recognize but don't implement.
2076          * They don't mean much in this setting.  It's left as an exercise
2077          * for anyone interested to implement RESERVE and RELEASE in terms
2078          * of Posix locks.
2079          */
2080         case FORMAT_UNIT:
2081         case RELEASE:
2082         case RESERVE:
2083         case SEND_DIAGNOSTIC:
2084
2085         default:
2086 unknown_cmnd:
2087                 common->data_size_from_cmnd = 0;
2088                 sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
2089                 reply = check_command(common, common->cmnd_size,
2090                                       DATA_DIR_UNKNOWN, ~0, 0, unknown);
2091                 if (reply == 0) {
2092                         common->curlun->sense_data = SS_INVALID_COMMAND;
2093                         reply = -EINVAL;
2094                 }
2095                 break;
2096         }
2097         up_read(&common->filesem);
2098
2099         if (reply == -EINTR || signal_pending(current))
2100                 return -EINTR;
2101
2102         /* Set up the single reply buffer for finish_reply() */
2103         if (reply == -EINVAL)
2104                 reply = 0;              /* Error reply length */
2105         if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
2106                 reply = min((u32)reply, common->data_size_from_cmnd);
2107                 bh->inreq->length = reply;
2108                 bh->state = BUF_STATE_FULL;
2109                 common->residue -= reply;
2110         }                               /* Otherwise it's already set */
2111
2112         return 0;
2113 }
2114
2115
2116 /*-------------------------------------------------------------------------*/
2117
2118 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2119 {
2120         struct usb_request      *req = bh->outreq;
2121         struct bulk_cb_wrap     *cbw = req->buf;
2122         struct fsg_common       *common = fsg->common;
2123
2124         /* Was this a real packet?  Should it be ignored? */
2125         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2126                 return -EINVAL;
2127
2128         /* Is the CBW valid? */
2129         if (req->actual != US_BULK_CB_WRAP_LEN ||
2130                         cbw->Signature != cpu_to_le32(
2131                                 US_BULK_CB_SIGN)) {
2132                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2133                                 req->actual,
2134                                 le32_to_cpu(cbw->Signature));
2135
2136                 /*
2137                  * The Bulk-only spec says we MUST stall the IN endpoint
2138                  * (6.6.1), so it's unavoidable.  It also says we must
2139                  * retain this state until the next reset, but there's
2140                  * no way to tell the controller driver it should ignore
2141                  * Clear-Feature(HALT) requests.
2142                  *
2143                  * We aren't required to halt the OUT endpoint; instead
2144                  * we can simply accept and discard any data received
2145                  * until the next reset.
2146                  */
2147                 wedge_bulk_in_endpoint(fsg);
2148                 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2149                 return -EINVAL;
2150         }
2151
2152         /* Is the CBW meaningful? */
2153         if (cbw->Lun >= ARRAY_SIZE(common->luns) ||
2154             cbw->Flags & ~US_BULK_FLAG_IN || cbw->Length <= 0 ||
2155             cbw->Length > MAX_COMMAND_SIZE) {
2156                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2157                                 "cmdlen %u\n",
2158                                 cbw->Lun, cbw->Flags, cbw->Length);
2159
2160                 /*
2161                  * We can do anything we want here, so let's stall the
2162                  * bulk pipes if we are allowed to.
2163                  */
2164                 if (common->can_stall) {
2165                         fsg_set_halt(fsg, fsg->bulk_out);
2166                         halt_bulk_in_endpoint(fsg);
2167                 }
2168                 return -EINVAL;
2169         }
2170
2171         /* Save the command for later */
2172         common->cmnd_size = cbw->Length;
2173         memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
2174         if (cbw->Flags & US_BULK_FLAG_IN)
2175                 common->data_dir = DATA_DIR_TO_HOST;
2176         else
2177                 common->data_dir = DATA_DIR_FROM_HOST;
2178         common->data_size = le32_to_cpu(cbw->DataTransferLength);
2179         if (common->data_size == 0)
2180                 common->data_dir = DATA_DIR_NONE;
2181         common->lun = cbw->Lun;
2182         if (common->lun < ARRAY_SIZE(common->luns))
2183                 common->curlun = common->luns[common->lun];
2184         else
2185                 common->curlun = NULL;
2186         common->tag = cbw->Tag;
2187         return 0;
2188 }
2189
2190 static int get_next_command(struct fsg_common *common)
2191 {
2192         struct fsg_buffhd       *bh;
2193         int                     rc = 0;
2194
2195         /* Wait for the next buffer to become available */
2196         bh = common->next_buffhd_to_fill;
2197         rc = sleep_thread(common, true, bh);
2198         if (rc)
2199                 return rc;
2200
2201         /* Queue a request to read a Bulk-only CBW */
2202         set_bulk_out_req_length(common, bh, US_BULK_CB_WRAP_LEN);
2203         if (!start_out_transfer(common, bh))
2204                 /* Don't know what to do if common->fsg is NULL */
2205                 return -EIO;
2206
2207         /*
2208          * We will drain the buffer in software, which means we
2209          * can reuse it for the next filling.  No need to advance
2210          * next_buffhd_to_fill.
2211          */
2212
2213         /* Wait for the CBW to arrive */
2214         rc = sleep_thread(common, true, bh);
2215         if (rc)
2216                 return rc;
2217
2218         rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
2219         bh->state = BUF_STATE_EMPTY;
2220
2221         return rc;
2222 }
2223
2224
2225 /*-------------------------------------------------------------------------*/
2226
2227 static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
2228                 struct usb_request **preq)
2229 {
2230         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2231         if (*preq)
2232                 return 0;
2233         ERROR(common, "can't allocate request for %s\n", ep->name);
2234         return -ENOMEM;
2235 }
2236
2237 /* Reset interface setting and re-init endpoint state (toggle etc). */
2238 static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
2239 {
2240         struct fsg_dev *fsg;
2241         int i, rc = 0;
2242
2243         if (common->running)
2244                 DBG(common, "reset interface\n");
2245
2246 reset:
2247         /* Deallocate the requests */
2248         if (common->fsg) {
2249                 fsg = common->fsg;
2250
2251                 for (i = 0; i < common->fsg_num_buffers; ++i) {
2252                         struct fsg_buffhd *bh = &common->buffhds[i];
2253
2254                         if (bh->inreq) {
2255                                 usb_ep_free_request(fsg->bulk_in, bh->inreq);
2256                                 bh->inreq = NULL;
2257                         }
2258                         if (bh->outreq) {
2259                                 usb_ep_free_request(fsg->bulk_out, bh->outreq);
2260                                 bh->outreq = NULL;
2261                         }
2262                 }
2263
2264                 /* Disable the endpoints */
2265                 if (fsg->bulk_in_enabled) {
2266                         usb_ep_disable(fsg->bulk_in);
2267                         fsg->bulk_in_enabled = 0;
2268                 }
2269                 if (fsg->bulk_out_enabled) {
2270                         usb_ep_disable(fsg->bulk_out);
2271                         fsg->bulk_out_enabled = 0;
2272                 }
2273
2274                 common->fsg = NULL;
2275                 wake_up(&common->fsg_wait);
2276         }
2277
2278         common->running = 0;
2279         if (!new_fsg || rc)
2280                 return rc;
2281
2282         common->fsg = new_fsg;
2283         fsg = common->fsg;
2284
2285         /* Enable the endpoints */
2286         rc = config_ep_by_speed(common->gadget, &(fsg->function), fsg->bulk_in);
2287         if (rc)
2288                 goto reset;
2289         rc = usb_ep_enable(fsg->bulk_in);
2290         if (rc)
2291                 goto reset;
2292         fsg->bulk_in->driver_data = common;
2293         fsg->bulk_in_enabled = 1;
2294
2295         rc = config_ep_by_speed(common->gadget, &(fsg->function),
2296                                 fsg->bulk_out);
2297         if (rc)
2298                 goto reset;
2299         rc = usb_ep_enable(fsg->bulk_out);
2300         if (rc)
2301                 goto reset;
2302         fsg->bulk_out->driver_data = common;
2303         fsg->bulk_out_enabled = 1;
2304         common->bulk_out_maxpacket = usb_endpoint_maxp(fsg->bulk_out->desc);
2305         clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2306
2307         /* Allocate the requests */
2308         for (i = 0; i < common->fsg_num_buffers; ++i) {
2309                 struct fsg_buffhd       *bh = &common->buffhds[i];
2310
2311                 rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
2312                 if (rc)
2313                         goto reset;
2314                 rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
2315                 if (rc)
2316                         goto reset;
2317                 bh->inreq->buf = bh->outreq->buf = bh->buf;
2318                 bh->inreq->context = bh->outreq->context = bh;
2319                 bh->inreq->complete = bulk_in_complete;
2320                 bh->outreq->complete = bulk_out_complete;
2321         }
2322
2323         common->running = 1;
2324         for (i = 0; i < ARRAY_SIZE(common->luns); ++i)
2325                 if (common->luns[i])
2326                         common->luns[i]->unit_attention_data =
2327                                 SS_RESET_OCCURRED;
2328         return rc;
2329 }
2330
2331
2332 /****************************** ALT CONFIGS ******************************/
2333
2334 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
2335 {
2336         struct fsg_dev *fsg = fsg_from_func(f);
2337
2338         __raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE, fsg);
2339         return USB_GADGET_DELAYED_STATUS;
2340 }
2341
2342 static void fsg_disable(struct usb_function *f)
2343 {
2344         struct fsg_dev *fsg = fsg_from_func(f);
2345
2346         /* Disable the endpoints */
2347         if (fsg->bulk_in_enabled) {
2348                 usb_ep_disable(fsg->bulk_in);
2349                 fsg->bulk_in_enabled = 0;
2350         }
2351         if (fsg->bulk_out_enabled) {
2352                 usb_ep_disable(fsg->bulk_out);
2353                 fsg->bulk_out_enabled = 0;
2354         }
2355
2356         __raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE, NULL);
2357 }
2358
2359
2360 /*-------------------------------------------------------------------------*/
2361
2362 static void handle_exception(struct fsg_common *common)
2363 {
2364         int                     i;
2365         struct fsg_buffhd       *bh;
2366         enum fsg_state          old_state;
2367         struct fsg_lun          *curlun;
2368         unsigned int            exception_req_tag;
2369         struct fsg_dev          *new_fsg;
2370
2371         /*
2372          * Clear the existing signals.  Anything but SIGUSR1 is converted
2373          * into a high-priority EXIT exception.
2374          */
2375         for (;;) {
2376                 int sig = kernel_dequeue_signal();
2377                 if (!sig)
2378                         break;
2379                 if (sig != SIGUSR1) {
2380                         spin_lock_irq(&common->lock);
2381                         if (common->state < FSG_STATE_EXIT)
2382                                 DBG(common, "Main thread exiting on signal\n");
2383                         common->state = FSG_STATE_EXIT;
2384                         spin_unlock_irq(&common->lock);
2385                 }
2386         }
2387
2388         /* Cancel all the pending transfers */
2389         if (likely(common->fsg)) {
2390                 for (i = 0; i < common->fsg_num_buffers; ++i) {
2391                         bh = &common->buffhds[i];
2392                         if (bh->state == BUF_STATE_SENDING)
2393                                 usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
2394                         if (bh->state == BUF_STATE_RECEIVING)
2395                                 usb_ep_dequeue(common->fsg->bulk_out,
2396                                                bh->outreq);
2397
2398                         /* Wait for a transfer to become idle */
2399                         if (sleep_thread(common, false, bh))
2400                                 return;
2401                 }
2402
2403                 /* Clear out the controller's fifos */
2404                 if (common->fsg->bulk_in_enabled)
2405                         usb_ep_fifo_flush(common->fsg->bulk_in);
2406                 if (common->fsg->bulk_out_enabled)
2407                         usb_ep_fifo_flush(common->fsg->bulk_out);
2408         }
2409
2410         /*
2411          * Reset the I/O buffer states and pointers, the SCSI
2412          * state, and the exception.  Then invoke the handler.
2413          */
2414         spin_lock_irq(&common->lock);
2415
2416         for (i = 0; i < common->fsg_num_buffers; ++i) {
2417                 bh = &common->buffhds[i];
2418                 bh->state = BUF_STATE_EMPTY;
2419         }
2420         common->next_buffhd_to_fill = &common->buffhds[0];
2421         common->next_buffhd_to_drain = &common->buffhds[0];
2422         exception_req_tag = common->exception_req_tag;
2423         new_fsg = common->exception_arg;
2424         old_state = common->state;
2425         common->state = FSG_STATE_NORMAL;
2426
2427         if (old_state != FSG_STATE_ABORT_BULK_OUT) {
2428                 for (i = 0; i < ARRAY_SIZE(common->luns); ++i) {
2429                         curlun = common->luns[i];
2430                         if (!curlun)
2431                                 continue;
2432                         curlun->prevent_medium_removal = 0;
2433                         curlun->sense_data = SS_NO_SENSE;
2434                         curlun->unit_attention_data = SS_NO_SENSE;
2435                         curlun->sense_data_info = 0;
2436                         curlun->info_valid = 0;
2437                 }
2438         }
2439         spin_unlock_irq(&common->lock);
2440
2441         /* Carry out any extra actions required for the exception */
2442         switch (old_state) {
2443         case FSG_STATE_NORMAL:
2444                 break;
2445
2446         case FSG_STATE_ABORT_BULK_OUT:
2447                 send_status(common);
2448                 break;
2449
2450         case FSG_STATE_PROTOCOL_RESET:
2451                 /*
2452                  * In case we were forced against our will to halt a
2453                  * bulk endpoint, clear the halt now.  (The SuperH UDC
2454                  * requires this.)
2455                  */
2456                 if (!fsg_is_set(common))
2457                         break;
2458                 if (test_and_clear_bit(IGNORE_BULK_OUT,
2459                                        &common->fsg->atomic_bitflags))
2460                         usb_ep_clear_halt(common->fsg->bulk_in);
2461
2462                 if (common->ep0_req_tag == exception_req_tag)
2463                         ep0_queue(common);      /* Complete the status stage */
2464
2465                 /*
2466                  * Technically this should go here, but it would only be
2467                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
2468                  * CONFIG_CHANGE cases.
2469                  */
2470                 /* for (i = 0; i < common->ARRAY_SIZE(common->luns); ++i) */
2471                 /*      if (common->luns[i]) */
2472                 /*              common->luns[i]->unit_attention_data = */
2473                 /*                      SS_RESET_OCCURRED;  */
2474                 break;
2475
2476         case FSG_STATE_CONFIG_CHANGE:
2477                 do_set_interface(common, new_fsg);
2478                 if (new_fsg)
2479                         usb_composite_setup_continue(common->cdev);
2480                 break;
2481
2482         case FSG_STATE_EXIT:
2483                 do_set_interface(common, NULL);         /* Free resources */
2484                 spin_lock_irq(&common->lock);
2485                 common->state = FSG_STATE_TERMINATED;   /* Stop the thread */
2486                 spin_unlock_irq(&common->lock);
2487                 break;
2488
2489         case FSG_STATE_TERMINATED:
2490                 break;
2491         }
2492 }
2493
2494
2495 /*-------------------------------------------------------------------------*/
2496
2497 static int fsg_main_thread(void *common_)
2498 {
2499         struct fsg_common       *common = common_;
2500         int                     i;
2501
2502         /*
2503          * Allow the thread to be killed by a signal, but set the signal mask
2504          * to block everything but INT, TERM, KILL, and USR1.
2505          */
2506         allow_signal(SIGINT);
2507         allow_signal(SIGTERM);
2508         allow_signal(SIGKILL);
2509         allow_signal(SIGUSR1);
2510
2511         /* Allow the thread to be frozen */
2512         set_freezable();
2513
2514         /* The main loop */
2515         while (common->state != FSG_STATE_TERMINATED) {
2516                 if (exception_in_progress(common) || signal_pending(current)) {
2517                         handle_exception(common);
2518                         continue;
2519                 }
2520
2521                 if (!common->running) {
2522                         sleep_thread(common, true, NULL);
2523                         continue;
2524                 }
2525
2526                 if (get_next_command(common) || exception_in_progress(common))
2527                         continue;
2528                 if (do_scsi_command(common) || exception_in_progress(common))
2529                         continue;
2530                 if (finish_reply(common) || exception_in_progress(common))
2531                         continue;
2532                 send_status(common);
2533         }
2534
2535         spin_lock_irq(&common->lock);
2536         common->thread_task = NULL;
2537         spin_unlock_irq(&common->lock);
2538
2539         /* Eject media from all LUNs */
2540
2541         down_write(&common->filesem);
2542         for (i = 0; i < ARRAY_SIZE(common->luns); i++) {
2543                 struct fsg_lun *curlun = common->luns[i];
2544
2545                 if (curlun && fsg_lun_is_open(curlun))
2546                         fsg_lun_close(curlun);
2547         }
2548         up_write(&common->filesem);
2549
2550         /* Let fsg_unbind() know the thread has exited */
2551         kthread_complete_and_exit(&common->thread_notifier, 0);
2552 }
2553
2554
2555 /*************************** DEVICE ATTRIBUTES ***************************/
2556
2557 static ssize_t ro_show(struct device *dev, struct device_attribute *attr, char *buf)
2558 {
2559         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2560
2561         return fsg_show_ro(curlun, buf);
2562 }
2563
2564 static ssize_t nofua_show(struct device *dev, struct device_attribute *attr,
2565                           char *buf)
2566 {
2567         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2568
2569         return fsg_show_nofua(curlun, buf);
2570 }
2571
2572 static ssize_t file_show(struct device *dev, struct device_attribute *attr,
2573                          char *buf)
2574 {
2575         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2576         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2577
2578         return fsg_show_file(curlun, filesem, buf);
2579 }
2580
2581 static ssize_t ro_store(struct device *dev, struct device_attribute *attr,
2582                         const char *buf, size_t count)
2583 {
2584         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2585         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2586
2587         return fsg_store_ro(curlun, filesem, buf, count);
2588 }
2589
2590 static ssize_t nofua_store(struct device *dev, struct device_attribute *attr,
2591                            const char *buf, size_t count)
2592 {
2593         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2594
2595         return fsg_store_nofua(curlun, buf, count);
2596 }
2597
2598 static ssize_t file_store(struct device *dev, struct device_attribute *attr,
2599                           const char *buf, size_t count)
2600 {
2601         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2602         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2603
2604         return fsg_store_file(curlun, filesem, buf, count);
2605 }
2606
2607 static DEVICE_ATTR_RW(nofua);
2608 /* mode wil be set in fsg_lun_attr_is_visible() */
2609 static DEVICE_ATTR(ro, 0, ro_show, ro_store);
2610 static DEVICE_ATTR(file, 0, file_show, file_store);
2611
2612 /****************************** FSG COMMON ******************************/
2613
2614 static void fsg_lun_release(struct device *dev)
2615 {
2616         /* Nothing needs to be done */
2617 }
2618
2619 static struct fsg_common *fsg_common_setup(struct fsg_common *common)
2620 {
2621         if (!common) {
2622                 common = kzalloc(sizeof(*common), GFP_KERNEL);
2623                 if (!common)
2624                         return ERR_PTR(-ENOMEM);
2625                 common->free_storage_on_release = 1;
2626         } else {
2627                 common->free_storage_on_release = 0;
2628         }
2629         init_rwsem(&common->filesem);
2630         spin_lock_init(&common->lock);
2631         init_completion(&common->thread_notifier);
2632         init_waitqueue_head(&common->io_wait);
2633         init_waitqueue_head(&common->fsg_wait);
2634         common->state = FSG_STATE_TERMINATED;
2635         memset(common->luns, 0, sizeof(common->luns));
2636
2637         return common;
2638 }
2639
2640 void fsg_common_set_sysfs(struct fsg_common *common, bool sysfs)
2641 {
2642         common->sysfs = sysfs;
2643 }
2644 EXPORT_SYMBOL_GPL(fsg_common_set_sysfs);
2645
2646 static void _fsg_common_free_buffers(struct fsg_buffhd *buffhds, unsigned n)
2647 {
2648         if (buffhds) {
2649                 struct fsg_buffhd *bh = buffhds;
2650                 while (n--) {
2651                         kfree(bh->buf);
2652                         ++bh;
2653                 }
2654                 kfree(buffhds);
2655         }
2656 }
2657
2658 int fsg_common_set_num_buffers(struct fsg_common *common, unsigned int n)
2659 {
2660         struct fsg_buffhd *bh, *buffhds;
2661         int i;
2662
2663         buffhds = kcalloc(n, sizeof(*buffhds), GFP_KERNEL);
2664         if (!buffhds)
2665                 return -ENOMEM;
2666
2667         /* Data buffers cyclic list */
2668         bh = buffhds;
2669         i = n;
2670         goto buffhds_first_it;
2671         do {
2672                 bh->next = bh + 1;
2673                 ++bh;
2674 buffhds_first_it:
2675                 bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
2676                 if (unlikely(!bh->buf))
2677                         goto error_release;
2678         } while (--i);
2679         bh->next = buffhds;
2680
2681         _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);
2682         common->fsg_num_buffers = n;
2683         common->buffhds = buffhds;
2684
2685         return 0;
2686
2687 error_release:
2688         /*
2689          * "buf"s pointed to by heads after n - i are NULL
2690          * so releasing them won't hurt
2691          */
2692         _fsg_common_free_buffers(buffhds, n);
2693
2694         return -ENOMEM;
2695 }
2696 EXPORT_SYMBOL_GPL(fsg_common_set_num_buffers);
2697
2698 void fsg_common_remove_lun(struct fsg_lun *lun)
2699 {
2700         if (device_is_registered(&lun->dev))
2701                 device_unregister(&lun->dev);
2702         fsg_lun_close(lun);
2703         kfree(lun);
2704 }
2705 EXPORT_SYMBOL_GPL(fsg_common_remove_lun);
2706
2707 static void _fsg_common_remove_luns(struct fsg_common *common, int n)
2708 {
2709         int i;
2710
2711         for (i = 0; i < n; ++i)
2712                 if (common->luns[i]) {
2713                         fsg_common_remove_lun(common->luns[i]);
2714                         common->luns[i] = NULL;
2715                 }
2716 }
2717
2718 void fsg_common_remove_luns(struct fsg_common *common)
2719 {
2720         _fsg_common_remove_luns(common, ARRAY_SIZE(common->luns));
2721 }
2722 EXPORT_SYMBOL_GPL(fsg_common_remove_luns);
2723
2724 void fsg_common_free_buffers(struct fsg_common *common)
2725 {
2726         _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);
2727         common->buffhds = NULL;
2728 }
2729 EXPORT_SYMBOL_GPL(fsg_common_free_buffers);
2730
2731 int fsg_common_set_cdev(struct fsg_common *common,
2732                          struct usb_composite_dev *cdev, bool can_stall)
2733 {
2734         struct usb_string *us;
2735
2736         common->gadget = cdev->gadget;
2737         common->ep0 = cdev->gadget->ep0;
2738         common->ep0req = cdev->req;
2739         common->cdev = cdev;
2740
2741         us = usb_gstrings_attach(cdev, fsg_strings_array,
2742                                  ARRAY_SIZE(fsg_strings));
2743         if (IS_ERR(us))
2744                 return PTR_ERR(us);
2745
2746         fsg_intf_desc.iInterface = us[FSG_STRING_INTERFACE].id;
2747
2748         /*
2749          * Some peripheral controllers are known not to be able to
2750          * halt bulk endpoints correctly.  If one of them is present,
2751          * disable stalls.
2752          */
2753         common->can_stall = can_stall &&
2754                         gadget_is_stall_supported(common->gadget);
2755
2756         return 0;
2757 }
2758 EXPORT_SYMBOL_GPL(fsg_common_set_cdev);
2759
2760 static struct attribute *fsg_lun_dev_attrs[] = {
2761         &dev_attr_ro.attr,
2762         &dev_attr_file.attr,
2763         &dev_attr_nofua.attr,
2764         NULL
2765 };
2766
2767 static umode_t fsg_lun_dev_is_visible(struct kobject *kobj,
2768                                       struct attribute *attr, int idx)
2769 {
2770         struct device *dev = kobj_to_dev(kobj);
2771         struct fsg_lun *lun = fsg_lun_from_dev(dev);
2772
2773         if (attr == &dev_attr_ro.attr)
2774                 return lun->cdrom ? S_IRUGO : (S_IWUSR | S_IRUGO);
2775         if (attr == &dev_attr_file.attr)
2776                 return lun->removable ? (S_IWUSR | S_IRUGO) : S_IRUGO;
2777         return attr->mode;
2778 }
2779
2780 static const struct attribute_group fsg_lun_dev_group = {
2781         .attrs = fsg_lun_dev_attrs,
2782         .is_visible = fsg_lun_dev_is_visible,
2783 };
2784
2785 static const struct attribute_group *fsg_lun_dev_groups[] = {
2786         &fsg_lun_dev_group,
2787         NULL
2788 };
2789
2790 int fsg_common_create_lun(struct fsg_common *common, struct fsg_lun_config *cfg,
2791                           unsigned int id, const char *name,
2792                           const char **name_pfx)
2793 {
2794         struct fsg_lun *lun;
2795         char *pathbuf, *p;
2796         int rc = -ENOMEM;
2797
2798         if (id >= ARRAY_SIZE(common->luns))
2799                 return -ENODEV;
2800
2801         if (common->luns[id])
2802                 return -EBUSY;
2803
2804         if (!cfg->filename && !cfg->removable) {
2805                 pr_err("no file given for LUN%d\n", id);
2806                 return -EINVAL;
2807         }
2808
2809         lun = kzalloc(sizeof(*lun), GFP_KERNEL);
2810         if (!lun)
2811                 return -ENOMEM;
2812
2813         lun->name_pfx = name_pfx;
2814
2815         lun->cdrom = !!cfg->cdrom;
2816         lun->ro = cfg->cdrom || cfg->ro;
2817         lun->initially_ro = lun->ro;
2818         lun->removable = !!cfg->removable;
2819
2820         if (!common->sysfs) {
2821                 /* we DON'T own the name!*/
2822                 lun->name = name;
2823         } else {
2824                 lun->dev.release = fsg_lun_release;
2825                 lun->dev.parent = &common->gadget->dev;
2826                 lun->dev.groups = fsg_lun_dev_groups;
2827                 dev_set_drvdata(&lun->dev, &common->filesem);
2828                 dev_set_name(&lun->dev, "%s", name);
2829                 lun->name = dev_name(&lun->dev);
2830
2831                 rc = device_register(&lun->dev);
2832                 if (rc) {
2833                         pr_info("failed to register LUN%d: %d\n", id, rc);
2834                         put_device(&lun->dev);
2835                         goto error_sysfs;
2836                 }
2837         }
2838
2839         common->luns[id] = lun;
2840
2841         if (cfg->filename) {
2842                 rc = fsg_lun_open(lun, cfg->filename);
2843                 if (rc)
2844                         goto error_lun;
2845         }
2846
2847         pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
2848         p = "(no medium)";
2849         if (fsg_lun_is_open(lun)) {
2850                 p = "(error)";
2851                 if (pathbuf) {
2852                         p = file_path(lun->filp, pathbuf, PATH_MAX);
2853                         if (IS_ERR(p))
2854                                 p = "(error)";
2855                 }
2856         }
2857         pr_info("LUN: %s%s%sfile: %s\n",
2858               lun->removable ? "removable " : "",
2859               lun->ro ? "read only " : "",
2860               lun->cdrom ? "CD-ROM " : "",
2861               p);
2862         kfree(pathbuf);
2863
2864         return 0;
2865
2866 error_lun:
2867         if (device_is_registered(&lun->dev))
2868                 device_unregister(&lun->dev);
2869         fsg_lun_close(lun);
2870         common->luns[id] = NULL;
2871 error_sysfs:
2872         kfree(lun);
2873         return rc;
2874 }
2875 EXPORT_SYMBOL_GPL(fsg_common_create_lun);
2876
2877 int fsg_common_create_luns(struct fsg_common *common, struct fsg_config *cfg)
2878 {
2879         char buf[8]; /* enough for 100000000 different numbers, decimal */
2880         int i, rc;
2881
2882         fsg_common_remove_luns(common);
2883
2884         for (i = 0; i < cfg->nluns; ++i) {
2885                 snprintf(buf, sizeof(buf), "lun%d", i);
2886                 rc = fsg_common_create_lun(common, &cfg->luns[i], i, buf, NULL);
2887                 if (rc)
2888                         goto fail;
2889         }
2890
2891         pr_info("Number of LUNs=%d\n", cfg->nluns);
2892
2893         return 0;
2894
2895 fail:
2896         _fsg_common_remove_luns(common, i);
2897         return rc;
2898 }
2899 EXPORT_SYMBOL_GPL(fsg_common_create_luns);
2900
2901 void fsg_common_set_inquiry_string(struct fsg_common *common, const char *vn,
2902                                    const char *pn)
2903 {
2904         int i;
2905
2906         /* Prepare inquiryString */
2907         i = get_default_bcdDevice();
2908         snprintf(common->inquiry_string, sizeof(common->inquiry_string),
2909                  "%-8s%-16s%04x", vn ?: "Linux",
2910                  /* Assume product name dependent on the first LUN */
2911                  pn ?: ((*common->luns)->cdrom
2912                      ? "File-CD Gadget"
2913                      : "File-Stor Gadget"),
2914                  i);
2915 }
2916 EXPORT_SYMBOL_GPL(fsg_common_set_inquiry_string);
2917
2918 static void fsg_common_release(struct fsg_common *common)
2919 {
2920         int i;
2921
2922         /* If the thread isn't already dead, tell it to exit now */
2923         if (common->state != FSG_STATE_TERMINATED) {
2924                 raise_exception(common, FSG_STATE_EXIT);
2925                 wait_for_completion(&common->thread_notifier);
2926         }
2927
2928         for (i = 0; i < ARRAY_SIZE(common->luns); ++i) {
2929                 struct fsg_lun *lun = common->luns[i];
2930                 if (!lun)
2931                         continue;
2932                 fsg_lun_close(lun);
2933                 if (device_is_registered(&lun->dev))
2934                         device_unregister(&lun->dev);
2935                 kfree(lun);
2936         }
2937
2938         _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);
2939         if (common->free_storage_on_release)
2940                 kfree(common);
2941 }
2942
2943
2944 /*-------------------------------------------------------------------------*/
2945
2946 static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
2947 {
2948         struct fsg_dev          *fsg = fsg_from_func(f);
2949         struct fsg_common       *common = fsg->common;
2950         struct usb_gadget       *gadget = c->cdev->gadget;
2951         int                     i;
2952         struct usb_ep           *ep;
2953         unsigned                max_burst;
2954         int                     ret;
2955         struct fsg_opts         *opts;
2956
2957         /* Don't allow to bind if we don't have at least one LUN */
2958         ret = _fsg_common_get_max_lun(common);
2959         if (ret < 0) {
2960                 pr_err("There should be at least one LUN.\n");
2961                 return -EINVAL;
2962         }
2963
2964         opts = fsg_opts_from_func_inst(f->fi);
2965         if (!opts->no_configfs) {
2966                 ret = fsg_common_set_cdev(fsg->common, c->cdev,
2967                                           fsg->common->can_stall);
2968                 if (ret)
2969                         return ret;
2970                 fsg_common_set_inquiry_string(fsg->common, NULL, NULL);
2971         }
2972
2973         if (!common->thread_task) {
2974                 common->state = FSG_STATE_NORMAL;
2975                 common->thread_task =
2976                         kthread_create(fsg_main_thread, common, "file-storage");
2977                 if (IS_ERR(common->thread_task)) {
2978                         ret = PTR_ERR(common->thread_task);
2979                         common->thread_task = NULL;
2980                         common->state = FSG_STATE_TERMINATED;
2981                         return ret;
2982                 }
2983                 DBG(common, "I/O thread pid: %d\n",
2984                     task_pid_nr(common->thread_task));
2985                 wake_up_process(common->thread_task);
2986         }
2987
2988         fsg->gadget = gadget;
2989
2990         /* New interface */
2991         i = usb_interface_id(c, f);
2992         if (i < 0)
2993                 goto fail;
2994         fsg_intf_desc.bInterfaceNumber = i;
2995         fsg->interface_number = i;
2996
2997         /* Find all the endpoints we will use */
2998         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
2999         if (!ep)
3000                 goto autoconf_fail;
3001         fsg->bulk_in = ep;
3002
3003         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
3004         if (!ep)
3005                 goto autoconf_fail;
3006         fsg->bulk_out = ep;
3007
3008         /* Assume endpoint addresses are the same for both speeds */
3009         fsg_hs_bulk_in_desc.bEndpointAddress =
3010                 fsg_fs_bulk_in_desc.bEndpointAddress;
3011         fsg_hs_bulk_out_desc.bEndpointAddress =
3012                 fsg_fs_bulk_out_desc.bEndpointAddress;
3013
3014         /* Calculate bMaxBurst, we know packet size is 1024 */
3015         max_burst = min_t(unsigned, FSG_BUFLEN / 1024, 15);
3016
3017         fsg_ss_bulk_in_desc.bEndpointAddress =
3018                 fsg_fs_bulk_in_desc.bEndpointAddress;
3019         fsg_ss_bulk_in_comp_desc.bMaxBurst = max_burst;
3020
3021         fsg_ss_bulk_out_desc.bEndpointAddress =
3022                 fsg_fs_bulk_out_desc.bEndpointAddress;
3023         fsg_ss_bulk_out_comp_desc.bMaxBurst = max_burst;
3024
3025         ret = usb_assign_descriptors(f, fsg_fs_function, fsg_hs_function,
3026                         fsg_ss_function, fsg_ss_function);
3027         if (ret)
3028                 goto autoconf_fail;
3029
3030         return 0;
3031
3032 autoconf_fail:
3033         ERROR(fsg, "unable to autoconfigure all endpoints\n");
3034         i = -ENOTSUPP;
3035 fail:
3036         /* terminate the thread */
3037         if (fsg->common->state != FSG_STATE_TERMINATED) {
3038                 raise_exception(fsg->common, FSG_STATE_EXIT);
3039                 wait_for_completion(&fsg->common->thread_notifier);
3040         }
3041         return i;
3042 }
3043
3044 /****************************** ALLOCATE FUNCTION *************************/
3045
3046 static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
3047 {
3048         struct fsg_dev          *fsg = fsg_from_func(f);
3049         struct fsg_common       *common = fsg->common;
3050
3051         DBG(fsg, "unbind\n");
3052         if (fsg->common->fsg == fsg) {
3053                 __raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE, NULL);
3054                 /* FIXME: make interruptible or killable somehow? */
3055                 wait_event(common->fsg_wait, common->fsg != fsg);
3056         }
3057
3058         usb_free_all_descriptors(&fsg->function);
3059 }
3060
3061 static inline struct fsg_lun_opts *to_fsg_lun_opts(struct config_item *item)
3062 {
3063         return container_of(to_config_group(item), struct fsg_lun_opts, group);
3064 }
3065
3066 static inline struct fsg_opts *to_fsg_opts(struct config_item *item)
3067 {
3068         return container_of(to_config_group(item), struct fsg_opts,
3069                             func_inst.group);
3070 }
3071
3072 static void fsg_lun_attr_release(struct config_item *item)
3073 {
3074         struct fsg_lun_opts *lun_opts;
3075
3076         lun_opts = to_fsg_lun_opts(item);
3077         kfree(lun_opts);
3078 }
3079
3080 static struct configfs_item_operations fsg_lun_item_ops = {
3081         .release                = fsg_lun_attr_release,
3082 };
3083
3084 static ssize_t fsg_lun_opts_file_show(struct config_item *item, char *page)
3085 {
3086         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3087         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3088
3089         return fsg_show_file(opts->lun, &fsg_opts->common->filesem, page);
3090 }
3091
3092 static ssize_t fsg_lun_opts_file_store(struct config_item *item,
3093                                        const char *page, size_t len)
3094 {
3095         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3096         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3097
3098         return fsg_store_file(opts->lun, &fsg_opts->common->filesem, page, len);
3099 }
3100
3101 CONFIGFS_ATTR(fsg_lun_opts_, file);
3102
3103 static ssize_t fsg_lun_opts_ro_show(struct config_item *item, char *page)
3104 {
3105         return fsg_show_ro(to_fsg_lun_opts(item)->lun, page);
3106 }
3107
3108 static ssize_t fsg_lun_opts_ro_store(struct config_item *item,
3109                                        const char *page, size_t len)
3110 {
3111         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3112         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3113
3114         return fsg_store_ro(opts->lun, &fsg_opts->common->filesem, page, len);
3115 }
3116
3117 CONFIGFS_ATTR(fsg_lun_opts_, ro);
3118
3119 static ssize_t fsg_lun_opts_removable_show(struct config_item *item,
3120                                            char *page)
3121 {
3122         return fsg_show_removable(to_fsg_lun_opts(item)->lun, page);
3123 }
3124
3125 static ssize_t fsg_lun_opts_removable_store(struct config_item *item,
3126                                        const char *page, size_t len)
3127 {
3128         return fsg_store_removable(to_fsg_lun_opts(item)->lun, page, len);
3129 }
3130
3131 CONFIGFS_ATTR(fsg_lun_opts_, removable);
3132
3133 static ssize_t fsg_lun_opts_cdrom_show(struct config_item *item, char *page)
3134 {
3135         return fsg_show_cdrom(to_fsg_lun_opts(item)->lun, page);
3136 }
3137
3138 static ssize_t fsg_lun_opts_cdrom_store(struct config_item *item,
3139                                        const char *page, size_t len)
3140 {
3141         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3142         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3143
3144         return fsg_store_cdrom(opts->lun, &fsg_opts->common->filesem, page,
3145                                len);
3146 }
3147
3148 CONFIGFS_ATTR(fsg_lun_opts_, cdrom);
3149
3150 static ssize_t fsg_lun_opts_nofua_show(struct config_item *item, char *page)
3151 {
3152         return fsg_show_nofua(to_fsg_lun_opts(item)->lun, page);
3153 }
3154
3155 static ssize_t fsg_lun_opts_nofua_store(struct config_item *item,
3156                                        const char *page, size_t len)
3157 {
3158         return fsg_store_nofua(to_fsg_lun_opts(item)->lun, page, len);
3159 }
3160
3161 CONFIGFS_ATTR(fsg_lun_opts_, nofua);
3162
3163 static ssize_t fsg_lun_opts_inquiry_string_show(struct config_item *item,
3164                                                 char *page)
3165 {
3166         return fsg_show_inquiry_string(to_fsg_lun_opts(item)->lun, page);
3167 }
3168
3169 static ssize_t fsg_lun_opts_inquiry_string_store(struct config_item *item,
3170                                                  const char *page, size_t len)
3171 {
3172         return fsg_store_inquiry_string(to_fsg_lun_opts(item)->lun, page, len);
3173 }
3174
3175 CONFIGFS_ATTR(fsg_lun_opts_, inquiry_string);
3176
3177 static struct configfs_attribute *fsg_lun_attrs[] = {
3178         &fsg_lun_opts_attr_file,
3179         &fsg_lun_opts_attr_ro,
3180         &fsg_lun_opts_attr_removable,
3181         &fsg_lun_opts_attr_cdrom,
3182         &fsg_lun_opts_attr_nofua,
3183         &fsg_lun_opts_attr_inquiry_string,
3184         NULL,
3185 };
3186
3187 static const struct config_item_type fsg_lun_type = {
3188         .ct_item_ops    = &fsg_lun_item_ops,
3189         .ct_attrs       = fsg_lun_attrs,
3190         .ct_owner       = THIS_MODULE,
3191 };
3192
3193 static struct config_group *fsg_lun_make(struct config_group *group,
3194                                          const char *name)
3195 {
3196         struct fsg_lun_opts *opts;
3197         struct fsg_opts *fsg_opts;
3198         struct fsg_lun_config config;
3199         char *num_str;
3200         u8 num;
3201         int ret;
3202
3203         num_str = strchr(name, '.');
3204         if (!num_str) {
3205                 pr_err("Unable to locate . in LUN.NUMBER\n");
3206                 return ERR_PTR(-EINVAL);
3207         }
3208         num_str++;
3209
3210         ret = kstrtou8(num_str, 0, &num);
3211         if (ret)
3212                 return ERR_PTR(ret);
3213
3214         fsg_opts = to_fsg_opts(&group->cg_item);
3215         if (num >= FSG_MAX_LUNS)
3216                 return ERR_PTR(-ERANGE);
3217         num = array_index_nospec(num, FSG_MAX_LUNS);
3218
3219         mutex_lock(&fsg_opts->lock);
3220         if (fsg_opts->refcnt || fsg_opts->common->luns[num]) {
3221                 ret = -EBUSY;
3222                 goto out;
3223         }
3224
3225         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3226         if (!opts) {
3227                 ret = -ENOMEM;
3228                 goto out;
3229         }
3230
3231         memset(&config, 0, sizeof(config));
3232         config.removable = true;
3233
3234         ret = fsg_common_create_lun(fsg_opts->common, &config, num, name,
3235                                     (const char **)&group->cg_item.ci_name);
3236         if (ret) {
3237                 kfree(opts);
3238                 goto out;
3239         }
3240         opts->lun = fsg_opts->common->luns[num];
3241         opts->lun_id = num;
3242         mutex_unlock(&fsg_opts->lock);
3243
3244         config_group_init_type_name(&opts->group, name, &fsg_lun_type);
3245
3246         return &opts->group;
3247 out:
3248         mutex_unlock(&fsg_opts->lock);
3249         return ERR_PTR(ret);
3250 }
3251
3252 static void fsg_lun_drop(struct config_group *group, struct config_item *item)
3253 {
3254         struct fsg_lun_opts *lun_opts;
3255         struct fsg_opts *fsg_opts;
3256
3257         lun_opts = to_fsg_lun_opts(item);
3258         fsg_opts = to_fsg_opts(&group->cg_item);
3259
3260         mutex_lock(&fsg_opts->lock);
3261         if (fsg_opts->refcnt) {
3262                 struct config_item *gadget;
3263
3264                 gadget = group->cg_item.ci_parent->ci_parent;
3265                 unregister_gadget_item(gadget);
3266         }
3267
3268         fsg_common_remove_lun(lun_opts->lun);
3269         fsg_opts->common->luns[lun_opts->lun_id] = NULL;
3270         lun_opts->lun_id = 0;
3271         mutex_unlock(&fsg_opts->lock);
3272
3273         config_item_put(item);
3274 }
3275
3276 static void fsg_attr_release(struct config_item *item)
3277 {
3278         struct fsg_opts *opts = to_fsg_opts(item);
3279
3280         usb_put_function_instance(&opts->func_inst);
3281 }
3282
3283 static struct configfs_item_operations fsg_item_ops = {
3284         .release                = fsg_attr_release,
3285 };
3286
3287 static ssize_t fsg_opts_stall_show(struct config_item *item, char *page)
3288 {
3289         struct fsg_opts *opts = to_fsg_opts(item);
3290         int result;
3291
3292         mutex_lock(&opts->lock);
3293         result = sprintf(page, "%d", opts->common->can_stall);
3294         mutex_unlock(&opts->lock);
3295
3296         return result;
3297 }
3298
3299 static ssize_t fsg_opts_stall_store(struct config_item *item, const char *page,
3300                                     size_t len)
3301 {
3302         struct fsg_opts *opts = to_fsg_opts(item);
3303         int ret;
3304         bool stall;
3305
3306         mutex_lock(&opts->lock);
3307
3308         if (opts->refcnt) {
3309                 mutex_unlock(&opts->lock);
3310                 return -EBUSY;
3311         }
3312
3313         ret = strtobool(page, &stall);
3314         if (!ret) {
3315                 opts->common->can_stall = stall;
3316                 ret = len;
3317         }
3318
3319         mutex_unlock(&opts->lock);
3320
3321         return ret;
3322 }
3323
3324 CONFIGFS_ATTR(fsg_opts_, stall);
3325
3326 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
3327 static ssize_t fsg_opts_num_buffers_show(struct config_item *item, char *page)
3328 {
3329         struct fsg_opts *opts = to_fsg_opts(item);
3330         int result;
3331
3332         mutex_lock(&opts->lock);
3333         result = sprintf(page, "%d", opts->common->fsg_num_buffers);
3334         mutex_unlock(&opts->lock);
3335
3336         return result;
3337 }
3338
3339 static ssize_t fsg_opts_num_buffers_store(struct config_item *item,
3340                                           const char *page, size_t len)
3341 {
3342         struct fsg_opts *opts = to_fsg_opts(item);
3343         int ret;
3344         u8 num;
3345
3346         mutex_lock(&opts->lock);
3347         if (opts->refcnt) {
3348                 ret = -EBUSY;
3349                 goto end;
3350         }
3351         ret = kstrtou8(page, 0, &num);
3352         if (ret)
3353                 goto end;
3354
3355         ret = fsg_common_set_num_buffers(opts->common, num);
3356         if (ret)
3357                 goto end;
3358         ret = len;
3359
3360 end:
3361         mutex_unlock(&opts->lock);
3362         return ret;
3363 }
3364
3365 CONFIGFS_ATTR(fsg_opts_, num_buffers);
3366 #endif
3367
3368 static struct configfs_attribute *fsg_attrs[] = {
3369         &fsg_opts_attr_stall,
3370 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
3371         &fsg_opts_attr_num_buffers,
3372 #endif
3373         NULL,
3374 };
3375
3376 static struct configfs_group_operations fsg_group_ops = {
3377         .make_group     = fsg_lun_make,
3378         .drop_item      = fsg_lun_drop,
3379 };
3380
3381 static const struct config_item_type fsg_func_type = {
3382         .ct_item_ops    = &fsg_item_ops,
3383         .ct_group_ops   = &fsg_group_ops,
3384         .ct_attrs       = fsg_attrs,
3385         .ct_owner       = THIS_MODULE,
3386 };
3387
3388 static void fsg_free_inst(struct usb_function_instance *fi)
3389 {
3390         struct fsg_opts *opts;
3391
3392         opts = fsg_opts_from_func_inst(fi);
3393         fsg_common_release(opts->common);
3394         kfree(opts);
3395 }
3396
3397 static struct usb_function_instance *fsg_alloc_inst(void)
3398 {
3399         struct fsg_opts *opts;
3400         struct fsg_lun_config config;
3401         int rc;
3402
3403         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3404         if (!opts)
3405                 return ERR_PTR(-ENOMEM);
3406         mutex_init(&opts->lock);
3407         opts->func_inst.free_func_inst = fsg_free_inst;
3408         opts->common = fsg_common_setup(opts->common);
3409         if (IS_ERR(opts->common)) {
3410                 rc = PTR_ERR(opts->common);
3411                 goto release_opts;
3412         }
3413
3414         rc = fsg_common_set_num_buffers(opts->common,
3415                                         CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS);
3416         if (rc)
3417                 goto release_common;
3418
3419         pr_info(FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
3420
3421         memset(&config, 0, sizeof(config));
3422         config.removable = true;
3423         rc = fsg_common_create_lun(opts->common, &config, 0, "lun.0",
3424                         (const char **)&opts->func_inst.group.cg_item.ci_name);
3425         if (rc)
3426                 goto release_buffers;
3427
3428         opts->lun0.lun = opts->common->luns[0];
3429         opts->lun0.lun_id = 0;
3430
3431         config_group_init_type_name(&opts->func_inst.group, "", &fsg_func_type);
3432
3433         config_group_init_type_name(&opts->lun0.group, "lun.0", &fsg_lun_type);
3434         configfs_add_default_group(&opts->lun0.group, &opts->func_inst.group);
3435
3436         return &opts->func_inst;
3437
3438 release_buffers:
3439         fsg_common_free_buffers(opts->common);
3440 release_common:
3441         kfree(opts->common);
3442 release_opts:
3443         kfree(opts);
3444         return ERR_PTR(rc);
3445 }
3446
3447 static void fsg_free(struct usb_function *f)
3448 {
3449         struct fsg_dev *fsg;
3450         struct fsg_opts *opts;
3451
3452         fsg = container_of(f, struct fsg_dev, function);
3453         opts = container_of(f->fi, struct fsg_opts, func_inst);
3454
3455         mutex_lock(&opts->lock);
3456         opts->refcnt--;
3457         mutex_unlock(&opts->lock);
3458
3459         kfree(fsg);
3460 }
3461
3462 static struct usb_function *fsg_alloc(struct usb_function_instance *fi)
3463 {
3464         struct fsg_opts *opts = fsg_opts_from_func_inst(fi);
3465         struct fsg_common *common = opts->common;
3466         struct fsg_dev *fsg;
3467
3468         fsg = kzalloc(sizeof(*fsg), GFP_KERNEL);
3469         if (unlikely(!fsg))
3470                 return ERR_PTR(-ENOMEM);
3471
3472         mutex_lock(&opts->lock);
3473         opts->refcnt++;
3474         mutex_unlock(&opts->lock);
3475
3476         fsg->function.name      = FSG_DRIVER_DESC;
3477         fsg->function.bind      = fsg_bind;
3478         fsg->function.unbind    = fsg_unbind;
3479         fsg->function.setup     = fsg_setup;
3480         fsg->function.set_alt   = fsg_set_alt;
3481         fsg->function.disable   = fsg_disable;
3482         fsg->function.free_func = fsg_free;
3483
3484         fsg->common               = common;
3485
3486         return &fsg->function;
3487 }
3488
3489 DECLARE_USB_FUNCTION_INIT(mass_storage, fsg_alloc_inst, fsg_alloc);
3490 MODULE_LICENSE("GPL");
3491 MODULE_AUTHOR("Michal Nazarewicz");
3492
3493 /************************* Module parameters *************************/
3494
3495
3496 void fsg_config_from_params(struct fsg_config *cfg,
3497                        const struct fsg_module_parameters *params,
3498                        unsigned int fsg_num_buffers)
3499 {
3500         struct fsg_lun_config *lun;
3501         unsigned i;
3502
3503         /* Configure LUNs */
3504         cfg->nluns =
3505                 min(params->luns ?: (params->file_count ?: 1u),
3506                     (unsigned)FSG_MAX_LUNS);
3507         for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) {
3508                 lun->ro = !!params->ro[i];
3509                 lun->cdrom = !!params->cdrom[i];
3510                 lun->removable = !!params->removable[i];
3511                 lun->filename =
3512                         params->file_count > i && params->file[i][0]
3513                         ? params->file[i]
3514                         : NULL;
3515         }
3516
3517         /* Let MSF use defaults */
3518         cfg->vendor_name = NULL;
3519         cfg->product_name = NULL;
3520
3521         cfg->ops = NULL;
3522         cfg->private_data = NULL;
3523
3524         /* Finalise */
3525         cfg->can_stall = params->stall;
3526         cfg->fsg_num_buffers = fsg_num_buffers;
3527 }
3528 EXPORT_SYMBOL_GPL(fsg_config_from_params);