drivers/usb/gadget/storage_common.c

   1 /*
   2  * storage_common.c -- Common definitions for mass storage functionality
   3  *
   4  * Copyright (C) 2003-2008 Alan Stern
   5  * Copyeight (C) 2009 Samsung Electronics
   6  * Author: Michal Nazarewicz (mina86@mina86.com)
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  */
  13
  14 /*
  15  * This file requires the following identifiers used in USB strings to
  16  * be defined (each of type pointer to char):
  17  *  - fsg_string_interface    -- name of the interface
  18  */
  19
  20 /*
  21  * When USB_GADGET_DEBUG_FILES is defined the module param num_buffers
  22  * sets the number of pipeline buffers (length of the fsg_buffhd array).
  23  * The valid range of num_buffers is: num >= 2 && num <= 4.
  24  */
  25
  26
  27 #include <linux/usb/storage.h>
  28 #include <scsi/scsi.h>
  29 #include <asm/unaligned.h>
  30
  31
  32 /*
  33  * Thanks to NetChip Technologies for donating this product ID.
  34  *
  35  * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
  36  * Instead:  allocate your own, using normal USB-IF procedures.
  37  */
  38 #define FSG_VENDOR_ID   0x0525  /* NetChip */
  39 #define FSG_PRODUCT_ID  0xa4a5  /* Linux-USB File-backed Storage Gadget */
  40
  41
  42 /*-------------------------------------------------------------------------*/
  43
  44
  45 #ifndef DEBUG
  46 #undef VERBOSE_DEBUG
  47 #undef DUMP_MSGS
  48 #endif /* !DEBUG */
  49
  50 #ifdef VERBOSE_DEBUG
  51 #define VLDBG   LDBG
  52 #else
  53 #define VLDBG(lun, fmt, args...) do { } while (0)
  54 #endif /* VERBOSE_DEBUG */
  55
  56 #define LDBG(lun, fmt, args...)   dev_dbg (&(lun)->dev, fmt, ## args)
  57 #define LERROR(lun, fmt, args...) dev_err (&(lun)->dev, fmt, ## args)
  58 #define LWARN(lun, fmt, args...)  dev_warn(&(lun)->dev, fmt, ## args)
  59 #define LINFO(lun, fmt, args...)  dev_info(&(lun)->dev, fmt, ## args)
  60
  61
  62 #ifdef DUMP_MSGS
  63
  64 #  define dump_msg(fsg, /* const char * */ label,                       \
  65                    /* const u8 * */ buf, /* unsigned */ length) do {    \
  66         if (length < 512) {                                             \
  67                 DBG(fsg, "%s, length %u:\n", label, length);            \
  68                 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,      \
  69                                16, 1, buf, length, 0);                  \
  70         }                                                               \
  71 } while (0)
  72
  73 #  define dump_cdb(fsg) do { } while (0)
  74
  75 #else
  76
  77 #  define dump_msg(fsg, /* const char * */ label, \
  78                    /* const u8 * */ buf, /* unsigned */ length) do { } while (0)
  79
  80 #  ifdef VERBOSE_DEBUG
  81
  82 #    define dump_cdb(fsg)                                               \
  83         print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE,      \
  84                        16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0)         \
  85
  86 #  else
  87
  88 #    define dump_cdb(fsg) do { } while (0)
  89
  90 #  endif /* VERBOSE_DEBUG */
  91
  92 #endif /* DUMP_MSGS */
  93
  94 /*-------------------------------------------------------------------------*/
  95
  96 /* Length of a SCSI Command Data Block */
  97 #define MAX_COMMAND_SIZE        16
  98
  99 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
 100 #define SS_NO_SENSE                             0
 101 #define SS_COMMUNICATION_FAILURE                0x040800
 102 #define SS_INVALID_COMMAND                      0x052000
 103 #define SS_INVALID_FIELD_IN_CDB                 0x052400
 104 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE   0x052100
 105 #define SS_LOGICAL_UNIT_NOT_SUPPORTED           0x052500
 106 #define SS_MEDIUM_NOT_PRESENT                   0x023a00
 107 #define SS_MEDIUM_REMOVAL_PREVENTED             0x055302
 108 #define SS_NOT_READY_TO_READY_TRANSITION        0x062800
 109 #define SS_RESET_OCCURRED                       0x062900
 110 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED      0x053900
 111 #define SS_UNRECOVERED_READ_ERROR               0x031100
 112 #define SS_WRITE_ERROR                          0x030c02
 113 #define SS_WRITE_PROTECTED                      0x072700
 114
 115 #define SK(x)           ((u8) ((x) >> 16))      /* Sense Key byte, etc. */
 116 #define ASC(x)          ((u8) ((x) >> 8))
 117 #define ASCQ(x)         ((u8) (x))
 118
 119
 120 /*-------------------------------------------------------------------------*/
 121
 122
 123 struct fsg_lun {
 124         struct file     *filp;
 125         loff_t          file_length;
 126         loff_t          num_sectors;
 127
 128         unsigned int    initially_ro:1;
 129         unsigned int    ro:1;
 130         unsigned int    removable:1;
 131         unsigned int    cdrom:1;
 132         unsigned int    prevent_medium_removal:1;
 133         unsigned int    registered:1;
 134         unsigned int    info_valid:1;
 135         unsigned int    nofua:1;
 136
 137         u32             sense_data;
 138         u32             sense_data_info;
 139         u32             unit_attention_data;
 140
 141         unsigned int    blkbits;        /* Bits of logical block size of bound block device */
 142         unsigned int    blksize;        /* logical block size of bound block device */
 143         struct device   dev;
 144 #ifdef CONFIG_MTK_ICUSB_SUPPORT
 145         char isICUSB;
 146 #endif
 147 };
 148
 149 static inline bool fsg_lun_is_open(struct fsg_lun *curlun)
 150 {
 151         return curlun->filp != NULL;
 152 }
 153
 154 static inline struct fsg_lun *fsg_lun_from_dev(struct device *dev)
 155 {
 156         return container_of(dev, struct fsg_lun, dev);
 157 }
 158
 159
 160 /* Big enough to hold our biggest descriptor */
 161 #define EP0_BUFSIZE     256
 162 #define DELAYED_STATUS  (EP0_BUFSIZE + 999)     /* An impossibly large value */
 163
 164 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
 165
 166 static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;
 167 module_param_named(num_buffers, fsg_num_buffers, uint, S_IRUGO);
 168 MODULE_PARM_DESC(num_buffers, "Number of pipeline buffers");
 169
 170 #else
 171
 172 /*
 173  * Number of buffers we will use.
 174  * 2 is usually enough for good buffering pipeline
 175  */
 176 #define fsg_num_buffers CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS
 177
 178 #endif /* CONFIG_USB_DEBUG */
 179
 180 /* check if fsg_num_buffers is within a valid range */
 181 static inline int fsg_num_buffers_validate(void)
 182 {
 183         if (fsg_num_buffers >= 2 && fsg_num_buffers <= 4)
 184                 return 0;
 185         pr_err("fsg_num_buffers %u is out of range (%d to %d)\n",
 186                fsg_num_buffers, 2 ,4);
 187         return -EINVAL;
 188 }
 189
 190 /* Default size of buffer length. */
 191 #define FSG_BUFLEN      ((u32)16384)
 192
 193 /* Maximal number of LUNs supported in mass storage function */
 194 #define FSG_MAX_LUNS    8
 195
 196 enum fsg_buffer_state {
 197         BUF_STATE_EMPTY = 0,
 198         BUF_STATE_FULL,
 199         BUF_STATE_BUSY
 200 };
 201
 202 struct fsg_buffhd {
 203         void                            *buf;
 204         enum fsg_buffer_state           state;
 205         struct fsg_buffhd               *next;
 206
 207         /*
 208          * The NetChip 2280 is faster, and handles some protocol faults
 209          * better, if we don't submit any short bulk-out read requests.
 210          * So we will record the intended request length here.
 211          */
 212         unsigned int                    bulk_out_intended_length;
 213
 214         struct usb_request              *inreq;
 215         int                             inreq_busy;
 216         struct usb_request              *outreq;
 217         int                             outreq_busy;
 218 };
 219
 220 enum fsg_state {
 221         /* This one isn't used anywhere */
 222         FSG_STATE_COMMAND_PHASE = -10,
 223         FSG_STATE_DATA_PHASE,
 224         FSG_STATE_STATUS_PHASE,
 225
 226         FSG_STATE_IDLE = 0,
 227         FSG_STATE_ABORT_BULK_OUT,
 228         FSG_STATE_RESET,
 229         FSG_STATE_INTERFACE_CHANGE,
 230         FSG_STATE_CONFIG_CHANGE,
 231         FSG_STATE_DISCONNECT,
 232         FSG_STATE_EXIT,
 233         FSG_STATE_TERMINATED
 234 };
 235
 236 enum data_direction {
 237         DATA_DIR_UNKNOWN = 0,
 238         DATA_DIR_FROM_HOST,
 239         DATA_DIR_TO_HOST,
 240         DATA_DIR_NONE
 241 };
 242
 243
 244 /*-------------------------------------------------------------------------*/
 245
 246
 247 static inline u32 get_unaligned_be24(u8 *buf)
 248 {
 249         return 0xffffff & (u32) get_unaligned_be32(buf - 1);
 250 }
 251
 252
 253 /*-------------------------------------------------------------------------*/
 254
 255
 256 enum {
 257         FSG_STRING_INTERFACE
 258 };
 259
 260
 261 #ifdef CONFIG_USBIF_COMPLIANCE
 262 static struct usb_otg_descriptor
 263 fsg_otg_desc = {
 264         .bLength =              sizeof fsg_otg_desc,
 265         .bDescriptorType =      USB_DT_OTG,
 266 /* OTG 2.0: */
 267         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
 268         .bcdOTG = cpu_to_le16(0x200),
 269 };
 270 #endif
 271
 272 /* There is only one interface. */
 273
 274 static struct usb_interface_descriptor
 275 fsg_intf_desc = {
 276         .bLength =              sizeof fsg_intf_desc,
 277         .bDescriptorType =      USB_DT_INTERFACE,
 278
 279         .bNumEndpoints =        2,              /* Adjusted during fsg_bind() */
 280         .bInterfaceClass =      USB_CLASS_MASS_STORAGE,
 281         .bInterfaceSubClass =   USB_SC_SCSI,    /* Adjusted during fsg_bind() */
 282         .bInterfaceProtocol =   USB_PR_BULK,    /* Adjusted during fsg_bind() */
 283         .iInterface =           FSG_STRING_INTERFACE,
 284 };
 285
 286 /*
 287  * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
 288  * interrupt-in.
 289  */
 290
 291 static struct usb_endpoint_descriptor
 292 fsg_fs_bulk_in_desc = {
 293         .bLength =              USB_DT_ENDPOINT_SIZE,
 294         .bDescriptorType =      USB_DT_ENDPOINT,
 295
 296         .bEndpointAddress =     USB_DIR_IN,
 297         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 298         /* wMaxPacketSize set by autoconfiguration */
 299 };
 300
 301 static struct usb_endpoint_descriptor
 302 fsg_fs_bulk_out_desc = {
 303         .bLength =              USB_DT_ENDPOINT_SIZE,
 304         .bDescriptorType =      USB_DT_ENDPOINT,
 305
 306         .bEndpointAddress =     USB_DIR_OUT,
 307         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 308         /* wMaxPacketSize set by autoconfiguration */
 309 };
 310
 311 static struct usb_descriptor_header *fsg_fs_function[] = {
 312 #ifdef CONFIG_USBIF_COMPLIANCE
 313         (struct usb_descriptor_header *) &fsg_otg_desc,
 314 #endif
 315         (struct usb_descriptor_header *) &fsg_intf_desc,
 316         (struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
 317         (struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
 318         NULL,
 319 };
 320
 321
 322 /*
 323  * USB 2.0 devices need to expose both high speed and full speed
 324  * descriptors, unless they only run at full speed.
 325  *
 326  * That means alternate endpoint descriptors (bigger packets)
 327  * and a "device qualifier" ... plus more construction options
 328  * for the configuration descriptor.
 329  */
 330 static struct usb_endpoint_descriptor
 331 fsg_hs_bulk_in_desc = {
 332         .bLength =              USB_DT_ENDPOINT_SIZE,
 333         .bDescriptorType =      USB_DT_ENDPOINT,
 334
 335         /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
 336         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 337         .wMaxPacketSize =       cpu_to_le16(512),
 338 };
 339
 340 static struct usb_endpoint_descriptor
 341 fsg_hs_bulk_out_desc = {
 342         .bLength =              USB_DT_ENDPOINT_SIZE,
 343         .bDescriptorType =      USB_DT_ENDPOINT,
 344
 345         /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
 346         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 347         .wMaxPacketSize =       cpu_to_le16(512),
 348         .bInterval =            1,      /* NAK every 1 uframe */
 349 };
 350
 351
 352 static struct usb_descriptor_header *fsg_hs_function[] = {
 353 #ifdef CONFIG_USBIF_COMPLIANCE
 354         (struct usb_descriptor_header *) &fsg_otg_desc,
 355 #endif
 356         (struct usb_descriptor_header *) &fsg_intf_desc,
 357         (struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
 358         (struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
 359         NULL,
 360 };
 361
 362 static struct usb_endpoint_descriptor
 363 fsg_ss_bulk_in_desc = {
 364         .bLength =              USB_DT_ENDPOINT_SIZE,
 365         .bDescriptorType =      USB_DT_ENDPOINT,
 366
 367         /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
 368         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 369         .wMaxPacketSize =       cpu_to_le16(1024),
 370 };
 371
 372 static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = {
 373         .bLength =              sizeof(fsg_ss_bulk_in_comp_desc),
 374         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 375
 376         /*.bMaxBurst =          DYNAMIC, */
 377 };
 378
 379 static struct usb_endpoint_descriptor
 380 fsg_ss_bulk_out_desc = {
 381         .bLength =              USB_DT_ENDPOINT_SIZE,
 382         .bDescriptorType =      USB_DT_ENDPOINT,
 383
 384         /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
 385         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 386         .wMaxPacketSize =       cpu_to_le16(1024),
 387 };
 388
 389 static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = {
 390         .bLength =              sizeof(fsg_ss_bulk_in_comp_desc),
 391         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 392
 393         /*.bMaxBurst =          DYNAMIC, */
 394 };
 395
 396 static struct usb_descriptor_header *fsg_ss_function[] = {
 397 #ifdef CONFIG_USBIF_COMPLIANCE
 398         (struct usb_descriptor_header *) &fsg_otg_desc,
 399 #endif
 400         (struct usb_descriptor_header *) &fsg_intf_desc,
 401         (struct usb_descriptor_header *) &fsg_ss_bulk_in_desc,
 402         (struct usb_descriptor_header *) &fsg_ss_bulk_in_comp_desc,
 403         (struct usb_descriptor_header *) &fsg_ss_bulk_out_desc,
 404         (struct usb_descriptor_header *) &fsg_ss_bulk_out_comp_desc,
 405         NULL,
 406 };
 407
 408 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
 409 static struct usb_string                fsg_strings[] = {
 410         {FSG_STRING_INTERFACE,          fsg_string_interface},
 411         {}
 412 };
 413
 414 static struct usb_gadget_strings        fsg_stringtab = {
 415         .language       = 0x0409,               /* en-us */
 416         .strings        = fsg_strings,
 417 };
 418
 419
 420  /*-------------------------------------------------------------------------*/
 421
 422 /*
 423  * If the next two routines are called while the gadget is registered,
 424  * the caller must own fsg->filesem for writing.
 425  */
 426
 427 static void fsg_lun_close(struct fsg_lun *curlun)
 428 {
 429         if (curlun->filp) {
 430                 LDBG(curlun, "close backing file\n");
 431                 fput(curlun->filp);
 432                 curlun->filp = NULL;
 433         }
 434 }
 435
 436
 437 static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
 438 {
 439         int                             ro;
 440         struct file                     *filp = NULL;
 441         int                             rc = -EINVAL;
 442         struct inode                    *inode = NULL;
 443         loff_t                          size;
 444         loff_t                          num_sectors;
 445         loff_t                          min_sectors;
 446         unsigned int                    blkbits;
 447         unsigned int                    blksize;
 448
 449 #ifdef CONFIG_MTK_ICUSB_SUPPORT
 450 #define ICUSB_STORAGE_LABEL     "/dev/block/vold/8:"
 451         if(strstr(filename, ICUSB_STORAGE_LABEL))
 452         {
 453                 printk(KERN_WARNING "filename : %s, set isICUSB to 0\n", filename);
 454                 curlun->isICUSB = 1;
 455         }
 456         else
 457         {
 458                 printk(KERN_WARNING "filename : %s, set isICUSB to 1\n", filename);
 459                 curlun->isICUSB = 0;
 460         }
 461 #endif
 462
 463         /* R/W if we can, R/O if we must */
 464         ro = curlun->initially_ro;
 465         if (!ro) {
 466                 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
 467                 if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
 468                         ro = 1;
 469         }
 470         if (ro)
 471                 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
 472         if (IS_ERR(filp)) {
 473                 LINFO(curlun, "unable to open backing file: %s\n", filename);
 474                 return PTR_ERR(filp);
 475         }
 476
 477         if (!(filp->f_mode & FMODE_WRITE))
 478                 ro = 1;
 479
 480         inode = file_inode(filp);
 481         if ((!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
 482                 LINFO(curlun, "invalid file type: %s\n", filename);
 483                 goto out;
 484         }
 485
 486         /*
 487          * If we can't read the file, it's no good.
 488          * If we can't write the file, use it read-only.
 489          */
 490         if (!(filp->f_op->read || filp->f_op->aio_read)) {
 491                 LINFO(curlun, "file not readable: %s\n", filename);
 492                 goto out;
 493         }
 494         if (!(filp->f_op->write || filp->f_op->aio_write))
 495                 ro = 1;
 496
 497         size = i_size_read(inode->i_mapping->host);
 498         if (size < 0) {
 499                 LINFO(curlun, "unable to find file size: %s\n", filename);
 500                 rc = (int) size;
 501                 goto out;
 502         }
 503
 504         if (curlun->cdrom) {
 505                 blksize = 2048;
 506                 blkbits = 11;
 507         } else if (inode->i_bdev) {
 508                 blksize = bdev_logical_block_size(inode->i_bdev);
 509                 blkbits = blksize_bits(blksize);
 510         } else {
 511                 blksize = 512;
 512                 blkbits = 9;
 513         }
 514
 515         num_sectors = size >> blkbits; /* File size in logic-block-size blocks */
 516         min_sectors = 1;
 517         if (curlun->cdrom) {
 518                 min_sectors = 300;      /* Smallest track is 300 frames */
 519                 if (num_sectors >= 256*60*75) {
 520                         num_sectors = 256*60*75 - 1;
 521                         LINFO(curlun, "file too big: %s\n", filename);
 522                         LINFO(curlun, "using only first %d blocks\n",
 523                                         (int) num_sectors);
 524                 }
 525         }
 526         if (num_sectors < min_sectors) {
 527                 LINFO(curlun, "file too small: %s\n", filename);
 528                 rc = -ETOOSMALL;
 529                 goto out;
 530         }
 531
 532         if (fsg_lun_is_open(curlun))
 533                 fsg_lun_close(curlun);
 534
 535         curlun->blksize = blksize;
 536         curlun->blkbits = blkbits;
 537         curlun->ro = ro;
 538         curlun->filp = filp;
 539         curlun->file_length = size;
 540         curlun->num_sectors = num_sectors;
 541         LDBG(curlun, "open backing file: %s\n", filename);
 542         return 0;
 543
 544 out:
 545         fput(filp);
 546         return rc;
 547 }
 548
 549
 550 /*-------------------------------------------------------------------------*/
 551
 552 /*
 553  * Sync the file data, don't bother with the metadata.
 554  * This code was copied from fs/buffer.c:sys_fdatasync().
 555  */
 556 static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
 557 {
 558         struct file     *filp = curlun->filp;
 559
 560         if (curlun->ro || !filp)
 561                 return 0;
 562         return vfs_fsync(filp, 1);
 563 }
 564
 565 static void store_cdrom_address(u8 *dest, int msf, u32 addr)
 566 {
 567         if (msf) {
 568                 /* Convert to Minutes-Seconds-Frames */
 569                 addr >>= 2;             /* Convert to 2048-byte frames */
 570                 addr += 2*75;           /* Lead-in occupies 2 seconds */
 571                 dest[3] = addr % 75;    /* Frames */
 572                 addr /= 75;
 573                 dest[2] = addr % 60;    /* Seconds */
 574                 addr /= 60;
 575                 dest[1] = addr;         /* Minutes */
 576                 dest[0] = 0;            /* Reserved */
 577         } else {
 578                 /* Absolute sector */
 579                 put_unaligned_be32(addr, dest);
 580         }
 581 }
 582
 583 /**
 584  * fsg_get_toc() - Builds a TOC with required format @format.
 585  * @curlun: The LUN for which the TOC has to be built
 586  * @msf: Min Sec Frame format or LBA format for address
 587  * @format: TOC format code
 588  * @buf: The buffer into which the TOC is built
 589  *
 590  * Builds a Table of Content which can be used as data for READ_TOC command.
 591  * The TOC simulates a single session, single track CD-ROM mode 1 disc.
 592  *
 593  * Returns number of bytes written to @buf, -EINVAL if format not supported.
 594  */
 595 static int fsg_get_toc(struct fsg_lun *curlun, int msf, int format, u8 *buf)
 596 {
 597         int i, len;
 598         switch (format) {
 599
 600         case 0:
 601                 /* Formatted TOC */
 602                 len = 4 + 2*8;                /* 4 byte header + 2 descriptors */
 603                 memset(buf, 0, len);
 604                 buf[1] = len - 2;        /* TOC Length excludes length field */
 605
 606                 buf[2] = 1;                /* First track number */
 607                 buf[3] = 1;                /* Last track number */
 608                 buf[5] = 0x16;                /* Data track, copying allowed */
 609                 buf[6] = 0x01;                /* Only track is number 1 */
 610                 store_cdrom_address(&buf[8], msf, 0);
 611
 612                 buf[13] = 0x16;                /* Lead-out track is data */
 613                 buf[14] = 0xAA;                /* Lead-out track number */
 614                 store_cdrom_address(&buf[16], msf, curlun->num_sectors);
 615                 break;
 616
 617         case 2:
 618                 /* Raw TOC */
 619                 len = 4 + 3*11;                /* 4 byte header + 3 descriptors */
 620                 memset(buf, 0, len);        /* Header + A0, A1 & A2 descriptors */
 621                 buf[1] = len - 2;        /* TOC Length excludes length field */
 622                 buf[2] = 1;                /* First complete session */
 623                 buf[3] = 1;                /* Last complete session */
 624
 625                 buf += 4;
 626                 /* fill in A0, A1 and A2 points */
 627                 for (i = 0; i < 3; i++) {
 628                         buf[0] = 1;        /* Session number */
 629                         buf[1] = 0x16;        /* Data track, copying allowed */
 630                         /* 2 - Track number 0 ->  TOC */
 631                         buf[3] = 0xA0 + i; /* A0, A1, A2 point */
 632                         /* 4, 5, 6 - Min, sec, frame is zero */
 633                         buf[8] = 1;        /* Pmin: last track number */
 634                         buf += 11;        /* go to next track descriptor */
 635                 }
 636                 buf -= 11;                /* go back to A2 descriptor */
 637
 638                 /* For A2, 7, 8, 9, 10 - zero, Pmin, Psec, Pframe of Lead out */
 639                 store_cdrom_address(&buf[7], msf, curlun->num_sectors);
 640                 break;
 641
 642         default:
 643                 /* Multi-session, PMA, ATIP, CD-TEXT not supported/required */
 644                 len = -EINVAL;
 645                 break;
 646         }
 647         return len;
 648 }
 649
 650 /*-------------------------------------------------------------------------*/
 651
 652
 653 static ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
 654                            char *buf)
 655 {
 656         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 657
 658         return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
 659                                   ? curlun->ro
 660                                   : curlun->initially_ro);
 661 }
 662
 663 static ssize_t fsg_show_nofua(struct device *dev, struct device_attribute *attr,
 664                               char *buf)
 665 {
 666         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 667
 668         return sprintf(buf, "%u\n", curlun->nofua);
 669 }
 670
 671 static ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
 672                              char *buf)
 673 {
 674         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 675         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
 676         char            *p;
 677         ssize_t         rc;
 678
 679         down_read(filesem);
 680         if (fsg_lun_is_open(curlun)) {  /* Get the complete pathname */
 681                 p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
 682                 if (IS_ERR(p))
 683                         rc = PTR_ERR(p);
 684                 else {
 685                         rc = strlen(p);
 686                         memmove(buf, p, rc);
 687                         buf[rc] = '\n';         /* Add a newline */
 688                         buf[++rc] = 0;
 689                 }
 690         } else {                                /* No file, return 0 bytes */
 691                 *buf = 0;
 692                 rc = 0;
 693         }
 694         up_read(filesem);
 695         return rc;
 696 }
 697
 698
 699 static ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
 700                             const char *buf, size_t count)
 701 {
 702         ssize_t         rc;
 703         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 704         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
 705         unsigned        ro;
 706
 707         rc = kstrtouint(buf, 2, &ro);
 708         if (rc)
 709                 return rc;
 710
 711         /*
 712          * Allow the write-enable status to change only while the
 713          * backing file is closed.
 714          */
 715         down_read(filesem);
 716         if (fsg_lun_is_open(curlun)) {
 717                 LDBG(curlun, "read-only status change prevented\n");
 718                 rc = -EBUSY;
 719         } else {
 720                 curlun->ro = ro;
 721                 curlun->initially_ro = ro;
 722                 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
 723                 rc = count;
 724         }
 725         up_read(filesem);
 726         return rc;
 727 }
 728
 729 static ssize_t fsg_store_nofua(struct device *dev,
 730                                struct device_attribute *attr,
 731                                const char *buf, size_t count)
 732 {
 733         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 734         unsigned        nofua;
 735         int             ret;
 736
 737         ret = kstrtouint(buf, 2, &nofua);
 738         if (ret)
 739                 return ret;
 740
 741         /* Sync data when switching from async mode to sync */
 742         if (!nofua && curlun->nofua)
 743                 fsg_lun_fsync_sub(curlun);
 744
 745         curlun->nofua = nofua;
 746
 747         return count;
 748 }
 749
 750 static ssize_t fsg_store_file(struct device *dev, struct device_attribute *attr,
 751                               const char *buf, size_t count)
 752 {
 753         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 754         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
 755         int             rc = 0;
 756
 757
 758 #if !defined(CONFIG_USB_G_ANDROID)
 759         /* disabled in android because we need to allow closing the backing file
 760          * if the media was removed
 761          */
 762         if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
 763                 LDBG(curlun, "eject attempt prevented\n");
 764                 return -EBUSY;                          /* "Door is locked" */
 765         }
 766 #endif
 767
 768         printk("fsg_store_file file=%s, count=%d, curlun->cdrom=%d\n", buf, (int)count, curlun->cdrom);
 769
 770         /*
 771          * WORKAROUND:VOLD would clean the file path after switching to bicr.
 772          * So when the lun is being a CD-ROM a.k.a. BICR. Dont clean the file path to empty.
 773          */
 774         if (curlun->cdrom == 1 && count == 1)
 775                 return count;
 776
 777         /* Remove a trailing newline */
 778         if (count > 0 && buf[count-1] == '\n')
 779                 ((char *) buf)[count-1] = 0;            /* Ugh! */
 780
 781         /* Load new medium */
 782         down_write(filesem);
 783         if (count > 0 && buf[0]) {
 784                 /* fsg_lun_open() will close existing file if any. */
 785                 rc = fsg_lun_open(curlun, buf);
 786                 if (rc == 0)
 787                         curlun->unit_attention_data =
 788                                         SS_NOT_READY_TO_READY_TRANSITION;
 789         } else if (fsg_lun_is_open(curlun)) {
 790                 fsg_lun_close(curlun);
 791                 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
 792         }
 793         up_write(filesem);
 794         return (rc < 0 ? rc : count);
 795 }