drivers/block/pktcdvd.c

   1 /*
   2  * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
   3  * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
   4  * Copyright (C) 2006 Thomas Maier <balagi@justmail.de>
   5  *
   6  * May be copied or modified under the terms of the GNU General Public
   7  * License.  See linux/COPYING for more information.
   8  *
   9  * Packet writing layer for ATAPI and SCSI CD-RW, DVD+RW, DVD-RW and
  10  * DVD-RAM devices.
  11  *
  12  * Theory of operation:
  13  *
  14  * At the lowest level, there is the standard driver for the CD/DVD device,
  15  * such as drivers/scsi/sr.c. This driver can handle read and write requests,
  16  * but it doesn't know anything about the special restrictions that apply to
  17  * packet writing. One restriction is that write requests must be aligned to
  18  * packet boundaries on the physical media, and the size of a write request
  19  * must be equal to the packet size. Another restriction is that a
  20  * GPCMD_FLUSH_CACHE command has to be issued to the drive before a read
  21  * command, if the previous command was a write.
  22  *
  23  * The purpose of the packet writing driver is to hide these restrictions from
  24  * higher layers, such as file systems, and present a block device that can be
  25  * randomly read and written using 2kB-sized blocks.
  26  *
  27  * The lowest layer in the packet writing driver is the packet I/O scheduler.
  28  * Its data is defined by the struct packet_iosched and includes two bio
  29  * queues with pending read and write requests. These queues are processed
  30  * by the pkt_iosched_process_queue() function. The write requests in this
  31  * queue are already properly aligned and sized. This layer is responsible for
  32  * issuing the flush cache commands and scheduling the I/O in a good order.
  33  *
  34  * The next layer transforms unaligned write requests to aligned writes. This
  35  * transformation requires reading missing pieces of data from the underlying
  36  * block device, assembling the pieces to full packets and queuing them to the
  37  * packet I/O scheduler.
  38  *
  39  * At the top layer there is a custom ->submit_bio function that forwards
  40  * read requests directly to the iosched queue and puts write requests in the
  41  * unaligned write queue. A kernel thread performs the necessary read
  42  * gathering to convert the unaligned writes to aligned writes and then feeds
  43  * them to the packet I/O scheduler.
  44  *
  45  *************************************************************************/
  46
  47 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  48
  49 #include <linux/pktcdvd.h>
  50 #include <linux/module.h>
  51 #include <linux/types.h>
  52 #include <linux/kernel.h>
  53 #include <linux/compat.h>
  54 #include <linux/kthread.h>
  55 #include <linux/errno.h>
  56 #include <linux/spinlock.h>
  57 #include <linux/file.h>
  58 #include <linux/proc_fs.h>
  59 #include <linux/seq_file.h>
  60 #include <linux/miscdevice.h>
  61 #include <linux/freezer.h>
  62 #include <linux/mutex.h>
  63 #include <linux/slab.h>
  64 #include <linux/backing-dev.h>
  65 #include <scsi/scsi_cmnd.h>
  66 #include <scsi/scsi_ioctl.h>
  67 #include <scsi/scsi.h>
  68 #include <linux/debugfs.h>
  69 #include <linux/device.h>
  70 #include <linux/nospec.h>
  71 #include <linux/uaccess.h>
  72
  73 #define DRIVER_NAME     "pktcdvd"
  74
  75 #define MAX_SPEED 0xffff
  76
  77 static DEFINE_MUTEX(pktcdvd_mutex);
  78 static struct pktcdvd_device *pkt_devs[MAX_WRITERS];
  79 static struct proc_dir_entry *pkt_proc;
  80 static int pktdev_major;
  81 static int write_congestion_on  = PKT_WRITE_CONGESTION_ON;
  82 static int write_congestion_off = PKT_WRITE_CONGESTION_OFF;
  83 static struct mutex ctl_mutex;  /* Serialize open/close/setup/teardown */
  84 static mempool_t psd_pool;
  85 static struct bio_set pkt_bio_set;
  86
  87 /* /sys/class/pktcdvd */
  88 static struct class     class_pktcdvd;
  89 static struct dentry    *pkt_debugfs_root = NULL; /* /sys/kernel/debug/pktcdvd */
  90
  91 /* forward declaration */
  92 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev);
  93 static int pkt_remove_dev(dev_t pkt_dev);
  94
  95 static sector_t get_zone(sector_t sector, struct pktcdvd_device *pd)
  96 {
  97         return (sector + pd->offset) & ~(sector_t)(pd->settings.size - 1);
  98 }
  99
 100 /**********************************************************
 101  * sysfs interface for pktcdvd
 102  * by (C) 2006  Thomas Maier <balagi@justmail.de>
 103
 104   /sys/class/pktcdvd/pktcdvd[0-7]/
 105                      stat/reset
 106                      stat/packets_started
 107                      stat/packets_finished
 108                      stat/kb_written
 109                      stat/kb_read
 110                      stat/kb_read_gather
 111                      write_queue/size
 112                      write_queue/congestion_off
 113                      write_queue/congestion_on
 114  **********************************************************/
 115
 116 static ssize_t packets_started_show(struct device *dev,
 117                                     struct device_attribute *attr, char *buf)
 118 {
 119         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 120
 121         return sysfs_emit(buf, "%lu\n", pd->stats.pkt_started);
 122 }
 123 static DEVICE_ATTR_RO(packets_started);
 124
 125 static ssize_t packets_finished_show(struct device *dev,
 126                                      struct device_attribute *attr, char *buf)
 127 {
 128         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 129
 130         return sysfs_emit(buf, "%lu\n", pd->stats.pkt_ended);
 131 }
 132 static DEVICE_ATTR_RO(packets_finished);
 133
 134 static ssize_t kb_written_show(struct device *dev,
 135                                struct device_attribute *attr, char *buf)
 136 {
 137         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 138
 139         return sysfs_emit(buf, "%lu\n", pd->stats.secs_w >> 1);
 140 }
 141 static DEVICE_ATTR_RO(kb_written);
 142
 143 static ssize_t kb_read_show(struct device *dev,
 144                             struct device_attribute *attr, char *buf)
 145 {
 146         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 147
 148         return sysfs_emit(buf, "%lu\n", pd->stats.secs_r >> 1);
 149 }
 150 static DEVICE_ATTR_RO(kb_read);
 151
 152 static ssize_t kb_read_gather_show(struct device *dev,
 153                                    struct device_attribute *attr, char *buf)
 154 {
 155         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 156
 157         return sysfs_emit(buf, "%lu\n", pd->stats.secs_rg >> 1);
 158 }
 159 static DEVICE_ATTR_RO(kb_read_gather);
 160
 161 static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
 162                            const char *buf, size_t len)
 163 {
 164         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 165
 166         if (len > 0) {
 167                 pd->stats.pkt_started = 0;
 168                 pd->stats.pkt_ended = 0;
 169                 pd->stats.secs_w = 0;
 170                 pd->stats.secs_rg = 0;
 171                 pd->stats.secs_r = 0;
 172         }
 173         return len;
 174 }
 175 static DEVICE_ATTR_WO(reset);
 176
 177 static struct attribute *pkt_stat_attrs[] = {
 178         &dev_attr_packets_finished.attr,
 179         &dev_attr_packets_started.attr,
 180         &dev_attr_kb_read.attr,
 181         &dev_attr_kb_written.attr,
 182         &dev_attr_kb_read_gather.attr,
 183         &dev_attr_reset.attr,
 184         NULL,
 185 };
 186
 187 static const struct attribute_group pkt_stat_group = {
 188         .name = "stat",
 189         .attrs = pkt_stat_attrs,
 190 };
 191
 192 static ssize_t size_show(struct device *dev,
 193                          struct device_attribute *attr, char *buf)
 194 {
 195         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 196         int n;
 197
 198         spin_lock(&pd->lock);
 199         n = sysfs_emit(buf, "%d\n", pd->bio_queue_size);
 200         spin_unlock(&pd->lock);
 201         return n;
 202 }
 203 static DEVICE_ATTR_RO(size);
 204
 205 static void init_write_congestion_marks(int* lo, int* hi)
 206 {
 207         if (*hi > 0) {
 208                 *hi = max(*hi, 500);
 209                 *hi = min(*hi, 1000000);
 210                 if (*lo <= 0)
 211                         *lo = *hi - 100;
 212                 else {
 213                         *lo = min(*lo, *hi - 100);
 214                         *lo = max(*lo, 100);
 215                 }
 216         } else {
 217                 *hi = -1;
 218                 *lo = -1;
 219         }
 220 }
 221
 222 static ssize_t congestion_off_show(struct device *dev,
 223                                    struct device_attribute *attr, char *buf)
 224 {
 225         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 226         int n;
 227
 228         spin_lock(&pd->lock);
 229         n = sysfs_emit(buf, "%d\n", pd->write_congestion_off);
 230         spin_unlock(&pd->lock);
 231         return n;
 232 }
 233
 234 static ssize_t congestion_off_store(struct device *dev,
 235                                     struct device_attribute *attr,
 236                                     const char *buf, size_t len)
 237 {
 238         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 239         int val, ret;
 240
 241         ret = kstrtoint(buf, 10, &val);
 242         if (ret)
 243                 return ret;
 244
 245         spin_lock(&pd->lock);
 246         pd->write_congestion_off = val;
 247         init_write_congestion_marks(&pd->write_congestion_off, &pd->write_congestion_on);
 248         spin_unlock(&pd->lock);
 249         return len;
 250 }
 251 static DEVICE_ATTR_RW(congestion_off);
 252
 253 static ssize_t congestion_on_show(struct device *dev,
 254                                   struct device_attribute *attr, char *buf)
 255 {
 256         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 257         int n;
 258
 259         spin_lock(&pd->lock);
 260         n = sysfs_emit(buf, "%d\n", pd->write_congestion_on);
 261         spin_unlock(&pd->lock);
 262         return n;
 263 }
 264
 265 static ssize_t congestion_on_store(struct device *dev,
 266                                    struct device_attribute *attr,
 267                                    const char *buf, size_t len)
 268 {
 269         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 270         int val, ret;
 271
 272         ret = kstrtoint(buf, 10, &val);
 273         if (ret)
 274                 return ret;
 275
 276         spin_lock(&pd->lock);
 277         pd->write_congestion_on = val;
 278         init_write_congestion_marks(&pd->write_congestion_off, &pd->write_congestion_on);
 279         spin_unlock(&pd->lock);
 280         return len;
 281 }
 282 static DEVICE_ATTR_RW(congestion_on);
 283
 284 static struct attribute *pkt_wq_attrs[] = {
 285         &dev_attr_congestion_on.attr,
 286         &dev_attr_congestion_off.attr,
 287         &dev_attr_size.attr,
 288         NULL,
 289 };
 290
 291 static const struct attribute_group pkt_wq_group = {
 292         .name = "write_queue",
 293         .attrs = pkt_wq_attrs,
 294 };
 295
 296 static const struct attribute_group *pkt_groups[] = {
 297         &pkt_stat_group,
 298         &pkt_wq_group,
 299         NULL,
 300 };
 301
 302 static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
 303 {
 304         if (class_is_registered(&class_pktcdvd)) {
 305                 pd->dev = device_create_with_groups(&class_pktcdvd, NULL,
 306                                                     MKDEV(0, 0), pd, pkt_groups,
 307                                                     "%s", pd->disk->disk_name);
 308                 if (IS_ERR(pd->dev))
 309                         pd->dev = NULL;
 310         }
 311 }
 312
 313 static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
 314 {
 315         if (class_is_registered(&class_pktcdvd))
 316                 device_unregister(pd->dev);
 317 }
 318
 319
 320 /********************************************************************
 321   /sys/class/pktcdvd/
 322                      add            map block device
 323                      remove         unmap packet dev
 324                      device_map     show mappings
 325  *******************************************************************/
 326
 327 static ssize_t device_map_show(const struct class *c, const struct class_attribute *attr,
 328                                char *data)
 329 {
 330         int n = 0;
 331         int idx;
 332         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
 333         for (idx = 0; idx < MAX_WRITERS; idx++) {
 334                 struct pktcdvd_device *pd = pkt_devs[idx];
 335                 if (!pd)
 336                         continue;
 337                 n += sysfs_emit_at(data, n, "%s %u:%u %u:%u\n",
 338                         pd->disk->disk_name,
 339                         MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
 340                         MAJOR(pd->bdev->bd_dev),
 341                         MINOR(pd->bdev->bd_dev));
 342         }
 343         mutex_unlock(&ctl_mutex);
 344         return n;
 345 }
 346 static CLASS_ATTR_RO(device_map);
 347
 348 static ssize_t add_store(const struct class *c, const struct class_attribute *attr,
 349                          const char *buf, size_t count)
 350 {
 351         unsigned int major, minor;
 352
 353         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 354                 /* pkt_setup_dev() expects caller to hold reference to self */
 355                 if (!try_module_get(THIS_MODULE))
 356                         return -ENODEV;
 357
 358                 pkt_setup_dev(MKDEV(major, minor), NULL);
 359
 360                 module_put(THIS_MODULE);
 361
 362                 return count;
 363         }
 364
 365         return -EINVAL;
 366 }
 367 static CLASS_ATTR_WO(add);
 368
 369 static ssize_t remove_store(const struct class *c, const struct class_attribute *attr,
 370                             const char *buf, size_t count)
 371 {
 372         unsigned int major, minor;
 373         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 374                 pkt_remove_dev(MKDEV(major, minor));
 375                 return count;
 376         }
 377         return -EINVAL;
 378 }
 379 static CLASS_ATTR_WO(remove);
 380
 381 static struct attribute *class_pktcdvd_attrs[] = {
 382         &class_attr_add.attr,
 383         &class_attr_remove.attr,
 384         &class_attr_device_map.attr,
 385         NULL,
 386 };
 387 ATTRIBUTE_GROUPS(class_pktcdvd);
 388
 389 static struct class class_pktcdvd = {
 390         .name           = DRIVER_NAME,
 391         .class_groups   = class_pktcdvd_groups,
 392 };
 393
 394 static int pkt_sysfs_init(void)
 395 {
 396         /*
 397          * create control files in sysfs
 398          * /sys/class/pktcdvd/...
 399          */
 400         return class_register(&class_pktcdvd);
 401 }
 402
 403 static void pkt_sysfs_cleanup(void)
 404 {
 405         class_unregister(&class_pktcdvd);
 406 }
 407
 408 /********************************************************************
 409   entries in debugfs
 410
 411   /sys/kernel/debug/pktcdvd[0-7]/
 412                         info
 413
 414  *******************************************************************/
 415
 416 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
 417 {
 418         struct packet_data *pkt;
 419         int i;
 420
 421         for (i = 0; i < PACKET_NUM_STATES; i++)
 422                 states[i] = 0;
 423
 424         spin_lock(&pd->cdrw.active_list_lock);
 425         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
 426                 states[pkt->state]++;
 427         }
 428         spin_unlock(&pd->cdrw.active_list_lock);
 429 }
 430
 431 static int pkt_seq_show(struct seq_file *m, void *p)
 432 {
 433         struct pktcdvd_device *pd = m->private;
 434         char *msg;
 435         int states[PACKET_NUM_STATES];
 436
 437         seq_printf(m, "Writer %s mapped to %pg:\n", pd->disk->disk_name, pd->bdev);
 438
 439         seq_printf(m, "\nSettings:\n");
 440         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
 441
 442         if (pd->settings.write_type == 0)
 443                 msg = "Packet";
 444         else
 445                 msg = "Unknown";
 446         seq_printf(m, "\twrite type:\t\t%s\n", msg);
 447
 448         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
 449         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
 450
 451         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
 452
 453         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
 454                 msg = "Mode 1";
 455         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
 456                 msg = "Mode 2";
 457         else
 458                 msg = "Unknown";
 459         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
 460
 461         seq_printf(m, "\nStatistics:\n");
 462         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
 463         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
 464         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
 465         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
 466         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
 467
 468         seq_printf(m, "\nMisc:\n");
 469         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
 470         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
 471         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
 472         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
 473         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
 474         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
 475
 476         seq_printf(m, "\nQueue state:\n");
 477         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
 478         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
 479         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
 480
 481         pkt_count_states(pd, states);
 482         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
 483                    states[0], states[1], states[2], states[3], states[4], states[5]);
 484
 485         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
 486                         pd->write_congestion_off,
 487                         pd->write_congestion_on);
 488         return 0;
 489 }
 490
 491 static int pkt_debugfs_seq_show(struct seq_file *m, void *p)
 492 {
 493         return pkt_seq_show(m, p);
 494 }
 495
 496 static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
 497 {
 498         return single_open(file, pkt_debugfs_seq_show, inode->i_private);
 499 }
 500
 501 static const struct file_operations debug_fops = {
 502         .open           = pkt_debugfs_fops_open,
 503         .read           = seq_read,
 504         .llseek         = seq_lseek,
 505         .release        = single_release,
 506         .owner          = THIS_MODULE,
 507 };
 508
 509 static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
 510 {
 511         if (!pkt_debugfs_root)
 512                 return;
 513         pd->dfs_d_root = debugfs_create_dir(pd->disk->disk_name, pkt_debugfs_root);
 514         if (!pd->dfs_d_root)
 515                 return;
 516
 517         pd->dfs_f_info = debugfs_create_file("info", 0444,
 518                                              pd->dfs_d_root, pd, &debug_fops);
 519 }
 520
 521 static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
 522 {
 523         if (!pkt_debugfs_root)
 524                 return;
 525         debugfs_remove(pd->dfs_f_info);
 526         debugfs_remove(pd->dfs_d_root);
 527         pd->dfs_f_info = NULL;
 528         pd->dfs_d_root = NULL;
 529 }
 530
 531 static void pkt_debugfs_init(void)
 532 {
 533         pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
 534 }
 535
 536 static void pkt_debugfs_cleanup(void)
 537 {
 538         debugfs_remove(pkt_debugfs_root);
 539         pkt_debugfs_root = NULL;
 540 }
 541
 542 /* ----------------------------------------------------------*/
 543
 544
 545 static void pkt_bio_finished(struct pktcdvd_device *pd)
 546 {
 547         struct device *ddev = disk_to_dev(pd->disk);
 548
 549         BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
 550         if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
 551                 dev_dbg(ddev, "queue empty\n");
 552                 atomic_set(&pd->iosched.attention, 1);
 553                 wake_up(&pd->wqueue);
 554         }
 555 }
 556
 557 /*
 558  * Allocate a packet_data struct
 559  */
 560 static struct packet_data *pkt_alloc_packet_data(int frames)
 561 {
 562         int i;
 563         struct packet_data *pkt;
 564
 565         pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
 566         if (!pkt)
 567                 goto no_pkt;
 568
 569         pkt->frames = frames;
 570         pkt->w_bio = bio_kmalloc(frames, GFP_KERNEL);
 571         if (!pkt->w_bio)
 572                 goto no_bio;
 573
 574         for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
 575                 pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
 576                 if (!pkt->pages[i])
 577                         goto no_page;
 578         }
 579
 580         spin_lock_init(&pkt->lock);
 581         bio_list_init(&pkt->orig_bios);
 582
 583         for (i = 0; i < frames; i++) {
 584                 pkt->r_bios[i] = bio_kmalloc(1, GFP_KERNEL);
 585                 if (!pkt->r_bios[i])
 586                         goto no_rd_bio;
 587         }
 588
 589         return pkt;
 590
 591 no_rd_bio:
 592         for (i = 0; i < frames; i++)
 593                 kfree(pkt->r_bios[i]);
 594 no_page:
 595         for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
 596                 if (pkt->pages[i])
 597                         __free_page(pkt->pages[i]);
 598         kfree(pkt->w_bio);
 599 no_bio:
 600         kfree(pkt);
 601 no_pkt:
 602         return NULL;
 603 }
 604
 605 /*
 606  * Free a packet_data struct
 607  */
 608 static void pkt_free_packet_data(struct packet_data *pkt)
 609 {
 610         int i;
 611
 612         for (i = 0; i < pkt->frames; i++)
 613                 kfree(pkt->r_bios[i]);
 614         for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
 615                 __free_page(pkt->pages[i]);
 616         kfree(pkt->w_bio);
 617         kfree(pkt);
 618 }
 619
 620 static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
 621 {
 622         struct packet_data *pkt, *next;
 623
 624         BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
 625
 626         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
 627                 pkt_free_packet_data(pkt);
 628         }
 629         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
 630 }
 631
 632 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
 633 {
 634         struct packet_data *pkt;
 635
 636         BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
 637
 638         while (nr_packets > 0) {
 639                 pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
 640                 if (!pkt) {
 641                         pkt_shrink_pktlist(pd);
 642                         return 0;
 643                 }
 644                 pkt->id = nr_packets;
 645                 pkt->pd = pd;
 646                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
 647                 nr_packets--;
 648         }
 649         return 1;
 650 }
 651
 652 static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
 653 {
 654         struct rb_node *n = rb_next(&node->rb_node);
 655         if (!n)
 656                 return NULL;
 657         return rb_entry(n, struct pkt_rb_node, rb_node);
 658 }
 659
 660 static void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 661 {
 662         rb_erase(&node->rb_node, &pd->bio_queue);
 663         mempool_free(node, &pd->rb_pool);
 664         pd->bio_queue_size--;
 665         BUG_ON(pd->bio_queue_size < 0);
 666 }
 667
 668 /*
 669  * Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
 670  */
 671 static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
 672 {
 673         struct rb_node *n = pd->bio_queue.rb_node;
 674         struct rb_node *next;
 675         struct pkt_rb_node *tmp;
 676
 677         if (!n) {
 678                 BUG_ON(pd->bio_queue_size > 0);
 679                 return NULL;
 680         }
 681
 682         for (;;) {
 683                 tmp = rb_entry(n, struct pkt_rb_node, rb_node);
 684                 if (s <= tmp->bio->bi_iter.bi_sector)
 685                         next = n->rb_left;
 686                 else
 687                         next = n->rb_right;
 688                 if (!next)
 689                         break;
 690                 n = next;
 691         }
 692
 693         if (s > tmp->bio->bi_iter.bi_sector) {
 694                 tmp = pkt_rbtree_next(tmp);
 695                 if (!tmp)
 696                         return NULL;
 697         }
 698         BUG_ON(s > tmp->bio->bi_iter.bi_sector);
 699         return tmp;
 700 }
 701
 702 /*
 703  * Insert a node into the pd->bio_queue rb tree.
 704  */
 705 static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 706 {
 707         struct rb_node **p = &pd->bio_queue.rb_node;
 708         struct rb_node *parent = NULL;
 709         sector_t s = node->bio->bi_iter.bi_sector;
 710         struct pkt_rb_node *tmp;
 711
 712         while (*p) {
 713                 parent = *p;
 714                 tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
 715                 if (s < tmp->bio->bi_iter.bi_sector)
 716                         p = &(*p)->rb_left;
 717                 else
 718                         p = &(*p)->rb_right;
 719         }
 720         rb_link_node(&node->rb_node, parent, p);
 721         rb_insert_color(&node->rb_node, &pd->bio_queue);
 722         pd->bio_queue_size++;
 723 }
 724
 725 /*
 726  * Send a packet_command to the underlying block device and
 727  * wait for completion.
 728  */
 729 static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
 730 {
 731         struct request_queue *q = bdev_get_queue(pd->bdev);
 732         struct scsi_cmnd *scmd;
 733         struct request *rq;
 734         int ret = 0;
 735
 736         rq = scsi_alloc_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
 737                              REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 738         if (IS_ERR(rq))
 739                 return PTR_ERR(rq);
 740         scmd = blk_mq_rq_to_pdu(rq);
 741
 742         if (cgc->buflen) {
 743                 ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
 744                                       GFP_NOIO);
 745                 if (ret)
 746                         goto out;
 747         }
 748
 749         scmd->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
 750         memcpy(scmd->cmnd, cgc->cmd, CDROM_PACKET_SIZE);
 751
 752         rq->timeout = 60*HZ;
 753         if (cgc->quiet)
 754                 rq->rq_flags |= RQF_QUIET;
 755
 756         blk_execute_rq(rq, false);
 757         if (scmd->result)
 758                 ret = -EIO;
 759 out:
 760         blk_mq_free_request(rq);
 761         return ret;
 762 }
 763
 764 static const char *sense_key_string(__u8 index)
 765 {
 766         static const char * const info[] = {
 767                 "No sense", "Recovered error", "Not ready",
 768                 "Medium error", "Hardware error", "Illegal request",
 769                 "Unit attention", "Data protect", "Blank check",
 770         };
 771
 772         return index < ARRAY_SIZE(info) ? info[index] : "INVALID";
 773 }
 774
 775 /*
 776  * A generic sense dump / resolve mechanism should be implemented across
 777  * all ATAPI + SCSI devices.
 778  */
 779 static void pkt_dump_sense(struct pktcdvd_device *pd,
 780                            struct packet_command *cgc)
 781 {
 782         struct device *ddev = disk_to_dev(pd->disk);
 783         struct scsi_sense_hdr *sshdr = cgc->sshdr;
 784
 785         if (sshdr)
 786                 dev_err(ddev, "%*ph - sense %02x.%02x.%02x (%s)\n",
 787                         CDROM_PACKET_SIZE, cgc->cmd,
 788                         sshdr->sense_key, sshdr->asc, sshdr->ascq,
 789                         sense_key_string(sshdr->sense_key));
 790         else
 791                 dev_err(ddev, "%*ph - no sense\n", CDROM_PACKET_SIZE, cgc->cmd);
 792 }
 793
 794 /*
 795  * flush the drive cache to media
 796  */
 797 static int pkt_flush_cache(struct pktcdvd_device *pd)
 798 {
 799         struct packet_command cgc;
 800
 801         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 802         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 803         cgc.quiet = 1;
 804
 805         /*
 806          * the IMMED bit -- we default to not setting it, although that
 807          * would allow a much faster close, this is safer
 808          */
 809 #if 0
 810         cgc.cmd[1] = 1 << 1;
 811 #endif
 812         return pkt_generic_packet(pd, &cgc);
 813 }
 814
 815 /*
 816  * speed is given as the normal factor, e.g. 4 for 4x
 817  */
 818 static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
 819                                 unsigned write_speed, unsigned read_speed)
 820 {
 821         struct packet_command cgc;
 822         struct scsi_sense_hdr sshdr;
 823         int ret;
 824
 825         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 826         cgc.sshdr = &sshdr;
 827         cgc.cmd[0] = GPCMD_SET_SPEED;
 828         cgc.cmd[2] = (read_speed >> 8) & 0xff;
 829         cgc.cmd[3] = read_speed & 0xff;
 830         cgc.cmd[4] = (write_speed >> 8) & 0xff;
 831         cgc.cmd[5] = write_speed & 0xff;
 832
 833         ret = pkt_generic_packet(pd, &cgc);
 834         if (ret)
 835                 pkt_dump_sense(pd, &cgc);
 836
 837         return ret;
 838 }
 839
 840 /*
 841  * Queue a bio for processing by the low-level CD device. Must be called
 842  * from process context.
 843  */
 844 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 845 {
 846         spin_lock(&pd->iosched.lock);
 847         if (bio_data_dir(bio) == READ)
 848                 bio_list_add(&pd->iosched.read_queue, bio);
 849         else
 850                 bio_list_add(&pd->iosched.write_queue, bio);
 851         spin_unlock(&pd->iosched.lock);
 852
 853         atomic_set(&pd->iosched.attention, 1);
 854         wake_up(&pd->wqueue);
 855 }
 856
 857 /*
 858  * Process the queued read/write requests. This function handles special
 859  * requirements for CDRW drives:
 860  * - A cache flush command must be inserted before a read request if the
 861  *   previous request was a write.
 862  * - Switching between reading and writing is slow, so don't do it more often
 863  *   than necessary.
 864  * - Optimize for throughput at the expense of latency. This means that streaming
 865  *   writes will never be interrupted by a read, but if the drive has to seek
 866  *   before the next write, switch to reading instead if there are any pending
 867  *   read requests.
 868  * - Set the read speed according to current usage pattern. When only reading
 869  *   from the device, it's best to use the highest possible read speed, but
 870  *   when switching often between reading and writing, it's better to have the
 871  *   same read and write speeds.
 872  */
 873 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
 874 {
 875         struct device *ddev = disk_to_dev(pd->disk);
 876
 877         if (atomic_read(&pd->iosched.attention) == 0)
 878                 return;
 879         atomic_set(&pd->iosched.attention, 0);
 880
 881         for (;;) {
 882                 struct bio *bio;
 883                 int reads_queued, writes_queued;
 884
 885                 spin_lock(&pd->iosched.lock);
 886                 reads_queued = !bio_list_empty(&pd->iosched.read_queue);
 887                 writes_queued = !bio_list_empty(&pd->iosched.write_queue);
 888                 spin_unlock(&pd->iosched.lock);
 889
 890                 if (!reads_queued && !writes_queued)
 891                         break;
 892
 893                 if (pd->iosched.writing) {
 894                         int need_write_seek = 1;
 895                         spin_lock(&pd->iosched.lock);
 896                         bio = bio_list_peek(&pd->iosched.write_queue);
 897                         spin_unlock(&pd->iosched.lock);
 898                         if (bio && (bio->bi_iter.bi_sector ==
 899                                     pd->iosched.last_write))
 900                                 need_write_seek = 0;
 901                         if (need_write_seek && reads_queued) {
 902                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 903                                         dev_dbg(ddev, "write, waiting\n");
 904                                         break;
 905                                 }
 906                                 pkt_flush_cache(pd);
 907                                 pd->iosched.writing = 0;
 908                         }
 909                 } else {
 910                         if (!reads_queued && writes_queued) {
 911                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 912                                         dev_dbg(ddev, "read, waiting\n");
 913                                         break;
 914                                 }
 915                                 pd->iosched.writing = 1;
 916                         }
 917                 }
 918
 919                 spin_lock(&pd->iosched.lock);
 920                 if (pd->iosched.writing)
 921                         bio = bio_list_pop(&pd->iosched.write_queue);
 922                 else
 923                         bio = bio_list_pop(&pd->iosched.read_queue);
 924                 spin_unlock(&pd->iosched.lock);
 925
 926                 if (!bio)
 927                         continue;
 928
 929                 if (bio_data_dir(bio) == READ)
 930                         pd->iosched.successive_reads +=
 931                                 bio->bi_iter.bi_size >> 10;
 932                 else {
 933                         pd->iosched.successive_reads = 0;
 934                         pd->iosched.last_write = bio_end_sector(bio);
 935                 }
 936                 if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
 937                         if (pd->read_speed == pd->write_speed) {
 938                                 pd->read_speed = MAX_SPEED;
 939                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 940                         }
 941                 } else {
 942                         if (pd->read_speed != pd->write_speed) {
 943                                 pd->read_speed = pd->write_speed;
 944                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 945                         }
 946                 }
 947
 948                 atomic_inc(&pd->cdrw.pending_bios);
 949                 submit_bio_noacct(bio);
 950         }
 951 }
 952
 953 /*
 954  * Special care is needed if the underlying block device has a small
 955  * max_phys_segments value.
 956  */
 957 static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
 958 {
 959         struct device *ddev = disk_to_dev(pd->disk);
 960
 961         if ((pd->settings.size << 9) / CD_FRAMESIZE
 962             <= queue_max_segments(q)) {
 963                 /*
 964                  * The cdrom device can handle one segment/frame
 965                  */
 966                 clear_bit(PACKET_MERGE_SEGS, &pd->flags);
 967                 return 0;
 968         } else if ((pd->settings.size << 9) / PAGE_SIZE
 969                    <= queue_max_segments(q)) {
 970                 /*
 971                  * We can handle this case at the expense of some extra memory
 972                  * copies during write operations
 973                  */
 974                 set_bit(PACKET_MERGE_SEGS, &pd->flags);
 975                 return 0;
 976         } else {
 977                 dev_err(ddev, "cdrom max_phys_segments too small\n");
 978                 return -EIO;
 979         }
 980 }
 981
 982 static void pkt_end_io_read(struct bio *bio)
 983 {
 984         struct packet_data *pkt = bio->bi_private;
 985         struct pktcdvd_device *pd = pkt->pd;
 986         BUG_ON(!pd);
 987
 988         dev_dbg(disk_to_dev(pd->disk), "bio=%p sec0=%llx sec=%llx err=%d\n",
 989                 bio, (unsigned long long)pkt->sector,
 990                 (unsigned long long)bio->bi_iter.bi_sector, bio->bi_status);
 991
 992         if (bio->bi_status)
 993                 atomic_inc(&pkt->io_errors);
 994         bio_uninit(bio);
 995         if (atomic_dec_and_test(&pkt->io_wait)) {
 996                 atomic_inc(&pkt->run_sm);
 997                 wake_up(&pd->wqueue);
 998         }
 999         pkt_bio_finished(pd);
1000 }
1001
1002 static void pkt_end_io_packet_write(struct bio *bio)
1003 {
1004         struct packet_data *pkt = bio->bi_private;
1005         struct pktcdvd_device *pd = pkt->pd;
1006         BUG_ON(!pd);
1007
1008         dev_dbg(disk_to_dev(pd->disk), "id=%d, err=%d\n", pkt->id, bio->bi_status);
1009
1010         pd->stats.pkt_ended++;
1011
1012         bio_uninit(bio);
1013         pkt_bio_finished(pd);
1014         atomic_dec(&pkt->io_wait);
1015         atomic_inc(&pkt->run_sm);
1016         wake_up(&pd->wqueue);
1017 }
1018
1019 /*
1020  * Schedule reads for the holes in a packet
1021  */
1022 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1023 {
1024         struct device *ddev = disk_to_dev(pd->disk);
1025         int frames_read = 0;
1026         struct bio *bio;
1027         int f;
1028         char written[PACKET_MAX_SIZE];
1029
1030         BUG_ON(bio_list_empty(&pkt->orig_bios));
1031
1032         atomic_set(&pkt->io_wait, 0);
1033         atomic_set(&pkt->io_errors, 0);
1034
1035         /*
1036          * Figure out which frames we need to read before we can write.
1037          */
1038         memset(written, 0, sizeof(written));
1039         spin_lock(&pkt->lock);
1040         bio_list_for_each(bio, &pkt->orig_bios) {
1041                 int first_frame = (bio->bi_iter.bi_sector - pkt->sector) /
1042                         (CD_FRAMESIZE >> 9);
1043                 int num_frames = bio->bi_iter.bi_size / CD_FRAMESIZE;
1044                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1045                 BUG_ON(first_frame < 0);
1046                 BUG_ON(first_frame + num_frames > pkt->frames);
1047                 for (f = first_frame; f < first_frame + num_frames; f++)
1048                         written[f] = 1;
1049         }
1050         spin_unlock(&pkt->lock);
1051
1052         if (pkt->cache_valid) {
1053                 dev_dbg(ddev, "zone %llx cached\n", (unsigned long long)pkt->sector);
1054                 goto out_account;
1055         }
1056
1057         /*
1058          * Schedule reads for missing parts of the packet.
1059          */
1060         for (f = 0; f < pkt->frames; f++) {
1061                 int p, offset;
1062
1063                 if (written[f])
1064                         continue;
1065
1066                 bio = pkt->r_bios[f];
1067                 bio_init(bio, pd->bdev, bio->bi_inline_vecs, 1, REQ_OP_READ);
1068                 bio->bi_iter.bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1069                 bio->bi_end_io = pkt_end_io_read;
1070                 bio->bi_private = pkt;
1071
1072                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1073                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1074                 dev_dbg(ddev, "Adding frame %d, page:%p offs:%d\n", f,
1075                         pkt->pages[p], offset);
1076                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1077                         BUG();
1078
1079                 atomic_inc(&pkt->io_wait);
1080                 pkt_queue_bio(pd, bio);
1081                 frames_read++;
1082         }
1083
1084 out_account:
1085         dev_dbg(ddev, "need %d frames for zone %llx\n", frames_read,
1086                 (unsigned long long)pkt->sector);
1087         pd->stats.pkt_started++;
1088         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1089 }
1090
1091 /*
1092  * Find a packet matching zone, or the least recently used packet if
1093  * there is no match.
1094  */
1095 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1096 {
1097         struct packet_data *pkt;
1098
1099         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1100                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1101                         list_del_init(&pkt->list);
1102                         if (pkt->sector != zone)
1103                                 pkt->cache_valid = 0;
1104                         return pkt;
1105                 }
1106         }
1107         BUG();
1108         return NULL;
1109 }
1110
1111 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1112 {
1113         if (pkt->cache_valid) {
1114                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1115         } else {
1116                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1117         }
1118 }
1119
1120 static inline void pkt_set_state(struct device *ddev, struct packet_data *pkt,
1121                                  enum packet_data_state state)
1122 {
1123         static const char *state_name[] = {
1124                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1125         };
1126         enum packet_data_state old_state = pkt->state;
1127
1128         dev_dbg(ddev, "pkt %2d : s=%6llx %s -> %s\n",
1129                 pkt->id, (unsigned long long)pkt->sector,
1130                 state_name[old_state], state_name[state]);
1131
1132         pkt->state = state;
1133 }
1134
1135 /*
1136  * Scan the work queue to see if we can start a new packet.
1137  * returns non-zero if any work was done.
1138  */
1139 static int pkt_handle_queue(struct pktcdvd_device *pd)
1140 {
1141         struct device *ddev = disk_to_dev(pd->disk);
1142         struct packet_data *pkt, *p;
1143         struct bio *bio = NULL;
1144         sector_t zone = 0; /* Suppress gcc warning */
1145         struct pkt_rb_node *node, *first_node;
1146         struct rb_node *n;
1147
1148         atomic_set(&pd->scan_queue, 0);
1149
1150         if (list_empty(&pd->cdrw.pkt_free_list)) {
1151                 dev_dbg(ddev, "no pkt\n");
1152                 return 0;
1153         }
1154
1155         /*
1156          * Try to find a zone we are not already working on.
1157          */
1158         spin_lock(&pd->lock);
1159         first_node = pkt_rbtree_find(pd, pd->current_sector);
1160         if (!first_node) {
1161                 n = rb_first(&pd->bio_queue);
1162                 if (n)
1163                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1164         }
1165         node = first_node;
1166         while (node) {
1167                 bio = node->bio;
1168                 zone = get_zone(bio->bi_iter.bi_sector, pd);
1169                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1170                         if (p->sector == zone) {
1171                                 bio = NULL;
1172                                 goto try_next_bio;
1173                         }
1174                 }
1175                 break;
1176 try_next_bio:
1177                 node = pkt_rbtree_next(node);
1178                 if (!node) {
1179                         n = rb_first(&pd->bio_queue);
1180                         if (n)
1181                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1182                 }
1183                 if (node == first_node)
1184                         node = NULL;
1185         }
1186         spin_unlock(&pd->lock);
1187         if (!bio) {
1188                 dev_dbg(ddev, "no bio\n");
1189                 return 0;
1190         }
1191
1192         pkt = pkt_get_packet_data(pd, zone);
1193
1194         pd->current_sector = zone + pd->settings.size;
1195         pkt->sector = zone;
1196         BUG_ON(pkt->frames != pd->settings.size >> 2);
1197         pkt->write_size = 0;
1198
1199         /*
1200          * Scan work queue for bios in the same zone and link them
1201          * to this packet.
1202          */
1203         spin_lock(&pd->lock);
1204         dev_dbg(ddev, "looking for zone %llx\n", (unsigned long long)zone);
1205         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1206                 sector_t tmp = get_zone(node->bio->bi_iter.bi_sector, pd);
1207
1208                 bio = node->bio;
1209                 dev_dbg(ddev, "found zone=%llx\n", (unsigned long long)tmp);
1210                 if (tmp != zone)
1211                         break;
1212                 pkt_rbtree_erase(pd, node);
1213                 spin_lock(&pkt->lock);
1214                 bio_list_add(&pkt->orig_bios, bio);
1215                 pkt->write_size += bio->bi_iter.bi_size / CD_FRAMESIZE;
1216                 spin_unlock(&pkt->lock);
1217         }
1218         /* check write congestion marks, and if bio_queue_size is
1219          * below, wake up any waiters
1220          */
1221         if (pd->congested &&
1222             pd->bio_queue_size <= pd->write_congestion_off) {
1223                 pd->congested = false;
1224                 wake_up_var(&pd->congested);
1225         }
1226         spin_unlock(&pd->lock);
1227
1228         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1229         pkt_set_state(ddev, pkt, PACKET_WAITING_STATE);
1230         atomic_set(&pkt->run_sm, 1);
1231
1232         spin_lock(&pd->cdrw.active_list_lock);
1233         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1234         spin_unlock(&pd->cdrw.active_list_lock);
1235
1236         return 1;
1237 }
1238
1239 /**
1240  * bio_list_copy_data - copy contents of data buffers from one chain of bios to
1241  * another
1242  * @src: source bio list
1243  * @dst: destination bio list
1244  *
1245  * Stops when it reaches the end of either the @src list or @dst list - that is,
1246  * copies min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of
1247  * bios).
1248  */
1249 static void bio_list_copy_data(struct bio *dst, struct bio *src)
1250 {
1251         struct bvec_iter src_iter = src->bi_iter;
1252         struct bvec_iter dst_iter = dst->bi_iter;
1253
1254         while (1) {
1255                 if (!src_iter.bi_size) {
1256                         src = src->bi_next;
1257                         if (!src)
1258                                 break;
1259
1260                         src_iter = src->bi_iter;
1261                 }
1262
1263                 if (!dst_iter.bi_size) {
1264                         dst = dst->bi_next;
1265                         if (!dst)
1266                                 break;
1267
1268                         dst_iter = dst->bi_iter;
1269                 }
1270
1271                 bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
1272         }
1273 }
1274
1275 /*
1276  * Assemble a bio to write one packet and queue the bio for processing
1277  * by the underlying block device.
1278  */
1279 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1280 {
1281         struct device *ddev = disk_to_dev(pd->disk);
1282         int f;
1283
1284         bio_init(pkt->w_bio, pd->bdev, pkt->w_bio->bi_inline_vecs, pkt->frames,
1285                  REQ_OP_WRITE);
1286         pkt->w_bio->bi_iter.bi_sector = pkt->sector;
1287         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1288         pkt->w_bio->bi_private = pkt;
1289
1290         /* XXX: locking? */
1291         for (f = 0; f < pkt->frames; f++) {
1292                 struct page *page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1293                 unsigned offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1294
1295                 if (!bio_add_page(pkt->w_bio, page, CD_FRAMESIZE, offset))
1296                         BUG();
1297         }
1298         dev_dbg(ddev, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
1299
1300         /*
1301          * Fill-in bvec with data from orig_bios.
1302          */
1303         spin_lock(&pkt->lock);
1304         bio_list_copy_data(pkt->w_bio, pkt->orig_bios.head);
1305
1306         pkt_set_state(ddev, pkt, PACKET_WRITE_WAIT_STATE);
1307         spin_unlock(&pkt->lock);
1308
1309         dev_dbg(ddev, "Writing %d frames for zone %llx\n", pkt->write_size,
1310                 (unsigned long long)pkt->sector);
1311
1312         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames))
1313                 pkt->cache_valid = 1;
1314         else
1315                 pkt->cache_valid = 0;
1316
1317         /* Start the write request */
1318         atomic_set(&pkt->io_wait, 1);
1319         pkt_queue_bio(pd, pkt->w_bio);
1320 }
1321
1322 static void pkt_finish_packet(struct packet_data *pkt, blk_status_t status)
1323 {
1324         struct bio *bio;
1325
1326         if (status)
1327                 pkt->cache_valid = 0;
1328
1329         /* Finish all bios corresponding to this packet */
1330         while ((bio = bio_list_pop(&pkt->orig_bios))) {
1331                 bio->bi_status = status;
1332                 bio_endio(bio);
1333         }
1334 }
1335
1336 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1337 {
1338         struct device *ddev = disk_to_dev(pd->disk);
1339
1340         dev_dbg(ddev, "pkt %d\n", pkt->id);
1341
1342         for (;;) {
1343                 switch (pkt->state) {
1344                 case PACKET_WAITING_STATE:
1345                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1346                                 return;
1347
1348                         pkt->sleep_time = 0;
1349                         pkt_gather_data(pd, pkt);
1350                         pkt_set_state(ddev, pkt, PACKET_READ_WAIT_STATE);
1351                         break;
1352
1353                 case PACKET_READ_WAIT_STATE:
1354                         if (atomic_read(&pkt->io_wait) > 0)
1355                                 return;
1356
1357                         if (atomic_read(&pkt->io_errors) > 0) {
1358                                 pkt_set_state(ddev, pkt, PACKET_RECOVERY_STATE);
1359                         } else {
1360                                 pkt_start_write(pd, pkt);
1361                         }
1362                         break;
1363
1364                 case PACKET_WRITE_WAIT_STATE:
1365                         if (atomic_read(&pkt->io_wait) > 0)
1366                                 return;
1367
1368                         if (!pkt->w_bio->bi_status) {
1369                                 pkt_set_state(ddev, pkt, PACKET_FINISHED_STATE);
1370                         } else {
1371                                 pkt_set_state(ddev, pkt, PACKET_RECOVERY_STATE);
1372                         }
1373                         break;
1374
1375                 case PACKET_RECOVERY_STATE:
1376                         dev_dbg(ddev, "No recovery possible\n");
1377                         pkt_set_state(ddev, pkt, PACKET_FINISHED_STATE);
1378                         break;
1379
1380                 case PACKET_FINISHED_STATE:
1381                         pkt_finish_packet(pkt, pkt->w_bio->bi_status);
1382                         return;
1383
1384                 default:
1385                         BUG();
1386                         break;
1387                 }
1388         }
1389 }
1390
1391 static void pkt_handle_packets(struct pktcdvd_device *pd)
1392 {
1393         struct device *ddev = disk_to_dev(pd->disk);
1394         struct packet_data *pkt, *next;
1395
1396         /*
1397          * Run state machine for active packets
1398          */
1399         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1400                 if (atomic_read(&pkt->run_sm) > 0) {
1401                         atomic_set(&pkt->run_sm, 0);
1402                         pkt_run_state_machine(pd, pkt);
1403                 }
1404         }
1405
1406         /*
1407          * Move no longer active packets to the free list
1408          */
1409         spin_lock(&pd->cdrw.active_list_lock);
1410         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1411                 if (pkt->state == PACKET_FINISHED_STATE) {
1412                         list_del(&pkt->list);
1413                         pkt_put_packet_data(pd, pkt);
1414                         pkt_set_state(ddev, pkt, PACKET_IDLE_STATE);
1415                         atomic_set(&pd->scan_queue, 1);
1416                 }
1417         }
1418         spin_unlock(&pd->cdrw.active_list_lock);
1419 }
1420
1421 /*
1422  * kcdrwd is woken up when writes have been queued for one of our
1423  * registered devices
1424  */
1425 static int kcdrwd(void *foobar)
1426 {
1427         struct pktcdvd_device *pd = foobar;
1428         struct device *ddev = disk_to_dev(pd->disk);
1429         struct packet_data *pkt;
1430         int states[PACKET_NUM_STATES];
1431         long min_sleep_time, residue;
1432
1433         set_user_nice(current, MIN_NICE);
1434         set_freezable();
1435
1436         for (;;) {
1437                 DECLARE_WAITQUEUE(wait, current);
1438
1439                 /*
1440                  * Wait until there is something to do
1441                  */
1442                 add_wait_queue(&pd->wqueue, &wait);
1443                 for (;;) {
1444                         set_current_state(TASK_INTERRUPTIBLE);
1445
1446                         /* Check if we need to run pkt_handle_queue */
1447                         if (atomic_read(&pd->scan_queue) > 0)
1448                                 goto work_to_do;
1449
1450                         /* Check if we need to run the state machine for some packet */
1451                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1452                                 if (atomic_read(&pkt->run_sm) > 0)
1453                                         goto work_to_do;
1454                         }
1455
1456                         /* Check if we need to process the iosched queues */
1457                         if (atomic_read(&pd->iosched.attention) != 0)
1458                                 goto work_to_do;
1459
1460                         /* Otherwise, go to sleep */
1461                         pkt_count_states(pd, states);
1462                         dev_dbg(ddev, "i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1463                                 states[0], states[1], states[2], states[3], states[4], states[5]);
1464
1465                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1466                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1467                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1468                                         min_sleep_time = pkt->sleep_time;
1469                         }
1470
1471                         dev_dbg(ddev, "sleeping\n");
1472                         residue = schedule_timeout(min_sleep_time);
1473                         dev_dbg(ddev, "wake up\n");
1474
1475                         /* make swsusp happy with our thread */
1476                         try_to_freeze();
1477
1478                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1479                                 if (!pkt->sleep_time)
1480                                         continue;
1481                                 pkt->sleep_time -= min_sleep_time - residue;
1482                                 if (pkt->sleep_time <= 0) {
1483                                         pkt->sleep_time = 0;
1484                                         atomic_inc(&pkt->run_sm);
1485                                 }
1486                         }
1487
1488                         if (kthread_should_stop())
1489                                 break;
1490                 }
1491 work_to_do:
1492                 set_current_state(TASK_RUNNING);
1493                 remove_wait_queue(&pd->wqueue, &wait);
1494
1495                 if (kthread_should_stop())
1496                         break;
1497
1498                 /*
1499                  * if pkt_handle_queue returns true, we can queue
1500                  * another request.
1501                  */
1502                 while (pkt_handle_queue(pd))
1503                         ;
1504
1505                 /*
1506                  * Handle packet state machine
1507                  */
1508                 pkt_handle_packets(pd);
1509
1510                 /*
1511                  * Handle iosched queues
1512                  */
1513                 pkt_iosched_process_queue(pd);
1514         }
1515
1516         return 0;
1517 }
1518
1519 static void pkt_print_settings(struct pktcdvd_device *pd)
1520 {
1521         dev_info(disk_to_dev(pd->disk), "%s packets, %u blocks, Mode-%c disc\n",
1522                  pd->settings.fp ? "Fixed" : "Variable",
1523                  pd->settings.size >> 2,
1524                  pd->settings.block_mode == 8 ? '1' : '2');
1525 }
1526
1527 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1528 {
1529         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1530
1531         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1532         cgc->cmd[2] = page_code | (page_control << 6);
1533         cgc->cmd[7] = cgc->buflen >> 8;
1534         cgc->cmd[8] = cgc->buflen & 0xff;
1535         cgc->data_direction = CGC_DATA_READ;
1536         return pkt_generic_packet(pd, cgc);
1537 }
1538
1539 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1540 {
1541         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1542         memset(cgc->buffer, 0, 2);
1543         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1544         cgc->cmd[1] = 0x10;             /* PF */
1545         cgc->cmd[7] = cgc->buflen >> 8;
1546         cgc->cmd[8] = cgc->buflen & 0xff;
1547         cgc->data_direction = CGC_DATA_WRITE;
1548         return pkt_generic_packet(pd, cgc);
1549 }
1550
1551 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1552 {
1553         struct packet_command cgc;
1554         int ret;
1555
1556         /* set up command and get the disc info */
1557         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1558         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1559         cgc.cmd[8] = cgc.buflen = 2;
1560         cgc.quiet = 1;
1561
1562         ret = pkt_generic_packet(pd, &cgc);
1563         if (ret)
1564                 return ret;
1565
1566         /* not all drives have the same disc_info length, so requeue
1567          * packet with the length the drive tells us it can supply
1568          */
1569         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1570                      sizeof(di->disc_information_length);
1571
1572         if (cgc.buflen > sizeof(disc_information))
1573                 cgc.buflen = sizeof(disc_information);
1574
1575         cgc.cmd[8] = cgc.buflen;
1576         return pkt_generic_packet(pd, &cgc);
1577 }
1578
1579 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1580 {
1581         struct packet_command cgc;
1582         int ret;
1583
1584         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1585         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1586         cgc.cmd[1] = type & 3;
1587         cgc.cmd[4] = (track & 0xff00) >> 8;
1588         cgc.cmd[5] = track & 0xff;
1589         cgc.cmd[8] = 8;
1590         cgc.quiet = 1;
1591
1592         ret = pkt_generic_packet(pd, &cgc);
1593         if (ret)
1594                 return ret;
1595
1596         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1597                      sizeof(ti->track_information_length);
1598
1599         if (cgc.buflen > sizeof(track_information))
1600                 cgc.buflen = sizeof(track_information);
1601
1602         cgc.cmd[8] = cgc.buflen;
1603         return pkt_generic_packet(pd, &cgc);
1604 }
1605
1606 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1607                                                 long *last_written)
1608 {
1609         disc_information di;
1610         track_information ti;
1611         __u32 last_track;
1612         int ret;
1613
1614         ret = pkt_get_disc_info(pd, &di);
1615         if (ret)
1616                 return ret;
1617
1618         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1619         ret = pkt_get_track_info(pd, last_track, 1, &ti);
1620         if (ret)
1621                 return ret;
1622
1623         /* if this track is blank, try the previous. */
1624         if (ti.blank) {
1625                 last_track--;
1626                 ret = pkt_get_track_info(pd, last_track, 1, &ti);
1627                 if (ret)
1628                         return ret;
1629         }
1630
1631         /* if last recorded field is valid, return it. */
1632         if (ti.lra_v) {
1633                 *last_written = be32_to_cpu(ti.last_rec_address);
1634         } else {
1635                 /* make it up instead */
1636                 *last_written = be32_to_cpu(ti.track_start) +
1637                                 be32_to_cpu(ti.track_size);
1638                 if (ti.free_blocks)
1639                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1640         }
1641         return 0;
1642 }
1643
1644 /*
1645  * write mode select package based on pd->settings
1646  */
1647 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1648 {
1649         struct device *ddev = disk_to_dev(pd->disk);
1650         struct packet_command cgc;
1651         struct scsi_sense_hdr sshdr;
1652         write_param_page *wp;
1653         char buffer[128];
1654         int ret, size;
1655
1656         /* doesn't apply to DVD+RW or DVD-RAM */
1657         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1658                 return 0;
1659
1660         memset(buffer, 0, sizeof(buffer));
1661         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1662         cgc.sshdr = &sshdr;
1663         ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1664         if (ret) {
1665                 pkt_dump_sense(pd, &cgc);
1666                 return ret;
1667         }
1668
1669         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1670         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1671         if (size > sizeof(buffer))
1672                 size = sizeof(buffer);
1673
1674         /*
1675          * now get it all
1676          */
1677         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1678         cgc.sshdr = &sshdr;
1679         ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1680         if (ret) {
1681                 pkt_dump_sense(pd, &cgc);
1682                 return ret;
1683         }
1684
1685         /*
1686          * write page is offset header + block descriptor length
1687          */
1688         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1689
1690         wp->fp = pd->settings.fp;
1691         wp->track_mode = pd->settings.track_mode;
1692         wp->write_type = pd->settings.write_type;
1693         wp->data_block_type = pd->settings.block_mode;
1694
1695         wp->multi_session = 0;
1696
1697 #ifdef PACKET_USE_LS
1698         wp->link_size = 7;
1699         wp->ls_v = 1;
1700 #endif
1701
1702         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1703                 wp->session_format = 0;
1704                 wp->subhdr2 = 0x20;
1705         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1706                 wp->session_format = 0x20;
1707                 wp->subhdr2 = 8;
1708 #if 0
1709                 wp->mcn[0] = 0x80;
1710                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1711 #endif
1712         } else {
1713                 /*
1714                  * paranoia
1715                  */
1716                 dev_err(ddev, "write mode wrong %d\n", wp->data_block_type);
1717                 return 1;
1718         }
1719         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1720
1721         cgc.buflen = cgc.cmd[8] = size;
1722         ret = pkt_mode_select(pd, &cgc);
1723         if (ret) {
1724                 pkt_dump_sense(pd, &cgc);
1725                 return ret;
1726         }
1727
1728         pkt_print_settings(pd);
1729         return 0;
1730 }
1731
1732 /*
1733  * 1 -- we can write to this track, 0 -- we can't
1734  */
1735 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1736 {
1737         struct device *ddev = disk_to_dev(pd->disk);
1738
1739         switch (pd->mmc3_profile) {
1740                 case 0x1a: /* DVD+RW */
1741                 case 0x12: /* DVD-RAM */
1742                         /* The track is always writable on DVD+RW/DVD-RAM */
1743                         return 1;
1744                 default:
1745                         break;
1746         }
1747
1748         if (!ti->packet || !ti->fp)
1749                 return 0;
1750
1751         /*
1752          * "good" settings as per Mt Fuji.
1753          */
1754         if (ti->rt == 0 && ti->blank == 0)
1755                 return 1;
1756
1757         if (ti->rt == 0 && ti->blank == 1)
1758                 return 1;
1759
1760         if (ti->rt == 1 && ti->blank == 0)
1761                 return 1;
1762
1763         dev_err(ddev, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1764         return 0;
1765 }
1766
1767 /*
1768  * 1 -- we can write to this disc, 0 -- we can't
1769  */
1770 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1771 {
1772         struct device *ddev = disk_to_dev(pd->disk);
1773
1774         switch (pd->mmc3_profile) {
1775                 case 0x0a: /* CD-RW */
1776                 case 0xffff: /* MMC3 not supported */
1777                         break;
1778                 case 0x1a: /* DVD+RW */
1779                 case 0x13: /* DVD-RW */
1780                 case 0x12: /* DVD-RAM */
1781                         return 1;
1782                 default:
1783                         dev_dbg(ddev, "Wrong disc profile (%x)\n", pd->mmc3_profile);
1784                         return 0;
1785         }
1786
1787         /*
1788          * for disc type 0xff we should probably reserve a new track.
1789          * but i'm not sure, should we leave this to user apps? probably.
1790          */
1791         if (di->disc_type == 0xff) {
1792                 dev_notice(ddev, "unknown disc - no track?\n");
1793                 return 0;
1794         }
1795
1796         if (di->disc_type != 0x20 && di->disc_type != 0) {
1797                 dev_err(ddev, "wrong disc type (%x)\n", di->disc_type);
1798                 return 0;
1799         }
1800
1801         if (di->erasable == 0) {
1802                 dev_err(ddev, "disc not erasable\n");
1803                 return 0;
1804         }
1805
1806         if (di->border_status == PACKET_SESSION_RESERVED) {
1807                 dev_err(ddev, "can't write to last track (reserved)\n");
1808                 return 0;
1809         }
1810
1811         return 1;
1812 }
1813
1814 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1815 {
1816         struct device *ddev = disk_to_dev(pd->disk);
1817         struct packet_command cgc;
1818         unsigned char buf[12];
1819         disc_information di;
1820         track_information ti;
1821         int ret, track;
1822
1823         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1824         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1825         cgc.cmd[8] = 8;
1826         ret = pkt_generic_packet(pd, &cgc);
1827         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1828
1829         memset(&di, 0, sizeof(disc_information));
1830         memset(&ti, 0, sizeof(track_information));
1831
1832         ret = pkt_get_disc_info(pd, &di);
1833         if (ret) {
1834                 dev_err(ddev, "failed get_disc\n");
1835                 return ret;
1836         }
1837
1838         if (!pkt_writable_disc(pd, &di))
1839                 return -EROFS;
1840
1841         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1842
1843         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1844         ret = pkt_get_track_info(pd, track, 1, &ti);
1845         if (ret) {
1846                 dev_err(ddev, "failed get_track\n");
1847                 return ret;
1848         }
1849
1850         if (!pkt_writable_track(pd, &ti)) {
1851                 dev_err(ddev, "can't write to this track\n");
1852                 return -EROFS;
1853         }
1854
1855         /*
1856          * we keep packet size in 512 byte units, makes it easier to
1857          * deal with request calculations.
1858          */
1859         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1860         if (pd->settings.size == 0) {
1861                 dev_notice(ddev, "detected zero packet size!\n");
1862                 return -ENXIO;
1863         }
1864         if (pd->settings.size > PACKET_MAX_SECTORS) {
1865                 dev_err(ddev, "packet size is too big\n");
1866                 return -EROFS;
1867         }
1868         pd->settings.fp = ti.fp;
1869         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1870
1871         if (ti.nwa_v) {
1872                 pd->nwa = be32_to_cpu(ti.next_writable);
1873                 set_bit(PACKET_NWA_VALID, &pd->flags);
1874         }
1875
1876         /*
1877          * in theory we could use lra on -RW media as well and just zero
1878          * blocks that haven't been written yet, but in practice that
1879          * is just a no-go. we'll use that for -R, naturally.
1880          */
1881         if (ti.lra_v) {
1882                 pd->lra = be32_to_cpu(ti.last_rec_address);
1883                 set_bit(PACKET_LRA_VALID, &pd->flags);
1884         } else {
1885                 pd->lra = 0xffffffff;
1886                 set_bit(PACKET_LRA_VALID, &pd->flags);
1887         }
1888
1889         /*
1890          * fine for now
1891          */
1892         pd->settings.link_loss = 7;
1893         pd->settings.write_type = 0;    /* packet */
1894         pd->settings.track_mode = ti.track_mode;
1895
1896         /*
1897          * mode1 or mode2 disc
1898          */
1899         switch (ti.data_mode) {
1900                 case PACKET_MODE1:
1901                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
1902                         break;
1903                 case PACKET_MODE2:
1904                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
1905                         break;
1906                 default:
1907                         dev_err(ddev, "unknown data mode\n");
1908                         return -EROFS;
1909         }
1910         return 0;
1911 }
1912
1913 /*
1914  * enable/disable write caching on drive
1915  */
1916 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd)
1917 {
1918         struct device *ddev = disk_to_dev(pd->disk);
1919         struct packet_command cgc;
1920         struct scsi_sense_hdr sshdr;
1921         unsigned char buf[64];
1922         bool set = IS_ENABLED(CONFIG_CDROM_PKTCDVD_WCACHE);
1923         int ret;
1924
1925         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1926         cgc.sshdr = &sshdr;
1927         cgc.buflen = pd->mode_offset + 12;
1928
1929         /*
1930          * caching mode page might not be there, so quiet this command
1931          */
1932         cgc.quiet = 1;
1933
1934         ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0);
1935         if (ret)
1936                 return ret;
1937
1938         /*
1939          * use drive write caching -- we need deferred error handling to be
1940          * able to successfully recover with this option (drive will return good
1941          * status as soon as the cdb is validated).
1942          */
1943         buf[pd->mode_offset + 10] |= (set << 2);
1944
1945         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
1946         ret = pkt_mode_select(pd, &cgc);
1947         if (ret) {
1948                 dev_err(ddev, "write caching control failed\n");
1949                 pkt_dump_sense(pd, &cgc);
1950         } else if (!ret && set)
1951                 dev_notice(ddev, "enabled write caching\n");
1952         return ret;
1953 }
1954
1955 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1956 {
1957         struct packet_command cgc;
1958
1959         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1960         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1961         cgc.cmd[4] = lockflag ? 1 : 0;
1962         return pkt_generic_packet(pd, &cgc);
1963 }
1964
1965 /*
1966  * Returns drive maximum write speed
1967  */
1968 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1969                                                 unsigned *write_speed)
1970 {
1971         struct packet_command cgc;
1972         struct scsi_sense_hdr sshdr;
1973         unsigned char buf[256+18];
1974         unsigned char *cap_buf;
1975         int ret, offset;
1976
1977         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1978         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1979         cgc.sshdr = &sshdr;
1980
1981         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1982         if (ret) {
1983                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
1984                              sizeof(struct mode_page_header);
1985                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1986                 if (ret) {
1987                         pkt_dump_sense(pd, &cgc);
1988                         return ret;
1989                 }
1990         }
1991
1992         offset = 20;                        /* Obsoleted field, used by older drives */
1993         if (cap_buf[1] >= 28)
1994                 offset = 28;                /* Current write speed selected */
1995         if (cap_buf[1] >= 30) {
1996                 /* If the drive reports at least one "Logical Unit Write
1997                  * Speed Performance Descriptor Block", use the information
1998                  * in the first block. (contains the highest speed)
1999                  */
2000                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
2001                 if (num_spdb > 0)
2002                         offset = 34;
2003         }
2004
2005         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
2006         return 0;
2007 }
2008
2009 /* These tables from cdrecord - I don't have orange book */
2010 /* standard speed CD-RW (1-4x) */
2011 static char clv_to_speed[16] = {
2012         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2013            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2014 };
2015 /* high speed CD-RW (-10x) */
2016 static char hs_clv_to_speed[16] = {
2017         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2018            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2019 };
2020 /* ultra high speed CD-RW */
2021 static char us_clv_to_speed[16] = {
2022         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2023            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2024 };
2025
2026 /*
2027  * reads the maximum media speed from ATIP
2028  */
2029 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2030                                                 unsigned *speed)
2031 {
2032         struct device *ddev = disk_to_dev(pd->disk);
2033         struct packet_command cgc;
2034         struct scsi_sense_hdr sshdr;
2035         unsigned char buf[64];
2036         unsigned int size, st, sp;
2037         int ret;
2038
2039         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2040         cgc.sshdr = &sshdr;
2041         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2042         cgc.cmd[1] = 2;
2043         cgc.cmd[2] = 4; /* READ ATIP */
2044         cgc.cmd[8] = 2;
2045         ret = pkt_generic_packet(pd, &cgc);
2046         if (ret) {
2047                 pkt_dump_sense(pd, &cgc);
2048                 return ret;
2049         }
2050         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2051         if (size > sizeof(buf))
2052                 size = sizeof(buf);
2053
2054         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2055         cgc.sshdr = &sshdr;
2056         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2057         cgc.cmd[1] = 2;
2058         cgc.cmd[2] = 4;
2059         cgc.cmd[8] = size;
2060         ret = pkt_generic_packet(pd, &cgc);
2061         if (ret) {
2062                 pkt_dump_sense(pd, &cgc);
2063                 return ret;
2064         }
2065
2066         if (!(buf[6] & 0x40)) {
2067                 dev_notice(ddev, "disc type is not CD-RW\n");
2068                 return 1;
2069         }
2070         if (!(buf[6] & 0x4)) {
2071                 dev_notice(ddev, "A1 values on media are not valid, maybe not CDRW?\n");
2072                 return 1;
2073         }
2074
2075         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2076
2077         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2078
2079         /* Info from cdrecord */
2080         switch (st) {
2081                 case 0: /* standard speed */
2082                         *speed = clv_to_speed[sp];
2083                         break;
2084                 case 1: /* high speed */
2085                         *speed = hs_clv_to_speed[sp];
2086                         break;
2087                 case 2: /* ultra high speed */
2088                         *speed = us_clv_to_speed[sp];
2089                         break;
2090                 default:
2091                         dev_notice(ddev, "unknown disc sub-type %d\n", st);
2092                         return 1;
2093         }
2094         if (*speed) {
2095                 dev_info(ddev, "maximum media speed: %d\n", *speed);
2096                 return 0;
2097         } else {
2098                 dev_notice(ddev, "unknown speed %d for sub-type %d\n", sp, st);
2099                 return 1;
2100         }
2101 }
2102
2103 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2104 {
2105         struct device *ddev = disk_to_dev(pd->disk);
2106         struct packet_command cgc;
2107         struct scsi_sense_hdr sshdr;
2108         int ret;
2109
2110         dev_dbg(ddev, "Performing OPC\n");
2111
2112         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2113         cgc.sshdr = &sshdr;
2114         cgc.timeout = 60*HZ;
2115         cgc.cmd[0] = GPCMD_SEND_OPC;
2116         cgc.cmd[1] = 1;
2117         ret = pkt_generic_packet(pd, &cgc);
2118         if (ret)
2119                 pkt_dump_sense(pd, &cgc);
2120         return ret;
2121 }
2122
2123 static int pkt_open_write(struct pktcdvd_device *pd)
2124 {
2125         struct device *ddev = disk_to_dev(pd->disk);
2126         int ret;
2127         unsigned int write_speed, media_write_speed, read_speed;
2128
2129         ret = pkt_probe_settings(pd);
2130         if (ret) {
2131                 dev_dbg(ddev, "failed probe\n");
2132                 return ret;
2133         }
2134
2135         ret = pkt_set_write_settings(pd);
2136         if (ret) {
2137                 dev_notice(ddev, "failed saving write settings\n");
2138                 return -EIO;
2139         }
2140
2141         pkt_write_caching(pd);
2142
2143         ret = pkt_get_max_speed(pd, &write_speed);
2144         if (ret)
2145                 write_speed = 16 * 177;
2146         switch (pd->mmc3_profile) {
2147                 case 0x13: /* DVD-RW */
2148                 case 0x1a: /* DVD+RW */
2149                 case 0x12: /* DVD-RAM */
2150                         dev_notice(ddev, "write speed %ukB/s\n", write_speed);
2151                         break;
2152                 default:
2153                         ret = pkt_media_speed(pd, &media_write_speed);
2154                         if (ret)
2155                                 media_write_speed = 16;
2156                         write_speed = min(write_speed, media_write_speed * 177);
2157                         dev_notice(ddev, "write speed %ux\n", write_speed / 176);
2158                         break;
2159         }
2160         read_speed = write_speed;
2161
2162         ret = pkt_set_speed(pd, write_speed, read_speed);
2163         if (ret) {
2164                 dev_notice(ddev, "couldn't set write speed\n");
2165                 return -EIO;
2166         }
2167         pd->write_speed = write_speed;
2168         pd->read_speed = read_speed;
2169
2170         ret = pkt_perform_opc(pd);
2171         if (ret)
2172                 dev_notice(ddev, "Optimum Power Calibration failed\n");
2173
2174         return 0;
2175 }
2176
2177 /*
2178  * called at open time.
2179  */
2180 static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2181 {
2182         struct device *ddev = disk_to_dev(pd->disk);
2183         int ret;
2184         long lba;
2185         struct request_queue *q;
2186         struct block_device *bdev;
2187
2188         /*
2189          * We need to re-open the cdrom device without O_NONBLOCK to be able
2190          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2191          * so open should not fail.
2192          */
2193         bdev = blkdev_get_by_dev(pd->bdev->bd_dev, FMODE_READ | FMODE_EXCL, pd,
2194                                  NULL);
2195         if (IS_ERR(bdev)) {
2196                 ret = PTR_ERR(bdev);
2197                 goto out;
2198         }
2199
2200         ret = pkt_get_last_written(pd, &lba);
2201         if (ret) {
2202                 dev_err(ddev, "pkt_get_last_written failed\n");
2203                 goto out_putdev;
2204         }
2205
2206         set_capacity(pd->disk, lba << 2);
2207         set_capacity_and_notify(pd->bdev->bd_disk, lba << 2);
2208
2209         q = bdev_get_queue(pd->bdev);
2210         if (write) {
2211                 ret = pkt_open_write(pd);
2212                 if (ret)
2213                         goto out_putdev;
2214                 /*
2215                  * Some CDRW drives can not handle writes larger than one packet,
2216                  * even if the size is a multiple of the packet size.
2217                  */
2218                 blk_queue_max_hw_sectors(q, pd->settings.size);
2219                 set_bit(PACKET_WRITABLE, &pd->flags);
2220         } else {
2221                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2222                 clear_bit(PACKET_WRITABLE, &pd->flags);
2223         }
2224
2225         ret = pkt_set_segment_merging(pd, q);
2226         if (ret)
2227                 goto out_putdev;
2228
2229         if (write) {
2230                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2231                         dev_err(ddev, "not enough memory for buffers\n");
2232                         ret = -ENOMEM;
2233                         goto out_putdev;
2234                 }
2235                 dev_info(ddev, "%lukB available on disc\n", lba << 1);
2236         }
2237
2238         return 0;
2239
2240 out_putdev:
2241         blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
2242 out:
2243         return ret;
2244 }
2245
2246 /*
2247  * called when the device is closed. makes sure that the device flushes
2248  * the internal cache before we close.
2249  */
2250 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2251 {
2252         struct device *ddev = disk_to_dev(pd->disk);
2253
2254         if (flush && pkt_flush_cache(pd))
2255                 dev_notice(ddev, "not flushing cache\n");
2256
2257         pkt_lock_door(pd, 0);
2258
2259         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2260         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2261
2262         pkt_shrink_pktlist(pd);
2263 }
2264
2265 static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2266 {
2267         if (dev_minor >= MAX_WRITERS)
2268                 return NULL;
2269
2270         dev_minor = array_index_nospec(dev_minor, MAX_WRITERS);
2271         return pkt_devs[dev_minor];
2272 }
2273
2274 static int pkt_open(struct block_device *bdev, fmode_t mode)
2275 {
2276         struct pktcdvd_device *pd = NULL;
2277         int ret;
2278
2279         mutex_lock(&pktcdvd_mutex);
2280         mutex_lock(&ctl_mutex);
2281         pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2282         if (!pd) {
2283                 ret = -ENODEV;
2284                 goto out;
2285         }
2286         BUG_ON(pd->refcnt < 0);
2287
2288         pd->refcnt++;
2289         if (pd->refcnt > 1) {
2290                 if ((mode & FMODE_WRITE) &&
2291                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2292                         ret = -EBUSY;
2293                         goto out_dec;
2294                 }
2295         } else {
2296                 ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2297                 if (ret)
2298                         goto out_dec;
2299                 /*
2300                  * needed here as well, since ext2 (among others) may change
2301                  * the blocksize at mount time
2302                  */
2303                 set_blocksize(bdev, CD_FRAMESIZE);
2304         }
2305
2306         mutex_unlock(&ctl_mutex);
2307         mutex_unlock(&pktcdvd_mutex);
2308         return 0;
2309
2310 out_dec:
2311         pd->refcnt--;
2312 out:
2313         mutex_unlock(&ctl_mutex);
2314         mutex_unlock(&pktcdvd_mutex);
2315         return ret;
2316 }
2317
2318 static void pkt_close(struct gendisk *disk, fmode_t mode)
2319 {
2320         struct pktcdvd_device *pd = disk->private_data;
2321
2322         mutex_lock(&pktcdvd_mutex);
2323         mutex_lock(&ctl_mutex);
2324         pd->refcnt--;
2325         BUG_ON(pd->refcnt < 0);
2326         if (pd->refcnt == 0) {
2327                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2328                 pkt_release_dev(pd, flush);
2329         }
2330         mutex_unlock(&ctl_mutex);
2331         mutex_unlock(&pktcdvd_mutex);
2332 }
2333
2334
2335 static void pkt_end_io_read_cloned(struct bio *bio)
2336 {
2337         struct packet_stacked_data *psd = bio->bi_private;
2338         struct pktcdvd_device *pd = psd->pd;
2339
2340         psd->bio->bi_status = bio->bi_status;
2341         bio_put(bio);
2342         bio_endio(psd->bio);
2343         mempool_free(psd, &psd_pool);
2344         pkt_bio_finished(pd);
2345 }
2346
2347 static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
2348 {
2349         struct bio *cloned_bio =
2350                 bio_alloc_clone(pd->bdev, bio, GFP_NOIO, &pkt_bio_set);
2351         struct packet_stacked_data *psd = mempool_alloc(&psd_pool, GFP_NOIO);
2352
2353         psd->pd = pd;
2354         psd->bio = bio;
2355         cloned_bio->bi_private = psd;
2356         cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2357         pd->stats.secs_r += bio_sectors(bio);
2358         pkt_queue_bio(pd, cloned_bio);
2359 }
2360
2361 static void pkt_make_request_write(struct request_queue *q, struct bio *bio)
2362 {
2363         struct pktcdvd_device *pd = q->queuedata;
2364         sector_t zone;
2365         struct packet_data *pkt;
2366         int was_empty, blocked_bio;
2367         struct pkt_rb_node *node;
2368
2369         zone = get_zone(bio->bi_iter.bi_sector, pd);
2370
2371         /*
2372          * If we find a matching packet in state WAITING or READ_WAIT, we can
2373          * just append this bio to that packet.
2374          */
2375         spin_lock(&pd->cdrw.active_list_lock);
2376         blocked_bio = 0;
2377         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2378                 if (pkt->sector == zone) {
2379                         spin_lock(&pkt->lock);
2380                         if ((pkt->state == PACKET_WAITING_STATE) ||
2381                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2382                                 bio_list_add(&pkt->orig_bios, bio);
2383                                 pkt->write_size +=
2384                                         bio->bi_iter.bi_size / CD_FRAMESIZE;
2385                                 if ((pkt->write_size >= pkt->frames) &&
2386                                     (pkt->state == PACKET_WAITING_STATE)) {
2387                                         atomic_inc(&pkt->run_sm);
2388                                         wake_up(&pd->wqueue);
2389                                 }
2390                                 spin_unlock(&pkt->lock);
2391                                 spin_unlock(&pd->cdrw.active_list_lock);
2392                                 return;
2393                         } else {
2394                                 blocked_bio = 1;
2395                         }
2396                         spin_unlock(&pkt->lock);
2397                 }
2398         }
2399         spin_unlock(&pd->cdrw.active_list_lock);
2400
2401         /*
2402          * Test if there is enough room left in the bio work queue
2403          * (queue size >= congestion on mark).
2404          * If not, wait till the work queue size is below the congestion off mark.
2405          */
2406         spin_lock(&pd->lock);
2407         if (pd->write_congestion_on > 0
2408             && pd->bio_queue_size >= pd->write_congestion_on) {
2409                 struct wait_bit_queue_entry wqe;
2410
2411                 init_wait_var_entry(&wqe, &pd->congested, 0);
2412                 for (;;) {
2413                         prepare_to_wait_event(__var_waitqueue(&pd->congested),
2414                                               &wqe.wq_entry,
2415                                               TASK_UNINTERRUPTIBLE);
2416                         if (pd->bio_queue_size <= pd->write_congestion_off)
2417                                 break;
2418                         pd->congested = true;
2419                         spin_unlock(&pd->lock);
2420                         schedule();
2421                         spin_lock(&pd->lock);
2422                 }
2423         }
2424         spin_unlock(&pd->lock);
2425
2426         /*
2427          * No matching packet found. Store the bio in the work queue.
2428          */
2429         node = mempool_alloc(&pd->rb_pool, GFP_NOIO);
2430         node->bio = bio;
2431         spin_lock(&pd->lock);
2432         BUG_ON(pd->bio_queue_size < 0);
2433         was_empty = (pd->bio_queue_size == 0);
2434         pkt_rbtree_insert(pd, node);
2435         spin_unlock(&pd->lock);
2436
2437         /*
2438          * Wake up the worker thread.
2439          */
2440         atomic_set(&pd->scan_queue, 1);
2441         if (was_empty) {
2442                 /* This wake_up is required for correct operation */
2443                 wake_up(&pd->wqueue);
2444         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2445                 /*
2446                  * This wake up is not required for correct operation,
2447                  * but improves performance in some cases.
2448                  */
2449                 wake_up(&pd->wqueue);
2450         }
2451 }
2452
2453 static void pkt_submit_bio(struct bio *bio)
2454 {
2455         struct pktcdvd_device *pd = bio->bi_bdev->bd_disk->queue->queuedata;
2456         struct device *ddev = disk_to_dev(pd->disk);
2457         struct bio *split;
2458
2459         bio = bio_split_to_limits(bio);
2460         if (!bio)
2461                 return;
2462
2463         dev_dbg(ddev, "start = %6llx stop = %6llx\n",
2464                 (unsigned long long)bio->bi_iter.bi_sector,
2465                 (unsigned long long)bio_end_sector(bio));
2466
2467         /*
2468          * Clone READ bios so we can have our own bi_end_io callback.
2469          */
2470         if (bio_data_dir(bio) == READ) {
2471                 pkt_make_request_read(pd, bio);
2472                 return;
2473         }
2474
2475         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2476                 dev_notice(ddev, "WRITE for ro device (%llu)\n",
2477                            (unsigned long long)bio->bi_iter.bi_sector);
2478                 goto end_io;
2479         }
2480
2481         if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2482                 dev_err(ddev, "wrong bio size\n");
2483                 goto end_io;
2484         }
2485
2486         do {
2487                 sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
2488                 sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2489
2490                 if (last_zone != zone) {
2491                         BUG_ON(last_zone != zone + pd->settings.size);
2492
2493                         split = bio_split(bio, last_zone -
2494                                           bio->bi_iter.bi_sector,
2495                                           GFP_NOIO, &pkt_bio_set);
2496                         bio_chain(split, bio);
2497                 } else {
2498                         split = bio;
2499                 }
2500
2501                 pkt_make_request_write(bio->bi_bdev->bd_disk->queue, split);
2502         } while (split != bio);
2503
2504         return;
2505 end_io:
2506         bio_io_error(bio);
2507 }
2508
2509 static void pkt_init_queue(struct pktcdvd_device *pd)
2510 {
2511         struct request_queue *q = pd->disk->queue;
2512
2513         blk_queue_logical_block_size(q, CD_FRAMESIZE);
2514         blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2515         q->queuedata = pd;
2516 }
2517
2518 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2519 {
2520         struct device *ddev = disk_to_dev(pd->disk);
2521         int i;
2522         struct block_device *bdev;
2523         struct scsi_device *sdev;
2524
2525         if (pd->pkt_dev == dev) {
2526                 dev_err(ddev, "recursive setup not allowed\n");
2527                 return -EBUSY;
2528         }
2529         for (i = 0; i < MAX_WRITERS; i++) {
2530                 struct pktcdvd_device *pd2 = pkt_devs[i];
2531                 if (!pd2)
2532                         continue;
2533                 if (pd2->bdev->bd_dev == dev) {
2534                         dev_err(ddev, "%pg already setup\n", pd2->bdev);
2535                         return -EBUSY;
2536                 }
2537                 if (pd2->pkt_dev == dev) {
2538                         dev_err(ddev, "can't chain pktcdvd devices\n");
2539                         return -EBUSY;
2540                 }
2541         }
2542
2543         bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_NDELAY, NULL, NULL);
2544         if (IS_ERR(bdev))
2545                 return PTR_ERR(bdev);
2546         sdev = scsi_device_from_queue(bdev->bd_disk->queue);
2547         if (!sdev) {
2548                 blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2549                 return -EINVAL;
2550         }
2551         put_device(&sdev->sdev_gendev);
2552
2553         /* This is safe, since we have a reference from open(). */
2554         __module_get(THIS_MODULE);
2555
2556         pd->bdev = bdev;
2557         set_blocksize(bdev, CD_FRAMESIZE);
2558
2559         pkt_init_queue(pd);
2560
2561         atomic_set(&pd->cdrw.pending_bios, 0);
2562         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->disk->disk_name);
2563         if (IS_ERR(pd->cdrw.thread)) {
2564                 dev_err(ddev, "can't start kernel thread\n");
2565                 goto out_mem;
2566         }
2567
2568         proc_create_single_data(pd->disk->disk_name, 0, pkt_proc, pkt_seq_show, pd);
2569         dev_notice(ddev, "writer mapped to %pg\n", bdev);
2570         return 0;
2571
2572 out_mem:
2573         blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2574         /* This is safe: open() is still holding a reference. */
2575         module_put(THIS_MODULE);
2576         return -ENOMEM;
2577 }
2578
2579 static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2580 {
2581         struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2582         struct device *ddev = disk_to_dev(pd->disk);
2583         int ret;
2584
2585         dev_dbg(ddev, "cmd %x, dev %d:%d\n", cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2586
2587         mutex_lock(&pktcdvd_mutex);
2588         switch (cmd) {
2589         case CDROMEJECT:
2590                 /*
2591                  * The door gets locked when the device is opened, so we
2592                  * have to unlock it or else the eject command fails.
2593                  */
2594                 if (pd->refcnt == 1)
2595                         pkt_lock_door(pd, 0);
2596                 fallthrough;
2597         /*
2598          * forward selected CDROM ioctls to CD-ROM, for UDF
2599          */
2600         case CDROMMULTISESSION:
2601         case CDROMREADTOCENTRY:
2602         case CDROM_LAST_WRITTEN:
2603         case CDROM_SEND_PACKET:
2604         case SCSI_IOCTL_SEND_COMMAND:
2605                 if (!bdev->bd_disk->fops->ioctl)
2606                         ret = -ENOTTY;
2607                 else
2608                         ret = bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
2609                 break;
2610         default:
2611                 dev_dbg(ddev, "Unknown ioctl (%x)\n", cmd);
2612                 ret = -ENOTTY;
2613         }
2614         mutex_unlock(&pktcdvd_mutex);
2615
2616         return ret;
2617 }
2618
2619 static unsigned int pkt_check_events(struct gendisk *disk,
2620                                      unsigned int clearing)
2621 {
2622         struct pktcdvd_device *pd = disk->private_data;
2623         struct gendisk *attached_disk;
2624
2625         if (!pd)
2626                 return 0;
2627         if (!pd->bdev)
2628                 return 0;
2629         attached_disk = pd->bdev->bd_disk;
2630         if (!attached_disk || !attached_disk->fops->check_events)
2631                 return 0;
2632         return attached_disk->fops->check_events(attached_disk, clearing);
2633 }
2634
2635 static char *pkt_devnode(struct gendisk *disk, umode_t *mode)
2636 {
2637         return kasprintf(GFP_KERNEL, "pktcdvd/%s", disk->disk_name);
2638 }
2639
2640 static const struct block_device_operations pktcdvd_ops = {
2641         .owner =                THIS_MODULE,
2642         .submit_bio =           pkt_submit_bio,
2643         .open =                 pkt_open,
2644         .release =              pkt_close,
2645         .ioctl =                pkt_ioctl,
2646         .compat_ioctl =         blkdev_compat_ptr_ioctl,
2647         .check_events =         pkt_check_events,
2648         .devnode =              pkt_devnode,
2649 };
2650
2651 /*
2652  * Set up mapping from pktcdvd device to CD-ROM device.
2653  */
2654 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2655 {
2656         int idx;
2657         int ret = -ENOMEM;
2658         struct pktcdvd_device *pd;
2659         struct gendisk *disk;
2660
2661         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2662
2663         for (idx = 0; idx < MAX_WRITERS; idx++)
2664                 if (!pkt_devs[idx])
2665                         break;
2666         if (idx == MAX_WRITERS) {
2667                 pr_err("max %d writers supported\n", MAX_WRITERS);
2668                 ret = -EBUSY;
2669                 goto out_mutex;
2670         }
2671
2672         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2673         if (!pd)
2674                 goto out_mutex;
2675
2676         ret = mempool_init_kmalloc_pool(&pd->rb_pool, PKT_RB_POOL_SIZE,
2677                                         sizeof(struct pkt_rb_node));
2678         if (ret)
2679                 goto out_mem;
2680
2681         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2682         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2683         spin_lock_init(&pd->cdrw.active_list_lock);
2684
2685         spin_lock_init(&pd->lock);
2686         spin_lock_init(&pd->iosched.lock);
2687         bio_list_init(&pd->iosched.read_queue);
2688         bio_list_init(&pd->iosched.write_queue);
2689         init_waitqueue_head(&pd->wqueue);
2690         pd->bio_queue = RB_ROOT;
2691
2692         pd->write_congestion_on  = write_congestion_on;
2693         pd->write_congestion_off = write_congestion_off;
2694
2695         ret = -ENOMEM;
2696         disk = blk_alloc_disk(NUMA_NO_NODE);
2697         if (!disk)
2698                 goto out_mem;
2699         pd->disk = disk;
2700         disk->major = pktdev_major;
2701         disk->first_minor = idx;
2702         disk->minors = 1;
2703         disk->fops = &pktcdvd_ops;
2704         disk->flags = GENHD_FL_REMOVABLE | GENHD_FL_NO_PART;
2705         snprintf(disk->disk_name, sizeof(disk->disk_name), DRIVER_NAME"%d", idx);
2706         disk->private_data = pd;
2707
2708         pd->pkt_dev = MKDEV(pktdev_major, idx);
2709         ret = pkt_new_dev(pd, dev);
2710         if (ret)
2711                 goto out_mem2;
2712
2713         /* inherit events of the host device */
2714         disk->events = pd->bdev->bd_disk->events;
2715
2716         ret = add_disk(disk);
2717         if (ret)
2718                 goto out_mem2;
2719
2720         pkt_sysfs_dev_new(pd);
2721         pkt_debugfs_dev_new(pd);
2722
2723         pkt_devs[idx] = pd;
2724         if (pkt_dev)
2725                 *pkt_dev = pd->pkt_dev;
2726
2727         mutex_unlock(&ctl_mutex);
2728         return 0;
2729
2730 out_mem2:
2731         put_disk(disk);
2732 out_mem:
2733         mempool_exit(&pd->rb_pool);
2734         kfree(pd);
2735 out_mutex:
2736         mutex_unlock(&ctl_mutex);
2737         pr_err("setup of pktcdvd device failed\n");
2738         return ret;
2739 }
2740
2741 /*
2742  * Tear down mapping from pktcdvd device to CD-ROM device.
2743  */
2744 static int pkt_remove_dev(dev_t pkt_dev)
2745 {
2746         struct pktcdvd_device *pd;
2747         struct device *ddev;
2748         int idx;
2749         int ret = 0;
2750
2751         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2752
2753         for (idx = 0; idx < MAX_WRITERS; idx++) {
2754                 pd = pkt_devs[idx];
2755                 if (pd && (pd->pkt_dev == pkt_dev))
2756                         break;
2757         }
2758         if (idx == MAX_WRITERS) {
2759                 pr_debug("dev not setup\n");
2760                 ret = -ENXIO;
2761                 goto out;
2762         }
2763
2764         if (pd->refcnt > 0) {
2765                 ret = -EBUSY;
2766                 goto out;
2767         }
2768
2769         ddev = disk_to_dev(pd->disk);
2770
2771         if (!IS_ERR(pd->cdrw.thread))
2772                 kthread_stop(pd->cdrw.thread);
2773
2774         pkt_devs[idx] = NULL;
2775
2776         pkt_debugfs_dev_remove(pd);
2777         pkt_sysfs_dev_remove(pd);
2778
2779         blkdev_put(pd->bdev, FMODE_READ | FMODE_NDELAY);
2780
2781         remove_proc_entry(pd->disk->disk_name, pkt_proc);
2782         dev_notice(ddev, "writer unmapped\n");
2783
2784         del_gendisk(pd->disk);
2785         put_disk(pd->disk);
2786
2787         mempool_exit(&pd->rb_pool);
2788         kfree(pd);
2789
2790         /* This is safe: open() is still holding a reference. */
2791         module_put(THIS_MODULE);
2792
2793 out:
2794         mutex_unlock(&ctl_mutex);
2795         return ret;
2796 }
2797
2798 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2799 {
2800         struct pktcdvd_device *pd;
2801
2802         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2803
2804         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2805         if (pd) {
2806                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2807                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2808         } else {
2809                 ctrl_cmd->dev = 0;
2810                 ctrl_cmd->pkt_dev = 0;
2811         }
2812         ctrl_cmd->num_devices = MAX_WRITERS;
2813
2814         mutex_unlock(&ctl_mutex);
2815 }
2816
2817 static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2818 {
2819         void __user *argp = (void __user *)arg;
2820         struct pkt_ctrl_command ctrl_cmd;
2821         int ret = 0;
2822         dev_t pkt_dev = 0;
2823
2824         if (cmd != PACKET_CTRL_CMD)
2825                 return -ENOTTY;
2826
2827         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2828                 return -EFAULT;
2829
2830         switch (ctrl_cmd.command) {
2831         case PKT_CTRL_CMD_SETUP:
2832                 if (!capable(CAP_SYS_ADMIN))
2833                         return -EPERM;
2834                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2835                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2836                 break;
2837         case PKT_CTRL_CMD_TEARDOWN:
2838                 if (!capable(CAP_SYS_ADMIN))
2839                         return -EPERM;
2840                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2841                 break;
2842         case PKT_CTRL_CMD_STATUS:
2843                 pkt_get_status(&ctrl_cmd);
2844                 break;
2845         default:
2846                 return -ENOTTY;
2847         }
2848
2849         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2850                 return -EFAULT;
2851         return ret;
2852 }
2853
2854 #ifdef CONFIG_COMPAT
2855 static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2856 {
2857         return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2858 }
2859 #endif
2860
2861 static const struct file_operations pkt_ctl_fops = {
2862         .open           = nonseekable_open,
2863         .unlocked_ioctl = pkt_ctl_ioctl,
2864 #ifdef CONFIG_COMPAT
2865         .compat_ioctl   = pkt_ctl_compat_ioctl,
2866 #endif
2867         .owner          = THIS_MODULE,
2868         .llseek         = no_llseek,
2869 };
2870
2871 static struct miscdevice pkt_misc = {
2872         .minor          = MISC_DYNAMIC_MINOR,
2873         .name           = DRIVER_NAME,
2874         .nodename       = "pktcdvd/control",
2875         .fops           = &pkt_ctl_fops
2876 };
2877
2878 static int __init pkt_init(void)
2879 {
2880         int ret;
2881
2882         mutex_init(&ctl_mutex);
2883
2884         ret = mempool_init_kmalloc_pool(&psd_pool, PSD_POOL_SIZE,
2885                                     sizeof(struct packet_stacked_data));
2886         if (ret)
2887                 return ret;
2888         ret = bioset_init(&pkt_bio_set, BIO_POOL_SIZE, 0, 0);
2889         if (ret) {
2890                 mempool_exit(&psd_pool);
2891                 return ret;
2892         }
2893
2894         ret = register_blkdev(pktdev_major, DRIVER_NAME);
2895         if (ret < 0) {
2896                 pr_err("unable to register block device\n");
2897                 goto out2;
2898         }
2899         if (!pktdev_major)
2900                 pktdev_major = ret;
2901
2902         ret = pkt_sysfs_init();
2903         if (ret)
2904                 goto out;
2905
2906         pkt_debugfs_init();
2907
2908         ret = misc_register(&pkt_misc);
2909         if (ret) {
2910                 pr_err("unable to register misc device\n");
2911                 goto out_misc;
2912         }
2913
2914         pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
2915
2916         return 0;
2917
2918 out_misc:
2919         pkt_debugfs_cleanup();
2920         pkt_sysfs_cleanup();
2921 out:
2922         unregister_blkdev(pktdev_major, DRIVER_NAME);
2923 out2:
2924         mempool_exit(&psd_pool);
2925         bioset_exit(&pkt_bio_set);
2926         return ret;
2927 }
2928
2929 static void __exit pkt_exit(void)
2930 {
2931         remove_proc_entry("driver/"DRIVER_NAME, NULL);
2932         misc_deregister(&pkt_misc);
2933
2934         pkt_debugfs_cleanup();
2935         pkt_sysfs_cleanup();
2936
2937         unregister_blkdev(pktdev_major, DRIVER_NAME);
2938         mempool_exit(&psd_pool);
2939         bioset_exit(&pkt_bio_set);
2940 }
2941
2942 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
2943 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
2944 MODULE_LICENSE("GPL");
2945
2946 module_init(pkt_init);
2947 module_exit(pkt_exit);