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/backing-dev.h>
  50 #include <linux/compat.h>
  51 #include <linux/debugfs.h>
  52 #include <linux/device.h>
  53 #include <linux/errno.h>
  54 #include <linux/file.h>
  55 #include <linux/freezer.h>
  56 #include <linux/kernel.h>
  57 #include <linux/kthread.h>
  58 #include <linux/miscdevice.h>
  59 #include <linux/module.h>
  60 #include <linux/mutex.h>
  61 #include <linux/nospec.h>
  62 #include <linux/pktcdvd.h>
  63 #include <linux/proc_fs.h>
  64 #include <linux/seq_file.h>
  65 #include <linux/slab.h>
  66 #include <linux/spinlock.h>
  67 #include <linux/types.h>
  68 #include <linux/uaccess.h>
  69
  70 #include <scsi/scsi.h>
  71 #include <scsi/scsi_cmnd.h>
  72 #include <scsi/scsi_ioctl.h>
  73
  74 #include <asm/unaligned.h>
  75
  76 #define DRIVER_NAME     "pktcdvd"
  77
  78 #define MAX_SPEED 0xffff
  79
  80 static DEFINE_MUTEX(pktcdvd_mutex);
  81 static struct pktcdvd_device *pkt_devs[MAX_WRITERS];
  82 static struct proc_dir_entry *pkt_proc;
  83 static int pktdev_major;
  84 static int write_congestion_on  = PKT_WRITE_CONGESTION_ON;
  85 static int write_congestion_off = PKT_WRITE_CONGESTION_OFF;
  86 static struct mutex ctl_mutex;  /* Serialize open/close/setup/teardown */
  87 static mempool_t psd_pool;
  88 static struct bio_set pkt_bio_set;
  89
  90 /* /sys/class/pktcdvd */
  91 static struct class     class_pktcdvd;
  92 static struct dentry    *pkt_debugfs_root = NULL; /* /sys/kernel/debug/pktcdvd */
  93
  94 /* forward declaration */
  95 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev);
  96 static int pkt_remove_dev(dev_t pkt_dev);
  97
  98 static sector_t get_zone(sector_t sector, struct pktcdvd_device *pd)
  99 {
 100         return (sector + pd->offset) & ~(sector_t)(pd->settings.size - 1);
 101 }
 102
 103 /**********************************************************
 104  * sysfs interface for pktcdvd
 105  * by (C) 2006  Thomas Maier <balagi@justmail.de>
 106
 107   /sys/class/pktcdvd/pktcdvd[0-7]/
 108                      stat/reset
 109                      stat/packets_started
 110                      stat/packets_finished
 111                      stat/kb_written
 112                      stat/kb_read
 113                      stat/kb_read_gather
 114                      write_queue/size
 115                      write_queue/congestion_off
 116                      write_queue/congestion_on
 117  **********************************************************/
 118
 119 static ssize_t packets_started_show(struct device *dev,
 120                                     struct device_attribute *attr, char *buf)
 121 {
 122         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 123
 124         return sysfs_emit(buf, "%lu\n", pd->stats.pkt_started);
 125 }
 126 static DEVICE_ATTR_RO(packets_started);
 127
 128 static ssize_t packets_finished_show(struct device *dev,
 129                                      struct device_attribute *attr, char *buf)
 130 {
 131         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 132
 133         return sysfs_emit(buf, "%lu\n", pd->stats.pkt_ended);
 134 }
 135 static DEVICE_ATTR_RO(packets_finished);
 136
 137 static ssize_t kb_written_show(struct device *dev,
 138                                struct device_attribute *attr, char *buf)
 139 {
 140         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 141
 142         return sysfs_emit(buf, "%lu\n", pd->stats.secs_w >> 1);
 143 }
 144 static DEVICE_ATTR_RO(kb_written);
 145
 146 static ssize_t kb_read_show(struct device *dev,
 147                             struct device_attribute *attr, char *buf)
 148 {
 149         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 150
 151         return sysfs_emit(buf, "%lu\n", pd->stats.secs_r >> 1);
 152 }
 153 static DEVICE_ATTR_RO(kb_read);
 154
 155 static ssize_t kb_read_gather_show(struct device *dev,
 156                                    struct device_attribute *attr, char *buf)
 157 {
 158         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 159
 160         return sysfs_emit(buf, "%lu\n", pd->stats.secs_rg >> 1);
 161 }
 162 static DEVICE_ATTR_RO(kb_read_gather);
 163
 164 static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
 165                            const char *buf, size_t len)
 166 {
 167         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 168
 169         if (len > 0) {
 170                 pd->stats.pkt_started = 0;
 171                 pd->stats.pkt_ended = 0;
 172                 pd->stats.secs_w = 0;
 173                 pd->stats.secs_rg = 0;
 174                 pd->stats.secs_r = 0;
 175         }
 176         return len;
 177 }
 178 static DEVICE_ATTR_WO(reset);
 179
 180 static struct attribute *pkt_stat_attrs[] = {
 181         &dev_attr_packets_finished.attr,
 182         &dev_attr_packets_started.attr,
 183         &dev_attr_kb_read.attr,
 184         &dev_attr_kb_written.attr,
 185         &dev_attr_kb_read_gather.attr,
 186         &dev_attr_reset.attr,
 187         NULL,
 188 };
 189
 190 static const struct attribute_group pkt_stat_group = {
 191         .name = "stat",
 192         .attrs = pkt_stat_attrs,
 193 };
 194
 195 static ssize_t size_show(struct device *dev,
 196                          struct device_attribute *attr, char *buf)
 197 {
 198         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 199         int n;
 200
 201         spin_lock(&pd->lock);
 202         n = sysfs_emit(buf, "%d\n", pd->bio_queue_size);
 203         spin_unlock(&pd->lock);
 204         return n;
 205 }
 206 static DEVICE_ATTR_RO(size);
 207
 208 static void init_write_congestion_marks(int* lo, int* hi)
 209 {
 210         if (*hi > 0) {
 211                 *hi = max(*hi, 500);
 212                 *hi = min(*hi, 1000000);
 213                 if (*lo <= 0)
 214                         *lo = *hi - 100;
 215                 else {
 216                         *lo = min(*lo, *hi - 100);
 217                         *lo = max(*lo, 100);
 218                 }
 219         } else {
 220                 *hi = -1;
 221                 *lo = -1;
 222         }
 223 }
 224
 225 static ssize_t congestion_off_show(struct device *dev,
 226                                    struct device_attribute *attr, char *buf)
 227 {
 228         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 229         int n;
 230
 231         spin_lock(&pd->lock);
 232         n = sysfs_emit(buf, "%d\n", pd->write_congestion_off);
 233         spin_unlock(&pd->lock);
 234         return n;
 235 }
 236
 237 static ssize_t congestion_off_store(struct device *dev,
 238                                     struct device_attribute *attr,
 239                                     const char *buf, size_t len)
 240 {
 241         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 242         int val, ret;
 243
 244         ret = kstrtoint(buf, 10, &val);
 245         if (ret)
 246                 return ret;
 247
 248         spin_lock(&pd->lock);
 249         pd->write_congestion_off = val;
 250         init_write_congestion_marks(&pd->write_congestion_off, &pd->write_congestion_on);
 251         spin_unlock(&pd->lock);
 252         return len;
 253 }
 254 static DEVICE_ATTR_RW(congestion_off);
 255
 256 static ssize_t congestion_on_show(struct device *dev,
 257                                   struct device_attribute *attr, char *buf)
 258 {
 259         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 260         int n;
 261
 262         spin_lock(&pd->lock);
 263         n = sysfs_emit(buf, "%d\n", pd->write_congestion_on);
 264         spin_unlock(&pd->lock);
 265         return n;
 266 }
 267
 268 static ssize_t congestion_on_store(struct device *dev,
 269                                    struct device_attribute *attr,
 270                                    const char *buf, size_t len)
 271 {
 272         struct pktcdvd_device *pd = dev_get_drvdata(dev);
 273         int val, ret;
 274
 275         ret = kstrtoint(buf, 10, &val);
 276         if (ret)
 277                 return ret;
 278
 279         spin_lock(&pd->lock);
 280         pd->write_congestion_on = val;
 281         init_write_congestion_marks(&pd->write_congestion_off, &pd->write_congestion_on);
 282         spin_unlock(&pd->lock);
 283         return len;
 284 }
 285 static DEVICE_ATTR_RW(congestion_on);
 286
 287 static struct attribute *pkt_wq_attrs[] = {
 288         &dev_attr_congestion_on.attr,
 289         &dev_attr_congestion_off.attr,
 290         &dev_attr_size.attr,
 291         NULL,
 292 };
 293
 294 static const struct attribute_group pkt_wq_group = {
 295         .name = "write_queue",
 296         .attrs = pkt_wq_attrs,
 297 };
 298
 299 static const struct attribute_group *pkt_groups[] = {
 300         &pkt_stat_group,
 301         &pkt_wq_group,
 302         NULL,
 303 };
 304
 305 static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
 306 {
 307         if (class_is_registered(&class_pktcdvd)) {
 308                 pd->dev = device_create_with_groups(&class_pktcdvd, NULL,
 309                                                     MKDEV(0, 0), pd, pkt_groups,
 310                                                     "%s", pd->disk->disk_name);
 311                 if (IS_ERR(pd->dev))
 312                         pd->dev = NULL;
 313         }
 314 }
 315
 316 static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
 317 {
 318         if (class_is_registered(&class_pktcdvd))
 319                 device_unregister(pd->dev);
 320 }
 321
 322
 323 /********************************************************************
 324   /sys/class/pktcdvd/
 325                      add            map block device
 326                      remove         unmap packet dev
 327                      device_map     show mappings
 328  *******************************************************************/
 329
 330 static ssize_t device_map_show(const struct class *c, const struct class_attribute *attr,
 331                                char *data)
 332 {
 333         int n = 0;
 334         int idx;
 335         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
 336         for (idx = 0; idx < MAX_WRITERS; idx++) {
 337                 struct pktcdvd_device *pd = pkt_devs[idx];
 338                 if (!pd)
 339                         continue;
 340                 n += sysfs_emit_at(data, n, "%s %u:%u %u:%u\n",
 341                         pd->disk->disk_name,
 342                         MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
 343                         MAJOR(pd->bdev->bd_dev),
 344                         MINOR(pd->bdev->bd_dev));
 345         }
 346         mutex_unlock(&ctl_mutex);
 347         return n;
 348 }
 349 static CLASS_ATTR_RO(device_map);
 350
 351 static ssize_t add_store(const struct class *c, const struct class_attribute *attr,
 352                          const char *buf, size_t count)
 353 {
 354         unsigned int major, minor;
 355
 356         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 357                 /* pkt_setup_dev() expects caller to hold reference to self */
 358                 if (!try_module_get(THIS_MODULE))
 359                         return -ENODEV;
 360
 361                 pkt_setup_dev(MKDEV(major, minor), NULL);
 362
 363                 module_put(THIS_MODULE);
 364
 365                 return count;
 366         }
 367
 368         return -EINVAL;
 369 }
 370 static CLASS_ATTR_WO(add);
 371
 372 static ssize_t remove_store(const struct class *c, const struct class_attribute *attr,
 373                             const char *buf, size_t count)
 374 {
 375         unsigned int major, minor;
 376         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 377                 pkt_remove_dev(MKDEV(major, minor));
 378                 return count;
 379         }
 380         return -EINVAL;
 381 }
 382 static CLASS_ATTR_WO(remove);
 383
 384 static struct attribute *class_pktcdvd_attrs[] = {
 385         &class_attr_add.attr,
 386         &class_attr_remove.attr,
 387         &class_attr_device_map.attr,
 388         NULL,
 389 };
 390 ATTRIBUTE_GROUPS(class_pktcdvd);
 391
 392 static struct class class_pktcdvd = {
 393         .name           = DRIVER_NAME,
 394         .class_groups   = class_pktcdvd_groups,
 395 };
 396
 397 static int pkt_sysfs_init(void)
 398 {
 399         /*
 400          * create control files in sysfs
 401          * /sys/class/pktcdvd/...
 402          */
 403         return class_register(&class_pktcdvd);
 404 }
 405
 406 static void pkt_sysfs_cleanup(void)
 407 {
 408         class_unregister(&class_pktcdvd);
 409 }
 410
 411 /********************************************************************
 412   entries in debugfs
 413
 414   /sys/kernel/debug/pktcdvd[0-7]/
 415                         info
 416
 417  *******************************************************************/
 418
 419 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
 420 {
 421         struct packet_data *pkt;
 422         int i;
 423
 424         for (i = 0; i < PACKET_NUM_STATES; i++)
 425                 states[i] = 0;
 426
 427         spin_lock(&pd->cdrw.active_list_lock);
 428         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
 429                 states[pkt->state]++;
 430         }
 431         spin_unlock(&pd->cdrw.active_list_lock);
 432 }
 433
 434 static int pkt_seq_show(struct seq_file *m, void *p)
 435 {
 436         struct pktcdvd_device *pd = m->private;
 437         char *msg;
 438         int states[PACKET_NUM_STATES];
 439
 440         seq_printf(m, "Writer %s mapped to %pg:\n", pd->disk->disk_name, pd->bdev);
 441
 442         seq_printf(m, "\nSettings:\n");
 443         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
 444
 445         if (pd->settings.write_type == 0)
 446                 msg = "Packet";
 447         else
 448                 msg = "Unknown";
 449         seq_printf(m, "\twrite type:\t\t%s\n", msg);
 450
 451         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
 452         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
 453
 454         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
 455
 456         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
 457                 msg = "Mode 1";
 458         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
 459                 msg = "Mode 2";
 460         else
 461                 msg = "Unknown";
 462         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
 463
 464         seq_printf(m, "\nStatistics:\n");
 465         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
 466         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
 467         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
 468         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
 469         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
 470
 471         seq_printf(m, "\nMisc:\n");
 472         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
 473         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
 474         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
 475         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
 476         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
 477         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
 478
 479         seq_printf(m, "\nQueue state:\n");
 480         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
 481         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
 482         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", pd->current_sector);
 483
 484         pkt_count_states(pd, states);
 485         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
 486                    states[0], states[1], states[2], states[3], states[4], states[5]);
 487
 488         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
 489                         pd->write_congestion_off,
 490                         pd->write_congestion_on);
 491         return 0;
 492 }
 493 DEFINE_SHOW_ATTRIBUTE(pkt_seq);
 494
 495 static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
 496 {
 497         if (!pkt_debugfs_root)
 498                 return;
 499         pd->dfs_d_root = debugfs_create_dir(pd->disk->disk_name, pkt_debugfs_root);
 500         if (!pd->dfs_d_root)
 501                 return;
 502
 503         pd->dfs_f_info = debugfs_create_file("info", 0444, pd->dfs_d_root,
 504                                              pd, &pkt_seq_fops);
 505 }
 506
 507 static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
 508 {
 509         if (!pkt_debugfs_root)
 510                 return;
 511         debugfs_remove(pd->dfs_f_info);
 512         debugfs_remove(pd->dfs_d_root);
 513         pd->dfs_f_info = NULL;
 514         pd->dfs_d_root = NULL;
 515 }
 516
 517 static void pkt_debugfs_init(void)
 518 {
 519         pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
 520 }
 521
 522 static void pkt_debugfs_cleanup(void)
 523 {
 524         debugfs_remove(pkt_debugfs_root);
 525         pkt_debugfs_root = NULL;
 526 }
 527
 528 /* ----------------------------------------------------------*/
 529
 530
 531 static void pkt_bio_finished(struct pktcdvd_device *pd)
 532 {
 533         struct device *ddev = disk_to_dev(pd->disk);
 534
 535         BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
 536         if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
 537                 dev_dbg(ddev, "queue empty\n");
 538                 atomic_set(&pd->iosched.attention, 1);
 539                 wake_up(&pd->wqueue);
 540         }
 541 }
 542
 543 /*
 544  * Allocate a packet_data struct
 545  */
 546 static struct packet_data *pkt_alloc_packet_data(int frames)
 547 {
 548         int i;
 549         struct packet_data *pkt;
 550
 551         pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
 552         if (!pkt)
 553                 goto no_pkt;
 554
 555         pkt->frames = frames;
 556         pkt->w_bio = bio_kmalloc(frames, GFP_KERNEL);
 557         if (!pkt->w_bio)
 558                 goto no_bio;
 559
 560         for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
 561                 pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
 562                 if (!pkt->pages[i])
 563                         goto no_page;
 564         }
 565
 566         spin_lock_init(&pkt->lock);
 567         bio_list_init(&pkt->orig_bios);
 568
 569         for (i = 0; i < frames; i++) {
 570                 pkt->r_bios[i] = bio_kmalloc(1, GFP_KERNEL);
 571                 if (!pkt->r_bios[i])
 572                         goto no_rd_bio;
 573         }
 574
 575         return pkt;
 576
 577 no_rd_bio:
 578         for (i = 0; i < frames; i++)
 579                 kfree(pkt->r_bios[i]);
 580 no_page:
 581         for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
 582                 if (pkt->pages[i])
 583                         __free_page(pkt->pages[i]);
 584         kfree(pkt->w_bio);
 585 no_bio:
 586         kfree(pkt);
 587 no_pkt:
 588         return NULL;
 589 }
 590
 591 /*
 592  * Free a packet_data struct
 593  */
 594 static void pkt_free_packet_data(struct packet_data *pkt)
 595 {
 596         int i;
 597
 598         for (i = 0; i < pkt->frames; i++)
 599                 kfree(pkt->r_bios[i]);
 600         for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
 601                 __free_page(pkt->pages[i]);
 602         kfree(pkt->w_bio);
 603         kfree(pkt);
 604 }
 605
 606 static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
 607 {
 608         struct packet_data *pkt, *next;
 609
 610         BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
 611
 612         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
 613                 pkt_free_packet_data(pkt);
 614         }
 615         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
 616 }
 617
 618 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
 619 {
 620         struct packet_data *pkt;
 621
 622         BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
 623
 624         while (nr_packets > 0) {
 625                 pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
 626                 if (!pkt) {
 627                         pkt_shrink_pktlist(pd);
 628                         return 0;
 629                 }
 630                 pkt->id = nr_packets;
 631                 pkt->pd = pd;
 632                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
 633                 nr_packets--;
 634         }
 635         return 1;
 636 }
 637
 638 static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
 639 {
 640         struct rb_node *n = rb_next(&node->rb_node);
 641         if (!n)
 642                 return NULL;
 643         return rb_entry(n, struct pkt_rb_node, rb_node);
 644 }
 645
 646 static void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 647 {
 648         rb_erase(&node->rb_node, &pd->bio_queue);
 649         mempool_free(node, &pd->rb_pool);
 650         pd->bio_queue_size--;
 651         BUG_ON(pd->bio_queue_size < 0);
 652 }
 653
 654 /*
 655  * Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
 656  */
 657 static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
 658 {
 659         struct rb_node *n = pd->bio_queue.rb_node;
 660         struct rb_node *next;
 661         struct pkt_rb_node *tmp;
 662
 663         if (!n) {
 664                 BUG_ON(pd->bio_queue_size > 0);
 665                 return NULL;
 666         }
 667
 668         for (;;) {
 669                 tmp = rb_entry(n, struct pkt_rb_node, rb_node);
 670                 if (s <= tmp->bio->bi_iter.bi_sector)
 671                         next = n->rb_left;
 672                 else
 673                         next = n->rb_right;
 674                 if (!next)
 675                         break;
 676                 n = next;
 677         }
 678
 679         if (s > tmp->bio->bi_iter.bi_sector) {
 680                 tmp = pkt_rbtree_next(tmp);
 681                 if (!tmp)
 682                         return NULL;
 683         }
 684         BUG_ON(s > tmp->bio->bi_iter.bi_sector);
 685         return tmp;
 686 }
 687
 688 /*
 689  * Insert a node into the pd->bio_queue rb tree.
 690  */
 691 static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 692 {
 693         struct rb_node **p = &pd->bio_queue.rb_node;
 694         struct rb_node *parent = NULL;
 695         sector_t s = node->bio->bi_iter.bi_sector;
 696         struct pkt_rb_node *tmp;
 697
 698         while (*p) {
 699                 parent = *p;
 700                 tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
 701                 if (s < tmp->bio->bi_iter.bi_sector)
 702                         p = &(*p)->rb_left;
 703                 else
 704                         p = &(*p)->rb_right;
 705         }
 706         rb_link_node(&node->rb_node, parent, p);
 707         rb_insert_color(&node->rb_node, &pd->bio_queue);
 708         pd->bio_queue_size++;
 709 }
 710
 711 /*
 712  * Send a packet_command to the underlying block device and
 713  * wait for completion.
 714  */
 715 static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
 716 {
 717         struct request_queue *q = bdev_get_queue(pd->bdev);
 718         struct scsi_cmnd *scmd;
 719         struct request *rq;
 720         int ret = 0;
 721
 722         rq = scsi_alloc_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
 723                              REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 724         if (IS_ERR(rq))
 725                 return PTR_ERR(rq);
 726         scmd = blk_mq_rq_to_pdu(rq);
 727
 728         if (cgc->buflen) {
 729                 ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
 730                                       GFP_NOIO);
 731                 if (ret)
 732                         goto out;
 733         }
 734
 735         scmd->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
 736         memcpy(scmd->cmnd, cgc->cmd, CDROM_PACKET_SIZE);
 737
 738         rq->timeout = 60*HZ;
 739         if (cgc->quiet)
 740                 rq->rq_flags |= RQF_QUIET;
 741
 742         blk_execute_rq(rq, false);
 743         if (scmd->result)
 744                 ret = -EIO;
 745 out:
 746         blk_mq_free_request(rq);
 747         return ret;
 748 }
 749
 750 static const char *sense_key_string(__u8 index)
 751 {
 752         static const char * const info[] = {
 753                 "No sense", "Recovered error", "Not ready",
 754                 "Medium error", "Hardware error", "Illegal request",
 755                 "Unit attention", "Data protect", "Blank check",
 756         };
 757
 758         return index < ARRAY_SIZE(info) ? info[index] : "INVALID";
 759 }
 760
 761 /*
 762  * A generic sense dump / resolve mechanism should be implemented across
 763  * all ATAPI + SCSI devices.
 764  */
 765 static void pkt_dump_sense(struct pktcdvd_device *pd,
 766                            struct packet_command *cgc)
 767 {
 768         struct device *ddev = disk_to_dev(pd->disk);
 769         struct scsi_sense_hdr *sshdr = cgc->sshdr;
 770
 771         if (sshdr)
 772                 dev_err(ddev, "%*ph - sense %02x.%02x.%02x (%s)\n",
 773                         CDROM_PACKET_SIZE, cgc->cmd,
 774                         sshdr->sense_key, sshdr->asc, sshdr->ascq,
 775                         sense_key_string(sshdr->sense_key));
 776         else
 777                 dev_err(ddev, "%*ph - no sense\n", CDROM_PACKET_SIZE, cgc->cmd);
 778 }
 779
 780 /*
 781  * flush the drive cache to media
 782  */
 783 static int pkt_flush_cache(struct pktcdvd_device *pd)
 784 {
 785         struct packet_command cgc;
 786
 787         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 788         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 789         cgc.quiet = 1;
 790
 791         /*
 792          * the IMMED bit -- we default to not setting it, although that
 793          * would allow a much faster close, this is safer
 794          */
 795 #if 0
 796         cgc.cmd[1] = 1 << 1;
 797 #endif
 798         return pkt_generic_packet(pd, &cgc);
 799 }
 800
 801 /*
 802  * speed is given as the normal factor, e.g. 4 for 4x
 803  */
 804 static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
 805                                 unsigned write_speed, unsigned read_speed)
 806 {
 807         struct packet_command cgc;
 808         struct scsi_sense_hdr sshdr;
 809         int ret;
 810
 811         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 812         cgc.sshdr = &sshdr;
 813         cgc.cmd[0] = GPCMD_SET_SPEED;
 814         put_unaligned_be16(read_speed, &cgc.cmd[2]);
 815         put_unaligned_be16(write_speed, &cgc.cmd[4]);
 816
 817         ret = pkt_generic_packet(pd, &cgc);
 818         if (ret)
 819                 pkt_dump_sense(pd, &cgc);
 820
 821         return ret;
 822 }
 823
 824 /*
 825  * Queue a bio for processing by the low-level CD device. Must be called
 826  * from process context.
 827  */
 828 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 829 {
 830         spin_lock(&pd->iosched.lock);
 831         if (bio_data_dir(bio) == READ)
 832                 bio_list_add(&pd->iosched.read_queue, bio);
 833         else
 834                 bio_list_add(&pd->iosched.write_queue, bio);
 835         spin_unlock(&pd->iosched.lock);
 836
 837         atomic_set(&pd->iosched.attention, 1);
 838         wake_up(&pd->wqueue);
 839 }
 840
 841 /*
 842  * Process the queued read/write requests. This function handles special
 843  * requirements for CDRW drives:
 844  * - A cache flush command must be inserted before a read request if the
 845  *   previous request was a write.
 846  * - Switching between reading and writing is slow, so don't do it more often
 847  *   than necessary.
 848  * - Optimize for throughput at the expense of latency. This means that streaming
 849  *   writes will never be interrupted by a read, but if the drive has to seek
 850  *   before the next write, switch to reading instead if there are any pending
 851  *   read requests.
 852  * - Set the read speed according to current usage pattern. When only reading
 853  *   from the device, it's best to use the highest possible read speed, but
 854  *   when switching often between reading and writing, it's better to have the
 855  *   same read and write speeds.
 856  */
 857 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
 858 {
 859         struct device *ddev = disk_to_dev(pd->disk);
 860
 861         if (atomic_read(&pd->iosched.attention) == 0)
 862                 return;
 863         atomic_set(&pd->iosched.attention, 0);
 864
 865         for (;;) {
 866                 struct bio *bio;
 867                 int reads_queued, writes_queued;
 868
 869                 spin_lock(&pd->iosched.lock);
 870                 reads_queued = !bio_list_empty(&pd->iosched.read_queue);
 871                 writes_queued = !bio_list_empty(&pd->iosched.write_queue);
 872                 spin_unlock(&pd->iosched.lock);
 873
 874                 if (!reads_queued && !writes_queued)
 875                         break;
 876
 877                 if (pd->iosched.writing) {
 878                         int need_write_seek = 1;
 879                         spin_lock(&pd->iosched.lock);
 880                         bio = bio_list_peek(&pd->iosched.write_queue);
 881                         spin_unlock(&pd->iosched.lock);
 882                         if (bio && (bio->bi_iter.bi_sector ==
 883                                     pd->iosched.last_write))
 884                                 need_write_seek = 0;
 885                         if (need_write_seek && reads_queued) {
 886                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 887                                         dev_dbg(ddev, "write, waiting\n");
 888                                         break;
 889                                 }
 890                                 pkt_flush_cache(pd);
 891                                 pd->iosched.writing = 0;
 892                         }
 893                 } else {
 894                         if (!reads_queued && writes_queued) {
 895                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 896                                         dev_dbg(ddev, "read, waiting\n");
 897                                         break;
 898                                 }
 899                                 pd->iosched.writing = 1;
 900                         }
 901                 }
 902
 903                 spin_lock(&pd->iosched.lock);
 904                 if (pd->iosched.writing)
 905                         bio = bio_list_pop(&pd->iosched.write_queue);
 906                 else
 907                         bio = bio_list_pop(&pd->iosched.read_queue);
 908                 spin_unlock(&pd->iosched.lock);
 909
 910                 if (!bio)
 911                         continue;
 912
 913                 if (bio_data_dir(bio) == READ)
 914                         pd->iosched.successive_reads +=
 915                                 bio->bi_iter.bi_size >> 10;
 916                 else {
 917                         pd->iosched.successive_reads = 0;
 918                         pd->iosched.last_write = bio_end_sector(bio);
 919                 }
 920                 if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
 921                         if (pd->read_speed == pd->write_speed) {
 922                                 pd->read_speed = MAX_SPEED;
 923                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 924                         }
 925                 } else {
 926                         if (pd->read_speed != pd->write_speed) {
 927                                 pd->read_speed = pd->write_speed;
 928                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 929                         }
 930                 }
 931
 932                 atomic_inc(&pd->cdrw.pending_bios);
 933                 submit_bio_noacct(bio);
 934         }
 935 }
 936
 937 /*
 938  * Special care is needed if the underlying block device has a small
 939  * max_phys_segments value.
 940  */
 941 static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
 942 {
 943         struct device *ddev = disk_to_dev(pd->disk);
 944
 945         if ((pd->settings.size << 9) / CD_FRAMESIZE <= queue_max_segments(q)) {
 946                 /*
 947                  * The cdrom device can handle one segment/frame
 948                  */
 949                 clear_bit(PACKET_MERGE_SEGS, &pd->flags);
 950                 return 0;
 951         }
 952
 953         if ((pd->settings.size << 9) / PAGE_SIZE <= queue_max_segments(q)) {
 954                 /*
 955                  * We can handle this case at the expense of some extra memory
 956                  * copies during write operations
 957                  */
 958                 set_bit(PACKET_MERGE_SEGS, &pd->flags);
 959                 return 0;
 960         }
 961
 962         dev_err(ddev, "cdrom max_phys_segments too small\n");
 963         return -EIO;
 964 }
 965
 966 static void pkt_end_io_read(struct bio *bio)
 967 {
 968         struct packet_data *pkt = bio->bi_private;
 969         struct pktcdvd_device *pd = pkt->pd;
 970         BUG_ON(!pd);
 971
 972         dev_dbg(disk_to_dev(pd->disk), "bio=%p sec0=%llx sec=%llx err=%d\n",
 973                 bio, pkt->sector, bio->bi_iter.bi_sector, bio->bi_status);
 974
 975         if (bio->bi_status)
 976                 atomic_inc(&pkt->io_errors);
 977         bio_uninit(bio);
 978         if (atomic_dec_and_test(&pkt->io_wait)) {
 979                 atomic_inc(&pkt->run_sm);
 980                 wake_up(&pd->wqueue);
 981         }
 982         pkt_bio_finished(pd);
 983 }
 984
 985 static void pkt_end_io_packet_write(struct bio *bio)
 986 {
 987         struct packet_data *pkt = bio->bi_private;
 988         struct pktcdvd_device *pd = pkt->pd;
 989         BUG_ON(!pd);
 990
 991         dev_dbg(disk_to_dev(pd->disk), "id=%d, err=%d\n", pkt->id, bio->bi_status);
 992
 993         pd->stats.pkt_ended++;
 994
 995         bio_uninit(bio);
 996         pkt_bio_finished(pd);
 997         atomic_dec(&pkt->io_wait);
 998         atomic_inc(&pkt->run_sm);
 999         wake_up(&pd->wqueue);
1000 }
1001
1002 /*
1003  * Schedule reads for the holes in a packet
1004  */
1005 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1006 {
1007         struct device *ddev = disk_to_dev(pd->disk);
1008         int frames_read = 0;
1009         struct bio *bio;
1010         int f;
1011         char written[PACKET_MAX_SIZE];
1012
1013         BUG_ON(bio_list_empty(&pkt->orig_bios));
1014
1015         atomic_set(&pkt->io_wait, 0);
1016         atomic_set(&pkt->io_errors, 0);
1017
1018         /*
1019          * Figure out which frames we need to read before we can write.
1020          */
1021         memset(written, 0, sizeof(written));
1022         spin_lock(&pkt->lock);
1023         bio_list_for_each(bio, &pkt->orig_bios) {
1024                 int first_frame = (bio->bi_iter.bi_sector - pkt->sector) /
1025                         (CD_FRAMESIZE >> 9);
1026                 int num_frames = bio->bi_iter.bi_size / CD_FRAMESIZE;
1027                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1028                 BUG_ON(first_frame < 0);
1029                 BUG_ON(first_frame + num_frames > pkt->frames);
1030                 for (f = first_frame; f < first_frame + num_frames; f++)
1031                         written[f] = 1;
1032         }
1033         spin_unlock(&pkt->lock);
1034
1035         if (pkt->cache_valid) {
1036                 dev_dbg(ddev, "zone %llx cached\n", pkt->sector);
1037                 goto out_account;
1038         }
1039
1040         /*
1041          * Schedule reads for missing parts of the packet.
1042          */
1043         for (f = 0; f < pkt->frames; f++) {
1044                 int p, offset;
1045
1046                 if (written[f])
1047                         continue;
1048
1049                 bio = pkt->r_bios[f];
1050                 bio_init(bio, pd->bdev, bio->bi_inline_vecs, 1, REQ_OP_READ);
1051                 bio->bi_iter.bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1052                 bio->bi_end_io = pkt_end_io_read;
1053                 bio->bi_private = pkt;
1054
1055                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1056                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1057                 dev_dbg(ddev, "Adding frame %d, page:%p offs:%d\n", f,
1058                         pkt->pages[p], offset);
1059                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1060                         BUG();
1061
1062                 atomic_inc(&pkt->io_wait);
1063                 pkt_queue_bio(pd, bio);
1064                 frames_read++;
1065         }
1066
1067 out_account:
1068         dev_dbg(ddev, "need %d frames for zone %llx\n", frames_read, pkt->sector);
1069         pd->stats.pkt_started++;
1070         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1071 }
1072
1073 /*
1074  * Find a packet matching zone, or the least recently used packet if
1075  * there is no match.
1076  */
1077 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1078 {
1079         struct packet_data *pkt;
1080
1081         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1082                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1083                         list_del_init(&pkt->list);
1084                         if (pkt->sector != zone)
1085                                 pkt->cache_valid = 0;
1086                         return pkt;
1087                 }
1088         }
1089         BUG();
1090         return NULL;
1091 }
1092
1093 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1094 {
1095         if (pkt->cache_valid) {
1096                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1097         } else {
1098                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1099         }
1100 }
1101
1102 static inline void pkt_set_state(struct device *ddev, struct packet_data *pkt,
1103                                  enum packet_data_state state)
1104 {
1105         static const char *state_name[] = {
1106                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1107         };
1108         enum packet_data_state old_state = pkt->state;
1109
1110         dev_dbg(ddev, "pkt %2d : s=%6llx %s -> %s\n",
1111                 pkt->id, pkt->sector, state_name[old_state], state_name[state]);
1112
1113         pkt->state = state;
1114 }
1115
1116 /*
1117  * Scan the work queue to see if we can start a new packet.
1118  * returns non-zero if any work was done.
1119  */
1120 static int pkt_handle_queue(struct pktcdvd_device *pd)
1121 {
1122         struct device *ddev = disk_to_dev(pd->disk);
1123         struct packet_data *pkt, *p;
1124         struct bio *bio = NULL;
1125         sector_t zone = 0; /* Suppress gcc warning */
1126         struct pkt_rb_node *node, *first_node;
1127         struct rb_node *n;
1128
1129         atomic_set(&pd->scan_queue, 0);
1130
1131         if (list_empty(&pd->cdrw.pkt_free_list)) {
1132                 dev_dbg(ddev, "no pkt\n");
1133                 return 0;
1134         }
1135
1136         /*
1137          * Try to find a zone we are not already working on.
1138          */
1139         spin_lock(&pd->lock);
1140         first_node = pkt_rbtree_find(pd, pd->current_sector);
1141         if (!first_node) {
1142                 n = rb_first(&pd->bio_queue);
1143                 if (n)
1144                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1145         }
1146         node = first_node;
1147         while (node) {
1148                 bio = node->bio;
1149                 zone = get_zone(bio->bi_iter.bi_sector, pd);
1150                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1151                         if (p->sector == zone) {
1152                                 bio = NULL;
1153                                 goto try_next_bio;
1154                         }
1155                 }
1156                 break;
1157 try_next_bio:
1158                 node = pkt_rbtree_next(node);
1159                 if (!node) {
1160                         n = rb_first(&pd->bio_queue);
1161                         if (n)
1162                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1163                 }
1164                 if (node == first_node)
1165                         node = NULL;
1166         }
1167         spin_unlock(&pd->lock);
1168         if (!bio) {
1169                 dev_dbg(ddev, "no bio\n");
1170                 return 0;
1171         }
1172
1173         pkt = pkt_get_packet_data(pd, zone);
1174
1175         pd->current_sector = zone + pd->settings.size;
1176         pkt->sector = zone;
1177         BUG_ON(pkt->frames != pd->settings.size >> 2);
1178         pkt->write_size = 0;
1179
1180         /*
1181          * Scan work queue for bios in the same zone and link them
1182          * to this packet.
1183          */
1184         spin_lock(&pd->lock);
1185         dev_dbg(ddev, "looking for zone %llx\n", zone);
1186         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1187                 sector_t tmp = get_zone(node->bio->bi_iter.bi_sector, pd);
1188
1189                 bio = node->bio;
1190                 dev_dbg(ddev, "found zone=%llx\n", tmp);
1191                 if (tmp != zone)
1192                         break;
1193                 pkt_rbtree_erase(pd, node);
1194                 spin_lock(&pkt->lock);
1195                 bio_list_add(&pkt->orig_bios, bio);
1196                 pkt->write_size += bio->bi_iter.bi_size / CD_FRAMESIZE;
1197                 spin_unlock(&pkt->lock);
1198         }
1199         /* check write congestion marks, and if bio_queue_size is
1200          * below, wake up any waiters
1201          */
1202         if (pd->congested &&
1203             pd->bio_queue_size <= pd->write_congestion_off) {
1204                 pd->congested = false;
1205                 wake_up_var(&pd->congested);
1206         }
1207         spin_unlock(&pd->lock);
1208
1209         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1210         pkt_set_state(ddev, pkt, PACKET_WAITING_STATE);
1211         atomic_set(&pkt->run_sm, 1);
1212
1213         spin_lock(&pd->cdrw.active_list_lock);
1214         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1215         spin_unlock(&pd->cdrw.active_list_lock);
1216
1217         return 1;
1218 }
1219
1220 /**
1221  * bio_list_copy_data - copy contents of data buffers from one chain of bios to
1222  * another
1223  * @src: source bio list
1224  * @dst: destination bio list
1225  *
1226  * Stops when it reaches the end of either the @src list or @dst list - that is,
1227  * copies min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of
1228  * bios).
1229  */
1230 static void bio_list_copy_data(struct bio *dst, struct bio *src)
1231 {
1232         struct bvec_iter src_iter = src->bi_iter;
1233         struct bvec_iter dst_iter = dst->bi_iter;
1234
1235         while (1) {
1236                 if (!src_iter.bi_size) {
1237                         src = src->bi_next;
1238                         if (!src)
1239                                 break;
1240
1241                         src_iter = src->bi_iter;
1242                 }
1243
1244                 if (!dst_iter.bi_size) {
1245                         dst = dst->bi_next;
1246                         if (!dst)
1247                                 break;
1248
1249                         dst_iter = dst->bi_iter;
1250                 }
1251
1252                 bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
1253         }
1254 }
1255
1256 /*
1257  * Assemble a bio to write one packet and queue the bio for processing
1258  * by the underlying block device.
1259  */
1260 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1261 {
1262         struct device *ddev = disk_to_dev(pd->disk);
1263         int f;
1264
1265         bio_init(pkt->w_bio, pd->bdev, pkt->w_bio->bi_inline_vecs, pkt->frames,
1266                  REQ_OP_WRITE);
1267         pkt->w_bio->bi_iter.bi_sector = pkt->sector;
1268         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1269         pkt->w_bio->bi_private = pkt;
1270
1271         /* XXX: locking? */
1272         for (f = 0; f < pkt->frames; f++) {
1273                 struct page *page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1274                 unsigned offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1275
1276                 if (!bio_add_page(pkt->w_bio, page, CD_FRAMESIZE, offset))
1277                         BUG();
1278         }
1279         dev_dbg(ddev, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
1280
1281         /*
1282          * Fill-in bvec with data from orig_bios.
1283          */
1284         spin_lock(&pkt->lock);
1285         bio_list_copy_data(pkt->w_bio, pkt->orig_bios.head);
1286
1287         pkt_set_state(ddev, pkt, PACKET_WRITE_WAIT_STATE);
1288         spin_unlock(&pkt->lock);
1289
1290         dev_dbg(ddev, "Writing %d frames for zone %llx\n", pkt->write_size, pkt->sector);
1291
1292         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames))
1293                 pkt->cache_valid = 1;
1294         else
1295                 pkt->cache_valid = 0;
1296
1297         /* Start the write request */
1298         atomic_set(&pkt->io_wait, 1);
1299         pkt_queue_bio(pd, pkt->w_bio);
1300 }
1301
1302 static void pkt_finish_packet(struct packet_data *pkt, blk_status_t status)
1303 {
1304         struct bio *bio;
1305
1306         if (status)
1307                 pkt->cache_valid = 0;
1308
1309         /* Finish all bios corresponding to this packet */
1310         while ((bio = bio_list_pop(&pkt->orig_bios))) {
1311                 bio->bi_status = status;
1312                 bio_endio(bio);
1313         }
1314 }
1315
1316 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1317 {
1318         struct device *ddev = disk_to_dev(pd->disk);
1319
1320         dev_dbg(ddev, "pkt %d\n", pkt->id);
1321
1322         for (;;) {
1323                 switch (pkt->state) {
1324                 case PACKET_WAITING_STATE:
1325                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1326                                 return;
1327
1328                         pkt->sleep_time = 0;
1329                         pkt_gather_data(pd, pkt);
1330                         pkt_set_state(ddev, pkt, PACKET_READ_WAIT_STATE);
1331                         break;
1332
1333                 case PACKET_READ_WAIT_STATE:
1334                         if (atomic_read(&pkt->io_wait) > 0)
1335                                 return;
1336
1337                         if (atomic_read(&pkt->io_errors) > 0) {
1338                                 pkt_set_state(ddev, pkt, PACKET_RECOVERY_STATE);
1339                         } else {
1340                                 pkt_start_write(pd, pkt);
1341                         }
1342                         break;
1343
1344                 case PACKET_WRITE_WAIT_STATE:
1345                         if (atomic_read(&pkt->io_wait) > 0)
1346                                 return;
1347
1348                         if (!pkt->w_bio->bi_status) {
1349                                 pkt_set_state(ddev, pkt, PACKET_FINISHED_STATE);
1350                         } else {
1351                                 pkt_set_state(ddev, pkt, PACKET_RECOVERY_STATE);
1352                         }
1353                         break;
1354
1355                 case PACKET_RECOVERY_STATE:
1356                         dev_dbg(ddev, "No recovery possible\n");
1357                         pkt_set_state(ddev, pkt, PACKET_FINISHED_STATE);
1358                         break;
1359
1360                 case PACKET_FINISHED_STATE:
1361                         pkt_finish_packet(pkt, pkt->w_bio->bi_status);
1362                         return;
1363
1364                 default:
1365                         BUG();
1366                         break;
1367                 }
1368         }
1369 }
1370
1371 static void pkt_handle_packets(struct pktcdvd_device *pd)
1372 {
1373         struct device *ddev = disk_to_dev(pd->disk);
1374         struct packet_data *pkt, *next;
1375
1376         /*
1377          * Run state machine for active packets
1378          */
1379         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1380                 if (atomic_read(&pkt->run_sm) > 0) {
1381                         atomic_set(&pkt->run_sm, 0);
1382                         pkt_run_state_machine(pd, pkt);
1383                 }
1384         }
1385
1386         /*
1387          * Move no longer active packets to the free list
1388          */
1389         spin_lock(&pd->cdrw.active_list_lock);
1390         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1391                 if (pkt->state == PACKET_FINISHED_STATE) {
1392                         list_del(&pkt->list);
1393                         pkt_put_packet_data(pd, pkt);
1394                         pkt_set_state(ddev, pkt, PACKET_IDLE_STATE);
1395                         atomic_set(&pd->scan_queue, 1);
1396                 }
1397         }
1398         spin_unlock(&pd->cdrw.active_list_lock);
1399 }
1400
1401 /*
1402  * kcdrwd is woken up when writes have been queued for one of our
1403  * registered devices
1404  */
1405 static int kcdrwd(void *foobar)
1406 {
1407         struct pktcdvd_device *pd = foobar;
1408         struct device *ddev = disk_to_dev(pd->disk);
1409         struct packet_data *pkt;
1410         int states[PACKET_NUM_STATES];
1411         long min_sleep_time, residue;
1412
1413         set_user_nice(current, MIN_NICE);
1414         set_freezable();
1415
1416         for (;;) {
1417                 DECLARE_WAITQUEUE(wait, current);
1418
1419                 /*
1420                  * Wait until there is something to do
1421                  */
1422                 add_wait_queue(&pd->wqueue, &wait);
1423                 for (;;) {
1424                         set_current_state(TASK_INTERRUPTIBLE);
1425
1426                         /* Check if we need to run pkt_handle_queue */
1427                         if (atomic_read(&pd->scan_queue) > 0)
1428                                 goto work_to_do;
1429
1430                         /* Check if we need to run the state machine for some packet */
1431                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1432                                 if (atomic_read(&pkt->run_sm) > 0)
1433                                         goto work_to_do;
1434                         }
1435
1436                         /* Check if we need to process the iosched queues */
1437                         if (atomic_read(&pd->iosched.attention) != 0)
1438                                 goto work_to_do;
1439
1440                         /* Otherwise, go to sleep */
1441                         pkt_count_states(pd, states);
1442                         dev_dbg(ddev, "i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1443                                 states[0], states[1], states[2], states[3], states[4], states[5]);
1444
1445                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1446                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1447                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1448                                         min_sleep_time = pkt->sleep_time;
1449                         }
1450
1451                         dev_dbg(ddev, "sleeping\n");
1452                         residue = schedule_timeout(min_sleep_time);
1453                         dev_dbg(ddev, "wake up\n");
1454
1455                         /* make swsusp happy with our thread */
1456                         try_to_freeze();
1457
1458                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1459                                 if (!pkt->sleep_time)
1460                                         continue;
1461                                 pkt->sleep_time -= min_sleep_time - residue;
1462                                 if (pkt->sleep_time <= 0) {
1463                                         pkt->sleep_time = 0;
1464                                         atomic_inc(&pkt->run_sm);
1465                                 }
1466                         }
1467
1468                         if (kthread_should_stop())
1469                                 break;
1470                 }
1471 work_to_do:
1472                 set_current_state(TASK_RUNNING);
1473                 remove_wait_queue(&pd->wqueue, &wait);
1474
1475                 if (kthread_should_stop())
1476                         break;
1477
1478                 /*
1479                  * if pkt_handle_queue returns true, we can queue
1480                  * another request.
1481                  */
1482                 while (pkt_handle_queue(pd))
1483                         ;
1484
1485                 /*
1486                  * Handle packet state machine
1487                  */
1488                 pkt_handle_packets(pd);
1489
1490                 /*
1491                  * Handle iosched queues
1492                  */
1493                 pkt_iosched_process_queue(pd);
1494         }
1495
1496         return 0;
1497 }
1498
1499 static void pkt_print_settings(struct pktcdvd_device *pd)
1500 {
1501         dev_info(disk_to_dev(pd->disk), "%s packets, %u blocks, Mode-%c disc\n",
1502                  pd->settings.fp ? "Fixed" : "Variable",
1503                  pd->settings.size >> 2,
1504                  pd->settings.block_mode == 8 ? '1' : '2');
1505 }
1506
1507 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1508 {
1509         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1510
1511         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1512         cgc->cmd[2] = page_code | (page_control << 6);
1513         put_unaligned_be16(cgc->buflen, &cgc->cmd[7]);
1514         cgc->data_direction = CGC_DATA_READ;
1515         return pkt_generic_packet(pd, cgc);
1516 }
1517
1518 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1519 {
1520         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1521         memset(cgc->buffer, 0, 2);
1522         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1523         cgc->cmd[1] = 0x10;             /* PF */
1524         put_unaligned_be16(cgc->buflen, &cgc->cmd[7]);
1525         cgc->data_direction = CGC_DATA_WRITE;
1526         return pkt_generic_packet(pd, cgc);
1527 }
1528
1529 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1530 {
1531         struct packet_command cgc;
1532         int ret;
1533
1534         /* set up command and get the disc info */
1535         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1536         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1537         cgc.cmd[8] = cgc.buflen = 2;
1538         cgc.quiet = 1;
1539
1540         ret = pkt_generic_packet(pd, &cgc);
1541         if (ret)
1542                 return ret;
1543
1544         /* not all drives have the same disc_info length, so requeue
1545          * packet with the length the drive tells us it can supply
1546          */
1547         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1548                      sizeof(di->disc_information_length);
1549
1550         if (cgc.buflen > sizeof(disc_information))
1551                 cgc.buflen = sizeof(disc_information);
1552
1553         cgc.cmd[8] = cgc.buflen;
1554         return pkt_generic_packet(pd, &cgc);
1555 }
1556
1557 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1558 {
1559         struct packet_command cgc;
1560         int ret;
1561
1562         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1563         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1564         cgc.cmd[1] = type & 3;
1565         put_unaligned_be16(track, &cgc.cmd[4]);
1566         cgc.cmd[8] = 8;
1567         cgc.quiet = 1;
1568
1569         ret = pkt_generic_packet(pd, &cgc);
1570         if (ret)
1571                 return ret;
1572
1573         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1574                      sizeof(ti->track_information_length);
1575
1576         if (cgc.buflen > sizeof(track_information))
1577                 cgc.buflen = sizeof(track_information);
1578
1579         cgc.cmd[8] = cgc.buflen;
1580         return pkt_generic_packet(pd, &cgc);
1581 }
1582
1583 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1584                                                 long *last_written)
1585 {
1586         disc_information di;
1587         track_information ti;
1588         __u32 last_track;
1589         int ret;
1590
1591         ret = pkt_get_disc_info(pd, &di);
1592         if (ret)
1593                 return ret;
1594
1595         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1596         ret = pkt_get_track_info(pd, last_track, 1, &ti);
1597         if (ret)
1598                 return ret;
1599
1600         /* if this track is blank, try the previous. */
1601         if (ti.blank) {
1602                 last_track--;
1603                 ret = pkt_get_track_info(pd, last_track, 1, &ti);
1604                 if (ret)
1605                         return ret;
1606         }
1607
1608         /* if last recorded field is valid, return it. */
1609         if (ti.lra_v) {
1610                 *last_written = be32_to_cpu(ti.last_rec_address);
1611         } else {
1612                 /* make it up instead */
1613                 *last_written = be32_to_cpu(ti.track_start) +
1614                                 be32_to_cpu(ti.track_size);
1615                 if (ti.free_blocks)
1616                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1617         }
1618         return 0;
1619 }
1620
1621 /*
1622  * write mode select package based on pd->settings
1623  */
1624 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1625 {
1626         struct device *ddev = disk_to_dev(pd->disk);
1627         struct packet_command cgc;
1628         struct scsi_sense_hdr sshdr;
1629         write_param_page *wp;
1630         char buffer[128];
1631         int ret, size;
1632
1633         /* doesn't apply to DVD+RW or DVD-RAM */
1634         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1635                 return 0;
1636
1637         memset(buffer, 0, sizeof(buffer));
1638         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1639         cgc.sshdr = &sshdr;
1640         ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1641         if (ret) {
1642                 pkt_dump_sense(pd, &cgc);
1643                 return ret;
1644         }
1645
1646         size = 2 + get_unaligned_be16(&buffer[0]);
1647         pd->mode_offset = get_unaligned_be16(&buffer[6]);
1648         if (size > sizeof(buffer))
1649                 size = sizeof(buffer);
1650
1651         /*
1652          * now get it all
1653          */
1654         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1655         cgc.sshdr = &sshdr;
1656         ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1657         if (ret) {
1658                 pkt_dump_sense(pd, &cgc);
1659                 return ret;
1660         }
1661
1662         /*
1663          * write page is offset header + block descriptor length
1664          */
1665         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1666
1667         wp->fp = pd->settings.fp;
1668         wp->track_mode = pd->settings.track_mode;
1669         wp->write_type = pd->settings.write_type;
1670         wp->data_block_type = pd->settings.block_mode;
1671
1672         wp->multi_session = 0;
1673
1674 #ifdef PACKET_USE_LS
1675         wp->link_size = 7;
1676         wp->ls_v = 1;
1677 #endif
1678
1679         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1680                 wp->session_format = 0;
1681                 wp->subhdr2 = 0x20;
1682         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1683                 wp->session_format = 0x20;
1684                 wp->subhdr2 = 8;
1685 #if 0
1686                 wp->mcn[0] = 0x80;
1687                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1688 #endif
1689         } else {
1690                 /*
1691                  * paranoia
1692                  */
1693                 dev_err(ddev, "write mode wrong %d\n", wp->data_block_type);
1694                 return 1;
1695         }
1696         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1697
1698         cgc.buflen = cgc.cmd[8] = size;
1699         ret = pkt_mode_select(pd, &cgc);
1700         if (ret) {
1701                 pkt_dump_sense(pd, &cgc);
1702                 return ret;
1703         }
1704
1705         pkt_print_settings(pd);
1706         return 0;
1707 }
1708
1709 /*
1710  * 1 -- we can write to this track, 0 -- we can't
1711  */
1712 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1713 {
1714         struct device *ddev = disk_to_dev(pd->disk);
1715
1716         switch (pd->mmc3_profile) {
1717                 case 0x1a: /* DVD+RW */
1718                 case 0x12: /* DVD-RAM */
1719                         /* The track is always writable on DVD+RW/DVD-RAM */
1720                         return 1;
1721                 default:
1722                         break;
1723         }
1724
1725         if (!ti->packet || !ti->fp)
1726                 return 0;
1727
1728         /*
1729          * "good" settings as per Mt Fuji.
1730          */
1731         if (ti->rt == 0 && ti->blank == 0)
1732                 return 1;
1733
1734         if (ti->rt == 0 && ti->blank == 1)
1735                 return 1;
1736
1737         if (ti->rt == 1 && ti->blank == 0)
1738                 return 1;
1739
1740         dev_err(ddev, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1741         return 0;
1742 }
1743
1744 /*
1745  * 1 -- we can write to this disc, 0 -- we can't
1746  */
1747 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1748 {
1749         struct device *ddev = disk_to_dev(pd->disk);
1750
1751         switch (pd->mmc3_profile) {
1752                 case 0x0a: /* CD-RW */
1753                 case 0xffff: /* MMC3 not supported */
1754                         break;
1755                 case 0x1a: /* DVD+RW */
1756                 case 0x13: /* DVD-RW */
1757                 case 0x12: /* DVD-RAM */
1758                         return 1;
1759                 default:
1760                         dev_dbg(ddev, "Wrong disc profile (%x)\n", pd->mmc3_profile);
1761                         return 0;
1762         }
1763
1764         /*
1765          * for disc type 0xff we should probably reserve a new track.
1766          * but i'm not sure, should we leave this to user apps? probably.
1767          */
1768         if (di->disc_type == 0xff) {
1769                 dev_notice(ddev, "unknown disc - no track?\n");
1770                 return 0;
1771         }
1772
1773         if (di->disc_type != 0x20 && di->disc_type != 0) {
1774                 dev_err(ddev, "wrong disc type (%x)\n", di->disc_type);
1775                 return 0;
1776         }
1777
1778         if (di->erasable == 0) {
1779                 dev_err(ddev, "disc not erasable\n");
1780                 return 0;
1781         }
1782
1783         if (di->border_status == PACKET_SESSION_RESERVED) {
1784                 dev_err(ddev, "can't write to last track (reserved)\n");
1785                 return 0;
1786         }
1787
1788         return 1;
1789 }
1790
1791 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1792 {
1793         struct device *ddev = disk_to_dev(pd->disk);
1794         struct packet_command cgc;
1795         unsigned char buf[12];
1796         disc_information di;
1797         track_information ti;
1798         int ret, track;
1799
1800         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1801         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1802         cgc.cmd[8] = 8;
1803         ret = pkt_generic_packet(pd, &cgc);
1804         pd->mmc3_profile = ret ? 0xffff : get_unaligned_be16(&buf[6]);
1805
1806         memset(&di, 0, sizeof(disc_information));
1807         memset(&ti, 0, sizeof(track_information));
1808
1809         ret = pkt_get_disc_info(pd, &di);
1810         if (ret) {
1811                 dev_err(ddev, "failed get_disc\n");
1812                 return ret;
1813         }
1814
1815         if (!pkt_writable_disc(pd, &di))
1816                 return -EROFS;
1817
1818         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1819
1820         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1821         ret = pkt_get_track_info(pd, track, 1, &ti);
1822         if (ret) {
1823                 dev_err(ddev, "failed get_track\n");
1824                 return ret;
1825         }
1826
1827         if (!pkt_writable_track(pd, &ti)) {
1828                 dev_err(ddev, "can't write to this track\n");
1829                 return -EROFS;
1830         }
1831
1832         /*
1833          * we keep packet size in 512 byte units, makes it easier to
1834          * deal with request calculations.
1835          */
1836         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1837         if (pd->settings.size == 0) {
1838                 dev_notice(ddev, "detected zero packet size!\n");
1839                 return -ENXIO;
1840         }
1841         if (pd->settings.size > PACKET_MAX_SECTORS) {
1842                 dev_err(ddev, "packet size is too big\n");
1843                 return -EROFS;
1844         }
1845         pd->settings.fp = ti.fp;
1846         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1847
1848         if (ti.nwa_v) {
1849                 pd->nwa = be32_to_cpu(ti.next_writable);
1850                 set_bit(PACKET_NWA_VALID, &pd->flags);
1851         }
1852
1853         /*
1854          * in theory we could use lra on -RW media as well and just zero
1855          * blocks that haven't been written yet, but in practice that
1856          * is just a no-go. we'll use that for -R, naturally.
1857          */
1858         if (ti.lra_v) {
1859                 pd->lra = be32_to_cpu(ti.last_rec_address);
1860                 set_bit(PACKET_LRA_VALID, &pd->flags);
1861         } else {
1862                 pd->lra = 0xffffffff;
1863                 set_bit(PACKET_LRA_VALID, &pd->flags);
1864         }
1865
1866         /*
1867          * fine for now
1868          */
1869         pd->settings.link_loss = 7;
1870         pd->settings.write_type = 0;    /* packet */
1871         pd->settings.track_mode = ti.track_mode;
1872
1873         /*
1874          * mode1 or mode2 disc
1875          */
1876         switch (ti.data_mode) {
1877                 case PACKET_MODE1:
1878                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
1879                         break;
1880                 case PACKET_MODE2:
1881                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
1882                         break;
1883                 default:
1884                         dev_err(ddev, "unknown data mode\n");
1885                         return -EROFS;
1886         }
1887         return 0;
1888 }
1889
1890 /*
1891  * enable/disable write caching on drive
1892  */
1893 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd)
1894 {
1895         struct device *ddev = disk_to_dev(pd->disk);
1896         struct packet_command cgc;
1897         struct scsi_sense_hdr sshdr;
1898         unsigned char buf[64];
1899         bool set = IS_ENABLED(CONFIG_CDROM_PKTCDVD_WCACHE);
1900         int ret;
1901
1902         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1903         cgc.sshdr = &sshdr;
1904         cgc.buflen = pd->mode_offset + 12;
1905
1906         /*
1907          * caching mode page might not be there, so quiet this command
1908          */
1909         cgc.quiet = 1;
1910
1911         ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0);
1912         if (ret)
1913                 return ret;
1914
1915         /*
1916          * use drive write caching -- we need deferred error handling to be
1917          * able to successfully recover with this option (drive will return good
1918          * status as soon as the cdb is validated).
1919          */
1920         buf[pd->mode_offset + 10] |= (set << 2);
1921
1922         cgc.buflen = cgc.cmd[8] = 2 + get_unaligned_be16(&buf[0]);
1923         ret = pkt_mode_select(pd, &cgc);
1924         if (ret) {
1925                 dev_err(ddev, "write caching control failed\n");
1926                 pkt_dump_sense(pd, &cgc);
1927         } else if (!ret && set)
1928                 dev_notice(ddev, "enabled write caching\n");
1929         return ret;
1930 }
1931
1932 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1933 {
1934         struct packet_command cgc;
1935
1936         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1937         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1938         cgc.cmd[4] = lockflag ? 1 : 0;
1939         return pkt_generic_packet(pd, &cgc);
1940 }
1941
1942 /*
1943  * Returns drive maximum write speed
1944  */
1945 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1946                                                 unsigned *write_speed)
1947 {
1948         struct packet_command cgc;
1949         struct scsi_sense_hdr sshdr;
1950         unsigned char buf[256+18];
1951         unsigned char *cap_buf;
1952         int ret, offset;
1953
1954         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1955         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1956         cgc.sshdr = &sshdr;
1957
1958         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1959         if (ret) {
1960                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
1961                              sizeof(struct mode_page_header);
1962                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1963                 if (ret) {
1964                         pkt_dump_sense(pd, &cgc);
1965                         return ret;
1966                 }
1967         }
1968
1969         offset = 20;                        /* Obsoleted field, used by older drives */
1970         if (cap_buf[1] >= 28)
1971                 offset = 28;                /* Current write speed selected */
1972         if (cap_buf[1] >= 30) {
1973                 /* If the drive reports at least one "Logical Unit Write
1974                  * Speed Performance Descriptor Block", use the information
1975                  * in the first block. (contains the highest speed)
1976                  */
1977                 int num_spdb = get_unaligned_be16(&cap_buf[30]);
1978                 if (num_spdb > 0)
1979                         offset = 34;
1980         }
1981
1982         *write_speed = get_unaligned_be16(&cap_buf[offset]);
1983         return 0;
1984 }
1985
1986 /* These tables from cdrecord - I don't have orange book */
1987 /* standard speed CD-RW (1-4x) */
1988 static char clv_to_speed[16] = {
1989         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1990            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1991 };
1992 /* high speed CD-RW (-10x) */
1993 static char hs_clv_to_speed[16] = {
1994         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1995            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1996 };
1997 /* ultra high speed CD-RW */
1998 static char us_clv_to_speed[16] = {
1999         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2000            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2001 };
2002
2003 /*
2004  * reads the maximum media speed from ATIP
2005  */
2006 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2007                                                 unsigned *speed)
2008 {
2009         struct device *ddev = disk_to_dev(pd->disk);
2010         struct packet_command cgc;
2011         struct scsi_sense_hdr sshdr;
2012         unsigned char buf[64];
2013         unsigned int size, st, sp;
2014         int ret;
2015
2016         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2017         cgc.sshdr = &sshdr;
2018         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2019         cgc.cmd[1] = 2;
2020         cgc.cmd[2] = 4; /* READ ATIP */
2021         cgc.cmd[8] = 2;
2022         ret = pkt_generic_packet(pd, &cgc);
2023         if (ret) {
2024                 pkt_dump_sense(pd, &cgc);
2025                 return ret;
2026         }
2027         size = 2 + get_unaligned_be16(&buf[0]);
2028         if (size > sizeof(buf))
2029                 size = sizeof(buf);
2030
2031         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2032         cgc.sshdr = &sshdr;
2033         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2034         cgc.cmd[1] = 2;
2035         cgc.cmd[2] = 4;
2036         cgc.cmd[8] = size;
2037         ret = pkt_generic_packet(pd, &cgc);
2038         if (ret) {
2039                 pkt_dump_sense(pd, &cgc);
2040                 return ret;
2041         }
2042
2043         if (!(buf[6] & 0x40)) {
2044                 dev_notice(ddev, "disc type is not CD-RW\n");
2045                 return 1;
2046         }
2047         if (!(buf[6] & 0x4)) {
2048                 dev_notice(ddev, "A1 values on media are not valid, maybe not CDRW?\n");
2049                 return 1;
2050         }
2051
2052         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2053
2054         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2055
2056         /* Info from cdrecord */
2057         switch (st) {
2058                 case 0: /* standard speed */
2059                         *speed = clv_to_speed[sp];
2060                         break;
2061                 case 1: /* high speed */
2062                         *speed = hs_clv_to_speed[sp];
2063                         break;
2064                 case 2: /* ultra high speed */
2065                         *speed = us_clv_to_speed[sp];
2066                         break;
2067                 default:
2068                         dev_notice(ddev, "unknown disc sub-type %d\n", st);
2069                         return 1;
2070         }
2071         if (*speed) {
2072                 dev_info(ddev, "maximum media speed: %d\n", *speed);
2073                 return 0;
2074         } else {
2075                 dev_notice(ddev, "unknown speed %d for sub-type %d\n", sp, st);
2076                 return 1;
2077         }
2078 }
2079
2080 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2081 {
2082         struct device *ddev = disk_to_dev(pd->disk);
2083         struct packet_command cgc;
2084         struct scsi_sense_hdr sshdr;
2085         int ret;
2086
2087         dev_dbg(ddev, "Performing OPC\n");
2088
2089         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2090         cgc.sshdr = &sshdr;
2091         cgc.timeout = 60*HZ;
2092         cgc.cmd[0] = GPCMD_SEND_OPC;
2093         cgc.cmd[1] = 1;
2094         ret = pkt_generic_packet(pd, &cgc);
2095         if (ret)
2096                 pkt_dump_sense(pd, &cgc);
2097         return ret;
2098 }
2099
2100 static int pkt_open_write(struct pktcdvd_device *pd)
2101 {
2102         struct device *ddev = disk_to_dev(pd->disk);
2103         int ret;
2104         unsigned int write_speed, media_write_speed, read_speed;
2105
2106         ret = pkt_probe_settings(pd);
2107         if (ret) {
2108                 dev_dbg(ddev, "failed probe\n");
2109                 return ret;
2110         }
2111
2112         ret = pkt_set_write_settings(pd);
2113         if (ret) {
2114                 dev_notice(ddev, "failed saving write settings\n");
2115                 return -EIO;
2116         }
2117
2118         pkt_write_caching(pd);
2119
2120         ret = pkt_get_max_speed(pd, &write_speed);
2121         if (ret)
2122                 write_speed = 16 * 177;
2123         switch (pd->mmc3_profile) {
2124                 case 0x13: /* DVD-RW */
2125                 case 0x1a: /* DVD+RW */
2126                 case 0x12: /* DVD-RAM */
2127                         dev_notice(ddev, "write speed %ukB/s\n", write_speed);
2128                         break;
2129                 default:
2130                         ret = pkt_media_speed(pd, &media_write_speed);
2131                         if (ret)
2132                                 media_write_speed = 16;
2133                         write_speed = min(write_speed, media_write_speed * 177);
2134                         dev_notice(ddev, "write speed %ux\n", write_speed / 176);
2135                         break;
2136         }
2137         read_speed = write_speed;
2138
2139         ret = pkt_set_speed(pd, write_speed, read_speed);
2140         if (ret) {
2141                 dev_notice(ddev, "couldn't set write speed\n");
2142                 return -EIO;
2143         }
2144         pd->write_speed = write_speed;
2145         pd->read_speed = read_speed;
2146
2147         ret = pkt_perform_opc(pd);
2148         if (ret)
2149                 dev_notice(ddev, "Optimum Power Calibration failed\n");
2150
2151         return 0;
2152 }
2153
2154 /*
2155  * called at open time.
2156  */
2157 static int pkt_open_dev(struct pktcdvd_device *pd, bool write)
2158 {
2159         struct device *ddev = disk_to_dev(pd->disk);
2160         int ret;
2161         long lba;
2162         struct request_queue *q;
2163         struct block_device *bdev;
2164
2165         /*
2166          * We need to re-open the cdrom device without O_NONBLOCK to be able
2167          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2168          * so open should not fail.
2169          */
2170         bdev = blkdev_get_by_dev(pd->bdev->bd_dev, BLK_OPEN_READ, pd, NULL);
2171         if (IS_ERR(bdev)) {
2172                 ret = PTR_ERR(bdev);
2173                 goto out;
2174         }
2175
2176         ret = pkt_get_last_written(pd, &lba);
2177         if (ret) {
2178                 dev_err(ddev, "pkt_get_last_written failed\n");
2179                 goto out_putdev;
2180         }
2181
2182         set_capacity(pd->disk, lba << 2);
2183         set_capacity_and_notify(pd->bdev->bd_disk, lba << 2);
2184
2185         q = bdev_get_queue(pd->bdev);
2186         if (write) {
2187                 ret = pkt_open_write(pd);
2188                 if (ret)
2189                         goto out_putdev;
2190                 /*
2191                  * Some CDRW drives can not handle writes larger than one packet,
2192                  * even if the size is a multiple of the packet size.
2193                  */
2194                 blk_queue_max_hw_sectors(q, pd->settings.size);
2195                 set_bit(PACKET_WRITABLE, &pd->flags);
2196         } else {
2197                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2198                 clear_bit(PACKET_WRITABLE, &pd->flags);
2199         }
2200
2201         ret = pkt_set_segment_merging(pd, q);
2202         if (ret)
2203                 goto out_putdev;
2204
2205         if (write) {
2206                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2207                         dev_err(ddev, "not enough memory for buffers\n");
2208                         ret = -ENOMEM;
2209                         goto out_putdev;
2210                 }
2211                 dev_info(ddev, "%lukB available on disc\n", lba << 1);
2212         }
2213
2214         return 0;
2215
2216 out_putdev:
2217         blkdev_put(bdev, pd);
2218 out:
2219         return ret;
2220 }
2221
2222 /*
2223  * called when the device is closed. makes sure that the device flushes
2224  * the internal cache before we close.
2225  */
2226 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2227 {
2228         struct device *ddev = disk_to_dev(pd->disk);
2229
2230         if (flush && pkt_flush_cache(pd))
2231                 dev_notice(ddev, "not flushing cache\n");
2232
2233         pkt_lock_door(pd, 0);
2234
2235         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2236         blkdev_put(pd->bdev, pd);
2237
2238         pkt_shrink_pktlist(pd);
2239 }
2240
2241 static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2242 {
2243         if (dev_minor >= MAX_WRITERS)
2244                 return NULL;
2245
2246         dev_minor = array_index_nospec(dev_minor, MAX_WRITERS);
2247         return pkt_devs[dev_minor];
2248 }
2249
2250 static int pkt_open(struct gendisk *disk, blk_mode_t mode)
2251 {
2252         struct pktcdvd_device *pd = NULL;
2253         int ret;
2254
2255         mutex_lock(&pktcdvd_mutex);
2256         mutex_lock(&ctl_mutex);
2257         pd = pkt_find_dev_from_minor(disk->first_minor);
2258         if (!pd) {
2259                 ret = -ENODEV;
2260                 goto out;
2261         }
2262         BUG_ON(pd->refcnt < 0);
2263
2264         pd->refcnt++;
2265         if (pd->refcnt > 1) {
2266                 if ((mode & BLK_OPEN_WRITE) &&
2267                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2268                         ret = -EBUSY;
2269                         goto out_dec;
2270                 }
2271         } else {
2272                 ret = pkt_open_dev(pd, mode & BLK_OPEN_WRITE);
2273                 if (ret)
2274                         goto out_dec;
2275                 /*
2276                  * needed here as well, since ext2 (among others) may change
2277                  * the blocksize at mount time
2278                  */
2279                 set_blocksize(disk->part0, CD_FRAMESIZE);
2280         }
2281         mutex_unlock(&ctl_mutex);
2282         mutex_unlock(&pktcdvd_mutex);
2283         return 0;
2284
2285 out_dec:
2286         pd->refcnt--;
2287 out:
2288         mutex_unlock(&ctl_mutex);
2289         mutex_unlock(&pktcdvd_mutex);
2290         return ret;
2291 }
2292
2293 static void pkt_release(struct gendisk *disk)
2294 {
2295         struct pktcdvd_device *pd = disk->private_data;
2296
2297         mutex_lock(&pktcdvd_mutex);
2298         mutex_lock(&ctl_mutex);
2299         pd->refcnt--;
2300         BUG_ON(pd->refcnt < 0);
2301         if (pd->refcnt == 0) {
2302                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2303                 pkt_release_dev(pd, flush);
2304         }
2305         mutex_unlock(&ctl_mutex);
2306         mutex_unlock(&pktcdvd_mutex);
2307 }
2308
2309
2310 static void pkt_end_io_read_cloned(struct bio *bio)
2311 {
2312         struct packet_stacked_data *psd = bio->bi_private;
2313         struct pktcdvd_device *pd = psd->pd;
2314
2315         psd->bio->bi_status = bio->bi_status;
2316         bio_put(bio);
2317         bio_endio(psd->bio);
2318         mempool_free(psd, &psd_pool);
2319         pkt_bio_finished(pd);
2320 }
2321
2322 static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
2323 {
2324         struct bio *cloned_bio =
2325                 bio_alloc_clone(pd->bdev, bio, GFP_NOIO, &pkt_bio_set);
2326         struct packet_stacked_data *psd = mempool_alloc(&psd_pool, GFP_NOIO);
2327
2328         psd->pd = pd;
2329         psd->bio = bio;
2330         cloned_bio->bi_private = psd;
2331         cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2332         pd->stats.secs_r += bio_sectors(bio);
2333         pkt_queue_bio(pd, cloned_bio);
2334 }
2335
2336 static void pkt_make_request_write(struct request_queue *q, struct bio *bio)
2337 {
2338         struct pktcdvd_device *pd = q->queuedata;
2339         sector_t zone;
2340         struct packet_data *pkt;
2341         int was_empty, blocked_bio;
2342         struct pkt_rb_node *node;
2343
2344         zone = get_zone(bio->bi_iter.bi_sector, pd);
2345
2346         /*
2347          * If we find a matching packet in state WAITING or READ_WAIT, we can
2348          * just append this bio to that packet.
2349          */
2350         spin_lock(&pd->cdrw.active_list_lock);
2351         blocked_bio = 0;
2352         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2353                 if (pkt->sector == zone) {
2354                         spin_lock(&pkt->lock);
2355                         if ((pkt->state == PACKET_WAITING_STATE) ||
2356                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2357                                 bio_list_add(&pkt->orig_bios, bio);
2358                                 pkt->write_size +=
2359                                         bio->bi_iter.bi_size / CD_FRAMESIZE;
2360                                 if ((pkt->write_size >= pkt->frames) &&
2361                                     (pkt->state == PACKET_WAITING_STATE)) {
2362                                         atomic_inc(&pkt->run_sm);
2363                                         wake_up(&pd->wqueue);
2364                                 }
2365                                 spin_unlock(&pkt->lock);
2366                                 spin_unlock(&pd->cdrw.active_list_lock);
2367                                 return;
2368                         } else {
2369                                 blocked_bio = 1;
2370                         }
2371                         spin_unlock(&pkt->lock);
2372                 }
2373         }
2374         spin_unlock(&pd->cdrw.active_list_lock);
2375
2376         /*
2377          * Test if there is enough room left in the bio work queue
2378          * (queue size >= congestion on mark).
2379          * If not, wait till the work queue size is below the congestion off mark.
2380          */
2381         spin_lock(&pd->lock);
2382         if (pd->write_congestion_on > 0
2383             && pd->bio_queue_size >= pd->write_congestion_on) {
2384                 struct wait_bit_queue_entry wqe;
2385
2386                 init_wait_var_entry(&wqe, &pd->congested, 0);
2387                 for (;;) {
2388                         prepare_to_wait_event(__var_waitqueue(&pd->congested),
2389                                               &wqe.wq_entry,
2390                                               TASK_UNINTERRUPTIBLE);
2391                         if (pd->bio_queue_size <= pd->write_congestion_off)
2392                                 break;
2393                         pd->congested = true;
2394                         spin_unlock(&pd->lock);
2395                         schedule();
2396                         spin_lock(&pd->lock);
2397                 }
2398         }
2399         spin_unlock(&pd->lock);
2400
2401         /*
2402          * No matching packet found. Store the bio in the work queue.
2403          */
2404         node = mempool_alloc(&pd->rb_pool, GFP_NOIO);
2405         node->bio = bio;
2406         spin_lock(&pd->lock);
2407         BUG_ON(pd->bio_queue_size < 0);
2408         was_empty = (pd->bio_queue_size == 0);
2409         pkt_rbtree_insert(pd, node);
2410         spin_unlock(&pd->lock);
2411
2412         /*
2413          * Wake up the worker thread.
2414          */
2415         atomic_set(&pd->scan_queue, 1);
2416         if (was_empty) {
2417                 /* This wake_up is required for correct operation */
2418                 wake_up(&pd->wqueue);
2419         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2420                 /*
2421                  * This wake up is not required for correct operation,
2422                  * but improves performance in some cases.
2423                  */
2424                 wake_up(&pd->wqueue);
2425         }
2426 }
2427
2428 static void pkt_submit_bio(struct bio *bio)
2429 {
2430         struct pktcdvd_device *pd = bio->bi_bdev->bd_disk->queue->queuedata;
2431         struct device *ddev = disk_to_dev(pd->disk);
2432         struct bio *split;
2433
2434         bio = bio_split_to_limits(bio);
2435         if (!bio)
2436                 return;
2437
2438         dev_dbg(ddev, "start = %6llx stop = %6llx\n",
2439                 bio->bi_iter.bi_sector, bio_end_sector(bio));
2440
2441         /*
2442          * Clone READ bios so we can have our own bi_end_io callback.
2443          */
2444         if (bio_data_dir(bio) == READ) {
2445                 pkt_make_request_read(pd, bio);
2446                 return;
2447         }
2448
2449         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2450                 dev_notice(ddev, "WRITE for ro device (%llu)\n", bio->bi_iter.bi_sector);
2451                 goto end_io;
2452         }
2453
2454         if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2455                 dev_err(ddev, "wrong bio size\n");
2456                 goto end_io;
2457         }
2458
2459         do {
2460                 sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
2461                 sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2462
2463                 if (last_zone != zone) {
2464                         BUG_ON(last_zone != zone + pd->settings.size);
2465
2466                         split = bio_split(bio, last_zone -
2467                                           bio->bi_iter.bi_sector,
2468                                           GFP_NOIO, &pkt_bio_set);
2469                         bio_chain(split, bio);
2470                 } else {
2471                         split = bio;
2472                 }
2473
2474                 pkt_make_request_write(bio->bi_bdev->bd_disk->queue, split);
2475         } while (split != bio);
2476
2477         return;
2478 end_io:
2479         bio_io_error(bio);
2480 }
2481
2482 static void pkt_init_queue(struct pktcdvd_device *pd)
2483 {
2484         struct request_queue *q = pd->disk->queue;
2485
2486         blk_queue_logical_block_size(q, CD_FRAMESIZE);
2487         blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2488         q->queuedata = pd;
2489 }
2490
2491 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2492 {
2493         struct device *ddev = disk_to_dev(pd->disk);
2494         int i;
2495         struct block_device *bdev;
2496         struct scsi_device *sdev;
2497
2498         if (pd->pkt_dev == dev) {
2499                 dev_err(ddev, "recursive setup not allowed\n");
2500                 return -EBUSY;
2501         }
2502         for (i = 0; i < MAX_WRITERS; i++) {
2503                 struct pktcdvd_device *pd2 = pkt_devs[i];
2504                 if (!pd2)
2505                         continue;
2506                 if (pd2->bdev->bd_dev == dev) {
2507                         dev_err(ddev, "%pg already setup\n", pd2->bdev);
2508                         return -EBUSY;
2509                 }
2510                 if (pd2->pkt_dev == dev) {
2511                         dev_err(ddev, "can't chain pktcdvd devices\n");
2512                         return -EBUSY;
2513                 }
2514         }
2515
2516         bdev = blkdev_get_by_dev(dev, BLK_OPEN_READ | BLK_OPEN_NDELAY, NULL,
2517                                  NULL);
2518         if (IS_ERR(bdev))
2519                 return PTR_ERR(bdev);
2520         sdev = scsi_device_from_queue(bdev->bd_disk->queue);
2521         if (!sdev) {
2522                 blkdev_put(bdev, NULL);
2523                 return -EINVAL;
2524         }
2525         put_device(&sdev->sdev_gendev);
2526
2527         /* This is safe, since we have a reference from open(). */
2528         __module_get(THIS_MODULE);
2529
2530         pd->bdev = bdev;
2531         set_blocksize(bdev, CD_FRAMESIZE);
2532
2533         pkt_init_queue(pd);
2534
2535         atomic_set(&pd->cdrw.pending_bios, 0);
2536         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->disk->disk_name);
2537         if (IS_ERR(pd->cdrw.thread)) {
2538                 dev_err(ddev, "can't start kernel thread\n");
2539                 goto out_mem;
2540         }
2541
2542         proc_create_single_data(pd->disk->disk_name, 0, pkt_proc, pkt_seq_show, pd);
2543         dev_notice(ddev, "writer mapped to %pg\n", bdev);
2544         return 0;
2545
2546 out_mem:
2547         blkdev_put(bdev, NULL);
2548         /* This is safe: open() is still holding a reference. */
2549         module_put(THIS_MODULE);
2550         return -ENOMEM;
2551 }
2552
2553 static int pkt_ioctl(struct block_device *bdev, blk_mode_t mode,
2554                 unsigned int cmd, unsigned long arg)
2555 {
2556         struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2557         struct device *ddev = disk_to_dev(pd->disk);
2558         int ret;
2559
2560         dev_dbg(ddev, "cmd %x, dev %d:%d\n", cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2561
2562         mutex_lock(&pktcdvd_mutex);
2563         switch (cmd) {
2564         case CDROMEJECT:
2565                 /*
2566                  * The door gets locked when the device is opened, so we
2567                  * have to unlock it or else the eject command fails.
2568                  */
2569                 if (pd->refcnt == 1)
2570                         pkt_lock_door(pd, 0);
2571                 fallthrough;
2572         /*
2573          * forward selected CDROM ioctls to CD-ROM, for UDF
2574          */
2575         case CDROMMULTISESSION:
2576         case CDROMREADTOCENTRY:
2577         case CDROM_LAST_WRITTEN:
2578         case CDROM_SEND_PACKET:
2579         case SCSI_IOCTL_SEND_COMMAND:
2580                 if (!bdev->bd_disk->fops->ioctl)
2581                         ret = -ENOTTY;
2582                 else
2583                         ret = bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
2584                 break;
2585         default:
2586                 dev_dbg(ddev, "Unknown ioctl (%x)\n", cmd);
2587                 ret = -ENOTTY;
2588         }
2589         mutex_unlock(&pktcdvd_mutex);
2590
2591         return ret;
2592 }
2593
2594 static unsigned int pkt_check_events(struct gendisk *disk,
2595                                      unsigned int clearing)
2596 {
2597         struct pktcdvd_device *pd = disk->private_data;
2598         struct gendisk *attached_disk;
2599
2600         if (!pd)
2601                 return 0;
2602         if (!pd->bdev)
2603                 return 0;
2604         attached_disk = pd->bdev->bd_disk;
2605         if (!attached_disk || !attached_disk->fops->check_events)
2606                 return 0;
2607         return attached_disk->fops->check_events(attached_disk, clearing);
2608 }
2609
2610 static char *pkt_devnode(struct gendisk *disk, umode_t *mode)
2611 {
2612         return kasprintf(GFP_KERNEL, "pktcdvd/%s", disk->disk_name);
2613 }
2614
2615 static const struct block_device_operations pktcdvd_ops = {
2616         .owner =                THIS_MODULE,
2617         .submit_bio =           pkt_submit_bio,
2618         .open =                 pkt_open,
2619         .release =              pkt_release,
2620         .ioctl =                pkt_ioctl,
2621         .compat_ioctl =         blkdev_compat_ptr_ioctl,
2622         .check_events =         pkt_check_events,
2623         .devnode =              pkt_devnode,
2624 };
2625
2626 /*
2627  * Set up mapping from pktcdvd device to CD-ROM device.
2628  */
2629 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2630 {
2631         int idx;
2632         int ret = -ENOMEM;
2633         struct pktcdvd_device *pd;
2634         struct gendisk *disk;
2635
2636         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2637
2638         for (idx = 0; idx < MAX_WRITERS; idx++)
2639                 if (!pkt_devs[idx])
2640                         break;
2641         if (idx == MAX_WRITERS) {
2642                 pr_err("max %d writers supported\n", MAX_WRITERS);
2643                 ret = -EBUSY;
2644                 goto out_mutex;
2645         }
2646
2647         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2648         if (!pd)
2649                 goto out_mutex;
2650
2651         ret = mempool_init_kmalloc_pool(&pd->rb_pool, PKT_RB_POOL_SIZE,
2652                                         sizeof(struct pkt_rb_node));
2653         if (ret)
2654                 goto out_mem;
2655
2656         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2657         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2658         spin_lock_init(&pd->cdrw.active_list_lock);
2659
2660         spin_lock_init(&pd->lock);
2661         spin_lock_init(&pd->iosched.lock);
2662         bio_list_init(&pd->iosched.read_queue);
2663         bio_list_init(&pd->iosched.write_queue);
2664         init_waitqueue_head(&pd->wqueue);
2665         pd->bio_queue = RB_ROOT;
2666
2667         pd->write_congestion_on  = write_congestion_on;
2668         pd->write_congestion_off = write_congestion_off;
2669
2670         ret = -ENOMEM;
2671         disk = blk_alloc_disk(NUMA_NO_NODE);
2672         if (!disk)
2673                 goto out_mem;
2674         pd->disk = disk;
2675         disk->major = pktdev_major;
2676         disk->first_minor = idx;
2677         disk->minors = 1;
2678         disk->fops = &pktcdvd_ops;
2679         disk->flags = GENHD_FL_REMOVABLE | GENHD_FL_NO_PART;
2680         snprintf(disk->disk_name, sizeof(disk->disk_name), DRIVER_NAME"%d", idx);
2681         disk->private_data = pd;
2682
2683         pd->pkt_dev = MKDEV(pktdev_major, idx);
2684         ret = pkt_new_dev(pd, dev);
2685         if (ret)
2686                 goto out_mem2;
2687
2688         /* inherit events of the host device */
2689         disk->events = pd->bdev->bd_disk->events;
2690
2691         ret = add_disk(disk);
2692         if (ret)
2693                 goto out_mem2;
2694
2695         pkt_sysfs_dev_new(pd);
2696         pkt_debugfs_dev_new(pd);
2697
2698         pkt_devs[idx] = pd;
2699         if (pkt_dev)
2700                 *pkt_dev = pd->pkt_dev;
2701
2702         mutex_unlock(&ctl_mutex);
2703         return 0;
2704
2705 out_mem2:
2706         put_disk(disk);
2707 out_mem:
2708         mempool_exit(&pd->rb_pool);
2709         kfree(pd);
2710 out_mutex:
2711         mutex_unlock(&ctl_mutex);
2712         pr_err("setup of pktcdvd device failed\n");
2713         return ret;
2714 }
2715
2716 /*
2717  * Tear down mapping from pktcdvd device to CD-ROM device.
2718  */
2719 static int pkt_remove_dev(dev_t pkt_dev)
2720 {
2721         struct pktcdvd_device *pd;
2722         struct device *ddev;
2723         int idx;
2724         int ret = 0;
2725
2726         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2727
2728         for (idx = 0; idx < MAX_WRITERS; idx++) {
2729                 pd = pkt_devs[idx];
2730                 if (pd && (pd->pkt_dev == pkt_dev))
2731                         break;
2732         }
2733         if (idx == MAX_WRITERS) {
2734                 pr_debug("dev not setup\n");
2735                 ret = -ENXIO;
2736                 goto out;
2737         }
2738
2739         if (pd->refcnt > 0) {
2740                 ret = -EBUSY;
2741                 goto out;
2742         }
2743
2744         ddev = disk_to_dev(pd->disk);
2745
2746         if (!IS_ERR(pd->cdrw.thread))
2747                 kthread_stop(pd->cdrw.thread);
2748
2749         pkt_devs[idx] = NULL;
2750
2751         pkt_debugfs_dev_remove(pd);
2752         pkt_sysfs_dev_remove(pd);
2753
2754         blkdev_put(pd->bdev, NULL);
2755
2756         remove_proc_entry(pd->disk->disk_name, pkt_proc);
2757         dev_notice(ddev, "writer unmapped\n");
2758
2759         del_gendisk(pd->disk);
2760         put_disk(pd->disk);
2761
2762         mempool_exit(&pd->rb_pool);
2763         kfree(pd);
2764
2765         /* This is safe: open() is still holding a reference. */
2766         module_put(THIS_MODULE);
2767
2768 out:
2769         mutex_unlock(&ctl_mutex);
2770         return ret;
2771 }
2772
2773 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2774 {
2775         struct pktcdvd_device *pd;
2776
2777         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2778
2779         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2780         if (pd) {
2781                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2782                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2783         } else {
2784                 ctrl_cmd->dev = 0;
2785                 ctrl_cmd->pkt_dev = 0;
2786         }
2787         ctrl_cmd->num_devices = MAX_WRITERS;
2788
2789         mutex_unlock(&ctl_mutex);
2790 }
2791
2792 static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2793 {
2794         void __user *argp = (void __user *)arg;
2795         struct pkt_ctrl_command ctrl_cmd;
2796         int ret = 0;
2797         dev_t pkt_dev = 0;
2798
2799         if (cmd != PACKET_CTRL_CMD)
2800                 return -ENOTTY;
2801
2802         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2803                 return -EFAULT;
2804
2805         switch (ctrl_cmd.command) {
2806         case PKT_CTRL_CMD_SETUP:
2807                 if (!capable(CAP_SYS_ADMIN))
2808                         return -EPERM;
2809                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2810                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2811                 break;
2812         case PKT_CTRL_CMD_TEARDOWN:
2813                 if (!capable(CAP_SYS_ADMIN))
2814                         return -EPERM;
2815                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2816                 break;
2817         case PKT_CTRL_CMD_STATUS:
2818                 pkt_get_status(&ctrl_cmd);
2819                 break;
2820         default:
2821                 return -ENOTTY;
2822         }
2823
2824         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2825                 return -EFAULT;
2826         return ret;
2827 }
2828
2829 #ifdef CONFIG_COMPAT
2830 static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2831 {
2832         return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2833 }
2834 #endif
2835
2836 static const struct file_operations pkt_ctl_fops = {
2837         .open           = nonseekable_open,
2838         .unlocked_ioctl = pkt_ctl_ioctl,
2839 #ifdef CONFIG_COMPAT
2840         .compat_ioctl   = pkt_ctl_compat_ioctl,
2841 #endif
2842         .owner          = THIS_MODULE,
2843         .llseek         = no_llseek,
2844 };
2845
2846 static struct miscdevice pkt_misc = {
2847         .minor          = MISC_DYNAMIC_MINOR,
2848         .name           = DRIVER_NAME,
2849         .nodename       = "pktcdvd/control",
2850         .fops           = &pkt_ctl_fops
2851 };
2852
2853 static int __init pkt_init(void)
2854 {
2855         int ret;
2856
2857         mutex_init(&ctl_mutex);
2858
2859         ret = mempool_init_kmalloc_pool(&psd_pool, PSD_POOL_SIZE,
2860                                     sizeof(struct packet_stacked_data));
2861         if (ret)
2862                 return ret;
2863         ret = bioset_init(&pkt_bio_set, BIO_POOL_SIZE, 0, 0);
2864         if (ret) {
2865                 mempool_exit(&psd_pool);
2866                 return ret;
2867         }
2868
2869         ret = register_blkdev(pktdev_major, DRIVER_NAME);
2870         if (ret < 0) {
2871                 pr_err("unable to register block device\n");
2872                 goto out2;
2873         }
2874         if (!pktdev_major)
2875                 pktdev_major = ret;
2876
2877         ret = pkt_sysfs_init();
2878         if (ret)
2879                 goto out;
2880
2881         pkt_debugfs_init();
2882
2883         ret = misc_register(&pkt_misc);
2884         if (ret) {
2885                 pr_err("unable to register misc device\n");
2886                 goto out_misc;
2887         }
2888
2889         pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
2890
2891         return 0;
2892
2893 out_misc:
2894         pkt_debugfs_cleanup();
2895         pkt_sysfs_cleanup();
2896 out:
2897         unregister_blkdev(pktdev_major, DRIVER_NAME);
2898 out2:
2899         mempool_exit(&psd_pool);
2900         bioset_exit(&pkt_bio_set);
2901         return ret;
2902 }
2903
2904 static void __exit pkt_exit(void)
2905 {
2906         remove_proc_entry("driver/"DRIVER_NAME, NULL);
2907         misc_deregister(&pkt_misc);
2908
2909         pkt_debugfs_cleanup();
2910         pkt_sysfs_cleanup();
2911
2912         unregister_blkdev(pktdev_major, DRIVER_NAME);
2913         mempool_exit(&psd_pool);
2914         bioset_exit(&pkt_bio_set);
2915 }
2916
2917 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
2918 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
2919 MODULE_LICENSE("GPL");
2920
2921 module_init(pkt_init);
2922 module_exit(pkt_exit);