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(file_bdev(pd->bdev_file)->bd_dev),
 344                         MINOR(file_bdev(pd->bdev_file)->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,
 441                    file_bdev(pd->bdev_file));
 442
 443         seq_printf(m, "\nSettings:\n");
 444         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
 445
 446         if (pd->settings.write_type == 0)
 447                 msg = "Packet";
 448         else
 449                 msg = "Unknown";
 450         seq_printf(m, "\twrite type:\t\t%s\n", msg);
 451
 452         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
 453         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
 454
 455         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
 456
 457         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
 458                 msg = "Mode 1";
 459         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
 460                 msg = "Mode 2";
 461         else
 462                 msg = "Unknown";
 463         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
 464
 465         seq_printf(m, "\nStatistics:\n");
 466         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
 467         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
 468         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
 469         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
 470         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
 471
 472         seq_printf(m, "\nMisc:\n");
 473         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
 474         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
 475         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
 476         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
 477         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
 478         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
 479
 480         seq_printf(m, "\nQueue state:\n");
 481         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
 482         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
 483         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", pd->current_sector);
 484
 485         pkt_count_states(pd, states);
 486         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
 487                    states[0], states[1], states[2], states[3], states[4], states[5]);
 488
 489         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
 490                         pd->write_congestion_off,
 491                         pd->write_congestion_on);
 492         return 0;
 493 }
 494 DEFINE_SHOW_ATTRIBUTE(pkt_seq);
 495
 496 static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
 497 {
 498         if (!pkt_debugfs_root)
 499                 return;
 500         pd->dfs_d_root = debugfs_create_dir(pd->disk->disk_name, pkt_debugfs_root);
 501         if (!pd->dfs_d_root)
 502                 return;
 503
 504         pd->dfs_f_info = debugfs_create_file("info", 0444, pd->dfs_d_root,
 505                                              pd, &pkt_seq_fops);
 506 }
 507
 508 static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
 509 {
 510         if (!pkt_debugfs_root)
 511                 return;
 512         debugfs_remove(pd->dfs_f_info);
 513         debugfs_remove(pd->dfs_d_root);
 514         pd->dfs_f_info = NULL;
 515         pd->dfs_d_root = NULL;
 516 }
 517
 518 static void pkt_debugfs_init(void)
 519 {
 520         pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
 521 }
 522
 523 static void pkt_debugfs_cleanup(void)
 524 {
 525         debugfs_remove(pkt_debugfs_root);
 526         pkt_debugfs_root = NULL;
 527 }
 528
 529 /* ----------------------------------------------------------*/
 530
 531
 532 static void pkt_bio_finished(struct pktcdvd_device *pd)
 533 {
 534         struct device *ddev = disk_to_dev(pd->disk);
 535
 536         BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
 537         if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
 538                 dev_dbg(ddev, "queue empty\n");
 539                 atomic_set(&pd->iosched.attention, 1);
 540                 wake_up(&pd->wqueue);
 541         }
 542 }
 543
 544 /*
 545  * Allocate a packet_data struct
 546  */
 547 static struct packet_data *pkt_alloc_packet_data(int frames)
 548 {
 549         int i;
 550         struct packet_data *pkt;
 551
 552         pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
 553         if (!pkt)
 554                 goto no_pkt;
 555
 556         pkt->frames = frames;
 557         pkt->w_bio = bio_kmalloc(frames, GFP_KERNEL);
 558         if (!pkt->w_bio)
 559                 goto no_bio;
 560
 561         for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
 562                 pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
 563                 if (!pkt->pages[i])
 564                         goto no_page;
 565         }
 566
 567         spin_lock_init(&pkt->lock);
 568         bio_list_init(&pkt->orig_bios);
 569
 570         for (i = 0; i < frames; i++) {
 571                 pkt->r_bios[i] = bio_kmalloc(1, GFP_KERNEL);
 572                 if (!pkt->r_bios[i])
 573                         goto no_rd_bio;
 574         }
 575
 576         return pkt;
 577
 578 no_rd_bio:
 579         for (i = 0; i < frames; i++)
 580                 kfree(pkt->r_bios[i]);
 581 no_page:
 582         for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
 583                 if (pkt->pages[i])
 584                         __free_page(pkt->pages[i]);
 585         kfree(pkt->w_bio);
 586 no_bio:
 587         kfree(pkt);
 588 no_pkt:
 589         return NULL;
 590 }
 591
 592 /*
 593  * Free a packet_data struct
 594  */
 595 static void pkt_free_packet_data(struct packet_data *pkt)
 596 {
 597         int i;
 598
 599         for (i = 0; i < pkt->frames; i++)
 600                 kfree(pkt->r_bios[i]);
 601         for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
 602                 __free_page(pkt->pages[i]);
 603         kfree(pkt->w_bio);
 604         kfree(pkt);
 605 }
 606
 607 static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
 608 {
 609         struct packet_data *pkt, *next;
 610
 611         BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
 612
 613         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
 614                 pkt_free_packet_data(pkt);
 615         }
 616         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
 617 }
 618
 619 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
 620 {
 621         struct packet_data *pkt;
 622
 623         BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
 624
 625         while (nr_packets > 0) {
 626                 pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
 627                 if (!pkt) {
 628                         pkt_shrink_pktlist(pd);
 629                         return 0;
 630                 }
 631                 pkt->id = nr_packets;
 632                 pkt->pd = pd;
 633                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
 634                 nr_packets--;
 635         }
 636         return 1;
 637 }
 638
 639 static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
 640 {
 641         struct rb_node *n = rb_next(&node->rb_node);
 642         if (!n)
 643                 return NULL;
 644         return rb_entry(n, struct pkt_rb_node, rb_node);
 645 }
 646
 647 static void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 648 {
 649         rb_erase(&node->rb_node, &pd->bio_queue);
 650         mempool_free(node, &pd->rb_pool);
 651         pd->bio_queue_size--;
 652         BUG_ON(pd->bio_queue_size < 0);
 653 }
 654
 655 /*
 656  * Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
 657  */
 658 static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
 659 {
 660         struct rb_node *n = pd->bio_queue.rb_node;
 661         struct rb_node *next;
 662         struct pkt_rb_node *tmp;
 663
 664         if (!n) {
 665                 BUG_ON(pd->bio_queue_size > 0);
 666                 return NULL;
 667         }
 668
 669         for (;;) {
 670                 tmp = rb_entry(n, struct pkt_rb_node, rb_node);
 671                 if (s <= tmp->bio->bi_iter.bi_sector)
 672                         next = n->rb_left;
 673                 else
 674                         next = n->rb_right;
 675                 if (!next)
 676                         break;
 677                 n = next;
 678         }
 679
 680         if (s > tmp->bio->bi_iter.bi_sector) {
 681                 tmp = pkt_rbtree_next(tmp);
 682                 if (!tmp)
 683                         return NULL;
 684         }
 685         BUG_ON(s > tmp->bio->bi_iter.bi_sector);
 686         return tmp;
 687 }
 688
 689 /*
 690  * Insert a node into the pd->bio_queue rb tree.
 691  */
 692 static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 693 {
 694         struct rb_node **p = &pd->bio_queue.rb_node;
 695         struct rb_node *parent = NULL;
 696         sector_t s = node->bio->bi_iter.bi_sector;
 697         struct pkt_rb_node *tmp;
 698
 699         while (*p) {
 700                 parent = *p;
 701                 tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
 702                 if (s < tmp->bio->bi_iter.bi_sector)
 703                         p = &(*p)->rb_left;
 704                 else
 705                         p = &(*p)->rb_right;
 706         }
 707         rb_link_node(&node->rb_node, parent, p);
 708         rb_insert_color(&node->rb_node, &pd->bio_queue);
 709         pd->bio_queue_size++;
 710 }
 711
 712 /*
 713  * Send a packet_command to the underlying block device and
 714  * wait for completion.
 715  */
 716 static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
 717 {
 718         struct request_queue *q = bdev_get_queue(file_bdev(pd->bdev_file));
 719         struct scsi_cmnd *scmd;
 720         struct request *rq;
 721         int ret = 0;
 722
 723         rq = scsi_alloc_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
 724                              REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 725         if (IS_ERR(rq))
 726                 return PTR_ERR(rq);
 727         scmd = blk_mq_rq_to_pdu(rq);
 728
 729         if (cgc->buflen) {
 730                 ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
 731                                       GFP_NOIO);
 732                 if (ret)
 733                         goto out;
 734         }
 735
 736         scmd->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
 737         memcpy(scmd->cmnd, cgc->cmd, CDROM_PACKET_SIZE);
 738
 739         rq->timeout = 60*HZ;
 740         if (cgc->quiet)
 741                 rq->rq_flags |= RQF_QUIET;
 742
 743         blk_execute_rq(rq, false);
 744         if (scmd->result)
 745                 ret = -EIO;
 746 out:
 747         blk_mq_free_request(rq);
 748         return ret;
 749 }
 750
 751 static const char *sense_key_string(__u8 index)
 752 {
 753         static const char * const info[] = {
 754                 "No sense", "Recovered error", "Not ready",
 755                 "Medium error", "Hardware error", "Illegal request",
 756                 "Unit attention", "Data protect", "Blank check",
 757         };
 758
 759         return index < ARRAY_SIZE(info) ? info[index] : "INVALID";
 760 }
 761
 762 /*
 763  * A generic sense dump / resolve mechanism should be implemented across
 764  * all ATAPI + SCSI devices.
 765  */
 766 static void pkt_dump_sense(struct pktcdvd_device *pd,
 767                            struct packet_command *cgc)
 768 {
 769         struct device *ddev = disk_to_dev(pd->disk);
 770         struct scsi_sense_hdr *sshdr = cgc->sshdr;
 771
 772         if (sshdr)
 773                 dev_err(ddev, "%*ph - sense %02x.%02x.%02x (%s)\n",
 774                         CDROM_PACKET_SIZE, cgc->cmd,
 775                         sshdr->sense_key, sshdr->asc, sshdr->ascq,
 776                         sense_key_string(sshdr->sense_key));
 777         else
 778                 dev_err(ddev, "%*ph - no sense\n", CDROM_PACKET_SIZE, cgc->cmd);
 779 }
 780
 781 /*
 782  * flush the drive cache to media
 783  */
 784 static int pkt_flush_cache(struct pktcdvd_device *pd)
 785 {
 786         struct packet_command cgc;
 787
 788         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 789         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 790         cgc.quiet = 1;
 791
 792         /*
 793          * the IMMED bit -- we default to not setting it, although that
 794          * would allow a much faster close, this is safer
 795          */
 796 #if 0
 797         cgc.cmd[1] = 1 << 1;
 798 #endif
 799         return pkt_generic_packet(pd, &cgc);
 800 }
 801
 802 /*
 803  * speed is given as the normal factor, e.g. 4 for 4x
 804  */
 805 static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
 806                                 unsigned write_speed, unsigned read_speed)
 807 {
 808         struct packet_command cgc;
 809         struct scsi_sense_hdr sshdr;
 810         int ret;
 811
 812         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 813         cgc.sshdr = &sshdr;
 814         cgc.cmd[0] = GPCMD_SET_SPEED;
 815         put_unaligned_be16(read_speed, &cgc.cmd[2]);
 816         put_unaligned_be16(write_speed, &cgc.cmd[4]);
 817
 818         ret = pkt_generic_packet(pd, &cgc);
 819         if (ret)
 820                 pkt_dump_sense(pd, &cgc);
 821
 822         return ret;
 823 }
 824
 825 /*
 826  * Queue a bio for processing by the low-level CD device. Must be called
 827  * from process context.
 828  */
 829 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 830 {
 831         /*
 832          * Some CDRW drives can not handle writes larger than one packet,
 833          * even if the size is a multiple of the packet size.
 834          */
 835         bio->bi_opf |= REQ_NOMERGE;
 836
 837         spin_lock(&pd->iosched.lock);
 838         if (bio_data_dir(bio) == READ)
 839                 bio_list_add(&pd->iosched.read_queue, bio);
 840         else
 841                 bio_list_add(&pd->iosched.write_queue, bio);
 842         spin_unlock(&pd->iosched.lock);
 843
 844         atomic_set(&pd->iosched.attention, 1);
 845         wake_up(&pd->wqueue);
 846 }
 847
 848 /*
 849  * Process the queued read/write requests. This function handles special
 850  * requirements for CDRW drives:
 851  * - A cache flush command must be inserted before a read request if the
 852  *   previous request was a write.
 853  * - Switching between reading and writing is slow, so don't do it more often
 854  *   than necessary.
 855  * - Optimize for throughput at the expense of latency. This means that streaming
 856  *   writes will never be interrupted by a read, but if the drive has to seek
 857  *   before the next write, switch to reading instead if there are any pending
 858  *   read requests.
 859  * - Set the read speed according to current usage pattern. When only reading
 860  *   from the device, it's best to use the highest possible read speed, but
 861  *   when switching often between reading and writing, it's better to have the
 862  *   same read and write speeds.
 863  */
 864 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
 865 {
 866         struct device *ddev = disk_to_dev(pd->disk);
 867
 868         if (atomic_read(&pd->iosched.attention) == 0)
 869                 return;
 870         atomic_set(&pd->iosched.attention, 0);
 871
 872         for (;;) {
 873                 struct bio *bio;
 874                 int reads_queued, writes_queued;
 875
 876                 spin_lock(&pd->iosched.lock);
 877                 reads_queued = !bio_list_empty(&pd->iosched.read_queue);
 878                 writes_queued = !bio_list_empty(&pd->iosched.write_queue);
 879                 spin_unlock(&pd->iosched.lock);
 880
 881                 if (!reads_queued && !writes_queued)
 882                         break;
 883
 884                 if (pd->iosched.writing) {
 885                         int need_write_seek = 1;
 886                         spin_lock(&pd->iosched.lock);
 887                         bio = bio_list_peek(&pd->iosched.write_queue);
 888                         spin_unlock(&pd->iosched.lock);
 889                         if (bio && (bio->bi_iter.bi_sector ==
 890                                     pd->iosched.last_write))
 891                                 need_write_seek = 0;
 892                         if (need_write_seek && reads_queued) {
 893                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 894                                         dev_dbg(ddev, "write, waiting\n");
 895                                         break;
 896                                 }
 897                                 pkt_flush_cache(pd);
 898                                 pd->iosched.writing = 0;
 899                         }
 900                 } else {
 901                         if (!reads_queued && writes_queued) {
 902                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 903                                         dev_dbg(ddev, "read, waiting\n");
 904                                         break;
 905                                 }
 906                                 pd->iosched.writing = 1;
 907                         }
 908                 }
 909
 910                 spin_lock(&pd->iosched.lock);
 911                 if (pd->iosched.writing)
 912                         bio = bio_list_pop(&pd->iosched.write_queue);
 913                 else
 914                         bio = bio_list_pop(&pd->iosched.read_queue);
 915                 spin_unlock(&pd->iosched.lock);
 916
 917                 if (!bio)
 918                         continue;
 919
 920                 if (bio_data_dir(bio) == READ)
 921                         pd->iosched.successive_reads +=
 922                                 bio->bi_iter.bi_size >> 10;
 923                 else {
 924                         pd->iosched.successive_reads = 0;
 925                         pd->iosched.last_write = bio_end_sector(bio);
 926                 }
 927                 if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
 928                         if (pd->read_speed == pd->write_speed) {
 929                                 pd->read_speed = MAX_SPEED;
 930                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 931                         }
 932                 } else {
 933                         if (pd->read_speed != pd->write_speed) {
 934                                 pd->read_speed = pd->write_speed;
 935                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 936                         }
 937                 }
 938
 939                 atomic_inc(&pd->cdrw.pending_bios);
 940                 submit_bio_noacct(bio);
 941         }
 942 }
 943
 944 /*
 945  * Special care is needed if the underlying block device has a small
 946  * max_phys_segments value.
 947  */
 948 static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
 949 {
 950         struct device *ddev = disk_to_dev(pd->disk);
 951
 952         if ((pd->settings.size << 9) / CD_FRAMESIZE <= queue_max_segments(q)) {
 953                 /*
 954                  * The cdrom device can handle one segment/frame
 955                  */
 956                 clear_bit(PACKET_MERGE_SEGS, &pd->flags);
 957                 return 0;
 958         }
 959
 960         if ((pd->settings.size << 9) / PAGE_SIZE <= queue_max_segments(q)) {
 961                 /*
 962                  * We can handle this case at the expense of some extra memory
 963                  * copies during write operations
 964                  */
 965                 set_bit(PACKET_MERGE_SEGS, &pd->flags);
 966                 return 0;
 967         }
 968
 969         dev_err(ddev, "cdrom max_phys_segments too small\n");
 970         return -EIO;
 971 }
 972
 973 static void pkt_end_io_read(struct bio *bio)
 974 {
 975         struct packet_data *pkt = bio->bi_private;
 976         struct pktcdvd_device *pd = pkt->pd;
 977         BUG_ON(!pd);
 978
 979         dev_dbg(disk_to_dev(pd->disk), "bio=%p sec0=%llx sec=%llx err=%d\n",
 980                 bio, pkt->sector, bio->bi_iter.bi_sector, bio->bi_status);
 981
 982         if (bio->bi_status)
 983                 atomic_inc(&pkt->io_errors);
 984         bio_uninit(bio);
 985         if (atomic_dec_and_test(&pkt->io_wait)) {
 986                 atomic_inc(&pkt->run_sm);
 987                 wake_up(&pd->wqueue);
 988         }
 989         pkt_bio_finished(pd);
 990 }
 991
 992 static void pkt_end_io_packet_write(struct bio *bio)
 993 {
 994         struct packet_data *pkt = bio->bi_private;
 995         struct pktcdvd_device *pd = pkt->pd;
 996         BUG_ON(!pd);
 997
 998         dev_dbg(disk_to_dev(pd->disk), "id=%d, err=%d\n", pkt->id, bio->bi_status);
 999
1000         pd->stats.pkt_ended++;
1001
1002         bio_uninit(bio);
1003         pkt_bio_finished(pd);
1004         atomic_dec(&pkt->io_wait);
1005         atomic_inc(&pkt->run_sm);
1006         wake_up(&pd->wqueue);
1007 }
1008
1009 /*
1010  * Schedule reads for the holes in a packet
1011  */
1012 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1013 {
1014         struct device *ddev = disk_to_dev(pd->disk);
1015         int frames_read = 0;
1016         struct bio *bio;
1017         int f;
1018         char written[PACKET_MAX_SIZE];
1019
1020         BUG_ON(bio_list_empty(&pkt->orig_bios));
1021
1022         atomic_set(&pkt->io_wait, 0);
1023         atomic_set(&pkt->io_errors, 0);
1024
1025         /*
1026          * Figure out which frames we need to read before we can write.
1027          */
1028         memset(written, 0, sizeof(written));
1029         spin_lock(&pkt->lock);
1030         bio_list_for_each(bio, &pkt->orig_bios) {
1031                 int first_frame = (bio->bi_iter.bi_sector - pkt->sector) /
1032                         (CD_FRAMESIZE >> 9);
1033                 int num_frames = bio->bi_iter.bi_size / CD_FRAMESIZE;
1034                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1035                 BUG_ON(first_frame < 0);
1036                 BUG_ON(first_frame + num_frames > pkt->frames);
1037                 for (f = first_frame; f < first_frame + num_frames; f++)
1038                         written[f] = 1;
1039         }
1040         spin_unlock(&pkt->lock);
1041
1042         if (pkt->cache_valid) {
1043                 dev_dbg(ddev, "zone %llx cached\n", pkt->sector);
1044                 goto out_account;
1045         }
1046
1047         /*
1048          * Schedule reads for missing parts of the packet.
1049          */
1050         for (f = 0; f < pkt->frames; f++) {
1051                 int p, offset;
1052
1053                 if (written[f])
1054                         continue;
1055
1056                 bio = pkt->r_bios[f];
1057                 bio_init(bio, file_bdev(pd->bdev_file), bio->bi_inline_vecs, 1,
1058                          REQ_OP_READ);
1059                 bio->bi_iter.bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1060                 bio->bi_end_io = pkt_end_io_read;
1061                 bio->bi_private = pkt;
1062
1063                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1064                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1065                 dev_dbg(ddev, "Adding frame %d, page:%p offs:%d\n", f,
1066                         pkt->pages[p], offset);
1067                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1068                         BUG();
1069
1070                 atomic_inc(&pkt->io_wait);
1071                 pkt_queue_bio(pd, bio);
1072                 frames_read++;
1073         }
1074
1075 out_account:
1076         dev_dbg(ddev, "need %d frames for zone %llx\n", frames_read, pkt->sector);
1077         pd->stats.pkt_started++;
1078         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1079 }
1080
1081 /*
1082  * Find a packet matching zone, or the least recently used packet if
1083  * there is no match.
1084  */
1085 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1086 {
1087         struct packet_data *pkt;
1088
1089         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1090                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1091                         list_del_init(&pkt->list);
1092                         if (pkt->sector != zone)
1093                                 pkt->cache_valid = 0;
1094                         return pkt;
1095                 }
1096         }
1097         BUG();
1098         return NULL;
1099 }
1100
1101 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1102 {
1103         if (pkt->cache_valid) {
1104                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1105         } else {
1106                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1107         }
1108 }
1109
1110 static inline void pkt_set_state(struct device *ddev, struct packet_data *pkt,
1111                                  enum packet_data_state state)
1112 {
1113         static const char *state_name[] = {
1114                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1115         };
1116         enum packet_data_state old_state = pkt->state;
1117
1118         dev_dbg(ddev, "pkt %2d : s=%6llx %s -> %s\n",
1119                 pkt->id, pkt->sector, state_name[old_state], state_name[state]);
1120
1121         pkt->state = state;
1122 }
1123
1124 /*
1125  * Scan the work queue to see if we can start a new packet.
1126  * returns non-zero if any work was done.
1127  */
1128 static int pkt_handle_queue(struct pktcdvd_device *pd)
1129 {
1130         struct device *ddev = disk_to_dev(pd->disk);
1131         struct packet_data *pkt, *p;
1132         struct bio *bio = NULL;
1133         sector_t zone = 0; /* Suppress gcc warning */
1134         struct pkt_rb_node *node, *first_node;
1135         struct rb_node *n;
1136
1137         atomic_set(&pd->scan_queue, 0);
1138
1139         if (list_empty(&pd->cdrw.pkt_free_list)) {
1140                 dev_dbg(ddev, "no pkt\n");
1141                 return 0;
1142         }
1143
1144         /*
1145          * Try to find a zone we are not already working on.
1146          */
1147         spin_lock(&pd->lock);
1148         first_node = pkt_rbtree_find(pd, pd->current_sector);
1149         if (!first_node) {
1150                 n = rb_first(&pd->bio_queue);
1151                 if (n)
1152                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1153         }
1154         node = first_node;
1155         while (node) {
1156                 bio = node->bio;
1157                 zone = get_zone(bio->bi_iter.bi_sector, pd);
1158                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1159                         if (p->sector == zone) {
1160                                 bio = NULL;
1161                                 goto try_next_bio;
1162                         }
1163                 }
1164                 break;
1165 try_next_bio:
1166                 node = pkt_rbtree_next(node);
1167                 if (!node) {
1168                         n = rb_first(&pd->bio_queue);
1169                         if (n)
1170                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1171                 }
1172                 if (node == first_node)
1173                         node = NULL;
1174         }
1175         spin_unlock(&pd->lock);
1176         if (!bio) {
1177                 dev_dbg(ddev, "no bio\n");
1178                 return 0;
1179         }
1180
1181         pkt = pkt_get_packet_data(pd, zone);
1182
1183         pd->current_sector = zone + pd->settings.size;
1184         pkt->sector = zone;
1185         BUG_ON(pkt->frames != pd->settings.size >> 2);
1186         pkt->write_size = 0;
1187
1188         /*
1189          * Scan work queue for bios in the same zone and link them
1190          * to this packet.
1191          */
1192         spin_lock(&pd->lock);
1193         dev_dbg(ddev, "looking for zone %llx\n", zone);
1194         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1195                 sector_t tmp = get_zone(node->bio->bi_iter.bi_sector, pd);
1196
1197                 bio = node->bio;
1198                 dev_dbg(ddev, "found zone=%llx\n", tmp);
1199                 if (tmp != zone)
1200                         break;
1201                 pkt_rbtree_erase(pd, node);
1202                 spin_lock(&pkt->lock);
1203                 bio_list_add(&pkt->orig_bios, bio);
1204                 pkt->write_size += bio->bi_iter.bi_size / CD_FRAMESIZE;
1205                 spin_unlock(&pkt->lock);
1206         }
1207         /* check write congestion marks, and if bio_queue_size is
1208          * below, wake up any waiters
1209          */
1210         if (pd->congested &&
1211             pd->bio_queue_size <= pd->write_congestion_off) {
1212                 pd->congested = false;
1213                 wake_up_var(&pd->congested);
1214         }
1215         spin_unlock(&pd->lock);
1216
1217         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1218         pkt_set_state(ddev, pkt, PACKET_WAITING_STATE);
1219         atomic_set(&pkt->run_sm, 1);
1220
1221         spin_lock(&pd->cdrw.active_list_lock);
1222         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1223         spin_unlock(&pd->cdrw.active_list_lock);
1224
1225         return 1;
1226 }
1227
1228 /**
1229  * bio_list_copy_data - copy contents of data buffers from one chain of bios to
1230  * another
1231  * @src: source bio list
1232  * @dst: destination bio list
1233  *
1234  * Stops when it reaches the end of either the @src list or @dst list - that is,
1235  * copies min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of
1236  * bios).
1237  */
1238 static void bio_list_copy_data(struct bio *dst, struct bio *src)
1239 {
1240         struct bvec_iter src_iter = src->bi_iter;
1241         struct bvec_iter dst_iter = dst->bi_iter;
1242
1243         while (1) {
1244                 if (!src_iter.bi_size) {
1245                         src = src->bi_next;
1246                         if (!src)
1247                                 break;
1248
1249                         src_iter = src->bi_iter;
1250                 }
1251
1252                 if (!dst_iter.bi_size) {
1253                         dst = dst->bi_next;
1254                         if (!dst)
1255                                 break;
1256
1257                         dst_iter = dst->bi_iter;
1258                 }
1259
1260                 bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
1261         }
1262 }
1263
1264 /*
1265  * Assemble a bio to write one packet and queue the bio for processing
1266  * by the underlying block device.
1267  */
1268 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1269 {
1270         struct device *ddev = disk_to_dev(pd->disk);
1271         int f;
1272
1273         bio_init(pkt->w_bio, file_bdev(pd->bdev_file), pkt->w_bio->bi_inline_vecs,
1274                  pkt->frames, REQ_OP_WRITE);
1275         pkt->w_bio->bi_iter.bi_sector = pkt->sector;
1276         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1277         pkt->w_bio->bi_private = pkt;
1278
1279         /* XXX: locking? */
1280         for (f = 0; f < pkt->frames; f++) {
1281                 struct page *page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1282                 unsigned offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1283
1284                 if (!bio_add_page(pkt->w_bio, page, CD_FRAMESIZE, offset))
1285                         BUG();
1286         }
1287         dev_dbg(ddev, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
1288
1289         /*
1290          * Fill-in bvec with data from orig_bios.
1291          */
1292         spin_lock(&pkt->lock);
1293         bio_list_copy_data(pkt->w_bio, pkt->orig_bios.head);
1294
1295         pkt_set_state(ddev, pkt, PACKET_WRITE_WAIT_STATE);
1296         spin_unlock(&pkt->lock);
1297
1298         dev_dbg(ddev, "Writing %d frames for zone %llx\n", pkt->write_size, pkt->sector);
1299
1300         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames))
1301                 pkt->cache_valid = 1;
1302         else
1303                 pkt->cache_valid = 0;
1304
1305         /* Start the write request */
1306         atomic_set(&pkt->io_wait, 1);
1307         pkt_queue_bio(pd, pkt->w_bio);
1308 }
1309
1310 static void pkt_finish_packet(struct packet_data *pkt, blk_status_t status)
1311 {
1312         struct bio *bio;
1313
1314         if (status)
1315                 pkt->cache_valid = 0;
1316
1317         /* Finish all bios corresponding to this packet */
1318         while ((bio = bio_list_pop(&pkt->orig_bios))) {
1319                 bio->bi_status = status;
1320                 bio_endio(bio);
1321         }
1322 }
1323
1324 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1325 {
1326         struct device *ddev = disk_to_dev(pd->disk);
1327
1328         dev_dbg(ddev, "pkt %d\n", pkt->id);
1329
1330         for (;;) {
1331                 switch (pkt->state) {
1332                 case PACKET_WAITING_STATE:
1333                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1334                                 return;
1335
1336                         pkt->sleep_time = 0;
1337                         pkt_gather_data(pd, pkt);
1338                         pkt_set_state(ddev, pkt, PACKET_READ_WAIT_STATE);
1339                         break;
1340
1341                 case PACKET_READ_WAIT_STATE:
1342                         if (atomic_read(&pkt->io_wait) > 0)
1343                                 return;
1344
1345                         if (atomic_read(&pkt->io_errors) > 0) {
1346                                 pkt_set_state(ddev, pkt, PACKET_RECOVERY_STATE);
1347                         } else {
1348                                 pkt_start_write(pd, pkt);
1349                         }
1350                         break;
1351
1352                 case PACKET_WRITE_WAIT_STATE:
1353                         if (atomic_read(&pkt->io_wait) > 0)
1354                                 return;
1355
1356                         if (!pkt->w_bio->bi_status) {
1357                                 pkt_set_state(ddev, pkt, PACKET_FINISHED_STATE);
1358                         } else {
1359                                 pkt_set_state(ddev, pkt, PACKET_RECOVERY_STATE);
1360                         }
1361                         break;
1362
1363                 case PACKET_RECOVERY_STATE:
1364                         dev_dbg(ddev, "No recovery possible\n");
1365                         pkt_set_state(ddev, pkt, PACKET_FINISHED_STATE);
1366                         break;
1367
1368                 case PACKET_FINISHED_STATE:
1369                         pkt_finish_packet(pkt, pkt->w_bio->bi_status);
1370                         return;
1371
1372                 default:
1373                         BUG();
1374                         break;
1375                 }
1376         }
1377 }
1378
1379 static void pkt_handle_packets(struct pktcdvd_device *pd)
1380 {
1381         struct device *ddev = disk_to_dev(pd->disk);
1382         struct packet_data *pkt, *next;
1383
1384         /*
1385          * Run state machine for active packets
1386          */
1387         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1388                 if (atomic_read(&pkt->run_sm) > 0) {
1389                         atomic_set(&pkt->run_sm, 0);
1390                         pkt_run_state_machine(pd, pkt);
1391                 }
1392         }
1393
1394         /*
1395          * Move no longer active packets to the free list
1396          */
1397         spin_lock(&pd->cdrw.active_list_lock);
1398         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1399                 if (pkt->state == PACKET_FINISHED_STATE) {
1400                         list_del(&pkt->list);
1401                         pkt_put_packet_data(pd, pkt);
1402                         pkt_set_state(ddev, pkt, PACKET_IDLE_STATE);
1403                         atomic_set(&pd->scan_queue, 1);
1404                 }
1405         }
1406         spin_unlock(&pd->cdrw.active_list_lock);
1407 }
1408
1409 /*
1410  * kcdrwd is woken up when writes have been queued for one of our
1411  * registered devices
1412  */
1413 static int kcdrwd(void *foobar)
1414 {
1415         struct pktcdvd_device *pd = foobar;
1416         struct device *ddev = disk_to_dev(pd->disk);
1417         struct packet_data *pkt;
1418         int states[PACKET_NUM_STATES];
1419         long min_sleep_time, residue;
1420
1421         set_user_nice(current, MIN_NICE);
1422         set_freezable();
1423
1424         for (;;) {
1425                 DECLARE_WAITQUEUE(wait, current);
1426
1427                 /*
1428                  * Wait until there is something to do
1429                  */
1430                 add_wait_queue(&pd->wqueue, &wait);
1431                 for (;;) {
1432                         set_current_state(TASK_INTERRUPTIBLE);
1433
1434                         /* Check if we need to run pkt_handle_queue */
1435                         if (atomic_read(&pd->scan_queue) > 0)
1436                                 goto work_to_do;
1437
1438                         /* Check if we need to run the state machine for some packet */
1439                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1440                                 if (atomic_read(&pkt->run_sm) > 0)
1441                                         goto work_to_do;
1442                         }
1443
1444                         /* Check if we need to process the iosched queues */
1445                         if (atomic_read(&pd->iosched.attention) != 0)
1446                                 goto work_to_do;
1447
1448                         /* Otherwise, go to sleep */
1449                         pkt_count_states(pd, states);
1450                         dev_dbg(ddev, "i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1451                                 states[0], states[1], states[2], states[3], states[4], states[5]);
1452
1453                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1454                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1455                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1456                                         min_sleep_time = pkt->sleep_time;
1457                         }
1458
1459                         dev_dbg(ddev, "sleeping\n");
1460                         residue = schedule_timeout(min_sleep_time);
1461                         dev_dbg(ddev, "wake up\n");
1462
1463                         /* make swsusp happy with our thread */
1464                         try_to_freeze();
1465
1466                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1467                                 if (!pkt->sleep_time)
1468                                         continue;
1469                                 pkt->sleep_time -= min_sleep_time - residue;
1470                                 if (pkt->sleep_time <= 0) {
1471                                         pkt->sleep_time = 0;
1472                                         atomic_inc(&pkt->run_sm);
1473                                 }
1474                         }
1475
1476                         if (kthread_should_stop())
1477                                 break;
1478                 }
1479 work_to_do:
1480                 set_current_state(TASK_RUNNING);
1481                 remove_wait_queue(&pd->wqueue, &wait);
1482
1483                 if (kthread_should_stop())
1484                         break;
1485
1486                 /*
1487                  * if pkt_handle_queue returns true, we can queue
1488                  * another request.
1489                  */
1490                 while (pkt_handle_queue(pd))
1491                         ;
1492
1493                 /*
1494                  * Handle packet state machine
1495                  */
1496                 pkt_handle_packets(pd);
1497
1498                 /*
1499                  * Handle iosched queues
1500                  */
1501                 pkt_iosched_process_queue(pd);
1502         }
1503
1504         return 0;
1505 }
1506
1507 static void pkt_print_settings(struct pktcdvd_device *pd)
1508 {
1509         dev_info(disk_to_dev(pd->disk), "%s packets, %u blocks, Mode-%c disc\n",
1510                  pd->settings.fp ? "Fixed" : "Variable",
1511                  pd->settings.size >> 2,
1512                  pd->settings.block_mode == 8 ? '1' : '2');
1513 }
1514
1515 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1516 {
1517         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1518
1519         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1520         cgc->cmd[2] = page_code | (page_control << 6);
1521         put_unaligned_be16(cgc->buflen, &cgc->cmd[7]);
1522         cgc->data_direction = CGC_DATA_READ;
1523         return pkt_generic_packet(pd, cgc);
1524 }
1525
1526 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1527 {
1528         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1529         memset(cgc->buffer, 0, 2);
1530         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1531         cgc->cmd[1] = 0x10;             /* PF */
1532         put_unaligned_be16(cgc->buflen, &cgc->cmd[7]);
1533         cgc->data_direction = CGC_DATA_WRITE;
1534         return pkt_generic_packet(pd, cgc);
1535 }
1536
1537 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1538 {
1539         struct packet_command cgc;
1540         int ret;
1541
1542         /* set up command and get the disc info */
1543         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1544         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1545         cgc.cmd[8] = cgc.buflen = 2;
1546         cgc.quiet = 1;
1547
1548         ret = pkt_generic_packet(pd, &cgc);
1549         if (ret)
1550                 return ret;
1551
1552         /* not all drives have the same disc_info length, so requeue
1553          * packet with the length the drive tells us it can supply
1554          */
1555         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1556                      sizeof(di->disc_information_length);
1557
1558         if (cgc.buflen > sizeof(disc_information))
1559                 cgc.buflen = sizeof(disc_information);
1560
1561         cgc.cmd[8] = cgc.buflen;
1562         return pkt_generic_packet(pd, &cgc);
1563 }
1564
1565 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1566 {
1567         struct packet_command cgc;
1568         int ret;
1569
1570         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1571         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1572         cgc.cmd[1] = type & 3;
1573         put_unaligned_be16(track, &cgc.cmd[4]);
1574         cgc.cmd[8] = 8;
1575         cgc.quiet = 1;
1576
1577         ret = pkt_generic_packet(pd, &cgc);
1578         if (ret)
1579                 return ret;
1580
1581         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1582                      sizeof(ti->track_information_length);
1583
1584         if (cgc.buflen > sizeof(track_information))
1585                 cgc.buflen = sizeof(track_information);
1586
1587         cgc.cmd[8] = cgc.buflen;
1588         return pkt_generic_packet(pd, &cgc);
1589 }
1590
1591 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1592                                                 long *last_written)
1593 {
1594         disc_information di;
1595         track_information ti;
1596         __u32 last_track;
1597         int ret;
1598
1599         ret = pkt_get_disc_info(pd, &di);
1600         if (ret)
1601                 return ret;
1602
1603         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1604         ret = pkt_get_track_info(pd, last_track, 1, &ti);
1605         if (ret)
1606                 return ret;
1607
1608         /* if this track is blank, try the previous. */
1609         if (ti.blank) {
1610                 last_track--;
1611                 ret = pkt_get_track_info(pd, last_track, 1, &ti);
1612                 if (ret)
1613                         return ret;
1614         }
1615
1616         /* if last recorded field is valid, return it. */
1617         if (ti.lra_v) {
1618                 *last_written = be32_to_cpu(ti.last_rec_address);
1619         } else {
1620                 /* make it up instead */
1621                 *last_written = be32_to_cpu(ti.track_start) +
1622                                 be32_to_cpu(ti.track_size);
1623                 if (ti.free_blocks)
1624                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1625         }
1626         return 0;
1627 }
1628
1629 /*
1630  * write mode select package based on pd->settings
1631  */
1632 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1633 {
1634         struct device *ddev = disk_to_dev(pd->disk);
1635         struct packet_command cgc;
1636         struct scsi_sense_hdr sshdr;
1637         write_param_page *wp;
1638         char buffer[128];
1639         int ret, size;
1640
1641         /* doesn't apply to DVD+RW or DVD-RAM */
1642         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1643                 return 0;
1644
1645         memset(buffer, 0, sizeof(buffer));
1646         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1647         cgc.sshdr = &sshdr;
1648         ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1649         if (ret) {
1650                 pkt_dump_sense(pd, &cgc);
1651                 return ret;
1652         }
1653
1654         size = 2 + get_unaligned_be16(&buffer[0]);
1655         pd->mode_offset = get_unaligned_be16(&buffer[6]);
1656         if (size > sizeof(buffer))
1657                 size = sizeof(buffer);
1658
1659         /*
1660          * now get it all
1661          */
1662         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1663         cgc.sshdr = &sshdr;
1664         ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1665         if (ret) {
1666                 pkt_dump_sense(pd, &cgc);
1667                 return ret;
1668         }
1669
1670         /*
1671          * write page is offset header + block descriptor length
1672          */
1673         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1674
1675         wp->fp = pd->settings.fp;
1676         wp->track_mode = pd->settings.track_mode;
1677         wp->write_type = pd->settings.write_type;
1678         wp->data_block_type = pd->settings.block_mode;
1679
1680         wp->multi_session = 0;
1681
1682 #ifdef PACKET_USE_LS
1683         wp->link_size = 7;
1684         wp->ls_v = 1;
1685 #endif
1686
1687         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1688                 wp->session_format = 0;
1689                 wp->subhdr2 = 0x20;
1690         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1691                 wp->session_format = 0x20;
1692                 wp->subhdr2 = 8;
1693 #if 0
1694                 wp->mcn[0] = 0x80;
1695                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1696 #endif
1697         } else {
1698                 /*
1699                  * paranoia
1700                  */
1701                 dev_err(ddev, "write mode wrong %d\n", wp->data_block_type);
1702                 return 1;
1703         }
1704         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1705
1706         cgc.buflen = cgc.cmd[8] = size;
1707         ret = pkt_mode_select(pd, &cgc);
1708         if (ret) {
1709                 pkt_dump_sense(pd, &cgc);
1710                 return ret;
1711         }
1712
1713         pkt_print_settings(pd);
1714         return 0;
1715 }
1716
1717 /*
1718  * 1 -- we can write to this track, 0 -- we can't
1719  */
1720 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1721 {
1722         struct device *ddev = disk_to_dev(pd->disk);
1723
1724         switch (pd->mmc3_profile) {
1725                 case 0x1a: /* DVD+RW */
1726                 case 0x12: /* DVD-RAM */
1727                         /* The track is always writable on DVD+RW/DVD-RAM */
1728                         return 1;
1729                 default:
1730                         break;
1731         }
1732
1733         if (!ti->packet || !ti->fp)
1734                 return 0;
1735
1736         /*
1737          * "good" settings as per Mt Fuji.
1738          */
1739         if (ti->rt == 0 && ti->blank == 0)
1740                 return 1;
1741
1742         if (ti->rt == 0 && ti->blank == 1)
1743                 return 1;
1744
1745         if (ti->rt == 1 && ti->blank == 0)
1746                 return 1;
1747
1748         dev_err(ddev, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1749         return 0;
1750 }
1751
1752 /*
1753  * 1 -- we can write to this disc, 0 -- we can't
1754  */
1755 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1756 {
1757         struct device *ddev = disk_to_dev(pd->disk);
1758
1759         switch (pd->mmc3_profile) {
1760                 case 0x0a: /* CD-RW */
1761                 case 0xffff: /* MMC3 not supported */
1762                         break;
1763                 case 0x1a: /* DVD+RW */
1764                 case 0x13: /* DVD-RW */
1765                 case 0x12: /* DVD-RAM */
1766                         return 1;
1767                 default:
1768                         dev_dbg(ddev, "Wrong disc profile (%x)\n", pd->mmc3_profile);
1769                         return 0;
1770         }
1771
1772         /*
1773          * for disc type 0xff we should probably reserve a new track.
1774          * but i'm not sure, should we leave this to user apps? probably.
1775          */
1776         if (di->disc_type == 0xff) {
1777                 dev_notice(ddev, "unknown disc - no track?\n");
1778                 return 0;
1779         }
1780
1781         if (di->disc_type != 0x20 && di->disc_type != 0) {
1782                 dev_err(ddev, "wrong disc type (%x)\n", di->disc_type);
1783                 return 0;
1784         }
1785
1786         if (di->erasable == 0) {
1787                 dev_err(ddev, "disc not erasable\n");
1788                 return 0;
1789         }
1790
1791         if (di->border_status == PACKET_SESSION_RESERVED) {
1792                 dev_err(ddev, "can't write to last track (reserved)\n");
1793                 return 0;
1794         }
1795
1796         return 1;
1797 }
1798
1799 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1800 {
1801         struct device *ddev = disk_to_dev(pd->disk);
1802         struct packet_command cgc;
1803         unsigned char buf[12];
1804         disc_information di;
1805         track_information ti;
1806         int ret, track;
1807
1808         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1809         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1810         cgc.cmd[8] = 8;
1811         ret = pkt_generic_packet(pd, &cgc);
1812         pd->mmc3_profile = ret ? 0xffff : get_unaligned_be16(&buf[6]);
1813
1814         memset(&di, 0, sizeof(disc_information));
1815         memset(&ti, 0, sizeof(track_information));
1816
1817         ret = pkt_get_disc_info(pd, &di);
1818         if (ret) {
1819                 dev_err(ddev, "failed get_disc\n");
1820                 return ret;
1821         }
1822
1823         if (!pkt_writable_disc(pd, &di))
1824                 return -EROFS;
1825
1826         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1827
1828         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1829         ret = pkt_get_track_info(pd, track, 1, &ti);
1830         if (ret) {
1831                 dev_err(ddev, "failed get_track\n");
1832                 return ret;
1833         }
1834
1835         if (!pkt_writable_track(pd, &ti)) {
1836                 dev_err(ddev, "can't write to this track\n");
1837                 return -EROFS;
1838         }
1839
1840         /*
1841          * we keep packet size in 512 byte units, makes it easier to
1842          * deal with request calculations.
1843          */
1844         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1845         if (pd->settings.size == 0) {
1846                 dev_notice(ddev, "detected zero packet size!\n");
1847                 return -ENXIO;
1848         }
1849         if (pd->settings.size > PACKET_MAX_SECTORS) {
1850                 dev_err(ddev, "packet size is too big\n");
1851                 return -EROFS;
1852         }
1853         pd->settings.fp = ti.fp;
1854         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1855
1856         if (ti.nwa_v) {
1857                 pd->nwa = be32_to_cpu(ti.next_writable);
1858                 set_bit(PACKET_NWA_VALID, &pd->flags);
1859         }
1860
1861         /*
1862          * in theory we could use lra on -RW media as well and just zero
1863          * blocks that haven't been written yet, but in practice that
1864          * is just a no-go. we'll use that for -R, naturally.
1865          */
1866         if (ti.lra_v) {
1867                 pd->lra = be32_to_cpu(ti.last_rec_address);
1868                 set_bit(PACKET_LRA_VALID, &pd->flags);
1869         } else {
1870                 pd->lra = 0xffffffff;
1871                 set_bit(PACKET_LRA_VALID, &pd->flags);
1872         }
1873
1874         /*
1875          * fine for now
1876          */
1877         pd->settings.link_loss = 7;
1878         pd->settings.write_type = 0;    /* packet */
1879         pd->settings.track_mode = ti.track_mode;
1880
1881         /*
1882          * mode1 or mode2 disc
1883          */
1884         switch (ti.data_mode) {
1885                 case PACKET_MODE1:
1886                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
1887                         break;
1888                 case PACKET_MODE2:
1889                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
1890                         break;
1891                 default:
1892                         dev_err(ddev, "unknown data mode\n");
1893                         return -EROFS;
1894         }
1895         return 0;
1896 }
1897
1898 /*
1899  * enable/disable write caching on drive
1900  */
1901 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd)
1902 {
1903         struct device *ddev = disk_to_dev(pd->disk);
1904         struct packet_command cgc;
1905         struct scsi_sense_hdr sshdr;
1906         unsigned char buf[64];
1907         bool set = IS_ENABLED(CONFIG_CDROM_PKTCDVD_WCACHE);
1908         int ret;
1909
1910         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1911         cgc.sshdr = &sshdr;
1912         cgc.buflen = pd->mode_offset + 12;
1913
1914         /*
1915          * caching mode page might not be there, so quiet this command
1916          */
1917         cgc.quiet = 1;
1918
1919         ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0);
1920         if (ret)
1921                 return ret;
1922
1923         /*
1924          * use drive write caching -- we need deferred error handling to be
1925          * able to successfully recover with this option (drive will return good
1926          * status as soon as the cdb is validated).
1927          */
1928         buf[pd->mode_offset + 10] |= (set << 2);
1929
1930         cgc.buflen = cgc.cmd[8] = 2 + get_unaligned_be16(&buf[0]);
1931         ret = pkt_mode_select(pd, &cgc);
1932         if (ret) {
1933                 dev_err(ddev, "write caching control failed\n");
1934                 pkt_dump_sense(pd, &cgc);
1935         } else if (!ret && set)
1936                 dev_notice(ddev, "enabled write caching\n");
1937         return ret;
1938 }
1939
1940 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1941 {
1942         struct packet_command cgc;
1943
1944         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1945         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1946         cgc.cmd[4] = lockflag ? 1 : 0;
1947         return pkt_generic_packet(pd, &cgc);
1948 }
1949
1950 /*
1951  * Returns drive maximum write speed
1952  */
1953 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1954                                                 unsigned *write_speed)
1955 {
1956         struct packet_command cgc;
1957         struct scsi_sense_hdr sshdr;
1958         unsigned char buf[256+18];
1959         unsigned char *cap_buf;
1960         int ret, offset;
1961
1962         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1963         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1964         cgc.sshdr = &sshdr;
1965
1966         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1967         if (ret) {
1968                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
1969                              sizeof(struct mode_page_header);
1970                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1971                 if (ret) {
1972                         pkt_dump_sense(pd, &cgc);
1973                         return ret;
1974                 }
1975         }
1976
1977         offset = 20;                        /* Obsoleted field, used by older drives */
1978         if (cap_buf[1] >= 28)
1979                 offset = 28;                /* Current write speed selected */
1980         if (cap_buf[1] >= 30) {
1981                 /* If the drive reports at least one "Logical Unit Write
1982                  * Speed Performance Descriptor Block", use the information
1983                  * in the first block. (contains the highest speed)
1984                  */
1985                 int num_spdb = get_unaligned_be16(&cap_buf[30]);
1986                 if (num_spdb > 0)
1987                         offset = 34;
1988         }
1989
1990         *write_speed = get_unaligned_be16(&cap_buf[offset]);
1991         return 0;
1992 }
1993
1994 /* These tables from cdrecord - I don't have orange book */
1995 /* standard speed CD-RW (1-4x) */
1996 static char clv_to_speed[16] = {
1997         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1998            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1999 };
2000 /* high speed CD-RW (-10x) */
2001 static char hs_clv_to_speed[16] = {
2002         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2003            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2004 };
2005 /* ultra high speed CD-RW */
2006 static char us_clv_to_speed[16] = {
2007         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2008            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2009 };
2010
2011 /*
2012  * reads the maximum media speed from ATIP
2013  */
2014 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2015                                                 unsigned *speed)
2016 {
2017         struct device *ddev = disk_to_dev(pd->disk);
2018         struct packet_command cgc;
2019         struct scsi_sense_hdr sshdr;
2020         unsigned char buf[64];
2021         unsigned int size, st, sp;
2022         int ret;
2023
2024         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2025         cgc.sshdr = &sshdr;
2026         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2027         cgc.cmd[1] = 2;
2028         cgc.cmd[2] = 4; /* READ ATIP */
2029         cgc.cmd[8] = 2;
2030         ret = pkt_generic_packet(pd, &cgc);
2031         if (ret) {
2032                 pkt_dump_sense(pd, &cgc);
2033                 return ret;
2034         }
2035         size = 2 + get_unaligned_be16(&buf[0]);
2036         if (size > sizeof(buf))
2037                 size = sizeof(buf);
2038
2039         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2040         cgc.sshdr = &sshdr;
2041         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2042         cgc.cmd[1] = 2;
2043         cgc.cmd[2] = 4;
2044         cgc.cmd[8] = size;
2045         ret = pkt_generic_packet(pd, &cgc);
2046         if (ret) {
2047                 pkt_dump_sense(pd, &cgc);
2048                 return ret;
2049         }
2050
2051         if (!(buf[6] & 0x40)) {
2052                 dev_notice(ddev, "disc type is not CD-RW\n");
2053                 return 1;
2054         }
2055         if (!(buf[6] & 0x4)) {
2056                 dev_notice(ddev, "A1 values on media are not valid, maybe not CDRW?\n");
2057                 return 1;
2058         }
2059
2060         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2061
2062         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2063
2064         /* Info from cdrecord */
2065         switch (st) {
2066                 case 0: /* standard speed */
2067                         *speed = clv_to_speed[sp];
2068                         break;
2069                 case 1: /* high speed */
2070                         *speed = hs_clv_to_speed[sp];
2071                         break;
2072                 case 2: /* ultra high speed */
2073                         *speed = us_clv_to_speed[sp];
2074                         break;
2075                 default:
2076                         dev_notice(ddev, "unknown disc sub-type %d\n", st);
2077                         return 1;
2078         }
2079         if (*speed) {
2080                 dev_info(ddev, "maximum media speed: %d\n", *speed);
2081                 return 0;
2082         } else {
2083                 dev_notice(ddev, "unknown speed %d for sub-type %d\n", sp, st);
2084                 return 1;
2085         }
2086 }
2087
2088 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2089 {
2090         struct device *ddev = disk_to_dev(pd->disk);
2091         struct packet_command cgc;
2092         struct scsi_sense_hdr sshdr;
2093         int ret;
2094
2095         dev_dbg(ddev, "Performing OPC\n");
2096
2097         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2098         cgc.sshdr = &sshdr;
2099         cgc.timeout = 60*HZ;
2100         cgc.cmd[0] = GPCMD_SEND_OPC;
2101         cgc.cmd[1] = 1;
2102         ret = pkt_generic_packet(pd, &cgc);
2103         if (ret)
2104                 pkt_dump_sense(pd, &cgc);
2105         return ret;
2106 }
2107
2108 static int pkt_open_write(struct pktcdvd_device *pd)
2109 {
2110         struct device *ddev = disk_to_dev(pd->disk);
2111         int ret;
2112         unsigned int write_speed, media_write_speed, read_speed;
2113
2114         ret = pkt_probe_settings(pd);
2115         if (ret) {
2116                 dev_dbg(ddev, "failed probe\n");
2117                 return ret;
2118         }
2119
2120         ret = pkt_set_write_settings(pd);
2121         if (ret) {
2122                 dev_notice(ddev, "failed saving write settings\n");
2123                 return -EIO;
2124         }
2125
2126         pkt_write_caching(pd);
2127
2128         ret = pkt_get_max_speed(pd, &write_speed);
2129         if (ret)
2130                 write_speed = 16 * 177;
2131         switch (pd->mmc3_profile) {
2132                 case 0x13: /* DVD-RW */
2133                 case 0x1a: /* DVD+RW */
2134                 case 0x12: /* DVD-RAM */
2135                         dev_notice(ddev, "write speed %ukB/s\n", write_speed);
2136                         break;
2137                 default:
2138                         ret = pkt_media_speed(pd, &media_write_speed);
2139                         if (ret)
2140                                 media_write_speed = 16;
2141                         write_speed = min(write_speed, media_write_speed * 177);
2142                         dev_notice(ddev, "write speed %ux\n", write_speed / 176);
2143                         break;
2144         }
2145         read_speed = write_speed;
2146
2147         ret = pkt_set_speed(pd, write_speed, read_speed);
2148         if (ret) {
2149                 dev_notice(ddev, "couldn't set write speed\n");
2150                 return -EIO;
2151         }
2152         pd->write_speed = write_speed;
2153         pd->read_speed = read_speed;
2154
2155         ret = pkt_perform_opc(pd);
2156         if (ret)
2157                 dev_notice(ddev, "Optimum Power Calibration failed\n");
2158
2159         return 0;
2160 }
2161
2162 /*
2163  * called at open time.
2164  */
2165 static int pkt_open_dev(struct pktcdvd_device *pd, bool write)
2166 {
2167         struct device *ddev = disk_to_dev(pd->disk);
2168         int ret;
2169         long lba;
2170         struct request_queue *q;
2171         struct file *bdev_file;
2172
2173         /*
2174          * We need to re-open the cdrom device without O_NONBLOCK to be able
2175          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2176          * so open should not fail.
2177          */
2178         bdev_file = bdev_file_open_by_dev(file_bdev(pd->bdev_file)->bd_dev,
2179                                        BLK_OPEN_READ, pd, NULL);
2180         if (IS_ERR(bdev_file)) {
2181                 ret = PTR_ERR(bdev_file);
2182                 goto out;
2183         }
2184         pd->f_open_bdev = bdev_file;
2185
2186         ret = pkt_get_last_written(pd, &lba);
2187         if (ret) {
2188                 dev_err(ddev, "pkt_get_last_written failed\n");
2189                 goto out_putdev;
2190         }
2191
2192         set_capacity(pd->disk, lba << 2);
2193         set_capacity_and_notify(file_bdev(pd->bdev_file)->bd_disk, lba << 2);
2194
2195         q = bdev_get_queue(file_bdev(pd->bdev_file));
2196         if (write) {
2197                 ret = pkt_open_write(pd);
2198                 if (ret)
2199                         goto out_putdev;
2200                 set_bit(PACKET_WRITABLE, &pd->flags);
2201         } else {
2202                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2203                 clear_bit(PACKET_WRITABLE, &pd->flags);
2204         }
2205
2206         ret = pkt_set_segment_merging(pd, q);
2207         if (ret)
2208                 goto out_putdev;
2209
2210         if (write) {
2211                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2212                         dev_err(ddev, "not enough memory for buffers\n");
2213                         ret = -ENOMEM;
2214                         goto out_putdev;
2215                 }
2216                 dev_info(ddev, "%lukB available on disc\n", lba << 1);
2217         }
2218
2219         return 0;
2220
2221 out_putdev:
2222         fput(bdev_file);
2223 out:
2224         return ret;
2225 }
2226
2227 /*
2228  * called when the device is closed. makes sure that the device flushes
2229  * the internal cache before we close.
2230  */
2231 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2232 {
2233         struct device *ddev = disk_to_dev(pd->disk);
2234
2235         if (flush && pkt_flush_cache(pd))
2236                 dev_notice(ddev, "not flushing cache\n");
2237
2238         pkt_lock_door(pd, 0);
2239
2240         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2241         fput(pd->f_open_bdev);
2242         pd->f_open_bdev = NULL;
2243
2244         pkt_shrink_pktlist(pd);
2245 }
2246
2247 static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2248 {
2249         if (dev_minor >= MAX_WRITERS)
2250                 return NULL;
2251
2252         dev_minor = array_index_nospec(dev_minor, MAX_WRITERS);
2253         return pkt_devs[dev_minor];
2254 }
2255
2256 static int pkt_open(struct gendisk *disk, blk_mode_t mode)
2257 {
2258         struct pktcdvd_device *pd = NULL;
2259         int ret;
2260
2261         mutex_lock(&pktcdvd_mutex);
2262         mutex_lock(&ctl_mutex);
2263         pd = pkt_find_dev_from_minor(disk->first_minor);
2264         if (!pd) {
2265                 ret = -ENODEV;
2266                 goto out;
2267         }
2268         BUG_ON(pd->refcnt < 0);
2269
2270         pd->refcnt++;
2271         if (pd->refcnt > 1) {
2272                 if ((mode & BLK_OPEN_WRITE) &&
2273                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2274                         ret = -EBUSY;
2275                         goto out_dec;
2276                 }
2277         } else {
2278                 ret = pkt_open_dev(pd, mode & BLK_OPEN_WRITE);
2279                 if (ret)
2280                         goto out_dec;
2281                 /*
2282                  * needed here as well, since ext2 (among others) may change
2283                  * the blocksize at mount time
2284                  */
2285                 set_blocksize(disk->part0, CD_FRAMESIZE);
2286         }
2287         mutex_unlock(&ctl_mutex);
2288         mutex_unlock(&pktcdvd_mutex);
2289         return 0;
2290
2291 out_dec:
2292         pd->refcnt--;
2293 out:
2294         mutex_unlock(&ctl_mutex);
2295         mutex_unlock(&pktcdvd_mutex);
2296         return ret;
2297 }
2298
2299 static void pkt_release(struct gendisk *disk)
2300 {
2301         struct pktcdvd_device *pd = disk->private_data;
2302
2303         mutex_lock(&pktcdvd_mutex);
2304         mutex_lock(&ctl_mutex);
2305         pd->refcnt--;
2306         BUG_ON(pd->refcnt < 0);
2307         if (pd->refcnt == 0) {
2308                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2309                 pkt_release_dev(pd, flush);
2310         }
2311         mutex_unlock(&ctl_mutex);
2312         mutex_unlock(&pktcdvd_mutex);
2313 }
2314
2315
2316 static void pkt_end_io_read_cloned(struct bio *bio)
2317 {
2318         struct packet_stacked_data *psd = bio->bi_private;
2319         struct pktcdvd_device *pd = psd->pd;
2320
2321         psd->bio->bi_status = bio->bi_status;
2322         bio_put(bio);
2323         bio_endio(psd->bio);
2324         mempool_free(psd, &psd_pool);
2325         pkt_bio_finished(pd);
2326 }
2327
2328 static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
2329 {
2330         struct bio *cloned_bio = bio_alloc_clone(file_bdev(pd->bdev_file), bio,
2331                 GFP_NOIO, &pkt_bio_set);
2332         struct packet_stacked_data *psd = mempool_alloc(&psd_pool, GFP_NOIO);
2333
2334         psd->pd = pd;
2335         psd->bio = bio;
2336         cloned_bio->bi_private = psd;
2337         cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2338         pd->stats.secs_r += bio_sectors(bio);
2339         pkt_queue_bio(pd, cloned_bio);
2340 }
2341
2342 static void pkt_make_request_write(struct bio *bio)
2343 {
2344         struct pktcdvd_device *pd = bio->bi_bdev->bd_disk->private_data;
2345         sector_t zone;
2346         struct packet_data *pkt;
2347         int was_empty, blocked_bio;
2348         struct pkt_rb_node *node;
2349
2350         zone = get_zone(bio->bi_iter.bi_sector, pd);
2351
2352         /*
2353          * If we find a matching packet in state WAITING or READ_WAIT, we can
2354          * just append this bio to that packet.
2355          */
2356         spin_lock(&pd->cdrw.active_list_lock);
2357         blocked_bio = 0;
2358         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2359                 if (pkt->sector == zone) {
2360                         spin_lock(&pkt->lock);
2361                         if ((pkt->state == PACKET_WAITING_STATE) ||
2362                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2363                                 bio_list_add(&pkt->orig_bios, bio);
2364                                 pkt->write_size +=
2365                                         bio->bi_iter.bi_size / CD_FRAMESIZE;
2366                                 if ((pkt->write_size >= pkt->frames) &&
2367                                     (pkt->state == PACKET_WAITING_STATE)) {
2368                                         atomic_inc(&pkt->run_sm);
2369                                         wake_up(&pd->wqueue);
2370                                 }
2371                                 spin_unlock(&pkt->lock);
2372                                 spin_unlock(&pd->cdrw.active_list_lock);
2373                                 return;
2374                         } else {
2375                                 blocked_bio = 1;
2376                         }
2377                         spin_unlock(&pkt->lock);
2378                 }
2379         }
2380         spin_unlock(&pd->cdrw.active_list_lock);
2381
2382         /*
2383          * Test if there is enough room left in the bio work queue
2384          * (queue size >= congestion on mark).
2385          * If not, wait till the work queue size is below the congestion off mark.
2386          */
2387         spin_lock(&pd->lock);
2388         if (pd->write_congestion_on > 0
2389             && pd->bio_queue_size >= pd->write_congestion_on) {
2390                 struct wait_bit_queue_entry wqe;
2391
2392                 init_wait_var_entry(&wqe, &pd->congested, 0);
2393                 for (;;) {
2394                         prepare_to_wait_event(__var_waitqueue(&pd->congested),
2395                                               &wqe.wq_entry,
2396                                               TASK_UNINTERRUPTIBLE);
2397                         if (pd->bio_queue_size <= pd->write_congestion_off)
2398                                 break;
2399                         pd->congested = true;
2400                         spin_unlock(&pd->lock);
2401                         schedule();
2402                         spin_lock(&pd->lock);
2403                 }
2404         }
2405         spin_unlock(&pd->lock);
2406
2407         /*
2408          * No matching packet found. Store the bio in the work queue.
2409          */
2410         node = mempool_alloc(&pd->rb_pool, GFP_NOIO);
2411         node->bio = bio;
2412         spin_lock(&pd->lock);
2413         BUG_ON(pd->bio_queue_size < 0);
2414         was_empty = (pd->bio_queue_size == 0);
2415         pkt_rbtree_insert(pd, node);
2416         spin_unlock(&pd->lock);
2417
2418         /*
2419          * Wake up the worker thread.
2420          */
2421         atomic_set(&pd->scan_queue, 1);
2422         if (was_empty) {
2423                 /* This wake_up is required for correct operation */
2424                 wake_up(&pd->wqueue);
2425         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2426                 /*
2427                  * This wake up is not required for correct operation,
2428                  * but improves performance in some cases.
2429                  */
2430                 wake_up(&pd->wqueue);
2431         }
2432 }
2433
2434 static void pkt_submit_bio(struct bio *bio)
2435 {
2436         struct pktcdvd_device *pd = bio->bi_bdev->bd_disk->private_data;
2437         struct device *ddev = disk_to_dev(pd->disk);
2438         struct bio *split;
2439
2440         bio = bio_split_to_limits(bio);
2441         if (!bio)
2442                 return;
2443
2444         dev_dbg(ddev, "start = %6llx stop = %6llx\n",
2445                 bio->bi_iter.bi_sector, bio_end_sector(bio));
2446
2447         /*
2448          * Clone READ bios so we can have our own bi_end_io callback.
2449          */
2450         if (bio_data_dir(bio) == READ) {
2451                 pkt_make_request_read(pd, bio);
2452                 return;
2453         }
2454
2455         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2456                 dev_notice(ddev, "WRITE for ro device (%llu)\n", bio->bi_iter.bi_sector);
2457                 goto end_io;
2458         }
2459
2460         if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2461                 dev_err(ddev, "wrong bio size\n");
2462                 goto end_io;
2463         }
2464
2465         do {
2466                 sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
2467                 sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2468
2469                 if (last_zone != zone) {
2470                         BUG_ON(last_zone != zone + pd->settings.size);
2471
2472                         split = bio_split(bio, last_zone -
2473                                           bio->bi_iter.bi_sector,
2474                                           GFP_NOIO, &pkt_bio_set);
2475                         bio_chain(split, bio);
2476                 } else {
2477                         split = bio;
2478                 }
2479
2480                 pkt_make_request_write(split);
2481         } while (split != bio);
2482
2483         return;
2484 end_io:
2485         bio_io_error(bio);
2486 }
2487
2488 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2489 {
2490         struct device *ddev = disk_to_dev(pd->disk);
2491         int i;
2492         struct file *bdev_file;
2493         struct scsi_device *sdev;
2494
2495         if (pd->pkt_dev == dev) {
2496                 dev_err(ddev, "recursive setup not allowed\n");
2497                 return -EBUSY;
2498         }
2499         for (i = 0; i < MAX_WRITERS; i++) {
2500                 struct pktcdvd_device *pd2 = pkt_devs[i];
2501                 if (!pd2)
2502                         continue;
2503                 if (file_bdev(pd2->bdev_file)->bd_dev == dev) {
2504                         dev_err(ddev, "%pg already setup\n",
2505                                 file_bdev(pd2->bdev_file));
2506                         return -EBUSY;
2507                 }
2508                 if (pd2->pkt_dev == dev) {
2509                         dev_err(ddev, "can't chain pktcdvd devices\n");
2510                         return -EBUSY;
2511                 }
2512         }
2513
2514         bdev_file = bdev_file_open_by_dev(dev, BLK_OPEN_READ | BLK_OPEN_NDELAY,
2515                                        NULL, NULL);
2516         if (IS_ERR(bdev_file))
2517                 return PTR_ERR(bdev_file);
2518         sdev = scsi_device_from_queue(file_bdev(bdev_file)->bd_disk->queue);
2519         if (!sdev) {
2520                 fput(bdev_file);
2521                 return -EINVAL;
2522         }
2523         put_device(&sdev->sdev_gendev);
2524
2525         /* This is safe, since we have a reference from open(). */
2526         __module_get(THIS_MODULE);
2527
2528         pd->bdev_file = bdev_file;
2529         set_blocksize(file_bdev(bdev_file), CD_FRAMESIZE);
2530
2531         atomic_set(&pd->cdrw.pending_bios, 0);
2532         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->disk->disk_name);
2533         if (IS_ERR(pd->cdrw.thread)) {
2534                 dev_err(ddev, "can't start kernel thread\n");
2535                 goto out_mem;
2536         }
2537
2538         proc_create_single_data(pd->disk->disk_name, 0, pkt_proc, pkt_seq_show, pd);
2539         dev_notice(ddev, "writer mapped to %pg\n", file_bdev(bdev_file));
2540         return 0;
2541
2542 out_mem:
2543         fput(bdev_file);
2544         /* This is safe: open() is still holding a reference. */
2545         module_put(THIS_MODULE);
2546         return -ENOMEM;
2547 }
2548
2549 static int pkt_ioctl(struct block_device *bdev, blk_mode_t mode,
2550                 unsigned int cmd, unsigned long arg)
2551 {
2552         struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2553         struct device *ddev = disk_to_dev(pd->disk);
2554         int ret;
2555
2556         dev_dbg(ddev, "cmd %x, dev %d:%d\n", cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2557
2558         mutex_lock(&pktcdvd_mutex);
2559         switch (cmd) {
2560         case CDROMEJECT:
2561                 /*
2562                  * The door gets locked when the device is opened, so we
2563                  * have to unlock it or else the eject command fails.
2564                  */
2565                 if (pd->refcnt == 1)
2566                         pkt_lock_door(pd, 0);
2567                 fallthrough;
2568         /*
2569          * forward selected CDROM ioctls to CD-ROM, for UDF
2570          */
2571         case CDROMMULTISESSION:
2572         case CDROMREADTOCENTRY:
2573         case CDROM_LAST_WRITTEN:
2574         case CDROM_SEND_PACKET:
2575         case SCSI_IOCTL_SEND_COMMAND:
2576                 if (!bdev->bd_disk->fops->ioctl)
2577                         ret = -ENOTTY;
2578                 else
2579                         ret = bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
2580                 break;
2581         default:
2582                 dev_dbg(ddev, "Unknown ioctl (%x)\n", cmd);
2583                 ret = -ENOTTY;
2584         }
2585         mutex_unlock(&pktcdvd_mutex);
2586
2587         return ret;
2588 }
2589
2590 static unsigned int pkt_check_events(struct gendisk *disk,
2591                                      unsigned int clearing)
2592 {
2593         struct pktcdvd_device *pd = disk->private_data;
2594         struct gendisk *attached_disk;
2595
2596         if (!pd)
2597                 return 0;
2598         if (!pd->bdev_file)
2599                 return 0;
2600         attached_disk = file_bdev(pd->bdev_file)->bd_disk;
2601         if (!attached_disk || !attached_disk->fops->check_events)
2602                 return 0;
2603         return attached_disk->fops->check_events(attached_disk, clearing);
2604 }
2605
2606 static char *pkt_devnode(struct gendisk *disk, umode_t *mode)
2607 {
2608         return kasprintf(GFP_KERNEL, "pktcdvd/%s", disk->disk_name);
2609 }
2610
2611 static const struct block_device_operations pktcdvd_ops = {
2612         .owner =                THIS_MODULE,
2613         .submit_bio =           pkt_submit_bio,
2614         .open =                 pkt_open,
2615         .release =              pkt_release,
2616         .ioctl =                pkt_ioctl,
2617         .compat_ioctl =         blkdev_compat_ptr_ioctl,
2618         .check_events =         pkt_check_events,
2619         .devnode =              pkt_devnode,
2620 };
2621
2622 /*
2623  * Set up mapping from pktcdvd device to CD-ROM device.
2624  */
2625 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2626 {
2627         struct queue_limits lim = {
2628                 .max_hw_sectors         = PACKET_MAX_SECTORS,
2629                 .logical_block_size     = CD_FRAMESIZE,
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         disk = blk_alloc_disk(&lim, NUMA_NO_NODE);
2671         if (IS_ERR(disk)) {
2672                 ret = PTR_ERR(disk);
2673                 goto out_mem;
2674         }
2675         pd->disk = disk;
2676         disk->major = pktdev_major;
2677         disk->first_minor = idx;
2678         disk->minors = 1;
2679         disk->fops = &pktcdvd_ops;
2680         disk->flags = GENHD_FL_REMOVABLE | GENHD_FL_NO_PART;
2681         snprintf(disk->disk_name, sizeof(disk->disk_name), DRIVER_NAME"%d", idx);
2682         disk->private_data = pd;
2683
2684         pd->pkt_dev = MKDEV(pktdev_major, idx);
2685         ret = pkt_new_dev(pd, dev);
2686         if (ret)
2687                 goto out_mem2;
2688
2689         /* inherit events of the host device */
2690         disk->events = file_bdev(pd->bdev_file)->bd_disk->events;
2691
2692         ret = add_disk(disk);
2693         if (ret)
2694                 goto out_mem2;
2695
2696         pkt_sysfs_dev_new(pd);
2697         pkt_debugfs_dev_new(pd);
2698
2699         pkt_devs[idx] = pd;
2700         if (pkt_dev)
2701                 *pkt_dev = pd->pkt_dev;
2702
2703         mutex_unlock(&ctl_mutex);
2704         return 0;
2705
2706 out_mem2:
2707         put_disk(disk);
2708 out_mem:
2709         mempool_exit(&pd->rb_pool);
2710         kfree(pd);
2711 out_mutex:
2712         mutex_unlock(&ctl_mutex);
2713         pr_err("setup of pktcdvd device failed\n");
2714         return ret;
2715 }
2716
2717 /*
2718  * Tear down mapping from pktcdvd device to CD-ROM device.
2719  */
2720 static int pkt_remove_dev(dev_t pkt_dev)
2721 {
2722         struct pktcdvd_device *pd;
2723         struct device *ddev;
2724         int idx;
2725         int ret = 0;
2726
2727         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2728
2729         for (idx = 0; idx < MAX_WRITERS; idx++) {
2730                 pd = pkt_devs[idx];
2731                 if (pd && (pd->pkt_dev == pkt_dev))
2732                         break;
2733         }
2734         if (idx == MAX_WRITERS) {
2735                 pr_debug("dev not setup\n");
2736                 ret = -ENXIO;
2737                 goto out;
2738         }
2739
2740         if (pd->refcnt > 0) {
2741                 ret = -EBUSY;
2742                 goto out;
2743         }
2744
2745         ddev = disk_to_dev(pd->disk);
2746
2747         if (!IS_ERR(pd->cdrw.thread))
2748                 kthread_stop(pd->cdrw.thread);
2749
2750         pkt_devs[idx] = NULL;
2751
2752         pkt_debugfs_dev_remove(pd);
2753         pkt_sysfs_dev_remove(pd);
2754
2755         fput(pd->bdev_file);
2756
2757         remove_proc_entry(pd->disk->disk_name, pkt_proc);
2758         dev_notice(ddev, "writer unmapped\n");
2759
2760         del_gendisk(pd->disk);
2761         put_disk(pd->disk);
2762
2763         mempool_exit(&pd->rb_pool);
2764         kfree(pd);
2765
2766         /* This is safe: open() is still holding a reference. */
2767         module_put(THIS_MODULE);
2768
2769 out:
2770         mutex_unlock(&ctl_mutex);
2771         return ret;
2772 }
2773
2774 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2775 {
2776         struct pktcdvd_device *pd;
2777
2778         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2779
2780         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2781         if (pd) {
2782                 ctrl_cmd->dev = new_encode_dev(file_bdev(pd->bdev_file)->bd_dev);
2783                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2784         } else {
2785                 ctrl_cmd->dev = 0;
2786                 ctrl_cmd->pkt_dev = 0;
2787         }
2788         ctrl_cmd->num_devices = MAX_WRITERS;
2789
2790         mutex_unlock(&ctl_mutex);
2791 }
2792
2793 static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2794 {
2795         void __user *argp = (void __user *)arg;
2796         struct pkt_ctrl_command ctrl_cmd;
2797         int ret = 0;
2798         dev_t pkt_dev = 0;
2799
2800         if (cmd != PACKET_CTRL_CMD)
2801                 return -ENOTTY;
2802
2803         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2804                 return -EFAULT;
2805
2806         switch (ctrl_cmd.command) {
2807         case PKT_CTRL_CMD_SETUP:
2808                 if (!capable(CAP_SYS_ADMIN))
2809                         return -EPERM;
2810                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2811                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2812                 break;
2813         case PKT_CTRL_CMD_TEARDOWN:
2814                 if (!capable(CAP_SYS_ADMIN))
2815                         return -EPERM;
2816                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2817                 break;
2818         case PKT_CTRL_CMD_STATUS:
2819                 pkt_get_status(&ctrl_cmd);
2820                 break;
2821         default:
2822                 return -ENOTTY;
2823         }
2824
2825         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2826                 return -EFAULT;
2827         return ret;
2828 }
2829
2830 #ifdef CONFIG_COMPAT
2831 static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2832 {
2833         return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2834 }
2835 #endif
2836
2837 static const struct file_operations pkt_ctl_fops = {
2838         .open           = nonseekable_open,
2839         .unlocked_ioctl = pkt_ctl_ioctl,
2840 #ifdef CONFIG_COMPAT
2841         .compat_ioctl   = pkt_ctl_compat_ioctl,
2842 #endif
2843         .owner          = THIS_MODULE,
2844         .llseek         = no_llseek,
2845 };
2846
2847 static struct miscdevice pkt_misc = {
2848         .minor          = MISC_DYNAMIC_MINOR,
2849         .name           = DRIVER_NAME,
2850         .nodename       = "pktcdvd/control",
2851         .fops           = &pkt_ctl_fops
2852 };
2853
2854 static int __init pkt_init(void)
2855 {
2856         int ret;
2857
2858         mutex_init(&ctl_mutex);
2859
2860         ret = mempool_init_kmalloc_pool(&psd_pool, PSD_POOL_SIZE,
2861                                     sizeof(struct packet_stacked_data));
2862         if (ret)
2863                 return ret;
2864         ret = bioset_init(&pkt_bio_set, BIO_POOL_SIZE, 0, 0);
2865         if (ret) {
2866                 mempool_exit(&psd_pool);
2867                 return ret;
2868         }
2869
2870         ret = register_blkdev(pktdev_major, DRIVER_NAME);
2871         if (ret < 0) {
2872                 pr_err("unable to register block device\n");
2873                 goto out2;
2874         }
2875         if (!pktdev_major)
2876                 pktdev_major = ret;
2877
2878         ret = pkt_sysfs_init();
2879         if (ret)
2880                 goto out;
2881
2882         pkt_debugfs_init();
2883
2884         ret = misc_register(&pkt_misc);
2885         if (ret) {
2886                 pr_err("unable to register misc device\n");
2887                 goto out_misc;
2888         }
2889
2890         pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
2891
2892         return 0;
2893
2894 out_misc:
2895         pkt_debugfs_cleanup();
2896         pkt_sysfs_cleanup();
2897 out:
2898         unregister_blkdev(pktdev_major, DRIVER_NAME);
2899 out2:
2900         mempool_exit(&psd_pool);
2901         bioset_exit(&pkt_bio_set);
2902         return ret;
2903 }
2904
2905 static void __exit pkt_exit(void)
2906 {
2907         remove_proc_entry("driver/"DRIVER_NAME, NULL);
2908         misc_deregister(&pkt_misc);
2909
2910         pkt_debugfs_cleanup();
2911         pkt_sysfs_cleanup();
2912
2913         unregister_blkdev(pktdev_major, DRIVER_NAME);
2914         mempool_exit(&psd_pool);
2915         bioset_exit(&pkt_bio_set);
2916 }
2917
2918 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
2919 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
2920 MODULE_LICENSE("GPL");
2921
2922 module_init(pkt_init);
2923 module_exit(pkt_exit);