drivers/block/pktcdvd.c

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