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  * typically ide-cd.c or 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  * create and register a pktcdvd kernel object.
 118  */
 119 static struct pktcdvd_kobj* pkt_kobj_create(struct pktcdvd_device *pd,
 120                                         const char* name,
 121                                         struct kobject* parent,
 122                                         struct kobj_type* ktype)
 123 {
 124         struct pktcdvd_kobj *p;
 125         int error;
 126
 127         p = kzalloc(sizeof(*p), GFP_KERNEL);
 128         if (!p)
 129                 return NULL;
 130         p->pd = pd;
 131         error = kobject_init_and_add(&p->kobj, ktype, parent, "%s", name);
 132         if (error) {
 133                 kobject_put(&p->kobj);
 134                 return NULL;
 135         }
 136         kobject_uevent(&p->kobj, KOBJ_ADD);
 137         return p;
 138 }
 139 /*
 140  * remove a pktcdvd kernel object.
 141  */
 142 static void pkt_kobj_remove(struct pktcdvd_kobj *p)
 143 {
 144         if (p)
 145                 kobject_put(&p->kobj);
 146 }
 147 /*
 148  * default release function for pktcdvd kernel objects.
 149  */
 150 static void pkt_kobj_release(struct kobject *kobj)
 151 {
 152         kfree(to_pktcdvdkobj(kobj));
 153 }
 154
 155
 156 /**********************************************************
 157  *
 158  * sysfs interface for pktcdvd
 159  * by (C) 2006  Thomas Maier <balagi@justmail.de>
 160  *
 161  **********************************************************/
 162
 163 #define DEF_ATTR(_obj,_name,_mode) \
 164         static struct attribute _obj = { .name = _name, .mode = _mode }
 165
 166 /**********************************************************
 167   /sys/class/pktcdvd/pktcdvd[0-7]/
 168                      stat/reset
 169                      stat/packets_started
 170                      stat/packets_finished
 171                      stat/kb_written
 172                      stat/kb_read
 173                      stat/kb_read_gather
 174                      write_queue/size
 175                      write_queue/congestion_off
 176                      write_queue/congestion_on
 177  **********************************************************/
 178
 179 DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
 180 DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
 181 DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
 182 DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
 183 DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
 184 DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
 185
 186 static struct attribute *kobj_pkt_attrs_stat[] = {
 187         &kobj_pkt_attr_st1,
 188         &kobj_pkt_attr_st2,
 189         &kobj_pkt_attr_st3,
 190         &kobj_pkt_attr_st4,
 191         &kobj_pkt_attr_st5,
 192         &kobj_pkt_attr_st6,
 193         NULL
 194 };
 195
 196 DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
 197 DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
 198 DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on",  0644);
 199
 200 static struct attribute *kobj_pkt_attrs_wqueue[] = {
 201         &kobj_pkt_attr_wq1,
 202         &kobj_pkt_attr_wq2,
 203         &kobj_pkt_attr_wq3,
 204         NULL
 205 };
 206
 207 static ssize_t kobj_pkt_show(struct kobject *kobj,
 208                         struct attribute *attr, char *data)
 209 {
 210         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 211         int n = 0;
 212         int v;
 213         if (strcmp(attr->name, "packets_started") == 0) {
 214                 n = sprintf(data, "%lu\n", pd->stats.pkt_started);
 215
 216         } else if (strcmp(attr->name, "packets_finished") == 0) {
 217                 n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
 218
 219         } else if (strcmp(attr->name, "kb_written") == 0) {
 220                 n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
 221
 222         } else if (strcmp(attr->name, "kb_read") == 0) {
 223                 n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
 224
 225         } else if (strcmp(attr->name, "kb_read_gather") == 0) {
 226                 n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
 227
 228         } else if (strcmp(attr->name, "size") == 0) {
 229                 spin_lock(&pd->lock);
 230                 v = pd->bio_queue_size;
 231                 spin_unlock(&pd->lock);
 232                 n = sprintf(data, "%d\n", v);
 233
 234         } else if (strcmp(attr->name, "congestion_off") == 0) {
 235                 spin_lock(&pd->lock);
 236                 v = pd->write_congestion_off;
 237                 spin_unlock(&pd->lock);
 238                 n = sprintf(data, "%d\n", v);
 239
 240         } else if (strcmp(attr->name, "congestion_on") == 0) {
 241                 spin_lock(&pd->lock);
 242                 v = pd->write_congestion_on;
 243                 spin_unlock(&pd->lock);
 244                 n = sprintf(data, "%d\n", v);
 245         }
 246         return n;
 247 }
 248
 249 static void init_write_congestion_marks(int* lo, int* hi)
 250 {
 251         if (*hi > 0) {
 252                 *hi = max(*hi, 500);
 253                 *hi = min(*hi, 1000000);
 254                 if (*lo <= 0)
 255                         *lo = *hi - 100;
 256                 else {
 257                         *lo = min(*lo, *hi - 100);
 258                         *lo = max(*lo, 100);
 259                 }
 260         } else {
 261                 *hi = -1;
 262                 *lo = -1;
 263         }
 264 }
 265
 266 static ssize_t kobj_pkt_store(struct kobject *kobj,
 267                         struct attribute *attr,
 268                         const char *data, size_t len)
 269 {
 270         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 271         int val;
 272
 273         if (strcmp(attr->name, "reset") == 0 && len > 0) {
 274                 pd->stats.pkt_started = 0;
 275                 pd->stats.pkt_ended = 0;
 276                 pd->stats.secs_w = 0;
 277                 pd->stats.secs_rg = 0;
 278                 pd->stats.secs_r = 0;
 279
 280         } else if (strcmp(attr->name, "congestion_off") == 0
 281                    && sscanf(data, "%d", &val) == 1) {
 282                 spin_lock(&pd->lock);
 283                 pd->write_congestion_off = val;
 284                 init_write_congestion_marks(&pd->write_congestion_off,
 285                                         &pd->write_congestion_on);
 286                 spin_unlock(&pd->lock);
 287
 288         } else if (strcmp(attr->name, "congestion_on") == 0
 289                    && sscanf(data, "%d", &val) == 1) {
 290                 spin_lock(&pd->lock);
 291                 pd->write_congestion_on = val;
 292                 init_write_congestion_marks(&pd->write_congestion_off,
 293                                         &pd->write_congestion_on);
 294                 spin_unlock(&pd->lock);
 295         }
 296         return len;
 297 }
 298
 299 static const struct sysfs_ops kobj_pkt_ops = {
 300         .show = kobj_pkt_show,
 301         .store = kobj_pkt_store
 302 };
 303 static struct kobj_type kobj_pkt_type_stat = {
 304         .release = pkt_kobj_release,
 305         .sysfs_ops = &kobj_pkt_ops,
 306         .default_attrs = kobj_pkt_attrs_stat
 307 };
 308 static struct kobj_type kobj_pkt_type_wqueue = {
 309         .release = pkt_kobj_release,
 310         .sysfs_ops = &kobj_pkt_ops,
 311         .default_attrs = kobj_pkt_attrs_wqueue
 312 };
 313
 314 static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
 315 {
 316         if (class_pktcdvd) {
 317                 pd->dev = device_create(class_pktcdvd, NULL, MKDEV(0, 0), NULL,
 318                                         "%s", pd->name);
 319                 if (IS_ERR(pd->dev))
 320                         pd->dev = NULL;
 321         }
 322         if (pd->dev) {
 323                 pd->kobj_stat = pkt_kobj_create(pd, "stat",
 324                                         &pd->dev->kobj,
 325                                         &kobj_pkt_type_stat);
 326                 pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
 327                                         &pd->dev->kobj,
 328                                         &kobj_pkt_type_wqueue);
 329         }
 330 }
 331
 332 static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
 333 {
 334         pkt_kobj_remove(pd->kobj_stat);
 335         pkt_kobj_remove(pd->kobj_wqueue);
 336         if (class_pktcdvd)
 337                 device_unregister(pd->dev);
 338 }
 339
 340
 341 /********************************************************************
 342   /sys/class/pktcdvd/
 343                      add            map block device
 344                      remove         unmap packet dev
 345                      device_map     show mappings
 346  *******************************************************************/
 347
 348 static void class_pktcdvd_release(struct class *cls)
 349 {
 350         kfree(cls);
 351 }
 352
 353 static ssize_t device_map_show(struct class *c, struct class_attribute *attr,
 354                                char *data)
 355 {
 356         int n = 0;
 357         int idx;
 358         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
 359         for (idx = 0; idx < MAX_WRITERS; idx++) {
 360                 struct pktcdvd_device *pd = pkt_devs[idx];
 361                 if (!pd)
 362                         continue;
 363                 n += sprintf(data+n, "%s %u:%u %u:%u\n",
 364                         pd->name,
 365                         MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
 366                         MAJOR(pd->bdev->bd_dev),
 367                         MINOR(pd->bdev->bd_dev));
 368         }
 369         mutex_unlock(&ctl_mutex);
 370         return n;
 371 }
 372 static CLASS_ATTR_RO(device_map);
 373
 374 static ssize_t add_store(struct class *c, struct class_attribute *attr,
 375                          const char *buf, size_t count)
 376 {
 377         unsigned int major, minor;
 378
 379         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 380                 /* pkt_setup_dev() expects caller to hold reference to self */
 381                 if (!try_module_get(THIS_MODULE))
 382                         return -ENODEV;
 383
 384                 pkt_setup_dev(MKDEV(major, minor), NULL);
 385
 386                 module_put(THIS_MODULE);
 387
 388                 return count;
 389         }
 390
 391         return -EINVAL;
 392 }
 393 static CLASS_ATTR_WO(add);
 394
 395 static ssize_t remove_store(struct class *c, struct class_attribute *attr,
 396                             const char *buf, size_t count)
 397 {
 398         unsigned int major, minor;
 399         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 400                 pkt_remove_dev(MKDEV(major, minor));
 401                 return count;
 402         }
 403         return -EINVAL;
 404 }
 405 static CLASS_ATTR_WO(remove);
 406
 407 static struct attribute *class_pktcdvd_attrs[] = {
 408         &class_attr_add.attr,
 409         &class_attr_remove.attr,
 410         &class_attr_device_map.attr,
 411         NULL,
 412 };
 413 ATTRIBUTE_GROUPS(class_pktcdvd);
 414
 415 static int pkt_sysfs_init(void)
 416 {
 417         int ret = 0;
 418
 419         /*
 420          * create control files in sysfs
 421          * /sys/class/pktcdvd/...
 422          */
 423         class_pktcdvd = kzalloc(sizeof(*class_pktcdvd), GFP_KERNEL);
 424         if (!class_pktcdvd)
 425                 return -ENOMEM;
 426         class_pktcdvd->name = DRIVER_NAME;
 427         class_pktcdvd->owner = THIS_MODULE;
 428         class_pktcdvd->class_release = class_pktcdvd_release;
 429         class_pktcdvd->class_groups = class_pktcdvd_groups;
 430         ret = class_register(class_pktcdvd);
 431         if (ret) {
 432                 kfree(class_pktcdvd);
 433                 class_pktcdvd = NULL;
 434                 pr_err("failed to create class pktcdvd\n");
 435                 return ret;
 436         }
 437         return 0;
 438 }
 439
 440 static void pkt_sysfs_cleanup(void)
 441 {
 442         if (class_pktcdvd)
 443                 class_destroy(class_pktcdvd);
 444         class_pktcdvd = NULL;
 445 }
 446
 447 /********************************************************************
 448   entries in debugfs
 449
 450   /sys/kernel/debug/pktcdvd[0-7]/
 451                         info
 452
 453  *******************************************************************/
 454
 455 static int pkt_debugfs_seq_show(struct seq_file *m, void *p)
 456 {
 457         return pkt_seq_show(m, p);
 458 }
 459
 460 static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
 461 {
 462         return single_open(file, pkt_debugfs_seq_show, inode->i_private);
 463 }
 464
 465 static const struct file_operations debug_fops = {
 466         .open           = pkt_debugfs_fops_open,
 467         .read           = seq_read,
 468         .llseek         = seq_lseek,
 469         .release        = single_release,
 470         .owner          = THIS_MODULE,
 471 };
 472
 473 static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
 474 {
 475         if (!pkt_debugfs_root)
 476                 return;
 477         pd->dfs_d_root = debugfs_create_dir(pd->name, pkt_debugfs_root);
 478         if (!pd->dfs_d_root)
 479                 return;
 480
 481         pd->dfs_f_info = debugfs_create_file("info", 0444,
 482                                              pd->dfs_d_root, pd, &debug_fops);
 483 }
 484
 485 static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
 486 {
 487         if (!pkt_debugfs_root)
 488                 return;
 489         debugfs_remove(pd->dfs_f_info);
 490         debugfs_remove(pd->dfs_d_root);
 491         pd->dfs_f_info = NULL;
 492         pd->dfs_d_root = NULL;
 493 }
 494
 495 static void pkt_debugfs_init(void)
 496 {
 497         pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
 498 }
 499
 500 static void pkt_debugfs_cleanup(void)
 501 {
 502         debugfs_remove(pkt_debugfs_root);
 503         pkt_debugfs_root = NULL;
 504 }
 505
 506 /* ----------------------------------------------------------*/
 507
 508
 509 static void pkt_bio_finished(struct pktcdvd_device *pd)
 510 {
 511         BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
 512         if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
 513                 pkt_dbg(2, pd, "queue empty\n");
 514                 atomic_set(&pd->iosched.attention, 1);
 515                 wake_up(&pd->wqueue);
 516         }
 517 }
 518
 519 /*
 520  * Allocate a packet_data struct
 521  */
 522 static struct packet_data *pkt_alloc_packet_data(int frames)
 523 {
 524         int i;
 525         struct packet_data *pkt;
 526
 527         pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
 528         if (!pkt)
 529                 goto no_pkt;
 530
 531         pkt->frames = frames;
 532         pkt->w_bio = bio_kmalloc(GFP_KERNEL, frames);
 533         if (!pkt->w_bio)
 534                 goto no_bio;
 535
 536         for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
 537                 pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
 538                 if (!pkt->pages[i])
 539                         goto no_page;
 540         }
 541
 542         spin_lock_init(&pkt->lock);
 543         bio_list_init(&pkt->orig_bios);
 544
 545         for (i = 0; i < frames; i++) {
 546                 struct bio *bio = bio_kmalloc(GFP_KERNEL, 1);
 547                 if (!bio)
 548                         goto no_rd_bio;
 549
 550                 pkt->r_bios[i] = bio;
 551         }
 552
 553         return pkt;
 554
 555 no_rd_bio:
 556         for (i = 0; i < frames; i++) {
 557                 struct bio *bio = pkt->r_bios[i];
 558                 if (bio)
 559                         bio_put(bio);
 560         }
 561
 562 no_page:
 563         for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
 564                 if (pkt->pages[i])
 565                         __free_page(pkt->pages[i]);
 566         bio_put(pkt->w_bio);
 567 no_bio:
 568         kfree(pkt);
 569 no_pkt:
 570         return NULL;
 571 }
 572
 573 /*
 574  * Free a packet_data struct
 575  */
 576 static void pkt_free_packet_data(struct packet_data *pkt)
 577 {
 578         int i;
 579
 580         for (i = 0; i < pkt->frames; i++) {
 581                 struct bio *bio = pkt->r_bios[i];
 582                 if (bio)
 583                         bio_put(bio);
 584         }
 585         for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
 586                 __free_page(pkt->pages[i]);
 587         bio_put(pkt->w_bio);
 588         kfree(pkt);
 589 }
 590
 591 static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
 592 {
 593         struct packet_data *pkt, *next;
 594
 595         BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
 596
 597         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
 598                 pkt_free_packet_data(pkt);
 599         }
 600         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
 601 }
 602
 603 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
 604 {
 605         struct packet_data *pkt;
 606
 607         BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
 608
 609         while (nr_packets > 0) {
 610                 pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
 611                 if (!pkt) {
 612                         pkt_shrink_pktlist(pd);
 613                         return 0;
 614                 }
 615                 pkt->id = nr_packets;
 616                 pkt->pd = pd;
 617                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
 618                 nr_packets--;
 619         }
 620         return 1;
 621 }
 622
 623 static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
 624 {
 625         struct rb_node *n = rb_next(&node->rb_node);
 626         if (!n)
 627                 return NULL;
 628         return rb_entry(n, struct pkt_rb_node, rb_node);
 629 }
 630
 631 static void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 632 {
 633         rb_erase(&node->rb_node, &pd->bio_queue);
 634         mempool_free(node, &pd->rb_pool);
 635         pd->bio_queue_size--;
 636         BUG_ON(pd->bio_queue_size < 0);
 637 }
 638
 639 /*
 640  * Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
 641  */
 642 static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
 643 {
 644         struct rb_node *n = pd->bio_queue.rb_node;
 645         struct rb_node *next;
 646         struct pkt_rb_node *tmp;
 647
 648         if (!n) {
 649                 BUG_ON(pd->bio_queue_size > 0);
 650                 return NULL;
 651         }
 652
 653         for (;;) {
 654                 tmp = rb_entry(n, struct pkt_rb_node, rb_node);
 655                 if (s <= tmp->bio->bi_iter.bi_sector)
 656                         next = n->rb_left;
 657                 else
 658                         next = n->rb_right;
 659                 if (!next)
 660                         break;
 661                 n = next;
 662         }
 663
 664         if (s > tmp->bio->bi_iter.bi_sector) {
 665                 tmp = pkt_rbtree_next(tmp);
 666                 if (!tmp)
 667                         return NULL;
 668         }
 669         BUG_ON(s > tmp->bio->bi_iter.bi_sector);
 670         return tmp;
 671 }
 672
 673 /*
 674  * Insert a node into the pd->bio_queue rb tree.
 675  */
 676 static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 677 {
 678         struct rb_node **p = &pd->bio_queue.rb_node;
 679         struct rb_node *parent = NULL;
 680         sector_t s = node->bio->bi_iter.bi_sector;
 681         struct pkt_rb_node *tmp;
 682
 683         while (*p) {
 684                 parent = *p;
 685                 tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
 686                 if (s < tmp->bio->bi_iter.bi_sector)
 687                         p = &(*p)->rb_left;
 688                 else
 689                         p = &(*p)->rb_right;
 690         }
 691         rb_link_node(&node->rb_node, parent, p);
 692         rb_insert_color(&node->rb_node, &pd->bio_queue);
 693         pd->bio_queue_size++;
 694 }
 695
 696 /*
 697  * Send a packet_command to the underlying block device and
 698  * wait for completion.
 699  */
 700 static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
 701 {
 702         struct request_queue *q = bdev_get_queue(pd->bdev);
 703         struct request *rq;
 704         int ret = 0;
 705
 706         rq = scsi_alloc_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
 707                              REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 708         if (IS_ERR(rq))
 709                 return PTR_ERR(rq);
 710
 711         if (cgc->buflen) {
 712                 ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
 713                                       GFP_NOIO);
 714                 if (ret)
 715                         goto out;
 716         }
 717
 718         scsi_req(rq)->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
 719         memcpy(scsi_req(rq)->cmd, cgc->cmd, CDROM_PACKET_SIZE);
 720
 721         rq->timeout = 60*HZ;
 722         if (cgc->quiet)
 723                 rq->rq_flags |= RQF_QUIET;
 724
 725         blk_execute_rq(rq, false);
 726         if (scsi_req(rq)->result)
 727                 ret = -EIO;
 728 out:
 729         blk_mq_free_request(rq);
 730         return ret;
 731 }
 732
 733 static const char *sense_key_string(__u8 index)
 734 {
 735         static const char * const info[] = {
 736                 "No sense", "Recovered error", "Not ready",
 737                 "Medium error", "Hardware error", "Illegal request",
 738                 "Unit attention", "Data protect", "Blank check",
 739         };
 740
 741         return index < ARRAY_SIZE(info) ? info[index] : "INVALID";
 742 }
 743
 744 /*
 745  * A generic sense dump / resolve mechanism should be implemented across
 746  * all ATAPI + SCSI devices.
 747  */
 748 static void pkt_dump_sense(struct pktcdvd_device *pd,
 749                            struct packet_command *cgc)
 750 {
 751         struct scsi_sense_hdr *sshdr = cgc->sshdr;
 752
 753         if (sshdr)
 754                 pkt_err(pd, "%*ph - sense %02x.%02x.%02x (%s)\n",
 755                         CDROM_PACKET_SIZE, cgc->cmd,
 756                         sshdr->sense_key, sshdr->asc, sshdr->ascq,
 757                         sense_key_string(sshdr->sense_key));
 758         else
 759                 pkt_err(pd, "%*ph - no sense\n", CDROM_PACKET_SIZE, cgc->cmd);
 760 }
 761
 762 /*
 763  * flush the drive cache to media
 764  */
 765 static int pkt_flush_cache(struct pktcdvd_device *pd)
 766 {
 767         struct packet_command cgc;
 768
 769         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 770         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 771         cgc.quiet = 1;
 772
 773         /*
 774          * the IMMED bit -- we default to not setting it, although that
 775          * would allow a much faster close, this is safer
 776          */
 777 #if 0
 778         cgc.cmd[1] = 1 << 1;
 779 #endif
 780         return pkt_generic_packet(pd, &cgc);
 781 }
 782
 783 /*
 784  * speed is given as the normal factor, e.g. 4 for 4x
 785  */
 786 static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
 787                                 unsigned write_speed, unsigned read_speed)
 788 {
 789         struct packet_command cgc;
 790         struct scsi_sense_hdr sshdr;
 791         int ret;
 792
 793         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 794         cgc.sshdr = &sshdr;
 795         cgc.cmd[0] = GPCMD_SET_SPEED;
 796         cgc.cmd[2] = (read_speed >> 8) & 0xff;
 797         cgc.cmd[3] = read_speed & 0xff;
 798         cgc.cmd[4] = (write_speed >> 8) & 0xff;
 799         cgc.cmd[5] = write_speed & 0xff;
 800
 801         ret = pkt_generic_packet(pd, &cgc);
 802         if (ret)
 803                 pkt_dump_sense(pd, &cgc);
 804
 805         return ret;
 806 }
 807
 808 /*
 809  * Queue a bio for processing by the low-level CD device. Must be called
 810  * from process context.
 811  */
 812 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 813 {
 814         spin_lock(&pd->iosched.lock);
 815         if (bio_data_dir(bio) == READ)
 816                 bio_list_add(&pd->iosched.read_queue, bio);
 817         else
 818                 bio_list_add(&pd->iosched.write_queue, bio);
 819         spin_unlock(&pd->iosched.lock);
 820
 821         atomic_set(&pd->iosched.attention, 1);
 822         wake_up(&pd->wqueue);
 823 }
 824
 825 /*
 826  * Process the queued read/write requests. This function handles special
 827  * requirements for CDRW drives:
 828  * - A cache flush command must be inserted before a read request if the
 829  *   previous request was a write.
 830  * - Switching between reading and writing is slow, so don't do it more often
 831  *   than necessary.
 832  * - Optimize for throughput at the expense of latency. This means that streaming
 833  *   writes will never be interrupted by a read, but if the drive has to seek
 834  *   before the next write, switch to reading instead if there are any pending
 835  *   read requests.
 836  * - Set the read speed according to current usage pattern. When only reading
 837  *   from the device, it's best to use the highest possible read speed, but
 838  *   when switching often between reading and writing, it's better to have the
 839  *   same read and write speeds.
 840  */
 841 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
 842 {
 843
 844         if (atomic_read(&pd->iosched.attention) == 0)
 845                 return;
 846         atomic_set(&pd->iosched.attention, 0);
 847
 848         for (;;) {
 849                 struct bio *bio;
 850                 int reads_queued, writes_queued;
 851
 852                 spin_lock(&pd->iosched.lock);
 853                 reads_queued = !bio_list_empty(&pd->iosched.read_queue);
 854                 writes_queued = !bio_list_empty(&pd->iosched.write_queue);
 855                 spin_unlock(&pd->iosched.lock);
 856
 857                 if (!reads_queued && !writes_queued)
 858                         break;
 859
 860                 if (pd->iosched.writing) {
 861                         int need_write_seek = 1;
 862                         spin_lock(&pd->iosched.lock);
 863                         bio = bio_list_peek(&pd->iosched.write_queue);
 864                         spin_unlock(&pd->iosched.lock);
 865                         if (bio && (bio->bi_iter.bi_sector ==
 866                                     pd->iosched.last_write))
 867                                 need_write_seek = 0;
 868                         if (need_write_seek && reads_queued) {
 869                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 870                                         pkt_dbg(2, pd, "write, waiting\n");
 871                                         break;
 872                                 }
 873                                 pkt_flush_cache(pd);
 874                                 pd->iosched.writing = 0;
 875                         }
 876                 } else {
 877                         if (!reads_queued && writes_queued) {
 878                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 879                                         pkt_dbg(2, pd, "read, waiting\n");
 880                                         break;
 881                                 }
 882                                 pd->iosched.writing = 1;
 883                         }
 884                 }
 885
 886                 spin_lock(&pd->iosched.lock);
 887                 if (pd->iosched.writing)
 888                         bio = bio_list_pop(&pd->iosched.write_queue);
 889                 else
 890                         bio = bio_list_pop(&pd->iosched.read_queue);
 891                 spin_unlock(&pd->iosched.lock);
 892
 893                 if (!bio)
 894                         continue;
 895
 896                 if (bio_data_dir(bio) == READ)
 897                         pd->iosched.successive_reads +=
 898                                 bio->bi_iter.bi_size >> 10;
 899                 else {
 900                         pd->iosched.successive_reads = 0;
 901                         pd->iosched.last_write = bio_end_sector(bio);
 902                 }
 903                 if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
 904                         if (pd->read_speed == pd->write_speed) {
 905                                 pd->read_speed = MAX_SPEED;
 906                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 907                         }
 908                 } else {
 909                         if (pd->read_speed != pd->write_speed) {
 910                                 pd->read_speed = pd->write_speed;
 911                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 912                         }
 913                 }
 914
 915                 atomic_inc(&pd->cdrw.pending_bios);
 916                 submit_bio_noacct(bio);
 917         }
 918 }
 919
 920 /*
 921  * Special care is needed if the underlying block device has a small
 922  * max_phys_segments value.
 923  */
 924 static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
 925 {
 926         if ((pd->settings.size << 9) / CD_FRAMESIZE
 927             <= queue_max_segments(q)) {
 928                 /*
 929                  * The cdrom device can handle one segment/frame
 930                  */
 931                 clear_bit(PACKET_MERGE_SEGS, &pd->flags);
 932                 return 0;
 933         } else if ((pd->settings.size << 9) / PAGE_SIZE
 934                    <= queue_max_segments(q)) {
 935                 /*
 936                  * We can handle this case at the expense of some extra memory
 937                  * copies during write operations
 938                  */
 939                 set_bit(PACKET_MERGE_SEGS, &pd->flags);
 940                 return 0;
 941         } else {
 942                 pkt_err(pd, "cdrom max_phys_segments too small\n");
 943                 return -EIO;
 944         }
 945 }
 946
 947 static void pkt_end_io_read(struct bio *bio)
 948 {
 949         struct packet_data *pkt = bio->bi_private;
 950         struct pktcdvd_device *pd = pkt->pd;
 951         BUG_ON(!pd);
 952
 953         pkt_dbg(2, pd, "bio=%p sec0=%llx sec=%llx err=%d\n",
 954                 bio, (unsigned long long)pkt->sector,
 955                 (unsigned long long)bio->bi_iter.bi_sector, bio->bi_status);
 956
 957         if (bio->bi_status)
 958                 atomic_inc(&pkt->io_errors);
 959         if (atomic_dec_and_test(&pkt->io_wait)) {
 960                 atomic_inc(&pkt->run_sm);
 961                 wake_up(&pd->wqueue);
 962         }
 963         pkt_bio_finished(pd);
 964 }
 965
 966 static void pkt_end_io_packet_write(struct bio *bio)
 967 {
 968         struct packet_data *pkt = bio->bi_private;
 969         struct pktcdvd_device *pd = pkt->pd;
 970         BUG_ON(!pd);
 971
 972         pkt_dbg(2, pd, "id=%d, err=%d\n", pkt->id, bio->bi_status);
 973
 974         pd->stats.pkt_ended++;
 975
 976         pkt_bio_finished(pd);
 977         atomic_dec(&pkt->io_wait);
 978         atomic_inc(&pkt->run_sm);
 979         wake_up(&pd->wqueue);
 980 }
 981
 982 /*
 983  * Schedule reads for the holes in a packet
 984  */
 985 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
 986 {
 987         int frames_read = 0;
 988         struct bio *bio;
 989         int f;
 990         char written[PACKET_MAX_SIZE];
 991
 992         BUG_ON(bio_list_empty(&pkt->orig_bios));
 993
 994         atomic_set(&pkt->io_wait, 0);
 995         atomic_set(&pkt->io_errors, 0);
 996
 997         /*
 998          * Figure out which frames we need to read before we can write.
 999          */
1000         memset(written, 0, sizeof(written));
1001         spin_lock(&pkt->lock);
1002         bio_list_for_each(bio, &pkt->orig_bios) {
1003                 int first_frame = (bio->bi_iter.bi_sector - pkt->sector) /
1004                         (CD_FRAMESIZE >> 9);
1005                 int num_frames = bio->bi_iter.bi_size / CD_FRAMESIZE;
1006                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1007                 BUG_ON(first_frame < 0);
1008                 BUG_ON(first_frame + num_frames > pkt->frames);
1009                 for (f = first_frame; f < first_frame + num_frames; f++)
1010                         written[f] = 1;
1011         }
1012         spin_unlock(&pkt->lock);
1013
1014         if (pkt->cache_valid) {
1015                 pkt_dbg(2, pd, "zone %llx cached\n",
1016                         (unsigned long long)pkt->sector);
1017                 goto out_account;
1018         }
1019
1020         /*
1021          * Schedule reads for missing parts of the packet.
1022          */
1023         for (f = 0; f < pkt->frames; f++) {
1024                 int p, offset;
1025
1026                 if (written[f])
1027                         continue;
1028
1029                 bio = pkt->r_bios[f];
1030                 bio_reset(bio);
1031                 bio->bi_iter.bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1032                 bio_set_dev(bio, pd->bdev);
1033                 bio->bi_end_io = pkt_end_io_read;
1034                 bio->bi_private = pkt;
1035
1036                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1037                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1038                 pkt_dbg(2, pd, "Adding frame %d, page:%p offs:%d\n",
1039                         f, pkt->pages[p], offset);
1040                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1041                         BUG();
1042
1043                 atomic_inc(&pkt->io_wait);
1044                 bio_set_op_attrs(bio, REQ_OP_READ, 0);
1045                 pkt_queue_bio(pd, bio);
1046                 frames_read++;
1047         }
1048
1049 out_account:
1050         pkt_dbg(2, pd, "need %d frames for zone %llx\n",
1051                 frames_read, (unsigned long long)pkt->sector);
1052         pd->stats.pkt_started++;
1053         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1054 }
1055
1056 /*
1057  * Find a packet matching zone, or the least recently used packet if
1058  * there is no match.
1059  */
1060 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1061 {
1062         struct packet_data *pkt;
1063
1064         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1065                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1066                         list_del_init(&pkt->list);
1067                         if (pkt->sector != zone)
1068                                 pkt->cache_valid = 0;
1069                         return pkt;
1070                 }
1071         }
1072         BUG();
1073         return NULL;
1074 }
1075
1076 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1077 {
1078         if (pkt->cache_valid) {
1079                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1080         } else {
1081                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1082         }
1083 }
1084
1085 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1086 {
1087 #if PACKET_DEBUG > 1
1088         static const char *state_name[] = {
1089                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1090         };
1091         enum packet_data_state old_state = pkt->state;
1092         pkt_dbg(2, pd, "pkt %2d : s=%6llx %s -> %s\n",
1093                 pkt->id, (unsigned long long)pkt->sector,
1094                 state_name[old_state], state_name[state]);
1095 #endif
1096         pkt->state = state;
1097 }
1098
1099 /*
1100  * Scan the work queue to see if we can start a new packet.
1101  * returns non-zero if any work was done.
1102  */
1103 static int pkt_handle_queue(struct pktcdvd_device *pd)
1104 {
1105         struct packet_data *pkt, *p;
1106         struct bio *bio = NULL;
1107         sector_t zone = 0; /* Suppress gcc warning */
1108         struct pkt_rb_node *node, *first_node;
1109         struct rb_node *n;
1110
1111         atomic_set(&pd->scan_queue, 0);
1112
1113         if (list_empty(&pd->cdrw.pkt_free_list)) {
1114                 pkt_dbg(2, pd, "no pkt\n");
1115                 return 0;
1116         }
1117
1118         /*
1119          * Try to find a zone we are not already working on.
1120          */
1121         spin_lock(&pd->lock);
1122         first_node = pkt_rbtree_find(pd, pd->current_sector);
1123         if (!first_node) {
1124                 n = rb_first(&pd->bio_queue);
1125                 if (n)
1126                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1127         }
1128         node = first_node;
1129         while (node) {
1130                 bio = node->bio;
1131                 zone = get_zone(bio->bi_iter.bi_sector, pd);
1132                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1133                         if (p->sector == zone) {
1134                                 bio = NULL;
1135                                 goto try_next_bio;
1136                         }
1137                 }
1138                 break;
1139 try_next_bio:
1140                 node = pkt_rbtree_next(node);
1141                 if (!node) {
1142                         n = rb_first(&pd->bio_queue);
1143                         if (n)
1144                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1145                 }
1146                 if (node == first_node)
1147                         node = NULL;
1148         }
1149         spin_unlock(&pd->lock);
1150         if (!bio) {
1151                 pkt_dbg(2, pd, "no bio\n");
1152                 return 0;
1153         }
1154
1155         pkt = pkt_get_packet_data(pd, zone);
1156
1157         pd->current_sector = zone + pd->settings.size;
1158         pkt->sector = zone;
1159         BUG_ON(pkt->frames != pd->settings.size >> 2);
1160         pkt->write_size = 0;
1161
1162         /*
1163          * Scan work queue for bios in the same zone and link them
1164          * to this packet.
1165          */
1166         spin_lock(&pd->lock);
1167         pkt_dbg(2, pd, "looking for zone %llx\n", (unsigned long long)zone);
1168         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1169                 bio = node->bio;
1170                 pkt_dbg(2, pd, "found zone=%llx\n", (unsigned long long)
1171                         get_zone(bio->bi_iter.bi_sector, pd));
1172                 if (get_zone(bio->bi_iter.bi_sector, pd) != zone)
1173                         break;
1174                 pkt_rbtree_erase(pd, node);
1175                 spin_lock(&pkt->lock);
1176                 bio_list_add(&pkt->orig_bios, bio);
1177                 pkt->write_size += bio->bi_iter.bi_size / CD_FRAMESIZE;
1178                 spin_unlock(&pkt->lock);
1179         }
1180         /* check write congestion marks, and if bio_queue_size is
1181          * below, wake up any waiters
1182          */
1183         if (pd->congested &&
1184             pd->bio_queue_size <= pd->write_congestion_off) {
1185                 pd->congested = false;
1186                 wake_up_var(&pd->congested);
1187         }
1188         spin_unlock(&pd->lock);
1189
1190         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1191         pkt_set_state(pkt, PACKET_WAITING_STATE);
1192         atomic_set(&pkt->run_sm, 1);
1193
1194         spin_lock(&pd->cdrw.active_list_lock);
1195         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1196         spin_unlock(&pd->cdrw.active_list_lock);
1197
1198         return 1;
1199 }
1200
1201 /**
1202  * bio_list_copy_data - copy contents of data buffers from one chain of bios to
1203  * another
1204  * @src: source bio list
1205  * @dst: destination bio list
1206  *
1207  * Stops when it reaches the end of either the @src list or @dst list - that is,
1208  * copies min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of
1209  * bios).
1210  */
1211 static void bio_list_copy_data(struct bio *dst, struct bio *src)
1212 {
1213         struct bvec_iter src_iter = src->bi_iter;
1214         struct bvec_iter dst_iter = dst->bi_iter;
1215
1216         while (1) {
1217                 if (!src_iter.bi_size) {
1218                         src = src->bi_next;
1219                         if (!src)
1220                                 break;
1221
1222                         src_iter = src->bi_iter;
1223                 }
1224
1225                 if (!dst_iter.bi_size) {
1226                         dst = dst->bi_next;
1227                         if (!dst)
1228                                 break;
1229
1230                         dst_iter = dst->bi_iter;
1231                 }
1232
1233                 bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
1234         }
1235 }
1236
1237 /*
1238  * Assemble a bio to write one packet and queue the bio for processing
1239  * by the underlying block device.
1240  */
1241 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1242 {
1243         int f;
1244
1245         bio_reset(pkt->w_bio);
1246         pkt->w_bio->bi_iter.bi_sector = pkt->sector;
1247         bio_set_dev(pkt->w_bio, pd->bdev);
1248         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1249         pkt->w_bio->bi_private = pkt;
1250
1251         /* XXX: locking? */
1252         for (f = 0; f < pkt->frames; f++) {
1253                 struct page *page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1254                 unsigned offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1255
1256                 if (!bio_add_page(pkt->w_bio, page, CD_FRAMESIZE, offset))
1257                         BUG();
1258         }
1259         pkt_dbg(2, pd, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
1260
1261         /*
1262          * Fill-in bvec with data from orig_bios.
1263          */
1264         spin_lock(&pkt->lock);
1265         bio_list_copy_data(pkt->w_bio, pkt->orig_bios.head);
1266
1267         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1268         spin_unlock(&pkt->lock);
1269
1270         pkt_dbg(2, pd, "Writing %d frames for zone %llx\n",
1271                 pkt->write_size, (unsigned long long)pkt->sector);
1272
1273         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames))
1274                 pkt->cache_valid = 1;
1275         else
1276                 pkt->cache_valid = 0;
1277
1278         /* Start the write request */
1279         atomic_set(&pkt->io_wait, 1);
1280         bio_set_op_attrs(pkt->w_bio, REQ_OP_WRITE, 0);
1281         pkt_queue_bio(pd, pkt->w_bio);
1282 }
1283
1284 static void pkt_finish_packet(struct packet_data *pkt, blk_status_t status)
1285 {
1286         struct bio *bio;
1287
1288         if (status)
1289                 pkt->cache_valid = 0;
1290
1291         /* Finish all bios corresponding to this packet */
1292         while ((bio = bio_list_pop(&pkt->orig_bios))) {
1293                 bio->bi_status = status;
1294                 bio_endio(bio);
1295         }
1296 }
1297
1298 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1299 {
1300         pkt_dbg(2, pd, "pkt %d\n", pkt->id);
1301
1302         for (;;) {
1303                 switch (pkt->state) {
1304                 case PACKET_WAITING_STATE:
1305                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1306                                 return;
1307
1308                         pkt->sleep_time = 0;
1309                         pkt_gather_data(pd, pkt);
1310                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1311                         break;
1312
1313                 case PACKET_READ_WAIT_STATE:
1314                         if (atomic_read(&pkt->io_wait) > 0)
1315                                 return;
1316
1317                         if (atomic_read(&pkt->io_errors) > 0) {
1318                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1319                         } else {
1320                                 pkt_start_write(pd, pkt);
1321                         }
1322                         break;
1323
1324                 case PACKET_WRITE_WAIT_STATE:
1325                         if (atomic_read(&pkt->io_wait) > 0)
1326                                 return;
1327
1328                         if (!pkt->w_bio->bi_status) {
1329                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1330                         } else {
1331                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1332                         }
1333                         break;
1334
1335                 case PACKET_RECOVERY_STATE:
1336                         pkt_dbg(2, pd, "No recovery possible\n");
1337                         pkt_set_state(pkt, PACKET_FINISHED_STATE);
1338                         break;
1339
1340                 case PACKET_FINISHED_STATE:
1341                         pkt_finish_packet(pkt, pkt->w_bio->bi_status);
1342                         return;
1343
1344                 default:
1345                         BUG();
1346                         break;
1347                 }
1348         }
1349 }
1350
1351 static void pkt_handle_packets(struct pktcdvd_device *pd)
1352 {
1353         struct packet_data *pkt, *next;
1354
1355         /*
1356          * Run state machine for active packets
1357          */
1358         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1359                 if (atomic_read(&pkt->run_sm) > 0) {
1360                         atomic_set(&pkt->run_sm, 0);
1361                         pkt_run_state_machine(pd, pkt);
1362                 }
1363         }
1364
1365         /*
1366          * Move no longer active packets to the free list
1367          */
1368         spin_lock(&pd->cdrw.active_list_lock);
1369         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1370                 if (pkt->state == PACKET_FINISHED_STATE) {
1371                         list_del(&pkt->list);
1372                         pkt_put_packet_data(pd, pkt);
1373                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1374                         atomic_set(&pd->scan_queue, 1);
1375                 }
1376         }
1377         spin_unlock(&pd->cdrw.active_list_lock);
1378 }
1379
1380 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1381 {
1382         struct packet_data *pkt;
1383         int i;
1384
1385         for (i = 0; i < PACKET_NUM_STATES; i++)
1386                 states[i] = 0;
1387
1388         spin_lock(&pd->cdrw.active_list_lock);
1389         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1390                 states[pkt->state]++;
1391         }
1392         spin_unlock(&pd->cdrw.active_list_lock);
1393 }
1394
1395 /*
1396  * kcdrwd is woken up when writes have been queued for one of our
1397  * registered devices
1398  */
1399 static int kcdrwd(void *foobar)
1400 {
1401         struct pktcdvd_device *pd = foobar;
1402         struct packet_data *pkt;
1403         long min_sleep_time, residue;
1404
1405         set_user_nice(current, MIN_NICE);
1406         set_freezable();
1407
1408         for (;;) {
1409                 DECLARE_WAITQUEUE(wait, current);
1410
1411                 /*
1412                  * Wait until there is something to do
1413                  */
1414                 add_wait_queue(&pd->wqueue, &wait);
1415                 for (;;) {
1416                         set_current_state(TASK_INTERRUPTIBLE);
1417
1418                         /* Check if we need to run pkt_handle_queue */
1419                         if (atomic_read(&pd->scan_queue) > 0)
1420                                 goto work_to_do;
1421
1422                         /* Check if we need to run the state machine for some packet */
1423                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1424                                 if (atomic_read(&pkt->run_sm) > 0)
1425                                         goto work_to_do;
1426                         }
1427
1428                         /* Check if we need to process the iosched queues */
1429                         if (atomic_read(&pd->iosched.attention) != 0)
1430                                 goto work_to_do;
1431
1432                         /* Otherwise, go to sleep */
1433                         if (PACKET_DEBUG > 1) {
1434                                 int states[PACKET_NUM_STATES];
1435                                 pkt_count_states(pd, states);
1436                                 pkt_dbg(2, pd, "i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1437                                         states[0], states[1], states[2],
1438                                         states[3], states[4], states[5]);
1439                         }
1440
1441                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1442                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1443                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1444                                         min_sleep_time = pkt->sleep_time;
1445                         }
1446
1447                         pkt_dbg(2, pd, "sleeping\n");
1448                         residue = schedule_timeout(min_sleep_time);
1449                         pkt_dbg(2, pd, "wake up\n");
1450
1451                         /* make swsusp happy with our thread */
1452                         try_to_freeze();
1453
1454                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1455                                 if (!pkt->sleep_time)
1456                                         continue;
1457                                 pkt->sleep_time -= min_sleep_time - residue;
1458                                 if (pkt->sleep_time <= 0) {
1459                                         pkt->sleep_time = 0;
1460                                         atomic_inc(&pkt->run_sm);
1461                                 }
1462                         }
1463
1464                         if (kthread_should_stop())
1465                                 break;
1466                 }
1467 work_to_do:
1468                 set_current_state(TASK_RUNNING);
1469                 remove_wait_queue(&pd->wqueue, &wait);
1470
1471                 if (kthread_should_stop())
1472                         break;
1473
1474                 /*
1475                  * if pkt_handle_queue returns true, we can queue
1476                  * another request.
1477                  */
1478                 while (pkt_handle_queue(pd))
1479                         ;
1480
1481                 /*
1482                  * Handle packet state machine
1483                  */
1484                 pkt_handle_packets(pd);
1485
1486                 /*
1487                  * Handle iosched queues
1488                  */
1489                 pkt_iosched_process_queue(pd);
1490         }
1491
1492         return 0;
1493 }
1494
1495 static void pkt_print_settings(struct pktcdvd_device *pd)
1496 {
1497         pkt_info(pd, "%s packets, %u blocks, Mode-%c disc\n",
1498                  pd->settings.fp ? "Fixed" : "Variable",
1499                  pd->settings.size >> 2,
1500                  pd->settings.block_mode == 8 ? '1' : '2');
1501 }
1502
1503 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1504 {
1505         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1506
1507         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1508         cgc->cmd[2] = page_code | (page_control << 6);
1509         cgc->cmd[7] = cgc->buflen >> 8;
1510         cgc->cmd[8] = cgc->buflen & 0xff;
1511         cgc->data_direction = CGC_DATA_READ;
1512         return pkt_generic_packet(pd, cgc);
1513 }
1514
1515 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1516 {
1517         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1518         memset(cgc->buffer, 0, 2);
1519         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1520         cgc->cmd[1] = 0x10;             /* PF */
1521         cgc->cmd[7] = cgc->buflen >> 8;
1522         cgc->cmd[8] = cgc->buflen & 0xff;
1523         cgc->data_direction = CGC_DATA_WRITE;
1524         return pkt_generic_packet(pd, cgc);
1525 }
1526
1527 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1528 {
1529         struct packet_command cgc;
1530         int ret;
1531
1532         /* set up command and get the disc info */
1533         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1534         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1535         cgc.cmd[8] = cgc.buflen = 2;
1536         cgc.quiet = 1;
1537
1538         ret = pkt_generic_packet(pd, &cgc);
1539         if (ret)
1540                 return ret;
1541
1542         /* not all drives have the same disc_info length, so requeue
1543          * packet with the length the drive tells us it can supply
1544          */
1545         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1546                      sizeof(di->disc_information_length);
1547
1548         if (cgc.buflen > sizeof(disc_information))
1549                 cgc.buflen = sizeof(disc_information);
1550
1551         cgc.cmd[8] = cgc.buflen;
1552         return pkt_generic_packet(pd, &cgc);
1553 }
1554
1555 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1556 {
1557         struct packet_command cgc;
1558         int ret;
1559
1560         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1561         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1562         cgc.cmd[1] = type & 3;
1563         cgc.cmd[4] = (track & 0xff00) >> 8;
1564         cgc.cmd[5] = track & 0xff;
1565         cgc.cmd[8] = 8;
1566         cgc.quiet = 1;
1567
1568         ret = pkt_generic_packet(pd, &cgc);
1569         if (ret)
1570                 return ret;
1571
1572         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1573                      sizeof(ti->track_information_length);
1574
1575         if (cgc.buflen > sizeof(track_information))
1576                 cgc.buflen = sizeof(track_information);
1577
1578         cgc.cmd[8] = cgc.buflen;
1579         return pkt_generic_packet(pd, &cgc);
1580 }
1581
1582 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1583                                                 long *last_written)
1584 {
1585         disc_information di;
1586         track_information ti;
1587         __u32 last_track;
1588         int ret;
1589
1590         ret = pkt_get_disc_info(pd, &di);
1591         if (ret)
1592                 return ret;
1593
1594         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1595         ret = pkt_get_track_info(pd, last_track, 1, &ti);
1596         if (ret)
1597                 return ret;
1598
1599         /* if this track is blank, try the previous. */
1600         if (ti.blank) {
1601                 last_track--;
1602                 ret = pkt_get_track_info(pd, last_track, 1, &ti);
1603                 if (ret)
1604                         return ret;
1605         }
1606
1607         /* if last recorded field is valid, return it. */
1608         if (ti.lra_v) {
1609                 *last_written = be32_to_cpu(ti.last_rec_address);
1610         } else {
1611                 /* make it up instead */
1612                 *last_written = be32_to_cpu(ti.track_start) +
1613                                 be32_to_cpu(ti.track_size);
1614                 if (ti.free_blocks)
1615                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1616         }
1617         return 0;
1618 }
1619
1620 /*
1621  * write mode select package based on pd->settings
1622  */
1623 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1624 {
1625         struct packet_command cgc;
1626         struct scsi_sense_hdr sshdr;
1627         write_param_page *wp;
1628         char buffer[128];
1629         int ret, size;
1630
1631         /* doesn't apply to DVD+RW or DVD-RAM */
1632         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1633                 return 0;
1634
1635         memset(buffer, 0, sizeof(buffer));
1636         init_cdrom_command(&cgc, buffer, sizeof(*wp), 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         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1645         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1646         if (size > sizeof(buffer))
1647                 size = sizeof(buffer);
1648
1649         /*
1650          * now get it all
1651          */
1652         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1653         cgc.sshdr = &sshdr;
1654         ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1655         if (ret) {
1656                 pkt_dump_sense(pd, &cgc);
1657                 return ret;
1658         }
1659
1660         /*
1661          * write page is offset header + block descriptor length
1662          */
1663         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1664
1665         wp->fp = pd->settings.fp;
1666         wp->track_mode = pd->settings.track_mode;
1667         wp->write_type = pd->settings.write_type;
1668         wp->data_block_type = pd->settings.block_mode;
1669
1670         wp->multi_session = 0;
1671
1672 #ifdef PACKET_USE_LS
1673         wp->link_size = 7;
1674         wp->ls_v = 1;
1675 #endif
1676
1677         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1678                 wp->session_format = 0;
1679                 wp->subhdr2 = 0x20;
1680         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1681                 wp->session_format = 0x20;
1682                 wp->subhdr2 = 8;
1683 #if 0
1684                 wp->mcn[0] = 0x80;
1685                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1686 #endif
1687         } else {
1688                 /*
1689                  * paranoia
1690                  */
1691                 pkt_err(pd, "write mode wrong %d\n", wp->data_block_type);
1692                 return 1;
1693         }
1694         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1695
1696         cgc.buflen = cgc.cmd[8] = size;
1697         ret = pkt_mode_select(pd, &cgc);
1698         if (ret) {
1699                 pkt_dump_sense(pd, &cgc);
1700                 return ret;
1701         }
1702
1703         pkt_print_settings(pd);
1704         return 0;
1705 }
1706
1707 /*
1708  * 1 -- we can write to this track, 0 -- we can't
1709  */
1710 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1711 {
1712         switch (pd->mmc3_profile) {
1713                 case 0x1a: /* DVD+RW */
1714                 case 0x12: /* DVD-RAM */
1715                         /* The track is always writable on DVD+RW/DVD-RAM */
1716                         return 1;
1717                 default:
1718                         break;
1719         }
1720
1721         if (!ti->packet || !ti->fp)
1722                 return 0;
1723
1724         /*
1725          * "good" settings as per Mt Fuji.
1726          */
1727         if (ti->rt == 0 && ti->blank == 0)
1728                 return 1;
1729
1730         if (ti->rt == 0 && ti->blank == 1)
1731                 return 1;
1732
1733         if (ti->rt == 1 && ti->blank == 0)
1734                 return 1;
1735
1736         pkt_err(pd, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1737         return 0;
1738 }
1739
1740 /*
1741  * 1 -- we can write to this disc, 0 -- we can't
1742  */
1743 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1744 {
1745         switch (pd->mmc3_profile) {
1746                 case 0x0a: /* CD-RW */
1747                 case 0xffff: /* MMC3 not supported */
1748                         break;
1749                 case 0x1a: /* DVD+RW */
1750                 case 0x13: /* DVD-RW */
1751                 case 0x12: /* DVD-RAM */
1752                         return 1;
1753                 default:
1754                         pkt_dbg(2, pd, "Wrong disc profile (%x)\n",
1755                                 pd->mmc3_profile);
1756                         return 0;
1757         }
1758
1759         /*
1760          * for disc type 0xff we should probably reserve a new track.
1761          * but i'm not sure, should we leave this to user apps? probably.
1762          */
1763         if (di->disc_type == 0xff) {
1764                 pkt_notice(pd, "unknown disc - no track?\n");
1765                 return 0;
1766         }
1767
1768         if (di->disc_type != 0x20 && di->disc_type != 0) {
1769                 pkt_err(pd, "wrong disc type (%x)\n", di->disc_type);
1770                 return 0;
1771         }
1772
1773         if (di->erasable == 0) {
1774                 pkt_notice(pd, "disc not erasable\n");
1775                 return 0;
1776         }
1777
1778         if (di->border_status == PACKET_SESSION_RESERVED) {
1779                 pkt_err(pd, "can't write to last track (reserved)\n");
1780                 return 0;
1781         }
1782
1783         return 1;
1784 }
1785
1786 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1787 {
1788         struct packet_command cgc;
1789         unsigned char buf[12];
1790         disc_information di;
1791         track_information ti;
1792         int ret, track;
1793
1794         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1795         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1796         cgc.cmd[8] = 8;
1797         ret = pkt_generic_packet(pd, &cgc);
1798         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1799
1800         memset(&di, 0, sizeof(disc_information));
1801         memset(&ti, 0, sizeof(track_information));
1802
1803         ret = pkt_get_disc_info(pd, &di);
1804         if (ret) {
1805                 pkt_err(pd, "failed get_disc\n");
1806                 return ret;
1807         }
1808
1809         if (!pkt_writable_disc(pd, &di))
1810                 return -EROFS;
1811
1812         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1813
1814         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1815         ret = pkt_get_track_info(pd, track, 1, &ti);
1816         if (ret) {
1817                 pkt_err(pd, "failed get_track\n");
1818                 return ret;
1819         }
1820
1821         if (!pkt_writable_track(pd, &ti)) {
1822                 pkt_err(pd, "can't write to this track\n");
1823                 return -EROFS;
1824         }
1825
1826         /*
1827          * we keep packet size in 512 byte units, makes it easier to
1828          * deal with request calculations.
1829          */
1830         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1831         if (pd->settings.size == 0) {
1832                 pkt_notice(pd, "detected zero packet size!\n");
1833                 return -ENXIO;
1834         }
1835         if (pd->settings.size > PACKET_MAX_SECTORS) {
1836                 pkt_err(pd, "packet size is too big\n");
1837                 return -EROFS;
1838         }
1839         pd->settings.fp = ti.fp;
1840         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1841
1842         if (ti.nwa_v) {
1843                 pd->nwa = be32_to_cpu(ti.next_writable);
1844                 set_bit(PACKET_NWA_VALID, &pd->flags);
1845         }
1846
1847         /*
1848          * in theory we could use lra on -RW media as well and just zero
1849          * blocks that haven't been written yet, but in practice that
1850          * is just a no-go. we'll use that for -R, naturally.
1851          */
1852         if (ti.lra_v) {
1853                 pd->lra = be32_to_cpu(ti.last_rec_address);
1854                 set_bit(PACKET_LRA_VALID, &pd->flags);
1855         } else {
1856                 pd->lra = 0xffffffff;
1857                 set_bit(PACKET_LRA_VALID, &pd->flags);
1858         }
1859
1860         /*
1861          * fine for now
1862          */
1863         pd->settings.link_loss = 7;
1864         pd->settings.write_type = 0;    /* packet */
1865         pd->settings.track_mode = ti.track_mode;
1866
1867         /*
1868          * mode1 or mode2 disc
1869          */
1870         switch (ti.data_mode) {
1871                 case PACKET_MODE1:
1872                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
1873                         break;
1874                 case PACKET_MODE2:
1875                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
1876                         break;
1877                 default:
1878                         pkt_err(pd, "unknown data mode\n");
1879                         return -EROFS;
1880         }
1881         return 0;
1882 }
1883
1884 /*
1885  * enable/disable write caching on drive
1886  */
1887 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
1888                                                 int set)
1889 {
1890         struct packet_command cgc;
1891         struct scsi_sense_hdr sshdr;
1892         unsigned char buf[64];
1893         int ret;
1894
1895         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1896         cgc.sshdr = &sshdr;
1897         cgc.buflen = pd->mode_offset + 12;
1898
1899         /*
1900          * caching mode page might not be there, so quiet this command
1901          */
1902         cgc.quiet = 1;
1903
1904         ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0);
1905         if (ret)
1906                 return ret;
1907
1908         buf[pd->mode_offset + 10] |= (!!set << 2);
1909
1910         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
1911         ret = pkt_mode_select(pd, &cgc);
1912         if (ret) {
1913                 pkt_err(pd, "write caching control failed\n");
1914                 pkt_dump_sense(pd, &cgc);
1915         } else if (!ret && set)
1916                 pkt_notice(pd, "enabled write caching\n");
1917         return ret;
1918 }
1919
1920 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1921 {
1922         struct packet_command cgc;
1923
1924         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1925         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1926         cgc.cmd[4] = lockflag ? 1 : 0;
1927         return pkt_generic_packet(pd, &cgc);
1928 }
1929
1930 /*
1931  * Returns drive maximum write speed
1932  */
1933 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1934                                                 unsigned *write_speed)
1935 {
1936         struct packet_command cgc;
1937         struct scsi_sense_hdr sshdr;
1938         unsigned char buf[256+18];
1939         unsigned char *cap_buf;
1940         int ret, offset;
1941
1942         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1943         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1944         cgc.sshdr = &sshdr;
1945
1946         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1947         if (ret) {
1948                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
1949                              sizeof(struct mode_page_header);
1950                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1951                 if (ret) {
1952                         pkt_dump_sense(pd, &cgc);
1953                         return ret;
1954                 }
1955         }
1956
1957         offset = 20;                        /* Obsoleted field, used by older drives */
1958         if (cap_buf[1] >= 28)
1959                 offset = 28;                /* Current write speed selected */
1960         if (cap_buf[1] >= 30) {
1961                 /* If the drive reports at least one "Logical Unit Write
1962                  * Speed Performance Descriptor Block", use the information
1963                  * in the first block. (contains the highest speed)
1964                  */
1965                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
1966                 if (num_spdb > 0)
1967                         offset = 34;
1968         }
1969
1970         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
1971         return 0;
1972 }
1973
1974 /* These tables from cdrecord - I don't have orange book */
1975 /* standard speed CD-RW (1-4x) */
1976 static char clv_to_speed[16] = {
1977         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1978            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1979 };
1980 /* high speed CD-RW (-10x) */
1981 static char hs_clv_to_speed[16] = {
1982         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1983            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1984 };
1985 /* ultra high speed CD-RW */
1986 static char us_clv_to_speed[16] = {
1987         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1988            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
1989 };
1990
1991 /*
1992  * reads the maximum media speed from ATIP
1993  */
1994 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
1995                                                 unsigned *speed)
1996 {
1997         struct packet_command cgc;
1998         struct scsi_sense_hdr sshdr;
1999         unsigned char buf[64];
2000         unsigned int size, st, sp;
2001         int ret;
2002
2003         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2004         cgc.sshdr = &sshdr;
2005         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2006         cgc.cmd[1] = 2;
2007         cgc.cmd[2] = 4; /* READ ATIP */
2008         cgc.cmd[8] = 2;
2009         ret = pkt_generic_packet(pd, &cgc);
2010         if (ret) {
2011                 pkt_dump_sense(pd, &cgc);
2012                 return ret;
2013         }
2014         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2015         if (size > sizeof(buf))
2016                 size = sizeof(buf);
2017
2018         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2019         cgc.sshdr = &sshdr;
2020         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2021         cgc.cmd[1] = 2;
2022         cgc.cmd[2] = 4;
2023         cgc.cmd[8] = size;
2024         ret = pkt_generic_packet(pd, &cgc);
2025         if (ret) {
2026                 pkt_dump_sense(pd, &cgc);
2027                 return ret;
2028         }
2029
2030         if (!(buf[6] & 0x40)) {
2031                 pkt_notice(pd, "disc type is not CD-RW\n");
2032                 return 1;
2033         }
2034         if (!(buf[6] & 0x4)) {
2035                 pkt_notice(pd, "A1 values on media are not valid, maybe not CDRW?\n");
2036                 return 1;
2037         }
2038
2039         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2040
2041         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2042
2043         /* Info from cdrecord */
2044         switch (st) {
2045                 case 0: /* standard speed */
2046                         *speed = clv_to_speed[sp];
2047                         break;
2048                 case 1: /* high speed */
2049                         *speed = hs_clv_to_speed[sp];
2050                         break;
2051                 case 2: /* ultra high speed */
2052                         *speed = us_clv_to_speed[sp];
2053                         break;
2054                 default:
2055                         pkt_notice(pd, "unknown disc sub-type %d\n", st);
2056                         return 1;
2057         }
2058         if (*speed) {
2059                 pkt_info(pd, "maximum media speed: %d\n", *speed);
2060                 return 0;
2061         } else {
2062                 pkt_notice(pd, "unknown speed %d for sub-type %d\n", sp, st);
2063                 return 1;
2064         }
2065 }
2066
2067 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2068 {
2069         struct packet_command cgc;
2070         struct scsi_sense_hdr sshdr;
2071         int ret;
2072
2073         pkt_dbg(2, pd, "Performing OPC\n");
2074
2075         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2076         cgc.sshdr = &sshdr;
2077         cgc.timeout = 60*HZ;
2078         cgc.cmd[0] = GPCMD_SEND_OPC;
2079         cgc.cmd[1] = 1;
2080         ret = pkt_generic_packet(pd, &cgc);
2081         if (ret)
2082                 pkt_dump_sense(pd, &cgc);
2083         return ret;
2084 }
2085
2086 static int pkt_open_write(struct pktcdvd_device *pd)
2087 {
2088         int ret;
2089         unsigned int write_speed, media_write_speed, read_speed;
2090
2091         ret = pkt_probe_settings(pd);
2092         if (ret) {
2093                 pkt_dbg(2, pd, "failed probe\n");
2094                 return ret;
2095         }
2096
2097         ret = pkt_set_write_settings(pd);
2098         if (ret) {
2099                 pkt_dbg(1, pd, "failed saving write settings\n");
2100                 return -EIO;
2101         }
2102
2103         pkt_write_caching(pd, USE_WCACHING);
2104
2105         ret = pkt_get_max_speed(pd, &write_speed);
2106         if (ret)
2107                 write_speed = 16 * 177;
2108         switch (pd->mmc3_profile) {
2109                 case 0x13: /* DVD-RW */
2110                 case 0x1a: /* DVD+RW */
2111                 case 0x12: /* DVD-RAM */
2112                         pkt_dbg(1, pd, "write speed %ukB/s\n", write_speed);
2113                         break;
2114                 default:
2115                         ret = pkt_media_speed(pd, &media_write_speed);
2116                         if (ret)
2117                                 media_write_speed = 16;
2118                         write_speed = min(write_speed, media_write_speed * 177);
2119                         pkt_dbg(1, pd, "write speed %ux\n", write_speed / 176);
2120                         break;
2121         }
2122         read_speed = write_speed;
2123
2124         ret = pkt_set_speed(pd, write_speed, read_speed);
2125         if (ret) {
2126                 pkt_dbg(1, pd, "couldn't set write speed\n");
2127                 return -EIO;
2128         }
2129         pd->write_speed = write_speed;
2130         pd->read_speed = read_speed;
2131
2132         ret = pkt_perform_opc(pd);
2133         if (ret) {
2134                 pkt_dbg(1, pd, "Optimum Power Calibration failed\n");
2135         }
2136
2137         return 0;
2138 }
2139
2140 /*
2141  * called at open time.
2142  */
2143 static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2144 {
2145         int ret;
2146         long lba;
2147         struct request_queue *q;
2148         struct block_device *bdev;
2149
2150         /*
2151          * We need to re-open the cdrom device without O_NONBLOCK to be able
2152          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2153          * so open should not fail.
2154          */
2155         bdev = blkdev_get_by_dev(pd->bdev->bd_dev, FMODE_READ | FMODE_EXCL, pd);
2156         if (IS_ERR(bdev)) {
2157                 ret = PTR_ERR(bdev);
2158                 goto out;
2159         }
2160
2161         ret = pkt_get_last_written(pd, &lba);
2162         if (ret) {
2163                 pkt_err(pd, "pkt_get_last_written failed\n");
2164                 goto out_putdev;
2165         }
2166
2167         set_capacity(pd->disk, lba << 2);
2168         set_capacity_and_notify(pd->bdev->bd_disk, lba << 2);
2169
2170         q = bdev_get_queue(pd->bdev);
2171         if (write) {
2172                 ret = pkt_open_write(pd);
2173                 if (ret)
2174                         goto out_putdev;
2175                 /*
2176                  * Some CDRW drives can not handle writes larger than one packet,
2177                  * even if the size is a multiple of the packet size.
2178                  */
2179                 blk_queue_max_hw_sectors(q, pd->settings.size);
2180                 set_bit(PACKET_WRITABLE, &pd->flags);
2181         } else {
2182                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2183                 clear_bit(PACKET_WRITABLE, &pd->flags);
2184         }
2185
2186         ret = pkt_set_segment_merging(pd, q);
2187         if (ret)
2188                 goto out_putdev;
2189
2190         if (write) {
2191                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2192                         pkt_err(pd, "not enough memory for buffers\n");
2193                         ret = -ENOMEM;
2194                         goto out_putdev;
2195                 }
2196                 pkt_info(pd, "%lukB available on disc\n", lba << 1);
2197         }
2198
2199         return 0;
2200
2201 out_putdev:
2202         blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
2203 out:
2204         return ret;
2205 }
2206
2207 /*
2208  * called when the device is closed. makes sure that the device flushes
2209  * the internal cache before we close.
2210  */
2211 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2212 {
2213         if (flush && pkt_flush_cache(pd))
2214                 pkt_dbg(1, pd, "not flushing cache\n");
2215
2216         pkt_lock_door(pd, 0);
2217
2218         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2219         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2220
2221         pkt_shrink_pktlist(pd);
2222 }
2223
2224 static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2225 {
2226         if (dev_minor >= MAX_WRITERS)
2227                 return NULL;
2228
2229         dev_minor = array_index_nospec(dev_minor, MAX_WRITERS);
2230         return pkt_devs[dev_minor];
2231 }
2232
2233 static int pkt_open(struct block_device *bdev, fmode_t mode)
2234 {
2235         struct pktcdvd_device *pd = NULL;
2236         int ret;
2237
2238         mutex_lock(&pktcdvd_mutex);
2239         mutex_lock(&ctl_mutex);
2240         pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2241         if (!pd) {
2242                 ret = -ENODEV;
2243                 goto out;
2244         }
2245         BUG_ON(pd->refcnt < 0);
2246
2247         pd->refcnt++;
2248         if (pd->refcnt > 1) {
2249                 if ((mode & FMODE_WRITE) &&
2250                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2251                         ret = -EBUSY;
2252                         goto out_dec;
2253                 }
2254         } else {
2255                 ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2256                 if (ret)
2257                         goto out_dec;
2258                 /*
2259                  * needed here as well, since ext2 (among others) may change
2260                  * the blocksize at mount time
2261                  */
2262                 set_blocksize(bdev, CD_FRAMESIZE);
2263         }
2264
2265         mutex_unlock(&ctl_mutex);
2266         mutex_unlock(&pktcdvd_mutex);
2267         return 0;
2268
2269 out_dec:
2270         pd->refcnt--;
2271 out:
2272         mutex_unlock(&ctl_mutex);
2273         mutex_unlock(&pktcdvd_mutex);
2274         return ret;
2275 }
2276
2277 static void pkt_close(struct gendisk *disk, fmode_t mode)
2278 {
2279         struct pktcdvd_device *pd = disk->private_data;
2280
2281         mutex_lock(&pktcdvd_mutex);
2282         mutex_lock(&ctl_mutex);
2283         pd->refcnt--;
2284         BUG_ON(pd->refcnt < 0);
2285         if (pd->refcnt == 0) {
2286                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2287                 pkt_release_dev(pd, flush);
2288         }
2289         mutex_unlock(&ctl_mutex);
2290         mutex_unlock(&pktcdvd_mutex);
2291 }
2292
2293
2294 static void pkt_end_io_read_cloned(struct bio *bio)
2295 {
2296         struct packet_stacked_data *psd = bio->bi_private;
2297         struct pktcdvd_device *pd = psd->pd;
2298
2299         psd->bio->bi_status = bio->bi_status;
2300         bio_put(bio);
2301         bio_endio(psd->bio);
2302         mempool_free(psd, &psd_pool);
2303         pkt_bio_finished(pd);
2304 }
2305
2306 static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
2307 {
2308         struct bio *cloned_bio = bio_clone_fast(bio, GFP_NOIO, &pkt_bio_set);
2309         struct packet_stacked_data *psd = mempool_alloc(&psd_pool, GFP_NOIO);
2310
2311         psd->pd = pd;
2312         psd->bio = bio;
2313         bio_set_dev(cloned_bio, pd->bdev);
2314         cloned_bio->bi_private = psd;
2315         cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2316         pd->stats.secs_r += bio_sectors(bio);
2317         pkt_queue_bio(pd, cloned_bio);
2318 }
2319
2320 static void pkt_make_request_write(struct request_queue *q, struct bio *bio)
2321 {
2322         struct pktcdvd_device *pd = q->queuedata;
2323         sector_t zone;
2324         struct packet_data *pkt;
2325         int was_empty, blocked_bio;
2326         struct pkt_rb_node *node;
2327
2328         zone = get_zone(bio->bi_iter.bi_sector, pd);
2329
2330         /*
2331          * If we find a matching packet in state WAITING or READ_WAIT, we can
2332          * just append this bio to that packet.
2333          */
2334         spin_lock(&pd->cdrw.active_list_lock);
2335         blocked_bio = 0;
2336         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2337                 if (pkt->sector == zone) {
2338                         spin_lock(&pkt->lock);
2339                         if ((pkt->state == PACKET_WAITING_STATE) ||
2340                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2341                                 bio_list_add(&pkt->orig_bios, bio);
2342                                 pkt->write_size +=
2343                                         bio->bi_iter.bi_size / CD_FRAMESIZE;
2344                                 if ((pkt->write_size >= pkt->frames) &&
2345                                     (pkt->state == PACKET_WAITING_STATE)) {
2346                                         atomic_inc(&pkt->run_sm);
2347                                         wake_up(&pd->wqueue);
2348                                 }
2349                                 spin_unlock(&pkt->lock);
2350                                 spin_unlock(&pd->cdrw.active_list_lock);
2351                                 return;
2352                         } else {
2353                                 blocked_bio = 1;
2354                         }
2355                         spin_unlock(&pkt->lock);
2356                 }
2357         }
2358         spin_unlock(&pd->cdrw.active_list_lock);
2359
2360         /*
2361          * Test if there is enough room left in the bio work queue
2362          * (queue size >= congestion on mark).
2363          * If not, wait till the work queue size is below the congestion off mark.
2364          */
2365         spin_lock(&pd->lock);
2366         if (pd->write_congestion_on > 0
2367             && pd->bio_queue_size >= pd->write_congestion_on) {
2368                 struct wait_bit_queue_entry wqe;
2369
2370                 init_wait_var_entry(&wqe, &pd->congested, 0);
2371                 for (;;) {
2372                         prepare_to_wait_event(__var_waitqueue(&pd->congested),
2373                                               &wqe.wq_entry,
2374                                               TASK_UNINTERRUPTIBLE);
2375                         if (pd->bio_queue_size <= pd->write_congestion_off)
2376                                 break;
2377                         pd->congested = true;
2378                         spin_unlock(&pd->lock);
2379                         schedule();
2380                         spin_lock(&pd->lock);
2381                 }
2382         }
2383         spin_unlock(&pd->lock);
2384
2385         /*
2386          * No matching packet found. Store the bio in the work queue.
2387          */
2388         node = mempool_alloc(&pd->rb_pool, GFP_NOIO);
2389         node->bio = bio;
2390         spin_lock(&pd->lock);
2391         BUG_ON(pd->bio_queue_size < 0);
2392         was_empty = (pd->bio_queue_size == 0);
2393         pkt_rbtree_insert(pd, node);
2394         spin_unlock(&pd->lock);
2395
2396         /*
2397          * Wake up the worker thread.
2398          */
2399         atomic_set(&pd->scan_queue, 1);
2400         if (was_empty) {
2401                 /* This wake_up is required for correct operation */
2402                 wake_up(&pd->wqueue);
2403         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2404                 /*
2405                  * This wake up is not required for correct operation,
2406                  * but improves performance in some cases.
2407                  */
2408                 wake_up(&pd->wqueue);
2409         }
2410 }
2411
2412 static void pkt_submit_bio(struct bio *bio)
2413 {
2414         struct pktcdvd_device *pd;
2415         char b[BDEVNAME_SIZE];
2416         struct bio *split;
2417
2418         blk_queue_split(&bio);
2419
2420         pd = bio->bi_bdev->bd_disk->queue->queuedata;
2421         if (!pd) {
2422                 pr_err("%s incorrect request queue\n", bio_devname(bio, b));
2423                 goto end_io;
2424         }
2425
2426         pkt_dbg(2, pd, "start = %6llx stop = %6llx\n",
2427                 (unsigned long long)bio->bi_iter.bi_sector,
2428                 (unsigned long long)bio_end_sector(bio));
2429
2430         /*
2431          * Clone READ bios so we can have our own bi_end_io callback.
2432          */
2433         if (bio_data_dir(bio) == READ) {
2434                 pkt_make_request_read(pd, bio);
2435                 return;
2436         }
2437
2438         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2439                 pkt_notice(pd, "WRITE for ro device (%llu)\n",
2440                            (unsigned long long)bio->bi_iter.bi_sector);
2441                 goto end_io;
2442         }
2443
2444         if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2445                 pkt_err(pd, "wrong bio size\n");
2446                 goto end_io;
2447         }
2448
2449         do {
2450                 sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
2451                 sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2452
2453                 if (last_zone != zone) {
2454                         BUG_ON(last_zone != zone + pd->settings.size);
2455
2456                         split = bio_split(bio, last_zone -
2457                                           bio->bi_iter.bi_sector,
2458                                           GFP_NOIO, &pkt_bio_set);
2459                         bio_chain(split, bio);
2460                 } else {
2461                         split = bio;
2462                 }
2463
2464                 pkt_make_request_write(bio->bi_bdev->bd_disk->queue, split);
2465         } while (split != bio);
2466
2467         return;
2468 end_io:
2469         bio_io_error(bio);
2470 }
2471
2472 static void pkt_init_queue(struct pktcdvd_device *pd)
2473 {
2474         struct request_queue *q = pd->disk->queue;
2475
2476         blk_queue_logical_block_size(q, CD_FRAMESIZE);
2477         blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2478         q->queuedata = pd;
2479 }
2480
2481 static int pkt_seq_show(struct seq_file *m, void *p)
2482 {
2483         struct pktcdvd_device *pd = m->private;
2484         char *msg;
2485         char bdev_buf[BDEVNAME_SIZE];
2486         int states[PACKET_NUM_STATES];
2487
2488         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2489                    bdevname(pd->bdev, bdev_buf));
2490
2491         seq_printf(m, "\nSettings:\n");
2492         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2493
2494         if (pd->settings.write_type == 0)
2495                 msg = "Packet";
2496         else
2497                 msg = "Unknown";
2498         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2499
2500         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2501         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2502
2503         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2504
2505         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2506                 msg = "Mode 1";
2507         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2508                 msg = "Mode 2";
2509         else
2510                 msg = "Unknown";
2511         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2512
2513         seq_printf(m, "\nStatistics:\n");
2514         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2515         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2516         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2517         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2518         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2519
2520         seq_printf(m, "\nMisc:\n");
2521         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2522         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2523         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2524         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2525         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2526         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2527
2528         seq_printf(m, "\nQueue state:\n");
2529         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2530         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2531         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2532
2533         pkt_count_states(pd, states);
2534         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2535                    states[0], states[1], states[2], states[3], states[4], states[5]);
2536
2537         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2538                         pd->write_congestion_off,
2539                         pd->write_congestion_on);
2540         return 0;
2541 }
2542
2543 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2544 {
2545         int i;
2546         char b[BDEVNAME_SIZE];
2547         struct block_device *bdev;
2548         struct scsi_device *sdev;
2549
2550         if (pd->pkt_dev == dev) {
2551                 pkt_err(pd, "recursive setup not allowed\n");
2552                 return -EBUSY;
2553         }
2554         for (i = 0; i < MAX_WRITERS; i++) {
2555                 struct pktcdvd_device *pd2 = pkt_devs[i];
2556                 if (!pd2)
2557                         continue;
2558                 if (pd2->bdev->bd_dev == dev) {
2559                         pkt_err(pd, "%s already setup\n",
2560                                 bdevname(pd2->bdev, b));
2561                         return -EBUSY;
2562                 }
2563                 if (pd2->pkt_dev == dev) {
2564                         pkt_err(pd, "can't chain pktcdvd devices\n");
2565                         return -EBUSY;
2566                 }
2567         }
2568
2569         bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_NDELAY, NULL);
2570         if (IS_ERR(bdev))
2571                 return PTR_ERR(bdev);
2572         sdev = scsi_device_from_queue(bdev->bd_disk->queue);
2573         if (!sdev) {
2574                 blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2575                 return -EINVAL;
2576         }
2577         put_device(&sdev->sdev_gendev);
2578
2579         /* This is safe, since we have a reference from open(). */
2580         __module_get(THIS_MODULE);
2581
2582         pd->bdev = bdev;
2583         set_blocksize(bdev, CD_FRAMESIZE);
2584
2585         pkt_init_queue(pd);
2586
2587         atomic_set(&pd->cdrw.pending_bios, 0);
2588         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2589         if (IS_ERR(pd->cdrw.thread)) {
2590                 pkt_err(pd, "can't start kernel thread\n");
2591                 goto out_mem;
2592         }
2593
2594         proc_create_single_data(pd->name, 0, pkt_proc, pkt_seq_show, pd);
2595         pkt_dbg(1, pd, "writer mapped to %s\n", bdevname(bdev, b));
2596         return 0;
2597
2598 out_mem:
2599         blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2600         /* This is safe: open() is still holding a reference. */
2601         module_put(THIS_MODULE);
2602         return -ENOMEM;
2603 }
2604
2605 static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2606 {
2607         struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2608         int ret;
2609
2610         pkt_dbg(2, pd, "cmd %x, dev %d:%d\n",
2611                 cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2612
2613         mutex_lock(&pktcdvd_mutex);
2614         switch (cmd) {
2615         case CDROMEJECT:
2616                 /*
2617                  * The door gets locked when the device is opened, so we
2618                  * have to unlock it or else the eject command fails.
2619                  */
2620                 if (pd->refcnt == 1)
2621                         pkt_lock_door(pd, 0);
2622                 fallthrough;
2623         /*
2624          * forward selected CDROM ioctls to CD-ROM, for UDF
2625          */
2626         case CDROMMULTISESSION:
2627         case CDROMREADTOCENTRY:
2628         case CDROM_LAST_WRITTEN:
2629         case CDROM_SEND_PACKET:
2630         case SCSI_IOCTL_SEND_COMMAND:
2631                 if (!bdev->bd_disk->fops->ioctl)
2632                         ret = -ENOTTY;
2633                 else
2634                         ret = bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
2635                 break;
2636         default:
2637                 pkt_dbg(2, pd, "Unknown ioctl (%x)\n", cmd);
2638                 ret = -ENOTTY;
2639         }
2640         mutex_unlock(&pktcdvd_mutex);
2641
2642         return ret;
2643 }
2644
2645 static unsigned int pkt_check_events(struct gendisk *disk,
2646                                      unsigned int clearing)
2647 {
2648         struct pktcdvd_device *pd = disk->private_data;
2649         struct gendisk *attached_disk;
2650
2651         if (!pd)
2652                 return 0;
2653         if (!pd->bdev)
2654                 return 0;
2655         attached_disk = pd->bdev->bd_disk;
2656         if (!attached_disk || !attached_disk->fops->check_events)
2657                 return 0;
2658         return attached_disk->fops->check_events(attached_disk, clearing);
2659 }
2660
2661 static char *pkt_devnode(struct gendisk *disk, umode_t *mode)
2662 {
2663         return kasprintf(GFP_KERNEL, "pktcdvd/%s", disk->disk_name);
2664 }
2665
2666 static const struct block_device_operations pktcdvd_ops = {
2667         .owner =                THIS_MODULE,
2668         .submit_bio =           pkt_submit_bio,
2669         .open =                 pkt_open,
2670         .release =              pkt_close,
2671         .ioctl =                pkt_ioctl,
2672         .compat_ioctl =         blkdev_compat_ptr_ioctl,
2673         .check_events =         pkt_check_events,
2674         .devnode =              pkt_devnode,
2675 };
2676
2677 /*
2678  * Set up mapping from pktcdvd device to CD-ROM device.
2679  */
2680 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2681 {
2682         int idx;
2683         int ret = -ENOMEM;
2684         struct pktcdvd_device *pd;
2685         struct gendisk *disk;
2686
2687         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2688
2689         for (idx = 0; idx < MAX_WRITERS; idx++)
2690                 if (!pkt_devs[idx])
2691                         break;
2692         if (idx == MAX_WRITERS) {
2693                 pr_err("max %d writers supported\n", MAX_WRITERS);
2694                 ret = -EBUSY;
2695                 goto out_mutex;
2696         }
2697
2698         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2699         if (!pd)
2700                 goto out_mutex;
2701
2702         ret = mempool_init_kmalloc_pool(&pd->rb_pool, PKT_RB_POOL_SIZE,
2703                                         sizeof(struct pkt_rb_node));
2704         if (ret)
2705                 goto out_mem;
2706
2707         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2708         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2709         spin_lock_init(&pd->cdrw.active_list_lock);
2710
2711         spin_lock_init(&pd->lock);
2712         spin_lock_init(&pd->iosched.lock);
2713         bio_list_init(&pd->iosched.read_queue);
2714         bio_list_init(&pd->iosched.write_queue);
2715         sprintf(pd->name, DRIVER_NAME"%d", idx);
2716         init_waitqueue_head(&pd->wqueue);
2717         pd->bio_queue = RB_ROOT;
2718
2719         pd->write_congestion_on  = write_congestion_on;
2720         pd->write_congestion_off = write_congestion_off;
2721
2722         ret = -ENOMEM;
2723         disk = blk_alloc_disk(NUMA_NO_NODE);
2724         if (!disk)
2725                 goto out_mem;
2726         pd->disk = disk;
2727         disk->major = pktdev_major;
2728         disk->first_minor = idx;
2729         disk->minors = 1;
2730         disk->fops = &pktcdvd_ops;
2731         disk->flags = GENHD_FL_REMOVABLE | GENHD_FL_NO_PART;
2732         strcpy(disk->disk_name, pd->name);
2733         disk->private_data = pd;
2734
2735         pd->pkt_dev = MKDEV(pktdev_major, idx);
2736         ret = pkt_new_dev(pd, dev);
2737         if (ret)
2738                 goto out_mem2;
2739
2740         /* inherit events of the host device */
2741         disk->events = pd->bdev->bd_disk->events;
2742
2743         ret = add_disk(disk);
2744         if (ret)
2745                 goto out_mem2;
2746
2747         pkt_sysfs_dev_new(pd);
2748         pkt_debugfs_dev_new(pd);
2749
2750         pkt_devs[idx] = pd;
2751         if (pkt_dev)
2752                 *pkt_dev = pd->pkt_dev;
2753
2754         mutex_unlock(&ctl_mutex);
2755         return 0;
2756
2757 out_mem2:
2758         blk_cleanup_disk(disk);
2759 out_mem:
2760         mempool_exit(&pd->rb_pool);
2761         kfree(pd);
2762 out_mutex:
2763         mutex_unlock(&ctl_mutex);
2764         pr_err("setup of pktcdvd device failed\n");
2765         return ret;
2766 }
2767
2768 /*
2769  * Tear down mapping from pktcdvd device to CD-ROM device.
2770  */
2771 static int pkt_remove_dev(dev_t pkt_dev)
2772 {
2773         struct pktcdvd_device *pd;
2774         int idx;
2775         int ret = 0;
2776
2777         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2778
2779         for (idx = 0; idx < MAX_WRITERS; idx++) {
2780                 pd = pkt_devs[idx];
2781                 if (pd && (pd->pkt_dev == pkt_dev))
2782                         break;
2783         }
2784         if (idx == MAX_WRITERS) {
2785                 pr_debug("dev not setup\n");
2786                 ret = -ENXIO;
2787                 goto out;
2788         }
2789
2790         if (pd->refcnt > 0) {
2791                 ret = -EBUSY;
2792                 goto out;
2793         }
2794         if (!IS_ERR(pd->cdrw.thread))
2795                 kthread_stop(pd->cdrw.thread);
2796
2797         pkt_devs[idx] = NULL;
2798
2799         pkt_debugfs_dev_remove(pd);
2800         pkt_sysfs_dev_remove(pd);
2801
2802         blkdev_put(pd->bdev, FMODE_READ | FMODE_NDELAY);
2803
2804         remove_proc_entry(pd->name, pkt_proc);
2805         pkt_dbg(1, pd, "writer unmapped\n");
2806
2807         del_gendisk(pd->disk);
2808         blk_cleanup_disk(pd->disk);
2809
2810         mempool_exit(&pd->rb_pool);
2811         kfree(pd);
2812
2813         /* This is safe: open() is still holding a reference. */
2814         module_put(THIS_MODULE);
2815
2816 out:
2817         mutex_unlock(&ctl_mutex);
2818         return ret;
2819 }
2820
2821 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2822 {
2823         struct pktcdvd_device *pd;
2824
2825         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2826
2827         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2828         if (pd) {
2829                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2830                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2831         } else {
2832                 ctrl_cmd->dev = 0;
2833                 ctrl_cmd->pkt_dev = 0;
2834         }
2835         ctrl_cmd->num_devices = MAX_WRITERS;
2836
2837         mutex_unlock(&ctl_mutex);
2838 }
2839
2840 static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2841 {
2842         void __user *argp = (void __user *)arg;
2843         struct pkt_ctrl_command ctrl_cmd;
2844         int ret = 0;
2845         dev_t pkt_dev = 0;
2846
2847         if (cmd != PACKET_CTRL_CMD)
2848                 return -ENOTTY;
2849
2850         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2851                 return -EFAULT;
2852
2853         switch (ctrl_cmd.command) {
2854         case PKT_CTRL_CMD_SETUP:
2855                 if (!capable(CAP_SYS_ADMIN))
2856                         return -EPERM;
2857                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2858                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2859                 break;
2860         case PKT_CTRL_CMD_TEARDOWN:
2861                 if (!capable(CAP_SYS_ADMIN))
2862                         return -EPERM;
2863                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2864                 break;
2865         case PKT_CTRL_CMD_STATUS:
2866                 pkt_get_status(&ctrl_cmd);
2867                 break;
2868         default:
2869                 return -ENOTTY;
2870         }
2871
2872         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2873                 return -EFAULT;
2874         return ret;
2875 }
2876
2877 #ifdef CONFIG_COMPAT
2878 static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2879 {
2880         return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2881 }
2882 #endif
2883
2884 static const struct file_operations pkt_ctl_fops = {
2885         .open           = nonseekable_open,
2886         .unlocked_ioctl = pkt_ctl_ioctl,
2887 #ifdef CONFIG_COMPAT
2888         .compat_ioctl   = pkt_ctl_compat_ioctl,
2889 #endif
2890         .owner          = THIS_MODULE,
2891         .llseek         = no_llseek,
2892 };
2893
2894 static struct miscdevice pkt_misc = {
2895         .minor          = MISC_DYNAMIC_MINOR,
2896         .name           = DRIVER_NAME,
2897         .nodename       = "pktcdvd/control",
2898         .fops           = &pkt_ctl_fops
2899 };
2900
2901 static int __init pkt_init(void)
2902 {
2903         int ret;
2904
2905         mutex_init(&ctl_mutex);
2906
2907         ret = mempool_init_kmalloc_pool(&psd_pool, PSD_POOL_SIZE,
2908                                     sizeof(struct packet_stacked_data));
2909         if (ret)
2910                 return ret;
2911         ret = bioset_init(&pkt_bio_set, BIO_POOL_SIZE, 0, 0);
2912         if (ret) {
2913                 mempool_exit(&psd_pool);
2914                 return ret;
2915         }
2916
2917         ret = register_blkdev(pktdev_major, DRIVER_NAME);
2918         if (ret < 0) {
2919                 pr_err("unable to register block device\n");
2920                 goto out2;
2921         }
2922         if (!pktdev_major)
2923                 pktdev_major = ret;
2924
2925         ret = pkt_sysfs_init();
2926         if (ret)
2927                 goto out;
2928
2929         pkt_debugfs_init();
2930
2931         ret = misc_register(&pkt_misc);
2932         if (ret) {
2933                 pr_err("unable to register misc device\n");
2934                 goto out_misc;
2935         }
2936
2937         pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
2938
2939         return 0;
2940
2941 out_misc:
2942         pkt_debugfs_cleanup();
2943         pkt_sysfs_cleanup();
2944 out:
2945         unregister_blkdev(pktdev_major, DRIVER_NAME);
2946 out2:
2947         mempool_exit(&psd_pool);
2948         bioset_exit(&pkt_bio_set);
2949         return ret;
2950 }
2951
2952 static void __exit pkt_exit(void)
2953 {
2954         remove_proc_entry("driver/"DRIVER_NAME, NULL);
2955         misc_deregister(&pkt_misc);
2956
2957         pkt_debugfs_cleanup();
2958         pkt_sysfs_cleanup();
2959
2960         unregister_blkdev(pktdev_major, DRIVER_NAME);
2961         mempool_exit(&psd_pool);
2962         bioset_exit(&pkt_bio_set);
2963 }
2964
2965 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
2966 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
2967 MODULE_LICENSE("GPL");
2968
2969 module_init(pkt_init);
2970 module_exit(pkt_exit);