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 = blk_get_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(pd->bdev->bd_disk, rq, 0);
 726         if (scsi_req(rq)->result)
 727                 ret = -EIO;
 728 out:
 729         blk_put_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         int wakeup;
1111
1112         atomic_set(&pd->scan_queue, 0);
1113
1114         if (list_empty(&pd->cdrw.pkt_free_list)) {
1115                 pkt_dbg(2, pd, "no pkt\n");
1116                 return 0;
1117         }
1118
1119         /*
1120          * Try to find a zone we are not already working on.
1121          */
1122         spin_lock(&pd->lock);
1123         first_node = pkt_rbtree_find(pd, pd->current_sector);
1124         if (!first_node) {
1125                 n = rb_first(&pd->bio_queue);
1126                 if (n)
1127                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1128         }
1129         node = first_node;
1130         while (node) {
1131                 bio = node->bio;
1132                 zone = get_zone(bio->bi_iter.bi_sector, pd);
1133                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1134                         if (p->sector == zone) {
1135                                 bio = NULL;
1136                                 goto try_next_bio;
1137                         }
1138                 }
1139                 break;
1140 try_next_bio:
1141                 node = pkt_rbtree_next(node);
1142                 if (!node) {
1143                         n = rb_first(&pd->bio_queue);
1144                         if (n)
1145                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1146                 }
1147                 if (node == first_node)
1148                         node = NULL;
1149         }
1150         spin_unlock(&pd->lock);
1151         if (!bio) {
1152                 pkt_dbg(2, pd, "no bio\n");
1153                 return 0;
1154         }
1155
1156         pkt = pkt_get_packet_data(pd, zone);
1157
1158         pd->current_sector = zone + pd->settings.size;
1159         pkt->sector = zone;
1160         BUG_ON(pkt->frames != pd->settings.size >> 2);
1161         pkt->write_size = 0;
1162
1163         /*
1164          * Scan work queue for bios in the same zone and link them
1165          * to this packet.
1166          */
1167         spin_lock(&pd->lock);
1168         pkt_dbg(2, pd, "looking for zone %llx\n", (unsigned long long)zone);
1169         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1170                 bio = node->bio;
1171                 pkt_dbg(2, pd, "found zone=%llx\n", (unsigned long long)
1172                         get_zone(bio->bi_iter.bi_sector, pd));
1173                 if (get_zone(bio->bi_iter.bi_sector, pd) != zone)
1174                         break;
1175                 pkt_rbtree_erase(pd, node);
1176                 spin_lock(&pkt->lock);
1177                 bio_list_add(&pkt->orig_bios, bio);
1178                 pkt->write_size += bio->bi_iter.bi_size / CD_FRAMESIZE;
1179                 spin_unlock(&pkt->lock);
1180         }
1181         /* check write congestion marks, and if bio_queue_size is
1182            below, wake up any waiters */
1183         wakeup = (pd->write_congestion_on > 0
1184                         && pd->bio_queue_size <= pd->write_congestion_off);
1185         spin_unlock(&pd->lock);
1186         if (wakeup)
1187                 clear_bdi_congested(pd->disk->bdi, BLK_RW_ASYNC);
1188
1189         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1190         pkt_set_state(pkt, PACKET_WAITING_STATE);
1191         atomic_set(&pkt->run_sm, 1);
1192
1193         spin_lock(&pd->cdrw.active_list_lock);
1194         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1195         spin_unlock(&pd->cdrw.active_list_lock);
1196
1197         return 1;
1198 }
1199
1200 /**
1201  * bio_list_copy_data - copy contents of data buffers from one chain of bios to
1202  * another
1203  * @src: source bio list
1204  * @dst: destination bio list
1205  *
1206  * Stops when it reaches the end of either the @src list or @dst list - that is,
1207  * copies min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of
1208  * bios).
1209  */
1210 static void bio_list_copy_data(struct bio *dst, struct bio *src)
1211 {
1212         struct bvec_iter src_iter = src->bi_iter;
1213         struct bvec_iter dst_iter = dst->bi_iter;
1214
1215         while (1) {
1216                 if (!src_iter.bi_size) {
1217                         src = src->bi_next;
1218                         if (!src)
1219                                 break;
1220
1221                         src_iter = src->bi_iter;
1222                 }
1223
1224                 if (!dst_iter.bi_size) {
1225                         dst = dst->bi_next;
1226                         if (!dst)
1227                                 break;
1228
1229                         dst_iter = dst->bi_iter;
1230                 }
1231
1232                 bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
1233         }
1234 }
1235
1236 /*
1237  * Assemble a bio to write one packet and queue the bio for processing
1238  * by the underlying block device.
1239  */
1240 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1241 {
1242         int f;
1243
1244         bio_reset(pkt->w_bio);
1245         pkt->w_bio->bi_iter.bi_sector = pkt->sector;
1246         bio_set_dev(pkt->w_bio, pd->bdev);
1247         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1248         pkt->w_bio->bi_private = pkt;
1249
1250         /* XXX: locking? */
1251         for (f = 0; f < pkt->frames; f++) {
1252                 struct page *page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1253                 unsigned offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1254
1255                 if (!bio_add_page(pkt->w_bio, page, CD_FRAMESIZE, offset))
1256                         BUG();
1257         }
1258         pkt_dbg(2, pd, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
1259
1260         /*
1261          * Fill-in bvec with data from orig_bios.
1262          */
1263         spin_lock(&pkt->lock);
1264         bio_list_copy_data(pkt->w_bio, pkt->orig_bios.head);
1265
1266         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1267         spin_unlock(&pkt->lock);
1268
1269         pkt_dbg(2, pd, "Writing %d frames for zone %llx\n",
1270                 pkt->write_size, (unsigned long long)pkt->sector);
1271
1272         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames))
1273                 pkt->cache_valid = 1;
1274         else
1275                 pkt->cache_valid = 0;
1276
1277         /* Start the write request */
1278         atomic_set(&pkt->io_wait, 1);
1279         bio_set_op_attrs(pkt->w_bio, REQ_OP_WRITE, 0);
1280         pkt_queue_bio(pd, pkt->w_bio);
1281 }
1282
1283 static void pkt_finish_packet(struct packet_data *pkt, blk_status_t status)
1284 {
1285         struct bio *bio;
1286
1287         if (status)
1288                 pkt->cache_valid = 0;
1289
1290         /* Finish all bios corresponding to this packet */
1291         while ((bio = bio_list_pop(&pkt->orig_bios))) {
1292                 bio->bi_status = status;
1293                 bio_endio(bio);
1294         }
1295 }
1296
1297 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1298 {
1299         pkt_dbg(2, pd, "pkt %d\n", pkt->id);
1300
1301         for (;;) {
1302                 switch (pkt->state) {
1303                 case PACKET_WAITING_STATE:
1304                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1305                                 return;
1306
1307                         pkt->sleep_time = 0;
1308                         pkt_gather_data(pd, pkt);
1309                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1310                         break;
1311
1312                 case PACKET_READ_WAIT_STATE:
1313                         if (atomic_read(&pkt->io_wait) > 0)
1314                                 return;
1315
1316                         if (atomic_read(&pkt->io_errors) > 0) {
1317                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1318                         } else {
1319                                 pkt_start_write(pd, pkt);
1320                         }
1321                         break;
1322
1323                 case PACKET_WRITE_WAIT_STATE:
1324                         if (atomic_read(&pkt->io_wait) > 0)
1325                                 return;
1326
1327                         if (!pkt->w_bio->bi_status) {
1328                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1329                         } else {
1330                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1331                         }
1332                         break;
1333
1334                 case PACKET_RECOVERY_STATE:
1335                         pkt_dbg(2, pd, "No recovery possible\n");
1336                         pkt_set_state(pkt, PACKET_FINISHED_STATE);
1337                         break;
1338
1339                 case PACKET_FINISHED_STATE:
1340                         pkt_finish_packet(pkt, pkt->w_bio->bi_status);
1341                         return;
1342
1343                 default:
1344                         BUG();
1345                         break;
1346                 }
1347         }
1348 }
1349
1350 static void pkt_handle_packets(struct pktcdvd_device *pd)
1351 {
1352         struct packet_data *pkt, *next;
1353
1354         /*
1355          * Run state machine for active packets
1356          */
1357         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1358                 if (atomic_read(&pkt->run_sm) > 0) {
1359                         atomic_set(&pkt->run_sm, 0);
1360                         pkt_run_state_machine(pd, pkt);
1361                 }
1362         }
1363
1364         /*
1365          * Move no longer active packets to the free list
1366          */
1367         spin_lock(&pd->cdrw.active_list_lock);
1368         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1369                 if (pkt->state == PACKET_FINISHED_STATE) {
1370                         list_del(&pkt->list);
1371                         pkt_put_packet_data(pd, pkt);
1372                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1373                         atomic_set(&pd->scan_queue, 1);
1374                 }
1375         }
1376         spin_unlock(&pd->cdrw.active_list_lock);
1377 }
1378
1379 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1380 {
1381         struct packet_data *pkt;
1382         int i;
1383
1384         for (i = 0; i < PACKET_NUM_STATES; i++)
1385                 states[i] = 0;
1386
1387         spin_lock(&pd->cdrw.active_list_lock);
1388         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1389                 states[pkt->state]++;
1390         }
1391         spin_unlock(&pd->cdrw.active_list_lock);
1392 }
1393
1394 /*
1395  * kcdrwd is woken up when writes have been queued for one of our
1396  * registered devices
1397  */
1398 static int kcdrwd(void *foobar)
1399 {
1400         struct pktcdvd_device *pd = foobar;
1401         struct packet_data *pkt;
1402         long min_sleep_time, residue;
1403
1404         set_user_nice(current, MIN_NICE);
1405         set_freezable();
1406
1407         for (;;) {
1408                 DECLARE_WAITQUEUE(wait, current);
1409
1410                 /*
1411                  * Wait until there is something to do
1412                  */
1413                 add_wait_queue(&pd->wqueue, &wait);
1414                 for (;;) {
1415                         set_current_state(TASK_INTERRUPTIBLE);
1416
1417                         /* Check if we need to run pkt_handle_queue */
1418                         if (atomic_read(&pd->scan_queue) > 0)
1419                                 goto work_to_do;
1420
1421                         /* Check if we need to run the state machine for some packet */
1422                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1423                                 if (atomic_read(&pkt->run_sm) > 0)
1424                                         goto work_to_do;
1425                         }
1426
1427                         /* Check if we need to process the iosched queues */
1428                         if (atomic_read(&pd->iosched.attention) != 0)
1429                                 goto work_to_do;
1430
1431                         /* Otherwise, go to sleep */
1432                         if (PACKET_DEBUG > 1) {
1433                                 int states[PACKET_NUM_STATES];
1434                                 pkt_count_states(pd, states);
1435                                 pkt_dbg(2, pd, "i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1436                                         states[0], states[1], states[2],
1437                                         states[3], states[4], states[5]);
1438                         }
1439
1440                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1441                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1442                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1443                                         min_sleep_time = pkt->sleep_time;
1444                         }
1445
1446                         pkt_dbg(2, pd, "sleeping\n");
1447                         residue = schedule_timeout(min_sleep_time);
1448                         pkt_dbg(2, pd, "wake up\n");
1449
1450                         /* make swsusp happy with our thread */
1451                         try_to_freeze();
1452
1453                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1454                                 if (!pkt->sleep_time)
1455                                         continue;
1456                                 pkt->sleep_time -= min_sleep_time - residue;
1457                                 if (pkt->sleep_time <= 0) {
1458                                         pkt->sleep_time = 0;
1459                                         atomic_inc(&pkt->run_sm);
1460                                 }
1461                         }
1462
1463                         if (kthread_should_stop())
1464                                 break;
1465                 }
1466 work_to_do:
1467                 set_current_state(TASK_RUNNING);
1468                 remove_wait_queue(&pd->wqueue, &wait);
1469
1470                 if (kthread_should_stop())
1471                         break;
1472
1473                 /*
1474                  * if pkt_handle_queue returns true, we can queue
1475                  * another request.
1476                  */
1477                 while (pkt_handle_queue(pd))
1478                         ;
1479
1480                 /*
1481                  * Handle packet state machine
1482                  */
1483                 pkt_handle_packets(pd);
1484
1485                 /*
1486                  * Handle iosched queues
1487                  */
1488                 pkt_iosched_process_queue(pd);
1489         }
1490
1491         return 0;
1492 }
1493
1494 static void pkt_print_settings(struct pktcdvd_device *pd)
1495 {
1496         pkt_info(pd, "%s packets, %u blocks, Mode-%c disc\n",
1497                  pd->settings.fp ? "Fixed" : "Variable",
1498                  pd->settings.size >> 2,
1499                  pd->settings.block_mode == 8 ? '1' : '2');
1500 }
1501
1502 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1503 {
1504         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1505
1506         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1507         cgc->cmd[2] = page_code | (page_control << 6);
1508         cgc->cmd[7] = cgc->buflen >> 8;
1509         cgc->cmd[8] = cgc->buflen & 0xff;
1510         cgc->data_direction = CGC_DATA_READ;
1511         return pkt_generic_packet(pd, cgc);
1512 }
1513
1514 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1515 {
1516         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1517         memset(cgc->buffer, 0, 2);
1518         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1519         cgc->cmd[1] = 0x10;             /* PF */
1520         cgc->cmd[7] = cgc->buflen >> 8;
1521         cgc->cmd[8] = cgc->buflen & 0xff;
1522         cgc->data_direction = CGC_DATA_WRITE;
1523         return pkt_generic_packet(pd, cgc);
1524 }
1525
1526 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1527 {
1528         struct packet_command cgc;
1529         int ret;
1530
1531         /* set up command and get the disc info */
1532         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1533         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1534         cgc.cmd[8] = cgc.buflen = 2;
1535         cgc.quiet = 1;
1536
1537         ret = pkt_generic_packet(pd, &cgc);
1538         if (ret)
1539                 return ret;
1540
1541         /* not all drives have the same disc_info length, so requeue
1542          * packet with the length the drive tells us it can supply
1543          */
1544         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1545                      sizeof(di->disc_information_length);
1546
1547         if (cgc.buflen > sizeof(disc_information))
1548                 cgc.buflen = sizeof(disc_information);
1549
1550         cgc.cmd[8] = cgc.buflen;
1551         return pkt_generic_packet(pd, &cgc);
1552 }
1553
1554 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1555 {
1556         struct packet_command cgc;
1557         int ret;
1558
1559         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1560         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1561         cgc.cmd[1] = type & 3;
1562         cgc.cmd[4] = (track & 0xff00) >> 8;
1563         cgc.cmd[5] = track & 0xff;
1564         cgc.cmd[8] = 8;
1565         cgc.quiet = 1;
1566
1567         ret = pkt_generic_packet(pd, &cgc);
1568         if (ret)
1569                 return ret;
1570
1571         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1572                      sizeof(ti->track_information_length);
1573
1574         if (cgc.buflen > sizeof(track_information))
1575                 cgc.buflen = sizeof(track_information);
1576
1577         cgc.cmd[8] = cgc.buflen;
1578         return pkt_generic_packet(pd, &cgc);
1579 }
1580
1581 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1582                                                 long *last_written)
1583 {
1584         disc_information di;
1585         track_information ti;
1586         __u32 last_track;
1587         int ret;
1588
1589         ret = pkt_get_disc_info(pd, &di);
1590         if (ret)
1591                 return ret;
1592
1593         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1594         ret = pkt_get_track_info(pd, last_track, 1, &ti);
1595         if (ret)
1596                 return ret;
1597
1598         /* if this track is blank, try the previous. */
1599         if (ti.blank) {
1600                 last_track--;
1601                 ret = pkt_get_track_info(pd, last_track, 1, &ti);
1602                 if (ret)
1603                         return ret;
1604         }
1605
1606         /* if last recorded field is valid, return it. */
1607         if (ti.lra_v) {
1608                 *last_written = be32_to_cpu(ti.last_rec_address);
1609         } else {
1610                 /* make it up instead */
1611                 *last_written = be32_to_cpu(ti.track_start) +
1612                                 be32_to_cpu(ti.track_size);
1613                 if (ti.free_blocks)
1614                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1615         }
1616         return 0;
1617 }
1618
1619 /*
1620  * write mode select package based on pd->settings
1621  */
1622 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1623 {
1624         struct packet_command cgc;
1625         struct scsi_sense_hdr sshdr;
1626         write_param_page *wp;
1627         char buffer[128];
1628         int ret, size;
1629
1630         /* doesn't apply to DVD+RW or DVD-RAM */
1631         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1632                 return 0;
1633
1634         memset(buffer, 0, sizeof(buffer));
1635         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1636         cgc.sshdr = &sshdr;
1637         ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1638         if (ret) {
1639                 pkt_dump_sense(pd, &cgc);
1640                 return ret;
1641         }
1642
1643         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1644         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1645         if (size > sizeof(buffer))
1646                 size = sizeof(buffer);
1647
1648         /*
1649          * now get it all
1650          */
1651         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1652         cgc.sshdr = &sshdr;
1653         ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1654         if (ret) {
1655                 pkt_dump_sense(pd, &cgc);
1656                 return ret;
1657         }
1658
1659         /*
1660          * write page is offset header + block descriptor length
1661          */
1662         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1663
1664         wp->fp = pd->settings.fp;
1665         wp->track_mode = pd->settings.track_mode;
1666         wp->write_type = pd->settings.write_type;
1667         wp->data_block_type = pd->settings.block_mode;
1668
1669         wp->multi_session = 0;
1670
1671 #ifdef PACKET_USE_LS
1672         wp->link_size = 7;
1673         wp->ls_v = 1;
1674 #endif
1675
1676         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1677                 wp->session_format = 0;
1678                 wp->subhdr2 = 0x20;
1679         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1680                 wp->session_format = 0x20;
1681                 wp->subhdr2 = 8;
1682 #if 0
1683                 wp->mcn[0] = 0x80;
1684                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1685 #endif
1686         } else {
1687                 /*
1688                  * paranoia
1689                  */
1690                 pkt_err(pd, "write mode wrong %d\n", wp->data_block_type);
1691                 return 1;
1692         }
1693         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1694
1695         cgc.buflen = cgc.cmd[8] = size;
1696         ret = pkt_mode_select(pd, &cgc);
1697         if (ret) {
1698                 pkt_dump_sense(pd, &cgc);
1699                 return ret;
1700         }
1701
1702         pkt_print_settings(pd);
1703         return 0;
1704 }
1705
1706 /*
1707  * 1 -- we can write to this track, 0 -- we can't
1708  */
1709 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1710 {
1711         switch (pd->mmc3_profile) {
1712                 case 0x1a: /* DVD+RW */
1713                 case 0x12: /* DVD-RAM */
1714                         /* The track is always writable on DVD+RW/DVD-RAM */
1715                         return 1;
1716                 default:
1717                         break;
1718         }
1719
1720         if (!ti->packet || !ti->fp)
1721                 return 0;
1722
1723         /*
1724          * "good" settings as per Mt Fuji.
1725          */
1726         if (ti->rt == 0 && ti->blank == 0)
1727                 return 1;
1728
1729         if (ti->rt == 0 && ti->blank == 1)
1730                 return 1;
1731
1732         if (ti->rt == 1 && ti->blank == 0)
1733                 return 1;
1734
1735         pkt_err(pd, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1736         return 0;
1737 }
1738
1739 /*
1740  * 1 -- we can write to this disc, 0 -- we can't
1741  */
1742 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1743 {
1744         switch (pd->mmc3_profile) {
1745                 case 0x0a: /* CD-RW */
1746                 case 0xffff: /* MMC3 not supported */
1747                         break;
1748                 case 0x1a: /* DVD+RW */
1749                 case 0x13: /* DVD-RW */
1750                 case 0x12: /* DVD-RAM */
1751                         return 1;
1752                 default:
1753                         pkt_dbg(2, pd, "Wrong disc profile (%x)\n",
1754                                 pd->mmc3_profile);
1755                         return 0;
1756         }
1757
1758         /*
1759          * for disc type 0xff we should probably reserve a new track.
1760          * but i'm not sure, should we leave this to user apps? probably.
1761          */
1762         if (di->disc_type == 0xff) {
1763                 pkt_notice(pd, "unknown disc - no track?\n");
1764                 return 0;
1765         }
1766
1767         if (di->disc_type != 0x20 && di->disc_type != 0) {
1768                 pkt_err(pd, "wrong disc type (%x)\n", di->disc_type);
1769                 return 0;
1770         }
1771
1772         if (di->erasable == 0) {
1773                 pkt_notice(pd, "disc not erasable\n");
1774                 return 0;
1775         }
1776
1777         if (di->border_status == PACKET_SESSION_RESERVED) {
1778                 pkt_err(pd, "can't write to last track (reserved)\n");
1779                 return 0;
1780         }
1781
1782         return 1;
1783 }
1784
1785 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1786 {
1787         struct packet_command cgc;
1788         unsigned char buf[12];
1789         disc_information di;
1790         track_information ti;
1791         int ret, track;
1792
1793         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1794         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1795         cgc.cmd[8] = 8;
1796         ret = pkt_generic_packet(pd, &cgc);
1797         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1798
1799         memset(&di, 0, sizeof(disc_information));
1800         memset(&ti, 0, sizeof(track_information));
1801
1802         ret = pkt_get_disc_info(pd, &di);
1803         if (ret) {
1804                 pkt_err(pd, "failed get_disc\n");
1805                 return ret;
1806         }
1807
1808         if (!pkt_writable_disc(pd, &di))
1809                 return -EROFS;
1810
1811         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1812
1813         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1814         ret = pkt_get_track_info(pd, track, 1, &ti);
1815         if (ret) {
1816                 pkt_err(pd, "failed get_track\n");
1817                 return ret;
1818         }
1819
1820         if (!pkt_writable_track(pd, &ti)) {
1821                 pkt_err(pd, "can't write to this track\n");
1822                 return -EROFS;
1823         }
1824
1825         /*
1826          * we keep packet size in 512 byte units, makes it easier to
1827          * deal with request calculations.
1828          */
1829         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1830         if (pd->settings.size == 0) {
1831                 pkt_notice(pd, "detected zero packet size!\n");
1832                 return -ENXIO;
1833         }
1834         if (pd->settings.size > PACKET_MAX_SECTORS) {
1835                 pkt_err(pd, "packet size is too big\n");
1836                 return -EROFS;
1837         }
1838         pd->settings.fp = ti.fp;
1839         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1840
1841         if (ti.nwa_v) {
1842                 pd->nwa = be32_to_cpu(ti.next_writable);
1843                 set_bit(PACKET_NWA_VALID, &pd->flags);
1844         }
1845
1846         /*
1847          * in theory we could use lra on -RW media as well and just zero
1848          * blocks that haven't been written yet, but in practice that
1849          * is just a no-go. we'll use that for -R, naturally.
1850          */
1851         if (ti.lra_v) {
1852                 pd->lra = be32_to_cpu(ti.last_rec_address);
1853                 set_bit(PACKET_LRA_VALID, &pd->flags);
1854         } else {
1855                 pd->lra = 0xffffffff;
1856                 set_bit(PACKET_LRA_VALID, &pd->flags);
1857         }
1858
1859         /*
1860          * fine for now
1861          */
1862         pd->settings.link_loss = 7;
1863         pd->settings.write_type = 0;    /* packet */
1864         pd->settings.track_mode = ti.track_mode;
1865
1866         /*
1867          * mode1 or mode2 disc
1868          */
1869         switch (ti.data_mode) {
1870                 case PACKET_MODE1:
1871                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
1872                         break;
1873                 case PACKET_MODE2:
1874                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
1875                         break;
1876                 default:
1877                         pkt_err(pd, "unknown data mode\n");
1878                         return -EROFS;
1879         }
1880         return 0;
1881 }
1882
1883 /*
1884  * enable/disable write caching on drive
1885  */
1886 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
1887                                                 int set)
1888 {
1889         struct packet_command cgc;
1890         struct scsi_sense_hdr sshdr;
1891         unsigned char buf[64];
1892         int ret;
1893
1894         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1895         cgc.sshdr = &sshdr;
1896         cgc.buflen = pd->mode_offset + 12;
1897
1898         /*
1899          * caching mode page might not be there, so quiet this command
1900          */
1901         cgc.quiet = 1;
1902
1903         ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0);
1904         if (ret)
1905                 return ret;
1906
1907         buf[pd->mode_offset + 10] |= (!!set << 2);
1908
1909         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
1910         ret = pkt_mode_select(pd, &cgc);
1911         if (ret) {
1912                 pkt_err(pd, "write caching control failed\n");
1913                 pkt_dump_sense(pd, &cgc);
1914         } else if (!ret && set)
1915                 pkt_notice(pd, "enabled write caching\n");
1916         return ret;
1917 }
1918
1919 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1920 {
1921         struct packet_command cgc;
1922
1923         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1924         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1925         cgc.cmd[4] = lockflag ? 1 : 0;
1926         return pkt_generic_packet(pd, &cgc);
1927 }
1928
1929 /*
1930  * Returns drive maximum write speed
1931  */
1932 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1933                                                 unsigned *write_speed)
1934 {
1935         struct packet_command cgc;
1936         struct scsi_sense_hdr sshdr;
1937         unsigned char buf[256+18];
1938         unsigned char *cap_buf;
1939         int ret, offset;
1940
1941         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1942         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1943         cgc.sshdr = &sshdr;
1944
1945         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1946         if (ret) {
1947                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
1948                              sizeof(struct mode_page_header);
1949                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1950                 if (ret) {
1951                         pkt_dump_sense(pd, &cgc);
1952                         return ret;
1953                 }
1954         }
1955
1956         offset = 20;                        /* Obsoleted field, used by older drives */
1957         if (cap_buf[1] >= 28)
1958                 offset = 28;                /* Current write speed selected */
1959         if (cap_buf[1] >= 30) {
1960                 /* If the drive reports at least one "Logical Unit Write
1961                  * Speed Performance Descriptor Block", use the information
1962                  * in the first block. (contains the highest speed)
1963                  */
1964                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
1965                 if (num_spdb > 0)
1966                         offset = 34;
1967         }
1968
1969         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
1970         return 0;
1971 }
1972
1973 /* These tables from cdrecord - I don't have orange book */
1974 /* standard speed CD-RW (1-4x) */
1975 static char clv_to_speed[16] = {
1976         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1977            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1978 };
1979 /* high speed CD-RW (-10x) */
1980 static char hs_clv_to_speed[16] = {
1981         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1982            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1983 };
1984 /* ultra high speed CD-RW */
1985 static char us_clv_to_speed[16] = {
1986         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1987            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
1988 };
1989
1990 /*
1991  * reads the maximum media speed from ATIP
1992  */
1993 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
1994                                                 unsigned *speed)
1995 {
1996         struct packet_command cgc;
1997         struct scsi_sense_hdr sshdr;
1998         unsigned char buf[64];
1999         unsigned int size, st, sp;
2000         int ret;
2001
2002         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2003         cgc.sshdr = &sshdr;
2004         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2005         cgc.cmd[1] = 2;
2006         cgc.cmd[2] = 4; /* READ ATIP */
2007         cgc.cmd[8] = 2;
2008         ret = pkt_generic_packet(pd, &cgc);
2009         if (ret) {
2010                 pkt_dump_sense(pd, &cgc);
2011                 return ret;
2012         }
2013         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2014         if (size > sizeof(buf))
2015                 size = sizeof(buf);
2016
2017         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2018         cgc.sshdr = &sshdr;
2019         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2020         cgc.cmd[1] = 2;
2021         cgc.cmd[2] = 4;
2022         cgc.cmd[8] = size;
2023         ret = pkt_generic_packet(pd, &cgc);
2024         if (ret) {
2025                 pkt_dump_sense(pd, &cgc);
2026                 return ret;
2027         }
2028
2029         if (!(buf[6] & 0x40)) {
2030                 pkt_notice(pd, "disc type is not CD-RW\n");
2031                 return 1;
2032         }
2033         if (!(buf[6] & 0x4)) {
2034                 pkt_notice(pd, "A1 values on media are not valid, maybe not CDRW?\n");
2035                 return 1;
2036         }
2037
2038         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2039
2040         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2041
2042         /* Info from cdrecord */
2043         switch (st) {
2044                 case 0: /* standard speed */
2045                         *speed = clv_to_speed[sp];
2046                         break;
2047                 case 1: /* high speed */
2048                         *speed = hs_clv_to_speed[sp];
2049                         break;
2050                 case 2: /* ultra high speed */
2051                         *speed = us_clv_to_speed[sp];
2052                         break;
2053                 default:
2054                         pkt_notice(pd, "unknown disc sub-type %d\n", st);
2055                         return 1;
2056         }
2057         if (*speed) {
2058                 pkt_info(pd, "maximum media speed: %d\n", *speed);
2059                 return 0;
2060         } else {
2061                 pkt_notice(pd, "unknown speed %d for sub-type %d\n", sp, st);
2062                 return 1;
2063         }
2064 }
2065
2066 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2067 {
2068         struct packet_command cgc;
2069         struct scsi_sense_hdr sshdr;
2070         int ret;
2071
2072         pkt_dbg(2, pd, "Performing OPC\n");
2073
2074         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2075         cgc.sshdr = &sshdr;
2076         cgc.timeout = 60*HZ;
2077         cgc.cmd[0] = GPCMD_SEND_OPC;
2078         cgc.cmd[1] = 1;
2079         ret = pkt_generic_packet(pd, &cgc);
2080         if (ret)
2081                 pkt_dump_sense(pd, &cgc);
2082         return ret;
2083 }
2084
2085 static int pkt_open_write(struct pktcdvd_device *pd)
2086 {
2087         int ret;
2088         unsigned int write_speed, media_write_speed, read_speed;
2089
2090         ret = pkt_probe_settings(pd);
2091         if (ret) {
2092                 pkt_dbg(2, pd, "failed probe\n");
2093                 return ret;
2094         }
2095
2096         ret = pkt_set_write_settings(pd);
2097         if (ret) {
2098                 pkt_dbg(1, pd, "failed saving write settings\n");
2099                 return -EIO;
2100         }
2101
2102         pkt_write_caching(pd, USE_WCACHING);
2103
2104         ret = pkt_get_max_speed(pd, &write_speed);
2105         if (ret)
2106                 write_speed = 16 * 177;
2107         switch (pd->mmc3_profile) {
2108                 case 0x13: /* DVD-RW */
2109                 case 0x1a: /* DVD+RW */
2110                 case 0x12: /* DVD-RAM */
2111                         pkt_dbg(1, pd, "write speed %ukB/s\n", write_speed);
2112                         break;
2113                 default:
2114                         ret = pkt_media_speed(pd, &media_write_speed);
2115                         if (ret)
2116                                 media_write_speed = 16;
2117                         write_speed = min(write_speed, media_write_speed * 177);
2118                         pkt_dbg(1, pd, "write speed %ux\n", write_speed / 176);
2119                         break;
2120         }
2121         read_speed = write_speed;
2122
2123         ret = pkt_set_speed(pd, write_speed, read_speed);
2124         if (ret) {
2125                 pkt_dbg(1, pd, "couldn't set write speed\n");
2126                 return -EIO;
2127         }
2128         pd->write_speed = write_speed;
2129         pd->read_speed = read_speed;
2130
2131         ret = pkt_perform_opc(pd);
2132         if (ret) {
2133                 pkt_dbg(1, pd, "Optimum Power Calibration failed\n");
2134         }
2135
2136         return 0;
2137 }
2138
2139 /*
2140  * called at open time.
2141  */
2142 static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2143 {
2144         int ret;
2145         long lba;
2146         struct request_queue *q;
2147         struct block_device *bdev;
2148
2149         /*
2150          * We need to re-open the cdrom device without O_NONBLOCK to be able
2151          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2152          * so open should not fail.
2153          */
2154         bdev = blkdev_get_by_dev(pd->bdev->bd_dev, FMODE_READ | FMODE_EXCL, pd);
2155         if (IS_ERR(bdev)) {
2156                 ret = PTR_ERR(bdev);
2157                 goto out;
2158         }
2159
2160         ret = pkt_get_last_written(pd, &lba);
2161         if (ret) {
2162                 pkt_err(pd, "pkt_get_last_written failed\n");
2163                 goto out_putdev;
2164         }
2165
2166         set_capacity(pd->disk, lba << 2);
2167         set_capacity_and_notify(pd->bdev->bd_disk, lba << 2);
2168
2169         q = bdev_get_queue(pd->bdev);
2170         if (write) {
2171                 ret = pkt_open_write(pd);
2172                 if (ret)
2173                         goto out_putdev;
2174                 /*
2175                  * Some CDRW drives can not handle writes larger than one packet,
2176                  * even if the size is a multiple of the packet size.
2177                  */
2178                 blk_queue_max_hw_sectors(q, pd->settings.size);
2179                 set_bit(PACKET_WRITABLE, &pd->flags);
2180         } else {
2181                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2182                 clear_bit(PACKET_WRITABLE, &pd->flags);
2183         }
2184
2185         ret = pkt_set_segment_merging(pd, q);
2186         if (ret)
2187                 goto out_putdev;
2188
2189         if (write) {
2190                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2191                         pkt_err(pd, "not enough memory for buffers\n");
2192                         ret = -ENOMEM;
2193                         goto out_putdev;
2194                 }
2195                 pkt_info(pd, "%lukB available on disc\n", lba << 1);
2196         }
2197
2198         return 0;
2199
2200 out_putdev:
2201         blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
2202 out:
2203         return ret;
2204 }
2205
2206 /*
2207  * called when the device is closed. makes sure that the device flushes
2208  * the internal cache before we close.
2209  */
2210 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2211 {
2212         if (flush && pkt_flush_cache(pd))
2213                 pkt_dbg(1, pd, "not flushing cache\n");
2214
2215         pkt_lock_door(pd, 0);
2216
2217         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2218         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2219
2220         pkt_shrink_pktlist(pd);
2221 }
2222
2223 static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2224 {
2225         if (dev_minor >= MAX_WRITERS)
2226                 return NULL;
2227
2228         dev_minor = array_index_nospec(dev_minor, MAX_WRITERS);
2229         return pkt_devs[dev_minor];
2230 }
2231
2232 static int pkt_open(struct block_device *bdev, fmode_t mode)
2233 {
2234         struct pktcdvd_device *pd = NULL;
2235         int ret;
2236
2237         mutex_lock(&pktcdvd_mutex);
2238         mutex_lock(&ctl_mutex);
2239         pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2240         if (!pd) {
2241                 ret = -ENODEV;
2242                 goto out;
2243         }
2244         BUG_ON(pd->refcnt < 0);
2245
2246         pd->refcnt++;
2247         if (pd->refcnt > 1) {
2248                 if ((mode & FMODE_WRITE) &&
2249                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2250                         ret = -EBUSY;
2251                         goto out_dec;
2252                 }
2253         } else {
2254                 ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2255                 if (ret)
2256                         goto out_dec;
2257                 /*
2258                  * needed here as well, since ext2 (among others) may change
2259                  * the blocksize at mount time
2260                  */
2261                 set_blocksize(bdev, CD_FRAMESIZE);
2262         }
2263
2264         mutex_unlock(&ctl_mutex);
2265         mutex_unlock(&pktcdvd_mutex);
2266         return 0;
2267
2268 out_dec:
2269         pd->refcnt--;
2270 out:
2271         mutex_unlock(&ctl_mutex);
2272         mutex_unlock(&pktcdvd_mutex);
2273         return ret;
2274 }
2275
2276 static void pkt_close(struct gendisk *disk, fmode_t mode)
2277 {
2278         struct pktcdvd_device *pd = disk->private_data;
2279
2280         mutex_lock(&pktcdvd_mutex);
2281         mutex_lock(&ctl_mutex);
2282         pd->refcnt--;
2283         BUG_ON(pd->refcnt < 0);
2284         if (pd->refcnt == 0) {
2285                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2286                 pkt_release_dev(pd, flush);
2287         }
2288         mutex_unlock(&ctl_mutex);
2289         mutex_unlock(&pktcdvd_mutex);
2290 }
2291
2292
2293 static void pkt_end_io_read_cloned(struct bio *bio)
2294 {
2295         struct packet_stacked_data *psd = bio->bi_private;
2296         struct pktcdvd_device *pd = psd->pd;
2297
2298         psd->bio->bi_status = bio->bi_status;
2299         bio_put(bio);
2300         bio_endio(psd->bio);
2301         mempool_free(psd, &psd_pool);
2302         pkt_bio_finished(pd);
2303 }
2304
2305 static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
2306 {
2307         struct bio *cloned_bio = bio_clone_fast(bio, GFP_NOIO, &pkt_bio_set);
2308         struct packet_stacked_data *psd = mempool_alloc(&psd_pool, GFP_NOIO);
2309
2310         psd->pd = pd;
2311         psd->bio = bio;
2312         bio_set_dev(cloned_bio, pd->bdev);
2313         cloned_bio->bi_private = psd;
2314         cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2315         pd->stats.secs_r += bio_sectors(bio);
2316         pkt_queue_bio(pd, cloned_bio);
2317 }
2318
2319 static void pkt_make_request_write(struct request_queue *q, struct bio *bio)
2320 {
2321         struct pktcdvd_device *pd = q->queuedata;
2322         sector_t zone;
2323         struct packet_data *pkt;
2324         int was_empty, blocked_bio;
2325         struct pkt_rb_node *node;
2326
2327         zone = get_zone(bio->bi_iter.bi_sector, pd);
2328
2329         /*
2330          * If we find a matching packet in state WAITING or READ_WAIT, we can
2331          * just append this bio to that packet.
2332          */
2333         spin_lock(&pd->cdrw.active_list_lock);
2334         blocked_bio = 0;
2335         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2336                 if (pkt->sector == zone) {
2337                         spin_lock(&pkt->lock);
2338                         if ((pkt->state == PACKET_WAITING_STATE) ||
2339                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2340                                 bio_list_add(&pkt->orig_bios, bio);
2341                                 pkt->write_size +=
2342                                         bio->bi_iter.bi_size / CD_FRAMESIZE;
2343                                 if ((pkt->write_size >= pkt->frames) &&
2344                                     (pkt->state == PACKET_WAITING_STATE)) {
2345                                         atomic_inc(&pkt->run_sm);
2346                                         wake_up(&pd->wqueue);
2347                                 }
2348                                 spin_unlock(&pkt->lock);
2349                                 spin_unlock(&pd->cdrw.active_list_lock);
2350                                 return;
2351                         } else {
2352                                 blocked_bio = 1;
2353                         }
2354                         spin_unlock(&pkt->lock);
2355                 }
2356         }
2357         spin_unlock(&pd->cdrw.active_list_lock);
2358
2359         /*
2360          * Test if there is enough room left in the bio work queue
2361          * (queue size >= congestion on mark).
2362          * If not, wait till the work queue size is below the congestion off mark.
2363          */
2364         spin_lock(&pd->lock);
2365         if (pd->write_congestion_on > 0
2366             && pd->bio_queue_size >= pd->write_congestion_on) {
2367                 set_bdi_congested(bio->bi_bdev->bd_disk->bdi, BLK_RW_ASYNC);
2368                 do {
2369                         spin_unlock(&pd->lock);
2370                         congestion_wait(BLK_RW_ASYNC, HZ);
2371                         spin_lock(&pd->lock);
2372                 } while(pd->bio_queue_size > pd->write_congestion_off);
2373         }
2374         spin_unlock(&pd->lock);
2375
2376         /*
2377          * No matching packet found. Store the bio in the work queue.
2378          */
2379         node = mempool_alloc(&pd->rb_pool, GFP_NOIO);
2380         node->bio = bio;
2381         spin_lock(&pd->lock);
2382         BUG_ON(pd->bio_queue_size < 0);
2383         was_empty = (pd->bio_queue_size == 0);
2384         pkt_rbtree_insert(pd, node);
2385         spin_unlock(&pd->lock);
2386
2387         /*
2388          * Wake up the worker thread.
2389          */
2390         atomic_set(&pd->scan_queue, 1);
2391         if (was_empty) {
2392                 /* This wake_up is required for correct operation */
2393                 wake_up(&pd->wqueue);
2394         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2395                 /*
2396                  * This wake up is not required for correct operation,
2397                  * but improves performance in some cases.
2398                  */
2399                 wake_up(&pd->wqueue);
2400         }
2401 }
2402
2403 static blk_qc_t pkt_submit_bio(struct bio *bio)
2404 {
2405         struct pktcdvd_device *pd;
2406         char b[BDEVNAME_SIZE];
2407         struct bio *split;
2408
2409         blk_queue_split(&bio);
2410
2411         pd = bio->bi_bdev->bd_disk->queue->queuedata;
2412         if (!pd) {
2413                 pr_err("%s incorrect request queue\n", bio_devname(bio, b));
2414                 goto end_io;
2415         }
2416
2417         pkt_dbg(2, pd, "start = %6llx stop = %6llx\n",
2418                 (unsigned long long)bio->bi_iter.bi_sector,
2419                 (unsigned long long)bio_end_sector(bio));
2420
2421         /*
2422          * Clone READ bios so we can have our own bi_end_io callback.
2423          */
2424         if (bio_data_dir(bio) == READ) {
2425                 pkt_make_request_read(pd, bio);
2426                 return BLK_QC_T_NONE;
2427         }
2428
2429         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2430                 pkt_notice(pd, "WRITE for ro device (%llu)\n",
2431                            (unsigned long long)bio->bi_iter.bi_sector);
2432                 goto end_io;
2433         }
2434
2435         if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2436                 pkt_err(pd, "wrong bio size\n");
2437                 goto end_io;
2438         }
2439
2440         do {
2441                 sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
2442                 sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2443
2444                 if (last_zone != zone) {
2445                         BUG_ON(last_zone != zone + pd->settings.size);
2446
2447                         split = bio_split(bio, last_zone -
2448                                           bio->bi_iter.bi_sector,
2449                                           GFP_NOIO, &pkt_bio_set);
2450                         bio_chain(split, bio);
2451                 } else {
2452                         split = bio;
2453                 }
2454
2455                 pkt_make_request_write(bio->bi_bdev->bd_disk->queue, split);
2456         } while (split != bio);
2457
2458         return BLK_QC_T_NONE;
2459 end_io:
2460         bio_io_error(bio);
2461         return BLK_QC_T_NONE;
2462 }
2463
2464 static void pkt_init_queue(struct pktcdvd_device *pd)
2465 {
2466         struct request_queue *q = pd->disk->queue;
2467
2468         blk_queue_logical_block_size(q, CD_FRAMESIZE);
2469         blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2470         q->queuedata = pd;
2471 }
2472
2473 static int pkt_seq_show(struct seq_file *m, void *p)
2474 {
2475         struct pktcdvd_device *pd = m->private;
2476         char *msg;
2477         char bdev_buf[BDEVNAME_SIZE];
2478         int states[PACKET_NUM_STATES];
2479
2480         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2481                    bdevname(pd->bdev, bdev_buf));
2482
2483         seq_printf(m, "\nSettings:\n");
2484         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2485
2486         if (pd->settings.write_type == 0)
2487                 msg = "Packet";
2488         else
2489                 msg = "Unknown";
2490         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2491
2492         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2493         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2494
2495         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2496
2497         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2498                 msg = "Mode 1";
2499         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2500                 msg = "Mode 2";
2501         else
2502                 msg = "Unknown";
2503         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2504
2505         seq_printf(m, "\nStatistics:\n");
2506         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2507         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2508         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2509         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2510         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2511
2512         seq_printf(m, "\nMisc:\n");
2513         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2514         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2515         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2516         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2517         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2518         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2519
2520         seq_printf(m, "\nQueue state:\n");
2521         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2522         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2523         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2524
2525         pkt_count_states(pd, states);
2526         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2527                    states[0], states[1], states[2], states[3], states[4], states[5]);
2528
2529         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2530                         pd->write_congestion_off,
2531                         pd->write_congestion_on);
2532         return 0;
2533 }
2534
2535 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2536 {
2537         int i;
2538         char b[BDEVNAME_SIZE];
2539         struct block_device *bdev;
2540
2541         if (pd->pkt_dev == dev) {
2542                 pkt_err(pd, "recursive setup not allowed\n");
2543                 return -EBUSY;
2544         }
2545         for (i = 0; i < MAX_WRITERS; i++) {
2546                 struct pktcdvd_device *pd2 = pkt_devs[i];
2547                 if (!pd2)
2548                         continue;
2549                 if (pd2->bdev->bd_dev == dev) {
2550                         pkt_err(pd, "%s already setup\n",
2551                                 bdevname(pd2->bdev, b));
2552                         return -EBUSY;
2553                 }
2554                 if (pd2->pkt_dev == dev) {
2555                         pkt_err(pd, "can't chain pktcdvd devices\n");
2556                         return -EBUSY;
2557                 }
2558         }
2559
2560         bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_NDELAY, NULL);
2561         if (IS_ERR(bdev))
2562                 return PTR_ERR(bdev);
2563         if (!blk_queue_scsi_passthrough(bdev_get_queue(bdev))) {
2564                 blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2565                 return -EINVAL;
2566         }
2567
2568         /* This is safe, since we have a reference from open(). */
2569         __module_get(THIS_MODULE);
2570
2571         pd->bdev = bdev;
2572         set_blocksize(bdev, CD_FRAMESIZE);
2573
2574         pkt_init_queue(pd);
2575
2576         atomic_set(&pd->cdrw.pending_bios, 0);
2577         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2578         if (IS_ERR(pd->cdrw.thread)) {
2579                 pkt_err(pd, "can't start kernel thread\n");
2580                 goto out_mem;
2581         }
2582
2583         proc_create_single_data(pd->name, 0, pkt_proc, pkt_seq_show, pd);
2584         pkt_dbg(1, pd, "writer mapped to %s\n", bdevname(bdev, b));
2585         return 0;
2586
2587 out_mem:
2588         blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2589         /* This is safe: open() is still holding a reference. */
2590         module_put(THIS_MODULE);
2591         return -ENOMEM;
2592 }
2593
2594 static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2595 {
2596         struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2597         int ret;
2598
2599         pkt_dbg(2, pd, "cmd %x, dev %d:%d\n",
2600                 cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2601
2602         mutex_lock(&pktcdvd_mutex);
2603         switch (cmd) {
2604         case CDROMEJECT:
2605                 /*
2606                  * The door gets locked when the device is opened, so we
2607                  * have to unlock it or else the eject command fails.
2608                  */
2609                 if (pd->refcnt == 1)
2610                         pkt_lock_door(pd, 0);
2611                 fallthrough;
2612         /*
2613          * forward selected CDROM ioctls to CD-ROM, for UDF
2614          */
2615         case CDROMMULTISESSION:
2616         case CDROMREADTOCENTRY:
2617         case CDROM_LAST_WRITTEN:
2618         case CDROM_SEND_PACKET:
2619         case SCSI_IOCTL_SEND_COMMAND:
2620                 if (!bdev->bd_disk->fops->ioctl)
2621                         ret = -ENOTTY;
2622                 else
2623                         ret = bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
2624                 break;
2625         default:
2626                 pkt_dbg(2, pd, "Unknown ioctl (%x)\n", cmd);
2627                 ret = -ENOTTY;
2628         }
2629         mutex_unlock(&pktcdvd_mutex);
2630
2631         return ret;
2632 }
2633
2634 static unsigned int pkt_check_events(struct gendisk *disk,
2635                                      unsigned int clearing)
2636 {
2637         struct pktcdvd_device *pd = disk->private_data;
2638         struct gendisk *attached_disk;
2639
2640         if (!pd)
2641                 return 0;
2642         if (!pd->bdev)
2643                 return 0;
2644         attached_disk = pd->bdev->bd_disk;
2645         if (!attached_disk || !attached_disk->fops->check_events)
2646                 return 0;
2647         return attached_disk->fops->check_events(attached_disk, clearing);
2648 }
2649
2650 static char *pkt_devnode(struct gendisk *disk, umode_t *mode)
2651 {
2652         return kasprintf(GFP_KERNEL, "pktcdvd/%s", disk->disk_name);
2653 }
2654
2655 static const struct block_device_operations pktcdvd_ops = {
2656         .owner =                THIS_MODULE,
2657         .submit_bio =           pkt_submit_bio,
2658         .open =                 pkt_open,
2659         .release =              pkt_close,
2660         .ioctl =                pkt_ioctl,
2661         .compat_ioctl =         blkdev_compat_ptr_ioctl,
2662         .check_events =         pkt_check_events,
2663         .devnode =              pkt_devnode,
2664 };
2665
2666 /*
2667  * Set up mapping from pktcdvd device to CD-ROM device.
2668  */
2669 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2670 {
2671         int idx;
2672         int ret = -ENOMEM;
2673         struct pktcdvd_device *pd;
2674         struct gendisk *disk;
2675
2676         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2677
2678         for (idx = 0; idx < MAX_WRITERS; idx++)
2679                 if (!pkt_devs[idx])
2680                         break;
2681         if (idx == MAX_WRITERS) {
2682                 pr_err("max %d writers supported\n", MAX_WRITERS);
2683                 ret = -EBUSY;
2684                 goto out_mutex;
2685         }
2686
2687         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2688         if (!pd)
2689                 goto out_mutex;
2690
2691         ret = mempool_init_kmalloc_pool(&pd->rb_pool, PKT_RB_POOL_SIZE,
2692                                         sizeof(struct pkt_rb_node));
2693         if (ret)
2694                 goto out_mem;
2695
2696         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2697         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2698         spin_lock_init(&pd->cdrw.active_list_lock);
2699
2700         spin_lock_init(&pd->lock);
2701         spin_lock_init(&pd->iosched.lock);
2702         bio_list_init(&pd->iosched.read_queue);
2703         bio_list_init(&pd->iosched.write_queue);
2704         sprintf(pd->name, DRIVER_NAME"%d", idx);
2705         init_waitqueue_head(&pd->wqueue);
2706         pd->bio_queue = RB_ROOT;
2707
2708         pd->write_congestion_on  = write_congestion_on;
2709         pd->write_congestion_off = write_congestion_off;
2710
2711         ret = -ENOMEM;
2712         disk = blk_alloc_disk(NUMA_NO_NODE);
2713         if (!disk)
2714                 goto out_mem;
2715         pd->disk = disk;
2716         disk->major = pktdev_major;
2717         disk->first_minor = idx;
2718         disk->minors = 1;
2719         disk->fops = &pktcdvd_ops;
2720         disk->flags = GENHD_FL_REMOVABLE;
2721         strcpy(disk->disk_name, pd->name);
2722         disk->private_data = pd;
2723
2724         pd->pkt_dev = MKDEV(pktdev_major, idx);
2725         ret = pkt_new_dev(pd, dev);
2726         if (ret)
2727                 goto out_mem2;
2728
2729         /* inherit events of the host device */
2730         disk->events = pd->bdev->bd_disk->events;
2731
2732         add_disk(disk);
2733
2734         pkt_sysfs_dev_new(pd);
2735         pkt_debugfs_dev_new(pd);
2736
2737         pkt_devs[idx] = pd;
2738         if (pkt_dev)
2739                 *pkt_dev = pd->pkt_dev;
2740
2741         mutex_unlock(&ctl_mutex);
2742         return 0;
2743
2744 out_mem2:
2745         blk_cleanup_disk(disk);
2746 out_mem:
2747         mempool_exit(&pd->rb_pool);
2748         kfree(pd);
2749 out_mutex:
2750         mutex_unlock(&ctl_mutex);
2751         pr_err("setup of pktcdvd device failed\n");
2752         return ret;
2753 }
2754
2755 /*
2756  * Tear down mapping from pktcdvd device to CD-ROM device.
2757  */
2758 static int pkt_remove_dev(dev_t pkt_dev)
2759 {
2760         struct pktcdvd_device *pd;
2761         int idx;
2762         int ret = 0;
2763
2764         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2765
2766         for (idx = 0; idx < MAX_WRITERS; idx++) {
2767                 pd = pkt_devs[idx];
2768                 if (pd && (pd->pkt_dev == pkt_dev))
2769                         break;
2770         }
2771         if (idx == MAX_WRITERS) {
2772                 pr_debug("dev not setup\n");
2773                 ret = -ENXIO;
2774                 goto out;
2775         }
2776
2777         if (pd->refcnt > 0) {
2778                 ret = -EBUSY;
2779                 goto out;
2780         }
2781         if (!IS_ERR(pd->cdrw.thread))
2782                 kthread_stop(pd->cdrw.thread);
2783
2784         pkt_devs[idx] = NULL;
2785
2786         pkt_debugfs_dev_remove(pd);
2787         pkt_sysfs_dev_remove(pd);
2788
2789         blkdev_put(pd->bdev, FMODE_READ | FMODE_NDELAY);
2790
2791         remove_proc_entry(pd->name, pkt_proc);
2792         pkt_dbg(1, pd, "writer unmapped\n");
2793
2794         del_gendisk(pd->disk);
2795         blk_cleanup_disk(pd->disk);
2796
2797         mempool_exit(&pd->rb_pool);
2798         kfree(pd);
2799
2800         /* This is safe: open() is still holding a reference. */
2801         module_put(THIS_MODULE);
2802
2803 out:
2804         mutex_unlock(&ctl_mutex);
2805         return ret;
2806 }
2807
2808 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2809 {
2810         struct pktcdvd_device *pd;
2811
2812         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2813
2814         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2815         if (pd) {
2816                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2817                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2818         } else {
2819                 ctrl_cmd->dev = 0;
2820                 ctrl_cmd->pkt_dev = 0;
2821         }
2822         ctrl_cmd->num_devices = MAX_WRITERS;
2823
2824         mutex_unlock(&ctl_mutex);
2825 }
2826
2827 static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2828 {
2829         void __user *argp = (void __user *)arg;
2830         struct pkt_ctrl_command ctrl_cmd;
2831         int ret = 0;
2832         dev_t pkt_dev = 0;
2833
2834         if (cmd != PACKET_CTRL_CMD)
2835                 return -ENOTTY;
2836
2837         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2838                 return -EFAULT;
2839
2840         switch (ctrl_cmd.command) {
2841         case PKT_CTRL_CMD_SETUP:
2842                 if (!capable(CAP_SYS_ADMIN))
2843                         return -EPERM;
2844                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2845                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2846                 break;
2847         case PKT_CTRL_CMD_TEARDOWN:
2848                 if (!capable(CAP_SYS_ADMIN))
2849                         return -EPERM;
2850                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2851                 break;
2852         case PKT_CTRL_CMD_STATUS:
2853                 pkt_get_status(&ctrl_cmd);
2854                 break;
2855         default:
2856                 return -ENOTTY;
2857         }
2858
2859         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2860                 return -EFAULT;
2861         return ret;
2862 }
2863
2864 #ifdef CONFIG_COMPAT
2865 static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2866 {
2867         return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2868 }
2869 #endif
2870
2871 static const struct file_operations pkt_ctl_fops = {
2872         .open           = nonseekable_open,
2873         .unlocked_ioctl = pkt_ctl_ioctl,
2874 #ifdef CONFIG_COMPAT
2875         .compat_ioctl   = pkt_ctl_compat_ioctl,
2876 #endif
2877         .owner          = THIS_MODULE,
2878         .llseek         = no_llseek,
2879 };
2880
2881 static struct miscdevice pkt_misc = {
2882         .minor          = MISC_DYNAMIC_MINOR,
2883         .name           = DRIVER_NAME,
2884         .nodename       = "pktcdvd/control",
2885         .fops           = &pkt_ctl_fops
2886 };
2887
2888 static int __init pkt_init(void)
2889 {
2890         int ret;
2891
2892         mutex_init(&ctl_mutex);
2893
2894         ret = mempool_init_kmalloc_pool(&psd_pool, PSD_POOL_SIZE,
2895                                     sizeof(struct packet_stacked_data));
2896         if (ret)
2897                 return ret;
2898         ret = bioset_init(&pkt_bio_set, BIO_POOL_SIZE, 0, 0);
2899         if (ret) {
2900                 mempool_exit(&psd_pool);
2901                 return ret;
2902         }
2903
2904         ret = register_blkdev(pktdev_major, DRIVER_NAME);
2905         if (ret < 0) {
2906                 pr_err("unable to register block device\n");
2907                 goto out2;
2908         }
2909         if (!pktdev_major)
2910                 pktdev_major = ret;
2911
2912         ret = pkt_sysfs_init();
2913         if (ret)
2914                 goto out;
2915
2916         pkt_debugfs_init();
2917
2918         ret = misc_register(&pkt_misc);
2919         if (ret) {
2920                 pr_err("unable to register misc device\n");
2921                 goto out_misc;
2922         }
2923
2924         pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
2925
2926         return 0;
2927
2928 out_misc:
2929         pkt_debugfs_cleanup();
2930         pkt_sysfs_cleanup();
2931 out:
2932         unregister_blkdev(pktdev_major, DRIVER_NAME);
2933 out2:
2934         mempool_exit(&psd_pool);
2935         bioset_exit(&pkt_bio_set);
2936         return ret;
2937 }
2938
2939 static void __exit pkt_exit(void)
2940 {
2941         remove_proc_entry("driver/"DRIVER_NAME, NULL);
2942         misc_deregister(&pkt_misc);
2943
2944         pkt_debugfs_cleanup();
2945         pkt_sysfs_cleanup();
2946
2947         unregister_blkdev(pktdev_major, DRIVER_NAME);
2948         mempool_exit(&psd_pool);
2949         bioset_exit(&pkt_bio_set);
2950 }
2951
2952 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
2953 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
2954 MODULE_LICENSE("GPL");
2955
2956 module_init(pkt_init);
2957 module_exit(pkt_exit);